Hôpital Henri-Mondor, Service d'hépatologie, Créteil, France
The natural history of chronic hepatitis B is complex. Three major phases are identified: 1) an immune tolerant phase with high HBV DNA and normal ALT levels associated with absent or mild liver lesions; 2) an immune active phase with high HBV DNA and elevated ALT levels associated with liver inflammation and fibrosis; 3) an inactive phase with low HBV DNA and normal ALT levels associated with mild liver inflammation. The primary adverse outcomes of chronic hepatitis B are cirrhosis and hepatocellular carcinoma that are mainly related to several factors including male gender, age, family history of hepatocellular carcinoma, HBV DNA above 2,000 IU/mL in subjects above 40, HBV genotype C, and basal core promoter mutation. Antiviral treatment must be discussed during the immune active phase in order to control HBV replication and to prevent adverse outcomes.