SARS-CoV-2 infection can trigger an immune system response that lasts long after a patient has recovered, even in people who have had no or mild symptoms of COVID-19, according to found a team of scientists from Cedars-Sinai.
When we become infected with a pathogen, our bodies release antibodies, proteins capable of identifying foreign substances and preventing them from entering our cells; However, when faced with an infection, it can also happen that we produce autoantibodies, which attack the organs and tissues of our body.
It was already known that the immune system of people who developed a severe case of COVID-19 could be stressed in such a way that autoantibodies were produced, but in the new research, which has been published in the Journal of Translational Medicine, it has been shown that people who had overcome COVID-19 presented a wide variety of autoantibodies in the very long term: up to six months after their complete recovery.
“We found signs of autoantibody activity that are generally related to chronic inflammation and injuries involving organs such as the joints, skin, and the nervous system”
The study is the first to report not only the presence of high levels of autoantibodies after a mild or asymptomatic infection, but also their persistence over time. “These findings help explain what makes COVID-19 an especially unique disease,” said Justyna Fert-Bober, a research scientist in the Department of Cardiology at the Smidt Heart Institute and co-senior author of the study. “These patterns of immune dysregulation could underlie the different types of persistent symptoms we see in people who develop the condition now known as long-term COVID-19.”
Autoantibodies present in autoimmune diseases
The Cedars-Sinai researchers selected 177 people who had previously been infected with SARS-CoV-2 and compared samples of their blood with samples from healthy people before the pandemic. All those with confirmed SARS-CoV-2 infection had elevated levels of autoantibodies. Some of the autoantibodies have also been found in patients with diseases in which the immune system attacks its own healthy cells, such as lupus and rheumatoid arthritis.
“We found signs of autoantibody activity that are generally related to chronic inflammation and injury involving specific organ systems and tissues such as the joints, skin, and nervous system,” explained Dr. Susan Cheng, director of the Research Institute in Healthy Aging in the Department of Cardiology at the Smidt Heart Institute and co-senior author of the study.
Autoimmune diseases tend to be more common in women, but we also know that men are more vulnerable to more severe forms of COVID-19
Some of the autoantibodies have been linked to autoimmune diseases that generally affect women more than men, but in this research it was observed, on the contrary, that men had a higher amount of elevated autoantibodies than women. “On the one hand, this finding is paradoxical, given that autoimmune diseases tend to be more common in women,” Fert-Bober said. “On the other hand, it’s also somewhat expected given everything we know about men being more vulnerable to more severe forms of COVID-19.”
This team of scientists intends to expand the study to identify the types of autoantibodies that may be present and persist in people with symptoms of persistent COVID-19. Because this study was conducted in people who had been infected before there were vaccines, the researchers will also study whether autoantibodies are generated in a similar way in people with breakthrough infections (those that occur in individuals who have had the full course of vaccination ).
“If we can better understand these autoantibody responses, and how SARS-CoV-2 infection triggers and drives these variable responses, then we can go one step further in identifying ways to treat and even prevent these effects from developing in people. at risk,” concludes Cheng.
