FEATURES OF CLINICAL AND LABORATORY PARAMETERS IN PATIENTS WITH SARS-COV-2 INFECTION DEPENDING ON THE RESULTS OF SEROLOGICAL DIAGNOSIS

Abstract

To date, over 270 million people have been ill with COVID-19 and more than 2 million have died. Tens of thousands of new cases of the disease are still registered in the world every day, so the assessment of the methods for diagnosing SARS-CoV-2 associated pathology remains highly relevant. The aim of the study was to evaluate the variability of clinical and laboratory parameters in patients with SARS-CoV-2 infection depending on the results of serological diagnostics. Material and methods. 170 patients (88 women, 82 men aged 23 to 90 years) diagnosed with community-acquired interstitial pneumonia following SARS-CoV-2 infection were examined in accordance with the clinical protocol, in 80 of them the blood levels of IL-1β, IL-6, IL-18, CXCL8, and interferon-α were determined. Results. It was found that only in 34.09% of cases a negative PCR result for the presence of the genetic material of SARS-CoV-2 viruses in patients diagnosed with interstitial pneumonia coincided with a negative result of testing for IgG and/or IgM to the viral antigen. A positive PCR result was confirmed by the presence of elevated levels of antibodies in 64.29% of cases. In PCR-positive patients, stage II III respiratory failure was determined significantly more often than in PCR-negative ones (in 40.28% and 16.32% of cases, respectively, p<0.01), and their condition was more often regarded as severe and extremely severe (in 31.94% and 10.0% of cases, respectively, p<0.05). The level of antibodies was associated with the severity of the immune response to a viral infection: the volume of lung damage, the blood level of the pro-inflammatory cytokine IL-18, acute phase inflammation proteins, and the activity of intracellular enzymes were significantly higher in patients with elevated levels of IgG and/or IgM than in patients with negative results of these tests. Conclusions. The determining of IgM and IgG specific to the Spike antigen of the SARS-CoV-2 virus does not duplicate, but complements the molecular genetic study. PCR helps to detect the presence of the genetic material of the virus. Detection of the level of antibodies can be used to make a conclusion about the intensity and stage of the immune response to a viral infection.