Phospholipase A₂: Its Usefulness in Laboratory Diagnostics

Abstract

Phospholipase A₂ (PLA₂) is an enzyme that catalyzes the hydrolysis of membrane phospholipids. This article reviews the source and structure of PLA₂, the involvement of the enzyme in various biological and pathological phenomena, and the usefulness of PLA₂ assays in laboratory diagnostics. Of particular importance is the role of PLA2 in the cellular production of mediators of inflammatory response to various stimuli. Assays for PLA₂ activity and mass concentration are discussed, and the results of enzyme determinations in plasma from patients with different pathological conditions are presented. The determination of activity and mass concentration in plasma is particularly useful in the diagnosis and prognosis of pancreatitis, multiple organ failure, septic shock, and rheumatoid arthritis. A very important result is the demonstration that PLA₂ is an acute phase protein, like CRP. Indeed, there is a close correlation between PLA₂ mass concentration and CRP levels in several pathological conditions. Although the determination of C-reactive protein is much easier to perform and is routinely carried out in most clinical laboratories, the assessment of PLA₂ activity or mass concentration has to be considered as a reliable approach to obtain a deeper understanding of some pathological conditions and may offer additional information concerning the prognosis of several disorders.

KEYWORDS: :

• phospholipase A₂
• eicosanoids
• inflammation
• pancreatitis
• multiple organ failure
• septic shock
• rheumatoid arthritis
• acute phase protein.