Data-Driven Analysis of COVID-19 Reveals Persistent Immune Abnormalities in Convalescent Severe Individuals

Front Immunol. 2021 Nov 19;12:710217. doi: 10.3389/fimmu.2021.710217. eCollection 2021.

Abstract

Severe SARS-CoV-2 infection can trigger uncontrolled innate and adaptive immune responses, which are commonly associated with lymphopenia and increased neutrophil counts. However, whether the immune abnormalities observed in mild to severely infected patients persist into convalescence remains unclear. Herein, comparisons were drawn between the immune responses of COVID-19 infected and convalescent adults. Strikingly, survivors of severe COVID-19 had decreased proportions of NKT and Vδ2 T cells, and increased proportions of low-density neutrophils, IgA+/CD86+/CD123+ non-classical monocytes and hyperactivated HLADR+CD38+ CD8+ T cells, and elevated levels of pro-inflammatory cytokines such as hepatocyte growth factor and vascular endothelial growth factor A, long after virus clearance. Our study suggests potential immune correlates of "long COVID-19", and defines key cells and cytokines that delineate true and quasi-convalescent states.

Keywords: COVID-19; SARS – CoV – 2; active infection; cytokine profile; immune recovery; immunophenotyping; inflammation; severity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • COVID-19 / complications
  • COVID-19 / immunology*
  • Cohort Studies
  • Convalescence
  • Female
  • Humans
  • Male
  • Middle Aged
  • SARS-CoV-2 / immunology*

Supplementary concepts

  • post-acute COVID-19 syndrome