Diagnostic Value of Natural Killer Cells, CD56+ CD16+ Natural Killer Cells, NLRP3, and Lactate Dehydrogenase in Severe/Critical COVID-19: A Prospective Longitudinal Study According to the Severe/Critical COVID-19 Definitions

Viral Immunol. 2022 Nov;35(9):616-628. doi: 10.1089/vim.2022.0060. Epub 2022 Sep 13.

Abstract

Innate immunity, as the first line of defense of our immune system, plays a crucial role in defending against SARS-CoV-2 infection and also its immunopathogenesis. We aim to investigate the immune status of natural killer (NK) cells, natural killer T (NKT) cells, and NLRP3 gene expression in COVID-19 patient blood samples. The immunophenotype of NK cell subsets and NKT cells was detected by flow cytometry and the expression of NLRP3 gene assessed by reverse transcriptase real-time polymerase chain reaction in 44 COVID-19 patients and 20 healthy individuals. The percentage of most of NK cell subpopulation and NKT cells was significantly decreased in COVID-19 patients. The percentage of CD56dim CD16- NK cell subsets, and NLRP3 gene expression increased. The percentage of total NK cells, CD56+ CD16+ NK cells, and NLRP3 gene expression had acceptable sensitivity and specificity for assisting diagnosis of severe/critical COVID-19. O2 saturation% and lactate dehydrogenase levels showed valuable diagnostic value to identify critical cases. The declined NK and NKT cells in COVID-19 patients and enhanced NLRP3 gene expression were associated with disease severity. Total NK cells, CD56+ CD16+ NK cells, and NLRP3 gene expression might be used as meaningful indicators for assisting diagnosis of severe/critical COVID-19.

Keywords: COVID-19; NK cell; NKT cells; NLRP3.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CD56 Antigen / metabolism
  • COVID-19* / diagnosis
  • Humans
  • Killer Cells, Natural
  • L-Lactate Dehydrogenase / metabolism
  • Longitudinal Studies
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • Prospective Studies
  • SARS-CoV-2

Substances

  • CD56 Antigen
  • L-Lactate Dehydrogenase
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • FCGR3B protein, human