Published online Jun 28, 2014. doi: 10.3748/wjg.v20.i24.7696
Revised: January 10, 2014
Accepted: March 7, 2014
Published online: June 28, 2014
Persistent hepatitis B virus (HBV) infection is a significant public health problem because it is a major cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC). Roughly one-third of the world population has been infected with HBV and there are about 350 million (5%-6%) persistent carriers. HBV causes 80% of all liver cancer cases and is the second most important carcinogen, after smoking tobacco. There is an approximate 90% risk of becoming a persistent carrier following perinatal infection in infants born to e antigen positive carrier mothers and a 30% risk in pre-school children. Only 5%-10% of adults become persistent carriers following infection. Of individuals persistently infected with HBV, 10%-30% will develop liver cirrhosis and HCC. These highly variable outcomes in both clearance rates and disease outcomes in persistently infected individuals cannot be fully explained by differences in immunological, viral or environmental factors. Thus, differences in host genetic factors may affect the natural history of hepatitis B.
Core tip: This manuscript is a review and summary of the advances about human genetic polymorphisms that are associated with hepatitis B virus (HBV) clearance and persistent infection. Especially, large sample size candidate gene association studies and genome-wide association studies, which discovered several gene polymorphisms that are associated with HBV clearance, such as HLA-DPA1 and HLA-DPB1 polymorphisms, are focused.