Risk of Hepatitis B Reactivation in Patients with Past Hepatitis B Virus Infection Undergoing Biologic and Targeted Therapies for Rheumatic Diseases

Studies from Asian and European countries have demonstrated a low risk of hepatitis B virus (HBV) reactivation in patients with past hepatitis B infection (HBsAg −ve, anti-HBc [Formula: see text]ve) and rheumatic diseases receiving biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs). However, data regarding Chinese patients in Hong Kong is not available. Objective: The current study was performed to report the risk of HBV reactivation in Chinese patients with past hepatitis B infection and rheumatic diseases receiving b/tsDMARDs. Method: Clinical records of patients with various rheumatic diseases receiving b/tsDMARDs between 2004 and 2018 in two public hospitals in Hong Kong were retrieved. Patients with past hepatitis B infection (HBsAg −ve, anti-HBc [Formula: see text]ve) were included for analysis. Those with baseline detectable HBV DNA were excluded. HBV reactivation was defined as either the occurrence of HBV DNA from a baseline undetectable level or reverse HBsAg seroconversion. The incidence of HBV reactivation was reported, and risk factors for HBV reactivation were studied using Cox regression. Results: A total of 180 patients with rheumatic diseases, including rheumatoid arthritis (63.3%), spondyloarthritis (30%), and systemic lupus erythematosus (3.9%), were studied. Nine patients (5%) developed HBV reactivation during a median follow-up of 14.5 months (incidence 2.76 per 100 person-years). Twenty-six (14.4%) patients were put on preemptive antiviral treatment at baseline, and none developed reactivation. Among those who had an increase in HBV DNA titers, none developed overt hepatitis or liver failure. HBV-DNA titers returned to undetectable levels after antiviral treatment in four patients (44.4%) and did not further increase in the remaining five patients (55.6%) who did not receive antiviral treatment. Conclusion: The risk of HBV reactivation was low (5%) among Chinese patients in Hong Kong with past hepatitis B infection and receiving b/tsDMARDs for various rheumatic diseases. None of the HBV reactivation cases resulted in clinical hepatitis, and HBV DNA titers dropped with antiviral therapy.