Background: The efficacy of long-term hepatitis B virus (HBV) treatment with tenofovir (TDF) in relation to lamivudine (LMV) resistance in HIV patients failing on LMV deserves further investigations.
Methods: HIV-HBV coinfected patients were selected, provided that LMV was included in the first highly active antiretroviral therapy regimen and TDF was subsequently introduced.
Results: Forty HIV-HBV patients were included, 25 had undetectable HBV DNA on LMV and 15 were failing on LMV treatment. Three cases of triple 173V + 180M + 204V HBV reverse transcriptase (rt) mutants were identified, as well as several mutations or polymorphisms in the surface antigen gene at positions possibly correlating with vaccine escape. A new mutation (rtl233V) was found in one adefovir-naive patient. In 10 patients, uninterrupted TDF treatment led to a sustained treatment response for a median of 160 (interquartile range 111-189) weeks. Two patients underwent intermittent treatment with TDF and LMV, responding any time TDF was reintroduced. In one patient, TDF without LMV provided treatment response. One patient did not respond to TDF because of low treatment adherence. One patient infected with the triple rt mutant did not respond to entecavir, but TDF was successful as rescue.
Conclusions: Combination therapy with TDF was effective against HBV mutant viruses resistant to LMV and provided sustained control of HBV replication over long-term follow-up, even after entecavir failure. Moreover, suppression of HBV vaccine escape variants could provide important benefits from a public health perspective.