Hepatitis B reactivation in multiple myeloma patients with resolved hepatitis B undergoing chemotherapy

Background & Aims Despite increasing reports of hepatitis B virus (HBV) reactivation in multiple myeloma (MM), HBV reactivation in patients with resolved hepatitis B [hepatitis B surface antigen (HBsAg)‐negative/anti‐hepatitis B core antigen antibody (anti‐HBc)‐positive] is still poorly characterized. The aim of this study was to clarify its frequency and risk factors. Methods A total of 230 MM patients with resolved hepatitis B were retrospectively reviewed for HBV reactivation and biochemical flare. Results During a median 2.4 years of follow‐up, HBV reactivation was diagnosed in 12 patients (5.2%). The cumulative rates of HBV reactivation at 2 years and 5 years were 5% and 8% respectively. A baseline anti‐HBs‐negative status (P = 0.033) and high‐dose therapy/autologous stem‐cell transplantation [HDT/ASCT (P = 0.025)] were significant risk factors that were positively associated with HBV reactivation. In subgroup analysis of patients treated with HDT/ASCT (n = 127), a baseline anti‐HBs‐negative status was the only significant risk factor for HBV reactivation (hazard ratio, 4.64; 95% CI, 1.47–14.7; P = 0.009). Discussion These data show that evaluation of anti‐HBc is needed for MM patients, and suggest that monitoring of HBV DNA should be considered for patients with resolved hepatitis B undergoing HDT/ASCT, especially those who are anti‐HBs‐negative.