Evaluation of changes in natural killer cells (NK cells) in patients with coronavirus 2019 admitted to the intensive care unit of Imam Reza Hospital in Tabriz and its comparison with healthy controls

Abstract

The first barrier of the immune system in dealing with infections, including viral agents, are innate immune responses, including natural killer cells (NK cells). On the other hand, the imbalance between the expression of inhibitory and activatory genes can be effective in the pathogenesis of covid-19 through the effect on NK cell activity. The aim of this study is to evaluation of changes in natural killer cells in patients with coronavirus 2019 admitted to the intensive care unit of Imam Reza Hospital in Tabriz and its comparison with healthy controls. Materials and Methods: This research was a case-control study and the target population was patients with covid-19 infection hospitalized in the Intensive Unit Care of Imam Reza Hospital in Tabriz and healthy people from this area as a control group in 2020 was 30 people each. The sampling method was simple random. At the beginning of the study, information, symptoms and clinical conditions of the patients were recorded. In order to conduct the study, heparinized blood was taken from sick and healthy people, and Peripheral Blood Mononuclear Cells (PBMC) were separated using Faycol 1.077 and density gradient centrifugation. The amount of micro RNAs in peripheral blood PBMCs was also investigated using Quantitative PCR technique. Results: In this study, All variables of IL-1β (P-value=0.001), IL-6 (P-value=0.001), TNF-α (P-value<0.001) and C5a (P-value=0.002) in the case group were significantly more than the control group studied. Also, all variables of NK cells and NK cytotoxicity in the case group were significantly lower than the control group studied (P-value<0.001). Among the genes of inhibitory receptors, all receptors genes of KIR2DL1 (P-value=0.006), KIR2DL2 (P-value=0.008), KIR2DL3 (P-value=0.01) and NKG2A (P-value=0.004) in the case group were significantly more than the control group studied; On the other hand, among the genes of activatory receptors, all receptors genes of KIR2DS1 (P-value=0.009), KIR2DS4 (P-value=0.026) and NKG2C (P-value=0.015) in the case group were significantly lower than the control group studied.