Two studies published today in the European Respiratory Journal describe long-COVID findings, one revealing signs of autoimmune disease in 41% of blood samples taken 1 year after recovery, and the other showing that 23% of patients still had exercise intolerance a year after hospital release.41% had signs of autoimmune disease at 1 yearIn the first study, a team led by McMaster University researchers in Canada obtained blood samples from 106 people who tested positive for COVID-19 from August 2020 to September 2021.
They also asked participants about long-COVID symptoms 3, 6, and 12 months after recovery.Twenty-two healthy volunteers and 34 people who had recovered from a non-COVID respiratory infection served as comparison groups.At 3 and 6 months, nearly 80% of the COVID-19 survivors had at least two antibodies that target healthy cells and tissues and contribute to autoimmune diseases, falling to 41% after 1 year.
In comparison, most healthy volunteers had no evidence of these antibodies, while those who had recovered from a non-COVID illness had relatively low levels.From 21% to 30% of COVID-19 patients—most who still had shortness of breath and fatigue—had specific antibodies (called anti-U1-snRNP and anti-SS-B/La autoantibodies) and proteins that cause inflammation (TNFα cytokines) at 1 year.Autoimmune disease occurs when the immune system mistakenly attacks healthy parts of the body instead of defending it against disease.
It causes conditions such as rheumatoid arthritis and lupus."These results point towards the need to test for signs of autoimmune disease in patients with symptoms of long COVID that last for a year or more," senior author Manali Mukherjee, PhD, of McMaster University, said in a European Lung