Persistent long COVID symptoms associated with marker for autoimmune disorders: study

A new Canadian study has found that a quarter of those with long COVID are still experiencing at least one symptom a year later.

The majority of those struggling with long COVID were found to have recovered within 12 months, regardless of how severe their symptoms were, providing some hope for recovery rates.

But those with persistent symptoms were more likely to have higher levels of a marker for autoimmune disorders, suggesting that lingering symptoms may need more attention for recovery.

“Generally, one should not worry if they are feeling unwell right after their infection, as the chances of recovering within 12 months is very high, and just because you have typical long COVID symptoms at three months does not mean they will stay forever,” Manali Mukherjee, assistant professor of medicine at McMaster University and senior author of the study, said in a press release.

“However, the study highlights that at 12 months, if you still feel unwell and the symptoms are persisting or worsening, you should definitely seek medical attention.”

Long COVID is the term for those dealing with a varying set of persistent symptoms more than 12 weeks after recovering from a COVID-19 infection, ranging from crippling fatigue to muscle pain to neurological issues. According to the World Health Organization, anywhere from 10 to 20 per cent of those who contract COVID-19 have experienced some form of long COVID.

For this study, published in the peer-reviewed European Respiratory Journal, researchers from McMaster and the University of British Columbia focused on three of the most common symptoms: fatigue, cough and shortness of breath.

In order to study the recovery process, researchers looked at 106 people who were in recovery from COVID-19 infections, checking in at three, six and 12 months after patients had contracted the virus. The patients were otherwise healthy, with no pre-existing conditions.

Researchers wanted to see if a specific type of antibodies that are produced when a person’s immune system incorrectly attacks itself were present in those recovering from COVID-19, and whether these antinuclear antibodies (ANAs)—which are associated with autoimmune disorders—were associated with the development of long COVID in patients.

They found that compared with an age and sex matched control group, those with COVID-19 had more ANAs in their body at three months post-recovery.

The number of ANAs decreased with time between the three and 12 months among the COVID-19 patients in general. But those who were still reporting persistent fatigue, severe cough or shortness of breath were more likely to have higher levels of ANAs still within them.

Mukherjee said in the release that those struggling with long COVID that persists for a year or longer should see a rheumatologist because of their expertise with autoimmune disorders. Currently, due to the lack of knowledge surrounding long COVID, many patients are likely seeking help from respirologists or infectious disease specialists alone, she said, but the issue may need more specialized help if it is persisting.

“Sometimes, while the body is fighting the virus, the immune system gets so amped up that, in addition to making antibodies that kill the virus, it can produce those that attack the host,” Mukherjee said.

“However, the general tendency of the body after it fights a severe virus like SARS-CoV-2 is to recover, and it’s often paced out varying from individual to individual.”

The fact that the continuing presence of high levels of ANAs within patients at 12 months was associated with persisting symptoms and inflammation suggests that the role of autoimmunity in long COVID needs more attention, the study states.

In order to look into it further, Mukherjee is leading the upcoming ‘Autoimmunity in Post-Acute COVID Syndrome’ study, which is being funded by the federal government. This study is currently recruiting participants, as is the Canadian Respiratory Research Network Long COVID study.