Association between the interferon‐ γ +874 T/A polymorphism and susceptibility to systemic lupus erythematosus and rheumatoid arthritis: A meta‐analysis

We aimed to determine whether the interferon (IFN) ‐γ +874 T/A polymorphism (rs2430561) is associated with susceptibility to systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). A meta‐analysis was conducted to assess the association between the IFN ‐γ +874 T/A polymorphism and SLE or RA using allele contrast, homozygous contrast, recessive, and dominant models. A total of nine studies (six on SLE and three on RA), involving 1839 patients and 2272 controls, were included in the meta‐analysis. The meta‐analysis revealed a significant association between SLE and the TT genotype of the IFN ‐γ +874 T/A polymorphism (odds ratio [OR] = 0.751, 95% confidence interval [CI] = 0.634–0.899, p  = .001), and stratification by ethnicity indicated an association between the IFN ‐γ +874 TT genotype and the Asian population. The analysis also revealed a significant association between SLE and the TT + TA genotype of the IFN ‐γ +874 T/A polymorphism in Arab populations (OR = 1.598, 95% CI = 1.053–2.425, p  = .028). However, no association between the IFN ‐γ +874 T/A polymorphism and RA was found using allele contrast, recessive, dominant or homozygous contrast models in all study subjects and ethnic groups. This meta‐analysis demonstrated that the IFN ‐γ +874 T/A polymorphism is associated with susceptibility to SLE in Asian and Arab populations.