Phospholipase A2 sécrétée de type IIA et syndrome inflammatoire

Abstract

Phospholipase A₂ are enzymes that hydrolyse the sn-2 position of glycerophospholipids, and play a pivotal role in the generation of lipid inflammatory mediators. The type IIA secretory phospholipase A₂ (sPLA₂) is a distal effector of inflammation, produced by a number of cells challenged with inflammatory stimuli such as tumor necrosis factor or interleukin-1. Hydrolysis of the glycerophospholipids generates arachidonic acid, which is implicated in eicosanoid synthesis, and some important lipid mediators such as lyso-platelet activating factor, lysophosphatidic acid (LPA), or lysophosphatidylcholine (LPC). High levels of sPLA₂ are found in the plasma of patients suffering from sepsis, septic shock, adult respiratory distress syndrome and multiple organ failure. The levels are correlated to the intensity of the systemic inflammatory response and possibly to the outcome. This review presents important results concerning the pathophysiological implications of sPLA₂ in inflammatory disorders. We also present the role of LPA and LPC. The utility of the determination of sPLA₂ activity in clinical practice is discussed.