Screening of immune status in patients with acute coronary syndrome

The aim of the work was to assess differences in clinical pattern and immunological status in patients with acute coronary syndrome (ACS) and Post-COVID syndrome (PCS), taking into account the level of TREC in the peripheral blood. A total of 32 patients aged 40 to 65 years with ACS and a history of COVID-19 from 6 to 18 months were examined. All patients underwent coronary angiography and stenting of the coronary arteries. To determine TREC levels in peripheral blood, the TREC/KREC-AMP PS reagent kit (Pasteur Research Institute, St. Petersburg) was used. To determine the studied subpopulations of peripheral blood lymphocytes, Beckman Coulter (USA) reagents – TetraChrome were used. The analysis of samples was studied with a Navios™ flow cytometer (Beckman Coulter, USA). Among patients with ACS and PCS, the TREC content was determined in 32 patients, including 28 with unstable angina and 3 with acute myocardial infarction without ST segment elevation. The patients were divided into groups depending on the TREC content: (1) with a reduced TREC level (1st group) and with normal index values (2nd group). One should note that only one patient from this group had reduced KREC values, the rest being within normal range. Therefore, we did not find any effect of KREC on clinical and immunological features of subjects with ACS and SCS. Individuals with reduced TREC levels had a lower relative and absolute number of T-helper cells (p 0.01), and their immunoregulatory index was lower (p 0.01). At the same time, an increase in relative (p 0.01) and absolute numbers of T cytotoxic cells (p 0.05), as well as percentage of T-NK lymphocytes (p 0.05) was noted in this group of patients. Also, in patients from the 1st group, we have seen a tendency to increase in NK lymphocyte numbers and decrease in B lymphocytes (CD3-CD19+). A low-TREC subgroup of patients with ACS and PCS showed a more severe clinical course. However, due to limited group of patients, further study of such relations is planned with a larger set of clinical cases. Detection of immune disorders using the mentioned screening methods requires novel approaches to immunocorrection of these disorders which are currently discussed by cardiologists.