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To identify the targets recognized by anti-carbamylated protein antibodies (anti-CarP) in patients with early Rheumatoid Arthritis (RA), to study the cross-reactivity between anti-CarP and anti-citrullinated protein antibodies (ACPA) and to evaluate their prognostic value. 331 patients (184 RA and 147 other rheumatisms) from the Very Early Arthritis (VErA) French cohort were analyzed. We performed mass spectrometry analysis of RA sera displaying anti-CarP activity and epitope mapping of the carbamylated fibrinogen γ chain to identify immunodominant peptides. The specificity of these targets was studied using competition assays with the major antigens recognized by ACPA. The prognostic value of anti-carbamylated fibrinogen IgG antibodies (ACa-Fib IgG) was compared to that of anti-cyclic citrullinated peptide antibodies (anti-CCP) and anti-CarP using an in-house ELISA. Besides the α chain, the γ chain of fibrinogen, particularly one immunodominant epitope that has a specific reactivity, was identified as a circulating carbamylated target in sera. The prevalence of ACa-Fib was 37% at baseline and 10.9% for anti-CCP-negative RA. In anti-CCP-negative patients, ACa-Fib positivity was associated with a more inflammatory and erosive disease at baseline but not with rapid radiological progression, which remains strongly related to anti-CCP antibodies. Fibrinogen seems to be one of the antigens recognized in vivo by the anti-CarP response, particularly 2 epitopes of the γ chain, one of which is not cross reactive with ACPA. This specificity might be associated with a distinct clinical phenotype since ACa-Fib IgG were shown to be linked to systemic inflammation in very early RA but not to rapid radiological progression., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Brevet, Lattard, Guillou, Rottenberg, Fardellone, Le-Loët, Lequerré, Cosette, Boyer, Fréret and Vittecoq.)

Objectives: To refine the prevalence, characteristics and response to treatment of myositis in primary SS (pSS)., Methods: The multicentre prospective Assessment of Systemic Signs and Evolution in Sjögren's Syndrome (ASSESS) cohort of 395 pSS patients with ≥60 months' follow-up was screened by the 2017 EULAR/ACR criteria for myositis. Extra-muscular complications, disease activity and patient-reported scores were analysed., Results: Before enrolment and during the 5-year follow-up, myositis was suspected in 38 pSS patients and confirmed in 4 [1.0% (95% CI: 0.40, 2.6)]. Patients with suspected but not confirmed myositis had higher patient-reported scores and more frequent articular and peripheral nervous involvement than others. By contrast, disease duration in patients with confirmed myositis was 3-fold longer than without myositis. Two of the four myositis patients fulfilled criteria for sporadic IBM. Despite receiving three or more lines of treatment, they showed no muscle improvement, which further supported the sporadic IBM diagnosis. The two other patients did not feature characteristics of a myositis subtype, which suggested 'pure' pSS myositis. Steroids plus MTX was then efficient in achieving remission., Conclusions: Myositis, frequently suspected, occurs in 1% of pSS patients. Especially when there is resistance to treatment, sporadic IBM should be considered and might be regarded as a late complication of this disease., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: To assess the prevalence of anti-carbamylated protein (anti-CarP) antibodies in a French cohort of patients with early arthritis and to investigate their association with clinical features, final diagnosis, prognosis, and comorbidities., Methods: The presence of anti-CarP antibodies among patients with early arthritis in the French Etude et Suivi des Polyarthrites Indifférenciées Récentes (ESPOIR) cohort (n = 720) was determined using enzyme-linked immunosorbent assay. We investigated the prevalence of anti-CarP antibodies in different patient subgroups stratified according to anti-citrullinated protein antibody (ACPA) and/or rheumatoid factor (RF) status. Diagnostic and prognostic values of the test were evaluated in this population., Results: Anti-CarP antibodies were present in approximately one-third of the patients (32.6%) and in 23.6% of the patients who were seronegative for both RF and ACPA. Anti-CarP positivity was associated with a more active disease status at baseline and over time. Anti-CarP-positive patients had a significantly higher Disease Activity Score in 28 joints using the erythrocyte sedimentation rate at month 36 than anti-CarP-negative patients (3.1 ± 0.11 versus 2.8 ± 0.06; P = 0.03). Anti-CarP-positive early arthritis was associated with a higher risk of developing erosions after 96 months of follow-up (55.6% of anti-CarP-positive patients versus 37.3% of anti-CarP-negative patients) (odds ratio 2.1 [95% CI 1.2-3.6]; P = 0.009). This association was particularly true when anti-CarP was associated with ACPA positivity. Moreover, ACPA positivity alone in early arthritis was not associated with a higher risk of erosive evolution., Conclusion: Our findings indicate that anti-CarP antibodies are present in one-third of patients with early arthritis and in one-fourth of the RF-negative and ACPA-negative patients. They are particularly associated with a more severe radiographic outcome. Anti-CarP antibody positivity may help to accurately identify those at risk of erosive evolution in an early arthritis population., (© 2017, American College of Rheumatology.)

