These days our society seems to need to pack everyone into tidy little groups based on whatever the latest internet memes dictate. One group getting lots of social media attention lately is “alpha males.” That carries all kinds of meanings, good and bad, depending on who’s doing the postings and who’s scrolling. There’s another group that doesn’t get all that much attention, “alpha gals,” which also carries a particular kind of importance to lots of people out there in the cyber universe; exactly what the importance is seems very individually determined. There’s something else about alpha gals that’s not what you might have considered, so no matter where you are on the continuum it’s important to us as pilots—so read on.
A few weeks ago, a cardiology colleague whom I respect and know to be a really smart, perceptive physician called me from the Emergency Department (ED) to see if I had any thoughts on a patient who had everyone a bit stumped. The patient was a generally vigorous and healthy 46-year-old woman who was brought into the ED by a co-worker after fainting in her office. She had a blood pressure nearing the level of shock, only 70 systolic, and her heart rate was up in the 130s. The ED docs were pushing liters of IV fluids and even an epinephrine infusion to try and get her blood pressure up but nothing was working. Her physical exam and lab work were all normal, except for her blood pressure. She had a cardiac echo that showed normal, vigorous heart function and her EKG was normal. She had no complaints of chest pain or shortness of breath that would go along with an acute cardiac event and no neurological changes that might point to a stroke. “What do you think is going on here?” my friend asked. I had no idea but I was interested in the questions the nurses were asking. The only thing the patient could report was having gone to a “potluck” holiday dinner at the office the evening before but wasn’t sure what some of the dishes contained. One thing I’ve learned after a lot of years practicing medicine is to listen to the patient; sometimes they know more than the docs. “Maybe I ate something that I’m allergic to. I have a lot of allergies,” she offered. The patient was right; she had an allergy to something she ate.
There wasn’t much that could be done for her except admit her to the ICU, monitor her vital signs, and treat the symptoms. The next day I was walking through the unit and saw my friend with the patient, who was sitting in a chair, chatting away. She looked great and had totally normal blood pressure and heart rate. Before I could even ask, he told me that the patient was now fine, she’s “an alpha gal.” I struggled to put that into some context from all the social media buzz but it didn’t match up, and I’m sure he could read the blank look on my face so he elaborated: “She has alpha-gal syndrome, she tested positive.” I tried to avoid saying anything too ignorant, just muttered, “Oh yeah, of course,” and snuck around the corner, pulled out my phone, and started to read up on it. I remembered some of it from the distant past but not the details.
Alpha-gal syndrome (AGS) has been around for a while and is getting more common even though it doesn’t get much media attention. It’s an underrecognized, tick-borne allergic condition that has real consequences for our cardiovascular health and safety in the sky. The name comes from one of those medical things with lots of syllables, “oligosaccharide galactose-alpha-1,3-galactose,” fortunately condensed to “alpha-gal (AG).” This stuff is a complex carbohydrate found in most mammals (like cattle and pigs) but not present in us humans. You can’t get sensitized just by eating red meat, you can only get AG into your system from tick bites, most commonly from the lone star tick and the blacklegged tick. If you get bitten by one of these little guys you have about a 30% chance that your immune system will make antibodies to it and sensitize you to further exposure to the alpha-gal sugar, from then on making you allergic to red meat. After you form the antibodies, you can come down with an AG syndrome reaction by eating almost any kind of red meat that all have this compound in them. It can set off a severe allergic reaction that triggers anaphylactic shock, critically low blood pressure, and even heart attacks or stroke. It fit the story of my friend’s patient, who lived out west near Lake Okeechobee in a rural area and did a lot of work out in the woods on her property. She had gotten multiple tick bites over the last few weeks.
Alpha-gal syndrome cases have exploded in the last 10-15 years; the number of reported cases has risen to over half a million, according to the CDC. This allergy seems to be increasing because tick bites are more common than they used to be due to more contact with the primary vector for lone star ticks, white-tailed deer. This pattern follows building and development into previously low-intensity areas as humans encroach on deer and tick habitats. Another study published earlier this year in the CDC’s Emerging Infectious Diseases documented other vectors like deer ticks that also carry the alpha-gal allergen, which further expands human exposure. It’s a common cause of severe allergic symptoms, and almost 10% of patients who present to emergency rooms with anaphylactic shock have alpha-gal syndrome. The most insidious risk of AGS to us pilots is that the onset is frequently delayed, just like in my friend’s patient; sometimes it takes 6–8 hours after exposure before symptoms of shock set in. That means that you can go out for a steak in the evening but not get really sick until the next morning in the cockpit. Or you could take off for one of those great Saturday morning $100 hamburgers (probably more like $500 these days) and go into shock in the air on the trip home.
Another important thing for us is that it turns out the alpha-gal also promotes early coronary artery disease (CAD), and patients with AGS are almost ten times more likely to have early onset CAD. These long-term risks of accelerated coronary artery disease were highlighted in a review published in The Journal of the American College of Cardiology a few months ago. Their study of patients undergoing coronary catheterization with alpha-gal–specific immune proteins found “significantly greater arteriosclerosis and high-risk plaque morphology, including increased calcification, fibrofatty content and necrotic core volume.” This is fancy language, but unstable calcium deposits in the coronary arteries are highly predictive of getting a heart attack. The association was especially common in younger patients ≤65 years, indicating an acceleration of atherosclerosis in immune-sensitized individuals. More confirmation comes from an Australian study that showed “α-Gal sensitization was independently associated with unstable coronary artery plaque burden, obstructive CAD and higher rates of heart attacks even in patients with no known heart disease.” Putting this together, these studies suggest that chronic immune activation from alpha-gal exposure is a factor in promoting vascular inflammation leading to heart disease, another big concern for us pilots renewing our medical certificates.
There are some things you can do about alpha-gal risks if you live in a rural area where ticks are endemic or you’ve been out in the woods hunting or fishing. First, make sure you check for ticks and get rid of them on your clothes or skin. The antibody you make when exposed to alpha-gal is an ‘E’ type immunoglobulin (IgE), and the CDC has a good review that details commercially available blood tests and skin tests you can get to find out if you’ve been sensitized. You usually don’t even need a doc’s order to get the test but it’s still better to discuss it with your family doctor. The implications for us as pilots are clear. Getting a severe allergic reaction or even anaphylactic shock in the cockpit is totally incapacitating and risks your life along with everyone else in your airplane. There’s an old 16th-century Latin saying, praemonitus, praemunitus, which translates to “forewarned is forearmed.” So, if you know you’ve had a few tick bites or you’re one of those folks sensitized to AG, you might have to adjust your diet and outdoor habits. And as always, FLY SAFE!
