Nasal Swab May Predict Severity of COVID-19

New research from Emory University suggests autoantibodies in the nasal cavity may predict the severity of COVID-19 disease. A simple nasal swab may provide critical information that can help shape treatment plans.

According to a report published in Science Translational Medicine, more than 70 percent of people with mild or moderate COVID develop autoantibodies in their nasal cavities that are linked to fewer symptoms, better immune response and faster recovery. Autoantibodies usually attack the body and are typically associated with autoimmune diseases such as rheumatoid arthritis, inflammatory bowel disease and psoriasis.

“Generally, autoantibodies are associated with pathology and a negative prognosis, causing increased inflammation that would indicate more severe disease,” said senior researcher Eliver Ghosn, a faculty member with the Emory University’s Lowance Center for Human Immunology and Emory Vaccine Center. “What’s interesting about our findings is that with COVID-19, it’s the opposite. The nasal autoantibodies showed up soon after infection, targeting an important inflammatory molecule produced by the patient’s cells,” Gohsn explained.

Previous studies of COVID patients have suggested that autoantibodies in the blood indicate a more life-threatening illness, but the nose is the actual site of the infection, researchers said.

“These autoantibodies latched on to the molecule, likely to prevent excessive inflammation, and faded as people recovered, suggesting the body uses them to keep things in balance,” Gohsn added. These findings indicate that the immune response mounted in the nose against COVID differs from that mounted in the blood. Nasal autoantibodies provide protection, while autoantibodies in the blood are linked to more severe COVID.

“The key to this puzzle was to look directly at the site of infection, in the nose, instead of the blood,” Ghosn said. “While autoantibodies in the blood were linked to bad prognosis, producing them only in the nose soon after infection is linked to efficient recovery.”

Researchers are working to develop a nasal swab test that could be used to predict how bad a person’s COVID infection will prove to be.

“Right now, we’re either looking at infection risk before it happens or analyzing the infection course well after recovery,” said researcher Ben Babcock, a doctoral candidate at Emory. “Imagine if we could capture the immune response in real time, right in the clinic. A just-in-time test could give physicians and patients the real-time information they need to make faster, smarter treatment decisions.”