Background: Though concern of hepatitis B virus (HBV) reactivation by antirheumatic agents has limited therapeutic opportunities in HBV-infected rheumatoid arthritis (RA) patients, the relative risks (RR) among such agents have not been clarified.
Objective: We compared the reporting of antirheumatic-agent-associated hepatitis B.
Patients: We assessed 92 hepatitis B cases and 98,069 controls from a population of 98,161 RA patients registered into the US Food and Drug Administration's (FDA's) adverse event database between 2004 and 2010.
Measurements: A reporting odds ratio (ROR), a signal suggesting a risk for hepatitis B among antirheumatic agents, was measured.
Results: Treatment with corticosteroids [ROR 2.3 (95% confidence interval 1.3-4.0)], methotrexate [4.9 (3.9-6.0)], rituximab [7.2 (5.3-9.9)], tacrolimus [4.2 (1.5-11.9)], or reporting from Japan [2.2 (1.1-4.2)] were associated with higher signal, whereas adalimumab had a lower ROR [0.2 (0.1-0.4)].
Limitations: There are known limitations of spontaneous reporting, such as underreporting, the Weber effect, reporting bias, indication bias, and limited clinical information such as HBV status.
Conclusions: Adalimumab's low reporting rate is most likely be due to notoriety. However, the possibility that adalimumab might suppress reactivation of HBV cannot be denied. Until the possibility is clarified in well-designed clinical studies, physicians should use adalimumab cautiously in patients with HBV.