Sample records for preanalytical sample quality
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Preanalytical quality in clinical chemistry laboratory.
Ahmad, M Imteyaz; Ramesh, K L; Kumar, Ravi
2014-01-01
Haemolysis is usually caused by inadequate specimen collection or preanalytical handling and is suggested to be a suitable indicator of preanalytical quality. We investigated the prevalence of detectable haemolysis in all routine venous blood samples in OPDs and IPDs to identify differences in preanalytical quality. Haemolysis index (HI) values were obtained from a Vitros 5,1 in the routine clinical chemistry laboratory for samples collected in the outpatient department (OPD) collection centres, a hospital, and inpatient departments (IPD). Haemolysis was defined as a HI > or = 15 (detection limit). Samples from the OPD with the highest prevalence of haemolysis were 6.1 times (95% confidence interval (CI) 4.0 - 9.2) more often haemolysed compared to the center with the lowest prevalence. Of the samples collected in primary health care, 10.4% were haemolysed compared to 31.1% in the IPDs (p = 0.001). A notable difference in haemolysed samples was found between the IPDs section staffed by emergency medicine physicians and the section staffed by primary health care physicians (34.8% vs. 11.3%, p = 0.001). The significant variation in haemolysis indices among the investigated units is likely to reflect varying preanalytical conditions. The HI is a valuable tool for estimation and follow-up of preanalytical quality in the health care laboratory.
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Evaluation of Preanalytical Quality Indicators by Six Sigma and Pareto`s Principle.
Kulkarni, Sweta; Ramesh, R; Srinivasan, A R; Silvia, C R Wilma Delphine
2018-01-01
Preanalytical steps are the major sources of error in clinical laboratory. The analytical errors can be corrected by quality control procedures but there is a need for stringent quality checks in preanalytical area as these processes are done outside the laboratory. Sigma value depicts the performance of laboratory and its quality measures. Hence in the present study six sigma and Pareto principle was applied to preanalytical quality indicators to evaluate the clinical biochemistry laboratory performance. This observational study was carried out for a period of 1 year from November 2015-2016. A total of 1,44,208 samples and 54,265 test requisition forms were screened for preanalytical errors like missing patient information, sample collection details in forms and hemolysed, lipemic, inappropriate, insufficient samples and total number of errors were calculated and converted into defects per million and sigma scale. Pareto`s chart was drawn using total number of errors and cumulative percentage. In 75% test requisition forms diagnosis was not mentioned and sigma value of 0.9 was obtained and for other errors like sample receiving time, stat and type of sample sigma values were 2.9, 2.6, and 2.8 respectively. For insufficient sample and improper ratio of blood to anticoagulant sigma value was 4.3. Pareto`s chart depicts out of 80% of errors in requisition forms, 20% is contributed by missing information like diagnosis. The development of quality indicators, application of six sigma and Pareto`s principle are quality measures by which not only preanalytical, the total testing process can be improved.
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2017-01-01
Background Laboratory testing is roughly divided into three phases: a pre-analytical phase, an analytical phase and a post-analytical phase. Most analytical errors have been attributed to the analytical phase. However, recent studies have shown that up to 70% of analytical errors reflect the pre-analytical phase. The pre-analytical phase comprises all processes from the time a laboratory request is made by a physician until the specimen is analyzed at the lab. Generally, the pre-analytical phase includes patient preparation, specimen transportation, specimen collection and storage. In the present study, we report the first comprehensive assessment of the frequency and types of pre-analytical errors at the Sulaimani diagnostic labs in Iraqi Kurdistan. Materials and Methods Over 2 months, 5500 venous blood samples were observed in 10 public diagnostic labs of Sulaimani City. The percentages of rejected samples and types of sample inappropriateness were evaluated. The percentage of each of the following pre-analytical errors were recorded: delay in sample transportation, clotted samples, expired reagents, hemolyzed samples, samples not on ice, incorrect sample identification, insufficient sample, tube broken in centrifuge, request procedure errors, sample mix-ups, communication conflicts, misinterpreted orders, lipemic samples, contaminated samples and missed physician’s request orders. The difference between the relative frequencies of errors observed in the hospitals considered was tested using a proportional Z test. In particular, the survey aimed to discover whether analytical errors were recorded and examine the types of platforms used in the selected diagnostic labs. Results The analysis showed a high prevalence of improper sample handling during the pre-analytical phase. In appropriate samples, the percentage error was as high as 39%. The major reasons for rejection were hemolyzed samples (9%), incorrect sample identification (8%) and clotted samples (6%). Most quality control schemes at Sulaimani hospitals focus only on the analytical phase, and none of the pre-analytical errors were recorded. Interestingly, none of the labs were internationally accredited; therefore, corrective actions are needed at these hospitals to ensure better health outcomes. Internal and External Quality Assessment Schemes (EQAS) for the pre-analytical phase at Sulaimani clinical laboratories should be implemented at public hospitals. Furthermore, lab personnel, particularly phlebotomists, need continuous training on the importance of sample quality to obtain accurate test results. PMID:28107395
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Najat, Dereen
2017-01-01
Laboratory testing is roughly divided into three phases: a pre-analytical phase, an analytical phase and a post-analytical phase. Most analytical errors have been attributed to the analytical phase. However, recent studies have shown that up to 70% of analytical errors reflect the pre-analytical phase. The pre-analytical phase comprises all processes from the time a laboratory request is made by a physician until the specimen is analyzed at the lab. Generally, the pre-analytical phase includes patient preparation, specimen transportation, specimen collection and storage. In the present study, we report the first comprehensive assessment of the frequency and types of pre-analytical errors at the Sulaimani diagnostic labs in Iraqi Kurdistan. Over 2 months, 5500 venous blood samples were observed in 10 public diagnostic labs of Sulaimani City. The percentages of rejected samples and types of sample inappropriateness were evaluated. The percentage of each of the following pre-analytical errors were recorded: delay in sample transportation, clotted samples, expired reagents, hemolyzed samples, samples not on ice, incorrect sample identification, insufficient sample, tube broken in centrifuge, request procedure errors, sample mix-ups, communication conflicts, misinterpreted orders, lipemic samples, contaminated samples and missed physician's request orders. The difference between the relative frequencies of errors observed in the hospitals considered was tested using a proportional Z test. In particular, the survey aimed to discover whether analytical errors were recorded and examine the types of platforms used in the selected diagnostic labs. The analysis showed a high prevalence of improper sample handling during the pre-analytical phase. In appropriate samples, the percentage error was as high as 39%. The major reasons for rejection were hemolyzed samples (9%), incorrect sample identification (8%) and clotted samples (6%). Most quality control schemes at Sulaimani hospitals focus only on the analytical phase, and none of the pre-analytical errors were recorded. Interestingly, none of the labs were internationally accredited; therefore, corrective actions are needed at these hospitals to ensure better health outcomes. Internal and External Quality Assessment Schemes (EQAS) for the pre-analytical phase at Sulaimani clinical laboratories should be implemented at public hospitals. Furthermore, lab personnel, particularly phlebotomists, need continuous training on the importance of sample quality to obtain accurate test results.
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Blood venous sample collection: Recommendations overview and a checklist to improve quality.
Giavarina, Davide; Lippi, Giuseppe
2017-07-01
The extra-analytical phases of the total testing process have substantial impact on managed care, as well as an inherent high risk of vulnerability to errors which is often greater than that of the analytical phase. The collection of biological samples is a crucial preanalytical activity. Problems or errors occurring shortly before, or soon after, this preanalytical step may impair sample quality and characteristics, or else modify the final results of testing. The standardization of fasting requirements, rest, patient position and psychological state of the patient are therefore crucial for mitigating the impact of preanalytical variability. Moreover, the quality of materials used for collecting specimens, along with their compatibility, can guarantee sample quality and persistence of chemical and physical characteristics of the analytes over time, so safeguarding the reliability of testing. Appropriate techniques and sampling procedures are effective to prevent problems such as hemolysis, undue clotting in the blood tube, draw of insufficient sample volume and modification of analyte concentration. An accurate identification of both patient and blood samples is a key priority as for other healthcare activities. Good laboratory practice and appropriate training of operators, by specifically targeting collection of biological samples, blood in particular, may greatly improve this issue, thus lowering the risk of errors and their adverse clinical consequences. The implementation of a simple and rapid check-list, including verification of blood collection devices, patient preparation and sampling techniques, was found to be effective for enhancing sample quality and reducing some preanalytical errors associated with these procedures. The use of this tool, along with implementation of objective and standardized systems for detecting non-conformities related to unsuitable samples, can be helpful for standardizing preanalytical activities and improving the quality of laboratory diagnostics, ultimately helping to reaffirm a "preanalytical" culture founded on knowledge and real risk perception. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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Rao, Shalinee; Masilamani, Suresh; Sundaram, Sandhya; Duvuru, Prathiba; Swaminathan, Rajendiran
2016-01-01
Quality monitoring in histopathology unit is categorized into three phases, pre-analytical, analytical and post-analytical, to cover various steps in the entire test cycle. Review of literature on quality evaluation studies pertaining to histopathology revealed that earlier reports were mainly focused on analytical aspects with limited studies on assessment of pre-analytical phase. Pre-analytical phase encompasses several processing steps and handling of specimen/sample by multiple individuals, thus allowing enough scope for errors. Due to its critical nature and limited studies in the past to assess quality in pre-analytical phase, it deserves more attention. This study was undertaken to analyse and assess the quality parameters in pre-analytical phase in a histopathology laboratory. This was a retrospective study done on pre-analytical parameters in histopathology laboratory of a tertiary care centre on 18,626 tissue specimens received in 34 months. Registers and records were checked for efficiency and errors for pre-analytical quality variables: specimen identification, specimen in appropriate fixatives, lost specimens, daily internal quality control performance on staining, performance in inter-laboratory quality assessment program {External quality assurance program (EQAS)} and evaluation of internal non-conformities (NC) for other errors. The study revealed incorrect specimen labelling in 0.04%, 0.01% and 0.01% in 2007, 2008 and 2009 respectively. About 0.04%, 0.07% and 0.18% specimens were not sent in fixatives in 2007, 2008 and 2009 respectively. There was no incidence of specimen lost. A total of 113 non-conformities were identified out of which 92.9% belonged to the pre-analytical phase. The predominant NC (any deviation from normal standard which may generate an error and result in compromising with quality standards) identified was wrong labelling of slides. Performance in EQAS for pre-analytical phase was satisfactory in 6 of 9 cycles. A low incidence of errors in pre-analytical phase implies that a satisfactory level of quality standards was being practiced with still scope for improvement.
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Arul, Pitchaikaran; Pushparaj, Magesh; Pandian, Kanmani; Chennimalai, Lingasamy; Rajendran, Karthika; Selvaraj, Eniya; Masilamani, Suresh
2018-01-01
An important component of laboratory medicine is preanalytical phase. Since laboratory report plays a major role in patient management, more importance should be given to the quality of laboratory tests. The present study was undertaken to find the prevalence and types of preanalytical errors at a tertiary care hospital in South India. In this cross-sectional study, a total of 118,732 samples ([62,474 outpatient department [OPD] and 56,258 inpatient department [IPD]) were received in hematology laboratory. These samples were analyzed for preanalytical errors such as misidentification, incorrect vials, inadequate samples, clotted samples, diluted samples, and hemolyzed samples. The overall prevalence of preanalytical errors found was 513 samples, which is 0.43% of the total number of samples received. The most common preanalytical error observed was inadequate samples followed by clotted samples. Overall frequencies (both OPD and IPD) of preanalytical errors such as misidentification, incorrect vials, inadequate samples, clotted samples, diluted samples, and hemolyzed samples were 0.02%, 0.05%, 0.2%, 0.12%, 0.02%, and 0.03%, respectively. The present study concluded that incorrect phlebotomy techniques due to lack of awareness is the main reason for preanalytical errors. This can be avoided by proper communication and coordination between laboratory and wards, proper training and continuing medical education programs for laboratory and paramedical staffs, and knowledge of the intervening factors that can influence laboratory results.
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Pre-analytical issues in the haemostasis laboratory: guidance for the clinical laboratories.
Magnette, A; Chatelain, M; Chatelain, B; Ten Cate, H; Mullier, F
2016-01-01
Ensuring quality has become a daily requirement in laboratories. In haemostasis, even more than in other disciplines of biology, quality is determined by a pre-analytical step that encompasses all procedures, starting with the formulation of the medical question, and includes patient preparation, sample collection, handling, transportation, processing, and storage until time of analysis. This step, based on a variety of manual activities, is the most vulnerable part of the total testing process and is a major component of the reliability and validity of results in haemostasis and constitutes the most important source of erroneous or un-interpretable results. Pre-analytical errors may occur throughout the testing process and arise from unsuitable, inappropriate or wrongly handled procedures. Problems may arise during the collection of blood specimens such as misidentification of the sample, use of inadequate devices or needles, incorrect order of draw, prolonged tourniquet placing, unsuccessful attempts to locate the vein, incorrect use of additive tubes, collection of unsuitable samples for quality or quantity, inappropriate mixing of a sample, etc. Some factors can alter the result of a sample constituent after collection during transportation, preparation and storage. Laboratory errors can often have serious adverse consequences. Lack of standardized procedures for sample collection accounts for most of the errors encountered within the total testing process. They can also have clinical consequences as well as a significant impact on patient care, especially those related to specialized tests as these are often considered as "diagnostic". Controlling pre-analytical variables is critical since this has a direct influence on the quality of results and on their clinical reliability. The accurate standardization of the pre-analytical phase is of pivotal importance for achieving reliable results of coagulation tests and should reduce the side effects of the influence factors. This review is a summary of the most important recommendations regarding the importance of pre-analytical factors for coagulation testing and should be a tool to increase awareness about the importance of pre-analytical factors for coagulation testing.
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Preanalytical Errors in Hematology Laboratory- an Avoidable Incompetence.
HarsimranKaur, Vikram Narang; Selhi, Pavneet Kaur; Sood, Neena; Singh, Aminder
2016-01-01
Quality assurance in the hematology laboratory is a must to ensure laboratory users of reliable test results with high degree of precision and accuracy. Even after so many advances in hematology laboratory practice, pre-analytical errors remain a challenge for practicing pathologists. This study was undertaken with an objective to evaluate the types and frequency of preanalytical errors in hematology laboratory of our center. All the samples received in the Hematology Laboratory of Dayanand Medical College and Hospital, Ludhiana, India over a period of one year (July 2013-July 2014) were included in the study and preanalytical variables like clotted samples, quantity not sufficient, wrong sample, without label, wrong label were studied. Of 471,006 samples received in the laboratory, preanalytical errors, as per the above mentioned categories was found in 1802 samples. The most common error was clotted samples (1332 samples, 0.28% of the total samples) followed by quantity not sufficient (328 sample, 0.06%), wrong sample (96 samples, 0.02%), without label (24 samples, 0.005%) and wrong label (22 samples, 0.005%). Preanalytical errors are frequent in laboratories and can be corrected by regular analysis of the variables involved. Rectification can be done by regular education of the staff.
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Monitoring and reporting of preanalytical errors in laboratory medicine: the UK situation.
Cornes, Michael P; Atherton, Jennifer; Pourmahram, Ghazaleh; Borthwick, Hazel; Kyle, Betty; West, Jamie; Costelloe, Seán J
2016-03-01
Most errors in the clinical laboratory occur in the preanalytical phase. This study aimed to comprehensively describe the prevalence and nature of preanalytical quality monitoring practices in UK clinical laboratories. A survey was sent on behalf of the Association for Clinical Biochemistry and Laboratory Medicine Preanalytical Working Group (ACB-WG-PA) to all heads of department of clinical laboratories in the UK. The survey captured data on the analytical platform and Laboratory Information Management System in use; which preanalytical errors were recorded and how they were classified and gauged interest in an external quality assurance scheme for preanalytical errors. Of the 157 laboratories asked to participate, responses were received from 104 (66.2%). Laboratory error rates were recorded per number of specimens, rather than per number of requests in 51% of respondents. Aside from serum indices for haemolysis, icterus and lipaemia, which were measured in 80% of laboratories, the most common errors recorded were booking-in errors (70.1%) and sample mislabelling (56.9%) in laboratories who record preanalytical errors. Of the laboratories surveyed, 95.9% expressed an interest in guidance on recording preanalytical error and 91.8% expressed interest in an external quality assurance scheme. This survey observes a wide variation in the definition, repertoire and collection methods for preanalytical errors in the UK. Data indicate there is a lot of interest in improving preanalytical data collection. The ACB-WG-PA aims to produce guidance and support for laboratories to standardize preanalytical data collection and to help establish and validate an external quality assurance scheme for interlaboratory comparison. © The Author(s) 2015.
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Sølvik, Una Ørvim; Bjelkarøy, Wenche Iren; Berg, Kari van den; Saga, Anne Lise; Hager, Helle Borgstrøm; Sandberg, Sverre
2017-10-26
Errors in the preanalytical phase in clinical laboratories affect patient safety. The aim of this study was to evaluate the effect of intensive educational efforts together with external quality assessment (EQA) of the preanalytical phase from 2013 to 2015 to improve patient identification in primary health care in Norway. In addition, routines for venous and capillary blood sampling were investigated. A preanalytical EQA was circulated in 2013 by the Norwegian Quality Improvement of Laboratory Examinations (Noklus) to general practitioner offices and nursing homes (n=2000) to obtain information about important issues to focus on before launching an intensive educational program with courses, posters and visits in 2013-2015. Preanalytical EQA surveys were further circulated in 2014 and 2015. The response rate varied between 42% and 55%. The percentages of participants asking for the patients' name and the Norwegian identification number increased from about 8% in 2013 to about 35% in 2015. The increase was similar for those participating in only one EQA survey and for those who participated in EQA surveys both in 2013 and 2015. Guidelines for venous and capillary blood sampling were not always followed. Educational efforts more than the preanalytical EQA influenced the actions and resulted in an increase in the percentages of participants that followed the guidelines for patient identification. Some aspects of blood sampling routines need improvement.
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Vacata, Vladimir; Jahns-Streubel, Gerlinde; Baldus, Mirjana; Wood, William Graham
2007-01-01
This report was written in response to the article by Wood published recently in this journal. It describes a practical solution to the problems of controlling the pre-analytical phase in the clinical diagnostic laboratory. As an indicator of quality in the pre-analytical phase of sample processing, a target analyte was chosen which is sensitive to delay in centrifugation and/or analysis. The results of analyses of the samples sent by satellite medical practitioners were compared with those from an on-site hospital laboratory with a controllable optimized pre-analytical phase. The aim of the comparison was: (a) to identify those medical practices whose mean/median sample values significantly deviate from those of the control situation in the hospital laboratory due to the possible problems in the pre-analytical phase; (b) to aid these laboratories in the process of rectifying these problems. A Microsoft Excel-based Pre-Analytical Survey tool (PAS tool) has been developed which addresses the above mentioned problems. It has been tested on serum potassium which is known to be sensitive to delay and/or irregularities in sample treatment. The PAS tool has been shown to be one possibility for improving the quality of the analyses by identifying the sources of problems within the pre-analytical phase, thus allowing them to be rectified. Additionally, the PAS tool has an educational value and can also be adopted for use in other decentralized laboratories.
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How to conduct External Quality Assessment Schemes for the pre-analytical phase?
Kristensen, Gunn B B; Aakre, Kristin Moberg; Kristoffersen, Ann Helen; Sandberg, Sverre
2014-01-01
In laboratory medicine, several studies have described the most frequent errors in the different phases of the total testing process, and a large proportion of these errors occur in the pre-analytical phase. Schemes for registration of errors and subsequent feedback to the participants have been conducted for decades concerning the analytical phase by External Quality Assessment (EQA) organizations operating in most countries. The aim of the paper is to present an overview of different types of EQA schemes for the pre-analytical phase, and give examples of some existing schemes. So far, very few EQA organizations have focused on the pre-analytical phase, and most EQA organizations do not offer pre-analytical EQA schemes (EQAS). It is more difficult to perform and standardize pre-analytical EQAS and also, accreditation bodies do not ask the laboratories for results from such schemes. However, some ongoing EQA programs for the pre-analytical phase do exist, and some examples are given in this paper. The methods used can be divided into three different types; collecting information about pre-analytical laboratory procedures, circulating real samples to collect information about interferences that might affect the measurement procedure, or register actual laboratory errors and relate these to quality indicators. These three types have different focus and different challenges regarding implementation, and a combination of the three is probably necessary to be able to detect and monitor the wide range of errors occurring in the pre-analytical phase.
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Review of Pre-Analytical Errors in Oral Glucose Tolerance Testing in a Tertiary Care Hospital.
Nanda, Rachita; Patel, Suprava; Sahoo, Sibashish; Mohapatra, Eli
2018-03-13
The pre-pre-analytical and pre-analytical phases form a major chunk of the errors in a laboratory. The process has taken into consideration a very common procedure which is the oral glucose tolerance test to identify the pre-pre-analytical errors. Quality indicators provide evidence of quality, support accountability and help in the decision making of laboratory personnel. The aim of this research is to evaluate pre-analytical performance of the oral glucose tolerance test procedure. An observational study that was conducted overa period of three months, in the phlebotomy and accessioning unit of our laboratory using questionnaire that examined the pre-pre-analytical errors through a scoring system. The pre-analytical phase was analyzed for each sample collected as per seven quality indicators. About 25% of the population gave wrong answer with regard to the question that tested the knowledge of patient preparation. The appropriateness of test result QI-1 had the most error. Although QI-5 for sample collection had a low error rate, it is a very important indicator as any wrongly collected sample can alter the test result. Evaluating the pre-analytical and pre-pre-analytical phase is essential and must be conducted routinely on a yearly basis to identify errors and take corrective action and to facilitate their gradual introduction into routine practice.
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Courtade-Saïdi, Monique; Fleury Feith, Jocelyne
2015-10-01
The pre-analytical step includes sample collection, preparation, transportation and storage in the pathology unit where the diagnosis is performed. The pathologist ensures that pre-analytical conditions are in line with expectations. The lack of standardization for handling cytological samples makes this pre-analytical step difficult to harmonize. Moreover, this step depends on the nature of the sample: fresh liquid or fixed material, air-dried smears, liquid-based cytology. The aim of the study was to review the different practices in French structures of pathology on the pre-analytical phase concerning cytological fluids such as broncho-alveolar lavage (BALF), serous fluids and urine. A survey was conducted on the basis of the pre-analytical chapter of the ISO 15189 and sent to 191 French pathological structures (105 public and 86 private). Fifty-six laboratories replied to the survey. Ninety-five per cent have a computerized management system and 70% a manual on sample handling. The general instructions requested for the patients and sample identification were highly correctly filled with a short time routing and additional tests prescription. By contrast, information are variable concerning the clinical information requested and the type of tubes for collecting fluids and the volumes required as well as the actions taken in case of non-conformity. For the specific items concerning BALF, serous fluids and urine, this survey has shown a great heterogeneity according to sample collection, fixation and of clinical information. This survey demonstrates that the pre-analytical quality for BALF, serous fluids and urine is not optimal and that some corrections of the practices are recommended with a standardization of numerous steps in order to increase the reproducibility of additional tests such as immunocytochemistry, cytogenetic and molecular biology. Some recommendations have been written. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
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42 CFR 493.1249 - Standard: Preanalytic systems quality assessment.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 5 2010-10-01 2010-10-01 false Standard: Preanalytic systems quality assessment... Nonwaived Testing Preanalytic Systems § 493.1249 Standard: Preanalytic systems quality assessment. (a) The....1241 through 493.1242. (b) The preanalytic systems quality assessment must include a review of the...
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Current projects in Pre-analytics: where to go?
Sapino, Anna; Annaratone, Laura; Marchiò, Caterina
2015-01-01
The current clinical practice of tissue handling and sample preparation is multifaceted and lacks strict standardisation: this scenario leads to significant variability in the quality of clinical samples. Poor tissue preservation has a detrimental effect thus leading to morphological artefacts, hampering the reproducibility of immunocytochemical and molecular diagnostic results (protein expression, DNA gene mutations, RNA gene expression) and affecting the research outcomes with irreproducible gene expression and post-transcriptional data. Altogether, this limits the opportunity to share and pool national databases into European common databases. At the European level, standardization of pre-analytical steps is just at the beginning and issues regarding bio-specimen collection and management are still debated. A joint (public-private) project entitled on standardization of tissue handling in pre-analytical procedures has been recently funded in Italy with the aim of proposing novel approaches to the neglected issue of pre-analytical procedures. In this chapter, we will show how investing in pre-analytics may impact both public health problems and practical innovation in solid tumour processing.
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Impact of Educational Activities in Reducing Pre-Analytical Laboratory Errors: A quality initiative.
Al-Ghaithi, Hamed; Pathare, Anil; Al-Mamari, Sahimah; Villacrucis, Rodrigo; Fawaz, Naglaa; Alkindi, Salam
2017-08-01
Pre-analytic errors during diagnostic laboratory investigations can lead to increased patient morbidity and mortality. This study aimed to ascertain the effect of educational nursing activities on the incidence of pre-analytical errors resulting in non-conforming blood samples. This study was conducted between January 2008 and December 2015. All specimens received at the Haematology Laboratory of the Sultan Qaboos University Hospital, Muscat, Oman, during this period were prospectively collected and analysed. Similar data from 2007 were collected retrospectively and used as a baseline for comparison. Non-conforming samples were defined as either clotted samples, haemolysed samples, use of the wrong anticoagulant, insufficient quantities of blood collected, incorrect/lack of labelling on a sample or lack of delivery of a sample in spite of a sample request. From 2008 onwards, multiple educational training activities directed at the hospital nursing staff and nursing students primarily responsible for blood collection were implemented on a regular basis. After initiating corrective measures in 2008, a progressive reduction in the percentage of non-conforming samples was observed from 2009 onwards. Despite a 127.84% increase in the total number of specimens received, there was a significant reduction in non-conforming samples from 0.29% in 2007 to 0.07% in 2015, resulting in an improvement of 75.86% ( P <0.050). In particular, specimen identification errors decreased by 0.056%, with a 96.55% improvement. Targeted educational activities directed primarily towards hospital nursing staff had a positive impact on the quality of laboratory specimens by significantly reducing pre-analytical errors.
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Keşapli, Mustafa; Aydin, Özgür; Esen, Hatice; Yeğin, Ayşenur; Güngör, Faruk; Yilmaz, Necat
2016-01-01
Summary Background After the introduction of modern laboratory instruments and information systems, preanalytic phase is the new field of battle. Errors in preanalytical phase account for approximately half of total errors in clinical laboratory. The objective of this study was to share an experience of an education program that was believed to be successful in decreasing the number of rejected samples received from the Emergency Department (ED). Methods An education program about laboratory procedures, quality requirements in the laboratory, patient and health-care worker safety was planned by the quality team to be performed on 36 people who were responsible for sample collection in the ED. A questionary which included 11 questions about the preanalytic phase was applied to all the attendees before and after training. The number of rejected samples per million was discovered with right proportion account over the number of accepted and rejected samples to laboratory after and before the training period. Results Most of the attendees were nurses (n: 22/55%), with over 12 years of experience in general and 2–4 years experience in the ED. Knowledge level of the attendees was calculated before training as 58.9% and after training as 91.8%. While the total rate of sample rejection before training was 2.35% (sigma value 3.37–3.50), the rate after training was 1.56% (sigma value 3.62–3.75). Conclusions Increasing the knowledge of staff has a direct positive impact on the preanalytic phase. The application of a pre-test was observed to be a feasible tool to shape group specific education programs. PMID:28356887
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Aykal, Güzin; Keşapli, Mustafa; Aydin, Özgür; Esen, Hatice; Yeğin, Ayşenur; Güngör, Faruk; Yilmaz, Necat
2016-09-01
After the introduction of modern laboratory instruments and information systems, preanalytic phase is the new field of battle. Errors in preanalytical phase account for approximately half of total errors in clinical laboratory. The objective of this study was to share an experience of an education program that was believed to be successful in decreasing the number of rejected samples received from the Emergency Department (ED). An education program about laboratory procedures, quality requirements in the laboratory, patient and health-care worker safety was planned by the quality team to be performed on 36 people who were responsible for sample collection in the ED. A questionary which included 11 questions about the preanalytic phase was applied to all the attendees before and after training. The number of rejected samples per million was discovered with right proportion account over the number of accepted and rejected samples to laboratory after and before the training period. Most of the attendees were nurses (n: 22/55%), with over 12 years of experience in general and 2-4 years experience in the ED. Knowledge level of the attendees was calculated before training as 58.9% and after training as 91.8%. While the total rate of sample rejection before training was 2.35% (sigma value 3.37-3.50), the rate after training was 1.56% (sigma value 3.62-3.75). Increasing the knowledge of staff has a direct positive impact on the preanalytic phase. The application of a pre-test was observed to be a feasible tool to shape group specific education programs.
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Nikolac, Nora; Krleza, Jasna Lenicek; Simundic, Ana-Maria
2017-02-15
The aim of this paper is to present results of first two years of preanalytical external quality assessment (EQA) in Croatia. This paper summarizes results from 6 rounds of preanalytical EQA during 2014-2016 in 161-175 Croatian laboratories (number ranged between cycles). EQA was designed as an online survey of the compliance with National recommendations for phlebotomy (NRP). Forty-seven questions in 5 categories are analyzed (materials and equipment, patient identification, patient preparation, sampling and storage). Additionally, preanalytical cases are presented. Overall performance scores (Question score (Qscore) for compliance with NRP and Case score (Cscore) for preanalytical cases) are calculated for each question/case as a proportion of laboratories with satisfactory procedure (x 100). Qscores and Cscores ≥ 70 were classified as acceptable (maximal score = 100). In investigation of compliance with NRP, acceptable Qscores were obtained for 34/47 questions. The lowest scores were observed for the availability of sterile disposable tourniquets (Qscore = 15) and safe-sharp needles (Qscore = 34), obtaining patients address as an identifier (Qscore = 21), using glycolysis inhibitor tubes for glucose concentration measurement (Qscore = 21) and verification of manufacturers declarations on temperature and time of storage (Qscore = 31). There was no statistically significant difference in overall Qscore according to different categories of phlebotomy procedures (P = 0.284). The results of preanalytical cases showed acceptable Cscore values for all cases (89-96). First two years of preanalytical EQA showed good compliance with the NRP and excellent expertise in resolving complex preanalytical issues. Major critical spots are lack of availability of safe-sharp needles, disposable tourniquets and glucose inhibitor tubes.
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Nikolac, Nora; Krleza, Jasna Lenicek; Simundic, Ana-Maria
2017-01-01
Introduction The aim of this paper is to present results of first two years of preanalytical external quality assessment (EQA) in Croatia. Materials and methods This paper summarizes results from 6 rounds of preanalytical EQA during 2014-2016 in 161-175 Croatian laboratories (number ranged between cycles). EQA was designed as an online survey of the compliance with National recommendations for phlebotomy (NRP). Forty-seven questions in 5 categories are analyzed (materials and equipment, patient identification, patient preparation, sampling and storage). Additionally, preanalytical cases are presented. Overall performance scores (Question score (Qscore) for compliance with NRP and Case score (Cscore) for preanalytical cases) are calculated for each question/case as a proportion of laboratories with satisfactory procedure (x 100). Qscores and Cscores ≥ 70 were classified as acceptable (maximal score = 100). Results In investigation of compliance with NRP, acceptable Qscores were obtained for 34/47 questions. The lowest scores were observed for the availability of sterile disposable tourniquets (Qscore = 15) and safe-sharp needles (Qscore = 34), obtaining patients address as an identifier (Qscore = 21), using glycolysis inhibitor tubes for glucose concentration measurement (Qscore = 21) and verification of manufacturers declarations on temperature and time of storage (Qscore = 31). There was no statistically significant difference in overall Qscore according to different categories of phlebotomy procedures (P = 0.284). The results of preanalytical cases showed acceptable Cscore values for all cases (89-96). Conclusion First two years of preanalytical EQA showed good compliance with the NRP and excellent expertise in resolving complex preanalytical issues. Major critical spots are lack of availability of safe-sharp needles, disposable tourniquets and glucose inhibitor tubes. PMID:28392736
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Bernini, Patrizia; Bertini, Ivano; Luchinat, Claudio; Nincheri, Paola; Staderini, Samuele; Turano, Paola
2011-04-01
(1)H NMR metabolic profiling of urine, serum and plasma has been used to monitor the impact of the pre-analytical steps on the sample quality and stability in order to propose standard operating procedures (SOPs) for deposition in biobanks. We analyzed the quality of serum and plasma samples as a function of the elapsed time (t = 0-4 h) between blood collection and processing and of the time from processing to freezing (up to 24 h). The stability of the urine metabolic profile over time (up to 24 h) at various storage temperatures was monitored as a function of the different pre-analytical treatments like pre-storage centrifugation, filtration, and addition of the bacteriostatic preservative sodium azide. Appreciable changes in the profiles, reflecting changes in the concentration of a number of metabolites, were detected and discussed in terms of chemical and enzymatic reactions for both blood and urine samples. Appropriate procedures for blood derivatives collection and urine preservation/storage that allow maintaining as much as possible the original metabolic profile of the fresh samples emerge, and are proposed as SOPs for biobanking.
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MacGrogan, Gaëtan; Mathieu, Marie-Christine; Poulet, Bruno; Penault-Llorca, Frédérique; Vincent-Salomon, Anne; Roger, Pascal; Treilleux, Isabelle; Valent, Alexander; Antoine, Martine; Becette, Véronique; Bor, Catherine; Brabencova, Eva; Charafe-Jauffret, Emmanuelle; Chenard, Marie-Pierre; Dauplat, Marie-Mélanie; Delrée, Paul; Devouassoux, Mojgan; Fiche, Maryse; Fondrevelle, Marie-Eve; Fridman, Viviana; Garbar, Christian; Genin, Pascal; Ghnassia, Jean-Pierre; Haudebourg, Juliette; Laberge-Le Couteulx, Sophie; Loussouarn, Delphine; Maran-Gonzalez, Aurélie; Marcy, Myriam; Michenet, Patrick; Sagan, Christine; Trassard, Martine; Verriele, Véronique; Arnould, Laurent; Lacroix-Triki, Magali
2014-10-01
Biomarker assessment of breast cancer tumor samples is part of the routine workflow of pathology laboratories. International guidelines have recently been updated, with special regards to the pre-analytical steps that are critical for the quality of immunohistochemical and in situ hybridization procedures, whatever the biomarker analyzed. Fixation and specimen handling protocols must be standardized, validated and carefully tracked. Cooperation and training of the personnel involved in the specimen workflow (e.g. radiologists, surgeons, nurses, technicians and pathologists) are of paramount importance. The GEFPICS' update of the recommendations herein details and comments the different steps of the pre-analytical process. Application of these guidelines and participation to quality insurance programs are mandatory to ensure the correct evaluation of oncotheranostic biomarkers. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
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Ten years of preanalytical monitoring and control: Synthetic Balanced Score Card Indicator
López-Garrigós, Maite; Flores, Emilio; Santo-Quiles, Ana; Gutierrez, Mercedes; Lugo, Javier; Lillo, Rosa; Leiva-Salinas, Carlos
2015-01-01
Introduction Preanalytical control and monitoring continue to be an important issue for clinical laboratory professionals. The aim of the study was to evaluate a monitoring system of preanalytical errors regarding not suitable samples for analysis, based on different indicators; to compare such indicators in different phlebotomy centres; and finally to evaluate a single synthetic preanalytical indicator that may be included in the balanced scorecard management system (BSC). Materials and methods We collected individual and global preanalytical errors in haematology, coagulation, chemistry, and urine samples analysis. We also analyzed a synthetic indicator that represents the sum of all types of preanalytical errors, expressed in a sigma level. We studied the evolution of those indicators over time and compared indicator results by way of the comparison of proportions and Chi-square. Results There was a decrease in the number of errors along the years (P < 0.001). This pattern was confirmed in primary care patients, inpatients and outpatients. In blood samples, fewer errors occurred in outpatients, followed by inpatients. Conclusion We present a practical and effective methodology to monitor unsuitable sample preanalytical errors. The synthetic indicator results summarize overall preanalytical sample errors, and can be used as part of BSC management system. PMID:25672466
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West, Jamie; Atherton, Jennifer; Costelloe, Seán J; Pourmahram, Ghazaleh; Stretton, Adam; Cornes, Michael
2017-01-01
Preanalytical errors have previously been shown to contribute a significant proportion of errors in laboratory processes and contribute to a number of patient safety risks. Accreditation against ISO 15189:2012 requires that laboratory Quality Management Systems consider the impact of preanalytical processes in areas such as the identification and control of non-conformances, continual improvement, internal audit and quality indicators. Previous studies have shown that there is a wide variation in the definition, repertoire and collection methods for preanalytical quality indicators. The International Federation of Clinical Chemistry Working Group on Laboratory Errors and Patient Safety has defined a number of quality indicators for the preanalytical stage, and the adoption of harmonized definitions will support interlaboratory comparisons and continual improvement. There are a variety of data collection methods, including audit, manual recording processes, incident reporting mechanisms and laboratory information systems. Quality management processes such as benchmarking, statistical process control, Pareto analysis and failure mode and effect analysis can be used to review data and should be incorporated into clinical governance mechanisms. In this paper, The Association for Clinical Biochemistry and Laboratory Medicine PreAnalytical Specialist Interest Group review the various data collection methods available. Our recommendation is the use of the laboratory information management systems as a recording mechanism for preanalytical errors as this provides the easiest and most standardized mechanism of data capture.
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The focus on sample quality: Influence of colon tissue collection on reliability of qPCR data
Korenkova, Vlasta; Slyskova, Jana; Novosadova, Vendula; Pizzamiglio, Sara; Langerova, Lucie; Bjorkman, Jens; Vycital, Ondrej; Liska, Vaclav; Levy, Miroslav; Veskrna, Karel; Vodicka, Pavel; Vodickova, Ludmila; Kubista, Mikael; Verderio, Paolo
2016-01-01
Successful molecular analyses of human solid tissues require intact biological material with well-preserved nucleic acids, proteins, and other cell structures. Pre-analytical handling, comprising of the collection of material at the operating theatre, is among the first critical steps that influence sample quality. The aim of this study was to compare the experimental outcomes obtained from samples collected and stored by the conventional means of snap freezing and by PAXgene Tissue System (Qiagen). These approaches were evaluated by measuring rRNA and mRNA integrity of the samples (RNA Quality Indicator and Differential Amplification Method) and by gene expression profiling. The collection procedures of the biological material were implemented in two hospitals during colon cancer surgery in order to identify the impact of the collection method on the experimental outcome. Our study shows that the pre-analytical sample handling has a significant effect on the quality of RNA and on the variability of qPCR data. PAXgene collection mode proved to be more easily implemented in the operating room and moreover the quality of RNA obtained from human colon tissues by this method is superior to the one obtained by snap freezing. PMID:27383461
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Impact of Educational Activities in Reducing Pre-Analytical Laboratory Errors
Al-Ghaithi, Hamed; Pathare, Anil; Al-Mamari, Sahimah; Villacrucis, Rodrigo; Fawaz, Naglaa; Alkindi, Salam
2017-01-01
Objectives Pre-analytic errors during diagnostic laboratory investigations can lead to increased patient morbidity and mortality. This study aimed to ascertain the effect of educational nursing activities on the incidence of pre-analytical errors resulting in non-conforming blood samples. Methods This study was conducted between January 2008 and December 2015. All specimens received at the Haematology Laboratory of the Sultan Qaboos University Hospital, Muscat, Oman, during this period were prospectively collected and analysed. Similar data from 2007 were collected retrospectively and used as a baseline for comparison. Non-conforming samples were defined as either clotted samples, haemolysed samples, use of the wrong anticoagulant, insufficient quantities of blood collected, incorrect/lack of labelling on a sample or lack of delivery of a sample in spite of a sample request. From 2008 onwards, multiple educational training activities directed at the hospital nursing staff and nursing students primarily responsible for blood collection were implemented on a regular basis. Results After initiating corrective measures in 2008, a progressive reduction in the percentage of non-conforming samples was observed from 2009 onwards. Despite a 127.84% increase in the total number of specimens received, there was a significant reduction in non-conforming samples from 0.29% in 2007 to 0.07% in 2015, resulting in an improvement of 75.86% (P <0.050). In particular, specimen identification errors decreased by 0.056%, with a 96.55% improvement. Conclusion Targeted educational activities directed primarily towards hospital nursing staff had a positive impact on the quality of laboratory specimens by significantly reducing pre-analytical errors. PMID:29062553
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Lippi, Giuseppe; Baird, Geoffrey S; Banfi, Giuseppe; Bölenius, Karin; Cadamuro, Janne; Church, Stephen; Cornes, Michael P; Dacey, Anna; Guillon, Antoine; Hoffmann, Georg; Nybo, Mads; Premawardhana, Lakdasa Devananda; Salinas, María; Sandberg, Sverre; Slingerland, Robbert; Stankovic, Ana; Sverresdotter, Sylte Marit; Vermeersch, Pieter; Simundic, Ana-Maria
2017-03-01
It is now undeniable that laboratory testing is vital for the diagnosis, prognostication and therapeutic monitoring of human disease. Despite the many advances made for achieving a high degree of quality and safety in the analytical part of diagnostic testing, many hurdles in the total testing process remain, especially in the preanalytical phase ranging from test ordering to obtaining and managing the biological specimens. The Working Group for the Preanalytical Phase (WG-PRE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has planned many activities aimed at mitigating the vulnerability of the preanalytical phase, including the organization of three European meetings in the past 7 years. Hence, this collective article follows the previous three opinion papers that were published by the EFLM WGPRE on the same topic, and brings together the summaries of the presentations that will be given at the 4th EFLM-BD meeting "Improving quality in the preanalytical phase through innovation" in Amsterdam, 24-25 March, 2017.
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Preanalytical requirements of urinalysis
Delanghe, Joris; Speeckaert, Marijn
2014-01-01
Urine may be a waste product, but it contains an enormous amount of information. Well-standardized procedures for collection, transport, sample preparation and analysis should become the basis of an effective diagnostic strategy for urinalysis. As reproducibility of urinalysis has been greatly improved due to recent technological progress, preanalytical requirements of urinalysis have gained importance and have become stricter. Since the patients themselves often sample urine specimens, urinalysis is very susceptible to preanalytical issues. Various sampling methods and inappropriate specimen transport can cause important preanalytical errors. The use of preservatives may be helpful for particular analytes. Unfortunately, a universal preservative that allows a complete urinalysis does not (yet) exist. The preanalytical aspects are also of major importance for newer applications (e.g. metabolomics). The present review deals with the current preanalytical problems and requirements for the most common urinary analytes. PMID:24627718
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Is a pre-analytical process for urinalysis required?
Petit, Morgane; Beaudeux, Jean-Louis; Majoux, Sandrine; Hennequin, Carole
2017-10-01
For the reliable urinary measurement of calcium, phosphate and uric acid, a pre-analytical process by adding acid or base to urine samples at laboratory is recommended in order to dissolve precipitated solutes. Several studies on different kind of samples and analysers have previously shown that a such pre-analytical treatment is useless. The objective was to study the necessity of pre-analytical treatment of urine on samples collected using the V-Monovette ® (Sarstedt) system and measured on the analyser Architect C16000 (Abbott Diagnostics). Sixty urinary samples of hospitalized patients were selected (n=30 for calcium and phosphate, and n=30 for uric acid). After acidification of urine samples for measurement of calcium and phosphate, and alkalinisation for measurement of uric acid respectively, differences between results before and after the pre-analytical treatment were compared to acceptable limits recommended by the French society of clinical biology (SFBC). No difference in concentration between before and after pre-analytical treatment of urine samples exceeded acceptable limits from SFBC for measurement of calcium and uric acid. For phosphate, only one sample exceeded these acceptable limits, showing a result paradoxically lower after acidification. In conclusion, in agreement with previous study, our results show that acidification or alkalinisation of urine samples from 24 h urines or from urination is not a pre-analytical necessity for measurement of calcium, phosphate and uric acid.
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Comazzi, S; Cozzi, M; Bernardi, S; Zanella, D R; Aresu, L; Stefanello, D; Marconato, L; Martini, V
2018-02-01
Flow cytometry (FC) is increasingly being used for immunophenotyping and staging of canine lymphoma. The aim of this retrospective study was to assess pre-analytical variables that might influence the diagnostic utility of FC of lymph node (LN) fine needle aspirate (FNA) specimens from dogs with lymphoproliferative diseases. The study included 987 cases with LN FNA specimens sent for immunophenotyping that were submitted to a diagnostic laboratory in Italy from 2009 to 2015. Cases were grouped into 'diagnostic' and 'non-diagnostic'. Pre-analytical factors analysed by univariate and multivariate analyses were animal-related factors (breed, age, sex, size), operator-related factors (year, season, shipping method, submitting veterinarian) and sample-related factors (type of sample material, cellular concentration, cytological smears, artefacts). The submitting veterinarian, sample material, sample cellularity and artefacts affected the likelihood of having a diagnostic sample. The availability of specimens from different sites and of cytological smears increased the odds of obtaining a diagnostic result. Major artefacts affecting diagnostic utility included poor cellularity and the presence of dead cells. Flow cytometry on LN FNA samples yielded conclusive results in more than 90% of cases with adequate sample quality and sampling conditions. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Findeisen, Peter; Thumfart, Jörg Oliver; Costina, Victor; Hofheinz, Ralf; Neumaier, Michael
2013-09-01
To determine the preanalytical quality of serum and plasma by monitoring the time-dependent ex vivo decay of a synthetic reporter peptide (RP) with liquid chromatography/mass spectrometry (LC/MS). Serum and plasma specimens were spiked with the RP and proteolytic fragments were monitored with LC/MS at different preanalytical time points ranging from 2 to 24 hours after blood withdrawal. The concentration of fragments changed in a time-dependent manner, and respective peptide profiles were used to classify specimens according to their preanalytical time span. Classification accuracy was high, with values always above 0.89 for areas under receiver operating characteristic curves. This "proteomics degradation clock" can be used to estimate the preanalytical quality of serum and plasma and might have impact on quality control procedures of biobanking repositories.
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David, Remona E; Dobreanu, Minodora
2016-01-01
Development of quality measurement principles is a strategic point for each clinical laboratory. Preexamination process is the most critical and the most difficult to be managed. The aim of this study is to identify, quantify, and monitor the nonconformities of the pre-analytical process using quality indicators that can affect the patient's health safety in four different locations of a Romanian private clinical laboratory. The study group consisted of all the analysis requests received by the departments of biochemistry, hematology, and coagulation from January through March 2015. In order to collect the pre-analytical nonconformities, we created a "Risk Budget", using the entries from the "Evidence notebook--non-conform samples" from the above mentioned departments. The laboratory established the quality indicators by means of the risk management technique in order to identify and control the sources of errors, FMEA (Failure Modes and Effects Analyses), which had been implemented and monitored for its purposes and special needs. For the assessment of the control level over the processes, the results were transformed on the Six Sigma scale, using the Westgard calculation method and being obtained in this way the frequency with which an error may occur. (https://www.westgard. com/six-sigma-calculators.htm). The obtained results prove that the quantification and monitoring of the indicators can be a control instrument for the pre-analytic activities. The calculation of the Six Sigma value adds extra information to the study because it allows the detection of the processes which need improvement (Sigma value higher than 4 represents a well controlled process). The highest rates were observed for the hemolyzed and the lipemic samples, in the department of biochemistry and hemolyzed, insufficient sample volume, or clotted samples for the department of hematology and coagulation. Significant statistical differences between laboratories participating in the study have been recorded for these indicators. The elaborated study between the four branches of a Romanian private clinical laboratory was a challenge, and it helped in choosing strategic decisions regarding the improvement of the patient's health safety in the institution, corresponding to the accreditation requirements in accordance with ISO 15189:2013.
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The preanalytic phase in veterinary clinical pathology.
Braun, Jean-Pierre; Bourgès-Abella, Nathalie; Geffré, Anne; Concordet, Didier; Trumel, Cathy
2015-03-01
This article presents the general causes of preanalytic variability with a few examples showing specialists and practitioners that special and improved care should be given to this too often neglected phase. The preanalytic phase of clinical pathology includes all the steps from specimen collection to analysis. It is the phase where most laboratory errors occur in human, and probably also in veterinary clinical pathology. Numerous causes may affect the validity of the results, including technical factors, such as the choice of anticoagulant, the blood vessel sampled, and the duration and conditions of specimen handling. While the latter factors can be defined, influence of biologic and physiologic factors such as feeding and fasting, stress, and biologic and endocrine rhythms can often not be controlled. Nevertheless, as many factors as possible should at least be documented. The importance of the preanalytic phase is often not given the necessary attention, although the validity of the results and consequent clinical decision making and medical management of animal patients would likely be improved if the quality of specimens submitted to the laboratory was optimized. © 2014 American Society for Veterinary Clinical Pathology.
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Inpatient preanalytic process improvements.
Wagar, Elizabeth A; Phipps, Ron; Del Guidice, Robert; Middleton, Lavinia P; Bingham, John; Prejean, Cheryl; Johnson-Hamilton, Martha; Philip, Pheba; Le, Ngoc Han; Muses, Waheed
2013-12-01
Phlebotomy services are a common target for preanalytic improvements. Many new, quality engineering tools have recently been applied in clinical laboratories. However, data on relatively few projects have been published. This example describes a complete application of current, quality engineering tools to improve preanalytic phlebotomy services. To decrease the response time in the preanalytic inpatient laboratory by 25%, to reduce the number of incident reports related to preanalytic phlebotomy, and to make systematic process changes that satisfied the stakeholders. The Department of Laboratory Medicine, General Services Section, at the University of Texas MD Anderson Cancer Center (Houston) is responsible for inpatient phlebotomy in a 24-hour operation, which serves 689 inpatient beds. The study director was project director of the Division of Pathology and Laboratory Medicine's Quality Improvement Section and was assisted by 2 quality technologists and an industrial engineer from MD Anderson Office of Performance Improvement. After implementing each solution, using well-recognized, quality tools and metrics, the response time for blood collection decreased by 23%, which was close to meeting the original responsiveness goal of 25%. The response time between collection and arrival in the laboratory decreased by 8%. Applicable laboratory-related incident reports were reduced by 43%. Comprehensive application of quality tools, such as statistical control charts, Pareto diagrams, value-stream maps, process failure modes and effects analyses, fishbone diagrams, solution prioritization matrices, and customer satisfaction surveys can significantly improve preset goals for inpatient phlebotomy.
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Does laboratory automation for the preanalytical phase improve data quality?
Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Montagnana, Martina; Brocco, Giorgio; Voi, Monica; Picheth, Geraldo; Guidi, Gian Cesare
2013-10-01
Our aim was to evaluate whether automation for the preanalytical phase improves data quality. Blood from 100 volunteers was collected into two vacuum tubes. One sample from each volunteer was respectively assigned to (G1) traditional processing, starting with centrifugation at 1200 g for 10 min, and (G2) the MODULAR PRE-ANALYTICALS EVO-MPA system. The routine clinical chemistry tests were performed in duplicate on the same instrument Cobas 6000
module. G1 samples were uncapped manually and immediately placed into the instrument. G2 samples were directly fed from the MPA system to the instrument without further staff intervention. At the end, (1) the G1 samples were stored for 6 h at 4 °C as prescribed in our accredited laboratory and (2) the G2 samples were stored for 6 h in the MPA output buffer. Results from G1 and G2, before and after storage, were compared. Significant increases were observed in G1 compared with G2 samples as follows: (1) before storage for alkaline phosphatase (ALP), lactate dehydrogenase (LDH), phosphate (P), magnesium (MG), iron (FE), and hemolysis index and (2) after storage for total cholesterol (COL), triglycerides (TG), total protein (TP), albumin (ALB), blood urea nitrogen (BUN), creatinine (CRE), uric acid (UA), ALP, pancreatic amylase, aspartate aminotransferase (AST), alanine aminotransferase (ALT), g-glutamyltransferase (GGT), LDH, creatine kinase (CK), calcium (CA), FE, sodium (NA), potassium (K), and hemolysis index. Moreover, significant increases were observed in (3) G1-after versus G1-before storage samples for COL, high-density lipoprotein cholesterol, TG, TP, ALB, BUN, CRE, UA, AST, ALT, GGT, LDH, P, CA, MG, FE, NA, K, and hemolysis index and (4) G2-after versus G2-before storage only for BUN, AST, LDH, P, and CA. In conclusion, our results show that the MPA system improves the quality of laboratory testing. -
Exhaled breath condensate – from an analytical point of view
Dodig, Slavica; Čepelak, Ivana
2013-01-01
Over the past three decades, the goal of many researchers is analysis of exhaled breath condensate (EBC) as noninvasively obtained sample. A total quality in laboratory diagnostic processes in EBC analysis was investigated: pre-analytical (formation, collection, storage of EBC), analytical (sensitivity of applied methods, standardization) and post-analytical (interpretation of results) phases. EBC analysis is still used as a research tool. Limitations referred to pre-analytical, analytical, and post-analytical phases of EBC analysis are numerous, e.g. low concentrations of EBC constituents, single-analyte methods lack in sensitivity, and multi-analyte has not been fully explored, and reference values are not established. When all, pre-analytical, analytical and post-analytical requirements are met, EBC biomarkers as well as biomarker patterns can be selected and EBC analysis can hopefully be used in clinical practice, in both, the diagnosis and in the longitudinal follow-up of patients, resulting in better outcome of disease. PMID:24266297
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Delaby, Constance; Gabelle, Audrey; Meynier, Philippe; Loubiere, Vincent; Vialaret, Jérôme; Tiers, Laurent; Ducos, Jacques; Hirtz, Christophe; Lehmann, Sylvain
2014-05-01
The use of dried blood spots on filter paper is well documented as an affordable and practical alternative to classical venous sampling for various clinical needs. This technique has indeed many advantages in terms of collection, biological safety, storage, and shipment. Amyloid β (Aβ) peptides are useful cerebrospinal fluid (CSF) biomarkers for Alzheimer disease diagnosis. However, Aβ determination is hindered by preanalytical difficulties in terms of sample collection and stability in tubes. We compared the quantification of Aβ peptides (1-40, 1-42, and 1-38) by simplex and multiplex ELISA, following either a standard operator method (liquid direct quantification) or after spotting CSF onto dried matrix paper card. The use of dried matrix spot (DMS) overcame preanalytical problems and allowed the determination of Aβ concentrations that were highly commutable (Bland-Altman) with those obtained using CSF in classical tubes. Moreover, we found a positive and significant correlation (r2=0.83, Pearson coefficient p=0.0329) between the two approaches. This new DMS method for CSF represents an interesting alternative that increases the quality and efficiency in preanalytics. This should enable the better exploitation of Aβ analytes for Alzheimer's diagnosis.
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Warth, Arne; Muley, Thomas; Meister, Michael; Weichert, Wilko
2015-01-01
Preanalytic sampling techniques and preparation of tissue specimens strongly influence analytical results in lung tissue diagnostics both on the morphological but also on the molecular level. However, in contrast to analytics where tremendous achievements in the last decade have led to a whole new portfolio of test methods, developments in preanalytics have been minimal. This is specifically unfortunate in lung cancer, where usually only small amounts of tissue are at hand and optimization in all processing steps is mandatory in order to increase the diagnostic yield. In the following, we provide a comprehensive overview on some aspects of preanalytics in lung cancer from the method of sampling over tissue processing to its impact on analytical test results. We specifically discuss the role of preanalytics in novel technologies like next-generation sequencing and in the state-of the-art cytology preparations. In addition, we point out specific problems in preanalytics which hamper further developments in the field of lung tissue diagnostics.
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Lombardi, Giovanni; Sansoni, Veronica; Banfi, Giuseppe
2017-08-01
In the last few years, a growing number of molecules have been associated to an endocrine function of the skeletal muscle. Circulating myokine levels, in turn, have been associated with several pathophysiological conditions including the cardiovascular ones. However, data from different studies are often not completely comparable or even discordant. This would be due, at least in part, to the whole set of situations related to the preparation of the patient prior to blood sampling, blood sampling procedure, processing and/or store. This entire process constitutes the pre-analytical phase. The importance of the pre-analytical phase is often not considered. However, in routine diagnostics, the 70% of the errors are in this phase. Moreover, errors during the pre-analytical phase are carried over in the analytical phase and affects the final output. In research, for example, when samples are collected over a long time and by different laboratories, a standardized procedure for sample collecting and the correct procedure for sample storage are acknowledged. In this review, we discuss the pre-analytical variables potentially affecting the measurement of myokines with cardiovascular functions.
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Willems, Elise; Smismans, Annick; Cartuyvels, Reinoud; Coppens, Guy; Van Vaerenbergh, Kristien; Van den Abeele, Anne-Marie; Frans, Johan
2012-05-01
Bloodstream infections remain a major challenge in medicine. Optimal detection of pathogens is only possible if the quality of preanalytical factors is thoroughly controlled. Since the laboratory is responsible for this preanalytical phase, the quality control of critical factors should be integrated in its quality control program. The numerous recommendations regarding blood culture collection contain controversies. Only an unambiguous guideline permits standardization and interlaboratory quality control. We present an evidence-based concise guideline of critical preanalytical determinants for blood culture collection and summarize key performance indicators with their concomitant target values. In an attempt to benchmark, we compared the true-positive rate, contamination rate, and collected blood volume of blood culture bottles in 5 Belgian hospital laboratories. The true-positive blood culture rate fell within previously defined acceptation criteria by Baron et al. (2005) in all 5 hospitals, whereas the contamination rate exceeded the target value in 4 locations. Most unexpected, in each of the 5 laboratories, more than one third of the blood culture bottles were incorrectly filled, irrespective of the manufacturer of the blood culture vials. As a consequence of this shortcoming, one manufacturer recently developed an automatic blood volume monitoring system. In conclusion, clear recommendations for standardized blood culture collection combined with quality control of critical factors of the preanalytical phase are essential for diagnostic blood culture improvement. Copyright © 2012 Elsevier Inc. All rights reserved.
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Bhushan, Ravi; Sen, Arijit
2017-04-01
Very few Indian studies exist on evaluation of pre-analytical variables affecting "Prothrombin Time" the commonest coagulation assay performed. The study was performed in an Indian tertiary care setting with an aim to assess quantitatively the prevalence of pre-analytical variables and their effects on the results (patient safety), for Prothrombin time test. The study also evaluated their effects on the result and whether intervention, did correct the results. The firstly evaluated the prevalence for various pre-analytical variables detected in samples sent for Prothrombin Time testing. These samples with the detected variables wherever possible were tested and result noted. The samples from the same patients were repeated and retested ensuring that no pre-analytical variable is present. The results were again noted to check for difference the intervention produced. The study evaluated 9989 samples received for PT/INR over a period of 18 months. The prevalence of different pre-analytical variables was found to be 862 (8.63%). The proportion of various pre-analytical variables detected were haemolysed samples 515 (5.16%), over filled vacutainers 62 (0.62%), under filled vacutainers 39 (0.39%), low values 205 (2.05%), clotted samples 11 (0.11%), wrong labeling 4 (0.04%), wrong vacutainer use 2 (0.02%), chylous samples 7 (0.07%) and samples with more than one variable 17 (0.17%). The comparison of percentage of samples showing errors were noted for the first variables since they could be tested with and without the variable in place. The reduction in error percentage was 91.5%, 69.2%, 81.5% and 95.4% post intervention for haemolysed, overfilled, under filled and samples collected with excess pressure at phlebotomy respectively. Correcting the variables did reduce the error percentage to a great extent in these four variables and hence the variables are found to affect "Prothrombin Time" testing and can hamper patient safety.
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Dukic, Lora; Jokic, Anja; Kules, Josipa; Pasalic, Daria
2016-01-01
The educational program for health care personnel is important for reducing preanalytical errors and improving quality of laboratory test results. The aim of our study was to assess the level of knowledge on preanalytical phase in population of biomedicine students through a cross-sectional survey. A survey was sent to students on penultimate and final year of Faculty of Pharmacy and Biochemistry--study of medical biochemistry (FPB), Faculty of Veterinary Medicine (FVM) and School of Medicine (SM), University of Zagreb, Croatia, using the web tool SurveyMonkey. Survey was composed of demographics and 14 statements regarding the preanalytical phase of laboratory testing. Comparison of frequencies and proportions of correct answers was done with Fisher's exact test and test of comparison of proportions, respectively. Study included 135 participants, median age 24 (23-40) years. Students from FPB had higher proportion of correct answers (86%) compared to students from other biomedical faculties 62%, P < 0.001. Students from FPB were more conscious of the importance of specimen mixing (P = 0.027), prevalence of preanalytical errors (P = 0.001), impact of hemolysis (P = 0.032) and lipemia interferences (P = 0.010), proper choice of anticoagulants (P = 0.001), transport conditions for ammonia sample (P < 0.001) and order of draw during blood specimen collection (P < 0.001), in comparison with students from SM and FVM. Students from FPB are more conscious of the importance of preanalytical phase of testing in comparison with their colleagues from other biomedical faculties. No difference in knowledge between penultimate and final year of the same faculty was found.
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A Systematic Evaluation of Blood Serum and Plasma Pre-Analytics for Metabolomics Cohort Studies
Jobard, Elodie; Trédan, Olivier; Postoly, Déborah; André, Fabrice; Martin, Anne-Laure; Elena-Herrmann, Bénédicte; Boyault, Sandrine
2016-01-01
The recent thriving development of biobanks and associated high-throughput phenotyping studies requires the elaboration of large-scale approaches for monitoring biological sample quality and compliance with standard protocols. We present a metabolomic investigation of human blood samples that delineates pitfalls and guidelines for the collection, storage and handling procedures for serum and plasma. A series of eight pre-processing technical parameters is systematically investigated along variable ranges commonly encountered across clinical studies. While metabolic fingerprints, as assessed by nuclear magnetic resonance, are not significantly affected by altered centrifugation parameters or delays between sample pre-processing (blood centrifugation) and storage, our metabolomic investigation highlights that both the delay and storage temperature between blood draw and centrifugation are the primary parameters impacting serum and plasma metabolic profiles. Storing the blood drawn at 4 °C is shown to be a reliable routine to confine variability associated with idle time prior to sample pre-processing. Based on their fine sensitivity to pre-analytical parameters and protocol variations, metabolic fingerprints could be exploited as valuable ways to determine compliance with standard procedures and quality assessment of blood samples within large multi-omic clinical and translational cohort studies. PMID:27929400
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Mechanic, Leah; Mendez, Armando; Merrill, Lori; Rogers, John; Layton, Marnie; Todd, Deborah; Varanasi, Arti; O’Brien, Barbara; Meyer, William A.; Zhang, Ming; Schleicher, Rosemary L.; Moye, Jack
2014-01-01
BACKGROUND Preanalytical conditions encountered during collection, processing, and storage of biospecimens may influence laboratory results. The National Children’s Study (NCS) is a planned prospective cohort study of 100,000 families to examine the influence of a wide variety of exposures on child health. In developing biospecimen collection, processing, and storage procedures for the NCS, we identified several analytes of different biochemical categories for which it was unclear to what extent deviations from NCS procedures could influence measurement results. METHODS A pilot study was performed to examine effects of preanalytic sample handling conditions (delays in centrifugation, freezing delays, delays in separation from cells, additive delay, and tube type) on concentrations of eight different analytes. 2,825 measurements were made to assess 15 unique combinations of analyte and handling conditions in blood collected from 151 women of childbearing age (≥20 individuals per handling condition). RESULTS The majority of analytes were stable under the conditions evaluated. However, levels of plasma interleukin-6 and serum insulin were decreased in response to sample centrifugation delays of up to 5.5 hours post collection (P<0.0001). In addition, delays in freezing centrifuged plasma samples (comparing 24, 48 and 72 hours to immediate freezing) resulted in increased levels of adrenocorticotropic hormone (P=0.0014). CONCLUSIONS Determining stability of proposed analytes in response to preanalytical conditions and handling helps to ensure high-quality specimens for study now and in the future. The results inform development of procedures, plans for measurement of analytes, and interpretation of laboratory results. PMID:23924524
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Pichler, Martin; Zatloukal, Kurt
2013-01-01
Analysis of RNA isolated from fixed and paraffin-embedded tissues is widely used in biomedical research and molecular pathological diagnostics. We have performed a comprehensive and systematic investigation of the impact of factors in the pre-analytical workflow, such as different fixatives, fixation time, RNA extraction method and storage of tissues in paraffin blocks, on several downstream reactions including complementary DNA (cDNA) synthesis, quantitative reverse transcription polymerase chain reaction (qRT-PCR) and microarray hybridization. We compared the effects of routine formalin fixation with the non-crosslinking, alcohol-based Tissue Tek Xpress Molecular Fixative (TTXMF, Sakura Finetek), and cryopreservation as gold standard for molecular analyses. Formalin fixation introduced major changes into microarray gene expression data and led to marked gene-to-gene variations in delta-ct values of qRT-PCR. We found that qRT-PCR efficiency and gene-to-gene variations were mainly attributed to differences in the efficiency of cDNA synthesis as the most sensitive step. These differences could not be reliably detected by quality assessment of total RNA isolated from formalin-fixed tissues by electrophoresis or spectrophotometry. Although RNA from TTXMF fixed samples was as fragmented as RNA from formalin fixed samples, much higher cDNA yield and lower ct-values were obtained in qRT-PCR underlining the negative impact of crosslinking by formalin. In order to better estimate the impact of pre-analytical procedures such as fixation on the reliability of downstream analysis, we applied a qRT-PCR-based assay using amplicons of different length and an assay measuring the efficiency of cDNA generation. Together these two assays allowed better quality assessment of RNA extracted from fixed and paraffin-embedded tissues and should be used to supplement quality scores derived from automated electrophoresis. A better standardization of the pre-analytical workflow, application of additional quality controls and detailed sample information would markedly improve the comparability and reliability of molecular studies based on formalin-fixed and paraffin-embedded tissue samples. PMID:23936242
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Bogdanovska-Todorovska, Magdalena; Petrushevska, Gordana; Janevska, Vesna; Spasevska, Liljana; Kostadinova-Kunovska, Slavica
2018-05-20
Accurate assessment of human epidermal growth factor receptor 2 (HER-2) is crucial in selecting patients for targeted therapy. Commonly used methods for HER-2 testing are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Here we presented the implementation, optimization and standardization of two FISH protocols using breast cancer samples and assessed the impact of pre-analytical and analytical factors on HER-2 testing. Formalin fixed paraffin embedded (FFPE) tissue samples from 70 breast cancer patients were tested for HER-2 using PathVysion™ HER-2 DNA Probe Kit and two different paraffin pretreatment kits, Vysis/Abbott Paraffin Pretreatment Reagent Kit (40 samples) and DAKO Histology FISH Accessory Kit (30 samples). The concordance between FISH and IHC results was determined. Pre-analytical and analytical factors (i.e., fixation, baking, digestion, and post-hybridization washing) affected the efficiency and quality of hybridization. The overall hybridization success in our study was 98.6% (69/70); the failure rate was 1.4%. The DAKO pretreatment kit was more time-efficient and resulted in more uniform signals that were easier to interpret, compared to the Vysis/Abbott kit. The overall concordance between IHC and FISH was 84.06%, kappa coefficient 0.5976 (p < 0.0001). The greatest discordance (82%) between IHC and FISH was observed in IHC 2+ group. A standardized FISH protocol for HER-2 assessment, with high hybridization efficiency, is necessary due to variability in tissue processing and individual tissue characteristics. Differences in the pre-analytical and analytical steps can affect the hybridization quality and efficiency. The use of DAKO pretreatment kit is time-saving and cost-effective.
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Dukic, Lora; Jokic, Anja; Kules, Josipa; Pasalic, Daria
2016-01-01
Introduction The educational program for health care personnel is important for reducing preanalytical errors and improving quality of laboratory test results. The aim of our study was to assess the level of knowledge on preanalytical phase in population of biomedicine students through a cross-sectional survey. Materials and methods A survey was sent to students on penultimate and final year of Faculty of Pharmacy and Biochemistry – study of medical biochemistry (FPB), Faculty of Veterinary Medicine (FVM) and School of Medicine (SM), University of Zagreb, Croatia, using the web tool SurveyMonkey. Survey was composed of demographics and 14 statements regarding the preanalytical phase of laboratory testing. Comparison of frequencies and proportions of correct answers was done with Fisher’s exact test and test of comparison of proportions, respectively. Results Study included 135 participants, median age 24 (23-40) years. Students from FPB had higher proportion of correct answers (86%) compared to students from other biomedical faculties 62%, P < 0.001. Students from FPB were more conscious of the importance of specimen mixing (P = 0.027), prevalence of preanalytical errors (P = 0.001), impact of hemolysis (P = 0.032) and lipemia interferences (P = 0.010), proper choice of anticoagulants (P = 0.001), transport conditions for ammonia sample (P < 0.001) and order of draw during blood specimen collection (P < 0.001), in comparison with students from SM and FVM. Conclusions Students from FPB are more conscious of the importance of preanalytical phase of testing in comparison with their colleagues from other biomedical faculties. No difference in knowledge between penultimate and final year of the same faculty was found. PMID:26981023
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Metabolic profiling of body fluids and multivariate data analysis.
Trezzi, Jean-Pierre; Jäger, Christian; Galozzi, Sara; Barkovits, Katalin; Marcus, Katrin; Mollenhauer, Brit; Hiller, Karsten
2017-01-01
Metabolome analyses of body fluids are challenging due pre-analytical variations, such as pre-processing delay and temperature, and constant dynamical changes of biochemical processes within the samples. Therefore, proper sample handling starting from the time of collection up to the analysis is crucial to obtain high quality samples and reproducible results. A metabolomics analysis is divided into 4 main steps: 1) Sample collection, 2) Metabolite extraction, 3) Data acquisition and 4) Data analysis. Here, we describe a protocol for gas chromatography coupled to mass spectrometry (GC-MS) based metabolic analysis for biological matrices, especially body fluids. This protocol can be applied on blood serum/plasma, saliva and cerebrospinal fluid (CSF) samples of humans and other vertebrates. It covers sample collection, sample pre-processing, metabolite extraction, GC-MS measurement and guidelines for the subsequent data analysis. Advantages of this protocol include: •Robust and reproducible metabolomics results, taking into account pre-analytical variations that may occur during the sampling process•Small sample volume required•Rapid and cost-effective processing of biological samples•Logistic regression based determination of biomarker signatures for in-depth data analysis.
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Improving preanalytic processes using the principles of lean production (Toyota Production System).
Persoon, Thomas J; Zaleski, Sue; Frerichs, Janice
2006-01-01
The basic technologies used in preanalytic processes for chemistry tests have been mature for a long time, and improvements in preanalytic processes have lagged behind improvements in analytic and postanalytic processes. We describe our successful efforts to improve chemistry test turnaround time from a central laboratory by improving preanalytic processes, using existing resources and the principles of lean production. Our goal is to report 80% of chemistry tests in less than 1 hour and to no longer recognize a distinction between expedited and routine testing. We used principles of lean production (the Toyota Production System) to redesign preanalytic processes. The redesigned preanalytic process has fewer steps and uses 1-piece flow to move blood samples through the accessioning, centrifugation, and aliquoting processes. Median preanalytic processing time was reduced from 29 to 19 minutes, and the laboratory met the goal of reporting 80% of chemistry results in less than 1 hour for 11 consecutive months.
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Nielsen, Marie Katrine Klose; Johansen, Sys Stybe; Linnet, Kristian
2014-01-01
Assessment of total uncertainty of analytical methods for the measurements of drugs in human hair has mainly been derived from the analytical variation. However, in hair analysis several other sources of uncertainty will contribute to the total uncertainty. Particularly, in segmental hair analysis pre-analytical variations associated with the sampling and segmentation may be significant factors in the assessment of the total uncertainty budget. The aim of this study was to develop and validate a method for the analysis of 31 common drugs in hair using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) with focus on the assessment of both the analytical and pre-analytical sampling variations. The validated method was specific, accurate (80-120%), and precise (CV≤20%) across a wide linear concentration range from 0.025-25 ng/mg for most compounds. The analytical variation was estimated to be less than 15% for almost all compounds. The method was successfully applied to 25 segmented hair specimens from deceased drug addicts showing a broad pattern of poly-drug use. The pre-analytical sampling variation was estimated from the genuine duplicate measurements of two bundles of hair collected from each subject after subtraction of the analytical component. For the most frequently detected analytes, the pre-analytical variation was estimated to be 26-69%. Thus, the pre-analytical variation was 3-7 folds larger than the analytical variation (7-13%) and hence the dominant component in the total variation (29-70%). The present study demonstrated the importance of including the pre-analytical variation in the assessment of the total uncertainty budget and in the setting of the 95%-uncertainty interval (±2CVT). Excluding the pre-analytical sampling variation could significantly affect the interpretation of results from segmental hair analysis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
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Szulc, P; Naylor, K; Hoyle, N R; Eastell, R; Leary, E T
2017-09-01
The National Bone Health Alliance (NBHA) recommends standardized sample handling and patient preparation for C-terminal telopeptide of type I collagen (CTX-I) and N-terminal propeptide of type I procollagen (PINP) measurements to reduce pre-analytical variability. Controllable and uncontrollable patient-related factors are reviewed to facilitate interpretation and minimize pre-analytical variability. The IOF and the International Federation of Clinical Chemistry (IFCC) Bone Marker Standards Working Group have identified PINP and CTX-I in blood to be the reference markers of bone turnover for the fracture risk prediction and monitoring of osteoporosis treatment. Although used in clinical research for many years, bone turnover markers (BTM) have not been widely adopted in clinical practice primarily due to their poor within-subject and between-lab reproducibility. The NBHA Bone Turnover Marker Project team aim to reduce pre-analytical variability of CTX-I and PINP measurements through standardized sample handling and patient preparation. Recommendations for sample handling and patient preparations were made based on review of available publications and pragmatic considerations to reduce pre-analytical variability. Controllable and un-controllable patient-related factors were reviewed to facilitate interpretation and sample collection. Samples for CTX-I must be collected consistently in the morning hours in the fasted state. EDTA plasma is preferred for CTX-I for its greater sample stability. Sample collection conditions for PINP are less critical as PINP has minimal circadian variability and is not affected by food intake. Sample stability limits should be observed. The uncontrollable aspects (age, sex, pregnancy, immobility, recent fracture, co-morbidities, anti-osteoporotic drugs, other medications) should be considered in BTM interpretation. Adopting standardized sample handling and patient preparation procedures will significantly reduce controllable pre-analytical variability. The successful adoption of such recommendations necessitates the close collaboration of various stakeholders at the global stage, including the laboratories, the medical community, the reagent manufacturers and the regulatory agencies.
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Piva, Elisa; Tosato, Francesca; Plebani, Mario
2015-12-07
Most errors in laboratory medicine occur in the pre-analytical phase of the total testing process. Phlebotomy, a crucial step in the pre-analytical phase influencing laboratory results and patient outcome, calls for quality assurance procedures and automation in order to prevent errors and ensure patient safety. We compared the performance of a new small, automated device, the ProTube Inpeco, designed for use in phlebotomy with a complete traceability of the process, with a centralized automated system, BC ROBO. ProTube was used for 15,010 patients undergoing phlebotomy with 48,776 tubes being labeled. The mean time and standard deviation (SD) for blood sampling was 3:03 (min:sec; SD ± 1:24) when using ProTube, against 5:40 (min:sec; SD ± 1:57) when using BC ROBO. The mean number of patients per hour managed at each phlebotomy point was 16 ± 3 with ProTube, and 10 ± 2 with BC ROBO. No tubes were labeled erroneously or incorrectly, even if process failure occurred in 2.8% of cases when ProTube was used. Thanks to its cutting edge technology, the ProTube has many advantages over BC ROBO, above all in verifying patient identity, and in allowing a reduction in both identification error and tube mislabeling.
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Arreaza, Gladys; Qiu, Ping; Pang, Ling; Albright, Andrew; Hong, Lewis Z.; Marton, Matthew J.; Levitan, Diane
2016-01-01
In cancer drug discovery, it is important to investigate the genetic determinants of response or resistance to cancer therapy as well as factors that contribute to adverse events in the course of clinical trials. Despite the emergence of new technologies and the ability to measure more diverse analytes (e.g., circulating tumor cell (CTC), circulating tumor DNA (ctDNA), etc.), tumor tissue is still the most common and reliable source for biomarker investigation. Because of its worldwide use and ability to preserve samples for many decades at ambient temperature, formalin-fixed, paraffin-embedded tumor tissue (FFPE) is likely to be the preferred choice for tissue preservation in clinical practice for the foreseeable future. Multiple analyses are routinely performed on the same FFPE samples (such as Immunohistochemistry (IHC), in situ hybridization, RNAseq, DNAseq, TILseq, Methyl-Seq, etc.). Thus, specimen prioritization and optimization of the isolation of analytes is critical to ensure successful completion of each assay. FFPE is notorious for producing suboptimal DNA quality and low DNA yield. However, commercial vendors tend to request higher DNA sample mass than what is actually required for downstream assays, which restricts the breadth of biomarker work that can be performed. We evaluated multiple genomics service laboratories to assess the current state of NGS pre-analytical processing of FFPE. Significant differences in pre-analytical capabilities were observed. Key aspects are highlighted and recommendations are made to improve the current practice in translational research. PMID:27657050
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Lippi, Giuseppe; Ippolito, Luigi; Favaloro, Emmanuel J
2013-10-01
Automation in hemostasis testing is entering an exciting and unprecedented phase. This study was planned to assess the performance of the new preanalytical module on the hemostasis testing system Instrumentation Laboratory ACL TOP. The evaluation included interference studies to define reliable thresholds for rejecting samples with significant concentrations of interfering substances; within-run imprecision studies of plasma indices on four different interference degrees for each index; comparison studies with reference measures of hemolysis index, bilirubin, and triglycerides on clinical chemistry analyzers; and calculation of turnaround time with and without automatic performance of preanalytical check. The upper limits for sample rejection according to our interference studies were 3.6 g/L for hemoglobin, 13.6 mg/dL for bilirubin, and 1454 mg/dL for triglycerides. We found optimal precision for all indices (0.6% to 3.1% at clinically relevant thresholds) and highly significant correlations with reference measures on clinical chemistry analyzers (from 0.985 to 0.998). The limited increase of turnaround time (i.e., +3% and +5% with or without cap-piercing), coupled with no adjunctive costs over performance of normal coagulation assays, contribute to make the automatic check of plasma indices on ACL TOP a reliable and practical approach for improving testing quality and safeguarding patient safety.
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Chen, Hui; Luthra, Rajyalakshmi; Goswami, Rashmi S; Singh, Rajesh R; Roy-Chowdhuri, Sinchita
2015-08-28
Application of next-generation sequencing (NGS) technology to routine clinical practice has enabled characterization of personalized cancer genomes to identify patients likely to have a response to targeted therapy. The proper selection of tumor sample for downstream NGS based mutational analysis is critical to generate accurate results and to guide therapeutic intervention. However, multiple pre-analytic factors come into play in determining the success of NGS testing. In this review, we discuss pre-analytic requirements for AmpliSeq PCR-based sequencing using Ion Torrent Personal Genome Machine (PGM) (Life Technologies), a NGS sequencing platform that is often used by clinical laboratories for sequencing solid tumors because of its low input DNA requirement from formalin fixed and paraffin embedded tissue. The success of NGS mutational analysis is affected not only by the input DNA quantity but also by several other factors, including the specimen type, the DNA quality, and the tumor cellularity. Here, we review tissue requirements for solid tumor NGS based mutational analysis, including procedure types, tissue types, tumor volume and fraction, decalcification, and treatment effects.
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NASA Astrophysics Data System (ADS)
Cucu, Daniela; Woods, Mike
2008-08-01
The paper aims to present a practical approach for testing laboratories to ensure the quality of their test results. It is based on the experience gained in assessing a large number of testing laboratories, discussing with management and staff, reviewing results obtained in national and international PTs and ILCs and exchanging information in the EA laboratory committee. According to EN ISO/IEC 17025, an accredited laboratory has to implement a programme to ensure the quality of its test results for each measurand. Pre-analytical, analytical and post-analytical measures shall be applied in a systematic manner. They shall include both quality control and quality assurance measures. When designing the quality assurance programme a laboratory should consider pre-analytical activities (like personnel training, selection and validation of test methods, qualifying equipment), analytical activities ranging from sampling, sample preparation, instrumental analysis and post-analytical activities (like decoding, calculation, use of statistical tests or packages, management of results). Designed on different levels (analyst, quality manager and technical manager), including a variety of measures, the programme shall ensure the validity and accuracy of test results, the adequacy of the management system, prove the laboratory's competence in performing tests under accreditation and last but not least show the comparability of test results. Laboratory management should establish performance targets and review periodically QC/QA results against them, implementing appropriate measures in case of non-compliance.
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A Call to Standardize Preanalytic Data Elements for Biospecimens, Part II.
Robb, James A; Bry, Lynn; Sluss, Patrick M; Wagar, Elizabeth A; Kennedy, Mary F
2015-09-01
Biospecimens must have appropriate clinical annotation (data) to ensure optimal quality for both patient care and research. Additional clinical preanalytic variables are the focus of this continuing study. To complete the identification of the essential preanalytic variables (data fields) that can, and in some instances should, be attached to every collected biospecimen by adding the additional specific variables for clinical chemistry and microbiology to our original 170 variables. The College of American Pathologists Diagnostic Intelligence and Health Information Technology Committee sponsored a second Biorepository Working Group to complete the list of preanalytic variables for annotating biospecimens. Members of the second Biorepository Working Group are experts in clinical pathology and microbiology. Additional preanalytic area-specific variables were identified and ranked along with definitions and potential negative impacts if the variable is not attached to the biospecimen. The draft manuscript was reviewed by additional national and international stakeholders. Four additional required preanalytic variables were identified specifically for clinical chemistry and microbiology biospecimens that can be used as a guide for site-specific implementation into patient care and research biorepository processes. In our collective experience, selecting which of the many preanalytic variables to attach to any specific set of biospecimens used for patient care and/or research is often difficult. The additional ranked list should be of practical benefit when selecting preanalytic variables for a given biospecimen collection.
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Pizarro, Consuelo; Arenzana-Rámila, Irene; Pérez-del-Notario, Nuria; Pérez-Matute, Patricia; González-Sáiz, José María
2016-03-17
Lipid profiling is a promising tool for the discovery and subsequent identification of biomarkers associated with various diseases. However, data quality is quite dependent on the pre-analytical methods employed. To date, potential confounding factors that may affect lipid metabolite levels after the thawing of plasma for biomarker exploration studies have not been thoroughly evaluated. In this study, by means of experimental design methodology, we performed the first in-depth examination of the ways in which thawing conditions affect lipid metabolite levels. After the optimization stage, we concluded that temperature, sample volume and the thawing method were the determining factors that had to be exhaustively controlled in the thawing process to ensure the quality of biomarker discovery. Best thawing conditions were found to be: 4 °C, with 0.25 mL of human plasma and ultrasound (US) thawing. The new US proposed thawing method was quicker than the other methods we studied, allowed more features to be identified and increased the signal of the lipids. In view of its speed, efficiency and detectability, the US thawing method appears to be a simple, economical method for the thawing of plasma samples, which could easily be applied in clinical laboratories before lipid profiling studies. Copyright © 2016 Elsevier B.V. All rights reserved.
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A call to standardize preanalytic data elements for biospecimens.
Robb, James A; Gulley, Margaret L; Fitzgibbons, Patrick L; Kennedy, Mary F; Cosentino, L Mark; Washington, Kay; Dash, Rajesh C; Branton, Philip A; Jewell, Scott D; Lapham, Rosanna L
2014-04-01
Biospecimens must have appropriate clinical annotation (data) to ensure optimal quality for both patient care and research. Clinical preanalytic variables are the focus of this study. To define the essential preanalytic variables (data fields) that should be attached to every collected biospecimen and to provide a complete list of such variables, along with their relative importance, which can vary, depending on downstream use, institutional needs, and information technology capabilities. The College of American Pathologists Diagnostic Intelligence and Health Information Technology Committee sponsored a Biorepository Working Group to develop a ranked list of the preanalytic variables for annotating biospecimens. Members of the working group were experts in anatomic, clinical, and molecular pathology; biobanking; medical informatics; and accreditation. Several members had experience with federal government programs, such as the National Cancer Institute's Biospecimens and Biorepository Branch and the National Cancer Institute's Community Cancer Center Program. Potential preanalytic variables were identified and ranked along with available supporting evidence, definitions, and potential negative effects if the variable was not attached to the biospecimen. Additional national and international stakeholders reviewed the draft manuscript. The ranked listing of 170 preanalytic variables produced can be used as a guide for site-specific implementation into patient care and/or research biorepository processes. Conclusions.-In our collective experience, it is often difficult to choose which of the many preanalytic variables to attach to any specific set of biospecimens used for patient care and/or research. The provided ranked list should aid in the selection of preanalytic variables for a given biospecimen collection.
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Parés-Pollán, L; Gonzalez-Quintana, A; Docampo-Cordeiro, J; Vargas-Gallego, C; García-Álvarez, G; Ramos-Rodríguez, V; Diaz Rubio-García, M P
2014-01-01
Owing to the decrease in values of biochemical glucose parameter in some samples from external extraction centres, and the risk this implies to patient safety; it was decided to apply an adaptation of the «Health Services Failure Mode and Effects Analysis» (HFMEA) to manage risk during the pre-analytical phase of sample transportation from external centres to clinical laboratories. A retrospective study of glucose parameter was conducted during two consecutive months. The analysis was performed in its different phases: to define the HFMEA topic, assemble the team, graphically describe the process, conduct a hazard analysis, design the intervention and indicators, and identify a person to be responsible for ensuring completion of each action. The results of glucose parameter in one of the transport routes, were significantly lower (P=.006). The errors and potential causes of this problem were analysed, and criteria of criticality and detectability were applied (score≥8) in the decision tree. It was decided to: develop a document management system; reorganise extractions and transport routes in some centres; quality control of the sample container ice-packs, and the time and temperature during transportation. This work proposes quality indicators for controlling time and temperature of transported samples in the pre-analytical phase. Periodic review of certain laboratory parameters can help to detect problems in transporting samples. The HFMEA technique is useful for the clinical laboratory. Copyright © 2013 SECA. Published by Elsevier Espana. All rights reserved.
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Lermen, Dominik; Schmitt, Daniel; Bartel-Steinbach, Martina; Schröter-Kermani, Christa; Kolossa-Gehring, Marike; von Briesen, Hagen; Zimmermann, Heiko
2014-01-01
Technical progress has simplified tasks in lab diagnosis and improved quality of test results. Errors occurring during the pre-analytical phase have more negative impact on the quality of test results than errors encountered during the total analytical process. Different infrastructures of sampling sites can highly influence the quality of samples and therewith of analytical results. Annually the German Environmental Specimen Bank (ESB) collects, characterizes, and stores blood, plasma, and urine samples of 120–150 volunteers each on four different sampling sites in Germany. Overarching goal is to investigate the exposure to environmental pollutants of non-occupational exposed young adults combining human biomonitoring with questionnaire data. We investigated the requirements of the study and the possibility to realize a highly standardized sampling procedure on a mobile platform in order to increase the required quality of the pre-analytical phase. The results lead to the development of a mobile epidemiologic laboratory (epiLab) in the project “Labor der Zukunft” (future’s lab technology). This laboratory includes a 14.7 m2 reception area to record medical history and exposure-relevant behavior, a 21.1 m2 examination room to record dental fillings and for blood withdrawal, a 15.5 m2 biological safety level 2 laboratory to process and analyze samples on site including a 2.8 m2 personnel lock and a 3.6 m2 cryofacility to immediately freeze samples. Frozen samples can be transferred to their final destination within the vehicle without breaking the cold chain. To our knowledge, we herewith describe for the first time the implementation of a biological safety laboratory (BSL) 2 lab and an epidemiologic unit on a single mobile platform. Since 2013 we have been collecting up to 15.000 individual human samples annually under highly standardized conditions using the mobile laboratory. Characterized and free of alterations they are kept ready for retrospective analyses in their final archive, the German ESB. PMID:25141120
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Lermen, Dominik; Schmitt, Daniel; Bartel-Steinbach, Martina; Schröter-Kermani, Christa; Kolossa-Gehring, Marike; von Briesen, Hagen; Zimmermann, Heiko
2014-01-01
Technical progress has simplified tasks in lab diagnosis and improved quality of test results. Errors occurring during the pre-analytical phase have more negative impact on the quality of test results than errors encountered during the total analytical process. Different infrastructures of sampling sites can highly influence the quality of samples and therewith of analytical results. Annually the German Environmental Specimen Bank (ESB) collects, characterizes, and stores blood, plasma, and urine samples of 120-150 volunteers each on four different sampling sites in Germany. Overarching goal is to investigate the exposure to environmental pollutants of non-occupational exposed young adults combining human biomonitoring with questionnaire data. We investigated the requirements of the study and the possibility to realize a highly standardized sampling procedure on a mobile platform in order to increase the required quality of the pre-analytical phase. The results lead to the development of a mobile epidemiologic laboratory (epiLab) in the project "Labor der Zukunft" (future's lab technology). This laboratory includes a 14.7 m(2) reception area to record medical history and exposure-relevant behavior, a 21.1 m(2) examination room to record dental fillings and for blood withdrawal, a 15.5 m(2) biological safety level 2 laboratory to process and analyze samples on site including a 2.8 m(2) personnel lock and a 3.6 m2 cryofacility to immediately freeze samples. Frozen samples can be transferred to their final destination within the vehicle without breaking the cold chain. To our knowledge, we herewith describe for the first time the implementation of a biological safety laboratory (BSL) 2 lab and an epidemiologic unit on a single mobile platform. Since 2013 we have been collecting up to 15.000 individual human samples annually under highly standardized conditions using the mobile laboratory. Characterized and free of alterations they are kept ready for retrospective analyses in their final archive, the German ESB.
