Diagnostic significance of antioxidant protection indicators for assessing the course of post-Covid syndrome

Introduction. An increasing number of reports of long-term negative consequences of COVID-19, characterized by chronic inflammation, tissue hypoxia, oxidative stress, metabolic changes at the level of all body systems, determines the search for criteria for assessing long-term post-Covid syndrome. A high level of information content of saliva as samples for laboratory diagnosis of respiratory syndromes has been shown. The fact that SARS-CoV-2 is present in saliva in high concentrations suggests that saliva studies will provide rapid acquisition of useful information about the pathogenesis of post-Covid syndrome, allows us to identify the most vulnerable areas of metabolic processes and target them in combination with other rehabilitation measures.

Purpose of the study: to evaluate the state of antioxidant protection and indicators of resistance to hypoxia in patients in the post-Covid period 6 monthes after the manifestation of the infectious process caused by SARS-CoV-2, according to biochemical analysis of saliva.

Material and methods. 58 people participated in the study. 28 people

control group, who denied the fact of the disease; 30 people

a comparison group who suffered a new coronavirus infection of moderate severity, confirmed by PCR. The concentrations of pyruvic acid, lactic acid, reduced glutathione, the activity of glutathione reductase, glutathione peroxidase, myeloperoxidase, and ceruloplasmin were determined in saliva.

Results. In the saliva of patients in the post-Covid period, there is a pronounced increase in myeloperoxidase activity, which indicates a chronic inflammatory process. An increase in ceruloplasmin activity indicates a deficiency of iron and copper, which are necessary for oxidative phosphorylation and cellular respiration. A change in the ratio of lactate to pyruvate indicates the accumulation of NADH2, so to change the Redox status of the body, characteristic of hypoxic conditions. A decrease in the activity of enzymes of the glutathione system was noted, which reflects the inhibition of the processes of AOD and mitochondrial oxidation.

Conclusion. A set of indicators characterizing AOD, the ratio of aerobic and anaerobic processes, iron and copper transport, provides information about the peculiarities of the course of the post-Covid syndrome, which substantiates the correction paths associated with restoring glutathione levels, indicators of iron and copper metabolism and increasing resistance to hypoxic processes.