Clinical characteristics and molecular analysis of hepatitis B virus reactivation in hepatitis B surface antigen-negative patients during or after immunosuppressive or cytotoxic chemotherapy

Background and aim: Reactivation of hepatitis B virus (HBV) in hepatitis B surface antigen (HBsAg)-positive patients treated with immunosuppressive or cytotoxic chemotherapy is well known and has emerged as an important clinical issue. The risk is low, but reactivation of HBV in HBsAg-negative patients after resolution of HBV infection also occurs; however, the clinical and virological characteristics remain somewhat unclear. We investigated HBsAg-negative patients who developed HBV reactivation during or after immunosuppressive or cytotoxic chemotherapy to clarify the clinical and virological features. Methods: Reactivation of HBV in 30 previously infected that is HBsAg-negative patients during or after immunosuppressive or cytotoxic chemotherapy was examined. Direct sequencing at the time of reactivation was used to evaluate 11 patients. Results: The majority of patients had diffuse large B cell lymphoma treated by rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisolone. Fulminant hepatic failure developed in three patients, who did not survive. HBV subgenotypes A2/Ae (n = 1), B1/Bj (n = 2), and C2/Ce (n = 8) were detected. There were no significant differences in the prevalence of BCP/PC variants between HBV reactivation and acute self-limited hepatitis patient groups. BCP and PC variants were not associated with development of fulminant hepatic failure from HBV reactivation. The prevalence of HBV S region variants, including immune-escape mutants, among reactivation patients was significantly higher than that in acute self-limited hepatitis patients. Conclusions: Reactivation risk factors included male sex, advanced age, and hematological malignancy. HBV S gene immune-escape mutants were frequently found in the HBsAg-negative reactivation patients during or after immunosuppressive or cytotoxic chemotherapy.