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Ishibashi, Midori
2015-01-01
The cost, speed, and quality are the three important factors recently indicated by the Ministry of Health, Labour and Welfare (MHLW) for the purpose of accelerating clinical studies. Based on this background, the importance of laboratory tests is increasing, especially in the evaluation of clinical study participants' entry and safety, and drug efficacy. To assure the quality of laboratory tests, providing high-quality laboratory tests is mandatory. For providing adequate quality assurance in laboratory tests, quality control in the three fields of pre-analytical, analytical, and post-analytical processes is extremely important. There are, however, no detailed written requirements concerning specimen collection, handling, preparation, storage, and shipping. Most laboratory tests for clinical studies are performed onsite in a local laboratory; however, a part of laboratory tests is done in offsite central laboratories after specimen shipping. As factors affecting laboratory tests, individual and inter-individual variations are well-known. Besides these factors, standardizing the factors of specimen collection, handling, preparation, storage, and shipping, may improve and maintain the high quality of clinical studies in general. Furthermore, the analytical method, units, and reference interval are also important factors. It is concluded that, to overcome the problems derived from pre-analytical processes, it is necessary to standardize specimen handling in a broad sense.
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Doggui, Radhouene; El Ati-Hellal, Myriam; Traissac, Pierre; El Ati, Jalila
2018-03-26
Urinary iodine concentration (UIC) is commonly used to assess iodine status of subjects in epidemiological surveys. As pre-analytical factors are an important source of measurement error and studies about this phase are scarce, our objective was to assess the influence of urine sampling conditions on UIC, i.e., whether the child ate breakfast or not, urine void rank of the day, and time span between last meal and urine collection. A nationwide, two-stage, stratified, cross-sectional study including 1560 children (6-12 years) was performed in 2012. UIC was determined by the Sandell-Kolthoff method. Pre-analytical factors were assessed from children's mothers by using a questionnaire. Association between iodine status and pre-analytical factors were adjusted for one another and socio-economic characteristics by multivariate linear and multinomial regression models (RPR: relative prevalence ratios). Skipping breakfast prior to morning urine sampling decreased UIC by 40 to 50 μg/L and the proportion of UIC < 100 μg/L was higher among children having those skipped breakfast (RPR = 3.2[1.0-10.4]). In unadjusted analyses, UIC was less among children sampled more than 5 h from their last meal. UIC decreased with rank of urine void (e.g., first vs. second, P < 0.001); also, the proportion of UIC < 100 μg/L was greater among 4th rank samples (vs. second RPR = 2.1[1.1-4.0]). Subjects' breakfast status and urine void rank should be accounted for when assessing iodine status. Providing recommendations to standardize pre-analytical factors is a key step toward improving accuracy and comparability of survey results for assessing iodine status from spot urine samples. These recommendations have to be evaluated by future research.
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Lombardi, Giovanni; Barbaro, Mosè; Locatelli, Massimo; Banfi, Giuseppe
2017-06-01
The endocrine function of bone is now a recognized feature of this tissue. Bone-derived hormones that modulate whole-body homeostasis, are being discovered as for the effects on bone of novel and classic hormones produced by other tissues become known. Often, however, the data regarding these last generation bone-derived or bone-targeting hormones do not give about a clear picture of their physiological roles or concentration ranges. A certain degree of uncertainty could stem from differences in the pre-analytical management of biological samples. The pre-analytical phase comprises a series of decisions and actions (i.e., choice of sample matrix, methods of collection, transportation, treatment and storage) preceding analysis. Errors arising in this phase will inevitably be carried over to the analytical phase where they can reduce the measurement accuracy, ultimately, leading discrepant results. While the pre-analytical phase is all important, in routine laboratory medicine, it is often not given due consideration in research and clinical trials. This is particularly true for novel molecules, such as the hormones regulating the endocrine function of bone. In this review we discuss the importance of the pre-analytical variables affecting the measurement of last generation bone-associated hormones and describe their, often debated and rarely clear physiological roles.
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da Cunha Santos, G; Saieg, M A; Troncone, G; Zeppa, P
2018-04-01
Minimally invasive procedures such as endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) must yield not only good quality and quantity of material for morphological assessment, but also an adequate sample for analysis of molecular markers to guide patients to appropriate targeted therapies. In this context, cytopathologists worldwide should be familiar with minimum requirements for refereeing cytological samples for testing. The present manuscript is a review with comprehensive description of the content of the workshop entitled Cytological preparations for molecular analysis: pre-analytical issues for EBUS TBNA, presented at the 40th European Congress of Cytopathology in Liverpool, UK. The present review emphasises the advantages and limitations of different types of cytology substrates used for molecular analysis such as archival smears, liquid-based preparations, archival cytospin preparations and FTA (Flinders Technology Associates) cards, as well as their technical requirements/features. These various types of cytological specimens can be successfully used for an extensive array of molecular studies, but the quality and quantity of extracted nucleic acids rely directly on adequate pre-analytical assessment of those samples. In this setting, cytopathologists must not only be familiar with the different types of specimens and associated technical procedures, but also correctly handle the material provided by minimally invasive procedures, ensuring that there is sufficient amount of material for a precise diagnosis and correct management of the patient through personalised care. © 2018 John Wiley & Sons Ltd.
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Kieninger, M; Zech, N; Mulzer, Y; Bele, S; Seemann, M; Künzig, H; Schneiker, A; Gruber, M
2015-05-01
Point of care testing with blood gas analysis (BGA) is an important factor for intensive care medicine. Continuous efforts to optimize workflow, improve safety for the staff and avoid preanalytical mistakes are important and should reflect quality management standards. In a prospective observational study it was investigated whether the implementation of a new system for BGA using labeled syringes and automated processing of the specimens leads to improvements compared to the previously used procedure. In a 4-week test period the time until receiving the final results of the BGA with the standard method used in the clinical routine (control group) was compared to the results in a second 4-week test period using the new labeled syringes and automated processing of the specimens (intervention group). In addition, preanalytical mistakes with both systems were checked during routine daily use. Finally, it was investigated whether a delay of 10 min between taking and analyzing the blood samples alters the results of the BGA. Preanalytical errors were frequently observed in the control group where non-deaerated samples were recorded in 87.3 % but in the intervention group almost all samples (98.9 %) were correctly deaerated. Insufficient homogenization due to omission of manual pivoting was seen in 83.2 % in the control group and in 89.9 % in the intervention group; however, in the intervention group the samples were homogenized automatically during the further analytical process. Although a survey among the staff revealed a high acceptance of the new system and a subjective improvement of workflow, a measurable gain in time after conversion to the new procedure could not be seen. The mean time needed for a complete analysis process until receiving the final results was 244 s in the intervention group and 201 s in the control group. A 10-min delay between taking and analyzing the blood samples led to a significant and clinically relevant elevation of the values for partial pressure of oxygen (pO2) in both groups compared to the results when analyzing the samples immediately (118.4 vs. 148.6 mmHg in the control group and 115.3 vs. 123.7 mmHg in the intervention group). When using standard syringes the partial pressure of carbon dioxide (pCO2) was significantly lower (40.5 vs. 38.3 mmHg) whereas no alterations were seen when using the labeled syringes. The implementation of a new BGA system with labeled syringes and automated processing of the specimens was possible without any difficulties under daily clinical routine conditions in this 10-bed intensive care unit (ICU). A gain of time could not be measured but a reduction in preanalytical errors using the labeled syringes with automated processing was found. Delayed analysis of blood samples can lead to significant changes in pO2 and pCO2 depending on the type of syringe used.
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Zhao, Shuzhen; He, Lujia; Feng, Chenchen; He, Xiaoli
2018-06-01
Laboratory errors in blood collection center (BCC) are most common in the preanalytical phase. It is, therefore, of vital importance for administrators to take measures to improve healthcare quality and patient safety.In 2015, a case bundle management strategy was applied in a large outpatient BCC to improve its medical quality and patient safety.Unqualified blood sampling, complications, patient waiting time, largest number of patients waiting during peak hours, patient complaints, and patient satisfaction were compared over the period from 2014 to 2016.The strategy reduced unqualified blood sampling, complications, patient waiting time, largest number of patients waiting during peak hours, and patient complaints, while improving patient satisfaction.This strategy was effective in improving BCC healthcare quality and patient safety.
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Johns, Jennifer L.; Moorhead, Kaitlin A.; Hu, Jing; Moorhead, Roberta C.
2018-01-01
Clinical pathology testing of rodents is often challenging due to insufficient sample volume. One solution in clinical veterinary and exploratory research environments is dilution of samples prior to analysis. However, published information on the impact of preanalytical sample dilution on rodent biochemical data is incomplete. The objective of this study was to evaluate the effects of preanalytical sample dilution on biochemical analysis of mouse and rat serum samples utilizing the Siemens Dimension Xpand Plus. Rats were obtained from end of study research projects. Mice were obtained from sentinel testing programs. For both, whole blood was collected via terminal cardiocentesis into empty tubes and serum was harvested. Biochemical parameters were measured on fresh and thawed frozen samples run straight and at dilution factors 2–10. Dilutions were performed manually, utilizing either ultrapure water or enzyme diluent per manufacturer recommendations. All diluted samples were generated directly from the undiluted sample. Preanalytical dilution caused clinically unacceptable bias in most analytes at dilution factors four and above. Dilution-induced bias in total calcium, creatinine, total bilirubin, and uric acid was considered unacceptable with any degree of dilution, based on the more conservative of two definitions of acceptability. Dilution often caused electrolyte values to fall below assay range precluding evaluation of bias. Dilution-induced bias occurred in most biochemical parameters to varying degrees and may render dilution unacceptable in the exploratory research and clinical veterinary environments. Additionally, differences between results obtained at different dilution factors may confound statistical comparisons in research settings. Comparison of data obtained at a single dilution factor is highly recommended. PMID:29497614
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Lippi, Giuseppe; Montagnana, Martina; Giavarina, Davide
2006-01-01
Owing to remarkable advances in automation, laboratory technology and informatics, the pre-analytical phase has become the major source of variability in laboratory testing. The present survey investigated the development of several pre-analytical processes within a representative cohort of Italian clinical laboratories. A seven-point questionnaire was designed to investigate the following issues: 1a) the mean outpatient waiting time before check-in and 1b) the mean time from check-in to sample collection; 2) the mean time from sample collection to analysis; 3) the type of specimen collected for clinical chemistry testing; 4) the degree of pre-analytical automation; 5a) the number of samples shipped to other laboratories and 5b) the availability of standardised protocols for transportation; 6) the conditions for specimen storage; and 7) the availability and type of guidelines for management of unsuitable specimens. The questionnaire was administered to 150 laboratory specialists attending the SIMEL (Italian Society of Laboratory Medicine) National Meeting in June 2006. 107 questionnaires (71.3%) were returned. Data analysis revealed a high degree of variability among laboratories for the time required for check-in, outpatient sampling, sample transportation to the referral laboratory and analysis upon the arrival. Only 31% of laboratories have automated some pre-analytical steps. Of the 87% of laboratories that ship specimens to other facilities without sample preparation, 19% have no standardised protocol for transportation. For conventional clinical chemistry testing, 74% of the laboratories use serum evacuated tubes (59% with and 15% without serum separator), whereas the remaining 26% use lithium-heparin evacuated tubes (11% with and 15% without plasma separator). The storage period and conditions for rerun/retest vary widely. Only 63% of laboratories have a codified procedure for the management of unsuitable specimens, which are recognised by visual inspection (69%) or automatic detection (29%). Only 56% of the laboratories have standardised procedures for the management of unsuitable specimens, which vary widely on a local basis. The survey highlights broad heterogeneity in several pre-analytical processes among Italian laboratories. The lack of reliable guidelines encompassing evidence-based practice is a major problem for the standardisation of this crucial part of the testing process and represents a major challenge for laboratory medicine in the 2000s.
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Quality assurance in the pre-analytical phase of human urine samples by (1)H NMR spectroscopy.
Budde, Kathrin; Gök, Ömer-Necmi; Pietzner, Maik; Meisinger, Christine; Leitzmann, Michael; Nauck, Matthias; Köttgen, Anna; Friedrich, Nele
2016-01-01
Metabolomic approaches investigate changes in metabolite profiles, which may reflect changes in metabolic pathways and provide information correlated with a specific biological process or pathophysiology. High-resolution (1)H NMR spectroscopy is used to identify metabolites in biofluids and tissue samples qualitatively and quantitatively. This pre-analytical study evaluated the effects of storage time and temperature on (1)H NMR spectra from human urine in two settings. Firstly, to evaluate short time effects probably due to acute delay in sample handling and secondly, the effect of prolonged storage up to one month to find markers of sample miss-handling. A number of statistical procedures were used to assess the differences between samples stored under different conditions, including Projection to Latent Structure Discriminant Analysis (PLS-DA), non-parametric testing as well as mixed effect linear regression analysis. The results indicate that human urine samples can be stored at 10 °C for 24 h or at -80 °C for 1 month, as no relevant changes in (1)H NMR fingerprints were observed during these time periods and temperature conditions. However, some metabolites most likely of microbial origin showed alterations during prolonged storage but without facilitating classification. In conclusion, the presented protocol for urine sample handling and semi-automatic metabolite quantification is suitable for large-scale epidemiological studies. Copyright © 2015 Elsevier Inc. All rights reserved.
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History of the preanalytical phase: a personal view
Guder, Walter G.
2014-01-01
In the 70ies of the last century, ther term “preanalytical phase” was introduced in the literature. This term describes all actions and aspects of the “brain to brain circle” of the medical laboratory diagnostic procedure happening before the analytical phase. The author describes his personal experiences in the early seventies and the following history of increasing awareness of this phase as the main cause of “laboratory errors”. This includes the definitions of influence and interference factors as well as the first publications in book, internet, CD-Rom and recent App form over the past 40 years. In addition, a short summary of previous developments as prerequesits of laboratory diagnostic actions is described from the middle age matula for urine collection to the blood collection tubes, anticoagulants and centrifuges. The short review gives a personal view on the possible causes of missing awareness of preanalytical causes of error and future aspects of new techniques in regulation of requests to introduction of quality assurance programs for preanalytical factors. PMID:24627712
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Drone inflight mixing of biochemical samples.
Katariya, Mayur; Chung, Dwayne Chung Kim; Minife, Tristan; Gupta, Harshit; Zahidi, Alifa Afiah Ahmad; Liew, Oi Wah; Ng, Tuck Wah
2018-03-15
Autonomous systems for sample transport to the laboratory for analysis can be improved in terms of timeliness, cost and error mitigation in the pre-analytical testing phase. Drones have been reported for outdoor sample transport but incorporating devices on them to attain homogenous mixing of reagents during flight to enhance sample processing timeliness is limited by payload issues. It is shown here that flipping maneuvers conducted with quadcopters are able to facilitate complete and gentle mixing. This capability incorporated during automated sample transport serves to address an important factor contributing to pre-analytical variability which ultimately impacts on test result reliability. Copyright © 2018 Elsevier Inc. All rights reserved.
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Parboosing, Raveen; Siyaca, Ntombizandile; Moodley, Pravikrishnen
2016-01-01
Background Poor quality dried blood spot (DBS) specimens are usually rejected by virology laboratories, affecting early infant diagnosis of HIV. The practice of combining two incompletely-filled DBS in one specimen preparation tube during pre-analytical specimen processing (i.e., the two-spot method) has been implemented to reduce the number of specimens being rejected for insufficient volume. Objectives This study analysed laboratory data to describe the quality of DBS specimens and the use of the two-spot method over a one-year period, then validated the two-spot method against the standard (one-spot) method. Methods Data on HIV-1 PCR test requests submitted in 2014 to the Department of Virology at Inkosi Albert Luthuli Central Hospital in KwaZulu-Natal province, South Africa were analysed to describe reasons for specimen rejection, as well as results of the two-spot method. The accuracy, lower limit of detection and precision of the two-spot method were assessed. Results Of the 88 481 specimens received, 3.7% were rejected for pre-analytical problems. Of those, 48.9% were rejected as a result of insufficient specimen volume. Two health facilities had significantly more specimen rejections than other facilities. The two-spot method prevented 10 504 specimen rejections. The Pearson correlation coefficient comparing the standard to the two-spot method was 0.997. Conclusions The two-spot method was comparable with the standard method of pre-analytical specimen processing. Two health facilities were identified for targeted retraining on specimen quality. The two-spot method of DBS specimen processing can be used as an adjunct to retraining, to reduce the number of specimens rejected and improve linkage to care. PMID:28879108
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Govender, Kerusha; Parboosing, Raveen; Siyaca, Ntombizandile; Moodley, Pravikrishnen
2016-01-01
Poor quality dried blood spot (DBS) specimens are usually rejected by virology laboratories, affecting early infant diagnosis of HIV. The practice of combining two incompletely-filled DBS in one specimen preparation tube during pre-analytical specimen processing (i.e., the two-spot method) has been implemented to reduce the number of specimens being rejected for insufficient volume. This study analysed laboratory data to describe the quality of DBS specimens and the use of the two-spot method over a one-year period, then validated the two-spot method against the standard (one-spot) method. Data on HIV-1 PCR test requests submitted in 2014 to the Department of Virology at Inkosi Albert Luthuli Central Hospital in KwaZulu-Natal province, South Africa were analysed to describe reasons for specimen rejection, as well as results of the two-spot method. The accuracy, lower limit of detection and precision of the two-spot method were assessed. Of the 88 481 specimens received, 3.7% were rejected for pre-analytical problems. Of those, 48.9% were rejected as a result of insufficient specimen volume. Two health facilities had significantly more specimen rejections than other facilities. The two-spot method prevented 10 504 specimen rejections. The Pearson correlation coefficient comparing the standard to the two-spot method was 0.997. The two-spot method was comparable with the standard method of pre-analytical specimen processing. Two health facilities were identified for targeted retraining on specimen quality. The two-spot method of DBS specimen processing can be used as an adjunct to retraining, to reduce the number of specimens rejected and improve linkage to care.
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Zeugner, Silke; Mayr, Thomas; Zietz, Christian; Aust, Daniela E; Baretton, Gustavo B
2015-01-01
The term "pre-analytics" summarizes all procedures concerned with specimen collection or processing as well as logistical aspects like transport or storage of tissue specimens. All or these variables as well as tissue-specific characteristics affect sample quality. While certain parameters like warm ischemia or tissue-specific characteristics cannot be changed, other parameters can be assessed and optimized. The aim of this study was to determine RNA quality by assessing the RIN values of specimens from different organs and to assess the influence of vacuum preservation. Samples from the GI tract, in general, appear to have lower RNA quality when compared to samples from other organ sites. This may be due to the digestive enzymes or bacterial colonization. Processing time in pathology does not significantly influence RNA quality. Tissue preservation with a vacuum sealer leads to preserved RNA quality over an extended period of time and offers a feasible alternative to minimize the influence of transport time into pathology.
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Systematic Assessment of the Hemolysis Index: Pros and Cons.
Lippi, Giuseppe
2015-01-01
Preanalytical quality is as important as the analytical and postanalytical quality in laboratory diagnostics. After decades of visual inspection to establish whether or not a diagnostic sample may be suitable for testing, automated assessment of hemolysis index (HI) has now become available in a large number of laboratory analyzers. Although most national and international guidelines support systematic assessment of sample quality via HI, there is widespread perception that this indication has not been thoughtfully acknowledged. Potential explanations include concern of increased specimen rejection rate, poor harmonization of analytical techniques, lack of standardized units of measure, differences in instrument-specific cutoff, negative impact on throughput, organization and laboratory economics, and lack of a reliable quality control system. Many of these concerns have been addressed. Evidence now supports automated HI in improving quality and patient safety. These will be discussed. © 2015 Elsevier Inc. All rights reserved.
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Martini, Valeria; Bernardi, Serena; Marelli, Priscilla; Cozzi, Marzia; Comazzi, Stefano
2018-06-01
Objectives Flow cytometry (FC) is becoming increasingly popular among veterinary oncologists for the diagnosis of lymphoma or leukaemia. It is accurate, fast and minimally invasive. Several studies of FC have been carried out in canine oncology and applied with great results, whereas there is limited knowledge and use of this technique in feline patients. This is mainly owing to the high prevalence of intra-abdominal lymphomas in this species and the difficulty associated with the diagnostic procedures needed to collect the sample. The purpose of the present study is to investigate whether any pre-analytical factor might affect the quality of suspected feline lymphoma samples for FC analysis. Methods Ninety-seven consecutive samples of suspected feline lymphoma were retrospectively selected from the authors' institution's FC database. The referring veterinarians were contacted and interviewed about several different variables, including signalment, appearance of the lesion, features of the sampling procedure and the experience of veterinarians performing the sampling. Statistical analyses were performed to assess the possible influence of these variables on the cellularity of the samples and the likelihood of it being finally processed for FC. Results Sample cellularity is a major factor in the likelihood of the sample being processed. Moreover, sample cellularity was significantly influenced by the needle size, with 21 G needles providing the highest cellularity. Notably, the sample cellularity and the likelihood of being processed did not vary between peripheral and intra-abdominal lesions. Approximately half of the cats required pharmacological restraint. Side effects were reported in one case only (transient swelling after peripheral lymph node sampling). Conclusions and relevance FC can be safely applied to cases of suspected feline lymphomas, including intra-abdominal lesions. A 21 G needle should be preferred for sampling. This study provides the basis for the increased use of this minimally invasive, fast and cost-effective technique in feline medicine.
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Khan, Jenna; Lieberman, Joshua A; Lockwood, Christina M
2017-05-01
microRNAs (miRNAs) hold promise as biomarkers for a variety of disease processes and for determining cell differentiation. These short RNA species are robust, survive harsh treatment and storage conditions and may be extracted from blood and tissue. Pre-analytical variables are critical confounders in the analysis of miRNAs: we elucidate these and identify best practices for minimizing sample variation in blood and tissue specimens. Pre-analytical variables addressed include patient-intrinsic variation, time and temperature from sample collection to storage or processing, processing methods, contamination by cells and blood components, RNA extraction method, normalization, and storage time/conditions. For circulating miRNAs, hemolysis and blood cell contamination significantly affect profiles; samples should be processed within 2 h of collection; ethylene diamine tetraacetic acid (EDTA) is preferred while heparin should be avoided; samples should be "double spun" or filtered; room temperature or 4 °C storage for up to 24 h is preferred; miRNAs are stable for at least 1 year at -20 °C or -80 °C. For tissue-based analysis, warm ischemic time should be <1 h; cold ischemic time (4 °C) <24 h; common fixative used for all specimens; formalin fix up to 72 h prior to processing; enrich for cells of interest; validate candidate biomarkers with in situ visualization. Most importantly, all specimen types should have standard and common workflows with careful documentation of relevant pre-analytical variables.
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[The taking and transport of biological samples].
Kerwat, Klaus; Kerwat, Martina; Eberhart, Leopold; Wulf, Hinnerk
2011-05-01
The results of microbiological tests are the foundation for a targetted therapy and the basis for monitoring infections. The quality of each and every laboratory finding depends not only on an error-free analytical process. The pre-analysis handling procedures are of particular importance. They encompass all factors and influences prior to the actual analysis. These include the correct timepoint for sample taking, the packaging and the rapid transport of the material to be investigated. Errors in the pre-analytical processing are the most frequent reasons for inappropriate findings. © Georg Thieme Verlag Stuttgart · New York.
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42 CFR 493.1445 - Standard; Laboratory director responsibilities.
Code of Federal Regulations, 2010 CFR
2010-10-01
... quality laboratory services for all aspects of test performance, which includes the preanalytic, analytic... result is found to be unacceptable or unsatisfactory; (5) Ensure that the quality control and quality assessment programs are established and maintained to assure the quality of laboratory services provided and...
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Management of thyroid cytological material, pre-analytical procedures and bio-banking.
Bode-Lesniewska, Beata; Cochand-Priollet, Beatrix; Straccia, Patrizia; Fadda, Guido; Bongiovanni, Massimo
2018-06-09
Thyroid nodules are common and increasingly detected due to recent advances in imaging techniques. However, clinically relevant thyroid cancer is rare and the mortality from aggressive thyroid cancer remains constant. FNAC (Fine Needle Aspiration Cytology) is a standard method for diagnosing thyroid malignancy and the discrimination of malignant nodules from goiter. As the examined nodules on thyroid FNAC are often small incidental findings, it is important to maintain a low rate of undetermined diagnoses requiring further clinical work up or surgery. The most important factors determining the accuracy of the cytological diagnosis and suitability for biobanking of thyroid FNACs are the quality of the sample and availability of adequate tissue for auxiliary studies. This article analyses technical aspects (pre-analytics) of performing thyroid FNACs, including image guidance and rapid on slide evaluation (ROSE), sample collection methods (conventional slides, liquid based methods (LBC), cell blocks) and storage (bio-banking). The spectrum of the special studies (immunocytochemistry on direct slides or LBC, immunohistochemistry on cell blocks and molecular methods) required for improving the precision of the cytological diagnosis of the thyroid nodules is discussed. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
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Wallin, Olof; Söderberg, Johan; Van Guelpen, Bethany; Stenlund, Hans; Grankvist, Kjell; Brulin, Christine
2010-09-01
Scand J Caring Sci; 2010; 24; 581-591 Blood sample collection and patient identification demand improvement: a questionnaire study of preanalytical practices in hospital wards and laboratories Most errors in venous blood testing result from human mistakes occurring before the sample reach the laboratory. To survey venous blood sampling (VBS) practices in hospital wards and to compare practices with hospital laboratories. Staff in two hospitals (all wards) and two hospital laboratories (314 respondents, response rate 94%), completed a questionnaire addressing issues relevant to the collection of venous blood samples for clinical chemistry testing. The findings suggest that instructions for patient identification and the collection of venous blood samples were not always followed. For example, 79% of the respondents reported the undesirable practice (UDP) of not always using wristbands for patient identification. Similarly, 87% of the respondents noted the UDP of removing venous stasis after the sampling is finished. Compared with the ward staff, a significantly higher proportion of the laboratory staff reported desirable practices regarding the collection of venous blood samples. Neither education nor the existence of established sampling routines was clearly associated with VBS practices among the ward staff. The results of this study, the first of its kind, suggest that a clinically important risk of error is associated with VBS in the surveyed wards. Most important is the risk of misidentification of patients. Quality improvement of blood sample collection is clearly needed, particularly in hospital wards. © 2009 The Authors. Journal compilation © 2009 Nordic College of Caring Science.
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Salinas, Maria; Lopez-Garrigos, Maite; Flores, Emilio; Leiva-Salinas, Carlos
2018-06-01
To study the urinalysis request, pre-analytical sample conditions, and analytical procedures. Laboratories were asked to provide the number of primary care urinalyses requested, and to fill out a questionnaire regarding pre-analytical conditions and analytical procedures. 110 laboratories participated in the study. 232.5 urinalyses/1,000 inhabitants were reported. 75.4% used the first morning urine. The sample reached the laboratory in less than 2 hours in 18.8%, between 2 - 4 hours in 78.3%, and between 4 - 6 hours in the remaining 2.9%. 92.5% combined the use of test strip and particle analysis, and only 7.5% used the strip exclusively. All participants except one performed automated particle analysis depending on strip results; in 16.2% the procedure was only manual. Urinalysis was highly requested. There was a lack of compliance with guidelines regarding time between micturition and analysis that usually involved the combination of strip followed by particle analysis.
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Oyaert, Matthijs; Van Maerken, Tom; Bridts, Silke; Van Loon, Silvi; Laverge, Heleen; Stove, Veronique
2018-03-01
Point-of-care blood gas test results may benefit therapeutic decision making by their immediate impact on patient care. We evaluated the (pre-)analytical performance of a novel cartridge-type blood gas analyzer, the GEM Premier 5000 (Werfen), for the determination of pH, partial carbon dioxide pressure (pCO 2 ), partial oxygen pressure (pO 2 ), sodium (Na + ), potassium (K + ), chloride (Cl - ), ionized calcium ( i Ca 2+ ), glucose, lactate, and total hemoglobin (tHb). Total imprecision was estimated according to the CLSI EP5-A2 protocol. The estimated total error was calculated based on the mean of the range claimed by the manufacturer. Based on the CLSI EP9-A2 evaluation protocol, a method comparison with the Siemens RapidPoint 500 and Abbott i-STAT CG8+ was performed. Obtained data were compared against preset quality specifications. Interference of potential pre-analytical confounders on co-oximetry and electrolyte concentrations were studied. The analytical performance was acceptable for all parameters tested. Method comparison demonstrated good agreement to the RapidPoint 500 and i-STAT CG8+, except for some parameters (RapidPoint 500: pCO 2 , K + , lactate and tHb; i-STAT CG8+: pO 2 , Na + , i Ca 2+ and tHb) for which significant differences between analyzers were recorded. No interference of lipemia or methylene blue on CO-oximetry results was found. On the contrary, significant interference for benzalkonium and hemolysis on electrolyte measurements were found, for which the user is notified by an interferent specific flag. Identification of sample errors from pre-analytical sources, such as interferences and automatic corrective actions, along with the analytical performance, ease of use and low maintenance time of the instrument, makes the evaluated instrument a suitable blood gas analyzer for both POCT and laboratory use. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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Erdal, Erik P; Mitra, Debanjali; Khangulov, Victor S; Church, Stephen; Plokhoy, Elizabeth
2017-03-01
Background Despite advances in clinical chemistry testing, poor blood sample quality continues to impact laboratory operations and the quality of results. While previous studies have identified the preanalytical causes of lower sample quality, few studies have examined the economic impact of poor sample quality on the laboratory. Specifically, the costs associated with workarounds related to fibrin and gel contaminants remain largely unexplored. Methods A quantitative survey of clinical chemistry laboratory stakeholders across 10 international regions, including countries in North America, Europe and Oceania, was conducted to examine current blood sample testing practices, sample quality issues and practices to remediate poor sample quality. Survey data were used to estimate costs incurred by laboratories to mitigate sample quality issues. Results Responses from 164 participants were included in the analysis, which was focused on three specific issues: fibrin strands, fibrin masses and gel globules. Fibrin strands were the most commonly reported issue, with an overall incidence rate of ∼3%. Further, 65% of respondents indicated that these issues contribute to analyzer probe clogging, and the majority of laboratories had visual inspection and manual remediation practices in place to address fibrin- and gel-related quality problems (55% and 70%, respectively). Probe maintenance/replacement, visual inspection and manual remediation were estimated to carry significant costs for the laboratories surveyed. Annual cost associated with lower sample quality and remediation related to fibrin and/or gel globules for an average US laboratory was estimated to be $100,247. Conclusions Measures to improve blood sample quality present an important step towards improved laboratory operations.
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[The Scope, Quality and Safety Requirements of Drug Abuse Testing].
Küme, Tuncay; Karakükcü, Çiğdem; Pınar, Aslı; Coşkunol, Hakan
2017-01-01
The aim of this review is to inform about the scopes and requirements of drug abuse testing. Drug abuse testing is one of the tools for determination of drug use. It must fulfill the quality and safety requirements in judgmental legal and administrative decisions. Drug abuse testing must fulfill some requirements like selection of the appropriate test matrix, appropriate screening test panel, sampling in detection window, patient consent, identification of the donor, appropriate collection site, sample collection with observation, identification and control of the sample, specimen custody chain in preanalytical phase; analysis in authorized laboratories, specimen validity tests, reliable testing METHODS, strict quality control, two-step analysis in analytical phase; storage of the split specimen, confirmation of the split specimen in the objection, result custody chain, appropriate cut-off concentration, the appropriate interpretation of the result in postanalytical phase. The workflow and analytical processes of drug abuse testing are explained in last regulation of the Department of Medical Laboratory Services, Ministry of Health in Turkey. The clinical physicians have to know and apply the quality and safety requirements in drug abuse testing according to last regulations in Turkey.
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Jacobsz, Lourens A; Zemlin, Annalise E; Roos, Mark J; Erasmus, Rajiv T
2011-10-14
Recent publications report that up to 70% of total laboratory errors occur in the pre-analytical phase. Identification of specific problems highlights pre-analytic processes susceptible to errors. The rejection of unsuitable samples can lead to delayed turnaround time and affect patient care. A retrospective audit was conducted investigating the rejection rate of routine blood specimens received at chemistry and haematology laboratories over a 2-week period. The reasons for rejection and potential clinical impact of these rejections were investigated. Thirty patient files were randomly selected and examined to assess the impact of these rejections on clinical care. A total of 32,910 specimens were received during the study period, of which 481 were rejected, giving a rejection rate of 1.46%. The main reasons for rejection were inappropriate clotting (30%) and inadequate sample volume (22%). Only 51.7% of rejected samples were repeated and the average time for a repeat sample to reach the laboratory was about 5 days (121 h). Of the repeated samples, 5.1% had results within critical values. Examination of patient folders showed that in 40% of cases the rejection of samples had an impact on patient care. The evaluation of pre-analytical processes in the laboratory, with regard to sample rejection, allowed one to identify problem areas where improvement is necessary. Rejected samples due to factors out of the laboratory's control had a definite impact on patient care and can thus affect customer satisfaction. Clinicians should be aware of these factors to prevent such rejections.
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Volani, Chiara; Caprioli, Giulia; Calderisi, Giovanni; Sigurdsson, Baldur B; Rainer, Johannes; Gentilini, Ivo; Hicks, Andrew A; Pramstaller, Peter P; Weiss, Guenter; Smarason, Sigurdur V; Paglia, Giuseppe
2017-10-01
Volumetric absorptive microsampling (VAMS) is a novel approach that allows single-drop (10 μL) blood collection. Integration of VAMS with mass spectrometry (MS)-based untargeted metabolomics is an attractive solution for both human and animal studies. However, to boost the use of VAMS in metabolomics, key pre-analytical questions need to be addressed. Therefore, in this work, we integrated VAMS in a MS-based untargeted metabolomics workflow and investigated pre-analytical strategies such as sample extraction procedures and metabolome stability at different storage conditions. We first evaluated the best extraction procedure for the polar metabolome and found that the highest number and amount of metabolites were recovered upon extraction with acetonitrile/water (70:30). In contrast, basic conditions (pH 9) resulted in divergent metabolite profiles mainly resulting from the extraction of intracellular metabolites originating from red blood cells. In addition, the prolonged storage of blood samples at room temperature caused significant changes in metabolome composition, but once the VAMS devices were stored at - 80 °C, the metabolome remained stable for up to 6 months. The time used for drying the sample did also affect the metabolome. In fact, some metabolites were rapidly degraded or accumulated in the sample during the first 48 h at room temperature, indicating that a longer drying step will significantly change the concentration in the sample. Graphical abstract Volumetric absorptive microsampling (VAMS) is a novel technology that allows single-drop blood collection and, in combination with mass spectrometry (MS)-based untargeted metabolomics, represents an attractive solution for both human and animal studies. In this work, we integrated VAMS in a MS-based untargeted metabolomics workflow and investigated pre-analytical strategies such as sample extraction procedures and metabolome stability at different storage conditions. The latter revealed that prolonged storage of blood samples at room temperature caused significant changes in metabolome composition, but if VAMS devices were stored at - 80 °C, the metabolome remained stable for up to 6 months.
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Kumar, Savitha Anil; Jayanna, Prashanth; Prabhudesai, Shilpa; Kumar, Ajai
2014-01-01
To collect and tabulate errors and nonconformities in the preanalytical, analytical, and postanalytical process phases in a diagnostic clinical laboratory that supports a super-specialty cancer center in India, and identify areas of potential improvement in patient services. We collected data from our laboratory during a period of 24 months. Departments in the study included clinical biochemistry, hematology, clinical pathology, microbiology and serology, surgical pathology, and molecular pathology. We had initiated quality assessment based on international standards in our laboratory in 2010, with the aim of obtaining accreditation by national and international governing bodies. We followed the guidelines specified by International Organization for Standardization (ISO) 15189:2007 to identify noncompliant elements of our processes. Among a total of 144,030 specimens that our referral laboratory received during the 2-year period of our study, we uncovered an overall error rate for all 3 process phases of 1.23%; all of our error rates closely approximated the results from our peer institutions. Errors were most common in the preanalytical phase in both years of study; preanalytical- and postanalytical-phase errors constituted more than 90% of all errors. Further improvements are warranted in laboratory services and are contingent on adequate training and interdepartmental communication and cooperation. Copyright© by the American Society for Clinical Pathology (ASCP).
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Dietel, Manfred; Bubendorf, Lukas; Dingemans, Anne-Marie C; Dooms, Christophe; Elmberger, Göran; García, Rosa Calero; Kerr, Keith M; Lim, Eric; López-Ríos, Fernando; Thunnissen, Erik; Van Schil, Paul E; von Laffert, Maximilian
2016-01-01
Background There is currently no Europe-wide consensus on the appropriate preanalytical measures and workflow to optimise procedures for tissue-based molecular testing of non-small-cell lung cancer (NSCLC). To address this, a group of lung cancer experts (see list of authors) convened to discuss and propose standard operating procedures (SOPs) for NSCLC. Methods Based on earlier meetings and scientific expertise on lung cancer, a multidisciplinary group meeting was aligned. The aim was to include all relevant aspects concerning NSCLC diagnosis. After careful consideration, the following topics were selected and each was reviewed by the experts: surgical resection and sampling; biopsy procedures for analysis; preanalytical and other variables affecting quality of tissue; tissue conservation; testing procedures for epidermal growth factor receptor, anaplastic lymphoma kinase and ROS proto-oncogene 1, receptor tyrosine kinase (ROS1) in lung tissue and cytological specimens; as well as standardised reporting and quality control (QC). Finally, an optimal workflow was described. Results Suggested optimal procedures and workflows are discussed in detail. The broad consensus was that the complex workflow presented can only be executed effectively by an interdisciplinary approach using a well-trained team. Conclusions To optimise diagnosis and treatment of patients with NSCLC, it is essential to establish SOPs that are adaptable to the local situation. In addition, a continuous QC system and a local multidisciplinary tumour-type-oriented board are essential. PMID:26530085
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[Automation and organization of technological process of urinalysis].
Kolenkin, S M; Kishkun, A A; Kol'chenko, O L
2000-12-01
Results of introduction into practice of a working model of industrial technology of laboratory studies and KONE Specific Supra and Miditron M devices are shown as exemplified by clinical analysis of the urine. This technology helps standardize all stages and operations, improves the efficiency of quality control of laboratory studies, rationally organizes the work at all stages of the process, creates a system for permanent improvement of the efficiency of investigations at the preanalytical, analytical, and postanalytical stages of technological process of laboratory studies. As a result of introduction of this technology into laboratory practice, violations of quality criteria of clinical urinalysis decreased from 15 to 8% at the preanalytical stage and from 6 to 3% at the analytical stage. Automation of the analysis decreased the need in reagents 3-fold and improved the productivity at the analytical stage 4-fold.
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Bielohuby, Maximilian; Popp, Sarah; Bidlingmaier, Martin
2012-01-01
Researchers analyse hormones to draw conclusions from changes in hormone concentrations observed under specific physiological conditions and to elucidate mechanisms underlying their biological variability. It is, however, frequently overlooked that also circumstances occurring after collection of biological samples can significantly affect the hormone concentrations measured, owing to analytical and pre-analytical variability. Whereas the awareness for such potential confounders is increasing in human laboratory medicine, there is sometimes limited consensus about the control of these factors in rodent studies. In this guide, we demonstrate how such factors can affect reliability and consequent interpretation of the data from immunoassay measurements of circulating metabolic hormones in rodent studies. We also compare the knowledge about such factors in rodent studies to recent recommendations established for biomarker studies in humans and give specific practical recommendations for the control of pre-analytical conditions in metabolic studies in rodents. PMID:24024118
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[Management of pre-analytical nonconformities].
Berkane, Z; Dhondt, J L; Drouillard, I; Flourié, F; Giannoli, J M; Houlbert, C; Surgat, P; Szymanowicz, A
2010-12-01
The main nonconformities enumerated to facilitate consensual codification. In each case, an action is defined: refusal to realize the examination with request of a new sample, request of information or correction, results cancellation, nurse or physician information. A traceability of the curative, corrective and preventive actions is needed. Then, methodology and indicators are proposed to assess nonconformity and to follow the quality improvements. The laboratory information system can be used instead of dedicated software. Tools for the follow-up of nonconformities scores are proposed. Finally, we propose an organization and some tools allowing the management and control of the nonconformities occurring during the pre-examination phase.
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IL8 and IL16 levels indicate serum and plasma quality.
Kofanova, Olga; Henry, Estelle; Quesada, Rocio Aguilar; Bulla, Alexandre; Linares, Hector Navarro; Lescuyer, Pierre; Shea, Kathi; Stone, Mars; Tybring, Gunnel; Bellora, Camille; Betsou, Fay
2018-02-09
Longer pre-centrifugation times alter the quality of serum and plasma samples. Markers for such delays in sample processing and hence for the sample quality, have been identified. Twenty cytokines in serum, EDTA plasma and citrate plasma samples were screened for changes in concentration induced by extended blood pre-centrifugation delays at room temperature. The two cytokines that showed the largest changes were further validated for their "diagnostic performance" in identifying serum or plasma samples with extended pre-centrifugation times. In this study, using R&D Systems ELISA kits, EDTA plasma samples and serum samples with a pre-centrifugation delay longer than 24 h had an IL16 concentration higher than 313 pg/mL, and an IL8 concentration higher than 125 pg/mL, respectively. EDTA plasma samples with a pre-centrifugation delay longer than 48 h had an IL16 concentration higher than 897 pg/mL, citrate plasma samples had an IL8 concentration higher than 21.5 pg/mL and serum samples had an IL8 concentration higher than 528 pg/mL. These robust and accurate tools, based on simple and commercially available ELISA assays can greatly facilitate qualification of serum and plasma legacy collections with undocumented pre-analytics.
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A proteomics performance standard to support measurement quality in proteomics.
Beasley-Green, Ashley; Bunk, David; Rudnick, Paul; Kilpatrick, Lisa; Phinney, Karen
2012-04-01
The emergence of MS-based proteomic platforms as a prominent technology utilized in biochemical and biomedical research has increased the need for high-quality MS measurements. To address this need, National Institute of Standards and Technology (NIST) reference material (RM) 8323 yeast protein extract is introduced as a proteomics quality control material for benchmarking the preanalytical and analytical performance of proteomics-based experimental workflows. RM 8323 yeast protein extract is based upon the well-characterized eukaryote Saccharomyces cerevisiae and can be utilized in the design and optimization of proteomics-based methodologies from sample preparation to data analysis. To demonstrate its utility as a proteomics quality control material, we coupled LC-MS/MS measurements of RM 8323 with the NIST MS Quality Control (MSQC) performance metrics to quantitatively assess the LC-MS/MS instrumentation parameters that influence measurement accuracy, repeatability, and reproducibility. Due to the complexity of the yeast proteome, we also demonstrate how NIST RM 8323, along with the NIST MSQC performance metrics, can be used in the evaluation and optimization of proteomics-based sample preparation methods. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Schultze, A E; Irizarry, A R
2017-02-01
Veterinary clinical pathologists are well positioned via education and training to assist in investigations of unexpected results or increased variation in clinical pathology data. Errors in testing and unexpected variability in clinical pathology data are sometimes referred to as "laboratory errors." These alterations may occur in the preanalytical, analytical, or postanalytical phases of studies. Most of the errors or variability in clinical pathology data occur in the preanalytical or postanalytical phases. True analytical errors occur within the laboratory and are usually the result of operator or instrument error. Analytical errors are often ≤10% of all errors in diagnostic testing, and the frequency of these types of errors has decreased in the last decade. Analytical errors and increased data variability may result from instrument malfunctions, inability to follow proper procedures, undetected failures in quality control, sample misidentification, and/or test interference. This article (1) illustrates several different types of analytical errors and situations within laboratories that may result in increased variability in data, (2) provides recommendations regarding prevention of testing errors and techniques to control variation, and (3) provides a list of references that describe and advise how to deal with increased data variability.
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Exploring the initial steps of the testing process: frequency and nature of pre-preanalytic errors.
Carraro, Paolo; Zago, Tatiana; Plebani, Mario
2012-03-01
Few data are available on the nature of errors in the so-called pre-preanalytic phase, the initial steps of the testing process. We therefore sought to evaluate pre-preanalytic errors using a study design that enabled us to observe the initial procedures performed in the ward, from the physician's test request to the delivery of specimens in the clinical laboratory. After a 1-week direct observational phase designed to identify the operating procedures followed in 3 clinical wards, we recorded all nonconformities and errors occurring over a 6-month period. Overall, the study considered 8547 test requests, for which 15 917 blood sample tubes were collected and 52 982 tests undertaken. No significant differences in error rates were found between the observational phase and the overall study period, but underfilling of coagulation tubes was found to occur more frequently in the direct observational phase (P = 0.043). In the overall study period, the frequency of errors was found to be particularly high regarding order transmission [29 916 parts per million (ppm)] and hemolysed samples (2537 ppm). The frequency of patient misidentification was 352 ppm, and the most frequent nonconformities were test requests recorded in the diary without the patient's name and failure to check the patient's identity at the time of blood draw. The data collected in our study confirm the relative frequency of pre-preanalytic errors and underline the need to consensually prepare and adopt effective standard operating procedures in the initial steps of laboratory testing and to monitor compliance with these procedures over time.
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Peyron, Pierre-Antoine; Baccino, Éric; Nagot, Nicolas; Lehmann, Sylvain; Delaby, Constance
2017-02-01
Determination of skin wound vitality is an important issue in forensic practice. No reliable biomarker currently exists. Quantification of inflammatory cytokines in injured skin with MSD ® technology is an innovative and promising approach. This preliminary study aims to develop a protocol for the preparation and the analysis of skin samples. Samples from ante mortem wounds, post mortem wounds, and intact skin ("control samples") were taken from corpses at the autopsy. After an optimization of the pre-analytical protocol had been performed in terms of skin homogeneisation and proteic extraction, the concentration of TNF-α was measured in each sample with the MSD ® approach. Then five other cytokines of interest (IL-1β, IL-6, IL-10, IL-12p70 and IFN-γ) were simultaneously quantified with a MSD ® multiplex assay. The optimal pre-analytical conditions consist in a proteic extraction from a 6 mm diameter skin sample, in a PBS buffer with triton 0,05%. Our results show the linearity and the reproductibility of the TNF-α quantification with MSD ® , and an inter- and intra-individual variability of the concentrations of proteins. The MSD ® multiplex assay is likely to detect differential skin concentrations for each cytokine of interest. This preliminary study was used to develop and optimize the pre-analytical and analytical conditions of the MSD ® method using injured and healthy skin samples, for the purpose of looking for and identifying the cytokine, or the set of cytokines, that may be biomarkers of skin wound vitality.
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NASA Astrophysics Data System (ADS)
Treado, Patrick J.; Stewart, Shona D.; Smith, Aaron; Kirschner, Heather; Post, Christopher; Overholt, Bergein F.
2016-03-01
Colorectal cancer (CRC) is the third most common cancer in men and women in the United States. Raman Molecular Imaging (RMI) is an effective technique to evaluate human tissue, cells and bodily fluids, including blood serum for disease diagnosis. ChemImage Corporation, in collaboration with clinicians, has been engaged in development of an in vitro diagnostic Raman assay focused on CRC detection. The Raman Assay for Colorectal Cancer (RACC) exploits the high specificity of Raman imaging to distinguish diseased from normal dried blood serum droplets without additional reagents. Pilot Study results from testing of hundreds of biobank patient samples have demonstrated that RACC detects CRC with high sensitivity and specificity. However, expanded clinical trials, which are ongoing, are revealing a host of important preanalytical considerations associated with sample collection, sample storage and stability, sample shipping, sample preparation and sample interferents, which impact detection performance. Results from recent clinical studies will be presented.
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Campi-Azevedo, Ana Carolina; Peruhype-Magalhães, Vanessa; Coelho-Dos-Reis, Jordana Grazziela; Costa-Pereira, Christiane; Yamamura, Anna Yoshida; Lima, Sheila Maria Barbosa de; Simões, Marisol; Campos, Fernanda Magalhães Freire; de Castro Zacche Tonini, Aline; Lemos, Elenice Moreira; Brum, Ricardo Cristiano; de Noronha, Tatiana Guimarães; Freire, Marcos Silva; Maia, Maria de Lourdes Sousa; Camacho, Luiz Antônio Bastos; Rios, Maria; Chancey, Caren; Romano, Alessandro; Domingues, Carla Magda; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis
2017-09-01
Technological innovations in vaccinology have recently contributed to bring about novel insights for the vaccine-induced immune response. While the current protocols that use peripheral blood samples may provide abundant data, a range of distinct components of whole blood samples are required and the different anticoagulant systems employed may impair some properties of the biological sample and interfere with functional assays. Although the interference of heparin in functional assays for viral neutralizing antibodies such as the functional plaque-reduction neutralization test (PRNT), considered the gold-standard method to assess and monitor the protective immunity induced by the Yellow fever virus (YFV) vaccine, has been well characterized, the development of pre-analytical treatments is still required for the establishment of optimized protocols. The present study intended to optimize and evaluate the performance of pre-analytical treatment of heparin-collected blood samples with ecteola-cellulose (ECT) to provide accurate measurement of anti-YFV neutralizing antibodies, by PRNT. The study was designed in three steps, including: I. Problem statement; II. Pre-analytical steps; III. Analytical steps. Data confirmed the interference of heparin on PRNT reactivity in a dose-responsive fashion. Distinct sets of conditions for ECT pre-treatment were tested to optimize the heparin removal. The optimized protocol was pre-validated to determine the effectiveness of heparin plasma:ECT treatment to restore the PRNT titers as compared to serum samples. The validation and comparative performance was carried out by using a large range of serum vs heparin plasma:ECT 1:2 paired samples obtained from unvaccinated and 17DD-YFV primary vaccinated subjects. Altogether, the findings support the use of heparin plasma:ECT samples for accurate measurement of anti-YFV neutralizing antibodies. Copyright © 2017 Elsevier B.V. All rights reserved.
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Makhumula-Nkhoma, Nellie; Whittaker, Vicki; McSherry, Robert
2015-02-01
To investigate the association between confidence level in venepuncture and knowledge in determining causes of blood sample haemolysis among clinical staff and phlebotomists. Various collection methods are used to perform venepuncture, also called phlebotomy, the act of drawing blood from a patient using a needle. The collection method used has an impact on preanalytical blood sample haemolysis. Haemolysis is the breakdown of red blood cells, which makes the sample unsuitable. Despite available evidence on the common causes, extensive literature search showed a lack of published evidence on the association of haemolysis with staff confidence and knowledge. A quantitative primary research design using survey method. A purposive sample of 290 clinical staff and phlebotomists conducting venepuncture in one North England hospital participated in this quantitative survey. A three-section web-based questionnaire comprising demographic profile, confidence and competence levels, and knowledge sections was used to collect data in 2012. The chi-squared test for independence was used to compare the distribution of responses for categorical data. anova was used to determine mean difference in the knowledge scores of staff with different confidence levels. Almost 25% clinical staff and phlebotomists participated in the survey. There was an increase in confidence at the last venepuncture among staff of all categories. While doctors' scores were higher compared with healthcare assistants', p ≤ 0·001, nurses' were of wide range and lowest. There was no statistically significant difference (at the 5% level) in the total knowledge scores and confidence level at the last venepuncture F(2,4·690) = 1·67, p = 0·31 among staff of all categories. Evidence-based measures are required to boost staff knowledge base of preanalytical blood sample haemolysis for standardised and quality service. Monitoring and evaluation of the training, conducting and monitoring haemolysis rate are equally crucial. Although the hospital is succeeding in providing regular training in venepuncture, this is only one aspect of quality. The process and outcome also need interventions. © 2014 John Wiley & Sons Ltd.
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42 CFR 493.1200 - Introduction.
Code of Federal Regulations, 2011 CFR
2011-10-01
... (that is, preanalytic, analytic, and postanalytic) as well as general laboratory systems. (b) The...) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Quality System for Nonwaived Testing § 493.1200 Introduction. (a) Each laboratory that performs nonwaived testing must establish and maintain written policies...
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Rapi, Stefano; Berardi, Margherita; Cellai, Filippo; Ciattini, Samuele; Chelazzi, Laura; Ognibene, Agostino; Rubeca, Tiziana
2017-07-24
Information on preanalytical variability is mandatory to bring laboratories up to ISO 15189 requirements. Fecal sampling is greatly affected by lack of harmonization in laboratory medicine. The aims of this study were to obtain information on the devices used for fecal sampling and to explore the effect of different amounts of feces on the results from the fecal immunochemical test for hemoglobin (FIT-Hb). Four commercial sample collection devices for quantitative FIT-Hb measurements were investigated. The volume of interest (VOI) of the probes was measured from diameter and geometry. Quantitative measurements of the mass of feces were carried out by gravimetry. The effects of an increased amount of feces on the analytical environment were investigated measuring the Hb values with a single analytical method. VOI was 8.22, 7.1 and 9.44 mm3 for probes that collected a target of 10 mg of feces, and 3.08 mm3 for one probe that targeted 2 mg of feces. The ratio between recovered and target amounts of devices ranged from 56% to 121%. Different changes in the measured Hb values were observed, in adding increasing amounts of feces in commercial buffers. The amounts of collected materials are related to the design of probes. Three out 4 manufacturers declare the same target amount using different sampling volumes and obtaining different amounts of collected materials. The introduction of a standard probes to reduce preanalytical variability could be an useful step for fecal test harmonization and to fulfill the ISO 15189 requirements.
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Caboux, Elodie; Lallemand, Christophe; Ferro, Gilles; Hémon, Bertrand; Mendy, Maimuna; Biessy, Carine; Sims, Matt; Wareham, Nick; Britten, Abigail; Boland, Anne; Hutchinson, Amy; Siddiq, Afshan; Vineis, Paolo; Riboli, Elio; Romieu, Isabelle; Rinaldi, Sabina; Gunter, Marc J.; Peeters, Petra H. M.; van der Schouw, Yvonne T.; Travis, Ruth; Bueno-de-Mesquita, H. Bas; Canzian, Federico; Sánchez, Maria-José; Skeie, Guri; Olsen, Karina Standahl; Lund, Eiliv; Bilbao, Roberto; Sala, Núria; Barricarte, Aurelio; Palli, Domenico; Navarro, Carmen; Panico, Salvatore; Redondo, Maria Luisa; Polidoro, Silvia; Dossus, Laure; Boutron-Ruault, Marie Christine; Clavel-Chapelon, Françoise; Trichopoulou, Antonia; Trichopoulos, Dimitrios; Lagiou, Pagona; Boeing, Heiner; Fisher, Eva; Tumino, Rosario; Agnoli, Claudia; Hainaut, Pierre
2012-01-01
The European Prospective Investigation into Cancer and nutrition (EPIC) is a long-term, multi-centric prospective study in Europe investigating the relationships between cancer and nutrition. This study has served as a basis for a number of Genome-Wide Association Studies (GWAS) and other types of genetic analyses. Over a period of 5 years, 52,256 EPIC DNA samples have been extracted using an automated DNA extraction platform. Here we have evaluated the pre-analytical factors affecting DNA yield, including anthropometric, epidemiological and technical factors such as center of subject recruitment, age, gender, body-mass index, disease case or control status, tobacco consumption, number of aliquots of buffy coat used for DNA extraction, extraction machine or procedure, DNA quantification method, degree of haemolysis and variations in the timing of sample processing. We show that the largest significant variations in DNA yield were observed with degree of haemolysis and with center of subject recruitment. Age, gender, body-mass index, cancer case or control status and tobacco consumption also significantly impacted DNA yield. Feedback from laboratories which have analyzed DNA with different SNP genotyping technologies demonstrate that the vast majority of samples (approximately 88%) performed adequately in different types of assays. To our knowledge this study is the largest to date to evaluate the sources of pre-analytical variations in DNA extracted from peripheral leucocytes. The results provide a strong evidence-based rationale for standardized recommendations on blood collection and processing protocols for large-scale genetic studies. PMID:22808065
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Zhao, Xiaoyan; Qureshi, Ferhan; Eastman, P Scott; Manning, William C; Alexander, Claire; Robinson, William H; Hesterberg, Lyndal K
2012-04-30
Variability in pre-analytical blood sampling and handling can significantly impact results obtained in quantitative immunoassays. Understanding the impact of these variables is critical for accurate quantification and validation of biomarker measurements. Particularly, in the design and execution of large clinical trials, even small differences in sample processing and handling can have dramatic effects in analytical reliability, results interpretation, trial management and outcome. The effects of two common blood sampling methods (serum vs. plasma) and two widely-used serum handling methods (on the clot with ambient temperature shipping, "traditional", vs. centrifuged with cold chain shipping, "protocol") on protein and autoantibody concentrations were examined. Matched serum and plasma samples were collected from 32 rheumatoid arthritis (RA) patients representing a wide range of disease activity status. Additionally, a set of matched serum samples with two sample handling methods was collected. One tube was processed per manufacturer's instructions and shipped overnight on cold packs (protocol). The matched tube, without prior centrifugation, was simultaneously shipped overnight at ambient temperatures (traditional). Upon delivery, the traditional tube was centrifuged. All samples were subsequently aliquoted and frozen prior to analysis of protein and autoantibody biomarkers. Median correlation between paired serum and plasma across all autoantibody assays was 0.99 (0.98-1.00) with a median % difference of -3.3 (-7.5 to 6.0). In contrast, observed protein biomarker concentrations were significantly affected by sample types, with median correlation of 0.99 (0.33-1.00) and a median % difference of -10 (-55 to 23). When the two serum collection/handling methods were compared, the median correlation between paired samples for autoantibodies was 0.99 (0.91-1.00) with a median difference of 4%. In contrast, significant increases were observed in protein biomarker concentrations among certain biomarkers in samples processed with the 'traditional' method. Autoantibody quantification appears robust to both sample type (plasma vs. serum) and pre-analytical sample collection/handling methods (protocol vs. traditional). In contrast, for non-antibody protein biomarker concentrations, sample type had a significant impact; plasma samples generally exhibit decreased protein biomarker concentrations relative to serum. Similarly, sample handling significantly impacted the variability of protein biomarker concentrations. When biomarker concentrations are combined algorithmically into a single test score such as a multi-biomarker disease activity test for rheumatoid arthritis (MBDA), changes in protein biomarker concentrations may result in a bias of the score. These results illustrate the importance of characterizing pre-analytical methodology, sample type, sample processing and handling procedures for clinical testing in order to ensure test accuracy. Copyright © 2012 Elsevier B.V. All rights reserved.
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Tormo, Consuelo; Lumbreras, Blanca; Santos, Ana; Romero, Luis; Conca, Minerva
2009-12-01
-The preanalytic phase of 24-hour urine collection, before clinical analysis, requires the active participation of patients and usually takes place outside the laboratory. -We verify whether distribution of adequate information to health care personnel and patients will result in fewer preanalytic incidents. We also determine the intraindividual biologic variability associated with micturition and the corresponding reference change value (RCV). -The intervention provided training for 24-hour urine collection to the health care personnel of the 20th health district of the Valencian community in Spain. The preanalytic incidents related to 24-hour micturition were estimated before and after the intervention. An opinion survey on the problems involved in urine collection was also conducted among patients. The Harris formula was used to calculate the RCV. -Before the intervention, 130 preanalytic incidents were recorded (11.5%) and after the intervention, 76 (8.6%) (P = .04) were recorded. Of the 130 incidents recorded before the intervention, 63 (48.5%) involved omission to indicate the urine volume, and of the 76 incidents recorded after the intervention, only 1 (1.3%) (P < .001) involved this omission. Forty of 302 patients (13.2%) surveyed reported problems and more than half (175; 57.9%) had to collect various urine samples sequentially. The RCV determined was 54.5% for a percentage of variation in volume of 24-hour urine (PVVI) of 19.0 +/- 16.5%. Therefore, micturition associated with a PVVI >+/-54.5% suggests that 24-hour urine collection by the patient was incomplete. The results obtained when applying the RCV after the intervention showed that 6.3% of the 24-hour urine samples should be rejected. -The percentage of preanalytic incidents was reduced by providing health care personnel with information and training. The percentage of variation in volume of 24-hour urine can be used to evaluate the variation in patients' micturition. Reference change value was shown to be useful when determining whether 24-hour urine was properly collected.
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Biospecimen Reporting for Improved Study Quality
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moore, Ph.D., Helen M.; Kelly, Ph.D., Andrea B.; Jewell, Ph.D., Scott D.
Human biospecimens are subjected to collection, processing, and storage that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research that uses human tissues, it is crucial that information on the handling of biospecimens be reported in a thorough, accurate, and standardized manner. The Biospecimen Reporting for Improved Study Quality (BRISQ) recommendations outlined herein are intended to applymore » to any study in which human biospecimens are used. The purpose of reporting these details is to supply others, from researchers to regulators, with more consistent and standardized information to better evaluate, interpret, compare, and reproduce the experimental results. The BRISQ guidelines are proposed as an important and timely resource tool to strengthen communication and publications on biospecimen-related research and to help reassure patient contributors and the advocacy community that their contributions are valued and respected.« less
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Damato, Charlotte; Rickard, Dana
2015-03-01
As part of a strategic quality improvement plan, laboratory management at Sarasota Memorial Health Care System (SMHCS) focused its efforts on improving preanalytical work flow and blood collection processes-both negatively affected by hemolyzed specimens. When hemolysis is detected in a blood specimen, blood may need to be re-collected, resulting in bottlenecks and rework all along the value stream. From July through December 2009, hemolysis averaged 9.8% in the Emergency Care Center (ECC) and 3.4% housewide. The goal was set to reduce hemolysis to 2%. The project team identified hemolysis as one of seven factors contributing to non-value-added activities and bottlenecks in blood collection and preanalytical processes. Observations and interviews helped to identify error-prone practices and process variation. To verify the root causes of hemolysis, the findings were compared against best practices. The team developed a housewide protocol, standardized collection processes, created competency-based training, and enhanced ECC hiring practices. During December 2010-March 2011, following initial housewide interventions and ECC self-sustaining solutions, ECC hemolysis decreased by 91%-from 9.8% (423 hemolyzed/4,295 collected) to 0.88% (58 hemolyzed/6,560 collected). Housewide hemolysis decreased by 59%-from 3.4% (2,046 hemolyzed/60,307 collected) to 1.39% (619 hemolyzed/44,528 collected). Since the project, hemolysis has continued to trend downward; the mean percentage has consistently been < .05% for the ECC and < 1% housewide. Lean-Six Sigma tools helped to pinpoint hemolysis as a key inefficiency in blood collection and preanalytical work flow. Although focused on the ECC, the project team standardized blood collection practices and instituted quality devices to achieve hemolysis reductions housewide.
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Casson, Florence Boux de; Moal, Valérie; Gauchez, Anne-Sophie; Moineau, Marie-Pierre; Sault, Corinne; Schlageter, Marie-Hélène; Massart, Catherine
2017-04-01
The aim of this study was to evaluate the pre-analytical factors contributing to uncertainty in thyroglobulin measurement in fluids from fine-needle aspiration (FNA) washout of cervical lymph nodes. We studied pre-analytical stability, in different conditions, of 41 samples prepared with concentrated solutions of thyroglobulin (FNA washout or certified standard) diluted in physiological saline solution or buffer containing 6% albumin. In this buffer, over time, no changes in thyroglobulin concentrations were observed in all storage conditions tested. In albumin free saline solution, thyroglobulin recovery rates depended on initial sample concentrations and on modalities of their conservation (in conventional storage tubes, recovery mean was 56% after 3 hours-storage at room temperature and 19% after 24 hours-storage for concentrations ranged from 2 to 183 μg/L; recovery was 95%, after 3 hours or 24 hours-storage at room temperature, for a concentration of 5,656 μg/L). We show here that these results are due to non-specific adsorption of thyroglobulin in storage tubes, which depends on sample protein concentrations. We also show that possible contamination of fluids from FNA washout by plasma proteins do not always adequately prevent this adsorption. In conclusion, non-specific adsorption in storage tubes strongly contributes to uncertainty in thyroglobulin measurement in physiological saline solution. It is therefore recommended, for FNA washout, to use a buffer containing proteins provided by the laboratory.
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Contamination of dried blood spots - an underestimated risk in newborn screening.
Winter, Theresa; Lange, Anja; Hannemann, Anke; Nauck, Matthias; Müller, Cornelia
2018-01-26
Newborn screening (NBS) is an established screening procedure in many countries worldwide, aiming at the early detection of inborn errors of metabolism. For decades, dried blood spots have been the standard specimen for NBS. The procedure of blood collection is well described and standardized and includes many critical pre-analytical steps. We examined the impact of contamination of some anticipated common substances on NBS results obtained from dry spot samples. This possible pre-analytical source of uncertainty has been poorly examined in the past. Capillary blood was obtained from 15 adult volunteers and applied to 10 screening filter papers per volunteer. Nine filter papers were contaminated without visible trace. The contaminants were baby diaper rash cream, baby wet wipes, disinfectant, liquid infant formula, liquid infant formula hypoallergenic (HA), ultrasonic gel, breast milk, feces, and urine. The differences between control and contaminated samples were evaluated for 45 NBS quantities. We estimated if the contaminations might lead to false-positive NBS results. Eight of nine investigated contaminants significantly altered NBS analyte concentrations and potentially caused false-positive screening outcomes. A contamination with feces was most influential, affecting 24 of 45 tested analytes followed by liquid infant formula (HA) and urine, affecting 19 and 13 of 45 analytes, respectively. A contamination of filter paper samples can have a substantial effect on the NBS results. Our results underline the importance of good pre-analytical training to make the staff aware of the threat and ensure reliable screening results.
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42 CFR 493.1240 - Condition: Preanalytic systems.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Preanalytic systems. 493.1240 Section 493.1240 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... of the preanalytic systems and correct identified problems as specified in § 493.1249 for each...
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Gosselin, Robert C; Adcock, Dorothy M; Bates, Shannon M; Douxfils, Jonathan; Favaloro, Emmanuel J; Gouin-Thibault, Isabelle; Guillermo, Cecilia; Kawai, Yohko; Lindhoff-Last, Edelgard; Kitchen, Steve
2018-03-01
This guidance document was prepared on behalf of the International Council for Standardization in Haematology (ICSH) for providing haemostasis-related guidance documents for clinical laboratories. This inaugural coagulation ICSH document was developed by an ad hoc committee, comprised of international clinical and laboratory direct acting oral anticoagulant (DOAC) experts. The committee developed consensus recommendations for laboratory measurement of DOACs (dabigatran, rivaroxaban, apixaban and edoxaban), which would be germane for laboratories assessing DOAC anticoagulation. This guidance document addresses all phases of laboratory DOAC measurements, including pre-analytical (e.g. preferred time sample collection, preferred sample type, sample stability), analytical (gold standard method, screening and quantifying methods) and post analytical (e.g. reporting units, quality assurance). The committee addressed the use and limitations of screening tests such as prothrombin time, activated partial thromboplastin time as well as viscoelastic measurements of clotting blood and point of care methods. Additionally, the committee provided recommendations for the proper validation or verification of performance of laboratory assays prior to implementation for clinical use, and external quality assurance to provide continuous assessment of testing and reporting method. Schattauer GmbH Stuttgart.
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Evaluation of analytical errors in a clinical chemistry laboratory: a 3 year experience.
Sakyi, As; Laing, Ef; Ephraim, Rk; Asibey, Of; Sadique, Ok
2015-01-01
Proficient laboratory service is the cornerstone of modern healthcare systems and has an impact on over 70% of medical decisions on admission, discharge, and medications. In recent years, there is an increasing awareness of the importance of errors in laboratory practice and their possible negative impact on patient outcomes. We retrospectively analyzed data spanning a period of 3 years on analytical errors observed in our laboratory. The data covered errors over the whole testing cycle including pre-, intra-, and post-analytical phases and discussed strategies pertinent to our settings to minimize their occurrence. We described the occurrence of pre-analytical, analytical and post-analytical errors observed at the Komfo Anokye Teaching Hospital clinical biochemistry laboratory during a 3-year period from January, 2010 to December, 2012. Data were analyzed with Graph Pad Prism 5(GraphPad Software Inc. CA USA). A total of 589,510 tests was performed on 188,503 outpatients and hospitalized patients. The overall error rate for the 3 years was 4.7% (27,520/58,950). Pre-analytical, analytical and post-analytical errors contributed 3.7% (2210/58,950), 0.1% (108/58,950), and 0.9% (512/58,950), respectively. The number of tests reduced significantly over the 3-year period, but this did not correspond with a reduction in the overall error rate (P = 0.90) along with the years. Analytical errors are embedded within our total process setup especially pre-analytical and post-analytical phases. Strategic measures including quality assessment programs for staff involved in pre-analytical processes should be intensified.
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External quality assessment of urine particle identification: a Northern European experience.
Kouri, Timo T; Makkonen, Pirjo
2015-11-01
External quality assessment (EQA) schemes for urinalysis have been provided by Labquality Ltd, the publicly owned EQA service provider in Finland, since the 1980s. In 2014, the scheme on urine particle identification had 329 participating laboratories, out of which 60% from 19 countries were outside Finland. Each of the four annual web-based rounds were distributed with four Sternheimer-stained images from a single patient sample, as viewed both by bright-field and phase-contrast optics. Participants reported classified categories either at the basic or at the advanced level. Participating laboratories received assessment of their analytical performance as compared to their peers, including reflections from clinical data and preanalytical detail of the specimen. In general, reporting of basic urine particles succeeded in the eight schemes during the years 2013-2014 as follows: red blood cells 82%-92%, white blood cells 82%-97%, squamous epithelial cells 92%-98%, casts 84%-94%, and small epithelial cells 73%-83% (minimum and maximum of expected or accepted reports). This basic level of differentiation is used in routine laboratory reports, or as verification of results produced by automated instruments. Considerable effort is needed to standardise national procedures and reporting formats, in order to improve the shown figures internationally. Future technologies may help to alleviate limitations created by single digital images. Despite improvements, degenerating cells and casts always exhibit intermediate forms creating disputable classifications. That is why assessment of performance should encompass justified acceptable categories into the assessed outcomes. Preanalytical and clinical detail provide essential added value to morphological findings.
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42 CFR 493.1241 - Standard: Test request.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 42 Public Health 5 2014-10-01 2014-10-01 false Standard: Test request. 493.1241 Section 493.1241 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Quality System for Nonwaived Testing Preanalytic Systems § 493.1241 Standard: Test request...
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A Six Sigma Trial For Reduction of Error Rates in Pathology Laboratory.
Tosuner, Zeynep; Gücin, Zühal; Kiran, Tuğçe; Büyükpinarbaşili, Nur; Turna, Seval; Taşkiran, Olcay; Arici, Dilek Sema
2016-01-01
A major target of quality assurance is the minimization of error rates in order to enhance patient safety. Six Sigma is a method targeting zero error (3.4 errors per million events) used in industry. The five main principles of Six Sigma are defining, measuring, analysis, improvement and control. Using this methodology, the causes of errors can be examined and process improvement strategies can be identified. The aim of our study was to evaluate the utility of Six Sigma methodology in error reduction in our pathology laboratory. The errors encountered between April 2014 and April 2015 were recorded by the pathology personnel. Error follow-up forms were examined by the quality control supervisor, administrative supervisor and the head of the department. Using Six Sigma methodology, the rate of errors was measured monthly and the distribution of errors at the preanalytic, analytic and postanalytical phases was analysed. Improvement strategies were reclaimed in the monthly intradepartmental meetings and the control of the units with high error rates was provided. Fifty-six (52.4%) of 107 recorded errors in total were at the pre-analytic phase. Forty-five errors (42%) were recorded as analytical and 6 errors (5.6%) as post-analytical. Two of the 45 errors were major irrevocable errors. The error rate was 6.8 per million in the first half of the year and 1.3 per million in the second half, decreasing by 79.77%. The Six Sigma trial in our pathology laboratory provided the reduction of the error rates mainly in the pre-analytic and analytic phases.
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Findeisen, Peter; Peccerella, Teresa; Post, Stefan; Wenz, Frederik; Neumaier, Michael
2008-04-01
Serum is a difficult matrix for the identification of biomarkers by mass spectrometry (MS). This is due to high-abundance proteins and their complex processing by a multitude of endogenous proteases making rigorous standardisation difficult. Here, we have investigated the use of defined exogenous reporter peptides as substrates for disease-specific proteases with respect to improved standardisation and disease classification accuracy. A recombinant N-terminal fragment of the Adenomatous Polyposis Coli (APC) protein was digested with trypsin to yield a peptide mixture for subsequent Reporter Peptide Spiking (RPS) of serum. Different preanalytical handling of serum samples was simulated by storage of serum samples for up to 6 h at ambient temperature, followed by RPS, further incubation under standardised conditions and testing for stability of protease-generated MS profiles. To demonstrate the superior classification accuracy achieved by RPS, a pilot profiling experiment was performed using serum specimens from pancreatic cancer patients (n = 50) and healthy controls (n = 50). After RPS six different peak categories could be defined, two of which (categories C and D) are modulated by endogenous proteases. These latter are relevant for improved classification accuracy as shown by enhanced disease-specific classification from 78% to 87% in unspiked and spiked samples, respectively. Peaks of these categories presented with unchanged signal intensities regardless of preanalytical conditions. The use of RPS generally improved the signal intensities of protease-generated peptide peaks. RPS circumvents preanalytical variabilities and improves classification accuracies. Our approach will be helpful to introduce MS-based proteomic profiling into routine laboratory testing.
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Gunn-Christie, Rebekah G; Flatland, Bente; Friedrichs, Kristen R; Szladovits, Balazs; Harr, Kendal E; Ruotsalo, Kristiina; Knoll, Joyce S; Wamsley, Heather L; Freeman, Kathy P
2012-03-01
In December 2009, the American Society for Veterinary Clinical Pathology (ASVCP) Quality Assurance and Laboratory Standards committee published the updated and peer-reviewed ASVCP Quality Assurance Guidelines on the Society's website. These guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports: (1) general analytical factors for veterinary laboratory performance and comparisons; (2) hematology, hemostasis, and crossmatching; and (3) clinical chemistry, cytology, and urinalysis. This particular report is one of 3 reports and documents recommendations for control of preanalytical, analytical, and postanalytical factors related to urinalysis, cytology, and clinical chemistry in veterinary laboratories and is adapted from sections 1.1 and 2.2 (clinical chemistry), 1.3 and 2.5 (urinalysis), 1.4 and 2.6 (cytology), and 3 (postanalytical factors important in veterinary clinical pathology) of these guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimal guidelines for quality assurance and quality control for veterinary laboratory testing and a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts. © 2012 American Society for Veterinary Clinical Pathology.
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Vap, Linda M; Harr, Kendal E; Arnold, Jill E; Freeman, Kathleen P; Getzy, Karen; Lester, Sally; Friedrichs, Kristen R
2012-03-01
In December 2009, the American Society for Veterinary Clinical Pathology (ASVCP) Quality Assurance and Laboratory Standards committee published the updated and peer-reviewed ASVCP Quality Assurance Guidelines on the Society's website. These guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports: (1) general analytical factors for veterinary laboratory performance and comparisons; (2) hematology, hemostasis, and crossmatching; and (3) clinical chemistry, cytology, and urinalysis. This particular report is one of 3 reports and provides recommendations for control of preanalytical and analytical factors related to hematology for mammalian and nonmammalian species, hemostasis testing, and crossmatching and is adapted from sections 1.1 and 2.3 (mammalian hematology), 1.2 and 2.4 (nonmammalian hematology), 1.5 and 2.7 (hemostasis testing), and 1.6 and 2.8 (crossmatching) of the complete guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimal guidelines for quality assurance and quality control for veterinary laboratory testing and a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts. © 2012 American Society for Veterinary Clinical Pathology.
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Evaluation of Analytical Errors in a Clinical Chemistry Laboratory: A 3 Year Experience
Sakyi, AS; Laing, EF; Ephraim, RK; Asibey, OF; Sadique, OK
2015-01-01
Background: Proficient laboratory service is the cornerstone of modern healthcare systems and has an impact on over 70% of medical decisions on admission, discharge, and medications. In recent years, there is an increasing awareness of the importance of errors in laboratory practice and their possible negative impact on patient outcomes. Aim: We retrospectively analyzed data spanning a period of 3 years on analytical errors observed in our laboratory. The data covered errors over the whole testing cycle including pre-, intra-, and post-analytical phases and discussed strategies pertinent to our settings to minimize their occurrence. Materials and Methods: We described the occurrence of pre-analytical, analytical and post-analytical errors observed at the Komfo Anokye Teaching Hospital clinical biochemistry laboratory during a 3-year period from January, 2010 to December, 2012. Data were analyzed with Graph Pad Prism 5(GraphPad Software Inc. CA USA). Results: A total of 589,510 tests was performed on 188,503 outpatients and hospitalized patients. The overall error rate for the 3 years was 4.7% (27,520/58,950). Pre-analytical, analytical and post-analytical errors contributed 3.7% (2210/58,950), 0.1% (108/58,950), and 0.9% (512/58,950), respectively. The number of tests reduced significantly over the 3-year period, but this did not correspond with a reduction in the overall error rate (P = 0.90) along with the years. Conclusion: Analytical errors are embedded within our total process setup especially pre-analytical and post-analytical phases. Strategic measures including quality assessment programs for staff involved in pre-analytical processes should be intensified. PMID:25745569
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Post-analytical Issues in Hemostasis and Thrombosis Testing.
Favaloro, Emmanuel J; Lippi, Giuseppe
2017-01-01
Analytical concerns within hemostasis and thrombosis testing are continuously decreasing. This is essentially attributable to modern instrumentation, improvements in test performance and reliability, as well as the application of appropriate internal quality control and external quality assurance measures. Pre-analytical issues are also being dealt with in some newer instrumentation, which are able to detect hemolysis, icteria and lipemia, and, in some cases, other issues related to sample collection such as tube under-filling. Post-analytical issues are generally related to appropriate reporting and interpretation of test results, and these are the focus of the current overview, which provides a brief description of these events, as well as guidance for their prevention or minimization. In particular, we propose several strategies for improved post-analytical reporting of hemostasis assays and advise that this may provide the final opportunity to prevent serious clinical errors in diagnosis.
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Sherman, L A
1999-07-01
Outcomes data in medicine can be limited by subjective methodologic issues such as poor selection of end points and use of nonvalidated systems for quality adjustment. Blood transfusion analyses are further complicated by the fact that transfusion seldom is primary therapy but is usually supportive or adjunctive. Thus, much of the outcome data in transfusion medicine are either unavailable or in one of two areas. The first area is prevention of bad sequelae of various cytopenias or factor deficiencies. The second is decreasing adverse effects of transfusion itself. A different useful area for outcome and root cause approaches in individual institutions is examining preanalytical and postanalytical processes of their own. Examples are sample labeling accuracy, quality and timeliness of blood suppliers, internal delivery processes and times, and product wastage. Use review can be changed to real time from retrospective time. By reducing complaints about service to objective data, realistic change can be made in internal and external processes.
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Technical pre-analytical effects on the clinical biochemistry of Atlantic salmon (Salmo salar L.).
Braceland, M; Houston, K; Ashby, A; Matthews, C; Haining, H; Rodger, H; Eckersall, P D
2017-01-01
Clinical biochemistry has long been utilized in human and veterinary medicine as a vital diagnostic tool, but despite occasional studies showing its usefulness in monitoring health status in Atlantic salmon (Salmo salar L.), it has not yet been widely utilized within the aquaculture industry. This is due, in part, to a lack of an agreed protocol for collection and processing of blood prior to analysis. Moreover, while the analytical phase of clinical biochemistry is well controlled, there is a growing understanding that technical pre-analytical variables can influence analyte concentrations or activities. In addition, post-analytical interpretation of treatment effects is variable in the literature, thus making the true effect of sample treatment hard to evaluate. Therefore, a number of pre-analytical treatments have been investigated to examine their effect on analyte concentrations and activities. In addition, reference ranges for salmon plasma biochemical analytes have been established to inform veterinary practitioners and the aquaculture industry of the importance of clinical biochemistry in health and disease monitoring. Furthermore, a standardized protocol for blood collection has been proposed. © 2016 The Authors Journal of Fish Diseases Published by John Wiley & Sons Ltd.
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Establishment of Protocols for Global Metabolomics by LC-MS for Biomarker Discovery.
Saigusa, Daisuke; Okamura, Yasunobu; Motoike, Ikuko N; Katoh, Yasutake; Kurosawa, Yasuhiro; Saijyo, Reina; Koshiba, Seizo; Yasuda, Jun; Motohashi, Hozumi; Sugawara, Junichi; Tanabe, Osamu; Kinoshita, Kengo; Yamamoto, Masayuki
2016-01-01
Metabolomics is a promising avenue for biomarker discovery. Although the quality of metabolomic analyses, especially global metabolomics (G-Met) using mass spectrometry (MS), largely depends on the instrumentation, potential bottlenecks still exist at several basic levels in the metabolomics workflow. Therefore, we established a precise protocol initially for the G-Met analyses of human blood plasma to overcome some these difficulties. In our protocol, samples are deproteinized in a 96-well plate using an automated liquid-handling system, and conducted either using a UHPLC-QTOF/MS system equipped with a reverse phase column or a LC-FTMS system equipped with a normal phase column. A normalization protocol of G-Met data was also developed to compensate for intra- and inter-batch differences, and the variations were significantly reduced along with our normalization, especially for the UHPLC-QTOF/MS data with a C18 reverse-phase column for positive ions. Secondly, we examined the changes in metabolomic profiles caused by the storage of EDTA-blood specimens to identify quality markers for the evaluation of the specimens' pre-analytical conditions. Forty quality markers, including lysophospholipids, dipeptides, fatty acids, succinic acid, amino acids, glucose, and uric acid were identified by G-Met for the evaluation of plasma sample quality and established the equation of calculating the quality score. We applied our quality markers to a small-scale study to evaluate the quality of clinical samples. The G-Met protocols and quality markers established here should prove useful for the discovery and development of biomarkers for a wider range of diseases.
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Hemolysis from a nurses' standpoint--survey from four Croatian hospitals.
Dorotić, Adrijana; Antončić, Dragana; Biljak, Vanja Radišić; Nedić, Dara; Beletić, Andjelo
2015-01-01
Hemolysis can occur during sample collection, handling and transport. It is more frequent when the non-laboratory staff performs sampling. The aim of this study was to assess nurses' knowledge on the causes of hemolysis and consequential impact on the laboratory tests results. Additionally, the differences in knowledge, related to work experience, professional degree and previous education about hemolysis were explored. An anonymus survey, containing 11 questions on demographics, causes of hemolysis, its impact on biochemical parameters and nurses' attitude towards additional education in preanalytics, was conducted in four Croatian hospitals. The answers were compared by Chi-squared and Fischer exact test. In total, 562 survey results were collected. Majority of nurses declared familiarity with the term "hemolysis" (99.6%). There were 77% of correct answers regarding questions about the causes of hemolysis, but only 50% when it comes to questions about interference in biochemical tests. The percentage of correct answers about causes was significantly lower (P=0.029) among more experienced nurses, and higher (P=0.027) in those with higher professional degree, while influence of previous education was not significant. Also, higher percentage of correct answers about interferences was encountered in nurses with longer work experience (P=0.039). More than 70% of nurses declared that additional education about preanalytical factors would be beneficial. Croatian nurses are familiar with the definition of hemolysis, but a lack of knowledge about causes and influence on laboratory test results is evident. Nurses are eager to improve their knowledge in this field of preanalytical phase.
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Mody, M; Lazarus, A H; Semple, J W; Freedman, J
1999-06-01
Accurate assessment of in vivo or in vitro platelet activation requires optimal preanalytical conditions to prevent artefactual in vitro activation of the platelets. The choice of anticoagulant is one of the critical preanalytical conditions as anticoagulants exert different effects on the activation of platelets ex vivo. We tested the effectiveness of Diatube-H (also known as CTAD; sodium citrate, theophylline, adenosine and dipyridamole) and citrate vacutainer tubes in preventing artefactual activation of platelets and preserving functional reserve. Platelet surface expression of the CD62P (reflecting alpha granule release), CD63 (reflecting lysosomal release) and modulation of normal platelet membrane glycoproteins CD41a and CD42b, were measured in whole blood and in isolated platelets immediately after collection and at 6, 24 and 48 h after venipuncture. Samples taken into Diatube-H showed less spontaneous platelet activation than did those taken into citrate. To measure in vitro platelet functional reserve, thrombin was added as agonist to blood stored for varying periods up to 48 h. Although Diatube-H suppressed in vitro platelet activation for up to 4 h, in samples kept for 6-24 h before thrombin addition, the inhibitory effect was lost and platelets responded fully to agonist activation. Hence, Diatube-H preserved platelets and allowed for measurement of in vivo platelet activation as well as thrombin-induced in vitro platelet activation after 6-24 h, in both whole blood and isolated platelets.
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Gupta, Veer; Henriksen, Kim; Edwards, Melissa; Jeromin, Andreas; Lista, Simone; Bazenet, Chantal; Soares, Holly; Lovestone, Simon; Hampel, Harald; Montine, Thomas; Blennow, Kaj; Foroud, Tatiana; Carrillo, Maria; Graff-Radford, Neill; Laske, Christoph; Breteler, Monique; Shaw, Leslie; Trojanowski, John Q.; Schupf, Nicole; Rissman, Robert A.; Fagan, Anne M.; Oberoi, Pankaj; Umek, Robert; Weiner, Michael W.; Grammas, Paula; Posner, Holly; Martins, Ralph
2015-01-01
The lack of readily available biomarkers is a significant hindrance towards progressing to effective therapeutic and preventative strategies for Alzheimer’s disease (AD). Blood-based biomarkers have potential to overcome access and cost barriers and greatly facilitate advanced neuroimaging and cerebrospinal fluid biomarker approaches. Despite the fact that preanalytical processing is the largest source of variability in laboratory testing, there are no currently available standardized preanalytical guidelines. The current international working group provides the initial starting point for such guidelines for standardized operating procedures (SOPs). It is anticipated that these guidelines will be updated as additional research findings become available. The statement provides (1) a synopsis of selected preanalytical methods utilized in many international AD cohort studies, (2) initial draft guidelines/SOPs for preanalytical methods, and (3) a list of required methodological information and protocols to be made available for publications in the field in order to foster cross-validation across cohorts and laboratories. PMID:25282381
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Romero, Adolfo; Cobos, Andrés; Gómez, Juan; Muñoz, Manuel
2012-01-18
The presence of pre-analytical errors (PE) is a usual contingency in laboratories. The incidence may increase where it is difficult to control that period, as it is the case with samples sent from primary care (PC) to clinical reference laboratory. Detection of a large number of PE in PC samples in our Institution led to the development and implementation of preventive strategies. The first of these has been the realization of a cycle of educational sessions for PC nurses, followed by the evaluation of their impact on PE number. The incidence of PE was assessed in two periods, before (October-November 2007) and after (October-November, 2009) the implementation of educational sessions. Eleven PC centers in the urban area and 17 in the rural area participated. In the urban area, samples were withdrawn by any PC nurse; in the rural area, samples were obtained by the patient's reference nurse. The types of analyzed PE included missed sample (MS), hemolyzed sample (HS), coagulated sample (CS), incorrect sample (ISV) and others (OPE), such as lipemic or icteric serum or plasma. In the former period, we received 52,669 blood samples and 18,852 urine samples, detecting 3885 (7.5%) and 1567 (8.3%) PEs, respectively. After the educational intervention, there were 52,659 and 19,048 samples with 5057 (9.6%) and 1.256 (6.5%) PEs, respectively (p<0.001). According to the type of PE, the incidents compared before and after compared incidences were: MS, 4.8% vs. 3.8%, p<0.001; HS, 1.97% vs. 3.9%, p<0.001; CS, 0.54% vs. 0.25%, p<0.001; ISV, 0.15% vs. 0.19% p=0.08; and OPE, 0.3% vs. 0.42%, p<0.001. Surprisingly the PE incidence increased after the educational intervention, although it should be noted that it was primarily due to the increase of HS, as the other EP incidence decreased (MS and CS) or remained unchanged (ISV). This seems to indicate the need for a comprehensive approach to reduce the incidence of errors in the pre-analytical period, as one stage interventions do not seem to be effective enough. Copyright © 2011 Elsevier B.V. All rights reserved.
