Association Between Cytotoxic T-Lymphocyte-Associated Antigen 4 +49A/G Polymorphism and Persistent Hepatitis B Virus Infection in the Asian Population: Evidence from the Current Studies

Abstract

A number of studies assessed the association between cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) +49A/G polymorphism and persistent hepatitis B virus (HBV) infection risk. However, the results are quite contradictory. In order to obtain a more precise estimation of the relationship, a meta-analysis was performed. Pubmed, ISI Web of Knowledge, HuGE Navigator, Wanfang Database, and China National Knowledge Infrastructure were searched. Crude odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to estimate the strength of this association. Six publications were included in the final meta-analysis with 1075 cases and 1321 controls for CTLA-4 +49A/G polymorphism according to our inclusion and exclusion criteria. We observed that the CTLA-4 +49A/G polymorphism was significantly correlated with chronic HBV infection risk (the homozygote codominant model: OR 1.67, 95% CI 1.30-2.15; the dominant model: OR 1.34, 95% CI 1.01-1.78; the recessive model: OR 1.56, 95% CI 1.24-1.96; the allele contrast model: OR 1.32, 95% CI 1.10-1.59). No publication bias was observed in this study according to Begg's funnel plot and Egger's test. CTLA-4 +49A/G polymorphism is assumed to confer a higher risk for persistent HBV infection in the Asian population.