Objective: To investigate the factors which may affect the rate of HBeAg seroconversion and its durability after long-term lamivudine therapy in chronic hepatitis B patients.
Methods: 81 patients were treated in a phase III clinical trial with lamivudine 100 mg daily for up to 5 years. The mean period of treatment was (48.84+/-10.52) months (range: 16 approximately 60 months). When HBeAg seroconversion occurred in the patients, which was defined as loss of HBeAg and detection of anti-HBe antibody, HBV DNA level less than 10 mEq/ml more than two times (once every 3 months), the lamivudine treatment was stopped and they were followed-up for another 6 approximately 12 months. The HBV DNA level was detected using Branched DNA assay (Chiron). The HBV markers were detected using IMX assay (Abbott). HBV genotyping was performed using type-specific PCR. The data were analyzed using logistic multivariant analysis.
Results: (1) The distribution of HBV genotypes was as follows: type B, 17 (20.97%), type C, 62 (76.54%), and type B+C, 2 (2.47%). (2) 26 patients achieved HBeAg seroconversion (32.10%). The annual seroconversion rates were 16.05% (13/81) in the 1st year, 19.75% (16/81) in the 2nd, 27.16 % (22/81) in the 3rd, 28.40% (23/81) in the 4th and 32.10% (26/81) in the 5th year. Four patients had a reappearance of HBeAg and an elevation of HBV DNA. Therefore the stability ratio was 84.62% (22/26). The mean baseline ALT and HBV DNA levels in those who were seroconvered were (104.8+/-86.3) U/L and (940.1+/-1123.7) mEq/ml, respectively. Mean baseline ALT and HBV DNA of non-seroconverters were (48.3+/-46.9) U/L and (2152.3+/-3063.5) mEq/ml. There was a significant difference between the two groups shown by Kruskal-Wallis Test (P < 0.05). Analysis by logistic multivariate analysis showed that the rate of HBeAg seroconversion and its durability rate correlated with a high baseline ALT. In contrast, a relatively low seroconversion rate and durability rate was observed in patients with high baseline HBV DNA. The durability rate also correlated with additional lamivudine treatment after HBeAg seroconversion.
Conclusion: Continuation of lamivudine therapy for more than 6 months after HBeAg seroconversion might increase the durability of response.