Rogue antibodies are major culprits in severe cases of COVID-19, researchers report. These autoantibodies target and react with a person’s tissues or organs similar to ones that cause autoimmune diseases such as lupus or rheumatoid arthritis. In COVID-19 cases they can attack healthy tissue in brain, blood vessels, platelets, liver, and the gastrointestinal tract, researchers report. The more autoantibodies detected, the greater the disease severity patients experience. And the autoantibodies paradoxically also target and interfere with many immune system proteins that are designed to fend ...