Regained smell sense after COVID-19? Here's what a study revealed
According to researchers at Duke University in the United States, the failure of some patients to recover their smell sense after COVID-19 is linked to a persistent immunological assault on olfactory nerve cells and a corresponding decrease in the number of those cells.
FollowThe reason some patients do not recover their smell sense post-COVID-19 is linked to a persistent immunological assault on olfactory nerve cells and a corresponding decrease in the number of those cells, according to researchers at Duke University in the United States.
Olfactory nerve cells are linked to our ability to distinguish between scents and smells.
According to the study, the journal Science Translational Medicine findings provided crucial insight into a complex problem that has plagued millions who have not fully recovered their sense of smell after COVID-19.
The finding shed light on the loss of smell and the possible underlying reasons for other lengthy COVID-19 symptoms, including widespread fatigue, shortness of breath, and cognitive fog, which could be included by comparable biological mechanisms.
Senior author Bradley Goldstein of Duke University said, "Loss of smell is one of the first symptoms traditionally related to COVID-19 infection."
According to Goldstein, many people, fortunately, have an altered sense of smell while in the acute phase of viral infection and will recover within the next one or two weeks, but some don't.
"We need to understand why this fraction of persons has chronic smell loss for months to years after being infected with SARS-CoV-2," Goldstein added.
In the finding, Goldstein and colleagues at Duke, Harvard, and the University of California-San Diego examined olfactory epithelial samples from 24 biopsies, including nine patients with long-term smell loss after COVID-19.
The olfactory epithelium, the tissue in the nose where smell nerve cells are located, was found to have broad infiltration of T-cells involved in an inflammatory response using this biopsy-based technique. According to the study, this distinct inflammatory process continued despite the absence of measurable SARS-CoV-2 levels.
According to the study, the number of olfactory sensory neurons was also reduced, presumably due to damage to the sensitive tissue from continuous inflammation.
"The findings are startling," Goldstein continued. "It's similar to an autoimmune-like condition in the nose."
According to Goldstein, knowing what sites are damaged and what cell types are involved is a critical step towards beginning to design treatments. He added that the researchers were encouraged that neurons appeared to maintain some ability to repair even after the long-term immune onslaught.
"We are hopeful that controlling the abnormal immune response or recovery processes within these patients' noses could help to at least partially restore a sense of smell," Goldstein said, stressing that this study was presently underway in his lab.
He added that the findings of this study should help guide future research into other long-COVID-19 symptoms that may be undergoing comparable inflammatory processes.
(With inputs from PTI)
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