Association Between Polymorphism Of IRF5 Gene And Clinical Features Of Systemic Lupus Erythematosus In Chinese Han Population

Background Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by autoantibodies production and multisystemic involvement. The exact etiology and pathogenesis is still not clear. Environmental and hereditary factors seem to play important roles in the development of the disease. We have identified susceptibility genes IRF5 for SLE in a recent genome-wide association study (GWAS) of Chinese Han population.Objective Here we investigated their relationships of the susceptibility genes with disease subphenotypes, including renal nephritis, photosensitivity, ANA, age at diagnosis, malar rash, discoid rash, immunological disorder, oral ulcer, hematological disorder, neurological disorder, serositis, arithritis and vasculitis to further clarify the pathogenesis of systemic lupus erythematosus, and bring theoretical basis to develope new drugs.Methods We first performed case-only analyses (e.g. presence of malar rash versus no malar rash) to identify which subphenotypes were associated with the specific SNPs. Then we performed subphenotype-control analyses (e.g. presence of photosensitivity or negative of photosensitivity versus health controls) to examine the risk conferred by the SNPs on different subtypes of SLE. We correlated the presence of risk alleles with total number of ACR criteria, age at diagnosis and vasculitis of SLE. P values, odd ratios (ORs) and 95% confidence interval (CI) were estimated using SPSS13.0 software, and P values below 0.05 were considered to be statistically significant.Results In Phenotype case-only analyses identified that IRF5 (rs4728142) was no significantly different in all phenotypes(P>0.05), In subphenotype–control analyses show that significantly different between most subphenotypes and healthy controls, except for Serositis:SNP rs4728142 showed an association only in patients without Serositis(OR = 1.45,95% CI:1.35-1.56,P = 4.53E-23) but not in the presence of Serositis(OR = 1.21,95% CI: 1.00-1.48,P = 0.05).Conclusions The results suggest that the polymorphism of IRF5 gene has no associationwith the Clinical Features of SLE in ChineseHan population.