Targeting a genetic defect: cystic fibrosis transmembrane conductance regulator modulators in cystic fibrosis.

PubMed

Derichs, Nico

2013-03-01

Cystic fibrosis (CF) is caused by genetic mutations that affect the cystic fibrosis transmembrane conductance regulator (CFTR) protein. These mutations can impact the synthesis and transfer of the CFTR protein to the apical membrane of epithelial cells, as well as influencing the gating or conductance of chloride and bicarbonate ions through the channel. CFTR dysfunction results in ionic imbalance of epithelial secretions in several organ systems, such as the pancreas, gastrointestinal tract, liver and the respiratory system. Since discovery of the CFTR gene in 1989, research has focussed on targeting the underlying genetic defect to identify a disease-modifying treatment for CF. Investigated management strategies have included gene therapy and the development of small molecules that target CFTR mutations, known as CFTR modulators. CFTR modulators are typically identified by high-throughput screening assays, followed by preclinical validation using cell culture systems. Recently, one such modulator, the CFTR potentiator ivacaftor, was approved as an oral therapy for CF patients with the G551D-CFTR mutation. The clinical development of ivacaftor not only represents a breakthrough in CF care but also serves as a noteworthy example of personalised medicine.

mRNA-based detection of rare CFTR mutations improves genetic diagnosis of cystic fibrosis in populations with high genetic heterogeneity.

PubMed

Felício, V; Ramalho, A S; Igreja, S; Amaral, M D

2017-03-01

Even with advent of next generation sequencing complete sequencing of large disease-associated genes and intronic regions is economically not feasible. This is the case of cystic fibrosis transmembrane conductance regulator (CFTR), the gene responsible for cystic fibrosis (CF). Yet, to confirm a CF diagnosis, proof of CFTR dysfunction needs to be obtained, namely by the identification of two disease-causing mutations. Moreover, with the advent of mutation-based therapies, genotyping is an essential tool for CF disease management. There is, however, still an unmet need to genotype CF patients by fast, comprehensive and cost-effective approaches, especially in populations with high genetic heterogeneity (and low p.F508del incidence), where CF is now emerging with new diagnosis dilemmas (Brazil, Asia, etc). Herein, we report an innovative mRNA-based approach to identify CFTR mutations in the complete coding and intronic regions. We applied this protocol to genotype individuals with a suspicion of CF and only one or no CFTR mutations identified by routine methods. It successfully detected multiple intronic mutations unlikely to be detected by CFTR exon sequencing. We conclude that this is a rapid, robust and inexpensive method to detect any CFTR coding/intronic mutation (including rare ones) that can be easily used either as primary approach or after routine DNA analysis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cystic fibrosis transmembrane conductance regulator gene mutations: do they play a role in the aetiology of allergic bronchopulmonary aspergillosis?

PubMed

Eaton, T E; Weiner Miller, P; Garrett, J E; Cutting, G R

2002-05-01

Previous work suggests that cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations may be implicated in the aetiology of allergic bronchopulmonary aspergilosis (ABPA). To compare the frequency of CF gene mutations in asthmatics with ABPA of varying severity with asthmatics who were skin prick test (SPT)-positive to Aspergillus fumigatus (Af) without evidence of ABPA and asthmatics SPT-negative to Af. Thirty-one Caucasian patients with ABPA were identified, together with asthmatics SPT positive to Af without evidence of ABPA (n = 23) and SPT negative to Af (n = 28). Genomic DNA was tested for 16 CF mutations accounting for approximately 85% of CF alleles in Caucasian New Zealanders. Four (12.9%) ABPA patients were found to be carriers of a CF mutation (DeltaF508 n = 3, R117H n = 1), one (4.3%) asthmatic SPT positive to Af without ABPA (DeltaF508), and one (3.6%) asthmatic SPT negative to Af (R117H). All patients with a CF mutation had normal sweat chloride (< 40 mM). There was no significant difference between the frequency of CF mutations in the ABPA patients and asthmatics without ABPA. However, the frequency of CF mutations in the ABPA patients was significantly different (P = 0.0125) to the expected carrier rate in the general population. These results lend further support to a possible link between CF mutations and ABPA.

Cystic fibrosis transmembrane regulator haplotypes in households of patients with cystic fibrosis.

PubMed

Furgeri, Daniela Tenório; Marson, Fernando Augusto Lima; Correia, Cyntia Arivabeni Araújo; Ribeiro, José Dirceu; Bertuzzo, Carmen Sílvia

2018-01-30

Nearly 2000 mutations in the cystic fibrosis transmembrane regulator (CFTR) gene have been reported. The F508del mutation occurs in approximately 50-65% of patients with cystic fibrosis (CF). However, molecular diagnosis is not always possible. Therefore, silent polymorphisms can be used to label the mutant allele in households of patients with CF. To verify the haplotypes of four polymorphisms at the CFTR locus in households of patients with CF for pre-fertilization, pre-implantation, and prenatal indirect mutation diagnosis to provide better genetic counseling for families and patients with CF and to associate the genotypes/haplotypes with the F508del mutation screening. GATT polymorphism analysis was performed using direct polymerase chain reaction amplification, and the MP6-D9, TUB09 and TUB18 polymorphism analyses were performed using restriction fragment length polymorphism. Nine haplotypes were found in 37 CFTR alleles, and of those, 24 were linked with the F508del mutation and 13 with other CFTR mutations. The 6 (GATT), C (MP6-D9), G (TUB09), and C (TUB18) haplotypes showed the highest prevalence (48%) of the mutant CFTR allele and were linked to the F508del mutation (64%). In 43% of households analyzed, at least one informative polymorphism can be used for the indirect diagnostic test. CFTR polymorphisms are genetic markers that are useful for identifying the mutant CFTR alleles in households of patients with CF when it is not possible to establish the complete CFTR genotype. Moreover, the polymorphisms can be used for indirect CFTR mutation identification in cases of pre-fertilization, pre-implantation and prenatal analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Thymosin α1 represents a potential potent single-molecule-based therapy for cystic fibrosis.

PubMed

Romani, Luigina; Oikonomou, Vasilis; Moretti, Silvia; Iannitti, Rossana G; D'Adamo, Maria Cristina; Villella, Valeria R; Pariano, Marilena; Sforna, Luigi; Borghi, Monica; Bellet, Marina M; Fallarino, Francesca; Pallotta, Maria Teresa; Servillo, Giuseppe; Ferrari, Eleonora; Puccetti, Paolo; Kroemer, Guido; Pessia, Mauro; Maiuri, Luigi; Goldstein, Allan L; Garaci, Enrico

2017-05-01

Cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) that compromise its chloride channel activity. The most common mutation, p.Phe508del, results in the production of a misfolded CFTR protein, which has residual channel activity but is prematurely degraded. Because of the inherent complexity of the pathogenetic mechanisms involved in CF, which include impaired chloride permeability and persistent lung inflammation, a multidrug approach is required for efficacious CF therapy. To date, no individual drug with pleiotropic beneficial effects is available for CF. Here we report on the ability of thymosin alpha 1 (Tα1)-a naturally occurring polypeptide with an excellent safety profile in the clinic when used as an adjuvant or an immunotherapeutic agent-to rectify the multiple tissue defects in mice with CF as well as in cells from subjects with the p.Phe508del mutation. Tα1 displayed two combined properties that favorably opposed CF symptomatology: it reduced inflammation and increased CFTR maturation, stability and activity. By virtue of this two-pronged action, Tα1 has strong potential to be an efficacious single-molecule-based therapeutic agent for CF.

Thymosin α1 represents a potential potent single molecule-based therapy for cystic fibrosis

PubMed Central

Romani, Luigina; Oikonomou, Vasilis; Moretti, Silvia; Iannitti, Rossana G.; D’Adamo, Maria Cristina; Villella, Valeria R.; Pariano, Marilena; Sforna, Luigi; Borghi, Monica; Bellet, Marina M.; Fallarino, Francesca; Pallotta, Maria Teresa; Servillo, Giuseppe; Ferrari, Eleonora; Puccetti, Paolo; Kroemer, Guido; Pessia, Mauro; Maiuri, Luigi; Goldstein, Allan L.; Garaci, Enrico

2017-01-01

Cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) that compromise its chloride-channel activity. The most common mutation, p.Phe508del, results in the production of a misfolded CFTR protein, which has residual channel activity but is prematurely degraded. Because of the inherent complexity of the pathogenetic mechanisms involved in CF —which include impaired chloride permeability and persistent lung inflammation—a multidrug approach is required for efficacious CF therapy. To date, no individual, drug with pleiotropic beneficial effects for CF is available. Here we report on the ability of thymosin alpha 1 (Tα1)—a naturally occurring polypeptide with an excellent safety profile in the clinic when used as an adjuvant or an immunotherapeutic agent—to rectify the multiple tissue defects in CF mice as well as in cells from subjects with the p.Phe508del mutation. Tα1 displayed two combined properties that favorably opposed CF symptomatology; namely, it reduced inflammation and increased CFTR maturation, stability and activity. By virtue of this two-pronged action, Tα1 offers a strong potential to be an efficacious single molecule-based therapeutic agent in CF. PMID:28394330

Molecular basis of cystic fibrosis in Lithuania: incomplete CFTR mutation detection by PCR-based screening protocols.

PubMed

Giannattasio, S; Bobba, A; Jurgelevicius, V; Vacca, R A; Lattanzio, P; Merafina, R S; Utkus, A; Kucinskas, V; Marra, E

2006-01-01

Mutational analysis of the cystic fibrosis transmembrane regulator (CFTR) gene was performed in 98 unrelated CF chromosomes from 49 Lithuanian CF patients through a combined approach in which the p.F508del mutation was first screened by allele-specific PCR while CFTR mutations in nonp.F508del chromosomes have been screened for by denaturing gradient gel electrophoresis analysis. A CFTR mutation was characterized in 62.2% of CF chromosomes, two of which (2.0%) have been previously shown to carry a large gene deletion CFTRdele2,3(21 kb). The most frequent Lithuanian CF mutation is p.F508del (52.0%). Seven CFTR mutations, p.N1303K (2.0%), p.R75Q (1.0%), p.G314R (1.0%), p.R553X (4.2%), p.W1282X (1.0%), and g.3944delGT (1.0%), accounted for 10.1% of Lithuanian CF chromosomes. It was not possible to characterize 35.8% of the CF Lithuanian chromosomes. Analysis of intron 8 (TG)mTn and M470V polymorphic loci did not permit the characterization of the CFTR dysfunction underlying the CF phenotype in the patients for which no CFTR mutation was identified. Thus, screening of the eight CFTR mutations identified in this study and of the large deletion CFTRdele2,3(21 kb) allows the implementation of an early molecular or confirmatory CF diagnosis for 65% of Lithuanian CF chromosomes.

Applying Cystic Fibrosis Transmembrane Conductance Regulator Genetics and CFTR2 Data to Facilitate Diagnoses.

PubMed

Sosnay, Patrick R; Salinas, Danieli B; White, Terry B; Ren, Clement L; Farrell, Philip M; Raraigh, Karen S; Girodon, Emmanuelle; Castellani, Carlo

2017-02-01

As a Mendelian disease, genetics plays an integral role in the diagnosis of cystic fibrosis (CF). The identification of 2 disease-causing mutations in the CF transmembrane conductance regulator (CFTR) in an individual with a phenotype provides evidence that the disease is CF. However, not all variations in CFTR always result in CF. Therefore, for CFTR genotype to provide the same level of evidence of CFTR dysfunction as shown by direct tests such as sweat chloride or nasal potential difference, the mutations identified must be known to always result in CF. The use of CFTR genetics in CF diagnosis, therefore, relies heavily on mutation interpretation. Progress that has been made on mutation interpretation and annotation was reviewed at the recent CF Foundation Diagnosis Consensus Conference. A modified Delphi method was used to identify consensus statements on the use of genetic analysis in CF diagnosis. The largest recent advance in CF genetics has come through the Clinical and Functional Translation of CFTR (CFTR2) project. This undertaking seeks to characterize CFTR mutations from patients with CF around the world. The project also established guidelines for the clinical, functional, and population/penetrance criteria that can be used to interpret mutations not yet included in CFTR2's review. The use of CFTR genetics to aid in diagnosis of CF requires that the mutations identified have a known disease liability. The demonstration of 2 in trans mutations known to always result in CF is satisfactory evidence of CFTR dysfunction. However, if the identified mutations are known to be associated with variable outcomes, or have unknown consequence, that genotype may not result in a CF phenotype. In these cases, other tests of CFTR function may help. Copyright © 2016 Elsevier Inc. All rights reserved.

[Cystic fibrosis gene mutations in the West of France: clinical application].

PubMed

Verlingue, C; Travert, G; Le Roux, M G; Laroche, D; Audrézet, M P; Mercier, B; Moisan, J P; Férec, C

1994-01-01

The cystic fibrosis transmembrane conductance regulator (CFTR) gene, responsible for the cystic fibrosis phenotype when both alleles are mutated, was cloned and sequenced in 1989. Since then, more than 400 mutations have been reported in the gene, although most of these are rare. We have systematically analysed the entire coding sequence of the CFTR gene in a cohort of patients originating from the West of France (Caen, Brest and Nantes). More than 450 CF children, 914 chromosomes in all, have been exhaustively studied in the three centers. We have been able to characterize more than 90% of the mutations, respectively 93.5%, 99% and 95.8%. Despite the large diversity in the CFTR mutations occurring in CF patients from this area, these results can help to improve genetic counselling, prenatal diagnosis as well as our understanding of the molecular basis of the pathophysiology of cystic fibrosis.

Strategies for the etiological therapy of cystic fibrosis.

PubMed

Maiuri, Luigi; Raia, Valeria; Kroemer, Guido

2017-11-01

Etiological therapies aim at repairing the underlying cause of cystic fibrosis (CF), which is the functional defect of the cystic fibrosis transmembrane conductance regulator (CFTR) protein owing to mutations in the CFTR gene. Among these, the F508del CFTR mutation accounts for more than two thirds of CF cases worldwide. Two somehow antinomic schools of thought conceive CFTR repair in a different manner. According to one vision, drugs should directly target the mutated CFTR protein to increase its plasma membrane expression (correctors) or improve its ion transport function (potentiators). An alternative strategy consists in modulating the cellular environment and proteostasis networks in which the mutated CFTR protein is synthesized, traffics to its final destination, the plasma membrane, and is turned over. We will analyze distinctive advantages and drawbacks of these strategies in terms of their scientific and clinical dimensions, and we will propose a global strategy for CF research and development based on a reconciliatory approach. Moreover, we will discuss the utility of preclinical biomarkers that may guide the personalized, patient-specific implementation of CF therapies.

Strategies for the etiological therapy of cystic fibrosis

PubMed Central

Maiuri, Luigi; Raia, Valeria; Kroemer, Guido

2017-01-01

Etiological therapies aim at repairing the underlying cause of cystic fibrosis (CF), which is the functional defect of the cystic fibrosis transmembrane conductance regulator (CFTR) protein owing to mutations in the CFTR gene. Among these, the F508del CFTR mutation accounts for more than two thirds of CF cases worldwide. Two somehow antinomic schools of thought conceive CFTR repair in a different manner. According to one vision, drugs should directly target the mutated CFTR protein to increase its plasma membrane expression (correctors) or improve its ion transport function (potentiators). An alternative strategy consists in modulating the cellular environment and proteostasis networks in which the mutated CFTR protein is synthesized, traffics to its final destination, the plasma membrane, and is turned over. We will analyze distinctive advantages and drawbacks of these strategies in terms of their scientific and clinical dimensions, and we will propose a global strategy for CF research and development based on a reconciliatory approach. Moreover, we will discuss the utility of preclinical biomarkers that may guide the personalized, patient-specific implementation of CF therapies. PMID:28937684

Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in allergic bronchopulmonary aspergillosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, P.W.; Hamosh, A.; Macek, M. Jr.

The etiology of allergic bronchopulmonary aspergillosis (ABPA) is not well understood. A clinical phenotype resembling the pulmonary disease seen in cystic fibrosis (CF) patients can occur in some individuals with ABPA. Reports of familial occurrence of ABPA and increased incidence in CF patients suggest a possible genetic basis for the disease. To test this possibility, the entire coding region of the cystic fibrosis transmembrane regulator (CFTR) gene was analyzed in 11 individuals who met strict criteria for the diagnosis of ABPA and had normal sweat electrolytes ({le}40 mmol/liter). One patient carried two CF mutations ({Delta}F508/R347H), and five were found tomore » carry one CF mutation (four {Delta}F508; one R117H). The frequency of the {Delta}F508 mutation in patients with ABPA was significantly higher than in 53 Caucasian patients with chronic bronchitis (P < .0003) and the general population (P < .003). These results suggest that CFTR plays an etiologic role in a subset of ABPA patients. 54 refs., 2 tabs.« less

Cystic fibrosis screening using the College panel: platform comparison and lessons learned from the first 20,000 samples.

PubMed

Strom, Charles M; Huang, Donghui; Buller, Arlene; Redman, Joy; Crossley, Beryl; Anderson, Ben; Entwistle, Tom; Sun, Weimin

2002-01-01

To determine the accuracy of two commercially available kits for cystic fibrosis (CF) genotyping and determine allele frequencies for the ACMG/ACOG recommended mutations. A total of 1,040 consecutive analyses using Roche CF Gold Strips and the ABI CF Genotyper were performed. Subsequently we performed analyses of 20,103 samples. Both kits accurately determined CF genotypes. The I148T mutation was found >100 times more frequently in carrier screening than in CF patients. Asymptomatic patients were identified who are compound heterozygotes for delta F508 and I148T. Four of 13 patients heterozygous for delta F508 and the IVS8-5T polymorphism had some symptoms of CF. Accurate and timely analysis can be performed for the ACMG CF panel. I148T is a low penetrance CF allele.

Identification of mutations in regions corresponding to the two putative nucleotide (ATP)-binding folds of the cystic fibrosis gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerem, B.; Zielenski, J.; Markiewicz, D.

1990-11-01

Additional mutations in the cystic fibrosis (CF) gene were identified in the regions corresponding to the two putative nucleotide (ATP)-binding folds (NBFs) of the predicted polypeptide. The patient cohort included 46 Canadian CF families with well-characterized DNA marker haplotypes spanning the disease locus and several other families from Israel. Eleven mutations were found in the first NBF, 2 were found in the second NBF, but none was found in the R-domain. Seven of the mutations were of the missense type affecting some of the highly conserved amino acid residues in the first NBF; 3 were nonsense mutations; 2 would probablymore » affect mRNA splicing; 2 corresponded to small deletions, including another 3-base-pair deletion different from the major mutation ({delta}F508), which could account for 70% of the CF chromosomes in the population. Nine of these mutations accounted for 12 of the 31 non-{delta}F508 CF chromosomes in the Canadian families. The highly heterogeneous nature of the remaining CF mutations provides important insights into the structure and function of the protein, but it also suggests that DNA-based genetic screening for CF carrier status will not be straightforward.« less

An "ex vivo model" contributing to the diagnosis and evaluation of new drugs in cystic fibrosis.

PubMed

Di Lullo, A M; Scorza, M; Amato, F; Comegna, M; Raia, V; Maiuri, L; Ilardi, G; Cantone, E; Castaldo, G; Iengo, M

2017-06-01

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) gene. About 2000 mutations have been described so far. We setup an ex vivo model of human nasal epithelial cells (HNECs) to study CF patients testing the effect of novel mutations and molecular therapies. We performed sampling (by brushing), followed by culture and analysis of HNECs using a series of molecular techniques. We performed 50 brushings from CF patients and controls. Using cultured cells, we: i) demonstrated the widely heterogeneous CFTR expression in patients and in controls; ii) defined the splicing effect of a CFTR mutation; iii) assessed the CFTR gating activity in patients bearing different mutations; iv) demonstrated that butyrate significantly enhances CFTR expression. Based on our data, we can conclude: 1) HNEC brushing is performed without anaesthesia and is well tolerated in all CF patients (children and adults); 2) HNECs can be preserved for up to 48 hours before culture allowings multicentre studies; 3) HNECs culture can be considered a suitable model to study the molecular effects of new CFTR gene mutations and/or uncertain meaning specific mutations of carriers; 4) an ex vivo model of HNECs may be used to evaluate, before human use, the effect of new drugs on patients' cells bearing specific CFTR mutations; 5) the methodology is adequate for a quantitative measurement, by fluorescence, of the CFTR gating activity of the HNECs from patients with different genotypes identifying: a) CF patients bearing two severe mutations with an activity < 10% (compared to controls - 100%); b) CF patients bearing at least a mild mutation with an activity of 10-20%; c) CF carriers (heterozygous subjects) with an activity between 40-70%. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

Ethnicity impacts the cystic fibrosis diagnosis: A note of caution.

PubMed

Bosch, Barbara; Bilton, Diana; Sosnay, Patrick; Raraigh, Karen S; Mak, Denise Y F; Ishiguro, Hiroshi; Gulmans, Vincent; Thomas, Muriel; Cuppens, Harry; Amaral, Margarida; De Boeck, Kris

2017-07-01

The diagnosis of Cystic Fibrosis (CF) is by consensus based on the same parameters in all patients, yet the influence of ethnicity has only scarcely been studied. We aimed at elucidating the impact of Asian descent on the diagnosis of CF. We performed a retrospective analysis of the CFTR2 and UK CF databases for clinical phenotype, sweat chloride values and CFTR mutations and compared the diagnostic characteristics of Asian to non-Asian patients with CF. Asian patients with CF do not have a worse clinical phenotype. The repeatedly reported lower FEV 1 of Asian patients with CF is attributable to the influence of ethnicity on lung function in general. However, pancreatic sufficiency is more common in Asian patients with CF. The diagnosis of CF in people with Asian ancestry is heterogeneous as mean sweat chloride values are lower (92±26 versus 99±22mmol/L in controls) and 14% have sweat chloride values below 60mmol/L (versus 6% in non-Asians). Also, CFTR mutations differ from those in Caucasians: 55% of British Asian patients with CF do not have one mutation included in the routine newborn screening panel. Bringing together the largest cohort of patients with CF and Asian ethnicity, we demonstrate that Asian roots impact on all three CF diagnostic pillars. These findings have implications for clinical practice in the increasingly ethnically diverse Western population. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Identification of eight mutations and three sequence variations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghanem, N.; Costes, B.; Girodon, E.

1994-05-15

To determine cystic fibrosis (CF) defects in a sample of 224 non-[Delta]F508 CF chromosomes, the authors used denaturing gradient gel multiplex analysis of CF transmembrane conductance regulator gene segments, a strategy based on blind exhaustive analysis rather than a search for known mutations. This process allowed detection of 11 novel variations comprising two nonsense mutations (Q890X and W1204X), a splice defect (405 + 4 A [yields] G), a frameshift (3293delA), four presumed missense mutations (S912L, H949Y, L1065P, Q1071P), and three sequence polymorphisms (R31C or 223 C/T, 3471 T/C, and T1220I or 3791 C/T). The authors describe these variations, together withmore » the associated phenotype when defects on both CF chromosomes were identified. 8 refs., 1 fig., 1 tab.« less

Genetic analysis of hispanic individuals with cystic fibrosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grebe, T.A.; Doane, W.W.; Norman, R.A.

1994-03-01

The authors have performed molecular genetic analysis of Hispanic individuals with cystic fibrosis (CF) in the southwestern United States. Of 129 CF chromosomes analyzed, oly 46% (59/129) carry [Delta]F508. The G542X mutation was found on 5% (7/129) of CF chromosomes. The 3849+10kbC[yields]T mutation, detected primarily in Ashkenazi Jews, was present on 2% (3/129). R1162X and R334W, mutations identified in Spain and Italy, each occurred on 1.6% (2/129) of CF chromosomes. W1282X and R553X were each detected once. G551D and N1303K were not found. Overall, screening for 22 or more mutations resulted in detection of only 58% of CF transmembrane conductancemore » regulator gene mutations among Hispanic individuals. Analysis of KM19/XV2c haplotypes revealed an unusual distribution. Although the majority of [Delta]508 mutations are on chromosomes of B haplotypes, the other CF mutations are on A and C haplotypes at higher-than-expected frequencies. These genetic analysis demonstrate significant differences between Hispanic individuals with CF and those of the general North American population. Assessment of carrier/affected risk in Hispanic CF individuals cannot, therefore, be based on the mutation frequencies found through studies of the general population but must be adjusted to better reflect the genetic makeup of this ethnic group. Further studies are necessary to identify the causative mutation(s) in this population and to better delineate genotype/phenotype correlations. These will enable counselors to provide more accurate genetic counseling. 22 refs., 2 tabs.« less

Ivacaftor treatment of cystic fibrosis patients with the G551D mutation: a review of the evidence.

PubMed

Kotha, Kavitha; Clancy, John P

2013-10-01

Cystic fibrosis (CF) is a recessive disorder caused by mutations in the gene that encodes the CF transmembrane conductance regulator (CFTR) protein. CFTR protein is a chloride and bicarbonate channel that is critical for normal epithelial ion transport and hydration of epithelial surfaces. Current CF care is supportive, but recent breakthroughs have occurred with the advent of novel therapeutic strategies that assist the function of mutant CFTR proteins. The development and key clinical trial results of ivacaftor, a small molecule that targets gating defects in disease-causing CFTR mutations including G551D CFTR, are summarized in this review. The G551D mutation is reasonably common in the CF patient population and produces a CFTR protein that localizes normally to the plasma membrane, but fails to open in response to cellular cues. Ivacaftor treatment produces dramatic improvements in lung function, weight, lung disease stability, patient-reported outcomes, and CFTR biomarkers in patients with CF harboring the G551D CFTR mutation compared with placebo controls and patients with two copies of the common F508del CFTR mutation. The unprecedented success of ivacaftor treatment for the G551D CF patient population has generated excitement in the CF care community regarding the expansion of its use to other CF patient populations with primary or secondary gating defects.

Impact of the F508del mutation on ovine CFTR, a Cl− channel with enhanced conductance and ATP-dependent gating

PubMed Central

Cai, Zhiwei; Palmai-Pallag, Timea; Khuituan, Pissared; Mutolo, Michael J; Boinot, Clément; Liu, Beihui; Scott-Ward, Toby S; Callebaut, Isabelle; Harris, Ann; Sheppard, David N

2015-01-01

Cross-species comparative studies are a powerful approach to understanding the epithelial Cl− channel cystic fibrosis transmembrane conductance regulator (CFTR), which is defective in the genetic disease cystic fibrosis (CF). Here, we investigate the single-channel behaviour of ovine CFTR and the impact of the most common CF mutation, F508del-CFTR, using excised inside-out membrane patches from transiently transfected CHO cells. Like human CFTR, ovine CFTR formed a weakly inwardly rectifying Cl− channel regulated by PKA-dependent phosphorylation, inhibited by the open-channel blocker glibenclamide. However, for three reasons, ovine CFTR was noticeably more active than human CFTR. First, single-channel conductance was increased. Second, open probability was augmented because the frequency and duration of channel openings were increased. Third, with enhanced affinity and efficacy, ATP more strongly stimulated ovine CFTR channel gating. Consistent with these data, the CFTR modulator phloxine B failed to potentiate ovine CFTR Cl− currents. Similar to its impact on human CFTR, the F508del mutation caused a temperature-sensitive folding defect, which disrupted ovine CFTR protein processing and reduced membrane stability. However, the F508del mutation had reduced impact on ovine CFTR channel gating in contrast to its marked effects on human CFTR. We conclude that ovine CFTR forms a regulated Cl− channel with enhanced conductance and ATP-dependent channel gating. This phylogenetic analysis of CFTR structure and function demonstrates that subtle changes in structure have pronounced effects on channel function and the consequences of the CF mutation F508del. Key points Malfunction of the cystic fibrosis transmembrane conductance regulator (CFTR), a gated pathway for chloride movement, causes the common life-shortening genetic disease cystic fibrosis (CF). Towards the development of a sheep model of CF, we have investigated the function of sheep CFTR. We found that sheep CFTR was noticeably more active than human CFTR, while the most common CF mutation, F508del, had reduced impact on sheep CFTR function. Our results demonstrate that subtle changes in protein structure have marked effects on CFTR function and the consequences of the CF mutation F508del. PMID:25763566

Clinical Sensitivity of Cystic Fibrosis Mutation Panels in a Diverse Population.

PubMed

Hughes, Erin E; Stevens, Colleen F; Saavedra-Matiz, Carlos A; Tavakoli, Norma P; Krein, Lea M; Parker, April; Zhang, Zhen; Maloney, Breanne; Vogel, Beth; DeCelie-Germana, Joan; Kier, Catherine; Anbar, Ran D; Berdella, Maria N; Comber, Paul G; Dozor, Allen J; Goetz, Danielle M; Guida, Louis; Kattan, Meyer; Ting, Andrew; Voter, Karen Z; van Roey, Patrick; Caggana, Michele; Kay, Denise M

2016-02-01

Infants are screened for cystic fibrosis (CF) in New York State (NYS) using an IRT-DNA algorithm. The purpose of this study was to validate and assess clinical validity of the US FDA-cleared Illumina MiSeqDx CF 139-Variant Assay (139-VA) in the diverse NYS CF population. The study included 439 infants with CF identified via newborn screening (NBS) from 2002 to 2012. All had been screened using the Abbott Molecular CF Genotyping Assay or the Hologic InPlex CF Molecular Test. All with CF and zero or one mutation were tested using the 139-VA. DNA extracted from dried blood spots was reliably and accurately genotyped using the 139-VA. Sixty-three additional mutations were identified. Clinical sensitivity of three panels ranged from 76.2% (23 mutations recommended for screening by ACMG/ACOG) to 79.7% (current NYS 39-mutation InPlex panel), up to 86.0% for the 139-VA. For all, sensitivity was highest in Whites and lowest in the Black population. Although the sample size was small, there was a nearly 20% increase in sensitivity for the Black CF population using the 139-VA (68.2%) over the ACMG/ACOG and InPlex panels (both 50.0%). Overall, the 139-VA is more sensitive than other commercially available panels, and could be considered for NBS, clinical, or research laboratories conducting CF screening. © 2015 WILEY PERIODICALS, INC.

Mild CFTR mutations and genetic predisposition to lactase persistence in cystic fibrosis

PubMed Central

Mądry, Edyta; Fidler, Ewa; Sobczyńska-Tomaszewska, Agnieszka; Lisowska, Aleksandra; Krzyżanowska, Patrycja; Pogorzelski, Andrzej; Minarowski, Łukasz; Oralewska, Beata; Mojs, Ewa; Sapiejka, Ewa; Marciniak, Ryszard; Sands, Dorota; Korzon-Burakowska, Anna; Kwiecień, Jarosław; Walkowiak, Jarosław

2011-01-01

Taking into account the reported incidence of hypolactasia in cystic fibrosis (CF) and the possible impact of milk products on nutritional status we aimed to assess the genetic predisposition to adult-type hypolactasia (ATH) and its incidence in CF. Single nucleotide polymorphism upstream of the lactase gene (LCT) was assessed in 289 CF patients. In subject with −13910C/C genotype (C/C) predisposing to ATH, hydrogen-methane breath test (BT) with lactose loading was conducted and clinical symptoms typical for lactose malabsorption were assessed. The percentage of CF patients with C/C was similar to that observed in healthy subjects (HS) (31.5 vs 32.5% ). Eleven out of 52 (24.5%) CF C/C patients had abnormal BT results. The recalculated frequency of lactose malabsorption was similar for the entire CF and HS populations (6.9 vs 7.2%). Similarly as in the control group, few CF patients have identified and linked to lactose consumption clinical symptoms. The frequency of LCT polymorphic variants in CF patients having and not having severe mutations of CFTR gene showed significant differences. The C allele was more frequent in homozygotes of the severe mutations than in patients carrying at least one mild/unknown mutation (P<0.0028) and in patients with at least one mild mutation (P<0.0377). In conclusion, CF patients carrying mild CFTR mutations seem to have lower genetic predisposition to ATH. Lactose malabsorption due to ATH in CF is not more frequent than in the general population. Symptomatic assessment of lactose malabsorption in CF is not reliable. PMID:21407263

Non-invasive prenatal diagnosis for cystic fibrosis: detection of paternal mutations, exploration of patient preferences and cost analysis.

PubMed

Hill, Melissa; Twiss, Philip; Verhoef, Talitha I; Drury, Suzanne; McKay, Fiona; Mason, Sarah; Jenkins, Lucy; Morris, Stephen; Chitty, Lyn S

2015-10-01

We aim to develop non-invasive prenatal diagnosis (NIPD) for cystic fibrosis (CF) and determine costs and implications for implementation. A next-generation sequencing assay was developed to detect ten common CF mutations for exclusion of the paternal mutation in maternal plasma. Using uptake data from a study exploring views on NIPD for CF, total test-related costs were estimated for the current care pathway and compared with those incorporating NIPD. The assay reliably predicted mutation status in all control and maternal plasma samples. Of carrier or affected adults with CF (n = 142) surveyed, only 43.5% reported willingness to have invasive testing for CF with 94.4% saying they would have NIPD. Using these potential uptake data, the incremental costs of NIPD over invasive testing per 100 pregnancies at risk of CF are £9025 for paternal mutation exclusion, and £26,510 for direct diagnosis. We have developed NIPD for risk stratification in around a third of CF families. There are economic implications due to potential increased test demand to inform postnatal management rather than to inform decisions around termination of an affected pregnancy. © 2015 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

Nasal potential difference in cystic fibrosis considering severe CFTR mutations.

PubMed

Ng, Ronny Tah Yen; Marson, Fernando Augusto de Lima; Ribeiro, Jose Dirceu; Ribeiro, Antonio Fernando; Bertuzzo, Carmen Silvia; Ribeiro, Maria Angela Gonçalves de Oliveira; Severino, Silvana Dalge; Sakano, Eulalia

2015-01-01

The gold standard for diagnosing cystic fibrosis (CF) is a sweat chloride value above 60 mEq/L. However, this historical and important tool has limitations; other techniques should be studied, including the nasal potential difference (NPD) test. CFTR gene sequencing can identify CFTR mutations, but this method is time-consuming and too expensive to be used in all CF centers. The present study compared CF patients with two classes I-III CFTR mutations (10 patients) (G1), CF patients with classes IV-VI CFTR mutations (five patients) (G2), and 21 healthy subjects (G3). The CF patients and healthy subjects also underwent the NPD test. A statistical analysis was performed using the Mann-Whitney, Kruskal-Wallis, χ(2), and Fisher's exact tests, α = 0.05. No differences were observed between the CF patients and healthy controls for the PDMax, Δamiloride, and Δchloride + free + amiloride markers from the NPD test. For the finger value, a difference between G2 and G3 was described. The Wilschanski index values were different between G1 and G3. In conclusion, our data showed that NPD is useful for CF diagnosis when classes I-III CFTR mutations are screened. However, if classes IV-VI are considered, the NPD test showed an overlap in values with healthy subjects.

Nasal Potential Difference in Cystic Fibrosis considering Severe CFTR Mutations

PubMed Central

Ng, Ronny Tah Yen; Marson, Fernando Augusto de Lima; Ribeiro, Jose Dirceu; Ribeiro, Antonio Fernando; Bertuzzo, Carmen Silvia; Ribeiro, Maria Angela Gonçalves de Oliveira; Severino, Silvana Dalge; Sakano, Eulalia

2015-01-01

The gold standard for diagnosing cystic fibrosis (CF) is a sweat chloride value above 60 mEq/L. However, this historical and important tool has limitations; other techniques should be studied, including the nasal potential difference (NPD) test. CFTR gene sequencing can identify CFTR mutations, but this method is time-consuming and too expensive to be used in all CF centers. The present study compared CF patients with two classes I-III CFTR mutations (10 patients) (G1), CF patients with classes IV-VI CFTR mutations (five patients) (G2), and 21 healthy subjects (G3). The CF patients and healthy subjects also underwent the NPD test. A statistical analysis was performed using the Mann-Whitney, Kruskal-Wallis, χ 2, and Fisher's exact tests, α = 0.05. No differences were observed between the CF patients and healthy controls for the PDMax, Δamiloride, and Δchloride + free + amiloride markers from the NPD test. For the finger value, a difference between G2 and G3 was described. The Wilschanski index values were different between G1 and G3. In conclusion, our data showed that NPD is useful for CF diagnosis when classes I-III CFTR mutations are screened. However, if classes IV-VI are considered, the NPD test showed an overlap in values with healthy subjects. PMID:25667564

Non-invasive prenatal diagnosis for cystic fibrosis: detection of paternal mutations, exploration of patient preferences and cost analysis

PubMed Central

Hill, Melissa; Twiss, Philip; Verhoef, Talitha I; Drury, Suzanne; McKay, Fiona; Mason, Sarah; Jenkins, Lucy; Morris, Stephen; Chitty, Lyn S

2015-01-01

Abstract Objectives We aim to develop non-invasive prenatal diagnosis (NIPD) for cystic fibrosis (CF) and determine costs and implications for implementation. Methods A next-generation sequencing assay was developed to detect ten common CF mutations for exclusion of the paternal mutation in maternal plasma. Using uptake data from a study exploring views on NIPD for CF, total test-related costs were estimated for the current care pathway and compared with those incorporating NIPD. Results The assay reliably predicted mutation status in all control and maternal plasma samples. Of carrier or affected adults with CF (n = 142) surveyed, only 43.5% reported willingness to have invasive testing for CF with 94.4% saying they would have NIPD. Using these potential uptake data, the incremental costs of NIPD over invasive testing per 100 pregnancies at risk of CF are £9025 for paternal mutation exclusion, and £26 510 for direct diagnosis. Conclusions We have developed NIPD for risk stratification in around a third of CF families. There are economic implications due to potential increased test demand to inform postnatal management rather than to inform decisions around termination of an affected pregnancy. © 2015 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd. PMID:25708280

Ethnic heterogeneity and cystic fibrosis transmembrane regulator (CFTR) mutation frequencies in Chicago-area CF families

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ober, C.; Lester, L.A.; Mott, C.

1992-12-01

The identification of a common mutation, [Delta]F508, in the CFTR gene allowed, for the first time, the detection of cystic fibrosis (CF) carriers in the general population. Further genetic studies revealed >100 additional disease-causing mutations in this gene, few of which occur on >1% of CF chromosomes in any ethnic group. Prior to establishing counseling guidelines and carrier risk assessments, the authors sought to establish the frequencies of the CFTR mutations that are present in CF families living in the Chicago are, a region notable for its ethnic heterogeneity. Their sample included 283 unrelated CF carriers, with the following ethnicmore » composition: 78% non-Ashkenazi Caucasians, 5% Ashkenazi, 9% African-American, 3% Mexican, 0.3% Native American, and 5% mixed ancestry. When a panel of 10 mutations ([Delta]F508, [Delta]I507, G542X, G551D, R553X, S549N, R1162X, W1282X, N1303K, and 1717-1G[r arrow]A) was used, detection rates ranged from 75% in non-Ashkenazi Caucasians to 40% in African-Americans. These data suggest that the goal of screening for 90%-95% of CF mutations may be unrealistic in this and other, similar US populations. 22 refs., 1 tab.« less

Clinical characterization and diagnosis of cystic fibrosis through exome sequencing in Chinese infants with Bartter-syndrome-like hypokalemia alkalosis.

PubMed

Qiu, Liru; Yang, Fengjie; He, Yonghua; Yuan, Huiqing; Zhou, Jianhua

2018-03-09

Cystic fibrosis (CF) is a fatal autosomal-recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. CF is characterized by recurrent pulmonary infection with obstructive pulmonary disease. CF is common in the Caucasian population but is rare in the Chinese population. The symptoms of early-stage CF are often untypical and may sometimes manifest as Bartter syndrome (BS)-like hypokalemic alkalosis. Therefore, the ability of doctors to differentiate CF from BS-like hypokalemic alkalosis in Chinese infants is a great challenge in the timely and accurate diagnosis of CF. In China, sporadic CF has not been diagnosed in children younger than three years of age to date. Three infants, who were initially admitted to our hospital over the period of June 2013 to September 2014 with BS-like hypokalemic alkalosis, were diagnosed with CF through exome sequencing and sweat chloride measurement. The compound heterozygous mutations of the CFTR gene were detected in two infants, and a homozygous missense mutation was found in one infant. Among the six identified mutations, two are novel point mutations (c.1526G > C and c.3062C > T) that are possibly pathogenic. The three infants are the youngest Chinese patients to have been diagnosed with sporadic CF at a very early stage. Follow-up examination showed that all of the cases remained symptom-free after early intervention, indicating the potential benefit of very early diagnosis and timely intervention in children with CF. Our results demonstrate the necessity of distinguishing CF from BS in Chinese infants with hypokalemic alkalosis and the significant diagnostic value of powerful exome sequencing for rare genetic diseases. Furthermore, our findings expand the CFTR mutation spectrum associated with CF.

CFTR Mutations Spectrum and the Efficiency of Molecular Diagnostics in Polish Cystic Fibrosis Patients

PubMed Central

Ziętkiewicz, Ewa; Rutkiewicz, Ewa; Pogorzelski, Andrzej; Klimek, Barbara; Voelkel, Katarzyna; Witt, Michał

2014-01-01

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane regulator gene (CFTR). In light of the strong allelic heterogeneity and regional specificity of the mutation spectrum, the strategy of molecular diagnostics and counseling in CF requires genetic tests to reflect the frequency profile characteristic for a given population. The goal of the study was to provide an updated comprehensive estimation of the distribution of CFTR mutations in Polish CF patients and to assess the effectiveness of INNOLiPA_CFTR tests in Polish population. The analyzed cohort consisted of 738 patients with the clinically confirmed CF diagnosis, prescreened for molecular defects using INNOLiPA_CFTR panels from Innogenetics. A combined efficiency of INNOLiPA CFTR_19 and CFTR_17_TnUpdate tests was 75.5%; both mutations were detected in 68.2%, and one mutation in 14.8% of the affected individuals. The group composed of all the patients with only one or with no mutation detected (109 and 126 individuals, respectively) was analyzed further using a mutation screening approach, i.e. SSCP/HD (single strand conformational polymorphism/heteroduplex) analysis of PCR products followed by sequencing of the coding sequence. As a result, 53 more mutations were found in 97 patients. The overall efficiency of the CF allele detection was 82.5% (7.0% increase compared to INNOLiPA tests alone). The distribution of the most frequent mutations in Poland was assessed. Most of the mutations repetitively found in Polish patients had been previously described in other European populations. The most frequent mutated allele, F508del, represented 54.5% of Polish CF chromosomes. Another eight mutations had frequencies over 1%, 24 had frequencies between 1 and 0.1%; c.2052-2053insA and c.3468+2_3468+3insT were the most frequent non-INNOLiPA mutations. Mutation distribution described herein is also relevant to the Polish diaspora. Our study also demonstrates that the reported efficiency of mutation detection strongly depends on the diagnostic experience of referring health centers. PMID:24586523

CFTR mutations spectrum and the efficiency of molecular diagnostics in Polish cystic fibrosis patients.

PubMed

Ziętkiewicz, Ewa; Rutkiewicz, Ewa; Pogorzelski, Andrzej; Klimek, Barbara; Voelkel, Katarzyna; Witt, Michał

2014-01-01

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane regulator gene (CFTR). In light of the strong allelic heterogeneity and regional specificity of the mutation spectrum, the strategy of molecular diagnostics and counseling in CF requires genetic tests to reflect the frequency profile characteristic for a given population. The goal of the study was to provide an updated comprehensive estimation of the distribution of CFTR mutations in Polish CF patients and to assess the effectiveness of INNOLiPA_CFTR tests in Polish population. The analyzed cohort consisted of 738 patients with the clinically confirmed CF diagnosis, prescreened for molecular defects using INNOLiPA_CFTR panels from Innogenetics. A combined efficiency of INNOLiPA CFTR_19 and CFTR_17_TnUpdate tests was 75.5%; both mutations were detected in 68.2%, and one mutation in 14.8% of the affected individuals. The group composed of all the patients with only one or with no mutation detected (109 and 126 individuals, respectively) was analyzed further using a mutation screening approach, i.e. SSCP/HD (single strand conformational polymorphism/heteroduplex) analysis of PCR products followed by sequencing of the coding sequence. As a result, 53 more mutations were found in 97 patients. The overall efficiency of the CF allele detection was 82.5% (7.0% increase compared to INNOLiPA tests alone). The distribution of the most frequent mutations in Poland was assessed. Most of the mutations repetitively found in Polish patients had been previously described in other European populations. The most frequent mutated allele, F508del, represented 54.5% of Polish CF chromosomes. Another eight mutations had frequencies over 1%, 24 had frequencies between 1 and 0.1%; c.2052-2053insA and c.3468+2_3468+3insT were the most frequent non-INNOLiPA mutations. Mutation distribution described herein is also relevant to the Polish diaspora. Our study also demonstrates that the reported efficiency of mutation detection strongly depends on the diagnostic experience of referring health centers.

The 3849 + 10 kB C-->T mutation in a 21-year-old patient with cystic fibrosis.

PubMed

Kaplan, D M; Niv, A; Aviram, M; Parvari, R; Leiberman, A; Fliss, D M

1996-12-01

Cystic fibrosis (CF) is the most common lethal inherited disease in the white population. It is characterized by exocrine gland epithelia dysfunction, which leads to pulmonary and pancreatic insufficiency. Since the cloning of the CF gene in 1989 and the identification of the most common CF mutation (delta F508), more than 400 different mutations have been described. These mutations appear to contribute to the heterogeneity of the CF phenotype and several reports have speculated on the relationship between the most common CF mutations and the patient's clinical status. We report the case of a 21-year-old woman with longstanding chronic pansinusitis, nasal polyposis, chronic cough and severe nasal crusting. During a period of five years she had been followed by her otolaryngologist and pediatric pulmonologist. Sweat tests performed at the age of 17 and 18 were within normal limits and she underwent repeated conventional sinonasal procedures, with no improvement in her clinical status. On her present admission, sweat tests showed a 70 meq/l chloride concentration. The diagnosis of CF was then confirmed by DNA analysis and the patient was found to carry the 3849 + 10 kB C-->T mutation. The early detection of this newly recognized form of CF in adults as well as in children presenting with sinonasal symptoms is critical for life expectancy and quality.

Distribution of CFTR mutations in Eastern Hungarians: relevance to genetic testing and to the introduction of newborn screening for cystic fibrosis.

PubMed

Ivady, Gergely; Madar, Laszlo; Nagy, Bela; Gonczi, Ferenc; Ajzner, Eva; Dzsudzsak, Erika; Dvořáková, Lenka; Gombos, Eva; Kappelmayer, Janos; Macek, Milan; Balogh, Istvan

2011-05-01

The aim of this study was characterization of an updated distribution of CFTR mutations in a representative cohort of 40 CF patients with the classical form of the disease drawn from Eastern Hungary. Due to the homogeneity of the Hungarian population our data are generally applicable to other regions of the country, including the sizeable diaspora. We utilized the recommended "cascade" CFTR mutation screening approach, initially using a commercial assay, followed by examination of the common "Slavic" deletion CFTRdele2,3(21kb). Subsequently, the entire CFTR coding region of the CFTR gene was sequenced in patients with yet unidentified mutations. The Elucigene CF29(Tm) v2 assay detected 81.25% of all CF causing mutations. An addition of the CFTRdele2,3(21kb) increased the mutation detection rate to 86.25%. DNA sequencing enabled us to identify mutations on 79/80 CF alleles. Mutations [CFTRdele2,3(21kb), p.Gln685ThrfsX4 (2184insA) were found at an unusually high frequency, each comprising 5.00% of all CF alleles. We have identified common CF causing mutations in the Hungarian population with the most common mutations (p.Phe508del, p.Asn1303Lys, CFTRdele2,3(21kb), 2184insA, p.Gly542X, and p.Leu101X), comprising over 93.75% of all CF alleles. Obtained data are applicable to the improvement of DNA diagnostics in Hungary and beyond, and are the necessary prerequisite for the introduction of a nationwide "two tier" CF newborn screening program. Copyright © 2011 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Screening for five mutations detects 97% of cystic fibrosis (CF) chromosomes and predicts a carrier frequency of 1:29 in the Jewish Ashkenazi population

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abeliovich, D.; Lavon, I.P.; Lerer, I.

1992-11-01

To determine the distribution and frequency of cystic fibrosis (CF) mutations in the Israeli population, the authors have screened 96 patients for 11 relatively common mutations. Five mutations - [Delta]F508, G542X, W1282X, N1303K, and 3849 + 10kb C[yields]T-were found to account for 97% of the CF alleles in the Ashkenazi Jews. In contrast, of the 11 mutations tested, only [Delta]F508 was detected in Jewish patients of Sephardic or Oriental origin, accounting for 43% of the CF alleles. Four mutations - [Delta]F508, G542X, W1282X, and N1303K- accounted for 55% of the CF alleles in Arab patients. In a pilot screening study,more » a random sample of 424 Ashkenazi individuals was analyzed for three mutations - [Delta]F508, W128X, and G542X. Thirteen individuals were detected as heterozygotes (six for [Delta]F508 and seven for W1282X), predicting a heterozygote frequency of 1:29. This is similar to the frequency of carriers in the Caucasian population of northern European ancestry. On the basis of these data, the Ashkenazi populations is considered to be a candidate for CF heterozygote screening. 32 refs., 2 tabs.« less

Mutation analysis of the cystic fibrosis transmembrane regulator gene in native American populations of the southwest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grebe, T.A.; Doane, W.W.; Norman, R.A.

1992-10-01

The authors report DNA and clinical analysis of cystic fibrosis (CF) in two previously unstudied, genetically isolated populations: Pueblo and Navajo Native Americans. Direct mutation analysis of six mutations of the CFTR gene - namely, [Delta]F508, G542X, G551D, R553X, N1303K, and W1282X - was performed on PCR-amplified genomic DNA extracted from blood samples. Haplotype analyses with marker/enzyme pairs XV2c/TaqI and KM29/PstI were performed as well. Of the 12 affected individuals studied, no [Delta]F508 mutation was detected; only one G542X mutation was found. None of the other mutations was detected. All affected individuals have either an AA, AC, or CC haplotype,more » except for the one carrying the G542X mutation, who has the haplotye AB. Clinically, six of the affected individuals examined exhibit growth deficiency, and five (all from the Zuni Pueblo) have a severe CF phenotype. Four of the six Zunis with CF are also microcephalic, a finding not previously noted in CF patients. The DNA data have serious implications for risk assessment of CF carrier status for these people. 14 refs., 3 tabs.« less

Early severe anemia as the first sign of cystic fibrosis.

PubMed

Sismanlar, Tugba; Aslan, Ayşe Tana; Köse, Mehmet; Pekcan, Sevgi; Ezgü, Fatih Süheyl; Budakoğlu, Işıl İrem; Yenicesu, İdil

2016-09-01

Severe anemia is reported to occur rarely in patients with cystic fibrosis (CF). This study aimed to determine the factors associated with early severe anemia in infants with CF. This study included 231 infants with CF from 3 pediatric CF centers ten year period that were retrospectively reviewed in terms of severe anemia as the first sign of CF. Factors that could affect anemia, such as age, pancreatic insufficiency, mutations, vitamin A and E, and albumin level were evaluated. Clinical and laboratory findings in CF patients that presented with severe anemia and no respiratory symptoms were compared to those in CF patients that did not present with severe anemia. Severe anemia as the first sign of CF was noted in 17 of 231 patients. Patient age, prolonged PT/INR and the albumin level differed significantly between the 2 groups of patients (P < 0.001). Feeding pattern, pancreatic insufficiency, vitamin E and A levels, and the types of genetic mutations did not differ between the 2 groups. The mean hemoglobin level was 5.59 ± 0.21 g/dL and respiratory symptoms began a mean 6.3 months after diagnosis of CF in the anemia group. In early infancy severe anemia in the absence of respiratory symptoms can be the first sign of CF. CF should be considered in the differential diagnosis of severe anemia in infants. Anemia can occur several months before respiratory symptoms in patients with CF and may be caused due to several reasons. • Severe anemia as a first sign is reported to occur rarely in patients with cystic fibrosis. • Although anemia is well known in cystic fibrosis, factors that cause severe anemia are not known clearly. What is New: • This study shows the importance of severe anemia as the first sign of cystic fibrosis. • Anemia can occur several months before respiratory symptoms in patients with CF.

Comprehensive CFTR gene analysis of the French cystic fibrosis screened newborn cohort: implications for diagnosis, genetic counseling, and mutation-specific therapy.

PubMed

Audrézet, Marie Pierre; Munck, Anne; Scotet, Virginie; Claustres, Mireille; Roussey, Michel; Delmas, Dominique; Férec, Claude; Desgeorges, Marie

2015-02-01

Newborn screening (NBS) for cystic fibrosis (CF) was implemented throughout France in 2002. It involves a four-tiered procedure: immunoreactive trypsin (IRT)/DNA/IRT/sweat test [corrected] was implemented throughout France in 2002. The aim of this study was to assess the performance of molecular CFTR gene analysis from the French NBS cohort, to evaluate CF incidence, mutation detection rate, and allelic heterogeneity. During the 8-year period, 5,947,148 newborns were screened for cystic fibrosis. The data were collected by the Association Française pour le Dépistage et la Prévention des Handicaps de l'Enfant. The mutations identified were classified into four groups based on their potential for causing disease, and a diagnostic algorithm was proposed. Combining the genetic and sweat test results, 1,160 neonates were diagnosed as having cystic fibrosis. The corresponding incidence, including both the meconium ileus (MI) and false-negative cases, was calculated at 1 in 4,726 live births. The CF30 kit, completed with a comprehensive CFTR gene analysis, provides an excellent detection rate of 99.77% for the mutated alleles, enabling the identification of a complete genotype in 99.55% of affected neonates. With more than 200 different mutations characterized, we confirmed the French allelic heterogeneity. The very good sensitivity, specificity, and positive predictive value obtained suggest that the four-tiered IRT/DNA/IRT/sweat test procedure may provide an effective strategy for newborn screening for cystic fibrosis.

Amniotic fluid digestive enzyme analysis is useful for identifying CFTR gene mutations of unclear significance.

PubMed

Oca, Florine; Dreux, Sophie; Gérard, Bénédicte; Simon-Bouy, Brigitte; de Becdelièvre, Alix; Ferec, Claude; Girodon, Emmanuelle; Muller, Françoise

2009-12-01

The large number of CFTR [cystic fibrosis transmembrane conductance regulator (ATP-binding cassette sub-family C, member 7)] mutations and the existence of variants of unclear significance complicate the prenatal diagnosis of cystic fibrosis (CF). The aim of this study was to determine whether the pattern of amniotic fluid digestive enzymes (AF-DEs) could be correlated with the severity of CFTR mutations. The AF-DE pattern (gamma-glutamyltranspeptidase, aminopeptidase M, and the intestinal isoform of alkaline phosphatase) was retrospectively analyzed in 43 AF samples. All fetuses presented 2 CFTR mutations, which were classified according to the severity of the disease: CF/CF (n = 38); CF/CFTR-related disorders (n = 1); and CF/unknown variant (n = 4). The relationships between clinical CF status, CFTR mutations, and AF-DE pattern were studied. Of 38 severely affected CF fetuses, an "obstructive" AF-DE pattern was observed in 15 of 15 samples collected before 22 weeks, irrespective of the CFTR mutation (diagnostic sensitivity, 100%; diagnostic specificity, 99.8%). In the 23 fetuses evaluated after 22 weeks, the AF-DE pattern was abnormal in 7 cases and noncontributive in 16 (diagnostic sensitivity, 30.4%; diagnostic specificity, 99.8%). Of the 5 questionable cases (F508del/N1224K, F508del/L73F, 3849+10kbC>T/G1127E, F508del/S1235R, F508del/G622D), all were CF symptom free at 2-4 years of follow-up. The AF-DE pattern (<22 weeks) was typical in 3 cases but abnormal in the last 2 cases. AF-DE analysis is of value for prenatal CF diagnosis in classic forms of CF and could be helpful in nonclassic CF.

Cystic fibrosis (CF) mutation detection and frequencies in central New York state using single strand conformation (SSC) and heteroduplex analysis (HA) gel analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shrimpton, A.E.; Lamberson, C.M.; Hicks, K.E.

1994-09-01

Over 100 cystic fibrosis (CF) bearing chromosomes from patients living in central New York state have been screened in order to identify their CF mutations. Ethnic background information and parental samples were also collected when available. Polymerase chain reaction (PCR) amplified products from exons 3, 4, 5, 7, 9, 10, 11, 12, 13, 14B, 15, 17B, 19, 20, 21 and intro 19 have been screened for over 50 known CF mutations by restriction enzyme digest, heteroduplex analysis (HA) and/or single stand conformation (SSC) gel analysis. The exon 9 PCR product was difficult to analyze by HA or SSC gel analysis.more » Restriction enzyme site generating PCR primers were used to identify the R117H, 711+1,G>T, G542X, 1717-1,G>A, 1898-1,G>A and N1303K CF mutations. Haplotyping at CFTR-linked (xv-2c/Taq I, km19/Pst, I, MP6d.9/Msp I and J3.11/Pst I) and CFTR intragenic markers (intron 6 GATT{sub n}, 1540 A/G, 1898+152,T/A) was performed to aid in CF mutation identification.« less

Assessment of Correlation between Sweat Chloride Levels and Clinical Features of Cystic Fibrosis Patients.

PubMed

Raina, Manzoor A; Khan, Mosin S; Malik, Showkat A; Raina, Ab Hameed; Makhdoomi, Mudassir J; Bhat, Javed I; Mudassar, Syed

2016-12-01

Cystic Fibrosis (CF) is an autosomal recessive disorder and the incidence of this disease is undermined in Northern India. The distinguishable salty character of the sweat belonging to individuals suffering from CF makes sweat chloride estimation essential for diagnosis of CF disease. The aim of this prospective study was to elucidate the relationship of sweat chloride levels with clinical features and pattern of CF. A total of 182 patients, with clinical features of CF were included in this study for quantitative measurement of sweat chloride. Sweat stimulation and collection involved pilocarpine iontophoresis based on the Gibson and Cooks methodology. The quantitative estimation of chloride was done by Schales and Schales method with some modifications. Cystic Fibrosis Trans Membrane Conductance Regulator (CFTR) mutation status was recorded in case of patients with borderline sweat chloride levels to correlate the results and for follow-up. Out of 182 patients having clinical features consistent with CF, borderline and elevated sweat chloride levels were present in 9 (5%) and 41 (22.5%) subjects respectively. Elevated sweat chloride levels were significantly associated with wheeze, Failure To Thrive (FTT), history of CF in Siblings, product of Consanguineous Marriage (CM), digital clubbing and steatorrhoea on univariate analysis. On multivariate analysis only wheeze, FTT and steatorrhoea were found to be significantly associated with elevated sweat chloride levels (p<0.05). Among the nine borderline cases six cases were positive for at least two CFTR mutations and rest of the three cases were not having any mutation in CFTR gene. The diagnosis is often delayed and the disease is advanced in most patients at the time of diagnosis. Sweat testing is a gold standard for diagnosis of CF patients as genetic mutation profile being heterozygous and unlikely to become diagnostic test.

Mutation and new polymorphisms insight in introns 11 to 14a of CFTR gene of northern Iranian cystic fibrosis patients.

PubMed

Esmaeili Dooki, Mohammad Reza; Tabaripour, Reza; Rahimi, Razieh; Akhavan-Niaki, Haleh

2015-06-15

Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians, caused by mutation in cystic fibrosis transmembrane conductance regulator (CFTR). The type and distribution of mutations vary widely between different countries and ethnic groups. We therefore aimed to perform a comprehensive analysis of the CFTR gene in northern Iranian CF patients. Forty northern Iranian CF patients were analyzed for mutations in introns 11 to 14a of their CFTR genes, using sequencing and reverse dot blot methods. Five normal subjects were also analyzed as normal control. One mutation and seven polymorphisms were identified. Of the eighty alleles studied, c.2043delG in exon 13 represented 12.5% of mutant alleles and was associated with two distinct haplotypes. rs1042077T>G, rs4148712delAT, rs4148711T>A and rs3808183 T>C with frequencies varying between 29.2% and 6.9% for the least common allele, as well as three new polymorphisms c.1680-224C>A (11.1%), c.2491-275T>G (14.1%) and c.2491-274C>G (35.9%) were detected. These findings suggest a founder effect for c.2043delG in the Middle East and will assist in genetic counseling, prenatal diagnosis and future screening of CF in Iran. Copyright © 2015 Elsevier B.V. All rights reserved.

Evolution of the Pseudomonas aeruginosa Aminoglycoside Mutational Resistome In Vitro and in the Cystic Fibrosis Setting.

PubMed

López-Causapé, Carla; Rubio, Rosa; Cabot, Gabriel; Oliver, Antonio

2018-04-01

Inhaled administration of high doses of aminoglycosides is a key maintenance treatment of Pseudomonas aeruginosa chronic respiratory infections in cystic fibrosis (CF). We analyzed the dynamics and mechanisms of stepwise high-level tobramycin resistance development in vitro and compared the results with those of isogenic pairs of susceptible and resistant clinical isolates. Resistance development correlated with fusA1 mutations in vitro and in vivo. pmrB mutations, conferring polymyxin resistance, were also frequently selected in vitro In contrast, mutational overexpression of MexXY, a hallmark of aminoglycoside resistance in CF, was not observed in in vitro evolution experiments. Copyright © 2018 American Society for Microbiology.

Extensive sequence analysis of CFTR, SCNN1A, SCNN1B, SCNN1G and SERPINA1 suggests an oligogenic basis for cystic fibrosis-like phenotypes.

PubMed

Ramos, M D; Trujillano, D; Olivar, R; Sotillo, F; Ossowski, S; Manzanares, J; Costa, J; Gartner, S; Oliva, C; Quintana, E; Gonzalez, M I; Vazquez, C; Estivill, X; Casals, T

2014-07-01

The term cystic fibrosis (CF)-like disease is used to describe patients with a borderline sweat test and suggestive CF clinical features but without two CFTR(cystic fibrosis transmembrane conductance regulator) mutations. We have performed the extensive molecular analysis of four candidate genes (SCNN1A, SCNN1B, SCNN1G and SERPINA1) in a cohort of 10 uncharacterized patients with CF and CF-like disease. We have used whole-exome sequencing to characterize mutations in the CFTR gene and these four candidate genes. CFTR molecular analysis allowed a complete characterization of three of four CF patients. Candidate variants in SCNN1A, SCNN1B, SCNN1G and SERPINA1 in six patients with CF-like phenotypes were confirmed by Sanger sequencing and were further supported by in silico predictive analysis, pedigree studies, sweat test in other family members, and analysis in CF patients and healthy subjects. Our results suggest that CF-like disease probably results from complex genotypes in several genes in an oligogenic form, with rare variants interacting with environmental factors. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

CFTR gene mutations in isolated chronic obstructive pulmonary disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pignatti, P.F.; Bombien, C.; Marigo, C.

1994-09-01

In order to identify a possible hereditary predisposition to the development of chronic obstructive pulmonary disease (COPD), we have looked for the presence of cystic fibrosis transmembrane regulator (CFTR) gene DNA sequence modifications in 28 unrelated patients with no signs of cystic fibrosis. The known mutations in Italian CF patients, as well as the most frequent worldwide CF mutations, were investigated. In addition, a denaturing gradient gel electrophoresis analysis of about half of the coding sequence of the gene in 56 chromosomes from the patients and in 102 chromosomes from control individuals affected by other pulmonary diseases and from normalmore » controls was performed. Nine different CFTR gene mutations and polymorphisms were found in seven patients, a highly significant increase over controls. Two of the patients were compound heterozygotes. Two frequent CF mutations were detected: deletion F508 and R117H; two rare CF mutations: R1066C and 3667ins4; and five CF sequence variants: R75Q (which was also described as a disease-causing mutation in male sterility cases due to the absence of the vasa deferentia), G576A, 2736 A{r_arrow}G, L997F, and 3271+18C{r_arrow}T. Seven (78%) of the mutations are localized in transmembrane domains. Six (86%) of the patients with defined mutations and polymorphisms had bronchiectasis. These results indicate that CFTR gene mutations and sequence alterations may be involved in the etiopathogenesis of some cases of COPD.« less

Nationwide genetic analysis for molecularly unresolved cystic fibrosis patients in a multiethnic society: implications for preconception carrier screening.

PubMed

Behar, Doron M; Inbar, Ori; Shteinberg, Michal; Gur, Michal; Mussaffi, Huda; Shoseyov, David; Ashkenazi, Moshe; Alkrinawi, Soliman; Bormans, Concetta; Hakim, Fahed; Mei-Zahav, Meir; Cohen-Cymberknoh, Malena; Dagan, Adi; Prais, Dario; Sarouk, Ifat; Stafler, Patrick; Bar Aluma, Bat El; Akler, Gidon; Picard, Elie; Aviram, Micha; Efrati, Ori; Livnat, Galit; Rivlin, Joseph; Bentur, Lea; Blau, Hannah; Kerem, Eitan; Singer, Amihood

2017-05-01

Preconception carrier screening for cystic fibrosis (CF) is usually performed using ethnically targeted panels of selected mutations. This has been recently challenged by the use of expanded, ethnically indifferent, pan-population panels. Israel is characterized by genetically heterogeneous populations carrying a wide range of CFTR mutations. To assess the potential of expanding the current Israeli preconception screening program, we sought the subset of molecularly unresolved CF patients listed in the Israeli CF data registry comprising ~650 patients. An Israeli nationwide genotyping of 152 CF cases, representing 176 patients lacking molecular diagnosis, was conducted. Molecular analysis included Sanger sequencing for all exons and splice sites, multiplex ligation probe amplification (MLPA), and next-generation sequencing of the poly-T/TG tracts. We identified 54 different mutations, of which only 16 overlapped the 22 mutations included in the Israeli preconception screening program. A total of 29/54 (53.7%) mutations were already listed as CF causing by the CFTR2 database, and only 4/54 (7.4%) were novel. Molecular diagnosis was reached in 78/152 (51.3%) cases. Prenatal diagnosis of 24/78 (30.8%) cases could have been achieved by including all CFTR2-causing mutations in the Israeli panel. Our data reveal an overwhelming hidden abundance of CFTR gene mutations suggesting that expanded preconception carrier screening might achieve higher preconception detection rates.

A New Targeted CFTR Mutation Panel Based on Next-Generation Sequencing Technology.

PubMed

Lucarelli, Marco; Porcaro, Luigi; Biffignandi, Alice; Costantino, Lucy; Giannone, Valentina; Alberti, Luisella; Bruno, Sabina Maria; Corbetta, Carlo; Torresani, Erminio; Colombo, Carla; Seia, Manuela

2017-09-01

Searching for mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR) is a key step in the diagnosis of and neonatal and carrier screening for cystic fibrosis (CF), and it has implications for prognosis and personalized therapy. The large number of mutations and genetic and phenotypic variability make this search a complex task. Herein, we developed, validated, and tested a laboratory assay for an extended search for mutations in CFTR using a next-generation sequencing-based method, with a panel of 188 CFTR mutations customized for the Italian population. Overall, 1426 dried blood spots from neonatal screening, 402 genomic DNA samples from various origins, and 1138 genomic DNA samples from patients with CF were analyzed. The assay showed excellent analytical and diagnostic operative characteristics. We identified and experimentally validated 159 (of 188) CFTR mutations. The assay achieved detection rates of 95.0% and 95.6% in two large-scale case series of CF patients from central and northern Italy, respectively. These detection rates are among the highest reported so far with a genetic test for CF based on a mutation panel. This assay appears to be well suited for diagnostics, neonatal and carrier screening, and assisted reproduction, and it represents a considerable advantage in CF genetic counseling. Copyright © 2017 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Manipulating proteostasis to repair the F508del-CFTR defect in cystic fibrosis.

PubMed

Esposito, Speranza; Tosco, Antonella; Villella, Valeria R; Raia, Valeria; Kroemer, Guido; Maiuri, Luigi

2016-12-01

Cystic fibrosis (CF) is a lethal monogenic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that entails the (diagnostic) increase in sweat electrolyte concentrations, progressive lung disease with chronic inflammation and recurrent bacterial infections, pancreatic insufficiency, and male infertility. Therapies aimed at restoring the CFTR defect have emerged. Thus, a small molecule which facilitates chloride channel opening, the potentiator Ivacaftor, has been approved for the treatment of CF patients bearing a particular class of rare CFTR mutations. However, small molecules that directly target the most common misfolded CFTR mutant, F508del, and improve its intracellular trafficking in vitro, have been less effective than expected when tested in CF patients, even in combination with Ivacaftor. Thus, new strategies are required to circumvent the F508del-CFTR defect. Airway and intestinal epithelial cells from CF patients bearing the F508del-CFTR mutation exhibit an impressive derangement of cellular proteostasis, with oxidative stress, overactivation of the tissue transglutaminase (TG2), and disabled autophagy. Proteostasis regulators such as cysteamine can rescue and stabilize a functional F508del-CFTR protein through suppressing TG2 activation and restoring autophagy in vivo in F508del-CFTR homozygous mice, in vitro in CF patient-derived cell lines, ex vivo in freshly collected primary patient's nasal cells, as well as in a pilot clinical trial involving homozygous F508del-CFTR patients. Here, we discuss how the therapeutic normalization of defective proteostasis can be harnessed for the treatment of CF patients with the F508del-CFTR mutation.

Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene mutations in North Egyptian population: implications for the genetic diagnosis in Egypt.

PubMed

El-Seedy, A; Pasquet, M C; Shafiek, H; Morsi, T; Kitzis, A; Ladevèze, V

2016-11-30

Cystic fibrosis (CF) occurrence in Arab populations is not common and still remains underidentified. Furthermore, the lack of disease awareness and diagnosis facilities have mislead the identification of cystic fibrosis for decades. The knowledge about cystic fibrosis (CF) in Egypt is very limited, and a few reports have drawn attention to the existence of CF or CFTR-related disorders (CFTR-RDs) in the Egyptian population. Therefore a comprehensive genetic analysis of the CFTR gene was realized in patients of North Egypt. DNA samples of 56 Egyptian patients were screened for the CFTR gene mutations. The 27 exons and their flanking regions of the CFTR gene were amplified by PCR, using the published primer pairs, and were studied by automated direct DNA sequencing to detect disease-causing mutations. Moreover, large duplication/deletion was analysed by MLPA technique. CFTR screening revealed the identification of thirteen mutations including four novel ones: c.92G>A (p.Arg31His), c.2782G>C (p.Ala928Pro), c.3718-24G>A, c.4207A>G (p.Arg1403Gly) and nine previously reported mutations: c.454A>T (p.Met152Leu), c.902A>G (p.Tyr301Cys), c.1418delG, c.2620-15C>G, c.2997_3000delAATT, c.3154T>G (p.Phe1052Val), c.3872A>G (p.Gln1291Arg), c.3877G>A (p.Val1293Ile), c.4242+10T>C. Furthermore, eight polymorphisms were found: c.743+40A>G, c.869+11C>T, c.1408A>G, c.1584G>A, c.2562T>G, c.3870A>G, c.4272C>T, c.4389G>A. These mutations and polymorphisms were not previously described in the Egyptian population except for the c.1408A>G polymorphism. Here we demonstrate the importance of the newly discovered mutations in Egyptian patients and the presence of CF, whereas the p.Phe508del mutation is not detected. The identification of CFTR mutations will become increasingly important in undocumented populations. The current findings will help us expand the mutational spectrum of CF and establish the first panel of the CFTR gene mutations in the Egyptian population and design an appropriate strategy for future genetic diagnosis of CF.

Cystic fibrosis transmembrane conductance regulator mutations at a referral center for cystic fibrosis.

PubMed

Coutinho, Cyntia Arivabeni de Araújo Correia; Marson, Fernando Augusto de Lima; Ribeiro, Antônio Fernando; Ribeiro, José Dirceu; Bertuzzo, Carmen Silvia

2013-01-01

To determine the frequency of six mutations (F508del, G542X, G551D, R553X, R1162X, and N1303K) in patients with cystic fibrosis (CF) diagnosed, at a referral center, on the basis of abnormal results in two determinations of sweat sodium and chloride concentrations. This was a cross-sectional study involving 70 patients with CF. The mean age of the patients was 12.38 ± 9.00 years, 51.43% were female, and 94.29% were White. Mutation screening was performed with polymerase chain reaction (for F508del), followed by enzymatic digestion (for other mutations). Clinical analysis was performed on the basis of gender, age, ethnicity, pulmonary/gastrointestinal symptoms, and Shwachman-Kulczycki (SK) score. All of the patients showed pulmonary symptoms, and 8 had no gastrointestinal symptoms. On the basis of the SK scores, CF was determined to be mild, moderate, and severe in 22 (42.3%), 17 (32.7%), and 13 (25.0%) of the patients, respectively. There was no association between F508del mutation and disease severity by SK score. Of the 140 alleles analyzed, F508del mutation was identified in 70 (50%). Other mutations (G542X, G551D, R553X, R1162X, and N1303K) were identified in 12 (7.93%) of the alleles studied. In F508del homozygous patients with severe disease, the OR was 0.124 (95% CI: 0.005-0.826). In 50% of the alleles studied, the molecular diagnosis of CF was confirmed by identifying a single mutation (F508del). If we consider the analysis of the six most common mutations in the Brazilian population (including F508del), the molecular diagnosis was confirmed in 58.57% of the alleles studied.

Stem cell-derived organoids to model gastrointestinal facets of cystic fibrosis

PubMed Central

Hohwieler, Meike; Perkhofer, Lukas; Liebau, Stefan; Seufferlein, Thomas; Müller, Martin

2016-01-01

Cystic fibrosis (CF) is one of the most frequently occurring inherited human diseases caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) which lead to ample defects in anion transport and epithelial fluid secretion. Existing models lack both access to early stages of CF development and a coeval focus on the gastrointestinal CF phenotypes, which become increasingly important due increased life span of the affected individuals. Here, we provide a comprehensive overview of gastrointestinal facets of CF and the opportunity to model these in various systems in an attempt to understand and treat CF. A particular focus is given on forward-leading organoid cultures, which may circumvent current limitations of existing models and thereby provide a platform for drug testing and understanding of disease pathophysiology in gastrointestinal organs. PMID:28815024

CFTR genotype and clinical outcomes of adult patients carried as cystic fibrosis disease.

PubMed

Bonadia, Luciana Cardoso; de Lima Marson, Fernando Augusto; Ribeiro, Jose Dirceu; Paschoal, Ilma Aparecida; Pereira, Monica Corso; Ribeiro, Antonio Fernando; Bertuzzo, Carmen Silvia

2014-05-01

There are nearly 2000 cystic fibrosis transmembrane regulator (CFTR) mutations that cause cystic fibrosis (CF). These mutations are classified into six classes; on the one hand, the first three classes cause severe disease involvement in early childhood, on the other hand, the Class IV, V and VI mutations cause minor severe disease in the same age. Nowadays, with therapeutic advances in CF management and competence of pediatricians, physicians of adults have to deal with two groups of CF patients: (i) adults diagnosed in childhood with severe mutations and (ii) adults who initiated symptoms in adulthood and with Class IV, V and VI mutations. The aim of this study was to analyze adults from a clinical center, treated as CF disease, screening the CFTR genotype and evaluating the clinical characteristics. Thirty patients followed as CF disease at the University Hospital were enrolled. After a complete molecular CFTR negative screening and sweat test levels between 40 and 59mEq/L, five patients were characterized as non-CF disease and were excluded. Molecular screening was performed by CFTR gene sequencing/MLPA or by specific mutation screening. Clinical data was obtained from medical records. The patients were divided into three groups: (1) patients with Class I, II and III mutations in two CFTR alleles; (2) genotype with at least one allele of Class IV, V or VI CFTR mutations and, (3) non-identified CFTR mutation+one patient with one allele with CFTR mutation screened (Class I). There was an association of CFTR class mutation and sodium/chloride concentration in the sweat test (sodium: p=0.040; chloride: p=0.016), onset of digestive symptoms (p=0.012), lung function parameter (SpO2 - p=0.016), Bhalla score (p=0.021), age at diagnosis (p=0.008) and CF-related diabetes (p=0.029). There was an association between Pseudomonas aeruginosa chronic colonization (as clinical marker for the lung disease status) and lung impairment (FEV1% - p=0.027; Bhalla score - p=0.021), CF-related diabetes (p=0.040), chloride concentration in the sweat test (p=0.040) and chronic infection by microorganisms (Staphylococcus aureus - p=0.039; mucoid P. aeruginosa - p=0.001). There is no positive association with the status of other clinical markers and the CFTR genotype groups. For clinical association with pancreatic insufficiency (as clinical marker for digestive symptoms), no association was related. The adults with CF diagnosed by sweat test have specific clinical and genotypic characteristics, being a population that should be studied to cause better future management. Some patients treated as CF disease by clinical symptoms, showed no disease, taking into account the sweat test and complete exon sequencing/MLPA screening. Copyright © 2014. Published by Elsevier B.V.

Distribution of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Mutations in a Cohort of Patients Residing in Palestine.

PubMed

Siryani, Issa; Jama, Mohamed; Rumman, Nisreen; Marzouqa, Hiyam; Kannan, Moein; Lyon, Elaine; Hindiyeh, Musa

2015-01-01

Cystic fibrosis (CF) is an autosomal recessive inherited life-threatening disorder that causes severe damage to the lungs and the digestive system. In Palestine, mutations in the Cystic Fibrosis Transmembrane Conductance Regulator gene (CFTR) that contributes to the clinical presentation of CF are ill defined. A cohort of thirty three clinically diagnosed CF patients from twenty one different Palestinian families residing in the central and southern part of Palestine were incorporated in this study. Sweat chloride testing was performed using the Sweat Chek Conductivity Analyzer (ELITECH Group, France) to confirm the clinical diagnosis of CF. In addition, nucleic acid from the patients' blood samples was extracted and the CFTR mutation profiles were assessed by direct sequencing of the CFTR 27 exons and the intron-exon boundaries. For patient's DNA samples where no homozygous or two heterozygous CFTR mutations were identified by exon sequencing, DNA samples were tested for deletions or duplications using SALSA MLPA probemix P091-D1 CFTR assay. Sweat chloride testing confirmed the clinical diagnosis of CF in those patients. All patients had NaCl conductivity >60 mmol/l. In addition, nine different CFTR mutations were identified in all 21 different families evaluated. These mutations were c.1393-1G>A, F508del, W1282X, G85E, c.313delA, N1303K, deletion exons 17a-17b-18, deletion exons 17a-17b and Q1100P. c.1393-1G>A was shown to be the most frequent occurring mutation among tested families. We have profiled the underling mutations in the CFTR gene of a cohort of 21 different families affected by CF. Unlike other studies from the Arab countries where F508del was reported to be the most common mutation, in southern/central Palestine, the c.1393-1G>A appeared to be the most common. Further studies are needed per sample size and geographic distribution to account for other possible CFTR genetic alterations and their frequencies. Genotype/phenotype assessments are also recommended and finally carrier frequency should be ascertained.

CFTR allelic heterogeneity in Mexican patients with cystic fibrosis: implications for molecular screening.

PubMed

Chávez-Saldaña, Margarita; Yokoyama, Emiy; Lezana, José Luis; Carnevale, Alessandra; Macías, Miguel; Vigueras, Rosa M; López, Marisol; Orozco, Lorena

2010-01-01

Cystic fibrosis, the most common autosomal recessive disorder, is caused by defects in the CF transmembrane conductance regulator gene (CFTR) that encodes a chloride channel. To date, over 1,800 mutations have been described related to the causative gene of CF, showing a variable frequency among populations. In a previous extensive analysis of the CFTR locus in 97 Mexican patients, 34 different mutations (75% of CF alleles) were found using several strategies for mutation screening; however, 63% had at least an uncharacterized allele. Despite the combined technologies used, there are still a great number of unknown mutations in the Mexican population. Screening of the CFTR gene to provide additional evidence of the mutational wide spectrum responsible for CF in Mexican patients. In this study, the number of unrelated CF patients was increased to 230, 133 new cases and the 97 previously reported to include 63% with at least an uncharacterized allele. Additional tools were used to improve the detection rate of CF mutations, such as a commercial kit for 36 mutations plus a single chain conformational polymorphism method and DNA sequencing. By using a combination of these strategies we characterized 77.7% of all the CF alleles, resulting in a total of 46 different mutations detected, including the identification of 12 additional mutations (p.R334W, p.A455E, c.3120+1G > A, c.3272-26A > G, c.711+1G > T, p.Q552X, p.W1282X, c.IVS8-5T, p.R1162X and p.R347P, p.D1152H and p.T1036N). Although these 12 mutations have been reported in other populations, they have not yet been reported in Mexican patients. This report shows that Mexico has one of the widest spectra of CFTR mutations worldwide. The knowledge of the ethnic and geographic distribution of CFTR mutations in this population will allow the development of more effective methods for diagnosis and treatment.

Transcriptional Activation of Mucin by Pseudomonas aeruginosa Lipopolysaccharide in the Pathogenesis of Cystic Fibrosis Lung Disease

NASA Astrophysics Data System (ADS)

Li, Jian-Dong; Dohrman, Austin F.; Gallup, Marianne; Miyata, Susumu; Gum, James R.; Kim, Young S.; Nadel, Jay A.; Prince, Alice; Basbaum, Carol B.

1997-02-01

An unresolved question in cystic fibrosis (CF) research is how mutations of the CF transmembrane conductance regulator, a CI ion channel, cause airway mucus obstruction leading to fatal lung disease. Recent evidence has linked the CF transmembrane conductance regulator mutation to the onset and persistence of Pseudomonas aeruginosa infection in the airways, and here we provide evidence directly linking P. aeruginosa infection to mucus overproduction. We show that P. aeruginosa lipopolysaccharide profoundly upregulates transcription of the mucin gene MUC 2 in epithelial cells via inducible enhancer elements and that this effect is blocked by the tyrosine kinase inhibitors genistein and tyrphostin AG 126. These findings improve our understanding of CF pathogenesis and suggest that the attenuation of mucin production by lipopolysaccharide antagonists and tyrosine kinase inhibitors could reduce morbidity and mortality in this disease.

Diagnosing cystic fibrosis in newborn screening in Poland - 15 years of experience.

PubMed

Sands, Dorota; Zybert, Katarzyna; Mierzejewska, Ewa; Ołtarzewski, Mariusz

2015-01-01

Early diagnosis of cystic fibrosis (CF) made by the introduction of CF NBS (Cystic Fibrosis Newborn Screening) provides the opportunity to undertake preventive measures and provide treatment before the development of irreversible changes in the respiratory tract and other complications. CF NBS was conducted as a pilot programme in four Polish districts in the period 1999-2003. In 2006 CF NBS started again and was gradually extended across the country. The aim of this study was to show the evolution of the Polish CF NBS strategies and assess the diagnostic consequences of this programme. The study involved children diagnosed and treated only in the IMiD Centre. The strategy in Polish CF NBS was modified over time. Firstly, the model IRT/IRT and IRT/IRT/DNA with one mutation was implemented, which was followed by IRT/DNA with a gradually expanding number of CFTR mutations (tab. I). Newborns with positive results of CF NBS were called to the CF IMiD Centre, and sweat tests were performed. The children diagnosed and children with mutations in both alleles of the CFTR gene even if at least one of them had undefined pathogenicity) were taken under IMiD Centre care. Sensitivity, specificity and positive predictive values during subsequent stages of CF NBS were calculated (tab. III). During the 1999-2003 pilot study 444 063 newborns underwent CF NBS and in 74 cases CF was diagnosed. 582 693 newborns were screened from September 2006 to December 2011 in four regions and 100 children were diagnosed with CF. The frequencies of CF in the Polish population in both screening periods were 1:5767 and 1:5712 respectively. Firstly, the IRT/IRT model was implemented, but the number of newborns called to the CF Centre was high - the PPV was 7.6%. In the next step CF NBS DNA analysis was used. Here sensitivity and specificity were high - nearly 100%. In the following years the number of mutations detected was expanded (including 16 most common ones in the Polish population). Due to the panel changes, the number of calls declined and the PPV (predictive positive value) improved (to 26.1%) after the application of expanded genetic analysis. Expanding the panel of mutations resulted in an increased number of carriers and observational subjects. IRT/DNA strategy with expanded DNA analysis provides the opportunity for earlier CF diagnosis even in children with normal sweat test values. However, this model caused frequent carrier detection and inconclusive diagnosis in comparison to IRT/IRT or IRT/IRT/DNA with a limited number of mutations. Further research and changes in Polish CF NBS are needed to increase the PPV, while preserving high sensitivity and specificity..

Diagnosis of Adult Patients with Cystic Fibrosis.

PubMed

Nick, Jerry A; Nichols, David P

2016-03-01

The diagnosis of cystic fibrosis (CF) is being made with increasing frequency in adults. Patients with CF diagnosed in adulthood typically present with respiratory complaints, and often have recurrent or chronic airway infection. At the time of initial presentation individuals may appear to have clinical manifestation limited to a single organ, but with subclinical involvement of the respiratory tract. Adult-diagnosed patients have a good response to CF center care, and newly available cystic fibrosis transmembrane receptor-modulating therapies are promising for the treatment of residual function mutation, thus increasing the importance of the diagnosis in adults with unexplained bronchiectasis. Copyright © 2016 Elsevier Inc. All rights reserved.

Identification of eight novel mutations in a collaborative analysis of a part of the second transmembrane domain of the CFTR gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mercier, B.; Audrezet, M.P.; Guillermit, H.

Cystic fibrosis transmembrane conductance regulator (CFTR), the gene responsible, when mutated, for cystic fibrosis (CF), spans over 230 kb on the long arm of chromosome 7 and is composed of 27 exons. The most common mutation responsible for CF worldwide is the deletion of a phenylalanine amino acid at codon 508 in the first nucleotide-binding fold and accounts for approximately 70% of CF chromosomes studied. More than 250 other mutations have been reported through the CF Genetic Analysis Consortium. The majority of the mutations previously described lie in the two nucleotide-binding folds. To explore exhaustively other regions of the gene,more » particularly exons coding for transmembrane domains, the authors have initiated a collaborative study between different laboratories to screen 369 non-[Delta]F508 CF chromosomes of seven ethnic European populations (Belgian, French, Breton, Irish, Italian, Yugoslavian, Russian). Among these chromosomes carrying an unidentified mutation, 63 were from Brittany, 50 of various French origin, 45 of Irish origin, 56 of Italian origin, 41 of Belgian origin, 2 of Turkish origin, 38 of Yugoslavian origin, 22 of Russian origin, and 52 of Bulgarian origin. Diagnostic criteria for CF included at least one positive sweat test and pulmonary disease with or without pancreatic disease. Using a denaturing gradient gel electrophoresis (DGGE) assay, they have identified eight novel mutations in exon 17b coding for part of the second transmembrane domain of the CFTR and they describe them in this report. 8 refs., 1 fig., 1 tab.« less

Preimplantation genetic diagnosis for cystic fibrosis: the Montpellier center's 10-year experience.

PubMed

Girardet, A; Ishmukhametova, A; Willems, M; Coubes, C; Hamamah, S; Anahory, T; Des Georges, M; Claustres, M

2015-02-01

This study provides an overview of 10 years of experience of preimplantation genetic diagnosis (PGD) for cystic fibrosis (CF) in our center. Owing to the high allelic heterogeneity of CF transmembrane conductance regulator (CFTR) mutations in south of France, we have set up a powerful universal test based on haplotyping eight short tandem repeats (STR) markers together with the major mutation p.Phe508del. Of 142 couples requesting PGD for CF, 76 have been so far enrolled in the genetic work-up, and 53 had 114 PGD cycles performed. Twenty-nine cycles were canceled upon in vitro fertilization (IVF) treatment because of hyper- or hypostimulation. Of the remaining 85 cycles, a total of 493 embryos were biopsied and a genetic diagnosis was obtained in 463 (93.9%), of which 262 (without or with a single CF-causing mutation) were transferable. Twenty-eight clinical pregnancies were established, yielding a pregnancy rate per transfer of 30.8% in the group of seven couples with one member affected with CF, and 38.3% in the group of couples whose both members are carriers of a CF-causing mutation [including six couples with congenital bilateral absence of the vas deferens (CBAVD)]. So far, 25 children were born free of CF and no misdiagnosis was recorded. Our test is applicable to 98% of couples at risk of transmitting CF. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

CFTR dysfunction in cystic fibrosis and chronic obstructive pulmonary disease.

PubMed

Fernandez Fernandez, Elena; de Santi, Chiara; De Rose, Virginia; Greene, Catherine M

2018-05-11

Obstructive lung diseases such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) are causes of high morbidity and mortality worldwide. CF is a multiorgan genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and is characterized by progressive chronic obstructive lung disease. Most cases of COPD are a result of noxious particles, mainly cigarette smoke but also other environmental pollutants. Areas covered: Although the pathogenesis and pathophysiology of CF and COPD differ, they do share key phenotypic features and because of these similarities there is great interest in exploring common mechanisms and/or factors affected by CFTR mutations and environmental insults involved in COPD. Various molecular, cellular and clinical studies have confirmed that CFTR protein dysfunction is common in both the CF and COPD airways. This review provides an update of our understanding of the role of dysfunctional CFTR in both respiratory diseases. Expert Commentary: Drugs developed for people with CF to improve mutant CFTR function and enhance CFTR ion channel activity might also be beneficial in patients with COPD. A move toward personalized therapy using, for example, microRNA modulators in conjunction with CFTR potentiators or correctors, could enhance treatment of both diseases.

Evolution of the Pseudomonas aeruginosa mutational resistome in an international Cystic Fibrosis clone.

PubMed

López-Causapé, Carla; Sommer, Lea Mette; Cabot, Gabriel; Rubio, Rosa; Ocampo-Sosa, Alain A; Johansen, Helle Krogh; Figuerola, Joan; Cantón, Rafael; Kidd, Timothy J; Molin, Soeren; Oliver, Antonio

2017-07-17

Emergence of epidemic clones and antibiotic resistance development compromises the management of Pseudomonas aeruginosa cystic fibrosis (CF) chronic respiratory infections. Whole genome sequencing (WGS) was used to decipher the phylogeny, interpatient dissemination, WGS mutator genotypes (mutome) and resistome of a widespread clone (CC274), in isolates from two highly-distant countries, Australia and Spain, covering an 18-year period. The coexistence of two divergent CC274 clonal lineages was revealed, but without evident geographical barrier; phylogenetic reconstructions and mutational resistome demonstrated the interpatient transmission of mutators. The extraordinary capacity of P. aeruginosa to develop resistance was evidenced by the emergence of mutations in >100 genes related to antibiotic resistance during the evolution of CC274, catalyzed by mutator phenotypes. While the presence of classical mutational resistance mechanisms was confirmed and correlated with resistance phenotypes, results also showed a major role of unexpected mutations. Among them, PBP3 mutations, shaping up β-lactam resistance, were noteworthy. A high selective pressure for mexZ mutations was evidenced, but we showed for the first time that high-level aminoglycoside resistance in CF is likely driven by mutations in fusA1/fusA2, coding for elongation factor G. Altogether, our results provide valuable information for understanding the evolution of the mutational resistome of CF P. aeruginosa.

Guidelines for the clinical management and follow-up of infants with inconclusive cystic fibrosis diagnosis through newborn screening.

PubMed

Sermet-Gaudelus, I; Brouard, J; Audrézet, M-P; Couderc Kohen, L; Weiss, L; Wizla, N; Vrielynck, S; LLerena, K; Le Bourgeois, M; Deneuville, E; Remus, N; Nguyen-Khoa, T; Raynal, C; Roussey, M; Girodon, E

2017-12-01

Neonatal screening for cystic fibrosis (CF) can detect infants with elevated immunoreactive trypsinogen (IRT) levels and inconclusive sweat tests and/or CFTR DNA results. These cases of uncertain diagnosis are defined by (1) either the presence of at most one CF-associated cystic fibrosis transmembrane conductance regulator (CFTR) mutation with sweat chloride values between 30 and 59mmol/L or (2) two CFTR mutations with at least one of unknown pathogenic potential and a sweat chloride concentration below 60mmol/L. This encompasses various clinical situations whose progression cannot be predicted. In these cases, a sweat chloride test has to be repeated at 12 months, and if possible at 6 and 24 months of life along with extended CFTR sequencing to detect rare mutations. When the diagnosis is not definite, CFTR functional explorations may provide a better understanding of CFTR dysfunction. The initial evaluation of these infants must be conducted in dedicated CF reference centers and should include bacteriological sputum analysis, chest radiology, and fecal elastase assay. The primary care physicians in charge of these patients should be familiar with the current management of CF and should work in collaboration with CF centers. A follow-up should be performed in a CF reference center at 3, 6, and 12 months of life and every year thereafter. Any symptom indicative of CF requires immediate reevaluation of the diagnosis. These guidelines were established by the "neonatal screening and difficult diagnoses" working group of the French CF society. Their objective is to standardize the management of infants with unclear diagnosis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Cystic fibrosis liver disease - from diagnosis to risk factors.

