Detection of Hepatitis B Virus Drug Resistance Mutations by Pyrosequencing Method

Abstract

Introduction: The development of drug resistance mutations to nucleos(t)ide analogues during long-term therapy for chronic hepatitis B virus (HBV) infection is a major problem that may lead to treatment failure. The aim of this study was to investigate the HBV drug resistance gene mutations in patients with chronic HBV infection by pyrosequencing method. Materials and Methods: Between December 2013 and May 2014, serum samples collected from 137 patients with chronic HBV infection, (89 treatment-naive and 48 treatment-experienced), were analyzed with real-time polymerase chain reaction analysis followed by pyrosequencing (PyroStar HBV Drug Resistance Test, Altona Diagnostics, Germany) for drug resistance mutations associated with lamivudine (LAM), adefovir, telbivudine (TEL), entecavir (ETV), and tenofovir (TDF). Results: Of the 89 treatment-naive patients, one (1.1%) had the rtA194T mutation, associated with reduced susceptibility to TDF. Of the 48 treatment-experienced patients, one (2.1%) had the rtM204I mutation, associated with drug resistance to LAM, TEL, and cross-resistance to ETV. Compensatory mutation rtL180M was observed in two patients (4.2%). The presence of rtM204V combined with rtT184S mutation indicating ETV resistance was detected in one patient (2.1%). Conclusion: The incidence of drug resistance mutations was 8.3% in treatment-experienced and 1.1% in treatment-naive patients. The use of pyrosequencing technology before and during treatment of patients with chronic HBV infection would contribute to the rapid detection of drug resistance mutations.

Keywords

• Lamivudine
• entecavir
• tenofovir
• drug resistance mutations
• pyrosequencing method