Interplay between lymphocyte subpopulation, inflammatory cytokines and their correlation with oxidative stress parameters in COVID-19

Our objective was to investigate the inflammatory and oxidative stress markers in patients with moderate and severe form of COVID-19. In addition, we show the correlation between changes in lymphocyte subsets and markers of oxidative stress as a tool for patient classification. IL-6 and VEGF were analysed by utilizing a High Sensitivity Evidence Investigator™ Biochip Array technology. The total antioxidant capacity (PAT) and the free radical concentrations (d-ROM) were measured in serum utilizing analytical photometric system FRAS5. Peripheral blood was used to determine CD45 + mononuclear, B, T, and NK cells using a multi-parameter flow cytometric immunophenotypic test. Statistically significant differences in IL-6 and VEGF levels were observed between the two patient groups. Decreased values of the absolute number of lymphocytes and their CD4 + and CD8 + positive T cells, NK cells, and CD8 were obtained. In the moderate group, good correlations were found between IL-6 and VEGF and NK cells (r = 0.6973, p <0.05; for IL6 and r = 0.6498, p <0, for VEGF. 05). Cytokines were correlated with CD45+ (r = 0.5610, p <0.05; for IL-6 and r = 0.5462, p <0.05 for VEGF). The oxidative stress index can be used as a cheaper alternative and as a triage tool between severe and moderate illnesses, after showing good correlation with more expensive patient classification analysis.