Objectives: The aim of this study was to investigate the clinical value of sVE and anti-vascular endothelial-cadherin antibodies (AAVE) in RA treated with etanercept or adalimumab combined with methotrexate., Methods: This was an 18-month prospective multicenter study in which patients had active RA, requiring TNF antagonist. sVE rates and AAVE titers were measured respectively by dot blot and ELISA. The relationship of these biomarkers with parameters reflecting articular or systemic disease activity, progression of structural damage, and response or remission to treatment was analyzed., Results: Forty-eight patients received TNF blocking agents. Variation of sVE rates were significantly correlated with that of C-reactive protein (CRP) levels at weeks 6, 12, 26 and 52. A significant decrease in sVE levels was observed in the group of patients exhibiting a decrease in CRP levels as compared to the patient group with unmodified CRP. AAVE at baseline were correlated with rheumatoid factor. Kinetics analysis of sVE levels and AAVE titers showed that their level were not associated with disease activity score and to methotrexate/adalimumab or etanercept response., Conclusions: sVE is a biomarker associated with systemic RA activity under anti-TNF. AAVE are related to autoantibodies usually associated to RA., (Copyright © 2016 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.)

Objective: To evaluate the contribution of the SPP1 rs11439060 and rs9138 polymorphisms, previously reported as autoimmune risk variants, in the rheumatoid arthritis (RA) genetic background according to anti-citrullinated protein antibodies (ACPAs) status of RA individuals., Methods: We analysed a total of 11,715 RA cases and 26,493 controls from nine independent cohorts; all individuals were genotyped or had imputed genotypes for SPP1 rs11439060 and rs9138. The effect of the SPP1 rs11439060 and rs9138 risk-allele combination on osteopontin (OPN) expression in macrophages and OPN serum levels was investigated., Results: We provide evidence for a distinct contribution of SPP1 to RA susceptibility according to ACPA status: the combination of ≥3 SPP1 rs11439060 and rs9138 common alleles was associated mainly with ACPA negativity (p=1.29×10(-5), ORACPA-negative 1.257 (1.135 to 1.394)) and less with ACPA positivity (p=0.0148, ORACPA-positive 1.072 (1.014 to 1.134)). The ORs between these subgroups (ie, ACPA-positive and ACPA-negative) significantly differed (p=7.33×10(-3)). Expression quantitative trait locus analysis revealed an association of the SPP1 risk-allele combination with decreased SPP1 expression in peripheral macrophages from 599 individuals. To corroborate these findings, we found an association of the SPP1 risk-allele combination and low serum level of secreted OPN (p=0.0157), as well as serum level of secreted OPN correlated positively with ACPA production (p=0.005; r=0.483)., Conclusions: We demonstrate a significant contribution of the combination of SPP1 rs11439060 and rs9138 frequent alleles to risk of RA, the magnitude of the association being greater in patients negative for ACPAs., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background: The aims of the present study were to determine both clinical manifestations and outcome of anti-PL7 patients with antisynthetase syndrome (ASS)., Methods: The medical records of 15 consecutive anti-PL7 patients with biopsy proven ASS were retrospectively analyzed without prior selection., Results: Anti-PL7 patients exhibited polymyositis (n=14) and dermatomyositis (n=1); extra-pulmonary manifestations of ASS included: Raynaud's phenomenon (40%), mechanic's hands (33.3%), joint impairment (26.7%), pericardial effusion (20%) and esophageal/gastrointestinal involvement (20%). The outcome of myositis was as follows: remission/improvement (91.7%) and deterioration (8.3%). Fourteen patients (93.3%) experienced interstitial lung disease (ILD). ILD preceded ASS diagnosis (n=5), was identified concomitantly with ASS (n=8) and occurred after ASS diagnosis (n=1). Patients could be divided into 3 groups according to their presenting lung manifestations: acute onset of lung disease (n=1), progressive onset of lung signs (n=11) and asymptomatic patients exhibiting abnormalities consistent with ILD on PFT and HRCT-scan (n=2). No patient had resolution of ILD, whereas 64.3% and 35.7% experienced improvement and deterioration of ILD, respectively. ILD resulted in respiratory insufficiency requiring O2 therapy in 14.3% of cases. Two patients died. Predictive parameters of ILD deterioration were: DLCO<45% at ILD diagnosis and HRCT-scan pattern of usual interstitial pneumonia (UIP)., Conclusion: Our series mainly underscores that ILD is frequent in anti-PL7 patients, leading to high morbidity. Our study further suggests that patients with predictive factors of ILD deterioration may require more aggressive therapy, especially the group of patients with DLCO<45% at ILD diagnosis and UIP pattern on HRCT-scan., (Copyright © 2013 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.)

