Methods for detecting Lp-PLA2 activity and inhibition of Lp-PLA2 activity

An improved Lp-PLA2 enzyme assay method for plasma or serum sample obtained from a patient treated orally with an Lp-PLA2 inhibitor, wherein the improvement provides for detecting about 85% or greater inhibition of the enzyme by the Lp-PLA2 inhibitor, the method comprising:

• (a) contacting 110 μL of a solution comprising:
• a solution comprising 90 mM 1-myristoryl-2-(4-nitrophenylsuccinyl) phosphatidylcholine contacted with a solution comprising 200 mM HEPES, 200 mM NaCl, 5 mM EDTA, 10 mM CHAPS, 10 mM sodium 1-nonanesulfonate at a pH 7.6 in a ratio of 0.66 μL to 110 μL;
• with at least one 25 μL plasma or serum sample from an animal;
• with 25 μL each of a p-nitrophenol standard solution comprising;
• 4, 3, 2, 1, 0.4 or 0.2 nmol/μL p-nitrophenol in methanol;
• and
• (b) preparing a blank comprised of 25 μL of phosphate buffered saline or H2O;
• and
• (c) determining Lp-PLA2 activity using a colormetric measurement.