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Researchers in the latest study found the reason behind people losing smell during COVID-19 by studying the tissue removed from the patients’ noses during surgery.

Researchers have studied the nose tissues removed from the patients during surgery and have discovered the reason why so many people with COVID-19 lose their sense of smell even when they have no other symptoms.

In an experiment to find the reason behind this, researchers have found extremely high levels of angiotensin-covering enzyme II only in that area of the nose which is responsible for the smell.

This enzyme is known to be the entry point that allows the coronavirus to get into the cells of the body and cause an infection.

The researchers say that their findings offer clues on why the transmission of coronavirus is so fast and targeting this part of the body could provide more effective treatments.

This study by Professor Andrew P Lane, director of the division of rhinology and skull-based surgery along with his research associate had published their study in the Respiratory Journal of Europe.

Professor Lane mentioned in the journal that while other respiratory viruses generally cause loss of the sense of smell through the obstruction of airflow due to the swelling of nasal passages, coronavirus sometimes causes loss of smell in the absence of other nasal symptoms like cold or swelling of nasal passages.

The research team used samples from the back of the nose of 23patients which were removed during endoscopic surgical procedures for conditions like tumor or chronic rhinosinusitis.

They also studied the biopsies of the windpipe/trachea of seven patients and none of the patients have been diagnosed with coronavirus.

In the lab, the researchers used fluorescent dyes on the tissue samples to detect and visualize the presence of Angiotensin covering enzyme under a microscope. Then they compared the levels of this enzyme in different cell types and parts of the nose and upper airway.

They found by far that the enzyme was mostly found on the lining areas of the olfactory epithelium which is an area at the back of the nose which detects smells.

The levels of this enzyme were between 200 to 700 times higher in the trachea than the other areas of the nose. They found similarly high levels of this enzyme in the olfactory epithelium.

The olfactory epithelium is quite an easy part of the body for the coronavirus to enter and is not buried away deep in our body and the very high levels of this enzyme also explain why COVID-19 is so easy to catch.

However, these findings need to be confirmed and if proven true this could provide a new dimension for treating the infection.

By Gayatri Yellayi