Short article: Safety of targeted prophylaxis strategy in patients with resolved hepatitis B virus infection receiving rituximab for immune-mediated diseases

Rituximab (RTX) is a monoclonal antibody that is widely used in hematologic malignancies and immune-mediated diseases (IMID) and has been associated with the risk of hepatitis B virus reactivation (HBVr). Thus, antiviral prophylaxis is recommended before RTX treatment in all patients with chronic hepatitis B virus (HBV) infection and those with resolved infection affected by onco-hematological conditions. By contrast, the correct management of HBsAg-negative/HbcAb-positive patients candidates for RTX-containing regimens for IMID is still debated, owing to few data currently available in this setting.We retrospectively evaluated the risk of HBVr in patients with IMID with resolved HBV infection, referred to the Infectious and Tropical Diseases Unit Outpatients Service, Careggi Hospital, Florence, Italy, between September 2013 and September 2017, undergoing RTX without antiviral prophylaxis and followed up by serial serum HBV-DNA monitoring.Overall, 20 patients with IMID were identified (70% female, with median age of 57 years) and followed up for a median period of 19 months (range: 2-36 months). A single HBVr case, detected in preclinical stage, was observed (1/20, 5%), and targeted prophylaxis was promptly introduced.The results supported the low to moderate risk of HBVr in HBsAg-negative/HBcAb-positive patients with IMID undergoing RTX, in contrast to what is observed in onco-hematological settings. The targeted prophylaxis strategy, based on serum HBV-DNA serial monitoring, seems a safe option in these patients.