Monday, September 07, 2015

Tick bite causing meat allergy? (alpha-gal oligosaccharide allergy)

When Emily saw repeated comments online about a tick bite causing allergies to red meat we first assumed it was a mass medical delusion.

Turns out the belief comes from a Vanderbilt University allergy researchers claims and a 2009 WaPo article.

… Scott Commins, an assistant professor of medicine and lead author of the U-Va. study published in the Journal of Allergy and Clinical Immunology, said that in susceptible people such as Newell, a tick bite that causes a significant skin reaction seems to trigger the production of an antibody that binds to a sugar present on meat called alpha-galactosidase, also known as alpha-gal. When a person who has the antibody eats meat, it triggers the release of histamine, which causes the allergic symptoms: hives, itching and, in the worst case, anaphylaxis.

But many questions remain unanswered, said Platts-Mills, whose research is continuing. His lab has collected data on more than 300 patients from across the country and abroad.

"We're sure ticks can do this," he said. "We're not sure they're the only cause." Nor do researchers know why anaphylaxis is so delayed or why only some people develop a problem after tick bites. They do know that the allergic reaction is dose-related: Eating a tiny amount of meat probably won't cause a serious reaction. A large steak will….

The University of Virginia’s Thomas Platts-Mills is pushing the tick theory — though a recent abstract (article is $40) equivocates (emphasis mine) ...

The alpha-gal story: Lessons learned from connecting the dots

Our recent work has identified a novel IgE antibody response to a mammalian oligosaccharide epitope, galactose-alpha-1,3-galactose (alpha-gal). IgE to alpha-gal has been associated with 2 distinct forms of anaphylaxis: (1) immediate-onset anaphylaxis during first exposure to intravenous cetuximab and (2) delayed-onset anaphylaxis 3 to 6 hours after ingestion of mammalian food products (eg, beef and pork). Results of our studies and those of others strongly suggest that tick bites are a cause, if not the only significant cause, of IgE antibody responses to alpha-gal in the southern, eastern, and central United States; Europe; Australia; and parts of Asia. 

So the belief that a tick bite is causing a meat allergy has a basis in at least newspaper reporting and at least one team’s publications.

From my literature search it’s not clear anyone but Plats-Mills and his collaborators are making the strong connection to tick bites, much less to the Lone Star tick. I’d file this one under “suspect”. Of course that means that if Plats-Mills is right about the tick connection he will be well rewarded.

I’d bet he isn’t.

5 comments:

ALPHA-GAL POSITIVE said...

I don't know about the tick causing Alpha-Gal Allergy and frankly I don't care. I have been diagnosed with a straightforward IGE blood test after an episode of near fatal anaphylaxis. This isn't some diagnosis based on anyone's subjective opinion, the blood test indicates that you either have it or you don't. There is no treatment, no cure, and it's Hell to live with. There are thousands of us suffering right now and you think it's a hoax? Do some research and don't assume anything as this allergy breaks all the rules you base your opinion on. I wouldn't wish Alpha-Gal on anyone but in your case...:)

JGF said...

Yes, my skepticism is about the ticks, not the reaction (though there is probably some question as to whether alpha-gal is the entire story).

ALPHA-GAL POSITIVE said...

Again, my concern is staying alive. I can state with certainty that an allergic reaction to Alpha-Gal is reality. The article and abstract you read are older information and that part about a "bit of meat causing a smaller reaction than ingesting a steak" is completely untrue and disproven years ago. I would strongly suggest you expand your knowledge as the statement about "two different types of the allergy" is confused and factually inaccurate. There is a good video on YouTube that explains the original discovery of the allergy in cancer patients using a mammal sourced form of chemo. I don't know that Alpha-Gal is the whole story but I do know that avoidance of mammal products prevents the reactions. Please do further research and don't spread judgements and misinformation.

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