Upregulation of pulmonary tissue factor, loss of thrombomodulin and immunothrombosis in SARS-CoV-2 infection

Ivo M B Francischetti; Kevin Toomer; Yifan Zhang; Jayesh Jani; Zishan Siddiqui; Daniel J Brotman; Jody E Hooper; Thomas S Kickler

doi:10.1016/j.eclinm.2021.101069

Upregulation of pulmonary tissue factor, loss of thrombomodulin and immunothrombosis in SARS-CoV-2 infection

EClinicalMedicine. 2021 Sep:39:101069. doi: 10.1016/j.eclinm.2021.101069. Epub 2021 Aug 6.

Authors

Ivo M B Francischetti¹, Kevin Toomer¹, Yifan Zhang², Jayesh Jani¹, Zishan Siddiqui³, Daniel J Brotman³, Jody E Hooper¹, Thomas S Kickler¹

Affiliations

¹ Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
² Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States.
³ Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States.

Abstract

Background: SARS-CoV-2 infection is associated with thrombotic and microvascular complications. The cause of coagulopathy in the disease is incompletely understood.

Methods: A single-center cross-sectional study including 66 adult COVID-19 patients (40 moderate, 26 severe disease), and 9 controls, performed between 04/2020 and 10/2020. Markers of coagulation, endothelial cell function [angiopoietin-1,-2, P-selectin, von Willebrand Factor Antigen (WF:Ag), von Willebrand Factor Ristocetin Cofactor, ADAMTS13, thrombomodulin, soluble Endothelial cell Protein C Receptor (sEPCR), Tissue Factor Pathway Inhibitor], neutrophil activation (elastase, citrullinated histones) and fibrinolysis (tissue-type plasminogen activator, plasminogen activator inhibitor-1) were evaluated using ELISA. Tissue Factor (TF) was estimated by antithrombin-FVIIa complex (AT/FVIIa) and microparticles-TF (MP-TF). We correlated each marker and determined its association with severity. Expression of pulmonary TF, thrombomodulin and EPCR was determined by immunohistochemistry in 9 autopsies.

Findings: Comorbidities were frequent in both groups, with older age associated with severe disease. All patients were on prophylactic anticoagulants. Three patients (4.5%) developed pulmonary embolism. Mortality was 7.5%. Patients presented with mild alterations in the coagulogram (compensated state). Biomarkers of endothelial cell, neutrophil activation and fibrinolysis were elevated in severe vs moderate disease; AT/FVIIa and MP-TF levels were higher in severe patients. Logistic regression revealed an association of D-dimers, angiopoietin-1, vWF:Ag, thrombomodulin, white blood cells, absolute neutrophil count (ANC) and hemoglobin levels with severity, with ANC and vWF:Ag identified as independent factors. Notably, postmortem specimens demonstrated epithelial expression of TF in the lung of fatal COVID-19 cases with loss of thrombomodulin staining, implying in a shift towards a procoagulant state.

Interpretation: Coagulation dysregulation has multifactorial etiology in SARS-Cov-2 infection. Upregulation of pulmonary TF with loss of thrombomodulin emerge as a potential link to immunothrombosis, and therapeutic targets in the disease.

Funding: John Hopkins University School of Medicine.

Keywords: ADAMTS13, a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13; ALC, absolute lymphocyte count; ALI, Acute Lung Injury; AMC, absolute monocyte count; ANC, absolute neutrophil count; AT/VIIa, antithrombin-FVIIa complex; Coagulation; ELISA, enzyme-linked immunosorbent assay; Hb, hemoglobin; Hemostasis; ICU, intensive care unit; Ixolaris; LMWH, low molecular weight heparin; MP-TF, Microparticles-Tissue Factor; PAI-1, plasminogen activator inhibitor-1; PAR, protease-activated receptor; TF, Tissue Factor; TFPI, Tissue Factor Pathway Inhibitor; Thrombosis; WBC, white blood cells; sEPCR, soluble Endothelial cell Protein C Receptor; t-PA, tissue-type plasminogen activator; vWF, von Willebrand Factor; vWF:Ag, von Willebrand Factor Antigen; vWF:RCo, von Willebrand Factor Ristocetin Cofactor.