RESUMO
OBJECTIVES: Tenofovir disoproxil fumarate (TDF) is active against hepatitis B virus (HBV) and HIV. However, the long-term efficacy of tenofovir disoproxil fumarate (TDF) is not well known and the appearance of resistance is a major concern. We have studied the efficacy of TDF against HBV in patients treated at an Infectious Diseases Unit. METHODS: We carried out a retrospective observational study of the efficacy of TDF against HBV replication in a cohort of 52 HIV-coinfected patients who received TDF for at least 6 months. RESULTS: The median duration of follow-up of TDF treatment was 34 months. Forty-one patients (79%) were positive for HBV envelope antigen (HBeAg) and 35 had received previous lamivudine monotherapy for a median duration of 32 months. Virological breakthrough was observed in nine cases (17%). At the end of the follow-up period, HBV DNA levels were <1000 copies/mL in 42 patients (81%) and <200 copies/mL in 31 patients (60%). There were no significant differences between the lamivudine-naïve and lamivudine-experienced groups. In the lamivudine-experienced group, the duration of previous lamivudine monotherapy was associated with failure to achieve HBV DNA levels <200 copies/mL (P=0.036). Adding lamivudine or emtricitabine to TDF did not improve virological suppression. In 39 patients who achieved <200 HBV DNA copies/mL during TDF treatment, virological breakthrough was seen only in two patients (5%) after a median follow-up duration of 39.7 months. CONCLUSIONS: TDF was able to control HBV replication in most HIV-coinfected patients after a median follow-up duration of 34 months, regardless of previous lamivudine treatment. However, a sizeable proportion of patients developed virological breakthrough.
