[Reactivation of hepatitis B associated with immunosuppression].

The hepatitis B virus is an important cause of viral reactivation and flares in immunosuppressed patients. Factors associated with viral reactivation include positive HBs antigen, rituximab treatment, onco-haematological pathology and bone marrow transplantation. In situations at high risk of viral reactivation prophylactic antiviral therapy is indicated and reduces morbidity and mortality related to viral hepatitis flares.