[Leukocyte migration inhibitory factor of synovial fluid lymphocytes in rheumatoid arthritis]

Synovial fluid lymphocytes from patients with rheumatoid arthritis were examined for the presence of leukocyte migration inhibitory factor by the agarose technique of Clausen. T and B lymphocytes were stimulated with phytohemagglutinin, concanavalin A, and pokeweed mitogen, and the culture supernatants were used for the migration inhibitory test. Migration index of the culture supernatants of T cells from rheumatoid synovial fluids was significantly greater than those of peripheral blood from rheumatoid patients and healthy controls. The results indicated that the production of leukocyte migration inhibitory factor following stimulation by mitogens was decreased in the T cells of rheumatoid synovial fluid. In the rheumatoid synovial fluid there was a positive correlation between the migration index and polymorphonuclear leukocyte counts. A similar result was also obtained in the study of B cells from rheumatoid synovial fluid. These results suggest that the rheumatoid synovial lymphocytes have been already activated in the synovial fluid. On the other hand, the supernatants of rheumatoid synovial fluid showed an elevated migration index, exceeded 1.0 and higher than those of osteoarthritic synovial fluid. This suggests that chemotactic factors play an important part in the rheumatoid synovial fluid, though the leukocyte migration inhibitory factor is present in the rheumatoid fluid.