McMaster-led study says more research needed into the effects of long COVID, autoimmunity

An undated electron microscope image made available by the U.S. National Institutes of Health in February 2020 shows the Novel Coronavirus SARS-CoV-2, yellow, emerging from the surface of cells, blue/pink, cultured in the lab. Also known as 2019-nCoV, the virus causes COVID-19. THE CANADIAN PRESS/AP-NIAID-RML via AP.

A McMaster University-led study is suggesting more research is needed into the connection between human autoimmunity and long COVID patients who continue to suffer symptoms for a year or more.

The study, one of two on the long-term effects of those who have had COVID-19 infections, has been published in the European Respiratory Journal. The study revealed that about 25 per cent of some 100 people surveyed continued to have at least one of the three most common symptoms of the affliction — coughing, fatigue or breathlessness.

Read more: As COVID-19 lingers, the need for national pharmacare progress is clear: experts

The sufferers, who all had no pre-existing autoimmune conditions or underlying diseases pre-pandemic, showed signs of abnormal antibodies, or autoantibodies, in their system, potentially contributing to ongoing health issues between 12 to 18 months after an infection.

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“What the study suggests is that there are patients who get better after contracting COVID, but there is a subset … who have long COVID symptoms, and they are associated with circulatory inflammatory markers,” Manali Mukherjee, assistant professor of medicine at McMaster, told 900 CHML’s Good Morning Hamilton.

“So there is inflammation still in these patients, and that’s what requires medical attention.”

Mukherjee is encouraging those with persistent long COVID symptoms past 12 months to seek out a rheumatologist — a physician who specializes in autoimmune disorders.

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Mukherjee said the science behind that consultation is due to a potential buildup of autoantibodies and cytokines, defence systems activated when fighting off an infection.

In September, the McMaster team suggested the two specific defences attack healthy tissues and are known to cause autoimmune disease, persisting in about a quarter of patients a year after they became infected.

Mukherjee explained that while the body is fighting COVID, the immune system gets amped up producing not only antibodies that kill the virus but defences that can attack a host.

Read more: Long COVID-19 linked with autoimmune diseases, Canadian study shows

The latter research was based on blood samples from patients who were diagnosed with COVID-19 between August 2020 and September 2021 and received care at two hospitals in Hamilton and Vancouver.

Mukherjee started research into long COVID after experiencing the condition herself exhibiting fatigue, shortness of breath, headaches and brain fog for close to 18 months, requiring her to limit some of her daily routines to recover.

“The truth is, it’s not the same presentation in everybody. It’s highly heterogeneous,” Mukherjee said.

“It varies from person to person, sometimes symptoms can completely go away, only to relapse back. It’s something that is being investigated.”

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She says ongoing research is focussing on individuals who were in good health prior to having COVID and are now having symptoms post-infection and not functioning.

The team hopes to finish the study by the middle of 2023 to help sufferers via medical interventions or treatments.

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