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A majority of circulating IgG is produced by plasma cells residing in the bone marrow (BM). Long-lived BM plasma cells constitute our humoral immune memory and are essential for infection-specific immunity. They may also provide a reservoir of potentially pathogenic autoantibodies, including rheumatoid arthritis (RA)-associated anti-citrullinated protein autoantibodies (ACPA). Here we investigated paired human BM plasma cell and peripheral blood (PB) B-cell repertoires in seropositive RA, four ACPA+ RA patients and one ACPA- using two different single-cell approaches, flow cytometry sorting, and transcriptomics, followed by recombinant antibody generation. Immunoglobulin (Ig) analysis of >900 paired heavy-light chains from BM plasma cells identified by either surface CD138 expression or transcriptome profiles (including gene expression of MZB1, JCHAIN and XBP1) demonstrated differences in IgG/A repertoires and N-linked glycosylation between patients. For three patients, we identified clonotypes shared between BM plasma cells and PB memory B cells. Notably, four individuals displayed plasma cells with identical heavy chains but different light chains, which may indicate receptor revision or clonal convergence. ACPA-producing BM plasma cells were identified in two ACPA+ patients. Three of 44 recombinantly expressed monoclonal antibodies from ACPA+ RA BM plasma cells were CCP2+, specifically binding to citrullinated peptides. Out of these, two clones reacted with citrullinated histone-4 and activated neutrophils. In conclusion, single-cell investigation of B-cell repertoires in RA bone marrow provided new understanding of human plasma cells clonal relationships and demonstrated pathogenically relevant disease-associated autoantibody expression in long-lived plasma cells., Competing Interests: Declaration of competing interest Linda Mathsson-Alm is employed by Thermo Fisher Scientific. The other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Competing Interests: SS, ZZ, CD and WS are employees of EUROIMMUN, a manufacturer of diagnostic reagents.

Background: There is a need for biomarker to identify patients "at risk" for rheumatoid arthritis (risk-RA) and to better predict the therapeutic response and in this study we tested the hypothesis that novel native and citrullinated heterogeneous nuclear ribonucleoprotein (hnRNP)-DL autoantibodies could be possible biomarkers., Methods: Using protein macroarray and ELISA, epitope recognition against hnRNP-DL was analysed in sera from different developed RA disease and diagnosed SLE patients. Toll-like receptor (TLR) 7/9 and myeloid differentiation primary response gene 88 (MyD88)-dependency were studied in sera from murine disease models. HnRNP-DL expression in cultivated cells and synovial tissue was analysed by indirect immunofluorescence, immunoblot and immunohistochemistry., Results: HnRNP-DL was highly expressed in stress granules, citrullinated in the rheumatoid joint and targeted by autoantibodies either as native or citrullinated proteins in patient subsets with different developed RA disease. Structural citrullination dependent epitopes (SCEs) of hnRNP-DL were detected in 58% of the SLE patients although 98% of these sera were α-CCP-2-negative. To obtain a specific citrullinated signal value, we subtracted the native antibody value from the citrullinated signal. The citrullinated/native index of autoantibodies against hnRNP-DL (CN DL -Index) was identified as a new value for an "individual window of treatment success" in early RA and for the detection of RF IgM/α-CCP-2 seronegative RA patients (24-46%). Negative CN DL -index was found in SLE patients, risk-RA and early RA cohorts such as EIRA where the majority of these patients are DAS28-responders to methotrexate (MTX) treatment (87%). High positive CN DL -values were associated with more severe RA, shared epitope and parenchymal changes in the lung. Specifically, native α-hnRNP-DL is TLR7/9-dependent, associated with pain and ROC analysis revealed an association to initial MTX or etanercept treatment response, especially in seronegative RA patients., Conclusion: CN DL -index defines people at risk to develop RA and the "window of treatment success" thereby closing the sensitivity gap in RA., (© 2021. The Author(s).)

Objective: To analyse the association between anti-carbamylated protein antibodies (Anti-CarP) and interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients., Methods: Cross-sectional study including RA patients fulfilling the 2010 ACR/EULAR criteria. The main population comprised two groups: (1) RA patients diagnosed with RA-ILD (RA-ILD group); (2) RA patients without ILD (non-ILD RA group). Non-ILD RA patients in whom ILD was suspected underwent a diagnostic work-up and, if ILD was diagnosed, were switched to the RA-ILD group. ILD was diagnosed by high-resolution computed tomography and confirmed by a multidisciplinary committee. An independent replication sample was also obtained. Three Anti-CarP IgG autoantibodies against fetal calf serum (Anti-FCS), fibrinogen (Anti-Fib) and chimeric fibrine/filagrine homocitrullinated peptide (Anti-CFFHP) and one Anti-CarP IgA against FCS (Anti-FCS-IgA) were determined by home-made ELISA. Associations between Anti-CarP and ILD were analysed using multivariable logistic regression adjusted by smoking, sex, age, RA disease duration, rheumatoid factor and anticitrullinated protein antibodies., Results: We enrolled 179 patients: 37 (21%) were finally diagnosed with RA-ILD. Anti-CarP specificities were more frequent in RA-ILD patients (Anti-FCS 70% vs 43%; Anti-Fib 73% vs 51%; Anti-CFFHP 38% vs 19%; Anti-CarP-IgA 51% vs 20%, p<0.05 for all comparisons). Serum titers of Anti-CarP were significantly higher in RA-ILD patients. Anti-CarP specificities showed a robust effect towards increasing the odds of ILD in the multivariate analysis (Anti-FCS (OR: 3.42; 95% CI: 1.13 to 10.40), Anti-Fib (OR: 2.85; 95% CI: 0.83 to 9.70), Anti-CFFHP (OR: 3.11; 95% CI: 1.06 to 9.14) and Anti-FCS-IgA (OR: 4.30; 95% CI: 1.41 to 13.04)). Similar findings were observed in the replication sample., Conclusions: Anti-CarP were strongly associated with ILD. The role of homocitrullination in RA-ILD merits further investigation., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Rheumatoid arthritis (RA) is associated with a significant disease burden and high costs for society. Because the disease has identifiable preclinical stages, screening and prevention have become a possibility in RA. Anticitrullinated peptide antibodies (ACPAs) are arguably the most likely candidate biomarker to screen for RA. This paper reviews the evidence for the use of ACPAs as a screening test in the broader general population, to identify individuals at high risk of subsequent onset of RA. We will review the diagnostic properties of the test and its positive and negative predictive value in different settings. We will discuss how ACPA testing could effectively be integrated in a broader screening strategy for RA., Competing Interests: Competing interests: The author’s institution has a scientific collaboration with Inova and Thermofisher, 2 producers of ACPA tests. The research collaboration is scientific and does not involve any monetary compensation or other kind of benefits., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial membrane damage and autoantibody production. RA is a heterogeneous disease, where cytokines such as IL-15, IL-21, and IFN-γ have been associated. However, their association with the autoantibodies has not been clearly described. The aim of this study was to evaluate the relationship between the cytokines IL-15, IL-21, and IFN-γ with the autoantibodies (RF, anti-CCP, anti-MCV, and anti-PADI4) in RA and disease activity., Methodology: This study included 153 RA patients and 80 control subjects (CS). The levels of IL-15, IL-21, IFN-γ, anti-CCP, anti-MCV, and anti-PADI4 were quantified by ELISA, whereas RF was quantified by turbidimetry. The disease activity was evaluated by the indices disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR), clinical disease activity index (CDAI), and simple disease activity index (SDAI)., Results: The serum levels of IL-15, IL-21, and IFN-γ, and autoantibodies were increased in RA patients, compared with CS (p < 0.05). A correlation was found between IL-21 and anti-CCP and anti-MCV (p < 0.05). According to RA evolution, RF, anti-CCP, and anti-MCV had higher levels in early RA. In addition, increased levels of IL-21 were observed in RA seropositive patients (RF/anti-CCP/anti-MCV). The higher levels of both cytokines and autoantibodies were observed in moderate activity, evaluated by the three indices., Conclusions: Our results suggest that the increased soluble levels of IL-15, IL-21, and IFN-γ are involved in the inflammatory network in RA. However, IL-21 serum levels are associated with higher titers of autoantibodies (RF, anti-CCP, and anti-MCV) and IL-15 with moderate activity. Key Points • IL-15, IL-21, and IFN-y are associated with the immunopathology of RA, but not significantly with the evolution of the disease. • RF, anti-CCP, and anti-MCV had higher levels in early than established RA. • IL-21 has an association with RF, anti-CCP, and anti-MCVand, for this reason, could be proposed as a disease biomarker. • Patients with activity moderate of disease showed higher levels of RF, anti-CCP, anti-MCV, and IL-15.

