Association between the interferon regulatory factor 5 rs2004640 functional polymorphism and systemic lupus erythematosus: an updated meta-analysis

Objective: The aim of this study is to determine whether the functional interferon regulatory factor 5 (IRF5) polymorphism rs2004640 is associated with susceptibility to systemic lupus erythematosus (SLE) in multiple ethnic populations. Methods: A meta-analysis was conducted on the T allele of the IRF5 rs2004640 polymorphism in all study participants as well as each ethnic population. Results: Twenty research articles that included 28 comparative studies of 20,892 patients and 24,930 controls were included in the meta-analysis. The Asian population had a much lower prevalence of the T allele than any other study population at 28%, and the European population had the highest prevalence of the T allele at 52%. Meta-analysis showed an association between the IRF5 rs2004640 polymorphism and SLE in all participants (odds ratio = 1.472, 95% confidence interval = 1.370–1.582, p < 0.001). Analysis after stratification by ethnicity indicated that the IRF5 rs2004640 T allele is significantly associated with SLE in Europeans, Asians, Latin Americans and Arabs. Conclusions: This meta-analysis confirms that the IRF5 rs2004640 polymorphism is associated with SLE susceptibility in different ethnic groups, and that its prevalence is ethnicity dependent.