Researchers discover link between 'long COVID' and blood

Researchers at Lawson Health Research Institute have discovered unique blood biomarkers in patients suffering from post-COVID-19 (long COVID), and are now developing a first of its kind blood test that could be used to diagnose the condition. The findings were published this week in Molecular Medicine.

Long COVID occurs when someone experiences symptoms like fatigue, cognitive issues, shortness of breath and gastrointestinal issues after an initial COVID-19 diagnosis. It can sometimes take up to 12 months for the condition to occur. Wendi Heal has been suffering from its effects since January of 2021.

"When I left hospital I was told to expect six to eight weeks, maybe three months. And there were periods when I would feel better. But if I overexerted myself, either physically or mentally, man, my mind body shut down."

According to the study, an estimated 30 to 40 per cent of patients with COVID-19 will develop long COVID.

"Not everyone but a large majority described some symptoms and then continued to describe symptoms and it was quite variable," says Dr. Michael Nicholson, Associate Scientist at Lawson, and Respirologist at St. Joseph’s hospital.

Researchers wanted to find out what was causing these symptoms, and began to study blood vessels because it was the connection between the several organs that were involved.

"What we found was really quite impressive that the blood vessels are going through dramatic changes. And this can curve again for months, even years. And we measured proteins in the blood that reflect those changes going on in the blood vessels," says Dr. Douglas Fraser, Lawson Scientist and Critical Care Physician at London Health Sciences Centre (LHSC)

In the study of 140 blood samples from participants, it was discovered that patients had 14 elevated blood biomarkers, and through machine learning two of those biomarkers could be used to classify long COVID with 96 per cent accuracy.

"Our research now is looking at how to develop a point of care diagnostic test that can be used in a family doctor's office and urgent care Urgent Care Clinic, any number of environments," says Fraser

With the ability to diagnose, now research can shift to how to treat it.

"It's a tip of the iceberg, hopefully, uncovering more to then maybe allow more targets to be found and then potentially options for treatment," says Nicholson

The blood test that is in developed will one day give physicians an accurate gauge to diagnose and hopefully treat those suffering from the after effects of the COVID-19 virus.