The Biology and Genetic Variation of Hepatitis B Virus

Hepatitis B virus (HBV) infection is the main cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC). Several factors such as serum HBV DNA level, genotype and specific viral mutations have been clarified to determine disease progression of chronic hepatitis B. Among these, mutations can also occur in chronic HBV patients with antiviral treatment such as lamivudine therapy. A better understanding of the host and viral mechanisms that influence the course of HBV infection and drug resistance to effective therapeutic approaches will improve the organization of patients with chronic HBV infection to attain viral eradication. This study aims to review the molecular biology of HBV, as well as the natural and induced genetic variations in response to anti-viral therapy in humans. The effect of host genetic factors in the outcome of HBV infection and new strategies for antiviral therapy are addressed.