PubMed

Ciucă, Ioana Mihaiela; Pop, Liviu; Tămaş, Liviu; Tăban, Sorina

2014-01-01

Cystic fibrosis (CF) is the most frequent monogenic genetic disease, autosomal recessive transmitted, characterized by an impressive clinical polymorphism and appreciative fatal prospective. Liver disease is the second non-pulmonary cause of death in cystic fibrosis, which, with increasing life expectancy, became an important management problem. Predisposing factors like male gender, pancreatic insufficiency, meconium ileus and severe mutation are incriminated to influence the occurrence of cystic fibrosis associated liver disease (CFLD). Our study included 174 patients with CF, monitored in the National Cystic Fibrosis Centre, Timisoara, Romania. They were routinely followed-up by clinical assessment, liver biochemical tests, ultrasound examinations and other methods like transient elastography, biopsy, in selected cases. Sixty-six patients, with median age at diagnosis 4.33 years, diagnosed with CFLD, without significant gender gap. CFLD was frequent in patients aged over eight years, with meconium ileus history, carriers of severe mutations (p=0.002). Pancreatic insufficiency, although present in 75% of patients with CFLD was not confirmed as risk factor, not male gender, in our study. CF children older than eight years, carriers of a severe genotype, with a positive history of meconium ileus, were more likely predisposed to CFLD.

Lumacaftor/ivacaftor, a novel agent for the treatment of cystic fibrosis patients who are homozygous for the F580del CFTR mutation.

PubMed

Bulloch, Marilyn N; Hanna, Cameron; Giovane, Richard

2017-10-01

Cystic Fibrosis (CF) is an autosomal recessive disease affecting up to 90,000 people worldwide. Approximately 73% of patients are homozygous for the F508del cystic fibrosis transmembrane conductance regulator [CFTR] mutation. Traditionally treatment has only included supportive care. Therefore, there is a need for safe and effective novel therapies targeting the underlying molecular defects seen with CF. Areas covered: In 2016, the Food and Drug Administration and the European Commission approved LUM/IVA (Orkambi), a CFTR modulator that includes both a CFTR corrector and potentiator, for CF patients homozygous for the F508del CFTR mutation. This article reviews the pharmacologic features, clinical efficacy, and safety of LUM/IVA and summarize the available pre-clinical and clinical data of LUM/IVA use. Expert commentary: LUM/IVA showed modest, but significant improvements from baseline in percent predicted FEV 1 (ppFEV 1 ) as well as a reduction in pulmonary exacerbations by 35% It was shown to be safe for short- and long-term use. Currently, LUM/IVA is the only oral agent in its class available and represents a milestone the development of therapies for the management of CF. Nonetheless, pharmacoeconomic data are necessary to justify its high cost before is use becomes standard of care.

Diagnostic contribution of molecular analysis of the cystic fibrosis transmembrane conductance regulator gene in patients suspected of having mild or atypical cystic fibrosis *

PubMed Central

Dal'Maso, Vinícius Buaes; Mallmann, Lucas; Siebert, Marina; Simon, Laura; Saraiva-Pereira, Maria Luiza; Dalcin, Paulo de Tarso Roth

2013-01-01

OBJECTIVE: To evaluate the diagnostic contribution of molecular analysis of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in patients suspected of having mild or atypical cystic fibrosis (CF). METHODS: This was a cross-sectional study involving adolescents and adults aged ≥ 14 years. Volunteers underwent clinical, laboratory, and radiological evaluation, as well as spirometry, sputum microbiology, liver ultrasound, sweat tests, and molecular analysis of the CFTR gene. We then divided the patients into three groups by the number of mutations identified (none, one, and two or more) and compared those groups in terms of their characteristics. RESULTS: We evaluated 37 patients with phenotypic findings of CF, with or without sweat test confirmation. The mean age of the patients was 32.5 ± 13.6 years, and females predominated (75.7%). The molecular analysis contributed to the definitive diagnosis of CF in 3 patients (8.1%), all of whom had at least two mutations. There were 7 patients (18.9%) with only one mutation and 26 patients (70.3%) with no mutations. None of the clinical characteristics evaluated was found to be associated with the genetic diagnosis. The most common mutation was p.F508del, which was found in 5 patients. The combination of p.V232D and p.F508del was found in 2 patients. Other mutations identified were p.A559T, p.D1152H, p.T1057A, p.I148T, p.V754M, p.P1290P, p.R1066H, and p.T351S. CONCLUSIONS: The molecular analysis of the CFTR gene coding region showed a limited contribution to the diagnostic investigation of patients suspected of having mild or atypical CF. In addition, there were no associations between the clinical characteristics and the genetic diagnosis. PMID:23670503

Diagnostic contribution of molecular analysis of the cystic fibrosis transmembrane conductance regulator gene in patients suspected of having mild or atypical cystic fibrosis.

PubMed

Dal'Maso, Vinícius Buaes; Mallmann, Lucas; Siebert, Marina; Simon, Laura; Saraiva-Pereira, Maria Luiza; Dalcin, Paulo de Tarso Roth

2013-01-01

To evaluate the diagnostic contribution of molecular analysis of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in patients suspected of having mild or atypical cystic fibrosis (CF). This was a cross-sectional study involving adolescents and adults aged > 14 years. Volunteers underwent clinical, laboratory, and radiological evaluation, as well as spirometry, sputum microbiology, liver ultrasound, sweat tests, and molecular analysis of the CFTR gene. We then divided the patients into three groups by the number of mutations identified (none, one, and two or more) and compared those groups in terms of their characteristics. We evaluated 37 patients with phenotypic findings of CF, with or without sweat test confirmation. The mean age of the patients was 32.5 ± 13.6 years, and females predominated (75.7%). The molecular analysis contributed to the definitive diagnosis of CF in 3 patients (8.1%), all of whom had at least two mutations. There were 7 patients (18.9%) with only one mutation and 26 patients (70.3%) with no mutations. None of the clinical characteristics evaluated was found to be associated with the genetic diagnosis. The most common mutation was p.F508del, which was found in 5 patients. The combination of p.V232D and p.F508del was found in 2 patients. Other mutations identified were p.A559T, p.D1152H, p.T1057A, p.I148T, p.V754M, p.P1290P, p.R1066H, and p.T351S. The molecular analysis of the CFTR gene coding region showed a limited contribution to the diagnostic investigation of patients suspected of having mild or atypical CF. In addition, there were no associations between the clinical characteristics and the genetic diagnosis.

Molecular Epidemiology of Mutations in Antimicrobial Resistance Loci of Pseudomonas aeruginosa Isolates from Airways of Cystic Fibrosis Patients.

PubMed

Greipel, Leonie; Fischer, Sebastian; Klockgether, Jens; Dorda, Marie; Mielke, Samira; Wiehlmann, Lutz; Cramer, Nina; Tümmler, Burkhard

2016-11-01

The chronic airway infections with Pseudomonas aeruginosa in people with cystic fibrosis (CF) are treated with aerosolized antibiotics, oral fluoroquinolones, and/or intravenous combination therapy with aminoglycosides and β-lactam antibiotics. An international strain collection of 361 P. aeruginosa isolates from 258 CF patients seen at 30 CF clinics was examined for mutations in 17 antimicrobial susceptibility and resistance loci that had been identified as hot spots of mutation by genome sequencing of serial isolates from a single CF clinic. Combinatorial amplicon sequencing of pooled PCR products identified 1,112 sequence variants that were not present in the genomes of representative strains of the 20 most common clones of the global P. aeruginosa population. A high frequency of singular coding variants was seen in spuE, mexA, gyrA, rpoB, fusA1, mexZ, mexY, oprD, ampD, parR, parS, and envZ (amgS), reflecting the pressure upon P. aeruginosa in lungs of CF patients to generate novel protein variants. The proportion of nonneutral amino acid exchanges was high. Of the 17 loci, mexA, mexZ, and pagL were most frequently affected by independent stop mutations. Private and de novo mutations seem to play a pivotal role in the response of P. aeruginosa populations to the antimicrobial load and the individual CF host. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

[Frequency of the most common mutations of the CFTR gene in peruvian patients with cystic fibrosis using the ARMS-PCR technique].

PubMed

Aquino, Ruth; Protzel, Ana; Rivera, Juan; Abarca, Hugo; Dueñas, Milagros; Nestarez, Cecilia; Purizaga, Nestor; Diringer, Benoit

2017-01-01

To determine the frequency of the ten most common mutations of the CFTR gene reported in Latin Americausing amplification-refractory mutation system-polymerase chain reaction (ARMS-PCR) in patients with cystic fibrosis (CF) in two referral hospitals in Peru during the year 2014. The frequency of the ten most common mutations of the CFTR gene was assessed in patients of the Hospital Nacional Edgardo Rebagliati Martins and the Instituto Nacional de Salud del Niño, both located in Lima, Peru. Blood samples were collected from 36 patients with CF, and the ARMS-PCR technique was used to determine the presence of these mutations. The study group included 73.5% of patients with a known diagnosis of CF in the country when the study was carried out. ARMS-PCR allowed three of the mutations to be identified in a combined 30.6% of the alleles from patients with CF, and 64.9% of the mutated alleles were not identified. The mutations found were p.Phe508del (22,2%), p.Gly542* (6,9%), and p.Arg1162* (1,4%). There is significant variability in both the frequency and type of mutations present in our study population and in what has been reported in other Latin American countries. It is necessary to perform studies that use complete sequencing technology for the CFTR gene to identify other mutations present in our population.

Cysteamine re-establishes the clearance of Pseudomonas aeruginosa by macrophages bearing the cystic fibrosis-relevant F508del-CFTR mutation.

PubMed

Ferrari, Eleonora; Monzani, Romina; Villella, Valeria R; Esposito, Speranza; Saluzzo, Francesca; Rossin, Federica; D'Eletto, Manuela; Tosco, Antonella; De Gregorio, Fabiola; Izzo, Valentina; Maiuri, Maria C; Kroemer, Guido; Raia, Valeria; Maiuri, Luigi

2017-01-12

Cystic fibrosis (CF), the most common lethal monogenic disease in Caucasians, is characterized by recurrent bacterial infections and colonization, mainly by Pseudomonas aeruginosa, resulting in unresolved airway inflammation. CF is caused by mutations in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which functions as a chloride channel in epithelial cells, macrophages, and other cell types. Impaired bacterial handling by macrophages is a feature of CF airways, although it is still debated how defective CFTR impairs bacterial killing. Recent evidence indicates that a defective autophagy in CF macrophages leads to alterations of bacterial clearance upon infection. Here we use bone marrow-derived macrophages from transgenic mice to provide the genetic proof that defective CFTR compromises both uptake and clearance of internalized Pseudomonas aeruginosa. We demonstrate that the proteostasis regulator cysteamine, which rescues the function of the most common F508del-CFTR mutant and hence reduces lung inflammation in CF patients, can also repair the defects of CF macrophages, thus restoring both bacterial internalization and clearance through a process that involves upregulation of the pro-autophagic protein Beclin 1 and re-establishment of the autophagic pathway. Altogether these results indicate that cysteamine restores the function of several distinct cell types, including that of macrophages, which might contribute to its beneficial effects on CF.

Cysteamine re-establishes the clearance of Pseudomonas aeruginosa by macrophages bearing the cystic fibrosis-relevant F508del-CFTR mutation

PubMed Central

Ferrari, Eleonora; Monzani, Romina; Villella, Valeria R; Esposito, Speranza; Saluzzo, Francesca; Rossin, Federica; D'Eletto, Manuela; Tosco, Antonella; De Gregorio, Fabiola; Izzo, Valentina; Maiuri, Maria C; Kroemer, Guido; Raia, Valeria; Maiuri, Luigi

2017-01-01

Cystic fibrosis (CF), the most common lethal monogenic disease in Caucasians, is characterized by recurrent bacterial infections and colonization, mainly by Pseudomonas aeruginosa, resulting in unresolved airway inflammation. CF is caused by mutations in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which functions as a chloride channel in epithelial cells, macrophages, and other cell types. Impaired bacterial handling by macrophages is a feature of CF airways, although it is still debated how defective CFTR impairs bacterial killing. Recent evidence indicates that a defective autophagy in CF macrophages leads to alterations of bacterial clearance upon infection. Here we use bone marrow-derived macrophages from transgenic mice to provide the genetic proof that defective CFTR compromises both uptake and clearance of internalized Pseudomonas aeruginosa. We demonstrate that the proteostasis regulator cysteamine, which rescues the function of the most common F508del-CFTR mutant and hence reduces lung inflammation in CF patients, can also repair the defects of CF macrophages, thus restoring both bacterial internalization and clearance through a process that involves upregulation of the pro-autophagic protein Beclin 1 and re-establishment of the autophagic pathway. Altogether these results indicate that cysteamine restores the function of several distinct cell types, including that of macrophages, which might contribute to its beneficial effects on CF. PMID:28079883

Small-scale high-throughput sequencing-based identification of new therapeutic tools in cystic fibrosis.

PubMed

Bonini, Jennifer; Varilh, Jessica; Raynal, Caroline; Thèze, Corinne; Beyne, Emmanuelle; Audrezet, Marie-Pierre; Ferec, Claude; Bienvenu, Thierry; Girodon, Emmanuelle; Tuffery-Giraud, Sylvie; Des Georges, Marie; Claustres, Mireille; Taulan-Cadars, Magali

2015-10-01

Although 97-99% of CFTR mutations have been identified, great efforts must be made to detect yet-unidentified mutations. We developed a small-scale next-generation sequencing approach for reliably and quickly scanning the entire gene, including noncoding regions, to identify new mutations. We applied this approach to 18 samples from patients suffering from cystic fibrosis (CF) in whom only one mutation had hitherto been identified. Using an in-house bioinformatics pipeline, we could rapidly identify a second disease-causing CFTR mutation for 16 of 18 samples. Of them, c.1680-883A>G was found in three unrelated CF patients. Analysis of minigenes and patients' transcripts showed that this mutation results in aberrantly spliced transcripts because of the inclusion of a pseudoexon. It is located only three base pairs from the c.1680-886A>G mutation (1811+1.6kbA>G), the fourth most frequent mutation in southwestern Europe. We next tested the effect of antisense oligonucleotides targeting splice sites on these two mutations on pseudoexon skipping. Oligonucleotide transfection resulted in the restoration of the full-length, in-frame CFTR transcript, demonstrating the effect of antisense oligonucleotide-induced pseudoexon skipping in CF. Our data confirm the importance of analyzing noncoding regions to find unidentified mutations, which is essential to designing targeted therapeutic approaches.

Cystic Fibrosis in the African Diaspora.

PubMed

Stewart, Cheryl; Pepper, Michael S

2017-01-01

Identifying mutations that cause cystic fibrosis (CF) is important for making an early, unambiguous diagnosis, which, in turn, is linked to better health and a greater life expectancy. In patients of African descent, a molecular diagnosis is often confounded by the fact that the majority of investigations undertaken to identify causative mutations have been conducted on European populations, and CF-causing mutations tend to be population specific. We undertook a survey of published data with the aim of identifying causative CF mutations in patients of African descent in the Americas. We found that 1,584 chromosomes had been tested in only 6 countries, of which 876 alleles (55.3%) still remained unidentified. There were 59 mutations identified. Of those, 41 have been shown to cause CF, 17 have no associated functional studies, and one (R117H) is of varying clinical consequence. The most common mutations identified in the patients of African descent were: ΔF508 (29.4% identified in the United States, Colombia, Brazil, and Venezuela); 3120 + 1G>A (8.4% identified in Brazil, the United States, and Colombia); G85E (3.8% identified in Brazil); 1811 + 1.6kbA>G (3.7% identified in Colombia); and 1342 - 1G>C (3.1% identified in the United States). The majority of the mutations identified (81.4%) have been described in just one country. Our findings indicate that there is a need to fully characterize the spectrum of CF mutations in the diaspora to improve diagnostic accuracy for these patients and facilitate treatment.

Cystic fibrosis: terminology and diagnostic algorithms

PubMed Central

De Boeck, K; Wilschanski, M; Castellani, C; Taylor, C; Cuppens, H; Dodge, J; Sinaasappel, M

2006-01-01

There is great heterogeneity in the clinical manifestations of cystic fibrosis (CF). Some patients may have all the classical manifestations of CF from infancy and have a relatively poor prognosis, while others have much milder or even atypical disease manifestations and still carry mutations on each of the CFTR genes. It is important to distinguish between these categories of patients. The European Diagnostic Working Group proposes the following terminology. Patients are diagnosed with classic or typical CF if they have one or more phenotypic characteristics and a sweat chloride concentration of >60 mmol/l. The vast majority of CF patients fall into this category. Usually one established mutation causing CF can be identified on each CFTR gene. Patients with classic CF can have exocrine pancreatic insufficiency or pancreatic sufficiency. The disease can have a severe course with rapid progression of symptoms or a milder course with very little deterioration over time. Patients with non‐classic or atypical CF have a CF phenotype in at least one organ system and a normal (<30 mmol/l) or borderline (30–60 mmol/l) sweat chloride level. In these patients confirmation of the diagnosis of CF requires detection of one disease causing mutation on each CFTR gene or direct quantification of CFTR dysfunction by nasal potential difference measurement. Non‐classic CF includes patients with multiorgan or single organ involvement. Most of these patients have exocrine pancreatic sufficiency and milder lung disease. Algorithms for a structured diagnostic process are proposed. PMID:16384879

Cystic fibrosis: terminology and diagnostic algorithms.

PubMed

De Boeck, K; Wilschanski, M; Castellani, C; Taylor, C; Cuppens, H; Dodge, J; Sinaasappel, M

2006-07-01

There is great heterogeneity in the clinical manifestations of cystic fibrosis (CF). Some patients may have all the classical manifestations of CF from infancy and have a relatively poor prognosis, while others have much milder or even atypical disease manifestations and still carry mutations on each of the CFTR genes. It is important to distinguish between these categories of patients. The European Diagnostic Working Group proposes the following terminology. Patients are diagnosed with classic or typical CF if they have one or more phenotypic characteristics and a sweat chloride concentration of >60 mmol/l. The vast majority of CF patients fall into this category. Usually one established mutation causing CF can be identified on each CFTR gene. Patients with classic CF can have exocrine pancreatic insufficiency or pancreatic sufficiency. The disease can have a severe course with rapid progression of symptoms or a milder course with very little deterioration over time. Patients with non-classic or atypical CF have a CF phenotype in at least one organ system and a normal (<30 mmol/l) or borderline (30-60 mmol/l) sweat chloride level. In these patients confirmation of the diagnosis of CF requires detection of one disease causing mutation on each CFTR gene or direct quantification of CFTR dysfunction by nasal potential difference measurement. Non-classic CF includes patients with multiorgan or single organ involvement. Most of these patients have exocrine pancreatic sufficiency and milder lung disease. Algorithms for a structured diagnostic process are proposed.

Molecular Mechanisms of Fluoroquinolone Resistance in Pseudomonas aeruginosa Isolates from Cystic Fibrosis Patients

PubMed Central

Jalal, Shah; Ciofu, Oana; Høiby, Niels; Gotoh, Naomasa; Wretlind, Bengt

2000-01-01

Twenty P. aeruginosa isolates were collected from six cystic fibrosis (CF) patients, aged 27 to 33, in 1994 (9 isolates) and 1997 (11 isolates) at the CF Center, Copenhagen, Denmark, and were typed by pulse-field gel electrophoresis (PFGE) or ribotyping. Five of the patients had isolates with the same PFGE or ribotyping patterns in 1997 as in 1994, and ciprofloxacin had a two- to fourfold higher MIC for the isolates collected in 1997 than those from 1994. Genomic DNA was amplified for gyrA, parC, mexR, and nfxB by PCR and sequenced. Eleven isolates had mutations in gyrA, seven isolates had mutations at codon 83 (Thr to Ile), and four isolates had mutations at codon 87 (Asp to Asn or Tyr). Sixteen isolates had mutations in nfxB at codon 82 (Arg to Leu). Increased amounts of OprN were found in six isolates and OprJ in eight isolates as determined by immunoblotting. No isolates had mutations in parC or mexR. Six isolates had mutations in efflux pumps without gyrA mutations. The average number of mutations was higher in isolates from 1997 than in those from 1994. The results also suggested that efflux resistance mechanisms are more common in isolates from CF patients than in strains from urine and wounds from non-CF patients, in which mutations in gyrA and parC dominate (S. Jalal and B. Wretlind, Microb. Drug Resist. 4:257–261, 1998). PMID:10681343

Measurement of nasal potential difference in young children with an equivocal sweat test following newborn screening for cystic fibrosis.

PubMed

Sermet-Gaudelus, Isabelle; Girodon, Emmanuelle; Roussel, Delphine; Deneuville, Eric; Bui, Stéphanie; Huet, Frédéric; Guillot, Marcel; Aboutaam, Rola; Renouil, Michel; Munck, Anne; des Georges, Marie; Iron, Albert; Thauvin-Robinet, Christel; Fajac, Isabelle; Lenoir, Gerard; Roussey, Michel; Edelman, Aleksander

2010-06-01

A challenging problem arising from cystic fibrosis (CF) newborn screening is the significant number of infants with hypertrypsinaemia (HIRT) with sweat chloride levels in the intermediate range and only one or no identified CF-causing mutations. To investigate the diagnostic value for CF of assessing CF transmembrane conductance regulator (CFTR) protein function by measuring nasal potential difference in children with HIRT. A specially designed protocol was used to assess nasal potential difference (NPD) in 23 young children with HIRT (3 months-4 years) with inconclusive neonatal screening. Results were analysed with a composite score including CFTR-dependent sodium and chloride secretion. Results were correlated with genotype after extensive genetic screening and with clinical phenotype at follow-up 3 years later. NPD was interpretable for 21 children with HIRT: 13 had NPD composite scores in the CF range. All 13 were finally found to carry two CFTR mutations. At follow-up, nine had developed a chronic pulmonary disease consistent with a CF diagnosis. The sweat test could be repeated in nine children, and six had sweat chloride values >or=60 mmol/l. Of the eight children with normal NPD scores, only two had two CFTR mutations, both wide-spectrum mutations. None had developed a CF-like lung disease at follow-up. The sweat test could be reassessed in five of these eight children and all had sweat chloride values <60 mmol/l. CF diagnosis was ruled out in six of these eight children. Evaluation of CFTR function in the nasal epithelium of young children with inconclusive results at CF newborn screening is a useful diagnostic tool for CF.

A novel donor splice site in intron 11 of the CFTR gene, created by mutation 1811 + 1.6kbA {yields} G, produces a new exon: High frequency in spanish cystic fibrosis chromosomes and association with severe phenotype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chillon, M.; Casals, T.; Gimenez, J.

1995-03-01

mRNA analysis of the cystic fibrosis transmembrane regulator (CFTR) gene in tissues of cystic fibrosis (CF) patients has allowed us to detect a cryptic exon. The new exon involves 49 base pairs between exons 11 and 12 and is due to a point mutation (1811+1.6bA{yields}G) that creates a new donor splice site in intron 11. Semiquantitative mRNA analysis showed that 1811+1.6kbA{r_arrow}G-mRNA was 5-10-fold less abundant than {triangle}F508 mRNA. Mutations 1811+1.6kbA{yields}G was found in 21 Spanish and 1 German CF chromosome(s), making it the fourth-most-frequent mutation (2%) in the Spanish population. Individuals with genotype {triangle}F508/1811+1.6kbA{yields}G have only 1%-3% of normal CFTRmore » mRNA. This loss of 97% of normal CFTR mRNA must be responsible for the pancreatic insufficiency and for the severe CF phenotype in these patients. 30 refs., 3 figs., 2 tabs.« less

Cystic fibrosis mutations in North American populations of French ancestry: Analysis of Quebec French-Canadian and Louisiana Acadian families

PubMed Central

Rozen, Rima; Schwartz, Robert H.; Hilman, Bettina C.; Stanislovitis, Pat; Horn, Glenn T.; Klinger, Katherine; Daigneault, Jocelyne; De Braekeleer, Marc; Kerem, Bat-sheva; Tsui, Lap-Chee; Fujiwara, T. Mary; Morgan, Kenneth

1990-01-01

A 3-bp deletion (ΔF508) in the cystic fibrosis (CF) gene is the mutation on the majority of CF chromosomes. We studied 112 CF families from North American populations of French ancestry: French-Canadian families referred from hospitals in three cities in Quebec and from the Saguenay-Lac St. Jean region of northeastern Quebec and Acadian families living in Louisiana. ΔF508 was present on 71%, 55%, and 70% of the CF chromosomes from the major-urban Quebec, Saguenay-Lac St. Jean, and Louisiana Acadian families, respectively. A weighted estimate of the proportion of ΔF508 in the French-Canadian patient population of Quebec was 70%. We found that 95% of the CF chromosomes with ΔF508 had D7S23 haplotype B, the most frequent haplotype on CF chromosomes. In the Saguenay-Lac St. Jean families, 86% of the CF chromosomes without ΔF508 had the B haplotype, compared with 31% for the major-urban Quebec and Louisiana Acadian families. The incidence of CF in the Saguenay-Lac St. Jean population was 1/895 live-born infants. PMID:2220803

Cystic Fibrosis Diagnosis and Newborn Screening.

PubMed

Rosenfeld, Margaret; Sontag, Marci K; Ren, Clement L

2016-08-01

The diagnosis of cystic fibrosis (CF) has evolved over the past decade as newborn screening has become universal in the United States and elsewhere. The heterogeneity of phenotypes associated with CF transmembrane conductance regulator (CFTR) dysfunction and mutations in the CFTR gene has become clearer, ranging from classic pancreatic-insufficient CF to manifestations in only 1 organ system to indeterminate diagnoses identified by newborn screening. The tools available for diagnosis have also expanded. This article reviews the newest diagnostic criteria for CF, newborn screening, prenatal screening and diagnosis, and indeterminate diagnoses in newborn-screened infants and symptomatic adults. Copyright © 2016 Elsevier Inc. All rights reserved.

Sweat chloride and immunoreactive trypsinogen in infants carrying two CFTR mutations and not affected by cystic fibrosis.

PubMed

Castellani, Carlo; Tridello, Gloria; Tamanini, Anna; Assael, Baroukh M

2017-07-01

Newborns with raised immunotrypsinogen levels who have non-pathological sweat chloride values and carry two cystic fibrosis transmembrane regulator ( CFTR ) mutations of which at least one is not acknowledged to be cystic fibrosis (CF)-causing are at risk of developing clinical manifestations consistent with CFTR-related disorders or even CF. It is not known whether newborns with similar genotypes and normal immunoreactive trypsinogen (IRT) may share the same risk. This study found that newborns with these characteristics and normal IRT have lower sweat chloride values than those with raised IRT (p=0.007). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Cystic fibrosis transmembrane conductance regulator mutations at a referral center for cystic fibrosis*

PubMed Central

Coutinho, Cyntia Arivabeni de Araújo Correia; Marson, Fernando Augusto de Lima; Ribeiro, Antônio Fernando; Ribeiro, José Dirceu; Bertuzzo, Carmen Silvia

2013-01-01

OBJECTIVE: To determine the frequency of six mutations (F508del, G542X, G551D, R553X, R1162X, and N1303K) in patients with cystic fibrosis (CF) diagnosed, at a referral center, on the basis of abnormal results in two determinations of sweat sodium and chloride concentrations. METHODS: This was a cross-sectional study involving 70 patients with CF. The mean age of the patients was 12.38 ± 9.00 years, 51.43% were female, and 94.29% were White. Mutation screening was performed with polymerase chain reaction (for F508del), followed by enzymatic digestion (for other mutations). Clinical analysis was performed on the basis of gender, age, ethnicity, pulmonary/gastrointestinal symptoms, and Shwachman-Kulczycki (SK) score. RESULTS: All of the patients showed pulmonary symptoms, and 8 had no gastrointestinal symptoms. On the basis of the SK scores, CF was determined to be mild, moderate, and severe in 22 (42.3%), 17 (32.7%), and 13 (25.0%) of the patients, respectively. There was no association between F508del mutation and disease severity by SK score. Of the 140 alleles analyzed, F508del mutation was identified in 70 (50%). Other mutations (G542X, G551D, R553X, R1162X, and N1303K) were identified in 12 (7.93%) of the alleles studied. In F508del homozygous patients with severe disease, the OR was 0.124 (95% CI: 0.005-0.826). CONCLUSIONS: In 50% of the alleles studied, the molecular diagnosis of CF was confirmed by identifying a single mutation (F508del). If we consider the analysis of the six most common mutations in the Brazilian population (including F508del), the molecular diagnosis was confirmed in 58.57% of the alleles studied. PMID:24310628

Cystic fibrosis transmembrane conductance regulator (CFTR) allelic variants relate to shifts in faecal microbiota of cystic fibrosis patients.

PubMed

Schippa, Serena; Iebba, Valerio; Santangelo, Floriana; Gagliardi, Antonella; De Biase, Riccardo Valerio; Stamato, Antonella; Bertasi, Serenella; Lucarelli, Marco; Conte, Maria Pia; Quattrucci, Serena

2013-01-01

In this study we investigated the effects of the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene variants on the composition of faecal microbiota, in patients affected by Cystic Fibrosis (CF). CFTR mutations (F508del is the most common) lead to a decreased secretion of chloride/water, and to mucus sticky secretions, in pancreas, respiratory and gastrointestinal tracts. Intestinal manifestations are underestimated in CF, leading to ileum meconium at birth, or small bowel bacterial overgrowth in adult age. Thirty-six CF patients, fasting and under no-antibiotic treatment, were CFTR genotyped on both alleles. Faecal samples were subjected to molecular microbial profiling through Temporal Temperature Gradient Electrophoresis and species-specific PCR. Ecological parameters and multivariate algorithms were employed to find out if CFTR variants could be related to the microbiota structure. Patients were classified by two different criteria: 1) presence/absence of F508del mutation; 2) disease severity in heterozygous and homozygous F508del patients. We found that homozygous-F508del and severe CF patients exhibited an enhanced dysbiotic faecal microbiota composition, even within the CF cohort itself, with higher biodiversity and evenness. We also found, by species-specific PCR, that potentially harmful species (Escherichia coli and Eubacterium biforme) were abundant in homozygous-F508del and severe CF patients, while beneficial species (Faecalibacterium prausnitzii, Bifidobacterium spp., and Eubacterium limosum) were reduced. This is the first report that establishes a link among CFTR variants and shifts in faecal microbiota, opening the way to studies that perceive CF as a 'systemic disease', linking the lung and the gut in a joined axis.

Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Allelic Variants Relate to Shifts in Faecal Microbiota of Cystic Fibrosis Patients

PubMed Central

Santangelo, Floriana; Gagliardi, Antonella; De Biase, Riccardo Valerio; Stamato, Antonella; Bertasi, Serenella; Lucarelli, Marco

2013-01-01

Introduction In this study we investigated the effects of the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene variants on the composition of faecal microbiota, in patients affected by Cystic Fibrosis (CF). CFTR mutations (F508del is the most common) lead to a decreased secretion of chloride/water, and to mucus sticky secretions, in pancreas, respiratory and gastrointestinal tracts. Intestinal manifestations are underestimated in CF, leading to ileum meconium at birth, or small bowel bacterial overgrowth in adult age. Methods Thirty-six CF patients, fasting and under no-antibiotic treatment, were CFTR genotyped on both alleles. Faecal samples were subjected to molecular microbial profiling through Temporal Temperature Gradient Electrophoresis and species-specific PCR. Ecological parameters and multivariate algorithms were employed to find out if CFTR variants could be related to the microbiota structure. Results Patients were classified by two different criteria: 1) presence/absence of F508del mutation; 2) disease severity in heterozygous and homozygous F508del patients. We found that homozygous-F508del and severe CF patients exhibited an enhanced dysbiotic faecal microbiota composition, even within the CF cohort itself, with higher biodiversity and evenness. We also found, by species-specific PCR, that potentially harmful species (Escherichia coli and Eubacterium biforme) were abundant in homozygous-F508del and severe CF patients, while beneficial species (Faecalibacterium prausnitzii, Bifidobacterium spp., and Eubacterium limosum) were reduced. Conclusions This is the first report that establishes a link among CFTR variants and shifts in faecal microbiota, opening the way to studies that perceive CF as a ‘systemic disease’, linking the lung and the gut in a joined axis. PMID:23613805

Cystic fibrosis in the Basque country: high frequency of mutation delta F508 in patients of Basque origin.

PubMed Central

Casals, T; Vázquez, C; Lázaro, C; Girbau, E; Giménez, F J; Estivill, X

1992-01-01

The Basque population is one of the oldest populations of Europe. It has been suggested that the Basques arose from a population established in western Europe during the late Paleolithic Age. The Basque language (Euskera) is a supposedly pre-Indo-European language that originates from the first settlers of Europe. The variable distribution of the major cystic fibrosis (CF) mutation (delta F508 deletion) in Europe, with higher frequencies of the mutation in northern Europe and lower frequencies in southern Europe, has suggested that the delta F508 mutation was spread by early farmers migrating from the Middle East during the Neolithic period. We have studied 45 CF families from the Basque Country, where the incidence of CF is approximately 1/4,500. The birthplaces of the parents and grandparents have been traced and are distributed according to their origin as Basque or Mixed Basque. The frequency of the delta F508 mutation in the chromosomes of Basque origin is 87%, compared with 58% in those of Mixed Basque origin. The analysis of haplotypes, both with markers closely linked to the CF gene and with intragenic markers, suggests that the delta F508 mutation was not spread by the Indo-European invasions but was already present in Europe more than 10,000 years ago, during the Paleolithic period. PMID:1370875

Genetic Expression in Cystic Fibrosis Related Bone Disease. An Observational, Transversal, Cross-Sectional Study.

PubMed

Ciuca, Ioana M; Pop, Liviu L; Rogobete, Alexandru F; Onet, Dan I; Guta-Almajan, Bogdan; Popa, Zoran; Horhat, Florin G

2016-09-01

Cystic fibrosis (CF) is the most frequent monogenic genetic disease with autosomal recessive transmission and characterized by important clinical polymorphism and significant lethal prospective. CF related bone disease occurs frequently in adults with CF. Childhood is the period of bone formation, and therefore, children are more susceptible to low bone density. Several factors like pancreatic insufficiency, hormone imbalance, and physical inactivity contribute to CF bone disease development. Revealing this would be important for prophylactic treatment against bone disease occurrence. The study was observational, transversal, with a cross-sectional design. The study included 68 children with cystic fibrosis, genotyped and monitored in the National CF Centre. At the annual assessment, besides clinical examination, biochemical evaluation for pancreatic insufficiency, and diabetes, they were evaluated for bone mineral density using dual energy X-ray absorptiometry (DXA). Twenty-six patients, aged over 10 years were diagnosed with CF bone disease, without significant gender gap. Bone disease was frequent in patients aged over 10 years with exocrine pancreatic insufficiency, carriers of severe mutations, and CF liver disease. CF carriers of a severe genotype which associates pancreatic insufficiency and CF liver disease, are more likely predisposed to low bone mineral density. Further studies should discover other significant influences in order to prevent the development of CF bone disease and an improved quality of life in cystic fibrosis children.

Stabilization of a nucleotide-binding domain of the cystic fibrosis transmembrane conductance regulator yields insight into disease-causing mutations.

PubMed

Vernon, Robert M; Chong, P Andrew; Lin, Hong; Yang, Zhengrong; Zhou, Qingxian; Aleksandrov, Andrei A; Dawson, Jennifer E; Riordan, John R; Brouillette, Christie G; Thibodeau, Patrick H; Forman-Kay, Julie D

2017-08-25

Characterization of the second nucleotide-binding domain (NBD2) of the cystic fibrosis transmembrane conductance regulator (CFTR) has lagged behind research into the NBD1 domain, in part because NBD1 contains the F508del mutation, which is the dominant cause of cystic fibrosis. Research on NBD2 has also been hampered by the overall instability of the domain and the difficulty of producing reagents. Nonetheless, multiple disease-causing mutations reside in NBD2, and the domain is critical for CFTR function, because channel gating involves NBD1/NBD2 dimerization, and NBD2 contains the catalytically active ATPase site in CFTR. Recognizing the paucity of structural and biophysical data on NBD2, here we have defined a bioinformatics-based method for manually identifying stabilizing substitutions in NBD2, and we used an iterative process of screening single substitutions against thermal melting points to both produce minimally mutated stable constructs and individually characterize mutations. We present a range of stable constructs with minimal mutations to help inform further research on NBD2. We have used this stabilized background to study the effects of NBD2 mutations identified in cystic fibrosis (CF) patients, demonstrating that mutants such as N1303K and G1349D are characterized by lower stability, as shown previously for some NBD1 mutations, suggesting a potential role for NBD2 instability in the pathology of CF. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Mutations of the cystic fibrosis gene, but not cationic trypsinogen gene, are associated with recurrent or chronic idiopathic pancreatitis.

PubMed

Ockenga, J; Stuhrmann, M; Ballmann, M; Teich, N; Keim, V; Dörk, T; Manns, M P

2000-08-01

We investigated whether mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and cationic trypsinogen gene are associated with recurrent acute, or chronic idiopathic pancreatitis. Twenty patients with idiopathic pancreatitis (11 women, nine men; mean age, 30 yr) were studied for the presence of a CFTR mutation by screening the genomic DNA for more than 30 mutations and variants in the CFTR gene. Selected mutations of the cationic trypsinogen gene were screened by Afl III restriction digestion or by a mutation-specific polymerase chain reaction (PCR). In each patient exons 1, 2, and 3 of the cationic trypsinogen gene were sequenced. Patients with a CFTR mutation underwent evaluation of further functional electrophysiological test (intestinal current measurement). No mutation of the cationic trypsinogen gene was detected. A CFTR mutation was detected in 6/20 (30.0%) patients. Three patients (15.0%) had a cystic fibrosis (CF) mutation on one chromosome (deltaF508, I336K, Y1092X), which is known to cause phenotypical severe cystic fibrosis. One patient was heterozygous for the 5T allele. In addition, two possibly predisposing CFTR variants (R75Q, 1716G-->A) were detected on four patients, one of these being a compound heterozygous for the missense mutation I336K and R75Q. No other family member (maternal I336K; paternal R75Q; sister I1336K) developed pancreatitis. An intestinal current measurement in rectum samples of patients with a CFTR mutation revealed no CF-typical constellations. CFTR mutations are associated with recurrent acute, or chronic idiopathic pancreatitis, whereas mutations of the cationic trypsinogen mutation do not appear to be a frequent pathogenetic factor.

Assessment of epithelial sodium channel variants in nonwhite cystic fibrosis patients with non-diagnostic CFTR genotypes.

PubMed

Brennan, Marie-Luise; Pique, Lynn M; Schrijver, Iris

2016-01-01

Several lines of evidence suggest a role for the epithelial sodium channel (ENaC) in cystic fibrosis (CF). The purpose of our study was to assess the contribution of genetic variants in the ENaC subunits (α, β, γ) in nonwhite CF patients in whom CFTR molecular testing has been non-diagnostic. Samples were obtained from patients who were nonwhite and whose molecular CFTR testing did not identify two mutations. Sequencing of the SCNN1A, B, and G genes was performed and variants assessed for pathogenicity and association with CF using databases, protein and splice site mutation analysis software, and literature review. We identified four nonsynonymous amino acid variants in SCNN1A, three in SCNN1B and one in SCNN1G. There was no convincing evidence of pathogenicity. Whereas all have been reported in the dbSNP database, only p.Ala334Thr, p.Val573Ile, and p.Thr663Ala in SCNN1A, p.Gly442Val in SCNN1B and p.Gly183Ser in SCNN1G were previously reported in ENaC genetic studies of CF or CF-like patients. Synonymous substitutions were also observed but novel synonymous variants were not detected. There is no conclusive association of ENaC genetic variants with CF in nonwhite CF patients. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Assessing the residual CFTR gene expression in human nasal epithelium cells bearing CFTR splicing mutations causing cystic fibrosis

PubMed Central

Masvidal, Laia; Igreja, Susana; Ramos, Maria D; Alvarez, Antoni; de Gracia, Javier; Ramalho, Anabela; Amaral, Margarida D; Larriba, Sara; Casals, Teresa

2014-01-01

The major purpose of the present study was to quantify correctly spliced CFTR transcripts in human nasal epithelial cells from cystic fibrosis (CF) patients carrying the splicing mutations c.580-1G>T (712-1G>T) and c.2657+5G>A (2789+5G>A) and to assess the applicability of this model in CFTR therapeutic approaches. We performed the relative quantification of CFTR mRNA by reverse transcription quantitative PCR (RT-qPCR) of these splicing mutations in four groups (wild type, CF-F508del controls, CF patients and CF carriers) of individuals. In addition, in vitro assays using minigene constructs were performed to evaluate the effect of a new CF complex allele c.[2657+5G>A; 2562T>G]. Ex vivo qPCR data show that the primary consequence of both mutations at the RNA level is the skipping of their neighboring exon (6 and 16, respectively). The CFTR minigenes results mimicked the ex vivo data, as exon 16 skipping is the main aberrant transcript, and the correctly spliced transcript level was observed in a similar proportion when the c.2657+5G>A mutation is present. In summary, we provide evidence that ex vivo quantitative transcripts analysis using RT/qPCR is a robust technology that could be useful for measuring the efficacy of therapeutic approaches that attempt to achieve an increase in CFTR gene expression. PMID:24129438

Orphan missense mutations in the cystic fibrosis transmembrane conductance regulator: A three-step biological approach to establishing a correlation between genotype and phenotype.

PubMed

Fresquet, Fleur; Clement, Romain; Norez, Caroline; Sterlin, Adélaïde; Melin, Patricia; Becq, Frédéric; Kitzis, Alain; Thoreau, Vincent; Bilan, Frédéric

2011-09-01

More than 1860 mutations have been found within the human cystic fibrosis transmembrane conductance regulator (CFTR) gene sequence. These mutations can be classified according to their degree of severity in CF disease. Although the most common mutations are well characterized, few data are available for rare mutations. Thus, genetic counseling is particularly difficult when fetuses or patients with CF present these orphan variations. We describe a three-step in vitro assay that can evaluate rare missense CFTR mutation consequences to establish a correlation between genotype and phenotype. By using a green fluorescent protein-tagged CFTR construct, we expressed mutated proteins in COS-7 cells. CFTR trafficking was visualized by confocal microscopy, and the cellular localization of CFTR was determined using intracellular markers. We studied the CFTR maturation process using Western blot analysis and evaluated CFTR channel activity by automated iodide efflux assays. Of six rare mutations that we studied, five have been isolated in our laboratory. The cellular and functional impact that we observed in each case was compared with the clinical data concerning the patients in whom we encountered these mutations. In conclusion, we propose that performing this type of analysis for orphan CFTR missense mutations can improve CF genetic counseling. Copyright © 2011 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Preconceptional identification of cystic fibrosis carriers in the Sardinian population: A pilot screening program.

PubMed

Coiana, Alessandra; Faa', Valeria; Carta, Daniela; Puddu, Rosalba; Cao, Antonio; Rosatelli, Maria Cristina

2011-05-01

In Sardinia the mutational spectrum of CFTR gene is well defined. A mutation detection rate of 94% can be achieved by screening for 15 CFTR mutations with a frequency higher than 0.5%. The efficiency of this molecular test suggests that Sardinians may represent a suitable population for a preconceptional screening. Five hundred couples of Sardinia descent were screened for 38 mutations using a semi-automated reverse-dot blot and PCR-gel electrophoresis assays. This mutation panel included the 15 most frequent CF alleles in Sardinia. We identified 38 CF carriers, revealing an overall frequency of 1/25 (4%). The most common CF allele was the p.Thr338Ile (T338I) (65%), followed by the p.Phe508del (F508del) (22.5%). We also identified one couple at risk and an asymptomatic female homozygote for the p.Thr338Ile allele. In spite of the low number of the couples tested, the results herein reported demonstrate the efficacy and efficiency of the preconceptional screening program and the high participation rate of the Sardinian population (99%). Copyright © 2010 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Targeted mutation screening panels expose systematic population bias in detection of cystic fibrosis risk.

PubMed

Lim, Regine M; Silver, Ari J; Silver, Maxwell J; Borroto, Carlos; Spurrier, Brett; Petrossian, Tanya C; Larson, Jessica L; Silver, Lee M

2016-02-01

Carrier screening for mutations contributing to cystic fibrosis (CF) is typically accomplished with panels composed of variants that are clinically validated primarily in patients of European descent. This approach has created a static genetic and phenotypic profile for CF. An opportunity now exists to reevaluate the disease profile of CFTR at a global population level. CFTR allele and genotype frequencies were obtained from a nonpatient cohort with more than 60,000 unrelated personal genomes collected by the Exome Aggregation Consortium. Likely disease-contributing mutations were identified with the use of public database annotations and computational tools. We identified 131 previously described and likely pathogenic variants and another 210 untested variants with a high probability of causing protein damage. None of the current genetic screening panels or existing CFTR mutation databases covered a majority of deleterious variants in any geographical population outside of Europe. Both clinical annotation and mutation coverage by commercially available targeted screening panels for CF are strongly biased toward detection of reproductive risk in persons of European descent. South and East Asian populations are severely underrepresented, in part because of a definition of disease that preferences the phenotype associated with European-typical CFTR alleles.

Ion Channel Modulators in Cystic Fibrosis.

PubMed

Gentzsch, Martina; Mall, Marcus A

2018-05-08

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and remains one of the most common life-shortening genetic diseases affecting the lung and other organs. CFTR functions as a cAMP-dependent anion channel that transports chloride and bicarbonate across epithelial surfaces and disruption of these ion transport processes plays a central role in the pathogenesis of CF. These findings provided the rationale for pharmacological modulation of ion transport, either by targeting mutant CFTR or alternative ion channels that can compensate for CFTR dysfunction, as a promising therapeutic approach. High throughput screening has supported the development of CFTR modulator compounds. CFTR correctors are designed to improve defective protein processing, trafficking and cell surface expression, whereas potentiators increase the activity of mutant CFTR at the cell surface. The approval of the first potentiator ivacaftor for the treatment of patients with specific CFTR mutations and, more recently the corrector lumacaftor in combination with ivacaftor for patients homozygous for the common F508del mutation, were major breakthroughs on the path to causal therapies for all patients with CF. In this review, we focus on recent developments and remaining challenges of CFTR-directed therapies, as well as modulators of other ion channels such as alternative chloride channels and the epithelial sodium channel (ENaC) as additional targets in CF lung disease. Further, we discuss how patient-derived precision medicine models may aid the translation of emerging next generation ion channel modulators from the laboratory to the clinic and tailor their use for optimal therapeutic benefits in individual patients with CF. Copyright © 2018. Published by Elsevier Inc.

Cystic fibrosis transmembrane conductance regulator regulates epithelial cell response to Aspergillus and resultant pulmonary inflammation.

PubMed

Chaudhary, Neelkamal; Datta, Kausik; Askin, Frederic B; Staab, Janet F; Marr, Kieren A

2012-02-01

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) alter epithelial cell (EC) interactions with multiple microbes, such that dysregulated inflammation and injury occur with airway colonization in people with cystic fibrosis (CF). Aspergillus fumigatus frequently colonizes CF airways, but it has been assumed to be an innocent saprophyte; its potential role as a cause of lung disease is controversial. To study the interactions between Aspergillus and EC, and the role of the fungus in evoking inflammatory responses. A. fumigatus expressing green fluorescent protein was developed for in vitro and in vivo models, which used cell lines and mouse tracheal EC. Fungal spores (conidia) are rapidly ingested by ECs derived from bronchial cell lines and murine tracheas, supporting a role for EC in early airway clearance. Bronchial ECs harboring CFTR mutations (ΔF508) or deletion demonstrate impaired uptake and killing of conidia, and ECs with CFTR mutation undergo more conidial-induced apoptosis. Germinated (hyphal) forms of the fungus evoke secretion of inflammatory mediators, with CFTR mutation resulting in increased airway levels of macrophage inflammatory protein 2 and KC, and higher lung monocyte chemotactic protein-1. After A. fumigatus inhalation, CFTR(-/-) mice develop exaggerated lymphocytic inflammation, mucin accumulation, and lung injury. Data demonstrate a critical role for CFTR in mediating EC responses to A. fumigatus. Results suggest that the fungus elicits aberrant pulmonary inflammation in the setting of CFTR mutation, supporting the potential role of antifungals to halt progressive CF lung disease.

Disease-modifying genetic factors in cystic fibrosis.

PubMed

Marson, Fernando A L

2018-05-01

To compile data from the past 10 years regarding the role of modifying genes in cystic fibrosis (CF). CF is a model disease for understanding of the action of modifying genes. Although it is a monogenic (CFTR) autosomal recessive disease, CF presents with wide phenotypic variability. In CF, variability occurs with different intensity among patients by each organ, being organ-specific, resulting from the mutual interaction of environmental and genetic factors, including CFTR mutations and various other genes, most of which are associated with inflammatory processes. In individuals, using precision medicine, gene modification studies have revealed individualized responses to drugs depending on particular CFTR mutations and modifying genes, most of which are alternative ion channels. Studies of modifying genes in CF allow: understanding of clinical variability among patients with the same CFTR genotype; evaluation of precision medicine; understanding of environmental and genetic effects at the organ level; understanding the involvement of genetic variants in inflammatory responses; improvements in genetic counseling; understanding the involvement of genetic variants in inflammatory responses in lung diseases, such as asthma; and understanding the individuality of the person with the disease.

The impact of a national population carrier screening program on cystic fibrosis birth rate and age at diagnosis: Implications for newborn screening.

PubMed

Stafler, Patrick; Mei-Zahav, Meir; Wilschanski, Michael; Mussaffi, Huda; Efrati, Ori; Lavie, Moran; Shoseyov, David; Cohen-Cymberknoh, Malena; Gur, Michal; Bentur, Lea; Livnat, Galit; Aviram, Micha; Alkrinawi, Soliman; Picard, Elie; Prais, Dario; Steuer, Guy; Inbar, Ori; Kerem, Eitan; Blau, Hannah

2016-07-01

Population carrier screening (PCS) has been available in Israel since 1999 and universally subsidized since 2008. We sought to evaluate its impact. A retrospective review of governmental databanks, the national CF registry and CF centers. CF rate per 100,000 live births has decreased from 14.5 in 1990 to 6 in 2011. From 2004-2011 there were 95 CF births: 22 utilized PCS; 68 (72%) had 2 known CFTR mutations; 37% were pancreatic sufficient. At diagnosis, age was 6 (0-98) months; 53/95 had respiratory symptoms, 41/95 failure to thrive and 19/95 pseudomonas. Thirty-four (36%) were Arabs and 19 (20%) orthodox Jews, compared to 20% and 8% respectively, in the general population. PCS markedly reduced CF birth rates with a shift towards milder mutations, but was often avoided for cultural reasons. As children regularly have significant disease at diagnosis, we suggest a balanced approach, utilizing both PCS and newborn screening. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Molecular genetic analysis of some mutations in the cystic fibrosis gene in Moldova: Characterization of molecular markers and their linkage to various mutations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gimbovskaya, S.D.; Kalinin, V.N.; Ivashchenko, T.E.

1994-12-01

Sixty-one patients with cystic fibrosis (CF) from Moldova were tested for mutations {Delta}F508, G551D, and R553X. Frequencies of various alleles of the repeated GATT sequence in intron 6B of the GFTR gene, their linkage to other polymorphic markers, and various mutations were determined. The frequency of occurrence of mutation {Delta}F508 was only 25%. An absolute majority of CF patients (80%) had pancreatic insufficiency. Mutations G551D and R553X were not found in our sample. Each of 31 chromosomes with mutation {Delta}F508 carry the 6-GATT allele. Most {open_quotes}non {Delta}F508{close_quotes} (78%) and normal (80%) chromosomes were marked by the 7-GATT allele. Twenty-seven {Delta}F508more » chromosomes (96.4%) belong to haplotype B6, and only one to D6. Most chromosomes with {open_quotes}non {Delta}F508{close_quotes} mutations are associated with haplotypes D7 (26.3%) and C7 (21%). In addition, a significant portion of chromosomes from this subgroup were associated with haplotypes A7 (23.7%), A6 (10.5%), and C6 (2.7%), which are not yet described for mutant chromosomes. The results obtained demonstrate that CF in Moldova is mainly associated with mutations other than {Delta}F508, G551D, and R553X. Severe forms of the disease, with pancreatic insufficiency, are more frequently caused by these mutations; moreover, our data provides strong evidence for the presence of at least seven additional CF mutations in Moldova, apart from {Delta}F508, G551D, and R553X. Some of these are probably not described.« less

Neonatal screening of cystic fibrosis: diagnostic problems with CFTR mild mutations.

PubMed

Roussey, M; Le Bihannic, A; Scotet, V; Audrezet, M P; Blayau, M; Dagorne, M; David, V; Deneuville, E; Giniès, J L; Laurans, M; Moisan-Petit, V; Rault, G; Vigneron, P; Férec, C

2007-08-01

Newborn screening (NBS) of cystic fibrosis (CF) was implemented throughout the whole of France in 2002, but it had been established earlier in three western French regions. It can reveal atypical CF with one or two known CFTR mild mutations, with an uncertain evolution. The sweat test can be normal or borderline. In Brittany, from 1989 to 2004, 196 CF cases were diagnosed (1/2885 births). The incidence of atypical CF diagnosed by NBS is 9.7% (19 from 196). The outcome of 17 (2 lost of view) has been studied, with 9 other atypical CF cases diagnosed by NBS in two other regions. The follow-up period extends from 0.25 to 19.8 years (NBS implemented in Normandy in 1980) with mean age 4.6 years. The most frequent mild mutation is R117H ISV8-7T (50%). At the time of the last visit, nutritional status is normal. All these CF patients are pancreatic sufficient. Only one patient exhibits respiratory infections, whereas 7 others have them intermittently. Two of them had intermittent Pseudomonas aeruginosa colonization at 2.8 and 6.5 years. Mean Shwachman score is 96.7, mean Brasfield score is 22.8. Eight children have had lung function tests (mean follow-up of 10 years): mean FVC was 99% of predicted, mean FEV1 101%, but one of them has FEV1 of 48%. Predicting the phenotype of these atypical CF patients remains difficult, thus complicating any genetic counselling. A regular clinical evaluation is necessary, if possible by a CF unit, because CF symptoms may appear later.

CFTR and/or pancreatitis susceptibility genes mutations as risk factors of pancreatitis in cystic fibrosis patients?

PubMed

Gaitch, Natacha; Hubert, Dominique; Gameiro, Christine; Burgel, Pierre-Régis; Houriez, Florence; Martinez, Brigitte; Honoré, Isabelle; Chapron, Jeanne; Kanaan, Reem; Dusser, Daniel; Girodon, Emmanuelle; Bienvenu, Thierry

2016-01-01

Currently, factors that promote the occurrence of pancreatitis episodes in patients affected with cystic fibrosis (CF) and pancreatic sufficiency (PS) are largely unknown. Six genes involved in pancreatitis or in ion transport into the pancreatic duct were investigated by next generation sequencing in 59 adult CF-PS patients with two identified CF mutations. Data on predisposing environmental factors were also recorded. 19 experienced at least one episode of acute pancreatitis (AP) (AP+) and 40 patients did not (AP-). No influence of environmental factor was evidenced. No specific CFTR genotype was found predictive of pancreatitis. Patients sharing the same CFTR genotype may or may not experience AP episodes. Frequent and rare missense variants were found in 78.9% patients in group AP+ and 67.5% in group AP- but a few of them were pathogenic. AP or recurrent AP (RAP) is a frequent complication in our series of adult CF-PS patients. The majority of mild CFTR mutations found in group AP+ were located in the first transmembrane region. No clear other genetic factor could be found predictive of AP/RAP. Further experiments in large homogenous cohorts of CF-PS patients, including whole genome sequencing, may identify genetic predisposing factors to pancreatitis. Copyright © 2016 IAP and EPC. Published by Elsevier B.V. All rights reserved.

Is there evidence for correct diagnosis in cystic fibrosis registries?

PubMed

Thomas, Muriel; Lemonnier, Lydie; Gulmans, Vincent; Naehrlich, Lutz; Vermeulen, François; Cuppens, Harry; Castellani, Carlo; Norek, Aleksandra; De Boeck, Kris

2014-05-01

Cystic fibrosis (CF) spans a wide spectrum. Therefore, benchmarking between registries implies comparing similar cohorts. Explore patient characteristics in Belgian (B), French (F), German (G) and Dutch (NL) registries (total N=13,122) and determine whether they fulfill predefined diagnostic criteria. Using as case definition sweat chloride >60mmol/L or 2 CFTR mutations identified, CF diagnosis was not documented in 2.8, 5.7, 6.5 and 21.6% of subjects in the F, B, NL, and G registries. Restricting CFTR mutation interpretation to 124 CF causing mutations in CFTR2, these numbers rose to 10.5, 10.4, 14.5 and 24.3% respectively. Excluding these subjects impacted on outcomes. The impact differed between countries; the largest changes seen were a decrease in % adults from 51.9 to 47.8% in G, a decrease in % pancreas sufficiency from 17.0 to 13.0 in F, an increase in % homozygous for F508del from 55.3 to 63.7 in NL and a decrease of % with sweat chloride ≤60mmol/L from 8.4 to 1.1 in B. CF diagnosis is not documented in 10 to 24% of patients included in CF registries. Excluding these patients for analyses leads to significant changes in outcomes. © 2013.

Short communication: novel truncating mutations in the CFTR gene causing a severe form of cystic fibrosis in Italian patients.

PubMed

Lenarduzzi, S; Morgutti, M; Crovella, S; Coiana, A; Rosatelli, M C

2014-11-14

Cystic fibrosis (CF) is a common recessive genetic disease caused by mutations in the gene encoding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. More than 1800 different mutations have been described to date. Here, we report 3 novel mutations in CFTR in 3 Italian CF patients. To detect and identify 36 frequent mutations in Caucasians, we used the INNO-LiPA CFTR19 and INNO-LiPA CFTR17+Tn Update kits (Innogenetics; Ghent, Belgium). Our first analysis did not reveal both of the responsible mutations; thus, direct sequencing of the CFTR gene coding region was performed. The 3 patients were compound heterozygous. In one allele, the F508del (c.1521_1523delCTT, p.PHE508del) mutation in exon 11 was observed in each case. For the second allele, in patient No.1, direct sequencing revealed an 11-base pair deletion (GAGGCGATACT) in exon 14 (c.2236_2246del; pGlu746Alafs*29). In patient No. 2, direct sequencing revealed a nonsense mutation at nucleotide 3892 (c.3892G>T) in exon 24. In patient No. 3, direct sequencing revealed a deletion of cytosine in exon 27 (c.4296delC; p.Asn1432Lysfs*16). These 3 novel mutations indicate the production of a truncated protein, which consequently results in a non-functional polypeptide.

Mutations of Cystic Fibrosis Transmembrane Conductance Regulator Gene Cause a Monocyte-Selective Adhesion Deficiency.

PubMed

Sorio, Claudio; Montresor, Alessio; Bolomini-Vittori, Matteo; Caldrer, Sara; Rossi, Barbara; Dusi, Silvia; Angiari, Stefano; Johansson, Jan E; Vezzalini, Marzia; Leal, Teresinha; Calcaterra, Elisa; Assael, Baroukh M; Melotti, Paola; Laudanna, Carlo

2016-05-15

Cystic fibrosis (CF) is a common genetic disease caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Persistent lung inflammation, characterized by increasing polymorphonuclear leukocyte recruitment, is a major cause of the decline in respiratory function in patients with CF and is a leading cause of morbidity and mortality. CFTR is expressed in various cell types, including leukocytes, but its involvement in the regulation of leukocyte recruitment is unknown. We evaluated whether CF leukocytes might present with alterations in cell adhesion and migration, a key process governing innate and acquired immune responses. We used ex vivo adhesion and chemotaxis assays, flow cytometry, immunofluorescence, and GTPase activity assays in this study. We found that chemoattractant-induced activation of β1 and β2 integrins and of chemotaxis is defective in mononuclear cells isolated from patients with CF. In contrast, polymorphonuclear leukocyte adhesion and chemotaxis were normal. The functionality of β1 and β2 integrins was restored by treatment of CF monocytes with the CFTR-correcting drugs VRT325 and VX809. Moreover, treatment of healthy monocytes with the CFTR inhibitor CFTR(inh)-172 blocked integrin activation by chemoattractants. In a murine model of lung inflammation, we found that integrin-independent migration of CF monocytes into the lung parenchyma was normal, whereas, in contrast, integrin-dependent transmigration into the alveolar space was impaired. Finally, signal transduction analysis showed that, in CF monocytes, chemoattractant-triggered activation of RhoA and CDC42 Rho small GTPases (controlling integrin activation and chemotaxis, respectively) was strongly deficient. Altogether, these data highlight the critical regulatory role of CFTR in integrin activation by chemoattractants in monocytes and identify CF as a new, cell type-selective leukocyte adhesion deficiency disease, providing new insights into CF pathogenesis.

A G542X cystic fibrosis mouse model for examining nonsense mutation directed therapies.

PubMed

McHugh, Daniel R; Steele, Miarasa S; Valerio, Dana M; Miron, Alexander; Mann, Rachel J; LePage, David F; Conlon, Ronald A; Cotton, Calvin U; Drumm, Mitchell L; Hodges, Craig A

2018-01-01

Nonsense mutations are present in 10% of patients with CF, produce a premature termination codon in CFTR mRNA causing early termination of translation, and lead to lack of CFTR function. There are no currently available animal models which contain a nonsense mutation in the endogenous Cftr locus that can be utilized to test nonsense mutation therapies. In this study, we create a CF mouse model carrying the G542X nonsense mutation in Cftr using CRISPR/Cas9 gene editing. The G542X mouse model has reduced Cftr mRNA levels, demonstrates absence of CFTR function, and displays characteristic manifestations of CF mice such as reduced growth and intestinal obstruction. Importantly, CFTR restoration is observed in G542X intestinal organoids treated with G418, an aminoglycoside with translational readthrough capabilities. The G542X mouse model provides an invaluable resource for the identification of potential therapies of CF nonsense mutations as well as the assessment of in vivo effectiveness of these potential therapies targeting nonsense mutations.

Prenatal diagnosis in a cystic fibrosis family: a combined molecular strategy for a precise diagnosis.

PubMed

Chávez-Saldaña, Margarita; García-Cavazos, Ricardo; Vigueras, Rosa María; Orozco, Lorena

2011-01-01

The high genetic heterogeneity in populations with a wide spectrum of mutations in the CF transmembrane conductance regulator gene (CFTR), makes the detection of mutations a very hard and difficult task, thereby limiting the accurate diagnosis of the disease, mainly in patients with uncharacterized mutations. Molecular strategies, like targeted identification of the most frequent CFTR mutations in Mexican population combined with linkage analysis using markers, is very useful for carrier detection and for prenatal diagnosis in affected families with CF. In this paper we show that the combination of methodologies was a crucial alternative to reach a precise prenatal CF diagnosis. We documented CF diagnosis in a 14th-week fetus combining the screening of the most common mutations in Mexican population with linkage analysis of two extragenic polymorphisms (XV2C/TaqI and KM19/PstI). We determined that the fetus inherited the PG542X mutation from its mother and an unknown mutation from its father through the chromosomal phases analysis.

Multilocus amplicon sequencing of Pseudomonas aeruginosa cystic fibrosis airways isolates collected prior to and after early antipseudomonal chemotherapy.

PubMed

Fischer, Sebastian; Greipel, Leonie; Klockgether, Jens; Dorda, Marie; Wiehlmann, Lutz; Cramer, Nina; Tümmler, Burkhard

2017-05-01

Early antimicrobial chemotherapy can prevent or at least delay chronic cystic fibrosis (CF) airways infections with Pseudomonas aeruginosa. During a 10-year study period P. aeruginosa was detected for the first time in 54 CF patients regularly seen at the CF centre Hannover. Amplicon sequencing of 34 loci of the P. aeruginosa core genome was performed in baseline and post-treatment isolates of the 15 CF patients who had remained P. aeruginosa - positive after the first round of antipseudomonal chemotherapy. Deep sequencing uncovered coexisting alternative nucleotides at in total 33 of 55,284 examined genome positions including six non-synonymous polymorphisms in the lasR gene, a key regulator of quorum sensing. After early treatment 42 of 50 novel nucleotide substitutions had emerged in exopolysaccharide biosynthesis, efflux pump and porin genes. Early treatment selects pathoadaptive mutations in P. aeruginosa that are typical for chronic infections of CF lungs. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Rescue of CF airway epithelial cell function in vitro by a CFTR potentiator, VX-770

PubMed Central

Van Goor, Fredrick; Hadida, Sabine; Grootenhuis, Peter D. J.; Burton, Bill; Cao, Dong; Neuberger, Tim; Turnbull, Amanda; Singh, Ashvani; Joubran, John; Hazlewood, Anna; Zhou, Jinglan; McCartney, Jason; Arumugam, Vijayalaksmi; Decker, Caroline; Yang, Jennifer; Young, Chris; Olson, Eric R.; Wine, Jeffery J.; Frizzell, Raymond A.; Ashlock, Melissa; Negulescu, Paul

2009-01-01

Cystic fibrosis (CF) is a fatal genetic disease caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR), a protein kinase A (PKA)-activated epithelial anion channel involved in salt and fluid transport in multiple organs, including the lung. Most CF mutations either reduce the number of CFTR channels at the cell surface (e.g., synthesis or processing mutations) or impair channel function (e.g., gating or conductance mutations) or both. There are currently no approved therapies that target CFTR. Here we describe the in vitro pharmacology of VX-770, an orally bioavailable CFTR potentiator in clinical development for the treatment of CF. In recombinant cells VX-770 increased CFTR channel open probability (Po) in both the F508del processing mutation and the G551D gating mutation. VX-770 also increased Cl− secretion in cultured human CF bronchial epithelia (HBE) carrying the G551D gating mutation on one allele and the F508del processing mutation on the other allele by ≈10-fold, to ≈50% of that observed in HBE isolated from individuals without CF. Furthermore, VX-770 reduced excessive Na+ and fluid absorption to prevent dehydration of the apical surface and increased cilia beating in these epithelial cultures. These results support the hypothesis that pharmacological agents that restore or increase CFTR function can rescue epithelial cell function in human CF airway. PMID:19846789

Novel short chain fatty acids restore chloride secretion in cystic fibrosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Toan D.; Kim, Ug-Sung; Perrine, Susan P.

2006-03-31

Phenylalanine deletion at position 508 of the cystic fibrosis transmembrane conductance regulator ({delta}F508-CFTR), the most common mutation in cystic fibrosis (CF), causes a misfolded protein exhibiting partial chloride conductance and impaired trafficking to the plasma membrane. 4-Phenylbutyrate corrects defective {delta}F508-CFTR trafficking in vitro, but is not clinically efficacious. From a panel of short chain fatty acid derivatives, we showed that 2,2-dimethyl-butyrate (ST20) and {alpha}-methylhydrocinnamic acid (ST7), exhibiting high oral bioavailability and sustained plasma levels, correct the {delta}F508-CFTR defect. Pre-incubation ({>=}6 h) of CF IB3-1 airway cells with {>=}1 mM ST7 or ST20 restored the ability of 100 {mu}M forskolin tomore » stimulate an {sup 125}I{sup -} efflux. This efflux was fully inhibited by NPPB, DPC, or glibenclamide, suggesting mediation through CFTR. Partial inhibition by DIDS suggests possible contribution from an additional Cl{sup -} channel regulated by CFTR. Thus, ST7 and ST20 offer treatment potential for CF caused by the {delta}F508 mutation.« less

Diagnosis of cystic fibrosis in the kindred of an infant with CFTR-related metabolic syndrome: importance of follow-up that includes monitoring sweat chloride concentrations over time.

PubMed

Williams, Sophia N; Nussbaum, Eliezer; Chin, Terry W; Do, Paul C M; Singh, Kathryn E; Randhawa, Inderpal

2014-03-01

Newly implemented newborn screening (NBS) programs in California have resulted in a large subset of patients in whom at least two cystic fibrosis transmembrane conductance regulator (CFTR) mutations are identified, but subsequent sweat chloride analysis reveals normal or indeterminate values. These patients are diagnosed with CFTR-Related Metabolic Syndrome (CRMS). However, the natural progression and management of these patients are not clearly understood and frequently after the age of 1-year these patients are lost to follow-up with Cystic Fibrosis (CF) Centers. We present the first case of an infant who was referred to Miller Children's Hospital for a NBS positive for CF and subsequent discovery of identical mutations in six of his seven older brothers. Several siblings had positive sweat chloride results on repeat testing after the age of 3 years. We suggest the need for continued follow-up of CRMS in a CF center with diagnostic evaluation including repeat sweat chloride testing, beyond the currently recommended period. © 2013 Wiley Periodicals, Inc.

Association of a nonsense mutation (W1282X), the most common mutation in the Ashkenazi Jewish cystic fibrosis patients in Israel, with presentation of severe disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shoshani, T.; Bashan, N.; Seret, H.

1992-01-01

Only about 30% of the cystic fibrosis chromosomes in the Israeli cystic fibrosis patient populations carry the major CF mutation ({Delta}F508). Since different Jewish ethnic groups tended to live as closed isolates until recent times, high frequencies of specific mutations are expected among the remainder cystic fibrosis chromosomes of these ethnic groups. Genetic factors appear to influence the severity of the disease. It is therefore expected that different mutations will be associated with either severe or mild phenotype. Direct genomic sequencing of exons included in the two nucleotide-binding folds of the putative CFTR protein was performed on 119 Israeli cysticmore » fibrosis patients from 97 families. One sequence alteration which is expected to create a termination at residue 1282 (W1282X) was found in 63 chromosomes. Of 95 chromosomes, 57(60%) are of Ashkenazi origin. In conclusion, the W1282X mutation is the most common cystic fibrosis mutation in the Ashkenazi Jewish patient population in Israel. This nonsense mutation is associated with presentation of severe disease.« less

Prevalence of meconium ileus marks the severity of mutations of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene.

PubMed

Dupuis, Annie; Keenan, Katherine; Ooi, Chee Y; Dorfman, Ruslan; Sontag, Marci K; Naehrlich, Lutz; Castellani, Carlo; Strug, Lisa J; Rommens, Johanna M; Gonska, Tanja

2016-04-01

Meconium ileus (MI) is a perinatal complication in cystic fibrosis (CF), which is only minimally influenced by environmental factors. We derived and examined MI prevalence (MIP) scores to assess CFTR phenotype-phenotype correlation for severe mutations. MIP scores were established using a Canadian CF population (n = 2,492) as estimates of the proportion of patients with MI among all patients carrying the same CFTR mutation, focusing on patients with p.F508del as the second allele. Comparisons were made to the registries from the US CF Foundation (n = 43,432), Italy (Veneto/Trentino/Alto Adige regions) (n = 1,788), and Germany (n = 3,596). The prevalence of MI varied among the different registries (13-21%). MI was predominantly prevalent in patients with pancreatic insufficiency carrying "severe" CFTR mutations. In this severe spectrum MIP scores further distinguished between mutation types, for example, G542X (0.31) with a high, F508del (0.22) with a moderate, and G551D (0.08) with a low MIP score. Higher MIP scores were associated with more severe clinical phenotypes, such as a lower forced expiratory volume in 1 second (P = 0.01) and body mass index z score (P = 0.04). MIP scores can be used to rank CFTR mutations according to their clinical severity and provide a means to expand delineation of CF phenotypes.Genet Med 18 4, 333-340.

Forecasting the Long-Term Clinical and Economic Outcomes of Lumacaftor/Ivacaftor in Cystic Fibrosis Patients with Homozygous phe508del Mutation.

PubMed

Dilokthornsakul, Piyameth; Patidar, Mausam; Campbell, Jonathan D

2017-12-01

To forecast lifetime outcomes and cost of lumacaftor/ivacaftor combination therapy in patients with cystic fibrosis (CF) with homozygous phe508del mutation from the US payer perspective. A lifetime Markov model was developed from a US payer perspective. The model included five health states: 1) mild lung disease (percent predicted forced expiratory volume in 1 second [FEV 1 ] >70%), 2) moderate lung disease (40% ≤ FEV 1 ≤ 70%), 3) severe lung disease (FEV 1 < 40%), 4) lung transplantation, and 5) death. All inputs were derived from published literature. We estimated lumacaftor/ivacaftor's improvement in outcomes compared with a non-CF referent population as well as CF-specific mortality estimates. Lumacaftor/ivacaftor was associated with additional 2.91 life-years (95% credible interval 2.55-3.56) and additional 2.42 quality-adjusted life-years (QALYs) (95% credible interval 2.10-2.98). Lumacaftor/ivacaftor was associated with improvements in survival and QALYs equivalent to 27.6% and 20.7%, respectively, for the survival and QALY gaps between CF usual care and their non-CF peers. The incremental lifetime cost was $2,632,249. Lumacaftor/ivacaftor increased life-years and QALYs in CF patients with the homozygous phe508del mutation and moved morbidity and mortality closer to that of their non-CF peers but it came with higher cost. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Breakthrough Therapies: Cystic Fibrosis (CF) Potentiators and Correctors

PubMed Central

Solomon, George M.; Marshall, Susan G.; Ramsey, Bonnie W.; Rowe, Steven M.

2015-01-01

Cystic Fibrosis is caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene resulting in abnormal protein function. Recent advances of targeted molecular therapies and high throughput screening have resulted in multiple drug therapies that target many important mutations in the CFTR protein. In this review, we provide the latest results and current progress of CFTR modulators for the treatment of cystic fibrosis, focusing on potentiators of CFTR channel gating and Phe508del processing correctors for the Phe508del CFTR mutation. Special emphasis is placed on the molecular basis underlying these new therapies and emerging results from the latest clinical trials. The future directions for augmenting the rescue of Phe508del with CFTR modulators is also emphasized. PMID:26097168

[Dehydration and metabolic alkalosis: an unusual presentation of cystic fibrosis in an infant].

PubMed

Aranzamendi, Roberto J; Breitman, Fanny; Asciutto, Carolina; Delgado, Norma; Castaños, Claudio

2008-10-01

Cystic fibrosis (CF) may present during neonatal period with classic clinic symptoms related to the disease. The severity of the disease is multifactorial, one of the factors depends on the level of activity of the CFTR protein, which is related with the mutation type that affects the patient. An infant is presented who developed recurrent episodes of vomiting, anorexia, weight loss, dehydration and electrolyte abnormalities, such as metabolic alkalosis, hyponatremia, hypokalemia and hypochloremia. CF was diagnosed after the third episode showing an unusual and not very publicized presentation of the disease. Mutations !F 508 and 2789+5G-A were found. CF should be considered in patients of any age, but particularly in infants, presenting with anorexia, vomiting, failure to thrive, that are associated with recurrent episodes of hyponatremic hypochloremic, dehydration with metabolic alkalosis unexplained by other causes, even in the absence of respiratory or gastrointestinal symptoms or failure to thrive.

Cystic Fibrosis and the Nervous System.

PubMed

Reznikov, Leah R

2017-05-01

Cystic fibrosis (CF) is a life-shortening autosomal recessive disorder caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). CFTR is an anion channel that conducts bicarbonate and chloride across cell membranes. Although defective anion transport across epithelial cells is accepted as the basic defect in CF, many of the features observed in people with CF and organs affected by CF are modulated by the nervous system. This is of interest because CFTR expression has been reported in both the peripheral and central nervous systems, and it is well known that the transport of anions, such as chloride, greatly modulates neuronal excitability. Thus it is predicted that in CF, lack of CFTR in the nervous system affects neuronal function. Consistent with this prediction, several nervous system abnormalities and nervous system disorders have been described in people with CF and in animal models of CF. The goal of this special feature article is to highlight the expression and function of CFTR in the nervous system. Special emphasis is placed on nervous system abnormalities described in people with CF and in animal models of CF. Finally, features of CF that may be modulated by or attributed to faulty nervous system function are discussed. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Liver Disease in Cystic Fibrosis: an Update

PubMed Central

Parisi, Giuseppe Fabio; Di Dio, Giovanna; Franzonello, Chiara; Gennaro, Alessia; Rotolo, Novella; Lionetti, Elena; Leonardi, Salvatore

2013-01-01

Context Cystic fibrosis (CF) is the most widespread autosomal recessive genetic disorder that limits life expectation amongst the Caucasian population. As the median survival has increased related to early multidisciplinary intervention, other manifestations of CF have emergedespecially for the broad spectrum of hepatobiliary involvement. The present study reviews the existing literature on liver disease in cystic fibrosis and describes the key issues for an adequate clinical evaluation and management of patients, with a focus on the pathogenetic, clinical and diagnostic-therapeutic aspects of liver disease in CF. Evidence Acquisition A literature search of electronic databases was undertaken for relevant studies published from 1990 about liver disease in cystic fibrosis. The databases searched were: EMBASE, PubMed and Cochrane Library. Results CF is due to mutations in the gene on chromosome 7 that encodes an amino acidic polypeptide named CFTR (cystic fibrosis transmembrane regulator). The hepatic manifestations include particular changes referring to the basic CFTR defect, iatrogenic lesions or consequences of the multisystem disease. Even though hepatobiliary disease is the most common non-pulmonary cause ofmortalityin CF (the third after pulmonary disease and transplant complications), only about the 33%ofCF patients presents clinically significant hepatobiliary disease. Conclusions Liver disease will have a growing impact on survival and quality of life of cystic fibrosis patients because a longer life expectancy and for this it is important its early recognition and a correct clinical management aimed atdelaying the onset of complications. This review could represent an opportunity to encourage researchers to better investigate genotype-phenotype correlation associated with the development of cystic fibrosis liver disease, especially for non-CFTR genetic polymorphisms, and detect predisposed individuals. Therapeutic trials are needed to find strategies of fibrosis prevention and to avoid its progression prior to development its related complications. PMID:24171010

Advances in the Diagnosis and Management of Cystic Fibrosis in the Genomic Era.

PubMed

Wiencek, Joesph R; Lo, Stanley F

2018-06-01

Cystic fibrosis (CF) is a complex autosomal recessive disease that continues to present unique diagnostic challenges. Because CF was first described in 1938, there has been a substantial growth of genetic and phenotypic information about the disorder. During the past few years, as more evidence has become available, a consortium of international experts determined that the 2008 guidelines from the CF Foundation needed to be reviewed and updated. The goal of this review is to highlight the latest advances in CF multidisciplinary care, together with the recent updates to the 2017 CF Foundation diagnostic guidelines. Data from newborn screening programs, patient registries, clinical databases, and functional research have led to a better understanding of the CF transmembrane conductance regulator ( CFTR ) gene. Recent consensus guidelines have provided recommendations for clinicians and laboratorians to better assist with interpretation of disease status and related CF mutations. The highly recommended Clinical and Functional Translation of CFTR project should be the first resource in the evaluation of disease severity for CF mutations. Screen-positive newborns and patients with high clinical suspicion for CF are always recommended to undergo confirmatory sweat chloride testing with interpretations based on updated reference intervals. Every patient diagnosed with CF should receive genotyping, as novel molecular therapies are becoming standard of practice. The future of CF management must consider healthcare system disparities as CF transitions from a historically childhood disease to a predominantly adult epidemic. © 2018 American Association for Clinical Chemistry.

Prevalence and characterization of azole-resistant Aspergillus fumigatus in patients with cystic fibrosis: a prospective multicentre study in Germany.

PubMed

Seufert, R; Sedlacek, L; Kahl, B; Hogardt, M; Hamprecht, A; Haase, G; Gunzer, F; Haas, A; Grauling-Halama, S; MacKenzie, C R; Essig, A; Stehling, F; Sutharsan, S; Dittmer, S; Killengray, D; Schmidt, D; Eskandarian, N; Steinmann, E; Buer, J; Hagen, F; Meis, J F; Rath, P-M; Steinmann, J

2018-04-19

Aspergillus fumigatus is the most prevalent filamentous fungus in the respiratory tract of patients with cystic fibrosis (CF). The aim of this prospective multicentre study was to investigate the prevalence of azole-resistant A. fumigatus (ARAF) in respiratory secretions from CF patients across Germany and to characterize ARAF isolates by phenotypic and molecular methods. Twelve tertiary care centres from Germany participated in the study. In total, 2888 A. fumigatus isolates from 961 CF patients were screened for ARAF by using azole-containing agar plates. Antifungal susceptibility testing of isolates was performed by broth microdilution according to EUCAST guidelines. Analysis of mutations mediating resistance was performed using PCR and sequencing of the cyp51A gene. Furthermore, genotyping by microsatellite PCR was performed. Of a total of 2888 A. fumigatus isolates, 101 isolates from 51 CF patients were found to be azole resistant (prevalence per patient 5.3%). The Essen centre had the highest prevalence (9.1%) followed by Munich (7.8%), Münster (6.0%) and Hannover (5.2%). Most ARAF isolates (n = 89) carried the TR34/L98H mutation followed by eight G54E/R, one TR46/Y121F/T289A and one F219S mutation. In two isolates no mutation was found. Genotyping results showed no major clustering. Forty-five percent of CF patients with ARAF had previously received azole therapy. This is the first multicentre study analysing the prevalence of ARAF isolates in German CF patients. Because of a resistance rate of up to 9%, susceptibility testing of A. fumigatus isolates from CF patients receiving antifungal treatment should be part of standard diagnostic work-up.

Screening for F508del as a first step in the molecular diagnosis of cystic fibrosis.

PubMed

Marson, Fernando Augusto de Lima; Bertuzzo, Carmen Silvia; Ribeiro, Maria Ângela Gonçalves de Oliveira; Ribeiro, Antônio Fernando; Ribeiro, José Dirceu

2013-01-01

To determine the relevance of screening for the F508del mutation of the cystic fibrosis transmembrane conductance regulator gene as a first step in the genetic diagnosis of cystic fibrosis (CF) by associating the genotype with various clinical variables. We evaluated 180 CF patients regarding the F508del mutation. The clinical data were obtained from the medical records of the patients and from interviews with their parents or legal guardians. Of the 180 patients studied, 65 (36.1%) did not carry the F508del mutation (group 0 [G0]), 67 (37.2%) were F508del heterozygous (G1), and 48 (26.7%) were F508del homozygous (G2). All three groups showed associations with the clinical variables. Homozygosis was associated with younger patients, younger age at CF diagnosis, and younger age at the first isolation of Pseudomonas aeruginosa (PA), as well as with higher prevalence of pancreatic insufficiency (PI) and non-mucoid PA (NMPA) colonization. In comparison with G1+G2 patients, G0 patients were older; first experienced clinical symptoms, digestive disease, and pulmonary disease at an older age; were older at CF diagnosis and at first PA isolation; and had a lower prevalence of PI and meconium ileus, as well as of colonization by NMPA, mucoid PA, and Burkholderia cepacia. In G1 patients, values were intermediate for age at CF diagnosis; age at first PA isolation, first pulmonary symptoms, and first clinical manifestations; MPA colonization; and OR for PI. The identification of F508del in 63.9% of the patients studied showed that this can be a useful tool as a first step in the genetic diagnosis of CF. The F508del genotype was associated with clinical severity of the disease, especially with the variables related to CF onset.

The Spectrum of CFTR Variants in Nonwhite Cystic Fibrosis Patients: Implications for Molecular Diagnostic Testing.

PubMed

Schrijver, Iris; Pique, Lynn; Graham, Steve; Pearl, Michelle; Cherry, Athena; Kharrazi, Martin

2016-01-01

Despite the implementation of cystic fibrosis (CF) newborn screening programs across the United States, the identification of CFTR gene variants in nonwhite populations compared with whites remains suboptimal. Our objective was to establish the spectrum of CFTR variants and their frequencies in CF patients in the United States with African, Native American, Asian, East Indian, or Middle Eastern backgrounds. By using direct DNA sequencing, we identified two CFTR variants in 89 of 140 affected nonwhite individuals with uncharacterized genotypes. Seven variants were novel. Multiplex ligation-dependent probe amplification detected 14 rearrangements in the remaining 51 patients, 6 of which were novel. Deletions and duplications accounted for 17% of unidentified alleles. A cross-sectional analysis of genotyping data from the CF Foundation Patient Registry was performed, comparing 3496 nonwhite patients with 22,206 white CF patients. Patients of Hispanic, black, or Asian ancestry were less likely to have two identified CFTR variants (P < 0.0001 for Hispanics and blacks, P = 0.003 for Asians), and more likely to carry no mutations on the commonly used 23 mutation carrier screening panel (P < 0.0001). We analyzed the mutations recorded for each ancestry and summarized the most frequent ones. This research could facilitate equity in mutation detection between white and nonwhite or mixed-ethnicity CF patients, enabling an earlier diagnosis improving their quality of life. Copyright © 2016 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Ataluren in cystic fibrosis: development, clinical studies and where are we now?

PubMed

Zainal Abidin, Noreen; Haq, Iram J; Gardner, Aaron I; Brodlie, Malcolm

2017-09-01

Cystic fibrosis (CF) is one of the most common genetically-acquired life-limiting conditions worldwide. The underlying defect is dysfunction of the cystic fibrosis transmembrane-conductance regulator (CFTR) which leads to progressive lung disease and other multi-system effects. Around 10% of people with CF have a class I nonsense mutation that leads to production of shortened CFTR due to a premature termination codon (PTC). Areas covered: We discuss the discovery of the small-molecule drug ataluren, which in vitro has been shown to allow read-through of PTCs and facilitate synthesis of full-length protein. We review clinical studies that have been performed involving ataluren in CF. Early-phase short-term cross-over studies showed improvement in nasal potential difference. A follow-up phase III randomised controlled trial did not show a significant difference for the primary outcome of lung function, however a post-hoc analysis suggested possible benefit in patients not receiving tobramycin. A further randomised controlled trial in patients not receiving tobramycin has been reported as showing no benefit but has not yet been published in full peer-reviewed form. Expert opinion: A small-molecule approach to facilitate read-through of PTCs in nonsense mutations makes intuitive sense. However, at present there is no high-quality evidence of clinical efficacy for ataluren in people with CF.

Genetic and clinical features of false-negative infants in a neonatal screening programme for cystic fibrosis.

PubMed

Padoan, R; Genoni, S; Moretti, E; Seia, M; Giunta, A; Corbetta, C

2002-01-01

A study was performed on the delayed diagnosis of cystic fibrosis (CF) in infants who had false-negative results in a neonatal screening programme. The genetic and clinical features of false-negative infants in this screening programme were assessed together with the efficiency of the screening procedure in the Lombardia region. In total, 774,687 newborns were screened using a two-step immunoreactive trypsinogen (IRT) (in the years 1990-1992), IRT/IRT + delF508 (1993-1998) or IRT/IRT + polymerase chain reaction (PCR) and oligonucleotide ligation assay (OLA) protocol (1998-1999). Out of 196 CF children born in the 10 y period 15 were false negative on screening (7.6%) and molecular analysis showed a high variability in the genotypes. The cystic fibrosis transmembrane regulator (CFTR) gene mutations identified were delF508, D1152H, R1066C, R334W, G542X, N1303K, F1052V, A120T, 3849 + 10kbC --> T, 2789 + 5G --> A, 5T-12TG and the novel mutation D110E. In three patients no mutation was identified after denaturing gradient gel electrophoresis of the majority of CFTR gene exons. The clinical phenotypes of CF children diagnosed by their symptoms at different ages were very mild. None of them presented with a severe lung disease. The majority of them did not seem to have been damaged by the delayed diagnosis. The combination of IRT assay plus genotype analysis (1998-1999) appears to be a more reliable method of detecting CF than IRT measurement alone or combined with only the delF508 mutation.

Activation of deltaF508 CFTR in a cystic fibrosis respiratory epithelial cell line by 4-phenylbutyrate, genistein and CPX.

PubMed

Andersson, C; Roomans, G M

2000-05-01

The cellular basis of cystic fibrosis (CF) is a defect in a cyclic adenosine monophosphate (cAMP)-activated chloride channel (CF transmembrane conductance regulator) in epithelial cells that leads to decreased chloride ion transport and impaired water transport across the cell membrane. This study investigated whether it was possible to activate the defective chloride channel in cystic fibrosis respiratory epithelial cells with 4-phenylbutyrate (4PBA), genistein and 8-cyclopentyl-1,3-dipropylxanthine (CPX). The CF bronchial epithelial cell line CFBE41o-, which expresses the deltaF508 mutation, was treated with these agents and loss of Cl-, indicating Cl- efflux, measured by X-ray microanalysis. 8-bromo-cAMP alone did not induce Cl- efflux in CFBE41o- cells, but after incubation with 4PBA a significant efflux of Cl- occurred. Stimulation of cells with a combination of genistein and cAMP also induced Cl- efflux, whereas a combination of pretreatment with 4PBA and a combined stimulation with genistein and cAMP induced an even larger Cl- efflux. Cl- efflux could also be stimulated by CPX, but this effect was not enhanced by 4PBA pretreatment. The deltaF508 mutation leads to impaired processing of the cystic fibrosis transmembrane conductance regulator. The increased efflux of chloride after 4-phenylbutyrate treatment can be explained by the fact that 4-phenylbutyrate allows the deltaF508 cystic fibrosis transmembrane conductance regulator to escape degradation and to be transported to the cell surface. Genistein and 8-cyclopentyl-1,3-dipropylxanthine act by stimulating chloride ion efflux by increasing the probability of the cystic fibrosis transmembrane conductance regulator being open. The combination of 4-phenylbutyrate and genistein may be useful in a potential pharmacological therapy for cystic fibrosis patients with the deltaF508 mutation.

Polymorphisms in the glutathione pathway modulate cystic fibrosis severity: a cross-sectional study

PubMed Central

2014-01-01

Background Cystic fibrosis (CF) clinically manifests with various levels of severity, which are thought to be modulated by mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR), modifier genes, and the environment. This study verified whether polymorphisms in modifier genes associated with glutathione (GSH) metabolism influence CF severity. Methods A cross-sectional study of 180 CF patients was carried out from 2011 to 2012. We analyzed CFTR mutations, polymorphisms (GSTM1 and GSTT1 deletions, GSTP1 + 313A > G, GCLC-129C > T, and GCLC-3506A > G) in modifier genes and CF clinical severity as assessed by 28 clinical and laboratory variables. Results Significant associations were found between modifier gene polymorphisms and particular phenotypes or genotype changes. These included GCLC-129C > T with a higher frequency of the Pseudomonas aeruginosa mucoid to CC genotype (p = 0.044), and GCLC-3506A > G with a higher frequency of the no-mucoid P. aeruginosa (NMPA) to AA genotype (p = 0.012). The GSTT1 deletion was associated with a higher frequency of the NMPA to homozygous deletion (p = 0.008), GSTP1 + 313A > G with a minor risk of osteoporosis (p = 0.036), and patient age ≤ 154 months (p = 0.044) with the AA genotype. The Bhalla score was associated with GCLC-3506A > G (p = 0.044) and GSTM1/GSTT1 deletion polymorphisms (p = 0.02), while transcutaneous hemoglobin oxygen saturation levels were associated with GSTT1 deletions (p = 0.048). Conclusion CF severity is associated with polymorphisms in GSH pathways and CFTR mutations. PMID:24593045

Cystic fibrosis research topics featured at the 14th ECFS Basic Science Conference: Chairman's summary.