Objects: Although the association of cigarette smoking (CS) with susceptibility to rheumatoid arthritis (RA) has been established, the impact of CS on anticitrullinated cyclic peptide/protein antibody (ACPA) and rheumatoid factor (RF) levels in RA has yet been clear, especially in relation to shared epitope (SE) alleles., Methods: A total of 6239 subjects, the largest Asian study ever, from two independent Japanese cohorts were enrolled. Precise smoking histories, levels of ACPA and RF, and HLA-DRB1 allele status were withdrawn from databases. Associations between CS and high ACPA or RF levels, defined by the top quartiles, were evaluated. The effect of HLA-DRB1 alleles on the association was further investigated., Results: CS at RA onset conferred the risks of high levels of both antibodies, especially RF (OR 2.06, p=7.4×10 -14 ; ACPA, OR 1.29, p=0.012), suggesting that RF level is more sensitive to CS than ACPA level. The patients who had quitted CS before RA onset showed a trend of decreased risks of developing high levels of ACPA or RF, and the risks steadily decreased according to the cessation years. The association of CS with high ACPA level was observed only in subjects carrying SE alleles, while the association of high RF level was observed regardless of SE., Conclusions: CS confers the risks of high autoantibody levels in RA in different manners; CS interacts with SE alleles on ACPA level, while CS impacts on RF level despite SE allele. These data suggest novel distinct production mechanisms of RF and ACPA., Competing Interests: Competing interests: KI received speaker fee from fifteen pharmaceutical companies (Asahi-Kasei Pharma, Astellas Pharma, Abbvie GK Inc., AYUMI, Eisai, Otsuka, Kaken, Takeda, Mitsubishi-Tanabe, Chugai, Eli-Lilly, Bristol-Myers Squibb, Pfizer Japan Inc., Janssen and UCB Japan). MH, HI and MT belong to a department that has been financially supported by four pharmaceutical companies (Mitsubishi-Tanabe, Chugai, AYUMI and UCB Japan). TM received personal fees from fourteen pharmaceutical companies (Pfizer Japan Inc., Mitsubishi-Tanabe, Eisai, Astellas, AYUMI, Chugai, Daiichi Sankyo, Nippon Shinyaku, Takeda Pharmaceutical, Eli-Lilly, Asahi-Kasei Pharma, Sanofi, Bristol-Myers Squibb and GlaxoSmithKline). KURAMA cohort study is supported by grant from Daiichi Sankyo Co. Ltd. This study is conducted as investigator initiate study. These companies had no role in the design of the study, the collection or analysis of the data, the writing of the manuscript or decision to submit the manuscript for the publication. IORRA cohort study is supported by grant by twenty pharmaceutical companies (Daiichi Sankyo Co. Ltd., Mitsubishi-Tanabe, Chugai, Bristol-Myers Squibb, AYUMI, Astellas, Pfizer Japan Inc., Takeda Pharmaceutical, Eisai, Nippon Shinyaku, YL Biologics Ltd., AbbVie, Novartis Pharmaceutical K.K., Kaken Pharmaceutical Co., Ltd., UCB Japan, Ono Pharmaceutical Co., Ltd., Taisho Toyama Pharmaceutical Co., Ltd., Teijin Pharma, Torii Pharmaceutical Co., Ltd. and Nippon Boehringer Ingelheim Co., Ltd.). These sponsors were not involved in the: study design; collection, analysis and interpretation of data; writing of the paper; and/or decision to submit for publication., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Rheumatoid arthritis is a clinical autoimmune syndrome that causes joint damage. The positive or negative anti-cyclic citrullinated protein (CCP) antibodies serodiagnosis differentiates two subsets of the disease, each with different genetic background. Previous studies have identified associations between KIR genes and rheumatoid arthritis but not with anti-CCP serodiagnosis. Therefore, we investigated the proportion of patients seropositive and seronegative to anti-CCP and its possible association with KIR (killer cell immunoglobulin-like receptor) genes. We included 100 patients with rheumatoid arthritis from western Mexico, who were determined for anti-CCP serodiagnosis by ELISA, and 16 KIR genes were genotyped by PCR-SSP. The proportion of seropositive anti-CCP patients was 83%, and they presented a higher frequency of KIR2DL2 genes than the seronegative group (73.6% vs. 46.2%, p = 0.044) which, in turn, presented a higher KIR2DL2-/KIR2DL3+ genotype frequency than the first ones (46.2% vs. 17.2%, p = 0.043). These results suggest different KIR genetic backgrounds for each subset of the disease according to anti-CCP serodiagnosis.

Objectives: Mast cells (MCs) are involved in the pathogenesis of rheumatoid arthritis (RA). However, their contribution remains controversial. To establish their role in RA, we analysed their presence in the synovium of treatment-naïve patients with early RA and their association and functional relationship with histological features of synovitis., Methods: Synovial tissue was obtained by ultrasound-guided biopsy from treatment-naïve patients with early RA (n=99). Immune cells (CD3/CD20/CD138/CD68) and their relationship with CD117 + MCs in synovial tissue were analysed by immunohistochemistry (IHC) and immunofluorescence (IF). The functional involvement of MCs in ectopic lymphoid structures (ELS) was investigated in vitro , by coculturing MCs with naïve B cells and anticitrullinated protein antibodies (ACPA)-producing B cell clones, and in vivo in interleukin-27 receptor alpha (IL27 ra )-deficient and control mice during antigen-induced arthritis (AIA)., Results: High synovial MC counts are associated with local and systemic inflammation, autoantibody positivity and high disease activity. IHC/IF showed that MCs reside at the outer border of lymphoid aggregates. Furthermore, human MCs promote the activation and differentiation of naïve B cells and induce the production of ACPA, mainly via contact-dependent interactions. In AIA, synovial MC numbers increase in IL27 ra deficient mice, in association with ELS and worse disease activity., Conclusions: Synovial MCs identify early RA patients with a severe clinical form of synovitis characterised by the presence of ELS., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2018. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: We studied the relationship between serum lipids and autoantibodies and inflammatory markers in rheumatoid arthritis (RA) patients to explore the effect of serum lipids on the diagnosis and judgment of disease activity in RA patients., Methods: Serum lipids including TCHO, TG, HDLC and LDLC and anti-CCP, RF, CRP, ESR of RA patients from May 2013 to August 2017 were retrospectively analyzed in the First Affiliated Hospital of Fujian Medical University., Results: With the dilution factor increased, the concentrations of serum lipids and anti-CCP, CRP and RF showed the same downward trend, indicating that the detection methods of the above indicators were reasonable and would not be affected by hyperlipidemia. CRP and ESR levels were negatively correlated with HDLC concentration in male and female RA patients. However, the concentration of anti-CCP and RF were closely related to TG. In all the RA patients and female RA patients, the RF level was negatively correlated with the TG concentration. Moreover, with the TG concentration increased, the proportion of patients with high concentrations of anti-CCP levels decreased. In addition, in male RA patients, anti-CCP and ESR concentration increased with the increase of LDLC., Conclusion: The concentrations of HDLC, TG and LDLC were associated with the concentration of anti-CCP, RF, CRP and ESR in RA patients. Therefore, clinical diagnosis of RA and determination of disease activity should consider the impact of the concentration of serum lipids in order to make a reasonable judgment on the diagnosis of the disease., (Copyright © 2018. Published by Elsevier B.V.)

