Lp-PLA2

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an enzyme that circulates bound to LDL particles and is released when these particles become trapped and oxidized within arterial walls. Unlike hsCRP, which reflects general systemic inflammation from any source, Lp-PLA2 is highly specific to vascular inflammation — making it a more targeted marker of active atherosclerotic disease.

Lp-PLA2 plays a direct role in plaque destabilization. When LDL particles infiltrate the arterial wall and become oxidized, Lp-PLA2 cleaves the oxidized phospholipids, producing inflammatory mediators that recruit macrophages and promote the formation of the necrotic core within plaques. This process is what makes plaques vulnerable to rupture — the event that triggers most heart attacks and strokes.

Elevated Lp-PLA2 is particularly concerning when found alongside elevated hsCRP, as the combination indicates both systemic and vascular inflammation — a high-risk phenotype. The PLAC test for Lp-PLA2 is FDA-cleared for cardiovascular risk assessment. When elevated, it should prompt aggressive management of modifiable cardiovascular risk factors and consideration of advanced imaging to assess plaque burden directly.