The Impact of b/tsDMARD Dose Reduction on Chronic Hepatitis B in Rheumatoid Arthritis Patients: A Two-Center Long-Term Safety Analysis

Background: We aimed to investigate the change of hepatitis B virus (HBV) viral loads and HBV reactivation (HBVr) in rheumatoid arthritis (RA) patients after tapering the dose of biological/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs). Methods: This two-center analysis retrospectively investigated the virological and biochemical evidence of HBVr in RA patients who underwent b/tsDMARD dose reduction. Serum levels of viral loads were determined using real-time PCR. Serum levels of alanine transaminase (ALT) were determined using spectrophotometry. Results: Among a total of 40 HBsAg+ RA patients who tapered b/tsDMARDs, 14 (35%) used tocilizumab; 12 (30%) used tumor necrosis factor (TNF)-α inhibitors; and the rest used either abatacept or tofacitinib. We found that patients who had detectable HBV DNA before tapering achieved a one-log reduction in HBV DNA levels, in contrast to the findings in the other 12 patients who did not taper b/tsDMARDs (no change in HBV DNA levels with time). The incidence of HBVr (increased viral loads with hepatitis) was 4.62 (95%CI: 2.08, 10.28) and 2.26 (95%CI: 0.56, 9.02) events per 100 person-years before and after b/tsDMARD tapering, respectively. Conclusions: The HBV viral load decreased after the tapering of b/tsDMARDs in RA patients with detectable HBV DNA. Dose reduction in b/tsDMARDs might be beneficial.