Objective: Although anticitrullinated protein antibody (ACPA)-positive and ACPA-negative rheumatoid arthritis (RA) have different aetiopathology, the clinical presentation at the time of diagnosis is similar. This study evaluated whether there are phenotypic differences in the symptomatic pre-RA phase., Methods: Patients with arthralgia included in the Leiden clinically suspect arthralgia cohort who developed arthritis during follow-up were studied (n=67). Symptoms at symptom onset, symptoms and signs at presentation with arthralgia and time to arthritis development were compared between ACPA-positive and ACPA-negative patients., Results: In ACPA-negative patients (n=37), the location of initial symptoms less often included the lower extremities (22% vs 50%, p=0.014). At presentation with arthralgia, ACPA-positive patients had a longer symptom duration (median 22 vs 14 weeks, p=0.005), less tender joints (mean 5 vs 9, p=0.007) and less difficulty making a fist (11% vs 43%, p=0.004). However, after presentation with arthralgia, ACPA-positive patients developed arthritis more quickly (median 6 vs 18 weeks, p=0.015). A partial least squares regression analysis showed clustering of ACPA-positive and ACPA-negative patients based on the above-mentioned clinical variables., Conclusion: This study is the first showing that ACPA-positive and ACPA-negative patients have clinical differences in the symptomatic phase preceding clinical arthritis. This contributes to the notion that ACPA-positive and ACPA-negative RA develop differently., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

The aim of this study was to investigate association of protein tyrosine phosphatase non-receptor type 22 (PTPN22) rs2476601 and signal transducer and activator of transcription 4 (STAT4) rs7574865 polymorphisms with rheumatoid arthritis (RA) susceptibility and to assess potential association with the status of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibodies, serum neopterin, and disease activity. RF, anti-CCP antibodies, and neopterin were assayed in serum of 100 unrelated RA patients and 114 controls. STAT4 rs7574865 G/T and PTPN22 rs2476601 C/T polymorphisms were genotyped by the TaqMan allelic discrimination method. The frequency of STAT4 variant allele was significantly higher in RA patients than in controls (p = 0.01), while the variant allele of PTPN22 was identified in only two RA patients, in a heterozygous form and in none of control subjects. The frequency of STAT4 variant allele carrier genotypes (GT+TT) was significantly higher among RA patients than in controls (43.7 vs. 10.5%, p = 0.02) and associated with RA under additive and dominant models. The frequency of RF and anti-CCP positivity was significantly higher among RA patients carrying T allele genotypes compared to patients carrying wild genotype (P = 0.02 and 0.04, respectively). No significant associations between STAT4 variant and serum neopterin or disease activity parameters were identified. Our study confirmed the association of STAT4 rs7574865 polymorphism with RA and was the first to indicate an association with RF and anti-CCP antibodies positivity. We also found PTPN22 rs2476601 has no role in susceptibility to RA in Egyptian patients.

Introduction: The presence of anti-CCP is an important prognostic tool of rheumatoid arthritis (RA). But research is still ongoing on its relationship with disease activity and functional capacity., Objectives: To study the relationship between anti-CCP and disease activity, functional capacity and structural damage indexes, by means of conventional radiography (CR) and magnetic resonance imaging (MRI), in cases of established RA., Methods: Cross-sectional study with RA patients with 1-10 disease duration. Participants underwent clinical evaluation with anti-CCP. Disease activity was assessed using the Clinical Disease Activity Index (CDAI), and functional capacity through the Health Assessment Questionnaire (HAQ). CR analysis was carried out by the Sharp van der Heijde index (SvdH), and MRI analysis by RAMRIS (Rheumatoid Arthritis Magnetic Resonance Image Scoring)., Results: We evaluated 56 patients, with a median (IqR) age of 55 (47.5-60) years; 50 (89.3%) participants were female and 37 (66.1%) were positive for anti-CCP. Medians (IqR) of CDAI, HAQ, SvdH and RAMRIS were 14.75 (5.42-24.97) 1.06 (0.28-1.75), 2 (0-8) and 15 (7-35), respectively. There was no association between anti-CCP and CDAI, HAQ and SvdH and RAMRIS scores., Conclusion: Our results have not established an association of anti-CCP with the severity of disease. To date, we cannot corroborate anti-CCP as a prognostic tool in patients with established RA., (Copyright © 2015 Elsevier Editora Ltda. All rights reserved.)

Background: Articular manifestations are common in systemic lupus erythematosus (SLE) whereas erosive disease is not. Antibodies to cyclic citrullinated peptide (anti-CCP) are citrulline-dependent in rheumatoid arthritis (RA), whereas the opposite is suggested in SLE, as reactivity with cyclic arginine peptide (CAP) is typically present. Antibodies targeting carbamylated proteins (anti-CarP) may occur in anti-CCP/rheumatoid factor (RF)-negative cases long before clinical onset of RA. We analysed these antibody specificities in sera from European patients with SLE in relation to phenotypes, smoking habits and imaging data., Methods: Cases of SLE (n = 441) from Linköping, Sweden, and Leiden, the Netherlands, were classified according to American College of Rheumatology (ACR) and/or Systemic Lupus Erythematosus International Collaborating Clinics (SLICC) criteria. IgG anti-CCP, anti-CAP and anti-CarP were analysed by immunoassays. Radiographic data from 102 Swedish patients were available., Results: There were 16 Linköping (6.8%) and 11 Leiden patients (5.4%) who were anti-CCP-positive, of whom approximately one third were citrulline-dependent: 40/441 (9.1%) were anti-CarP-positive, and 33% of the anti-CarP-positive patients were identified as anti-CCP-positive. No associations were found comparing anti-CCP or anti-CarP with ACR-defined phenotypes, immunologic abnormalities or smoking habits. Radiographically confirmed erosions were found in 10 patients, and were significantly associated with anti-CCP, anti-CarP and RF. Musculoskeletal ultrasonography scores were higher in anti-CCP-positive compared to anti-CCP-negative patients., Conclusions: In the hitherto largest anti-CarP study in SLE, we demonstrate that anti-CarP is more prevalent than anti-CCP and that the overlap is limited. We obtained some evidence that both autoantibodies seem to be associated with erosivity. Similar pathogenetic mechanisms to those seen in RA may be relevant in a subgroup of SLE cases with a phenotype dominated by arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory disease leading to joint destruction. Serologically, it can be differentiated according to rheumatoid factor (RF), anti-cyclic citrullinated peptide antibodies (anti-CCP), or both. This differentiation is prognostically and therapeutically relevant. No method has been described to separate the two forms phenotypically. We hypothesize that a differentiation is possible by evaluating oscillation patterns in power Doppler sonography (PDS). In a prospective study, 20 patients with anti-CCP-positive RA and 20 patients with anti-CCP-negative RA with active wrist synovitis were examined. A PDS scan was performed, and perfusion maxima (P max ) and minima (P min ) as well as the amplitude (ΔP) were determined by a blinded study member. The amplitude was standardized (sΔP) by dividing by P max , and the anti-CCP-positive and anti-CCP-negative patients as well as the RF-positive and RF-negative were compared to each other. In the ultrasonographic evaluation, we found a highly significant difference in sΔP between CCPp and CCPn patients (median 19.0 vs. 42.9 %, p < 0.0001). sΔP is independent of disease activity. The absolute amplitude ΔP did not differ between the groups. Also, in anti-CCP-positive patients there was a completely linear correlation between P max and P min , and this was far less marked in anti-CCP-negative patients. Anti-CCP-positive and anti-CCP-negative RA display different PDS oscillation patterns. This constitutes a nonserological parameter to differentiate between the two forms. The difference in PDS oscillation patterns suggests that the underlying pathological process differs between the forms.