PubMed

Mall, Marcus A; Hwang, Tzyh-Chang; Braakman, Ineke

2018-03-01

In recent years, tremendous progress has been made in the development of novel drugs targeting the basic defect in patients with cystic fibrosis (CF). This breakthrough is based on a solid foundation of knowledge on CFTR's function in health and how mutations in CFTR cause CF multi-organ disease. This knowledge has been collected and continuously expanded by an active and persistent CF research community and has paved the way for precision medicine for CF. Since 2004, the European Cystic Fibrosis Society (ECFS) has held an annual Basic Science Conference that has evolved as an international forum for interdisciplinary discussion of hot topics and unsolved questions related to CF research. This Special Issue reviews CF research topics featured at the 14th ECFS Basic Science Conference and provides an up-to-date overview of recent progress in our understanding of CFTR structure and function, disease mechanisms implicated in airway mucus plugging, inflammation and abnormal host-pathogen interactions, and advancements with enhanced cell and animal model systems and breakthrough therapies directed at mutant CFTR or alternative targets. In addition, this Special Issue also identifies a number of fundamental questions and hurdles that still have to be overcome to realize the full potential of precision medicine and develop transformative therapies for all patients with CF. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Computed tomography correlates with improvement with ivacaftor in cystic fibrosis patients with G551D mutation.

PubMed

Sheikh, Shahid I; Long, Frederick R; McCoy, Karen S; Johnson, Terri; Ryan-Wenger, Nancy A; Hayes, Don

2015-01-01

Ivacaftor corrects the cystic fibrosis transmembrane conductance regulator (CFTR) gating defect associated with G551D mutation and is quickly becoming an important treatment in patients with cystic fibrosis (CF) due to this genetic mutation. A single-center study was performed in CF patients receiving ivacaftor to evaluate the usefulness of high resolution computed tomography (HRCT) of the chest as a way to gauge response to ivacaftor therapy. Ten patients with CF were enrolled for at least one year before and after starting ivacaftor. At time of enrollment, mean age was 20.9 ± 10.8 (range 10-44) years. There were significant improvements from baseline to 6 months in mean %FVC (93 ± 16 to 99 ± 16) and %FEV1 (79 ± 26 to 87 ± 28) but reverted to baseline at one year. Mean sweat chloride levels decreased significantly from baseline to one year. Mean weight and BMI improved at 6 months. Weight continued to improve with stabilization of BMI at one year. Chest HRCT showed significant improvement at one year in mean modified Brody scores for bronchiectasis, mucous plugging, airway wall thickness, and total Brody scores. Elevated bronchiectasis and airway wall thickness scores correlated significantly with lower %FEV1, while higher airway wall thickness and mucus plugging scores correlated with more pulmonary exacerbations requiring IV and oral antibiotics respectively. Based on our findings, HRCT imaging is a useful tool in monitoring response to ivacaftor therapy that corrects the gating defect associated with the G551D-CFTR mutation. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

[News in cystic fibrosis].

PubMed

Delaisi, B

2013-08-01

The improvement over the last two decades in the treatment of cystic fibrosis led to an increase in life expectancy approaching 40 years at birth. Logically, the population of adult patients has been increasing and is currently 50% of patients followed in France. These therapeutic advances have justified the establishment in 2003 of a generalized neonatal screening for cystic fibrosis. The latest data of this screening show an incidence of CF of 1/5359 live births, far below the incidence of 1/2500 which was widely accepted twenty years ago. The performance of this screening is currently based on the dosage of trypsin immuno reactive, followed in case of exceeding the threshold of a search of the 30 most common mutations, can detect around 96% of 150 to 200 CF cases every year. Therefore, the possibility of a false negative of the screening cannot be excluded and evocative symptoms of cystic fibrosis, even for children born after 2003, will lead to prescribe a sweat test. While treatments available so far goal consequences of cystic fibrosis, a new therapeutic class to correct the functional defect of the mutated protein, called CFTR modulators, is emerging. Ivacaftor, leader of this new class, belonging to the category of "CFTR potentiator" got its access on the market in September 2012 for patients carrying the G551D mutation. New other molecules, named "CFTR correctors" which can have synergistic effect with ivacaftor and concern patients carrying the most common mutation--DF 508--are under development. Copyright © 2013. Published by Elsevier Masson SAS.

[Pseudo-Bartter syndrome as manifestation of cystic fibrosis with DF508 mutation].

PubMed

Galaviz-Ballesteros, María de Jesús; Acosta-Rodríguez-Bueno, Carlos Patricio; Consuelo-Sánchez, Alejandra; Franco-Álvarez, Isidro; Olalla-Mora, Odilo Iván; Vázquez-Frias, Rodrigo

Pseudo Bartter syndrome (PBS) is defined as hypokalaemic hypochloraemic metabolic alkalosis in the absence of renal tubular pathology. Children with cystic fibrosis (CF) are at risk of developing electrolyte abnormalities and even PBS may occur. 5 months old female infant with a history of two events of dehydration with vomit, refusal to eat, chronic cough, polyuria, malnutrition, metabolic alkalosis, hypokalemia, hyponatremia, hypochloremia and acute renal failure. Chronic cough study was performed, discarding pulmonary tuberculosis, gastroesophageal reflux disease and impaired swallowing. PBS was diagnosed due to hypokalaemic hypochloraemic metabolic alkalosis in the absence of renal tubular pathology. CF was corroborated by electrolytes in sweat and through molecular analysis of the delta F508 mutation. This is one of the few reported cases linking PBS and this mutation. In patients with hyponatremic dehydration episodes with hypokalaemic hypochloraemic metabolic alkalosis, PBS should be considered as differential diagnosis. CF could be presented as PBS, mainly in patients younger than 2 years. Copyright © 2016 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Cystic Fibrosis Transmembrane Conductance Regulator Regulates Epithelial Cell Response to Aspergillus and Resultant Pulmonary Inflammation

PubMed Central

Chaudhary, Neelkamal; Datta, Kausik; Askin, Frederic B.; Staab, Janet F.

2012-01-01

Rationale: Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) alter epithelial cell (EC) interactions with multiple microbes, such that dysregulated inflammation and injury occur with airway colonization in people with cystic fibrosis (CF). Aspergillus fumigatus frequently colonizes CF airways, but it has been assumed to be an innocent saprophyte; its potential role as a cause of lung disease is controversial. Objectives: To study the interactions between Aspergillus and EC, and the role of the fungus in evoking inflammatory responses. Methods: A. fumigatus expressing green fluorescent protein was developed for in vitro and in vivo models, which used cell lines and mouse tracheal EC. Measurements and Main Results: Fungal spores (conidia) are rapidly ingested by ECs derived from bronchial cell lines and murine tracheas, supporting a role for EC in early airway clearance. Bronchial ECs harboring CFTR mutations (ΔF508) or deletion demonstrate impaired uptake and killing of conidia, and ECs with CFTR mutation undergo more conidial-induced apoptosis. Germinated (hyphal) forms of the fungus evoke secretion of inflammatory mediators, with CFTR mutation resulting in increased airway levels of macrophage inflammatory protein 2 and KC, and higher lung monocyte chemotactic protein-1. After A. fumigatus inhalation, CFTR−/− mice develop exaggerated lymphocytic inflammation, mucin accumulation, and lung injury. Conclusions: Data demonstrate a critical role for CFTR in mediating EC responses to A. fumigatus. Results suggest that the fungus elicits aberrant pulmonary inflammation in the setting of CFTR mutation, supporting the potential role of antifungals to halt progressive CF lung disease. PMID:22135344

Relevance of nasal potential difference in diagnosis of cystic fibrosis among children.

PubMed

Valiulis, Arūnas; Skurvydienė, Iveta; Misevičienė, Valdonė; Kasnauskienė, Jūratė; Vaidelienė, Laimutė; Utkus, Algirdas

2013-01-01

OBJECTIVE. The aim of this study was to estimate the significance of nasal potential difference (NPD) in the diagnosis of cystic fibrosis (CF) in children with clinical symptoms suggestive of the disease, positive sweat test results, and/or genetically confirmed diagnosis. MATERIAL AND METHODS. NPD measurements according to the modifications by Alton were performed in 50 children with clinical CF symptoms supported by positive sweat test results, 50 children with other obstructive lung diseases, and 50 healthy children. A subgroup of 17 children with the diagnosis confirmed by 2 identified mutations in the CF transmembrane regulatory gene was analyzed individually. RESULTS. The mean NPD value recorded in 50 children with clinical symptoms of CF supported by positive sweat test results and/or genetic analysis was -28.0 mV [SD, 10.2]. The mean NPD value in the subgroup of children with 2 identified mutations in the CF gene (n=17) was more negative than in the subgroup of children with unrecognized mutations (n=33) (-37.1 mV [SD, 7.0] vs. -23.4 mV [SD, 8.3], P<0.001). The mean NPD value in patients with other obstructive lung diseases and healthy children was significantly more positive than in the group of CF children with positive sweat test results and/or identified mutations (-18.1 mV [SD, 3.6] and -15.5 mV [SD, 4.3] vs. -28.0 mV [SD, 10.2], P<0.001). The NPD cut point value for the genetically confirmed diagnosis of CF was -35.0 mV (sensitivity, 93.9%; specificity, 88.2%), while in general, the NPD prognostic value was -24.0 mV (sensitivity, 58.0%; specificity, 98.0%). CONCLUSIONS. The NPD measurement is a valuable tool for the diagnosis of CF in children, but further studies are necessary to establish NPD values related to the CF genotype and to reduce the intrasubject variability of this test.

Cystic Fibrosis and Its Management Through Established and Emerging Therapies.

PubMed

Spielberg, David R; Clancy, John P

2016-08-31

Cystic fibrosis (CF) is the most common life-shortening autosomal recessive disorder in the Caucasian population and occurs in many other ethnicities worldwide. The daily treatment burden is substantial for CF patients even when they are well, with numerous pharmacologic and physical therapies targeting lung disease requiring the greatest time commitment. CF treatments continue to advance with greater understanding of factors influencing long-term morbidity and mortality. In recent years, in-depth understanding of genetic and protein structure-function relationships has led to the introduction of targeted therapies for patients with specific CF genotypes. With these advances, CF has become a model of personalized or precision medicine. The near future will see greater access to targeted therapies for most patients carrying common mutations, which will mandate individualized bench-to-bedside methodologies for those with rare genotypes.

Personalized Drug Therapy in Cystic Fibrosis: From Fiction to Reality.

PubMed

de Lima Marson, Fernando Augusto; Bertuzzo, Carmen Silvia; Ribeiro, Jose Dirceu

2015-01-01

Personalized drug therapy for cystic fibrosis (CF) is a long-term dream for CF patients, caregivers, physicians and researchers. After years of study, the fiction of personalized treatment has turned to hope. Basic information about CFTR mutations classes and new treatments is needed if we are to deal properly with the new CF era. The problems involved in this issue, however, should be evaluated with greater care and attention. VX-770 is a new drug available to treat CF patients with some class III CFTR mutations and other drugs are being studied regarding other classes. The scientific literature has constantly given information about each therapy, both in vitro and in vivo. The hope is increasing. Nevertheless the "scientific world" still lacks information about patients' reality and daily health related practical needs. Clinical trials have showed good evaluation of some drugs so far, but clinical response is a wide spectrum yet to be analyzed: CFTR mutations spectrum, costs related to the treatment with new drugs (for VX-770 therapy), variability of CF clinical expression, limitations to test in vitro drugs, absence of good clinical markers to evaluate drug response, absence of long-term studies and with patients below six years old, multidrug treatment used to improve the expression response, and finally, the most important problem, who will benefit from the new drugs therapy, are issues that constitute a barrier that should be overcome. Personalized drug therapy may not be a fiction anymore, but it is not yet a reality for all CF patients.

Forecasting US ivacaftor outcomes and cost in cystic fibrosis patients with the G551D mutation.

PubMed

Dilokthornsakul, Piyameth; Hansen, Ryan N; Campbell, Jonathan D

2016-06-01

Ivacaftor, a breakthrough treatment for cystic fibrosis (CF) patients with the G551D genetic mutation, lacks long-term clinical and cost projections. This study forecasted outcomes and cost by comparing ivacaftor plus usual care versus usual care alone.A lifetime Markov model was conducted from a US payer perspective. The model consisted of five health states: 1) forced expiratory volume in 1 s (FEV1) % pred ≥70%, 2) 40%≤ FEV1 % pred <70%, 3) FEV1 % pred <40%, 4) lung transplantation and 5) death. All inputs were extracted from published literature. Budget impact was also estimated. We estimated ivacaftor's improvement in outcomes compared with a non-CF referent population.Ivacaftor was associated with 18.25 (95% credible interval (CrI) 13.71-22.20) additional life-years and 15.03 (95% CrI 11.13-18.73) additional quality-adjusted life-years (QALYs). Ivacaftor was associated with improvements in survival and QALYs equivalent to 68% and 56%, respectively, for the survival and QALY gaps between CF usual care and their non-CF peers. The incremental lifetime cost was $3 374 584. The budget impact was $0.087 per member per month.Ivacaftor increased life-years and QALYs in CF patients with the G551D mutation, and moved morbidity and mortality closer to that of their non-CF peers. Ivacaftor costs much more than usual care, but comes at a relatively limited budget impact. Copyright ©ERS 2016.

Postnatal airway growth in cystic fibrosis piglets.

PubMed

Adam, Ryan J; Abou Alaiwa, Mahmoud H; Bouzek, Drake C; Cook, Daniel P; Gansemer, Nicholas D; Taft, Peter J; Powers, Linda S; Stroik, Mallory R; Hoegger, Mark J; McMenimen, James D; Hoffman, Eric A; Zabner, Joseph; Welsh, Michael J; Meyerholz, David K; Stoltz, David A

2017-09-01

Mutations in the gene encoding the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) anion channel cause CF. The leading cause of death in the CF population is lung disease. Increasing evidence suggests that in utero airway development is CFTR-dependent and that developmental abnormalities may contribute to CF lung disease. However, relatively little is known about postnatal CF airway growth, largely because such studies are limited in humans. Therefore, we examined airway growth and lung volume in a porcine model of CF. We hypothesized that CF pigs would have abnormal postnatal airway growth. To test this hypothesis, we performed CT-based airway and lung volume measurements in 3-wk-old non-CF and CF pigs. We found that 3-wk-old CF pigs had tracheas of reduced caliber and irregular shape. Their bronchial lumens were reduced in size proximally but not distally, were irregularly shaped, and had reduced distensibility. Our data suggest that lack of CFTR results in aberrant postnatal airway growth and development, which could contribute to CF lung disease pathogenesis. NEW & NOTEWORTHY This CT scan-based study of airway morphometry in the cystic fibrosis (CF) postnatal period is unique, as analogous studies in humans are greatly limited for ethical and technical reasons. Findings such as reduced airway lumen area and irregular caliber suggest that airway growth and development are CF transmembrane conductance regulator-dependent and that airway growth defects may contribute to CF lung disease pathogenesis. Copyright © 2017 the American Physiological Society.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thibodeau, Patrick H.; Brautigam, Chad A.; Machius, Mischa

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), an integral membrane protein, cause cystic fibrosis (CF). The most common CF-causing mutant, deletion of Phe508, fails to properly fold. To elucidate the role Phe508 plays in the folding of CFTR, missense mutations at this position were generated. Only one missense mutation had a pronounced effect on the stability and folding of the isolated domain in vitro. In contrast, many substitutions, including those of charged and bulky residues, disrupted folding of full-length CFTR in cells. Structures of two mutant nucleotide-binding domains (NBDs) reveal only local alterations of the surface near positionmore » 508. These results suggest that the peptide backbone plays a role in the proper folding of the domain, whereas the side chain plays a role in defining a surface of NBD1 that potentially interacts with other domains during the maturation of intact CFTR.« less

Analysis of some polymorphic markers of the CFTR gene in cystic fibrosis patients and healthy donors from the Moscow region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amosenko, F.A.; Sazonova, M.A.; Kapranov, N.I.

1995-04-01

Allelic frequencies of three polymorphic markers in the CFTR gene were estimated on chromosomes derived from cystic fibrosis (CF) patients and healthy donors from Moscow and the Moscow region. These polymorphic markers are tetranucleotide tandem repeats GATT in intron 6B, M470V in exon 10, and T854T in exon 14 (fragment A). Frequencies at allele 1 of the M470V marker, along with allele 2 of GATT and T854T, are two times higher for CF patients without {Delta}F508 mutation than for healthy donors, and there is linkage disequilibrium of these alleles of the polymorphic markers analyzed with the CF gene. Allele 1more » of M470V and T854T markers, as well as allele 2 of the GATT marker (six repeats), are absolutely linked to mutation F508 of the CFTR gene. Using the polymorphic markers studied, family analysis of CF was carried out in two families. 10 refs., 1 fig., 1 tab.« less

Missense variations in the cystic fibrosis gene: Heteroduplex formation in the F508C mutation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macek, M. Jr.; Ladanyi, L.; Buerger, J.

1992-11-01

Kobayashi et al. (1990) have described missense variations in the conserved region of exon 10 of the cystic fibrosis (CF) transmembrane conductance regulator gene. In their paper, two [Delta]F508/F508C compound heterozygous individuals were reported. Clinical and epithelial physiological studies in both cases were normal, suggesting that the substitution of cysteine for phenylalanine at position 508, the F508C mutation, is benign. However, Kerem et al. reported a patient with this substitution who had typical symptoms of CF. In routine [Delta]F508 mutation screening by visualization of the 3-bp deletion on a 12% polyacrylamide gel the authors detected an abnormal heteroduplex in themore » father of a CF patient of German origin. Subsequent direct sequencing of the PCR product confirmed that this clinically normal father is a compound heterozygote for the [Delta]F508/F508C mutations. This heteroduplex is slightly different from the usual heteroduplex in [Delta]F508/F508C heteroduplex was not published, it is likely that similar cases can be overseen during the widely performed [Delta]F508 mutation screening by PAGE. Detection of more cases, such as the one presented here, together with careful, standardized clinical examination of the proband, would be valuable to verify the nature of this mutation. 4 refs., 1 fig.« less

Changing Incidence of Cystic Fibrosis in Wisconsin, USA

PubMed Central

Bersie, Rachel; Hoffman, Gary; Rock, Michael; Baker, Mei; Farrell, Philip M.; Simpson, Pippa; Levy, Hara

2015-01-01

Summary Rationale Previous investigations of cystic fibrosis (CF) incidence in Massachusetts, Colorado, and Minnesota (USA) yielded contradictory results, particularly regarding allele p.Phe508del; the racial compositions of the cohorts were not reported. Objectives To clarify discrepancies in reported incidence with the ultimate goal of improving screening and quality of care, we assessed CF incidence, stratified by race and mutations in cystic fibrosis transmembrane conductance regulator (CFTR), in Wisconsin (USA) from 1994 to 2011. Methods Data on patients diagnosed with CF (N=283), CFTR genotypes, CF carriers, and birth rate were collected. All data were categorized by racial background of the birth mother and the incidence of CF births was accordingly adjusted. Spearman’s nonparametric rank correlation and Fisher’s exact test were performed for continuous and categorical variables, respectively. Trends over time were fitted with a cubic spline. Results We detected a trending increase in CF cases (range within all data 1.67–2.98 per 10,000 births per year), homozygous p.Phe508del cases (0.57–1.79 per 10,000), heterozygous p.Phe508del cases (0.29–1.55 per 10,000), and cases lacking p. Phe508del (0–0.45 per 10,000). Both the number of cases lacking the p.Phe508del mutation per year and the number of cases lacking p.Phe508del per 10,000 births significantly increased (P=0.05) from 1994 to 2011; the increase in overall incidence was not significant. The number of carriers identified through newborn screening significantly increased within the non-Hispanic Black (P=0.0.021) and Hispanic (P=0.003) populations. Conclusion The racial composition of the CF cohort is changing in Wisconsin, possibly influencing disease detection, care, and outcome. PMID:26258862

Changing incidence of cystic fibrosis in Wisconsin, USA.

PubMed

Parker-McGill, Katelyn; Nugent, Melodee; Bersie, Rachel; Hoffman, Gary; Rock, Michael; Baker, Mei; Farrell, Philip M; Simpson, Pippa; Levy, Hara

2015-11-01

Previous investigations of cystic fibrosis (CF) incidence in Massachusetts, Colorado, and Minnesota (USA) yielded contradictory results, particularly regarding allele p.Phe508del; the racial compositions of the cohorts were not reported. To clarify discrepancies in reported incidence with the ultimate goal of improving screening and quality of care, we assessed CF incidence, stratified by race and mutations in cystic fibrosis transmembrane conductance regulator (CFTR), in Wisconsin (USA) from 1994 to 2011. Data on patients diagnosed with CF (N = 283), CFTR genotypes, CF carriers, and birth rate were collected. All data were categorized by racial background of the birth mother and the incidence of CF births was accordingly adjusted. Spearman's nonparametric rank correlation and Fisher's exact test were performed for continuous and categorical variables, respectively. Trends over time were fitted with a cubic spline. We detected a trending increase in CF cases (range within all data 1.67-2.98 per 10,000 births per year), homozygous p.Phe508del cases (0.57-1.79 per 10,000), heterozygous p.Phe508del cases (0.29-1.55 per 10,000), and cases lacking p.Phe508del (0-0.45 per 10,000). Both the number of cases lacking the p.Phe508del mutation per year and the number of cases lacking p.Phe508del per 10,000 births significantly increased (P = 0.05) from 1994 to 2011; the increase in overall incidence was not significant. The number of carriers identified through newborn screening significantly increased within the non-Hispanic Black (P = 0.0.021) and Hispanic (P = 0.003) populations. The racial composition of the CF cohort is changing in Wisconsin, possibly influencing disease detection, care, and outcome. © 2015 Wiley Periodicals, Inc.

Newborn screening for cystic fibrosis: Polish 4 years' experience with CFTR sequencing strategy.

PubMed

Sobczyńska-Tomaszewska, Agnieszka; Ołtarzewski, Mariusz; Czerska, Kamila; Wertheim-Tysarowska, Katarzyna; Sands, Dorota; Walkowiak, Jarosław; Bal, Jerzy; Mazurczak, Tadeusz

2013-04-01

Newborn screening for cystic fibrosis (NBS CF) in Poland was started in September 2006. Summary from 4 years' experience is presented in this study. The immunoreactive trypsin/DNA sequencing strategy was implemented. The group of 1,212,487 newborns were screened for cystic fibrosis during the programme. We identified a total of 221 CF cases during this period, including, 4 CF cases were reported to be omitted by NBS CF. Disease incidence in Poland based on the programme results was estimated as 1/4394 and carrier frequency as 1/33. The frequency of the F508del was similar (62%) to population data previously reported. This strategy allowed us to identify 29 affected infants with rare genotypes. The frequency of some mutations (eg, 2184insA, K710X) was assessed in Poland for the first time. Thus, sequencing assay seems to be accurate method for screening programme using blood spots in the Polish population.

A Genotypic-Oriented View of CFTR Genetics Highlights Specific Mutational Patterns Underlying Clinical Macrocategories of Cystic Fibrosis

PubMed Central

Lucarelli, Marco; Bruno, Sabina Maria; Pierandrei, Silvia; Ferraguti, Giampiero; Stamato, Antonella; Narzi, Fabiana; Amato, Annalisa; Cimino, Giuseppe; Bertasi, Serenella; Quattrucci, Serena; Strom, Roberto

2015-01-01

Cystic fibrosis (CF) is a monogenic disease caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The genotype–phenotype relationship in this disease is still unclear, and diagnostic, prognostic and therapeutic challenges persist. We enrolled 610 patients with different forms of CF and studied them from a clinical, biochemical, microbiological and genetic point of view. Overall, there were 125 different mutated alleles (11 with novel mutations and 10 with complex mutations) and 225 genotypes. A strong correlation between mutational patterns at the genotypic level and phenotypic macrocategories emerged. This specificity appears to largely depend on rare and individual mutations, as well as on the varying prevalence of common alleles in different clinical macrocategories. However, 19 genotypes appeared to underlie different clinical forms of the disease. The dissection of the pathway from the CFTR mutated genotype to the clinical phenotype allowed to identify at least two components of the variability usually found in the genotype–phenotype relationship. One component seems to depend on the genetic variation of CFTR, the other component on the cumulative effect of variations in other genes and cellular pathways independent from CFTR. The experimental dissection of the overall biological CFTR pathway appears to be a powerful approach for a better comprehension of the genotype–phenotype relationship. However, a change from an allele-oriented to a genotypic-oriented view of CFTR genetics is mandatory, as well as a better assessment of sources of variability within the CFTR pathway. PMID:25910067

A mouse model for the cystic fibrosis delta F508 mutation.

PubMed Central

van Doorninck, J H; French, P J; Verbeek, E; Peters, R H; Morreau, H; Bijman, J; Scholte, B J

1995-01-01

Most cystic fibrosis (CF) patients produce a mutant form (delta F508) of the cystic fibrosis transmembrane conductance regulator (CFTR), which is not properly processed in normal cells but is active as a chloride channel in several experimental systems. We used a double homologous recombination ('Hit and Run') procedure to generate a mouse model for the delta F508 mutation. Targeted embryonic stem (ES) cells (Hit clones) were found; of these either 80 or 20% of the clones had lost the delta F508 mutation, depending on the distance between the linearization site in the targeting construct and the delta F508 mutation. Correctly targeted clones underwent a second selection step resulting in ES cell clones (Run clones) heterozygous for the delta F508 mutation with an efficiency of 2-7%. Chimeric mice were generated and offspring homozygous for the delta F508 mutation showed electrophysiological abnormalities in nasal epithelium, gallbladder and in the intestine, and histological abnormalities in the intestine, typical of CF. Our data suggest that the delta F508 mice have residual delta F508 CFTR activity which would explain the mild pathology of the delta F508 mice. The delta F508 mouse may provide a useful model for the study of the processing defect of delta F508 CFTR and for the development of novel therapeutic approaches based on circumvention of the processing block. Images PMID:7556083

New treatments targeting the basic defects in cystic fibrosis.

PubMed

Fajac, Isabelle; Wainwright, Claire E

2017-06-01

Cystic fibrosis (CF) is a monogenic autosomal recessive disorder affecting around 75,000 individuals worldwide. It is a multi-system disease but the main morbidity and mortality is caused by chronic lung disease. Due to newborn screening, a multidisciplinary approach to care and intensive symptomatic treatment, the prognosis has dramatically improved over the last decades and there are currently more adults than children in many countries. However, CF is still a very severe disease with a current median age of life expectancy in the fourth decade of life. The disease is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene which encodes the CFTR protein, a protein kinase A-activated ATP-gated anion channel that regulates the transport of electrolytes such as chloride and bicarbonate. More than 2000 mutations have been reported, although not all of these have functional consequences. An enormous research effort and progress has been made in understanding the consequences of these mutations on the CFTR protein structure and function, and this has led to the approval of two new drug therapies that are able to bind to defective CFTR proteins and partially restore their function. They are mutation-specific therapies and available at present for specific mutations only. They are the first personalized medicine for CF with a possible disease-modifying effect. A pipeline of other compounds is under development with different mechanisms of action. It is foreseeable that new combinations of compounds will further improve the correction of CFTR function. Other strategies including premature stop codon read-through drugs, antisense oligonucleotides that correct the basic defect at the mRNA level or gene editing to restore the defective gene as well as gene therapy approaches are all in the pipeline. All these strategies are needed to develop disease-modifying therapies for all patients with CF. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Neonatal Gastrointestinal and Respiratory Microbiome in Cystic Fibrosis: Potential Interactions and Implications for Systemic Health.

PubMed

Madan, Juliette C

2016-04-01

The gastrointestinal microbiome plays a critical role in nutrition and metabolic and immune functions in infants and young children and has implications for lifelong health. Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) mutations in CF result in viscous mucous production, frequent exposure to antibiotics, and atypical colonization patterns, resulting in an evolving dysbiosis of the gastrointestinal and respiratory microsystems; dysbiosis in CF results in systemic inflammation, chronic infection, and dysregulation of immune function. Dysbiosis in both the respiratory system and gut contributes to undernutrition, growth failure, and long-term respiratory and systemic morbidity in infants and children with CF. Understanding the role that the gut and respiratory microbiome plays in health or disease progression in CF will afford opportunities to better identify interventions to affect clinical changes. Summary was done of the pertinent literature in CF and the study of the microbiome and probiotics. New studies have identified bacteria in the respiratory tract in CF that are typically members of the intestinal microbiota, and enteral exposures to breast milk and probiotics are associated with prolonged periods of respiratory stability in CF. Understanding the complex interactions between the CFTR mutations, microbial colonization, and mucosal and systemic immunity is of major importance to inform new treatment strategies (such as restoring a healthier microbiome with probiotics or dietary interventions) to improve nutritional status and immune competence and to decrease morbidity and mortality in CF. Copyright © 2016. Published by Elsevier Inc.

Hypermutation in Burkholderia cepacia complex is mediated by DNA mismatch repair inactivation and is highly prevalent in cystic fibrosis chronic respiratory infection.

PubMed

Martina, Pablo; Feliziani, Sofía; Juan, Carlos; Bettiol, Marisa; Gatti, Blanca; Yantorno, Osvaldo; Smania, Andrea M; Oliver, Antonio; Bosch, Alejandra

2014-11-01

The Burkholderia cepacia complex (Bcc) represents an important group of pathogens involved in long-term lung infection in cystic fibrosis (CF) patients. A positive selection of hypermutators, linked to antimicrobial resistance development, has been previously reported for Pseudomonas aeruginosa in this chronic infection setting. Hypermutability, however, has not yet been systematically evaluated in Bcc species. A total of 125 well characterized Bcc isolates recovered from 48 CF patients, 10 non-CF patients and 15 environmental samples were analyzed. In order to determine the prevalence of mutators their spontaneous mutation rates to rifampicin resistance were determined. In addition, the genetic basis of the mutator phenotypes was investigated by sequencing the mutS and mutL genes, the main components of the mismatch repair system (MRS). The overall prevalence of hypermutators in the collection analyzed was 13.6%, with highest occurrence (40.7%) among the chronically infected CF patients, belonging mainly to B. cenocepacia, B. multivorans, B. cepacia, and B. contaminans -the most frequently recovered Bcc species from CF patients worldwide. Thirteen (76.5%) of the hypermutators were defective in mutS and/or mutL. Finally, searching for a possible association between antimicrobial resistance and hypermutability, the resistance-profiles to 17 antimicrobial agents was evaluated. High antimicrobial resistance rates were documented for all the Bcc species recovered from CF patients, but, except for ciprofloxacin, a significant association with hypermutation was not detected. In conclusion, in the present study we demonstrate for the first time that, MRS-deficient Bcc species mutators are highly prevalent and positively selected in CF chronic lung infections. Hypermutation therefore, might be playing a key role in increasing bacterial adaptability to the CF-airway environment, facilitating the persistence of chronic lung infections. Copyright © 2014 Elsevier GmbH. All rights reserved.

[Management of infants whose diagnosis is inconclusive at neonatal screening for cystic fibrosis].

PubMed

Sermet-Gaudelus, I; Brouard, J; Audrézet, M-P; Couderc Kohen, L; Weiss, L; Wizla, N; Vrielynck, S; LLerena, K; Le Bourgeois, M; Deneuville, E; Remus, N; Nguyen-Khoa, T; Raynal, C; Roussey, M; Girodon, E

2017-04-01

Neonatal screening for cystic fibrosis (CF) may detect infants with elevated immunoreactive trypsinogen (IRT) levels but with inconclusive sweat tests and/or DNA results. This includes cases associating (1) either the presence of at most one CF-causing mutation and sweat chloride values between 30 and 59mmol/L or (2) two CFTR mutations with at least one of unknown pathogenicity and a sweat chloride below 60mmol/L. This encompasses different clinical situations whose progression cannot be predicted. These cases require redoing the sweat test at 12 months and if possible at 6 and 24 months of life. This must be associated with extended genotyping. CFTR functional explorations can also help by investigating CFTR dysfunction. These infants must be initially evaluated in dedicated CF centers including bacteriological sputum analysis, chest radiology and fecal elastase dosage. A home practitioner must be informed of the specificity of follow-up. These infants will be reviewed in the CF center at 3, 6 and 12 months and every year. Any CF-related symptom requires reevaluation of the diagnosis. These guidelines were established by the "neonatal screening and difficult diagnoses" working group of the French CF Society. They aim to standardize management of infants with unclear diagnosis in French CF centers. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Cystic Fibrosis: A Review of Associated Phenotypes, Use of Molecular Diagnostic Approaches, Genetic Characteristics, Progress, and Dilemmas.

PubMed

Brennan, Marie-Luise; Schrijver, Iris

2016-01-01

Cystic fibrosis (CF) is an autosomal recessive disease with significant associated morbidity and mortality. It is now appreciated that the broad phenotypic CF spectrum is not explained by obvious genotype-phenotype correlations, suggesting that CF transmembrane conductance regulator (CFTR)-related disease may occur because of multiple additive effects. These contributing effects include complex CFTR alleles, modifier genes, mutations in alternative genes that produce CF-like phenotypes, epigenetic factors, and environmental influences. Most patients in the United States are now diagnosed through newborn screening and use of molecular testing methods. We review the molecular testing approaches and laboratory guidelines for carrier screening, prenatal testing, newborn screening, and clinical diagnostic testing, as well as recent developments in CF treatment, and reasons for the lack of a molecular diagnosis in some patients. Copyright © 2016 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Factors Accounting for a Missed Diagnosis of Cystic Fibrosis After Newborn Screening

PubMed Central

Rock, Michael J.; Levy, Hara; Zaleski, Christina; Farrell, Philip M.

2015-01-01

Summary Newborn screening is a public health policy program involving the centralized testing laboratory, infant and their family, primary care provider, and subspecialist for confirmatory testing and follow-up of abnormal results. Cystic fibrosis (CF) newborn screening has now been enacted in all 50 states and the District of Columbia and throughout many countries in the world. Although CF neonatal screening will identify the vast majority of infants with CF, there are many factors in the newborn screening system that can lead to a missed diagnosis of CF. To inform clinicians, this article summarizes the CF newborn screening system and highlights 14 factors that can account for a missed diagnosis of CF. Care providers should maintain a high suspicion for CF if there are compatible symptoms, regardless of the results of the newborn screening test. These factors in newborn screening programs leading to a missed diagnosis of CF present opportunities for quality improvement in specimen collection, laboratory analysis of immunoreactive tryspinogen (IRT) and CF mutation testing, communication, and sweat testing. PMID:22081556

The diagnosis of cystic fibrosis.

PubMed

De Boeck, Kris; Vermeulen, Francois; Dupont, Lieven

2017-06-01

Establishing the diagnosis of cystic fibrosis (CF) is straight forward in the majority of patients: they present with a clear clinical picture (most frequently chronic respiratory symptoms plus malabsorption), the sweat chloride value is>60mmol/L and two known disease causing CFTR mutations are identified. In less than 5% of subjects, mainly those with a milder or limited phenotype, the diagnostic process is more complex, because initial diagnostic test results are inconclusive: sweat chloride concentration in the intermediate range, less than 2 CF causing mutations identified or both. These patients should be referred to expert centers where bioassays of CFTR function like nasal potential difference measurement or intestinal current measurement can be done. Still, in some patients, despite symptoms compatible with CF and some indication of CFTR dysfunction (e.g. only intermediate sweat chloride value), diagnostic criteria are not met (e.g. only 1 CFTR mutation identified). For these subjects, the term CFTR related disorder (CFTR-RD) is used. Patients with disseminated bronchiectasis, congenital bilateral absence of the vas deferens and acute or recurrent pancreatitis may fall in this category. CF has a very wide disease spectrum and increasingly the diagnosis is being made during adult life, mainly in subjects with milder phenotypes. In many countries, nationwide CF newborn screening (NBS) has been introduced. In screen positive babies, the diagnosis of CF must be confirmed by a sweat test demonstrating a sweat chloride concentration above 60mmol/L. To achieve the benefit of NBS, every baby in whom the diagnosis of CF is confirmed must receive immediate follow-up and treatment in a CF reference center. CF NBS is not full proof: some diagnoses will be missed and in some babies the diagnosis cannot be confirmed nor ruled out with certainty. Screening algorithms that include gene sequencing will detect a high number of such babies that are screen positive with an inconclusive diagnosis (CFSPID). Even in 2016, the most reliable and widely available diagnostic test for CF is the measurement of chloride concentration in sweat. The method of choice is sweat induction by pilocarpine iontophoresis, followed by sweat collection on a gauze or filter paper or in a Macroduct coil. Since mutation specific therapies have become available, it is important to identify the mutations responsible for CF in each individual patient. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Cystic fibrosis transmembrane conductance regulator protein (CFTR) expression in the developing human brain: comparative immunohistochemical study between patients with normal and mutated CFTR.

PubMed

Marcorelles, Pascale; Friocourt, Gaëlle; Uguen, Arnaud; Ledé, Françoise; Férec, Claude; Laquerrière, Annie

2014-11-01

Cystic Fibrosis Transmembrane conductance Regulator (CFTR) protein has recently been shown to be expressed in the human adult central nervous system (CNS). As CFTR expression has also been documented during embryonic development in several organs, such as the respiratory tract, the intestine and the male reproductive system, suggesting a possible role during development we decided to investigate the expression of CFTR in the human developing CNS. In addition, as some, although rare, neurological symptoms have been reported in patients with CF, we compared the expression of normal and mutated CFTR at several fetal stages. Immunohistochemistry was performed on brain and spinal cord samples of foetuses between 13 and 40 weeks of gestation and compared with five patients with cystic fibrosis (CF) of similar ages. We showed in this study that CFTR is only expressed in neurons and has an early and widespread distribution during development. Although we did not observe any cerebral abnormality in patients with CF, we observed a slight delay in the maturation of several brain structures. We also observed different expression and localization of CFTR depending on the brain structure or the cell maturation stage. Our findings, along with a literature review on the neurological phenotypes of patients with CF, suggest that this gene may play previously unsuspected roles in neuronal maturation or function. © The Author(s) 2014.

Cystic fibrosis–adapted Pseudomonas aeruginosa quorum sensing lasR mutants cause hyperinflammatory responses

PubMed Central

LaFayette, Shantelle L.; Houle, Daniel; Beaudoin, Trevor; Wojewodka, Gabriella; Radzioch, Danuta; Hoffman, Lucas R.; Burns, Jane L.; Dandekar, Ajai A.; Smalley, Nicole E.; Chandler, Josephine R.; Zlosnik, James E.; Speert, David P.; Bernier, Joanie; Matouk, Elias; Brochiero, Emmanuelle; Rousseau, Simon; Nguyen, Dao

2015-01-01

Cystic fibrosis lung disease is characterized by chronic airway infections with the opportunistic pathogen Pseudomonas aeruginosa and severe neutrophilic pulmonary inflammation. P. aeruginosa undergoes extensive genetic adaptation to the cystic fibrosis (CF) lung environment, and adaptive mutations in the quorum sensing regulator gene lasR commonly arise. We sought to define how mutations in lasR alter host-pathogen relationships. We demonstrate that lasR mutants induce exaggerated host inflammatory responses in respiratory epithelial cells, with increased accumulation of proinflammatory cytokines and neutrophil recruitment due to the loss of bacterial protease–dependent cytokine degradation. In subacute pulmonary infections, lasR mutant–infected mice show greater neutrophilic inflammation and immunopathology compared with wild-type infections. Finally, we observed that CF patients infected with lasR mutants have increased plasma interleukin-8 (IL-8), a marker of inflammation. These findings suggest that bacterial adaptive changes may worsen pulmonary inflammation and directly contribute to the pathogenesis and progression of chronic lung disease in CF patients. PMID:26457326

Genotype-phenotype correlation and functional studies in patients with cystic fibrosis bearing CFTR complex alleles.

PubMed

Terlizzi, Vito; Castaldo, Giuseppe; Salvatore, Donatello; Lucarelli, Marco; Raia, Valeria; Angioni, Adriano; Carnovale, Vincenzo; Cirilli, Natalia; Casciaro, Rosaria; Colombo, Carla; Di Lullo, Antonella Miriam; Elce, Ausilia; Iacotucci, Paola; Comegna, Marika; Scorza, Manuela; Lucidi, Vincenzina; Perfetti, Anna; Cimino, Roberta; Quattrucci, Serena; Seia, Manuela; Sofia, Valentina Maria; Zarrilli, Federica; Amato, Felice

2017-04-01

The effect of complex alleles in cystic fibrosis (CF) is poorly defined for the lack of functional studies. To describe the genotype-phenotype correlation and the results of either in vitro and ex vivo studies performed on nasal epithelial cells (NEC) in a cohort of patients with CF carrying cystic fibrosis transmembrane conductance regulator ( CFTR ) complex alleles. We studied 70 homozygous, compound heterozygous or heterozygous for CFTR mutations: p.[Arg74Trp;Val201Met;Asp1270Asn], n=8; p.[Ile148Thr;Ile1023_Val1024del], n=5; p.[Arg117Leu;Leu997Phe], n=6; c.[1210-34TG[12];1210-12T[5];2930C>T], n=3; p.[Arg74Trp;Asp1270Asn], n=4; p.Asp1270Asn, n=2; p.Ile148Thr, n=6; p.Leu997Phe, n=36. In 39 patients, we analysed the CFTR gating activity on NEC in comparison with patients with CF (n=8) and carriers (n=4). Finally, we analysed in vitro the p.[Arg74Trp;Val201Met;Asp1270Asn] complex allele. The p.[Ile148Thr;Ile1023_Val1024del] caused severe CF in five compound heterozygous with a class I-II mutation. Their CFTR activity on NEC was comparable with patients with two class I-II mutations (mean 7.3% vs 6.9%). The p.[Arg74Trp;Asp1270Asn] and the p.Asp1270Asn have scarce functional effects, while p.[Arg74Trp;Val201Met;Asp1270Asn] caused mild CF in four of five subjects carrying a class I-II mutation in trans , or CFTR-related disorders (CFTR-RD) in three having in trans a class IV-V mutation. The p.[Arg74Trp;Val201Met;Asp1270Asn] causes significantly (p<0.001) higher CFTR activity compared with compound heterozygous for class I-II mutations. Furthermore, five of six compounds heterozygous with the p.[Arg117Leu;Leu997Phe] had mild CF, whereas the p.Leu997Phe, in trans with a class I-II CFTR mutation, caused CFTR-RD or a healthy status (CFTR activity: 21.3-36.9%). Finally, compounds heterozygous for the c.[1210-34TG[12];1210-12T[5];2930C>T] and a class I-II mutation had mild CF or CFTR-RD (gating activity: 18.5-19.0%). The effect of complex alleles partially depends on the mutation in trans . Although larger studies are necessary, the CFTR activity on NEC is a rapid contributory tool to classify patients with CFTR dysfunction. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Future directions in early cystic fibrosis lung disease research: an NHLBI workshop report.

PubMed

Ramsey, Bonnie W; Banks-Schlegel, Susan; Accurso, Frank J; Boucher, Richard C; Cutting, Garry R; Engelhardt, John F; Guggino, William B; Karp, Christopher L; Knowles, Michael R; Kolls, Jay K; LiPuma, John J; Lynch, Susan; McCray, Paul B; Rubenstein, Ronald C; Singh, Pradeep K; Sorscher, Eric; Welsh, Michael

2012-04-15

Since the 1989 discovery that mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF), there has been substantial progress toward understanding the molecular basis for CF lung disease, leading to the discovery and development of new therapeutic approaches. However, the earliest impact of the loss of CFTR function on airway physiology and structure and its relationship to initial infection and inflammation are poorly understood. Universal newborn screening for CF in the United States represents an unprecedented opportunity for investigating CF clinical manifestations very early in life. Recently developed animal models with pulmonary phenotypic manifestations also provide a window into the early consequences of this genetic disorder. For these reasons, the National Heart, Lung, and Blood Institute (NHLBI) convened a working group of extramural experts, entitled "Future Research Directions in Early CF Lung Disease" on September 21-22, 2010, to identify future research directions of great promise in CF. The priority areas identified included (1) exploring pathogenic mechanisms of early CF lung disease; (2) leveraging newborn screening to elucidate the natural history of early lung disease; (3) developing a spectrum of biomarkers of early lung disease that reflects CF pathophysiology, clinical outcome, and response to treatment; (4) exploring the role of genetics/genomics (e.g., modifier genes, gene-environmental interactions, and epigenetics) in early CF pathogenesis; (5) defining early microbiological events in CF lung disease; and (6) elucidating the initial airway inflammatory, remodeling, and repair mechanisms in CF lung disease.

Blood Culture Test

MedlinePlus

... Mutation Testing Breast Cancer Gene Expression Tests C-peptide C-Reactive Protein (CRP) CA 15-3 CA- ... Kinase (CK) Creatinine Creatinine Clearance Cryoglobulins Cyclic Citrullinated Peptide Antibody Cyclosporine Cystatin C Cystic Fibrosis (CF) Gene ...

Synovial Fluid Analysis

MedlinePlus

... Mutation Testing Breast Cancer Gene Expression Tests C-peptide C-Reactive Protein (CRP) CA 15-3 CA- ... Kinase (CK) Creatinine Creatinine Clearance Cryoglobulins Cyclic Citrullinated Peptide Antibody Cyclosporine Cystatin C Cystic Fibrosis (CF) Gene ...

Pericardial Fluid Analysis

MedlinePlus

... Mutation Testing Breast Cancer Gene Expression Tests C-peptide C-Reactive Protein (CRP) CA 15-3 CA- ... Kinase (CK) Creatinine Creatinine Clearance Cryoglobulins Cyclic Citrullinated Peptide Antibody Cyclosporine Cystatin C Cystic Fibrosis (CF) Gene ...

Normal sweat chloride test does not rule out cystic fibrosis.

PubMed

Başaran, Abdurrahman Erdem; Karataş-Torun, Nimet; Maslak, İbrahim Cemal; Bingöl, Ayşen; Alper, Özgül M

2017-01-01

Başaran AE, Karataş-Torun N, Maslak İC, Bingöl A, Alper ÖM. Normal sweat chloride test does not rule out cystic fibrosis. Turk J Pediatr 2017; 59: 68-70. A 5-month-old patient presented with complaints of fever and cough. He was hospitalized with the diagnosis of bronchopneumonia and pseudo-Bartter's syndrome. Patient was further investigated for diagnosis of cystic fibrosis. The chloride (Cl) level in sweat was determined within the normal range (25.1 mmol/L, 20.3 mmol/L). CFTR (Cystic Fibrosis Transmembrane Regulator gene; NM_000492.2) genotyping results were positive for p.E92K; p.F1052V mutations. The patient was diagnosed with cystic fibrosis. In our patient, with features of CF and normal sweat test, mutation analysis was helpful for the diagnosis of cystic fibrosis.

HIV Genotypic Resistance Testing

MedlinePlus

... Mutation Testing Breast Cancer Gene Expression Tests C-peptide C-Reactive Protein (CRP) CA 15-3 CA- ... Kinase (CK) Creatinine Creatinine Clearance Cryoglobulins Cyclic Citrullinated Peptide Antibody Cyclosporine Cystatin C Cystic Fibrosis (CF) Gene ...

Statement of The American Society of Human Genetics on cystic fibrosis carrier screening

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The identification in 1989 of the cystic fibrosis (CF) gene and its most common mutation immediately raised the possibility of CF carrier detection by DNA analysis. The American Society of Human Genetics (ASHG) issued a statement recommending that CF carrier testing should be made available to individuals with a family history of CF. It was also stated that screening of individuals or couples in the general population should not be offered until the rate of CF carrier detection improves. An additional prerequisite emphasized the need for the establishment of effective educational and counseling programs consistent with previous widely accepted principles.more » An NIH workshop reached similar conclusions. ASHG recommendations are that screening be limited to individuals with a family history of CF, testing should be accompanied by education and counseling, screening should be voluntary and confidential with appropriate laboratory quality controls, and efforts should be expanded to educate health care providers and the public.« less

Serum zinc concentration in cystic fibrosis patients with CFTR I1234V mutation associated with pancreatic sufficiency.

PubMed

AbdulWahab, Atqah; Abushahin, Ahmed; Allangawi, Mona; Chandra, Prem; Abdel Rahman, Mohamed Osman; Soliman, Ashraf

2017-05-01

To determine serum zinc (Zn) level among cystic fibrosis (CF) patients with homozygous CFTR I1234V mutation associated with pancreatic sufficiency (PS). A cross-sectional study was conducted including both pediatric and adult CF patients. Data on age, weight, height, body mass index (BMI), BMI Z-score, FEV1, and chronic Pseudomonas aeruginosa infection were collected. Serum Zn, albumin, and total proteins were measured and analyzed. Forty-five CF patients with homozygous CFTR I1234V mutation belonging to a large Arab kindred tribe and eight CF patients with other mutations associated with pancreatic insufficiency (PI). Patient's age ranged from 2 to 49 years with a mean age of 15.1 ± 9.1 years and mean plasma Zn of 0.78 ± 0.15 mcg/mL. Seven (13.2%) patients with CFTR I1234V and PS had low Zn levels (<0.6 mcg/mL). Mean age among Zn deficient group was significantly older. The mean FEV1 in the deficient group was found to be insignificant low. Persistent P. aeruginosa colonization was more prevalent in Zn deficient group. BMI Z-scosre of CF patients were positively correlated with Zn levels. Forty-five healthy subjects belonging to the same Arab tribe were selected in order to assess their Zn levels and their mean plasma Zn of 0.84 ± 0.11 mcg/mL (range 0.65-1.1 mcg/mL) with mean age 20.4 ± 10.1 years (range 6-40 years). These findings suggest that Zn deficiency can occur in CF patients with PS. The association of Zn levels and the frequency of P. aeruginosa isolated in CF patients need further investigation. © 2015 The Authors. The Clinical Respiratory Journal Published by John Wiley & Sons Ltd.

A European regulatory perspective on cystic fibrosis: current treatments, trends in drug development and translational challenges for CFTR modulators.

PubMed

Ponzano, Stefano; Nigrelli, Giulia; Fregonese, Laura; Eichler, Irmgard; Bertozzi, Fabio; Bandiera, Tiziano; Galietta, Luis J V; Papaluca, Marisa

2018-06-30

In this article we analyse the current authorised treatments and trends in early drug development for cystic fibrosis (CF) in the European Union for the time period 2000-2016. The analysis indicates a significant improvement in the innovation and development of new potential medicines for CF, shifting from products that act on the symptoms of the disease towards new therapies targeting the cause of CF. However, within these new innovative medicines, results for CF transmembrane conductance regulator (CFTR) modulators indicate that one major challenge for turning a CF concept product into an actual medicine for the benefit of patients resides in the fact that, although pre-clinical models have shown good predictability for certain mutations, a good correlation to clinical end-points or biomarkers ( e.g. forced expiratory volume in 1 s and sweat chloride) for all mutations has not yet been achieved. In this respect, the use of alternative end-points and innovative nonclinical models could be helpful for the understanding of those translational discrepancies. Collaborative endeavours to promote further research and development in these areas as well as early dialogue with the regulatory bodies available at the European competent authorities are recommended. Copyright ©ERS 2018.

Loss of Cystic Fibrosis Transmembrane Conductance Regulator Function Enhances Activation of p38 and ERK MAPKs, Increasing Interleukin-6 Synthesis in Airway Epithelial Cells Exposed to Pseudomonas aeruginosa*

PubMed Central

Bérubé, Julie; Roussel, Lucie; Nattagh, Leila; Rousseau, Simon

2010-01-01

In cystic fibrosis (CF), the absence of functional cystic fibrosis transmembrane conductance regulator (CFTR) translates into chronic bacterial infection, excessive inflammation, tissue damage, impaired lung function and eventual death. Understanding the mechanisms underlying this vicious circle of inflammation is important to design better therapies for CF. We found in CF lung biopsies increased immunoreactivity for p38 MAPK activity markers. Moreover, when compared with their non-CF counterpart, airway epithelial cells expressing the most common mutation in CF (CFTRΔF508) were more potent at inducing neutrophil chemotaxis through increased interleukin (IL)-6 synthesis when challenged with Pseudomonas aeruginosa diffusible material. We then discovered that in CFTRΔF508 cells, the p38 and ERK MAPKs are hyperactivated in response to P. aeruginosa diffusible material, leading to increased IL-6 mRNA expression and stability. Moreover, although TLR5 contributes to p38 MAPK activation upon P. aeruginosa challenge, it only played a weak role in IL-6 synthesis. Instead, we found that the production of reactive oxygen species is essential for IL-6 synthesis in response to P. aeruginosa diffusible material. Finally, we uncovered that in CFTRΔF508 cells, the extracellular glutathione levels are decreased, leading to a greater sensitivity to reactive oxygen species, providing an explanation for the hyperactivation of the p38 and ERK MAPKs and increased IL-6 synthesis. Taken together, our study has characterized a mechanism whereby the CFTRΔF508 mutation in airway epithelial cells contributes to increase inflammation of the airways. PMID:20460375

In vivo and in vitro ivacaftor response in cystic fibrosis patients with residual CFTR function: N-of-1 studies.

PubMed

McGarry, Meghan E; Illek, Beate; Ly, Ngoc P; Zlock, Lorna; Olshansky, Sabrina; Moreno, Courtney; Finkbeiner, Walter E; Nielson, Dennis W

2017-04-01

Ivacaftor, a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator, decreases sweat chloride concentration, and improves pulmonary function in 6% of cystic fibrosis (CF) patients with specific CFTR mutations. Ivacaftor increases chloride transport in many other CFTR mutations in non-human cells, if CFTR is in the epithelium. Some CF patients have CFTR in the epithelium with residual CFTR function. The effect of ivacaftor in these patients is unknown. This was a series of randomized, crossover N-of-1 trials of ivacaftor and placebo in CF patients ≥8 years old with potential residual CFTR function (intermediate sweat chloride concentration, pancreatic sufficient, or mild bronchiectasis on chest CT). Human nasal epithelium (HNE) was obtained via nasal brushing and cultured. Sweat chloride concentration change was the in vivo outcome. Chloride current change in HNE cultures with ivacaftor was the in vitro outcome. Three subjects had decreased sweat chloride concentration (-14.8 to -40.8 mmol/L, P < 0.01). Two subjects had unchanged sweat chloride concentration. Two subjects had increased sweat chloride concentration (+23.8 and +27.3 mmol/L, P < 0.001); both were heterozygous for A455E and pancreatic sufficient. Only subjects with decreased sweat chloride concentration had increased chloride current in HNE cultures. Some CF patients with residual CFTR function have decreased sweat chloride concentration with ivacaftor. Increased chloride current in HNE cultures among subjects with decreased sweat chloride concentrations may predict clinical response to ivacaftor. Ivacaftor can increase sweat chloride concentration in certain mutations with unclear clinical effect. Pediatr Pulmonol. 2017;52:472-479. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Binding screen for cystic fibrosis transmembrane conductance regulator correctors finds new chemical matter and yields insights into cystic fibrosis therapeutic strategy.

PubMed

Hall, Justin D; Wang, Hong; Byrnes, Laura J; Shanker, Suman; Wang, Kelong; Efremov, Ivan V; Chong, P Andrew; Forman-Kay, Julie D; Aulabaugh, Ann E

2016-02-01

The most common mutation in cystic fibrosis (CF) patients is deletion of F508 (ΔF508) in the first nucleotide binding domain (NBD1) of the CF transmembrane conductance regulator (CFTR). ΔF508 causes a decrease in the trafficking of CFTR to the cell surface and reduces the thermal stability of isolated NBD1; it is well established that both of these effects can be rescued by additional revertant mutations in NBD1. The current paradigm in CF small molecule drug discovery is that, like revertant mutations, a path may exist to ΔF508 CFTR correction through a small molecule chaperone binding to NBD1. We, therefore, set out to find small molecule binders of NBD1 and test whether it is possible to develop these molecules into potent binders that increase CFTR trafficking in CF-patient-derived human bronchial epithelial cells. Several fragments were identified that bind NBD1 at either the CFFT-001 site or the BIA site. However, repeated attempts to improve the affinity of these fragments resulted in only modest gains. Although these results cannot prove that there is no possibility of finding a high-affinity small molecule binder of NBD1, they are discouraging and lead us to hypothesize that the nature of these two binding sites, and isolated NBD1 itself, may not contain the features needed to build high-affinity interactions. Future work in this area may, therefore, require constructs including other domains of CFTR in addition to NBD1, if high-affinity small molecule binding is to be achieved. © 2016 The Protein Society.

Cystic fibrosis: a clinical view.

PubMed

Castellani, Carlo; Assael, Baroukh M

2017-01-01

Cystic fibrosis (CF), a monogenic disease caused by mutations in the CFTR gene on chromosome 7, is complex and greatly variable in clinical expression. Airways, pancreas, male genital system, intestine, liver, bone, and kidney are involved. The lack of CFTR or its impaired function causes fat malabsorption and chronic pulmonary infections leading to bronchiectasis and progressive lung damage. Previously considered lethal in infancy and childhood, CF has now attained median survivals of 50 years of age, mainly thanks to the early diagnosis through neonatal screening, recognition of mild forms, and an aggressive therapeutic attitude. Classical treatment includes pancreatic enzyme replacement, respiratory physiotherapy, mucolitics, and aggressive antibiotic therapy. A significant proportion of patients with severe symptoms still requires lung or, less frequently, liver transplantation. The great number of mutations and their diverse effects on the CFTR protein account only partially for CF clinical variability, and modifier genes have a role in modulating the clinical expression of the disease. Despite the increasing understanding of CFTR functioning, several aspects of CF need still to be clarified, e.g., the worse outcome in females, the risk of malignancies, the pathophysiology, and best treatment of comorbidities, such as CF-related diabetes or CF-related bone disorder. Research is focusing on new drugs restoring CFTR function, some already available and with good clinical impact, others showing promising preliminary results that need to be confirmed in phase III clinical trials.

Patterns of haplotypes for 92 cystic fibrosis mutations: Variability, association and recurrence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morral, N.; Llevadot, R.; Estivill, X.

1994-09-01

Most CFTR mutations are very uncommon among the cystic fibrosis population, with frequencies of less than 1%, and many are found only in specific areas. We have analyzed 92 CF mutations for several markers (4 microsatellites and 3 other polymorphisms) scattered in the CFTR gene. Haplotypes associated with these mutations can be used as a framework in the screening of chromosomes carrying unknown mutations. The association between mutation and haplotype reduces the number of mutations it is necessary to search for to a maximum of 16 for the same haplotype. Only mutations {triangle}F508, G542X and N1303K are associated with moremore » than one haplotype as a result of slippage at more than one microsatellite loci, suggesting that these three are the most ancient CF mutations. Recurrence has been found for at least 7 mutations: H199Y, R347P, L558S, R553X, 2184insA, 3272-26A{r_arrow}G, 3849+10kbC{r_arrow}T and R1162X. Also microsatellite analysis of chromosomes of several ethnic origins (Czech, Italian, Russian, Slovac and Spanish) suggested that possibility of three or more independent origins for mutations R334W, R347P, R1162X, and 3849+10kbC{r_arrow}T, which was confirmed by analysis of markers flanking these mutations.« less

Clinical expression of patients with the D1152H CFTR mutation.

PubMed

Terlizzi, Vito; Carnovale, Vincenzo; Castaldo, Giuseppe; Castellani, Carlo; Cirilli, Natalia; Colombo, Carla; Corti, Fabiola; Cresta, Federico; D'Adda, Alice; Lucarelli, Marco; Lucidi, Vincenzina; Macchiaroli, Annamaria; Madarena, Elisa; Padoan, Rita; Quattrucci, Serena; Salvatore, Donatello; Zarrilli, Federica; Raia, Valeria

2015-07-01

Discordant results were reported on the clinical expression of subjects bearing the D1152H CFTR mutation, and also for the small number of cases reported so far. A retrospective review of clinical, genetic and biochemical data was performed from individuals homozygous or compound heterozygous for the D1152H mutation followed in 12 Italian cystic fibrosis (CF) centers. 89 subjects carrying at least D1152H on one allele were identified. 7 homozygous patients had very mild clinical expression. Over half of the 74 subjects compound heterozygous for D1152H and a I-II-III class mutation had borderline or pathological sweat test and respiratory or gastrointestinal symptoms; one third had pulmonary bacteria colonization and 10/74 cases had complications (i.e. diabetes, allergic bronchopulmonary aspergillosis, and hemoptysis). However, their clinical expression was less severe as compared to a group of CF patients homozygous for the F508del mutation. Finally, 8 subjects compound heterozygous for D1152H and a IV-V class mutation showed very mild disease. The natural history of subjects bearing the D1152H mutation is widely heterogeneous and is influenced by the mutation in trans. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

The c.1364C>A (p.A455E) Mutation in the CFTR Pseudogene Results in an Incorrectly Assigned Carrier Status by a Commonly Used Screening Platform.

PubMed

Deeb, Kristin K; Metcalf, James D; Sesock, Kaitlin M; Shen, Junqing; Wensel, Christine A; Rippel, Larisa I; Smith, Michelle; Chapman, Mark S; Zhang, Shulin

2015-07-01

Cystic fibrosis (CF) is one of the most common recessive conditions among whites, with an estimated carrier frequency of 1 in 25 in the United States. Population-based CF carrier screening was implemented in the United States in 2001. The number of mutations screened by each laboratory may vary; however, the 23 most common CF mutations recommended for screening by the American College of Medical Genetics and American College of Obstetricians and Gynecologists are included in all platforms. The c.1364C>A (p.A455E) mutation located in exon 10 of the CFTR gene is one of the 23 mutations. Because CFTR exon 10 and its flanking intronic regions are duplicated and transposed onto several other chromosomes of the human genome during evolution and function as unprocessed pseudogenes, variations in the CFTR pseudogenes may confound CF screening results for mutations located in exon 10 of the CFTR gene. We report an incorrectly identified carrier status for the c.1364C>A (p.A455E) mutation in a healthy individual using the Hologic InPlex CF assay. Further analysis revealed that the mutation resides in one of the CFTR pseudogenes. Because most commercial kits and laboratory-developed tests for CF carrier screening involve a short amplicon encompassing this mutation, this finding suggests that individuals with the c.1364C>A (p.A455E) mutation may require further investigation to avoid a false assignment of CF carrier status. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Vx-809/Vx-770 treatment reduces inflammatory response to Pseudomonas aeruginosa in primary differentiated cystic fibrosis bronchial epithelial cells.

PubMed

Ruffin, Manon; Roussel, Lucie; Maillé, Émilie; Rousseau, Simon; Brochiero, Emmanuelle

2018-04-01

Cystic fibrosis patients exhibit chronic Pseudomonas aeruginosa respiratory infections and sustained proinflammatory state favoring lung tissue damage and remodeling, ultimately leading to respiratory failure. Loss of cystic fibrosis transmembrane conductance regulator (CFTR) function is associated with MAPK hyperactivation and increased cytokines expression, such as interleukin-8 [chemoattractant chemokine (C-X-C motif) ligand 8 (CXCL8)]. Recently, new therapeutic strategies directly targeting the basic CFTR defect have been developed, and ORKAMBI (Vx-809/Vx-770 combination) is the only Food and Drug Administration-approved treatment for CF patients homozygous for the F508del mutation. Here we aimed to determine the effect of the Vx-809/Vx-770 combination on the induction of the inflammatory response by fully differentiated primary bronchial epithelial cell cultures from CF patients carrying F508del mutations, following exposure to P. aeruginosa exoproducts. Our data unveiled that CFTR functional rescue with Vx-809/Vx-770 drastically reduces CXCL8 (as well as CXCL1 and CXCL2) transcripts and p38 MAPK phosphorylation in response to P. aeruginosa exposure through a CFTR-dependent mechanism. These results suggest that ORKAMBI has anti-inflammatory properties that could decrease lung inflammation and contribute to the observed beneficial impact of this treatment in CF patients.

Persistent oseltamivir-resistant pandemic influenza A/H1N1 infection in an adult with cystic fibrosis

PubMed Central

Flight, William George; Bright-Thomas, Rowland; Mutton, Kenneth; Webb, Kevin; Jones, Andrew

2011-01-01

The authors report the case of a 25-year-old patient with cystic fibrosis (CF) who developed pandemic influenza A/H1N1 during a visit to the USA in August 2010. The patient has severe CF lung disease and takes maintenance oral corticosteroids. The influenza virus was positive for the H275Y oseltamivir-resistance mutation despite the patient never having received oseltamivir. The patient has remained sputum-positive for over 4 months despite inhaled zanamivir therapy. This is the first reported case of transmission of oseltamivir-resistant H1N1 influenza to a patient with CF. The frequency of prolonged sputum carriage of pandemic influenza and transmission of oseltamivir-resistant strains are unknown on a population level. However, if our observations are replicated in other CF patients, they are potentially of considerable importance to clinical and infection-control practices in this patient group. PMID:22696672

Cystic fibrosis carriership and tuberculosis: hints toward an evolutionary selective advantage based on data from the Brazilian territory.

PubMed

Bosch, Lander; Bosch, Barbara; De Boeck, Kris; Nawrot, Tim; Meyts, Isabelle; Vanneste, Dominique; Le Bourlegat, Cleonice Alexandre; Croda, Julio; da Silva Filho, Luiz Vicente Ribeiro Ferreira

2017-05-12

The reason why Cystic Fibrosis (CF) is the most common fatal genetic disease among Caucasians has been incompletely studied. We aimed at deepening the hypothesis that CF carriers have a relative protection against Mycobacterium tuberculosis (Mtb) infection. Applying spatial epidemiology, we studied the link between CF carriership rate and tuberculosis (TB) incidence in Brazil. We corrected for 5 potential environmental and 2 immunological confounders in this relation: monthly income, sanitary provisions, literacy rates, racial composition and population density along with AIDS incidence rates and diabetes mellitus type 2. Smoking data were incomplete and not available for analysis. A significant, negative correlation between CF carriership rate and TB incidence, independent of any of the seven confounders was found. We provide exploratory support for the hypothesis that carrying a single CFTR mutation arms against Mtb infections.

Risk factors for hepatic steatosis in adults with cystic fibrosis: Similarities to non-alcoholic fatty liver disease.

PubMed

Ayoub, Fares; Trillo-Alvarez, Cesar; Morelli, Giuseppe; Lascano, Jorge

2018-01-27

To investigate the clinical, biochemical and imaging characteristics of adult cystic fibrosis (CF) patients with hepatic steatosis as compared to normal CF controls. We performed a retrospective review of adult CF patients in an academic outpatient setting during 2016. Baseline characteristics, genetic mutation analysis as well as laboratory values were collected. Abdominal imaging (ultrasound, computed tomography, magnetic resonance) was used to determine presence of hepatic steatosis. We compare patients with hepatic steatosis to normal controls. Data was collected on 114 patients meeting inclusion criteria. Seventeen patients (14.9%) were found to have hepatic steatosis on imaging. Being overweight (BMI > 25) ( P = 0.019) and having a higher ppFEV1 (75 vs 53, P = 0.037) were significantly associated with hepatic steatosis. Patients with hepatic steatosis had a significantly higher median alanine aminotransferase level (27 vs 19, P = 0.048). None of the hepatic steatosis patients had frank CF liver disease, cirrhosis or portal hypertension. We found no significant association with pancreatic insufficiency or CF related diabetes. Hepatic steatosis appears to be a clinically and phenotypically distinct entity from CF liver disease. The lack of association with malnourishment and the significant association with higher BMI and higher ppFEV1 demonstrate similarities with non-alcoholic fatty liver disease. Long term prospective studies are needed to ascertain whether CF hepatic steatosis progresses to fibrosis and cirrhosis.

Increased apical Na+ permeability in cystic fibrosis is supported by a quantitative model of epithelial ion transport

PubMed Central

O’Donoghue, Donal L; Dua, Vivek; Moss, Guy W J; Vergani, Paola

2013-01-01

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes an anion channel. In the human lung CFTR loss causes abnormal ion transport across airway epithelial cells. As a result CF individuals produce thick mucus, suffer persistent bacterial infections and have a much reduced life expectancy. Trans-epithelial potential difference (Vt) measurements are routinely carried out on nasal epithelia of CF patients in the clinic. CF epithelia exhibit a hyperpolarised basal Vt and a larger Vt change in response to amiloride (a blocker of the epithelial Na+ channel, ENaC). Are these altered bioelectric properties solely a result of electrical coupling between the ENaC and CFTR currents, or are they due to an increased ENaC permeability associated with CFTR loss? To examine these issues we have developed a quantitative mathematical model of human nasal epithelial ion transport. We find that while the loss of CFTR permeability hyperpolarises Vt and also increases amiloride-sensitive Vt, these effects are too small to account for the magnitude of change observed in CF epithelia. Instead, a parallel increase in ENaC permeability is required to adequately fit observed experimental data. Our study provides quantitative predictions for the complex relationships between ionic permeabilities and nasal Vt, giving insights into the physiology of CF disease that have important implications for CF therapy. PMID:23732645

Cystic Fibrosis Revisited - a Review Study.

PubMed

Klimova, Blanka; Kuca, Kamil; Novotny, Michal; Maresova, Petra

2017-01-01

Cystic fibrosis (CF) is an incurable, chronic disease, which causes severe damages to respiratory and digestive tracts. It is the most common genetically inherited disease among caucasians. This disease is caused by defects in CF genes, the so-called mutations in cystic fibrosis transmembrane conductance regulator (CFTR) gene population. At present over 100,000 people suffer from this disease worldwide. The purpose of this review study is to describe the pathophysiology of CF and provide the latest information on its diagnosis and treatment therapies with respect to the improvement of patient's quality of life and emphasis on targeted specialized care. The methodological approaches include a method of literature review of available sources exploring the issue of cystic fibrosis both from a global and specific perspective point of view. A search was performed in the databases PubMed, MEDLINE, Web of Science, Scopus, Springer and ScienceDirect. Furthermore, other sources cited in the analyzed studies were also examined. On the basis of evaluation of these literature sources, the research issue was explored. The main benefits (e.g., specialized centres for the treatment of CF exist or a new breakthrough in the gene therapy of CF has been made) and limitations (e.g., comorbidity of CF, lifelong and costly treatment, or adverse impact on patient's and caregiver's quality of life) in the treatment of narcolepsy are highlighted. CF requires an integrated treatment approach in specialized CF centers, involving various factors contributing to a better patient's state of health in the form of relevant and well-balanced non-pharmacological and pharmacological therapies. In addition, further large scale clinical trials are needed in order to develop compounds that are aimed at the most common classes of CFTR. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Development of positive control materials for DNA-based detection of cystic fibrosis: Cloning and sequencing of 31 mutations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iovannisci, D.; Brown, C.; Winn-Deen, E.

1994-09-01

The cloning and sequencing of the gene associated with cystic fibrosis (CF) now provides the opportunity for earlier detection and carrier screening through DNA-based detection schemes. To date, over 300 mutations have been reported to the CF Consortium; however, only 30 mutations have been observed frequently enough world-wide to warrant routine screening. Many of these mutations are not available as cloned material or as established tissue culture cell lines to aid in the development of DNA-based detection assays. We have therefore cloned the 30 most frequently reported mutations, plus the mutation R347H due to its association with male infertility (31more » mutations, total). Two approaches were employed: direct PCR amplification, where mutations were available from patient sources, and site-directed PCR mutagenesis of normal genomic DNA to generate the remaining mutations. After amplification, products were cloned into a sequencing vector, bacterial transformants were screened by a novel method (PCR/oligonucleotide litigation assay/sequence-coded separation), and plamid DNA sequences determined by automated fluorescent methods on the Applied Biosystems 373A. Mixing of the clones allows the construction of artificial genotypes useful as positive control material for assay validation. A second round of mutagenesis, resulting in the construction of plasmids bearing multiple mutations, will be evaluated for their utility as reagent control materials in kit development.« less

Infertility due to congenital absence of vas deferens in mainly caused by variable exon 9 skipping of the CFTR gene in heterozygous males for cystic fibrosis mutations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chillon, M.; Casals, T.; Nunes, V.

1994-09-01

About 65% or the individuals with congenital bilateral absence of the vas deferens (CBAVD) have mutations in at least one of the CFTR alleles. We have studied the phenotypic effects of the CFTR gene intron 8 polyT tract 5T allele in 90 CBAVD subjects and in parents of CF patients. This group was compared with normal individuals, and with fathers and mothers of CF patients. Allele 5T was significantly associated with CBAVD (19.6%) when compared to the general population (5.2%) ({chi}{sup 2} = 33.3%; p<<0.0001). It was represented poorly in fathers of CF patients (1.3%). Mutations were identified in onemore » (60%) or both CFTR alleles (8.9%) of CBAVD patients. Heterozygosity for the 5T allele was strongly associated with heterozygosity for CF mutations ({chi}{sup 2} = 10.9; p<0.0004). The strong correlation between allele 5T and CBAVD, together with the low frequency of this allele in fathers of CF patients, demonstrates that variable {Delta}exon 9 produces infertility in males if associated with a CF mutation on the other chromosome. The 30% of CBAVD cases with only one CFTR mutation and without a 5T-allele may be due to other molecular mechanisms involving CFTR, distinct from {Delta}exon 9. Since there is a relatively high proportion of CBAVD without CF mutations (25%), other gene(s), distinct from CFTR, may have a role in the CBAVD phenotype.« less

Interaction among variants in the SLC gene family (SLC6A14, SLC26A9, SLC11A1, and SLC9A3) and CFTR mutations with clinical markers of cystic fibrosis.

PubMed

Pereira, Stephanie V N; Ribeiro, Jose D; Bertuzzo, Carmen S; Marson, Fernando A L

2018-04-10

Cystic fibrosis (CF) is due to dysfunction of the CFTR channel and function of this channel is, in turn, affected by modifier genes that can impact the clinical phenotype. In this context, we analyzed the interaction among rs3788766*SLC6A14, rs7512462*SLC26A9, rs17235416*SLC11A1, and rs17563161*SLC9A3 variants, CFTR mutations and 40 CF severity markers by the Multifactor Dimensionality Reduction (MDR) model. A total of 164 patients with CF were included in the study. The variants in the modifier genes were identified by real-time PCR and the genotype of the CFTR gene in the diagnostic routine. Analysis of interaction between variants, CFTR mutations groupings and demographic, clinical and laboratory data were performed by the MDR. There were interaction between the rs3788766, rs7512462, rs17235416, and rs17563161 variants, and CFTR mutations with pancreatic insufficiency (PI), onset of digestive symptoms, and presence of mucoid Pseudomonas aeruginosa. Regarding PI, the interaction was observed for CFTR*rs17563161 (P-value = 0.015). Also, for onset of digestive symptoms the interaction was observed for CFTR*rs3788766*rs7512462*rs17235416*rs17563161 (P-value = 0.036). Considering the presence of mucoid P. aeruginosa, the interaction occurred for CFTR*rs3788766*rs7512462*rs17563161 (P-value = 0.035). Interaction between variants in the SLC family genes and the grouping for CFTR mutations were associated with PI, onset of digestive symptoms and mucoid P. aeruginosa, being important to determine one of the factors that may cause the diversity among the patients with CF. © 2018 Wiley Periodicals, Inc.

The ΔF508 Mutation in the Cystic Fibrosis Transmembrane Conductance Regulator Is Associated With Progressive Insulin Resistance and Decreased Functional β-Cell Mass in Mice.

PubMed

Fontés, Ghislaine; Ghislain, Julien; Benterki, Isma; Zarrouki, Bader; Trudel, Dominique; Berthiaume, Yves; Poitout, Vincent

2015-12-01

Cystic fibrosis (CF) is the result of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). CF-related diabetes affects 50% of adult CF patients. How CFTR deficiency predisposes to diabetes is unknown. Herein, we examined the impact of the most frequent cftr mutation in humans, deletion of phenylalanine at position 508 (ΔF508), on glucose homeostasis in mice. We compared ΔF508 mutant mice with wild-type (WT) littermates. Twelve-week-old male ΔF508 mutants had lower body weight, improved oral glucose tolerance, and a trend toward higher insulin tolerance. Glucose-induced insulin secretion was slightly diminished in ΔF508 mutant islets, due to reduced insulin content, but ΔF508 mutant islets were not more sensitive to proinflammatory cytokines than WT islets. Hyperglycemic clamps confirmed an increase in insulin sensitivity with normal β-cell function in 12- and 18-week-old ΔF508 mutants. In contrast, 24-week-old ΔF508 mutants exhibited insulin resistance and reduced β-cell function. β-Cell mass was unaffected at 11 weeks of age but was significantly lower in ΔF508 mutants versus controls at 24 weeks. This was not associated with gross pancreatic pathology. We conclude that the ΔF508 CFTR mutation does not lead to an intrinsic β-cell secretory defect but is associated with insulin resistance and a β-cell mass deficit in aging mutants. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Whole-gene CFTR sequencing combined with digital RT-PCR improves genetic diagnosis of cystic fibrosis.

PubMed

Straniero, Letizia; Soldà, Giulia; Costantino, Lucy; Seia, Manuela; Melotti, Paola; Colombo, Carla; Asselta, Rosanna; Duga, Stefano

2016-12-01

Despite extensive screening, 1-5% of cystic fibrosis (CF) patients lack a definite molecular diagnosis. Next-generation sequencing (NGS) is making affordable genetic testing based on the identification of variants in extended genomic regions. In this frame, we analyzed 23 CF patients and one carrier by whole-gene CFTR resequencing: 4 were previously characterized and served as controls; 17 were cases lacking a complete diagnosis after a full conventional CFTR screening; 3 were consecutive subjects referring to our centers, not previously submitted to any screening. We also included in the custom NGS design the coding portions of the SCNN1A, SCNN1B and SCNN1G genes, encoding the subunits of the sodium channel ENaC, which were found to be mutated in CF-like patients. Besides 2 novel SCNN1B missense mutations, we identified 22 previously-known CFTR mutations, including 2 large deletions (whose breakpoints were precisely mapped), and novel deep-intronic variants, whose role on splicing was excluded by ex-vivo analyses. Finally, for 2 patients, compound heterozygotes for a CFTR mutation and the intron-9c.1210-34TG [11-12] T 5 allele-known to be associated with decreased CFTR mRNA levels-the molecular diagnosis was implemented by measuring the residual level of wild-type transcript by digital reverse transcription polymerase chain reaction performed on RNA extracted from nasal brushing.

Potential impact on fertility of new systemic therapies for cystic fibrosis.

PubMed

Jones, Gareth Huw; Walshaw, Martin John

2015-10-01

Cystic fibrosis is primarily considered a respiratory disease with superadded pancreatic dysfunction; however the underlying genetic mutation results in the abnormal function of cells throughout the body - including tissues involved in reproduction. Practically all males and up to 50% of females with CF will suffer fertility issues - the causes of which are multifactorial and could be improved by treatments that target the underlying physiological deficit, such as ivacaftor. We consider the mechanisms by which the rapidly developing field of systemic treatments for CF could impact on the fertility of this group and review the available real world evidence. Copyright © 2015 Elsevier Ltd. All rights reserved.

Instability of the insertional mutation in CftrTgH(neoim)Hgu cystic fibrosis mouse model

PubMed Central

Charizopoulou, Nikoletta; Jansen, Silke; Dorsch, Martina; Stanke, Frauke; Dorin, Julia R; Hedrich, Hans-Jürgen; Tümmler, Burkhard

2004-01-01

Background A major boost to the cystic fibrosis disease research was given by the generation of various mouse models using gene targeting in embryonal stem cells. Moreover, the introduction of the same mutation on different inbred strains generating congenic strains facilitated the search for modifier genes. From the original CftrTgH(neoim)Hgu CF mouse model we have generated using strict brother × sister mating two inbred CftrTgH(neoim)Hgu mouse lines (CF/1 and CF/3). Thereafter, the insertional mutation was introgressed from CF/3 into three inbred backgrounds (C57BL/6, BALB/c, DBA/2J) generating congenic animals. In every backcross cycle germline transmission of the insertional mutation was monitored by direct probing the insertion via Southern RFLP. In order to bypass this time consuming procedure we devised an alternative PCR based protocol whereby mouse strains are differentiated at the Cftr locus by Cftr intragenic microsatellite genotypes that are tightly linked to the disrupted locus. Results Using this method we were able to identify animals carrying the insertional mutation based upon the differential haplotypic backgrounds of the three inbred strains and the mutant CftrTgH(neoim)Hgu at the Cftr locus. Moreover, this method facilitated the identification of the precise vector excision from the disrupted Cftr locus in two out of 57 typed animals. This reversion to wild type status took place without any loss of sequence revealing the instability of insertional mutations during the production of congenic animals. Conclusions We present intragenic microsatellite markers as a tool for fast and efficient identification of the introgressed locus of interest in the recipient strain during congenic animal breeding. Moreover, the same genotyping method allowed the identification of a vector excision event, posing questions on the stability of insertional mutations in mice. PMID:15102331

Determination of CFTR densities in erythrocyte plasma membranes using recognition imaging

NASA Astrophysics Data System (ADS)

Ebner, Andreas; Nikova, Dessy; Lange, Tobias; Häberle, Johannes; Falk, Sabine; Dübbers, Angelika; Bruns, Reimer; Hinterdorfer, Peter; Oberleithner, Hans; Schillers, Hermann

2008-09-01

CFTR (cystic fibrosis transmembrane conductance regulator) is a cAMP-regulated chloride (Cl-) channel that plays an important role in salt and fluid movement across epithelia. Cystic fibrosis (CF), the most common genetic disease among Caucasians, is caused by mutations in the gene encoding CFTR. The most predominant mutation, F508del, disturbs CFTR protein trafficking, resulting in a reduced number of CFTR in the plasma membrane. Recent studies indicate that CFTR is not only found in epithelia but also in human erythrocytes. Although considerable attempts have been made to quantify CFTR in cells, conclusions on numbers of CFTR molecules localized in the plasma membrane have been drawn indirectly. AFM has the power to provide the needed information, since both sub-molecular spatial resolution and direct protein recognition via antibody-antigen interaction can be observed. We performed a quantification study of the CFTR copies in erythrocyte membranes at the single molecule level, and compared the difference between healthy donors and CF patients. We detected that the number of CFTR molecules is reduced by 70% in erythrocytes of cystic fibrosis patients.

Effectiveness of ivacaftor in cystic fibrosis patients with non-G551D gating mutations.

PubMed

Guimbellot, Jennifer; Solomon, George M; Baines, Arthur; Heltshe, Sonya L; VanDalfsen, Jill; Joseloff, Elizabeth; Sagel, Scott D; Rowe, Steven M

2018-04-20

The cystic fibrosis transmembrane conductance regulator (CFTR) potentiator ivacaftor is approved for patients with CF with gating and residual function CFTR mutations. We report the results of an observational study investigating its effects in CF patients with non-G551D gating mutations. Patients with non-G551D gating mutations were recruited to an open-label study evaluating ivacaftor. Primary outcomes included: lung function, sweat chloride, weight gain, and quality of life scores. Twenty-one subjects were enrolled and completed 6 months follow-up on ivacaftor; mean age was 25.6 years with 52% <18. Baseline ppFEV 1 was 68% and mean sweat chloride 89.6 mEq/L. Participants experienced significant improvements in ppFEV 1 (mean absolute increase of 10.9% 95% CI = [2.6,19.3], p = 0.0134), sweat chloride (-48.6 95% CI = [-67.4,-29.9], p < 0.0001), and weight (5.1 kg, 95% CI = [2.8, 7.3], p = 0.0002). Patients with non-G551D gating mutations experienced improved lung function, nutritional status, and quality of life. This study supports ongoing use of ivacaftor for patients with these mutations. Copyright © 2018. Published by Elsevier B.V.

Longevity of Patients With Cystic Fibrosis in 2000 to 2010 and Beyond: Survival Analysis of the Cystic Fibrosis Foundation Patient Registry

PubMed Central

MacKenzie, Todd; Gifford, Alex H.; Sabadosa, Kathryn A.; Quinton, Hebe B.; Knapp, Emily A.; Goss, Christopher H.; Marshall, Bruce C.

2015-01-01

Background Advances in treatments for cystic fibrosis (CF) continue to extend survival. An updated estimate of survival is needed for better prognostication and to anticipate evolving adult care needs. Objective To characterize trends in CF survival between 2000 and 2010 and to project survival for children born and diagnosed with the disease in 2010. Design Registry-based study. Setting 110 Cystic Fibrosis Foundation–accredited care centers in the United States. Patients All patients represented in the Cystic Fibrosis Foundation Patient Registry (CFFPR) between 2000 and 2010. Measurements Survival was modeled with respect to age, age at diagnosis, gender, race or ethnicity, F508del mutation status, and symptoms at diagnosis. Results Between 2000 and 2010, the number of patients in the CFFPR increased from 21 000 to 26 000, median age increased from 14.3 to 16.7 years, and adjusted mortality decreased by 1.8% per year (95% CI, 0.5% to 2.7%). Males had a 19% (CI, 13% to 24%) lower adjusted risk for death than females. Median survival of children born and diagnosed with CF in 2010 is projected to be 37 years (CI, 35 to 39 years) for females and 40 years (CI, 39 to 42 years) for males if mortality remains at 2010 levels and more than 50 years if mortality continues to decrease at the rate observed between 2000 and 2010. Limitations The CFFPR does not include all patients with CF in the United States, and loss to follow-up and missing data were observed. Additional analyses to address these limitations suggest that the survival projections are conservative. Conclusion Children born and diagnosed with CF in the United States in 2010 are expected to live longer than those born earlier. This has important implications for prognostic discussions and suggests that the health care system should anticipate greater numbers of adults with CF. Primary Funding Source Cystic Fibrosis Foundation. PMID:25133359

Lung pathology in response to repeated exposure to Staphylococcus aureus in congenic residual function cystic fibrosis mice does not increase in response to decreased CFTR levels or increased bacterial load.

PubMed

Davidson, Donald J; Webb, Sheila; Teague, Peter; Govan, John R W; Dorin, Julia R

2004-01-01

To establish the role of defects in murine Cftr in the susceptibility to Staphylococcus aureus lung disease using mouse models of cystic fibrosis (CF), congenic or inbred strains. We describe the histopathological analyses of CF mice repeatedly exposed by aerosolisation to a CF isolate of S. aureus, using residual function Cftr mice and compound heterozygotes generated by intercrossing these with Cftr 'null' mice, all congenic on the C57Bl6/N background. We demonstrate that mice congenic on the C57Bl/6 background develop significantly more severe lung pathology than non-CF littermates in response to repeated exposure to the most frequent early CF lung pathogen S. aureus. Furthermore, reducing the level of Cftr by half in compound heterozygote mice does not impact upon disease severity, even in response to an increased bacterial dose. These results are consistent with an airway clearance defect, or abnormal inflammatory response secondary to Cftr mutation. These studies confirm the primary role for Cftr mutation in the development of this lung phenotype. In addition, these results demonstrate that a further 50% decrease in residual wild-type Cftr mRNA levels in this model does not impact the severity of the histopathological response to S. aureus, suggesting a critical threshold level for functional CFTR. Copyright 2004 S. Karger AG, Basel

Increased Expression of Plasma-Induced ABCC1 mRNA in Cystic Fibrosis.

PubMed

Ideozu, Justin E; Zhang, Xi; Pan, Amy; Ashrafi, Zainub; Woods, Katherine J; Hessner, Martin J; Simpson, Pippa; Levy, Hara

2017-08-11

The ABCC1 gene is structurally and functionally related to the cystic fibrosis transmembrane conductance regulator gene ( CFTR ). Upregulation of ABCC1 is thought to improve lung function in patients with cystic fibrosis (CF); the mechanism underlying this effect is unknown. We analyzed the ABCC1 promoter single nucleotide polymorphism (SNP rs504348), plasma-induced ABCC1 mRNA expression levels, and ABCC1 methylation status and their correlation with clinical variables among CF subjects with differing CFTR mutations. We assigned 93 CF subjects into disease severity groups and genotyped SNP rs504348. For 23 CF subjects and 7 healthy controls, donor peripheral blood mononuclear cells (PBMCs) stimulated with plasma underwent gene expression analysis via qRT-PCR. ABCC1 promoter methylation was analyzed in the same 23 CF subjects. No significant correlation was observed between rs504348 genotypes and CF disease severity, but pancreatic insufficient CF subjects showed increased colonization with any form of Pseudomonas aeruginosa (OR = 3.125, 95% CI: 1.192-8.190) and mucoid P. aeruginosa (OR = 5.075, 95% CI: 1.307-28.620) compared to the pancreatic sufficient group. A significantly higher expression of ABCC1 mRNA was induced by CF plasma compared to healthy control plasma ( p < 0.001). CF subjects with rs504348 (CC/CG) also had higher mRNA expression compared to those with the ancestral GG genotype ( p < 0.005). ABCC1 promoter was completely unmethylated; therefore, we did not detect any association between methylation and CF disease severity. In silico predictions suggested that histone modifications are crucial for regulating ABCC1 expression in PBMCs. Our results suggest that ABCC1 expression has a role in CFTR activity thereby increasing our understanding of the molecular underpinnings of the clinical heterogeneity in CF.

CFTR mutation distribution among U.S. Hispanic and African American individuals: evaluation in cystic fibrosis patient and carrier screening populations.

PubMed

Sugarman, Elaine A; Rohlfs, Elizabeth M; Silverman, Lawrence M; Allitto, Bernice A

2004-01-01

We reviewed CFTR mutation distribution among Hispanic and African American individuals referred for CF carrier screening and compared mutation frequencies to those derived from CF patient samples. Results from CFTR mutation analyses received from January 2001 through September 2003, were analyzed for four populations: Hispanic individuals with a CF diagnosis (n = 159) or carrier screening indication (n = 15,333) and African American individuals with a CF diagnosis (n = 108) or carrier screening indication (n = 8,973). All samples were tested for the same 87 mutation panel. In the Hispanic population, 42 mutations were identified: 30 in the patient population (77.5% detection rate) and 33 among carrier screening referrals. Five mutations not included in the ACMG/ACOG carrier screening panel (3876delA, W1089X, R1066C, S549N, 1949del84) accounted for 7.55% detection in patients and 5.58% among carriers. Among African American referrals, 33 different mutations were identified: 21 in the patient population (74.4% detection) and 23 in the carrier screening population. Together, A559T and 711+5G>A were observed at a detection rate of 3.71% in CF patients and 6.38% in carriers. The mutation distribution seen in both the carrier screening populations reflected an increased frequency of mutations with variable expression such as D1152H, R117H, and L206W. A detailed analysis of CFTR mutation distribution in the Hispanic and African American patient and carrier screening populations demonstrates that a diverse group of mutations is most appropriate for diagnostic and carrier screening in these populations. To best serve the increasingly diverse U.S. population, ethnic-specific mutations should be included in mutation panels.

Comparison of Ambient and Atmospheric Pressure Ion Sources for Cystic Fibrosis Exhaled Breath Condensate Ion Mobility-Mass Spectrometry Metabolomics

NASA Astrophysics Data System (ADS)

Zang, Xiaoling; Pérez, José J.; Jones, Christina M.; Monge, María Eugenia; McCarty, Nael A.; Stecenko, Arlene A.; Fernández, Facundo M.

2017-08-01

Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The vast majority of the mortality is due to progressive lung disease. Targeted and untargeted CF breath metabolomics investigations via exhaled breath condensate (EBC) analyses have the potential to expose metabolic alterations associated with CF pathology and aid in assessing the effectiveness of CF therapies. Here, transmission-mode direct analysis in real time traveling wave ion mobility spectrometry time-of-flight mass spectrometry (TM-DART-TWIMS-TOF MS) was tested as a high-throughput alternative to conventional direct infusion (DI) electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) methods, and a critical comparison of the three ionization methods was conducted. EBC was chosen as the noninvasive surrogate for airway sampling over expectorated sputum as EBC can be collected in all CF subjects regardless of age and lung disease severity. When using pooled EBC collected from a healthy control, ESI detected the most metabolites, APCI a log order less, and TM-DART the least. TM-DART-TWIMS-TOF MS was used to profile metabolites in EBC samples from five healthy controls and four CF patients, finding that a panel of three discriminant EBC metabolites, some of which had been previously detected by other methods, differentiated these two classes with excellent cross-validated accuracy.

Detection of 98. 5% of the mutations in 200 Belgian cystic fibrosis alleles by reverse dot-blot and sequencing of the complete coding region and exon/intron junctions of the CFTR gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cuppens, H.; Marynen, P.; Cassiman, J.J.

