A review of the natural history of chronic hepatitis B in the era of transient elastography.

Understanding the natural history of chronic hepatitis B is important in order to predict the prognosis, to stratify the risk of hepatocellular carcinoma and to select appropriate candidates for antiviral treatment. Liver fibrosis is the pathogenic process that leads to liver cirrhosis. The study of liver fibrosis in the past has largely been hampered by the invasive nature of a liver biopsy. Most liver biopsy series represent biased populations with more active disease. Transient elastography is a reliable and non-invasive measurement of liver fibrosis that allows the study of liver fibrosis among patients without clinical indication for liver biopsy. Large studies using transient elastography in patients with predominantly normal alanine aminotransferase levels have been reported recently. The different roles of patient age, hepatitis B virus DNA and alanine aminotransferase levels in the risk stratification for advanced liver fibrosis have been defined in hepatitis B e antigen-positive and hepatitis B e antigen-negative chronic hepatitis B patients. The relationship between metabolic syndrome and chronic hepatitis B is also explored. In this review, new insights from studies using transient elastography on the natural history of chronic hepatitis B with special focus on liver fibrosis will be summarized and discussed.