Interleukin 1 activity in the synovial fluid of patients with rheumatoid arthritis.
The synovial fluids (SF) of patients with rheumatoid arthritis (RA) were investigated for their effects on thymocytes of C3H/HeJ mice. Of the 20 SF tested, 17 (85%) showed an augmentation of the phytohaemagglutinin (PHA) induced thymocyte stimulation. Out of 16 SF of patients with osteoarthrosis, such an activity was detected in only one (6.25%). Further characterisation of the amplification factor revealed that (1) the SF of RA patients augmented both the PHA and the Concanavalin A response of the thymocytes (2) in the absence of mitogens, SF-treated thymocytes showed an increased uptake of 3H-thymidine, (3) the SF did not propagate the growth of an interleukin 2 dependent ovalbumin specific T cell clone, but (4) the SF were found to be required for optimal interleukin 2 release by spleen cells stimulated with suboptimal doses of lectin. Based on these biological effects the factor in the SF of RA patients is suggested to represent an interleukin 1 (IL-1). IL-1 produced in cultures by activated macrophages has been shown to stimulate T and B cell functions and to induce the production of collagenase and prostaglandins by cultured synovial cells. Both properties of IL-1 could be relevant in the pathogenesis of RA.
D000818:Animals; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D006801:Humans; D007375:Interleukin-1 / Q000502:physiology*; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D051379:Mice; D008809:Mice, Inbred C3H; D010003:Osteoarthritis / Q000276:immunology; D013582:Synovial Fluid / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
D007375:Interleukin-1; D007376:Interleukin-2