Immunological analysis of carotid artery plaques and its relationship to the gray scale median value obtained by ultrasound

Abstract

Abstract Introduction A gray scale median (GSM) value established by ultrasound could potentially reflect atherosclerotic plaque stability in carotid arteries, this stability could be also assessed by the measurements potential pro- and antiiflammatory characteristics of macrophages detected in the plaque. We analyzed association between the GSM value and several macrophage characteristics in carotid artery plaques. Methods Twenty-four patients (14 men, mean age 66.4±4.4 years) underwent ultrasound scan to determine the GSM value in maximum of one day before carotid endarterectomy. Immediately after removal, atherosclerotic plaques were processed for and analyzed by flow cytometric analysis. CD14, CD16, CD36, CD163 and CD206 markers were used to evaluate macrophage polarization. Results The GSM value ranged from 0 to 146. The majority of macrophages were established as CD14+CD16+. These macrophages also often co-expressed CD206, CD36 and CD163 while the expression of CD206 and CD36 in CD14+CD16- cells was lower and the expression of CD163 was almost negligible. Pro- and antiiflammatory macrophage phenotypes based on combination of different expression of CD markers did not correlate with the GSM value. In addition, no significant relationship was found between the GSM value and the presence of traditional cardiovascular risk factors. In patients with history of diabetes mellitus significantly lower percentage of CD14+CD16+CD206- macrophages was observed than in non.diabetics (p<0.05). Conclusion The GSM value did not correlate with potential pro- and antiiflammatory macrophage phenotypes. In addition, in contrast to published data, no relationship was found between the GSM value and the presence of cardiovascular risk factors Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Supported by Ministry of Health, Czech Republic - conceptual development of research organization; Thanks to courtesy of professor Andrew Nicolaides we used software developed by him and his colleagues to assess structure of carotid plaques by ultrasound.