The role of redox status in platelet dysfunction in severe COVID-19-associated pneumonia

BACKGROUND: Platelet dysfunction in patients with COVID-19 is a well-known fact; however, its formation mechanisms remain unclear. AIM: To evaluate the role of oxidative stress in dysfunction of platelets in the patients with severe COVID-19-associated pneumonia. MATERIALS AND METHODS: The study has involved patients with COVID-19 (n = 27) aged 47 to 75 with more than 50% lung damage according to the chest multi-slice computed tomography. The control group has included healthy people comparable in sex and age (n = 24). All the patients have undergone evaluation of the number of platelets in blood, measurement of platelet aggregation induced by adenosine diphosphate, collagen, adrenaline and ristocetin and the level of lipid peroxidation and protein oxidative modifications products in platelet-rich plasma. The calculation and analysis of the obtained data has been carried out using the IBM SPSS Statistics v. 23. RESULTS: For the patients with severe COVID-19, a decrease in the number of platelets in the blood is characteristic. Acceleration of platelet aggregation induced by collagen and ristocetin has been observed on the 1st day, with the induction of adenosine diphosphate, collagen, adrenaline and ristocetin on the 8th day of the admission. Oxidative stress in COVID-19 leads to a significant increase in the level of primary markers of protein oxidative modifications in the platelets and an increase in the level of products of primary and secondary lipid peroxidation markers in the platelets. A direct correlation between the products of lipid peroxidation and protein oxidative modifications in the platelets and their aggregation has been found. CONCLUSIONS: The following study deepens the knowledge of the status of oxidative stress in SARS-CoV-2 infection, confirming its important role in the pathogenesis of COVID-19. The growth of protein oxidative modifications and lipid peroxidation products in patients with severe COVID-19-associated pneumonia in the course of the disease may be one of the causes of platelet dysfunction and, as a result, lead to lethal thrombotic complications.