Several susceptibility genes have been associated with systemic lupus erythematosus (SLE) across different populations worldwide. However, data on association between genetic polymorphisms and SLE from Indian population is scarce. We aimed to replicate the association of single nucleotide polymorphisms (SNPs) in ITGAM, TNFSF4, TNFAIP3 and STAT4 genes with susceptibility to SLE in a North Indian population. Three hundred and ninety-four SLE patients and 583 unrelated healthy controls of the same ethnic background were enrolled. All samples were genotyped for SNPs in ITGAM (rs1143679), TNFSF4 (rs2205960), TNFAIP3 (rs5029939) and STAT4 (rs7574865) using TaqMan genotyping assay. At allele level, significant association with susceptibility to SLE was detected with polymorphisms in ITGAM (A vs. G, odds ratio (OR) = 1.73, 95% confidence interval (CI) = 1.30-2.30, p < 0.001), TNFSF4 (T vs. G, OR = 1.33, 95% CI = 1.08-1.64, p < 0.01), TNFAIP3 (G vs. C, OR = 1.91, 95% CI = 1.27-2.85, p < 0.01) and STAT4 (T vs. G, OR = 1.38, 95% CI = 1.13-1.69, p < 0.01). All four SNPs were associated with SLE under a dominant model with an OR of 1.47 (95% CI = 1.07-2.04, p < 0.05) for ITGAM, 1.30 (95% CI = 1.01-1.69, p < 0.05) for TNFSF4, 1.90 (95% CI = 1.25-2.90, p < 0.01) for TNFAIP3 and 1.38 (95% CI = 1.06-1.78, p < 0.05) for STAT4. Under a recessive model, significant association was found with ITGAM (OR = 4.87, 95% CI = 2.17-10.91, p < 0.001), TNFSF4 (OR = 1.84, 95% CI = 1.13-3.00, p < 0.05) and STAT4 (OR = 1.82, 95% CI = 1.19-2.77, p < 0.01). In conclusion, single nucleotide polymorphisms in ITGAM, TNFSF4, TNFAIP3 and STAT4 genes are associated with susceptibility to SLE in a North Indian population.
Keywords: ITGAM; STAT4; Systemic lupus erythematosus; TNFAIP3; TNFSF4; genetic polymorphism.