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Sample records for axsym anti-cyclic citrullinated

  1. Anti-cyclic citrullinated peptide antibodies in children with Juvenile Idiopathic Arthritis.

    PubMed

    Hamooda, Mohamed; Fouad, Hala; Galal, Nermeen; Sewelam, Nadia; Megahed, Dina

    2016-09-01

    The purpose of present study was to access the prevalence of anti-cyclic citrullinated peptide (anti-CCP) antibodies in children with Juvenile Idiopathic Arthritis (JIA), and to investigate the clinical significance and diagnostic value of the anti-CCP antibodies in correlation with age, sex & activity. This case-control study was performed on 50 patients with JIA in addition to 40 sex and age-matched children as a control group. The participants were recruited from rheumatology Outpatient Clinic of Cairo University Specialized Pediatric Hospital. Patients were subjected to full history taking, clinical examination, routine laboratory investigations and x-rays on involved joints. Both patients and controls underwent assay of anti-CCP antibodies by AxSYM Anti-CCP IgG Microparticle Enzyme Immunoassay (MEIA) which is a semi-quantitative determination of the IgG class of autoantibodies specific to cyclic citrullinated peptide (CCP) in patients' serum or plasma. Data were analyzed using Mann-Whitney U test, ANOVA, and independent-samples t-test by SPSS version 15. Anti-CCP positivity was identified amongst patients with JIA, particularly those JIA patients experiencing RF positive polyarticular disease onset. Above all, it is important that anti-CCP positivity and bone erosions, degree of joint damage, and ESR levels were significantly correlated. Anti-CCP could be utilized as a valuable marker in the polyarticular form of JIA to direct early, and could be aggressive therapeutic intervention.

  2. [Anti-cyclic citrullinated peptide antibodies and rheumatoid arthritis].

    PubMed

    Hayashi, Nobuhide; Kumagai, Shunichi

    2010-05-01

    Rheumatoid arthritis (RA) is a severe, progressive, systemic inflammatory disease of unknown etiology. Early diagnosis of RA is important to identify individuals who will develop severe destructive disease, so that effective treatment can be initiated before irreversible damage occurs. Rheumatoid factor (RF) has been commonly used as a serological marker for RA, although RF had a tolerable sensitivity of 75.9% for RA, but low specificity of 78.7% and 75.4% for patients with other rheumatic diseases and chronic inflammatory disease, respectively. Antibodies to citrullinated protein/peptide antigens, i.e., to peptides post-translationally modified by the conversion of arginine to cilrulline (ACPA), are specific serological markers for RA. Not only did anti-cyclic citrullinated peptide antibody (anti-CCP) demonstrate a higher sensitivity of 78.5% when compared to RF, but anti-CCP also had a much higher specificity of 95.9% and 97.9% for other rheumatic diseases and chronic inflammatory disease patients, respectively. Moreover, meta-analysis revealed that pooled sensitivity and pooled specificity were 67% and 95% for anti-CCP, 69% and 85% for RF, respectively, and that anti-CCP was more specific than RF for diagnosing RA. In 2009, ACPA (anti-CCP) was included in the new Criteria for RA from the American College of Rheumatology and the European League Against Rheumatism. Anti-CCP testing is particularly useful in the diagnosis of RA, being present early in the disease process, and able to predict severe disease and irreversible damage. In addition, the titers might be early predictors of the efficacy of anti-TNF therapy. In this review, we discuss the historical background of anti-CCP as well as its diagnostic performance, usefulness for early diagnosis, prognostic capability, and pathogenesis of RA.

  3. The role of anti-cyclic citrullinated peptide antibodies in predicting rheumatoid arthritis.

    PubMed

    Rexhepi, Sylejman; Rexhepi, Mjellma; Sahatçiu-Meka, Vjollca; Tafaj, Argjend; Izairi, Remzi; Rexhepi, Blerta

    2011-01-01

    The study presents the results of predicting role of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis, compared to rheumatoid factor. 32 patients with rheumatoid arthritis were identified from a retrospective chart review. The results of our study show that presence of the rheumatoid factor has less diagnostic and prognostic significance than the anti-cyclic citrullinated peptide, and suggests its superiority in predicting an erosive disease course.

  4. Anti-cyclic citrullinated peptide antibody in systemic sclerosis.

    PubMed

    Morita, Y; Muro, Y; Sugiura, K; Tomita, Y

    2008-01-01

    To determine if anti-cyclic citrullinated peptide (anti-CCP) antibody titers can distinguish the overlap syndrome of systemic sclerosis and rheumatoid arthritis (SSc-RA) in patients with systemic sclerosis (SSc) and to investigate the clinical significance of anti-CCP antibodies in SSc. Serum levels of anti-CCP antibodies were measured by enzyme-linked immunosorbent assay in 159 outpatients: 114 with SSc, 14 with rheumatoid arthritis, 7 with SSc-RA overlap syndrome, and 24 with Sjögren's syndrome. In patients with SSc and SSc-RA, we also measured serum levels of matrix metalloproteinase-3 and anti-agalactosyl IgG antibody. Elevated serum levels of anti-CCP antibodies were observed in 3 of 114 patients (2.6%) with SSc, 9 of 14 patients (64%) with RA, 6 of 7 patients (86%) with SSc-RA, and only 1 of 24 patients (4.2%) with SjS. In patients with SSc-RA, serum anti-CCP antibody levels were significantly higher than those seen in SSc (p<0.001). The sensitivity, specificity, and predictive values of elevated anti-CCP titers for SSc-RA were higher than either matrix metalloproteinase-3 and anti-agalactosyl IgG antibodies as markers. In addition, almost all SSc-RA and SSc patients with elevated serum levels of anti-CCP antibodies exhibited arthralgias and interstitial pneumonia. Anti-CCP antibody titers are a reliable marker of SSc-RA facilitating its distinction from SSc alone.

  5. Anti-cyclic citrullinated peptide antibodies in patients with sarcoidosis.

    PubMed

    Kobak, Senol; Ylmaz, H; Sever, F; Duran, A; Sen, N

    2014-10-20

    Anti-cyclic citrullinated peptide (anti-CCP) antibodies have a high predictive value in rheumatoid arthritis (RA) patients and are associated with disease severity. Sarcoidosis is a chronic inflammatory disease characterized by non-calcified granuloma formations. To determining the prevalence of anti-CCP antibodies in patients with sarcoidosis, and identifying a possible correlation with clinical and laboratory findings. Forty-two patients presenting to the rheumatology polyclinic and diagnosed with sarcoidosis as a result of the examinations made, 45 RA patients and 45 healthy subjects were included in the study. Demographic, clinical, serological and radiological data of all patients were recorded. Anti-CCP antibodies were evaluated by using a second-generation ELISA method. Rheumatoid factor (RF) IgM was determined with the nephelometry method. Forty-two patients (10 males) were included in the study. Mean patient age was 45.2 years (20-70 years) and mean duration of disease was 3.5 years. Two sarcoidosis patients (4.7%) and 38(84.4%) RA patients were found to be positive for anti-CCP antibodies while the antibody wasn't detected in any healthy subject. The two sarcoidosis patients found positive for anti-CCP were also diagnosed with rheumatoid arthritis. RF positivity was detected in 7 sarcoidosis patients (16.6%) and in only one subject in the control group. The prevalence of anti-CCP antibodies in patients with sarcoidosis was found to be significantly lower than RA patients and similar with the healthy control group. This result shows that anti-CCP antibodies don't have an important role in the pathogenesis of sarcoidosis, but could be important in revealing the overlap syndromes of sarcoidosis-RA.

  6. Anti-cyclic citrullinated peptide (anti-CCP) antibodies with brucellosis.

    PubMed

    Kisacik, Bunyamin; Dag, Muhammet Said; Pehlivan, Yavuz; Ugurlu, Kenan; Mercan, Ozge Kaya; Aydinli, Musa; Devay, Seda Duygulu; Sayarlioglu, Mehmet; Onat, Ahmet Mesut

    2014-06-01

    Anti-cyclic citrullinated peptide (anti-CCP) was positive in 11.5 % and rheumatoid factor was positive in 8.8 % of the patients with Brucella. After a comparative evaluation, we have found out that there was not a statistical significance concerning the anti-CCP levels between the patients with brucellosis and healthy control.

  7. Anti-cyclic citrullinated peptide positivity in non-rheumatoid arthritis disease samples: citrulline-dependent or not?

    PubMed

    Vannini, A; Cheung, K; Fusconi, M; Stammen-Vogelzangs, J; Drenth, J P H; Dall'Aglio, A C; Bianchi, F B; Bakker-Jonges, L E; van Venrooij, W J; Pruijn, G J M; Zendman, A J W

    2007-04-01

    Antibodies directed against citrullinated proteins (eg anti-cyclic citrullinated peptide (CCP)) have excellent diagnostic and good prognostic potential for rheumatoid arthritis. Type 1 autoimmune hepatitis (AIH-1) is a chronic liver disease characterised by a variety of serum autoantibodies. Recently, in a large group of patients with AIH-1 without clear rheumatoid arthritis overlap, a relatively high percentage (9%) of anti-CCP2 positivity was scored. To characterise the citrulline-dependence of the observed anti-CCP2 positivity in AIH-1 sera as well as in other groups of patients without rheumatoid arthritis (mainly rheumatic diseases). Serum samples of 57 patients with AIH-1 and 66 patients without rheumatoid arthritis, most of them reported as anti-CCP positive, were tested for citrulline-specific reactivity with a second generation anti-CCP kit, with the citrullinated and the corresponding non-citrullinated (arginine-containing) antigen. A subset of AIH-1 sera was also tested with a CCP1 ELISA (and arginine control). The anti-CCP2 reactivity of most non-rheumatoid arthritis rheumatic diseases samples (87-93%) was citrulline-specific, whereas a relatively high percentage of AIH-1 samples (42-50%) turned out to be reactive in a citrulline-independent manner. The use of citrullinated and non-citrullinated CCP1 peptides confirmed a high occurrence of citrulline-independent reactivity in AIH-1 samples. In rheumatoid arthritis and most non-rheumatoid arthritis rheumatologic disease sera, anti-CCP positivity is citrulline-dependent. However in some patients, particularly patients with AIH-1, citrulline-independent reactivity in the anti-CCP2 test can occur. A positive CCP test in a non-rheumatic disease (eg liver disease) should therefore be interpreted with care, and preferably followed by a control ELISA with a non-citrullinated antigen.

  8. Anti-cyclic citrullinated peptide antibodies in scleroderma patients.

    PubMed

    Polimeni, M; Feniman, D; Skare, T S; Nisihara, Renato M

    2012-05-01

    Anti-CCP (cyclic citrullinated peptide) is considered the most useful laboratory tool in the diagnosis of rheumatoid arthritis (RA). Some authors have also found this autoantibody in patients with scleroderma (SSc). The study aimed to investigate the prevalence of anti-CCP antibodies in SSc patients from Southern Brazil and their association with clinical and serological profile of the disease. We studied 76 patients with SSc and 100 healthy volunteers for presence of anti-CCP. SSc patients charts were reviewed for clinical and laboratory data. In the SSc group, the diffuse form was present in 20.5%; 62.8% had the limited form; 14.1% had overlap with systemic lupus or polymyositis and 2.5% had SSc sine scleroderma. Anti-CCP was found in nine of 78 (11.5%) SSc patients and in one of 100 healthy volunteers (p = 0.0054). No relationship was found with arthritis, skin Rodnan m score, esophageal dysmotility, myocarditis, pulmonary hypertension and lung fibrosis. Positive association was observed with arthralgias (p = 0.02). Also, no relationship was noted with the presence of anti-centromere antibodies, anti-Scl-70, anti-RNP or rheumatoid factor. Anti-CCP are more common in SSc patients than in controls. Arthralgias but not arthritis or rheumatoid factor are more frequent in anti-CCP positive patients.

  9. Felty's syndrome and hypofibrinogenemia: an unusual target for anti-cyclic citrullinated peptide antibodies?

    PubMed

    Lazarou, Ilias; Petitpierre, Nicolas; Auger, Isabelle; Reber, Guido; Roux-Lombard, Pascale; Boehlen, Françoise; Villard, Jean

    2015-09-01

    Rheumatoid arthritis (RA) is a risk factor for the development of Felty's syndrome and large granular lymphocyte (LGL) leukemia. Anti-cyclic citrullinated peptide (CCP) antibodies are considered highly specific for RA and are directed against various citrullinated antigens, including citrullinated fibrinogen. Anti-CCP antibodies may interfere with the detection of citrullinated proteins and their function. In this article, we describe the possible inhibition of fibrinogen by anti-CCP antibodies with clinical consequences which have never been reported in the literature to our best knowledge. We present the case of a 79-year-old Caucasian woman with a longstanding history of untreated seropositive RA and who had been investigated for severe neutropenia since several months. The association of splenomegaly led to suspicion of Felty's syndrome. Flux cytometry was compatible with T-cell LGL leukemia. In addition, severe hypofibrinogenemia was detected. The later finding has not been consistently associated with the former clinical entities. Further investigations demonstrated that the anti-CCP antibodies of the patient also recognized the P41 peptide of citrullinated fibrinogen. The patient deceased of intracranial hemorrhage. It is likely, yet not definite, that high anti-citrullinated fibrinogen titers may contribute to low fibrinogen levels and could have contributed to the fatal hemorrhagic event.

  10. Anti-cyclic citrullinated peptide antibodies and rheumatoid factor sera titers in leprosy patients from Mexico.

    PubMed

    Zavala-Cerna, María G; Fafutis-Morris, Mary; Guillen-Vargas, Cecilia; Salazar-Páramo, Mario; García-Cruz, Diana E; Riebeling, Carlos; Nava, Arnulfo

    2012-11-01

    Leprosy offers a broad spectrum of altered immunological sceneries, ranging from strong cell-mediated immune responses seen in tuberculoid leprosy (TT), through borderline leprosy (BB), to the virtual absence of T cell responses characteristic in lepromatous leprosy (LL). The exact mechanism of autoantibodies production remains unknown in leprosy and other chronic inflammatory diseases and also the contribution of these antibodies to the pathogenesis of the disease. The aim of this study is to evaluate the frequency and profiles of serum anti-cyclic citrullinated peptide antibodies (a-CCP), rheumatoid factor (RF) and its relationship with leprosy spectrum. Serum samples from 67 leprosy patients (54 LL, 5 TT and 8 BB) and 46 clinically healthy subjects (CHS) from the same endemic region were investigated. The clinical chart and questionnaire were used to obtain clinical information. Anti-cyclic citrullinated peptide antibodies (a-CCP) were measured by enzyme-linked immunosorbent assay, whereas the rheumatoid factor (RF) levels were measured by nephelometric method. The mean age of patients was 51.5 ± 13 years. Sera levels of a-CCP where higher in leprosy patients than in CHS (5.9 ± 11.6 vs. 0.3 ± 0.29) (P < 0.0001); the same pattern was found for RF sera titers without reaching statistical significance (16.8 ± 22.5 vs. 9.9 ± 3) (P = NS). We did not find a correlation between a-CCP and RF Rho =0.02786 (IC 95%) P = 0.8229. However, LL patients had higher a-CCP and RF levels than TT patients. Although an absence in correlation was observed, the serum levels of a-CCP antibodies and RF appeared to be useful in distinguishing LL from TT patients with a limited significance in detecting reactional leprosy patients.

  11. Anti-Cyclic Citrullinated Peptide Antibody: An Early Diagnostic and Prognostic Biomarker of Rheumatoid Arthritis

    PubMed Central

    Manivelavan, D.; C.K., Vijayasamundeeswari

    2012-01-01

    Objectives To evaluate the role of Anti-Cyclic Citrullinated Peptide (anti-CCP) antibody and Rheumatoid Factor (RF) in Rheumatoid Arthritis (RA) patients. Methods The present study comprised of 60 clinically diagnosed rheumatoid arthritis patients and 30 apparently healthy subjects as controls. Among 60 RA patients, 30 were <2 years duration and 30 were 3 to 15 years duration. Anti-CCP and RF levels were analyed by ELISA and immunoturbidimetric assay respectively. Disease activity was assessed by disease duration, duration of morning stiffness, hand deformity and radiological findings. Anti-CCP and rheumatoid factor were measured. Result A valid comparison showed that autoantibodies directed to citrullinated antigen–anti-CCP are superior to RF for the detection of RA. Anti-CCP antibodies have an independent role in predicting radiological damage and progression in RA patients. Conclusion With their excellent specificity, anti-CCP antibodies can be used as serological marker in establishing the diagnosis of RA. Anti-CCP antibodies discriminated accurately between erosive and nonerosive RA making them a potentially good prognostic marker for the disease. PMID:23205355

  12. The role of anti-cyclic citrullinated peptide antibody in periodontal disease.

    PubMed

    Ballini, A; Tetè, S; Scattarella, A; Cantore, S; Mastrangelo, F; Papa, F; Nardi, G M; Perillo, L; Crincoli, V; Gherlone, E; Grassi, F R

    2010-01-01

    The anti-Cyclic Citrullinated Peptide Antibodies (anti-CCP) are produced locally in the inflamed synovium of Rheumatoid arthritis (RA) patients, suggesting that citrullinated proteins are located in the inflamed synovium. In scientific literature were find periodontal bacterial DNA in serum and synovial fluid of RA with PD patients. RA and adult periodontitis share common pathogenetic mechanisms and immunologic and pathological findings RA. One oral pathogen strongly implicated in the pathogenesis of periodontal disease (PD), Porphyromonas. gingivalis, possesses a unique microbial enzyme, peptidylarginine deiminase (PAD), the human equivalent of which has been identified as a susceptibility factor for RA. Under this point of view, we speculate about the presence of anti-CCP antibodies in sera of PD with RA patients. We conducted this study to evaluate and compare the diagnostic and predictive utility of anti-CCP antibodies in patients with PD and patients with PD and RA. Anti-CCP antibody was not found in 21 sera (U/ml<10), included RA controls, while only 1 patient with chronic PD and probing depth of 7,1 mm was identified positive for anti-CCP (22.2 U/ml). Our data do not support a role for anti-CCP in diagnoses of periodontal disease.

  13. Anti-cyclic citrullinated Peptide antibody: an early diagnostic and prognostic biomarker of rheumatoid arthritis.

    PubMed

    Manivelavan, D; C K, Vijayasamundeeswari

    2012-10-01

    To evaluate the role of Anti-Cyclic Citrullinated Peptide (anti-CCP) antibody and Rheumatoid Factor (RF) in Rheumatoid Arthritis (RA) patients. The present study comprised of 60 clinically diagnosed rheumatoid arthritis patients and 30 apparently healthy subjects as controls. Among 60 RA patients, 30 were <2 years duration and 30 were 3 to 15 years duration. Anti-CCP and RF levels were analyed by ELISA and immunoturbidimetric assay respectively. Disease activity was assessed by disease duration, duration of morning stiffness, hand deformity and radiological findings. Anti-CCP and rheumatoid factor were measured. A valid comparison showed that autoantibodies directed to citrullinated antigen-anti-CCP are superior to RF for the detection of RA. Anti-CCP antibodies have an independent role in predicting radiological damage and progression in RA patients. With their excellent specificity, anti-CCP antibodies can be used as serological marker in establishing the diagnosis of RA. Anti-CCP antibodies discriminated accurately between erosive and nonerosive RA making them a potentially good prognostic marker for the disease.

  14. Antibodies to mutated citrullinated vimentin and anti-cyclic citrullinated peptide antibodies in inflammatory bowel disease and related arthritis.

    PubMed

    Al-Jarallah, Khaled; Shehab, Diaa; Al-Attiyah, Rajaa; Al-Azmi, Waleed; Al-Fadli, Ahmad; Zafar Haider, Mohammed; Panaccione, Remo; Ghosh, Subrata

    2012-09-01

    Antibodies that react with citrullinated proteins (anti-mutated citrullinated vimentin [anti-MCV] and second-generation anti-cyclic citrullinated peptide antibodies [anti-CCP2]) are markers for rheumatoid arthritis. Recent studies have demonstrated that these antibodies are present in other arthropathies including the spondyloarthritis, psoriatic arthritis, and juvenile idiopathic arthritis. Arthritis associated with inflammatory bowel disease (IBD) takes various forms, with some shared similarities with classic spondylarthropathies. Our objective was to investigate the role of anti-MCV and anti-CCP2 as potential biomarkers in IBD and related arthritis. In all, 125 IBD patients (71 males, 54 females) were compared to 81 age- and sex-matched healthy controls. Anti-MCV and Anti-CCP2 IgG were measured using an enzyme linked immunosorbent assay. In the 125 IBD patients (mean age 32.6 ± 12.3 years), 44 (35.2%) had ulcerative colitis and 81 (64.8%) had Crohn's disease. Forty-four (35.2%) IBD patients developed arthritic manifestations. Antibody positivity was observed in 24/125 (19.2%) IBD patients and in 18/81 (22.2%) healthy subjects. The proportion of anti-MCV positivity among IBD patients and healthy individuals were similar: 16.8% vs. 16.0%, P = 0.887. Anti-CCP2 positivity among IBD patients and healthy individuals was also comparable: 6.4% vs. 6.2%, P = 0.948. Similarly, the presence of anti-MCV and anti-CCP2 antibodies was not different among IBD patients with and without arthritis. The mean titers of antibodies were low: anti-MCV (29.6 ± 7.5 U/mL) and anti-CCP2 (27.6 ± 4.0 U/mL) in IBD patients with arthritis. Autoantibodies to citrullinated proteins were low in IBD-related arthritis. These findings suggest that these antibodies are not useful biomarkers in IBD to predict who may develop IBD-related arthropathy. Copyright © 2011 Crohn's & Colitis Foundation of America, Inc.

  15. Detection of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis patients undergoing total knee arthroplasty.

    PubMed

    Guo, Chong-Jun; Lv, Jin-Han; Niu, Dong-Sheng; Ma, Tao; Sun, Shou-Xuan; Li, Li-Xin; Zhao, Xin; Wu, Long; Jin, Qun-Hua

    2015-01-01

    Rheumatoid arthritis (RA) is the most common chronic inflammatory joint disorder and anti-cyclic citrullinated peptide antibody (anti-CCP Ab) is regarded as a serological marker for diagnosing early and late RA. In the present study, we aimed to determine the levels of anti-CCP Ab in serum, synovial tissue (ST) and synovial fluid (SF) in RA patients undergoing total knee arthroplasty (TKA). 23 patients were included. Rheumatoid factor (RF) and anti-CCP Ab in serum were detected prior to surgery and then at 1, 3, 6 and 12 months after TKA. Synovial samples were obtained by knee arthroscopy and used for anti-CCP detection. One month after TKA, anti-CCP levels were significantly reduced (P < 0.01) in RA patients. However, their levels were not significantly different between pre-surgery and 1 year post-surgery (P > 0.05). Furthermore, anti-CCP levels in ST were much higher than in serum. These findings suggest that RA patients should continue antirheumatic therapy after TKA. ST is the preferred place for the synthesis of anti-CCP Ab.

  16. Determination of anti-cyclic citrullinated peptide antibodies in the sera of patients with liver diseases.

    PubMed

    Koga, T; Migita, K; Miyashita, T; Maeda, Y; Nakamura, M; Abiru, S; Myoji, M; Komori, A; Yano, K; Yatsuhashi, H; Eguchi, K; Ishibashi, H

    2008-01-01

    To determine the frequency of anti-cyclic citrullinated peptide (anti-CCP) antibodies in patients with HCV infection, primary biliary cirrhosis (PBC) and type-I autoimmune hepatitis (AIH) to assess the specificity of anti-CCP antibodies. Rheumatoid factor (RF) and anti-CCP antibodies were measured in the sera from patients with HCV infection (n=45), PBC (n=73), AIH (n=55) and rheumatoid arthritis (n=48), and also from the sera of healthy subjects (n=23). Anti-CCP antibodies were measured using a second generation enzyme-linked immunosorbent assay (ELISA). No sera with elevated anti-CCP were found in the patients with HCV infection. Two PBC patients (2.7%) and six AIH patients (10.5%) had anti-CCP antibodies. The seropositivity for anti-CCP in these autoimmune disease patients was associated with a high frequency of RA association [PBC; 100% (2/2), AIH; 86.4% (5/6)]. Although anti-CCP antibodies may be present in patients with autoimmune liver diseases, almost seropositive patients had concomitant RA. As a result, the measurement of anti-CCP antibodies may therefore be helpful for accurately diagnosing RA in patients with these liver diseases.

  17. Follow-up of primary Sjogren's syndrome patients presenting positive anti-cyclic citrullinated peptides antibody.

    PubMed

    Ryu, Yang-Seon; Park, Sung-Hwan; Lee, Jennifer; Kwok, Seung-Ki; Ju, Ji-Hyeon; Kim, Ho-Youn; Jeon, Chan-Hong

    2013-06-01

    Anti-cyclic citrullinated peptide antibody (anti-CCP antibody) is very useful for the diagnosis of rheumatoid arthritis (RA) and is associated with articular erosions. The specificity of anti-CCP antibody in the diagnosis of RA has been reported to be about 95 %. Because of its higher specificity in RA, we assessed the clinical features of primary Sjogren's syndrome (pSS) who were positive for anti-CCP antibody. We assessed the clinical features of 405 pSS patients. After 60 (range 7-98) months, 23 (5.6 %) patients previously diagnosed with pSS had progressed to RA. Comparing the anti-CCP positive group with the negative group, laboratory test results for anti-CCP titer and rheumatoid factor positivity with respect to clinical outcome and progression to RA, arthralgia and arthritis were significantly different. Multivariate regression analysis also showed that anti-CCP antibody titer was independently associated with progression to RA. The odds ratio of anti-CCP positivity in terms of progression to RA was 2.5 (95 % CI 1.7-3.7). Testing for anti-CCP antibody in pSS patients with arthritis may allow for the prediction of progression to RA.

  18. Serum anti-cyclic citrullinated peptide antibodies may predict disease activity in rheumatoid arthritis.

    PubMed

    Esalatmanesh, Kamal; Jamali, Raika; Jamali, Arsia; Jamali, Bardia; Nikbakht, Mohammadreza

    2012-12-01

    To define the relationship between serum anti-cyclic citrullinated peptide antibodies (anti-CCP) and disease activity, and to construct a new disease activity index by using anti-CCP in rheumatoid arthritis (RA). One hundred and five RA patients were included. Disease activity based on DAS28-ESR and serum anti-CCP was measured. There was correlation between serum anti-CCP and DAS28-ESR. (R (2) = 0.71, P value < 0.01). New disease activity index was developed by replacing anti-CCP with ESR in DAS28-ESR. There was correlation between new model and DAS28-ESR. (R (2) = 0.91, P value < 0.01) The new composite index best cut-off values corresponding to DAS28-ESR values of 2.6, 3.2, and 5.1 were 3.21, 3.38, and 4.74, respectively. There was agreement between new model and DAS28-ESR for determination of patients in different disease activity categories. (Kappa = 0.71, P value < 0.01). The new disease activity index that applies serum anti-CCP may predict disease activity in RA.

  19. Anti-cyclic citrullinated peptide antibodies are a collection of anti-citrullinated protein antibodies and contain overlapping and non-overlapping reactivities.

    PubMed

    Ioan-Facsinay, Andreea; el-Bannoudi, Hanane; Scherer, Hans U; van der Woude, Diane; Ménard, Henri A; Lora, Maximilien; Trouw, Leendert A; Huizinga, Tom W J; Toes, Rene E M

    2011-01-01

    Anti-citrullinated protein antibodies (ACPA) and anti-cyclic citrullinated peptide (anti-CCP) antibodies are a hallmark of rheumatoid arthritis and are believed to play a role in disease pathogenesis. These antibodies are typically detected in ELISA with citrullinated peptides (eg, CCP2) or proteins as antigens. The absolute concentration of anti-CCP antibodies in serum is unknown. Although antibodies to several citrullinated proteins can mainly be detected within anti-CCP-positive sera, it is currently unknown whether anti-CCP antibodies are in fact ACPA. Likewise, it is unknown to what extent antibody responses to different citrullinated antigens are crossreactive. An affinity purification method was established in which citrullinated antigen-specific antibodies were eluted from ELISA plates and then used for detection of other citrullinated antigens in ELISA or western blot. For additional crossreactivity studies, ELISA-based inhibition assays were performed with citrullinated or control peptides as inhibitors. The concentration of anti-CCP IgG antibodies was estimated to be at least 30 μg/ml in patients with high anti-CCP levels (>1600 μg/ml). Affinity-purified anti-CCP antibodies were able to recognise citrullinated fibrinogen (cit-fib) and citrullinated myelin basic protein (cit-MBP) on western blot. Furthermore, antibodies specific for cit-fib and cit-MBP were crossreactive. However, additional crossreactivity studies indicated that non-overlapping antibody responses to citrullinated peptides can also exist in patients. This report shows for the first time that anti-CCP antibodies recognise multiple citrullinated proteins and are thus a collection of ACPA. More importantly, the data indicate that different ACPA responses are crossreactive, but that crossreactivity is not complete, as distinct non-crossreactive responses can also be detected in patients with RA.

  20. Anti-cyclic citrullinated peptides positivity rate in patients with familial Mediterranean fever.

    PubMed

    Ceri, Mevlut; Unverdi, Selman; Altay, Mustafa; Ureten, Kemal; Oztürk, M Akif; Gönen, Namik; Duranay, Murat

    2010-01-01

    To investigate the prevalence and levels of anti-cyclic citrullinated peptide antibodies (anti-CCP) in patients with familial Mediterranean fever (FMF) with and without arthritis. Eighty-three patients with FMF and 43 healthy controls were included in the study. Thirty seven FMF patients had a history of arthritis, and 46 patients did not. Serum antibodies directed to the anti-CCP were assessed with a commercial enzyme-linked immunosorbent assay (ELISA) kit. Values <20U were considered negative, between 20 and 39U low, 40-99U moderate, and >100U high positive. Positivity rate of anti-CCP in the whole FMF group (14.5%) was three-fold higher than the control group (4.7%). However, the difference failed to achieve a statistically significant level (p=0.09). Anti-CCP levels were 21±30.1 in patients with arthritis and 13.1±10.3 in the non arthritic group (p<0.05). Anti-CCP positivity rates were 10/37 (27%) in patients with arthritis and 2/46 (4.3%) in patients without arthritis (p<0.005). Five FMF patients with arthritis (13.5%) had moderate-high anti-CCP levels (>40U/ml). Anti-CCP levels were between 20-39U/ ml in 2FMF patients without arthritis and in 2 healthy controls. Anti-CCP positivity rate is higher in FMF patients with arthritis (27%) than healthy controls (4.7%) (p<0.005). Anti-CCP prevalence is higher in FMF patients with arthritis than without arthritis, and that a significant proportion of FMF patients with arthritis (13.5%) had moderate-high titers of anti-CCP. Therefore, anti-CCP antibodies may not be a reliable indicator to differentiate between FMF arthritis and rheumatoid arthritis.

  1. Diagnostic performance of anti-cyclic citrullinated peptide and rheumatoid factor in patients with rheumatoid arthritis.

    PubMed

    Chang, Pi-Yueh; Yang, Cheng-Tao; Cheng, Ching-Hui; Yu, Kuang-Hui

    2016-09-01

    To compare the diagnostic performance of rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (anti-CCP) in the diagnosis of patients with rheumatoid arthritis (RA) in Taiwan. Serum concentrations of RF and anti-CCP were measured in 246 cases, including 39 patients with RA and 207 patients with other rheumatic diseases (non-RA). The age, sex, clinical presentation, RF, anti-CCP results and the final diagnoses were recorded and analyzed. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+) and negative likelihood ratio (LR-) were calculated. Among all 246 patients, 39 (15.9%) were diagnosed with RA and 207 (84.1%) were diagnosed with other rheumatic diseases (non-RA). In the diagnosis of RA, the sensitivity, specificity, PPV, NPV, LR+ and LR- of the RF test were 67%, 79%, 37%, 93%, 3.12, and 0.42, respectively. The corresponding data for the anti-CCP test were 79%, 98%, 86%, 96%, 32.91 and 0.21, respectively. The presence of either anti-CCP or RF increased the sensitivity to 85%, and when they both were present, the specificity increased to 98%. Among the 39 RA patients, 26 (66.7%) tested positive for RF, and 31 (79.5%) tested positive for anti-CCP. RF was positive in two of eight anti-CCP-negative patients with RA, and anti-CCP was positive in seven of 13 RF-negative patients with RA. The RF and anti-CCP tests are complementary, and the co-detection of these antibodies can increase the detection rate and provide important clinical value in the diagnosis of RA. Both anti-CCP and RF positivity are useful for the diagnosis of RA, and use of both tests together improves the diagnostic sensitivity. © 2015 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  2. Anti-Cyclic Citrullinated Peptide, Rheumatoid Factor, and Ocular Symptoms Typical of Rheumatoid Arthritis

    PubMed Central

    Itty, Sujit; Pulido, Jose S.; Bakri, Sophie J.; Baratz, Keith H.; Matteson, Eric L.; Hodge, David O.

    2008-01-01

    Purpose To correlate the presence of anti-cyclic citrullinated peptide (anti-CCP) antibodies and rheumatoid factor (RF) with ocular symptoms typical of rheumatoid arthritis (RA). Methods The records of 451 patients who had been examined by an ophthalmologist and tested for anti-CCP antibodies over a 3-year period at the Mayo Clinic were reviewed. Records of 255 patients with titers of anti-CCP and RF were analyzed for ocular surface and inflammatory disease associated with ocular RA. Results Of the 33 anti-CCP+/RF+ patients, all were diagnosed with RA; ocular surface disease was present in 11 (33%) and inflammatory disease in 7 (21%). Of the 17 anti-CCP–/RF+ patients, 4 were diagnosed with an unspecified inflammatory arthritis and 1 with rheumatoid arthritis; a separate 5 (29%) had ocular surface disease. Out of 5 anti-CCP+/RF– patients, 3 were diagnosed with RA but none had ocular symptoms. Out of 200 anti-CCP–/RF– patients, 32 (16%) had ocular surface disease and 2 (1%) had ocular inflammation. Of the 74 patients diagnosed with any form of inflammatory arthritis, anti-CCP+/RF+ patients had more and worse inflammatory ocular RA disease compared to the other groups. Conclusions Patients who were both anti-CCP and RF positive tended to have more and worse ocular disease. In patients diagnosed with an inflammatory arthritis, the presence of anti-CCP antibodies and RF provides useful information to ophthalmologists for identifying patients most at risk for inflammatory ocular disease. PMID:19277223

  3. The significance of rheumatoid factor and anti-cyclic citrullinated peptide antibodies in systemic lupus erythematosus.

    PubMed

    Popescu, C; Zofotă, Sabina; Bojincă, Violeta; Ionescu, Ruxandra

    2013-01-01

    Systemic lupus erythematosus (SLE) resembles rheumatoid arthritis (RA) in at least two areas: it involves joints (arthritis) and it can lead to rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP) positivity, both with a lower prevalence than in RA. The present study aimed to quantify the prevalence of RF and anti-CCP antibodies in a SLE group, to note their possible correlations with clinical and laboratory variables. The study analyzed 45 SLE patients, 139 RA patients and 147 normal subjects by measuring RF and anti-CCP2 titers and comparing/correlating inter-groups or subgroups divided by criteria such as arthritis and RF/anti-CCP positivity. In the SLE group, 6.7% (3/45) were anti-CCP positive, 15.5% (7/45) were RF positive and 4.4% (2/45) were positive for both tests. A cut-off titer of anti-CCP antibodies < 1.25 U/mL had 82.2% sensitivity and 90.6% specificity for SLE. A cut-off titer of RF antibodies < 18.5 U/mL had 84.4% sensitivity and 83.5% specificity for SLE. The arthritis SLE subgroup did not differ significantly from the non-arthritis SLE subgroup. Anti-CCP positive SLE patients with or without arthritis had a RF titer 6 times higher than anti-CCP negative SLE patients. Anti-CCP antibodies and RF are detectable in SLE with lower titers and prevalence than in RA. The SLE articular involvement does not influence the titers and positivity frequencies of RF and anti-CCP antibodies, nor does the latter associate with SLE arthritis, suggesting no pathogenic role in the development of SLE arthritis.

  4. A case of anti-cyclic citrullinated peptides antibody positive rheumatoid meningitis without arthritis at the onset of neurological symptoms.

    PubMed

    Abe, Tetsuya; Mishima, Kazuhiko; Uchino, Akira; Sasaki, Atsushi; Tanahashi, Norio; Takao, Masaki

    2016-09-29

    We report an 84-year-old woman with rheumatoid meningitis. She developed weakness in her muscles and became cognitively impaired. However, physical examination revealed no evidence of rheumatoid arthritis. Levels of anti-cyclic citrullinated peptide antibodies were elevated. Brain magnetic resonance imaging (MRI) showed hyperintense lesions in the frontotemporoparietal subarachnoid space on fluid attenuated inversion recovery (FLAIR) images. Leptomeningeal enhancement was also evident on gadolinium-enhanced T1-weighted images. We suspected rheumatoid meningitis. A brain biopsy was performed and methylprednisolone pulse therapy was started. Subsequently, her symptoms and MRI findings rapidly improved.

  5. Anti-cyclic citrullinated peptide antibody in rheumatoid arthritis: relation with disease aggressiveness.

    PubMed

    del Val del Amo, N; Ibanez Bosch, R; Fito Manteca, C; Gutierrez Polo, R; Loza Cortina, E

    2006-01-01

    To analyse the value of the anti-cyclic citrullinated peptide antibody (anti-CCP) in patients with rheumatoid arthritis (RA) as a prognostic factor, as well as its relationship with disease activity. A cross-sectional study was made on 89 patients with RA. The following values were assessed: erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-CCP, Disease Activity Score 28 (DAS 28), Modified Health Assessment Questionnaire score (M-HAQ) and simplified radiologic score of Sharp/Van der Heijde (SENS: simple erosion narrowing score). Sixty-four percent of the patients were anti-CCP positive, from which 36.8% were negative for RF. Among negative RF patients, 48.3% had anti-CCP antibody. The average value of DAS 28 in anti-CCP positive patients was 4.31 (SD 1.27) compared to 3.30 (SD 1.55) for anti-CCP negative (p 200 U/ml) had higher SENS (p < 0.05). There was no correlation between M-HAQ and anti-CCP. Prevalence of anti-CCP was higher among patients with higher activity. Patients with higher levels of anti-CCP antibody had more aggressive disease, with greater activity (elevated values in DAS 28 and CRP) and more severe radiological damage (more erosions and higher radiological damage, SENS).

  6. Performance characteristics of a new automated method for measurement of anti-cyclic citrullinated peptide.

    PubMed

    Noordegraaf, Madelon; Wolthuis, Albert; Peters, Frans; de Groot, Monique; Hoedemakers, Rein

    2015-06-01

    Rheumatoid arthritis (RA) is a chronic inflammatory auto-immune disease affecting approximately 1%-2% of the population worldwide. RA is a potentially crippling disease since it results in malformation of the joints. RA is mostly diagnosed based on clinical manifestations but serological tests against autoantibodies, such as rheumatoid factor and anti-cyclic citrullinated peptides (aCCP), are available. The presence of aCCP antibodies is strongly associated with a more severe, destructive disease course. Recently, a new test for the measurement of aCCP antibodies on the IMMULITE 2000(XPi) platform was developed by Siemens Healthcare. In this study we investigated the performance characteristics of this new aCCP test in four different hospital laboratories and compared the new test with three different commercially available platforms. Samples were collected from patients presented to the hospital for aCCP measurement. Serum aCCP levels were determined by aCCP (Ig)G assay for IMMULITE 2000(XPi) systems (Siemens Healthcare), ImmunoScan RA enzyme-linked immunosorbent assay (ELISA) test (Eurodiagnostica), Immunocap 250 (Thermofisher) or aCCP IgG assay on the Modular system (Roche Diagnostics). The evaluation protocol consisted of within-run imprecision (20 sequential runs), between-run imprecision (16 workdays), comparison of serum and plasma measurement and method comparison. The within-run imprecision (n=20) for aCCP IgG assay on three different IMMULITE 2000(XPi) systems ranged from 3.0% to 6.9% at levels 3.2-171.2 U/mL. Between-run imprecision (n=16 days) ranged from 5.2% to 11% at levels of 3.2-106.9 U/mL. Method comparison showed good correlation when samples were measured on two different Immulite analyzers in two different hospital laboratories [0.21+0.96x (n=40)]. Method comparison of the IMMULITE 2000(XPi) aCCP test with aCCP on Immunoscan RA ELISA (n=112), Immunocap 250 (n=105) and the Modular system (n=289) resulted in a concordance of 90.2%, 93.3% and 94

  7. Diagnostic value of synovial fluid anti-cyclic citrullinated peptide antibody for rheumatoid arthritis.

    PubMed

    Heidari, Behzad; Abedi, Hassan; Firouzjahi, Alireza; Heidari, Parnaz

    2010-09-01

    Early and accurate diagnosis and treatment of rheumatoid arthritis (RA) improves disease outcome. Anti-cyclic citrullinated peptide antibody (anti-CCP) which is highly specific for RA is produced locally from inflamed synovium. The present study was designed to assess the diagnostic performance of synovial fluid anti-CCP (sf-CCP) for RA. A total of 128 patients consisted of 37 RA confirmed by the American College of Rheumatology revised criteria, 91 non-RA (50 non-RA inflammatory arthritis and 41 osteoarthritis) entered the study. Serum anti-CCP (sm-CCP) and Sf-CCP were measured by the ELISA method. Receiver operating characteristics curves were constructed to determine the optimal cutoff point levels for sf-CCP and sm-CCP to discriminate RA from non-RA. Diagnostic characteristics of both variables were determined by comparison of RA patients with non-RA controls. Mean levels of sf-CCP and sm-CCP were significantly higher in RA than in non-RA (P < 0.001). Sf-CCP discriminated RA from non-RA at the optimal cutoff value of 10 U/mL with high accuracy at AUC value of 0.897 +/- 0.039, P < 0.001) sensitivity of 83.7% and specificity of 95.6%. Sm-CCP diagnosed RA at optimal cutoff level of 14.6 U/mL with respective sensitivity, specificity and AUC values of 84.8, 94.3% and 0.895 +/- 0.049, P < 0.001). Sm-CCP was strongly correlated with sf-CCP (r = 0.75, r (2) = 0.57, P < 0.0001). Two of 5 sm-CCP negative RA and 25.7% of serum rheumatoid factors negative RA were sf-CCP positive. These findings indicate that sf-CCP yields diagnostic ability as comparable as sm-CCP for RA. Respecting to local production of sf-CCP prior to disease onset, therefore sf-CCP determination may offer earlier as well as additional diagnostic information which may be more helpful in recognizing RA particularly among recent onset arthritis.

  8. Anti-cyclic citrullinated peptide antibodies and paraoxonase-1 polymorphism in rheumatoid arthritis.

    PubMed

    El-Banna, Hassan; Jiman-Fatani, Asif

    2014-11-19

    Rheumatoid arthritis (RA) is the most common chronic inflammatory joint disease, with a worldwide prevalence of 0.5% to 1%. Anti-cyclic citrullinated peptide antibody (anti-CCP-2 Ab) is a marker of choice for diagnosing early and late RA. Anti-oxidant enzymes activity decreases in RA patients. Till now, the relationship between the rheumatoid factor (RF) and anti-CCP-2 Ab, anti-oxidant activity and polymorphism of paraoxenase-1 (PON-1) 192 Q/R in patients with RA has not been investigated. In this study, we aimed to determine the serum level of RF and anti-CCP-2 Ab, PON-1 activity and 192 Q/R polymorphism and arylesterase (ARE) activity in patients with RA. Also, we studied RA markers in different genotypes of PON-1 of RA patients. A total of 120 RA patients and 90 healthy persons were subjected to full clinical examinations and routine laboratory tests. PON-1 and ARE activities were determined using an enzymatic spectrophotometric method. PON-1 192 gene polymorphism was determined using polymerase chain reaction based restriction fragment analysis. RF was measured by immunoturbidimetry method and anti-CCP-2 Ab was assayed by enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using SPSS for windows 20.0. The sensitivity and specificity of anti-CCP-2 Ab for the diagnosis of RA were 76.2% and 100% respectively. PON-1 and ARE activities were statistically lower (P <0.001) in the RA group compared to the control group. A negative correlation between RF and anti-CCP-2 Ab levels and PON-1 and ARE activities was found. No significant difference in the genotype distribution between RA patients and healthy persons was detected. RF and anti-CCP-2 Ab levels were higher in RA patients carried RR genotype than in those carried QQ genotype. High RF and anti-CCP-2 antibody serum levels were found to be associated with decreased PON-1 and ARE activities with no correlation between PON-1 polymorphism and serum levels of RF and anti-CCP-2 Ab in patients

  9. Value of anti-modified citrullinated vimentin and third-generation anti-cyclic citrullinated peptide compared with second-generation anti-cyclic citrullinated peptide and rheumatoid factor in predicting disease outcome in undifferentiated arthritis and rheumatoid arthritis.

    PubMed

    van der Linden, Michael P M; van der Woude, Diane; Ioan-Facsinay, Andreea; Levarht, E W Nivine; Stoeken-Rijsbergen, Gerrie; Huizinga, Tom W J; Toes, René E M; van der Helm-van Mil, Annette H M

    2009-08-01

    Autoantibodies such as rheumatoid factor (RF) and anti-citrullinated protein autoantibodies (ACPAs) determined by testing with second-generation anti-cyclic citrullinated peptide (anti-CCP-2) are frequently measured in clinical practice because of their association with disease outcome in undifferentiated arthritis (UA) and rheumatoid arthritis (RA). Recently, 2 new ACPA tests were developed: third-generation anti-CCP (anti-CCP-3) and anti-modified citrullinated vimentin (anti-MCV) autoantibody tests. To facilitate the decision on which autoantibody to test in daily practice, this study evaluated the capability of these autoantibodies and combinations of them to predict 3 outcome measures: progression from UA to RA, the rate of joint destruction in RA, and the chance of achieving sustained disease-modifying antirheumatic drug (DMARD)-free remission in RA. Patients with UA (n=625) were studied for whether UA progressed to RA after 1 year. Patients with RA (n=687) were studied for whether sustained DMARD-free remission was achieved and for the rate of joint destruction during a median followup of 5 years. Positive predictive values (PPVs) for RA development and for associations with the disease course in RA were compared between single tests (anti-CCP-2, anti-CCP-3, anti-MCV, and RF) and between combinations of these tests. Among the single tests performed in patients with UA, anti-CCP-2 tended to have the highest PPV for RA development (67.1%), but the 95% confidence intervals of the other tests overlapped. Among the single tests in patients with RA, all 4 tests showed comparable associations with the rate of joint destruction and with the achievement of remission. In both ACPA-positive and ACPA-negative RA, the presence of RF was not associated with more joint destruction. For all outcome measures, performing combinations of 2 or 3 autoantibody tests did not increase the predictive accuracy compared with performing a single test. For clinical practice, a single

  10. Early diagnostic and prognostic values of anti-cyclic citrullinated peptide antibody and cartilage oligomeric matrix protein in rheumatoid arthritis.

    PubMed

    Algergawy, Shereen A; Abd El-Sabour, M; Osman, Ahmed S; Emam, Sherin M; Elham, N

    2013-01-01

    This study aimed to evaluate the role of Anti-Cyclic Citrullinated Peptide (anti-CCP) antibody in comparison to Cartilage oligomeric matrix protein (COMP) in Rheumatoid Arthritis (RA) patients as predictors of the disease activity and cartilage destruction. The study included 60 patients &10 apparently healthy subjects. They were divided into 4 groups. Group 1: consisted of 20 patients with established rheumatoid arthritis( and positive rheumatoid factor). Group 2: 20 suspected (rheumatoid factor negative) patients Group 3: 20 patients with other autoimmune inflammatory diseases (15 with psoaritic arthritis, 5 with systemic lupus erthromatosis).and Group 4: 10 age and sex matched controls. For each patient medical examination and disease activity evaluation using Disease Activity Score (DAS) was performed Anti cyclic citrullinated peptide (anti CCP) level was measured by ELISA method and cartilage oligomeric matrix protein (COMP) was determined by indirect immune fluorescent method. Serum level of anti CCP antibodies and COMP were Significantly related to DAS (disease activity score) and cartilage destruction, the serum presence of COMP was highly significant in rheumatoid arthritis patients than those with other autoimmune disease, the sensitivity of anti CCP in diagnosis of RA was 77.5% and specificity was96.6%. It is concluded that anti CCP, and COMP may be a useful noninvasive markers for disease activity and cartilage destruction.

  11. The amount of citrullinated proteins in synovial tissue is related to serum anti-cyclic citrullinated peptide (anti-CCP) antibody levels.

    PubMed

    Olivares-Martínez, Elizabeth; Hernández-Ramírez, Diego F; Núñez-Álvarez, Carlos A; Cabral, Antonio R; Llorente, Luis

    2016-01-01

    The objective of this study was to determine the relationship between citrullinated proteins in synovial tissue with peripheral anti-citrullinated peptides autoantibodies (ACPA) and peptidylarginine deiminase (PADI) PADI2, PADI3, and PADI4 messenger RNA (mRNA) expressions in synovial tissue and fibroblast-like synoviocytes in rheumatoid arthritis (RA) patients. Eleven RA and 12 osteoarthritis (OA) patients who underwent knee replacement surgery were studied. We detected citrullinated proteins in synovial tissue homogenates by western blot and serum ACPA by ELISA to anti-cyclic citrullinated peptide (anti-CCP) antibodies, and PADI2, PADI3, and PADI4 mRNA expressions in synovial tissue and in fibroblast-like synoviocytes. Patients with high amount of citrullinated proteins in synovial tissue (3 out of 7) have high levels of anti-CCP in serum. However, in the remaining 4 patients, the amount of synovial citrullinated proteins was minimal and their sera showed low levels of anti-CCP antibodies. Furthermore, we observed an increase in PADI2 mRNA expression in RA synovial tissue compared with OA patients (p = 0.02). We detected PADI3 mRNA in the synovial tissue of RA patients, but not in the tissue of OA patients. Even though fibroblast-type synoviocytes in RA are not the main source of PADs in the synovial tissue, they express PADI2 mRNA moderately, PADI4 mRNA weakly, while there is no detectable expression of PADI3 mRNA. In conclusion, we found a variety of citrullinated proteins in the synovial tissue of RA patients and the amount of such proteins is related to serum concentration of anti-CCP antibodies. We identified the presence of PADI3 mRNA expression in synovial tissue and PADI2 and PADI4 mRNA expressions in fibroblast-like synoviocytes from patients with RA.

  12. The value of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis: do they imply new risk factors?

    PubMed

    López-Longo, Francisco Javier; Sánchez-Ramón, Silvia; Carreño, Luis

    2009-11-01

    Rheumatoid arthritis (RA) is a systemic autoimmune disease that causes chronic inflammation of the joints and several extra-articular manifestations that account for increased morbimortality of these patients. The involvement of B cells in RA pathophysiology was recognized early, with the discovery of rheumatoid factor antibody. Recently, a number of autoantibodies against citrullinated proteins have been described, of which anti-cyclic citrullinated peptide (anti-CCP) is the most specific for RA. A cohort of 937 patients with RA was studied to determine the clinical correlates of anti-CCP antibodies. The presence of anti-CCP antibodies correlated with worse joint involvement and several extra-articular manifestations, i.e., higher incidence of ischemic heart disease independent of classic cardiovascular factors and higher mortality rate. A multivariate logistic regression model showed that only anti-CCP antibodies were independently associated with the development of ischemic heart disease in patients with RA. The clinical value of anti-citrullinated protein antibodies and the relevance of anti-CCP antibodies in daily clinical practice are reviewed. Copyright 2009 Prous Science, S.A.U. or its licensors. All rights reserved.

  13. Development of synthetic anti-cyclic citrullinated peptide antibody and its arthritogenic role

    PubMed Central

    Kim, Youngkyun; Lee, Jennifer; Jung, Hyerin; Yi, Hyoju; Rim, Yeri Alice; Jung, Seung Min; Ju, Ji Hyeon

    2015-01-01

    This study was undertaken to develop a novel anti-citrullinated peptide antibody (ACPA) and to investigate its arthritogenicity in a collagen-induced arthritis (CIA) model. The novel ACPA, 12G1, was developed by injecting cyclic citrullinated antigen in mice and subsequently hybridizing the B cells producing citrullinated peptide-specific antibodies with a myeloma cell line. The arthritic joints of mice with CIA and collagen antibody-induced arthritis (CAIA) as well as interleukin-1 receptor antagonist (IL-1Ra) knockout (KO) mice were stained immunohistochemically using the 12G1 antibody. Confocal immunostaining was used to identify colocalization of 12G1 with various citrullinated proteins. 12G1 in the presence or absence of chelating beads was administered to CIA mice on days 21 and 28 after type II collagen (CII) immunization to investigate 12G1 arthritogenecity. 12G1 detected citrullinated proteins in the arthritic joints of all the experimental arthritis models used. Confocal immunostaining showed that 12G1 was colocalized with well-known citrullinated proteins, including vimentin, collagen, anti-immunoglobulin binding protein and fibronectin. Staining of citrullinated proteins using 12G1 was more diffuse in CIA mice compared with CAIA and IL-1Ra KO mice. 12G1 injection apparently acted as a booster of immunization in CIA mice in combination with a single CII immunization, with this effect being abolished when 12G1 was injected with chelating beads. The novel ACPA, 12G1, identified various citrullinated proteins in the arthritic joints of three experimental arthritis models. 12G1-treated mice developed arthritis following a single CII immunization, suggesting an arthritogenic potential for ACPA in CIA mice. PMID:26682058

  14. The anti-cyclic citrullinated peptide response in tuberculosis patients is not citrulline-dependent and sensitive to treatment.

    PubMed

    Elkayam, Ori; Segal, Refael; Bendayan, Daniele; van Uitert, Robert; Onnekink, Carla; Pruijn, Ger Jm

    2010-01-01

    Patients with tuberculosis (TB) frequently produce anti-citrullinated protein antibodies (ACPA). The objective of this study is to characterize the citrulline-dependence of the ACPA reactivity in sera of patients with mycobacterium infections. Serum samples of 134 patients with untreated mycobacterium infections (122 TB, 12 nontuberculous mycobacterium) were tested for antibodies against both the citrullinated (Cit) and the non-citrullinated (Arg) form of 2 cyclic synthetic peptides. In 33 patients, a follow-up sample was tested six months after starting anti-mycobacterial drugs. A substantial proportion of patients with mycobacterial infections demonstrated antibodies against 0401Cit, 0401Arg, 0722Cit and 0722Arg. Fourteen patients demonstrated anti-0401Cit, 83 anti-0401Arg, 22 anti-0722Cit and 61 anti-0722Arg, while none of these antibodies were detected in the 20 healthy controls. All the patients but one, who were anti-0401Cit and anti-0722Cit positive, demonstrated reactivity against the respective Arg peptide. In the subset of 33 patients with a follow-up test six months after starting treatment, the mean levels of antibodies to 0401Cit, 0401Arg, 0722Cit and 0722Arg significantly decreased after treatment. All the patients who were anti-0401Cit and anti-0722Cit positive turned negative after treatment. The presence of anti-0401Cit/Arg and anti-0722Cit/Arg was found to be significantly correlated with the presence of HIV. ACPA may be found in patients with TB. In most of the cases, the reactivity is citrulline independent. A positive cyclic citrullinated peptide (CCP) test in these patients should therefore be interpreted with care, and preferably followed by a control ELISA with a non-citrullinated antigen.

  15. The anti-cyclic citrullinated peptide response in tuberculosis patients is not citrulline-dependent and sensitive to treatment

    PubMed Central

    2010-01-01

    Introduction Patients with tuberculosis (TB) frequently produce anti-citrullinated protein antibodies (ACPA). The objective of this study is to characterize the citrulline-dependence of the ACPA reactivity in sera of patients with mycobacterium infections. Methods Serum samples of 134 patients with untreated mycobacterium infections (122 TB, 12 nontuberculous mycobacterium) were tested for antibodies against both the citrullinated (Cit) and the non-citrullinated (Arg) form of 2 cyclic synthetic peptides. In 33 patients, a follow-up sample was tested six months after starting anti-mycobacterial drugs. Results A substantial proportion of patients with mycobacterial infections demonstrated antibodies against 0401Cit, 0401Arg, 0722Cit and 0722Arg. Fourteen patients demonstrated anti-0401Cit, 83 anti-0401Arg, 22 anti-0722Cit and 61 anti-0722Arg, while none of these antibodies were detected in the 20 healthy controls. All the patients but one, who were anti-0401Cit and anti-0722Cit positive, demonstrated reactivity against the respective Arg peptide. In the subset of 33 patients with a follow-up test six months after starting treatment, the mean levels of antibodies to 0401Cit, 0401Arg, 0722Cit and 0722Arg significantly decreased after treatment. All the patients who were anti-0401Cit and anti-0722Cit positive turned negative after treatment. The presence of anti-0401Cit/Arg and anti-0722Cit/Arg was found to be significantly correlated with the presence of HIV. Conclusions ACPA may be found in patients with TB. In most of the cases, the reactivity is citrulline independent. A positive cyclic citrullinated peptide (CCP) test in these patients should therefore be interpreted with care, and preferably followed by a control ELISA with a non-citrullinated antigen. PMID:20100318

  16. A comparison of performance of anti-cyclic citrullinated peptide 2 and citrullinated protein antibodies in the diagnosis of rheumatoid arthritis in Iranian patients.

    PubMed

    Aflaky, Elham; Shenavandeh, Saeedeh; Ashraf, Mohammad Javad

    2010-02-01

    Antibodies to citrullinated proteins and rheumatoid factor (RF) are widely used in patients with rheumatoid arthritis (RA) and the antibodies to citrullinated proteins appear to be the most specific markers of the disease. The objective was to compare the diagnostic performance of the anti-cyclic citrullinated peptide 2 (anti-CCP2) and citrullinated protein Antibodies (CPA) with RF in the diagnosis of RA. Serum samples of 139 patients with RA and 131 patients with other rheumatic diseases were checked for anti-CCP2, CPA uses citrullinated recombinant rat filaggrin as the antigen assay, and RF. The specificity, sensitivity, and receiver operating characteristic (ROC) of tests were then compared. The sensitivity of anti-CCP2, CPA, and RF were 82.7, 83.5, and 61.5%, respectively. The specificities of the tests were 91.2, 78.6, and 90.5%, respectively. The area under ROC curves for the tests were 0.925, 0.890, and 0.847, respectively. Exclusion of overlaps was associated with improved specificity for CPA but no change in the specificity of RF and anti-CCP. The sensitivity of anti-CCP2, CPA, and RF were 66.7, 77.8, and 51.9% for patients with early RA, respectively. The findings of the present study indicate that anti-CCP2 might be of a better diagnostic value for the diagnosis of RA. They also showed that CPA and in the second place anti-CCP2 were useful in the diagnosis of early RA.

  17. Highly sensitive immunoassay of anti-cyclic citrullinated peptide marker using surface-enhanced Raman scattering detection

    NASA Astrophysics Data System (ADS)

    Chon, H.; Lee, S.; Wang, R.; Bang, S.-Y.; Lee, H.-S.; Bae, S.-C.; Hong, S. H.; Yoon, Y. H.; Lim, D.; Choo, J.

    2015-07-01

    We report a highly sensitive anti-cyclic citrullinated peptide (anti-CCP) detection method for early diagnosis of rheumatoid arthritis (RA) using surface-enhanced Raman scattering (SERS)-based immunoassay. Herein, cyclic citrullinated peptide (CCP)-conjugated magnetic beads and anti-human IgG-conjugated hollow gold nanospheres (HGNs) were used as substrates and SERS nano-tags, respectively. First, its detection sensitivity was evaluated using anti-CCP standard solutions. Then quantitative anti-CCP levels, determined by the SERS-based assay, were compared with those obtained from three commercially available anti-CCP assay kits (Immunoscan CCPlus, ImmunnLisa™ CCP and BioPlex™ 2200) to assess its potential utility as a clinical tool. Finally, clinical samples from 20 RA patients were investigated using them. In the SERS-based assay, the anti-CCP level in human serum was successfully determined by monitoring the characteristic Raman peak intensity of SERS nano-tags. The diagnostic performance of our SERS-based immunoassay for clinical samples shows a good agreement with those measured by three commercial anti-CCP kits. In addition, our SERS-based assay results are more consistent in the low concentration range (0-25 U/mL) than those achieved by the commercial kits. Accordingly, it is estimated that the SERS-based assay is a potentially useful diagnostic tool for early diagnosis of RA.

  18. Antibodies to a new viral citrullinated peptide, VCP2: fine specificity and correlation with anti-cyclic citrullinated peptide (CCP) and anti-VCP1 antibodies

    PubMed Central

    Pratesi, F; Tommasi, C; Anzilotti, C; Puxeddu, I; Sardano, E; Di Colo, G; Migliorini, P

    2011-01-01

    Anti-citrullinated protein/peptide antibodies (ACPA) are a hallmark of rheumatoid arthritis (RA) and can be measured using different citrullinated substrates. In this paper we describe a new viral citrullinated peptide – VCP2 – derived from the Epstein–Barr virus-encoded protein EBNA-2 and analyse its potential as substrate for ACPA detection. Analysing sera from 100 RA patients and 306 controls, anti-VCP2 immunoglobulin (Ig)G were found in 66% of RA sera, IgM in 46% and IgA in 39%, compared with less than 3% of control sera. Anti-VCP2 IgG was associated with erosive arthritis, the presence of rheumatoid factor and anti-VCP1 and anti-cyclic citrullinated peptide (CCP) antibodies. Anti-VCP2 antibodies were detected in 1% and anti-VCP1 antibodies in 4% of CCP-negative RA sera; conversely, 3% of the VCP-negative sera were CCP-positive. Taken together, these data suggest that VCP2 could offer a valuable tool for ACPA detection. Inhibition assays showed that two non-overlapping epitopes – a citrulline–glycine stretch shared between VCP1 and VCP2 and the N-terminal portion of the VCP2 sequence – were targeted by anti-VCP2 antibodies. Moreover, in some RA sera that tested positive in CCP and VCP2 assays, preincubation with VCP2 inhibited binding to CCP, whereas in other sera the binding was unaffected. Thus, the reactivity with more than one ACPA substrate might be due in some RA patients to antibody populations with different specificities, and in others to cross-reactive antibody populations. Finally, affinity-purified anti-VCP2 antibodies immunoprecipitated deiminated Epstein–Barr virus nuclear antigen (EBNA-2) from an EBNA-2-transfected cell line, suggesting that viral sequences may be involved in the generation of the ACPA response. PMID:21413944

  19. Citrulline Dependence of Anti-Cyclic Citrullinated Peptide Antibodies in Systemic Lupus Erythematosus as a Marker of Deforming/Erosive Arthritis

    PubMed Central

    KAKUMANU, PRASANTHI; SOBEL, ERIC S.; NARAIN, SONALI; LI, YI; AKAOGI, JUN; YAMASAKI, YOSHIOKI; SEGAL, MARK S.; HAHN, PAULETTE C.; CHAN, EDWARD K. L.; REEVES, WESTLEY H.; SATOH, MINORU

    2009-01-01

    Objective Anti-cyclic citrullinated peptide (CCP) antibodies are a serological marker for rheumatoid arthritis (RA); up to 10%–15% of patients with systemic lupus erythematosus (SLE) are also positive. While anti-CCP in RA is citrulline-dependent, anti-CCP in some other diseases is citrulline-independent and reacts with both CCP and the unmodified (arginine-containing) cyclic arginine peptide (CAP). We investigated the citrulline dependence of anti-CCP and its significance in the arthritis of SLE. Methods IgG anti-CCP was compared by ELISA to anti-CAP in sera from patients with SLE (n = 335) and RA (n = 47) and healthy controls (n = 35). SLE patients were divided into 5 groups based on their joint involvement: subset I: deforming/erosive arthritis (n = 20); II: arthritis fulfilling (or likely fulfilling) American College of Rheumatology criteria for RA but without erosions (n = 18); III: joint swelling but not fulfilling RA criteria (n = 39); IV: arthritis without documented joint swelling (n = 194); and V: no arthritis (n = 58). Results Anti-CCP (> 1.7 units) was found in 68% (32/47) of patients with RA and 17% (55/329) of those with SLE. It was more common in SLE patients with deforming/erosive arthritis (38%). High anti-CCP (> 10 units) was found in RA (26%) and deforming/erosive SLE (12%). High anti-CCP/CAP ratios (> 2, indicating a selectivity to CCP) were found in 91% of anti-CCP-positive RA and 50% of anti-CCP-positive SLE patients with deforming/erosive arthritis. Patients from subset II did not have high anti-CCP/CAP. Conclusion Citrulline dependence or high levels (> 10) of anti-CCP were common in SLE patients with deforming/erosive arthritis, while most anti-CCP in SLE patients was citrulline-independent. This may be useful in identifying a subset of SLE patients with high risk for development of deforming/erosive arthritis. PMID:19884269

  20. Association analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope and smoking status in Brazilian patients with rheumatoid arthritis.

    PubMed

    Yazbek, Michel Alexandre; Barros-Mazon, Silvia de; Rossi, Cláudio Lúcio; Londe, Ana Carolina; Costallat, Lilian Tereza Lavras; Bertolo, Manoel Barros

    2011-01-01

    Epstein-Barr virus exposure appears to be an environmental trigger for rheumatoid arthritis that interacts with other risk factors. Relationships among anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status have been observed in patients with rheumatoid arthritis from different populations. To perform an association analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status in Brazilian patients with rheumatoid arthritis. In a case-control study, 140 rheumatoid arthritis patients and 143 healthy volunteers who were matched for age, sex, and ethnicity were recruited. Anti-Epstein-Barr nuclear antigen-1 antibodies and anti-cyclic citrullinated peptide antibodies were examined using an enzyme-linked immunosorbent assay, and shared epitope alleles were identified by genotyping. Smoking information was collected from all subjects. A comparative analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status was performed in the patient group. Logistic regression analysis models were used to analyze the risk of rheumatoid arthritis. Anti-Epstein-Barr nuclear antigen-1 antibodies were not associated with anti-cyclic citrullinated peptide antibodies, shared epitope alleles, or smoking status. Anti-cyclic citrullinated peptide antibody positivity was significantly higher in smoking patients with shared epitope alleles (OR = 3.82). In a multivariate logistic regression analysis using stepwise selection, only anti-cyclic citrullinated peptide antibodies were found to be independently associated with rheumatoid arthritis (OR = 247.9). Anti-Epstein-Barr nuclear antigen-1 antibodies did not increase the risk of rheumatoid arthritis and were not associated with the rheumatoid arthritis risk factors studied. Smoking and shared epitope alleles were correlated with anti-cyclic

  1. Antibodies to a new viral citrullinated peptide, VCP2: fine specificity and correlation with anti-cyclic citrullinated peptide (CCP) and anti-VCP1 antibodies.

    PubMed

    Pratesi, F; Tommasi, C; Anzilotti, C; Puxeddu, I; Sardano, E; Di Colo, G; Migliorini, P

    2011-06-01

    Anti-citrullinated protein/peptide antibodies (ACPA) are a hallmark of rheumatoid arthritis (RA) and can be measured using different citrullinated substrates. In this paper we describe a new viral citrullinated peptide - VCP2 - derived from the Epstein-Barr virus-encoded protein EBNA-2 and analyse its potential as substrate for ACPA detection. Analysing sera from 100 RA patients and 306 controls, anti-VCP2 immunoglobulin (Ig)G were found in 66% of RA sera, IgM in 46% and IgA in 39%, compared with less than 3% of control sera. Anti-VCP2 IgG was associated with erosive arthritis, the presence of rheumatoid factor and anti-VCP1 and anti-cyclic citrullinated peptide (CCP) antibodies. Anti-VCP2 antibodies were detected in 1% and anti-VCP1 antibodies in 4% of CCP-negative RA sera; conversely, 3% of the VCP-negative sera were CCP-positive. Taken together, these data suggest that VCP2 could offer a valuable tool for ACPA detection. Inhibition assays showed that two non-overlapping epitopes - a citrulline-glycine stretch shared between VCP1 and VCP2 and the N-terminal portion of the VCP2 sequence - were targeted by anti-VCP2 antibodies. Moreover, in some RA sera that tested positive in CCP and VCP2 assays, preincubation with VCP2 inhibited binding to CCP, whereas in other sera the binding was unaffected. Thus, the reactivity with more than one ACPA substrate might be due in some RA patients to antibody populations with different specificities, and in others to cross-reactive antibody populations. Finally, affinity-purified anti-VCP2 antibodies immunoprecipitated deiminated Epstein-Barr virus nuclear antigen (EBNA-2) from an EBNA-2-transfected cell line, suggesting that viral sequences may be involved in the generation of the ACPA response. © 2011 The Authors. Clinical and Experimental Immunology © 2011 British Society for Immunology.

  2. Anti-Cyclic Citrullinated Peptide Assays Differ in Subjects at Elevated Risk for Rheumatoid Arthritis and Subjects with Established Disease

    PubMed Central

    Demoruelle, M. Kristen; Parish, Mark C.; Derber, Lezlie A.; Kolfenbach, Jason R.; Hughes-Austin, Jan M.; Weisman, Michael H.; Gilliland, William; Edison, Jess D.; Buckner, Jane H.; Mikuls, Ted R.; O’Dell, James R.; Keating, Richard M.; Gregersen, Peter K.; Norris, Jill M.; Holers, V. Michael; Deane, Kevin D.

    2013-01-01

    Objective To compare commonly-available tests for antibodies to citrullinated protein antigens (ACPAs) for diagnostic accuracy and assay agreement in established rheumatoid arthritis (RA) and subjects at elevated risk for RA. Methods ELISA testing for anti-cyclic citrullinated peptide (anti-CCP) antibodies was performed using CCP2 (Axis-Shield) and CCP3.1 (IgA/IgG INOVA) in the following subjects: 1) probands with established RA (N=340) from the Studies of the Etiology of RA (SERA), 2) first degree relatives (FDRs) without RA (family members of SERA RA probands; N=681), 3) Department of Defense Serum Repository (DoDSR) RA cases with pre-diagnosis samples (N=83; 47/83 also had post-diagnosis samples), and 4) blood-donor and DoDSR controls (N=283). Results In established RA, CCP2 was more specific (99.2% vs. 93.1%, p<0.01), but less sensitive (58.7% vs. 67.4%, p=0.01) than CCP3.1, with specificity of CCP3.1 increasing to 97.2% if levels ≥3 times the standard cut-off level were considered. In all subjects, at standard cut-off levels, CCP3.1 positivity was more prevalent. In DoDSR cases, CCP2 was more specific than CCP3.1 for a future diagnosis of RA, and higher CCP levels trended towards greater specificity for disease onset within 2 years. At standard cut-off levels, assay agreement was good in established RA (kappa=0.76), but poor in FDRs without inflammatory arthritis (kappa=0.25). Conclusion Anti-CCP assays differ to an extent that may be meaningful in diagnosing RA in patients with inflammatory arthritis, and in evaluating the natural history of RA development in subjects at-risk for future RA. Mechanisms underlying these differences in test performance need further investigation. PMID:23686569

  3. Diagnostic value of the anti-Sa antibody compared with the anti-cyclic citrullinated peptide antibody in rheumatoid arthritis.

    PubMed

    Iwaszkiewicz, Cezary; Puszczewicz, Mariusz; Białkowska-Puszczewicz, Grażyna

    2015-01-01

    To evaluate the prevalence and diagnostic significance of the autoantibody against citrullinated vimentin (anti-Sa) compared with the widely used anti-cyclic citrullinated peptide autoantibody (anti-CCP) in patients with rheumatoid arthritis (RA). One hundred and sixty-nine patients hospitalized at the Department of Rheumatology and Internal Medicine, Poznan University of Medical Sciences, Poznań, Poland, were enrolled in a cross-sectional study and divided into two groups. The RA group comprised 41 patients diagnosed as having RA. The non-RA control group included 128 individuals with a variety of rheumatic disorders. Serum anti-Sa and anti-CCP measurements were performed by enzyme-linked immunosorbent assay. The sensitivity and specificity of anti-Sa for the diagnosis of RA was 36.6% and 96.9%, respectively. For the anti-CCP test, the sensitivity was 65.9% and the specificity was 95.3%. Concomitant presence of anti-Sa and anti-CCP was determined in 36.6% of the patients with RA, whereas isolated positivity of anti-Sa was not observed. Anti-Sa positive RA patients had significantly higher anti-CCP levels compared to anti-Sa negative subjects (P < 0.05). With regard to the relatively low diagnostic sensitivity and the lack of cases identified by anti-Sa alone, we were unable to demonstrate any additional diagnostic value of the anti-Sa autoantibody in comparison to the anti-CCP autoantibody. To the authors' best knowledge, this is the first study among Polish patients verifying the clinical utility of anti-Sa in the diagnosis of RA. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  4. A Systematic Review of Serum Biomarkers Anti-Cyclic Citrullinated Peptide and Rheumatoid Factor as Tests for Rheumatoid Arthritis

    PubMed Central

    Taylor, Peter; Gartemann, Juliane; Hsieh, Jeanie; Creeden, James

    2011-01-01

    This systematic review assesses the current status of anti-cyclic citrullinated peptide (anti-CCP) and rheumatoid factor (RF) tests in the diagnosis and prognosis of rheumatoid arthritis (RA). We reviewed publications on tests and biomarkers for early diagnosis of RA from English-language MEDLINE-indexed journals and non-MEDLINE-indexed sources. 85 publications were identified and reviewed, including 68 studies from MEDLINE and 17 non-MEDLINE sources. Anti-CCP2 assays provide improved sensitivity over anti-CCP assays and RF, but anti-CCP2 and RF assays in combination demonstrate a positive predictive value (PPV) nearing 100%, greater than the PPV of either of the tests alone. The combination also appears to be able to distinguish between patients whose disease course is expected to be more severe and both tests are incorporated in the 2010 ACR Rheumatoid Arthritis Classification Criteria. While the clinical value of anti-CCP tests has been established, differences in cut-off values, sensitivities and specificities exist between first-, second- and third-generation tests and harmonization efforts are under way. Anti-CCP and RF are clinically valuable biomarkers for the diagnosis and prognosis of RA patients. The combination of the two biomarkers in conjunction with other clinical measures is an important tool for the diagnosis and management of RA patients. PMID:21915375

  5. Circulating anti-cyclic citrullinated peptide antibody in patients with rheumatoid arthritis and chronic obstructive pulmonary disease.

    PubMed

    Yang, Deng-Ho; Tu, Chuan-Chou; Wang, Shou-Cheng; Wei, Cheng-Chung; Cheng, Ya-Wen

    2014-07-01

    Anti-cyclic citrullinated peptide (anti-CCP) antibody is highly specific for diagnosing rheumatoid arthritis (RA). Cigarette smoking is a lifestyle and environmental factor associated with anti-CCP production and is strongly associated with chronic obstructive pulmonary disease (COPD). This study assessed levels of anti-CCP antibodies and rheumatoid factor (RF) among patients with RA and COPD. The study sample comprised 63 patients with RA and 70 patients with COPD, all of whom underwent assessment of anti-CCP antibody and RF levels. Testing revealed that 54.2% of RA patients and 0% of COPD patients were positive for anti-CCP antibodies. Additionally, 82.5% of RA patients and 42% of COPD patients were positive for RF. Among RA patients, levels of anti-CCP antibodies were higher among smokers than among nonsmokers (242.7 ± 128.3 vs. 68.1 ± 112.1, P < 0.001). COPD patients had low titers of RF but were negative for anti-CCP antibodies. The presence of anti-CCP antibodies was a reliable serologic marker in RA diagnosis and was associated with cigarette smoking.

  6. PTPN22 -1123G>C polymorphism and anti-cyclic citrullinated protein antibodies in rheumatoid arthritis.

    PubMed

    Muñoz-Valle, José Francisco; Padilla-Gutiérrez, Jorge Ramón; Hernández-Bello, Jorge; Ruiz-Noa, Yeniley; Valle, Yeminia; Palafox-Sánchez, Claudia Azucena; Parra-Rojas, Isela; Gutiérrez-Ureña, Sergio Ramón; Rangel-Villalobos, Hector

    2017-08-10

    The protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene encodes an important negative regulator of T-cell activation, lymphoid-specific phosphatase -Lyp- and has been associated with different autoimmune disorders. The PTPN22 -1123G>C polymorphism appears to affect the transcriptional control of this gene, but to date, the biological significance of this polymorphisms on rheumatoid arthritis (RA) risk remains unknown. We evaluate the association of PTPN22 -1123G>C polymorphism with anti-cyclic citrullinated protein antibodies (anti-CCP) and risk for RA in population from Western Mexico. A transversal analytic study, which enrolled 300 RA patients classified according to ACR-EULAR criteria and 300 control subjects (CS) was conducted. The -1123 G>C polymorphism was genotyped by PCR-RFLP. The anti-CCP antibodies levels were quantified by ELISA kit. We found a higher prevalence of homozygous PTPN22 -1123CC genotype in CS than in RA patients (OR 0.41; 95% confidence interval 0.24-0.71; P=.001), suggesting a potential protective effect against RA. Concerning anti-CCP levels, the CC genotype carriers showed the lowest median levels in RA (P<.05). The PTPN22 -1123CC genotype is a protector factor to RA in a Mexican-mestizo population and is associated with low anti-CCP antibodies. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  7. Diagnostic value of anti-cyclic citrullinated peptide antibody for rheumatoid arthritis in a Chinese population: a meta-analysis.

    PubMed

    Gao, Fei; Ren, Lei; Zhang, Cai-Qin; Mu, Feng-Yun; You, Yan-Qiu; Liu, Yan-Hong

    2012-10-01

    To use meta-analysis to determine the accuracy of anti-cyclic citrullinated peptide (CCP) antibody in diagnosis of patients with rheumatoid arthritis (RA) in a Chinese population, we searched MEDLINE and CNKI databases for studies published in English or Chinese between January 2000 and June 2010. Two investigators independently evaluated studies for inclusion, data extraction, and quality assessment. We used a random-effects model to combine estimates of sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR). One hundred and eighteen studies met our inclusion criteria. All studies were of high quality. The summary estimates for anti-CCP antibody in the diagnosis of RA in a Chinese population were as follows: sensitivity 0.65 (95% confidence interval (CI) 0.65-0.66), specificity 0.95 (95% CI 0.95-0.96), positive likelihood ratio (LR+) 15.84 (95% CI 13.55-18.54), negative likelihood ratio (LR-) 0.33 (95% CI 0.31-0.35), and diagnostic odds ratio (DOR) 51.60 (95% CI 43.64-61.01). With high specificity and moderate sensitivity, anti-CCP antibody tests play an important role in conforming the diagnosis of RA in a Chinese population.

  8. The relationship between the presence of anti-cyclic citrullinated peptide antibodies and clinical phenotype in very early rheumatoid arthritis.

    PubMed

    Cader, Mohammed Z; Filer, Andrew D; Buckley, Christopher D; Raza, Karim

    2010-08-23

    Anti-cyclic citrullinated peptide (anti-CCP) antibodies are highly specific for RA, but are not detectable in all RA patients. The aim of this study was to establish whether the clinical phenotypes of anti-CCP positive and negative disease are distinct at the earliest clinically apparent phase of disease. Patients were recruited from the Birmingham early inflammatory arthritis clinic. Participants were included in the current study if they presented within 3 months of symptom onset and fulfilled 1987 ACR criteria for RA at some point during an 18 month follow-up. Data were collected on demographic variables, joint symptoms and tender (n = 68) and swollen (n = 66) joint counts. CRP, ESR, rheumatoid factor and anti-CCP2 status were measured. 92 patients were included (48 anti-CCP positive). The anti-CCP positive and negative groups were comparable in terms of demographic variables, inflammatory markers, joint counts and 1987 ACR classification criteria, except that more anti-CCP positive patients were rheumatoid factor positive (83.3% vs. 11.4%, p < 0.01). There was no significant difference in the pattern of joint involvement, except for an increased prevalence of knee joint swelling in anti-CCP positive patients (42.9% vs. 22.2%, p = 0.03). Patients with and without anti-CCP antibodies present in a similar way, even within three months of clinically apparent disease that eventually develops into RA.

  9. Anti-Cyclic Citrullinated Peptide (Anti-CCP) and Anti-Mutated Citrullinated Vimentin (Anti-MCV) Relation with Extra-Articular Manifestations in Rheumatoid Arthritis

    PubMed Central

    Gonzalez-Lopez, Laura; Rocha-Muñoz, Alberto Daniel; Ponce-Guarneros, Manuel; Flores-Chavez, Alejandra; Salazar-Paramo, Mario; Cardona-Muñoz, Ernesto German; Fajardo-Robledo, Nicte Selene; Zavaleta-Muñiz, Soraya Amali; Garcia-Cobian, Teresa; Gamez-Nava, Jorge Ivan

    2014-01-01

    We evaluated the association between anti-cyclic citrullinated peptide antibodies (anti-CCP) and anti-mutated citrullinated vimentin antibodies (anti-MCV) with the presence of extra-articular (ExRA) manifestations in 225 patients with rheumatoid arthritis (RA). Ninety-five patients had ExRA and 130 had no ExRA. There was no association of anti-CCP and anti-MCV levels with the presence of ExRA as total group (P = 0.40 and P = 0.91, resp.). Making an analysis of individual manifestations, rheumatoid nodules were associated with positivity for rheumatoid factor (RF); (P = 0.01), anti-CCP (P = 0.048), and anti-MCV (P = 0.02). Instead, RF, anti-CCP, or anti-MCV were not associated with SS, chronic anemia, or peripheral neuropathy. Levels of anti-CCP correlated with the score of the Health Assessment Questionnaire-Disability Index (HAQ-Di) (r = 0.154, P = 0.03), erythrocyte sedimentation rate (ESR); (r = 0.155, P = 0.03), and RF (P = 0.254, P < 0.001), whereas anti-MCV titres only correlated with RF (r = 0.169, P = 0.02). On adjusted analysis, ExRA was associated with longer age (P = 0.015), longer disease duration (P = 0.007), higher DAS-28 score (P = 0.002), and higher HAQ-DI score (P = 0.007), but serum levels of anti-CCP and anti-MCV were not associated. These findings show the need to strengthen the evaluation of the pathogenic mechanisms implied in each specific ExRA manifestation. PMID:24804270

  10. Anti-cyclic citrullinated peptide (anti-CCP) and anti-mutated citrullinated vimentin (anti-MCV) relation with extra-articular manifestations in rheumatoid arthritis.

    PubMed

    Gonzalez-Lopez, Laura; Rocha-Muñoz, Alberto Daniel; Ponce-Guarneros, Manuel; Flores-Chavez, Alejandra; Salazar-Paramo, Mario; Nava, Arnulfo; Cardona-Muñoz, Ernesto German; Fajardo-Robledo, Nicte Selene; Zavaleta-Muñiz, Soraya Amali; Garcia-Cobian, Teresa; Gamez-Nava, Jorge Ivan

    2014-01-01

    We evaluated the association between anti-cyclic citrullinated peptide antibodies (anti-CCP) and anti-mutated citrullinated vimentin antibodies (anti-MCV) with the presence of extra-articular (ExRA) manifestations in 225 patients with rheumatoid arthritis (RA). Ninety-five patients had ExRA and 130 had no ExRA. There was no association of anti-CCP and anti-MCV levels with the presence of ExRA as total group (P = 0.40 and P = 0.91, resp.). Making an analysis of individual manifestations, rheumatoid nodules were associated with positivity for rheumatoid factor (RF); (P = 0.01), anti-CCP (P = 0.048), and anti-MCV (P = 0.02). Instead, RF, anti-CCP, or anti-MCV were not associated with SS, chronic anemia, or peripheral neuropathy. Levels of anti-CCP correlated with the score of the Health Assessment Questionnaire-Disability Index (HAQ-Di) (r = 0.154, P = 0.03), erythrocyte sedimentation rate (ESR); (r = 0.155, P = 0.03), and RF (P = 0.254, P < 0.001), whereas anti-MCV titres only correlated with RF (r = 0.169, P = 0.02). On adjusted analysis, ExRA was associated with longer age (P = 0.015), longer disease duration (P = 0.007), higher DAS-28 score (P = 0.002), and higher HAQ-DI score (P = 0.007), but serum levels of anti-CCP and anti-MCV were not associated. These findings show the need to strengthen the evaluation of the pathogenic mechanisms implied in each specific ExRA manifestation.

  11. Determination of anti-cyclic citrullinated peptide antibodies in the sera of patients with juvenile idiopathic arthritis.

