The concentration of specific metabolites in the blood could act as the foundation for a quick, inexpensive blood test that detects not only the presence of COVID-19 but which patients are at risk of becoming critically ill, according to a pan-Canadian study that included researchers from the University of Alberta.
The study, led out of Western University, found that COVID-19 decreases the blood concentration levels of three metabolites-small molecules broken down in the human body through the process of metabolism-and increases another.
The Metabolomics Innovation Centre at the U of A measured plasma concentrations of 162 metabolites from 10 COVID-19 patients, 10 patients with other infections admitted to ICU, as well as 10 healthy control participants.
David Wishart, co-director at the centre and professor in the U of A's Faculty of Science and Faculty of Medicine & Dentistry, explained metabolites are the final breakdown products in the human body and play key roles in cellular activity and physiology.
"By studying metabolites, we can understand chemical processes that are occurring at any given moment, including those that regulate biological functions related to health and disease," he said. "Because the human metabolome responds very quickly to environmental factors like pathogens, metabolomics can play an important role in early-stage disease detection, including for COVID-19."
The concentration of one metabolite called-kynurenine-was elevated in COVID-19 patients while concentrations of others-arginine, sarcosine and lysophosphatidylcholines-were decreased.
After further analysis, the researchers discovered by studying the concentrations of only two metabolites-kynurenine and arginine-they could distinguish COVID-19 patients from healthy participants and other critically ill patients with 98 per cent accuracy.
The team also discovered that concentrations of two metabolites-creatinine and arginine-could be used to predict which critically-ill COVID-19 patients were most at risk of dying. When measured on a patient's first and third day in ICU, these metabolites predicted COVID-19-associated death with 100 per cent accuracy.
The team also suspects those metabolites depleted by the virus could be delivered to patients as dietary supplements, acting as a secondary therapy that could improve disease outcomes.
For example, the metabolite arginine is essential to tissue repair while the metabolite sarcosine activates a process to remove damaged cells. Knowing that COVID-19 causes hyperinflammation that can damage cells and tissue, particularly in the lungs, supporting these processes may prove critical."
"Providing dietary supplements could be a simple adjunctive or secondary therapy with meaningful outcomes," said Douglas Fraser, lead researcher from Western University.
In an earlier study, the team was the first to profile the body's immune response to the SARS-CoV-2 virus and discover six potential therapeutic targets to improve outcomes. In other studies, they have discovered additional biomarkers that could be used to predict how severely ill a COVID-19 patient will become and uncovered a mechanism causing blood clots in COVID-19 patients and potential ways to treat them.