Prediction of off-treatment response to lamivudine by serum hepatitis B surface antigen quantification in hepatitis B e antigen-negative patients

Background: The timing of antiviral therapy cessation in hepatitis B e antigen (HBeAg)-negative patients is controversial. Here, we aimed to investigate the role of HBV DNA and hepatitis B surface antigen (HBsAg) monitoring to predict off-treatment sustained response. Methods: A total of 53 HBeAg-negative chronic hepatitis B patients who received lamivudine for 34 23 (range 12-76) months and had lamivudine stopped for 47 35 months were studied. Primary outcome was sustained response, defined as HBV DNA <= 200 IU/ml, at 12 months post-treatment (SR-12). Results: A total of 9 (1 no) patients achieved SR-12. HBV DNA at baseline, month 6 and end of treatment had no association with SR-12. HBsAg levels tended to decrease more significantly during treatment among SR-12 responders. At the end of treatment, both HBsAg <= 2 log IU/ml and reduction by >1 log from baseline had sensitivity, specificity, positive and negative predictive values for SR-12 of 78%, 96%, 78% and 96%, respectively. All 5 patients with HBsAg <= 2 log IU/ml and reduction >1 log at the end of treatment achieved SR-12 and all 40 patients with HBsAg>2 log IU/ml and reduction <= 1 log did not have SR-12. The cumulative probability of sustained response and HBsAg clearance at 5 years among patients with HBsAg <= 2 log IU/ml were 88% and 72%, respectively, that among patients with HBsAg reduction >1 log were 74% and 61%, respectively. Conclusions: Monitoring of HBsAg level can guide the timing of stopping lamivudine in HBeAg-negative chronic hepatitis B.