Persistent ‘long-COVID’: Research suggests the immune system itself might be to blame

Nearly two years into the COVID-19 pandemic, researchers are still trying to understand the novel coronavirus, how it affects the human body, and why expression of its symptoms can vary from person to person.

One aspect of COVID-19 that continues to mystify is why some who contract the virus have persistent symptoms for months after the onset of infection.

Mercer Island’s Dr. Gordon Cohen appeared on Seattle’s Morning News to unpack new research coming out of the University of Arkansas to better understand “long COVID,” or “COVID long-haulers.”

“As many as 30% of COVID-19 patients actually experienced this ongoing fatigue,” Cohen said. “People describe brain fog, shortness of breath, and general un-wellness. The reason that this happens in this pretty high percentage of people who have had COVID is unclear.”

“The researchers at University of Arkansas looked at a group of people from both Arkansas and Oklahoma: 67 patients who had COVID,” Cohen continued. “They also looked at 13 patients who had no history of infection.”

“They found that there was an antibody that was produced late in the patients that had the long hauler COVID that worked against the body’s own angiotensin converting enzyme system,” Cohen noted. “That system is responsible for fluid regulation in our body and blood pressure regulation. It turns out that our body may produce auto antibodies in response to the COVID infection.”

He went on to contextualize the research and provide some insight into other, similar research that is being done on the intersection between auto antibodies and prolonged COVID symptoms.

“This isn’t entirely new because early on in the research that was being done on COVID, there was a paper that was published that was looking at auto antibodies as being responsible for people who got more sick from COVID versus those who got less sick,” Cohen clarified. “It’s not entirely brand new research, but it would be interesting to discover that there is an antibody that attacks a specific system in our body because that would open it up to potential treatments.”

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Cohen went on to clarify how a COVID-19 vaccine affects one’s susceptibility to “long COVID.”

“It theoretically is possible [for] people who got the vaccine, and it has happened in people who got the vaccine,” Cohen said. “But [for] people have gotten the vaccine, the incidence is dramatically less. It happens far, far, far less than a fraction of 1% of people who’ve gotten the vaccine.”

“It dramatically reduces the severity of the illness,” he continued. “It keeps people out of the hospital and it keeps them from dying. In theory, you could propose that the overall immune response is so dramatically reduced that even if there were this auto antibody that was produced, it wouldn’t be in significant enough quantities to cause any sort of symptoms. That’s why patients don’t get the long hauler COVID.”

“Now, the fact is that this has not entirely been proven yet,” Cohen cautioned. “This is just a theory that they’re working on, and it’s an observational study, but they’re taking the steps to try and answer the question because if they can’t answer, it does lead to therapies.”

He pointed out that persistent symptoms are not exclusive to COVID: There are other viruses that can inflame the auto immune response and lead to long-term health implications.

“There is a common sort of auto immune illness from getting a strep infection where … the antibodies that are produced actually attack your kidney and result in kidney failure,” Cohen said. “It’s that type of a thing where you have the infection, the body, the immune system develops antibodies to try and fight off the infection, but the antibodies that get produced actually turn on the body itself.”

He articulated his own theory as to why long-term symptoms only affect a subset of those infected, and how the at-risk population could potentially be identified.

“Early on there hasn’t been a tremendous amount of talk about this yet, but I speculated that there may be a genetic component to how sick you get,” Cohen noted. “We do know that with other infections, there is a genetic predisposition to getting certain infections, and it may turn out that we find that to be the case with COVID as well.”

“There are people who get very sick because they’re genetically predisposed, and there’s others who don’t get as sick because they’re not genetically predisposed,” Cohen continued. “And again, I’m speculating whether they say that there’s proof of that as of yet, but it is actually being looked into. It’s not science fiction that I’m talking about. If we ever got to the point that we understood that there was a genetic predisposition, then it is something that you could be tested for.”

“I think we’re a long way off of that,” Cohen finished. “Certainly, the discussion about the vaccine is a contemporary one, whereas genetic testing is something that is potentially years away because we haven’t even identified it as a possible etiology.”

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