Interleukin-4, hemopexin, and lipoprotein-associated phospholipase A2 are significantly increased in patients with unstable carotid plaque

Objective: This study aimed to compare the plasma levels of lipoprotein-associated phospholipase A2 (Lp-PLA2), hemopexin (Hpx), and interleukin-4 (IL-4) in patients with carotid artery atherosclerosis based on neurological symptoms and plaque histopathology and to find association between plaque stability and neurological symptoms. This single-center study included patients treated surgically for significant stenosis of the internal carotid artery. Serum levels of biomarkers were determined, and a histopathological analysis of the carotid plaques was performed. Within 70 patients, 40 asymptomatic and 30 symptomatic; 38 patients (54.3%) were diagnosed with unstable carotid plaque and 32 patients (45.7%) had a stable carotid plaque. Significantly higher incidence of unstable carotid plaque was detected in symptomatic patients (p < 0.001). Compared to asymptomatic patients, higher expression of Lp-PLA2 (285.30 +/- 2.05 mu g/l), Hpx (0.38 +/- 0.01 ng/l), and IL-4 (65.77 +/- 3.78 ng/l) in plasma were detected in symptomatic patients. Subsequently, higher expression of Lp-PLA2 (297.34 +/- 2.3 mu g/l), Hpx (0.41 +/- 0.02 ng/l), and IL-4 (64.74 +/- 4.47 ng/l) in plasma was observed in patients with unstable plaques (n=38). Statistically significant (p < 0.001) differences in expression of Lp-PLA2, Hpx, and IL-4 between patients with unstable and stable plaques were detected. Moreover, only the differences between symptomatic and asymptomatic patients in the expression of Lp-PLA2 and IL-4 in plasma were statistically significant (p < 0.001). This study showed that Lp-PLA2, IL-4, and Hpx levels are significantly increased in patients with an unstable carotid plaque.