1993-12-01

The authors have previously shown that about 85% of the mutations in 194 Belgian cystic fibrosis alleles could be detected by a reverse dot-blot assay. In the present study, 50 Belgian chromosomes were analyzed for mutations in the cystic fibrosis transmembrane conductance regulator gene by means of direct solid phase automatic sequencing of PCR products of individual exons. Twenty-six disease mutations and 14 polymorphisms were found. Twelve of these mutations and 3 polymorphisms were not described before. With the exception of one mutant allele carrying two mutations, these mutations were the only mutations found in the complete coding region andmore » their exon/intron boundaries. The total sensitivity of mutant CF alleles that could be identified was 98.5%. Given the heterogeneity of these mutations, most of them very rare, CFTR mutation screening still remains rather complex in the population, and population screening, whether desirable or not, does not appear to be technically feasible with the methods currently available. 24 refs., 1 fig., 2 tabs.« less

Validation of a Nutrition Screening Tool for Pediatric Patients with Cystic Fibrosis.

PubMed

Souza Dos Santos Simon, Miriam Isabel; Forte, Gabriele Carra; da Silva Pereira, Juliane; da Fonseca Andrade Procianoy, Elenara; Drehmer, Michele

2016-05-01

In cystic fibrosis (CF), nutrition diagnosis is of critical relevance because the early identification of nutrition-related compromise enables early, adequate intervention and, consequently, influences patient prognosis. Up to now, there has not been a validated nutrition screening tool that takes into consideration clinical variables. To validate a specific nutritional risk screening tool for patients with CF based on clinical variables, anthropometric parameters, and dietary intake. Cross-sectional study. The nutrition screening tool was compared with a risk screening tool proposed by McDonald and the Cystic Fibrosis Foundation criteria. Patients aged 6 to 18 years, with a diagnosis of CF confirmed by two determinations of elevated chloride level in sweat (sweat test) and/or by identification of two CF-associated genetic mutations who were receiving follow-up care through the outpatient clinic of a Cystic Fibrosis Treatment Center. Earlier identification of nutritional risk in CF patients aged 6 to 18 years when a new screening tool was applied. Agreement among the tested methods was assessed by means of the kappa coefficient for categorical variables. Sensitivity, specificity, and accuracy values were calculated. The significance level was set at 5% (P<0.05). Statistical analyses were carried out in PASW Statistics for Windows version 18.0 (2009, SPSS Inc). Eighty-two patients (49% men, aged 6 to 18 years) were enrolled in the study. The agreement between the proposed screening tool and the tool for screening nutritional risk for CF by the McDonald method was good (κ=0.804; P<0.001) and the sensitivity and specificity was 85% and 95%, respectively. Agreement with the Cystic Fibrosis Foundation criteria was lower (κ=0.418; P<0.001), and the sensitivity and specificity were both 72%. The proposed screening tool with defined clinical variables promotes earlier identification of nutritional risk in pediatric patients with CF. Copyright © 2016 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Growth phenotypes of Pseudomonas aeruginosa lasR mutants adapted to the airways of cystic fibrosis patients

PubMed Central

D’Argenio, David A.; Wu, Manhong; Hoffman, Lucas R.; Kulasekara, Hemantha D.; Déziel, Eric; Smith, Eric E.; Nguyen, Hai; Ernst, Robert K.; Larson Freeman, Theodore J.; Spencer, David H.; Brittnacher, Mitchell; Hayden, Hillary S.; Selgrade, Sara; Klausen, Mikkel; Goodlett, David R.; Burns, Jane L.; Ramsey, Bonnie W.; Miller, Samuel I.

2009-01-01

Summary The opportunistic pathogen Pseudomonas aeruginosa undergoes genetic change during chronic airway infection of cystic fibrosis (CF) patients. One common change is a mutation inactivating lasR, which encodes a transcriptional regulator that responds to a homoserine lactone signal to activate expression of acute virulence factors. Colonies of lasR mutants visibly accumulated the iridescent intercellular signal 4-hydroxy-2-heptylquinoline. Using this colony phenotype, we identified P. aeruginosa lasR mutants that emerged in the airway of a CF patient early during chronic infection, and during growth in the laboratory on a rich medium. The lasR loss-of-function mutations in these strains conferred a growth advantage with particular carbon and nitrogen sources, including amino acids, in part due to increased expression of the catabolic pathway regulator CbrB. This growth phenotype could contribute to selection of lasR mutants both on rich medium and within the CF airway, supporting a key role for bacterial metabolic adaptation during chronic infection. Inactivation of lasR also resulted in increased β-lactamase activity that increased tolerance to ceftazidime, a widely used β-lactam antibiotic. Loss of LasR function may represent a marker of an early stage in chronic infection of the CF airway with clinical implications for antibiotic resistance and disease progression. PMID:17493132

Targeting the Intracellular Environment in Cystic Fibrosis: Restoring Autophagy as a Novel Strategy to Circumvent the CFTR Defect

PubMed Central

Villella, Valeria Rachela; Esposito, Speranza; Bruscia, Emanuela M.; Maiuri, Maria Chiara; Raia, Valeria; Kroemer, Guido; Maiuri, Luigi

2013-01-01

Cystic fibrosis (CF) patients harboring the most common deletion mutation of the CF transmembrane conductance regulator (CFTR), F508del, are poor responders to potentiators of CFTR channel activity which can be used to treat a small subset of CF patients who genetically carry plasma membrane (PM)-resident CFTR mutants. The misfolded F508del-CFTR protein is unstable in the PM even if rescued by pharmacological agents that prevent its intracellular retention and degradation. CF is a conformational disease in which defective CFTR induces an impressive derangement of general proteostasis resulting from disabled autophagy. In this review, we discuss how rescuing Beclin 1 (BECN1), a major player of autophagosome formation, either by means of direct gene transfer or indirectly by administration of proteostasis regulators, could stabilize F508del-CFTR at the PM. We focus on the relationship between the improvement of peripheral proteostasis and CFTR PM stability in F508del-CFTR homozygous bronchial epithelia or mouse lungs. Moreover, this article reviews recent pre-clinical evidence indicating that targeting the intracellular environment surrounding the misfolded mutant CFTR instead of protein itself could constitute an attractive therapeutic option to sensitize patients carrying the F508del-CFTR mutation to the beneficial action of CFTR potentiators on lung inflammation. PMID:23346057

[CF Lung Disease - a German S3 Guideline: Module 2: Diagnostics and Treatment in Chronic Infection with Pseudomonas aeruginosa].

PubMed

Schwarz, C; Schulte-Hubbert, B; Bend, J; Abele-Horn, M; Baumann, I; Bremer, W; Brunsmann, F; Dieninghoff, D; Eickmeier, O; Ellemunter, H; Fischer, R; Grosse-Onnebrink, J; Hammermann, J; Hebestreit, H; Hogardt, M; Hügel, C; Hug, M; Illing, S; Jung, A; Kahl, B; Koitschev, A; Mahlberg, R; Mainz, J G; Mattner, F; Mehl, A; Möller, A; Muche-Borowski, C; Nüßlein, T; Puderbach, M; Renner, S; Rietschel, E; Ringshausen, F C; Schmidt, S; Sedlacek, L; Sitter, H; Smaczny, C; Tümmler, B; Vonberg, R; Wielpütz, M O; Wilkens, H; Wollschläger, B; Zerlik, J; Düesberg, U; van Koningsbruggen-Rietschel, S

2018-05-01

Cystic Fibrosis (CF) is the most common autosomal-recessive genetic disease affecting approximately 8000 people in Germany. The disease is caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene leading to dysfunction of CFTR, a transmembrane chloride channel. This defect causes insufficient hydration of the epithelial lining fluid which leads to chronic inflammation of the airways. Recurrent infections of the airways as well as pulmonary exacerbations aggravate chronic inflammation, lead to pulmonary fibrosis and tissue destruction up to global respiratory insufficiency, which is responsible for the mortality in over 90 % of patients. The main aim of pulmonary treatment in CF is to reduce pulmonary inflammation and chronic infection. Pseudomonas aeruginosa ( Pa ) is the most relevant pathogen in the course of CF lung disease. Colonization and chronic infection are leading to additional loss of pulmonary function. There are many possibilities to treat Pa -infection. This is a S3-clinical guideline which implements a definition for chronic Pa -infection and demonstrates evidence-based diagnostic methods and medical treatment for Pa -infection in order to give guidance for individual treatment options. © Georg Thieme Verlag KG Stuttgart · New York.

New possibilities for population control of cystic fibrosis.

PubMed Central

Dodge, J. A.; Boulyjenkov, V.

1992-01-01

Cystic fibrosis (CF), which is caused exclusively by mutation of a single gene, is inherited in autosomal recessive fashion and is the commonest such disorder in populations of Caucasian origin. Although much progress has been made during the last 50 years in its clinical management, with a corresponding improvement in the mean life expectancy in developed countries from a few months to a few decades, it remains incurable and a complete understanding of its biochemical basis is still being sought. Consequently, attention has been given to the possibility of screening for carriers of the defective gene, who represent up to 5% in some populations, so that they may be given appropriate genetic counselling. Whereas previously carriers were identified only when they became parents of affected children, in recent years carriers who were more distantly related to CF patients have often been identified by means of genetic linkage techniques. A new strategy for the control of CF at the population level is now proposed. It is based on the report of a joint WHO/ICF(M)A (International Cystic Fibrosis (Mucoviscidosis) Association) Task Force on CF which met in November 1990. PMID:1464143

The HDAC inhibitor SAHA does not rescue CFTR membrane expression in Cystic Fibrosis.

PubMed

Bergougnoux, Anne; Petit, Aurélie; Knabe, Lucie; Bribes, Estelle; Chiron, Raphaël; De Sario, Albertina; Claustres, Mireille; Molinari, Nicolas; Vachier, Isabelle; Taulan-Cadars, Magali; Bourdin, Arnaud

2017-07-01

The development of suitable Cystic Fibrosis (CF) models for preclinical bench tests of therapeutic candidates is challenging. Indeed, the validation of molecules to rescue the p.Phe508del-CFTR channel (encoded by the Cystic Fibrosis Transmembrane conductance Regulator gene carrying the p.Phe508del mutation) requires taking into account their overall effects on the epithelium. Suberoylanilide Hydroxamic Acid (SAHA), a histone deacetylase inhibitor (HDACi), was previously shown to be a CFTR corrector via proteostasis modulation in CFTR-deficient immortalized cells. Here, we tested SAHA effects on goblet cell metaplasia using an ex vivo model based on the air-liquid interface (ALI) culture of differentiated airway epithelial cells obtained by nasal scraping from CF patients and healthy controls. Ex vivo epithelium grew successfully in ALI cultures with significant rise in the expression of CFTR and of markers of airway epithelial differentiation compared to monolayer cell culture. SAHA decreased CFTR transcript and protein levels in CF and non-CF epithelia. Whereas SAHA induced lysine hyperacetylation, it did not change histone modifications at the CFTR promoter. SAHA reduced MUC5AC and MUC5B expression and inhibited goblet epithelial cell differentiation. Similar effects were obtained in CF and non-CF epithelia. All the effects were fully reversible within five days from SAHA withdrawal. We conclude that, ex vivo, SAHA modulate the structure of airway epithelia without specific effect on CFTR gene and protein suggesting that HDACi cannot be useful for CF treatment. Copyright © 2017. Published by Elsevier Ltd.

Risk factors for hepatic steatosis in adults with cystic fibrosis: Similarities to non-alcoholic fatty liver disease

PubMed Central

Ayoub, Fares; Trillo-Alvarez, Cesar; Morelli, Giuseppe; Lascano, Jorge

2018-01-01

AIM To investigate the clinical, biochemical and imaging characteristics of adult cystic fibrosis (CF) patients with hepatic steatosis as compared to normal CF controls. METHODS We performed a retrospective review of adult CF patients in an academic outpatient setting during 2016. Baseline characteristics, genetic mutation analysis as well as laboratory values were collected. Abdominal imaging (ultrasound, computed tomography, magnetic resonance) was used to determine presence of hepatic steatosis. We compare patients with hepatic steatosis to normal controls. RESULTS Data was collected on 114 patients meeting inclusion criteria. Seventeen patients (14.9%) were found to have hepatic steatosis on imaging. Being overweight (BMI > 25) (P = 0.019) and having a higher ppFEV1 (75 vs 53, P = 0.037) were significantly associated with hepatic steatosis. Patients with hepatic steatosis had a significantly higher median alanine aminotransferase level (27 vs 19, P = 0.048). None of the hepatic steatosis patients had frank CF liver disease, cirrhosis or portal hypertension. We found no significant association with pancreatic insufficiency or CF related diabetes. CONCLUSION Hepatic steatosis appears to be a clinically and phenotypically distinct entity from CF liver disease. The lack of association with malnourishment and the significant association with higher BMI and higher ppFEV1 demonstrate similarities with non-alcoholic fatty liver disease. Long term prospective studies are needed to ascertain whether CF hepatic steatosis progresses to fibrosis and cirrhosis. PMID:29399276

Within-Host Evolution of Burkholderia pseudomallei during Chronic Infection of Seven Australasian Cystic Fibrosis Patients

PubMed Central

Kidd, Timothy J.; Geake, James B.; Bell, Scott C.; Currie, Bart J.

2017-01-01

ABSTRACT Cystic fibrosis (CF) is a genetic disorder characterized by progressive lung function decline. CF patients are at an increased risk of respiratory infections, including those by the environmental bacterium Burkholderia pseudomallei, the causative agent of melioidosis. Here, we compared the genomes of B. pseudomallei isolates collected between ~4 and 55 months apart from seven chronically infected CF patients. Overall, the B. pseudomallei strains showed evolutionary patterns similar to those of other chronic infections, including emergence of antibiotic resistance, genome reduction, and deleterious mutations in genes involved in virulence, metabolism, environmental survival, and cell wall components. We documented the first reported B. pseudomallei hypermutators, which were likely caused by defective MutS. Further, our study identified both known and novel molecular mechanisms conferring resistance to three of the five clinically important antibiotics for melioidosis treatment. Our report highlights the exquisite adaptability of microorganisms to long-term persistence in their environment and the ongoing challenges of antibiotic treatment in eradicating pathogens in the CF lung. Convergent evolution with other CF pathogens hints at a degree of predictability in bacterial evolution in the CF lung and potential targeted eradication of chronic CF infections in the future. PMID:28400528

Meconium ileus in patients with cystic fibrosis is not a risk factor for clinical deterioration and survival: the Israeli Multicenter Study.

PubMed

Efrati, Ori; Nir, Judith; Fraser, Drora; Cohen-Cymberknoh, Malena; Shoseyov, David; Vilozni, Daphna; Modan-Moses, Dalit; Levy, Ran; Szeinberg, Amir; Kerem, Eitan; Rivlin, Joseph

2010-02-01

Patients with cystic fibrosis (CF) presenting with meconium ileus (MI) tend to have worse outcomes than those without MI. We evaluated the clinical characteristics and survival rates among Israeli patients with CF with and without MI after a prolonged follow-up (15-30 years). A multicenter retrospective study. Forty-nine patients with CF, representing 13.8% of all patients with CF in Israel, presented with MI (current age 17.4 +/- 7.9 years) between 1975 and 2006. They were compared with 38 patients with CF (current age 19.3 +/- 6.5 years) without MI matched by sex and CF transmembrane conductance regulator mutation. A total of 66.2% of patients with MI and 73.6% without MI were followed for a prolonged period (24.9 +/- 2.7 years). Of the patients with MI, 31 were managed operatively, whereas 18 were treated successfully with gastrograffin enema, with similar clinical outcomes. Five patients in the MI group and 3 in the control group died during the study period. Bacterial colonization, z score of body mass index, and pulmonary function tests were similar in patients with and without MI in the long term. In younger patients, many clinical parameters were more prevalent in patients with MI (P = 0.004). However, these differences disappeared after the long-term follow-up (up to 31-years). Patients with CF presenting with MI had similar pulmonary function and nutritional status, as well as survival rates as did the control patients without MI. The distinct genetic mutation found in our population may explain in part the favorable results compared with other studies. In addition, it seems that early diagnosis and treatment of MI in patients with CF may be beneficial, subsequently lowering morbidity, and increasing survival.

Acute administration of ivacaftor to people with cystic fibrosis and a G551D-CFTR mutation reveals smooth muscle abnormalities

PubMed Central

Adam, Ryan J.; Hisert, Katherine B.; Dodd, Jonathan D.; Grogan, Brenda; Launspach, Janice L.; Barnes, Janel K.; Gallagher, Charles G.; Sieren, Jered P.; Gross, Thomas J.; Fischer, Anthony J.; Cavanaugh, Joseph E.; Hoffman, Eric A.; Singh, Pradeep K.; Welsh, Michael J.; McKone, Edward F.; Stoltz, David A.

2016-01-01

BACKGROUND. Airflow obstruction is common in cystic fibrosis (CF), yet the underlying pathogenesis remains incompletely understood. People with CF often exhibit airway hyperresponsiveness, CF transmembrane conductance regulator (CFTR) is present in airway smooth muscle (ASM), and ASM from newborn CF pigs has increased contractile tone, suggesting that loss of CFTR causes a primary defect in ASM function. We hypothesized that restoring CFTR activity would decrease smooth muscle tone in people with CF. METHODS. To increase or potentiate CFTR function, we administered ivacaftor to 12 adults with CF with the G551D-CFTR mutation; ivacaftor stimulates G551D-CFTR function. We studied people before and immediately after initiation of ivacaftor (48 hours) to minimize secondary consequences of CFTR restoration. We tested smooth muscle function by investigating spirometry, airway distensibility, and vascular tone. RESULTS. Ivacaftor rapidly restored CFTR function, indicated by reduced sweat chloride concentration. Airflow obstruction and air trapping also improved. Airway distensibility increased in airways less than 4.5 mm but not in larger-sized airways. To assess smooth muscle function in a tissue outside the lung, we measured vascular pulse wave velocity (PWV) and augmentation index, which both decreased following CFTR potentiation. Finally, change in distensibility of <4.5-mm airways correlated with changes in PWV. CONCLUSIONS. Acute CFTR potentiation provided a unique opportunity to investigate CFTR-dependent mechanisms of CF pathogenesis. The rapid effects of ivacaftor on airway distensibility and vascular tone suggest that CFTR dysfunction may directly cause increased smooth muscle tone in people with CF and that ivacaftor may relax smooth muscle. FUNDING. This work was funded in part from an unrestricted grant from the Vertex Investigator-Initiated Studies Program. PMID:27158673

Coexistence and Within-Host Evolution of Diversified Lineages of Hypermutable Pseudomonas aeruginosa in Long-term Cystic Fibrosis Infections

PubMed Central

Feliziani, Sofía; Moyano, Alejandro J.; Di Rienzo, Julio A.; Krogh Johansen, Helle; Molin, Søren; Smania, Andrea M.

2014-01-01

The advent of high-throughput sequencing techniques has made it possible to follow the genomic evolution of pathogenic bacteria by comparing longitudinally collected bacteria sampled from human hosts. Such studies in the context of chronic airway infections by Pseudomonas aeruginosa in cystic fibrosis (CF) patients have indicated high bacterial population diversity. Such diversity may be driven by hypermutability resulting from DNA mismatch repair system (MRS) deficiency, a common trait evolved by P. aeruginosa strains in CF infections. No studies to date have utilized whole-genome sequencing to investigate within-host population diversity or long-term evolution of mutators in CF airways. We sequenced the genomes of 13 and 14 isolates of P. aeruginosa mutator populations from an Argentinian and a Danish CF patient, respectively. Our collection of isolates spanned 6 and 20 years of patient infection history, respectively. We sequenced 11 isolates from a single sample from each patient to allow in-depth analysis of population diversity. Each patient was infected by clonal populations of bacteria that were dominated by mutators. The in vivo mutation rate of the populations was ∼100 SNPs/year–∼40-fold higher than rates in normo-mutable populations. Comparison of the genomes of 11 isolates from the same sample showed extensive within-patient genomic diversification; the populations were composed of different sub-lineages that had coexisted for many years since the initial colonization of the patient. Analysis of the mutations identified genes that underwent convergent evolution across lineages and sub-lineages, suggesting that the genes were targeted by mutation to optimize pathogenic fitness. Parallel evolution was observed in reduction of overall catabolic capacity of the populations. These findings are useful for understanding the evolution of pathogen populations and identifying new targets for control of chronic infections. PMID:25330091

Changes of CFTR functional measurements and clinical improvements in cystic fibrosis patients with non p.Gly551Asp gating mutations treated with ivacaftor.

PubMed

Mesbahi, Myriam; Shteinberg, Michal; Wilschanski, Michael; Hatton, Aurelie; Nguyen-Khoa, Thao; Friedman, Hannah; Cohen, Michael; Escabasse, Virginie; Le Bourgeois, Muriel; Lucidi, Vicenzina; Sermet-Gaudelus, Isabelle; Bassinet, Laurence; Livnat, Galit

2017-01-01

Ivacaftor, a CFTR potentiator, has been found to improve CFTR function and clinical outcomes in patients with cystic fibrosis (CF) gating mutations. We investigated the effects of ivacaftor on CFTR functional measurement in CF patients carrying gating mutations other than p.Gly551Asp. Two siblings aged 13 and 12 carrying the p.Ser549Asn mutation, two sisters (45 and 43years old) compound heterozygotes for p.Asp1152His and p.Gly1244Glu, a 37year old man homozygous for the p.Gly1244Glu mutation, and a 7year old girl with p.Arg352Gln and p.Gly1244Glu mutations commenced treatment with ivacaftor. NPD was performed in all the patients and approached normal for four patients who had also clinical improvement (p.Ser549Asn compound heterozygotes, and p.Asp1152His/p.Gly1244Glu siblings). Beta-adrenergic sweat chloride secretion performed in thep.Asp1152His/p.Gly1244Glu patients improved significantly. The p.Gly1244Glu mutation homozygous patient, who had undergone an ileal resection with ileostomy and enterocutaneous fistula, did not respond clinically to ivacaftor and did not modify his sweat test. These results highlight the importance of different CFTR activity measurements to explore CFTR modulator efficacy. Copyright © 2016. Published by Elsevier B.V.

CFTR DeltaF508 mutation detection from dried blood samples in the first trimester of pregnancy: a possible routine prenatal screening strategy for cystic fibrosis?

PubMed

Konialis, Christopher P; Hagnefelt, Birgitta; Kazamia, Constantina; Karapanou, Sophia; Pangalos, Constantinos

2007-01-01

The implementation and evaluation of a proposed wide-scale prenatal screening strategy, based on DNA isolated from dried blood spots in the first trimester of pregnancy, for the early detection of pregnancies at risk for cystic fibrosis (CF). The screening was performed in conjunction with routine biochemical marker screening for Down's syndrome risk in the first trimester of pregnancy. DNA was isolated from 1,233 dried blood spots and analyzed for the presence of the CF transmembrane regulator DeltaF508 mutation. Women carriers were offered and accepted the option for additional full testing of their partners in order to assess the risk for the fetus. All 1,233 samples were successfully analyzed, identifying 23 DeltaF508 carriers, corresponding to a DeltaF508 carrier rate of approximately 1/55 (1.8%). All partners of the women carriers were further tested without revealing any need for further prenatal testing in this group. This study reveals the relatively high frequency of the DeltaF508 CF mutation in the Greek population. More importantly, we demonstrate that the proposed prenatal screening strategy, based on the ease and cost-effectiveness of the analysis for the detection of a single common mutation, can be considered as a feasible and practical approach for wide-scale prenatal screening for CF, following the sequential model. It is applied early on in pregnancy, allowing for the timely management of families at risk for the corresponding genetic disorders. Finally, it can easily be extended to include screening for other common genetic disorders in specific population groups.

Inhibition by TNF-alpha and IL-4 of cationic lipid mediated gene transfer in cystic fibrosis tracheal gland cells.

PubMed

Bastonero, Sonia; Gargouri, Myriem; Ortiou, Sandrine; Guéant, Jean-Louis; Merten, Marc D

2005-11-01

In vivo, tracheal gland serous cells highly express the cystic fibrosis transmembrane conductance regulator (cftr) gene. This gene is mutated in the lethal monogenic disease cystic fibrosis (CF). Clinical trials in which the human CFTR cDNA was delivered to the respiratory epithelia of CF patients have resulted in weak and transient gene expression. As CF is characterized by mucus inspissation, airway infection, and severe inflammation, we tested the hypothesis that inflammation and especially two cytokines involved in the Th1/Th2 inflammatory response, interleukin 4 (IL-4) and TNFalpha, could inhibit gene transfer efficiency using a model of human CF tracheal gland cells (CF-KM4) and Lipofectamine reagent as a transfection reagent. The specific secretory defects of CF-KM4 cells were corrected by Lipofectamine-mediated human CFTR gene transfer. However, this was altered when cells were pre-treated with IL-4 and TNFalpha. Inhibition of luciferase reporter gene expression by IL-4 and TNFalpha pre-treated CF-KM4 cells was measured by activity and real-time RT-PCR. Both cytokines induced similar and synergistic inhibition of transgene expression and activity. This cytokine-mediated inhibition could be prevented by anti-inflammatory agents such as glucocorticoids but not by non-steroidal (NSAI) agents. This data suggests that an inflammatory context generated by IL-4 and TNFalpha can inhibit human CFTR gene transfer in CF tracheal gland cells and that glucocorticoids may have a protecting action. Copyright (c) 2005 John Wiley & Sons, Ltd.

Restoration of CFTR function in patients with cystic fibrosis carrying the F508del-CFTR mutation.

PubMed

De Stefano, Daniela; Villella, Valeria R; Esposito, Speranza; Tosco, Antonella; Sepe, Angela; De Gregorio, Fabiola; Salvadori, Laura; Grassia, Rosa; Leone, Carlo A; De Rosa, Giuseppe; Maiuri, Maria C; Pettoello-Mantovani, Massimo; Guido, Stefano; Bossi, Anna; Zolin, Anna; Venerando, Andrea; Pinna, Lorenzo A; Mehta, Anil; Bona, Gianni; Kroemer, Guido; Maiuri, Luigi; Raia, Valeria

2014-01-01

Restoration of BECN1/Beclin 1-dependent autophagy and depletion of SQSTM1/p62 by genetic manipulation or autophagy-stimulatory proteostasis regulators, such as cystamine, have positive effects on mouse models of human cystic fibrosis (CF). These measures rescue the functional expression of the most frequent pathogenic CFTR mutant, F508del, at the respiratory epithelial surface and reduce lung inflammation in Cftr(F508del) homozygous mice. Cysteamine, the reduced form of cystamine, is an FDA-approved drug. Here, we report that oral treatment with cysteamine greatly reduces the mortality rate and improves the phenotype of newborn mice bearing the F508del-CFTR mutation. Cysteamine was also able to increase the plasma membrane expression of the F508del-CFTR protein in nasal epithelial cells from F508del homozygous CF patients, and these effects persisted for 24 h after cysteamine withdrawal. Importantly, this cysteamine effect after washout was further sustained by the sequential administration of epigallocatechin gallate (EGCG), a green tea flavonoid, both in vivo, in mice, and in vitro, in primary epithelial cells from CF patients. In a pilot clinical trial involving 10 F508del-CFTR homozygous CF patients, the combination of cysteamine and EGCG restored BECN1, reduced SQSTM1 levels and improved CFTR function from nasal epithelial cells in vivo, correlating with a decrease of chloride concentrations in sweat, as well as with a reduction of the abundance of TNF/TNF-alpha (tumor necrosis factor) and CXCL8 (chemokine [C-X-C motif] ligand 8) transcripts in nasal brushing and TNF and CXCL8 protein levels in the sputum. Altogether, these results suggest that optimal schedules of cysteamine plus EGCG might be used for the treatment of CF caused by the F508del-CFTR mutation.

Two Small Molecules Restore Stability to a Subpopulation of the Cystic Fibrosis Transmembrane Conductance Regulator with the Predominant Disease-causing Mutation.

PubMed

Meng, Xin; Wang, Yiting; Wang, Xiaomeng; Wrennall, Joe A; Rimington, Tracy L; Li, Hongyu; Cai, Zhiwei; Ford, Robert C; Sheppard, David N

2017-03-03

Cystic fibrosis (CF) is caused by mutations that disrupt the plasma membrane expression, stability, and function of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl - channel. Two small molecules, the CFTR corrector lumacaftor and the potentiator ivacaftor, are now used clinically to treat CF, although some studies suggest that they have counteracting effects on CFTR stability. Here, we investigated the impact of these compounds on the instability of F508del-CFTR, the most common CF mutation. To study individual CFTR Cl - channels, we performed single-channel recording, whereas to assess entire CFTR populations, we used purified CFTR proteins and macroscopic CFTR Cl - currents. At 37 °C, low temperature-rescued F508del-CFTR more rapidly lost function in cell-free membrane patches and showed altered channel gating and current flow through open channels. Compared with purified wild-type CFTR, the full-length F508del-CFTR was about 10 °C less thermostable. Lumacaftor partially stabilized purified full-length F508del-CFTR and slightly delayed deactivation of individual F508del-CFTR Cl - channels. By contrast, ivacaftor further destabilized full-length F508del-CFTR and accelerated channel deactivation. Chronic (prolonged) co-incubation of F508del-CFTR-expressing cells with lumacaftor and ivacaftor deactivated macroscopic F508del-CFTR Cl - currents. However, at the single-channel level, chronic co-incubation greatly increased F508del-CFTR channel activity and temporal stability in most, but not all, cell-free membrane patches. We conclude that chronic lumacaftor and ivacaftor co-treatment restores stability in a small subpopulation of F508del-CFTR Cl - channels but that the majority remain destabilized. A fuller understanding of these effects and the characterization of the small F508del-CFTR subpopulation might be crucial for CF therapy development. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Non-invasive prenatal diagnosis (NIPD) of cystic fibrosis: an optimized protocol using MEMO fluorescent PCR to detect the p.Phe508del mutation.

PubMed

Guissart, C; Dubucs, C; Raynal, C; Girardet, A; Tran Mau Them, F; Debant, V; Rouzier, C; Boureau-Wirth, A; Haquet, E; Puechberty, J; Bieth, E; Dupin Deguine, D; Khau Van Kien, P; Brechard, M P; Pritchard, V; Koenig, M; Claustres, M; Vincent, M C

2017-03-01

Analysis of cell-free foetal DNA (cff-DNA) in maternal plasma is very promising for early diagnosis of monogenic diseases; in particular, cystic fibrosis (CF). However, NIPD of single-gene disorders has been limited by the availability of suitable technical platforms and the need to set up patient or disease-specific custom-made approaches. To make research applications more readily accessible to the clinic, we offer a simple assay combining two independent methods to determine the presence or absence of paternally inherited foetal allele p.Phe508del (the most frequent mutation in CF patients worldwide). The first method detects the presence or absence of a p.Phe508del allele by Mutant Enrichment with 3'-Modified Oligonucleotide PCR coupled to Fragment Length Analysis (MEMO-PCR-FLA). The second method detects the p.Phe508del allele with classical Multiplex Fluorescent PCR including five intragenic and extragenic STR markers of the CFTR locus and a specific SRY sequence. We collected 24 plasma samples from 23 women carrying foetuses at risk for CF and tested each sample using both methods. Our new procedures were successfully applied to 10 couples where fathers carried the p.Phe508del mutation and mothers were carrying a different mutation in the CFTR gene. These simple tests provided clear positive or negative results from the maternal plasma of the pregnant women. We confirmed the presence of cff-DNA in the studied samples by the identification of a tri-allelic DNA profile using a miniSTR kit. All results were correlated with chorionic villus sampling or amniocentesis analyses. This NIPD approach, easily set up in any clinical laboratory where prenatal diagnosis is routinely performed, offers many advantages over current methods: it is simple, rapid, and cost-effective. It opens up the possibility for testing a large number of couples with offspring at risk for CF. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

The cystic fibrosis transmembrane conductance regulator (CFTR) and its stability.

PubMed

Meng, Xin; Clews, Jack; Kargas, Vasileios; Wang, Xiaomeng; Ford, Robert C

2017-01-01

The cystic fibrosis transmembrane conductance regulator (CFTR) is responsible for the disease cystic fibrosis (CF). It is a membrane protein belonging to the ABC transporter family functioning as a chloride/anion channel in epithelial cells around the body. There are over 1500 mutations that have been characterised as CF-causing; the most common of these, accounting for ~70 % of CF cases, is the deletion of a phenylalanine at position 508. This leads to instability of the nascent protein and the modified structure is recognised and then degraded by the ER quality control mechanism. However, even pharmacologically 'rescued' F508del CFTR displays instability at the cell's surface, losing its channel function rapidly and it is rapidly removed from the plasma membrane for lysosomal degradation. This review will, therefore, explore the link between stability and structure/function relationships of membrane proteins and CFTR in particular and how approaches to study CFTR structure depend on its stability. We will also review the application of a fluorescence labelling method for the assessment of the thermostability and the tertiary structure of CFTR.

Cystic fibrosis transmembrane regulator gene (CFTR) is associated with abnormal enamel formation.

PubMed

Arquitt, C K; Boyd, C; Wright, J T

2002-07-01

Cystic fibrosis (CF), a chloride ion transport disorder, is caused by mutations of the cftr gene and is the most common autosomal-recessive heritable disease in Caucasians. CFTR knockout mice have enamel with crystallite defects, retained protein, and hypomineralization, suggesting a role for CFTR in enamel formation and mineralization. This investigation examined CFTR expression and elemental composition in developing murine incisor teeth. RT-PCR showed cftr mRNA expression in the normal mouse apical incisor tissue but not in the CFTR knockout tissue. Elemental analysis by energy-dispersive x-ray spectroscopy showed relatively decreased chloride in secretory-stage CF enamel. Iron and potassium were significantly increased, and calcium was significantly decreased (p value = 0.05) in the CF mature enamel. Abnormal enamel mineralization, ion concentrations, and molecular evidence of cftr mRNA expression by odontogenic cells strongly suggest that CFTR plays an important role in enamel formation.

Effect of ivacaftor in patients with advanced cystic fibrosis and a G551D-CFTR mutation: Safety and efficacy in an expanded access program in the United States.

PubMed

Taylor-Cousar, Jennifer; Niknian, Minoo; Gilmartin, Geoffrey; Pilewski, Joseph M

2016-01-01

Ivacaftor is the first therapeutic agent approved for the treatment of cystic fibrosis (CF) that targets the underlying molecular defect. Patients with severe lung disease were excluded from the randomized Phase 3 trials. This open-label study was designed to provide ivacaftor to patients in critical medical need prior to commercial product availability. CF patients aged ≥6 years with a G551D-CFTR mutation and FEV1 ≤ 40% predicted or listed for lung transplant received ivacaftor 150 mg every 12 h. The primary endpoint was safety as determined by adverse events. Secondary endpoints included assessment of lung function and weight. The rate of serious adverse events was consistent with disease severity. At 24 weeks of treatment with ivacaftor, there was a mean absolute increase in percent predicted FEV1 of 5.5 percentage points and a 3.3 kg mean absolute increase in weight from baseline. In patients with severe lung disease, ivacaftor was well tolerated and was associated with improved lung function and weight gain. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

VX-809 corrects folding defects in cystic fibrosis transmembrane conductance regulator protein through action on membrane-spanning domain 1

PubMed Central

Ren, Hong Yu; Grove, Diane E.; De La Rosa, Oxana; Houck, Scott A.; Sopha, Pattarawut; Van Goor, Fredrick; Hoffman, Beth J.; Cyr, Douglas M.

2013-01-01

Cystic fibrosis (CF) is a fatal genetic disorder associated with defective hydration of lung airways due to the loss of chloride transport through the CF transmembrane conductance regulator protein (CFTR). CFTR contains two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs), and a regulatory domain, and its channel assembly requires multiple interdomain contacts. The most common CF-causing mutation, F508del, occurs in NBD1 and results in misfolding and premature degradation of F508del-CFTR. VX-809 is an investigational CFTR corrector that partially restores CFTR function in people who are homozygous for F508del-CFTR. To identify the folding defect(s) in F508del-CFTR that must be repaired to treat CF, we explored the mechanism of VX-809 action. VX-809 stabilized an N-terminal domain in CFTR that contains only MSD1 and efficaciously restored function to CFTR forms that have missense mutations in MSD1. The action of VX-809 on MSD1 appears to suppress folding defects in F508del-CFTR by enhancing interactions among the NBD1, MSD1, and MSD2 domains. The ability of VX-809 to correct F508del-CFTR is enhanced when combined with mutations that improve F508del-NBD1 interaction with MSD2. These data suggest that the use of VX-809 in combination with an additional CFTR corrector that suppresses folding defects downstream of MSD1 may further enhance CFTR function in people with F508del-CFTR. PMID:23924900

VX-809 corrects folding defects in cystic fibrosis transmembrane conductance regulator protein through action on membrane-spanning domain 1.

PubMed

Ren, Hong Yu; Grove, Diane E; De La Rosa, Oxana; Houck, Scott A; Sopha, Pattarawut; Van Goor, Fredrick; Hoffman, Beth J; Cyr, Douglas M

2013-10-01

Cystic fibrosis (CF) is a fatal genetic disorder associated with defective hydration of lung airways due to the loss of chloride transport through the CF transmembrane conductance regulator protein (CFTR). CFTR contains two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs), and a regulatory domain, and its channel assembly requires multiple interdomain contacts. The most common CF-causing mutation, F508del, occurs in NBD1 and results in misfolding and premature degradation of F508del-CFTR. VX-809 is an investigational CFTR corrector that partially restores CFTR function in people who are homozygous for F508del-CFTR. To identify the folding defect(s) in F508del-CFTR that must be repaired to treat CF, we explored the mechanism of VX-809 action. VX-809 stabilized an N-terminal domain in CFTR that contains only MSD1 and efficaciously restored function to CFTR forms that have missense mutations in MSD1. The action of VX-809 on MSD1 appears to suppress folding defects in F508del-CFTR by enhancing interactions among the NBD1, MSD1, and MSD2 domains. The ability of VX-809 to correct F508del-CFTR is enhanced when combined with mutations that improve F508del-NBD1 interaction with MSD2. These data suggest that the use of VX-809 in combination with an additional CFTR corrector that suppresses folding defects downstream of MSD1 may further enhance CFTR function in people with F508del-CFTR.

Cystic fibrosis chronic rhinosinusitis: A comprehensive review

PubMed Central

Chaaban, Mohamad R.; Kejner, Alexandra; Rowe, Steven M.

2013-01-01

Background: Advances in the care of patients with cystic fibrosis (CF) have improved pulmonary outcomes and survival. In addition, rapid developments regarding the underlying genetic and molecular basis of the disease have led to numerous novel targets for treatment. However, clinical and basic scientific research focusing on therapeutic strategies for CF-associated chronic rhinosinusitis (CRS) lags behind the evidence-based approaches currently used for pulmonary disease. Methods: This review evaluates the available literature and provides an update concerning the pathophysiology, current treatment approaches, and future pharmaceutical tactics in the management of CRS in patients with CF. Results: Optimal medical and surgical strategies for CF CRS are lacking because of a dearth of well-performed clinical trials. Medical and surgical interventions are supported primarily by level 2 or 3 evidence and are aimed at improving clearance of mucus, infection, and inflammation. A number of novel therapeutics that target the basic defect in the cystic fibrosis transmembrane conductance regulator channel are currently under investigation. Ivacaftor, a corrector of the G551D mutation, was recently approved by the Food and Drug Administration. However, sinonasal outcomes using this and other novel drugs are pending. Conclusion: CRS is a lifelong disease in CF patients that can lead to substantial morbidity and decreased quality of life. A multidisciplinary approach will be necessary to develop consistent and evidence-based treatment paradigms. PMID:24119602

Pseudomonas aeruginosa in Cystic Fibrosis Patients With G551D-CFTR Treated With Ivacaftor

PubMed Central

Heltshe, Sonya L.; Mayer-Hamblett, Nicole; Burns, Jane L.; Khan, Umer; Baines, Arthur; Ramsey, Bonnie W.; Rowe, Steven M.

2015-01-01

Background. Ivacaftor improves outcomes in cystic fibrosis (CF) patients with the G551D mutation; however, effects on respiratory microbiology are largely unknown. This study examines changes in CF respiratory pathogens with ivacaftor and correlates them with baseline characteristics and clinical response. Methods. The G551D Observational Study enrolled a longitudinal observational cohort of US patients with CF aged 6 years and older with at least 1 copy of the G551D mutation. Results were linked with retrospective and prospective culture data in the US Cystic Fibrosis Foundation's National Patient Registry. Pseudomonas aeruginosa infection category in the year before and year after ivacaftor was compared and correlated with clinical findings. Results. Among 151 participants prescribed ivacaftor, 29% (26/89) who were culture positive for P. aeruginosa the year prior to ivacaftor use were culture negative the year following treatment; 88% (52/59) of those P. aeruginosa free remained uninfected. The odds of P. aeruginosa positivity in the year after ivacaftor compared with the year prior were reduced by 35% (odds ratio [OR], 0.65; P < .001). Ivacaftor was also associated with reduced odds of mucoid P. aeruginosa (OR, 0.77; P = .013) and Aspergillus (OR, 0.47; P = .039), but not Staphylococcus aureus or other common CF pathogens. Patients with intermittent culture positivity and higher forced expiratory volume in 1 second (FEV1) were most likely to turn culture negative. Reduction in P. aeruginosa was not associated with change in FEV1, body mass index, or hospitalizations. Conclusions. Pseudomonas aeruginosa culture positivity was significantly reduced following ivacaftor treatment. Efficacious CFTR modulation may contribute to lower frequency of culture positivity for P. aeruginosa and other respiratory pathogens, particularly in patients with less established disease. PMID:25425629

Antibiotic exposure and interpersonal variance mask the effect of ivacaftor on respiratory microbiota composition.

PubMed

Peleg, Anton Y; Choo, Jocelyn M; Langan, Katherine M; Edgeworth, Deirdre; Keating, Dominic; Wilson, John; Rogers, Geraint B; Kotsimbos, Tom

2018-01-01

G551D is a class III mutation of the cystic fibrosis transmembrane regulator (CFTR) that results in impaired chloride channel function in cystic fibrosis (CF). Ivacaftor, a CFTR-potentiating agent improves sweat chloride, weight, lung function, and pulmonary exacerbation rate in CF patients with G551D mutations, but its effect on the airway microbiome remains poorly characterised. Twenty CF patients with at least one G551D mutation from a single centre were recruited to a 4month double-blind, placebo-controlled, crossover study of ivacaftor with 28days of active treatment. Sputum microbiota composition was assessed by 16S rRNA gene amplicon sequencing and quantitative PCR at five key time points, along with regular clinical review, respiratory function assessment, and peripheral blood testing. No significant difference in microbiota composition was observed in subjects following ivacaftor treatment or placebo (PERMANOVA P=0.95, square root ECV=-4.94, 9479 permutations). Microbiota composition variance was significantly greater between subjects, than within subjects over time (P<0.0001, Mann Whitney U test), and an additional within-patient paired assessment of microbiota similarity was therefore performed. Again, change in microbiota composition was not significantly greater during treatment with ivacaftor compared to placebo (Wilcoxon test, P=0.51). A significant change in microbiota composition was however associated with any change in antibiotic exposure, regardless of whether ivacaftor or placebo was administered (P=0.006). In a small, subgroup analysis of subjects whose antibiotic exposure did not change within the study period, a significant reduction in total bacterial load was observed during treatment with ivacaftor (P=0.004, two-tailed paired Student's t-test). The short-term impact of ivacaftor therapy on sputum microbiota composition in patients with G551D mutations are modest compared to those resulting from antibiotic exposure, and may be masked by changes in antibiotic treatment regimen. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Cystic Fibrosis Treatment: A Paradigm for New Pediatric Medicines, Globalization of Drug Development and the Role of the European Medicines Agency.

PubMed

Rose, Klaus; Spigarelli, Michael G

2015-03-23

The European Pediatric Pharmaceutical Legislation wants children to benefit more from pharmaceutical progress. In rare diseases, concerns have been raised that this legislation might damage research and stymie drug development. We discuss the role of the European Medicines Agency (EMA) and its Pediatric Committee (PDCO) in the development of ivacaftor, first-in-class for cystic fibrosis (CF) patients with the G551D mutation (and eight other mutations later) and of lumacaftor and ataluren, two more potential break-through CF medications. Ivacaftor was USA-approved early 2012 and six months later in the EU. Registration was based on the same data. We analyzed these drugs' EU pediatric investigation plans (PIPs) and compared the PIP-studies with the pediatric CF studies listed in www.clinicaltrials.gov. The ivacaftor PIP studies appear to reflect what the developer planned anyway, apart from a study in 1-23-month-olds, which has not yet started. The total negotiation time for the current PIP version was approximately 5.5 years. For companies that develop drugs in pediatric diseases, e.g., CF, PIPs represent considerable additional procedural workload with minimal or no additional benefit for the patients. New drugs for pediatric diseases should not be hampered by additional, unnecessary and costly bureaucracy, but be registered as rapidly as possible without compromising safety.

Cystic Fibrosis Treatment: A Paradigm for New Pediatric Medicines, Globalization of Drug Development and the Role of the European Medicines Agency

PubMed Central

Rose, Klaus; Spigarelli, Michael G.

2015-01-01

The European Pediatric Pharmaceutical Legislation wants children to benefit more from pharmaceutical progress. In rare diseases, concerns have been raised that this legislation might damage research and stymie drug development. We discuss the role of the European Medicines Agency (EMA) and its Pediatric Committee (PDCO) in the development of ivacaftor, first-in-class for cystic fibrosis (CF) patients with the G551D mutation (and eight other mutations later) and of lumacaftor and ataluren, two more potential break-through CF medications. Ivacaftor was USA-approved early 2012 and six months later in the EU. Registration was based on the same data. We analyzed these drugs’ EU pediatric investigation plans (PIPs) and compared the PIP-studies with the pediatric CF studies listed in www.clinicaltrials.gov. The ivacaftor PIP studies appear to reflect what the developer planned anyway, apart from a study in 1–23-month-olds, which has not yet started. The total negotiation time for the current PIP version was approximately 5.5 years. For companies that develop drugs in pediatric diseases, e.g., CF, PIPs represent considerable additional procedural workload with minimal or no additional benefit for the patients. New drugs for pediatric diseases should not be hampered by additional, unnecessary and costly bureaucracy, but be registered as rapidly as possible without compromising safety. PMID:27417354

CT-abnormalities, bacteriology and symptoms of sinonasal disease in children with Cystic Fibrosis.

PubMed

Berkhout, M C; Klerx-Melis, F; Fokkens, W J; Nuijsink, M; van Aalderen, W M C; Heijerman, H G M

2016-11-01

Sinonasal pathology in adults with Cystic Fibrosis (CF) is common but the extent of CT-abnormalities and symptoms of sinonasal disease in children with CF and the age of onset are less frequently studied. In this observational, cross-sectional study 58 children with CF from two CF centres were included. All subjects completed a questionnaire regarding sinonasal symptoms, underwent a CT scan of the paranasal sinuses, and in each subject a culture of the upper airways was performed. Subjects were divided in 6 age cohorts (0-2, 3-5, 6-8, 9-11, 12-14 and 15-17years) and were divided into severe and mild CF based on their CFTR mutation. Opacification of the sinonasal system of the subjects was compared with opacification on MRI-scans of an age-matched control group without CF. Most frequently reported symptoms were nasal obstruction and posterior/anterior nasal discharge. Opacification was abundant in every age cohort of the study group and was significantly more compared to the control group. In patients with severe CF the opacification was higher than subjects with mild CF. Upper airway cultures showed predominantly Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa. CT-abnormalities indicating sinonasal disease and symptoms are present from shortly after birth which may argue for a thorough examination of the upper airways in children with CF. Copyright © 2016. Published by Elsevier B.V.

Bone disease in cystic fibrosis: new pathogenic insights opening novel therapies.

PubMed

Jacquot, J; Delion, M; Gangloff, S; Braux, J; Velard, F

2016-04-01

Mutations within the gene encoding for the chloride ion channel cystic fibrosis transmembrane conductance regulator (CFTR) results in cystic fibrosis (CF), the most common lethal autosomal recessive genetic disease that causes a number of long-term health problems, as the bone disease. Osteoporosis and increased vertebral fracture risk associated with CF disease are becoming more important as the life expectancy of patients continues to improve. The etiology of low bone density is multifactorial, most probably a combination of inadequate peak bone mass during puberty and increased bone losses in adults. Body mass index, male sex, advanced pulmonary disease, malnutrition and chronic therapies are established additional risk factors for CF-related bone disease (CFBD). Consistently, recent evidence has confirmed that CFTR plays a major role in the osteoprotegerin (OPG) and COX-2 metabolite prostaglandin E2 (PGE2) production, two key regulators in the bone formation and regeneration. Several others mechanisms were also recognized from animal and cell models contributing to malfunctions of osteoblast (cell that form bone) and indirectly of bone-resorpting osteoclasts. Understanding such mechanisms is crucial for the development of therapies in CFBD. Innovative therapeutic approaches using CFTR modulators such as C18 have recently shown in vitro capacity to enhance PGE2 production and normalized the RANKL-to-OPG ratio in human osteoblasts bearing the mutation F508del-CFTR and therefore potential clinical utility in CFBD. This review focuses on the recently identified pathogenic mechanisms leading to CFBD and potential future therapies for treating CFBD.

Long-Term Evolution of Burkholderia multivorans during a Chronic Cystic Fibrosis Infection Reveals Shifting Forces of Selection

PubMed Central

Silva, Inês N.; Santos, Mário R.; Zlosnik, James E. A.; Speert, David P.; Buskirk, Sean W.; Bruger, Eric L.; Waters, Christopher M.

2016-01-01

ABSTRACT Burkholderia multivorans is an opportunistic pathogen capable of causing severe disease in patients with cystic fibrosis (CF). Patients may be chronically infected for years, during which the bacterial population evolves in response to unknown forces. Here we analyze the genomic and functional evolution of a B. multivorans infection that was sequentially sampled from a CF patient over 20 years. The population diversified into at least four primary, coexisting clades with distinct evolutionary dynamics. The average substitution rate was only 2.4 mutations/year, but notably, some lineages evolved more slowly, whereas one diversified more rapidly by mostly nonsynonymous mutations. Ten loci, mostly involved in gene expression regulation and lipid metabolism, acquired three or more independent mutations and define likely targets of selection. Further, a broad range of phenotypes changed in association with the evolved mutations; they included antimicrobial resistance, biofilm regulation, and the presentation of lipopolysaccharide O-antigen repeats, which was directly caused by evolved mutations. Additionally, early isolates acquired mutations in genes involved in cyclic di-GMP (c-di-GMP) metabolism that associated with increased c-di-GMP intracellular levels. Accordingly, these isolates showed lower motility and increased biofilm formation and adhesion to CFBE41o− epithelial cells than the initial isolate, and each of these phenotypes is an important trait for bacterial persistence. The timing of the emergence of this clade of more adherent genotypes correlated with the period of greatest decline in the patient’s lung function. All together, our observations suggest that selection on B. multivorans populations during long-term colonization of CF patient lungs either directly or indirectly targets adherence, metabolism, and changes in the cell envelope related to adaptation to the biofilm lifestyle. IMPORTANCE Bacteria may become genetically and phenotypically diverse during long-term colonization of cystic fibrosis (CF) patient lungs, yet our understanding of within-host evolutionary processes during these infections is lacking. Here we combined current genome sequencing technologies and detailed phenotypic profiling of the opportunistic pathogen Burkholderia multivorans using sequential isolates sampled from a CF patient over 20 years. The evolutionary history of these isolates highlighted bacterial genes and pathways that were likely subject to strong selection within the host and were associated with altered phenotypes, such as biofilm production, motility, and antimicrobial resistance. Importantly, multiple lineages coexisted for years or even decades within the infection, and the period of diversification within the dominant lineage was associated with deterioration of the patient’s lung function. Identifying traits under strong selection during chronic infection not only sheds new light onto Burkholderia evolution but also sets the stage for tailored therapeutics targeting the prevailing lineages associated with disease progression. PMID:27822534

EG-VEGF, BV8, and their receptor expression in human bronchi and their modification in cystic fibrosis: Impact of CFTR mutation (delF508).

PubMed

Chauvet, Sylvain; Traboulsi, Wael; Thevenon, Laura; Kouadri, Amal; Feige, Jean-Jacques; Camara, Boubou; Alfaidy, Nadia; Benharouga, Mohamed

2015-08-01

Enhanced lung angiogenesis has been reported in cystic fibrosis (CF). Recently, two highly homologous ligands, endocrine gland vascular endothelial growth factor (EG-VEGF) and mammalian Bv8, have been described as new angiogenic factors. Both ligands bind and activate two closely related G protein-coupled receptors, the prokineticin receptor (PROKR) 1 and 2. Yet, the expression, regulation, and potential role of EG-VEGF, BV8, and their receptors in normal and CF lung are still unknown. The expression of the receptors and their ligands was examined using molecular, biochemical, and immunocytochemistry analyses in lungs obtained from CF patients vs. control and in normal and CF bronchial epithelial cells. Cystic fibrosis transmembrane conductance regulator (CFTR) activity was evaluated in relation to both ligands, and concentrations of EG-VEGF were measured by ELISA. At the mRNA level, EG-VEGF, BV8, and PROKR2 gene expression was, respectively, approximately five, four, and two times higher in CF lungs compared with the controls. At the cellular level, both the ligands and their receptors showed elevated expressions in the CF condition. Similar results were observed at the protein level. The EG-VEGF secretion was apical and was approximately two times higher in CF compared with the normal epithelial cells. This secretion was increased following the inhibition of CFTR chloride channel activity. More importantly, EG-VEGF and BV8 increased the intracellular concentration of Ca(2+) and cAMP and stimulated CFTR-chloride channel activity. Altogether, these data suggest local roles for epithelial BV8 and EG-VEGF in the CF airway peribronchial vascular remodeling and highlighted the role of CFTR activity in both ligand biosynthesis and secretion. Copyright © 2015 the American Physiological Society.

New and emerging targeted therapies for cystic fibrosis

PubMed Central

Rowe, Steven M

2016-01-01

Cystic fibrosis (CF) is a monogenic autosomal recessive disorder that affects about 70 000 people worldwide. The clinical manifestations of the disease are caused by defects in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The discovery of the CFTR gene in 1989 has led to a sophisticated understanding of how thousands of mutations in the CFTR gene affect the structure and function of the CFTR protein. Much progress has been made over the past decade with the development of orally bioavailable small molecule drugs that target defective CFTR proteins caused by specific mutations. Furthermore, there is considerable optimism about the prospect of gene replacement or editing therapies to correct all mutations in cystic fibrosis. The recent approvals of ivacaftor and lumacaftor represent the genesis of a new era of precision medicine in the treatment of this condition. These drugs are having a positive impact on the lives of people with cystic fibrosis and are potentially disease modifying. This review provides an update on advances in our understanding of the structure and function of the CFTR, with a focus on state of the art targeted drugs that are in development. PMID:27030675

Sources of Variation in Sweat Chloride Measurements in Cystic Fibrosis.

PubMed

Collaco, Joseph M; Blackman, Scott M; Raraigh, Karen S; Corvol, Harriet; Rommens, Johanna M; Pace, Rhonda G; Boelle, Pierre-Yves; McGready, John; Sosnay, Patrick R; Strug, Lisa J; Knowles, Michael R; Cutting, Garry R

2016-12-01

Expanding the use of cystic fibrosis transmembrane conductance regulator (CFTR) potentiators and correctors for the treatment of cystic fibrosis (CF) requires precise and accurate biomarkers. Sweat chloride concentration provides an in vivo assessment of CFTR function, but it is unknown the degree to which CFTR mutations account for sweat chloride variation. To estimate potential sources of variation for sweat chloride measurements, including demographic factors, testing variability, recording biases, and CFTR genotype itself. A total of 2,639 sweat chloride measurements were obtained in 1,761 twins/siblings from the CF Twin-Sibling Study, French CF Modifier Gene Study, and Canadian Consortium for Genetic Studies. Variance component estimation was performed by nested mixed modeling. Across the tested CF population as a whole, CFTR gene mutations were found to be the primary determinant of sweat chloride variability (56.1% of variation) with contributions from variation over time (e.g., factors related to testing on different days; 13.8%), environmental factors (e.g., climate, family diet; 13.5%), other residual factors (e.g., test variability; 9.9%), and unique individual factors (e.g., modifier genes, unique exposures; 6.8%) (likelihood ratio test, P < 0.001). Twin analysis suggested that modifier genes did not play a significant role because the heritability estimate was negligible (H 2  = 0; 95% confidence interval, 0.0-0.35). For an individual with CF, variation in sweat chloride was primarily caused by variation over time (58.1%) with the remainder attributable to residual/random factors (41.9%). Variation in the CFTR gene is the predominant cause of sweat chloride variation; most of the non-CFTR variation is caused by testing variability and unique environmental factors. If test precision and accuracy can be improved, sweat chloride measurement could be a valuable biomarker for assessing response to therapies directed at mutant CFTR.

Sources of Variation in Sweat Chloride Measurements in Cystic Fibrosis

PubMed Central

Blackman, Scott M.; Raraigh, Karen S.; Corvol, Harriet; Rommens, Johanna M.; Pace, Rhonda G.; Boelle, Pierre-Yves; McGready, John; Sosnay, Patrick R.; Strug, Lisa J.; Knowles, Michael R.; Cutting, Garry R.

2016-01-01

Rationale: Expanding the use of cystic fibrosis transmembrane conductance regulator (CFTR) potentiators and correctors for the treatment of cystic fibrosis (CF) requires precise and accurate biomarkers. Sweat chloride concentration provides an in vivo assessment of CFTR function, but it is unknown the degree to which CFTR mutations account for sweat chloride variation. Objectives: To estimate potential sources of variation for sweat chloride measurements, including demographic factors, testing variability, recording biases, and CFTR genotype itself. Methods: A total of 2,639 sweat chloride measurements were obtained in 1,761 twins/siblings from the CF Twin-Sibling Study, French CF Modifier Gene Study, and Canadian Consortium for Genetic Studies. Variance component estimation was performed by nested mixed modeling. Measurements and Main Results: Across the tested CF population as a whole, CFTR gene mutations were found to be the primary determinant of sweat chloride variability (56.1% of variation) with contributions from variation over time (e.g., factors related to testing on different days; 13.8%), environmental factors (e.g., climate, family diet; 13.5%), other residual factors (e.g., test variability; 9.9%), and unique individual factors (e.g., modifier genes, unique exposures; 6.8%) (likelihood ratio test, P < 0.001). Twin analysis suggested that modifier genes did not play a significant role because the heritability estimate was negligible (H2 = 0; 95% confidence interval, 0.0–0.35). For an individual with CF, variation in sweat chloride was primarily caused by variation over time (58.1%) with the remainder attributable to residual/random factors (41.9%). Conclusions: Variation in the CFTR gene is the predominant cause of sweat chloride variation; most of the non-CFTR variation is caused by testing variability and unique environmental factors. If test precision and accuracy can be improved, sweat chloride measurement could be a valuable biomarker for assessing response to therapies directed at mutant CFTR. PMID:27258095

Detection of CFTR function and modulation in primary human nasal cell spheroids.

PubMed

Brewington, John J; Filbrandt, Erin T; LaRosa, F J; Ostmann, Alicia J; Strecker, Lauren M; Szczesniak, Rhonda D; Clancy, John P

2018-01-01

Expansion of CFTR modulators to patients with rare/undescribed mutations will be facilitated by patient-derived models quantifying CFTR function and restoration. We aimed to generate a personalized model system of CFTR function and modulation using non-surgically obtained nasal epithelial cells (NECs). NECs obtained by curettage from healthy volunteers and CF patients were expanded and grown in 3-dimensional culture as spheroids, characterized, and stimulated with cAMP-inducing agents to activate CFTR. Spheroid swelling was quantified as a proxy for CFTR function. NEC spheroids recapitulated characteristics of pseudostratified respiratory epithelia. When stimulated with forskolin/IBMX, spheroids swelled in the presence of functional CFTR, and shrank in its absence. Spheroid swelling quantified mutant CFTR restoration in F508del homozygous cells using clinically available CFTR modulators. NEC spheroids hold promise for understanding rare CFTR mutations and personalized modulator testing to drive evaluation for CF patients with common, rare or undescribed mutations. Portions of this data have previously been presented in abstract form at the 2016 meetings of the American Thoracic Society and the 2016 North American Cystic Fibrosis Conference. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

What's it Like to Have Cystic Fibrosis?

MedlinePlus

... deal with cystic fibrosis. What Is CF? Cystic fibrosis (CF) is a disease that causes the body to make thick, sticky mucus (say: ... special protein. This protein is defective in cystic fibrosis, producing the thick, sticky mucus that causes problems for people with CF. What Causes CF? ...

CFTR Modulators: Shedding Light on Precision Medicine for Cystic Fibrosis

PubMed Central

Lopes-Pacheco, Miquéias

2016-01-01

Cystic fibrosis (CF) is the most common life-threatening monogenic disease afflicting Caucasian people. It affects the respiratory, gastrointestinal, glandular and reproductive systems. The major cause of morbidity and mortality in CF is the respiratory disorder caused by a vicious cycle of obstruction of the airways, inflammation and infection that leads to epithelial damage, tissue remodeling and end-stage lung disease. Over the past decades, life expectancy of CF patients has increased due to early diagnosis and improved treatments; however, these patients still present limited quality of life. Many attempts have been made to rescue CF transmembrane conductance regulator (CFTR) expression, function and stability, thereby overcoming the molecular basis of CF. Gene and protein variances caused by CFTR mutants lead to different CF phenotypes, which then require different treatments to quell the patients’ debilitating symptoms. In order to seek better approaches to treat CF patients and maximize therapeutic effects, CFTR mutants have been stratified into six groups (although several of these mutations present pleiotropic defects). The research with CFTR modulators (read-through agents, correctors, potentiators, stabilizers and amplifiers) has achieved remarkable progress, and these drugs are translating into pharmaceuticals and personalized treatments for CF patients. This review summarizes the main molecular and clinical features of CF, emphasizes the latest clinical trials using CFTR modulators, sheds light on the molecular mechanisms underlying these new and emerging treatments, and discusses the major breakthroughs and challenges to treating all CF patients. PMID:27656143

The Sweat Metabolome of Screen-Positive Cystic Fibrosis Infants: Revealing Mechanisms beyond Impaired Chloride Transport

PubMed Central

2017-01-01

The sweat chloride test remains the gold standard for confirmatory diagnosis of cystic fibrosis (CF) in support of universal newborn screening programs. However, it provides ambiguous results for intermediate sweat chloride cases while not reflecting disease progression when classifying the complex CF disease spectrum given the pleiotropic effects of gene modifiers and environment. Herein we report the first characterization of the sweat metabolome from screen-positive CF infants and identify metabolites associated with disease status that complement sweat chloride testing. Pilocarpine-stimulated sweat specimens were collected independently from two CF clinics, including 50 unaffected infants (e.g., carriers) and 18 confirmed CF cases. Nontargeted metabolite profiling was performed using multisegment injection–capillary electrophoresis–mass spectrometry as a high throughput platform for analysis of polar/ionic metabolites in volume-restricted sweat samples. Amino acids, organic acids, amino acid derivatives, dipeptides, purine derivatives, and unknown exogenous compounds were identified in sweat when using high resolution tandem mass spectrometry, including metabolites associated with affected yet asymptomatic CF infants, such as asparagine and glutamine. Unexpectedly, a metabolite of pilocarpine, used to stimulate sweat secretion, pilocarpic acid, and a plasticizer metabolite from environmental exposure, mono(2-ethylhexyl)phthalic acid, were secreted in the sweat of CF infants at significantly lower concentrations relative to unaffected CF screen-positive controls. These results indicated a deficiency in human paraoxonase, an enzyme unrelated to mutations to the cystic fibrosis transmembrane conductance regulator (CFTR) and impaired chloride transport, which is a nonspecific arylesterase/lactonase known to mediate inflammation, bacterial biofilm formation, and recurrent lung infections in affected CF children later in life. This work sheds new light into the underlying mechanisms of CF pathophysiology as required for new advances in precision medicine of orphan diseases that benefit from early detection and intervention, including new molecular targets for therapeutic intervention. PMID:28852705

The Sweat Metabolome of Screen-Positive Cystic Fibrosis Infants: Revealing Mechanisms beyond Impaired Chloride Transport.

PubMed

Macedo, Adriana N; Mathiaparanam, Stellena; Brick, Lauren; Keenan, Katherine; Gonska, Tanja; Pedder, Linda; Hill, Stephen; Britz-McKibbin, Philip

2017-08-23

The sweat chloride test remains the gold standard for confirmatory diagnosis of cystic fibrosis (CF) in support of universal newborn screening programs. However, it provides ambiguous results for intermediate sweat chloride cases while not reflecting disease progression when classifying the complex CF disease spectrum given the pleiotropic effects of gene modifiers and environment. Herein we report the first characterization of the sweat metabolome from screen-positive CF infants and identify metabolites associated with disease status that complement sweat chloride testing. Pilocarpine-stimulated sweat specimens were collected independently from two CF clinics, including 50 unaffected infants (e.g., carriers) and 18 confirmed CF cases. Nontargeted metabolite profiling was performed using multisegment injection-capillary electrophoresis-mass spectrometry as a high throughput platform for analysis of polar/ionic metabolites in volume-restricted sweat samples. Amino acids, organic acids, amino acid derivatives, dipeptides, purine derivatives, and unknown exogenous compounds were identified in sweat when using high resolution tandem mass spectrometry, including metabolites associated with affected yet asymptomatic CF infants, such as asparagine and glutamine. Unexpectedly, a metabolite of pilocarpine, used to stimulate sweat secretion, pilocarpic acid, and a plasticizer metabolite from environmental exposure, mono(2-ethylhexyl)phthalic acid, were secreted in the sweat of CF infants at significantly lower concentrations relative to unaffected CF screen-positive controls. These results indicated a deficiency in human paraoxonase, an enzyme unrelated to mutations to the cystic fibrosis transmembrane conductance regulator (CFTR) and impaired chloride transport, which is a nonspecific arylesterase/lactonase known to mediate inflammation, bacterial biofilm formation, and recurrent lung infections in affected CF children later in life. This work sheds new light into the underlying mechanisms of CF pathophysiology as required for new advances in precision medicine of orphan diseases that benefit from early detection and intervention, including new molecular targets for therapeutic intervention.

Cystic fibrosis gene therapy: a mutation-independent treatment.

PubMed

Griesenbach, Uta; Davies, Jane C; Alton, Eric

2016-11-01

Since cloning of the disease-causing gene 27 years ago, the development of cystic fibrosis (CF) gene therapy has been pursued. Here, we will summarize key findings with a particular focus on recent developments. Almost 3 decades of research have highlighted the complexity of lung gene transfer and have generated a body of data that has recently led to the completion of a large phase IIB study. This trial has, for the first time, shown that nonviral gene transfer can, albeit modestly, stabilize lung function in CF and provides the impetus for further development of more potent gene transfer agents. Lentiviral vectors, specifically pseudotyped to enable entry into airway epithelial cells have most recently been developed. Persistent expression after a single dose and the ability to be administered repeatedly suggest that these viral vectors hold promise for the treatment of CF; a first-in-man clinical trial will shortly be initiated. Although the development of CF gene therapy has been slower than initially anticipated, recent progress has been encouraging and has renewed the interest of academics and industry to pursue lung gene therapy.

Cirrhosis could be associated with severe mutations of the cystic fibrosis gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lenaerts, C.; Piussan, C.; Soto, B.

1994-09-01

Previous studies failed to demonstrate a genetic predisposition to liver disease in cystic fibrosis. In order to characterize patients with cirrhosis defined on the basis of either hepatosplenomegaly, portal hypertension or liver biopsy, we analyzed a total number of 110 cirrhotic CF patients from different CF centers in France. Of them, 71 are males, which is not different from the overall CF french population. All but 2 are pancreatic insufficient. A history of meconium ileus {plus_minus} meconium ileus equivalent seems to be a risk factor for cirrhosis since these complications are present in 29% of the cirrhotic patients vs. 19%more » in the non-cirrhotic population (p = 0.03). This confirms our previous data in a postmortem study. Genotype analysis was performed in all the patients. {Delta}F508 represents 70% of the identified mutations with a higher proportion of {Delta}F508 +/+ in the cirrhotic than in the non-cirrhotic population (52% vs. 42%, p=0.003), 35% {Delta}F508 +/- vs. 42% and 13% {Delta}F508 -/- vs. 16%. Sixty percent of the other mutations associated with cirrhosis are identified, usually in {Delta}F508 +/- and include 1303 N-K, 542 G-X, 1078 del T, 1282 W-X, 1313 Q-X, 827 E-X, 1061 G-R, 1301 N-H, 14 K-X, 1717-1 G-A, 1918 delGC, 2183 A-G, 2184 delA, 405+1 G-A, 507 {Delta}l, 574 delA, 621+1 G-T, 85 G-E and 1303 N-K/other, 227 L-R/other. None of the cirrhotic patients bear one of the dominant missense mutations regarded as mild with respect to pancreatic function (117 R-H, 334 R-W, 347 R-P, 455 A-E, 574 P-H) or both the {Delta}F508 and the 5512 G-A mutations associated with a decreased risk of meconium ileus. Cirrhosis could thus be linked to the presence of 2 of the severe mutations of the CF gene associated with pancreatic insufficiency.« less

Epistatic selection of a sequence 5{prime} of the gene responsible for cystic fibrosis may account for the high frequency of this disease in the Caucasian population

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macek, M. Jr.; Nash, E.; Cutting, G.R.

1994-09-01

Cystic fibrosis (CF) is one of the more common lethal autosomal recessive disorders in Caucasian populations. Numerous hypotheses including genetic drift, founder effect, sex ratio, segregation distortions and various forms of heterozygote advantage have been proposed to explain the relatively high frequency of CF alleles. The observation of high linkage disequilibrium between markers at the 5{prime} end of CFTR and mutations that cause CF raised the possibility of epistatic selection. CF-linked marker allele frequencies were determined in 417 elderly individuals from a stable Czech population that survived high levels of infant and childhood mortality in the pre-antibiotic era. These datamore » were compared with allele frequencies of 646 contemporary newborns and 345 young adults drawn from the same population who had significantly lower mortality rates in the antibiotic era. Allele frequencies of markers CS7/Hhal and KM19/Pstl from the D7S23 locus are significantly different (p<0.05) between elderly female and male subjects in this population. Furthermore, there is a significant difference in the allele frequencies of marker CS7/Hhal when newborn females and elderly women are compared (p<0.05). Taken together, these data suggest that the allele status at the CS7 region influenced female survival in the period of high infant and childhood mortality in the pre-antibiotic era. Under this selective pressure, CFTR mutations that occurred on the {open_quotes}favorable{close_quotes} background would marginally increase in frequency in each successive generation and more ancient mutations residing on this background would become the most frequent in the general population.« less

Impact of the CFTR-potentiator ivacaftor on airway microbiota in cystic fibrosis patients carrying a G551D mutation.

PubMed

Bernarde, Cédric; Keravec, Marlène; Mounier, Jérôme; Gouriou, Stéphanie; Rault, Gilles; Férec, Claude; Barbier, Georges; Héry-Arnaud, Geneviève

2015-01-01

Airway microbiota composition has been clearly correlated with many pulmonary diseases, and notably with cystic fibrosis (CF), an autosomal genetic disorder caused by mutation in the CF transmembrane conductance regulator (CFTR). Recently, a new molecule, ivacaftor, has been shown to re-establish the functionality of the G551D-mutated CFTR, allowing significant improvement in lung function. The purpose of this study was to follow the evolution of the airway microbiota in CF patients treated with ivacaftor, using quantitative PCR and pyrosequencing of 16S rRNA amplicons, in order to identify quantitative and qualitative changes in bacterial communities. Three G551D children were followed up longitudinally over a mean period of more than one year covering several months before and after initiation of ivacaftor treatment. 129 operational taxonomy units (OTUs), representing 64 genera, were identified. There was no significant difference in total bacterial load before and after treatment. Comparison of global community composition found no significant changes in microbiota. Two OTUs, however, showed contrasting dynamics: after initiation of ivacaftor, the relative abundance of the anaerobe Porphyromonas 1 increased (p<0.01) and that of Streptococcus 1 (S. mitis group) decreased (p<0.05), possibly in relation to the anti-Gram-positive properties of ivacaftor. The anaerobe Prevotella 2 correlated positively with the pulmonary function test FEV-1 (r=0.73, p<0.05). The study confirmed the presumed positive role of anaerobes in lung function. Several airway microbiota components, notably anaerobes (obligate or facultative anaerobes), could be valuable biomarkers of lung function improvement under ivacaftor, and could shed light on the pathophysiology of lung disease in CF patients.

Trends in Bone Mineral Density in Young Adults with Cystic Fibrosis over a 15 Year Period

PubMed Central

Putman, Melissa S.; Baker, Joshua F.; Uluer, Ahmet; Herlyn, Karen; Lapey, Allen; Sicilian, Leonard; Tillotson, Angela Pizzo; Gordon, Catherine M.; Merkel, Peter A.; Finkelstein, Joel S.

2015-01-01

Background Improvements in clinical care have led to increased life expectancy in patients with cystic fibrosis (CF) over the past several decades. Whether these improvements have had significant effects on bone health in patients with CF is unclear. Methods This is a cross-sectional study comparing clinical characteristics and bone mineral density (BMD) measured by dual energy X-ray absorptiometry (DXA) in adults with CF evaluated in 1995–1999 to age-, race-, and gender matched patients with CF evaluated in 2011–2013 at the same center on calibrated DXA machines. Results The cohorts were similar in terms of age, BMI, pancreatic insufficiency, presence of F508del mutation, and reproductive history. In the most recent cohort, pulmonary function was superior, and fewer patients had vitamin D deficiency or secondary hyperparathyroidism. Areal BMD measures of the PA spine, lateral spine, and distal radius were similarly low in the two cohorts. Conclusions Although pulmonary function and vitamin D status were better in patients in the present-day cohort, areal BMD of the spine was reduced in a significant number of patients and was no different in patients with CF today than in the late 1990s. Further attention to optimizing bone health may be necessary to prevent CF-related bone disease. PMID:25698451

CORK Study in Cystic Fibrosis: Sustained Improvements in Ultra-Low-Dose Chest CT Scores After CFTR Modulation With Ivacaftor.

PubMed

Ronan, Nicola J; Einarsson, Gisli G; Twomey, Maria; Mooney, Denver; Mullane, David; NiChroinin, Muireann; O'Callaghan, Grace; Shanahan, Fergus; Murphy, Desmond M; O'Connor, Owen J; Shortt, Cathy A; Tunney, Michael M; Eustace, Joseph A; Maher, Michael M; Elborn, J Stuart; Plant, Barry J

2018-02-01

Ivacaftor produces significant clinical benefit in patients with cystic fibrosis (CF) with the G551D mutation. Prevalence of this mutation at the Cork CF Centre is 23%. This study assessed the impact of cystic fibrosis transmembrane conductance regulator modulation on multiple modalities of patient assessment. Thirty-three patients with the G551D mutation were assessed at baseline and prospectively every 3 months for 1 year after initiation of ivacaftor. Change in ultra-low-dose chest CT scans, blood inflammatory mediators, and the sputum microbiome were assessed. Significant improvements in FEV 1 , BMI, and sweat chloride levels were observed post-ivacaftor treatment. Improvement in ultra-low-dose CT imaging scores were observed after treatment, with significant mean reductions in total Bhalla score (P < .01), peribronchial thickening (P = .035), and extent of mucous plugging (P < .001). Reductions in circulating inflammatory markers, including interleukin (IL)-1β, IL-6, and IL-8 were demonstrated. There was a 30% reduction in the relative abundance of Pseudomonas species and an increase in the relative abundance of bacteria associated with more stable community structures. Posttreatment community richness increased significantly (P = .03). Early and sustained improvements on ultra-low-dose CT scores suggest it may be a useful method of evaluating treatment response. It paralleled improvement in symptoms, circulating inflammatory markers, and changes in the lung microbiota. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Increased folding and channel activity of a rare cystic fibrosis mutant with CFTR modulators

PubMed Central

Grove, Diane E.; Houck, Scott A.

2011-01-01

Cystic fibrosis (CF) is a lethal recessive genetic disease caused by mutations in the CFTR gene. The gene product is a PKA-regulated anion channel that is important for fluid and electrolyte transport in the epithelia of lung, gut, and ducts of the pancreas and sweat glands. The most common CFTR mutation, ΔF508, causes a severe, but correctable, folding defect and gating abnormality, resulting in negligible CFTR function and disease. There are also a large number of rare CF-related mutations where disease is caused by CFTR misfolding. Yet the extent to which defective biogenesis of these CFTR mutants can be corrected is not clear. CFTRV232D is one such mutant that exhibits defective folding and trafficking. CFTRΔF508 misfolding is difficult to correct, but defective biogenesis of CFTRV232D is corrected to near wild-type levels by small-molecule folding correctors in development as CF therapeutics. To determine if CFTRV232D protein is competent as a Cl− channel, we utilized single-channel recordings from transfected human embryonic kidney (HEK-293) cells. After PKA stimulation, CFTRV232D channels were detected in patches with a unitary Cl− conductance indistinguishable from that of CFTR. Yet the frequency of detecting CFTRV232D channels was reduced to ∼20% of patches compared with 60% for CFTR. The folding corrector Corr-4a increased the CFTRV232D channel detection rate and activity to levels similar to CFTR. CFTRV232D-corrected channels were inhibited with CFTRinh-172 and stimulated fourfold by the CFTR channel potentiator VRT-532. These data suggest that CF patients with rare mutations that cause CFTR misfolding, such as CFTRV232D, may benefit from treatment with folding correctors and channel potentiators in development to restore CFTRΔF508 function. PMID:21642448

Chronic Rhinosinusitis in Patients with Cystic Fibrosis.

PubMed

Hamilos, Daniel L

2016-01-01

Chronic rhinosinusitis (CRS) is highly prevalent in patients with cystic fibrosis (CF) and accounts for significant morbidity and contribution to CF lung disease. Mutations of the cystic fibrosis transmembrane regulator gene occur with increased prevalence in patients with CRS without CF, suggesting some contribution to CRS pathophysiology. Nasal polyps (NPs) occur with increased prevalence in patients with CF of all ages and have a more neutrophilic appearance with fewer eosinophils and increased submucosal glandular elements in comparison to NPs from patients without CF. Mainstays of medical treatment include isotonic saline irrigations and topical intranasal glucocorticoids, with some evidence that topical intranasal glucocorticoids reduce NP size. Although inhaled hypertonic saline (7%) has been widely studied as a mucolytic agent for CF lung disease, there are no reports of its use in CF CRS. Mucolytics have also not been studied as a treatment for CRS in CF, and most evidence does not support their use for CF lung disease. Nasally nebulized dornase alfa (recombinant human deoxyribonuclease) following sinus surgery shows promise for treatment. Other unproven therapies include addition of baby shampoo to isotonic saline to potentially thin mucus and help prevent biofilm formation. There are no data to support the use of low-dose oral macrolide antibiotics or the use of prophylactic oral antibiotics for CRS in patients with CF. However, there is some support for the use of topical antibiotics, including colistimethate sodium or tobramycin, administered as a sinus irrigation or antral lavage in patients following sinus surgery when susceptible bacteria are cultured. Key components of CF sinus surgical management include extensive surgery to ensure that the maxillary, frontal, sphenoid, and ethmoid sinuses are all widely opened with smoothing of bony overhangs to prevent mucus retention and bacterial recolonization, postoperative meticulous daily nasal irrigations, and appropriate use of culture-directed topical antibiotics. There are no data yet on whether CF-targeted therapies, including ivacaftor or ivacaftor combined with lumacaftor, have an impact on CF CRS. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Restoration of CFTR function in patients with cystic fibrosis carrying the F508del-CFTR mutation

PubMed Central

Stefano, Daniela De; Villella, Valeria R; Esposito, Speranza; Tosco, Antonella; Sepe, Angela; Gregorio, Fabiola De; Salvadori, Laura; Grassia, Rosa; Leone, Carlo A; Rosa, Giuseppe De; Maiuri, Maria C; Pettoello-Mantovani, Massimo; Guido, Stefano; Bossi, Anna; Zolin, Anna; Venerando, Andrea; Pinna, Lorenzo A; Mehta, Anil; Bona, Gianni; Kroemer, Guido; Maiuri, Luigi; Raia, Valeria

2014-01-01

Restoration of BECN1/Beclin 1-dependent autophagy and depletion of SQSTM1/p62 by genetic manipulation or autophagy-stimulatory proteostasis regulators, such as cystamine, have positive effects on mouse models of human cystic fibrosis (CF). These measures rescue the functional expression of the most frequent pathogenic CFTR mutant, F508del, at the respiratory epithelial surface and reduce lung inflammation in CftrF508del homozygous mice. Cysteamine, the reduced form of cystamine, is an FDA-approved drug. Here, we report that oral treatment with cysteamine greatly reduces the mortality rate and improves the phenotype of newborn mice bearing the F508del-CFTR mutation. Cysteamine was also able to increase the plasma membrane expression of the F508del-CFTR protein in nasal epithelial cells from F508del homozygous CF patients, and these effects persisted for 24 h after cysteamine withdrawal. Importantly, this cysteamine effect after washout was further sustained by the sequential administration of epigallocatechin gallate (EGCG), a green tea flavonoid, both in vivo, in mice, and in vitro, in primary epithelial cells from CF patients. In a pilot clinical trial involving 10 F508del-CFTR homozygous CF patients, the combination of cysteamine and EGCG restored BECN1, reduced SQSTM1 levels and improved CFTR function from nasal epithelial cells in vivo, correlating with a decrease of chloride concentrations in sweat, as well as with a reduction of the abundance of TNF/TNF-alpha (tumor necrosis factor) and CXCL8 (chemokine [C-X-C motif] ligand 8) transcripts in nasal brushing and TNF and CXCL8 protein levels in the sputum. Altogether, these results suggest that optimal schedules of cysteamine plus EGCG might be used for the treatment of CF caused by the F508del-CFTR mutation. PMID:25350163

Nuclease-mediated double-strand break (DSB) enhancement of small fragment homologous recombination (SFHR) gene modification in human-induced pluripotent stem cells (hiPSCs).

PubMed

Sargent, R Geoffrey; Suzuki, Shingo; Gruenert, Dieter C

2014-01-01

Recent developments in methods to specifically modify genomic DNA using sequence-specific endonucleases and donor DNA have opened the door to a new therapeutic paradigm for cell and gene therapy of inherited diseases. Sequence-specific endonucleases, in particular transcription activator-like (TAL) effector nucleases (TALENs), have been coupled with polynucleotide small/short DNA fragments (SDFs) to correct the most common mutation in the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene, a 3-base-pair deletion at codon 508 (delF508), in induced pluripotent stem (iPS) cells. The studies presented here describe the generation of candidate TALENs and their co-transfection with wild-type (wt) CFTR-SDFs into CF-iPS cells homozygous for the delF508 mutation. Using an allele-specific PCR (AS-PCR)-based cyclic enrichment protocol, clonal populations of corrected CF-iPS cells were isolated and expanded.

Assessing the improvements in the newborn screening strategy for cystic fibrosis in the Balearic Islands.

PubMed

Bauça, Josep Miquel; Morell-Garcia, Daniel; Vila, Magdalena; Pérez, Gerardo; Heine-Suñer, Damián; Figuerola, Joan

2015-04-01

Newborn screening strategies for cystic fibrosis (CF) are run worldwide, and aim at the early detection of the disorder to significantly improve the quality of life. Elevated levels of immunoreactive trypsinogen (IRT) represent a high likelihood for the screened child to be affected with CF. However, the specificity of IRT is low. The objective of this study was to assess the screening program in the Balearic Islands during the past 14 years. We evaluated all results of the screening program after 14 years, by considering all changes in the protocol and assessing the number of positive samples, the mutations detected, the number of sweat tests performed, the incidence of CF and the presence of false-negative cases. Despite a great variability among the different Balearic Islands, the global incidence of CF was 1:6059 for the 14 years assessed. The incidence in the smaller islands is about 5 times higher than in Majorca (1:2376 versus 1:10,613). After different changes in the protocol, an IRT cut-off value of 60 ng/mL was established. The two most common mutations are ΔF508 and G542X, in accordance with other geographical regions. The changes in the protocol helped reduce the number of sweat tests performed without any increase in the false-negative rate. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Correction of the F508del-CFTR protein processing defect in vitro by the investigational drug VX-809

PubMed Central

Van Goor, Fredrick; Hadida, Sabine; Grootenhuis, Peter D. J.; Burton, Bill; Stack, Jeffrey H.; Straley, Kimberly S.; Decker, Caroline J.; Miller, Mark; McCartney, Jason; Olson, Eric R.; Wine, Jeffrey J.; Frizzell, Ray A.; Ashlock, Melissa; Negulescu, Paul A.

2011-01-01

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene that impair the function of CFTR, an epithelial chloride channel required for proper function of the lung, pancreas, and other organs. Most patients with CF carry the F508del CFTR mutation, which causes defective CFTR protein folding and processing in the endoplasmic reticulum, resulting in minimal amounts of CFTR at the cell surface. One strategy to treat these patients is to correct the processing of F508del-CFTR with small molecules. Here we describe the in vitro pharmacology of VX-809, a CFTR corrector that was advanced into clinical development for the treatment of CF. In cultured human bronchial epithelial cells isolated from patients with CF homozygous for F508del, VX-809 improved F508del-CFTR processing in the endoplasmic reticulum and enhanced chloride secretion to approximately 14% of non-CF human bronchial epithelial cells (EC50, 81 ± 19 nM), a level associated with mild CF in patients with less disruptive CFTR mutations. F508del-CFTR corrected by VX-809 exhibited biochemical and functional characteristics similar to normal CFTR, including biochemical susceptibility to proteolysis, residence time in the plasma membrane, and single-channel open probability. VX-809 was more efficacious and selective for CFTR than previously reported CFTR correctors. VX-809 represents a class of CFTR corrector that specifically addresses the underlying processing defect in F508del-CFTR. PMID:21976485

Some gating potentiators, including VX-770, diminish ΔF508-CFTR functional expression

PubMed Central

Veit, Guido; Avramescu, Radu G.; Perdomo, Doranda; Phuan, Puay-Wah; Bagdany, Miklos; Apaja, Pirjo M.; Borot, Florence; Szollosi, Daniel; Wu, Yu-Sheng; Finkbeiner, Walter E.; Hegedus, Tamas; Verkman, Alan S.; Lukacs, Gergely L.

2015-01-01

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane regulator (CFTR) that result in reduced anion conductance at the apical membrane of secretory epithelia. Treatment of CF patients carrying the G551D gating mutation with the potentiator VX-770 (ivacaftor) largely restores channel activity and has shown substantial clinical benefit. However, most CF patients carry the ΔF508 mutation, which impairs CFTR folding, processing, function, and stability. Studies in homozygous ΔF508 CF patients indicated little clinical benefit of monotherapy with the investigational corrector VX-809 (lumacaftor) or VX-770, whereas combination clinical trials show limited but significant improvements in lung function. We show that VX-770, as well as most other potentiators, reduces the correction efficacy of VX-809 and another investigational corrector, VX-661. To mimic the administration of VX-770 alone or in combination with VX-809, we examined its long-term effect in immortalized and primary human respiratory epithelia. VX-770 diminished the folding efficiency and the metabolic stability of ΔF508-CFTR at the endoplasmic reticulum (ER) and post-ER compartments, respectively, causing reduced cell surface ΔF508-CFTR density and function. VX-770–induced destabilization of ΔF508-CFTR was influenced by second-site suppressor mutations of the folding defect and was prevented by stabilization of the nucleotide-binding domain 1 (NBD1)–NBD2 interface. The reduced correction efficiency of ΔF508-CFTR, as well as of two other processing mutations in the presence of VX-770, suggests the need for further optimization of potentiators to maximize the clinical benefit of corrector-potentiator combination therapy in CF. PMID:25101887

Some gating potentiators, including VX-770, diminish ΔF508-CFTR functional expression.

PubMed

Veit, Guido; Avramescu, Radu G; Perdomo, Doranda; Phuan, Puay-Wah; Bagdany, Miklos; Apaja, Pirjo M; Borot, Florence; Szollosi, Daniel; Wu, Yu-Sheng; Finkbeiner, Walter E; Hegedus, Tamas; Verkman, Alan S; Lukacs, Gergely L

2014-07-23

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane regulator (CFTR) that result in reduced anion conductance at the apical membrane of secretory epithelia. Treatment of CF patients carrying the G551D gating mutation with the potentiator VX-770 (ivacaftor) largely restores channel activity and has shown substantial clinical benefit. However, most CF patients carry the ΔF508 mutation, which impairs CFTR folding, processing, function, and stability. Studies in homozygous ΔF508 CF patients indicated little clinical benefit of monotherapy with the investigational corrector VX-809 (lumacaftor) or VX-770, whereas combination clinical trials show limited but significant improvements in lung function. We show that VX-770, as well as most other potentiators, reduces the correction efficacy of VX-809 and another investigational corrector, VX-661. To mimic the administration of VX-770 alone or in combination with VX-809, we examined its long-term effect in immortalized and primary human respiratory epithelia. VX-770 diminished the folding efficiency and the metabolic stability of ΔF508-CFTR at the endoplasmic reticulum (ER) and post-ER compartments, respectively, causing reduced cell surface ΔF508-CFTR density and function. VX-770-induced destabilization of ΔF508-CFTR was influenced by second-site suppressor mutations of the folding defect and was prevented by stabilization of the nucleotide-binding domain 1 (NBD1)-NBD2 interface. The reduced correction efficiency of ΔF508-CFTR, as well as of two other processing mutations in the presence of VX-770, suggests the need for further optimization of potentiators to maximize the clinical benefit of corrector-potentiator combination therapy in CF. Copyright © 2014, American Association for the Advancement of Science.

Cystic Fibrosis (CF) Respiratory Screen: Sputum

MedlinePlus

... for Educators Search English Español Cystic Fibrosis (CF) Respiratory Screen: Sputum KidsHealth / For Parents / Cystic Fibrosis (CF) Respiratory Screen: Sputum What's in this article? What It ...

Potentiator Ivacaftor Abrogates Pharmacological Correction of ΔF508 CFTR in Cystic Fibrosis

PubMed Central

Cholon, Deborah M.; Quinney, Nancy L.; Fulcher, M. Leslie; Esther, Charles R.; Das, Jhuma; Dokholyan, Nikolay V.; Randell, Scott H.; Boucher, Richard C.; Gentzsch, Martina

2014-01-01

Cystic Fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR). Newly developed “correctors” such as lumacaftor (VX-809) that improve CFTR maturation and trafficking and “potentiators” such as ivacaftor (VX-770) that enhance channel activity may provide important advances in CF therapy. Although VX-770 has demonstrated substantial clinical efficacy in the small subset of patients with a mutation (G551D) that affects only channel activity, a single compound is not sufficient to treat patients with the more common CFTR mutation, ΔF508. Thus, patients with ΔF508 will likely require treatment with both correctors and potentiators to achieve clinical benefit. However, whereas the effectiveness of acute treatment with this drug combination has been demonstrated in vitro, the impact of chronic therapy has not been established. In studies of human primary airway epithelial cells, we found that both acute and chronic treatment with VX-770 improved CFTR function in cells with the G551D mutation, consistent with clinical studies. In contrast, chronic VX-770 administration caused a dose-dependent reversal of VX-809-mediated CFTR correction in ΔF508 homozygous cultures. This result reflected the destabilization of corrected ΔF508 CFTR by VX-770, dramatically increasing its turnover rate. Chronic VX-770 treatment also reduced mature wild-type CFTR levels and function. These findings demonstrate that chronic treatment with CFTR potentiators and correctors may have unexpected effects that cannot be predicted from short-term studies. Combining of these drugs to maximize rescue of ΔF508 CFTR may require changes in dosing and/or development of new potentiator compounds that do not interfere with CFTR stability. PMID:25101886

Ivacaftor and symptoms of extra-oesophageal reflux in patients with cystic fibrosis and G551D mutation.