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Preanalytical Nonconformity Management Regarding Primary Tube Mixing in Brazil.
Lima-Oliveira, Gabriel; Cesare Guidi, Gian; Guimaraes, Andre Valpassos Pacifici; Abol Correa, Jose; Lippi, Giuseppe
2017-01-01
The multifaceted clinical laboratory process is divided in three essential phases: the preanalytical, analytical and postanalytical phase. Problems emerging from the preanalytical phase are responsible for more than 60% of laboratory errors. This report is aimed at highlighting and discussing nonconformity (e.g., nonstandardized procedures) in primary blood tube mixing immediately after blood collection by venipuncture with evacuated tube systems. From January 2015 to December 2015, fifty different laboratory quality managers from Brazil were contacted to request their internal audit reports on nonconformity regarding primary blood tube mixing immediately after blood collection by venipuncture performed using evacuated tube systems. A minority of internal audits (i.e., 4%) concluded that evacuated blood tubes were not accurately mixed after collection, whereas more than half of them reported that evacuated blood tubes were vigorously mixed immediately after collection, thus magnifying the risk of producing spurious hemolysis. Despite the vast ma jority of centers declaring that evacuated blood tubes were mixed gently and carefully, the overall number of inversions was found to be different from that recommended by the manufacturer. Since the turbulence generated by the standard vacuum pressure inside the primary evacuated tubes seems to be sufficient for providing solubilization, mixing and stabilization between additives and blood during venipuncture, avoidance of primary tube mixing probably does not introduce a major bias in tests results and may not be considered a nonconformity during audits for accreditation.
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Hemolysis from a nurses’ standpoint – survey from four Croatian hospitals
Dorotić, Adrijana; Antončić, Dragana; Biljak, Vanja Radišić; Nedić, Dara; Beletić, Andjelo
2015-01-01
Introduction Hemolysis can occur during sample collection, handling and transport. It is more frequent when the non-laboratory staff performs sampling. The aim of this study was to assess nurses’ knowledge on the causes of hemolysis and consequential impact on the laboratory tests results. Additionally, the differences in knowledge, related to work experience, professional degree and previous education about hemolysis were explored. Materials and methods An anonymus survey, containing 11 questions on demographics, causes of hemolysis, its impact on biochemical parameters and nurses’ attitude towards additional education in preanalytics, was conducted in four Croatian hospitals. The answers were compared by Chi-squared and Fischer exact test. Results In total, 562 survey results were collected. Majority of nurses declared familiarity with the term “hemolysis” (99.6%). There were 77% of correct answers regarding questions about the causes of hemolysis, but only 50% when it comes to questions about interference in biochemical tests. The percentage of correct answers about causes was significantly lower (P = 0.029) among more experienced nurses, and higher (P = 0.027) in those with higher professional degree, while influence of previous education was not significant. Also, higher percentage of correct answers about interferences was encountered in nurses with longer work experience (P = 0.039). More than 70% of nurses declared that additional education about preanalytical factors would be beneficial. Conclusion Croatian nurses are familiar with the definition of hemolysis, but a lack of knowledge about causes and influence on laboratory test results is evident. Nurses are eager to improve their knowledge in this field of preanalytical phase. PMID:26525069
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Garcia, Jessica; Dusserre, Eric; Cheynet, Valérie; Bringuier, Pierre Paul; Brengle-Pesce, Karen; Wozny, Anne-Sophie; Rodriguez-Lafrasse, Claire; Freyer, Gilles; Brevet, Marie; Payen, Léa; Couraud, Sébastien
2017-01-01
Non invasive somatic detection assays are suitable for repetitive tumor characterization or for detecting the appearance of somatic resistance during lung cancer. Molecular diagnosis based on circulating free DNA (cfDNA) offers the opportunity to track the genomic evolution of the tumor, and was chosen to assess the molecular profile of several EGFR alterations, including deletions in exon 19 (delEX19), the L858R substitution on exon 21 and the EGFR resistance mutation T790M on exon 20. Our study aimed at determining optimal pre-analytical conditions and EGFR mutation detection assays for analyzing cfDNA using the picoliter-droplet digital polymerase chain reaction (ddPCR) assay. Within the framework of the CIRCAN project set-up at the Lyon University Hospital, plasma samples were collected to establish a pre-analytical and analytical workflow of cfDNA analysis. We evaluated all of the steps from blood sampling to mutation detection output, including shipping conditions (4H versus 24H in EDTA tubes), the reproducibility of cfDNA extraction, the specificity/sensitivity of ddPCR (using external controls), and the comparison of different PCR assays for the detection of the three most important EGFR hotspots, which highlighted the increased sensitivity of our in-house primers/probes. Hence, we have described a new protocol facilitating the molecular detection of somatic mutations in cancer patients from liquid biopsies, improving their diagnosis and introducing a less traumatic monitoring system during tumor progression. PMID:29152135
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Need for gender-specific pre-analytical testing: the dark side of the moon in laboratory testing.
Franconi, Flavia; Rosano, Giuseppe; Campesi, Ilaria
2015-01-20
Many international organisations encourage studies in a sex-gender perspective. However, research with a gender perspective presents a high degree of complexity, and the inclusion of sex-gender variable in experiments presents many methodological questions, the majority of which are still neglected. Overcoming these issues is fundamental to avoid erroneous results. Here, pre-analytical aspects of the research, such as study design, choice of utilised specimens, sample collection and processing, animal models of diseases, and the observer's role, are discussed. Artefacts in this stage of research could affect the predictive value of all analyses. Furthermore, the standardisation of research subjects according to their lifestyles and, if female, to their life phase and menses or oestrous cycle, is urgent to harmonise research worldwide. A sex-gender-specific attention to pre-analytical aspects could produce a decrease in the time for translation from the bench to bedside. Furthermore, sex-gender-specific pre-clinical pharmacological testing will enable adequate assessment of pharmacokinetic and pharmacodynamic actions of drugs and will enable, where appropriate, an adequate gender-specific clinical development plan. Therefore, sex-gender-specific pre-clinical research will increase the gender equity of care and will produce more evidence-based medicine. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
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Mistakes in a stat laboratory: types and frequency.
Plebani, M; Carraro, P
1997-08-01
Application of Total Quality Management concepts to laboratory testing requires that the total process, including preanalytical and postanalytical phases, be managed so as to reduce or, ideally, eliminate all defects within the process itself. Indeed a "mistake" can be defined as any defect during the entire testing process, from ordering tests to reporting results. We evaluated the frequency and types of mistakes found in the "stat" section of the Department of Laboratory Medicine of the University-Hospital of Padova by monitoring four different departments (internal medicine, nephrology, surgery, and intensive care unit) for 3 months. Among a total of 40490 analyses, we identified 189 laboratory mistakes, a relative frequency of 0.47%. The distribution of mistakes was: preanalytical 68.2%, analytical 13.3%, and postanalytical 18.5%. Most of the laboratory mistakes (74%) did not affect patients' outcome. However, in 37 patients (19%), laboratory mistakes were associated with further inappropriate investigations, thus resulting in an unjustifiable increase in costs. Moreover, in 12 patients (6.4%) laboratory mistakes were associated with inappropriate care or inappropriate modification of therapy. The promotion of quality control and continuous improvement of the total testing process, including pre- and postanalytical phases, seems to be a prerequisite for an effective laboratory service.
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[Current aspects of the definition and diagnosis of sepsis and antibiotic resistance].
Brunkhorst, Frank M; Gastmeier, Petra; Abu Sin, Muna
2018-05-01
Hospital mortality of patients with secondary sepsis remains high at around 40%. Because of the methodological deficiencies of the definitions used so far, valid epidemiological data on secondary sepsis that allow for national and international comparisons are lacking. Since 2016, new clinical diagnostic tools that are also suitable for sepsis screening outside of intensive care units have been available. To counteract the high mortality of nosocomial sepsis, new approaches to the early identification of at-risk patients are needed. An adequate blood culture sampling rate and a high preanalytical quality should be established as a basis for quality assurance, especially in the field of nosocomial bloodstream infections; otherwise, there is a risk of surveillance bias. Data from laboratory-based antibiotic resistance surveillance on MRSA in blood culture isolates have shown a downward trend over the last 4 years. In Gram-negative pathogens, a relatively stable resistance situation has been observed over this period for many of the pathogen-antibiotic combinations.
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A review of blood sample handling and pre-processing for metabolomics studies.
Hernandes, Vinicius Veri; Barbas, Coral; Dudzik, Danuta
2017-09-01
Metabolomics has been found to be applicable to a wide range of clinical studies, bringing a new era for improving clinical diagnostics, early disease detection, therapy prediction and treatment efficiency monitoring. A major challenge in metabolomics, particularly untargeted studies, is the extremely diverse and complex nature of biological specimens. Despite great advances in the field there still exist fundamental needs for considering pre-analytical variability that can introduce bias to the subsequent analytical process and decrease the reliability of the results and moreover confound final research outcomes. Many researchers are mainly focused on the instrumental aspects of the biomarker discovery process, and sample related variables sometimes seem to be overlooked. To bridge the gap, critical information and standardized protocols regarding experimental design and sample handling and pre-processing are highly desired. Characterization of a range variation among sample collection methods is necessary to prevent results misinterpretation and to ensure that observed differences are not due to an experimental bias caused by inconsistencies in sample processing. Herein, a systematic discussion of pre-analytical variables affecting metabolomics studies based on blood derived samples is performed. Furthermore, we provide a set of recommendations concerning experimental design, collection, pre-processing procedures and storage conditions as a practical review that can guide and serve for the standardization of protocols and reduction of undesirable variation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Kühn, A; Nieters, A; Köttgen, A; Goek, O N; Michels, K; Nöthlings, U; Jacobs, G; Meisinger, C; Pessler, F; Akmatov, M F; Kühnisch, J; Moebus, S; Glocker, E; Naus, S; Keimling, M; Leitzmann, M; Linseisen, J; Sarioglu, H; von Toerne, C; Hauck, S M; Wallaschofski, H; Wichmann, H E; Illig, Thomas
2014-11-01
The German National Cohort (GNC) is designed to address research questions concerning a wide range of possible causes of major chronic diseases (e.g. cancer, diabetes, infectious, allergic, neurologic and cardiovascular diseases) as well as to identify risk factors and prognostic biomarkers for early diagnosis and prevention of these diseases. The collection of biomaterials in combination with extensive information from questionnaires and medical examinations represents one of the central study components. In two pretest studies of the German National Cohort conducted between 2011 and 2013, a range of biomaterials from a defined number of participants was collected. Ten study centres were involved in pretest 1 and 18 study centres were involved in pretest 2. Standard operation procedures (SOP) were developed and evaluated to minimize pre-analytical artefacts during biosample collection. Within the pretest studies different aspects concerning feasibility of sample collection/preparation [pretest 1 (a)] and quality control of biomarkers and proteome analyses were investigated [pretest 1 (b), (c)]. Additionally, recruitment of study participants for specific projects and examination procedures of all study centres in a defined time period according to common standards as well as transportation and decentralized storage of biological samples were tested (pretest 2). These analyses will serve as the basis for the biomaterial collection in the main study of the GNC starting in 2014. Participants, randomly chosen from the population (n = 1000 subjects recruited at ten study sites in pretest 1) were asked to donate blood, urine, saliva and stool samples. Additionally, nasal and oropharyngeal swabs were collected at the study sites and nasal swabs were collected by the participants at home. SOPs for sample collection, preparation, storage and transportation were developed and adopted for pretest 2. In pretest 2, 18 study sites (n = 599 subjects) collected biomaterials mostly identical to pretest 1. Biomarker analyses to test the quality of the biomaterials were performed. In pretest 1 and 2, it was feasible to collect all biomaterials from nearly all invited participants without major problems. The mean response rate of the subjects was 95 %. As one important result we found for example that after blood draw the cellular fraction should be separated from the plasma and serum fractions during the first hour with no significant variation for up to 6 h at 4 ℃ for all analysed biomarkers. Moreover, quality control of samples using a proteomics approach showed no significant clustering of proteins according to different storage conditions. All developed SOPs were validated for use in the main study after some adaptation and modification. Additionally, electronic and paper documentation sheets were developed and tested to record time stamps, volumes, freezing times, and aliquot numbers of the collected biomaterials. The collection of the biomaterials was feasible without major problems at all participating study sites. However, the processing times were in some cases too long. To avoid pre-analytical artefacts in sample collection, appropriate standardisation among the study sites is necessary. To achieve this, blood and urine collection will have to be adapted to specific conditions of usage of liquid handling robots, which will be available at all participating study centres in the main study of the GNC. Strict compliance with the SOPs, thorough training of the staff and accurate documentation are mandatory to obtain high sample quality for later analyses. The so obtained biomaterials represent a valuable resource for research on infectious and other common complex diseases in the GNC.
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Reproducibility studies for experimental epitope detection in macrophages (EDIM).
Japink, Dennis; Nap, Marius; Sosef, Meindert N; Nelemans, Patty J; Coy, Johannes F; Beets, Geerard; von Meyenfeldt, Maarten F; Leers, Math P G
2014-05-01
We have recently described epitope detection in macrophages (EDIM) by flow cytometry. This is a promising tool for the diagnosis and follow-up of malignancies. However, biological and technical validation is warranted before clinical applicability can be explored. The pre-analytic and analytic phases were investigated. Five different aspects were assessed: blood sample stability, intra-individual variability in healthy persons, intra-assay variation, inter-assay variation and assay transferability. The post-analytic phase was already partly standardized and described in an earlier study. The outcomes in the pre-analytic phase showed that samples are stable for 24h after venipuncture. Biological variation over time was similar to that of serum tumor marker assays; each patient has a baseline value. Intra-assay variation showed good reproducibility, while inter-assay variation showed reproducibility similar to that of to established serum tumor marker assays. Furthermore, the assay showed excellent transferability between analyzers. Under optimal analytic conditions the EDIM method is technically stable, reproducible and transferable. Biological variation over time needs further assessment in future work. Copyright © 2014 Elsevier B.V. All rights reserved.
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Pre-analytical method for NMR-based grape metabolic fingerprinting and chemometrics.
Ali, Kashif; Maltese, Federica; Fortes, Ana Margarida; Pais, Maria Salomé; Verpoorte, Robert; Choi, Young Hae
2011-10-10
Although metabolomics aims at profiling all the metabolites in organisms, data quality is quite dependent on the pre-analytical methods employed. In order to evaluate current methods, different pre-analytical methods were compared and used for the metabolic profiling of grapevine as a model plant. Five grape cultivars from Portugal in combination with chemometrics were analyzed in this study. A common extraction method with deuterated water and methanol was found effective in the case of amino acids, organic acids, and sugars. For secondary metabolites like phenolics, solid phase extraction with C-18 cartridges showed good results. Principal component analysis, in combination with NMR spectroscopy, was applied and showed clear distinction among the cultivars. Primary metabolites such as choline, sucrose, and leucine were found discriminating for 'Alvarinho', while elevated levels of alanine, valine, and acetate were found in 'Arinto' (white varieties). Among the red cultivars, higher signals for citrate and GABA in 'Touriga Nacional', succinate and fumarate in 'Aragonês', and malate, ascorbate, fructose and glucose in 'Trincadeira', were observed. Based on the phenolic profile, 'Arinto' was found with higher levels of phenolics as compared to 'Alvarinho'. 'Trincadeira' showed lowest phenolics content while higher levels of flavonoids and phenylpropanoids were found in 'Aragonês' and 'Touriga Nacional', respectively. It is shown that the metabolite composition of the extract is highly affected by the extraction procedure and this consideration has to be taken in account for metabolomics studies. Copyright © 2011 Elsevier B.V. All rights reserved.
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Metabolomic Quality Assessment of EDTA Plasma and Serum Samples.
Malm, Linus; Tybring, Gunnel; Moritz, Thomas; Landin, Britta; Galli, Joakim
2016-10-01
Handling and processing of blood can significantly alter the molecular composition and consistency of biobank samples and can have a major impact on the identification of biomarkers. It is thus crucial to identify tools to determine the quality of samples to be used in biomarker discovery studies. In this study, a non-targeted gas chromatography/time-of-flight mass spectrometry (GC-TOFMS) metabolomic strategy was used with the aim of identifying quality markers for serum and plasma biobank collections lacking proper documentation of preanalytical handling. The effect of postcentrifugation delay was examined in serum stored in tubes with gel separation plugs and ethylenediaminetetraacetic acid (EDTA) plasma in tubes with or without gel separation plugs. The change in metabolic pattern was negligible in all sample types processed within 3 hours after centrifugation regardless of whether the samples were kept at 4°C or 22°C. After 8 and 24 hours postcentrifugation delay before aliquoting, there was a pronounced increase in the number of affected metabolites, as well as in the magnitude of the observed changes. No protective effect on the metabolites was observed in gel-separated EDTA plasma samples. In a separate series of experiments, lactate and glucose levels were determined in plasma to estimate the effect of precentrifugation delay. This separate experiment indicates that the lactate to glucose ratio may serve as a marker to identify samples with delayed time to centrifugation. Although our data from the untargeted GC-TOFMS analysis did not identify any specific markers, we conclude that plasma and serum metabolic profiles remain quite stable when plasma and serum are centrifuged and separated from the blood cells within 3 hours.
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Sédille-Mostafaie, Nazanin; Engler, Hanna; Lutz, Susanne; Korte, Wolfgang
2013-06-01
Laboratories today face increasing pressure to automate operations due to increasing workloads and the need to reduce expenditure. Few studies to date have focussed on the laboratory automation of preanalytical coagulation specimen processing. In the present study, we examined whether a clinical chemistry automation protocol meets the preanalytical requirements for the analyses of coagulation. During the implementation of laboratory automation, we began to operate a pre- and postanalytical automation system. The preanalytical unit processes blood specimens for chemistry, immunology and coagulation by automated specimen processing. As the production of platelet-poor plasma is highly dependent on optimal centrifugation, we examined specimen handling under different centrifugation conditions in order to produce optimal platelet deficient plasma specimens. To this end, manually processed models centrifuged at 1500 g for 5 and 20 min were compared to an automated centrifugation model at 3000 g for 7 min. For analytical assays that are performed frequently enough to be targets for full automation, Passing-Bablok regression analysis showed close agreement between different centrifugation methods, with a correlation coefficient between 0.98 and 0.99 and a bias between -5% and +6%. For seldom performed assays that do not mandate full automation, the Passing-Bablok regression analysis showed acceptable to poor agreement between different centrifugation methods. A full automation solution is suitable and can be recommended for frequent haemostasis testing.
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Minoia, C; Pietra, R; Sabbioni, E; Ronchi, A; Gatti, A; Cavalleri, A; Manzo, L
1992-06-09
In the context of a programme concerning the determination of trace elements in body fluids and tissues to establish trace element reference values, research has been undertaken on the control of preanalytical factors in order to develop sufficiently accurate and precise guidelines to be applied in routine work by using techniques such as graphite furnace atomic absorption spectroscopy (GFAAS). Aspects investigated are related to the risk of contamination during blood collection and the use of anticoagulants; the risk of losses during storage and freeze-drying as well as the possible risk of contamination arising from trace elements in airborne particulates of the laboratory environment. For the analysis of Al, Ba, Cd, Co, Cr, Mn, Mo, Ni, Sb, W, V and Zn in blood, Teflon cannula is the method of choice. The anticoagulants do not introduce disturbing contaminations of Rb, Se, Zn, while contaminations were observed for Co, Cr, Mn. Radiotracers in 'metabolized form' (radiolabelled rat or rabbit tissues from animals administered with radioisotopes) show that samples stored for 1 month at -20 degrees C have no significant trace metal losses. Strict ambient air quality standard has to be respected (continuous monitoring) due to the possibility of element contaminations inside the laboratory. The use of matrix modifiers could represent a toxicological risk to the operators. Critical factors should be considered ('metal sheets') for each element in each matrix. For instance 27 factors for Cr in serum have been suggested.
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van Ginkel, Joost H; van den Broek, Daan A; van Kuik, Joyce; Linders, Dorothé; de Weger, Roel; Willems, Stefan M; Huibers, Manon M H
2017-10-01
In current molecular cancer diagnostics, using blood samples of cancer patients for the detection of genetic alterations in plasma (cell-free) circulating tumor DNA (ctDNA) is an emerging practice. Since ctDNA levels in blood are low, highly sensitive Droplet Digital PCR (ddPCR) can be used for detecting rare mutational targets. In order to perform ddPCR on blood samples, a standardized procedure for processing and analyzing blood samples is necessary to facilitate implementation into clinical practice. Therefore, we assessed the technical sample workup procedure for ddPCR on blood plasma samples. Blood samples from healthy individuals, as well as lung cancer patients were analyzed. We compared different methods and protocols for sample collection, storage, centrifugation, isolation, and quantification. Cell-free DNA (cfDNA) concentrations of several wild-type targets and BRAF and EGFR-mutant ctDNA concentrations quantified by ddPCR were primary outcome measurements. Highest cfDNA concentrations were measured in blood collected in serum tubes. No significant differences in cfDNA concentrations were detected between various time points of up to 24 h until centrifugation. Highest cfDNA concentrations were detected after DNA isolation with the Quick cfDNA Serum & Plasma Kit, while plasma isolation using the QIAamp Circulating Nucleic Acid Kit yielded the most consistent results. DdPCR results on cfDNA are highly dependent on multiple factors during preanalytical sample workup, which need to be addressed during the development of this diagnostic tool for cancer diagnostics in the future. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.
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Loit, Evelin; Tricco, Andrea C; Tsouros, Sophia; Sears, Margaret; Ansari, Mohammed T; Booth, Ronald A
2011-07-01
Low thiopurine S-methyltransferase (TPMT) enzyme activity is associated with increased thiopurine drug toxicity, particularly myelotoxicity. Pre-analytic and analytic variables for TPMT genotype and phenotype (enzyme activity) testing were reviewed. A systematic literature review was performed, and diagnostic laboratories were surveyed. Thirty-five studies reported relevant data for pre-analytic variables (patient age, gender, race, hematocrit, co-morbidity, co-administered drugs and specimen stability) and thirty-three for analytic variables (accuracy, reproducibility). TPMT is stable in blood when stored for up to 7 days at room temperature, and 3 months at -30°C. Pre-analytic patient variables do not affect TPMT activity. Fifteen drugs studied to date exerted no clinically significant effects in vivo. Enzymatic assay is the preferred technique. Radiochemical and HPLC techniques had intra- and inter-assay coefficients of variation (CVs) below 10%. TPMT is a stable enzyme, and its assay is not affected by age, gender, race or co-morbidity. Copyright © 2011. Published by Elsevier Inc.
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Zhao, Xuemei; Delgado, Liliana; Weiner, Russell; Laterza, Omar F.
2015-01-01
Thymus- and activation-regulated chemokine (TARC) in serum/plasma associates with the disease activity of atopic dermatitis (AD), and is a promising tool for assessing the response to the treatment of the disease. TARC also exists within platelets, with elevated levels detectable in AD patients. We examined the effects of pre-analytical factors on the quantitation of TARC in human EDTA plasma. TARC levels in platelet-free plasma were significantly lower than those in platelet-containing plasma. After freeze-thaw, TARC levels increased in platelet-containing plasma, but remained unchanged in platelet-free plasma, suggesting TARC was released from the platelets during the freeze-thaw process. In contrast, TARC levels were stable in serum independent of freeze-thaw. These findings underscore the importance of pre-analytical factors to TARC quantitation. Plasma TARC levels should be measured in platelet-free plasma for accurate quantitation. Pre-analytical factors influence the quantitation, interpretation, and implementation of circulating TARC as a biomarker for the development of AD therapeutics. PMID:28936246
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Differences in metabolite profiles caused by pre-analytical blood processing procedures.
Nishiumi, Shin; Suzuki, Makoto; Kobayashi, Takashi; Yoshida, Masaru
2018-05-01
Recently, the use of metabolomic analysis of human serum and plasma for biomarker discovery and disease diagnosis in clinical studies has been increasing. The feasibility of using a metabolite biomarker for disease diagnosis is strongly dependent on the metabolite's stability during pre-analytical blood processing procedures, such as serum or plasma sampling and sample storage prior to centrifugation. However, the influence of blood processing procedures on the stability of metabolites has not been fully characterized. In the present study, we compared the levels of metabolites in matched human serum and plasma samples using gas chromatography coupled with mass spectrometry and liquid chromatography coupled with mass spectrometry. In addition, we evaluated the changes in plasma metabolite levels induced by storage at room temperature or at a cold temperature prior to centrifugation. As a result, it was found that 76 metabolites exhibited significant differences between their serum and plasma levels. Furthermore, the pre-centrifugation storage conditions significantly affected the plasma levels of 45 metabolites. These results highlight the importance of blood processing procedures during metabolome analysis, which should be considered during biomarker discovery and the subsequent use of biomarkers for disease diagnosis. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
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Clinical biochemistry laboratory rejection rates due to various types of preanalytical errors.
Atay, Aysenur; Demir, Leyla; Cuhadar, Serap; Saglam, Gulcan; Unal, Hulya; Aksun, Saliha; Arslan, Banu; Ozkan, Asuman; Sutcu, Recep
2014-01-01
Preanalytical errors, along the process from the beginning of test requests to the admissions of the specimens to the laboratory, cause the rejection of samples. The aim of this study was to better explain the reasons of rejected samples, regarding to their rates in certain test groups in our laboratory. This preliminary study was designed on the rejected samples in one-year period, based on the rates and types of inappropriateness. Test requests and blood samples of clinical chemistry, immunoassay, hematology, glycated hemoglobin, coagulation and erythrocyte sedimentation rate test units were evaluated. Types of inappropriateness were evaluated as follows: improperly labelled samples, hemolysed, clotted specimen, insufficient volume of specimen and total request errors. A total of 5,183,582 test requests from 1,035,743 blood collection tubes were considered. The total rejection rate was 0.65 %. The rejection rate of coagulation group was significantly higher (2.28%) than the other test groups (P < 0.001) including insufficient volume of specimen error rate as 1.38%. Rejection rates of hemolysis, clotted specimen and insufficient volume of sample error were found to be 8%, 24% and 34%, respectively. Total request errors, particularly, for unintelligible requests were 32% of the total for inpatients. The errors were especially attributable to unintelligible requests of inappropriate test requests, improperly labelled samples for inpatients and blood drawing errors especially due to insufficient volume of specimens in a coagulation test group. Further studies should be performed after corrective and preventive actions to detect a possible decrease in rejecting samples.
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Vallefuoco, L; Sorrentino, R; Spalletti Cernia, D; Colucci, G; Portella, G
2012-12-01
The cobas p 630, a fully automated pre-analytical instrument for primary tube handling recently introduced to complete the Cobas(®) TaqMan systems portfolio, was evaluated in conjunction with: the COBAS(®) AmpliPrep/COBAS(®) TaqMan HBV Test, v2.0, COBAS(®) AmpliPrep/COBAS(®) TaqMan HCV Test, v1.0 and COBAS(®) AmpliPrep/COBAS(®) TaqMan HIV Test, v2.0. The instrument performance in transferring samples from primary to secondary tubes, its impact in improving COBAS(®) AmpliPrep/COBAS(®) TaqMan workflow and hands-on reduction and the risk of possible cross-contamination were assessed. Samples from 42 HBsAg positive, 42 HCV and 42 HIV antibody (Ab) positive patients as well as 21 healthy blood donors were processed with or without automated primary tubes. HIV, HCV and HBsAg positive samples showed a correlation index of 0.999, 0.987 and of 0.994, respectively. To assess for cross-contamination, high titer HBV DNA positive samples, HCV RNA and HIV RNA positive samples were distributed in the cobas p 630 in alternate tube positions, adjacent to negative control samples within the same rack. None of the healthy donor samples showed any reactivity. Based on these results, the cobas p 630 can improve workflow and sample tracing in laboratories performing molecular tests, and reduce turnaround time, errors, and risks. Copyright © 2012 Elsevier B.V. All rights reserved.
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21 CFR 866.4070 - RNA Preanalytical Systems.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false RNA Preanalytical Systems. 866.4070 Section 866.4070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents § 866...
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21 CFR 866.4070 - RNA Preanalytical Systems.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false RNA Preanalytical Systems. 866.4070 Section 866.4070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents § 866...
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21 CFR 866.4070 - RNA Preanalytical Systems.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false RNA Preanalytical Systems. 866.4070 Section 866.4070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents § 866...
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21 CFR 866.4070 - RNA Preanalytical Systems.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false RNA Preanalytical Systems. 866.4070 Section 866.4070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents § 866...
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21 CFR 866.4070 - RNA Preanalytical Systems.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false RNA Preanalytical Systems. 866.4070 Section 866.4070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents § 866...
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Vassilakopoulou, Maria; Parisi, Fabio; Siddiqui, Summar; England, Allison M; Zarella, Elizabeth R; Anagnostou, Valsamo; Kluger, Yuval; Hicks, David G; Rimm, David L; Neumeister, Veronique M
2015-03-01
Individualized targeted therapies for cancer patients require accurate and reproducible assessment of biomarkers to be able to plan treatment accordingly. Recent studies have shown highly variable effects of preanalytical variables on gene expression profiling and protein levels of different tissue types. Several publications have described protein degradation of tissue samples as a direct result of delay of formalin fixation of the tissue. Phosphorylated proteins are more labile and epitope degradation can happen within 30 min of cold ischemic time. To address this issue, we evaluated the change in antigenicity of a series of phosphoproteins in paraffin-embedded samples from breast tumors as a function of time to formalin fixation. A tissue microarray consisting of 93 breast cancer specimens with documented time-to-fixation was used to evaluate changes in antigenicity of 12 phosphoepitopes frequently used in research settings as a function of cold ischemic time. Analysis was performed in a quantitative manner using the AQUA technology for quantitative immunofluorescence. For each marker, least squares univariate linear regression was performed and confidence intervals were computed using bootstrapping. The majority of the epitopes tested revealed changes in expression levels with increasing time to formalin fixation. Some phosphorylated proteins, such as phospho-HSP27 and phospho-S6 RP, involved in post-translational modification and stress response pathways increased in expression or phosphorylation levels. Others (like phospho-AKT, phosphor-ERK1/2, phospho-Tyrosine, phospho-MET, and others) are quite labile and loss of antigenicity can be reported within 1-2 h of cold ischemic time. Therefore specimen collection should be closely monitored and subjected to quality control measures to ensure accurate measurement of these epitopes. However, a few phosphoepitopes (like phospho-JAK2 and phospho-ER) are sufficiently robust for routine usage in companion diagnostic testing.
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Wu, Alan H B; Christenson, Robert H; Greene, Dina N; Jaffe, Allan S; Kavsak, Peter A; Ordonez-Llanos, Jordi; Apple, Fred S
2018-04-01
This document is an essential companion to the third iteration of the National Academy of Clinical Biochemistry [NACB, 8 now the American Association for Clinical Chemistry (AACC) Academy] Laboratory Medicine Practice Guidelines (LMPG) on cardiac markers. The expert consensus recommendations were drafted in collaboration with the International Federation of Clinical Chemistry and Laboratory Medicine Task Force on Clinical Applications of Bio-Markers (IFCC TF-CB). We determined that there is sufficient clinical guidance on the use of cardiac troponin (cTn) testing from clinical practice groups. Thus, in this expert consensus document, we focused on clinical laboratory practice recommendations for high-sensitivity (hs)-cTn assays. This document utilized the expert opinion class of evidence to focus on the following 10 topics: ( a ) quality control (QC) utilization, ( b ) validation of the lower reportable analytical limits, ( c ) units to be used in reporting measurable concentrations for patients and QC materials, ( d ) 99th percentile sex-specific upper reference limits to define the reference interval; ( e ) criteria required to define hs-cTn assays, ( f ) communication with clinicians and the laboratory's role in educating clinicians regarding the influence of preanalytic and analytic problems that can confound assay results, ( g ) studies on hs-cTn assays and how authors need to document preanalytical and analytical variables, ( h ) harmonizing and standardizing assay results and the role of commutable materials, ( i ) time to reporting of results from sample receipt and sample collection, and ( j ) changes in hs-cTn concentrations over time and the role of both analytical and biological variabilities in interpreting results of serial blood collections. © 2017 American Association for Clinical Chemistry.
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Post-sampling release of free fatty acids - effects of heat stabilization and methods of euthanasia.
Jernerén, Fredrik; Söderquist, Marcus; Karlsson, Oskar
2015-01-01
The field of lipid research has made progress and it is now possible to study the lipidome of cells and organelles. A basic requirement of a successful lipid study is adequate pre-analytical sample handling, as some lipids can be unstable and postmortem changes can cause substantial accumulation of free fatty acids (FFAs). The aim of the present study was to investigate the effects of conductive heat stabilization and euthanasia methods on FFA levels in the rat brain and liver using liquid chromatography tandem mass spectrometry. The analysis of brain homogenates clearly demonstrated phospholipase activity and time-dependent post-sampling changes in the lipid pool of snap frozen non-stabilized tissue. There was a significant increase in FFAs already at 2min, which continued over time. Heat stabilization was shown to be an efficient method to reduce phospholipase activity and ex vivo lipolysis. Post-sampling effects due to tissue thawing and sample preparation induced a massive release of FFAs (up to 3700%) from non-stabilized liver and brain tissues compared to heat stabilized tissue. Furthermore, the choice of euthanasia method significantly influenced the levels of FFAs in the brain. The FFAs were decreased by 15-44% in the group of animals euthanized by pentobarbital injection compared with CO2 inhalation or decapitation. Our results highlight the importance of considering euthanasia methods and pre-analytical treatment in lipid analysis, factors which may otherwise interfere with the outcome of the experiments. Copyright © 2014 Elsevier Inc. All rights reserved.
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Favaloro, E J; Oliver, S; Mohammed, S; Ahuja, M; Grzechnik, E; Azimulla, S; McDonald, J; Lima-Oliveira, G; Lippi, G
2017-09-01
von Willebrand disease (VWD) reflects a loss or dysfunction in von Willebrand factor (VWF), while haemophilia represents a loss or dysfunction of clotting factors such as factor VIII (FVIII) or FIX. Their diagnosis requires laboratory testing, with this potentially compromised by preanalytical events, including poor sample quality. This study assessed the effect of inadequate mixing as a potential cause of VWD and haemophilia misdiagnosis. After completion of requested testing, 48 consecutive patient samples comprising separate aliquots from single collections were individually pooled, appropriately mixed, then frozen in separate aliquots, either at -20°C or -80°C for 2-7 days. Each sample set was then thawed and the separate aliquots subjected to separate mixing protocols (several inversions, blood roller, vortex) vs a non-mix sample, and all aliquots then tested for various VWF and factor assays. Non-mixing led to substantial reduction in VWF and factors in about 25% of samples, that in some cases could lead to misdiagnosis of VWD or haemophilia. Interestingly, there were also some differences observed with respect to different mixing protocols. Our study identified ineffective or variable mixing of thawed plasma samples as potential causes of misdiagnosis of VWD or haemophilia. Further education regarding the importance of appropriate mixing appears warranted. © 2017 John Wiley & Sons Ltd.
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Technical performance of lactate biosensors and a test-strip device during labour.
Luttkus, A K; Fotopoulou, C; Sehouli, J; Stupin, J; Dudenhausen, J W
2010-04-01
Lactate in fetal blood has a high diagnostic power to detect fetal compromise due to hypoxia, as lactate allows an estimation of duration and intensity of metabolic acidemia. Biosensor technology allows an instantaneous diagnosis of fetal compromise in the delivery room. The goal of the current investigation is to define the preanalytical and analytical biases of this technology under routine conditions in a labour ward in comparison to test-strip technology, which allows measurement of lactate alone. Three lactate biosensors (RapidLab 865, Siemens Medical Solutions Diagnostics, Bad Nauheim, Germany; Radiometer ABL625 and ABL 700, Radiometer Copenhagen, Denmark) and one test-strip device (Lactate Pro, Oxford Instruments, UK) were evaluated regarding precision in serial and repetitive measurements in over 1350 samples of fetal whole blood. The coefficient of variation (CV) and the standard deviation (SD) were calculated. The average value of all three biosensors was defined as an artificial reference value (refval). Blood tonometry was performed in order to test the quality of respiratory parameters and to simulate conditions of fetal hypoxia (pO (2): 10 and 20 mmHg). The precision of serial measurements of all biosensors indicated a coefficient of variation (CV) between 1.55 and 3.16% with an SD from 0.042 to 0.053 mmol/L. The test-strip device (Lactate Pro) mounted to 0.117 mmol/L and 3.99% (SD, CV). When compared to our reference value (refval) ABL 625 showed the closest correlation of -0.1%, while Siemens RapidLab 865 showed an overestimation of +8.9%, ABL700 an underestimation of -6.2% and Lactate Pro of -3.7%. For routine use all tested biosensors show sufficient precision. The test-strip device shows a slightly higher standard deviation. A direct comparison of measured lactate values from the various devices needs to be interpreted with caution as each method detects different lactate concentrations. Furthermore, the 40 min process of tonometry led to an increase of SD and coefficient of variation in all devices. This results in the important preanalytical finding that the precision of replicated measurements worsens significantly with time. The clinician should be aware of the type of analyser used and of preanalytical biases before making clinical decisions on the basis of lactate values.
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Recommendations for accreditation of laboratories in molecular biology of hematologic malignancies.
Flandrin-Gresta, Pascale; Cornillet, Pascale; Hayette, Sandrine; Gachard, Nathalie; Tondeur, Sylvie; Mauté, Carole; Cayuela, Jean-Michel
2015-01-01
Over recent years, the development of molecular biology techniques has improved the hematological diseases diagnostic and follow-up. Consequently, these techniques are largely used in the biological screening of these diseases; therefore the Hemato-oncology molecular diagnostics laboratories must be actively involved in the accreditation process according the ISO 15189 standard. The French group of molecular biologists (GBMHM) provides requirements for the implementation of quality assurance for the medical molecular laboratories. This guideline states the recommendations for the pre-analytical, analytical (methods validation procedures, quality controls, reagents), and post-analytical conditions. In addition, herein we state a strategy for the internal quality control management. These recommendations will be regularly updated.
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Carter, David R. F.; Cheng, Lesley; Compton, Carolyn; Daaboul, George; Devitt, Andrew; Falcon-Perez, Juan Manuel; Gardiner, Chris; Helmbrecht, Clemens; Hendrix, An; Hoffman, Andrew; Kalluri, Raghu; Kang, Ji Yoon; Lässer, Cecilia; Lawson, Charlotte; Lenassi, Metka; Levin, Carina; Llorente, Alicia; Martens-Uzunova, Elena S.; Möller, Andreas; Ochiya, Takahiro; Pink, Ryan C; Tahara, Hidetoshi; Wauben, Marca H. M.; Webber, Jason P.; Yin, Hang; Nieuwland, Rienk
2018-01-01
ABSTRACT This report summarises the presentations and activities of the ISEV Workshop on extracellular vesicle biomarkers held in Birmingham, UK during December 2017. Among the key messages was broad agreement about the importance of biospecimen science. Much greater attention needs to be paid towards the provenance of collected samples. The workshop also highlighted clear gaps in our knowledge about pre-analytical factors that alter extracellular vesicles (EVs). The future utility of certified standards for credentialing of instruments and software, to analyse EV and for tracking the influence of isolation steps on the structure and content of EVs were also discussed. Several example studies were presented, demonstrating the potential utility for EVs in disease diagnosis, prognosis, longitudinal serial testing and stratification of patients. The conclusion of the workshop was that more effort focused on pre-analytical issues and benchmarking of isolation methods is needed to strengthen collaborations and advance more effective biomarkers.
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Lippi, Giuseppe; Plebani, Mario
2011-04-01
Remarkable technological advances and increased awareness have both contributed to decrease substantially the uncertainty of the analytical phase, so that the manually intensive preanalytical activities currently represent the leading sources of errors in laboratory and transfusion medicine. Among preanalytical errors, misidentification and mistransfusion are still regarded as a considerable problem, posing serious risks for patient health and carrying huge expenses for the healthcare system. As such, a reliable policy of risk management should be readily implemented, developing through a multifaceted approach to prevent or limit the adverse outcomes related to transfusion reactions from blood incompatibility. This strategy encompasses root cause analysis, compliance with accreditation requirements, strict adherence to standard operating procedures, guidelines and recommendations for specimen collection, use of positive identification devices, rejection of potentially misidentified specimens, informatics data entry, query host communication, automated systems for patient identification and sample labeling and an adequate and safe environment. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Bridge, Julia A
2017-01-01
The introduction of molecular testing into cytopathology laboratory practice has expanded the types of samples considered feasible for identifying genetic alterations that play an essential role in cancer diagnosis and treatment. Reverse transcription-polymerase chain reaction (RT-PCR), a sensitive and specific technical approach for amplifying a defined segment of RNA after it has been reverse-transcribed into its DNA complement, is commonly used in clinical practice for the identification of recurrent or tumor-specific fusion gene events. Real-time RT-PCR (quantitative RT-PCR), a technical variation, also permits the quantitation of products generated during each cycle of the polymerase chain reaction process. This review addresses qualitative and quantitative pre-analytic and analytic considerations of RT-PCR as they relate to various cytologic specimens. An understanding of these aspects of genetic testing is central to attaining optimal results in the face of the challenges that cytology specimens may present. Cancer Cytopathol 2017;125:11-19. © 2016 American Cancer Society. © 2016 American Cancer Society.
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Distant testing in laboratory hematology and flow cytometry--the Indian experience.
Das Gupta, Amar
2012-06-01
Outsourcing or sending out of patients' samples to other laboratories for hematologic investigations is a common practice these days. Preanalytic variables that alter cellular parameters and levels of analytes in transit and on storage can significantly and adversely affect interpretation of test results in hematology. Awareness of these changes is necessary to avoid misinterpretation of results that in turn could influence medical management decisions.
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Preijers, Frank W M B; van der Velden, Vincent H J; Preijers, Tim; Brooimans, Rik A; Marijt, Erik; Homburg, Christa; van Montfort, Kees; Gratama, Jan W
2016-05-01
In 1985, external quality assurance was initiated in the Netherlands to reduce the between-laboratory variability of leukemia/lymphoma immunophenotyping and to improve diagnostic conclusions. This program consisted of regular distributions of test samples followed by biannual plenary participant meetings in which results were presented and discussed. A scoring system was developed in which the quality of results was rated by systematically reviewing the pre-analytical, analytical, and post-analytical assay stages using three scores, i.e., correct (A), minor fault (B), and major fault (C). Here, we report on 90 consecutive samples distributed to 40-61 participating laboratories between 1998 and 2012. Most samples contained >20% aberrant cells, mainly selected from mature lymphoid malignancies (B or T cell) and acute leukemias (myeloid or lymphoblastic). In 2002, minimally required monoclonal antibody (mAb) panels were introduced, whilst methodological guidelines for all three assay stages were implemented. Retrospectively, we divided the study into subsequent periods of 4 ("initial"), 4 ("learning"), and 7 years ("consolidation") to detect "learning effects." Uni- and multivariate models showed that analytical performance declined since 2002, but that post-analytical performance improved during the entire period. These results emphasized the need to improve technical aspects of the assay, and reflected improved interpretational skills of the participants. A strong effect of participant affiliation in all three assay stages was observed: laboratories in academic and large peripheral hospitals performed significantly better than those in small hospitals. © 2015 International Clinical Cytometry Society. © 2015 International Clinical Cytometry Society.
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Microplates in liquid chromatography--new solution in clinical research? A review.
Krcmova, Lenka; Solichova, Dagmar; Solich, Petr
2013-10-15
Microplates are routinely used in Radio- or Immuno-assays. Recently, microplates have found use not only in analytical but also in the pre-analytical phase in bioanalyses (sample storage, sample preparation). New connection of this technology to liquid chromatography could be economical, fast and simple solution for many routine laboratories handling large sequences of biological samples. This review summarises the application of microplates in bioanalytical laboratories. Different types of sorbents, materials and shapes of microplates are discussed, and the main advantages and disadvantages of microplates used in clinical research are presented. Copyright © 2013 Elsevier B.V. All rights reserved.
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[Blood sampling using "dried blood spot": a clinical biology revolution underway?].
Hirtz, Christophe; Lehmann, Sylvain
2015-01-01
Blood testing using the dried blood spot (DBS) is used since the 1960s in clinical analysis, mainly within the framework of the neonatal screening (Guthrie test). Since then numerous analytes such as nucleic acids, small molecules or lipids, were successfully measured on the DBS. While this pre-analytical method represents an interesting alternative to classic blood sampling, its use in routine is still limited. We review here the different clinical applications of the blood sampling on DBS and estimate its future place, supported by the new methods of analysis as the LC-MS mass spectrometry.
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Mayer, Horst; Brümmer, Jens; Brinkmann, Thomas
2011-01-01
To implement Lean Six Sigma in our central laboratory we conducted a project to measure single pre-analytical steps influencing turnaround time (TAT) of emergency department (ED) serum samples. The traditional approach of extracting data from the Laboratory Information System (LIS) for a retrospective calculation of a mean TAT is not suitable. Therefore, we used radiofrequency identification (RFID) chips for real time tracking of individual samples at any pre-analytical step. 1,200 serum tubes were labelled with RFID chips and were provided to the emergency department. 3 RFID receivers were installed in the laboratory: at the outlet of the pneumatic tube system, at the centrifuge, and in the analyser area. In addition, time stamps of sample entry at the automated sample distributor and communication of results from the analyser were collected from LIS. 1,023 labelled serum tubes arrived at our laboratory. 899 RFID tags were used for TAT calculation. The following transfer times were determined (median 95th percentile in min:sec): pneumatic tube system --> centrifuge (01:25/04:48), centrifuge --> sample distributor (14:06/5:33), sample distributor --> analysis system zone (02:39/15:07), analysis system zone --> result communication (12:42/22:21). Total TAT was calculated at 33:19/57:40 min:sec. Manual processes around centrifugation were identified as a major part of TAT with 44%/60% (median/95th percentile). RFID is a robust, easy to use, and error-free technology and not susceptible to interferences in the laboratory environment. With this study design we were able to measure significant variations in a single manual sample transfer process. We showed that TAT is mainly influenced by manual steps around the centrifugation process and we concluded that centrifugation should be integrated in solutions for total laboratory automation.
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Core components of a comprehensive quality assurance program in anatomic pathology.
Nakhleh, Raouf E
2009-11-01
In this article the core components of a comprehensive quality assurance and improvement plan are outlined. Quality anatomic pathology work comes with focus on accurate, timely, and complete reports. A commitment to continuous quality improvement and a systems approach with a persistent effort helps to achieve this end. Departments should have a quality assurance and improvement plan that includes a risk assessment of real and potential problems facing the laboratory. The plan should also list the individuals responsible for carrying out the program with adequate resources, a defined timetable, and annual assessment for progress and future directions. Quality assurance monitors should address regulatory requirements and be organized by laboratory division (surgical pathology, cytology, etc) as well as 5 segments (preanalytic, analytic, postanalytic phases of the test cycle, turn-around-time, and customer satisfaction). Quality assurance data can also be used to evaluate individual pathologists using multiple parameters with peer group comparison.
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Danese, Elisa; Lippi, Giuseppe; Brocco, Giorgio; Montagnana, Martina; Salvagno, Gian Luca
2016-06-01
The effect of radiofrequency exposure on human health and health care equipment is a matter of ongoing debate. This study was planned to investigate the influence of radiofrequency (RF) waves emitted by a commercial mobile phone on red blood cells (RBC) in vitro. The study population consisted of 16 ostensibly healthy volunteers. Two whole blood specimens were collected from each volunteer. One sample was placed in a plastic rack, 1 cm distant from the chassis of a commercial mobile phone which was activated by a remote phone call lasting 30 min. The other blood sample was placed in another plastic rack, but was kept distant from any type of RF source. The main RBC parameters including RBC count, hematocrit (Ht), hemoglobin, mean corpuscular platelet volume (MPV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and RBC distribution width (RDW-CV) were assessed with an Advia 2120. The exposure of whole blood to the mobile phone call significantly increased Ht, hemoglobin, MCV and MCH, whereas the RBC count, MCHC and RDW-CV remained unchanged. A significant correlation was observed between variation of Ht and those of hemoglobin (p=0.008), MCV (p=0.009) or MCH (p=0.037), as well as between hemoglobin and MCV (p=0.048). Increased values were found in 13/16 (81%) samples for both Ht and hemoglobin, 14/16 (88%) samples for MCH and 16/16 (100%) samples for MCV. These results suggest that close mobile phone exposure may be an unappreciated and possibly underestimated cause of preanalytical bias in RBC testing.
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Khetan, Dheeraj; Katharia, Rahul; Pandey, Hem Chandra; Chaudhary, Rajendra; Harsvardhan, Rajesh; Pandey, Hemchandra; Sonkar, Atul
2018-01-01
BACKGROUND: Blood transfusion chain can be divided into three phases: preanalytical (patient bedside), analytical (steps done at transfusion services), and postanalytical (bedside). Majority (~70%) of events due to blood transfusion have been attributed to errors in bedside blood administration practices. Survey of bedside transfusion practices (pre-analytical and post analytical phase) was done to assess awareness and compliance to guidelines regarding requisition and administration of blood components. MATERIALS AND METHODS: Interview-based questionnaire of ward staff and observational survey of actual transfusion of blood components in total 26 wards of the institute was carried out during November–December 2013. All the collected data were coded (to maintain confidentiality) and analyzed using SPSS (v 20). For analysis, wards were divided into three categories: medical, surgical, and others (including all intensive care units). RESULTS: A total of 104 (33 resident doctors and 71 nursing) staff members were interviewed and observational survey could be conducted in 25 wards during the study period. In the preanalytical phase, major issues were as follows: lack of awareness for institute guidelines (80.6% not aware), improper sampling practices (67.3%), and prescription related (56.7%). In the postanalytical phase, major issues were found to be lack of consent for blood transfusion (72%), improper warming of blood component (~80%), and problems in storage and discarding of blood units. CONCLUSION: There is need to create awareness about policies and guidelines of bed side transfusion among the ward staff. Regular audits are necessary for compliance to guidelines among clinical staff. PMID:29563672
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Møller, Mette F; Søndergaard, Tove R; Kristensen, Helle T; Münster, Anna-Marie B
2017-09-01
Background Centrifugation of blood samples is an essential preanalytical step in the clinical biochemistry laboratory. Centrifugation settings are often altered to optimize sample flow and turnaround time. Few studies have addressed the effect of altering centrifugation settings on analytical quality, and almost all studies have been done using collection tubes with gel separator. Methods In this study, we compared a centrifugation time of 5 min at 3000 × g to a standard protocol of 10 min at 2200 × g. Nine selected general chemistry and immunochemistry analytes and interference indices were studied in lithium heparin plasma tubes and serum tubes without gel separator. Results were evaluated using mean bias, difference plots and coefficient of variation, compared with maximum allowable bias and coefficient of variation used in laboratory routine quality control. Results For all analytes except lactate dehydrogenase, the results were within the predefined acceptance criteria, indicating that the analytical quality was not compromised. Lactate dehydrogenase showed higher values after centrifugation for 5 min at 3000 × g, mean bias was 6.3 ± 2.2% and the coefficient of variation was 5%. Conclusions We found that a centrifugation protocol of 5 min at 3000 × g can be used for the general chemistry and immunochemistry analytes studied, with the possible exception of lactate dehydrogenase, which requires further assessment.
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Bauer, Daniel R; Otter, Michael; Chafin, David R
2018-01-01
Studying and developing preanalytical tools and technologies for the purpose of obtaining high-quality samples for histological assays is a growing field. Currently, there does not exist a standard practice for collecting, fixing, and monitoring these precious samples. There has been some advancement in standardizing collection for the highest profile tumor types, such as breast, where HER2 testing drives therapeutic decisions. This review examines the area of tissue collection, transport, and monitoring of formalin diffusion and details a prototype system that could be used to help standardize tissue collection efforts. We have surveyed recent primary literature sources and conducted several site visits to understand the most error-prone processes in histology laboratories. This effort identified errors that resulted from sample collection techniques and subsequent transport delays from the operating room (OR) to the histology laboratories. We have therefore devised a prototype sample collection and transport concept. The system consists of a custom data logger and cold transport box and takes advantage of a novel cold + warm (named 2 + 2) fixation method. This review highlights the beneficial aspects of standardizing tissue collection, fixation, and monitoring. In addition, a prototype system is introduced that could help standardize these processes and is compatible with use directly in the OR and from remote sites.
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Mansell, Erin; Lunt, Helen; Docherty, Paul
2017-06-01
Delayed separation of red cells from plasma causes pre analytical glucose loss, which in turn results in an under-diagnosis of GDM (gestational diabetes) based on the OGTT (oral glucose tolerance test). In silico investigations may help laboratory decision making, when exploring pragmatic improvements to sample processing. Late pregnancy 0, 1 and 2h 75g OGTT values were obtained from two distinct populations of pregnant women: 1. Values derived from the HAPO (Hyperglycemia and Adverse Pregnancy Outcome) Study and 2. New Zealand women identified as at higher risk of GDM by their caregivers, undergoing OGTT during routine antenatal care. In both populations studied, in silico modelling focussed on the effects of pre-analytical delays in plasma separation, when using fluoride collection tubes. Using a model that 'batched' samples from the three OGTT collection times, diagnostic sensitivity was estimated as follows: 66.1% for HAPO research population and 48.4% for the 1305 women receiving routine antenatal care. If samples were not batched, but processed shortly after each blood sample was collected, then sensitivity increased to 81%. Exploration of a range of clinical and laboratory scenarios using in silico modelling, showed that delaying the processing of pregnancy OGTT samples, using batched sample collection into fluoride tubes, causes unacceptable loss of GDM diagnostic sensitivity across two distinct population groups. This modelling approach will hopefully provide information that helps with final decision making around improved laboratory processing techniques. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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Effect of storage duration on cytokine stability in human serum and plasma.
Vincent, Fabien B; Nim, Hieu T; Lee, Jacinta P W; Morand, Eric F; Harris, James
2018-06-14
Quantification of analytes such as cytokines in serum samples is intrinsic to translational research in immune diseases. Optimising pre-analytical conditions is critical for ensuring study quality, including evaluation of cytokine stability. We aimed to evaluate the effect on cytokine stability of storage duration prior to freezing of serum, and compare to plasma samples obtained from patients with systemic lupus erythematosus (SLE). Protein stability was analysed by simultaneously quantifying 18 analytes using a custom multi-analyte profile in SLE patient serum and plasma samples that had been prospectively stored at 4 °C for pre-determined periods between 0 and 30 days, prior to freezing. Six analytes were excluded from analysis, because most tested samples were above or below the limit of detection. Amongst the 12 analysed proteins, 11 did not show significant signal degradation. Significant signal degradation was observed from the fourth day of storage for a single analyte, CCL19. Proteins levels were more stable in unseparated serum compared to plasma for most analytes, with the exception of IL-37 which appears slightly more stable in plasma. Based on this, a maximum 3 days of storage at 4 °C for unseparated serum samples is recommended for biobanked samples intended for cytokine analysis in studies of human immune disease. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Calvano, C D; Aresta, A; Iacovone, M; De Benedetto, G E; Zambonin, C G; Battaglia, M; Ditonno, P; Rutigliano, M; Bettocchi, C
2010-03-11
Protein analysis in biological fluids, such as urine, by means of mass spectrometry (MS) still suffers for insufficient standardization in protocols for sample collection, storage and preparation. In this work, the influence of these variables on healthy donors human urine protein profiling performed by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was studied. A screening of various urine sample pre-treatment procedures and different sample deposition approaches on the MALDI target was performed. The influence of urine samples storage time and temperature on spectral profiles was evaluated by means of principal component analysis (PCA). The whole optimized procedure was eventually applied to the MALDI-TOF-MS analysis of human urine samples taken from prostate cancer patients. The best results in terms of detected ions number and abundance in the MS spectra were obtained by using home-made microcolumns packed with hydrophilic-lipophilic balance (HLB) resin as sample pre-treatment method; this procedure was also less expensive and suitable for high throughput analyses. Afterwards, the spin coating approach for sample deposition on the MALDI target plate was optimized, obtaining homogenous and reproducible spots. Then, PCA indicated that low storage temperatures of acidified and centrifuged samples, together with short handling time, allowed to obtain reproducible profiles without artifacts contribution due to experimental conditions. Finally, interesting differences were found by comparing the MALDI-TOF-MS protein profiles of pooled urine samples of healthy donors and prostate cancer patients. The results showed that analytical and pre-analytical variables are crucial for the success of urine analysis, to obtain meaningful and reproducible data, even if the intra-patient variability is very difficult to avoid. It has been proven how pooled urine samples can be an interesting way to make easier the comparison between healthy and pathological samples and to individuate possible differences in the protein expression between the two sets of samples. Copyright 2009 Elsevier B.V. All rights reserved.
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Errors in clinical laboratories or errors in laboratory medicine?
Plebani, Mario
2006-01-01
Laboratory testing is a highly complex process and, although laboratory services are relatively safe, they are not as safe as they could or should be. Clinical laboratories have long focused their attention on quality control methods and quality assessment programs dealing with analytical aspects of testing. However, a growing body of evidence accumulated in recent decades demonstrates that quality in clinical laboratories cannot be assured by merely focusing on purely analytical aspects. The more recent surveys on errors in laboratory medicine conclude that in the delivery of laboratory testing, mistakes occur more frequently before (pre-analytical) and after (post-analytical) the test has been performed. Most errors are due to pre-analytical factors (46-68.2% of total errors), while a high error rate (18.5-47% of total errors) has also been found in the post-analytical phase. Errors due to analytical problems have been significantly reduced over time, but there is evidence that, particularly for immunoassays, interference may have a serious impact on patients. A description of the most frequent and risky pre-, intra- and post-analytical errors and advice on practical steps for measuring and reducing the risk of errors is therefore given in the present paper. Many mistakes in the Total Testing Process are called "laboratory errors", although these may be due to poor communication, action taken by others involved in the testing process (e.g., physicians, nurses and phlebotomists), or poorly designed processes, all of which are beyond the laboratory's control. Likewise, there is evidence that laboratory information is only partially utilized. A recent document from the International Organization for Standardization (ISO) recommends a new, broader definition of the term "laboratory error" and a classification of errors according to different criteria. In a modern approach to total quality, centered on patients' needs and satisfaction, the risk of errors and mistakes in pre- and post-examination steps must be minimized to guarantee the total quality of laboratory services.
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Akbani, Rehan; Becker, Karl-Friedrich; Carragher, Neil; Goldstein, Ted; de Koning, Leanne; Korf, Ulrike; Liotta, Lance; Mills, Gordon B; Nishizuka, Satoshi S; Pawlak, Michael; Petricoin, Emanuel F; Pollard, Harvey B; Serrels, Bryan; Zhu, Jingchun
2014-07-01
Reverse phase protein array (RPPA) technology introduced a miniaturized "antigen-down" or "dot-blot" immunoassay suitable for quantifying the relative, semi-quantitative or quantitative (if a well-accepted reference standard exists) abundance of total protein levels and post-translational modifications across a variety of biological samples including cultured cells, tissues, and body fluids. The recent evolution of RPPA combined with more sophisticated sample handling, optical detection, quality control, and better quality affinity reagents provides exquisite sensitivity and high sample throughput at a reasonable cost per sample. This facilitates large-scale multiplex analysis of multiple post-translational markers across samples from in vitro, preclinical, or clinical samples. The technical power of RPPA is stimulating the application and widespread adoption of RPPA methods within academic, clinical, and industrial research laboratories. Advances in RPPA technology now offer scientists the opportunity to quantify protein analytes with high precision, sensitivity, throughput, and robustness. As a result, adopters of RPPA technology have recognized critical success factors for useful and maximum exploitation of RPPA technologies, including the following: preservation and optimization of pre-analytical sample quality, application of validated high-affinity and specific antibody (or other protein affinity) detection reagents, dedicated informatics solutions to ensure accurate and robust quantification of protein analytes, and quality-assured procedures and data analysis workflows compatible with application within regulated clinical environments. In 2011, 2012, and 2013, the first three Global RPPA workshops were held in the United States, Europe, and Japan, respectively. These workshops provided an opportunity for RPPA laboratories, vendors, and users to share and discuss results, the latest technology platforms, best practices, and future challenges and opportunities. The outcomes of the workshops included a number of key opportunities to advance the RPPA field and provide added benefit to existing and future participants in the RPPA research community. The purpose of this report is to share and disseminate, as a community, current knowledge and future directions of the RPPA technology. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.
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Luebker, Stephen A; Wojtkiewicz, Melinda; Koepsell, Scott A
2015-11-01
Formalin-fixed paraffin-embedded (FFPE) tissue is a rich source of clinically relevant material that can yield important translational biomarker discovery using proteomic analysis. Protocols for analyzing FFPE tissue by LC-MS/MS exist, but standardization of procedures and critical analysis of data quality is limited. This study compared and characterized data obtained from FFPE tissue using two methods: a urea in-solution digestion method (UISD) versus a commercially available Qproteome FFPE Tissue Kit method (Qkit). Each method was performed independently three times on serial sections of homogenous FFPE tissue to minimize pre-analytical variations and analyzed with three technical replicates by LC-MS/MS. Data were evaluated for reproducibility and physiochemical distribution, which highlighted differences in the ability of each method to identify proteins of different molecular weights and isoelectric points. Each method replicate resulted in a significant number of new protein identifications, and both methods identified significantly more proteins using three technical replicates as compared to only two. UISD was cheaper, required less time, and introduced significant protein modifications as compared to the Qkit method, which provided more precise and higher protein yields. These data highlight significant variability among method replicates and type of method used, despite minimizing pre-analytical variability. Utilization of only one method or too few replicates (both method and technical) may limit the subset of proteomic information obtained. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Kopcinovic, Lara Milevoj; Vogrinc, Zeljka; Kocijan, Irena; Culej, Jelena; Aralica, Merica; Jokic, Anja; Antoncic, Dragana; Bozovic, Marija
2016-10-15
We hypothesized that extravascular body fluid (EBF) analysis in Croatia is not harmonized and aimed to investigate preanalytical, analytical and postanalytical procedures used in EBF analysis in order to identify key aspects that should be addressed in future harmonization attempts. An anonymous online survey created to explore laboratory testing of EBF was sent to secondary, tertiary and private health care Medical Biochemistry Laboratories (MBLs) in Croatia. Statements were designed to address preanalytical, analytical and postanalytical procedures of cerebrospinal, pleural, peritoneal (ascites), pericardial, seminal, synovial, amniotic fluid and sweat. Participants were asked to declare the strength of agreement with proposed statements using a Likert scale. Mean scores for corresponding separate statements divided according to health care setting were calculated and compared. The survey response rate was 0.64 (58 / 90). None of the participating private MBLs declared to analyse EBF. We report a mean score of 3.45 obtained for all statements evaluated. Deviations from desirable procedures were demonstrated in all EBF testing phases. Minor differences in procedures used for EBF analysis comparing secondary and tertiary health care MBLs were found. The lowest scores were obtained for statements regarding quality control procedures in EBF analysis, participation in proficiency testing programmes and provision of interpretative comments on EBF's test reports. Although good laboratory EBF practice is present in Croatia, procedures for EBF analysis should be further harmonized to improve the quality of EBF testing and patient safety.
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Deciphering Sources of Variability in Clinical Pathology.
Tripathi, Niraj K; Everds, Nancy E; Schultze, A Eric; Irizarry, Armando R; Hall, Robert L; Provencher, Anne; Aulbach, Adam
2017-01-01
The objectives of this session were to explore causes of variability in clinical pathology data due to preanalytical and analytical variables as well as study design and other procedures that occur in toxicity testing studies. The presenters highlighted challenges associated with such variability in differentiating test article-related effects from the effects of experimental procedures and its impact on overall data interpretation. These presentations focused on preanalytical and analytical variables and study design-related factors and their influence on clinical pathology data, and the importance of various factors that influence data interpretation including statistical analysis and reference intervals. Overall, these presentations touched upon potential effect of many variables on clinical pathology parameters, including animal physiology, sample collection process, specimen handling and analysis, study design, and some discussion points on how to manage those variables to ensure accurate interpretation of clinical pathology data in toxicity studies. This article is a brief synopsis of presentations given in a session entitled "Deciphering Sources of Variability in Clinical Pathology-It's Not Just about the Numbers" that occurred at the 35th Annual Symposium of the Society of Toxicologic Pathology in San Diego, California.
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Halim, Abdel-Baset
2015-06-01
An incredibly high failure rate in the pharmaceutical industry has positioned personalized medicine with its prerequisite drug-diagnostic codevelopment, commonly known as companion diagnostics (CDx), in the frontline as an potential rescuer. This hopefulness is potentiated by the recent major advances and competitiveness in molecular diagnostics, making laboratory tests widely accessible at affordable prices. If executed correctly, biomarkers and CDx can potentially help the drug industry by enhancing the probability of success and possibly accelerating time to market; help the diagnostics industry develop tests utilizing precious, clinically annotated human samples; and, more importantly, benefit patients by supporting accurate diagnosis and selection of the most efficacious and least toxic therapies. However, this spectacular road is not yet paved, and it faces an enormous number of challenges. This paper will list these challenges and highlight some critical problems with representative examples of imminent but still overlooked preanalytical and analytical variables that can defeat the whole purpose of biomarkers and CDx and mislead drug developers and clinicians. The paper will provide some suggestions for mitigation. © 2015 New York Academy of Sciences.
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NASA Astrophysics Data System (ADS)
Solivio, Morwena J.; Less, Rebekah; Rynes, Mathew L.; Kramer, Marcus; Aksan, Alptekin
2016-04-01
Despite abundant research conducted on cancer biomarker discovery and validation, to date, less than two-dozen biomarkers have been approved by the FDA for clinical use. One main reason is attributed to inadvertent use of low quality biospecimens in biomarker research. Most proteinaceous biomarkers are extremely susceptible to pre-analytical factors such as collection, processing, and storage. For example, cryogenic storage imposes very harsh chemical, physical, and mechanical stresses on biospecimens, significantly compromising sample quality. In this communication, we report the development of an electrospun lyoprotectant matrix and isothermal vitrification methodology for non-cryogenic stabilization and storage of liquid biospecimens. The lyoprotectant matrix was mainly composed of trehalose and dextran (and various low concentration excipients targeting different mechanisms of damage), and it was engineered to minimize heterogeneity during vitrification. The technology was validated using five biomarkers; LDH, CRP, PSA, MMP-7, and C3a. Complete recovery of LDH, CRP, and PSA levels was achieved post-rehydration while more than 90% recovery was accomplished for MMP-7 and C3a, showing promise for isothermal vitrification as a safe, efficient, and low-cost alternative to cryogenic storage.
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2013-01-01
Introduction Blood culture (BC) testing before initiation of antimicrobial therapy is recommended as a standard of care in international sepsis guidelines and has been shown to reduce intensive care unit (ICU) stay, antibiotic use, and costs in hospitalized patients. Whereas microbiological laboratory practice has been highly standardized, shortfalls in the preanalytic procedures in the ICU (that is indication, time-to-incubation, blood volume and numbers of BC sets) have a significant effect on the diagnostic yield. The objective of this study was to gain insights into current practices regarding BC testing in intensive care units. Methods Qualitative survey, data collection by 138 semi-structured telephone interviews in four European countries (Italy, UK, France and Germany) between September and November 2009 in 79 clinical microbiology laboratories (LABs) and 59 ICUs. Results Whereas BC testing is expected to remain the gold standard for sepsis diagnostics in all countries, there are substantial differences regarding preanalytic procedures. The decision to launch BC testing is carried out by physicians vs. ICU nurses in the UK in 92 vs. 8%, in France in 75 vs. 25%, in Italy in 88 vs. 12% and in Germany in 92 vs. 8%. Physicians vs. nurses collect BCs in the UK in 77 vs. 23%, in France in 0 vs. 100%, in Italy in 6 vs. 94% and in Germany in 54 vs. 46%. The mean time from blood collection to incubation in the UK is 2 h, in France 3 h, in Italy 4 h, but 20 h in German remote LABs (2 h in in-house LABs), due to the large number of remote nonresident microbiological laboratories in Germany. There were major differences between the perception of the quality of BC testing between ICUs and LABs. Among German ICU respondents, 62% reported that they have no problems with BC testing, 15% reported time constraints, 15% cost pressure, and only 8% too long time to incubation. However, the corresponding LABs of these German ICUs reported too many false positive results due to preanalytical contaminations (49%), insufficient numbers of incoming BC sets (47%), long transportation time (41%) or cost pressure (18%). Conclusions There are considerable differences in the quality of BC testing across European countries. In Germany, time to incubation is a considerable problem due to the increasing number of remote LABs. This is a major issue of concern to physicians aiming to implement sepsis guidelines in the ICUs. PMID:24144084
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Collection of biological samples in forensic toxicology.
Dinis-Oliveira, R J; Carvalho, F; Duarte, J A; Remião, F; Marques, A; Santos, A; Magalhães, T
2010-09-01
Forensic toxicology is the study and practice of the application of toxicology to the purposes of the law. The relevance of any finding is determined, in the first instance, by the nature and integrity of the specimen(s) submitted for analysis. This means that there are several specific challenges to select and collect specimens for ante-mortem and post-mortem toxicology investigation. Post-mortem specimens may be numerous and can endow some special difficulties compared to clinical specimens, namely those resulting from autolytic and putrefactive changes. Storage stability is also an important issue to be considered during the pre-analytic phase, since its consideration should facilitate the assessment of sample quality and the analytical result obtained from that sample. The knowledge on degradation mechanisms and methods to increase storage stability may enable the forensic toxicologist to circumvent possible difficulties. Therefore, advantages and limitations of specimen preservation procedures are thoroughfully discussed in this review. Presently, harmonized protocols for sampling in suspected intoxications would have obvious utility. In the present article an overview is given on sampling procedures for routinely collected specimens as well as on alternative specimens that may provide additional information on the route and timing of exposure to a specific xenobiotic. Last, but not least, a discussion on possible bias that can influence the interpretation of toxicological results is provided. This comprehensive review article is intented as a significant help for forensic toxicologists to accomplish their frequently overwhelming mission.
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Specimen rejection in laboratory medicine: Necessary for patient safety?
Dikmen, Zeliha Gunnur; Pinar, Asli; Akbiyik, Filiz
2015-01-01
The emergency laboratory in Hacettepe University Hospitals receives specimens from emergency departments (EDs), inpatient services and intensive care units (ICUs). The samples are accepted according to the rejection criteria of the laboratory. In this study, we aimed to evaluate the sample rejection ratios according to the types of pre-preanalytical errors and collection areas. The samples sent to the emergency laboratory were recorded during 12 months between January to December, 2013 in which 453,171 samples were received and 27,067 specimens were rejected. Rejection ratios was 2.5% for biochemistry tests, 3.2% for complete blood count (CBC), 9.8% for blood gases, 9.2% for urine analysis, 13.3% for coagulation tests, 12.8% for therapeutic drug monitoring, 3.5% for cardiac markers and 12% for hormone tests. The most frequent rejection reasons were fibrin clots (28%) and inadequate volume (9%) for biochemical tests. Clotted samples (35%) and inadequate volume (13%) were the major causes for coagulation tests, blood gas analyses and CBC. The ratio of rejected specimens was higher in the EDs (40%) compared to ICUs (30%) and inpatient services (28%). The highest rejection ratio was observed in neurology ICU (14%) among the ICUs and internal medicine inpatient service (10%) within inpatient clinics. We detected an overall specimen rejection rate of 6% in emergency laboratory. By documentation of rejected samples and periodic training of healthcare personnel, we expect to decrease sample rejection ratios below 2%, improve total quality management of the emergency laboratory and promote patient safety.
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Petit, Morgane; Mine, Louis; Pascreau, Tiffany; Brouzes, Chantal; Majoux, Sandrine; Borgel, Delphine; Beaudeux, Jean-Louis; Lasne, Dominique; Hennequin, Carole
2017-12-01
Pneumatic tube delivery system (PTS) enables to reduce considerably turnaround times. The aim of the study was to assess the influence of the PTS on the quality of routine biochemical and hematological tests in our laboratory. Blood samples from 6 hospitalized patients and 8 healthy volunteers were analyzed. Blood samples were delivered to the laboratory by a PTS and by a human courier. We performed the following analysis: ionized calcium, sodium, potassium, lactate deshydrogenase (LDH), aspartate aminotransferase (ASAT), arterial blood gas, complete blood count and coagulation test as prothrombin time, activated partial thromboplastin time, factors V and VIII. Results were compared between the both method of transport according to the recommendation of the Société française de biologie clinique and the French committee for accreditation (SH-GTA01, norme NF ISO 5275-6). The hemolysis index of plasma was similar between the groups and no morphological differences were found on blood cells. For three samples, when delivered by PTS, LDH levels (two samples) and neutrophil polynuclear count (one sample) were above the recommended guidelines compared to those delivered by courier. Conversely, LDH levels and FVIII were below in two samples delivered by PTS. LDH levels, PNN count or factor VIII can be affected by PTS without the clinical interpretation being modified. We concluded that the PTS can be used to transport blood samples for routine biochemical and hematological analysis in our hospital.
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Lean six sigma methodologies improve clinical laboratory efficiency and reduce turnaround times.
Inal, Tamer C; Goruroglu Ozturk, Ozlem; Kibar, Filiz; Cetiner, Salih; Matyar, Selcuk; Daglioglu, Gulcin; Yaman, Akgun
2018-01-01
Organizing work flow is a major task of laboratory management. Recently, clinical laboratories have started to adopt methodologies such as Lean Six Sigma and some successful implementations have been reported. This study used Lean Six Sigma to simplify the laboratory work process and decrease the turnaround time by eliminating non-value-adding steps. The five-stage Six Sigma system known as define, measure, analyze, improve, and control (DMAIC) is used to identify and solve problems. The laboratory turnaround time for individual tests, total delay time in the sample reception area, and percentage of steps involving risks of medical errors and biological hazards in the overall process are measured. The pre-analytical process in the reception area was improved by eliminating 3 h and 22.5 min of non-value-adding work. Turnaround time also improved for stat samples from 68 to 59 min after applying Lean. Steps prone to medical errors and posing potential biological hazards to receptionists were reduced from 30% to 3%. Successful implementation of Lean Six Sigma significantly improved all of the selected performance metrics. This quality-improvement methodology has the potential to significantly improve clinical laboratories. © 2017 Wiley Periodicals, Inc.
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Kopcinovic, Lara Milevoj; Vogrinc, Zeljka; Kocijan, Irena; Culej, Jelena; Aralica, Merica; Jokic, Anja; Antoncic, Dragana; Bozovic, Marija
2016-01-01
Introduction We hypothesized that extravascular body fluid (EBF) analysis in Croatia is not harmonized and aimed to investigate preanalytical, analytical and postanalytical procedures used in EBF analysis in order to identify key aspects that should be addressed in future harmonization attempts. Materials and methods An anonymous online survey created to explore laboratory testing of EBF was sent to secondary, tertiary and private health care Medical Biochemistry Laboratories (MBLs) in Croatia. Statements were designed to address preanalytical, analytical and postanalytical procedures of cerebrospinal, pleural, peritoneal (ascites), pericardial, seminal, synovial, amniotic fluid and sweat. Participants were asked to declare the strength of agreement with proposed statements using a Likert scale. Mean scores for corresponding separate statements divided according to health care setting were calculated and compared. Results The survey response rate was 0.64 (58 / 90). None of the participating private MBLs declared to analyse EBF. We report a mean score of 3.45 obtained for all statements evaluated. Deviations from desirable procedures were demonstrated in all EBF testing phases. Minor differences in procedures used for EBF analysis comparing secondary and tertiary health care MBLs were found. The lowest scores were obtained for statements regarding quality control procedures in EBF analysis, participation in proficiency testing programmes and provision of interpretative comments on EBF’s test reports. Conclusions Although good laboratory EBF practice is present in Croatia, procedures for EBF analysis should be further harmonized to improve the quality of EBF testing and patient safety. PMID:27812307
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Ricciardelli, Carmela; Bianco-Miotto, Tina; Jindal, Shalini; Dodd, Thomas J; Cohen, Penelope A; Marshall, Villis R; Sutherland, Peter D; Samaratunga, Hemamali; Kench, James G; Dong, Ying; Wang, Hong; Clements, Judith A; Risbridger, Gail P; Sutherland, Robert L; Tilley, Wayne D; Horsfall, David J
2010-07-01
Knowledge of preanalytic conditions that biospecimens are subjected to is critically important because novel surgical procedures, tissue sampling, handling, and storage might affect biomarker expression or invalidate tissue samples as analytes for some technologies. We investigated differences in RNA quality, gene expression by quantitative real-time PCR, and immunoreactive protein expression of selected prostate cancer biomarkers between tissues from retropubic radical prostatectomy (RRP) and robot-assisted laparoscopic prostatectomy (RALP). Sections of tissue microarray of 23 RALP and 22 RRP samples were stained with antibodies to androgen receptor (AR) and prostate-specific antigen (PSA) as intersite controls, and 14 other candidate biomarkers of research interest to three laboratories within the Australian Prostate Cancer BioResource tissue banking network. Quantitative real-time PCR was done for AR, PSA (KLK3), KLK2, KLK4, and HIF1A on RNA extracted from five RALP and five RRP frozen tissue cores. No histologic differences were observed between RALP and RRP tissue. Biomarker staining grouped these samples into those with increased (PSA, CK8/18, CKHMW, KLK4), decreased (KLK2, KLK14), or no change in expression (AR, ghrelin, Ki67, PCNA, VEGF-C, PAR2, YB1, p63, versican, and chondroitin 0-sulfate) in RALP compared with RRP tissue. No difference in RNA quality or gene expression was detected between RALP and RRP tissue. Changes in biomarker expression between RALP and RRP tissue exist at the immunoreactive protein level, but the etiology is unclear. Future studies should account for changes in biomarker expression when using RALP tissues, and mixed cohorts of RALP and RRP tissue should be avoided.
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Espina, Virginia; Mueller, Claudius; Edmiston, Kirsten; Sciro, Manuela; Petricoin, Emanuel F; Liotta, Lance A
2009-08-01
Instability of tissue protein biomarkers is a critical issue for molecular profiling. Pre-analytical variables during tissue procurement, such as time delays during which the tissue remains stored at room temperature, can cause significant variability and bias in downstream molecular analysis. Living tissue, ex vivo, goes through a defined stage of reactive changes that begin with oxidative, hypoxic and metabolic stress, and culminate in apoptosis. Depending on the delay time ex vivo, and reactive stage, protein biomarkers, such as signal pathway phosphoproteins will be elevated or suppressed in a manner which does not represent the biomarker levels at the time of excision. Proteomic data documenting reactive tissue protein changes post collection indicate the need to recognize and address tissue stability, preservation of post-translational modifications, and preservation of morphologic features for molecular analysis. Based on the analysis of phosphoproteins, one of the most labile tissue protein biomarkers, we set forth tissue procurement guidelines for clinical research. We propose technical solutions for (i) assessing the state of protein analyte preservation and specimen quality via identification of a panel of natural proteins (surrogate stability markers), and (ii) using multi-purpose fixative solution designed to stabilize, preserve and maintain proteins, nucleic acids, and tissue architecture.
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Espina, Virginia; Mueller, Claudius; Edmiston, Kirsten; Sciro, Manuela; Petricoin, Emanuel F.; Liotta, Lance A.
2010-01-01
Instability of tissue protein biomarkers is a critical issue for molecular profiling. Pre-analytical variables during tissue procurement, such as time delays during which the tissue remains stored at room temperature, can cause significant variability and bias in downstream molecular analysis. Living tissue, ex vivo, goes through a defined stage of reactive changes that begin with oxidative, hypoxic and metabolic stress, and culminate in apoptosis. Depending on the delay time ex vivo, and reactive stage, protein biomarkers, such as signal pathway phosphoproteins will be elevated or suppressed in a manner which does not represent the biomarker levels at the time of excision. Proteomic data documenting reactive tissue protein changes post collection indicate the need to recognize and address tissue stability, preservation of post-translational modifications, and preservation of morphologic features for molecular analysis. Based on the analysis of phosphoproteins, one of the most labile tissue protein biomarkers, we set forth tissue procurement guidelines for clinical research. We propose technical solutions for (i) assessing the state of protein analyte preservation and specimen quality via identification of a panel of natural proteins (surrogate stability markers), and (ii) using multi-purpose fixative solution designed to stabilize, preserve and maintain proteins, nucleic acids, and tissue architecture. PMID:20871745
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Nikolac, Nora; Šupak-Smolčić, Vesna; Šimundić, Ana-Maria; Ćelap, Ivana
2013-01-01
Phlebotomy is one of the most complex medical procedures in the diagnosis, management and treatment of patients in healthcare. Since laboratory test results are the basis for a large proportion (60–80%) of medical decisions, any error in the phlebotomy process could have serious consequences. In order to minimize the possibility of errors, phlebotomy procedures should be standardised, well-documented and written instructions should be available at every workstation. Croatia is one of the few European countries that have national guidelines for phlebotomy, besides the universally used CLSI (Clinical Laboratory Standards Institute) H3-A6 Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture; approved Standard-Sixth Edition (CLSI, 2007) and WHO (World Health Organization) guidelines on drawing blood: best practices in phlebotomy (WHO, 2010). However, the growing body of evidence in importance of preanalytical phase management resulted in a need for evidence based revision and expansion of existing recommendations. The Croatian Society for Medical Biochemistry and Laboratory Medicine, Working Group for the Preanalytical Phase issued this recommendation. This document is based on the CLSI guideline H3-A6, with significant differences and additional information. PMID:24266294
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Nikolac, Nora; Supak-Smolcić, Vesna; Simundić, Ana-Maria; Celap, Ivana
2013-01-01
Phlebotomy is one of the most complex medical procedures in the diagnosis, management and treatment of patients in healthcare. Since laboratory test results are the basis for a large proportion (60-80%) of medical decisions, any error in the phlebotomy process could have serious consequences. In order to minimize the possibility of errors, phlebotomy procedures should be standardised, well-documented and written instructions should be available at every workstation. Croatia is one of the few European countries that have national guidelines for phlebotomy, besides the universally used CLSI (Clinical Laboratory Standards Institute) H3-A6 Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture; approved Standard-Sixth Edition (CLSI, 2007) and WHO (World Health Organization) guidelines on drawing blood: best practices in phlebotomy (WHO, 2010). However, the growing body of evidence in importance of preanalytical phase management resulted in a need for evidence based revision and expansion of existing recommendations. The Croatian Society for Medical Biochemistry and Laboratory Medicine, Working Group for the Preanalytical Phase issued this recommendation. This document is based on the CLSI guideline H3-A6, with significant differences and additional information.
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Preanalytic Factors Associated With Hemolysis in Emergency Department Blood Samples.
Phelan, Michael P; Reineks, Edmunds Z; Schold, Jesse D; Hustey, Frederic M; Chamberlin, Janelle; Procop, Gary W
2018-02-01
- Hemolysis of emergency department blood samples is a common occurrence and has a negative impact on health care delivery. - To determine the effect of preanalytic factors (straight stick, intravenous [IV] line, needle gauge, location of blood draw, syringe versus vacuum tube use, tourniquet time) on hemolysis in emergency department blood samples. - A single 65 000-visit emergency department's electronic health record was queried for emergency department potassium results and blood draw technique for all samples obtained in calendar year 2014, resulting in 54 531 potassium results. Hemolyzed potassium was measured by hemolysis index. Comparisons of hemolysis by sampling technique were conducted by χ 2 tests. - Overall hemolysis was 10.0% (5439 of 54 531). Hemolysis among samples obtained from straight stick was significantly less than among those obtained with IV line (5.4% [33 of 615] versus 10.2% [4821 of 47 266], P < .001). For IV-placed blood draws, antecubital location had a statistically significant lower overall hemolysis compared with other locations: 7.4% (2117 of 28 786) versus 14.6% (2622 of 17 960) ( P < .001). For blood drawn with a syringe compared with vacuum, hemolysis was 13.0% (92 of 705) and 11.0% (1820 of 16 590), respectively ( P = .09, not significant). For large-gauge IV blood draws versus smaller-gauge IV lines, a lower hemolysis was also observed (9.3% [3882 of 41 571] versus 16.7% [939 of 5633]) ( P < .001). For IV-drawn blood with tourniquet time less than 60 seconds, hemolysis was 10.3% (1362 of 13 162) versus 13.9% for more than 60 seconds (532 of 3832), P < .001. - This study confirmed previous findings that straight stick and antecubital location are significantly associated with reduced hemolysis and indicated that shorter tourniquet time and larger gauge for IV draws were significantly associated with lower hemolysis.
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Hawker, Charles D; McCarthy, William; Cleveland, David; Messinger, Bonnie L
2014-03-01
Mislabeled samples are a serious problem in most clinical laboratories. Published error rates range from 0.39/1000 to as high as 1.12%. Standardization of bar codes and label formats has not yet achieved the needed improvement. The mislabel rate in our laboratory, although low compared with published rates, prompted us to seek a solution to achieve zero errors. To reduce or eliminate our mislabeled samples, we invented an automated device using 4 cameras to photograph the outside of a sample tube. The system uses optical character recognition (OCR) to look for discrepancies between the patient name in our laboratory information system (LIS) vs the patient name on the customer label. All discrepancies detected by the system's software then require human inspection. The system was installed on our automated track and validated with production samples. We obtained 1 009 830 images during the validation period, and every image was reviewed. OCR passed approximately 75% of the samples, and no mislabeled samples were passed. The 25% failed by the system included 121 samples actually mislabeled by patient name and 148 samples with spelling discrepancies between the patient name on the customer label and the patient name in our LIS. Only 71 of the 121 mislabeled samples detected by OCR were found through our normal quality assurance process. We have invented an automated camera system that uses OCR technology to identify potential mislabeled samples. We have validated this system using samples transported on our automated track. Full implementation of this technology offers the possibility of zero mislabeled samples in the preanalytic stage.
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Buschmann, Dominik; Haberberger, Anna; Kirchner, Benedikt; Spornraft, Melanie; Riedmaier, Irmgard; Schelling, Gustav; Pfaffl, Michael W.
2016-01-01
Small RNA-Seq has emerged as a powerful tool in transcriptomics, gene expression profiling and biomarker discovery. Sequencing cell-free nucleic acids, particularly microRNA (miRNA), from liquid biopsies additionally provides exciting possibilities for molecular diagnostics, and might help establish disease-specific biomarker signatures. The complexity of the small RNA-Seq workflow, however, bears challenges and biases that researchers need to be aware of in order to generate high-quality data. Rigorous standardization and extensive validation are required to guarantee reliability, reproducibility and comparability of research findings. Hypotheses based on flawed experimental conditions can be inconsistent and even misleading. Comparable to the well-established MIQE guidelines for qPCR experiments, this work aims at establishing guidelines for experimental design and pre-analytical sample processing, standardization of library preparation and sequencing reactions, as well as facilitating data analysis. We highlight bottlenecks in small RNA-Seq experiments, point out the importance of stringent quality control and validation, and provide a primer for differential expression analysis and biomarker discovery. Following our recommendations will encourage better sequencing practice, increase experimental transparency and lead to more reproducible small RNA-Seq results. This will ultimately enhance the validity of biomarker signatures, and allow reliable and robust clinical predictions. PMID:27317696
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Specimen rejection in laboratory medicine: Necessary for patient safety?
