Effect of HIV co‐infection on mutation patterns of HBV in patients with lamivudine‐resistant chronic hepatitis B

A retrospective review was performed comparing lamivudine‐resistance mutation patterns between patients infected with hepatitis B virus (HBV) with or without human immunodeficiency virus (HIV) co‐infection. Medical records that included a genotypic test of patients infected with HBV and treated with lamivudine as the only anti‐HBV drug were reviewed. Pol gene mutations were assessed by direct sequencing of the reverse transcriptase fragment 125–213 aa. Eighty‐nine patients infected with HBV (29 co‐infected with HIV) with rtM204V or rtM204I mutations were included. Multiple mutations associated with the YMDD motif were observed in 33 (55%) of 60 patients infected with HBV only and in 28 (96.6%) of patients co‐infected with HIV/HBV. In this latter group, the prevalence of the rtV173L + rtL180M + rtM204V triple mutation was 31% versus a prevalence of 3.4% observed among patients infected with HBV only. All patients with the triple mutational pattern showed sE164D + sI195M changes in the envelope gene. Multivariate analysis demonstrated that HIV co‐infection (adjusted OR 11.2, 95% CI 2.0–61.0) and HBV genotype A (adjusted OR 7.2, 95% CI 1.5–34.8) were the only independent variables associated with the chance of harboring rtM204V. Patients with HBV genotype A or HIV co‐infection were more likely to harbor the rtM204V mutation. Patients co‐infected with HIV showed multiple mutations more frequently, including the triple mutation that may elicit a vaccine escape phenotype. Among patients co‐infected with HIV/HBV, strict HBV DNA monitoring is essential to detect treatment failure and adapt therapy to avoid limitations of future therapeutic options or the emergence of a public health threat. J. Med. Virol. 81:1151–1156, 2009. © 2009 Wiley‐Liss, Inc.