Hepatitis B virus reactivation in B-cell lymphoma patients treated with rituximab: analysis from the Asia Lymphoma Study Group.

Background: Hepatitis B virus (HBV) reactivation is increasing, as rituximab has become widely used for B-cell lymphoma. Thus, prevention and management of HBV reactivation are important in HBV-endemic areas.

Methods: Hepatitis B virus (HBV) reactivation in HBV surface antigen (HBsAg)-positive patients and HBsAg-negative/HBV core antibody (HBcAb)-positive patients who received rituximab-containing chemotherapy was investigated by the Asia Lymphoma Study Group via retrospective (n=340), and the results were compared to cross-sectional analysis with patients who were prospectively monitored in a single institute (n=127). The goal of the study was to define the frequency of HBV reactivation and the efficacy of antiviral prophylaxis.

Results: HBV reactivation was found in 27.8% of HBsAg-positive patients (45/162) in the retrospective analysis, being significantly less frequent in patients receiving antiviral prophylaxis than those not (22.9%, 32/140 versus 59.1%, 13/22; p<0.001). Lamivudine was most commonly used (96/162, 59.3%), but more than 20% of HBsAg-positive patients showed breakthrough HBV reactivation. In the cross-sectional analysis, a reduced rate of HBV reactivation occurred for entecavir as compared with lamivudine prophylaxis (6.3% versus 39.3%; p<0.05). HBV DNA monitoring of HBsAg-negative/HBcAb-positive patients in the cross-sectional analysis showed HBV reactivation in only 2.4% of cases.

Conclusions: This is the largest study of HBV reactivation in patients receiving rituximab-containing chemotherapy to date, and we defined the probability of HBV reactivation in an HBV-endemic region.