Tumour necrosis factor-α-857T allele reduces the risk of hepatitis B virus infection in an Asian population

. Tumour necrosis factor-a (TNF-a) plays a pivotal role in hepatitis B virus (HBV) clearance and host immune response determining the chronicity of HBV infection. However, studies of the association between TNF-a-857 polymorphism and chronic HBV infection have reported conflicting results. So a meta-analysis was carried out to draw a more precise conclusion. Pubmed (January, 1966March, 2011) and the China Biological Medicine Database (January, 1978March, 2011) were searched using the keywords TNF-a gene polymorphism in combination with HBV infection without language restriction. Fourteen studies including 4929 chronic HBV infection cases and 2702 controls describing the C857T genotype were included in the meta-analysis. All fourteen studies focussed on an Asian population. The overall meta-analysis suggested that TNF-a-857T allele reduced the risk of chronic HBV infection in the Asian population (OR = 0.82, 95% CI: 0.710.95, P = 0.008) when compared with a spontaneously recovered population. In the sensitivity analyses of the groups obeying HardyWeinberg equilibrium (HWE), without the largest study population and without the smallest study population, a similar association was revealed (OR = 0.81, 95% CI: 0.680.98, P = 0.043; OR = 0.77, 95% CI: 0.680.87, P = 0.0001; OR = 0.81, 95% CI: 0.700.95, P = 0.009, respectively). However, when compared with a healthy population, no significant association was found in the Asian population in all groups. So, we draw the conclusion that the TNF-a-857T allele reduces the risk of chronic HBV infection in this Asian population.