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Multi-ancestry genome-wide association analyses identify 124 risk loci for rheumatoid arthritis, of which 34 are novel. A polygenic risk score based on multi-ancestry data showed comparable performance between populations of European and East Asian ancestries.Rheumatoid arthritis (RA) is a highly heritable complex disease with unknown etiology. Multi-ancestry genetic research of RA promises to improve power to detect genetic signals, fine-mapping resolution and performances of polygenic risk scores (PRS). Here, we present a large-scale genome-wide association study (GWAS) of RA, which includes 276,020 samples from five ancestral groups. We conducted a multi-ancestry meta-analysis and identified 124 loci (P < 5 x 10(-8)), of which 34 are novel. Candidate genes at the novel loci suggest essential roles of the immune system (for example, TNIP2 and TNFRSF11A) and joint tissues (for example, WISP1) in RA etiology. Multi-ancestry fine-mapping identified putatively causal variants with biological insights (for example, LEF1). Moreover, PRS based on multi-ancestry GWAS outperformed PRS based on single-ancestry GWAS and had comparable performance between populations of European and East Asian ancestries. Our study provides several insights into the etiology of RA and improves the genetic predictability of RA.

A 46-year old Ghanaian man presented with immobilizing arthralgias in all joints except the forefoot, with a periarticular swelling most pronounced around the wrists and ankles. He had erythema nodosum and hilar lymphadenopathy on chest radiograph. We diagnosed Löfgren syndrome. The polyarthralgia recovered quickly with prednisone treatment.

Using the Immunochip custom SNP array, which was designed for dense genotyping of 186 loci identified through genome-wide association studies (GWAS), we analyzed 11,475 individuals with rheumatoid arthritis (cases) of European ancestry and 15,870 controls for 129,464 markers. We combined these data in a meta-analysis with GWAS data from additional independent cases (n = 2,363) and controls (n = 17,872). We identified 14 new susceptibility loci, 9 of which were associated with rheumatoid arthritis overall and five of which were specifically associated with disease that was positive for anticitrullinated peptide antibodies, bringing the number of confirmed rheumatoid arthritis risk loci in individuals of European ancestry to 46. We refined the peak of association to a single gene for 19 loci, identified secondary independent effects at 6 loci and identified association to low-frequency variants at 4 loci. Bioinformatic analyses generated strong hypotheses for the causal SNP at seven loci. This study illustrates the advantages of dense SNP mapping analysis to inform subsequent functional investigations.

International audience; Recent insights in rheumatoid arthritis (RA) necessitated updating the European League Against Rheumatism (EULAR) RA management recommendations. A large international Task Force based decisions on evidence from 3 systematic literature reviews, developing 4 overarching principles and 12 recommendations (vs 3 and 14, respectively, in 2013). The recommendations address conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs) (methotrexate (MTX), leflunomide, sulfasalazine); glucocorticoids (GC); biological (b) DMARDs (tumour necrosis factor (TNF)-inhibitors (adalimumab, certolizumab pegol, etanercept, golimumab, infliximab), abatacept, rituximab, tocilizumab, clazakizumab, sarilumab and sirukumab and biosimilar (bs) DMARDs) and targeted synthetic (ts) DMARDs (Janus kinase (Jak) inhibitors tofacitinib, baricitinib). Monotherapy, combination therapy, treatment strategies (treat-to-target) and the targets of sustained clinical remission (as defined by the American College of Rheumatology-(ACR)-EULAR Boolean or index criteria) or low disease activity are discussed. Cost aspects were taken into consideration. As first strategy, the Task Force recommends MTX (rapid escalation to 25 mg/week) plus short-term GC, aiming at >50% improvement within 3 and target attainment within 6 months. If this fails stratification is recommended. Without unfavourable prognostic markers, switching to-or adding-another csDMARDs (plus short-term GC) is suggested. In the presence of unfavourable prognostic markers (autoantibodies, high disease activity, early erosions, failure of 2 csDMARDs), any bDMARD (current practice) or Jak-inhibitor should be added to the csDMARD. If this fails, any other bDMARD or tsDMARD is recommended. If a patient is in sustained remission, bDMARDs can be tapered. For each recommendation, levels of evidence and Task Force agreement are provided, both mostly very high. These recommendations intend informing rheumatologists, patients, national rheumatology societies, hospital officials, social security agencies and regulators about EULAR's most recent consensus on the management of RA, aimed at attaining best outcomes with current therapies.

