October 30, 2020 -- For some people with severe COVID-19, the immune system may attack itself rather than the virus, according to a new study published on the preprint server MedRxiv. The study has not yet been peer-reviewed.
In these patients, the body creates “autoantibodies” that target human cells instead of the virus, similar to other autoimmune diseases such as lupus and rheumatoid arthritis.
If doctors can detect these autoantibodies, they may be able to treat patients with drugs that already exist for autoimmune conditions, according to The New York Times. The treatments aren’t a “cure” but can reduce the severity of symptoms.
“It’s possible that you could hit the appropriate patients harder with some of these more aggressive drugs and expect better outcomes,” Matthew Woodruff, the lead author and an immunologist at Emory University in Atlanta, told the newspaper.
Woodruff and colleagues studied 52 patients in Atlanta who had severe or critical COVID-19 and no history of autoimmune disorders. They found autoantibodies in about half of the patients, and among the top 50% of the most severe cases more than 70% had autoantibodies.
Some of the autoantibodies were associated with blood clotting and blood flow problems, which could be related to the coagulation issues seen in COVID-19 patients this year. If long-lasting, the autoantibodies may create long-term issues that don’t have a cure and last for life, Ann Marshak-Rothstein, an immunologist and lupus expert at the University of Massachusetts, Worcester, told the newspaper.
“You never really cure lupus — they have flares, and they get better and they have flares again,” she said. “And that may have something to do with autoantibody memory.”
Other viral illnesses also trigger autoantibodies, so the findings make sense, scientists who weren’t involved with the study said. Certain immune cells — called B immune cells — make antibodies against virus invaders, but sometimes, the body mistakenly produces antibodies based on dead human cells killed by the virus.
“I’m not surprised, but it’s interesting to see that it’s really happening,” Akiko Iwasaki, an immunologist at Yale University, told the newspaper. “It’s possible that even moderate to mild disease may induce this kind of antibody response.”