Hepatitis B surface antigen levels after hepatitis B e-antigen seroclearance: a longitudinal follow-up study.

Abstract

The role of quantitative hepatitis B surface antigen (HBsAg) after hepatitis B e-antigen (HBeAg) seroclearance is not well defined. To determine the role of HBsAg levels in predicting significant viremia and hepatitis flares after HBeAg seroclearance. A total of 228 chronic hepatitis B patients with spontaneous HBeAg seroclearance were included. Patients were followed up regularly at 3-6 monthly intervals with routine liver biochemistry and hepatitis B serology. Levels of HBV DNA and HBsAg were measured at yearly intervals for up to 5 years after HBeAg seroclearance. The median log HBsAg and HBV DNA level after HBeAg seroclearance was 3.52 IU/ml and 4.13 IU/ ml respectively, with no significant correlation observed between them (P = 0.572). The HBV DNA at HBeAg seroclearance was 4.13 log IU/ml, compared with 3.12 log IU/ml after 5 years (P < 0.001). No significant change was observed for HBsAg levels (P = 0.991). Hepatitis B flares occurred in 76 (33.3%) patients. Patients who developed hepatitic flares compared with those without hepatitic flares were older (40 vs. 36 years, P = 0.001), had a higher HBV DNA at the time of HBeAg seroclearance (4.70 vs. 3.77 log IU/ml, P =< 0.001), and more likely to be males (42.7% vs. 23.4%, P = 0.002) respectively. There was no difference in HBsAg levels between those with and without hepatitis flare (3.54 vs. 3.52 log IU/ml respectively, P = 0.555). HBV DNA levels, but not HBsAg levels, after HBeAg seroclearance were associated with subsequent significant viremia and hepatitic flares. Male gender and older age was associated with significant viremia.