Prevention of hepatitis B virus reactivation in patients receiving immunosuppressive therapy or chemotherapy.

With the increasing use of potent immunosuppressive therapy, reactivation of hepatitis B virus (HBV) in endemic regions is becoming a clinical problem requiring special attention. A recent annual nationwide survey clarified that HBV reactivation related to immunosuppressive therapy has been increasing in patients with malignant lymphoma, other hematological malignancies, oncological or rheumatological disease. In the survey, rituximab plus steroid-containing chemotherapy was identified as a risk factor for HBV reactivation in hepatitis B surface antigen (HBsAg) negative patients with malignant lymphoma. In this setting, HBV reactivation resulted in fatal fulminant hepatitis regardless of the treatment of nucleoside analog. The Intractable Hepatobiliary Disease Study Group and the Study Group for the Standardization of Treatment of Viral Hepatitis Including Cirrhosis jointly developed guidelines for preventing HBV reactivation. The essential features of the guideline are as follows. All patients should be screened for HBsAg by a sensitive method before the start of immunosuppressive therapy. Second, hepatitis B core antigen (HBcAb) and hepatitis B surface antibody (HBsAb) testing should be performed in HBsAg negative patients, especially those receiving intensive immunosuppressive therapy. Prophylaxis with nucleoside analogs is essential for preventing HBV reactivation in HBsAg positive patients. In contrast, HBsAg negative with HBcAb and/or HBsAb positive patients should be monitored monthly for an increase in serum HBV DNA during and 12 months after completion of chemotherapy. Nucleoside analogs should be administrated immediately when HBV DNA becomes positive during this period. This strategy facilitates commencement of nucleoside analogs at an early stage of HBV reactivation and results in prevention of severe hepatitis.