What exactly is alpha-gal?

The cardboard sign behind the women outside a local grocery store seeming to scream its message: “Beware what you eat! ALPHA-GAL!” The couple in the doctor’s waiting room discussing their colleague’s panic over a recent alpha-gal diagnosis and their “expertise” based upon what they’d read online.

There has been an uptick in alpha-gal stories in major news outlets. Lately, it seems as if alpha-gal is all around us. But what exactly is it? And what do you do if you have it? To find out, we asked Dr. Erin McGintee, an allergy specialist at ENTAllergy Associates who has been treating Long Island residents with alpha-gal since 2011.

“Alpha-gal (galactose-alpha-1,3 galactose) is a carbohydrate expressed in the cells of all non-primate mammals. Humans, apes and Old World monkeys lack this gene product. Certain people may develop an allergy to alpha-gal after being bitten by a lone star tick. People with alpha-gal syndrome experience delayed allergic reactions (which may include breathing issues, gastro-intestinal issues, hives) after consuming mammalian meat. The reaction occurs two to six hours after eating meat, so a person may feel fine after eating, then have symptoms hours later.

Alpha-gal syndrome has been around for many years. I identified my first alpha-gal patient in 2011; currently, I have about 1200 patients with the allergy. Unlike Lyme disease, it is not an infection, so it isn’t contagious. It is an immune response that some people have to the saliva of the lone star tick.

Alpha-gal syndrome, AGS, is diagnosed when a patient provides a clinical history that sounds consistent with this allergy. The diagnosis is confirmed with an IgE blood test.

Lyme disease is a tick-borne infection that can be transmitted by the deer tick (also called the black-legged tick).  Other tick-borne illnesses that have been reported in Suffolk County include babesiosis, ehrlichiosis, Rocky Mountain spotted fever, anaplasmosis and Powassan virus. There have been some instances of alpha-gal transmission through a deer tick bite.

Alpha-gal is complicated because every case is different; it is “consistently inconsistent.” A patient with the allergy may not have a reaction to meat with every exposure. They’re more likely to have severe reactions if they have higher alpha-gal blood test numbers and if they eat large portions of meat or fattier cuts.

There is a wide range of allergy severity between patients, even within the same patient over time, because alpha-gal IgE antibody levels change over time, depending on whether the patient continues to get tick bites.

Some patients are even able to eat meat at times, while others with greater sensitivity may react to byproducts like dairy or gelatin. Most patients with AGS can tolerate these without issues, however, and only a small subset of patients will react to the small amount present in these byproducts.

Alpha-gal is also present in small amounts in some medications, as well, including those in liquid-gel form, Armour thyroid, heparin, some monoclonal antibodies, and small amounts in some vaccines. Fortunately, most medications contain only trace amounts of alpha-gal, therefore reactions are rare. Those with a positive alpha-gal diagnosis can still donate blood.

There are four main variables that determine the likelihood of someone reacting to alpha-gal, as well as the potential severity of the reaction: the alpha-gal IgE level; the alpha-gal IgE to total IgE ratio; the portion size of meat ingested; the fat content of the meat.

Patients are generally at lower risk for a severe reaction when their numbers are lower and if they stick with smaller portions and leaner cuts of meat. Fish and birds/poultry aren’t mammals, so their meat doesn’t cause these reactions.

There is, unfortunately, a wealth of information about alpha-gal syndrome out in the media right now. My issue with a lot of the information that is being posted on the internet and on alpha-gal support groups is that it is very extreme, often inaccurate, and suggests that alpha-gal is a ‘one-size-fits-all’ allergy, which couldn’t be further from the truth.

As an allergist who specializes in patients with AGS, I think education is important. Right now there is a lot of misunderstanding of AGS, both on the part of patients and even providers. I think because this allergy is getting more media attention, people are scared. They expect a worst-case scenario. This has led to patients asking to be tested for AGS when they don’t have symptoms.

Because there is a not insignificant risk of getting a false positive test result for this allergy, I would strongly recommend against routine testing in the absence of symptoms.

If someone has symptoms consistent with AGS, a test can be ordered right away; a test is unnecessary for someone having reactions to meat since they will have a positive alpha-gal IgE test and there’s no reason to send it and wait for the results.

For patients concerned about their risk of getting AGS after a lone star tick bite, or if they are seeking additional information about this allergy, I would recommend that they schedule an evaluation with an allergy specialist, ideally one who practices in an area where lone star ticks are prevalent.”