PAF and its metabolic enzymes in healthy volunteers: Interrelations and correlations with basic characteristics

PAF (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine), a potent inflammatory mediator, is synthesized via the remodeling and the de novo route, key enzymes of which are acetyl-CoA:lyso-PAF acetyltransferase (lyso-PAF-AT) and DTT-insensitive CDP-choline:1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-CPT), respectively. PAF-acetylhydrolase (PAF-AH) and its extracellular isoform lipoprotein-associated phospholipase-A2 (Lp-PLA2) catabolize PAF. This study evaluated PAF levels together with leukocyte PAF-CPT, lyso-PAF-AT, PAF-AH and Lp-PLA2 activities in 106 healthy volunteers. Men had lower PAF levels and higher activity of both catabolic enzymes and lyso-PAF-AT than women (P-values <0.05). Age was inversely correlated with PAF levels in men (r = −0.279, P = 0.06) and lyso-PAF-AT in women (r = −0.280, P = 0.05). In contrast, Lp-PLA2 was positively correlated with age (r = 0.201, P = 0.04). Moreover, PAF-CPT was positively correlated with glucose (r = 0.430, P = 0.002) in women. In addition, Principal Component Analysis revealed three PAF metabolic patterns: (i) increased activities of PAF-CPT and PAF-AH, (ii) increased activities of PAF-CPT and lyso-PAF-AT and (iii) increased activity of Lp-PLA2. The present study underlines the complexity of PAF's metabolism determinants.

► PAF and its key metabolic enzymes were measured in healthy volunteers. ► Men had lower PAF and higher lyso-PAF-AT, PAF-AH and Lp-PLA2 than women. ► Age was positively related to Lp-PLA2 and negatively related to PAF and lyso-PAF-AT. ► PAF biosynthetic enzymes were positively correlated in multi-adjusted analysis. ► Three PAF metabolic patterns were identified with PCA analysis.