CORRELATIONS BETWEEN PAF-ACETHER AND TUMOR-NECROSIS-FACTOR IN RHEUMATOID-ARTHRITIS - INFLUENCE OF PARENTERAL CORTICOSTEROIDS

The aim of this study was to evaluate the presence of PAF-acether (PAF ), its specific degrading enzyme acetylhydrolase, and tumor necrosis f actor (TNF) concentrations in blood and synovial fluid (SF) from patie nts with active RA. The variations of the mediators were also evaluate d after corticosteroid perfusions in 7 patients. Lipo-PAF (PAF complex ed to lipoproteins) was the main form of PAF detected both in blood an d in SF whereas unbound PAF was uncommon. Acetylhydrolase activity was also present in SF with a strong correlation between serum and SF lev els. TNF was detected in most of the samples, and TNF and acetylhydrol ase levels were strongly correlated both in blood and in SF. Despite d ramatic clinical improvement, corticosteroid treatment was not accompa nied by a significant reduction of the concentration of blood mediator s, suggesting that these molecules should not be considered as markers of disease activity.