All over the world, immunologists, joining the fight against SARS-CoV-2, are trying to explain why some people are difficult to tolerate the disease, while others do not notice it. The pace is dizzying, but there are clear trends.
One of the priority areas was the production of antibodies – powerful proteins that can disable and kill invading pathogens such as viruses. Of great concern is the sporadic identification of so-called autoreactive antibodies, which, instead of targeting disease-causing microbes, target tissues of people suffering from severe cases of COVID-19.
Early research showed that these autoantibodies form dangerous blood clots in patients admitted to intensive care. Recently, they have been associated with critical components of viral immune defense in a significant proportion of patients with severe illness.
As an immunologist at the Lowance Center for Human Immunology at Emory University, I study the immune response responsible for producing antibodies in COVID-19. Under the direction of Dr. Ignacio Sansa, our group has previously investigated immune responses that promote the production of autoantibodies in autoimmune diseases such as lupus, and more recently in severe cases of COVID-19.
However, while we were able to characterize the response of COVID-19 patients as autoimmune, we were unable to confirm the production of autoantibodies latent in their antiviral responses.
Now we can.
In a recently published pending peer review study, we describe the alarming finding that autoantibody production is common in the most severe COVID-19 patients – a discovery with great potential impact on both emergency patient care and infection recovery.
An autoreactive antibody test can show the best treatments.
The tests performed on these patients to determine their 'autoreactive profile' are not specialized. They are available in most hospital laboratories around the world.
Indeed, the two most common antibodies that we find in these patients, antinuclear antibodies and rheumatoid factor, are detected using routine tests used by rheumatologists.
Our research shows that by testing only these two autoantibodies and the inflammatory marker c-reactive protein, we can identify patients who are more likely to experience potentially dangerous immune responses that could be helped by more aggressive immunomodulation.
In addition, autoreactivity testing can help identify patients who may benefit from rheumatologic surveillance to monitor recovery and help us understand if some cases of 'long-range' COVID-19 may be associated with persistent autoantibodies.
Finally, by testing patients immediately after recovering from COVID-19, we can establish baseline data and start tracking the possible emergence of new cases of autoimmunity after this terrible disease, as well as plan early rheumatologic intervention if necessary.
We now have the tools. It's time to start using them.
Matthew Woodruff, Instructor, Lowance Center for Human Immunology, Emory University.
Article published by The Conversation.
Sources: Photo: Micrograph of a dying cell (red) heavily infected with SARS-COV-2 (yellow). (NIAID, NIH)
