Researchers find blood profile for screening severe COVID-19 cases from mild ones

A simple blood test may be able to help clinicians understand why one patient with COVID-19 may develop severe, life-threatening complications while another may show barely any symptoms at all.

Researchers at the Charité university hospital in Berlin found several protein-based biomarkers that, when taken together, could be capable of predicting a person’s course of disease using laboratory equipment capable of running dozens of samples per day.

Using mass spectrometry analysis, they found a set of 27 different proteins in blood samples from coronavirus patients being treated in the hospital—with different levels correlating with the severity of their disease, according to the World Health Organization's coding criteria for COVID-19.

"These results lay the foundations for two very different applications," said Markus Ralser, director of Charité's Institute of Biochemistry and a group leader at the Francis Crick Institute in London. "One possible future use would be for disease prognosis. An early blood test would enable the treating physician to predict whether or not a patient with COVID-19 will develop severe symptoms."

"This could potentially save lives: the sooner physicians know which patients will require intensive care, the faster they can make use of the available treatment options," Ralser said.

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"Another possible future use would be as an in-hospital diagnostic test, which could provide clarity regarding a patient's condition—regardless of how they themselves describe it," he added. "In some cases, a patient's symptoms do not appear to provide an accurate picture of their true health status. An objective evaluation, based on their biomarker profile, could be extremely valuable in this regard." 

The researchers now plan to test their method in a larger number of patients, while studying how the protein biomarkers change over the course of the disease. Their findings were published in the journal Cell Systems.

Some of the 27 proteins had not previously been linked to an immune response, they said, while others included clotting factors and regulators of inflammation—one of the hallmarks of severe COVID-19 cases—and engage with interleukin-6 at the molecular level.

Roche recently received an FDA emergency authorization for its IL-6 test to help identify coronavirus patients who may enter respiratory failure or require a ventilator. IL-6 is released by immune cells, triggering fevers and other defenses, and plays a role in potentially fatal cytokine storms.