Assessing molecular genetic and immunological predictors of COVID-19 course in healthcare worker risk group

Relevance. Studying features of innate and adaptive mechanisms of immune response in medical workers (MW), the most vulnerable social group with a high risk of infection, is an urgent research task. The aim of the study: Comprehensive study of innate and adaptive immune mechanisms and analyzing relationships between clinically significant polymorphisms (SNPs) in TLR2, TLR4 genes, TLR2 expression level on peripheral blood monocytes, peripheral blood cytokine profile (IL-1β, IL-10, IL-6, IFNγ, platelet activation marker) and SARS-CoV-2-specific humoral immune response in medical workers (MW) at a temporary infectious disease hospital in early and late COVID-19 convalescence. Materials and methods. immunologic, cytofluorimetric and molecular-genetic research methods were applied. Adaptive immune response in medical workers — COVID-19 convalescent subjects. Results. Early post-COVID-19 convalescence period in MW was linked to higher TLR2 monocyte expression; the mean fluorescence intensity was significantly elevated by 1.5-fold compared to control group. Late convalescence period (7 months post-COVID-19) was characterized by lowered serum IFNγ level. A decline in IFNγ production was significant: decreased by 82-fold in MR that was markedly stronger compared to control group (59 times). The imbalance of cytokines controlling antiviral innate and adaptive immune response was revealed in MW with identified combination of polymorphisms rs5743708 and rs4986790 in TLR2, TLR4 genes with the rate not exceeding 6.7%. It was found that 7 months after COVID-19 there was a markedly decreased IFNγ, IL-1β and IL-10 levels. The studies indicate both altered innate and adaptive immune mechanisms and a need to optimize therapeutic and prophylactic measures aimed at increasing patient-intrinsic resistance, protection of respiratory tract mucosal barriers and identification of genetic predictors of defects in innate and adaptive immune response in medical workers — COVID-19 convalescent subjects.