No evidence for a putative involvement of platelet-activating factor in systemic lupus erythematosus without active nephritis

Abstract

Background:Platelet-activating factor (PAF) seems to be implicated in systemic lupus erythematosus (SLE) patients with associated renal diseases.Aims:In this study, we ensured the role of PAF in SLE patients without renal complications.Methods:Blood PAF and acetylhydrolase activity, plasma soluble phospholipase A2, and the presence of antibodies against PAF were investigated in 17 SLE patients without active nephritis and in 17 healthy controls.Results:Blood PAF levels were not different(P=0.45)between SLE patients (6.7±2.8 pg/ml) and healthy subjects (9.6±3.1 pg/ml). Plasma acetylhydrolase activity (the PAF-degrading enzyme) was significantly(P=0.03)elevated in SLE patients (57.8±6.4 nmol/min/ml) as compared with controls (37.9±2.6 nmol/min/ml). Plasma soluble phospholipase A2(the key enzyme for PAF formation) was not different(P=0.6)between SLE patients (59.1±5.1 U/ml) and controls (54.7±2.4 U/ml). Antibodies against PAF were detected only in 3/17 SLE patients. Flow cytometry analysis did not highlight PAF receptors on circulating leukocytes of SLE patients.Conclusion:This clinical study highlights no evidence for a putative important role of PAF in SLE patients without active nephritis.