Distribution and possible role of pro- and anti-inflammation macrophage subpopulations in different types of carotid atherosclerotic plaques

The analysis of the distribution and the possible role of macrophage subpopulations of (Mf) pro-(M1) and anti-inflammatory (M2) phenotype in the development of atherosclerotic lesions was conducted. Morphohistological assessment of the lesions types was performed according to the WHO classification. In each sample Mf M1 (MCP1 + - cells) and M2 (CD206+ and CD163+ - cells) were detected by immunohistochemical staining. The analysis revealed that in all types of lesions both subpopulations of Mf are present, and the numerical ratio between them can vary significantly in different areas and types of the plaques. Subpopulation Mf M1 mainly concentrates in areas of infiltration by inflammatory cells and active absorption of lipids, and M2 - in the areas of reparation of the intercellular matrix and angiogenesis. Quantitative evaluation of the distribution of both subpopulations in clinically more significant areas of plaques most prone to rupture or thrombosis - in the fibrous caps (adluminal fibrous layers) and shoulders...