Background and objective: Management of chronic hepatitis B is a global public health challenge. There are several updated guidelines proposed based on treatment outcome data from the respective study populations. In this study, we aim to characterize the antiviral resistance mutations to lamivudine monotherapy in patients diagnosed with chronic hepatitis B from the Indian subcontinent.
Methods: A total of 147 lamivudine-treated patients with a median treatment duration of 13 (interquartile range 8-24) months were studied. Virological response was measured by hepatitis B virus (HBV) DNA levels. Antiviral resistance mutations were identified by sequencing HBV reverse transcriptase domains. Factors associated with virological response and antiviral resistance mutations were analyzed.
Results: Virological response was observed in 50 (35 %) patients while 84 (57 %) were non-responders. The virological response for the remaining 13 (9 %) patients was undetermined. Forty patients (27 %) developed lamivudine-resistant mutations. HBV genotypes, subgenotypes and hepatitis B surface antigen subtypes did not show significant association with virological response or lamivudine-resistant mutations. High HBV DNA levels and increased treatment duration were strongly associated with the development of lamivudine-resistant mutations (p = 0.002 and p < 0.001). Patients who continued to be positive for hepatitis B e antigen have an increased risk for treatment failure (p = 0.010). High baseline aspartate transaminase levels were significantly associated with subsequent lamivudine response (p = 0.037).
Conclusion: Considering the limited potency and high resistance rates to lamivudine therapy, our study emphasizes the use of more potent drugs in the management of chronic hepatitis B in the Indian subcontinent.