We assessed the clinical feasibility of conducting immunoassays based on surface-enhanced Raman scattering (SERS) in the early diagnosis of rheumatoid arthritis (RA). An autoantibody against citrullinated peptide (anti-CCP) was used as a biomarker, magnetic beads conjugated with CCP were used as substrates, and the SERS nanotags were comprised of anti-human IgG-conjugated hollow gold nanospheres (HGNs). We were able to determine the anti-CCP serum levels successfully by observing the distinctive Raman intensities corresponding to the SERS nanotags. At high concentrations of anti-CCP (>25 U/mL), the results obtained from the SERS assay confirmed those obtained via an ELISA-based assay. Nevertheless, quantitation via our SERS-based assay is significantly more accurate at low concentrations (<25 U/mL). In this study, we compared the results of an anti-CCP assay of 74 clinical blood samples obtained from the SERS-based assay to that of a commercial ELISA kit. The results of the anti-CCP-positive group (n = 31, >25 U/mL) revealed a good correlation between the ELISA and SERS-based assays. However, in the anti-CCP-negative group (n = 43, <25 U/mL), the SERS-based assay was shown to be more reproducible. Accordingly, we suggest that SERS-based assays are novel and potentially useful tools in the early diagnosis of RA.

Background: Rheumatoid arthritis (RA) is a common autoimmune disease with a complex genetic background. The gene encoding protein tyrosine phosphatase non-receptor type 22 (PTPN22) has been reported to be associated with RA in several populations., Objectives: This work aimed at assessing the association of PTPN22 +1858 C>T gene polymorphism with the susceptibility, activity and severity of RA in Egyptian subjects., Subjects and Methods: This study included 112 unrelated RA patients who were compared to 122 healthy unrelated individuals taken from the same locality. For all subjects, DNA was genotyped for PTPN22 +1858 C>T (rs2476601) polymorphism using the PCR-RFLP technique. Antibodies to cyclic citrullinated peptides (anti-CCP) were measured by enzyme-linked immunosorbent assay (ELISA)., Results: Cases showed significantly higher PTPN22 +1858 T allele carriage rate (CT+TT genotypes) compared to controls (34.8% vs. 8.2%, OR=5.98, 95% CI=2.81-12.73, p<0.001). Also the frequency of the PTPN22 +1858 T allele was significantly higher among cases compared to controls (18.7% vs. 4.5%, OR=4.89; 95% CI=2.45-9.76, p<0.001). Cases positive to the PTPN22 T allele (CT+TT genotypes) showed no significant difference from those with the CC genotype regarding clinical and immune parameters. Nonetheless, they showed a more functional disability presented in their significantly higher health assessment questionnaire (HAQ) score (p=0.04)., Conclusions: This study is a confirmatory evidence of the association of the PTPN22 +1858 T allele with susceptibility and functional disability of RA in Egyptian subjects., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: Early appearance of antibodies specific for native human type II collagen (anti-CII) characterizes an early inflammatory and destructive phenotype in adults with rheumatoid arthritis (RA). The objective of this study was to investigate the occurrence of anti-CII, IgM RF, IgA RF and anti-CCP in serum samples obtained early after diagnosis, and to relate the occurrence of autoantibodies to outcome after eight years of disease in children with juvenile idiopathic arthritis (JIA)., Methods: The Nordic JIA database prospectively included JIA patients followed for eight years with data on remission and joint damage. From this database, serum samples collected from 192 patients, at a median of four months after disease onset, were analysed for IgG anti-CII, IgM RF, IgA RF and IgG anti-CCP. Joint damage was assessed based on Juvenile Arthritis Damage Index for Articular damage (JADI-A), a validated clinical instrument for joint damage., Results: Elevated serum levels of anti-CII occurred in 3.1%, IgM RF in 3.6%, IgA RF in 3.1% and anti-CCP in 2.6% of the patients. Occurrence of RF and anti-CCP did to some extent overlap, but rarely with anti-CII. The polyarticular and oligoarticular extended categories were overrepresented in patients with two or more autoantibodies. Anti-CII occurred in younger children, usually without overlap with the other autoantibodies and was associated with high levels of C-reactive protein (CRP) early in the disease course. All four autoantibodies were significantly associated with joint damage, but not with active disease at the eight-year follow up., Conclusions: Anti-CII, anti-CCP, IgA RF and IgM RF detected early in the disease course predicted joint damage when assessed after eight years of disease. The role of anti-CII in JIA should be further studied.

Protein citrullination and degradation by matrix metalloproteinases (MMP) plays a central role in the pathology of rheumatoid arthritis (RA). Autoantibodies are known to target citrullinated vimentin. The aim of this study was to investigate the relationship between the blood levels of MMP-degraded and citrullinated vimentin (VICM), as compared with the levels of MMP-degraded and non-citrullinated vimentin (VIM), and the standard anti-CCP biomarker in RA patients undergoing treatment. Thus, VIM, VICM and anti-CCP were quantified by ELISA in serum samples from baseline and week 8 of patients (n = 257) with RA, treated with either tocilizumab (8 mg/kg), methotrexate (7.5–15 mg/kg) or a placebo and compared with a reference cohort (n = 64). The three biomarkers were elevated in RA serum compared with the reference cohort: medians were 1.7 vs. 0.8 ng/mL (p < 0.05) for VIM; 7.5 vs. 0.7 ng/mL (p < 0.0001) for VICM; 57 vs. 4 RU/mL (p < 0.001) for anti-CCP. VICM was decreased in response to tocilizumab (2.9-fold, p < 0.0001) and to methotrexate (1.5-fold, p < 0.05) compared with the placebo, while anti-CCP was not. Serum VIM was also modulated by both drugs, although to a lesser degree. A high baseline level of VICM was predictive of a low disease activity response at week 8. In conclusion, VICM can differentiate between RA and healthy donors in a similar manner to anti-CCP; furthermore, VICM is also a pharmacodynamic marker. [ABSTRACT FROM AUTHOR]

Abstract Background Musculoskeletal (MSK) symptoms are among the commonest reasons for primary care assessments; however, few individuals will be diagnosed with an inflammatory arthritis (IA) within the following year. The purpose of this study was to investigate, in individuals with new MSK symptoms, the association between patient factors and risk of progression to IA, in order to optimise primary care referrals to rheumatology. Methods Individuals ≥16 years old with new non-specific MSK symptoms and no clinical synovitis were recruited by primary care across the UK from July 2007 until May 2019. Those testing positive for the anti-CCP2 assay (anti-CCP+) were invited to Leeds for follow-up. Subjects with a negative result (anti-CCP−) were sent a 1-year questionnaire, and general practitioners were contacted to confirm whether the individual had been diagnosed with an IA by a rheumatologist. Predictors for progression were assessed using multivariable regression analysis. Results Six thousand seven hundred eighty individuals were recruited: 3% were anti-CCP+, of whom 45% progressed to IA, predominantly rheumatoid arthritis. Anti-CCP+ participants with high antibody levels had an odds ratio (OR) for progression to IA of 9.42 [P < 0.001, 95% CI (3.13–28.30)], hand pain, OR 2.74 [P = 0.043, 95% CI (1.03–7.27)] and foot pain, OR 4.10 [P = 0.003, 95% CI (1.59–10.54)]. In low-level anti-CCP+ individuals, absence of pain in hands or feet had a negative predictive value of 96% for progression to IA. One-year follow-up data were available for 5640 anti-CCP− individuals, of whom 53 were diagnosed with IA (0.93%). Pain in hands, OR 2.51 [P = 0.018, 95% CI (1.17–5.39)] or knees, OR 3.03 [P = 0.003, 95% CI (1.47–6.25)] were associated with development of IA within 12 months. Conclusions This is the largest prospective primary care study of individuals at risk of IA, and the first one to prospectively investigate the outcome of MSK symptoms in a large anti-CCP− cohort. High anti-CCP levels and pain in hands/feet indicated an increased likelihood of progression to IA. In patients with low anti-CCP level and no pain in the hands/feet, progression is unlikely. In anti-CCP− patients, those with hand or knee pain were at increased risk of progression. This study demonstrates that routinely available tests and joint symptoms provide useful discrimination that may be used to prioritise referrals to rheumatology and avoid a delayed diagnosis. Trial registration NCT, NCT02012764 . Registered 25 January 2007.

