New research indicates that measuring plasma levels of soluble urokinase plasminogen activator receptors (suPAR), a key protein biomarker of inflammation, could help provide earlier prognosis of COVID-19’s development.
The new study published in the Critical Care journal claims that elevated plasma levels of suPAR can help identify severe respiratory failure much earlier in COVID-19 patients.
Per the World Health Organisation (WHO), most people suffering from COVID-19 will develop mild to moderate respiratory problems, but the majority might recover on their own. Therefore, having an accurate indication of poor cardiovascular health could help doctors allocate ventilators in short supply more efficiently, especially to those who need the devices the most.
The study looked at the blood work of 15 patients with COVID-19 infection at Rush University Medical Center in Chicago. The U.S. cohort was compared to 57 COVID-19 patients treated at the University of Athens Medical School in Greece.
The researchers found that the levels of suPAR were significantly higher during hospital admission for those who developed severe respiratory failure. Based on the analysis, blood levels of suPAR greater than 6 ng/ml was the best predictor for respiratory failure because the time taken for the disease to evolve was much less in comparison to patients with low suPAR levels.
“There is a body of literature that suPAR is associated with poor outcomes from acute respiratory distress syndrome (a condition in many patients with severe COVID-19) and poor lung functioning in critically ill patients,” Jochen Reiser, MD, PhD, Ralph C. Brown, MD, Professor of Internal Medicine, chairperson of the Department of Internal Medicine at Rush, said, as quoted by the press release.
According to the researchers, patients with high plasma suPAR needed immediate intubation. So, measuring suPAR levels can help doctors figure out who to monitor closely. “Plasma suPAR levels give us a window into the course of the disease, allowing for improved monitoring and applying new and supportive treatments early,” Reiser explained.
While generally C-reactive protein (CRP) is the main marker checked for cardiovascular risk and inflammation, a high level of the suPAR protein is an overall indicator of mortality risk and can be useful for research in more ways than one. It can additionally help determine the potential decline in kidney function, which is a characteristic observed in several recent COVID-19 cases.
Two of Reiser’s research papers published in The New England Journal of Medicine showed that an increase in several biomarkers of disease could be linked to chronic kidney disease.
“Our research on suPAR and COVID-19 associated lung injury is based on a small sample size, and we will need more data, but the findings support a concept that suPAR is harmful in COVID-19. It may therefore play a prognostic and a causal role in COVID-19 associated kidney disease,” he said.
Flattening the curve is limited to social distancing, but being able to predict disease-severity could reveal early on which patients need more intense management, at least in terms of acute anti-inflammatory treatment.
“Whether modification of circulating suPAR is a useful therapeutic option will require further study,” the paper concluded.