Biochemical differences in the mass and activity tests of lipoprotein-associated phospholipase A2 explain the discordance in results between the two assay methods

PLAC mass test only detects a small portion of the total Lp-PLA2, mainly the Lp-PLA2 associated with HDL. This is the main cause of the discordance and poor correlation between the PLAC mass and activity tests. Our results demonstrate the PLAC activity test is more accurate in assessing the total level of circulating Lp-PLA2.