Factorial Analysis of Hepatitis B Virus Reactivation-Induced Hepatitis B Using JADER

Hepatitis B caused by chemotherapy- and immunosuppression-associated hepatitis B virus reactivation is likely to become fulminant, and a high mortality rate has been reported. In this study, using the Japanese adverse drug event report database (JADER), factorial analysis of patients who developed hepatitis B as an adverse event was performed. The number of reported cases of hepatitis B during the survey period was 781 and 185 of them (24%) died. Rituximab and prednisolone were administered to many cases (233, 216 cases, respectively), and the reporting odds ratios were high (65.35, 13.40, respectively), suggesting their strong association with the development of hepatitis B. Regarding the onset time, rituximab-induced hepatitis B developed within one year after administration in 83%, being a high frequency. Prednisolone-induced hepatitis B developed even after one year in 36%. Since prednisolone is used to treat rheumatoid arthritis at a dose ≤10 mg/d, the patients were divided based on the prednisolone dose into the groups treated at >10 and ≤10 mg/d, and the onset time was investigated in each group. The median onset time was 113 and 330 d, respectively, showing a significant difference. On time-to-event analysis using the Weibull distribution, rituximab was classified as the early failure type, and prednisolone and methotrexate for rheumatoid arthritis were classified as the wear out failure type. These findings are important information which may lead to early discovery of and taking actions against hepatitis B being helpful for providing appropriate medical care.