Characteristics of Peripheral Lymphocyte Subset Alteration in COVID-19 Pneumonia

J Infect Dis. 2020 May 11;221(11):1762-1769. doi: 10.1093/infdis/jiaa150.


Background: In December 2019, novel coronavirus (SARS-CoV-2) pneumonia (COVID-19) was reported in Wuhan and has since rapidly spread throughout China. We aimed to clarify the characteristics and clinical significance of peripheral lymphocyte subset alteration in COVID-19.

Methods: The levels of peripheral lymphocyte subsets were measured by flow cytometry in 60 hospitalized COVID-19 patients before and after treatment, and their association with clinical characteristics and treatment efficacy was analyzed.

Results: Total lymphocytes, CD4+ T cells, CD8+ T cells, B cells, and natural killer (NK) cells decreased in COVID-19 patients, and severe cases had a lower level than mild cases. The subsets showed a significant association with inflammatory status in COVID-19, especially CD8+ T cells and CD4+/CD8+ ratio. After treatment, 37 patients (67%) showed clinical response, with an increase in CD8+ T cells and B cells. No significant change in any subset was detected in nonresponsive cases. In multivariate analysis, posttreatment decrease in CD8+ T cells and B cells and increase in CD4+/CD8+ ratio were indicated as independent predictors of poor efficacy.

Conclusions: Peripheral lymphocyte subset alteration was associated with clinical characteristics and treatment efficacy of COVID-19. CD8+ T cells tended to be an independent predictor for COVID-19 severity and treatment efficacy.

Keywords: COVID-19; lymphocyte subset; pneumonia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Betacoronavirus / isolation & purification
  • COVID-19
  • China
  • Coronavirus Infections / complications*
  • Coronavirus Infections / diagnosis
  • Coronavirus Infections / physiopathology*
  • Coronavirus Infections / therapy
  • Female
  • Flow Cytometry
  • Humans
  • Lymphocyte Count
  • Lymphocyte Subsets* / immunology
  • Male
  • Middle Aged
  • Pandemics
  • Pneumonia / diagnosis
  • Pneumonia / etiology*
  • Pneumonia / physiopathology*
  • Pneumonia / therapy
  • Pneumonia, Viral / complications*
  • Pneumonia, Viral / diagnosis
  • Pneumonia, Viral / physiopathology*
  • Pneumonia, Viral / therapy
  • Prognosis
  • SARS-CoV-2
  • Treatment Outcome