The synovial changes in rheumatoid arthritis under corticosteroid treatment.

Light microscopic examination of histological sections of synovial membrane from patients with rheumatoid arthritis revealed that prolonged administration of corticosteroids had an inhibiting effect on the participation of lymphocytes and histiocytes in inflammatory infiltrates, as well as on the hypertrophy of synoviocytes, the proliferation of fibroblasts, the accumulation of fibrocytes, the deposition of fibrous tissue, and the formation of villi. Short-term (i.e., 12- to 24-h) steroid administration inhibited proliferation of fibroblasts only.