Reactivation of hepatitis B virus infection in patients with rheumatoid arthritis receiving tofacitinib

Objectives The aim of this study was to investigate hepatitis B virus (HBV) reactivation in patients with rheumatoid arthritis (RA) receiving tofacitinib. Method This was a retrospective study performed in a regional teaching hospital in southern Taiwan. During January 2017 and December 2020, patients with a clinician-confirmed diagnosis of RA using tofacitinib for at least 3 months were enrolled. Serum HBV DNA levels and serum alanine aminotransferase were followed up around every 3 to 6 months to assess HBV reactivation. Results A total of 98 patients with RA were enrolled, and eight were hepatitis B surface antigen positive (HBsAg+) (8.1%), 64 were HBsAg-negative (HBsAg-)/hepatitis B core antibody positive (HBcAb+) (65.3%). In the HBsAg+ patients, two patients received antiviral prophylaxis, and none of them had HBV reactivation or hepatitis flare-up. The HBV reactivation rate was 33.3% (2/6) in the HBsAg+ RA patient without antiviral prophylaxis. Among the HBsAg-/HBcAb+ patients, the HBV reactivation rate was 3.1% (2/64). The incidence rate of HBV reactivation was 153.8 per 1000 person-years for overall HBsAg+ patients and 250 per 1000 person-years after excluding patients receiving antiviral prophylaxis. The incidence rate was 11.2 per 1000 person-years for HBsAg-/HBcAb+ patients with RA receiving tofacitinib. Conclusion Tofacitinib could induce HBV reactivation in both HBsAg+ and HBsAg-/HBcAb+ RA patients. HBsAg+ patients receiving tofacitinib have a high incidence rate of HBV reactivation, which could be prevented by antiviral prophylaxis. Although the risk of reactivation is low in HBsAg-/HBcAb+ patients, closely monitoring HBV DNA and alanine aminotransferase should be suggested.