Objective: To investigate clinical characteristics and time course of lymphoproliferative disorders (LPDs) in rheumatoid arthritis (RA) patients after methotrexate (MTX) discontinuation, in those who achieved spontaneous regression (SR).
Methods: We retrospectively reviewed clinical data from RA patients with LPDs obtained from eight institutions between 2000 and 2017 and compared clinical and pathological findings between SR and non-SR groups.
Results: Among 232 RA patients with LPDs, 216 were treated with MTX at the onset of LPD and 144 (66.7%) achieved SR after MTX discontinuation. Higher MTX doses, high titers of anti-CCP antibodies (>13.5 U/mL), and lower LDH and soluble IL-2 receptor levels were associated with SR. Lymphocyte count was decreased at LPD onset and increased at 2 weeks after MTX discontinuation in the SR group. Epstein-Barr virus-positive mucocutaneous ulcer, reactive lymphoid hyperplasia and unclassifiable B-cell lymphoma, were more frequent in the SR than in the non-SR group. In multivariable analysis, diffuse large B-cell lymphomas was an independent predictive factor for non-SR. In the patients with SR, 73.9% achieved partial or complete regression as early as 2 weeks after MTX discontinuation.
Conclusion: SR and non-SR in RA patients with LPDs after MTX discontinuation were associated with certain clinical characteristics.
Keywords: Rheumatoid arthritis; lymphoproliferative disorder; methotrexate; prognostic factors; spontaneous regression.
© 2021 Japan College of Rheumatology.