“Researchers are beginning to understand how the human immune system contributes to the varied responses to COVID-19. Autoantibodies—immune system proteins that mistakenly target the body’s own tissues—may underlie some of this variation. Autoantibodies are found in a wide range of autoimmune diseases, such as lupus and rheumatoid arthritis. Many people with low levels of autoantibodies in their blood have no obvious symptoms.
A recent study found that autoantibodies that existed before infection with SARS-CoV-2 may account for 20% or more of serious or fatal COVID-19 cases. Scientists have wondered if infection with SARS-CoV-2 could also result in the production of autoantibodies in people who didn’t have them before they got sick.”
“Researchers are beginning to understand how the human immune system contributes to the varied responses to COVID-19. Autoantibodies—immune system proteins that mistakenly target the body’s own tissues—may underlie some of this variation. Autoantibodies are found in a wide range of autoimmune diseases, such as lupus and rheumatoid arthritis. Many people with low levels of autoantibodies in their blood have no obvious symptoms.
A recent study found that autoantibodies that existed before infection with SARS-CoV-2 may account for 20% or more of serious or fatal COVID-19 cases. Scientists have wondered if infection with SARS-CoV-2 could also result in the production of autoantibodies in people who didn’t have them before they got sick.”
https://www.nih.gov/news-events/nih-research-matters/autoimmune-response-found-many-covid-19
They also use hydroxychloroquine to treat autoimmune diseases.