Objectives: The aim of the present study was to assess the outcome in anti-PL12 patients with antisynthetase syndrome (ASS)., Methods: The medical records of anti-PL12 (n=5) patients with ASS were retrospectively analyzed without prior selection. To exclude false-positive patients, we included patients who were successively tested positive for anti-PL12 antibody at least twice by immunodot and/or Western blot., Results: Anti-PL12 patients experienced: myositis (n=2), Raynaud's phenomenon (n=2), mechanic's hands (n=1), joint impairment (n=4), digestive involvement (n=2), and interstitial lung disease (ILD) (n=4). The two patients with myositis exhibited deterioration of muscle manifestations despite therapy. As regards outcome of ILD, patients developed resolution (n=1), stabilization (n=1) or deterioration (n=2) of pulmonary status. One patient died of pyogenic pneumonia., Conclusion: Our series underscores that the presence of anti-PL12 antibody is associated with a particular phenotype of ASS characterized by: (1) less frequent although severe/steroid refractory myositis; (2) less common mechanic's hands and calcinosis cutis; (3) both frequent and severe ILD. Taken together, our findings suggest that PM/DM patients should routinely undergo the search for anti-PL12 antibody as this autoantibody appears to impact patients' prognosis. Furthermore, ILD patients with anti-PL12 antibody should routinely undergo clinical screening for underlying ASS., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Objectives: To test the performances of combining anti-CCP second generation (CCP2) with ACR 1987 classification criteria and to diagnose early RA in a community-based very early arthritis (VErA) patient cohort., Methods: The VErA cohort comprised 310 patients (median age 52 years; 68.1% women; median symptom duration 4.2 months; glucocorticoid- and DMARD naïve) conservatively treated during the first 2 years. At 6 years of follow-up, a three-expert committee classified the patients into three groups: RA, other classified arthritis (OCA) or unclassified arthritis (UA). We calculated the performances of the different sets, including anti-CCP2 positivity, while retaining or deleting RF and rheumatoid nodule components with ACR 1987 criteria for early RA diagnosis. Models were subjected to receiver operating characteristics curve and logistic regression analyses to try to identify relevant sets able to classify very early RA., Results: At 6 years, 149 patients were diagnosed as RA and 119 as non-RA (95 OCA and 24 UA). The original ACR 1987 criteria had 77.9% sensitivity and 64.7% specificity for the RA diagnosis at 6 years. The modified set excluding rheumatoid nodules, including anti-CCP2 positivity and retaining RF performed significantly better than ACR 1987 criteria, with 79.9% sensitivity and 64.7% specificity and with a larger area under the curve. However, in the zone of interest, i.e., ≥4/7 criteria, the curves for these sets were superimposed., Conclusions: Adding anti-CCP2 positivity and deleting rheumatoid nodules failed to improve the performances of ACR 1987 classification criteria for the diagnosis of early RA.