Dikmen, Zeliha Gunnur; Pinar, Asli; Akbiyik, Filiz
2015-01-01
Introduction The emergency laboratory in Hacettepe University Hospitals receives specimens from emergency departments (EDs), inpatient services and intensive care units (ICUs). The samples are accepted according to the rejection criteria of the laboratory. In this study, we aimed to evaluate the sample rejection ratios according to the types of pre-preanalytical errors and collection areas. Materials and methods The samples sent to the emergency laboratory were recorded during 12 months between January to December, 2013 in which 453,171 samples were received and 27,067 specimens were rejected. Results Rejection ratios was 2.5% for biochemistry tests, 3.2% for complete blood count (CBC), 9.8% for blood gases, 9.2% for urine analysis, 13.3% for coagulation tests, 12.8% for therapeutic drug monitoring, 3.5% for cardiac markers and 12% for hormone tests. The most frequent rejection reasons were fibrin clots (28%) and inadequate volume (9%) for biochemical tests. Clotted samples (35%) and inadequate volume (13%) were the major causes for coagulation tests, blood gas analyses and CBC. The ratio of rejected specimens was higher in the EDs (40%) compared to ICUs (30%) and inpatient services (28%). The highest rejection ratio was observed in neurology ICU (14%) among the ICUs and internal medicine inpatient service (10%) within inpatient clinics. Conclusions We detected an overall specimen rejection rate of 6% in emergency laboratory. By documentation of rejected samples and periodic training of healthcare personnel, we expect to decrease sample rejection ratios below 2%, improve total quality management of the emergency laboratory and promote patient safety. PMID:26527231
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The effectiveness of cooling conditions on temperature of canine EDTA whole blood samples
Sun, Xiaocun; Flatland, Bente
2016-01-01
Background Preanalytic factors such as time and temperature can have significant effects on laboratory test results. For example, ammonium concentration will increase 31% in blood samples stored at room temperature for 30 min before centrifugation. To reduce preanalytic error, blood samples may be placed in precooled tubes and chilled on ice or in ice water baths; however, the effectiveness of these modalities in cooling blood samples has not been formally evaluated. The purpose of this study was to evaluate the effectiveness of various cooling modalities on reducing temperature of EDTA whole blood samples. Methods Pooled samples of canine EDTA whole blood were divided into two aliquots. Saline was added to one aliquot to produce a packed cell volume (PCV) of 40% and to the second aliquot to produce a PCV of 20% (simulated anemia). Thirty samples from each aliquot were warmed to 37.7 °C and cooled in 2 ml allotments under one of three conditions: in ice, in ice after transfer to a precooled tube, or in an ice water bath. Temperature of each sample was recorded at one minute intervals for 15 min. Results Within treatment conditions, sample PCV had no significant effect on cooling. Cooling in ice water was significantly faster than cooling in ice only or transferring the sample to a precooled tube and cooling it on ice. Mean temperature of samples cooled in ice water was significantly lower at 15 min than mean temperatures of those cooled in ice, whether or not the tube was precooled. By 4 min, samples cooled in an ice water bath had reached mean temperatures less than 4 °C (refrigeration temperature), while samples cooled in other conditions remained above 4.0 °C for at least 11 min. For samples with a PCV of 40%, precooling the tube had no significant effect on rate of cooling on ice. For samples with a PCV of 20%, transfer to a precooled tube resulted in a significantly faster rate of cooling than direct placement of the warmed tube onto ice. Discussion Canine EDTA whole blood samples cool most rapidly and to a greater degree when placed in an ice-water bath rather than in ice. Samples stored on ice water can rapidly drop below normal refrigeration temperatures; this should be taken into consideration when using this cooling modality. PMID:27917319
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Mensah, Mavis; Borzi, Cristina; Verri, Carla; Suatoni, Paola; Conte, Davide; Pastorino, Ugo; Orazio, Fortunato; Sozzi, Gabriella; Boeri, Mattia
2017-10-26
The development of a minimally invasive test, such as liquid biopsy, for early lung cancer detection in its preclinical phase is crucial to improve the outcome of this deadly disease. MicroRNAs (miRNAs) are tissue specific, small, non-coding RNAs regulating gene expression, which may act as extracellular messengers of biological signals derived from the cross-talk between the tumor and its surrounding microenvironment. They could thus represent ideal candidates for early detection of lung cancer. In this work, a methodological workflow for the prospective validation of a circulating miRNA test using custom made microfluidic cards and quantitative Real-Time PCR in plasma samples of volunteers enrolled in a lung cancer screening trial is proposed. In addition, since the release of hemolysis-related miRNAs and more general technical issues may affect the analysis, the quality control steps included in the standard operating procedures are also presented. The protocol is reproducible and gives reliable quantitative results; however, when using large clinical series, both pre-analytical and analytical features should be cautiously evaluated.
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Lu, Ching-Hua; Kalmar, Bernadett; Malaspina, Andrea; Greensmith, Linda; Petzold, Axel
2011-02-15
Neurofilament (Nf) aggregates are a common pathological feature of neurodegenerative disorders. Although Nf levels have been investigated as a potential disease biomarker, Nf aggregates may mask Nf epitopes, preventing accurate quantification by immunoassay. Using the SOD1(G93A) mouse model of amyotrophic lateral sclerosis, we developed a method to disrupt Nf aggregates, allowing optimal immunoassay performance. Phosphorylated (NfH(SMI35)) and hyperphosphorylated (NfH(SMI34)) Nf levels in plasma from 120-day SOD1(G93A) mice were quantified using an in-house ELISA modified for use with small volumes. Different pre-analytical methods were tested for their ability to solubilize Nf aggregates and immunoblotting was used for qualitative analysis. A 'hook effect' was observed for serially diluted plasma samples quantified using an ELISA originally developed for CSF samples. Immunoblotting confirmed the existence of high molecular-weight NfH aggregates in plasma and the resolving effect of timed urea on these aggregates. Thermostatic (pre-thawing) and chemical (calcium chelators, urea) pre-analytical processing of samples had variable success in disrupting NfH aggregates. Timed urea-calcium chelator incubation yielded the most consistent plasma NfH levels. A one hour sample pre-incubation with 0.5M urea in Barbitone-EDTA buffer at room temperature resolved the "hook effect" without compromising the ELISA. In SOD1(G93A) mice, median levels of NfH(SMI34) were over 10-fold and NfH(SMI35) levels 5-fold greater than controls. NfH aggregates can be solubilised and the "hook effect" abolished by a one-hour sample pre-incubation in a urea-calcium chelator-enriched buffer. This method is applicable for quantification of NfH phosphoforms in experimental and disease settings where Nf aggregate formation occurs. © 2010 Elsevier B.V. All rights reserved.
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Coetzee, L M; Cassim, N; Glencross, D K
2015-12-16
The CD4 integrated service delivery model (ITSDM) provides for reasonable access to pathology services across South Africa (SA) by offering three new service tiers that extend services into remote, under-serviced areas. ITSDM identified Pixley ka Seme as such an under-serviced district. To address the poor service delivery in this area, a new ITSDM community (tier 3) laboratory was established in De Aar, SA. Laboratory performance and turnaround time (TAT) were monitored post implementation to assess the impact on local service delivery. Using the National Health Laboratory Service Corporate Data Warehouse, CD4 data were extracted for the period April 2012-July 2013 (n=11,964). Total mean TAT (in hours) was calculated and pre-analytical and analytical components assessed. Ongoing testing volumes, as well as external quality assessment performance across ten trials, were used to indicate post-implementation success. Data were analysed using Stata 12. Prior to the implementation of CD4 testing at De Aar, the total mean TAT was 20.5 hours. This fell to 8.2 hours post implementation, predominantly as a result of a lower pre-analytical mean TAT reducing from a mean of 18.9 to 1.8 hours. The analytical testing TAT remained unchanged after implementation and monthly test volumes increased by up to 20%. External quality assessment indicated adequate performance. Although subjective, questionnaires sent to facilities reported improved service delivery. Establishing CD4 testing in a remote community laboratory substantially reduces overall TAT. Additional community CD4 laboratories should be established in under-serviced areas, especially where laboratory infrastructure is already in place.
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Impact of Pre-analytic Blood Sample Collection Factors on Metabolomics.
Townsend, Mary K; Bao, Ying; Poole, Elizabeth M; Bertrand, Kimberly A; Kraft, Peter; Wolpin, Brian M; Clish, Clary B; Tworoger, Shelley S
2016-05-01
Many epidemiologic studies are using metabolomics to discover markers of carcinogenesis. However, limited data are available on the influence of pre-analytic blood collection factors on metabolite measurement. We quantified 166 metabolites in archived plasma from 423 Health Professionals Follow-up Study and Nurses' Health Study participants using liquid chromatography-tandem mass spectrometry (LC-MS). We compared multivariable-adjusted geometric mean metabolite LC-MS peak areas across fasting time, season of blood collection, and time of day of blood collection categories. The majority of metabolites (160 of 166 metabolites) had geometric mean peak areas that were within 15% comparing samples donated after fasting 9 to 12 versus ≥13 hours; greater differences were observed in samples donated after fasting ≤4 hours. Metabolite peak areas generally were similar across season of blood collection, although levels of certain metabolites (e.g., bile acids and purines/pyrimidines) tended to be different in the summer versus winter months. After adjusting for fasting status, geometric mean peak areas for bile acids and vitamins, but not other metabolites, differed by time of day of blood collection. Fasting, season of blood collection, and time of day of blood collection were not important sources of variability in measurements of most metabolites in our study. However, considering blood collection variables in the design or analysis of studies may be important for certain specific metabolites, particularly bile acids, purines/pyrimidines, and vitamins. These results may be useful for investigators formulating analysis plans for epidemiologic metabolomics studies, including determining which metabolites to a priori exclude from analyses. Cancer Epidemiol Biomarkers Prev; 25(5); 823-9. ©2016 AACR. ©2016 American Association for Cancer Research.
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Quality performance of laboratory testing in pharmacies: a collaborative evaluation.
Zaninotto, Martina; Miolo, Giorgia; Guiotto, Adriano; Marton, Silvia; Plebani, Mario
2016-11-01
The quality performance and the comparability between results of pharmacies point-of-care-testing (POCT) and institutional laboratories have been evaluated. Eight pharmacies participated in the project: a capillary specimen collected by the pharmacist and, simultaneously, a lithium-heparin sample drawn by a physician of laboratory medicine for the pharmacy customers (n=106) were analyzed in the pharmacy and in the laboratory, respectively. Glucose, cholesterol, HDL-cholesterol, triglycerides, creatinine, uric acid, aspartate aminotransferase, alanine aminotransferase, were measured using: Reflotron, n=5; Samsung, n=1; Cardiocheck PA, n=1; Cholestech LDX, n=1 and Cobas 8000. The POCT analytical performance only (phase 2) were evaluated testing, in pharmacies and in the laboratory, the lithium heparin samples from a female drawn fasting daily in a week, and a control sample containing high concentrations of glucose, cholesterol and triglycerides. For all parameters, except triglycerides, the slopes showed a satisfactory correlation. For triglycerides, a median value higher in POCT in comparison to the laboratory (1.627 mmol/L vs. 0.950 mmol/L) has been observed. The agreement in the subjects classification, demonstrates that for glucose, 70% of the subjects show concentrations below the POCT recommended level (5.8-6.1 mmol/L), while 56% are according to the laboratory limit (<5.6 mmol/L). Total cholesterol exhibits a similar trend while POCT triglycerides show a greater percentage of increased values (21% vs. 9%). The reduction in triglycerides bias (phase 2) suggests that differences between POCT and central laboratory is attributable to a pre-analytical problem. The results confirm the acceptable analytical performance of POCT pharmacies and specific criticisms in the pre- and post-analytical phases.
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Simundic, Ana-Maria; Cornes, Michael; Grankvist, Kjell; Lippi, Giuseppe; Nybo, Mads; Kovalevskaya, Svjetlana; Sprongl, Ludek; Sumarac, Zorica; Church, Stephen
2013-08-01
European questionnaire survey was conducted by the European Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Preanalytical Phase (EFLM WG-PA) to assess how phlebotomy is performed in EFLM countries, including differences in personnel, level of education and skills, and to investigate the presence and compliance of national phlebotomy guidelines on this matter. A questionnaire was constructed containing questions elucidating different aspects of the organization behind the phlebotomy praxis on a national basis, including questions on the staff performing phlebotomy, the education of these staff members, and the existence of and adherence to national guidelines. All 39 EFLM member countries were invited to participate. In total 28/39 (72%) EFLM member countries responded. Seven out of the 28 (25%) have national phlebotomy guidelines and five have implemented other guidelines. The estimated compliance with phlebotomy guidance for the laboratories in the countries that have national guidelines available is poor, regardless to whether the phlebotomy was under the laboratory control or not. Most countries were interested in EFLM guidelines and to participate in a pilot EFLM preanalytical phase external quality assessment (EQA) scheme. In the responding EFLM member countries, the majority of phlebotomy is performed by nurses and laboratory technicians. Their basic education is generally 4-5 years of high school, followed by 2-5 years of colleague or university studies. Only a third (10/28; 36%) of the participating member countries has any specific training available as a continuous educational resource. A specific training for phlebotomy is not part of the education required to become qualified in 6/28 (21%) and 9/28 (32%) of countries for nurses and laboratory technicians, respectively. In countries and professions where training is required, most require more than 5 h of training. Based on the results of this survey we conclude the following: 1) There is a need to assess the quality of current practices, compliance to the CLSI H3-A6 guidelines and to identify some most critical steps which occur during phlebotomy, in different healthcare settings, across Europe; 2) Existing CLSI H3-A6 phlebotomy guidelines should be adapted and used locally in all European countries which do not have their own guidelines; 3) National EFLM societies need to be engaged in basic training program development and continuous education of healthcare phlebotomy staff (implementing the certification of competence).
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Blood transfusion-acquired hemoglobin C.
Suarez, A A; Polski, J M; Grossman, B J; Johnston, M F
1999-07-01
Unexpected and confusing laboratory test results can occur if a blood sample is inadvertently collected following a blood transfusion. A potential for transfusion-acquired hemoglobinopathy exists because heterozygous individuals show no significant abnormalities during the blood donor screening process. Such spurious results are infrequently reported in the medical literature. We report a case of hemoglobin C passively transferred during a red blood cell transfusion. The proper interpretation in our case was assisted by calculations comparing expected hemoglobin C concentration with the measured value. A review of the literature on transfusion-related preanalytic errors is provided.
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Guidance for laboratories performing molecular pathology for cancer patients
Cree, Ian A; Deans, Zandra; Ligtenberg, Marjolijn J L; Normanno, Nicola; Edsjö, Anders; Rouleau, Etienne; Solé, Francesc; Thunnissen, Erik; Timens, Wim; Schuuring, Ed; Dequeker, Elisabeth; Murray, Samuel; Dietel, Manfred; Groenen, Patricia; Van Krieken, J Han
2014-01-01
Molecular testing is becoming an important part of the diagnosis of any patient with cancer. The challenge to laboratories is to meet this need, using reliable methods and processes to ensure that patients receive a timely and accurate report on which their treatment will be based. The aim of this paper is to provide minimum requirements for the management of molecular pathology laboratories. This general guidance should be augmented by the specific guidance available for different tumour types and tests. Preanalytical considerations are important, and careful consideration of the way in which specimens are obtained and reach the laboratory is necessary. Sample receipt and handling follow standard operating procedures, but some alterations may be necessary if molecular testing is to be performed, for instance to control tissue fixation. DNA and RNA extraction can be standardised and should be checked for quality and quantity of output on a regular basis. The choice of analytical method(s) depends on clinical requirements, desired turnaround time, and expertise available. Internal quality control, regular internal audit of the whole testing process, laboratory accreditation, and continual participation in external quality assessment schemes are prerequisites for delivery of a reliable service. A molecular pathology report should accurately convey the information the clinician needs to treat the patient with sufficient information to allow for correct interpretation of the result. Molecular pathology is developing rapidly, and further detailed evidence-based recommendations are required for many of the topics covered here. PMID:25012948
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A content validated questionnaire for assessment of self reported venous blood sampling practices
2012-01-01
Background Venous blood sampling is a common procedure in health care. It is strictly regulated by national and international guidelines. Deviations from guidelines due to human mistakes can cause patient harm. Validated questionnaires for health care personnel can be used to assess preventable "near misses"--i.e. potential errors and nonconformities during venous blood sampling practices that could transform into adverse events. However, no validated questionnaire that assesses nonconformities in venous blood sampling has previously been presented. The aim was to test a recently developed questionnaire in self reported venous blood sampling practices for validity and reliability. Findings We developed a questionnaire to assess deviations from best practices during venous blood sampling. The questionnaire contained questions about patient identification, test request management, test tube labeling, test tube handling, information search procedures and frequencies of error reporting. For content validity, the questionnaire was confirmed by experts on questionnaires and venous blood sampling. For reliability, test-retest statistics were used on the questionnaire answered twice. The final venous blood sampling questionnaire included 19 questions out of which 9 had in total 34 underlying items. It was found to have content validity. The test-retest analysis demonstrated that the items were generally stable. In total, 82% of the items fulfilled the reliability acceptance criteria. Conclusions The questionnaire could be used for assessment of "near miss" practices that could jeopardize patient safety and gives several benefits instead of assessing rare adverse events only. The higher frequencies of "near miss" practices allows for quantitative analysis of the effect of corrective interventions and to benchmark preanalytical quality not only at the laboratory/hospital level but also at the health care unit/hospital ward. PMID:22260505
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A content validated questionnaire for assessment of self reported venous blood sampling practices.
Bölenius, Karin; Brulin, Christine; Grankvist, Kjell; Lindkvist, Marie; Söderberg, Johan
2012-01-19
Venous blood sampling is a common procedure in health care. It is strictly regulated by national and international guidelines. Deviations from guidelines due to human mistakes can cause patient harm. Validated questionnaires for health care personnel can be used to assess preventable "near misses"--i.e. potential errors and nonconformities during venous blood sampling practices that could transform into adverse events. However, no validated questionnaire that assesses nonconformities in venous blood sampling has previously been presented. The aim was to test a recently developed questionnaire in self reported venous blood sampling practices for validity and reliability. We developed a questionnaire to assess deviations from best practices during venous blood sampling. The questionnaire contained questions about patient identification, test request management, test tube labeling, test tube handling, information search procedures and frequencies of error reporting. For content validity, the questionnaire was confirmed by experts on questionnaires and venous blood sampling. For reliability, test-retest statistics were used on the questionnaire answered twice. The final venous blood sampling questionnaire included 19 questions out of which 9 had in total 34 underlying items. It was found to have content validity. The test-retest analysis demonstrated that the items were generally stable. In total, 82% of the items fulfilled the reliability acceptance criteria. The questionnaire could be used for assessment of "near miss" practices that could jeopardize patient safety and gives several benefits instead of assessing rare adverse events only. The higher frequencies of "near miss" practices allows for quantitative analysis of the effect of corrective interventions and to benchmark preanalytical quality not only at the laboratory/hospital level but also at the health care unit/hospital ward.
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Angeletti, Silvia; De Cesaris, Marina; Hart, Jonathan George; Urbano, Michele; Vitali, Massimiliano Andrea; Fragliasso, Fulvio; Dicuonzo, Giordano
2015-12-01
Intra-laboratory turnaround time (TAT) is a key indicator of laboratory performance. Improving TAT is a complex task requiring staff education, equipment acquisition, and adequate TAT monitoring. The aim of the present study was to evaluate the intra-laboratory TAT after laboratory automation implementation (June 2013-June 2014) and to compare it to that in the preautomation period (July 2012-May 2013). Intra-laboratory TAT was evaluated both as the mean TAT registered and the percentage of outlier (OP) exams. The mean TAT was 36, 38, and 34 min during the study periods, respectively. These values respected the goal TAT established at 45 min. The OP, calculated at 45 min as well as at 60 min, decreased from 26 to 21 and from 11 to 5, respectively. From a focused analysis on blood count cell, troponin I, and prothrombin (PT) test, TAT improvement was more evident for tests requiring longer preanalytical process. The follow-up of TAT from June 2013 to June 2014 revealed the reduction of the mean TAT as well as of the OP exams after automation implementation and that automation more strongly affects the test in the preanalytical phase including centrifugation of the sample, such as troponin I and PT. © 2015 Society for Laboratory Automation and Screening.
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Case report of unexplained hypocalcaemia in a slightly haemolysed sample.
Cornes, Michael
2017-06-15
The case presented highlights a common pre-analytical problem identified in the laboratory that was initially missed. It concerns a young, generally healthy adult patient with no significant medical history and no significant family history. They presented with common flu like symptoms to their primary care clinician who considered this was most likely a viral problem that would pass with time. The clinician, however, did some routine bloods to reassure the patient despite a lack of clinical indication. When the sample was analysed the sample was haemolysed with strikingly low calcium. This led to the patient being called into hospital for urgent repeat investigations, all of which turned out to be within normal ranges. On further investigation the original sample was found to be contaminated. This result would normally have been flagged but was missed due to the complication of haemolysis.
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Imoh, Lucius C; Mutale, Mubanga; Parker, Christopher T; Erasmus, Rajiv T; Zemlin, Annalise E
2016-01-01
Timeliness of laboratory results is crucial to patient care and outcome. Monitoring turnaround times (TAT), especially for emergency tests, is important to measure the effectiveness and efficiency of laboratory services. Laboratory-based clinical audits reveal opportunities for improving quality. Our aim was to identify the most critical steps causing a high TAT for cerebrospinal fluid (CSF) chemistry analysis in our laboratory. A 6-month retrospective audit was performed. The duration of each operational phase across the laboratory work flow was examined. A process-mapping audit trail of 60 randomly selected requests with a high TAT was conducted and reasons for high TAT were tested for significance. A total of 1505 CSF chemistry requests were analysed. Transport of samples to the laboratory was primarily responsible for the high average TAT (median TAT = 170 minutes). Labelling accounted for most delays within the laboratory (median TAT = 71 minutes) with most delays occurring after regular work hours (P < 0.05). CSF chemistry requests without the appropriate number of CSF sample tubes were significantly associated with delays in movement of samples from the labelling area to the technologist's work station (caused by a preference for microbiological testing prior to CSF chemistry). A laboratory-based clinical audit identified sample transportation, work shift periods and use of inappropriate CSF sample tubes as drivers of high TAT for CSF chemistry in our laboratory. The results of this audit will be used to change pre-analytical practices in our laboratory with the aim of improving TAT and customer satisfaction.
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Aguilar-Mahecha, Adriana; Kuzyk, Michael A.; Domanski, Dominik; Borchers, Christoph H.; Basik, Mark
2012-01-01
Blood sample processing and handling can have a significant impact on the stability and levels of proteins measured in biomarker studies. Such pre-analytical variability needs to be well understood in the context of the different proteomics platforms available for biomarker discovery and validation. In the present study we evaluated different types of blood collection tubes including the BD P100 tube containing protease inhibitors as well as CTAD tubes, which prevent platelet activation. We studied the effect of different processing protocols as well as delays in tube processing on the levels of 55 mid and high abundance plasma proteins using novel multiple-reaction monitoring-mass spectrometry (MRM-MS) assays as well as 27 low abundance cytokines using a commercially available multiplexed bead-based immunoassay. The use of P100 tubes containing protease inhibitors only conferred proteolytic protection for 4 cytokines and only one MRM-MS-measured peptide. Mid and high abundance proteins measured by MRM are highly stable in plasma left unprocessed for up to six hours although platelet activation can also impact the levels of these proteins. The levels of cytokines were elevated when tubes were centrifuged at cold temperature, while low levels were detected when samples were collected in CTAD tubes. Delays in centrifugation also had an impact on the levels of cytokines measured depending on the type of collection tube used. Our findings can help in the development of guidelines for blood collection and processing for proteomic biomarker studies. PMID:22701622
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Aguilar-Mahecha, Adriana; Kuzyk, Michael A; Domanski, Dominik; Borchers, Christoph H; Basik, Mark
2012-01-01
Blood sample processing and handling can have a significant impact on the stability and levels of proteins measured in biomarker studies. Such pre-analytical variability needs to be well understood in the context of the different proteomics platforms available for biomarker discovery and validation. In the present study we evaluated different types of blood collection tubes including the BD P100 tube containing protease inhibitors as well as CTAD tubes, which prevent platelet activation. We studied the effect of different processing protocols as well as delays in tube processing on the levels of 55 mid and high abundance plasma proteins using novel multiple-reaction monitoring-mass spectrometry (MRM-MS) assays as well as 27 low abundance cytokines using a commercially available multiplexed bead-based immunoassay. The use of P100 tubes containing protease inhibitors only conferred proteolytic protection for 4 cytokines and only one MRM-MS-measured peptide. Mid and high abundance proteins measured by MRM are highly stable in plasma left unprocessed for up to six hours although platelet activation can also impact the levels of these proteins. The levels of cytokines were elevated when tubes were centrifuged at cold temperature, while low levels were detected when samples were collected in CTAD tubes. Delays in centrifugation also had an impact on the levels of cytokines measured depending on the type of collection tube used. Our findings can help in the development of guidelines for blood collection and processing for proteomic biomarker studies.
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Pre-Analytical Conditions in Non-Invasive Prenatal Testing of Cell-Free Fetal RHD
Rieneck, Klaus; Krog, Grethe Risum; Nielsen, Leif Kofoed; Tabor, Ann; Dziegiel, Morten Hanefeld
2013-01-01
Background Non-invasive prenatal testing of cell-free fetal DNA (cffDNA) in maternal plasma can predict the fetal RhD type in D negative pregnant women. In Denmark, routine antenatal screening for the fetal RhD gene (RHD) directs the administration of antenatal anti-D prophylaxis only to women who carry an RhD positive fetus. Prophylaxis reduces the risk of immunization that may lead to hemolytic disease of the fetus and the newborn. The reliability of predicting the fetal RhD type depends on pre-analytical factors and assay sensitivity. We evaluated the testing setup in the Capital Region of Denmark, based on data from routine antenatal RHD screening. Methods Blood samples were drawn at gestational age 25 weeks. DNA extracted from 1 mL of plasma was analyzed for fetal RHD using a duplex method for exon 7/10. We investigated the effect of blood sample transportation time (n = 110) and ambient outdoor temperatures (n = 1539) on the levels of cffDNA and total DNA. We compared two different quantification methods, the delta Ct method and a universal standard curve. PCR pipetting was compared on two systems (n = 104). Results The cffDNA level was unaffected by blood sample transportation for up to 9 days and by ambient outdoor temperatures ranging from -10°C to 28°C during transport. The universal standard curve was applicable for cffDNA quantification. Identical levels of cffDNA were observed using the two automated PCR pipetting systems. We detected a mean of 100 fetal DNA copies/mL at a median gestational age of 25 weeks (range 10–39, n = 1317). Conclusion The setup for real-time PCR-based, non-invasive prenatal testing of cffDNA in the Capital Region of Denmark is very robust. Our findings regarding the transportation of blood samples demonstrate the high stability of cffDNA. The applicability of a universal standard curve facilitates easy cffDNA quantification. PMID:24204719
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Pre-analytical conditions in non-invasive prenatal testing of cell-free fetal RHD.
Clausen, Frederik Banch; Jakobsen, Tanja Roien; Rieneck, Klaus; Krog, Grethe Risum; Nielsen, Leif Kofoed; Tabor, Ann; Dziegiel, Morten Hanefeld
2013-01-01
Non-invasive prenatal testing of cell-free fetal DNA (cffDNA) in maternal plasma can predict the fetal RhD type in D negative pregnant women. In Denmark, routine antenatal screening for the fetal RhD gene (RHD) directs the administration of antenatal anti-D prophylaxis only to women who carry an RhD positive fetus. Prophylaxis reduces the risk of immunization that may lead to hemolytic disease of the fetus and the newborn. The reliability of predicting the fetal RhD type depends on pre-analytical factors and assay sensitivity. We evaluated the testing setup in the Capital Region of Denmark, based on data from routine antenatal RHD screening. Blood samples were drawn at gestational age 25 weeks. DNA extracted from 1 mL of plasma was analyzed for fetal RHD using a duplex method for exon 7/10. We investigated the effect of blood sample transportation time (n = 110) and ambient outdoor temperatures (n = 1539) on the levels of cffDNA and total DNA. We compared two different quantification methods, the delta Ct method and a universal standard curve. PCR pipetting was compared on two systems (n = 104). The cffDNA level was unaffected by blood sample transportation for up to 9 days and by ambient outdoor temperatures ranging from -10 °C to 28 °C during transport. The universal standard curve was applicable for cffDNA quantification. Identical levels of cffDNA were observed using the two automated PCR pipetting systems. We detected a mean of 100 fetal DNA copies/mL at a median gestational age of 25 weeks (range 10-39, n = 1317). The setup for real-time PCR-based, non-invasive prenatal testing of cffDNA in the Capital Region of Denmark is very robust. Our findings regarding the transportation of blood samples demonstrate the high stability of cffDNA. The applicability of a universal standard curve facilitates easy cffDNA quantification.
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Chaudhary, Rajendra; Dubey, Anju; Sonker, Atul
2017-01-01
Blood donor hemoglobin (Hb) estimation is an important donation test that is performed prior to blood donation. It serves the dual purpose of protecting the donors' health against anemia and ensuring good quality of blood components, which has an implication on recipients' health. Diverse cutoff criteria have been defined world over depending on population characteristics; however, no testing methodology and sample requirement have been specified for Hb screening. Besides the technique, there are several physiological and methodological factors that affect accuracy and reliability of Hb estimation. These include the anatomical source of blood sample, posture of the donor, timing of sample and several other biological factors. Qualitative copper sulfate gravimetric method has been the archaic time-tested method that is still used in resource-constrained settings. Portable hemoglobinometers are modern quantitative devices that have been further modified to reagent-free cuvettes. Furthermore, noninvasive spectrophotometry was introduced, mitigating pain to blood donor and eliminating risk of infection. Notwithstanding a tremendous evolution in terms of ease of operation, accuracy, mobility, rapidity and cost, a component of inherent variability persists, which may partly be attributed to pre-analytical variables. Hence, blood centers should pay due attention to validation of test methodology, competency of operating staff and regular proficiency testing of the outputs. In this article, we have reviewed various regulatory guidelines, described the variables that affect the measurements and compared the validated technologies for Hb screening of blood donors along with enumeration of their merits and limitations.
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Mitra, Vikram; Govorukhina, Natalia; Zwanenburg, Gooitzen; Hoefsloot, Huub; Westra, Inge; Smilde, Age; Reijmers, Theo; van der Zee, Ate G J; Suits, Frank; Bischoff, Rainer; Horvatovich, Péter
2016-04-19
Complex shotgun proteomics peptide profiles obtained in quantitative differential protein expression studies, such as in biomarker discovery, may be affected by multiple experimental factors. These preanalytical factors may affect the measured protein abundances which in turn influence the outcome of the associated statistical analysis and validation. It is therefore important to determine which factors influence the abundance of peptides in a complex proteomics experiment and to identify those peptides that are most influenced by these factors. In the current study we analyzed depleted human serum samples to evaluate experimental factors that may influence the resulting peptide profile such as the residence time in the autosampler at 4 °C, stopping or not stopping the trypsin digestion with acid, the type of blood collection tube, different hemolysis levels, differences in clotting times, the number of freeze-thaw cycles, and different trypsin/protein ratios. To this end we used a two-level fractional factorial design of resolution IV (2(IV)(7-3)). The design required analysis of 16 samples in which the main effects were not confounded by two-factor interactions. Data preprocessing using the Threshold Avoiding Proteomics Pipeline (Suits, F.; Hoekman, B.; Rosenling, T.; Bischoff, R.; Horvatovich, P. Anal. Chem. 2011, 83, 7786-7794, ref 1) produced a data-matrix containing quantitative information on 2,559 peaks. The intensity of the peaks was log-transformed, and peaks having intensities of a low t-test significance (p-value > 0.05) and a low absolute fold ratio (<2) between the two levels of each factor were removed. The remaining peaks were subjected to analysis of variance (ANOVA)-simultaneous component analysis (ASCA). Permutation tests were used to identify which of the preanalytical factors influenced the abundance of the measured peptides most significantly. The most important preanalytical factors affecting peptide intensity were (1) the hemolysis level, (2) stopping trypsin digestion with acid, and (3) the trypsin/protein ratio. This provides guidelines for the experimentalist to keep the ratio of trypsin/protein constant and to control the trypsin reaction by stopping it with acid at an accurately set pH. The hemolysis level cannot be controlled tightly as it depends on the status of a patient's blood (e.g., red blood cells are more fragile in patients undergoing chemotherapy) and the care with which blood was sampled (e.g., by avoiding shear stress). However, its level can be determined with a simple UV spectrophotometric measurement and samples with extreme levels or the peaks affected by hemolysis can be discarded from further analysis. The loadings of the ASCA model led to peptide peaks that were most affected by a given factor, for example, to hemoglobin-derived peptides in the case of the hemolysis level. Peak intensity differences for these peptides were assessed by means of extracted ion chromatograms confirming the results of the ASCA model.
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Fabbretti, G
2010-06-01
Because of its complex nature, surgical pathology practice is prone to error. In this report, we describe our methods for reducing error as much as possible during the pre-analytical and analytical phases. This was achieved by revising procedures, and by using computer technology and automation. Most mistakes are the result of human error in the identification and matching of patient and samples. To avoid faulty data interpretation, we employed a new comprehensive computer system that acquires all patient ID information directly from the hospital's database with a remote order entry; it also provides label and request forms via-Web where clinical information is required before sending the sample. Both patient and sample are identified directly and immediately at the site where the surgical procedures are performed. Barcode technology is used to input information at every step and automation is used for sample blocks and slides to avoid errors that occur when information is recorded or transferred by hand. Quality control checks occur at every step of the process to ensure that none of the steps are left to chance and that no phase is dependent on a single operator. The system also provides statistical analysis of errors so that new strategies can be implemented to avoid repetition. In addition, the staff receives frequent training on avoiding errors and new developments. The results have been shown promising results with a very low error rate (0.27%). None of these compromised patient health and all errors were detected before the release of the diagnosis report.
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Cankovic, Milena; Varney, Ruan C.; Whiteley, Lisa; Brown, Ron; D'Angelo, Rita; Chitale, Dhananjay; Zarbo, Richard J.
2009-01-01
Accurate and timely molecular test results play an important role in patient management; consequently, there is a customer expectation of short testing turnaround times. Baseline data analysis revealed that the greatest challenge to timely result generation occurred in the preanalytic phase of specimen collection and transport. Here, we describe our efforts to improve molecular testing turnaround times by focusing primarily on redesign of preanalytic processes using the principles of LEAN production. Our goal was to complete greater than 90% of the molecular tests in less than 3 days. The project required cooperation from different laboratory disciplines as well as individuals outside of the laboratory. The redesigned processes involved defining and standardizing the protocols and approaching blood and tissue specimens as analytes for molecular testing. The LEAN process resulted in fewer steps, approaching the ideal of a one-piece flow for specimens through collection/retrieval, transport, and different aspects of the testing process. The outcome of introducing the LEAN process has been a 44% reduction in molecular test turnaround time for tissue specimens, from an average of 2.7 to 1.5 days. In addition, extending LEAN work principles to the clinician suppliers has resulted in a markedly increased number of properly collected and shipped blood specimens (from 50 to 87%). These continuous quality improvements were accomplished by empowered workers in a blame-free environment and are now being sustained with minimal management involvement. PMID:19661386
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Satisfying regulatory and accreditation requirements for quality control.
Ehrmeyer, Sharon S
2013-03-01
The Clinical Laboratory Improvement Amendments of 1988 (CLIA) requires all US clinical laboratories that test "materials derived from the human body for the purpose of providing information for the diagnosis, prevention, or treatment of any disease..." to be regulated. The CLIA mandates are site neutral; based on test complexity; and focus on the three phases of the testing process (preanalytical, analytical, and postanalytical). Many testing sites choose to meet the CLIA requirements by following the testing standards of a professional accreditation organization deemed by the Centers for Medicare and Medicaid Services. The three principal organizations are The Joint Commission, the College of American Pathologists, and COLA. Copyright © 2013 Elsevier Inc. All rights reserved.
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Piaton, Eric; Fabre, Monique; Goubin-Versini, Isabelle; Bretz-Grenier, Marie-Françoise; Courtade-Saïdi, Monique; Vincent, Serge; Belleannée, Geneviève; Thivolet, Françoise; Boutonnat, Jean; Debaque, Hervé; Fleury-Feith, Jocelyne; Vielh, Philippe; Cochand-Priollet, Béatrix; Egelé, Caroline; Bellocq, Jean-Pierre; Michiels, Jean-François
2015-08-01
May-Grünwald-Giemsa (MGG) stain is a Romanowsky-type, polychromatic stain as those of Giemsa, Leishman and Wright. Apart being the reference method of haematology, it has become a routine stain of diagnostic cytopathology for the study of air-dried preparations (lymph node imprints, centrifuged body fluids and fine needle aspirations). In the context of their actions of promoting the principles of quality assurance in cytopathology, the French Association for Quality Assurance in Anatomic and Cytologic Pathology (AFAQAP) and the French Society of Clinical Cytology (SFCC) conducted a proficiency test on MGG stain in 2013. Results from the test, together with the review of literature data allow pre-analytical and analytical steps of MGG stain to be updated. Recommendations include rapid air-drying of cell preparations/imprints, fixation using either methanol or May-Grünwald alone for 3-10minutes, two-step staining: 50% May-Grünwald in buffer pH 6.8 v/v for 3-5minutes, followed by 10% buffered Giemsa solution for 10-30minutes, and running water for 1-3minutes. Quality evaluation must be performed on red blood cells (RBCs) and leukocytes, not on tumour cells. Under correct pH conditions, RBCs must appear pink-orange (acidophilic) or buff-coloured, neither green nor blue. Leukocyte cytoplasm must be almost transparent, with clearly delineated granules. However, staining may vary somewhat and testing is recommended for automated methods (slide stainers) which remain the standard for reproducibility. Though MGG stain remains the reference stain, Diff-Quik(®) stain can be used for the rapid evaluation of cell samples. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
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Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Picheth, Geraldo; Guidi, Gian Cesare
2013-04-01
Sometimes in-vitro diagnostic devices (e.g. blood collection tubes) are not validated before use or when the producer's brand is changed. The aim of this study was to validate five brands of sodium citrate vacuum tubes. Blood specimens from 50 volunteers were collected in five different tube brands (I: Venosafe, II: VACUETTE, III: BD Vacutainer, IV: LABOR IMPORT and V: S-Monovette). Routine coagulation tests [activated partial thromboplastin time (aPTT), prothrombin time (PT), and fibrinogen (FIB)] were performed on ACL TOP instrument using HemosIL reagents. The significance of the differences between samples was assessed by paired Student's t-test, set at P < 0.005. Significant differences were observed for: PT when comparing I vs. II, I vs. III, I vs. V, II vs. III, II vs. IV, II vs. V, III vs. IV, III vs. V and IV vs. V; aPTT when comparing I vs. II, I vs. III, I vs. IV, II vs. IV, III vs. IV and IV vs. V. No differences were observed among brands for FIB determination. We suggest that every laboratory management should both standardize the procedures and frequently evaluate the quality of in-vitro diagnostic devices.
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Clinical utility of cerebrospinal fluid biomarkers in the diagnosis of early Alzheimer’s disease
Blennow, Kaj; Dubois, Bruno; Fagan, Anne M.; Lewczuk, Piotr; de Leon, Mony J.; Hampel, Harald
2015-01-01
Several potential disease-modifying drugs for Alzheimer’s disease (AD) have failed to show any effect on disease progression in clinical trials, conceivably because the AD subjects are already too advanced to derive clinical benefit from treatment and because diagnosis based on clinical criteria alone introduces a high misdiagnosis rate. Thus, well-validated biomarkers for early detection and accurate diagnosis are crucial. Low cerebrospinal fluid (CSF) concentrations of the amyloid-β (Aβ1-42) peptide, in combination with high total tau and phosphorylated tau, are sensitive and specific biomarkers highly predictive of progression to AD dementia in patients with mild cognitive impairment. However, interlaboratory variations in the results seen with currently available immunoassays are of concern. Recent worldwide standardization efforts and quality control programs include standard operating procedures for both preanalytical (e.g., lumbar puncture and sample handling) and analytical (e.g., preparation of calibration curve) procedures. Efforts are also ongoing to develop highly reproducible assays on fully automated instruments. These global standardization and harmonization measures will provide the basis for the generalized international application of CSF bio-markers for both clinical trials and routine clinical diagnosis of AD. PMID:24795085
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Lippi, Giuseppe; Plebani, Mario; Favaloro, Emmanuel J
2015-04-01
The reality of laboratory diagnostics as a whole, and hemostasis testing in particular, is evolving under new paradigms of efficiency. The driving forces of health care and laboratory diagnostics in the third millennium are mainly represented by macro- and microeconomics. In a world with limited resources, shattered by an unprecedented economic crisis, laboratory diagnostics is undergoing a substantial reorganization, with emergence of new models under the imperative of terms, such as bedside testing, consolidation, and networking. The paradigms under which these changes are being developed include a variety of environment, preanalytical, technological, professional, and health-care aspects. The maintenance of continued quality is indeed the major challenge to be faced in the foreseeable future. In fact, some challenges prepotently emerge during a consolidation process, which basically involve delayed testing, centrifugation, transportation, and stability of the specimens, as well as the potential mismatch of sample matrix. This article is aimed to provide an overview of the current economic scenario of laboratory diagnostics and discuss the changing face of hemostasis testing in modern laboratories, providing a synthetic overview about potential drawbacks of actualized solutions. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
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Quality and safety aspects in histopathology laboratory
Adyanthaya, Soniya; Jose, Maji
2013-01-01
Histopathology is an art of analyzing and interpreting the shapes, sizes and architectural patterns of cells and tissues within a given specific clinical background and a science by which the image is placed in the context of knowledge of pathobiology, to arrive at an accurate diagnosis. To function effectively and safely, all the procedures and activities of histopathology laboratory should be evaluated and monitored accurately. In histopathology laboratory, the concept of quality control is applicable to pre-analytical, analytical and post-analytical activities. Ensuring safety of working personnel as well as environment is also highly important. Safety issues that may come up in a histopathology lab are primarily those related to potentially hazardous chemicals, biohazardous materials, accidents linked to the equipment and instrumentation employed and general risks from electrical and fire hazards. This article discusses quality management system which can ensure quality performance in histopathology laboratory. The hazards in pathology laboratories and practical safety measures aimed at controlling the dangers are also discussed with the objective of promoting safety consciousness and the practice of laboratory safety. PMID:24574660
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Quality Assurance in Clinical Chemistry: A Touch of Statistics and A Lot of Common Sense
2016-01-01
Summary Working in laboratories of clinical chemistry, we risk feeling that our personal contribution to quality is small and that statistical models and manufacturers play the major roles. It is seldom sufficiently acknowledged that personal knowledge, skills and common sense are crucial for quality assurance in the interest of patients. The employees, environment and procedures inherent to the laboratory including its interactions with the clients are crucial for the overall result of the total testing chain. As the measurement systems, reagents and procedures are gradually improved, work on the preanalytical, postanalytical and clinical phases is likely to pay the most substantial dividends in accomplishing further quality improvements. This means changing attitudes and behaviour, especially of the users of the laboratory. It requires understanding people and how to engage them in joint improvement processes. We need to use our knowledge and common sense expanded with new skills e.g. from the humanities, management, business and change sciences in order to bring this about together with the users of the laboratory. PMID:28356868
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Key factors influencing the incidence of hemolysis: A critical appraisal of current evidence.
McCaughey, Euan James; Vecellio, Elia; Lake, Rebecca; Li, Ling; Burnett, Leslie; Chesher, Douglas; Braye, Stephen; Mackay, Mark; Gay, Stephanie; Badrick, Tony; Westbrook, Johanna; Georgiou, Andrew
2017-01-01
Hemolysis is a leading cause of pre-analytical laboratory errors. The identification of contributing factors is an important step towards the development of effective practices to reduce and prevent hemolysis. We performed a review of PUBMED, Embase, Medline and CINAHL to identify articles published between January 2000 and August 2016 that identified factors influencing in vitro hemolysis rates. The 40 studies included in this review provide excellent evidence that hemolysis rates are higher in Emergency Departments (EDs), for non-antecubital draws, for specimens drawn using an intravenous catheter compared to venipuncture and for samples transported by pneumatic tube compared to by hand. There is also good evidence that hemolysis rates are higher when specimens are not collected by professional phlebotomists, larger volume specimen tubes are used, specimen tubes are filled less than halfway and tourniquet time is greater than one minute. The results of this review suggest that hospitals and clinical laboratories should consider deploying phlebotomists in EDs, drawing all blood through a venipuncture, using the antecubital region as the optimum blood collection site and transporting specimens by laboratory assistant/other personnel, or if this in not practical, ensuring that pneumatic transport systems are validated, maintained and monitored. Studies also recommend making hemolysis a hospital-wide issue and ensuring high-quality staff training and adherence to standard operating procedures to reduce hemolysis rates. Awareness of the factors that influence hemolysis rates, and adoption of strategies to mitigate these risk factors, is an important step towards creating quality practices to reduce hemolysis rates and improve the quality of patient care.
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Preanalytical management: serum vacuum tubes validation for routine clinical chemistry.
Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Picheth, Geraldo; Guidi, Gian Cesare
2012-01-01
The validation process is essential in accredited clinical laboratories. Aim of this study was to validate five kinds of serum vacuum tubes for routine clinical chemistry laboratory testing. Blood specimens from 100 volunteers in five different serum vacuum tubes (Tube I: VACUETTE, Tube II: LABOR IMPORT, Tube III: S-Monovette, Tube IV: SST and Tube V: SST II) were collected by a single, expert phlebotomist. The routine clinical chemistry tests were analyzed on cobas 6000
module. The significance of the differences between samples was assessed by paired Student's t-test after checking for normality. The level of statistical significance was set at P < 0.005. Finally, the biases from Tube I, Tube II, Tube III, Tube IV and Tube V were compared with the current desirable quality specifications for bias (B), derived from biological variation. Basically, our validation will permit the laboratory or hospital managers to select the brand's vacuum tubes validated according him/her technical or economical reasons, in order to perform the following laboratory tests: glucose, total cholesterol, high density lipoprotein-cholesterol, triglycerides, total protein, albumin, blood urea nitrogen, uric acid, alkaline phosphatise, aspartate aminotransferase, gamma-glutamyltransferase, lactate dehydrogenase, creatine kinase, total bilirubin, direct bilirubin, calcium, iron, sodium and potassium. On the contrary special attention will be required if the laboratory already performs creatinine, amylase, phosphate and magnesium determinations and the quality laboratory manager intend to change the serum tubes. We suggest that laboratory management should both standardize the procedures and frequently evaluate the quality of in vitro diagnostic devices. -
Preanalytical management: serum vacuum tubes validation for routine clinical chemistry
Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Picheth, Geraldo; Guidi, Gian Cesare
2012-01-01
Introduction The validation process is essential in accredited clinical laboratories. Aim of this study was to validate five kinds of serum vacuum tubes for routine clinical chemistry laboratory testing. Materials and methods: Blood specimens from 100 volunteers in five diff erent serum vacuum tubes (Tube I: VACUETTE®, Tube II: LABOR IMPORT®, Tube III: S-Monovette®, Tube IV: SST® and Tube V: SST II®) were collected by a single, expert phlebotomist. The routine clinical chemistry tests were analyzed on cobas® 6000
module. The significance of the diff erences between samples was assessed by paired Student’s t-test after checking for normality. The level of statistical significance was set at P < 0.005. Finally, the biases from Tube I, Tube II, Tube III, Tube IV and Tube V were compared with the current desirable quality specifications for bias (B), derived from biological variation. Results and conclusions: Basically, our validation will permit the laboratory or hospital managers to select the brand’s vacuum tubes validated according him/her technical or economical reasons, in order to perform the following laboratory tests: glucose, total cholesterol, high density lipoprotein-cholesterol, triglycerides, total protein, albumin, blood urea nitrogen, uric acid, alkaline phosphatise, aspartate aminotransferase, gamma-glutamyltransferase, lactate dehydrogenase, creatine kinase, total bilirubin, direct bilirubin, calcium, iron, sodium and potassium. On the contrary special attention will be required if the laboratory already performs creatinine, amylase, phosphate and magnesium determinations and the quality laboratory manager intend to change the serum tubes. We suggest that laboratory management should both standardize the procedures and frequently evaluate the quality of in vitro diagnostic devices. PMID:22838184 -
Guidance for laboratories performing molecular pathology for cancer patients.
Cree, Ian A; Deans, Zandra; Ligtenberg, Marjolijn J L; Normanno, Nicola; Edsjö, Anders; Rouleau, Etienne; Solé, Francesc; Thunnissen, Erik; Timens, Wim; Schuuring, Ed; Dequeker, Elisabeth; Murray, Samuel; Dietel, Manfred; Groenen, Patricia; Van Krieken, J Han
2014-11-01
Molecular testing is becoming an important part of the diagnosis of any patient with cancer. The challenge to laboratories is to meet this need, using reliable methods and processes to ensure that patients receive a timely and accurate report on which their treatment will be based. The aim of this paper is to provide minimum requirements for the management of molecular pathology laboratories. This general guidance should be augmented by the specific guidance available for different tumour types and tests. Preanalytical considerations are important, and careful consideration of the way in which specimens are obtained and reach the laboratory is necessary. Sample receipt and handling follow standard operating procedures, but some alterations may be necessary if molecular testing is to be performed, for instance to control tissue fixation. DNA and RNA extraction can be standardised and should be checked for quality and quantity of output on a regular basis. The choice of analytical method(s) depends on clinical requirements, desired turnaround time, and expertise available. Internal quality control, regular internal audit of the whole testing process, laboratory accreditation, and continual participation in external quality assessment schemes are prerequisites for delivery of a reliable service. A molecular pathology report should accurately convey the information the clinician needs to treat the patient with sufficient information to allow for correct interpretation of the result. Molecular pathology is developing rapidly, and further detailed evidence-based recommendations are required for many of the topics covered here. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
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Lippi, Giuseppe; Cervellin, Gianfranco; Mattiuzzi, Camilla
2013-01-01
Background: A number of preanalytical activities strongly influence sample quality, especially those related to sample collection. Since blood drawing through intravenous catheters is reported as a potential source of erythrocyte injury, we performed a critical review and meta-analysis about the risk of catheter-related hemolysis. Materials and methods: We performed a systematic search on PubMed, Web of Science and Scopus to estimate the risk of spurious hemolysis in blood samples collected from intravenous catheters. A meta-analysis with calculation of Odds ratio (OR) and Relative risk (RR) along with 95% Confidence interval (95% CI) was carried out using random effect mode. Results: Fifteen articles including 17 studies were finally selected. The total number of patients was 14,796 in 13 studies assessing catheter and evacuated tubes versus straight needle and evacuated tubes, and 1251 in 4 studies assessing catheter and evacuated tubes versus catheter and manual aspiration. A significant risk of hemolysis was found in studies assessing catheter and evacuated tubes versus straight needle and evacuated tubes (random effect OR 3.4; 95% CI = 2.9–3.9 and random effect RR 1.07; 95% CI = 1.06–1.08), as well as in studies assessing catheter and evacuated tubes versus catheter and manual aspiration of blood (OR 3.7; 95% CI = 2.7–5.1 and RR 1.32; 95% CI = 1.24–1.40). Conclusions: Sample collection through intravenous catheters is associated with significant higher risk of spurious hemolysis as compared with standard blood drawn by straight needle, and this risk is further amplified when intravenous catheter are associated with primary evacuated blood tubes as compared with manual aspiration. PMID:23894864
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Imoh, Lucius C; Mutale, Mubanga; Parker, Christopher T; Erasmus, Rajiv T; Zemlin, Annalise E
2016-01-01
Introduction Timeliness of laboratory results is crucial to patient care and outcome. Monitoring turnaround times (TAT), especially for emergency tests, is important to measure the effectiveness and efficiency of laboratory services. Laboratory-based clinical audits reveal opportunities for improving quality. Our aim was to identify the most critical steps causing a high TAT for cerebrospinal fluid (CSF) chemistry analysis in our laboratory. Materials and methods A 6-month retrospective audit was performed. The duration of each operational phase across the laboratory work flow was examined. A process-mapping audit trail of 60 randomly selected requests with a high TAT was conducted and reasons for high TAT were tested for significance. Results A total of 1505 CSF chemistry requests were analysed. Transport of samples to the laboratory was primarily responsible for the high average TAT (median TAT = 170 minutes). Labelling accounted for most delays within the laboratory (median TAT = 71 minutes) with most delays occurring after regular work hours (P < 0.05). CSF chemistry requests without the appropriate number of CSF sample tubes were significantly associated with delays in movement of samples from the labelling area to the technologist’s work station (caused by a preference for microbiological testing prior to CSF chemistry). Conclusion A laboratory-based clinical audit identified sample transportation, work shift periods and use of inappropriate CSF sample tubes as drivers of high TAT for CSF chemistry in our laboratory. The results of this audit will be used to change pre-analytical practices in our laboratory with the aim of improving TAT and customer satisfaction. PMID:27346964
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Makubi, Abel N; Meda, Collins; Magesa, Alex; Minja, Peter; Mlalasi, Juliana; Salum, Zubeda; Kweka, Rumisha E; Rwehabura, James; Quaresh, Amrana; Magesa, Pius M; Robert, David; Makani, Julie; Kaaya, Ephata
2012-10-01
In Tanzania, there is paucity of data for monitoring laboratory medicine including haematology. This therefore calls for audits of practices in haematology and blood transfusion in order to provide appraise practice and devise strategies that would result in improved quality of health care services. This descriptive cross-sectional study which audited laboratory practice in haematology and blood transfusion at Muhimbili National Hospital (MNH) aimed at assessing the pre-analytical stage of laboratory investigations including laboratory request forms and handling specimen processing in the haematology laboratory and assessing the chain from donor selection, blood component processing to administration of blood during transfusion. A national standard checklist was used to audit the laboratory request forms (LRF), phlebotomists' practices on handling and assessing the from donor selection to administration 6f blood during transfusion. Both interview and observations were used. A total of 195 LRF were audited and 100% of had incomplete information such as patients' identification numbers, time sample ordered, reason for request, summary of clinical assessment and differential diagnoses. The labelling of specimens was poorly done by phlebotomists/clinicians in 82% of the specimens. Also 65% (132/202) of the blood samples delivered in the haematology laboratory did not contain the recommended volume of blood. There was no laboratory request form specific for ordering blood and there were no guidelines for indication of blood transfusion in the wards/ clinics. The blood transfusion laboratory section was not participating in external quality assessment and the hospital transfusion committee was not in operation. It is recommended that a referral hospital like MNH should have a transfusion committee to provide an active forum to facilitate communication between those involved with transfusion, monitor, coordinate and audit blood transfusion practices as per national guidelines.
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True, Lawrence D
2014-03-01
Paralleling the growth of ever more cost efficient methods to sequence the whole genome in minute fragments of tissue has been the identification of increasingly numerous molecular abnormalities in cancers--mutations, amplifications, insertions and deletions of genes, and patterns of differential gene expression, i.e., overexpression of growth factors and underexpression of tumor suppressor genes. These abnormalities can be translated into assays to be used in clinical decision making. In general terms, the result of such an assay is subject to a large number of variables regarding the characteristics of the available sample, particularities of the used assay, and the interpretation of the results. This review discusses the effects of these variables on assays of tissue-based biomarkers, classified by macromolecule--DNA, RNA (including micro RNA, messenger RNA, long noncoding RNA, protein, and phosphoprotein). Since the majority of clinically applicable biomarkers are immunohistochemically detectable proteins this review focuses on protein biomarkers. However, the principles outlined are mostly applicable to any other analyte. A variety of preanalytical variables impacts on the results obtained, including analyte stability (which is different for different analytes, i.e., DNA, RNA, or protein), period of warm and of cold ischemia, fixation time, tissue processing, sample storage time, and storage conditions. In addition, assay variables play an important role, including reagent specificity (notably but not uniquely an issue concerning antibodies used in immunohistochemistry), technical components of the assay, quantitation, and assay interpretation. Finally, appropriateness of an assay for clinical application is an important issue. Reference is made to publicly available guidelines to improve on biomarker development in general and requirements for clinical use in particular. Strategic goals are formulated in order to improve on the quality of biomarker reporting, including issues of analyte quality, experimental detail, assay efficiency and precision, and assay appropriateness.
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Fourier, Anthony; Portelius, Erik; Zetterberg, Henrik; Blennow, Kaj; Quadrio, Isabelle; Perret-Liaudet, Armand
2015-09-20
A panel of cerebrospinal fluid (CSF) biomarkers including total Tau (t-Tau), phosphorylated Tau protein at residue 181 (p-Tau) and β-amyloid peptides (Aβ42 and Aβ40), is frequently used as an aid in Alzheimer's disease (AD) diagnosis for young patients with cognitive impairment, for predicting prodromal AD in mild cognitive impairment (MCI) subjects, for AD discrimination in atypical clinical phenotypes and for inclusion/exclusion and stratification of patients in clinical trials. Due to variability in absolute levels between laboratories, there is no consensus on medical cut-off value for the CSF AD signature. Thus, for full implementation of this core AD biomarker panel in clinical routine, this issue has to be solved. Variability can be explained both by pre-analytical and analytical factors. For example, the plastic tubes used for CSF collection and storage, the lack of reference material and the variability of the analytical protocols were identified as important sources of variability. The aim of this review is to highlight these pre-analytical and analytical factors and describe efforts done to counteract them in order to establish cut-off values for core CSF AD biomarkers. This review will give the current state of recommendations. Copyright © 2015. Published by Elsevier B.V.
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Zerah, Simone; McMurray, Janet; Bousquet, Bernard; Baum, Hannsjorg; Beastall, Graham H; Blaton, Vic; Cals, Marie-Josèphe; Duchassaing, Danielle; Gaudeau-Toussaint, Marie-Françoise; Harmoinen, Aimo; Hoffmann, Hans; Jansen, Rob T; Kenny, Desmond; Kohse, Klaus P; Köller, Ursula; Gobert, Jean-Gérard; Linget, Christine; Lund, Erik; Nubile, Giuseppe; Opp, Matthias; Pazzagli, Mario; Pinon, Georges; Queralto, José M; Reguengo, Henrique; Rizos, Demetrios; Szekeres, Thomas; Vidaud, Michel; Wallinder, Hans
2006-01-01
The EC4 Syllabus for Postgraduate Training is the basis for the European Register of Specialists in Clinical Chemistry and Laboratory Medicine. The syllabus: Indicates the level of requirements in postgraduate training to harmonise the postgraduate education in the European Union (EU); Indicates the level of content of national training programmes to obtain adequate knowledge and experience; Is approved by all EU societies for clinical chemistry and laboratory medicine. The syllabus is not primarily meant to be a training guide, but on the basis of the overview given (common minimal programme), national societies should formulate programmes that indicate where knowledge and experience is needed. The main points of this programme are: Indicates the level of requirements in postgraduate training to harmonise the postgraduate education in the European Union (EU); Indicates the level of content of national training programmes to obtain adequate knowledge and experience; Is approved by all EU societies for clinical chemistry and laboratory medicine. Knowledge in biochemistry, haematology, immunology, etc.; Pre-analytical conditions; Evaluation of results; Interpretations (post-analytical phase); Laboratory management; and Quality insurance management. The aim of this version of the syllabus is to be in accordance with the Directive of Professional Qualifications published on 30 September 2005. To prepare the common platforms planned in this directive, the disciplines are divided into four categories: Indicates the level of requirements in postgraduate training to harmonise the postgraduate education in the European Union (EU); Indicates the level of content of national training programmes to obtain adequate knowledge and experience; Is approved by all EU societies for clinical chemistry and laboratory medicine. Knowledge in biochemistry, haematology, immunology, etc.; Pre-analytical conditions; Evaluation of results; Interpretations (post-analytical phase); Laboratory management; and Quality insurance management. General chemistry, encompassing biochemistry, endocrinology, chemical (humoral), immunology, toxicology, and therapeutic drug monitoring; Haematology, covering cells, transfusion serology, coagulation, and cellular immunology; Microbiology, involving bacteriology, virology, parasitology, and mycology; Genetics and IVF.
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Truncated cystatin C in cerebrospiral fluid: Technical [corrected] artefact or biological process?
Carrette, Odile; Burkhard, Pierre R; Hughes, Severine; Hochstrasser, Denis F; Sanchez, Jean-Charles
2005-08-01
Cystatin C, a low molecular weight cysteine proteinase inhibitor present in human body fluids at physiological concentrations, is more expressed in cerebrospinal fluid (CSF) than in plasma. Mass spectrometric characterization showed that after 3 months of storage of human CSF at -20 degrees C, cystatin C was cleaved in the peptide bond between R8 and L9 and lost its eight N-termini amino acids, whereas this cleavage did not occur when stored at -80 degrees C. This truncation occurred in all CSF samples studied irrespective of the underlying neurological status, indicating a storage-related artefact rather than a physiological or pathological processing of the protein. These results stress the importance of optimal preanalytical storage conditions of any sample prior to proteomics studies.
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Colour coding for blood collection tube closures - a call for harmonisation.
Simundic, Ana-Maria; Cornes, Michael P; Grankvist, Kjell; Lippi, Giuseppe; Nybo, Mads; Ceriotti, Ferruccio; Theodorsson, Elvar; Panteghini, Mauro
2015-02-01
At least one in 10 patients experience adverse events while receiving hospital care. Many of the errors are related to laboratory diagnostics. Efforts to reduce laboratory errors over recent decades have primarily focused on the measurement process while pre- and post-analytical errors including errors in sampling, reporting and decision-making have received much less attention. Proper sampling and additives to the samples are essential. Tubes and additives are identified not only in writing on the tubes but also by the colour of the tube closures. Unfortunately these colours have not been standardised, running the risk of error when tubes from one manufacturer are replaced by the tubes from another manufacturer that use different colour coding. EFLM therefore supports the worldwide harmonisation of the colour coding for blood collection tube closures and labels in order to reduce the risk of pre-analytical errors and improve the patient safety.
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Improving laboratory results turnaround time by reducing pre analytical phase.
Khalifa, Mohamed; Khalid, Parwaiz
2014-01-01
Laboratory turnaround time is considered one of the most important indicators of work efficiency in hospitals, physicians always need timely results to take effective clinical decisions especially in the emergency department where these results can guide physicians whether to admit patients to the hospital, discharge them home or do further investigations. A retrospective data analysis study was performed to identify the effects of ER and Lab staff training on new routines for sample collection and transportation on the pre-analytical phase of turnaround time. Renal profile tests requested by the ER and performed in 2013 has been selected as a sample, and data about 7,519 tests were retrieved and analyzed to compare turnaround time intervals before and after implementing new routines. Results showed significant time reduction on "Request to Sample Collection" and "Collection to In Lab Delivery" time intervals with less significant improvement on the analytical phase of the turnaround time.
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Evaluation of the appropriate time period between sampling and analyzing for automated urinalysis
Dolscheid-Pommerich, Ramona C.; Klarmann-Schulz, Ute; Conrad, Rupert; Stoffel-Wagner, Birgit; Zur, Berndt
2016-01-01
Introduction Preanalytical specifications for urinalysis must be strictly adhered to avoid false interpretations. Aim of the present study is to examine whether the preanalytical factor ‘time point of analysis’ significantly influences stability of urine samples for urine particle and dipstick analysis. Materials and methods In 321 pathological spontaneous urine samples, urine dipstick (Urisys™2400, Combur-10-Test™strips, Roche Diagnostics, Mannheim, Germany) and particle analysis (UF-1000 i™, Sysmex, Norderstedt, Germany) were performed within 90 min, 120 min and 240 min after urine collection. Results For urine particle analysis, a significant increase in conductivity (120 vs. 90 min: P < 0.001, 240 vs. 90 min: P < 0.001) and a significant decrease in WBC (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), RBC (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), casts (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001) and epithelial cells (120 vs. 90 min P = 0.610, 240 vs. 90 min P = 0.041) were found. There were no significant changes for bacteria. Regarding urine dipstick analysis, misclassification rates between measurements were significant for pH (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), leukocytes (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), nitrite (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), protein (120 vs. 90 min P < 0.001, 240 vs. 90 min P<0.001), ketone (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), blood (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001), specific gravity (120 vs. 90 min P < 0.001, 240 vs. 90 min P < 0.001) and urobilinogen (120 vs. 90 min, P = 0.031). Misclassification rates were not significant for glucose and bilirubin. Conclusion Most parameters critically depend on the time window between sampling and analysis. Our study stresses the importance of adherence to early time points in urinalysis (within 90 min). PMID:26981022
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Piaton, E; Fabre, M; Goubin-Versini, I; Bretz-Grenier, M-F; Courtade-Saïdi, M; Vincent, S; Belleannée, G; Thivolet, F; Boutonnat, J; Debaque, H; Fleury-Feith, J; Vielh, P; Egelé, C; Bellocq, J-P; Michiels, J-F; Cochand-Priollet, B
2016-10-01
Since the guidelines of the International Committee for Standardisation in Haematology (ICSH) in 1984 and those of the European Committee for External Quality Assessment Programmes in Laboratory Medicine (EQALM) in 2004, no leading organisation has published technical recommendations for the preparation of air-dried cytological specimens using May-Grünwald-Giemsa (MGG) staining. Literature data were retrieved using reference books, baseline-published studies, articles extracted from PubMed/Medline and Google Scholar, and online-available industry datasheets. The present review addresses all pre-analytical issues concerning the use of Romanowsky's stains (including MGG) in haematology and non-gynaecological cytopathology. It aims at serving as actualised, best practice recommendations for the proper handling of air-dried cytological specimens. It, therefore, appears complementary to the staining criteria of the non-gynaecological diagnostic cytology handbook edited by the United Kingdom National External Quality Assessment Service (UK-NEQAS) in February 2015. © 2016 John Wiley & Sons Ltd.
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Errors in the Extra-Analytical Phases of Clinical Chemistry Laboratory Testing.
Zemlin, Annalise E
2018-04-01
The total testing process consists of various phases from the pre-preanalytical to the post-postanalytical phase, the so-called brain-to-brain loop. With improvements in analytical techniques and efficient quality control programmes, most laboratory errors now occur in the extra-analytical phases. There has been recent interest in these errors with numerous publications highlighting their effect on service delivery, patient care and cost. This interest has led to the formation of various working groups whose mission is to develop standardized quality indicators which can be used to measure the performance of service of these phases. This will eventually lead to the development of external quality assessment schemes to monitor these phases in agreement with ISO15189:2012 recommendations. This review focuses on potential errors in the extra-analytical phases of clinical chemistry laboratory testing, some of the studies performed to assess the severity and impact of these errors and processes that are in place to address these errors. The aim of this review is to highlight the importance of these errors for the requesting clinician.
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Langlois, Michel R; Wallemacq, Pierre
2009-01-01
To face the economic pressures arising from the current socio-economic conjuncture, hospital laboratories are endangered by an increasing trend towards the outsourcing of clinical laboratory tests to external (mega-) laboratories. This should allow hospitals to meet their economic requirements, but with an increased risk of loss of medical quality and, mid- to long-term, loss of cost effectiveness of healthcare at the national level. To anticipate current developments (economical and technological) that inevitably will affect the future of laboratory medicine, hospital laboratories should be proactive and enhance efficiency, reduce costs by consolidation, integrate into regional networks, and form alliances or partnerships. To create additional value, the core competency of laboratory professionals must be refocused to provide medical knowledge services (consultative support to clinicians) related to in vitro diagnostic testing. To integrate cost-efficiency with medical quality, implementation of a matricial organization - operational vs. biomedical level - could be an interesting approach. This integrated structure should create total quality of laboratory testing, managing the entire medical diagnostic cycle from the pre-preanalytical to post-postanalytical phase.
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Quantitative evaluation of the CEEM soil sampling intercomparison.
Wagner, G; Lischer, P; Theocharopoulos, S; Muntau, H; Desaules, A; Quevauviller, P
2001-01-08
The aim of the CEEM soil project was to compare and to test the soil sampling and sample preparation guidelines used in the member states of the European Union and Switzerland for investigations of background and large-scale contamination of soils, soil monitoring and environmental risk assessments. The results of the comparative evaluation of the sampling guidelines demonstrated that, in soil contamination studies carried out with different sampling strategies and methods, comparable results can hardly be expected. Therefore, a reference database (RDB) was established by the organisers, which acted as a basis for the quantitative comparison of the participants' results. The detected deviations were related to the methodological details of the individual strategies. The comparative evaluation concept consisted of three steps: The first step was a comparison of the participants' samples (which were both centrally and individually analysed) between each other, as well as with the reference data base (RDB) and some given soil quality standards on the level of concentrations present. The comparison was made using the example of the metals cadmium, copper, lead and zinc. As a second step, the absolute and relative deviations between the reference database and the participants' results (both centrally analysed under repeatability conditions) were calculated. The comparability of the samples with the RDB was categorised on four levels. Methods of exploratory statistical analysis were applied to estimate the differential method bias among the participants. The levels of error caused by sampling and sample preparation were compared with those caused by the analytical procedures. As a third step, the methodological profiles of the participants were compiled to concisely describe the different procedures used. They were related to the results to find out the main factors leading to their incomparability. The outcome of this evaluation process was a list of strategies and methods, which are problematic with respect to comparability, and should be standardised and/or specified in order to arrive at representative and comparable results in soil contamination studies throughout Europe. Pre-normative recommendations for harmonising European soil sampling guidelines and standard operating procedures have been outlined in Wagner G, Desules A, Muntau H, Theocharopoulos S. Comparative Evaluation of European Methods for Sampling and Sample Preparation of Soils for Inorganic Analysis (CEEM Soil). Final Report of the Contract SMT4-CT96-2085, Sci Total Environ 2001;264:181-186. Wagner G, Desaules A, Munatu H. Theocharopolous S, Quevauvaller Ph. Suggestions for harmonising sampling and sample pre-treatment procedures and improving quality assurance in pre-analytical steps of soil contamination studies. Paper 1.7 Sci Total Environ 2001b;264:103-118.
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Abdel Massih, M; Planchon, V; Polet, M; Dierick, K; Mahillon, J
2016-02-01
Based on the results of 19 food microbiology proficiency testing (PT) schemes, this study aimed to assess the laboratory performances, to highlight the main sources of unsatisfactory analytical results and to suggest areas of improvement. The 2009-2015 results of REQUASUD and IPH PT, involving a total of 48 laboratories, were analysed. On average, the laboratories failed to detect or enumerate foodborne pathogens in 3·0% of the tests. Thanks to a close collaboration with the PT participants, the causes of outliers could be identified in 74% of the cases. The main causes of erroneous PT results were either pre-analytical (handling of the samples, timing of analysis), analytical (unsuitable methods, confusion of samples, errors in colony counting or confirmation) or postanalytical mistakes (calculation and encoding of results). PT schemes are a privileged observation post to highlight analytical problems, which would otherwise remain unnoticed. In this perspective, this comprehensive study of PT results provides insight into the sources of systematic errors encountered during the analyses. This study draws the attention of the laboratories to the main causes of analytical errors and suggests practical solutions to avoid them, in an educational purpose. The observations support the hypothesis that regular participation to PT, when followed by feed-back and appropriate corrective actions, can play a key role in quality improvement and provide more confidence in the laboratory testing results. © 2015 The Society for Applied Microbiology.
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Peptidomics of urine and other biofluids for cancer diagnostics.
Bauça, Josep Miquel; Martínez-Morillo, Eduardo; Diamandis, Eleftherios P
2014-08-01
Cancer is a leading cause of death worldwide. The low diagnostic sensitivity and specificity of most current cancer biomarkers make early cancer diagnosis a challenging task. The comprehensive study of peptides and small proteins in a living system, known as "peptidomics," represents an alternative technological approach to the discovery of potential biomarkers for the assessment of a wide variety of pathologies. This review examines the current status of peptidomics for several body fluids, with a focus on urine, for cancer diagnostics applications. Several studies have used high-throughput technologies to characterize the peptide content of different body fluids. Because of its noninvasive collection and high stability, urine is a valuable source of candidate cancer biomarkers. A wide variety of preanalytical issues concerning patient selection and sample handling need to be considered, because not doing so can affect the quality of the results by introducing bias and artifacts. Optimization of both the analytical strategies and the processing of bioinformatics data is also essential to minimize the false-discovery rate. Peptidomics-based studies of urine and other body fluids have yielded a number of biomolecules and peptide panels with potential for diagnosing different types of cancer, especially of the ovary, prostate, and bladder. Large-scale studies are needed to validate these molecules as cancer biomarkers. © 2013 American Association for Clinical Chemistry.
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"Bed Side" Human Milk Analysis in the Neonatal Intensive Care Unit: A Systematic Review.
Fusch, Gerhard; Kwan, Celia; Kotrri, Gynter; Fusch, Christoph
2017-03-01
Human milk analyzers can measure macronutrient content in native breast milk to tailor adequate supplementation with fortifiers. This article reviews all studies using milk analyzers, including (i) evaluation of devices, (ii) the impact of different conditions on the macronutrient analysis of human milk, and (iii) clinical trials to improve growth. Results lack consistency, potentially due to systematic errors in the validation of the device, or pre-analytical sample preparation errors like homogenization. It is crucial to introduce good laboratory and clinical practice when using these devices; otherwise a non-validated clinical usage can severely affect growth outcomes of infants. Copyright © 2016 Elsevier Inc. All rights reserved.
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The Da Vinci European BioBank: A Metabolomics-Driven Infrastructure
Carotenuto, Dario; Luchinat, Claudio; Marcon, Giordana; Rosato, Antonio; Turano, Paola
2015-01-01
We present here the organization of the recently-constituted da Vinci European BioBank (daVEB, https://www.davincieuropeanbiobank.org/it). The biobank was created as an infrastructure to support the activities of the Fiorgen Foundation (http://www.fiorgen.net/), a nonprofit organization that promotes research in the field of pharmacogenomics and personalized medicine. The way operating procedures concerning samples and data have been developed at daVEB largely stems from the strong metabolomics connotation of Fiorgen and from the involvement of the scientific collaborators of the foundation in international/European projects aimed to tackle the standardization of pre-analytical procedures and the promotion of data standards in metabolomics. PMID:25913579
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Quality specification in haematology: the automated blood cell count.
Buttarello, Mauro
2004-08-02
Quality specifications for automated blood cell counts include topics that go beyond the traditional analytic stage (imprecision, inaccuracy, quality control) and extend to pre- and post-analytic phases. In this review pre-analytic aspects concerning the choice of anticoagulants, maximum conservation times and differences between storage at room temperature or at 4 degrees C are considered. For the analytic phase, goals for imprecision and bias obtained with various approaches (ratio to biologic variation, state of the art, specific clinical situations) are evaluated. For the post-analytic phase, medical review criteria (algorithm, decision limit and delta check) and the structure of the report (general part and comments), which constitutes the formal act through which a laboratory communicates with clinicians, are considered. K2EDTA is considered the anticoagulant of choice for automated cell counts. Regarding storage, specimens should be analyzed as soon as possible. Storage at 4 degrees C may stabilize specimens from 24 to 72 h when complete blood count (CBC) and differential leucocyte count (DLC) is performed. For precision, analytical goals based on the state of the art are acceptable while for bias this is satisfactory only for some parameters. In haematology quality specifications for pre- and analytical phases are important, but the review criteria and the quality of the report play a central role in assuring a definite clinical value.
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Increased instrument intelligence--can it reduce laboratory error?
Jekelis, Albert W
2005-01-01
Recent literature has focused on the reduction of laboratory errors and the potential impact on patient management. This study assessed the intelligent, automated preanalytical process-control abilities in newer generation analyzers as compared with older analyzers and the impact on error reduction. Three generations of immuno-chemistry analyzers were challenged with pooled human serum samples for a 3-week period. One of the three analyzers had an intelligent process of fluidics checks, including bubble detection. Bubbles can cause erroneous results due to incomplete sample aspiration. This variable was chosen because it is the most easily controlled sample defect that can be introduced. Traditionally, lab technicians have had to visually inspect each sample for the presence of bubbles. This is time consuming and introduces the possibility of human error. Instruments with bubble detection may be able to eliminate the human factor and reduce errors associated with the presence of bubbles. Specific samples were vortexed daily to introduce a visible quantity of bubbles, then immediately placed in the daily run. Errors were defined as a reported result greater than three standard deviations below the mean and associated with incomplete sample aspiration of the analyte of the individual analyzer Three standard deviations represented the target limits of proficiency testing. The results of the assays were examined for accuracy and precision. Efficiency, measured as process throughput, was also measured to associate a cost factor and potential impact of the error detection on the overall process. The analyzer performance stratified according to their level of internal process control The older analyzers without bubble detection reported 23 erred results. The newest analyzer with bubble detection reported one specimen incorrectly. The precision and accuracy of the nonvortexed specimens were excellent and acceptable for all three analyzers. No errors were found in the nonvortexed specimens. There were no significant differences in overall process time for any of the analyzers when tests were arranged in an optimal configuration. The analyzer with advanced fluidic intelligence demostrated the greatest ability to appropriately deal with an incomplete aspiration by not processing and reporting a result for the sample. This study suggests that preanalytical process-control capabilities could reduce errors. By association, it implies that similar intelligent process controls could favorably impact the error rate and, in the case of this instrument, do it without negatively impacting process throughput. Other improvements may be realized as a result of having an intelligent error-detection process including further reduction in misreported results, fewer repeats, less operator intervention, and less reagent waste.
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Standardizing in vitro diagnostics tasks in clinical trials: a call for action.
Lippi, Giuseppe; Simundic, Ana-Maria; Rodriguez-Manas, Leocadio; Bossuyt, Patrick; Banfi, Giuseppe
2016-05-01
Translational research is defined as the process of applying ideas, insights and discoveries generated through basic scientific inquiry to treatment or prevention of human diseases. Although precise information is lacking, several lines of evidence attest that up to 95% early-phase studies may not translate into tangible outcomes for improving clinical management. Major theoretical hurdles exist in the translational process, but is it also undeniable that many studies may have failed for practical reasons, such as the use of inappropriate diagnostic testing for evaluating efficacy, effectiveness or safety of a given medical intervention, or poor quality in laboratory testing. This can generate biased test results and result in misconceptions during data interpretation, eventually leading to no clinical benefit, possible harm, and a waste of valuable resources. From a genuine economic perspective, it can be estimated that over 10 million euros of funding may be lost each year in clinical trials in the European Union due to preanalytical and analytical problems. These are mostly attributions to the heterogeneity of current guidelines and recommendations for the testing process, to the poor evidence base for basic pre-analytical, analytical and post-analytical requirements in clinical trials, and to the failure to thoughtfully integrate the perspectives of clinicians, patients, nurses and diagnostic companies in laboratory best practices. The most rational means for filling the gap between what we know and what we practice in clinical trials cannot discount the development of multidisciplinary teams including research scientists, clinicians, nurses, patients associations and representative of in vitro diagnostic (IVD) companies, who should actively interplay and collaborate with laboratory professionals to adapt and disseminate evidence-based recommendations about biospecimen collection and management into the research settings, from preclinical to phase III studies.
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Pre-analytical and analytical aspects affecting clinical reliability of plasma glucose results.
Pasqualetti, Sara; Braga, Federica; Panteghini, Mauro
2017-07-01
The measurement of plasma glucose (PG) plays a central role in recognizing disturbances in carbohydrate metabolism, with established decision limits that are globally accepted. This requires that PG results are reliable and unequivocally valid no matter where they are obtained. To control the pre-analytical variability of PG and prevent in vitro glycolysis, the use of citrate as rapidly effective glycolysis inhibitor has been proposed. However, the commercial availability of several tubes with studies showing different performance has created confusion among users. Moreover, and more importantly, studies have shown that tubes promptly inhibiting glycolysis give PG results that are significantly higher than tubes containing sodium fluoride only, used in the majority of studies generating the current PG cut-points, with a different clinical classification of subjects. From the analytical point of view, to be equivalent among different measuring systems, PG results should be traceable to a recognized higher-order reference via the implementation of an unbroken metrological hierarchy. In doing this, it is important that manufacturers of measuring systems consider the uncertainty accumulated through the different steps of the selected traceability chain. In particular, PG results should fulfil analytical performance specifications defined to fit the intended clinical application. Since PG has tight homeostatic control, its biological variability may be used to define these limits. Alternatively, given the central diagnostic role of the analyte, an outcome model showing the impact of analytical performance of test on clinical classifications of subjects can be used. Using these specifications, performance assessment studies employing commutable control materials with values assigned by reference procedure have shown that the quality of PG measurements is often far from desirable and that problems are exacerbated using point-of-care devices. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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[The biobank of the German National Cohort as a resource for epidemiologic research].
Wichmann, H-Erich; Hörlein, Andreas; Ahrens, Wolfgang; Nauck, Matthias
2016-03-01
The linkage of high-quality biosamples with detailed data from medical examinations, questionnaires and interviews offers great opportunities for research. This is particularly true for large-scale prospective epidemiological studies with long observation periods, like the German National Cohort (GNC). The modalities of collecting, processing and storing biosamples of high quality and with a high throughput, as well as ethical aspects are described using the GNC as an example. For the GNC, 200,000 randomly selected adults will be recruited by 18 study centres and will be followed up for 20-30 years. In addition to the extensive basic examination protocol, followed by reassessment examinations and follow-up questionnaires, the biorepository is a cornerstone of the GNC. The GNC biorepository will comprise more than 20 million aliquots of plasma, serum, erythrocytes, lymphocytes, urine, saliva, nasal swabs and stool. Preanalytics and aliquoting are performed locally in the study centres and are highly standardised and extensively automated. All samples are stored at - 80 and - 180 °C, respectively. A laboratory information system documents all processing steps and storage locations. Access to data and biosamples will be granted to researchers within and outside Germany after completion of the baseline recruitment (i.e. from 2018 onwards). Experience with already existing epidemiological biobanks shows impressive results, especially with regard to genetic research, as well as post-genomics (e.g. transcriptomics, metabolomics, epigenomics). Previous success stories explain the strongly increased demand for data and biosamples from the population. Thus the GNC will provide an important resource for biomedical research in the future.
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Laboratory issues: use of nutritional biomarkers.
Blanck, Heidi Michels; Bowman, Barbara A; Cooper, Gerald R; Myers, Gary L; Miller, Dayton T
2003-03-01
Biomarkers of nutritional status provide alternative measures of dietary intake. Like the error and variation associated with dietary intake measures, the magnitude and impact of both biological (preanalytical) and laboratory (analytical) variability need to be considered when one is using biomarkers. When choosing a biomarker, it is important to understand how it relates to nutritional intake and the specific time frame of exposure it reflects as well as how it is affected by sampling and laboratory procedures. Biological sources of variation that arise from genetic and disease states of an individual affect biomarkers, but they are also affected by nonbiological sources of variation arising from specimen collection and storage, seasonality, time of day, contamination, stability and laboratory quality assurance. When choosing a laboratory for biomarker assessment, researchers should try to make sure random and systematic error is minimized by inclusion of certain techniques such as blinding of laboratory staff to disease status and including external pooled standards to which laboratory staff are blinded. In addition analytic quality control should be ensured by use of internal standards or certified materials over the entire range of possible values to control method accuracy. One must consider the effect of random laboratory error on measurement precision and also understand the method's limit of detection and the laboratory cutpoints. Choosing appropriate cutpoints and reducing error is extremely important in nutritional epidemiology where weak associations are frequent. As part of this review, serum lipids are included as an example of a biomarker whereby collaborative efforts have been put forth to both understand biological sources of variation and standardize laboratory results.
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Davis, Bruce H; Dasgupta, Amar; Kussick, Steven; Han, Jin-Yeong; Estrellado, Annalee
2013-01-01
Flow cytometry and other technologies of cell-based fluorescence assays are as a matter of good laboratory practice required to validate all assays, which when in clinical practice may pass through regulatory review processes using criteria often defined with a soluble analyte in plasma or serum samples in mind. Recently the U.S. Food and Drug Administration (FDA) has entered into a public dialogue in the U.S. regarding their regulatory interest in laboratory developed tests (LDTs) or so-called "home brew" assays performed in clinical laboratories. The absence of well-defined guidelines for validation of cell-based assays using fluorescence detection has thus become a subject of concern for the International Council for Standardization of Haematology (ICSH) and International Clinical Cytometry Society (ICCS). Accordingly, a group of over 40 international experts in the areas of test development, test validation, and clinical practice of a variety of assay types using flow cytometry and/or morphologic image analysis were invited to develop a set of practical guidelines useful to in vitro diagnostic (IVD) innovators, clinical laboratories, regulatory scientists, and laboratory inspectors. The focus of the group was restricted to fluorescence reporter reagents, although some common principles are shared by immunohistochemistry or immunocytochemistry techniques and noted where appropriate. The work product of this two year effort is the content of this special issue of this journal, which is published as 5 separate articles, this being Validation of Cell-based Fluorescence Assays: Practice Guidelines from the ICSH and ICCS - Part II - Preanalytical issues. © 2013 International Clinical Cytometry Society. © 2013 International Clinical Cytometry Society.
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Preanalytical stability of maternal serum markers hCGβ and PAPP-A.
Veyrat, Béatrice; Tosetti, François; Morin, Jean-François; Moineau, Marie-Pierre; Piedimonte, Andrée; Clément, Patrice; Dreux, Sophie; Muller, Françoise
2017-04-01
Down syndrome maternal serum marker screening is based on a risk calculation including the free β - human chorionic gonadotropin (hCGβ) and pregnancy-associated placenta protein type A (PAPP-A). The aim of this study was to define the pre-analytical conditions of stability of these markers both in whole blood at 15-25 ̊C and, after centrifugation, in serum at 4-8 ̊C. 158 patients were included in the study. Two automated workstations were used for assays, Cobas 8000e602, Roche Diagnostics (58 patients tested) and DELFIAXpress, PerkinElmer (100 patients tested). The stability of markers was studied in whole blood (15-25 ̊C) 2, 4, 6 and 8 hours after sampling and in serum stored after centrifugation at 4-8 ̊C at 24, 72 and 120 hours. Variations were defined by (C T - C 2 )/C 2 , C 2 being the marker concentration at 2 hours and C T the concentration at time T. In whole blood kept for 8 hours at 15-25 ̊C, hCGβ increased by a mean 2.4%, whereas the mean increase of PAPP-A was < 1%. In the serum kept for 5 days at 4-8̊C, the mean increase of hCGβ was 4.2%, with no change in PAPP-A. The impact of these variations on risk calculation is low. In conclusion, maternal serum can be store 8 hours at 15-25̊C in whole blood and 5 days at 4-8̊C after centrifugation and serum separation for Down syndrome maternal serum screening.
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Quality Assurance of RNA Expression Profiling in Clinical Laboratories
Tang, Weihua; Hu, Zhiyuan; Muallem, Hind; Gulley, Margaret L.
2012-01-01
RNA expression profiles are increasingly used to diagnose and classify disease, based on expression patterns of as many as several thousand RNAs. To ensure quality of expression profiling services in clinical settings, a standard operating procedure incorporates multiple quality indicators and controls, beginning with preanalytic specimen preparation and proceeding thorough analysis, interpretation, and reporting. Before testing, histopathological examination of each cellular specimen, along with optional cell enrichment procedures, ensures adequacy of the input tissue. Other tactics include endogenous controls to evaluate adequacy of RNA and exogenous or spiked controls to evaluate run- and patient-specific performance of the test system, respectively. Unique aspects of quality assurance for array-based tests include controls for the pertinent outcome signatures that often supersede controls for each individual analyte, built-in redundancy for critical analytes or biochemical pathways, and software-supported scrutiny of abundant data by a laboratory physician who interprets the findings in a manner facilitating appropriate medical intervention. Access to high-quality reagents, instruments, and software from commercial sources promotes standardization and adoption in clinical settings, once an assay is vetted in validation studies as being analytically sound and clinically useful. Careful attention to the well-honed principles of laboratory medicine, along with guidance from government and professional groups on strategies to preserve RNA and manage large data sets, promotes clinical-grade assay performance. PMID:22020152
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Pratumvinit, Busadee; Reesukumal, Kanit; Wongkrajang, Preechaya; Khejonnit, Varanya; Klinbua, Cherdsak; Dangneawnoi, Weerapol
2013-11-15
Acidification of urine has been recommended before testing for calcium, phosphate, and magnesium. We investigated the necessity of pre-analytical acidification in both crystallized and non-crystallized urine samples. From 130 urine samples obtained via routine urine analysis, 65 (50%) samples were classified as non-crystallized. All samples were divided into three groups: untreated samples, acidified samples with HCl, and acidified samples after 1h room-temperature incubation. Urine samples were measured for calcium, phosphate, magnesium, and creatinine using Modular P800 and were examined for crystals using light microscopy. In crystallized samples, acidified samples with 1h incubation had significantly higher Ca/Cr, P/Cr, and Mg/Cr than did untreated samples with mean differences of 0.04, 0.03, and 0.01 mg/mg, respectively (P<0.001). In acidified samples that were analyzed immediately, crystallized samples had lower calcium concentrations than those of acidified samples with 1h incubation and a mean difference of 0.21 mg/dl (P = 0.025). None of the sample differences which exceeded the critical difference of urinary Ca, P and Mg was observed. Acidification of urine should be performed before the measurement of Ca, P, and Mg in the presence of urinary crystals. However, the lack of an acidification process does not result in a clinically significant change. © 2013.
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Zarbo, Richard J; Copeland, Jacqueline R; Varney, Ruan C
2017-10-01
To develop a business subsystem fulfilling International Organization for Standardization 15189 nonconformance management regulatory standard, facilitating employee engagement in problem identification and resolution to effect quality improvement and risk mitigation. From 2012 to 2016, the integrated laboratories of the Henry Ford Health System used a quality technical team to develop and improve a management subsystem designed to identify, track, trend, and summarize nonconformances based on frequency, risk, and root cause for elimination at the level of the work. Programmatic improvements and training resulted in markedly increased documentation culminating in 71,641 deviations in 2016 classified by a taxonomy of 281 defect types into preanalytic (74.8%), analytic (23.6%), and postanalytic (1.6%) testing phases. The top 10 deviations accounted for 55,843 (78%) of the total. Deviation management is a key subsystem of managers' standard work whereby knowledge of nonconformities assists in directing corrective actions and continuous improvements that promote consistent execution and higher levels of performance. © American Society for Clinical Pathology, 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
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Sample normalization methods in quantitative metabolomics.