PubMed

Zeybel, Gemma L; Pearson, Jeffrey P; Krishnan, Amaran; Bourke, Stephen J; Doe, Simon; Anderson, Alan; Faruqi, Shoaib; Morice, Alyn H; Jones, Rhys; McDonnell, Melissa; Zeybel, Mujdat; Dettmar, Peter W; Brodlie, Malcolm; Ward, Chris

2017-01-01

Extra-oesophageal reflux (EOR) may lead to microaspiration in patients with cystic fibrosis (CF), a probable cause of deteriorating lung function. Successful clinical trials of ivacaftor highlight opportunities to understand EOR in a real world study. Data from 12 patients with CF and the G551D mutation prescribed ivacaftor (150mg bd) was collected at baseline, 6, 26 and 52weeks. The changes in symptoms of EOR were assessed by questionnaire (reflux symptom index (RSI) and Hull airway reflux questionnaire (HARQ)). Six patients presented EOR at baseline (RSI >13; median 13; range 2-29) and 5 presented airway reflux (HARQ >13; median 12; range 3 to 33). Treatment with ivacaftor was associated with a significant reduction of EOR symptoms (P<0∙04 versus baseline) denoted by the reflux symptom index and Hull airway reflux questionnaire. Ivacaftor treatment was beneficial for patients with symptoms of EOR, thought to be a precursor to microaspiration. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Inhibition of NFkappaB by the natural product Withaferin A in cellular models of Cystic Fibrosis inflammation.

PubMed

Maitra, Rangan; Porter, Melissa A; Huang, Shan; Gilmour, Brian P

2009-05-13

Cystic Fibrosis (CF) is one of the most common autosomal genetic disorders in humans. This disease is caused by mutations within a single gene, coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The phenotypic hallmark of CF is chronic lung infection and associated inflammation from opportunistic microbes such as Pseudomonas aeruginosa (PA), Haemophilus influenzae, and Staphylococcus aureus. This eventually leads to deterioration of lung function and death in most CF patients. Unfortunately, there is no approved therapy for correcting the genetic defect causal to the disease. Hence, controlling inflammation and infection in CF patients are critical to disease management. Accordingly, anti-inflammatory agents and antibiotics are used to manage chronic inflammation and infection in CF patients. However, most of the anti-inflammatory agents in CF have severe limitations due to adverse side effects, and resistance to antibiotics is becoming an even more prominent problem. Thus, new agents that can be used to control chronic inflammation in CF are needed in the absence of a cure for the disease. Activation of the transcription factor NFkappaB through Toll-like receptors (TLR) following bacterial infection is principally involved in regulating lung inflammation in CF. NFkappaB regulates the transcription of several genes that are involved in inflammation, anti-apoptosis and anti-microbial activity, and hyper-activation of this transcription factor leads to a potent inflammatory response. Thus, NFkappaB is a potential anti-inflammatory drug target in CF. Screening of several compounds from natural sources in an in vitro model of CF-related inflammation wherein NFkappaB is activated by filtrates of a clinically isolated strain of PA (PAF) led us to Withaferin A (WFA), a steroidal lactone from the plant Withania Somnifera L. Dunal. Our data demonstrate that WFA blocks PAF-induced activation of NFkappaB as determined using reporter assays, IL-8 measurements and high-content fluorescent imaging of NFkappaB subunit p65 translocation. Since the airways of CF patients can be specifically targeted for delivery of therapeutics, we propose that WFA should be further studied as an anti-inflammatory agent in models of CF related inflammation mediated by NFkappaB.

New and emerging targeted therapies for cystic fibrosis.

PubMed

Quon, Bradley S; Rowe, Steven M

2016-03-30

Cystic fibrosis (CF) is a monogenic autosomal recessive disorder that affects about 70,000 people worldwide. The clinical manifestations of the disease are caused by defects in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The discovery of the CFTR gene in 1989 has led to a sophisticated understanding of how thousands of mutations in the CFTR gene affect the structure and function of the CFTR protein. Much progress has been made over the past decade with the development of orally bioavailable small molecule drugs that target defective CFTR proteins caused by specific mutations. Furthermore, there is considerable optimism about the prospect of gene replacement or editing therapies to correct all mutations in cystic fibrosis. The recent approvals of ivacaftor and lumacaftor represent the genesis of a new era of precision medicine in the treatment of this condition. These drugs are having a positive impact on the lives of people with cystic fibrosis and are potentially disease modifying. This review provides an update on advances in our understanding of the structure and function of the CFTR, with a focus on state of the art targeted drugs that are in development. 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.

Congenital bilateral absence of the vas deferens (CBAVD): Possible correlation between cystic fibrosis (CF) genotype and antisperm antibodies (ASA) phenotype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kupchick, G.S.; Vazquez-Levin, M.H.; Nagler, H.M.

1994-09-01

A large number of CBAVD patients have been found to carry at least one known CF mutation. Several of these individuals have been shown to be compound heterozygotes. It is likely that most CBAVD cases represent the milder end of the CF spectrum. However, in a given CBAVD patient with no known mutations found (within current screening capabilities), it is not possible to conclude a CF relationship. Since CBAVD patients have been successfully treated for infertility with epididymal aspiration techniques, there are reproductive and clinical implications regarding CF. We have studied seven CBAVD patients (P{sub 1}-P{sub 7}) with regards tomore » presence and levels of ASA and their CF genotypes. An indirect immunobead binding test was used to measure ASA. ASA were found in 5/7 (71%) patients studied. High levels of IgG binding to sperm tail-tip were found in two cases (P{sub 2}, P{sub 4}); IgG binding to all sperm regions and IgA binding to sperm head were found in one case (P{sub 5}); IgM binding to tail-tip was found in two cases (P{sub 1}, P{sub 3}). Three patients (P{sub 1}, P{sub 3}, P{sub 4}) had a {triangle}F308 / ? and two (P{sub 2}, P{sub 5}) a W1282X / ? genotype. Interestingly, the two patients with no known mutation found (P{sub 6}, P{sub 7}) had negative ASA. The study of more patients could yield ASA as a potential indirect marker for relatedness of CBAVD to CF gene mutations.« less

[Hyperechogenic fetal bowel as a marker of fetal cystic fibrosis].

PubMed

Sukupová, M; Dhaifalah, I; Adamík, Z; Havalová, J

2015-01-01

Hyperechogenic bowel (HB) occurs in 0.1 to 1.8% of normal pregnancies. In most cases it has no consequence for the foetus, but can be associated with cystic fibrosis (CF), chromosomal defects, genetic syndromes, viral infections, gastrointestinal pathology, missed gravidity, IUGR and preterm labour. Assessment the risk of the foetus having CF or other abnormalities when HB was detected during ultrasound screening in the second trimester of pregnancy in our centre. Retrospective study. Department of Obstetrics and Gynecology, Centre of Fetal Medicine and Genetics, KNTB a.s. Zlín. Retrospective analysis of 149 cases of HB between 17 to 22 weeks of pregnancy detected from January 2008 to April 2012. HB was evaluated according to its degree of echogenicity (Slotnik/Abuhamed classification), presence or absence of other ultrasound markers and the result of first trimester combined screening result. When stage II or III HB and/or borderline risk in first trimester screening, and presence of other ultrasound markers was detected, amniocentesis (AMC) was performed to investigate the karyotype, mutations in the CFTR gene and presence of viral infections (cytomegalovirus and parvovirus B19). If stage I or II HB and/or negative I. trimester screening and no other ultrasound markers, viral infections and mutations in the CFTR gene were investigated form maternal blood. If positive, paternal blood sampling testing for mutation in the CFTR gene was performed. If a mutation was detected in both parents, AMC was performed. Mutations of the CFTR gene was investigated with a commercial panel of 33 to 50 most common mutations. Postnatally the outcome of neonatal screening for CF(IRT) and any newborns with congenital malformations were ascertained. HB was seen in 149 foetuses, AMC was performed in 94 (63%), and blood sampling in 55 (37%). Two mutations in the CFTR gene associated with a severe form of CF (deltaF508/3849 KBC +10 T) were found in one foetus from the AMC group with stage III HB. The parents decided to terminate the pregnancy. The incidence of HB in our group was 0.7%. In 4 foetuses (2.7%) with stage II HB heterozygous deltaF508 mutation was found, in the rest no mutations were detected. Parents of heterozygous carriers underwent genetic consultation. Postnatal CF screening (IRT level from a heel prick sample) was negative; therefore no further molecular genetic analysis was performed. Infection was detected in three foetuses; one case was managed with intrauterine transfusion and in the other two cases parents decided for termination. Four cases (2.7%) were terminated because of severe congenital anomalies. Minor congenital abnormalities were detected in seven (4.7%) cases. Intrauterine death was detected in three (2%) pregnancies. Based on our results, HB can be considered as a significant marker for the risk of CF, especially in HB stages II and III. It also demonstrates the importance of this marker for the risk of other foetal abnormalities.

Population Structure, Antimicrobial Resistance, and Mutation Frequencies of Streptococcus pneumoniae Isolates from Cystic Fibrosis Patients

PubMed Central

del Campo, Rosa; Morosini, María-Isabel; de la Pedrosa, Elia Gómez-G.; Fenoll, Asunción; Muñoz-Almagro, Carmen; Máiz, Luis; Baquero, Fernando; Cantón, Rafael

2005-01-01

Forty-eight Streptococcus pneumoniae isolates recovered from sputum samples from 26 cystic fibrosis (CF) patients attending our CF unit (1995 to 2003) were studied. Mean yearly incidence of isolation was 5.5%, and all were strains recovered from young patients (≤12 years). The isolation was linked to clinical exacerbation in 35% of the cases, but only 27% of these were not accompanied by other CF pathogens. Fifty percent of the patients presented with two to four isolates over the studied period. Pulsed-field gel electrophoresis-SmaI digestion revealed a high heterogeneity (32 pulsotypes among 48 isolates) and the persistence over a 6-month period of a single clone (clone A) in two patients. This clone, presenting a varied multiresistance phenotype, was identified as the Spain23F-1 clone and was also recognized in six other patients, including two out of nine patients from the CF unit of Sant Joan de Dèu Hospital, Barcelona, Spain. In our isolates, 16 different serotypes were recognized, the most frequent being 23F (33.3%), 19F (18.8%), 6A (6.2%), and 6B (6.2%). High overall resistance rates were observed: to penicillin, 73%; to cefotaxime, 33%; to erythromycin, 42%; to tetracycline, 58%; to chloramphenicol, 48%; and to trimethoprim-sulfamethoxazole, 67%. Resistance to fluoroquinolones was not detected. Multiresistance was a common feature (60%). The percentage of S. pneumoniae strains with increased frequencies of mutation to rifampin resistance (≥7.5 × 10−8) was significantly higher (P = 0.02) in CF (60%) than among non-CF (37%) isolates in the same institution (M. I. Morosini et al., Antimicrob. Agents Chemother. 47:1464-1467, 2003). Even though a clear association with acute exacerbations could not be observed, long-term clonal persistence and variability, high frequency of antibiotic resistance, and hypermutability indicate the plasticity for adaptation of S. pneumoniae to the CF lung environment. PMID:15872243

Altering intracellular pH reveals the kinetic basis of intraburst gating in the CFTR Cl− channel

PubMed Central

Xu, Weiyi; Sheppard, David N.

2017-01-01

Key points The cystic fibrosis transmembrane conductance regulator (CFTR), which is defective in the genetic disease cystic fibrosis (CF), forms a gated pathway for chloride movement regulated by intracellular ATP.To understand better CFTR function, we investigated the regulation of channel openings by intracellular pH.We found that short‐lived channel closures during channel openings represent subtle changes in the structure of CFTR that are regulated by intracellular pH, in part, at ATP‐binding site 1 formed by the nucleotide‐binding domains.Our results provide a framework for future studies to understand better the regulation of channel openings, the dysfunction of CFTR in CF and the action of drugs that repair CFTR gating defects. Abstract Cystic fibrosis transmembrane conductance regulator (CFTR) is an ATP‐gated Cl− channel defective in the genetic disease cystic fibrosis (CF). The gating behaviour of CFTR is characterized by bursts of channel openings interrupted by brief, flickery closures, separated by long closures between bursts. Entry to and exit from an open burst is controlled by the interaction of ATP with two ATP‐binding sites, sites 1 and 2, in CFTR. To understand better the kinetic basis of CFTR intraburst gating, we investigated the single‐channel activity of human CFTR at different intracellular pH (pHi) values. When compared with the control (pHi 7.3), acidifying pHi to 6.3 or alkalinizing pHi to 8.3 and 8.8 caused small reductions in the open‐time constant (τo) of wild‐type CFTR. By contrast, the fast closed‐time constant (τcf), which describes the short‐lived closures that interrupt open bursts, was greatly increased at pHi 5.8 and 6.3. To analyse intraburst kinetics, we used linear three‐state gating schemes. All data were satisfactorily modelled by the C1 ↔ O ↔ C2 kinetic scheme. Changing the intracellular ATP concentration was without effect on τo, τcf and their responses to pHi changes. However, mutations that disrupt the interaction of ATP with ATP‐binding site 1, including K464A, D572N and the CF‐associated mutation G1349D all abolished the prolongation of τcf at pHi 6.3. Taken together, our data suggest that the regulation of CFTR intraburst gating is distinct from the ATP‐dependent mechanism that controls channel opening and closing. However, our data also suggest that ATP‐binding site 1 modulates intraburst gating. PMID:27779763

Does extensive genotyping and nasal potential difference testing clarify the diagnosis of cystic fibrosis among patients with single-organ manifestations of cystic fibrosis?

PubMed

Ooi, Chee Y; Dupuis, Annie; Ellis, Lynda; Jarvi, Keith; Martin, Sheelagh; Ray, Peter N; Steele, Leslie; Kortan, Paul; Gonska, Tanja; Dorfman, Ruslan; Solomon, Melinda; Zielenski, Julian; Corey, Mary; Tullis, Elizabeth; Durie, Peter

2014-03-01

The phenotypic spectrum of cystic fibrosis (CF) has expanded to include patients affected by single-organ diseases. Extensive genotyping and nasal potential difference (NPD) testing have been proposed to assist in the diagnosis of CF when sweat testing is inconclusive. However, the diagnostic yield of extensive genotyping and NPD and the concordance between NPD and the sweat test have not been carefully evaluated. We evaluated the diagnostic outcomes of genotyping (with 122 mutations included as disease causing), sweat testing and NPD in a prospectively ascertained cohort of undiagnosed patients who presented with chronic sino-pulmonary disease (RESP), chronic/recurrent pancreatitis (PANC) or obstructive azoospermia (AZOOSP). 202 patients (68 RESP, 42 PANC and 92 AZOOSP) were evaluated; 17.3%, 22.8% and 59.9% had abnormal, borderline and normal sweat chloride results, respectively. Only 17 (8.4%) patients were diagnosable as having CF by genotyping. Compared to sweat testing, NPD identified more patients as having CF (33.2%) with fewer borderline results (18.8%). The level of agreement according to kappa statistics (and the observed percentage of agreement) between sweat chloride and NPD in RESP, PANC and AZOOSP subjects was 'moderate' (65% observed agreement), 'poor' (33% observed agreement) and 'fair' (28% observed agreement), respectively. The degree of agreement only improved marginally when subjects with borderline sweat chloride results were excluded from the analysis. The diagnosis of CF or its exclusion is not always straightforward and may remain elusive even with comprehensive evaluation, particularly among individuals who present at an older age with single-organ manifestations suggestive of CF.

In vitro pharmacologic restoration of CFTR-mediated chloride transport with sodium 4-phenylbutyrate in cystic fibrosis epithelial cells containing delta F508-CFTR.

PubMed Central

Rubenstein, R C; Egan, M E; Zeitlin, P L

1997-01-01

The most common cystic fibrosis transmembrane conductance regulator mutation, delta F508-CFTR, is a partially functional chloride channel that is retained in the endoplasmic reticulum and degraded. We hypothesize that a known transcriptional regulator, sodium 4-phenylbutyrate (4PBA), will enable a greater fraction of delta F508-CFTR to escape degradation and appear at the cell surface. Primary cultures of nasal polyp epithelia from CF patients (delta F508 homozygous or heterozygous), or the CF bronchial epithelial cell line IB3-1 (delta F508/W1282X) were exposed to 4PBA for up to 7 d in culture. 4PBA treatment at concentrations of 0.1 and 2 mM resulted in the restoration of forskolin-activated chloride secretion. Protein kinase A-activated, linear, 10 pS chloride channels appeared at the plasma membrane of IB3-1 cells at the tested concentration of 2.5 mM. Treatment of IB3-1 cells with 0.1-1 mM 4PBA and primary nasal epithelia with 5 mM 4PBA also resulted in the appearance of higher molecular mass forms of CFTR consistent with addition and modification of oligosaccharides in the Golgi apparatus, as detected by immunoblotting of whole cell lysates with anti-CFTR antisera. Immunocytochemistry in CF epithelial cells treated with 4PBA was consistent with increasing amounts of delta F508-CFTR. These data indicate that 4PBA is a promising pharmacologic agent for inducing correction of the CF phenotype in CF patients carrying the delta F508 mutation. PMID:9366560

In vitro pharmacologic restoration of CFTR-mediated chloride transport with sodium 4-phenylbutyrate in cystic fibrosis epithelial cells containing delta F508-CFTR.

PubMed

Rubenstein, R C; Egan, M E; Zeitlin, P L

1997-11-15

The most common cystic fibrosis transmembrane conductance regulator mutation, delta F508-CFTR, is a partially functional chloride channel that is retained in the endoplasmic reticulum and degraded. We hypothesize that a known transcriptional regulator, sodium 4-phenylbutyrate (4PBA), will enable a greater fraction of delta F508-CFTR to escape degradation and appear at the cell surface. Primary cultures of nasal polyp epithelia from CF patients (delta F508 homozygous or heterozygous), or the CF bronchial epithelial cell line IB3-1 (delta F508/W1282X) were exposed to 4PBA for up to 7 d in culture. 4PBA treatment at concentrations of 0.1 and 2 mM resulted in the restoration of forskolin-activated chloride secretion. Protein kinase A-activated, linear, 10 pS chloride channels appeared at the plasma membrane of IB3-1 cells at the tested concentration of 2.5 mM. Treatment of IB3-1 cells with 0.1-1 mM 4PBA and primary nasal epithelia with 5 mM 4PBA also resulted in the appearance of higher molecular mass forms of CFTR consistent with addition and modification of oligosaccharides in the Golgi apparatus, as detected by immunoblotting of whole cell lysates with anti-CFTR antisera. Immunocytochemistry in CF epithelial cells treated with 4PBA was consistent with increasing amounts of delta F508-CFTR. These data indicate that 4PBA is a promising pharmacologic agent for inducing correction of the CF phenotype in CF patients carrying the delta F508 mutation.

S737F is a new CFTR mutation typical of patients originally from the Tuscany region in Italy.

PubMed

Terlizzi, Vito; Di Lullo, Antonella Miriam; Comegna, Marika; Centrone, Claudia; Pelo, Elisabetta; Castaldo, Giuseppe; Raia, Valeria; Braggion, Cesare

2018-01-03

An increasing number of patients have been described as having a number of Cystic Fibrosis Transmembrane conductance Regulator (CFTR) variants for which it lacks a clear genotype-phenotype correlation. We assesses the clinical features of patients bearing the S737F (p.Ser737Phe) CFTR missense variant and evaluated the residual function of CFTR protein on nasal epithelial cells (NEC). A retrospective database was performed from individuals homozygous or compound heterozygous for the S737F variant followed in the Cystic Fibrosis (CF) Centre of Florence. We performed a nasal brushing in cooperating patients and compared the results with those of patients followed in the pediatric CF Centre of Naples. 9/295 (3%) subjects carrying at least S737F CFTR variant on one allele were identified. Patients were diagnosed in 7/9 cases by newborn screening and in two cases for dehydration with hypochloremic metabolic alkalosis; at diagnosis sweat chloride levels (SCL) were in the pathological range in only one case. After a mean follow up of 8,6 years (range 0,5-15,8), SCL were in the pathological range in 8/9 cases (mean age at CF diagnosis: 1,5 years), all patients were pancreatic sufficiency and respiratory function was normal. The gating activity on NEC was 15.6% and 12.7% in two patients compound heterozygous for W1282X and DelE22_24, while it was ranged between 6,2% and 9,8% in CF patients. S737F is a CFTR mutation associated to hypochloremic alkalosis in childhood, mild CF phenotype in teenage years and a residual function of CFTR protein.

Structural effects of extracellular loop mutations in CFTR helical hairpins.

PubMed

Chang, Yuan-Heng; Stone, Tracy A; Chin, Stephanie; Glibowicka, Mira; Bear, Christine E; Deber, Charles M

2018-05-01

Missense mutations constitute 40% of 2000 cystic fibrosis-phenotypic mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) database, yet the precise mechanism as to how a point mutation can render the entire 1480-residue CFTR protein dysfunctional is not well-understood. Here we investigate the structural effects of two CF-phenotypic mutations - glutamic acid to glycine at position 217 (E217G) and glutamine to arginine at position 220 (Q220R) - in the extracellular (ECL2) loop region of human CFTR using helical hairpin constructs derived from transmembrane (TM) helices 3 and 4 of the first membrane domain. We systematically replaced the wild type (WT) residues E217 and Q220 with the subset of missense mutations that could arise through a single nucleotide change in their respective codons. Circular dichroism spectra of E217G revealed that a significant increase in helicity vs. WT arises in the membrane-mimetic environment of sodium dodecylsulfate (SDS) micelles, while this mutant showed a similar gel shift to WT on SDS-PAGE gels. In contrast, the CF-mutant Q220R showed similar helicity but an increased gel shift vs. WT. These structural variations are compared with the maturation levels of the corresponding mutant full-length CFTRs, which we found are reduced to approx. 50% for E217G and 30% for Q220R vs. WT. The overall results with CFTR hairpins illustrate the range of impacts that single mutations can evoke in intramolecular protein-protein and/or protein-lipid interactions - and the levels to which corresponding mutations in full-length CFTR may be flagged by quality control mechanisms during biosynthesis. Copyright © 2018 Elsevier B.V. All rights reserved.

Pro-resolving lipid mediator Resolvin D1 serves as a marker of lung disease in cystic fibrosis.

PubMed

Eickmeier, Olaf; Fussbroich, Daniela; Mueller, Klaus; Serve, Friederike; Smaczny, Christina; Zielen, Stefan; Schubert, Ralf

2017-01-01

Cystic fibrosis (CF) is an autosomal recessive genetic disorder that affects multiple organs, including the lungs, pancreas, liver and intestine. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) locus lead to defective proteins and reduced Cl- secretion and Na+ hyperabsorption in the affected organs. In addition, patients suffering from CF display chronic inflammation that contributes to the pathogenesis of CF. Recent work suggests that CF patients have a reduced capacity to biosynthesize specialized pro-resolving lipid mediators (SPMs), which contributes to the development and duration of the unwanted inflammation. Alterations in the metabolism of arachidonic acid (AA) and docosahexaenoic acid (DHA) to specialized pro-resolving mediators (SPMs), like lipoxins (LXs), maresins (MaRs), protectins (PDs) and resolvins (Rvs), may play a major role on clinical impact of airway inflammation in CF. In this study, our aims were to detect and quantitate Resolvin D1 (RvD1) in sputum and plasma from patients with CF and compare levels of RvD1 with biomarkers of inflammation and lung function. We studied 27 CF patients aged 6 to 55 years (median 16 years) in a prospective approach. DHA can be found in the plasma of our CF patients in the milligram range and is decreased in comparison to a healthy control group. The DHA-derived pro-resolving mediator Resolvin D1 (RvD1) was also present in the plasma (286.4 ± 50 pg/ mL, mean ± SEM) and sputum (30.0 ± 2.6 pg/ mL, mean ± SEM) samples from our patients with CF and showed a positive correlation with sputum inflammatory markers. The plasma concentrations of RvD1 were ten times higher than sputum concentrations. Interestingly, sputum RvD1/ IL-8 levels showed a positive correlation with FEV1 (rs = 0.3962, p< 0.05). SPMs, like RvD1, are well known to down-regulate inflammatory pathways. Our study shows that the bioactive lipid mediator RvD1, derived from DHA, was present in sputum and plasma of CF patients and may serve as a representative peripheral biomarker of the lung resolution program for CF patients.

Pseudomonas aeruginosa in cystic fibrosis patients with G551D-CFTR treated with ivacaftor.

PubMed

Heltshe, Sonya L; Mayer-Hamblett, Nicole; Burns, Jane L; Khan, Umer; Baines, Arthur; Ramsey, Bonnie W; Rowe, Steven M

2015-03-01

Ivacaftor improves outcomes in cystic fibrosis (CF) patients with the G551D mutation; however, effects on respiratory microbiology are largely unknown. This study examines changes in CF respiratory pathogens with ivacaftor and correlates them with baseline characteristics and clinical response. The G551D Observational Study enrolled a longitudinal observational cohort of US patients with CF aged 6 years and older with at least 1 copy of the G551D mutation. Results were linked with retrospective and prospective culture data in the US Cystic Fibrosis Foundation's National Patient Registry. Pseudomonas aeruginosa infection category in the year before and year after ivacaftor was compared and correlated with clinical findings. Among 151 participants prescribed ivacaftor, 29% (26/89) who were culture positive for P. aeruginosa the year prior to ivacaftor use were culture negative the year following treatment; 88% (52/59) of those P. aeruginosa free remained uninfected. The odds of P. aeruginosa positivity in the year after ivacaftor compared with the year prior were reduced by 35% (odds ratio [OR], 0.65; P < .001). Ivacaftor was also associated with reduced odds of mucoid P. aeruginosa (OR, 0.77; P = .013) and Aspergillus (OR, 0.47; P = .039), but not Staphylococcus aureus or other common CF pathogens. Patients with intermittent culture positivity and higher forced expiratory volume in 1 second (FEV1) were most likely to turn culture negative. Reduction in P. aeruginosa was not associated with change in FEV1, body mass index, or hospitalizations. Pseudomonas aeruginosa culture positivity was significantly reduced following ivacaftor treatment. Efficacious CFTR modulation may contribute to lower frequency of culture positivity for P. aeruginosa and other respiratory pathogens, particularly in patients with less established disease. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Skin Biomarkers for Cystic Fibrosis: A Potential Non-Invasive Approach for Patient Screening.

PubMed

Esteves, Cibele Zanardi; de Aguiar Dias, Letícia; de Oliveira Lima, Estela; de Oliveira, Diogo Noin; Rodrigues Melo, Carlos Fernando Odir; Delafiori, Jeany; Souza Gomez, Carla Cristina; Ribeiro, José Dirceu; Ribeiro, Antônio Fernando; Levy, Carlos Emílio; Catharino, Rodrigo Ramos

2017-01-01

Cystic fibrosis (CF) is a disabling genetic disease with an increased prevalence in European heritage populations. Currently, the most used technique for collection of CF samples and diagnosis is provided through uncomfortable tests, with uncertain results, mostly based on chloride concentration in sweat. Since CF mutation induces many metabolic changes in patients, exploring these alterations might be an alternative to visualize potential biomarkers that could be used as interesting tools for further diagnostic upgrade, prioritizing simplicity, low cost, and quickness. This contribution describes an accurate strategy to provide potential biomarkers related to CF, which may be understood as a potential tool for new diagnostic approaches and/or for monitoring disease evolution. Therefore, the present proposal consists of using skin imprints on silica plates as a way of sample collection, followed by direct-infusion high-resolution mass spectrometry and multivariate data analysis, intending to identify metabolic changes in skin composition of CF patients. Metabolomics analysis allowed identifying chemical markers that can be traced back to CF in patients' skin imprints, differently from control subjects. Seven chemical markers from several molecular classes were elected, represented by bile acids, a glutaric acid derivative, thyrotropin-releasing hormone, an inflammatory mediator, a phosphatidic acid, and diacylglycerol isomers, all reflecting metabolic disturbances that occur due to of CF. The comfortable method of sample collection combined with the identified set of biomarkers represent potential tools that open the range of possibilities to manage CF and follow the disease evolution. This exploratory approach points to new perspectives about the development of diagnostic assay using biomarkers and the management CF.

[Mucoviscidosis: CFTR mutation-specific therapy: a ray of sunshine in a cloudy sky].

PubMed

Leonard, A; Leal, T; Lebecque, P

2013-01-01

There is a need to find a cure for pulmonary disease in cystic fibrosis (CF), though full benefit of this approach will be restricted to those patients with well-preserved lungs. The most promising route is currently that of a pharmacological mutation-specific approach aiming at correcting the mechanism by which mutations lead to impairment of chloride conductance across respiratory epithelial cells. In the past 14years, 7 candidate drugs (CPX, 4PBA, gentamicin, PTC124, VX-770 or Ivacaftor, VX-809 or Lumacaftor, and Miglustat) have been investigated in CF patients. A postulate of 14 out of the 15 published studies has been that an effective agent had to improve total chloride secretion as assessed in vivo by nasal potential difference measurements. The present review casts a critical look at these studies. Apparent inconsistencies are discussed as well as possible limitations of nasal potential difference measurements as outcome parameters in these trials. Primarily targeting a mutation carried by less than 2% of French CF patients, the 2 Ivacaftor studies could well be a milestone on the long road toward a cure for CF. However, further data on safety and long-term efficacy are obviously needed and the current price of this medication in the US would make it unaffordable for European patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Restoration of R117H CFTR folding and function in human airway cells through combination treatment with VX-809 and VX-770

PubMed Central

Gentzsch, Martina; Ren, Hong Y.; Houck, Scott A.; Quinney, Nancy L.; Cholon, Deborah M.; Sopha, Pattarawut; Chaudhry, Imron G.; Das, Jhuma; Dokholyan, Nikolay V.; Randell, Scott H.

2016-01-01

Cystic fibrosis (CF) is a lethal recessive genetic disease caused primarily by the F508del mutation in the CF transmembrane conductance regulator (CFTR). The potentiator VX-770 was the first CFTR modulator approved by the FDA for treatment of CF patients with the gating mutation G551D. Orkambi is a drug containing VX-770 and corrector VX809 and is approved for treatment of CF patients homozygous for F508del, which has folding and gating defects. At least 30% of CF patients are heterozygous for the F508del mutation with the other allele encoding for one of many different rare CFTR mutations. Treatment of heterozygous F508del patients with VX-809 and VX-770 has had limited success, so it is important to identify heterozygous patients that respond to CFTR modulator therapy. R117H is a more prevalent rare mutation found in over 2,000 CF patients. In this study we investigated the effectiveness of VX-809/VX-770 therapy on restoring CFTR function in human bronchial epithelial (HBE) cells from R117H/F508del CF patients. We found that VX-809 stimulated more CFTR activity in R117H/F508del HBEs than in F508del/F508del HBEs. R117H expressed exclusively in immortalized HBEs exhibited a folding defect, was retained in the ER, and degraded prematurely. VX-809 corrected the R117H folding defect and restored channel function. Because R117 is involved in ion conductance, VX-770 acted additively with VX-809 to restore CFTR function in chronically treated R117H/F508del cells. Although treatment of R117H patients with VX-770 has been approved, our studies indicate that Orkambi may be more beneficial for rescue of CFTR function in these patients. PMID:27402691

Restoration of R117H CFTR folding and function in human airway cells through combination treatment with VX-809 and VX-770.

PubMed

Gentzsch, Martina; Ren, Hong Y; Houck, Scott A; Quinney, Nancy L; Cholon, Deborah M; Sopha, Pattarawut; Chaudhry, Imron G; Das, Jhuma; Dokholyan, Nikolay V; Randell, Scott H; Cyr, Douglas M

2016-09-01

Cystic fibrosis (CF) is a lethal recessive genetic disease caused primarily by the F508del mutation in the CF transmembrane conductance regulator (CFTR). The potentiator VX-770 was the first CFTR modulator approved by the FDA for treatment of CF patients with the gating mutation G551D. Orkambi is a drug containing VX-770 and corrector VX809 and is approved for treatment of CF patients homozygous for F508del, which has folding and gating defects. At least 30% of CF patients are heterozygous for the F508del mutation with the other allele encoding for one of many different rare CFTR mutations. Treatment of heterozygous F508del patients with VX-809 and VX-770 has had limited success, so it is important to identify heterozygous patients that respond to CFTR modulator therapy. R117H is a more prevalent rare mutation found in over 2,000 CF patients. In this study we investigated the effectiveness of VX-809/VX-770 therapy on restoring CFTR function in human bronchial epithelial (HBE) cells from R117H/F508del CF patients. We found that VX-809 stimulated more CFTR activity in R117H/F508del HBEs than in F508del/F508del HBEs. R117H expressed exclusively in immortalized HBEs exhibited a folding defect, was retained in the ER, and degraded prematurely. VX-809 corrected the R117H folding defect and restored channel function. Because R117 is involved in ion conductance, VX-770 acted additively with VX-809 to restore CFTR function in chronically treated R117H/F508del cells. Although treatment of R117H patients with VX-770 has been approved, our studies indicate that Orkambi may be more beneficial for rescue of CFTR function in these patients. Copyright © 2016 the American Physiological Society.

Cystic fibrosis heterozygote screening in 5,161 pregnant women

DOE Office of Scientific and Technical Information (OSTI.GOV)

Witt, D.R.; Hallam, P.; Blumberg, B.

A screening program for cystic fibrosis (CF) heterozygotes was conducted in a large HMO prenatal population, to evaluate the level of interest among eligible patients, the effectiveness of prescreening education, attitudes toward the screening process, psychological effects, and utilization of prenatal diagnosis and its outcomes. The heterozygote identification rate and frequency of specific CFTR mutations were also assessed. Identified carriers were offered genetic counseling and testing of male partners. Prenatal diagnosis was offered if both partners were identified as carriers. A total of 5,161 women underwent carrier testing; 947 others completed survey instruments only. The acceptance rate of screening wasmore » high (78%), and pretest education by videotape was generally effective. Adverse psychological effects were not reported. Participants generally found screening to be desirable and useful. Screening identified 142 female heterozygotes, 109 couples in which the male partner was not a carrier, and 7 high-risk couples. The incidence of R117H mutations was much higher than expected. The number of identified carriers was much lower in Hispanics than in Caucasians. We conclude that large-scale prenatal screening for CF heterozygotes in the absence of a family history of CF is an acceptable method for identifying couples at risk for affected fetuses. Sufficient pretest education can be accomplished efficiently, test insensitivity is well accepted, adverse psychological events are not observed, and general patient satisfaction is high. 66 refs., 1 fig., 8 tabs.« less

Liver cirrhosis and portal hypertension in cystic fibrosis.

PubMed

Fustik, Stojka

2013-01-01

As the expected survival improves in individuals with the cystic fibrosis (CF), so they may be faced with a number of medical complications. The aim of this study was to analyze the prevalence of liver cirrhosis in our CF population as well as the clinical and genetic characteristics of these patients. All patients older than 2 years (n = 96) were screened for liver disease. Liver cirrhosis was defined by ultrasonographic findings of distinct heterogeneity of liver parenchyma and nodular liver surface and/or by liver biopsy findings. Enlarged spleen, distended portal vein and abnormal portal venous flow indicated portal hypertension. Clinical and genotype data were analyzed. Sixteen patients were found to have liver cirrhosis, three of them with portal hypertension. All patients had pancreatic insufficiency. Nutritional status expressed as standard deviation score (Z score) for weight, height, and body mass index was as follows: zW = -0.40 +/- 1.24, zH = -0.83 +/- 1.02, and BMI = 20.1 +/- 2.3. CF patients with liver cirrhosis generally had mild-to-moderate lung disease, with average FVC and FEV1 values of 97.1 +/- 16.5% of predicted and 87.9 +/- 23.5% of predicted, respectively. Genetic analysis showed high frequency of F508del mutation in the group with cirrhosis (90.6%). The prevalence of liver cirrhosis in our CF population older than 2 years was 16.6%. Patients with pancreatic insufficiency and severe CFTR mutations, especially F508del, were exposed to higher risk of developing liver cirrhosis. Liver cirrhosis has no significant impact on the pulmonary function and the nutritional status, until the end-stage liver disease.

Orkambi® and amplifier co-therapy improves function from a rare CFTR mutation in gene-edited cells and patient tissue.

PubMed

Molinski, Steven V; Ahmadi, Saumel; Ip, Wan; Ouyang, Hong; Villella, Adriana; Miller, John P; Lee, Po-Shun; Kulleperuma, Kethika; Du, Kai; Di Paola, Michelle; Eckford, Paul Dw; Laselva, Onofrio; Huan, Ling Jun; Wellhauser, Leigh; Li, Ellen; Ray, Peter N; Pomès, Régis; Moraes, Theo J; Gonska, Tanja; Ratjen, Felix; Bear, Christine E

2017-09-01

The combination therapy of lumacaftor and ivacaftor (Orkambi ® ) is approved for patients bearing the major cystic fibrosis (CF) mutation: ΔF508 It has been predicted that Orkambi ® could treat patients with rarer mutations of similar "theratype"; however, a standardized approach confirming efficacy in these cohorts has not been reported. Here, we demonstrate that patients bearing the rare mutation: c.3700 A>G, causing protein misprocessing and altered channel function-similar to ΔF508-CFTR, are unlikely to yield a robust Orkambi ® response. While  in silico  and biochemical studies confirmed that this mutation could be corrected and potentiated by lumacaftor and ivacaftor, respectively, this combination led to a minor in vitro response in patient-derived tissue. A CRISPR/Cas9-edited bronchial epithelial cell line bearing this mutation enabled studies showing that an "amplifier" compound, effective in increasing the levels of immature CFTR protein, augmented the Orkambi ® response. Importantly, this "amplifier" effect was recapitulated in patient-derived nasal cultures-providing the first evidence for its efficacy in augmenting Orkambi ® in tissues harboring a rare CF-causing mutation. We propose that this multi-disciplinary approach, including creation of CRISPR/Cas9-edited cells to profile modulators together with validation using primary tissue, will facilitate therapy development for patients with rare CF mutations. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Recent Progress in CFTR Interactome Mapping and Its Importance for Cystic Fibrosis.

PubMed

Lim, Sang Hyun; Legere, Elizabeth-Ann; Snider, Jamie; Stagljar, Igor

2017-01-01

Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a chloride channel found in secretory epithelia with a plethora of known interacting proteins. Mutations in the CFTR gene cause cystic fibrosis (CF), a disease that leads to progressive respiratory illness and other complications of phenotypic variance resulting from perturbations of this protein interaction network. Studying the collection of CFTR interacting proteins and the differences between the interactomes of mutant and wild type CFTR provides insight into the molecular machinery of the disease and highlights possible therapeutic targets. This mini review focuses on functional genomics and proteomics approaches used for systematic, high-throughput identification of CFTR-interacting proteins to provide comprehensive insight into CFTR regulation and function.

CFTR rescue with VX-809 and VX-770 favors the repair of primary airway epithelial cell cultures from patients with class II mutations in the presence of Pseudomonas aeruginosa exoproducts.

PubMed

Adam, Damien; Bilodeau, Claudia; Sognigbé, Laura; Maillé, Émilie; Ruffin, Manon; Brochiero, Emmanuelle

2018-04-13

Progressive airway damage due to bacterial infections, especially with Pseudomonas aeruginosa remains the first cause of morbidity and mortality in CF patients. Our previous work revealed a repair delay in CF airway epithelia compared to non-CF. This delay was partially prevented after CFTR correction (with VRT-325) in the absence of infection. Our goals were now to evaluate the effect of the Orkambi combination (CFTR VX-809 corrector + VX-770 potentiator) on the repair of CF primary airway epithelia, in infectious conditions. Primary airway epithelial cell cultures from patients with class II mutations were mechanically injured and wound healing rates and transepithelial resistances were monitored after CFTR rescue, in the absence and presence of P. aeruginosa exoproducts. Our data revealed that combined treatment with VX-809 and VX-770 elicited a greater beneficial impact on airway epithelial repair than VX-809 alone, in the absence of infection. The treatment with Orkambi was effective not only in airway epithelial cell cultures from patients homozygous for the F508del mutation but also from heterozygous patients carrying F508del and another class II mutation (N1303 K, I507del). The stimulatory effect of the Orkambi treatment was prevented by CFTR inhibition with GlyH101. Finally, Orkambi combination elicited a slight but significant improvement in airway epithelial repair and transepithelial resistance, despite the presence of P. aeruginosa exoproducts. Our findings indicate that Orkambi may favor airway epithelial integrity in CF patients with class II mutations. Complementary approaches would however be needed to further improve CFTR rescue and airway epithelial repair. Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Use of the chloride channel activator lubiprostone for constipation in adults with cystic fibrosis: a case series.

PubMed

O'Brien, Catherine E; Anderson, Paula J; Stowe, Cindy D

2010-03-01

To describe the use of lubiprostone for constipation in 3 adults with cystic fibrosis (CF). This case series describes the use of lubiprostone for the treatment of constipation in 3 adults with CF (mean +/- SD length of therapy 17.3 +/- 1.5 mo). All 3 patients were prescribed lubiprostone 24 microg twice daily after hospitalization for treatment of intestinal obstruction. Patient 1 continues on chronic polyethylene glycol (PEG) 3350 and lubiprostone and has not had a recurrence of obstruction. Patient 2 requires aggressive chronic therapy with PEG 3350, lubiprostone, and methylnaltrexone. She has had 1 recurrence of obstruction. Patient 3 continues with lubiprostone taken several times per week with good control of constipation and no recurrence of obstruction to date. The adverse effect profile has been tolerable in all 3 patients. CF is caused by a genetic mutation resulting in a dysfunctional or absent CF transmembrane conductance regulator that normally functions as a chloride channel. This results in viscous secretions in multiple organ systems including the lungs and intestinal tract. Accumulation of viscous intestinal contents contributes to constipation, which is common among adults with CF and can sometimes lead to intestinal obstruction. Lubiprostone is indicated for chronic constipation and works by activating type 2 chloride channels (ClC-2) in the intestinal tract. Because it utilizes an alternate chloride channel, lubiprostone may be especially effective for constipation in patients with CF. Lubiprostone provides an additional option for the treatment of constipation in adults with CF. Its use in the CF population deserves further study.

Prevalence of elevated liver enzymes in children with cystic fibrosis diagnosed by newborn screen.

PubMed

Woodruff, Samantha A; Sontag, Marci K; Accurso, Frank J; Sokol, Ronald J; Narkewicz, Michael R

2017-01-01

Prevalence and risks for elevated liver enzymes have not been studied systematically in children with CF identified by newborn screen. 298 CF children identified by newborn screen since 1982. AST, ALT and GGT tested at annual visits. Percent of children with 1 or ≥2 values of elevated AST, ALT and GGT determined. Relationship of liver enzymes to clinical factors or subsequent liver disease was analyzed RESULTS: At least one abnormal value for AST (63%), ALT (93%) and ALT ≥1.5× ULN (52%) occurred by 21years of age. Liver enzyme elevations were not correlated with CFTR mutation, meconium ileus or ethnicity. AST and GGT ≥1.5× ULN were associated with later advanced liver disease HR (CI) 6.53 (2.02-21.1) and 4.03 (1.15-13.45), respectively. Elevated liver enzymes are common during childhood in CF patients identified by newborn screen. Elevated AST and GGT may be markers for risk of advanced liver disease. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

A Clinical and Molecular Survey of 62 Cystic Fibrosis Patients from Umbria (Central Italy) Disclosing a High Frequency (2.4%) of the 2184insA Allele: Implications for Screening.

PubMed

Prontera, Paolo; Isidori, Ilenia; Mencarini, Valeria; Pennoni, Guido; Mencarelli, Amedea; Stangoni, Gabriela; Di Cara, Giuseppe; Verrotti, Alberto

2016-01-01

Genetic testing strategies and counseling in cystic fibrosis (CF) can be problematic due to its extreme allelic heterogeneity and the difficult clinical interpretation of rare variants. Since in a previous survey of Italian CF patients, Umbria (a small region with about 900,000 inhabitants) was excluded due to the low number of chromosomes tested (<50), we have performed a comprehensive retrospective clinical and molecular survey of 62 CF patients coming from this region. We have summarized all the genotypic and phenotypic data in a table, and we interviewed the older patients in order to obtain a comprehensive overview of their conditions. We found that the c.2052_2053insA (2184insA) variant, a class I mutation with high frequency in Eastern Europe but very rare in Italy, is the fourth most frequent allele in Umbria. The 2184insA variant was not included in the first-level regional screening, and we therefore suggest the implementation of this variant in the future. © 2016 S. Karger AG, Basel.

Correction of a Cystic Fibrosis Splicing Mutation by Antisense Oligonucleotides.

PubMed

Igreja, Susana; Clarke, Luka A; Botelho, Hugo M; Marques, Luís; Amaral, Margarida D

2016-02-01

Cystic fibrosis (CF), the most common life-threatening genetic disease in Caucasians, is caused by ∼2,000 different mutations in the CF transmembrane conductance regulator (CFTR) gene. A significant fraction of these (∼13%) affect pre-mRNA splicing for which novel therapies have been somewhat neglected. We have previously described the effect of the CFTR splicing mutation c.2657+5G>A in IVS16, showing that it originates transcripts lacking exon 16 as well as wild-type transcripts. Here, we tested an RNA-based antisense oligonucleotide (AON) strategy to correct the aberrant splicing caused by this mutation. Two AONs (AON1/2) complementary to the pre-mRNA IVS16 mutant region were designed and their effect on splicing was assessed at the RNA and protein levels, on intracellular protein localization and function. To this end, we used the 2657+5G>A mutant CFTR minigene stably expressed in HEK293 Flp-In cells that express a single copy of the transgene. RNA data from AON1-treated mutant cells show that exon 16 inclusion was almost completely restored (to 95%), also resulting in increased levels of correctly localized CFTR protein at the plasma membrane (PM) and with increased function. A novel two-color CFTR splicing reporter minigene developed here allowed the quantitative monitoring of splicing by automated microscopy localization of CFTR at the PM. The AON strategy is thus a promising therapeutic approach for the specific correction of alternative splicing. © 2015 WILEY PERIODICALS, INC.

Ivacaftor and sinonasal pathology in a cystic fibrosis patient with genotype deltaF508/S1215N.

PubMed

Vreede, C L; Berkhout, M C; Sprij, A J; Fokkens, W J; Heijerman, H G M

2015-05-01

In patients with Cystic Fibrosis and a type III mutation, ivacaftor (Kalydeco(®), Vertex) can increase the opening time of the CFTR channel and improve chloride transport. Research showed significant improvement of lung function and increase in weight following ivacaftor use. However, ivacaftor showed to have adverse events on the sinonasal system as well, such as upper respiratory tract infections, nasal congestion and headaches. This case report showed a positive effect of ivacaftor on the sinonasal pathology in a 17 year old patient with CF. After 5 months of ivacaftor use, the CT-sinus showed complete resolution of the opacification of the paranasal sinuses and a decrease in symptoms of sinonasal disease. This positive effect of ivacaftor on sinonasal pathology seems promising, therefore more research is needed to evaluate the effect of ivacaftor on the upper airways in CF. Copyright © 2014. Published by Elsevier B.V.

Cystic Fibrosis Transmembrane Conductance Regulator is an Epithelial Cell Receptor for Clearance of Pseudomonas aeruginosa from the Lung

NASA Astrophysics Data System (ADS)

Pier, Gerald B.; Grout, Martha; Zaidi, Tanweer S.

1997-10-01

The cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride ion channel, but its relationship to the primary clinical manifestation of CF, chronic Pseudomonas aeruginosa pulmonary infection, is unclear. We report that CFTR is a cellular receptor for binding, endocytosing, and clearing P. aeruginosa from the normal lung. Murine cells expressing recombinant human wild-type CFTR ingested 30-100 times as many P. aeruginosa as cells lacking CFTR or expressing mutant Δ F508 CFTR protein. Purified CFTR inhibited ingestion of P. aeruginosa by human airway epithelial cells. The first extracellular domain of CFTR specifically bound to P. aeruginosa and a synthetic peptide of this region inhibited P. aeruginosa internalization in vivo, leading to increased bacterial lung burdens. CFTR clears P. aeruginosa from the lung, indicating a direct connection between mutations in CFTR and the clinical consequences of CF.

Development of allele-specific multiplex PCR to determine the length of poly-T in intron 8 of CFTR

PubMed Central

Prada, Anne E.

2014-01-01

Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation analysis has been implemented for Cystic Fibrosis (CF) carrier screening, and molecular diagnosis of CF and congenital bilateral absence of the vas deferens (CBAVD). Although poly-T allele analysis in intron 8 of CFTR is required when a patient is positive for R117H, it is not recommended for routine carrier screening. Therefore, commercial kits for CFTR mutation analysis were designed either to mask the poly-T allele results, unless a patient is R117H positive, or to have the poly-T analysis as a standalone reflex test using the same commercial platform. There are other standalone assays developed to detect poly-T alleles, such as heteroduplex analysis, High Resolution Melting (HRM) curve analysis, allele-specific PCR (AS-PCR) and Sanger sequencing. In this report, we developed a simple and easy-to-implement multiplex AS-PCR assay using unlabeled standard length primers, which can be used as a reflex or standalone test for CFTR poly-T track analysis. Out of 115 human gDNA samples tested, results from our new AS-PCR matched to the previous known poly-T results or results from Sanger sequencing. PMID:25071991

Newborn screening for cystic fibrosis in Wisconsin: comparison of biochemical and molecular methods.

PubMed

Gregg, R G; Simantel, A; Farrell, P M; Koscik, R; Kosorok, M R; Laxova, A; Laessig, R; Hoffman, G; Hassemer, D; Mischler, E H; Splaingard, M

1997-06-01

To evaluate neonatal screening for cystic fibrosis (CF), including study of the screening procedures and characteristics of false-positive infants, over the past 10 years in Wisconsin. An important objective evolving from the original design has been to compare use of a single-tier immunoreactive trypsinogen (IRT) screening method with that of a two-tier method using IRT and analyses of samples for the most common cystic fibrosis transmembrane regulator (CFTR) (DeltaF508) mutation. We also examined the benefit of including up to 10 additional CFTR mutations in the screening protocol. From 1985 to 1994, using either the IRT or IRT/DNA protocol, 220 862 and 104 308 neonates, respectively, were screened for CF. For the IRT protocol, neonates with an IRT >/=180 ng/mL were considered positive, and the standard sweat chloride test was administered to determine CF status. For the IRT/DNA protocol, samples from the original dried-blood specimen on the Guthrie card of neonates with an IRT >/=110 ng/mL were tested for the presence of the DeltaF508 CFTR allele, and if the DNA test revealed one or two DeltaF508 alleles, a sweat test was obtained. Both screening procedures had very high specificity. The sensitivity tended to be higher with the IRT/DNA protocol, but the differences were not statistically significant. The positive predictive value of the IRT/DNA screening protocol was 15.2% compared with 6.4% if the same samples had been screened by the IRT method. Assessment of the false-positive IRT/DNA population revealed that the two-tier method eliminates the disproportionate number of infants with low Apgar scores and also the high prevalence of African-Americans identified previously in our study of newborns with high IRT levels. We found that 55% of DNA-positive CF infants were homozygous for DeltaF508 and 40% had one DeltaF508 allele. Adding analyses for 10 more CFTR mutations has only a small effect on the sensitivity but is likely to add significantly to the cost of screening. Advantages of the IRT/DNA protocol over IRT analysis include improved positive predictive value, reduction of false-positive infants, and more rapid diagnosis with elimination of recall specimens.

Disparities in Mortality of Hispanic Cystic Fibrosis Patients in the United States: A National and Regional Cohort Study.

PubMed

Rho, Jason; Ahn, Chul; Gao, Ang; Sawicki, Gregory S; Keller, Ashley; Jain, Raksha

2018-05-09

Cystic Fibrosis (CF) patients of Hispanic origin are the largest growing minority, representing 8.5% of CF patients in the United States. No national survival analysis of this group has ever been undertaken. We aimed to determine whether Hispanic ethnicity within the CF population is associated with worse outcomes and whether any geographic differences exist. Using U.S. CF Foundation Patient Registry data from 2010-2014, we performed a retrospective cohort analysis comparing survival rates between Hispanics and non-Hispanics using Kaplan-Meier and Cox regression analysis. A subject's residence was categorized into geographic regions based on U.S. Census Bureau data: Northeast, Midwest, West and South. 29,637 patients were included in the study; 2,493 identified themselves as Hispanic. Hispanics had a lower survival probability overall, with a mean age of death of 22.4 ± 9.9 years compared to non-Hispanics of 28.1 ± 10.0 years (p < 0.0001). Multivariate cox proportional hazards modeling revealed that Hispanic CF patients had a 1.27 times higher rate of death compared to non-Hispanics (95% CI: 1.05 - 1.53) after adjusting for covariates including age, sex, genetic mutations, bacterial cultures, lung function, body mass index, use of CF respiratory therapies, low socioeconomic status, pancreatic enzyme use, and CF-related diabetes. When analyzed by region, Hispanics in the Midwest, Northeast, and West had shorter median survivals compared to Non-Hispanics, which was not demonstrated in the South. CF patients of Hispanic origin have a higher mortality rate than non-Hispanic CF patients. This pattern was seen in the Midwest, Northeast, and West but not in the South.

Several siblings with Cystic Fibrosis as a risk factor for poor outcome.

PubMed

Lavie, Moran; Shemer, Ofer; Sarouk, Ifat; Bar Aluma, Bat el; Dagan, Adi; Efrati, Ori; Vilozni, Daphna

2015-01-01

Occurrence of Cystic Fibrosis (CF) in more than one member in a family is not uncommon. The aim of our study was to assess the influence of multiple siblings with CF on disease expression and outcome. Study group consisted of 2-siblings (2-sibs, n = 42) or 3/4 siblings (3/4-sibs, n = 22) with CF in one family. Each sibling was matched by age, mutation, and gender to a single CF patient. 3/4-sibs subgroup compared to singles showed a lower mean FEV1 with a faster decline rate (58.4 ± 27.5 vs. 72.7 ± 25.4 and -5 ± 6.4 vs. -1.7 ± 2.8 %predicted decline/year respectively, p < .05), more airway colonization by Pseudomonas aeruginosa and Mycobacterium abscessus (15 (68%) vs. 8 (36%) and 7 (32%) vs. 4 (18%), respectively, p < .05) and more lung transplants (5 (23%) vs. 2 (9%), respectively, p < .02). Last mean FEV1 within 3/4-sibs was significantly lower for the youngest sib (p < .05). Three or more CF patients in one family may be a risk factor for more severe disease and poor prognosis. In our view this reflects the burden of disease on the patients and families. Copyright © 2014 Elsevier Ltd. All rights reserved.

Selection of nitrogen-fixing deficient Burkholderia vietnamiensis strains by cystic fibrosis patients: involvement of nif gene deletions and auxotrophic mutations.

PubMed

Menard, Aymeric; Monnez, Claire; Estrada de Los Santos, Paulina; Segonds, Christine; Caballero-Mellado, Jesus; Lipuma, John J; Chabanon, Gerard; Cournoyer, Benoit

2007-05-01

Burkholderia vietnamiensis is the third most prevalent species of the Burkholderia cepacia complex (Bcc) found in cystic fibrosis (CF) patients. Its ability at fixing nitrogen makes it one of the main Bcc species showing strong filiations with environmental reservoirs. In this study, 83% (29 over 35) of the B. vietnamiensis CF isolates and 100% of the environmental ones (over 29) were found expressing the dinitrogenase complex (encoded by the nif cluster) which is essential in N(2) fixation. Among the deficient strains, two were found growing with ammonium chloride suggesting that they were defective in N(2) fixation, and four with amino acids supplements suggesting that they were harbouring auxotrophic mutations. To get insights about the genetic events that led to the emergence of the N(2)-fixing defective strains, a genetic analysis of B. vietnamiensis nitrogen-fixing property was undertaken. A 40-kb-long nif cluster and nif regulatory genes were identified within the B. vietnamiensis strain G4 genome sequence, and analysed. Transposon mutagenesis and nifH genetic marker exchanges showed the nif cluster and several other genes like gltB (encoding a subunit of the glutamate synthase) to play a key role in B. vietnamiensis ability at growing in nitrogen-free media. nif cluster DNA probings of restricted genomic DNA blots showed a full deletion of the nif cluster for one of the N(2)-fixing defective strain while the other one showed a genetic organization similar to the one of the G4 strain. For 17% of B. vietnamiensis clinical strains, CF lungs appeared to have favoured the selection of mutations or deletions leading to N(2)-fixing deficiencies.

Next generation diagnostics of cystic fibrosis and CFTR-related disorders by targeted multiplex high-coverage resequencing of CFTR.

PubMed

Trujillano, D; Ramos, M D; González, J; Tornador, C; Sotillo, F; Escaramis, G; Ossowski, S; Armengol, L; Casals, T; Estivill, X

2013-07-01

Here we have developed a novel and much more efficient strategy for the complete molecular characterisation of the cystic fibrosis (CF) transmembrane regulator (CFTR) gene, based on multiplexed targeted resequencing. We have tested this approach in a cohort of 92 samples with previously characterised CFTR mutations and polymorphisms. After enrichment of the pooled barcoded DNA libraries with a custom NimbleGen SeqCap EZ Choice array (Roche) and sequencing with a HiSeq2000 (Illumina) sequencer, we applied several bioinformatics tools to call mutations and polymorphisms in CFTR. The combination of several bioinformatics tools allowed us to detect all known pathogenic variants (point mutations, short insertions/deletions, and large genomic rearrangements) and polymorphisms (including the poly-T and poly-thymidine-guanine polymorphic tracts) in the 92 samples. In addition, we report the precise characterisation of the breakpoints of seven genomic rearrangements in CFTR, including those of a novel deletion of exon 22 and a complex 85 kb inversion which includes two large deletions affecting exons 4-8 and 12-21, respectively. This work is a proof-of-principle that targeted resequencing is an accurate and cost-effective approach for the genetic testing of CF and CFTR-related disorders (ie, male infertility) amenable to the routine clinical practice, and ready to substitute classical molecular methods in medical genetics.

Mechanism-based corrector combination restores ΔF508-CFTR folding and function

PubMed Central

Okiyoneda, Tsukasa; Veit, Guido; Dekkers, Johanna F.; Bagdany, Miklos; Soya, Naoto; Xu, Haijin; Roldan, Ariel; Verkman, Alan S.; Kurth, Mark; Simon, Agnes; Hegedus, Tamas; Beekman, Jeffrey M.; Lukacs, Gergely L.

2013-01-01

The most common cystic fibrosis (CF) mutation, ΔF508 in the nucleotide binding domain-1 (NBD1), impairs CFTR coupled-domain folding, plasma membrane (PM) expression, function and stability. VX-809, a promising investigational corrector of ΔF508-CFTR misprocessing, has limited clinical benefit and incompletely understood mechanism, hampering drug development. Based on the effect of second site suppressor mutations, robust ΔF508-CFTR correction likely requires stabilization of NBD1 and the membrane spanning domains (MSDs)-NBD1 interface, both established primary conformational defects. Here, we elucidated the molecular targets of available correctors; class-I stabilizes the NBD1-MSD1/2 interface, class-II targets NBD2, and only chemical chaperones, surrogates of class-III correctors, stabilize the human ΔF508-NBD1. While VX-809 can correct missense mutations primarily destabilizing the NBD1-MSD1/2 interface, functional PM expression of ΔF508-CFTR also requires compounds that counteract the NBD1 and NBD2 stability defects in CF bronchial epithelial cells and intestinal organoids. Thus, structure-guided corrector combination represents an effective approach for CF therapy. PMID:23666117

Disease phenotype of a ferret CFTR-knockout model of cystic fibrosis

PubMed Central

Sun, Xingshen; Sui, Hongshu; Fisher, John T.; Yan, Ziying; Liu, Xiaoming; Cho, Hyung-Ju; Joo, Nam Soo; Zhang, Yulong; Zhou, Weihong; Yi, Yaling; Kinyon, Joann M.; Lei-Butters, Diana C.; Griffin, Michelle A.; Naumann, Paul; Luo, Meihui; Ascher, Jill; Wang, Kai; Frana, Timothy; Wine, Jeffrey J.; Meyerholz, David K.; Engelhardt, John F.

2010-01-01

Cystic fibrosis (CF) is a recessive disease that affects multiple organs. It is caused by mutations in CFTR. Animal modeling of this disease has been challenging, with species- and strain-specific differences in organ biology and CFTR function influencing the emergence of disease pathology. Here, we report the phenotype of a CFTR-knockout ferret model of CF. Neonatal CFTR-knockout ferrets demonstrated many of the characteristics of human CF disease, including defective airway chloride transport and submucosal gland fluid secretion; variably penetrant meconium ileus (MI); pancreatic, liver, and vas deferens disease; and a predisposition to lung infection in the early postnatal period. Severe malabsorption by the gastrointestinal (GI) tract was the primary cause of death in CFTR-knockout kits that escaped MI. Elevated liver function tests in CFTR-knockout kits were corrected by oral administration of ursodeoxycholic acid, and the addition of an oral proton-pump inhibitor improved weight gain and survival. To overcome the limitations imposed by the severe intestinal phenotype, we cloned 4 gut-corrected transgenic CFTR-knockout kits that expressed ferret CFTR specifically in the intestine. One clone passed feces normally and demonstrated no detectable ferret CFTR expression in the lung or liver. The animals described in this study are likely to be useful tools for dissecting CF disease pathogenesis and developing treatments. PMID:20739752

Disease phenotype of a ferret CFTR-knockout model of cystic fibrosis.

PubMed

Sun, Xingshen; Sui, Hongshu; Fisher, John T; Yan, Ziying; Liu, Xiaoming; Cho, Hyung-Ju; Joo, Nam Soo; Zhang, Yulong; Zhou, Weihong; Yi, Yaling; Kinyon, Joann M; Lei-Butters, Diana C; Griffin, Michelle A; Naumann, Paul; Luo, Meihui; Ascher, Jill; Wang, Kai; Frana, Timothy; Wine, Jeffrey J; Meyerholz, David K; Engelhardt, John F

2010-09-01

Cystic fibrosis (CF) is a recessive disease that affects multiple organs. It is caused by mutations in CFTR. Animal modeling of this disease has been challenging, with species- and strain-specific differences in organ biology and CFTR function influencing the emergence of disease pathology. Here, we report the phenotype of a CFTR-knockout ferret model of CF. Neonatal CFTR-knockout ferrets demonstrated many of the characteristics of human CF disease, including defective airway chloride transport and submucosal gland fluid secretion; variably penetrant meconium ileus (MI); pancreatic, liver, and vas deferens disease; and a predisposition to lung infection in the early postnatal period. Severe malabsorption by the gastrointestinal (GI) tract was the primary cause of death in CFTR-knockout kits that escaped MI. Elevated liver function tests in CFTR-knockout kits were corrected by oral administration of ursodeoxycholic acid, and the addition of an oral proton-pump inhibitor improved weight gain and survival. To overcome the limitations imposed by the severe intestinal phenotype, we cloned 4 gut-corrected transgenic CFTR-knockout kits that expressed ferret CFTR specifically in the intestine. One clone passed feces normally and demonstrated no detectable ferret CFTR expression in the lung or liver. The animals described in this study are likely to be useful tools for dissecting CF disease pathogenesis and developing treatments.

Anchored PDE4 regulates chloride conductance in wild-type and ΔF508-CFTR human airway epithelia

PubMed Central

Blanchard, Elise; Zlock, Lorna; Lao, Anna; Mika, Delphine; Namkung, Wan; Xie, Moses; Scheitrum, Colleen; Gruenert, Dieter C.; Verkman, Alan S.; Finkbeiner, Walter E.; Conti, Marco; Richter, Wito

2014-01-01

Cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) that impair its expression and/or chloride channel function. Here, we provide evidence that type 4 cyclic nucleotide phosphodiesterases (PDE4s) are critical regulators of the cAMP/PKA-dependent activation of CFTR in primary human bronchial epithelial cells. In non-CF cells, PDE4 inhibition increased CFTR activity under basal conditions (ΔISC 7.1 μA/cm2) and after isoproterenol stimulation (increased ΔISC from 13.9 to 21.0 μA/cm2) and slowed the return of stimulated CFTR activity to basal levels by >3-fold. In cells homozygous for ΔF508-CFTR, the most common mutation found in CF, PDE4 inhibition alone produced minimal channel activation. However, PDE4 inhibition strongly amplified the effects of CFTR correctors, drugs that increase expression and membrane localization of CFTR, and/or CFTR potentiators, drugs that increase channel gating, to reach ∼25% of the chloride conductance observed in non-CF cells. Biochemical studies indicate that PDE4s are anchored to CFTR and mediate a local regulation of channel function. Taken together, our results implicate PDE4 as an important determinant of CFTR activity in airway epithelia, and support the use of PDE4 inhibitors to potentiate the therapeutic benefits of CFTR correctors and potentiators.—Blanchard, E., Zlock, L., Lao, A., Mika, D., Namkung, W., Xie, M., Scheitrum, C., Gruenert, D.C., Verkman, A.S., Finkbeiner, W.E., Conti, M., Richter, W. Anchored PDE4 regulates chloride conductance in wild type and ΔF508-CFTR human airway epithelia. PMID:24200884

Understanding the Pathogenicity of Burkholderia contaminans, an Emerging Pathogen in Cystic Fibrosis.

PubMed

Nunvar, Jaroslav; Kalferstova, Lucie; Bloodworth, Ruhi A M; Kolar, Michal; Degrossi, Jose; Lubovich, Silvina; Cardona, Silvia T; Drevinek, Pavel

2016-01-01

Several bacterial species from the Burkholderia cepacia complex (Bcc) are feared opportunistic pathogens that lead to debilitating lung infections with a high risk of developing fatal septicemia in cystic fibrosis (CF) patients. However, the pathogenic potential of other Bcc species is yet unknown. To elucidate clinical relevance of Burkholderia contaminans, a species frequently isolated from CF respiratory samples in Ibero-American countries, we aimed to identify its key virulence factors possibly linked with an unfavorable clinical outcome. We performed a genome-wide comparative analysis of two isolates of B. contaminans ST872 from sputum and blood culture of a female CF patient in Argentina. RNA-seq data showed significant changes in expression for quorum sensing-regulated virulence factors and motility and chemotaxis. Furthermore, we detected expression changes in a recently described low-oxygen-activated (lxa) locus which encodes stress-related proteins, and for two clusters responsible for the biosynthesis of antifungal and hemolytic compounds pyrrolnitrin and occidiofungin. Based on phenotypic assays that confirmed changes in motility and in proteolytic, hemolytic and antifungal activities, we were able to distinguish two phenotypes of B. contaminans that coexisted in the host and entered her bloodstream. Whole genome sequencing revealed that the sputum and bloodstream isolates (each representing a distinct phenotype) differed by over 1,400 mutations as a result of a mismatch repair-deficient hypermutable state of the sputum isolate. The inferred lack of purifying selection against nonsynonymous mutations and the high rate of pseudogenization in the derived isolate indicated limited evolutionary pressure during evolution in the nutrient-rich, stable CF sputum environment. The present study is the first to examine the genomic and transcriptomic differences between longitudinal isolates of B. contaminans. Detected activity of a number of putative virulence factors implies a genuine pathogenic nature of this novel Bcc species.

Relative Contribution of Genetic and Non-genetic Modifiers to Intestinal Obstruction in Cystic Fibrosis

PubMed Central

Blackman, Scott M.; Deering-Brose, Rebecca; McWilliams, Rita; Naughton, Kathleen; Coleman, Barbara; Lai, Teresa; Algire, Marilyn; Beck, Suzanne; Hoover-Fong, Julie; Hamosh, Ada; Fallin, M. Daniele; West, Kristen; Arking, Dan E.; Chakravarti, Aravinda; Cutler, David J.; Cutting, Garry R

2006-01-01

Background & Aims Neonatal intestinal obstruction (meconium ileus or MI) occurs in 15% of patients with cystic fibrosis (CF). Our aim was to determine the relative contribution of genetic and non-genetic modifiers to the development of this major complication of CF. Methods Using clinical data and DNA collected by the CF Twin and Sibling Study, 65 monozygous twin pairs, 23 dizygous twin/triplet sets, and 349 sets of siblings with CF were analyzed for MI status, significant covariates, and genome-wide linkage. Results Specific mutations in CFTR, the gene responsible for CF, correlated with MI indicating a role for CFTR genotype. Monozygous twins showed substantially greater concordance for MI than dizygous twins and siblings (p=1×10−5) demonstrating that modifier genes independent of CFTR contribute substantially to this trait. Regression analysis revealed that MI was correlated with distal intestinal obstruction syndrome (DIOS; p=8×10−4). Unlike MI, concordance analysis indicated that the risk for development of DIOS in CF patients is primarily due to non-genetic factors. Regions of suggestive linkage (logarithm of the odds of linkage >2.0) for modifier genes that cause MI (chromosomes 4q35.1, 8p23.1, and 11q25) or protect from MI (chromosomes 20p11.22 and 21q22.3) were identified by genome-wide analyses. These analyses did not support the existence of a major modifier gene within the CFM1 region on chromosome 19 that had previously been linked to MI. Conclusions The CFTR gene along with two or more modifier genes are the major determinants of intestinal obstruction in newborn CF patients, while intestinal obstruction in older CF patients is primarily due to non-genetic factors. PMID:17030173

GeneChip{sup {trademark}} screening assay for cystic fibrosis mutations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cronn, M.T.; Miyada, C.G.; Fucini, R.V.

1994-09-01

GeneChip{sup {trademark}} assays are based on high density, carefully designed arrays of short oligonucleotide probes (13-16 bases) built directly on derivatized silica substrates. DNA target sequence analysis is achieved by hybridizing fluorescently labeled amplification products to these arrays. Fluorescent hybridization signals located within the probe array are translated into target sequence information using the known probe sequence at each array feature. The mutation screening assay for cystic fibrosis includes sets of oligonucleotide probes designed to detect numerous different mutations that have been described in 14 exons and one intron of the CFTR gene. Each mutation site is addressed by amore » sub-array of at least 40 probe sequences, half designed to detect the wild type gene sequence and half designed to detect the reported mutant sequence. Hybridization with homozygous mutant, homozygous wild type or heterozygous targets results in distinctive hybridization patterns within a sub-array, permitting specific discrimination of each mutation. The GeneChip probe arrays are very small (approximately 1 cm{sup 2}). There miniature size coupled with their high information content make GeneChip probe arrays a useful and practical means for providing CF mutation analysis in a clinical setting.« less

Expression of the cystic fibrosis transmembrane conductance regulator gene in the respiratory tract of normal individuals and individuals with cystic fibrosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trapnell, B.C.; Chinshyan Chu; Paakko, P.K.

1991-08-01

The most common mutation of the cystic fibrosis transmembrane conductance regulator gene, CFTR, associated with the clinical disorder cystic fibrosis (CF) is called {Delta}Phe{sup 508}, a triple-base deletion resulting in loss of phenylalanine at residue 508 of the predicted 1480-amino acid CFTR protein. In the context that the lung is the major site of morbidity and mortality in CF, the authors evaluated airway epithelial cells for CFTR mRNA transcripts in normal individuals, normal-{Delta}Phe{sup 508} heterozygotes, and {Delta}Phe{sup 508} homozygotes to determine if the normal and {Delta}Phe{sup 508} CFTR alleles are expressed in the respiratory epithelium, to what extent they aremore » expressed, and whether there are relative differences in the expression of the normal and abnormal alleles at the mRNA level. Respiratory tract epithelial cells recovered by fiberoptic bronchoscopy with a cytology brush demonstrated CFTR mRNA transcripts with sequences appropriately reflecting the normal and {Delta}Phe{sup 508} CFTR alleles of the various study groups. CFTR gene expression quantified by limited polymerase chain reaction amplification showed that in normal individuals, CFTR mRNA transcripts are expressed in nasal, tracheal, and bronchial epithelial cells.« less

Mechanisms of reduced susceptibility and genotypic prediction of antibiotic resistance in Prevotella isolated from cystic fibrosis (CF) and non-CF patients

PubMed Central

Sherrard, Laura J.; Schaible, Bettina; Graham, Kathryn A.; McGrath, Stef J.; McIlreavey, Leanne; Hatch, Joseph; Wolfgang, Matthew C.; Muhlebach, Marianne S.; Gilpin, Deirdre F.; Schneiders, Thamarai; Elborn, J. Stuart; Tunney, Michael M.

2014-01-01

Objectives To investigate mechanisms of reduced susceptibility to commonly used antibiotics in Prevotella cultured from patients with cystic fibrosis (CF), patients with invasive infection and healthy control subjects and to determine whether genotype can be used to predict phenotypic resistance. Methods The susceptibility of 157 Prevotella isolates to seven antibiotics was compared, with detection of resistance genes (cfxA-type gene, ermF and tetQ), mutations within the CfxA-type β-lactamase and expression of efflux pumps. Results Prevotella isolates positive for a cfxA-type gene had higher MICs of amoxicillin and ceftazidime compared with isolates negative for this gene (P < 0.001). A mutation within the CfxA-type β-lactamase (Y239D) was associated with ceftazidime resistance (P = 0.011). The UK CF isolates were 5.3-fold, 2.7-fold and 5.7-fold more likely to harbour ermF compared with the US CF, UK invasive and UK healthy control isolates, respectively. Higher concentrations of azithromycin (P < 0.001) and clindamycin (P < 0.001) were also required to inhibit the growth of the ermF-positive isolates compared with ermF-negative isolates. Furthermore, tetQ-positive Prevotella isolates had higher MICs of tetracycline (P = 0.001) and doxycycline (P < 0.001) compared with tetQ-negative isolates. Prevotella spp. were also shown, for the first time, to express resistance nodulation division (RND)-type efflux pumps. Conclusions This study has demonstrated that Prevotella isolated from various sources harbour a common pool of resistance genes and possess RND-type efflux pumps, which may contribute to tetracycline resistance. The findings indicate that antibiotic resistance is common in Prevotella spp., but the genotypic traits investigated do not reflect phenotypic antibiotic resistance in every instance. PMID:24917582

Cystic fibrosis gene modifier SLC26A9 modulates airway response to CFTR-directed therapeutics.

PubMed

Strug, Lisa J; Gonska, Tanja; He, Gengming; Keenan, Katherine; Ip, Wan; Boëlle, Pierre-Yves; Lin, Fan; Panjwani, Naim; Gong, Jiafen; Li, Weili; Soave, David; Xiao, Bowei; Tullis, Elizabeth; Rabin, Harvey; Parkins, Michael D; Price, April; Zuberbuhler, Peter C; Corvol, Harriet; Ratjen, Felix; Sun, Lei; Bear, Christine E; Rommens, Johanna M

2016-10-15

Cystic fibrosis is realizing the promise of personalized medicine. Recent advances in drug development that target the causal CFTR directly result in lung function improvement, but variability in response is demanding better prediction of outcomes to improve management decisions. The genetic modifier SLC26A9 contributes to disease severity in the CF pancreas and intestine at birth and here we assess its relationship with disease severity and therapeutic response in the airways. SLC26A9 association with lung disease was assessed in individuals from the Canadian and French CF Gene Modifier consortia with CFTR-gating mutations and in those homozygous for the common Phe508del mutation. Variability in response to a CFTR-directed therapy attributed to SLC26A9 genotype was assessed in Canadian patients with gating mutations. A primary airway model system determined if SLC26A9 shows modification of Phe508del CFTR function upon treatment with a CFTR corrector. In those with gating mutations that retain cell surface-localized CFTR we show that SLC26A9 modifies lung function while this is not the case in individuals homozygous for Phe508del where cell surface expression is lacking. Treatment response to ivacaftor, which aims to improve CFTR-channel opening probability in patients with gating mutations, shows substantial variability in response, 28% of which can be explained by rs7512462 in SLC26A9 (P = 0.0006). When homozygous Phe508del primary bronchial cells are treated to restore surface CFTR, SLC26A9 likewise modifies treatment response (P = 0.02). Our findings indicate that SLC26A9 airway modification requires CFTR at the cell surface, and that a common variant in SLC26A9 may predict response to CFTR-directed therapeutics.

Cystic fibrosis epithelial cells are primed for apoptosis as a result of increased Fas (CD95).

PubMed

Chen, Qiwei; Pandi, Sudha Priya Soundara; Kerrigan, Lauren; McElvaney, Noel G; Greene, Catherine M; Elborn, J Stuart; Taggart, Clifford C; Weldon, Sinéad

2018-02-24

Previous work suggests that apoptosis is dysfunctional in cystic fibrosis (CF) airways with conflicting results. We evaluated the relationship between dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) and apoptosis in CF airway epithelial cells. Apoptosis and associated caspase activity were analysed in non-CF and CF tracheal and bronchial epithelial cell lines. Basal levels of apoptosis and activity of caspase-3 and caspase-8 were significantly increased in CF epithelial cells compared to controls, suggesting involvement of extrinsic apoptosis signalling, which is mediated by the activation of death receptors, such as Fas (CD95). Increased levels of Fas were observed in CF epithelial cells and bronchial brushings from CF patients compared to non-CF controls. Neutralisation of Fas significantly inhibited caspase-3 activity in CF epithelial cells compared to untreated cells. In addition, activation of Fas significantly increased caspase-3 activity and apoptosis in CF epithelial cells compared to control cells. Overall, these results suggest that CF airway epithelial cells are more sensitive to apoptosis via increased levels of Fas and subsequent activation of the Fas death receptor pathway, which may be associated with dysfunctional CFTR. Copyright © 2018 European Cystic Fibrosis Society. All rights reserved.

Zinc supplementation in children with cystic fibrosis

USDA-ARS?s Scientific Manuscript database

Cystic fibrosis (CF) leads to malabsorption of macro- and micronutrients. Symptomatic zinc deficiency has been reported in CF but little is known about zinc homeostasis in children with CF. Zinc supplementation (Zn suppl) is increasingly common in children with CF but it is not without theoretcial r...

Gastrointestinal Pathology in Juvenile and Adult CFTR-Knockout Ferrets

PubMed Central

Sun, Xingshen; Olivier, Alicia K.; Yi, Yaling; Pope, Christopher E.; Hayden, Hillary S.; Liang, Bo; Sui, Hongshu; Zhou, Weihong; Hager, Kyle R.; Zhang, Yulong; Liu, Xiaoming; Yan, Ziying; Fisher, John T.; Keiser, Nicholas W.; Song, Yi; Tyler, Scott R.; Goeken, J. Adam; Kinyon, Joann M.; Radey, Matthew C.; Fligg, Danielle; Wang, Xiaoyan; Xie, Weiliang; Lynch, Thomas J.; Kaminsky, Paul M.; Brittnacher, Mitchell J.; Miller, Samuel I.; Parekh, Kalpaj; Meyerholz, David K.; Hoffman, Lucas R.; Frana, Timothy; Stewart, Zoe A.; Engelhardt, John F.

2015-01-01

Cystic fibrosis (CF) is a multiorgan disease caused by loss of a functional cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel in many epithelia of the body. Here we report the pathology observed in the gastrointestinal organs of juvenile to adult CFTR-knockout ferrets. CF gastrointestinal manifestations included gastric ulceration, intestinal bacterial overgrowth with villous atrophy, and rectal prolapse. Metagenomic phylogenetic analysis of fecal microbiota by deep sequencing revealed considerable genotype-independent microbial diversity between animals, with the majority of taxa overlapping between CF and non-CF pairs. CF hepatic manifestations were variable, but included steatosis, necrosis, biliary hyperplasia, and biliary fibrosis. Gallbladder cystic mucosal hyperplasia was commonly found in 67% of CF animals. The majority of CF animals (85%) had pancreatic abnormalities, including extensive fibrosis, loss of exocrine pancreas, and islet disorganization. Interestingly, 2 of 13 CF animals retained predominantly normal pancreatic histology (84% to 94%) at time of death. Fecal elastase-1 levels from these CF animals were similar to non-CF controls, whereas all other CF animals evaluated were pancreatic insufficient (<2 μg elastase-1 per gram of feces). These findings suggest that genetic factors likely influence the extent of exocrine pancreas disease in CF ferrets and have implications for the etiology of pancreatic sufficiency in CF patients. In summary, these studies demonstrate that the CF ferret model develops gastrointestinal pathology similar to CF patients. PMID:24637292

Antibiotic resistance and population structure of cystic fibrosis Pseudomonas aeruginosa isolates from a Spanish multi-centre study.

PubMed

López-Causapé, Carla; de Dios-Caballero, Juan; Cobo, Marta; Escribano, Amparo; Asensio, Óscar; Oliver, Antonio; Del Campo, Rosa; Cantón, Rafael; Solé, Amparó; Cortell, Isidoro; Asensio, Oscar; García, Gloria; Martínez, María Teresa; Cols, María; Salcedo, Antonio; Vázquez, Carlos; Baranda, Félix; Girón, Rosa; Quintana, Esther; Delgado, Isabel; de Miguel, María Ángeles; García, Marta; Oliva, Concepción; Prados, María Concepción; Barrio, María Isabel; Pastor, María Dolores; Olveira, Casilda; de Gracia, Javier; Álvarez, Antonio; Escribano, Amparo; Castillo, Silvia; Figuerola, Joan; Togores, Bernat; Oliver, Antonio; López, Carla; de Dios Caballero, Juan; Tato, Marta; Máiz, Luis; Suárez, Lucrecia; Cantón, Rafael

2017-09-01

The first Spanish multi-centre study on the microbiology of cystic fibrosis (CF) was conducted from 2013 to 2014. The study involved 24 CF units from 17 hospitals, and recruited 341 patients. The aim of this study was to characterise Pseudomonas aeruginosa isolates, 79 of which were recovered from 75 (22%) patients. The study determined the population structure, antibiotic susceptibility profile and genetic background of the strains. Fifty-five percent of the isolates were multi-drug-resistant, and 16% were extensively-drug-resistant. Defective mutS and mutL genes were observed in mutator isolates (15.2%). Considerable genetic diversity was observed by pulsed-field gel electrophoresis (70 patterns) and multi-locus sequence typing (72 sequence types). International epidemic clones were not detected. Fifty-one new and 14 previously described array tube (AT) genotypes were detected by AT technology. This study found a genetically unrelated and highly diverse CF P. aeruginosa population in Spain, not represented by the epidemic clones widely distributed across Europe, with multiple combinations of virulence factors and high antimicrobial resistance rates (except for colistin). Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Oxidative stress modulates the expression of genes involved in cell survival in ΔF508 cystic fibrosis airway epithelial cells.

PubMed

Voisin, Grégory; Bouvet, Guillaume F; Legendre, Pierre; Dagenais, André; Massé, Chantal; Berthiaume, Yves

2014-09-01

Although cystic fibrosis (CF) pathophysiology is explained by a defect in CF transmembrane conductance regulator (CFTR) protein, the broad spectrum of disease severity is the consequence of environmental and genetic factors. Among them, oxidative stress has been demonstrated to play an important role in the evolution of this disease, with susceptibility to oxidative damage, decline of pulmonary function, and impaired lung antioxidant defense. Although oxidative stress has been implicated in the regulation of inflammation, its molecular outcomes in CF cells remain to be evaluated. To address the question, we compared the gene expression profile in NuLi-1 cells with wild-type CFTR and CuFi-1 cells homozygous for ΔF508 mutation cultured at air-liquid interface. We analyzed the transcriptomic response of these cell lines with microarray technology, under basal culture conditions and after 24 h oxidative stress induced by 15 μM 2,3-dimethoxy-1,4-naphtoquinone. In the absence of oxidative conditions, CuFi-1 gene profiling showed typical dysregulated inflammatory responses compared with NuLi-1. In the presence of oxidative conditions, the transcriptome of CuFi-1 cells reflected apoptotic transcript modulation. These results were confirmed in the CFBE41o- and corrCFBE41o- cell lines as well as in primary culture of human CF airway epithelial cells. Altogether, our data point to the influence of oxidative stress on cell survival functions in CF and identify several genes that could be implicated in the inflammation response observed in CF patients. Copyright © 2014 the American Physiological Society.

Diagnosis of Cystic Fibrosis in Screened Populations.

PubMed

Farrell, Philip M; White, Terry B; Howenstine, Michelle S; Munck, Anne; Parad, Richard B; Rosenfeld, Margaret; Sommerburg, Olaf; Accurso, Frank J; Davies, Jane C; Rock, Michael J; Sanders, Don B; Wilschanski, Michael; Sermet-Gaudelus, Isabelle; Blau, Hannah; Gartner, Silvia; McColley, Susanna A

2017-02-01

Cystic fibrosis (CF) can be difficult to diagnose, even when newborn screening (NBS) tests yield positive results. This challenge is exacerbated by the multitude of NBS protocols, misunderstandings about screening vs diagnostic tests, and the lack of guidelines for presumptive diagnoses. There is also confusion regarding the designation of age at diagnosis. To improve diagnosis and achieve standardization in definitions worldwide, the CF Foundation convened a committee of 32 experts with a mission to develop clear and actionable consensus guidelines on diagnosis of CF with an emphasis on screened populations, especially the newborn population. A comprehensive literature review was performed with emphasis on relevant articles published during the past decade. After reviewing the common screening protocols and outcome scenarios, 14 of 27 consensus statements were drafted that apply to screened populations. These were approved by 80% or more of the participants. It is recommended that all diagnoses be established by demonstrating dysfunction of the CF transmembrane conductance regulator (CFTR) channel, initially with a sweat chloride test and, when needed, potentially with newer methods assessing membrane transport directly, such as intestinal current measurements. Even in babies with 2 CF-causing mutations detected via NBS, diagnosis must be confirmed by demonstrating CFTR dysfunction. The committee also recommends that the latest classifications identified in the Clinical and Functional Translation of CFTR project [http://www.cftr2.org/index.php] should be used to aid with CF diagnosis. Finally, to avoid delays in treatment, we provide guidelines for presumptive diagnoses and recommend how to determine the age of diagnosis. Copyright © 2016. Published by Elsevier Inc.

Inhibition of Protease-Epithelial Sodium Channel Signaling Improves Mucociliary Function in Cystic Fibrosis Airways.

PubMed

Reihill, James A; Walker, Brian; Hamilton, Robert A; Ferguson, Timothy E G; Elborn, J Stuart; Stutts, M Jackson; Harvey, Brian J; Saint-Criq, Vinciane; Hendrick, Siobhan M; Martin, S Lorraine

2016-09-15

In cystic fibrosis (CF) a reduction in airway surface liquid (ASL) height compromises mucociliary clearance, favoring mucus plugging and chronic bacterial infection. Inhibitors of the epithelial sodium channel (ENaC) have therapeutic potential in CF airways to reduce hyperstimulated sodium and fluid absorption to levels that can restore airway hydration. To determine whether a novel compound (QUB-TL1) designed to inhibit protease/ENaC signaling in CF airways restores ASL volume and mucociliary function. Protease activity was measured using fluorogenic activity assays. Differentiated primary airway epithelial cell cultures (F508del homozygotes) were used to determined ENaC activity (Ussing chamber recordings), ASL height (confocal microscopy), and mucociliary function (by tracking the surface flow of apically applied microbeads). Cell toxicity was measured using a lactate dehydrogenase assay. QUB-TL1 inhibits extracellularly located channel activating proteases (CAPs), including prostasin, matriptase, and furin, the activities of which are observed at excessive levels at the apical surface of CF airway epithelial cells. QUB-TL1-mediated CAP inhibition results in diminished ENaC-mediated Na(+) absorption in CF airway epithelial cells caused by internalization of a prominent pool of cleaved (active) ENaCγ from the cell surface. Importantly, diminished ENaC activity correlates with improved airway hydration status and mucociliary clearance. We further demonstrate QUB-TL1-mediated furin inhibition, which is in contrast to other serine protease inhibitors (camostat mesylate and aprotinin), affords protection against neutrophil elastase-mediated ENaC activation and Pseudomonas aeruginosa exotoxin A-induced cell death. QUB-TL1 corrects aberrant CAP activities, providing a mechanism to delay or prevent the development of CF lung disease in a manner independent of CF transmembrane conductance regulator mutation.

5'-adenosine monophosphate mediated cooling treatment enhances ΔF508-Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) stability in vivo.

PubMed

Zhang, Yueqiang; O'Brien, William G; Zhao, Zhaoyang; Lee, Cheng Chi

2015-09-04

Gene mutations that produce misprocessed proteins are linked to many human disorders. Interestingly, some misprocessed proteins retained their biological function when stabilized by low temperature treatment of cultured cells in vitro. Here we investigate whether low temperature treatment in vivo can rescue misfolded proteins by applying 5'-AMP mediated whole body cooling to a Cystic Fibrosis (CF) mouse model carrying a mutant cystic fibrosis transmembrane conductance regulator (CFTR) with a deletion of the phenylalanine residue in position 508 (ΔF508-CFTR). Low temperature treatment of cultured cells was previously shown to be able to alleviate the processing defect of ΔF508-CFTR, enhancing its plasma membrane localization and its function in mediating chloride ion transport. Here, we report that whole body cooling enhanced the retention of ΔF508-CFTR in intestinal epithelial cells. Functional analysis based on β-adrenergic dependent salivary secretion and post-natal mortality rate revealed a moderate but significant improvement in treated compared with untreated CF mice. Our findings demonstrate that temperature sensitive processing of mutant proteins can be responsive to low temperature treatment in vivo.

Cystic Fibrosis: Brazilian ENT Experience

PubMed Central

Sih, Tania; Godinho, Ricardo; Franco, Leticia Paiva; Piltcher, Otávio

2012-01-01

Most published studies about Cystic Fibrosis (CF) are European or North American. There are still few publications about the characteristics of fibrocystic populations in developing countries. The incidence of cystic fibrosis (CF) in Brazil varies among different regions (1 : 10,000 in Minas Gerais, 1 : 9,500 in Paraná, 1 : 8,700 in Santa Catarina, and 1 : 1600 in Rio Grande do Sul). The prevalence of the DF508 mutation also varies according to population: 33% in Sao Paulo, 49% in Rio Grande do Sul, 27% in Santa Catarina, and 52% in Minas Gerais. Cough and nasal obstruction are the most common symptoms. The variation in nasal polyposis prevalence may be explained by population genotypic characteristics in a country that spans a continent. Findings on nasal endoscopy and computed tomography (CT) have better correlation than do this information compared with surgical and clinical history. Microbiologic studies suggest a high level of early contamination of the airways. Sensorineural hearing loss (SNHL) occurs in these patients as a result of ototoxic antibiotics. The data compiled in this paper is useful, but also lead to the general agreement that more research would be welcome due to the unique characteristics of this country. PMID:22611403

A statistical model to predict one-year risk of death in patients with cystic fibrosis.

PubMed

Aaron, Shawn D; Stephenson, Anne L; Cameron, Donald W; Whitmore, George A

2015-11-01

We constructed a statistical model to assess the risk of death for cystic fibrosis (CF) patients between scheduled annual clinical visits. Our model includes a CF health index that shows the influence of risk factors on CF chronic health and on the severity and frequency of CF exacerbations. Our study used Canadian CF registry data for 3,794 CF patients born after 1970. Data up to 2010 were analyzed, yielding 44,390 annual visit records. Our stochastic process model postulates that CF health between annual clinical visits is a superposition of chronic disease progression and an exacerbation shock stream. Death occurs when an exacerbation carries CF health across a critical threshold. The data constitute censored survival data, and hence, threshold regression was used to connect CF death to study covariates. Maximum likelihood estimates were used to determine which clinical covariates were included within the regression functions for both CF chronic health and CF exacerbations. Lung function, Pseudomonas aeruginosa infection, CF-related diabetes, weight deficiency, pancreatic insufficiency, and the deltaF508 homozygous mutation were significantly associated with CF chronic health status. Lung function, age, gender, age at CF diagnosis, P aeruginosa infection, body mass index <18.5, number of previous hospitalizations for CF exacerbations in the preceding year, and decline in forced expiratory volume in 1 second in the preceding year were significantly associated with CF exacerbations. When combined in one summative model, the regression functions for CF chronic health and CF exacerbation risk provided a simple clinical scoring tool for assessing 1-year risk of death for an individual CF patient. Goodness-of-fit tests of the model showed very encouraging results. We confirmed predictive validity of the model by comparing actual and estimated deaths in repeated hold-out samples from the data set and showed excellent agreement between estimated and actual mortality. Our threshold regression model incorporates a composite CF chronic health status index and an exacerbation risk index to produce an accurate clinical scoring tool for prediction of 1-year survival of CF patients. Our tool can be used by clinicians to decide on optimal timing for lung transplant referral. Copyright © 2015 Elsevier Inc. All rights reserved.

Lubiprostone ameliorates the cystic fibrosis mouse intestinal phenotype.