    PubMed

    Low, Jason M; Chauhan, Anil K; Kietz, Daniel A; Daud, Umar; Pepmueller, Peri H; Moore, Terry L

    2004-09-01

    Anti-cyclic citrullinated peptide (anti-CCP) antibodies have been found in sera of 76% of patients with rheumatoid arthritis (RA), mainly in rheumatoid factor (RF) positive patients, with a specificity of 96%. We evaluated the presence of anti-CCP antibodies in patients with juvenile idiopathic arthritis (JIA) and assessed the possibility of synthetic citrullinated peptides as antigenic determinants in JIA. The presence of anti-CCP antibodies was determined using 3 synthetic citrullinated peptide variants and 2 commercial kits (Inova Diagnostics and Axis-Shield Diagnostics) optimized for detecting JIA-specific antibodies in serum by an ELISA based assay. We evaluated 66 patients with JIA (16 RF positive polyarthritis, 18 RF negative polyarthritis, 19 oligoarthritis, and 13 systemic arthritis). We also tested 9 adult RA patients, 34 patients with systemic lupus erythematosus (SLE), and 25 healthy persons as controls. Significant concentrations of anti-CCP antibodies were detected in the majority of RF positive JIA patients with polyarthritis. Using the 2 synthetic linear peptides, 12/16 (75%) were positive; 9/12 (75%) were positive with the Inova kit and 9/10 (90%) were positive with the Axis-Shield kit. However, utilizing the synthetic linear peptides, significant concentrations of anti-CCP antibodies were detected in 51/66 (77%) JIA patients, including 15/18 (83%) RF negative polyarthritis, 16/19 (84%) oligoarthritis, and 8/13 (62%) systemic arthritis patients. No healthy control showed elevated antibody levels. In contrast, 4/9 (44%) patients with adult RA and 2/6 (33%) with SLE had elevated anti-CCP levels. The synthetic cyclic variant cfc-1-cyc yielded significant anti-CCP levels for 13/14 (93%) patients with RF negative polyarthritis, 6/10 (60%) with oligoarthritis, and 3/7 (43%) with systemic arthritis, and 8/9 (88%) RF positive patients. No healthy control had increased anti-CCP levels. However, 4/9 (44%) adult RA and 9/34 (26%) SLE patients were found to

  12. Significance of Anti-cyclic Citrullinated Peptide Autoantibodies in Immune-mediated Inflammatory Skin Disorders with and without Arthritis

    PubMed Central

    Grover, Chander; Kashyap, Bineeta; Daulatabad, Deepashree; Dhawan, Amit; Kaur, Iqbal R

    2016-01-01

    Background: Anti-cyclic citrullinated peptides (CCPs) are autoantibodies directed against citrullinated peptides. Rheumatoid factor (RF), an antibody against the Fc portion of IgG, is known to form immune complexes and contribute to the etiopathogenesis of various skin disorders. C-reactive protein (CRP), an acute-phase protein, increases following secretion of interleukin-6 from macrophages and T cells. Anti-CCP, RF, and CRP are well-established immune-markers, their diagnostic potential in immune-mediated skin disorders remains less widely studied. Aims and Objectives: To determine the correlation between anti-CCP, RF, and CRP in immune-mediated inflammatory skin diseases. Materials and Methods: About 61 clinically diagnosed cases of various immune-mediated skin diseases (psoriasis [n = 38], connective tissue diseases such as systemic lupus erythematosus and systemic sclerosis [n = 14], and immunobullous disorders including pemphigus vulgaris and pemphigus foliaceus [n = 9]) were included in the study. These patients were subclassified on the basis of presence or absence of arthritis. Arthritis was present in nine cases of psoriasis and seven connective tissue disorder patients. Detection of serum anti-CCP was done using enzyme-linked immunosorbent assay, whereas CRP and RF levels were detected using latex agglutination technique. Results: Of the 61 specimens, 14.75% had elevated serum anti-CCP levels. RF and CRP levels were elevated in 18.03% and 39.34% specimens, respectively. RF was elevated in 13.16% of inflammatory and 42.88% of connective tissue disorders, whereas anti-CCP was raised in 10.53% of inflammatory and 35.71% of connective tissue disorders. CRP positivity was highest in connective tissue disorders (50%), followed by 39.47% in inflammatory and 22.22% in immunobullous conditions. In none of the immunobullous patients, anti-CCP or RF levels were found to be elevated. Association of the presence of arthritis with elevated anti-CCP was found to be

  13. Significance of Anti-cyclic Citrullinated Peptide Autoantibodies in Immune-mediated Inflammatory Skin Disorders with and without Arthritis.

    PubMed

    Grover, Chander; Kashyap, Bineeta; Daulatabad, Deepashree; Dhawan, Amit; Kaur, Iqbal R

    2016-01-01

    Anti-cyclic citrullinated peptides (CCPs) are autoantibodies directed against citrullinated peptides. Rheumatoid factor (RF), an antibody against the Fc portion of IgG, is known to form immune complexes and contribute to the etiopathogenesis of various skin disorders. C-reactive protein (CRP), an acute-phase protein, increases following secretion of interleukin-6 from macrophages and T cells. Anti-CCP, RF, and CRP are well-established immune-markers, their diagnostic potential in immune-mediated skin disorders remains less widely studied. To determine the correlation between anti-CCP, RF, and CRP in immune-mediated inflammatory skin diseases. About 61 clinically diagnosed cases of various immune-mediated skin diseases (psoriasis [n = 38], connective tissue diseases such as systemic lupus erythematosus and systemic sclerosis [n = 14], and immunobullous disorders including pemphigus vulgaris and pemphigus foliaceus [n = 9]) were included in the study. These patients were subclassified on the basis of presence or absence of arthritis. Arthritis was present in nine cases of psoriasis and seven connective tissue disorder patients. Detection of serum anti-CCP was done using enzyme-linked immunosorbent assay, whereas CRP and RF levels were detected using latex agglutination technique. Of the 61 specimens, 14.75% had elevated serum anti-CCP levels. RF and CRP levels were elevated in 18.03% and 39.34% specimens, respectively. RF was elevated in 13.16% of inflammatory and 42.88% of connective tissue disorders, whereas anti-CCP was raised in 10.53% of inflammatory and 35.71% of connective tissue disorders. CRP positivity was highest in connective tissue disorders (50%), followed by 39.47% in inflammatory and 22.22% in immunobullous conditions. In none of the immunobullous patients, anti-CCP or RF levels were found to be elevated. Association of the presence of arthritis with elevated anti-CCP was found to be statistically significant. Although anti-CCP, RF, and CRP levels are

  14. Anti-Cyclic Citrullinated Peptide Antibody Is Associated with Interstitial Lung Disease in Patients with Rheumatoid Arthritis

    PubMed Central

    Zhao, Lidan; Li, Yang; Liu, Wei; Ren, Yan; Li, Yongzhe; Zeng, Xiaofeng; Zhang, Fengchun; Tang, Fulin; Shan, Guangliang; Zhang, Xuan

    2014-01-01

    Objective Patients with rheumatoid arthritis (RA) are at risk to develop RA-associated interstitial lung disease (RA-ILD). This retrospective study aimed to investigate the potential association of the positivity of serum anti-cyclic citrullinated peptide antibody (anti-CCP2) and rheumatoid factor (RF) with RA-ILD in RA patients. Methods A total of 285 RA patients were recruited at the inpatient service of Peking Union Medical College Hospital in China between 2004 and 2013. Individual patients were evaluated for the evidence of ILD. The concentrations of serum anti-CCP2 and RF in individual patients were measured. The potential risk factors for ILD in RA patients were assessed by univariate and multivariate models. Results There were 71 RA patients with RA-ILD, accounting for 24.9% in this population. The positive rates of anti-CCP2 and RF in the patients with RA-ILD were significantly higher than that in the patients with RA-only (88.7% vs. 67.3%, p<0.001; 84.5% vs. 70.6%, p = 0.02, respectively). Univariate and multivariate logistic regression analysis revealed that RA patients with positive serum anti-CCP2, but not RF, were associated with an increased risk of ILD (crude odds ratio [cOR] 3.83, 95% confidence interval [CI] 1.74–8.43, p<0.001; adjusted odds ratio [aOR] 3.50, 95% CI 1.52–8.04, p<0.001). Conclusion Our findings suggest that positive serum anti-CCP2, but not RF, may be associated with RA-ILD in RA patients. PMID:24743261

  15. Anti-cyclic citrullinated peptide antibodies in systemic lupus erythematosus patients with articular involvement: a predictive marker for erosive disease?

    PubMed

    Taraborelli, M; Inverardi, F; Fredi, M; Ceribelli, A; Cavazzana, I; Tincani, A; Franceschini, F

    2012-12-11

    A small number of systemic lupus erythematosus (SLE) patients develop an erosive disease. Some studies have suggested an association between anti-cyclic citrullinated (anti-CCP) antibodies and this pattern of arthritis, but their exact significance in SLE patients remains unclear. The aim of this study was to evaluate the prevalence of anti-CCP antibodies in SLE patients with different subsets of articular disease. Among 521 SLE patients followed in this center from 1976 to 2011, those with articular involvement (n=298) were selected to take part in the study. We searched for anti-CCP2 IgG antibodies in 198 patients using a commercial enzyme linked immunosorbent assay (Immunoscan RA, Eurodiagnostica). In 174 patients the results for rheumatoid factor (RF) by nephelometry were retrospectively collected. C reactive protein (CRP) was obtained from clinical records. Patients were classified into 3 groups: erosive, non-erosive deforming, non-erosive non-deforming arthritis. Results of the different tests were compared among the groups. P<0.05 was considered statistically significant. Anti-CCP antibodies were significantly associated with erosive disease. We also found that RF positivity and increased CRP were more frequent in erosive arthritis and erosive or non-deforming arthritis, respectively, than in non-erosive non-deforming arthritis. This study supports the evidence that anti-CCP antibodies could be a useful marker of erosive disease in SLE patients. Increase in RF and CRP could be an additional means of identifying lupus patients with arthritis at risk of a worse prognosis.

  16. The prevalence of rheumatoid factor isotypes and anti-cyclic citrullinated peptides in Malaysian rheumatoid arthritis patients.

    PubMed

    Gomez, Edmund Luke; Gun, Suk Chyn; Somnath, Sushela Devi; D'Souza, Beryl; Lim, Ai Lee; Chinna, Karuthan; Radhakrishnan, Ammu K

    2011-02-01

    The purpose of this study is to compare the prevalence of rheumatoid factor (RF) isotypes and second generation anti-cyclic citrullinated peptides (anti-CCP) in Malaysian rheumatoid arthritis (RA) patients. In this cross-sectional study, 147 established RA patients from three ethnic groups were recruited from a major rheumatology clinic in Malaysia. Enzyme-linked immunosorbent assays (ELISA) for serum RF isotypes IgA, IgG and IgM as well as second-generation anti-CCP were performed and the prevalence of each auto-antibody was compared in the three ethnic groups. The anti-CCP was the most prevalent auto-antibody in each of the ethnic groups, followed closely by RF IgM and RF IgG. Rheumatoid factor IgA was the least prevalent across all three ethnic groups. The anti-CCP-RF IgM combination provided the best test sensitivity. Seroprevalence of anti-CCP was strongly associated with the presence of each of the RF isotypes. The seroprevalence of RF and anti-CCP did not increase or decrease with advancing age, age at onset and disease duration. When used alone, anti-CCP provides a diagnostic advantage over RF IgM on the basis of test sensitivity. Considering the high cost of the anti-CCP assay, step-wise serum testing with IgM RF followed by anti-CCP may provide a more economically sensible option to optimize test sensitivity for RA. © 2010 The Authors. International Journal of Rheumatic Diseases © 2010 Asia Pacific League of Associations for Rheumatology and Blackwell Publishing Asia Pty Ltd.

  17. Anti-cyclic citrullinated peptide antibodies: a comparison of different assays for the diagnosis of rheumatoid arthritis.

    PubMed

    Debaugnies, F; Servais, G; Badot, V; Noubouossie, D; Willems, D; Corazza, F

    2013-01-01

    Anti-cyclic citrullinated peptide (anti-CCP) antibodies are highly specific markers of rheumatoid arthritis (RA). Considering the heterogeneity of the target antigens involved, and the test platforms and conjugates proposed in commercial anti-CCP assays, we assessed the diagnostic performances of four fully automated anti-CCP assays in a cohort of patients with RA compared to patients with other autoimmune and inflammatory disorders. We also evaluated the agreement between the qualitative results of these immunoassays. We evaluated three anti-CCP2 assays [Eurodiagnostica enzyme-linked immunosorbent assay (ELISA), Elecsys electrochemiluminescence immunoassay (ECLIA) on the Modular E170 Analyzer, and Zenit chemiluminescence immunoassay (CLIA) on the Zenit RA Analyzer] and one anti-CCP3 assay (Inova ELISA). ELISAs were performed on an automated workstation. Samples from 112 patients with RA and a disease control group of 136 patients (53 with autoimmune diseases, 65 non-autoimmune disorders, and 18 infectious diseases) were studied (included 161 samples submitted consecutively to the laboratory). At a fixed specificity of 92%, the anti-CCP3 assay presented the highest sensitivity (75%) compared to the anti-CCP2 assays evaluated (63-72%). The Zenit anti-CCP2 assay gave the most false-positive results (especially in patients with viral infections and connective tissue diseases). The agreement between assays ranged from 86.3% to 95.2% and Kappa coefficients ranged from 0.724 to 0.899. Recently released automated workstations provide a valuable alternative to ELISA to diagnose RA. However, differences in diagnostic performances are highlighted in our experience, especially for the Zenit assay. In our cohort, the anti-CCP3 assay gave slightly better performances than the anti-CCP2 assays (with the exception of the Zenit assay).

  18. Association of anti-cyclic citrullinated peptide antibodies with clinical and radiological disease severity in rheumatoid arthritis.

    PubMed

    Gupta, Ankit; Kaushik, Reshma; Kaushik, Rajeev M; Saini, Manju; Kakkar, Rajesh

    2014-01-01

    This study assessed an association of anti-cyclic citrullinated peptide antibodies (ACPA) with clinical and radiological disease severity in patients with rheumatoid arthritis (RA). Fifty patients diagnosed with RA as per 2010 revised American College of Rheumatology/ European League Against Rheumatism (ACR/EULAR) classification criteria were included in this cross-sectional study. Serum levels of ACPA, C-reactive protein (CRP) and rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), disease activity score with 28-joint counts and ESR (DAS28-ESR), patient's global assessment of disease activity using visual analogue scale (PtGA-VAS), modified health assessment questionnaire score (M-HAQ) and radiological damage in hands and feet (modified Larsen score) were determined. ACPA were positive in 48 (96%) and RF in 44 (88%) patients. Mean Larsen score was 19.82 ± 17.11 and mean DAS28-ESR 6.39 ± 1.59. A significant correlation of ACPA levels was seen with RF (p=0.03) and Larsen score (p=0.02) but not with DAS28-ESR (p=0.17) and M-HAQ (p=0.81). A significant correlation was seen between Larsen score and disease duration (p<0.0001), age (p=0.04), DAS28-ESR (p=0.001) and M-HAQ (p<0.0001). Multivariate analysis showed that painful joint count (p=0.003), ESR (p<0.001) and PtGA-VAS (p=0.009) were independently associated with clinical disease activity severity. Disease duration (p=0.01), ACPA levels (p=0.004) and DAS28-ESR (p=0.03) were independently associated with radiological joint damage. Serum ACPA levels correlate significantly with radiological severity of RA but not with clinical disease severity and are independently associated with radiological outcome.

  19. Anti-cyclic citrullinated Peptide antibody is associated with interstitial lung disease in patients with rheumatoid arthritis.

    PubMed

    Yin, Yufeng; Liang, Di; Zhao, Lidan; Li, Yang; Liu, Wei; Ren, Yan; Li, Yongzhe; Zeng, Xiaofeng; Zhang, Fengchun; Tang, Fulin; Shan, Guangliang; Zhang, Xuan

    2014-01-01

    Patients with rheumatoid arthritis (RA) are at risk to develop RA-associated interstitial lung disease (RA-ILD). This retrospective study aimed to investigate the potential association of the positivity of serum anti-cyclic citrullinated peptide antibody (anti-CCP2) and rheumatoid factor (RF) with RA-ILD in RA patients. A total of 285 RA patients were recruited at the inpatient service of Peking Union Medical College Hospital in China between 2004 and 2013. Individual patients were evaluated for the evidence of ILD. The concentrations of serum anti-CCP2 and RF in individual patients were measured. The potential risk factors for ILD in RA patients were assessed by univariate and multivariate models. There were 71 RA patients with RA-ILD, accounting for 24.9% in this population. The positive rates of anti-CCP2 and RF in the patients with RA-ILD were significantly higher than that in the patients with RA-only (88.7% vs. 67.3%, p<0.001; 84.5% vs. 70.6%, p = 0.02, respectively). Univariate and multivariate logistic regression analysis revealed that RA patients with positive serum anti-CCP2, but not RF, were associated with an increased risk of ILD (crude odds ratio [cOR] 3.83, 95% confidence interval [CI] 1.74-8.43, p<0.001; adjusted odds ratio [aOR] 3.50, 95% CI 1.52-8.04, p<0.001). Our findings suggest that positive serum anti-CCP2, but not RF, may be associated with RA-ILD in RA patients.

  20. Association of human leukocyte antigen DRB1 with anti-cyclic citrullinated peptide autoantibodies in Saudi patients with rheumatoid arthritis.

    PubMed

    Alrogy, Abdullah; Dirar, Abduallah; Alrogy, Waleed; Fakhoury, Hana; Hajeer, Ali

    2017-01-01

    The genetic association between human leukocyte antigen (HLA)-DRB1 alleles and the risk of development of autoantibodies has been investigated, but there are few studies from the Gulf region. To investigate the association between the HLA-DRB1 shared epitope and the risk for development of autoantibodies in rheumatoid arthritis (RA) patients in a Saudi population. Analytical cross-sectional study. Tertiary care hospital in Riyadh, Saudi Arabia. We enrolled consecutive Saudi RA patients attending the rheumatology clinic between January and April 2015. Previously published data on HLA typing on unmatched healthy controls were used for comparison. HLA typing was performed using sequence-specific oligonucleotide probes (SSOP). Rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) antibodies, and antinuclear antibodies (ANA) were also measured. Logistic regression analysis was used to study the autoantibodies as possible explanatory variables for the presence of the HLA-DRB1 shared epitope. The association between the presence of the shared epitope and the risk of developing anti-CCP antibodies, ANA, and RF. In 76 patients with RA, carrying the shared epitope was associated with a significantly higher risk of having RA [OR=2.65, 95% CI (1.42-4.94), P=.0009]. However, only HLA-DRB1*04:05 was significantly as.sociated with RA [OR=3.73, 95% CI (1.61-8.96), Pc=.016]. In the logistic regression analysis, only anti-CCP was significantly associated with the shared epitope [OR=14.51, 95% CI (1.53-137.49), P=.02]. Our analysis indicates that the presence of the HLA-DRB1 shared epitope is strongly associated with the development of anti-CCP antibodies in Saudi patients with RA. A larger sample size is needed to confirm our finding.

  1. Anti-cyclic citrullinated peptide-2 (CCP2) autoantibodies and extra-articular manifestations in Greek patients with rheumatoid arthritis.

    PubMed

    Alexiou, Ioannis; Germenis, Anastasios; Koutroumpas, Athanasios; Kontogianni, Anastasia; Theodoridou, Katerina; Sakkas, Lazaros I

    2008-04-01

    The objective of our study was to establish whether there is an association between rheumatoid arthritis with extra-articular manifestations (exRA) and anti-cyclic citrullinated peptide 2 (anti-CCP2) antibodies in Greeks. A retrospective study of 220 Greek patients with RA, 95 with exRA and 125 without extra-articular manifestations (cRA). Serum anti-CCP2 antibodies and IgM rheumatoid factor (RF) were measured. CCP2(+) were 65.3% of exRA and 58.4% of cRA patients. RF(+) were 69.5% of exRA and 60.0% of cRA patients. Among exRA patients, 37.9% had high serum anti-CCP2 antibody levels (>100 IU/ml) compared to 21.6% cRA patients (p = 0.008). Serositis and pulmonary fibrosis were found to be associated with high levels of anti-CCP2 antibodies (52.9 vs 26.6%, p = 0.02 and 63.6 vs 26.8%, p = 0.008, respectively). Serum RF levels were 265.0 +/- 52.0 IU/ml (mean +/- SEM) in exRA and 205.1 +/- 40.6 (mean +/- SEM) in cRA (NS). High serum RF levels (>268 IU/ml) were more likely to have sicca syndrome. In Greek patients with rheumatoid arthritis (RA), high serum anti-CCP2 antibodies are associated with serositis and pulmonary fibrosis. Therefore, anti-CCP2 antibodies have prognostic significance in patients with RA.

  2. Discriminative and diagnostic value of anti-cyclic citrullinated peptide antibodies in Iranian patients with rheumatoid arthritis.

    PubMed

    Moghimi, Jamileh; Ghorbani, Raheb; Hasani, Farnaz; Sheikhvatan, Mehrdad

    2013-03-01

    Most studies on the diagnostic utility of the anti-cyclic citrullinated peptide antibody (anti-CCP) test in rheumatoid arthritis (RA) have been performed in developed countries, with only a few done in the developing world. We undertook a cross-sectional study to determine the diagnostic utility of the rheumatoid factor (RF) and anti-CCP tests in urbanized Iranians with early RA. One hundred and ninety-three serum samples were obtained from consecutive patients who were diagnosed with RA. Serum samples of 254 ones without RA, consisting of other inflammatory polyarthritis disorders, were also collected as controls. RF was measured for IgM by latex agglutination test, and titers higher than 1/80 were considered positive. Anti-CCP was also assayed using an ELISA with 6.25 RU/ml as the threshold for a positive result. The anti-CCP had sensitivity, specificity, positive predictive value, and negative predictive value for a diagnosis of RA of 47.2, 92.9, 83.5, and 69.8 %, respectively. Those for RF were 57.0, 83.9, 72.8, and 72.0 %, respectively. For anti-CCP antibodies in combination with RF, they were 38.9, 96.5, 89.3, and 67.5 %, respectively. Anti-CCP has higher specificity and predictive values compared with the RF parameter in diagnosing RA in Iranian patients, but their discriminative values were similar. Anti-CCP and RF in combination further increases the diagnostic value for RA.

  3. The clinical significance of anti-cyclic citrullinated peptide antibody in primary Sjögren syndrome.

    PubMed

    Kim, So-Mi; Park, Eugene; Lee, Jung-Hwa; Lee, Sang-Heon; Kim, Hae-Rim

    2012-12-01

    Anti-cyclic citrullinated peptide antibody (anti-CCP) is a specific marker for the diagnosis of rheumatoid arthritis. However, this antibody can be detected in other rheumatic diseases and even in healthy people. This study aims to determine the prevalence and the clinical significance of anti-CCP in patients with primary Sjögren syndrome (pSS). We analyzed the clinical and laboratory data of 95 patients with pSS by retrospective review of their medical records. Anti-CCP was measured by ELISA kit. Anti-CCP, rheumatoid factor (RF), anti-nuclear antibody, anti-Ro and anti-La antibodies, and clinical data were investigated. We analyzed clinical and serologic characteristics of anti-CCP-positive patients. Twenty-one patients (22.1%) had positive anti-CCP (mean titer 61.6 ± 15.6 U/ml) and 40 patients (42.1%) had positive RF (mean titer 98.8 ± 22.7 IU/ml). Seventy-nine patients (83.1%) had arthralgia, and 31 patients (32.6%) had non-erosive arthritis on physical examination and radiologic images. Anti-CCP-positive patients had more frequently positive RF (71.4% vs. 41.8%, P = 0.01) and anti-Ro antibody (85.7% vs. 60.8%, P = 0.03). Anti-CCP-positive patients had non-erosive arthritis more frequently than anti-CCP-negative patients (76.1% vs. 21.6%, P < 0.01). The prevalence of anti-CCP was 22.1% in pSS, and anti-CCP was associated with non-erosive arthritis, and positivity of RF and anti-Ro antibody.

  4. [Significance and diagnostic value of synovial fluid anti-cyclic citrullinated peptide antibody and anti-mutated citrullinated vimentin antibodies in patients with serum negative rheumatoid arthritis].

    PubMed

    Qu, S J; Ye, H; Jia, R L; Li, Z G

    2016-12-18

    To explore the significance of synovial fluid (SF) anti-cyclic citrullinated peptide (CCP) antibodies and anti-mutated citrullinated vimentin (MCV) antibodies in the diagnosis of serum negative rheumatoid arthritis (SNRA). Enzyme linked immunosorbent assay (ELISA) method was apllied in the detection of two groups of patients with knee joint fluid resistance against CCP antibody and antibody of MCV, the experimental group to SNRA patients, a total of 29 cases, and the control for patients with osteoarthritis (OA), a total of 28 cases, and clinical manifestations and laboratory parameters of the two groups were collected. The positive rate of synovial fluid anti-CCP was 34.5% in the SNRA patients, which was significantly higher than 10.7% in the control patients(χ(2)=4.571, P<0.05). The positive rate of synovial fluid anti-MCV was 20.7% in the SNRA patients, which was significantly higher than 7.1% in the control patients(χ(2)=2.167, P>0.05). The SNRA patients of SF anti-CCP and anti-MCV positive had no significant difference from the SNRA patients of SF anti-CCP and anti-MCV negative in age, course and morning stiffness. The levels of erythrocyte sedimentation rate (ESR), C-reactive protein(CRP) and DAS28 scores in the SF anti-CCP positive patients were higher than those of the SF anti-CCP negative patients. The levels of ESR, CRP and DAS28 scores in the SF anti-MCV positive patients were higher than those of the SF anti-MCV negative patients, (all P<0.01). SF anti-CCP had correlation with ESR, CRP(r=0.567, P<0.01; r=0.664, P<0.01). SF anti-MCV had correlation with ESR, CRP (r=0.344, P<0.01; r=0.749, P<0.01). SF anti-CCP and anti-MCV are helpful for the diagnosis of SNRA and judgement of SNRA activity.

  5. Association of anti-modified citrullinated vimentin with subclinical atherosclerosis in early rheumatoid arthritis compared with anti-cyclic citrullinated peptide.

    PubMed

    El-Barbary, Amal M; Kassem, Elham M; El-Sergany, Mervat A S; Essa, Salwa A-M; Eltomey, Mohamed A

    2011-05-01

    To investigate anti-modified citrullinated vimentin (anti-MCV) in early rheumatoid arthritis (RA), including correlation with disease activity and cardiovascular risk factors, compared with anti-cyclic citrullinated peptides (anti-CCP3). Anti-MCV and anti-CCP3 concentrations were measured in 100 patients with early RA and 100 healthy controls at baseline to determine sensitivity and specificity. Patients received methotrexate (MTX) 0.2 mg/kg/week plus prednisone 10 mg/day. Anti-MCV, anti-CCP3, rheumatoid factor (RF), Disease Activity Score for 28 joints (DAS-28), lipid profile, erythrocyte sedimentation rate (ESR), high-sensitivity C-reactive protein assay (hsCRP), homeostasis model assessment for insulin resistance (HOMA-IR) index, tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and carotid intima-media thickness (cIMT) were measured before and after 12 months of treatment. The sensitivity and specificity for anti-MCV antibody were 75% and 90%, respectively, and for anti-CCP3 antibody 71% and 96%. Serum anti-MCV and serum anti-CCP3 levels at baseline were positively correlated with hsCRP, IL-6, HOMA-IR index, serum RF levels (p < 0.001), and cIMT (p < 0.05). Serum anti-MCV was positively correlated with serum anti-CCP3 levels. There were significant positive correlations between the percentage of changes of anti-MCV levels versus changes in DAS-28, ESR, hsCRP, atherogenic ratios (TC/HDL-C and LDL-C/HDL-C), apolipoprotein A-I, IL-6, TNF-α, HOMA-IR index, and cIMT. These correlations were not found between changes in anti-CCP3 levels compared to clinical, laboratory, and radiological variables. Anti-MCV was as sensitive as anti-CCP3 in diagnosing early RA. Anti-MCV testing appears to be useful for monitoring associated subclinical atherosclerosis in early RA.

  6. A distinct multicytokine profile is associated with anti-cyclical citrullinated peptide antibodies in patients with early untreated inflammatory arthritis.

    PubMed

    Hitchon, Carol A; Alex, Philip; Erdile, Lawrence B; Frank, Mark B; Dozmorov, Igor; Tang, Yuhong; Wong, Keng; Centola, Michael; El-Gabalawy, Hani S

    2004-12-01

    Early inflammatory arthritis is clinically heterogenous and biologically-based indicators are needed to distinguish severe from self-limited disease. Anti-cyclical citrullinated peptides (CCP) have been identified as potential prognostic markers in early arthritis cohorts. Since cytokine networks are known to play a critical role in the pathogenesis of rheumatoid arthritis (RA) and other forms of inflammatory arthritis, a panel of pro- and antiinflammatory cytokines was measured to identify biologically-based subsets of early arthritis, relating cytokine profiles to clinical measures and to the presence of RA-associated autoantibodies. Plasma concentrations of cytokines [interleukin 1beta (IL-1beta), IL-2, IL-4, IL-5, IL-6, IL-7, CXCL8 (IL-8), IL-10, IL-12p70, IL-13, IL-17, granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), interferon-g (IFN-g), CCL2 (monocyte chemoattractant protein-1, MCP-1), CCL4 (MIP-1beta), and tumor necrosis factor-a (TNF-a)] were measured in patients with early, untreated inflammatory arthritis [symptom duration < or = 12 months; > or = 1 swollen joint; RA, n = 41; undifferentiated arthritis (UA), n = 23]. Cytokine expression patterns were determined using cluster analysis. Both pro- and antiinflammatory cytokines were elevated in patients over controls (n = 21). RA clustered into subgroups based solely on cytokine profiles. The "mild" RA subgroup (n = 23) had higher CCL4 (MIP-1beta), CXCL8 (IL-8), IL-2, IL-12, IL-17, IL-5, and IL-10 levels, lower IL-6, IFN-g, GM-CSF, and IL-4 levels, less CCP positivity (52% vs 82%; p < 0.05), and lower CCP titers [71 (78) vs 153 (94); p < 0.01], but similar erythrocyte sedimentation rate, C-reactive protein, and joint counts compared to the "severe" RA groups. CCL4 (MIP-1beta), IL-13, IL-12, TNF-a, and IL-4 best distinguished the groups. Combining UA with RA samples preserved cytokine subgroups and strengthened the autoantibody associations. Fewer UA

  7. Anti-cyclic citrullinated peptide antibodies in psoriatic arthritis – cross-sectional study and literature review

    PubMed Central

    Popescu, C; Zofotă, S; Bojincă, V; Ionescu, R

    2013-01-01

    Abstract Rationale: Anti-CCP antibodies are detectable not only in rheumatoid arthritis (RA), but also in psoriatic arthritis (PsA). It is possible those anti-CCP antibodies are associated with features of PsA and that these auto-antibodies are useful in distinguishing PsA from RA. Objective: to evaluate the prevalence and the associations of anti-CCP antibodies in PsA patients; to evaluate the usefulness of anti-CCP antibodies in distinguishing PsA from RA. Methods and Results: The inquiry was designed as a cross-sectional study of 41 PsA patients, 139 RA patients and 147 normal subjects, which recorded demographic data, disease activity and serology: rheumatoid factor (RF), anti-CCP antibodies. Five PsA patients (12.2%) were anti-CCP positive. Compared to anti-CCP negative PsA patients, anti-CCP positive PsA patients had a more frequently a polyarticular disease pattern (p = 0.005), they were more frequently treated with biologics (p = 0.015) and less frequently with classic disease-modifying drugs (p < 0.001). An optimal positive cutoff value for anti-CCP titer was determined (11.6 U/mL), over which it is highly probable that a known PsA patient actually has RA and psoriasis. Discussion: The more aggressive the disease of anti-CCP positive PsA patients indicates the need of a more intensive management regarding anti-rheumatic treatment and follow-up. Anti-CCP antibodies can be a useful tool in differentiating PsA from RA, especially in RA-like forms of PsA, which present no elements pertaining to spondyloarthropathies. Abbreviations: anti-CCP - anti-cyclic citrullinated peptide antibodies; ACR - America College of Rheumatology; CRP - C-reactive protein; CASPAR - The Classification Criteria for Psoriatic Arthritis; DMARD – disease modifying anti-rheumatic drug; EULAR - European League against Rheumatism; ELISA - enzyme-linked immunosorbent assay; ESR - erythrocyte sedimentation rate; HLA – human leukocyte antigen; PsA - psoriatic arthritis; RA - rheumatoid

  8. Long-term stability of anti-cyclic citrullinated peptide antibody status in patients with early inflammatory polyarthritis.

    PubMed

    Burr, Marian L; Viatte, Sebastien; Bukhari, Marwan; Plant, Darren; Symmons, Deborah P; Thomson, Wendy; Barton, Anne

    2012-05-09

    The utility of reassessing anti-cyclic citrullinated peptide (anti-CCP) antibody status later in disease in patients presenting with early undifferentiated inflammatory polyarthritis, particularly in those who test negative for both anti-CCP and rheumatoid factor (RF) at baseline, remains unclear. We aimed therefore to determine the stability of CCP antibody status over time and the prognostic utility of repeated testing in subjects with early inflammatory polyarthritis (IP). Anti-CCP and RF were measured at baseline and 5 years in 640 IP patients from the Norfolk Arthritis Register, a primary care-based inception cohort. The relation between change in anti-CCP status/titer and the presence of radiologic erosions, the extent of the Larsen score, and Health Assessment Questionnaire (HAQ) score by 5 years was investigated. With a cut-off of 5 U/ml, 28% subjects tested positive for anti-CCP antibodies, 29% for RF, and 21% for both at baseline. Nine (2%) anti-CCP-negative patients seroconverted to positive, and nine (4.6%) anti-CCP-positive individuals became negative between baseline and 5 years. In contrast, RF status changed in 17% of subjects. However, change in RF status was strongly linked to baseline anti-CCP status and was not independently associated with outcome. Ever positivity for anti-CCP antibodies by 5 years did not improve prediction of radiographic damage compared with baseline status alone (accuracy, 75% versus 74%). A higher baseline anti-CCP titer (but not change in anti-CCP titer) predicted worse radiologic damage at 5 years (P < 0.0001), even at levels below the cut-off for anti-CCP positivity. Thus, a titer of 2 to 5 U/ml was strongly associated with erosions by 5 years (odds ratio, 3.6 (1.5 to 8.3); P = 0.003). Repeated testing of anti-CCP antibodies or RF in patients with IP does not improve prognostic value and should not be recommended in routine clinical practice.

  9. Enhanced neutrophil phagocytic capacity in rheumatoid arthritis related to the autoantibodies rheumatoid factor and anti-cyclic citrullinated peptides.

    PubMed

    de Siqueira, Marcelo Bogliolo Piancastelli; da Mota, Licia Maria Henrique; Couto, Shirley Claudino Pereira; Muniz-Junqueira, Maria Imaculada

    2015-06-30

    There is no consensus on the mechanisms by which anti-cyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) influence the pathogenesis of rheumatoid arthritis (RA). The current study verified if the presence of RF or anti-CCP is associated with phagocytic capacity and reactive oxygen species (ROS) production by phagocytes in RA patients to better clarify the role played by these antibodies in pathogenesis of the disease. A cohort of 30 RA patients followed from early stages of the disease were characterized by positivity for RF or anti-CCP, disease activity score (DAS-28), health assessment questionnaire (HAQ), use of synthetic or biologic therapy, lifestyle, comorbidities and radiographic erosions. Phagocytic capacity against Saccharomyces cerevisiae and superoxide anion production were assessed in RA patients and compared with 20 healthy controls. Phagocytic capacity and superoxide anion production were also compared between RF- and anti-CCP-positive and -negative RA patients. Anti-CCP- and RF-positive RA patients had higher neutrophil phagocytic capacity than anti-CCP- (p = 0.005) and RF (p = 0.005)-negative individuals through pattern-recognition receptors. As assessed via pattern recognition or opsonin receptors, neutrophils and monocytes from RA patients presented overall higher phagocytic capacity than neutrophils and monocytes from healthy controls (p < 0.05). Furthermore, RA patients also showed a higher capacity for producing cytotoxic oxygen radicals (p = 0.0026). Phagocytosis and superoxide anion production did not correlate with any of the clinical variables analyzed in this study. This study showed increased phagocytosis by neutrophils in RA patients who were positive for anti-CCP and RF autoantibodies. Furthermore, there was an overall hyperactivation of the phagocytes in RA patients. Our data suggest that anti-CCP and RF may indirectly enhance the inflammation cascade involving neutrophils and may indirectly

  10. Rheumatoid Arthritis, Anti-Cyclic Citrullinated Peptide Positivity, and Cardiovascular Disease Risk in the Women's Health Initiative.

    PubMed

    Mackey, Rachel H; Kuller, Lewis H; Deane, Kevin D; Walitt, Brian T; Chang, Yue-Fang; Holers, V Michael; Robinson, William H; Tracy, Russell P; Hlatky, Mark A; Eaton, Charles B; Liu, Simin; Freiberg, Matthew S; Talabi, Mehret Birru; Schelbert, Erik B; Moreland, Larry W

    2015-09-01

    To evaluate the incidence of cardiovascular disease (CVD) morbidity and mortality over the course of 10 years among the more than 160,000 postmenopausal women in the Women's Health Initiative (WHI) in relation to self-reported rheumatoid arthritis (RA), taking disease-modifying antirheumatic drugs (DMARDs), anti-cyclic citrullinated peptide (anti-CCP) positivity, rheumatoid factor (RF) positivity, CVD risk factors, joint pain, and inflammation (white blood cell count and interleukin-6 levels). Anti-CCP and RF were measured in a sample of WHI participants with self-reported RA (n = 9,988). RA was classified as self-reported RA plus anti-CCP positivity and/or taking DMARDs. Anti-CCP-negative women with self-reported RA and not taking DMARDs were classified as having "unverified RA." Age-adjusted rates of coronary heart disease (CHD), stroke, CVD, fatal CVD, and total mortality were higher in women with RA than in women with no reported RA, with multivariable-adjusted hazard ratios of 1.46 (95% confidence interval [95% CI] 1.17-1.83) for CHD and 2.55 (95% CI 1.86-3.51) for fatal CVD. Among women with RA, anti-CCP positivity and RF positivity were not significantly associated with higher risk of any outcomes, despite slightly higher risk of death for those who were anti-CCP positive than for those who were anti-CCP negative. Joint pain severity and CVD risk factors were strongly associated with CVD risk, even in women with no reported RA. CVD incidence was increased in women with RA versus women with no reported RA at almost all risk factor levels, except for low levels of joint pain or inflammation. Among women with RA, inflammation was more strongly associated with fatal CVD and total mortality than with CHD or CVD. Among postmenopausal women, RA was associated with 1.5-2.5-fold higher CVD risk. CVD risk was strongly associated with CVD risk factors, joint pain severity, and inflammation, but not with anti-CCP positivity or RF positivity. © 2015, American

  11. [Anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis: relation with clinical features, cytokines and HLA-DRB1].

    PubMed

    Correa, Paula A; Tobón, Gabriel J; Citera, Gustavo; Cadena, José; Schneeberger, Emilce; Camargo, José F; Maldonado-Cocco, José A; Anaya, Juan Manuel

    2004-06-01

    The specificity and sensitivity of anti-cyclic citrullinated peptide antibodies (anti-CCP) was examined in Latin-American patients with rheumatoid arthritis (RA). The variables considered included: 1) relation with the activity of disease, 2) extra-articular manifestations (EAM), 3) synthesis of cytokines (IL-4, IL-10, IL-12, TNF-alpha, and IFN-gamma) and IgM and IgA rheumatoid factor (RF), and 4) the association with HLA-DRB1 polymorphism. Seventy-nine RA patients were assessed (69 with established RA, and 10 with recent-onset RA not receiving any treatment), 56 with ankylosing spondylitis (AS), 25 with systemic lupus erythematosus (SLE), 50 with primary Sjögren's syndrome (pSS), and 10 healthy individuals. Of the 69 patients with established RA, 36 were reexamined 2 years later. The activity of the RA was measured by criteria adopted by the American College of Rheumatology. Anti-CCP2, RF and cytokines levels were determined by ELISA. HLA genotypes were established by first, PCR sequence amplification using sequence-specific primers and then, complete sequencing of the product. Anti-CCP antibodies were observed in 96% of patients with RA during the first evaluation and in 86% at the second evaluation (p = 0.12). No significant change in antibody titre was observed between the two evaluations (131 +/- 58.7 and 130.6 +/- 67.1 IU, respectively). The overall sensitivity and specificity was 94% and 92%, respectively; however, at titres > 60 IU, the values were 84% and 95%, respectively. The anti-CCP likelihood ratio positive test was 12 and the likelihood ratio negative test was 0.06. The positive predictive value was 87%, and the negative predictive value was 96%. Anti-CCP antibodies were observed in 12% of SLE and pSS patients, in 2% of AS patients, and in 10% of healthy controls. In RA patients, these antibodies were not associated with the activity of disease, EAM or HLA-DRB1 alleles; no significant correlation was observed between antibody titre and cytokines

  12. Anti-Cyclic Citrullinated Peptide Frequency in Patients with Chronic Hepatitis C Virus Infection and Effect of Presence of Systemic Disease

    PubMed Central

    Albayrak, Ayse; Dursun, Hakan; Uyanik, Muhammet Hamidullah; Cerrah, Serkan

    2012-01-01

    Objective: Patients with chronic hepatitis C virus (HCV) infection may show a variety of rheumatic symptoms and signs. Anti-cyclic citrullinated peptide (anti-CCP) is widely used as as a marker, particularly for rheumatoid arthritis (RA), and may be positive in some diseases that also cause arthritis, such as systemic lupus erythematosus, familial Mediterranean fever, Behçet’s disease, and psoriatic arthritis. Materials and Methods: Blood samples were obtained (in routine protocols) from 57 patients with chronic HCV infection from the Gastroenterology Clinic of Ataturk University and Infectious Disease Clinic of Erzurum Region Research and Education Hospital. Normal sera were obtained from volunteer blood donors at Ataturk University. Results: Anti-CCP antibodies were found in 5 chronic HCV patients with RA. The patient with the highest anti-CCP antibody level had RA. No patient in the control group was positive for anti-CCP antibodies. Conclusion: Anti-cyclic citrullinated peptide (anti-CCP) antibodies should be measured frequently in patients with HCV and an additional systemic disease, such as end-stage chronic renal failure, chronic obstructive airway disease, and decompensated liver cirrhosis, to differentiate RA from non-RA arthropathy. PMID:25610226

  13. Anti-cyclic citrullinated Peptide frequency in patients with chronic hepatitis C virus infection and effect of presence of systemic disease.

    PubMed

    Albayrak, Ayse; Dursun, Hakan; Uyanik, Muhammet Hamidullah; Cerrah, Serkan

    2012-12-01

    Patients with chronic hepatitis C virus (HCV) infection may show a variety of rheumatic symptoms and signs. Anti-cyclic citrullinated peptide (anti-CCP) is widely used as as a marker, particularly for rheumatoid arthritis (RA), and may be positive in some diseases that also cause arthritis, such as systemic lupus erythematosus, familial Mediterranean fever, Behçet's disease, and psoriatic arthritis. Blood samples were obtained (in routine protocols) from 57 patients with chronic HCV infection from the Gastroenterology Clinic of Ataturk University and Infectious Disease Clinic of Erzurum Region Research and Education Hospital. Normal sera were obtained from volunteer blood donors at Ataturk University. Anti-CCP antibodies were found in 5 chronic HCV patients with RA. The patient with the highest anti-CCP antibody level had RA. No patient in the control group was positive for anti-CCP antibodies. Anti-cyclic citrullinated peptide (anti-CCP) antibodies should be measured frequently in patients with HCV and an additional systemic disease, such as end-stage chronic renal failure, chronic obstructive airway disease, and decompensated liver cirrhosis, to differentiate RA from non-RA arthropathy.

  14. Diagnostic value of anti-mutated citrullinated vimentin in comparison to anti-cyclic citrullinated peptide and anti-viral citrullinated peptide 2 antibodies in rheumatoid arthritis: an Italian multicentric study and review of the literature.

    PubMed

    Bartoloni, Elena; Alunno, Alessia; Bistoni, Onelia; Bizzaro, Nicola; Migliorini, Paola; Morozzi, Gabriella; Doria, Andrea; Mathieu, Alessandro; Lotzniker, Milvia; Allegri, Flavio; Riccieri, Valeria; Alpini, Claudia; Gabrielli, Armando; Tampoia, Marilina; Gerli, Roberto

    2012-09-01

    In the last years, the detection of antibodies (Abs) against citrullinated peptides (ACPA) has largely replaced rheumatoid factor (RF) as the most helpful biomarker in the diagnosis of rheumatoid arthritis (RA). Current assays detect ACPA reactivity with epitopes on various different citrullinated proteins. Among these, anti-cyclic citrullinated peptide (CCP) Abs have been widely demonstrated to be an important diagnostic and prognostic tool because of their high specificity. Recently, citrullinated vimentin, a protein highly released in synovial microenvironment, has been identified as potential autoantigen in the pathophysiology of RA and an enzyme-linked immunosorbent assay (ELISA) for the detection of Abs directed against a mutated citrullinated vimentin (anti-MCV) was developed. Several recent studies evaluating the characteristics of anti-MCV in comparison to anti-CCP Abs, have given conflicting results. Anti-MCV have been demonstrated to perform better than anti-CCP as predictor of radiographic damage. Conversely, its additional diagnostic and prognostic role in comparison to anti-CCP in both early and established RA is controversial. Aim of this study was to evaluate the diagnostic performance of anti-MCV in RA and to compare it to anti-CCP and the recently developed assay targeting viral citrullinated peptide 2 (VCP2) in a large cohort of RA patients (n=285), healthy subjects and other disease controls (n=227). Anti-MCV resulted to have a sensitivity of 59% and a specificity of 92%. In comparison, anti-CCP and anti-VCP2 displayed a sensitivity of 77% and 61% and a specificity of 96% and 95%, respectively. Of interest, at the manufacturer recommended cutoff value of 20U/mL, a high percentage of healthy subjects as well as Epstein Barr (EBV) and hepatitis C (HCV) virus infected patients resulted anti-MCV positive. In our large cohort of RA patients, anti-MCV demonstrated lower sensitivity than anti-CCP and VCP2 test, thus not allowing to confirm previously

  15. [Prevalence and significance of immunoglobulin G-anti-cyclic citrullinated peptide antibodies in primary Sjogren's syndrome patients].

    PubMed

    Liu, Yuan; Wang, Yong-fu; Wang, Kai-li; Lv, Feng-feng

    2014-06-18

    To investigate the prevalence and significance of IgG-anti-cyclic citrullinated peptides (CCP) antibody in PSS patients. A total of 120 patients diagnosed with PSS were investigated in the first affiliated hospital of Baotou Medical College from March 2006 to December 2009. IgG-anti-CCP antibody was assayed by enzyme-linked immunosorbent assay (ELISA), also anti-Sjogren's syndrome type A (SSA) and Sjogren's syndrome type B (SSB) antibody were assayed by immunoblotting. Erythrocyte sedimentation rate (ESR) was assayed by westergren in serum, and C reactive protein (CRP), IgA, IgM, IgG and IgM-RF were detected by immune turbidimetric. At the same time, clinical symptoms and involvement of important organs were observed. Following up the patients above 3 years, the primary Sjogren's syndrome (PSS) patients who had progressed to rheumatoid arthritis (RA) were evaluated. The positive rate of anti-CCP antibody in the PSS patients was 19.17%; After 3 years, more patients who were positive for anti-CCP antibody had progressed to RA (χ² = 5.015,P=0.022) than the patients in negative group; The patients in anti-CCP antibody positive group were more prone to joint involvement (χ² = 8.058,P<0.05), more swollen joints (U=152.00, P<0.05) and longer morning stiffness (U=100.00, P<0.05) than the patients with negative anti-CCP antibody, but the involvement of vital organs in the two groups had no significant difference (χ² = 0.208,0.099,0.000 and 0.122, P>0.05); The positive rate of anti-SSA and SSB antibody in anti-CCP antibody positive group and negative group had no significant difference (χ² = 0.008 and 0.56, P>0.05); Multiple linear regression showed that the level of anti-CCP antibody was positively correlated with IgM-RF levels in the PSS patients (B=0.61, 95% CI=0.36-0.86, P<0.05), but had no significant correlation with ESR, CRP, IgA, IgM and IgG levels (P>0.05).There were no significant differences in the level of ESR, CRP, IgA, IgM and IgG between anti

  16. Anti-cyclic citrullinated peptide antibody (anti-CCP antibody) is present in the sera of patients with dementia of Alzheimer's type in Asian.

    PubMed

    Satoh, K; Kawakami, A; Shirabe, S; Tamai, M; Sato, A; Tsujihata, M; Nagasato, K; Eguchi, K

    2010-05-01

    In the hippocampi of Alzheimer's disease (AD) patients, aberrant expression of citrullinated proteins and peptidylarginase 2 (PADI2) has been identified. We explored the functional roles of these proteins by means of detection of serum anti-cyclic citrullinated peptide antibody (anti-CCP antibody) in patients with dementia of Alzheimer's type (DAT). Sera were obtained from 42 patients with DAT, 30 patients with other neurological disorders and 42 healthy controls. Gender ratio and age were comparable among the three groups. The level of anti-CCP antibody in sera was examined by ELISA. Anti-CCP antibody was not found in the 30 patients with other neurological disorders, and only one of the 42 healthy controls (2.4%) was positive. However, surprisingly, anti-CCP antibody was clearly detected in eight of the 42 DAT patients. Anti-CCP antibody appears to be a simple and early serologic biomarker for DAT among dementia patients. Additionally, our data imply that citrullinated proteins accumulated in the astrocytes of AD patients acquire neo-antigenicity, inducing anti-CCP antibody production.

  17. Polymorphisms and functional haplotype in PADI4: further evidence for contribution on rheumatoid arthritis susceptibility and anti-cyclic citrullinated peptide antibodies in a western Mexican population.

    PubMed

    Guzmán-Guzmán, Iris Paola; Reyes-Castillo, Zyanya; Muñoz-Barrios, Salvador; Ruiz-Noa, Yeniley; Martínez-Bonilla, Gloria Esther; Parra-Rojas, Isela; Palafox-Sánchez, Claudia Azucena; Muñoz-Valle, José Francisco

    2015-02-01

    Peptidyl arginine deiminase IV (PADI4) enzyme catalyzes the citrullination of proteins, which are recognized by anti-cyclic citrullinated peptide antibodies (anti-CCP) in rheumatoid arthritis (RA) patients. Here, we determined the association between PADI4 gene polymorphisms and haplotypes with RA susceptibility and clinical characteristics in a western Mexican population. The relationship of PADI4 polymorphisms with anti-CCP and PADI4 mRNA expression was also evaluated. PADI4_89, PADI4_90 and PADI4_92 polymorphisms were individually associated with RA susceptibility. The GTG haplotype was significantly associated with: RA susceptibility; disease onset at ≤ 40 years and anti-CCP antibodies. PADI4 expression was three fold higher in RA patients carrying the susceptibility haplotype (GTG) than in non-susceptibility haplotype carriers (ACC). In conclusion, polymorphisms and functional haplotype (GTG) in PADI4 are associated with RA susceptibility as well as anti-CCP antibodies in a Mexican population. This supports the role of PADI4 early in RA pathogenesis by promoting the generation of citrullinated autoantigens. Copyright © 2014 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  18. High levels of anti-cyclic citrullinated peptide autoantibodies are associated with co-occurrence of pulmonary diseases with rheumatoid arthritis.

    PubMed

    Aubart, Fleur; Crestani, Bruno; Nicaise-Roland, Pascale; Tubach, Florence; Bollet, Caroline; Dawidowicz, Karen; Quintin, Emilie; Hayem, Gilles; Palazzo, Elisabeth; Meyer, Olivier; Chollet-Martin, Sylvie; Dieudé, Philippe

    2011-06-01

    To investigate whether levels of anti-cyclic citrullinated peptide antibodies (anti-CCP2) in patients with rheumatoid arthritis (RA) are associated with the co-occurrence of lung diseases. A total of 252 RA patients were included in a cross-sectional study. Pulmonary disease was confirmed by high-resolution chest computed tomography scan. Circulating anti-CCP2 were quantified using ELISA. Multivariate logistic regression was conducted to identify independent risk factors for lung disease. Male sex (OR 3.29, 95% CI 1.59-6.80) and high anti-CCP2 levels (OR 1.49, 95% CI 1.25-1.78) were identified as independent risk factors for lung disease in the RA population. High anti-CCP2 levels are associated with lung disease in the RA population.

  19. Greater prevalence of seropositivity for anti-cyclic citrullinated peptide antibody in unaffected first-degree relatives in multicase rheumatoid arthritis-affected families

    PubMed Central

    Kim, Seong-Kyu; Bae, Jisuk; Lee, Hwajeong; Kim, Ji Hun; Park, Sung-Hoon

    2013-01-01

    Background/Aims This study determined the prevalence and determinants of seropositivity for rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) antibody, and anti-mutated citrullinated vimentin (anti-MCV) antibody in unaffected first-degree relatives (FDRs) of rheumatoid arthritis (RA) patients. Methods A total of 337 subjects (135 with RA and 202 FDRs) were enrolled in this case-control study. Serum RF, anti-CCP antibody, and anti-MCV antibody were assayed. Subjects in multicase families (≥ 2 affected FDRs within the same family) were identified. Multivariate logistic regression analysis was used to identify risk factors associated with RA-related autoantibodies. Results Seropositivity for RF, anti-CCP antibody, or anti-MCV antibody was detected in 14.4%, 5.0%, or 13.4% of unaffected FDRs, respectively. Anti-CCP antibody seropositivity was more prevalent in FDRs in multicase families (17.8%) than in those not in multicase families (1.3%, p < 0.0001). Significant correlations between RA-associated autoantibodies were detected in the FDR group (between RF and anti-CCP antibody: r = 0.366, p < 0.0001; between RF and anti-MCV antibody: r = 0.343, p < 0.0001; and between anti-CCP antibody and anti-MCV antibody: r = 0.849, p < 0.0001). After adjustment for age and sex, anti-CCP antibody seropositivity in FDRs was significantly associated with being in a multicase family (odds ratio, 49.8; 95% confidence interval, 5.6 to 441.6). Conclusions The association between anti-CCP antibody seropositivity in unaffected FDRs and being in a multicase family suggests that genetic and/or environmental factors may increase the risk for RA development in unaffected FDRs. PMID:23345996

  20. Serum leptin and serum leptin/serum leptin receptor ratio imbalance in obese rheumatoid arthritis patients positive for anti-cyclic citrullinated peptide antibodies.

    PubMed

    Gómez-Bañuelos, Eduardo; Navarro-Hernández, Rosa Elena; Corona-Meraz, Fernanda; Madrigal-Ruíz, Perla Monserrat; Martín-Marquez, Beatríz Teresita; Pizano-Martinez, Oscar Enrique; Aguilar-Arreola, Jorge; Perez-Cruz, Paul Jacob; Macias-Reyes, Hector; Gonzalez-Lopez, Laura; Gamez-Nava, Jorge Ivan; Salazar-Páramo, Mario; Vazquez-del Mercado, Monica

    2015-11-20

    Leptin has a prominent role in the development and maintenance of acute and chronic inflammatory states such as rheumatoid arthritis (RA) and obesity. Nevertheless, the association of serum leptin (sLep) and soluble leptin receptor (sLepR) in RA pathogenesis has not been clarified. The purpose of this study was to evaluate the association of sLep, sLepR and leptin production indexes such as sLep/fat mass ratio with clinical activity and biomarkers and anti-cyclic citrullinated peptide (anti-CCP) antibodies in RA compared with body mass index (BMI) matched control subjects. We included 64 RA patients and 66 controls matched for age, gender and BMI. Subjects were evaluated for BMI, fat mass distribution, sLep, sLepR, sLep/fat mass ratio and sLepR/fat mass ratio. Patients were evaluated for clinical activity and anti-CCP antibodies. We found two or three fold increased sLep levels, sLep/sLepR ratio and sLep/fat mass ratio in obese anti-CCP positive RA patients vs. Partial correlations showed that anti-CCP antibodies were correlated with sLep/fat mass ratio (partial r = 0.347, P = 0.033) after adjustment for age, subcutaneous adipose tissue and fat mass. In preobese and obese RA patients there is and increased production of sLep according to anti-CCP positivity. This phenomenon suggests there is an additive effect of chronic inflammation resulting from RA and obesity in which leptin favors the humoral response against citrullinated proteins. In summary, the data observed in our study suggests sLep could be a surrogate marker of chronicity and humoral immunity in RA in the presence of obesity.

  1. Greater prevalence of seropositivity for anti-cyclic citrullinated peptide antibody in unaffected first-degree relatives in multicase rheumatoid arthritis-affected families.

    PubMed

    Kim, Seong-Kyu; Bae, Jisuk; Lee, Hwajeong; Kim, Ji Hun; Park, Sung-Hoon; Choe, Jung-Yoon

    2013-01-01

    This study determined the prevalence and determinants of seropositivity for rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) antibody, and anti-mutated citrullinated vimentin (anti-MCV) antibody in unaffected first-degree relatives (FDRs) of rheumatoid arthritis (RA) patients. A total of 337 subjects (135 with RA and 202 FDRs) were enrolled in this case-control study. Serum RF, anti-CCP antibody, and anti-MCV antibody were assayed. Subjects in multicase families (≥ 2 affected FDRs within the same family) were identified. Multivariate logistic regression analysis was used to identify risk factors associated with RA-related autoantibodies. Seropositivity for RF, anti-CCP antibody, or anti-MCV antibody was detected in 14.4%, 5.0%, or 13.4% of unaffected FDRs, respectively. Anti-CCP antibody seropositivity was more prevalent in FDRs in multicase families (17.8%) than in those not in multicase families (1.3%, p < 0.0001). Significant correlations between RA-associated autoantibodies were detected in the FDR group (between RF and anti-CCP antibody: r = 0.366, p < 0.0001; between RF and anti-MCV antibody: r = 0.343, p < 0.0001; and between anti-CCP antibody and anti-MCV antibody: r = 0.849, p < 0.0001). After adjustment for age and sex, anti-CCP antibody seropositivity in FDRs was significantly associated with being in a multicase family (odds ratio, 49.8; 95% confidence interval, 5.6 to 441.6). The association between anti-CCP antibody seropositivity in unaffected FDRs and being in a multicase family suggests that genetic and/or environmental factors may increase the risk for RA development in unaffected FDRs.

  2. Anti-cyclic citrullinated peptide (CCP) antibody in patients with wood-smoke-induced chronic obstructive pulmonary disease (COPD) without rheumatoid arthritis.

    PubMed

    Sigari, Naseh; Moghimi, Nasrin; Shahraki, Farhad Saber; Mohammadi, Shilan; Roshani, Daem

    2015-01-01

    Citrullination, a post-translational modification of proteins, is increased in inflammatory processes and is known to occur in smokers. It can induce anti-cyclic citrullinated peptide (CCP) antibodies, the most specific serologic marker for rheumatoid arthritis. Thus far, the incidence of autoimmunity in patients with wood-smoke-induced chronic obstructive pulmonary disease (COPD) resulting in anti-CCP production has not been examined. We hypothesise that anti-CCP antibody level in these patients should be higher than that in healthy subjects. A total of 112 non-rheumatoid arthritis patients, including 56 patients with wood-smoke-induced COPD and 56 patients with tobacco-induced COPD, and 56 healthy non-smoker controls were included. The serum anti-CCP antibody levels were measured and compared between the groups and against smoke exposure and clinical characteristics. The mean anti-CCP antibody levels in wood-smoke-induced COPD group were significantly higher than those in tobacco-induced COPD group (p = 0.03) and controls (p = 0.004). Furthermore, 8 (14.2 %) patients with wood-smoke-induced COPD, 4 (7.14 %) with tobacco-induced COPD and 2 (3.57 %) controls exceeded the conventional cut-off of anti-CCP antibody positivity. No relationship was found between the anti-CCP antibody level and age, gender, duration of disease, Pack-years of smoking, and duration of exposure to wood smoke. Moreover, correlations between anti-CCP antibodies and severity of airflow limitation, CAT scores, mMRC scores of dyspnoea, and GOLD staging of COPD severity were not significant. Wood-smoke-induced COPD could significantly increase the anti-CCP antibody level in non-rheumatoid arthritis patients when compared with that in patients with tobacco-induced COPD and healthy controls.

  3. Decrease of anti-cyclic citrullinated peptide antibodies and rheumatoid factor following anti-TNFα therapy (infliximab) in rheumatoid arthritis is associated with clinical improvement

    PubMed Central

    Alessandri, C; Bombardieri, M; Papa, N; Cinquini, M; Magrini, L; Tincani, A; Valesini, G

    2004-01-01

    Objective: To investigate the effect of infliximab treatment on anti-cyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) in patients with rheumatoid arthritis. Methods: 43 patients with rheumatoid arthritis not responding to disease modifying anti-rheumatic drugs (DMARD) received intravenous infliximab at a dose of 3 mg/kg at baseline and after two and six weeks, and subsequently bimonthly, in combination with methotrexate. Serum samples were collected at baseline and at week 24. A commercial enzyme linked immunosorbent assay was used to test for anti-CCP antibodies; RF were detected using a quantitative nephelometric assay. Results: At baseline, 38 of the 43 patients (88%) were positive for anti-CCP antibodies, and 41 (95%) were positive for RF. The serum titre of anti-CCP and RF decreased significantly after six months of treatment (p = 0.0001 and p<0.0001, respectively). When the patients were grouped on the basis of their clinical response to infliximab, a significant decrease in serum anti-CCP antibodies and RF was observed only in patients who had clinical improvement (ACR 20 and ACR 50). Conclusions: Anti-TNFα treatment in rheumatoid arthritis results in a decrease in the serum titres of RF and anti-CCP antibodies in patients showing clinical improvement, suggesting that these measurements may be a useful adjunct in assessing treatment efficacy. PMID:15361374

  4. Anti-cyclic citrullinated peptide antibody titer predicts time to rheumatoid arthritis onset in patients with undifferentiated arthritis: results from a 2-year prospective study.

    PubMed

    Bizzaro, Nicola; Bartoloni, Elena; Morozzi, Gabriella; Manganelli, Stefania; Riccieri, Valeria; Sabatini, Paola; Filippini, Matteo; Tampoia, Marilina; Afeltra, Antonella; Sebastiani, Giandomenico; Alpini, Claudia; Bini, Vittorio; Bistoni, Onelia; Alunno, Alessia; Gerli, Roberto

    2013-01-22

    The diagnostic, predictive and prognostic role of anti-cyclic citrullinated peptide (CCP) antibodies in rheumatoid arthritis (RA) patients is widely accepted. Moreover, detection of these antibodies in subjects presenting with undifferentiated arthritis (UA) is associated with a significant risk to develop the disease. On the other hand, clinical and prognostic significance of evaluating anti-CCP levels in subjects with inflammatory arthritis at disease onset has not been fully clarified. The goal of this prospective study is to analyze the value and prognostic significance of anti-CCP titer quantification in UA subjects. Serial anti-CCP assays were measured in 192 consecutive patients presenting with UA lasting less than 12 weeks. Clinical and serological data and arthritis outcome were evaluated every 6 months until two years of follow-up. Anti-CCP positivity, at both low and high titer, and arthritis of hand joints significantly predicted RA at two years, risk increasing in subjects with high anti-CCP titers at baseline. Moreover, time to RA diagnosis was shorter in patients with high anti-CCP2 titers at enrollment with respect to those with low antibody concentration. Presence of anti-CCP antibodies, at both low and high concentration, is significantly associated with RA development in subjects with recent onset UA. However, time interval from the onset of the first symptoms to the fulfilment of the classification criteria appears to be directly related to the initial anti-CCP level.

  5. Anti-cyclic citrullinated peptide antibody titer predicts time to rheumatoid arthritis onset in patients with undifferentiated arthritis: results from a 2-year prospective study

    PubMed Central

    2013-01-01

    Introduction The diagnostic, predictive and prognostic role of anti-cyclic citrullinated peptide (CCP) antibodies in rheumatoid arthritis (RA) patients is widely accepted. Moreover, detection of these antibodies in subjects presenting with undifferentiated arthritis (UA) is associated with a significant risk to develop the disease. On the other hand, clinical and prognostic significance of evaluating anti-CCP levels in subjects with inflammatory arthritis at disease onset has not been fully clarified. The goal of this prospective study is to analyze the value and prognostic significance of anti-CCP titer quantification in UA subjects. Methods Serial anti-CCP assays were measured in 192 consecutive patients presenting with UA lasting less than 12 weeks. Clinical and serological data and arthritis outcome were evaluated every 6 months until two years of follow-up. Results Anti-CCP positivity, at both low and high titer, and arthritis of hand joints significantly predicted RA at two years, risk increasing in subjects with high anti-CCP titers at baseline. Moreover, time to RA diagnosis was shorter in patients with high anti-CCP2 titers at enrollment with respect to those with low antibody concentration. Conclusions Presence of anti-CCP antibodies, at both low and high concentration, is significantly associated with RA development in subjects with recent onset UA. However, time interval from the onset of the first symptoms to the fulfilment of the classification criteria appears to be directly related to the initial anti-CCP level. PMID:23339296

  6. A CLEC16A variant confers risk for juvenile idiopathic arthritis and anti-cyclic citrullinated peptide antibody negative rheumatoid arthritis.

    PubMed

    Skinningsrud, Beate; Lie, Benedicte A; Husebye, Eystein S; Kvien, Tore K; Førre, Øystein; Flatø, Berit; Stormyr, Alice; Joner, Geir; Njølstad, Pål R; Egeland, Thore; Undlien, Dag E

    2010-08-01

    Variants in CLEC16A have conferred susceptibility to autoimmune diseases in genome-wide association studies. The present work aimed to investigate the locus' involvements in juvenile idiopathic arthritis (JIA) and further explore the association with rheumatoid arthritis (RA), type 1 diabetes (T1D) and Addison's disease (AD) in the Norwegian population. Three single nucleotide polymorphisms (SNPs) were genotyped in patients with RA (n=809), JIA (n=509), T1D (n=1211) and AD (n=414) and in healthy controls (n=2149). All diseases were associated with CLEC16A, but with different SNPs. The intron 22 SNP, rs6498169, was associated with RA (p=0.006) and JIA (p=0.016) and the intron 19 SNPs, rs12708716/rs12917716, with T1D (p=1x10-5) and AD (p=2x10-4). The RA association was confined to the anti-cyclic citrullinated peptide antibody (anti-CCP) negative subgroup (p=2x10-4). This is the first report of a CLEC16A association with JIA and a split of the RA association according to anti-CCP status. Different causative variants underlie the rheumatic versus the organ specific diseases.

  7. Rheumatoid Factor, Anti-Cyclic Citrullinated Peptide Antibody, C-Reactive Protein, and Erythrocyte Sedimentation Rate for the Clinical Diagnosis of Rheumatoid Arthritis.

    PubMed

    Shen, Rongchun; Ren, Xiaojuan; Jing, Rongrong; Shen, Xianjuan; Chen, Jianping; Ju, Shaoqing; Yang, Chunlan

    2015-01-01

    To explore the value of rheumatoid factor (RF), anti-cyclic citrullinated peptide (CCP) antibody, C-reactive protein (CRP), and the erythrocyte sedimentation rate (ESR) in the diagnosis of rheumatoid arthritis (RA). Using rate nephelometry, chemiluminescence microparticle immunoassay (CMIA), and Westergren sedimentation rate testing, we detected RF, anti-CCP antibody, CRP, and ESR in 134 patients with RA and 50 healthy control individuals. We observed significant differences in RF, anti-CCP antibody, CRP, and ESR concentrations between the RA and control groups (P <.01). The sensitivity, specificity and accuracy in the diagnosis of RA were 91.0%, 74.4%, and 87.0%, respectively, for RF; 88.0%, 90.4%, and 88.1%, respectively, for anti-CCP antibody; and 90.2%, 83.3%, and 89.5%, respectively, for the detection of RA via the combination of RF and anti-CCP antibody. Anti-CCP is more specific than the other parameters we reviewed for the diagnosis of RA. Combined detection of the 4 parameters is beneficial when confirming a diagnosis of RA.

  8. Anti-cyclic citrullinated peptide antibody as a marker of erosive arthritis in patients with systemic lupus erythematosus: a systematic review and meta-analysis.

    PubMed

    Budhram, A; Chu, R; Rusta-Sallehy, S; Ioannidis, G; Denburg, J A; Adachi, J D; Haaland, D A

    2014-10-01

    Anti-cyclic citrullinated peptide (CCP) antibody is an established marker in the diagnosis and prognostication of rheumatoid arthritis (RA). Infrequently, systemic lupus erythematosus (SLE) patients also develop a deforming erosive arthritis, similar to that of RA. Our objective was to determine whether anti-CCP antibody is a useful marker of erosive disease in SLE patients presenting with arthritis. Electronic databases EMBASE, MEDLINE and non-indexed MEDLINE citations were searched through April 11, 2014, using the outlined key terms. Studies meeting predefined inclusion and exclusion criteria were reviewed. Two reviewers independently assessed the quality of included articles using previously described criteria. The DerSimonian-Laird random effects model was used to calculate pooled sensitivity and specificity of anti-CCP antibody for erosive arthritis in SLE. Seven articles met inclusion and exclusion criteria. A total of 609 SLE patients with arthritis were identified, 70 of whom had erosive disease. Pooled sensitivity and specificity of anti-CCP antibody for erosive arthritis was 47.8% (95% CI, 26.2%-70.2%) and 91.8% (95% CI, 78.4%-97.2%), respectively. Our findings suggest that anti-CCP antibody is a highly specific marker for erosive arthritis in SLE. Longitudinal prospective studies are needed to determine if anti-CCP antibody can be used as a predictor of erosive disease. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  9. Comparison of the second and third generation anti-cyclic citrullinated peptide antibody assays in the diagnosis of Japanese patients with rheumatoid arthritis.

    PubMed

    Shidara, Kumi; Inoue, Eisuke; Tanaka, Eiichi; Hoshi, Daisuke; Seto, Yohei; Nakajima, Ayako; Momohara, Shigeki; Taniguchi, Atsuo; Yamanaka, Hisashi

    2011-05-01

    The anti-cyclic citrullinated peptide (CCP) antibody has become increasingly important in the diagnosis of rheumatoid arthritis (RA), especially for early diagnosis. The purpose of this study is to compare the diagnostic usefulness of the second and third generation anti-CCP antibody kits among Japanese patients with RA. Anti-CCP antibody titers were measured with the second generation (MESACUP CCP test, Medical and biological laboratories) and third generation (QUANTA Lite CCP3 IgG ELISA, Inova Diagnostics) kits using serum samples from 106 rheumatoid arthritis (RA) patients and 57 non-RA patients. Sensitivities and specificities were compared. The sensitivity and specificity of the second generation anti-CCP (anti-CCP2) kit were 88.7 and 89.5%, and those of the third generation anti-CCP (anti-CCP3) kit were 91.5 and 87.7%. Area under the receiver operating curve showed that anti-CCP2 and anti-CCP3 had similar diagnostic performances. Diagnostic performance of the anti-CCP3 assay was comparable with the anti-CCP2 assay in Japanese patients with RA.

  10. [Comparison of nine second- and third-generation anti-cyclic citrullinated peptide antibody assays for the diagnosis of rheumatoid arthritis].

    PubMed

    Hayashi, Nobuhide; Kumagai, Shunichi; Onuma, Kenichiro; Uto, Kenichi; Sugiyama, Daisuke; Saegusa, Jun; Kawano, Seiji

    2013-01-01

    The aim of this study was to compare the diagnostic and analytical performances of nine anti-cyclic citrullinated peptide (CCP) antibody assays. Anti-CCP antibody titers were measured in sera from 89 patients with rheumatoid arthritis (RA), 121 with rheumatic diseases other than RA (non-RA), 47 with osteoarthritis (OA), 142 with chronic inflammatory diseases (CID) and 168 healthy subjects. Reproducibility, sensitivity, specificity, correlation and concordance rate of the nine assays were compared. Coefficients of variations of within-run and between-run reproducibility at two different concentrations for each assay ranged from 0.7 to 8.5% and from 0.6 to 8.3%, respectively. With our proposed optimal cut-off value for the third-generation assay, concordance rates were 96.8~99.6%. The range of sensitivity was 75.3~78.7% and the ranges of specificity for non-RA, OA, CID, and healthy subjects were 93.4~97.5%, 97.9%, 96.5~98.6% and 98.8~100%, respectively. However, several discrepant samples were detected and their titer levels were about 3 times higher than the normal upper limit in the 2010 RA classification criteria. Good positive correlations were observed for parts of the second-generation assay. Our study showed that each of the nine assays has good reproducibility and high diagnostic accuracy, and is thus equally useful for the diagnosis of RA.

  11. Impact of baseline anti-cyclic citrullinated peptide-2 antibody concentration on efficacy outcomes following treatment with subcutaneous abatacept or adalimumab: 2-year results from the AMPLE trial

    PubMed Central

    Sokolove, Jeremy; Schiff, Michael; Fleischmann, Roy; Weinblatt, Michael E; Connolly, Sean E; Johnsen, Alyssa; Zhu, Jin; Maldonado, Michael A; Patel, Salil; Robinson, William H

    2016-01-01

    Objectives To examine whether baseline anti-cyclic citrullinated peptide-2 (CCP2) antibody status and concentration correlated with clinical outcomes in patients treated with abatacept or adalimumab on background methotrexate (MTX) in the 2-year AMPLE (Abatacept versus adaliMumab comParison in bioLogic-naïvE rheumatoid arthritis subjects with background MTX) study. Methods In this exploratory analysis, anti-CCP2 antibody concentration was measured at baseline, and antibody-positive patients were divided into equal quartiles, Q1–Q4, representing increasing antibody concentrations. Clinical outcomes analysed by baseline anti-CCP2 status and quartile included change from baseline in disease activity and disability and remission rates. Results Baseline characteristics were generally comparable across quartiles and treatment groups. In both treatment groups, anti-CCP2 antibody-negative patients responded less well than antibody-positive patients. At year 2, improvements in disease activity and disability and remission rates were similar across Q1–Q3, but were numerically higher in Q4 in the abatacept group; in contrast, treatment effects were similar across all quartiles in the adalimumab group. Conclusions In AMPLE, baseline anti-CCP2 positivity was associated with a better response for abatacept and adalimumab. Patients with the highest baseline anti-CCP2 antibody concentrations had better clinical response with abatacept than patients with lower concentrations, an association that was not observed with adalimumab. Trial registration number NCT00929864. PMID:26359449

  12. Anti-cyclic citrullinated peptide antibodies are not frequently observed in children with type 1 diabetes mellitus: a single-center study.

    PubMed

    Yıldız, Melek; İşleten, Figen; Demir, Korcan; Çelik, Nilüfer; Korkmaz, Hüseyin Anıl; Tuğlu, Birsen; Nalbantoğlu, Özlem; Özkan, Behzat

    2016-01-01

    Type 1 diabetes mellitus (DM) and rheumatoid arthritis (RA) have been reported to occur concurrently in some cases. This study aimed to evaluate the presence of anti-cyclic citrullinated peptide (CCP) antibodies, which have been reported to have diagnostic value for RA, in children with type 1 DM. The study included 90 children with type 1 DM (Group 1) and 76 control cases (Group 2). The rates of reported family histories of RA and rheumatoid factor positivity did not differ between groups. In group 1, one case (1.1%) was positive for anti-CCP antibodies, whereas none of the controls were positive. The anti-CCP positive patient had no relevant joint complaints. Anti-CCP antibodies were rarely found in cases of pediatric type 1 DM. Thus, relevant screening in the follow-up of pediatric patients does not appear to be rational in the absence of any signs or symptoms of arthritis. The single case exhibiting a high anti-CCP level needs to be followed up for RA, although this positive result might be nonspecific and transient.

  13. Anti-cyclic citrullinated peptide and rheumatoid factor in patients with chronic hepatitis B and hepatitis B carriers

    PubMed Central

    Dalkılıç, Ediz; Öksüz, Mustafa Ferhat; Tufan, Ayşe Nur; Özbek, Aysun; Nizamoğlu, Ali; Dolarslan, Mürside Esra; Coşkun, Belkıs Nihan; Pehlivan, Yavuz

    2015-01-01

    Objective Rheumatoid factor (RF) positivity that may occur in a number of patients with hepatitis B (HBV) infection poses challenges in terms of differential diagnosis with rheumatoid arthritis (RA). On the other hand, antibodies to cyclic citrullinated peptide (anti-CCP) may prove to be an important marker for differential diagnosis of the two conditions. This study aimed to assess anti-CCP and RF positivity among patients with hepatitis B and rheumatoid arthritis. Material and Methods Anti-CCP and RF seropositivity was assessed in 61 patients with HBV infection (32 patients with chronic hepatitis, 29 patients with inactive HBV carrier status) and 40 patients with RA as the control group. Results RF positivity was found in 18.7% and 34.4% of the patients with chronic hepatitis B and inactive HBV carrier status, respectively. On the other hand, only one patient with chronic HBV had low positive anti-CCP. RF was positive in 24 (60%) and anti-CCP was positive in 26 (65%) patients among the 40 patients with RA. Conclusion Anti-CCP may be helpful in the differential diagnosis between RA and chronic HBV infection or inactive HBV carrier status. PMID:27708928

  14. Evaluation of anti-cyclic citrullinated peptide antibodies may be beneficial in RF-negative juvenile idiopathic arthritis patients.

    PubMed

    Spârchez, Mihaela; Miu, Nicolae; Bolba, Claudia; Iancu, Mihaela; Spârchez, Zeno; Rednic, Simona

    2016-03-01

    Despite the high diagnostic and prognostic performance in adult rheumatoid arthritis, the role of antibodies to cyclic citrullinated peptide (anti-CCP) in juvenile idiopathic arthritis (JIA) is controversial. Occurrence of anti-CCP was mainly seen in rheumatoid factor (RF)-positive polyarthritis patients. In the present study, our aim was to investigate the prevalence and significance of anti-CCP for subjects with JIA in our population. We evaluated anti-CCP reactivity in the sera of 70 patients with various subtypes of JIA in a prospective cohort study. Anti-CCP titres were correlated with the evolution of joint involvement and the presence of joint damage. Nine JIA patients were seropositive for anti-CCP with respect to the cut-off value of the test. In our cohort, 34 patients had a polyarticular joint disease, most of them being RF-negative (30/34, 88 %). All four RF-positive polyarthritis patients had high anti-CCP concentrations and an aggressive erosive disease. In the RF-negative JIA patients, anti-CCP reactivity was in lower titres but significantly associated with polyarticular joint involvement (p = 0.016) and also with the presence of joint damage (p < 0.001). Presence of anti-CCP, at both low and high concentration, was significantly associated with a more severe articular disease in our JIA patients. Investigating anti-CCP should clearly be taken into consideration even among patients with JIA subtypes other than RF-positive polyarthritis.

  15. Anti-Cyclic Citrullinated Peptide Antibodies and Severity of Interstitial Lung Disease in Women with Rheumatoid Arthritis

    PubMed Central

    Ponce-Guarneros, Manuel; Mejía, Mayra; Juárez-Contreras, Pablo; Corona-Sánchez, Esther Guadalupe; Rodríguez-Hernández, Tania Marlen; Salazar-Páramo, Mario; Cardona-Muñoz, Ernesto German; Celis, Alfredo; González-Lopez, Laura

    2015-01-01

    Objective. To evaluate whether serum titers of second-generation anticyclic citrullinated peptide antibodies (anti-CCP2) are associated with the severity and extent of interstitial lung disease in rheumatoid arthritis (RA-ILD). Methods. In across-sectional study, 39 RA-ILD patients confirmed by high-resolution computed tomography (HRCT) were compared with 42 RA without lung involvement (RA only). Characteristics related to RA-ILD were assessed in all of the patients and serum anti-CCP2 titers quantified. Results. Higher anti-CCP2 titers were found in RA-ILD compared with RA only (medians 77.9 versus 30.2 U/mL, P < 0.001). In the logistic regression analysis after adjustment for age, disease duration (DD), smoke exposure, disease activity, functioning, erythrocyte sedimentation rate, and methotrexate (MTX) treatment duration, the characteristics associated with RA-ILD were higher anti-CCP2 titers (P = 0.003) and + RF (P = 0.002). In multivariate linear regression, the variables associated with severity of ground-glass score were anti-CCP2 titers (P = 0.02) and with fibrosis score DD (P = 0.01), anti-CCP2 titers (P < 0.001), and MTX treatment duration (P < 0.001). Conclusions. Anti-CCP2 antibodies are markers of severity and extent of RA-ILD in HRCT. Further longitudinal studies are required to identify if higher anti-CCP2 titers are associated with worst prognosis in RA-ILD. PMID:26090479

  16. Performance of anti-cyclic citrullinated Peptide assays differs in subjects at increased risk of rheumatoid arthritis and subjects with established disease.

    PubMed

    Demoruelle, M Kristen; Parish, Mark C; Derber, Lezlie A; Kolfenbach, Jason R; Hughes-Austin, Jan M; Weisman, Michael H; Gilliland, William; Edison, Jess D; Buckner, Jane H; Mikuls, Ted R; O'Dell, James R; Keating, Richard M; Gregersen, Peter K; Norris, Jill M; Holers, V Michael; Deane, Kevin D

    2013-09-01

    To compare the diagnostic accuracy and agreement of commonly available assays for anti-citrullinated protein antibodies in patients with established rheumatoid arthritis (RA) and subjects at increased risk of RA. Tests for anti-cyclic citrullinated peptide (anti-CCP) antibodies were performed using CCP2 IgG and CCP3.1 IgA/IgG enzyme-linked immunosorbent assays in the following groups: probands with established RA (n = 340) from the Studies of the Etiology of Rheumatoid Arthritis (SERA) cohort and their first-degree relatives (FDRs) without inflammatory arthritis (n = 681), Department of Defense Serum Repository (DoDSR) RA cases with pre-RA diagnosis samples (n = 83; 47 cases also had post-RA diagnosis samples), and blood donor and DoDSR control subjects (n = 283). In patients with established RA, the CCP2 assay was more specific (99.2% versus 93.1%; P < 0.01) but less sensitive (58.7% versus 67.4%; P = 0.01) than the CCP3.1 assay; the specificity of the CCP3.1 assay increased to 97.2% when cutoff levels ≥3-fold the standard level were considered. In all subjects, CCP3.1 assay positivity (using standard cutoff levels) was more prevalent. Among DoDSR cases, the CCP2 assay was more specific than the CCP3.1 for predicting a future diagnosis of RA, and higher CCP levels trended toward increasing specificity for the development of RA within 2 years. At standard cutoff levels, assay agreement was good in patients with established RA (κ = 0.76) but poor in FDRs without inflammatory arthritis (κ = 0.25). Anti-CCP assays differ to an extent that may be meaningful for diagnosing RA in patients with inflammatory arthritis and evaluating the natural history of RA development in subjects at risk of RA. The mechanisms underlying these differences in test performance need further investigation. Copyright © 2013 by the American College of Rheumatology.

  17. Relation of rheumatoid factor and anti-cyclic citrullinated peptide antibody with disease activity in rheumatoid arthritis: cross-sectional study.

    PubMed

    Choe, Jung-Yoon; Bae, Jisuk; Lee, Hwajeong; Bae, Sang-Cheol; Kim, Seong-Kyu

    2013-09-01

    To analyze the association of rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (anti-CCP) with non-remission and with disease activity measures in rheumatoid arthritis (RA). Cross-sectional study of consecutive RA patients. Non-remission was defined as a disease activity score (DAS28) ≥ 2.6 at study enrollment. The Simplified Disease Activity Index (SDAI) and the Clinical Disease Activity Index (CDAI) were additionally measured. Serum titers of RF and anti-CCP were transformed into incremental levels (100/units) and log-transformed levels. Analysis of association with non-remission was done with logistic regression models, with and without adjustment for age, sex, disease duration, and corticoid use. Multiple regression models, raw and similarly adjusted, were used to measure the association of RF and anti-CCP with the disease activity measures. A total of 385 patients were included, of whom 286 (74 %) were not in remission. Log-transformed RF level was associated with an increased risk of non-remission after adjustment (OR = 1.32, 95 % CI 1.04-1.67). This association was especially evident in patients with less than 10 years of disease duration (OR = 1.51, 95 % CI 1.15-1.99) and in those using steroids (OR = 2.06, 95 % CI 1.22-3.48). Serum RF titers and log-transformed RF levels showed a small but significant association with DAS28 score (adjusted beta coefficients 0.002 and 0.18, respectively; both p ≤ 0.01), but neither with SDAI or CDAI nor with anti-CCP antibody. : Log-transformed RF levels might be associated with non-remission in RA, especially in patients with short disease duration or on steroids.

  18. Changes in anti-cyclic citrullinated peptide antibodies and rheumatoid factor isotypes serum levels in patients with rheumatoid arthritis following treatment with different biological drugs.

    PubMed

    Iannone, Florenzo; Tampoia, Marilina; Giannini, Margherita; Lopalco, Giuseppe; Cantarini, Luca; Villalta, C Danilo; Galeazzi, Mauro; Lapadula, Giovanni

    2016-01-01

    Anti-cyclic citrullinated peptide antibodies (anti-CCP) are a serological marker of rheumatoid arthritis (RA), and also have a prognostic value for more aggressive disease. Whether anti-CCP levels may change during treatment according to clinical response is matter of debate. Likewise, it is unknown whether different biological drugs have peculiar effects on anti-CCP levels. This study aimed to investigate changes in anti-CCP serum levels in RA patients on biological drugs with different mechanism of action. We studied 71 patients with active RA tested positive for anti-CCP who started a first biological drug (54 anti-TNF-α drug, 9 rituximab, 8 tocilizumab). In 14 patients stopping anti-TNF-α treatment for ineffectiveness, rituximab was started. Anti-CCP and rheumatoid factor (RF) isotypes (IgM, IgA, IgG) levels were measured at entry, 12 months and again at 12 months after swapping to rituximab. After 1 year of therapy of the first biological drug, patients taking anti-TNF-α drugs showed a significant reduction of the anti-CCP levels (p=0.002), and all RF isotypes (p=0.003). Also patients treated with rituximab or tolicizumab had a significant decrease in anti-CCP (p=0.01) and RF isotype levels (p=0.01). Anti-CCP levels did not correlated with DAS28 over time. In patients switching to rituximab after failure of TNF-α blockers, anti-CCP levels did not change at 12 months (p=0.06), despite of the reduction of DAS28 (p=0.02) and RFs levels (p=0.02). Our study showed that anti-CCP levels may change during RA course, regardless of the biological drug used and the clinical response.

  19. Diagnostic performance and predictive value of rheumatoid factor, anti-cyclic-citrullinated peptide antibodies and HLA-DRB1 locus genes in rheumatoid arthritis

    PubMed Central

    Fathi, Nihal A; Ezz-Eldin, Azza M; Mosad, Eman; Bakry, Rania M; Hamed, Hosny B; Ahmed, Sahar; Mahmoud, Marwa; Rashed, Hebat-Allah G; Abdullah, Fatma

    2008-01-01

    Background We evaluated the significance of the genes, defined as DRB1*04 or DRB1*01, in rheumatoid arthritis (RA) patients. We focused on the role of genetic and serologic markers to predict disease activity and destructive process of joints. Methods Sixty patients with RA were examined. Radiographic changes were evaluated by (Larsen score) and disease activity was measured by disease activity score 28 (DAS28). The markers analyzed were: erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-cyclic citrullinated peptides (anti-CCP2) and HLA-DRB1 alleles typed by PCR. Results In this study, anti-CCP antibodies, CRP, RF and AKA were detected in 83.3%, 56.7%, 71.7% and 52% of patients respectively. HLA-DRB1*01 was found in 45% of patients and 35% of them had one or two HLA-DRB1*04 alleles. According to DRB1*04 subtypes, (DRB1* 0405) was present in of 80% them. For prediction of grade of activity, the independent predictors were anti-CCP (OR 19.6), and DRB1*04 positive allele (OR 5.1). The combination of DRB1*04 + anti-CCP antibodies gave increase in the specificity and positive predictive value to 92% and 90 respectively. As regards to the prediction of radiological joint damage, the independent predictors were HLA-DRB1*04, HLA-DRB1*01, RF, and CRP > 18 (OR 5.5, 4.5, 2.5, 2.0 respectively). Conclusion Our findings suggest that anti-CCP2 is superior to RF for the detection of RA and provided predictive information on joint destruction and disease activity. The presence of RA associated antibodies (ACCP or RF) and/or the SE genes are indicative for a poorer radiological outcome and higher grade of activity. PMID:18945361

  20. Nicotine-induced differential modulation of autoimmune arthritis in the Lewis rat involves changes in IL-17 and anti-cyclic citrullinated peptide antibodies

    PubMed Central

    Yu, Hua; Yang, Ying-Hua; Rajaiah, Rajesh; Moudgil, Kamal D.

