Biomarkers
PHOTO FROM THE SITE OF THE UNIVERSITY OF STRASBOURG
The Dr Seiamak Bahram
“The main predictor of the risk of having a severe form of COVID-19 is age,” explains Seiamak Bahram, of the University of Strasbourg. “Elderly patients are at greater risk. But we also see severe forms in younger adults. We have to find a way to predict who will have a serious form. It will be a biomarker, either a molecule present in the patient’s blood or urine, or a genetic mutation that predisposes to severe forms. With biomarkers, we can monitor patients at risk more closely and intubate them more quickly, if necessary. ”
The Dr Bahram is the lead author of a study published at the end of October that discerned a human genetic mutation increasing the risk of severe COVID-19 in people under 50. The French immunologist’s study was carried out on 300 patients under the age of 50 hospitalized for COVID-19 in the spring of 2020, half of whom stayed in intensive care. The most promising genetic mutation for predicting the risk of severe COVID-19 is also implicated in certain cancers. A drug called a “monoclonal antibody” is tested against these cancers.
Four avenues
The search for biomarkers predicting the risk of severe COVID-19 is complicated by vaccination successes. “There are fewer severe patients now, so clinical studies are more complicated,” says Dr.r Bahram. But the work that has already been done by dozens of researchers around the world has found different avenues, according to Donald Vinh, infectious disease specialist at the McGill University Health Center. He has just filed a patent application for a biomarker predicting severe COVID-19.
First avenue: signs of the disease
PHOTO EDOUARD PLANTE-FRÉCHETTE, ARCHIVES THE PRESS
The Dr Donald Vinh, infectious disease specialist at the McGill University Health Center
The first biomarkers detected directly reveal the severity of the patient’s condition. “But it is not so useful, the patient is already very sick, observes the D.r Vinh. For example, we take the reactive protein C, which is a biomarker reflecting inflammation. In general, the sicker you are, the higher your CRP level. But you may need an anti-inflammatory treatment or an antiviral treatment. Or you can have a high CRP level with other diseases, such as arthritis. ”
Second avenue: immune system
The biomarker detected by Dr Vinh, described in a study published by the journal Cell Press, is a cocktail of DNA cells released from diseased cells in the human body, before the patient’s serious condition becomes evident. This is an initial response of the immune system.
Third avenue: viral genetics
In the review Cell Discovery, Chinese researchers have detected a genetic signature specific to SARS-CoV-2, the coronavirus responsible for COVID-19, when it penetrates with great success into a patient’s cells. “It is a biomarker which indicates that the virus is well established in a patient”, confirms the Dr Vinh.
Fourth avenue: human genetics
It is the discovery of Dr Bahram: a genetic mutation that predisposes to having a severe form of COVID-19. “This is the next step in medicine, molecular medicine,” explains Dr.r Vinh.
Flu
Even though biomarkers predicting severe COVIV-19 are never used clinically because vaccines remain effective, this work is not lost, says Dr.r Vinh. “We have the same problem with the flu, for example. Some patients have severe forms, but we do not know which ones will be affected, says the Montreal infectious disease specialist. All the work we are doing now on these biomarkers of severe forms of COVID-19 could benefit other diseases and other pandemics, if they emerge. ”