Presence of paf-acether in rheumatic diseases.

Paf-acether (paf) is a naturally occurring phospholipid involved in inflammatory processes. The presence of paf, its precursor lyso paf, and lipo-paf has been determined in blood and synovial fluid from 13 patients with rheumatoid arthritis (RA), 11 with spondylarthropathies, eight with other inflammatory rheumatisms, 13 with chondrocalcinosis, 15 with osteoarthritis, and also in blood from nine healthy subjects. Paf and lipo-paf were measured by rabbit platelet aggregation after isolation by high performance liquid chromatography, whereas lyso paf was first chemically acetylated to give paf. Lipo-paf in blood was higher in patients than in controls; lipo-paf concentrations in blood and in synovial fluid were significantly higher in rheumatoid arthritis than in osteoarthritis and chondrocalcinosis. By contrast, paf and lyso paf reached their lower values in rheumatoid arthritis. The amounts of lipid mediators were not correlated with biological parameters of inflammation. Lipo-paf, which is considered as a storage form of paf, may be the important form of paf in active inflammatory rheumatism.