They found out why some people do not recover their sense of smell after COVID-19.

American scientists have found that some people do not return the feeling smell after infection SARS-CoV-2because the virus causes a continuous immune attack that reduces the number of olfactory nerve cells.

Conclusion published in the journal Science Translational Medicinefinally explains how a problem arises that affects millions of people around the world.

The study also sheds light on possible underlying causes of other long-term symptoms of COVID-19, such as general fatigue, shortness of breath or lack of concentration, which the researchers believe may be caused by similar biological mechanisms.

“One of the first symptoms commonly associated with Covid-19 infection is loss of smell. Fortunately, many people recover their sense of smell after a week or two, while others do not,” he says. Bradley Goldsteinlead author of the study and neuroscience researcher at Duke University (North Carolina, USA).

“We wanted to better understand why some people have a permanent loss of smell for months or years after infection,” he explains.

Together with scientists from Harvard and the University of California, San Diego, Duke’s team analyzed samples of olfactory epithelium from 24 biopsies, including nine patients with permanent loss of olfactory epithelium. smell.

The analysis showed widespread infiltration of T cells involved in the inflammatory response in the olfactory epithelium, tissue in the nose that contains nerve cells for smell.

“Amazing Results”

The inflammatory process persisted after infection, and the number of olfactory sensory neurons decreased, possibly due to damage to delicate tissue caused by persistent inflammation.

For Goldstein, “the results are amazing. It almost looks like some kind of autoimmune process in the nose.”

Goldstein believes that knowing which areas are damaged and which cell types are involved is the key to starting to develop treatments.

In addition, the team finds it reassuring that neurons appear to retain some ability to recover even after an immune attack.

“We hope that modulating the abnormal immune response or repair processes in the nose in these patients may help to at least partially restore the sense of smell,” he says.

In his opinion, the results of this study may also be useful for further research on other long-term symptoms of COVID-19, which may be caused by similar inflammatory processes. (EFE)