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, alpha-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, alpha-enolase, PGK1, calreticulin, HSP60 and the FUSE-BPs. We compared the reactivity of RA sera with citrullinated and noncitrullinated alpha-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 early untreated RA autoantibody response. For some of them, and notably the FUSE-BPs, citrullination is involved in the immunological tolerance breakdown observed earlier in RA patients. Autoantibodies recognizing a citrullinated peptide from FUSE-BP may enhance the sensibility for RA of the currently available anti-CCP2 test.

Objective: The objective of this study was to analyze the effects of 3 anti-TNFalpha agents on markers of autoimmunity in rheumatoid arthritis (RA) and spondylarthropathy (SPA) patients., Methods: First-time anti-TNFalpha biologics (infliximab, etanercept, or adalimumab) were prescribed to 156 RA and 95 SPA (58 ankylosing spondylarthritides, 37 psoriatic arthritides). During 1-2 years of follow-up, clinical, biological [antinuclear (ANA) and anti-double-stranded (dsDNA) antibodies, rheumatoid factors (RF), and anti-cyclic citrullinated peptide (CCP) for RA], and therapeutic data were collected biannually., Results: ANA appeared or ANA and anti-dsDNA titers increased significantly (P < 0.001) more under infliximab than etanercept in both rheumatisms and than adalimumab in RA patients. During the 2-year follow-up, ANA appeared more in RA patients taking adalimumab than etanercept (P = 0.003), but independently of the anti-TNFalpha used; anti-dsDNA titers rarely became positive. Under etanercept or infliximab, ANA and anti-dsDNA were not influenced by the underlying pathology nor were they affected by infliximab intensification over 18 months. Only one case of cutaneous lupus was observed in a patient having IgG anti-dsDNA. The therapeutic responses were independent of ANA and anti-dsDNA titers for all rheumatisms and biologics. In RA patients, RF titers, but not anti-CCP levels, declined with the therapeutic response for all biologics., Conclusion: This is the first study that has evaluated the impact of three TNFalpha blockers on ANA and anti-dsDNA antibodies in RA and SPA patients. Autoimmunity was more induced with infliximab than etanercept and to a lesser degree to adalimumab but, more importantly, this emergent autoimmunity was exceptionally associated to clinical manifestations of lupus.

Objectives: The objective of this study were (1) to evaluate the prevalence of anti-annexin II antibodies in patients with various autoimmune diseases and antiphospholipid syndrome and (2) to correlate anti-annexin II antibodies with anti-phospholipid antibodies., Materials and Methods: Anti-annexin II antibodies and anti-phospholipid were detected, using an enzyme-linked immunosorbent assay, in the serum of patients with primary antiphospholipid syndrome (n = 16), systemic lupus erythematosus (n = 53), primary Sjögren syndrome (n = 71), systemic sclerosis (n = 17), systemic vasculitis (n = 18), and rheumatoid arthritis (n = 119). Healthy blood donors (n = 99) were used as controls., Results: Anti-annexin II antibodies were significantly more prevalent in patients with connective tissue diseases (8.5%), especially antiphospholipid syndrome (14.8%) and rheumatoid arthritis (10%), than in controls (2%). An inverse correlation was observed between anti-annexin II antibodies and antiphospholipid antibodies., Conclusion: Annexin II can be recognized by antibodies in serum from patients with systemic autoimmune disorders. Further studies are required to determine the clinical significance of anti-annexin II antibodies in rheumatoid arthritis and to determine their diagnostic value in discriminating clinical subgroups of patients with antiphospholipid syndrome.

The aim of our study was (i) to compare the clinical and biological characteristics of 148 (137 women, 11 men) primary Sjögren's syndrome (pSS) patients at diagnosis as a function of their sex and (ii) to assess the prognostic value of anti-calpastatin and anti-alpha-fodrin autoantibodies. In addition, the presence of anti-nuclear antibodies (ANA), anti-52- and 60-kDa Sjögren's syndrome A (SSA), anti-Sjögren's syndrome B (SSB), anti-cyclic citrullinated peptide (CCP) antibodies and rheumatoid factors (RF) of IgA, IgG and IgM isotypes was sought in sera collected at pSS onset. Raynaud's syndrome, significantly more frequent in women, was the only systemic manifestation of pSS whose frequency differed significantly as a function of the patient's sex (P = 0.02). ANA (P = 0.001) and anti-60-kDa SSA autoantibodies (P = 0.03) were significantly more common in women, while men never synthesized detectable levels of anti-SSB, anti-calpastatin or IgG anti-alpha-fodrin autoantibodies. In addition, anti-CCP autoantibodies were found in low percentages of pSS patients (4% F/18% M). The absence of autoantibodies does not exclude the diagnosis of pSS in men that will be based mainly on the anatomopathological findings of a minor salivary gland biopsy. Positivity of anti-60-kDa SSA, anti-SSB, anti-calpastatin, IgA and IgG anti-alpha-fodrin antibodies is not associated with pSS clinical and biological severity.