    2011-01-01

    Objective Rheumatoid arthritis (RA) is a debilitating autoimmune disease. Smoking is an important environmental factor in a subset of RA patients. Furthermore, the role of the cholinergic anti-inflammatory pathway in autoimmune inflammation is increasingly being realized. Nicotine is a major component of cigarette smoke and it also stimulates the α7-nicotinic acetylcholine receptors. Therefore, defining the mechanisms underlying the immunomodulatory effects of nicotine on arthritis is of high relevance. We have addressed this using the rat adjuvant-induced arthritis model of human RA. Methods Lewis rats were immunized s.c. with heat-killed M. tuberculosis H37Ra (Mtb) for disease induction. Rats were treated with nicotine i.p. either before (pretreatment) or after (posttreatment) the onset of AA. Control rats received the vehicle (buffer) in place of nicotine. The severity of arthritis was assessed and graded. The draining lymph node cells (LNC) were tested for T cell proliferative and cytokine responses against the disease-related antigen, mycobacterial heat-shock protein 65 (Bhsp65). The sera were tested for anti-cyclic citrullinated peptide antibodies (a-CCP) and anti-Bhsp65 antibodies. Results Nicotine-pretreatment aggravated arthritis, whereas nicotine posttreatment suppressed the disease. This altered severity of AA directly correlated with the levels of the aCCP antibodies, of the Th1/Th17 cytokines, and of the corresponding dendritic cell-derived cytokines. The majority of these effects on cellular responses could be replicated in vitro. Conclusion Nicotine-induced modulation of AA involves specific alterations in the disease-related cellular and humoral immune responses in AA. These results are of significance in advancing our understanding of the pathogenesis of RA. PMID:21305506

  1. Diagnostic value of high-frequency color Doppler ultrasonography examination in combination with anti-cyclic citrullinated peptide antibody testing in rheumatoid arthritis patients

    PubMed Central

    Wang, Ming-Yu; Wang, Xian-Bin; Sun, Xue-Hui; Liu, Feng-Li; Huang, Sheng-Chuan

    2017-01-01

    We studied the diagnostic value of high-frequency color Doppler ultrasonography (HCDU) examination in combination with anti-cyclic citrullinated peptide (anti-CCP) antibody testing in rheumatoid arthritis (RA) patients with finger joint damage. From January 2015 to December 2015, 80 patients diagnosed with RA with finger joints damage were enrolled in this study. Patients were examined with HCDU. Serum anti-CCP antibody level was tested using ELISA, and results were compared with the healthy control group. Results obtained by ELISA demonstrated that the positive rate of anti-CCP antibodies was 73.8% in the study group, and 10% in the control group. The negative rate was 26.2% in the study group, and 90% in the control group. HCDU examination suggested that the predominantly affected joint by bone erosion of RA with finger joint damage was MCP3 (16.7%), followed by PIP3 (14.1%), MCP2 (13.5%) and PIP2 (12.8%). The slightest affected joint was thumb metacarpophalangeal joint, followed by thumb, little finger metacarpophalangeal joint and proximal interphalangeal joint. The sensitivity of diagnosis of RA with finger joints damage with both HCDU and CCP antibody examination showed a significantly lower level compared with examination with each one of the methods alone, while specificity showed a significantly higher level. Thus, a combination of HCDU examination and anti-CCP antibody testing can be considered useful to improve the early diagnostic rate of RA. HCDU examination is a sensitive, secure, atraumatic and easily-operated diagnostic method for early RA patients with finger joint damage. When combined with anti-CCP antibody testing, it will provide a better chance for RA patients, and give them hope for a better treatment and improved prognosis. PMID:28450917

  2. Elevated Serum Levels of Interleukin-29 Are Associated with Disease Activity in Rheumatoid Arthritis Patients with Anti-Cyclic Citrullinated Peptide Antibodies.

    PubMed

    Chang, Qiong-Jie; Lv, Cheng; Zhao, Feng; Xu, Ting-Shuang; Li, Ping

    2017-02-01

    Rheumatoid arthritis (RA) is an inflammatory autoimmune disease that may lead to progressive joint destruction. The anti-cyclic citrullinated peptide (anti-CCP) antibody is an essential marker for the diagnosis of RA and has a crucial role in the bone destruction in RA. Recent studies have shown that interleukin (IL)-29, a vital member of type III interferon (IFN) family, could enhance proinflammatory cytokine production and might be involved in the joint destruction in RA. Therefore, in this study, we aimed to examine the role of IL-29 in RA patients with anti-CCP antibodies. The result showed that the serum IL-29 levels were higher in RA patients (n = 68) compared with healthy controls (HC, n = 68, P = 0.019). Correlation analysis demonstrated a significant positive correlation among serum IL-29 level, rheumatoid factor (RF, P < 0.001) and anti-CCP antibodies (P = 0.042). However, when RA patients were divided into two groups according to anti-CCP antibodies, the serum IL-29 levels were significantly higher in anti-CCP-antibodies positive RA patients (n = 54) than those in HC (n = 68) and anti-CCP-antibodies negative RA patients (n = 14). Furthermore, the serum IL-29 levels were positively correlated with the disease activity (P < 0.05) and significantly declined after 6 months of treatment (P < 0.01) in the anti-CCP-antibodies positive RA patients, whereas no significant change was found in the anti-CCP-antibodies negative RA patients (P > 0.05). The findings indicate that IL-29 is a potential biomarker for disease activity in anti-CCP-antibodies positive RA patients.

  3. A retrospective study of the fluctuation in serum levels of anti-cyclic citrullinated peptide antibody in patients with rheumatoid arthritis.

    PubMed

    Aotsuka, S; Okawa-Takatsuji, M; Nagatani, K; Nagashio, C; Kano, T; Nakajima, K; Ito, K; Mimori, A

    2005-01-01

    To investigate the fluctuation in serum levels of anti-cyclic citrullinated peptide antibody (anti-CCP) retrospectively in patients with rheumatoid arthritis (RA). Serum levels of anti-CCP were measured retrospectively in 131 patients with RA and 90 patients with non-RA rheumatic diseases using a commercially available kit. All sera were collected from patients during the 22-year period, 1982-2004. To analyze the fluctuation in anti-CCP levels, 17 RA patients were selected on the basis of showing a significantly higher anti-CCP level in a serum sample taken at the first visit (> 80 U/ml), and availability of preserved serum samples that had been taken from each patient at 10 time points. The test gave a sensitivity of 88% (115/131) and a specificity of 81% (73/90). The longitudinal study of 17 RA patients showed that anti-CCP levels were elevated at the first visit in 12 (71%) patients and then decreased gradually, whereas those in the other five (29%) patients fluctuated substantially. In both cases, anti-CCP levels tended to fluctuate in parallel with the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level, reflecting the spontaneous aggravation of arthritis and the efficacy of anti-rheumatic drugs. The courses of three representative RA patients are illustrated in detail along with their therapeutic regimens, and these further confirm the correlation of anti-CCP levels with laboratory parameters (ESR and CRP) as well as the activity of arthritis. Measurement of serum anti-CCP levels was found to be useful for not only the diagnosis but also the management of RA.

  4. Visual Assessment of Chest Computed Tomography Findings in Anti-cyclic Citrullinated Peptide Antibody Positive Rheumatoid Arthritis: Is it Associated with Airway Abnormalities?

    PubMed

    Park, Won Hong; Kim, Song Soo; Shim, Seung Cheol; Song, Seung Taek; Jung, Sung Soo; Kim, Jin Hwan; Kim, Namkug; Seo, Joon Beom

    2016-02-01

    We aimed to evaluate the association between specific anti-cyclic citrullinated peptide antibody (ACCPA) and pulmonary abnormalities in rheumatoid arthritis (RA) subjects. Computed tomography (CT) images of 83 subjects with RA were evaluated in a blind fashion. Enrolled subjects underwent autoantibody testing to determinate titer of ACCPA and rheumatoid factor, and pulmonary function testing. Visual CT assessment included lobar analysis for extent of semi-quantitative total interstitial lung disease score (ILDS) and each airway abnormality score (bronchiectasis, bronchial wall thickening, centrilobular nodules, and expiratory air trapping). Correlation tests, and simple and multiple regression analyses were performed to determine the relationship between the visual CT abnormalities, physiologic parameters, and autoantibody titers. ACCPA-positive subjects had a greater extent and higher prevalence of small airway abnormalities including centrilobular nodules and air trapping compared to ACCPA-negative subjects (all p < 0.05). Bronchiectasis and bronchial wall thickening correlated with the ratio of forced expiratory volume in 1 s and forced vital capacity (FVC) (r = -0.236 and r = -0.329, all p < 0.05), and ILDS correlated with FVC and the diffusing capacity of the lung for carbon monoxide (r = -0.218 and r = -0.366, all p < 0.05). Bronchial wall thickening and air trapping correlated with ACCPA titers (r = 0.235 and r = 0.264, all p < 0.05). Air trapping and bronchial wall thickening were significantly associated with ACCPA titers. In ACCPA (+) RA, visual CT assessment of large and small airways beyond RA-ILD, which is attributable to RA-related autoimmunity, can provide valuable information regarding airway abnormalities, regardless of the patients' physiologic airflow limitations.

  5. Pattern of thyroid, celiac, and anti-cyclic citrullinated peptide autoantibodies coexistence with type 1 diabetes mellitus in patients from Southwestern Saudi Arabia.

    PubMed

    Al-Hakami, Ahmed M

    2016-04-01

    To investigate the seroprevalence of coexisting autoantibodies among type 1 diabetes mellitus (T1DM) patients, and to look for possible correlations with age at diagnosis, diabetes duration, and glycemic control. This is a cross-sectional study conducted at Aseer Central Hospital, Abha, Kingdom of Saudi Arabia from March 2013 to June 2014. A total of 202 T1DM patients were screened for serum anti-thyroglobulin (TG), anti-thyroid peroxidase (TPO), anti-tissue transglutaminase (aTTG), anti-endomysial (EMA), and anti-cyclic citrullinated peptide (anti-CCP) antibodies along with glycated hemoglobin, and biometric data. From the 202 T1DM patients (96 males, and 106 females) (mean age: 11.3 years), 33 (16.3%) were positive for thyroid autoantibodies. Specifically, 19 (9.4%) were positive for TG and 25 (12.8%) were positive for TPO, and 11 were double positive. There were 21 (10.4%) patients that showed a double positive for both aTTG-IgA and EMA, and only one case of T1DM was positive for anti-CCP. No significant correlations were noticed between the presence of autoantibodies and the age at diagnosis, diabetes duration, body mass index, and glycemic control. The prevalence of thyroid and celiac disease autoantibodies is high among T1DM patients, while anti-CCP remains low and might be weakly associated with T1DM in the southwestern region of Saudi Arabia. No significant correlation between the age at T1DM diagnosis, duration, and glycemic control, and the presence of autoantibodies was found.

  6. Anti-cyclic citrullinated peptide antibody and rheumatoid factor isotypes in Iranian patients with rheumatoid arthritis: evaluation of clinical value and association with disease activity.

    PubMed

    Shakiba, Yadollah; Koopah, Susan; Jamshidi, Ahmad Reza; Amirzargar, Ali Akbar; Massoud, Ahmad; Kiani, Amir; Nicknam, Mohammad Hossein; Nazari, Bahareh; Nikbin, Behrouz

    2014-06-01

    In this study we determined the frequency, sensitivity and specificity of anti cyclic citrullinated peptides (anti-CCP) IgG antibody, total rheumatoid factor (RF-T), and RF isotypes in Iranian patients with rheumatoid arthritis (RA) and their association with age, clinical and serological parameters. Anti-CCP and RF-T and RF isotypes level were measured in 418 patients and 399 healthy controls by enzyme-linked immunosurbant assay (ELISA). Additionally, serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), visual analog scale (VAS) and disease activity score (DAS28) were evaluated in RA patients. The anti-CCP was positive in 53.1% of RA patients and 4.7% of controls. The frequency of RF-T was 61.87% and 17.66% in RA patients and controls respectively. The prevalence of RF isotypes in RA patients was 46.52% for RF-IgM, 23.47% for RF-IgA and 21.74% for RF-IgG. 31.39% of RA patients were RF-IgM positive without RF-IgA and RF-IgG and 21.9% were positive for all three RF classes. The anti-CCP positive patients showed increased number of swollen joints. On the other hand, RF-T positive patients exhibited a longer disease duration, lower age of onset and also higher ESR, CRP level and increased swollen joints. RF-T titer was significantly higher in RA patients with active disease compared to remission, low and moderate active groups. The sensitivity and specificity were 53.1, 95.3 for anti-CCP antibody and 61.8, 82.3 for RF-T. Our results support that anti-CCP and RF titer maybe valuable in estimation of disease activity and other inflammatory parameters in RA patients.

  7. Pattern of thyroid, celiac, and anti-cyclic citrullinated peptide autoantibodies coexistence with type 1 diabetes mellitus in patients from Southwestern Saudi Arabia

    PubMed Central

    Al-Hakami, Ahmed M.

    2016-01-01

    Objectives: To investigate the seroprevalence of coexisting autoantibodies among type 1 diabetes mellitus (T1DM) patients, and to look for possible correlations with age at diagnosis, diabetes duration, and glycemic control. Methods: This is a cross-sectional study conducted at Aseer Central Hospital, Abha, Kingdom of Saudi Arabia from March 2013 to June 2014. A total of 202 T1DM patients were screened for serum anti-thyroglobulin (TG), anti-thyroid peroxidase (TPO), anti-tissue transglutaminase (aTTG), anti-endomysial (EMA), and anti-cyclic citrullinated peptide (anti-CCP) antibodies along with glycated hemoglobin, and biometric data. Results: From the 202 T1DM patients (96 males, and 106 females) (mean age: 11.3 years), 33 (16.3%) were positive for thyroid autoantibodies. Specifically, 19 (9.4%) were positive for TG and 25 (12.8%) were positive for TPO, and 11 were double positive. There were 21 (10.4%) patients that showed a double positive for both aTTG-IgA and EMA, and only one case of T1DM was positive for anti-CCP. No significant correlations were noticed between the presence of autoantibodies and the age at diagnosis, diabetes duration, body mass index, and glycemic control. Conclusion: The prevalence of thyroid and celiac disease autoantibodies is high among T1DM patients, while anti-CCP remains low and might be weakly associated with T1DM in the southwestern region of Saudi Arabia. No significant correlation between the age at T1DM diagnosis, duration, and glycemic control, and the presence of autoantibodies was found. PMID:27052281

  8. Differential responsiveness to immunoablative therapy in refractory rheumatoid arthritis is associated with level and avidity of anti-cyclic citrullinated protein autoantibodies: a case study

    PubMed Central

    Teng, YK Onno; Verburg, Robert J; Verpoort, Kirsten N; Diepenhorst, Gwendolyn MP; Bajema, Ingeborg M; van Tol, Maarten JD; Jol-van der Zijde, Els CM; Toes, Rene EM; Huizinga, Tom WJ; van Laar, Jacob M

    2007-01-01

    In order to identify pathogenic correlates of refractory rheumatoid arthritis (RA), antibodies against anti-cyclic citrullinated protein (ACPAs) were investigated in RA patients in whom the dysregulated immune system had been ablated by high-dose chemotherapy (HDC) and autologous haematopoietic stem cell transplantation (HSCT). Six patients with refractory RA were extensively characterized in terms of levels of total immunoglobulins, RA-specific autoantibodies (ACPAs and rheumatoid factor) and antibodies against rubella, tetanus toxoid (TT) and phosphorylcholine before and after HDC plus HSCT. Additionally, the avidity of ACPAs was measured before and after treatment and compared with the avidity of TT antibodies following repeated immunizations. Synovial biopsies were obtained by arthroscopy before HDC plus HSCT, and analyzed by immunohistochemistry. In the three patients with clinically long-lasting responses to HDC plus HSCT (median 423 days), significant reductions in ACPA-IgG levels after therapy were observed (median level dropped from 215 to 34 arbitrary units/ml; P = 0.05). In contrast, stable ACPA-IgG levels were observed in three patients who relapsed shortly after HDC plus HSCT (median of 67 days). Clinical responders had ACPA-IgG of lower avidity (r = 0.75; P = 0.08) and higher degree of inflammation histologically (r = 0.73; P = 0.09). Relapse (after 38 to 530 days) in all patients was preceded by rising levels of low avidity ACPA-IgG (after 30 to 388 days), in contrast to the stable titres of high avidity TT antibodies. In conclusion, humoral autoimmune responses were differentially modulated by immunoablative therapy in patients with synovial inflammation and low avidity ACPA-IgG autoantibodies as compared with patients with high levels of high avidity ACPA-IgG. The distinct clinical disease course after immunoablative therapy based on levels and avidity of ACPA-IgG indicates that refractory RA is not a single disease entity. PMID:17927821

  9. Evaluation of Anti-Cyclic Citrullinated Peptide Autoantibodies and C-Reactive Protein in Common Autoimmune Skin Diseases with and without Arthritis.

    PubMed

    Kumari, Bandana; Kumar, Pawan; Chaudhary, Radha Krishna Prasad

    2017-07-01

    Anti-Cyclic Citrullinated Peptides (CCPs) are a well known diagnostic and prognostic noble marker for rheumatoid arthritis. C-Reactive Protein (CRP) is an acute phase protein whose level rises in response to inflammation. This study was undertaken to show the role of the two markers (anti-CCPs and CRP) in autoimmune skin disorder and their association with associated arthritis in these disorder. Serum anti-CCP antibodies and CRP was measured in 50 patients of autoimmune skin disease of which 28 were of psoriasis, 12 of Systemic Lupus Erythematosus (SLE) and 10 of Pemphigus Vulgaris (PV). These patients were categorised in two groups, with associated arthritis and without arthritis. The serum level of anti-CCP and CRP was correlated with the presence or absence of arthritis in these patients. Control group consists of 20 healthy subjects in which these two parameters were measured. Out of total of 50 patients, anti-CCP was raised in 36.37% of patients with associated arthritis and 12.82% of patients without arthritis whereas CRP was raised in 63.63% of patients with arthritis and 35.89% of patients without arthritis. Mean serum anti-CCP in patient with arthritis was 15.78±13.94 U/ml and without arthritis was 7.56±7.68 U/ml with p=0.01 which was statistically significant. Mean serum CRP in arthritis was 21.11±15.51 mg/l and CRP without arthritis was 13.14±12.27 mg/l with p=0.07 which was statistically not significant. Although both anti-CCP and CRP are valuable markers for autoimmune skin disorder, anti-CCP seems to show significant association with arthritis.

  10. Anti-carbamylated protein antibodies in unaffected first-degree relatives of rheumatoid arthritis patients: lack of correlation with anti-cyclic citrullinated protein antibodies and rheumatoid factor.

    PubMed

    Alessandri, C; Bartosiewicz, I; Pendolino, M; Mancini, R; Colasanti, T; Pecani, A; Morello, F; Mastrangelo, A; Sabatinelli, D; Riccieri, V; Di Franco, M; Ceccarelli, F; Perricone, C; Conti, F; Valesini, G

    2015-01-01

    To investigate the prevalence of anti-carbamylated protein antibodies (anti-CarP) in the healthy first-degree relatives (HFDRs) of patients with rheumatoid arthritis (RA). We enrolled 141 HFDRs of 63 patients with RA diagnosed accordingly to the 2010 ACR/EULAR criteria. Fifty-six normal healthy subjects (NHS), sex- and age-matched, served as controls. Anti-CarP IgG, anti-cyclic citrullinated peptide antibody (anti-CCP) IgG and rheumatoid factors (RF) isotypes (IgG, IgA, IgM) were assessed by solid-phase ELISA. Anti-CarP were detectable in 13 HFDRs (9.2%), anti-CCP in 9 (6.3%), IgG-RF in 10 (7%), IgA-RF in 17 (12%), and IgM-RF in 13 (9.2%) HFDRs. Twenty-nine (46%) RA patients were positive for anti-CarP, 31 (49.2%) for anti-CCP, and 34 (53.9%) for RF. One NHS (1.7%) resulted positive for anti-CarP, none for anti-CCP and RF. Anti-CarP showed significantly higher serum levels in RA and HFDRs than in NHS (p<0.0001 and p=0.0012, respectively). A significant correlation between anti-CCP and RF were found among RA patients (p=0.0002), whereas no correlations were reported between autoantibodies tested in the HFDRs. Anti-CarP can be found in the sera of HFDRs of RA patients and their prevalence is significantly higher than in NHS. No correlation of anti-CarP with anti-CCP and RF antibodies in RA HFDRs was found.

  11. Diagnostic accuracy of combined tests of anti cyclic citrullinated peptide antibody and rheumatoid factor for rheumatoid arthritis: a meta-analysis.

    PubMed

    Sun, Jianhong; Zhang, Yuhui; Liu, Lei; Liu, Gang

    2014-01-01

    To evaluate the diagnostic properties of combined tests of anti cyclic citrullinated peptide antibody (anti-CCP) and rheumatoid factor (RF) in the diagnosis of rheumatoid arthritis (RA). We performed an extensive research between January 2000 and January 2013 of the published literature. A random-effects model was used to summarise data from 24 studies that conformed to our inclusion criteria. Heterogeneity among studies was evaluated by threshold effect analysis and meta-regression. The summary estimates for anti-CCP antibody and RF positivity (both serum markers had to be positive) in the diagnosis of RA were: sensitivity 57% (95% confidence interval (CI), 55% to 59%), specificity 96% (CI, 96% to 97%), positive likelihood ratio (LR) 13.84 (CI, 10.56 to 18.12), negative LR 0.46 (CI, 0.40 to 0.52), diagnostic odds ratio (DOR) 33.02 (CI, 23.89 to 45.64). The pooled data for anti-CCP antibody or RF positivity (one serum marker had to be positive) were: sensitivity 78% (CI, 76% to 80%), specificity 82% (CI, 81% to 84%), positive LR 4.24 (CI, 3.61 to 4.97), negative LR 0.27 (CI, 0.22 to 0.34), DOR 16.95 (CI, 12.96 to 22.18). Both anti-CCP antibody and RF positivity are useful for ruling in the diagnosis of RA, and positivity combined improves the probability of true positivity in the diagnosis. Anti-CCP antibody or RF positivity shows low specificity and positive LR, and should be integrated with other examinations to make a final diagnosis.

  12. Effect of the human leukocyte antigen HLA-DRB1 and anti-cyclic citrullinated peptide on the outcome of rheumatoid arthritis patients.

    PubMed

    Farouk, H M; Mansour, H E; Rahman, S A; Mostafa, A A; Shamy, H A; Zarouk, W A

    2009-09-01

    Our objective was to determine whether the presence of the human leukocyte antigen HLA-DRB1 locus is associated with production of anti-cyclic citrullinated peptide antibodies (anti-CCP Abs) and to what extent they are associated with increased susceptibility to and severity of rheumatoid arthritis (RA) in Egyptian patients. Twenty-nine RA patients gave informed consent to participate in a case-control study that was approved by the Ain Shams University Medical Ethics Committee. RA disease activity and severity were determined using the simplified disease activity index and Larsen scores, respectively. We used a wide scale national study on the pattern of HLA typing in normal Egyptians as a control study. Anti-CCP Abs and HLA-DRB1 typing were determined for all subjects. The alleles most strongly associated with RA were HLA-DRB1 [*01 , *04 and *06] (41.4%). RA patients with serum anti-CCP Ab titers above 60 U/mL had a significantly higher frequency of HLA-DRB1*01 (58.3%) and HLA-DRB1*04 alleles (83.3%). Significant positive correlations were found between serum and synovial anti-CCP Ab titer, RA disease activity, and severity (r = 0.87, 0.66 and 0.63, respectively; P < 0.05). HLA-DRB1 SE+ alleles [*01 and *04] were highly expressed among Egyptian RA patients. The presence of these alleles was associated with higher anti-CCP Ab titer, active and severe RA disease. Early determination of HLA-DRB1 SE+ alleles and serum anti-CCP Ab could facilitate the prediction of the clinical course and prognosis of RA when first evaluated leading to better disease control.

  13. Gene-environmental interaction between smoking and shared epitope on the development of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis: a meta-analysis.

    PubMed

    Lee, Young Ho; Bae, Sang-Cheol; Song, Gwan Gyu

    2014-06-01

    The aim of this study was to determine the gene-environment interactions of smoking and shared epitope (SE) both separately and combined on anti-cyclic citrullinated peptide (CCP) antibodies in patients with rheumatoid arthritis (RA). The literature was searched using the MEDLINE, EMBASE and Cochrane databases. A meta-analysis on the associations between tobacco exposure (TE) and/or SE and the development of anti-CCP antibodies in patients with RA was performed. Eight comparison studies with 5317 RA patients were considered in this meta-analysis. The odds ratio (OR) for positive anti-CCP antibodies in TE+/SE- patients with RA was increased compared with TE-/SE- patients (OR = 1.373, 95% CI = 1.111-1.698, P = 0.003). The ORs for positive anti-CCP antibodies in TE-/SE+ patients and TE+/SE+ patients with RA were also increased compared with TE-/SE- patients (OR = 2.678, 95% CI = 2.031-3.532, P < 1.0 × 1(0-9) in TE-/SE+; OR = 4.233, 95% CI = 2.458-7.291, P = 1.9 × 10(-8) in TE+/SE+). Stratification by ethnicity indicated the same pattern as that shown in the overall group. The OR for positive anti-CCP antibodies in TE+/SE+ patients with RA was much higher than in TE-/SE- patients in Europeans and Asians (OR = 3.879, 95% CI = 2.203-6.830, P = 2.6 × 10(-7); OR = 10.504, 95% CI = 3.182-34.67, P = 1.1 × 10(-4)). This meta-analysis suggests a gene-environmental interaction between smoking and SE for the development of anti-CCP antibodies. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  14. Impact of baseline anti-cyclic citrullinated peptide-2 antibody concentration on efficacy outcomes following treatment with subcutaneous abatacept or adalimumab: 2-year results from the AMPLE trial.

    PubMed

    Sokolove, Jeremy; Schiff, Michael; Fleischmann, Roy; Weinblatt, Michael E; Connolly, Sean E; Johnsen, Alyssa; Zhu, Jin; Maldonado, Michael A; Patel, Salil; Robinson, William H

    2016-04-01

    To examine whether baseline anti-cyclic citrullinated peptide-2 (CCP2) antibody status and concentration correlated with clinical outcomes in patients treated with abatacept or adalimumab on background methotrexate (MTX) in the 2-year AMPLE (Abatacept versus adaliMumab comParison in bioLogic-naïvE rheumatoid arthritis subjects with background MTX) study. In this exploratory analysis, anti-CCP2 antibody concentration was measured at baseline, and antibody-positive patients were divided into equal quartiles, Q1-Q4, representing increasing antibody concentrations. Clinical outcomes analysed by baseline anti-CCP2 status and quartile included change from baseline in disease activity and disability and remission rates. Baseline characteristics were generally comparable across quartiles and treatment groups. In both treatment groups, anti-CCP2 antibody-negative patients responded less well than antibody-positive patients. At year 2, improvements in disease activity and disability and remission rates were similar across Q1-Q3, but were numerically higher in Q4 in the abatacept group; in contrast, treatment effects were similar across all quartiles in the adalimumab group. In AMPLE, baseline anti-CCP2 positivity was associated with a better response for abatacept and adalimumab. Patients with the highest baseline anti-CCP2 antibody concentrations had better clinical response with abatacept than patients with lower concentrations, an association that was not observed with adalimumab. NCT00929864. 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/

  15. Comparison of anti-mutated citrullinated vimentin, anti-cyclic citrullinated peptides, anti-glucose-6-phosphate isomerase and anti-keratin antibodies and rheumatoid factor in the diagnosis of rheumatoid arthritis in Chinese patients.

    PubMed

    Zhu, Tao; Feng, Liyun

    2013-04-01

    To evaluate the diagnostic value of anti-mutated citrullinated vimentin antibodies (anti-MCV), anti-cyclic citrullinated peptides antibodies (anti-CCP), anti-glucose-6-phosphate isomerase antibodies (anti-GPI) and anti-keratin antibodies (AKA) and rheumatoid factor (RF) in rheumatoid arthritis (RA). The five auto-antibodies were detected in serum samples of 56 patients with RA, 21 patients with systemic lupus erythematosus (SLE), 11 with ankylosing spondylitis (AS), six with Sjögren's syndrome (SS), four with connective tissue disease (CTD) and 20 healthy controls. Anti-MCV, anti-CCP and anti-GPI were detected by enzyme-linked immunosorbent assays (ELISA), AKA was determined by indirect immunofluorescence and RF was determined by rate nephelometry. In RA, anti-MCV and anti-GPI had the highest sensitivity (78.6% and 75.0%, respectively), anti-CCP and AKA had the highest specificity (97.6%). Anti-GPI had the lowest specificity (64.3%), and AKA had the lowest sensitivity (48.2%). When two antibodies were detected together, the sensitivity of anti-MCV/anti-CCP/RF were highest (92.9%) with a lower specificity (73.8%). The combination of anti-MCV/anti-CCP had a slightly decreased sensitivity (89.3%) and the same specificity (73.8%). The combination RF/anti-MCV/anti-CCP or anti-MCV/anti-CCP are usefully serologic tests for the diagnosis of RA in Chinese patients. © 2013 The Authors International Journal of Rheumatic Diseases © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  16. Early prediction of rheumatoid arthritis by magnetic resonance imaging in the absence of anti-cyclic citrullinated peptide antibodies and radiographic erosions in undifferentiated inflammatory arthritis patients: a prospective study.

    PubMed

    Ji, Lanlan; Li, Guangtao; Xu, Yufeng; Zhou, Wei; Zhang, Zhuoli

    2015-11-01

    To assess the practicability of magnetic resonance imaging (MRI) in confirming the diagnosis of clinically suspected rheumatoid arthritis (RA), when anti-cyclic citrullinated peptide antibody and radiographic erosions are absent. We prospectively involved 31 treatment-naive patients with early inflammatory arthritis. At the initial visit, X-rays and gadolinium-enhanced MRI of both hands, as well as serological examinations and acute phase reactants were performed. The scores of synovitis, bone edema, bone erosion and tenosynovitis of metacarpophalangeal and wrist joints were evaluated using the RA-MRI scoring system. For all the patients, radiographs at baseline were normal and anti-cyclic citrullinated peptide antibodies were negative. At the end of follow-up(median 15 months, range 12-20 months), 22 patients were diagnosed as having RA according to 1987 American College of Rheumatology criteria. Bone edema, erosions, synovitis and tenosynovitis were observed in all the patients. However, the frequency of symmetric synovitis in wrists was significantly higher in the RA group. Moreover this group turned out to have significantly higher MRI bone erosion score in wrists. Further, receiver operating characteristic curve analysis revealed a positive wrist bone erosion score at 5, with a specificity of 78% and a sensitivity of 68%. There was no significant difference between the two groups with respect to metacarpophalangeal synovitis, metacarpophalangeal bone erosion, bone edema or tenosynovitis. MRI evidence of symmetric synovitis at wrist and a high bone erosion score at that site may assist in making an early diagnosis of RA in those patients who are negative for anti-cyclic citrullinated peptide antibody. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  17. Anti-cyclic citrullinated peptide antibody predicts functional disability in patients with rheumatoid arthritis in a large prospective observational cohort in Japan.

    PubMed

    Shidara, Kumi; Inoue, Eisuke; Hoshi, Daisuke; Sato, Eri; Nakajima, Ayako; Momohara, Shigeki; Taniguchi, Atsuo; Yamanaka, Hisashi

    2012-02-01

    To clarify the clinical significance of anti-cyclic citrullinated peptide antibody (anti-CCP) in the long-term outcome of RA, we established a large observational cohort of RA patients (IORRA) in our institute beginning in 2000. Essentially all RA patients who consulted our institute were registered, and clinical parameters, including disease activity and drug use, were assessed biannually based on patient reports, physician examinations, and laboratory data. In the third phase (October 2001) of the IORRA survey, anti-CCP levels were measured in 1,226 RA patients. In a cross-sectional analysis, clinical variables were compared in anti-CCP-positive versus -negative patients and in RF-positive versus -negative patients. In a longitudinal analysis, subsequent progression of disability was analyzed in anti-CCP-positive versus -negative and in RF-positive versus -negative patients. A verified Japanese version of the Health Assessment Questionnaire (J-HAQ) was used to measure functional disability. In the cross-sectional analysis, anti-CCP-positive patients (84.2%) had a significantly longer disease duration and higher disease activity score and more frequently used corticosteroids and methotrexate compared to anti-CCP-negative patients statistically. Similar phenomena were noted between RF-positive and -negative patients. In contrast, the longitudinal analysis revealed that J-HAQ slopes-a measure of progression of functional disability-were strongly associated with anti-CCP positivity but not with RF positivity. In a linear regression model, J-HAQ scores significantly worsened in anti-CCP-positive patients compared to anti-CCP-negative patients at the third year (annual progression 0.0317, P = 0.001) and the fifth year (annual progression 0.0199, P = 0.0012); however, J-HAQ progression was not influenced by RF status. Anti-CCP is a better predictive and discriminative marker for progression of disability in the long-term outcome of RA patients compared to RF.

  18. Comparison of anti-agalactosyl IgG antibodies, rheumatoid factors, and anti-cyclic citrullinated peptide antibodies in the differential diagnosis of rheumatoid arthritis and its mimics.

    PubMed

    Lu, M-C; Hsieh, S-C; Lai, N-S; Li, K-J; Wu, C-H; Yu, C-L

    2007-01-01

    Anti-agalactosyl IgG antibodies [anti-Gal(0) IgG] have been regarded as a useful serological marker for rheumatoid arthritis (RA). Our aim was to evaluate the clinical usefulness of anti-Gal(0) IgG in the differential diagnosis of rheumatic disorders that mimic RA compared to rheumatoid factors (RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP). Sera were collected from 39 patients with RA, 49 patients with primary Sjögren's syndrome (pSjS), 47 patients with systemic lupus erythematosus (SLE), 65 patients with chronic hepatitis B viral infection (HBV), 68 patients with chronic hepatitis C viral infection (HCV) and 19 normal individuals. RF-IgM was measured by the nephelometeric method, and RF-IgA, anti-Gal(0) IgG and anti-CCP were measured by the respective ELISA assays. Anti-Gal(0) IgG titers were remarkably elevated in patients with RA (191.0 +/- 250.8 AU/ml) compared to pSjS (37.9 +/- 42.6 AU/ml), SLE (10.3 +/- 13.6 AU/ml), chronic HBV with (36.1 +/- 38.4 AU/ml) or without rheumatic symptoms (9.6 +/- 19.4 AU/ml), RF(+) chronic HCV without rheumatic symptoms (19.0 +/- 14.8 AU/ml), chronic HCV with rheumatic symptoms (15.2 +/- 17.4 AU/ml) and healthy individuals (2.6 +/- 0.7 AU/ml). The specificity of anti-Gal(0) IgG could be greatly enhanced by elevating the cut-off value from 12 AU/ml to 40 AU/ml (68.6% vs. 85.6%, p < 0.001) without significantly compromising its sensitivity (76.9% vs. 61.5%, p > 0.05). The serum titer of anti-Gal(0) IgG is much higher in rheumatoid arthritis than in mimicking diseases. The specificity of anti-Gal(0) IgG is enhanced when the cut-off value is raised. However, anti-CCP remains the most specific biomarker for RA.

  19. The PTPN22 1858C/T polymorphism is associated with anti-cyclic citrullinated peptide antibody-positive early rheumatoid arthritis in northern Sweden

    PubMed Central

    Kokkonen, Heidi; Johansson, Martin; Innala, Lena; Jidell, Erik; Rantapää-Dahlqvist, Solbritt

    2007-01-01

    The PTPN22 1858C/T polymorphism has been associated with several autoimmune diseases including rheumatoid arthritis (RA). We have shown that carriage of the T variant (CT or TT) of PTPN22 in combination with anti-cyclic citrullinated peptide (anti-CCP) antibodies highly increases the odds ratio for developing RA. In the present study we analysed the association between the PTPN22 1858C/T polymorphism and early RA in patients from northern Sweden, related the polymorphism to autoantibodies and the HLA-DR shared epitope, and analysed their association with markers for disease activity and progression. The inception cohort includes individuals who also donated samples before disease onset. A case–control study was performed in patients (n = 505; 342 females and 163 males) with early RA (mean duration of symptoms = 6.3 months) and in population-based matched controls (n = 970) from northern Sweden. Genotyping of the PTPN22 1858C/T polymorphism was performed using a TaqMan instrument. HLA-shared epitope alleles were identified using PCR sequence-specific primers. Anti-CCP2 antibodies were determined using enzyme-linked immunoassays. Disease activity (that is, the number of swollen and tender joints, the global visual analogue scale, and the erythrocyte sedimentation rate) was followed on a regular basis (that is, at baseline and after 6, 12, 18 and 24 months). Both the 1858T allele and the carriage of T were associated with RA (χ2 = 23.84, P = 0.000001, odds ratio = 1.69, 95% confidence interval = 1.36–2.11; and χ2 = 22.68, P = 0.000002, odds ratio = 1.79, 95% confidence interval = 1.40–2.29, respectively). Association of the 1858T variant with RA was confined to seropositive disease. Carriage of 1858T and the presence of anti-CCP antibodies was independently associated with disease onset at an earlier age (P < 0.05 and P < 0.01, respectively), while the combination of both resulted in an even earlier age at onset. Smoking was identified as a risk factor

  20. Replication of Associations of Genetic Loci Outside the HLA Region With Susceptibility to Anti-Cyclic Citrullinated Peptide-Negative Rheumatoid Arthritis.

    PubMed

    Viatte, Sebastien; Massey, Jonathan; Bowes, John; Duffus, Kate; Eyre, Stephen; Barton, Anne; Worthington, Jane

    2016-07-01

    Genetic polymorphisms within the HLA region explain only a modest proportion of anti-cyclic citrullinated peptide (anti-CCP)-negative rheumatoid arthritis (RA) heritability. However, few non-HLA markers have been identified so far. This study was undertaken to replicate the associations of anti-CCP-negative RA with non-HLA genetic polymorphisms demonstrated in a previous study. The Rheumatoid Arthritis Consortium International densely genotyped 186 autoimmune-related regions in 3,339 anti-CCP-negative RA patients and 15,870 controls across 6 different populations using the Illumina ImmunoChip array. We performed a case-control replication study of the anti-CCP-negative markers with the strongest associations in that discovery study, in an independent cohort of anti-CCP-negative UK RA patients. Individuals from the arcOGEN Consortium and Wellcome Trust Case Control Consortium were used as controls. Genotyping in cases was performed using Sequenom MassArray technology. Genome-wide data from controls were imputed using the 1000 Genomes Phase I integrated variant call set release version 3 as a reference panel. After genotyping and imputation quality control procedures, data were available for 15 non-HLA single-nucleotide polymorphisms in 1,024 cases and 6,348 controls. We confirmed the known markers ANKRD55 (meta-analysis odds ratio [OR] 0.80; P = 2.8 × 10(-13) ) and BLK (OR 1.13; P = 7.0 × 10(-6) ) and identified new and specific markers of anti-CCP-negative RA (prolactin [PRL] [OR 1.13; P = 2.1 × 10(-6) ] and NFIA [OR 0.85; P = 2.5 × 10(-6) ]). Neither of these loci is associated with other common, complex autoimmune diseases. Anti-CCP-negative RA and anti-CCP-positive RA are genetically different disease subsets that only partially share susceptibility factors. Genetic polymorphisms located near the PRL and NFIA genes represent examples of genetic susceptibility factors specific for anti-CCP-negative RA. © 2016 The Authors. Arthritis

  1. The diagnostic utility of matrix metalloproteinase-3 and high-sensitivity C-reactive protein for predicting rheumatoid arthritis in anti-cyclic citrullinated peptide antibody-negative patients with recent-onset undifferentiated arthritis.

    PubMed

    Hiura, Kazuya; Iwaki-Egawa, Sachiko; Kawashima, Toshiyuki; Fujisawa, Shin-Ichi; Takeda, Tsuyoshi; Komori, Hitoshi; Watanabe, Yasuhiro

    2013-09-01

    Anti-cyclic citrullinated peptide (anti-CCP) antibodies are well-established serological markers that show high sensitivity and specificity in early rheumatoid arthritis (RA) and are associated with bone erosions of RA. However, some patients subsequently progress to RA even if there is no presence of anti-CCP antibodies in an early stage. The aim of this study is to evaluate the diagnostic utility of matrix metalloproteinase-3 (MMP-3), high-sensitivity C-reactive protein (hsCRP) and IgM rheumatoid factor for predicting RA in anti-CCP-negative patients with recent-onset undifferentiated arthritis (UA). Baseline levels of those markers were measured at the entry of the study. A total of 99 patients with UA were included, among them 44 patients (44.4 %) had been classified as having RA by a skilled rheumatologist at some point during 1-year follow-up. Of these 99 patients, 34 patients (34.3 %) had anti-CCP antibodies and 65 patients (65.7 %) had no anti-CCP antibodies. Eleven patients who were anti-CCP-negative developed RA. We compared sensitivity, specificity, positive predictive value and negative predictive value of serum markers of these anti-CCP-negative RA patients. The combined usage of MMP-3 with hsCRP is relatively superior to other markers as predictors of RA.

  2. Women with rheumatoid arthritis negative for anti-cyclic citrullinated peptide and rheumatoid factor are more likely to improve during pregnancy, whereas in autoantibody-positive women autoantibody levels are not influenced by pregnancy.

    PubMed

    de Man, Y A; Bakker-Jonges, L E; Goorbergh, C M Dufour-van den; Tillemans, S P R; Hooijkaas, H; Hazes, J M W; Dolhain, R J E M

    2010-02-01

    To determine whether changes in levels of anti-cyclic citrullinated peptide (anti-CCP) and rheumatoid factor (RF) are associated with the spontaneous improvement of rheumatoid arthritis (RA) during pregnancy and with the subsequent flare post partum. Disease activity scores from the Pregnancy-induced Amelioration of Rheumatoid Arthritis (PARA) study of 118 patients were available for analysis. Before conception (if applicable), at each trimester and at 6, 12 and 26 weeks post partum, levels of the autoantibodies anti-CCP, IgM-RF, IgG-RF and IgA-RF were determined. Responses in disease activity were classified according to European League Against Rheumatism (EULAR) response criteria during pregnancy and post partum, and associated with the presence or absence of autoantibodies. The median levels of anti-CCP and all subclasses of RF during pregnancy were stable, whereas post partum the levels of anti-CCP, IgM-RF and IgA-RF declined. A significantly higher percentage of women without autoantibodies (negative for anti-CCP and RF) improved compared with women positive for either or both autoantibodies (75% vs 39%, p = 0.01). The occurrence of a flare post partum was comparable between these groups. Improvement of disease activity of RA during pregnancy was not associated with changes in levels of autoantibodies during pregnancy, however, improvement may occur more frequently in the absence of anti-CCP and RF.

  3. A transmembrane polymorphism in FcgammaRIIb (FCGR2B) is associated with the production of anti-cyclic citrullinated peptide autoantibodies in Taiwanese RA.

    PubMed

    Chen, J-Y; Wang, C-M; Ma, C-C; Hsu, L-A; Ho, H-H; Wu, Y-J J; Kuo, S-N; Wu, J

    2008-12-01

    The aim of the current study was to determine whether the FcgammaRIIb 187-Ile/Thr polymorphism is a predisposition factor for subtypes of RA defined by disease severity and production of autoantibodies against cyclic citrullinated peptides (anti-CCPs) in Taiwanese RA patients. Genotype distributions and allele frequencies of FcgammaRIIb 187-Ile/Thr were compared between 562 normal healthy controls and 640 RA patients as stratified by clinical parameters and autoantibodies. Significant enrichment of 187-Ile allele was observed in RA patients positive for anti-CCP antibodies as compared with the anti-CCP negative RA patients (P=0.001, OR 1.652 (95% CI 1.210-2.257)) or as compared with the normal controls (P=0.005, OR 1.348 (95% CI 1.092-1.664)). In addition, 187-Ile allele was found to be enriched in RA patients positive for rheumatoid factor (RF) compared to the RF negative RA patients (P=0.024, OR 1.562 (95% CI 1.059-2.303)). Furthermore, the homozygotes were enriched in destructive male RA patients (P=0.035; OR 2.038 (95% CI 1.046-3.973)) and the 187-Ile allele was associated with early-onset of RA in Taiwanese patients (P=0.045, OR 1.548 (95% CI 1.007-2.379)). Thus, FcgammaRIIb SNP 187-Ile/Thr may influence the RA phenotypes in Taiwanese RA.

  4. Strong combined gene-environment effects in anti-cyclic citrullinated peptide-positive rheumatoid arthritis: a nationwide case-control study in Denmark.

    PubMed

    Pedersen, Merete; Jacobsen, Søren; Garred, Peter; Madsen, Hans O; Klarlund, Mette; Svejgaard, Arne; Pedersen, Bo V; Wohlfahrt, Jan; Frisch, Morten

    2007-05-01

    To study the role of shared epitope (SE) susceptibility genes, alone and in combination with tobacco smoking and other environmental risk factors, for risk of subtypes of rheumatoid arthritis (RA) defined by the presence or absence of serum antibodies against cyclic citrullinated peptides (CCPs). To address these issues, a nationwide case-control study was conducted in Denmark during 2002-2004, comprising incident cases of RA or patients with recently diagnosed RA (309 seropositive and 136 seronegative for IgG antibodies against CCP) and 533 sex- and age-matched population controls. Associations were evaluated by logistic regression analyses, in which odds ratios (ORs) served as measures of relative risk. Compared with individuals without SE susceptibility genes, SE homozygotes had an elevated risk of anti-CCP-positive RA (OR 17.8, 95% confidence interval [95% CI] 10.8-29.4) but not anti-CCP-negative RA (OR 1.07, 95% CI 0.53-2.18). Strong combined gene-environment effects were observed, with markedly increased risks of anti-CCP-positive RA in SE homozygotes who were heavy smokers (OR 52.6, 95% CI 18.0-154), heavy coffee drinkers (OR 53.3, 95% CI 15.5-183), or oral contraceptive users (OR 44.6, 95% CI 15.2-131) compared with SE noncarriers who were not exposed to these environmental risk factors. Persons who are homozygous for SE susceptibility genes, notably those who are also exposed to environmental risk factors, have a markedly and selectively increased risk of anti-CCP-positive RA. A distinction between anti-CCP-positive RA and anti-CCP-negative RA seems warranted, because these RA subtypes most likely represent etiologically distinct disease entities.

  5. Anti-cyclic citrullinated peptide antibodies do not reflect self-reported disability and physical health in patients with rheumatoid arthritis of less than 5 years of duration.

    PubMed

    Poulsen, Chalotte Heinsvig; Jacobsen, Søren; Frisch, Morten; Frederiksen, Kirsten; Johansen, Christoffer

    2013-11-01

    It is well accepted that patients with antibodies against cyclic citrullinated peptides (anti-CCP) and rheumatoid arthritis (RA) suffer from more severe forms of RA in terms of clinical presentation and radiographic destruction at long term compared to anti-CCP-negative patients. The purpose of this cross-sectional study was to investigate whether the measures of self-reported health among patients with RA of <5 years of duration are influenced by anti-CCP status. Additionally, we aimed to determine whether the measures of self-reported health among the two patient groups differ from those of a control group. Telephone interviews were conducted with 464 patients with RA and 637 population controls, who reported educational level, income, smoking habits and lifestyle 10 years before the interview and completed the Health Assessment Questionnaire and the Short-Form Health Survey Questionnaire, version 2 (SF-36v2); 424 (91%) patients submitted a blood sample for analysis. Patients with anti-CCP-positive and anti-CCP-negative RA showed no significant differences in self-reported disability and physical health after adjustment for age, gender, socioeconomic factors, lifestyle and disease-related variables (p > 0.05). Both groups of RA patients reported significantly more physical disabilities in everyday life and significantly poorer physical health than the controls (both p < 0.001). A similar pattern was seen for self-reported mental health (both p < 0.05). Patients with RA of <5 years of duration report significantly more disability and poorer physical health than the general population of Denmark, but these reports were independent of anti-CCP status.

  6. The additional benefit of ultrasonography to 2010 ACR/EULAR classification criteria when diagnosing rheumatoid arthritis in the absence of anti-cyclic citrullinated peptide antibodies.

    PubMed

    Ji, Lanlan; Deng, Xuerong; Geng, Yan; Song, Zhibo; Zhang, Zhuoli

    2017-02-01

    The aim of this study was to assess the benefit of ultrasonography (US) contributing to 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria in diagnosing rheumatoid arthritis (RA), when anti-citrullinated protein (CCP) antibody and radiographic erosions are absent. Ninety-four patients suffering from arthritis of at least one joint in hands, symptom duration of less than 2 years, normal radiographs at baseline, and negative anti-CCP had 22 joint US assessments and were followed prospectively for at least 12 months. Sensitivity and specificity for final RA diagnosis based on 1987 RA criteria were determined for ultrasound variables. Logistic regression models were then fitted to evaluate predictive ability over and above the 2010 ACR/EULAR classification criteria. Twenty-nine of them were classified as RA patients and 65 had alternative diagnoses. There were significantly more joints with synovial hypertrophy, synovitis, and bone erosion detected by US in RA patients. The gray-scale (GS) variables positively correlated with acute phase reactants. The area under curve (AUC) values of GS and power Doppler (PD) were comparable, higher than bone erosion. However, regression analysis demonstrated that only PD involvement of joints, especially wrists, provided independently predictive data, with improved AUC values from 0.738 to 0.872 combined with 2010 ACR/EULAR classification criteria. PD scanning of hand joints, especially wrists, may provide independently assistance to 2010 ACR/EULAR criteria in the early diagnosis of RA in those patients who are negative for anti-CCP antibody.

  7. Low-field magnetic resonance imaging or combined ultrasonography and anti-cyclic citrullinated peptide antibody improve correct classification of individuals as established rheumatoid arthritis: results of a population-based, cross-sectional study.

    PubMed

    Pedersen, Jens K; Lorenzen, Tove; Ejbjerg, Bo; Szkudlarek, Marcin; Voss, Anne; Østergaard, Mikkel; Svendsen, Anders J; Andersen, Lis S; Hørslev-Petersen, Kim

    2014-08-07

    The aim of the present study was to evaluate the accuracy of two approaches using magnetic resonance imaging (MRI) or combined ultrasonography (US) and anti-cyclic citrullinated peptide antibody (ACPA) for diagnosis and classification of individuals with established rheumatoid arthritis (RA). In 53 individuals from a population-based, cross-sectional study, historic fulfilment of the American College of Rheumatology (ACR) 1987 criteria ("classification") or RA diagnosed by a rheumatologist ("diagnosis") were used as standard references. The sensitivity, specificity and Area under Curve for Receiver Operating Characteristics curves (ROC-area: (sensitivity + specificity)/2) were calculated for "current fulfilment of the ACR 1987 criteria" (list format), "adapted ACR 1987 criteria" (list format, substituting IgM rheumatoid factor with ACPA and clinical joint swelling and erosions on radiography with synovitis and erosions detected by US on a semi-quantitative scale), and RA MRI scoring System (RAMRIS) scores on low-field MRI in the unilateral hand. For the ACR 1987 criteria the ROC-area was 75% (sensitivity/specificity = 50%/100%) (with "classification" as standard reference) and 69% (44%/94%) (with "diagnosis" as standard reference), while for the adapted ACR 1987 criteria it was 86% (75%/97%) (classification) and 82% (72%/91%) (diagnosis). For RAMRIS synovitis score in metacarpophalangeal (MCP) joints only (cut-off ≥5), the ROC-area (sensitivity/specificity) was 78% (62%/94%) (classification) and 85% (69%/100%) (diagnosis), while for the total synovitis score of MCP joints plus wrist (cut-off ≥10) it was 78% (62%/94%) (both classification and diagnosis). Compared with the ACR 1987 criteria, low-field MRI alone or adapted criteria incorporating US and ACPA increased the correct classification and diagnosis of RA.

  8. The status of rheumatoid factor and anti-cyclic citrullinated peptide antibody are not associated with the effect of anti-TNFα agent treatment in patients with rheumatoid arthritis: a meta-analysis.

    PubMed

    Lv, Qianwen; Yin, Yufeng; Li, Xin; Shan, Guangliang; Wu, Xiangni; Liang, Di; Li, Yongzhe; Zhang, Xuan

    2014-01-01

    This meta-analysis was conducted to investigate whether the status of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibody are associated with the clinical response to anti-tumor necrosis factor (TNF) alpha treatment in rheumatoid arthritis (RA). A systemic literature review was performed using the MEDLINE, SCOPUS, Cochrane Library, ISI Web of Knowledge, and Clinical Trials Register databases, and Hayden's criteria of quality assessment for prognostic studies were used to evaluate all of the studies. The correlation between the RF and anti-CCP antibody status with the treatment effect of anti-TNFα agents was analyzed separately using the Mantel Haenszel method. A fixed-effects model was used when there was no significant heterogeneity; otherwise, a random-effects model was applied. Publication bias was assessed using Egger's linear regression and a funnel plot. A total of 14 studies involving 5561 RA patients meeting the inclusion criteria were included. The overall analysis showed that the pooled relative risk for the predictive effects of the RF and anti-CCP antibody status on patient response to anti-TNFα agents was 0.98 (95% CI: 0.91-1.05, p=0.54) and 0.88 (95% CI: 0.76-1.03, p=0.11), respectively, with I(2) values of 43% (p=0.05) and 67% (p<0.01), respectively. Subgroup analyses of different anti-TNFα treatments (infliximab vs. etanercept vs. adalimumab vs. golimumab), response criteria (DAS28 vs. ACR20 vs. EULAR response), follow-up period (≥ 6 vs. <6 months), and ethnic group did not reveal a significant association for the status of RF and anti-CCP. Neither the RF nor anti-CCP antibody status in RA patients is associated with a clinical response to anti-TNFα treatment.

  9. What is the ability of anti-cyclic citrullinated peptide antibodies determination in synovial fluid in discriminating rheumatoid arthritis from non-rheumatoid arthritis patients? A Tunisian cross-sectional study.

    PubMed

    Mrabet, Dalila; Laadhar, Lilia; Sahli, Héla; Zouari, Béchir; Haouet, Slim; Lahmar, Houria; Makni, Sondes; Sellami, Slaheddine

    2012-02-01

    Anti-cyclic citrullinated peptide antibodies (ACPA) seem to be produced locally at the site of joints inflammation in the first stage of rheumatoid arthritis (RA). A strong correlation between serum ACPA and ACPA in the synovial fluid (SF-ACPA) is now suggested. A case-control study was conducted to evaluate the usefulness of ACPA determination in SF of patients with RA. A total of 53 patients with a knee-joint effusion (26 RA, 18 peripheral spondyloarthropathies (SPA), and 9 osteoarthritis (OA)) were included in our study. SF samples were obtained by performing therapeutic arthrosynthesis. IgG serum ACPA and SF-ACPA levels were determined by the enzyme-linked immunosorbent assay (ELISA). We have also determined IgG levels in serum and SF by nephelometry. Higher levels of IgG ACPA antibodies in SF (p = 0.045) and serum (p = 0.045) were found in patients with RA with respect to SPA and OA patients. The Spearman correlation analysis showed a significant and positive correlation between ACPA in serum and SF (rho = 0.516; p = 0.007) not only in the RA group but also in patients with SPA. Serum ACPA discriminated RA from non-RA at a cut-off value of 2.7 U/ml (sensitivity, 69%; specificity, 78%; and area under the curve (AUC), 0.72), whereas SF-ACPA discriminated RA from non-RA at a higher cut-off value of 4.95 U/ml (sensitivity, 73%; specificity, 61%; and AUC, 0.71). Our study suggests that the determination of SF-ACPA give complement information to serum ACPA in patients with RA.

  10. The Diagnostic Utility of Anti-cyclic Citrullinated Peptide Antibodies, Matrix Metalloproteinase-3, Rheumatoid Factor, Erythrocyte Sedimentation Rate, and C-reactive Protein in Patients with Erosive and Non-erosive Rheumatoid Arthritis

    PubMed Central

    Shovman, O.; Gilburd, B.; Zandman-Goddard, G.; Sherer, Y.; Orbach, H.; Gerli, R.; Shoenfeld, Y.

    2005-01-01

    Objective: To compare the diagnostic utility of laboratory variables, including matrix metalloproteinase-3 (MMP-3), anti-cyclic citrullinated peptide (CCP) antibodies, rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) in patients with erosive and non-erosive rheumatoid arthritis (RA). Methods: We assembled a training set, consisting of 60 patients with RA, all fulfilling the revised criteria of the American College of Rheumatology. A commercial enzyme linked immunosorbent assay (ELISA) was used both to test for anti-CCP antibodies (second generation ELISA kit) and MMP; RF were detected by latex-enhanced immunonephelometric assay. CRP was measured by latex turbidimetric immunoassay. Results: The levels of anti-CCP antibody titers and ESR were significantly higher in patients with erosive disease than those in non-erosive RA patients (p < 0.001 and 0.0341) respectively. Moreover, a higher frequency of elevated titers of anti-CCP antibodies was found in RA patients with erosions compared to patients with non-erosive RA (78.3% vs. 43.2% respectively). The ROC curves of anti-CCP passed closer to the upper left corner than those other markers and area under the curve (AUC) of anti-CCP was significantly larger than AUC of other markers (0.755 for anti-CCP, 0.660 for ESR, 0.611 for CRP, 0.577 for RF, and 0.484 for MMP-3 female). A positive predictive value was higher for anti-CCP antibodies in comparison to other markers. We did not find significant statistical correlation between anti-CCP antibody titers and inflammatory markers such as ESR or CRP. However, we confirmed the correlation of elevated titers of anti-CCP antibodies and RF in both groups of patients whereas the degree of correlation was more significant in non-erosive patients. Conclusion: The results of our study suggest that the presence of elevated anti-CCP antibody titers have better diagnostic performance than MMP-3, RF, CRP and ESR in patients with erosive RA. PMID

  11. The diagnostic utility of anti-cyclic citrullinated peptide antibodies, matrix metalloproteinase-3, rheumatoid factor, erythrocyte sedimentation rate, and C-reactive protein in patients with erosive and non-erosive rheumatoid arthritis.

    PubMed

    Shovman, O; Gilburd, B; Zandman-Goddard, G; Sherer, Y; Orbach, H; Gerli, R; Shoenfeld, Y

    2005-09-01

    To compare the diagnostic utility of laboratory variables, including matrix metalloproteinase-3 (MMP-3), anticyclic citrullinated peptide (CCP) antibodies, rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) in patients with erosive and non-erosive rheumatoid arthritis (RA). We assembled a training set, consisting of 60 patients with RA, all fulfilling the revised criteria of the American College of Rheumatology. A commercial enzyme linked immunosorbent assay (ELISA) was used both to test for anti-CCP antibodies (second generation ELISA kit) and MMP; RF were detected by latex-enhanced immunonephelometric assay. CRP was measured by latex turbidimetric immunoassay. The levels of anti-CCP antibody titers and ESR were significantly higher in patients with erosive disease than those in non-erosive RA patients (p < 0.001 and 0.0341) respectively. Moreover, a higher frequency of elevated titers of anti-CCP antibodies was found in RA patients with erosions compared to patients with non-erosive RA (78.3% vs. 43.2% respectively). The ROC curves of anti-CCP passed closer to the upper left corner than those other markers and area under the curve (AUC) of anti-CCP was significantly larger than AUC of other markers (0.755 for anti-CCP, 0.660 for ESR, 0.611 for CRP, 0.577 for RF, and 0.484 for MMP-3 female). A positive predictive value was higher for anti-CCP antibodies in comparison to other markers. We did not find significant statistical correlation between anti-CCP antibody titers and inflammatory markers such as ESR or CRP. However, we confirmed the correlation of elevated titers of anti-CCP antibodies and RF in both groups of patients whereas the degree of correlation was more significant in non-erosive patients. The results of our study suggest that the presence of elevated anti-CCP antibody titers have better diagnostic performance than MMP-3, RF, CRP and ESR in patients with erosive RA.

  12. Immunoglobulin (Ig)G1 and IgG4 anti-cyclic citrullinated peptide (CCP) associate with shared epitope, whereas IgG2 anti-CCP associates with smoking in patients with recent-onset rheumatoid arthritis (the Swedish TIRA project).

    PubMed

    Martinsson, K; Johansson, A; Kastbom, A; Skogh, T

    2017-04-01

    Given the possible importance of anti-citrullinated peptide/protein antibodies (ACPA) for initiation and progression of rheumatoid arthritis (RA), extended knowledge about the different isotypes and subclasses is important. In the present study, we analysed the immunoglobulin (Ig)G subclasses regarding reactivity against cyclic citrullinated peptides (anti-CCP) among 504 clinically well-characterized patients with recent-onset RA in relation to smoking habits, shared epitope (SE) status and IgA and pan-IgG anti-CCP antibodies. All patients, regardless of pan-IgG anti-CCP status, were analysed for IgG1-4 CCP reactivity. Sixty-nine per cent were positive in any IgG anti-CCP subclass, and of these 67% tested positive regarding IgG1, 35% IgG2, 32% IgG3, and 59% IgG4 anti-CCP. Among ever-smokers the percentages of IgG2 anti-CCP (P = 0·01) and IgA anti-CCP (P = 0·002)-positive cases were significantly higher compared to never-smokers. A positive IgG anti-CCP subclass -negative cases. Combining SE and smoking data revealed that IgG1 and IgG4 anti-CCP were the IgG anti-CCP isotypes associated with expression of SE, although the lower number of patients positive for IgG2 or IgG3 anti-CCP could, however, have influenced the results. High levels of IgG2 anti-CCP were shown to correlate with expression of the 'non-SE' allele human leucocyte antigen (HLA)-DRB1*15. In conclusion, in this study we describe different risk factor characteristics across the IgG anti-CCP subclasses, where IgG2 appears similar to IgA anti-CCP regarding the predominant association with smoking, while IgG1 and IgG4 related more distinctly to the carriage of SE genes. © 2016 British Society for Immunology.

  13. Evaluation of anti-citrullinated type II collagen and anti-citrullinated vimentin antibodies in patients with juvenile idiopathic arthritis

    PubMed Central

    2013-01-01

    Background To determine the prevalence and significance of anti-citrullinated vimentin and anti-citrullinated type II collagen antibodies and elucidate their role in the disease process of juvenile idiopathic arthritis (JIA). Methods Sera were obtained from 95 patients with various subtypes of JIA, 19 systemic lupus erythematosus (SLE) patients, and 10 healthy children. Antibodies were measured in the sera against citrullinated and native type II collagen and vimentin (vim1-16 and vim 59-74) by enzyme-linked immunosorbent assay. Samples were compared to anti-cyclic citrullinated peptide (anti-CCP) antibody and rheumatoid factor (RF) isotypes, and our previously measured anti-citrullinated fibrinogen and α-enolase antibodies on the same patient population, in addition to erythrocyte sedimentation rate and C-reactive protein. The relationship between the anti-citrullinated antibody profile and disease activity and joint damage were also investigated. Results Twenty-three JIA patients (24%) demonstrated reactivity to anti-citrullinated type II collagen. Ten JIA patients (10.5%) demonstrated reactivity to anti-citrullinated vimentin 1–16 antibodies and 7 (7.4%) to anti-citrullinated vimentin 59–74 antibodies. One IgM RF-positive polyarticular patient was positive for all 5 of the citrullinated autoantibodies tested. Thirty-seven different subsets of patients were identified based on their anti-citrullinated autoantibody and RF isotype profile. No significant associations were noted with anti-citrullinated type II collagen and anti-citrullinated vimentin antibodies with joint damage or disease activity. Anti-citrullinated vimentin 59–74 antibodies demonstrated the highest overall specificity at 89.7%, with anti-citrullinated vimentin 1–16 and anti-citrullinated type II collagen antibodies at 86.2%. Conclusion This study demonstrates that antibodies to multiple citrullinated epitopes are present in the sera of patients with various subtypes of JIA. It also

  14. Anti-cyclic citrullinated peptide antibodies in psoriatic arthritis--cross-sectional study and literature review.

    PubMed

    Popescu, C; Zofotă, S; Bojincă, V; Ionescu, R

    2013-01-01

    Anti-CCP antibodies are detectable not only in rheumatoid arthritis (RA), but also in psoriatic arthritis (PsA). It is possible those anti-CCP antibodies are associated with features of PsA and that these auto-antibodies are useful in distinguishing PsA from RA. to evaluate the prevalence and the associations of anti-CCP antibodies in PsA patients; to evaluate the usefulness of anti-CCP antibodies in distinguishing PsA from RA. The inquiry was designed as a cross-sectional study of 41 PsA patients, 139 RA patients and 147 normal subjects, which recorded demographic data, disease activity and serology: rheumatoid factor (RF), anti-CCP antibodies. Five PsA patients (12.2%) were anti-CCP positive. Compared to anti-CCP negative PsA patients, anti-CCP positive PsA patients had a more frequently a polyarticular disease pattern (p = 0.005), they were more frequently treated with biologics (p = 0.015) and less frequently with classic disease-modifying drugs (p < 0.001). An optimal positive cutoff value for anti-CCP titer was determined (11.6 U/mL), over which it is highly probable that a known PsA patient actually has RA and psoriasis. The more aggressive the disease of anti-CCP positive PsA patients indicates the need of a more intensive management regarding anti-rheumatic treatment and follow-up. Anti-CCP antibodies can be a useful tool in differentiating PsA from RA, especially in RA-like forms of PsA, which present no elements pertaining to spondyloarthropathies.

  15. Meta-Analysis: Diagnostic Accuracy of Anti-Cyclic Citrullinated Peptide Antibody for Juvenile Idiopathic Arthritis

    PubMed Central

    Wang, Yan; Pei, Fengyan; Wang, Xingjuan; Sun, Zhiyu; Hu, Chengjin; Dou, Hengli

    2015-01-01

    Objective. To estimate the diagnostic accuracy of the anti-CCP test in JIA and to evaluate factors associated with higher accuracy. Methods. Two investigators performed an extensive search of the literature published between January 2000 and January 2014. The included articles were assessed by the Quality Assessment of Diagnostic Accuracy Studies tool. The meta-analysis was performed using a summary ROC (SROC) curve and a bivariate random-effect model to estimate sensitivity and specificity across studies. Results. The bivariate meta-analysis yielded a pooled sensitivity and specificity of 10% (95% confidence interval (CI): 6.0%–15.0%) and 99.0% (95% CI: 98.0%–100.0%). The area under the SROC curve was 0.96. Sensitivity estimates were highly heterogeneous, which was partially explained by the higher sensitivity in the rheumatoid factor-positive polyarthritis (RF+ PA) subtype (48.0%; 95% CI: 31.0%–65.0%) than in the other subtypes (17.0%; 95% CI: 14.0%–20.0%) and the higher sensitivity of the Inova assay (17.0%; 95% CI: 14.0%–20.%%) than the other assays (0.05%; 95% CI: 2.0%–11.0%). Conclusions. Anti-CCP antibody test has a high specificity for the diagnosis of JIA. The sensitivity of this test is low and varies across populations but is higher in RF+ PA than in other JIA subtypes. PMID:25789331

  16. Detection of anti-cyclic citrullinated peptide using a time-resolved fluoroimmunoassay.

    PubMed

    Xiao, Jinhua; Hu, Zhigang; Liu, Jie; Li, Mei; Zou, Yaohong

    2014-01-01

    In an effort to enhance the linear range of anti-CCP we developed a new immunoassay based on time-resolved fluoroimmunoassay. The precision, sensitivity, specificity, and stability of the assay were evaluated ELISA set as control. The anti-CCP IgG TRFIA kit we established had a wider detectable range than commercial ELISA ones. With regard to intra- and inter-assay precision, the TRFIA kit was better than threee commercial ELISA ones. The mean recovery rate was 101.0%. The TRFIA we developed for anti-CCP IgG detection yielded a more sensitive and reliable method for RA diagnosis and large-scale screening programs as well.

  17. Meta-analysis: diagnostic accuracy of anti-cyclic citrullinated peptide antibody for juvenile idiopathic arthritis.

    PubMed

    Wang, Yan; Pei, Fengyan; Wang, Xingjuan; Sun, Zhiyu; Hu, Chengjin; Dou, Hengli

    2015-01-01

    To estimate the diagnostic accuracy of the anti-CCP test in JIA and to evaluate factors associated with higher accuracy. Two investigators performed an extensive search of the literature published between January 2000 and January 2014. The included articles were assessed by the Quality Assessment of Diagnostic Accuracy Studies tool. The meta-analysis was performed using a summary ROC (SROC) curve and a bivariate random-effect model to estimate sensitivity and specificity across studies. The bivariate meta-analysis yielded a pooled sensitivity and specificity of 10% (95% confidence interval (CI): 6.0%-15.0%) and 99.0% (95% CI: 98.0%-100.0%). The area under the SROC curve was 0.96. Sensitivity estimates were highly heterogeneous, which was partially explained by the higher sensitivity in the rheumatoid factor-positive polyarthritis (RF+ PA) subtype (48.0%; 95% CI: 31.0%-65.0%) than in the other subtypes (17.0%; 95% CI: 14.0%-20.0%) and the higher sensitivity of the Inova assay (17.0%; 95% CI: 14.0%-20.%%) than the other assays (0.05%; 95% CI: 2.0%-11.0%). Anti-CCP antibody test has a high specificity for the diagnosis of JIA. The sensitivity of this test is low and varies across populations but is higher in RF+ PA than in other JIA subtypes.

  18. Abbott AxSYM Vancomycin II assay: multicenter evaluation and interference studies.

    PubMed

    Azzazy, H M; Chou, P P; Tsushima, J H; Troxil, S; Gordon, M; Avers, R J; Chiappetta, E; Duh, S H; Christenson, R H

    1998-04-01

    The authors evaluated the performance characteristics of the Abbott AxSYM Vancomycin II immunoassay in sera of patients with (n = 93 samples) and without (n = 327 patients) renal dysfunction. Correlation of vancomycin measurements with the Abbott AxSYM Vancomycin, Abbott TDx/TDxFLx, Syva enzyme-multiplied immunoassay technique (EMIT), DuPont automated chemistry analyzer (ACA), and high-performance liquid chromatography methods showed acceptable correlation as indicated by: slope values >0.95, r-values >0.97, y-intercepts <1.7 microg/ml, and S(y/x) ranging from 9% to 15% of the average vancomycin value. The AxSYM Vancomycin II assay showed acceptable correlation with AxSYM vancomycin, TDx/TDxFLx, and high-performance liquid chromatography methods in 93 samples from patients with renal dysfunction. This monoclonal antibody-based assay showed no apparent interference from the presence of human antimouse antibody (HAMA) or the microbiologically inactive vancomycin crystalline degradation product (CDP). The authors conclude that the AxSYM Vancomycin II assay showed satisfactory agreement with other methods tested in this study.

  19. Autoantibodies From Single Circulating Plasmablasts React With Citrullinated Antigens and Porphyromonas gingivalis in Rheumatoid Arthritis.

    PubMed

    Li, Song; Yu, Yangsheng; Yue, Yinshi; Liao, Hongyan; Xie, Wanqin; Thai, Jessica; Mikuls, Ted R; Thiele, Geoffrey M; Duryee, Michael J; Sayles, Harlan; Payne, Jeffrey B; Klassen, Lynell W; O'Dell, James R; Zhang, Zhixin; Su, Kaihong

    2016-03-01

    Anti-citrullinated protein antibodies (ACPAs) are highly specific for rheumatoid arthritis (RA). However, the molecular basis for ACPA production is still unclear. The purpose of this study was to determine if circulating plasmablasts from RA patients produce ACPAs and whether Porphyromonas gingivalis facilitates the generation of ACPAs. Using a single-cell antibody cloning approach, we generated 217 and 110 monoclonal recombinant antibodies from circulating plasmablasts from 7 RA patients and 4 healthy controls, respectively. Antibody reactivity with citrullinated antigens was tested by a second-generation anti-cyclic citrullinated peptide (anti-CCP) kit and by enzyme-linked immunosorbent assays (ELISAs) against citrullinated human antigens. Antibody reactivity with P gingivalis was tested by ELISAs against outer membrane antigens (OMAs) and citrullinated enolase from P gingivalis. Approximately 19.5% of plasmablast-derived antibodies from anti-CCP-positive RA patients, but none from 1 anti-CCP-negative RA patient or the healthy controls, specifically recognized citrullinated antigens. The immunoglobulin genes encoding these ACPAs were highly mutated, with increased ratios of replacement mutations to silent mutations, suggesting the involvement of active antigen selection in ACPA generation. Interestingly, 63% of the ACPAs cross-reacted with OMAs and/or citrullinated enolase from P gingivalis. The reactivity of ACPAs against citrullinated proteins from P gingivalis was confirmed by immunoblotting and mass spectrometry. Furthermore, some germline-reverted ACPAs retained their reactivity with P gingivalis antigens but completely lost their reactivity with citrullinated human antigens. These results suggest that circulating plasmablasts in RA patients produce ACPAs and that this process may be facilitated by anti-P gingivalis immune responses. © 2016, American College of Rheumatology.

  20. Usefulness of anti-cyclic citrullinated peptide antibody and rheumatoid factor to detect rheumatoid arthritis in patients with systemic sclerosis.

    PubMed

    Ueda-Hayakawa, Ikuko; Hasegawa, Minoru; Kumada, Sayako; Tanaka, Chihiro; Komura, Kazuhiro; Hamaguchi, Yasuhito; Takehara, Kazuhiko; Fujimoto, Manabu

    2010-11-01

    The purpose of this study was to determine the prevalence of anti-CCP antibodies (anti-CCP Abs) and to assess associations between the presence of anti-CCP Ab and arthritis or arthralgia in SSc patients. Serum samples were obtained from 146 SSc patients. Anti-CCP Ab, anti-agalactosyl (AG) IgG Ab, IgM-RF, IgG-RF and MMP-3 were determined, respectively. The presence of anti-CCP Ab was found in 18/146 (12%) patients with SSc. Elevated levels of anti-AG IgG Abs, IgM- and IgG-RFs were observed in 50/146 (34%), 17/146 (12%) and 4/146 (3%), respectively. Serum anti-CCP Ab levels were significantly elevated in SSc-RA overlap patients compared with SSc patients with or without arthralgia (P < 0.05 or P < 0.001, respectively). Serum MMP-3 levels did not correlate with the presence of arthritis or arthralgia but were significantly associated with modified Rodnan total skin thickness score. In SSc-RA overlap patients, 10/11 (91%) patients were positive for two or more RA-related Abs. The serum titre of anti-CCP Ab is higher in SSc-RA overlap patients than in SSc patients with or without arthralgia. The finding of high titres of anti-CCP Abs and the elevated levels combinatory with other RA-related Abs may help to define the diagnosis of SSc-RA overlap. MMP-3 might be a better marker to assess skin involvement rather than joint involvement in SSc patients.

  1. Multicenter clinical and analytical evaluation of the AxSYM troponin-I immunoassay to assist in the diagnosis of myocardial infarction.

    PubMed

    Apple, F S; Maturen, A J; Mullins, R E; Painter, P C; Pessin-Minsley, M S; Webster, R A; Spray Flores, J; DeCresce, R; Fink, D J; Buckley, P M; Marsh, J; Ricchiuti, V; Christenson, R H

    1999-02-01

    We evaluated the AxSYM troponin I (cTnI) immunoassay for assisting in the detection of acute myocardial infarction (AMI). At four sites, the total imprecision (CV) over 20 days was 6.3-10.2%. The minimum detectable concentration was 0.14 +/- 0.05 microgram/L. Comparison of cTnI measurements between the AxSYM and Stratus (n = 406) over the dynamic range of the AxSYM assay demonstrated good correlation, r = 0.881, with a proportional bias: AxSYM cTnI = 3.50(Stratus cTnI) - 1. 10. The confidence intervals (95%) for the slope and intercept were 3.39-3.64 and -1.32 to -0.95, respectively. The expected cTnI concentration in healthy individuals was AxSYM cTnI with the Stratus cTnI, OPUS cTnI, and Access cTnI were 95.3%, 95.1%, and 94.3%, respectively, from patients with suspected AMI. The AxSYM cTnI demonstrated excellent clinical specificity, >/=96%, in skeletal muscle injury, chronic renal disease, and same-day noncardiac surgery patients.

  2. Are there autoantibodies reacting against citrullinated peptides derived from type I and type II collagens in patients with rheumatoid arthritis?

    PubMed Central

    Koivula, M; Aman, S; Karjalainen, A; Hakala, M; Risteli, J

    2005-01-01

    Objectives: To assess the possible presence in patients with rheumatoid arthritis (RA) of autoantibodies recognising citrullinated peptides derived from type I and II collagens. Methods: Firstly, the binding of four pairs of synthetic peptides (arginine-containing and artificially citrullinated forms) related to different regions of human type II collagen were tested with sera from 120 patients with RA and 81 controls. Secondly, two similar pairs of peptides related to the carboxy terminal telopeptides of the α1 and α2 chains of human type I collagen were tested. Results: 42–53% of the RA sera showed increased binding of arginine peptides related to type II collagen. However, 12 RA sera bound the citrullinated form of the α1(II) telopeptide more strongly than the corresponding arginine peptide. 20 RA sera bound the citrullinated carboxytelopeptide from the α1 chain of type I collagen (α1(I) telopeptide) more strongly than the respective arginine peptide. The correlation between the autoantibodies to type I and II collagen telopeptides was rs = 0.576, p<0.001. Anti-cyclic citrullinated peptide (anti-CCP) assay was positive in 71/120 (59%) patients with RA. An anti-CCP assay detects a different subgroup of antibodies than anti-telopeptide assays. However, both anti-telopeptide and anti-CCP antibodies were increased in patients with RA. Conclusion: Some patients with RA were identified whose sera contained antibodies that specifically bound citrullinated peptides related to the carboxy terminal telopeptides of the α1 and α2 chains of type I collagen and the α1 chains of type II collagen (sequences YYXA, FYXA, and YMXA, where X stands for citrulline). PMID:16162901

  3. Diagnostic performance of anti-citrullinated protein/peptide antibodies in juvenile idiopathic arthritis.

    PubMed

    Pang, S Y; Liu, H Y; Huang, Y J; Liu, Y F; Dai, Y M; Zeng, P; Zeng, H S

    2016-05-13

    The prevalence rates of anti-citrullinated protein/peptide antibodies (ACPAs) were investigated in a cohort of juvenile idiopathic arthritis (JIA) patients, and their diagnostic performances were compared. ACPAs, including anti-cyclic citrullinated peptide IgG (anti-CCP), anti-CCP IgG/IgA (anti-CCP3.1), citrullinated recombinant rat filaggrin antibodies (CPA), anti-mutated citrullinated vimentin (anti-MCV), and antibodies to citrullinated human IgG-derived peptides (RA/CP), were measured in the sera from 81 JIA patients. Serum samples from 55 children with other joint diseases or viral infections and 49 healthy donors were tested as controls. Of the 81 JIA patients, 7 (8.6%), 8 (9.9%), 17 (21.0%), 23 (28.4%), and 18 (22.2%) were found to be positive for anti-CCP, anti-CCP3.1, CPA, anti-MCV, and RA/CP, respectively, with specificities of 98.1, 95.1, 93.3, 84.6, and 86.5%. Analysis by subtype revealed that 7/7 (100%) of RF-positive polyarticular JIA patients tested positive at high serum levels for anti-MCV or RA/CP, and 5/7 (71.4%) were positive for anti-CCP, anti- CCP3.1, or CPA (P < 0.001, compared with controls). Eighteen of 81 JIA patients demonstrated joint erosions on radiographs and erosive arthritis occurred more often in ACPAs positive patients (P < 0.01). Our findings indicate that although ACPAs are not satisfactory screening biomarkers for JIA due to low sensitivity, ACPA measurement can aid in diagnosing RF-positive polyarticular JIA and identifying JIA patients with severe bone involvement. The diagnostic performance of each ACPA in JIA is different, and the careful selection of assays is necessary.

  4. Candidate autoantigens identified by mass spectrometry in early rheumatoid arthritis are chaperones and citrullinated glycolytic enzymes

    PubMed Central

    Goëb, Vincent; Thomas-L'Otellier, Marlène; Daveau, Romain; Charlionet, Roland; Fardellone, Patrice; Le Loët, Xavier; Tron, François; Gilbert, Danièle; Vittecoq, Olivier

    2009-01-01

    Introduction The aim of our study was to identify new early rheumatoid arthritis (RA) autoantibodies. Methods Sera obtained from 110 early untreated RA patients (<6 months) were analyzed by western blot using HL-60 cell extract, separated on one-dimensional and two-dimensional gel electrophoresis (1-DE, 2-DE). Sera from 50 healthy blood donors and 20 patients with non-RA rheumatisms were used as controls for 1-DE and 2-DE, respectively. The immunoreactive proteins were identified by MALDI-TOF mass spectrometric analysis and the presence of potential sites of citrullination in each of these proteins was evaluated. FT-ICR mass spectrometry was used to verify experimentally the effect of citrullination upon the mass profile observed by MALDI-TOF analysis. Results The 110 1-DE patterns allowed detection of 10 recurrent immunoreactive bands of 33, 39, 43, 46, 51, 54, 58, 62, 67 and 70 kDa, which were further characterized by 2-DE and proteomic analysis. Six proteins were already described RA antigens: heterogeneous nuclear ribonucleoprotein A2/B1, aldolase, α-enolase, calreticulin, 60 kDa heat shock protein (HSP60) and BiP. Phosphoglycerate kinase 1 (PGK1), stress-induced phosphoprotein 1 and the far upstream element-binding proteins (FUSE-BP) 1 and 2 were identified as new antigens. Post-translational protein modifications were analyzed and potentially deiminated peptides were found on aldolase, α-enolase, PGK1, calreticulin, HSP60 and the FUSE-BPs. We compared the reactivity of RA sera with citrullinated and noncitrullinated α-enolase and FUSE-BP linear peptides, and showed that antigenicity of the FUSE-BP peptide was highly dependent on citrullination. Interestingly, the anti-cyclic citrullinated peptide antibody (anti-CCP2) status in RA serum at inclusion was not correlated to the reactivity directed against FUSE-BP citrullinated peptide. Conclusions Two categories of antigens, enzymes of the glycolytic family and molecular chaperones are also targeted by the

  5. Evidence of fibrinogen as a target of citrullination in IgM rheumatoid factor-positive polyarticular juvenile idiopathic arthritis

    PubMed Central

    2011-01-01

    Background Several studies have noted the significance of measuring anti-cyclic citrullinated peptide (CCP) antibodies in juvenile idiopathic arthritis (JIA) as an important indicator for destructive disease, as is the case in rheumatoid arthritis (RA). While the role of anti-CCP antibodies in RA and JIA has become better understood, the identity of the target proteins of this modification has remained elusive. In this study, we evaluated serum from patients with various subtypes of JIA to investigate the presence of anti-deiminated (citrullinated) fibrinogen and anti-citrullinated α-enolase antibodies, and their association with RF and anti-CCP antibody isotypes. Methods Sera were obtained from 96 JIA patients, 19 systemic lupus erythematosus (SLE) patients, and 10 healthy children. All sera were measured for antibodies against citrullinated and native fibrinogen and α-enolase by an enzyme linked immunosorbent assay (ELISA). In addition, all sera were assayed for anti-CCP antibody isotypes and rheumatoid factor (RF) isotypes by ELISA. The relationship between anti-citrullinated fibrinogen and anti-α-enolase antibodies and disease activity and joint damage were also investigated. All results were correlated with clinical and laboratory parameters using Spearman's rho correlation coefficient. Multiple logistic regression analysis was utilized to identify which variables were associated with joint erosions and diagnosis of JIA. Results Thirty-one JIA patients (32%) demonstrated reactivity to citrullinated fibrinogen and 9 (9%) to citrullinated α-enolase. Reactivity to citrullinated fibrinogen and α-enolase was predominantly found in IgM RF-positive polyarthritis patients. Fourteen JIA patients reacted with native α-enolase and a higher percentage of SLE patients reacted with citrullinated α-enolase when compared to JIA patients. Anti-citrullinated fibrinogen antibodies correlated with the presence of IgG anti-CCP antibodies and IgA and IgM RF. The presence of

  6. Periodontal treatment decreases levels of antibodies to Porphyromonas gingivalis and citrulline in patients with rheumatoid arthritis and periodontitis.

    PubMed

    Okada, Moe; Kobayashi, Tetsuo; Ito, Satoshi; Yokoyama, Tomoko; Abe, Asami; Murasawa, Akira; Yoshie, Hiromasa

    2013-12-01

    Porphyromonas gingivalis has been implicated as an etiologic agent of rheumatoid arthritis (RA) because of the expression of peptidylarginine deiminase. The present study evaluates whether periodontal treatment may affect serum antibodies to P. gingivalis and citrulline levels in relation to disease activity of RA. Fifty-five patients with RA were randomly assigned to receive oral hygiene instruction and supragingival scaling (treatment group, n = 26) or no periodontal treatment (control group, n = 29). Periodontal and rheumatologic parameters and serum levels of cytokine and inflammatory markers citrulline and immunoglobulin (Ig)G to P. gingivalis were examined at baseline and 8 weeks later. Both groups did not differ statistically in any parameters except percentage of sites with probing depth and clinical attachment level ≥ 4 mm at baseline. The treatment group exhibited a significantly greater decrease in disease activity score including 28 joints using C-reactive protein (DAS28-CRP) (P = 0.02), serum levels of IgG to P. gingivalis hemin binding protein (HBP)35 (P = 0.04), and citrulline (P = 0.02) than the control group. Serum levels of IgG to P. gingivalis HBP35 were significantly correlated positively with those of anti-cyclic citrullinated peptide antibodies (P = 0.0002). The same correlation was obtained between serum levels of IgG to P. gingivalis-sonicated extracts and those of rheumatoid factor (P = 0.02). These results suggest that supragingival scaling decreases DAS28-CRP and serum levels of IgG to P. gingivalis HBP35 and citrulline in patients with RA. These observations may reflect a role of P. gingivalis in the protein citrullination, which is related to the pathogenesis of RA.

