Nationwide prospective and retrospective surveys for hepatitis B virus reactivation during immunosuppressive therapies

Background: The significance of HBV reactivation during immunosuppressive therapy was evaluated in three nationwide cohorts including patients with previously resolved HBV (prHBV) infection. Methods: The clinical features of 1061 patients with acute liver failure (ALF) or late-onset hepatic failure (LOHF) were retrospectively examined, focusing on those who experienced HBV reactivation. Additionally, 420 patients with prHBV infection were prospectively enrolled: 203 received immunosuppressive therapies immediately after enrollment, while the remaining 217 were enrolled after having received immunosuppressive therapies without the occurrence of HBV reactivation. The serum HBV-DNA levels were prospectively monitored every month, and the incidences of HBV reactivation, defined as a serum HBV-DNA level of 1.3 log IU/ml or more, were evaluated. Results: In the retrospective study, persistent HBV infection was found in 90 patients, and HBV reactivation was responsible for liver injuries in 50 patients including 23 receiving immunosuppressive therapies (26 with HBs-antigen positivity, 7 with prHBV infection). None of seven patients with prHBV infection were rescued. In the prospective studies, HBV reactivation occurred in ten patients, but preemptive entecavir administration prevented liver injury. The cumulative reactivation rate was 3.2 % at 6 months, and the increase of the rate compared to that at 6 months was +1.5 % at 48 months. Conclusions: HBV reactivation during immunosuppression was responsible for liver injuries in a quarter of the ALF/LOHF patients with persistent HBV infection. Early serum HBV-DNA monitoring may improve patient prognosis, since HBV reactivation typically occurs within 6 months of the start of immunosuppressive therapies in patients with prHBV infection.