PubMed

De Lisle, Robert C; Mueller, Racquel; Roach, Eileen

2010-09-15

Cystic fibrosis (CF) is caused by mutations in the CFTR gene that impair the function of CFTR, a cAMP-regulated anion channel. In the small intestine loss of CFTR function creates a dehydrated, acidic luminal environment which is believed to cause an accumulation of mucus, a phenotype characteristic of CF. CF mice have small intestinal bacterial overgrowth, an altered innate immune response, and impaired intestinal transit. We investigated whether lubiprostone, which can activate the CLC2 Cl- channel, would improve the intestinal phenotype in CF mice. Cftr(tm1UNC) (CF) and wildtype (WT) littermate mice on the C57BL/6J background were used. Lubiprostone (10 μg/kg-day) was administered by gavage for two weeks. Mucus accumulation was estimated from crypt lumen widths in periodic acid-Schiff base, Alcian blue stained sections. Luminal bacterial load was measured by qPCR for the bacterial 16S gene. Gastric emptying and small intestinal transit in fasted mice were assessed using gavaged rhodamine dextran. Gene expression was evaluated by Affymetrix Mouse430 2.0 microarray and qRT-PCR. Crypt width in control CF mice was 700% that of WT mice (P < 0.001). Lubiprostone did not affect WT crypt width but, unexpectedly, increased CF crypt width 22% (P = 0.001). Lubiprostone increased bacterial load in WT mice to 490% of WT control levels (P = 0.008). Conversely, lubiprostone decreased bacterial overgrowth in CF mice by 60% (P = 0.005). Lubiprostone increased gastric emptying at 20 min postgavage in both WT (P < 0.001) and CF mice (P < 0.001). Lubiprostone enhanced small intestinal transit in WT mice (P = 0.024) but not in CF mice (P = 0.377). Among other innate immune markers, expression of mast cell genes was elevated 4-to 40-fold in the CF intestine as compared to WT, and lubiprostone treatment of CF mice decreased expression to WT control levels. These results indicate that lubiprostone has some benefits for the CF intestinal phenotype, especially on bacterial overgrowth and the innate immune response. The unexpected observation of increased mucus accumulation in the crypts of lubiprostone-treated CF mice suggests the possibility that lubiprostone increases mucus secretion.

Lubiprostone ameliorates the cystic fibrosis mouse intestinal phenotype

PubMed Central

2010-01-01

Background Cystic fibrosis (CF) is caused by mutations in the CFTR gene that impair the function of CFTR, a cAMP-regulated anion channel. In the small intestine loss of CFTR function creates a dehydrated, acidic luminal environment which is believed to cause an accumulation of mucus, a phenotype characteristic of CF. CF mice have small intestinal bacterial overgrowth, an altered innate immune response, and impaired intestinal transit. We investigated whether lubiprostone, which can activate the CLC2 Cl- channel, would improve the intestinal phenotype in CF mice. Methods Cftrtm1UNC (CF) and wildtype (WT) littermate mice on the C57BL/6J background were used. Lubiprostone (10 μg/kg-day) was administered by gavage for two weeks. Mucus accumulation was estimated from crypt lumen widths in periodic acid-Schiff base, Alcian blue stained sections. Luminal bacterial load was measured by qPCR for the bacterial 16S gene. Gastric emptying and small intestinal transit in fasted mice were assessed using gavaged rhodamine dextran. Gene expression was evaluated by Affymetrix Mouse430 2.0 microarray and qRT-PCR. Results Crypt width in control CF mice was 700% that of WT mice (P < 0.001). Lubiprostone did not affect WT crypt width but, unexpectedly, increased CF crypt width 22% (P = 0.001). Lubiprostone increased bacterial load in WT mice to 490% of WT control levels (P = 0.008). Conversely, lubiprostone decreased bacterial overgrowth in CF mice by 60% (P = 0.005). Lubiprostone increased gastric emptying at 20 min postgavage in both WT (P < 0.001) and CF mice (P < 0.001). Lubiprostone enhanced small intestinal transit in WT mice (P = 0.024) but not in CF mice (P = 0.377). Among other innate immune markers, expression of mast cell genes was elevated 4-to 40-fold in the CF intestine as compared to WT, and lubiprostone treatment of CF mice decreased expression to WT control levels. Conclusions These results indicate that lubiprostone has some benefits for the CF intestinal phenotype, especially on bacterial overgrowth and the innate immune response. The unexpected observation of increased mucus accumulation in the crypts of lubiprostone-treated CF mice suggests the possibility that lubiprostone increases mucus secretion. PMID:20843337

Progress in cystic fibrosis and the CF Therapeutics Development Network

PubMed Central

Rowe, Steven M; Borowitz, Drucy S; Burns, Jane L; Clancy, John P; Donaldson, Scott H; Retsch-Bogart, George; Sagel, Scott D; Ramsey, Bonnie W

2013-01-01

Cystic fibrosis (CF), the most common life-shortening genetic disorder in Caucasians, affects approximately 70 000 individuals worldwide. In 1998, the Cystic Fibrosis Foundation (CFF) launched the CF Therapeutics Development Network (CF-TDN) as a central element of its Therapeutics Development Programme. Designed to accelerate the clinical evaluation of new therapies needed to fulfil the CFF mission to control and cure CF, the CF-TDN has conducted 75 clinical trials since its inception, and has contributed to studies as varied as initial safety and proof of concept trials to pivotal programmes required for regulatory approval. This review highlights recent and significant research efforts of the CF-TDN, including a summary of contributions to studies involving CF transmembrane conductance regulator (CFTR) modulators, airway surface liquid hydrators and mucus modifiers, anti-infectives, anti-inflammatories, and nutritional therapies. Efforts to advance CF biomarkers, necessary to accelerate the therapeutic goals of the network, are also summarised. PMID:22960984

Progress in cystic fibrosis and the CF Therapeutics Development Network.

PubMed

Rowe, Steven M; Borowitz, Drucy S; Burns, Jane L; Clancy, John P; Donaldson, Scott H; Retsch-Bogart, George; Sagel, Scott D; Ramsey, Bonnie W

2012-10-01

Cystic fibrosis (CF), the most common life-shortening genetic disorder in Caucasians, affects approximately 70 000 individuals worldwide. In 1998, the Cystic Fibrosis Foundation (CFF) launched the CF Therapeutics Development Network (CF-TDN) as a central element of its Therapeutics Development Programme. Designed to accelerate the clinical evaluation of new therapies needed to fulfil the CFF mission to control and cure CF, the CF-TDN has conducted 75 clinical trials since its inception, and has contributed to studies as varied as initial safety and proof of concept trials to pivotal programmes required for regulatory approval. This review highlights recent and significant research efforts of the CF-TDN, including a summary of contributions to studies involving CF transmembrane conductance regulator (CFTR) modulators, airway surface liquid hydrators and mucus modifiers, anti-infectives, anti-inflammatories, and nutritional therapies. Efforts to advance CF biomarkers, necessary to accelerate the therapeutic goals of the network, are also summarised.

Non-invasive measurement of liver and pancreas fibrosis in patients with cystic fibrosis.

PubMed

Friedrich-Rust, Mireen; Schlueter, Nina; Smaczny, Christina; Eickmeier, Olaf; Rosewich, Martin; Feifel, Kirstin; Herrmann, Eva; Poynard, Thierry; Gleiber, Wolfgang; Lais, Christoph; Zielen, Stefan; Wagner, Thomas O F; Zeuzem, Stefan; Bojunga, Joerg

2013-09-01

Patients with cystic fibrosis (CF) have a relevant morbidity and mortality caused by CF-related liver-disease. While transient elastography (TE) is an established elastography method in hepatology centers, Acoustic-Radiation-Force-Impulse (ARFI)-Imaging is a novel ultrasound-based elastography method which is integrated in a conventional ultrasound-system. The aim of the present study was to evaluate the prevalence of liver-fibrosis in patients with CF using TE, ARFI-imaging and fibrosis blood tests. 106 patients with CF were prospectively included in the present study and received ARFI-imaging of the left and right liver-lobe, ARFI of the pancreas TE of the liver and laboratory evaluation. The prevalence of liver-fibrosis according to recently published best practice guidelines for CFLD was 22.6%. Prevalence of significant liver-fibrosis assessed by TE, ARFI-right-liver-lobe, ARFI-left-liver-lobe, Fibrotest, Fibrotest-corrected-by-haptoglobin was 17%, 24%, 40%, 7%, and 16%, respectively. The best agreement was found for TE, ARFI-right-liver-lobe and Fibrotest-corrected-by-haptoglobin. Patients with pancreatic-insufficiency had significantly lower pancreas-ARFI-values as compared to patients without. ARFI-imaging and TE seem to be promising non-invasive methods for detection of liver-fibrosis in patients with CF. Copyright © 2013 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Gastrointestinal pathology in juvenile and adult CFTR-knockout ferrets.

PubMed

Sun, Xingshen; Olivier, Alicia K; Yi, Yaling; Pope, Christopher E; Hayden, Hillary S; Liang, Bo; Sui, Hongshu; Zhou, Weihong; Hager, Kyle R; Zhang, Yulong; Liu, Xiaoming; Yan, Ziying; Fisher, John T; Keiser, Nicholas W; Song, Yi; Tyler, Scott R; Goeken, J Adam; Kinyon, Joann M; Radey, Matthew C; Fligg, Danielle; Wang, Xiaoyan; Xie, Weiliang; Lynch, Thomas J; Kaminsky, Paul M; Brittnacher, Mitchell J; Miller, Samuel I; Parekh, Kalpaj; Meyerholz, David K; Hoffman, Lucas R; Frana, Timothy; Stewart, Zoe A; Engelhardt, John F

2014-05-01

Cystic fibrosis (CF) is a multiorgan disease caused by loss of a functional cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel in many epithelia of the body. Here we report the pathology observed in the gastrointestinal organs of juvenile to adult CFTR-knockout ferrets. CF gastrointestinal manifestations included gastric ulceration, intestinal bacterial overgrowth with villous atrophy, and rectal prolapse. Metagenomic phylogenetic analysis of fecal microbiota by deep sequencing revealed considerable genotype-independent microbial diversity between animals, with the majority of taxa overlapping between CF and non-CF pairs. CF hepatic manifestations were variable, but included steatosis, necrosis, biliary hyperplasia, and biliary fibrosis. Gallbladder cystic mucosal hyperplasia was commonly found in 67% of CF animals. The majority of CF animals (85%) had pancreatic abnormalities, including extensive fibrosis, loss of exocrine pancreas, and islet disorganization. Interestingly, 2 of 13 CF animals retained predominantly normal pancreatic histology (84% to 94%) at time of death. Fecal elastase-1 levels from these CF animals were similar to non-CF controls, whereas all other CF animals evaluated were pancreatic insufficient (<2 μg elastase-1 per gram of feces). These findings suggest that genetic factors likely influence the extent of exocrine pancreas disease in CF ferrets and have implications for the etiology of pancreatic sufficiency in CF patients. In summary, these studies demonstrate that the CF ferret model develops gastrointestinal pathology similar to CF patients. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Expression and function of Anoctamin 1/TMEM16A calcium-activated chloride channels in airways of in vivo mouse models for cystic fibrosis research.

PubMed

Hahn, Anne; Salomon, Johanna J; Leitz, Dominik; Feigenbutz, Dennis; Korsch, Lisa; Lisewski, Ina; Schrimpf, Katrin; Millar-Büchner, Pamela; Mall, Marcus A; Frings, Stephan; Möhrlen, Frank

2018-06-02

Physiological processes of vital importance are often safeguarded by compensatory systems that substitute for primary processes in case these are damaged by gene mutation. Ca 2+ -dependent Cl - secretion in airway epithelial cells may provide such a compensatory mechanism for impaired Cl - secretion via cystic fibrosis transmembrane conductance regulator (CFTR) channels in cystic fibrosis (CF). Anoctamin 1 (ANO1) Ca 2+ -gated Cl - channels are known to contribute to calcium-dependent Cl - secretion in tracheal and bronchial epithelia. In the present study, two mouse models of CF were examined to assess a potential protective function of Ca 2+ -dependent Cl - secretion, a CFTR deletion model (cftr -/- ), and a CF pathology model that overexpresses the epithelial Na + channel β-subunit (βENaC), which is encoded by the Scnn1b gene, specifically in airway epithelia (Scnn1b-Tg). The expression levels of ANO1 were examined by mRNA and protein content, and the channel protein distribution between ciliated and non-ciliated epithelial cells was analyzed. Moreover, Ussing chamber experiments were conducted to compare Ca 2+ -dependent Cl - secretion between wild-type animals and the two mouse models. Our results demonstrate that CFTR and ANO1 channels were co-expressed with ENaC in non-ciliated cells of mouse tracheal and bronchial epithelia. Ciliated cells did not express these proteins. Despite co-localization of CFTR and ANO1 in the same cell type, cells in cftr -/- mice displayed no altered expression of ANO1. Similarly, ANO1 expression was unaffected by βENaC overexpression in the Scnn1b-Tg line. These results suggest that the CF-related environment in the two mouse models did not induce ANO1 overexpression as a compensatory system.

An unexpected effect of TNF-α on F508del-CFTR maturation and function

PubMed Central

Bitam, Sara; Urbach, Valérie; Sermet-Gaudelus, Isabelle; Hinzpeter, Alexandre; Edelman, Aleksander

2015-01-01

Cystic fibrosis (CF) is a multifactorial disease caused by mutations in the cystic fibrosis transmembrane conductance regulator gene ( CFTR), which encodes a cAMP-dependent Cl - channel. The most frequent mutation, F508del, leads to the synthesis of a prematurely degraded, otherwise partially functional protein. CFTR is expressed in many epithelia, with major consequences in the airways of patients with CF, characterized by both fluid transport abnormalities and persistent inflammatory responses. The relationship between the acute phase of inflammation and the expression of wild type (WT) CFTR or F508del-CFTR is poorly understood. The aim of the present study was to investigate this effect. The results show that 10 min exposure to TNF-alpha (0.5-50ng/ml) of F508del-CFTR-transfected HeLa cells and human bronchial cells expressing F508del-CFTR in primary culture (HBE) leads to the maturation of F508del-CFTR and induces CFTR chloride currents. The enhanced CFTR expression and function upon TNFα is sustained, in HBE cells, for at least 24 h. The underlying mechanism of action involves a protein kinase C (PKC) signaling pathway, and occurs through insertion of vesicles containing F508del-CFTR to the plasma membrane, with TNFα behaving as a corrector molecule. In conclusion, a novel and unexpected action of TNFα has been discovered and points to the importance of systematic studies on the roles of inflammatory mediators in the maturation of abnormally folded proteins in general and in the context of CF in particular. PMID:26594334

Cystic Fibrosis Heterozygote Resistance to Cholera Toxin in the Cystic Fibrosis Mouse Model

NASA Astrophysics Data System (ADS)

Gabriel, Sherif E.; Brigman, Kristen N.; Koller, Beverly H.; Boucher, Richard C.; Stutts, M. Jackson

1994-10-01

The effect of the number of cystic fibrosis (CF) alleles on cholera toxin (CT)-induced intestinal secretion was examined in the CF mouse model. CF mice that expressed no CF transmembrane conductance regulator (CFTR) protein did not secrete fluid in response to CT. Heterozygotes expressed 50 percent of the normal amount of CFTR protein in the intestinal epithelium and secreted 50 percent of the normal fluid and chloride ion in response to CT. This correlation between CFTR protein and CT-induced chloride ion and fluid secretion suggests that CF heterozygotes might possess a selective advantage of resistance to cholera.

Discovery of Clinically Approved Agents That Promote Suppression of Cystic Fibrosis Transmembrane Conductance Regulator Nonsense Mutations.

PubMed

Mutyam, Venkateshwar; Du, Ming; Xue, Xiaojiao; Keeling, Kim M; White, E Lucile; Bostwick, J Robert; Rasmussen, Lynn; Liu, Bo; Mazur, Marina; Hong, Jeong S; Falk Libby, Emily; Liang, Feng; Shang, Haibo; Mense, Martin; Suto, Mark J; Bedwell, David M; Rowe, Steven M

2016-11-01

Premature termination codons (PTCs) in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF). Several agents are known to suppress PTCs but are poorly efficacious or toxic. To determine whether there are clinically available agents that elicit translational readthrough and improve CFTR function sufficient to confer therapeutic benefit to patients with CF with PTCs. Two independent screens, firefly luciferase and CFTR-mediated transepithelial chloride conductance assay, were performed on a library of 1,600 clinically approved compounds using fisher rat thyroid cells stably transfected with stop codons. Select agents were further evaluated using secondary screening assays including short circuit current analysis on primary cells from patients with CF. In addition, the effect of CFTR modulators (ivacaftor) was tested in combination with the most efficacious agents. From the primary screen, 48 agents were selected as potentially active. Following confirmatory tests in the transepithelial chloride conductance assay and prioritizing agents based on favorable pharmacologic properties, eight agents were advanced for secondary screening. Ivacaftor significantly increased short circuit current following forskolin stimulation in cells treated with pyranoradine tetraphosphate, potassium p-aminobenzoate, and escin as compared with vehicle control. Escin, an herbal agent, consistently induced readthrough activity as demonstrated by enhanced CFTR expression and function in vitro. Clinically approved drugs identified as potential readthrough agents, in combination with ivacaftor, may induce nonsense suppression to restore therapeutic levels of CFTR function. One or more agents may be suitable to advance to human testing.

Mechanisms of CFTR Functional Variants That Impair Regulated Bicarbonate Permeation and Increase Risk for Pancreatitis but Not for Cystic Fibrosis

PubMed Central

Lewis, Michele D.; Park, Hyun Woo; Brand, Randall E.; Gelrud, Andres; Anderson, Michelle A.; Banks, Peter A.; Conwell, Darwin; Lawrence, Christopher; Romagnuolo, Joseph; Baillie, John; Alkaade, Samer; Cote, Gregory; Gardner, Timothy B.; Amann, Stephen T.; Slivka, Adam; Sandhu, Bimaljit; Aloe, Amy; Kienholz, Michelle L.; Yadav, Dhiraj; Barmada, M. Michael; Bahar, Ivet; Lee, Min Goo; Whitcomb, David C.

2014-01-01

CFTR is a dynamically regulated anion channel. Intracellular WNK1-SPAK activation causes CFTR to change permeability and conductance characteristics from a chloride-preferring to bicarbonate-preferring channel through unknown mechanisms. Two severe CFTR mutations (CFTRsev) cause complete loss of CFTR function and result in cystic fibrosis (CF), a severe genetic disorder affecting sweat glands, nasal sinuses, lungs, pancreas, liver, intestines, and male reproductive system. We hypothesize that those CFTR mutations that disrupt the WNK1-SPAK activation mechanisms cause a selective, bicarbonate defect in channel function (CFTRBD) affecting organs that utilize CFTR for bicarbonate secretion (e.g. the pancreas, nasal sinus, vas deferens) but do not cause typical CF. To understand the structural and functional requirements of the CFTR bicarbonate-preferring channel, we (a) screened 984 well-phenotyped pancreatitis cases for candidate CFTRBD mutations from among 81 previously described CFTR variants; (b) conducted electrophysiology studies on clones of variants found in pancreatitis but not CF; (c) computationally constructed a new, complete structural model of CFTR for molecular dynamics simulation of wild-type and mutant variants; and (d) tested the newly defined CFTRBD variants for disease in non-pancreas organs utilizing CFTR for bicarbonate secretion. Nine variants (CFTR R74Q, R75Q, R117H, R170H, L967S, L997F, D1152H, S1235R, and D1270N) not associated with typical CF were associated with pancreatitis (OR 1.5, p = 0.002). Clones expressed in HEK 293T cells had normal chloride but not bicarbonate permeability and conductance with WNK1-SPAK activation. Molecular dynamics simulations suggest physical restriction of the CFTR channel and altered dynamic channel regulation. Comparing pancreatitis patients and controls, CFTRBD increased risk for rhinosinusitis (OR 2.3, p<0.005) and male infertility (OR 395, p<<0.0001). WNK1-SPAK pathway-activated increases in CFTR bicarbonate permeability are altered by CFTRBD variants through multiple mechanisms. CFTRBD variants are associated with clinically significant disorders of the pancreas, sinuses, and male reproductive system. PMID:25033378

Mechanisms of CFTR functional variants that impair regulated bicarbonate permeation and increase risk for pancreatitis but not for cystic fibrosis.

PubMed

LaRusch, Jessica; Jung, Jinsei; General, Ignacio J; Lewis, Michele D; Park, Hyun Woo; Brand, Randall E; Gelrud, Andres; Anderson, Michelle A; Banks, Peter A; Conwell, Darwin; Lawrence, Christopher; Romagnuolo, Joseph; Baillie, John; Alkaade, Samer; Cote, Gregory; Gardner, Timothy B; Amann, Stephen T; Slivka, Adam; Sandhu, Bimaljit; Aloe, Amy; Kienholz, Michelle L; Yadav, Dhiraj; Barmada, M Michael; Bahar, Ivet; Lee, Min Goo; Whitcomb, David C

2014-07-01

CFTR is a dynamically regulated anion channel. Intracellular WNK1-SPAK activation causes CFTR to change permeability and conductance characteristics from a chloride-preferring to bicarbonate-preferring channel through unknown mechanisms. Two severe CFTR mutations (CFTRsev) cause complete loss of CFTR function and result in cystic fibrosis (CF), a severe genetic disorder affecting sweat glands, nasal sinuses, lungs, pancreas, liver, intestines, and male reproductive system. We hypothesize that those CFTR mutations that disrupt the WNK1-SPAK activation mechanisms cause a selective, bicarbonate defect in channel function (CFTRBD) affecting organs that utilize CFTR for bicarbonate secretion (e.g. the pancreas, nasal sinus, vas deferens) but do not cause typical CF. To understand the structural and functional requirements of the CFTR bicarbonate-preferring channel, we (a) screened 984 well-phenotyped pancreatitis cases for candidate CFTRBD mutations from among 81 previously described CFTR variants; (b) conducted electrophysiology studies on clones of variants found in pancreatitis but not CF; (c) computationally constructed a new, complete structural model of CFTR for molecular dynamics simulation of wild-type and mutant variants; and (d) tested the newly defined CFTRBD variants for disease in non-pancreas organs utilizing CFTR for bicarbonate secretion. Nine variants (CFTR R74Q, R75Q, R117H, R170H, L967S, L997F, D1152H, S1235R, and D1270N) not associated with typical CF were associated with pancreatitis (OR 1.5, p = 0.002). Clones expressed in HEK 293T cells had normal chloride but not bicarbonate permeability and conductance with WNK1-SPAK activation. Molecular dynamics simulations suggest physical restriction of the CFTR channel and altered dynamic channel regulation. Comparing pancreatitis patients and controls, CFTRBD increased risk for rhinosinusitis (OR 2.3, p<0.005) and male infertility (OR 395, p<0.0001). WNK1-SPAK pathway-activated increases in CFTR bicarbonate permeability are altered by CFTRBD variants through multiple mechanisms. CFTRBD variants are associated with clinically significant disorders of the pancreas, sinuses, and male reproductive system.

Elevated Mirc1/Mir17-92 cluster expression negatively regulates autophagy and CFTR (cystic fibrosis transmembrane conductance regulator) function in CF macrophages.

PubMed

Tazi, Mia F; Dakhlallah, Duaa A; Caution, Kyle; Gerber, Madelyn M; Chang, Sheng-Wei; Khalil, Hany; Kopp, Benjamin T; Ahmed, Amr E; Krause, Kathrin; Davis, Ian; Marsh, Clay; Lovett-Racke, Amy E; Schlesinger, Larry S; Cormet-Boyaka, Estelle; Amer, Amal O

2016-11-01

Cystic fibrosis (CF) is a fatal, genetic disorder that critically affects the lungs and is directly caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, resulting in defective CFTR function. Macroautophagy/autophagy is a highly regulated biological process that provides energy during periods of stress and starvation. Autophagy clears pathogens and dysfunctional protein aggregates within macrophages. However, this process is impaired in CF patients and CF mice, as their macrophages exhibit limited autophagy activity. The study of microRNAs (Mirs), and other noncoding RNAs, continues to offer new therapeutic targets. The objective of this study was to elucidate the role of Mirs in dysregulated autophagy-related genes in CF macrophages, and then target them to restore this host-defense function and improve CFTR channel function. We identified the Mirc1/Mir17-92 cluster as a potential negative regulator of autophagy as CF macrophages exhibit decreased autophagy protein expression and increased cluster expression when compared to wild-type (WT) counterparts. The absence or reduced expression of the cluster increases autophagy protein expression, suggesting the canonical inverse relationship between Mirc1/Mir17-92 and autophagy gene expression. An in silico study for targets of Mirs that comprise the cluster suggested that the majority of the Mirs target autophagy mRNAs. Those targets were validated by luciferase assays. Notably, the ability of macrophages expressing mutant F508del CFTR to transport halide through their membranes is compromised and can be restored by downregulation of these inherently elevated Mirs, via restoration of autophagy. In vivo, downregulation of Mir17 and Mir20a partially restored autophagy expression and hence improved the clearance of Burkholderia cenocepacia. Thus, these data advance our understanding of mechanisms underlying the pathobiology of CF and provide a new therapeutic platform for restoring CFTR function and autophagy in patients with CF.

CF-related diabetes: Containing the metabolic miscreant of cystic fibrosis.

PubMed

Moheet, Amir; Moran, Antoinette

2017-11-01

Cystic fibrosis-related diabetes (CFRD) is associated with both an increase in morbidity and mortality in people with cystic fibrosis (CF). With increased screening and improved life expectancy of people with CF, the prevalence of CFRD is expected to rise further. The underlying pathophysiological mechanisms causing glucose intolerance and diabetes in patients with CF are not well understood but both functional and structural abnormalities in islet cells are likely to have key roles. Insulin therapy improves health outcomes in patients with CF. Future research is needed to better understand the mechanisms underlying the development of CFRD and to develop new screening and treatment strategies to minimize the detrimental impact of CFRD on health outcomes in people with CF. © 2017 Wiley Periodicals, Inc.

Comparative processing and function of human and ferret cystic fibrosis transmembrane conductance regulator.

PubMed

Fisher, John T; Liu, Xiaoming; Yan, Ziying; Luo, Meihui; Zhang, Yulong; Zhou, Weihong; Lee, Ben J; Song, Yi; Guo, Chenhong; Wang, Yujiong; Lukacs, Gergely L; Engelhardt, John F

2012-06-22

The most common cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation is ΔF508, and this causes cystic fibrosis (CF). New CF models in the pig and ferret have been generated that develop lung, pancreatic, liver, and intestinal pathologies that reflect disease in CF patients. Species-specific biology in the processing of CFTR has demonstrated that pig and mouse ΔF508-CFTR proteins are more effectively processed to the apical membrane of airway epithelia than human ΔF508-CFTR. The processing behavior of ferret WT- and ΔF508-CFTR proteins remains unknown, and such information is important to predicting the utility of a ΔF508-CFTR ferret. To this end, we sought to compare processing, membrane stability, and function of human and ferret WT- and ΔF508-CFTR proteins in a heterologous expression system using HT1080, HEK293T, BHK21, and Cos7 cells as well as human and ferret CF polarized airway epithelia. Analysis of the protein processing and stability by metabolic pulse-chase and surface On-Cell Western blots revealed that WT-fCFTR half-life and membrane stability were increased relative to WT-hCFTR. Furthermore, in BHK21, Cos7, and CuFi cells, human and ferret ΔF508-CFTR processing was negligible, whereas low levels of processing of ΔF508-fCFTR could be seen in HT1080 and HEK293T cells. Only the WT-fCFTR, but not ΔF508-fCFTR, produced functional cAMP-inducible chloride currents in both CF human and ferret airway epithelia. Further elucidation of the mechanism responsible for elevated fCFTR protein stability may lead to new therapeutic approaches to augment CFTR function. These findings also suggest that generation of a ferret CFTR(ΔF508/ΔF508) animal model may be useful.

Comparative Processing and Function of Human and Ferret Cystic Fibrosis Transmembrane Conductance Regulator*

PubMed Central

Fisher, John T.; Liu, Xiaoming; Yan, Ziying; Luo, Meihui; Zhang, Yulong; Zhou, Weihong; Lee, Ben J.; Song, Yi; Guo, Chenhong; Wang, Yujiong; Lukacs, Gergely L.; Engelhardt, John F.

2012-01-01

The most common cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation is ΔF508, and this causes cystic fibrosis (CF). New CF models in the pig and ferret have been generated that develop lung, pancreatic, liver, and intestinal pathologies that reflect disease in CF patients. Species-specific biology in the processing of CFTR has demonstrated that pig and mouse ΔF508-CFTR proteins are more effectively processed to the apical membrane of airway epithelia than human ΔF508-CFTR. The processing behavior of ferret WT- and ΔF508-CFTR proteins remains unknown, and such information is important to predicting the utility of a ΔF508-CFTR ferret. To this end, we sought to compare processing, membrane stability, and function of human and ferret WT- and ΔF508-CFTR proteins in a heterologous expression system using HT1080, HEK293T, BHK21, and Cos7 cells as well as human and ferret CF polarized airway epithelia. Analysis of the protein processing and stability by metabolic pulse-chase and surface On-Cell Western blots revealed that WT-fCFTR half-life and membrane stability were increased relative to WT-hCFTR. Furthermore, in BHK21, Cos7, and CuFi cells, human and ferret ΔF508-CFTR processing was negligible, whereas low levels of processing of ΔF508-fCFTR could be seen in HT1080 and HEK293T cells. Only the WT-fCFTR, but not ΔF508-fCFTR, produced functional cAMP-inducible chloride currents in both CF human and ferret airway epithelia. Further elucidation of the mechanism responsible for elevated fCFTR protein stability may lead to new therapeutic approaches to augment CFTR function. These findings also suggest that generation of a ferret CFTRΔF508/ΔF508 animal model may be useful. PMID:22570484

Novel methods to enhance single strand conformation polymorphism (SSCP) senstivity and efficiency: Application to mutation detection in cystic fibrosis (CF)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hagstrom, D.J.; Snow, K.; Yuan, Z.

1994-09-01

For single gene defects in which there are a variety of mutations with significant frequencies, it is a challenge to find an efficient and sensitive method for mutation detection. For example, although 70% to 75% of CF chromosomes in a North American Caucasian population have the mutation {delta}F508, more than 400 mutations (mostly single base pair substitutions) are represented on the remaining chromosomes. SSCP analysis is a relatively straightforward procedure and therefore suitable for routine use in a clinical laboratory. However, previous reports have demonstrated suboptimal sensitivity rates in screening for mutations. We have developed a novel set of conditionsmore » which greatly enhances sensitivity and efficiency of SSCP. Our protocol incorporates multiplex PCR, stepping of wattages during electrophoresis and increased salt concentration at the anode relative to the gel. To screen for mutations in the CFTR gene, three multiplex PCR reactions are performed using identical thermocycler parameters. Sizes of PCR products range from 441 bp to 196 bp: size differences of > 30 bp are necessary to ensure separation during electrophoresis. All PCR products are separated by electrophoresis at room temperature on a single gel containing 8% (37.5:1) polyacrylamide, 5% glycerol and 1x TBE. Using an anode buffer with increased salt (2x TBE) sharpens smaller sized bands, and stepping watts from 5W to 20W during electrophoresis enhances sensitivity. Positive controls were used to demonstrate that mutations could be detected. Other mutations or polymorphisms were verified by cycle sequencing of PCR products or by alternative PCR-based assays for the more common mutations. Thus, using 3 PCR reactions per patient and one gel condition, we are able to achieve a CF mutation detection rate of approximately 90% in a North American Caucasian population.« less

Diagnosis and Treatment of Endocrine Co-Morbidities in Patients with Cystic Fibrosis

PubMed Central

Siwamogsatham, Oranan; Alvarez, Jessica

2015-01-01

Purpose of review The aim of this review is to provide an update on various relevant endocrine aspects of care in adolescents and adults with cystic fibrosis (CF). Recent findings As life expectancy in CF has continuously improved, endocrine complications have become more apparent. The common endocrine complications include cystic fibrosis related diabetes (CFRD), cystic fibrosis related bone disease, vitamin D deficiency and poor growth and pubertal development. Thyroid and adrenal disorders have also been reported, although the prevalence appears to be less common. Summary Endocrine diseases are an increasingly recognized complication that has a significant impact on the overall health of individuals with CF. This review summarizes the updated screening and management of endocrine diseases in the CF population. PMID:25105995

Small RNA and transcriptome sequencing reveal the role of miR-199a-3p in inflammatory processes in cystic fibrosis airways.

PubMed

Bardin, Pauline; Marchal-Duval, Emmeline; Sonneville, Florence; Blouquit-Laye, Sabine; Rousselet, Nathalie; Le Rouzic, Philippe; Corvol, Harriet; Tabary, Olivier

2018-05-07

Cystic fibrosis (CF) is the most common lethal genetic disease, caused by CFTR (cystic fibrosis transmembrane conductance regulator) gene mutations. CF is characterized by an ionic imbalance and thickened mucus, which impair mucociliary clearance, promote bacterial colonization, and the establishment of infection/inflammation cycles. However, the origin of this inflammation remains unclear, although microRNA (miRNA) are suspected to be involved. MiRNA are small non-coding RNA that bind to the 3'-untranslated regions (UTR) of target gene mRNA, thereby repressing their translation and/or inducing their degradation. The goal of this study was to investigate the role of microRNA associated with pulmonary inflammation in CF patients. Through the analysis of all miRNA (miRNome) in human primary air-liquid interface cultures, we demonstrated that miR-199a-3p is the only miRNA downregulated in CF patients compared to controls. Moreover, through RNA sequencing (transcriptome) analysis, we showed that 50% of all deregulated mRNA are linked directly or indirectly to the NF-κB pathway. To identify a specific target, we used bioinformatics analysis to predict whether miR-199a-3p targets the 3'-UTR of IKBKB which encodes IKKβ, a major protein in the NF-κB pathway. Subsequently, we used bronchial explants from CF patients to show that miR-199a-3p expression is downregulated compared to controls and inversely correlated with increases in expression of IKKβ and IL-8. Through functional studies, we showed that miR-199a-3p modulates the expression of IKBKB through a direct interaction at its 3'-UTR in bronchial epithelial cells from CF patients. In miR-199a-3p overexpression experiments, we demonstrated that for CF cells miR-199a-3p reduced IKKβ protein expression, NF-κB activity, and IL-8 secretion. Taken together, our findings show that miR-199a-3p plays a negative regulatory role in the NF-κB signalling pathway and that its low expression in CF patients contributes to chronic pulmonary inflammation. This article is protected by copyright. All rights reserved.

The porcine lung as a potential model for cystic fibrosis

PubMed Central

Rogers, Christopher S.; Abraham, William M.; Brogden, Kim A.; Engelhardt, John F.; Fisher, John T.; McCray, Paul B.; McLennan, Geoffrey; Meyerholz, David K.; Namati, Eman; Ostedgaard, Lynda S.; Prather, Randall S.; Sabater, Juan R.; Stoltz, David Anthony; Zabner, Joseph; Welsh, Michael J.

2008-01-01

Airway disease currently causes most of the morbidity and mortality in patients with cystic fibrosis (CF). However, understanding the pathogenesis of CF lung disease and developing novel therapeutic strategies have been hampered by the limitations of current models. Although the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) has been targeted in mice, CF mice fail to develop lung or pancreatic disease like that in humans. In many respects, the anatomy, biochemistry, physiology, size, and genetics of pigs resemble those of humans. Thus pigs with a targeted CFTR gene might provide a good model for CF. Here, we review aspects of porcine airways and lung that are relevant to CF. PMID:18487356

Sensitivity of chloride efflux vs. transepithelial measurements in mixed CF and normal airway epithelial cell populations.

PubMed

Illek, Beate; Lei, Dachuan; Fischer, Horst; Gruenert, Dieter C

2010-01-01

While the Cl(-) efflux assays are relatively straightforward, their ability to assess the efficacy of phenotypic correction in cystic fibrosis (CF) tissue or cells may be limited. Accurate assessment of therapeutic efficacy, i.e., correlating wild type CF transmembrane conductance regulator (CFTR) levels with phenotypic correction in tissue or individual cells, requires a sensitive assay. Radioactive chloride ((36)Cl) efflux was compared to Ussing chamber analysis for measuring cAMP-dependent Cl(-) transport in mixtures of human normal (16HBE14o-) and cystic fibrosis (CF) (CFTE29o- or CFBE41o-, respectively) airway epithelial cells. Cell mixtures with decreasing amounts of 16HBE14o- cells were evaluated. Efflux and Ussing chamber studies on mixed populations of normal and CF airway epithelial cells showed that, as the number of CF cells within the population was progressively increased, the cAMP-dependent Cl(-) decreased. The (36)Cl efflux assay was effective for measuring Cl(-) transport when ≥ 25% of the cells were normal. If < 25% of the cells were phenotypically wild-type (wt), the (36)Cl efflux assay was no longer reliable. Polarized CFBE41o- cells, also homozygous for the ΔF508 mutation, were used in the Ussing chamber studies. Ussing analysis detected cAMP-dependent Cl(-) currents in mixtures with ≥1% wild-type cells indicating that Ussing analysis is more sensitive than (36)Cl efflux analysis for detection of functional CFTR. Assessment of CFTR function by Ussing analysis is more sensitive than (36)Cl efflux analysis. Ussing analysis indicates that cell mixtures containing 10% 16HBE14o- cells showed 40-50% of normal cAMP-dependent Cl(-) transport that drops off exponentially between 10-1% wild-type cells. Copyright © 2010 S. Karger AG, Basel.

Heritability of Lung Disease Severity in Cystic Fibrosis

PubMed Central

Vanscoy, Lori L.; Blackman, Scott M.; Collaco, Joseph M.; Bowers, Amanda; Lai, Teresa; Naughton, Kathleen; Algire, Marilyn; McWilliams, Rita; Beck, Suzanne; Hoover-Fong, Julie; Hamosh, Ada; Cutler, Dave; Cutting, Garry R.

2007-01-01

Rationale: Obstructive lung disease, the major cause of mortality in cystic fibrosis (CF), is poorly correlated with mutations in the disease-causing gene, indicating that other factors determine severity of lung disease. Objectives: To quantify the contribution of modifier genes to variation in CF lung disease severity. Methods: Pulmonary function data from patients with CF living with their affected twin or sibling were converted into reference values based on both healthy and CF populations. The best measure of FEV1 within the last year was used for cross-sectional analysis. FEV1 measures collected over at least 4 years were used for longitudinal analysis. Genetic contribution to disease variation (i.e., heritability) was estimated in two ways: by comparing similarity of lung function in monozygous (MZ) twins (∼ 100% gene sharing) with that of dizygous (DZ) twins/siblings (∼ 50% gene sharing), and by comparing similarity of lung function measures for related siblings to similarity for all study subjects. Measurements and Main Results: Forty-seven MZ twin pairs, 10 DZ twin pairs, and 231 sibling pairs (of a total of 526 patients) with CF were studied. Correlations for all measures of lung function for MZ twins (0.82–0.91, p < 0.0001) were higher than for DZ twins and siblings (0.50–0.64, p < 0.001). Heritability estimates from both methods were consistent for each measure of lung function and ranged from 0.54 to 1.0. Heritability estimates generally increased after adjustment for differences in nutritional status (measured as body mass index z-score). Conclusions: Our heritability estimates indicate substantial genetic control of variation in CF lung disease severity, independent of CFTR genotype. PMID:17332481

Iron-Regulated Expression of Alginate Production, Mucoid Phenotype, and Biofilm Formation by Pseudomonas aeruginosa

PubMed Central

Wiens, Jacinta R.; Vasil, Adriana I.; Schurr, Michael J.; Vasil, Michael L.

2014-01-01

ABSTRACT Pseudomonas aeruginosa strains of non-cystic fibrosis (non-CF) origin do not produce significant amounts of extracellular alginate and are nonmucoid. In CF, such isolates can become mucoid through mutation of one of the genes (mucA, mucB, mucC, or mucD) that produce regulatory factors that sequester AlgU, required for increased expression of alginate genes. Mutation of the muc genes in the nonmucoid PAO1, PA14, PAKS-1, and Ps388 strains led to increased levels of extracellular alginate and an obvious mucoid phenotype, but only under iron-limiting growth conditions (≤5 µM), not under iron-replete conditions (≥10 µM). In contrast, >50% of P. aeruginosa isolates from chronic CF pulmonary infections expressed increased levels of alginate and mucoidy both under iron-limiting and iron-replete conditions (i.e., iron-constitutive phenotype). No single iron regulatory factor (e.g., Fur, PvdS) was associated with this loss of iron-regulated alginate expression and mucoidy in these CF isolates. However, the loss of only pyoverdine production, or its uptake, abrogated the ability of P. aeruginosa to produce a robust biofilm that represents the Psl-type of biofilm. In contrast, we show that mutation of the pyoverdine and pyochelin biosynthesis genes and the pyoverdine receptor (FpvA) lead to iron-constitutive expression of the key alginate biosynthesis gene, algD, and an explicitly mucoid phenotype in both iron-limiting and iron-replete conditions. These data indicate that alginate production and mucoidy, in contrast to other types of biofilms produced by P. aeruginosa, are substantially enhanced under iron limitation. These results also have compelling implications in relation to the use of iron chelators in the treatment of P. aeruginosa CF infections. PMID:24496793

Improving test properties for neonatal cystic fibrosis screening in the Netherlands before the nationwide start by May 1st 2011.

PubMed

Cornel, Martina C; Gille, Johan J P; Loeber, J Gerard; Vernooij-van Langen, Annette M M; Dankert-Roelse, Jeannette; Bolhuis, Piet A

2012-07-01

When new technical possibilities arise in health care, often attunement is needed between different actors from the perspectives of research, health care providers, patients, ethics and policy. For cystic fibrosis (CF) such a process of attunement in the Netherlands started in a committee of the Health Council on neonatal screening in 2005. In the balancing of pros and cons according to Wilson and Jungner criteria, the advantages for the CF patient were considered clear, even though CF remains a severe health problem with treatment. Nevertheless, screening was not started then, mainly since the specificity of the tests available at that time was considered too low. Many healthy infants would have been referred for sweat testing and much uncertainty would arise in their parents. Also the limited sensitivity for immigrants and the detection of less severe phenotypes and carriers were considered problematic. The Health Council recommended a pilot screening project which was subsequently performed in some provinces, leading to a 4-step protocol: IRT, PAP, screening for a CFTR mutation panel, and sequencing of the CFTR gene. This would lead to the identification of 23 cases of classical CF, two infants with less severe forms and 12 carriers per year in the Netherlands. Thus many CF patients can be diagnosed early, while limiting the number of referrals, the number of infants with less severe forms diagnosed and the number of carriers identified. Technical solutions were found to limit the ethical problems. A nationwide program using this four step protocol started by 1 May 2011.

Chromosomal mechanisms of aminoglycoside resistance in Pseudomonas aeruginosa isolates from cystic fibrosis patients.

PubMed

Islam, S; Oh, H; Jalal, S; Karpati, F; Ciofu, O; Høiby, N; Wretlind, B

2009-01-01

In total, 40 Pseudomonas aeruginosa isolates from cystic fibrosis (CF) patients were included in this study. Twenty of these were collected in 1994 and 1997, from six CF patients, and the rest were collected from different CF patients in 2000 and 2001. The relative expression of mRNA for the efflux pump protein MexY was determined by real-time PCR and correlated with susceptibilities to amikacin and tobramycin. The chromosomal genes mexZ, rplY, galU, PA5471 and nuoG, which were found to have a role in the gradual increase in MICs of aminoglycoside antibiotics in laboratory mutants of P. aeruginosa, were analysed. MexY mRNA overproduction was found in 17/20 isolates collected in 1994 and 1997, and was correlated with decreased susceptibility to aminoglycosides. Alteration of the MexXY-OprM efflux system has been the main mechanism of resistance to aminoglycoside antibiotics in CF P. aeruginosa isolates over the 3-year period. In several isolates, expression of the PA5471 gene product might have some effect on elevated MICs of aminoglycosides. Inactivation of rplY, galU and/or nuoG may explain the gradual increase in MICs of aminoglycosides in laboratory mutants but probably not in the CF environment, as rplY and galU were unaltered in all isolates, and nuoG was not expressed in only one isolate. No 16S rRNA A-site mutations were found in any of the four copies of the gene in 13 investigated isolates.

Pseudo-bartter syndrome, pattern and correlation with other cystic fibrosis features.

PubMed

Dahabreh, Muna M; Najada, Abdelhamid S

2013-03-01

Pseudo-Bartter Syndrome (PBS), although quite common in patients with cystic fibrosis (CF), is often missed as simple dehydration or Bartter syndrome. This study was performed in patients with PBS to compare the pattern and course of the disease with those with CF not manifesting with this syndrome. All patients with CF who attended the respiratory clinic at Queen Rania Al-Abdallah Hospital from January 2000 to April 2010 were included in this retrospective case-control study. A specially formulated data sheet was used and those with PBS and those not having the syndrome were identified. A total of 110 patients (51% female) with CF with a median age of seven years were followed-up. Eighteen (16.3%) of them had one or more episodes of PBS. The median follow-up period was 6.2 years. All the episodes occurred during summer and in infancy. Median age of the initial episode of PBS was three months. One-third of them were initially followed at the nephrology clinic. Three patterns of PBS were identified: single episode in three (16.6%) patients, recurrent in 12 (66.6%) patients and chronic in three (16.6%) patients. Early colonization of Pseudomonas spp before 1 st birthday was seen in 44% patients with PBS compared with 12% in other CF patients (P-value = 0.0075). The total number of colonized patients and other CF features at the time of the study did not differ significantly among patients, although the mean Shwachman-Kulczycki score is significantly lower in those with recurrent PBS (69 compared with 85 in other CF patients). Gene mutation was identified in only 30% of the entire cohort. PBS is common in patients with CF, and it should be kept in mind in any patient with hypotonic dehydration and metabolic alkalosis. Recurrent pattern is associated with earlier Pseudomonas colonization.

The AREST CF experience in biobanking - More than just tissues, tubes and time.

PubMed

Garratt, Luke W; Kicic, Anthony; Robertson, Colin; Ranganathan, Sarath; Sly, Peter D; Stick, Stephen M

2017-09-01

Research to further improve outcomes for people with CF is dependent upon well characterised, archived and accessible clinical specimens. The recent article by Beekman et al. published in Journal of Cystic Fibrosis summarised a scientific meeting at the 13th ECFS Basic Science Conference. This meeting discussed how well-annotated, clinical biobanks for CF could be established in Europe to meet the needs of therapeutic development. The Australian Respiratory Early Surveillance Team for Cystic Fibrosis (AREST CF) has conducted biobanking of CF research and clinical specimens since the late 1990s and is custodian of the most comprehensive paediatric CF biobank in the world that focuses on the first years of life. This short communication will describe the approach undertaken by AREST CF in establishing a clinical specimen biobank. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Variability of sweat chloride concentration in subjects with cystic fibrosis and G551D mutations.

PubMed

Vermeulen, F; Le Camus, C; Davies, J C; Bilton, D; Milenković, D; De Boeck, K

2017-01-01

Sweat chloride concentration, a biomarker of CFTR function, is an appropriate outcome parameter in clinical trials aimed at correcting the basic CF defect. Although there is consensus on a cut-off value to diagnose CF, we have only limited information on the within subject variability of sweat chloride over time. Such information would be useful for sample size calculations in clinical trials. Therefore, we retrospectively analyzed repeated sweat chloride values obtained in patients with G551D mutation(s) assigned to placebo in an ivacaftor interventional trial. In subjects with G551D at least 12years of age, a pilocarpine sweat test using Macroduct collector was taken on both arms at 8 time points over 48weeks. We explored 1062 pilocarpine sweat test values obtained in 78 placebo patients of the VX08-770-102 trial. Mean overall sweat chloride value (all patients, all tests, n=1062) was 100.8mmol/L (SD 12.7mmol/L). Using a multilevel mixed model, the between-subject standard deviation (SD) for sweat chloride was 8.9mmol/L (95% CI 7.4-10.6) and within-subject SD was 8.1mmol/L (95% CI 7.5-8.7). Limits of repeatability for repeat measurements were -19.7 to +21.6mmol/L using values from one arm, and -13.3 to 11.8mmol/L using mean of values obtained at 4 test occasions. Sample size calculations showed that the minimal treatment effect on sweat chloride concentration that can be demonstrated for a group of 5 patients is around 15mmol/L, using a cross-over design and combinations of 4 tests for each phase of the trial. Although the sweat test is considered a robust measure, sweat chloride measurements in patients with CF and a G551D mutation had an inherent biological variability that is higher than commonly considered. Further analyses of placebo group data are crucial to learn more about the natural variability of this outcome parameter. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

TALEN-mediated generation and genetic correction of disease-specific human induced pluripotent stem cells.

PubMed

Ramalingam, Sivaprakash; Annaluru, Narayana; Kandavelou, Karthikeyan; Chandrasegaran, Srinivasan

2014-01-01

Generation and precise genetic correction of patient-derived hiPSCs have great potential in regenerative medicine. Such targeted genetic manipulations can now be achieved using gene-editing nucleases. Here, we report generation of cystic fibrosis (CF) and Gaucher's disease (GD) hiPSCs respectively from CF (homozygous for CFTRΔF508 mutation) and Type II GD [homozygous for β-glucocerebrosidase (GBA) 1448T>C mutation] patient fibroblasts, using CCR5- specific TALENs. Site-specific addition of loxP-flanked Oct4/Sox2/Klf4/Lin28/Nanog/eGFP gene cassette at the endogenous CCR5 site of patient-derived disease-specific primary fibroblasts induced reprogramming, giving rise to both monoallele (heterozygous) and biallele CCR5-modified hiPSCs. Subsequent excision of the donor cassette was done by treating CCR5-modified CF and GD hiPSCs with Cre. We also demonstrate site-specific correction of sickle cell disease (SCD) mutations at the endogenous HBB locus of patient-specific hiPSCs [TNC1 line that is homozygous for mutated β- globin alleles (βS/βS)], using HBB-specific TALENs. SCD-corrected hiPSC lines showed gene conversion of the mutated βS to the wild-type βA in one of the HBB alleles, while the other allele remained a mutant phenotype. After excision of the loxP-flanked DNA cassette from the SCD-corrected hiPSC lines using Cre, we obtained secondary heterozygous βS/βA hiPSCs, which express the wild-type (βA) transcript to 30-40% level as compared to uncorrected (βS/βS) SCD hiPSCs when differentiated into erythroid cells. Furthermore, we also show that TALEN-mediated generation and genetic correction of disease-specific hiPSCs did not induce any off-target mutations at closely related sites.

SERS detection of the biomarker hydrogen cyanide from Pseudomonas aeruginosa cultures isolated from cystic fibrosis patients

NASA Astrophysics Data System (ADS)

Lauridsen, Rikke Kragh; Sommer, Lea M.; Johansen, Helle Krogh; Rindzevicius, Tomas; Molin, Søren; Jelsbak, Lars; Engelsen, Søren Balling; Boisen, Anja

2017-03-01

Pseudomonas aeruginosa is the primary cause of chronic airway infections in cystic fibrosis (CF) patients. Persistent infections are seen from the first P. aeruginosa culture in about 75% of young CF patients, and it is important to discover new ways to detect P. aeruginosa at an earlier stage. The P. aeruginosa biomarker hydrogen cyanide (HCN) contains a triple bond, which is utilized in this study because of the resulting characteristic C≡N peak at 2135 cm-1 in a Raman spectrum. The Raman signal was enhanced by surface-enhanced Raman spectroscopy (SERS) on a Au-coated SERS substrate. After long-term infection, a mutation in the patho-adaptive lasR gene can alter the expression of HCN, which is why it is sometimes not possible to detect HCN in the breath of chronically infected patients. Four P. aeruginosa reference strains and 12 clinical P. aeruginosa strains isolated from CF children were evaluated, and HCN was clearly detected from overnight cultures of all wild type-like isolates and half of the later isolates from the same patients. The clinical impact could be that P. aeruginosa infections could be detected at an earlier stage, because daily breath sampling with an immediate output could be possible with a point-of-care SERS device.

Host-pathogen interplay in the respiratory environment of cystic fibrosis.

PubMed

Yonker, Lael M; Cigana, Cristina; Hurley, Bryan P; Bragonzi, Alessandra

2015-07-01

Significant advances have been made in the understanding of disease progression in cystic fibrosis (CF), revealing a complex interplay between host and pathogenic organisms. The diverse CF microbiota within the airway activates an aberrant immune response that is ineffective in clearing infection. An appreciation of how the CF host immune system interacts with these organisms is crucial to understanding the pathogenesis of CF pulmonary disease. Here we discuss the microbial complexity present in the lungs of individuals with CF, review emerging concepts of innate and adaptive immune responses to pathogens that chronically inhabit the CF lung, and discuss therapies that target the aberrant inflammatory response that characterizes CF. A greater understanding of the underlying mechanisms will shed light on pathogenesis and guide more targeted therapies in the future that serve to reduce infection, minimize lung pathology, and improve the quality of life for patients with CF. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Pharmacological treatment of the ion transport defect in cystic fibrosis.

PubMed

Roomans, G M

2001-01-01

Cystic fibrosis (CF) is a lethal monogenetic disease characterised by impaired water and ion transport over epithelia. The lung pathology is fatal and causes death in 95% of CF patients. The genetic basis of the disease is a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-regulated chloride channel. The most common mutation, DeltaF508, results in a protein that cannot properly be folded in the endoplasmic reticulum, is destroyed and hence does not reach the apical cell membrane. This paper will discuss those pharmacological approaches that are directed at correcting the defect in ion transport. At present, no clinically effective drug is available, although research has defined areas in which progress might be made. These are the following: (1) the drug 4-phenylbutyrate (4PBA) increases the expression of DeltaF508-CFTR in the cell membrane, probably by breaking the association between DeltaF508-CFTR and a chaperone; (2) a number of xanthines, in particular 8-cyclopentyl-1, 3-dipropylxanthine (CPX), are effective in activating CFTR, presumably by direct binding and also possibly by correcting the trafficking defect; (3) the isoflavone genistein can activate both wild-type and mutant CFTR, probably through direct binding to the channel; (4) purinergic agonists (ATP and UTP) can stimulate chloride secretion via a Ca(2+)-dependent chloride channel and in this way compensate for the defect in CFTR, but stable analogues will be required before this type of treatment has clinical significance; (5) treatment with inhaled amiloride may correct the excessive absorption of Na(+) ions and water by airway epithelial cells that appears connected to the defect in CFTR; although clinical tests have not been very successful so far, amiloride analogues with a longer half-life may give better results. The role of CFTR in bicarbonate secretion has not yet been established with certainty, but correction of the defect in bicarbonate secretion may be important in clinical treatment of the disease. Currently, major efforts are directed at developing a pharmacological treatment of the ion transport defect in CF, but much basic research remains to be done, in particular, with regard to the mechanism by which defective CFTR is removed in the endoplasmic reticulum by the ubiquitin-proteasome pathway, which is a central pathway in protein production and of significance for several other diseases apart from CF.

Agricultural use of Burkholderia (Pseudomonas) cepacia: a threat to human health?

PubMed Central

Holmes, A.; Govan, J.; Goldstein, R.

1998-01-01

In the past 2 decades, Burkholderia cepacia has emerged as a human pathogen causing numerous outbreaks, particularly among cystic fibrosis (CF) patients. One highly transmissible strain has spread across North America and Britain, and another between hospitalized CF and non-CF patients. Meanwhile, the organism has been developed as a biopesticide for protecting crops against fungal diseases and has potential as a bioremediation agent for breaking down recalcitrant herbicides and pesticides. However, B. cepacia is inherently resistant to multiple antibiotics; selection of strains "safe" for environmental application is not at present possible phenotypically or genotypically; molecular epidemiology and phylogenetic studies demonstrate that highly transmissible strains emerge randomly; and the organism has a capacity for rapid mutation and adaptation (facilitated by numerous insertion sequences), and a large, complex genome divided into separate chromosomes. Therefore, the widespread agricultural use of B. cepacia should be approached with caution. PMID:9621192

Neutrophil Membrane Cholesterol Content is a Key Factor in Cystic Fibrosis Lung Disease.

PubMed

White, Michelle M; Geraghty, Patrick; Hayes, Elaine; Cox, Stephen; Leitch, William; Alfawaz, Bader; Lavelle, Gillian M; McElvaney, Oliver J; Flannery, Ryan; Keenan, Joanne; Meleady, Paula; Henry, Michael; Clynes, Martin; Gunaratnam, Cedric; McElvaney, Noel G; Reeves, Emer P

2017-09-01

Identification of mechanisms promoting neutrophil trafficking to the lungs of patients with cystic fibrosis (CF) is a challenge for next generation therapeutics. Cholesterol, a structural component of neutrophil plasma membranes influences cell adhesion, a key step in transmigration. The effect of chronic inflammation on neutrophil membrane cholesterol content in patients with CF (PWCF) remains unclear. To address this we examined neutrophils of PWCF to evaluate the cause and consequence of altered membrane cholesterol and identified the effects of lung transplantation and ion channel potentiator therapy on the cellular mechanisms responsible for perturbed membrane cholesterol and increased cell adhesion. PWCF homozygous for the ΔF508 mutation or heterozygous for the G551D mutation were recruited (n=48). Membrane protein expression was investigated by mass spectrometry. The effect of lung transplantation or ivacaftor therapy was assessed by ELISAs, and calcium fluorometric and μ-calpain assays. Membranes of CF neutrophils contain less cholesterol, yet increased integrin CD11b expression, and respond to inflammatory induced endoplasmic reticulum (ER) stress by activating μ-calpain. In vivo and in vitro, increased μ-calpain activity resulted in proteolysis of the membrane cholesterol trafficking protein caveolin-1. The critical role of caveolin-1 for adequate membrane cholesterol content was confirmed in caveolin-1 knock-out mice. Lung transplant therapy or treatment of PWCF with ivacaftor, reduced levels of circulating inflammatory mediators and actuated increased caveolin-1 and membrane cholesterol, with concurrent normalized neutrophil adhesion. Results demonstrate an auxiliary benefit of lung transplant and potentiator therapy, evident by a reduction in circulating inflammation and controlled neutrophil adhesion. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

The psychometric properties of the Leicester Cough Questionnaire and Respiratory Symptoms in CF tool in cystic fibrosis: A preliminary study.

PubMed

Ward, Nathan; Stiller, Kathy; Rowe, Hilary; Holland, Anne E

2017-05-01

There are few tools to quantify the impact of cough in cystic fibrosis (CF). The psychometric properties of the Leicester Cough Questionnaire (LCQ) and Respiratory Symptoms in CF (ReS-CF) tool were investigated in adults with CF. Validity and reliability were assessed in clinically stable participants who completed the questionnaires twice, along with the Cystic Fibrosis Questionnaire - Revised (CFQ-R). Responsiveness was assessed by change in questionnaires following treatment for an acute respiratory exacerbation. Correlations between the LCQ and CFQ-R respiratory domain were moderate (n=59, r s =0.78, p<0.001). Correlations between ReS-CF and CFQ-R respiratory domain were fair (r s =-0.50, p<0.001). The LCQ total score was repeatable (ICC 0.92, 95%CI 0.87-0.96, n=50). In those reporting improvement in symptoms following treatment (n=36), LCQ total score had a mean change of 4.6 (SD 3.7) and effect size of 1.2. The LCQ and ReS-CF appear to be valid, reliable and responsive in CF. www.anzctr.org.au: ACTRN12615000262505. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Vitamin K status in cystic fibrosis patients with liver cirrhosis.

PubMed

Krzyżanowska, Patrycja; Drzymała-Czyż, Sławomira; Pogorzelski, Andrzej; Duś-Żuchowska, Monika; Skorupa, Wojciech; Bober, Lyudmyla; Sapiejka, Ewa; Oralewska, Beata; Rohovyk, Nataliya; Moczko, Jerzy; Nowak, Jan; Wenska-Chyży, Ewa; Rachel, Marta; Lisowska, Aleksandra; Walkowiak, Jarosław

2017-06-01

The available data on the influence of liver cirrhosis on vitamin K status in CF patients is scarce. Therefore, the aims of the present study were to assess the prevalence of vitamin K deficiency in cirrhotic CF subjects and to determine whether it correlates with liver cirrhosis. The study group comprised of 27 CF patients with and 63 without liver cirrhosis. Vitamin K status was assessed using prothrombin induced by vitamin K absence (PIVKA-II) and the percentage of undercarboxylated osteocalcin (u-OC). PIVKA-II concentrations were higher in cirrhotic than in non-cirrhotic CF patients (median [1st-3rd quartile]: 3.2ng/ml [1.0-10.0] vs. 1.3ng/ml [0.2-2.6], p=0.0029). However, the differences in u-OC percentages between the studied groups did not reach the level of significance (49.4% [7.0-73.8] vs. 8.0% [2.6-59.1], p=0.0501). Based on multiple linear regression analysis the dose of vitamin K and F508del mutation were potentially defined as determinants of vitamin K deficiency. Liver cirrhosis was not documented to be an independent risk factor. In CF patients with liver cirrhosis vitamin K deficiency is not only more frequent, but also more severe. However, not liver cirrhosis, but the presence of a F508del CFTR mutation constitutes an independent risk factor for vitamin K deficiency. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Plasma lipidomics reveals potential prognostic signatures within a cohort of cystic fibrosis patients

PubMed Central

Ollero, Mario; Astarita, Giuseppe; Guerrera, Ida Chiara; Sermet-Gaudelus, Isabelle; Trudel, Stéphanie; Piomelli, Daniele; Edelman, Aleksander

2011-01-01

Cystic fibrosis (CF) is associated with abnormal lipid metabolism. We have recently shown variations in plasma levels of several phosphatidylcholine (PC) and lysophopshatidylcholine (LPC) species related to disease severity in CF patients. Here our goal was to search for blood plasma lipid signatures characteristic of CF patients bearing the same mutation (F508del) and different phenotypes, and to study their correlation with forced expiratory volume in 1 s (FEV1) and Pseudomonas aeruginosa chronic infection, evaluated at the time of testing (t = 0) and three years later (t = 3). Samples from 44 F508del homozygotes were subjected to a lipidomic approach based on LC-ESI-MS. Twelve free fatty acids were positively correlated with FEV1 at t = 0 (n = 29). Four of them (C20:3n-9, C20:5n-3, C22:5n-3, and C22:6n-3) were also positively correlated with FEV1 three years later, along with PC(32:2) and PC(36:4) (n = 31). Oleoylethanolamide (OEA) was negatively correlated with FEV1 progression (n = 17). Chronically infected patients at t = 0 showed lower PC(32:2), PC(38:5), and C18:3n-3 and higher cholesterol, cholesterol esters, and triacylglycerols (TAG). Chronically infected patients at t = 3 showed significantly lower levels of LPC(18:0). These results suggest a potential prognostic value for some lipid signatures in, to our knowledge, the first longitudinal study aimed at identifying lipid biomarkers for CF. PMID:21335323

Probing Conformational Rescue Induced by a Chemical Corrector of F508del-Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Mutant*

PubMed Central

Yu, Wilson; Chiaw, Patrick Kim; Bear, Christine E.

2011-01-01

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that cause loss of function of the CFTR channel on the apical surface of epithelial cells. The major CF-causing mutation, F508del-CFTR, is misfolded, retained in the endoplasmic reticulum, and degraded. Small molecule corrector compounds have been identified using high throughput screens, which partially rescue the trafficking defect of F508del-CFTR, allowing a fraction of the mutant protein to escape endoplasmic reticulum retention and traffic to the plasma membrane, where it exhibits partial function as a cAMP-regulated chloride channel. A subset of such corrector compounds binds directly to the mutant protein, prompting the hypothesis that they rescue the biosynthetic defect by inducing improved protein conformation. We tested this hypothesis directly by evaluating the consequences of a corrector compound on the conformation of each nucleotide binding domain (NBD) in the context of the full-length mutant protein in limited proteolytic digest studies. Interestingly, we found that VRT-325 was capable of partially restoring compactness in NBD1. However, VRT-325 had no detectable effect on the conformation of the second half of the molecule. In comparison, ablation of the di-arginine sequence, R553XR555 (F508del-KXK-CFTR), modified protease susceptibility of NBD1, NBD2, and the full-length protein. Singly, each intervention led to a partial correction of the processing defect. Together, these interventions restored processing of F508del-CFTR to near wild type. Importantly, however, a defect in NBD1 conformation persisted, as did a defect in channel activation after the combined interventions. Importantly, this defect in channel activation can be fully corrected by the addition of the potentiator, VX-770. PMID:21602569

Naturally Occurring Deletion Mutants of the Pig-Specific, Intestinal Crypt Epithelial Cell Protein CLCA4b without Apparent Phenotype

PubMed Central

Plog, Stephanie; Klymiuk, Nikolai; Binder, Stefanie; Van Hook, Matthew J.; Thoreson, Wallace B.; Gruber, Achim D.; Mundhenk, Lars

2015-01-01

The human CLCA4 (chloride channel regulator, calcium-activated) modulates the intestinal phenotype of cystic fibrosis (CF) patients via an as yet unknown pathway. With the generation of new porcine CF models, species-specific differences between human modifiers of CF and their porcine orthologs are considered critical for the translation of experimental data. Specifically, the porcine ortholog to the human CF modulator gene CLCA4 has recently been shown to be duplicated into two separate genes, CLCA4a and CLCA4b. Here, we characterize the duplication product, CLCA4b, in terms of its genomic structure, tissue and cellular expression patterns as well as its in vitro electrophysiological properties. The CLCA4b gene is a pig-specific duplication product of the CLCA4 ancestor and its protein is exclusively expressed in small and large intestinal crypt epithelial cells, a niche specifically occupied by no other porcine CLCA family member. Surprisingly, a unique deleterious mutation of the CLCA4b gene is spread among modern and ancient breeds in the pig population, but this mutation did not result in an apparent phenotype in homozygously affected animals. Electrophysiologically, neither the products of the wild type nor of the mutated CLCA4b genes were able to evoke a calcium-activated anion conductance, a consensus feature of other CLCA proteins. The apparently pig-specific duplication of the CLCA4 gene with unique expression of the CLCA4b protein variant in intestinal crypt epithelial cells where the porcine CFTR is also present raises the question of whether it may modulate the porcine CF phenotype. Moreover, the naturally occurring null variant of CLCA4b will be valuable for the understanding of CLCA protein function and their relevance in modulating the CF phenotype. PMID:26474299

[Pancreatic infringement exocrine and endocrine in cystic fibrosis].

PubMed

Kessler, L; Abély, M

2016-12-01

The exocrine pancreatic insufficiency affects more than 80% of cystic fibrosis (CF) infants. Pancreatic insufficiency is diagnosed by low levels of fecal elastase. An optimal caloric intake, a pancreatic enzyme treatment are the keys to maintain a good nutritional status. The fat soluble vitamins supplementation will be associated with pancreatic enzymes treatment and will be adapted to plasma levels. Iron and oligo-element deficiency such as zinc is common. The pancreatic enzymes function is not optimal in the proximal bowel: the intraluminal intestinal pH is low because of the absence of bicarbonate release by the pancreas. The use of proton pump inhibitors may improve the functionality of pancreatic enzymes treatment. New therapies such as ivacaftor in patients with a G551D mutation allows a weight gain in particular by restoring intestinal pH similar to controls. Lengthening of the life expectancy of patients with CF is accompanied by the emergence new aspects of the disease, especially diabetes, favored by pancreatic cystic fibrosis resulting in an anatomical destruction of pancreatic islets. Currently, diabetes affects a third of the patients after 20 years, and half after 30 years. Cystic fibrosis-related diabetes is a major factor of morbidity-mortality in all stages of the disease and is characterized by a preclinical phase of glucose intolerance particularly long reaching up to 10 years. Its pathophysiology combines a lack of insulin secretion, an insulin resistance secondary to chronic infection, and a decrease in the production of the GIP and GLP-1. The insulin secretion depending on the channel chlorine (Cystic Fibrosis Transmembrane conductance Regulator [CFTR]) activity at the membrane surface of insulin cell is reduced prior to the occurrence of pancreatic histological lesions. At the stage of diabetes, obtaining a normoglycemia by insulin treatment began very early allows to slow the decline of lung function and nutritional status. Given the silent phase of diabetes, screening it is recommended by the realization of an annual OGTT from 10 years of age, or before in severe forms of CF. New treatments of CF able to target CFTR showed their efficacy in slowing the decline of lung function, and could also contribute to slow or prevent the onset of diabetes. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

"No Time to Play": Perceptions toward Physical Activity in Youth with Cystic Fibrosis

ERIC Educational Resources Information Center

Moola, Fiona; Faulkner, Guy E. J.; Schneiderman, Jane E.

2012-01-01

Although physical activity may reduce lung function decline in youth with cystic fibrosis (CF), most patients are inactive. Little is known about why youth with CF are inactive or how to facilitate physical activity. This study explored perceptions toward physical activity in 14 youth with CF at a Canadian Hospital. Qualitative interviews were…

Burkholderia pseudomallei infection in a cystic fibrosis patient from the Caribbean: A case report

PubMed Central

Corral, Dimas Mateos; Coates, Allan L; Yau, Yvonne CW; Tellier, Raymond; Glass, Mindy; Jones, Steven M; Waters, Valerie J

2008-01-01

Burkholderia pseudomallei is a pathogen identified with increasing frequency in the respiratory tracts of cystic fibrosis (CF) patients from endemic areas such as Southeast Asia and northern Australia. The following report describes the first known reported case in a CF patient from the Caribbean attending a North American CF clinic. PMID:18716683

Allergic bronchopulmonary aspergillosis in patients with cystic fibrosis and non-cystic fibrosis bronchiectasis.

PubMed

Alyasin, Soheila; Moghtaderi, Mozhgan; Farjadian, Shirin; Babaei, Maryam; Teshnizi, Saeed Hosseini

2018-01-01

Aspergillus sensitization (AS) and allergic bronchopulmonary aspergillosis (ABPA) can occur as a cause of permanent lung damage in patients with cystic fibrosis (CF) and non-CF bronchiectasis. The aim of this study was to determine the frequency of AS and ABPA in patients with CF and non-CF bronchiectasis in southwestern Iran. This cross-sectional study was conducted on 33 patients with CF and 27 patients with non-CF bronchiectasis from southwestern Iran who were referred to Namazi Hospital affiliated to Shiraz University of Medical Sciences from July 2015 to February 2016. Skin prick test to Aspergillus fumigatus, peripheral blood eosinophil count, total serum IgE, specific IgE and IgG against Aspergillus fumigatus as well as radiologic chest studies were done for each patient. Statistical analysis was done by Mann-Whitney U test, Fisher Exact test, and Kappa weighted in SPSS software version 18. Level of significance was set at p<0.05. Nine patients with CF (27.3%) and one patient with non-CF bronchiectasis (3.7%) had positive skin tests to Aspergillus. There was 81.2% agreement between positive skin test and specific IgE to Aspergillus fumigatus (p<0.001). Three patients with CF (9%) met the diagnostic criteria for ABPA, whereas ABPA was not seen in patients with non-CF bronchiectasis. ABPA was low in this study, considering more frequency of AS in patients with cystic fibrosis, clinicians should keep in mind the diagnosis of ABPA for those CF patients that do not respond to usual medical therapy and have positive skin tests to Aspergillus allergens.

Defining palliative care in cystic fibrosis: A Delphi study.

PubMed

Dellon, E P; Goggin, J; Chen, E; Sabadosa, K; Hempstead, S E; Faro, A; Homa, K

2018-05-01

The goal of palliative care is to improve quality of life for people with serious illness. We aimed to create a cystic fibrosis (CF)-specific definition of palliative care. A working group of 36 CF care providers, researchers, palliative care providers, quality improvement experts, individuals with CF, and CF caregivers completed a series of questionnaires to rate the value of each of 22 attributes of palliative care, rank top attributes to construct definitions of palliative care, and then rate proposed definitions. An average of 28 participants completed each of four questionnaires, with consistent distribution of stakeholder roles across questionnaires. Many identified overlaps in routine CF care and palliative care and highlighted the importance of a definition that feels relevant across the lifespan. Modified Delphi methodology was used to define palliative care in CF. The definition will be used as the foundation for development of CF-specific palliative care guidelines. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Is bronchoscopy an obsolete tool in cystic fibrosis? The role of bronchoscopy in cystic fibrosis and its clinical use

PubMed Central

2017-01-01

Cystic fibrosis (CF) is a progressive life threatening multisystem genetic disease which affects the CF transmembrane conductance regulator channel. Respiratory causes remain the most common mortality in CF. With the onset of newborn screening, initiating treatments both for prophylaxis and disease management, optimizing nutritional support, and developing therapies targeting CF transmembrane conductance regulator protein, this has significantly changed the face of managing this devastating disease. Bronchoscopy and related procedures such as bronchoalveolar lavage (BAL), transbronchial biopsies, and protected brush sampling have been looked at in the management of CF as patients with CF continue to live longer with the help of newer therapies, the microbiome in the lung becomes less diverse along with increased occurrences for noninfectious causes of airway diseases. Though bronchoscopy has been used in conjunction with other modalities such as computed tomography and sputum induction providing a better understanding of the progression of the disease, it still remains valuable in the diagnosis and management of CF. PMID:29214071

Substance P stimulates human airway submucosal gland secretion mainly via a CFTR-dependent process

PubMed Central

Choi, Jae Young; Khansaheb, Monal; Joo, Nam Soo; Krouse, Mauri E.; Robbins, Robert C.; Weill, David; Wine, Jeffrey J.

2009-01-01

Chronic bacterial airway infections are the major cause of mortality in cystic fibrosis (CF). Normal airway defenses include reflex stimulation of submucosal gland mucus secretion by sensory neurons that release substance P (SubP). CFTR is an anion channel involved in fluid secretion and mutated in CF; the role of CFTR in secretions stimulated by SubP is unknown. We used optical methods to measure SubP-mediated secretion from human submucosal glands in lung transplant tissue. Glands from control but not CF subjects responded to mucosal chili oil. Similarly, serosal SubP stimulated secretion in more than 60% of control glands but only 4% of CF glands. Secretion triggered by SubP was synergistic with vasoactive intestinal peptide and/or forskolin but not with carbachol; synergy was absent in CF glands. Pig glands demonstrated a nearly 10-fold greater response to SubP. In 10 of 11 control glands isolated by fine dissection, SubP caused cell volume loss, lumen expansion, and mucus flow, but in 3 of 4 CF glands, it induced lumen narrowing. Thus, in CF, the reduced ability of mucosal irritants to stimulate airway gland secretion via SubP may be another factor that predisposes the airways to infections. PMID:19381016

Rapid adaptation drives invasion of airway donor microbiota by Pseudomonas after lung transplantation.

PubMed

Beaume, M; Köhler, T; Greub, G; Manuel, O; Aubert, J-D; Baerlocher, L; Farinelli, L; Buckling, A; van Delden, C

2017-01-17

In cystic fibrosis (CF) patients, chronic airway infection by Pseudomonas leads to progressive lung destruction ultimately requiring lung transplantation (LT). Following LT, CF-adapted Pseudomonas strains, potentially originating from the sinuses, may seed the allograft leading to infections and reduced allograft survival. We investigated whether CF-adapted Pseudomonas populations invade the donor microbiota and adapt to the non-CF allograft. We collected sequential Pseudomonas isolates and airway samples from a CF-lung transplant recipient during two years, and followed the dynamics of the microbiota and Pseudomonas populations. We show that Pseudomonas invaded the host microbiota within three days post-LT, in association with a reduction in richness and diversity. A dominant mucoid and hypermutator mutL lineage was replaced after 11 days by non-mucoid strains. Despite antibiotic therapy, Pseudomonas dominated the allograft microbiota until day 95. We observed positive selection of pre-LT variants and the appearance of novel mutations. Phenotypic adaptation resulted in increased biofilm formation and swimming motility capacities. Pseudomonas was replaced after 95 days by a microbiota dominated by Actinobacillus. In conclusion, mucoid Pseudomonas adapted to the CF-lung remained able to invade the allograft. Selection of both pre-existing non-mucoid subpopulations and of novel phenotypic traits suggests rapid adaptation of Pseudomonas to the non-CF allograft.

Forskolin-induced Swelling in Intestinal Organoids: An In Vitro Assay for Assessing Drug Response in Cystic Fibrosis Patients.

PubMed

Boj, Sylvia F; Vonk, Annelotte M; Statia, Marvin; Su, Jinyi; Vries, Robert R G; Beekman, Jeffrey M; Clevers, Hans

2017-02-11

Recently-developed cystic fibrosis transmembrane conductance regulator (CFTR)-modulating drugs correct surface expression and/or function of the mutant CFTR channel in subjects with cystic fibrosis (CF). Identification of subjects that may benefit from these drugs is challenging because of the extensive heterogeneity of CFTR mutations, as well as other unknown factors that contribute to individual drug efficacy. Here, we describe a simple and relatively rapid assay for measuring individual CFTR function and response to CFTR modulators in vitro. Three dimensional (3D) epithelial organoids are grown from rectal biopsies in standard organoid medium. Once established, the organoids can be bio-banked for future analysis. For the assay, 30-80 organoids are seeded in 96-well plates in basement membrane matrix and are then exposed to drugs. One day later, the organoids are stained with calcein green, and forskolin-induced swelling is monitored by confocal live cell microscopy at 37 °C. Forskolin-induced swelling is fully CFTR-dependent and is sufficiently sensitive and precise to allow for discrimination between the drug responses of individuals with different and even identical CFTR mutations. In vitro swell responses correlate with the clinical response to therapy. This assay provides a cost-effective approach for the identification of drug-responsive individuals, independent of their CFTR mutations. It may also be instrumental in the development of future CFTR modulators.

Insights into the cystic fibrosis care in Eastern Europe: Results of survey.

PubMed

Walicka-Serzysko, Katarzyna; Peckova, Monika; Noordhoek, Jacquelien J; Sands, Dorota; Drevinek, Pavel

2018-04-19

The European cystic fibrosis (CF) Society Standards of Care were set to facilitate the delivery of high-quality care throughout Europe. However, their implementation may be difficult for less economically advantaged countries. This survey was performed to explore the gap in the knowledge of the level of CF care in Eastern Europe. Questionnaires were sent online to one CF professional and one CF patient representative for every Eastern European country. Although most respondents indicated the presence of CF centres, disparities in their framework among individual countries and between them and the European CF Standards of Care became apparent. A minority of countries achieved CF centre recognition by the government (6 of 16), provided CF care for adults (6 countries) and had a multidisciplinary team with all team members represented (2 countries). Patients were significantly more critical in the evaluation of various aspects of CF care than physicians, especially in the Balkan region. The survey results indicate that the organization and level of CF care across Eastern Europe is largely variable and lacks some of its fundamental attributes in several countries. Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Epithelial IgG and its relationship to the loss of F508 in the common mutant form of the cystic fibrosis transmembrane conductance regulator.

PubMed

Treharne, Kate J; Cassidy, Diane; Goddard, Catharine; Colledge, William H; Cassidy, Andrew; Mehta, Anil

2009-08-06

The most debilitating feature of cystic fibrosis (CF) disease is uncontrolled inflammation of respiratory epithelium. The relationship between the commonest mutated form of CFTR (F508del or DeltaF508) and inflammation has not yet been elucidated. Here, we present a new paradigm suggesting that CFTR can interact with intra-epithelial IgG, establishing a direct link between normal CFTR and the immune system. Further, our data show that the amino-acid sequence local to F508 can bind IgG with high affinity, dependent on F508, such that loss of F508 abolishes this link both in vitro and in the intact cell.

Airway disease phenotypes in animal models of cystic fibrosis.

PubMed

McCarron, Alexandra; Donnelley, Martin; Parsons, David

2018-04-02

In humans, cystic fibrosis (CF) lung disease is characterised by chronic infection, inflammation, airway remodelling, and mucus obstruction. A lack of pulmonary manifestations in CF mouse models has hindered investigations of airway disease pathogenesis, as well as the development and testing of potential therapeutics. However, recently generated CF animal models including rat, ferret and pig models demonstrate a range of well characterised lung disease phenotypes with varying degrees of severity. This review discusses the airway phenotypes of currently available CF animal models and presents potential applications of each model in airway-related CF research.

Antenatal testing for cystic fibrosis in Cuba, 1988-2011.

PubMed

Collazo, Teresa; López, Ixchel; Clark, Yulia; Piloto, Yaixa; González, Laura; Gómez, Manuel; García, Marileivis; Reyes, Lidice; Rodríguez, Fidel

2014-01-01

INTRODUCTION Cystic fibrosis is a multisystem autosomal recessive disease with wide variability in clinical severity. It is incurable and characterized by elevated and premature mortality, as well as poor quality of life. Its frequency, lethality and devastating impact on both the physical and psychological wellbeing of patients and their families, make it a serious health problem. Its frequency in Cuba is 1 in 9862 live births, where marked molecular heterogeneity of the CFTR gene makes molecular diagnosis difficult. Six mutations have been identified that together enable molecular characterization of only 55.5% of cystic fibrosis chromosomes. This paper presents national results of antenatal diagnostic testing, using direct and indirect methods, for detection of cystic fibrosis. OBJECTIVE Characterize the Cuban public health system's experience with antenatal molecular testing for cystic fibrosis from 1988 through 2011. METHODS A retrospective descriptive study was conducted with results of antenatal diagnostic testing of amniotic fluid, performed nationwide from 1988 through 2011, for 108 fetuses of couples with some risk of having children affected by cystic fibrosis, who requested testing. Polymerase chain reaction detected mutations p.F508del, p.G542X, p.R1162X, p.R334W, p.R553X and c.3120+1G>A, and markers XV2C and KM19. Data were analyzed using absolute frequencies and percentages, and presented in tables. RESULTS For 93 cases (86.1%), testing for cystic fibrosis was done using direct analysis of mutations p.F508del, p.G542X, p.R1162X, p.R334W, p.R553X and c.3120+1G>A; five cases (4.6%) were tested indirectly using markers XV2C/Taq I and KM19/Pst I; and 10 (9.3%) were tested using a combination of the two methods. A total of 72 diagnoses (66.7% of studies done) were concluded, of which there were 20 healthy fetuses, 16 affected, 27 carrier, and 9 who were either healthy or carriers of an unknown mutation. CONCLUSIONS Direct or indirect molecular study was successfully used in over half of antenatal tests requested by couples throughout Cuba at risk of having children affected by cystic fibrosis, which is of great social value because of CF's burden on affected persons and their families.

Evolution and adaptation in Pseudomonas aeruginosa biofilms driven by mismatch repair system-deficient mutators.

PubMed

Luján, Adela M; Maciá, María D; Yang, Liang; Molin, Søren; Oliver, Antonio; Smania, Andrea M

2011-01-01

Pseudomonas aeruginosa is an important opportunistic pathogen causing chronic airway infections, especially in cystic fibrosis (CF) patients. The majority of the CF patients acquire P. aeruginosa during early childhood, and most of them develop chronic infections resulting in severe lung disease, which are rarely eradicated despite intensive antibiotic therapy. Current knowledge indicates that three major adaptive strategies, biofilm development, phenotypic diversification, and mutator phenotypes [driven by a defective mismatch repair system (MRS)], play important roles in P. aeruginosa chronic infections, but the relationship between these strategies is still poorly understood. We have used the flow-cell biofilm model system to investigate the impact of the mutS associated mutator phenotype on development, dynamics, diversification and adaptation of P. aeruginosa biofilms. Through competition experiments we demonstrate for the first time that P. aeruginosa MRS-deficient mutators had enhanced adaptability over wild-type strains when grown in structured biofilms but not as planktonic cells. This advantage was associated with enhanced micro-colony development and increased rates of phenotypic diversification, evidenced by biofilm architecture features and by a wider range and proportion of morphotypic colony variants, respectively. Additionally, morphotypic variants generated in mutator biofilms showed increased competitiveness, providing further evidence for mutator-driven adaptive evolution in the biofilm mode of growth. This work helps to understand the basis for the specific high proportion and role of mutators in chronic infections, where P. aeruginosa develops in biofilm communities.

Evolution and Adaptation in Pseudomonas aeruginosa Biofilms Driven by Mismatch Repair System-Deficient Mutators

PubMed Central

Yang, Liang; Molin, Søren; Oliver, Antonio; Smania, Andrea M.

2011-01-01

Pseudomonas aeruginosa is an important opportunistic pathogen causing chronic airway infections, especially in cystic fibrosis (CF) patients. The majority of the CF patients acquire P. aeruginosa during early childhood, and most of them develop chronic infections resulting in severe lung disease, which are rarely eradicated despite intensive antibiotic therapy. Current knowledge indicates that three major adaptive strategies, biofilm development, phenotypic diversification, and mutator phenotypes [driven by a defective mismatch repair system (MRS)], play important roles in P. aeruginosa chronic infections, but the relationship between these strategies is still poorly understood. We have used the flow-cell biofilm model system to investigate the impact of the mutS associated mutator phenotype on development, dynamics, diversification and adaptation of P. aeruginosa biofilms. Through competition experiments we demonstrate for the first time that P. aeruginosa MRS-deficient mutators had enhanced adaptability over wild-type strains when grown in structured biofilms but not as planktonic cells. This advantage was associated with enhanced micro-colony development and increased rates of phenotypic diversification, evidenced by biofilm architecture features and by a wider range and proportion of morphotypic colony variants, respectively. Additionally, morphotypic variants generated in mutator biofilms showed increased competitiveness, providing further evidence for mutator-driven adaptive evolution in the biofilm mode of growth. This work helps to understand the basis for the specific high proportion and role of mutators in chronic infections, where P. aeruginosa develops in biofilm communities. PMID:22114708

Pseudomonas aeruginosa Regulated Intramembrane Proteolysis (RIP): Protease MucP can Overcome Mutations in the AlgO Periplasmic Protease to Restore Alginate Production in Nonmucoid Revertants.

PubMed

Delgado, Camila; Florez, Laura; Lollett, Ivonne; Lopez, Christine; Kangeyan, Shiva; Kumari, Hansi; Stylianou, Marios; Smiddy, Robert J; Schneper, Lisa; Sautter, Robert T; Szatmari, George; Mathee, Kalai

2018-05-21

The progression of cystic fibrosis (CF) from an acute to a chronic disease is often associated with the conversion of the opportunistic pathogen Pseudomonas aeruginosa from a nonmucoid form to a mucoid form in the lung. This conversion involves the overproduction of the exopolysaccharide alginate, whose production is under control of the AlgT/U sigma factor. This factor is regulated posttranslationally by an extremely unstable process and has been commonly attributed to mutations in the algT/U gene. By exploiting this unstable phenotype, we isolated 34 spontaneous nonmucoid variants arising from the mucoid strain PDO300, a PAO1 derivative containing the mucA22 allele commonly found in mucoid CF isolates. Complementation analysis using a minimal tiling path cosmid library revealed that most of these mutants mapped to two protease-encoding genes, algO also known as prc or PA3257 , and mucP. Interestingly, our algO mutations were complemented by both mucP and algO , leading us to delete, clone and overexpress mucP , algO , mucE and mucD in both wild-type PAO1 and in PDO300 backgrounds to better understand the regulation of this complex regulatory mechanism. Our findings suggest the regulatory proteases follow two pathways for regulated intramembrane proteolysis (RIP), where both the AlgO/MucP pathway and MucE/AlgW pathway are required in the wild type strain, but where the AlgO/MucP pathway can bypass the MucE/AlgW pathway in mucoid strains with membrane-associated forms of MucA with shortened C-termini, such as the MucA22 variant. This work gives us a better understanding of how alginate production is regulated in the clinically important mucoid variants of Pseudomonas aeruginosa. IMPORTANCE: Infection by the opportunistic pathogen Pseudomonas aeruginosa is the leading cause of morbidity and mortality seen in cystic fibrosis (CF) patients. Poor patient prognosis correlates with the genotypic and phenotypic change of the bacteria from a typical nonmucoid to a mucoid form in the CF lung, characterized by the overproduction of alginate. The expression of this exopolysaccharide is under the control an alternate sigma factor, AlgT/U, that is regulated post translationally by a series of proteases. A better understanding of this regulatory phenomenon will help in the development of therapies targeting alginate production, ultimately leading to an increase in the length and quality of life for those suffering from CF. Copyright © 2018 American Society for Microbiology.

Technological advances shed light on left ventricular cardiac disturbances in cystic fibrosis.

PubMed

Sayyid, Zahra N; Sellers, Zachary M

2017-07-01

Cystic fibrosis (CF), the most common autosomal recessive lethal disease in Caucasians, causes chronic pulmonary disease and can lead to cor pulmonale with right ventricular dysfunction. The presence of the cystic fibrosis transmembrane conductance regulator (CFTR) in cardiac myocardia has prompted debate regarding possible defective ion channel-induced cardiomyopathy. Clinical heart disease in CF is considered rare and is restricted to case reports. It has been unclear if this is due to the lack of physiological importance of CFTR in the heart, the relatively short lifespan of those with CF, or a technical inability to detect subclinical disease. Extensive echocardiographic investigations have yielded contradictory results, leading to the dogma that left ventricular defects in CF occur secondary to lung disease. In this review, we consider why studies examining heart function in CF have not provided clarity on this topic. We then focus on data from new echocardiographic and magnetic resonance imaging technology, which are providing greater insight into cardiac function in CF and demonstrating that, in addition to secondary effects from pulmonary disease, there may be an intrinsic primary defect in the CF heart. With advancing lifespans and activity levels, understanding the risk of cardiac disease is vital to minimizing morbidity in adults with CF. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Pseudomonas aeruginosa and Periodontal Pathogens in the Oral Cavity and Lungs of Cystic Fibrosis Patients: a Case-Control Study

PubMed Central

Le Gall, Florence; Revert, Krista; Rault, Gilles; Virmaux, Michèle; Gouriou, Stephanie; Héry-Arnaud, Geneviève; Barbier, Georges; Boisramé, Sylvie

2015-01-01

Cystic fibrosis (CF) is the most frequent lethal genetic disease in the Caucasian population. Lung destruction is the principal cause of death by chronic Pseudomonas aeruginosa colonization. There is a high prevalence of oropharyngeal anaerobic bacteria in sputum of CF patients. This study was carried out due to the lack of results comparing subgingival periodontal pathogenic bacteria between the oral cavity and lungs in patients with CF in relation with P. aeruginosa presence. Our first goal was to detect P. aeruginosa in oral and sputum samples by culture and molecular methods and to determine clonality of isolates. In addition, subgingival periodontal anaerobic bacteria were searched for in sputum. A cross-sectional pilot case-control study was conducted in the CF Reference Center in Roscoff, France. Ten CF patients with a ΔF508 homozygous mutation (5 chronically colonized [CC] and 5 not colonized [NC]) were enrolled. P. aeruginosa was detected in saliva, sputum, and subgingival plaque samples by real-time quantitative PCR (qPCR). Subsequently, periodontal bacteria were also detected and quantified in subgingival plaque and sputum samples by qPCR. In CC patients, P. aeruginosa was recovered in saliva and subgingival plaque samples. Sixteen P. aeruginosa strains were isolated in saliva and sputum from this group and compared by pulsed-field gel electrophoresis (PFGE). Subgingival periodontal anaerobic bacteria were found in sputum samples. A lower diversity of these species was recovered in the CC patients than in the NC patients. The presence of the same P. aeruginosa clonal types in saliva and sputum samples underlines that the oral cavity is a possible reservoir for lung infection. PMID:25854483

Single-cell high resolution melting analysis: A novel, generic, pre-implantation genetic diagnosis (PGD) method applied to cystic fibrosis (HRMA CF-PGD).

