Lack of anti-HIV activity of entecavir in an HIV patient coinfected with hepatitis B and delta viruses

Approximately 5--10% of individuals with HIV infection suffer from chronic hepatitis B. For co-infected patients needing antiretroviral therapy, the combination of tenofovir plus emtricitabine is currently the preferred option. In contrast, for individuals with elevated CD4 cell counts and no need for antiretroviral therapy, pegylated interferon has been advised for hepatitis B e antigen-positive chronic hepatitis B. It is currently unclear what is the best option for hepatitis B e antigen-negative chronic hepatitis B when antiretroviral therapy is not needed. Concerns about the risk of selecting K65R in HIV, despite using only the approved anti-hepatitis B virus (HBV) dose of 10 mg per day adefovir, have precluded the open use of this drug in this population. As entecavir was thought to have potent and selective anti-HBV activity, it was considered the drug of choice for this subset of co-infected patients. A recent report has, however, challenged this view; a series of three patients who received entecavir without concomitant antiretroviral therapy showed a 1 log sub(10) decline in plasma HIV-RNA and emergence of the M184V mutation in one patient.