Molecular characterization of occult and overt hepatitis B (HBV) infection in an HIV-infected person with reactivation of HBV after antiretroviral treatment interruption.

INTRODUCTION: Occult HBV infection is characterized by the absence of surface antigenemia and the presence of potentially infectious hepatitis B virus (HBV)-DNA present in liver, serum, or both. Reactivation of chronic HBV infection in the presence of the HBV surface antigen (HBsAg) is a well-known complication in immunocompromised individuals under cytotoxic chemotherapy or in HIV-infected individuals when nucleos(t)ide analogs effective against HIV/HBV are discontinued. However, little is known on the possibility of such a complication in HIV-infected persons with HBV-core antibody (anti-HBc) as the sole serological marker of past HBV infection. CASE
PRESENTATION: Here we report the case of one HIV-infected, anti-HBc-positive individual who showed a severe reactivation of HBV after the interruption of antiretroviral therapy (ART).
RESULTS: Analysis of the plasma samples revealed HBV-DNaemia, albeit at very low levels in the latent phase, while the HBV-DNA level was highly increased during the overt phase that corresponded to the period of ART interruption, decreasing dramatically after the subsequent introduction of tenofovir-based ART. Molecular analysis of HBV in the two phases showed that overt HBV infection was due to reactivation of the occult HBV rather than to reinfection.
CONCLUSIONS: Our case underlines the possibility that occult HBV infection may still have the potential to be severely reactivated in HIV-infected individuals, particularly when antiretroviral treatment is discontinued.