The causal effect of natural killer cells on COVID-19 infection, hospitalization and severity

BackgroundRecent studies have suggested that alterations in natural killer (NK) cell function may contribute to the development of COVID-19. Additionally, dysregulated NK cells may increase susceptibility to COVID-19 and affect the severity of the infection.PurposeThis study aimed to explore the causal relationship between NK cell-related immune traits and the risk of COVID-19 infection.MethodsA two-sample Mendelian randomization (MR) analysis was conducted to explore the causal relationship between NK cell-related immune traits and COVID-19. Exposure and outcome data were analyzed using the two-sample Mendelian Randomization (MR) method.ResultsThe results of the study suggest that there is a causal relationship between the absolute number of NK cells in COVID-19 infection and the risk of severe illness. The results also demonstrated that the morphological parameters are not causally related to COVID-19 infection but were causally related to COVID-19 hospitalization and COVID-19 severity.ConclusionThis finding has important implications for our understanding of the pathophysiology of COVID-19 and the development of future therapies and interventions for this disease.