LAUSR

Abstract Objectives Rheumatoid arthritis (RA) in patients undergoing immunosuppressive therapy (IS) is sometimes involved with other iatrogenic immunodeficiency-associated lymphoproliferative disorders (LPD). We aimed to clarify the effects of LPD treatment on RA and the current status of RA treatment options after LPD onset and subsequent IS withdrawal. Methods We retrospectively analyzed data of patients who had RA with LPD and examined the relationship between LPD course and RA treatment as well as that between RA relapse and LPD treatment. Results LPD patients were categorized into two groups: patients who regressed spontaneously (n = 19) and those who needed chemotherapy (n = 12). The chemotherapy group had significantly less RA relapse than the spontaneous regression group (p = .041). RA almost relapsed early in the spontaneous regression group and needed treatment for RA. Chemotherapy with rituximab prevented long-term RA relapse, and RA did not relapse for long even after rituximab monotherapy. The total dose of rituximab in monotherapy correlated with the time to RA relapse. Six patients with RA relapse received biologics and had no LPD relapse for more than 1 year. Conclusions Rituximab in chemotherapy for LPD may help prevent RA relapse with LPD. Large-scale studies are required in the future for verification.