Objective. This study was undertaken to investigate the previously reported association of the STAT4 polymorphism rs7574865 with rheumatoid arthritis (RA) in 3 different European populations from Spain, Sweden, and The Netherlands, comprising a total of 2,072 patients and 2,474 controls.Methods. Three different cohorts were included in the study: 923 RA patients and 1,296 healthy controls from Spain, 273 RA patients and 285 healthy controls from Sweden, and 876 RA patients and 893 healthy controls from The Netherlands. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the STAT4 single-nucleotide polymorphism rs7574865 using a TaqMan 5 -allele discrimination assay. The chi-square test was performed to compare allele and genotype distributions. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.Results. We observed a significantly increased frequency of the minor T allele in RA patients compared with healthy controls in the Spanish population ( Conclusion. Our findings indicate an association between the STAT4 polymorphism rs7574865 and RA in 3 different populations, from Spain, Sweden, and The Netherlands, thereby confirming previous data.

Objective. Previous studies have shown either a lack of effect of IRF5 polymorphisms or an association of the IRF5 gene in only a minor subset of rheumatoid arthritis (RA) patients in whom anti-citrullinated protein antibodies (ACPAs) are absent. The present study was undertaken to investigate the role of genetic variation in IRF5 in susceptibility to RA.Methods. Nine IRF5 single-nucleotide polymorphisms (SNPs) were studied in 1,338 patients with RA and 1,342 control subjects in analyses of exploratory and replication sample collections, with stratification according to sex and by the presence or absence of ACPAs, rheumatoid factor, the shared epitope, the 620W PTPN22 allele, and erosions. A meta-analysis that included results from previous studies was also carried out.Results. Our findings together with those from previous studies, in a total of 4,620 RA patients and 3,741 controls, showed a significant association of the rs2004640 IRF5 SNP in RA patients as a whole (odds ratio [OR] 0.88, 95% confidence interval [95% CI] 0.83-0.94; P ‫؍‬ 6.5 ؋ 10 ؊5 versus controls). This association was stronger in ACPA؊ patients, but was also present in ACPA؉ patients (from 3 sample collections). Further analysis of our exploratory sample collection showed that only patients in the ACPA؉ and SE؊ group lacked an association with IRF5 SNPs. All of the remaining RA patients (ACPA؊ or SE؉) showed a strong association with IRF5 SNPs, which followed a complex pattern of opposing effects mediated by independent haplotypes. The susceptibility haplotype showed an OR of 1.8 (95% CI 1.4-2.3; P ‫؍‬ 1.2 ؋ 10 ؊6 versus controls), whereas the protective haplotype showed an OR of 0.76 (95% CI 0.6-0.98; P ‫؍‬ 0.046 versus controls).Conclusion. IRF5 polymorphisms seem to influence RA susceptibility in a large subgroup of patients, following a pattern of association very similar to that described in patients with systemic lupus erythematosus.

Objective. Recently, a functional PTPN22 variant (R263Q; rs33996649) was found to be associated with systemic lupus erythematosus (SLE). This study was undertaken to analyze the influence of this polymorphism on the risk of rheumatoid arthritis (RA).Methods. RA patients (n ‫؍‬ 5,579) were recruited from outpatient clinics from 6 different countries (Spain, New Zealand, the UK, Norway, The Netherlands, and Germany). Healthy controls (n ‫؍‬ 5,392) were recruited from the same areas. There was 100% power to detect an effect equivalent to that observed in SLE. Samples were genotyped for the PTPN22 R263Q (rs33996649) and PTPN22 R620W (rs2476601) polymorphisms using a TaqMan 5-allele discrimination assay. The effect of the R263Q variant was analyzed in isolation and in combination with the effect of R620W, using Unphased and Stata 10 software. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were determined. Conclusion. Our findings indicate that the minor allele of the PTPN22 R263Q polymorphism is associated with a lower risk of RA. This association is independent of the well-established association between PTPN22 R620W and RA. Both polymorphisms have an additive effect on the risk of RA. Results. The minor allele

Objective. To determine whether major histocompatibility complex (MHC) polymorphisms are associated with a good or poor response to infliximab therapy in patients with rheumatoid arthritis (RA).Methods. Seventy-eight infliximab-treated patients with RA were genotyped for HLA-DRB1, HLA-DQA1, HLA-DQB1, MHC class I chain-related gene A (MICA) transmembrane polymorphism alleles, and tumor necrosis factor a (TNFa), TNFb, TNFc, TNFd, TNFe, D6S273, HLA-B-associated transcript 2 (BAT2), and D6S2223 microsatellites. Chi-square tests were performed to compare allele proportions between responder and nonresponder patients. A control sample of 342 healthy individuals was also included to detect linkage disequilibrium between pairs of markers.Results. Among responders, the frequency of the TNFa11;b4 minihaplotype was increased (41% versus 16% in nonresponders; P ‫؍‬ 0.01) and that of the D6S273_3 allele was decreased (32% versus 56% in nonresponders; P ‫؍‬ 0.04). The D6S273_4/BAT2_2 pair was much more frequently observed among responders (46% versus 11% in nonresponders; P ‫؍‬ 0.001). When compared with controls, this pair of alleles was found to be associated only with the group of responder patients (46% in responders versus 17% in controls; P ‫؍‬ 0.00002). Most of the time, these markers are present in a DRB1*0404/D6S273_4/BAT2_2/TNFa11;b4 context. No statistically significant differences were observed for MICA and D6S2223 polymorphisms and for shared epitope status.Conclusion. The data suggest that genetic determinants of response to infliximab therapy exist in the HLA complex.

Objective. Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) share some genetic factors such as HLA, PTPN22, STAT4, and 6q23. The aim of this study was to determine whether 9 other SLE genetic factors are also implicated in RA susceptibility.Methods. A characteristic single-nucleotide polymorphism (SNP) in each of 9 genetic factors, ITGAM (rs1143679), C8orf13-BLK (rs13277113), TYK2 (rs2304256), 1q25.1 (rs10798269), PXK (rs6445975), KIAA1542 (rs4963128), MECP2 (rs17435), BANK1 (rs17266594), and LY9 (rs509749), was studied in 1,635 patients with RA and 1,906 control subjects from Spain. The rs7574865 SNP in STAT4 was also included. Analyses were conducted globally and after stratification by sex and clinical features (anti-cyclic citrullinated peptide and rheumatoid factor, shared epitope, rheumatoid nodules, radiographic changes, sicca syndrome, and pneumonitis).Results. No association was observed between RA and any of the 9 newly identified SLE genetic factors. A meta-analysis using previous data was consistent with these results. In addition, there were no significant differences between individuals with and those without each of the clinical features analyzed, except the frequency of the minor allele in the C8orf13-BLK locus that was decreased in patients with sicca syndrome (14.6% versus 22.4% in controls; P ‫؍‬ 0.003).Conclusion. None of the 9 recently identified SLE risk factors showed association with RA. Therefore, common genetic factors affecting the pathogenesis of these 2 disorders seem to be limited, revealing that the genetic component contributes to the different expression of these diseases.Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) share a complex etiology encom-