GOLDEN VALLEY, Minn. — Since the pandemic started, scientists have been plagued with why some people have severe COVID-19 and long-haul symptoms and others don't.
One theory gaining ground links a more-common-than-previously-thought immune disorder called Mast Cell Activation Syndrome (MCAS) with worse and extended COVID symptoms.
Dr. Lawrence Afrin, a hematologist and oncologist with the AIM Center for Personalized Medicine and a leading expert on MCAS, published a theory that if proven would unlock a great COVID mystery.
Mast cells are the first responders of your immune system. When an infection occurs, in under a second, these cells send compounds like histamine to other cells to say 'hey wake up, something is wrong here.'
In some people, those mast cells go haywire and overreact, like central dispatch calling in the SWAT team for a coffee spill at Starbucks. This is MCAS.
“This is a phenomenon that is much more common that we used to think,” said Afrin. “A lot of these [COVID] inflammatory issues aligned sort of well with the inflammatory issues we see in folks who have MCAS.”
The best estimates show about 17% of the first world population have some form of MCAS, according to Afrin. He noticed between 15 and 20% of COVID infections become severe.
COVID long-haulers can have symptoms ranging from neurological issues to heart issues to extreme fatigue, MCAS can have similar symptoms caused by widespread inflammation, Afrin noted.
So he and a few colleagues published a hypothesis in the International Journal of Infectious Diseases linking MCAS to severe and long-haul COVID.
Things got more interesting as COVID long-haulers came to see Dr. Afrin.
“When we ran the testing on them, we could show that, yes, they had MCAS and actually history suggests they had MCAS long before they became infected,” said Afrin.
When he gave the long-haulers treatment for their mast cell syndrome, he said the COVID symptoms started to go away.
The central idea here, that inflammation from MCAS could be what is causing long-term COVID problems, and a lot of people don't know it.
“It's an interesting hypothesis. A lot of things fit, but again association does not equal causation,” said Afrin.
He hopes his published theory will trigger the frontline researchers of COVID to clinically study possible links to MCAS and its associated treatments.