Peculiarities of impaired immunoresistance in the formation of post-COVID syndrome and the acute cardiovascular pathology

Background. Against the background of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and after multiple vaccinations with various vaccines, the effect of the massive antigenic load that various cohorts of patients received and continue to receive is undeniable. The SARS-CoV-2 epidemic is not over, and the long-term persistence of the virus contributes to the formation of various symptoms, complications, and the surgical emergencies. The symptoms of post-COVID syndrome (PCS) associated with the progression of individual disorders of immune resistance and autoimmune component formation in 40 % of patients is a predictor of the cardiovascular pathology. It is very difficult to provide medical care to patients with a comorbid course of PCS and urgent surgical pathology, and the study of imprinting disorders is important. The aim is to determine the role of impaired immune resistance in patients with comorbid PCS and urgent cardiovascular condition and to identify specific markers associated with the severity of the pathology and high risk of mortality. Materials and methods. We examined 145 patients aged 33 to 84 years who had COVID-19 in different periods of the pandemic with the development of PCS and cardiovascular disease (aortic and femoral artery aneurysm, aortic occlusion, aortic stenosis, thrombosis of major vessels, coronary heart disease, infectious endocarditis, myocardial infarction). Methods used were microscopy (light, luminescent, confocal), spectrophotometry, latex agglutination, immunoturbidimetry, gravimetry, flow cytometry, enzyme-linked immunosorbent assay. Results. We revealed an increase in the frequency of urgent surgical cardiovascular pathologies with the risk of thrombogenic disorders due to immunoinflammatory reactions arising against the background of the formed PCS. In the examined patients with comorbidities, temporal manifestations of individual immunopathological reactions of varying severity were found in different periods of the pandemic. In the first period (2020–2021), against the background of persisters presence, violations of humoral and cellular innate immunity were detected (an increase in C3 and C4 complement components and pro-inflammatory interleukins 6 and 18; phagocytosis dysfunction; presence of antibodies to platelets and nuclear components, including aminoacyl-tRNA synthetase). During this period, the examined patients had a significant increase in the serum content of the oligopeptide cytotoxic DAMP fraction (molecular patterns associated with damage). During the second period (2022–2023), patients with a severe course of comorbidity, especially in cases of mortality (17 %), had an increased oligonucleotide DAMP fraction and an expanded complex of PCS symptoms. This was associated with certain changes in markers of adaptive immunity: the violation in the ratio of T lymphocyte subpopulations against the background of lymphopenia, a significant increase in the level of cytotoxicity inducer — a marker of the early activation of T lymphocytes CD3+CD4+CD25+, a significant decrease in the expression of costimulatory molecules CD3+CD4+CD28+ of T helpers, development of mitochondrial dysfunction and a multiple increase in the antinuclear antibodies. Conclusions. Identified immunological markers of severity and the risk of mortality in patients with a comorbid course of PCS and urgent cardiovascular pathology should be taken into account when developing personalized treatment methods.