Blood fibrocytes are associated with severity and prognosis in COVID-19 pneumonia.

Abstract

Increased blood fibrocytes are associated with a poor prognosis in fibrotic lung diseases. We aimed to determine whether the percentage of circulating fibrocytes could be predictive of severity and prognosis during coronavirus disease 2019 (COVID-19) pneumonia. Blood fibrocytes were quantified by flow cytometry as CD45+/CD15-/CD34+/collagen-1+ cells in patients hospitalized for COVID-19 pneumonia. In a subgroup of patients admitted in an intensive care unit (ICU), fibrocytes were quantified in blood and bronchoalveolar lavage (BAL). Serum amyloid P (SAP), transforming growth factor-β1 (TGF-β1), CXCL12, CCL2, and FGF2 concentrations were measured. We included 57 patients in the hospitalized group (median age = 59 yr [23-87]) and 16 individuals as healthy controls. The median percentage of circulating fibrocytes was higher in the patients compared with the controls (3.6% [0.2-9.2] vs. 2.1% [0.9-5.1], P = 0.04). Blood fibrocyte count was lower in the six patients who died compared with the survivors (1.6% [0.2-4.4] vs. 3.7% [0.6-9.2], P = 0.02). Initial fibrocyte count was higher in patients showing a complete lung computed tomography (CT) resolution at 3 mo. Circulating fibrocyte count was decreased in the ICU group (0.8% [0.1-2.0]), whereas BAL fibrocyte count was 6.7% (2.2-15.4). Serum SAP and TGF-β1 concentrations were increased in hospitalized patients. SAP was also increased in ICU patients. CXCL12 and CCL2 were increased in ICU patients and negatively correlated with circulating fibrocyte count. We conclude that circulating fibrocytes were increased in patients hospitalized for COVID-19 pneumonia, and a lower fibrocyte count was associated with an increased risk of death and a slower resolution of lung CT opacities.

• Authors: Mada Ghanem, Méline Homps-Legrand, Marc Garnier, Lise Morer, Tiphaine Goletto, Justine Frija-Masson, Paul-Henri Wicky, Pierre Jaquet, Catherine Bancal, Margarita Hurtado-Nedelec, Luc de Chaisemartin, Madeleine Jaillet, Arnaud Mailleux, Christophe Quesnel, Nicolas Poté, Marie-Pierre Debray, Etienne de Montmollin, Catherine Neukirch, Raphael Borie, Camille Taillé, Bruno Crestani, French COVID Cohort Study Group
• Journal: American journal of physiology. Lung cellular and molecular physiology (Am J Physiol Lung Cell Mol Physiol) Vol. 321 Issue 5 Pg. L847-L858 (11 01 2021) ISSN: 1522-1504 [Electronic] United States
• PMID: 34496650 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Antigens, CD
• Cytokines
• Serum Amyloid A Protein

Topics

• Adult
• Aged
• Aged, 80 and over
• Antigens, CD (blood)
• Blood Cell Count
• Blood Cells (metabolism)
• COVID-19 (blood, diagnosis, diagnostic imaging)
• Cytokines (blood)
• Female
• Humans
• Male
• Middle Aged
• Prognosis
• SARS-CoV-2 (metabolism)
• Serum Amyloid A Protein (metabolism)
• Severity of Illness Index
• Tomography, X-Ray Computed