Hepatitis B surface antigen seroclearance in patients with chronic hepatitis B infection: A clinical study

Objective To investigate the clinical characteristics of hepatitis B surface antigen (HBsAg) seroclearance in patients with chronic hepatitis B virus (HBV) infection. Methods Patients with chronic HBV infection who achieved sustained virological response (SVR) within 6 years of ceasing formal antiviral treatment were assessed for HBsAg seroclearance (defined as loss of serum HBsAg on repeated testing for a period of >6 months), using enzyme immunoassays. Phase of HBV infection and liver function (serum alanine aminotransferase [ALT] and aspartate aminotransferase [AST] levels) and HBV DNA levels were also assessed. Results In total, 272 patients with chronic HBV and SVR were included; HBsAg seroclearance was achieved in 42 patients and not achieved in 230 patients. Serum HBsAg and ALT levels, ratios of HBsAg to HBV DNA and ratios of AST to ALT were significantly different between patients achieving, and not achieving, HBsAg seroclearance. The area under the receiver operating characteristic (ROC) curve of HBsAg levels for predicting the likelihood of HBsAg seroclearance was 0.85; the cut-off value was 203.86IU/ml. Conclusions These data demonstrate that HBsAg seroclearance was independently associated with host immunity, serum HBsAg level, serum ALT level, serum HBsAg to HBV DNA ratio and timing of drug therapy within the course of chronic HBV infection.