Lymphoid irradiation in intractable rheumatoid arthritis. Long‐term followup of patients treated with 750 rads or 2,000 rads

Abstract

Twenty patients with intractable rheumatoid arthritis were randomized to receive 750 or 2,000 rads of lymphoid irradiation (LI) in a double‐blind comparative study, and were followed for a maximum of 48 months (mean 40 months) after treatment. During followup, sustained immunomodulation (including lymphopenia, particularly of the T helper cell subset; reduced ratio of helper cells to suppressor cells; and impaired in vitro lymphocyte proliferation in response to phytohemagglutinin and pokeweed mitogen) was observed. Significant improvements in early morning stiffness, Ritchie articular index, pain score, grip strength, and 15‐meter walk time were observed in both treatment groups, but these were not sustained through the followup period. Progressive joint damage was observed radiologically in both groups during followup. Thus, LI induced sustained immunosuppression, but resulted in only shortlived clinical improvement and was associated with progressive joint erosion in these patients.