INTEGRATION DIAGNOSTIC CRITERION FOR EVALUATION OF THE SEVERITY OF COVID-19 AND THE RISK OF POST-COVID SYNDROME

The pathophysiology of severe COVID-19 is characterized by changes in the number, phenotype, and function of neutrophil granulocytes (NG). Among the effector antiviral mechanisms of NC, neutrophil extracellular traps (NETs) are one of the most important, but their excessive formation exacerbates inflammation in acute respiratory distress syndrome and contributes to microvascular thrombosis. Their detection and quantification may be important in various forms of the course of COVID-19 to determine the correlation with the outcome of the disease, assess the risk of developing post-COVID syndrome, and possibly monitor future targeted therapy.Purpose of the study: to develop a new diagnostic integration criterion to assess the severity of COVID-19 and the risk of complications in the post-COVID period, including post-COVID syndrome in peripheral blood.Materials and Methods: Peripheral blood (PB) samples were studied from 31 patients with acute COVID-19 (moderate (n=15) and severe (n=16)), 52 patients discharged from the hospital after severe COVID-19 treatment severity, in terms of 30 to 60 days, with post-COVID syndrome (PCS) and 100 healthy volunteers. The parameters of the general clinical blood test (MicroCC-20Plus) were evaluated, the leukocyte formula was calculated in PC smears, taking into account the number of formed NETs and NGs that went into pathological apoptosis. Based on the obtained results, an integration diagnostic criterion was calculated using the formula:.Results. A decrease in IDC was shown in the moderate course of the disease by 8,5 times (p<0,05), and in severe cases by 30 times(p<0,05) compared with the values in the group of healthy individuals. It was also found that in 88,5% of patients with PCS who underwent SARS-CoV-2, no morphologically pathologically altered NG were detected in the PB. At the same time, in 11.5% of patients with PCS, the appearance of NETs and cells with pathological apoptosis was noted, while the IDC of NG-PCS was 8 times less than in the comparison group and did not differ from the parameters of patients with moderate COVID-19 (p>0,05), which dictates the need for further dispensary observation of such patients.Conclusion. The data obtained in this study indicate that the developed integration diagnostic criterion allows us to assess both the severity of COVID-19 in the acute period and the risk of post-COVID syndrome. It should be emphasized that the characteristic changes in NG detected in COVID-19 can be easily identified in PB and consistently monitored by the calculated integral diagnostic criterion. A significant decrease in IDC indicates the persisting hyper activation of NG and the need for targeted immunotherapy aimed at modulating NG dysfunctions