Individual prediction model for lamivudine treatment response in hepatitis B virus e antigen-positive chronic hepatitis B patients

Background and Aims: Although prolonged lamivudine (LAM) therapy is associated with the emergence of LAM-resistant mutations, it is still a commonly used therapy in many Asian countries because of its established long-term safety and low cost. The aim of our study was to assess the predictors of long-term LAM treatment response and to establish an individual prediction model (IPM) for hepatitis B virus e antigen (HBeAg) seroconversion in HBeAg-positive chronic hepatitis B (CHB) patients. Methods: This was a multicenter analysis of 838 patients treated with LAM between January 1999 and August 2004. Of these, 748 patients were followed up for at least 24 months. Results: The median age was 43.0 years (range, 19-79 years) and the mean duration of LAM monotherapy was 34.2±0.7 months. In the multivariate analysis, age (odds ratio [OR]=0.974, P<0.001), baseline alanine aminotransferase level (OR=1.001, P=0.014), and baseline hepatitis B virus DNA level (OR=0.749, P<0.001) were independent factors for HBeAg seroconversion. Based on the predictors, an IPM was established. Patients were classified into high (>50%), intermediate (30-50%), or low (≤30%) response groups based on their probability of HBeAg seroconversion according to the IPM. The cumulative HBeAg seroconversion rate at 6 years for the high, intermediate, and low response groups was 66.0%, 48.5%, and 21.8%, respectively (P<0.001). Conclusions: An IPM was developed based on predictors of HBeAg seroconversion in HBeAg-positive CHB patients on LAM monotherapy. This model will allow screening of LAM responders prior to the commencement of antiviral treatment.