By Stephen Beech via SWNS
A new nasal swab test can accurately predict the severity of COVID-19 infections.
It provides a more precise prediction than currently available of how serious the case is by focusing on autoantibodies in the nasal cavity.
The test will lead to more personalized treatment plans, say American scientists.
And it could be adapted to test for other viruses, including flu.
Several COVID-19 symptoms exist, ranging from mild to severe, and while current strains of the virus generally cause milder symptoms, people with pre-existing medical conditions are still at much greater risk of severe illness.
Scientists say the new test could provide critical information to allow immediate treatment options for high-risk patients.
Researchers from Emory University in Atlanta, Georgia, tracked antibodies in both the blood and nasal airways of 125 patients with varying levels of COVID-19 infection for almost two years.
They found that more than 70% of patients with mild or moderate COVID-19 developed certain autoantibodies – generally an indication of disease – in the nose that was surprisingly linked to fewer symptoms, better antiviral immunity, and faster recovery.
The findings, published in the journal Science Translational Medicine, suggest that the presence of autoantibodies in the nose can play a “protective” role and help regulate the immune system to prevent excessive inflammation and fight off the virus more effectively.
Study senior author Dr. Eliver Ghosn said: “Generally, autoantibodies are associated with pathology and a negative prognosis, causing increased inflammation that would indicate more severe disease.
“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.
“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.”
Previous COVID-19 studies have suggested that autoantibodies in the blood predispose them to life-threatening disease.
But the Emory team pointed out that those studies often neglect the nose – the actual site of infection.
The new study suggests that the immune responses mounted in the nose against the virus differ from those in the blood.
In other words, nasal autoantibodies equal protection, whereas autoantibodies found in the blood equal severity.
Dr. Ghosn said: “The key to this puzzle was to look directly at the site of infection, in the nose, instead of the blood.
“While autoantibodies in the blood were linked to bad prognosis, producing them only in the nose soon after infection is linked to efficient recovery.”
To allow more precise measurements of antibodies produced locally in the nasal site of infection, Dr. Ghosn’s team developed a new biotechnology tool called FlowBEAT to measure different types of antibodies in nasal cavities and other biological samples.
Dr. Ghosn believes the findings could soon have implications for the testing of other respiratory viruses, including flu.
He said: “Historically, the technology to measure antibodies has low sensitivity and is inefficient since they are limited to measuring one or a few antibodies at a time.
“With FlowBEAT, we can take any standard nasal swab and perform a combination test to simultaneously measure all human antibody types against dozens of viral and host antigens in a single tube – a much more sensitive, efficient, and scalable way to measure for autoantibodies in the nose that can also predict the severity of symptoms.”
Now, the researchers want to find out whether the mechanism to control COVID-19 infection in the nose also plays a role in other respiratory infections.
Dr. Ghosn said: “If this nasal autoantibody response turns out to be a common mechanism to protect us against other viral infections, it can be a paradigm shift in how we study protective immunity.”
He added: “We will interpret autoantibodies through an innovative lens, hopefully inspiring new lines of research and better therapeutic options for common respiratory infections.”
Based on their findings, the team is now working with Emory’s patent office to develop a predictive diagnostic tool using “leftover” samples from standard nasal swabs widely used as a diagnostic test for COVID-19.
Ben Babcock, a PhD candidate who led the study in the Ghosn Lab, said: “Right now, we’re either looking at infection risk before it happens or analyzing the infection course well after recovery.”
He added: “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.”
