Lipoprotein-associated phospholipase A2 (Lp-PLA2) also known as platelet-activating factor acetylhydrolase (PAF-AH) is a phospholipase A2 enzyme in humans. Lp-PLA2 is a 45 kDa protein of 441 amino acids encoded by the PLA2G7 gene.

Some recent studies have shown that Lp-PLA2 is an independent risk marker for cardiovascular disease (CVD), including coronary heart disease (CHD), and ischemic stroke. In these studies, increased concentrations of Lp-PLA2 were seen in many people who were diagnosed with CHD and ischemic stroke, regardless of other risk factors. These findings make relatively the new 
test potentially useful among the growing number of cardiac risk markers used to determine a person's risk of developing CVD.

Lp-PLA2 is specific for vascular inflammation and is a circulating measure of the progression of rupture-prone plaque. Following production by inflammatory cells, this enzyme cleaves oxidized phospholipids, generating pro-inflammatory molecules and oxidized fatty acids. Elevated Lp-PLA2 levels can predict the development of coronary artery disease in apparently healthy individuals and the risk of future adverse cardiac and cerebrovascular events. The Lp-PLA2 tests are meaningful for assessing risk of coronary artery disease and stroke.