Autoimmune response is diverse. This diversity is thought not to take place at the beginning of the autoimmune process but to occur as the disease evolves. It is mainly the consequence of the so-called epitope-spreading phenomenon and of the cross-reactivity of antibodies. Analysing autoantibody repertoire constitutes a powerful means to understand physiopathological processes at work in various diseases, mainly autoimmune diseases. In particular this analysis opens the way to precisely identify autoantigens and their changes in various pathological situations, and allows providing new biological markers in chronic inflammatory diseases. New methodologies have recently emerged for the analysis of the autoantibody repertoire in a given individual. They propose diagnostic approaches no more related upon few markers but founded upon analysis of global changes of the antibody repertoire. They belong to methodologies called target-oriented proteomics. Their common feature is to isolate autoantigens by means of affinity chromatography based upon antibody/antigen reactions. Autoantibodies to be studied interact with a protein substratum susceptible to include autoantibody targets. These interactions take place on solid macro- or microsurfaces, i.e. membrane filters or chips. Several strategies can be used for locating the specific autoantibody/autoantigen complexes and for identifying behind autoantigens. In this paper three approaches, namely, the recombinant protein chips, the SELDI techniques and the 2-D gel electrophoresis linked to mass spectrometry are described and compared.

The objective of this study was to determine the diagnostic and prognostic values of antiglucose-6-phosphate isomerase (GPI) antibodies in patients with very early arthritis. Anti-GPI antibodies were measured by ELISA using purified GPI from rabbit muscle in: (i) 383 sera from healthy blood donors (n = 120), well-established rheumatoid arthritis (RA) (n = 99) and non-RA differentiated arthritis (NRADA) (n = 164) patients; (ii) 195 sera obtained from community-recruited patients with very early inflammatory arthritis (VErA cohort) that were studied for 1 year and classified as having RA (n = 116), NRADA (n = 41), and undifferentiated arthritis (UA) (n = 38) after the follow-up period. The criterion for severity was the progression of radiographic damage. Prevalence of anti-GPI antibodies was significantly higher in well-established RA patients (45.4%) compared to healthy subjects (2.5%). Anti-GPI antibodies were also present in sera from NRADA: systemic lupus erythematosus 53%, polymyositis 45.4%, adult-onset Still's disease 44%, systemic sclerosis 42.8%, spondylarthropathies 25% and primary Sjögren's syndrome 5.8%. No significant association was found between the presence of anti-GPI antibodies and the 3 diagnostic groups from the VErA cohort. No correlation was observed between anti-GPI and autoantibodies usually associated with RA. Anti-GPI antibodies were not predictive of radiological progression in patients with very early arthritis. Thus, anti-GPI antibodies are not useful for discriminating RA from non-RA rheumatic diseases and do not constitute a predictive factor of structural damage.