PubMed

Destouni, A; Poulou, M; Kakourou, G; Vrettou, C; Tzetis, M; Traeger-Synodinos, J; Kitsiou-Tzeli, S

2016-03-01

Institutions offering CF-PGD face the challenge of developing and optimizing single cell genotyping protocols that should cover for the extremely heterogeneous CF mutation spectrum. Here we report the development and successful clinical application of a generic CF-PGD protocol to facilitate direct detection of any CFTR nucleotide variation(s) by HRMA and simultaneous confirmation of diagnosis through haplotype analysis. A multiplex PCR was optimized supporting co-amplification of any CFTR exon-region, along with 6 closely linked STRs. Single cell genotypes were established through HRM analysis following melting of the 2nd round PCR products and were confirmed by STR haplotype analysis of the 1st PCR products. The protocol was validated pre-clinically, by testing 208 single lymphocytes, isolated from whole blood samples from 4 validation family trios. Fifteen PGD cycles were performed and 103 embryos were biopsied. In 15 clinical PGD cycles, genotypes were achieved in 88/93 (94.6%) embryo biopsy samples, of which 57/88 (64.8%) were deemed genetically suitable for embryo transfer. Amplification failed at all loci for 10/103 blastomeres biopsied from poor quality embryos. Six clinical pregnancies were achieved (2 twin, 4 singletons). PGD genotypes were confirmed following conventional amniocentesis or chorionic villus sampling in all achieved pregnancies. The single cell HRMA CF-PGD protocol described herein is a flexible, generic, low cost and robust genotyping method, which facilitates the analysis of any CFTR genotype combination. Single-cell HRMA can be beneficial to other clinical settings, for example the detection of single nucleotide variants in single cells derived from clinical tumor samples. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Quorum Sensing Down-Regulation Counteracts the Negative Impact of Pseudomonas aeruginosa on CFTR Channel Expression, Function and Rescue in Human Airway Epithelial Cells

PubMed Central

Maillé, Émilie; Ruffin, Manon; Adam, Damien; Messaoud, Hatem; Lafayette, Shantelle L.; McKay, Geoffrey; Nguyen, Dao; Brochiero, Emmanuelle

2017-01-01

The function of cystic fibrosis transmembrane conductance regulator (CFTR) channels is crucial in human airways. However unfortunately, chronic Pseudomonas aeruginosa infection has been shown to impair CFTR proteins in non-CF airway epithelial cells (AEC) and to alter the efficiency of new treatments with CFTR modulators designed to correct the basic CFTR default in AEC from cystic fibrosis (CF) patients carrying the F508del mutation. Our aim was first to compare the effect of laboratory strains, clinical isolates, engineered and natural mutants to determine the role of the LasR quorum sensing system in CFTR impairment, and second, to test the efficiency of a quorum sensing inhibitor to counteract the deleterious impact of P. aeruginosa both on wt-CFTR and on the rescue of F508del-CFTR by correctors. We first report that exoproducts from either the laboratory PAO1 strain or a clinical ≪Early≫ isolate (from an early stage of infection) altered CFTR expression, localization and function in AEC expressing wt-CFTR. Genetic inactivation of the quorum-sensing LasR in PAO1 (PAO1ΔlasR) or in a natural clinical mutant (≪Late≫ CF-adapted clinical isolate) abolished wt-CFTR impairment. PAO1 exoproducts also dampened F508del-CFTR rescue by VRT-325 or Vx-809 correctors in CF cells, whereas PAO1ΔlasR had no impact. Importantly, treatment of P. aeruginosa cultures with a quorum sensing inhibitor (HDMF) prevented the negative effect of P. aeruginosa exoproducts on wt-CFTR and preserved CFTR rescue by correctors in CF AEC. These findings indicate that LasR-interfering strategies could be of benefits to counteract the deleterious effect of P. aeruginosa in infected patients. PMID:29177135

Meconium ileus caused by mutations in GUCY2C, encoding the CFTR-activating guanylate cyclase 2C.

PubMed

Romi, Hila; Cohen, Idan; Landau, Daniella; Alkrinawi, Suliman; Yerushalmi, Baruch; Hershkovitz, Reli; Newman-Heiman, Nitza; Cutting, Garry R; Ofir, Rivka; Sivan, Sara; Birk, Ohad S

2012-05-04

Meconium ileus, intestinal obstruction in the newborn, is caused in most cases by CFTR mutations modulated by yet-unidentified modifier genes. We now show that in two unrelated consanguineous Bedouin kindreds, an autosomal-recessive phenotype of meconium ileus that is not associated with cystic fibrosis (CF) is caused by different homozygous mutations in GUCY2C, leading to a dramatic reduction or fully abrogating the enzymatic activity of the encoded guanlyl cyclase 2C. GUCY2C is a transmembrane receptor whose extracellular domain is activated by either the endogenous ligands, guanylin and related peptide uroguanylin, or by an external ligand, Escherichia coli (E. coli) heat-stable enterotoxin STa. GUCY2C is expressed in the human intestine, and the encoded protein activates the CFTR protein through local generation of cGMP. Thus, GUCY2C is a likely candidate modifier of the meconium ileus phenotype in CF. Because GUCY2C heterozygous and homozygous mutant mice are resistant to E. coli STa enterotoxin-induced diarrhea, it is plausible that GUCY2C mutations in the desert-dwelling Bedouin kindred are of selective advantage. Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Endoplasmic Reticulum Protein TXNDC5 Augments Myocardial Fibrosis by Facilitating Extracellular Matrix Protein Folding and Redox-Sensitive Cardiac Fibroblast Activation.

PubMed

Shih, Ying-Chun; Chen, Chao-Ling; Zhang, Yan; Mellor, Rebecca L; Kanter, Evelyn M; Fang, Yun; Wang, Hua-Chi; Hung, Chen-Ting; Nong, Jing-Yi; Chen, Hui-Ju; Lee, Tzu-Han; Tseng, Yi-Shuan; Chen, Chiung-Nien; Wu, Chau-Chung; Lin, Shuei-Liong; Yamada, Kathryn A; Nerbonne, Jeanne M; Yang, Kai-Chien

2018-04-13

Cardiac fibrosis plays a critical role in the pathogenesis of heart failure. Excessive accumulation of extracellular matrix (ECM) resulting from cardiac fibrosis impairs cardiac contractile function and increases arrhythmogenicity. Current treatment options for cardiac fibrosis, however, are limited, and there is a clear need to identify novel mediators of cardiac fibrosis to facilitate the development of better therapeutics. Exploiting coexpression gene network analysis on RNA sequencing data from failing human heart, we identified TXNDC5 (thioredoxin domain containing 5), a cardiac fibroblast (CF)-enriched endoplasmic reticulum protein, as a potential novel mediator of cardiac fibrosis, and we completed experiments to test this hypothesis directly. The objective of this study was to determine the functional role of TXNDC5 in the pathogenesis of cardiac fibrosis. RNA sequencing and Western blot analyses revealed that TXNDC5 mRNA and protein were highly upregulated in failing human left ventricles and in hypertrophied/failing mouse left ventricle. In addition, cardiac TXNDC5 mRNA expression levels were positively correlated with those of transcripts encoding transforming growth factor β1 and ECM proteins in vivo. TXNDC5 mRNA and protein were increased in human CF (hCF) under transforming growth factor β1 stimulation in vitro. Knockdown of TXNDC5 attenuated transforming growth factor β1-induced hCF activation and ECM protein upregulation independent of SMAD3 (SMAD family member 3), whereas increasing expression of TXNDC5 triggered hCF activation and proliferation and increased ECM protein production. Further experiments showed that TXNDC5, a protein disulfide isomerase, facilitated ECM protein folding and that depletion of TXNDC5 led to ECM protein misfolding and degradation in CF. In addition, TXNDC5 promotes hCF activation and proliferation by enhancing c-Jun N-terminal kinase activity via increased reactive oxygen species, derived from NAD(P)H oxidase 4. Transforming growth factor β1-induced TXNDC5 upregulation in hCF was dependent on endoplasmic reticulum stress and activating transcription factor 6-mediated transcriptional control. Targeted disruption of Txndc5 in mice ( Txndc5 -/- ) revealed protective effects against isoproterenol-induced cardiac hypertrophy, reduced fibrosis (by ≈70%), and markedly improved left ventricle function; post-isoproterenol left ventricular ejection fraction was 59.1±1.5 versus 40.1±2.5 ( P <0.001) in Txndc5 -/- versus wild-type mice, respectively. The endoplasmic reticulum protein TXNDC5 promotes cardiac fibrosis by facilitating ECM protein folding and CF activation via redox-sensitive c-Jun N-terminal kinase signaling. Loss of TXNDC5 protects against β agonist-induced cardiac fibrosis and contractile dysfunction. Targeting TXNDC5, therefore, could be a powerful new therapeutic approach to mitigate excessive cardiac fibrosis, thereby improving cardiac function and outcomes in patients with heart failure. © 2018 American Heart Association, Inc.

Long-term follow-up of distal intestinal obstruction syndrome in cystic fibrosis.

PubMed

Lavie, Moran; Manovitz, Tzipora; Vilozni, Daphna; Levy-Mendelovich, Sarina; Sarouk, Ifat; Weintraubv, Ilana; Shoseyov, David; Cohen-Cymberknoh, Malena; Rivlin, Joseph; Efrati, Ori

2015-01-07

To investigate the long-term follow-up of distal intestinal obstruction syndrome (DIOS) in Israeli cystic fibrosis (CF) patients. This is a multi-center, comparative, retrospective study in which we reviewed the medical records of all CF patients from three major CF centers in Israel who were treated in the period from 1980 to 2012. Patients diagnosed with DIOS were defined as the study group. The patients were diagnosed with DIOS based on their clinical presentation and typical findings on either abdominal X-ray or computerized tomography scan. For the control group, CF patients with no DIOS were matched to the patients in the study group for age, sex, and cystic fibrosis transmembrane conductance regulator (CFTR) mutations. For both groups, the collected data included age, sex, CFTR genotype, weight, height, and body mass index. Clinical data included respiratory function tests in the last five years prior to the study, respiratory function test immediately before and after the DIOS event, number of hospitalizations, sputum culture results, and CF-related conditions diagnosed according to the CF clinical practice guidelines. In the study group, data on the DIOS treatment and tendency for DIOS recurrence were also analyzed. The medical charts for a total of 350 CF patients were reviewed. Of the 350 CF patients, 26 (7.4%) were diagnosed with DIOS. The control group included 31 CF patients with no DIOS diagnosis. The mean follow-up period was 21.6 ± 8.2 years. The total of DIOS episodes in the follow-up period was 60. The distribution of DIOS episodes was as follows: 6/26 (23.1%) study patients had one episode of DIOS in their lifetime, 7/26 (26.9%) had two episodes, 7/26 (26.9%) had three episodes, and 6/26 (23.1%) had four or more episodes. Compared to the control group, DIOS patients had a significantly higher incidence of meconium ileus in the past (65.4% vs 0%, respectively, P < 0.02), more Aspergillus spp. colonization (34.6% vs 3.2%, respectively, P < 0.02), and a higher number of hospitalizations due to respiratory exacerbations (8.6 vs 6.2 mean total hospitalizations per follow-up period, respectively, P < 0.02). No other significant differences were found between the control and study groups. The conservative treatment of DIOS, which mainly includes hydration and stool softeners, was successful in 82% of the episodes. The survival rate was similar for both groups. CF patients with DIOS suffer from recurrent hospitalizations and airway pathogen acquisition. Although recurrence of DIOS is common, conservative treatment is successful in most patients.

Newborn bloodspot screening for cystic fibrosis: What do antenatal and postnatal women know about cystic fibrosis?

PubMed

Fitzgerald, C; Linnane, B; Heery, E; Conneally, N; George, S; Fitzpatrick, P

2016-07-01

The Republic of Ireland has one of the highest reported incidences of cystic fibrosis (CF) in the world (1/1353) with an estimated carrier rate of 1/20. No cure exists, however there have been significant advances in available treatments. Newborn bloodspot screening (NBS) for CF was added to the NBS programme in Ireland in July 2011. Little is known about antenatal or postnatal women's knowledge about CF. This was a cross-sectional study of 662 antenatal (≥36weeks gestation) and 480 postnatal women (post NBS). Women were asked to self-complete a questionnaire including 14 CF knowledge questions. Among the respondents significantly more postnatal than antenatal women were aware that CF is included on the NBS (81.8% vs 63.5%; p<0.001). 92.7% believe that there are health consequences to being a carrier and 33.6% believe there is a cure for CF. In the multivariate analysis, lower educational status (OR 2.13; 95% CI 1.31, 3.46) being an antenatal mother (OR 1.51; 95% CI 1.04, 2.18), having no family history of CF (OR 5.82; 95% CI 1.62, 20.90) were associated with poor CF knowledge, while increasing age was found to be protective against poor CF knowledge (OR 0.96; 95% CI 0.92, 0.99). Results from this study provide a useful insight into women's preexisting knowledge about CF, which could be used to inform initial discussions with parents about their child's diagnosis. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

[Italian Cystic Fibrosis Registry. Report 2011-2014].

PubMed

Giordani, Barbara; Amato, Annalisa; Majo, Fabio; Ferrari, Gianluca; Quattrucci, Serena; Minicucci, Laura; Padoan, Rita; Floridia, Giovanna; Puppo Fornaro, Gianna; Taruscio, Domenica; Salvatore, Marco

2018-01-01

The Italian Cystic Fibrosis Registry (ICFR) is based on a new agreement about the data flow towards the Registry signed on October, 4th 2016 by the Centre for Rare Diseases of the Italian National Institute of Health (NIH), the clinicians of the Italian National Referral and Support Centres for Cystic Fibrosis, the Paediatric Hospital "Bambino Gesù" (Rome), the Italian Cystic Fibrosis Society, and the Italian League for Cystic Fibrosis. The aim of the present Report is to improve the knowledge on cystic fibrosis (CF) through the epidemiological description of Italian patients. The members of the Scientific and Technical Committee have to write a report on data collected by ICFR, in order to contribute to achieve the aims of ICFR itself, i.e., to improve the care of CF patients. In particular, the Report should contribute to the following objectives: - to analyze the medium and long-term clinical and epidemiological trends of the disease; - to identify the main healthcare needs at regional and national level in order to contribute to the healthcare programmes and to the distribution of resources; - to compare Italian data with the international ones. Analyses and results described in the present Report are referred to patients in charge to the Italian National Referral and Support Centres for Cystic Fibrosis in the period 2011-2014. Data were sent by Centres by means of a specific software (Camilla, Ibis Informatica) and has undergone a double quality control (QC): the first by NIH and the second at a European level (before the inclusion of the Italian data within the European Cystic Fibrosis Registry). These QCs assure the completeness and accuracy of data as well as their consistency with European core data. A total of 29 different CF centres (referral, support, and Paediatric Hospital "Bambino Gesù") sent their data to ICFR; data referred to the period 2011-2014. Data regarding Sardinia Region (Southern Italy) are missing; data from Molise (Southern Italy) CF centre refer only to 2014. The present Report has been organized into 10 sections. 1. Demography - number of Italian patients with cystic fibrosis (CF) in 2014 was 4,981 and their median age was 20.4 years; estimated 2014 CF prevalence was 8.2/100,000 residents in Italy; on average, 52.1% of the patients were male and CF distribution showed higher frequency in patients aged from 7 to 35 years. On average, 53.7% of CF patients are aged more than 18 years. 2. Diagnoses - most of the CF patients were diagnosed before two years of age (around 66%); a significant proportion of patients (on average, 12%) was diagnosed in adult age. 3. New diagnoses - new diagnoses were 187 in 2011, 200 in 2012, 160 in 2013, and 135 in 2014. Estimated incidence was 1/4,052 live births in 2011; 1/4,313 in 2012; 1/5,189 in 2013 and 1/8,243 in 2014. 4. Genetics - 99.5% of patients was studied at the molecular level, with identification of 90.1% of Cystic Fibrosis Transmembrane Regulator CFTR mutations; [delta]508F was the most frequent mutation (44.8% in 2014). 5. Lung function - FEV₁ (Forced Expiratory Volume in the first second) scores progressively decreased shortly before the start of adult age, in accordance with the natural history of the disease. Most of the patients between 6 and 17 years of age reported a FEV₁ % ≥ 70% of the predicted value, while the proportion of patients with severe lung disease (FEV₁ % <40% of the predicted value) is <2% over the period 2011-2014. 6. Nutrition - most critical periods come out during the first 6 months of life and during adolescence. Prevalence of malnourished male aged 12-17 years decreases over the period 2011-2014; an increasing percentage of patient (both male and female) with a suboptimal body mass index value is observed among patients aged more than 18 years 7. Complications - the presence of missing data represents an obstacle in the correct evaluation of prevalence value of complications related to Italian patients within ICFR. Nevertheless, it was estimated that, in 2014, the principal complication in patients aged <18 years was hepatopathies (15%), while in patients aged more than 18 years the principal complications were due to hepatopathies (25%) and diabetes (22%). 8. Transplantation - during the period 2011-2014, 135 patients ageed between 7 and 53 years received a double lung transplant; median age at transplantation was 32.5 years. Median duration of waiting list for transplantation is estimated in 11 months. 9. Microbiology - analyses were referred to test performed in 2014. Prevalence of adult patients with Pseudomonas aeruginosa chronic infection is 49.4% compared to 14.5% of paediatric patients; Staphylococcus aureus chronic infection is present in 48% of adult patients and 45.6% of paediatric patients; Burkholderia Cepacia complex is present almost exclusively in adult patients (4.9%); Nontuberculous mycobacteria is present in 0.9% and 0.3% of adult and paediatric patients, respectively; Stenotrophomonas maltophilia infection is present in 4.6% of patients (both adults and paediatric). 10. Mortality - RIFC data show that 176 patients (median age 32 years; 81 males and 95 females) died in the period 2011-2014. The present Report shows that CF population is growing (median age), so paediatric mortality is decreasing. A very low percentage of paediatric population is characterized by complication of pulmonary functions; adult patients are characterized by an increase of age at death (more than 30 years of age). ICFR Report may represent an important tool to analyze clinical and epidemiological trends of the disease as well as to identify the main healthcare needs at regional and national level to contribute to the healthcare programmes and to the distribution of the resources.

Animal models of gastrointestinal and liver diseases. Animal models of cystic fibrosis: gastrointestinal, pancreatic, and hepatobiliary disease and pathophysiology

PubMed Central

Olivier, Alicia K.; Gibson-Corley, Katherine N.

2015-01-01

Multiple organ systems, including the gastrointestinal tract, pancreas, and hepatobiliary systems, are affected by cystic fibrosis (CF). Many of these changes begin early in life and are difficult to study in young CF patients. Recent development of novel CF animal models has expanded opportunities in the field to better understand CF pathogenesis and evaluate traditional and innovative therapeutics. In this review, we discuss manifestations of CF disease in gastrointestinal, pancreatic, and hepatobiliary systems of humans and animal models. We also compare the similarities and limitations of animal models and discuss future directions for modeling CF. PMID:25591863

Organization of Patient Management and Fungal Epidemiology in Cystic Fibrosis.

PubMed

Schwarz, Carsten; Bouchara, Jean-Philippe; Buzina, Walter; Chrenkova, Vanda; Dmeńska, Hanna; de la Pedrosa, Elia Gomez Garcia; Cantón, Rafael; Fiscarelli, Ersilia; Le Govic, Yohann; Kondori, Nahid; Matos, Tadeja; Romanowska, Ewa; Ziesing, Stefan; Sedlacek, Ludwig

2018-02-01

The achievement of a better life for cystic fibrosis (CF) patients is mainly caused by a better management and infection control over the last three decades. Herein, we want to summarize the cornerstones for an effective management of CF patients and to give an overview of the knowledge about the fungal epidemiology in this clinical context in Europe. Data from a retrospective analysis encompassing 66,616 samples from 3235 CF patients followed-up in 9 CF centers from different European countries are shown.

Hypertonic saline for cystic fibrosis: worth its salt?

PubMed

Goralski, Jennifer L; Donaldson, Scott H

2014-06-01

Airway dehydration in cystic fibrosis (CF) leads to chronic inflammation, ongoing infection and progressive lung disease. Restoration of airway hydration by inhalation of an osmotic agent (hypertonic saline) has been shown to be safe, effective and well-tolerated in adults with CF. Although the safety of hypertonic saline in infants and young children with CF has also been established, recent studies have reported inconclusive evidence about its efficacy. In this editorial, we discuss the evidence behind hypertonic saline use for adults, children and infants with CF.

Dental enamel defects in Italian children with cystic fibrosis: an observational study.

PubMed

Ferrazzano, G F; Sangianantoni, G; Cantile, T; Amato, I; Orlando, S; Ingenito, A

2012-03-01

The relationship between cystic fibrosis (CF) and caries experience has already been explored, but relatively little information is available on dental enamel defects prevalence among children affected by cystic fibrosis. The aim of this study was to investigate this issue in deciduous and permanent teeth of children with CF resident in southern Italy. This cross sectional observational study was undertaken between October 2009 and March 2010. 88 CF patients and 101 healthy age-matched participated in this study. The prevalence of dental enamel defects was calculated using a modified Developmental Defects of Enamel (DDE) index. The comparison of dental enamel defects prevalence among groups was carried out using regression binary logistic analysis. In the CF subjects there was a higher prevalence (56%) of enamel defects in comparison to the healthy group (22%). The most prevalent enamel defect was hypoplasia with loss of enamel (23% of CF patients vs 1 1/2% of control group) in permanent teeth. This study confirms that children with cystic fibrosis are at increased risk of developing hypoplastic defects on their permanent teeth.

CFTR-dependent defect in alternatively-activated macrophages in cystic fibrosis.

PubMed

Tarique, Abdullah A; Sly, Peter D; Holt, Patrick G; Bosco, Anthony; Ware, Robert S; Logan, Jayden; Bell, Scott C; Wainwright, Claire E; Fantino, Emmanuelle

2017-07-01

The role of the macrophages in cystic fibrosis (CF) lung disease has been poorly studied. We hypothesized that alternatively activated M2 macrophages are abnormal in CF lung disease. Blood samples were collected from adults (n=13) children (n=27) with CF on admission for acute pulmonary exacerbation and when clinically stable. Monocytes were differentiated into macrophages and polarized into classical (M1) and alternatively-activated (M2) phenotypes, function determined ex-vivo and compared with healthy controls. In the absence of functional cystic fibrosis trans-membrane conductance regulator (CFTR), either naturally in patients with CF or induced with CFTR inhibitors, monocyte-derived macrophages do not respond to IL-13/IL-4, fail to polarize into M2s associated with a post-transcriptional failure to produce and express IL-13Rα1 on the macrophage surface Polarization to the M1 phenotype was unaffected. CFTR-dependent imbalance of macrophage phenotypes and functions could contribute to the exaggerated inflammatory response seen in CF lung disease. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Optical Coherence Tomography Identifies Lower Labial Salivary Gland Surface Density in Cystic Fibrosis

PubMed Central

Nowak, Jan K.; Grulkowski, Ireneusz; Karnowski, Karol; Wojtkowski, Maciej; Walkowiak, Jaroslaw

2015-01-01

The labial minor salivary glands (LSGs) are easily accessible mucus-secreting structures of the alimentary tract that may provide new information on the basis of gastrointestinal complications of cystic fibrosis (CF). It was shown that they are destructed in the course of cystic fibrosis. We employed wide-field, micrometer resolution in vivo optical coherence tomography to assess the surface density of LSGs in 18 patients with CF and 18 healthy subjects. The median LSGs’ surface densities in CF patients, and in the control group were 4.32 glands/cm2 and 6.58 glands/cm2, respectively (p = 0.006; Mann-Whitney U test). A lower LSG surface density is a previously unrecognized CF-related pathology of the alimentary tract. PMID:25622042

What Deficits in Sexual and Reproductive Health Knowledge Exist among Women with Cystic Fibrosis? A Systematic Review

ERIC Educational Resources Information Center

Gage, L. Ashley

2012-01-01

The life span of patients with cystic fibrosis (CF) continues to extend due to advances in treatments and care. The rate of pregnancy for female patients with CF has also continued to rise. The purpose of this study was to systematically review the available literature on female patients with CF and their knowledge of sexual and reproductive…

Immune response, diagnosis and treatment of allergic bronchopulmonary aspergillosis in cystic fibrosis lung disease.

PubMed

Eickmeier, Olaf; Rieber, Nikolaus; Eckrich, Jonas; Hector, Andreas; Graeppler-Mainka, Ute; Hartl, Dominik

2013-01-01

Patients with cystic fibrosis (CF) suffer from chronic infective lung disease, which determines morbidity and mortality. While bacteria, such as Pseudomonas aeruginosa, are well-known to contribute to pulmonary pathology, the relevance of fungi in CF airways remains poorly understood. The best studied fungus in CF is Aspergillus fumigatus, which frequently colonizes CF airways and causes a disease condition termed allergic bronchopulmonary aspergillosis. This review aims to provide an update on the immunological mechanisms, diagnostic approaches and therapeutic strategies for allergic bronchopulmonary aspergillosis and other Aspergillus fumigatusmediated phenotypes in CF lung disease.

Glucosylceramide Critically Contributes to the Host Defense of Cystic Fibrosis Lungs.

PubMed

Kovacic, Barbara; Sehl, Carolin; Wilker, Barbara; Kamler, Markus; Gulbins, Erich; Becker, Katrin Anne

2017-01-01

Cystic fibrosis (CF) is the most common autosomal-recessive disorder in western countries. Previous studies have demonstrated an important role of sphingolipids in the pathophysiology of cystic fibrosis. It has been shown that ceramide has a central role in various pulmonary infections, including those with Pseudomonas aeruginosa (P. aeruginosa). Ceramide is accumulated in the airways of CF mice and patients. However, little is known about a potential role of glucosylceramide in cystic fibrosis. We investigated the expression of glucosylceramide and lactosylceramide in the respiratory tract of murine and human CF samples by immunohistochemistry and analyzed effects of glucosylceramide on P. aeruginosa in vitro. We performed pulmonary infections with P. aeruginosa and tested inhalation with glucosylceramide. We demonstrate that glucosylceramide is down-regulated on the apical surface of bronchial and tracheal epithelial cells in cystic fibrosis mice. Although glucosylceramide did not have a direct bactericidal effect on Pseudomonas aeruginosa in vitro, inhalation of CF mice with glucosylceramide protected these mice from infection with P. aeruginosa, while non-inhaled CF mice developed severe pneumonia. Our data suggest that glucosylceramide acts in vivo in concert with ceramide and sphingosine to determine the pulmonary defense against P. aeruginosa. © 2017 The Author(s)Published by S. Karger AG, Basel.

Powerful tools for genetic modification: Advances in gene editing.

PubMed

Roesch, Erica A; Drumm, Mitchell L

2017-11-01

Recent discoveries and technical advances in genetic engineering, methods called gene or genome editing, provide hope for repairing genes that cause diseases like cystic fibrosis (CF) or otherwise altering a gene for therapeutic benefit. There are both hopes and hurdles with these technologies, with new ideas emerging almost daily. Initial studies using intestinal organoid cultures carrying the common, F508del mutation have shown that gene editing by CRISPR/Cas9 can convert cells lacking CFTR function to cells with normal channel function, providing a precedent that this technology can be harnessed for CF. While this is an important precedent, the challenges that remain are not trivial. A logistical issue for this and many other genetic diseases is genetic heterogeneity. Approximately, 2000 mutations associated with CF have been found in CFTR, the gene responsible for CF, and thus a feasible strategy that would encompass all individuals affected by the disease is particularly difficult to envision. However, single strategies that would be applicable to all subjects affected by CF have been conceived and are being investigated. With all of these approaches, efficiency (the proportion of cells edited), accuracy (how often other sites in the genome are affected), and delivery of the gene editing components to the desired cells are perhaps the most significant, impending hurdles. Our understanding of each of these areas is increasing rapidly, and while it is impossible to predict when a successful strategy will reach the clinic, there is every reason to believe it is a question of "when" and not "if." © 2017 Wiley Periodicals, Inc.

Aspergillus fumigatus Preexposure Worsens Pathology and Improves Control of Mycobacterium abscessus Pulmonary Infection in Mice.

PubMed

Monin, Leticia; Mehta, Shail; Elsegeiny, Waleed; Gopal, Radha; McAleer, Jeremy P; Oury, Tim D; Kolls, Jay; Khader, Shabaana A

2018-03-01

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Mutations in this chloride channel lead to mucus accumulation, subsequent recurrent pulmonary infections, and inflammation, which, in turn, cause chronic lung disease and respiratory failure. Recently, rates of nontuberculous mycobacterial (NTM) infections in CF patients have been increasing. Of particular relevance is infection with Mycobacterium abscessus , which causes a serious, life-threatening disease and constitutes one of the most antibiotic-resistant NTM species. Interestingly, an increased prevalence of NTM infections is associated with worsening lung function in CF patients who are also coinfected with Aspergillus fumigatus We established a new mouse model to investigate the relationship between A. fumigatus and M. abscessus pulmonary infections. In this model, animals exposed to A. fumigatus and coinfected with M. abscessus exhibited increased lung inflammation and decreased mycobacterial burden compared with those of mice infected with M. abscessus alone. This increased control of M. abscessus infection in coinfected mice was mucus independent but dependent on both transcription factors T-box 21 (Tbx21) and retinoic acid receptor (RAR)-related orphan receptor gamma t (RORγ-t), master regulators of type 1 and type 17 immune responses, respectively. These results implicate a role for both type 1 and type 17 responses in M. abscessus control in A. fumigatus -coinfected lungs. Our results demonstrate that A. fumigatus , an organism found commonly in CF patients with NTM infection, can worsen pulmonary inflammation and impact M. abscessus control in a mouse model. Copyright © 2018 American Society for Microbiology.

Non-Invasive Evaluation of Cystic Fibrosis Related Liver Disease in Adults with ARFI, Transient Elastography and Different Fibrosis Scores

PubMed Central

Oltmanns, Annett; Güttler, Andrea; Petroff, David; Wirtz, Hubert; Mainz, Jochen G.; Mössner, Joachim; Berg, Thomas; Tröltzsch, Michael; Keim, Volker; Wiegand, Johannes

2012-01-01

Background Cystic fibrosis-related liver disease (CFLD) is present in up to 30% of cystic fibrosis patients and can result in progressive liver failure. Diagnosis of CFLD is challenging. Non-invasive methods for staging of liver fibrosis display an interesting diagnostic approach for CFLD detection. Aim We evaluated transient elastography (TE), acoustic radiation force impulse imaging (ARFI), and fibrosis indices for CFLD detection. Methods TE and ARFI were performed in 55 adult CF patients. In addition, AST/Platelets-Ratio-Index (APRI), and Forns' score were calculated. Healthy probands and patients with alcoholic liver cirrhosis served as controls. Results Fourteen CF patients met CFLD criteria, six had liver cirrhosis. Elastography acquisition was successful in >89% of cases. Non-cirrhotic CFLD individuals showed elastography values similar to CF patients without liver involvement. Cases with liver cirrhosis differed significantly from other CFLD patients (ARFI: 1.49 vs. 1.13 m/s; p = 0.031; TE: 7.95 vs. 4.16 kPa; p = 0.020) and had significantly lower results than individuals with alcoholic liver cirrhosis (ARFI: 1.49 vs. 2.99 m/s; p = 0.002). APRI showed the best diagnostic performance for CFLD detection (AUROC 0.815; sensitivity 85.7%, specificity 70.7%). Conclusions ARFI, TE, and laboratory based fibrosis indices correlate with each other and reliably detect CFLD related liver cirrhosis in adult CF patients. CF specific cut-off values for cirrhosis in adults are lower than in alcoholic cirrhosis. PMID:22848732

Exocrine cell-derived microparticles in response to lipopolysaccharide promote endocrine dysfunction in cystic fibrosis.

PubMed

Constantinescu, Andrei Alexandru; Gleizes, Céline; Alhosin, Mahmoud; Yala, Elhassan; Zobairi, Fatiha; Leclercq, Alexandre; Stoian, Gheorghe; Mitrea, Ioan Liviu; Prévost, Gilles; Toti, Florence; Kessler, Laurence

2014-03-01

Diabetes in cystic fibrosis (CF) is a result of exocrine pancreas alteration followed by endocrine dysfunction at a later stage. Microparticles (MPs) are plasma membrane fragments shed from stimulated or damaged cells that act as cellular effectors. Our aim was to identify a new form of interaction between exocrine and endocrine pancreatic cells mediated by exocrine MPs, in the context of recurrent infection in CF. MPs from either human exocrine CFTRΔF508-mutated (CFPAC-1) cells or exocrine normal pancreatic (PANC-1) cells were collected after treatment by LPS from Pseudomonas aeruginosa and applied to rat endocrine normal insulin-secreting RIN-m5F cells. MP membrane integration in target cells was established by confocal microscopy and flow cytometry using PKH26 lipid probe. Apoptosis, lysosomal activity, insulin secretion were measured after 18 h. MP-mediated NF-κB activation was measured in HEK-Blue reporter cells by SEAP reporter gene system and in RIN-m5F cells by Western blot. In endocrine normal cells, CFTR inhibition was achieved using Inhibitor-172. Compared to PANC-1, MPs from CFPAC-1 significantly reduced insulin secretion and lysosomal activity in RIN-m5F. MPs induced NF-κB activation by increasing the level of IκB phosphorylation. Moreover, the inhibition of NF-κB activation using specific inhibitors was associated with a restored insulin secretion. Interestingly, CFTR inhibition in normal RIN-m5F cells promoted apoptosis and decreased insulin secretion. During recurrent infections associated with CF, exocrine MPs may contribute to endocrine cell dysfunction via NF-κB pathways. Membrane CFTR dysfunction is associated with decreased insulin secretion. © 2013. Published by Elsevier B.V. on behalf of European Cystic Fibrosis Society. All rights reserved.

Aspergillus infections in cystic fibrosis.

PubMed

King, Jill; Brunel, Shan F; Warris, Adilia

2016-07-05

Patients with cystic fibrosis (CF) suffer from chronic lung infection and airway inflammation. Respiratory failure secondary to chronic or recurrent infection remains the commonest cause of death and accounts for over 90% of mortality. Bacteria as Staphylococcus aureus, Pseudomonas aeruginosa and Burkholderia cepacia complex have been regarded the main CF pathogens and their role in progressive lung decline has been studied extensively. Little attention has been paid to the role of Aspergillus spp. and other filamentous fungi in the pathogenesis of non-ABPA (allergic bronchopulmonary aspergillosis) respiratory disease in CF, despite their frequent recovery in respiratory samples. It has become more apparent however, that Aspergillus spp. may play an important role in chronic lung disease in CF. Research delineating the underlying mechanisms of Aspergillus persistence and infection in the CF lung and its link to lung deterioration is lacking. This review summarizes the Aspergillus disease phenotypes observed in CF, discusses the role of CFTR (cystic fibrosis transmembrane conductance regulator)-protein in innate immune responses and new treatment modalities. Copyright © 2016. Published by Elsevier Ltd.

Increase in interleukin-8 production from circulating neutrophils upon antibiotic therapy in cystic fibrosis patients.

PubMed

Montemurro, Pasqualina; Mariggiò, Maria A; Barbuti, Giovanna; Cassano, Amalia; Vincenti, Alessandra; Serio, Gabriella; Guerra, Lorenzo; Diana, Anna; Santostasi, Teresa; Polizzi, Angela; Fumarulo, Ruggiero; Casavola, Valeria; Manca, Antonio; Conese, Massimo

2012-12-01

It is not known whether antibiotic therapy for lung disease in cystic fibrosis (CF) has an influence on circulating polymorphonuclear neutrophil (PMN) function and apoptosis. Blood PMNs were obtained from 14 CF patients before and after antibiotic treatment for an acute exacerbation, and from 10 healthy controls. PMNs were evaluated for production of reactive oxygen species (ROS) by spectrophotometry, of cytokines in the conditioned medium by ELISA, and apoptotic response by cytofluorimetry. ROS and interleukin (IL)-8 were produced at higher levels by CF PMNs pre-therapy than control PMNs under basal conditions. IL-8 levels further increased after therapy. Early apoptotic response was higher in CF PMNs pre-therapy than in control PMNs, and this pattern did not change after antibiotic treatment. Circulating PMNs are primed in CF acute patients. Further studies are needed to consider PMN-produced IL-8 as a biomarker to evaluate response to antibiotic therapy in CF patients. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

High incidence of non-tuberculous mycobacteria-positive cultures among adolescent with cystic fibrosis.

PubMed

Cavalli, Zoé; Reynaud, Quitterie; Bricca, Romain; Nove-Josserand, Raphaële; Durupt, Stéphane; Reix, Philippe; Perceval, Marie; de Montclos, Michèle Pérouse; Lina, Gérard; Durieu, Isabelle

2017-09-01

We evaluated the prevalence of non-tuberculous mycobacteria (NTM)-positive cultures among our cystic fibrosis (CF) center patients, reviewed risk factors for NTM positivity, and determined its impact on lung function evolution. From 2009 to 2014, CF adults and children attending the CF center of Lyon (France) and having at least one positive NTM isolate were included. Each case was matched by age and gender with two CF patients with no NTM isolate (controls). 48 CF patients with NTM-positive isolates were matched to 96 controls. The age group for whom incident NTM was higher was young adolescents aged 13 to 17. A significant association for NTM positivity was found with Staphylococcusaureus in multivariate analysis and with allergic bronchopulmonary aspergillosis, corticosteroid and itraconazole in univariate analysis. Mean annual FEV1 decline was faster for NTM-positive patients compared to controls. These data highlight the high incidence of NTM-positive cultures among young adolescents with CF. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Epidemiology and genetics of cystic fibrosis in Asia: In preparation for the next-generation treatments.

PubMed

Singh, Meenu; Rebordosa, Cristina; Bernholz, Juliane; Sharma, Neeraj

2015-11-01

Cystic fibrosis (CF) in the Asian population is less frequently reported due to under-diagnosis and lack of centralized CF patient registries. Clinical studies on CF cases from Asia have documented a severe course of the disease. The spectrum of the cystic fibrosis transmembrane conductance regulator (CFTR) variants in this population is quite heterogeneous. In total, 166 variants have been reported on approximately 3700 Asian CF chromosomes. The frequency of F508del among Asians is low compared with Caucasians. Recent in vitro studies have shown promise of small molecule correction and potentiation of 45 different CFTR variants. Of these variants, 16 (including G551D and F508del) have also been observed among Asian CF individuals. We suggest undertaking molecular studies extensively to annotate CFTR variants that will help Asian CF individuals to benefit from the precision medicine gaining momentum in the Western countries. © 2015 Asian Pacific Society of Respirology.

Exhaled molecular profiles in the assessment of cystic fibrosis and primary ciliary dyskinesia.

PubMed

Paff, T; van der Schee, M P; Daniels, J M A; Pals, G; Postmus, P E; Sterk, P J; Haarman, E G

2013-09-01

Early diagnosis and monitoring of disease activity are essential in cystic fibrosis (CF) and primary ciliary dyskinesia (PCD). We aimed to establish exhaled molecular profiles as the first step in assessing the potential of breath analysis. Exhaled breath was analyzed by electronic nose in 25 children with CF, 25 with PCD and 23 controls. Principle component reduction and canonical discriminant analysis were used to construct internally cross-validated ROC curves. CF and PCD patients had significantly different breath profiles when compared to healthy controls (CF: sensitivity 84%, specificity 65%; PCD: sensitivity 88%, specificity 52%) and from each other (sensitivity 84%, specificity 60%). Patients with and without exacerbations had significantly different breath profiles (CF: sensitivity 89%, specificity 56%; PCD: sensitivity 100%, specificity 90%). Exhaled molecular profiles significantly differ between patients with CF, PCD and controls. The eNose may have potential in disease monitoring based on the influence of exacerbations on the VOC-profile. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Deleterious impact of hyperglycemia on cystic fibrosis airway ion transport and epithelial repair.

PubMed

Bilodeau, Claudia; Bardou, Olivier; Maillé, Émilie; Berthiaume, Yves; Brochiero, Emmanuelle

2016-01-01

Cystic fibrosis (CF)-related diabetes (CFRD) is associated with faster pulmonary function decline. Thus, we evaluated the impact of hyperglycemia on airway epithelial repair and transepithelial ion transport, which are critical in maintaining lung integrity and function. Non-CF and CF airway epithelial cells were exposed to low (LG) or high (HG) glucose before ion current and wound repair rate measurements. CFTR and K+ currents decreased after HG treatments. HG also reduced the wound healing rates of non-CF and CF cell monolayers. Although CFTR correction with VRT-325 accelerated the healing rates of CF cells monolayers under LG conditions, this improvement was significantly abrogated under HG conditions. Our data highlights a deleterious impact of hyperglycemia on ion transport and epithelial repair functions, which could contribute to the deterioration in lung function in CFRD patients. HG may also interfere with the beneficial effects of CFTR rescue on airway epithelial repair. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Relationship Between Fat-Soluble Vitamin Supplementation and Blood Concentrations in Adolescent and Adult Patients With Cystic Fibrosis.

PubMed

Siwamogsatham, Oranan; Dong, Wei; Binongo, Jose N; Chowdhury, Ritam; Alvarez, Jessica A; Feinman, Shawna J; Enders, Jessica; Tangpricha, Vin

2014-08-01

Background: Pancreatic insufficiency is common in patients with cystic fibrosis (CF) and leads to malabsorption of fat-soluble vitamins. Multivitamins, including vitamins A, D, E, and K, are routinely prescribed to patients with CF to prevent vitamin deficiencies. Our objective was to examine the relationship between fat-soluble vitamin supplements and their impact on blood concentrations. Methods: This was a retrospective chart review of patients with CF who were treated at Emory Clinic and Emory University Hospital during 2008-2012. The amount of fat-soluble vitamin supplementation, serum markers of fat-soluble vitamin concentrations, CF transmembrane conductance regulator genotype, and other demographic information were recorded from electronic medical records. Mixed-effects models were used to investigate the trends over time of fat-soluble vitamin supplements and serum vitamin concentrations. Results: In total, 177 charts were eligible. Mean (SD) age was 26.1 (10.2) years. Ninety-two percent of patients had pancreatic insufficiency and 52% had the homozygous ΔF508 mutation. Recorded fat-soluble vitamin supplementation increased in the past 5 years (P < .001 for all). Serum 25-hydroxyvitamin D increased slightly (3% increase; P < .01); however, there were no changes in the blood concentrations of vitamins A, E, and K (P = .26-.96). Conclusions: Despite a near doubling of recorded fat-soluble vitamin supplementation over the past 5 years, there was no parallel increase in blood concentrations of these vitamins. Potential reasons include suboptimal dosages, low adherence, or ongoing issues with malabsorption. © 2014 American Society for Parenteral and Enteral Nutrition.

Hallmarks of Therapeutic Management of the Cystic Fibrosis Functional Landscape

PubMed Central

Amaral, Margarida D.; Balch, William E.

2015-01-01

The cystic fibrosis (CF) transmembrane conductance regulator (CFTR) protein does not operate in isolation, rather in a dynamic network of interacting components that impact its synthesis, folding, stability, intracellular location and function, referred to herein as the ‘CFTR Functional Landscape (CFFL)’. For the prominent F508del mutation, many of these interactors are deeply connected to a protein fold management system, the proteostasis network (PN). However, CF encompasses an additional 2000 CFTR variants distributed along its entire coding sequence (referred to as CFTR2), and each variant contributes a differential liability to PN management of CFTR and to a protein ‘Social Network’ (SN) that directs the probability of the (patho)physiologic events that impact ion transport in each cell, tissue and patient in health and disease. Recognition of the importance of the PN and SN in driving the unique patient CFFL leading to disease highlights the importance of precision medicine in therapeutic management of disease progression. We take the view herein that it is not CFTR, rather the PN/SN, and their impact on the CFFL, that are the key physiologic forces driving onset and clinical progression of CF. We posit that a deep understanding of each patients PN/SN gained by merging genomic, proteomic (mass spectrometry (MS)), and high-content microscopy (HCM) technologies in the context of novel network learning algorithms will lead to a paradigm shift in CF clinical management. This should allow for generation of new classes of patient specific PN/SN directed therapeutics for personalized management of the CFFL in the clinic. PMID:26526359

Personalized or Precision Medicine? The Example of Cystic Fibrosis

PubMed Central

Marson, Fernando A. L.; Bertuzzo, Carmen S.; Ribeiro, José D.

2017-01-01

The advent of the knowledge on human genetics, by the identification of disease-associated variants, culminated in the understanding of human variability. With the genetic knowledge, the specificity of the clinical phenotype and the drug response of each individual were understood. Using the cystic fibrosis (CF) as an example, the new terms that emerged such as personalized medicine and precision medicine can be characterized. The genetic knowledge in CF is broad and the presence of a monogenic disease caused by mutations in the CFTR gene enables the phenotype–genotype association studies (including the response to drugs), considering the wide clinical and laboratory spectrum dependent on the mutual action of genotype, environment, and lifestyle. Regarding the CF disease, personalized medicine is the treatment directed at the symptoms, and this treatment is adjusted depending on the patient’s phenotype. However, more recently, the term precision medicine began to be widely used, although its correct application and understanding are still vague and poorly characterized. In precision medicine, we understand the individual as a response to the interrelation between environment, lifestyle, and genetic factors, which enabled the advent of new therapeutic models, such as conventional drugs adjustment by individual patient dosage and drug type and response, development of new drugs (read through, broker, enhancer, stabilizer, and amplifier compounds), genome editing by homologous recombination, zinc finger nucleases, TALEN (transcription activator-like effector nuclease), CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR-associated endonuclease 9), and gene therapy. Thus, we introduced the terms personalized medicine and precision medicine based on the CF. PMID:28676762

Dual core quantum dots for highly quantitative ratiometric detection of trypsin activity in cystic fibrosis patients

NASA Astrophysics Data System (ADS)

Castelló Serrano, Iván; Stoica, Georgiana; Matas Adams, Alba; Palomares, Emilio

2014-10-01

We present herein two colour encoded silica nanospheres (2nanoSi) for the fluorescence quantitative ratiometric determination of trypsin in humans. Current detection methods for cystic fibrosis diagnosis are slow, costly and suffer from false positives. The 2nanoSi proved to be a highly sensitive, fast (minutes), and single-step approach nanosensor for the screening and diagnosis of cystic fibrosis, allowing the quantification of trypsin concentrations in a wide range relevant for clinical applications (25-350 μg L-1). Furthermore, as trypsin is directly related to the development of cystic fibrosis (CF), different human genotypes, i.e. CF homozygotic, CF heterozygotic, and unaffected, respectively, can be determined using our 2nanoSi nanospheres. We anticipate the 2nanoSi system to be a starting point for non-invasive, easy-to-use and cost effective ratiometric fluorescent biomarkers for recessive genetic diseases like human cystic fibrosis. In a screening program in which the goal is to detect disease and also the carrier status, early diagnosis could be of great help.We present herein two colour encoded silica nanospheres (2nanoSi) for the fluorescence quantitative ratiometric determination of trypsin in humans. Current detection methods for cystic fibrosis diagnosis are slow, costly and suffer from false positives. The 2nanoSi proved to be a highly sensitive, fast (minutes), and single-step approach nanosensor for the screening and diagnosis of cystic fibrosis, allowing the quantification of trypsin concentrations in a wide range relevant for clinical applications (25-350 μg L-1). Furthermore, as trypsin is directly related to the development of cystic fibrosis (CF), different human genotypes, i.e. CF homozygotic, CF heterozygotic, and unaffected, respectively, can be determined using our 2nanoSi nanospheres. We anticipate the 2nanoSi system to be a starting point for non-invasive, easy-to-use and cost effective ratiometric fluorescent biomarkers for recessive genetic diseases like human cystic fibrosis. In a screening program in which the goal is to detect disease and also the carrier status, early diagnosis could be of great help. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03952a

FOXO1 content is reduced in cystic fibrosis and increases with IGF-I treatment.

PubMed

Smerieri, Arianna; Montanini, Luisa; Maiuri, Luigi; Bernasconi, Sergio; Street, Maria E

2014-10-08

Cystic fibrosis-related diabetes is to date the most frequent complication in cystic fibrosis (CF). The mechanisms underlying this condition are not well understood, and a possible role of insulin resistance is debated. We investigated insulin signal transduction in CF. Total insulin receptor, IRS1, p85 PI3K, and AKT contents were substantially normal in CF cells (CFBE41o-), whereas winged helix forkhead (FOX)O1 contents were reduced both in baseline conditions and after insulin stimulation. In addition, CF cells showed increased ERK1/2, and reduced β2 arrestin contents. No significant change in SOCS2 was observed. By using a CFTR inhibitor and siRNA, changes in FOXO1 were related to CFTR loss of function. In a CF-affected mouse model, FOXO1 content was reduced in the muscle while no significant difference was observed in liver and adipose tissue compared with wild-type. Insulin-like growth factor 1 (IGF-I) increased FOXO1 content in vitro and in vivo in muscle and adipose tissue. In conclusion; we present the first description of reduced FOXO1 content in CF, which is compatible with reduced gluconeogenesis and increased adipogenesis, both features of insulin insensitivity. IGF-I treatment was effective in increasing FOXO1, thereby suggesting that it could be considered as a potential treatment in CF patients possibly to prevent and treat cystic fibrosis-related diabetes.

Update on host-pathogen interactions in cystic fibrosis lung disease.

PubMed

Hector, Andreas; Frey, Nina; Hartl, Dominik

2016-12-01

Bacterial and fungal infections are hallmarks of cystic fibrosis (CF) lung disease. In the era of long-term inhaled antibiotics and increasing CF patient survival, new "emerging" pathogens are detected in CF airways, yet their pathophysiological disease relevance remains largely controversial and incompletely defined. As a response to chronic microbial triggers, innate immune cells, particularly neutrophils, are continuously recruited into CF airways where they combat pathogens but also cause tissue injury through release of oxidants and proteases. The coordinated interplay between host immune cell activation and pathogens is essential for the outcome of CF lung disease. Here, we provide a concise overview and update on host-pathogen interactions in CF lung disease.

Association between body composition and pulmonary function in children and young people with cystic fibrosis.

PubMed

Calella, Patrizia; Valerio, Giuliana; Thomas, Matt; McCabe, Helen; Taylor, Jake; Brodlie, Malcolm; Siervo, Mario

2018-04-01

Body mass index (BMI) has significant limitations when assessing nutritional status in pediatric patients with cystic fibrosis (CF). We evaluated whether measurements of lean body mass (LBM) and fat mass (FM) are more sensitive nutritional parameters by testing their association with pulmonary function in adolescent patients with CF. Sixty-nine male and female adolescents with CF were studied (age: 14.5 ± 2.3, BMI: 19.5 ± 2.3 kg/m 2 ). Dual-energy x-ray absorptiometry (DXA) was used to measure total and segmental (appendicular, truncal) body composition (FM, LBM bone mineral density, and content) as routine care to monitor bone health. Correlation and multiple regression analyses were performed to assess the association among body composition variables and forced expiratory volume in 1 s (FEV 1 ). We also evaluated the influence of the F508del mutation on body composition. FEV 1 was significantly associated with total (r = 0.68, P <0.001), truncal (r = 0.71, P <0.001), and appendicular (r = 0.67, P <0.001) LBM, whereas it was not associated with total (r = 0.02, P = 0.89) and truncal (r = 0.04, P = 0.77) FM. BMI had a significant but weaker correlation with FEV 1 (r = 0.52, P <0.001) compared with LBM. LBM was the only significant predictor of FEV 1 in fully adjusted regression models. LBM is a significant predictor of pulmonary function in CF adolescent patients. DXA scanning performed as part of routine bone health monitoring in CF can provide important body composition data relevant to clinical interventions that optimize nutritional status. DXA reference data for LBM in non-adult populations are needed to enhance diagnostic assessment and monitor clinical progression of CF. Copyright © 2017 Elsevier Inc. All rights reserved.

Pseudomonas aeruginosa AES-1 exhibits increased virulence gene expression during chronic infection of cystic fibrosis lung.

PubMed

Naughton, Sharna; Parker, Dane; Seemann, Torsten; Thomas, Torsten; Turnbull, Lynne; Rose, Barbara; Bye, Peter; Cordwell, Stuart; Whitchurch, Cynthia; Manos, Jim

2011-01-01

Pseudomonas aeruginosa, the leading cause of morbidity and mortality in people with cystic fibrosis (CF), adapts for survival in the CF lung through both mutation and gene expression changes. Frequent clonal strains such as the Australian Epidemic Strain-1 (AES-1), have increased ability to establish infection in the CF lung and to superimpose and replace infrequent clonal strains. Little is known about the factors underpinning these properties. Analysis has been hampered by lack of expression array templates containing CF-strain specific genes. We sequenced the genome of an acute infection AES-1 isolate from a CF infant (AES-1R) and constructed a non-redundant micro-array (PANarray) comprising AES-1R and seven other sequenced P. aeruginosa genomes. The unclosed AES-1R genome comprised 6.254Mbp and contained 6957 putative genes, including 338 not found in the other seven genomes. The PANarray contained 12,543 gene probe spots; comprising 12,147 P. aeruginosa gene probes, 326 quality-control probes and 70 probes for non-P. aeruginosa genes, including phage and plant genes. We grew AES-1R and its isogenic pair AES-1M, taken from the same patient 10.5 years later and not eradicated in the intervening period, in our validated artificial sputum medium (ASMDM) and used the PANarray to compare gene expression of both in duplicate. 675 genes were differentially expressed between the isogenic pairs, including upregulation of alginate, biofilm, persistence genes and virulence-related genes such as dihydroorotase, uridylate kinase and cardiolipin synthase, in AES-1M. Non-PAO1 genes upregulated in AES-1M included pathogenesis-related (PAGI-5) genes present in strains PACS2 and PA7, and numerous phage genes. Elucidation of these genes' roles could lead to targeted treatment strategies for chronically infected CF patients.

Pseudomonas aeruginosa AES-1 Exhibits Increased Virulence Gene Expression during Chronic Infection of Cystic Fibrosis Lung

PubMed Central

Naughton, Sharna; Parker, Dane; Seemann, Torsten; Thomas, Torsten; Turnbull, Lynne; Rose, Barbara; Bye, Peter; Cordwell, Stuart; Whitchurch, Cynthia; Manos, Jim

2011-01-01

Pseudomonas aeruginosa, the leading cause of morbidity and mortality in people with cystic fibrosis (CF), adapts for survival in the CF lung through both mutation and gene expression changes. Frequent clonal strains such as the Australian Epidemic Strain-1 (AES-1), have increased ability to establish infection in the CF lung and to superimpose and replace infrequent clonal strains. Little is known about the factors underpinning these properties. Analysis has been hampered by lack of expression array templates containing CF-strain specific genes. We sequenced the genome of an acute infection AES-1 isolate from a CF infant (AES-1R) and constructed a non-redundant micro-array (PANarray) comprising AES-1R and seven other sequenced P. aeruginosa genomes. The unclosed AES-1R genome comprised 6.254Mbp and contained 6957 putative genes, including 338 not found in the other seven genomes. The PANarray contained 12,543 gene probe spots; comprising 12,147 P. aeruginosa gene probes, 326 quality-control probes and 70 probes for non-P. aeruginosa genes, including phage and plant genes. We grew AES-1R and its isogenic pair AES-1M, taken from the same patient 10.5 years later and not eradicated in the intervening period, in our validated artificial sputum medium (ASMDM) and used the PANarray to compare gene expression of both in duplicate. 675 genes were differentially expressed between the isogenic pairs, including upregulation of alginate, biofilm, persistence genes and virulence-related genes such as dihydroorotase, uridylate kinase and cardiolipin synthase, in AES-1M. Non-PAO1 genes upregulated in AES-1M included pathogenesis-related (PAGI-5) genes present in strains PACS2 and PA7, and numerous phage genes. Elucidation of these genes' roles could lead to targeted treatment strategies for chronically infected CF patients. PMID:21935417

Facilitating Positive Psychosocial Adaptation in Children with Cystic Fibrosis by Increasing Family Communication and Problem-Solving Skills. A Research Report to the Cystic Fibrosis Foundation.

ERIC Educational Resources Information Center

Stabler, Brian; And Others

This study tested the effects of two group-oriented supportive and educational approaches on the parents of children with cystic fibrosis (CF). Thirteen families were randomly assigned either to a group which received information on medical and technical aspects of CF or to a group which received instruction in communication skills in addition to…

[Italian Cystic Fibrosis Register - Report 2010].

PubMed

Amato, Annalisa; Ferrigno, Luigina; Salvatore, Marco; Toccaceli, Virgilia

2016-01-01

The Italian National CF Registry (INCFR) is based on the official agreement between the clinicians of the Italian National Referral Centers for Cystic Fibrosis and the researchers of the Istituto Superiore di Sanità (National Center for Rare Diseases; National Center for Epidemiology, Surveillance and Health Care Promotion). OBJECTIVES The main aim of INCFR is to contribute to the improvement in CF patients health care and clinical management through: i. the estimates of CF prevalence and incidence in Italy; ii. the analyses of medium and long term clinical and epidemiological trends of the disesase; iii. the identification of the main health care needs at regional and national level to contribute to the Health Care programmes and to the distribution of resources. MATERIALS AND METHODS Analyses and results described in the present Report are referred to patients in charge to the Italian National Referral Centers for Cystic Fibrosis in 2010. Data were sent by Centers by means of a specific software (Camilla, Ibis Informatica). The Italian National Referral Centers for Cystic Fibrosis sent a total of 5,271 individual records; 1,112 records were excluded from the analyses due to restricted inclusion criteria. The total number of patients included in INCFR for analyses is 4,159. RESULTS INCFR database includes all prevalent cases at 1th January 2010 as well as all new diagnoses done in 2010. The present Report has been organized into 9 sections. 1. Demography: estimated 2010 CF prevalence was 7/100,000 residents in Italy; 52% of the patients were male, CF distribution showed higher frequency in patients aged 7 to 35 years. In 2010, 48.9% of the patients were more than 18 years old. 2. Diagnoses: most of the CF patients were diagnosed before two years of age (66.7%); a significant percentage of patients (11.4%) was diagnosed in adult-age. 3. New diagnoses (2010): new diagnoses were 168. Sixty-five percent of them was diagnosed before the second year of age and 17%in adulthood. No differences were observed between male and female. Incidence at birth was estimated 1/4,854 living births. 4. in 95.9% of patients, 2 (or more) CFTR mutations were identified. [delta]508F mutation was the most frequent (45.1%). 5. Respiratory function: analyses were performed on 2,966 out of 3,341 patients aged 7 years or older. FEV1 (Forced Expiratory Volume in the first second) scores progressively decreased before adult age, in accordance with the natural history of the disease. 6. Nutrition: most critical periods are during the first 6 months of life and during adolescence. Fourteen per cent of the patients within 2-18 years resulted malnourished. From 18 years onwards, optimal BodyMass Index (BMI) values were detected in 36.5%of males and in 28%of females. BMI also improved during age. 7. Transplantation: in 2010, 20 patients (10 males and 10 females) were bi-pulmunary transplanted; age was comprised between 11 and 46 years, median age at transplantation was 27.5 years. Eleven out of the 20 patients resulted still alive on the 31th December 2010. 8. Microbiology: analyses were performed on 3.272 patients (887 did not report these data) and were exclusively referred to tests performed in 2010. A percentage of 34 patients, younger than 18 years of age, was characterized by the presence of Pseudomonas aeruginosa compared to 61.8% of the older patients. Prevalence of Burkholderia Cepacia was 0.8% in patients aged up to 17 years; in patients aged more than 17 years, prevalence was 6.8%. Staphylococcus aureus meticillino sensitive prevalence was not correlated with patients' age. 9. 34 patients aged from 0 to 45 years died in 2010 (16 males and 18 females). Respiratory insufficiency was the main cause of death (73.5%). CONCLUSIONS The report aims at being an instrument for CF community, with particular attention to the needs of patients and their families. Information collected within INCFR are an important starting point for further studies from health care perspectives. Finally, INCFR represents an important tool to foster research and innovative treatment for CF, as the rareness of the disease is a constraint to clinical trials and other studies set-up. A significant subset of data are regularly sent to the European Registry of Cystic Fibrosis.

Transepithelial nasal potential difference (NPD) measurements in cystic fibrosis (CF).

PubMed

Sands, Dorota

2013-01-01

The main underlying physiologic abnormality in cystic fibrosis (CF) is dysfunction of the CF transmembrane conductance regulator (CFTR), which results in abnormal transport of sodium and chloride across epithelial surfaces. CFTR function could be tested in vivo using measurements of nasal transepithelial potential difference (PD). Nasal measurements show characteristic features of CF epithelia, including hyperpolarized baseline readings (basal PD), excessive depolarization in response to sodium channel inhibitors, such as amiloride (ΔAmiloride), and little or no chloride (Cl-) secretion in response to isoproterenol in a chloride-free solution (ΔCl- free-isoproterenol). PD test is applied for CF diagnosis and monitoring of new therapeutic modulations and corrections.

Endocrine Disorders in Cystic Fibrosis.

PubMed

Blackman, Scott M; Tangpricha, Vin

2016-08-01

Cystic fibrosis is frequently complicated by endocrine disorders. Diabetes can be expected to affect most with CF and pancreatic insufficiency and varies widely in age of onset, but early identification and treatment improve morbidity and mortality. Short stature can be exacerbated by relative delay of puberty and by use of inhaled corticosteroids. Bone disease in CF causes fragility fractures and should be assessed by monitoring bone mineral density and optimizing vitamin D status. Detecting and managing endocrine complications in CF can reduce morbidity and mortality in CF. These complications can be expected to become more common as the CF population ages. Copyright © 2016 Elsevier Inc. All rights reserved.

Advances in Cell and Gene-based Therapies for Cystic Fibrosis Lung Disease

PubMed Central

Oakland, Mayumi; Sinn, Patrick L; McCray Jr, Paul B

2012-01-01

Cystic fibrosis (CF) is a disease characterized by airway infection, inflammation, remodeling, and obstruction that gradually destroy the lungs. Direct delivery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene to airway epithelia may offer advantages, as the tissue is accessible for topical delivery of vectors. Yet, physical and host immune barriers in the lung present challenges for successful gene transfer to the respiratory tract. Advances in gene transfer approaches, tissue engineering, and novel animal models are generating excitement within the CF research field. This review discusses current challenges and advancements in viral and nonviral vectors, cell-based therapies, and CF animal models. PMID:22371844

Reduced β-Cell Secretory Capacity in Pancreatic-Insufficient, but Not Pancreatic-Sufficient, Cystic Fibrosis Despite Normal Glucose Tolerance.

PubMed

Sheikh, Saba; Gudipaty, Lalitha; De Leon, Diva D; Hadjiliadis, Denis; Kubrak, Christina; Rosenfeld, Nora K; Nyirjesy, Sarah C; Peleckis, Amy J; Malik, Saloni; Stefanovski, Darko; Cuchel, Marina; Rubenstein, Ronald C; Kelly, Andrea; Rickels, Michael R

2017-01-01

Patients with pancreatic-insufficient cystic fibrosis (PI-CF) are at increased risk for developing diabetes. We determined β-cell secretory capacity and insulin secretory rates from glucose-potentiated arginine and mixed-meal tolerance tests (MMTTs), respectively, in pancreatic-sufficient cystic fibrosis (PS-CF), PI-CF, and normal control subjects, all with normal glucose tolerance, in order to identify early pathophysiologic defects. Acute islet cell secretory responses were determined under fasting, 230 mg/dL, and 340 mg/dL hyperglycemia clamp conditions. PI-CF subjects had lower acute insulin, C-peptide, and glucagon responses compared with PS-CF and normal control subjects, indicating reduced β-cell secretory capacity and α-cell function. Fasting proinsulin-to-C-peptide and proinsulin secretory ratios during glucose potentiation were higher in PI-CF, suggesting impaired proinsulin processing. In the first 30 min of the MMTT, insulin secretion was lower in PI-CF compared with PS-CF and normal control subjects, and glucagon-like peptide 1 and gastric inhibitory polypeptide were lower compared with PS-CF, and after 180 min, glucose was higher in PI-CF compared with normal control subjects. These findings indicate that despite "normal" glucose tolerance, adolescents and adults with PI-CF have impairments in functional islet mass and associated early-phase insulin secretion, which with decreased incretin responses likely leads to the early development of postprandial hyperglycemia in CF. © 2017 by the American Diabetes Association.

Survival in Patients with Advanced Non-cystic Fibrosis Bronchiectasis Versus Cystic Fibrosis on the Waitlist for Lung Transplantation.

PubMed

Hayes, Don; Kopp, Benjamin T; Tobias, Joseph D; Woodley, Frederick W; Mansour, Heidi M; Tumin, Dmitry; Kirkby, Stephen E

2015-12-01

Survival in non-cystic fibrosis (CF) bronchiectasis is not well studied. The United Network for Organ Sharing database was queried from 1987 to 2013 to compare survival in adult patients with non-CF bronchiectasis to patients with CF listed for lung transplantation (LTx). Each subject was tracked from waitlist entry date until death or censoring to determine survival differences between the two groups. Of 2112 listed lung transplant candidates with bronchiectasis (180 non-CF, 1932 CF), 1617 were used for univariate Cox and Kaplan-Meier survival function analysis, 1173 for multivariate Cox models, and 182 for matched-pairs analysis based on propensity scores. Compared to CF, patients with non-CF bronchiectasis had a significantly lower mortality by univariate Cox analysis (HR 0.565; 95 % CI 0.424, 0.754; p < 0.001). Adjusting for potential confounders, multivariate Cox models identified a significant reduction in risk for death associated with non-CF bronchiectasis who were lung transplant candidates (HR 0.684; 95 % CI 0.475, 0.985; p = 0.041). Results were consistent in multivariate models adjusting for pulmonary hypertension and forced expiratory volume in one second. Non-CF bronchiectasis with advanced lung disease was associated with significantly lower mortality hazard compared to CF bronchiectasis on the waitlist for LTx. Separate referral and listing criteria for LTx in non-CF and CF populations should be considered.

Comparative biology of cystic fibrosis animal models.

PubMed

Fisher, John T; Zhang, Yulong; Engelhardt, John F

2011-01-01

Animal models of human diseases are critical for dissecting mechanisms of pathophysiology and developing therapies. In the context of cystic fibrosis (CF), mouse models have been the dominant species by which to study CF disease processes in vivo for the past two decades. Although much has been learned through these CF mouse models, limitations in the ability of this species to recapitulate spontaneous lung disease and several other organ abnormalities seen in CF humans have created a need for additional species on which to study CF. To this end, pig and ferret CF models have been generated by somatic cell nuclear transfer and are currently being characterized. These new larger animal models have phenotypes that appear to closely resemble human CF disease seen in newborns, and efforts to characterize their adult phenotypes are ongoing. This chapter will review current knowledge about comparative lung cell biology and cystic fibrosis transmembrane conductance regulator (CFTR) biology among mice, pigs, and ferrets that has implications for CF disease modeling in these species. We will focus on methods used to compare the biology and function of CFTR between these species and their relevance to phenotypes seen in the animal models. These cross-species comparisons and the development of both the pig and the ferret CF models may help elucidate pathophysiologic mechanisms of CF lung disease and lead to new therapeutic approaches.

The changing epidemiology and demography of cystic fibrosis.

PubMed

Stephenson, Anne L; Stanojevic, Sanja; Sykes, Jenna; Burgel, Pierre-Regis

2017-06-01

Once considered a pediatric disease with a poor prognosis, individuals born with cystic fibrosis (CF) today can expect to live well into adulthood. The implementation of multidisciplinary care, novel treatments and newborn screening has resulted in the rapid evolution in the demographics of the CF population. The purpose of this review is to highlight the evolving epidemiology and demographics of the CF population internationally. Copyright © 2017. Published by Elsevier Masson SAS.

Long-term outcomes of children with intermediate sweat chloride values in infancy.

PubMed

Groves, Tyler; Robinson, Paul; Wiley, Veronica; Fitzgerald, Dominic A

2015-06-01

To describe the clinical course of children who have intermediate sweat chloride values on initial screening for cystic fibrosis (CF). We performed a retrospective review of children with intermediate sweat chloride values (raised immunoreactive trypsinogen/1 copy of p.F508del CF mutation on newborn screening (NBS)/sweat chloride value of 30-59 mmol/L) presenting to The Children's Hospital at Westmead over 15 years. Patients with an intermediate sweat chloride evolving to a formal diagnosis of CF (termed "delayed CF") were matched (2:1) with NBS positive patients with CF (termed "NBS positive CF"). Clinical outcomes were compared. Fourteen of 29 (48%, 95% CI 0.3-0.66) patients with intermediate sweat chloride value evolved to a diagnosis of CF and were matched with 28 NBS positive patients with CF. Delayed CF had less pancreatic insufficiency (OR 0.06, 95% CI 0.01-0.44, P = .006), less colonization with nonmucoid Pseudomonas aeruginosa (OR 0.04, 95% CI 0.01-0.38, P = .005), milder obstructive lung disease (forced expiratory volume in 1 second/forced vital capacity ratio), and overall disease severity (Shwachman scores) at 10 years (mean difference 5.93, 95% CI 0.39-11.46, P = .04; mean difference 4.72, 95% CI 0.9-8.53, P = .015, respectively). Nutritional outcomes were better at 2 years for delayed CF but did not persist to later ages. In this cohort, approximately one-half of infants with intermediate sweat chloride value were later diagnosed with CF. The clinical course of delayed CF was milder in some aspects compared with NBS positive CF. These results emphasize the importance of ongoing follow-up of infants with intermediate sweat chloride values. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Chronic Rhinovirus Infection in an Adult with Cystic Fibrosis

PubMed Central

Bright-Thomas, Rowland J.; Tilston, Peter; Mutton, Kenneth J.; Guiver, Malcolm; Webb, A. Kevin; Jones, Andrew M.

2013-01-01

Rhinovirus is a common cause of exacerbations of cystic fibrosis (CF) and is usually considered a self-limiting infection. We report a case of chronic infection with rhinovirus A type 33 in a 43-year-old male with CF which has persisted for over 2 years. PMID:23966488

Bronchopulmonary infection-colonization patterns in Spanish cystic fibrosis patients: Results from a national multicenter study.

PubMed

de Dios Caballero, Juan; Del Campo, Rosa; Royuela, Ana; Solé, Amparo; Máiz, Luis; Olveira, Casilda; Quintana-Gallego, Esther; de Gracia, Javier; Cobo, Marta; de la Pedrosa, Elia Gómez G; Oliver, Antonio; Cantón, Rafael

2016-05-01

Clinical and demographical knowledge on Spanish cystic fibrosis (CF) patients is incomplete as no national registry exists. CF-microbiology has not been studied at national level. The results of the first Spanish multicenter study on CF microbiology are presented. 24 CF-Units for adult (n=12) and pediatric (n=12) patients from 17 hospitals provided sputa and clinical data from 15 consecutive patients. Cultures and susceptibility testing were performed. Colonization impact on pulmonary function was assessed. 341 patients [mean (SD) age 21 (11) years, 180≥18years, mean (SD) FEV1=68 (25)%] were included. Pseudomonas aeruginosa was reported as chronic, intermittent or absent in 46%, 22% and 32% of patients, respectively. The annual prevalence was 62%. Positive P. aeruginosa and methicillin-resistant Staphylococcus aureus cultures were significantly associated with lower FEV1 (p<0.001 and p=0.003, respectively). The representative subset of the Spanish CF-population which has been clinically, demographically and microbiologically characterized will serve as a reference for future CF studies in Spain. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

US Cystic Fibrosis Foundation and European Cystic Fibrosis Society consensus recommendations for the management of non-tuberculous mycobacteria in individuals with cystic fibrosis

PubMed Central

Olivier, Kenneth N; Saiman, Lisa; Daley, Charles L; Herrmann, Jean-Louis; Nick, Jerry A; Noone, Peadar G; Bilton, Diana; Corris, Paul; Gibson, Ronald L; Hempstead, Sarah E; Koetz, Karsten; Sabadosa, Kathryn A; Sermet-Gaudelus, Isabelle; Smyth, Alan R; van Ingen, Jakko; Wallace, Richard J; Winthrop, Kevin L; Marshall, Bruce C; Haworth, Charles S

2016-01-01

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause chronic pulmonary infection, particularly in individuals with pre-existing inflammatory lung disease such as cystic fibrosis (CF). Pulmonary disease caused by NTM has emerged as a major threat to the health of individuals with CF but remains difficult to diagnose and problematic to treat. In response to this challenge, the US Cystic Fibrosis Foundation (CFF) and the European Cystic Fibrosis Society (ECFS) convened an expert panel of specialists to develop consensus recommendations for the screening, investigation, diagnosis and management of NTM pulmonary disease in individuals with CF. Nineteen experts were invited to participate in the recommendation development process. Population, Intervention, Comparison, Outcome (PICO) methodology and systematic literature reviews were employed to inform draft recommendations. An anonymous voting process was used by the committee to reach consensus. All committee members were asked to rate each statement on a scale of: 0, completely disagree, to 9, completely agree; with 80% or more of scores between 7 and 9 being considered ‘good’ agreement. Additionally, the committee solicited feedback from the CF communities in the USA and Europe and considered the feedback in the development of the final recommendation statements. Three rounds of voting were conducted to achieve 80% consensus for each recommendation statement. Through this process, we have generated a series of pragmatic, evidence-based recommendations for the screening, investigation, diagnosis and treatment of NTM infection in individuals with CF as an initial step in optimising management for this challenging condition. PMID:26666259

ESR1 and PIK3CA mutational status in serum and plasma from metastatic breast cancer patients: A comparative study.

PubMed

Takeshita, Takashi; Yamamoto, Yutaka; Yamamoto-Ibusuki, Mutsuko; Tomiguchi, Mai; Sueta, Aiko; Iwase, Hirotaka

2018-04-07

Plasma and serum cell-free DNA (cfDNA) are useful sources of tumor DNA, but comparative investigations of the tumor mutational status between them are rare. we performed droplet digital PCR assay for representative hotspot mutations in metastatic breast cancer (MBC) (ESR1 and PIK3CA) in serum and plasma cfDNA concurrently extracted from the blood of 33 estrogen receptor-positive MBC patients. ESR1 mutations in plasma cfDNA were found in 7 of the 33 patients; ESR1 mutations in serum cfDNA were detected in only one out of 7 patients with ESR1 mutations in plasma cfDNA. PIK3CA exon 9 and exon 20 mutations in plasma cfDNA were found in 3 and 7 out of the 33 patients, respectively; PIK3CA exon 9 mutations in serum cfDNA were detected in 2 out of 3 patients with PIK3CA exon 9 mutations in plasma cfDNA; PIK3CA exon 20 mutations in serum cfDNA were detected in 2 out of 7 patients with PIK3CA exon 20 mutations in plasma cfDNA. Here we show the higher frequency of ESR1 and PIK3CA mutations in the plasma than in the serum in 33 MBC patients; therefore, serum samples should not be considered the preferred source of cfDNA.

Outcomes of infants with indeterminate diagnosis detected by cystic fibrosis newborn screening.

PubMed

Ren, Clement L; Fink, Aliza K; Petren, Kristofer; Borowitz, Drucy S; McColley, Susanna A; Sanders, Don B; Rosenfeld, Margaret; Marshall, Bruce C

2015-06-01

Cystic fibrosis transmembrane conductance regulator-related metabolic syndrome (CRMS) describes asymptomatic infants with a positive cystic fibrosis (CF) newborn screen (NBS) but inconclusive diagnostic testing for CF. Little is known about the epidemiology and outcomes of CRMS. The goal of this study was to determine the prevalence, clinical features, and short-term outcomes of infants with CRMS. We analyzed data from the US CF Foundation Patient Registry (CFFPR) from 2010 to 2012. We compared demographic, diagnostic, anthropometric, health care utilization, microbiology, and treatment characteristics between infants with CF and infants with CRMS. There were 1983 infants diagnosed via NBS between 2010 and 2012 reported to the CFFPR. By using the CF Foundation guideline definitions, 1540 and 309 infants met the criteria for CF and CRMS, respectively (CF:CRMS ratio = 5.0:1.0). Of note, 40.8% of infants with CRMS were entered into the registry with a clinical diagnosis of CF. Infants with CRMS tended to have normal nutritional indices. However, 11% of infants with CRMS had a positive Pseudomonas aeruginosa respiratory tract culture in the first year of life. CRMS is a common outcome of CF NBS, and some infants with CRMS may develop features concerning for CF disease. A substantial proportion of infants with CRMS were assigned a clinical diagnosis of CF, which may reflect misclassification or clinical features not collected in the CFFPR. Copyright © 2015 by the American Academy of Pediatrics.

Acidic pH increases airway surface liquid viscosity in cystic fibrosis

PubMed Central

Tang, Xiao Xiao; Ostedgaard, Lynda S.; Hoegger, Mark J.; Moninger, Thomas O.; Karp, Philip H.; McMenimen, James D.; Choudhury, Biswa; Varki, Ajit; Stoltz, David A.; Welsh, Michael J.

2016-01-01

Cystic fibrosis (CF) disrupts respiratory host defenses, allowing bacterial infection, inflammation, and mucus accumulation to progressively destroy the lungs. Our previous studies revealed that mucus with abnormal behavior impaired mucociliary transport in newborn CF piglets prior to the onset of secondary manifestations. To further investigate mucus abnormalities, here we studied airway surface liquid (ASL) collected from newborn piglets and ASL on cultured airway epithelia. Fluorescence recovery after photobleaching revealed that the viscosity of CF ASL was increased relative to that of non-CF ASL. CF ASL had a reduced pH, which was necessary and sufficient for genotype-dependent viscosity differences. The increased viscosity of CF ASL was not explained by pH-independent changes in HCO3– concentration, altered glycosylation, additional pH-induced disulfide bond formation, increased percentage of nonvolatile material, or increased sulfation. Treating acidic ASL with hypertonic saline or heparin largely reversed the increased viscosity, suggesting that acidic pH influences mucin electrostatic interactions. These findings link loss of cystic fibrosis transmembrane conductance regulator–dependent alkalinization to abnormal CF ASL. In addition, we found that increasing Ca2+ concentrations elevated ASL viscosity, in part, independently of pH. The results suggest that increasing pH, reducing Ca2+ concentration, and/or altering electrostatic interactions in ASL might benefit early CF. PMID:26808501

Impact of Scedosporium apiospermum complex seroprevalence in patients with cystic fibrosis.

PubMed

Parize, Perrine; Billaud, Sandrine; Bienvenu, Anne L; Bourdy, Stéphanie; le Pogam, Marie A; Reix, Philippe; Picot, Stéphane; Robert, Raymond; Lortholary, Olivier; Bouchara, Jean-Philippe; Durieu, Isabelle

2014-12-01

Species of the Scedosporium apiospermum complex (S. a complex) are emerging fungi responsible for chronic airway colonization in cystic fibrosis (CF) patients. Recent studies performed on Aspergillus fumigatus suggest that the colonization of the airways by filamentous fungi may contribute to the progressive deterioration of lung function. We studied S. a complex seroprevalence, as a marker of close contact between patient and the fungi, in a large monocentric cohort of CF patients attended in a reference centre in Lyon, France. Serum samples from 373 CF patients were analysed. Antibodies against S. a complex were detected in 35 patients (9.4%). In multivariate analysis, S. a complex seropositivity was only associated with seropositivity to A. fumigatus. This study does not suggest an association between sensitization against S. a complex and poorer lung function in CF. Prospective studies are needed to evaluate the impact of both seropositivity and S. a complex colonization on the course of CF. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Developing new products in cystic fibrosis: needs and obstacles for activities of small and middle-sized companies.

PubMed

Schlangen, Miriam; Reimann, Andreas L G

2011-06-01

Small and middle-sized enterprises (SMEs) can make important contributions to medical progress through the development of new safe and effective drugs that address the greatest unmet needs of patients. Regulatory inconsistencies across agencies in various countries, however, remain major challenges in cystic fibrosis (CF) drug development. Clear and consistent treatment guidelines, well educated clinical trial sites, a patient registry and grant funding for early development programs are important success-factors for an efficient development process. SMEs developing products for CF need partners in the CF community to assist with disease education and awareness for ongoing clinical trials. SMEs should collaborate and communicate with the CF community in a legally compliant way to take a patient-centric approach to drug design, development and administration. Furthermore, they can help to develop educational tools and fund medical education activities to increase the understanding of the underlying defects and mechanisms of CF disease. Copyright © 2011 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Restoration of Chloride Efflux by Azithromycin in Airway Epithelial Cells of Cystic Fibrosis Patients▿

PubMed Central

Saint-Criq, Vinciane; Rebeyrol, Carine; Ruffin, Manon; Roque, Telma; Guillot, Loïc; Jacquot, Jacky; Clement, Annick; Tabary, Olivier

2011-01-01

Azithromycin (AZM) has shown promising anti-inflammatory properties in chronic obstructive pulmonary diseases, and clinical studies have presented an improvement in the respiratory condition of cystic fibrosis (CF) patients. The aim of this study was to investigate, in human airway cells, the mechanism by which AZM has beneficial effects in CF. We demonstrated that AZM did not have any anti-inflammatory effect on CF airway cells but restored Cl− efflux. PMID:21220528

Host-pathogen interplay in the respiratory environment of Cystic Fibrosis

PubMed Central

Hurley, Bryan P.; Bragonzi, Alessandra

2015-01-01

Significant advances have been made in the understanding of disease progression in cystic fibrosis (CF), revealing a complex interplay between host and pathogenic organisms. The diverse CF microbiota within the airway activates an aberrant immune response that is ineffective in clearing infection. An appreciation of how the CF host immune system interacts with these organisms is crucial to understanding the pathogenesis of CF pulmonary disease. Here we discuss the microbial complexity present in the lungs of individuals with CF, review emerging concepts of innate and adaptive immune responses to pathogens that chronically inhabit the CF lung, and discuss therapies that target the aberrant inflammatory response that characterizes CF. A greater understanding of the underlying mechanisms will shed light on pathogenesis and guide more targeted therapies in the future that serve to reduce infection, minimize lung pathology, and improve the quality of life for patients with CF. PMID:25800687

Siblings of children with cystic fibrosis: quality of life and the impact of illness.

PubMed

Havermans, T; Wuytack, L; Deboel, J; Tijtgat, A; Malfroot, A; De Boeck, C; Proesmans, M

2011-03-01

To asses self-reported quality of life (QoL) and perception of impact of illness on siblings of children with cystic fibrosis (CF). The Child Health Questionnaire was used to assess QoL. The Sibling Perception Questionnaire was used to assess impact of illness. Siblings of children with CF (n= 39) rated their QoL higher than siblings of healthy children on most QoL domains (e.g. Physical Functioning, Behavior, Mental Health). Siblings older than the child with CF reported a higher impact of CF than younger siblings. Perceived impact of illness was higher when the child with CF had been hospitalized or was intermittent or chronically infected with Pseudomonas aeruginosa. Siblings of children with CF reported a good QoL. QoL and impact of illness were related to indices of CF severity. Insight into sibling-issues helps CF teams to provide family-oriented care. © 2010 Blackwell Publishing Ltd.

Finding Motivation: Online Information Seeking Following Newborn Screening for Cystic Fibrosis.

PubMed

Strekalova, Yulia A

2016-07-01

Cystic fibrosis (CF) is a genetic disease that has no manifestations for carriers but is terminal for those diagnosed with it. CF is identified through newborn screening (NBS) tests, and most families have no knowledge about CF before their contact with a NBS program. Acknowledging the Internet as a popular health information source, this study examined information exchange about CF in online community forums. This article, guided by self-determination theory, aimed at providing understanding of psychological needs and motivation for health information seeking and active communication about CF. Through online communication with other families who share similar experience, caregivers of newborns diagnosed with CF sought and received support for their competence, autonomy, and relatedness needs during the initial CF testing and diagnosis reconciliation process. Online communities play an important role in the information seeking related to CF diagnosis and could become active partners in strategic knowledge dissemination efforts. © The Author(s) 2015.

Cystic fibrosis lung transplantation.

PubMed

Braun, Andrew T; Merlo, Christian A

2011-11-01

This review summarizes recently published investigations on issues pertaining to cystic fibrosis (CF) lung transplantation. We specifically focus on indications and candidate selection as well as infectious and noninfectious issues specific to CF lung transplant recipients. Recent studies have focused on candidate adequacy in high-risk CF patients. We review the current literature on individuals who develop respiratory failure requiring mechanical ventilation and those patients with a pretransplant diagnosis of pulmonary hypertension. Furthermore, the management of peri-operative infectious issues is reviewed including recurrent infections with multidrug-resistant bacterial, mycobacterial, and fungal organisms. Other CF-specific issues addressed include common comorbidities such as CF-related diabetes, gastroesophageal reflux, CF liver disease, and bone metabolism. Lung transplantation is a limited, but potentially life-saving therapeutic option for patients with CF. Optimal candidate selection and awareness of CF-specific issues in the pretransplant and posttransplant setting may lead to better long-term outcomes. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins

Improving the Sensitivity and Positive Predictive Value in a Cystic Fibrosis Newborn Screening Program Using a Repeat Immunoreactive Trypsinogen and Genetic Analysis.

PubMed

Sontag, Marci K; Lee, Rachel; Wright, Daniel; Freedenberg, Debra; Sagel, Scott D

2016-08-01

To evaluate the performance of a new cystic fibrosis (CF) newborn screening algorithm, comprised of immunoreactive trypsinogen (IRT) in first (24-48 hours of life) and second (7-14 days of life) dried blood spot plus DNA on second dried blood spot, over existing algorithms. A retrospective review of the IRT/IRT/DNA algorithm implemented in Colorado, Wyoming, and Texas. A total of 1 520 079 newborns were screened, 32 557 (2.1%) had abnormal first IRT; 8794 (0.54%) on second. Furthermore, 14 653 mutation analyses were performed; 1391 newborns were referred for diagnostic testing; 274 newborns were diagnosed; and 201/274 (73%) of newborns had 2 mutations on the newborn screening CFTR panel. Sensitivity was 96.2%, compared with sensitivity of 76.1% observed with IRT/IRT (105 ng/mL cut-offs, P < .0001). The ratio of newborns with CF to heterozygote carriers was 1:2.5, and newborns with CF to newborns with CFTR-related metabolic syndrome was 10.8:1. The overall positive predictive value was 20%. The median age of diagnosis was 28, 30, and 39.5 days in the 3 states. IRT/IRT/DNA is more sensitive than IRT/IRT because of lower cut-offs (∼97 percentile or 60 ng/mL); higher cut-offs in IRT/IRT programs (>99 percentile, 105 ng/mL) would not achieve sufficient sensitivity. Carrier identification and identification of newborns with CFTR-related metabolic syndrome is less common in IRT/IRT/DNA compared with IRT/DNA. The time to diagnosis is nominally longer, but diagnosis can be achieved in the neonatal period and opportunities to further improve timeliness have been enacted. IRT/IRT/DNA algorithm should be considered by programs with 2 routine screens. Copyright © 2016 Elsevier Inc. All rights reserved.

Cystic Fibrosis: Microbiology and Host Response.

PubMed

Zemanick, Edith T; Hoffman, Lucas R

2016-08-01

The earliest descriptions of lung disease in people with cystic fibrosis (CF) showed the involvement of 3 interacting pathophysiologic elements in CF airways: mucus obstruction, inflammation, and infection. Over the past 7 decades, our understanding of CF respiratory microbiology and inflammation has evolved with the introduction of new treatments, increased longevity, and increasingly sophisticated laboratory techniques. This article reviews the current understanding of infection and inflammation and their roles in CF lung disease. It also discusses how this constantly evolving information is used to inform current therapeutic strategies, measures and predictors of disease severity, and research priorities. Copyright © 2016 Elsevier Inc. All rights reserved.

Anabolic agent use in adults with cystic fibrosis.

PubMed

Green, Heather D; Barry, Peter J; Jones, Andrew M

2015-10-01

The use of non-prescribed anabolic agents amongst non-athletes is increasing with young, adult males with cystic fibrosis (CF) in the highest risk demographic. There is evidence that anabolic agents increase weight and muscle mass in adults with a variety of catabolic conditions but there is no evidence for their use in hormone sufficient adults with CF. We report a case of anabolic agent use in a male adult with CF and review the clinical features of anabolic agent use with a focus on adults with CF. Copyright © 2015 Elsevier Ltd. All rights reserved.

Human airway epithelial cells investigated by atomic force microscopy: A hint to cystic fibrosis epithelial pathology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lasalvia, Maria; Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Bari; Castellani, Stefano

The pathophysiology of cystic fibrosis (CF) airway disease stems from mutations in the CF Transmembrane Conductance Regulator (CFTR) gene, leading to a chronic respiratory disease. Actin cytoskeleton is disorganized in CF airway epithelial cells, likely contributing to the CF-associated basic defects, i.e. defective chloride secretion and sodium/fluid hypersorption. In this work, we aimed to find whether this alteration could be pointed out by means of Atomic Force Microscopy (AFM) investigation, as roughness and Young's elastic module. Moreover, we also sought to determine whether disorganization of actin cytoskeleton is linked to hypersoption of apical fluid. Not only CFBE41o- (CFBE) cells, immortalizedmore » airway epithelial cells homozygous for the F508del CFTR allele, showed a different morphology in comparison with 16HBE14o- (16HBE) epithelial cells, wild-type for CFTR, but also they displayed a lack of stress fibers, suggestive of a disorganized actin cytoskeleton. AFM measurements showed that CFBE cells presented a higher membrane roughness and decreased rigidity as compared with 16HBE cells. CFBE overexpressing wtCFTR became more elongated than the parental CFBE cell line and presented actin stress fibers. CFBE cells absorbed more fluid from the apical compartment. Study of fluid absorption with the F-actin-depolymerizing agent Latrunculin B demonstrated that actin cytoskeletal disorganization increased fluid absorption, an effect observed at higher magnitude in 16HBE than in CFBE cells. For the first time, we demonstrate that actin cytoskeleton disorganization is reflected by AFM parameters in CF airway epithelial cells. Our data also strongly suggest that the lack of stress fibers is involved in at least one of the early step in CF pathophysiology at the levels of the airways, i.e. fluid hypersorption. - Highlights: • CF bronchial epithelial (CFBE) cells show a disorganized actin cytoskeleton. • CFBE cells present high roughness and low rigidity in the plasmamembrane. • CFTR overexpression changes morphology and actin organization. • CFBE cells absorb more apical fluid than wild type bronchial epithelial cells. • Fluid absorption is increased by disorganization of actin cytoskeleton.« less

Differences in clinical condition and genotype at time of diagnosis of cystic fibrosis by newborn screening or by symptoms.

PubMed

Vernooij-van Langen, A M M; Gerzon, F L G R; Loeber, J G; Dompeling, E; Dankert-Roelse, J E

2014-01-01

Early diagnosis through newborn screening (NBS) and early treatment of cystic fibrosis (CF) do lead to better prognosis. In the Netherlands, the median age for a clinical diagnosis is six months, and after newborn screening this is 30 days. It is unknown if being diagnosed at the age of six months or before two months leads to a clinically relevant difference of the clinical condition at the time of diagnosis. The aim of this study is to assess the differences in clinical parameters at diagnosis between children with CF identified by newborn screening (NBS) or by clinical diagnosis (CD) in the Netherlands. From July 1st, 2007 to January 1st, 2012 all newly diagnosed CF patients were reported to the Dutch Paediatric Surveillance Unit (DPSU). All paediatricians received a questionnaire to collect data on mutations and clinical condition at diagnosis. Non-classical CF was excluded from the analysis on clinical condition. 204 new CF diagnoses were reported to the DPSU, 33 were reported twice and three had no CF after further testing. 127 questionnaires were returned (76%); 85 children were diagnosed because of clinical symptoms, 40 after NBS and two because of a positive family history. The median age at diagnosis was 34 weeks for a clinical diagnosis and 3 weeks after NBS. Non-classical CF was more prevalent in the NBS group (6 clinical, 14 NBS), mostly F508del/R117H7T (12). Compared to the NBS group, significantly more patients in the CD group showed failure to thrive, respiratory symptoms, and hospitalizations. 62% of the CD group showed abnormal signs at physical examination compared to 4% of the NBS group. At the time of diagnosis infants detected after NBS are in a significantly better condition than after a clinical diagnosis. Growth retardation is already seen when after NBS the diagnosis is confirmed, but NBS leads to a diagnosis before respiratory symptoms have developed. Copyright © 2014 Elsevier Inc. All rights reserved.

