Researchers have found antibodies in dead people that cause damage to the walls of blood vessels.
Immune response to COVID-19, which damages blood vessels in the brain, may be responsible for 'long COVID' symptoms, according to study based on low case counts and published Tuesday by American researchers.
The brains of nine people who died soon after contracting COVID-19 were studied for this article published in the journal Brain.
The team of researchers from the American Institutes of Health (NIH) did not detect traces of virus in the brain but, conversely, antibodies, causing damage to the walls of the vessels blood which cause inflammation in particular.
This discovery could explain some of the lasting effects of COVID-19, such as migraines, chronic fatigue, loss of taste and smell, sleep problems or even the feeling of brain fog, a state of fatigue intellectual.
It could also open up avenues for future treatments.
Patients often develop neurological complications with COVID-19, but the associated pathophysiological process is not well understood, Avindra Nath, the study's first author, explained in a press release.
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“We had already shown the damage to blood vessels on the brains of patients during autopsies, but we did not understand what caused this.
— Avindra Nath, first author of the study
I think with this article we have new insights into this process, a- he added.
The brains of the nine patients, aged 24 to 73, were compared with 10 others from a control group. Here, researchers observed neuronal inflammation and the immune response.
Scientists found that antibodies produced in response to COVID-19 targeted – for mistake – the cells that make up the blood-brain barrier, a structure that surrounds blood vessels in the brain and tries to block foreign substances.
The breakdown thus caused can in turn lead to protein leaks, bleeding and blood clots, which increases the risk of stroke.
A leakage can also trigger an immune response to repair damaged cells, which causes inflammation.
The biological functioning of these affected parts of the brain is thus disrupted.
“It is entirely possible that the same immune response affects patients with "Long COVID", causing brain injury.
—Avindra Nath, first author of the study
These findings therefore have very important therapeutic implications, he says.
Treatment for these forms of “long COVID” could, for example, limit the production of the antibodies that cause brain damage.