Features of the immune status of patients with acute coronary syndrome who underwent СOVID-19, depending on the number of cytotoxic T lymphocytes (CD8⁺)

Abstract

The 2019 coronavirus disease (COVID-19) pandemic has had an unprecedented impact on health and economies around the world. Direct myocardial injury and cytokine storm, leading to destabilization of preexisting plaques and accelerated formation of new plaques, are two mechanisms that trigger the acute coronary syndrome in COVID-19. There is insufficient data on the immune status of patients with acute coronary syndrome who have undergone COVID-19. The aim of the study was to study T and B cell, humoral immunity depending on the number of cytotoxic T lymphocytes (CD8+) in patients with acute coronary syndrome who underwent COVID-19. Materials and methods of research: 65 men with unstable angina pectoris and acute myocardial infarction (acute coronary syndrome) from 40 to 65 years old, who had previously had COVID-19, were examined. A study of peripheral blood was carried out: complete blood count (Medonic device, Sweden), general and specific IgM, IgG, IgA, compliment fragments (Vector Best, Russia). Subpopulations of T and B lymphocytes were determined by flow cytometry. In persons with acute coronary syndrome who underwent COVID-19 with predominantly normal and elevated levels of cytotoxic T cells, a more severe course of the disease was observed: patients with acute myocardial infarction prevailed, they had longer mortality, longer treatment duration, and stent thrombosis was more common. In patients with elevated cytotoxic T cells, there was a maximum increase in erythrocytes, hemoglobin, hematocrit, lymphocytes of both the total number and subpopulations – T helpers, T-NK lymphocytes, NK lymphocytes, T lymphocytes of early and late activation, B1 and B2 lymphocytes, index of NBT-induced test. In patients with normal levels of NK cells, compared with other groups, there was an increase in spontaneous NBT activity and index, a significant decrease in C3a and C5a complement fragments. Prevalence of stent thrombosis and mortality in the group of patients with normal levels of cytotoxic T cells may indicate torpidity of the immune system in these patients with poor outcomes.