Immunohistochemical and ultrasonic signs of the disturbance of anti-thrombogenic properties of endothelium in atherosclerosis of the carotid sinus

Abstract

Introduction.Endothelial dysfunction is currently believed toplay a crucial role in pathogenesis of atherosclerosis. Nevertheless,there are only few studies that demonstrate the relationshipbetween changes in parameters of the atherosclerotic process andthe main functional properties of endothelium. In addition, thefindings are often controversial, which served as an incentive forthis study. Materials and methods.Thirteen atherosclerotic plaques resectedduring carotid endarterectomy were subjected to immunochemicaland electron microscopy examination. The intensity of expressionof the von Willebrand factor, thrombomodulin, andendothelial nitric acid synthase was assessed semi-quantitativelyand compared to the main parameters of activity and the courseof atherosclerosis in a plaque (volume of atheromatosis, lipophageaggregation, infiltration of the fibrous cap by monocytes and macrophages). Complicated and uncomplicated plaques were alsocompared. Results.The level of von Willebrand factor in the carotid sinusendothelium increased as lipids were accumulated in it and asthe fibrous cap was infiltrated by monocytes and macrophages(р0.017), as opposed to the levels of thrombomodulin and endothelialnitric oxide synthase whose expression did not show theactivity of the atherosclerotic process and did not correlate withthe level of von Willebrand factor. Meanwhile, the expression ofthrombomodulin and endothelial nitric oxide synthase correlatedwith each other (р=0.004). No difference in staining intensity forall three markers was detected between the complicated and uncomplicatedplaques. Ultrasonic analysis of endothelium demonstratedthe strongly pronounced disturbance of anti-thrombogenicityof the vascular wall as a result of numerous defects of theendothelial stratum, adhesion of blood cells to the arterial surfacecausing microthrombi formation and activation of endotheliocytesalong with dystrophic changes in them, necrosis, and exfoliationinto the vascular lumen. Conclusions.The von Willebrand factor is found to have high diagnosticsignificance in the assessment of activity of the atheroscleroticprocess in the carotid sinus and the risk of developing complications. Thrombomodulin and endothelial nitric acid synthaseare not recommended to be used as biomarkers of progression ofatherosclerosis of this localization, since they are not indicative ofthe intensity of inflammatory response and destructive processesin a plaque.

Keywords

• endothelial dysfunction
• atherosclerosis of carotid sinus
• von willebrand factor, thrombomodulin
• endothelial nitric oxide synthase
• morphological study