Major reduction of NKT cells in patients with severe COVID-19 pneumonia

Clin Immunol. 2021 Jan:222:108630. doi: 10.1016/j.clim.2020.108630. Epub 2020 Nov 13.

Abstract

Background: NK cells seem to be mainly involved in COVID-19 pneumonia. Little is known about NKT cells which represent a bridge between innate and adaptive immunity.

Methods: We characterized peripheral blood T, NK and NKT cells in 45 patients with COVID-19 pneumonia (COVID-19 subjects) and 19 healthy donors (HDs). According to the severity of the disease, we stratified COVID-19 subjects into severe and non-severe groups.

Results: Compared to HDs, COVID-19 subjects showed higher percentages of NK CD57+ and CD56dim NK cells and lower percentages of NKT and CD56bright cells. In the severe group we found a significantly lower percentage of NKT cells. In a multiple logistic regression analysis, NKT cell was independently associated with the severity of the disease.

Conclusions: The low percentage of NKT cells in peripheral blood of COVID-19 subjects and the independent association with the severity of the disease suggests a potential role of this subset.

Keywords: CD56bright; CD56dim; Flow Cytometry; Immunophenotyping analysis; SARS-CoV-2.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antigens, CD / genetics
  • Antigens, CD / metabolism
  • COVID-19 / pathology*
  • Female
  • Gene Expression Regulation
  • Humans
  • Male
  • Middle Aged
  • Natural Killer T-Cells / classification
  • Natural Killer T-Cells / metabolism
  • Natural Killer T-Cells / physiology*
  • SARS-CoV-2*

Substances

  • Antigens, CD