Abstract: Objective To evaluate the relationship between plasma lipoprotein-associated phospholipase A2(Lp-PLA2) concentration and characteristics of intracranial atherosclerotic plaque stability. 
Methods Eighty-three patients with acute ischemic stroke (AIS)were retrospectively enrolled. Plasma Lp-PLA2 concentration was determined in all patients. High resolution magnetic resonance imaging(HR-MRI) was used to determine the stenosis rate of intracranial vessels and plaque stability characteristics, including plaque enhancement, regularity of the plaque surface and T1WI hyperintensity in the plaque. A binary Logistic regression model was established to evaluate the relationship between high LP-PLA2 concentration and characteristics of intracranial plaque stability by adjusting for demographic and related lipid confounders. 
Results There were significant differences in total cholesterol(TC), low density lipoprotein(LDL) and dyslipidemia in patients with high Lp-PLA2 level. After adjustment for demographic and related lipid factors, increased Lp-PLA2 concentration was independently associated with plaque enhancement (P=0.005,OR=21.347, 95%CI 2.645-177.604) and plaque surface irregularity (P=0.044,OR=3.008,95%CI 1.030-8.780). 
Conclusion Increased Lp-PLA2 concentration is associated with intracranial plaque stability.

Key words: plaque, atherosclerotic, high-resolution MRI, plasma lipoprotein-associated phospholipase A2