By analyzing the tissues of patients who died of Covid-19, researchers have found that the disease directly causes inflammation of blood vessels, which can lead to the failure of vital organs, even death.
While Covid-19 was initially considered an exclusively respiratory disease (the lung is undoubtedly the most seriously affected organ), it has been appearing for a some time that many affected patients do not die from lung failure, but from cardiovascular problems or multi-organ failure.
Arrested, Professor Zsuzsanna Varga and her team, from the University Hospital of Zurich (Switzerland), recently examined under the microscope tissue samples from three deceased patients (two men 69 and 71 years old, and a 58-year-old woman). They then found that the inflammation affected the endothelium . Details of their study were published in The Lancet journal. .
Endothelium is the innermost layer of blood vessels , the one in contact with the blood. It is, in a way, a protective shield for the vessels present throughout the cardiovascular system. If this function is disturbed, then circulatory disturbances in the organs and tissues of the body can then occur, which in turn leads to cell death – and thus the death of the organs and tissues concerned.
We already know that, in order to infect the host, the novel coronavirus SARS-CoV-2 binds to a cell surface protein, the enzyme converting enzyme receptor. angiotensin 2 (ACE2). What the researchers can now deduce, in view of this new work, is that the virus therefore attacks the immune system not through the lungs, as previously suggested, but directly through the ACE2 receptors. present in the endothelium, which thus loses its protective function.
"Affected patients may suffer not only from inflammation of the lungs, but also from systemic inflammation of blood vessels which can damage the heart, brain, the lungs, the kidneys, but also the intestine” , sums up Franck Ruschitzka, co-author of the study, who heads the hospital's cardiology department.
Patients with high blood pressure, diabetes , heart failure or coronary heart disease have in common a restricted endothelial function . This would therefore explain why they appear much more fragile in the face of the disease.
For Frank Ruschitzka, the results of this work also imply the need to combat the multiplication of the virus, but at the same time to protect and stabilize the vascular system of patients.
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