The immune response to Covid-19, which is involved in brain damage, may be responsible for the symptoms of long Covid.
- Some patients had died suddenly with minimal respiratory impairment.
- In people with long Covid, the virus would lodge in the intestines.
“The mechanisms by which SARS-CoV-2 leads to acute and long-term neurological manifestations remain unclear. We wanted to characterize the neuropathological changes in patients with the disease and determine the underlying pathophysiological mechanisms.” This is what researchers from the American Institutes of Health (NIH) wrote in a study published in the journal Brain the 5 of July.
Damaged brain blood vessels
As part of this work, the scientists examined the brains of nine adults, aged 24 to 73, who died during the first wave of the Covid-19 epidemic. All the patients had died shortly after suffering from the infection, which was confirmed by post-mortem tests. “A descriptive analysis of pathological changes and quantitative analyzes of infiltrates (a pathological infiltration of a tissue by cells) and vascular changes were performed”, the authors said.
According to the results, no trace of coronavirus was identified in the brains of the patients. On the other hand, antibodies, produced by the body in response to Covid-19, have damaged the blood vessels of the brain, which has caused inflammation in particular. According to the researchers, this immune response to the virus could be the cause of the symptoms of long Covid, such as intense fatigue, taste and smell disorders, pain or sleep disturbances.
Endothelial cells are targeted
The team then compared the brains of the nine dead people to those of ten people in a control group. The objective was to analyze the immune response and neuronal inflammation. According to the study, the ability of antibodies to mistakenly destroy endothelial cells, which make up the blood-brain barrier, is “the most likely initiating event that leads to vascular leakage, platelet aggregation, neuroinflammation and neuronal damage. Therapeutic modalities directed against immune complexes should be considered”, can we read in the conclusions of the research.
