Increased Serum Levels of sCD14 and sCD163 Indicate a Preponderant Role for Monocytes in COVID-19 Immunopathology

Front Immunol. 2020 Sep 23:11:560381. doi: 10.3389/fimmu.2020.560381. eCollection 2020.


Background: Emerging evidence indicates a potential role for monocytes in COVID-19 immunopathology. We investigated two soluble markers of monocyte activation, sCD14 and sCD163, in COVID-19 patients, with the aim of characterizing their potential role in monocyte-macrophage disease immunopathology. To the best of our knowledge, this is the first study of its kind.

Methods: Fifty-nine SARS-Cov-2 positive hospitalized patients, classified according to ICU or non-ICU admission requirement, were prospectively recruited and analyzed by ELISA for levels of sCD14 and sCD163, along with other laboratory parameters, and compared to a healthy control group.

Results: sCD14 and sCD163 levels were significantly higher among COVID-19 patients, independently of ICU admission requirement, compared to the control group. We found a significant correlation between sCD14 levels and other inflammatory markers, particularly Interleukin-6, in the non-ICU patients group. sCD163 showed a moderate positive correlation with the time lapsed from admission to sampling, independently of severity group. Treatment with corticoids showed an interference with sCD14 levels, whereas hydroxychloroquine and tocilizumab did not.

Conclusions: Monocyte-macrophage activation markers are increased and correlate with other inflammatory markers in SARS-Cov-2 infection, in association to hospital admission. These data suggest a preponderant role for monocyte-macrophage activation in the development of immunopathology of COVID-19 patients.

Keywords: COVID-19; immunopathology; monocyte; sCD14; sCD163.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenal Cortex Hormones / administration & dosage
  • Adult
  • Aged
  • Antibodies, Monoclonal, Humanized / administration & dosage
  • Antigens, CD* / blood
  • Antigens, CD* / immunology
  • Antigens, Differentiation, Myelomonocytic* / blood
  • Antigens, Differentiation, Myelomonocytic* / immunology
  • Betacoronavirus* / immunology
  • Betacoronavirus* / metabolism
  • COVID-19
  • Coronavirus Infections* / blood
  • Coronavirus Infections* / drug therapy
  • Coronavirus Infections* / immunology
  • Coronavirus Infections* / pathology
  • Female
  • Humans
  • Hydroxychloroquine / administration & dosage
  • Intensive Care Units
  • Interleukin-6 / blood
  • Interleukin-6 / immunology
  • Lipopolysaccharide Receptors* / blood
  • Lipopolysaccharide Receptors* / immunology
  • Macrophage Activation
  • Macrophages / immunology
  • Macrophages / metabolism
  • Macrophages / pathology
  • Male
  • Middle Aged
  • Monocytes / immunology
  • Monocytes / pathology
  • Pandemics*
  • Patient Admission
  • Pneumonia, Viral* / blood
  • Pneumonia, Viral* / drug therapy
  • Pneumonia, Viral* / immunology
  • Pneumonia, Viral* / pathology
  • Receptors, Cell Surface* / blood
  • Receptors, Cell Surface* / immunology
  • SARS-CoV-2
  • Time Factors


  • Adrenal Cortex Hormones
  • Antibodies, Monoclonal, Humanized
  • Antigens, CD
  • Antigens, Differentiation, Myelomonocytic
  • CD14 protein, human
  • CD163 antigen
  • IL6 protein, human
  • Interleukin-6
  • Lipopolysaccharide Receptors
  • Receptors, Cell Surface
  • Hydroxychloroquine
  • tocilizumab