Size Matters! Anti-HBs Titer and HBV Reactivation During Anti-TNF Therapy.

Anti-HBs titers greater than 100 iU/L protect against clinically relevant HBV reactivation, while patients with low anti-HBs titers or negative anti-HBs had more clinically relevant HBV reactivation and higher rates of HBsAg sero-reversion. This suggests the importance of baseline quantitative anti-HBs prior to starting anti-TNF therapy and consideration vaccination for boosting anti-HBs titers prior to and/or during therapy.