Relationship between leukotriene B4 and immunological parameters in rheumatoid synovial fluids.

Leukotriene B4 (LTB4) was measured in synovial fluid from 20 patients with rheumatoid arthritis and 15 patients with osteoarthritis. The level of LTB4 was significantly higher in synovial fluid from rheumatoid arthritis patients as compared with synovial fluid from osteoarthritis patients. LTB4 levels also significantly correlated with cell numbers, rheumatoid factor, and immune complexes in synovial fluid from rheumatoid arthritis patients. There was an inverse correlation between LTB4 levels and complement components. The high-pressure liquid chromatography peak of immunoreactivity extracted from the synovial fluid occurred at a retention volume identical to that of authentic LTB4. These results suggest that the increased level of this mediator in synovial fluid may contribute to perpetuation of inflammation and tissue destruction in rheumatoid arthritis.