Label-free DNA biosensor based on a peptide nucleic acid-functionalized microstructured optical fiber-Bragg grating

NASA Astrophysics Data System (ADS)

Candiani, Alessandro; Bertucci, Alessandro; Giannetti, Sara; Konstantaki, Maria; Manicardi, Alex; Pissadakis, Stavros; Cucinotta, Annamaria; Corradini, Roberto; Selleri, Stefano

2013-05-01

We describe a novel sensing approach based on a functionalized microstructured optical fiber-Bragg grating for specific DNA target sequences detection. The inner surface of a microstructured fiber, where a Bragg grating was previously inscribed, has been functionalized by covalent linking of a peptide nucleic acid probe targeting a DNA sequence bearing a single point mutation implicated in cystic fibrosis (CF) disease. A solution of an oligonucleotide (ON) corresponding to a tract of the CF gene containing the mutated DNA has been infiltrated inside the fiber capillaries and allowed to hybridize to the fiber surface according to the Watson-Crick pairing. In order to achieve signal amplification, ON-functionalized gold nanoparticles were then infiltrated and used in a sandwich-like assay. Experimental measurements show a clear shift of the reflected high order mode of a Bragg grating for a 100 nM DNA solution, and fluorescence measurements have confirmed the successful hybridization. Several experiments have been carried out on the same fiber using the identical concentration, showing the same modulation trend, suggesting the possibility of the reuse of the sensor. Measurements have also been made using a 100 nM mismatched DNA solution, containing a single nucleotide mutation and corresponding to the wild-type gene, and the results demonstrate the high selectivity of the sensor.

Sleep Phase Delay in Cystic Fibrosis: A Potential New Manifestation of Cystic Fibrosis Transmembrane Regulator Dysfunction.

PubMed

Jensen, Judy L; Jones, Christopher R; Kartsonaki, Christiana; Packer, Kristyn A; Adler, Frederick R; Liou, Theodore G

2017-08-01

Cystic fibrosis (CF) transmembrane regulator (CFTR) protein dysfunction causes CF. Improving survival allows detection of increasingly subtle disease manifestations. CFTR dysfunction in the central nervous system (CNS) may disturb circadian rhythm and thus sleep phase. We studied sleep in adults to better understand potential CNS CFTR dysfunction. We recruited participants from April 2012 through April 2015 and administered the Munich Chronotype Questionnaire (MCTQ). We compared free-day sleep measurements between CF and non-CF participants and investigated associations with CF survival predictors. We recruited 23 female and 22 male adults with CF aged 18 to 46 years and 26 female and 22 male volunteers aged 18 to 45 years. Compared with volunteers without CF, patients with CF had delayed sleep onset (0.612 h; P = .015), midsleep (1.11 h; P < .001), and wake (1.15 h; P < .001) times and prolonged sleep latency (7.21 min; P = .05) and duration (0.489 h; P = .05). Every hour delay in sleep onset was associated with shorter sleep duration by 0.29 h in patients with CF and 0.75 h in subjects without CF (P = .007) and longer sleep latency by 7.51 min in patients with CF and 1.6 min in volunteers without CF (P = .035). Among patients with CF, FEV 1 % predicted, prior acute pulmonary exacerbations, and weight were independent of all free-day sleep measurements. CF in adults is associated with marked delays in sleep phase consistent with circadian rhythm phase delays. Independence from disease characteristics predictive of survival suggests that sleep phase delay is a primary manifestation of CFTR dysfunction in the CNS. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Population Dynamics of Staphylococcus aureus in Cystic Fibrosis Patients To Determine Transmission Events by Use of Whole-Genome Sequencing

PubMed Central

Hall, Barry G.

2017-01-01

ABSTRACT Strict infection control practices have been implemented for health care visits by cystic fibrosis (CF) patients in an attempt to prevent transmission of important pathogens. This study used whole-genome sequencing (WGS) to determine strain relatedness and assess population dynamics of Staphylococcus aureus isolates from a cohort of CF patients as assessed by strain relatedness. A total of 311 S. aureus isolates were collected from respiratory cultures of 115 CF patients during a 22-month study period. Whole-genome sequencing was performed, and using single nucleotide polymorphism (SNP) analysis, phylogenetic trees were assembled to determine relatedness between isolates. Methicillin-resistant Staphylococcus aureus (MRSA) phenotypes were predicted using PPFS2 and compared to the observed phenotype. The accumulation of SNPs in multiple isolates obtained over time from the same patient was examined to determine if a genomic molecular clock could be calculated. Pairs of isolates with ≤71 SNP differences were considered to be the “same” strain. All of the “same” strain isolates were either from the same patient or siblings pairs. There were 47 examples of patients being superinfected with an unrelated strain. The predicted MRSA phenotype was accurate in all but three isolates. Mutation rates were unable to be determined because the branching order in the phylogenetic tree was inconsistent with the order of isolation. The observation that transmissions were identified between sibling patients shows that WGS is an effective tool for determining transmission between patients. The observation that transmission only occurred between siblings suggests that Staphylococcus aureus acquisition in our CF population occurred outside the hospital environment and indicates that current infection prevention efforts appear effective. PMID:28446577

Nutritional assessment in children with cystic fibrosis

USDA-ARS?s Scientific Manuscript database

Optimal nutrition, including consuming 35–40% of calories (kcal) as fat, is a vital part of the management of cystic fibrosis (CF), and involves accurate assessment of dietary intake. We compared 3 methods of nutritional assessment in 8– to 14-year-old children (n=20) with CF: 1) a 24-h Dietary Reca...

Associations between Academic Achievement and Psychosocial Variables in Adolescents with Cystic Fibrosis

ERIC Educational Resources Information Center

Grieve, Adam J.; Tluczek, Audrey; Racine-Gilles, Caroline N.; Laxova, Anita; Albers, Craig A.; Farrell, Philip M.

2011-01-01

Background: Cystic fibrosis (CF) is a chronic genetic disease that leads to the accumulation of thick mucus in multiple organ systems, leading to chronic lung infection and affecting the body's ability to absorb nutrients necessary for growth and development. This cross-sectional, correlational study examined the potential effects of CF on…

Exploring Cystic Fibrosis Using Bioinformatics Tools: A Module Designed for the Freshman Biology Course

ERIC Educational Resources Information Center

Zhang, Xiaorong

2011-01-01

We incorporated a bioinformatics component into the freshman biology course that allows students to explore cystic fibrosis (CF), a common genetic disorder, using bioinformatics tools and skills. Students learn about CF through searching genetic databases, analyzing genetic sequences, and observing the three-dimensional structures of proteins…

Differences between WHO AND CDC early growth measurements in the assessment of Cystic Fibrosis clinical outcomes.

PubMed

Usatin, Danielle; Yen, Elizabeth H; McDonald, Catherine; Asfour, Fadi; Pohl, John; Robson, Jacob

2017-07-01

Early childhood growth status has been used to predict long-term clinical outcomes in Cystic Fibrosis (CF) patients. Adulthood CF outcomes based on early weight-for-length (WFL) measurements, using either World Health Organization (WHO) or Centers for Disease Control (CDC) scales, have not been compared. Cystic Fibrosis Foundation registry patients were studied (n=3014). Participants were categorized at age two years as WFL <50th percentile on both WHO and CDC scales, ≥50th percentile on WHO but not CDC, or ≥50th percentile on both. Pulmonary function and overall survival were assessed at age 18years. Stepwise gains in pulmonary function and lung transplant-free survival were noted across the three increasing WFL categories. Children with CF who achieve higher WFL at age two years have improved pulmonary and survival outcomes into adulthood. CF providers should continue to utilize current early growth recommendations, with goal WFL ≥50th percentile on CDC growth charts before age two. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Control of the proinflammatory state in cystic fibrosis lung epithelial cells by genes from the TNF-alphaR/NFkappaB pathway.

PubMed Central

Eidelman, O.; Srivastava, M.; Zhang, J.; Leighton, X.; Murtie, J.; Jozwik, C.; Jacobson, K.; Weinstein, D. L.; Metcalf, E. L.; Pollard, H. B.

2001-01-01

BACKGROUND: Cystic fibrosis (CF) is the most common, lethal autosomal recessive disease affecting children in the United States and Europe. Extensive work is being performed to develop both gene and drug therapies. The principal mutation causing CF is in the CFTR gene ([Delta F508]CFTR). This mutation causes the mutant protein to traffic poorly to the plasma membrane, and degrades CFTR chloride channel activity. CPX, a candidate drug for CF, binds to mutant CFTR and corrects the trafficking deficit. CPX also activates mutant CFTR chloride channel activity. CF airways are phenotypically inundated by inflammatory signals, primarily contributed by sustained secretion of the proinflammatory cytokine interleukin 8 (IL-8) from mutant CFTR airway epithelial cells. IL-8 production is controlled by genes from the TNF-alphaR/NFkappaB pathway, and it is possible that the CF phenotype is due to dysfunction of genes from this pathway. In addition, because drug therapy with CPX and gene therapy with CFTR have the same common endpoint of raising the levels of CFTR, we have hypothesized that either approach should have a common genomic endpoint. MATERIALS AND METHODS: To test this hypothesis, we studied IL-8 secretion and global gene expression in IB-3 CF lung epithelial cells. The cells were treated by either gene therapy with wild-type CFTR, or by pharmacotherapy with the CFTR-surrogate drug CPX. CF cells, treated with either CFTR or CPX, were also exposed to Pseudomonas aeruginosa, a common chronic pathogen in CF patients. cDNA microarrays were used to assess global gene expression under the different conditions. A novel bioinformatic algorithm (GENESAVER) was developed to identify genes whose expression paralleled secretion of IL-8. RESULTS: We report here that IB3 CF cells secrete massive levels of IL-8. However, both gene therapy with CFTR and drug therapy with CPX substantially suppress IL-8 secretion. Nonetheless, both gene and drug therapy allow the CF cells to respond with physiologic secretion of IL-8 when the cells are exposed to P. aeruginosa. Thus, neither CFTR nor CPX acts as a nonspecific suppressor of IL-8 secretion from CF cells. Consistently, pharmacogenomic analysis indicates that CF cells treated with CPX greatly resemble CF cells treated with CFTR by gene therapy. Additionally, the same result obtains in the presence of P. aeruginosa. Classical hierarchical cluster analysis, based on similarity of global gene expression, also supports this conclusion. The GENESAVER algorithm, using the IL-8 secretion level as a physiologic variable, identifies a subset of genes from the TNF-alphaR/NFkappaB pathway that is expressed in phase with IL-8 secretion from CF epithelial cells. Certain other genes, previously known to be positively associated with CF, also fall into this category. Identified genes known to code for known inhibitors are expressed inversely, out of phase with IL-8 secretion. CONCLUSIONS: Wild-type CFTR and CPX both suppress proinflammatory IL-8 secretion from CF epithelial cells. The mechanism, as defined by pharmacogenomic analysis, involves identified genes from the TNF-alphaR/NFkappaB pathway. The close relationship between IL-8 secretion and genes from the TNF-alphaR/NFkappaB pathway suggests that molecular or pharmaceutical targeting of these novel genes may have strategic use in the development of new therapies for CF. From the perspective of global gene expression, both gene and drug therapy have similar genomic consequences. This is the first example showing equivalence of gene and drug therapy in CF, and suggests that a gene therapy-defined endpoint may prove to be a powerful paradigm for CF drug discovery. Finally, because the GENESAVER algorithm is capable of isolating disease-relevant genes in a hypothesis-driven manner without recourse to any a priori knowledge about the system, this new algorithm may also prove useful in applications to other genetic diseases. PMID:11591888

Gene delivery to the lungs: pulmonary gene therapy for cystic fibrosis.

PubMed

Villate-Beitia, Ilia; Zarate, Jon; Puras, Gustavo; Pedraz, José Luis

2017-07-01

Cystic fibrosis (CF) is a monogenic autosomal recessive disorder where the defective gene, the cystic fibrosis transmembrane conductance regulator (CFTR), is well identified. Moreover, the respiratory tract can be targeted through noninvasive aerosolized formulations for inhalation. Therefore, gene therapy is considered a plausible strategy to address this disease. Conventional gene therapy strategies rely on the addition of a correct copy of the CFTR gene into affected cells in order to restore the channel activity. In recent years, genome correction strategies have emerged, such as zinc-finger nucleases, transcription activator-like effector nucleases and clustered regularly interspaced short palindromic repeats associated to Cas9 nucleases. These gene editing tools aim to repair the mutated gene at its original genomic locus with high specificity. Besides, the success of gene therapy critically depends on the nucleic acids carriers. To date, several clinical studies have been carried out to add corrected copies of the CFTR gene into target cells using viral and non-viral vectors, some of them with encouraging results. Regarding genome editing systems, preliminary in vitro studies have been performed in order to repair the CFTR gene. In this review, after briefly introducing the basis of CF, we discuss the up-to-date gene therapy strategies to address the disease. The review focuses on the main factors to take into consideration when developing gene delivery strategies, such as the design of vectors and plasmid DNA, in vitro/in vivo tests, translation to human use, administration methods, manufacturing conditions and regulatory issues.

Newborn screening: an appeal for improved parent education.

PubMed

Tluczek, Audrey; Orland, Kate Murphy; Nick, Sara Wolfgram; Brown, Roger L

2009-01-01

The purpose of this study, which was part of a larger investigation of newborn screening (NBS) for cystic fibrosis (CF), was to learn how parents were informed about NBS and obtain their suggestions for improving the process of educating parents about NBS. Qualitative study using directed and summative content analyses was conducted on 100 interviews with 193 parents of 100 newborns recruited from 4 clinical populations including parents of infants with (1) a CF diagnosis, (2) one CF mutation and therefore CF carriers, (3) congenital hypothyroidism, and (4) normal screening results. Parents described much inconsistency in the timing of and methods used to inform them about NBS. Mothers with higher income were 3.69 times more likely to receive information before their infants' births than mothers with lower income. Parents recommended improving verbal and written communication with parents about NBS at multiple junctures from preconception to the infant's first few days of life. Parents suggested that providers take time to explain the purpose and importance of NBS, which diseases are included in testing, and when parents can expect results. These findings suggest a need to establish evidence-based guidelines for informing parents about NBS.

Genetics and epithelial cell dysfunction in cystic fibrosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riordan, J.R.; Buchwald, M.

1987-01-01

This book examines the advances being made in the study of the physiology, cell biology, and molecular genetics of cystic fibrosis. Emphasis is placed on various areas of research that involve epithelial cells (e.g., the CF-specific phenotypes exhibited by epithelial cells, abnormalities in epithelium ion transport, chloride channel regulation in CF epithelial.) Coverage is presented on the current status of CF, including data on the incidence of the disease, its mode of inheritance, chromosomal localization, genetic heterogeneity, and screening and management.

Diagnosis of cystic fibrosis in a patient of Egyptian background.

PubMed

Yoshida, Rie; Ruge, Bobby

2016-10-20

Cystic fibrosis (CF) is the most common genetically inherited condition in European-derived populations. However, it is being increasingly recognised in other populations, including people of Asian, Black African and Caribbean descent. We present a case detailing the diagnosis of CF in a 12-year-old patient of Egyptian background who had been treated for difficult asthma. In doing so, we aim to highlight the importance of considering CF in all patients, regardless of ethnicity. 2016 BMJ Publishing Group Ltd.

Best practices in the treatment of early cystic fibrosis lung disease.

PubMed

Proesmans, Marijke

2017-02-01

For many years, management of cystic fibrosis (CF) lung disease was focused on symptomatic treatment of chronic lung infection, which is characterized by cough and sputum production, leading to progressive lung damage. With increasing survival and better knowledge of the pathogenesis of CF lung disease, it has become clear that treatment has to start very early because lung damage occurs in young patients, often before obvious symptoms appear. The arrival of new cystic fibrosis transmembrane conductance-regulator (CFTR)-correcting therapies will bring more opportunities to prevent the disease, apart from only treating chronic lung infection. In this review, a summary of the current knowledge of early CF lung disease is provided, based on animal model studies, as well as on data obtained from well structured follow-up programs after newborn screening (NBS). The most important clinical guidelines for treating young CF patients are also summarized.

Information needs of parents of infants diagnosed with cystic fibrosis: Results of a pilot study.

PubMed

Edwards, Danielle J; Wicking, Kristin; Smyth, Wendy; Shields, Linda; Douglas, Tonia

2018-01-01

This study investigated the information needs, priorities and information-seeking behaviours of parents of infants recently diagnosed with cystic fibrosis (CF) following newborn screening, by piloting the 'Care of Cystic Fibrosis Families Survey'. The questionnaires were posted to eligible parents ( n = 66) attending CF clinics in hospitals in two Australian states; reply-paid envelopes were provided for return of the questionnaires. Twenty-six were returned (response rate 39.4%). The most common questions to which parents required answers during their initial education period related to what CF is, how it is treated and how to care for their child. Parents preferred face-to-face consultations to deliver information, and yet all reported using the Internet to search for more information at some point during the education period. Many parents provided negative feedback about being given their child's CF diagnosis via telephone. The timing, content and method of information delivery can all affect the initial education experience. We can deliver education to better suit the information needs and priorities for education of parents of infants recently diagnosed with CF. The Care of Cystic Fibrosis Families Survey was successfully piloted and recommendations for amendments have been made for use in a larger study across Australia.

The Pseudomonas aeruginosa Magnesium Transporter MgtE Inhibits Transcription of the Type III Secretion System▿ †

PubMed Central

Anderson, Gregory G.; Yahr, Timothy L.; Lovewell, Rustin R.; O'Toole, George A.

2010-01-01

Pseudomonas aeruginosa is an opportunistic pathogen that causes life-long pneumonia in individuals with cystic fibrosis (CF). These long-term infections are maintained by bacterial biofilm formation in the CF lung. We have recently developed a model of P. aeruginosa biofilm formation on cultured CF airway epithelial cells. Using this model, we discovered that mutation of a putative magnesium transporter gene, called mgtE, led to increased cytotoxicity of P. aeruginosa toward epithelial cells. This altered toxicity appeared to be dependent upon expression of the type III secretion system (T3SS). In this study, we found that mutation of mgtE results in increased T3SS gene transcription. Through epistasis analyses, we discovered that MgtE influences the ExsE-ExsC-ExsD-ExsA gene regulatory system of T3SS by either directly or indirectly inhibiting ExsA activity. While variations in calcium levels modulate T3SS gene expression in P. aeruginosa, we found that addition of exogenous magnesium did not inhibit T3SS activity. Furthermore, mgtE variants that were defective for magnesium transport could still complement the cytotoxicity effect. Thus, the magnesium transport function of MgtE does not fully explain the regulatory effects of MgtE on cytotoxicity. Overall, our results indicate that MgtE modulates expression of T3SS genes. PMID:20028803

The Pseudomonas aeruginosa magnesium transporter MgtE inhibits transcription of the type III secretion system.

PubMed

Anderson, Gregory G; Yahr, Timothy L; Lovewell, Rustin R; O'Toole, George A

2010-03-01

Pseudomonas aeruginosa is an opportunistic pathogen that causes life-long pneumonia in individuals with cystic fibrosis (CF). These long-term infections are maintained by bacterial biofilm formation in the CF lung. We have recently developed a model of P. aeruginosa biofilm formation on cultured CF airway epithelial cells. Using this model, we discovered that mutation of a putative magnesium transporter gene, called mgtE, led to increased cytotoxicity of P. aeruginosa toward epithelial cells. This altered toxicity appeared to be dependent upon expression of the type III secretion system (T3SS). In this study, we found that mutation of mgtE results in increased T3SS gene transcription. Through epistasis analyses, we discovered that MgtE influences the ExsE-ExsC-ExsD-ExsA gene regulatory system of T3SS by either directly or indirectly inhibiting ExsA activity. While variations in calcium levels modulate T3SS gene expression in P. aeruginosa, we found that addition of exogenous magnesium did not inhibit T3SS activity. Furthermore, mgtE variants that were defective for magnesium transport could still complement the cytotoxicity effect. Thus, the magnesium transport function of MgtE does not fully explain the regulatory effects of MgtE on cytotoxicity. Overall, our results indicate that MgtE modulates expression of T3SS genes.

US Cystic Fibrosis Foundation and European Cystic Fibrosis Society consensus recommendations for the management of non-tuberculous mycobacteria in individuals with cystic fibrosis.

PubMed

Floto, R Andres; Olivier, Kenneth N; Saiman, Lisa; Daley, Charles L; Herrmann, Jean-Louis; Nick, Jerry A; Noone, Peadar G; Bilton, Diana; Corris, Paul; Gibson, Ronald L; Hempstead, Sarah E; Koetz, Karsten; Sabadosa, Kathryn A; Sermet-Gaudelus, Isabelle; Smyth, Alan R; van Ingen, Jakko; Wallace, Richard J; Winthrop, Kevin L; Marshall, Bruce C; Haworth, Charles S

2016-01-01

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause chronic pulmonary infection, particularly in individuals with pre-existing inflammatory lung disease such as cystic fibrosis (CF). Pulmonary disease caused by NTM has emerged as a major threat to the health of individuals with CF but remains difficult to diagnose and problematic to treat. In response to this challenge, the US Cystic Fibrosis Foundation (CFF) and the European Cystic Fibrosis Society (ECFS) convened an expert panel of specialists to develop consensus recommendations for the screening, investigation, diagnosis and management of NTM pulmonary disease in individuals with CF. Nineteen experts were invited to participate in the recommendation development process. Population, Intervention, Comparison, Outcome (PICO) methodology and systematic literature reviews were employed to inform draft recommendations. An anonymous voting process was used by the committee to reach consensus. All committee members were asked to rate each statement on a scale of: 0, completely disagree, to 9, completely agree; with 80% or more of scores between 7 and 9 being considered 'good' agreement. Additionally, the committee solicited feedback from the CF communities in the USA and Europe and considered the feedback in the development of the final recommendation statements. Three rounds of voting were conducted to achieve 80% consensus for each recommendation statement. Through this process, we have generated a series of pragmatic, evidence-based recommendations for the screening, investigation, diagnosis and treatment of NTM infection in individuals with CF as an initial step in optimising management for this challenging condition. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Modifier gene study of meconium ileus in cystic fibrosis: statistical considerations and gene mapping results

PubMed Central

Dorfman, Ruslan; Li, Weili; Sun, Lei; Lin, Fan; Wang, Yongqian; Sandford, Andrew; Paré, Peter D.; McKay, Karen; Kayserova, Hana; Piskackova, Tereza; Macek, Milan; Czerska, Kamila; Sands, Dorota; Tiddens, Harm; Margarit, Sonia; Repetto, Gabriela; Sontag, Marci K.; Accurso, Frank J.; Blackman, Scott; Cutting, Garry R.; Tsui, Lap-Chee; Corey, Mary; Durie, Peter; Zielenski, Julian; Strug, Lisa J.

2010-01-01

Cystic fibrosis (CF) is a monogenic disease due to mutations in the CFTR gene. Yet, variability in CF disease presentation is presumed to be affected by modifier genes, such as those recently demonstrated for the pulmonary aspect. Here, we conduct a modifier gene study for meconium ileus (MI), an intestinal obstruction that occurs in 16–20% of CF newborns, providing linkage and association results from large family and case–control samples. Linkage analysis of modifier traits is different than linkage analysis of primary traits on which a sample was ascertained. Here, we articulate a source of confounding unique to modifier gene studies and provide an example of how one might overcome the confounding in the context of linkage studies. Our linkage analysis provided evidence of a MI locus on chromosome 12p13.3, which was segregating in up to 80% of MI families with at least one affected offspring (HLOD = 2.9). Fine mapping of the 12p13.3 region in a large case–control sample of pancreatic insufficient Canadian CF patients with and without MI pointed to the involvement of ADIPOR2 in MI (p = 0.002). This marker was substantially out of Hardy–Weinberg equilibrium in the cases only, and provided evidence of a cohort effect. The association with rs9300298 in the ADIPOR2 gene at the 12p13.3 locus was replicated in an independent sample of CF families. A protective locus, using the phenotype of no-MI, mapped to 4q13.3 (HLOD = 3.19), with substantial heterogeneity. A candidate gene in the region, SLC4A4, provided preliminary evidence of association (p = 0.002), warranting further follow-up studies. Our linkage approach was used to direct our fine-mapping studies, which uncovered two potential modifier genes worthy of follow-up. PMID:19662435

Targeting autophagy as a novel strategy for facilitating the therapeutic action of potentiators on ΔF508 cystic fibrosis transmembrane conductance regulator

PubMed Central

Luciani, Alessandro; Villella, Valeria Rachela; Esposito, Speranza; Gavina, Manuela; Russo, Ilaria; Silano, Marco; Guido, Stefano; Pettoello-Mantovani, Massimo; Carnuccio, Rosa; Scholte, Bob; De Matteis, Antonella; Maiuri, Maria Chiara; Raia, Valeria; Luini, Alberto; Kroemer, Guido; Maiuri, Luigi

2012-01-01

Channel activators (potentiators) of cystic fibrosis (CF) transmembrane conductance regulator (CFTR), can be used for the treatment of the small subset of CF patients that carry plasma membrane-resident CFTR mutants. However, approximately 90% of CF patients carry the misfolded ΔF508-CFTR and are poorly responsive to potentiators, because ΔF508-CFTR is intrinsically unstable at the plasma membrane (PM) even if rescued by pharmacological correctors. We have demonstrated that human and mouse CF airways are autophagy deficient due to functional sequestration of BECN1 and that the tissue transglutaminase-2 inhibitor, cystamine, or antioxidants restore BECN1-dependent autophagy and reduce SQSTM1/p62 levels, thus favoring ΔF508-CFTR trafficking to the epithelial surface. Here, we investigated whether these treatments could facilitate the beneficial action of potentiators on ΔF508-CFTR homozygous airways. Cystamine or the superoxide dismutase (SOD)/catalase-mimetic EUK-134 stabilized ΔF508-CFTR at the plasma membrane of airway epithelial cells and sustained the expression of CFTR at the epithelial surface well beyond drug withdrawal, overexpressing BECN1 and depleting SQSTM1. This facilitates the beneficial action of potentiators in controlling inflammation in ex vivo ΔF508-CFTR homozygous human nasal biopsies and in vivo in mouse ΔF508-CFTR lungs. Direct depletion of Sqstm1 by shRNAs in vivo in ΔF508-CFTR mice synergized with potentiators in sustaining surface CFTR expression and suppressing inflammation. Cystamine pre-treatment restored ΔF508-CFTR response to the CFTR potentiators genistein, Vrx-532 or Vrx-770 in freshly isolated brushed nasal epithelial cells from ΔF508-CFTR homozygous patients. These findings delineate a novel therapeutic strategy for the treatment of CF patients with the ΔF508-CFTR mutation in which patients are first treated with cystamine and subsequently pulsed with CFTR potentiators. PMID:22874563

Targeting autophagy as a novel strategy for facilitating the therapeutic action of potentiators on ΔF508 cystic fibrosis transmembrane conductance regulator.

PubMed

Luciani, Alessandro; Villella, Valeria Rachela; Esposito, Speranza; Gavina, Manuela; Russo, Ilaria; Silano, Marco; Guido, Stefano; Pettoello-Mantovani, Massimo; Carnuccio, Rosa; Scholte, Bob; De Matteis, Antonella; Maiuri, Maria Chiara; Raia, Valeria; Luini, Alberto; Kroemer, Guido; Maiuri, Luigi

2012-11-01

Channel activators (potentiators) of cystic fibrosis (CF) transmembrane conductance regulator (CFTR), can be used for the treatment of the small subset of CF patients that carry plasma membrane-resident CFTR mutants. However, approximately 90% of CF patients carry the misfolded ΔF508-CFTR and are poorly responsive to potentiators, because ΔF508-CFTR is intrinsically unstable at the plasma membrane (PM) even if rescued by pharmacological correctors. We have demonstrated that human and mouse CF airways are autophagy deficient due to functional sequestration of BECN1 and that the tissue transglutaminase-2 inhibitor, cystamine, or antioxidants restore BECN1-dependent autophagy and reduce SQSTM1/p62 levels, thus favoring ΔF508-CFTR trafficking to the epithelial surface. Here, we investigated whether these treatments could facilitate the beneficial action of potentiators on ΔF508-CFTR homozygous airways. Cystamine or the superoxide dismutase (SOD)/catalase-mimetic EUK-134 stabilized ΔF508-CFTR at the plasma membrane of airway epithelial cells and sustained the expression of CFTR at the epithelial surface well beyond drug withdrawal, overexpressing BECN1 and depleting SQSTM1. This facilitates the beneficial action of potentiators in controlling inflammation in ex vivo ΔF508-CFTR homozygous human nasal biopsies and in vivo in mouse ΔF508-CFTR lungs. Direct depletion of Sqstm1 by shRNAs in vivo in ΔF508-CFTR mice synergized with potentiators in sustaining surface CFTR expression and suppressing inflammation. Cystamine pre-treatment restored ΔF508-CFTR response to the CFTR potentiators genistein, Vrx-532 or Vrx-770 in freshly isolated brushed nasal epithelial cells from ΔF508-CFTR homozygous patients. These findings delineate a novel therapeutic strategy for the treatment of CF patients with the ΔF508-CFTR mutation in which patients are first treated with cystamine and subsequently pulsed with CFTR potentiators.

Activation of 3-Phosphoinositide-dependent Kinase 1 (PDK1) and Serum- and Glucocorticoid-induced Protein Kinase 1 (SGK1) by Short-chain Sphingolipid C4-ceramide Rescues the Trafficking Defect of ΔF508-Cystic Fibrosis Transmembrane Conductance Regulator (ΔF508-CFTR)*

PubMed Central

Caohuy, Hung; Yang, Qingfeng; Eudy, Yvonne; Ha, Thien-An; Xu, Andrew E.; Glover, Matthew; Frizzell, Raymond A.; Jozwik, Catherine; Pollard, Harvey B.

2014-01-01

Cystic fibrosis (CF) is due to a folding defect in the CF transmembrane conductance regulator (CFTR) protein. The most common mutation, ΔF508, prevents CFTR from trafficking to the apical plasma membrane. Here we show that activation of the PDK1/SGK1 signaling pathway with C4-ceramide (C4-CER), a non-toxic small molecule, functionally corrects the trafficking defect in both cultured CF cells and primary epithelial cell explants from CF patients. The mechanism of C4-CER action involves a series of mutual autophosphorylation and phosphorylation events between PDK1 and SGK1. Detailed mechanistic studies indicate that C4-CER initially induces autophosphorylation of SGK1 at Ser422. SGK1[Ser(P)422] and C4-CER coincidently bind PDK1 and permit PDK1 to autophosphorylate at Ser241. Then PDK1[Ser(P)241] phosphorylates SGK1[Ser(P)422] at Thr256 to generate fully activated SGK1[Ser422, Thr(P)256]. SGK1[Ser(P)422,Thr(P)256] phosphorylates and inactivates the E3 ubiquitin ligase Nedd4-2. ΔF508-CFTR is thus free to traffic to the plasma membrane. Importantly, C4-CER-mediated activation of both PDK1 and SGK1 is independent of the PI3K/Akt/mammalian target of rapamycin signaling pathway. Physiologically, C4-CER significantly increases maturation and stability of ΔF508-CFTR (t½ ∼10 h), enhances cAMP-activated chloride secretion, and suppresses hypersecretion of interleukin-8 (IL-8). We suggest that candidate drugs for CF directed against the PDK1/SGK1 signaling pathway, such as C4-CER, provide a novel therapeutic strategy for a life-limiting disorder that affects one child, on average, each day. PMID:25384981

Determinants of health-related quality of life in polish patients with CF - adolescents' and parents' perspectives.

PubMed

Borawska-Kowalczyk, Urszula; Sands, Dorota

2015-01-01

1. Evaluation of health-related quality of life (HRQOL) in adolescents with cystic fibrosis (CF). 2. Evaluation of HRQOL in children with CF from the parents' perspective. 3. Evaluation of the relationship between HRQOL and both medical and psychosocial factors. Health-related quality of life was measured with the Cystic Fibrosis Questionnaire - Revised. Seventy patients with cystic fibrosis, aged 14-18 years completed the version for adolescents and adults (CFQ-R 14⁺ and 70 parents of children aged 6-13 years filled out the version for parents (CFQ-R 6-13). Scores ranged from 0 to 100, with higher scores indicating a better quality of life. Disease severity was assessed by lung function test, nutritional status, chronic Pseudomonas aeruginosa infection and type of CFTR gene mutation. Social indices i.e. the patient's school attendance and the parent's work status were collected. In the adolescents' opinion, Eating problems and Digestive functioning got the highest rate, whereas Vitality, Treatment burden, Health perceptions and Weight got the lowest. Boys estimated their Physical functioning significantly higher than girls. When evaluating their children's quality of life, parents granted the highest score to Physical, Respiratory and Digestive functioning and the lowest results were attributed to Treatment burden. Nutritional status and lung function impairment turned out to be predictors of some other domains but not psychosocial ones. The chronic Pseudomonas aeruginosa infection had an influence on several quality of life areas from the parents' perspective. School attendance had a significant impact on many aspects of the adolescents' functioning. 1. The study revealed that the health-related quality of life of CF children and adolescents is moderately good. 2. Digestive functioning was one of the highest scored domains, while Treatment burden was one of the lowest, according to both the adolescents' and the parents' perception. 3. The potential impact of disease severity was clearly marked in the group of younger children, whose health related quality of life was assessed by the parents. Self-evaluation conducted by adolescents was more subjective. 4. School attendace was an important factor of the quality of life. Further research is required in order to find other psychosocial indices.

Improvement in exercise duration, lung function and well-being in G551D-cystic fibrosis patients: a double-blind, placebo-controlled, randomized, cross-over study with ivacaftor treatment.

PubMed

Edgeworth, Deirdre; Keating, Dominic; Ellis, Matthew; Button, Brenda; Williams, Elyssa; Clark, Denise; Tierney, Audrey; Heritier, Stephane; Kotsimbos, Tom; Wilson, John

2017-08-01

G551D, a mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, results in impaired chloride channel function in cystic fibrosis (CF) with multiple end-organ manifestations. The effect of ivacaftor, a CFTR-potentiator, on exercise capacity in CF is unknown. Twenty G551D-CF patients were recruited to a single-centre, double-blind, placebo-controlled, 28-day crossover study of ivacaftor. Variables measured included percentage change from baseline (%Δ) of V O 2 max (maximal oxygen consumption, primary outcome) during cardiopulmonary exercise testing (CPET), relevant other CPET physiological variables, lung function, body mass index (BMI), sweat chloride and disease-specific health related quality of life (QOL) measures (CFQ-R and Alfred Wellness (AWEscore)). %Δ V O 2 max was unchanged compared with placebo as was %Δminute ventilation. However, %Δexercise time (mean 7.3, CI 0.5-14,1, P =0.0222) significantly increased as did %ΔFEV 1 (11.7%, range 5.3-18.1, P <0·005) and %ΔBMI (1.2%, range 0.1-2.3, P =0·0393) whereas sweat chloride decreased (mean -43.4; range -55.5-18.1 mmol·l -1 , P <0·005). Total and activity based domains in both CFQ-R and AWEscore also increased. A positive treatment effect on spirometry, BMI (increased), SCT (decreased) and total and activity based CF-specific QOL measures was expected. However, the lack of discernible improvement in V O 2 max and VE despite other positive changes including spirometric lung function and exercise time with a 28-day ivacaftor intervention suggests that ventilatory parameters are not the sole driver of change in exercise capacity in this study cohort. Investigation over a more prolonged period may delineate the potential interdependencies of the observed discordances over time. ClinicalTrials.gov-NCT01937325. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Analytical validation of BRAF mutation testing from circulating free DNA using the amplification refractory mutation testing system.

PubMed

Aung, Kyaw L; Donald, Emma; Ellison, Gillian; Bujac, Sarah; Fletcher, Lynn; Cantarini, Mireille; Brady, Ged; Orr, Maria; Clack, Glen; Ranson, Malcolm; Dive, Caroline; Hughes, Andrew

2014-05-01

BRAF mutation testing from circulating free DNA (cfDNA) using the amplification refractory mutation testing system (ARMS) holds potential as a surrogate for tumor mutation testing. Robust assay validation is needed to establish the optimal clinical matrix for measurement and cfDNA-specific mutation calling criteria. Plasma- and serum-derived cfDNA samples from 221 advanced melanoma patients were analyzed for BRAF c.1799T>A (p.V600E) mutation using ARMS in two stages in a blinded fashion. cfDNA-specific mutation calling criteria were defined in stage 1 and validated in stage 2. cfDNA concentrations in serum and plasma, and the sensitivities and specificities of BRAF mutation detection in these two clinical matrices were compared. Sensitivity of BRAF c.1799T>A (p.V600E) mutation detection in cfDNA was increased by using mutation calling criteria optimized for cfDNA (these criteria were adjusted from those used for archival tumor biopsies) without compromising specificity. Sensitivity of BRAF mutation detection in serum was 44% (95% CI, 35% to 53%) and in plasma 52% (95% CI, 43% to 61%). Specificity was 96% (95% CI, 90% to 99%) in both matrices. Serum contains significantly higher total cfDNA than plasma, whereas the proportion of tumor-derived mutant DNA was significantly higher in plasma. Using mutation calling criteria optimized for cfDNA improves sensitivity of BRAF c.1799T>A (p.V600E) mutation detection. The proportion of tumor-derived cfDNA in plasma was significantly higher than in serum. Copyright © 2014 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Cost(s) of caring for patients with cystic fibrosis.

PubMed

Orenstein, David M; Abood, Robert N

2018-06-01

Cystic fibrosis (CF) has received a lot of attention in the past few years because of increased longevity and the emergence of ground-breaking new drugs targeting the molecular and cellular defects, making a huge clinical difference, and - not incidentally - carrying massive price tags. The prices of these new drugs make the question of overall costs of CF care highly relevant. This article reviews recent developments in CF science and treatment, and highlights areas that contribute to costs of CF care, emphasizing how these costs have increased. This article should help the pediatrician stay abreast of high points of CF care, with an awareness of the factors that wield the biggest influence on overall costs, to patients, families and the US healthcare system.

Cystic fibrosis, common variable immunodeficiency and Aspergers syndrome: an immunological and behavioural challenge.

PubMed

Chotirmall, S H; Low, T B; Hassan, T; Branagan, P; Kernekamp, C; Flynn, M G; Gunaratnam, C; McElvaney, N G

2011-06-01

Cystic fibrosis (CF) is of particular importance in Ireland as the Irish population has both the highest incidence (2.98/10,000) and the highest carrier rate (1 in 19) in the world. Primary immunodeficiency has not been previously reported as co-existing with CF. We report a unique case of CF associated with a primary immunodeficiency syndrome--common variable immunodeficiency (CVID). Our patient has CF, CVID and the additional comorbidity of Aspergers syndrome. The challenges inherent in diagnosing and treating such a case are outlined herein and the successful management of this case is evidenced by the well-preserved lung function of our patient.

Pathophysiology of cystic fibrosis and drugs used in associated digestive tract diseases

PubMed Central

Haack, Adriana; Aragão, Giselle Gonçalves; Novaes, Maria Rita Carvalho Garbi

2013-01-01

Cystic fibrosis (CF) causes chronic infections in the respiratory tract and alters the digestive tract. This paper reviews the most important aspects of drug treatment and changes in the digestive tract of patients with CF. This is a review of the literature, emphasizing the discoveries made within the last 15 years by analyzing scientific papers published in journals indexed in the Scientific Electronic Library Online, Sciences Information, United States National Library of Medicine and Medical Literature Analysis and Retrieval System Online databases, both in English and Portuguese, using the key words: cystic fibrosis, medication, therapeutic, absorption, digestion. Randomized, observational, experimental, and epidemiological clinical studies were selected, among others, with statistical significance of 5%. This review evaluates the changes found in the digestive tract of CF patients including pancreatic insufficiency, constipation and liver diseases. Changes in nutritional status are also described. Clinical treatment, nutritional supplementation and drug management were classified in this review as essential to the quality of life of CF patients, and became available through public policies for monitoring and treating CF. The information gathered on CF and a multi professional approach to the disease is essential in the treatment of these patients. PMID:24379572

Practical Guidelines: Lung Transplantation in Patients with Cystic Fibrosis

PubMed Central

Hirche, T. O.; Knoop, C.; Hebestreit, H.; Shimmin, D.; Solé, A.; Elborn, J. S.; Ellemunter, H.; Aurora, P.; Hogardt, M.; Wagner, T. O. F.; ECORN-CF Study Group

2014-01-01

There are no European recommendations on issues specifically related to lung transplantation (LTX) in cystic fibrosis (CF). The main goal of this paper is to provide CF care team members with clinically relevant CF-specific information on all aspects of LTX, highlighting areas of consensus and controversy throughout Europe. Bilateral lung transplantation has been shown to be an important therapeutic option for end-stage CF pulmonary disease. Transplant function and patient survival after transplantation are better than in most other indications for this procedure. Attention though has to be paid to pretransplant morbidity, time for referral, evaluation, indication, and contraindication in children and in adults. This review makes extensive use of specific evidence in the field of lung transplantation in CF patients and addresses all issues of practical importance. The requirements of pre-, peri-, and postoperative management are discussed in detail including bridging to transplant and postoperative complications, immune suppression, chronic allograft dysfunction, infection, and malignancies being the most important. Among the contributors to this guiding information are 19 members of the ECORN-CF project and other experts. The document is endorsed by the European Cystic Fibrosis Society and sponsored by the Christiane Herzog Foundation. PMID:24800072

Aspergillus-induced superoxide production by cystic fibrosis phagocytes is associated with disease severity.

PubMed

Brunel, Shan F; Willment, Janet A; Brown, Gordon D; Devereux, Graham; Warris, Adilia

2018-04-01

Aspergillus fumigatus infects up to 50% of cystic fibrosis (CF) patients and may play a role in progressive lung disease. As cystic fibrosis transmembrane conductance regulator is expressed in cells of the innate immune system, we hypothesised that impaired antifungal immune responses play a role in CF-related Aspergillus lung disease. Peripheral blood mononuclear cells, polymorphonuclear cells (PMN) and monocytes were isolated from blood samples taken from CF patients and healthy volunteers. Live-cell imaging and colorimetric assays were used to assess antifungal activity in vitro . Production of reactive oxygen species (ROS) was measured using luminol-induced chemiluminescence and was related to clinical metrics as collected by case report forms. CF phagocytes are as effective as those from healthy controls with regards to phagocytosis, killing and restricting germination of A. fumigatus conidia. ROS production by CF phagocytes was up to four-fold greater than healthy controls (p<0.05). This effect could not be replicated in healthy phagocytes by priming with lipopolysaccharide or serum from CF donors. Increased production of ROS against A. fumigatus by CF PMN was associated with an increased number of clinical exacerbations in the previous year (p=0.007) and reduced lung function (by forced expiratory volume in 1 s) (p=0.014). CF phagocytes mount an intrinsic exaggerated release of ROS upon A. fumigatus stimulation which is associated with clinical disease severity.

Aspergillus-induced superoxide production by cystic fibrosis phagocytes is associated with disease severity

PubMed Central

Brunel, Shan F.; Brown, Gordon D.; Devereux, Graham; Warris, Adilia

2018-01-01

Aspergillus fumigatus infects up to 50% of cystic fibrosis (CF) patients and may play a role in progressive lung disease. As cystic fibrosis transmembrane conductance regulator is expressed in cells of the innate immune system, we hypothesised that impaired antifungal immune responses play a role in CF-related Aspergillus lung disease. Peripheral blood mononuclear cells, polymorphonuclear cells (PMN) and monocytes were isolated from blood samples taken from CF patients and healthy volunteers. Live-cell imaging and colorimetric assays were used to assess antifungal activity in vitro. Production of reactive oxygen species (ROS) was measured using luminol-induced chemiluminescence and was related to clinical metrics as collected by case report forms. CF phagocytes are as effective as those from healthy controls with regards to phagocytosis, killing and restricting germination of A. fumigatus conidia. ROS production by CF phagocytes was up to four-fold greater than healthy controls (p<0.05). This effect could not be replicated in healthy phagocytes by priming with lipopolysaccharide or serum from CF donors. Increased production of ROS against A. fumigatus by CF PMN was associated with an increased number of clinical exacerbations in the previous year (p=0.007) and reduced lung function (by forced expiratory volume in 1 s) (p=0.014). CF phagocytes mount an intrinsic exaggerated release of ROS upon A. fumigatus stimulation which is associated with clinical disease severity. PMID:29651422

Phenotypic and Genetic Characterization of Carbapenemase and ESBLs Producing Gram-negative Bacteria (GNB) Isolated from Patients with Cystic Fibrosis (CF) in Tehran Hospitals

PubMed Central

Vali, Parisa; Shahcheraghi, Fereshteh; Seyfipour, Maryam; Zamani, Maryam Alsadat; Allahyar, Mohammad Reza; Feizabadi, Mohammad Mehdi

2014-01-01

Background: Cystic Fibrosis (CF) is an autosomal recessive genetic disorder in white populations caused by mutation in a gene that encodes Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein. Since frequent respiratory tract infections are the major problem in patients with CF, obligation to identify the causative bacteria and determining their antibiotic resistance pattern is crucial. The purpose of this project was to detect Gram-negative bacteria (GNB) isolated from sputa of CF patients and to determine their antibiotic resistance pattern. Materials and Methods: The sputum of 52 CF patients, treated as inpatients at hospitals in Tehran, was obtained between November 2011 and June 2012. Samples cultured in selective and non-selective media and GNB recognized by biochemical tests. Antimicrobial susceptibility testing to cephalosporins, aminoglycosides and carbapenems was performed by disk diffusion method and MICs of them were measured. For phenotypic detection of carbapenemase and ESBLs production, the Modified Hodge test, double disk synergy test and the combined disk methods were performed. Subsequently, the genes encoding the extended spectrum beta-lactamases (blaPER, blaCTX-M) and carbapenemases (blaIMP-1, blaGES, blaKPC, blaNDM, blaVIM-1, blaVIM-2, blaSPM, blaSIM) in Gram negative bacteria were targeted among the resistant isolates by using PCR. PFGE was used to determine any genetic relationship among the Pseudomonas aeruginosa isolated from these patients. Results: Fifty five GNB were isolated from 52 sputum samples including Pseudomonas aeruginosa, Klebsiella ozaenae, Alcaligenes xylosoxidans, Achromobacter denitrificans, Klebsiella pneumonia and Stenotrophomonas maltophilia. The rates of resistance to different antibiotic were as follows: cefixime (%80), ceftriaxone (%43), ceftazidime (%45) and meropenem (%7). The prevalence of genes encoding the ESBLs and Carbapenemases among the the phenotypically positive strains were as follows: blaCTX-M (19), blaIMP-1 (2), blaVIM-1 (2) and blaVIM-2 (3) genes respectively. No other genes were detected. PFGE analysis revealed 8 genotypes. Six isolates had mutually 3 similar patterns. Conclusion: This study showed the existence of important ESBLs and carbapenemases genes among the GNB isolated from patients with CF. Continuous surveillance of ESBLs and Carbapenemases, also identification of their types, in bacteria isolated from these patients have an important clinical impact, since, it can often provide valuable information for effective infection control measures and for the choice of appropriate antimicrobial therapy. PMID:24596716

A Comparison of Family Adaptations to Having a Child with Cystic Fibrosis.

ERIC Educational Resources Information Center

Johnson, Mark C.; And Others

1985-01-01

Examines effect of cystic fibrosis (CF) on structure and social climate of the family using self-report scales and independent observations of family functioning. Families in which the child with CF was not the firstborn were found to be functioning more healthily than those in which the child was firstborn. (Author/NRB)

Clinical significance of plasma cell-free DNA mutations in PIK3CA, AKT1, and ESR1 gene according to treatment lines in ER-positive breast cancer.

PubMed

Takeshita, Takashi; Yamamoto, Yutaka; Yamamoto-Ibusuki, Mutsuko; Tomiguchi, Mai; Sueta, Aiko; Murakami, Keiichi; Iwase, Hirotaka

2018-02-26

The somatic activation of PI3K/AKT pathway mutations, PIK3CA and AKT1, and ESR1 mutations in plasma cell-free DNA (cfDNA) has been studied as a non-invasive procedure to quickly assess and monitor disease progression or therapeutic effect in breast cancer (BC) patients, but the clinical significance of these mutations in late treatment lines (TLs) remains unclear. The subjects of this study were a total of 251 plasma samples from 128 estrogen receptor-positive (ER+) BC patients. Of these plasma samples, 133 were from 73 primary BC (PBC) patients, and 118 plasma samples were from 68 metastatic BC (MBC) patients. We developed droplet digital PCR (ddPCR) assays to verify the clinical significance of PIK3CA, AKT1, and ESR1 mutations in these patients. cfDNA PIK3CA mutations were observed in 15.1% of the PBC patients, while a cfDNA AKT1 mutation was observed in 1.4% of patients, and cfDNA ESR1 mutations were observed in 2.7% of patients. Patients with detectable cfDNA PIK3CA mutations were not associated with clinical outcomes. According to the TL, the prevalence of the PIK3CA and ESR1 mutations in cfDNA were lower in early TLs compared with late TLs. In the early TL group, patients with cfDNA PIK3CA mutations had a shorter time to treatment failure (TTF) than patients without mutations (P = 0.035). However, there was no statistically significant difference between patients with or without cfDNA ESR1 mutations. However, in the late TL group, patients with cfDNA ESR1 mutations had a shorter TTF than patients without mutations (P = 0.048). However, there was no statistically significant difference between patients with or without cfDNA PIK3CA mutations. Since the prevalence of cfDNA AKT1 mutation is low in both PBC and MBC patients, the impact of AKT1 mutations on the prognosis remains unclear. We have demonstrated the difference in the clinical significance of the hotspot PIK3CA, AKT1, and ESR1 mutations in cfDNA for each TL in ER+ BC patients.

Defective innate immunity and hyperinflammation in newborn cystic fibrosis transmembrane conductance regulator-knockout ferret lungs.

PubMed

Keiser, Nicholas W; Birket, Susan E; Evans, Idil A; Tyler, Scott R; Crooke, Adrianne K; Sun, Xingshen; Zhou, Weihong; Nellis, Joseph R; Stroebele, Elizabeth K; Chu, Kengyeh K; Tearney, Guillermo J; Stevens, Mark J; Harris, J Kirk; Rowe, Steven M; Engelhardt, John F

2015-06-01

Mucociliary clearance (MCC) and submucosal glands are major components of airway innate immunity that have impaired function in cystic fibrosis (CF). Although both of these defense systems develop postnatally in the ferret, the lungs of newborn ferrets remain sterile in the presence of a functioning cystic fibrosis transmembrane conductance regulator gene. We evaluated several components of airway innate immunity and inflammation in the early CF ferret lung. At birth, the rates of MCC did not differ between CF and non-CF animals, but the height of the airway surface liquid was significantly reduced in CF newborn ferrets. CF ferrets had impaired MCC after 7 days of age, despite normal rates of ciliogenesis. Only non-CF ferrets eradicated Pseudomonas directly introduced into the lung after birth, whereas both genotypes could eradicate Staphylococcus. CF bronchoalveolar lavage fluid (BALF) had significantly lower antimicrobial activity selectively against Pseudomonas than non-CF BALF, which was insensitive to changes in pH and bicarbonate. Liquid chromatography-tandem mass spectrometry and cytokine analysis of BALF from sterile Caesarean-sectioned and nonsterile naturally born animals demonstrated CF-associated disturbances in IL-8, TNF-α, and IL-β, and pathways that control immunity and inflammation, including the complement system, macrophage functions, mammalian target of rapamycin signaling, and eukaryotic initiation factor 2 signaling. Interestingly, during the birth transition, IL-8 was selectively induced in CF BALF, despite no genotypic difference in bacterial load shortly after birth. These results suggest that newborn CF ferrets have defects in both innate immunity and inflammatory signaling that may be important in the early onset and progression of lung disease in these animals.

Defective Innate Immunity and Hyperinflammation in Newborn Cystic Fibrosis Transmembrane Conductance Regulator–Knockout Ferret Lungs

PubMed Central

Keiser, Nicholas W.; Birket, Susan E.; Evans, Idil A.; Tyler, Scott R.; Crooke, Adrianne K.; Sun, Xingshen; Zhou, Weihong; Nellis, Joseph R.; Stroebele, Elizabeth K.; Chu, Kengyeh K.; Tearney, Guillermo J.; Stevens, Mark J.; Harris, J. Kirk; Rowe, Steven M.

2015-01-01

Mucociliary clearance (MCC) and submucosal glands are major components of airway innate immunity that have impaired function in cystic fibrosis (CF). Although both of these defense systems develop postnatally in the ferret, the lungs of newborn ferrets remain sterile in the presence of a functioning cystic fibrosis transmembrane conductance regulator gene. We evaluated several components of airway innate immunity and inflammation in the early CF ferret lung. At birth, the rates of MCC did not differ between CF and non-CF animals, but the height of the airway surface liquid was significantly reduced in CF newborn ferrets. CF ferrets had impaired MCC after 7 days of age, despite normal rates of ciliogenesis. Only non-CF ferrets eradicated Pseudomonas directly introduced into the lung after birth, whereas both genotypes could eradicate Staphylococcus. CF bronchoalveolar lavage fluid (BALF) had significantly lower antimicrobial activity selectively against Pseudomonas than non-CF BALF, which was insensitive to changes in pH and bicarbonate. Liquid chromatography–tandem mass spectrometry and cytokine analysis of BALF from sterile Caesarean-sectioned and nonsterile naturally born animals demonstrated CF-associated disturbances in IL-8, TNF-α, and IL-β, and pathways that control immunity and inflammation, including the complement system, macrophage functions, mammalian target of rapamycin signaling, and eukaryotic initiation factor 2 signaling. Interestingly, during the birth transition, IL-8 was selectively induced in CF BALF, despite no genotypic difference in bacterial load shortly after birth. These results suggest that newborn CF ferrets have defects in both innate immunity and inflammatory signaling that may be important in the early onset and progression of lung disease in these animals. PMID:25317669

Surveying Cystic Fibrosis Care Centers to Assess Adoption of Infection Prevention and Control Recommendations.

PubMed

Saiman, Lisa; Zhou, Juyan J; Jiang, Xiaotong; Kosorok, Michael R; Muhlebach, Marianne S

2018-04-15

OBJECTIVEIn 2013, the Cystic Fibrosis (CF) Foundation developed an updated guideline for infection prevention and control (IP&C) practices for CF. We sought to assess the adoption of specific recommendations by CF care centers.METHODSDirectors of the 277 CF care centers in the United States were asked to complete a confidential online survey regarding the adoption of selected IP&C recommendations. Selected recommendations were those we considered less likely to be incorporated into a center's written IP&C policies.RESULTSCenter directors from 198 of 277 CF centers (71%) completed the survey between December 2015 and June 2016; pediatric and larger centers were more likely to do so. Overall, 70% have adopted ≥75% of the selected recommendations. As recommended, almost all provided education to CF center staff (98%) and patients and families (97%); fewer developed educational materials in collaboration with local IP&C teams (59%) and/or patients and families (37%). Among 108 centers with non-English-speaking patients, 65 (60%) provided educational materials in relevant languages. Most (74%) held group education events; of the 138 centers with in-person meetings, 45% allowed 1 individual with CF to attend, and 51% allowed no individuals with CF to attend. Most centers (93%) held outdoor events, and 84% allowed >1 individual with CF to attend. Audits of exam-room cleaning were performed by 49% of CF centers.CONCLUSIONSCystic fibrosis centers in the United States have adopted many of the recommendations addressed in this survey. Nonetheless, these findings suggest opportunities for improvement. More CF centers should provide education to non-English-speaking patients and families, and CF centers should perform audits of room cleaning.Infect Control Hosp Epidemiol. 2018:1-5.

Exercise training in children and adolescents with cystic fibrosis: theory into practice.

PubMed

Williams, Craig A; Benden, Christian; Stevens, Daniel; Radtke, Thomas

2010-01-01

Physical activity and exercise training play an important role in the clinical management of patients with cystic fibrosis (CF). Exercise training is more common and recognized as an essential part of rehabilitation programmes and overall CF care. Regular exercise training is associated with improved aerobic and anaerobic capacity, higher pulmonary function, and enhanced airway mucus clearance. Furthermore, patients with higher aerobic fitness have an improved survival. Aerobic and anaerobic training may have different effects, while the combination of both have been reported to be beneficial in CF. However, exercise training remains underutilised and not always incorporated into routine CF management. We provide an update on aerobic and anaerobic responses to exercise and general training recommendations in children and adolescents with CF. We propose that an active lifestyle and exercise training are an efficacious part of regular CF patient management.

Genetic evidence for heterogeneity in the etiology of CBAVD: Haplotype analysis in families

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerem, B.; Rave-Harel, N.; Goshen, R.

1994-09-01

Male infertility due to congenital aplasia of the vas deference (CBAVD) is present in almost all CF male patients. It is also found in 1-2% of infertile otherwise healthy males. Several studies have found that about 10% of males with CBAVD carry 2 CF mutations, 40% carry one mutation and 50% have no mutations. These results indicate that in some males CBAVD is caused by two mutated CF alleles. However, in cases of males with one or no identified CF mutations, the association between CBAVD and CF is unclear. We therefore performed, in addition to CF mutation analysis, an extendedmore » haplotype analysis in 7 families of CBAVD males (2 had 2 brothers with CBAVD). Our results show that in 6 of the families, the infertile males inherited different CF alleles than their fertile brothers. However, in 2 families, in which no CF mutations were as of yet identified, different results were found. In one family, 2 infertile brothers differed in their haplotypes: both inherited from their mother the same CF allele, while from their father they inherited different alleles. Furthermore, their fertile brother inherited the same CF alleles as one of his fertile brothers. In another family, 2 brothers, one with CBAVD and the other fertile, inherited the same 2 CFTR alleles. These results provide genetic evidence for heterogeneity in the etiology of CBAVD. In some families the CBAVD is caused by 2 CF mutations, in others it is caused by other mechanism(s): heterozygosity for a CF mutation influenced by different threshold levels, mutations in other gene(s), or interaction between the two.« less

Mini-guts in a dish: Perspectives of adult Cystic Fibrosis (CF) patients and parents of young CF patients on organoid technology.

PubMed

Boers, Sarah N; de Winter-de Groot, Karin M; Noordhoek, Jacquelien; Gulmans, Vincent; van der Ent, Cornelis K; van Delden, Johannes J M; Bredenoord, Annelien L

2018-03-06

Organoid technology enables the cultivation of human tissues in a dish. Its precision medicine potential could revolutionize the Cystic Fibrosis (CF) field. We provide a first thematic exploration of the patient perspective on organoid technology to set the further research agenda, which is necessary for responsible development of this ethically challenging technology. 23 semi-structured qualitative interviews with 14 Dutch adult CF patients and 12 parents of young CF patients to examine their experiences, opinions, and attitudes regarding organoid technology. Four themes emerged: (1) Respondents express a close as well as a distant relationship to organoids; (2) the open-endedness of organoid technology sparks hopes and concerns, (3) commercial use evokes cautiousness. (4) Respondents mention the importance of sound consent procedures, long-term patient engagement, responsible stewardship, and stringent conditions for commercial use. The precision medicine potential of organoid technology can only be realized if the patient perspective is taken adequately into account. Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Costs and health-related quality of life of patients with cystic fibrosis and their carers in France.

PubMed

Chevreul, Karine; Berg Brigham, Karen; Michel, Morgane; Rault, Gilles

2015-05-01

Our goal was to provide data on the economic burden and health-related quality of life (HRQoL) associated with cystic fibrosis (CF) in France. A retrospective cross-sectional study was carried out on adults and children with CF, who completed an anonymous questionnaire regarding their socio-demographic characteristics, healthcare consumption and presence of a carer. Costs were calculated with a bottom-up approach, and HRQoL was assessed using EQ-5D. 82 adults and 158 children were included. The total average annual cost of CF was €29,746 per patient. Total costs were higher in adults than in children and increased with disease duration. The average utility was lower in adults (0.667 vs. 0.783 in children, p=0.0015). The HRQoL of carers was also affected (0.742 and 0.765 for carers of adults and children with CF, respectively). Our study highlights the burden of CF in terms of costs and decreased HRQoL for both patients and carers. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Pharmacokinetics and Tolerability of Oral Sildenafil in Adults with Cystic Fibrosis Lung Disease

PubMed Central

Taylor-Cousar, JL; Wiley, C; Felton, LA; St Clair, C; Jones, M; Curran-Everett, D; Poch, K; Nichols, DP; Solomon, GM; Saavedra, MT; Accurso, FJ; Nick, JA

2014-01-01

Rationale Airway inflammation is central to cystic fibrosis (CF) pathophysiology. Pre-clinical models have shown that phosphodiesterase inhibitors (PDEi) like sildenafil have anti-inflammatory activity. PDEi have not been studied in CF subjects. Objectives We evaluated the pharmacokinetics, tolerability, and safety of sildenafil in subjects with CF. Sputum biomarkers were used to explore efficacy. Methods An open-label pilot study of oral sildenafil administration was conducted in adults with mild to moderate CF lung disease. Subjects received oral sildenafil 20 or 40 mg p.o. t.i.d. for 6 weeks. Measurements and Main Results Twenty subjects completed the study. Estimated elimination rate constants were statistically different in subjects with CF compared to previously published non-CF subjects. Side effects were generally mild. There were no drug-related serious adverse events. Sputum neutrophil elastase activity decreased. Conclusions Subjects with CF may eliminate sildenafil at a faster rate than non-CF subjects. Sildenafil administration was safe in subjects with CF, and decreased sputum elastase activity. Sildenafil warrants further study as an anti-inflammatory in CF. PMID:25466700

Pharmacists' perspectives on monitoring adherence to treatment in Cystic Fibrosis.

PubMed

Mooney, Karen; Ryan, Cristín; Downey, Damian G

2016-04-01

Cystic Fibrosis (CF) management requires complex treatment regimens but adherence to treatment is poor and has negative health implications. There are various methods of measuring adherence, but little is known regarding the extent of adherence measurement in CF centres throughout the UK and Ireland. To determine the adherence monitoring practices in CF centres throughout the UK and Ireland, and to establish CF pharmacists' views on these practices. UK and Ireland Cystic Fibrosis Pharmacists' Group's annual meeting (2014). A questionnaire was designed, piloted and distributed to pharmacists attending the UK and Ireland Cystic Fibrosis Pharmacists' Group's annual meeting (2014). The main outcome measures were the methods of inhaled/nebulised antibiotic supply and the methods used to measure treatment adherence in CF centres. The questionnaire also ascertained the demographic information of participating pharmacists. Closed question responses were analysed using descriptive statistics. Open questions were analysed using content analysis. Twenty-one respondents (84 % response) were included in the analysis and were mostly from English centres (66.7 %). Detailed records of patients receiving their inhaled/nebulised antibiotics were lacking. Adherence was most commonly described to be measured at 'every clinic visit' (28.6 %) and 'occasionally' (28.6 %). Patient self-reported adherence was the most commonly used method of measuring adherence in practice (90.5 %). The availability of electronic adherence monitoring in CF centres did not guarantee its use. Pharmacists attributed an equal professional responsibility for adherence monitoring in CF to Consultants, Nurses and Pharmacists. Seventy-six percent of pharmacists felt that the current adherence monitoring practices within their own unit were inadequate and associated with the absence of sufficient specialist CF pharmacist involvement. Many suggested that greater specialist pharmacist involvement could facilitate improved adherence monitoring. Current adherence knowledge is largely based on self-report. Further work is required to establish the most appropriate method of adherence monitoring in CF centres, to improve the recording of adherence and to understand the impact of increased specialist pharmacist involvement on that adherence.

The CF-CARES primary palliative care model: A CF-specific structured assessment of symptoms, distress, and coping.

PubMed

Friedman, Deborah; Linnemann, Rachel W; Altstein, Lily L; Islam, Suhayla; Bach, Kieu-Tram; Lamb, Chelsea; Volpe, John; Doolittle, Caitlin; St John, Anita; O'Malley, Patricia J; Sawicki, Gregory S; Georgiopoulos, Anna M; Yonker, Lael M; Moskowitz, Samuel M

2018-01-01

Current palliative care tools do not address distressing chronic symptoms that are most relevant to cystic fibrosis. A CF-specific structured assessment based on a primary palliative care framework was administered to 41 adolescents and adults with CF. Descriptive and correlational analyses were conducted. Patients reported numerous physical and psychological symptoms (mean of 10 per patient), with psychological symptoms rated as more distressing. Anxiety (34%) and depression (44%) were prevalent and correlated with distress attributable to physical symptoms and difficulty with CF self-management, but did not correlate with disease severity. Individuals with CF, regardless of disease severity, face challenges managing symptom burden. Frequently reported symptoms are not consistently associated with distress, suggesting the importance of individualized evaluation. The CF-CARES (Coping, goal Assessment, and Relief from Evolving CF Symptoms) primary palliative care assessment model provides a framework for patients experiencing chronic symptoms to explore interventional options with their clinicians. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Free DNA in Cystic Fibrosis Airway Fluids Correlates with Airflow Obstruction

PubMed Central

Marcos, Veronica; Zhou-Suckow, Zhe; Önder Yildirim, Ali; Bohla, Alexander; Hector, Andreas; Vitkov, Ljubomir; Krautgartner, Wolf Dietrich; Stoiber, Walter; Griese, Matthias; Eickelberg, Oliver; Mall, Marcus A.; Hartl, Dominik

2015-01-01

Chronic obstructive lung disease determines morbidity and mortality of patients with cystic fibrosis (CF). CF airways are characterized by a nonresolving neutrophilic inflammation. After pathogen contact or prolonged activation, neutrophils release DNA fibres decorated with antimicrobial proteins, forming neutrophil extracellular traps (NETs). NETs have been described to act in a beneficial way for innate host defense by bactericidal, fungicidal, and virucidal actions. On the other hand, excessive NET formation has been linked to the pathogenesis of autoinflammatory and autoimmune disease conditions. We quantified free DNA structures characteristic of NETs in airway fluids of CF patients and a mouse model with CF-like lung disease. Free DNA levels correlated with airflow obstruction, fungal colonization, and CXC chemokine levels in CF patients and CF-like mice. When viewed in combination, our results demonstrate that neutrophilic inflammation in CF airways is associated with abundant free DNA characteristic for NETosis, and suggest that free DNA may be implicated in lung function decline in patients with CF. PMID:25918476

Metagenomic Analysis of Respiratory Tract DNA Viral Communities in Cystic Fibrosis and Non-Cystic Fibrosis Individuals

PubMed Central

Haynes, Matthew; Schmieder, Robert; Angly, Florent E.; Silva, Joas; Tammadoni, Sassan; Nosrat, Bahador; Conrad, Douglas; Rohwer, Forest

2009-01-01

The human respiratory tract is constantly exposed to a wide variety of viruses, microbes and inorganic particulates from environmental air, water and food. Physical characteristics of inhaled particles and airway mucosal immunity determine which viruses and microbes will persist in the airways. Here we present the first metagenomic study of DNA viral communities in the airways of diseased and non-diseased individuals. We obtained sequences from sputum DNA viral communities in 5 individuals with cystic fibrosis (CF) and 5 individuals without the disease. Overall, diversity of viruses in the airways was low, with an average richness of 175 distinct viral genotypes. The majority of viral diversity was uncharacterized. CF phage communities were highly similar to each other, whereas Non-CF individuals had more distinct phage communities, which may reflect organisms in inhaled air. CF eukaryotic viral communities were dominated by a few viruses, including human herpesviruses and retroviruses. Functional metagenomics showed that all Non-CF viromes were similar, and that CF viromes were enriched in aromatic amino acid metabolism. The CF metagenomes occupied two different metabolic states, probably reflecting different disease states. There was one outlying CF virome which was characterized by an over-representation of Guanosine-5′-triphosphate,3′-diphosphate pyrophosphatase, an enzyme involved in the bacterial stringent response. Unique environments like the CF airway can drive functional adaptations, leading to shifts in metabolic profiles. These results have important clinical implications for CF, indicating that therapeutic measures may be more effective if used to change the respiratory environment, as opposed to shifting the taxonomic composition of resident microbiota. PMID:19816605

Cystic Fibrosis Transmembrane Regulator Modulators: Implications for the Management of Depression and Anxiety in Cystic Fibrosis.

PubMed

Talwalkar, Jaideep S; Koff, Jonathan L; Lee, Hochang B; Britto, Clemente J; Mulenos, Arielle M; Georgiopoulos, Anna M

Individuals with cystic fibrosis (CF) are at high risk for depression and anxiety, which are associated with worse medical outcomes. Novel therapies for CF hold great promise for improving physical health, but the effects of these therapies on mental health remain poorly understood. This review aims to familiarize psychiatrists with the potential effect of novel CF therapies on depression and anxiety. We discuss novel therapies that directly target the mutant CF protein, the CF transmembrane regulator (CFTR), which are called CFTR modulators. We summarize depression and anxiety screening and treatment guidelines under implementation in accredited CF centers. Case vignettes highlight the complexities of caring for individuals with CF with comorbid depression and anxiety, including patients experiencing worsening depression and anxiety proximate to initiation of CFTR modulator therapy, and management of drug-drug interactions. Although CFTR modulator therapies provide hope for improving clinical outcomes, worsening depression and anxiety occurs in some patients when starting these novel agents. This phenomenon may be multifactorial, with hypothesized contributions from CFTR modulator-psychotropic medication interactions, direct effects of CFTR modulators on central nervous system function, the psychologic effect of starting a potentially life-altering drug, and typical triggers of depression and anxiety such as stress, pain, and inflammation. The medical and psychiatric complexity of many individuals with CF warrants more direct involvement of mental health specialists on the multidisciplinary CF team. Inclusion of mental health variables in patients with CF registries will facilitate further examination at an epidemiologic level. Copyright © 2017 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.

Pulmonary complications of endocrine and metabolic disorders.

PubMed

Milla, Carlos E; Zirbes, Jacquelyn

2012-03-01

There are many important respiratory manifestations of endocrine and metabolic diseases in children. Acute and chronic pulmonary infections are the most common respiratory abnormalities in patients with diabetes mellitus, although cardiogenic and non-cardiogenic pulmonary oedema are also possible. Pseudohypoaldosteronism type 1 may be indistinguishable from cystic fibrosis (CF) unless serum aldosterone, plasma renin activity, and urinary electrolytes are measured and mutation analysis rules out CF. Hypo- and hyperthyroidism may alter lung function and affect the central respiratory drive. The thyroid hormone plays an essential role in lung development, surfactant synthesis, and lung defence. Complications of hypoparathyroidism are largely due to hypocalcaemia. Laryngospasm can lead to stridor and airway obstruction. Ovarian tumours, benign or malignant, may present with unilateral or bilateral pleural effusions. Metabolic storage disorders, primarily as a consequence of lysosomal dysfunction from enzymatic deficiencies, constitute a diverse group of rare conditions that can have profound effects on the respiratory system. Copyright © 2011 Elsevier Ltd. All rights reserved.

Lung Abscess: An Early Complication of Lung Transplantation in a Patient with Cystic Fibrosis.

PubMed

Markelić, I; Jakopović, M; Klepetko, W; Džubur, F; Hećimović, A; Makek, M J; Samaržija, M; Dugac, A V

2017-01-01

A 22-year-old woman with cystic fibrosis (CF) developed lung abscess, as a rare complication caused by multidrug-resistant (MDR) Acinetobacter baumannii infection, after lung transplantation (LT). After 6 months of long-term antibiotic therapy, the abscess was successfully eliminated. In reviewed published literature, no previous report was found describing this kind of complication caused by MDR A. baumannii in post-LT patient with CF. In our experience, lung abscess in LT recipients with CF can be successfully treated with prolonged antibiotic therapy.

Magnetomotive optical coherence elastography for relating lung structure and function in cystic fibrosis

NASA Astrophysics Data System (ADS)

Chhetri, Raghav K.; Carpenter, Jerome; Superfine, Richard; Randell, Scott H.; Oldenburg, Amy L.

2010-02-01

Cystic fibrosis (CF) is a genetic defect in the cystic fibrosis transmembrane conductance regulator protein and is the most common life-limiting genetic condition affecting the Caucasian population. It is an autosomal recessive, monogenic inherited disorder characterized by failure of airway host defense against bacterial infection, which results in bronchiectasis, the breakdown of airway wall extracellular matrix (ECM). In this study, we show that the in vitro models consisting of human tracheo-bronchial-epithelial (hBE) cells grown on porous supports with embedded magnetic nanoparticles (MNPs) at an air-liquid interface are suitable for long term, non-invasive assessment of ECM remodeling using magnetomotive optical coherence elastography (MMOCE). The morphology of ex vivo CF and normal lung tissues using OCT and correlative study with histology is also examined. We also demonstrate a quantitative measure of normal and CF airway elasticity using MMOCE. The improved understanding of pathologic changes in CF lung structure and function and the novel method of longitudinal in vitro ECM assessment demonstrated in this study may lead to new in vivo imaging and elastography methods to monitor disease progression and treatment in cystic fibrosis.

Assessment of Aspergillus sensitization or persistent carriage as a factor in lung function impairment in cystic fibrosis patients.

PubMed

Fillaux, Judith; Brémont, François; Murris, Marléne; Cassaing, Sophie; Rittié, Jean-Luc; Tétu, Laurent; Segonds, Christine; Abbal, Michel; Bieth, Eric; Berry, Antoine; Pipy, Bernard; Magnaval, Jean-François

2012-11-01

Cystic fibrosis (CF) patients presenting with persistent carriage of, or sensitization to, Aspergillus fumigatus are often treated with antifungal therapies because the presence of the fungus is commonly thought to impede lung function, even in the absence of allergic bronchopulmonary aspergillosis (ABPA). The aim of this study was to assess Aspergillus-related status modulating the forced expiratory volume in 1 s (FEV₁) of CF patients. From 1995 to 2007, 251 patients were evaluated. Demographic data, cystic fibrosis transmembrane conductance regulator gene (CFTR) mutations, body mass index, and FEV(1) were recorded. The presence of A. fumigatus and Pseudomonas aeruginosa in sputum and the levels of A. fumigatus precipitin, total IgE (t-IgE), and specific anti-A. fumigatus IgE (Af-IgE) were determined. Patients were divided into 3 groups: (1) ABPA: A. fumigatus precipitin ≥3 lines, Af-IgE > 0.35 IU/ml, and t-IgE ≥500 IU/ml; (2) sensitization: Af-IgE > 0.35 IU/ml but t-IgE < 500 IU/ml; and (3) persistent carriage: Af-IgE ≤ 0.35 IU/ml with either an A. fumigatus persistent positive culture or an A. fumigatus precipitin ≥3 lines, provided this serological finding had been found associated with at least 1 A. fumigatus-positive culture. The remaining patients represented the control group. A multivariate analysis was carried out with FEV(1) as the outcome variable. ABPA, sensitization, and persistent carriage were significantly associated with a larger decline in FEV₁ compared with the control group, with odds ratios of 15.9, 14.9, and 10.7, respectively. This association was independent of other associated factors (P. aeruginosa transient detection, age, being underweight, and low FEV₁ at baseline). In addition to ABPA, sensitization and persistent carriage appear to have an impact on pulmonary function in CF patients.

Role of IRE1α/XBP-1 in Cystic Fibrosis Airway Inflammation

PubMed Central

Ribeiro, Carla M. P.; Lubamba, Bob A.

2017-01-01

Cystic fibrosis (CF) pulmonary disease is characterized by chronic airway infection and inflammation. The infectious and inflamed CF airway environment impacts on the innate defense of airway epithelia and airway macrophages. The CF airway milieu induces an adaptation in these cells characterized by increased basal inflammation and a robust inflammatory response to inflammatory mediators. Recent studies have indicated that these responses depend on activation of the unfolded protein response (UPR). This review discusses the contribution of airway epithelia and airway macrophages to CF airway inflammatory responses and specifically highlights the functional importance of the UPR pathway mediated by IRE1/XBP-1 in these processes. These findings suggest that targeting the IRE1/XBP-1 UPR pathway may be a therapeutic strategy for CF airway disease. PMID:28075361

Respiratory exacerbation in a young adult with cystic fibrosis and tricuspid atresia.

PubMed

Wood, Jamie; Sawyer, Abbey; Mulrennan, Siobhain; Bullock, Andrew

2018-07-01

Tricuspid atresia (TAt) is a complex congenital heart defect (CHD) characterized by the absence of the tricuspid valve and right ventricular hypoplasia requiring surgery in childhood, the Fontan procedure. We present a case of a 21-year-old male with TAt and cystic fibrosis (CF), who underwent a Fontan procedure in childhood, presenting to an adult CF clinic with severe deterioration in his respiratory status and multi-organ dysfunction associated with CF. This report describes problems associated with the management of a CF respiratory exacerbation and extrapulmonary manifestations of CF in the unique situation of a Fontan circulation, a circulation with absence of a subpulmonary ventricle and pulsatile pulmonary arterial blood flow where maintenance of systemic cardiac output is totally dependent on good respiratory function and low pulmonary artery pressures.

Biofilm Filtrates of Pseudomonas aeruginosa Strains Isolated from Cystic Fibrosis Patients Inhibit Preformed Aspergillus fumigatus Biofilms via Apoptosis

PubMed Central

Shirazi, Fazal; Ferreira, Jose A. G.; Stevens, David A.; Clemons, Karl V.; Kontoyiannis, Dimitrios P.

2016-01-01

Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) colonize cystic fibrosis (CF) patient airways. Pa culture filtrates inhibit Af biofilms, and Pa non-CF, mucoid (Muc-CF) and nonmucoid CF (NMuc-CF) isolates form an ascending inhibitory hierarchy. We hypothesized this activity is mediated through apoptosis induction. One Af and three Pa (non-CF, Muc-CF, NMuc-CF) reference isolates were studied. Af biofilm was formed in 96 well plates for 16 h ± Pa biofilm filtrates. After 24 h, apoptosis was characterized by viability dye DiBAc, reactive oxygen species (ROS) generation, mitochondrial membrane depolarization, DNA fragmentation and metacaspase activity. Muc-CF and NMuc-CF filtrates inhibited and damaged Af biofilm (p<0.0001). Intracellular ROS levels were elevated (p<0.001) in NMuc-CF-treated Af biofilms (3.7- fold) compared to treatment with filtrates from Muc-CF- (2.5- fold) or non-CF Pa (1.7- fold). Depolarization of mitochondrial potential was greater upon exposure to NMuc-CF (2.4-fold) compared to Muc-CF (1.8-fold) or non-CF (1.25-fold) (p<0.0001) filtrates. Exposure to filtrates resulted in more DNA fragmentation in Af biofilm, compared to control, mediated by metacaspase activation. In conclusion, filtrates from CF-Pa isolates were more inhibitory against Af biofilms than from non-CF. The apoptotic effect involves mitochondrial membrane damage associated with metacaspase activation. PMID:26930399

Biofilm Filtrates of Pseudomonas aeruginosa Strains Isolated from Cystic Fibrosis Patients Inhibit Preformed Aspergillus fumigatus Biofilms via Apoptosis.

PubMed

Shirazi, Fazal; Ferreira, Jose A G; Stevens, David A; Clemons, Karl V; Kontoyiannis, Dimitrios P

2016-01-01

Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) colonize cystic fibrosis (CF) patient airways. Pa culture filtrates inhibit Af biofilms, and Pa non-CF, mucoid (Muc-CF) and nonmucoid CF (NMuc-CF) isolates form an ascending inhibitory hierarchy. We hypothesized this activity is mediated through apoptosis induction. One Af and three Pa (non-CF, Muc-CF, NMuc-CF) reference isolates were studied. Af biofilm was formed in 96 well plates for 16 h ± Pa biofilm filtrates. After 24 h, apoptosis was characterized by viability dye DiBAc, reactive oxygen species (ROS) generation, mitochondrial membrane depolarization, DNA fragmentation and metacaspase activity. Muc-CF and NMuc-CF filtrates inhibited and damaged Af biofilm (p<0.0001). Intracellular ROS levels were elevated (p<0.001) in NMuc-CF-treated Af biofilms (3.7- fold) compared to treatment with filtrates from Muc-CF- (2.5- fold) or non-CF Pa (1.7- fold). Depolarization of mitochondrial potential was greater upon exposure to NMuc-CF (2.4-fold) compared to Muc-CF (1.8-fold) or non-CF (1.25-fold) (p<0.0001) filtrates. Exposure to filtrates resulted in more DNA fragmentation in Af biofilm, compared to control, mediated by metacaspase activation. In conclusion, filtrates from CF-Pa isolates were more inhibitory against Af biofilms than from non-CF. The apoptotic effect involves mitochondrial membrane damage associated with metacaspase activation.

The top 10 research priorities in cystic fibrosis developed by a partnership between people with CF and healthcare providers

PubMed Central

Rowbotham, Nicola J; Smith, Sherie; Leighton, Paul A; Rayner, Oli C; Gathercole, Katie; Elliott, Zoe C; Nash, Edward F; Daniels, Tracey; Duff, Alistair J A; Collins, Sarah; Chandran, Suja; Peaple, Ursula; Brownlee, Keith

2018-01-01

There remain many treatment uncertainties in cystic fibrosis (CF). With limited resources, research should focus on questions which are most important to the CF community. We conducted a James Lind Alliance Priority Setting Partnership in CF. Research questions were elicited and then prioritised in successive surveys. A workshop agreed the final top 10. Online methods avoided cross infection and widened participation. The elicitation survey had 482 respondents (1080 questions) and prioritisation survey 677 respondents. Participants were drawn equally from the patient and clinical communities globally. We have achieved a consensus on 10 research priorities which will be attractive to funders. PMID:28778919

Effects of inhaled high-molecular weight hyaluronan in inflammatory airway disease.

PubMed

Lamas, Adelaida; Marshburn, Jamie; Stober, Vandy P; Donaldson, Scott H; Garantziotis, Stavros

2016-10-03

Cystic fibrosis (CF) is a chronic inflammatory disease that is affecting thousands of patients worldwide. Adjuvant anti-inflammatory treatment is an important component of cystic fibrosis treatment, and has shown promise in preserving lung function and prolonging life expectancy. Inhaled high molecular weight hyaluronan (HMW-HA) is reported to improve tolerability of hypertonic saline and thus increase compliance, and has been approved in some European countries for use as an adjunct to hypertonic saline treatment in cystic fibrosis. However, there are theoretical concerns that HMW-HA breakdown products may be pro-inflammatory. In this clinical pilot study we show that sputum cytokines in CF patients receiving HMW-HA are not increased, and therefore HMW-HA does not appear to adversely affect inflammatory status in CF airways.

Increased (/sup 125/I)trypsin-binding in serum from cystic fibrosis patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cox, K.L.; Frates, R.C. Jr.; Sheikholislam, B.M.

1982-01-01

The capacities of normal and cystic fibrosis (CF) sera to bind to exogenous human (/sup 125/I)trypsin were compared. Sera from eight older CF patients bound significantly more exogenous human (/sup 125/I)trypsin than did sera from eight normal subjects (p less than 0.001). Disregarding the increased trypsin-binding (TB) of CF sera, serum immunoreactive trypsinogen (SIRT) levels were not detectable in these eight older CF patients. However, when SIRT levels were corrected for TB, four CF patients had normal SIRT concentrations and four had low but detectable SIRT levels. As compared to five normal newborns' sera, serum from a newborn with CFmore » had normal TB and the SIRT levels were very high. In conclusion, increased TB in CF serum lowers results of SIRT assays. Therefore, unless SIRT levels are corrected for TB, results obtained from currently available SIRT kits may be invalid.« less

A roadmap to the brittle bones of cystic fibrosis.

PubMed

Gore, Ashwini P; Kwon, Soon Ho; Stenbit, Antine E

2010-12-16

Cystic fibrosis (CF) is an autosomal recessive disorder which despite advances in medical care continues to be a life-limiting and often fatal disease. With increase in life expectancy of the CF population, bone disease has emerged as a common complication. Unlike the osteoporosis seen in postmenopausal population, bone disease in CF begins at a young age and is associated with significant morbidity due to fractures, kyphosis, increased pain, and decreased lung function. The maintenance of bone health is essential for the CF population during their lives to prevent pain and fractures but also as they approach lung transplantation since severe bone disease can lead to exclusion from lung transplantation. Early recognition, prevention, and treatment are key to maintaining optimal bone health in CF patients and often require a multidisciplinary approach. This article will review the pathophysiology, current clinical practice guidelines, and potential future therapies for treating CF-related bone disease.

Diagnosing cystic fibrosis-related diabetes: current methods and challenges.

PubMed

Prentice, Bernadette; Hameed, Shihab; Verge, Charles F; Ooi, Chee Y; Jaffe, Adam; Widger, John

2016-07-01

Cystic fibrosis-related diabetes (CFRD) is the end-point of a spectrum of glucose abnormalities in cystic fibrosis that begins with early insulin deficiency and ultimately results in accelerated nutritional decline and loss of lung function. Current diagnostic and management regimens are unable to entirely reverse this clinical decline. This review summarises the current understanding of the pathophysiology of CFRD, the issues associated with using oral glucose tolerance tests in CF and the challenges faced in making the diagnosis of CFRD. Medline database searches were conducted using search terms "Cystic Fibrosis Related Diabetes", "Cystic Fibrosis" AND "glucose", "Cystic Fibrosis" AND "insulin", "Cystic Fibrosis" AND "Diabetes". Additionally, reference lists were studied. Expert commentary: Increasing evidence points to early glucose abnormalities being clinically relevant in cystic fibrosis and as such novel diagnostic methods such as continuous glucose monitoring or 30 minute sampled oral glucose tolerance test (OGTT) may play a key role in the future in the screening and diagnosis of early glucose abnormalities in CF.

Self-efficacy: empowering parents of children with cystic fibrosis.

PubMed

McDonald, Catherine M; Haberman, Diane; Brown, Natalie

2013-09-01

Can parent engagement in the development and delivery of educational materials for cystic fibrosis (CF) promote increased self-efficacy and confidence in self-management skills? Standard therapies for a child with CF frequently involve pulmonary treatment, medications, and behavioral and nutritional interventions. Parents report that the prescribed CF care can be overwhelming. Previous research at this pediatric CF Center indicated the parental perception of the difficulty in managing CF-related nutrition therapy. Parents' nutrition knowledge was an initial target of this continuous quality improvement (CQI) project with a long-range aim of increasing children's median body mass index (BMI) percentiles for patients at this pediatric CF center. The local CF Parent Advisory Council, CF parents and staff collaborated on this family-centered CQI project. A CF parent website with weekly email newsletters and a facebook page were developed and evolved with input from parents. Parental feedback was gathered through electronic surveys, written questionnaires, focus groups and informal interviews. A convenience sample of parents participated in pre- and post-intervention surveys to determine change in self-confidence in effectively managing their children's CF treatment regimens. Results were also compared with responses from a larger previous survey. Parental knowledge of nutrition facts and medical nutrition therapy for CF did not increase significantly over the course of the CQI project. Surveyed parents reported increased confidence in their self-management skills. Although mean BMI percentiles have increased at this center, they remain below the national average. Parent-driven educational strategies provide an opportunity to promote reliable CF-related information in parent-preferred formats that enhance self-management skills in caring for children with CF. Parental confidence to follow CF center recommendations increased between 2004 and 2011. Although many factors may impact confidence, parent satisfaction with the creation of electronic resources and engagement in the CQI process were intangible, but important outcomes. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

When Women with Cystic Fibrosis Become Mothers: Psychosocial Impact and Adjustments

PubMed Central

Duff, Alistair J. A.; Etherington, Christine

2016-01-01

Advances in the treatment and life expectancy of cystic fibrosis (CF) patients mean that motherhood is now a realistic option for many women with CF. This qualitative study explored the psychosocial impact and adjustments made when women with CF become mothers. Women with CF (n = 11) were recruited via an online forum and participated in semistructured telephone interviews about their experiences of becoming a mother. Transcriptions were analysed using Grounded Theory. Analysis revealed three core categories: (i) “Living with CF”: how becoming a mother impacted on health and treatment adherence, requiring a change in support from the CF team, (ii) “Becoming a Mother”: balancing issues common to new mothers with their CF, and (iii) “Pooling Personal Resources”: coping strategies in managing the dual demands of child and CF care. Participants experienced a variety of complex psychosocial processes. Most participants acknowledged an initial negative impact on CF care; however over time they reported successful adaptation to managing dual commitments and that adherence and motivation to stay well had improved. This study highlights the need for preconceptual psychosocial counselling and postpartum adjustment to CF care. PMID:27999682

EGFR mutation detection in circulating cell-free DNA of lung adenocarcinoma patients: analysis of LUX-Lung 3 and 6

PubMed Central

Wu, Yi-Long; Sequist, Lecia V; Hu, Cheng-Ping; Feng, Jifeng; Lu, Shun; Huang, Yunchao; Li, Wei; Hou, Mei; Schuler, Martin; Mok, Tony; Yamamoto, Nobuyuki; O'Byrne, Kenneth; Hirsh, Vera; Gibson, Neil; Massey, Dan; Kim, Miyoung; Yang, James Chih-Hsin

2017-01-01

Background: In the Phase III LUX-Lung 3/6 (LL3/LL6) trials in epidermal growth factor receptor (EGFR) mutation-positive lung adenocarcinoma patients, we evaluated feasibility of EGFR mutation detection using circulating cell-free DNA (cfDNA) and prognostic and predictive utility of cfDNA positivity (cfDNA+). Methods: Paired tumour and blood samples were prospectively collected from randomised patients. Mutations were detected using cfDNA from serum (LL3) or plasma (LL6) by a validated allele-specific quantitative real-time PCR kit. Results: EGFR mutation detection rates in cfDNA were 28.6% (serum) and 60.5% (plasma). Mutation detection in blood was associated with advanced disease characteristics, including higher performance score, number of metastatic sites and bone/liver metastases, and poorer prognosis. In patients with common EGFR mutations, afatinib improved progression-free survival vs chemotherapy in cfDNA+ (LL3: HR, 0.35; P=0.0009; LL6: HR, 0.25; P<0.0001) and cfDNA− (LL3: HR, 0.46; P<0.0001; LL6: HR, 0.12; P<0.0001) cohorts. A trend towards overall survival benefit with afatinib was observed in cfDNA+ patients. Conclusions: Plasma cfDNA is a promising alternative to biopsy for EGFR testing. Detectable mutation in blood was associated with more advanced disease and poorer prognosis. Afatinib improved outcomes in EGFR mutation-positive patients regardless of blood mutation status. PMID:28006816

Macronutrient intake in preschoolers with cystic fibrosis and the relationship between macronutrients and growth.

PubMed

Filigno, Stephanie S; Robson, Shannon M; Szczesniak, Rhonda D; Chamberlin, Leigh A; Baker, Meredith A; Sullivan, Stephanie M; Kroner, John; Powers, Scott W

2017-07-01

Adequate nutrition is essential for growth in children with cystic fibrosis (CF). The new CF Foundation Clinical Practice Guidelines bring attention to monitoring macronutrient intake as well as total energy. Dietary intake of 75 preschool children with CF and pancreatic insufficiency was examined and compared to the Clinical Practice Guidelines. Regression analyses examined relationships between macronutrient intake and growth. Approximately 45% of children met the 110% minimum recommended dietary allowance (RDA) recommendation. Children consumed 35.3% (6.1) of total daily energy intake from fat, 12.7% (1.7) from protein, and 52.0% (6.1) from carbohydrates. Percent energy from protein was associated with height growth. Many preschoolers with CF are not meeting nutrition benchmarks for total energy and fat. To optimize nutrition early, dietary monitoring with frequent individualized feedback is needed. Optimizing intake of macronutrients that promote growth, especially fat and protein, should be a primary clinical target. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Molecular epidemiology of Aspergillus collected from cystic fibrosis patients.

PubMed

Sabino, Raquel; Ferreira, Jose A G; Moss, Richard B; Valente, Joana; Veríssimo, Cristina; Carolino, Elisabete; Clemons, Karl V; Everson, Cassie; Banaei, Niaz; Penner, John; Stevens, David A

2015-07-01

Aspergillus respiratory infection is a common complication in cystic fibrosis (CF) and is associated with loss of pulmonary function and allergic disease. Fifty-three Aspergillus isolates recovered from CF patients were identified to species by Internal Transcribed Spacer Region (ITS), β-tubulin, and calmodulin sequencing. Three species complexes (Terrei, Nigri, and Fumigati) were found. Identification to species level gave a single Aspergillus terreus sensu stricto, one Aspergillus niger sensu stricto and 51 Aspergillus fumigatus sensu stricto isolates. No cryptic species were found. To our knowledge, this is the first prospective study of Aspergillus species in CF using molecular methods. The paucity of non-A. fumigatus and of cryptic species of A. fumigatus suggests a special association of A. fumigatus sensu stricto with CF airways, indicating it likely displays unique characteristics making it suitable for chronic residence in that milieu. These findings could refine an epidemiologic and therapeutic approach geared to this pathogen. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.