A treatment for anosmia, a condition that leads to a temporary or permanent loss of smell, is already showing promising results in patients in Belgium and could be used to help treat one of the long-lasting effects of Covid-19.
Professor Jérôme Lechien of the University of Mons is the only surgeon in Belgium to use the technique called PRP (Platelet-Rich Plasma), an approach which originated in the United States. The basic principle is quite simple and does not require any medication.
After a blood sample is taken from the patient, platelets from the blood are then removed and concentrated before being injected into the upper part of the patient's nose, where the smell receptors are located. By injecting the platelet concentrate, regeneration of the receptors is encouraged and people can recover their sense of smell faster.
Effective in 80% of cases
The first results from Professor Lechien’s work in Belgium are encouraging. "Our study shows that people who are injected with PRP recover faster than people who do nothing," he told RTBF. The only downside observed so far is that PRP is only effective in 80% of cases.
In total, between 350 and 400 patients have been treated with PRP in Mons. 81% of them noticed an improvement in their sense of smell over a period of time between three weeks and six months. "Most people feel a positive effect after three weeks, which is usually manifested by the ability to smell, for a fraction of a second, odours that they no longer smelled," Professor Lechien explained. "This is a sign that it is recovering."
It is estimated that less than 5% of the population suffers from anosmia. The impact of the smell disorder on those affected is quite significant with some odours completely disappearing while others are strongly altered. Patients can also experience a loss of taste as a result.
In addition to this significant impact on the daily life of patients, this situation can even be dangerous in some cases, such as the non-detection of gas or burning odours.
A visible symptom of Covid-19
The loss of smell is also one of the most visible symptoms of Covid-19. "The virus will bind to the receptors, present in abundance at the level of the olfactory organ," explained Jérôme Lechien.
"The immune system will try to prevent the virus from entering the body and will then destroy the cells of the olfactory organ [...] Once these cells are destroyed, patients can no longer pick up odours."
At the beginning of the pandemic, between 50% and 86% of patients were affected by a loss of smell. In half of the cases, these patients recovered their olfactory sense after one to two weeks. But this is not necessarily guaranteed, as the virus does not act in the same way with everyone: "Two years later, 28% of these patients retain a long-term sense of smell deficit," explained Professor Lechien.
The PRP treatment could be a way for these people to recover their sense of smell.