• Optical biosensors were critically reviewed, including ECL, SERS-based, and SPR-based biosensors. • Lateral flow immunoassays (LFIA) as point-of-care (POC) rapid tests were discussed. • Amperometric and label-free electrochemical biosensors developed for anti-CCP were analyzed. • The clinical significance of these biosensors and their advantages and disadvantages were demonstrated. • Various signal amplification systems with their peptide sequences and modifiers were revealed. Biosensors are unique analytical tools for the detection of biomarkers. Of these, autoantibodies against citrullinated proteins (ACPA) are useful for the differential diagnosis of rheumatoid arthritis (RA). The autoantibodies may be detected by immunoassay technology using synthetic cyclic citrullinated peptides (CCP), ie, anti-CCP. Recently, several biosensors have been developed for anti-CCP using CCP and mutated citrullinated vimentin (MCV) as recognition elements. In this review we highlight all currently available ACPA biosensor technology including those based on fluorescence, chemiluminescence, electrochemiluminescence (ECL), surface-enhanced Raman scattering (SERS)-based, surface plasmon resonance (SPR), lateral flow immunoassays (LFIA), and electrochemical. We explore various peptides as recognition elements, electrode modifiers and signal amplification systems thus providing new opportunities for next-generation biosensor design in RA. [ABSTRACT FROM AUTHOR]

Measurement of two groups of autoantibodies, rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) have gained increasing significance in the diagnosis and classification of rheumatoid arthritis (RA) over the last 65 years. Despite this rising importance of autoimmune serology in RA, there is a palpable lack of harmonization between different commercial RF and ACPA tests. While a minimal diagnostic specificity has been defined for RF tests, which almost always are related to an international reference preparation, neither of this applies to ACPA. Especially assays with low diagnostic specificity are associated with very low positive predictive values or post-test probabilities in real world settings. In this review we focus on issues of practical bearing for the clinical physician diagnosing patients who potentially have RA, or treating patients diagnosed with RA. We advocate that all clinically used assays for RF and ACPA should be aligned to a common diagnostic specificity of 98-99% compared to healthy controls. This high and rather narrow interval corresponds to the diagnostic specificity seen for many commercial ACPA tests, and represents a specificity that is higher than what is customary for most RF assays. Data on antibody occurrence harmonized in this way should be accompanied by test result-specific likelihood ratios for the target diagnosis RA on an ordinal or interval scale, which will provide the clinical physician with more granular and richer information than merely relating numerical values to a single cut-off point. As many physicians today are used to evaluate autoantibodies as positive or negative on a nominal scale, the introduction of test result-specific likelihood ratios will require a change in clinical mindset. We also discuss the use of autoantibodies to prognosticate future arthritis development in at-risk patients as well as predict severe disease course and outcome of pharmacological treatment. [ABSTRACT FROM AUTHOR]

Objectives: An increased prevalence of periodontitis and perturbation of the oral microbiome has been identified in patients with rheumatoid arthritis (RA). The periodontal pathogen Porphyromonas gingivalis may cause local citrullination of proteins, potentially triggering anti-citrullinated protein antibody production. However, it is not known if oral dysbiosis precedes the onset of clinical arthritis. This study comprehensively characterised the oral microbiome in anti-cyclic citrullinated peptide (anti-CCP) positive at-risk individuals without clinical synovitis (CCP+at risk).Methods: Subgingival plaque was collected from periodontally healthy and diseased sites in 48 CCP+at risk, 26 early RA and 32 asymptomatic healthy control (HC) individuals. DNA libraries were sequenced on the Illumina HiSeq 3000 platform. Taxonomic profile and functional capability of the subgingival microbiome were compared between groups.Results: At periodontally healthy sites, CCP+at risk individuals had significantly lower microbial richness compared with HC and early RA groups (p=0.004 and 0.021). Microbial community alterations were found at phylum, genus and species levels. A large proportion of the community differed significantly in membership (523 species; 35.6%) and structure (575 species; 39.1%) comparing CCP+at risk and HC groups. Certain core species, including P. gingivalis, had higher relative abundance in the CCP+at risk group. Seventeen clusters of orthologous gene functional units were significantly over-represented in the CCP+at risk group compared with HC (adjusted p value <0.05).Conclusion: Anti-CCP positive at-risk individuals have dysbiotic subgingival microbiomes and increased abundance of P. gingivalis compared with controls. This supports the hypothesis that the oral microbiome and specifically P. gingivalis are important in RA initiation. [ABSTRACT FROM AUTHOR]

Objectives: Rheumatoid arthritis (RA)-specific anti-citrullinated protein/peptide antibodies (ACPAs) might contribute to bone loss and arthralgia before the onset of joint inflammation. We aimed to dissect additional mechanisms by which ACPAs might contribute to development of joint pathology.Methods: Fibroblast-like synoviocytes (FLS) were isolated from the synovial membrane of patients with RA. The FLS cultures were stimulated with polyclonal ACPAs (anti-CCP-2 antibodies) purified from the peripheral blood of patients with RA or with monoclonal ACPAs derived from single synovial fluid B cells. We analysed how ACPAs modulate FLS by measuring cell adhesion and mobility as well as cytokine production. Expression of protein arginine deiminase (PAD) enzymes and protein citrullination were analysed by immunofluorescence, and signal transduction was studied using immunoblotting.Results: Challenge of FLS by starvation-induced stress or by exposure to the chemokine interleukin-8 was essential to sensitise the cells to ACPAs. These challenges led to an increased PAD expression and protein citrullination and an ACPA-mediated induction of FLS migration through a mechanism involving phosphoinositide 3-kinase activation. Inhibition of the PAD enzymes or competition with soluble citrullinated proteins or peptides completely abolished the ACPA-induced FLS migration. Different monoclonal ACPAs triggered distinct cellular effects in either fibroblasts or osteoclasts, suggesting unique roles for individual ACPA clones in disease pathogenesis.Conclusion: We propose that transient synovial insults in the presence of a certain pre-existing ACPA repertoire might result in an ACPA-mediated increase of FLS migration. [ABSTRACT FROM AUTHOR]

Abstract Background Infection by common viruses has long been discussed in the aetiology of a number of autoimmune diseases, including rheumatoid arthritis (RA). However, studies investigating this hypothesis in RA show conflicting results. These studies often lack well-matched control populations, and many do not include data on autoantibodies, genetic risk factors and other environmental factors, which are known to contribute to disease only in subgroups of patients. In the present study, we have therefore examined the role of Epstein-Barr virus (EBV), cytomegalovirus (CMV) and parvovirus B19 (B19) in RA aetiology, by analysing anti-viral antibodies in relation to anti-citrullinated protein antibodies (ACPA), smoking, HLA-DRB1 shared epitope (SE) alleles, and clinical parameters, in both RA patients and matched controls. Methods Anti-viral antibodies were measured by ELISA in serum samples from 990 RA patients and 700 controls from the Swedish population-based Epidemiological Investigation of RA (EIRA) cohort. Data on ACPA, smoking, SE, inflammation (C-reactive protein) and disease activity score in 28 joints (DAS28) was obtained from the EIRA database. Fisher’s exact test, the chi-squared test, and the Mann-Whitney U test were used to calculate differences in anti-viral antibody frequencies and levels; unconditional logistic regression was used to determine the association of anti-viral antibodies with different RA subsets. Results Antibodies against all viruses were highly prevalent in EIRA, with no major differences detected between ACPA-positive RA, ACPA-negative RA and controls. However, both anti-B19 and anti-EBV IgG levels were significantly lower in ACPA-positive RA compared to controls, and there were significant interactions between low levels of anti-B19 and anti-EBV antibodies and SE in the development of ACPA-positive RA. Conclusion We could not detect an association between RA and elevated anti-viral antibody levels, for any of the three common viruses, EBV, CMV or B19. On the contrary, our study demonstrated association between low anti-EBV/anti-B19 antibody levels and ACPA-positive RA, in particular when HLA-DRB1 SE was present. These data could potentially suggest that high anti-viral antibody levels would be protective against ACPA-positive RA. Further investigations are required to address the mechanisms behind these findings.

