Relationship between lymphocyte count and risk of infection in Japanese rheumatoid arthritis patients treated with tofacitinib

Tanaka et al. observed that in Japanese patients with rheumatoid arthritis treated with tofacitinib, those with absolute lymphocyte counts (ALCs) <0.5x10³ cells/mm³ had a higher risk of serious infections and herpes zoster events compared to patients with higher ALC levels. This threshold may help identify increased infection risk in this population

This post hoc analysis of clinical trial data over 75 months assessed changes in ALCs and lymphocyte subsets, correlating these with infection rates. ALCs were stable overall but associated with higher infection rates, supporting a clinically relevant threshold for risk.