  7. Interrelationships between glutamine and citrulline metabolism

    USDA-ARS?s Scientific Manuscript database

    This article analyzes the contribution of glutamine to the synthesis of citrulline and reviews the evidence that glutamine supplementation increases citrulline production. Glutamine supplementation has been proposed in the treatment of critically ill patients; however, a recent large multicenter ran...

  8. Association between PADI4 gene polymorphisms and anti-cyclic citrullinated peptide antibody positive rheumatoid arthritis in a large Chinese Han cohort.

    PubMed

    Du, Y; Liu, X; Guo, J-P; Liu, X; Li, R; Zhao, Y; Liu, X; Li, M-H; Li, Z-G

    2014-01-01

    The present study was undertaken to investigate the association of peptidyl-arginine-deiminase type IV gene (PADI4) single nucleotide polymorphisms (SNPs) with rheumatoid arthritis (RA) susceptibility, and to determine whether there is any impact of PADI4 polymorphisms on RA subsets or phenotypes in a large Chinese Han cohort. Two PADI4 SNPs (rs2240340 and rs1748033) were genotyped in 1216 Chinese Han RA patients and 1040 unaffected controls by TaqMan SNP Assays. Serum anti-CCP antibody and anti-PAD4 antibody levels were measured by ELISA. Bone destruction was scored by Sharp-van der Heijde scores (SHSs) of hands in 463 patients. The two SNPs rs2240340 and rs1748033 of PADI4 showed strong association with RA susceptibility (OR=1.23, 95% CI 1.09-1.38, p=6.66×10⁻⁴; and OR=1.24, 95% CI 1.10-1.41, p=6.98×10⁻⁴, respectively). RA risk genotypes of PADI4 were specifically associated with anti-CCP positive RA (rs2240340: p=5.13×10⁻⁶; rs1748033: p=2.97×10⁻³, respectively). Furthermore, there was a trend association between PADI4 rs2240340 and radiographic severity, though it did not reach the statistic significance (p=0.088). Our data provide strong evidence that PADI4 polymorphisms are risk factors contributed to RA susceptibility, especially for anti-CCP positive RA, and may confer higher risk of RA radiographic severity in Chinese Han population.

  9. Chemical Proteomic Platform To Identify Citrullinated Proteins

    PubMed Central

    2015-01-01

    Anti-citrullinated protein antibodies (ACPAs) are a hallmark of rheumatoid arthritis (RA) and are routinely used for disease diagnosis. Protein citrullination is also increased in cancer and other autoimmune disorders, suggesting that citrullinated proteins may serve as biomarkers for diseases beyond RA. To identify these citrullinated proteins, we developed biotin-conjugated phenylglyoxal (biotin-PG). Using this probe and our platform technology, we identified >50 intracellular citrullinated proteins. More than 20 of these are involved in RNA splicing, suggesting, for the first time, that citrullination modulates RNA biology. Overall, this chemical proteomic platform will play a key role in furthering our understanding of protein citrullination in rheumatoid arthritis and potentially a wider spectrum of inflammatory diseases. PMID:26360112

  10. Detection of autoantibodies to citrullinated BiP in rheumatoid arthritis patients and pro-inflammatory role of citrullinated BiP in collagen-induced arthritis

    PubMed Central

    2011-01-01

    Introduction Anti-citrullinated protein/peptide antibodies (ACPAs) are highly specific to rheumatoid arthritis (RA) patients and are thought to have a close relationship with the pathogenesis of arthritis. Several proteins, including fibrinogen, vimentin, and alpha-enolase, were reported as ACPA-target antigens, and their importance in RA pathogenesis was widely proposed. We identified citrullinated immunoglobulin binding protein (citBiP) as another ACPA target in RA patients and examined its pro-inflammatory role in arthritis. Methods We measured the levels of anti-citBiP, anti-BiP, and anti-cyclic citrullinated peptide (CCP) antibodies in the serum of RA patients (n = 100), systemic lupus erythematosus (SLE) patients (n = 60), and healthy controls (n = 30) using ELISA and immunoblotting. Epitope mapping was performed using 27 citBiP-derived peptides. In the mouse study, after DBA/1J mice were immunized with BiP or citBiP, serum titers of ACPAs were measured by ELISA and immunohistochemistry. The development of collagen-induced arthritis (CIA) was observed in BiP- or citBiP-pre-immunized mice. Results The serum levels of anti-BiP and anti-citBiP antibodies were significantly increased in RA patients, although only anti-BiP antibodies were slightly increased in SLE patients. Interestingly, anti-citBiP antibody levels were higher than anti-BiP antibody levels in 72% of RA patients, whereas no significant increase in anti-citBiP antibody levels was detected in SLE patients and healthy controls. The serum levels of anti-CCP antibodies were correlated with those of anti-citBiP antibodies in RA patients (R2 = 0.41). Several citrulline residues of citBiP were determined to be major epitopes of anti-citBiP antibodies, one of which showed cross-reactivity with CCP. Immunization of DBA/1J mice with citBiP induced several kinds of ACPAs, including anti-CCP and anti-citrullinated fibrinogen antibodies. Pre-immunization with citBiP exacerbated CIA, and anti-CCP antibody levels

  11. Interrelationships between glutamine and citrulline metabolism.

    PubMed

    Marini, Juan C

    2016-01-01

    This article analyzes the contribution of glutamine to the synthesis of citrulline and reviews the evidence that glutamine supplementation increases citrulline production. Glutamine supplementation has been proposed in the treatment of critically ill patients; however, a recent large multicenter randomized controlled trial resulted in increased mortality in the glutamine-supplemented group. Within this context, defining the contribution of glutamine to the production of citrulline, and thus to de-novo arginine synthesis, has become a pressing issue. The beneficial effects of glutamine supplementation may be partially mediated by the effects of glutamine on citrulline synthesis by the gut and the de-novo synthesis of arginine by the kidney and other tissues. Although there is no strong evidence to support that glutamine is a major precursor for citrulline synthesis in humans, glutamine has the potential to increase overall gut function and in this way increase citrulline production.

  12. Interrelationships between glutamine and citrulline metabolism

    PubMed Central

    2015-01-01

    Purpose of review To analyze the evidence that glutamine supplementation increases citrulline production. To determine the contribution of glutamine to the synthesis of citrulline. Recent findings Glutamine supplementation has been proposed in the treatment of critically ill patients; however, a recent large multicenter randomized controlled trial resulted in increased mortality in the glutamine supplemented group. Within this context, defining the contribution of glutamine to the production of citrulline, and thus to de novo arginine synthesis, has become a pressing issue. Summary The beneficial effects of glutamine supplementation may be partially mediated by the effects of glutamine on citrulline synthesis by the gut and the de novo synthesis of arginine by the kidney and other tissues. Although there is no strong evidence to support that glutamine is a major precursor for citrulline synthesis in humans, glutamine has the potential to increase overall gut function and in this way increase citrulline production. PMID:26560519

  13. Investigating citrullinated proteins in tumour cell lines

    PubMed Central

    2013-01-01

    Background The conversion of arginine into citrulline, termed citrullination, has important consequences for the structure and function of proteins. Studies have found PADI4, an enzyme performing citrullination, to be highly expressed in a variety of malignant tumours and have shown that PADI4 participates in the process of tumorigenesis. However, as citrullinated proteins have not been systematically investigated in tumours, the present study aimed to identify novel citrullinated proteins in tumours by 2-D western blotting (2-D WB). Methods Two identical two-dimensional electrophoresis (2-DE) gels were prepared using extracts from ECA, H292, HeLa, HEPG2, Lovo, MCF-7, PANC-1, SGC, and SKOV3 tumour cell lines. The expression profiles on a 2-DE gel were trans-blotted to PVDF membranes, and the blots were then probed with an anti-citrulline antibody. By comparing the 2-DE profile with the parallel 2-D WB profile at a global level, protein spots with immuno-signals were collected from the second 2-DE gel and identified using mass spectrometry. Immunoprecipitation was used to verify the expression and citrullination of the targeted proteins in tumour cell lines. Results 2-D WB and mass spectrometry identified citrullinated α-enolase (ENO1), heat shock protein 60 (HSP60), keratin 8 (KRT8), tubulin beta (TUBB), T cell receptor chain and vimentin in these cell lines. Immunoprecipitation analyses verified the expression and citrullination of ENO1, HSP60, KRT8, and TUBB in the total protein lysates of the tumour cell lines. Conclusions The citrullination of these proteins suggests a new mechanism in the tumorigenic process. PMID:24099319

  14. Diagnostic value of antibodies against a modified citrullinated vimentin in rheumatoid arthritis

    PubMed Central

    Dejaco, Christian; Klotz, Werner; Larcher, Heike; Duftner, Christina; Schirmer, Michael; Herold, Manfred

    2006-01-01

    Antibodies directed against citrullinated vimentin are members of the family of autoantibodies reactive with citrullinated proteins and are among the most specific serological markers for the diagnosis of rheumatoid arthritis (RA). This study was performed to test the diagnostic value of a newly developed enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against a genetically modified citrullinated vimentin (anti-MCV) in comparison with a second-generation anti-cyclic citrullinated peptides (anti-CCP2) ELISA test system. Blinded sera from 631 patients (409 consecutive out-patients and 222 randomly selected stored sera) with RA (n = 164) and non-RA (osteoarthritis [n = 120], polymyalgia rheumatica/giant cell arteritis [n = 80], spondyloarthritis [n = 36], and other inflammatory rheumatic or non-inflammatory disease [n = 67]) were tested for the presence of anti-MCV and anti-CCP2 antibodies according to the manufacturers' instructions. The diagnostic performance of the anti-MCV was comparable with the anti-CCP2 assay for the diagnosis of RA according to the calculated area under the curve (0.824; 95% confidence interval (CI) 0.778–0.870 versus 0.818; 95% CI 0.767–0.869) as analysed by receiving operating characteristic curve. When categorised with a cutoff value of 20.0 U/ml (as recommended by the manufacturer), sensitivity and specificity of the anti-MCV ELISA were 69.5% (95% CI 61.9%–76.5%) and 90.8% (86.9%–93.8%), respectively, compared with 70.1% (62.5%–77.0%) and 98.7% (96.7%–99.6%) of the anti-CCP2 assay. Using the cutoff values of 19.0 U/ml and 81.5 U/ml for the anti-MCV test to obtain a sensitivity and specificity identical to the anti-CCP2 assay, showed a reduced specificity (89.8%; 85.8%–92.9%) and sensitivity (53.7%; 45.7%–61.5%), respectively, of the anti-MCV ELISA compared with the anti-CCP2 test. In conclusion, the serum ELISA testing for anti-MCV antibodies as well as the anti-CCP-2 assay perform comparably well

  15. Hearing impairment in patients with rheumatoid arthritis: association with anti-citrullinated protein antibodies.

    PubMed

    Lobo, Fabrício Silva; Dossi, Mario Orlando; Batista, Lígia; Shinzato, Márcia Midori

    2016-09-01

    It has been suggested that hearing impairment (HI) is one of the extra-articular features of rheumatoid arthritis (RA). Nevertheless, the prevalence and nature of HI in RA is still uncertain. The objectives were to study hearing function in patients with RA using audiometric tests and to examine whether HI correlates with autoantibodies. Hearing functions were investigated in 43 consecutive RA patients and 23 control subjects (less than 60 years old). Their sera were evaluated for the presence of rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), and anti-mutated citrullinated vimentin (anti-MCV) antibodies. HI was observed in 46.5 % of RA patients and in 30.4 % of control subjects, p = 0.32. HI was characterized as sensorineural in 80 and 85.7 % of RA patients and control subjects with HI, respectively, p = 1.00. RA patients had a worse hearing threshold for air conduction at 6 kHz in the right ear (p = 0.019) and had a decreased amplitude of otoacoustic emissions (OAEs) at 2 kHz bilaterally (p = 0.04) compared with control subjects. In the RA group, patients with and without HI were 80 and 34.78 % anti-CCP positive, respectively, p = 0.008. RA patients with and without HI were 85 and 43.48 % anti-MCV positive, respectively, p = 0.013. HI in RA patients was mainly sensorineural and was associated with anti-CCP and anti-MCV antibodies.

  16. Influence of periodontal disease, Porphyromonas gingivalis and cigarette smoking on systemic anti-citrullinated peptide antibody titres.

    PubMed

    Lappin, David F; Apatzidou, Danae; Quirke, Anne-Marie; Oliver-Bell, Jessica; Butcher, John P; Kinane, Denis F; Riggio, Marcello P; Venables, Patrick; McInnes, Iain B; Culshaw, Shauna

    2013-10-01

    Anti-citrullinated protein antibody (ACPA) responses may precede clinical onset of rheumatoid arthritis. Porphyromonas gingivalis peptidylarginine deiminase can citrullinate proteins possibly inducing autoimmunity in susceptible individuals. To determine whether periodontitis, carriage of P. gingivalis, smoking and periodontal therapy influence ACPA titres. Serum and plaque samples were collected from 39 periodontitis patients before and after non-surgical periodontal treatment, and from 36 healthy subjects. Carriage of P. gingivalis was determined by PCR of plaque DNA. ACPA was determined by anti-cyclic citrullinated peptide (CCP) enzyme-linked immunosorbent assay (ELISA). Anti-P. gingivalis titres were determined by ELISA. Untreated periodontitis patients had higher anti-CCP antibody titres than healthy controls [three patients (8%) greater than manufacturer suggested assay diagnostic threshold (5 Assay Units/AU) versus none (0%); mean ± SEM: 1.37 ± 0.23 versus 0.40 ± 0.10 AU, p < 0.0001]. Periodontitis patients who smoked demonstrated lower anti-P. gingivalis (15956 ± 4385 versus 2512 ± 1290 Units/ml, p < 0.05), but similar anti-CCP than non-smoking periodontitis patients (smokers: 1.31 ± 0.35; non-smokers: 1.41 ± 0.32 AU). Healthy smokers demonstrated elevated anti-CCP titres (0.75 ± 0.19 AU), at levels between healthy non-smokers (0.15 ± 0.05 AU) and non-smoker periodontitis patients. Six months after periodontal treatment, there were significant reductions in anti-CCP (non-smokers p < 0.05) and anti-P. gingivalis (all participants p < 0.01). In subjects with periodontitis, P. gingivalis infection may be responsible for inducing autoimmune responses that characterize rheumatoid arthritis. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Anti-Citrullinated Protein Antibodies Are Associated With Neutrophil Extracellular Traps in the Sputum in Relatives of Rheumatoid Arthritis Patients.

    PubMed

    Demoruelle, M Kristen; Harrall, Kylie K; Ho, Linh; Purmalek, Monica M; Seto, Nickie L; Rothfuss, Heather M; Weisman, Michael H; Solomon, Joshua J; Fischer, Aryeh; Okamoto, Yuko; Kelmenson, Lindsay B; Parish, Mark C; Feser, Marie; Fleischer, Chelsie; Anderson, Courtney; Mahler, Michael; Norris, Jill M; Kaplan, Mariana J; Cherrington, Brian D; Holers, V Michael; Deane, Kevin D

    2017-06-01

    Studies suggest that rheumatoid arthritis (RA)-related autoimmunity is initiated at a mucosal site. However, the factors associated with the mucosal generation of this autoimmunity are unknown, especially in individuals who are at risk of future RA. Therefore, we tested anti-cyclic citrullinated peptide (anti-CCP) antibodies in the sputum of RA-free first-degree relatives (FDRs) of RA patients and patients with classifiable RA. We evaluated induced sputum and serum samples from 67 FDRs and 20 RA patients for IgA anti-CCP and IgG anti-CCP, with cutoff levels for positivity determined in a control population. Sputum was also evaluated for cell counts, neutrophil extracellular traps (NETs) using sandwich enzyme-linked immunosorbent assays for protein/nucleic acid complexes, and total citrulline. Sputum was positive for IgA and/or IgG anti-CCP in 14 of 20 RA patients (70%) and 17 of 67 FDRs (25%), including a portion of FDRs who were serum anti-CCP negative. In the FDRs, elevations of sputum IgA and IgG anti-CCP were associated with elevated sputum cell counts and NET levels. IgA anti-CCP was associated with ever smoking and with elevated sputum citrulline levels. Anti-CCP is elevated in the sputum of FDRs, including seronegative FDRs, suggesting that the lung may be a site of anti-CCP generation in this population. The association of anti-CCP with elevated cell counts and NET levels in FDRs supports a hypothesis that local airway inflammation and NET formation may drive anti-CCP production in the lung and may promote the early stages of RA development. Longitudinal studies are needed to follow the evolution of these processes relative to the development of systemic autoimmunity and articular RA. © 2017, American College of Rheumatology.

  18. Intestinal and hepatic metabolism of glutamine and citrulline in humans

    PubMed Central

    van de Poll, Marcel C G; Ligthart-Melis, Gerdien C; Boelens, Petra G; Deutz, Nicolaas E P; van Leeuwen, Paul A M; Dejong, Cornelis H C

    2007-01-01

    Glutamine plays an important role in nitrogen homeostasis and intestinal substrate supply. It has been suggested that glutamine is a precursor for arginine through an intestinal–renal pathway involving inter-organ transport of citrulline. The importance of intestinal glutamine metabolism for endogenous arginine synthesis in humans, however, has remained unaddressed. The aim of this study was to investigate the intestinal conversion of glutamine to citrulline and the effect of the liver on splanchnic citrulline metabolism in humans. Eight patients undergoing upper gastrointestinal surgery received a primed continuous intravenous infusion of [2-15N]glutamine and [ureido-13C–2H2]citrulline. Arterial, portal venous and hepatic venous blood were sampled and portal and hepatic blood flows were measured. Organ specific amino acid uptake (disposal), production and net balance, as well as whole body rates of plasma appearance were calculated according to established methods. The intestines consumed glutamine at a rate that was dependent on glutamine supply. Approximately 13% of glutamine taken up by the intestines was converted to citrulline. Quantitatively glutamine was the only important precursor for intestinal citrulline release. Both glutamine and citrulline were consumed and produced by the liver, but net hepatic flux of both amino acids was not significantly different from zero. Plasma glutamine was the precursor of 80% of plasma citrulline and plasma citrulline in turn was the precursor of 10% of plasma arginine. In conclusion, glutamine is an important precursor for the synthesis of arginine after intestinal conversion to citrulline in humans. PMID:17347276

  19. Glutamine: precursor or nitrogen donor for citrulline synthesis?

    PubMed Central

    Didelija, Inka Cajo; Castillo, Leticia; Lee, Brendan

    2010-01-01

    Although glutamine is considered the main precursor for citrulline synthesis, the current literature does not differentiate between the contribution of glutamine carbon skeleton vs. nonspecific nitrogen (i.e., ammonia) and carbon derived from glutamine oxidation. To elucidate the role of glutamine and nonspecific nitrogen in the synthesis of citrulline, l-[2-15N]- and l-[5-15N]glutamine and 15N-ammonium acetate were infused intragastrically in mice. The amino group of glutamine labeled the three nitrogen groups of citrulline almost equally. The amido group and ammonium acetate labeled the ureido and amino groups of citrulline, but not the δ-nitrogen. D5-glutamine also infused in this arm of the study, which traces the carbon skeleton of glutamine, was utilized poorly, accounting for only 0.2–0.4% of the circulating citrulline. Dietary glutamine nitrogen (both N groups) incorporation was 25-fold higher than the incorporation of its carbon skeleton into citrulline. To investigate the relative contributions of the carbon skeleton and nonspecific carbon of glutamine, arginine, and proline to citrulline synthesis, U-13Cn tracers of these amino acids were infused intragastrically. Dietary arginine was the main precursor for citrulline synthesis, accounting for ∼40% of the circulating citrulline. Proline contribution was minor (3.4%), and glutamine was negligible (0.4%). However, the glutamine tracer resulted in a higher enrichment in the ureido group, indicating incorporation of nonspecific carbon from glutamine oxidation into carbamylphosphate used for citrulline synthesis. In conclusion, dietary glutamine is a poor carbon skeleton precursor for the synthesis of citrulline, although it contributes both nonspecific nitrogen and carbon to citrulline synthesis. PMID:20407005

  20. Anti-citrullinated peptide antibodies in the serum of heavy smokers without rheumatoid arthritis. A differential effect of chronic obstructive pulmonary disease?

    PubMed

    Ruiz-Esquide, Virginia; Gómara, María José; Peinado, Víctor I; Gómez Puerta, José Alfredo; Barberá, Joan Albert; Cañete, Juan de Dios; Haro, Isabel; Sanmartí, Raimon

    2012-07-01

    The objective of this study is to analyse the frequency and levels of anti-citrullinated peptide/protein antibodies (ACPA) in the serum of non-rheumatoid arthritis (RA) heavy smokers with and without chronic obstructive pulmonary disease (COPD) and compare them with healthy never smokers and patients with RA. Serum samples of 110 heavy smokers without RA, 209 healthy never smokers and 134 patients with RA were tested for ACPA using a commercial anti-cyclic citrullinated peptide antibodies (CCP2) test and a homemade chimeric fibrin/filaggrin citrullinated synthetic peptide (anti-CFFCP) ELISA test. The frequency of positive results and autoantibody levels were compared between groups. The prevalence of the two types of ACPA was slightly higher in heavy smokers than in never smokers, although the difference was not significant, and significantly lower than in RA patients. The highest prevalence of positive ACPA in heavy smokers was found in subjects with COPD (7.4% of positive anti-CFFCP in patients with COPD in comparison with 2.4% in never smokers: OR 3.26; 95% CI 0.85-12.6, p = 0.089). Mean serum levels of ACPA in heavy smokers were not significantly different from those of never smokers. Heavy smokers with COPD had significantly higher levels of anti-CFFCP than those without COPD, although almost all patients had serum levels below the cut-off values. The prevalence of ACPA in heavy smokers without RA is low, but seems to be higher in heavy smokers with COPD. Larger studies are necessary to confirm these findings and determine the relationship between ACPA and lung disease.

  1. IgG1 and IgG4 are the predominant subclasses among auto-antibodies against two citrullinated antigens in RA.

    PubMed

    Engelmann, R; Brandt, J; Eggert, M; Karberg, K; Krause, A; Neeck, G; Mueller-Hilke, B

    2008-10-01

    Antibody subclasses reflect specific immunological processes and may be indicative of the underlying pathological pattern in an autoimmune disease like RA. We therefore quantified anti-cyclic citrullinated peptides (CCP) and anti- citrullinated vimentin (MCV) IgG subclass titres in RA patients and compared them with the respective titres of antibodies directed against the varicella zoster virus (VZV) and to total serum titres. Sera of 77 patients fulfilling the ACR criteria for RA were collected. An IgG subclass-specific ELISA system was then established and combined with commercially available MCV, CCP and VZV pre-coated microtitre plates. Even though IgG1 is the predominant subclass among antibodies against CCP and MCV in RA patients, IgG4 is second with respect to titres and frequencies. This increase in IgG4 among RA-specific antibodies is independent of disease duration and does not reflect a general skewing of the immune response in these patients as overall serum titres and antibodies directed against VZV show a normal distribution of IgG1, IgG2, IgG3 and IgG4. Elevated IgG4 titres are specific for auto-antibodies against citrullinated antigens in RA and are indicative of a Th2-biased environment during the generation of auto-reactive plasma cells. We discuss here an indirect role for IgG4 auto-antibodies in hindering the elimination of auto-reactive B and plasma cells and thus driving the autoimmune process.

  2. Prediction of radiological outcome in early rheumatoid arthritis in clinical practice: role of antibodies to citrullinated peptides (anti-CCP)

    PubMed Central

    Forslind, K; Ahlmen, M; Eberhardt, K; Hafstrom, I; Svensson, B

    2004-01-01

    Objective: To investigate the role of anti-cyclic citrullinated peptide antibody (anti-CCP) for the prediction of radiological outcome in patients with early rheumatoid arthritis. Methods: Anti-CCP was assessed at baseline in 379 patients with early rheumatoid arthritis (disease duration <1 year). Radiological joint damage and progression were assessed by Larsen score after two years of follow up (end point) and used as outcome variables. The prognostic value of anti-CCP and other demographic and disease related baseline variables were assessed by univariate and multivariate analyses, including calculation of odds ratios (OR), predictive values, and multiple logistic regression models. Results: The presence of anti-CCP was associated with significantly higher Larsen score both at baseline and at end point. Univariate predictor analysis showed that anti-CCP had the highest significant OR for radiological joint damage and progression after baseline Larsen score, followed by rheumatoid factor, erythrocyte sedimentation rate (ESR), C reactive protein, age, smoking status, and sex. In stepwise multiple regression analyses, baseline Larsen score, anti-CCP, and ESR were selected as significant independent predictors of the radiological outcomes. Conclusions: There is good evidence for an association of anti-CCP with radiological joint changes in rheumatoid arthritis. Anti-CCP is an independent predictor of radiological damage and progression. Though prediction in early rheumatoid arthritis is still far from perfect, the use of anti-CCP in clinical practice should make it easier for rheumatologists to reach judicious treatment decisions. PMID:15308518

  3. Extrarenal citrulline disposal in mice with impaired renal function

    USDA-ARS?s Scientific Manuscript database

    The endogenous synthesis of arginine, a semiessential amino acid, relies on the production of citrulline by the gut and its conversion into arginine by the kidney in what has been called the "intestinal-renal axis" for arginine synthesis. Although the kidney is the main site for citrulline disposal,...

  4. Enteral arginase II provides ornithine for citrulline synthesis

    USDA-ARS?s Scientific Manuscript database

    The synthesis of citrulline from arginine in the small intestine depends on the provision of ornithine. To test the hypothesis that arginase II plays a central role in the supply of ornithine for citrulline synthesis, the contribution of dietary arginine, glutamine, and proline was determined by uti...

  5. Antibodies to Citrullinated Protein Antigens (ACPAs): Clinical and Pathophysiologic Significance

    PubMed Central

    Demoruelle, M. Kristen; Deane, Kevin

    2014-01-01

    Antibodies to citrullinated protein antigens (ACPAs) are highly specific for rheumatoid arthritis (RA) and are useful in the diagnosis of RA as well as the prediction of the course and outcomes of disease. Multiple methodologies exist for measuring ACPAs, including the widely available tests for anticyclic citrullinated peptide antibodies and for antibodies to mutated/modified citrullinated vimentin. These methodologies overall have similar diagnostic accuracies for RA, although there is some variability. The discovery of ACPAs and the biology of citrullination have also led to important advances in the understanding of the pathophysiology and development of RA, especially regarding the relationship between potential genetic and environmental risk factors for RA. Going forward, research into autoimmunity to citrullinated proteins may help identify the specific etiology of RA and provide approaches for the prediction of future risk of disease, and ultimately prevention of RA. PMID:21713412

  6. The prevalence of ANA antibodies, anticentromere antibodies, and anti-cyclic citrullinated peptide antibodies in patients with primary Sjögren's syndrome compared to patients with dryness symptoms without primary Sjögren's syndrome confirmation.

    PubMed

    Maślińska, Maria; Mańczak, Małgorzata; Wojciechowska, Bożena; Kwiatkowska, Brygida

    2017-01-01

    Our study analyses the prevalence of ANA, anti-SS-A, anti-SS-B, and ACA and ACPA antibodies in patients with pSS and with dryness symptoms without pSS confirmation, and the association of ACPA and ACA antibodies with specific clinical symptoms. 113 patients were divided into two groups: I - with diagnosed pSS (N = 75); and II - with dryness without pSS evidence (N = 38). Diagnostics: indirect immunofluorescence (IF; Hep-2 cell line) of antinuclear antibodies (ANA), anti-SS-A anti-SS-B antibodies determined with semi-quantitative method, autoantibody profile (14 antigens, ANA Profil 3 EUROLINE); basic laboratory, ophthalmic examination tests, minor salivary gland biopsy with focus score (FS), joint and lung evaluation, and ESSDAI questionnaire (pSS activity). 88% of group I had ANA antibodies (1 : 320 titre), 5.3% at 1 : 160. Anti-SS-A antibodies were present in 88% of group I, including all ANA 1 : 160. Anti-SS-A antibodies positively correlated with greater and moderate activity of ESSDAI 5 (p = 0.046) and FS. The presence of SS-B antibodies significantly affected disease activity. ACPA present: group I - 13% (associated with higher arthritis incidence; p = 0.003); group II - 8%. ACA antibodies present in 4% of group I, but not in group II. No ACA association with interstitial lung changes (small ACA + group excludes full conclusions). ANA antibodies should also be considered in a titre of less than 1 : 320, but the presence of anti-SS-A antibodies is still the most important immunological marker for pSS. Anti-SS-A antibodies correlate with higher disease activity (ESSDAI ≥ 5) and higher FS. The presence of the anti-SS-B antibody was significantly affected by higher activity of the disease. The incidence of arthritis was higher in patients with ACPA+ pSS compared to ACPA- (p = 0.003). There was no relationship between ACPA and arthritis in patients with dry-type syndrome without diagnosis of pSS.

  7. Lower omega-3 fatty acids are associated with the presence of anti-cyclic citrullinated peptide autoantibodies in a population at risk for future rheumatoid arthritis: a nested case-control study

    PubMed Central

    Gan, Ryan W.; Young, Kendra A.; Zerbe, Gary O.; Demoruelle, M. Kristen; Weisman, Michael H.; Buckner, Jane H.; Gregersen, Peter K.; Mikuls, Ted R.; O’Dell, James R.; Keating, Richard M.; Clare-Salzler, Michael J.; Deane, Kevin D.; Holers, V. Michael

    2016-01-01

    Objective. The aim of this study was to investigate omega-3 fatty acid (FA) supplement use and omega-3 FAs in erythrocyte membranes [omega-3 FA % in erythrocyte membranes (RBC)] and their association with anti-CCP autoantibodies in a population without RA, but who are at genetic risk for RA. Methods. The multicentre Studies of the Etiology of RA (SERA) cohort includes RA-free subjects who are first-degree relatives of RA probands or are enriched with the HLA-DR4 allele. In a nested case-control study, 30 SERA cases were identified who were anti-CCP2 antibody positive. We further identified 47 autoantibody negative controls, frequency matched to cases on age at study visit, sex, race and study site. Anti-CCP2 status, self-reported omega-3 FA supplement use and omega-3 FA % in RBCs were obtained from a single visit. Results. Anti-CCP2 positive cases were less likely than controls to report omega-3 FA supplement use (odds ratio: 0.14; 95% CI 0.03, 0.68). In addition, the likelihood of anti-CCP2 positivity was inversely associated with total omega-3 FA % in RBCs (odds ratio: 0.47; 95% CI 0.24, 0.92, for a s.d. increase). Conclusion. The inverse association between anti-CCP2 positivity and self-reported omega-3 FA supplement use and omega-3 FA % in RBCs suggests that omega-3 FAs may protect against the development of RA-related autoimmunity in pre-clinical RA. PMID:26370400

  8. Lower omega-3 fatty acids are associated with the presence of anti-cyclic citrullinated peptide autoantibodies in a population at risk for future rheumatoid arthritis: a nested case-control study.

    PubMed

    Gan, Ryan W; Young, Kendra A; Zerbe, Gary O; Demoruelle, M Kristen; Weisman, Michael H; Buckner, Jane H; Gregersen, Peter K; Mikuls, Ted R; O'Dell, James R; Keating, Richard M; Clare-Salzler, Michael J; Deane, Kevin D; Holers, V Michael; Norris, Jill M

    2016-02-01

    The aim of this study was to investigate omega-3 fatty acid (FA) supplement use and omega-3 FAs in erythrocyte membranes [omega-3 FA % in erythrocyte membranes (RBC)] and their association with anti-CCP autoantibodies in a population without RA, but who are at genetic risk for RA. The multicentre Studies of the Etiology of RA (SERA) cohort includes RA-free subjects who are first-degree relatives of RA probands or are enriched with the HLA-DR4 allele. In a nested case-control study, 30 SERA cases were identified who were anti-CCP2 antibody positive. We further identified 47 autoantibody negative controls, frequency matched to cases on age at study visit, sex, race and study site. Anti-CCP2 status, self-reported omega-3 FA supplement use and omega-3 FA % in RBCs were obtained from a single visit. Anti-CCP2 positive cases were less likely than controls to report omega-3 FA supplement use (odds ratio: 0.14; 95% CI 0.03, 0.68). In addition, the likelihood of anti-CCP2 positivity was inversely associated with total omega-3 FA % in RBCs (odds ratio: 0.47; 95% CI 0.24, 0.92, for a s.d. increase). The inverse association between anti-CCP2 positivity and self-reported omega-3 FA supplement use and omega-3 FA % in RBCs suggests that omega-3 FAs may protect against the development of RA-related autoimmunity in pre-clinical RA. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. [Significance of antibodies to the citrullinated glucose-6-phosphate isomerase peptides in rheumatoid arthritis].

    PubMed

    Wu, D; Sun, L; Li, C H; Yang, L; Zhao, J X; Liu, X Y

    2016-12-18

    To detect the anti-citrullinated glucose-6-phosphate isomerase (GPI) 70-88 peptide antibody (anti-C-GPI(70-88) antibody), anti-citrullinated GPI 435-453 peptide antibody (anti-C-GPI(435-453) antibody), anti-GPI 70-88 peptide antibody (anti-GPI(70-88) antibody) and anti-GPI 435-453 peptide antibody(anti-GPI(435-453) antibody) in the serum of rheumatoid arthritis (RA) patients, and examine the diagnostic values of the anti-C-GPI peptide antibodies in RA. The anti-C-GPI(70-88) antibody, anti-C-GPI(435-453) antibody, anti-GPI(70-88) antibody and anti-GPI(435-453) antibody were detected by enzyme-linked immunosorbent assay (ELISA) in 191 RA patients, 129 other rheumatic diseases and 74 healthy controls. The clinical and laboratory data of the patients with RA were collected, and the values of anti-C-GPI peptide antibodies in the diagnosis of RA and the relationships of anti-C-GPI peptide antibodies with the clinical and laboratory parameters analyzed. (1) The mean titers of the anti-C-GPI(70-88) antibody and the anti-C-GPI(435-453) antibody in the RA patients (respectively, 68.71 ± 4.20 and 51.78 ± 3.13) were significantly higher than those with other rheumatic diseases and healthy individuals (P <0.05). However, the mean titers of the anti-GPI(70-88) antibody and anti-GPI(435-453) antibody in the RA patients were similar to those with other rheumatic diseases and healthy individuals. (2) The diagnostic sensitivity and specificity of the anti-C-GPI(70-88) antibody for RA were 41.88% and 84.50% respectively; and the diagnostic sensitivity and specificity of the anti-C-GPI(435-453) antibody for RA were 46.05% and 86.05% respectively. The sensitivity of combined detection of the two anti-C-GPI peptide antibodies was 50.79%, and the specificity was 81.40%. (3) The positive rates of the anti-C-GPI(70-88) antibody and the anti-C-GPI(435-453) antibody were 35% and 45% respectively in those patients with negative anti-cyclic citrullinated peptide antibody, anti

  10. Citrullination and carbamylation in the pathophysiology of rheumatoid arthritis.

    PubMed

    Pruijn, Ger J M

    2015-01-01

    The discovery that citrullination was crucial for the recognition of antigens by the most disease-specific class of autoantibodies in rheumatoid arthritis (RA) had a huge impact on studies aimed at understanding autoimmunity in this disease. In addition to the detailed characterization of anti-citrullinated protein antibodies, various studies have addressed the identity of citrullinated antigens. These investigations were facilitated by new methods to characterize these proteins, the analysis of protein citrullination by peptidylarginine deiminases, the generation of a catalog of citrullinated proteins present in the inflamed joints of patients and the finding that the formation of extracellular traps is dependent on the activity of peptidylarginine deiminase activity. Recently, it was found that in addition to citrullination also carbamylation, which results in chemically highly related modified proteins, yields antigens that are targeted by rheumatoid arthritis patient sera. Here, all of these aspects will be discussed, culminating in current ideas about the involvement of citrullination and carbamylation in pathophysiological processes in autoimmunity, especially RA.

  11. Arginine and citrulline supplementation in sports and exercise: ergogenic nutrients?

    PubMed

    Sureda, Antoni; Pons, Antoni

    2012-01-01

    Dietary L-citrulline malate supplements may increase levels of nitric oxide (NO) metabolites, although this response has not been related to an improvement in athletic performance. NO plays an important role in many functions in the body regulating vasodilatation, blood flow, mitochondrial respiration and platelet function. L-Arginine is the main precursor of NO via nitric oxide synthase (NOS) activity. Additionally, L-citrulline has been indicated to be a second NO donor in the NOS-dependent pathway, since it can be converted to L-arginine. The importance of L-citrulline as an ergogenic support derives from the fact that L-citrulline is not subject to pre-systemic elimination and, consequently, could be a more efficient way to elevate extracellular levels of L-arginine by itself. L-Citrulline malate can develop beneficial effects on the elimination of NH(3) in the course of recovery from exhaustive muscular exercise and also as an effective precursor of L-arginine and creatine. Dietary supplementation with L-citrulline alone does not improve exercise performance. The ergogenic response of L-citrulline or L-arginine supplements depends on the training status of the subjects. Studies involving untrained or moderately healthy subjects showed that NO donors could improve tolerance to aerobic and anaerobic exercise. However, when highly-trained subjects were supplemented, no positive effect on performance was indicated. Copyright © 2012 S. Karger AG, Basel.

  12. Differences in the Spectrum of Anti-Citrullinated Protein Antibody Fine Specificities Between Malaysian and Swedish Patients With Rheumatoid Arthritis: Implications for Disease Pathogenesis.

    PubMed

    Too, Chun Lai; Murad, Shahnaz; Hansson, Monika; Alm, Linda Mathsson; Dhaliwal, Jasbir Singh; Holmdahl, Rikard; Jakobsson, Per-Johan; Alfredsson, Lars; Klareskog, Lars; Rönnelid, Johan; Padyukov, Leonid

    2017-01-01

    Antibodies to the citrullinated protein antigens (ACPAs) are important in the diagnosis and pathogenesis of rheumatoid arthritis (RA). However, the prevalence of ACPAs with different fine specificities in different populations is unclear. This study sought to examine the fine specificity of the antibody responses toward citrullinated proteins in RA patients from Malaysia, an area where genetic and environmental determinants of RA are different from those in more frequently studied cohorts of Caucasian subjects. A multiplex analytic microarray system was used to analyze the occurrence of antibodies to 10 different citrullinated peptides (filaggrin [fil307-324], vimentin [Vim2-17, Vim60-75], fibrinogen [Fibα563-583, Fibα580-600, Fibβ36-52, Fibβ62-81a, Fibβ62-81b], enolase [Eno5-21], and type II collagen [CitCII355-378]) in serum samples from 4,089 RA patients (1,231 Malaysian and 2,858 Swedish) and 827 healthy control subjects (249 Malaysian and 578 Swedish). The positive reaction threshold for each peptide was set separately for each population based on a specificity of 98%. Distinct differences in the frequencies of 5 ACPA fine specificities (Vim60-75, Vim2-17, Fibβ62-81b, Eno5-21, and CitCII355-378) were found between the Malaysian and Swedish RA populations, despite a nearly identical percentage of patients in each population who were positive for anti-cyclic citrullinated peptide 2 antibodies. In Malaysian RA patients compared with Swedish RA patients, the frequencies of antibodies to Vim60-75 (54% versus 44%, corrected P [Pcorr ] = 1.06 × 10(-8) ) and CitCII355-378 (17% versus 13%, Pcorr  = 0.02) were significantly higher, while the frequencies of antibodies to Vim2-17 (25% versus 32%, Pcorr  = 1.91 × 10(-4) ), Fibβ62-81b (15% versus 30%, Pcorr  = 2.47 × 10(-22) ), and Eno5-21 (23% versus 50%, Pcorr  = 3.64 × 10(-57) ) were significantly lower. Serum ACPA fine specificities differ between RA patients in different populations

  13. VIRULENCE AND CITRULLINE UREIDASE ACTIVITY OF PASTEURELLA TULARENSIS12

    PubMed Central

    Marchette, Nyven J.; Nicholes, Paul S.

    1961-01-01

    Marchette, Nyven J. (University of Utah, Salt Lake City), and Paul S. Nicholes. Virulence and citrulline ureidase activity of Pasteurella tularensis. J. Bacteriol. 82:26–32. 1961.—The presence of a citrulline ureidase system in Pasteurella tularensis strains of high virulence, and its absence in avirulent strains and strains of low virulence was confirmed. The presence of this system, however, was shown to be not directly related to virulence. The only wild strain of P. tularensis tested that lacked a citrulline ureidase system was isolated from a rodent. All the strains, isolated from rabbits, rabbit ticks, a human being, and a horse, that were tested possessed this system. The existence of two North American varieties of P. tularensis was postulated on the basis of virulence and citrulline ureidase activity. PMID:13766500

  14. Virulence and citrulline ureidase activity of Pasteurella tularensis.

    PubMed

    MARCHETTE, N J; NICHOLES, P S

    1961-07-01

    Marchette, Nyven J. (University of Utah, Salt Lake City), and Paul S. Nicholes. Virulence and citrulline ureidase activity of Pasteurella tularensis. J. Bacteriol. 82:26-32. 1961.-The presence of a citrulline ureidase system in Pasteurella tularensis strains of high virulence, and its absence in avirulent strains and strains of low virulence was confirmed. The presence of this system, however, was shown to be not directly related to virulence. The only wild strain of P. tularensis tested that lacked a citrulline ureidase system was isolated from a rodent. All the strains, isolated from rabbits, rabbit ticks, a human being, and a horse, that were tested possessed this system. The existence of two North American varieties of P. tularensis was postulated on the basis of virulence and citrulline ureidase activity.

  15. Smoking is associated with the concurrent presence of multiple autoantibodies in rheumatoid arthritis rather than with anti-citrullinated protein antibodies per se: a multicenter cohort study.

    PubMed

    van Wesemael, Tineke J; Ajeganova, Sofia; Humphreys, Jennifer; Terao, Chikashi; Muhammad, Ammar; Symmons, Deborah P M; MacGregor, Alex J; Hafström, Ingiäld; Trouw, Leendert A; van der Helm-van Mil, Annette H M; Huizinga, Tom W J; Mimori, Tsuneyo; Toes, René E M; Matsuda, Fumihiko; Svensson, Björn; Verstappen, Suzanne M M; van der Woude, Diane

    2016-12-01

    The contribution of smoking to rheumatoid arthritis (RA) is hypothesized to be mediated through formation of anti-citrullinated protein antibodies (ACPA). In RA, however, autoantibodies such as ACPA, rheumatoid factor (RF), and anti-carbamylated protein antibodies (anti-CarP) often occur together, and it is thus unclear whether smoking is specifically associated with some autoantibodies rather than others. We therefore investigated whether smoking is only associated with ACPA or with the presence of multiple RA-related autoantibodies. A population-based Japanese cohort (n = 9575) was used to investigate the association of smoking with RF and anti-cyclic citrullinated peptide antibodies (anti-CCP2) in individuals without RA. Furthermore, RA patients fulfilling the 1987 criteria from three early arthritis cohorts from the Netherlands (n = 678), the United Kingdom (n = 761), and Sweden (n = 795) were used. Data on smoking, RF, anti-CCP2, and anti-CarP were available. A total score of autoantibodies was calculated, and odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated by logistic regression. In the population-based non-RA cohort, no association was found between smoking and one autoantibody (RF or anti-CCP2), but smoking was associated with double-autoantibody positivity (OR 2.95, 95% CI 1.32-6.58). In RA patients, there was no association between smoking and the presence of one autoantibody (OR 0.99, 95% CI 0.78-1.26), but smoking was associated with double-autoantibody positivity (OR 1.32, 95% CI 1.04-1.68) and triple-autoantibody positivity (OR 2.05, 95% CI 1.53-2.73). Smoking is associated with the concurrent presence of multiple RA-associated autoantibodies rather than just ACPA. This indicates that smoking is a risk factor for breaking tolerance to multiple autoantigens in RA.

  16. Plasma citrulline measurement in the diagnosis of acute mesenteric ischaemia.

    PubMed

    Kulu, Rıdvan; Akyildiz, Hizir; Akcan, Alper; Oztürk, Ahmet; Sozuer, Erdogan

    2017-09-01

    The differential diagnosis in acute mesenteric ischaemia (AMI) is essential and sometimes life-saving. A marker for early diagnosis is lacking. Citrulline is an amino acid mainly synthesized by small bowel enterocytes from glutamine. In this study, we aimed to evaluate the diagnostic and prognostic values of citrulline with those of the D-dimer in patients with AMI. The patients were divided into two groups; group 1: patients with acute abdominal findings which were attributed preoperatively to AMI, and group 2: patients with acute abdominal findings which were attributed preoperatively to causes other than AMI. All patients underwent surgical exploration. Blood samples were taken before surgery. The demographic features, laboratory examinations, citrulline concentration, D-dimer level and surgical findings were evaluated. Overall, 48 patients were enrolled in the study. AMI was diagnosed in 23 of the 48 patients. There was no significant difference between the groups with regard to gender, leucocyte count and creatinine levels but group 1 was significantly older than group 2. Citrulline, D-dimer and lactate levels were also significantly higher in group 1. Age, lactate, D-dimer and citrulline levels were statistically significant for mortality. The most significant factor was increased lactate level at admission. Plasma citrulline level may be helpful in the diagnosis of patients with AMI. © 2016 Royal Australasian College of Surgeons.

  17. Citrullinated vimentin as an important antigen in immune complexes from synovial fluid of rheumatoid arthritis patients with antibodies against citrullinated proteins

    PubMed Central

    2010-01-01

    Introduction Rheumatoid arthritis (RA) is an inflammatory disease, which results in destruction of the joint. The presence of immune complexes (IC) in serum and synovial fluid of RA patients might contribute to this articular damage through different mechanisms, such as complement activation. Therefore, identification of the antigens from these IC is important to gain more insight into the pathogenesis of RA. Since RA patients have antibodies against citrullinated proteins (ACPA) in their serum and synovial fluid (SF) and since elevated levels of citrullinated proteins are detected in the joints of RA patients, citrullinated antigens are possibly present in IC from RA patients. Methods IC from serum of healthy persons, serum of RA patients and IC from synovial fluid of RA patients and Spondyloarthropathy (SpA) patients were isolated by immunoprecipitation. Identification of the antigens was performed by SDS-PAGE, mass spectrometry and immunodetection. The presence of citrullinated proteins was evaluated by anti-modified citrulline (AMC) staining. Results Circulating IC in the serum of RA patients and healthy controls contain fibrinogenβ and fibronectin, both in a non-citrullinated form. Additionally, in IC isolated from RA SF, fibrinogenγ and vimentin were identified as well. More importantly, vimentin and a minor portion of fibrinogenβ were found to be citrullinated in the isolated complexes. Moreover these citrullinated antigens were only found in ACPA+ patients. No citrullinated antigens were found in IC from SF of SpA patients. Conclusions Citrullinated fibrinogenβ and citrullinated vimentin were found in IC from SF of ACPA+ RA patients, while no citrullinated antigens were found in IC from SF of ACPA- RA patients or SpA patients or in IC from serum of RA patients or healthy volunteers. The identification of citrullinated vimentin as a prominent citrullinated antigen in IC from SF of ACPA+ RA patients strengthens the hypothesis that citrullinated vimentin

  18. Differences in synovial fluid cytokine levels but not in synovial tissue cell infiltrate between anti-citrullinated peptide/protein antibody-positive and –negative rheumatoid arthritis patients

    PubMed Central

    2013-01-01

    Introduction Comparative data on synovial cell infiltrate and cytokine levels in anti citrullinated peptide/protein antibody (ACPA)-positive and ACPA negative rheumatoid arthritis (RA) patients are scarce. Our aim was to analyze synovial cell infiltrate and synovial fluid (SF) levels of cytokines in patients with RA according to the presence or absence of ACPA in serum. Methods A cross-sectional study in a single center including consecutive RA patients was performed. Patients were defined as 'ACPA negative' if serum was negative to two different ACPAs [second generation commercial anti-cyclic citrullinated peptide antibodies (CCP2) and chimeric fibrin/filaggrin citrullinated antibodies]. Parallel synovial tissue (ST) biopsies and SF were obtained by knee arthroscopy. Synovial cell infiltrate and endothelial cells were analyzed by immunohistochemistry and SF levels of Th1, Th2, Th17 and pro-inflammatory cytokines by Quantibody(R) Human Array. Results A total of 83 patients underwent arthroscopy, with a mean age of 55.9 ± 12 years, and mean disease duration of 45 months (interquartile range, IQR 10.8 to 122). 62% were female and 77% were ACPA positive. No significant differences were found in clinical variables, acute phase reactants, synovial cell infiltrate or lymphoid neogenesis (LN) between ACPA positive and negative patients. However ACPA positive patients had significantly higher levels of IL-1β, IL-10, IL-17 F and CC chemokine ligand 20 (CCL-20) than ACPA negative patients. Conclusions In our cohort of patients with RA no significant differences were found in synovial cell infiltrate or synovial LN according to ACPA status. However, ACPA positive patients had higher levels of T-cell derived and pro-inflammatory cytokines than ACPA negative patients. As systemic and local inflammation was similar in the two groups, these findings support a distinct synovial physiopathology. PMID:24485167

  19. Citrullination regulates pluripotency and histone H1 binding to chromatin

    NASA Astrophysics Data System (ADS)

    Christophorou, Maria A.; Castelo-Branco, Gonçalo; Halley-Stott, Richard P.; Oliveira, Clara Slade; Loos, Remco; Radzisheuskaya, Aliaksandra; Mowen, Kerri A.; Bertone, Paul; Silva, José C. R.; Zernicka-Goetz, Magdalena; Nielsen, Michael L.; Gurdon, John B.; Kouzarides, Tony

    2014-03-01

    Citrullination is the post-translational conversion of an arginine residue within a protein to the non-coded amino acid citrulline. This modification leads to the loss of a positive charge and reduction in hydrogen-bonding ability. It is carried out by a small family of tissue-specific vertebrate enzymes called peptidylarginine deiminases (PADIs) and is associated with the development of diverse pathological states such as autoimmunity, cancer, neurodegenerative disorders, prion diseases and thrombosis. Nevertheless, the physiological functions of citrullination remain ill-defined, although citrullination of core histones has been linked to transcriptional regulation and the DNA damage response. PADI4 (also called PAD4 or PADV), the only PADI with a nuclear localization signal, was previously shown to act in myeloid cells where it mediates profound chromatin decondensation during the innate immune response to infection. Here we show that the expression and enzymatic activity of Padi4 are also induced under conditions of ground-state pluripotency and during reprogramming in mouse. Padi4 is part of the pluripotency transcriptional network, binding to regulatory elements of key stem-cell genes and activating their expression. Its inhibition lowers the percentage of pluripotent cells in the early mouse embryo and significantly reduces reprogramming efficiency. Using an unbiased proteomic approach we identify linker histone H1 variants, which are involved in the generation of compact chromatin, as novel PADI4 substrates. Citrullination of a single arginine residue within the DNA-binding site of H1 results in its displacement from chromatin and global chromatin decondensation. Together, these results uncover a role for citrullination in the regulation of pluripotency and provide new mechanistic insights into how citrullination regulates chromatin compaction.

  20. CCP

    MedlinePlus

    ... services. Advertising & Sponsorship: Policy | Opportunities Cyclic Citrullinated Peptide Antibody Share this page: Was this page helpful? Also known as: CCP Antibody; Citrulline Antibody; Anti-citrulline Antibody; Anti-cyclic Citrullinated ...

  1. Citrullinated peptides in the diagnosis of rheumatoid arthritis.

    PubMed

    Gómara, María J; Haro, Isabel

    2013-01-01

    Antibodies directed against citrullinated proteins and peptides (ACPAs) are the most specific serological markers available for diagnosing rheumatoid arthritis (RA). ACPAs may be detected several years before symptoms of RA appear, and their presence at disease onset is a good predictor of the development of erosive joint lesions. RA patients can be classified into two major groups: those who have ACPAs and those who do not. The presence of ACPAs at early stages of RA predicts the development of earlier and more widespread joint erosions, and low remission rates.Synthetic peptides can replace cognate proteins in solid-phase assays for specific autoantibody recognition in RA patients. The use of synthetic peptides instead of proteins represents an advantage in terms of the reproducibility of such immunoassays. Proteins also contain non-citrullinated epitopes that are recognized by non-RA sera and this could reduce the specificity of the test. The use of synthetic citrullinated peptides gives absolute control over the exact epitopes presented. Furthermore, it is difficult to prepare sufficient amounts of high-quality antigenic proteins with a well-defined degree of citrullination. Synthetic citrullinated peptides, in contrast, are easily obtained in a pure form with a well-defined chemical structure and the epitopes can be precisely oriented in the plate by covalent binding of the peptides.Chimeric peptides bearing different citrullinated protein domains have recently been used in the design of RA diagnosis systems. The results of the application of those systems indicate that more than one serological test is required to classify RA patients based on the presence or absence of ACPAs. Each of the target molecules reported (fibrin, vimentin and filaggrin) helps to identify a particular subset of RA patients.

  2. The presence of anti-citrullinated protein antibodies (ACPA) and rheumatoid factor on patients with rheumatoid arthritis (RA) does not interfere with the chance of clinical remission in a follow-up of 3 years.

    PubMed

    da Mota, Licia Maria Henrique; Dos Santos Neto, Leopoldo Luiz; de Carvalho, Jozélio Freire; Pereira, Ivânio Alves; Burlingame, Rufus; Ménard, Henri A; Laurindo, Ieda Maria Magalhães

    2012-12-01

    Autoantibodies in early rheumatoid arthritis (RA) have important diagnostic value. The association between the presence of autoantibodies against cyclic citrullinated peptide and the response to treatment is controversial. To prospectively evaluate a cohort of patients with early rheumatoid arthritis (<12 months of symptoms) in order to determine the association between serological markers (rheumatoid factor (RF), anti-citrullinated protein antibodies) such as anti-cyclic citrullinated peptide antibodies (anti-CCP) and citrullinated anti-vimentin (anti-Sa) with the occurrence of clinical remission, forty patients diagnosed with early RA at the time of diagnosis were evaluated and followed for 3 years, in use of standardized therapeutic treatment. Demographic and clinical data were recorded, disease activity score 28 (DAS 28), as well as serology tests (ELISA) for RF (IgM, IgG, and IgA), anti-CCP (CCP2, CCP3, and CCP3.1) and anti-Sa in the initial evaluation and at 3, 6, 12, 18, 24, and 36 months of follow-up. The outcome evaluated was the percentage of patients with clinical remission, which was defined by DAS 28 lower than 2.6. Comparisons were made through the Student t test, mixed-effects regression analysis, and analysis of variance (significance level of 5%). The mean age was 45 years, and a female predominance was observed (90%). At the time of diagnosis, RF was observed in 50% of cases (RF IgA-42%, RF IgG-30%, and RF IgM-50%), anti-CCP in 50% (no difference between CCP2, CCP3, and CCP3.1) and anti-Sa in 10%. After 3 years, no change in the RF prevalence and anti-CCP was observed, but the anti-Sa increased to 17.5% (P = 0.001). The percentage of patients in remission, low, moderate, and intense disease activity, according to the DAS 28, was of 0, 0, 7.5, and 92.5% (initial evaluation) and 22.5, 7.5, 32.5, and 37.5% (after 3 years). There were no associations of the presence of autoantibodies in baseline evaluation and in serial analysis with the percentage of

  3. The stimulation of the mitochondrial respiration by citrulline synthesis.

    PubMed

    Letko, G; Markefski, M; Bohnensack, R

    1979-01-01

    1. The influence of ammonia and ornithine on the oxygen uptake and the formation of citrulline was investigated with isolated rat liver mitochondria. The experiments were performed in a cytosol-like saline medium at 38 degrees C. 2. Under these conditions an increase of the respiration rate by ammonia and ornithine was observed, but a small response to external ADP, only. The missing stimulation by ADP was due to a partial inhibition of the respiratory chain by traces of zinc (approximately 1 microM) present in the medium. This inhibition was only detected at low concentrations of mitochondria. 3. For activation of respiration by ammonia plus ornithine two different processes were responsible: (i) chelation of the inhibiting zinc by ornithine, which could be prevented by EDTA; (ii) ADP production in the matrix space during formation of carbamoyl phosphate, which could be prevented by oligomycin but not by carboxyatractyloside. 4. This stimulus of the carbamoyl phosphate formation and of the equivalent citrulline synthesis on the mitochondrial respiration ran to 12% of that increase caused by phosphorylation of external ADP. The maximum rate of citrulline formation was limited by the activity of carbamoyl phosphate synthetase. 5. Added ADP suppresses the production of citrulline probably by the exchange of extramitochondrial ADP versus intramitochondrial ATP. The data suggest a common adenine nucleotide pool delivering ATP to the adenine nucleotide translocase as well as to the carbamoyl phosphate synthetase.

  4. Arginine utilization of citrulline synthesis in arginase II knockout mice

    USDA-ARS?s Scientific Manuscript database

    The synthesis of citrulline (Cit) from arginine (Arg) in the small intestine depends on the activity of arginase II (ARG2). To test the hypothesis that Arg is the main dietary precursor for Cit synthesis, despite the lack of ARG2, tracer studies were conducted in WT and ARG2 ko conscious mice. WT mi...

  5. Glutamine: Precursor or nitrogen donor for citrulline synthesis?

    USDA-ARS?s Scientific Manuscript database

    Although glutamine is considered the main precursor for citrulline synthesis, the current literature does not differentiate between the contribution of glutamine carbon skeleton, versus nonspecific nitrogen (i.e., ammonia) and carbon derived from glutamine oxidation. To elucidate the role of glutami...

  6. Precursors for ornithine and citrulline synthesis in neonatal pigs

    USDA-ARS?s Scientific Manuscript database

    Citrulline (CIT) is an amino acid synthesized by gut and utilized for the synthesis of the conditionally essential amino acid arginine (ARG). In turn, the immediate precursor for CIT synthesis, ornithine (ORN), can originate from proline (PRO) and glutamine (GLN) via ornithine aminotransferase (OAT,...

  7. Glutamine: precursor or nitrogen donor for citrulline synthesis?

    USDA-ARS?s Scientific Manuscript database

    Glutamine (Gln) is considered the main precursor for citrulline (Cit) synthesis, but no attempts have been made to differentiate the contribution of Gln carbon (Gln-C) skeleton vs. the nonspecific contribution through NH3 and CO2. To study the contribution of dietary Gln-N to the synthesis of Cit, t...

  8. Identification of citrullinated peptides in the synovial fluid of patients with rheumatoid arthritis using LC-MALDI-TOF/TOF.

    PubMed

    Wang, Fei; Chen, Fang-Fang; Gao, Wen-Bo; Wang, Hai-Yong; Zhao, Ning-Wei; Xu, Min; Gao, De-Yu; Yu, Wei; Yan, Xiao-Ling; Zhao, Jian-Ning; Li, Xiao-Jun

    2016-09-01

    The objective of the study is to investigate potential citrullinated autoantigens as targets of anti-citrullinated protein antibodies (ACPAs) response in synovial fluids (SFs) of patients with rheumatoid arthritis (RA). SFs from six RA patients and six osteoarthritis (OA) patients as controls were collected. The citrullinated proteins in SFs were extracted by immunoprecipitation with rabbit anti-citrulline antibodies. Matrix-assisted laser desorption/ionization time of flight mass spectrometry/time of flight mass spectrometry (MALDI-TOF/TOF) mass spectrometry was subsequently performed to discover a characteristic neutral loss to finally determine citrullinated autoantigens. A total of 182 citrullinated peptides and 200 citrullinated sites were identified in RA SFs, while 3 citrullinated peptides and 4 citrullinated sites were identified in OA SFs. The 182 citrullinated peptides from RA SFs and the 3 citrullinated peptides from OA SFs were derived from 83 and 3 autoantigens, respectively. Eighty-three autoantigens except protein-arginine deiminase type-2 (PADI2) and protein-arginine deiminase type-2 (PADI4) were over-citrullinated compared with controls, and the citrullinated sites of PADI2 and PADI4 were different in two groups. Interestingly, citrullinated histone H3.3 (H3F3A) was found in OA controls, but not in RA groups. The differential citrullinated proteins identified in RA SFs suggested potential autoantigens were targeted for ACPAs response and might contribute to the induction and perpetuation of complement activation and joint inflammation in RA.

  9. Alterations in glutamine metabolism and its conversion to citrulline in sepsis

    PubMed Central

    Hsu, Jean; Bandi, Venkata; Jahoor, Farook

    2013-01-01

    In enterocytes, glutamine serves as the major source of energy; another metabolic fate of glutamine is conversion to citrulline. Because sepsis can affect gut function and integrity, alterations in glutamine metabolism may exist and lead to decreased citrulline production. This study aimed to investigate how sepsis affects glutamine metabolism, including its conversion to citrulline, by measuring glutamine and citrulline flux, fractional splanchnic extraction of glutamine and leucine, and the contribution of glutamine nitrogen to citrulline in septic patients and healthy controls. Eight patients with severe sepsis and 10 healthy controls were given primed, constant intravenous infusion of [2H2]citrulline and sequential administration of intravenous and enteral [α-15N]glutamine and [13C]leucine in the postabsorptive state. The results showed that, compared with healthy controls, septic patients had a significantly lower whole body citrulline flux and plasma concentration, higher endogenous leucine flux, and higher glutamine clearance. Fractional splanchnic extraction of leucine was higher in septic patients than in controls, but fractional extraction of glutamine was not different. The majority of the 15N label transferred from glutamine to citrulline was found at the α-position. These results demonstrate that lower glutamine plasma concentrations in sepsis were a result of increased glutamine clearance. Despite adequate splanchnic uptake of glutamine, there is decreased production of citrulline, suggesting a defect in the metabolic conversion of glutamine to citrulline, decreased uptake of glutamine by the enterocyte but increased uptake by the liver, and/or shunting of glutamine to other metabolic pathways. PMID:23612995

  10. Plasma Glutamine Is a Minor Precursor for the Synthesis of Citrulline: A Multispecies Study.

    PubMed

    Marini, Juan C; Agarwal, Umang; Didelija, Inka C; Azamian, Mahshid; Stoll, Barbara; Nagamani, Sandesh Cs

    2017-04-01

    Background: Glutamine is considered the main precursor for citrulline synthesis in many species, including humans. The transfer of (15)N from 2-[(15)N]-glutamine to citrulline has been used as evidence for this precursor-product relation. However, work in mice has shown that nitrogen and carbon tracers follow different moieties of glutamine and that glutamine contribution to the synthesis of citrulline is minor. It is unclear whether this small contribution of glutamine is also true in other species.Objective: The objective of the present work was to determine the contribution of glutamine to citrulline production by using nitrogen and carbon skeleton tracers in multiple species.Methods: Humans (n = 4), pigs (n = 5), rats (n = 6), and mice (n = 5) were infused with l-2-[(15)N]- and l-[(2)H5]-glutamine and l-5,5-[(2)H2]-citrulline. The contribution of glutamine to citrulline synthesis was calculated by using different ions and fragments: glutamine M+1 to citrulline M+1, 2-[(15)N]-glutamine to 2-[(15)N]-citrulline, and [(2)H5]-glutamine to [(2)H5]-citrulline.Results: Species-specific differences in glutamine and citrulline fluxes were found (P < 0.001), with rats having the largest fluxes, followed by mice, pigs, and humans (all P < 0.05). The contribution of glutamine to citrulline as estimated by using glutamine M+1 to citrulline M+1 ranged from 88% in humans to 46% in pigs. However, the use of 2-[(15)N]-glutamine and 2-[(15)N]-citrulline as precursor and product yielded values of 48% in humans and 28% in pigs. Furthermore, the use of [(2)H5]-glutamine to [(2)H5]-citrulline yielded lower values (P < 0.001), resulting in a contribution of glutamine to the synthesis of citrulline of ∼10% in humans and 3% in pigs.Conclusions: The recycling of the [(15)N]-glutamine label overestimates the contribution of glutamine to citrulline synthesis compared with a tracer that follows the carbon skeleton of glutamine. Glutamine is a minor precursor for the synthesis of

  11. Determination of citrulline and homocitrulline by high-performance liquid chromatography with post-column derivatization.

    PubMed

    Koshiishi, I; Kobori, Y; Imanari, T

    1990-10-26

    A high-performance liquid chromatographic method was developed for the determination of citrulline and homocitrulline using a post-column colorimetric reaction with o-phthaladehyde and N-(1-naphthyl)-ethylenediamine. Citrulline and homocitrulline were determined with no interferences from protein amino acids. The results show that the level of citrulline in the plasma of patients with uremia on intermittent hemodialysis is higher than that in healthy human plasma, and that homocitrulline is excreted into the urine of healthy adults.

  12. Peptidylarginine deiminases in citrullination, gene regulation, health and pathogenesis

    PubMed Central

    Wang, Shu; Wang, Yanming

    2013-01-01

    Peptidylarginine deiminases are a family of enzymes that mediate post-translational modifications of protein arginine residues by deimination or demethylimination to produce citrulline. In vitro, the activity of PADs is dependent on calcium and reductive reagents carrying a free sulfhydryl group. The discovery that PAD4 can target both arginine and methyl-arginine for citrullination about 10 years ago renewed our interest in studying this family of enzymes in gene regulation and their physiological functions. The deregulation of PADs is involved in the etiology of multiple human diseases, including cancers and autoimmune disorders. There is a growing effort to develop isoform specific PAD inhibitors for disease treatment. However, the regulation of the activity of PADs in vivo remains largely elusive, and we expect that much will be learned about the role of these enzymes in normal life cycle and under pathology conditions. PMID:23860259

  13. Autoimmunity to Citrullinated Proteins and the Initiation of Rheumatoid Arthritis

    PubMed Central

    Holers, V. Michael

    2014-01-01

    Clinical manifestations of rheumatoid arthritis (RA), the second most common human autoimmune disease, are primarily focused on the joints, causing disability and requiring life-long treatment to ameliorate signs and symptoms. The etiology of RA is unknown; however, important discoveries in two areas have been made which provide hope that the causal mechanisms can be identified. First, the most severe form of this disease is associated with the presence of humoral and cellular autoimmunity to citrullinated proteins and peptides. Second, in the natural history of RA, autoimmunity to citrullinated antigens appears years prior to the onset of clinically apparent disease. Herein is described a model in which to consider how these two features are linked during very early disease development. PMID:24215742

  14. [The clinical informativeness of detection of antibodies to citrullinated proteins under rheumatoid arthritis].

    PubMed

    Cherkasova, M V; Novikov, A A; Alexndrova, E N; Karateev, D E; Popkova, T V; Luchikhina, E L; Avdeeva, A S; Nasonov, E L

    2015-02-01

    The main diagnostic laboratory markers of rheumatoid arthritis are IgM rheumatoid factor and antibodies to citrullinated proteins. The IgM rheumatoid factor is a sensitive but insufficiently specific marker of rheumatoid arthritis. The antibodies to citrullinated proteins have a higher specificity for diagnostic of rheumatoid arthritis. The antibodies to cyclic citrullinated peptide and modified citrullinated vimentin are the main representatives of family of antibodies to citrullinated proteins applying in clinical diagnostic practice. The study was carried out to deternine the role of antibodies to citrullinated proteins and modified citrullinated vimentin in diagnostic, evaluation of activity and severity of destructive alterations under rheumatoid arthritis. The samplings of 993 patients with reliable diagnosis of rheumatoid arthritis. 179 patients with other rheumatoid diseases and 30 healthy donors were examined. The measurement of serum concentration of IgM rheumatoid factor and C-reactive protein was implemented by immune nephelometric analysis and antibodies to citrullinated proteins were analyzed by enzymoimmunoassay The erythrocyte sedimentation rate was established using the Westergreen technique. It was established that antibodies to modified citrullinated vimentin had the highest diagnostic specificity (83%), antibodies to cyclic citrullinated peptide had the highest diagnostic specificity (87%). The diagnostic specificity of joint detection of IgM rheumatoid factor, antibodies to citrullinated proteins and antibodies to modified citrullinated vimentin made up to 87%. In patients negative to rheumatoid factor the rate ofdetection of antibodies to citrullinated proteins made up to 34% and antibodies to modified citrullinated vimentin made up to 48%. The diagnostic effectiveness of detection of antibodies to citrullinitted proteins (ratio of likelihood of positive and negative results of test was correspondingly 5.5 and 0.3; area under ROC curve 0

  15. The antibodies cyclic citrullinated peptides (anti-CCP) positivity could be a promising marker in brucellosis patients presented with peripheric arthritis.

    PubMed

    Gokhan, Azize; Turkeyler, Ibrahim Halil; Babacan, Taner; Pehlivan, Yavuz; Dag, Muhammet Said; Bosnak, Vuslat Kecik; Namiduru, Mustafa; Kisacik, Bunyamin; Onat, Ahmet Mesut

    2014-01-01

    The anti-cyclic citrullinated peptide (anti-CCP) enzyme-linked immunosorbent assay has a high sensitivity and specificity for rheumatoid arthritis (RA). It has been used in especially early diagnosis of RA, and used to discriminate from other forms of arthritis. Anti-CCP positivity is unknown in brucellosis presented with peripheric arthritis (BPA), like other rheumatic diseases. The objective of this study was to investigate the positivity of anti-CCP in patients with BPA in contrast to the patients with RA and healthy controls. Additionally, we have aimed to monitor changes of anti-CCP levels following the brucellosis treatment. The study group consisted of 137 subjects. 62 brucellosis patients presented with peripheric arthritis. Additionally, 33 RA patients and 42 healthy subjects selected as control groups. The anti-CCP, rheumatoid factor and anti-nuclear antibody levels of the subjects were measured. Concerning the 62 BPA, 20 % (13 patients) of them had elevated anti-CCP levels. On the other side, of the 33 RA patients, 78.78 % (26 patients) of them had increased anti-CCP levels. Only one healthy subject's anti-CCP level was positive. There was statistically significant difference among the groups. After brucellosis treatment, monitorisation of the 13 patients with BPA who have the positive anti-CCP levels, were challengingly interesting because none of the patients had positive anti-CCP levels. Anti-CCP may be positive marker in the diagnosis of BPA but clinicians need to be careful during the follow up period because it may turn into normal ranges. Additionally, patients presented with peripheric arthritis and anti-CCP positivity need to be evaluated also for the differential diagnosis of BPA.

  16. Serial determination of cyclic citrullinated peptide autoantibodies predicted five-year radiological outcomes in a prospective cohort of patients with early rheumatoid arthritis

    PubMed Central

    Meyer, Olivier; Nicaise-Roland, Pascale; Santos, Marie dos; Labarre, Colette; Dougados, Maxime; Goupille, Philippe; Cantagrel, Alain; Sibilia, Jean; Combe, Bernard

    2006-01-01

    The objective of this study was to evaluate the potential of serially determined anti-cyclic citrullinated peptide (CCP) antibodies for predicting structural joint damage in patients with early rheumatoid arthritis (RA), compared to a single baseline determination. Ninety-nine RA patients with disease durations of less than one year and no history of disease-modifying antirheumatic drug therapy were followed prospectively for at least five years. Anti-CCP2 concentrations were measured using a second-generation ELISA. Sharp scores as modified by van der Heijde were determined on hand and foot radiographs. Anti-CCP2 antibodies were detected in 55.5% of patients at baseline and 63.6% at any time during the first three years. Presence of anti-CCP2 at any time during the first three years was associated with radiographic damage at baseline (odds ratio (OR), 3.66; 95% confidence interval (95% CI) 0.99–13.54) and with five year progression of the total Sharp score (OR, 3.17; 95% CI, 1.3–7.7), erosion score (OR, 5.3; 95% CI, 1.4–19.2) and joint space narrowing score (OR, 2.8; 95% CI, 1.15–6.8). The presence of anti-CCP2 or IgM RF at baseline did not predict these outcomes. Patients with negative anti-CCP2 tests throughout follow-up had less radiographic progression than patients with increasing anti-CCP2 concentrations; they did not differ from patients with decreasing anti-CCP2 antibody levels. HLADRB1* typing showed that progression of the mean modified Sharp score was not correlated with the presence of the shared epitope alleles. In conclusion, serially determined anti-CCP2 antibodies during the first three years of follow-up performs better than baseline determination for predicting radiographic progression in patients with early RA. PMID:16469118

  17. Physical Characteristics of a Citrullinated Pro-Filaggrin Epitope Recognized by Anti-Citrullinated Protein Antibodies in Rheumatoid Arthritis Sera

    PubMed Central

    Trier, Nicole Hartwig; Holm, Bettina Eide; Slot, Ole; Locht, Henning; Lindegaard, Hanne; Svendsen, Anders; Houen, Gunnar

    2016-01-01

    Rheumatoid arthritis (RA) is an autoimmune disease of complex etiology. A characteristic feature of a subset of RA is the presence of anti-citrullinated protein antibodies (ACPA), which correlate with a progressive disease course. In this study, we employed streptavidin capture enzyme-linked immunosorbent assay to analyze ACPA reactivity. Using the pro-filaggrin peptide HQCHQEST-Cit-GRSRGRCGRSGS, as template, we analyzed the reactivity of RA sera and healthy donor sera to various peptides in order to determine the physical characteristics of the citrullinated pro-filaggrin epitope and to examine whether biotin labelling influence antibody recognition. The full-length cyclic pro-filaggrin peptide and a linear form with a N-terminal biotin, was recognized to the same level, whereas, a notable difference in ACPA reactivity to the linear peptides with a C-terminal biotin was found, probably due to steric hindrance. Screening of linear and cyclic truncated peptides, revealed that small cyclic peptides containing 10–12 amino acids are favored over the linear. Moreover, the charged amino acids C-terminal to citrulline were found to be essential for antibody reactivity, most important was the charged amino acid in position 4 C-terminal to citrulline. Collectively, peptide structure, length, the presence of charged amino acids and biotin labelling markedly influence antibody reactivity. In relation to the clinical diagnostics of ACPA, these findings may reflect the differences in diagnostic assays used for detection of ACPA, which relates to differences in sensitivity and specificity dependent on the assay applied. PMID:28002483

  18. Anti-citrullinated peptide antibodies in Sudanese patients with Leishmania donovani infection exhibit reactivity not dependent on citrullination.

    PubMed

    Åhlin, E; Elshafie, A I; Nur, M A M; Rönnelid, J

    2015-03-01

    African patients with Leishmania donovani infections have signs of strong systemic inflammation and high levels of circulating immune complexes (IC) and rheumatoid factor (RF), all serologic markers of rheumatic disease. As inflammation in general is associated with citrullination, we sought to investigate ACPA responses in Sudanese Leishmania patients. Serum samples were collected from Sudanese patients with visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL) as well as from ACPA-positive Sudanese rheumatoid arthritis patients and compared to healthy Sudanese controls. Levels of circulating C1q-binding IC and anticyclic citrullinated peptide 2(CCP2) were investigated using ELISA, and RF was measured with nephelometry. C1q adsorption was carried out to investigate anti-CCP2 content in IC. Citrulline specificity was evaluated with control plates with cyclic arginine-containing control peptides. Leishmania-infected patients had elevated levels of RF and circulating IC but also a significant increase in anti-CCP2 (12%) as compared to healthy controls. Anti-CCP2-positive Leishmania patients displayed lower anti-CCP2 levels than Sudanese patients with rheumatoid arthritis (RA), and anti-CCP2 levels in Leishmania patients showed a continuum not resembling the dichotomous pattern seen in patients with RA. Whereas the anti-CCP reactivity of Sudanese RA sera was strictly citrulline dependent, anti-CCP2-positive Leishmania sera reacted equally well with ELISA plates containing arginine control peptides. There was a strong correlation between anti-CCP2 and circulating IC among the Leishmania patients, but IC depletion only marginally diminished anti-CCP2 levels. Our findings stress the importance to interpret a positive CCP test carefully when evaluated in non-rheumatic conditions associated with macrophage activation. © 2015 The Authors. Scandinavian Journal of Immunology published by John Wiley & Sons Ltd on behalf of Scandanavian Society of

  19. Citrullination of glial intermediate filaments is an early response in retinal injury

    PubMed Central

    Wizeman, John W.; Nicholas, Anthony P.; Ishigami, Akihito

    2016-01-01

    Purpose A hallmark of retinal gliosis is the increased detection and modification of the type III intermediate filament (IF) proteins vimentin and glial fibrillary acidic protein (GFAP). Here, we investigated vimentin and GFAP in Müller glia in a mouse model of alkali injury, focusing on the posttranslational modification of citrullination. Methods Mice were injured by corneal exposure to 1.0 N NaOH, and eyes were enucleated at different time points following injury. The levels of soluble and cytoskeletal forms of IF proteins and citrullination were measured using western blot analysis. Citrullinated GFAP was identified by immunoprecipitation followed by two-dimensional (2D) isoelectric focusing–polyacrylamide gel electrophoresis (IEF-PAGE) western blotting using a specific antibody that recognizes citrullinated GFAP. Vimentin, GFAP, and citrullinated proteins were localized in the retina by immunohistochemistry (IHC). Drug treatments were investigated in retinal explant cultures of posterior eyecups obtained from mouse eyes that were injured in vivo. Results Detection of GFAP in injured retinas increased over a period of 1 to 7 days, showing increased levels in both soluble and cytoskeletal forms of this IF protein. The global level of citrullinated proteins was also induced over this period, with low-salt buffer extraction showing the most abundant early changes in citrullination. Using IHC, we found that GFAP filaments assembled at Müller glial end feet, growing in size with time through the inner layers of the retina at 1–3 h postinjury. Interestingly, over this early time period, levels of soluble citrullinated proteins also increased within the retina, as detected by western blotting, coincident with the localization of the citrullinated epitopes on growing GFAP filaments and existing vimentin filaments by 3 h after injury. Taking advantage of the in vivo injury model to promote a robust gliotic response, posterior eyecups from 7-day postinjured eyes

  20. L-citrulline immunostaining identifies nitric oxide production sites within neurons.

    PubMed

    Martinelli, G P T; Friedrich, V L; Holstein, G R

    2002-01-01

    The cellular and subcellular localization of L-citrulline was analyzed in the adult rat brain and compared with that of traditional markers for the presence of nitric oxide synthase. Light, transmission electron, and confocal laser scanning microscopy were used to study tissue sections processed for immunocytochemistry employing a monoclonal antibody against L-citrulline or polyclonal anti-neuronal nitric oxide synthase sera, and double immunofluorescence to detect neuronal nitric oxide synthase and L-citrulline co-localization. The results demonstrate that the same CNS regions and cell types are labeled by neuronal nitric oxide synthase polyclonal antisera and L-citrulline monoclonal antibodies, using both immunocytochemistry and immunofluorescence. Short-term pretreatment with a nitric oxide synthase inhibitor reduces L-citrulline immunostaining, but does not affect neuronal nitric oxide synthase immunoreactivity. In the vestibular brainstem, double immunofluorescence studies show that many, but not all, neuronal nitric oxide synthase-positive cells co-express L-citrulline, and that local intracellular patches of intense L-citrulline accumulation are present in some neurons. Conversely, all L-citrulline-labeled neurons co-express neuronal nitric oxide synthase. Cells expressing neuronal nitric oxide synthase alone are interpreted as neurons with the potential to produce nitric oxide under other stimulus conditions, and the subcellular foci of enhanced L-citrulline staining are viewed as intracellular sites of nitric oxide production. This interpretation is supported by ultrastructural observations of subcellular foci with enhanced L-citrulline and/or neuronal nitric oxide synthase staining that are located primarily at postsynaptic densities and portions of the endoplasmic reticulum. We conclude that nitric oxide is produced and released at focal sites within neurons that are identifiable using L-citrulline as a marker. Copyright 2002 IBRO

  1. L-citrulline immunostaining identifies nitric oxide production sites within neurons

    NASA Technical Reports Server (NTRS)

    Martinelli, G. P. T.; Friedrich, V. L. Jr; Holstein, G. R.

    2002-01-01

    The cellular and subcellular localization of L-citrulline was analyzed in the adult rat brain and compared with that of traditional markers for the presence of nitric oxide synthase. Light, transmission electron, and confocal laser scanning microscopy were used to study tissue sections processed for immunocytochemistry employing a monoclonal antibody against L-citrulline or polyclonal anti-neuronal nitric oxide synthase sera, and double immunofluorescence to detect neuronal nitric oxide synthase and L-citrulline co-localization. The results demonstrate that the same CNS regions and cell types are labeled by neuronal nitric oxide synthase polyclonal antisera and L-citrulline monoclonal antibodies, using both immunocytochemistry and immunofluorescence. Short-term pretreatment with a nitric oxide synthase inhibitor reduces L-citrulline immunostaining, but does not affect neuronal nitric oxide synthase immunoreactivity. In the vestibular brainstem, double immunofluorescence studies show that many, but not all, neuronal nitric oxide synthase-positive cells co-express L-citrulline, and that local intracellular patches of intense L-citrulline accumulation are present in some neurons. Conversely, all L-citrulline-labeled neurons co-express neuronal nitric oxide synthase. Cells expressing neuronal nitric oxide synthase alone are interpreted as neurons with the potential to produce nitric oxide under other stimulus conditions, and the subcellular foci of enhanced L-citrulline staining are viewed as intracellular sites of nitric oxide production. This interpretation is supported by ultrastructural observations of subcellular foci with enhanced L-citrulline and/or neuronal nitric oxide synthase staining that are located primarily at postsynaptic densities and portions of the endoplasmic reticulum. We conclude that nitric oxide is produced and released at focal sites within neurons that are identifiable using L-citrulline as a marker. Copyright 2002 IBRO.

  2. Plasma glutamine is a minor precursor for the synthesis of citrulline: A multispecies study

    USDA-ARS?s Scientific Manuscript database

    Glutamine is considered the main precursor for citrulline synthesis in many species, including humans. The transfer of 15N from 2[15N]-glutamine to citrulline has been used as evidence for this precursor-product relationship. However, work in mice has shown that nitrogen and carbon tracers follow di...

  3. Spatial accumulation pattern of citrulline and other nutrients in immature and mature watermelon fruits.

    PubMed

    Akashi, Kinya; Mifune, Yuki; Morita, Kaori; Ishitsuka, Souichi; Tsujimoto, Hisashi; Ishihara, Toshiyuki

    2017-01-01

    Watermelon (Citrullus lanatus L.) originates from arid regions of southern Africa, and its fruit contains a large amount of the amino acid citrulline, an efficient hydroxyl radical scavenger. Citrulline is implicated in the production of nitric oxide in human endothelium, and potential health benefits including vasodilatation and antioxidant functions have been suggested. However, citrulline metabolism in watermelon fruits is poorly understood. This study examined the accumulation pattern of citrulline and other nutrients in immature and mature watermelon fruits. In mature fruits, highest citrulline concentration was observed in the outer peel, followed by the central portion of the flesh and inner rinds, whereas the level was lower in the peripheral portion of the flesh. Citrulline content was generally low in immature fruits. Spatial and developmental patterns of citrulline accumulation were largely different from those of the antioxidant lycopene, total proteins, and soluble sugars such as glucose, fructose, and sucrose. Principal component analysis suggested a clear distinction of the central flesh and outer peels in mature fruits from other tissues in terms of the levels of major nutrients. These observations suggested that citrulline accumulation may be regulated in a distinct manner from other nutrients during watermelon fruit maturation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. Methods for analyzing histone citrullination in chromatin structure and gene regulation.

    PubMed

    Li, Pingxin; Hu, Jing; Wang, Yanming

    2012-01-01

    Histone posttranslational modifications play significant roles in regulating chromatin structure and gene expression. One of the histone modifications, histone citrullination, is catalyzed by an enzyme called peptidylarginine deiminase 4 (PAD4, also called PADI4), which converts both histone arginine (Arg) and mono-methyl arginine residues to citrulline. Recent studies have found that histone citrullination counteracts the effect of histone arginine methylation and functions as a repressive marker to turn off gene expression. Here, we describe assays to study histone citrullination by PAD4 in vitro and in vivo. We also describe approaches to measure histone citrullination levels at gene promoters using chromatin immunoprecipitation assay and analyze the effects of PAD4 inhibitor on cell cycle and apoptosis by flow cytometry. These methods would be useful techniques to study this unique histone modification.

  5. Identification of citrullinated cellular fibronectin in synovial fluid from patients with rheumatoid arthritis.

    PubMed

    Kimura, Eri; Kanzaki, Takeyuki; Tahara, Koichiro; Hayashi, Haeru; Hashimoto, Shiori; Suzuki, Akari; Yamada, Ryo; Yamamoto, Kazuhiko; Sawada, Tetsuji

    2014-09-01

    Cellular fibronectin (cFn) has been implicated in the pathogenesis of rheumatoid arthritis (RA), and we previously demonstrated the presence of citrullinated cFn in rheumatoid synovial tissues. The present study aimed to investigate whether citrullinated cFn can be detected in the plasma or synovial fluid of RA patients. Twenty-five rheumatoid arthritis synovial fluid (RASF), seven osteoarthritis synovial fluid (OASF) and 12 plasma samples from RA patients were examined. Citrullination of cFn was determined by immunoprecipitation (IP), western blotting and enzyme-linked immunosorbent assay (ELISA), in which peptidyl-citrulline within cFn was detected using a specific anti-cFn monoclonal antibody in combination with anti-modified citrulline antibody after chemical modification. Levels of citrullination associated with cFn, as determined by ELISA, were significantly higher in RASF than in OASF samples. IP and western blotting detected citrullinated cFn in RASF but not in plasma samples from RA patients. Levels of total cFn were elevated in RASF compared with OASF, and 24 out of 25 RASF samples were positive for anti-CCP antibody. However, no correlation was observed between levels of citrullinated cFn and those of total cFn or anti-CCP antibody in RASF. On the other hand, a significant positive correlation was observed between the levels of matrix metalloproteinase-3 (MMP-3) and cFn citrullination in RASF. Citrullinated cFn appears to be produced within the affected joint and might be involved in the pathogenesis of rheumatoid synovitis.

  6. Local Joint inflammation and histone citrullination in a murine model of the transition from preclinical autoimmunity to inflammatory arthritis.