Objects: Although the association of cigarette smoking (CS) with susceptibility to rheumatoid arthritis (RA) has been established, the impact of CS on anticitrullinated cyclic peptide/protein antibody (ACPA) and rheumatoid factor (RF) levels in RA has yet been clear, especially in relation to shared epitope (SE) alleles.Methods: A total of 6239 subjects, the largest Asian study ever, from two independent Japanese cohorts were enrolled. Precise smoking histories, levels of ACPA and RF, and HLA-DRB1 allele status were withdrawn from databases. Associations between CS and high ACPA or RF levels, defined by the top quartiles, were evaluated. The effect of HLA-DRB1 alleles on the association was further investigated.Results: CS at RA onset conferred the risks of high levels of both antibodies, especially RF (OR 2.06, p=7.4×10-14; ACPA, OR 1.29, p=0.012), suggesting that RF level is more sensitive to CS than ACPA level. The patients who had quitted CS before RA onset showed a trend of decreased risks of developing high levels of ACPA or RF, and the risks steadily decreased according to the cessation years. The association of CS with high ACPA level was observed only in subjects carrying SE alleles, while the association of high RF level was observed regardless of SE.Conclusions: CS confers the risks of high autoantibody levels in RA in different manners; CS interacts with SE alleles on ACPA level, while CS impacts on RF level despite SE allele. These data suggest novel distinct production mechanisms of RF and ACPA. [ABSTRACT FROM AUTHOR]

Background:Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative coccobacillus recognized as a pathogen in periodontitis and infective endocarditis. By producing a toxin (leukotoxin A, LtxA) that triggers global hypercitrullination in neutrophils, Aa has been recently linked to rheumatoid arthritis (RA) pathogenesis. Although mechanistic and clinical association studies implicate Aa infection in the initiation of autoimmunity in RA, direct evidence in humans is lacking.Case:We describe a 59-year-old man with anti-citrullinated protein antibody (ACPA)-positive RA who presented for evaluation of refractory disease. He was found to have Aa endocarditis. Following antibiotic treatment, joint symptoms resolved and ACPAs normalized. Given the implications for RA immunopathogenesis, we further investigated the bacterial, genetic and immune factors that may have contributed to the patient's clinical and autoimmune phenotypes.Methods:DNA was extracted from serum and used to amplify the Aa leukotoxin (ltx) promoter region by PCR, which was further analyzed by Sanger sequencing. High-resolution identification of HLA alleles was performed by sequenced based typing (SBT). TNF-α, IFN-γ, GM-CSF, IL-1β, IL-6, IL-8, IL-17A, IL-18, IL-21, and IL-22 were quantified in serum by a multiplex immunoassay. IgG and IgA antibodies to Aa LtxA were assayed by ELISA.Results:Aa genotyping confirmed infection with a highly leukotoxic strain carrying a 530-bp ltx promoter deletion, shown to result in 10- to 20-fold higher bacterial expression of LtxA. Immuno-phenotyping showed high anti-LtxA antibodies, elevated cytokines implicated in RA pathogenesis (Th1/Th17), and specific host susceptibility conferred by three HLA alleles strongly linked to ACPAs and RA (DRB1*04:04, DRB1*15:01, and DPB1*04:01). One year after eradication of Aa, the patient remained free of arthritis and anti-CCP antibodies.Conclusion: In the context of genetic risk for RA, systemic subacute infection with a leukotoxic strain of Aa can drive ACPA production and a clinical phenotype similar to RA.

Background: Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative coccobacillus recognized as a pathogen in periodontitis and infective endocarditis. By producing a toxin (leukotoxin A, LtxA) that triggers global hypercitrullination in neutrophils, Aa has been recently linked to rheumatoid arthritis (RA) pathogenesis. Although mechanistic and clinical association studies implicate Aa infection in the initiation of autoimmunity in RA, direct evidence in humans is lacking. Case: We describe a 59-year-old man with anti-citrullinated protein antibody (ACPA)-positive RA who presented for evaluation of refractory disease. He was found to have Aa endocarditis. Following antibiotic treatment, joint symptoms resolved and ACPAs normalized. Given the implications for RA immunopathogenesis, we further investigated the bacterial, genetic and immune factors that may have contributed to the patient's clinical and autoimmune phenotypes. Methods: DNA was extracted from serum and used to amplify the Aa leukotoxin (ltx) promoter region by PCR, which was further analyzed by Sanger sequencing. High-resolution identification of HLA alleles was performed by sequenced based typing (SBT). TNF-α, IFN-γ, GM-CSF, IL-1β, IL-6, IL-8, IL-17A, IL-18, IL-21, and IL-22 were quantified in serum by a multiplex immunoassay. IgG and IgA antibodies to Aa LtxA were assayed by ELISA. Results: Aa genotyping confirmed infection with a highly leukotoxic strain carrying a 530-bp ltx promoter deletion, shown to result in 10- to 20-fold higher bacterial expression of LtxA. Immuno-phenotyping showed high anti-LtxA antibodies, elevated cytokines implicated in RA pathogenesis (Th1/Th17), and specific host susceptibility conferred by three HLA alleles strongly linked to ACPAs and RA (DRB1*04:04, DRB1*15:01, and DPB1*04:01). One year after eradication of Aa , the patient remained free of arthritis and anti-CCP antibodies. Conclusion: In the context of genetic risk for RA, systemic subacute infection with a leukotoxic strain of Aa can drive ACPA production and a clinical phenotype similar to RA. [ABSTRACT FROM AUTHOR]

Abstract: Aim: Patients with rheumatoid arthritis (RA) and co‐existent bronchiectasis (BRRA) have a five‐fold increased mortality compared to rheumatoid arthritis alone. Yet previous studies have found no difference in clinical and serological markers of RA disease severity between BRRA patients and RA alone. However, RA disease activity measures such as Disease Activity Score of 28 joints – C‐reactive protein (DAS28‐CRP) and anti‐cyclic citrullinated peptide antibodies (anti‐CCP) have not been studied, so we assessed these parameters in patients with BRRA and RA alone. Methods: BRRA patients (n = 53) had high‐resolution computed tomography proven bronchiectasis without any interstitial lung disease and ≥ 2 respiratory infections/year. RA alone patients (n = 50) had no clinical or radiological evidence of lung disease. DAS28‐CRP, rheumatoid factor (immunoglobulin M) and anti‐CCP were measured in all patients, together with detailed clinical and radiology records. Results: In BRRA, bronchiectasis predated RA in 58% of patients. BRRA patients had higher DAS28 scores (3.51 vs. 2.59), higher levels of anti‐CCP (89% vs. 46%) and rheumatoid factor (79% vs. 52%) (P = 0.003) compared to RA alone. Where hand and foot radiology findings were recorded, 29/37 BRRA (78%) and 13/30 (43%) RA alone had evidence of erosive change (P = 0.003). There were no significant differences between groups in smoking history or disease‐modifying anti‐rheumatic drug/biologic therapy. Conclusions: Increased levels of RA disease activity, severity and RA autoantibodies are demonstrated in patients with RA and co‐existent bronchiectasis compared to patients with RA alone, despite lower tobacco exposure. This study demonstrates that BRRA is a more severe systemic disease than RA alone. [ABSTRACT FROM AUTHOR]

