Hepatitis B surface antigen quantification at hepatitis B e antigen seroconversion predicts virological relapse after the cessation of entecavir treatment in hepatitis B e antigen-positive patients

Objectives: To assess off-treatment virological relapse rates and to determine the role of hepatitis B surface antigen (HBsAg) quantification in predicting virological relapse after stopping entecavir (ETV) treatment in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB). Methods: One hundred and twelve CHB patients for whom ETV was stopped in accordance with the Asian Pacific Association for the Study of the Liver guidelines stopping rules were enrolled. Patient HBsAg and HBV DNA levels were monitored every 4–12 weeks during ETV treatment and after ETV cessation. Post-treatment virological relapse was defined as a serum HBV DNA level of >10 000 copies/ml after stopping ETV treatment. Results: The virological relapse rate at 52 weeks after stopping ETV was 48.2%. The post-treatment virological relapse rate was significantly higher in patients aged >50 years than in those aged <50 years (p < 0.001), and the virological relapse rate was significantly lower in patients with an HBsAg level <2.0 log10 IU /ml than in those with a level ≥2.0 log10 IU /ml at ETV cessation (p = 0.005). An HBsAg level of 2.5 log10 IU/ml at HBeAg seroconversion was the optimal cut-off value for predicting post-treatment virological relapse (p < 0.001). In those aged <50 years and with HBsAg ≤2.5 log10 IU/ml at HBeAg seroconversion, the relapse rate was only 5%. In patients with HBsAg ≤2.5 log10 IU/ml at HBeAg seroconversion, 52.4% achieved HBsAg levels ≤2.0 log10 IU/ml at ETV cessation, while in those with HBsAg >2.5 log10 IU/ml at HBeAg seroconversion, only 4.4% achieved this criterion. Conclusions: HBsAg levels can help guide the timing of cessation of ETV treatment. HBsAg levels of 2.5 log10 IU/ml at HBeAg seroconversion may be a useful marker to predict virological relapse after the cessation of ETV treatment in HBeAg-positive CHB patients