The objective of the study was to determine the diagnostic value for rheumatoid arthritis (RA) of anti-filaggrin autoantibodies (autoAb) recognizing citrullinated recombinant rat filaggrin (ACRF) in community cases of very early arthritis. To evaluate the diagnostic value of ACRF, were studied sera from patients with different classified rheumatic diseases and healthy subjects (group 1, n= 422) and 314 community cases of very early arthritis (group 2) that were classified as RA (n = 176), non-RA (n = 63) and undifferentiated (n = 75) arthritides after 1 years of follow-up. ACRF were measured using a new ELISA, with results expressed as the difference between the OD value obtained on citrullinated minus that on noncitrullinated rat filaggrin (differential ACRF; dACRF). For both groups, rheumatoid factors (RF), anti-keratin autoAb (AKA) and anti-perinuclear factor (APF) were tested; for group 2, anti-CCP autoAb were also tested. Different reactivity patterns against citrullinated and noncitrullinated filaggrin were observed. Almost all sera reacting with citrullinated but not noncitrullinated filaggrin were from RA patients. Among RA and non-RA sera that recognized both forms of filaggrin, a positive result was obtained only with RA sera. For groups 1 and 2, dACRF sensitivity was 58.4% and 30.7%, and specificity for RA was 99.5% and 98.4%, respectively. In group 2, dACRF specificity for RA was better than that of RF (92.1%), APF (95.2%), AKA (96.8%) and anti-CCP (95.2%). dACRF positive predictive value was high (98.2) and close to that given by the concomitant positivity of RF and anti-CCP autoAb. Despite a high positive correlation between AKA, APF, anti-CCP and dACRF test results, they were complementary since some sera were positive for only one test. Thus, in a community setting, anti-citrullinated rat filaggrin reactivity detected by a new ELISA, whose originality is based on the difference between serum's reactivities on the citrullinated and native forms of filaggrin, had a higher diagnostic value for RA than other autoAb.

The objective of this study was to determine in systemic lupus erythematosus (SLE) the prevalence and clinical significance of anticalpastatin antibodies (ACAST), an autoantibody population previously detected in sera from patients with various connective tissue diseases. Eighty-four patients with SLE (mean age: 30 years at diagnosis, females 77) that fulfilled ACR criteria were included in the study retrospectively. Several clinical and biological data were collected. ACAST were detected by a solid-phase enzyme linked immunosorbent assay (ELISA) using as antigen a synthetic peptide corresponding to the 27 C-terminal amino acids of calpastatin (CAST-C27). The prevalence of ACAST-C27 was 13% (11/84) in SLE patients. No correlation was found between the presence of ACAST-C27 and clinical manifestations such as thrombosis and vasculitis. Furthermore, no correlation was observed with the presence ofantiphospholipid antibodies (APL). However, we found a statistically significant association between the presence of ACAST-C27 and that of secondary Sjögren syndrome (P = 0.01). The conclusion is ACAST-C27 are not associated with thrombosis in SLE patients. The association observed between ACAST-C27 and secondary Sjögren syndrome suggests that ACAST-C27 might be useful in discriminating a clinical subgroup of SLE patients.

To identify new autoantibody populations in patients with rheumatic diseases, a cDNA expression library was immunoscreened with a rheumatoid arthritis (RA) patient's serum which contains autoantibodies binding to uncharacterized polypeptides by Western-blotting. One clone encoding the amino-terminal region (Nt) [domain L and half of domain I] of human calpastatin was selected. Different fragments of the selected cDNA were prepared and the corresponding recombinant polypeptides were produced by in vitro translation and analysed by Western blotting. Most RA sera bound to recombinant amino-terminal region and domain I but not to domain L. This prompted us to use a recombinant polypeptide corresponding to the domain I of calpastatin as the antigen in a solid-phase ELISA to test sera from patients with various systemic rheumatic diseases and healthy controls.Anti-calpastatin domain I antibodies (ACAST-DI Ab), were detected by ELISA in RA, systemic lupus erythematosus (SLE), Sjögren's syndrome and control sera at respective frequencies of 10, 9, 0 and 1%. These Ab did not have prognostic value in early RA; high levels were significantly associated with vasculitis in SLE. Antibodies reacting with the calpastatin amino-terminal region are produced during systemic rheumatic diseases and are predominantly directed against domain I. High levels of these Ab may constitute a marker of vasculitis in SLE.

