Assessment of the effectiveness of immunocorrective therapy in moderate and severe COVID-19

Abstract

Evaluating the effectiveness of immunocorrective therapy in patients with severe COVID-19 is an urgent task, as it predicts the future course and outcome of the disease. Aim: To use the ROC analysis for prediction of changes in the composition of platelets, leukocytes and their populations as well as their interrelations on the 6th day after the start of using the immunocorrectors, tocilizumab and thymalin. Methods. Blood cell count and their ratios were analyzed for 159 patients with severe COVID-19. The patients were divided into three groups: 1, control, basic treatment regimen, 44 patients, age 62 ± 13.4 yrs; 2, basic treatment regimen plus tocilizumab, 4-8 mg/kg, iv, once, 81 patients, age 58±10.9 yrs; 3, basic treatment regimen plus thymalin, 10 mg, im, once per day for 5 days, 34 patients, age 61.3±10.1 yrs. Blood components were analyzed on the 1st and 6th days of therapy in the control group, after a single injection of tocilizumab, and on the day following withdrawal of thymalin. Conventional therapy was continued until the patients were discharged from the hospital. Results. In the control group, all the blood count values, as well as their ratios, were in the scale zone corresponding to unsatisfactory or weak assessment. There was no consistency with the results of therapy. On the 6^th day of tocilizumab treatment, there was a significant increase in the number of eosinophils and platelets, which should be regarded as a “good effect” according to the AUC scale. In this group, the ratio of platelets/leukocytes increased by 1.6 times and platelets/lymphocytes by 1.4 times. This can be regarded as a predictor of an unfavorable outcome of COVID-19. Under the influence of thymalin on the 6th day of therapy, the number of lymphocytes increased by 2 times, while the platelet/lymphocyte ratio decreased by 28.6% and neutrophils/lymphocytes by 50%. Furthermore, the number of leukocytes increased 1.3 times, the number of monocytes increased 2 times, and the number of platelets increased 1.5 times. These data indicate a complex immunoprotective effect of thymalin in patients with severe COVID-19. Conclusion. Using ROC analysis in patients with severe COVID-19, changes from the 1st to the 6th day of treatment were found in the count and ratios of blood cells in control (treatment as per protocol) and in patients treated with the immunocorrectors, tocilizumab and thymalin. Presented graphs enable effective assessment of the structure and significance of changes in various therapeutic approaches.