Anti-citrullinated protein autoantibodies (ACPAs) are the major autoantibodies in rheumatoid arthritis (RA). Anti-citrullinated protein autoantibodies are directed against different citrullinated antigens, including filaggrin, fibrinogen, vimentin, and collagen. Presence of ACPA is associated with joint damage and extra-articular manifestations, suggesting that ACPAs are most likely pathogenic autoantibodies in RA. In vitro, ACPAs induce macrophage tumor necrosis factor alpha (TNF-α) production, osteoclastogenesis, and complement activation. These autoantibodies also induce the formation of neutrophil extracellular traps (NETs). Additionally, ACPAs induce pathogenic cytokines expression and oxidative stress in immune cells derived from RA patients. The aim of this review is to show the pathogenic roles of these autoantibodies in RA. [ABSTRACT FROM AUTHOR]

Objective. To investigate whether subfamilies of the RA-specific autoantibodies to human citrullinated fibrinogen (AhFibA) differentially associate with the RA risk factors, HLA-DRB1 shared epitope containing alleles (SE alleles) and cigarette smoking, and thus help to predict the disease outcome. Methods. AhFibA and their anti-α36-50Cit and anti-β60-74Cit subfamilies were assayed by ELISA, at baseline, in the French ESPOIR (Etude et Suivi des Polyarthrites Indifférenciées Récentes) cohort composed of undifferentiated arthritides and RA patients of <6 months' duration. Cigarette smoking, SE alleles' presence, DAS28, HAQ and modified Sharp-van der Heijde Score data were obtained at baseline, and after follow-up. Results. After 3 years, 701 patients were classified as having RA according to the ACR/EULAR 2010 criteria. Among them, 349 (50%), 203 (29%) and 257 (37%) were AhFibA-, anti-α36-50Cit- and anti-β60-74Cit-positive, respectively. The presence and titres of AhFibA and their subfamilies similarly associated with SE alleles, irrespective of their fine specificity, without significant effect of smoking. Neither their presence nor their titre was associated with DAS28 or HAQ. The presence of at least one subfamily was associated with a faster Sharp/van der Heijde score progression, albeit without correlation with the titre. Conclusion. AhFibA and their main subfamilies are similarly associated with SE alleles without additional effect of smoking. Whatever their fine specificity was, their presence (but not their titre) similarly constituted a marker of faster joint destruction. [ABSTRACT FROM AUTHOR]

OBJETIVOS: Avaliar a associação do anticorpo antipeptídeo citrulinado cíclico (anti-CCP) com distintos parâmetros clínicos, sorológicos e radiológicos. MÉTODOS: Anti-CCP e fator reumatóide (FR) foram pesquisados no soro de 100 pacientes com artrite reumatóide (AR). A atividade da doença foi definida por meio de um índice combinado compreendendo cinco parâmetros: número de juntas inflamadas, número de juntas doloridas, rigidez matinal, escala visual analógica (EVA) de dor e velocidade de hemossedimentação (VHS). A capacidade funcional foi medida pelo índice HAQ (Health Assessment Questionnaire) e a classe funcional foi determinada mediante aplicação dos critérios revisados do American College of Rheumatology (ACR), de 1991. Erosão e pinçamento articular foram graduados pelo índice de Sharp modificado. A análise estatística empregou os testes do Qui-quadrado, Mann Whitney e Kruskal-Wallis. RESULTADOS: Nenhum dos dois anticorpos demonstrou associação significativa com atividade da doença, sexo, idade de início da doença, presença de nódulos subcutâneos e síndrome de Sjögren. A média de idade foi significativamente menor nos pacientes com AR anti-CCP positivos. A positividade para o FR e anti-CCP foi maior nos pacientes com AR com menos de 50 anos em comparação com os pacientes com mais de 50 anos. A AR de início recente (< 2 anos) não se associou a uma maior prevalência de soropositividade para o anti-CCP e FR. O anti-CCP apresentou uma correlação positiva moderada com o FR. Houve uma correlação direta entre o anti-CCP e a VHS e a proteína C reativa (PCR). Houve também uma correlação direta entre o FR, a VHS e a PCR. A classificação funcional dos critérios revisados do ACR de 1991 não se associou a qualquer dos dois auto-anticorpos. O índice de HAQ não se correlacionou com a atividade da doença, duração da doença, positividade do FR e atividade medida pela PCR, mas associou-se nitidamente à positividade do anti-CCP e à atividade medida pelo VHS. Os índices de Sharp para erosão e pinçamento se associaram à positividade do anti-CCP. Tal associação não foi evidenciada com a positividade do FR. CONCLUSÃO: Embora o anti-CCP apresente boas propriedades diagnósticas, ele não apresenta associação com a atividade da doença, sexo, idade de início da doença, tempo de evolução de doença, presença de nódulos subcutâneos, síndrome de Sjögren ou classificação funcional do ACR de 1991. Houve associação da positividade do anti-CCP com a menor idade dos pacientes, fator reumatóide, VHS, PCR, índice de HAQ e índices de Sharp para erosão e pinçamento.OBJECTIVE: Evaluate the association of Anti-Cyclic Citrullinated Peptide Antibody (anti-CCP) with distinct clinic, serological and radiological parameters. METHODS: anti-CCP and rheumatoid factor (RF) were determined in the serum of 100 patients with rheumatoid arthritis (RA). Disease activity was defined by means of a combined index with five parameters: number of swollen joints, number of painful joints, morning stiffness, pain visual analogue scale (VAS), and erythrocyte sedimentation rate (ESR). Functional capacity was measured by (Health Assessment Questionnaire) HAQ index and the functional class was ascribed according to American College of Rheumatology criteria (1991). Articular erosion and narrowing were estimated by the modified Sharp's index. Statistical analysis was performed by chi-square, Mann-Whitney, and Kruskal-Wallis tests. A value of less 0.05 was considered significant. RESULTS: None of the two antibodies showed association with disease flare, gender, age in the time of diagnosis, secondary Sjögren's syndrome or subcutaneous nodules. The mean age was significantly lower in RA patients with positive anti-CCP. The RF and anti-CCP positivity was higher in RA patients below 50 years old than patients above 50 years old. The early RA, up to 2 years of evolution, was not associated with a higher prevalence of anti-CCP and RF reactivity. Anti-CCP showed direct moderate correlation to RF and also direct correlation to ESR and CRP. FR reactivity showed direct correlation to ESR and CRP. Functional class showed no association with neither autoantibodies. HAQ index showed correlation with anti-CCP-positive patients and activity assessed by ESR, but did not show association with disease activity, disease duration, presence of the RF and activity assessed by ESR. Sharp's erosion and narrowing index showed association to presence of anti-CCP, but not with RF positive patients. CONCLUSIONS: Although anti-CCP displays good diagnosis properties for RA, it appears not to be associated with activity disease, gender, age at the disease beginning, disease evolution, presence of the secondary Sjögren's syndrome and subcutaneous nodules or functional class. Anti-CCP reactivity showed association with early patients, RF positivity, ESR, CRP, HAQ index or Sharp'erosion and narrowing index.