Wu, Yiman; Li, Liang
2016-01-22
To reveal metabolomic changes caused by a biological event in quantitative metabolomics, it is critical to use an analytical tool that can perform accurate and precise quantification to examine the true concentration differences of individual metabolites found in different samples. A number of steps are involved in metabolomic analysis including pre-analytical work (e.g., sample collection and storage), analytical work (e.g., sample analysis) and data analysis (e.g., feature extraction and quantification). Each one of them can influence the quantitative results significantly and thus should be performed with great care. Among them, the total sample amount or concentration of metabolites can be significantly different from one sample to another. Thus, it is critical to reduce or eliminate the effect of total sample amount variation on quantification of individual metabolites. In this review, we describe the importance of sample normalization in the analytical workflow with a focus on mass spectrometry (MS)-based platforms, discuss a number of methods recently reported in the literature and comment on their applicability in real world metabolomics applications. Sample normalization has been sometimes ignored in metabolomics, partially due to the lack of a convenient means of performing sample normalization. We show that several methods are now available and sample normalization should be performed in quantitative metabolomics where the analyzed samples have significant variations in total sample amounts. Copyright © 2015 Elsevier B.V. All rights reserved.
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Missed diagnostic opportunities within South Africa's early infant diagnosis program, 2010-2015.
Haeri Mazanderani, Ahmad; Moyo, Faith; Sherman, Gayle G
2017-01-01
Samples submitted for HIV PCR testing that fail to yield a positive or negative result represent missed diagnostic opportunities. We describe HIV PCR test rejections and indeterminate results, and the associated delay in diagnosis, within South Africa's early infant diagnosis (EID) program from 2010 to 2015. HIV PCR test data from January 2010 to December 2015 were extracted from the National Health Laboratory Service Corporate Data Warehouse, a central data repository of all registered test-sets within the public health sector in South Africa, by laboratory number, result, date, facility, and testing laboratory. Samples that failed to yield either a positive or negative result were categorized according to the rejection code on the laboratory information system, and descriptive analysis performed using Microsoft Excel. Delay in diagnosis was calculated for patients who had a missed diagnostic opportunity registered between January 2013 and December 2015 by means of a patient linking-algorithm employing demographic details. Between 2010 and 2015, 2 178 582 samples were registered for HIV PCR testing of which 6.2% (n = 134 339) failed to yield either a positive or negative result, decreasing proportionally from 7.0% (n = 20 556) in 2010 to 4.4% (n = 21 388) in 2015 (p<0.001). Amongst 76 972 coded missed diagnostic opportunities, 49 585 (64.4%) were a result of pre-analytical error and 27 387 (35.6%) analytical error. Amongst 49 694 patients searched for follow-up results, 16 895 (34.0%) had at least one subsequent HIV PCR test registered after a median of 29 days (IQR: 13-57), of which 8.4% tested positive compared with 3.6% of all samples submitted for the same period. Routine laboratory data provides the opportunity for near real-time surveillance and quality improvement within the EID program. Delay in diagnosis and wastage of resources associated with missed diagnostic opportunities must be addressed and infants actively followed-up as South Africa works towards elimination of mother-to-child transmission.
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Yang, Chun-Chun; Yang, Stephen Shei-Dei; Hung, Hui-Ching; Chiang, I-Ni; Peng, Chiung-Hui; Chang, Shang-Jen
2017-09-01
To evaluate the ability of laser flow cytometry to predict cocci/mixed growth in the pre-analytical phase of urine specimens. We retrospectively reviewed urine samples from women with uncomplicated urinary tract infections from urologic clinics for study. Urine analyses were performed with laser flow cytometry (UF1000i, Sysmex, Kobe, Japan) and then diagrams were generated (forward scatter vs. fluorescent light scatter). Each specimen (bacteria count >357 BACT/μL) was classified as either cocci bacteria or rods/mixed growth according to the diagrams. Standard urine cultures were performed, and the agreement between cultures and the UF1000i interpretations was analyzed with kappa statistics. Finally, 491 specimens met the criteria for analysis. Among the 376 specimens with single bacteria growth, there were 26 gram-positive cocci (13 Streptococci spp., 7 Staphylococci spp., 6 Enterococci spp.), 1 gram-positive rods (Corynebacterium spp.), and 349 gram-negative rods (273 Escherichia coli, 33 Klebsiella spp., 29 Proteus spp., 6 Citrobacter spp., 4 Enterobacter spp., 3 Pseudomonas spp., and 1 Providencia spp.). There were 115 specimens with two bacteria species or more that were regarded as mixed growth. Agreement of rods or cocci/mixed growth between the laser flow cytometry and urine cultures yielded a kappa value of 0.58. The positive and negative predictive rate of the UF1000i for cocci/mixed growth in voided urine culture was 81.8% and 84.7%, respectively. Through laser flow cytometry, we can predict growth of cocci/mixed growth in the pre-analytical phase of urine culture, thus avoiding unnecessary urine culture and waiting time. © 2016 Wiley Periodicals, Inc.
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Fischer, Andrew H; Schwartz, Mary R; Moriarty, Ann T; Wilbur, David C; Souers, Rhona; Fatheree, Lisa; Booth, Christine N; Clayton, Amy C; Kurtyz, Daniel F I; Padmanabhan, Vijayalakshmi; Crothers, Barbara A
2014-09-01
Immunohistochemistry (IHC) is important for cytology but poses special challenges because preanalytic conditions may differ from the conditions of IHC-positive controls. To broadly survey cytology laboratories to quantify preanalytic platforms for cytology IHC and identify problems with particular platforms or antigens. To discover how validation guidelines for HER2 testing have affected cytology. A voluntary survey of cytology IHC practices was sent to 1899 cytology laboratories participating in the College of American Pathologists Nongynecologic Cytopathology Education Program in the fall of 2009. A total of 818 laboratories (43%) responded to the survey by April 2010. Three hundred fourty-five of 791 respondents (44%) performed IHC on cytology specimens. Seventeen different fixation and processing platforms prior to antibody reaction were reported. A total of 59.2% of laboratories reported differences between the platforms for cytology specimens and positive controls, but most (155 of 184; 84%) did not alter antibody dilutions or antigen retrieval for cytology IHC. When asked to name 2 antibodies for which staining conditions differed between cytology and surgical samples, there were 18 responses listing 14 antibodies. A total of 30.6% of laboratories performing IHC offered HER2 testing before publication of the 2007 College of American Pathologists/American Society of Clinical Oncologists guidelines, compared with 33.6% afterward, with increased performance of testing by reference laboratories. Three laboratories validated a nonformalin HER2 platform. The platforms for cytology IHC and positive controls differ for most laboratories, yet conditions are uncommonly adjusted for cytology specimens. Except for the unsuitability of air-dried smears for HER2 testing, the survey did not reveal evidence of systematic problems with any antibody or platform.
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Paulovich, Amanda G.; Billheimer, Dean; Ham, Amy-Joan L.; Vega-Montoto, Lorenzo; Rudnick, Paul A.; Tabb, David L.; Wang, Pei; Blackman, Ronald K.; Bunk, David M.; Cardasis, Helene L.; Clauser, Karl R.; Kinsinger, Christopher R.; Schilling, Birgit; Tegeler, Tony J.; Variyath, Asokan Mulayath; Wang, Mu; Whiteaker, Jeffrey R.; Zimmerman, Lisa J.; Fenyo, David; Carr, Steven A.; Fisher, Susan J.; Gibson, Bradford W.; Mesri, Mehdi; Neubert, Thomas A.; Regnier, Fred E.; Rodriguez, Henry; Spiegelman, Cliff; Stein, Stephen E.; Tempst, Paul; Liebler, Daniel C.
2010-01-01
Optimal performance of LC-MS/MS platforms is critical to generating high quality proteomics data. Although individual laboratories have developed quality control samples, there is no widely available performance standard of biological complexity (and associated reference data sets) for benchmarking of platform performance for analysis of complex biological proteomes across different laboratories in the community. Individual preparations of the yeast Saccharomyces cerevisiae proteome have been used extensively by laboratories in the proteomics community to characterize LC-MS platform performance. The yeast proteome is uniquely attractive as a performance standard because it is the most extensively characterized complex biological proteome and the only one associated with several large scale studies estimating the abundance of all detectable proteins. In this study, we describe a standard operating protocol for large scale production of the yeast performance standard and offer aliquots to the community through the National Institute of Standards and Technology where the yeast proteome is under development as a certified reference material to meet the long term needs of the community. Using a series of metrics that characterize LC-MS performance, we provide a reference data set demonstrating typical performance of commonly used ion trap instrument platforms in expert laboratories; the results provide a basis for laboratories to benchmark their own performance, to improve upon current methods, and to evaluate new technologies. Additionally, we demonstrate how the yeast reference, spiked with human proteins, can be used to benchmark the power of proteomics platforms for detection of differentially expressed proteins at different levels of concentration in a complex matrix, thereby providing a metric to evaluate and minimize preanalytical and analytical variation in comparative proteomics experiments. PMID:19858499
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Petrides, Athena K; Bixho, Ida; Goonan, Ellen M; Bates, David W; Shaykevich, Shimon; Lipsitz, Stuart R; Landman, Adam B; Tanasijevic, Milenko J; Melanson, Stacy E F
2017-03-01
- A recent government regulation incentivizes implementation of an electronic health record (EHR) with computerized order entry and structured results display. Many institutions have also chosen to interface their EHR with their laboratory information system (LIS). - To determine the impact of an interfaced EHR-LIS on laboratory processes. - We analyzed several different processes before and after implementation of an interfaced EHR-LIS: the turnaround time, the number of stat specimens received, venipunctures per patient per day, preanalytic errors in phlebotomy, the number of add-on tests using a new electronic process, and the number of wrong test codes ordered. Data were gathered through the LIS and/or EHR. - The turnaround time for potassium and hematocrit decreased significantly (P = .047 and P = .004, respectively). The number of stat orders also decreased significantly, from 40% to 7% for potassium and hematocrit, respectively (P < .001 for both). Even though the average number of inpatient venipunctures per day increased from 1.38 to 1.62 (P < .001), the average number of preanalytic errors per month decreased from 2.24 to 0.16 per 1000 specimens (P < .001). Overall there was a 16% increase in add-on tests. The number of wrong test codes ordered was high and it was challenging for providers to correctly order some common tests. - An interfaced EHR-LIS significantly improved within-laboratory turnaround time and decreased stat requests and preanalytic phlebotomy errors. Despite increasing the number of add-on requests, an electronic add-on process increased efficiency and improved provider satisfaction. Laboratories implementing an interfaced EHR-LIS should be cautious of its effects on test ordering and patient venipunctures per day.
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Detection of tetracosactide in plasma by enzyme-linked immunosorbent assay (ELISA).
Martin, Laurent; Chaabo, Ayman; Lasne, Françoise
2015-06-01
As a synthetic analogue of adrenocorticotropic hormone (ACTH), tetracosactide is prohibited in sport by the World Anti-Doping Agency (WADA). An enzyme-linked immunosorbent assay (ELISA) method is proposed for detection of this drug in plasma. Since its structure corresponds to the 24 N-terminal of the 39 amino acids of the natural endogenous peptide ACTH, tetracosactide can be detected with a commercial ELISA kit for ACTH that uses antibodies, the epitopes of which are located in the 1-24 part of ACTH. However, an essential condition for detection specificity is the preliminary total clearance of endogenous ACTH in the plasma samples. This is achieved by a preparative step based on cation-exchange chromatography before ELISA. The method is specific and sensitive (LOD: 30 pg/mL) and may be used as a screening analysis in anti-doping control. The pre-analytical conditions are shown to be of the upmost importance and recommendations for blood collection (EDTA tubes), sample transport (4 °C) and plasma sample storage (-20 °C) are presented. Copyright © 2014 John Wiley & Sons, Ltd.
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42 CFR 493.17 - Test categorization.
Code of Federal Regulations, 2012 CFR
2012-10-01
..., analytic or postanalytic phases of the testing. (2) Training and experience—(i) Score 1. (A) Minimal training is required for preanalytic, analytic and postanalytic phases of the testing process; and (B... necessary for analytic test performance. (3) Reagents and materials preparation—(i) Score 1. (A) Reagents...
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42 CFR 493.17 - Test categorization.
Code of Federal Regulations, 2013 CFR
2013-10-01
..., analytic or postanalytic phases of the testing. (2) Training and experience—(i) Score 1. (A) Minimal training is required for preanalytic, analytic and postanalytic phases of the testing process; and (B... necessary for analytic test performance. (3) Reagents and materials preparation—(i) Score 1. (A) Reagents...
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Clinical and diagnostic utility of saliva as a non-invasive diagnostic fluid: a systematic review
Nunes, Lazaro Alessandro Soares; Mussavira, Sayeeda
2015-01-01
This systematic review presents the latest trends in salivary research and its applications in health and disease. Among the large number of analytes present in saliva, many are affected by diverse physiological and pathological conditions. Further, the non-invasive, easy and cost-effective collection methods prompt an interest in evaluating its diagnostic or prognostic utility. Accumulating data over the past two decades indicates towards the possible utility of saliva to monitor overall health, diagnose and treat various oral or systemic disorders and drug monitoring. Advances in saliva based systems biology has also contributed towards identification of several biomarkers, development of diverse salivary diagnostic kits and other sensitive analytical techniques. However, its utilization should be carefully evaluated in relation to standardization of pre-analytical and analytical variables, such as collection and storage methods, analyte circadian variation, sample recovery, prevention of sample contamination and analytical procedures. In spite of all these challenges, there is an escalating evolution of knowledge with the use of this biological matrix. PMID:26110030
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Privacy and equality in diagnostic genetic testing.
Nyrhinen, Tarja; Hietala, Marja; Puukka, Pauli; Leino-Kilpi, Helena
2007-05-01
This study aimed to determine the extent to which the principles of privacy and equality were observed during diagnostic genetic testing according to views held by patients or child patients' parents (n = 106) and by staff (n = 162) from three Finnish university hospitals. The data were collected through a structured questionnaire and analysed using the SAS 8.1 statistical software. In general, the two principles were observed relatively satisfactorily in clinical practice. According to patients/parents, equality in the post-analytic phase and, according to staff, privacy in the pre-analytic phase, involved the greatest ethical problems. The two groups differed in their views concerning pre-analytic privacy. Although there were no major problems regarding the two principles, the differences between the testing phases require further clarification. To enhance privacy protection and equality, professionals need to be given more genetics/ethics training, and patients individual counselling by genetics units staff, giving more consideration to patients' world-view, the purpose of the test and the test result.
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Galli, Joakim; Oelrich, Johan; Taussig, Michael J.; Andreasson, Ulrika; Ortega-Paino, Eva; Landegren, Ulf
2015-01-01
We report the development of a new database of technology services and products for analysis of biobank samples in biomedical research. BARCdb, the Biobanking Analysis Resource Catalogue (http://www.barcdb.org), is a freely available web resource, listing expertise and molecular resource capabilities of research centres and biotechnology companies. The database is designed for researchers who require information on how to make best use of valuable biospecimens from biobanks and other sample collections, focusing on the choice of analytical techniques and the demands they make on the type of samples, pre-analytical sample preparation and amounts needed. BARCdb has been developed as part of the Swedish biobanking infrastructure (BBMRI.se), but now welcomes submissions from service providers throughout Europe. BARCdb can help match resource providers with potential users, stimulating transnational collaborations and ensuring compatibility of results from different labs. It can promote a more optimal use of European resources in general, both with respect to standard and more experimental technologies, as well as for valuable biobank samples. This article describes how information on service and reagent providers of relevant technologies is made available on BARCdb, and how this resource may contribute to strengthening biomedical research in academia and in the biotechnology and pharmaceutical industries. PMID:25336620
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Post-analytical stability of 23 common chemistry and immunochemistry analytes in incurred samples.
Nielsen, Betina Klint; Frederiksen, Tina; Friis-Hansen, Lennart; Larsen, Pia Bükmann
2017-12-01
Storage of blood samples after centrifugation, decapping and initial sampling allows ordering of additional blood tests. The pre-analytic stability of biochemistry and immunochemistry analytes has been studied in detail, but little is known about the post-analytical stability in incurred samples. We examined the stability of 23 routine analytes on the Dimension Vista® (Siemens Healthineers, Denmark): 42-60 routine samples in lithium-heparin gel tubes (Vacutainer, BD, USA) were centrifuged at 3000×g for 10min. Immediately after centrifugation, initial concentration of analytes were measured in duplicate (t=0). The tubes were stored decapped at room temperature and re-analyzed after 2, 4, 6, 8 and 10h in singletons. The concentration from reanalysis were normalized to initial concentration (t=0). Internal acceptance criteria for bias and total error were used to determine stability of each analyte. Additionally, evaporation from the decapped blood collection tubes and the residual platelet count in the plasma after centrifugation were quantified. We report a post-analytical stability of most routine analytes of ≥8h and do therefore - with few exceptions - suggest a standard 8hour-time limit for reordering and reanalysis of analytes in incurred samples. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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Schuff-Werner, Peter; Steiner, Michael; Fenger, Sebastian; Gross, Hans-Jürgen; Bierlich, Alexa; Dreissiger, Katrin; Mannuß, Steffen; Siegert, Gabriele; Bachem, Maximilian; Kohlschein, Peter
2013-01-01
Pseudothrombocytopenia remains a challenge in the haematological laboratory. The pre-analytical problem that platelets tend to easily aggregate in vitro, giving rise to lower platelet counts, has been known since ethylenediamine-tetra acetic acid EDTA and automated platelet counting procedures were introduced in the haematological laboratory. Different approaches to avoid the time and temperature dependent in vitro aggregation of platelets in the presence of EDTA were tested, but none of them proved optimal for routine purposes. Patients with unexpectedly low platelet counts or flagged for suspected aggregates, were selected and smears were examined for platelet aggregates. In these cases patients were asked to consent to the drawing of an additional sample of blood anti-coagulated with a magnesium additive. Magnesium was used in the beginning of the last century as anticoagulant for microscopic platelet counts. Using this approach, we documented 44 patients with pseudothrombocytopenia. In all cases, platelet counts were markedly higher in samples anti-coagulated with the magnesium containing anticoagulant when compared to EDTA-anticoagulated blood samples. We conclude that in patients with known or suspected pseudothrombocytopenia the magnesium-anticoagulant blood samples may be recommended for platelet counting. PMID:23808903
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Akyar, Işin
2009-10-01
One important trend in the laboratory profession and quality management is the global convergence of laboratory operations. The goal of an accredited medical laboratory is to continue "offering useful laboratory service for diagnosis and treatment of the patients and also aid to the health of the nation". An accredited clinical laboratory is managed by a quality control system, it is competent technically and the laboratory service meets the needs of all its patients and physicians by taking the responsibility of all the medical tests and therapies. For this purpose, ISO 15189 international standard has been prepared by 2003. ISO 15189 standard is originated from the arrangement of ISO 17025 and ISO 9001:2000 standards. Many countries such as England, Germany, France, Canada and Australia have preferred ISO 15189 as their own laboratory accreditation programme, meeting all the requirements of their medical laboratories. The accreditation performance of a clinical microbiology laboratory is mainly based on five essential points; preanalytical, analytical, postanalytical, quality control programmes (internal, external, interlaboratory) and audits (internal, external). In this review article, general concepts on ISO 15189 accreditation standards for the clinical microbiology laboratories have been summarized and the status of a private laboratory (Acibadem LabMed, Istanbul) in Turkey has been discussed.
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Kouri, T T; Gant, V A; Fogazzi, G B; Hofmann, W; Hallander, H O; Guder, W G
2000-07-01
Improved standardized performance is needed because urinalysis continues to be one of the most frequently requested laboratory tests. Since 1997, the European Confederation of Laboratory Medicine (ECLM) has been supporting an interdisciplinary project aiming to produce European urinalysis guidelines. More than seventy clinical chemists, microbiologists and ward-based clinicians, as well as representatives of manufacturers are taking part. These guidelines aim to improve the quality and consistency of chemical urinalysis, particle counting and bacterial culture by suggesting optimal investigative processes that could be applied in Europe. The approach is based on medical needs for urinalysis. The importance of the pre-analytical stage for total quality is stressed by detailed illustrative advice for specimen collection. Attention is also given to emerging automated technology. For cost containment reasons, both optimum (ideal) procedures and minimum analytical approaches are suggested. Since urinalysis mostly lacks genuine reference methods (primary reference measurement procedures; Level 4), a novel classification of the methods is proposed: comparison measurement procedures (Level 3), quantitative routine procedures (Level 2), and ordinal scale examinations (Level 1). Stepwise strategies are suggested to save costs, applying different rules for general and specific patient populations. New analytical quality specifications have been created. After a consultation period, the final written text will be published in full as a separate document.
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Hepburn, Sophie; Cairns, David A; Jackson, David; Craven, Rachel A; Riley, Beverley; Hutchinson, Michelle; Wood, Steven; Smith, Matthew Welberry; Thompson, Douglas; Banks, Rosamonde E
2015-06-01
We have examined the impact of sample processing time delay, temperature, and the addition of protease inhibitors (PIs) on the urinary proteome and peptidome, an important aspect of biomarker studies. Ten urine samples from patients with varying pathologies were each divided and PIs added to one-half, with aliquots of each then processed and frozen immediately, or after a delay of 6 h at 4°C or room temperature (20-22°C), effectively yielding 60 samples in total. Samples were then analyzed by 2D-PAGE, SELDI-TOF-MS, and immunoassay. Interindividual variability in profiles was the dominant feature in all analyses. Minimal changes were observed by 2D-PAGE as a result of delay in processing, temperature, or PIs and no changes were seen in IgG, albumin, β2 -microglobulin, or α1 -microglobulin measured by immunoassay. Analysis of peptides showed clustering of some samples by presence/absence of PIs but the extent was very patient-dependent with most samples showing minimal effects. The extent of processing-induced changes and the benefit of PI addition are patient- and sample-dependent. A consistent processing methodology is essential within a study to avoid any confounding of the results. © 2014 The Authors PROTEOMICS Clinical Applications Published by Wiley-VCH Verlag GmbH & Co. KGaA.
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Lewczuk, Piotr; Riederer, Peter; O'Bryant, Sid E; Verbeek, Marcel M; Dubois, Bruno; Visser, Pieter Jelle; Jellinger, Kurt A; Engelborghs, Sebastiaan; Ramirez, Alfredo; Parnetti, Lucilla; Jack, Clifford R; Teunissen, Charlotte E; Hampel, Harald; Lleó, Alberto; Jessen, Frank; Glodzik, Lidia; de Leon, Mony J; Fagan, Anne M; Molinuevo, José Luis; Jansen, Willemijn J; Winblad, Bengt; Shaw, Leslie M; Andreasson, Ulf; Otto, Markus; Mollenhauer, Brit; Wiltfang, Jens; Turner, Martin R; Zerr, Inga; Handels, Ron; Thompson, Alexander G; Johansson, Gunilla; Ermann, Natalia; Trojanowski, John Q; Karaca, Ilker; Wagner, Holger; Oeckl, Patrick; van Waalwijk van Doorn, Linda; Bjerke, Maria; Kapogiannis, Dimitrios; Kuiperij, H Bea; Farotti, Lucia; Li, Yi; Gordon, Brian A; Epelbaum, Stéphane; Vos, Stephanie J B; Klijn, Catharina J M; Van Nostrand, William E; Minguillon, Carolina; Schmitz, Matthias; Gallo, Carla; Lopez Mato, Andrea; Thibaut, Florence; Lista, Simone; Alcolea, Daniel; Zetterberg, Henrik; Blennow, Kaj; Kornhuber, Johannes
2018-06-01
In the 12 years since the publication of the first Consensus Paper of the WFSBP on biomarkers of neurodegenerative dementias, enormous advancement has taken place in the field, and the Task Force takes now the opportunity to extend and update the original paper. New concepts of Alzheimer's disease (AD) and the conceptual interactions between AD and dementia due to AD were developed, resulting in two sets for diagnostic/research criteria. Procedures for pre-analytical sample handling, biobanking, analyses and post-analytical interpretation of the results were intensively studied and optimised. A global quality control project was introduced to evaluate and monitor the inter-centre variability in measurements with the goal of harmonisation of results. Contexts of use and how to approach candidate biomarkers in biological specimens other than cerebrospinal fluid (CSF), e.g. blood, were precisely defined. Important development was achieved in neuroimaging techniques, including studies comparing amyloid-β positron emission tomography results to fluid-based modalities. Similarly, development in research laboratory technologies, such as ultra-sensitive methods, raises our hopes to further improve analytical and diagnostic accuracy of classic and novel candidate biomarkers. Synergistically, advancement in clinical trials of anti-dementia therapies energises and motivates the efforts to find and optimise the most reliable early diagnostic modalities. Finally, the first studies were published addressing the potential of cost-effectiveness of the biomarkers-based diagnosis of neurodegenerative disorders.
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Cicognola, Claudia; Chiasserini, Davide; Parnetti, Lucilla
2015-01-01
Given the growing use of cerebrospinal fluid (CSF) beta-amyloid (Aβ) and tau as biomarkers for early diagnosis of Alzheimer’s disease (AD), it is essential that the diagnostic procedures are standardized and the results comparable across different laboratories. Preanalytical factors are reported to be the cause of at least 50% of the total variability. Among them, diurnal variability is a key issue and may have an impact on the comparability of the values obtained. The available studies on this issue are not conclusive so far. Fluctuations of CSF biomarkers in young healthy volunteers have been previously reported, while subsequent studies have not confirmed those observations in older subjects, the ones most likely to receive this test. The observed differences in circadian rhythms need to be further assessed not only in classical CSF biomarkers but also in novel forthcoming biomarkers. In this review, the existing data on the issue of diurnal variations of CSF classical biomarkers for AD will be analyzed, also evaluating the available data on new possible biomarkers. PMID:26175714
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Interferences from blood collection tube components on clinical chemistry assays
Bowen, Raffick A.R.; Remaley, Alan T.
2014-01-01
Improper design or use of blood collection devices can adversely affect the accuracy of laboratory test results. Vascular access devices, such as catheters and needles, exert shear forces during blood flow, which creates a predisposition to cell lysis. Components from blood collection tubes, such as stoppers, lubricants, surfactants, and separator gels, can leach into specimens and/or adsorb analytes from a specimen; special tube additives may also alter analyte stability. Because of these interactions with blood specimens, blood collection devices are a potential source of pre-analytical error in laboratory testing. Accurate laboratory testing requires an understanding of the complex interactions between collection devices and blood specimens. Manufacturers, vendors, and clinical laboratorians must consider the pre-analytical challenges in laboratory testing. Although other authors have described the effects of endogenous substances on clinical assay results, the effects/impact of blood collection tube additives and components have not been well systematically described or explained. This review aims to identify and describe blood collection tube additives and their components and the strategies used to minimize their effects on clinical chemistry assays. PMID:24627713
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Platelet Function Tests: Preanalytical Variables, Clinical Utility, Advantages, and Disadvantages.
Hvas, Anne-Mette; Grove, Erik Lerkevang
2017-01-01
Platelet function tests are mainly used in the diagnostic work-up of platelet disorders. During the last decade, the additional use of platelet function tests to evaluate the effect of antiplatelet therapy has also emerged in an attempt to identify patients with an increased risk of arterial thrombosis. Furthermore, platelet function tests are increasingly used to measure residual effect of antiplatelet therapy prior to surgery with the aim of reducing the risk of bleeding. To a limited extend, platelet function tests are also used to evaluate hyperaggregability as a potential marker of a prothrombotic state outside the setting of antiplatelet therapy. This multifaceted use of platelet function tests and the development of simpler point-of-care tests with narrower application have increased the use of platelet function testing and also facilitated the use of platelet function tests outside the highly specialized laboratories. The present chapter describes the preanalytical variables, which should be taken into account when planning platelet function testing. Also, the most widely used platelet function tests are introduced, and their clinical utility and their relative advantages and disadvantages are discussed.
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Casis, E; Garrido, A; Uranga, B; Vives, A; Zufiaurre, C
2001-01-01
Total laboratory automation (TLA) can be substituted in mid-size laboratories by a computer sample workflow control (virtual automation). Such a solution has been implemented in our laboratory using PSM, software developed in cooperation with Roche Diagnostics (Barcelona, Spain), to this purpose. This software is connected to the online analyzers and to the laboratory information system and is able to control and direct the samples working as an intermediate station. The only difference with TLA is the replacement of transport belts by personnel of the laboratory. The implementation of this virtual automation system has allowed us the achievement of the main advantages of TLA: workload increase (64%) with reduction in the cost per test (43%), significant reduction in the number of biochemistry primary tubes (from 8 to 2), less aliquoting (from 600 to 100 samples/day), automation of functional testing, drastic reduction of preanalytical errors (from 11.7 to 0.4% of the tubes) and better total response time for both inpatients (from up to 48 hours to up to 4 hours) and outpatients (from up to 10 days to up to 48 hours). As an additional advantage, virtual automation could be implemented without hardware investment and significant headcount reduction (15% in our lab).
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Rapid Sample Processing for Detection of Food-Borne Pathogens via Cross-Flow Microfiltration
Li, Xuan; Ximenes, Eduardo; Amalaradjou, Mary Anne Roshni; Vibbert, Hunter B.; Foster, Kirk; Jones, Jim; Liu, Xingya; Bhunia, Arun K.
2013-01-01
This paper reports an approach to enable rapid concentration and recovery of bacterial cells from aqueous chicken homogenates as a preanalytical step of detection. This approach includes biochemical pretreatment and prefiltration of food samples and development of an automated cell concentration instrument based on cross-flow microfiltration. A polysulfone hollow-fiber membrane module having a nominal pore size of 0.2 μm constitutes the core of the cell concentration instrument. The aqueous chicken homogenate samples were circulated within the cross-flow system achieving 500- to 1,000-fold concentration of inoculated Salmonella enterica serovar Enteritidis and naturally occurring microbiota with 70% recovery of viable cells as determined by plate counting and quantitative PCR (qPCR) within 35 to 45 min. These steps enabled 10 CFU/ml microorganisms in chicken homogenates or 102 CFU/g chicken to be quantified. Cleaning and sterilizing the instrument and membrane module by stepwise hydraulic and chemical cleaning (sodium hydroxide and ethanol) enabled reuse of the membrane 15 times before replacement. This approach begins to address the critical need for the food industry for detecting food pathogens within 6 h or less. PMID:24014538
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Metabolomic analysis-Addressing NMR and LC-MS related problems in human feces sample preparation.
Moosmang, Simon; Pitscheider, Maria; Sturm, Sonja; Seger, Christoph; Tilg, Herbert; Halabalaki, Maria; Stuppner, Hermann
2017-10-31
Metabolomics is a well-established field in fundamental clinical research with applications in different human body fluids. However, metabolomic investigations in feces are currently an emerging field. Fecal sample preparation is a demanding task due to high complexity and heterogeneity of the matrix. To gain access to the information enclosed in human feces it is necessary to extract the metabolites and make them accessible to analytical platforms like NMR or LC-MS. In this study different pre-analytical parameters and factors were investigated i.e. water content, different extraction solvents, influence of freeze-drying and homogenization, ratios of sample weight to extraction solvent, and their respective impact on metabolite profiles acquired by NMR and LC-MS. The results indicate that profiles are strongly biased by selection of extraction solvent or drying of samples, which causes different metabolites to be lost, under- or overstated. Additionally signal intensity and reproducibility of the measurement were found to be strongly dependent on sample pre-treatment steps: freeze-drying and homogenization lead to improved release of metabolites and thus increased signals, but at the same time induced variations and thus deteriorated reproducibility. We established the first protocol for extraction of human fecal samples and subsequent measurement with both complementary techniques NMR and LC-MS. Copyright © 2017 Elsevier B.V. All rights reserved.
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Neumeister, Veronique M; Anagnostou, Valsamo; Siddiqui, Summar; England, Allison Michal; Zarrella, Elizabeth R; Vassilakopoulou, Maria; Parisi, Fabio; Kluger, Yuval; Hicks, David G; Rimm, David L
2012-12-05
Companion diagnostic tests can depend on accurate measurement of protein expression in tissues. Preanalytic variables, especially cold ischemic time (time from tissue removal to fixation in formalin) can affect the measurement and may cause false-negative results. We examined 23 proteins, including four commonly used breast cancer biomarker proteins, to quantify their sensitivity to cold ischemia in breast cancer tissues. A series of 93 breast cancer specimens with known time-to-fixation represented in a tissue microarray and a second series of 25 matched pairs of core needle biopsies and breast cancer resections were used to evaluate changes in antigenicity as a function of cold ischemic time. Estrogen receptor (ER), progesterone receptor (PgR), HER2 or Ki67, and 19 other antigens were tested. Each antigen was measured using the AQUA method of quantitative immunofluorescence on at least one series. All statistical tests were two-sided. We found no evidence for loss of antigenicity with time-to-fixation for ER, PgR, HER2, or Ki67 in a 4-hour time window. However, with a bootstrapping analysis, we observed a trend toward loss for ER and PgR, a statistically significant loss of antigenicity for phosphorylated tyrosine (P = .0048), and trends toward loss for other proteins. There was evidence of increased antigenicity in acetylated lysine, AKAP13 (P = .009), and HIF1A (P = .046), which are proteins known to be expressed in conditions of hypoxia. The loss of antigenicity for phosphorylated tyrosine and increase in expression of AKAP13, and HIF1A were confirmed in the biopsy/resection series. Key breast cancer biomarkers show no evidence of loss of antigenicity, although this dataset assesses the relatively short time beyond the 1-hour limit in recent guidelines. Other proteins show changes in antigenicity in both directions. Future studies that extend the time range and normalize for heterogeneity will provide more comprehensive information on preanalytic variation due to cold ischemic time.
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Mariani, B; Corbella, M; Seminari, E; Sacco, L; Cambieri, P; Capra Marzani, F; Martino, I F; Bressan, M A; Muzzi, A; Marena, C; Tinelli, C; Marone, P
2018-02-01
Sepsis begins outside of the hospital for nearly 80% of patients and the emergency room (ER) represents the first contact with the health care system. This study evaluates a project to improve collection of blood cultures (BCs) in patients with sepsis in the ER consisting of staff education and completion of the appropriate BC pre-analytical phase. A retrospective observational study performed to analyse the data on BC collection in the ER before and after a three-phase project. The first phase (1 January to 30 June 2015) before the intervention consisted of evaluation of data on BCs routinely collected in the ER. The second phase (1 July to 31 December 2015) was the intervention phase in which educational courses on sepsis recognition and on pre-analytical phase procedures (including direct incubation) were provided to ER staff. The third phase (1 January to 30 June 2016; after the intervention) again consisted of evaluation. Before the intervention, out of 24,738 admissions to the ER, 103 patients (0.4%) were identified as septic and had BCs drawn (359 BC bottles); 19 out of 103 patients (18.4%) had positive BCs. After the intervention, out of 24,702 admissions, 313 patients (1.3%) had BCs drawn (1,242 bottles); of these, 96 (30.7%) had positive BCs. Comparing the first and third periods, an increase in the percentage of patients with BCs collected (from 0.4% to 1.3% respectively, p < 0.0001) and an increase in the percentages of patients with true-positive BCs (from 0.08% to 0.39% of all patients evaluated respectively, p < 0.0001) were observed. The isolation of bacteria by BCs increased 3.25-fold after project implementation. These results can be principally ascribed to an improved awareness of sepsis in the staff associated with improved pre-analytical phase procedures in BC collection.
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Pantanowitz, Liron; Liu, Chi; Huang, Yue; Guo, Huazhang; Rohde, Gustavo K
2017-01-01
The quality of data obtained from image analysis can be directly affected by several preanalytical (e.g., staining, image acquisition), analytical (e.g., algorithm, region of interest [ROI]), and postanalytical (e.g., computer processing) variables. Whole-slide scanners generate digital images that may vary depending on the type of scanner and device settings. Our goal was to evaluate the impact of altering brightness, contrast, compression, and blurring on image analysis data quality. Slides from 55 patients with invasive breast carcinoma were digitized to include a spectrum of human epidermal growth factor receptor 2 (HER2) scores analyzed with Visiopharm (30 cases with score 0, 10 with 1+, 5 with 2+, and 10 with 3+). For all images, an ROI was selected and four parameters (brightness, contrast, JPEG2000 compression, out-of-focus blurring) then serially adjusted. HER2 scores were obtained for each altered image. HER2 scores decreased with increased illumination, higher compression ratios, and increased blurring. HER2 scores increased with greater contrast. Cases with HER2 score 0 were least affected by image adjustments. This experiment shows that variations in image brightness, contrast, compression, and blurring can have major influences on image analysis results. Such changes can result in under- or over-scoring with image algorithms. Standardization of image analysis is recommended to minimize the undesirable impact such variations may have on data output.
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Nutrigenomics, beta-cell function and type 2 diabetes.
Nino-Fong, R; Collins, Tm; Chan, Cb
2007-03-01
The present investigation was designed to investigate the accuracy and precision of lactate measurement obtained with contemporary biosensors (Chiron Diagnostics, Nova Biomedical) and standard enzymatic photometric procedures (Sigma Diagnostics, Abbott Laboratories, Analyticon). Measurements were performed in vitro before and after the stepwise addition of 1 molar sodium lactate solution to samples of fresh frozen plasma to systematically achieve lactate concentrations of up to 20 mmol/l. Precision of the methods investigated varied between 1% and 7%, accuracy ranged between 2% and -33% with the variability being lowest in the Sigma photometric procedure (6%) and more than 13% in both biosensor methods. Biosensors for lactate measurement provide adequate accuracy in mean with the limitation of highly variable results. A true lactate value of 6 mmol/l was found to be presented between 4.4 and 7.6 mmol/l or even with higher difference. Biosensors and standard enzymatic photometric procedures are only limited comparable because the differences between paired determinations presented to be several mmol. The advantage of biosensors is the complete lack of preanalytical sample preparation which appeared to be the major limitation of standard photometry methods.
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Immunohistochemistry for predictive biomarkers in non-small cell lung cancer.
Mino-Kenudson, Mari
2017-10-01
In the era of targeted therapy, predictive biomarker testing has become increasingly important for non-small cell lung cancer. Of multiple predictive biomarker testing methods, immunohistochemistry (IHC) is widely available and technically less challenging, can provide clinically meaningful results with a rapid turn-around-time and is more cost efficient than molecular platforms. In fact, several IHC assays for predictive biomarkers have already been implemented in routine pathology practice. In this review, we will discuss: (I) the details of anaplastic lymphoma kinase (ALK) and proto-oncogene tyrosine-protein kinase ROS (ROS1) IHC assays including the performance of multiple antibody clones, pros and cons of IHC platforms and various scoring systems to design an optimal algorithm for predictive biomarker testing; (II) issues associated with programmed death-ligand 1 (PD-L1) IHC assays; (III) appropriate pre-analytical tissue handling and selection of optimal tissue samples for predictive biomarker IHC.
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Immunohistochemistry for predictive biomarkers in non-small cell lung cancer
2017-01-01
In the era of targeted therapy, predictive biomarker testing has become increasingly important for non-small cell lung cancer. Of multiple predictive biomarker testing methods, immunohistochemistry (IHC) is widely available and technically less challenging, can provide clinically meaningful results with a rapid turn-around-time and is more cost efficient than molecular platforms. In fact, several IHC assays for predictive biomarkers have already been implemented in routine pathology practice. In this review, we will discuss: (I) the details of anaplastic lymphoma kinase (ALK) and proto-oncogene tyrosine-protein kinase ROS (ROS1) IHC assays including the performance of multiple antibody clones, pros and cons of IHC platforms and various scoring systems to design an optimal algorithm for predictive biomarker testing; (II) issues associated with programmed death-ligand 1 (PD-L1) IHC assays; (III) appropriate pre-analytical tissue handling and selection of optimal tissue samples for predictive biomarker IHC. PMID:29114473
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Cuq, Benoît; Blois, Shauna L; Wood, R Darren; Monteith, Gabrielle; Abrams-Ogg, Anthony C; Bédard, Christian; Wood, Geoffrey A
2018-06-01
Thrombin plays a central role in hemostasis and thrombosis. Calibrated automated thrombography (CAT), a thrombin generation assay, may be a useful test for hemostatic disorders in dogs. To describe CAT results in a group of healthy dogs, and assess preanalytical variables and biological variability. Forty healthy dogs were enrolled. Lag time (Lag), time to peak (ttpeak), peak thrombin generation (peak), and endogenous thrombin potential (ETP) were measured. Direct jugular venipuncture and winged-needle catheter-assisted saphenous venipuncture were used to collect samples from each dog, and results were compared between methods. Sample stability at -80°C was assessed over 12 months in a subset of samples. Biological variability of CAT was assessed via nested ANOVA using samples obtained weekly from a subset of 9 dogs for 4 consecutive weeks. Samples for CAT were stable at -80°C over 12 months of storage. Samples collected via winged-needle catheter venipuncture showed poor repeatability compared to direct venipuncture samples; there was also poor agreement between the 2 sampling methods. Intra-individual variability of CAT parameters was below 25%; inter-individual variability ranged from 36.9% to 78.5%. Measurement of thrombin generation using CAT appears to be repeatable in healthy dogs, and samples are stable for at least 12 months when stored at -80°C. Direct venipuncture sampling is recommended for CAT. Low indices of individuality suggest that subject-based reference intervals are more suitable when interpreting CAT results. © 2018 American Society for Veterinary Clinical Pathology.
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Code of Federal Regulations, 2011 CFR
2011-10-01
... issued a certificate of accreditation, must permit CMS or a CMS agent to conduct validation and complaint inspections. (b) General requirements. As part of the inspection process, CMS or a CMS agent may require the... testing process (preanalytic, analytic, and postanalytic). (4) Permit CMS or a CMS agent access to all...
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Code of Federal Regulations, 2012 CFR
2012-10-01
... issued a certificate of accreditation, must permit CMS or a CMS agent to conduct validation and complaint inspections. (b) General requirements. As part of the inspection process, CMS or a CMS agent may require the... testing process (preanalytic, analytic, and postanalytic). (4) Permit CMS or a CMS agent access to all...
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Code of Federal Regulations, 2013 CFR
2013-10-01
... issued a certificate of accreditation, must permit CMS or a CMS agent to conduct validation and complaint inspections. (b) General requirements. As part of the inspection process, CMS or a CMS agent may require the... testing process (preanalytic, analytic, and postanalytic). (4) Permit CMS or a CMS agent access to all...
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Code of Federal Regulations, 2014 CFR
2014-10-01
... issued a certificate of accreditation, must permit CMS or a CMS agent to conduct validation and complaint inspections. (b) General requirements. As part of the inspection process, CMS or a CMS agent may require the... testing process (preanalytic, analytic, and postanalytic). (4) Permit CMS or a CMS agent access to all...
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Code of Federal Regulations, 2010 CFR
2010-10-01
... issued a certificate of accreditation, must permit CMS or a CMS agent to conduct validation and complaint inspections. (b) General requirements. As part of the inspection process, CMS or a CMS agent may require the... testing process (preanalytic, analytic, and postanalytic). (4) Permit CMS or a CMS agent access to all...
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Hsu, Yen-Michael S; Burnham, Carey-Ann D
2014-06-01
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a tool for identifying clinically relevant anaerobes. We evaluated the analytical performance characteristics of the Bruker Microflex with Biotyper 3.0 software system for identification of anaerobes and examined the impact of direct formic acid (FA) treatment and other pre-analytical factors on MALDI-TOF MS performance. A collection of 101 anaerobic bacteria were evaluated, including Clostridium spp., Propionibacterium spp., Fusobacterium spp., Bacteroides spp., and other anaerobic bacterial of clinical relevance. The results of our study indicate that an on-target extraction with 100% FA improves the rate of accurate identification without introducing misidentification (P<0.05). In addition, we modify the reporting cutoffs for the Biotyper "score" yielding acceptable identification. We found that a score of ≥1.700 can maximize the rate of identification. Of interest, MALDI-TOF MS can correctly identify anaerobes grown in suboptimal conditions, such as on selective culture media and following oxygen exposure. In conclusion, we report on a number of simple and cost-effective pre- and post-analytical modifications could enhance MALDI-TOF MS identification for anaerobic bacteria. Copyright © 2014 Elsevier Inc. All rights reserved.
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Lee, Chi-Ching; Chen, Yi-Ping Phoebe; Yao, Tzu-Jung; Ma, Cheng-Yu; Lo, Wei-Cheng; Lyu, Ping-Chiang; Tang, Chuan Yi
2013-04-10
Sequencing of microbial genomes is important because of microbial-carrying antibiotic and pathogenetic activities. However, even with the help of new assembling software, finishing a whole genome is a time-consuming task. In most bacteria, pathogenetic or antibiotic genes are carried in genomic islands. Therefore, a quick genomic island (GI) prediction method is useful for ongoing sequencing genomes. In this work, we built a Web server called GI-POP (http://gipop.life.nthu.edu.tw) which integrates a sequence assembling tool, a functional annotation pipeline, and a high-performance GI predicting module, in a support vector machine (SVM)-based method called genomic island genomic profile scanning (GI-GPS). The draft genomes of the ongoing genome projects in contigs or scaffolds can be submitted to our Web server, and it provides the functional annotation and highly probable GI-predicting results. GI-POP is a comprehensive annotation Web server designed for ongoing genome project analysis. Researchers can perform annotation and obtain pre-analytic information include possible GIs, coding/non-coding sequences and functional analysis from their draft genomes. This pre-analytic system can provide useful information for finishing a genome sequencing project. Copyright © 2012 Elsevier B.V. All rights reserved.
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Evaluation of two types of swabs for sampling allograft musculoskeletal tissue.
Varettas, Kerry
2015-01-01
Allograft musculoskeletal tissue is commonly sampled by a swab for bioburden screening. To determine if bioburden recovery could be improved at the pre-analytical stage, two swab systems were evaluated: the Amies gel swab and the ESwab. In vitro studies were performed to determine the recovery of each swab system with <100 colony-forming unit of challenge organisms using inoculated swabs and by sampling inoculated femoral heads. The standard culture protocol used in this laboratory was also evaluated after sampling of inoculated femoral heads. A prospective study was performed with both swab systems used in parallel to sample cadaveric allograft musculoskeletal tissue. The challenge organisms could be recovered from the in vitro inoculated studies. The standard culture protocol in this laboratory recovered all challenge organisms from both swab systems. One hundred and six paired Amies and ESwabs were collected from eight cadaveric donors with skin commensals the predominant isolates. The sampling of an inoculated femoral head was included to reflect routine swab sampling practice as was the inclusion of the standard method used in this laboratory. This appears to be the first study to compare Amies gel swabs with ESwabs to sample allograft femoral heads and in a prospective study with cadaveric allograft musculoskeletal tissue. Other comparative studies of swab systems have used a much higher inoculum to mimic an infection; however, sepsis is an exclusion criterion for allograft donors. It was found that the Amies gel swab and ESwab are both suitable sampling devices for bioburden testing of allograft musculoskeletal tissue. © 2014 Royal Australasian College of Surgeons.
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Ngo, Carine; Laé, Marick; Ratour, Julia; Hamel, Frédérique; Taris, Corinne; Caly, Martial; Le Cunff, Annie; Reyal, Fabien; Kirova, Youlia; Pierga, Jean-Yves; Vincent-Salomon, Anne
The implementation of an internal quality control is mandatory to guarantee the accuracy of HER2 status in invasive breast cancers. To evaluate the impact of our quality control assurance on HER2 status results in invasive breast carcinomas from 2008 to 2014. HER2 status was determined by immunohistochemistry as the first-line indication, completed by fluorescence in situ hybridization (FISH) for scores 2+ by immunohistochemistry. Internal quality control of HER2 status relied on the standardization of pre-analytical phases, the use of external controls with a known number of HER2 gene copies determined by FISH and continued monitoring of concordance between immunohistochemistry and FISH. The proportion of HER2-positive cases corresponding to scores 3+ by immunohistochemistry and 2+ amplified by FISH varied from 10.6% to 13.8% (median of 11.3%). The proportion of scores 2+ amplified by FISH varied from 13.3% to 32.7% during period of study. The rate of concordance between FISH and immunohistochemistry for score 0/1+ and 3+ cases were≥97%. Eight among 12 discordant cases were false positive resulting from errors in interpretation of immunohistochemistry (score 2+ instead of 3+). Calibration of immunohistochemistry on FISH for HER2 status contributes to limit variability of immunohistochemistry results due to technical issues or interpretation. The implementation of an external control of score 3+ on each slide enables accurate interpretation of score 2+ and 3+ by immunohistochemistry. Copyright © 2017 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.
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Rizk, Mostafa M; Zaki, Adel; Hossam, Nermine; Aboul-Ela, Yasmin
2014-12-01
The performance of clinical laboratories plays a fundamental role in the quality and effectiveness of healthcare. To evaluate the laboratory performance in Alexandria University Hospital Clinical Laboratories using key quality indicators and to compare the performance before and after an improvement plan based on ISO 15189 standards. The study was carried out on inpatient samples for a period of 7 months that was divided into three phases: phase I included data collection for evaluation of the existing process before improvement (March-May 2012); an intermediate phase, which included corrective, preventive action, quality initiative and steps for improvement (June 2012); and phase II, which included data collection for evaluation of the process after improvement (July 2012-September 2012). In terms of the preanalytical indicators, incomplete request forms in phase I showed that the total number of received requests were 31 944, with a percentage of defected request of 33.66%; whereas in phase II, there was a significant reduction in all defected request items (P<0.001) with a percentage of defected requests of 9.64%. As for the analytical indicators, the proficiency testing accuracy score in phase I showed poor performance of 10 analytes in which total error (TE) exceeded total error allowable (TEa), with a corresponding sigma value of less than 3, which indicates test problems and an unreliable method. The remaining analytes showed an acceptable performance in which TE did not exceed the TEa, with a sigma value of more than 6. Following an intervention of 3 months, the performance showed marked improvement. Error tracking in phase I showed a TE of (5.11%), whereas in phase II it was reduced to 2.48% (P<0.001).For the postanalytical indicators, our results in phase I showed that the percentage of nonreported critical results was 26.07%. In phase II, there was a significant improvement (P<0.001). The percentage of nonreported results was 11.37%, the reasons were either inability to contact the authorized doctor (8.24%), wrong patient identification (1.0%), lack of reporting by lab doctor (1.11%), and finally, lack of reporting by the lab technician (1.03%). Standardization and monitoring of each step in the total testing process is very important and is associated with the most efficient and well-organized laboratories.
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Kruse, Niels; Persson, Staffan; Alcolea, Daniel; Bahl, Justyna M C; Baldeiras, Ines; Capello, Elisabetta; Chiasserini, Davide; Bocchio Chiavetto, Luisella; Emersic, Andreja; Engelborghs, Sebastiaan; Eren, Erden; Fladby, Tormod; Frisoni, Giovanni; García-Ayllón, María-Salud; Genc, Sermin; Gkatzima, Olymbia; Heegaard, Niels H H; Janeiro, André M; Kováčech, Branislav; Kuiperij, H Bea; Leitão, Maria J; Lleó, Alberto; Martins, Madalena; Matos, Mafalda; Mollergard, Hanne M; Nobili, Flavio; Öhrfelt, Annika; Parnetti, Lucilla; de Oliveira, Catarina Resende; Rot, Uros; Sáez-Valero, Javier; Struyfs, Hanne; Tanassi, Julia T; Taylor, Peggy; Tsolaki, Magda; Vanmechelen, Eugeen; Verbeek, Marcel M; Zilka, Norbert; Blennow, Kaj; Zetterberg, Henrik; Mollenhauer, Brit
2015-09-01
Decreased levels of alpha-synuclein (aSyn) in cerebrospinal fluid (CSF) in Parkinson's disease and related synucleinopathies have been reported, however, not consistently in all cross-sectional studies. To test the performance of one recently released human-specific enzyme-linked immunosorbent assay (ELISA) for the quantification of aSyn in CSF, we carried out a round robin trial with 18 participating laboratories trained in CSF ELISA analyses within the BIOMARKAPD project in the EU Joint Program - Neurodegenerative Disease Research. CSF samples (homogeneous aliquots from pools) and ELISA kits (one lot) were provided centrally and data reported back to one laboratory for data analysis. Our study showed that although factors such as preanalytical sample handling and lot-to-lot variability were minimized by our study design, we identified high variation in absolute values of CSF aSyn even when the same samples and same lots of assays were applied. We further demonstrate that although absolute concentrations differ between laboratories the quantitative results are comparable. With further standardization this assay may become an attractive tool for comparing aSyn measurements in diverse settings. Recommendations for further validation experiments and improvement of the interlaboratory results obtained are given. Copyright © 2015 Elsevier Inc. All rights reserved.
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Cummerow, C; Schwind, P; Spicher, M; Spohn, G; Geisen, C; Seifried, E; Bönig, H
2012-06-01
Transfusion of the 'wrong' stem cell product would almost inevitably be lethal, yet assays to confirm the contents of the product bag, except by checking labels and paperwork, are lacking. To increase the likelihood that a product mix-up would be detected in the transplant center, we developed a simple protocol for extended blood typing and hence, for confirmation of donor/product identity, on a tube segment. Apheresis samples were applied, directly or after erythrocyte enrichment, to commercially available blood typing assays, including lateral flow cards and gel agglutination cards. Without sample modification, low hematocrit and high leukocyte count obviated definitive blood typing. Using the most simple erythrocyte enrichment protocol, that is, centrifugation, reliable blood group analysis became possible with either assay. Other, more cumbersome pre-analytical protocols were also successful but provided no advantage. The preferred method was validated on 100 samples; ABD was correctly identified in 100% of cases. Of the other Rh Ags, all except two 'small e', in both cases in heterozygous individuals, were detected; there were no false positives. A simple, inexpensive point-of-care assay for extended blood typing of apheresis products is available, which can reduce the fatal risk of administering the wrong stem cell product.
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Le Quellec, Sandra; Paris, Mickaël; Nougier, Christophe; Sobas, Frédéric; Rugeri, Lucia; Girard, Sandrine; Bordet, Jean-Claude; Négrier, Claude; Dargaud, Yesim
2017-05-01
Pneumatic tube system (PTS) in hospitals is commonly used for the transport of blood samples to clinical laboratories, as it is rapid and cost-effective. The aim was to compare the effects on haematology samples of a newly acquired ~2km-long PTS that links 2 hospitals with usual transport (non-pneumatic tube system, NPTS). Complete blood cell count, routine coagulation assays, platelet function tests (PFT) with light-transmission aggregometry and global coagulation assays including ROTEM® and thrombin generation assay (TGA) were performed on blood samples from 30 healthy volunteers and 9 healthy volunteers who agreed to take aspirin prior to blood sampling. The turnaround time was reduced by 31% (p<0.001) with the use of PTS. No statistically significant difference was observed for most routine haematology assays including PFT, and ROTEM® analysis. A statistically significant, but not clinically relevant, shortening of the APTT after sample transport by PTS was found (mean±SD: 30s±1.8 vs. 29.5s±2.1 for NPTS). D-dimer levels were 7.4% higher after transport through PTS but were not discordant. A statistically significant increase of thrombin generation was found in both platelet poor- and platelet rich- plasma samples after PTS transport compared to NPTS transport. PTS is suitable for the transport of samples prior to routine haematology assays including PFT, but should not be used for samples intended for thrombin generation measurement. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Markus, Corey; Metz, Michael
2017-04-01
The clinical catchment area for the Metabolic service at the Women's and Children's Hospital in Adelaide, South Australia, covers nearly 2.5millionkm 2 . Care of children with metabolic disorders in these remote areas is assisted from Adelaide, and at times, using plasma ammonia results from laboratories up to 3000km away. There are seven different platforms measuring plasma ammonia within this vast clinical catchment area. Hence, a correlation study was conducted to examine the relationship between plasma ammonia results from the seven different platforms in use throughout central Australia. Multiple aliquots of plasma from remainder EDTA samples for haematological investigations were frozen. Samples were then dispatched on dry ice to the laboratories being correlated. At an agreed date and time correlation samples were thawed and plasma ammonia measured. Passing-Bablok regression analysis showed slopes ranging from 1.00 to 1.10 and y-intercepts ranging from -10μmol/L to 1μmol/L. Despite the absence of a reference method or reference material and troublesome pre-analytical effects in ammonia measurement, plasma ammonia results from the different platforms in general compare well. The study also demonstrates that samples for ammonia measurement can be transported over great distances and still correlate well. Furthermore, a common reference interval for plasma ammonia may be a possibility. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.
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Franek, Jacob; Leibach, Elizabeth K.; Weissfeld, Alice S.; Kraft, Colleen S.; Sautter, Robert L.; Baselski, Vickie; Rodahl, Debra; Peterson, Edward J.; Cornish, Nancy E.
2015-01-01
SUMMARY Background. Urinary tract infection (UTI) in the United States is the most common bacterial infection, and urine cultures often make up the largest portion of workload for a hospital-based microbiology laboratory. Appropriately managing the factors affecting the preanalytic phase of urine culture contributes significantly to the generation of meaningful culture results that ultimately affect patient diagnosis and management. Urine culture contamination can be reduced with proper techniques for urine collection, preservation, storage, and transport, the major factors affecting the preanalytic phase of urine culture. Objectives. The purposes of this review were to identify and evaluate preanalytic practices associated with urine specimens and to assess their impact on the accuracy of urine culture microbiology. Specific practices included collection methods for men, women, and children; preservation of urine samples in boric acid solutions; and the effect of refrigeration on stored urine. Practice efficacy and effectiveness were measured by two parameters: reduction of urine culture contamination and increased accuracy of patient diagnosis. The CDC Laboratory Medicine Best Practices (LMBP) initiative's systematic review method for assessment of quality improvement (QI) practices was employed. Results were then translated into evidence-based practice guidelines. Search strategy. A search of three electronic bibliographic databases (PubMed, SCOPUS, and CINAHL), as well as hand searching of bibliographies from relevant information sources, for English-language articles published between 1965 and 2014 was conducted. Selection criteria. The search contained the following medical subject headings and key text words: urinary tract infections, UTI, urine/analysis, urine/microbiology, urinalysis, specimen handling, preservation, biological, preservation, boric acid, boric acid/borate, refrigeration, storage, time factors, transportation, transport time, time delay, time factor, timing, urine specimen collection, catheters, indwelling, urinary reservoirs, continent, urinary catheterization, intermittent urethral catheterization, clean voided, midstream, Foley, suprapubic, bacteriological techniques, and microbiological techniques. Main results. Both boric acid and refrigeration adequately preserved urine specimens prior to their processing for up to 24 h. Urine held at room temperature for more than 4 h showed overgrowth of both clinically significant and contaminating microorganisms. The overall strength of this body of evidence, however, was rated as low. For urine specimens collected from women, there was no difference in rates of contamination for midstream urine specimens collected with or without cleansing. The overall strength of this evidence was rated as high. The levels of diagnostic accuracy of midstream urine collection with or without cleansing were similar, although the overall strength of this evidence was rated as low. For urine specimens collected from men, there was a reduction in contamination in favor of midstream clean-catch over first-void specimen collection. The strength of this evidence was rated as high. Only one study compared midstream collection with cleansing to midstream collection without cleansing. Results showed no difference in contamination between the two methods of collection. However, imprecision was due largely to the small event size. The diagnostic accuracy of midstream urine collection from men compared to straight catheterization or suprapubic aspiration was high. However, the overall strength of this body of evidence was rated as low. For urine specimens collected from children and infants, the evidence comparing contamination rates for midstream urine collection with cleansing, midstream collection without cleansing, sterile urine bag collection, and diaper collection pointed to larger reductions in the odds of contamination in favor of midstream collection with cleansing over the other methods of collection. This body of evidence was rated as high. The accuracy of diagnosis of urinary tract infection from midstream clean-catch urine specimens, sterile urine bag specimens, or diaper specimens compared to straight catheterization or suprapubic aspiration was varied. Authors' conclusions. No recommendation for or against is made for delayed processing of urine stored at room temperature, refrigerated, or preserved in boric acid. This does not preclude the use of refrigeration or chemical preservatives in clinical practice. It does indicate, however, that more systematic studies evaluating the utility of these measures are needed. If noninvasive collection is being considered for women, midstream collection with cleansing is recommended, but no recommendation for or against is made for midstream collection without cleansing. If noninvasive collection is being considered for men, midstream collection with cleansing is recommended and collection of first-void urine is not recommended. No recommendation for or against is made for collection of midstream urine without cleansing. If noninvasive collection is being considered for children, midstream collection with cleansing is recommended and collection in sterile urine bags, from diapers, or midstream without cleansing is not recommended. Whether midstream collection with cleansing can be routinely used in place of catheterization or suprapubic aspiration is unclear. The data suggest that midstream collection with cleansing is accurate for the diagnosis of urinary tract infections in infants and children and has higher average accuracy than sterile urine bag collection (data for diaper collection were lacking); however, the overall strength of evidence was low, as multivariate modeling could not be performed, and thus no recommendation for or against can be made. PMID:26598386
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Pantanowitz, Liron; Liu, Chi; Huang, Yue; Guo, Huazhang; Rohde, Gustavo K.
2017-01-01
Introduction: The quality of data obtained from image analysis can be directly affected by several preanalytical (e.g., staining, image acquisition), analytical (e.g., algorithm, region of interest [ROI]), and postanalytical (e.g., computer processing) variables. Whole-slide scanners generate digital images that may vary depending on the type of scanner and device settings. Our goal was to evaluate the impact of altering brightness, contrast, compression, and blurring on image analysis data quality. Methods: Slides from 55 patients with invasive breast carcinoma were digitized to include a spectrum of human epidermal growth factor receptor 2 (HER2) scores analyzed with Visiopharm (30 cases with score 0, 10 with 1+, 5 with 2+, and 10 with 3+). For all images, an ROI was selected and four parameters (brightness, contrast, JPEG2000 compression, out-of-focus blurring) then serially adjusted. HER2 scores were obtained for each altered image. Results: HER2 scores decreased with increased illumination, higher compression ratios, and increased blurring. HER2 scores increased with greater contrast. Cases with HER2 score 0 were least affected by image adjustments. Conclusion: This experiment shows that variations in image brightness, contrast, compression, and blurring can have major influences on image analysis results. Such changes can result in under- or over-scoring with image algorithms. Standardization of image analysis is recommended to minimize the undesirable impact such variations may have on data output. PMID:28966838
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A candidate reference method using ICP-MS for sweat chloride quantification.
Collie, Jake T; Massie, R John; Jones, Oliver A H; Morrison, Paul D; Greaves, Ronda F
2016-04-01
The aim of the study was to develop a method for sweat chloride (Cl) quantification using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to present to the Joint Committee for Traceability in Laboratory Medicine (JCTLM) as a candidate reference method for the diagnosis of cystic fibrosis (CF). Calibration standards were prepared from sodium chloride (NaCl) to cover the expected range of sweat Cl values. Germanium (Ge) and scandium (Sc) were selected as on-line (instrument based) internal standards (IS) and gallium (Ga) as the off-line (sample based) IS. The method was validated through linearity, accuracy and imprecision studies as well as enrolment into the Royal College of Pathologists of Australasia Quality Assurance Program (RCPAQAP) for sweat electrolyte testing. Two variations of the ICP-MS method were developed, an on-line and off-line IS, and compared. Linearity was determined up to 225 mmol/L with a limit of quantitation of 7.4 mmol/L. The off-line IS demonstrated increased accuracy through the RCPAQAP performance assessment (CV of 1.9%, bias of 1.5 mmol/L) in comparison to the on-line IS (CV of 8.0%, bias of 3.8 mmol/L). Paired t-tests confirmed no significant differences between sample means of the two IS methods (p=0.53) or from each method against the RCPAQAP target values (p=0.08 and p=0.29). Both on and off-line IS methods generated highly reproducible results and excellent linear comparison to the RCPAQAP target results. ICP-MS is a highly accurate method with a low limit of quantitation for sweat Cl analysis and should be recognised as a candidate reference method for the monitoring and diagnosis of CF. Laboratories that currently practice sweat Cl analysis using ICP-MS should include an off-line IS to help negate any pre-analytical errors.
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Procop, Gary W; Taege, Alan J; Starkey, Colleen; Tungsiripat, Marisa; Warner, Diane; Schold, Jesse D; Yen-Lieberman, Belinda
2017-09-01
The processing of specimens often occurs in a central processing area within laboratories. We demonstrated that plasma centrifuged in the central laboratory but allowed to remain within the primary tube following centrifugation was associated with spuriously elevated HIV viral loads compared with recentrifugation of the plasma just prior to testing. Copyright © 2016 Elsevier Inc. All rights reserved.
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2012-01-01
Background Companion diagnostic tests can depend on accurate measurement of protein expression in tissues. Preanalytic variables, especially cold ischemic time (time from tissue removal to fixation in formalin) can affect the measurement and may cause false-negative results. We examined 23 proteins, including four commonly used breast cancer biomarker proteins, to quantify their sensitivity to cold ischemia in breast cancer tissues. Methods A series of 93 breast cancer specimens with known time-to-fixation represented in a tissue microarray and a second series of 25 matched pairs of core needle biopsies and breast cancer resections were used to evaluate changes in antigenicity as a function of cold ischemic time. Estrogen receptor (ER), progesterone receptor (PgR), HER2 or Ki67, and 19 other antigens were tested. Each antigen was measured using the AQUA method of quantitative immunofluorescence on at least one series. All statistical tests were two-sided. Results We found no evidence for loss of antigenicity with time-to-fixation for ER, PgR, HER2, or Ki67 in a 4-hour time window. However, with a bootstrapping analysis, we observed a trend toward loss for ER and PgR, a statistically significant loss of antigenicity for phosphorylated tyrosine (P = .0048), and trends toward loss for other proteins. There was evidence of increased antigenicity in acetylated lysine, AKAP13 (P = .009), and HIF1A (P = .046), which are proteins known to be expressed in conditions of hypoxia. The loss of antigenicity for phosphorylated tyrosine and increase in expression of AKAP13, and HIF1A were confirmed in the biopsy/resection series. Conclusions Key breast cancer biomarkers show no evidence of loss of antigenicity, although this dataset assesses the relatively short time beyond the 1-hour limit in recent guidelines. Other proteins show changes in antigenicity in both directions. Future studies that extend the time range and normalize for heterogeneity will provide more comprehensive information on preanalytic variation due to cold ischemic time. PMID:23090068
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Niederkofler, Eric E.; Phillips, David A.; Krastins, Bryan; Kulasingam, Vathany; Kiernan, Urban A.; Tubbs, Kemmons A.; Peterman, Scott M.; Prakash, Amol; Diamandis, Eleftherios P.; Lopez, Mary F.; Nedelkov, Dobrin
2013-01-01
Insulin-like growth factor 1 (IGF1) is an important biomarker of human growth disorders that is routinely analyzed in clinical laboratories. Mass spectrometry-based workflows offer a viable alternative to standard IGF1 immunoassays, which utilize various pre-analytical preparation strategies. In this work we developed an assay that incorporates a novel sample preparation method for dissociating IGF1 from its binding proteins. The workflow also includes an immunoaffinity step using antibody-derivatized pipette tips, followed by elution, trypsin digestion, and LC-MS/MS separation and detection of the signature peptides in a selected reaction monitoring (SRM) mode. The resulting quantitative mass spectrometric immunoassay (MSIA) exhibited good linearity in the range of 1 to 1,500 ng/mL IGF1, intra- and inter-assay precision with CVs of less than 10%, and lowest limits of detection of 1 ng/mL. The linearity and recovery characteristics of the assay were also established, and the new method compared to a commercially available immunoassay using a large cohort of human serum samples. The IGF1 SRM MSIA is well suited for use in clinical laboratories. PMID:24278387
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Pitfalls in lung cancer molecular pathology: how to limit them in routine practice?
Ilie, M; Hofman, P
2012-01-01
New treatment options in advanced non-small cell lung carcinoma (NSCLC) targeting activating epidermal growth factor receptor (EGFR) gene mutations and other genetic alterations demonstrated the clinical significance of the molecular features of specific subsets of tumors. Therefore, the development of personalized medicine has stimulated the routine integration into pathology departments of somatic mutation testing. However, clinical mutation testing must be optimized and standardized with regard to histological profile, type of samples, pre-analytical steps, methodology and result reporting. Routine molecular testing in NSCLC is currently moving beyond EGFR mutational analysis. Recent progress of targeted therapies will require molecular testing for a wide panel of mutations for a personalized molecular diagnosis. As a consequence, efficient testing of multiple molecular abnormalities is an urgent requirement in thoracic oncology. Moreover, increasingly limited tumor sample becomes a major challenge for molecular pathology. Continuous efforts should be made for safe, effective and specific molecular analyses. This must be based on close collaboration between the departments involved in the management of lung cancer. In this review we explored the practical issues and pitfalls surrounding the routine implementation of molecular testing in NSCLC in a pathology laboratory.
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Considerations for standardizing predictive molecular pathology for cancer prognosis.
Fiorentino, Michelangelo; Scarpelli, Marina; Lopez-Beltran, Antonio; Cheng, Liang; Montironi, Rodolfo
2017-01-01
Molecular tests that were once ancillary to the core business of cyto-histopathology are becoming the most relevant workload in pathology departments after histopathology/cytopathology and before autopsies. This has resulted from innovations in molecular biology techniques, which have developed at an incredibly fast pace. Areas covered: Most of the current widely used techniques in molecular pathology such as FISH, direct sequencing, pyrosequencing, and allele-specific PCR will be replaced by massive parallel sequencing that will not be considered next generation, but rather, will be considered to be current generation sequencing. The pre-analytical steps of molecular techniques such as DNA extraction or sample preparation will be largely automated. Moreover, all the molecular pathology instruments will be part of an integrated workflow that traces the sample from extraction to the analytical steps until the results are reported; these steps will be guided by expert laboratory information systems. In situ hybridization and immunohistochemistry for quantification will be largely digitalized as much as histology will be mostly digitalized rather than viewed using microscopy. Expert commentary: This review summarizes the technical and regulatory issues concerning the standardization of molecular tests in pathology. A vision of the future perspectives of technological changes is also provided.
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Dukić, Lora; Kopčinović, Lara Milevoj; Dorotić, Adrijana; Baršić, Ivana
2016-10-15
Blood gas analysis (BGA) is exposed to risks of errors caused by improper sampling, transport and storage conditions. The Clinical and Laboratory Standards Institute (CLSI) generated documents with recommendations for avoidance of potential errors caused by sample mishandling. Two main documents related to BGA issued by the CLSI are GP43-A4 (former H11-A4) Procedures for the collection of arterial blood specimens; approved standard - fourth edition, and C46-A2 Blood gas and pH analysis and related measurements; approved guideline - second edition. Practices related to processing of blood gas samples are not standardized in the Republic of Croatia. Each institution has its own protocol for ordering, collection and analysis of blood gases. Although many laboratories use state of the art analyzers, still many preanalytical procedures remain unchanged. The objective of the Croatian Society of Medical Biochemistry and Laboratory Medicine (CSMBLM) is to standardize the procedures for BGA based on CLSI recommendations. The Working Group for Blood Gas Testing as part of the Committee for the Scientific Professional Development of the CSMBLM prepared a set of recommended protocols for sampling, transport, storage and processing of blood gas samples based on relevant CLSI documents, relevant literature search and on the results of Croatian survey study on practices and policies in acid-base testing. Recommendations are intended for laboratory professionals and all healthcare workers involved in blood gas processing.
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Dukić, Lora; Kopčinović, Lara Milevoj; Dorotić, Adrijana; Baršić, Ivana
2016-01-01
Blood gas analysis (BGA) is exposed to risks of errors caused by improper sampling, transport and storage conditions. The Clinical and Laboratory Standards Institute (CLSI) generated documents with recommendations for avoidance of potential errors caused by sample mishandling. Two main documents related to BGA issued by the CLSI are GP43-A4 (former H11-A4) Procedures for the collection of arterial blood specimens; approved standard – fourth edition, and C46-A2 Blood gas and pH analysis and related measurements; approved guideline – second edition. Practices related to processing of blood gas samples are not standardized in the Republic of Croatia. Each institution has its own protocol for ordering, collection and analysis of blood gases. Although many laboratories use state of the art analyzers, still many preanalytical procedures remain unchanged. The objective of the Croatian Society of Medical Biochemistry and Laboratory Medicine (CSMBLM) is to standardize the procedures for BGA based on CLSI recommendations. The Working Group for Blood Gas Testing as part of the Committee for the Scientific Professional Development of the CSMBLM prepared a set of recommended protocols for sampling, transport, storage and processing of blood gas samples based on relevant CLSI documents, relevant literature search and on the results of Croatian survey study on practices and policies in acid-base testing. Recommendations are intended for laboratory professionals and all healthcare workers involved in blood gas processing. PMID:27812301
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Investigations of blood ammonia analysis: Test matrices, storage, and stability.
Goldstein, Brittany N; Wesler, Jordan; Nowacki, Amy S; Reineks, Edmunds; Natowicz, Marvin R
2017-06-01
An assessment of blood ammonia concentration is common medical practice in the evaluation of an individual with an unexplained mental status change or coma. The determination of a blood ammonia level is most commonly done using a glutamate dehydrogenase (GLDH)-based assay, although there are many potential sources of artifact and the literature is inconsistent regarding key preanalytic issues. Using a GLDH-based assay, we first investigated matrix effects using three anticoagulants: heparin, EDTA and oxalate. Heparin-anticoagulated plasma was substantially less precise than EDTA- and oxalate-anticoagulated plasma. Oxalate-anticoagulated plasma showed a greater baseline of apparent ammonia than either heparin- or EDTA-derived plasma, presumably due to interferants. We then evaluated the stability of EDTA-anticoagulated plasma for assessment of ammonia when stored at 4°C,-14°C or -70°C. There was a linear increase of ammonia with storage at both 4°C and -14°C. Plasma kept at -70°C for up to three weeks showed no change in measured ammonia relative to the baseline determination. This work clarifies preanalytic conditions for which a precise determination of ammonia can be accomplished using a GLDH-based assay. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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Penn, Andrew M; Lu, Linghong; Chambers, Andrew G; Balshaw, Robert F; Morrison, Jaclyn L; Votova, Kristine; Wood, Eileen; Smith, Derek S; Lesperance, Maria; del Zoppo, Gregory J; Borchers, Christoph H
2015-12-01
Multiple reaction monitoring mass spectrometry (MRM-MS) is an emerging technology for blood biomarker verification and validation; however, the results may be influenced by pre-analytical factors. This exploratory study was designed to determine if differences in phlebotomy techniques would significantly affect the abundance of plasma proteins in an upcoming biomarker development study. Blood was drawn from 10 healthy participants using four techniques: (1) a 20-gauge IV with vacutainer, (2) a 21-gauge direct vacutainer, (3) an 18-gauge butterfly with vacutainer, and (4) an 18-gauge butterfly with syringe draw. The abundances of a panel of 122 proteins (117 proteins, plus 5 matrix metalloproteinase (MMP) proteins) were targeted by LC/MRM-MS. In addition, complete blood count (CBC) data were also compared across the four techniques. Phlebotomy technique significantly affected 2 of the 11 CBC parameters (red blood cell count, p = 0.010; hemoglobin concentration, p = 0.035) and only 12 of the targeted 117 proteins (p < 0.05). Of the five MMP proteins, only MMP7 was detectable and its concentration was not significantly affected by different techniques. Overall, most proteins in this exploratory study were not significantly influenced by phlebotomy technique; however, a larger study with additional patients will be required for confirmation.
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Blood lipid measurements. Variations and practical utility.
Cooper, G R; Myers, G L; Smith, S J; Schlant, R C
1992-03-25
To describe the magnitude and impact of the major biological and analytical sources of variation in serum lipid and lipoprotein levels on risk of coronary heart disease; to present a way to qualitatively estimate the total intraindividual variation; and to demonstrate how to determine the number of specimens required to estimate, with 95% confidence, the "true" underlying total cholesterol value in the serum of a patient. Representative references on each source of variation were selected from more than 300 reviewed publications, most published within the past 5 years, to document current findings and concepts. Most articles reviewed were in English. Studies on biological sources of variation were selected using the following criteria: representative of published findings, clear statement of either significant or insignificant results, and acquisition of clinical and laboratory data under standardized conditions. Representative results for special populations such as women and children are reported when results differ from those of adult men. References were selected based on acceptable experimental design and use of standardized laboratory lipid measurements. The lipid levels considered representative for a selected source of variation arose from quantitative measurements by a suitably standardized laboratory. Statistical analysis of data was examined to assure reliability. The proposed method of estimating the biological coefficient of variation must be considered to give qualitative results, because only two or three serial specimens are collected in most cases for the estimation. Concern has arisen about the magnitude, impact, and interpretation of preanalytical as well as analytical sources of variation on reported results of lipid measurements of an individual. Preanalytical sources of variation from behavioral, clinical, and sampling sources constitute about 60% of the total variation in a reported lipid measurement of an individual. A technique is presented to allow physicians to qualitatively estimate the intraindividual biological variation of a patient from the results of two or more specimens reported from a standardized laboratory and to determine whether additional specimens are needed to meet the National Cholesterol Education Program recommendation that the intraindividual serum total cholesterol coefficient of variation not exceed 5.0. A National Reference Method Network has been established to help solve analytical problems.
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Point-of-care test (POCT) INR: hope or illusion?
Dusse, Luci Maria Sant'Ana; Oliveira, Nataly Carvalho; Rios, Danyelle Romana Alves; Marcolino, Milena Soriano
2012-01-01
In the last decade, point-of-care tests were developed to provide rapid generation of test results. These tests have increasingly broad applications. In the area of hemostasis, the international normalized ratio, INR point-of-care test (POCT INR), is the main test of this new proposal. This test has great potential benefit in situations where the quick INR results influences clinical decision making, as in acute ischemic stroke, before surgical procedures and during cardiac surgery. The INR POCT has the potential to be used for self-monitoring of oral anticoagulation in patients under anticoagulant therapy. However, the precision and accuracy of INR POCT still need to be enhanced to increase effectiveness and efficiency of the test. Additionally, the RDC / ANVISA Number 302 makes clear that the POCT testing must be supervised by the technical manager of the Clinical Laboratory in the pre-analytical, analytical and post-analytical. In practice, the Clinical Laboratory does not participate in the implementation of POCT testing or release of the results. Clinicians have high expectation with the incorporation of INR POCT in clinical practice, despite the limitations of this method. These professionals are willing to train the patient to perform the test, but are not legally responsible for the quality of it and are not prepared for the maintenance of equipment. The definition of who is in charge for the test must be one to ensure the quality control.
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Selecting automation for the clinical chemistry laboratory.
Melanson, Stacy E F; Lindeman, Neal I; Jarolim, Petr
2007-07-01
Laboratory automation proposes to improve the quality and efficiency of laboratory operations, and may provide a solution to the quality demands and staff shortages faced by today's clinical laboratories. Several vendors offer automation systems in the United States, with both subtle and obvious differences. Arriving at a decision to automate, and the ensuing evaluation of available products, can be time-consuming and challenging. Although considerable discussion concerning the decision to automate has been published, relatively little attention has been paid to the process of evaluating and selecting automation systems. To outline a process for evaluating and selecting automation systems as a reference for laboratories contemplating laboratory automation. Our Clinical Chemistry Laboratory staff recently evaluated all major laboratory automation systems in the United States, with their respective chemistry and immunochemistry analyzers. Our experience is described and organized according to the selection process, the important considerations in clinical chemistry automation, decisions and implementation, and we give conclusions pertaining to this experience. Including the formation of a committee, workflow analysis, submitting a request for proposal, site visits, and making a final decision, the process of selecting chemistry automation took approximately 14 months. We outline important considerations in automation design, preanalytical processing, analyzer selection, postanalytical storage, and data management. Selecting clinical chemistry laboratory automation is a complex, time-consuming process. Laboratories considering laboratory automation may benefit from the concise overview and narrative and tabular suggestions provided.
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Sarkozi, Laszlo; Simson, Elkin; Ramanathan, Lakshmi
2003-03-01
Thirty-six years of data and history of laboratory practice at our institution has enabled us to follow the effects of analytical automation, then recently pre-analytical and post-analytical automation on productivity, cost reduction and enhanced quality of service. In 1998, we began the operation of a pre- and post-analytical automation system (robotics), together with an advanced laboratory information system to process specimens prior to analysis, deliver them to various automated analytical instruments, specimen outlet racks and finally to refrigerated stockyards. By the end of 3 years of continuous operation, we compared the chemistry part of the system with the prior 33 years and quantitated the financial impact of the various stages of automation. Between 1965 and 2000, the Consumer Price Index increased by a factor of 5.5 in the United States. During the same 36 years, at our institution's Chemistry Department the productivity (indicated as the number of reported test results/employee/year) increased from 10,600 to 104,558 (9.3-fold). When expressed in constant 1965 dollars, the total cost per test decreased from 0.79 dollars to 0.15 dollars. Turnaround time for availability of results on patient units decreased to the extent that Stat specimens requiring a turnaround time of <1 h do not need to be separately prepared or prioritized on the system. Our experience shows that the introduction of a robotics system for perianalytical automation has brought a large improvement in productivity together with decreased operational cost. It enabled us to significantly increase our workload together with a reduction of personnel. In addition, stats are handled easily and there are benefits such as safer working conditions and improved sample identification, which are difficult to quantify at this stage.
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Mortier, Virginie; Vancoillie, Leen; Dauwe, Kenny; Staelens, Delfien; Demecheleer, Els; Schauvliege, Marlies; Dinakis, Sylvie; Van Maerken, Tom; Dessilly, Géraldine; Ruelle, Jean; Verhofstede, Chris
2017-10-24
Pre-analytical sample processing is often overlooked as a potential cause of inaccurate assay results. Here we demonstrate how plasma, extracted from standard EDTA-containing blood collection tubes, may contain traces of blood cells consequently resulting in a false low-level HIV-1 viral load when using Roche Cobas HIV-1 assays. The presence of human DNA in Roche Cobas 4800 RNA extracts and in RNA extracts from the Abbott HIV-1 RealTime assay was assessed by quantifying the human albumin gene by means of quantitative PCR. RNA was extracted from plasma samples before and after an additional centrifugation and tested for viral load and DNA contamination. The relation between total DNA content and viral load was defined. Elevated concentrations of genomic DNA were detected in 28 out of 100 Cobas 4800 extracts and were significantly more frequent in samples processed outside of the AIDS Reference Laboratory. An association between genomic DNA presence and spurious low-level viraemia results was demonstrated. Supplementary centrifugation of plasma before RNA extraction eliminated the contamination and the false viraemia. Plasma isolated from standard EDTA-containing blood collection tubes may contain traces of HIV DNA leading to false viral load results above the clinical cutoff. Supplementary centrifugation of plasma before viral load analysis may eliminate the occurrence of this spurious low-level viraemia.
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IT Infrastructure Components for Biobanking
Prokosch, H.U.; Beck, A.; Ganslandt, T.; Hummel, M.; Kiehntopf, M.; Sax, U.; Ückert, F.; Semler, S.
2010-01-01
Objective Within translational research projects in the recent years large biobanks have been established, mostly supported by homegrown, proprietary software solutions. No general requirements for biobanking IT infrastructures have been published yet. This paper presents an exemplary biobanking IT architecture, a requirements specification for a biorepository management tool and exemplary illustrations of three major types of requirements. Methods We have pursued a comprehensive literature review for biobanking IT solutions and established an interdisciplinary expert panel for creating the requirements specification. The exemplary illustrations were derived from a requirements analysis within two university hospitals. Results The requirements specification comprises a catalog with more than 130 detailed requirements grouped into 3 major categories and 20 subcategories. Special attention is given to multitenancy capabilities in order to support the project-specific definition of varying research and bio-banking contexts, the definition of workflows to track sample processing, sample transportation and sample storage and the automated integration of preanalytic handling and storage robots. Conclusion IT support for biobanking projects can be based on a federated architectural framework comprising primary data sources for clinical annotations, a pseudonymization service, a clinical data warehouse with a flexible and user-friendly query interface and a biorepository management system. Flexibility and scalability of all such components are vital since large medical facilities such as university hospitals will have to support biobanking for varying monocentric and multicentric research scenarios and multiple medical clients. PMID:23616851
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IT Infrastructure Components for Biobanking.
Prokosch, H U; Beck, A; Ganslandt, T; Hummel, M; Kiehntopf, M; Sax, U; Uckert, F; Semler, S
2010-01-01
Within translational research projects in the recent years large biobanks have been established, mostly supported by homegrown, proprietary software solutions. No general requirements for biobanking IT infrastructures have been published yet. This paper presents an exemplary biobanking IT architecture, a requirements specification for a biorepository management tool and exemplary illustrations of three major types of requirements. We have pursued a comprehensive literature review for biobanking IT solutions and established an interdisciplinary expert panel for creating the requirements specification. The exemplary illustrations were derived from a requirements analysis within two university hospitals. The requirements specification comprises a catalog with more than 130 detailed requirements grouped into 3 major categories and 20 subcategories. Special attention is given to multitenancy capabilities in order to support the project-specific definition of varying research and bio-banking contexts, the definition of workflows to track sample processing, sample transportation and sample storage and the automated integration of preanalytic handling and storage robots. IT support for biobanking projects can be based on a federated architectural framework comprising primary data sources for clinical annotations, a pseudonymization service, a clinical data warehouse with a flexible and user-friendly query interface and a biorepository management system. Flexibility and scalability of all such components are vital since large medical facilities such as university hospitals will have to support biobanking for varying monocentric and multicentric research scenarios and multiple medical clients.
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Nardin, Tiziana; Barnaba, Chiara; Abballe, Franco; Trenti, Gianmaria; Malacarne, Mario; Larcher, Roberto
2017-10-01
A fast separation based on cation-exchange liquid chromatography coupled with high-resolution mass spectrometry is proposed for simultaneous determination of chlormequat, difenzoquat, diquat, mepiquat and paraquat in several food and beverage commodities. Solid samples were extracted using a mixture of water/methanol/formic acid (69.6:30:0.4, v/v/v), while liquid samples were ten times diluted with the same solution. Separation was carried out on an experimental length-modified IonPac CS17 column (2 × 15 mm 2 ) that allowed the use of formic acid and acetonitrile as mobile phase. Detection limits for food and beverage matrices were established at 1.5 μg/L for chlormequat, difenzoquat and mepiquat, and 3 μg/L for diquat and paraquat, while for drinking water a pre-analytical sample concentration allowed detection limits of 9 and 20 ng/L, respectively. Precision, as repeatability (RSD%), ranged from 0.2 to 24%, with a median value of 6%, and trueness, as recovery, ranged from 64 to 118%, with a median value of 96%. The method developed was successfully applied to investigate the presence of herbicide residues in commercial commodities (mineral water, orange juice, beer, tea, green coffee bean, toasted coffee powder, cocoa bean, white corn flour, rice and sugar samples). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Rossum, Huub H van; Kemperman, Hans
2017-07-26
General application of a moving average (MA) as continuous analytical quality control (QC) for routine chemistry assays has failed due to lack of a simple method that allows optimization of MAs. A new method was applied to optimize the MA for routine chemistry and was evaluated in daily practice as continuous analytical QC instrument. MA procedures were optimized using an MA bias detection simulation procedure. Optimization was graphically supported by bias detection curves. Next, all optimal MA procedures that contributed to the quality assurance were run for 100 consecutive days and MA alarms generated during working hours were investigated. Optimized MA procedures were applied for 24 chemistry assays. During this evaluation, 303,871 MA values and 76 MA alarms were generated. Of all alarms, 54 (71%) were generated during office hours. Of these, 41 were further investigated and were caused by ion selective electrode (ISE) failure (1), calibration failure not detected by QC due to improper QC settings (1), possible bias (significant difference with the other analyzer) (10), non-human materials analyzed (2), extreme result(s) of a single patient (2), pre-analytical error (1), no cause identified (20), and no conclusion possible (4). MA was implemented in daily practice as a continuous QC instrument for 24 routine chemistry assays. In our setup when an MA alarm required follow-up, a manageable number of MA alarms was generated that resulted in valuable MA alarms. For the management of MA alarms, several applications/requirements in the MA management software will simplify the use of MA procedures.
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Abnormal gel flotation caused by contrast media during adrenal vein sampling.
Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Gelati, Matteo; Bassi, Antonella; Contro, Alberto; Pizzolo, Francesca; Guidi, Gian Cesare
2016-10-15
During adrenal venous sampling (AVS) procedure, radiologists administer a contrast agent via the catheter to visualize the proper catheter position. A patient with primary aldosteronism diagnostic-hypothesis was admitted for AVS. A venogram was performed to confirm the catheter's position with 2mL of Iopamidol 300 mg/mL. Samples were collected with syringe connected to a hydrophilic coated catheter by low-pressure aspiration from each of the four collection sites: inferior vena cava in the suprarenal portion, inferior vena cava in the infrarenal portion, left adrenal vein, and right adrenal vein; then immediately transferred from syringe to tubes with gel separator. All tubes were centrifuged at 1200 x g for 10 minutes. At the end of centrifugation process, primary blood tubes containing blood from inferior vena cava and left adrenal vein exhibited the standard gel separator barrier, while tubes from right adrenal vein showed abnormal flotation of gel separator. The radiologist confirmed the usage of 2.6 mL instead of 2.0 mL of Iopamidol 300 mg/mL. This iodinated contrast media, with 1.33 g/cm 3 of density, was used close to the right adrenal vein due to some difficulty to access it. The abnormal flotation of gel separator in samples taken from right adrenal vein can be explained by the usage of the iodinated contrast media. We suggest using plain-tubes (without gel separator) for AVS in order to avoid preanalytical nonconformities. Moreover, a blood volume equivalent to twice the catheter extension should be discarded to eliminate residual contrast media before collection of samples for laboratory assays.
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Haverstick, Doris M; Brill, Louis B; Scott, Mitchell G; Bruns, David E
2009-05-01
Measurements of free (ionized) calcium (iCa) are increasingly requested in patient care locations where immediate analysis is unavailable. Evacuated blood collection tubes containing lithium heparin and gel separator material are widely used in clinical laboratories, but little information is available on the effects of these tubes or of delay prior to analysis on the concentration or stability of iCa. We collected blood from volunteers into lithium-heparin tubes (PST, Vacutainer PST, BD Pre-Analytic Systems) of multiple lots and into electrolyte-balanced heparin syringes (Portex Dry Heparin, Smiths Medical). iCa was measured (Siemens 1265 blood gas analyzers) immediately and, in PST, at 0-7 h with or without transportation of the tubes from remote sites. The mean difference of free calcium results in the PST tubes and electrolyte-balanced syringes was -0.08 (95% confidence interval -0.17 to 0.012) mmol/l, and the SD of the residuals (Sy, x) of the regression was 0.03 mmol/l. There was no detectable lot-to-lot variation in results. Free calcium was stable in tubes at room temperature and at 4 degrees C for at least 7 h with or without transportation. iCa measured in the examined blood collection tubes is stable and unaffected by lot-to-lot variation of tubes, but results are slightly lower than with special blood gas syringes.
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Dried Blood Spots - Preparing and Processing for Use in Immunoassays and in Molecular Techniques
Grüner, Nico; Stambouli, Oumaima; Ross, R. Stefan
2015-01-01
The idea of collecting blood on a paper card and subsequently using the dried blood spots (DBS) for diagnostic purposes originated a century ago. Since then, DBS testing for decades has remained predominantly focused on the diagnosis of infectious diseases especially in resource-limited settings or the systematic screening of newborns for inherited metabolic disorders and only recently have a variety of new and innovative DBS applications begun to emerge. For many years, pre-analytical variables were only inappropriately considered in the field of DBS testing and even today, with the exception of newborn screening, the entire pre-analytical phase, which comprises the preparation and processing of DBS for their final analysis has not been standardized. Given this background, a comprehensive step-by-step protocol, which covers al the essential phases, is proposed, i.e., collection of blood; preparation of blood spots; drying of blood spots; storage and transportation of DBS; elution of DBS, and finally analyses of DBS eluates. The effectiveness of this protocol was first evaluated with 1,762 coupled serum/DBS pairs for detecting markers of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus infections on an automated analytical platform. In a second step, the protocol was utilized during a pilot study, which was conducted on active drug users in the German cities of Berlin and Essen. PMID:25867233
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Beyond laser microdissection technology: follow the yellow brick road for cancer research
Legres, Luc G; Janin, Anne; Masselon, Christophe; Bertheau, Philippe
2014-01-01
Normal biological tissues harbour different populations of cells with intricate spacial distribution patterns resulting in heterogeneity of their overall cellular composition. Laser microdissection involving direct viewing and expertise by a pathologist, enables access to defined cell populations or specific region on any type of tissue sample, thus selecting near-pure populations of targeted cells. It opens the way for molecular methods directed towards well-defined populations, and provides also a powerful tool in studies focused on a limited number of cells. Laser microdissection has wide applications in oncology (diagnosis and research), cellular and molecular biology, biochemistry and forensics for tissue selection, but other areas have been gradually opened up to these new methodological approaches, such as cell cultures and cytogenetics. In clinical oncology trials, molecular profiling of microdissected samples can yield global “omics” information which, together, with the morphological analysis of cells, can provide the basis for diagnosis, prognosis and patient-tailored treatments. This remarkable technology has brought new insights in the understanding of DNA, RNA, and the biological functions and regulation of proteins to identify molecular disease signatures. We review herein the different applications of laser microdissection in a variety of fields, and we particularly focus attention on the pre-analytical steps that are crucial to successfully perform molecular-level investigations. PMID:24482735
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Simundic, A M; Cornes, M; Grankvist, K; Lippi, G; Nybo, M
2014-05-15
Standardized protocols for patient preparation for laboratory testing are currently lacking. Moreover, a great heterogeneity exists in the definitions of "fasting" currently being used among healthcare workers and in the literature. Marked metabolic and hormonal changes occur after food ingestion, mainly due to the absorption of fluids, lipids, proteins, carbohydrates and other food constituents. This postprandial response varies markedly in response to numerous factors, such as eating behavior, food composition, fasting duration, time of the day, chronic and acute smoking, coffee and alcohol consumption. It is therefore crucial to minimize the total variability by controlling as many of these modifying factors as possible. Control of the abovementioned effects on postprandial response can only be achieved by standardizing the way patients are prepared for laboratory testing, i.e. by defining the fasting duration, as well as what is and what is not allowed (e.g., coffee, tea, smoking, water) during the period of fasting prior to sample collection. The aim of this article is to describe the range of effects of different approaches to fasting on laboratory tests, and to provide a framework for the harmonization of definitions for fasting requirements for laboratory tests. Copyright © 2013 Elsevier B.V. All rights reserved.
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Pinder, Nadine; Brenner, Thorsten; Swoboda, Stefanie; Weigand, Markus A; Hoppe-Tichy, Torsten
2017-09-05
Therapeutic drug monitoring (TDM) is a useful tool to optimize antibiotic therapy. Increasing interest in alternative dosing strategies of beta-lactam antibiotics, e.g. continuous or prolonged infusion, require a feasible analytical method for quantification of these antimicrobial agents. However, pre-analytical issues including sample handling and stability are to be considered to provide valuable analytical results. For the simultaneous determination of piperacillin, meropenem, ceftazidime and flucloxacillin, a high performance liquid chromatography (HPLC) method including protein precipitation was established utilizing ertapenem as internal standard. Long-term stability of stock solutions and plasma samples were monitored. Furthermore, whole blood stability of the analytes in heparinized blood tubes was investigated comparing storage under ambient conditions and 2-8°C. A calibration range of 5-200μg/ml (piperacillin, ceftazidime, flucloxacillin) and 2-200μg/ml (meropenem) was linear with r 2 >0.999, precision and inaccuracy were <9% and <11%, respectively. The successfully validated HPLC assay was applied to clinical samples and stability investigations. At -80°C, plasma samples were stable for 9 months (piperacillin, meropenem) or 13 months (ceftazidime, flucloxacillin). Concentrations of the four beta-lactam antibiotics in whole blood tubes were found to remain within specifications for 8h when stored at 2-8°C but not at room temperature. The presented method is a rapid and simple option for routine TDM of piperacillin, meropenem, ceftazidime and flucloxacillin. Whereas long-term storage of beta-lactam samples at -80°C is possible for at least 9 months, whole blood tubes are recommended to be kept refrigerated until analysis. Copyright © 2017 Elsevier B.V. All rights reserved.
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Analyte stability during the total testing process: studies of vitamins A, D and E by LC-MS/MS.
Albahrani, Ali A; Rotarou, Victor; Roche, Peter J; Greaves, Ronda F
2016-10-01
There are limited evidence based studies demonstrating the stability of fat-soluble vitamins (FSV) measured in blood. This study aimed to examine the effects of light, temperature and time on vitamins A, D and E throughout the total testing process. Four experiments were conducted. Three investigated the sample matrix, of whole blood, serum and the extracted sample, against the variables of temperature and light; and the fourth experiment investigated the sample during the extraction process against the variable of light. All samples were analysed via our simultaneous FSV method using liquid chromatography-tandem mass spectrometry technology. The allowable clinical percentage change was calculated based on biological variation and desirable method imprecision for each analyte. The total change limit was ±7.3% for 25-OH-vitamin D3, ±11.8% for retinol and ±10.8% for α-tocopherol. Vitamins D and E were stable in the investigated conditions (concentration changes <4%) in the pre-analytical and analytical stages. Vitamin A showed photosensitivity in times >48 h with concentration changes of -6.8% (blood) and -6.5% (serum), both are within the allowable clinical percentage change. By contrast, the extracted retinol sample demonstrated a concentration change of -18.4% after 48 h of light exposure. However, vitamin A in the serum and extracted solution was stable for one month when stored at -20°C. Blood samples for vitamins D and E analyses can be processed in normal laboratory conditions of lighting and temperature. The required conditions for vitamin A analysis are similar when performed within 48 h. For longer-term storage, serum and vitamin A extracts should be stored at -20°C.
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Frickmann, H; Bachert, S; Warnke, P; Podbielski, A
2018-03-01
Preanalytic aspects can make results of hygiene studies difficult to compare. Efficacy of surface disinfection was assessed with an evaluated swabbing procedure. A validated microbial screening of surfaces was performed in the patients' environment and from hands of healthcare workers on two intensive care units (ICUs) prior to and after a standardized disinfection procedure. From a pure culture, the recovery rate of the swabs for Staphylococcus aureus was 35%-64% and dropped to 0%-22% from a mixed culture with 10-times more Staphylococcus epidermidis than S. aureus. Microbial surface loads 30 min before and after the cleaning procedures were indistinguishable. The quality-ensured screening procedure proved that adequate hygiene procedures are associated with a low overall colonization of surfaces and skin of healthcare workers. Unchanged microbial loads before and after surface disinfection demonstrated the low additional impact of this procedure in the endemic situation when the pathogen load prior to surface disinfection is already low. Based on a validated screening system ensuring the interpretability and reliability of the results, the study confirms the efficiency of combined hand and surface hygiene procedures to guarantee low rates of bacterial colonization. © 2017 The Society for Applied Microbiology.
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Hähnel, Viola; Dormann, Frauke; Nitsopoulos, Athanasios; Friedle, Albrecht; Ahrens, Norbert
2017-02-15
Extracorporeal photopheresis (ECP) is an efficient method to treat various autoimmune diseases, cutaneous T-cell lymphoma, and graft-versus-host disease. It is based on the ex vivo inactivation of lymphocytes by 8-methoxypsoralen (8-MOP)/UV light treatment. Despite the adhesive, lipophilic nature of 8-MOP, no quality control is established for the ECP procedure. We developed a sensitive high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) assay to monitor residual 8-MOP concentration after UVA irradiation in the whole blood supernatant after acetonitrile precipitation. The preanalytical stability of 8-MOP exceeded 7 days, allowing batch mode analysis. Linearity was determined with R 2 above 0.99. The 8-MOP concentrations decreased exponentially after UV exposure, with decay constants of 0.0259 in plasma and 0.0528 in saline. The recovery of 8-MOP in photopheresates was about 68%, indicating binding to DNA as well as to plastic structures. UVA induced no 8-MOP fragmentation, but caused self-adducts under extreme conditions (10-fold UV dosage). Detection of 8-MOP proved to be feasible and demonstrated that the doses were in the pharmaceutically active range.
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Direct-to-consumer testing: more risks than opportunities.
Lippi, G; Favaloro, E J; Plebani, M
2011-12-01
As a result of incessant genetic discoveries and remarkable technological advancements, the availability and the consequent consumer's request for genetic testing are growing exponentially, leading to the development of a 'parallel' market, i.e. the direct-to-consumer (DTC) testing, also known as 'direct access testing' (DAT). Analogous to the traditional laboratory diagnostics, drawbacks of DTC testing might arise from any step characterising the total testing process, and include poor control of both appropriateness and preanalytical requirements, potential operation outside national or international regulation for in vitro diagnostic testing, little evidence of quality as well as the risk of transfer of genetic materials from the companies to other entities. Another important issue is the test panels offered to consumers, which are often based on preliminary, speculative or unsupported scientific information. Finally, the potential of this type of testing to generate anxiety or false reassurance should also be carefully considered. Although DTC testing carries some theoretical advantages (e.g. greater consumer autonomy and empowerment), solid clinical studies and costs vs. benefit analyses are needed to definitely establish whether DTC testing might be effective for decreasing the burden of diseases, delay their onset or modify their progression and therefore the clinical outcome. © 2011 Blackwell Publishing Ltd.
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Kang, Ju-Hee; Vanderstichele, Hugo; Trojanowski, John Q; Shaw, Leslie M
2012-04-01
The xMAP-Luminex multiplex platform for measurement of Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers using Innogenetics AlzBio3 immunoassay reagents that are for research use only has been shown to be an effective tool for early detection of an AD-like biomarker signature based on concentrations of CSF Aβ(1-42), t-tau and p-tau(181). Among the several advantages of the xMAP-Luminex platform for AD CSF biomarkers are: a wide dynamic range of ready-to-use calibrators, time savings for the simultaneous analyses of three biomarkers in one analytical run, reduction of human error, potential of reduced cost of reagents, and a modest reduction of sample volume as compared to conventional enzyme-linked immunosorbant assay (ELISA) methodology. Recent clinical studies support the use of CSF Aβ(1-42), t-tau and p-tau(181) measurement using the xMAP-Luminex platform for the early detection of AD pathology in cognitively normal individuals, and for prediction of progression to AD dementia in subjects with mild cognitive impairment (MCI). Studies that have shown the prediction of risk for progression to AD dementia by MCI patients provide the basis for the use of CSF Aβ(1-42), t-tau and p-tau(181) testing to assign risk for progression in patients enrolled in therapeutic trials. Furthermore emerging study data suggest that these pathologic changes occur in cognitively normal subjects 20 or more years before the onset of clinically detectable memory changes thus providing an objective measurement for use in the assessment of treatment effects in primary treatment trials. However, numerous previous ELISA and Luminex-based multiplex studies reported a wide range of absolute values of CSF Aβ(1-42), t-tau and p-tau(181) indicative of substantial inter-laboratory variability as well as varying degrees of intra-laboratory imprecision. In order to address these issues a recent inter-laboratory investigation that included a common set of CSF pool aliquots from controls as well as AD patients over a range of normal and pathological Aβ(1-42), t-tau and p-tau(181) values as well as agreed-on standard operating procedures (SOPs) assessed the reproducibility of the multiplex methodology and Innogenetics AlzBio3 immunoassay reagents. This study showed within-center precision values of 5% to a little more than 10% and good inter-laboratory %CV values (10-20%). There are several likely factors influencing the variability of CSF Aβ(1-42), t-tau and p-tau(181) measurements. In this review, we describe the pre-analytical, analytical and post-analytical sources of variability including sources inherent to kits, and describe procedures to decrease the variability. A CSF AD biomarker Quality Control program has been established and funded by the Alzheimer Association, and global efforts are underway to further define optimal pre-analytical SOPs and best practices for the methodologies available or in development including plans for production of a standard reference material that could provide for a common standard against which manufacturers of immunoassay kits would assign calibration standard values. Copyright © 2012 Elsevier Inc. All rights reserved.
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Isokawa, Muneki; Kanamori, Takahiro; Funatsu, Takashi; Tsunoda, Makoto
2014-08-01
Low-molecular-weight biothiols such as homocysteine, cysteine, and glutathione are metabolites of the sulfur cycle and play important roles in biological processes such as the antioxidant defense network, methionine cycle, and protein synthesis. Thiol concentrations in human plasma and blood are related to diseases such as cardiovascular disease, neurodegenerative disease, and cancer. The concentrations of homocysteine, cysteine, and glutathione in plasma samples from healthy human subjects are approximately in the range of 5-15, 200-300, and 1-5 μM, respectively. Glutathione concentration in the whole blood is in the millimolar range. Measurement of biothiol levels in plasma and blood is thought to be important for understanding the physiological roles and biomarkers for certain diseases. This review summarizes the relationship of biothiols with certain disease as well as pre-analytical treatment and analytical methods for determination of biothiols in human plasma and blood by using high-performance liquid chromatography and capillary electrophoresis coupled with ultraviolet, fluorescence, or chemiluminescence detection; or mass spectrometry. Copyright © 2014 Elsevier B.V. All rights reserved.
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Ekşioğlu, Merve Kaymak; Madenci, Özlem Çakır; Yücel, Nihal; Elçi, Abdullah; Turhan, Bülent; Orhan, Gani; Orçun, Asuman
2016-01-01
The aim of this study was to evaluate the stability of urine collected in preservative tubes for chemistry strip analyses and particle counting to determine whether the transport of urine samples with all of their constituents is possible. 275 pathologic urine specimens were included. Each urine sample was evaluated after 4, 8, 12, 24, and 48 hours of storage in BD Vacutainer(®) Plus Urinalysis Preservative (BD UAP) tubes and compared with refrigeration at 4 °C. All analyses were peformed on H-800 and FUS-200 automatic modular urine analyzers (Dirui Industry, Changchun, China). The kappa coefficients (κ), false positive (FP) and false negative (FN) rates were evaluated. κ > 0.8 was accepted as good agreement. Haemoglobin (Hb), leucocyte esterase (LE), and protein (Pro) analyses should be performed within 4 hours, whereas glucose (Glc) was stable until the end of 48 hours in both storage conditions. Nitrite (Nit) was well preserved in BD UAP tubes for 24 hours but was stable only up to 8 hours at 4 °C. Bilirubin (Bil) had very high FN rates even at 4 hours in both conditions. The particle counting showed high FN rates for white blood cells (WBC) and red blood cells (RBC), whereas squamous epithelial cells (EC) were stable up to 8 hours in both conditions. Preanalytical requirements for both urine chemical strip analyses and particle counting in a unique sample were not met in either condition. Thus, the transfer of urine samples for centralization of urinalysis is not yet feasible.
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Rembach, Alan; Evered, Lisbeth A; Li, Qiao-Xin; Nash, Tabitha; Vidaurre, Lesley; Fowler, Christopher J; Pertile, Kelly K; Rumble, Rebecca L; Trounson, Brett O; Maher, Sarah; Mooney, Francis; Farrow, Maree; Taddei, Kevin; Rainey-Smith, Stephanie; Laws, Simon M; Macaulay, S Lance; Wilson, William; Darby, David G; Martins, Ralph N; Ames, David; Collins, Steven; Silbert, Brendan; Masters, Colin L; Doecke, James D
2015-11-19
Cerebrospinal fluid (CSF) biomarkers, although of established utility in the diagnostic evaluation of Alzheimer's disease (AD), are known to be sensitive to variation based on pre-analytical sample processing. We assessed whether gravity droplet collection versus syringe aspiration was another factor influencing CSF biomarker analyte concentrations and reproducibility. Standardized lumbar puncture using small calibre atraumatic spinal needles and CSF collection using gravity fed collection followed by syringe aspirated extraction was performed in a sample of elderly individuals participating in a large long-term observational research trial. Analyte assay concentrations were compared. For the 44 total paired samples of gravity collection and aspiration, reproducibility was high for biomarker CSF analyte assay concentrations (concordance correlation [95%CI]: beta-amyloid1-42 (Aβ42) 0.83 [0.71 - 0.90]), t-tau 0.99 [0.98 - 0.99], and phosphorylated tau (p-tau) 0.82 [95 % CI 0.71 - 0.89]) and Bonferroni corrected paired sample t-tests showed no significant differences (group means (SD): Aβ42 366.5 (86.8) vs 354.3 (82.6), p = 0.10; t-tau 83.9 (46.6) vs 84.7 (47.4) p = 0.49; p-tau 43.5 (22.8) vs 40.0 (17.7), p = 0.05). The mean duration of collection was 10.9 minutes for gravity collection and <1 minute for aspiration. Our results demonstrate that aspiration of CSF is comparable to gravity droplet collection for AD biomarker analyses but could considerably accelerate throughput and improve the procedural tolerability for assessment of CSF biomarkers.
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Biobanking of CSF: international standardization to optimize biomarker development.
Teunissen, Charlotte E; Tumani, Hayrettin; Engelborghs, Sebastiaan; Mollenhauer, Brit
2014-03-01
Cerebrospinal fluid (CSF) reflects pathophysiological aspects of neurological diseases, where neuroprotective strategies and biomarkers are urgently needed. Therefore, biobanking is very relevant for biomarker discovery and evaluation of neurological diseases. Important and unique features of CSF biobanking are intensive collaboration in international networks and the tight application of standardized protocols. The current adoption of standardized protocols for CSF and blood collection as presented in this review enables biomarker studies in large cohorts of patients and controls. Another topic of this review is the selection of control groups, which influences the outcome of biomarker investigations. Control groups in CSF biobanks mainly consist of different disease controls. This is in part due to the fact that lumbar punctures are mostly performed for clinical indications and rarely for research purposes only, as it is a relatively invasive procedure. Moreover, there is a lack of homogenous criteria and definition of control groups. We therefore propose uniform consensus definitions for such control groups in biomarker research, i.e. Healthy controls (HC), Spinal anesthesia subjects (SAS), Symptomatic controls (SC), Inflammatory Neurological Disease Controls (CINDC), Peripheral Inflammatory Neurological Disease Controls (PINDC) and Non-inflammatory Neurological Disease Controls (NINDC). Another important aspect of CSF biobanking is quality control. Systematic studies to address effects of pre-analytical and storage variation on a broad range of CSF proteins are needed. In conclusion, biomarker research in neurodegenerative diseases has entered a new era due to the collaborative and multicenter efforts of many groups. The streamlining of biobanking procedures, including quality control, and the selection of optimal control groups for investigating biomarkers are important improvements to perform high quality biomarker studies. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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Improving Histopathology Laboratory Productivity: Process Consultancy and A3 Problem Solving.
Yörükoğlu, Kutsal; Özer, Erdener; Alptekin, Birsen; Öcal, Cem
2017-01-01
The ISO 17020 quality program has been run in our pathology laboratory for four years to establish an action plan for correction and prevention of identified errors. In this study, we aimed to evaluate the errors that we could not identify through ISO 17020 and/or solve by means of process consulting. Process consulting is carefully intervening in a group or team to help it to accomplish its goals. The A3 problem solving process was run under the leadership of a 'workflow, IT and consultancy manager'. An action team was established consisting of technical staff. A root cause analysis was applied for target conditions, and the 6-S method was implemented for solution proposals. Applicable proposals were activated and the results were rated by six-sigma analysis. Non-applicable proposals were reported to the laboratory administrator. A mislabelling error was the most complained issue triggering all pre-analytical errors. There were 21 non-value added steps grouped in 8 main targets on the fish bone graphic (transporting, recording, moving, individual, waiting, over-processing, over-transaction and errors). Unnecessary redundant requests, missing slides, archiving issues, redundant activities, and mislabelling errors were proposed to be solved by improving visibility and fixing spaghetti problems. Spatial re-organization, organizational marking, re-defining some operations, and labeling activities raised the six sigma score from 24% to 68% for all phases. Operational transactions such as implementation of a pathology laboratory system was suggested for long-term improvement. Laboratory management is a complex process. Quality control is an effective method to improve productivity. Systematic checking in a quality program may not always find and/or solve the problems. External observation may reveal crucial indicators about the system failures providing very simple solutions.
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Rossi, Gabriele; Giori, Luca; Campagnola, Simona; Zatelli, Andrea; Zini, Eric; Paltrinieri, Saverio
2012-06-01
To determine whether preanalytic and analytic factors affect evaluation of the urinary protein-to-creatinine (UPC) ratio in dogs. 50 canine urine samples. The UPC ratio was measured to assess the intra-assay imprecision (20 measurements within a single session), the influence of predilution (1:10, 1:20, and 1:100) for urine creatinine concentration measurement, and the effect of storage at room temperature (approx 20°C), 4°C, and -20°C. The coefficient of variation at room temperature determined with the 1:20 predilution was < 10.0%, with the highest coefficients of variation found in samples with a low protein concentration or low urine specific gravity. This variability could result in misclassification of samples with UPC ratios close to the thresholds defined by the International Renal Interest Society to classify dogs as nonproteinuric (0.2), borderline proteinuric (0.21 to 0.50), or proteinuric (> 0.51). A proportional bias was found in samples prediluted 1:10, compared with samples prediluted 1:20 or 1:100. At room temperature, the UPC ratio did not significantly increase after 2 and 4 hours. After 12 hours at room temperature and at 4°C, the UPC ratio significantly increased. The UPC ratio did not significantly change during 3 months of storage at -20°C. The intra-assay precision of the UPC ratio was sufficiently low to avoid misclassification of samples, except for values close to 0.2 or 0.5. The optimal predilution ratio for urine creatinine concentration measurement was 1:20. A 1:100 predilution is recommended in samples with a urine specific gravity > 1.030. The UPC ratio must be measured as soon as samples are collected. Alternatively, samples should be immediately frozen to increase their stability and minimize the risk of misclassification of proteinuria.
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Abnormal gel flotation caused by contrast media during adrenal vein sampling
Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Gelati, Matteo; Bassi, Antonella; Contro, Alberto; Pizzolo, Francesca; Guidi, Gian Cesare
2016-01-01
Introduction During adrenal venous sampling (AVS) procedure, radiologists administer a contrast agent via the catheter to visualize the proper catheter position. Materials and methods A patient with primary aldosteronism diagnostic-hypothesis was admitted for AVS. A venogram was performed to confirm the catheter’s position with 2mL of Iopamidol 300 mg/mL. Samples were collected with syringe connected to a hydrophilic coated catheter by low-pressure aspiration from each of the four collection sites: inferior vena cava in the suprarenal portion, inferior vena cava in the infrarenal portion, left adrenal vein, and right adrenal vein; then immediately transferred from syringe to tubes with gel separator. All tubes were centrifuged at 1200 x g for 10 minutes. Results At the end of centrifugation process, primary blood tubes containing blood from inferior vena cava and left adrenal vein exhibited the standard gel separator barrier, while tubes from right adrenal vein showed abnormal flotation of gel separator. The radiologist confirmed the usage of 2.6 mL instead of 2.0 mL of Iopamidol 300 mg/mL. This iodinated contrast media, with 1.33 g/cm3 of density, was used close to the right adrenal vein due to some difficulty to access it. Conclusion The abnormal flotation of gel separator in samples taken from right adrenal vein can be explained by the usage of the iodinated contrast media. We suggest using plain-tubes (without gel separator) for AVS in order to avoid preanalytical nonconformities. Moreover, a blood volume equivalent to twice the catheter extension should be discarded to eliminate residual contrast media before collection of samples for laboratory assays. PMID:27812311
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Mellen, Samantha; de Ferrars, Maria; Chapman, Claire; Bevan, Sarah; Turvill, James; Turnock, Daniel
2018-01-01
Background Faecal immunochemical testing is increasingly being used to triage symptomatic patients for suspected colorectal cancer. However, there are limited data on the effect of preanalytical factors on faecal haemoglobin when measured by faecal immunochemical testing. The aim of this work was to evaluate the stability of faecal haemoglobin in faeces and to compare two methods of faecal haemoglobin sampling for faecal immunochemical testing. Methods Six patients provided faeces for faecal haemoglobin measurement which were transferred into specialized collection devices at baseline and at 1, 2, 3 and 7 days after storage at either room temperature or 4°C. A total of 137 patients returned both faeces transferred into the specialized collection device and faeces in a standard collection pot. A quantitative immunoturbidometric method was used to measure faecal haemoglobin and results were compared categorically. Discrepant results were assessed against diagnosis. Results Faecal haemoglobin concentration declined rapidly within a day of storage at room temperature but results remained ≥10 μg Hb/g faeces in 5/6 patients after two days. A faecal haemoglobin result ≥10 μg Hb/g faeces was obtained in 4/6 patients after storage for seven days at 4°C. Results obtained when patients used specialized collection devices were significantly different from results obtained when faeces was transferred into the specialized collection device in the laboratory. Conclusion There is considerable heterogeneity in the sample stability of faecal haemoglobin; therefore, samples should be transferred rapidly into specialized collection devices to prevent false-negative results. Use of collection devices by patients can lead to false-positive results compared with their use in a laboratory.
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Experience of quality management system in a clinical laboratory in Nigeria
Sylvester-Ikondu, Ugochukwu; Onwuamah, Chika K.; Salu, Olumuyiwa B.; Ige, Fehintola A.; Meshack, Emily; Aniedobe, Maureen; Amoo, Olufemi S.; Okwuraiwe, Azuka P.; Okhiku, Florence; Okoli, Chika L.; Fasela, Emmanuel O.; Odewale, Ebenezer. O.; Aleshinloye, Roseline O.; Olatunji, Micheal; Idigbe, Emmanuel O.
2012-01-01
Issues Quality-management systems (QMS) are uncommon in clinical laboratories in Nigeria, and until recently, none of the nation’s 5 349 clinical laboratories have been able to attain the certifications necessary to begin the process of attaining international accreditation. Nigeria’s Human Virology Laboratory (HVL), however, began implementation of a QMS in 2006, and in 2008 it was determined that the laboratory conformed to the requirements of ISO 9001:2000 (now 2008), making it the first diagnostic laboratory to be certified in Nigeria. The HVL has now applied for the World Health Organization (WHO) accreditation preparedness scheme. The experience of the QMS implementation process and the lessons learned therein are shared here. Description In 2005, two personnel from the HVL spent time studying quality systems in a certified clinical laboratory in Dakar, Senegal. Following this peer-to-peer technical assistance, several training sessions were undertaken by HVL staff, a baseline assessment was conducted, and processes were established. The HVL has monitored its quality indicators and conducted internal and external audits; these analyses (from 2007 to 2009) are presented herein. Lessons learned Although there was improvement in the pre-analytical and analytical indicators analysed and although data-entry errors decreased in the post-analytical process, the delay in returning laboratory test results increased significantly. There were several factors identified as causes for this delay and all of these have now been addressed except for an identified need for automation of some high-volume assays (currently being negotiated). Internal and external audits showed a trend of increasing non-conformities which could be the result of personnel simply becoming lax over time. Application for laboratory accreditation, however, could provide the renewed vigour needed to correct these non-conformities. Recommendation This experience shows that sustainability of the QMS at present is a cause for concern. However, the tiered system of accreditation being developed by WHO–Afro may act as a driving force to preserve the spirit of continual improvement. PMID:29062734
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Van Keer, Severien; Pattyn, Jade; Tjalma, Wiebren A A; Van Ostade, Xaveer; Ieven, Margareta; Van Damme, Pierre; Vorsters, Alex
2017-09-01
Great interest has been directed towards the use of first-void urine as a liquid biopsy for high-risk human papillomavirus DNA testing. Despite the high correlations established between urinary and cervical infections, human papillomavirus testing is unable to distinguish between productive and transforming high-risk infections that have the tendency to progress to cervical cancer. Thus far, investigations have been primarily confined to the identification of biomarkers for triage of high-risk human papillomavirus-positive women in cervicovaginal specimens and tissue biopsies. This paper reviews urinary biomarkers for cervical cancer and triage of high-risk human papillomavirus infections and elaborates on the opportunities and challenges that have emerged regarding the use of first-void urine as a liquid biopsy for the analysis of both morphological- (conventional cytology and novel immunohistochemical techniques) and molecular-based (HPV16/18 genotyping, host/viral gene methylation, RNA, and proteins) biomarkers. A literature search was performed in PubMed and Web of Science for studies investigating the use of urine as a biomarker source for cervical cancer screening. Five studies were identified reporting on biomarkers that are still in preclinical exploratory or clinical assay development phases and on assessments of non-invasive (urine) samples. Although large-scale validation studies are still needed, we conclude that methylation of both host and viral genes in urine has been proven feasible for use as a molecular cervical cancer triage and screening biomarker in phase two studies. This is especially promising and underscores our hypothesis that human papillomavirus DNA and candidate human and viral biomarkers are washed away with the initial, first-void urine, together with exfoliated cells, debris and impurities that line the urethra opening. Similar to the limitations of self-collected cervicovaginal samples, first-void urine will likely not fulfil the high-quality cellularity standards required for morphological biomarkers. Molecular biomarkers will likely overcome this issue to yield high-throughput, objective, and reproducible results. When using proper sampling, transport, storage, preanalytical biomarker concentration techniques, and clinically validated assays, first-void urine is expected to be a valuable source of molecular biomarkers for cervical cancer screening. Furthermore, as first-void urine can be easily and non-invasively collected, it is a highly preferred technique among women and offers the ability to test both primary high-risk human papillomavirus and biomarkers in the same sample. In addition, the use of first-void urine confers opportunities to reduce loss-to follow-up and non-adherence to screening subjects. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.
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Screening the low molecular weight fraction of human serum using ATR-IR spectroscopy.
Bonnier, Franck; Brachet, Guillaume; Duong, Romain; Sojinrin, Tobiloba; Respaud, Renaud; Aubrey, Nicolas; Baker, Matthew J; Byrne, Hugh J; Chourpa, Igor
2016-10-01
Vibrational spectroscopic techniques can detect small variations in molecular content, linked with disease, showing promise for screening and early diagnosis. Biological fluids, particularly blood serum, are potentially valuable for diagnosis purposes. The so-called Low Molecular Weight Fraction (LMWF) contains the associated peptidome and metabolome and has been identified as potentially the most relevant molecular population for disease-associated biomarker research. Although vibrational spectroscopy can deliver a specific chemical fingerprint of the samples, the High Molecular Weight Fraction (HMWF), composed of the most abundant serum proteins, strongly dominates the response and ultimately makes the detection of minor spectral variations a challenging task. Spectroscopic detection of potential serum biomarkers present at relatively low concentrations can be improved using pre-analytical depletion of the HMWF. In the present study, human serum fractionation by centrifugal filtration was used prior to analysis by Attenuated Total Reflection infrared spectroscopy. Using a model sample based on glycine spiked serum, it is demonstrated that the screening of the LMWF can be applied to quantify blinded concentrations up to 50 times lower. Moreover, the approach is easily transferable to different bodily fluids which would support the development of more efficient and suitable clinical protocols exploring vibrational spectroscopy based ex-vivo diagnostic tools. Revealing serum LMWF for spectral serological diagnostic applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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[Point of Care 2.0: Coagulation Monitoring Using Rotem® Sigma and Teg® 6S].
Weber, Christian Friedrich; Zacharowski, Kai
2018-06-01
New-generation methods for point of care based coagulation monitoring enable fully automated viscoelastic analyses for the assessment of particular parts of hemostasis. Contrary to the measuring techniques of former models, the viscoelastic ROTEM ® sigma and TEG ® 6s analyses are performed in single-use test cartridges without time- and personnel-intensive pre-analytical procedures. This review highlights methodical strengths and limitations of the devices and meets concerns associated with their integration in routine clinical practice. Georg Thieme Verlag KG Stuttgart · New York.
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Pathologists and liquid biopsies: to be or not to be?
Hofman, Paul; Popper, Helmut H
2016-12-01
Recently, the advent of therapies targeting genomic alterations has improved the care of patients with certain types of cancer. While molecular targets were initially detected in nucleic acid samples extracted from tumor tissue, detection of nucleic acids in circulating blood has allowed the development of what has become known as liquid biopsies, which provide a complementary and alternative sample source allowing identification of genomic alterations that might be addressed by targeted therapy. Consequently, liquid biopsies might rapidly revolutionize oncology practice in allowing administration of more effective treatments. Liquid biopsies also provide an approach towards short-term monitoring of metastatic cancer patients to evaluate efficacy of treatment and/or early detection of secondary mutations responsible for resistance to treatment. In this context, pathologists, who have already been required in recent years to take interest in the domain of molecular pathology of cancer, now face new challenges. The attitude of pathologists to and level of involvement in the practice of liquid biopsies, including mastering the methods employed in molecular analysis of blood samples, need close attention. Regardless of the level of involvement of pathologists in this new field, it is mandatory that oncologists, biologists, geneticists, and pathologists work together to coordinate the pre-analytical, analytical, and post-analytical phases of molecular assessment of tissue and liquid samples of individual cancer patients. The challenges include (1) implementation of effective and efficient procedures for reception and analysis of liquid and tissue samples for histopathological and molecular evaluation and (2) assuring short turn-around times to facilitate rapid optimization of individual patient treatment. In this paper, we will review the following: (1) recent data concerning the concept of liquid biopsies in oncology and its development for patient care, (2) advantages and limitations of molecular analyses performed on blood samples compared to those performed on tissue samples, and (3) short-term challenges facing pathologists in dealing with liquid biopsies of cancer patients and new strategies to early detect metastatic tumor cell clones.
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Zhou, Fangbin; Zhou, Yaying; Yang, Ming; Wen, Jinli; Dong, Jun; Tan, Wenyong
2018-01-01
Circulating endothelial cells (CECs) and their subpopulations could be potential novel biomarkers for various malignancies. However, reliable enumerable methods are warranted to further improve their clinical utility. This study aimed to optimize a flow cytometric method (FCM) assay for CECs and subpopulations in peripheral blood for patients with solid cancers. An FCM assay was used to detect and identify CECs. A panel of 60 blood samples, including 44 metastatic cancer patients and 16 healthy controls, were used in this study. Some key issues of CEC enumeration, including sample material and anticoagulant selection, optimal titration of antibodies, lysis/wash procedures of blood sample preparation, conditions of sample storage, sufficient cell events to enhance the signal, fluorescence-minus-one controls instead of isotype controls to reduce background noise, optimal selection of cell surface markers, and evaluating the reproducibility of our method, were integrated and investigated. Wilcoxon and Mann-Whitney U tests were used to determine statistically significant differences. In this validation study, we refined a five-color FCM method to detect CECs and their subpopulations in peripheral blood of patients with solid tumors. Several key technical issues regarding preanalytical elements, FCM data acquisition, and analysis were addressed. Furthermore, we clinically validated the utility of our method. The baseline levels of mature CECs, endothelial progenitor cells, and activated CECs were higher in cancer patients than healthy subjects ( P <0.01). However, there was no significant difference in resting CEC levels between healthy subjects and cancer patients ( P =0.193). We integrated and comprehensively addressed significant technical issues found in previously published assays and validated the reproducibility and sensitivity of our proposed method. Future work is required to explore the potential of our optimized method in clinical oncologic applications.
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Geffré, Anne; Concordet, Didier; Braun, Jean-Pierre; Trumel, Catherine
2011-03-01
International recommendations for determination of reference intervals have been recently updated, especially for small reference sample groups, and use of the robust method and Box-Cox transformation is now recommended. Unfortunately, these methods are not included in most software programs used for data analysis by clinical laboratories. We have created a set of macroinstructions, named Reference Value Advisor, for use in Microsoft Excel to calculate reference limits applying different methods. For any series of data, Reference Value Advisor calculates reference limits (with 90% confidence intervals [CI]) using a nonparametric method when n≥40 and by parametric and robust methods from native and Box-Cox transformed values; tests normality of distributions using the Anderson-Darling test and outliers using Tukey and Dixon-Reed tests; displays the distribution of values in dot plots and histograms and constructs Q-Q plots for visual inspection of normality; and provides minimal guidelines in the form of comments based on international recommendations. The critical steps in determination of reference intervals are correct selection of as many reference individuals as possible and analysis of specimens in controlled preanalytical and analytical conditions. Computing tools cannot compensate for flaws in selection and size of the reference sample group and handling and analysis of samples. However, if those steps are performed properly, Reference Value Advisor, available as freeware at http://www.biostat.envt.fr/spip/spip.php?article63, permits rapid assessment and comparison of results calculated using different methods, including currently unavailable methods. This allows for selection of the most appropriate method, especially as the program provides the CI of limits. It should be useful in veterinary clinical pathology when only small reference sample groups are available. ©2011 American Society for Veterinary Clinical Pathology.
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Ekşioğlu, Merve Kaymak; Madenci, Özlem Çakır; Yücel, Nihal; Elçi, Abdullah; Turhan, Bülent; Orhan, Gani; Orçun, Asuman
2016-01-01
Introduction The aim of this study was to evaluate the stability of urine collected in preservative tubes for chemistry strip analyses and particle counting to determine whether the transport of urine samples with all of their constituents is possible. Materials and methods 275 pathologic urine specimens were included. Each urine sample was evaluated after 4, 8, 12, 24, and 48 hours of storage in BD Vacutainer® Plus Urinalysis Preservative (BD UAP) tubes and compared with refrigeration at 4 °C. All analyses were peformed on H-800 and FUS-200 automatic modular urine analyzers (Dirui Industry, Changchun, China). The kappa coefficients (κ), false positive (FP) and false negative (FN) rates were evaluated. κ > 0.8 was accepted as good agreement. Results Haemoglobin (Hb), leucocyte esterase (LE), and protein (Pro) analyses should be performed within 4 hours, whereas glucose (Glc) was stable until the end of 48 hours in both storage conditions. Nitrite (Nit) was well preserved in BD UAP tubes for 24 hours but was stable only up to 8 hours at 4 °C. Bilirubin (Bil) had very high FN rates even at 4 hours in both conditions. The particle counting showed high FN rates for white blood cells (WBC) and red blood cells (RBC), whereas squamous epithelial cells (EC) were stable up to 8 hours in both conditions. Conclusions Preanalytical requirements for both urine chemical strip analyses and particle counting in a unique sample were not met in either condition. Thus, the transfer of urine samples for centralization of urinalysis is not yet feasible. PMID:27346967
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Jacobsen, Katja Kemp; Brandt, Ida; Christensen, Anne Vindahl; Rimsø, Bjørk Anine; Krøier, Camilla Julie; Sørensen, Michelle; Smith, Julie; Jensen, Kathrine Overgaard Foss; Larsen, Jeppe Madura
2018-06-01
Deviation in blood collection procedures is a central source of preanalytical variation affecting overall analytical and diagnostic precision. The order of draw of venous sampling is suspected to affect analytical results, in particular for coagulation analysis. Here we compare the procedures in venous blood sampling among clinical biochemistry departments to assess the uniformity of order of blood draw and adherence to international guidelines in the Danish health care system. We collected venous order of draw procedures from 49 clinical biochemistry departments at 22 public hospitals in Denmark. Procedures were compared to the international guidelines fromthe Clinical Laboratory Standards Institute (CLSI) and World Health Organization (WHO), and assessed in relation to department ISO 15189:2012 accreditation. We observed seven different order of draw procedures related to citrate, serum, heparin, and EDTA tubes, and the use of discard tubes in relation to coagulation assays. 31 departments (63.3%) were found to adhere to CLSI and WHO guidelines. A majority of departments instructs the use of discard tubes before collection for coagulation assays in citrate tubes (44 departments; 89.8%). The citrate tube was the first sample tube to be drawn for most departments (35 departments; 75.5%); and the preferred order of non-citrate tubes was serum-heparin-EDTA (36 departments; 73.5%). Adherence to the CLSI and WHO guidelines was not associated with department ISO 15189:2012 accreditation (p = .57). Venous order of draw procedures is diverse at Danish clinical biochemistry departments and show moderate adherence to international guidelines. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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Willems, Philippe; Weekx, Steven; Meskal, Anissa; Schouwers, Sofie
2017-04-01
The measurement of chloride and sodium concentrations in sweat is an important test for the diagnosis of cystic fibrosis (CF). The aim of this study was to assess the analytical variation (CV A ) and within-subject (CV I ) and between-subject (CV G ) biological variation of chloride and sodium concentrations in sweat, collected by pilocarpine iontophoresis and to determine their effect on the clinical interpretation of sweat test results. Twelve Caucasian adults (six male and six female) without symptoms suggestive for CF and with a mean age of 41 years (range 28-59) were included in the study. At least eight samples of sweat were collected from each individual by pilocarpine iontophoresis. Chloride and sodium concentrations were measured in duplicate for each sample using ion selective electrodes. After the removal of outliers, the CV A , CV I , and CV G of chloride and sodium were determined, and their impact on measurement uncertainty and reference change value were calculated. The CV A , CV I , and CV G of chloride in sweat samples were 6.5, 17.7, and 47.2%, respectively. The CV A , CV I , and CV G of sodium sweat samples were 6.0, 17.5, and 42.6%, respectively. Our study indicates that sweat chloride and sodium concentration results must be interpreted with great care. Different components of variation, particularly the biological variations, have a considerable impact on the interpretation of these results. If no pre-analytical, analytical, or post-analytical errors are suspected, repeated sweat testing to confirm first-measurement results might not be desirable.
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Hustad, Steinar; Eussen, Simone; Midttun, Øivind; Ulvik, Arve; van de Kant, Puck M; Mørkrid, Lars; Gislefoss, Randi; Ueland, Per M
2012-02-01
Biomarkers and metabolites related to B vitamin function and one-carbon metabolism have been studied as predictors of chronic diseases in studies based on samples stored in biobanks. For most biomarkers, stability data are lacking or fragmentary. Degradation and accumulation kinetics of 32 biomarkers were determined at 23 °C in serum and plasma (EDTA, heparin, and citrate) collected from 16 individuals and stored for up to 8 days. In frozen serum (-25 °C), stability was studied cross-sectionally in 650 archival samples stored for up to 29 years. Concentration vs time curves were fitted to monoexponential, biexponential, linear, and nonlinear models. For many biomarkers, stability was highest in EDTA plasma. Storage effects were similar at room temperature and at -25 °C; notable exceptions were methionine, which could be recovered as methionine sulfoxide, and cystathionine, which decreased in frozen samples. Cobalamin, betaine, dimethylglycine, sarcosine, total homocysteine, total cysteine, tryptophan, asymetric and symmetric dimethyl argenine, creatinine, and methylmalonic acid were essentially stable under all conditions. Most B vitamins (folate and vitamins B2 and B6) were unstable; choline increased markedly, and some amino acids also increased, particularly in serum. The kynurenines showed variable stability. For many biomarkers, degradation (folate and flavin mononucleotide) or accumulation (pyridoxal, riboflavin, choline, amino acids) kinetics at room temperature were non-first order. Data on stability and deterioration kinetics for individual biomarkers are required to optimize procedures for handling serum and plasma, and for addressing preanalytical bias in epidemiological and clinical studies.
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Optimized approaches for quantification of drug transporters in tissues and cells by MRM proteomics.
Prasad, Bhagwat; Unadkat, Jashvant D
2014-07-01
Drug transporter expression in tissues (in vivo) usually differs from that in cell lines used to measure transporter activity (in vitro). Therefore, quantification of transporter expression in tissues and cell lines is important to develop scaling factor for in vitro to in vivo extrapolation (IVIVE) of transporter-mediated drug disposition. Since traditional immunoquantification methods are semiquantitative, targeted proteomics is now emerging as a superior method to quantify proteins, including membrane transporters. This superiority is derived from the selectivity, precision, accuracy, and speed of analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring (MRM) mode. Moreover, LC-MS/MS proteomics has broader applicability because it does not require selective antibodies for individual proteins. There are a number of recent research and review papers that discuss the use of LC-MS/MS for transporter quantification. Here, we have compiled from the literature various elements of MRM proteomics to provide a comprehensive systematic strategy to quantify drug transporters. This review emphasizes practical aspects and challenges in surrogate peptide selection, peptide qualification, peptide synthesis and characterization, membrane protein isolation, protein digestion, sample preparation, LC-MS/MS parameter optimization, method validation, and sample analysis. In particular, bioinformatic tools used in method development and sample analysis are discussed in detail. Various pre-analytical and analytical sources of variability that should be considered during transporter quantification are highlighted. All these steps are illustrated using P-glycoprotein (P-gp) as a case example. Greater use of quantitative transporter proteomics will lead to a better understanding of the role of drug transporters in drug disposition.
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Sureda-Vives, Macià; Morell-Garcia, Daniel; Rubio-Alaejos, Ana; Valiña, Laura; Robles, Juan; Bauça, Josep Miquel
2017-09-01
Osmolality reflects the concentration of all dissolved particles in a body fluid, and its measurement is routinely performed in clinical laboratories for the differential diagnosis of disorders related with the hydrolytic balance regulation, the renal function and in small-molecule poisonings. The aim of the study was to assess the stability of serum, plasma and urine osmolality through time and under different common storage conditions, including delayed centrifugation. Blood and urine samples were collected, and classified into different groups according to several preanalytical variables: serum or plasma lithium-heparin tubes; spun or unspun; stored at room temperature (RT), at 4°C or frozen at -21°C. Aliquots from each group were assayed over time, for up to 14days. Statistical differences were based on three different international performance criteria. Whole blood stability was higher in the presence of anticoagulant. Serum osmolality was stable for 2days at RT and 8days at 4°C, while plasma was less stable when refrigerated. Urine stability was 5days at RT, 4days at 4°C and >14days when frozen. Osmolality may be of great interest for the management of several conditions, such as in case of a delay in the clinical suspicion, or in case of problems in sample collection or processing. The ability to obtain reliable results for samples kept up to 14days also offers the possibility to retrospectively assess baseline values for patients which may require it. Copyright © 2017. Published by Elsevier Inc.
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Dey-Hazra, Emily; Hertel, Barbara; Kirsch, Torsten; Woywodt, Alexander; Lovric, Svjetlana; Haller, Hermann; Haubitz, Marion; Erdbruegger, Uta
2010-01-01
The clinical importance of microparticles resulting from vesiculation of platelets and other blood cells is increasingly recognized, although no standardized method exists for their measurement. Only a few studies have examined the analytical and preanalytical steps and variables affecting microparticle detection. We focused our analysis on microparticle detection by flow cytometry. The goal of our study was to analyze the effects of different centrifugation protocols looking at different durations of high and low centrifugation speeds. We also analyzed the effect of filtration of buffer and long-term freezing on microparticle quantification, as well as the role of Annexin V in the detection of microparticles. Absolute and platelet-derived microparticles were 10- to 15-fold higher using initial lower centrifugation speeds at 1500 × g compared with protocols using centrifugation speeds at 5000 × g (P < 0.01). A clear separation between true events and background noise was only achieved using higher centrifugation speeds. Filtration of buffer with a 0.2 μm filter reduced a significant amount of background noise. Storing samples for microparticle detection at −80°C decreased microparticle levels at days 28, 42, and 56 (P < 0.05 for all comparisons with fresh samples). We believe that staining with Annexin V is necessary to distinguish true events from cell debris or precipitates. Buffers should be filtered and fresh samples should be analyzed, or storage periods will have to be standardized. Higher centrifugation speeds should be used to minimize contamination by smaller size platelets. PMID:21191433
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Garnero, P; Bianchi, F; Carlier, M C; Genty, V; Jacob, N; Kamel, S; Kindermans, C; Plouvier, E; Pressac, M; Souberbielle, J C
2000-01-01
Biochemical markers of bone turnover have been developed over the past 20 years that are more specific for bone tissue than conventional ones such as total alkaline phosphatase and urinary hydroxyproline. They have been widely used in clinical research and in clinical trials of new therapies as secondary end points of treatment efficacy. Most of the interest has been devoted to their use in postmenopausal osteoporosis, a condition characterized by subtle modifications of bone metabolism that cannot be detected readily by conventional markers of bone turnover. Although several recent studies have suggested that biochemical markers may be used for the management of the individual patient in routine clinical practice, this has not been clearly defined and is a matter of debate. Because of the crucial importance to clarify this issue, the Société Francaise de Biologie Clinique prompted an expert committee to summarize the available data and to make recommendations. The following paper includes a review on the biochemical and analytical aspects of the markers of bone formation and resorption and on the sources of variability such as sex, age, menstrual cycle, pregnancy and lactation, physical activity, seasonal variation and effects of diseases and treatments. We will also describe the effects of pre-analytical factors on the measurements of the different markers. Finally based on that review, we will make practical recommendations for the use of these markers in order to minimize the variability of the measurements and improve the clinical interpretation of the data.
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Banks, Peter; Brown, Richard; Laslowski, Alex; Daniels, Yvonne; Branton, Phil; Carpenter, John; Zarbo, Richard; Forsyth, Ramses; Liu, Yan-hui; Kohl, Shane; Diebold, Joachim; Masuda, Shinobu; Plummer, Tim
2017-01-01
Background: Anatomic pathology laboratory workflow consists of 3 major specimen handling processes. Among the workflow are preanalytic, analytic, and postanalytic phases that contain multistep subprocesses with great impact on patient care. A worldwide representation of experts came together to create a system of metrics, as a basis for laboratories worldwide, to help them evaluate and improve specimen handling to reduce patient safety risk. Method: Members of the Initiative for Anatomic Pathology Laboratory Patient Safety (IAPLPS) pooled their extensive expertise to generate a list of metrics highlighting processes with high and low risk for adverse patient outcomes. Results: Our group developed a universal, comprehensive list of 47 metrics for patient specimen handling in the anatomic pathology laboratory. Steps within the specimen workflow sequence are categorized as high or low risk. In general, steps associated with the potential for specimen misidentification correspond to the high-risk grouping and merit greater focus within quality management systems. Primarily workflow measures related to operational efficiency can be considered low risk. Conclusion: Our group intends to advance the widespread use of these metrics in anatomic pathology laboratories to reduce patient safety risk and improve patient care with development of best practices and interlaboratory error reporting programs. PMID:28340232
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Banks, Peter; Brown, Richard; Laslowski, Alex; Daniels, Yvonne; Branton, Phil; Carpenter, John; Zarbo, Richard; Forsyth, Ramses; Liu, Yan-Hui; Kohl, Shane; Diebold, Joachim; Masuda, Shinobu; Plummer, Tim; Dennis, Eslie
2017-05-01
Anatomic pathology laboratory workflow consists of 3 major specimen handling processes. Among the workflow are preanalytic, analytic, and postanalytic phases that contain multistep subprocesses with great impact on patient care. A worldwide representation of experts came together to create a system of metrics, as a basis for laboratories worldwide, to help them evaluate and improve specimen handling to reduce patient safety risk. Members of the Initiative for Anatomic Pathology Laboratory Patient Safety (IAPLPS) pooled their extensive expertise to generate a list of metrics highlighting processes with high and low risk for adverse patient outcomes. : Our group developed a universal, comprehensive list of 47 metrics for patient specimen handling in the anatomic pathology laboratory. Steps within the specimen workflow sequence are categorized as high or low risk. In general, steps associated with the potential for specimen misidentification correspond to the high-risk grouping and merit greater focus within quality management systems. Primarily workflow measures related to operational efficiency can be considered low risk. Our group intends to advance the widespread use of these metrics in anatomic pathology laboratories to reduce patient safety risk and improve patient care with development of best practices and interlaboratory error reporting programs. © American Society for Clinical Pathology 2017.
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Engineering of a miniaturized, robotic clinical laboratory
Nourse, Marilyn B.; Engel, Kate; Anekal, Samartha G.; Bailey, Jocelyn A.; Bhatta, Pradeep; Bhave, Devayani P.; Chandrasekaran, Shekar; Chen, Yutao; Chow, Steven; Das, Ushati; Galil, Erez; Gong, Xinwei; Gessert, Steven F.; Ha, Kevin D.; Hu, Ran; Hyland, Laura; Jammalamadaka, Arvind; Jayasurya, Karthik; Kemp, Timothy M.; Kim, Andrew N.; Lee, Lucie S.; Liu, Yang Lily; Nguyen, Alphonso; O'Leary, Jared; Pangarkar, Chinmay H.; Patel, Paul J.; Quon, Ken; Ramachandran, Pradeep L.; Rappaport, Amy R.; Roy, Joy; Sapida, Jerald F.; Sergeev, Nikolay V.; Shee, Chandan; Shenoy, Renuka; Sivaraman, Sharada; Sosa‐Padilla, Bernardo; Tran, Lorraine; Trent, Amanda; Waggoner, Thomas C.; Wodziak, Dariusz; Yuan, Amy; Zhao, Peter; Holmes, Elizabeth A.
2018-01-01
Abstract The ability to perform laboratory testing near the patient and with smaller blood volumes would benefit patients and physicians alike. We describe our design of a miniaturized clinical laboratory system with three components: a hardware platform (ie, the miniLab) that performs preanalytical and analytical processing steps using miniaturized sample manipulation and detection modules, an assay‐configurable cartridge that provides consumable materials and assay reagents, and a server that communicates bidirectionally with the miniLab to manage assay‐specific protocols and analyze, store, and report results (i.e., the virtual analyzer). The miniLab can detect analytes in blood using multiple methods, including molecular diagnostics, immunoassays, clinical chemistry, and hematology. Analytical performance results show that our qualitative Zika virus assay has a limit of detection of 55 genomic copies/ml. For our anti‐herpes simplex virus type 2 immunoglobulin G, lipid panel, and lymphocyte subset panel assays, the miniLab has low imprecision, and method comparison results agree well with those from the United States Food and Drug Administration‐cleared devices. With its small footprint and versatility, the miniLab has the potential to provide testing of a range of analytes in decentralized locations. PMID:29376134
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Kruse, Niels; Mollenhauer, Brit
2015-11-01
The quantification of α-Synuclein in cerebrospinal fluid (CSF) as a biomarker has gained tremendous interest in the last years. Several commercially available immunoassays are emerging. We here describe the full validation of one commercially available ELISA assay for the quantification of α-Synuclein in human CSF (Covance alpha-Synuclein ELISA kit). The study was conducted within the BIOMARKAPD project in the European initiative Joint Program for Neurodegenerative Diseases (JPND). We investigated the effect of several pre-analytical and analytical confounders: i.e. (1) need for centrifugation of freshly drawn CSF, (2) sample stability, (3) delay of freezing, (4) volume of storage aliquots, (5) freeze/thaw cycles, (6) thawing conditions, (7) dilution linearity, (8) parallelism, (9) spike recovery, and (10) precision. None of these confounders influenced the levels of α-Synuclein in CSF significantly. We found a very high intra-assay precision. The inter-assay precision was lower than expected due to different performances of kit lots used. Overall the validated immunoassay is useful for the quantification of α-Synuclein in human CSF. Copyright © 2015 Elsevier B.V. All rights reserved.
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Engineering of a miniaturized, robotic clinical laboratory.
Nourse, Marilyn B; Engel, Kate; Anekal, Samartha G; Bailey, Jocelyn A; Bhatta, Pradeep; Bhave, Devayani P; Chandrasekaran, Shekar; Chen, Yutao; Chow, Steven; Das, Ushati; Galil, Erez; Gong, Xinwei; Gessert, Steven F; Ha, Kevin D; Hu, Ran; Hyland, Laura; Jammalamadaka, Arvind; Jayasurya, Karthik; Kemp, Timothy M; Kim, Andrew N; Lee, Lucie S; Liu, Yang Lily; Nguyen, Alphonso; O'Leary, Jared; Pangarkar, Chinmay H; Patel, Paul J; Quon, Ken; Ramachandran, Pradeep L; Rappaport, Amy R; Roy, Joy; Sapida, Jerald F; Sergeev, Nikolay V; Shee, Chandan; Shenoy, Renuka; Sivaraman, Sharada; Sosa-Padilla, Bernardo; Tran, Lorraine; Trent, Amanda; Waggoner, Thomas C; Wodziak, Dariusz; Yuan, Amy; Zhao, Peter; Young, Daniel L; Robertson, Channing R; Holmes, Elizabeth A
2018-01-01
The ability to perform laboratory testing near the patient and with smaller blood volumes would benefit patients and physicians alike. We describe our design of a miniaturized clinical laboratory system with three components: a hardware platform (ie, the miniLab) that performs preanalytical and analytical processing steps using miniaturized sample manipulation and detection modules, an assay-configurable cartridge that provides consumable materials and assay reagents, and a server that communicates bidirectionally with the miniLab to manage assay-specific protocols and analyze, store, and report results (i.e., the virtual analyzer). The miniLab can detect analytes in blood using multiple methods, including molecular diagnostics, immunoassays, clinical chemistry, and hematology. Analytical performance results show that our qualitative Zika virus assay has a limit of detection of 55 genomic copies/ml. For our anti-herpes simplex virus type 2 immunoglobulin G, lipid panel, and lymphocyte subset panel assays, the miniLab has low imprecision, and method comparison results agree well with those from the United States Food and Drug Administration-cleared devices. With its small footprint and versatility, the miniLab has the potential to provide testing of a range of analytes in decentralized locations.
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The value of cell-free DNA for molecular pathology.
Stewart, Caitlin M; Kothari, Prachi D; Mouliere, Florent; Mair, Richard; Somnay, Saira; Benayed, Ryma; Zehir, Ahmet; Weigelt, Britta; Dawson, Sarah-Jane; Arcila, Maria E; Berger, Michael F; Tsui, Dana Wy
2018-04-01
Over the past decade, advances in molecular biology and genomics techniques have revolutionized the diagnosis and treatment of cancer. The technological advances in tissue profiling have also been applied to the study of cell-free nucleic acids, an area of increasing interest for molecular pathology. Cell-free nucleic acids are released from tumour cells into the surrounding body fluids and can be assayed non-invasively. The repertoire of genomic alterations in circulating tumour DNA (ctDNA) is reflective of both primary tumours and distant metastatic sites, and ctDNA can be sampled multiple times, thereby overcoming the limitations of the analysis of single biopsies. Furthermore, ctDNA can be sampled regularly to monitor response to treatment, to define the evolution of the tumour genome, and to assess the acquisition of resistance and minimal residual disease. Recently, clinical ctDNA assays have been approved for guidance of therapy, which is an exciting first step in translating cell-free nucleic acid research tests into clinical use for oncology. In this review, we discuss the advantages of cell-free nucleic acids as analytes in different body fluids, including blood plasma, urine, and cerebrospinal fluid, and their clinical applications in solid tumours and haematological malignancies. We will also discuss practical considerations for clinical deployment, such as preanalytical factors and regulatory requirements. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Strohbehn, Garth W; Pan, Warren W; Petrilli, Christopher M; Heidemann, Lauren; Larson, Sophia; Aaronson, Keith D; Johnson, Matt; Ellies, Tammy; Heung, Michael
2018-04-30
Inpatient tacrolimus therapeutic drug monitoring (TDM) lacks standardized guidelines. In this study, the authors analyzed variability in the pre-analytical phase of the inpatient tacrolimus TDM process at their institution. Patients receiving tacrolimus (twice-daily formulation) and tacrolimus laboratory analysis were included in the study. Times of tacrolimus administration and laboratory study collection were extracted and time distribution plots for each step in the inpatient TDM process were generated. Trough levels were drawn appropriately in 25.9% of the cases. Timing between doses was consistent, with 91.9% of the following dose administrations occurring 12 +/- 2 hours after the previous dose. Only 38.1% of the drug administrations occurred within one hour of laboratory study collection. Tacrolimus-related patient safety events were reported at a rate of 1.9 events per month while incorrect timing of TDM sample collection occurred approximately 200 times per month. Root cause analysis identified a TDM process marked by a lack of communication and coordination of drug administration and TDM sample collection. Extrapolating findings nationwide, we estimate $22 million in laboratory costs wasted annually. Based on this large single-center study, the authors concluded that the inpatient TDM process is prone to timing errors, thus is financially wasteful, and at its worst harmful to patients due to clinical decisions being made on the basis of unreliable data. Further work is needed on systems solutions to better align the laboratory study collection and drug administration processes.
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Raz, Sabina Rebe; Marchesini, Gerardo R; Bremer, Maria G E G; Colpo, Pascal; Garcia, Cesar Pascual; Guidetti, Guido; Norde, Willem; Rossi, Francois
2012-11-21
We present a novel approach to tackle the most common drawback of using surface plasmon resonance for analyte screening in complex biological matrices--the nonspecific binding to the sensor chip surface. By using a perforated membrane supported by a polymeric gel structure at the evanescent wave penetration depth, we have fabricated a non-fouling sieve above the sensing region. The sieve shields the evanescent wave from nonspecific interactions which interfere with SPR sensing by minimizing the fouled area of the polymeric gel and preventing the translocation of large particles, e.g. micelles or aggregates. The nanopatterned macropores were fabricated by means of colloidal lithography and plasma enhanced chemical vapor deposition of a polyethylene oxide-like film on top of a polymeric gel matrix commonly used in surface plasmon resonance analysis. The sieve was characterized using surface plasmon resonance imaging, contact angle, atomic force microscopy and scanning electron microscopy. The performance of the sieve was studied using an immunoassay for detection of antibiotic residues in full fat milk and porcine serum. The non-fouling membrane presented pores in the 92-138 nm range organized in a hexagonal crystal lattice with a clearance of about 5% of the total surface. Functionally, the membrane with the nanopatterned macropores showed significant improvements in immunoassay robustness and sensitivity in untreated complex samples. The utilization of the sensor built-in sieve for measurements in complex matrices offers reduction in pre-analytical sample preparation steps and thus shortens the total analysis time.
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Towards a routine application of Top-Down approaches for label-free discovery workflows.
Schmit, Pierre-Olivier; Vialaret, Jerome; Wessels, Hans J C T; van Gool, Alain J; Lehmann, Sylvain; Gabelle, Audrey; Wood, Jason; Bern, Marshall; Paape, Rainer; Suckau, Detlev; Kruppa, Gary; Hirtz, Christophe
2018-03-20
Thanks to proteomics investigations, our vision of the role of different protein isoforms in the pathophysiology of diseases has largely evolved. The idea that protein biomarkers like tau, amyloid peptides, ApoE, cystatin, or neurogranin are represented in body fluids as single species is obviously over-simplified, as most proteins are present in different isoforms and subjected to numerous processing and post-translational modifications. Measuring the intact mass of proteins by MS has the advantage to provide information on the presence and relative amount of the different proteoforms. Such Top-Down approaches typically require a high degree of sample pre-fractionation to allow the MS system to deliver optimal performance in terms of dynamic range, mass accuracy and resolution. In clinical studies, however, the requirements for pre-analytical robustness and sample size large enough for statistical power restrict the routine use of a high degree of sample pre-fractionation. In this study, we have investigated the capacities of current-generation Ultra-High Resolution Q-Tof systems to deal with high complexity intact protein samples and have evaluated the approach on a cohort of patients suffering from neurodegenerative disease. Statistical analysis has shown that several proteoforms can be used to distinguish Alzheimer disease patients from patients suffering from other neurodegenerative disease. Top-down approaches have an extremely high biological relevance, especially when it comes to biomarker discovery, but the necessary pre-fractionation constraints are not easily compatible with the robustness requirements and the size of clinical sample cohorts. We have demonstrated that intact protein profiling studies could be run on UHR-Q-ToF with limited pre-fractionation. The proteoforms that have been identified as candidate biomarkers in the-proof-of concept study are derived from proteins known to play a role in the pathophysiology process of Alzheimer disease. Copyright © 2017 Elsevier B.V. All rights reserved.
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Ilie, Marius; Nunes, Manoel; Blot, Lydia; Hofman, Véronique; Long-Mira, Elodie; Butori, Catherine; Selva, Eric; Merino-Trigo, Ana; Vénissac, Nicolas; Mouroux, Jérôme; Vrignaud, Patricia; Hofman, Paul
2015-02-01
With the ongoing need to improve therapy for non-small cell lung cancer (NSCLC) there has been increasing interest in developing reliable preclinical models to test novel therapeutics. Patient-derived tumor xenografts (PDX) are considered to be interesting candidates. However, the establishment of such model systems requires highly specialized research facilities and introduces logistic challenges. We aimed to establish an extensive well-characterized panel of NSCLC xenograft models in the context of a long-distance research network after careful control of the preanalytical steps. One hundred fresh surgically resected NSCLC specimens were shipped in survival medium at room temperature from a hospital-integrated biobank to animal facilities. Within 24 h post-surgery, tumor fragments were subcutaneously xenografted into immunodeficient mice. PDX characterization was performed by histopathological, immunohistochemical, aCGH and next-generation sequencing approaches. For this model system, the tumor take rate was 35%, with higher rates for squamous carcinoma (60%) than for adenocarcinoma (13%). Patients for whom PDX tumors were obtained had a significantly shorter disease-free survival (DFS) compared to patients for whom no PDX tumors (P = 0.039) were obtained. We established a large panel of PDX NSCLC models with a high frequency of mutations (29%) in EGFR, KRAS, NRAS, MEK1, BRAF, PTEN, and PI3KCA genes and with gene amplification (20%) of c-MET and FGFR1. This new patient-derived NSCLC xenograft collection, established regardless of the considerable time required and the distance between the clinic and the animal facilities, recapitulated the histopathology and molecular diversity of NSCLC and provides stable and reliable preclinical models for human lung cancer research. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.
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Cook, Andrea M; Moritz, Andreas; Freeman, Kathleen P; Bauer, Natali
2016-09-01
Scarce information exists about quality requirements and objective evaluation of performance of large veterinary bench top hematology analyzers. The study was aimed at comparing the observed total error (TEobs ) derived from meta-analysis of published method validation data to the total allowable error (TEa ) for veterinary hematology variables in small animals based on experts' opinions. Ideally, TEobs should be < TEa . An online survey was sent to veterinary experts in clinical pathology and small animal internal medicine for providing the maximal allowable deviation from a given result for each variable. Percent of TEa = (allowable median deviation/clinical threshold) * 100%. Second, TEobs for 3 laser-based bench top hematology analyzers (ADVIA 2120; Sysmex XT2000iV, and CellDyn 3500) was calculated based on method validation studies published between 2005 and 2013 (n = 4). The percent TEobs = 2 * CV (%) + bias (%). The CV was derived from published studies except for the ADVIA 2120 (internal data), and bias was estimated from the regression equation. A total of 41 veterinary experts (19 diplomates, 8 residents, 10 postgraduate students, 4 anonymous specialists) responded. The proposed range of TEa was wide, but generally ≤ 20%. The TEobs was < TEa for all variables and analyzers except for canine and feline HGB (high bias, low CV) and platelet counts (high bias, high CV). Overall, veterinary bench top analyzers fulfilled experts' requirements except for HGB due to method-related bias, and platelet counts due to known preanalytic/analytic issues. © 2016 American Society for Veterinary Clinical Pathology.
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Sadilkova, Lenka; Paluch, Zoltan; Mottlova, Jirina; Bednar, Frantisek; Alusik, Stefan
2012-01-01
Thromboxane B2 (TxB2) and particularly 11-dehydrothromboxane B2 (11-dTxB2) are widely used as prognostic risk markers of platelet activation in cardiovascular diseases. The main errors in TxB2 and 11-dTxB2 determination include either low concentrations of circulating TxB2 (1 - 2 pg/mL) and 11-dTxB2 (0.9 - 4.3 pg/mL) or rather high transiency (mean TxB2 half-life is approximately 5 minutes) as well as an incorrect pre-analytical phase set up. The aim of this study was to investigate the impact of a widely used purification step on the results of enzyme immunosorbent assay (EIA)--based measurement of the two selected thromboxanes. For the purpose of this study, 20 plasma samples (10 healthy donors, 10 patients under treatment with acetylsalicylic acid) were screened for TxB2 and 11-dTxB2 concentrations using commercial competitive EIA kits (Cayman Chemicals, Tallinn, Estonia; Neogen, Lexington, KY, USA) with or without the introduction of the purification procedure. The purification step does not significantly affect the results of EIA measurements of the two of TxA2 metabolites (TxB2, 11-dTxB2) in human plasma. The levels of TxB2 and 11-dTxB2 determined in the plasma samples were not significantly changed (p < 0.05) when the purification step was omitted compared to the purified samples. This study establishes a protocol allowing for reliable and reproducible plasma TxB2 and 11-dTxB2 EIA measurement for routine basic screening of platelet function.
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Sancesario, Giulia M; Esposito, Zaira; Nuccetelli, Marzia; Bernardini, Sergio; Sorge, Roberto; Martorana, Alessandro; Federici, Giorgio; Bernardi, Giorgio; Sancesario, Giuseppe
2010-06-01
Amyloid-beta 1-42 (Abeta1-42), peptide detectable in cerebrospinal fluid (CSF), has been extensively studied as diagnostic marker for Alzheimer's disease; however, results are variable. We investigated whether Abeta1-42 detection in CSF may be affected by handling temperature after lumbar puncture. CSF was collected from patients affected by probable AD (n=27), other dementias (OD) (n=24), or other neurological disorders without cognitive impairment (OND) (n=23). After lumbar puncture, CSF samples were either maintained at 37 degrees C, or handled according to standard procedures and centrifuged at 4 degrees C for 10 min; thereafter, one aliquot was further stored at 4 degrees C and another at 37 degrees C, before freezing all samples 90 min later at -80 degrees C, pending analysis. Abeta1-42 and total tau were determined using a commercially available sandwich enzyme-linked immunosorbent assay ELISA. Reduced Abeta1-42 and increased total tau CSF levels were confirmed as characteristic hallmarks of the OD and AD groups, providing standard measurement in samples stored at 4 degrees C before freezing. However, avoiding cooling or reheating CSF from 4 to 37 degrees C before freezing strikingly increased the Abeta1-42 concentration detectable in the AD group (P<0.01), but not in control groups. The results indicate that a pool of Abeta1-42 cannot be detectable in the CSF of AD patients, because standard preanalytical cooling masks in some ways the epitope recognized by Abeta1-42 specific antibodies. Moreover, our study suggests that low temperature could induce Abeta1-42 conformational changes and multimeric aggregates in probable AD, but, more importantly, Abeta1-42 aggregation could be reversible. Copyright (c) 2009 Elsevier Inc. All rights reserved.
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Tang, Ning; Jin, Xi; Sun, Ziyong; Jian, Cui
2017-04-01
The effects of hemolysis and lipemia on thromboelastography (TEG) analysis have been scarcely evaluated in human samples, and neglected in clinical practice. We aimed to investigate the effects of in vitro mechanical hemolysis and lipemia on TEG analysis and conventional coagulation tests. Twenty-four healthy volunteers were enrolled in the study. Besides the controls, three groups with slight, moderate and severe mechanical hemolysis were constituted according to free hemoglobin (Hb) concentrations of 0.5-1.0, 2.0-6.0 and 7.0-13.0 g/L, respectively; and three groups with mild, moderate and high lipemia were established according to triglyceride concentrations of ∼6.0, ∼12.0, and ∼18.0 mmol/L, respectively. Four TEG parameters, reaction time (R), coagulation time (K), angle (α), and maximum amplitude (MA), were measured alongside conventional plasma tests including prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FIB) by mechanical method, and platelet count by optical method. Results showed that the median R and MA values at moderate and severe hemolysis and K at severe hemolysis exceeded respective reference intervals, and were considered unacceptable. Median values of TEG parameters in lipemic samples were all within reference intervals. Bias values of conventional plasma tests PT, APTT and FIB in hemolyzed or lipemic samples were all lower than the Clinical Laboratory Improvement Amendments (CLIA) allowable limits. Bias values of platelet count at moderate to severe hemolysis and lipemia exceeded the CLIA allowable limits. In conclusion, the detection of TEG was in general more affected by mechanical hemolysis than plasma coagulation tests. Pre-analytical variables should be taken into account when unexpected TEG results are obtained.
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Use of allogeneic apheresis stem cell products as an interlaboratory proficiency challenge.
Cooling, Laura; Roxbury, Kelly; Hoffmann, Sandra; DeBusscher, Joan; Kota, Usha; Goldstein, Steven; Davenport, Robertson
2017-06-01
AABB Standards requires that laboratories participate in a proficiency test (PT) program for critical analytes. Institutions can purchase commercial PT materials; however, PT can also be performed through interlaboratory exchange. We investigated the utility of allogeneic hematopoietic progenitor cell apheresis (HPC-A) products as an interlaboratory PT challenge for total nucleated cell count (TNC) and CD34 assessment. Three-year retrospective and comparative review of unrelated allogeneic HPC-A products received by the University of Michigan between January 2011 and December 2013. Internal TNC and CD34 count were compared to the external collecting facility by paired t test and linear regression. The absolute and percent difference between external and internal counts and 95% limits of agreeability (95% LA) were determined. Results were analyzed relative to donor center location (international, domestic), time zone (domestic), and calendar year. There was a strong correlation between internal and external TNC, regardless of donor center location or year. For CD34, there was a good correlation between centers (R = 0.88-0.91; slope = 0.95-0.98x) with a median difference of -1% (95% LA, -50%, +47%). This was considerably better than commercial PT challenges, which showed a persistent negative bias for absolute CD34 and CD3 counts. Allogeneic HPC-A products represent an interlaboratory PT exchange for all critical analytes, including TNC and CD34 count, cell viability, and sterility. Allogeneic HPC-A products, which are fresh and transported under validated conditions, are less subject to preanalytical variables that may impact commercial PT samples such as aliquoting and sample homogeneity, commercial additives, and sample stability during manufacturing and transport. © 2017 AABB.
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Adhesive blood microsampling systems for steroid measurement via LC-MS/MS in the rat.
Heussner, Kirsten; Rauh, Manfred; Cordasic, Nada; Menendez-Castro, Carlos; Huebner, Hanna; Ruebner, Matthias; Schmidt, Marius; Hartner, Andrea; Rascher, Wolfgang; Fahlbusch, Fabian B
2017-04-01
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) allows for the direct analysis of multiple hormones in a single probe with minimal sample volume. Rodent-based animal studies strongly rely on microsampling, such as the dry blood spot (DBS) method. However, DBS suffers the drawback of hematocrit-dependence (non-volumetric). Hence, novel volumetric microsampling techniques were introduced recently, allowing sampling of fixed accurate volumes. We compared these methods for steroid analysis in the rat to improve inter-system comparability. We analyzed steroid levels in blood using the absorptive microsampling devices Whatman® 903 Protein Saver Cards, Noviplex™ Plasma Prep Cards and the Mitra™ Microsampling device and compared the obtained results to the respective EDTA plasma levels. Quantitative steroid analysis was performed via LC-MS/MS. For the determination of the plasma volume factor for each steroid, their levels in pooled blood samples from each human adults and rats (18weeks) were compared and the transferability of these factors was evaluated in a new set of juvenile (21days) and adult (18weeks) rats. Hematocrit was determined concomitantly. Using these approaches, we were unable to apply one single volume factor for each steroid. Instead, plasma volume factors had to be adjusted for the recovery rate of each steroid and device individually. The tested microsampling systems did not allow the use of one single volume factor for adult and juvenile rats based on an unexpectedly strong hematocrit-dependency and other steroid specific (pre-analytic) factors. Our study provides correction factors for LC-MS/MS steroid analysis of volumetric and non-volumetric microsampling systems in comparison to plasma. It argues for thorough analysis of chromatographic effects before the use of novel volumetric systems for steroid analysis. Copyright © 2017 Elsevier Inc. All rights reserved.
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The mandate for a proper preservation in histopathological tissues.
Comănescu, Maria; Arsene, D; Ardeleanu, Carmen; Bussolati, G
2012-01-01
A sequence of technically reproducible procedures is mandatory to guarantee a proper preservation of tissues and to build up the basis for sound diagnoses. However, while the goal of these procedures was, until recently, to assure only structural (histological and cytological) preservation, an appropriate preservation of antigenic properties and of nucleic acid integrity is now additionally requested, in order to permit pathologists to provide the biological information necessary for the adoption of personalized therapies. The present review analyses the sequence of technical steps open to critical variations. Passages such as dehydration, paraffin embedding, sectioning and staining are relatively well standardized and allow adoption of dedicated (automatic) apparatuses, while other pre-analytical steps, i.e. time and modalities of transfer of surgical specimens from the surgical theatre to the pathology laboratory (s.c. "ischemia time") and the type and length of fixation are not standardized and are a potential cause of discrepancies in diagnostic results. Our group is involved in European-funded projects tackling these problems with the concrete objective of implementing a model of effective tumors investigations by high performance genetic and molecular methodologies. The problem of the discrepant quality level of histopathological and cytological preparations involved five European countries and exploiting the potential of "virtual slide technology". Concrete issues, techniques and pitfalls, as well as proposed guidelines for processing the tissues are shown in this presentation.
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A review of human biomonitoring in selected Southeast Asian countries.
Barnett-Itzhaki, Zohar; Esteban López, Marta; Puttaswamy, Naveen; Berman, Tamar
2018-07-01
Rapid development and industrialization in Southeast (SE) Asia has led to environmental pollution, potentially exposing the general population to environmental contaminants. Human biomonitoring (HBM), measurement of chemical and/or their metabolites in human tissues and fluids, is an important tool for assessing cumulative exposure to complex mixtures of chemicals and for monitoring chemical exposures in the general population. While there are national HBM programs in several developed countries, there are no such national programs in most of the SE Asian countries. However, in recent years there has been progress in the field of HBM in many of the SE Asian countries. In this review, we present recent HBM studies in five selected SE Asian countries: Bangladesh, Indonesia, Malaysia, Myanmar and Thailand. While there is extensive HBM research in several SE Asian countries, such as Thailand, in other countries HBM studies are limited and focus on traditional environmental pollutants (such as lead, arsenic and mercury). Further development of this field in SE Asia would be benefited by establishment of laboratory capacity, improving quality control and assurance, collaboration with international experts and consortiums, and sharing of protocols and training both for pre-analytical and analytical phases. This review highlights the impressive progress in HBM research in selected SE Asian countries and provides recommendations for development of this field. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Lima-Oliveira, G; Salvagno, G L; Danese, E; Favaloro, E J; Guidi, G C; Lippi, G
2015-06-01
The potential cross-contamination of additives between primary blood tubes is a well-known problem during sample collection. The aim of this study was to assess the impact of citrated blood contamination with different amounts of dipotassium ethylenediaminetetraacetic (K2 EDTA blood) on activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen. Blood was collected from 15 ostensibly healthy volunteers into four 0.109 m citrate blood tubes followed by one K2 EDTA blood tube. The citrate tubes of each subject were pooled and divided in five aliquots. The whole blood of the K2 EDTA tube was then added in scalar amounts to autologous citrated blood aliquots, to obtain K2 EDTA contamination ranging from 0% to 43%, and thus mimic potential pre-analytical contamination. A statistically and clinically significant prolongation was observed for both APTT and PT between 29% and 43% K2 EDTA contamination, whereas the decrease of fibrinogen values became statistically and clinically significant at 43% K2 EDTA contamination. The results of this investigation show that contamination of citrated blood with as much as 29% of K2 EDTA blood generates a significant bias in results of routine clotting assays. This has serious implications for patient safety and management. © 2014 John Wiley & Sons Ltd.
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Dromigny, Jacques-Albert; Robert, Emmanuel
2017-08-01
To comply with the pre-analytical requirements of ISO EN 15189, we investigated the stability of potassium, a very critical and sensitive analyte. We took into count effects of duration, temperature and transport after 10 hours storage of human whole blood in serum and plasma. Blood of 12 healthy subjects was analyzed after 4, 6, 8 and 10 hours of storage. Three study groups were designed: samples stored in laboratory at room temperature, transported by car during 4 hours at a temperature of 21±1̊C, with or without previous thermal shock (20 min at 4±1 ̊C) before transportation. Variations in concentration were expressed as mean bias from baseline using the analytical change limit (ACL) and the reference change value (RCV). Using RCV, we considered that potassium was biologically stable during 10 hours whatever our study groups. Considering ACL, potassium in serum was not stable after the thermal shock. We conclude that whole blood in lithium-heparin tubes may be used for routine potassium analysis even if long car transportation and previous thermal shock is involved. It confirms that potassium analysis can be still performed in locations distant from a medical laboratory.
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Nails in Forensic Toxicology: An Update.
Solimini, Renata; Minutillo, Adele; Kyriakou, Chrystalla; Pichini, Simona; Pacifici, Roberta; Busardo, Francesco Paolo
2017-01-01
The analysis of nails as a keratinized matrix to detect drugs or illicit substances has been increasingly used in forensic and clinical toxicology as a complementary test, especially for the specific characteristics of stably accumulating substances for long periods of time. This allows a retrospective investigation of chronic drug abuse, monitoring continuous drug or pharmaceutical use, reveal in utero drug exposure or environmental exposures. We herein review the recent literature investigating drug incorporation mechanisms and drug detection in nails for forensic toxicological purposes. Mechanisms of drug incorporation have not yet been fully elucidated. However, some research has lately contributed to a better understanding of how substances are incorporated into nails, suggesting three potential mechanisms of drug incorporation: contamination from sweat, incorporation from nail bed and incorporation from germinal matrix. In addition, numerous methods dealing with the determination of drugs of abuse, medications and alcohol biomarkers in nails have been reported in studies over the years. The latter methods could find application in clinical and forensic toxicology. The studies herein reviewed point out how important it is to standardize and harmonize the methodologies (either pre-analytical or analytical) for nails analysis and the optimization of sampling as well as the development of proficiency testing programs and the determination of cut-off values. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
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La Gioia, Antonio; Fumi, Maurizio; Fiorini, Fabiana; Pezzati, Paola; Balboni, Fiamma; Bombara, Maria; Marini, Alessandra; Pancione, Ylenia; Solarino, Leonardo; Marchese, Elisa; Sale, Silvia; Rocco, Vincenzo; Fiorini, Marcello
2018-03-13
The presence of cold agglutinin in blood samples can cause a spontaneous agglutination of red blood cells (RBCs) when low temperature occurs. This phenomenon causes a spurious lowering of RBC count on the automated haematological analysers that are detected by incongruous values (≥370 g/L) of the mean cellular haemoglobi concentration (MCHC). A preheating at 37°C can remove the RBC agglutination generally resulting in a reliable count. It has been reported that the same result can be reached by using the optical reticulocyte (RET) channel of Sysmex analysers where the RBC count is not influenced by the presence of cold agglutinin. This study aims to evaluate these data in a larger population, with regard to environmental conditions on Sysmex analysers. We have also evaluated the influence of different thermal pretreatments on the RBC count. This study was performed on 96 remnants of peripheral blood samples (48 with MCHC in normal range and 48 with MCHC > 370 g/L) which have been analysed in different preanalytical conditions on the Sysmex analysers. A preheating of samples at 41°C for 1 min leads to a reversibility of the cold agglutination comparable to the one observed in the RET channel and yields better results compared with 37°C for 2 hours. None of described procedures assure the complete cold agglutination reversibility in every case. Consequently, since the haematological analysers not yet provide reliable parameters to confirm the complete resolution of agglutination, further verification of RBC count accuracy needs to be performed. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
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Normanno, Nicola; Denis, Marc G.; Thress, Kenneth S.; Ratcliffe, Marianne; Reck, Martin
2017-01-01
Cancer treatment is evolving towards therapies targeted at specific molecular abnormalities that drive tumor growth. Consequently, to determine which patients are eligible, accurate assessment of molecular aberrations within tumors is required. Obtaining sufficient tumor tissue for molecular testing can present challenges; therefore, circulating free tumor-derived DNA (ctDNA) found in blood plasma has been proposed as an alternative source of tumor DNA. The diagnostic utility of ctDNA for the detection of epidermal growth factor receptor (EGFR) mutations harbored in tumors of patients with advanced non-small-cell lung cancer (NSCLC) is supported by the results of several large studies/meta-analyses. However, recent real-world studies suggest that the performance of ctDNA testing varies between geographic regions/laboratories, demonstrating the need for standardized guidance. In this review, we outline recommendations for obtaining an accurate result using ctDNA, relating to pre-analytical plasma processing, ctDNA extraction, and appropriate EGFR mutation detection methods, based on clinical trial results. We conclude that there are several advantages associated with ctDNA, including the potential for repeated sampling particularly following progression after first-line tyrosine kinase inhibitor (TKI) therapy, as TKIs targeting resistance mutations (eg T790M) are now approved for use in the USA/EU/Japan (at time of writing). However, evidence suggests that ctDNA does not allow detection of EGFR mutations in all patients with known mutation-positive NSCLC. Therefore, although tumor tissue should be the first sample choice for EGFR testing at diagnosis, ctDNA is a promising alternative diagnostic approach. PMID:27980215
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CSF beta-amyloid 1–42 – what are we measuring in Alzheimer's disease?
