Endothelial Dysfunction in Covid-19

Endothelial Dysfunction and Oxidative Stress in ICU and Non-ICU Covid-19 Patients With Hypoxemic Respiratory Failure

SARS-CoV-2 targets endothelial cells via the angiotensin-converting enzyme 2 receptor. The specific impact of the resulting endothelial injury is currently unknown but may contribute to the pro-coagulant state classically described during Covid-19 disease and commonly associated with an exacerbated activation of the renin-angiotensin-aldosterone system.

We prospectively compared clinical and biological parameters in ICU- and non-ICU-admitted Covid-19 patients, ICU-admitted patients with septic shock unrelated to Covid-19 and matched control subjects.

Primary hemostasis and coagulation parameters and endothelial biomarkers are measured. Activation of the renin-angiotensin-aldosterone system is monitored through measurements of plasma renin, angiotensin II, aldosterone, and serum soluble angiotensin-converting enzyme 2. Vascular oxidative status is assessed by measuring plasma lipids peroxides. Neutrophilic polymorphonuclear activation is assessed by measuring plasma levels of Triggering receptor expressed on myeloid cells-1. Vascular nitric oxide bioavailability is measured by quantification of the concentration of heme-nitrosylated hemoglobin (HbNO) in venous erythrocytes using Electron Paramagnetic Resonance spectroscopy. Structural abnormalities of vascular endothelial cells were analyzed by Transmission Electron- and Scanning Electron Microscopy.

Inclusion Criteria:

• positive result on a reverse-transcriptase-polymerase chain reaction testing performed on nasopharyngeal swab at hospital admission

Exclusion Criteria:

• ICU admission more than five days after admission on a general ward,
• concomitant bacterial infection
• older than 75 years
• cirrhosis