Abstract
Serum hepatitis B surface antigen (HBsAg) quantification can reflect the level of HBV replication and can be used as a surrogate maker for the evaluation of infected cells. Recent studies have shown that HBsAg quantification can help to distinguish the nature history of chronic hepatitis B and predict spontaneous clearance of HBsAg and the risk of progressive liver diseases. The dynamic change in HBsAg helps to predict the therapeutic effects of interferon and nucleoside analogues and sustained virologic response, guide withdrawal, and improve and optimize the therapeutic strategy for chronic hepatitis B in clinical practice. These issues have become the hot topics in recent years. However, the cut-off values of HBsAg level in patient management and various therapeutic strategies have not been determined. This article reviews the research advances in the significance of HBsAg quantification in the natural history and optimized treatment of chronic hepatitis B.