“Interferons are like a fire alarm and a sprinkler system all in one,” said Rasmussen, who wasn’t involved in the new studies.
Lab studies show interferons are suppressed in some people with COVID-19, perhaps by the virus itself.
Interferons are particularly important for protecting the body against new viruses, such as the coronavirus, which the body has never encountered, said Zhang, a researcher at Rockefeller University’s St. Giles Laboratory of Human Genetics of Infectious Diseases.
When infected with the novel coronavirus, “your body should have alarms ringing everywhere,” said Zhang. “If you don’t get the alarm out, you could have viruses everywhere in large numbers.”
Significantly, patients didn’t make autoantibodies in response to the virus. Instead, they appeared to have had them before the pandemic even began, said Paul Bastard, the antibody study’s lead author, also a researcher at Rockefeller University.
For reasons that researchers don’t understand, the autoantibodies never caused a problem until patients were infected with COVID-19, Bastard said. Somehow, the novel coronavirus, or the immune response it triggered, appears to have set them in motion.
“Before COVID, their condition was silent,” Bastard said. “Most of them hadn’t gotten sick before.”
Bastard said he now wonders whether autoantibodies against interferon also increase the risk from other viruses, such as influenza. Among patients in his study, “some of them had gotten flu in the past, and we’re looking to see if the autoantibodies could have had an effect on flu.”
Scientists have long known that viruses and the immune system compete in a sort of arms race, with viruses evolving ways to evade the immune system and even suppress its response, said Sabra Klein, a professor of molecular microbiology and immunology at the Johns Hopkins Bloomberg School of Public Health.
Antibodies are usually the heroes of the immune system, defending the body against viruses and other threats. But sometimes, in a phenomenon known as autoimmune disease, the immune system appears confused and creates autoantibodies. This occurs in diseases such as rheumatoid arthritis, when antibodies attack the joints, and Type 1 diabetes, in which the immune system attacks insulin-producing cells in the pancreas.
