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Podcast Recap | Sawbones: Alpha-Gal Syndrome
In this podcast, hosts Dr. Sydnee McElroy and her partner, Justin McElroy, discuss the research that Dr. Thomas Platts-Mills conducted in the early 2000s with cancer drugs. He first began studying cetuximab reactions and discovered that the drug contained a sugar called alpha-gal, which caused allergic reactions. He also linked alpha-gal to red meat allergies caused by tick bites. His studies of immunology reshaped the understanding of allergies and their origins.
The discussion covers the unique way Dr. Platts-Mills approached his research, what kinds of ticks carry alpha-gal, and what this could mean for the future of medical advancements.
Podcast length: 40 minutes
5 Key Takeaways
1. Alpha-gal syndrome can be difficult to diagnose, and patients often experience delayed reactions to red meat, making it even more challenging.
It's unclear how many people have galactose-α-1,3-galactose, also known as alpha-gal syndrome. It's not a reportable illness, and it's challenging to diagnose. Although the process has improved with a simple blood test, that doesn’t mean the time it takes to diagnose a patient is short or easy. Listening to patients and their symptoms is crucial to diagnosing and supporting them.
It can be easy to dismiss patients when they complain of upset stomach or a strange rash they have after eating meat. And because this reaction doesn’t happen immediately after eating red meat, it’s hard to make the connection. The typical reaction time is from three to six hours.
2. The researcher who studied alpha-gal syndrome actually had it himself.
Dr. Platts-Mills studied this syndrome, trying to determine what caused the reaction. During his research, he ended up with alpha-gal syndrome, enabling him to understand it better and putting him in the position to empathize with patients having these allergic reactions. Having this syndrome himself helped him make the connection, which was later verified by other people who had it. It also gave him the opportunity to research the condition directly. "I'm covered in biopsy scars from doing research on myself," he has said.
3. To be considered at risk for alpha-gal syndrome, you must have been bitten by a tick carrying this carbohydrate.
Alpha-gal syndrome is rare and causes an allergic reaction to certain red meats. The red meat must contain the carbohydrate alpha-gal to drive the response. When a tick bites a mammal with this carbohydrate, it ingests alpha-gal. Then, it bites a human and injects the alpha-gal into them. Human bodies see this invader and send antibodies to it. The next time the invader enters the body, it causes a reaction. When individuals ingest red meat that contains alpha-gal, it causes the body to react similarly, but the response becomes more severe.
The main tick that seems to cause allergic reactions after eating red meat is the lone star tick. These ticks have been seen in about 17 countries and all continents except Antarctica. Clinicians in Australia and the U.S. will likely see alpha-gal syndrome more frequently. In the U.S., the southern states are generally more populated with ticks, making allergy rates higher in those areas.
4. Patients taking some chemo medications can react similarly to the drug as others do to red meat.
To start his research, Dr. Platts-Mills focused on why patients reacted to certain chemo drugs. He found that the sugar alpha-gal was an ingredient in some cancer drugs, like cetuximab, which was causing the reaction. The reactions to this medication weren't consistent, making it difficult to link it to anything specific. Alpha-gal syndrome is similar in that the amount of time between consuming red meat and having a reaction is so far apart that figuring out what causes the response becomes challenging.
5. The future of genetically engineered animals could mean that patients could still enjoy red meats that previously contained alpha-gal.
There are now genetically engineered pigs that don’t have alpha-gal in them, meaning those who suffer from alpha-gal syndrome can enjoy eating pork without worrying about having a reaction. More importantly, patients who need a heart valve replacement will have more options. They could have the option of a porcine valve from a genetically engineered pig rather than being forced to use a mechanical valve due to their allergy.
As researchers are able to isolate more allergens within different food sources and modify animals' genes, this process opens the door to a promising future in which patients can enjoy foods again without fear of their allergens.
Any views, thoughts, and opinions expressed in this podcast recap are solely that of the host and guests and do not reflect the views, opinions, policies, or position of epocrates and athenahealth.
Source:
McElroy, S., & McElroy, J. (Hosts). (2023, September 12). Sawbones: Alpha-gal syndrome [Audio podcast]. Sawbones: A Marital Tour of Misguided Medicine. https://maximumfun.org/episodes/sawbones/sawbones-alpha-gal-syndrome/