Association between interferon-gamma+874 T/A polymorphism and susceptibility to autoimmune diseases: a meta-analysis

Abstract

Objective The aim of this study was to explore whether the interferon (IFN)- +874 T/A polymorphism plays a role in modifying the risk of autoimmune diseases. Methods A meta-analysis was conducted on the association between the IFN- +874 T/A polymorphism and autoimmune diseases. Results Eighteen studies with a total of 2952 patients and 3832 controls were included in the meta-analysis. The meta-analysis revealed no association between autoimmune diseases and the IFN- +874 T allele in all study subjects (odds ratio (OR)=1.023, 95% confidence interval (CI)=0.894-1.171, p=0.738), but stratification by ethnicity indicated an association between the IFN- +874 T allele and autoimmune diseases in Latin American subjects (OR=0.780, 95% CI=0.629-0.953, p=0.015). Meta-analysis also revealed an association between autoimmune diseases and the IFN- +874 T/A polymorphism in Caucasian and Middle Eastern subjects under a dominant inheritance model (OR=0.686, 95% CI=0.489-0.964, p=0.003; OR=1.414, 95% CI=1.102-1.813, p=0.006). Meta-analysis by autoimmune disease type indicated an association between ITP and the IFN- +874 T allele (OR=1.753, 95% CI=1.228-2.503, p=0.002), but not for vasculitis, vitiligo, and auto-immune thyroid disease. Meta-analysis also showed a significant association between the IFN- +874 T/A polymorphism and systemic lupus erythematosus (SLE) under the dominant model (OR=1.668, 95% CI=1.114-2.497, p=0.013). Conclusions This meta-analysis indicates that the IFN- +874 T/A polymorphism may play a significant role in modifying the risk of autoimmune diseases in Caucasian, Latin American, and Middle Eastern subjects, and in particular shows that the IFN- +874 T/A polymorphism is associated with increased genetic susceptibility to idiopathic thrombocytopenic purpura and SLE.