[Lamivudine-resistant analysis and management for chronic hepatitis B patients with initial lamivudine therapy].

Objective: To study the factors influencing the long-term usage of lamivudine (LAM) in chronic hepatitis B (CHB) patients and the management after drug-resistance.

Methods: 383 cases of naive CHB patients in our outpatient clinic were treated with lamivudine (100 mg/d) and followed up for at least over 1 year from 2001 to 2010. 129 cases encountered lamivudine-resistance and were then divided into two groups: patients in group A were switched to adefovir dipivoxil (ADV) alternative treatment and those patients in group B were added with ADV for continuous treatment. Efficacy assessment factors included serum HBV markers, HBV DNA, ALT, AFP and other biochemical indicators.

Results: Among the 383 cases, patients with HBV DNA negative conversion (PCR below test line) at 3 months, 6 months, 1 year, 2 years, 3 years and > 3 years after initial treatment were respectively 156 cases (40.7%), 213 cases (55.6%), 228 cases (59.5% ), 217cases (56.7%), 214 cases (55.9%) and 213 cases (55.6%). HBeAg/HBeAb seroconversion occurred in 62 cases (22.6%). 12 cases were found with primary LAM resistance, 129 cases with HBV breakthrough and rebound, the cumulative resistance rate was 36.8% and the cumulative rebound rate was 34.8%. High baseline viral load, baseline ALT levels < 2 ULN, Lower virologic response rate at week 24 were associated with a higher rebound rate (chi2 is 35.716, 8.728, 43.534, respectively, all with P < 0.01).Viral breakthrough and rebound occurred in 112 patients (86.8%) within 1 year and a half, 123 patients (95.3%) occurred at the end of 2 years and no patient with viral breakthrough and rebound after 5 years. For the patients with viral rebound in group A and group B, the rates of HBV DNA loss were 22.7% (15/66) and 58.7% (37/63) respectively, and the viral response rates were 59.1% (39/66) and 87.3% (52/63) respectively, with chi2 values equaled 17.364 and 12.975 respectively (P < 0.01).

Conclusion: For the chronic hepatitis B patients on initial treatment with lamivudine, the viral rebound occurred mainly within 2 years. LAM combined with ADV is more effective than ADV alone for lamivudine-resistant patients.