One mystery of the coronavirus is how it affects so many people differently, with some able to recuperate at home while others are hospitalized or even die.
Until recently, there has been no way for doctors to predict which outcome a patient will face.
A recent study by Yale researchers, however, has found that a series of biomarkers, or biological signals, associated with white blood cell activation and obesity can indicate severe outcomes in COVID-19 patients.
“Patients with high levels of these markers were much more likely to require care in the intensive care unit, require ventilation, or die due to their COVID-19,” said lead author Dr. Hyung Chun, an associate professor of medicine in cardiovascular medicine and pathology and director of translational research at the Yale Pulmonary Vascular Disease Program.
Previous studies had identified possible indicators, the researchers said, but “no laboratory marker could predict which patients with COVID-19 would eventually become critically ill prior to showing clinical signs and symptoms of severe disease.”
The Yale researchers used proteomic profiling — a screen for multiple proteins in blood — to analyze samples from 100 patients who would go on to experience different levels of COVID-19 severity. They also analyzed clinical data for more than 3,000 additional patients with COVID-19 within the Yale New Haven Hospital system.
Five proteins — resistin, lipocalin-2, HGF, IL-8, and G-CSF — that are associated with neutrophils, a type of white blood cell, were elevated in the COVID-19 patients who became critically ill. Many of these proteins had previously been associated with obesity but not with COVID-19.
One key finding was the presence of elevated neutrophil biomarkers before the patients developed more serious symptoms. All patients who were admitted to the hospital or transferred to intensive care had elevated biomarkers. In contrast, biomarkers remained low for patients who never became critical, and none of the patients with lower levels died.
“This is one of the first demonstrations that a set of biomarkers in the blood of COVID patients can predict eventual ICU admission, even before such patients become critically ill,” said study author Dr. Alfred Lee, associate professor of medicine in hematology, director of the Yale Medical Oncology-Hematology Fellowship Program, and a member of the Yale Cancer Center.
Having early knowledge of these indicators could significantly improve patient treatments, the researchers said.
“If a diagnostic test [for these biomarkers] could be ordered early, it could give us a better sense of who is more likely to become critically ill and will benefit from a higher level of care and consideration for therapies that affect the immune system early on in their hospitalization,” Chun said. “Many of these drugs do carry potential side effects, and these tests may help identify those patients who would benefit the most.”
The study was published Friday in the journal Blood Advances.
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