Immunothrombosis in COVID-19: Implications of Neutrophil Extracellular Traps

Biomolecules. 2021 May 6;11(5):694. doi: 10.3390/biom11050694.

Abstract

SARS-CoV-2 is a member of the family of coronaviruses associated with severe outbreaks of respiratory diseases in recent decades and is the causative agent of the COVID-19 pandemic. The recognition by and activation of the innate immune response recruits neutrophils, which, through their different mechanisms of action, form extracellular neutrophil traps, playing a role in infection control and trapping viral, bacterial, and fungal etiological agents. However, in patients with COVID-19, activation at the vascular level, combined with other cells and inflammatory mediators, leads to thrombotic events and disseminated intravascular coagulation, thus leading to a series of clinical manifestations in cerebrovascular, cardiac, pulmonary, and kidney disease while promoting severe disease and mortality. Previous studies of hospitalized patients with COVID-19 have shown that elevated levels of markers specific for NETs, such as free DNA, MPO, and H3Cit, are strongly associated with the total neutrophil count; with acute phase reactants that include CRP, D-dimer, lactate dehydrogenase, and interleukin secretion; and with an increased risk of severe COVID-19. This study analyzed the interactions between NETs and the activation pathways involved in immunothrombotic processes in patients with COVID-19.

Keywords: CID; COVID-19; SARS-CoV-2; immunothrombosis; neutrophil extracellular traps.

Publication types

  • Review

MeSH terms

  • Biomarkers / metabolism
  • COVID-19 / immunology
  • COVID-19 / pathology*
  • COVID-19 / virology
  • Complement System Proteins / metabolism
  • Cytokine Release Syndrome / etiology
  • Cytokine Release Syndrome / pathology
  • Disseminated Intravascular Coagulation / etiology
  • Disseminated Intravascular Coagulation / pathology
  • Extracellular Traps / metabolism*
  • Humans
  • Neutrophils / cytology
  • Neutrophils / immunology
  • Neutrophils / metabolism
  • SARS-CoV-2 / isolation & purification
  • Thrombosis / immunology*
  • Thrombosis / metabolism
  • Thrombosis / pathology*

Substances

  • Biomarkers
  • Complement System Proteins