Testing for Specific Genetic Biomarkers Could Diagnose SARS-CoV-2 Infection and Predict COVID-19 Severity

Scientists have discovered specific genetic biomarkers that not only show who is infected with COVID-19, but also offer insights into how severe the disease might be, thus filling a major diagnostic gap.

The new study by scientists at the University of Colorado School of Medicine (Aurora, CO, USA) suggests that specific signals from a process called DNA methylation varies between those infected and those not infected with SARS-CoV-2. And they can indicate the severity of the disease even in the early stages. DNA methylation, critical in how cells function, is an epigenetic signaling tool that cells use to turn genes off. Any mistakes in the process can trigger a variety of disease. The researchers believe that paying attention to these signals could help fill a needed gap in the current world of COVID testing.

Most COVID-19 antigen or rapid tests are dependent on viral strains and can carry high false negative rates. They do not predict if the virus is viable and replicating, nor do they predict clinical outcomes. A pre-symptomatic patient may test negative for the SARS-CoV-2 virus while patients who have recovered may still test positive despite no longer being infectious. The researchers did not know of any test that can predict the clinical course of COVID-19.

With that in mind, they analyzed the epigenome in blood samples from people with and without COVID-19. They did this by customizing a tool from Illumina called the Infinium Methylation EPIC array to enhance immune response detection. Researchers then profiled peripheral blood samples from 164 COVID-19 patients and 296 control patients. The peripheral blood DNA samples were collected from patients seen at UC Health and tested for SARS-CoV-2 epigenetic signatures starting March 1, 2020. The researchers discovered specific genetic markers of SARS-CoV-2 infection along with indications of how severe the disease might be. According to the researchers, the findings could ultimately lead to a new and more accurate way to test for COVID-19.

“I think this study is a tremendous proof-of-concept in the realm of COVID-19 testing, one that can be applied to other diseases,” said the study’s lead author, Kathleen Barnes, PhD, professor at the CU School of Medicine. “It’s a major move forward in the world of precision medicine.”

“We are exploring how this platform could add value to the COVID diagnostic world,” she said. “We think it adds value to knowing what patients develop more serious disease. This could tell you if you could ride out the infection or if it is likely to get worse.”

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University of Colorado School of Medicine