The +874T/A polymorphism in the interferon-γ gene and tuberculosis risk: An update by meta-analysis

The +874T/A polymorphism in the interferon-gamma (IFN-gamma) gene has been extensively examined for association to tuberculosis (TB); however, results of different studies have been inconsistent. The aim of this study was to comprehensively analyze the genetic risk of the +874T/A polymorphism in IFN-gamma gene for TB by meta-analysis. A total of 4553 cases and 4631 controls in 21 case-control studies were included in this meta-analysis. The results indicated that the variant T allele carriers had a 27% decreased risk of TB, when compared with the homozygote AA (odds ratio [OR] = 0.73, 95% confidence interval [CI] = 0.61-0.87 for TT + TA versus AA). In the subgroup analysis by ethnicity, significant decreased risks were associated with T allele carriers in Asians (OR = 0.71, 95% CI 0.52-0.97, p = 0.03) but not in Caucasians (OR = 0.87, 95% Cl = 0.65-1.17, p = 0.37). Our results suggest that the IFN-gamma +874T/A polymorphism contributes to susceptibility to TB. (C) 2011 Published by Elsevier Inc. on behalf of American Society for Histocompatibility and Immunogenetics.