Objective: To identify a new autoantigen/autoantibody population in rheumatoid arthritis (RA) sera., Methods: Following a population-based recruitment effort, 255 patients with very early arthritis (median disease duration 4 months) were studied using different clinical, biologic, and radiologic assessments. After a followup period of 1 year, patients were classified as having RA (n = 145), non-RA rheumatic diseases (n = 70), and undifferentiated arthritis (n = 40). Patients' sera were analyzed by one-dimensional (1D) and 2D Western blotting. The recognized 50-kd protein was analyzed by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry (MS). RA serum reactivities were evaluated against the recombinant protein synthesized by an in vitro coupled transcription-translation system., Results: On 1D Western blots, 36 of the 145 RA sera bound to a 50-kd polypeptide. On 2D Western blots, anti-50-kd+ RA sera recognized a triplet of isoelectric point 6.5-7.0 and a molecular mass of 50 kd. The 3 spots of the triplet were analyzed by MALDI-TOF MS and were shown to correspond to human alpha-enolase. A goat anti-enolase antiserum, which recognized a band comigrating with the 50-kd antigen on 1D Western blots, gave a labeling pattern on 2D Western blots similar to that observed with anti-50-kd+ RA sera. Among the 36 RA sera that identified alpha-enolase in protein maps, only 8 recognized the recombinant (unmodified) alpha-enolase. The specificity of anti-alpha -enolase antibodies for RA was 97.1%. Half of the anti-alpha -enolase-positive RA patients were negative for both rheumatoid factor and antifilaggrin antibodies. The presence of anti-alpha-enolase antibodies was the greatest predictive factor of radiologic progression in the first 66 RA patients included., Conclusion: Autoantibodies to alpha-enolase, an enzyme of the glycolytic pathway, are present in the sera of patients with very early RA and have potential diagnostic and prognostic value for RA.

The vascular endothelium is a common target of inflammatory joint disease. Autoimmune diseases including rheumatoid arthritis, systemic lupus erythematosus, and Sjögren's syndrome can be responsible for a spectrum of vascular disorders that encompasses vasculitis, thrombosis and/or atheroma associated with the antiphospholipid syndrome, and vascular damage caused by cryoglobulin deposition. These mechanisms can coexist, particularly in lupus patients. Joint disease is sometimes the presenting manifestation in primary vasculitis. Autoantibodies are detectable in most patients with vascular involvement and inflammatory joint disease. They are not merely markers for vascular involvement: in vitro and in vivo data suggest that some autoantibodies may contribute to the genesis of endothelial lesions, together with other factors. For instance, evidence of pathogenic effects has been found for antineutrophil cytoplasmic antibody (ANCA), most notably with antimyeloperoxidase or antiproteinase-3 specificity, in small-vessel vasculitides (Wegener's granulomatosis, Churg-Strauss syndrome, and microscopic polyangiitis); for immune complexes, particularly those containing cryoglobulins, in vasculitides secondary to CTDs; and for circulating anticoagulant and anticardiolipin antibodies, above all anti-beta2-glycoprotein I, in antiphospholipid syndrome. Antibodies to annexin V, modified lipoproteins, and endothelial cells may be of interest; their clinical relevance is unclear, however, and no standardized assays are available, so thatthese antibodies are not looked for in everyday practice. When deciding which antibody tests should be performed in a given patient, the circumstances surrounding the onset of the vasculopathy should be borne in mind. In patients with previous CTD, the tests are selected based on the diagnosis. In contrast, in a patient with no previous diagnosis, a vasculopathy can be either primary or secondary to undiagnosed CTD or to antiphospholipid syndrome: consequently, a broader array of tests is needed in this situation.

Background: Calpastatin is the natural inhibitor of calpains, a protease that is overexpressed in rheumatoid synovial tissue and plays a key role in cartilage destruction. Autoantibodies to calpastatin (ACAST) were recently detected in rheumatoid arthritis (RA). Our aim was to determine their prevalence and their clinical significance., Methods: ACAST were detected in a solid-phase enzyme-linked immunosorbent assay (ELISA) using a synthetic peptide corresponding to the 27 C-terminal amino acids of calpastatin (CAST-C27) as the antigen. All sera reacting with this peptide also bound to purified erythrocyte calpastatin in an ELISA and/or an immunoblot assay. The frequencies and clinical significance of ACAST-C27 were assessed in sera from a well-documented population of 102 community-recruited patients (76 females; mean age 50 yr) with RA that had been evolving for <5 yr (median 2 yr) (group 1), 109 healthy blood donors, 289 patients with non-RA rheumatic disease and 88 community cases of very early (median 4 months) arthritis, i.e. 58 RA and 30 non-RA patients (group 2)., Results: The sensitivity of ACAST-C27 for RA was 19.5% (20/102) in group 1 and 10.3% (6/58) in group 2. These antibodies were also found in patients with anti-double-stranded DNA-positive systemic lupus erythematosus (SLE) (15.5%) and patients with anti-Ro-positive Sjögren's syndrome (18.5%). However, they were not detected in cases of rheumatism resembling early RA, i.e. peripheral spondylarthropathies. ACAST-C27 were not detected in the 30 non-RA patients of group 2. They were predominantly of immunoglobulin isotype G3 and exclusively expressed lambda chains. Among ACAST-C27-positive sera, eight out of 20 (group 1) and four out of six (group 2) were negative for rheumatoid factor and anti-keratin antibodies/antiperinuclear factor. No relationship was found between ACAST-C27 and clinical, biological or radiological findings., Conclusion: ACAST-C27 are detected only in a restricted set of connective tissue diseases and therefore appear to be specific for RA when antibodies that are usually associated with SLE or primary Sjögren's syndrome are negative. Because of their presence in community cases of very early RA, particularly in some seronegative forms, ACAST-C27 may be useful in discriminating recent-onset RA from the more common non-RA rheumatic diseases, such as spondylarthropathies.

