Alpha-gal allergy has commonly been referred to as “the red meat” allergy, but doctors at the Vanderbilt Asthma, Sinus and Allergy Program (ASAP) helped uncover that not only red meat, but some medications, can contain alpha-gal.
Cosby Stone, MD, a fellow in the ASAP clinic, said recent patients have led researchers to take a deeper look into alpha-gal as not only as a food allergy, but a medication allergy.
“We at Vanderbilt are working with excellent collaborators to lead in these discoveries to figure out how to keep alpha-gal patients safe when taking their medications,” Stone said. “This list of medications that we are paying close attention to includes antibodies derived from animals, like rattlesnake anti-venom and certain cancer treatments like Cetuximab. It also included products that contain gelatin, like certain vaccines or gel-based products. Heart valves that are harvested from pigs and used to replace a failed valve have also been reported to cause reactions or a more rapid breakdown of the valve in alpha-gal allergic patients.”
Alpha-gal is short for Galactose-alpha-1,3-galactose, a carbohydrate molecule found in mammalian meats, of which beef, lamb and pork are the most common in the American diet. Alpha-gal syndrome is commonly contracted from being bitten by a tick, most typically the lone star tick.
This tick, which feeds on both humans and other animals, is likely to first feed on an animal, then bite a human, thereby exposing the person to alph-gal, which is found in the animal’s blood cells.
The human’s immune system then develops antibody molecules called IgE that are specific to the alpha gal allergen. Once this occurs, they are prone to have allergic reactions upon consumption of alpha-gal containing foods or ingestion of alpha-gal containing medications.
Vanderbilt Health allergists have diagnosed and are currently treating approximately 200 adult and pediatric patients with alpha-gal syndrome at VASAP, the Vanderbilt Pediatric Allergy and Immunology Clinic and the Veteran Affairs (VA) Hospital. The numbers have steadily increased over the years as more information becomes available and diagnoses are made.
Any meat from an animal that nurses its young with milk is potentially a source for alpha-gal, but in Tennessee, alpha-gal reactions usually occurs after eating beef, pork and lamb or venison products. Organ meats from mammals such as kidney or liver can sometimes provoke more severe reactions. Some patients also react to gelatins or even milk, but not every patient will do so.
The typical reaction to alpha-gal is a delayed anaphylaxis (a severe allergic reaction) three to six hours after exposure, which at one point made diagnosis difficult, because allergic reactions to other foods such as peanut typically begin the moment the food enters the mouth, Stone said.
Hives, swelling of the lips, eyes, tongue, throat, respiratory issues, vomiting, diarrhea, increased heart rate and low blood pressure are common reactions to alpha-gal. More rapid and severe reactions can occur when medications containing alpha-gal are given via injections that bypass the digestive tract.
“What is difficult is predicting which alpha-gal patients will react to which drugs, foods or treatments, because the reaction varies by the patient,” Stone said. “Some patients report reacting to alpha-gal in the context of beef, but not pork, dairy or gelatin, for example. At the same time, others will react to pork and not beef. Some alpha-gal allergic patients react to medicines or vaccines, and others do not. We don’t currently know how to predict which patients will react to which foods and drugs, and that is a major focus of our ongoing research.”
Alpha-gal research at VASAP has previously benefited from an NIH-funded study of medication allergies. Elizabeth Phillips, MD, the principal investigator, conducted the study, which allowed researchers to dig deeper into what triggers reactions in patients with alpha-gal and medication reactions, in collaboration with alpha-gal experts at the University of Virginia and University of North Carolina-Chapel Hill.
Two NIH-sponsored studies being conducted by Phillips and Scott Smith, MD, are currently open to accepting samples from patients with alpha-gal.
Current research is focused on allergy antibodies directed against alpha-gal and other foods to explore factors that might put an alpha-gal allergic person at higher risk for medication-related consequences.
“We are most interested in learning how to keep patients safe when taking medications and in understanding how the allergy antibodies made by alpha-gal allergic patients work to cause symptoms,” Stone said. “Patients who qualify for recruitment can participate by giving blood and genetic samples and keeping us in mind for future investigations.”
I believe I am an alpha-gal sufferer, allergic to only bovine products, sometimes gelatin and always beef and collagen. My reaction is delayed, 4-6 hours and I vomit for 24 straight hours. Due to the occasional accidental poisoning, I now don’t eat any land animals, to avoid that risk. I wish there were a way to not have these terrible reactions accidentally from collagen enhanced products, as that is becoming more frequent in the health industry lately.
I too have Alfa-gal, taking Pepcid AC and anti Itch generally takes care of it. Our sons also were bit by the tick that they say causes this reaction. Our oldest son went to the hospital and almost died from it, that said, he is back to eating meats that cause the problem, with now, no problem, the other son went to see a allergist and was told if he was going to eat meat that causes the reaction, just take Pepcid AC before eating the meats that caused the problem. He does and has no reaction. Me on the other hand I just quit eating Beef, pork, deer meat ect. I haven’t had a reaction in over a year. I want too eat beef and pork, and deer meat I just haven’t tried to risk it.
I have alpha gal lyme babesia to name a few
My total immune system has been compromised and body is always in state of inflammation I’ve has 2 anaphylactic episodes now carry epipen
I’m wondering if AG is causing my constant state of inflammation and numerous food allergies sensitivities I’ve never had bf I’m 55 years old
I Aldo have gout since the tick bite I don’t eat red nest nor drink abc I’m in medication to bring uric acid levels down but now it’s creeping back up since most recent bite.
I’m very interested in finding out if any of my medications are causing this to occur I’m gaining weight retaining fluid. Something ain’t right my body says just can’t figure it out
I was happy to see the post from James. I have been wondering for the past 2 months why I was always so itchy. I have lived with an irregular bowel for many years but when I started getting heartburn, I went to the gastroenterologist. When I answered affirmative on the tick bite question, she told me that she was going to test for Alpha gal antibodies. Mine turned out to be moderately high. Prior to my visit I did not know that you could have the allergy and not get violently ill after eating mammalian products!