    PubMed

    Sohn, Dong Hyun; Rhodes, Christopher; Onuma, Kazuhiro; Zhao, Xiaoyan; Sharpe, Orr; Gazitt, Tal; Shiao, Rani; Fert-Bober, Justyna; Cheng, Danye; Lahey, Lauren J; Wong, Heidi H; Van Eyk, Jennifer; Robinson, William H; Sokolove, Jeremy

    2015-11-01

    Anti-citrullinated protein antibodies (ACPAs) are characteristic of rheumatoid arthritis (RA). However, their presence years before the onset of clinical RA is perplexing. Although multiple putative citrullinated antigens have been identified, no studies have demonstrated the specific capacity of these antigens to initiate inflammatory arthritis. This study was undertaken to recapitulate the transition from preclinical to clinical RA and to demonstrate the capacity of local citrullination to facilitate this transition. We performed proteomic analysis of activated human neutrophils to identify citrullinated proteins, including those targeted as part of the RA immune response. Using enzyme-linked immunosorbent assay, we compared RA and osteoarthritis synovial fluid for levels of citrullinated histone H2B and its immune complex. Using macrophage activation assays, we assessed the effect of histone citrullination on immunostimulatory capacity and evaluated the stimulatory capacity of native and citrullinated H2B immune complexes. Finally, we assessed the potential for anti-citrullinated H2B antibodies to mediate arthritis in vivo. We identified robust targeting of neutrophil-derived citrullinated histones by the ACPA immune response. More than 90% of the RA patients had anti-citrullinated H2B antibodies. Histone citrullination increased innate immunostimulatory capacity, and immune complexes containing citrullinated histones activated macrophage cytokine production and propagated neutrophil activation. Finally, we demonstrated that immunization with H2B was arthritogenic, but only in the setting of underlying articular inflammation. Our findings indicate that citrullinated histones, specifically citrullinated H2B, are an antigenic target of the ACPA immune response. Furthermore, local generation of citrullinated antigen during low-grade articular inflammation provides a mechanistic model for the conversion from preclinical autoimmunity to inflammatory arthritis

  7. Anti-citrullinated fibronectin antibodies in rheumatoid arthritis are associated with human leukocyte antigen-DRB1 shared epitope alleles

    PubMed Central

    2012-01-01

    Introduction Fibronectin is one of the most abundant proteins present in the inflamed joint. Here, we characterized the citrullination of fibronectin in the joints of rheumatoid arthritis (RA) patients and studied the prevalence, epitope specificity and human leukocyte antigen (HLA) association of autoantibodies against citrullinated fibronectin in RA. Methods Citrullinated residues in fibronectin isolated from RA patient synovial fluid were identified by mass spectrometry. The corresponding citrullinated and non-citrullinated peptides were synthesized and used to analyze the presence of autoantibodies to these peptides in RA sera and sera from other diseases and healthy controls by ELISA. The data were compared with risk factors like shared epitope HLA alleles and smoking, and with clinical features. Results Five citrullinated residues were identified in fibronectin from RA synovial fluid. RA sera reacted in a citrulline-dependent manner with two out of four citrullinated fibronectin peptides, one of which contains two adjacent citrulline residues, in contrast to non-RA sera, which were not reactive. The most frequently recognized peptide (FN-Cit1035,1036, LTVGLTXXGQPRQY, in which × represents citrulline) was primarily targeted by anti-CCP (cyclic citrullinated peptide) 2-positive RA patients. Anti-FN-Cit1035,1036 autoantibodies were detected in 50% of established anti-CCP2-positive RA patients and in 45% of such patients from a early arthritis clinic. These antibodies appeared to be predominantly of the immunoglobulin G (IgG) isotype and to be associated with HLA shared epitope alleles (odds ratio = 2.11). Conclusions Fibronectin in the inflamed synovia of RA patients can be citrullinated at least at five positions. Together with the flanking amino acids, three of these citrullinated residues comprise two epitopes recognized by RA autoantibodies. Anti-citrullinated fibronectin peptide antibodies are associated with HLA shared epitope alleles. PMID:22339947

  8. Citrulline and albumin as biomarkers for gastrointestinal mucositis in recipients of hematopoietic SCT.

    PubMed

    van der Velden, W J F M; Herbers, A H E; Brüggemann, R J M; Feuth, T; Peter Donnelly, J; Blijlevens, N M A

    2013-07-01

    Gastrointestinal (GI) mucositis is a common side effect of intense chemotherapy to prepare patients for hematopoietic SCT. Measuring intestinal damage objectively remains difficult, and clinicians often rely on albumin levels as an indicator of GI mucositis, but citrulline might be a more specific marker, which has in the past been shown to correlate with clinical signs of GI mucositis. We evaluated the courses of albumin and citrulline following different conditioning regimens for SCT and studied their relatedness to the subsequent inflammatory response using C-reactive protein. Patterns of albumin and citrulline differed significantly between myeloablative and non-myeloablative conditioning regimens. After myeloablative regimens, decreasing citrulline levels preceded the occurrence of inflammation unlike albumin levels, which decreased thereafter. Albumin levels were greatly influenced by inflammation, confirming it to be a 'negative acute-phase protein', whereas citrulline levels were not. Citrulline appeared to be a better biomarker of GI mucositis than albumin. Measuring citrulline might prove useful in clinical decision making, in identifying GI mucositis, and it would also be of interest to see how it compares with other biomarkers in the setting of acute GI GVHD.

  9. Identification and quantitation of asparagine and citrulline using high-performance liquid chromatography (HPLC).

    PubMed

    Bai, Cheng; Reilly, Charles C; Wood, Bruce W

    2007-03-28

    High-performance liquid chromatography (HPLC) analysis was used for identification of two problematic ureides, asparagine and citrulline. We report here a technique that takes advantage of the predictable delay in retention time of the co-asparagine/citrulline peak to enable both qualitative and quantitative analysis of asparagine and citrulline using the Platinum EPS reverse-phase C18 column (Alltech Associates). Asparagine alone is eluted earlier than citrulline alone, but when both of them are present in biological samples they may co-elute. HPLC retention times for asparagine and citrulline were influenced by other ureides in the mixture. We found that at various asparagines and citrulline ratios [= 3:1, 1:1, and 1:3; corresponding to 75:25, 50:50, and 25:75 (microMol ml(-1)/microMol ml(-1))], the resulting peak exhibited different retention times. Adjustment of ureide ratios as internal standards enables peak identification and quantification. Both chemicals were quantified in xylem sap samples of pecan [Carya illinoinensis (Wangenh.) K. Koch] trees. Analysis revealed that tree nickel nutrition status affects relative concentrations of Urea Cycle intermediates, asparagine and citrulline, present in sap. Consequently, we concluded that the HPLC methods are presented to enable qualitative and quantitative analysis of these metabolically important ureides.

  10. Identification and Quantitation of Asparagine and Citrulline Using High-Performance Liquid Chromatography (HPLC)

    PubMed Central

    Bai, Cheng; Reilly, Charles C.; Wood, Bruce W.

    2007-01-01

    High-performance liquid chromatography (HPLC) analysis was used for identification of two problematic ureides, asparagine and citrulline. We report here a technique that takes advantage of the predictable delay in retention time of the co-asparagine/citrulline peak to enable both qualitative and quantitative analysis of asparagine and citrulline using the Platinum EPS reverse-phase C18 column (Alltech Associates). Asparagine alone is eluted earlier than citrulline alone, but when both of them are present in biological samples they may co-elute. HPLC retention times for asparagine and citrulline were influenced by other ureides in the mixture. We found that at various asparagines and citrulline ratios [= 3:1, 1:1, and 1:3; corresponding to 75:25, 50:50, and 25:75 (μMol ml−1/μMol ml−1)], the resulting peak exhibited different retention times. Adjustment of ureide ratios as internal standards enables peak identification and quantification. Both chemicals were quantified in xylem sap samples of pecan [Carya illinoinensis (Wangenh.) K. Koch] trees. Analysis revealed that tree nickel nutrition status affects relative concentrations of Urea Cycle intermediates, asparagine and citrulline, present in sap. Consequently, we concluded that the HPLC methods are presented to enable qualitative and quantitative analysis of these metabolically important ureides. PMID:19662174

  11. Citrulline synthesis--a tool for investigation of the mitochondrial energy metabolism.

    PubMed

    Letko, G; Ulrich, H; Küster, U

    1984-01-01

    The conditions under which citrulline synthesis can be used to stimulate mitochondrial energy metabolism were investigated in isolated rat liver mitochondria. At 25 degrees C, with glutamate as substrate, a lag phase of citrulline formation was observed, which was neither detectable in the presence of succinate nor at 38 degrees C with both substrates. After a high-protein diet, a stationary synthesis was seen from the beginning of incubation for both substrates at either temperature. The high-protein diet was applied to reach maximal citrulline synthesis. Citrulline production was found to be enhanced twice to three times as early as after one to two days. Citrulline formation and associated oxygen uptake vs. temperature were checked in the range from 10 degrees C to 42 degrees C. A linear relationship was noted between temperature and reaction rates in the Arrhenius plot, and the share of citrulline synthesis in the total energy transformation increased with rising temperature. Citrulline synthesis was adopted in experiments to determine the equilibrium state of the adenine nucleotide translocator at 38 degrees C. Just as at 25 degrees C, the translocator operated under disequilibrium conditions at body temperature, too, and the loss of free energy was--3.2 kJ X mol-1.

  12. Urinary citrulline in very low birth weight preterm infants receiving intravenous nutrition.

    PubMed

    Bourdon, Aurélie; Rougé, Carole; Legrand, Arnaud; Des Robert, Clotilde; Piloquet, Hugues; Vodovar, Michel; Voyer, Marcel; Rozé, Jean-Christophe; Darmaun, Dominique

    2012-10-01

    As gut immaturity precludes full enteral feeding, very low birth weight (VLBW) preterm infants receive parenteral nutrition (PN) during the first few weeks of life. Weaning VLBW infants off PN, however, is a top priority since PN is associated with a high risk of complications. The decision making is purely empirical, as there is currently no suitable index of gastrointestinal (GI) maturity. Plasma citrulline concentration is considered an index of GI function in conditions such as short-bowel syndrome and coeliac disease in adults. To identify the factors determining urinary citrulline excretion, and determine whether urinary citrulline excretion could be used as a non-invasive index of GI tolerance to enteral feeding, nutritional intake and urinary citrulline were monitored bi-weekly in forty-seven preterm infants < 1500 g (interquartiles 880-1320 g), during their stay in the Neonatology unit. Median urinary citrulline was 24·7 μmol/mmol creatinine (14·5-38·6 μmol/mmol creatinine). No relationship was observed with the percentage of energy tolerated enterally. In multivariate regression analysis, weak correlations were found with post-conceptional age (P = 0·001), parenteral amino acid supply (P = 0·001) and the daily volume of enteral mixture administered (P = 0·043). A significant correlation was found with urinary nitrite+nitrate excretion (r 0·47; P < 0·001). We conclude that in preterm infants: (1) one of the major determinants of urinary citrulline may be the biosynthesis of citrulline from arginine by NO-synthase; (2) urinary citrulline cannot be used to predict GI tolerance. This is consistent with the observations that, in neonatal gut, citrulline is converted to arginine in situ rather than exported towards the kidneys as observed in adults.

  13. Low plasma citrulline levels are associated with acute respiratory distress syndrome in patients with severe sepsis.

    PubMed

    Ware, Lorraine B; Magarik, Jordan A; Wickersham, Nancy; Cunningham, Gary; Rice, Todd W; Christman, Brian W; Wheeler, Arthur P; Bernard, Gordon R; Summar, Marshall L

    2013-01-17

    The role of nitric oxide synthase (NOS) in the pathophysiology of acute respiratory distress syndrome (ARDS) is not well understood. Inducible NOS is upregulated during physiologic stress; however, if NOS substrate is insufficient then NOS can uncouple and switch from NO generation to production of damaging peroxynitrites. We hypothesized that NOS substrate levels are low in patients with severe sepsis and that low levels of the NOS substrate citrulline would be associated with end organ damage including ARDS in severe sepsis. Plasma citrulline, arginine and ornithine levels and nitrate/nitrite were measured at baseline in 135 patients with severe sepsis. ARDS was diagnosed by consensus definitions. Plasma citrulline levels were below normal in all patients (median 9.2 uM, IQR 5.2 - 14.4) and were significantly lower in ARDS compared to the no ARDS group (6.0 (3.3 - 10.4) vs. 10.1 (6.2 - 16.6), P = 0.002). The rate of ARDS was 50% in the lowest citrulline quartile compared to 15% in the highest citrulline quartile (P = 0.002). In multivariable analyses, citrulline levels were associated with ARDS even after adjustment for covariates including severity of illness. In severe sepsis, levels of the NOS substrate citrulline are low and are associated with ARDS. Low NOS substrate levels have been shown in other disease states to lead to NOS uncoupling and oxidative injury suggesting a potential mechanism for the association between low citrulline and ARDS. Further studies are needed to determine whether citrulline supplementation could prevent the development of ARDS in patients with severe sepsis and to determine its role in NOS coupling and function.

  14. Glutamine and citrulline concentrations reflect nitric oxide synthesis in the human nervous system.

    PubMed

    Pérez-Neri, I; Ramírez-Bermúdez, J; Ojeda-López, C; Montes, S; Soto-Hernández, J L; Ríos, C

    2017-08-31

    Although citrulline is produced by nitric oxide (NO) synthase upon activation of the NMDA glutamate receptor, nitrite and nitrate (NOx) concentration is considered the best marker of NO synthesis, as citrulline is also metabolised by other enzymes. This study analyses the correlation between human cerebrospinal fluid NOx and citrulline concentrations in order to determine the extent to which citrulline reflects NO synthesis and glutamatergic neurotransmission. Participants were patients with acute neurological diseases undergoing lumbar puncture (n=240). NOx and amino acid concentrations were determined by HPLC. NOx concentrations did not vary significantly where infection (p=0,110) or inflammation (p=0,349) were present. Multiple regression analysis showed that NOx concentration was correlated with glutamine (r=-0,319, p<0,001) and citrulline concentrations (r=0,293, p=0,005) but not with the citrulline/arginine ratio (r=-0,160, p=0,173). ANCOVA confirmed that NOx concentration was correlated with citrulline concentration (F=7,6, p=0,007) but not with the citrulline/arginine ratio (F=2,2, p=0,136), or presence of infection (F=1,8, p=0,173) or inflammation (F=1,4, p=0,227). No association was found between NOx and arginine or glutamate concentrations. The results suggest that CSF citrulline concentration reflects NOx synthesis to some extent, despite the contribution of other metabolic pathways. In addition, this study shows that glutamine is an important modulator of NO synthase activity, and that arginine and glutamate are not correlated with NOx. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. In the rat, citrullinated autologous fibrinogen is immunogenic but the induced autoimmune response is not arthritogenic

    PubMed Central

    Duplan, V; Foulquier, C; Clavel, C; Al Badine, R; Serre, G; Saoudi, A; Sebbag, M

    2006-01-01

    Conversion of arginyl to citrullyl residues (citrullination) is essential for the formation of the epitopes recognized by rheumatoid arthritis (RA)-associated autoantibodies to citrullinated proteins (ACPA). ACPA are secreted by plasma cells of the rheumatoid synovial tissue where their major target, citrullinated fibrin, is abundant. Although numerous arguments suggest that ACPA play an important role in RA, their pathological relevance remains to be established. In the present study, we assessed the immunogenicity and arthritogenicity of complete Freund's adjuvant-emulsified autologous citrullinated (C-rFBG) or non-citrullinated (NC-rFBG) fibrinogen in Lewis (LEW) and Brown–Norway rats, which exhibit drastic differences in their susceptibility to induced autoimmune diseases. NC-rFBG induced no antibody response. In contrast, a single injection of C-rFBG induced an IgG response directed mainly to citrullinated determinants of rFBG. However, all rat strains remained devoid of clinical and histological signs of arthritis up to 3 months after C-rFBG inoculation. Next, in LEW rats, we tested whether autoimmunity to C-rFBG could aggravate acute ankle arthritis triggered by intra-articular injection of incomplete Freund's adjuvant (IFA). However, such arthritis evolved identically in the presence or absence of anti-C-rFBG autoantibodies. However, IFA-injected joints were devoid of citrullinated fibrin deposits. Therefore, citrullination allows breakdown of immunological tolerance but the autoimmune response developed is not spontaneously arthritogenic. Whether or not it can aggravate arthritis with citrullinated fibrin deposits remains to be evaluated. PMID:16907920

  16. Citrullination of CXCL8 increases this chemokine's ability to mobilize neutrophils into the blood circulation.

    PubMed

    Loos, Tamara; Opdenakker, Ghislain; Van Damme, Jo; Proost, Paul

    2009-10-01

    During the first line defense of an infected host, circulating neutrophils invade the inflamed tissue, whereas mature neutrophils from the bone marrow pool migrate into the blood circulation and from there reinforce tissue infiltration. The CXC chemokine CXCL8, also know as interleukin-8, is a potent attractant of neutrophils. Recently, we discovered a new natural post-translational modification of CXCL8, i.e. the deimination of arginine into citrulline by peptidylarginine deiminases. The ability to provoke leukocytosis was assessed by intravenous administration of citrullinated CXCL8 in rabbits. Adsorption of citrullinated CXCL8 to the Duffy antigen/receptor for chemokines on human or rabbit erythrocytes was evaluated using a competitive binding assay. Finally, surface expression of adhesion molecules was studied after stimulating neutrophils with citrullinated CXCL8. Citrullination of CXCL8 significantly increased this chemokine's ability to recruit neutrophils into the blood circulation. In addition, the competitive binding properties of CXCL8 for the Duffy antigen/receptor for chemokines were impaired upon citrullination. Since the Duffy antigen/receptor for chemokines is an important scavenging receptor for CXCL8 in the blood stream, citrullination may delay CXCL8 clearance from the circulation. Furthermore, the shedding of CD62L (L-selectin) and the upregulation of CD11b (beta2-integrin) protein expression on CXCL8-induced neutrophils were improved by deimination of CXCL8, possibly contributing to the neutrophil egress from the bone marrow. Conversely, surface expression of CD15, the neutrophilic ligand of endothelial selectins, was equally well upregulated by intact and citrullinated CXCL8. These data show that citrullination of CXCL8 enhances leukocytosis, possibly through impaired chemokine clearance from the blood circulation and prolonged presentation to the bone marrow.

  17. Citrulline as a Biomarker for Gastrointestinal-Acute Radiation Syndrome: Species Differences and Experimental Condition Effects

    PubMed Central

    Bujold, K.; Hauer-Jensen, M.; Donini, O.; Rumage, A.; Hartman, D.; Hendrickson, H. P.; Stamatopoulos, J.; Naraghi, H.; Pouliot, M.; Ascah, A.; Sebastian, M.; Pugsley, M. K.; Wong, K.; Authier, S.

    2016-01-01

    Animal models of hematopoietic and gastrointestinal acute radiation syndromes (ARS) have been characterized to develop medical countermeasures. Acute radiation-induced decrease of intestinal absorptive function has been correlated to a decrease in the number of intestinal crypt cells resulting from apoptosis and enterocyte mass reduction. Citrulline, a noncoded amino acid, is produced almost exclusively by the enterocytes of the small intestine. Citrullinemia has been identified as a simple, sensitive and suitable biomarker for radiation-induced injury associated with gastrointestinal ARS (GI-ARS). Here we discuss the effect of radiation on plasma citrulline levels in three different species, C57BL/6 mice, Göttingen minipigs and rhesus nonhuman primates (NHPs), measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). The effects of experimental study conditions such as feeding and anesthesia were also examined on plasma citrulline levels in the NHPs. Both the mice and Göttingen minipigs were partial-body irradiated (PBI) with doses from 13–17 Gy and 8–16 Gy, respectively, whereas NHPs were total-body irradiated (TBI) with doses from 6.72–13 Gy. Blood samples were taken at different time points and plasma citrulline levels were measured in the three species at baseline and after irradiation. Basal plasma citrulline concentrations (mean 6 SEM) in mice and minipigs were 57.8 ± 2.8 μM and 63.1 ± 2.1 μM, respectively. NHPs showed a basal plasma citrulline concentration of 32.6 ± 0.7 μM, very similar to that of humans (~40 μM). Plasma citrulline progressively decreased after irradiation, reaching nadir values between day 3.5 and 7. The onset of citrulline recovery was observed earlier at lower radiation doses, while only partial citrulline recovery was noted at higher radiation doses in minipigs and NHPs, complete recovery was noted in mice at all doses. Plasma citrulline levels in NHPs anesthetized with ketamine and acepromazine

  18. L-citrulline provides a novel strategy for treating chronic pulmonary hypertension in newborn infants

    PubMed Central

    Fike, Candice D.; Summar, Marshall; Aschner, Judy L.

    2014-01-01

    Effective therapies are urgently needed for infants with forms of pulmonary hypertension that develop or persist beyond the first week of life. The L-arginine nitric oxide (NO) precursor, L-citrulline, improves NO signalling and ameliorates pulmonary hypertension in newborn animal models. In vitro studies demonstrate that manipulating L-citrulline transport alters NO production. Conclusion Strategies that increase the supply and transport of L-citrulline merit pursuit as novel approaches to managing infants with chronic, progressive pulmonary hypertension. PMID:24862864

  19. Citrulline as a Biomarker for Gastrointestinal-Acute Radiation Syndrome: Species Differences and Experimental Condition Effects.

    PubMed

    Bujold, K; Hauer-Jensen, M; Donini, O; Rumage, A; Hartman, D; Hendrickson, H P; Stamatopoulos, J; Naraghi, H; Pouliot, M; Ascah, A; Sebastian, M; Pugsley, M K; Wong, K; Authier, S

    2016-07-01

    Animal models of hematopoietic and gastrointestinal acute radiation syndromes (ARS) have been characterized to develop medical countermeasures. Acute radiation-induced decrease of intestinal absorptive function has been correlated to a decrease in the number of intestinal crypt cells resulting from apoptosis and enterocyte mass reduction. Citrulline, a noncoded amino acid, is produced almost exclusively by the enterocytes of the small intestine. Citrullinemia has been identified as a simple, sensitive and suitable biomarker for radiation-induced injury associated with gastrointestinal ARS (GI-ARS). Here we discuss the effect of radiation on plasma citrulline levels in three different species, C57BL/6 mice, Göttingen minipigs and rhesus nonhuman primates (NHPs), measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). The effects of experimental study conditions such as feeding and anesthesia were also examined on plasma citrulline levels in the NHPs. Both the mice and Göttingen minipigs were partial-body irradiated (PBI) with doses from 13-17 Gy and 8-16 Gy, respectively, whereas NHPs were total-body irradiated (TBI) with doses from 6.72-13 Gy. Blood samples were taken at different time points and plasma citrulline levels were measured in the three species at baseline and after irradiation. Basal plasma citrulline concentrations (mean ± SEM) in mice and minipigs were 57.8 ± 2.8 μM and 63.1 ± 2.1 μM, respectively. NHPs showed a basal plasma citrulline concentration of 32.6 ± 0.7 μM, very similar to that of humans (∼40 μM). Plasma citrulline progressively decreased after irradiation, reaching nadir values between day 3.5 and 7. The onset of citrulline recovery was observed earlier at lower radiation doses, while only partial citrulline recovery was noted at higher radiation doses in minipigs and NHPs, complete recovery was noted in mice at all doses. Plasma citrulline levels in NHPs anesthetized with ketamine and acepromazine significantly

  20. Lungs, joints and immunity against citrullinated proteins in rheumatoid arthritis.

    PubMed

    Catrina, Anca I; Ytterberg, A Jimmy; Reynisdottir, Gudrun; Malmström, Vivianne; Klareskog, Lars

    2014-11-01

    Rheumatoid arthritis (RA) is a prototype for a criterion-defined inflammatory disease, for which the aetiology and initial molecular pathogenesis has been elusive for a long time. We describe in this Review how studies on the interplay between specific immunity, alongside genetic and environmental predisposing factors, provide new tools to understand the molecular basis of distinct subsets of the disease. A particular emphasis is on the possibility that pathogenic immune reactions might be initiated at other sites than the joints, and that the lungs could harbour such sites. New data strengthen this concept, showing that local immunity towards citrullinated proteins and accompanying inflammation might be present in the lungs early during disease development. This progress makes RA an interesting case for the future development of therapies that might be directed against disease-inducing immunity even before inflammation and destruction of joints has begun.

  1. Supplemental citrulline is more efficient than arginine to increase systemic arginine availability in mice

    USDA-ARS?s Scientific Manuscript database

    Arginine is considered an essential amino acid in various (patho)physiological conditions of high demand. However, dietary arginine supplementation (ARG) suffers various drawbacks, including extensive first-pass extraction. Citrulline supplementation (CIT) may be a better alternative than arginine, ...

  2. The effects of watermelon (Citrullus lanatus) extracts and L-citrulline on rat uterine contractility.

    PubMed

    Munglue, Phukphon; Eumkep, Graingsak; Wray, Susan; Kupittayanant, Sajeera

    2013-04-01

    In uterine smooth muscle, the effects of watermelon and its citrulline content are unknown. The aims of this study were therefore, to determine the effects of watermelon extract and citrulline on the myometrium and to investigate their mechanisms of action. The effects of extracts of watermelon flesh and rind and L-citrulline (64 μmol/L) were evaluated on 3 types of contractile activity; spontaneous, those elicited by potassium chloride (KCl) depolarization, or oxytocin (10 nmol/L) application in isolated rat uterus. Inhibitors of nitric oxide (NO) and its mechanisms of action, N ω-Nitro-L-arginine methyl ester hydrochloride (L-NAME, 100 μmol/L), LY83583 (1 μmol/L), and tetraethylamonium chloride (5 mmol/L), as well as Ca signaling pathways, were determined. Both flesh and rind extracts significantly decreased the force produced by all 3 mechanisms, in a dose-dependent manner. The extracts could also significantly decrease the force under conditions of sustained high Ca levels (depolarization and agonist) and when the force was produced only by sarcoplasmic reticulum (SR) Ca release. L-citrulline produced the same effects on force as watermelon extracts. With submaximal doses of extract, the additive effects of L-citrulline were found. The inhibitory effects of extracts and L-citrulline were reversed upon the addition of NO inhibitors, and pretreatment of tissues with these inhibitors prevented the actions of both extracts and L-citrulline. Thus, these data show that watermelon and citrulline are potent tocolytics, decreasing the force produced by calcium entry and SR release and arising by different pathways, including oxytocin stimulation. Their major mechanism is to stimulate the NO-cyclic guanosine monophosphate (cGMP) relaxant pathway.

  3. Extensive Citrullination Promotes Immunogenicity of HSP90 through Protein Unfolding and Exposure of Cryptic Epitopes.

    PubMed

    Travers, Timothy S; Harlow, Lisa; Rosas, Ivan O; Gochuico, Bernadette R; Mikuls, Ted R; Bhattacharya, Sanjoy K; Camacho, Carlos J; Ascherman, Dana P

    2016-09-01

    Post-translational protein modifications such as citrullination have been linked to the breach of immune tolerance and clinical autoimmunity. Previous studies from our laboratory support this concept, demonstrating that autoantibodies targeting citrullinated isoforms of heat shock protein 90 (HSP90) are associated with rheumatoid arthritis complicated by interstitial lung disease. To further explore the relationship between citrullination and structural determinants of HSP90 immunogenicity, we employed a combination of ELISA-based epitope profiling, computational modeling, and mass-spectrometric sequencing of peptidylarginine deiminase (PAD)-modified protein. Remarkably, ELISAs involving selected citrullinated HSP90β/α peptides identified a key epitope corresponding to an internal Arg residue (R502 [HSP90β]/R510 [HSP90α]) that is normally buried within the crystal structure of native/unmodified HSP90. In vitro time/dose-response experiments reveal an ordered pattern of PAD-mediated deimination events culminating in citrullination of R502/R510. Conventional as well as scaled molecular dynamics simulations further demonstrate that citrullination of selected Arg residues leads to progressive disruption of HSP90 tertiary structure, promoting exposure of R502/R510 to PAD modification and subsequent autoantibody binding. Consistent with this process, ELISAs incorporating variably deiminated HSP90 as substrate Ag indicate a direct relationship between the degree of citrullination and the level of ex vivo Ab recognition. Overall, these data support a novel structural paradigm whereby citrullination-induced shifts in protein structure generate cryptic epitopes capable of bypassing B cell tolerance in the appropriate genetic context. Copyright © 2016 by The American Association of Immunologists, Inc.

  4. Plasma citrulline: A marker of enterocyte mass in villous atrophy-associated small bowel disease.

    PubMed

    Crenn, Pascal; Vahedi, Kouroche; Lavergne-Slove, Anne; Cynober, Luc; Matuchansky, Claude; Messing, Bernard

    2003-05-01

    Plasma citrulline, a nonprotein amino acid produced by enterocytes, was suggested as a marker of remnant enterocyte mass in patients with short bowel. Our objective was to evaluate citrulline as a marker of severity and extent of villous atrophy in patients without intestinal resection. Forty-two patients with celiac disease and 10 patients with non-celiac villous atrophy disease were studied by plasma postabsorptive citrulline and biological dosages, biopsies of proximal (duodenojejunal) small bowel and distal ileum (n = 25), or measurement of vitamin B(12) absorption (n = 4). Nine patients were reevaluated after following a gluten-free diet for 1 year. Controls were 51 healthy subjects and 10 severely malnourished patients with anorexia nervosa with no intestinal mucosal abnormalities. Plasma citrulline concentration was lower (P < 0.001) in patients with villous atrophy (24 +/- 13 micromol/L) than in healthy subjects (40 +/- 10 micromol/L) and patients with anorexia nervosa (39 +/- 9 micromol/L). Three thresholds were individualized: <10 micromol/L for patients with diffuse total villous atrophy (n = 10), 10-20 micromol/L for patients with proximal-only total villous atrophy (n = 12), and 20-30 micromol/L for patients with partial villous atrophy (n = 10). Plasma citrulline concentration was correlated to the severity and extent of villous atrophy (r = 0.81; P < 0.001) and to albuminemia (r = 0.47; P < 0.01). Receiver operating characteristic curves indicated that plasma citrulline concentration was the best biological variable to predict villous atrophy. Following a 1-year gluten-free diet, plasma citrulline concentration increased in histologically responsive (n = 6) but not in unresponsive (n = 3) patients. In patient villous atrophy diseases, plasma citrulline concentration may prove to be a simple and reliable marker of reduced enterocyte mass.

  5. Antibodies to several citrullinated antigens are enriched in the joints of rheumatoid arthritis patients.

    PubMed

    Snir, Omri; Widhe, Mona; Hermansson, Monika; von Spee, Caroline; Lindberg, Johan; Hensen, Sanne; Lundberg, Karin; Engström, Ake; Venables, Patrick J W; Toes, René E M; Holmdahl, Rikard; Klareskog, Lars; Malmström, Vivianne

    2010-01-01

    High titers of specific anti-citrullinated protein antibodies (ACPAs) are frequently present in the serum of rheumatoid arthritis (RA) patients, but their presence in synovial fluid is less well characterized. The purpose of this study was to compare the levels of antibody to 4 well-defined citrullinated candidate RA autoantigens in serum and synovial fluid and to determine whether antibodies to one citrullinated antigen are dominant over another. Furthermore, we studied their relationships with mutated citrullinated vimentin (MCV), a newly identified RA-specific serum assay, and the classic cyclic citrullinated peptide (CCP) in the synovial fluid of well-defined HLA-DR groups. Paired serum and synovial fluid samples from 290 RA patients and serum samples from 100 age- and sex-matched healthy controls were analyzed for the presence of anti-MCV and anti-CCP antibodies and for reactivity to citrullinated fibrinogen, alpha-enolase, type II collagen, and vimentin. A total of 219 of the 290 patients were genotyped for the HLA-DR shared epitope alleles. Significantly higher proportions of antibodies against all RA-associated citrullinated antigens were found in synovial fluid as compared with serum. This was also true for the MCV and CCP responses but not for non-RA-associated anti-tetanus toxoid antibodies. As expected, we found a high correlation between citrullinated vimentin and MCV responses. All synovial fluid ACPAs were predominantly associated with HLA-DRB1*04 alleles and were confined to the CCP+/MCV+ subset of patients. MCV and CCP positivity represent a similar subset of RA patients, whereas ACPAs with different fine specificities fall into subgroups of anti-CCP+/anti-MCV+ patients. The levels of all specific ACPAs were elevated in synovial fluid, suggesting that there is local antibody production and/or retention of ACPAs at the site of inflammation governed by RA-predisposing genes.

  6. Extracellular citrullination inhibits the function of matrix associated TGF-β.

    PubMed

    Sipilä, Kalle H; Ranga, Vipin; Rappu, Pekka; Torittu, Annamari; Pirilä, Laura; Käpylä, Jarmo; Johnson, Mark S; Larjava, Hannu; Heino, Jyrki

    2016-09-01

    In inflammatory arthritis peptidyl arginine deiminase (PAD) enzymes can citrullinate arginine residues in extracellular matrix (ECM) proteins, such as collagens and fibronectin. This may lead to the generation of anti-citrullinated protein antibodies, important diagnostic markers in rheumatoid arthritis. In addition, the citrullination may directly affect protein function. Based on structural analysis, we found that most ECM-associated growth factors (GFs) have arginine residues in their receptor recognition sites. Thus, they are potential functional targets of extracellular citrullination. To examine this further, we focused on the citrullination of transforming growth factor-βs (TGF-β), well-known ECM-associated GFs. PAD-treatment of CHO-LTBP1 cell derived matrix, rich with TGF-β, decreased the level of TGF-β activity as detected by HaCaT and MLEC-PAI-1/Lu reporter cells. Additional experiments indicated that PAD-treatment inhibits the integrin-mediated TGF-β activation since PAD-treatment decreased the binding of integrin αVβ6 ectodomain as well as integrin-mediated spreading of MG-63 and HaCaT cells to β1-latency associated peptide (TGF-β1 LAP). The citrullination of the RGD site, an important integrin recognition motif, was confirmed by mass spectrometry. Furthermore, the citrullination of active TGF-β1 inhibited its binding to recombinant TGF-β receptor II, and prevented its ability to activate TGF-β signaling. Thus, extracellular PAD activity can affect the function of ECM-associated growth factors by different mechanisms. Importantly, the citrullination of both latent and active TGF-β has the potency to regulate the inflammatory process.

  7. The increased ability to present citrullinated peptides is not unique to HLA-SE molecules: arginine-to-citrulline conversion also enhances peptide affinity for HLA-DQ molecules.

    PubMed

    Kampstra, Arieke S B; van Heemst, Jurgen; Moustakas, Antonis K; Papadopoulos, George K; Huizinga, Tom W J; Toes, René E M

    2016-11-03

    Presentation of citrullinated neo-epitopes by HLA-DRB1 molecules that carry the shared epitope (SE) sequence was proposed to explain the association between HLA and seropositive RA. Although it is shown that several HLA-DRB1-SE molecules display enhanced binding affinities for citrullinated ligands, the ability of other HLA molecules to present citrullinated epitopes has not been investigated in a systematic manner. To better understand the HLA-RA connection, we aimed to investigate if the enhanced capacity to present arginine-to-citrulline-converted peptides is unique for HLA-SE alleles. We selected four HLA molecules (one HLA-DR and three HLA-DQ molecules) that could potentially prefer citrulline over arginine residues in specific pockets and in addition two HLA-SE alleles as a method validation control. The affinity of peptides containing arginine/citrulline residues at positions interacting with the various peptide-binding pockets was compared by HLA class II peptide affinity assays. Pocket 4 of HLA-DRB1*04:04 and -DRB1*04:05 displayed a preference for citrulline over arginine, a property found in other pockets as well. HLA-DRB1*03:01 did not display an enhanced affinity for peptides containing a citrulline. In contrast, several peptide-binding pockets of the analyzed HLA-DQ molecules showed enhanced affinities for citrulline compared to arginine residues: i.e., pockets 4, 6, 7, and 9 of HLA-DQ2 and pockets 1, 6, and 9 of HLA-DQ7 and HLA-DQ8. Arginine-to-citrulline conversion of peptides can also enhance the binding affinity for non-HLA-SE molecules. Hence the capacity to present citrullinated neo-epitopes is not confined to HLA-SE molecules, opening the possibility that also other HLA molecules could potentiate a possible breach of T cell tolerance toward citrullinated antigens.

  8. Association of Anti-Citrullinated Peptide Antibodies With Coronary Artery Calcification in Rheumatoid Arthritis.

    PubMed

    Geraldino-Pardilla, Laura; Giles, Jon T; Sokolove, Jeremy; Zartoshti, Afshin; Robinson, William H; Budoff, Matthew; Detrano, Robert; Bokhari, Sabahat; Bathon, Joan M

    2017-08-01

    Citrullinated proteins have been found within atherosclerotic plaque. However, studies evaluating the association between anti-citrullinated protein antibodies (ACPAs) and imaging measures of atherosclerosis in patients with rheumatoid arthritis (RA) have been limited to seroreactive citrullinated fibrinogen or citrullinated vimentin and have rendered contradictory results. Therefore, our objective was to evaluate this association using an extended panel of ACPAs in a larger sample of RA patients without clinical cardiovascular disease (CVD). ACPAs were identified using a custom Bio-Plex bead assay in 270 patients from 2 independent RA cohorts without clinical CVD, with the first one consisting of 195 patients and the other of 75 patients. Coronary artery calcium (CAC) was assessed by computed tomography as a measure of coronary artery disease. High levels of anti-citrullinated histone H2B antibodies were strongly associated with higher CAC scores, compared with lower antibody levels (P = 0.001); this remained significant after adjustment for traditional CV and RA-specific risk factors (P = 0.03). No association between levels of ACPAs and CAC progression at 3 years was seen (P = 0.09); however, the number of progressors was small (n = 92). Higher levels of ACPAs targeting Cit-histone H2B were associated with higher CAC scores when compared to lower antibody levels, suggesting a potential role for histone citrullination seroreactivity in atherosclerosis. © 2016, American College of Rheumatology.

  9. Circadian and postprandial variation in plasma citrulline concentration in healthy dogs.

    PubMed

    Dahan, Julien M; Giron, Celine; Concordet, Didier; Dossin, Olivier

    2016-03-01

    To evaluate circadian and postprandial variations in plasma citrulline concentration in healthy dogs. 8 healthy Beagles. Blood samples were collected from dogs after 12 hours of food withholding (0 hours; 8:00 am) and then every 2 hours for 12 hours (until 8:00 pm) and again at 24 hours (8:00 am the next day). The same protocol was repeated, with the only difference being that a meal was given immediately after the 0-hour sample collection point. Plasma citrulline concentration was measured by ion exchange chromatography. No significant difference in plasma citrulline concentration was identified among measurement points when food was withheld. Mean ± SD plasma citrulline concentration at 4 hours (72.2 ± 12.7 μmol/L) and 24 hours (56.1 ± 12.5 μmol/L) after dogs were fed was significantly different from that at 0 hours (64.4 ± 12.7 μmol/L). Plasma citrulline concentration had no circadian variation in unfed dogs but increased significantly in fed dogs 4 hours after a meal. Therefore, food should be withheld from dogs for 8 to 12 hours before blood sample collection for measurement of citrulline concentration.

  10. Is there a link between carbamylation and citrullination in periodontal disease and rheumatoid arthritis?

    PubMed

    Bright, R; Proudman, S M; Rosenstein, E D; Bartold, P M

    2015-06-01

    The remarkable similarity in inflammatory response and pathology of periodontal disease and rheumatoid arthritis has been recognized for several decades. However, how these two disease may be interrelated has been less clear. During the pathogenesis of rheumatoid arthritis there is a preclinical immunological phase which precedes the clinical manifestation of rheumatoid arthritis. During this phase serum autoantibodies appear many years before the clinical signs and symptoms of rheumatoid arthritis become apparent. To date, the two best studied autoantibodies have been rheumatoid factor and anti-citrullinated protein antibodies (ACPA). Of these the production of ACPA has been considered very important due to their high predictive value in future manifestation of rheumatoid arthritis. Citrullination is a common post-translational modification of proteins based on the enzymatic conversion of arginine into citrulline. Extra-articular citrullination and production of ACPA, as a priming immunological experience, is well documented in many tissues including the inflamed gingival tissues associated with periodontal disease. More recently, carbamylation of proteins has also been implicated in the pathogenesis of rheumatoid arthritis in a manner similar to citrullination. Carbamylation is a post translational modification of proteins by an enzyme-independent modification of lysine residues against which autoantibodies are subsequently induced. In this article we hypothesise that, like citrullination, carbamylation of proteins and associated antibody production during the gingival inflammation associated with gingivitis and periodontitis may play a role in the pathogenesis of rheumatoid arthritis.

  11. Citrulline is an important biochemical indicator in tolerance to saline and drought stresses in melon.

    PubMed

    Kusvuran, Sebnem; Dasgan, H Yildiz; Abak, Kazim

    2013-01-01

    Salt- and drought-induced alterations in citrulline were assessed in 4 local melon genotypes, 2 sensitive (CU-52, CU-94) and 2 tolerant (CU-196, CU-280), grown in vermiculite in a growth chamber. Salt and drought stresses were started using 30-day-old plants, with 250 mM NaCl and 45 mM PEG (-1.0 MPa) and continued for 12 days. After 12 days under salt and drought conditions, the citrulline contents were increased in the tolerant CU 196 to 25.10  μ mol gDW⁻¹ and 24.10  μ mol gDW⁻¹ for salt and drought stresses, respectively. However, the citrulline contents of the sensitive CU-52 were 11.68  μ mol gDW⁻¹ and 11.76  μ mol gDW⁻¹ for salt and drought, respectively. The striking alteration was obtained in the citrulline accumulation. The tolerant melons accumulated 2 times more citrulline than the sensitive melons. For assessing or screening melon genotypes in a large number of accessions or breeding lines for their tolerance to salinity and drought during their young plant stage, the amount of citrulline accumulation in response to the given treatments might be considered as a novel biochemical indicator of interest in early selection studies.

  12. Induction of osteoclastogenesis and bone loss by human autoantibodies against citrullinated vimentin

    PubMed Central

    Harre, Ulrike; Georgess, Dan; Bang, Holger; Bozec, Aline; Axmann, Roland; Ossipova, Elena; Jakobsson, Per-Johan; Baum, Wolfgang; Nimmerjahn, Falk; Szarka, Eszter; Sarmay, Gabriella; Krumbholz, Grit; Neumann, Elena; Toes, Rene; Scherer, Hans-Ulrich; Catrina, Anca Irinel; Klareskog, Lars; Jurdic, Pierre; Schett, Georg

    2012-01-01

    Autoimmunity is complicated by bone loss. In human rheumatoid arthritis (RA), the most severe inflammatory joint disease, autoantibodies against citrullinated proteins are among the strongest risk factors for bone destruction. We therefore hypothesized that these autoantibodies directly influence bone metabolism. Here, we found a strong and specific association between autoantibodies against citrullinated proteins and serum markers for osteoclast-mediated bone resorption in RA patients. Moreover, human osteoclasts expressed enzymes eliciting protein citrullination, and specific N-terminal citrullination of vimentin was induced during osteoclast differentiation. Affinity-purified human autoantibodies against mutated citrullinated vimentin (MCV) not only bound to osteoclast surfaces, but also led to robust induction of osteoclastogenesis and bone-resorptive activity. Adoptive transfer of purified human MCV autoantibodies into mice induced osteopenia and increased osteoclastogenesis. This effect was based on the inducible release of TNF-α from osteoclast precursors and the subsequent increase of osteoclast precursor cell numbers with enhanced expression of activation and growth factor receptors. Our data thus suggest that autoantibody formation in response to citrullinated vimentin directly induces bone loss, providing a link between the adaptive immune system and bone. PMID:22505457

  13. Citrulline Supplementation Improves Organ Perfusion and Arginine Availability under Conditions with Enhanced Arginase Activity.

    PubMed

    Wijnands, Karolina A P; Meesters, Dennis M; van Barneveld, Kevin W Y; Visschers, Ruben G J; Briedé, Jacob J; Vandendriessche, Benjamin; van Eijk, Hans M H; Bessems, Babs A F M; van den Hoven, Nadine; von Wintersdorff, Christian J H; Brouckaert, Peter; Bouvy, Nicole D; Lamers, Wouter H; Cauwels, Anje; Poeze, Martijn

    2015-06-29

    Enhanced arginase-induced arginine consumption is believed to play a key role in the pathogenesis of sickle cell disease-induced end organ failure. Enhancement of arginine availability with L-arginine supplementation exhibited less consistent results; however, L-citrulline, the precursor of L-arginine, may be a promising alternative. In this study, we determined the effects of L-citrulline compared to L-arginine supplementation on arginine-nitric oxide (NO) metabolism, arginine availability and microcirculation in a murine model with acutely-enhanced arginase activity. The effects were measured in six groups of mice (n = 8 each) injected intraperitoneally with sterile saline or arginase (1000 IE/mouse) with or without being separately injected with L-citrulline or L-arginine 1 h prior to assessment of the microcirculation with side stream dark-field (SDF)-imaging or in vivo NO-production with electron spin resonance (ESR) spectroscopy. Arginase injection caused a decrease in plasma and tissue arginine concentrations. L-arginine and L-citrulline supplementation both enhanced plasma and tissue arginine concentrations in arginase-injected mice. However, only the citrulline supplementation increased NO production and improved microcirculatory flow in arginase-injected mice. In conclusion, the present study provides for the first time in vivo experimental evidence that L-citrulline, and not L-arginine supplementation, improves the end organ microcirculation during conditions with acute arginase-induced arginine deficiency by increasing the NO concentration in tissues.

  14. Citrulline as a biomarker in the non-human primate total- and partial-body irradiation models: correlation of circulating citrulline to acute and prolonged gastrointestinal injury

    PubMed Central

    Jones, Jace W.; Bennett, Alexander; Carter, Claire L.; Tudor, Gregory; Hankey, Kim G.; Farese, Ann M.; Booth, Catherine; MacVittie, Thomas J.; Kane, Maureen A.

    2015-01-01

    The use of plasma citrulline as a biomarker for acute and prolonged gastrointestinal injury via exposure to total- and partial-body irradiation (6 MV LINAC-derived photons; 0.80 Gy min−1) in nonhuman primate models was investigated. The irradiation exposure covered gastrointestinal injuries spanning lethal, mid-lethal, and sub-lethal doses. The acute gastrointestinal injury was assessed via measurement of plasma citrulline and small intestinal histopathology over the first 15 days following radiation exposure and included total-body irradiation at 13.0 Gy, 10.5 Gy, and 7.5 Gy and partial-body irradiation at 11.0 Gy with 5% bone marrow sparing. The dosing schemes of 7.5 Gy total-body irradiation and 11.0 Gy partial-body irradiation included time points out to day 60 and day 180, respectively, which allowed for correlation of plasma citrulline to prolonged gastrointestinal injury and survival. Plasma citrulline values were radiation-dependent for all radiation doses under consideration with nadir values ranging from 63–80 % lower than radiation-naïve NHP plasma. The nadir values were observed at day 5 to 7 post irradiation. Longitudinal plasma citrulline profiles demonstrated prolonged gastrointestinal injury resulting from acute high-dose irradiation had long lasting effects on enterocyte function. Moreover, plasma citrulline did not discriminate between total-body or partial-body irradiation over the first 15 days following irradiation and was not predictive of survival based on the radiation models considered herein. PMID:26425904

  15. Citrullination of proteins: a common post-translational modification pathway induced by different nanoparticles in vitro and in vivo

    PubMed Central

    Mohamed, Bashir M; Verma, Navin K; Davies, Anthony M; McGowan, Aoife; Crosbie-Staunton, Kieran; Prina-Mello, Adriele; Kelleher, Dermot; Botting, Catherine H; Causey, Corey P; Thompson, Paul R; Pruijn, Ger JM; Kisin, Elena R; Tkach, Alexey V; Shvedova, Anna A; Volkov, Yuri

    2012-01-01

    Aim Rapidly expanding manufacture and use of nanomaterials emphasize the requirements for thorough assessment of health outcomes associated with novel applications. Post-translational protein modifications catalyzed by Ca2+-dependent peptidylargininedeiminases have been shown to trigger immune responses including autoantibody generation, a hallmark of immune complexes deposition in rheumatoid arthritis. Therefore, the aim of the study was to assess if nanoparticles are able to promote protein citrullination. Materials & methods Human A549 and THP-1 cells were exposed to silicon dioxide, carbon black or single-walled carbon nanotubes. C57BL/6 mice were exposed to respirable single-walled carbon nanotubes. Protein citrullination, peptidylargininedeiminases activity and target proteins were evaluated. Results The studied nanoparticles induced protein citrullination both in cultured human cells and mouse lung tissues. Citrullination occurred via the peptidylargininedeiminase-dependent mechanism. Cytokeratines 7, 8, 18 and plectins were identified as intracellular citrullination targets. Conclusion Nanoparticle exposure facilitated post-translational citrullination of proteins. PMID:22625207

  16. Anti-citrullinated protein antibodies in the diagnosis of rheumatoid arthritis (RA): diagnostic performance of automated anti-CCP-2 and anti-CCP-3 antibodies assays.

    PubMed

    Vos, Ine; Van Mol, Christof; Trouw, Leendert A; Mahler, Michael; Bakker, Jaap A; Van Offel, Jan; De Clerck, Luc; Huizinga, Tom W

    2017-07-01

    This study compares the diagnostic performance of a second generation anti-cyclic citrullinated peptide antibody (CCP2) with a third generation anti-CCP antibodies assay (CCP3), as well as the combination of both tests. Serum samples of 127 patients were analyzed. IgG anti-CCP 2 and IgM rheumatoid factor were determined by EliA™ technique on a Phadia 250 instrument (Thermo Fisher Scientific), anti-CCP3 by the Quanta Flash™ anti-CCP3 IgG kit, BIO-FLASH Rapid Response Chemiluminscence Analyzer (INOVA Diagnostics). Diagnostic performance was compared using ROC-curves, sensitivity, specificity, likelihood ratios, and predictive values. Logistic regressions were used to investigate whether using both tests (anti-CCP2 and anti-CCP3) gives a better prediction of rheumatoid arthritis. At the manufacturer's cut-offs sensitivity and specificity were 79.4 and 61.0% for CCP3 and 80.9 and 69.5% for CCP2. No significant differences could be observed regarding the areas under the curve (AUC) of both ROC-curves. The optimal cut-off point for CCP2 was 10.5 U/ml (sensitivity of 75.0% and specificity of 80.0%) and 5.6 U/ml for CCP3 (sensitivity of 86.9% and specificity of 61.0%). Binary logistic regressions indicated that the likelihood of having rheumatoid arthritis (RA) is significantly higher when testing positive on both CCP2 and CCP3 compared to CCP2 or CCP3 alone. In our cohort, comparable performance was found between the two CCP assays. Positivity for both CCP2 and CCP3 resulted in the most specific identification of RA patients. In patients with joint complaints suspected of having RA and with a weakly positive CCP 2 (≥7 and ≤16 U/ml) CCP3 testing could be of additive value for diagnosing RA.

  17. Citrulline increases cholesterol efflux from macrophages in vitro and ex vivo via ATP-binding cassette transporters

    PubMed Central

    Uto-Kondo, Harumi; Ayaori, Makoto; Nakaya, Kazuhiro; Takiguchi, Shunichi; Yakushiji, Emi; Ogura, Masatsune; Terao, Yoshio; Ozasa, Hideki; Sasaki, Makoto; Komatsu, Tomohiro; Sotherden, Grace Megumi; Hosoai, Tamaki; Sakurada, Masami; Ikewaki, Katsunori

    2014-01-01

    Reverse cholesterol transport (RCT) is a mechanism critical to the anti-atherogenic property of HDL. Although citrulline contributes to the amelioration of atherosclerosis via endothelial nitric oxide production, it remains unclear whether it affects RCT. This study was undertaken to clarify the effects of citrulline on expressions of specific transporters such as ATP binding cassette transporters (ABC)A1 and ABCG1, and the cholesterol efflux from macrophages to apolipoprotein (apo) A-I or HDL in vitro and ex vivo. Citrulline increased ABCA1 and ABCG1 mRNA and protein levels in THP-1 macrophages, translating into enhanced apoA-I- and HDL-mediated cholesterol efflux. In the human crossover study, 8 healthy male volunteers (age 30–49 years) consumed either 3.2 g/day citrulline or placebo for 1 week. Citrulline consumption brought about significant increases in plasma levels of citrulline and arginine. Supporting the in vitro data, monocyte-derived macrophages (MDM) differentiated under autologous post-citrulline sera demonstrated enhancement of both apoA-I- and HDL-mediated cholesterol efflux through increased ABCA1 and ABCG1 expressions, compared to MDM differentiated under pre-citrulline sera. However, the placebo did not modulate these parameters. Therefore, in addition to improving endothelium function, citrulline might have an anti-atherogenic property by increasing RCT of HDL. PMID:25120277

  18. Citrulline a More Suitable Substrate than Arginine to Restore NO Production and the Microcirculation during Endotoxemia

    PubMed Central

    Wijnands, Karolina A. P.; Vink, Hans; Briedé, Jacob J.; van Faassen, Ernst E.; Lamers, Wouter H.; Buurman, Wim A.; Poeze, Martijn

    2012-01-01

    Background Impaired microcirculation during endotoxemia correlates with a disturbed arginine-nitric oxide (NO) metabolism and is associated with deteriorating organ function. Improving the organ perfusion in endotoxemia, as often seen in patients with severe infection or systemic inflammatory response syndrome (SIRS) is, therefore, an important therapeutic target. We hypothesized that supplementation of the arginine precursor citrulline rather than arginine would specifically increase eNOS-induced intracellular NO production and thereby improve the microcirculation during endotoxemia. Methodology/Principal Findings To study the effects of L-Citrulline and L-Arginine supplementation on jejunal microcirculation, intracellular arginine availability and NO production in a non-lethal prolonged endotoxemia model in mice. C57/Bl6 mice received an 18 hrs intravenous infusion of endotoxin (LPS, 0.4 µg•g bodyweight−1•h−1), combined with either L-Citrulline (6.25 mg•h-1), L-Arginine (6.25 mg•h−1), or L-Alanine (isonitrogenous control; 12.5 mg•h−1) during the last 6 hrs. The control group received an 18 hrs sterile saline infusion combined with L-Alanine or L-Citrulline during the last 6 hrs. The microcirculation was evaluated at the end of the infusion period using sidestream dark-field imaging of jejunal villi. Plasma and jejunal tissue amino-acid concentrations were measured by HPLC, NO tissue concentrations by electron-spin resonance spectroscopy and NOS protein concentrations using Western blot. Conclusion/Significance L-Citrulline supplementation during endotoxemia positively influenced the intestinal microvascular perfusion compared to L-Arginine-supplemented and control endotoxemic mice. L-Citrulline supplementation increased plasma and tissue concentrations of arginine and citrulline, and restored intracellular NO production in the intestine. L-Arginine supplementation did not increase the intracellular arginine availability. Jejunal tissues in the

  19. L-citrulline supplementation reverses the impaired airway relaxation in neonatal rats exposed to hyperoxia

    PubMed Central

    2012-01-01

    Background Hyperoxia is shown to impair airway relaxation via limiting L-arginine bioavailability to nitric oxide synthase (NOS) and reducing NO production as a consequence. L-arginine can also be synthesized by L-citrulline recycling. The role of L-citrulline supplementation was investigated in the reversing of hyperoxia-induced impaired relaxation of rat tracheal smooth muscle (TSM). Methods Electrical field stimulation (EFS, 2–20 V)-induced relaxation was measured under in vitro conditions in preconstricted tracheal preparations obtained from 12 day old rat pups exposed to room air or hyperoxia (>95% oxygen) for 7 days supplemented with L-citrulline or saline (in vitro or in vivo). The role of the L-citrulline/L-arginine cycle under basal conditions was studied by incubation of preparations in the presence of argininosuccinate synthase (ASS) inhibitor [α-methyl-D, L-aspartate, 1 mM] or argininosuccinate lyase inhibitor (ASL) succinate (1 mM) and/or NOS inhibitor [Nω-nitro-L-arginine methyl ester; 100 μM] with respect to the presence or absence of L-citrulline (2 mM). Results Hyperoxia impaired the EFS-induced relaxation of TSM as compared to room air control (p < 0.001; 0.5 ± 0.1% at 2 V to 50.6 ± 5.7% at 20 V in hyperoxic group: 0.7 ± 0.2 at 2 V to 80.0 ± 5.6% at 20 V in room air group). Inhibition of ASS or ASL, and L-citrulline supplementation did not affect relaxation responses under basal conditions. However, inhibition of NOS significantly reduced relaxation responses (p < 0.001), which were restored to control level by L-citrulline. L-citrulline supplementation in vivo and in vitro also reversed the hyperoxia-impaired relaxation. The differences were significant (p <0.001; 0.8 ± 0.3% at 2 V to 47.1 ± 4.1% at 20 V without L-citrulline; 0.9 ± 0.3% at 2 V to 68.2 ± 4.8% at 20 V with L-citrulline). Inhibition of ASS or ASL prevented this effect of L-citrulline. Conclusion The

  20. Anti-citrullinated peptides as autoantigens in rheumatoid arthritis-relevance to treatment.

    PubMed

    Sakkas, Lazaros I; Bogdanos, Dimitrios P; Katsiari, Christina; Platsoucas, Chris D

    2014-11-01

    Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by the presence of rheumatoid factor (RF) and anti-citrullinated protein/peptide autoantibodies (ACPAs). Citrulline derives from arginine by peptidyl arginine deiminases, and ACPAs are directed against different citrullinated antigens, including fibrinogen, fibronectin, α-enolase, collagen type II, histones. ACPAs are present in two thirds of RA patients have higher specificity than RF for RA, and are associated with joint radiographic damage and extra-articular manifestations and they are detected years before the onset clinical arthritis. Recent studies suggest that citrullinated antigens are most likely arthritogenic autoantigens in RA. ACPA production is associated with the HLA-DRB1 shared epitope (HLA-DRB1 SE) and accounts for the well-known RA-HLA-DRB1 SE association, as T cells recognize citrullinated peptides. Smoking and periodontitis, known environmental risk factors for RA promote protein citrullination and ACPA production. Cirullinated proteins are capable of inducing arthritis in transgenic mice carrying HLA-DRB1 SE genes, and ACPAs induce macrophage TNF-α production, osteoclastogenesis and complement activation. They also induce the formation of neutrophil extracellular traps (NETs). NETs, increased in RA, are a source of citrullinated autoantigens in RA and induce fibroblast interleukin-8 production. This knowledge is likely to have therapeutic implications, as there is a need of matching therapy with patient profile. Abatacept, a T cell activation modulator, is the best therapy for ACPA(+) RA patients, although clinical data are sparse at present. Rituximab, a monoclonal antibody that depletes B cells, is also the best therapy for ACPA(+) RA patients, and clinical data support this view. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. IgG reactivity against citrullinated myelin basic protein in multiple sclerosis.

    PubMed

    de Seze, J; Dubucquoi, S; Lefranc, D; Virecoulon, F; Nuez, I; Dutoit, V; Vermersch, P; Prin, L

    2001-07-02

    An increased level of citrullinated myelin basic protein (MBP-C8) has been reported in the brains of multiple sclerosis (MS) patients. However, the involvement of the immune response to post-translational modified MBP in the pathophysiology of MS remains speculative. The aim of this study was to compare the levels of immunoglobulin G antibodies to several MBP epitopes, before and after citrullination, in the cerebrospinal fluid (CSF) and sera of MS patients using enzyme-linked immunosorbent assay (ELISA). We analyzed antibody reactivity against various MBP-peptides in the CSF and sera of 60 MS patients, and 30 patients with other neurological diseases (OND) as controls. The peptides tested were: MBP(75-98) (peptide 1), native (peptide 2) and citrullinated (peptide 3) MBP(108-126) (ARG(122)-->Cit(122)), and native (peptide 4) and citrullinated (peptide 5) MBP(151-170) (ARG(159, 170)-->Cit(159, 170)). All selected peptides could support an immune reactivity in CSF and sera of MS and OND patients. A higher reactivity against peptide 4 was found in the CSF of MS patients compared with OND patients (P<0.0001), but not against citrullinated peptides (peptides 3 and 5). However, we observed that the citrullination state of peptide 2 modified the patterns of immune reactivity more markedly in MS patients (P<0.0001) than in OND patients (P<0.02). Although some MBP epitopes could be a potential target in MS, our data did not demonstrate any difference of antibody response to MBP peptides in their citrullinated forms.

  2. T-cell autoreactivity to citrullinated autoantigenic peptides in rheumatoid arthritis patients carrying HLA-DRB1 shared epitope alleles

    PubMed Central

    2012-01-01

    Introduction Anti-citrullinated peptide antibodies are found in rheumatoid arthritis (RA) patients with HLA-DRβ chains encoding the shared epitope (SE) sequence. Citrullination increases self-antigen immunogenicity, through increased binding affinity to SE-containing HLA-DR molecules. To characterise T-cell autoreactivity towards citrullinated self-epitopes, we profiled responses of SE+ healthy controls and RA patients to citrullinated and unmodified epitopes of four autoantigens. Methods We compared T-cell proliferative and cytokine responses to citrullinated and native type II collagen 1,237 to 1,249, vimentin 66 to 78, aggrecan 84 to 103 and fibrinogen 79 to 91 in six SE+ healthy controls and in 21 RA patients with varying disease duration. Cytokine-producing cells were stained after incubation with peptide in the presence of Brefeldin-A. Results Although proliferative responses were low, IL-6, IL-17 and TNF were secreted by CD4+ T cells of SE+ RA patients and healthy controls, as well as IFNγ and IL-10 secreted by RA patients, in response to citrullinated peptides. Of the epitopes tested, citrullinated aggrecan was most immunogenic. Patients with early RA were more likely to produce IL-6 in response to no epitope or to citrullinated aggrecan, while patients with longstanding RA were more likely to produce IL-6 to more than one epitope. Cytokine-producing CD4+ T cells included the CD45RO+ and CD45RO- and the CD28+ and CD28- subsets in RA patients. Conclusion Proinflammatory cytokines were produced by CD4+ T cells in SE+ individuals in response to citrullinated self-epitopes, of which citrullinated aggrecan was most immunogenic. Our data suggest that the T-cell response to citrullinated self-epitopes matures and diversifies with development of RA. PMID:22594821

  3. Anti-citrullinated protein antibodies promote apoptosis of mature human Saos-2 osteoblasts via cell-surface binding to citrullinated heat shock protein 60.

    PubMed

    Lu, Ming-Chi; Yu, Chia-Li; Yu, Hui-Chun; Huang, Hsien-Bin; Koo, Malcolm; Lai, Ning-Sheng

    2016-01-01

    We hypothesized that anti-citrullinated protein antibodies (ACPAs) react with osteoblast surface citrullinated proteins and affect cell function, leading to joint damage in patients with rheumatoid arthritis (RA). First, we purified ACPAs by cyclic citrullinated peptide (CCP)-conjugated affinity column chromatography. The cognate antigens of ACPAs on Saos-2 cells, a sarcoma osteogenic cell line generated from human osteoblasts, were probed by ACPAs, and the reactive bands were analyzed using proteomic analyses. We found that ACPAs bind to Saos-2 cell membrane, and several protein candidates, including HSP60, were identified. We then cloned and purified recombinant heat shock protein 60 (HSP60) and citrullinated HSP60 (citHSP60) and investigated the effect of ACPAs on Saos-2 cell. We confirmed that HSP60 obtained from Saos-2 cell membrane were citrullinated and reacted with ACPAs, which induces Saos-2 cells apoptosis via binding to surface-expressed citHSP60 through Toll-like receptor 4 signaling. ACPAs promoted interleukin (IL)-6 and IL-8 expression in Saos-2 cells. Finally, sera from patients with RA and healthy controls were examined for their titers of anti-HSP60 and anti-citHSP60 antibodies using an enzyme-linked immunosorbent assay. The radiographic change in patients with RA was evaluated using the Genant-modified Sharp scoring system. Patients with RA showed higher sera titers of anti-citHSP60, but not anti-HSP60, antibodies when compared with controls. In addition, the anti-citHSP60 level was positively associated with increased joint damage in patients with RA. In conclusion, Saos-2 cell apoptosis was mediated by ACPAs via binding to cell surface-expressed citHSP60 and the titer of anti-citHSP60 in patients with RA positively associated with joint damage. Copyright © 2015 Elsevier GmbH. All rights reserved.

  4. [Citrulline and arginine kinetics and its value as a prognostic factor in pediatric critically ill patients].

    PubMed

    Blasco-Alonso, J; SánchezYáñez, P; Rosa Camacho, V; Camacho Alonso, J M; Yahyaoui Macías, R; Gil-Gómez, R; Milano Manso, G

    2015-10-01

    Low concentrations of plasma citrulline and arginine have been reported in children under various pathological conditions. Plasma citrulline and arginine levels undergo different kinetics during the early days of critical illness in children according to the severity of symptoms and can be correlated with other clinical and laboratory parameters associated with the SIR. A single-center prospective observational study in patients 7 days to 14 years admitted to pediatric intensive care unit (PICU). Citrulline and arginine blood levels (blood in dry paper, analysis by mass spectrometry in tandem), acute phase reactants and clinical data were collected on admission, at 12 h, 24 h, 3 and 7 days. A total of 44 critically ill patients were included and control group was formed by 42 healthy children. The citrulline and arginine kinetic analysis showed: 1) Citrulline falls significantly (P<.05) at 12 h of admission; levels remain low until day 7 and begin progressive increase again. 2) Arginine is already lowered at 6h, although an earlier rise occurs (3rd day). 3. The decrease of citrulline in the first 3 days of admission positively correlates with arginine kinetics. Bivariate analysis showed: 1) Correlation of elevated citrulline on the 7th day with shorter duration of mechanical ventilation, lower PICU stay and lower occurrence of complications. The levels of citrulline still descended at day 7 are associated with increased CRP/procalcitonin elevation at first 24 h. 2) The greatest decrease of arginine in the first 12 h is associated with a longer PICU stay and greater number of complications and increase of acute phase reactants at 3 days. There are decreased levels of arginine and citrulline in the first days at PICU, with recovery at the 3rd and 7th day respectively, and a relationship between a greater decrease and a worse outcome and between a longer income and a higher serum CRP/procalcitonin. Copyright © 2015. Published by Elsevier España, S.L.U.

  5. Co-application of canavanine and irradiation uncouples anticancer potential of arginine deprivation from citrulline availability

    PubMed Central

    Kurlishchuk, Yuliya; Vynnytska-Myronovska, Bozhena; Grosse-Gehling, Philipp; Bobak, Yaroslav; Manig, Friederike; Chen, Oleg; Merker, Sebastian R.; Henle, Thomas; Löck, Steffen; Stange, Daniel E.; Stasyk, Oleh; Kunz, Leoni A.

    2016-01-01

    The moderate anticancer effect of arginine deprivation in clinical trials has been linked to an induced argininosuccinate synthetase (ASS1) expression in initially ASS1-negative tumors, and ASS1-positive cancers are anticipated as non-responders. Our previous studies indicated that arginine deprivation and low doses of the natural arginine analog canavanine can enhance radioresponse. However, the efficacy of the proposed combination in the presence of extracellular citrulline, the substrate for arginine synthesis by ASS1, remains to be elucidated, in particular for malignant cells with positive and/or inducible ASS1 as in colorectal cancer (CRC). Here, the physiological citrulline concentration of 0.05 mM was insufficient to overcome cell cycle arrest and radiosensitization triggered by arginine deficiency. Hyperphysiological citrulline (0.4 mM) did not entirely compensate for the absence of arginine and significantly decelerated cell cycling. Similar levels of canavanine-induced apoptosis were detected in the absence of arginine regardless of citrulline supplementation both in 2-D and advanced 3-D assays, while normal colon epithelial cells in organoid/colonosphere culture were unaffected. Notably, canavanine tremendously enhanced radiosensitivity of arginine-starved 3-D CRC spheroids even in the presence of hyperphysiological citrulline. We conclude that the novel combinatorial targeting strategy of metabolic-chemo-radiotherapy has great potential for the treatment of malignancies with inducible ASS1 expression. PMID:27689335

  6. Monoclonal L-citrulline immunostaining reveals nitric oxide-producing vestibular neurons

    NASA Technical Reports Server (NTRS)

    Holstein, G. R.; Friedrich, V. L. Jr; Martinelli, G. P.

    2001-01-01

    Nitric oxide is an unstable free radical that serves as a novel messenger molecule in the central nervous system (CNS). In order to understand the interplay between classic and novel chemical communication systems in vestibular pathways, the staining obtained using a monoclonal antibody directed against L-citrulline was compared with the labeling observed using more traditional markers for the presence of nitric oxide. Brainstem tissue from adult rats was processed for immunocytochemistry employing a monoclonal antibody directed against L-citrulline, a polyclonal antiserum against neuronal nitric oxide synthase, and/or NADPH-diaphorase histochemistry. Our findings demonstrate that L-citrulline can be fixed in situ by vascular perfusion, and can be visualized in fixed CNS tissue sections by immunocytochemistry. Further, the same vestibular regions and cell types are labeled by NADPH-diaphorase histochemistry, by the neuronal nitric oxide synthase antiserum, and by our anti-L-citrulline antibody. Clusters of L-citrulline-immunoreactive neurons are present in subregions of the vestibular nuclei, including the caudal portion of the inferior vestibular nucleus, the magnocellular portion of the medial vestibular nucleus, and the large cells in the ventral tier of the lateral vestibular nucleus. NADPH-diaphorase histochemical staining of these neurons clearly demonstrated their multipolar, fusiform and globular somata and long varicose dendritic processes. These results provide support for the suggestion that nitric oxide serves key roles in both vestibulo-autonomic and vestibulo-spinal pathways.

  7. Monoclonal L-citrulline immunostaining reveals nitric oxide-producing vestibular neurons

    NASA Technical Reports Server (NTRS)

    Holstein, G. R.; Friedrich, V. L. Jr; Martinelli, G. P.

    2001-01-01

    Nitric oxide is an unstable free radical that serves as a novel messenger molecule in the central nervous system (CNS). In order to understand the interplay between classic and novel chemical communication systems in vestibular pathways, the staining obtained using a monoclonal antibody directed against L-citrulline was compared with the labeling observed using more traditional markers for the presence of nitric oxide. Brainstem tissue from adult rats was processed for immunocytochemistry employing a monoclonal antibody directed against L-citrulline, a polyclonal antiserum against neuronal nitric oxide synthase, and/or NADPH-diaphorase histochemistry. Our findings demonstrate that L-citrulline can be fixed in situ by vascular perfusion, and can be visualized in fixed CNS tissue sections by immunocytochemistry. Further, the same vestibular regions and cell types are labeled by NADPH-diaphorase histochemistry, by the neuronal nitric oxide synthase antiserum, and by our anti-L-citrulline antibody. Clusters of L-citrulline-immunoreactive neurons are present in subregions of the vestibular nuclei, including the caudal portion of the inferior vestibular nucleus, the magnocellular portion of the medial vestibular nucleus, and the large cells in the ventral tier of the lateral vestibular nucleus. NADPH-diaphorase histochemical staining of these neurons clearly demonstrated their multipolar, fusiform and globular somata and long varicose dendritic processes. These results provide support for the suggestion that nitric oxide serves key roles in both vestibulo-autonomic and vestibulo-spinal pathways.

  8. Dual Immunofluorescence Study of Citrullinated Proteins in Alzheimer Diseased Frontal Cortex

    PubMed Central

    Nicholas, Anthony P.

    2013-01-01

    Deimination is a post-translational modification of proteins in which selected arginine amino acids are enzymatically converted to citrullines. Using dual-color immunofluorescence, the present study is the first to examine the frontal cortex of patients with Alzheimer's disease (AD) versus age-matched controls with an established monoclonal antibody (F95) against peptidyl-citrulline moieties. In AD specimens, a number of new findings were discovered, including evidence for deiminated proteins in extracellular plaques, the walls of large blood vessels, the nuclei of selective neurons immunoreactive for phosphorylated tau and numerous reactive astrocytes concentrated around extracellular plaques, ventricular surfaces and at the interface between the gray and white matter of the cortex. Although the identities of these citrullinated proteins remain largely unknown, the present study adds to the growing number of locations in which deiminated proteins may be found in the brains of patients with AD. PMID:23648390

  9. Dual immunofluorescence study of citrullinated proteins in Alzheimer diseased frontal cortex.

    PubMed

    Nicholas, Anthony P

    2013-06-17

    Deimination is a post-translational modification of proteins in which selected arginine amino acids are enzymatically converted to citrullines. Using dual-color immunofluorescence, the present study is the first to examine the frontal cortex of patients with Alzheimer's disease (AD) versus age-matched controls with an established monoclonal antibody (F95) against peptidyl-citrulline moieties. In AD specimens, a number of new findings were discovered, including evidence for deiminated proteins in extracellular plaques, the walls of large blood vessels, the nuclei of selective neurons immunoreactive for phosphorylated tau and numerous reactive astrocytes concentrated around extracellular plaques, ventricular surfaces and at the interface between the gray and white matter of the cortex. Although the identities of these citrullinated proteins remain largely unknown, the present study adds to the growing number of locations in which deiminated proteins may be found in the brains of patients with AD. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Contribution of citrulline to the formation of ethyl carbamate during Chinese rice wine production.

    PubMed

    Wang, Peihong; Sun, Junyong; Li, Xiaomin; Wu, Dianhui; Li, Tong; Lu, Jian; Chen, Jian; Xie, Guangfa

    2014-04-01

    Ethyl carbamate is a well-known carcinogen and widely occurs in Chinese rice wine. To provide more clues to minimise ethyl carbamate accumulation, the levels of possible precursors of ethyl carbamate in Chinese rice wine were investigated by HPLC. Studies of the possible precursors of ethyl carbamate in Chinese raw rice wine with various additives and treatments indicated that significant amounts of urea can account for ethyl carbamate formation. It was also recognised that citrulline is another important precursor that significantly affects ethyl carbamate production during the boiling procedure used in the Chinese rice wine manufacturing process. Besides urea and citrulline, arginine was also found to be an indirect ethyl carbamate precursor due to its ability to form urea and citrulline by microorganism metabolism.

  11. Fine specificity of anti-citrullinated peptide antibodies discloses a heterogeneous antibody population in rheumatoid arthritis

    PubMed Central

    Goules, J D; Goules, A V; Tzioufas, A G

    2013-01-01

    Anti-citrullinated peptide antibodies (ACPA) are highly specific for rheumatoid arthritis (RA). However, the predominant B cell epitopes have not yet been defined. The aim of this study was to examine the reactivity of ACPA against different peptides derived from citrullinated proteins and to investigate whether or not these antibodies constitute a homogeneous population. For this purpose, sera from patients with RA (n = 141), systemic lupus erythematosus (SLE) (n = 60), Sjögren's syndrome (SS) (n = 54) and healthy controls (n = 100) were tested for their reactivity against six citrullinated peptides derived from peptidyl arginine deiminase (PAD), vimentin (vim), alpha-enolase (enol), fibrin, type II collagen (col-II) and filaggrin, respectively. A non-citrullinated control peptide derived from PAD was used as control (ctrlPAD621–40). Antibody reactivity against each individual peptide was evaluated by enzyme-linked immunosorbent assay (ELISA). Specificity and cross-reactivity of ACPA were tested by using two prototype sera with homologous and cross-inhibition assays. Specificity of ACPA from two prototype sera was confirmed by purification of anti-peptide antibodies and homologous-inhibition experiments. We found that sera from patients with RA reacted diversely with the six citrullinated peptides. More specifically, PAD211–30 displayed 29·08% sensitivity, vim60–75 29·08%, enol5–21 37·59%, fibrin617–31 31·21%, col-II358–75 29·97% and filaggrin306–24 28·37%, while control ctrlPAD621–40 showed no reactivity. All reactive peptides were found to be highly specific for RA. A notable cross-reaction (>70%) was found mainly between filaggrin and the majority of anti-citrullinated peptide antibodies. We concluded that ACPA in RA constitute a heterogeneous population with limited cross-reactivity and without a predominant epitope. PMID:23711220

  12. Plasma l-citrulline concentrations in l-arginine-supplemented healthy dogs.

    PubMed

    Flynn, K M; Kellihan, H B; Trepanier, L A

    2017-08-01

    To determine whether oral l-arginine increases plasma [l-citrulline] in dogs. Eleven healthy staff-owned dogs were used in this study. Dogs (n = 3) were given l-arginine (50mg/kg PO q8h) for 7 days, and plasma [l-arginine] and [l-citrulline] were analyzed by high performance liquid chromatography at baseline (BL), steady state trough, and 0.5, 1, 1.5, 2, 4, 6, and 8 h after final dosing on day 7. Eleven dogs were then treated with 100mg/kg l-arginine PO q8h for 7 days, and [l-arginine] and [l-citrulline] were measured at BL, steady state trough, and at peak 4 hrs after dosing (T4 hrs). - Plasma [l-arginine] and [l-citrulline] peaked at T4 hrs on the 50mg/kg dosage. Target outcome, modeled after human study results, of a doubling of [l-arginine] and a 25-30% increase in [l-citrulline] from BL were not reached. After the 100mg/kg dosage, plasma [l-arginine] increased from a BL median of 160.1 μM (range, 100.2-231.4 μM) to a peak of 417.4 μM (206.5-807.3 μM) at T4 hrs, and plasma [l-citrulline] increased from a BL median of 87.8 μM (59.1-117.1 μM) to peak of 102.2 μM (47.4-192.6 μM) at T4 hrs. Ten of eleven dogs showed a doubling of plasma [l-arginine] and 4/11 dogs achieved 25-30% or greater increases in plasma [l-citrulline]. No adverse effects on heart rate or blood pressure were noted. - Oral l-arginine dosage of 100mg/kg q8h doubles plasma [l-arginine] in healthy dogs, but conversion to l-citrulline is quite variable. Further evaluation of this dosage regimen in dogs with pulmonary hypertension is warranted. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Validation of a multiplex chip-based assay for the detection of autoantibodies against citrullinated peptides

    PubMed Central

    2012-01-01

    Introduction Autoantibodies directed against citrullinated proteins/peptides (ACPAs) are highly specific and predictive for the development of rheumatoid arthritis (RA). Different subgroups of RA patients, which have different prognoses and may require different treatments, are characterized by different autoantibody profiles. The objective of this study was to develop a microarray for the detection of multiple RA-associated autoantibodies, initially focusing on responses against citrullinated epitopes on candidate autoantigens in RA. Methods The microarray is based on Phadia's ImmunoCAP ISAC system, with which reactivity to more than 100 antigens can be analyzed simultaneously, by using minute serum volumes (< 10 μl). Twelve citrullinated peptides, and the corresponding native arginine-containing control peptides, were immobilized in an arrayed fashion onto a chemically modified glass slide, allowing a three-dimensional layer with high binding capacity. The assay was optimized concerning serum dilution and glass surface, whereas each individual antigen was optimized concerning coupling chemistry, antigen concentration, and selection of spotting buffer. The performance of each peptide in the ImmunoCAP ISAC system was compared with the performance in enzyme-linked immunosorbent assays (ELISAs). Serum from 927 RA patients and 461 healthy controls from a matched case-control study were applied onto reaction sites on glass slides, followed by fluorescent-labeled anti-human immunoglobulin G (IgG) antibody. Fluorescence intensities were detected with a laser scanner, and the results analyzed by using image-analysis software. Results Strong correlations between the ImmunoCAP ISAC system and ELISA results were found for individual citrullinated peptides (Spearman ρ typically between 0.75 and 0.90). Reactivity of RA sera with the peptides was seen mainly in the anticyclic citrullinated peptide 2 (CCP2)-positive subset, but some additional reactivity with single

  14. In-Depth Analysis of Citrulline Specific CD4 T-Cells in Rheumatoid Arthritis

    DTIC Science & Technology

    2017-01-01

    AWARD NUMBER: W81XWH-15-1-0004 TITLE: In-Depth Analysis of Citrulline-Specific CD4 T-Cells in Rheumatoid Arthritis PRINCIPAL INVESTIGATOR...2016 4. TITLE AND SUBTITLE In-Depth Analysis of Citrulline-Specific CD4 T Cells in Rheumatoid Arthritis 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH...NOTES 14. ABSTRACT The goal of this project is to test the hypothesis that cit-specific CD4 T cells present in rheumatoid arthritis (RA) patients

  15. In Depth Analysis of Citrulline Specific CD4 T Cells in Rheumatoid Arthritis

    DTIC Science & Technology

    2017-01-01

    AWARD NUMBER: W81XWH-15-1-0003 TITLE: In-Depth Analysis of Citrulline-Specific CD4 T Cells in Rheumatoid Arthritis PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE In-Depth Analysis of Citrulline-Specific CD4 T Cells in Rheumatoid Arthritis 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0003...NOTES 14. ABSTRACT The goal of this project is to test the hypothesis that cit-specific CD4 T cells present in rheumatoid arthritis (RA) patients

  16. Peptidylarginine deiminase 1-catalyzed histone citrullination is essential for early embryo development

    PubMed Central

    Zhang, Xiaoqian; Liu, Xiaoqiu; Zhang, Mei; Li, Tingting; Muth, Aaron; Thompson, Paul R.; Coonrod, Scott A.; Zhang, Xuesen

    2016-01-01

    Peptidylarginine deiminase (PADI) enzymes are increasingly being associated with the regulation of chromatin structure and gene activity via histone citrullination. As one of the PADI family members, PADI1 has been mainly reported to be expressed in the epidermis and uterus, where the protein in keratinocytes is thought to promote differentiation by citrullinating filament proteins. However, the roles of PADI1 in preimplantation development have not been addressed. Using a PADI1-specific inhibitor and Padi1-morpholino knockdown, we found that citrullination of histone tails at H4R3 and H3R2/8/17 were markedly reduced in the 2- and 4-cell embryos. Consistent with this observation, early embryo development was also arrested at the 4-cell stage upon depletion of PADI1 or inhibition of PADI1 enzyme activity. Additionally, by employing 5-ethynyl uridine (EU) incorporation analysis, ablation of PADI1 function led to a dramatic decrease in overall transcriptional activity, correlating well with the reduced levels of phosphorylation of RNA Pol II at Ser2 observed at 2- or 4-cell stage of embryos under Padi1 knockdown or inhibiting PADI1. Thus, our data reveal a novel function of PADI1 during early embryo development transitions by catalyzing histone tail citrullination, which facilitates early embryo genome transactivation. PMID:27929094

  17. Current Challenges and Limitations in Antibody-Based Detection of Citrullinated Histones

    PubMed Central

    Neeli, Indira; Radic, Marko

    2016-01-01

    Studies on NETosis demand reliable and convenient markers to monitor the progress of this form of cell death. Because a determining step in the release of nuclear chromatin NETs requires the conversion of arginine residues to citrulline residues in histones by peptidylarginine deiminase, citrullinated histones can provide such a marker. Here, we evaluate antibody reagents for the detection of citrulline residues in histones and observe alarming differences between commercial antisera and mouse and rabbit monoclonal antibodies in their ability to detect their nominal target residues. Differences between antibodies that are currently used to detect citrulline residues in histones could jeopardize efforts to reach a scientific consensus and instead lead to inconsistent and even conflicting conclusions regarding the regulation of histone deimination. Our results will assist others in planning their initial or ongoing studies on peptidylarginine deiminase activity with the use of currently available antibodies. Furthermore, we argue that, along with the careful attention to experimental conditions and calcium concentrations, validated antibody reagents are urgently needed to avoid possible setbacks in the research on NETosis. PMID:27933065

  18. NETs are a source of citrullinated autoantigens and stimulate inflammatory responses in rheumatoid arthritis

    PubMed Central

    Khandpur, Ritika; Carmona-Rivera, Carmelo; Vivekanandan-Giri, Anuradha; Gizinski, Alison; Yalavarthi, Srilakshmi; Knight, Jason S.; Friday, Sean; Li, Sam; Patel, Rajiv M.; Subramanian, Venkataraman; Thompson, Paul; Chen, Pojen; Fox, David A.; Pennathur, Subramaniam; Kaplan, Mariana J.

    2013-01-01

    The early events leading to the development of rheumatoid arthritis (RA) remain unclear but formation of autoantibodies to citrullinated antigens (ACPA) is considered a key pathogenic phenomenon. Neutrophils isolated from patients with various autoimmune diseases display enhanced extracellular trap formation (NETs), a phenomenon that externalizes autoantigens and immunostimulatory molecules. We investigated whether aberrant NETosis occurs in RA, determined its triggers and examined its deleterious inflammatory consequences. Enhanced NETosis was observed in circulating and synovial fluid RA neutrophils, compared to neutrophils from healthy controls and from patients with osteoarthritis. Further, netting neutrophils infiltrated RA synovial tissue, rheumatoid nodules and skin. NETosis correlated with ACPA presence and levels and with systemic inflammatory markers. RA sera and immunoglobulin fractions from RA patients with high levels of ACPA and/or rheumatoid factor significantly enhanced NETosis, and the NETs induced by these autoantibodies displayed distinct protein content. During NETosis, neutrophils externalized citrullinated autoantigens implicated in RA pathogenesis, whereas anti-citrullinated vimentin antibodies potently induced NET formation. The inflammatory cytokines IL-17A and TNF-α induced NETosis in RA neutrophils. In turn, NETs significantly augmented inflammatory responses in RA and OA synovial fibroblasts, including induction of IL-6, IL-8, chemokines and adhesion molecules. These observations implicate accelerated NETosis in RA pathogenesis, through externalization of citrullinated autoantigens and immunostimulatory molecules that may promote aberrant adaptive and innate immune responses in the joint and in the periphery, and perpetuate pathogenic mechanisms in this disease. PMID:23536012

  19. Purification and characterization of glutamate N-acetyltransferase involved in citrulline accumulation in wild watermelon.

    PubMed

    Takahara, Kentaro; Akashi, Kinya; Yokota, Akiho

    2005-10-01

    Citrulline is an efficient hydroxyl radical scavenger that can accumulate at concentrations of up to 30 mm in the leaves of wild watermelon during drought in the presence of strong light; however, the mechanism of this accumulation remains unclear. In this study, we characterized wild watermelon glutamate N-acetyltransferase (CLGAT) that catalyses the transacetylation reaction between acetylornithine and glutamate to form acetylglutamate and ornithine, thereby functioning in the first and fifth steps in citrulline biosynthesis. CLGAT enzyme purified 7000-fold from leaves was composed of two subunits with different N-terminal amino acid sequences. Analysis of the corresponding cDNA revealed that these two subunits have molecular masses of 21.3 and 23.5 kDa and are derived from a single precursor polypeptide, suggesting that the CLGAT precursor is cleaved autocatalytically at the conserved ATML motif, as in other glutamate N-acetyltransferases of microorganisms. A green fluorescence protein assay revealed that the first 26-amino acid sequence at the N-terminus of the precursor functions as a chloroplast transit peptide. The CLGAT exhibited thermostability up to 70 degrees C, suggesting an increase in enzyme activity under high leaf temperature conditions during drought/strong-light stresses. Moreover, CLGAT was not inhibited by citrulline or arginine at physiologically relevant high concentrations. These findings suggest that CLGAT can effectively participate in the biosynthesis of citrulline in wild watermelon leaves during drought/strong-light stress.

