Molecular analysis of hepatitis B virus (HBV) in an HIV co-infected patient with reactivation of occult HBV infection following discontinuation of lamivudine-including antiretroviral therapy

We report the case of an individual with human immunodeficiency virus (HIV) infection and anti-HBV core antibody positivity, who experienced severe HBV reactivation after discontinuation of lamivudine-including antiretroviral therapy (ART). HBV sequencing analysis showed a hepatitis B surface antigen escape mutant whose presence in an earlier sample excluded reinfection. Molecular sequencing showed some differences between two isolates collected at a 9-year interval, indicating HBV evolution. Resumption of ART containing an emtricitabine/tenofovir combination allowed control of plasma HBV DNA, which fell to undetectable levels.This case stresses the ability of HBV to evolve continuously, even during occult infection, and the effectiveness of ART in controlling OBI reactivation in HIV-infected individuals.Occult hepatitis B virus (HBV) infection (OBI) is, by definition, characterized by infectious HBV DNA in liver, blood, or both, in the absence of hepatitis B surface antigens (HBsAg) [1]. Isolated anti-HBV core antibodies (anti-HBc) have been shown to be a predictive marker of OBI [2]. Isolated anti-HBc [3,4] and OBI are often seen in patients with human immunodeficiency virus (HIV) infection [5,6], where they are more prevalent than in non-coinfected individuals [7]. Reactivation of chronic HBV in presence of HBsAg has been reported in immunosuppressed subjects and in those with HIV infection following discontinuation of antiretroviral therapy (ART) [8,9].There are few reports addressing OBI reactivation during HIV infection [10,11] and fewer still providing an extensive description of the molecular characteristics of occult HBV reactivation [12]. Nucleot(s)ide analogues (NA) lamivudine, emticitabine and tenofovir are known to be effective against both HIV and HBV, providing a unique opportunity to treat coinfected patients [13,14], but little information is available to establish whether resumption of ART for HIV/HBV coinfection may restore control of HBV replicat