Lipoxygenation of arachidonic acid as a source of polymorphonuclear leukocyte chemotactic factors in synovial fluid and tissue in rheumatoid arthritis and spondyloarthritis.

The predominant lipoxygenase products of arachidonic acid were extracted and purified from synovial fluid and sonicates of synovial tissue of patients with rheumatoid arthritis (RA), spondyloarthritis (SA), or a noninflammatory arthropathy (NIA). The concentration of 5(S),12(R)-dihydroxy-6,8,10-(trans/trans/cis)-14-cis-eicosatetraenoic acid (leukotriene B4) in synovial fluid was elevated significantly in patients with RA and a positive latex test for rheumatoid factor (P < 0.05, n = 14) and in patients with SA (P < 0.05, n = 10), compared with that of subjects with NIA (n = 9). The content of 5(S)-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE), but not of leukotriene B4, was elevated significantly in synovial tissue of seven patients with RA in comparison with that of four subjects with NIA (P < 0.05). A single intra-articular injection of corticosteroid significantly lowered the synovial fluid level of leukotriene B4 in six patients with RA. These data suggest an involvement of the potent chemotactic factors 5-HETE and leukotriene B4 in human inflammatory disease.