Analysis of the Level of IgG to SARS-CoV-2 Virus and Molecular Markers of Activation of CD25, CD54 (ICAM-1) and CD95 Lymphocytes in the Patients Who were Not Ill with COVID-19, Recovered from COVID-19 and Who had Acute Respiratory Infections. The Results of the Correction of Impaired Immune Homeostasis Using the Multitarget Immunotherapy Drug Mercureid

Abstract

Currently, the researchers have come across a paradox which consists in detecting protective IgG antibodies to SARS-CoV-2 virus only in a subset of patients who have recovered from COVID-19. The other patients, who were in contact with the infected people, have not contracted COVID-19 (there were no symptoms of this illness detected and PCR was negative). Nevertheless, these people have got IgG antibodies to SARS-CoV-2 virus too. It’s also worth pointing out that the presence of IgG to SARS-CoV-2 virus correlates with an altered immune response when infected with seasonal viral diseases; in particular, the ability to produce protective antibodies decreases.

All these factors predetermine different clinical courses of the disease and the consequences of the patient’s post-COVID condition (post-COVID conditions / PCC).

To examine the diverse immune responses of patients, including asymptomatic carriage, a study on 414 patients was conducted. The novelty of the research is the following. For the first time, not only the levels of protective IgG antibody titers to SARS-CoV-2 virus were determined, but also their correlations with lymphocyte activation markers CD25, CD54 (ICAM-1) and CD95 in three groups of patients, namely, people who did not have COVID-19, who recovered from COVID-19 and who had acute respiratory infections, were examined. The research is aimed at both scientific and practical purposes, including the search for new therapeutic options. The possibility of controlling the activation molecules of T-lymphocytes and editing their activity using the multitarget immunotherapy drug Mercureid was studied. The therapeutic efficacy of Mercureid usage was 75.6%.