  20. Arginine and ornithine are the main precursors for citrulline synthesis in mice

    USDA-ARS?s Scientific Manuscript database

    Recent isotopic tracer studies in mice, piglets, and humans have produced conflicting results as to the main carbon skeleton precursor for citrulline and arginine synthesis. This may be due in part to the different tracers infused and models utilized to interpret the stable isotope data. Furthermore...

  1. Glutamine supplementation, citrulline production, and de novo arginine synthesis: Is there a relation?

    USDA-ARS?s Scientific Manuscript database

    We would like to comment on the recent publications by Buijs et al. The authors hypothesized that a parenteral supplement of glutamine stimulates citrulline formation and enhances de novo arginine synthesis. To test this hypothesis, they conducted an experiment with stable isotopes in patients under...

  2. Precursors for the synthesis of citrulline in mice fed arginine free diets

    USDA-ARS?s Scientific Manuscript database

    Dietary arginine (Arg) is the main dietary precursor for citrulline (Cit) synthesis. To test the hypothesis that the contribution of dietary proline (Pro) and glutamine (Gln) increases during the feeding of an Arg free diet, rates of appearance (Ra) and precursor-intermediate-product relationships w...

  3. Quantification of L-Citrulline and other physiologic amino acids in watermelon and selected cucurbits

    USDA-ARS?s Scientific Manuscript database

    High performance liquid chromatography of dabsyl derivatives of amino acids was employed for quantification of physiologic amino acids in cucurbits. This method is particularly useful because the dabsyl derivatives of glutamine and citrulline are sufficiently separated to allow quantification of ea...

  4. Post-translational modifications in rheumatoid arthritis and atherosclerosis: Focus on citrullination and carbamylation.

    PubMed

    Spinelli, Francesca Romana; Pecani, Arbi; Conti, Fabrizio; Mancini, Riccardo; Alessandri, Cristiano; Valesini, Guido

    2016-09-01

    Coronary heart disease is the main cause of mortality in patients with rheumatoid arthritis (RA), a disease known to be associated with accelerated atherosclerosis. The role of inflammation and immunity in atherosclerotic process offers possible explanations for the increased cardiovascular risk in patients with RA. The immune response to citrullinated peptides has been extensively studied in RA; antibodies directed to citrullinated peptides are now a cornerstone for RA diagnosis. However, few studies have investigated the response to citrullinated peptides and the development of atherosclerotic plaque. Antibodies to carbamylated proteins can be detected before the clinical onset of RA, suggesting a potential predictive role for these antibodies; on the other hand, carbamylation of lipoproteins has been described in patients with cardiovascular disease. This review examines the role of citrullination and carbamylation, two post-translational protein modifications that appear to be involved in the pathogenesis of both RA and atherosclerosis, expanding the similarities between these two diseases. Further investigation on the role of the immune response to modified proteins may contribute to a better comprehension of cardiovascular disease in patients with RA.

  5. L-citrulline levels in watermelon cultigens tested in two environments

    USDA-ARS?s Scientific Manuscript database

    Melon producers face increasing production costs and international market competition. Maximizing marketability of high quality watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai], that also contain high levels of the amino acid phytonutrient L-citrulline, can provide new market niches for th...

  6. Nitric oxide production by peritoneal macrophages from aged rats: A short term and direct modulation by citrulline.

    PubMed

    Breuillard, Charlotte; Curis, Emmanuel; Le Plénier, Servane; Cynober, Luc; Moinard, Christophe

    2017-02-01

    Citrulline has anti-inflammatory properties and exerts beneficial effects on various impaired functions in aging. However, there are few data on citrulline action on immune function in aged populations. The objective of the study was to evaluate citrulline ability, after in vivo and in vitro administration, to modulate macrophage functions in aged rats and the possible pathways involved. Twenty-one-month-old Sprague-Dawley rats (n = 27) received a citrulline supplementation at 5 g/kg/d for 5 days, or an isonitrogenous diet, and peritoneal macrophages were cultured with or without LPS. In the in vitro study, macrophages from 22-month-old rats (n = 16) were cultured with or without LPS, citrulline and inhibitors of different inflammatory pathways (n = 8/conditions). Nitric oxide (NO) and tumor necrosis factor α (TNFα) production were measured in both in vivo and in vitro studies. Citrulline decreased NO production variability by peritoneal macrophages after in vivo administration (p = 0.0034) and downregulated NO production by 22% after in vitro administration (95% CI: [6%; 35%]; p = 0.0394), without any direct effect on TNFα production. None of the transductional pathways explored seem to be involved. Citrulline slightly modulates NO production in vivo and in vitro, suggesting a possible action through modulation of arginine metabolism in macrophages rather than a direct transductional effect. The pleiotropic effects of citrulline in aging could be due, at least in part, to the anti-inflammatory effect of citrulline. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  7. Citrullination of CXCL8 increases this chemokine’s ability to mobilize neutrophils into the blood circulation

    PubMed Central

    Loos, Tamara; Opdenakker, Ghislain; Van Damme, Jo; Proost, Paul

    2009-01-01

    Background During the first line defense of an infected host, circulating neutrophils invade the inflamed tissue, whereas mature neutrophils from the bone marrow pool migrate into the blood circulation and from there reinforce tissue infiltration. The CXC chemokine CXCL8, also know as interleukin-8, is a potent attractant of neutrophils. Recently, we discovered a new natural post-translational modification of CXCL8, i.e. the deimination of arginine into citrulline by peptidylarginine deiminases. Design and Methods The ability to provoke leukocytosis was assessed by intravenous administration of citrullinated CXCL8 in rabbits. Adsorption of citrullinated CXCL8 to the Duffy antigen/receptor for chemokines on human or rabbit erythrocytes was evaluated using a competitive binding assay. Finally, surface expression of adhesion molecules was studied after stimulating neutrophils with citrullinated CXCL8. Results Citrullination of CXCL8 significantly increased this chemokine’s ability to recruit neutrophils into the blood circulation. In addition, the competitive binding properties of CXCL8 for the Duffy antigen/receptor for chemokines were impaired upon citrullination. Since the Duffy antigen/receptor for chemokines is an important scavenging receptor for CXCL8 in the blood stream, citrullination may delay CXCL8 clearance from the circulation. Furthermore, the shedding of CD62L (L-selectin) and the upregulation of CD11b (β2-integrin) protein expression on CXCL8-induced neutrophils were improved by deimination of CXCL8, possibly contributing to the neutrophil egress from the bone marrow. Conversely, surface expression of CD15, the neutrophilic ligand of endothelial selectins, was equally well upregulated by intact and citrullinated CXCL8. Conclusions These data show that citrullination of CXCL8 enhances leukocytosis, possibly through impaired chemokine clearance from the blood circulation and prolonged presentation to the bone marrow. PMID:19608678

  8. Comparative analysis of autoantibodies targeting peptidylarginine deiminase type 4, mutated citrullinated vimentin and cyclic citrullinated peptides in rheumatoid arthritis: associations with cytokine profiles, clinical and genetic features.

    PubMed

    Reyes-Castillo, Z; Palafox-Sánchez, C A; Parra-Rojas, I; Martínez-Bonilla, G E; del Toro-Arreola, S; Ramírez-Dueñas, M G; Ocampo-Bermudes, G; Muñoz-Valle, José F

    2015-11-01

    Antibodies against cyclic citrullinated peptides (anti-CCP) are widely used for diagnosis of rheumatoid arthritis (RA). We performed a comparative analysis of antibodies targeting the citrullinating enzyme peptidylarginine deiminase type 4 (anti-PAD4) and mutated citrullinated vimentin (anti-MCV) with anti-CCP autoantibodies in RA patients and examined their relationships with clinical parameters, cytokine profiles and the PADI4 gene. Autoantibodies were examined by enzyme-linked immunosorbent assay (ELISA) in sera of 170 RA patients and 103 controls. Cytokine profiles were measured using a multiplex system. PADI4 polymorphisms (89 G > A, 90 T > C and 92 G > C) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Anti-PAD4, anti-MCV and anti-CCP autoantibodies were detected in 24, 61 and 74% of RA patients, respectively. Positive correlations were observed between anti-PAD4 and disease duration; anti-CCP and erythrocyte sedimentation rate (ESR); anti-MCV and ESR and C-reactive protein. Anti-MCV antibodies were associated with high disease activity score 28 (DAS-28) in early RA. Concentrations of T helper type 1 (Th1) [tumour necrosis factor (TNF)-α, interleukin (IL)-12, IL-2, IL-1β], Th2 (IL-4, IL-6, IL-10, IL-13) and Th17 (IL-17) cytokines were higher in RA than in controls. Th2 and, to a lesser extent, Th1-related cytokines, showed positive correlations with anti-MCV and anti-CCP. The GTG haplotype in PADI4 was associated with anti-CCP and anti-MCV, but not anti-PAD4 antibodies. In conclusion, anti-PAD4 antibodies are detected mainly in established RA, which is in contrast to the early detection of antibodies against citrullinated peptide/proteins (ACPAs). Among autoantibodies, anti-MCV appear to perform better as markers of disease activity. Furthermore, anti-CCP and anti-MCV are associated genetically with the citrullinating enzyme PAD4 and are related strongly to Th1 and Th2 cytokines, suggesting a feed

  9. Comparative analysis of autoantibodies targeting peptidylarginine deiminase type 4, mutated citrullinated vimentin and cyclic citrullinated peptides in rheumatoid arthritis: associations with cytokine profiles, clinical and genetic features

    PubMed Central

    Reyes-Castillo, Z; Palafox-Sánchez, C A; Parra-Rojas, I; Martínez-Bonilla, G E; del Toro-Arreola, S; Ramírez-Dueñas, M G; Ocampo-Bermudes, G; Muñoz-Valle, José F

    2015-01-01

    Antibodies against cyclic citrullinated peptides (anti-CCP) are widely used for diagnosis of rheumatoid arthritis (RA). We performed a comparative analysis of antibodies targeting the citrullinating enzyme peptidylarginine deiminase type 4 (anti-PAD4) and mutated citrullinated vimentin (anti-MCV) with anti-CCP autoantibodies in RA patients and examined their relationships with clinical parameters, cytokine profiles and the PADI4 gene. Autoantibodies were examined by enzyme-linked immunosorbent assay (ELISA) in sera of 170 RA patients and 103 controls. Cytokine profiles were measured using a multiplex system. PADI4 polymorphisms (89G > A, 90T > C and 92G > C) were genotyped by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). Anti-PAD4, anti-MCV and anti-CCP autoantibodies were detected in 24, 61 and 74% of RA patients, respectively. Positive correlations were observed between anti-PAD4 and disease duration; anti-CCP and erythrocyte sedimentation rate (ESR); anti-MCV and ESR and C-reactive protein. Anti-MCV antibodies were associated with high disease activity score 28 (DAS-28) in early RA. Concentrations of T helper type 1 (Th1) [tumour necrosis factor (TNF)-α, interleukin (IL)-12, IL-2, IL-1β], Th2 (IL-4, IL-6, IL-10, IL-13) and Th17 (IL-17) cytokines were higher in RA than in controls. Th2 and, to a lesser extent, Th1-related cytokines, showed positive correlations with anti-MCV and anti-CCP. The GTG haplotype in PADI4 was associated with anti-CCP and anti-MCV, but not anti-PAD4 antibodies. In conclusion, anti-PAD4 antibodies are detected mainly in established RA, which is in contrast to the early detection of antibodies against citrullinated peptide/proteins (ACPAs). Among autoantibodies, anti-MCV appear to perform better as markers of disease activity. Furthermore, anti-CCP and anti-MCV are associated genetically with the citrullinating enzyme PAD4 and are related strongly to Th1 and Th2 cytokines, suggesting a

  10. Citrullination in Rheumatoid Arthritis—A Process Promoted by Neutrophil Lysis?

    PubMed Central

    Gazitt, Tal; Lood, Christian; Elkon, Keith B.

    2016-01-01

    Anti-citrullinated protein antibodies (ACPAs) are highly specific serologic markers for rheumatoid arthritis (RA) and can pre-date clinical disease onset by up to 10 years, also predicting erosive disease. The process of citrullination, the post-translational conversion of arginine to citrulline residues, is mediated by peptidylarginine deiminase (PAD) enzymes present in polymorphonuclear cells (PMNs). Calcium ions (Ca2+) are required for PAD activation, but the intracellular Ca2+ concentration in normal cells is much lower than the optimal Ca2+ concentration needed for PAD activation. For this reason, it has been proposed that PAD activation, and thus citrullination, occurs only during PMN cell death when PAD enzymes leak out of the cells into the extracellular matrix, or extracellular Ca2+ enters the cells, with the high Ca2+ concentration activating PAD. Recently, using artificial in vitro systems to corroborate their hypothesis, Romero et al. demonstrated that “hypercitrullination,” citrullination of multiple intracellular proteins, occurs within synovial fluid (SF) cells of RA patients, and that only modes of death leading to membranolysis such as perforin-granzyme pathway or complement membrane attack complex activation cause hypercitrullination. In order for Romero’s hypothesis to hold, it is reasonable to surmise that PMN-directed lysis should occur in the rheumatoid joint or the circulation of RA patients. Research conducted thus far has shown that immunoglobulin G (IgG) targeting PMNs are present in RA SF and mediate PMN activation. However, the role of anti-PMN IgG in mediating complement activation and subsequent PMN lysis and hypercitrullination has not been fully evaluated. PMID:27824546

  11. Decreased serum L-arginine and L-citrulline levels in major depression.

    PubMed

    Hess, S; Baker, G; Gyenes, G; Tsuyuki, R; Newman, S; Le Melledo, Jean-Michel

    2017-08-13

    It has been suggested that endothelial dysfunction caused by a decreased endothelial production of nitric oxide (NO) may contribute to the consistently observed increased risk of developing cardiovascular disease (CVD) in physically healthy patients suffering from major depression (MD). NO is a gas synthesized from Larginine (a conditionally essential amino acid) and oxygen by endothelial nitric oxide synthase (eNOS). The end products of NO production include both NO and L-citrulline. NO is rapidly reduced to the anions nitrite and nitrate, classically referred to as NO metabolites. Their measurement has been used as a surrogate measurement for endothelial NO production. We and others have shown decreased levels of NO metabolites in the serum of MD patients. The mechanism of this decreased production of NO by the endothelium has not yet been elucidated. The purpose of this study is to assess serum levels of L-arginine and L-citrulline in patients with MD. Levels of L-arginine and L-citrulline were measured in 35 unmedicated physically healthy MD patients and 36 healthy controls (HCs). L-arginine and L-citrulline concentrations were significantly lower in MD patients than in healthy controls (L-arginine, 73.54 + 21.53 μmol/L and 84.89 + 25.16, p = 0.04 μmol/L and L-citrulline 31.58 + 6.05 μmol/L and 35.19 + 6.85 μmol/L, p = 0.03, respectively). The decrease in L-arginine levels in MD patients is a possible explanation for the decrease in NO metabolites in MD patients and therefore may contribute, through endothelial dysfunction, to the increased CV risk associated with MD.

  12. Contribution of Peptide Backbone to Anti-Citrullinated Peptide Antibody Reactivity

    PubMed Central

    Trier, Nicole Hartwig; Dam, Catharina Essendrup; Olsen, Dorthe Tange; Hansen, Paul Robert; Houen, Gunnar

    2015-01-01

    Rheumatoid arthritis (RA) is one of the most common autoimmune diseases, affecting approximately 1–2% of the world population. One of the characteristic features of RA is the presence of autoantibodies. Especially the highly specific anti-citrullinated peptide antibodies (ACPAs), which have been found in up to 70% of RA patients’ sera, have received much attention. Several citrullinated proteins are associated with RA, suggesting that ACPAs may react with different sequence patterns, separating them from traditional antibodies, whose reactivity usually is specific towards a single target. As ACPAs have been suggested to be involved in the development of RA, knowledge about these antibodies may be crucial. In this study, we examined the influence of peptide backbone for ACPA reactivity in immunoassays. The antibodies were found to be reactive with a central Cit-Gly motif being essential for ACPA reactivity and to be cross-reactive between the selected citrullinated peptides. The remaining amino acids within the citrullinated peptides were found to be of less importance for antibody reactivity. Moreover, these findings indicated that the Cit-Gly motif in combination with peptide backbone is essential for antibody reactivity. Based on these findings it was speculated that any amino acid sequence, which brings the peptide into a properly folded structure for antibody recognition is sufficient for antibody reactivity. These findings are in accordance with the current hypothesis that structural homology rather than sequence homology are favored between citrullinated epitopes. These findings are important in relation to clarifying the etiology of RA and to determine the nature of ACPAs, e.g. why some Cit-Gly-containing sequences are not targeted by ACPAs. PMID:26657009

  13. [The comparative evaluation of the diagnostic value of methods of detection of antibodies to citrullinized proteins under rheumatoid arthritis].

    PubMed

    Novikov, A A; Cherkasova, M V; Aleksandrova, E N; Popkova, T V; Luchikhina, E L; Rytikova, N S; Nasonov, E L

    2012-10-01

    The hyper production of large specter of autoantibodies, primarily rheumatoid factors and antibodies to citrullinized proteins, is a characteristic sign of rheumatoid arthritis. The detection of these antibodies plays an important role in diagnosing the disease, especially on its early stages. The study compared the diagnostic accuracy of different methods of detection of antibodies to citrullinized proteins under rheumatoid arthritis. The examined sample included 144 patients aged 33-58 years with reliable diagnosis of rheumatoid arthritis. The patients with systemic lupus erythematous, osteoarthritis, psoriatic arthritis, OVERLAP syndrome, ankylosing spondylitis and conditionally healthy donors consisted the comparative group. To detect antibodies to citrullinized proteins the methods of enzyme immunoassay, electrochemiluminescence, immunochromatography were applied. The study demonstrated that all the methods of detection of antibodies to citrullinized proteins have adequate diagnostic value to be implemented both in a routine clinical diagnostic practice and on the stage of screening of patients.

  14. Effect of major and minor surgery on plasma levels of arginine, citrulline, nitric oxide metabolites, and ornithine in humans.

    PubMed

    Hol, Jaap W; van Lier, Felix; Valk, Madelous; Klimek, Markus; Stolker, Robert J; Fekkes, Durk

    2013-12-01

    To determine the effect of surgical invasiveness on plasma levels of arginine, citrulline, ornithine, and nitric oxide (NO) in humans. Surgical trauma may have a profound effect on the metabolism of NO. However, human studies reported both increased and decreased NO levels after hemorrhagic shock. Arginine, citrulline, and ornithine are key amino acids involved in NO metabolism, but studies evaluating these amino acids together with NO and during 2 types of surgery are lacking. This study tests the hypothesis that major surgery has a more profound effect on plasma levels of arginine, citrulline, NO, and ornithine than minor surgery. Fifteen patients undergoing minor surgery (vulvectomy) and 13 patients undergoing major surgery (laparotomy) were prospectively followed up for 4 days. Plasma was collected for evaluation of levels of arginine, citrulline, NO, and ornithine. Throughout the experiment, arginine levels did not significantly differ between experimental groups. Perioperative plasma citrulline levels were significantly lower in the laparotomy group than in the vulvectomy group, whereas both groups showed a decrease in citrulline levels at the end of the operation and 24 hours postoperatively. Roughly the same pattern was seen for plasma NO and ornithine levels. However, ornithine levels in the laparotomy group showed a more drastic decrease at the end of the operation and 24 hours postoperatively than citrulline and NO levels. The level of surgical invasiveness has the most profound effect on plasma levels of ornithine. In addition, heavier surgical trauma is paired with lower postoperative levels of citrulline and NO metabolites than lighter surgery. It is suggested that surgical trauma stimulates the laparotomy group to consume significantly more ornithine, possibly for use in wound healing.

  15. Plasma L-citrulline concentrations and its relationship with inflammation at the onset of septic shock: a pilot study.

    PubMed

    Crenn, Pascal; Neveux, Nathalie; Chevret, Sylvie; Jaffray, Patrick; Cynober, Luc; Melchior, Jean-Claude; Annane, Djillali

    2014-04-01

    Hypocitrullinemia has been suggested to be a prognostic factor for patients in intensive care. The aim of this ancillary study of the Corticosteroids and Intensive Insulin Therapy for Septic Shock prospective study was to investigate plasma L-citrulline concentrations and its relationship with inflammation and digestive bacterial translocation in patients with septic shock multiorgan failure and without primary intestinal disease or chronic renal failure. Sixteen adult patients were selected. They were studied on day (D) 0 at hours (H) 0, 6, 12, 18, and 24 and on D4 (H96). Selected plasma amino acids and proteins, proinflammatory (tumor necrosis factor α [TNF-α]) and anti-inflammatory (interleukin [IL] 10) cytokine concentrations, and bacterial translocation were measured. Eight D14 survivors and 8 D14 nonsurvivors patients were studied. Citrulline was decreased on D0 (H0: 29 ± 10 vs nadir: 18 ± 6 μmol/L; P < .05). The citrulline nadir was lower (P < .01) in patients with digestive bacterial translocation than that in those without. Mean citrulline concentrations at H0 to H96 were not significantly different between survivors and nonsurvivors. In both groups, citrulline was significantly inversely correlated with C-reactive protein (r(2) = 0.10, P < .01) on D0. No significant correlations were found between citrulline and albumin, transthyretin, TNF-α, IL-10, or TNF-α/IL-10 ratio. At the onset of septic shock, plasma citrulline decreases and varies inversely with C-reactive protein and is lower when digestive bacterial translocation occurs. This finding could reflect an early acute intestinal dysfunction, but measurement of citrulline concentration does not appear to be able to predict the patients' mortality. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction.

    PubMed

    Cormio, Luigi; De Siati, Mario; Lorusso, Fabrizio; Selvaggio, Oscar; Mirabella, Lucia; Sanguedolce, Francesca; Carrieri, Giuseppe

    2011-01-01

    To test the efficacy and safety of oral L-citrulline supplementation in improving erection hardness in patients with mild erectile dysfunction (ED). L-arginine supplementation improves nitric oxide-mediated vasodilation and endothelial function; however, oral administration has been hampered by extensive presystemic metabolism. In contrast, L-citrulline escapes presystemic metabolism and is converted to L-arginine, thus setting the rationale for oral L-citrulline supplementation as a donor for the L-arginine/nitric oxide pathway of penile erection. In the present single-blind study, men with mild ED (erection hardness score of 3) received a placebo for 1 month and L-citrulline, 1.5 g/d, for another month. The erection hardness score, number of intercourses per month, treatment satisfaction, and adverse events were recorded. A total of 24 patients, mean age 56.5 ± 9.8 years, were entered and concluded the study without adverse events. The improvement in the erection hardness score from 3 (mild ED) to 4 (normal erectile function) occurred in 2 (8.3%) of the 24 men when taking placebo and 12 (50%) of the 24 men when taking L-citrulline (P < .01). The mean number of intercourses per month increased from 1.37 ± 0.93 at baseline to 1.53 ± 1.00 at the end of the placebo phase (P = .57) and 2.3 ± 1.37 at the end of the treatment phase (P < .01). All patients reporting an erection hardness score improvement from 3 to 4 reported being very satisfied. Although less effective than phosphodiesterase type-5 enzyme inhibitors, at least in the short term, L-citrulline supplementation has been proved to be safe and psychologically well accepted by patients. Its role as an alternative treatment for mild to moderate ED, particularly in patients with a psychologically fear of phosphodiesterase type-5 enzyme inhibitors, deserves further research. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Peptidylarginine deiminase 2-catalyzed histone H3 arginine 26 citrullination facilitates estrogen receptor α target gene activation.

    PubMed

    Zhang, Xuesen; Bolt, Michael; Guertin, Michael J; Chen, Wei; Zhang, Sheng; Cherrington, Brian D; Slade, Daniel J; Dreyton, Christina J; Subramanian, Venkataraman; Bicker, Kevin L; Thompson, Paul R; Mancini, Michael A; Lis, John T; Coonrod, Scott A

    2012-08-14

    Cofactors for estrogen receptor α (ERα) can modulate gene activity by posttranslationally modifying histone tails at target promoters. Here, we found that stimulation of ERα-positive cells with 17β-estradiol (E2) promotes global citrullination of histone H3 arginine 26 (H3R26) on chromatin. Additionally, we found that the H3 citrulline 26 (H3Cit26) modification colocalizes with ERα at decondensed chromatin loci surrounding the estrogen-response elements of target promoters. Surprisingly, we also found that citrullination of H3R26 is catalyzed by peptidylarginine deiminase (PAD) 2 and not by PAD4 (which citrullinates H4R3). Further, we showed that PAD2 interacts with ERα after E2 stimulation and that inhibition of either PAD2 or ERα strongly suppresses E2-induced H3R26 citrullination and ERα recruitment at target gene promoters. Collectively, our data suggest that E2 stimulation induces the recruitment of PAD2 to target promoters by ERα, whereby PAD2 then citrullinates H3R26, which leads to local chromatin decondensation and transcriptional activation.

  18. Effects of Oral L-Citrulline Supplementation on Lipoprotein Oxidation and Endothelial Dysfunction in Humans with Vasospastic Angina

    PubMed Central

    Morita, Masahiko; Sakurada, Masami; Watanabe, Fumiko; Yamasaki, Tetsuo; Doi, Hiroshi; Ezaki, Hirotaka; Morishita, Koji; Miyakex, Takayuki

    2013-01-01

    Background: Decreased nitric oxide (NO) bioavailability and increased lipid oxidation are associated with progressive endothelial dysfunction. L-Citrulline, the effective precursor of L-arginine which is essential as a substrate for endothelial NO synthase (eNOS), is effective in enhancing NO-dependent signaling. However, little is known about the efficacy of L-citrulline supplementation on lipoprotein oxidation and endothelial dysfunction. Methods: Twenty-two patients (aged 41 - 64 years old) diagnosed with vasospastic angina with flow-mediated dilation (FMD) of the brachial artery (< 5.5 %) received 800 mg/day of L-citrulline for 8 weeks. FMD (%), blood NOx, asymmetric dimethylarginine (ADMA), small dense LDL, oxidized lipids, amino acids concentrations were measured before and after supplementation. Results: Compared with baseline values, FMD (%) was significantly improved at 4 and 8 weeks as well as at 4 weeks after the end of intake. L-Citrulline supplementation caused a significant lowering of plasma ADMA levels. Plasma L-arginine/ADMA ratio and NOx levels rose markedly throughout the study period. Moreover, significant reductions of serum oxidized LDL and lectin-like oxidized LDL receptor 1 (LOX-1) ligand containing ApoB (LAB), an indicator of the biological activity of oxidized lipoprotein binding to LOX-1, were observed after L-citrulline intake. Conclusions: L-Citrulline supplementation improves endothelial dysfunction, probably due to potentiating NO-dependent reactions and decreasing the state of lipoprotein oxidation in humans. PMID:26005507

  19. Mitochondrial citrulline synthesis from ammonia and glutamine in the liver of ureogenic air-breathing catfish, Clarias batrachus (Linnaeus).

    PubMed

    Kharbuli, Zaiba Y; Biswas, Kuheli; Saha, Nirmalendu

    2007-12-01

    The possible synthesis of citrulline, a rate limiting step for urea synthesis via the ornithine-urea cycle (OUC) in teleosts was tested both in the presence of ammonia and glutamine as nitrogen-donating substrates by the isolated liver mitochondria of ureogenic air-breathing walking catfish, C. batrachus. Both ammonia and glutamine could be used as nitrogen-donating substrates for the synthesis of citrulline by the isolated liver mitochondria, since the rate of citrulline synthesis was almost equal in presence of both the substrates. The citrulline synthesis by the isolated liver mitochondria requires succinate at a concentration of 0.1 mM as an energy source, and also requires the involvement of intramitochondrial carbonic anhydrase activity for supplying HCO3 as another substrate for citrulline synthesis. The rate of citrulline synthesis was further stimulated significantly by the isolated liver mitochondria of the fish after pre-exposure to 25 mM NH4Cl for 7 days. Due to possessing this biochemical adaptational strategy leading to the amelioration of ammonia toxicity mainly by channeling ammonia directly and/or via the formation of glutamine to the OUC, this air-breathing catfish could succeed in surviving in high external ammonia, which it faces in its natural habitat in certain seasons of the year.

  20. Serum metabolomics identifies citrulline as a predictor of adverse outcomes in an equine model of gut-derived sepsis.

    PubMed

    Steelman, Samantha M; Johnson, Philip; Jackson, Amy; Schulze, James; Chowdhary, Bhanu P

    2014-05-15

    Acute laminitis is an inflammatory disease of the equine foot that often occurs secondarily to sepsis or systemic inflammation associated with gastrointestinal disease. It has been suggested that laminitis is similar to multiple organ dysfunction syndrome in humans, although in horses the weight-bearing laminar epithelium of the foot appears to be the tissue most sensitive to insult and the first "organ" to fail. Metabolomics performed on serum samples collected before (Con) and after (Lmn) experimental induction of gastrointestinal-associated sepsis in six horses detected 1,177 metabolites of both mammalian and bacterial origin in equine serum. Network and correlation analyses suggested a dysregulation of fatty acid metabolism in the Lmn group, as well as an accumulation of organic acids such as lactate. Furthermore, concentrations of the amino acid citrulline were decreased in Lmn samples from all study animals, suggesting that citrulline might be useful as a biomarker to identify critically ill animals that are at risk of developing laminitis. We therefore established normal ranges of plasma citrulline concentrations in a separate group of horses (n = 36) and tested the ability of citrulline to predict adverse outcomes (laminitis or death) in critically ill horses (n = 23). Plasma citrulline was significantly lower in critically ill horses that went on to experience adverse outcomes (n = 6). Further study is required to accurately determine a diagnostic cutoff, but the present data are suggestive of the predictive value of citrulline as a biomarker for laminar failure in equine sepsis.

  1. Recognition of new citrulline-containing peptide epitopes by autoantibodies produced in vivo and in vitro by B cells of rheumatoid arthritis patients

    PubMed Central

    Szarka, Eszter; Babos, Fruzsina; Magyar, Anna; Huber, Krisztina; Szittner, Zoltán; Papp, Krisztián; Prechl, József; Pozsgay, Judit; Neer, Zsuzsa; Ádori, Monika; Nagy, György; Rojkovich, Bernadette; Gáti, Tamás; Kelemen, Judit; Baka, Zsuzsanna; Brózik, Márta; Pazár, Borbála; Poór, Gyula; Hudecz, Ferenc; Sármay, Gabriella

    2014-01-01

    Anti-citrullinated peptide/protein antibodies (ACPAs) are highly sensitive and specific markers of rheumatoid arthritis (RA). Identification of peptide epitopes that may detect different subgroups of RA patients might have diagnostic and prognostic significance. We have investigated citrulline- and arginine-containing peptide pairs derived from filaggrin, collagen or vimentin, and compared this citrulline-peptide panel with the serological assays conventionally used to detect ACPAs. Furthermore, we studied if the same citrulline-peptides identify antibody-secreting cells in in vitro cultures of RA B cells. Recognition of citrulline- and arginine-containing filaggrin, vimentin and collagen peptide epitopes were tested by Multipin ELISA system, by indirect ELISA and by a peptide-specific microarray. B cells were purified from blood by negative selection; antibody-producing cells were enumerated by ELISPOT assay. The panel composed of citrulline-peptide epitopes of filaggrin, collagen and vimentin was recognized by RA sera with a sensitivity and specificity comparable with the currently used tests. Moreover, the combined citrulline-peptide panel including the new short epitope peptide of filaggrin, fil311-315, also identified nearly one-third of RA cases that were negative for antibodies against cyclic citrullinated peptides, mutated citrullinated vimentin or for rheumatoid factor. The results with the peptide-specific microarray have shown that although most ACPAs recognizing the four citrulline peptides are IgG, some of them specifically recognizing citrulline-containing filaggrin peptides (fil311–315 and fil306–326) are IgM, and so may be produced either by newly formed activated B cells or by unswitched B memory cells. Furthermore, the citrulline-peptides of filaggrin and vimentin detect ACPA-producing cells, and so could also be applied to study the B cells of RA patients. PMID:24116744

  2. The rheumatoid arthritis synovial fluid citrullinome reveals novel citrullinated epitopes in apolipoprotein E, myeloid nuclear differentiation antigen, and β-actin.

    PubMed

    van Beers, Joyce J B C; Schwarte, Carla M; Stammen-Vogelzangs, Judith; Oosterink, Els; Božič, Borut; Pruijn, Ger J M

    2013-01-01

    To generate a catalog of citrullinated proteins that are present in the synovia of patients with rheumatoid arthritis (RA) and to elucidate their relevance for the anti-citrullinated protein antibody response in RA. Polypeptides isolated from the synovial fluid of patients with RA were identified by mass spectrometry. Three proteins (apolipoprotein E [Apo E], myeloid nuclear differentiation antigen [MNDA], and β-actin) were studied in more detail, using immunoprecipitation and Western blotting. The presence of autoantibodies to synthetic peptides derived from these proteins in sera from patients with RA, sera from patients with other diseases, and sera from healthy control subjects was studied by enzyme-linked immunosorbent assay (ELISA). RA synovial fluid samples displayed several distinct patterns of citrullinated proteins. Using mass spectrometry, (fragments of) 192 proteins were identified, including 53 citrullinated proteins, some of which contained multiple citrullinated residues. In addition to previously reported citrullinated proteins in RA synovia (e.g., vimentin and fibrinogen), a series of novel citrullinated proteins, including Apo E, MNDA, β-actin, and cyclophilin A, was identified. Immunoprecipitation experiments confirmed the citrullination of Apo E and MNDA. ELISAs demonstrated the presence of autoreactive citrullinated epitopes in Apo E, MNDA, and β-actin. Synovial fluid samples from the inflamed joints of patients with RA contain many citrullinated proteins. Citrullinated Apo E, MNDA, and β-actin are novel antigens identified in RA synovial fluid, and only a limited number of their citrullinated epitopes are targeted by the immune system in RA. Copyright © 2013 by the American College of Rheumatology.

  3. Diabetic nephropathy is resistant to oral l-arginine or l-citrulline supplementation

    PubMed Central

    You, Hanning; Gao, Ting; Cooper, Timothy K.; Morris, Sidney M.

    2014-01-01

    Our recent publication showed that pharmacological blockade of arginases confers kidney protection in diabetic nephropathy via a nitric oxide (NO) synthase (NOS)3-dependent mechanism. Arginase competes with endothelial NOS (eNOS) for the common substrate l-arginine. Lack of l-arginine results in reduced NO production and eNOS uncoupling, which lead to endothelial dysfunction. Therefore, we hypothesized that l-arginine or l-citrulline supplementation would ameliorate diabetic nephropathy. DBA mice injected with multiple low doses of vehicle or streptozotocin (50 mg/kg ip for 5 days) were provided drinking water with or without l-arginine (1.5%, 6.05 g·kg−1·day−1) or l-citrulline (1.66%, 5.73 g·kg−1·day−1) for 9 wk. Nonsupplemented diabetic mice showed significant increases in albuminuria, blood urea nitrogen, glomerular histopathological changes, kidney macrophage recruitment, kidney TNF-α and fibronectin mRNA expression, kidney arginase activity, kidney arginase-2 protein expression, and urinary oxidative stress along with a significant reduction of nephrin and eNOS protein expression and kidney nitrite + nitrate compared with normal mice after 9 wk of diabetes. Surprisingly, l-arginine or l-citrulline supplementation in diabetic mice did not affect any of these parameters despite greatly increasing kidney and plasma arginine levels. These findings demonstrate that chronic l-arginine or l-citrulline supplementation does not prevent or reduce renal injury in a model of type 1 diabetes. PMID:25320354

  4. Combining citrulline with atorvastatin preserves glucose homeostasis in a murine model of diet-induced obesity.

    PubMed

    Capel, Frédéric; Chabrier, Gwladys; Pitois, Elodie; Rigaudière, Jean-Paul; Le Plenier, Servane; Durand, Christine; Jouve, Chrystèle; de Bandt, Jean-Pascal; Cynober, Luc; Moinard, Christophe; Morio, Béatrice

    2015-10-01

    NO is a crucial regulator of energy and lipid metabolism, whose homeostasis is compromised during obesity. Combination of citrulline and atorvastatin potentiated NO production in vitro. Here we have assessed the effects of this combination in mice with diet-induced obesity (DIO). C57BL/6J male mice were given a standard diet (control) or a high fat-high sucrose diet (DIO) for 8 weeks. DIO mice were then treated with DIO alone, DIO with citrulline, DIO with atorvastatin or DIO with citrulline and atorvastatin (DIOcit-stat) for 3 weeks. Thereafter, body composition, glucose tolerance, insulin sensitivity and liver fat metabolism were measured. DIOcit-stat mice showed lower body weight, fat mass and epididymal fat depots compared with other DIO groups. Unlike other DIO groups, glucose tolerance and insulin sensitivity of DIOcit-stat, along with blood glucose and insulin concentrations in response to feeding, were restored to control values. Refeeding-induced changes in liver lipogenic activity were also reduced in DIOcit-stat mice compared with those of DIO animals. This was associated with decreased gene expression of the transcription factor SREBP-1, liver X receptor α, ChREBP and of target lipogenic enzymes in the liver of DIOcit-stat mice compared with those of other DIO groups. The citrulline-atorvastatin combination prevented fat mass accumulation and maintained glucose homeostasis in DIO mice. Furthermore, it potentiated inhibition of hepatic de novo lipogenesis activity. This combination has potential for preservation of glucose homeostasis in patients receiving statin therapy. © 2015 The British Pharmacological Society.

  5. The effects on plasma L-arginine levels of combined oral L-citrulline and L-arginine supplementation in healthy males.

    PubMed

    Suzuki, Takashi; Morita, Masahiko; Hayashi, Toshio; Kamimura, Ayako

    2017-02-01

    We investigated the effects of combining 1 g of l-citrulline and 1 g of l-arginine as oral supplementation on plasma l-arginine levels in healthy males. Oral l-citrulline plus l-arginine supplementation more efficiently increased plasma l-arginine levels than 2 g of l-citrulline or l-arginine, suggesting that oral l-citrulline and l-arginine increase plasma l-arginine levels more effectively in humans when combined.

  6. L-Citrulline, the by-product of nitric oxide synthesis, decreases vascular smooth muscle cell proliferation.

    PubMed

    Ruiz, E; Del Rio, M; Somoza, B; Ganado, P; Sanz, M; Tejerina, T

    1999-07-01

    Endothelium injury plays an important role in atherosclerosis. Damage to the endothelium results in vascular smooth muscle cell proliferation. Natriuretic peptides present a potent antimitogenic action, mediating their biological effects via the binding of guanylate cyclase-linked atrial natriuretic peptide (ANP) receptor and the production of cyclic GMP. In a previous study, we demonstrated that L-citrulline, the by-product of nitric oxide synthesis, could relax rabbit aortic rings by stimulating the guanylate cyclase-linked ANP receptor. In this work, we investigated the effect of L-citrulline on vascular smooth muscle cell proliferation. L-Citrulline (10(-8) M) significantly decreased rat aortic (A10 cell line) vascular smooth muscle proliferation. The percentage of inhibition exerted by L-citrulline on days 3, 5, and 7 of the proliferation curve was 20.0 +/- 0.5%, 37.5 +/- 8.3%, and 28. 5 +/- 7.2%, respectively. In addition, L-citrulline also inhibited serum-induced DNA synthesis, measured as 5-bromo-2'-deoxyuridine incorporation. 5-Bromo-2'-deoxyuridine incorporation into nuclei of vehicle-treated cells was 40.5 +/- 2.4%, whereas in L-citrulline-treated cells the percentage decreased to 36.0 +/- 4.1%, 29.1 +/- 2.0% (P <.01, n = 4), 30.5 +/- 2.4% (P <.05, n = 4), and 23.1 +/- 0.5% (P <.001, n = 4) for 10(-10), 10(-9), 10(-8), and 10(-7) M, respectively. Zaprinast, a phosphodiesterase type V inhibitor, enhanced 5-bromo-2'-deoxyuridine incorporation in serum-stimulated cells. Moreover, L-citrulline inhibition of serum-stimulated DNA synthesis was abolished by HS-142-1 (10(-5) M), an ANP receptor antagonist. In another group of experiments, L-citrulline was shown to increase intracellular cyclic GMP levels from 2.1 +/- 0.2 pmol of cGMP/mg protein to 4.1 +/- 0.1 for L-citrulline (10(-8) M) (P <.001, n = 3). These findings suggest that L-citrulline decreases vascular smooth muscle cell proliferation in the A10 cell line by acting on DNA synthesis by mechanisms that

  7. Streptococcus pyogenes Arginine and Citrulline Catabolism Promotes Infection and Modulates Innate Immunity

    PubMed Central

    Cusumano, Zachary T.; Watson, Michael E.

    2014-01-01

    A bacterium's ability to acquire nutrients from its host during infection is an essential component of pathogenesis. For the Gram-positive pathogen Streptococcus pyogenes, catabolism of the amino acid arginine via the arginine deiminase (ADI) pathway supplements energy production and provides protection against acid stress in vitro. Its expression is enhanced in murine models of infection, suggesting an important role in vivo. To gain insight into the function of the ADI pathway in pathogenesis, the virulence of mutants defective in each of its enzymes was examined. Mutants unable to use arginine (ΔArcA) or citrulline (ΔArcB) were attenuated for carriage in a murine model of asymptomatic mucosal colonization. However, in a murine model of inflammatory infection of cutaneous tissue, the ΔArcA mutant was attenuated but the ΔArcB mutant was hyperattenuated, revealing an unexpected tissue-specific role for citrulline metabolism in pathogenesis. When mice defective for the arginine-dependent production of nitric oxide (iNOS−/−) were infected with the ΔArcA mutant, cutaneous virulence was rescued, demonstrating that the ability of S. pyogenes to utilize arginine was dispensable in the absence of nitric oxide-mediated innate immunity. This work demonstrates the importance of arginine and citrulline catabolism and suggests a novel mechanism of virulence by which S. pyogenes uses its metabolism to modulate innate immunity through depletion of an essential host nutrient. PMID:24144727

  8. Does Citrulline Have Protective Effects on Liver Injury in Septic Rats?

    PubMed Central

    Cai, Bin; Luo, Yu-long; Wang, Shi-jun; Wei, Wei-yuan; Zhang, Xue-hui; Huang, Wei; Li, Tong; Zhang, Meng; Wu, Nan; Roodrajeetsing, Gopaul; Zhang, Sen

    2016-01-01

    Citrulline (Cit) supplementation was proposed to serve as a therapeutic intervention to restore arginine (Arg) concentrations and improve related functions in sepsis. This study explored whether citrulline had positive effects on liver injury and cytokine release in the early stages of sepsis. The cecal ligation and puncture (CLP) model was utilized in our study. Rats were divided into four groups: normal, Cit, CLP, and CLP+Cit. The CLP group and CLP+Cit group were separated into 6-, 12-, and 24-hour groups, according to the time points of sacrifice after surgery. Intragastric administration of L-citrulline was applied to rats in Cit and CLP+Cit groups before surgery. Serum AST and ALT levels and levels of MDA, SOD, NO, and iNOS in the liver tissues were evaluated. Plasma concentrations of Cit and Arg were assessed using HPLC-MS/MS. Serum concentrations of cytokines and chemokines were calculated by Luminex. Results showed SOD activities of CLP+Cit groups were significantly higher than that of CLP groups, contrasting with the MDA and NO levels which were significantly lower in CLP+Cit groups than in CLP groups. In addition, plasma concentrations of TNF-α, IL-6, and IL-1β were significantly lower in the CLP+Cit 6-hour group than in the CLP 6-hour group. PMID:27195281

  9. Identification and characterisation of citrullinated antigen-specific B cells in peripheral blood of patients with rheumatoid arthritis.

    PubMed

    Kerkman, Priscilla F; Fabre, Emeline; van der Voort, Ellen I H; Zaldumbide, Arnaud; Rombouts, Yoann; Rispens, Theo; Wolbink, Gertjan; Hoeben, Rob C; Spits, Hergen; Baeten, Dominique L P; Huizinga, Tom W J; Toes, René E M; Scherer, Hans U

    2016-06-01

    Immunity to citrullinated antigens is a hallmark of rheumatoid arthritis (RA). We set out to elucidate its biology by identifying and characterising citrullinated antigen-specific B cells in peripheral blood of patients with RA. Differentially labelled streptavidin and extravidin tetramers were conjugated to biotinylated CCP2 or control antigens and used in flow cytometry to identify citrullinated antigen-specific B cells in peripheral blood. Tetramer-positive and tetramer-negative B cells were isolated by fluorescence activated cell sorting (FACS) followed by in vitro culture and analysis of culture supernatants for the presence of antibodies against citrullinated protein antigens (ACPA) by ELISA. Cells were phenotypically characterised by flow cytometry. By combining differentially labelled CCP2 tetramers, we successfully separated citrullinated antigen-specific B cells from non-specific background signals. Isolated tetramer-positive B cells, but not tetramer-negative cells, produced large amounts of ACPA upon in vitro stimulation. Phenotypic analyses revealed that citrullinated antigen-specific B cells displayed markers of class-switched memory B cells and plasmablasts, whereas only few cells displayed a naïve phenotype. The frequency of tetramer-positive cells was high (up to 1/500 memory B cells with a median of 1/12 500 total B cells) and correlated with ACPA serum titres and spontaneous ACPA production in culture. We developed a technology to identify and isolate citrullinated antigen-specific B cells from peripheral blood of patients with RA. Most cells have a memory phenotype, express IgA or IgG and are present in relatively high frequencies. These data pave the path for a direct and detailed molecular characterisation of ACPA-expressing B cells and could lead to the identification of novel therapeutic targets. 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/

  10. Correlations of plasma citrulline levels with clinical and endoscopic score and blood markers according to small bowel involvement in pediatric Crohn disease.

    PubMed

    Lee, Eun Hye; Ko, Jae Sung; Seo, Jeong Kee

    2013-11-01

    Several studies have indicated that plasma citrulline levels reflect the extent of mucosal injury of the small intestine. This study was performed to determine whether plasma citrulline levels correlate with the disease activity in pediatric patients with Crohn disease (CD). A total of 63 CD and 23 ulcerative colitis (UC) patients were included in this study. Disease severity was assessed by pediatric CD activity index (PCDAI), pediatric UC activity index, simplified endoscopic activity score for CD, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). The correlations among these variables and plasma citrulline levels were evaluated. We performed subgroup analysis whether correlations between plasma citrulline levels and disease activity depend on small bowel involvement in patients with CD. The plasma citrulline levels correlated negatively with CRP (r = -0.332, P = 0.008), ESR (r = -0.290, P = 0.022), and PCDAI (r = -0.424, P = 0.001) in patients with CD. The plasma citrulline levels were significantly lower in patients with jejunal involvement than in those without (P = 0.027). In subgroup analysis, patients with CD with jejunal involvement showed significantly negative correlations of plasma citrulline levels with CRP (r = -0.628, P = 0.016) and PCDAI (r = -0.632, P = 0.015); however, patients with CD without jejunal involvement revealed no correlations of plasma citrulline levels with CRP and PCDAI. There were no significant correlations between plasma citrulline levels and simplified endoscopic activity score for CD. There were no significant correlations of plasma citrulline levels with CRP, ESR, and pediatric UC activity index in patients with UC. Plasma citrulline levels correlated with disease severity as measured by PCDAI, CRP, and ESR in pediatric patients with CD with jejunal involvement.

  11. Citrulline Protects Streptococcus pyogenes from Acid Stress Using the Arginine Deiminase Pathway and the F1Fo-ATPase

    PubMed Central

    Cusumano, Zachary T.

    2015-01-01

    ABSTRACT A common stress encountered by both pathogenic and environmental bacteria is exposure to a low-pH environment, which can inhibit cell growth and lead to cell death. One major defense mechanism against this stress is the arginine deiminase (ADI) pathway, which catabolizes arginine to generate two ammonia molecules and one molecule of ATP. While this pathway typically relies on the utilization of arginine, citrulline has also been shown to enter into the pathway and contribute to protection against acid stress. In the pathogenic bacterium Streptococcus pyogenes, the utilization of citrulline has been demonstrated to contribute to pathogenesis in a murine model of soft tissue infection, although the mechanism underlying its role in infection is unknown. To gain insight into this question, we analyzed a panel of mutants defective in different steps in the ADI pathway to dissect how arginine and citrulline protect S. pyogenes in a low-pH environment. While protection provided by arginine utilization occurred through the buffering of the extracellular environment, citrulline catabolism protection was pH independent, requiring the generation of ATP via the ADI pathway and a functional F1Fo-ATP synthase. This work demonstrates that arginine and citrulline catabolism protect against acid stress through distinct mechanisms and have unique contributions to virulence during an infection. IMPORTANCE An important aspect of bacterial pathogenesis is the utilization of host-derived nutrients during an infection for growth and virulence. Previously published work from our lab identified a unique role for citrulline catabolism in Streptococcus pyogenes during a soft tissue infection. The present article probes the role of citrulline utilization during this infection and its contribution to protection against acid stress. This work reveals a unique and concerted action between the catabolism of citrulline and the F1Fo-ATPase that function together to provide protection for

  12. Quantitative analysis of 15N labeled positional isomers of glutamine and citrulline via electrospray ionization tandem mass spectrometry of their dansyl derivatives

    USDA-ARS?s Scientific Manuscript database

    The enteral metabolism of glutamine and citrulline are intertwined because, while glutamine is one of the main fuel sources for the enterocyte, citrulline is one of its products. It has been shown that the administration of 15N labeled glutamine results in the incorporation of the 15N label into cit...

  13. Enzymatic syntheses of carbamyl phosphate, L-citrulline, and N-carbamyl L-aspartate labeled with either 13N or 11C.

    PubMed

    Gelbard, A S; Kaseman, D S; Rosenspire, K C; Meister, A

    1985-01-01

    [13N]- and [11C]carbamyl phosphate, L-[omega-13N]citrulline, L-[ureido-11C]citrulline, [carbamyl-13N]- and [carbamyl-11C]carbamyl-L-aspartate were synthesized using carbamyl phosphate synthetase co-immobilized with either aspartate transcarbamylase or ornithine transcarbamylase. Carbamyl L-[13N]aspartate was enzymatically prepared from carbamyl phosphate and L-[13N]aspartate. The tissue distribution of radioactivity in mice after injection of radiolabeled ammonia, carbamyl phosphate or citrulline was studied. The tissue distribution of isotope derived from [13N]carbamyl phosphate and [13N]ammonia were similar, with the exception of liver, brain and pancreas, in which 13NH3 uptake was higher after retroorbital injection. The distribution of label derived from L-[omega-13N]- and L-[ureido-11C]citrulline was similar. Substantial tumor (Sarcoma-180) uptake of label from L-citrulline was observed.

  14. Extracellular citrulline levels in the nucleus accumbens during the acquisition and extinction of a classical conditioned reflex with pain reinforcement.

    PubMed

    Savel'ev, S A; Saul'skaya, N B

    2007-03-01

    Studies on Sprague-Dawley rats using in vivo microdialysis and HPLC showed that the acquisition and performance of a classical conditioned reflex with pain reinforcement was accompanied by increases in the concentrations of citrulline (a side product of nitric oxide formation) and arginine (the substrate of NO synthase) in the intercellular space of the nucleus accumbens. During extinction of the reflex, there was a decrease in the elevation of extracellular citrulline in this brain structure, which correlated with the extent of extinction of the reflex. Recovery of the reflex led to increases in arginine and citrulline levels in the nucleus accumbens. These data suggest that there is an increase in nitric oxide production in the nucleus accumbens during the acquisition and performance of a classical conditioned reflex with pain reinforcement, which decreases as the reflex is extinguished and recovers with recovery of the reflex.

  15. Effect of citrulline, urea, ethanol, and urease on the formation of ethyl carbamate in soybean paste model system.

    PubMed

    Kim, Yong Gun; Lyu, Jihye; Kim, Mina K; Lee, Kwang-Geun

    2015-12-15

    The aim of this study was to determine the effect of urease on the formation of ethyl carbamate (EC) in the presence of previously known precursors of EC (citrulline, urea, and ethanol) using a soybean paste model system. The levels of EC were quantitatively determined by gas chromatography-mass spectrometry (GC-MS) every five days for a 30-day period. After 30 days fermentation, the concentration of EC increased significantly by 135.2%, 242.2%, and 3757.1% when the precursors (citrulline, urea and ethanol) were added to the model system, respectively (p<0.05). Urease significantly decreased the level of EC by 38.4%, 18.8%, and 17.3% when citrulline, urea, and ethanol were added to the model system, respectively (p<0.05). Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Plasma citrulline as a quantitative biomarker of HIV-associated villous atrophy in a tropical enteropathy population.

    PubMed

    Papadia, Cinzia; Kelly, Paul; Caini, Saverio; Corazza, Gino Roberto; Shawa, Tamara; Franzè, Angelo; Forbes, Alastair; Di Sabatino, Antonio

    2010-12-01

    Studies have shown that the circulating citrulline concentration is decreased in patients with proximal small bowel villous atrophy from coeliac disease and more so in patients with extensive damage to the intestinal mucosa, but there have been few data on HIV enteritis and tropical enteropathy (TE). Our primary aim was to correlate serum citrulline with the degree of reduction of the enterocyte mass in HIV-infected patients with TE. Postabsorptive fasting serum citrulline was measured in 150 TE pts, 44 of whom had HIV infection, using reverse phase, high performance liquid chromatography. Absorptive capacity and permeability were measured after intrajejunal instillation of 4 sugars (5 g lactulose, 1 g L-rhamnose, 0.5 g D-xylose, 0.2 g 3-O methyl D glucose) with assay by thin-layer chromatography. Morphometric analysis was carried out on jejunal biopsies. In HIV positive patients, the median serum citrulline was significantly lower (median 19, interquartile range (IQR) 17-24 μmol/L) than in HIV negative patients (median 27, IQR 23-33 μmol/L; p < 0.001). There were statistically significant correlations (p < 0.005) between citrulline and: crypt depth; villous height/crypt depth ratio; Shenk-Klipstein score; and xylose absoption, only in the HIV positive. Serum citrulline concentration appears to be a quantitative biomarker of small bowel mass integrity in HIV positive enteropathy and deserves assessment as a surrogate for monitoring anti-retroviral therapy. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  17. L-citrulline prevents alveolar and vascular derangement in a rat model of moderate hyperoxia-induced lung injury.

    PubMed

    Grisafi, Davide; Tassone, Evelyne; Dedja, Arben; Oselladore, Barbara; Masola, Valentina; Guzzardo, Vincenza; Porzionato, Andrea; Salmaso, Roberto; Albertin, Giovanna; Artusi, Carlo; Zaninotto, Martina; Onisto, Maurizio; Milan, Anna; Macchi, Veronica; De Caro, Raffaele; Fassina, Ambrogio; Bordigato, Michela Alfiero; Chiandetti, Lino; Filippone, Marco; Zaramella, Patrizia

    2012-08-01

    Moderate normobaric hyperoxia causes alveolar and vascular lung derangement in the newborn rat. Endogenous nitric oxide (NO), which promotes lung growth, is produced from the metabolism of L-arginine to L-citrulline in endothelial cells. We investigated whether administering L-citrulline by raising the serum levels of L-arginine and enhancing NO endogenous synthesis attenuates moderate hyperoxia-induced lung injury. Newborn rats were exposed to FiO(2) = 0.6 or room air for 14 days to induce lung derangement and then were administered L-citrulline or a vehicle (sham). Lung histopathology was studied with morphometric features. Lung tissues and bronchoalveolar lavage fluid (BALF) were collected for analysis. Lung vascular endothelial growth factor (VEGF), nitric oxide synthase (eNOS), and matrix metalloproteinase 2 (MMP2) gene and protein expressions were assessed. Serum L-arginine rose in the L-citr + hyperoxia group (p = 0.05), as well as the Von Willebrand factor stained vessels count (p = 0.0008). Lung VEGF immune staining, localized on endothelial cells, was weaker in the sections under hyperoxia than the L-citr + hyperoxia and room air groups. This pattern was comparable with the VEGF gene and protein expression profiles. Mean alveolar size increased in the untreated hyperoxia and sham-treated groups compared with the groups reared in room air or treated with L-citrulline under exposure to hyperoxia (p = 0.0001). Lung VEGF and eNOS increased in the L-citrulline-treated rats, though this treatment did not change MMP2 gene expression but regulated the MMP2 active protein, which rose in BALF (p = 0.003). We conclude that administering L: -citrulline proved effective in improving alveolar and vascular growth in a model of oxygen-induced pulmonary damage, suggesting better lung growth and matrix regulation than in untreated groups.

  18. Identification of an immunodominant peptide from citrullinated tenascin-C as a major target for autoantibodies in rheumatoid arthritis

    PubMed Central

    Schwenzer, Anja; Jiang, Xia; Mikuls, Ted R; Payne, Jeffrey B; Sayles, Harlan R; Quirke, Anne-Marie; Kessler, Benedikt M; Fischer, Roman; Venables, Patrick J; Lundberg, Karin; Midwood, Kim S

    2016-01-01

    Objectives We investigated whether citrullinated tenascin-C (cTNC), an extracellular matrix protein expressed at high levels in the joints of patients with rheumatoid arthritis (RA), is a target for the autoantibodies in RA. Methods Citrullinated sites were mapped by mass spectrometry in the fibrinogen-like globe (FBG) domain of tenascin-C treated with peptidylarginine deiminases (PAD) 2 and 4. Antibodies to cyclic peptides containing citrullinated sites were screened in sera from patients with RA by ELISA. Potential cross-reactivity with well-established anticitrullinated protein antibody (ACPA) epitopes was tested by inhibition assays. The autoantibody response to one immunodominant cTNC peptide was then analysed in 101 pre-RA sera (median 7 years before onset) and two large independent RA cohorts. Results Nine arginine residues within FBG were citrullinated by PAD2 and PAD4. Two immunodominant peptides cTNC1 (VFLRRKNG-cit-ENFYQNW) and cTNC5 (EHSIQFAEMKL-cit-PSNF-cit-NLEG-cit-cit-KR) were identified. Antibodies to both showed limited cross-reactivity with ACPA epitopes from α-enolase, vimentin and fibrinogen, and no reactivity with citrullinated fibrinogen peptides sharing sequence homology with FBG. cTNC5 antibodies were detected in 18% of pre-RA sera, and in 47% of 1985 Swedish patients with RA and 51% of 287 North American patients with RA. The specificity was 98% compared with 160 healthy controls and 330 patients with osteoarthritis. Conclusions There are multiple citrullination sites in the FBG domain of tenascin-C. Among these, one epitope is recognised by autoantibodies that are detected years before disease onset, and which may serve as a useful biomarker to identify ACPA-positive patients with high sensitivity and specificity in established disease. PMID:26659718

  19. DR1001 presents ‘altered-self’ peptides derived from joint associated proteins by accepting citrulline in three of its binding pockets

    PubMed Central

    James, Eddie A.; Moustakas, Antonis K.; Bui, John; Papadopoulos, George K.; Bondinas, George; Buckner, Jane H.; Kwok, William W.

    2010-01-01

    Objective HLA-DRB1*1001 (DR1001) is a shared epitope allele associated with rheumatoid arthritis. The objectives of this study were to assess the capacity of DR1001 to accommodate citrulline in its binding pockets and to identify citrullinated T cell epitopes derived from joint associated proteins. Methods The binding of peptide derivatives containing citrulline, arginine, and other amino acid substitutions was measured. A prediction algorithm was then developed to identify arginine containing sequences from joint associated proteins that preferentially bind to DR1001 upon citrullination. Unmodified and citrullinated versions of these sequences were synthesized and utilized to stimulate CD4+ T cells from healthy subjects and rheumatoid arthritis patients. Responses were measured by MHC class II tetramer staining and confirmed by isolating CD4+ T cell clones. Results DR1001 accepted citrulline, but not arginine in three of its anchoring pockets. The prediction algorithm identified sequences that preferentially bound to DR1001 with arginine replaced by citrulline. Three of these sequences elicited CD4+ T cell responses. T cell clones specific for these sequences proliferated only in response to citrullinated peptides. Conclusions Conversion of arginine to citrulline generates ‘altered-self’ peptides that can be bound and presented by DR1001. Responses to these peptides implicate the corresponding proteins (fibrinogen α, fibrinogen β and cartilage intermediate layer protein) as relevant antigens. Preferential responses to citrullinated sequences suggests that altered peptide binding affinity due to this post-translational modification may be an important factor in the initiation or progression of RA. As such, measuring responsiveness to these peptides may be useful for immune monitoring. PMID:20533291

  20. Acute Citrulline-Malate Supplementation and High-Intensity Cycling Performance.

    PubMed

    Cunniffe, Brian; Papageorgiou, Maria; OʼBrien, Barbara; Davies, Nathan A; Grimble, George K; Cardinale, Marco

    2016-09-01

    Cunniffe, B, Papageorgiou, M, O'Brien, B, Davies, NA, Grimble, GK, and Cardinale, M. Acute citrulline-malate supplementation and high-intensity cycling performance. J Strength Cond Res 30(9): 2638-2647, 2016-Dietary L-citrulline-malate (CM) consumption has been suggested to improve skeletal muscle metabolism and contractile efficiency, which would be expected to predispose exercising individuals to greater fatigue resistance. The purpose of this study was to examine the effects of CM supplementation on acid-base balance and high-intensity exercise performance. In a double-blind, placebo-controlled, crossover study, 10 well-trained males consumed either 12 g of CM (in 400 ml) or lemon sugar-free cordial (placebo [PL]) 60 minutes before completion of 2 exercise trials. Each trial consisted of subjects performing 10 (×15 seconds) maximal cycle sprints (with 30-second rest intervals) followed by 5 minutes recovery before completing a cycle time-to-exhaustion test (TTE) at 100% of individual peak power (PP). Significant increases in plasma concentrations of citrulline (8.8-fold), ornithine (3.9-fold), and glutamine (1.3-fold) were observed 60 minutes after supplementation in the CM trial only (p ≤ 0.05) and none of the subjects experienced gastrointestinal side-effects during testing. Significantly higher exercise heart rates were observed in CM condition (vs. PL) although no between trial differences in performance related variables (TTE: [120 ± 61 seconds CM vs. 113 ± 50 seconds PL]), PP or mean power, ([power fatigue index: 36 ± 16% CM vs. 28 ± 18% PL]), subjective rating of perceived exertion or measures of acid-base balance (pH, lactate, bicarbonate, base-excess) were observed (p > 0.05). This study demonstrated that acute supplementation of 12 g CM does not provide acute ergogenic benefits using the protocol implemented in this study in well-trained males.

  1. Reengineering of a Corynebacterium glutamicum l-Arginine and l-Citrulline Producer▿

    PubMed Central

    Ikeda, Masato; Mitsuhashi, Satoshi; Tanaka, Kenji; Hayashi, Mikiro

    2009-01-01

    Toward the creation of a robust and efficient producer of l-arginine and l-citrulline (arginine/citrulline), we have performed reengineering of a Corynebacterium glutamicum strain by using genetic information of three classical producers. Sequence analysis of their arg operons identified three point mutations (argR123, argG92up, and argG45) in one producer and one point mutation (argB26 or argB31) in each of the other two producers. Reconstitution of the former three mutations or of each argB mutation on a wild-type genome led to no production. Combined introduction of argB26 or argB31 with argR123 into a wild type gave rise to arginine/citrulline production. When argR123 was replaced by an argR-deleted mutation (ΔargR), the production was further increased. The best mutation set, ΔargR and argB26, was used to screen for the highest productivity in the backgrounds of different wild-type strains of C. glutamicum. This yielded a robust producer, RB, but the production was still one-third of that of the best classical producer. Transcriptome analysis revealed that the arg operon of the classical producer was much more highly upregulated than that of strain RB. Introduction of leuC456, a mutation derived from a classical l-lysine producer and provoking global induction of the amino acid biosynthesis genes, including the arg operon, into strain RB led to increased production but incurred retarded fermentation. On the other hand, replacement of the chromosomal argB by heterologous Escherichia coli argB, natively insensitive to arginine, caused a threefold-increased production without retardation, revealing that the limitation in strain RB was the activity of the argB product. To overcome this, in addition to argB26, the argB31 mutation was introduced into strain RB, which caused higher deregulation of the enzyme and resulted in dramatically increased production, like the strain with E. coli argB. This reconstructed strain displayed an enhanced performance, thus

  2. Circulating levels of citrullinated and MMP-degraded vimentin (VICM) in liver fibrosis related pathology.

    PubMed

    Vassiliadis, Efstathios; Oliveira, Claudia P; Alvares-da-Silva, Mario R; Zhang, Chen; Carrilho, Flair J; Stefano, Jose T; Rabelo, Fabiola; Pereira, Leila; Kappel, Camila R; Henriksen, Kim; Veidal, Sanne Skovgård; Vainer, Ben; Duffin, Kevin L; Christiansen, Claus; Leeming, Diana J; Karsdal, Morten

    2012-01-01

    To investigate whether increased levels of vimentin citrullinated peptides identified by MS in articular cartilage can be measured in pathologies other than rheumatoid arthritis and be utilised for diagnostic purposes. A monoclonal antibody against the sequence RLRSSVPGV-citrulline (VICM) was developed and evaluated in a carbon tetrachloride (CCl(4)) (n=52 + 28 controls) rat model of liver fibrosis and two clinical cohorts of adult patients with hepatitis C (HCV) (n=92) and non-alcoholic fatty liver disease (NAFLD) (n=62), and compared to healthy controls. In CCl(4)-treated rats, mean systemic VICM levels increased 31% at week 12 (176 ng/mL, P<0.001), 41.7% at weeks 16 (190 ng/mL, P<0.001), 49.2% at weeks 20 (200 ng/ml, P<0.001), compared to controls (134 ng/mL). VICM levels correlated with total hepatic collagen determined by Sirius red staining of rat livers (r=0.75, P<0.05). In the HCV cohort, when stratified according to the METAVIR F score, VICM levels were 63% higher in F0 (632 ng/mL ±75, p<0.05), 54% in F1 (597 ng/mL ±41.3, p<0.05) and 62% in F2 (628 ng/mL ±59, p<0.05) all compared to controls. In the NAFLD cohort, VICM levels were 20.6% higher in F0 (339 ±12 ng/mL, P<0.05), 23.8% in F1 (348 ±12 ng/mL, P<0.05) and 28.8% in F2 (362 ±25 P<0.05). We demonstrated increased serological levels of citrullinated and MMP degraded vimentin in an animal model of liver fibrosis and in early fibrosis associated with HCV and NAFLD patients. These data suggest that citrullinated and MMP degraded proteins are also present in liver fibrosis.

  3. Citrullination of Histone H3 Interferes with HP1-Mediated Transcriptional Repression

    PubMed Central

    Sharma, Priyanka; Azebi, Saliha; England, Patrick; Christensen, Tove; Møller-Larsen, Anné; Petersen, Thor; Batsché, Eric; Muchardt, Christian

    2012-01-01

    Multiple Sclerosis (MS) is an autoimmune disease associated with abnormal expression of a subset of cytokines, resulting in inappropriate T-lymphocyte activation and uncontrolled immune response. A key issue in the field is the need to understand why these cytokines are transcriptionally activated in the patients. Here, we have examined several transcription units subject to pathological reactivation in MS, including the TNFα and IL8 cytokine genes and also several Human Endogenous RetroViruses (HERVs). We find that both the immune genes and the HERVs require the heterochromatin protein HP1α for their transcriptional repression. We further show that the Peptidylarginine Deiminase 4 (PADI4), an enzyme with a suspected role in MS, weakens the binding of HP1α to tri-methylated histone H3 lysine 9 by citrullinating histone H3 arginine 8. The resulting de-repression of both cytokines and HERVs can be reversed with the PADI-inhibitor Cl-amidine. Finally, we show that in peripheral blood mononuclear cells (PBMCs) from MS patients, the promoters of TNFα, and several HERVs share a deficit in HP1α recruitment and an augmented accumulation of histone H3 with a double citrulline 8 tri-methyl lysine 9 modifications. Thus, our study provides compelling evidence that HP1α and PADI4 are regulators of both immune genes and HERVs, and that multiple events of transcriptional reactivation in MS patients can be explained by the deficiency of a single mechanism of gene silencing. PMID:23028349

  4. SMARCAD1 Contributes to the Regulation of Naive Pluripotency by Interacting with Histone Citrullination.

    PubMed

    Xiao, Shu; Lu, Jia; Sridhar, Bharat; Cao, Xiaoyi; Yu, Pengfei; Zhao, Tianyi; Chen, Chieh-Chun; McDee, Darina; Sloofman, Laura; Wang, Yang; Rivas-Astroza, Marcelo; Telugu, Bhanu Prakash V L; Levasseur, Dana; Zhang, Kang; Liang, Han; Zhao, Jing Crystal; Tanaka, Tetsuya S; Stormo, Gary; Zhong, Sheng

    2017-03-28

    Histone citrullination regulates diverse cellular processes. Here, we report that SMARCAD1 preferentially associates with H3 arginine 26 citrullination (H3R26Cit) peptides present on arrays composed of 384 histone peptides harboring distinct post-transcriptional modifications. Among ten histone modifications assayed by ChIP-seq, H3R26Cit exhibited the most extensive genomewide co-localization with SMARCAD1 binding. Increased Smarcad1 expression correlated with naive pluripotency in pre-implantation embryos. In the presence of LIF, Smarcad1 knockdown (KD) embryonic stem cells lost naive state phenotypes but remained pluripotent, as suggested by morphology, gene expression, histone modifications, alkaline phosphatase activity, energy metabolism, embryoid bodies, teratoma, and chimeras. The majority of H3R26Cit ChIP-seq peaks occupied by SMARCAD1 were associated with increased levels of H3K9me3 in Smarcad1 KD cells. Inhibition of H3Cit induced H3K9me3 at the overlapping regions of H3R26Cit peaks and SMARCAD1 peaks. These data suggest a model in which SMARCAD1 regulates naive pluripotency by interacting with H3R26Cit and suppressing heterochromatin formation. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  5. Citrullination as early-stage indicator of cell response to Single-Walled Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Mohamed, Bashir Mustafa; Movia, Dania; Knyazev, Anton; Langevin, Dominique; Davies, Anthony Mitchell; Prina-Mello, Adriele; Volkov, Yuri

    2013-01-01

    Single-walled carbon nanotubes (SWCNTs) have been widely explored as potential technologies for information systems and medical applications. The impact of SWCNTs on human health is of prime concern, if SWCNTs have a future in the manufacturing industry. This study proposes a novel, inflammation-independent paradigm of toxicity for SWCNTs, identifying the protein citrullination process as early-stage indicator of inflammatory responses of macrophages (THP-1) and of subtle phenotypic damages of lung epithelial (A549) cells following exposure to chemically-treated SWCNTs. Our results showed that, while most of the cellular responses of A549 cells exposed to SWCNTs are different to those of similarly treated THP-1 cells, the protein citrullination process is triggered in a dose- and time-dependent manner in both cell lines, with thresholds comparable between inflammatory (THP-1) and non-inflammatory (A549) cell types. The cellular mechanism proposed herein could have a high impact in predicting the current risk associated with environmental exposure to SWCNTs.

  6. Dual immunofluorescence study of citrullinated proteins in Parkinson diseased substantia nigra.

    PubMed

    Nicholas, Anthony P

    2011-05-09

    Deimination is a post-translational modification of proteins in which selected arginine amino acids are enzymatically converted to citrullines. Using dual-color immunofluorescence and an established monoclonal antibody (F95) against peptidyl-citrulline moieties, the present study is the first to compare immunohistochemical staining patterns for deiminated proteins in human substantia nigra (SN) from patients with Parkinson disease (PD) versus similar control specimens supplied by the Harvard Brain Bank. In control SN sections, many tyrosine hydroxylase (TH)-immunoreactive dopamine neurons were seen surrounded either by small fibers immunoreactive for deiminated proteins, or large reactive astrocytes, co-localized with glial fibrillary acidic protein (GFAP). However, in SN specimens from PD patients, immunoreactivity for deiminated proteins was also demonstrated within the cytoplasm of many surviving dopamine neurons that were also immunoreactive for TH, but this staining was not specifically restricted to Lewy bodies. Although the identity of neuronal deiminated proteins in these SN dopamine neurons is unknown, the present study provides evidence that the anatomical expression of these proteins in PD is altered and thus suggests that deimination may be involved in the pathophysiology of this disease. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. The use of citrullinated peptides and proteins for the diagnosis of rheumatoid arthritis

    PubMed Central

    2010-01-01

    The presence or absence of antibodies to citrullinated peptides/proteins (ACPA) is an important parameter that helps a clinician set a diagnosis of early rheumatoid arthritis and, hence, initiate treatment. There are several commercial tests available to measure ACPA levels, although it can be difficult to decide what the best test for a given clinical question is. We analyzed literature data in which the diagnostic and other properties of various ACPA tests are compared. The results show that for diagnostic purposes the CCP2 test has the highest specificity, the highest sensitivity in stratified studies and the highest positive predictive value. For the prediction of future joint destruction the CCP2, MCV, and CCP3 tests may be used. The ability to predict the likelihood of not achieving sustained disease-modifying antirheumatic drug-free remission was highest for the CCP2 test. Finally, the levels of anti-CCP2 and anti-CCP3 (and possibly anti-mutated citrullinated vimentin) in rheumatoid arthritis patients are not significantly influenced by TNFα blocking agents. PMID:20236483

  8. Citrullination as early-stage indicator of cell response to Single-Walled Carbon Nanotubes

    PubMed Central

    Mohamed, Bashir Mustafa; Movia, Dania; Knyazev, Anton; Langevin, Dominique; Davies, Anthony Mitchell; Prina-Mello, Adriele; Volkov, Yuri

    2013-01-01

    Single-walled carbon nanotubes (SWCNTs) have been widely explored as potential technologies for information systems and medical applications. The impact of SWCNTs on human health is of prime concern, if SWCNTs have a future in the manufacturing industry. This study proposes a novel, inflammation-independent paradigm of toxicity for SWCNTs, identifying the protein citrullination process as early-stage indicator of inflammatory responses of macrophages (THP-1) and of subtle phenotypic damages of lung epithelial (A549) cells following exposure to chemically-treated SWCNTs. Our results showed that, while most of the cellular responses of A549 cells exposed to SWCNTs are different to those of similarly treated THP-1 cells, the protein citrullination process is triggered in a dose- and time-dependent manner in both cell lines, with thresholds comparable between inflammatory (THP-1) and non-inflammatory (A549) cell types. The cellular mechanism proposed herein could have a high impact in predicting the current risk associated with environmental exposure to SWCNTs. PMID:23350031

  9. l-Citrulline ameliorates cerebral blood flow during cortical spreading depression in rats: Involvement of nitric oxide- and prostanoids-mediated pathway.

    PubMed

    Kurauchi, Yuki; Mokudai, Koichi; Mori, Asami; Sakamoto, Kenji; Nakahara, Tsutomu; Morita, Masahiko; Kamimura, Ayako; Ishii, Kunio

    2017-02-17

    l-Citrulline is a potent precursor of l-arginine, and exerts beneficial effect on cardiovascular system via nitric oxide (NO) production. Migraine is one of the most popular neurovascular disorder, and imbalance of cerebral blood flow (CBF) observed in cortical spreading depression (CSD) contributes to the mechanism of migraine aura. Here, we investigated the effect of l-citrulline on cardiovascular changes to KCl-induced CSD. in rats. Intravenous injection of l-citrulline prevented the decrease in CBF, monitored by laser Doppler flowmetry, without affecting mean arterial pressure and heart rate during CSD. Moreover, l-citrulline attenuated propagation velocity of CSD induced by KCl. The effect of l-citrulline on CBF change was prevented by l-NAME, an inhibitor of NO synthase, but not by indomethacin, an inhibitor of cyclooxygenase. On the other hand, attenuation effect of l-citrulline on CSD propagation velocity was prevented not only by l-NAME but also by indomethacin. In addition, propagation velocity of CSD was attenuated by intravenous injection of NOR3, a NO donor, which was diminished by ODQ, an inhibitor of soluble guanylyl cyclase. These results suggest that NO/cyclic GMP- and prostanoids-mediated pathway differently contribute to the effect of l-citrulline on the maintenance of CBF.

  10. Oral L-citrulline supplementation enhances cycling time trial performance in healthy trained men: Double-blind randomized placebo-controlled 2-way crossover study.

    PubMed

    Suzuki, Takashi; Morita, Masahiko; Kobayashi, Yoshinori; Kamimura, Ayako

    2016-01-01

    Many human studies report that nitric oxide (NO) improves sport performance. This is because NO is a potential modulator of blood flow, muscle energy metabolism, and mitochondrial respiration during exercise. L-Citrulline is an amino acid present in the body and is a potent endogenous precursor of L-arginine, which is a substrate for NO synthase. Here, we investigated the effect of oral L-citrulline supplementation on cycling time trial performance in humans. A double-blind randomized placebo-controlled 2-way crossover study was employed. Twenty-two trained males consumed 2.4 g/day of L-citrulline or placebo orally for 7 days. On Day 8 they took 2.4 g of L-citrulline or placebo 1 h before a 4-km cycling time trial. Time taken to complete the 4 km cycle, along with power output/VO2 ratio (PO/VO2), plasma nitrite and nitrate (NOx) and amino acid levels, and visual analog scale (VAS) scores, was evaluated. L-Citrulline supplementation significantly increased plasma L-arginine levels and reduced completion time by 1.5 % (p < 0.05) compared with placebo. Moreover, L-citrulline significantly improved subjective feelings of muscle fatigue and concentration immediately after exercise. Oral L-citrulline supplementation reduced the time take to complete a cycle ergometer exercise trial. Current Controlled Trials UMIN000014278.

  11. The purified and reconstituted ornithine/citrulline carrier from rat liver mitochondria: electrical nature and coupling of the exchange reaction with H+ translocation.

    PubMed Central

    Indiveri, C; Tonazzi, A; Stipani, I; Palmieri, F

    1997-01-01

    The mechanism and the electrical nature of ornithine/citrulline exchange has been investigated in proteoliposomes reconstituted with the ornithine/citrulline carrier purified from rat liver mitochondria. The stoichiometry of the exchanging substrates was close to 1:1. The exchange was not affected by inducing electrogenic flux of K+ with valinomycin. In contrast, the pH gradient generated by the K+/H+ exchanger nigericin in the presence of an outwardly directed K+ gradient stimulated the ornithineout/citrullinein exchange, but not the ornithine/ornithine homoexchange. Experiments in which either the internal or the external pH was varied, while keeping constant the pH in the other compartment, indicated that maximal exchange rates are found at pH 6 in the compartment containing citrulline and at pH 8 in the compartment containing ornithine. Changes in fluorescence of the pH indicator pyranine, included inside the proteoliposomes, showed that the exchanges ornithineout/citrullinein and citrullineout/ornithinein are accompanied by translocation of H+ in the same direction as citrulline. It is concluded that the mitochondrial ornithine/citrulline carrier catalyses an electroneutral exchange of ornithine+ for citrulline plus an H+. A reasonable model is one in which ornithine binds to a deprotonated carrier and citrulline to a protonated carrier and both substrate-carrier complexes are neutral. The physiological implications of this transport process are discussed. PMID:9359400

  12. Enzymatic production of l-citrulline by hydrolysis of the guanidinium group of l-arginine with recombinant arginine deiminase.

    PubMed

    Song, Wei; Sun, Xia; Chen, Xiulai; Liu, Dongxu; Liu, Liming

    2015-08-20

    In this study, a simple, efficient enzymatic production process for the environmentally friendly synthesis of l-citrulline from l-arginine was developed using arginine deiminase (ADI) from Lactococcus lactis. Following overexpression of L. lactis ADI in Escherichia. coli BL21 (DE3) and experimental evolution using error-prone PCR, mutant FMME106 was obtained with a Km for l-arginine of 3.5mM and a specific activity of 195.7U/mg. This mutant exhibited a maximal conversion of 92.6% and achieved a final l-citrulline concentration of 176.9g/L under optimal conditions (190g/L l-arginine, 15g/L whole-cell biocatalyst treated with 2% isopropanol for 30min, 50°C, pH 7.2, 8h). The average l-citrulline synthesis rate of 22.1g/L/h is considerably higher than that reported for other similar biocatalytic approaches, therefore the process developed in the present work has great potential for large-scale production of l-citrulline.

  13. Detection of Viral Citrullinated Peptide Antibodies Directed Against EBV or VCP: In Early Rheumatoid Arthritis Patients of Indian Origin

    PubMed Central

    Deo, Sudha S; Shetty, Rashmi R; Mistry, Kejal J; Chogle, Arun R

    2010-01-01

    Aim: Study was undertaken to analyze the frequency of anti-viral citrullinated peptide (anti-VCP) antibodies in sera from patients with early rheumatoid arthritis (ERA). Materials and Methods: Viral citrullinated peptide (VCP) and Epstein-Barr nuclear antigen (EBNA-1) peptide were commercially prepared and antibodies to these were determined in 25 patients of ERA, 40 disease control patients constituting 25 rheumatoid arthritis (RA), 7 systemic lupus erythematosus (SLE), 2 scleroderma, 1 spondyloarthritis (SpA), 1 juvenile rheumatoid arthritis (JRA), 1 osteoarthritis (OA), 1 psoriatic arthritis (PsA), 1 undifferentiated arthritis (UA), and 1 gout and 25 healthy controls (HCs) were taken for comparison. In-house ELISA was established for both the antibodies while cyclic citrullinated peptide (CCP) antibody was detected by commercial ELISA kit. Results: Significant increase in VCP antibody by ERA and disease controls than healthy normal was observed. VCP IgM antibody was significantly increased in RA patients than HC. The presence of VCP antibody signifies a good marker for ERA. We observed significant difference in the VCP IgG and IgM antibody when compared to EBNA-1. In-house ELISA established for EBNA-1 and VCP antibodies showed low sensitivity but 96% specificity. Conclusions: We observed that sera from early RA patients reacted to the deiminated protein encoded by Epstain Barr Virus (EBV). Thus a possible role of virus in inducing an anti-citrullinated peptide antibody (ACPA) response reveals viral etiology in this disease. PMID:21346905

  14. Anomalies of intra-synovial citrullination: is there any interest in the diagnosis of early rheumatoid arthritis?

    PubMed

    Mrabet, Dalila; Laadhar, Lilia; Haouet, Slim; Sahli, Héla; Zouari, Béchir; Makni, Sondès; Sellami, Slaheddine

    2013-03-01

    Autoantibodies to citrullinated proteins (ACPA) are specifically associated with rheumatoid arthritis (RA) and seem to play an important role in its pathogenesis. The specific immunological conflict between ACPA and citrullinated fibrin plays a major role in the self-maintenance of synovial inflammation by forming fibrin deposits in the synovial tissue. These deposits, secondarily citrullinated by a local peptidylarginine deiminase (PADI) enzyme activity, seem to maintain the immunological conflict and the inflammation. Our objective in this work is to study the anomalies of citrullination in a group of patients with early RA, in comparison with a control group of patients suffering from undetermined inflammatory arthritis, osteoarthritis and spondyloarthropathy. For this purpose, we used an enzyme-linked immunosorbent assay (ELISA) to determine the levels of ACPA in serum and synovial fluid. By immunohistochemistry, subtype 4 of PADI was also sought in the synovial biopsies taken from all our patients. We found that the ACPA levels in serum and synovial fluid were significantly higher in patients with RA. The enzyme PADI4 was found only in the group with RA and was statistically correlated with ACPA mean levels in sera and synovial fluid. The expression of PADI4 seems to correlate with intra-synovial deposits of fibrin in RA. However, determination of synovial ACPA levels and detection of intra-synovial PADI4 deposits are of no additional benefit compared with assessment of ACPA levels in serum for the diagnosis of early RA.

  15. Surface-enhanced Raman spectroscopy competitive binding biosensor development utilizing surface modification of silver nanocubes and a citrulline aptamer

    NASA Astrophysics Data System (ADS)

    Walton, Brian M.; Jackson, George W.; Deutz, Nicolaas; Cote, Gerard

    2017-07-01

    A point-of-care (PoC) device with the ability to detect biomarkers at low concentrations in bodily fluids would have an enormous potential for medical diagnostics outside the central laboratory. One method to monitor analytes at low concentrations is by using surface-enhanced Raman spectroscopy (SERS). In this preliminary study toward using SERS for PoC biosensing, the surface of colloidal silver (Ag) nanocubes has been modified to test the feasibility of a competitive binding SERS assay utilizing aptamers against citrulline. Specifically, Ag nanocubes were functionalized with mercaptobenzoic acid, as well as a heterobifunctional polyethylene glycol linker that forms an amide bond with the amino acid citrulline. After the functionalization, the nanocubes were characterized by zeta-potential, transmission electron microscopy images, ultraviolet/visible spectroscopy, and by SERS. The citrulline aptamers were developed and tested using backscattering interferometry. The data show that our surface modification method does work and that the functionalized nanoparticles can be detected using SERS down to a 24.5 picomolar level. Last, we used microscale thermophoresis to show that the aptamers bind to citrulline with at least a 50 times stronger affinity than other amino acids.

  16. l-Citrulline and l-arginine supplementation retards the progression of high-cholesterol-diet-induced atherosclerosis in rabbits.

    PubMed

    Hayashi, Toshio; Juliet, Packiasamy A R; Matsui-Hirai, Hisako; Miyazaki, Asaka; Fukatsu, Akiko; Funami, Jun; Iguchi, Akihisa; Ignarro, Louis J

    2005-09-20

    The objective of this study was to evaluate the influence of ingested l-arginine, l-citrulline, and antioxidants (vitamins C and E) on the progression of atherosclerosis in rabbits fed a high-cholesterol diet. The fatty diet caused a marked impairment of endothelium-dependent vasorelaxation in isolated thoracic aorta and blood flow in rabbit ear artery in vivo, the development of atheromatous lesions and increased superoxide anion production in thoracic aorta, and increased oxidation-sensitive gene expression [Elk-1 and phosphorylated cAMP response element-binding protein]. Rabbits were treated orally for 12 weeks with l-arginine, l-citrulline, and/or antioxidants. l-arginine plus l-citrulline, either alone or in combination with antioxidants, caused a marked improvement in endothelium-dependent vasorelaxation and blood flow, dramatic regression in atheromatous lesions, and decrease in superoxide production and oxidation-sensitive gene expression. These therapeutic effects were associated with concomitant increases in aortic endothelial NO synthase expression and plasma NO(2)(-)+NO(3)(-) and cGMP levels. These observations indicate that ingestion of certain NO-boosting substances, including l-arginine, l-citrulline, and antioxidants, can abrogate the state of oxidative stress and reverse the progression of atherosclerosis. This approach may have clinical utility in the treatment of atherosclerosis in humans.

