Lack of association between RETN rs1862513 polymorphism and cardiovascular disease in rheumatoid arthritis patients.

OBJECTIVES: To assess the influence of the RETN rs1862513 polymorphism in the risk of cardiovascular (CV) disease and subclinical atherosclerosis in patients with rheumatoid arthritis (RA). METHODS: Six hundred and sixty-eight patients fulfilling the 1987 American College of Rheumatology classification criteria for RA, seen at the rheumatology outpatient clinics of Hospital Xeral-Calde, Lugo, and Hospital San Carlos, Madrid, Spain, were studied. Patients were genotyped for the RETN rs1862513 polymorphism using predesigned TaqMan single nucleotide polymorphism genotyping assay. Also, HLA-DRB1 genotyping was performed using molecular based methods. Carotid intima-media thickness (IMT), flow-mediated endothelium-dependent and endothelium independent vasodilatation, used as surrogate markers of subclinical atherosclerosis, were measured in a subgroup of patients. RESULTS: No significant differences in the genotypic or in the allelic distribution between RA patients with or without CV disease were found. In this regard, we only observed a slight increased frequency of homozygous and heterozygous for the minor allele G (CG+GG genotypes) among patients who experienced CV events compared to those without CV events (53.04% vs. 52.62%, p=0.94). A higher frequency of classic CV risk factors was observed among the carriers of the minor allele G. However, in the adjusted logistic regression model no association between the RETN variant and CV disease was found (p=0.50). Also, when surrogate markers of subclinical atherosclerosis were assessed, in the adjusted ANCOVA model only a trend towards a higher carotid IMT was found among allele G carriers (p=0.06). CONCLUSIONS: RETN rs1862513 polymorphism does not seem to be a genetic risk factor for both clinically evident CV disease and subclinical atherosclerosis in patients with RA.

Role of BANK1 gene polymorphisms in biopsy-proven giant cell arteritis.

OBJECTIVE: Giant cell arteritis (GCA) is a complex polygenic disease in which more than 1 genetic locus is likely to contribute to disease susceptibility and clinical expression. BANK, an adaptor molecule, has been suggested to participate in the B cell antigen receptors-mediated calcium homeostasis. We assessed for the first time the implication of BANK1 functional variants in susceptibility to GCA. METHODS: Two hundred twenty-two patients with biopsy-proven GCA and 534 matched controls were assessed. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for 3 putative functional BANK1 gene polymorphisms (rs17266594 T/C, rs10516487 G/A, rs3733197 G/A) using a TaqMan allele discrimination assay. RESULTS: No significant differences were observed in genotype distribution between patients with biopsy-proven GCA and controls for these 3 gene polymorphisms. A trend for a decreased risk of having GCA was observed in individuals carrying the BANK1 rs3733197 GG genotype (patients with GCA 43.9% compared to 51.6% in controls; p = 0.06, OR 0.73, 95% CI 0.53-1.02). The frequency of BANK1 rs3733197 allele G was marginally decreased in patients with biopsy-proven GCA compared to controls (p = 0.09, OR 0.82, 95% CI 0.64-1.04). Haplotype analysis of 3-single-nucleotide polymorphisms found no statistically significant differences between patients with GCA and controls. No significant differences for the BANK1 gene polymorphisms were found when patients were stratified according to specific clinical features of the disease. CONCLUSION: Our results do not support a major implication of the BANK1 locus in susceptibility to GCA.

Study of functional variants of the BANK1 gene in rheumatoid arthritis.

OBJECTIVE: To investigate 1 functional (rs17266594) and 2 potentially functional (rs10516487 and rs3733197) BANK1 variants, which were previously identified as systemic lupus erythematosus (SLE) susceptibility markers, to test whether they are associated with rheumatoid arthritis (RA). METHODS: Four different cohorts were included in the study: 1,080 RA patients and 1,368 healthy controls from Spain, 278 RA patients and 568 healthy controls from Sweden, 288 RA patients and 287 healthy controls from Argentina, and 288 RA patients and 288 healthy controls from Mexico. Samples were genotyped for BANK1 single-nucleotide polymorphisms (SNPs) using a TaqMan 5'-allele discrimination assay. Statistical analysis comparing allele and genotype distributions was performed with the chi-square test. RESULTS: We did not find a significant association between RA and the rs10516487 and rs17266594 BANK1 polymorphisms. However, there was an increase in the major alleles among RA patients. Similarly, for rs3733197, there was an increase in the major allele among patients in every cohort. Nevertheless, this skewing reached statistical significance in the Spanish (P = 0.01, odds ratio [OR] 1.17 [95% confidence interval (95% CI) 1.03-1.32]) and Argentinean (P = 0.04, OR 1.31 [95% CI 1.00-1.72]) populations. We found a significant association of rs10516487 (P = 0.005, OR 1.15 [95% CI 1.04-1.28]) and rs3733197 (P = 0.0009, OR 1.17 [95% CI 1.07-1.29]) with RA in the pooled analysis. In a 3-SNP haplotype analysis, we found that the major TGG haplotype was significantly associated with RA (P = 0.005, OR 1.14 [95% CI 1.04-1.25]). In addition, we found a common CAA haplotype that was protective against RA (P = 0.0004, OR 0.82 [95% CI 0.74-0.92]). CONCLUSION: These results suggest that BANK1 SNPs and haplotypes may contribute to RA susceptibility with a low risk.