Interferon Gamma+874t/A Polymorphism Increases The Risk Of Hepatitis Virus-Related Diseases: Evidence From A Meta-Analysis

BackgroundInterferon gamma (IFN-gamma) is a key regulatory cytokine, which plays an important role in antiviral defense of an infected host. However, the association between the IFN-gamma + 874T/A gene polymorphism and hepatitis virus-related diseases is heterogeneous.MethodsBased on the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement, a comprehensive literature search of eligible studies in Embase, Pubmed, and the Cochrane Library was undertaken through November 2014. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were used to measure the strength of the models.ResultsSeventeen case-control articles, including 24 studies with 5503 individuals, met the inclusion criteria. The results indicated a statistically significant association between the IFN-gamma + 874T/A polymorphism and hepatitis virus-related diseases in a recessive gene model (AA vs. TT+TA: OR=1.350, 95% CI=1.101-1.657, P=0.004, I-2%=54.3, and P-Q=0.001 for heterogeneity), especially in Asians (OR=1.407, 95% CI=1.035-1.911, P=0.029, I-2%=61.9, and P-Q=0.005 for heterogeneity) and hepatitis B virus (HBV)-related disease (OR=1.486, 95% CI=1.195-1.849, P=0.000, I-2%=40.4, and P-Q=0.053 for heterogeneity).ConclusionsThe evidence suggests that the IFN-gamma + 874T/A polymorphism increases the risk of hepatitis virus-related diseases, especially in Asians and HBV-related diseases. Further studies on this topic in different ethnicities, especially genome-wide association studies, should be conducted to strengthen our results.