Lipoprotein-associated phospholipase A2 and the risk of ischemic stroke

Aim: Lipoprotein-associated phospholipase A(2)(Lp-PLA(2)) is an enzyme accumulated in atherosclerotic plaques and causes plaques inflammation that can induce plaque rupture. The aim of this work is to compare serum Lp-PLA(2) concentration in healthy subjects and in patients with arterial hypertension (AH), ischemic heart disease (IHD) and ischemic stroke (IS) so that we could assess utility of Lp-PLA(2) as a biomarker for IS risk. AH and IHD are considered risk factors for IS, therefore we measured serum Lp-PLA(2) concentration also in patients with these diseases. Methods: Serum Lp-PLA, concentration was determined by diaDexus PLAC (R) Test ELISA Kit (Diadexus, Inc., San Francisco, USA), a sandwich enzyme immunoassay. The statistical analysis was performed with IBM SPSS Statistics 24 (IBM Corp., New York, USA) using the Fisher's exact test and non-parametric correlations. Results: Our cohort comprised of 401 subjects in total (43% males), 80 subjects in the group of healthy individuals (35% males), 96 subjects in the group with AH (43% males), 85 subjects in the group with IHD (39% males) and 140 subjects in the group with IS (49% males). Serum Lp-PLA(2) concentration in the group of healthy individuals was significantly lower than that in the group with AH (p = 0 x 10(-3)), IHD (p = 0 x 10(-3)) and IS (p = 0 x 10(-3)). Conclusion: Our study confirmed the assumption that people with AH, IHD and IS have higher levels of serum Lp-PLA(2) concentration than healthy people hence a higher incidence of inflamed atherosclerotic plaques and higher risk of rupture of these plaques, but a higher level of serum Lp-PLA(2) persisted in people with AH, IHD and IS in our cohort despite the statin therapy, leading us to conclude that the role of Lp-PLA(2) in the development and intensification of atherosclerotic plaque inflammation may be more complicated than only the hydrolysis of oxidized LDL in atherosclerotic plaque.