Objective. Early recognition and treatment of RA is associated with an improved outcome. The 2010 ACR/ EULAR criteria for RA identify RA patients earlier than the 1987 ACR criteria. Nevertheless, we recently observed that 24% of the 2010 unclassified arthritis (UA) patients develop RA during follow-up. Here we studied this frequency in other cohorts and evaluated the prognostic accuracy of ACPA and the Leiden prediction rule in 2010 UA patients. Methods. The 2010 UA patients from three Early Arthritis Clinics were studied: 776 from Leiden, 121 from Birmingham and 322 from Amsterdam. Fulfilment of the 1987 ACR criteria during follow-up was studied as the primary outcome. DMARD prescription during the year and having a persistent course of arthritis over 7 years were studied as secondary outcomes in one cohort. The presence of ACPA and the prediction score at baseline were evaluated in relation to these outcomes. Results. In the three cohorts, 24%, 26% and 12%, respectively, of the 2010 UA patients fulfilled the 1987 criteria after 1 year. However, some of these patients already fulfilled the 1987 criteria at baseline. In 1987 and 2010 UA patients, 15%, 21% and 9%, respectively, developed RA (1987) at 1 year. In these patients, 06% of the patients were ACPA positive and 01% had high prediction scores. Consequently a large majority of the UA patients with an unfavourable outcome was not recognized by these prognostic tools. Conclusion. A proportion of 2010 UA patients progress to RA. ACPA and the Leiden prediction rule are not useful in identifying these patients. These results imply that other predictive markers should be developed for 2010 UA patients.

Rare and functional SIAE variants are not associated with autoimmune disease risk in up to 66,924 individuals of European ancestry

Background Anti-citrullinated protein antibodies (ACPA) are the most predictive factor for the development of rheumatoid arthritis (RA). Objective To investigate whether the recognition of citrullinated epitopes changes during disease onset or progression, by studying the fine specificity of ACPA in serum samples collected throughout the disease course, from before the onset of arthritis to longstanding RA. Methods Antibodies recognising five distinct citrullinated antigens were determined by enzyme-linked immunosorbent assay. Serum samples from 36 individuals who had donated blood before and after disease manifestation were used to investigate the development of citrullinated antigen recognition before disease onset. The association of ACPA reactivities with disease outcome was studied using sera from anti-cyclic citrullinated peptide-2 (CCP2)-positive patients with undifferentiated arthritis (UA) who did or did not progress to RA (UA-RA n = 81, or UA-UA n = 35). To investigate the ACPA recognition profile in patients with RA over a prolonged period of time, baseline serum samples from 68 patients were compared with samples obtained 7 years later. Results The number of recognised citrullinated peptides increased in the period preceding disease onset. At the time of disease manifestation, patients with UA who later developed RA recognised significantly more peptides than UA-UA patients. At later stages of the disease course, the ACPA fine specificity did not change. Conclusion Epitope spreading with an increase in the recognition of citrullinated antigens occurs before the onset of RA. Immunological differences in ACPA fine specificity between UA-UA patients and UA-RA patients are present at baseline and are associated with the future disease course.

Objective The most cost-effective dosing regimen for rituximab treatment in RA is currently unknown. The objective of this study is to determine whether low rituximab serum levels are associated with progression of structural damage in RA patients. Methods Sixty-two RA patients were treated with rituximab in three different centres. Structural damage was assessed on radiographs of hands and feet before and 1 year after therapy using the Sharp-van der Heijde scoring method (SHS). Patients were divided into progressors vs non-progressors based on different cut-off values. Rituximab serum levels were measured by sandwich ELISA after 4 and 12 weeks (Leiden University Medical Center and University Medical Centre, Utrecht cohorts) or 4 and 16 weeks (Academic Medical Center/University of Amsterdam cohort). Results There was no difference in rituximab levels between progressors and non-progressors 4 weeks and 12 or 16 weeks after initiation of treatment in the different cohorts. There was also no correlation between rituximab levels at week 4 or week 12 or 16 and change in SHS score after 1 year. Conclusion Low rituximab serum levels are not associated with progression of structural damage in RA patients. The results do not support the use of dosages higher than 2 × 1000 mg rituximab to inhibit progression of joint destruction.

Objective The protective effect of HLA–DRB1 alleles on the development of rheumatoid arthritis (RA) is poorly understood. The aim of this study was to perform a meta-analysis of 4 European populations to investigate which HLA–DRB1 alleles are associated with protection in anti–citrullinated protein antibody (ACPA)–positive RA and ACPA-negative RA. Methods Data for >2,800 patients and >3,000 control subjects for whom information on HLA–DRB1 typing and ACPA status was available were collected from 4 European countries: Norway, Sweden, The Netherlands, and Spain. The odds ratios (ORs) and 95% confidence intervals (95% CIs) associated with the different HLA–DRB1 alleles were analyzed in a combined meta-analysis focused on protective alleles and classifications. The analysis of ACPA-positive RA was stratified for the shared epitope (SE) alleles, to correct for skewing due to this association. Results In ACPA-positive RA, the only alleles that conveyed protection after stratification for SE were HLA–DRB1*13 alleles (OR 0.54 [95% CI 0.38–0.77]). The protective effect of the allele classifications based on the DERAA and D70 sequences was no longer present after exclusion of DRB1*13 (for D70, OR 0.97 [95% CI 0.75–1.25]), indicating that DRB1*13, rather than the DERAA or D70 sequence as such, is associated with protection. Among the DRB1*13 alleles, only DRB1*1301 was associated with protection (OR 0.24 [95% CI 0.09–0.59]). Protection appeared to follow a north-to-south gradient, with the strongest association in northern European countries. In ACPA-negative RA, there were no robust associations with HLA–DRB1 alleles. Conclusion Our data do not support any of the classifications of protective alleles and indicate that protection against ACPA-positive RA is predominantly associated with HLA–DRB1*1301.

Background Joint destruction in rheumatoid arthritis (RA) was until recently seen as an irreversible state. Lately, it was found that repair of bone erosions occurs; however, little is known about its prevalence. Objective To investigate the frequency of repair and patients9 characteristics associated with repair in an inception cohort. Patients and methods 250 patients with RA, included in the Leiden Early Arthritis Clinic between 1993 and 2000 and treated with conventional disease-modifying antirheumatic drugs, were studied (mean follow-up 10.1 years). Radiographs obtained annually were scored using the Sharp–van der Heijde method, initially aware of the chronology. Patients with a negative change in erosion scores on subsequent radiographs were selected and their series of radiographs were rescored with concealed time sequence by three readers. Repair was defined as agreement between two readers of a negative change in erosion scores that persisted for at least 2 years. Results Repair was identified in 32 joints in 18 patients (7.2%). Patients with repair had a greater prevalence of autoantibodies (rheumatoid arthritis, anti-citrullinated protein antibody) and a higher level of joint destruction. In the joints with repair, arthritis was absent in the 2 years preceding repair. Conclusions Repair occurred in 7.2% of the patients with RA, particularly in clinically inactive joints in patients with severe destructive disease.

To determine the usefulness of a prediction model for making treatment decisions in early rheumatoid arthritis (RA).In 152 patients with early RA, progression of radiological damage during the first year [Sharp-van der Heijde (SH) score0] was assessed and used to define actual disease outcome. Available variables at baseline were entered in a multivariate regression analysis with progression score as dependent variable. This model was used to predict disease outcome in every patient. Using the standard deviations of the predicted disease outcome, patients were divided into 3 groups: (1) severe disease: high probability (or = 0.8) for progression0, (2) mild disease: high probability (or =0.8) for progressionor = 0, and (3) not classified: no high probability for either option. It was determined how many patients could be classified by using this model.One hundred nine patients (71.7%) showed joint damage progression during the first year. Baseline variables available were: age, sex, duration of symptoms, duration of morning stiffness, patient's global assessment of disease activity, Health Assessment Questionnaire score, swollen and painful joint count, bilateral compression pain in metatarsophalangeals, rheumatoid factor positivity, erythrocyte sedimentation rate, shared epitope positivity, SH-score, and the presence of erosions. The R2 value (approximately variation explained) of the prediction model was 0.36. By using this model 46.3% of patients could be classified as having severe disease, 0% as having mild disease, and 53.7% could not be classified.To be able to make treatment decisions in early RA based on predicted disease outcome, a better prediction of disease outcome is needed, making the search for better prognostic variables urgent.

Objective. The aim of the present study was to analyze α2Macroglobulin/MMP (α2M/MMP) complex formation and to investigate whether MMP activity in α2M/MMP complexes in serum can be used as a disease marker in rheumatoid arthritis (RA). Methods. High and low molecular weight (H/LMW) substrates and inhibitors and size exclusion were used to analyze α2M/MMP complex formation. LMW fluorogenic substrates were used to quantify the level of MMPs in α2M/MMP complexes in the serum of RA patients and healthy controls. Results. Active MMPs were fully inhibited by LMW inhibitor BB94 in the presence of α2M, whereas no inhibition was achieved by HMW inhibitor TIMP-1. Size exclusion analysis showed α2M/MMP complex formation in buffer and in normal plasma spiked with activated MMPs, whichFrom Subject Received Size Categories Beheer-TNO-SharePoint NDIA Weekly Insider 8:00 18 KB indicated α2M/MMP complex formation in the systemic circulation. MMP activity in α2M/MMP complexes in the serum of RA patients was significantly higher than in the serum of healthy controls (P

Ligands for the receptor for advanced glycation endproducts (RAGE) are increased in RA synovial fluid (SF), serum and synovium. Since RAGE is present on fibroblast-like synoviocytes (FLS), the present study investigates whether the RAGE ligands HMGB-1 and AGEs are able to stimulate the characteristic, pathological invasive behaviour of these cells. FLS were obtained during joint replacement surgery. FLS were seeded in serum free medium with HMGB-1 or glycated albumin (BSA-AGE) on transwell filters coated with Matrigel. The lower compartment contained medium with serum as a chemoattractant. After three days, the percentage of invading cells was determined and compared to the control invasion. Stimulation with HMGB-1 increased invasiveness to 125% compared to the control (p = 0.001). Addition of anti-RAGE antibody reduced this back to baseline (98%, p = 0.002). Stimulation with BSA-AGE, another RAGE ligand, increased invasiveness to 150% compared to the control (p = 0.003). Addition of anti RAGE was again able to reduce the increased invasiveness back to baseline (95%, p = 0.008). HMGB-1 and BSA-AGE stimulated the invasiveness of RA-FLS by activation of RAGE. As such, RAGE may be an interesting target for therapy directed at the inhibition of synoviocyte activation. © Copyright Clinical and Experimental Rheumatology 2007.