Aim 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). Method 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. Results 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). Conclusion 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. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a chronic autoimmune disorder of unknown aetiology resulting in inflammation of the synovium, cartilage and bone. The disease has a heterogeneous character, consisting of clinical subsets of anti-citrullinated protein antibody (ACPA)-positive and APCA-negative disease. Although, the pathogenesis of RA is incompletely understood, genetic factors play a vital role in susceptibility to RA as the heritability of RA is between 50 and 60%, with the human leukocyte antigen (HLA) locus accounting for at least 30% of overall genetic risk. Non-HLA genes, i.e. tumour necrosis factor- α ( TNF- α) within the MHC (major histocompatibility complex) have also been investigated for association with RA. Although, some contradictory results have originated from several studies on TNF- α gene, the data published so far indicate the possible existence of TNF- α gene promoter variants that act as markers for disease severity and response to treatment in RA. The correlation of HLA and non-HLA genes within MHC region is apparently interpreted. A considerable number of confirmed associations with RA and other autoimmune disease susceptibility loci including peptidylarginine deiminase type 4 ( PADI4), protein tyrosine phosphatase non-receptor type 22 ( PTPN22), signal transducer and activator of transcription ( STAT4), cluster of differentiation 244 ( CD244) and cytotoxic T lymphocyte-associated antigen 4 ( CTLA4), located outside the MHC have been reported recently. In this review, we aim to give an update on recent progress in RA genetics, the importance of the combination of HLA-DRB1 alleles, non-HLA gene polymorphism, its detection and autoantibodies as susceptibility markers for early RA disease. [ABSTRACT FROM AUTHOR]

Anti-citrullinated protein/peptide antibodies (ACPA) are the principal autoantibody system associated with rheumatoid arthritis (RA), with diagnostic sensitivity of 70% and specificity of 95%. Current testing for ACPA uses the anti-cyclic citrullinated peptide assay (anti-CCP) which measures a generalized reactivity with citrulline-containing peptides, thus giving no insight into reactivity to specific RA antigens. Of these, the best characterized are, α-enolase, fibrinogen/fibrin, vimentin, Type 2 collagen and filaggrin, antibodies to each of which are found in approximately 30-60% of RA cases. Given reports of cross-reactivity between citrullinated antigens, we discuss whether or not measuring these specific antibodies could aid: clinical diagnosis, identification of clinical subsets and drug responses, or provide insight into pathogenic mechanisms or etiology of RA. [ABSTRACT FROM AUTHOR]

Recently, it has been found that some lupus patients may have anti-cyclic citrullinated peptide antibodies (anti-CCP), although the clinical significance of such finding is not well established. Systemic lupus erythematosus (SLE) patients may have joint complaints that are very similar to those observed in rheumatoid arthritis (RA). In early stages of disease, this form of arthritis can be difficult to differentiate from RA, so it is not rare that some SLE patients are initially misdiagnosed to have this disease. This study aims to investigate the prevalence of anti-CCP in SLE patients from Southern Brazil and its association with clinical and serological profiles. One hundred nine SLE patients were studied for anti-CCP and compared with data of 156 RA patients and 100 healthy volunteers. Comparison of clinical and autoantibody profile of anti-CCP-positive and anti-CCP-negative SLE patients was done. All SLE patients positive of anti-CCP were submitted to hand and feet X-rays. Anti-CCP was positive in 15 of 109 SLE patients, and one of them had confirmed the diagnosis of rhupus. This prevalence was significantly higher than in healthy controls ( p = 0.0004) and lower than in RA patients ( p < 0.0001). No relationship could be found with clinical profile, including joint complaints. SLE patients with anti-CCP had higher prevalence of anti-Ro ( p = 0.02) and anti-La ( p = 0.004) autoantibodies, in comparison with those negative to anti-CCP. We found that 13.7 % of Brazilian patients with SLE have positive anti-CCP. Patients with anti-CCP showed higher prevalence of anti-Ro and anti-La autoantibodies than those negative for anti-CCP. Only a careful and prolonged follow-up will reveal the real clinical value of these markers in each patient individually. [ABSTRACT FROM AUTHOR]

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 clinical remission during follow-up of 3 years The presence of autoantibodies in early RA has no predictive value for clinical remission in early RA. [ABSTRACT FROM AUTHOR]

Abstract: Sjögren Syndrome (SS) is a systemic, autoimmune disorder characterized by lymphocytic infiltration of the exocrine glands. Different clinical associations have been described for each of the diverse autoantibodies found in SS patients. Antibodies directed against the Ro/La ribonucleoprotein complexes have been correlated with younger age, more severe dysfunction of the exocrine glands and a higher prevalence of extraglandular manifestations. Anti-nuclear antibodies and rheumatoid factors have been associated to extraglandular manifestations and an active immunological profile, while cryoglobulins are markers of more severe disease and correlate to lymphoma development and death. Antibodies to cyclic citrullinated peptides are scarce in SS and have been linked in some cases to the development of non-erosive arthritis. Furthermore, the presence of anti-mitochondrial antibodies and anti-smooth muscle antibodies in the sera of primary SS patients is considered indicative of primary biliary cirrhosis and autoimmune hepatitis, respectively. In addition, anti-centromere antibodies have been associated with a clinical phenotype intermediate between primary SS and systemic sclerosis, while antibodies against carbonic anhydrase have been related to renal tubular acidosis. Finally, an association of anti-muscarinic antibodies with cytopenias and a higher disease activity has also been described in primary SS. In conclusion, although not all of the above mentioned antibodies are useful for predicting distinct patient subgroups in SS, knowledge of the clinical associations of the different autoantibody specificities encountered in SS can advance our understanding of the disease and improve patient management. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a systemic inflammatory disorder affecting 1% of the US population. Patients can have extra-articular manifestations of their disease and the lungs are commonly involved. RA can affect any compartment of the respiratory system and high resolution computed tomography (HRCT) of the lung is abnormal in over half of these patients. Interstitial lung disease is a dreaded complication of RA. It is more prevalent in smokers, males, and those with high antibody titers. The pathogenesis is unknown but data suggest an environmental insult in the setting of a genetic predisposition. Smoking may play a role in the pathogenesis of disease through citrullination of protein in the lung leading to the development of autoimmunity. Patients usually present in middle age with cough and dyspnea. Pulmonary function testing most commonly shows reduced diffusion capacity for carbon monoxide and HRCT reveals a combination of reticulation and ground glass abnormalities. The most common pattern on HRCT and histopathology is usual interstitial pneumonia (UIP), with nonspecific interstitial pneumonia seen less frequently. There are no large-scale well-controlled treatment trials. In severe or progressive cases, treatment usually consists of corticosteroids with or without a cytotoxic agent for 6 months or longer. RA interstitial lung disease is progressive; over half of patients show radiographic progression within 2 years. Patients with a UIP pattern on biopsy have a survival similar to idiopathic pulmonary fibrosis [ABSTRACT FROM AUTHOR]

Objective: Rheumatoid arthritis (RA) is a systemic autoimmune disease of unknown etiology with chronic joint inflammation. The major autoantibody detected in RA patients is rheumatoid factor (RF). RF has demonstrated lower sensitivity for the diagnosis of RA. The aims of this study were to evaluate the diagnostic performance of anti-cyclic citrullinated peptide (anti-CCP) by ELISA method and compared those with the diagnostic performance of RF test in patients with RA, and to determine how frequently anti-CCP antibodies can be found in patients with asthma, systemic lupus erythematosus, and in normal blood donors and control groups. Materials and Methods: Diagnostic performance of anti-CCP assay by enzyme linked immunosorbent assay (ELISA) was compared with that of RF by nephelometry test. RF and anti-CCP tests were performed in 23 RA patient, 23 healthy control groups, 20 asthma, 7 systemic lupus erythematosus, and 15 normal blood donors. Results: However, anti-CCP antibody showed positivity in 95.7% of RA patient and 4.3% of healthy control groups, this autoantibody has demonstrated negativity for asthma, systemic lupus erythematosus, and normal blood donors. In the RA groups, sensitivity and specificity were 95.7% and 95.7% for anti-CCP, and 100% and 78.3% for RF antibody, respectively. Conclusion: It was considered that anti-CCP could be very useful serological assay for the diagnosis of RA, because anti-CCP revealed higher diagnostic specificity than RF. [ABSTRACT FROM AUTHOR]