Tumor necrosis factor-α-308A allele may have a protective effect for chronic hepatitis B virus infection in Mongoloid populations

Forest plot of chronic hepatitis B virus infection risk associated with TNF-α-308G/A polymorphism for GA+AA vs. GG. For the −308A allele carriers (GA+AA), the pooled odds ratios indicated a significantly decreased risk of chronic hepatitis B (OR 0.70; 95% CI 0.55–0.89; p=0.004). In the subgroup analyses by ethnicity, significantly decreased risk was associated with −308 variant genotypes (GA and AA) in Mongoloid populations (OR 0.59; 95% CI 0.43–0.82; p=0.002). However, no significant associations were found in Caucasoids. OR: odds ratio; CI: confidence interval.

Begg's funnel plot (using odds ratio of chronic hepatitis B virus infection risk in GA+AA genotype when compared to GG genotype) of TNF-α-308G/A polymorphism and chronic hepatitis B virus infection risk for the genotype GA+AA vs. GG (p=0.300). The horizontal line represents the meta-analysis summary estimate, and the diagonal lines pseudo 95% confidence interval limits about the effect estimate. In the absence of publication bias, studies will be distributed symmetrically above and below the horizontal line. OR: odds ratio; CI: confidence interval.