April 27 (UPI) -- A simple urine test may help predict which people infected with COVID-19 will develop severe illness from the disease, researchers said Tuesday.
Those infected with the coronavirus have higher levels of a specific type of protein associated with inflammation in their urine than those who did not have the virus, the scientists said.
In addition, amounts of these proteins, called cytokines, were higher in patients with pre-existing chronic health conditions, such as high blood pressure and diabetes.
People with these health conditions are thought to be at higher risk for severe illness from COVID-19, according to the researchers.
In all cases, cytokine levels declined to normal ranges once the infection resolves.
"We have observed, albeit in a small cohort of patients that we examined, that the urinary cytokine levels increase as the infection progresses, and that they decrease as the infection resolves," study co-author Dragana Komnenov told UPI in an email.
"This suggests that the urinary cytokine signature could potentially have diagnostic and-or prognostic value," said Komnenov, an assistant professor of research at Wayne State University in Detroit.
Many people who suffer serious illness from COVID-19 experience what researchers have called a "cytokine storm," in which the body produces these proteins to elevated levels and they, in turn, cause inflammation in multiple organs, including the lungs, heart and brain.
Urine tests for cytokine levels are being used to screen for a number of illnesses, including urinary tract infections and interstitial cystitis, according to LabTestsOnline.org, an online guide to diagnostic testing for consumers.
For this study, the results of which were presented virtually Tuesday during the American Physiological Society annual meeting, Komnenov and her colleagues compared urine cytokine levels in 17 patients with confirmed COVID-19 and 10 without the virus.
Levels of two cytokines, growth-regulated oncogene and interleukin-6, or IL-6, were "significantly elevated" in those with the virus, compared to those without, the researchers said.
Those in poorer health due to preexisting chronic health conditions had the highest urinary cytokine levels, they said.
"Our study indicates that we can detect specific biomarkers of inflammation in the urine of COVID-19 patients ... [and this] could provide us a snapshot of patients' infection status," Komnenov said.
However, "we definitely have to confirm such urinary cytokine trends in a larger cohort of patents, which is something we are working on right now," she said.