Oxidative stress index as prognostic marker for disease severity and its correlation with proinflammatory cytokines and lymphocyte subpopulation in COVID-19 patients

Abstract

Introduction The ultimate goal of the SARS-CoV-2 virus is to learn how to evade the host's immune system . The pathogenicity of the virus, the comorbidities of infected individuals, and the ability of the host immune system to respond to induced cytopathic effects have a profound effect on the course and outcome of the disease. Our aim was to analyze several inflammatory, clinical laboratory parameters and oxidative stress markers and to provide comprehensive view of them for their future implementation in routine clinical practice. Method 35 patients, positive on SARS-CoV-2 were hospitalized at the University Clinic for Infectious Diseases and Febrile Conditions in Skopje. All patients were not vaccinated, since the study was performed before the onset of the national vaccination program. The total antioxidant capacity (PAT) and the plasma peroxide (d-ROMs) concentrations were performed on the FRAS5 analytical photometric system. The multi parameter flow cytometry was performed on full blood immediately after sample collection. Immunophenotyping was done by using BD FACSCanto™ II analyzer on lysed whole blood samples. For the simultaneous quantitative detection of multiple analytes from a single patient sample for IL-6 and VEGF we have used the High Sensitivity Evidence Investigator™ Biochip Array technology. Results Patients with moderate form of the disease had lower values of the measured concentration of dROMs and hence lower oxidative stress index when compared to the patients classified with the severe form of the disease (p=0.0001). We report a statistically significant difference of IL-6 and VEGF levels between the moderate and severe groups of patients (p=0.0001). We have observed decreased levels of absolute leukocytes count, CD45+ mononuclear and its subsets CD4+, CD8+, CD3+, NK cells (p<0.05). Also, CD19+ and CD45+ were decreased in the severe group in comparison to the group of patients with moderate COVID-19 (p>0.05). The oxidative stress parameters, OSI and d-ROM demonstrated a good correlation with CD45+ and CD4+. Additionally, only in the moderate group, we have obtained a good correlation amongst the investigated cytokines (IL-6 and VEGF) and NK cells was obtained (namely for IL-6, r=0.6973, p<0.05; and for VEGF, r=0.6498, p<0.05), whereas in the severe group only these cytokines correlated with CD45+ (for IL-6, r=0.5610, p<0.05; and for VEGF, r=0.5462, p<0.05). Conclusion 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