LIPOPROTEIN-ASSOCIATED PHOSPHOLIPASE A2
- LIPOPROTEIN-ASSOCIATED PHOSPHOLIPASE A2
- Start Date
- Expiration Date
- PLAC; Lp-PLA2; Vascular inflammatory marker
- CPT Codes
- Reference Test
- Transport Info
Centrifuge and immediately transfer plasma to separate plastic tube
- Fasting Required?
- Patient Instructions
- Reference Range
Enzyme-Linked Immunosorbent Assay (ELISA)
Risk factor for coronary heart disease (CHD).
Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a calcium independent enzyme that is associated with low-density lipoprotein (LDL) in human plasma. It is produced by macrophages and is present in greater concentrations in atherosclerotic lesions. Research has suggested that Lp-PLA2 is involved in the oxidative modification of LDL that can lead to plaque formation and the generation of pro-inflammatory molecules. These molecules can recruit macrophages and contribute to the formation of atherosclerotic plaques. Lp-PLA2 has been shown to be an independent risk factor for coronary heart disease (CHD) in several studies. In one study, the Lp-PLA2 concentration was shown to be significantly elevated in patients with angiographically proven coronary artery disease when compared to age-matched controls. In a retrospective case-control study using specimens from hypercholesterolemic men (WOSCOPS), a twofold greater risk of CHD was seen for subjects in the upper quintile of Lp-PLA2 concentrations. In a case-cohort study (ARIC), Lp-PLA2 was a significant predictor of CHD risk, particularly in individuals with LDL < 130 mg/dL. A significant interaction between Lp-PLA2 and LDL was found and for individuals in the high LDL group, Lp-PLA2 was predictive when higher Lp-PLA2 cutpoints were used. Both studies (WOSCOPS and ARIC) found that Lp-PLA2 was independent of the inflammatory CHD marker, C-reactive protein. The ARIC study also showed that Lp-PLA2 is additive to hs-CRP in risk prediction. In addition, preliminary analyses from the MONICA Augsburg cohort have shown that Lp-PLA2 levels predict a 14 year risk of events in men with moderately elevated cholesterol levels. The determination of Lp-PLA2 should be used in conjunction with clinical evaluation and patient risk assessment to assist in predicting patient risk CHD. This test does not replace blood cholesterol tests or the use of other traditional risk factors for CHD. It does provide additional risk information when used in conjunction with other traditional markers.