Hu, William T; Watts, Kelly D; Shaw, Leslie M; Howell, Jennifer C; Trojanowski, John Q; Basra, Sundeep; Glass, Jonathan D; Lah, James J; Levey, Allan I
2015-01-01
Objective To characterize biological and technical factors which influence cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarker levels, including the presence of apolipoprotein E (APOE) ε4 allele, AD diagnosis, Aβ-binding proteins, sample processing, and preanalytical handling. Methods CSF was collected from 140 subjects with normal cognition, mild cognitive impairment, AD, and non-AD dementia. CSF levels of beta-amyloid 1–42 (Aβ42), total Tau (t-Tau), and Tau phosphorylated at threonine 181 (p-Tau181) were analyzed following the standard and modified protocols. CSF levels of apoJ, apoE, albumin, and α-synuclein were measured in a subgroup (n = 69), and their effects on measured AD biomarker levels were also determined in vitro using human CSF samples. Results CSF Aβ42 levels measured using the AD Neuro-imaging Initiative (ADNI) protocol (which we call suspended Aβ42 or susAβ) were lower than total measurable CSF Aβ42 in all groups, and on average represents 57% of the latter. Logistic regression analysis showed this proportion (% susAβ) to be directly correlated with CSF Aβ42 and apoJ levels, but inversely correlated with CSF t-Tau levels. Finally, we showed in vitro that increasing apoE and apoJ levels directly increased % susAβ. Conclusion CSF susAβ levels are influenced by biological and technical factors, and may represent a marker of Aβ susceptible to lipoprotein-mediated clearance. Clinical trials should include total measurable Aβ42 and susAβ to better inform outcomes. PMID:25750918
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Risch, Martin; Nydegger, Urs; Risch, Lorenz
2017-01-01
In clinical practice, laboratory results are often important for making diagnostic, therapeutic, and prognostic decisions. Interpreting individual results relies on accurate reference intervals and decision limits. Despite the considerable amount of resources in clinical medicine spent on elderly patients, accurate reference intervals for the elderly are rarely available. The SENIORLAB study set out to determine reference intervals in the elderly by investigating a large variety of laboratory parameters in clinical chemistry, hematology, and immunology. The SENIORLAB study is an observational, prospective cohort study. Subjectively healthy residents of Switzerland aged 60 years and older were included for baseline examination (n = 1467), where anthropometric measurements were taken, medical history was reviewed, and a fasting blood sample was drawn under optimal preanalytical conditions. More than 110 laboratory parameters were measured, and a biobank was set up. The study participants are followed up every 3 to 5 years for quality of life, morbidity, and mortality. The primary aim is to evaluate different laboratory parameters at age-related reference intervals. The secondary aims of this study include the following: identify associations between different parameters, identify diagnostic characteristics to diagnose different circumstances, identify the prevalence of occult disease in subjectively healthy individuals, and identify the prognostic factors for the investigated outcomes, including mortality. To obtain better grounds to justify clinical decisions, specific reference intervals for laboratory parameters of the elderly are needed. Reference intervals are obtained from healthy individuals. A major obstacle when obtaining reference intervals in the elderly is the definition of health in seniors because individuals without any medical condition and any medication are rare in older adulthood. Reference intervals obtained from such individuals cannot be considered representative for seniors in a status of age-specific normal health. In addition to the established methods for determining reference intervals, this longitudinal study utilizes a unique approach, in that survival and long-term well-being are taken as indicators of health in seniors. This approach is expected to provide robust and representative reference intervals that are obtained from an adequate reference population and not a collective of highly selected individuals. The present study was registered under International Standard Randomized Controlled Trial Number registry: ISRCTN53778569.
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Pre-analytical stability of the plasma proteomes based on the storage temperature
2013-01-01
Background This study examined the effect of storage temperature on the protein profile of human plasma. Plasma samples were stored for 13 days at -80°C, -20°C, +4°C and room temperature (20-25°C) prior to proteomic analysis. The proteomic comparisons were based on the differences of mean intensity values of protein spots between fresh plasma samples (named “time zero”) and plasma samples stored at different temperatures. To better understand the thermally induced biochemical changes that may affect plasma proteins during storage we identified proteins with different expressions with respect to the time zero sample. Results Using two-dimensional electrophoresis followed by MALDI-TOF MS and /or LC-MS/MS 20 protein spots representing 10 proteins were identified with significant differences in abundance when stored at different temperatures. Our results, in agreement with various authors, indicate that during storage for a short period (13 days) at four different temperatures plasma proteins were more affected by degradation processes at +4°C compared to the other temperatures analysed. However, we founded that numerous protein spots (vitamin D binding protein, alpha-1-antitrypsin, serotransferrin, apoplipoprotein A-I, apolipoprotein E, haptoglobin and complement factor B) decrease in abundance with increasing temperature up to 4°C, but at room temperature their intensity mean values are similar to those of time zero and -80°C. We hypothesize that these proteins are labile at 4°C, but at the same time they are stable at room temperature (20-25°C). Furthermore we have grouped the proteins based on their different sensitivity to the storage temperature. Spots of serum albumin, fibrinogen gamma chain and haptoglobin are more resistant to the higher temperatures tested, as they have undergone changes in abundance only at room temperature; conversely, other spots of serum albumin, fibrinogen beta chain and serotransferrin are more labile as they have undergone changes in abundance at all temperatures except at -80°C. Conclusions Although there are many studies concerning protein stability of clinical samples during storage these findings may help to provide a better understanding of the changes of proteins induced by storage temperature. PMID:23518135
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Reproducibility of Interferon Gamma (IFN-γ) Release Assays. A Systematic Review
Tagmouti, Saloua; Slater, Madeline; Benedetti, Andrea; Kik, Sandra V.; Banaei, Niaz; Cattamanchi, Adithya; Metcalfe, John; Dowdy, David; van Zyl Smit, Richard; Dendukuri, Nandini
2014-01-01
Rationale: Interferon gamma (IFN-γ) release assays for latent tuberculosis infection result in a larger-than-expected number of conversions and reversions in occupational screening programs, and reproducibility of test results is a concern. Objectives: Knowledge of the relative contribution and extent of the individual sources of variability (immunological, preanalytical, or analytical) could help optimize testing protocols. Methods: We performed a systematic review of studies published by October 2013 on all potential sources of variability of commercial IFN-γ release assays (QuantiFERON-TB Gold In-Tube and T-SPOT.TB). The included studies assessed test variability under identical conditions and under different conditions (the latter both overall and stratified by individual sources of variability). Linear mixed effects models were used to estimate within-subject SD. Measurements and Main Results: We identified a total of 26 articles, including 7 studies analyzing variability under the same conditions, 10 studies analyzing variability with repeat testing over time under different conditions, and 19 studies reporting individual sources of variability. Most data were on QuantiFERON (only three studies on T-SPOT.TB). A considerable number of conversions and reversions were seen around the manufacturer-recommended cut-point. The estimated range of variability of IFN-γ response in QuantiFERON under identical conditions was ±0.47 IU/ml (coefficient of variation, 13%) and ±0.26 IU/ml (30%) for individuals with an initial IFN-γ response in the borderline range (0.25–0.80 IU/ml). The estimated range of variability in noncontrolled settings was substantially larger (±1.4 IU/ml; 60%). Blood volume inoculated into QuantiFERON tubes and preanalytic delay were identified as key sources of variability. Conclusions: This systematic review shows substantial variability with repeat IFN-γ release assays testing even under identical conditions, suggesting that reversions and conversions around the existing cut-point should be interpreted with caution. PMID:25188809
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Skopp, Gisela; Pötsch, Lucia
2004-01-01
Preanalytical stability of a drug and its major metabolites is an important consideration in pharmacokinetic studies or whenever the analyte pattern is used to estimate drug habits. Firstly, the stability of free and glucuronidated 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid (THCCOOH, THCCOOglu) in authentic urine samples was investigated. Random urine samples of cannabis users (n = 38) were stored at -20, 4, and 20 degrees C up to 15 days and up to 5 days at 40 degrees C, and alterations of the analyte pattern during storage were followed by liquid chromatography-tandem mass spectrometry. Secondly, the influence of pH (range 5.0-8.0) on the stability of the analytes was studied using spiked urine to elucidate the results obtained from authentic samples. In authentic urine samples, the initial pH ranged from 5.1 to 8.8. The glucuronide was found to be highly labile at a storage temperature of 4 degrees C and above. Initially, 18 urine samples tested positive for THCCOOH. After 2 days storage at 20 degrees C, THCCOOH was detectable in a further 4 samples, and 7 more samples tested positive for THCCOOH (5-81 ng/mL) after 15 days. Depending on time and temperature, the glucuronide concentration decreased, resulting in an increase of THCCOOH concentration. However, a loss in mean total THCCOOH concentration was found, which was significantly higher in deteriorated samples than in samples without signs of deterioration after 15 days of storage at 20 degrees C. In the drug-free urine sample separately spiked with THCCOOglu or THCCOOH, the investigations on the stability of the target analytes at various pH values revealed that THCCOOH was stable at pH 5.0. At higher pH values, its concentration slightly decreased with time, and about 69% of the initial THCCOOH concentration was still present at pH 8.0 on day 5. THCCOOglu concentrations rapidly decreased with increasing pH value. For example, only 72% of the initial THCCOOglu concentration could be detected at pH 5.0 on day 1. Degradation of the glucuronide resulted in formation of THCCOOH, which was observed even at pH 5.0. In light of the present findings, advanced forensic interpretations based on the presence of THCCOOH or the pattern of THCCOOH and THCCOOglu in stored urine samples seems questionable.
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Causes and impact of specimen rejection in a clinical chemistry laboratory.
Cao, Liyun; Chen, Meng; Phipps, Ron A; Del Guidice, Robert E; Handy, Beverly C; Wagar, Elizabeth A; Meng, Qing H
2016-07-01
Pre-analytical errors necessitate specimen rejection and negatively affect patient safety. Our purpose was to investigate the factors leading to specimen rejection and its impact. Specimen rejections in a clinical chemistry laboratory during a 1-year period were reviewed retrospectively and analyzed for frequency, cause, circumstances, and impact. Of the 837,862 specimens received, 2178 (0.26%) were rejected. The most common reasons for specimen rejection were contamination (n=764, 35.1%), inappropriate collection container/tube (n=330, 15.2%), quantity not sufficient (QNS) (n=329, 15.1%), labeling errors (n=321, 14.7%), hemolyzed specimen (n=205, 9.4%), and clotted specimen (n=203, 9.3%). The analytes most often affected were glucose (n=192, 8.8%); calcium (n=152, 7.0%), magnesium (n=148, 6.8%), potassium (n=137, 6.3%), creatinine (n=100, 4.6%), and blood urea nitrogen (n=97, 4.4%). Outpatient service and blood draw by phlebotomists were associated with low rejection rates (536/493,501 or 0.11% and 368/586,503 or 0.06%, respectively). Recollection due to specimen rejection increased the turnaround time by an average of 108min. The total cost for the recollection was around $43,210 USD with an average cost around $21.9 USD. The factors associated with rejection are remediable by improved training and quality assurance measures. Policies and procedures specific to specimen collection, transportation, and preparation should be strictly followed. Copyright © 2016 Elsevier B.V. All rights reserved.
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Laboratory Medicine Best Practice Guideline: Vitamins A, E and the Carotenoids in Blood
Greaves, Ronda F; Woollard, Gerald A; Hoad, Kirsten E; Walmsley, Trevor A; Johnson, Lambro A; Briscoe, Scott; Koetsier, Sabrina; Harrower, Tamantha; Gill, Janice P
2014-01-01
Despite apparent method similarities between laboratories there appear to be confounding factors inhibiting uniform reporting and standardisation of vitamin assays. The Australasian Association of Clinical Biochemists (AACB) Vitamins Working Party, in conjunction with The Royal College of Pathologists of Australasia Quality Assurance Programs, has formulated a guideline to improve performance, reproducibility and accuracy of fat-soluble vitamin results. The aim of the guideline is to identify critical pre-analytical, analytical and post-analytical components of the analysis of vitamins A, E and carotenoids in blood to promote best practice and harmonisation. This best practice guideline has been developed with reference to the Centers for Disease Control and Prevention (CDC) “Laboratory Medicine Best Practices: Developing an Evidence-Based Review and Evaluation Process”. The CDC document cites an evaluation framework for generating best practice recommendations that are specific to laboratory medicine. These 50 recommendations proposed herein, were generated from a comprehensive literature search and the extensive combined experience of the AACB Vitamins Working Party members. They were formulated based on comparison between an impact assessment rating and strength of evidence and were classified as either: (1) strongly recommend, (2) recommend, (3) no recommendation for or against, or (4) recommend against. These best practice recommendations represent the consensus views, in association with peer reviewed evidence of the AACB Vitamins Working Party, towards best practice for the collection, analysis and interpretation of vitamins A, E and carotenoids in blood. PMID:25210208
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Baraniskin, Alexander; Van Laethem, Jean-Luc; Wyrwicz, Lucjan; Guller, Ulrich; Wasan, Harpreet S; Matysiak-Budnik, Tamara; Gruenberger, Thomas; Ducreux, Michel; Carneiro, Fatima; Van Cutsem, Eric; Seufferlein, Thomas; Schmiegel, Wolff
2017-11-01
In the epoch of precision medicine and personalised oncology, which aims to deliver the right treatment to the right patient, molecular genetic biomarkers are a topic of growing interest. The aim of this expert discussion and position paper is to review the current status of various molecular tests for gastrointestinal (GI) cancers and especially considering their significance for the clinical routine use. Opinion leaders and experts from diverse nationalities selected on scientific merit were asked to answer to a prepared set of questions about the current status of molecular diagnostics in different GI cancers. All answers were then discussed during a plenary session and reported here in providing a well-balanced reflection of both clinical expertise and updated evidence-based medicine. Preselected molecular genetic biomarkers that are described and disputed in the current medical literature in different GI cancers were debated, and recommendations for clinical routine practice were made whenever possible. Furthermore, the preanalytical variations were commented and proposals for quality controls of biospecimens were made. The current article summarises the recommendations of the expert committee regarding prognostic and predictive molecular genetic biomarkers in different entities of GI cancers. The briefly and comprehensively formulated guidelines should assist clinicians in the process of decision making in daily clinical practice. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Sturgeon, Catharine; Hill, Robert; Hortin, Glen L; Thompson, Douglas
2010-01-01
There is increasing pressure to provide cost-effective healthcare based on “best practice.” Consequently, new biomarkers are only likely to be introduced into routine clinical biochemistry departments if they are supported by a strong evidence base and if the results will improve patient management and outcome. This requires convincing evidence of the benefits of introducing the new test, ideally reflected in fewer hospital admissions, fewer additional investigations and/or fewer clinic visits. Carefully designed audit and cost-benefit studies in relevant patient groups must demonstrate that introducing the biomarker delivers an improved and more effective clinical pathway. From the laboratory perspective, pre-analytical requirements must be thoroughly investigated at an early stage. Good stability of the biomarker in relevant physiological matrices is essential to avoid the need for special processing. Absence of specific timing requirements for sampling and knowledge of the effect of medications that might be used to treat the patients in whom the biomarker will be measured is also highly desirable. Analytically, automation is essential in modern high-throughput clinical laboratories. Assays must therefore be robust, fulfilling standard requirements for linearity on dilution, precision and reproducibility, both within- and between-run. Provision of measurements by a limited number of specialized reference laboratories may be most appropriate, especially when a new biomarker is first introduced into routine practice. PMID:21137030
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Neo, Shu Hui; Chung, Ka Yan; Quek, Jia Min; Too, Heng-Phon
2017-11-30
The preservation of nucleic acids from clinical samples is critical to facilitate accurate molecular diagnosis. The use of a paper matrix, Flinders Technology Associates (FTA) Elute cards, to archive DNA and viral RNA is well-documented. However, the feasibility of FTA Elute cards for archiving serum and serum exosomal microRNAs (miRNAs) remains unclear. Here, we performed a comprehensive evaluation of FTA Elute cards for miRNA storage and recovery in different pre-analytical conditions. The recovery of serum miRNA dry-spotted on FTA Elute cards by direct elution with water at high temperature was poor. However, serum miRNAs dry-spotted on the cards were isolated with about 40% yield when using QIAzol lysis reagent and recovery was improved remarkably (>80%) upon extraction from cards pre-treated with trehalose. miRNAs stored on the cards remained stable at room temperature and can be kept for prolonged periods. Furthermore, miRNAs could be similarly recovered from serum exosomes dry-spotted on the cards. Importantly, when using sera from gastric cancer (GC) patients, the miRNAs were efficiently recovered from trehalose pre-treated cards without affecting their representation. Collectively, we have demonstrated the potential of FTA Elute cards to archive serum and serum exosomal miRNAs, making it useful for biomarker discovery and diagnostics.
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Salivary cortisol in ambulatory assessment--some dos, some don'ts, and some open questions.
Kudielka, Brigitte M; Gierens, Andrea; Hellhammer, Dirk H; Wüst, Stefan; Schlotz, Wolff
2012-05-01
The impact of stress on health and disease is an important research topic in psychosomatic medicine. Because research on hypothalamic-pituitary-adrenal (HPA) axis regulation under controlled laboratory studies lacks ecological validity, it needs to be complemented by a research program that includes momentary ambulatory assessment. The measurement of salivary cortisol offers the possibility to trace the free steroid hormone concentrations in ambulant settings. Therefore, in this article, we first discuss the role of salivary cortisol in ambulatory monitoring. We start with a brief description of HPA axis regulation, and we then consider cortisol assessments in other organic materials, followed by a presentation of common salivary markers of HPA axis regulation suitable for ambulatory assessment. We further provide an overview on assessment designs and sources of variability within and between subjects (intervening variables), acknowledge the issue of (non)compliance, and address statistical aspects. We further give an overview of associations with psychosocial and health-related variables relevant for ambulatory assessment. Finally, we deal with preanalytical aspects of laboratory salivary cortisol analysis. The relative simplicity of salivary cortisol assessment protocols may lead to an overoptimistic view of the robustness of this method. We thus discuss several important issues related to the collection and storage of saliva samples and present empirical data on the stability of salivary cortisol measurements over time.
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Recent advances and opportunities in proteomic analyses of tumour heterogeneity.
Bateman, Nicholas W; Conrads, Thomas P
2018-04-01
Solid tumour malignancies comprise a highly variable admixture of tumour and non-tumour cellular populations, forming a complex cellular ecosystem and tumour microenvironment. This tumour heterogeneity is not incidental, and is known to correlate with poor patient prognosis for many cancer types. Indeed, non-malignant cell populations, such as vascular endothelial and immune cells, are known to play key roles supporting and, in some cases, driving aggressive tumour biology, and represent targets of emerging therapeutics, such as antiangiogenesis and immune checkpoint inhibitors. The biochemical interplay between these cellular populations and how they contribute to molecular tumour heterogeneity remains enigmatic, particularly from the perspective of the tumour proteome. This review focuses on recent advances in proteomic methods, namely imaging mass spectrometry, single-cell proteomic techniques, and preanalytical sample processing, that are uniquely positioned to enable detailed analysis of discrete cellular populations within tumours to improve our understanding of tumour proteomic heterogeneity. This review further emphasizes the opportunity afforded by the application of these techniques to the analysis of tumour heterogeneity in formalin-fixed paraffin-embedded archival tumour tissues, as these represent an invaluable resource for retrospective analyses that is now routinely accessible, owing to recent technological and methodological advances in tumour tissue proteomics. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Update on Modern Management of Pheochromocytoma and Paraganglioma.
Lenders, Jacques W M; Eisenhofer, Graeme
2017-06-01
Despite all technical progress in modern diagnostic methods and treatment modalities of pheochromocytoma/paraganglioma, early consideration of the presence of these tumors remains the pivotal link towards the best possible outcome for patients. A timely diagnosis and proper treatment can prevent the wide variety of potentially catastrophic cardiovascular complications. Modern biochemical testing should include tests that offer the best available diagnostic performance, measurements of metanephrines and 3-methoxytyramine in plasma or urine. To minimize false-positive test results particular attention should be paid to pre-analytical sampling conditions. In addition to anatomical imaging by computed tomography (CT) or magnetic resonance imaging, new promising functional imaging modalities of photon emission tomography/CT using with somatostatin analogues such as ⁶⁸Ga-DOTATATE (⁶⁸Ga-labeled DOTA(0)-Tyr(3)-octreotide) will probably replace ¹²³I-MIBG (iodine-123-metaiodobenzylguanidine) in the near future. As nearly half of all pheochromocytoma patients harbor a mutation in one of the 14 tumor susceptibility genes, genetic testing and counseling should at least be considered in all patients with a proven tumor. Post-surgical annual follow-up of patients by measurements of plasma or urinary metanephrines should last for at least 10 years for timely detection of recurrent or metastatic disease. Patients with a high risk for recurrence or metastatic disease (paraganglioma, young age, multiple or large tumors, genetic background) should be followed up lifelong. Copyright © 2017 Korean Endocrine Society.
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NASA Astrophysics Data System (ADS)
Bauer, Daniel R.; Stevens, Benjamin; Taft, Jefferson; Chafin, David; Petre, Vinnie; Theiss, Abbey P.; Otter, Michael
2014-03-01
Recently, it has been demonstrated that the preservation of cancer biomarkers, such as phosphorylated protein epitopes, in formalin-fixed paraffin-embedded tissue is highly dependent on the localized concentration of the crosslinking agent. This study details a real-time diffusion monitoring system based on the acoustic time-of-flight (TOF) between pairs of 4 MHz focused transducers. Diffusion affects TOF because of the distinct acoustic velocities of formalin and interstitial fluid. Tissue is placed between the transducers and vertically translated to obtain TOF values at multiple locations with a spatial resolution of approximately 1 mm. Imaging is repeated for several hours until osmotic equilibrium is reached. A post-processing technique, analogous to digital acoustic interferometry, enables detection of subnanosecond TOF differences. Reference subtraction is used to compensate for environmental effects. Diffusion measurements with TOF monitoring ex vivo human tonsil tissue are well-correlated with a single exponential curve (R2>0.98) with a magnitude of up to 50 ns, depending on the tissue size (2-6 mm). The average exponential decay constant of 2 and 6 mm diameter samples are 20 and 315 minutes, respectively, although times varied significantly throughout the tissue (σmax=174 min). This technique can precisely monitor diffusion progression and could be used to mitigate effects from tissue heterogeneity and intersample variability, enabling improved preservation of cancer biomarkers distinctly sensitive to degradation during preanalytical tissue processing.
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Armbruster, David A; Overcash, David R; Reyes, Jaime
2014-01-01
The era of automation arrived with the introduction of the AutoAnalyzer using continuous flow analysis and the Robot Chemist that automated the traditional manual analytical steps. Successive generations of stand-alone analysers increased analytical speed, offered the ability to test high volumes of patient specimens, and provided large assay menus. A dichotomy developed, with a group of analysers devoted to performing routine clinical chemistry tests and another group dedicated to performing immunoassays using a variety of methodologies. Development of integrated systems greatly improved the analytical phase of clinical laboratory testing and further automation was developed for pre-analytical procedures, such as sample identification, sorting, and centrifugation, and post-analytical procedures, such as specimen storage and archiving. All phases of testing were ultimately combined in total laboratory automation (TLA) through which all modules involved are physically linked by some kind of track system, moving samples through the process from beginning-to-end. A newer and very powerful, analytical methodology is liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). LC-MS/MS has been automated but a future automation challenge will be to incorporate LC-MS/MS into TLA configurations. Another important facet of automation is informatics, including middleware, which interfaces the analyser software to a laboratory information systems (LIS) and/or hospital information systems (HIS). This software includes control of the overall operation of a TLA configuration and combines analytical results with patient demographic information to provide additional clinically useful information. This review describes automation relevant to clinical chemistry, but it must be recognised that automation applies to other specialties in the laboratory, e.g. haematology, urinalysis, microbiology. It is a given that automation will continue to evolve in the clinical laboratory, limited only by the imagination and ingenuity of laboratory scientists. PMID:25336760
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Armbruster, David A; Overcash, David R; Reyes, Jaime
2014-08-01
The era of automation arrived with the introduction of the AutoAnalyzer using continuous flow analysis and the Robot Chemist that automated the traditional manual analytical steps. Successive generations of stand-alone analysers increased analytical speed, offered the ability to test high volumes of patient specimens, and provided large assay menus. A dichotomy developed, with a group of analysers devoted to performing routine clinical chemistry tests and another group dedicated to performing immunoassays using a variety of methodologies. Development of integrated systems greatly improved the analytical phase of clinical laboratory testing and further automation was developed for pre-analytical procedures, such as sample identification, sorting, and centrifugation, and post-analytical procedures, such as specimen storage and archiving. All phases of testing were ultimately combined in total laboratory automation (TLA) through which all modules involved are physically linked by some kind of track system, moving samples through the process from beginning-to-end. A newer and very powerful, analytical methodology is liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). LC-MS/MS has been automated but a future automation challenge will be to incorporate LC-MS/MS into TLA configurations. Another important facet of automation is informatics, including middleware, which interfaces the analyser software to a laboratory information systems (LIS) and/or hospital information systems (HIS). This software includes control of the overall operation of a TLA configuration and combines analytical results with patient demographic information to provide additional clinically useful information. This review describes automation relevant to clinical chemistry, but it must be recognised that automation applies to other specialties in the laboratory, e.g. haematology, urinalysis, microbiology. It is a given that automation will continue to evolve in the clinical laboratory, limited only by the imagination and ingenuity of laboratory scientists.
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Comparison of three noninvasive methods for hemoglobin screening of blood donors.
Ardin, Sergey; Störmer, Melanie; Radojska, Stela; Oustianskaia, Larissa; Hahn, Moritz; Gathof, Birgit S
2015-02-01
To prevent phlebotomy of anemic individuals and to ensure hemoglobin (Hb) content of the blood units, Hb screening of blood donors before donation is essential. Hb values are mostly evaluated by measurement of capillary blood obtained from fingerstick. Rapid noninvasive methods have recently become available and may be preferred by donors and staff. The aim of this study was to evaluate for the first time all different noninvasive methods for Hb screening. Blood donors were screened for Hb levels in three different trials using three different noninvasive methods (Haemospect [MBR Optical Systems GmbH & Co. KG], NBM 200 [LMB Technology GmbH], Pronto-7 [Masimo Europe Ltd]) in comparison to the established fingerstick method (CompoLab Hb [Fresenius Kabi GmbH]) and to levels obtained from venous samples on a cell counter (Sysmex [Sysmex Europe GmbH]) as reference. The usability of the noninvasive methods was assessed with an especially developed survey. Technical failures occurred by using the Pronto-7 due to nail polish, skin color, or ambient light. The NBM 200 also showed a high sensitivity to ambient light and noticeably lower Hb levels for women than obtained from the Sysmex. The statistical analysis showed the following bias and standard deviation of differences of all methods in comparison to the venous results: Haemospect, -0.22 ± 1.24; NBM, 200 -0.12 ± 1.14; Pronto-7, -0.50 ± 0.99; and CompoLab Hb, -0.53 ± 0.81. Noninvasive Hb tests represent an attractive alternative by eliminating pain and reducing risks of blood contamination. The main problem for generating reliable results seems to be preanalytical variability in sampling. Despite the sensitivity to environmental stress, all methods are suitable for Hb measurement. © 2014 AABB.
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The Effect of Holder Pasteurization on Activin A Levels in Human Milk.
Peila, Chiara; Coscia, Alessandra; Bertino, Enrico; Li Volti, Giovanni; Galvano, Fabio; Barbagallo, Ignazio; Visser, Gerard H A; Gazzolo, Diego
2016-11-01
There is evidence that mother's own milk is the best nutrient in terms of multiorgan protection and infection prevention. However, when maternal milk is scarce, the solution can be represented by donor milk (DM), which requires specific storage procedures such as Holder Pasteurization (HoP). HoP is not free from side effects since it is widely known that it causes qualitative/quantitative changes in milk composition, particularly in the protein content. Therefore, the aim of this study is to investigate the effects of HoP on Activin A, a neurobiomarker known to play an important role in the development and protection of the central nervous system. In 24 mothers who delivered preterm (n = 12) and term (n = 12) healthy newborns, we conducted a pretest/test study where the milk donors acted as their own controls. Each sample was divided into two parts: the first was frozen at -80°C (Group 1); the second was Holder-pasteurized before freezing at -80°C (Group 2). Activin A was quantified using an ELISA test. Activin A was detected in all samples. There were no significant differences (p > 0.05) between the two groups, also when the analysis was stratified for gestational age at delivery and milk maturation degree (p > 0.05, for both). The present findings on the absence of any side effects of HoP on the milk concentration of Activin A offer additional support to the efficacy of HoP in DM storage. Our data open up to further investigations on neurobiomarkers' assessment in human milk and their preanalytical stability according to storage procedures.
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Kocijancic, Marija; Cargonja, Jelena; Delic-Knezevic, Alma
2014-01-01
Preanalytical variables account for most of laboratory errors. There is a wide range of factors that affect the reliability of laboratory report. Most convenient sample type for routine laboratory analysis is serum. BD Vacutainer(®) Rapid Serum Tube (RST) (Becton, Dickinson and Company, Franklin Lakes, NJ, USA) blood collection tube provides rapid clotting time allowing fast serum separation. Our aim was to evaluate the comparability of routine chemistry parameters in BD Vacutainer(®) RST blood collection tube in reference with the BD Vacutainer(®) Serum Separating Tubes II Advance Tube (SST) (Becton, Dickinson and Company, Franklin Lakes, NJ, USA). Blood specimens were collected from 90 participants for evaluation on its results, clotting time and stability study of six routine biochemistry parameters: glucose (Glu), aspartate aminotransferase (AST), alanine aminotransferase (ALT), calcium (Ca), lactate dehidrogenase (LD) and potassium (K) measured with Olympus AU2700 analyzer (Beckman Coulter, Tokyo, Japan). The significance of the differences between samples was assessed by paired t-test or Wilcoxon Matched-Pairs Rank test after checking for normality. Clotting process was significantly shorter in the RSTs compared to SSTs (2.49 min vs. 19.47 min, respectively; P < 0.001). There was a statistically significant difference between the RST and SST II tubes for glucose, calcium and LD (P < 0.001). Differences for glucose and LD were also clinically significant. Analyte stability studies showed that all analytes were stable for 24 h at 4 °C. Most results (except LD and glucose) from RST are comparable with those from SST. In addition, RST tube provides shorter clotting time.
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Hematological reference values of healthy Malaysian population.
Roshan, T M; Rosline, H; Ahmed, S A; Rapiaah, M; Wan Zaidah, A; Khattak, M N
2009-10-01
Health and disease can only be distinguished by accurate and reliable reference values of a particular laboratory test. It is now a proven fact that there is considerable variation in hematology reference intervals depending on the demographic and preanalytical variables. There are evidences that values provided by manufacturers do not have appropriate application for all populations. Moreover, reference ranges provided by different laboratory manuals and books also do not solve this problem. We are presenting here normal reference ranges of Malaysian population. These values were determined by using Sysmex XE-2100 and ACL 9000 hematology and coagulation analyzers. Results from this study showed that there were considerable differences in the reference values from manufacturers, western population or laboratory manuals compared with those from the local population.
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Bühnemann, Claudia; Li, Simon; Yu, Haiyue; Branford White, Harriet; Schäfer, Karl L; Llombart-Bosch, Antonio; Machado, Isidro; Picci, Piero; Hogendoorn, Pancras C W; Athanasou, Nicholas A; Noble, J Alison; Hassan, A Bassim
2014-01-01
Driven by genomic somatic variation, tumour tissues are typically heterogeneous, yet unbiased quantitative methods are rarely used to analyse heterogeneity at the protein level. Motivated by this problem, we developed automated image segmentation of images of multiple biomarkers in Ewing sarcoma to generate distributions of biomarkers between and within tumour cells. We further integrate high dimensional data with patient clinical outcomes utilising random survival forest (RSF) machine learning. Using material from cohorts of genetically diagnosed Ewing sarcoma with EWSR1 chromosomal translocations, confocal images of tissue microarrays were segmented with level sets and watershed algorithms. Each cell nucleus and cytoplasm were identified in relation to DAPI and CD99, respectively, and protein biomarkers (e.g. Ki67, pS6, Foxo3a, EGR1, MAPK) localised relative to nuclear and cytoplasmic regions of each cell in order to generate image feature distributions. The image distribution features were analysed with RSF in relation to known overall patient survival from three separate cohorts (185 informative cases). Variation in pre-analytical processing resulted in elimination of a high number of non-informative images that had poor DAPI localisation or biomarker preservation (67 cases, 36%). The distribution of image features for biomarkers in the remaining high quality material (118 cases, 104 features per case) were analysed by RSF with feature selection, and performance assessed using internal cross-validation, rather than a separate validation cohort. A prognostic classifier for Ewing sarcoma with low cross-validation error rates (0.36) was comprised of multiple features, including the Ki67 proliferative marker and a sub-population of cells with low cytoplasmic/nuclear ratio of CD99. Through elimination of bias, the evaluation of high-dimensionality biomarker distribution within cell populations of a tumour using random forest analysis in quality controlled tumour material could be achieved. Such an automated and integrated methodology has potential application in the identification of prognostic classifiers based on tumour cell heterogeneity.
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Brott, David A; Furlong, Stephen T; Adler, Scott H; Hainer, James W; Arani, Ramin B; Pinches, Mark; Rossing, Peter; Chaturvedi, Nish
2015-01-01
Identifying the potential for drug-induced kidney injury is essential for the successful research and development of new drugs. Newer and more sensitive preclinical drug-induced kidney injury biomarkers are now qualified for use in rat toxicology studies, but biomarkers for clinical studies are still undergoing qualification. The current studies investigated biomarkers in healthy volunteer (HV) urine samples with and without the addition of stabilizer as well as in urine from patients with normoalbuminuric diabetes mellitus (P-DM). Urine samples from 20 male HV with stabilizer, 69 male HV without stabilizer, and 95 male DM without stabilizer (39 type 1 and 56 type 2) were analyzed for the following bio-markers using multiplex assays: α-1-microglobulin (A1M), β-2-microglobulin, calbindin, clusterin, connective tissue growth factor (CTGF), creatinine, cystatin-C, glutathione S-transferase α (GSTα), kidney injury marker-1 (KIM-1), microalbumin, neutrophil gelatinase-associated lipocalin, osteopontin, Tamm-Horsfall urinary glycoprotein (THP), tissue inhibitor of metalloproteinase 1, trefoil factor 3 (TFF3), and vascular endothelial growth factor. CTGF and GSTα assays on nonstabilized urine were deemed nonoptimal (>50% of values below assay lower limits of quantification). "Expected values" were determined for HV with stabilizer, HV without stabilizer, and P-DM without stabilizer. There was a statistically significant difference between HV with stabilizer compared to HV without stabilizer for A1M, CTGF, GSTα, and THP. DM urine samples differed from HV (without stabilizer) for A1M CTGF, GSTα, KIM-1, microalbumin, osteopontin, and TFF3. A1M also correctly identified HV and DM with an accuracy of 89.0%. These studies: 1) determined that nonstabilized urine can be used for assays under qualification; and 2) documented that A1M, CTGF, GSTα, KIM-1, microalbumin, osteopontin, and TFF3 were significantly increased in urine from P-DM. In addition, the 89.0% accuracy of A1M in distinguishing P-DM from HV may allow this biomarker to be used to monitor efficacy of potential renal protective agents.
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Antimicrobial Stewardship: How the Microbiology Laboratory Can Right the Ship
Schwartz, David N.; Weinstein, Robert A.
2016-01-01
SUMMARY Antimicrobial stewardship is a bundle of integrated interventions employed to optimize the use of antimicrobials in health care settings. While infectious-disease-trained physicians, with clinical pharmacists, are considered the main leaders of antimicrobial stewardship programs, clinical microbiologists can play a key role in these programs. This review is intended to provide a comprehensive discussion of the different components of antimicrobial stewardship in which microbiology laboratories and clinical microbiologists can make significant contributions, including cumulative antimicrobial susceptibility reports, enhanced culture and susceptibility reports, guidance in the preanalytic phase, rapid diagnostic test availability, provider education, and alert and surveillance systems. In reviewing this material, we emphasize how the rapid, and especially the recent, evolution of clinical microbiology has reinforced the importance of clinical microbiologists' collaboration with antimicrobial stewardship programs. PMID:27974411
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Commercialisation of Biomarker Tests for Mental Illnesses: Advances and Obstacles.
Chan, Man K; Cooper, Jason D; Bahn, Sabine
2015-12-01
Substantial strides have been made in the field of biomarker research for mental illnesses over the past few decades. However, no US FDA-cleared blood-based biomarker tests have been translated into routine clinical practice. Here, we review the challenges associated with commercialisation of research findings and discuss how these challenges can impede scientific impact and progress. Overall evidence indicates that a lack of research funding and poor reproducibility of findings were the most important obstacles to commercialization of biomarker tests. Fraud, pre-analytical and analytical limitations, and inappropriate statistical analysis are major contributors to poor reproducibility. Increasingly, these issues are acknowledged and actions are being taken to improve data validity, raising the hope that robust biomarker tests will become available in the foreseeable future. Copyright © 2015 Elsevier Ltd. All rights reserved.
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[Improving blood safety: errors management in transfusion medicine].
Bujandrić, Nevenka; Grujić, Jasmina; Krga-Milanović, Mirjana
2014-01-01
The concept of blood safety includes the entire transfusion chain starting with the collection of blood from the blood donor, and ending with blood transfusion to the patient. The concept involves quality management system as the systematic monitoring of adverse reactions and incidents regarding the blood donor or patient. Monitoring of near-miss errors show the critical points in the working process and increase transfusion safety. The aim of the study was to present the analysis results of adverse and unexpected events in transfusion practice with a potential risk to the health of blood donors and patients. One-year retrospective study was based on the collection, analysis and interpretation of written reports on medical errors in the Blood Transfusion Institute of Vojvodina. Errors were distributed according to the type, frequency and part of the working process where they occurred. Possible causes and corrective actions were described for each error. The study showed that there were not errors with potential health consequences for the blood donor/patient. Errors with potentially damaging consequences for patients were detected throughout the entire transfusion chain. Most of the errors were identified in the preanalytical phase. The human factor was responsible for the largest number of errors. Error reporting system has an important role in the error management and the reduction of transfusion-related risk of adverse events and incidents. The ongoing analysis reveals the strengths and weaknesses of the entire process and indicates the necessary changes. Errors in transfusion medicine can be avoided in a large percentage and prevention is cost-effective, systematic and applicable.
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Practical, transparent prospective risk analysis for the clinical laboratory.
Janssens, Pim Mw
2014-11-01
Prospective risk analysis (PRA) is an essential element in quality assurance for clinical laboratories. Practical approaches to conducting PRA in laboratories, however, are scarce. On the basis of the classical Failure Mode and Effect Analysis method, an approach to PRA was developed for application to key laboratory processes. First, the separate, major steps of the process under investigation are identified. Scores are then given for the Probability (P) and Consequence (C) of predefined types of failures and the chances of Detecting (D) these failures. Based on the P and C scores (on a 10-point scale), an overall Risk score (R) is calculated. The scores for each process were recorded in a matrix table. Based on predetermined criteria for R and D, it was determined whether a more detailed analysis was required for potential failures and, ultimately, where risk-reducing measures were necessary, if any. As an illustration, this paper presents the results of the application of PRA to our pre-analytical and analytical activities. The highest R scores were obtained in the stat processes, the most common failure type in the collective process steps was 'delayed processing or analysis', the failure type with the highest mean R score was 'inappropriate analysis' and the failure type most frequently rated as suboptimal was 'identification error'. The PRA designed is a useful semi-objective tool to identify process steps with potential failures rated as risky. Its systematic design and convenient output in matrix tables makes it easy to perform, practical and transparent. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
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Booth, Ronald A; Ansari, Mohammed T; Tricco, Andrea C; Loit, Evelin; Weeks, Laura; Doucette, Steve; Skidmore, Becky; Hoch, Jeffrey S; Tsouros, Sophia; Sears, Margaret; Sy, Richmond; Karsh, Jacob; Mani, Suja; Galipeau, James; Yurkiewich, Alexander; Daniel, Raymond; Tsertsvadze, Alexander; Yazdi, Fatemeh
2010-12-01
To examine whether pretreatment determination of thiopurine methyltransferase (TPMT) enzymatic activity (phenotyping) or TPMT genotype, to guide thiopurine therapy in chronic autoimmune disease patients, reduces treatment harms. Other objectives included assessing: preanalytic, analytic, and postanalytic requirements for TPMT testing; diagnostic accuracy of TPMT genotyping versus phenotyping; association of thiopurine toxicity with TPMT genotypic or phenotypic status; and costs of testing, care, and treating drug-associated complications. MEDLINE®, EMBASE®, and Healthstar were searched from inception to May 2010; the Cochrane Library® to October 2009; and BIOSIS®, Genetics Abstracts, and EconLit™ to May 2009, for English language records. A reviewer screened records, and a second reviewer verified exclusions and subsequent selection of relevant studies. Studies in patients with leukemia and organ transplant were excluded. Additionally, laboratories that provide TPMT analytical services were surveyed to assess means of TPMT testing in practice. Where possible, risk of bias was assessed using standard criteria. Meta-analyses estimated diagnostic sensitivity, and specificity; and odds ratios of associations. 1790 titles or abstracts, and 538 full text records were screened. 114 observational studies and one RCT were included. Majority of studies were rated fair quality, except for diagnostic studies with 37 percent of studies rated poor. In general, there were few patients who were homozygous (or compound heterozygous) for TPMT variant alleles in the included studies limiting applicability. There is insufficient evidence examining effectiveness of pretesting in terms of reduction in clinical adverse events. Sufficient preanalytical data were available regarding preferred specimen collection, stability and storage conditions for TPMT testing. There was no clinically significant effect of age, gender, various coadministered drugs, or most morbidities (with the exception of renal failure and dialysis). TPMT phenotyping methods had coefficients of variation generally below 10 percent. TPMT genotyping reproducibility is generally between 95-100 percent. The sensitivity of genotyping to identify patients with low or intermediate TPMT enzymatic activity is imprecise, ranging from 70.70 to 82.10 percent (95 percent CI, lower bound range 37.90 to 54.00 percent; upper bound range 84.60 to 96.90 percent). Sensitivity of homozygous TPMT genotype to correctly identify patients with low to absent enzymatic activity was 87.10 percent (95 percent CI 44.30 to 98.30 percent). Genotyping specificity approached 100 percent. Leukopenia was significantly associated with low and intermediate enzymatic activity (low activity OR 80.00, 95 percent CI 11.5 to 559; and intermediate activity OR 2.96, 95 percent CI 1.18 to 7.42), and homozygous and heterozygous TPMT variant allele genotype (OR 18.60, 95 percent CI 4.12 to 83.60; and 4.62, 95 percent CI 2.34 to 9.16, respectively). In general, TPMT phenotyping costs less than genotyping, although estimates across studies are quite heterogeneous. There is insufficient direct evidence regarding the effectiveness of pretesting of TPMT status in patients with chronic autoimmune diseases. Indirect evidence confirms strong association of leukopenia with lower levels of TPMT activity and carrier genotype already established in the literature.
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Booth, Ronald A; Ansari, Mohammed T; Tricco, Andrea C; Loit, Evelin; Weeks, Laura; Doucette, Steve; Skidmore, Becky; Hoch, Jeffrey S; Tsouros, Sophia; Sears, Margaret; Sy, Richmond; Karsh, Jacob; Mani, Suja; Galipeau, James; Yurkiewich, Alexander; Daniel, Raymond; Tsertsvadze, Alexander; Yazdi, Fatemeh
2010-01-01
OBJECTIVES To examine whether pretreatment determination of thiopurine methyltransferase (TPMT) enzymatic activity (phenotyping) or TPMT genotype, to guide thiopurine therapy in chronic autoimmune disease patients, reduces treatment harms. Other objectives included assessing: preanalytic, analytic, and postanalytic requirements for TPMT testing; diagnostic accuracy of TPMT genotyping versus phenotyping; association of thiopurine toxicity with TPMT genotypic or phenotypic status; and costs of testing, care, and treating drug-associated complications. DATA SOURCES MEDLINE®, EMBASE®, and Healthstar were searched from inception to May 2010; the Cochrane Library® to October 2009; and BIOSIS®, Genetics Abstracts, and EconLit™ to May 2009, for English language records. REVIEW METHODS A reviewer screened records, and a second reviewer verified exclusions and subsequent selection of relevant studies. Studies in patients with leukemia and organ transplant were excluded. Additionally, laboratories that provide TPMT analytical services were surveyed to assess means of TPMT testing in practice. Where possible, risk of bias was assessed using standard criteria. Meta-analyses estimated diagnostic sensitivity, and specificity; and odds ratios of associations. RESULTS 1790 titles or abstracts, and 538 full text records were screened. 114 observational studies and one RCT were included. Majority of studies were rated fair quality, except for diagnostic studies with 37 percent of studies rated poor. In general, there were few patients who were homozygous (or compound heterozygous) for TPMT variant alleles in the included studies limiting applicability. There is insufficient evidence examining effectiveness of pretesting in terms of reduction in clinical adverse events. Sufficient preanalytical data were available regarding preferred specimen collection, stability and storage conditions for TPMT testing. There was no clinically significant effect of age, gender, various coadministered drugs, or most morbidities (with the exception of renal failure and dialysis). TPMT phenotyping methods had coefficients of variation generally below 10 percent. TPMT genotyping reproducibility is generally between 95-100 percent. The sensitivity of genotyping to identify patients with low or intermediate TPMT enzymatic activity is imprecise, ranging from 70.70 to 82.10 percent (95 percent CI, lower bound range 37.90 to 54.00 percent; upper bound range 84.60 to 96.90 percent). Sensitivity of homozygous TPMT genotype to correctly identify patients with low to absent enzymatic activity was 87.10 percent (95 percent CI 44.30 to 98.30 percent). Genotyping specificity approached 100 percent. Leukopenia was significantly associated with low and intermediate enzymatic activity (low activity OR 80.00, 95 percent CI 11.5 to 559; and intermediate activity OR 2.96, 95 percent CI 1.18 to 7.42), and homozygous and heterozygous TPMT variant allele genotype (OR 18.60, 95 percent CI 4.12 to 83.60; and 4.62, 95 percent CI 2.34 to 9.16, respectively). In general, TPMT phenotyping costs less than genotyping, although estimates across studies are quite heterogeneous. CONCLUSIONS There is insufficient direct evidence regarding the effectiveness of pretesting of TPMT status in patients with chronic autoimmune diseases. Indirect evidence confirms strong association of leukopenia with lower levels of TPMT activity and carrier genotype already established in the literature. PMID:23126559
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Kleine, Tilmann O; Nebe, C Thomas; Löwer, Christa; Lehmitz, Reinhard; Kruse, Rolf; Geilenkeuser, Wolf-Jochen; Dorn-Beineke, Alexandra
2009-08-01
Flow cytometry (FCM) is used with haematology analyzers (HAs) to count cells and differentiate leukocytes in cerebrospinal fluid (CSF). To evaluate the FCM techniques of HAs, 10 external DGKL trials with CSF controls were carried out in 2004 to 2008. Eight single platform HAs with and without CSF equipment were evaluated with living blood leukocytes and erythrocytes in CSF like DGKL controls: Coulter (LH750,755), Abbott CD3200, CD3500, CD3700, CD4000, Sapphire, ADVIA 120(R) CSF assay, and Sysmex XE-2100(R). Results were compared with visual counting of native cells in Fuchs-Rosenthal chamber, unstained, and absolute values of leukocyte differentiation, assayed by dual platform analysis with immune-FCM (FACSCalibur, CD45, CD14) and the chamber counts. Reference values X were compared with HA values Y by statistical evaluation with Passing/Bablock (P/B) linear regression analysis to reveal conformity of both methods. The HAs, studied, produced no valid results with DGKL CSF controls, because P/B regression revealed no conformity with the reference values due to:-blank problems with impedance analysis,-leukocyte loss with preanalytical erythrocyte lysis procedures, especially of monocytes,-inaccurate results with ADVIA cell sphering and cell differentiation with algorithms and enzyme activities (e.g., peroxidase). HA techniques have to be improved, e.g., using no erythrocyte lysis and CSF adequate techniques, to examine CSF samples precise and accurate. Copyright 2009 International Society for Advancement of Cytometry.
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Indirect methods for reference interval determination - review and recommendations.
Jones, Graham R D; Haeckel, Rainer; Loh, Tze Ping; Sikaris, Ken; Streichert, Thomas; Katayev, Alex; Barth, Julian H; Ozarda, Yesim
2018-04-19
Reference intervals are a vital part of the information supplied by clinical laboratories to support interpretation of numerical pathology results such as are produced in clinical chemistry and hematology laboratories. The traditional method for establishing reference intervals, known as the direct approach, is based on collecting samples from members of a preselected reference population, making the measurements and then determining the intervals. An alternative approach is to perform analysis of results generated as part of routine pathology testing and using appropriate statistical techniques to determine reference intervals. This is known as the indirect approach. This paper from a working group of the International Federation of Clinical Chemistry (IFCC) Committee on Reference Intervals and Decision Limits (C-RIDL) aims to summarize current thinking on indirect approaches to reference intervals. The indirect approach has some major potential advantages compared with direct methods. The processes are faster, cheaper and do not involve patient inconvenience, discomfort or the risks associated with generating new patient health information. Indirect methods also use the same preanalytical and analytical techniques used for patient management and can provide very large numbers for assessment. Limitations to the indirect methods include possible effects of diseased subpopulations on the derived interval. The IFCC C-RIDL aims to encourage the use of indirect methods to establish and verify reference intervals, to promote publication of such intervals with clear explanation of the process used and also to support the development of improved statistical techniques for these studies.
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Plasma biochemistry RIs and age effect in European Strigiformes.
Agusti Montolio, Susana; Cuenca Valera, Rafaela; Lavín González, Santiago; Cray, Carolyn; Molina López, Rafael; Ferron, Emmanuel Serrano; Francisco, Olga Nicolás; Marco Sánchez, Ignasi; Casas-Díaz, Encarna
2018-03-01
Blood biochemistry and hematology are essential in the laboratory diagnosis of disease. In Strigiformes, little information regarding reference values and influence of different preanalytic factors is available, while age is known to have an effect on some biochemistry analytes, especially in early life characterized by a rapid growth rate and increase in body mass. The objective of this study was to determine baseline data for 29 blood biochemistry variables in 5 species of Iberian Strigiformes assigned to different age classes. Healthy nocturnal birds living in wildlife health centers of Catalonia, Northeastern Spain were assigned to different age classes (chicks, juveniles, adults where possible and available) and their blood was collected and analyzed for different standard biochemistry variables. Species included Tawny owls, Little owls, Long-eared owls, Scop owls, and Barn owls. A total of 276 clinically healthy animals were sampled, including between 179 chicks, 52 juveniles, and 45 adults. The RIs of cholesterol, albumin, and osmolality were the only variables that did not show interspecific variability. Common trends between age class groups were observed in 4 species. Phosphorus and calcium concentrations and ALP activities decreased with increasing age, while concentrations of sodium and γ-globulins tended to increase in the Strigidae family. Differences were concentrated in chicks and no differences were observed between juveniles and adults in any variable. Our results demonstrate the importance of defining biochemical RIs specific for certain age classes. © 2018 American Society for Veterinary Clinical Pathology.
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Stability of pro-gastrin-releasing peptide in serum versus plasma.
Yoshimura, Toru; Fujita, Kenju; Kawakami, Satoshi; Takeda, Katsumichi; Chan, Sabrina; Beligere, Gangamani; Dowell, Barry
2008-01-01
Although serum assays for pro-gastrin-releasing peptide (ProGRP) assays have been commercially available in Japan for several years, the stability of ProGRP in serum and plasma has not been well documented. We investigated the stability of ProGRP in serum and plasma with fresh and stored (frozen) specimens, as well as the cause of the observed instability in serum. ProGRP concentrations in fresh serum were decreased by 6-28% after room temperature storage for 2 h and by 8-32% after 2-8 degrees C storage for 24 h. The average change in ProGRP concentrations in fresh plasma was within +/-10% of baseline for more than 4 h at room temperature and for more than 24 h at 2-8 degrees C. The incubation of a serine protease, thrombin (activated blood coagulation factor II), in a buffer solution containing ProGRP caused decreases in ProGRP concentrations. Following the addition of phenylmethylsulfonyl fluoride, a serine protease inhibitor, to serum, the serum stability for ProGRP was similar to that in plasma. ProGRP is significantly more stable in plasma than in serum. We speculate that thrombin in serum is one of the factors that inactivate ProGRP in serum by proteolysis of the ProGRP antigen. The use of plasma samples for ProGRP may improve the clinical reliability of this marker by minimizing preanalytical changes in ProGRP concentrations. (c) 2008 S. Karger AG, Basel.
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2012-04-06
Biochemical genetic testing and newborn screening are essential laboratory services for the screening, detection, diagnosis, and monitoring of inborn errors of metabolism or inherited metabolic disorders. Under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) regulations, laboratory testing is categorized on the basis of the level of testing complexity as either waived (i.e., from routine regulatory oversight) or nonwaived testing (which includes tests of moderate and high complexity). Laboratories that perform biochemical genetic testing are required by CLIA regulations to meet the general quality systems requirements for nonwaived testing and the personnel requirements for high-complexity testing. Laboratories that perform public health newborn screening are subject to the same CLIA regulations and applicable state requirements. As the number of inherited metabolic diseases that are included in state-based newborn screening programs continues to increase, ensuring the quality of performance and delivery of testing services remains a continuous challenge not only for public health laboratories and other newborn screening facilities but also for biochemical genetic testing laboratories. To help ensure the quality of laboratory testing, CDC collaborated with the Centers for Medicare & Medicaid Services, the Food and Drug Administration, the Health Resources and Services Administration, and the National Institutes of Health to develop guidelines for laboratories to meet CLIA requirements and apply additional quality assurance measures for these areas of genetic testing. This report provides recommendations for good laboratory practices that were developed based on recommendations from the Clinical Laboratory Improvement Advisory Committee, with additional input from the Secretary's Advisory Committee on Genetics, Health, and Society; the Secretary's Advisory Committee on Heritable Disorders in Newborns and Children; and representatives of newborn screening laboratories. The recommended practices address the benefits of using a quality management system approach, factors to consider before introducing new tests, establishment and verification of test performance specifications, the total laboratory testing process (which consists of the preanalytic, analytic, and postanalytic phases), confidentiality of patient information and test results, and personnel qualifications and responsibilities for laboratory testing for inherited metabolic diseases. These recommendations are intended for laboratories that perform biochemical genetic testing to improve the quality of laboratory services and for newborn screening laboratories to ensure the quality of laboratory practices for inherited metabolic disorders. These recommendations also are intended as a resource for medical and public health professionals who evaluate laboratory practices, for users of laboratory services to facilitate their collaboration with newborn screening systems and use of biochemical genetic tests, and for standard-setting organizations and professional societies in developing future laboratory quality standards and practice recommendations. This report complements Good Laboratory Practices for Molecular Genetic Testing for Heritable Diseases and Conditions (CDC. Good laboratory practices for molecular genetic testing for heritable diseases and conditions. MMWR 2009;58 [No. RR-6]) to provide guidance for ensuring and improving the quality of genetic laboratory services and public health outcomes. Future recommendations for additional areas of genetic testing will be considered on the basis of continued monitoring and evaluation of laboratory practices, technology advancements, and the development of laboratory standards and guidelines.
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Quality-control design for surface-water sampling in the National Water-Quality Network
Riskin, Melissa L.; Reutter, David C.; Martin, Jeffrey D.; Mueller, David K.
2018-04-10
The data-quality objectives for samples collected at surface-water sites in the National Water-Quality Network include estimating the extent to which contamination, matrix effects, and measurement variability affect interpretation of environmental conditions. Quality-control samples provide insight into how well the samples collected at surface-water sites represent the true environmental conditions. Quality-control samples used in this program include field blanks, replicates, and field matrix spikes. This report describes the design for collection of these quality-control samples and the data management needed to properly identify these samples in the U.S. Geological Survey’s national database.
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[Hyperkalemia - what the general practitioner must know].
Schnyder, Aurelia; Hüsler, Carina; Binet, Isabelle
2015-03-25
Hyperkalemia can be a challenge for the general practitioner as it can prove to be benign as well as life-threatening. From a diagnostic point of view, four possibilities have to be differenciated: a pre-analytical cause, potassium release through cell lysis, a potassium shift, a reduced renal excretion of potassium. The first differential diagnosis can often be carried out by a thorough medical history, in particular the medication intake. Also, the first clinical and laboratory investigations can take place at the general practitioner's clinic. If the hyperkalemia proves to be a true hyperkalemia or cannot be explained by poly-medication and known diseases of the patient, not yet identified renal, endocrine or cardiac diseases should be searched for. If a serious condition is identified as the cause of hyperkalemia the patient should be referred to a specialized clinic.
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Antimicrobial Stewardship: How the Microbiology Laboratory Can Right the Ship.
Morency-Potvin, Philippe; Schwartz, David N; Weinstein, Robert A
2017-01-01
Antimicrobial stewardship is a bundle of integrated interventions employed to optimize the use of antimicrobials in health care settings. While infectious-disease-trained physicians, with clinical pharmacists, are considered the main leaders of antimicrobial stewardship programs, clinical microbiologists can play a key role in these programs. This review is intended to provide a comprehensive discussion of the different components of antimicrobial stewardship in which microbiology laboratories and clinical microbiologists can make significant contributions, including cumulative antimicrobial susceptibility reports, enhanced culture and susceptibility reports, guidance in the preanalytic phase, rapid diagnostic test availability, provider education, and alert and surveillance systems. In reviewing this material, we emphasize how the rapid, and especially the recent, evolution of clinical microbiology has reinforced the importance of clinical microbiologists' collaboration with antimicrobial stewardship programs. Copyright © 2016 American Society for Microbiology.
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[ABOUT UNIFICATION OF LABORATORY CRITERIA OF DIFFERENTIATION OF BACTERIAL VAGINOSIS].
Mavzutov, A R; Tsvetkova, A V; Muretdinova, L A
2015-06-01
The article presents analysis of laboratory criteria and classifcations used to interpret results of laboratory analysis by technique of microscopy on bacterial vaginosis or dysbacteriosis of vagina. Their advantages and restrictions are demonstrated The unified criteria of evaluation are proposed concerning results of microscopy of mucosal discharge of vagina and corresponding classification. Thereafter, three degrees of bacterial vaginosis (dysbacteriosis of vagina) are differentiated: first degree--compensated dysbacteriosis of vagina, second degree--sub compensated dysbacteriosis of vagina and third degree--decompensated dysbacteriosis of vagina. The corresponding laboratory report of physician is formulated. The proposals are presented concerning development of common unified requirements to stages (pre-analytical, analytical, post-analytical) of laboratory diagnostic of bacterial vaginosis (dysbacteriosis of vagina) with purpose of their unambiguous understanding by clinicians and hence their decision making concerning necessity and tactics of management of patient.
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Degradation and Stabilization of Peptide Hormones in Human Blood Specimens
Yi, Jizu; Warunek, David; Craft, David
2015-01-01
Plasma hormone peptides, including GLP-1, GIP, Glucagon, and OXM, possess multiple physiological roles and potential therapeutic and diagnostic utility as biomarkers in the research of metabolic disorders. These peptides are subject to proteolytic degradation causing preanalytical variations. Stabilization for accurate quantitation of these active peptides in ex vivo blood specimens is essential for drug and biomarker development. We investigated the protease-driven instability of these peptides in conventional serum, plasma, anticoagulated whole blood, as well as whole blood and plasma stabilized with protease inhibitors. The peptide was monitored by both time-course Matrix-Assisted Laser Desorption Ionization Time-to-Flight Mass Spectrometry (MALDI –TOF MS) and Ab-based assay (ELISA or RIA). MS enabled the identification of proteolytic fragments. In non-stabilized blood samples, the results clearly indicated that dipeptidyl peptidase-IV (DPP-IV) removed the N-terminal two amino acid residues from GLP-1, GIP and OXM(1-37) and not-yet identified peptidase(s) cleave(s) the full-length OXM(1-37) and its fragments. DPP-IV also continued to remove two additional N-terminal residues of processed OXM(3–37) to yield OXM(5–37). Importantly, both DPP-IV and other peptidase(s) activities were inhibited efficiently by the protease inhibitors included in the BD P800* tube. There was preservation of GLP-1, GIP, OXM and glucagon in the P800 plasma samples with half-lives > 96, 96, 72, and 45 hours at room temperature (RT), respectively. In the BD P700* plasma samples, the stabilization of GLP-1 was also achieved with half-life > 96 hours at RT. The stabilization of these variable peptides increased their utility in drug and/or biomarker development. While stability results of GLP-1 obtained with Ab-based assay were consistent with those obtained by MS analysis, the Ab-based results of GIP, Glucagon, and OXM did not reflect the time-dependent degradations revealed by MS analysis. Therefore, we recommended characterizing the degradation of the peptide using the MS-based method when investigating the stability of a specific peptide. PMID:26222180
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Jones, Jeffery I.; Gardner, Michael S.; Schieltz, David M.; Parks, Bryan A.; Toth, Christopher A.; Rees, Jon C.; Andrews, Michael L.; Carter, Kayla; Lehtikoski, Antony K.; McWilliams, Lisa G.; Williamson, Yulanda M.; Bierbaum, Kevin P.; Pirkle, James L.; Barr, John R.
2018-01-01
Lipoproteins are complex molecular assemblies that are key participants in the intricate cascade of extracellular lipid metabolism with important consequences in the formation of atherosclerotic lesions and the development of cardiovascular disease. Multiplexed mass spectrometry (MS) techniques have substantially improved the ability to characterize the composition of lipoproteins. However, these advanced MS techniques are limited by traditional pre-analytical fractionation techniques that compromise the structural integrity of lipoprotein particles during separation from serum or plasma. In this work, we applied a highly effective and gentle hydrodynamic size based fractionation technique, asymmetric flow field-flow fractionation (AF4), and integrated it into a comprehensive tandem mass spectrometry based workflow that was used for the measurement of apolipoproteins (apos A-I, A-II, A-IV, B, C-I, C-II, C-III and E), free cholesterol (FC), cholesterol esters (CE), triglycerides (TG), and phospholipids (PL) (phosphatidylcholine (PC), sphingomyelin (SM), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and lysophosphatidylcholine (LPC)). Hydrodynamic size in each of 40 size fractions separated by AF4 was measured by dynamic light scattering. Measuring all major lipids and apolipoproteins in each size fraction and in the whole serum, using total of 0.1 ml, allowed the volumetric calculation of lipoprotein particle numbers and expression of composition in molar analyte per particle number ratios. Measurements in 110 serum samples showed substantive differences between size fractions of HDL and LDL. Lipoprotein composition within size fractions was expressed in molar ratios of analytes (A-I/A-II, C-II/C-I, C-II/C-III. E/C-III, FC/PL, SM/PL, PE/PL, and PI/PL), showing differences in sample categories with combinations of normal and high levels of Total-C and/or Total-TG. The agreement with previous studies indirectly validates the AF4-LC-MS/MS approach and demonstrates the potential of this workflow for characterization of lipoprotein composition in clinical studies using small volumes of archived frozen samples. PMID:29634782
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Midttun, Oivind; Townsend, Mary K; Nygård, Ottar; Tworoger, Shelley S; Brennan, Paul; Johansson, Mattias; Ueland, Per Magne
2014-05-01
Knowledge of stability during sample transportation and changes in biomarker concentrations within person over time are paramount for proper design and interpretation of epidemiologic studies based on a single measurement of biomarker status. Therefore, we investigated stability and intraindividual vs. interindividual variation in blood concentrations of biomarkers related to vitamin status, one-carbon metabolism, and the kynurenine pathway. Whole blood (EDTA and heparin, n = 12) was stored with an icepack for 24 or 48 h, and plasma concentrations of 38 biomarkers were determined. Stability was calculated as change per hour, intraclass correlation coefficient (ICC), and simple Spearman correlation. Within-person reproducibility of biomarkers was expressed as ICC in samples collected 1-2 y apart from 40 postmenopausal women and in samples collected up to 3 y apart from 551 patients with stable angina pectoris. Biomarker stability was similar in EDTA and heparin blood. Most biomarkers were essentially stable, except for choline and total homocysteine (tHcy), which increased markedly. Within-person reproducibility in postmenopausal women was excellent (ICC > 0.75) for cotinine, all-trans retinol, cobalamin, riboflavin, α-tocopherol, Gly, pyridoxal, methylmalonic acid, creatinine, pyridoxal 5'-phosphate, and Ser; was good to fair (ICC of 0.74-0.40) for pyridoxic acid, kynurenine, tHcy, cholecalciferol, flavin mononucleotide, kynurenic acid, xanthurenic acid, 3-hydroxykynurenine, sarcosine, anthranilic acid, cystathionine, homoarginine, 3-hydroxyanthranilic acid, betaine, Arg, folate, total cysteine, dimethylglycine, asymmetric dimethylarginine, neopterin, symmetric dimethylarginine, and Trp; and poor (ICC of 0.39-0.15) for methionine sulfoxide, Met, choline, and trimethyllysine. Similar reproducibilities were observed in patients with coronary heart disease. Thus, most biomarkers investigated were essentially stable in cooled whole blood for up to 48 h and had a sufficient within-person reproducibility to allow one-exposure assessment of biomarker status in epidemiologic studies. The Western Norway B Vitamin Intervention Trial was registered at clinicaltrials.gov as NTC00354081.
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Tsikas, Dimitrios
2017-07-15
Tyrosine and tyrosine residues in proteins are attacked by the reactive oxygen and nitrogen species peroxynitrite (O=N-OO - ) to generate 3-nitrotyrosine (3-NT) and 3-nitrotyrosine-proteins (3-NTProt), respectively. 3-NT and 3-NTProt are widely accepted as biomarkers of nitr(os)ative stress. Over the years many different analytical methods have been reported for 3-NT and 3-NTProt. Reported concentrations often differ by more than three orders of magnitude, indicative of serious analytical problems. Strategies to overcome pre-analytical and analytical shortcomings and pitfalls have been proposed. The present review investigated whether recently published work on the quantitative measurement of biological 3-nitrotyrosine did adequately consider the analytical past of this biomolecule. 3-Nitrotyrosine was taken as a representative of biomolecules that occur in biological samples in the pM-to-nM concentration range. This examination revealed that in many cases the main protagonists involved in the publication of scientific work, i.e., authors, reviewers and editors, failed to do so. Learning from the analytical history of 3-nitrotyrosine means advancing analytical and biological science and implies the following key issues. (1) Choosing the most reliable analytical approach in terms of sensitivity and accuracy; presently this is best feasible by stable-isotope dilution tandem mass spectrometry coupled with gas chromatography (GC-MS/MS) or liquid chromatography (LC-MS/MS). (2) Minimizing artificial formation of 3-nitrotyrosine during sample work up, a major pitfall in 3-nitrotyrosine analysis. (3) Validating adequately the final method in the intendent biological matrix and the established concentration range. (4) Inviting experts in the field for critical evaluation of the novelty and reliability of the proposed analytical method, placing special emphasis on the compliance of the analytical outcome with 3-nitrotyrosine concentrations obtained by validated GC-MS/MS and LC-MS/MS methods. Copyright © 2017 Elsevier B.V. All rights reserved.
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Lincoln, Tricia A.; Horan-Ross, Debra A.; McHale, Michael R.; Lawrence, Gregory B.
2006-01-01
The laboratory for analysis of low-ionic-strength water at the U.S. Geological Survey (USGS) Water Science Center in Troy, N.Y., analyzes samples collected by USGS projects throughout the Northeast. The laboratory's quality-assurance program is based on internal and interlaboratory quality-assurance samples and quality-control procedures that were developed to ensure proper sample collection, processing, and analysis. The quality-assurance/quality-control data for the time period addressed in this report were stored in the laboratory's SAS data-management system, which provides efficient review, compilation, and plotting of data. This report presents and discusses results of quality-assurance and quality- control samples analyzed from July 1997 through June 1999. Results for the quality-control samples for 18 analytical procedures were evaluated for bias and precision. Control charts indicate that data for eight of the analytical procedures were occasionally biased for either high-concentration and (or) low-concentration samples but were within control limits; these procedures were: acid-neutralizing capacity, total monomeric aluminum, total aluminum, ammonium, calcium, chloride, specific conductance, and sulfate. The data from the potassium and sodium analytical procedures are insufficient for evaluation. Results from the filter-blank and analytical-blank analyses indicate that the procedures for 11 of 13 analytes were within control limits, although the concentrations for blanks were occasionally outside the control limits. Blank analysis results for chloride showed that 22 percent of blanks did not meet data-quality objectives and results for dissolved organic carbon showed that 31 percent of the blanks did not meet data-quality objectives. Sampling and analysis precision are evaluated herein in terms of the coefficient of variation obtained for triplicate samples in the procedures for 14 of the 18 analytes. At least 90 percent of the samples met data-quality objectives for all analytes except total aluminum (70 percent of samples met objectives) and potassium (83 percent of samples met objectives). Results of the USGS interlaboratory Standard Reference Sample (SRS) Project indicated good data quality for most constituents over the time period. The P-sample (low-ionic-strength constituents) analysis had good ratings in two of these studies and a satisfactory rating in the third. The results of the T-sample (trace constituents) analysis indicated high data quality with good ratings in all three studies. The N-sample (nutrient constituents) studies had one each of excellent, good, and satisfactory ratings. Results of Environment Canada's National Water Research Institute (NWRI) program indicated that at least 80 percent of the samples met data-quality objectives for 9 of the 13 analytes; the exceptions were dissolved organic carbon, ammonium, chloride, and specific conductance. Data-quality objectives were not met for dissolved organic carbon in two NWRI studies, but all of the samples were within control limits for the last study. Data-quality objectives were not met in 41 percent of samples analyzed for ammonium, 25 percent of samples analyzed for chloride, and 30 percent of samples analyzed for specific conductance. Results from blind reference-sample analyses indicated that data-quality objectives were met by at least 84 percent of the samples analyzed for calcium, chloride, magnesium, pH, and potassium. Data-quality objectives were met by 73 percent of those analyzed for sulfate. The data-quality objective was not met for sodium. The data are insufficient for evaluation of the specific conductance results.
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Zamengo, Luca; Frison, Giampietro; Tedeschi, Gianpaola; Frasson, Samuela; Zancanaro, Flavio; Sciarrone, Rocco
2014-10-01
The measurement of blood-alcohol content (BAC) is a crucial analytical determination required to assess if an offence (e.g. driving under the influence of alcohol) has been committed. For various reasons, results of forensic alcohol analysis are often challenged by the defence. As a consequence, measurement uncertainty becomes a critical topic when assessing compliance with specification limits for forensic purposes. The aims of this study were: (1) to investigate major sources of variability for BAC determinations; (2) to estimate measurement uncertainty for routine BAC determinations; (3) to discuss the role of measurement uncertainty in compliance assessment; (4) to set decision rules for a multiple BAC threshold law, as provided in the Italian Highway Code; (5) to address the topic of the zero-alcohol limit from the forensic toxicology point of view; and (6) to discuss the role of significant figures and rounding errors on measurement uncertainty and compliance assessment. Measurement variability was investigated by the analysis of data collected from real cases and internal quality control. The contribution of both pre-analytical and analytical processes to measurement variability was considered. The resulting expanded measurement uncertainty was 8.0%. Decision rules for the multiple BAC threshold Italian law were set by adopting a guard-banding approach. 0.1 g/L was chosen as cut-off level to assess compliance with the zero-alcohol limit. The role of significant figures and rounding errors in compliance assessment was discussed by providing examples which stressed the importance of these topics for forensic purposes. Copyright © 2014 John Wiley & Sons, Ltd.
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Atomic spectrometry and trends in clinical laboratory medicine
NASA Astrophysics Data System (ADS)
Parsons, Patrick J.; Barbosa, Fernando
2007-09-01
Increasing numbers of clinical laboratories are transitioning away from flame and electrothermal AAS methods to those based on ICP-MS. Still, for many laboratories, the choice of instrumentation is based upon (a) the element(s) to be determined, (b) the matrix/matrices to be analyzed, and (c) the expected concentration(s) of the analytes in the matrix. Most clinical laboratories specialize in measuring Se, Zn, Cu, and Al in serum, and/or Pb, Cd, Hg, As, and Cr in blood and/or urine, while other trace elements (e.g., Pt, Au etc.) are measured for therapeutic purposes. Quantitative measurement of elemental species is becoming more widely accepted for nutritional and/or toxicological screening purposes, and ICP-MS interfaced with separation techniques, such as liquid chromatography or capillary electrophoresis, offers the advantage of on-line species determination coupled with very low detection limits. Polyatomic interferences for some key elements such as Se, As, and Cr require instrumentation equipped with dynamic reaction cell or collision cell technologies, or might even necessitate the use of sector field ICP-MS, to assure accurate results. Nonetheless, whatever analytical method is selected for the task, careful consideration must be given both to specimen collection procedures and to the control of pre-analytical variables. Finally, all methods benefit from access to reliable certified reference materials (CRMs). While a variety of reference materials (RMs) are available for trace element measurements in clinical matrices, not all can be classified as CRMs. The major metrological organizations (e.g., NIST, IRMM, NIES) provide a limited number of clinical CRMs, however, secondary reference materials are readily available from commercial organizations and organizers of external quality assessment schemes.
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Lincoln, Tricia A.; Horan-Ross, Debra A.; McHale, Michael R.; Lawrence, Gregory B.
2001-01-01
A laboratory for analysis of low-ionic strength water has been developed at the U.S. Geological Survey (USGS) office in Troy, N.Y., to analyze samples collected by USGS projects in the Northeast. The laboratory's quality-assurance program is based on internal and interlaboratory quality-assurance samples and quality-control procedures developed to ensure proper sample collection, processing, and analysis. The quality-assurance/quality-control data are stored in the laboratory's SAS data-management system, which provides efficient review, compilation, and plotting of quality-assurance/quality-control data. This report presents and discusses samples analyzed from July 1993 through June 1995. Quality-control results for 18 analytical procedures were evaluated for bias and precision. Control charts show that data from seven of the analytical procedures were biased throughout the analysis period for either high-concentration or low-concentration samples but were within control limits; these procedures were: acid-neutralizing capacity, dissolved inorganic carbon, dissolved organic carbon (soil expulsions), chloride, magnesium, nitrate (colorimetric method), and pH. Three of the analytical procedures were occasionally biased but were within control limits; they were: calcium (high for high-concentration samples for May 1995), dissolved organic carbon (high for highconcentration samples from January through September 1994), and fluoride (high in samples for April and June 1994). No quality-control sample has been developed for the organic monomeric aluminum procedure. Results from the filter-blank and analytical-blank analyses indicate that all analytical procedures in which blanks were run were within control limits, although values for a few blanks were outside the control limits. Blanks were not analyzed for acid-neutralizing capacity, dissolved inorganic carbon, fluoride, nitrate (colorimetric method), or pH. Sampling and analysis precision are evaluated herein in terms of the coefficient of variation obtained for triplicate samples in 14 of the 18 procedures. Data-quality objectives were met by more than 90 percent of the samples analyzed in all procedures except total monomeric aluminum (85 percent of samples met objectives), total aluminum (70 percent of samples met objectives), and dissolved organic carbon (85 percent of samples met objectives). Triplicate samples were not analyzed for ammonium, fluoride, dissolved inorganic carbon, or nitrate (colorimetric method). Results of the USGS interlaboratory Standard Reference Sample Program indicated high data quality with a median result of 3.6 of a possible 4.0. Environment Canada's LRTAP interlaboratory study results indicated that more than 85 percent of the samples met data-quality objectives in 6 of the 12 analyses; exceptions were calcium, dissolved organic carbon, chloride, pH, potassium, and sodium. Data-quality objectives were not met for calcium samples in one LRTAP study, but 94 percent of samples analyzed were within control limits for the remaining studies. Data-quality objectives were not met by 35 percent of samples analyzed for dissolved organic carbon, but 94 percent of sample values were within 20 percent of the most probable value. Data-quality objectives were not met for 30 percent of samples analyzed for chloride, but 90 percent of sample values were within 20 percent of the most probable value. Measurements of samples with a pH above 6.0 were biased high in 54 percent of the samples, although 85 percent of the samples met data-quality objectives for pH measurements below 6.0. Data-quality objectives for potassium and sodium were not met in one study (only 33 percent of the samples analyzed met the objectives), although 85 percent of the sample values were within control limits for the other studies. Measured sodium values were above the upper control limit in all studies. Results from blind reference-sample analyses indicated that data
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Oblinger, Carolyn J.
2004-01-01
The Triangle Area Water Supply Monitoring Project was initiated in October 1988 to provide long-term water-quality data for six area water-supply reservoirs and their tributaries. In addition, the project provides data that can be used to determine the effectiveness of large-scale changes in water-resource management practices, document differences in water quality among water-supply types (large multiuse reservoir, small reservoir, run-of-river), and tributary-loading and in-lake data for water-quality modeling of Falls and Jordan Lakes. By September 2001, the project had progressed in four phases and included as many as 34 sites (in 1991). Most sites were sampled and analyzed by the U.S. Geological Survey. Some sites were already a part of the North Carolina Division of Water Quality statewide ambient water-quality monitoring network and were sampled by the Division of Water Quality. The network has provided data on streamflow, physical properties, and concentrations of nutrients, major ions, metals, trace elements, chlorophyll, total organic carbon, suspended sediment, and selected synthetic organic compounds. Project quality-assurance activities include written procedures for sample collection, record management and archive, collection of field quality-control samples (blank samples and replicate samples), and monitoring the quality of field supplies. In addition to project quality-assurance activities, the quality of laboratory analyses was assessed through laboratory quality-assurance practices and an independent laboratory quality-control assessment provided by the U.S. Geological Survey Branch of Quality Systems through the Blind Inorganic Sample Project and the Organic Blind Sample Project.
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Tan, Susanna K; Sahoo, Malaya K; Milligan, Stephen B; Taylor, Nathaniel; Pinsky, Benjamin A
2017-10-01
Detection of Zika virus (ZIKV) RNA in urine is of increasing interest for the diagnosis of ZIKV infection. Pre-analytical variables can significantly impact the stability of RNA in urine. To determine optimal specimen processing protocols that would maximize detection of ZIKV RNA in urine by real-time, reverse transcriptase PCR, we investigated the effect of temperature, initial ZIKV concentration, use of nucleic acid stabilizers, and time on ZIKV RNA levels. Urine samples from healthy donors were spiked with ZIKV using the Exact Diagnostics ® ZIKV Verification Panel, a commercially available panel composed of heat-inactivated ZIKV, at concentrations of 5.0 log 10 copies/mL (ZIKV-high) and 4.0 log 10 copies/mL (ZIKV-low). Samples were stored at room temperature, 4°C, or -80°C and frozen aliquots were exposed to no stabilizer (urine), Buffer ATL (Qiagen, Germantown, MD), or DNA/RNA Shield (Zymo Research, Irvine, CA). ZIKV RNA levels in urine declined steadily at room temperature, though was not significant by 48h (ZIKV-high, p=0.09; ZIKV-low, p=0.20). ZIKV RNA titers were consistently higher when stored at 4°C, suggesting that storage at 4°C can slow the progression of RNA degradation. Freezing urine samples at -80°C resulted in a significant loss of detectable ZIKV RNA in the ZIKV-low group. ZIKV RNA was detected in 5/6 replicates at 3days, 1/6 replicates at 10days, and 1/3 replicates at 30days, with findings reproducible on repeat testing. Presence of either nucleic acid stabilizer in urine corrected this effect, and resulted in recovery of ZIKV RNA in all replicates. Use of a nucleic acid stabilizer in the ZIKV-high group did not add incremental benefit for the detection or quantitation of ZIKV RNA. ZIKV RNA is prone to degradation in urine with loss of detectable virus even when specimens are frozen at -80°C for 10days. Detection of ZIKV-positive urine samples, particularly those containing low ZIKV titers may be aided with the addition of a nucleic acid stabilizer during urine specimen processing. Copyright © 2017. Published by Elsevier B.V.
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Lincoln, Tricia A.; Horan-Ross, Debra A.; McHale, Michael R.; Lawrence, Gregory B.
2006-01-01
The laboratory for analysis of low-ionic-strength water at the U.S. Geological Survey (USGS) Water Science Center in Troy, N.Y., analyzes samples collected by USGS projects throughout the Northeast. The laboratory's quality-assurance program is based on internal and interlaboratory quality-assurance samples and quality-control procedures that were developed to ensure proper sample collection, processing, and analysis. The quality-assurance and quality-control data were stored in the laboratory's LabMaster data-management system, which provides efficient review, compilation, and plotting of data. This report presents and discusses results of quality-assurance and quality-control samples analyzed from July 1999 through June 2001. Results for the quality-control samples for 18 analytical procedures were evaluated for bias and precision. Control charts indicate that data for eight of the analytical procedures were occasionally biased for either high-concentration or low-concentration samples but were within control limits; these procedures were: acid-neutralizing capacity, total monomeric aluminum, total aluminum, calcium, chloride and nitrate (ion chromatography and colormetric method) and sulfate. The total aluminum and dissolved organic carbon procedures were biased throughout the analysis period for the high-concentration sample, but were within control limits. The calcium and specific conductance procedures were biased throughout the analysis period for the low-concentration sample, but were within control limits. The magnesium procedure was biased for the high-concentration and low concentration samples, but was within control limits. Results from the filter-blank and analytical-blank analyses indicate that the procedures for 14 of 15 analytes were within control limits, although the concentrations for blanks were occasionally outside the control limits. The data-quality objective was not met for dissolved organic carbon. Sampling and analysis precision are evaluated herein in terms of the coefficient of variation obtained for triplicate samples in the procedures for 17 of the 18 analytes. At least 90 percent of the samples met data-quality objectives for all analytes except ammonium (81 percent of samples met objectives), chloride (75 percent of samples met objectives), and sodium (86 percent of samples met objectives). Results of the USGS interlaboratory Standard Reference Sample (SRS) Project indicated good data quality over the time period, with most ratings for each sample in the good to excellent range. The P-sample (low-ionic-strength constituents) analysis had one satisfactory rating for the specific conductance procedure in one study. The T-sample (trace constituents) analysis had one satisfactory rating for the aluminum procedure in one study and one unsatisfactory rating for the sodium procedure in another. The remainder of the samples had good or excellent ratings for each study. Results of Environment Canada's National Water Research Institute (NWRI) program indicated that at least 89 percent of the samples met data-quality objectives for 10 of the 14 analytes; the exceptions were ammonium, total aluminum, dissolved organic carbon, and sodium. Results indicate a positive bias for the ammonium procedure in all studies. Data-quality objectives were not met in 50 percent of samples analyzed for total aluminum, 38 percent of samples analyzed for dissolved organic carbon, and 27 percent of samples analyzed for sodium. Results from blind reference-sample analyses indicated that data-quality objectives were met by at least 91 percent of the samples analyzed for calcium, chloride, fluoride, magnesium, pH, potassium, and sulfate. Data-quality objectives were met by 75 percent of the samples analyzed for sodium and 58 percent of the samples analyzed for specific conductance.
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Just the two of us: misalignment of theory and methods in examining dyadic phenomena.
Krasikova, Dina V; LeBreton, James M
2012-07-01
Many organizational phenomena such as leader-member exchange, mentoring, coaching, interpersonal conflict and cooperation, negotiation, performance appraisal, and the employment interview involve inherently dyadic relationships and interactions. Even when theories explicitly acknowledge the dyadic nature of such phenomena, it is not uncommon to observe a disconnection or misalignment between the level of theory and method. Our purpose in the current paper is to discuss how organizational scholars might better align these components of their research endeavors. We discuss how recent developments involving the actor-partner interdependence model (APIM) and reciprocal one-with-many (OWM) models are applicable to studying dyadic phenomena in organizations. The emphasis is on preanalytic considerations associated with collecting and organizing reciprocal dyadic data, types of research questions that APIM and reciprocal OWM models can help answer, and specific analytic techniques involved in testing dyadic hypotheses. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
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[The birth of metapsychology. On the current interpretation of "Entwurf einer Psychologie" (1895)].
Schmidt-Hellerau, C
1995-12-01
The general attitude towards Entwurf einer Psychologie (1895) is to reckon it among Freud's pre-analytic writings, i.e. that part of his work later more or less disowned by the author. Schmidt-Hellerau challenges this assessment by Freud and many of his successors, demonstrating that the Entwurf can legitimately be regarded as a meta-theory resolving - or skirting- the old classification problem of whether psychoanalysis is a science or an art by connecting the hitherto dissociated spheres of soma and psyche and conceptualizing of physiological and psychological processes. See thus, the Entwurf reveals itself as a theoretical document of astonishing modernity and undiminished relevance in that it records Freud's ambitious attempt to overcome the mind-body schism and the divide between neurophysiology and psychology. And it is precisely this problem, the author contends, which Freud's later metapsychology--and the controversies it has aroused--revolves around.
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Methodological Variables in the Analysis of Cell-Free DNA.
Bronkhorst, Abel Jacobus; Aucamp, Janine; Pretorius, Piet J
2016-01-01
In recent years, cell-free DNA (cfDNA) analysis has received increasing amounts of attention as a potential non-invasive screening tool for the early detection of genetic aberrations and a wide variety of diseases, especially cancer. However, except for some prenatal tests and BEAMing, a technique used to detect mutations in various genes of cancer patients, cfDNA analysis is not yet routinely applied in clinical practice. Although some confusing biological factors inherent to the in vivo setting play a key part, it is becoming increasingly clear that this struggle is mainly due to the lack of an analytical consensus, especially as regards quantitative analyses of cfDNA. In order to use quantitative analysis of cfDNA with confidence, process optimization and standardization are crucial. In this work we aim to elucidate the most confounding variables of each preanalytical step that must be considered for process optimization and equivalence of procedures.
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MALDI-TOF mass spectrometry in the clinical mycology laboratory: identification of fungi and beyond.
Posteraro, Brunella; De Carolis, Elena; Vella, Antonietta; Sanguinetti, Maurizio
2013-04-01
MALDI-TOF mass spectrometry (MS) is becoming essential in most clinical microbiology laboratories throughout the world. Its successful use is mainly attributable to the low operational costs, the universality and flexibility of detection, as well as the specificity and speed of analysis. Based on characteristic protein spectra obtained from intact cells - by means of simple, rapid and reproducible preanalytical and analytical protocols - MALDI-TOF MS allows a highly discriminatory identification of yeasts and filamentous fungi starting from colonies. Whenever used early, direct identification of yeasts from positive blood cultures has the potential to greatly shorten turnaround times and to improve laboratory diagnosis of fungemia. More recently, but still at an infancy stage, MALDI-TOF MS is used to perform strain typing and to determine antifungal drug susceptibility. In this article, the authors discuss how the MALDI-TOF MS technology is destined to become a powerful tool for routine mycological diagnostics.
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Habara, P; Marečková, H; Malíčková, K; Potyšová, Z; Hrušková, Z; Zima, T; Tesař, V
2012-01-01
Glomerulonephritides together create a heterogenic group of supposedly immunologically mediated diseases of glomeruli. They still belong among the most frequent causes of chronic renal failure. Detection of podocytes in urine might serve as an important marker of glomerulonephritides activity. The aim of this study was to develop a novel flow cytometric method for the detection of podocyte fragments and podocytes in urine and assess its possible use in clinical practice. We placed emphasis on the improvement of pre-analytic phase. To suppress the autofluorescence of the background, blocking solutions and magnetic separation were used. An additional surface marker CD10 (nephrilysin) was used together with routinely used podocalyxin (PCX) in order to achieve better identification of podocytes. Based on the surface marker expression, three different element types were identified in the urine samples: PCX+/CD10+ elements (EL) (supposedly podocytes), PCX-/CD10+ EL (supposedly parietal epithelial cells) and PCX+ EL. We examined a total of 36 patients who underwent renal biopsy (non-glomerular nephropathy, MGN, FSGS, IgAN, AAV and MPGN) and 27 healthy controls. Negative results were found in non-glomerular nephropathy and in MGN. In patients with FSGS and IgAN, the levels of urine elements were slightly increased. The highest levels of all elements were found in AAV and MPGN. Our first results suggest that flow cytometric detection may distinguish between glomerular and nonglomerular diseases and that the levels of urine elements might correlate with the degree of glomerular destruction.
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Zhou, Fang; Moreira, Andre L
2016-12-01
- In the burgeoning era of molecular genomics, immunoperoxidase (IPOX) testing grows increasingly relevant as an efficient and effective molecular screening tool. Patients with lung carcinoma may especially benefit from the use of IPOX because most lung carcinomas are inoperable at diagnosis and only diagnosed by small tissue biopsy or fine-needle sampling. When such small specimens are at times inadequate for molecular testing, positive IPOX results still provide actionable information. - To describe the benefits and pitfalls of IPOX in the detection of biomarkers in lung carcinoma cytology specimens and small biopsies by summarizing the currently available commercial antibodies, preanalytic variables, and analytic considerations. - PubMed. - Commercial antibodies exist for IPOX detection of aberrant protein expression due to EGFR L858R mutation, EGFR E746_A750 deletion, ALK rearrangement, ROS1 rearrangement, and BRAF V600E mutation, as well as PD-L1 expression in tumor cells. Automated IPOX protocols for ALK and PD-L1 detection were recently approved by the Food and Drug Administration as companion diagnostics for targeted therapies, but consistent interpretive criteria remain to be elucidated, and such protocols do not yet exist for other biomarkers. The inclusion of cytology specimens in clinical trials would expand patients' access to testing and treatment, yet there is a scarcity of clinical trial data regarding the application of IPOX to cytology, which can be attributed to trial designers' lack of familiarity with the advantages and limitations of cytology. The content of this review may be used to inform clinical trial design and advance IPOX validation studies.
