Dados do Trabalho

Título

Dysfunction Profile of NK Cells Might Develop Worst Outcomes in Covid-19 Patients Especially in Elderly Inviduals

Introdução

COVID-19 is a systemic disease caused by SARS-CoV-2 virus. It is known that the individual immune response plays a critical role in the evolution of disease. In this context, a cell population that seems to play an important role in COVID-19 are NK cells, since they act in the response against viruses and tumor cells, inducing death via apoptosis.

Objetivo(s)

To evaluate the phenotypic and functional profile of NK cells in patients hospitalized in the ward and ICU with COVID-19, as well as the impact of aging on the profile of these cells.

Material e Métodos

10 mL of peripheral blood were collected from 49 patients (18-92 years old) with a positive diagnosis for SARS-CoV-2 from Hospital Risoleta Tolentino Neves, in the period from 07/2020 to 03/2021, and 12 healthy volunteers with a negative diagnosis for COVID-19. We evaluated the phenotypic and functional ex vivo profile of NK cells after staining with monoclonal antibodies for surface (CD3, CD56, CD161, CD38, NKG2D and CD107A).

Resultados e Conclusão

The results showed the COVID-19 patients displayed an altered profile of NK cells, when compared to the control group. The data analysis revealed a decrease in circulating percentage and increase expression of CD107A+ and NKG2D+, in the CD56+CD161+ population, related to the activation and cytotoxic activity of NK cells. It was also observed that the expression of CD161+CD38+, associated with the functional activity of these cells, was decreased in patients who died when compared to individuals who were discharged from the hospital. In addition, when the patients were categorized by age group, a progressive decrease of CD56+CD161+ NK cells, as well as decreased expression of CD38+ and NKG2D+ activation receptors were observed in individuals >69 years. Altogether these results suggest that the decrease in both the percentage and phenotype expression associated with cytotoxicity of NK cells could be associated with the negative outcome, being one of the factors responsible and associated with death, mainly, in those individuals over 60 years.

Palavras-chave

COVID-19; Imunopathology; NK cells; Elderly, Flow Cytometry.