Clinical implications of the titer of serum hepatitis B surface antigen during the natural history of hepatitis B virus infection

Although there are some differences in hepatitis B surface antigen (HBsAg) titers in infection with different hepatitis B virus (HBV) genotypes, the HBsAg titers for each HBV genotype have not been evaluated extensively. The aim of this study was to investigate HBsAg titers during the natural history of patients infected with HBV in Korea, where the HBV genotype C is endemic exclusively. Four hundred fifteen patients were enrolled retrospectively and classified according to definitions of the natural phases of HBV infection. In total, 73, 118, 147, and 77 patients were classified in the immune tolerance, immune clearance, low replicative, and HBeAg-negative hepatitis phases, respectively. HBsAg titers (4.35 ± 0.67, 3.74 ± 0.68, 2.39 ± 1.23, and 3.29 ± 0.64 log10 IU/ml) were significantly different in the immune tolerance, immune clearance, low replicative, and HBeAg-negative hepatitis phases, respectively (P