  17. Differing specificities and isotypes of anti-citrullinated peptide/protein antibodies in palindromic rheumatism and rheumatoid arthritis.

    PubMed

    Cabrera-Villalba, Sonia; Gomara, María José; Cañete, Juan D; Ramírez, Julio; Salvador, Georgina; Ruiz-Esquide, Virginia; Hernández, Maria Victoria; Inciarte-Mundo, José; Haro, Isabel; Sanmartí, Raimon

    2017-06-15

    To analyze differences in the recognition of anti-citrullinated peptide/protein antibody (ACPA) citrullinated epitopes and isotypes in patients with palindromic rheumatism (PR) and rheumatoid arthritis (RA). ACPA fine specificities (citrullinated peptides of enolase, fibrin, and vimentin) and isotypes (IgG, IgM, and IgA) were analyzed in 54 patients with longstanding PR and 54 patients with established RA. CCP2 tested positive in 66.7% of patients with PR and RA. The ACPA distribution of fine specificities and isotypes differed between PR and RA patients. PR patients had a lower frequency of fine ACPA specificities than RA patients, which was significant in the case of a peptide derived from vimentin (PR 24.1% vs. 59.3% RA; p < 0.001). The mean number of ACPA specificities was lower in PR than in RA patients, and only 25.9% of PR patients recognized ≥2 additional specificities compared with 46.3% of RA patients. Significantly less isotype usage, especially IgA, was observed in PR patients. The ACPA immune response differed in patients with PR and RA, with fewer fine specificities and isotype usage in patients with PR. Some patients with PR may have impaired maturation of the B-cell response against citrullinated peptides with no progression to RA.

  18. Stimulation by D-glucose of the direct conversion of arginine to citrulline in enterocytes isolated from pig jejunum

    SciTech Connect

    Blachier, F.; M'Rabet-Touil, H.; Darcy-Vrillon, B.; Posho, L.; Duee, P.H. )

    1991-06-28

    In enterocytes isolated from pig jejunum, L-arginine is metabolized to L-citrulline either directly or indirectly through the sequence of reactions catalysed by arginase and ornithine transcarbamylase. In the presence of 5 mM D-glucose, the direct conversion of 1mM L-(guanido-14C) arginine to L-citrulline was increased more than 4 times. Isolated enterocytes exhibit a high glycolytic capacity. Furthermore, the decarboxylation of 5mM D-(1-14C) glucose was 3.6 fold higher than the decarboxylation of 5 mM D-(6-14C) glucose which suggests the presence of a pentose phosphate pathway in enterocytes. Since the production of labelled L-citrulline from L-(guanido-14C) arginine in pig enterocyte homogenates was markedly increased in the presence of NADPH, it is proposed that the direct conversion of L-arginine to L-citrulline could be stimulated by the production of NADPH from D-glucose in the pentose phosphate pathway.

  19. Plasma arginine and ornithine are the main citrulline precursors in mice infused with arginine-free diets

    USDA-ARS?s Scientific Manuscript database

    Dietary arginine is the main dietary precursor for citrulline synthesis, but it is not known if other precursors can compensate for when arginine is absent in the diet. To address this question, the contribution of plasma and dietary precursors were determined, utilizing multitracer protocols in con...

  20. Citrulline stimulates muscle protein synthesis in the post-absorptive state in healthy people fed a low-protein diet – A pilot study

    PubMed Central

    Jourdan, Marion; Nair, K. Sreekumaran; Carter, Rickey E.; Schimke, Jill; Ford, G. Charles; Marc, Julie; Aussel, Christian; Cynober, Luc

    2015-01-01

    Background and Aims Amino acid (AA) availability is critical to maintain protein homeostasis and reduced protein intake causes a decline in protein synthesis. Citrulline, an amino acid metabolite, has been reported to stimulate muscle protein synthesis in malnourished rats. Methods To determine whether citrulline stimulates muscle protein synthesis in healthy adults while on a low-protein diet, we studied 8 healthy participants twice in a cross-over study design. Following a 3-days of low-protein intake, either citrulline or a non-essential AA mixture (NEAA) was given orally as small boluses over the course of 8 hours. [ring-13C6] phenylalanine and [15N] tyrosine were administered as tracers to assess protein metabolism. Fractional synthesis rates (FSR) of muscle proteins were measured using phenylalanine enrichment in muscle tissue fluid as the precursor pool. Results FSR of mixed muscle protein was higher during the administration of citrulline than during NEAA (NEAA: 0.049 ± 0.005; citrulline: 0.060 ± 0.006; p=0.03), while muscle mitochondrial protein FSR and whole-body protein turnover were not different between the studies. Citrulline administration increased arginine and ornithine plasma concentrations without any effect on glucose, insulin, C-peptide, and IGF-1 levels. Citrulline administration did not promote mitochondria protein synthesis, transcripts, or citrate synthesis. Conclusions Citrulline ingestion enhances mixed muscle protein synthesis in healthy participants on 3-day low-protein intake. This anabolic action of citrulline appears to be independent of insulin action and may offer potential clinical application in conditions involving low amino acid intake. PMID:24972455

  1. Citrulline stimulates muscle protein synthesis in the post-absorptive state in healthy people fed a low-protein diet - A pilot study.

    PubMed

    Jourdan, Marion; Nair, K Sreekumaran; Carter, Rickey E; Schimke, Jill; Ford, G Charles; Marc, Julie; Aussel, Christian; Cynober, Luc

    2015-06-01

    Amino acid (AA) availability is critical to maintain protein homeostasis and reduced protein intake causes a decline in protein synthesis. Citrulline, an amino acid metabolite, has been reported to stimulate muscle protein synthesis in malnourished rats. To determine whether citrulline stimulates muscle protein synthesis in healthy adults while on a low-protein diet, we studied 8 healthy participants twice in a cross-over study design. Following a 3-days of low-protein intake, either citrulline or a non-essential AA mixture (NEAA) was given orally as small boluses over the course of 8 h. [ring-(13)C6] phenylalanine and [(15)N] tyrosine were administered as tracers to assess protein metabolism. Fractional synthesis rates (FSR) of muscle proteins were measured using phenylalanine enrichment in muscle tissue fluid as the precursor pool. FSR of mixed muscle protein was higher during the administration of citrulline than during NEAA (NEAA: 0.049 ± 0.005; citrulline: 0.060 ± 0.006; P = 0.03), while muscle mitochondrial protein FSR and whole-body protein turnover were not different between the studies. Citrulline administration increased arginine and ornithine plasma concentrations without any effect on glucose, insulin, C-peptide, and IGF-1 levels. Citrulline administration did not promote mitochondria protein synthesis, transcripts, or citrate synthesis. Citrulline ingestion enhances mixed muscle protein synthesis in healthy participants on 3-day low-protein intake. This anabolic action of citrulline appears to be independent of insulin action and may offer potential clinical application in conditions involving low amino acid intake. Copyright © 2014. Published by Elsevier Ltd.

  2. Impact of L-citrulline supplementation and whole-body vibration training on arterial stiffness and leg muscle function in obese postmenopausal women with high blood pressure.

    PubMed

    Figueroa, Arturo; Alvarez-Alvarado, Stacey; Ormsbee, Michael J; Madzima, Takudzwa A; Campbell, Jeremiah C; Wong, Alexei

    2015-03-01

    Aging is associated with increased arterial stiffness (pulse wave velocity, PWV) and muscle strength/mass loss. Exercise training alone is not always effective to improve PWV and lean mass (LM) in older women. To investigate the independent and combined effects of whole-body vibration training (WBVT) and L-citrulline supplementation on PWV and muscle function in women, forty-one postmenopausal women aged 58 ± 3 years and body mass index (34 ± 2 kg/m(2)) were randomly assigned to the following groups: WBVT, L-citrulline, and WBVT + L-citrulline for 8 weeks. WBVT consisted of four leg exercises three times weekly. Aortic (cfPWV) and leg (faPWV) PWV, leg LM index, leg strength, and body fat percentage (BF%) were measured before and after the interventions. WBVT + L-citrulline decreased cfPWV (-0.91 ± 0.21 m/s, P < 0.01) compared to both groups. All interventions decreased faPWV (P < 0.05) similarly. Leg LM index increased (2.7 ± 0.5%, P < 0.001) after WBVT + L-citrulline compared with L-citrulline. Both WBVT interventions increased leg strength (~37%, P < 0.001) compared to L-citrulline while decreased BF% (~2.0%, P < 0.01). Reductions in cfPWV were correlated with increases in leg LM index (r = -0.63, P < 0.05). Our findings suggest that leg muscle strength and arterial stiffness can be improved after WBVT, but its combination with L-citrulline supplementation enhanced benefits on aortic stiffness and leg LM. Therefore, WBVT + L-citrulline could be an intervention for improving arterial stiffness and leg muscle function in obese postmenopausal women with prehypertension or hypertension, thereby reducing their cardiovascular and disability risk. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. [Plasma citrulline concentration as a biomarker of intestinal function in short bowel syndrome and in intestinal transplant].

    PubMed

    Vecino López, R; Andrés Moreno, A M; Ramos Boluda, E; Martinez-Ojinaga Nodal, E; Hernanz Macías, A; Prieto Bozano, G; Lopez Santamaria, M; Tovar Larrucea, J A

    2013-10-01

    Citrulline is a non-essential amino acid produced solely in the enterocyte. The aim of this study was to analyse the role of serum citrulline as a biomarker of enterocyte load in children with intestinal failure due to short bowel syndrome (SBS) and its relationship to enteral adaptation. Plasma citrulline concentration was determined by chromatography (normal value>15 μmol/L) in 57 patients (age 0.5-18 years) admitted to our Intestinal Rehabilitation Unit with intestinal failure. Those who were dehydrated, with renal insufficiency, or other conditions able to modify the results were excluded. Patients were divided into 4 groups: group i: SBS totally dependent on parenteral nutrition (PN); group ii: SBS under mixed enteral-parenteral nutrition; group iii: IF weaned from PN after a rehabilitation period; group iv: small bowel transplanted patients weaned from PN and taking a normal diet. The mean ± SD plasma citrulline values were: group i (n=15): 7.1 ± 4.1; group ii (n=11): 15.8 ± 8.9; group iii (n=13): 20.6 ± 7.5; group iv (n=25): 28.8 ± 10.1. Values were significantly lower in group i in comparison with groups ii-iii-iv (P<.001), and in group ii in comparison with groups iii-iv (P<.001). A low citrulline was associated with remnant small bowel length (P<.001, r=0.85). In group iv citrulline levels decreased >50% in 3 patients who developed moderate-severe rejection, and in one patient who developed viral enteritis. 1. Plasma citrulline could be a sensitive and specific biomarker of the residual functional enterocyte load. 2. It is related to enteral feeding tolerance. 3. Its prognostic value in the process of intestinal adaptation and as a rejection marker in small bowel transplanted patients needs to be confirmed. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  4. Apo AIV and Citrulline Plasma Concentrations in Short Bowel Syndrome Patients: The Influence of Short Bowel Anatomy

    PubMed Central

    Targarona, Jordi; Ruiz, Jorge; García, Natalia; Oró, Denise; García-Villoria, Judit; Creus, Gloria; Pita, Ana M.

    2016-01-01

    Introduction Parenteral nutrition (PN) dependence in short bowel syndrome (SBS) patients is linked to the functionality of the remnant small bowel (RSB). Patients may wean off PN following a period of intestinal adaptation that restores this functionality. Currently, plasma citrulline is the standard biomarker for monitoring intestinal functionality and adaptation. However, available studies reveal that the relationship the biomarker with the length and function of the RSB is arguable. Thus, having additional biomarkers would improve pointing out PN weaning. Aim By measuring concomitant changes in citrulline and the novel biomarker apolipoprotein AIV (Apo AIV), as well as taking into account the anatomy of the RSB, this exploratory study aims to a better understanding of the intestinal adaptation process and characterization of the SBS patients under PN. Methods Thirty four adult SBS patients were selected and assigned to adapted (aSBS) and non-adapted (nSBS) groups after reconstructive surgeries. Remaining jejunum and ileum lengths were recorded. The aSBS patients were either on an oral diet (ORAL group), those with intestinal insufficiency, or on oral and home parenteral nutrition (HPN group), those with chronic intestinal failure. Apo AIV and citrulline were analyzed in plasma samples after overnight fasting. An exploratory ROC analysis using citrulline as gold standard was performed. Results Biomarkers, Apo AIV and citrulline showed a significant correlation with RSBL in aSBS patients. In jejuno-ileocolic patients, only Apo AIV correlated with RSBL (rb = 0.54) and with ileum length (rb = 0.84). In patients without ileum neither biomarker showed any correlation with RSBL. ROC analysis indicated the Apo AIV cut-off value to be 4.6 mg /100 mL for differentiating between the aSBS HPN and ORAL groups. Conclusions Therefore, in addition to citrulline, Apo AIV can be set as a biomarker to monitor intestinal adaptation in SBS patients. As short bowel anatomy is shown

  5. Apo AIV and Citrulline Plasma Concentrations in Short Bowel Syndrome Patients: The Influence of Short Bowel Anatomy.

    PubMed

    López-Tejero, M Dolores; Virgili, Núria; Targarona, Jordi; Ruiz, Jorge; García, Natalia; Oró, Denise; García-Villoria, Judit; Creus, Gloria; Pita, Ana M

    Parenteral nutrition (PN) dependence in short bowel syndrome (SBS) patients is linked to the functionality of the remnant small bowel (RSB). Patients may wean off PN following a period of intestinal adaptation that restores this functionality. Currently, plasma citrulline is the standard biomarker for monitoring intestinal functionality and adaptation. However, available studies reveal that the relationship the biomarker with the length and function of the RSB is arguable. Thus, having additional biomarkers would improve pointing out PN weaning. By measuring concomitant changes in citrulline and the novel biomarker apolipoprotein AIV (Apo AIV), as well as taking into account the anatomy of the RSB, this exploratory study aims to a better understanding of the intestinal adaptation process and characterization of the SBS patients under PN. Thirty four adult SBS patients were selected and assigned to adapted (aSBS) and non-adapted (nSBS) groups after reconstructive surgeries. Remaining jejunum and ileum lengths were recorded. The aSBS patients were either on an oral diet (ORAL group), those with intestinal insufficiency, or on oral and home parenteral nutrition (HPN group), those with chronic intestinal failure. Apo AIV and citrulline were analyzed in plasma samples after overnight fasting. An exploratory ROC analysis using citrulline as gold standard was performed. Biomarkers, Apo AIV and citrulline showed a significant correlation with RSBL in aSBS patients. In jejuno-ileocolic patients, only Apo AIV correlated with RSBL (rb = 0.54) and with ileum length (rb = 0.84). In patients without ileum neither biomarker showed any correlation with RSBL. ROC analysis indicated the Apo AIV cut-off value to be 4.6 mg /100 mL for differentiating between the aSBS HPN and ORAL groups. Therefore, in addition to citrulline, Apo AIV can be set as a biomarker to monitor intestinal adaptation in SBS patients. As short bowel anatomy is shown to influence citrulline and Apo AIV plasma

  6. Immune Recognition of Citrullinated Proteoglycan Aggrecan Epitopes in Mice with Proteoglycan-Induced Arthritis and in Patients with Rheumatoid Arthritis

    PubMed Central

    Markovics, Adrienn; Ocskó, Tímea; Katz, Robert S.; Buzás, Edit I.; Glant, Tibor T.

    2016-01-01

    Background Rheumatoid arthritis (RA) is an autoimmune inflammatory disease affecting the joints. Anti-citrullinated protein antibodies (ACPA) are frequently found in RA. Previous studies identified a citrullinated epitope in cartilage proteoglycan (PG) aggrecan that elicited pro-inflammatory cytokine production by RA T cells. We recently reported the presence of ACPA-reactive (citrullinated) PG in RA cartilage. Herein, we sought to identify additional citrullinated epitopes in human PG that are recognized by T cells or antibodies from RA patients. Methods We used mice with PG-induced arthritis (PGIA) as a screening tool to select citrulline (Cit)-containing PG peptides that were more immunogenic than the arginine (R)-containing counterparts. The selected peptide pairs were tested for induction of pro-inflammatory T-cell cytokine production in RA and healthy control peripheral blood mononuclear cell (PBMC) cultures using ELISA and flow cytometry. Anti-Cit and anti-R peptide antibodies were detected by ELISA. Results Splenocytes from mice with PGIA exhibited greater T-cell cytokine secretion in response to the Cit than the R version of PG peptide 49 (P49) and anti-P49 antibodies were found in PGIA serum. PBMC from ACPA+ and ACPA- RA patients, but not from healthy controls, responded to Cit49 with robust cytokine production. High levels of anti-Cit49 antibodies were found in the plasma of a subset of ACPA+ RA patients. Another PG peptide (Cit13) similar to the previously described T-cell epitope induced greater cytokine responses than R13 by control (but not RA) PBMC, however, anti-Cit13 antibodies were rarely detected in human plasma. Conclusions We identified a novel citrullinated PG epitope (Cit49) that is highly immunogenic in mice with PGIA and in RA patients. We also describe T-cell and antibody reactivity with Cit49 in ACPA+ RA. As citrullinated PG might be present in RA articular cartilage, Cit PG epitope-induced T-cell activation or antibody deposition may

  7. The Supplementation of Branched-Chain Amino Acids, Arginine, and Citrulline Improves Endurance Exercise Performance in Two Consecutive Days

    PubMed Central

    Cheng, I-Shiung; Wang, Yi-Wen; Chen, I-Fan; Hsu, Gi-Sheng; Hsueh, Chun-Fang; Chang, Chen-Kang

    2016-01-01

    The central nervous system plays a crucial role in fatigue during endurance exercise. Branched-chain amino acids (BCAA) could reduce cerebral serotonin synthesis by competing with its precursor tryptophan for crossing the blood brain barrier. Arginine and citrulline could prevent excess hyperammonemia accompanied by BCAA supplementation. This study investigated the combination of BCAA, arginine, and citrulline on endurance performance in two consecutive days. Seven male and three female endurance runners ingested 0.17 g·kg-1 BCAA, 0.05 g·kg-1 arginine and 0.05 g·kg-1 citrulline (AA trial) or placebo (PL trial) in a randomized cross-over design. Each trial contained a 5000 m time trial on the first day, and a 10000 m time trial on the second day. The AA trial had significantly better performance in 5000 m (AA: 1065.7 ± 33.9 s; PL: 1100.5 ± 40.4 s) and 10000 m (AA: 2292.0 ± 211.3 s; PL: 2375.6 ± 244.2 s). The two trials reported similar ratings of perceived exertion. After exercise, the AA trial had significantly lower tryptophan/BCAA ratio, similar NH3, and significantly higher urea concentrations. In conclusion, the supplementation could enhance time-trial performance in two consecutive days in endurance runners, possibly through the inhibition of cerebral serotonin synthesis by BCAA and the prevention of excess hyperammonemia by increased urea genesis. Key points The combined supplementation of BCAA, arginine, and citrulline could enhance performance in 5000 m and 10000 m in 2 consecutive days in competitive runners. The supplementation may be helpful in multi-day competitions. The supplemented BCAA may alleviate central fatigue, allowing the subjects to run faster at the same degree of perceived exertion. The hyperammonemia that is usually accompanied with BCAA supplementation may be prevented by arginine and citrulline through increased urea genesis. PMID:27803630

  8. Contribution of citrulline ureidase to Francisella tularensis strain Schu S4 pathogenesis.

    PubMed

    Mahawar, Manish; Kirimanjeswara, Girish S; Metzger, Dennis W; Bakshi, Chandra Shekhar

    2009-08-01

    The citrulline ureidase (CTU) activity has been shown to be associated with highly virulent Francisella tularensis strains, including Schu S4, while it is absent in avirulent or less virulent strains. A definitive role of the ctu gene in virulence and pathogenesis of F. tularensis Schu S4 has not been assessed; thus, an understanding of the significance of this phenotype is long overdue. CTU is a carbon-nitrogen hydrolase encoded by the citrulline ureidase (ctu) gene (FTT0435) on the F. tularensis Schu S4 genome. In the present study, we evaluated the contribution of the ctu gene in the virulence of category A agent F. tularensis Schu S4 by generating a nonpolar deletion mutant, the Deltactu mutant. The deletion of the ctu gene resulted in loss of CTU activity, which was restored by transcomplementing the ctu gene. The Deltactu mutant did not exhibit any growth defect under acellular growth conditions; however, it was impaired for intramacrophage growth in resting as well as gamma interferon-stimulated macrophages. The Deltactu mutant was further tested for its virulence attributes in a mouse model of respiratory tularemia. Mice infected intranasally with the Deltactu mutant showed significantly reduced bacterial burden in the lungs, liver, and spleen compared to wild-type (WT) Schu S4-infected mice. The reduced bacterial burden in mice infected with the Deltactu mutant was also associated with significantly lower histopathological scores in the lungs. Mice infected with the Deltactu mutant succumbed to infection, but they survived longer and showed significantly extended median time to death compared to that shown by WT Schu S4-infected mice. To conclude, this study demonstrates that ctu contributes to intracellular survival, in vivo growth, and pathogenesis. However, ctu is not an absolute requirement for the virulence of F. tularensis Schu S4 in mice.

  9. Independence of carbohydrate-deficient isoforms of transferrin and cyclic citrullinated peptides in rheumatoid arthritis.

    PubMed

    Gudowska, Monika; Gindzienska-Sieskiewicz, Ewa; Gruszewska, Ewa; Cylwik, Bogdan; Sierakowski, Stanislaw; Szmitkowski, Maciej; Chrostek, Lech

    2016-03-03

    The aim of this study was to assess the relationship between the two types of posttranslational modifications of proteins in RA: glycosylation on the example of carbohydrate-deficient transferrin (CDT) and citrullination by means of autoantibodies to cyclic citrullinated peptides (anti-CCP). The study was carried out in 50 RA patients. CDT was measured using N Latex CDT immunonephelometric test, the results were presented in absolute and relative units. Anti-CCP were measured using the chemiluminescent method and rheumatoid factor (RF) by immunoturbidimetric method. 80% of RA patients were positive for anti-CCP, 70% for RF and 62% for both, anti-CCP and RF. The level of %CDT was significantly elevated, but absolute CDT level was not changed. The mean absolute CDT concentration was higher in anti-CCP positive patients than that in anti-CCP negative. CDT (absolute and relative concentration) did not correlate with anti-CCP and RF. However, serum RF significantly correlated with anti-CCP. %CDT did not correlate with anti-CCP, but absolute level correlated with anti-CCP only in anti-CCP negative and RF negative patients. CDT did not correlate with RF, but solely with anti-CCP in anti-CCP negative patients. Anti-CCP correlated with DAS 28 only in anti-CCP negative RA, but CDT (absolute and relative units) correlated with DAS 28 in all patients and in anti-CCP positive RA. These results suggest that the changes in CDT and anti-CCP concentrations are not associated with oneself and indicate on the independence of these posttranslational modifications in rheumatoid arthritis. Only the alterations in transferrin glycosylation reflected the activity of RA. Copyright © 2016 Elsevier Editora Ltda. All rights reserved.

  10. Independence of carbohydrate-deficient isoforms of transferrin and cyclic citrullinated peptides in rheumatoid arthritis.

    PubMed

    Gudowska, Monika; Gindzienska-Sieskiewicz, Ewa; Gruszewska, Ewa; Cylwik, Bogdan; Sierakowski, Stanislaw; Szmitkowski, Maciej; Chrostek, Lech

    The aim of this study was to assess the relationship between the two types of posttranslational modifications of proteins in RA: glycosylation on the example of carbohydrate-deficient transferrin and citrullination by means of autoantibodies to cyclic citrullinated peptides. The study was carried out in 50 RA patients. CDT was measured using N Latex CDT immunonephelometric test, the results were presented in absolute and relative units. Anti-CCP were measured using the chemiluminescent method and rheumatoid factor by immunoturbidimetric method. 80% of RA patients were positive for anti-CCP, 70% for RF and 62% for both, anti-CCP and RF. The level of %CDT was significantly elevated, but absolute CDT level was not changed. The mean absolute CDT concentration was higher in anti-CCP positive patients than that in anti-CCP negative. CDT (absolute and relative concentration) did not correlate with anti-CCP and RF. However, serum RF significantly correlated with anti-CCP. %CDT did not correlate with anti-CCP, but absolute level correlated with anti-CCP only in anti-CCP negative and RF negative patients. CDT did not correlate with RF, but solely with anti-CCP in anti-CCP negative patients. Anti-CCP correlated with DAS 28 only in anti-CCP negative RA, but CDT (absolute and relative units) correlated with DAS 28 in all patients and in anti-CCP positive RA. These results suggest that the changes in CDT and anti-CCP concentrations are not associated with oneself and indicate on the independence of these posttranslational modifications in rheumatoid arthritis. Only the alterations in transferrin glycosylation reflected the activity of RA. Copyright © 2016 Elsevier Editora Ltda. All rights reserved.

  11. DL-7-azatryptophan and citrulline metabolism in the cyanobacterium Anabaena sp. strain 1F.

    PubMed Central

    Chen, C H; Van Baalen, C; Tabita, F R

    1987-01-01

    An alternative route for the primary assimilation of ammonia proceeds via glutamine synthetase-carbamyl phosphate synthetase and its inherent glutaminase activity in Anabaena sp. strain 1F, a marine filamentous, heterocystous cyanobacterium. Evidence for the presence of this possible alternative route to glutamate was provided by the use of amino acid analogs as specific enzyme inhibitors, enzymological studies, and radioistopic labeling experiments. The amino acid pool patterns of continuous cultures of Anabaena sp. strain 1F were markedly influenced by the nitrogen source. A relatively high concentration of glutamate was maintained in the amino acid pools of all cultures irrespective of the nitrogen source, reflecting the central role of glutamate in nitrogen metabolism. The addition of 1.0 microM azaserine increased the intracellular pools of glutamate and glutamine. All attempts to detect any enzymatic activity for glutamate synthase by measuring the formation of L-[14C]glutamate from 2-keto-[1-14C]glutarate and glutamine failed. The addition of 10 microM DL-7-azatryptophan caused a transient accumulation of intracellular citrulline and alanine which was not affected by the presence of chloramphenicol. The in vitro activity of carbamyl phosphate synthetase and glutaminase increased severalfold in the presence of azatryptophan. Results from radioisotopic labeling experiments with [14C]bicarbonate and L-[1-14C]ornithine also indicated that citrulline was formed via carbamyl phosphate synthetase and ornithine transcarbamylase. In addition to its effects on nitrogen metabolism, azatryptophan also affected carbon metabolism by inhibiting photosynthetic carbon assimilation and photosynthetic oxygen evolution. Images PMID:2880834

  12. Effect of Teduglutide, a Glucagon-like Peptide 2 Analog, on Citrulline Levels in Patients With Short Bowel Syndrome in Two Phase III Randomized Trials

    PubMed Central

    Seidner, Douglas L; Joly, Francisca; Youssef, Nader N

    2015-01-01

    Objectives: In clinical trials, treatment with the glucagon-like peptide 2 analog teduglutide was associated with improved fluid and nutrient absorption and increased intestinal villus height and crypt depth in patients with short bowel syndrome (SBS). Plasma citrulline, an amino acid produced by enterocytes, is considered a measure of enterocyte mass. This analysis assessed changes in plasma citrulline levels in patients with SBS in 2 phase III clinical studies of teduglutide. Methods: Both teduglutide studies (0.05 or 0.10 mg/kg/day in CL0600-004 and 0.05 mg/kg/day in CL0600-020) were phase III, 24-week, double-blind, and placebo controlled. Plasma citrulline levels were analyzed and validated by liquid chromatography coupled to tandem mass spectrometry. Results: In both the CL0600-004 and CL0600-020 studies, change in mean plasma citrulline concentrations at Week 24 vs. baseline was significantly greater with teduglutide compared with placebo (10.9 (0.05-mg/kg/day dose) and 15.7 (0.10-mg/kg/day dose) vs. 2.0 μmol/L and 20.6 vs. 0.7 μmol/L, respectively, for each study (P≤0.0001 for each comparison with placebo)). Teduglutide treatment was associated with reductions from baseline in PS (parenteral support) volume requirements; however, a significant correlation between PS reduction and increase in plasma citrulline at Week 24 was observed in only one out of the three teduglutide treatment groups. Conclusions: In 2 phase III studies, patients receiving teduglutide had significant increases in plasma citrulline at Week 24 compared with patients receiving placebo. Increases in plasma citrulline concentrations likely reflect enterocyte mass expansion, but no clear correlation was detected between change in plasma citrulline and change in weekly PS volume. PMID:26111125

  13. A putative transport protein is involved in citrulline excretion and re-uptake during arginine deiminase pathway activity by Lactobacillus sakei.

    PubMed

    Rimaux, Tom; Rivière, Audrey; Hebert, Elvira María; Mozzi, Fernanda; Weckx, Stefan; De Vuyst, Luc; Leroy, Frédéric

    2013-04-01

    Arginine conversion through the arginine deiminase (ADI) pathway is a common metabolic trait of Lactobacillus sakei which is ascribed to an arc operon and which inquisitively involves citrulline excretion and re-uptake. The aim of this study was to verify whether a putative transport protein (encoded by the PTP gene) plays a role in citrulline-into-ornithine conversion by L. sakei strains. This was achieved through a combination of fermentation experiments, gene expression analysis via quantitative real-time reverse transcription PCR (RT-qPCR) and construction of a PTP knock-out mutant. Expression of the PTP gene was modulated by environmental pH and was highest in the end-exponential or mid-exponential growth phase for L. sakei strains CTC 494 and 23K, respectively. In contrast to known genes of the arc operon, the PTP gene showed low expression at pH 7.0, in agreement with the finding that citrulline-into-ornithine conversion is inhibited at this pH. The presence of additional energy sources also influenced ADI pathway activity, in particular by decreasing citrulline-into-ornithine conversion. Further insight into the functionality of the PTP gene was obtained with a knock-out mutant of L. sakei CTC 494 impaired in the PTP gene, which displayed inhibition in its ability to convert extracellular citrulline into ornithine. In conclusion, results indicated that the PTP gene may putatively encode a citrulline/ornithine antiporter.

  14. Development and validation of a LC-MS/MS assay for quantitation of plasma citrulline for application to animal models of the acute radiation syndrome across multiple species.

    PubMed

    Jones, Jace W; Tudor, Gregory; Bennett, Alexander; Farese, Ann M; Moroni, Maria; Booth, Catherine; MacVittie, Thomas J; Kane, Maureen A

    2014-07-01

    The potential risk of a radiological catastrophe highlights the need for identifying and validating potential biomarkers that accurately predict radiation-induced organ damage. A key target organ that is acutely sensitive to the effects of irradiation is the gastrointestinal (GI) tract, referred to as the GI acute radiation syndrome (GI-ARS). Recently, citrulline has been identified as a potential circulating biomarker for radiation-induced GI damage. Prior to biologically validating citrulline as a biomarker for radiation-induced GI injury, there is the important task of developing and validating a quantitation assay for citrulline detection within the radiation animal models used for biomarker validation. Herein, we describe the analytical development and validation of citrulline detection using a liquid chromatography tandem mass spectrometry assay that incorporates stable-label isotope internal standards. Analytical validation for specificity, linearity, lower limit of quantitation, accuracy, intra- and interday precision, extraction recovery, matrix effects, and stability was performed under sample collection and storage conditions according to the Guidance for Industry, Bioanalytical Methods Validation issued by the US Food and Drug Administration. In addition, the method was biologically validated using plasma from well-characterized mouse, minipig, and nonhuman primate GI-ARS models. The results demonstrated that circulating citrulline can be confidently quantified from plasma. Additionally, circulating citrulline displayed a time-dependent response for radiological doses covering GI-ARS across multiple species.

  15. Environmental pH determines citrulline and ornithine release through the arginine deiminase pathway in Lactobacillus fermentum IMDO 130101.

    PubMed

    Vrancken, G; Rimaux, T; Weckx, S; De Vuyst, L; Leroy, F

    2009-11-15

    Sourdough lactic acid bacteria (LAB) need to be adapted to a highly acidic and, therefore, challenging environment. Different mechanisms are employed to enhance competitiveness, among which conversion of arginine into ornithine through the arginine deiminase (ADI) pathway is an important one. A combined molecular and kinetic approach of the ADI pathway in Lactobacillus fermentum IMDO 130101, a highly competitive sourdough LAB strain, identified mechanisms with advantageous technological effects and quantified the impact of these effects. First, molecular analysis of the arcBCAD operon of 4.8 kb revealed the genes encoding the enzymes ornithine transcarbamoylase, carbamate kinase, arginine deiminase, and an arginine/ornithine (A/O) antiporter, respectively, with an additional A/O antiporter 702.5 kb downstream of the ADI operon. The latter could play a role in citrulline transport. Second, pH-controlled batch fermentations were carried out, generating data for the development of a mathematical model to describe the temporal evolution of the three amino acids involved in the ADI pathway (arginine, citrulline, and ornithine) as a result of the activity of these enzymes and transporter(s). Free arginine in the medium was converted completely into a mixture of citrulline and ornithine under all conditions tested. However, the ratio between these end-products and the pattern of their formation showed variation as a function of environmental pH. Under optimal pH conditions for growth, citrulline release and some further conversion into ornithine was observed. When growing under sub-optimal pH conditions, ornithine was the main product of the ADI pathway. These kinetic data suggest a role in adaptation of L. fermentum IMDO 130101 to growth under sub-optimal conditions.

  16. Age-dependent damage of hair cuticle: contribution of S100A3 protein and its citrullination.

    PubMed

    Takahashi, Toshie; Mamada, Akira; Kizawa, Kenji; Suzuki, Ryosuke

    2016-09-01

    There are two types of damage pattern of human hair cuticle: type L, where the cell membrane complex is split and the cuticle lifts up, and type E, where the fragile substructure of the cuticle cell (endocuticle) is broken. In our previous paper, it was reported that the dominant damage pattern shifts from type L to E with the subjects' age around the 40s. Loss of the cuticle due to daily grooming stresses increases with the subjects' age and is related to the level of type E damage. It is supposed that deterioration of endocuticle advances the loss of cuticle. S100A3 protein, located at the endocuticle, was found to be citrullinated and transformed into tetramer to improve its Ca(2+) -binding ability. It is postulated that this biochemical property affects the maturation of cuticle and contributes to its reinforcement. This study aims to elucidate the role that S100A3 plays in age-dependent cuticle damage. Hair fibers collected from Japanese females were evaluated for the content and citrullination rate of S100A3, incidence of type E damage, and resistance of cuticle. In the aged hair, the content of S100A3 was positively correlated with the level of type E damage and low resistance to stress. Hair fibers in which S100A3 is highly citrullinated, however, showed low levels of type E damage and high resistance of cuticle, even in the aged hair as well as at younger ages. S100A3 and its citrullination process are related to rigidity of endocuticle of aged hair. © 2015 Wiley Periodicals, Inc.

  17. Theoretical insights into the protonation states of active site cysteine and citrullination mechanism of Porphyromonas gingivalis peptidylarginine deiminase.

    PubMed

    Zhao, Chenxiao; Ling, Baoping; Dong, Lihua; Liu, Yongjun

    2017-08-01

    Porphyromonas gingivalis peptidylarginine deiminase (PPAD) catalyzes the citrullination of peptidylarginine, which plays a critical role in the rheumatoid arthritis (RA) and gene regulation. For a better understanding of citrullination mechanism of PPAD, it is required to establish the protonation states of active site cysteine, which is still a controversial issue for the members of guanidino-group-modifying enzyme superfamily. In this work, we first explored the transformation between the two states: State N (both C351 and H236 are neutral) and State I (both residues exist as a thiolate-imidazolium ion pair), and then investigated the citrullination reaction of peptidylarginine, using a combined QM/MM approach. State N is calculated to be more stable than State I by 8.46 kcal/mol, and State N can transform to State I via two steps of substrate-assisted proton transfer. Citrullination of the peptidylarginine contains deamination and hydrolysis. Starting from State N, the deamination reaction corresponds to an energy barrier of 18.82 kcal/mol. The deprotonated C351 initiates the nucleophilic attack to the substrate, which is the key step for deamination reaction. The hydrolysis reaction contains two chemical steps. Both the deprotonated D238 and H236 can act as the bases to activate the hydrolytic water, which correspond to similar energy barriers (∼17 kcal/mol). On the basis of our calculations, C351, D238, and H236 constitute a catalytic triad, and their protonation states are critical for both the deamination and hydrolysis processes. In view of the sequence similarity, these findings may be shared with human PAD1-PAD4 and other guanidino-group-modifying enzymes. Proteins 2017; 85:1518-1528. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  18. Studies on L-citrulline doped potassium dihydrogen phosphate- A non linear crystal with significant nonlinear properties

    NASA Astrophysics Data System (ADS)

    Sreevalsa, V. G.; Jayalekshmi, S.

    2014-01-01

    Potassium Dihydrogen Phosphate (KDP) single crystal is considered as one of the best representative of nonlinear optical crystals. Recently, amino acids having excellent nonlinear optical characteristics are being investigated as prospective dopants to improve the non linear optical characteristics of KDP. The present work is an attempt in this direction and L citrulline, one of the non essential amino acids showing good non linear optical characteristics is used as the dopant for KDP. Good quality crystals of L-citrulline doped KDP crystals were grown by slow evaporation technique. From the powder X-ray diffraction studies of doped KDP crystal, the structure of the doped crystals was determined by direct method and refined by Pawley method employing Topaz version program using the single crystal X-ray data for pure KDP. The lattice parameters for L citrulline doped KDP are a=7.467A0, b=7.467 A0, c=6.977 A0. The crystal falls into the tetragonal crystal system with space group I42 d. The presence of carbon and oxygen, which are primary components of amino acids, in the EDAX spectrum confirms the effectiveness of doping. The absorption spectra of the doped samples show that the crystals are transparent in the entire visible region. The second harmonic generation efficiency of the doped samples was determined by Kurtz powder technique using the Q-switched Nd:YAG laser beam and is found to be 2.2 times that of KDP. The nonlinear optical properties can be well studied by the open aperture Z scan technique. The open aperture curve exhibits a normalized transmittance valley. The nonlinear absorption coefficient β is obtained by theoretical fitting for two photon absorption. It is inferred that doping KDP with L citrulline has enhanced the nonlinearity considerably. This obviously suggests the potentiality of the crystal as an optical power limiter and also for various optical device applications.

  19. Studies on L-citrulline doped potassium dihydrogen phosphate- A non linear crystal with significant nonlinear properties

    SciTech Connect

    Sreevalsa, V. G. E-mail: jayalekshmi@cusat.ac.in; Jayalekshmi, S. E-mail: jayalekshmi@cusat.ac.in

    2014-01-28

    Potassium Dihydrogen Phosphate (KDP) single crystal is considered as one of the best representative of nonlinear optical crystals. Recently, amino acids having excellent nonlinear optical characteristics are being investigated as prospective dopants to improve the non linear optical characteristics of KDP. The present work is an attempt in this direction and L citrulline, one of the non essential amino acids showing good non linear optical characteristics is used as the dopant for KDP. Good quality crystals of L-citrulline doped KDP crystals were grown by slow evaporation technique. From the powder X-ray diffraction studies of doped KDP crystal, the structure of the doped crystals was determined by direct method and refined by Pawley method employing Topaz version program using the single crystal X-ray data for pure KDP. The lattice parameters for L citrulline doped KDP are a=7.467A{sup 0}, b=7.467 A{sup 0}, c=6.977 A{sup 0}. The crystal falls into the tetragonal crystal system with space group I42 d. The presence of carbon and oxygen, which are primary components of amino acids, in the EDAX spectrum confirms the effectiveness of doping. The absorption spectra of the doped samples show that the crystals are transparent in the entire visible region. The second harmonic generation efficiency of the doped samples was determined by Kurtz powder technique using the Q-switched Nd:YAG laser beam and is found to be 2.2 times that of KDP. The nonlinear optical properties can be well studied by the open aperture Z scan technique. The open aperture curve exhibits a normalized transmittance valley. The nonlinear absorption coefficient β is obtained by theoretical fitting for two photon absorption. It is inferred that doping KDP with L citrulline has enhanced the nonlinearity considerably. This obviously suggests the potentiality of the crystal as an optical power limiter and also for various optical device applications.

  20. Modular pathway engineering of Corynebacterium glutamicum for production of the glutamate-derived compounds ornithine, proline, putrescine, citrulline, and arginine.

    PubMed

    Jensen, Jaide V K; Eberhardt, Dorit; Wendisch, Volker F

    2015-11-20

    The glutamate-derived bioproducts ornithine, citrulline, proline, putrescine, and arginine have applications in the food and feed, cosmetic, pharmaceutical, and chemical industries. Corynebacterium glutamicum is not only an excellent producer of glutamate but also of glutamate-derived products. Here, engineering targets beneficial for ornithine production were identified and the advantage of rationally constructing a platform strain for the production of the amino acids citrulline, proline, and arginine, and the diamine putrescine was demonstrated. Feedback alleviation of N-acetylglutamate kinase, tuning of the promoter of glutamate dehydrogenase gene gdh, lowering expression of phosphoglucoisomerase gene pgi, along with the introduction of a second copy of the arginine biosynthesis operon argCJB(A49V,M54V)D into the chromosome resulted in a C. glutamicum strain producing ornithine with a yield of 0.52 g ornithine per g glucose, an increase of 71% as compared to the parental ΔargFRG strain. Strains capable of producing 0.41 g citrulline per g glucose, 0.29 g proline per g glucose, 0.30 g arginine per g glucose, and 0.17 g putrescine per g glucose were derived from the ornithine-producing platform strain by plasmid-based overexpression of appropriate pathway modules with one to three genes.

  1. Comparison of Two Assays to Determine Anti-Citrullinated Peptide Antibodies in Rheumatoid Arthritis in relation to Other Chronic Inflammatory Rheumatic Diseases: Assaying Anti-Modified Citrullinated Vimentin Antibodies Adds Value to Second-Generation Anti-Citrullinated Cyclic Peptides Testing

    PubMed Central

    Díaz-Toscano, Miriam Lizette; Olivas-Flores, Eva Maria; Zavaleta-Muñiz, Soraya Amali; Gamez-Nava, Jorge Ivan; Cardona-Muñoz, Ernesto German; Ponce-Guarneros, Manuel; Castro-Contreras, Uriel; Nava, Arnulfo; Salazar-Paramo, Mario; Celis, Alfredo; Fajardo-Robledo, Nicte Selene; Corona-Sanchez, Esther Guadalupe; Gonzalez-Lopez, Laura

    2014-01-01

    Determination of anti-citrullinated peptide antibodies (ACPA) plays a relevant role in the diagnosis of rheumatoid arthritis (RA). To date, it is still unclear if the use of several tests for these autoantibodies in the same patient offers additional value as compared to performing only one test. Therefore, we evaluated the performance of using two assays for ACPA: second-generation anti-citrullinated cyclic peptides antibodies (anti-CCP2) and anti-mutated citrullinated vimentin (anti-MCV) antibodies for the diagnosis of RA. We compared three groups: RA (n = 142), chronic inflammatory disease (CIRD, n = 86), and clinically healthy subjects (CHS, n = 56) to evaluate sensitivity, specificity, predictive values, and likelihood ratios (LR) of these two assays for the presence of RA. A lower frequency of positivity for anti-CCP2 was found in RA (66.2%) as compared with anti-MCV (81.0%). When comparing RA versus other CIRD, sensitivity increased when both assays were performed. This strategy of testing both assays had high specificity and LR+. We conclude that adding the assay of anti-MCV antibodies to the determination of anti-CCP2 increases the sensitivity for detecting seropositive RA. Therefore, we propose the use of both assays in the initial screening of RA in longitudinal studies, including early onset of undifferentiated arthritis. PMID:25025037

  2. Comparison of two assays to determine anti-citrullinated peptide antibodies in rheumatoid arthritis in relation to other chronic inflammatory rheumatic diseases: assaying anti-modified citrullinated vimentin antibodies adds value to second-generation anti-citrullinated cyclic peptides testing.

    PubMed

    Díaz-Toscano, Miriam Lizette; Olivas-Flores, Eva Maria; Zavaleta-Muñiz, Soraya Amali; Gamez-Nava, Jorge Ivan; Cardona-Muñoz, Ernesto German; Ponce-Guarneros, Manuel; Castro-Contreras, Uriel; Nava, Arnulfo; Salazar-Paramo, Mario; Celis, Alfredo; Fajardo-Robledo, Nicte Selene; Corona-Sanchez, Esther Guadalupe; Gonzalez-Lopez, Laura

    2014-01-01

    Determination of anti-citrullinated peptide antibodies (ACPA) plays a relevant role in the diagnosis of rheumatoid arthritis (RA). To date, it is still unclear if the use of several tests for these autoantibodies in the same patient offers additional value as compared to performing only one test. Therefore, we evaluated the performance of using two assays for ACPA: second-generation anti-citrullinated cyclic peptides antibodies (anti-CCP2) and anti-mutated citrullinated vimentin (anti-MCV) antibodies for the diagnosis of RA. We compared three groups: RA (n = 142), chronic inflammatory disease (CIRD, n = 86), and clinically healthy subjects (CHS, n = 56) to evaluate sensitivity, specificity, predictive values, and likelihood ratios (LR) of these two assays for the presence of RA. A lower frequency of positivity for anti-CCP2 was found in RA (66.2%) as compared with anti-MCV (81.0%). When comparing RA versus other CIRD, sensitivity increased when both assays were performed. This strategy of testing both assays had high specificity and LR+. We conclude that adding the assay of anti-MCV antibodies to the determination of anti-CCP2 increases the sensitivity for detecting seropositive RA. Therefore, we propose the use of both assays in the initial screening of RA in longitudinal studies, including early onset of undifferentiated arthritis.

  3. Anti-citrullinated-protein-antibody-specific intravenous immunoglobulin attenuates collagen-induced arthritis in mice

    PubMed Central

    Svetlicky, N; Kivity, S; Odeh, Q; Shovman, O; Gertel, S; Amital, H; Gendelman, O; Volkov, A; Barshack, I; Bar-Meir, E; Blank, M; Shoenfeld, Y

    2015-01-01

    Administration of intravenous immunoglobulin (IVIg) is a recognized safe and efficient immunomodulation therapy for many autoimmune diseases. Anti-idiotypic antibody binding to pathogenic autoantibodies was proposed as one of the mechanisms attributed to the protective activity of IVIg in autoimmunity. The aim of this study was to fractionate the anti-anti-citrullinated protein anti-idiotypic-antibodies (anti-ACPA) from an IVIg preparation and to test it as a treatment for collagen-induced arthritis in mice. IVIg was loaded onto an ACPA column. The eluted fraction was defined as ACPA-specific-IVIg (ACPA-sIVIg). Collagen-induced-arthritis (CIA) was induced in mice. Mice were treated weekly with ACPA-sIVIg, low-dose-IVIg, high-dose-IVIg and phosphate-buffered saline (PBS). Sera-ACPA titres, anti-collagen anitbodies and cytokine levels were analysed by enzyme-linked immunosorbent assay (ELISA); antibody-forming-cell activity by enzyme-linked imunospot (ELISPOT) assay; and expansion of regulatory T cell (Treg) population by fluorescence activated cell sorter (FACS). ACPA-sIVIg inhibited ACPA binding to citrullinated-peptides (CCP) in vitro 100 times more efficiently than the IVIg compound. ACPA-sIVIg was significantly more effective than the IVIg-preparation in attenuating the development of collagen-induced arthritis. Splenocytes from CIA mice treated with ACPA-sIVIg reduced the ACPA and anti-collagen-antibody titres, including the number of anti-collagen and ACPA antibody-forming cells. In parallel, splenocytes from ACPA-sIVIg treated mice secreted higher levels of anti-inflammatory cytokines and lower proinflammatory cytokines. The ACPA-sIVIg inhibitory potential was accompanied with expansion of the Treg population. Low-dose IVIg did not affect the humoral and cellular response in the CIA mice in comparison to the PBS-treated mice. Based on our results, IVIg may be considered as a safe compound for treating patients with rheumatoid arthritis by neutralizing

  4. Anti-carbamylated Protein Antibody Levels Correlate with Anti-Sa (Citrullinated Vimentin) Antibody Levels in Rheumatoid Arthritis.

    PubMed

    Challener, Gregory J; Jones, Jonathan D; Pelzek, Adam J; Hamilton, B JoNell; Boire, Gilles; de Brum-Fernandes, Artur José; Masetto, Ariel; Carrier, Nathalie; Ménard, Henri A; Silverman, Gregg J; Rigby, William F C

    2016-02-01

    The presence of anticitrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA) indicates a breach in immune tolerance. Recent studies indicate that this breach extends to homocitrullination of lysines with the formation of anti-carbamylated protein (anti-CarP) antibodies. We analyzed the clinical and serologic relationships of anti-CarP in 2 RA cohorts. Circulating levels of immunoglobulin G anti-CarP antibodies were determined by ELISA in established (Dartmouth-Hitchcock Medical Center) and early (Sherbrooke University Hospital Center) cohorts and evaluated for anticyclic citrullinated peptide antibodies (anti-CCP), specific ACPA, and rheumatoid factor (RF) levels using the Student t test and correlation analysis. We identified elevated anti-CarP antibodies titers in 47.0% of seropositive patients (Dartmouth, n = 164), with relationships to anti-CCP (p < 0.0001) and IgM-RF (p = 0.001). Similarly, 38.2% of seropositive patients from the Sherbrooke cohort (n = 171) had elevated anti-CarP antibodies; titers correlated to anti-CCP (p = 0.01) but not IgM-RF (p = 0.09). A strong correlation with anti-Sa was observed: 47.9% anti-Sa+ patients were anti-CarP antibodies+ versus only 25.4% anti-Sa- in the Sherbrooke cohort (p = 0.0002), and 62.6% anti-Sa+ patients versus 26.9% anti-Sa- were anti-CarP antibodies+ in Dartmouth (p < 0.0001). We found a more variable response for reactivity to citrullinated fibrinogen or to citrullinated peptides from fibrinogen and α enolase. In 2 North American RA cohorts, we observed a high prevalence of anti-CarP antibody positivity. We also describe a surprising and unexpected association of anti-CarP with anti-Sa antibodies that could not be explained by cross-reactivity. Further, considerable heterogeneity exists between anti-CarP reactivity and other citrullinated peptide reactivity, raising the question of how the pathogenesis of antibody responses for carbamylated proteins and citrullinated proteins may be linked in vivo.

  5. Structure and mechanism of a bacterial host-protein citrullinating virulence factor, Porphyromonas gingivalis peptidylarginine deiminase

    PubMed Central

    Goulas, Theodoros; Mizgalska, Danuta; Garcia-Ferrer, Irene; Kantyka, Tomasz; Guevara, Tibisay; Szmigielski, Borys; Sroka, Aneta; Millán, Claudia; Usón, Isabel; Veillard, Florian; Potempa, Barbara; Mydel, Piotr; Solà, Maria; Potempa, Jan; Gomis-Rüth, F. Xavier

    2015-01-01

    Citrullination is a post-translational modification of higher organisms that deiminates arginines in proteins and peptides. It occurs in physiological processes but also pathologies such as multiple sclerosis, fibrosis, Alzheimer’s disease and rheumatoid arthritis (RA). The reaction is catalyzed by peptidylarginine deiminases (PADs), which are found in vertebrates but not in lower organisms. RA has been epidemiologically associated with periodontal disease, whose main infective agent is Porphyromonas gingivalis. Uniquely among microbes, P. gingivalis secretes a PAD, termed PPAD (Porphyromonas peptidylarginine deiminase), which is genetically unrelated to eukaryotic PADs. Here, we studied function of PPAD and its substrate-free, substrate-complex, and substrate-mimic-complex structures. It comprises a flat cylindrical catalytic domain with five-fold α/β-propeller architecture and a C-terminal immunoglobulin-like domain. The PPAD active site is a funnel located on one of the cylinder bases. It accommodates arginines from peptide substrates after major rearrangement of a “Michaelis loop” that closes the cleft. The guanidinium and carboxylate groups of substrates are tightly bound, which explains activity of PPAD against arginines at C-termini but not within peptides. Catalysis is based on a cysteine-histidine-asparagine triad, which is shared with human PAD1-PAD4 and other guanidino-group modifying enzymes. We provide a working mechanism hypothesis based on 18 structure-derived point mutants. PMID:26132828

  6. Determination of Anticyclic Citrullinated Peptide Based on Biotin-Streptavidin-Amplified Time-Resolved Fluoroimmunoassay.

    PubMed

    Sheng, Huiming; Hu, Zhi-Gang; Liu, Jie; Yuan, Fenghong; Li, Mei; Zou, Yaohong; Chen, Yu

    2015-11-01

    A rapid and sensitive time-resolved fluoroimmunoassay (TRFIA) based on the biotin-streptavidin amplification system was developed for the determination of anticyclic citrullinated peptide (anti-CCP). Europium-labeled streptavidin derivatives combined with europium and anhydride of diethylene triamine pentaacetic acid were used to label streptavidin, biotin was coupled with rabbit anti-human IgG to form a biotin-anti-human IgG bridge between streptavidin-europium and the anti-CCP antibody in the immunoassay. The anti-CCP assay was carried out by measuring the fluorescence of Eu(3+) -streptavidin at 615 nm. The presented method produced a wide linear range from 0.58 to 9,463 U/ml, while it was only 591.4-18.48 U/ml when using an ELISA kit, and featured a detection limit up to 0.5 U/ml for anti-CCP. The values determined by the biotin-streptavidin-TRFIA and ELISA correlated well (R(2) = 0.8927). The method was applied to determine anti-CCP in serum samples with satisfied recoveries of 96.45-104.63%. The assay results obtained by the present method showed that biotin-streptavidin-amplified TRFIA improve the traditional ELISA kit for anti-CCP detection. Therefore, it offers a better alternative immunoassay in rheumatoid arthritis management. © 2014 Wiley Periodicals, Inc.

  7. Two different approaches to restore renal nitric oxide and prevent hypertension in young spontaneously hypertensive rats: l-citrulline and nitrate.

    PubMed

    Chien, Shao-Ju; Lin, Kuan-Miao; Kuo, Hsuan-Chang; Huang, Chien-Fu; Lin, Ying-Jui; Huang, Li-Tung; Tain, You-Lin

    2014-01-01

    Nitric oxide (NO) deficiency mediates oxidative stress in the kidney and is involved in the development of hypertension. NO synthesis occurs via 2 pathways: nitric oxide synthase (NOS) dependent and NOS-independent. We tested whether the development of hypertension is prevented by restoration of NO by dietary l-citrulline or nitrate supplementation in young spontaneously hypertensive rats (SHRs). Male SHRs and normotensive Wistar Kyoto control rats (WKYs)s age 4 weeks were assigned to 4 groups: untreated SHRs and WKYs, and SHRs and WKYs that received 0.25% l-citrulline for 8 weeks. In our second series of studies, we replaced l-citrulline with 1 mmol/kg/d sodium nitrate. All rats were sacrificed at age 12 weeks. We found an increase in the blood pressure of SHRs was prevented by dietary supplementation of l-citrulline or nitrate. Both treatments restored NO bioavailability and reduced oxidative stress in SHR kidneys. l-Citrulline therapy reduced levels of l-arginine and asymmetric dimethylarginine (ADMA)-an endogenous inhibitor of NOS-and increased the l-arginine-to-ADMA ratio in SHR kidneys. Nitrate treatment reduced plasma levels of l-arginine and ADMA concurrently in SHRs. Our findings suggest that both NOS-dependent and -independent approaches in the prehypertensive stage toward augmentation of NO can prevent the development of hypertension in young SHRs. Copyright © 2014 Mosby, Inc. All rights reserved.

  8. Neonatal Citrulline Supplementation and Later Exposure to a High Fructose Diet in Rats Born with a Low Birth Weight: A Preliminary Report.

    PubMed

    Tran, Nhat-Thang; Alexandre-Gouabau, Marie-Cécile; Pagniez, Anthony; Ouguerram, Khadija; Boquien, Clair-Yves; Winer, Norbert; Darmaun, Dominique

    2017-04-11

    A low birth weight (LBW) leads to a higher risk of metabolic syndrome in adulthood. Literature suggests that citrulline supplementation in adulthood prevents the effect of a high fructose diet on energy metabolism. Whether neonatal citrulline supplementation would alter early growth or energy metabolism in the long-term in rats with LBW is unknown. LBW pups born from dams fed a low (4%) protein diet, were nursed by normally-fed dams and received isonitrogenous supplements of either l-citrulline or l-alanine by gavage from the sixth day of life until weaning, and were subsequently exposed to 10%-fructose in drinking water from weaning to 90 days of age. The oral glucose tolerance was tested (OGTT) at 70 days of age, and rats were sacrificed at 90 days of age. Pre-weaning citrulline supplementation failed to alter the growth trajectory, OGTT, plasma triglycerides, or fat mass accretion in adulthood; yet, it was associated with increased liver triglycerides, decreased liver total cholesterol, and a distinct liver lipidomic profile that may result in a predisposition to liver disease. We conclude that pre-weaning supplementation with citrulline does not impact early growth, but might impact liver fat metabolism in adulthood upon exposure to a high fructose diet.

  9. Characteristics of L-citrulline transport through blood-brain barrier in the brain capillary endothelial cell line (TR-BBB cells).

    PubMed

    Lee, Kyeong-Eun; Kang, Young-Sook

    2017-05-10

    L-Citrulline is a neutral amino acid and a major precursor of L-arginine in the nitric oxide (NO) cycle. Recently it has been reported that L-citrulline prevents neuronal cell death and protects cerebrovascular injury, therefore, L-citrulline may have a neuroprotective effect to improve cerebrovascular dysfunction. Therefore, we aimed to clarify the brain transport mechanism of L-citrulline through blood-brain barrier (BBB) using the conditionally immortalized rat brain capillary endothelial cell line (TR-BBB cells), as an in vitro model of the BBB. The uptake study of [(14)C] L-citrulline, quantitative real-time polymerase chain reaction (PCR) analysis, and rLAT1, system b(0,+), and CAT1 small interfering RNA study were performed in TR-BBB cells. The uptake of [(14)C] L-citrulline was a time-dependent, but ion-independent manner in TR-BBB cells. The transport process involved two saturable components with a Michaelis-Menten constant of 30.9 ± 1.0 μM (Km1) and 1.69 ± 0.43 mM (Km2). The uptake of [(14)C] L-citrulline in TR-BBB cells was significantly inhibited by neutral and cationic amino acids, but not by anionic amino acids. In addition, [(14)C]L-citrulline uptake in the cells was markedly inhibited by 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH), which is the inhibitor of the large neutral amino acid transporter 1 (LAT1), B(0), B(0,+) and harmaline, the inhibitor of system b(0,+). Gabapentin and L-dopa as the substrates of LAT1 competitively inhibited the uptake of [(14)C] L-citrulline. IC50 values for L-dopa, gabapentin, L-phenylalanine and L-arginine were 501 μM, 223 μM, 68.9 μM and 33.4 mM, respectively. The expression of mRNA for LAT1 was predominantly increased 187-fold in comparison with that of system b(0,+) in TR-BBB cells. In the studies of LAT1, system b(0,+) and CAT1 knockdown via siRNA transfection into TR-BBB cells, the transcript level of LAT1 and [(14)C] L-citrulline uptake by LAT1 siRNA were significantly reduced

  10. A novel role for protein arginine deiminase 4 in pluripotency: the emerging role of citrullinated histone H1 in cellular programming.

    PubMed

    Slade, Daniel J; Horibata, Sachi; Coonrod, Scott A; Thompson, Paul R

    2014-08-01

    Histone post-translational modifications (PTMs) alter the chromatin architecture, generating "open" and "closed" states, and these structural changes can modulate gene expression under specific cellular conditions. While methylation and acetylation are the best-characterized histone PTMs, citrullination by the protein arginine deiminases (PADs) represents another important player in this process. In addition to "fine tuning" chromatin structure at specific loci, histone citrullination can also promote rapid global chromatin decondensation during the formation of extracellular traps (ETs) in immune cells. Recent studies now show that PAD4-mediated citrullination of histone H1 at promoter elements can also promote localized chromatin decondensation in stem cells, thus regulating the pluripotent state. These observations suggest that PAD-mediated histone deimination profoundly affects chromatin structure, possibly above and beyond that of other PTMs. Additionally, these recent findings further enhance our understanding of PAD biology and the important contributions that these enzymes play in development, health, and disease.

  11. Characterization of Autoantigens Targeted by Anti-Citrullinated Protein Antibodies In Vivo: Prominent Role for Epitopes Derived from Histone 4 Proteins.

    PubMed

    Meng, Xiaobo; Ezzati, Peyman; Smolik, Irene; Bernstein, Charles N; Hitchon, Carol Ann; El-Gabalawy, Hani S

    2016-01-01

    Anti-citrullinated protein antibodies (ACPA) have become an integral part of the clinical definition of rheumatoid arthritis, and are hypothesized to be important in the immunopathogenesis of this autoimmune disease. Several citrullinated proteins have been demonstrated to serve as candidate autoantigens for the ACPA, based on in vitro immune reactions between citrullinated peptides/proteins and RA sera. Yet it remains unclear whether the autoantigens identified in vitro are indeed directly and specifically targeted by the ACPA in vivo. Moreover, it is unclear whether ACPA present in RA sera are directed towards the same spectrum of autoantigens as the ACPA present within the synovial compartment. In this study, we isolated ACPA immune complexes from RA synovial fluids (SF) and sera by using immobilized cyclic citrullinated peptides (CCP3) based immune affinity, and characterized the proteins that are directly and specifically associated with them by mass spectrometry. The results demonstrate that four histone proteins are prominent ACPA autoantigens, with the frequency of detection being histone H4 (89%), H2B (63%), H3 (63%), and H2A (58%) in ACPA positive RA SF. We further demonstrate that a histone 4 peptide containing citrulline at position Cit39 was recognized by 100% of ACPA positive RA SF. An adjacent citrulline residue at Cit40 was recognized by 34% of ACPA positive RA SF. An H4 peptide containing Cit39-40 was recognized in the serum of 94% ACPA positive RA, 77% ACPA positive first-degree relatives (FDR) of RA patients, and 2.5% of healthy controls. The Cit39-40 peptide substantially blocked the ACPA reactivity in both SF and serum. Although the spectrum of ACPA we identified was limited to those isolated using immobilized CCP3 peptides, the findings indicate that H4 is a widely recognized RA autoantigen in both the synovial and serum compartments. The identification of this immunodominant ACPA epitope may be valuable in designing approaches to immune

  12. Characterization of Autoantigens Targeted by Anti-Citrullinated Protein Antibodies In Vivo: Prominent Role for Epitopes Derived from Histone 4 Proteins

    PubMed Central

    Meng, Xiaobo; Ezzati, Peyman; Smolik, Irene; Bernstein, Charles N.; Hitchon, Carol Ann; El-Gabalawy, Hani S.

    2016-01-01

    Anti-citrullinated protein antibodies (ACPA) have become an integral part of the clinical definition of rheumatoid arthritis, and are hypothesized to be important in the immunopathogenesis of this autoimmune disease. Several citrullinated proteins have been demonstrated to serve as candidate autoantigens for the ACPA, based on in vitro immune reactions between citrullinated peptides/proteins and RA sera. Yet it remains unclear whether the autoantigens identified in vitro are indeed directly and specifically targeted by the ACPA in vivo. Moreover, it is unclear whether ACPA present in RA sera are directed towards the same spectrum of autoantigens as the ACPA present within the synovial compartment. In this study, we isolated ACPA immune complexes from RA synovial fluids (SF) and sera by using immobilized cyclic citrullinated peptides (CCP3) based immune affinity, and characterized the proteins that are directly and specifically associated with them by mass spectrometry. The results demonstrate that four histone proteins are prominent ACPA autoantigens, with the frequency of detection being histone H4 (89%), H2B (63%), H3 (63%), and H2A (58%) in ACPA positive RA SF. We further demonstrate that a histone 4 peptide containing citrulline at position Cit39 was recognized by 100% of ACPA positive RA SF. An adjacent citrulline residue at Cit40 was recognized by 34% of ACPA positive RA SF. An H4 peptide containing Cit39-40 was recognized in the serum of 94% ACPA positive RA, 77% ACPA positive first-degree relatives (FDR) of RA patients, and 2.5% of healthy controls. The Cit39-40 peptide substantially blocked the ACPA reactivity in both SF and serum. Although the spectrum of ACPA we identified was limited to those isolated using immobilized CCP3 peptides, the findings indicate that H4 is a widely recognized RA autoantigen in both the synovial and serum compartments. The identification of this immunodominant ACPA epitope may be valuable in designing approaches to immune

  13. Anti-citrullinated glucose-6-phosphate isomerase peptide antibodies in patients with rheumatoid arthritis are associated with HLA-DRB1 shared epitope alleles and disease activity

    PubMed Central

    Umeda, N; Matsumoto, I; Ito, I; Kawasaki, A; Tanaka, Y; Inoue, A; Tsuboi, H; Suzuki, T; Hayashi, T; Ito, S; Tsuchiya, N; Sumida, T

    2013-01-01

    To identify and characterize anti-citrullinated glucose-6-phosphate isomerase (GPI) peptide antibodies in patients with rheumatoid arthritis (RA). Nine GPI arginine-bearing peptides in human GPI protein were selected and cyclic citrullinated GPI peptides (CCG-1–9) were constructed. Samples were obtained from RA (n = 208), systemic lupus erythematosus (SLE) (n = 101), Sjögren's syndrome (SS; n = 101) and healthy controls (n = 174). Antibodies against CCG-1–9 were measured, and anti-citrullinated α-enolase-1 (CEP-1), -cyclic citrullinated peptides (CCP) and -GPI proteins antibodies were also examined. Patients with RA were genotyped for HLA-DRB1. The numbers of shared epitope (SE) alleles were counted and compared with those of the autoantibodies. Rabbit GPI was citrullinated with rabbit peptidylarginine deiminase and immunoblot analysis of RA sera performed. The levels of autoantibodies were compared before and after treatment with TNF antagonists in 58 RA patients. Anti-CCG-2, -4 and -7 antibodies were detected in 25·5, 33·2 and 37·0% patients with RA, respectively, and these antibodies were very specific for RA (specificity, 98·1–99·7%). Altogether, 44·2, 86·1 and 13·9% of RA sera were positive for anti-CEP-1, -CCP and -GPI protein antibodies, respectively. Anti-CCG-2, -4 and -7 antibodies were correlated with anti-CCP and anti-CEP-1 antibodies and with the presence of HLA-DRB1 SE alleles. Citrullinated GPI protein was detected using RA sera. Treatment with tumour necrosis factor antagonists reduced significantly the levels of anti-CCG-2 and -7 but not of anti-CEP-1 antibodies. This is the first report documenting the presence of anti-CCG antibodies in RA. Anti-CCG-2 and -7 antibodies could be considered as markers for the diagnosis of RA and its disease activity. PMID:23480184

  14. Reduced TCR-dependent activation through citrullination of a T-cell epitope enhances Th17 development by disruption of the STAT3/5 balance.

    PubMed

    Tibbitt, Christopher; Falconer, Jane; Stoop, Jeroen; van Eden, Willem; Robinson, John H; Hilkens, Catharien M U

    2016-07-01

    Citrullination is a post-translational modification of arginine that commonly occurs in inflammatory tissues. Because T-cell receptor (TCR) signal quantity and quality can regulate T-cell differentiation, citrullination within a T-cell epitope has potential implications for T-cell effector function. Here, we investigated how citrullination of an immunedominant T-cell epitope affected Th17 development. Murine naïve CD4(+) T cells with a transgenic TCR recognising p89-103 of the G1 domain of aggrecan (agg) were co-cultured with syngeneic bone marrow-derived dendritic cells (BMDC) presenting the native or citrullinated peptides. In the presence of pro-Th17 cytokines, the peptide citrullinated on residue 93 (R93Cit) significantly enhanced Th17 development whilst impairing the Th2 response, compared to the native peptide. T cells responding to R93Cit produced less IL-2, expressed lower levels of the IL-2 receptor subunit CD25, and showed reduced STAT5 phosphorylation, whilst STAT3 activation was unaltered. IL-2 blockade in native p89-103-primed T cells enhanced the phosphorylated STAT3/STAT5 ratio, and concomitantly enhanced Th17 development. Our data illustrate how a post-translational modification of a TCR contact point may promote Th17 development by altering the balance between STAT5 and STAT3 activation in responding T cells, and provide new insight into how protein citrullination may influence effector Th-cell development in inflammatory disorders. © 2016 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. [New autoanti-bodies in rheumatoid arthritis: anti-citrullinated protein or peptide autoanti-bodies and the others].

    PubMed

    Fabien, Nicole; Goetz, Joëlle; Sordet, Christelle; Humbel, René-Louis; Sibilia, Jean

    2008-12-01

    New treatment strategies require that rheumatoid arthritis (RA) be diagnosed as early as possible. New diagnostic markers were required, because rheumatoid factors (RF), until now criteria for classification of RA, are not sufficiently specific and sometimes appear late, thereby limiting their diagnostic usefulness. The objective of this review is to describe the current state of knowledge and more particularly to analyze the interest of new RA autoanti-bodies, called anti-peptide or anti-citrullinated protein anti-bodies (ACPA). Other autoanti-bodies have been described, including anti-Sa, anti-alpha enolase, and anti-calpastatin autoanti-bodies. Nonetheless, their diagnostic value remains limited compared to ACPA. Accordingly, in daily practice today, the only autoanti-bodies that must be tested for to diagnose RA are the ACPAs and RFs. The discovery of ACPA (initially called anti-keratin and anti-perinuclear anti-bodies) was a major step forward for the laboratory diagnosis of RA. The tests most often used routinely areenzyme-linked immunosorbent assays(ELISA) with cyclic citrullinated peptides, whence the name anti-CCP autoanti-bodies. Accordingly, the two terms ACPA and anti-CCP can both be used. The diagnostic value, in particular their specificity, is on the order of 95%, regardless of the method of identification. These markers are very useful and are often present earlier than RF. These ACPA also have prognostic value because they are associated with more aggressive forms of RA. On the other hand, their value over time, in particular, their fluctuation as a function of treatment, is more controversial. In practice, it is recommended to test for both RF and ACPA in a diagnostic work-up for early RA. During follow-up, the value of testing for these autoanti-bodies has not been demonstrated, but additional studies are still necessary with the anti-CCP autoanti-bodies and the new anti-citrullinated protein autoanti-bodies.

  16. Citrulline specific Th1 cells are increased in rheumatoid arthritis and their frequency is influenced by disease duration and therapy

    PubMed Central

    James, Eddie; Rieck, Mary; Pieper, Jennifer; Gebe, John A.; Yue, Betty B.; Tatum, Megan; Peda, Melissa; Sandin, Charlotta; Klareskog, Lars; Malmström, Vivianne; Buckner, Jane H.

    2014-01-01

    Objective Rheumatoid arthritis is thought to be a T cell mediated disease, based on its strong association with HLA class II alleles, clinical responsiveness to T cell directed therapies and the presence of CD4 T cells in rheumatoid joints. The presence of ACPA in RA serum and the association of these antibodies with HLA-DR4 alleles implicates citrullinated specific autoreactive T cells in the development and progression of RA. The goal of this study was to determine the character and specificity of auto-reactive T cell responses in RA. Methods We developed a panel of HLA-DRB1*04:01 tetramers, selecting citrullinated peptides from synovial antigens and verifying their immunogenicity in DRB1*04:01 transgenic mice. Seven tetramers were used to examine the ex vivo frequency and surface phenotype of cit-specific T cells in RA and healthy subjects with DRB1*04:01 haplotypes using a magnetic enrichment procedure. Results Cit-specific T cells were detectable in peripheral blood samples from both healthy subjects and RA patients. In comparison to healthy subjects, RA patients had significantly higher frequencies of cit-specific T cells and a greater proportion of these cells displayed a Th1 memory phenotype. Among RA subjects the frequency of cit-specific T cells was highest within the first 5 years after diagnosis of RA and was decreased in patients taking biologic therapies irrespective of disease duration. Conclusion These findings link the presence of ACPA in RA with Th1 cells specific to citrullinated epitopes and provide tools for disease-specific immunomonitoring of autoreactive T cells. PMID:24665079

  17. Prevention of perceptual-motor decline by branched-chain amino acids, arginine, citrulline after tennis match.

    PubMed

    Yang, C-C; Wu, C-L; Chen, I-F; Chang, C-K

    2017-09-01

    Perceptual-motor performance in prolonged tennis matches may be affected by central fatigue. The purpose of this study was to investigate the supplementation of branched-chain amino acids (BCAA), arginine, and citrulline on tennis-specific perceptual-motor performance after a simulated match. Nine male tennis players consumed 0.17 g/kg BCAA, 0.05 g/kg arginine, and 0.05 g/kg citrulline (AA trial), or placebo (PB trial) 1 h before the match. In the perceptual-motor performance test before and after the match, the subjects hit balls to the opposite direction of the examiner's movement. The AA trial showed significantly higher rate of correct direction than the PB trial after the match (AA trial: 93.63 ± 1.28%, PB trial: 69.09 ± 2.40%). The AA trial also demonstrated significantly higher post-match accuracy and consistency than the PB trial. The AA trial showed significantly lower heart rate and ratings of perceive exertion during the match, concurrently with a significantly lower plasma total tryptophan/BCAA ratio. Similar post-match plasma NH3 concentrations were found in both trials while the AA trial was significantly higher in NOx concentration. This study suggested that the supplementation could prevent the decline in perceptual-motor performance through alleviation of central fatigue by BCAA and prevention of excess hyperammonemia by arginine and citrulline. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Citrullinated histone H3: a novel target for the treatment of sepsis.

    PubMed

    Li, Yongqing; Liu, Zhengcai; Liu, Baoling; Zhao, Ting; Chong, Wei; Wang, Yanming; Alam, Hasan B

    2014-08-01

    We have recently demonstrated that in a rodent model of lipopolysaccharide (LPS)-induced shock, an increase in circulating citrullinated histone H3 (Cit H3) is associated with lethality of sepsis, and treatment with suberoylanilide hydroxamic acid (SAHA), a histone deacetylase (HDAC) inhibitor (HDACI), significantly improves survival. However, the role of Cit H3 in pathogenesis and therapeutics of sepsis are largely unknown. The present study was designed to test whether treatment with HDACI could inhibit cellular Cit H3 production, and inhibition of peptidylarginine deiminase (PAD, an enzyme producing Cit H3) with Cl-amidine (PAD inhibitor) or neutralization of blood Cit H3 with anti-Cit H3 antibody could improve survival in a clinically relevant mouse model of cecal ligation and puncture (CLP)-induced septic shock. Three experiments were carried out. In experiment I, HL-60 neutrophilic cells grown on a coverslip were treated with LPS (100 ng/mL) in the presence or absence of SAHA (5 μmol) for 3 hours, and subjected to immunostaining with anti-Cit H3 antibody to assess effect of SAHA on Cit H3 production under a fluorescence microscope. The ratio of Cit H3 positive cells was calculated as mean values ± SD (n = 3). In experiment II, male C57BL/6J mice were subjected to CLP, and 1 hour later randomly divided into 2 groups for intraperitoneal injection as follows: (1) Dimethyl sulfoxide (DMSO), (2) SAHA (50 mg/kg) in DMSO, and (3) Cl-amidine (80 mg/kg) in DMSO (n = 10/group). In experiment III, male C57BL/6J mice were divided into control and treatment groups, and subjected to CLP. Two hours later, immunoglobulin (Ig)G and Cit H3 antibody (20 mg/kg IV; n = 5/group) were injected into the control and treatment groups, respectively. Survival was monitored for ≤10 days. In experiment I, LPS induced Cit H3 production in the HL-60 cells, and SAHA treatment inhibited H3 citrullination significantly (P < .05). In experiment II, all vehicle-injected mice died within 3

  19. Autoantibodies to citrullinated proteins induce joint pain independent of inflammation via a chemokine-dependent mechanism

    PubMed Central

    Wigerblad, Gustaf; Bas, Duygu B; Fernades-Cerqueira, Cátia; Krishnamurthy, Akilan; Rogoz, Katarzyna; Kato, Jungo; Sandor, Katalin; Su, Jie; Jimenez–Andrade, Juan Miguel; Finn, Anja; Bersellini Farinotti, Alex; Amara, Khaled; Lundberg, Karin; Holmdahl, Rikard; Jakobsson, Per-Johan; Malmström, Vivianne; Catrina, Anca I; Klareskog, Lars; Svensson, Camilla I

    2016-01-01

    Objective An interesting and so far unexplained feature of chronic pain in autoimmune disease is the frequent disconnect between pain and inflammation. This is illustrated well in rheumatoid arthritis (RA) where pain in joints (arthralgia) may precede joint inflammation and persist even after successful anti-inflammatory treatment. In the present study, we have addressed the possibility that autoantibodies against citrullinated proteins (ACPA), present in RA, may be directly responsible for the induction of pain, independent of inflammation. Methods Antibodies purified from human patients with RA, healthy donors and murinised monoclonal ACPA were injected into mice. Pain-like behaviour was monitored for up to 28 days, and tissues were analysed for signs of pathology. Mouse osteoclasts were cultured and stimulated with antibodies, and supernatants analysed for release of factors. Mice were treated with CXCR1/2 (interleukin (IL) 8 receptor) antagonist reparixin. Results Mice injected with either human or murinised ACPA developed long-lasting pronounced pain-like behaviour in the absence of inflammation, while non-ACPA IgG from patients with RA or control monoclonal IgG were without pronociceptive effect. This effect was coupled to ACPA-mediated activation of osteoclasts and release of the nociceptive chemokine CXCL1 (analogue to human IL-8). ACPA-induced pain-like behaviour was reversed with reparixin. Conclusions The data suggest that CXCL1/IL-8, released from osteoclasts in an autoantibody-dependent manner, produces pain by activating sensory neurons. The identification of this new pain pathway may open new avenues for pain treatment in RA and also in other painful diseases associated with autoantibody production and/or osteoclast activation. PMID:26613766

  20. Positive anti‐cyclic citrullinated proteins and rheumatoid factor during active lung tuberculosis

    PubMed Central

    Elkayam, O; Segal, R; Lidgi, M; Caspi, D

    2006-01-01

    Objectives To determine the prevalence of anti‐cyclic citrullinated proteins (anti‐CCP) and IgM rheumatoid factor (RF) in sera of patients with TB compared with healthy controls. Patients and methods 47 consecutive patients with recently diagnosed active pulmonary TB and 39 healthy controls were studied. Data were collected by questionnaire on clinical features of the disease, duration of symptoms, fever, cough, arthralgia, myalgia, sicca symptoms. Serum samples were collected from patients before starting treatment for TB and frozen at −20°C. Anti‐CCP and IgM RF were evaluated by ELISA. Results The mean (SD) duration of TB related symptoms was 4.4 (1.7) months, 73% had fever, 94% a cough. Rheumatic symptoms were relatively rare: arthralgia (4%), myalgias (4%), eye and mouth dryness (2% and 9%, respectively). Mean (SD) levels of anti‐CCP were significantly increased in patients with TB compared with controls: 44.9 (51) IU v 20 (7.3) IU (p = 0.002). Serum levels >40 U were found in 15/47 (32%) patients compared with 1/39 (2.6%) controls (p = 0.002). Mean (SD) serum levels of IgM RF were significantly increased in patients with TB: 17.8 (19) v 4.3 (5) (p<0.0001). IgM RF was positive (>6 IU) in 29/47 (62%) patients v 1/39 (2.6%) controls (p<0.0001). Conclusions A significant proportion of patients with active TB have an increased titre of anti‐CCP and IgM RF. PMID:16361276

  1. Citrulline uptake in rat cerebral cortex slices: modulation by Thioacetamide -Induced hepatic failure.

    PubMed

    Zielińska, Magdalena; Obara-Michlewska, Marta; Hilgier, Wojciech; Albrecht, Jan

    2014-12-01

    L-citrulline (Cit) is a co-product of NO synthesis and a direct L-arginine (Arg) precursor for de novo NO synthesis. Acute liver failure (ALF) is associated with increased nitric oxide (NO) and cyclic GMP (cGMP) synthesis in the brain, indirectly implicating a role for active transport of Cit. In the present study we characterized [(3)H]Cit uptake to the cortical brain slices obtained from control rats and rats with thioacetamide (TAA)-induced ALF ("TAA slices"). In both control and TAA slices the uptake was partially Na(+)-dependent and markedly inhibited by substrates of systems L and N, including L-glutamine (Gln), which accumulates in excess in brain during ALF. Cit uptake was not affected by Arg, the y(+)/y(+)L transport system substrate, nor by amino acids taken up by systems A, xc (-)or XAG. The Vmax of the uptake in TAA slices was ~60 % higher than in control slices. Chromatographic (HPLC) analysis revealed a ~30 % increase of Cit concentration in the cerebral cortical homogenates of TAA rats. The activity of argininosuccinate synthase (ASS) and argininosuccinate lyase (ASL), the two enzymes of Cit-NO cycle catalyzing synthesis of Arg, showed an increase in TAA rats, consistent with increased ASS and ASL protein expression, by ~30 and ~20 %, respectively. The increased Cit-NO cycle activity was paralleled by increased expression of mRNA coding for inducible nitric oxide synthase (iNOS). Taken together, the results suggest a role for Cit in the activation of cerebral NO synthesis during ALF.

  2. Anti-citrullinated peptide antibodies and their value for predicting responses to biologic agents: a review.

    PubMed

    Martin-Mola, Emilio; Balsa, Alejandro; García-Vicuna, Rosario; Gómez-Reino, Juan; González-Gay, Miguel Angel; Sanmartí, Raimon; Loza, Estíbaliz

    2016-08-01

    Anti-citrullinated peptide antibodies (ACPAs) play an important pathogenic role both at the onset and during the disease course. These antibodies precede the clinical appearance of rheumatoid arthritis (RA) and are associated with a less favorable prognosis, both clinically and radiologically. The objective of this work was to conduct a comprehensive review of studies published through September 2015 of ACPAs' role as a predictor of the therapeutic response to the biological agents in RA patients. The review also includes summary of the biology and detection of ACPAs as well as ACPAs in relation to joint disease and CV disease and the possible role of seroconversion. The reviews of studies examining TNF inhibitors and tocilizumab yielded negative results. In the case of rituximab, the data indicated a greater probability of clinical benefit in ACPA(+) patients versus ACPA(-) patients, as has been previously described for rheumatoid factor. Nonetheless, the effect is discreet and heterogeneous. Another drug that may have greater effectiveness in ACPA(+) patients is abatacept. Some studies have suggested that the drug is more efficient in ACPA(+) patients and that those patients show greater drug retention. In a subanalysis of the AMPLE trial, patients with very high ACPA titers who were treated with abatacept had a statistically significant response compared to patients with lower titers. In summary, the available studies suggest that the presence of or high titers of ACPA may predict a better response to rituximab and/or abatacept. Evidence regarding TNFi and tocilizumab is lacking. However, there is a lack of studies with appropriate designs to demonstrate that some drugs are superior to others for ACPA(+) patients.

  3. The clinical significance of antibody determination to cyclic citrullinated peptides in systemic sclerosis.

    PubMed

    Stamenković, Bojana; Stanković, Aleksandra; Dimić, Aleksandar; Damjanov, Nemanja; Nedović, Jovan; Stojanović, Sonja; Savić, Vojin; Djordjević, Dragan

    2012-01-01

    Anti-citrullinated peptides antibodies (ACPA) are present in 80% of sera of rheumatoid arthritis (RA) patients with high specificity for diagnosis and prediction for the development of early erosive arthritis. A few studies have reported a low frequency ACPA in systemic sclerosis (SSc) patients with the presence of arthritis. The aim of our study was to determine the frequency of ACPA in systemic sclerosis (SSc) patients, their correlation with clinical manifestations and radiographic features. The study included 82 patients with SSc, mean age 54.4 years, 59 with the limited (ISSc) and 23 with the diffuse (dSSc) form of the disease. The control group included 28 healthy age and sex matched subjects. ACPA and rheumatoid factor (RF) were determined in all SSc patients and healthy subjects in whom standard radiography of hands and wrists was also done. The presence of ACPA was detected in 11 (13.4%) of SSc patients. Their level was not increased in any of the controls. Positive RF was found in 15.9% of SSc patients. Arthritis was present in 17.1%, as well as marginal bone erosions. There was a statistically significant association between positive ACPA and arthritis (p < 0.0001) and positive ACPA and marginal bone erosions (p = 0.0002). The research confirmed the correlation between ACPA with clinical signs of arthritis and radiographic damage of hand joints. ACPA is a useful diagnostic marker in the identification of SSc patients with arthritis and anatomic bone damage enabling the use of adequate therapy in order to prevent joint damage and poor quality of life.

