This immunoassay kit allows for the specific measurement of human Lp-PLA2 concentrations in serum and plasma.
Introduction
Lipoprotein-associated phospholipase A2 (Lp-PLA2, also known as platelet activating factor acetyl-hydrolase), is a relatively recent marker that has emerged as a major, independent predictor of CHD. Lp-PLA2 is an active phospholipase that circulates in plasma bound to LDL, and it appears to act almost exclusively on oxidized LDL to generate lysophosphatidyl-choline, which is proinflammatory and is considered to be atherogenic. Thus, Lp-PLA2 represents an interesting link between lipoproteinoxidation and vascular inflammation, which likely explain its strong, independent association with CHD risk. Data from the recent ARIC study have indicated that the predictive power of Lp-PLA2 is attenuated after adjustment for multiple established risk factors, but remains strong in the sub-group with LDLcholesterol levels of < 130 mg/dL. Moreover, this study indicated that there was an interaction between Lp-PLA2 and CRP levels, and the strongest predictor for CHD risk (hazard ratio = 2.95) was found for the combination of high CRP (> 3 mg/L) and high Lp-PLA2 (= 422 µg/L) in the presence of LDL < 130 mg/dL. Therefore, CRP and Lp- PLA2 appear to be particularly useful in predicting CHD risk in the presence of LDL cholesterol in the normal range.
Test principle
This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for Lp-PLA2 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any Lp-PLA2 present is bound by the immobilized antibody. An enzyme-linked monoclonal antibody specific for Lp-PLA2 is added to the wells. Following a wash to remove any unbound antibody-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of Lp-PLA2 bound in the initial step. The color development is stopped and the intensity of the color is measured.
