The association between three IL-6 polymorphisms and HBV-related liver diseases: a meta-analysis

Background: A quantity of case-control studies have been performed to address the association between the three interleukin-6 (IL-6) polymorphisms (-572G/C, -597G/A and -174G/C) and the risk of HBV related liver diseases. However, previous research results are inconsistent. We conducted this meta-analysis to clarify the correlation between these IL-6 polymorphisms and HBV related liver diseases. Methods: We searched in PubMed, EMBASE, Cochrane Library as well as Chinese databases including China National Knowledge Infrastructure (CNKI) and WanFang database for all the relevant studies up to April 15, 2015. The data were extracted by two independent authors. Odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated. Results: A total of 10 studies consisting of 3879 cases and 2812 controls were included in this metaanalysis. For IL-6 polymorphism -572G/C, an association with increased chronic hepatitis B (CHB) risk was observed under in allelic, homozygous, heterozygous, dominant and recessive model. However, IL-6 polymorphisms (-572G/C) were not related to Inactive Carrier (IC), Liver Cirrhosis (LC) and Hepatocellular Carcinoma (HCC) risk in this study. We also found that IL-6 polymorphisms (-597G/A) were related to CHB in allelic, heterozygous, recessive model. For IL-6 polymorphism -174G/C, we did not find any association with CHB risk. Conclusion: The present meta-analysis indicated that IL-6 polymorphisms -572G/C and -597G/A significantly associate with CHB risk, but might not be significantly related to the progressive HBV such as LC and HCC. IL-6 polymorphisms -174G/C might not significantly associate with HBV related liver diseases.