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Zakaria, Rosita; Allen, Katrina J; Koplin, Jennifer J; Roche, Peter; Greaves, Ronda F
2016-12-01
Through the introduction of advanced analytical techniques and improved throughput, the scope of dried blood spot testing utilising mass spectrometric methods, has broadly expanded. Clinicians and researchers have become very enthusiastic about the potential applications of dried blood spot based mass spectrometric applications. Analysts on the other hand face challenges of sensitivity, reproducibility and overall accuracy of dried blood spot quantification. In this review, we aim to bring together these two facets to discuss the advantages and current challenges of non-newborn screening applications of dried blood spot quantification by mass spectrometry. To address these aims we performed a key word search of the PubMed and MEDLINE online databases in conjunction with individual manual searches to gather information. Keywords for the initial search included; "blood spot" and "mass spectrometry"; while excluding "newborn"; and "neonate". In addition, databases were restricted to English language and human specific. There was no time period limit applied. As a result of these selection criteria, 194 references were identified for review. For presentation, this information is divided into: 1) clinical applications; and 2) analytical considerations across the total testing process; being pre-analytical, analytical and post-analytical considerations. DBS analysis using MS applications is now broadly applied, with drug monitoring for both therapeutic and toxicological analysis being the most extensively reported. Several parameters can affect the accuracy of DBS measurement and further bridge experiments are required to develop adjustment rules for comparability between dried blood spot measures and the equivalent serum/plasma values. Likewise, the establishment of independent reference intervals for dried blood spot sample matrix is required.
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Khoury, Joseph D; Wang, Wei-Lien; Prieto, Victor G; Medeiros, L Jeffrey; Kalhor, Neda; Hameed, Meera; Broaddus, Russell; Hamilton, Stanley R
2018-02-01
Biomarkers that guide therapy selection are gaining unprecedented importance as targeted therapy options increase in scope and complexity. In conjunction with high-throughput molecular techniques, therapy-guiding biomarker assays based upon immunohistochemistry (IHC) have a critical role in cancer care in that they inform about the expression status of a protein target. Here, we describe the validation procedures for four clinical IHC biomarker assays-PTEN, RB, MLH1, and MSH2-for use as integral biomarkers in the nationwide NCI-Molecular Analysis for Therapy Choice (NCI-MATCH) EAY131 clinical trial. Validation procedures were developed through an iterative process based on collective experience and adaptation of broad guidelines from the FDA. The steps included primary antibody selection; assay optimization; development of assay interpretation criteria incorporating biological considerations; and expected staining patterns, including indeterminate results, orthogonal validation, and tissue validation. Following assay lockdown, patient samples and cell lines were used for analytic and clinical validation. The assays were then approved as laboratory-developed tests and used for clinical trial decisions for treatment selection. Calculations of sensitivity and specificity were undertaken using various definitions of gold-standard references, and external validation was required for the PTEN IHC assay. In conclusion, validation of IHC biomarker assays critical for guiding therapy in clinical trials is feasible using comprehensive preanalytic, analytic, and postanalytic steps. Implementation of standardized guidelines provides a useful framework for validating IHC biomarker assays that allow for reproducibility across institutions for routine clinical use. Clin Cancer Res; 24(3); 521-31. ©2017 AACR . ©2017 American Association for Cancer Research.
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Lincoln, Tricia A.; Horan-Ross, Debra A.; McHale, Michael R.; Lawrence, Gregory B.
2009-01-01
The laboratory for analysis of low-ionic-strength water at the U.S. Geological Survey (USGS) Water Science Center in Troy, N.Y., analyzes samples collected by USGS projects throughout the Northeast. The laboratory's quality-assurance program is based on internal and interlaboratory quality-assurance samples and quality-control procedures that were developed to ensure proper sample collection, processing, and analysis. The quality-assurance and quality-control data were stored in the laboratory's Lab Master data-management system, which provides efficient review, compilation, and plotting of data. This report presents and discusses results of quality-assurance and quality control samples analyzed from July 2003 through June 2005. Results for the quality-control samples for 20 analytical procedures were evaluated for bias and precision. Control charts indicate that data for five of the analytical procedures were occasionally biased for either high-concentration or low-concentration samples but were within control limits; these procedures were: acid-neutralizing capacity, total monomeric aluminum, pH, silicon, and sodium. Seven of the analytical procedures were biased throughout the analysis period for the high-concentration sample, but were within control limits; these procedures were: dissolved organic carbon, chloride, nitrate (ion chromatograph), nitrite, silicon, sodium, and sulfate. The calcium and magnesium procedures were biased throughout the analysis period for the low-concentration sample, but were within control limits. The total aluminum and specific conductance procedures were biased for the high-concentration and low-concentration samples, but were within control limits. Results from the filter-blank and analytical-blank analyses indicate that the procedures for 17 of 18 analytes were within control limits, although the concentrations for blanks were occasionally outside the control limits. The data-quality objective was not met for dissolved organic carbon. Sampling and analysis precision are evaluated herein in terms of the coefficient of variation obtained for triplicate samples in the procedures for 18 of the 22 analytes. At least 85 percent of the samples met data-quality objectives for all analytes except total monomeric aluminum (82 percent of samples met objectives), total aluminum (77 percent of samples met objectives), chloride (80 percent of samples met objectives), fluoride (76 percent of samples met objectives), and nitrate (ion chromatograph) (79 percent of samples met objectives). The ammonium and total dissolved nitrogen did not meet the data-quality objectives. Results of the USGS interlaboratory Standard Reference Sample (SRS) Project indicated good data quality over the time period, with ratings for each sample in the satisfactory, good, and excellent ranges or less than 10 percent error. The P-sample (low-ionic-strength constituents) analysis had one marginal and two unsatisfactory ratings for the chloride procedure. The T-sample (trace constituents)analysis had two unsatisfactory ratings and one high range percent error for the aluminum procedure. The N-sample (nutrient constituents) analysis had one marginal rating for the nitrate procedure. Results of Environment Canada's National Water Research Institute (NWRI) program indicated that at least 84 percent of the samples met data-quality objectives for 11 of the 14 analytes; the exceptions were ammonium, total aluminum, and acid-neutralizing capacity. The ammonium procedure did not meet data quality objectives in all studies. Data-quality objectives were not met in 23 percent of samples analyzed for total aluminum and 45 percent of samples analyzed acid-neutralizing capacity. Results from blind reference-sample analyses indicated that data-quality objectives were met by at least 86 percent of the samples analyzed for calcium, chloride, fluoride, magnesium, pH, potassium, sodium, and sulfate. Data-quality objectives were not met by samples analyzed for fluoride.
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Lincoln, Tricia A.; Horan-Ross, Debra A.; McHale, Michael R.; Lawrence, Gregory B.
2009-01-01
The laboratory for analysis of low-ionic-strength water at the U.S. Geological Survey (USGS) Water Science Center in Troy, N.Y., analyzes samples collected by USGS projects throughout the Northeast. The laboratory's quality-assurance program is based on internal and interlaboratory quality-assurance samples and quality-control procedures that were developed to ensure proper sample collection, processing, and analysis. The quality-assurance and quality-control data were stored in the laboratory's Lab Master data-management system, which provides efficient review, compilation, and plotting of data. This report presents and discusses results of quality-assurance and quality control samples analyzed from July 2005 through June 2007. Results for the quality-control samples for 19 analytical procedures were evaluated for bias and precision. Control charts indicate that data for eight of the analytical procedures were occasionally biased for either high-concentration or low-concentration samples but were within control limits; these procedures were: total aluminum, calcium, magnesium, nitrate (colorimetric method), potassium, silicon, sodium, and sulfate. Eight of the analytical procedures were biased throughout the analysis period for the high-concentration sample, but were within control limits; these procedures were: total aluminum, calcium, dissolved organic carbon, chloride, nitrate (ion chromatograph), potassium, silicon, and sulfate. The magnesium and pH procedures were biased throughout the analysis period for the low-concentration sample, but were within control limits. The acid-neutralizing capacity, total monomeric aluminum, nitrite, and specific conductance procedures were biased for the high-concentration and low-concentration samples, but were within control limits. Results from the filter-blank and analytical-blank analyses indicated that the procedures for 16 of 17 analytes were within control limits, although the concentrations for blanks were occasionally outside the control limits. The data-quality objective was not met for dissolved organic carbon. Sampling and analysis precision are evaluated herein in terms of the coefficient of variation obtained for triplicate samples in the procedures for 18 of the 21 analytes. At least 93 percent of the samples met data-quality objectives for all analytes except acid-neutralizing capacity (85 percent of samples met objectives), total monomeric aluminum (83 percent of samples met objectives), total aluminum (85 percent of samples met objectives), and chloride (85 percent of samples met objectives). The ammonium and total dissolved nitrogen did not meet the data-quality objectives. Results of the USGS interlaboratory Standard Reference Sample (SRS) Project met the Troy Laboratory data-quality objectives for 87 percent of the samples analyzed. The P-sample (low-ionic-strength constituents) analysis had two outliers each in two studies. The T-sample (trace constituents) analysis and the N-sample (nutrient constituents) analysis had one outlier each in two studies. Results of Environment Canada's National Water Research Institute (NWRI) program indicated that at least 85 percent of the samples met data-quality objectives for 11 of the 14 analytes; the exceptions were acid-neutralizing capacity, total aluminum and ammonium. Data-quality objectives were not met in 41 percent of samples analyzed for acid-neutralizing capacity, 50 percent of samples analyzed for total aluminum, and 44 percent of samples analyzed for ammonium. Results from blind reference-sample analyses indicated that data-quality objectives were met by at least 86 percent of the samples analyzed for calcium, magnesium, pH, potassium, and sodium. Data-quality objectives were met by 76 percent of the samples analyzed for chloride, 80 percent of the samples analyzed for specific conductance, and 77 percent of the samples analyzed for sulfate.
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K, Punith; K, Lalitha; G, Suman; Bs, Pradeep; Kumar K, Jayanth
2008-07-01
Is LQAS technique better than cluster sampling technique in terms of resources to evaluate the immunization coverage in an urban area? To assess and compare the lot quality assurance sampling against cluster sampling in the evaluation of primary immunization coverage. Population-based cross-sectional study. Areas under Mathikere Urban Health Center. Children aged 12 months to 23 months. 220 in cluster sampling, 76 in lot quality assurance sampling. Percentages and Proportions, Chi square Test. (1) Using cluster sampling, the percentage of completely immunized, partially immunized and unimmunized children were 84.09%, 14.09% and 1.82%, respectively. With lot quality assurance sampling, it was 92.11%, 6.58% and 1.31%, respectively. (2) Immunization coverage levels as evaluated by cluster sampling technique were not statistically different from the coverage value as obtained by lot quality assurance sampling techniques. Considering the time and resources required, it was found that lot quality assurance sampling is a better technique in evaluating the primary immunization coverage in urban area.
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Performance of biometric quality measures.
Grother, Patrick; Tabassi, Elham
2007-04-01
We document methods for the quantitative evaluation of systems that produce a scalar summary of a biometric sample's quality. We are motivated by a need to test claims that quality measures are predictive of matching performance. We regard a quality measurement algorithm as a black box that converts an input sample to an output scalar. We evaluate it by quantifying the association between those values and observed matching results. We advance detection error trade-off and error versus reject characteristics as metrics for the comparative evaluation of sample quality measurement algorithms. We proceed this with a definition of sample quality, a description of the operational use of quality measures. We emphasize the performance goal by including a procedure for annotating the samples of a reference corpus with quality values derived from empirical recognition scores.
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Lincoln, Tricia A.; Horan-Ross, Debra A.; McHale, Michael R.; Lawrence, Gregory B.
2009-01-01
The laboratory for analysis of low-ionic-strength water at the U.S. Geological Survey (USGS) Water Science Center in Troy, N.Y., analyzes samples collected by USGS projects throughout the Northeast. The laboratory's quality-assurance program is based on internal and interlaboratory quality-assurance samples and quality-control procedures that were developed to ensure proper sample collection, processing, and analysis. The quality-assurance and quality-control data were stored in the laboratory's Lab Master data-management system, which provides efficient review, compilation, and plotting of data. This report presents and discusses results of quality-assurance and quality control samples analyzed from July 2001 through June 2003. Results for the quality-control samples for 19 analytical procedures were evaluated for bias and precision. Control charts indicate that data for six of the analytical procedures were occasionally biased for either high-concentration or low-concentration samples but were within control limits; these procedures were: acid-neutralizing capacity, chloride, magnesium, nitrate (ion chromatography), potassium, and sodium. The calcium procedure was biased throughout the analysis period for the high-concentration sample, but was within control limits. The total monomeric aluminum and fluoride procedures were biased throughout the analysis period for the low-concentration sample, but were within control limits. The total aluminum, pH, specific conductance, and sulfate procedures were biased for the high-concentration and low-concentration samples, but were within control limits. Results from the filter-blank and analytical-blank analyses indicate that the procedures for 16 of 18 analytes were within control limits, although the concentrations for blanks were occasionally outside the control limits. The data-quality objective was not met for the dissolved organic carbon or specific conductance procedures. Sampling and analysis precision are evaluated herein in terms of the coefficient of variation obtained for triplicate samples in the procedures for 18 of the 21 analytes. At least 90 percent of the samples met data-quality objectives for all procedures except total monomeric aluminum (83 percent of samples met objectives), total aluminum (76 percent of samples met objectives), ammonium (73 percent of samples met objectives), dissolved organic carbon (86 percent of samples met objectives), and nitrate (81 percent of samples met objectives). The data-quality objective was not met for the nitrite procedure. Results of the USGS interlaboratory Standard Reference Sample (SRS) Project indicated satisfactory or above data quality over the time period, with most performance ratings for each sample in the good-to-excellent range. The N-sample (nutrient constituents) analysis had one unsatisfactory rating for the ammonium procedure in one study. The T-sample (trace constituents) analysis had one unsatisfactory rating for the magnesium procedure and one marginal rating for the potassium procedure in one study and one unsatisfactory rating for the sodium procedure in another. Results of Environment Canada's National Water Research Institute (NWRI) program indicated that at least 90 percent of the samples met data-quality objectives for 10 of the 14 analytes; the exceptions were acid-neutralizing capacity, ammonium, dissolved organic carbon, and sodium. Data-quality objectives were not met in 37 percent of samples analyzed for acid-neutralizing capacity, 28 percent of samples analyzed for dissolved organic carbon, and 30 percent of samples analyzed for sodium. Results indicate a positive bias for the ammonium procedure in one study and a negative bias in another. Results from blind reference-sample analyses indicated that data-quality objectives were met by at least 90 percent of the samples analyzed for calcium, chloride, magnesium, pH, potassium, and sodium. Data-quality objectives were met by 78 percent of
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Data-quality measures for stakeholder-implemented watershed-monitoring programs
Greve, Adrienne I.
2002-01-01
Community-based watershed groups, many of which collect environmental data, have steadily increased in number over the last decade. The data generated by these programs are often underutilized due to uncertainty in the quality of data produced. The incorporation of data-quality measures into stakeholder monitoring programs lends statistical validity to data. Data-quality measures are divided into three steps: quality assurance, quality control, and quality assessment. The quality-assurance step attempts to control sources of error that cannot be directly quantified. This step is part of the design phase of a monitoring program and includes clearly defined, quantifiable objectives, sampling sites that meet the objectives, standardized protocols for sample collection, and standardized laboratory methods. Quality control (QC) is the collection of samples to assess the magnitude of error in a data set due to sampling, processing, transport, and analysis. In order to design a QC sampling program, a series of issues needs to be considered: (1) potential sources of error, (2) the type of QC samples, (3) inference space, (4) the number of QC samples, and (5) the distribution of the QC samples. Quality assessment is the process of evaluating quality-assurance measures and analyzing the QC data in order to interpret the environmental data. Quality assessment has two parts: one that is conducted on an ongoing basis as the monitoring program is running, and one that is conducted during the analysis of environmental data. The discussion of the data-quality measures is followed by an example of their application to a monitoring program in the Big Thompson River watershed of northern Colorado.
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K, Punith; K, Lalitha; G, Suman; BS, Pradeep; Kumar K, Jayanth
2008-01-01
Research Question: Is LQAS technique better than cluster sampling technique in terms of resources to evaluate the immunization coverage in an urban area? Objective: To assess and compare the lot quality assurance sampling against cluster sampling in the evaluation of primary immunization coverage. Study Design: Population-based cross-sectional study. Study Setting: Areas under Mathikere Urban Health Center. Study Subjects: Children aged 12 months to 23 months. Sample Size: 220 in cluster sampling, 76 in lot quality assurance sampling. Statistical Analysis: Percentages and Proportions, Chi square Test. Results: (1) Using cluster sampling, the percentage of completely immunized, partially immunized and unimmunized children were 84.09%, 14.09% and 1.82%, respectively. With lot quality assurance sampling, it was 92.11%, 6.58% and 1.31%, respectively. (2) Immunization coverage levels as evaluated by cluster sampling technique were not statistically different from the coverage value as obtained by lot quality assurance sampling techniques. Considering the time and resources required, it was found that lot quality assurance sampling is a better technique in evaluating the primary immunization coverage in urban area. PMID:19876474
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Spahr, N.E.; Boulger, R.W.
1997-01-01
Quality-control samples provide part of the information needed to estimate the bias and variability that result from sample collection, processing, and analysis. Quality-control samples of surface water collected for the Upper Colorado River National Water-Quality Assessment study unit for water years 1995?96 are presented and analyzed in this report. The types of quality-control samples collected include pre-processing split replicates, concurrent replicates, sequential replicates, post-processing split replicates, and field blanks. Analysis of the pre-processing split replicates, concurrent replicates, sequential replicates, and post-processing split replicates is based on differences between analytical results of the environmental samples and analytical results of the quality-control samples. Results of these comparisons indicate that variability introduced by sample collection, processing, and handling is low and will not affect interpretation of the environmental data. The differences for most water-quality constituents is on the order of plus or minus 1 or 2 lowest rounding units. A lowest rounding unit is equivalent to the magnitude of the least significant figure reported for analytical results. The use of lowest rounding units avoids some of the difficulty in comparing differences between pairs of samples when concentrations span orders of magnitude and provides a measure of the practical significance of the effect of variability. Analysis of field-blank quality-control samples indicates that with the exception of chloride and silica, no systematic contamination of samples is apparent. Chloride contamination probably was the result of incomplete rinsing of the dilute cleaning solution from the outlet ports of the decaport sample splitter. Silica contamination seems to have been introduced by the blank water. Sampling and processing procedures for water year 1997 have been modified as a result of these analyses.
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Masucci, Giuseppe V; Cesano, Alessandra; Hawtin, Rachael; Janetzki, Sylvia; Zhang, Jenny; Kirsch, Ilan; Dobbin, Kevin K; Alvarez, John; Robbins, Paul B; Selvan, Senthamil R; Streicher, Howard Z; Butterfield, Lisa H; Thurin, Magdalena
2016-01-01
Immunotherapies have emerged as one of the most promising approaches to treat patients with cancer. Recently, there have been many clinical successes using checkpoint receptor blockade, including T cell inhibitory receptors such as cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed cell death-1 (PD-1). Despite demonstrated successes in a variety of malignancies, responses only typically occur in a minority of patients in any given histology. Additionally, treatment is associated with inflammatory toxicity and high cost. Therefore, determining which patients would derive clinical benefit from immunotherapy is a compelling clinical question. Although numerous candidate biomarkers have been described, there are currently three FDA-approved assays based on PD-1 ligand expression (PD-L1) that have been clinically validated to identify patients who are more likely to benefit from a single-agent anti-PD-1/PD-L1 therapy. Because of the complexity of the immune response and tumor biology, it is unlikely that a single biomarker will be sufficient to predict clinical outcomes in response to immune-targeted therapy. Rather, the integration of multiple tumor and immune response parameters, such as protein expression, genomics, and transcriptomics, may be necessary for accurate prediction of clinical benefit. Before a candidate biomarker and/or new technology can be used in a clinical setting, several steps are necessary to demonstrate its clinical validity. Although regulatory guidelines provide general roadmaps for the validation process, their applicability to biomarkers in the cancer immunotherapy field is somewhat limited. Thus, Working Group 1 (WG1) of the Society for Immunotherapy of Cancer (SITC) Immune Biomarkers Task Force convened to address this need. In this two volume series, we discuss pre-analytical and analytical (Volume I) as well as clinical and regulatory (Volume II) aspects of the validation process as applied to predictive biomarkers for cancer immunotherapy. To illustrate the requirements for validation, we discuss examples of biomarker assays that have shown preliminary evidence of an association with clinical benefit from immunotherapeutic interventions. The scope includes only those assays and technologies that have established a certain level of validation for clinical use (fit-for-purpose). Recommendations to meet challenges and strategies to guide the choice of analytical and clinical validation design for specific assays are also provided.
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Presley, Todd K.; Jamison, Marcael T.J.; Young, Stacie T.M.
2008-01-01
Storm runoff water-quality samples were collected as part of the State of Hawaii Department of Transportation Stormwater Monitoring Program. The program is designed to assess the effects of highway runoff and urban runoff on Halawa Stream and to assess the effects from the H-1 storm drain on Manoa Stream. For this program, rainfall data were collected at three stations, continuous discharge data at four stations, and water-quality data at six stations, which include the four continuous discharge stations. This report summarizes rainfall, discharge, and water-quality data collected between July 1, 2007, and June 30, 2008. A total of 16 environmental samples were collected over two storms during July 1, 2007, to June 30, 2008, within the Halawa Stream drainage area. Samples were analyzed for total suspended solids, total dissolved solids, nutrients, chemical oxygen demand, and selected trace metals (cadmium, chromium, copper, lead, and zinc). Additionally, grab samples were analyzed for oil and grease, total petroleum hydrocarbons, fecal coliform, and biological oxygen demand. Some samples were analyzed for only a partial list of these analytes because an insufficient volume of sample was collected by the automatic samplers. Three additional quality-assurance/quality-control samples were collected concurrently with the storm samples. A total of 16 environmental samples were collected over four storms during July 1, 2007, to June 30, 2008 at the H-1 Storm Drain. All samples at this site were collected using an automatic sampler. Samples generally were analyzed for total suspended solids, nutrients, chemical oxygen demand, oil and grease, total petroleum hydrocarbons, and selected trace metals (cadmium, chromium, copper, lead, nickel, and zinc), although some samples were analyzed for only a partial list of these analytes. During the storm of January 29, 2008, 10 discrete samples were collected. Varying constituent concentrations were detected for the samples collected at different times during this storm event. Two quality-assurance/quality-control samples were collected concurrently with the storm samples. Three additional quality-assurance/quality-control samples were collected during routine sampler maintenance to check the effectiveness of equipment-cleaning procedures.
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Gounder, Shakti; Tayler-Smith, Katherine; Khogali, Mohammed; Raikabula, Maopa; Harries, Anthony D
2013-07-01
In Fiji, patients with suspected pulmonary tuberculosis (PTB) currently submit three sputum specimens for smear microscopy for acid-fast bacilli, but there is little information about how well this practice is carried out. A cross-sectional retrospective review was carried out in all four TB diagnostic laboratories in Fiji to determine among new patients presenting with suspected PTB in 2011: the quality of submitted sputum; the number of sputum samples submitted; the relationship between quality and number of submitted samples to smear-positivity; and positive yield from first, second and third samples. Of 1940 patients with suspected PTB, 3522 sputum samples were submitted: 997 (51.4%) patients submitted one sample, 304 (15.7%) patients submitted two samples and 639 (32.9%) submitted three samples. Sputum quality was recorded in 2528 (71.8%) of samples, of which 1046 (41.4%) were of poor quality. Poor quality sputum was more frequent in females, inpatients and children (0-14 years). Good quality sputum and a higher number of submitted samples positively correlated with smear-positivity for acid-fast bacilli. There were 122 (6.3%) patients with suspected PTB who were sputum smear positive. Of those, 89 had submitted three sputum samples: 79 (89%) were diagnosed based on the first sputum sample, 6 (7%) on the second sample and 4 (4%) on the third sample. This study shows that there are deficiencies in the practice of sputum smear examination in Fiji with respect to sputum quality and recommended number of submitted samples, although the results support the continued use of three sputum samples for TB diagnosis. Ways to improve sputum quality and adherence to recommended guidelines are needed.
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Wright, Peter R.; McMahon, Peter B.; Mueller, David K.; Clark, Melanie L.
2012-01-01
In June 2010, the U.S. Environmental Protection Agency installed two deep monitoring wells (MW01 and MW02) near Pavillion, Wyoming, to study groundwater quality. During April and May 2012, the U.S Geological Survey, in cooperation with the Wyoming Department of Environmental Quality, collected groundwater-quality data and quality-control data from monitoring well MW01 and, following well redevelopment, quality-control data for monitoring well MW02. Two groundwater-quality samples were collected from well MW01—one sample was collected after purging about 1.5 borehole volumes, and a second sample was collected after purging 3 borehole volumes. Both samples were collected and processed using methods designed to minimize atmospheric contamination or changes to water chemistry. Groundwater-quality samples were analyzed for field water-quality properties (water temperature, pH, specific conductance, dissolved oxygen, oxidation potential); inorganic constituents including naturally occurring radioactive compounds (radon, radium-226 and radium-228); organic constituents; dissolved gasses; stable isotopes of methane, water, and dissolved inorganic carbon; and environmental tracers (carbon-14, chlorofluorocarbons, sulfur hexafluoride, tritium, helium, neon, argon, krypton, xenon, and the ratio of helium-3 to helium-4). Quality-control sample results associated with well MW01 were evaluated to determine the extent to which environmental sample analytical results were affected by bias and to evaluate the variability inherent to sample collection and laboratory analyses. Field documentation, environmental data, and quality-control data for activities that occurred at the two monitoring wells during April and May 2012 are presented.
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Skinner, Kenneth D.
2018-05-11
Groundwater-quality samples and water-level data were collected from 36 wells in the Jerome/Gooding County area of the eastern Snake River Plain aquifer during June 2017. The wells included 30 wells sampled for the U.S. Geological Survey’s National Water-Quality Assessment project, plus an additional 6 wells were selected to increase spatial distribution. The data provide water managers with the ability for an improved understanding of groundwater quality and flow directions in the area. Groundwater-quality samples were analyzed for nutrients, major ions, trace elements, and stable isotopes of water. Quality-assurance and quality-control measures consisted of multiple blank samples and a sequential replicate sample. All data are available online at the USGS National Water Information System.
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Cuffney, T.F.; Gurtz, M.E.; Meador, M.R.
1993-01-01
Benthic invertebrate samples are collected as part of the U.S. Geological Survey's National Water-Quality Assessment Program. This is a perennial, multidisciplinary program that integrates biological, physical, and chemical indicators of water quality to evaluate status and trends and to develop an understanding of the factors controlling observed water quality. The Program examines water quality in 60 study units (coupled ground- and surface-water systems) that encompass most of the conterminous United States and parts of Alaska and Hawaii. Study-unit teams collect and process qualitative and semi-quantitative invertebrate samples according to standardized procedures. These samples are processed (elutriated and subsampled) in the field to produce as many as four sample components: large-rare, main-body, elutriate, and split. Each sample component is preserved in 10-percent formalin, and two components, large-rare and main-body, are sent to contract laboratories for further processing. The large-rare component is composed of large invertebrates that are removed from the sample matrix during field processing and placed in one or more containers. The main-body sample component consists of the remaining sample materials (sediment, detritus, and invertebrates) and is subsampled in the field to achieve a volume of 750 milliliters or less. The remaining two sample components, elutriate and split, are used for quality-assurance and quality-control purposes. Contract laboratories are used to identify and quantify invertebrates from the large-rare and main-body sample components according to the procedures and guidelines specified within this document. These guidelines allow the use of subsampling techniques to reduce the volume of sample material processed and to facilitate identifications. These processing procedures and techniques may be modified if the modifications provide equal or greater levels of accuracy and precision. The intent of sample processing is to determine the quantity of each taxon present in the semi-quantitative samples or to list the taxa present in qualitative samples. The processing guidelines provide standardized laboratory forms, sample labels, detailed sample processing flow charts, standardized format for electronic data, quality-assurance procedures and checks, sample tracking standards, and target levels for taxonomic determinations. The contract laboratory (1) is responsible for identifications and quantifications, (2) constructs reference collections, (3) provides data in hard copy and electronic forms, (4) follows specified quality-assurance and quality-control procedures, and (5) returns all processed and unprocessed portions of the samples. The U.S. Geological Survey's Quality Management Group maintains a Biological Quality-Assurance Unit, located at the National Water-Quality Laboratory, Arvada, Colorado, to oversee the use of contract laboratories and ensure the quality of data obtained from these laboratories according to the guidelines established in this document. This unit establishes contract specifications, reviews contractor performance (timeliness, accuracy, and consistency), enters data into the National Water Information System-II data base, maintains in-house reference collections, deposits voucher specimens in outside museums, and interacts with taxonomic experts within and outside the U.S. Geological Survey. This unit also modifies the existing sample processing and quality-assurance guidelines, establishes criteria and testing procedures for qualifying potential contract laboratories, identifies qualified taxonomic experts, and establishes voucher collections.
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Introduction to Field Water-Quality Methods for the Collection of Metals - 2007 Project Summary
Allen, Monica L.
2008-01-01
The U.S. Geological Survey (USGS), Region VI of the U.S. Environmental Protection Agency (USEPA), and the Osage Nation presented three 3-day workshops, in June-August 2007, entitled ?Introduction to Field Water-Quality Methods for the Collection of Metals.? The purpose of the workshops was to provide instruction to tribes within USEPA Region VI on various USGS surface-water measurement methods and water-quality sampling protocols for the collection of surface-water samples for metals analysis. Workshop attendees included members from over 22 tribes and pueblos. USGS instructors came from Oklahoma, New Mexico, and Georgia. Workshops were held in eastern and south-central Oklahoma and New Mexico and covered many topics including presampling preparation, water-quality monitors, and sampling for metals in surface water. Attendees spent one full classroom day learning the field methods used by the USGS Water Resources Discipline and learning about the complexity of obtaining valid water-quality and quality-assurance data. Lectures included (1) a description of metal contamination sources in surface water; (2) introduction on how to select field sites, equipment, and laboratories for sample analysis; (3) collection of sediment in surface water; and (4) utilization of proper protocol and methodology for sampling metals in surface water. Attendees also were provided USGS sampling equipment for use during the field portion of the class so they had actual ?hands-on? experience to take back to their own organizations. The final 2 days of the workshop consisted of field demonstrations of current USGS water-quality sample-collection methods. The hands-on training ensured that attendees were exposed to and experienced proper sampling procedures. Attendees learned integrated-flow techniques during sample collection, field-property documentation, and discharge measurements and calculations. They also used enclosed chambers for sample processing and collected quality-assurance samples to verify their techniques. Benefits of integrated water-quality sample-collection methods are varied. Tribal environmental programs now have the ability to collect data that are comparable across watersheds. The use of consistent sample collection, manipulation, and storage techniques will provide consistent quality data that will enhance the understanding of local water resources. The improved data quality also will help the USEPA better document the condition of the region?s water. Ultimately, these workshops equipped tribes to use uniform sampling methods and to provide consistent quality data that are comparable across the region.
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Rahman, Mohammad Sofiqur; Yoshida, Naoko; Sugiura, Sakura; Tsuboi, Hirohito; Keila, Tep; Kiet, Heng Bun; Zin, Theingi; Tanimoto, Tsuyoshi; Kimura, Kazuko
2018-03-01
To evaluate the quality of omeprazole personally imported into Japan via the Internet and to compare the quality of these samples with previously collected samples from two other Asian countries. The samples were evaluated by observation, authenticity investigation and pharmacopoeial quality analysis. Quality comparison of some selected samples was carried out by dissolution profiling, Raman spectroscopy and principle component analysis (PCA). Observation of the Internet sites and samples revealed some discrepancies including the delivery of a wrong sample and the selling of omeprazole without a prescription, although it is a prescription medicine. Among the 28 samples analysed, all passed the identification test, 26 (93%) passed the quantity and content uniformity tests and all passed the dissolution test. Dissolution profiling confirmed that all the personally imported omeprazole samples remained intact in the acid medium. On the other hand, six samples from two of the same manufacturers, previously collected during surveys in Cambodia and Myanmar, frequently showed premature omeprazole release in acid. Raman spectroscopy and PCA showed significant variation between omeprazole formulations in personally imported samples and the samples from Cambodia and Myanmar. Our results indicate that the pharmaceutical quality of omeprazole purchased through the Internet was sufficient, as determined by pharmacopeial tests. However, omeprazole formulations distributed in different market segments by the same manufacturers were of diverse quality. Measures are needed to ensure consistent quality of products and to prevent entry of substandard products into the legitimate supply chain. © 2018 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.
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Methods for collecting algal samples as part of the National Water-Quality Assessment Program
Porter, Stephen D.; Cuffney, Thomas F.; Gurtz, Martin E.; Meador, Michael R.
1993-01-01
Benthic algae (periphyton) and phytoplankton communities are characterized in the U.S. Geological Survey's National Water-Quality Assessment Program as part of an integrated physical, chemical, and biological assessment of the Nation's water quality. This multidisciplinary approach provides multiple lines of evidence for evaluating water-quality status and trends, and for refining an understanding of the factors that affect water-quality conditions locally, regionally, and nationally. Water quality can be characterized by evaluating the results of qualitative and quantitative measurements of the algal community. Qualitative periphyton samples are collected to develop of list of taxa present in the sampling reach. Quantitative periphyton samples are collected to measure algal community structure within selected habitats. These samples of benthic algal communities are collected from natural substrates, using the sampling methods that are most appropriate for the habitat conditions. Phytoplankton samples may be collected in large nonwadeable streams and rivers to meet specific program objectives. Estimates of algal biomass (chlorophyll content and ash-free dry mass) also are optional measures that may be useful for interpreting water-quality conditions. A nationally consistent approach provides guidance on site, reach, and habitat selection, as well as information on methods and equipment for qualitative and quantitative sampling. Appropriate quality-assurance and quality-control guidelines are used to maximize the ability to analyze data locally, regionally, and nationally.
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7 CFR 58.929 - Frequency of sampling for quality control.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 7 Agriculture 3 2011-01-01 2011-01-01 false Frequency of sampling for quality control. 58.929... Service 1 Operations and Operating Procedures § 58.929 Frequency of sampling for quality control. (a... to control composition. On continuous production runs, enough samples shall be taken throughout the...
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Kaur, Harparkash; Allan, Elizabeth Louise; Mamadu, Ibrahim; Hall, Zoe; Ibe, Ogochukwu; El Sherbiny, Mohamed; van Wyk, Albert; Yeung, Shunmay; Swamidoss, Isabel; Green, Michael D; Dwivedi, Prabha; Culzoni, Maria Julia; Clarke, Siân; Schellenberg, David; Fernández, Facundo M; Onwujekwe, Obinna
2015-01-01
Artemisinin-based combination therapies are recommended by the World Health Organisation (WHO) as first-line treatment for Plasmodium falciparum malaria, yet medication must be of good quality for efficacious treatment. A recent meta-analysis reported 35% (796/2,296) of antimalarial drug samples from 21 Sub-Saharan African countries, purchased from outlets predominantly using convenience sampling, failed chemical content analysis. We used three sampling strategies to purchase artemisinin-containing antimalarials (ACAs) in Enugu metropolis, Nigeria, and compared the resulting quality estimates. ACAs were purchased using three sampling approaches--convenience, mystery clients and overt, within a defined area and sampling frame in Enugu metropolis. The active pharmaceutical ingredients were assessed using high-performance liquid chromatography and confirmed by mass spectrometry at three independent laboratories. Results were expressed as percentage of APIs stated on the packaging and used to categorise each sample as acceptable quality, substandard, degraded, or falsified. Content analysis of 3024 samples purchased from 421 outlets using convenience (n=200), mystery (n=1,919) and overt (n=905) approaches, showed overall 90.8% ACAs to be of acceptable quality, 6.8% substandard, 1.3% degraded and 1.2% falsified. Convenience sampling yielded a significantly higher prevalence of poor quality ACAs, but was not evident by the mystery and overt sampling strategies both of which yielded results that were comparable between each other. Artesunate (n=135; 4 falsified) and dihydroartemisinin (n=14) monotherapy tablets, not recommended by WHO, were also identified. Randomised sampling identified fewer falsified ACAs than previously reported by convenience approaches. Our findings emphasise the need for specific consideration to be given to sampling frame and sampling approach if representative information on drug quality is to be obtained.
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Olaoye, O A; Onilude, A A
2009-11-01
To assess the microbiological quality of sachet-packaged drinking water in Western Nigeria and its impact on public health. Cross-sectional microbiological testing. Ninety-two sachet-packaged water samples were analysed for microbiological and metal qualities. Total bacterial and coliform counts were determined, and the presence of Escherichia coli, an important water quality indicator, was tested. The level of conformity of the water processors with the guidelines of Nigeria's quality regulatory agency was also determined. Varying levels of microbial contamination were recorded in samples from the different sampling locations. The total bacteria count ranged between 2.86 and 3.45log colony-forming units (cfu)/ml. The highest coliform count recorded was 1.62log cfu/ml. Faecal coliform E. coli was detected in one sample from Oke-Iho and one sample from Okaka, representing 2.2% of total samples. Lead and manganese were not found in any of the samples. However, iron was detected and the highest iron concentration (0.10mg/l) was detected in samples from Ikorodu. The bacteria that were identified from the water samples included E. coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Klebsiella sp., Proteus vulgaris, Alcaligenes faecalis, Bacillus cereus, Staphylococcus aureus, Streptococcus lactis, Aeromonas sp. and Micrococcus luteum. Many of the water processors did not comply with the guidelines of the quality regulatory agency. Some of the sachet-packaged samples of drinking water were of poor quality. The results indicate a need for Nigeria's quality regulatory agency to take appropriate measures in safeguarding public health.
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Performance evaluation of no-reference image quality metrics for face biometric images
NASA Astrophysics Data System (ADS)
Liu, Xinwei; Pedersen, Marius; Charrier, Christophe; Bours, Patrick
2018-03-01
The accuracy of face recognition systems is significantly affected by the quality of face sample images. The recent established standardization proposed several important aspects for the assessment of face sample quality. There are many existing no-reference image quality metrics (IQMs) that are able to assess natural image quality by taking into account similar image-based quality attributes as introduced in the standardization. However, whether such metrics can assess face sample quality is rarely considered. We evaluate the performance of 13 selected no-reference IQMs on face biometrics. The experimental results show that several of them can assess face sample quality according to the system performance. We also analyze the strengths and weaknesses of different IQMs as well as why some of them failed to assess face sample quality. Retraining an original IQM by using face database can improve the performance of such a metric. In addition, the contribution of this paper can be used for the evaluation of IQMs on other biometric modalities; furthermore, it can be used for the development of multimodality biometric IQMs.
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Lincoln, Tricia A.; Horan-Ross, Debra A.; McHale, Michael R.; Lawrence, Gregory B.
2005-01-01
Results from blind reference-sample analyses indicated that data-quality objectives were met by at least 90 percent of the calcium, pH, potassium, and sodium samples. Data-quality objectives were met by 77 percent of the chloride samples, 83 percent of the magnesium samples, and 80 percent of the sulfate samples. There is insufficient data to evaluate the specific conductance samples.
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Uncertainties in selected river water quality data
NASA Astrophysics Data System (ADS)
Rode, M.; Suhr, U.
2007-02-01
Monitoring of surface waters is primarily done to detect the status and trends in water quality and to identify whether observed trends arise from natural or anthropogenic causes. Empirical quality of river water quality data is rarely certain and knowledge of their uncertainties is essential to assess the reliability of water quality models and their predictions. The objective of this paper is to assess the uncertainties in selected river water quality data, i.e. suspended sediment, nitrogen fraction, phosphorus fraction, heavy metals and biological compounds. The methodology used to structure the uncertainty is based on the empirical quality of data and the sources of uncertainty in data (van Loon et al., 2005). A literature review was carried out including additional experimental data of the Elbe river. All data of compounds associated with suspended particulate matter have considerable higher sampling uncertainties than soluble concentrations. This is due to high variability within the cross section of a given river. This variability is positively correlated with total suspended particulate matter concentrations. Sampling location has also considerable effect on the representativeness of a water sample. These sampling uncertainties are highly site specific. The estimation of uncertainty in sampling can only be achieved by taking at least a proportion of samples in duplicates. Compared to sampling uncertainties, measurement and analytical uncertainties are much lower. Instrument quality can be stated well suited for field and laboratory situations for all considered constituents. Analytical errors can contribute considerably to the overall uncertainty of river water quality data. Temporal autocorrelation of river water quality data is present but literature on general behaviour of water quality compounds is rare. For meso scale river catchments (500-3000 km2) reasonable yearly dissolved load calculations can be achieved using biweekly sample frequencies. For suspended sediments none of the methods investigated produced very reliable load estimates when weekly concentrations data were used. Uncertainties associated with loads estimates based on infrequent samples will decrease with increasing size of rivers.
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Uncertainties in selected surface water quality data
NASA Astrophysics Data System (ADS)
Rode, M.; Suhr, U.
2006-09-01
Monitoring of surface waters is primarily done to detect the status and trends in water quality and to identify whether observed trends arise form natural or anthropogenic causes. Empirical quality of surface water quality data is rarely certain and knowledge of their uncertainties is essential to assess the reliability of water quality models and their predictions. The objective of this paper is to assess the uncertainties in selected surface water quality data, i.e. suspended sediment, nitrogen fraction, phosphorus fraction, heavy metals and biological compounds. The methodology used to structure the uncertainty is based on the empirical quality of data and the sources of uncertainty in data (van Loon et al., 2006). A literature review was carried out including additional experimental data of the Elbe river. All data of compounds associated with suspended particulate matter have considerable higher sampling uncertainties than soluble concentrations. This is due to high variability's within the cross section of a given river. This variability is positively correlated with total suspended particulate matter concentrations. Sampling location has also considerable effect on the representativeness of a water sample. These sampling uncertainties are highly site specific. The estimation of uncertainty in sampling can only be achieved by taking at least a proportion of samples in duplicates. Compared to sampling uncertainties measurement and analytical uncertainties are much lower. Instrument quality can be stated well suited for field and laboratory situations for all considered constituents. Analytical errors can contribute considerable to the overall uncertainty of surface water quality data. Temporal autocorrelation of surface water quality data is present but literature on general behaviour of water quality compounds is rare. For meso scale river catchments reasonable yearly dissolved load calculations can be achieved using biweekly sample frequencies. For suspended sediments none of the methods investigated produced very reliable load estimates when weekly concentrations data were used. Uncertainties associated with loads estimates based on infrequent samples will decrease with increasing size of rivers.
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This protocol describes how quality control samples should be handled in the field, and was designed as a quick reference source for the field staff. The protocol describes quality control samples for air-VOCs, air-particles, water samples, house dust, soil, urine, blood, hair, a...
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Araujo, Pedro; Bjørkkjær, Tormod; Frøyland, Livar; Waagbø, Rune
2018-02-01
It studies on the factors that affect the stability of fatty acid profiles from human blood specimens are generally performed by evaluating the effect of a single factor on an individual fatty acid and excluding a considerable amount of data from the total fatty acid profiles. The stability of fatty acids from plasma, serum and red blood cells (RBC) was evaluated in terms of time, temperature, antioxidant and thawing. The fatty acids were methylated and analyzed by gas chromatography. The large volume of data is evaluated simultaneously and automatically by observing an Excel-based colour scale that indicates whether the fatty acid profiles have changed significantly as a result of the storage time (0-52weeks), temperature (-20°C/-80°C), butylated hydroxytoluene (BHT) antioxidant (presence/absence) or thawing (single/multiple). Fatty acids from plasma were stable at both temperatures (-20°C/-80°C) regardless of BHT. Fatty acids from serum without BHT degrades faster at -80°C than -20°C and fatty acids from RBC without BHT degrades faster at -20°C than -80°C. Addition of BHT inhibits this effect in serum and RBC. Multiple thawing of RBC without BHT demonstrated that polyunsaturated fatty acids were generally more susceptible for changes at -80°C than at -20°C while BHT prevents partially this effect. This study draws attention to the importance of pre-analytical considerations when storing blood samples in biobanks and the need of careful judgments when analyzing fatty acids profiles. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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Skov, Louise; Holm, Karen Marie Dollerup; Johansen, Sys Stybe; Linnet, Kristian
2016-09-01
To interpret postmortem toxicology results, reference concentrations for non-toxic and toxic levels are needed. Usually, measurements are performed in blood, but because of postmortem redistribution phenomena this may not be optimal. Rather, measurement in the target organ of psychoactive drugs, the brain, might be considered. Here we present reference concentrations of femoral blood and brain tissue of selected benzodiazepines (BZDs). Using LC-MS/MS, we quantified alprazolam, bromazepam, chlordiazepoxide, diazepam, and the metabolites desmethyldiazepam, oxazepam and temazepam in postmortem femoral blood and brain tissue in 104 cases. BZDs were judged to be unrelated to the cause of death in 88 cases and contributing to death in 16 cases. No cases were found with cause of death solely attributed to BZD poisoning. All BZDs investigated tended to have higher concentrations in brain than in blood with median brain-blood ratios ranging from 1.1 to 2.3. A positive correlation between brain and blood concentrations was found with R(2) values from 0.51 to 0.95. Our reported femoral blood concentrations concur with literature values, but sparse information on brain concentration was available. Drug-metabolite ratios were similar in brain and blood for most compounds. Duplicate measurements of brain samples showed that the pre-analytical variation in brain (5.9%) was relatively low, supporting the notion that brain tissue is a suitable postmortem specimen. The reported concentrations in both brain and blood can be used as reference values when evaluating postmortem cases. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Fania, Chiara; Arosio, Beatrice; Capitanio, Daniele; Torretta, Enrica; Gussago, Cristina; Ferri, Evelyn; Mari, Daniela; Gelfi, Cecilia
2017-01-01
In the diagnosis of Alzheimer's disease (AD) total tau (T-tau), tau phosphorylated at threonine 181 (P-tau181), and the 42 amino acid isoform of alpha β-amyloid (Aβ) are well established surrogate CSF markers. However, there is a constant need for new diagnostic markers to identify the disease at a very early stage. The identification of new molecules for AD diagnosis and monitoring in CSF is hampered by several "confounding" factors including intra- and inter-individual, pre-analytical and analytical variabilities. In an attempt to partially overcome patient's variability and to determine new molecules significantly dysregulated in CSF, we assessed the proteome profile of low molecular weight protein species in CSF and serum of the same patients. CSFs and sera from 36 ADs, 32 iNPHs (idiopathic normal pressure hydrocephalus) and 12 controls were compared by MALDI profiling (non-parametric statistics, CV<20%, AUC>0.750). After protein identification by mass spectrometry, the proteoform composition was assessed by 2-D DIGE/MS. Results indicated that CSF of iNPH can be used as control. Serum and CSF of AD patients shows a specific protein profile compared to iNPH samples. A variation (p<0.01) of Apo A-1 levels in AD, together with a specific dysregulation of Apo A-1 proteoforms was observed. The profiling of CSF and serum of the same patients, suggests that the decrement of total Apo A-1 occurs specifically in CSF. Serum and CSF of AD shows a characteristic Apo A-1 proteoform pattern suggesting it as potential marker which can support the clinical workflow adopted for AD diagnosis and progression.
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Cadamuro, Janne; Gaksch, Martin; Wiedemann, Helmut; Lippi, Giuseppe; von Meyer, Alexander; Pertersmann, Astrid; Auer, Simon; Mrazek, Cornelia; Kipman, Ulrike; Felder, Thomas K; Oberkofler, Hannes; Haschke-Becher, Elisabeth
2018-04-01
Inappropriate utilization of laboratory resources is an increasing concern especially in high-throughput facilities. Until now, no reliable information has been published addressing to which extent laboratory results are actually used for clinical decision-making. Therefore, we aimed to close this gap using a novel retrospective approach including a survey of clinicians and nurses. We retrospectively evaluated the number of re-orders for potassium (K), lactate dehydrogenase (LD), aspartate-aminotransferase (AST), activated partial thromboplastin-time (APTT) and prothrombin-time/INR (PT/INR), after the initial order had to be cancelled due to preanalytical non-conformities. We analyzed subgroups regarding time to re-order, ward and sample priority (urgent vs. routine). Subsequently, we surveyed clinicians and nurses, asking for their estimate of the amount of failed re-orders as well as for possible reasons. From initially cancelled tests, only ~20% of K, LD, AST and ~30% of APTT and PT/INR tests were re-ordered within 24 h. 70% of the investigated clinical chemistry and 60% of coagulation tests were re-ordered one week after cancellation or not at all. Survey participants quite accurately estimated these numbers. Routine laboratory panels, short stay of out-patients, obsolete test results and avoiding additional phlebotomies were the main reasons for not re-ordering cancelled tests. Overall, 60-70% of test results in the investigated assays ordered in a high throughput laboratory are potentially inappropriate or of doubtful clinically importance. Although clinicians and nurses are aware of this situation, it is the duty of laboratory specialists to overcome overutilization in close collaboration with all involved healthcare workers. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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Zakaria, Rosita; Allen, Katrina J.; Koplin, Jennifer J.; Roche, Peter
2016-01-01
Introduction Through the introduction of advanced analytical techniques and improved throughput, the scope of dried blood spot testing utilising mass spectrometric methods, has broadly expanded. Clinicians and researchers have become very enthusiastic about the potential applications of dried blood spot based mass spectrometric applications. Analysts on the other hand face challenges of sensitivity, reproducibility and overall accuracy of dried blood spot quantification. In this review, we aim to bring together these two facets to discuss the advantages and current challenges of non-newborn screening applications of dried blood spot quantification by mass spectrometry. Methods To address these aims we performed a key word search of the PubMed and MEDLINE online databases in conjunction with individual manual searches to gather information. Keywords for the initial search included; “blood spot” and “mass spectrometry”; while excluding “newborn”; and “neonate”. In addition, databases were restricted to English language and human specific. There was no time period limit applied. Results As a result of these selection criteria, 194 references were identified for review. For presentation, this information is divided into: 1) clinical applications; and 2) analytical considerations across the total testing process; being pre-analytical, analytical and post-analytical considerations. Conclusions DBS analysis using MS applications is now broadly applied, with drug monitoring for both therapeutic and toxicological analysis being the most extensively reported. Several parameters can affect the accuracy of DBS measurement and further bridge experiments are required to develop adjustment rules for comparability between dried blood spot measures and the equivalent serum/plasma values. Likewise, the establishment of independent reference intervals for dried blood spot sample matrix is required. PMID:28149263
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Aulbach, Adam D; Schultze, Eric; Tripathi, Niraj K; Hall, Robert L; Logan, Michael R; Meyer, Denny J
2015-06-01
Urinalysis data in preclinical toxicology studies can be influenced by preanalytic and analytic factors which have the potential to confound interpretation. There is a paucity of information regarding positive reagent strip urinary blood reactions in healthy nonhuman primates (NHP) and Beagle dogs used in preclinical toxicology studies. The objectives were (1) to establish historical control data for reagent strip urinary blood reactions in healthy NHP and Beagle dogs, (2) to determine the incidence of positive urinary blood reactions during predose and dosing phases, and (3) to determine if collection practice was a relevant parameter. Historical control data from 2 institutions in the biopharmaceutical industry were retrospectively analyzed for reagent strip urinary blood reactions in healthy NHP and Beagles. The incidence of positive results between the 2 institutions with different urine collection practices and between males and females was compared. The incidence of positive urinary blood reactions in NHP was comparable between institutions (≤ 14% in males; ≤ 33% in females), while the incidence of positive urinary blood reactions in Beagles was more variable (≤ 77% in males; ≤ 69% in females), and higher in females during the dosing phase. Positive urinary blood results that could potentially be misinterpreted as toxicologically relevant were identified in healthy NHP and Beagles during predose and dosing phases. Different incidences of positive results between the 2 institutions were likely related to collection practices. Strategies to reduce feces and food contamination of collected urine samples should help minimize false-positive urinary blood reactions. © 2015 American Society for Veterinary Clinical Pathology.
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Oikonomidis, Ioannis L; Kiosis, Evangelos A; Brozos, Christos N; Kritsepi-Konstantinou, Maria G
2017-03-01
OBJECTIVE To establish reference intervals for serum reactive oxygen metabolites (ROMs), biological antioxidant potential (BAP), and oxidative stress index (OSi) in adult rams by use of controlled preanalytic and analytic procedures. ANIMALS 123 healthy 1- to 4-year-old rams of 2 Greek breeds (Chios [n = 62] and Florina [61]). PROCEDURES 4 hours after rams were fed, a blood sample was obtained from each ram, and serum was harvested. Concentrations of ROMs and BAP were measured colorimetrically on a spectrophotometric analyzer. The OSi was calculated as ROMs concentration divided by BAP concentration. Combined and breed-specific reference intervals were calculated by use of nonparametric and robust methods, respectively. Reference intervals were defined as the 2.5th to 97.5th percentiles. RESULTS Reference intervals for ROMs, BAP, and OSi for all rams combined were 65 to 109 Carratelli units, 2,364 to 4,491 μmol/L, and 18.2 to 43.0 Carratelli units/(mmol/L), respectively. Reference intervals of Chios rams for ROMs, BAP, and OSi were 56 to 113 Carratelli units, 2,234 to 4,290 μmol/L, and 12.9 to 38.4 Carratelli units/(mmol/L), respectively. Reference intervals of Florina rams for ROMs, BAP, and OSi were 68 to 111 Carratelli units, 2,337 to 4,363 μmol/L, and 14.1 to 38.1 Carratelli units/(mmol/L), respectively. CONCLUSIONS AND CLINICAL RELEVANCE Reference intervals calculated in this study can be used as a guide for the interpretation of ROMs, BAP, and OSi results in rams and, under appropriate conditions, can be adopted for use by veterinary laboratories.
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Bowen, Raffick A R; Adcock, Dorothy M
2016-12-01
Blood collection tubes (BCTs) are an often under-recognized variable in the preanalytical phase of clinical laboratory testing. Unfortunately, even the best-designed and manufactured BCTs may not work well in all clinical settings. Clinical laboratories, in collaboration with healthcare providers, should carefully evaluate BCTs prior to putting them into clinical use to determine their limitations and ensure that patients are not placed at risk because of inaccuracies due to poor tube performance. Selection of the best BCTs can be achieved through comparing advertising materials, reviewing the literature, observing the device at a scientific meeting, receiving a demonstration, evaluating the device under simulated conditions, or testing the device with patient samples. Although many publications have discussed method validations, few detail how to perform experiments for tube verification and validation. This article highlights the most common and impactful variables related to BCTs and discusses the validation studies that a typical clinical laboratory should perform when selecting BCTs. We also present a brief review of how in vitro diagnostic devices, particularly BCTs, are regulated in the United States, the European Union, and Canada. The verification and validation of BCTs will help to avoid the economic and human costs associated with incorrect test results, including poor patient care, unnecessary testing, and delays in test results. We urge laboratorians, tube manufacturers, diagnostic companies, and other researchers to take all the necessary steps to protect against the adverse effects of BCT components and their additives on clinical assays. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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Han, Jun; Tschernutter, Vera; Yang, Juncong; Eckle, Tobias; Borchers, Christoph H
2013-06-18
Sensitive and reliable analysis of sugars and sugar phosphates in tissues and cells is essential for many biological and cell engineering studies. However, the successful analysis of these endogenous compounds in biological samples by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) is often difficult because of their poor chromatographic retention properties in reversed-phase LC, the complex biological matrices, and the ionization suppression in ESI. This situation is further complicated by the existence of their multiple structural isomers in vivo. This work describes the combination of reductive amination using 3-amino-9-ethylcarbazole, with a new LC approach using a pentafluorophenyl core-shell ultrahigh performance (UP) LC column and methylphosphonic acid as an efficient tail-sweeping reagent for improved chromatographic separation. This new method was used for selected detection and accurate quantitation of the major free and phosphorylated reducing sugars in mouse heart tissue. Among the detected compounds, accurate quantitation of glyceraldehyde, ribose, glucose, glycerylaldehyde-3-phosphate, ribose-5-phosphate, glucose-6-phosphate, and mannose-6-phosphate was achieved by UPLC/multiple-reaction monitoring (MRM)-MS, with analytical accuracies ranging from 87.4% to 109.4% and CVs of ≤8.5% (n = 6). To demonstrate isotope-resolved metabolic profiling, we used UPLC/quadrupole time-of-flight (QTOF)-MS to analyze the isotope distribution patterns of C3 to C6 free and phosphorylated reducing sugars in heart tissues from (13)C-labeled wild type and knockout mice. In conclusion, the preanalytical derivatization-LC/ESI-MS method has resulted in selective determination of free and phosphorylated reducing sugars without the interferences from their nonreducing structural isomers in mouse heart tissue, with analytical sensitivities in the femtomole to low picomole range.
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Validation of α-Synuclein as a CSF Biomarker for Sporadic Creutzfeldt-Jakob Disease.
Llorens, Franc; Kruse, Niels; Karch, André; Schmitz, Matthias; Zafar, Saima; Gotzmann, Nadine; Sun, Ting; Köchy, Silja; Knipper, Tobias; Cramm, Maria; Golanska, Ewa; Sikorska, Beata; Liberski, Pawel P; Sánchez-Valle, Raquel; Fischer, Andre; Mollenhauer, Brit; Zerr, Inga
2018-03-01
The analysis of cerebrospinal fluid (CSF) biomarkers gains importance in the differential diagnosis of prion diseases. However, no single diagnostic tool or combination of them can unequivocally confirm prion disease diagnosis. Electrochemiluminescence (ECL)-based immunoassays have demonstrated to achieve high diagnostic accuracy in a variety of sample types due to their high sensitivity and dynamic range. Quantification of CSF α-synuclein (a-syn) by an in-house ECL-based ELISA assay has been recently reported as an excellent approach for the diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD), the most prevalent form of human prion disease. In the present study, we validated a commercially available ECL-based a-syn ELISA platform as a diagnostic test for correct classification of sCJD cases. CSF a-syn was analysed in 203 sCJD cases with definite diagnosis and in 445 non-CJD cases. We investigated reproducibility and stability of CSF a-syn and made recommendations for its analysis in the sCJD diagnostic workup. A sensitivity of 98% and a specificity of 97% were achieved when using an optimal cut-off of 820 pg/mL a-syn. Moreover, we were able to show a negative correlation between a-syn levels and disease duration suggesting that CSF a-syn may be a good prognostic marker for sCJD patients. The present study validates the use of a-syn as a CSF biomarker of sCJD and establishes the clinical and pre-analytical parameters for its use in differential diagnosis in clinical routine. Additionally, the current test presents some advantages compared to other diagnostic approaches: it is fast, economic, requires minimal amount of CSF and a-syn levels are stable along disease progression.
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Carter, Jamal; Miller, James Adam; Feller-Kopman, David; Ettinger, David; Sidransky, David; Maleki, Zahra
2017-07-01
Non-small-cell lung cancer (NSCLC)-associated malignant pleural effusions (MPEs) are sometimes the only available specimens for molecular analysis. This study evaluates diagnostic yield of NSCLC-associated MPE, its adequacy for molecular profiling and the potential influence of MPE volume/cellularity on the analytic sensitivity of our assays. Molecular results of 50 NSCLC-associated MPE cases during a 5-year period were evaluated. Molecular profiling was performed on cell blocks and consisted of fluorescent in situ hybridization (FISH) for ALK gene rearrangements and the following sequencing platforms: Sanger sequencing (for EGFR) and high-throughput pyrosequencing (for KRAS and BRAF) during the first 4 years of the study period, and targeted next-generation sequencing performed thereafter. A total of 50 NSCLC-associated MPE cases were identified where molecular testing was requested. Of these, 17 cases were excluded: 14 cases (28%) due to inadequate tumor cellularity and 3 cases due to unavailability of the slides to review. A total of 27 out of 50 MPE cases (54%) underwent at least EGFR and KRAS sequencing and FISH for ALK rearrangement. Of the 27 cases with molecular testing results available, a genetic abnormality was detected in 16 cases (59%). The most common genetic aberrations identified involved EGFR ( 9 ) and KRAS ( 7 ). Six cases had ALK FISH only, of which one showed rearrangement. MPE volume was not associated with overall cellularity or tumor cellularity (P = 0.360). Molecular profiling of MPE is a viable alternative to testing solid tissue in NSCLC. This study shows successful detection of genetic aberrations in 59% of samples with minimal risk of false negative.
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Evaluation of water-quality data and monitoring program for Lake Travis, near Austin, Texas
Rast, Walter; Slade, Raymond M.
1998-01-01
The multiple-comparison tests indicate that, for some constituents, a single sampling site for a constituent or property might adequately characterize the water quality of Lake Travis for that constituent or property. However, multiple sampling sites are required to provide information of sufficient temporal and spatial resolution to accurately evaluate other water-quality constituents for the reservoir. For example, the water-quality data from surface samples and from bottom samples indicate that nutrients (nitrogen, phosphorus) might require additional sampling sites for a more accurate characterization of their in-lake dynamics.
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Sakundarno, Mateus; Nurjazuli, Nurjazuli; Jati, Sutopo Patria; Sariningdyah, Retna; Purwadi, Sumarsono; Alisjahbana, Bachti; van der Werf, Marieke J
2009-01-01
Background Sputum smear microscopy is the standard diagnostic method for detection of smear positive pulmonary tuberculosis (TB). Insufficient quality of sputum might result in missing cases. In this study we aimed at assessing the quality of sputum in a district in Central Java and determining patient and health worker factors associated with submission of three good quality sputum samples. Methods In 16 health centers information was collected on the quality of sputum submitted by TB suspects, i.e. volume, color, and viscosity. TB suspects were interviewed to assess their knowledge of TB, motivation to provide sputum and whether they were informed why and how to produce a sputum sample. Health workers were interviewed to assess what information they provided to TB suspects about the reason for sputum examination, methods to produce sputum and characteristics of a good quality sputum sample. All health worker and patient factors were evaluated for association with sputum quality. Results Of 387 TB suspects, 294 (76.0%) could be traced and interviewed, and of 272 (70.3%) information about sputum quality was available. Of those 203 (74.6%) submitted three samples, 90 (33.1%) provided at least one good sample, and 37 (13.6%) provided three good quality sputum samples. Of the 272 TB suspects, 168 (61.8%) mentioned that information on the reason for sputum examination was provided, 66 (24.3%) remembered that they were informed about how to produce sputum and 40 (14.7%) recalled being informed about the characteristics of good quality sputum. Paramedics reported to provide often/always information on the importance of sputum examination, and when to produce sputum. Information on how to produce sputum and characteristics of a good sputum sample was less often provided. None of the studied patient characteristics or health worker factors was associated with providing good quality sputum. Conclusion A considerable number of TB suspects did not provide three sputum samples and a large number of sputum samples were of insufficient quality. Training of health workers in providing health education to the TB suspect about the reason for sputum examination and how to produce a good quality sputum sample should be a priority of the TB program. PMID:19426477
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Impact of sampling techniques on measured stormwater quality data for small streams
USDA-ARS?s Scientific Manuscript database
Science-based sampling methodologies are needed to enhance water quality characterization for developing Total Maximum Daily Loads (TMDLs), setting appropriate water quality standards, and managing nonpoint source pollution. Storm event sampling, which is vital for adequate assessment of water qual...
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Maloney, T.J.; Ludtke, A.S.; Krizman, T.L.
1994-01-01
The US. Geological Survey operates a quality- assurance program based on the analyses of reference samples for the National Water Quality Laboratory in Arvada, Colorado, and the Quality of Water Service Unit in Ocala, Florida. Reference samples containing selected inorganic, nutrient, and low ionic-strength constituents are prepared and disguised as routine samples. The program goal is to determine precision and bias for as many analytical methods offered by the participating laboratories as possible. The samples typically are submitted at a rate of approximately 5 percent of the annual environmental sample load for each constituent. The samples are distributed to the laboratories throughout the year. Analytical data for these reference samples reflect the quality of environmental sample data produced by the laboratories because the samples are processed in the same manner for all steps from sample login through data release. The results are stored permanently in the National Water Data Storage and Retrieval System. During water year 1991, 86 analytical procedures were evaluated at the National Water Quality Laboratory and 37 analytical procedures were evaluated at the Quality of Water Service Unit. An overall evaluation of the inorganic (major ion and trace metal) constituent data for water year 1991 indicated analytical imprecision in the National Water Quality Laboratory for 5 of 67 analytical procedures: aluminum (whole-water recoverable, atomic emission spectrometric, direct-current plasma); calcium (atomic emission spectrometric, direct); fluoride (ion-exchange chromatographic); iron (whole-water recoverable, atomic absorption spectrometric, direct); and sulfate (ion-exchange chromatographic). The results for 11 of 67 analytical procedures had positive or negative bias during water year 1991. Analytical imprecision was indicated in the determination of two of the five National Water Quality Laboratory nutrient constituents: orthophosphate as phosphorus and phosphorus. A negative or positive bias condition was indicated in three of five nutrient constituents. There was acceptable precision and no indication of bias for the 14 low ionic-strength analytical procedures tested in the National Water Quality Laboratory program and for the 32 inorganic and 5 nutrient analytical procedures tested in the Quality of Water Service Unit during water year 1991.
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Liang, Wenyi; Chen, Wenjing; Wu, Lingfang; Li, Shi; Qi, Qi; Cui, Yaping; Liang, Linjin; Ye, Ting; Zhang, Lanzhen
2017-03-17
Danshen, the dried root of Salvia miltiorrhiza Bge., is a widely used commercially available herbal drug, and unstable quality of different samples is a current issue. This study focused on a comprehensive and systematic method combining fingerprints and chemical identification with chemometrics for discrimination and quality assessment of Danshen samples. Twenty-five samples were analyzed by HPLC-PAD and HPLC-MS n . Forty-nine components were identified and characteristic fragmentation regularities were summarized for further interpretation of bioactive components. Chemometric analysis was employed to differentiate samples and clarify the quality differences of Danshen including hierarchical cluster analysis, principal component analysis, and partial least squares discriminant analysis. Consistent results were that the samples were divided into three categories which reflected the difference in quality of Danshen samples. By analyzing the reasons for sample classification, it was revealed that the processing method had a more obvious impact on sample classification than the geographical origin, it induced the different content of bioactive compounds and finally lead to different qualities. Cryptotanshinone, trijuganone B, and 15,16-dihydrotanshinone I were screened out as markers to distinguish samples by different processing methods. The developed strategy could provide a reference for evaluation and discrimination of other traditional herbal medicines.
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Calculating cost savings in utilization management.
MacMillan, Donna
2014-01-01
A major motivation for managing the utilization of laboratory testing is to reduce the cost of medical care. For this reason it is important to understand the basic principles of cost accounting in the clinical laboratory. The process of laboratory testing includes three distinct components termed the pre-analytic, analytic and post-analytic phases. Utilization management efforts may impact the cost structure of these three phases in different ways depending on the specific details of the initiative. Estimates of cost savings resulting from utilization management programs reported in the literature have often been fundamentally flawed due to a failure to understand basic concepts such as the difference between laboratory costs versus charges and the impact of reducing laboratory test volumes on the average versus marginal cost structure in the laboratory. This article will provide an overview of basic cost accounting principles in the clinical laboratory including both job order and process cost accounting. Specific examples will be presented to illustrate these concepts in various different scenarios. © 2013.
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Ki67 and proliferation in breast cancer.
Pathmanathan, Nirmala; Balleine, Rosemary L
2013-06-01
New approaches to the prognostic assessment of breast cancer have come from molecular profiling studies. A major feature of this work has been to emphasise the importance of cancer cell proliferation as a key discriminative indicator of recurrence risk for oestrogen receptor positive breast cancer in particular. Mitotic count scoring, as a component of histopathological grade, has long formed part of a routine evaluation of breast cancer biology. However, there is an increasingly compelling case to include a specific proliferation score in breast cancer pathology reports based on expression of the cell cycle regulated protein Ki67. Immunohistochemical staining for Ki67 is a widely available and economical test with good tolerance of pre-analytical variations and staining conditions. However, there is currently no evidence based protocol established to derive a reliable and informative Ki67 score for routine clinical use. In this circumstance, pathologists must establish a standardised framework for scoring Ki67 and communicating results to a multidisciplinary team.
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Technical variables in high-throughput miRNA expression profiling: much work remains to be done.
Nelson, Peter T; Wang, Wang-Xia; Wilfred, Bernard R; Tang, Guiliang
2008-11-01
MicroRNA (miRNA) gene expression profiling has provided important insights into plant and animal biology. However, there has not been ample published work about pitfalls associated with technical parameters in miRNA gene expression profiling. One source of pertinent information about technical variables in gene expression profiling is the separate and more well-established literature regarding mRNA expression profiling. However, many aspects of miRNA biochemistry are unique. For example, the cellular processing and compartmentation of miRNAs, the differential stability of specific miRNAs, and aspects of global miRNA expression regulation require specific consideration. Additional possible sources of systematic bias in miRNA expression studies include the differential impact of pre-analytical variables, substrate specificity of nucleic acid processing enzymes used in labeling and amplification, and issues regarding new miRNA discovery and annotation. We conclude that greater focus on technical parameters is required to bolster the validity, reliability, and cultural credibility of miRNA gene expression profiling studies.
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Ethics in the laboratory examination of patients
Nyrhinen, T.; Leino-Kilpi, H.
2000-01-01
Various value problems are connected with the clinical examination of patients. The purpose of this literature review is to clarify: 1) in which patient examinations ethical problems are generally found; 2) what kind of ethical problems are found in the different phases of the examination process, and 3) what kind of ethical problems are found in connection with the use of examination results. Genetic testing, autopsy, prenatal and HIV examinations were ethically the most problematic laboratory examinations. The most problematic phase in the laboratory examination process proved to be the pre-analytic phase. At present the results of laboratory examination are used more and more often for the prediction of diseases. The problems appear when the examination results are used for discrimination and stigmatisation. Because of the lack of empirical ethical research, it is important to chart empirical knowledge about present value conflict situations involved in the laboratory examination process. Key Words: Ethic • laboratory • test • examination • diagnosis • patient PMID:10701173
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Platelet Function Analyzed by Light Transmission Aggregometry.
Hvas, Anne-Mette; Favaloro, Emmanuel J
2017-01-01
Analysis of platelet function is widely used for diagnostic work-up in patients with increased bleeding tendency. During the last decades, platelet function testing has also been introduced for evaluation of antiplatelet therapy, but this is still recommended for research purposes only. Platelet function can also be assessed for hyper-aggregability, but this is less often evaluated. Light transmission aggregometry (LTA) was introduced in the early 1960s and has since been considered the gold standard. This optical detection system is based on changes in turbidity measured as a change in light transmission, which is proportional to the extent of platelet aggregation induced by addition of an agonist. LTA is a flexible method, as different agonists can be used in varying concentrations, but performance of the test requires large blood volumes and experienced laboratory technicians as well as specialized personal to interpret results. In the present chapter, a protocol for LTA is described including all steps from pre-analytical preparation to interpretation of results.
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What Is New in Clinical Microbiology—Microbial Identification by MALDI-TOF Mass Spectrometry
Murray, Patrick R.
2012-01-01
Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) offers the possibility of accurate, rapid, inexpensive identification of bacteria, fungi, and mycobacteria isolated in clinical microbiology laboratories. The procedures for preanalytic processing of organisms and analysis by MALDI-TOF MS are technically simple and reproducible, and commercial databases and interpretive algorithms are available for the identification of a wide spectrum of clinically significant organisms. Although only limited work has been reported on the use of this technique to identify molds, perform strain typing, or determine antibiotic susceptibility results, these are fruitful areas of promising research. As experience is gained with MALDI-TOF MS, it is expected that the databases will be expanded to resolve many of the current inadequate identifications (eg, no identification, genus-level identification) and algorithms for potential misidentification will be developed. The current lack of Food and Drug Administration approval of any MALDI-TOF MS system for organism identification limits widespread use in the United States. PMID:22795961
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Continuous-flow automation and hemolysis index: a crucial combination.
Lippi, Giuseppe; Plebani, Mario
2013-04-01
A paradigm shift has occurred in the role and organization of laboratory diagnostics over the past decades, wherein consolidation or networking of small laboratories into larger factories and point-of-care testing have simultaneously evolved and now seem to favorably coexist. There is now evidence, however, that the growing implementation of continuous-flow automation, especially in closed systems, has not eased the identification of hemolyzed specimens since the integration of preanalytical and analytical workstations would hide them from visual scrutiny, with an inherent risk that unreliable test results may be released to the stakeholders. Along with other technical breakthroughs, the new generation of laboratory instrumentation is increasingly equipped with systems that can systematically and automatically be tested for a broad series of interferences, the so-called serum indices, which also include the hemolysis index. The routine implementation of these technical tools in clinical laboratories equipped with continuous-flow automation carries several advantages and some drawbacks that are discussed in this article.
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The future of blood-based biomarkers for Alzheimer’s disease
Henriksen, Kim; O’Bryant, Sid E.; Hampel, Harald; Trojanowski, John Q.; Montine, Thomas J.; Jeromin, Andreas; Blennow, Kaj; Lönneborg, Anders; Wyss-Coray, Tony; Soares, Holly; Bazenet, Chantal; Sjögren, Magnus; Hu, William; Lovestone, Simon; Karsdal, Morten A.; Weiner, Michael W.
2014-01-01
Treatment of Alzheimer’s disease (AD) is significantly hampered by the lack of easily accessible biomarkers that can detect disease presence and predict disease risk reliably. Fluid biomarkers of AD currently provide indications of disease stage; however, they are not robust predictors of disease progression or treatment response, and most are measured in cerebrospinal fluid, which limits their applicability. With these aspects in mind, the aim of this article is to underscore the concerted efforts of the Blood-Based Biomarker Interest Group, an international working group of experts in the field. The points addressed include: (1) the major challenges in the development of blood-based biomarkers of AD, including patient heterogeneity, inclusion of the “right” control population, and the blood– brain barrier; (2) the need for a clear definition of the purpose of the individual markers (e.g., prognostic, diagnostic, or monitoring therapeutic efficacy); (3) a critical evaluation of the ongoing biomarker approaches; and (4) highlighting the need for standardization of preanalytical variables and analytical methodologies used by the field. PMID:23850333
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Evidence-based best practices for EGFR T790M testing in lung cancer in Canada.
Stockley, T; Souza, C A; Cheema, P K; Melosky, B; Kamel-Reid, S; Tsao, M S; Spatz, A; Karsan, A
2018-04-01
Epidermal growth factor receptor (egfr) tyrosine kinase inhibitors (tkis) are recommended as first-line systemic therapy for patients with non-small-cell lung cancer (nsclc) having mutations in the EGFR gene. Resistance to tkis eventually occurs in all nsclc patients treated with such drugs. In patients with resistance to tkis caused by the EGFR T790M mutation, the third-generation tki osimertinib is now the standard of care. For optimal patient management, accurate EGFR T790M testing is required. A multidisciplinary working group of pathologists, laboratory medicine specialists, medical oncologists, a respirologist, and a thoracic radiologist from across Canada was convened to discuss best practices for EGFR T790M mutation testing in Canada. The group made recommendations in the areas of the testing algorithm and the pre-analytic, analytic, and post-analytic aspects of clinical testing for both tissue testing and liquid biopsy circulating tumour dna testing. The recommendations aim to improve EGFR T790M testing in Canada and to thereby improve patient care.
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[MALDI-TOF mass spectrometry: Evaluation of the preanalytical phase for identification of molds].
Maldonado, Ivana; García Ramírez, Dolores; Striebeck, Pablo; Lafage, Marcelo; Fernández Canigia, Liliana
In order to optimize the identification of molds with MALDI-TOF MS, three protein extraction-methodologies were evaluated against 44 isolates: water extraction (WE), zirconium extraction (ZE) and the provider's recommended method (PRM). Two data bases were compared, Bruker (BK) and Bruker+National Institutes of Health. Considering both databases, results were respectively as follows: correct identification (CI) at gender level, 10 and 16 by WE; 27 and 32 by ZE and 18 and 23 by PRM; CI at species level, 5 and 7 by WE; 17 and 20 by ZE and 11 and 14 by PRM; non-reliable identification, 18 and 12 by WE; 9 and 4 by ZE and by PRM. No peaks were observed in 16 by WE, 8 by ZE and 17 by PRM. ZE showed the best perfomance (p<0.05). Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.
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Kap, Marcel; Oomen, Monique; Arshad, Shazia; de Jong, Bas; Riegman, Peter
2014-04-01
About 5000 frozen tissue samples are collected each year by the Erasmus Medical Center tissue bank. Two percent of these samples are randomly selected annually for RNA isolation and RNA Integrity Number (RIN) measurement. A similar quality assessment was conducted during centralization of a 20-year-old tissue collection from the cancer institute, a 15-year-old liver sample archive (-80°C), and a 13-year-old clinical pathology frozen biopsy archive (Liquid Nitrogen). Samples were divided into either high-quality (RIN ≥6.5) or low-quality overall categories, or into four "fit-for-purpose" quality groups: RIN <5: not reliable for demanding downstream analysis; 5 ≤RIN <6: suitable for RT-qPCR; 6 ≤RIN <8: suitable for gene array analysis; and RIN ≥8: suitable for all downstream techniques. In general, low RIN values were correlated with fatty, fibrous, pancreatic, or necrotic tissue. When the percentage of samples with RIN ≥6.5 is higher than 90%, the tissue bank performance is adequate. The annual 2011 quality control assessment showed that 90.3% (n=93) of all samples had acceptable RIN values; 97.4% (n=39) of the cancer institute collection had RIN values above 6.5; and 88.6% (n=123) of samples from the liver sample archive collection had RIN values higher than 6.5. As the clinical pathology biopsy collection contained only 58.8% (n=24) acceptable samples, the procurement protocols used for these samples needed immediate evaluation. When the distribution of RIN values of the different collections were compared, no significant differences were found, despite differences in average storage time and temperature. According to the principle of "fit-for-purpose" distribution, the vast majority of samples are considered good enough for most downstream techniques. In conclusion, an annual tissue bank quality control procedure provides useful information on tissue sample quality and sheds light on where and if improvements need to be made.
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Kaur, Harparkash; Allan, Elizabeth Louise; Mamadu, Ibrahim; Hall, Zoe; Ibe, Ogochukwu; El Sherbiny, Mohamed; van Wyk, Albert; Yeung, Shunmay; Swamidoss, Isabel; Green, Michael D.; Dwivedi, Prabha; Culzoni, Maria Julia; Clarke, Siân; Schellenberg, David; Fernández, Facundo M.; Onwujekwe, Obinna
2015-01-01
Background Artemisinin-based combination therapies are recommended by the World Health Organisation (WHO) as first-line treatment for Plasmodium falciparum malaria, yet medication must be of good quality for efficacious treatment. A recent meta-analysis reported 35% (796/2,296) of antimalarial drug samples from 21 Sub-Saharan African countries, purchased from outlets predominantly using convenience sampling, failed chemical content analysis. We used three sampling strategies to purchase artemisinin-containing antimalarials (ACAs) in Enugu metropolis, Nigeria, and compared the resulting quality estimates. Methods ACAs were purchased using three sampling approaches - convenience, mystery clients and overt, within a defined area and sampling frame in Enugu metropolis. The active pharmaceutical ingredients were assessed using high-performance liquid chromatography and confirmed by mass spectrometry at three independent laboratories. Results were expressed as percentage of APIs stated on the packaging and used to categorise each sample as acceptable quality, substandard, degraded, or falsified. Results Content analysis of 3024 samples purchased from 421 outlets using convenience (n=200), mystery (n=1,919) and overt (n=905) approaches, showed overall 90.8% ACAs to be of acceptable quality, 6.8% substandard, 1.3% degraded and 1.2% falsified. Convenience sampling yielded a significantly higher prevalence of poor quality ACAs, but was not evident by the mystery and overt sampling strategies both of which yielded results that were comparable between each other. Artesunate (n=135; 4 falsified) and dihydroartemisinin (n=14) monotherapy tablets, not recommended by WHO, were also identified. Conclusion Randomised sampling identified fewer falsified ACAs than previously reported by convenience approaches. Our findings emphasise the need for specific consideration to be given to sampling frame and sampling approach if representative information on drug quality is to be obtained. PMID:26018221
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Young, Stacie T.M.; Ball, Marcael T.J.
2004-01-01
Storm runoff water-quality samples were collected as part of the State of Hawaii Department of Transportation Stormwater Monitoring Program. This program is designed to assess the effects of highway runoff and urban runoff on Halawa Stream. For this program, rainfall data were collected at two sites, continuous streamflow data at three sites, and water-quality data at five sites, which include the three streamflow sites. This report summarizes rainfall, streamflow, and water-quality data collected between July 1, 2003 and June 30, 2004. A total of 30 samples was collected over four storms during July 1, 2003 to June 30, 2004. In general, an attempt was made to collect grab samples nearly simultaneously at all five sites, and flow-weighted time-composite samples were collected at the three sites equipped with automatic samplers. However, all four storms were partially sampled because either not all stations were sampled or only grab samples were collected. Samples were analyzed for total suspended solids, total dissolved solids, nutrients, chemical oxygen demand, and selected trace metals (cadmium, copper, lead, and zinc). Grab samples were additionally analyzed for oil and grease, total petroleum hydrocarbons, fecal coliform, and biological oxygen demand. Quality-assurance/quality-control samples, collected during storms and during routine maintenance, were also collected to verify analytical procedures and check the effectiveness of equipment-cleaning procedures.
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Evaluating Quality of Aged Archival Formalin-Fixed Paraffin-Embedded Samples for RNA-Sequencing
Archival formalin-fixed paraffin-embedded (FFPE) samples offer a vast, untapped source of genomic data for biomarker discovery. However, the quality of FFPE samples is often highly variable, and conventional methods to assess RNA quality for RNA-sequencing (RNA-seq) are not infor...
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2013-01-01
Background Traditional Lot Quality Assurance Sampling (LQAS) designs assume observations are collected using simple random sampling. Alternatively, randomly sampling clusters of observations and then individuals within clusters reduces costs but decreases the precision of the classifications. In this paper, we develop a general framework for designing the cluster(C)-LQAS system and illustrate the method with the design of data quality assessments for the community health worker program in Rwanda. Results To determine sample size and decision rules for C-LQAS, we use the beta-binomial distribution to account for inflated risk of errors introduced by sampling clusters at the first stage. We present general theory and code for sample size calculations. The C-LQAS sample sizes provided in this paper constrain misclassification risks below user-specified limits. Multiple C-LQAS systems meet the specified risk requirements, but numerous considerations, including per-cluster versus per-individual sampling costs, help identify optimal systems for distinct applications. Conclusions We show the utility of C-LQAS for data quality assessments, but the method generalizes to numerous applications. This paper provides the necessary technical detail and supplemental code to support the design of C-LQAS for specific programs. PMID:24160725
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Hedt-Gauthier, Bethany L; Mitsunaga, Tisha; Hund, Lauren; Olives, Casey; Pagano, Marcello
2013-10-26
Traditional Lot Quality Assurance Sampling (LQAS) designs assume observations are collected using simple random sampling. Alternatively, randomly sampling clusters of observations and then individuals within clusters reduces costs but decreases the precision of the classifications. In this paper, we develop a general framework for designing the cluster(C)-LQAS system and illustrate the method with the design of data quality assessments for the community health worker program in Rwanda. To determine sample size and decision rules for C-LQAS, we use the beta-binomial distribution to account for inflated risk of errors introduced by sampling clusters at the first stage. We present general theory and code for sample size calculations.The C-LQAS sample sizes provided in this paper constrain misclassification risks below user-specified limits. Multiple C-LQAS systems meet the specified risk requirements, but numerous considerations, including per-cluster versus per-individual sampling costs, help identify optimal systems for distinct applications. We show the utility of C-LQAS for data quality assessments, but the method generalizes to numerous applications. This paper provides the necessary technical detail and supplemental code to support the design of C-LQAS for specific programs.
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Reflexion on linear regression trip production modelling method for ensuring good model quality
NASA Astrophysics Data System (ADS)
Suprayitno, Hitapriya; Ratnasari, Vita
2017-11-01
Transport Modelling is important. For certain cases, the conventional model still has to be used, in which having a good trip production model is capital. A good model can only be obtained from a good sample. Two of the basic principles of a good sampling is having a sample capable to represent the population characteristics and capable to produce an acceptable error at a certain confidence level. It seems that this principle is not yet quite understood and used in trip production modeling. Therefore, investigating the Trip Production Modelling practice in Indonesia and try to formulate a better modeling method for ensuring the Model Quality is necessary. This research result is presented as follows. Statistics knows a method to calculate span of prediction value at a certain confidence level for linear regression, which is called Confidence Interval of Predicted Value. The common modeling practice uses R2 as the principal quality measure, the sampling practice varies and not always conform to the sampling principles. An experiment indicates that small sample is already capable to give excellent R2 value and sample composition can significantly change the model. Hence, good R2 value, in fact, does not always mean good model quality. These lead to three basic ideas for ensuring good model quality, i.e. reformulating quality measure, calculation procedure, and sampling method. A quality measure is defined as having a good R2 value and a good Confidence Interval of Predicted Value. Calculation procedure must incorporate statistical calculation method and appropriate statistical tests needed. A good sampling method must incorporate random well distributed stratified sampling with a certain minimum number of samples. These three ideas need to be more developed and tested.
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Dodge, Kent A.; Hornberger, Michelle I.; Dyke, Jessica
2007-01-01
Water, bed sediment, and biota were sampled in streams from Butte to below Milltown Reservoir as part of a long-term monitoring program in the upper Clark Fork basin; additional water-quality samples were collected in the Clark Fork basin from sites near Milltown Reservoir downstream to near the confluence of the Clark Fork and Flathead River as part of a supplemental sampling program. The sampling programs were conducted in cooperation with the U.S. Environmental Protection Agency to characterize aquatic resources in the Clark Fork basin of western Montana, with emphasis on trace elements associated with historic mining and smelting activities. Sampling sites were located on the Clark Fork and selected tributaries. Water-quality samples were collected periodically at 22 sites from October 2005 through September 2006. Bed-sediment and biological samples were collected once at 12 sites during August 2006. This report presents the analytical results and quality-assurance data for water-quality, bed-sediment, and biota samples collected at all long-term and supplemental monitoring sites from October 2005 through September 2006. Water-quality data include concentrations of selected major ions, trace ele-ments, and suspended sediment. Nutrients also were analyzed in the supplemental water-quality samples. Daily values of suspended-sed-iment concentration and suspended-sediment discharge were determined for four sites, and seasonal daily values of turbidity were determined for four sites. Bed-sediment data include trace-ele-ment concentrations in the fine-grained fraction. Bio-logical data include trace-element concentrations in whole-body tissue of aquatic benthic insects. Statistical summaries of long-term water-quality, bed-sediment, and biological data for sites in the upper Clark Fork basin are provided for the period of record since 1985.
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Pieters, Marlien; Barnard, Sunelle A; Loots, Du Toit; Rijken, Dingeman C
2017-01-01
Due to controversial evidence in the literature pertaining to the activity of plasminogen activator inhibitor-1 in platelets, we examined the effects of residual platelets present in plasma (a potential pre-analytical variable) on various plasminogen activator inhibitor-1 and plasminogen activator inhibitor-1-related assays. Blood samples were collected from 151 individuals and centrifuged at 352 and 1500 g to obtain plasma with varying numbers of platelet. In a follow-up study, blood samples were collected from an additional 23 individuals, from whom platelet-poor (2000 g), platelet-containing (352 g) and platelet-rich plasma (200 g) were prepared and analysed as fresh-frozen and after five defrost-refreeze cycles (to determine the contribution of in vitro platelet degradation). Plasminogen activator inhibitor-1 activity, plasminogen activator inhibitor-1 antigen, tissue plasminogen activator/plasminogen activator inhibitor-1 complex, plasma clot lysis time, β-thromboglobulin and plasma platelet count were analysed. Platelet α-granule release (plasma β-thromboglobulin) showed a significant association with plasminogen activator inhibitor-1 antigen levels but weak associations with plasminogen activator inhibitor-1 activity and a functional marker of fibrinolysis, clot lysis time. Upon dividing the study population into quartiles based on β-thromboglobulin levels, plasminogen activator inhibitor-1 antigen increased significantly across the quartiles while plasminogen activator inhibitor-1 activity and clot lysis time tended to increase in the 4th quartile only. In the follow-up study, plasma plasminogen activator inhibitor-1 antigen was also significantly influenced by platelet count in a concentration-dependent manner. Plasma plasminogen activator inhibitor-1 antigen levels increased further after complete platelet degradation. Residual platelets in plasma significantly influence plasma plasminogen activator inhibitor-1 antigen levels mainly through release of latent plasminogen activator inhibitor-1 with limited effects on plasminogen activator inhibitor-1 activity, tissue plasminogen activator/plasminogen activator inhibitor-1 complex or plasma clot lysis time. Platelets may however also have functional effects on plasma fibrinolytic potential in the presence of high platelet counts, such as in platelet-rich plasma.