Researchers from the Nutritional Sciences Department at the University of Arizona, in collaboration with Stony Brook University and Wake Forest University School of Medicine, have identified an enzyme that may be the most important factor in predicting which patients with severe COVID-19 eventually die from the virus.
The study, published in the Journal of Clinical Investigation, found that high levels of secreted phospholipase A2 group IIA (or sPLA2-IIA) have the capacity to destroy the membranes of vital organs. The enzyme normally exists in low levels in healthy individuals and plays a critical role in defense against bacterial infections. In cases of severe COVID-19, though, something is going awry.
According to senior author Floyd (Ski) Chilton, who directs UArizona's Precision Nutrition and Wellness Initiative, "This enzyme is trying to kill the virus, but at a certain point it is released in such high amounts that things head in a really bad direction, destroying the patient's cell membranes and thereby contributing to multiple organ failure and death."
The study analyzed blood samples from two COVID-19 patient cohorts, one from patients hospitalized at Stony Brook University between January and July 2020, and another, independent cohort from Stony Brook and Banner University Medical Center in Tucson between January and November 2020. The research team analyzed thousands of patient data points using machine learning algorithms, taking into account traditional risk factors like body mass index and preexisting conditions, as well as biochemical enzymes.
"In this study, we were able to identify patterns of metabolites that were present in individuals who succumbed to the disease," said lead study author and NSC assistant research professor Justin Snider. "The metabolites that surfaced revealed cell energy dysfunction and high levels of the sPLA2-IIA enzyme. The former was expected, but not the latter."