The reason some people do not fully recover their sense of smell even though some time has passed since the initial infection Covid-19, is an ongoing autoimmune reaction of their body's immune system, which attacks the olfactory nerve cells in the nose, resulting in the reduction of their number and ultimately the inability to restore the sense of smell.
This was announced by scientists from the American universities of Duke, Harvard and California-San Diego, led by associate professor Bradley Goldstein of the Duke Medical Center in North Carolina, who analyzed biopsy samples from the epithelium of the nose of 24 patients and made the relevant publication in medical journal "Science Translational Medicine".
The study sheds light on a problem that afflicts millions of people (at least 5% of all patients with Covid-19), who – after falling ill due to the coronavirus – have not yet recovered their normal sense of smell. The research, while focusing on olfaction, also sheds more light on possible underlying causes for other symptoms of long-term Covid-19, such as generalized fatigue, shortness of breath, brain fog, etc., which are probably triggered by similar autoimmune biological mechanisms.
"Many people who have an altered sense of smell during the acute phase of the virus infection will regain their sense of smell within one to two weeks, but some will not. There is a need to better understand this subgroup of people who continue to have persistent loss of smell for months or even years after being infected with the SARS-CoV-2 coronavirus. "Our findings are striking, as they look like a kind of autoimmune reaction in the nose itself," said Dr. Goldstein.
However, the researchers called it encouraging that, despite the damage to the olfactory neurons, at least some of them seem to partially retain the ability to restore their function gradually. Scientists also hope that, now that they have shed light on the biological mechanism of the damage, they will find new treatments for the problem so that they can restore at least some sense of smell.
Source: ΑΠΕ- ΜΠΕ