title: Lipoprotein-associated phospholipase A(2), platelet-activating factor acetylhydrolase: a potential new risk factor for coronary artery disease.
abstract: A specific and robust immunoassay for the lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), platelet-activating factor acetylhydrolase, is described for the first time. The immunoassay was used to evaluate possible links between plasma Lp-PLA(2) levels and atherosclerosis risk amongst susceptible individuals. Such an investigation was important because Lp-PLA(2) participates in the oxidative modification of low density lipoprotein by cleaving oxidised phosphatidylcholines, generating lysophosphatidylcholine and oxidised free fatty acids. The majority of Lp-PLA(2) was found associated with LDL (approximately 80%) and, as expected, enzyme levels were significantly positively correlated to LDL cholesterol. Plasma Lp-PLA(2) levels were significantly elevated in patients with angiographically proven coronary artery disease (CAD) when compared with age-matched controls, even though LDL cholesterol levels did not differ significantly. Indeed, when included in a general linear model with LDL cholesterol and other risk factors, Lp-PLA(2) appeared to be an independent predictor of disease status. We propose, therefore, that plasma Lp-PLA(2) mass should be viewed as a potential novel risk factor for CAD that provides information related to but additional to traditional lipoprotein measurements.
authors.affiliation: Department of Pathological Biochemistry, 4th Floor QEB, Glasgow Royal Infirmary University NHS Trust, Glasgow, UK. m.caslake@clinmed.gla.ac.uk
authors.forename: M J
authors.initials: MJ
authors.lastname: Caslake
authors.forename: C J
authors.initials: CJ
authors.lastname: Packard
authors.forename: K E
authors.initials: KE
authors.lastname: Suckling
authors.forename: S D
authors.initials: SD
authors.lastname: Holmes
authors.forename: P
authors.initials: P
authors.lastname: Chamberlain
authors.forename: C H
authors.initials: CH
authors.lastname: Macphee
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D001161:Arteriosclerosis / Q000000981:diagnostic imaging / Q000201:enzymology* / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D017023:Coronary Angiography; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D010741:Phospholipases A / Q000097:blood* / Q000276:immunology; D010972:Platelet Activating Factor / Q000276:immunology / Q000378:metabolism*; D015539:Platelet Activation; D011379:Prognosis; D012307:Risk Factors
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; D008055:Lipids; D010972:Platelet Activating Factor; D010741:Phospholipases A; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase