There is a five to fifty percent chance that someone who contracts SARS-CoV-2, the virus that is causing the still-very-much-ongoing global pandemic, would also contract Long COVID. It’s a disorder that, while certain theories have started to gain traction, has so far eluded rigorous research or explanation.
A new study out of Canada has discovered that blood samples from symptomatic patients with extended COVID can reveal indicators of autoimmune illness up to a year after the onset of symptoms. This provides another piece of supporting information.
Manali Mukherjee, the project’s lead researcher and an assistant professor in the Division of Respirology at McMaster University’s Department of Medicine, said in a statement, “I’m a respiratory researcher with a background in investigating the immune system. “After personally enduring protracted COVID symptoms, I started to consider the immune system’s potential contribution to this disorder.”
Mukherjee and associates, therefore, enlisted more than 160 participants for lengthy research monitoring the signs, symptoms, and antibodies of those recovering from a COVID infection. The majority of the participants—106 in total—were those who received a COVID diagnosis between August 2020 and September 2021, while the remaining participants made up two control groups, one with 22 healthy volunteers and the other with 34 people who had a non-COVID respiratory infection.
Patients were polled for signs of extended COVID, such as exhaustion, coughing, or shortness of breath, at three, six, and twelve months after recovery. Blood samples were also taken. These were examined for two autoantibodies—antibodies that target the body’s own cells and have previously been connected to severe COVID infection and hospitalization—as well as for particular antibodies known to contribute to autoimmune illness.
Even for the majority of the patients in our study who developed autoantibodies immediately after contracting the virus, this went away after a year, according to Mukherjee. Autoantibodies do, however, remain in certain patients, and these patients are more likely to continue to experience symptoms and require medical attention.
That fits well with one of the most popular hypotheses on the syndrome, which holds that the initial infection pushes the body’s immune system into overdrive, causing it to fight both the virus and healthy cells. That explains why lengthy COVID has so many similarities to autoimmune disorders including postural orthostatic tachycardia syndrome (POTS) and chronic fatigue syndrome, in which the body’s immune system causes the heart rate and blood pressure to become dysregulated.
Nearly four out of every five COVID patients had two or more of the harmful antibodies in their blood three months after infection, and this percentage remained stable at six months. The ratio has decreased to a little over two out of every five patients after a year. The healthy and COVID-free control groups, in contrast, had little to no blood evidence of the markers.
The study also discovered that nearly one-third of COVID patients had autoantibodies in their blood, even a full year after infection. However, the researchers add that at this stage, the number of participants had dramatically decreased, probably because of recovery. Additionally, the immune system’s messenger proteins known as cytokines, which can increase inflammation and potentially exacerbate COVID cases, were found in higher concentrations in these patients.
These findings are unquestionably important from a diagnostic standpoint, but they also most likely have real-world treatment implications.
“Long COVID affects millions of people worldwide, and thus has a significant socioeconomic impact. However, there is a lack of evidence regarding why some people develop the condition and how we can aid patients in recovering, according to Eva Polverino, a pulmonologist at Vall d’Hebron University Hospital in Barcelona, Spain, and head of the European Respiratory Society’s Respiratory Infections Assembly. She was not involved in the study.
“We are aware that some infections have the potential to initiate chronic autoimmune conditions like rheumatoid arthritis. According to Polverino, this study “adds to the mounting evidence that similar processes may be engaged in extended COVID. We may have a better grasp of extended COVID and how to diagnose and treat the disorder if we do more research in this area.