Cytokines in synovial fluid. I. The presence of biologically active and immunoreactive IL-1.
Using a sensitive IL-1-dependent T cell clone we estimated interleukin 1 (IL-1)-like activity in a variety of synovial fluids (SF). Although we demonstrate that SF contains potent inhibitors of endogenous and exogenous IL-1 we were able to estimate that samples from rheumatoid arthritis, osteoarthritis and other arthritides contain the equivalent of tens or hundreds of picograms of IL-1 per millilitre, when compared to a standard IL-1 preparation. Although there was some correlation between these results and those obtained using a radio-immunoassay (RIA) for IL-1 beta, the RIA indicated that IL-1 was present in the nanogram range. The results suggest that the importance of inhibitors of IL-1 in SF merits particular attention and that it is also important to consider the bioactivity of cytokines which may be detected by physical methods.
Hopkins
S J
SJ
University of Manchester, Rheumatic Diseases Centre, Hope Hospital, Salford, UK.
Humphreys
M
M
Jayson
M I
MI
D001168:Arthritis / Q000276:immunology*; D001172:Arthritis, Rheumatoid / Q000276:immunology; D001681:Biological Assay; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis*; D010003:Osteoarthritis / Q000276:immunology; D011863:Radioimmunoassay; D013582:Synovial Fluid / Q000276:immunology*
D007375:Interleukin-1