Two IgM, kappa anti-myeloperoxidase (MPO) monoclonal antibodies, 6D6 and 9B5, bound to MPO in a solid-phase enzyme-linked immunosorbent assay were derived from the splenocytes of (NZB x NZW) F1 and MRL/lpr-lpr mice, respectively. 6D6 gave a characteristic perinuclear immunofluorescence staining pattern on ethanol-fixed human neutrophils, bound to the native form of MPO by immunoblotting and had a high constant affinity for MPO as demonstrated by real-time specific interaction. 9B5 produced a cytoplasmic immunofluorescence staining pattern, reacted with the heavy chain of MPO and had a low constant affinity for MPO. The heavy-and light-chain variable region genes of monoclonal antibodies (mAb) 6D6 and 9B5 were sequenced and found to be highly homologous to germline genes and to contain negatively charged amino acids in the complementarity determining regions. IgM MPO-binding activity was observed in most BW and MRL/lpr-lpr mouse sera, which may correspond to polyclonal activation of B cells, whereas IgG anti-MPO antibodies could be rarely detected. Thus, this study indicates that (i) BW and MRL/lpr-lpr mice do not delete IgM anti-MPO secreting B cells, do not maintain these B cells in a state of anergy, but most individuals are not able to spontaneously induce the class-switching of this autoantibody population; (ii) IgM anti-MPO antibodies can recognize different epitopes on MPO and produce different immunofluorescence staining pattern on ethanol-fixed human neutrophils, as demonstrated by the immunochemical properties of the two lupus-mouse derived mAb.

Objective To define parameters predictive of lymphoma development in patients with primary Sjögren's syndrome (SS). Methods A multicenter case-control survey was performed to identify predictors of lymphoma. Cases were patients who developed lymphoma after diagnosis of primary SS and were mainly recruited through the Club Rhumatismes et Inflammation network. For each case, 2 controls (matched for disease duration and age) were randomly selected among patients with primary SS and without lymphoma. Cases and controls were compared using univariate analysis and then using multivariate analysis to identify independent predictors of lymphoma. Results One hundred one patients with primary SS and lymphoma were included. Eighty-seven patients were women (86.1%), and the mean ± SD age at lymphoma diagnosis was 57.4 ± 12.6 years. The most frequent histologic type was B cell non-Hodgkin's lymphoma (NHL) in 99 of 101 patients, with marginal-zone lymphoma in 76 of the 99 patients (76.8%) including 58 (58.6%) with lymphoma of the mucosa-associated lymphoid tissue type. Lymphomas were most frequently located in the salivary glands (43 patients). A specific treatment was initiated at diagnosis in 87 patients with B cell NHL, and 61 patients (61.6%) achieved complete sustained remission after the first line of treatment. In the multivariate analysis, salivary gland enlargement, the presence of rheumatoid factor (RF), low C4, cryoglobulinemia, lymphopenia, and disease activity according to the European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (excluding the lymphoma domain) were found to be predictors of lymphoma. No previous treatment for primary SS was associated with any effect on lymphoma occurrence. Conclusion In addition to previously known factors predictive of lymphoma occurrence, the independent roles of RF and disease activity were demonstrated in this case-control study of primary SS-associated lymphoma. Our findings highlight the roles of chronic antigenic stimulation and disease activity in the development of this severe complication. [ABSTRACT FROM AUTHOR]