Drug-resistant genes at hepatitis B virus polymerase region during entecavir treatment / 中国医学科学院学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the drug-resistant genes at hepatitis B virus (HBV) polymerase region during entecavir (ETV) treatment.</p><p><b>METHODS</b>Serum samples from chronic hepatitis B patients with virologic breakthrough during enticavir therapy were studied. The resistant mutation patterns in the polymerase gene of hepatitis B virus were analyzed using the polymerase chain reaction (PCR)-sequencing method.</p><p><b>RESULTS</b>ETV resistance was detected from 19 out of 29 ETV-refractory patients, among whom 16 (84.2%) had a history of lamivudine-refractory. The mutation patterns were diverse, while rtL180 + rtM204 + rtT184 (58.6%, 17/29) was most common in patients with ETV genotype resistance. Four of 7 patients (7/29, 24.1%) with genotype B were detected to have ETV genotype resistance, while 15 of 22 patients (22/29, 75.9%) with genotype C were detected to have ETV genotype resistance. The rate of ETV genotype resistance was 57.1% (4/7) and 68.2% (15/22) in patients with genotype B and genotype C,while no statistical difference was found(P = 0.665).</p><p><b>CONCLUSIONS</b>ETV genotype resistance is more common in patients who have been refractory to ETV and lamivudine sequential treatment. rtM204+rtL180+rtT184 mutation is common in genotype B and C ETV resistance patients.</p>