it’s a It is possible that the reason for the inability of some people to regain their sense of smell after infection with the Covid virus is related to a persistent immune attack on olfactory neurons and the consequent decrease in the number of these cells, says a team of scientists in the United States.

Read also: After all, the loss of the sense of taste and smell is good news for people with Covid

This is the conclusion of a study published in the scientific journal Translational Medicine Sciences And it was carried out by researchers from Duke Health, an organization located at Duke University in the United States.

The investigation focused on a loss of smell, but it may also help understand possible causes for other prolonged Covid symptoms – including general fatigue, shortness of breath and ‘mental fog’ – that could be caused by similar biological mechanisms.

To conduct the study, the researchers analyzed olfactory epithelial samples collected through 24 biopsies, which included nine patients with long-term loss of their sense of smell due to Covid-19.

With this analysis, it was possible to find “a widespread infiltration of T cells, involved in the inflammatory response, in the olfactory epithelium, the nasal tissue where olfactory neurons reside,” the scientists explained in a statement. Moreover, this unique inflammatory process persisted despite having no detectable levels of SARS-CoV-2.

Moreover, the number of olfactory sensory neurons was decreasing, “possibly due to the thinning tissue damage caused by this inflammation.”

“We hope that modulating the abnormal immune response or repair processes in these patients’ noses will help, at least in part, restore their sense of smell,” said Bradley Goldstein, lead author of the study.

Read also: The long-term risk of contracting Covid is higher for these people, the study says