OBJECTIVETo investigate the relationship between the method of administration of lamivudine and the therapeutic effect of the treatment in patients with chronic hepatitis B virus (HBV) infection.

METHODSOne hundred and seventy-nine patients were given lamivudine 100 mg daily for 1 to 3 years. The relationships of the therapeutic effect and the early response, YMDD mutants and duration of treatment were analyzed.

RESULTSAlanine aminotransferase normalization rate, the negativity rate of HBV DNA and HBeAg, and HBeAg sero-conversion all were increased gradually with prolonged treatment. At the end of 1 year, HBV DNA negativity rate (57.0%) reached its peak, HBeAg negativity rate (39.7%) and HBeAg sero-conversion rate (16.8%) were higher than those at the end of 3 months (chi2 = 28.489, 33.238, 12.690, P<0.01). The lower the HBV DNA level was at the end of 3 months, the higher the HBV DNA negativity and HBeAg sero-conversion rates were at the end of 52 weeks and at the end of the 6 months follow-up. When the duration of treatment reached 1 year and 1.5 years, HBV DNA rebound rate in the patients (40.0% and 40.0% respectively) with HBeAg sero-conversion was obviously less (chi2 = 12.424, 10.237, P<0.01) than in those without sero-conversion (88.2% and 85.0% respectively).

CONCLUSIONLamivudine therapy for HBV infection is safe and effective. The optimal duration of treatment was 1.5 years. The early responders had better therapeutic effects. HBV DNA positivity persisting at the end of 3 months medication or no HBeAg sero-conversion in 1 year predicts poor therapeutic effects.