  4. Serum citrulline as a biomarker of gastrointestinal function during hematopoietic cell transplantation (HCT) in children

    PubMed Central

    Gosselin, Kerri B.; Feldman, Henry A.; Sonis, Andrew L.; Bechard, Lori J.; Kellogg, Mark D.; Gura, Kathleen; Venick, Robert; Gordon, Catherine M.; Guinan, Eva C.; Duggan, Christopher

    2014-01-01

    Objective We sought to determine if serum citrulline (CIT), an amino acid produced by small bowel enterocytes, was associated with clinical and biochemical markers of gastrointestinal function in children undergoing hematopoietic cell transplantation (HCT). Methods We conducted a multi-center, prospective cohort study of 26 children to define time-related changes in serum CIT over the course of HCT. Markers of gastrointestinal function including oral energy intake, emesis, stool volume, presence of graft-versus-host disease (GVHD), oral mucositis severity, and cytokine and neurohormone levels were measured. Weekly serum CIT concentrations were obtained from 10 days prior until 30 days after HCT. Results Mean baseline CIT concentration was 22.7 µmol/L (95% CI 17.7 – 27.6) on day −10, which decreased to a nadir of 7.5 µmol/L (95% CI 3.1 – 18.0, p = 0.017) on day +8 following HCT before returning to baseline by day 30. After adjustment for IL-6 level (1.0% lower CIT per 10% increase in IL-6, p=0.004), presence of acute graft-versus-host disease (GVHD), (27% lower CIT, p=0.025) and oral energy intake (2.1% lower CIT per 10% decrease in energy intake, p=0.018), the nadir shifted to day +10, when mean CIT concentration was lower in patients with severe oral mucositis (6.7 µmol/L, 95% CI 3.4–13.1) than in those without severe mucositis (11.9 µmol/L, 95% CI 5.8–24.4, p=0.003). Change in CIT was not correlated with stool volume, C-reactive protein, TNF-alpha, leptin, or ghrelin. Conclusion In children undergoing HCT, serum CIT correlates with measures of gastrointestinal function (oral mucositis severity, dietary intake, acute GVHD) and may reflect mucosal injury to the gastrointestinal tract. PMID:24614125

  5. Identification of Natural Bispecific Antibodies against Cyclic Citrullinated Peptide and Immunoglobulin G in Rheumatoid Arthritis

    PubMed Central

    Wang, Wei; Li, Jinming

    2011-01-01

    Background Previous studies indicate that natural bispecific antibodies can be readily produced in vivo when the body is simultaneously stimulated with 2 distinct antigens. Patients with rheumatoid arthritis (RA) usually exhibit persistent immune responses to various autoantigens, raising the possibility that natural bispecific antibodies against 2 distinct autoantigens might exist. Methodology/Principal Findings We identified the presence of natural bispecific antibodies against cyclic citrullinated peptide (CCP) and immunoglobulin G (IgG) in RA patients' sera by means of a double-antigen sandwich enzyme-linked immunosorbent assay (ELISA). The spontaneous emergence of bispecific antibodies was confirmed by mixing different proportions of 1 anti-CCP-positive serum and 1 rheumatoid factor (RF)-positive serum in vitro. Among the tested samples, positive correlations were found between the presence of bispecific antibodies and both IgG4 anti-CCP antibodies and IgG4 RF (r = 0.507, p<0.001 and r = 0.249, p = 0.044, respectively), suggesting that the IgG4 subclass is associated with this phenomenon. Furthermore, bispecific antibodies were selectively generated when several anti-CCP- and RF-positive sera were mixed pairwise, indicating that factors other than the monospecific antibody titers may also contribute to the production of the natural bispecific antibodies. Conclusions/Significance We successfully identified the presence of natural bispecific antibodies. Our results suggest that these antibodies originate from anti-CCP and RF in the sera of RA patients. The natural occurrence of bispecific antibodies in human diseases may provide new insights for a better understanding of the diseases. Further investigations are needed to elucidate their precise generation mechanisms and explore their clinical significance in disease development and progression in a larger study population. PMID:21304585

  6. Genetic markers of rheumatoid arthritis susceptibility in anti-citrullinated peptide antibody negative patients

    PubMed Central

    Viatte, Sebastien; Plant, Darren; Bowes, John; Lunt, Mark; Eyre, Stephen; Barton, Anne; Worthington, Jane

    2012-01-01

    Introduction There are now over 30 confirmed loci predisposing to rheumatoid arthritis (RA). Studies have been largely undertaken in patients with anticyclic citrullinated peptide (anti-CCP) positive RA, and some genetic associations appear stronger in this subgroup than in anti-CCP negative disease, although few studies have had adequate power to address the question. The authors therefore investigated confirmed RA susceptibility loci in a large cohort of anti-CCP negative RA subjects. Methods RA patients and controls, with serological and genetic data, were available from UK Caucasian patients (n=4068 anti-CCP positive, 2040 anti-CCP negative RA) and 13,009 healthy controls. HLA-DRB1 genotypes and 36 single nucleotide polymorphisms were tested for association between controls and anti-CCP positive or negative RA. Results The shared epitope (SE) showed a strong association with anti-CCP positive and negative RA, although the effect size was significantly lower in the latter (effect size ratio=3.18, p<1.0E-96). A non-intronic marker at TNFAIP3, GIN1/C5orf30, STAT4, ANKRD55/IL6ST, BLK and PTPN22 showed association with RA susceptibility, irrespective of the serological status, the latter three markers remaining significantly associated with anti-CCP negative RA, after correction for multiple testing. No significant association with anti-CCP negative RA was detected for other markers (eg, AFF3, CD28, intronic marker at TNFAIP3), though the study power for those markers was over 80%. Discussion In the largest sample size studied to date, the authors have shown that the strength of association, the effect size and the number of known RA susceptibility loci associated with disease is different in the two disease serotypes, confirming the hypothesis that they might be two genetically different subsets. PMID:22661644

  7. Pattern of drugs use and association with anti-mutated citrullinated vimentin antibody in rheumatoid arthritis

    PubMed Central

    Safi, Mohammad-Ayman A.; Fathaldin, Omar A.

    2015-01-01

    Objectives: To demonstrate the pattern of disease-modifying antirheumatic drugs (DMARDs) use in Saudi and non-Saudi rheumatoid arthritis (RA) patients, and to evaluate the association of DMARDs use with anti-mutated citrullinated vimentin (anti-MCV) positivity and other factors. Methods: Retrospectively, for a period of 7 years (2007-2014), we studied 205 RA patients, at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. All patients used DMARDs. Pattern of use for all 6 DMARDs was almost the same among Saudis and non-Saudis with no significant difference (p>0.05) for each DMARD; MTX was the most commonly used DMARD (71-76%). Results: There was no association between anti-MCV positivity and different DMARDs use. Methotrexate was used 76 times as combination, scoring the highest in this respect. There was a significant correlation (p<0.05) between Plaquenil with Methotrexate and with Sulfasalazine; Leflunomide with anti-TNF and with Prednisolone; age with Methotrexate and with Plaquenil; anti-MCV positivity with Prednisolone. Saudi/non-Saudi status showed no correlation with all factors or drugs. There was no significant association between DMARDs and comorbidity. Conclusion: Similar to worldwide results, MTX was the most commonly used DMARD; with the addition of anti-TNF to increase the effect, and folic acid to minimize the side effects. In this cohort, the pattern of use for all DMARDs was similar among Saudis and non-Saudis; treatment depended neither on anti-MCV positivity nor on the presence of comorbid conditions. A study of the association of DMARDs with disease activity is recommended. PMID:25737174

  8. Citrulline/malate promotes aerobic energy production in human exercising muscle

    PubMed Central

    Bendahan, D; Mattei, J; Ghattas, B; Confort-Gouny, S; Le Guern, M E; Cozzone, P

    2002-01-01

    Background: Previous studies have shown an antiasthenic effect of citrulline/malate (CM) but the mechanism of action at the muscular level remains unknown. Objective: To investigate the effects of CM supplementation on muscle energetics. Methods: Eighteen men complaining of fatigue but with no documented disease were included in the study. A rest-exercise (finger flexions)-recovery protocol was performed twice before (D-7 and D0), three times during (D3, D8, D15), and once after (D22) 15 days of oral supplementation with 6 g/day CM. Metabolism of the flexor digitorum superficialis was analysed by 31P magnetic resonance spectroscopy at 4.7 T. Results: Metabolic variables measured twice before CM ingestion showed no differences, indicating good reproducibility of measurements and no learning effect from repeating the exercise protocol. CM ingestion resulted in a significant reduction in the sensation of fatigue, a 34% increase in the rate of oxidative ATP production during exercise, and a 20% increase in the rate of phosphocreatine recovery after exercise, indicating a larger contribution of oxidative ATP synthesis to energy production. Considering subjects individually and variables characterising aerobic function, extrema were measured after either eight or 15 days of treatment, indicating chronological heterogeneity of treatment induced changes. One way analysis of variance confirmed improved aerobic function, which may be the result of an enhanced malate supply activating ATP production from the tricarboxylic acid cycle through anaplerotic reactions. Conclusion: The changes in muscle metabolism produced by CM treatment indicate that CM may promote aerobic energy production. PMID:12145119

  9. A Critical Reappraisal of Neutrophil Extracellular Traps and NETosis Mimics Based on Differential Requirements for Protein Citrullination

    PubMed Central

    Konig, Maximilian F.; Andrade, Felipe

    2016-01-01

    NETosis, an antimicrobial form of neutrophil cell death, is considered a primary source of citrullinated autoantigens in rheumatoid arthritis (RA) and immunogenic DNA in systemic lupus erythematosus (SLE). Activation of the citrullinating enzyme peptidylarginine deiminase type 4 (PAD4) is believed to be essential for neutrophil extracellular trap (NET) formation and NETosis. PAD4 is therefore viewed as a promising therapeutic target to inhibit the formation of NETs in both diseases. In this review, we examine the evidence for PAD4 activation during NETosis and provide experimental data to suggest that protein citrullination is not a universal feature of NETs. We delineate two distinct biological processes, leukotoxic hypercitrullination (LTH) and defective mitophagy, which have been erroneously classified as “NETosis.” While these NETosis mimics share morphological similarities with NETosis (i.e., extracellular DNA release), they are biologically distinct. As such, these processes can be readily classified by their stimuli, activation of distinct biochemical pathways, the presence of hypercitrullination, and antimicrobial effector function. NETosis is an antimicrobial form of cell death that is NADPH oxidase-dependent and not associated with hypercitrullination. In contrast, LTH is NADPH oxidase-independent and not bactericidal. Rather, LTH represents a bacterial strategy to achieve immune evasion. It is triggered by pore-forming pathways and equivalent signals that cumulate in calcium-dependent hyperactivation of PADs, protein hypercitrullination, and neutrophil death. The generation of citrullinated autoantigens in RA is likely driven by LTH, but not NETosis. Mitochondrial DNA (mtDNA) expulsion, the result of a constitutive defect in mitophagy, represents a second NETosis mimic. In the presence of interferon-α and immune complexes, this process can generate highly interferogenic oxidized mtDNA, which has previously been mistaken for NETosis in SLE

  10. Higher Levels of Autoantibodies Targeting Mutated Citrullinated Vimentin in Patients with Psoriatic Arthritis Than in Patients with Psoriasis Vulgaris

    PubMed Central

    Dalmády, Szandra; Kiss, Mária; Képíró, László; Kovács, László; Sonkodi, Gábor; Kemény, Lajos; Gyulai, Rolland

    2013-01-01

    Antibodies against citrullinated proteins/peptides (ACPAs), and especially antibodies targeting mutated citrullinated vimentin (anti-MCVs), are novel biomarkers of rheumatoid arthritis (RA). Whereas ACPAs are specific and sensitive markers for RA, there have hardly been any reports relating to ACPAs in psoriatic arthritis (PsA) or in psoriasis without joint symptoms (PsO). The aim of the present study was to investigate the prevalence of anti-MCVs in PsA and PsO. Serum anti-MCV titers were measured in 46 PsA and 42 PsO patients and in 40 healthy controls by means of a commercial enzyme-linked immunosorbent assay. The potential correlations of the serum autoantibody levels with several clinical and laboratory parameters were examined. The anti-MCV levels in the PsA patients were significantly higher than those in the PsO group. Among the clinical variables, the presence of tender knee joints and nail psoriasis was significantly associated with anti-MCV positivity in the PsA patients. Higher anti-MCV titers in the PsO patients were associated with a more severe disease course and with the early onset of psoriatic skin symptoms. Our results suggest that anti-MCVs can be used as novel markers in the diagnosis of PsA and in a subset of PsO patients. PMID:23573111

  11. Indications and contraindications for infusing specific amino acids (leucine, glutamine, arginine, citrulline, and taurine) in critical illness.

    PubMed

    Ginguay, Antonin; De Bandt, Jean-Pascal; Cynober, Luc

    2016-03-01

    The review assesses the utility of supplementing parenteral or enteral nutrition of ICU patients with each of five specific amino acids that display pharmacological properties. Specifying indications implies also stating contraindications.Combined supplementation of amino acids with ω3-fatty acids and/or trace elements (immune-enhancing diets) will not be considered in this review because these mixtures do not allow the role of amino acids in the effect (positive or negative) of the mixture to be isolated, and so cannot show whether or not supplementation of a given amino acid is indicated. After decades of unbridled use of glutamine (GLN) supplementation in critically ill patients, recent large trials have brought a note of caution, indicating for example that GLN should not be used in patients with multiple organ failure. Yet these large trials do not change the conclusions of recent meta-analyses. Arginine (ARG), as a single dietary supplement, is probably not harmful in critical illness, in particular in a situation of ARG deficiency syndrome with low nitric oxide production. Citrulline supplementation strongly improves microcirculation in animal models with gut injury, but clinical studies are lacking. Taurine has a potent protective effect against ischemic reperfusion injury. Amino acid-based pharmaconutrition has displayed familiar 'big project' stages: enthusiasm (citrulline and taurine), doubt (GLN), hunt for the guilty (ARG), and backpedalling (leucine). Progress in this field is very slow, and sometimes gives way to retreat, as demonstrated by recent large trials on GLN supplementation.

  12. Are plasma citrulline and glutamine biomarkers of intestinal absorptive function in patients with short bowel syndrome?

    PubMed

    Luo, Menghua; Fernández-Estívariz, Concepción; Manatunga, Amita K; Bazargan, Niloofar; Gu, Li H; Jones, Dean P; Klapproth, Jan-Michael; Sitaraman, Shanthi V; Leader, Lorraine M; Galloway, John R; Ziegler, Thomas R

    2007-01-01

    Sensitive biomarkers for intestinal absorptive function would be clinically useful in short bowel syndrome (SBS). Citrulline (Cit) is a product of the metabolism of glutamine (Gln) and derived amino acids by enterocytes. Cit is produced almost exclusively by the gut, which is also a major site of Gln metabolism. The goals of this study were to examine whether plasma Cit and Gln concentrations are biomarkers of residual small intestinal length and nutrient absorptive functions in adult SBS patients followed prospectively. We studied 24 stable adults with severe SBS receiving chronic parenteral nutrition (PN) in a double-blind, randomized trial of individualized dietary modification +/- recombinant human growth hormone (GH). During a baseline week, intestinal absorption studies (% absorption of fluid, kcal, nitrogen, fat, carbohydrate, sodium, phosphorus, and magnesium) were performed and concomitant plasma Cit and Gln concentrations determined. Individualized dietary modification and treatment with subcutaneous injection of placebo (n = 9) or GH (0.1 mg/kg daily x 21 days, then 3 times/week; n = 15) were then begun. PN weaning was initiated after week 4 and continued as tolerated for 24 weeks. Repeat plasma amino acid determination and nutrient absorption studies were performed at weeks 4 and 12. Residual small bowel length at baseline was positively correlated with baseline plasma Cit (r = 0.467; p = .028). However, no significant correlations between absolute Cit or Gln concentrations and the percent absorption of nutrient substrates at any time point were observed. Similarly, no correlation between the change in Cit or GLN concentration and the change in % nutrient absorption was observed (baseline vs weeks 4 and 12, respectively). By weeks 12 and 24, 7 and 13 subjects were weaned completely from PN, respectively. However, baseline plasma Cit or Gln did not predict PN weaning at these time points. We concluded that plasma Cit (but not Gln) concentrations appeared

  13. Citrulline and Nonessential Amino Acids Prevent Fructose-Induced Nonalcoholic Fatty Liver Disease in Rats.

    PubMed

    Jegatheesan, Prasanthi; Beutheu, Stéphanie; Ventura, Gabrielle; Nubret, Esther; Sarfati, Gilles; Bergheim, Ina; De Bandt, Jean-Pascal

    2015-10-01

    Fructose induces nonalcoholic fatty liver disease (NAFLD). Citrulline (Cit) may exert a beneficial effect on steatosis. We compared the effects of Cit and an isonitrogenous mixture of nonessential amino acids (NEAAs) on fructose-induced NAFLD. Twenty-two male Sprague Dawley rats were randomly assigned into 4 groups (n = 4-6) to receive for 8 wk a 60% fructose diet, either alone or supplemented with Cit (1 g · kg(-1) · d(-1)), or an isonitrogenous amount of NEAAs, or the same NEAA-supplemented diet with starch and maltodextrin instead of fructose (controls). Nutritional and metabolic status, liver function, and expression of genes of hepatic lipid metabolism were determined. Compared with controls, fructose led to NAFLD with significantly higher visceral fat mass (128%), lower lean body mass (-7%), insulin resistance (135%), increased plasma triglycerides (TGs; 67%), and altered plasma amino acid concentrations with decreased Arg bioavailability (-27%). This was corrected by both NEAA and Cit supplementation. Fructose caused a 2-fold increase in the gene expression of fatty acid synthase (Fas) and 70% and 90% decreases in that of carnitine palmitoyl-transferase 1a and microsomal TG transfer protein via a nearly 10-fold higher gene expression of sterol regulatory element-binding protein-1c (Srebp1c) and carbohydrate-responsive element-binding protein (Chrebp), and a 90% lower gene expression of peroxisome proliferator-activated receptor α (Ppara). NEAA or Cit supplementation led to a Ppara gene expression similar to controls and decreased those of Srebp1c and Chrebp in the liver by 50-60%. Only Cit led to Fas gene expression and Arg bioavailability similar to controls. In our rat model, Cit and NEAAs effectively prevented fructose-induced NAFLD. On the basis of literature data and our findings, we propose that NEAAs may exert their effects specifically on the liver, whereas Cit presumably acts at both the hepatic and whole-body level, in part via improved

  14. Dysregulation of PAD4-mediated citrullination of nuclear GSK3β activates TGF-β signaling and induces epithelial-to-mesenchymal transition in breast cancer cells

    PubMed Central

    Stadler, Sonja C.; Vincent, C. Theresa; Fedorov, Victor D.; Patsialou, Antonia; Cherrington, Brian D.; Wakshlag, Joseph J.; Mohanan, Sunish; Zee, Barry M.; Zhang, Xuesen; Garcia, Benjamin A.; Condeelis, John S.; Brown, Anthony M. C.; Coonrod, Scott A.; Allis, C. David

    2013-01-01

    Peptidylarginine deiminase 4 (PAD4) is a Ca2+-dependent enzyme that converts arginine and methylarginine residues to citrulline, with histone proteins being among its best-described substrates to date. However, the biological function of this posttranslational modification, either in histones or in nonhistone proteins, is poorly understood. Here, we show that PAD4 recognizes, binds, and citrullinates glycogen synthase kinase-3β (GSK3β), both in vitro and in vivo. Among other functions, GSK3β is a key regulator of transcription factors involved in tumor progression, and its dysregulation has been associated with progression of human cancers. We demonstrate that silencing of PAD4 in breast cancer cells leads to a striking reduction of nuclear GSK3β protein levels, increased TGF-β signaling, induction of epithelial-to-mesenchymal transition, and production of more invasive tumors in xenograft assays. Moreover, in breast cancer patients, reduction of PAD4 and nuclear GSK3β is associated with increased tumor invasiveness. We propose that PAD4-mediated citrullination of GSK3β is a unique posttranslational modification that regulates its nuclear localization and thereby plays a critical role in maintaining an epithelial phenotype. We demonstrate a dynamic and previously unappreciated interplay between histone-modifying enzymes, citrullination of nonhistone proteins, and epithelial-to-mesenchymal transition. PMID:23818587

  15. Dysregulation of PAD4-mediated citrullination of nuclear GSK3β activates TGF-β signaling and induces epithelial-to-mesenchymal transition in breast cancer cells.

    PubMed

    Stadler, Sonja C; Vincent, C Theresa; Fedorov, Victor D; Patsialou, Antonia; Cherrington, Brian D; Wakshlag, Joseph J; Mohanan, Sunish; Zee, Barry M; Zhang, Xuesen; Garcia, Benjamin A; Condeelis, John S; Brown, Anthony M C; Coonrod, Scott A; Allis, C David

    2013-07-16

    Peptidylarginine deiminase 4 (PAD4) is a Ca(2+)-dependent enzyme that converts arginine and methylarginine residues to citrulline, with histone proteins being among its best-described substrates to date. However, the biological function of this posttranslational modification, either in histones or in nonhistone proteins, is poorly understood. Here, we show that PAD4 recognizes, binds, and citrullinates glycogen synthase kinase-3β (GSK3β), both in vitro and in vivo. Among other functions, GSK3β is a key regulator of transcription factors involved in tumor progression, and its dysregulation has been associated with progression of human cancers. We demonstrate that silencing of PAD4 in breast cancer cells leads to a striking reduction of nuclear GSK3β protein levels, increased TGF-β signaling, induction of epithelial-to-mesenchymal transition, and production of more invasive tumors in xenograft assays. Moreover, in breast cancer patients, reduction of PAD4 and nuclear GSK3β is associated with increased tumor invasiveness. We propose that PAD4-mediated citrullination of GSK3β is a unique posttranslational modification that regulates its nuclear localization and thereby plays a critical role in maintaining an epithelial phenotype. We demonstrate a dynamic and previously unappreciated interplay between histone-modifying enzymes, citrullination of nonhistone proteins, and epithelial-to-mesenchymal transition.

  16. Asymmetric Dimethylarginine Is a Well Established Mediating Risk Factor for Cardiovascular Morbidity and Mortality—Should Patients with Elevated Levels Be Supplemented with Citrulline?

    PubMed Central

    McCarty, Mark F.

    2016-01-01

    The arginine metabolite asymmetric dimethylarginine (ADMA) is a competitive inhibitor and uncoupler of endothelial nitric oxide synthase (eNOS), an enzyme that acts in multifarious ways to promote cardiovascular health. This phenomenon likely explains, at least in part, why elevated ADMA has been established as an independent risk factor for cardiovascular events, ventricular hypertrophy, and cardiovascular mortality. Fortunately, the suppressive impact of ADMA on eNOS activity can be offset by increasing intracellular arginine levels with supplemental citrulline. Although the long-term impact of supplemental citrulline on cardiovascular health in patients with elevated ADMA has not yet been studied, shorter-term clinical studies of citrulline administration demonstrate effects suggestive of increased NO synthesis, such as reductions in blood pressure and arterial stiffness, improved endothelium-dependent vasodilation, increased erection hardness, and increased ejection fractions in patients with heart failure. Supplemental citrulline could be a practical option for primary or secondary prevention of cardiovascular events and mortality, as it is inexpensive, has a mild flavor, and is well tolerated in doses (3–6 g daily) that can influence eNOS activity. Large and long-term clinical trials, targeting patients at high risk for cardiovascular events in whom ADMA is elevated, are needed to evaluate citrulline’s potential for aiding cardiovascular health. PMID:27417628

  17. Biochemical, physiological, and performance response of a functional watermelon juice enriched in L-citrulline during a half-marathon race

    PubMed Central

    Martínez-Sánchez, Ascensión; Ramos-Campo, Domingo J.; Fernández-Lobato, Bárbara; Rubio-Arias, Jacobo A.; Alacid, Fernando; Aguayo, Encarna

    2017-01-01

    ABSTRACT Background: Watermelon is a rich natural source of l-citrulline. This non-essential amino acid increases exercise performance. Objective: Evaluate the effect of Fashion watermelon juice enriched in l-citrulline (CWJ) (3.45 g per 500 mL) in physical performance and biochemical markers after a half-marathon race. Design: A randomised, double blind, crossover design where 2 h after drinking 500 mL of CWJ or placebo (PLA, beverage without l-citrulline) amateur male runners performed two half-marathon races. Jump height, heart rate and rating of perceived exertion were evaluated before and after the races. Moreover, muscle soreness and plasma markers of muscle damage and metabolism were evaluated for 72 h after the races. Results: Muscle soreness perception was significantly lower from 24 to 72 h after the race with CWJ beverage. Immediately after the races, runners under CWJ condition showed plasma lactate and glucose concentrations significantly lower and higher lactate dehydrogenase and l-arginine concentration than runners under PLA. A maintenance of jump heights after the races under CWJ supplementation was found, decreasing significantly with PLA. Conclusion: A single Fashion watermelon juice enriched in l-citrulline dose diminished muscle soreness perception from 24 to 72 h after the race and maintained lower concentrations of plasma lactate after an exhausting exercise. PMID:28659740

  18. Identification and functional characterization of T cells reactive to citrullinated-vimentin in HLA-DRB1*0401 humanized mice and RA patients

    PubMed Central

    Snir, Omri; Rieck, Mary; Gebe, John A.; Yue, Betty B.; Rawlings, Crystal A.; Nepom, Gerald; Malmström, Vivianne; Buckner, Jane H.

    2011-01-01

    Objective Antibodies towards the citrullinated form of the synovial antigen vimentin are specific for rheumatoid arthritis (RA) and associated with HLADRB1*0401. This suggests that T cells specific for peptides derived from citrullinated-vimentin presented in the context of HLA-DRB1*0401 may contribute to the etiopathogenesis of RA. Here, we aimed to identify immunodominant epitopes from citrullinated-vimentin presented by HLADRB1*0401 and characterize the resulting T cell responses. Methods We first predicted an HLA-binding T cell epitope from citrullinated vimentin based on the binding motif of DRB1*0401, and then confirmed its affinity. An MHC class-II tetramer loaded with cit-vim59-78 was constructed and used to screen for specific T cells in DRB1*0401 transgenic mice, RA patients and healthy controls. Additionally, the cytokine output following cit-vim59-78 challenge was analyzed in patients and healthy subjects by multicolor flow cytometry and luminex-based analysis. Results The citrullinated form of vim59-78 bound to HLA-DRB1*0401 while the native version could not. Subsequently, cit-vim59-78-specific T cells were detected in immunized mice and in the periphery of both HLA-DR*0401 healthy controls and RA subjects, using MHC class-II tetramers, CD154 upregulation and intracellular cytokine measurements. Cell culture supernatants demonstrated an enhanced production of cytokines, most prominent of which was IFNγ from RA-derived cells in response to cit-vim59-78 in comparison to healthy controls. Conclusions Here, we describe a posttranslational modification of an RA candidate autoantigen towards which DRB1*0401-restricted, T cells can be found in both RA patients and healthy controls, but for which a proinflammatory response is uniquely found among subjects with RA. PMID:21567378

  19. Citrulline decreases hepatic endotoxin-induced injury in fructose-induced non-alcoholic liver disease: an ex vivo study in the isolated perfused rat liver.

    PubMed

    Ouelaa, Wassila; Jegatheesan, Prasanthi; M'bouyou-Boungou, Japhète; Vicente, Christelle; Nakib, Samir; Nubret, Esther; De Bandt, Jean-Pascal

    2017-06-01

    Steatosis can sensitise the liver to various challenges and favour the development of non-alcoholic fatty liver disease (NAFLD). In this context, fructose feeding promotes endotoxin translocation from the gut, contributing to disease progression via an inflammatory process. Citrulline is protective against fructose-induced NAFLD; we hypothesised that this property might be related to its anti-inflammatory and antioxidative action against endotoxin-induced hepatic injuries. This hypothesis was evaluated in a model of perfused liver isolated from NAFLD rats. Male Sprague-Dawley rats (n 30) were fed either a standard rodent chow or a 60 % fructose diet alone, or supplemented with citrulline (1 g/kg per d) for 4 weeks. After an evaluation of their metabolic status, fasted rats received an intraperitoneal injection of lipopolysaccharide (LPS) (2·5 mg/kg). After 1 h, the livers were isolated and perfused for 1 h to study liver function and metabolism, inflammation and oxidative status. In vivo, citrulline significantly decreased dyslipidaemia induced by a high-fructose diet and insulin resistance. In the isolated perfused rat livers, endotoxaemia resulted in higher cytolysis (alanine aminotransferase release) and higher inflammation (Toll-like receptor 4) in livers of fructose-fed rats, and it was prevented by citrulline supplementation. Oxidative stress and antioxidative defences were similar in all three groups. Amino acid exchanges and metabolism (ammonia and urea release) were only slightly different between the three groups. In this context of mild steatosis, our results suggest that fructose-induced NAFLD leads to an increased hepatic sensitivity to LPS-induced inflammation. Citrulline-induced restriction of the inflammatory process may thus contribute to the prevention of NAFLD.

  20. L-citrulline immunoreactivity reveals nitric oxide production in the electromotor and electrosensory systems of the weakly electric fish, Apteronotus leptorhynchus.

    PubMed

    Smith, G Troy; Allen, Antiño R; Oestreich, Jorg; Gammie, Stephen C

    2005-01-01

    Weakly electric fish produce electric organ discharges (EODs) used for electrolocation and communication. In the brown ghost knifefish, Apteronotus leptorhynchus, several neuron types in brain regions that control the EOD or process electrosensory information express nitric oxide synthase (NOS). The present study used immunoreactivity for L-citrulline, a byproduct of the production of nitric oxide (NO) by NOS, to assess NO production in NOS-expressing neurons. A polyclonal antibody against L-citrulline produced specific labeling in most neuronal populations previously identified to express NOS. Specifically, several cell types that precisely encode temporal information and/or fire at high frequencies, including spherical cells in the electrosensory lateral line lobe, giant cells in layer VI of the dorsal torus semicircularis, and pacemaker and relay cells in the pacemaker nucleus, were strongly immunoreactive for L-citrulline. This suggests that these neurons produced high levels of NO. Notably, electromotor neurons, which also strongly express NOS, were not immunoreactive for L-citrulline, suggesting that NOS did not produce high levels of NO in these neurons. No apparent differences in L-citrulline distribution or intensity were observed between socially isolated fish and fish exposed to playback stimuli simulating the presence of a conspecific. This suggests that social stimulation by electrocommunication signals is not necessary for high levels of NO production in many NOS-positive neurons. Future studies focusing on regulation of NO production in these systems, and the effects of NO on electrosensory processing and electromotor pattern generation will help elucidate the function of NO signaling pathways in this system.

  1. Preventing and curing citrulline-induced autoimmune arthritis in a humanized mouse model using a Th2-polarizing iNKT cell agonist.

    PubMed

    Walker, Kyle M; Rytelewski, Mateusz; Mazzuca, Delfina M; Meilleur, Shannon A; Mannik, Lisa A; Yue, David; Brintnell, William C; Welch, Ian; Cairns, Ewa; Haeryfar, S M Mansour

    2012-07-01

    Invariant natural killer T (iNKT) cells are innate lymphocytes with unique reactivity to glycolipid antigens bound to non-polymorphic CD1d molecules. They are capable of rapidly releasing pro- and/or anti-inflammatory cytokines and constitute attractive targets for immunotherapy of a wide range of diseases including autoimmune disorders. In this study, we have explored the beneficial effects of OCH, a Th2-polarizing glycolipid agonist of iNKT cells, in a humanized mouse model of rheumatoid arthritis (RA) in which citrullinated human proteins are targeted by autoaggressive immune responses in mice expressing an RA susceptibility human leukocyte antigen (HLA) DR4 molecule. We found for the first time that treatment with OCH both prevents and cures citrulline-induced autoimmune arthritis as evidenced by resolved ankle swelling and reversed histopathological changes associated with arthritis. Also importantly, OCH treatment blocked the arthritogenic capacity of citrullinated antigen-experienced splenocytes without compromising their global responsiveness or altering the proportion of splenic naturally occurring CD4(+)CD25(+)FoxP3(+) regulatory T cells. Interestingly, administering the Th1-promoting iNKT cell glycolipid ligand α-C-galactosylceramide into HLA-DR4 transgenic mice increased the incidence of arthritis in these animals and exacerbated their clinical symptoms, strongly suggesting a role for Th1 responses in the pathogenesis of citrulline-induced arthritis. Therefore, our findings indicate a role for Th1-mediated immunopathology in citrulline-induced arthritis and provide the first evidence that iNKT cell manipulation by Th2-skewing glycolipids may be of therapeutic value in this clinically relevant model, a finding that is potentially translatable to human RA.

  2. Periodontitis increases rheumatic factor serum levels and citrullinated proteins in gingival tissues and alter cytokine balance in arthritic rats

    PubMed Central

    Corrêa, Mônica G.; Sacchetti, Silvana B.; Ribeiro, Fernanda Vieira; Pimentel, Suzana Peres; Casarin, Renato Corrêa Viana; Cirano, Fabiano Ribeiro; Casati, Marcio Z.

    2017-01-01

    This study investigated some immunological features by experimental periodontitis (EP) and rheumatoid arthritis (RA) disease interact in destructive processes in arthritic rats. Rats were assigned to the following groups: EP +RA; RA; EP; and Negative Control. RA was induced by immunizations with type-II collagen and a local immunization with Complete Freund’s adjuvant in the paw. Periodontitis was induced by ligating the right first molars. The serum level of rheumatoid factor (RF) and anti-citrullinated protein antibody (ACCPA) were measured before the induction of EP (T1) and at 28 days after (T2) by ELISA assay. ACCPA levels were also measured in the gingival tissue at T2. The specimens were processed for morphometric analysis of bone loss, and the gingival tissue surrounding the first molar was collected for the quantification of interleukin IL-1β, IL-4, IL-6, IL-17 and TNF-α using a Luminex/MAGpix assay. Paw edema was analyzed using a plethysmometer. Periodontitis increased the RF and ACCPA levels in the serum and in the gingival tissue, respectively. Besides, the level of paw swelling was increased by EP and remained in progress until the end of the experiment, when EP was associated with RA. Greater values of IL-17 were observed only when RA was present, in spite of PE. It can be concluded that periodontitis increases rheumatic factor serum levels and citrullinated proteins level in gingival tissues and alter cytokine balance in arthritic rats; at the same time, arthritis increases periodontal destruction, confirming the bidirectional interaction between diseases. PMID:28358812

  3. The effect of targeted rheumatoid arthritis therapies on anti-citrullinated protein autoantibody levels and B cell responses

    PubMed Central

    Modi, S; Soejima, M; Levesque, M C

    2013-01-01

    Rheumatoid arthritis (RA) is a complex inflammatory disorder associated with synovitis and joint destruction that affects an estimated 1·3 million Americans and causes significant morbidity, a reduced life-span and lost work productivity. The use of biological therapies for the treatment of RA is costly, and the selection of therapies is still largely empirical and not guided by the underlying biological features of the disease in individual patients. The synovitis associated with RA is characterized by an influx of B and T cells, macrophages and neutrophils and the expansion of fibroblast-like synoviocytes, which form pannus and lead to cartilage and bone destruction. RA is associated with synovial production of rheumatoid factor (RF) and anti-citrullinated protein autoantibodies (ACPA) and with the production of inflammatory cytokines, including interleukin (IL)-1, IL-6, IL-17 and tumour necrosis factor (TNF)-α, which are targets for RA therapeutics. Recent ideas about the pathogenesis of RA emphasize a genetic predisposition to develop RA, a preclinical phase of disease that is associated with the production of ACPA and the development of symptomatic disease following inflammatory initiating events that are associated with expression of citrullinated epitopes in the joints of patients. However, we still have a limited understanding of the cytokine and intracellular pathways that regulate ACPA levels. In humans, therapy with biological agents affords a unique opportunity to better understand the cytokine and signalling pathways regulating ACPA levels and the impact of ACPA level changes on disease activity. In this study we summarize the effect of RA therapies on ACPA levels and B cell responses. PMID:23607804

  4. Release of Active Peptidyl Arginine Deiminases by Neutrophils Can Explain Production of Extracellular Citrullinated Autoantigens in Rheumatoid Arthritis Synovial Fluid

    PubMed Central

    Spengler, Julia; Lugonja, Božo; Jimmy Ytterberg, A.; Zubarev, Roman A.; Creese, Andrew J.; Pearson, Mark J.; Grant, Melissa M.; Milward, Michael; Lundberg, Karin; Buckley, Christopher D.; Filer, Andrew; Raza, Karim; Cooper, Paul R.; Chapple, Iain L.

    2015-01-01

    Objective In the majority of patients with rheumatoid arthritis (RA), antibodies specifically recognize citrullinated autoantigens that are generated by peptidylarginine deiminases (PADs). Neutrophils express high levels of PAD and accumulate in the synovial fluid (SF) of RA patients during disease flares. This study was undertaken to test the hypothesis that neutrophil cell death, induced by either NETosis (extrusion of genomic DNA–protein complexes known as neutrophil extracellular traps [NETs]) or necrosis, can contribute to production of autoantigens in the inflamed joint. Methods Extracellular DNA was quantified in the SF of patients with RA, patients with osteoarthritis (OA), and patients with psoriatic arthritis (PsA). Release of PAD from neutrophils was investigated by Western blotting, mass spectrometry, immunofluorescence staining, and PAD activity assays. PAD2 and PAD4 protein expression, as well as PAD enzymatic activity, were assessed in the SF of patients with RA and those with OA. Results Extracellular DNA was detected at significantly higher levels in RA SF than in OA SF (P < 0.001) or PsA SF (P < 0.05), and its expression levels correlated with neutrophil concentrations and PAD activity in RA SF. Necrotic neutrophils released less soluble extracellular DNA compared to NETotic cells in vitro (P < 0.05). Higher PAD activity was detected in RA SF than in OA SF (P < 0.05). The citrullinated proteins PAD2 and PAD4 were found attached to NETs and also freely diffused in the supernatant. PAD enzymatic activity was detected in supernatants of neutrophils undergoing either NETosis or necrosis. Conclusion Release of active PAD isoforms into the SF by neutrophil cell death is a plausible explanation for the generation of extracellular autoantigens in RA. PMID:26245941

  5. Effects of Supplemental Citrulline-Malate Ingestion on Blood Lactate, Cardiovascular Dynamics, and Resistance Exercise Performance in Trained Males.

    PubMed

    Wax, Benjamin; Kavazis, Andreas N; Luckett, William

    2016-01-01

    Citrulline-malate (CM) has been proposed to provide an ergogenic effect during resistance exercise; however, there is a paucity of research investigating these claims. Therefore, we investigated the impact that CM supplementation would have on repeated bouts of resistance exercise. Fourteen resistance-trained males participated in a randomized, counterbalanced, double-blind study. Subjects were randomly assigned to placebo (PL) or CM (8 g) and performed three sets each of chin-ups, reverse chin-ups, and push-ups to failure. One week later, subjects ingested the other supplement and performed the same protocol. Blood lactate (BLa), heart rate (HR), and blood pressure (BP) were measured preexercise, with BLa measured a second time immediately following the last set, while HR and BP were measured 5 and 10 min postexercise. Citrulline-malate ingestion significantly increased the amount of repetitions performed for each exercise (chin-ups: PL = 28.4 ± 7.1, CM = 32.2 ± 5.6, p = .003; reverse chin-ups: PL = 26.6 ± 5.6, CM = 32.1 ± 7.1, p = .017; push-ups: PL = 89.1 ± 37.4, CM = 97.7 ± 36.1, p < .001). Blood lactate data indicated a time effect (p < .001), but no treatment differences (p = .935). Systolic BP data did not show differences for time (p = .078) or treatment (p = .119). Diastolic BP data did not show differences for time (p = .069), but indicated treatment differences (p = .014) for subjects ingesting CM. Collectively, these findings suggests that CM increased upper-body resistance performance in trained college-age males.

  6. Analysis of L-citrulline and L-arginine in Ficus deltoidea leaf extracts by reverse phase high performance liquid chromatography

    PubMed Central

    Shafaei, Armaghan; Aisha, Abdalrahim F. A.; Siddiqui, Mohammad Jamshed Ahmad; Ismail, Zhari

    2015-01-01

    Background: Ficus deltoidea (FD) is one of the native plants widely distributed in several countries in Southeast Asia. Previous studies have shown that FD leaf possess antinociceptive, wound healing and antioxidant properties. These beneficial effects have been attributed to the presence of primary and secondary metabolites such as polyphenols, amino acids and flavonoids. Objective: The aim was to develop a reverse phase high-performance liquid chromatography method with ultraviolet detection that involves precolumn derivatisation with O-phthaladehyde for simultaneous analysis of two amino acids L-citrulline and L-arginine in FD leaf extracts. Materials and Methods: An isocratic elution program consisting of methanol: acetonitrile: Water at 45:45:10 v/v (solvent A) and 0.1 M phosphate buffer pH 7.5 (solvent B) at A: B v/v ratio of 80:20 on Zorbax Eclipse C18 SB-Aq column (250 × 4.6 mm, 5 μm) were used. The flow rate was set at 1 ml/min and detection was carried out at 338 nm with 30 min separation time. Results: Good linearity for L-citrulline and L-arginine was obtained in the range 0.1-1000 μg/ml at R2 ≥ 0.998. The limit of detection and limit of quantification values for both L-citrulline and L-arginine were 1 and 5 μg/ml, respectively. The average of recoveries was in the range 94.94-101.95%, with relative standard deviation (%RSD) less than 3%. Intra- and inter-day precision was in the range 96.36-102.43% with RSD less than 2%. Conclusion: All validation parameters of the developed method indicate the method is reliable and efficient for simultaneous determination of L-citrulline and L-arginine for routine analysis of FD. PMID:25598632

  7. Roles of export genes cgmA and lysE for the production of L-arginine and L-citrulline by Corynebacterium glutamicum.

    PubMed

    Lubitz, Dorit; Jorge, João M P; Pérez-García, Fernando; Taniguchi, Hironori; Wendisch, Volker F

    2016-10-01

    L-arginine is a semi-essential amino acid with application in cosmetic, pharmaceutical, and food industries. Metabolic engineering strategies have been applied for overproduction of L-arginine by Corynebacterium glutamicum. LysE was the only known L-arginine exporter of this bacterium. However, an L-arginine-producing strain carrying a deletion of lysE still accumulated about 10 mM L-arginine in the growth medium. Overexpression of the putative putrescine and cadaverine export permease gene cgmA was shown to compensate for the lack of lysE with regard to L-arginine export. Moreover, plasmid-borne overexpression of cgmA rescued the toxic effect caused by feeding of the dipeptide Arg-Ala to lysE-deficient C. glutamicum and argO-deficient Escherichia coli strains. Deletion of the repressor gene cgmR improved L-arginine titers by 5 %. Production of L-lysine and L-citrulline was not affected by cgmA overexpression. Taken together, CgmA may function as an export system not only for the diamine putrescine and cadaverine but also for L-arginine. The major export system for L-lysine and L-arginine LysE may also play a role in L-citrulline export since production of L-citrulline was reduced when lysE was deleted and improved by 45 % when lysE was overproduced.

  8. Highly luminescent and biocompatible, L-citrulline-capped ZnS:Mn nanocrystals for rapid screening of metal accumulating Lysinibacillus fusiformis bacteria.

    PubMed

    Sajimol, Augustine M; Roselin, Alex; Sreevalsa, V G; Deepa, G D; Bhat Sarita, G; Jayalekshmi, S

    2013-01-01

    Biocompatible and highly luminescent manganese doped zinc sulfide (ZnS:Mn) nanocrystals of average particle size 10 nm have been synthesized by capping with a novel amino acid ligand, L-citrulline. Though there are many reports on the bioimaging applications of nanostructured semiconductors, the present study focused on the detection of a special type of metal accumulating bacteria, Lysinibacillus fusiformis. This bacterium has significant applications in the disposal of metal components from industrial effluents. In this context, the detection of this bacterium is quite important and the present work demonstrates a novel technique for this bacterial detection. The synthesized nanocrystals were attached to Lysinibacillus fusiformis and characteristics of the bioconjugated system were studied. The blue shift observed in the ultraviolet-visible absorption and photoluminescence spectra of the bioconjugated system, confirms conjugation of the Lysinibacillus fusiformis with L-citrulline-capped ZnS:Mn. When the bioconjugated system (capped ZnS:Mn + bacteria) was observed using a fluorescent microscope under excitation wavelengths 365.4 nm (ultraviolet), 435.8 nm (blue) and 546.1 nm (green), fluorescence emissions were obtained in yellow, green and red regions respectively. The study of relative growth of Lysinibacillus fusiformis in the presence of L-citrulline-capped ZnS:Mn proves biocompatible property of these nanocrystals and their tunable color properties under different excitation wavelengths make them ideal for biolabeling applications.

  9. Effect of ethanol and low pH on citrulline and ornithine excretion and arc gene expression by strains of Lactobacillus brevis and Pediococcus pentosaceus.

    PubMed

    Araque, Isabel; Bordons, Albert; Reguant, Cristina

    2013-02-01

    The accumulation of citrulline and ornithine in wine or beer as a result of the arginine catabolism of some lactic acid bacteria (LAB) species increases the risk of ethyl carbamate and putrescine formation, respectively. Several LAB species, which are found as spoilage bacteria in alcoholic beverages, have been reported to be arginine degrading. This study evaluates the effect of ethanol content and low pH on the excretion of citrulline and ornithine by two strains belonging to the potential contaminant species Lactobacillus brevis and Pediococcus pentosaceus. In the conditions that most affected cell viability, arginine consumption per cell increased noticeably, indicating that arginine utilization may be a stress responsive mechanism. L. brevis showed a higher accumulation of ornithine in the media than P. pentosaceus. In the presence of ethanol, a higher expression of the arcC gene was found in P. pentosaceus, which resulted in a lower excretion of citrulline and ornithine than in L. brevis. This suggests that L. brevis is more likely to produce these amino acids, which are precursors of ethyl carbamate and putrescine.

  10. Type-III interferons and rheumatoid arthritis: Correlation between interferon lambda 1 (interleukin 29) and antimutated citrullinated vimentin antibody levels.

    PubMed

    Castillo-Martínez, Diana; Juarez, Maribel; Patlán, Mariana; Páez, Araceli; Massó, Felipe; Amezcua-Guerra, Luis M

    2017-03-01

    To assess serum type III or lambda (λ) interferons (IFN) levels and its clinical and laboratory associations in rheumatoid arthritis (RA). A cross-sectional study including 43 patients with RA (86% females; age 45.3 ± 10.3 years) and 43 healthy individuals was performed. Clinical data including disease activity, acute-phase reactants, rheumatoid factor and anticyclic citrullinated peptide (anti-CCP) antibodies were collected. Serum IFNλ1, IFNλ2, IFNλ3, CXCL8 and anti-mutated citrullinated vimentin (anti-MCV) antibody levels were measured. Patients with RA had higher IFNλ1 (113.5 ± 118.6 pg/mL versus 55.9 ± 122.3 pg/mL; p < 0.0001) and IFNλ2 (245.4 ± 327.7 pg/mL versus 5.1 ± 11.0 pg/mL; p = 0.009) levels than controls, but not IFNλ3 levels. Notably, IFNλ1 levels were found to be higher in both patients with active disease (124.9 ± 135.9 pg/mL; p < 0.001) and quiescent disease (99.0 ± 93.7 pg/mL; p < 0.01), while IFNλ2 levels were higher only in patients with active disease (264.0 ± 356.1 pg/mL; p = 0.02). A noteworthy association between serum IFNλ1 levels and anti-MCV antibody titers (Spearman's rho coefficient 0.36, 95% CI 0.36 to 0.61; p = 0.02) was observed. Serum IFNλ1 and IFNλ2 levels are abnormally elevated in patients with RA and the former are linearly associated with circulating anti-MCV antibody levels. These results may place type-III IFN as an attractive new therapeutic target in RA.

  11. Single cell cloning and recombinant monoclonal antibodies generation from RA synovial B cells reveal frequent targeting of citrullinated histones of NETs

    PubMed Central

    Corsiero, Elisa; Bombardieri, Michele; Carlotti, Emanuela; Pratesi, Federico; Robinson, William; Migliorini, Paola; Pitzalis, Costantino

    2016-01-01

    Objectives Rheumatoid arthritis (RA) is characterised by breach of self-tolerance towards citrullinated antigens with generation of anti-citrullinated peptide/proteins antibodies (ACPA). Currently, the nature and source of citrullinated antigens driving the humoral autoimmune response within synovial ectopic lymphoid structures (ELS) is a crucial unknown aspect of RA pathogenesis. Here we characterised the autoreactive B-cell response of lesional B cells isolated from ELS+RA synovium. Methods Single synovial tissue CD19+cells were Fluorescence Activated Cell Sorting (FACS)-sorted and VH/VL Ig genes cloned to generate recombinant monoclonal antibodies (rmAbs) from patients with ELS+/ACPA+RA. Results RA-rmAbs immunoreactivity analysis provided the following key findings: (1) in a chIP-based array containing 300 autoantigens and in a ‘citrullinome’ multiplex assay, a strong reactivity against citrullinated histones H2A/H2B (citH2A/H2B) was observed in ∼40% of RA-rmAbs, followed by cit-fibrinogen and cit-vimentin; (2) anti-citH2A/H2B-reactive RA-rmAbs (but not anti-citH2A/H2B negative) selectively recognised neutrophil extracellular traps (NETs) from peripheral blood and/or RA joint neutrophils; (3) anti-citH2A/citH2B and anti-NET immunobinding was dependent on affinity maturation and was completely abrogated following reversion of hypermutated IgVH/VL genes to germline sequences; (4) ELS+ (not ELS−) RA synovial tissues engrafted into Severe Combined ImmunoDeficiency (SCID) mice released human anti-citH2A/citH2B and anti-NET antibodies in association with the intra-graft expression of CXCL13 and lymphotoxin (LT)-β, two master regulators of ELS. Conclusion We provided novel evidence that B cells differentiated within synovial ELS in the RA joints frequent target deiminated proteins which could be generated during NETosis of RA synovial neutrophils including histones. Thus, NETs could represent a source of citrullinated antigens fuelling the ACPA autoimmune

  12. Single cell cloning and recombinant monoclonal antibodies generation from RA synovial B cells reveal frequent targeting of citrullinated histones of NETs.

    PubMed

    Corsiero, Elisa; Bombardieri, Michele; Carlotti, Emanuela; Pratesi, Federico; Robinson, William; Migliorini, Paola; Pitzalis, Costantino

    2016-10-01

    Rheumatoid arthritis (RA) is characterised by breach of self-tolerance towards citrullinated antigens with generation of anti-citrullinated peptide/proteins antibodies (ACPA). Currently, the nature and source of citrullinated antigens driving the humoral autoimmune response within synovial ectopic lymphoid structures (ELS) is a crucial unknown aspect of RA pathogenesis. Here we characterised the autoreactive B-cell response of lesional B cells isolated from ELS+RA synovium. Single synovial tissue CD19+cells were Fluorescence Activated Cell Sorting (FACS)-sorted and VH/VL Ig genes cloned to generate recombinant monoclonal antibodies (rmAbs) from patients with ELS+/ACPA+RA. RA-rmAbs immunoreactivity analysis provided the following key findings: (1) in a chIP-based array containing 300 autoantigens and in a 'citrullinome' multiplex assay, a strong reactivity against citrullinated histones H2A/H2B (citH2A/H2B) was observed in ∼40% of RA-rmAbs, followed by cit-fibrinogen and cit-vimentin; (2) anti-citH2A/H2B-reactive RA-rmAbs (but not anti-citH2A/H2B negative) selectively recognised neutrophil extracellular traps (NETs) from peripheral blood and/or RA joint neutrophils; (3) anti-citH2A/citH2B and anti-NET immunobinding was dependent on affinity maturation and was completely abrogated following reversion of hypermutated IgVH/VL genes to germline sequences; (4) ELS+ (not ELS-) RA synovial tissues engrafted into Severe Combined ImmunoDeficiency (SCID) mice released human anti-citH2A/citH2B and anti-NET antibodies in association with the intra-graft expression of CXCL13 and lymphotoxin (LT)-β, two master regulators of ELS. We provided novel evidence that B cells differentiated within synovial ELS in the RA joints frequent target deiminated proteins which could be generated during NETosis of RA synovial neutrophils including histones. Thus, NETs could represent a source of citrullinated antigens fuelling the ACPA autoimmune response within the RA synovium. Published by

  13. Extracellular expression of natural cytosolic arginine deiminase from Pseudomonas putida and its application in the production of L-citrulline.

    PubMed

    Su, Lingqia; Ma, Yue; Wu, Jing

    2015-11-01

    The Pseudomonas putida arginine deiminase (ADI), a natural cytosolic enzyme, and Thermobifida fusca cutinase were co-expressed in Escherichia coli, and the optimized cutinase gene was used for increasing its expression level. 90.9% of the total ADI protein was released into culture medium probably through a nonspecific leaking mechanism caused by the co-expressed cutinase. The enzymatic properties of the extracellular ADI were found to be similar to those of ADI prepared by conventional cytosolic expression. Extracellular production of ADI was further scaled up in a 3-L fermentor. When the protein expression was induced by IPTG (25.0μM) and lactose (0.1gL(-1)h(-1)) at 30°C, the extracellular ADI activity reached 101.2UmL(-1), which represented the highest ADI production ever reported. In addition, the enzymatic synthesis of l-citrulline was performed using the extracellularly expressed ADI, and the conversion rate reached 100% with high substrate concentration at 650gL(-1).

  14. Poncet's disease with high titers of rheumatoid factor and anti-citrullinated peptide antibodies mimicking rheumatoid arthritis.

    PubMed

    Sasaki, Hirokazu; Inagaki, Masako; Shioda, Mikio; Nagasaka, Kenji

    2015-01-01

    Reactive arthritis accompanying tuberculosis (TB), also known as Poncet's disease, is a rare condition. In the present report, we describe the case of a patient with Poncet's disease, who presented with high titers of rheumatoid factor (RF) and anti-citrullinated peptide antibodies (ACPA), which mimicked rheumatoid arthritis (RA). A 69-year-old man with a childhood history of chronic left gonitis suffered from right knee arthritis for 3 years. Chronic monoarthritis in his right knee and positive results obtained on interferon-gamma release assay were suggestive of tuberculous arthritis. However, there was no evidence of TB infection. Moreover, the high titers of RF and ACPA suggested a diagnosis of RA. Surprisingly, the culture of a small sample from his bony ankylosed left knee that had no focal signs of infection, exhibited a positive result for TB infection. Thus, based on these findings, the patient was diagnosed with Poncet's disease. His symptoms improved after initiation of anti-TB therapy, which supported the accuracy of the diagnosis. In addition, we analyzed the characteristics of Poncet's disease by conducting a literature review, and identified that the presence of extra-articular manifestation and negative results for RF and ACPA tests were the features that facilitated distinguishing between typical Poncet's disease and RA; however, since tuberculous patients occasionally exhibit positive results for ACPA tests, the differential diagnosis is essential in ACPA-positive arthritic patients.

  15. Significant association of periodontal disease with anti-citrullinated peptide antibody in a Japanese healthy population - The Nagahama study.

    PubMed

    Terao, Chikashi; Asai, Keita; Hashimoto, Motomu; Yamazaki, Toru; Ohmura, Koichiro; Yamaguchi, Akihiko; Takahashi, Katsu; Takei, Noriko; Ishii, Takanori; Kawaguchi, Takahisa; Tabara, Yasuharu; Takahashi, Meiko; Nakayama, Takeo; Kosugi, Shinji; Sekine, Akihiro; Fujii, Takao; Yamada, Ryo; Mimori, Tsuneyo; Matsuda, Fumihiko; Bessho, Kazuhisa

    2015-05-01

    Anti-citrullinated peptide antibody (ACPA) is a highly specific autoantibody to rheumatoid arthritis (RA). Recent studies have revealed that periodontal disease (PD) is closely associated with RA and production of ACPA in RA. Analyses of associations between PD and ACPA production in a healthy population may deepen our understandings. Here, we analyzed a total of 9554 adult healthy subjects. ACPA and IgM-rheumatoid factor (RF) was quantified and PD status was evaluated using the number of missing teeth (MT), the Community Periodontal Index (CPI) and Loss of Attachment (LA) for these subjects. PD status was analyzed for its association with the positivity and categorical levels of ACPA and RF conditioned for covariates which were shown to be associated with PD, ACPA or RF. As a result, all of MT, CPI and LA showed suggestive or significant associations with positivity (p = 0.024, 0.0042 and 0.037, respectively) and levels of ACPA (p ≤ 0.00031), but none of the PD parameters were associated with those of RF. These association patterns were also observed when we analyzed 6206 non-smokers of the participants. The significant associations between PD parameters and positivity and levels of ACPA in healthy population support the fundamental involvement of PD with ACPA production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Serum anticyclic citrullinated protein antibody titers are correlated with the response to biological agents in patients with rheumatoid arthritis

    PubMed Central

    Takahashi, Ryo; Isojima, Sakiko; Umemura, Masayu; Miura, Yoko; Oguro, Nao; Ishii, Syo; Seki, Shinya; Tokunaga, Takahiro; Tsukamoto, Hiroyuki; Furuya, Hidekazu; Yanai, Ryo; Kasama, Tsuyoshi

    2014-01-01

    Anticyclic citrullinated protein antibody (ACPA) is known as an important indicator for diagnosis of rheumatoid arthritis (RA). Our aim was to examine the relationship between the serum ACPA titer at baseline and responsiveness to biological agents (antagonists of either tumor necrosis factor or interleukin 6) in patients with RA. ACPA was measured using second-generation chemiluminescent enzyme immunoassay. Disease activity was assessed using disease activity scores 28. Fifty-seven RA patients with biological agents were enrolled, and the median ACPA titer at baseline was 110.0 U/mL. The median ACPA titer was 23.3 U/mL and 183.0 U/mL in the good and moderate response groups, respectively, which were significantly lower than in the no response group (404.0 U/mL). In addition, 69.2% and 26.9% of patients with low (<100 U/mL) and moderate (100–499 U/mL) basal ACPA titers showed a moderate to good response. Of the patients with higher (≥500 U/mL) basal ACPA titers, only 14.0% and 42.5% showed a good or moderate response, respectively. The remission rate was 77.8% in the ACPA-negative, which was significantly higher than the rate of 25% in the ACPA-positive patients. The results suggest that the ACPA titers are correlated with the efficacy of the biological agents used in patients with RA. PMID:27790035

  17. Positive association between serum thymic stromal lymphopoietin and anti-citrullinated peptide antibodies in patients with rheumatoid arthritis

    PubMed Central

    Koyama, K; Ohba, T; Haro, H; Nakao, A

    2015-01-01

    Thymic stromal lymphopoietin (TSLP) has been suggested recently to play an important role in the pathophysiology of rheumatoid arthritis (RA). However, there is little information on serum TSLP concentrations in RA and its clinical significance. The present study investigated whether serum TSLP concentrations were affected in patients with RA. Using an enzyme-linked immunosorbent assay (ELISA), we measured TSLP concentrations in the serum obtained from 100 patients with RA, 60 patients with osteoarthritis (OA) and 34 healthy volunteers. We also investigated the correlation between serum TSLP concentrations and clinical parameters of disease activity in RA [disease activity score using 28 joint counts (DAS28)-C-reactive protein (CRP), DAS28-erythrocyte sedimentation rate (ESR), Clinical Disease Activity Index (CDAI]), patient’s/-physician’s Visual Analogue Scale (VAS), swollen joints count, tender joints count, CRP, ESR and matrix metalloproteinase-3 (MMP-3) concentrations]. In addition, we investigated the correlation between serum TSLP concentrations and anti-citrullinated peptide antibody (ACPA) and serum tumour necrosis factor (TNF)-α. Serum TSLP levels in patients with RA were significantly higher than those in patients with OA and in healthy volunteers. Interestingly, serum TSLP concentrations were correlated significantly with ACPA titres, but not with other clinical parameters. There was a significant increase in serum TSLP concentrations in patients with RA, which was correlated positively with serum ACPA titres. These findings suggest that in patients with RA, TSLP may play a role in ACPA production by B cells. PMID:25817699

  18. Absence of antibody to cyclic citrullinated peptide in sera of non-arthritic patients with chronic hepatitis B virus infection.

    PubMed

    Lee, Sang-il; Yoo, Wan Hee; Yun, Hee Jin; Kim, Dal Sik; Lee, Hye Soo; Choi, Sam Im; Hur, Ji An; Cho, Yong Gon

    2007-07-01

    The objective of this study was to investigate if antibody to cyclic citrullinated peptide (anti-CCP) is detected in sera of patients with chronic hepatitis B virus (HBV) infection. Serum anti-CCP and IgA, IgG, and IgM rheumatoid factor (RF) isotypes were measured by enzyme-linked immunosorbent assay on 176 non-arthritic patients with HBV infection. IgA RF, IgG RF, and IgM RF were detectable in 29.5, 21, and 18.8% of the tested sera, respectively, with a total seropositivity rate of 42.7%. Marginally elevated anti-CCP was detected in one patient (0.6%). By regression analysis, there was no statistically significant association between the serum levels of anti-CCP and serum IgA, IgG, or IgM RF (R (2) = 0.033, with respective p values of 0.224, 0.297, and 0.334). In conclusion, anti-CCP was rarely detected in non-arthritic patients with HBV infection in contrast to RF. Thus, testing for anti-CCP may be a useful tool for the diagnosis of rheumatoid arthritis in this population.

  19. Prevalence of autoantibodies to cyclic citrullinated peptide in patients with rheumatic diseases other than rheumatoid arthritis: a French multicenter study.

    PubMed

    Fabien, Nicole; Olsson, Nils-Olivier; Goetz, Joëlle; Johanet, Catherine; Escande, Andrée; Bardin, Nathalie; Sanmarco, Marielle; Andre, Chantal; Chevailler, Alain; Humbel, René-Louis; Chretien, Pascale; Monier, Jean-claude; Fortenfant, Françoise; Oksman, Françoise; Taillefer, Marie-France; Sibilia, Jean

    2008-02-01

    Our objective was to evaluate the prevalence of autoantibodies to cyclic citrullinated peptides (anti-CCP aAbs) in a cohort of patients with a variety of inflammatory or non-inflammatory rheumatic diseases other than rheumatoid arthritis (RA). Six hundred and nine serum samples were tested for anti-CCP aAbs and for rheumatoid factor (RF) using enzyme-linked immunosorbent assays and immunonephelometry. The prevalence of anti-CCP aAbs and RF reached 10% and 25%, respectively, using the positive cutoff value suggested by the manufacturers. Using a higher cutoff value (50 U/ml) for both aAbs, the prevalence was lower with 6% and 16%, respectively. The specificity of both markers for RA thus reached 94% and 84%, respectively. Anti-CCP aAbs were found to be elevated in inflammatory and also in non-inflammatory rheumatic diseases in the same proportion. Clinical data obtained for 36 positive patients showed that 17% developed RA within 5 years. In conclusion, anti-CCP aAbs are clearly more specific than RF for RA. Follow-up of anti-CCP aAbs-positive patients with inflammatory or non-inflammatory rheumatic diseases other than RA could be important considering the predictive value of these aAbs for the development of RA.

  20. Supporting data for the MS identification of distinct transferrin glycopeptide glycoforms and citrullinated peptides associated with inflammation or autoimmunity

    PubMed Central

    Rosal-Vela, A.; Barroso, A.; Giménez, E.; García-Rodríguez, S.; Longobardo, V.; Postigo, J.; Iglesias, M.; Lario, A.; Merino, J.; Merino, R.; Zubiaur, M.; Sanz-Nebot, V.; Sancho, J.

    2016-01-01

    This data article presents the results of all the statistical analyses applied to the relative intensities of the detected 2D-DiGE protein spots for each of the 3 performed DiGE experiments. The data reveals specific subsets of protein spots with significant differences between WT and CD38-deficient mice with either Collagen-induced arthritis (CIA), or with chronic inflammation induced by CFA, or under steady-state conditions. This article also shows the MS data analyses that allowed the identification of the protein species which serve to discriminate the different experimental groups used in this study. Moreover, the article presents MS data on the citrullinated peptides linked to specific protein species that were generated in CIA+ or CFA-treated mice. Lastly, this data article provides MS data on the efficiency of the analyses of the transferrin (Tf) glycopeptide glycosylation pattern in spleen and serum from CIA+ mice and normal controls. The data supplied in this work is related to the research article entitled “identification of multiple transferrin species in spleen and serum from mice with collagen-induced arthritis which may reflect changes in transferrin glycosylation associated with disease activity: the role of CD38” [1]. All mass spectrometry data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with identifiers PRIDE: PXD002644, PRIDE: PXD002643, PRIDE: PXD003183 and PRIDE: PXD003163. PMID:26909372

  1. Branched-chain amino acids, arginine, citrulline alleviate central fatigue after 3 simulated matches in taekwondo athletes: a randomized controlled trial.

    PubMed

    Chen, I-Fan; Wu, Huey-June; Chen, Chung-Yu; Chou, Kuei-Ming; Chang, Chen-Kang

    2016-01-01

    The decline in cognitive performance has been shown after fatiguing exercise. Branched-chain amino acids (BCAA) have been suggested to alleviate exercise-induced central fatigue. Arginine and citrulline could remove the excess NH3 accumulation accompanied with BCAA supplementation by increasing nitric oxide biosynthesis and/or urea cycle. The purpose of this study is to investigate the effect of the combined supplementation of BCAA, arginine, and citrulline on central fatigue after three simulated matches in well-trained taekwondo athletes. In a double-blind randomized cross-over design, 12 male taekwondo athletes performed two trials containing three simulated matches each. Each match contained three 2-min rounds of high-intensity intermittent exercise. At the end of the second match, two different supplementations were consumed. In the AA trial, the subjects ingested 0.17 g/kg BCAA, 0.05 g/kg arginine and 0.05 g/kg citrulline, while placebo was consumed in the PL trial. A validated taekwondo-specific reaction test battery was used to measure the cognitive performance after each match. The premotor reaction time in the three single-task tests and the reaction time in the secondary task in the dual-task test were maintained in the AA trial after three matches, while they were impaired in the PL trial, resulting in significantly better performance in the AA trial. These improvements in the AA trial coincided with significantly lower plasma free tryptophan/BCAA ratio, increased NOx concentrations, and similar NH3 concentrations. This study suggested that the combined supplementation could alleviate the exercise-induced central fatigue in elite athletes.

  2. Acute citrulline-malate supplementation improves maximal strength and anaerobic power in female, masters athletes tennis players.

    PubMed

    Glenn, Jordan M; Gray, Michelle; Jensen, Austen; Stone, Matthew S; Vincenzo, Jennifer L

    2016-11-01

    Citrulline-malate (CM) is a precursor to nitric-oxide (NO) in the NO synthase (NOS) pathway and is suggested to increase exercise performance in younger individuals. With age, NO production decreases and augmented NO production may provide beneficial effects on sports performance among masters athletes (MAs). To examine the effects of acute CM supplementation on grip strength, vertical power, and anaerobic cycling performance in female, MA tennis players. Seventeen female MA (51 ± 9 years) completed two double-blind, randomized trials consuming CM (12 g dextrose + 8 g CM) and placebo (PLA) (12 g dextrose). One hour after consumption, subjects completed grip strength, vertical power, and Wingate anaerobic cycling assessments in respective order. Maximal and average grip strength, peak and average vertical power, anaerobic capacity, peak power, explosive power, and ability to sustain anaerobic power were calculated from the tests. When consuming CM, participants exhibited greater maximal (p = .042) and average (p = .045) grip strength compared to PLA. No differences existed between trials for peak (p = .51) or average (p = .51) vertical power. For the Wingate, peak power (p < .001) and explosive power (p < .001) were significantly greater when consuming CM compared to PLA. For the ability to sustain power, a significant effect (p < .001) was observed for time within trials, but no significant differences were observed between trials regarding supplement consumed. These data suggest that consuming CM before competition has the potential to improve tennis match-play performance in masters tennis athletes. However, this study utilized a controlled laboratory environment and research evaluating direct application to on-court performance is warranted.

  3. Estimation of nitric oxide synthase activity via LC-MS/MS determination of 15N3-citrulline in biological samples

    PubMed Central

    Shin, Beom Soo; Fung, Ho-Leung; Upadhyay, Mahesh; Shin, Soyoung

    2015-01-01

    Rationale We showed that the metabolite peaks of 15N3-citrulline (15N3-CIT) and 15N3-arginine (15N3-ARG) could be detected when 15N4-ARG was metabolized by nitric oxide synthase (NOS) in endothelial cells. The usefulness of these metabolites as potential surrogate indices of nitric oxide (NO) generation is evaluated. Methods A hydrophilic-interaction liquid chromatography electrospray tandem mass spectrometric assay (LC-MS/MS) was utilized for the simultaneous analysis of 15N4-ARG, ARG, CIT, 15N3-CIT and 15N3-ARG. 15N3-CIT and 15N3-ARG from impurities of 15N4-ARG were determined and corrected for the calculation of their concentration. 15N4-ARG-derived NO, i.e., 15NO formation was determined by analyzing 15N-nitrite accumulation by another LC-MS/MS assay. Results After EA.hy926 human endothelial cells were challenged with 15N4-ARG for 2 hours, the peak intensities of 15N3-CIT and 15N3-ARG significantly increased with 15N4-ARG concentration and positively correlated with 15N-nitrite production. The estimated Km values were independent of the metabolite (i.e., 15N3-CIT, 15N3-CIT+15N3-ARG or 15N-nitrite) used for calculation. However, after correction for its presence as a chemical contaminant of 15N4-ARG, 15N3-ARG was only a marginal contributor for the estimation of NOS activity. Conclusions These data suggest that the formation of 15N3-CIT can be used as an indicator of NOS activity when 15N4-ARG is used as a substrate. This approach may be superior to the radioactive 14C-CIT method which can be contaminated by 14C-urea, and to the 14N-nitrite method which lacks sensitivity. PMID:26349467

  4. Quantitative Metabolomic Analysis of Urinary Citrulline and Calcitroic Acid in Mice after Exposure to Various Types of Ionizing Radiation

    PubMed Central

    Goudarzi, Maryam; Chauthe, Siddheshwar; Strawn, Steven J.; Weber, Waylon M.; Brenner, David J.; Fornace, Albert J.

    2016-01-01

    With the safety of existing nuclear power plants being brought into question after the Fukushima disaster and the increased level of concern over terrorism-sponsored use of improvised nuclear devices, it is more crucial to develop well-defined radiation injury markers in easily accessible biofluids to help emergency-responders with injury assessment during patient triage. Here, we focused on utilizing ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to identify and quantitate the unique changes in the urinary excretion of two metabolite markers, calcitroic acid and citrulline, in mice induced by different forms of irradiation; X-ray irradiation at a low dose rate (LDR) of 3.0 mGy/min and a high dose rate (HDR) of 1.1 Gy/min, and internal exposure to Cesium-137 (137Cs) and Strontium-90 (90Sr). The multiple reaction monitoring analysis showed that, while exposure to 137Cs and 90Sr induced a statistically significant and persistent decrease, similar doses of X-ray beam at the HDR had the opposite effect, and the LDR had no effect on the urinary levels of these two metabolites. This suggests that the source of exposure and the dose rate strongly modulate the in vivo metabolomic injury responses, which may have utility in clinical biodosimetry assays for the assessment of exposure in an affected population. This study complements our previous investigations into the metabolomic profile of urine from mice internally exposed to 90Sr and 137Cs and to X-ray beam radiation. PMID:27213362

  5. Absence of antibodies to cyclic citrullinated peptide in sera of patients with hepatitis C virus infection and cryoglobulinemia.

    PubMed

    Wener, Mark H; Hutchinson, Kathleen; Morishima, Chihiro; Gretch, David R

    2004-07-01

    To determine if antibodies to cyclic citrullinated peptide (anti-CCP) are found in chronic hepatitis C virus (HCV) infection. Rheumatoid factor (RF) and anti-CCP were measured in sera from 50 patients with HCV infection but without cryoglobulinemia, sera from 29 patients with mixed cryoglobulinemia (including 13 with rheumatic symptoms and 5 with arthritis), and sera from 20 normal blood donors. Anti-CCP was measured by second-generation enzyme-linked immunosorbent assay (ELISA). No sera with elevated anti-CCP were found in patients with HCV infection without cryoglobulinemia, and in that population, the maximum anti-CCP was 10 units, well below the positive cutoff of 20 units. Positive findings on RF testing >13 IU/ml were present in 22 (44%) of the HCV patients, with RF >50 IU/ml in 8 (16%) and a maximum RF of 526 IU/ml. Of the cryoglobulinemia patients, 22 (76%) had positive results on tests for RF, including 18 (62%) with RF >50 IU/ml and a maximum RF of 5,540 IU/ml. Two (6.9%) of the cryoglobulinemia patients had borderline-positive findings on tests for anti-CCP (25 units and 37 units), which were false-positive results caused by nonspecific binding in the ELISA. No association between the RF and the anti-CCP concentrations was found. Whereas RF was frequent in patients with HCV infection with and without cryoglobulinemia, anti-CCP was not observed in patients with uncomplicated HCV infection. Borderline-positive anti-CCP results were observed infrequently in patients with mixed cryoglobulinemia and were caused by nonspecific binding to plastic. Measurement of anti-CCP may help in diagnosing RA in patients with chronic HCV infection.

  6. L-Citrulline increases hepatic sensitivity to insulin by reducing the phosphorylation of serine 1101 in insulin receptor substrate-1.

    PubMed

    Yoshitomi, Hisae; Momoo, Maki; Ma, Xiao; Huang, Yewei; Suguro, Shiori; Yamagishi, Yoshie; Gao, Ming

    2015-06-18

    Insulin resistance is characterized by deficient responses to insulin in its target tissues. In the present study, we examined the effects of L-Citrulline (L-Cit) on insulin sensitivity and signaling cascades in rat hepatoma H4IIE cells and SHRSP.Z-Leprfa/IzmDmcr rats. H4IIE cells were pretreated in the presence or absence of 250 μM L-Cit in serum-free medium and then incubated in the presence or absence of 0.1 nM insulin. Rats were allocated into 2 groups; a control group (not treated) and L-Cit group (2 g/kg/day, L-Cit) and treated for 8 weeks. L-Cit enhanced the insulin-induced phosphorylation of Akt in H4IIE cells. Moreover, the inhibited expression of Dex/cAMP-induced PEPCK mRNA by insulin was enhanced by the L-Cit treatment. The phosphorylation of tyrosine, which is upstream of Akt, in insulin receptor substrate-1 (IRS-1) was increased by the L-Cit treatment. The L-Cit-induced enhancement in insulin signaling was not related to the binding affinity of insulin to the insulin receptor or to the expression of the insulin receptor, but to a decrease in the phosphorylation of serine 1101 in IRS-1. These results were also confirmed in animal experiments. In the livers of L-Cit-treated rats, PI3K/Akt signaling was improved by decreases in the phosphorylation of serine 1101. We herein demonstrated for the first time the beneficial effects of L-Cit on improved insulin resistance associated with enhanced insulin sensitivity. These results may have clinical applications for insulin resistance and the treatment of type-2 diabetes.

  7. Acute ingestion of citrulline stimulates nitric oxide synthesis but does not increase blood flow in healthy young and older adults with heart failure

    PubMed Central

    Schutzler, Scott E.; Schrader, Amy; Spencer, Horace J.; Azhar, Gohar; Deutz, Nicolaas E. P.; Wolfe, Robert R.

    2015-01-01

    To determine if age-associated vascular dysfunction in older adults with heart failure (HF) is due to insufficient synthesis of nitric oxide (NO), we performed two separate studies: 1) a kinetic study with a stable isotope tracer method to determine in vivo kinetics of NO metabolism, and 2) a vascular function study using a plethysmography method to determine reactive hyperemic forearm blood flow (RH-FBF) in older and young adults in the fasted state and in response to citrulline ingestion. In the fasted state, NO synthesis (per kg body wt) was ∼50% lower in older vs. young adults and was related to a decreased rate of appearance of the NO precursor arginine. Citrulline ingestion (3 g) stimulated de novo arginine synthesis in both older [6.88 ± 0.83 to 35.40 ± 4.90 μmol·kg body wt−1·h−1] and to a greater extent in young adults (12.02 ± 1.01 to 66.26 ± 4.79 μmol·kg body wt−1·h−1). NO synthesis rate increased correspondingly in older (0.17 ± 0.01 to 2.12 ± 0.36 μmol·kg body wt−1·h−1) and to a greater extent in young adults (0.36 ± 0.04 to 3.57 ± 0.47 μmol·kg body wt−1·h−1). Consistent with the kinetic data, RH-FBF in the fasted state was ∼40% reduced in older vs. young adults. However, citrulline ingestion (10 g) failed to increase RH-FBF in either older or young adults. In conclusion, citrulline ingestion improved impaired NO synthesis in older HF adults but not RH-FBF, suggesting that factors other than NO synthesis play a role in the impaired RH-FBF in older HF adults, and/or it may require a longer duration of supplementation to be effective in improving RH-FBF. PMID:26442881

  8. Acute ingestion of citrulline stimulates nitric oxide synthesis but does not increase blood flow in healthy young and older adults with heart failure.

    PubMed

    Kim, Il-Young; Schutzler, Scott E; Schrader, Amy; Spencer, Horace J; Azhar, Gohar; Deutz, Nicolaas E P; Wolfe, Robert R

    2015-12-01

    To determine if age-associated vascular dysfunction in older adults with heart failure (HF) is due to insufficient synthesis of nitric oxide (NO), we performed two separate studies: 1) a kinetic study with a stable isotope tracer method to determine in vivo kinetics of NO metabolism, and 2) a vascular function study using a plethysmography method to determine reactive hyperemic forearm blood flow (RH-FBF) in older and young adults in the fasted state and in response to citrulline ingestion. In the fasted state, NO synthesis (per kg body wt) was ∼ 50% lower in older vs. young adults and was related to a decreased rate of appearance of the NO precursor arginine. Citrulline ingestion (3 g) stimulated de novo arginine synthesis in both older [6.88 ± 0.83 to 35.40 ± 4.90 μmol · kg body wt(-1) · h(-1)] and to a greater extent in young adults (12.02 ± 1.01 to 66.26 ± 4.79 μmol · kg body wt(-1) · h(-1)). NO synthesis rate increased correspondingly in older (0.17 ± 0.01 to 2.12 ± 0.36 μmol · kg body wt(-1) · h(-1)) and to a greater extent in young adults (0.36 ± 0.04 to 3.57 ± 0.47 μmol · kg body wt(-1) · h(-1)). Consistent with the kinetic data, RH-FBF in the fasted state was ∼ 40% reduced in older vs. young adults. However, citrulline ingestion (10 g) failed to increase RH-FBF in either older or young adults. In conclusion, citrulline ingestion improved impaired NO synthesis in older HF adults but not RH-FBF, suggesting that factors other than NO synthesis play a role in the impaired RH-FBF in older HF adults, and/or it may require a longer duration of supplementation to be effective in improving RH-FBF.

  9. Effects of type II collagen epitope carbamylation and citrullination in human leucocyte antigen (HLA)-DR4(+) monozygotic twins discordant for rheumatoid arthritis.

    PubMed

    De Santis, M; Ceribelli, A; Cavaciocchi, F; Generali, E; Massarotti, M; Isailovic, N; Crotti, C; Scherer, H U; Montecucco, C; Selmi, C

    2016-09-01

    The aim of this study is to investigate the effect of the native, citrullinated or carbamylated type II human collagen T cell- and B cell-epitopes on the adaptive immune response in rheumatoid arthritis (RA). Peripheral blood T and B cells obtained from a human leucocyte D4-related (antigen DR4(-) HLA-DR4)(+) woman with early RA, her healthy monozygotic twin and an unrelated HLA-DR3(+) woman with early RA were analysed for activation (CD154/CD69), apoptosis (annexin/7-aminoactinomycin), cytokine production [interferon (IFN)γ/interleukin (IL)-17/IL-4/IL-10/IL-6] and functional phenotype (CD45Ra/CCR7) after stimulation with the collagen native T cell epitope (T261-273), the K264 carbamylated T cell epitope (carT261-273), the native B cell epitope (B359-369) or the R360 citrullinated B cell epitope (citB359-369), and the combinations of these. The T cell memory compartment was activated by T cell epitopes in both discordant DR4(+) twins, but not in the DR3(+) RA. The collagen-specific activation of CD4(+) T cells was induced with both the native and carbamylated T cell epitopes only in the RA twin. Both T cell epitopes also induced IL-17 production in the RA twin, but a greater IL-4 and IL-10 response in the healthy twin. The citrullinated B cell epitope, particularly when combined with the carbamylated T cell epitope, induced B cell activation and an increased IL-6/IL-10 ratio in the RA twin compared to a greater IL-10 production in the healthy twin. Our data suggest that circulating collagen-specific T and B cells are found in HLA-DR4(+) subjects, but only RA activated cells express co-stimulatory molecules and produce proinflammatory cytokines. Carbamylation and citrullination further modulate the activation and cytokine polarization of T and B cells. © 2016 British Society for Immunology.

  10. Environmental risk factors differ between rheumatoid arthritis with and without auto-antibodies against cyclic citrullinated peptides

    PubMed Central

    Pedersen, Merete; Jacobsen, Søren; Klarlund, Mette; Pedersen, Bo V; Wiik, Allan; Wohlfahrt, Jan; Frisch, Morten

    2006-01-01

    The aim of this study was to evaluate new and previously hypothesised non-genetic risk factors for serologic subtypes of rheumatoid arthritis (RA) defined by the presence or absence of auto-antibodies to cyclic citrullinated peptides (CCP). In a national case-control study, we included 515 patients recently diagnosed with RA according to the American College of Rheumatology 1987 classification criteria and 769 gender- and age-matched population controls. Telephone interviews provided information about non-genetic exposures, and serum samples for patients were tested for anti-CCP-antibodies. Associations between exposure variables and risk of anti-CCP-positive and anti-CCP-negative RA were evaluated using logistic regression. A series of RA subtype-specific risk factors were identified. Tobacco smoking (odds ratio [OR] = 1.65; 95% confidence interval: 1.03–2.64, for >20 versus 0 pack-years) was selectively associated with risk of anti-CCP-positive RA, whereas alcohol consumption exhibited an inverse dose-response association with this RA subtype (OR = 1.98, 1.22–3.19, for 0 versus >0–5 drinks per week). Furthermore, coffee consumption (OR = 2.18; 1.07–4.42, for >10 versus 0 cups per day), ever use of oral contraceptives (OR = 1.65; 1.06–2.57) and having a first-degree relative with schizophrenia (OR = 4.18; 1.54–11.3) appeared more strongly associated with risk of anti-CCP-positive RA. Obesity was selectively associated with risk of anti-CCP-negative RA, with obese individuals being at more than 3-fold increased risk of this subtype compared with normal-weight individuals (OR = 3.45; 1.73–6.87). Age at menarche was the only examined factor that was significantly associated with both serologic subtypes of RA (p-trends = 0.01); women with menarche at age ≥ 15 years had about twice the risk of either RA subtype compared with women with menarche at age ≤ 12 years. Major differences in risk factor profiles suggest distinct etiologies for anti

  11. Antibodies to Mutated Citrullinated Vimentin in Rheumatoid Arthritis: Diagnostic Value, Association with Radiological Damage and Axial Skeleton Affection

    PubMed Central

    Mansour, Howaida E.; Metwaly, Khaled M.; Hassan, Iman A.; Elshamy, Hebat-Allah A.; Elbeblawy, Moataz M.S.

    2010-01-01

    Background: Early definitive diagnosis and effective treatment are mandatory in rheumatoid arthritis (RA) as it can halt the disease progression and subsequent joints destruction. Objective: To investigate the diagnostic and prognostic value of anti-mutated citrullinated vimentin (anti-MCV) and its correlation with disease activity, peripheral and axial skeleton affection in RA patients. Patients and methods: A total of 123 patients with different rheumatic diseases were enrolled in a prospective-two year study at Ain Shams University hospital: 64 patients with RA and 59 patients with other rheumatic diseases as controls. RA patients were fulfilling the traditional and the new ACR/EULAR diagnostic criteria for RA. They have been followed up for two years. At baseline, all RA patients were subjected to: Clinical assessment of disease activity by taking full histories, general and local examination, measurement of 28 joint count of tender and swollen joints with calculation of disease activity score (DAS-28) for each patient. Complete blood count, erythrocytes sedimentation rate, C-reactive protein and rheumatoid factor titers were performed. Anti-MCV IgG immunoglobulins’ assay was performed at the study endpoint by ELISA. RA patients were then classified into; anti-MCV positive and anti-MCV negative groups for statistical comparison. Plain X-ray was performed on the peripheral joints and scored by the Simple Erosion Narrowing score (SEN-score). Magnetic Resonance Imaging (MRI) scans were carried out to 22 RA patients on cervical and lumbosacral regions. Results: Anti-MCV antibodies were found to be of high sensitivity (79.6%) and specificity (96.6%) in diagnosing RA. The area under the curve was 0.893 at 95% confidence interval (CI), confers an odds ratio of 23.5. Anti-MCV positive RA patients had significantly higher DAS-28 and SEN-scores than anti-MCV negative patients; who were found to have more benign disease with lower incidence of erosions (P < 0.05). MRI

  12. Benefit of early treatment in inflammatory polyarthritis patients with anti–cyclic citrullinated peptide antibodies versus those without antibodies

    PubMed Central

    Farragher, Tracey M; Lunt, Mark; Plant, Darren; Bunn, Diane K; Barton, Anne; Symmons, Deborah P M

    2010-01-01

    Objective To compare the clinical utility of anti–cyclic citrullinated peptide (anti-CCP) antibodies and rheumatoid factor (RF) testing in predicting both functional outcome and response to treatment in early inflammatory polyarthritis (IP) patients. Methods A total of 916 IP subjects from a primary care incidence registry (1990–1994) had anti-CCP antibody and RF status determined at baseline. Mean change in Health Assessment Questionnaire (HAQ) score between baseline and 5 years was compared by antibody status. The effect of treatment with disease-modifying antirheumatic drugs and/or steroids over 5 years, early (<6 months of symptom onset) versus late initiation, and duration of treatment were also compared by anti-CCP antibody status. The analysis was adjusted for treatment decisions and censoring over the followup, using marginal structural models. Results Anti-CCP antibody–positive patients (n = 268) had more severe disease both at presentation and 5 years of followup, and this was independent of RF. On adjustment, anti-CCP antibody–negative patients treated early experienced a significant improvement in functional disability compared with anti-CCP antibody–negative patients who were never treated (−0.31; 95% confidence interval [95% CI] −0.53, −0.08), and experienced additional benefit for each additional month of early treatment. Anti-CCP antibody–positive patients treated early did not have a significant improvement in HAQ score compared with those not treated (−0.14; 95% CI −0.52, 0.24). Conclusion In this first observational study to examine the influence of anti-CCP antibody status on treatment response, anti-CCP antibody–positive IP patients showed less benefit from treatment, particularly early treatment, than anti-CCP antibody–negative patients. This provides support for the inclusion of anti-CCP antibodies as well as RF in the classification criteria for rheumatoid arthritis and for stratification by anti-CCP antibody status

  13. Smoking, Porphyromonas gingivalis and the immune response to citrullinated autoantigens before the clinical onset of rheumatoid arthritis in a Southern European nested case-control study.

    PubMed

    Fisher, Benjamin A; Cartwright, Alison J; Quirke, Anne-Marie; de Pablo, Paola; Romaguera, Dora; Panico, Salvatore; Mattiello, Amalia; Gavrila, Diana; Navarro, Carmen; Sacerdote, Carlotta; Vineis, Paolo; Tumino, Rosario; Lappin, David F; Apatzidou, Danae; Apazidou, Danae; Culshaw, Shauna; Potempa, Jan; Michaud, Dominique S; Riboli, Elio; Venables, Patrick J

    2015-11-04

    Antibodies to citrullinated proteins (ACPA) occur years before RA diagnosis. Porphyromonas gingivalis expresses its own peptidylarginine deiminase (PPAD), and is a proposed aetiological factor for the ACPA response. Smoking is a risk factor for both ACPA-positive RA and periodontitis. We aimed to study the relation of these factors to the risk of RA in a prospective cohort. We performed a nested case-control study by identifying pre-RA cases in four populations from the European Prospective Investigation into Cancer and nutrition, matched with three controls. Data on smoking and other covariates were obtained from baseline questionnaires. Antibodies to CCP2 and citrullinated peptides