Cracking the meat-allergy mystery with the tick-bite link | Hacker News Reader

Cracking the meat-allergy mystery with the tick-bite link

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123 pointssohkamyung68 comments

This happened to me following a tick bite, and I spent a year not eating mammals of any kind. Not eating beef or steak or pork or lamb is surprisingly easy on the surface and the choices are better than they used to be. But it's amazing how many mammal products have snuck their way into our food chain underneath, and those were the hardest things to avoid. Gelatin in liquid medicine capsules, pork-fat as a soup additive, chicken wings fried in beef tallow, the list goes on and on. And explaining to people in restaurants that you can't eat mammals because you'll swell up and die six hours later gets you a lot of weird looks.

Mercifully, after a year of being absolutely clean, I got a clean bill of health from my allergist: no more alpha-gal proteins in my system, and I can now eat soup in a restaurant or order the wings without worrying I'll wake up choking to death later on. As a plus, I will say it improved my diet considerably and got me to think a lot about what I eat, so the experience was not without its benefits. That said, I wouldn't recommend the experience to anyone.

> And explaining to people in restaurants that you can't eat mammals because you'll swell up and die six hours later gets you a lot of weird looks.

It's worth spreading awareness that there are way, way more things that cause allergic reactions than is commonly known. As a kid I grew up thinking that only peanut butter could cause allergic reactions. Now I know someone who has fatal reactions to dairy products, another with fatal reactions to eggs, and others with less severe reactions to mint, coconut, mango, latex, spermicide (imagine the circumstances where you discover that one)...

The bottom line is, if someone tells you they have an allergy to something weird, just take their word for it.

I really wish more people would heed this. It's obnoxious, and I know people take advantage of it (and wish they wouldn't!) to claim allergies to things when they just don't like them. But it's just not worth playing with someone's health. I'm really lucky that people believed me when I told them I had to know what things were fried in or whether they'd used beef stock for that soup.

Exactly. There are people that are allergic to light, to water...you name it.

It's a vegan conspiracy !

So did your system actually just slowly clean up whatever was causing it to create these 'alpha-gal proteins'? We're they an initial immune system response?

As I understand it, it's an immune system response rather than an allergen: your body sees the alpha-gal proteins as an invader, and develops an immune-system response to kill them off. So if you don't stimulate antigen production for a while, your body "forgets" and stops reacting to it. The problem is that that timetable for "forgetting" is different for everyone—some people get over it fast, some people it fades, and some people it never changes and no one yet seems to understand why.

The allergist that treated me is one of the docs on several of the principal studies about it, and he's been seeing patients with this for the last 15-20 years. He said he's seen people that would react when Wendy's contaminated their fryer oil with a dropped hamburger, and one guy who's a dairy farmer that wouldn't react to his own cattle's products but would react to anything else. It's truly a weird reaction!

That first soup must have been a nervous experience!

Hah! I actually had to have the initial test at the allergist's office. He had me bring in two sausage biscuits and eat them at 8:30, and then they watched me in his office for six hours to make sure I didn't react.

I still felt nervous the first time I had a hamburger, though! :)

How juicy did that first bite taste after a year of abstinence?

It was SO GOOD. I made sure to get good biscuits for the test too—I figured if that was the only sausage I’d have for another year, I’d make it count.

How did you discover you had this allergy in the first place without dying?

By coming awfully close! I had a hamburger for dinner. An hour or two later, my ankles were itching fiercely and I assumed I'd run into some poison ivy while tending the yard, so I took some Benadryl (which may have saved my life). Around two in the morning, I woke covered in the worst hives I've ever seen--I looked like I'd been attacked by an alien life form. I slammed some more Benadryl, and then I passed out on the bathroom floor while talking to my wife, so she called 911. By the time the EMTs got there, my blood pressure was down in the 50s, and I was solidly in "how are you still conscious right now range". One ER visit later, I had an epi-pen and an allergist appointment. :)

I count myself VERY lucky, and doubly so to have a wife who'd done lots of allergy research and knew how to respond!

What's the reaction that would happen to you if you ate meat? How do you treat it if you accidentally ate some? Chicken was ok to eat? Why did it clear up after a year? Was it a year of medications or your body just dealt with it?

During that year, if I ate meat nothing would happen right away. Then the itching would start, from my ankles and working its way up as my whole body broke out in hives. After the first attack, I took it crazy seriously (discovering I had this involved going to the ER at 2 AM not breathing!), so the most that happened during that year was that I got some hives and then slammed a double-dose of Benadryl, which knocked it back (and knocked me out). Fortunately once I knew I had it, I could mostly avoid it, so the only times I had reactions were when I missed something (e.g. get a burrito and they accidentally slip a piece of beef in with the chicken). I carried an epi-pen for emergencies and a sheet of Benadryl tablets; never had to use the epi-pen (thank goodness!). No medications to take in the meantime, just dietary changes.

The protein that causes this is only produced by mammals, so chicken and fish were totally safe. Weirdly, primates don't produce it either, so my allergist joked that if I were into eating monkeys or cannibalism, I'd be totally fine!

They still don't know why it clears up in some people and not others--in some, it goes away in a matter of weeks, some people it can take a year or multiple years, and in others it never disappears at all. And having had it, I'm apparently susceptible to getting it again, so if I get another tick bite it could come back again.

This allergy is one of my big fears. I wasn’t aware that it could be fixed, is abstention what clears it up or is there some other procedure?

No fix for it that I've seen; just abstention and hoping it fades. I think they're doing some research on it, but messing with the body's immune system can be really bad mojo.

This is, like so many other stories, another glycobiology story in disguise! I had a great discussion with one of our collaborators about where we thought the alpha-Gal came from that is so antigenic.

Our rough hypothesis was that this is a microbiome related problem, and there’s now some kind of bacteria (or something else!) resident to ticks that produces this sugar. My bet is that the little beastie that produces this epitope has adapted to produce alpha-Gal to avoid detection by the immune system in other mammalian hosts. The tick is simply a delivery mechanism for the alpha-gal producing organism.

Here’s the thing though - I don’t quite get why we don’t know what is going on yet. We (probably) have genomes for the ticks, and we can guess (sort of ok) what sugars they can make. We can also do microbiomes to figure out which possible beasties are found in the saliva. I must be missing something big so as to explain why we’re not much closer to answers?

"We can also do microbiomes to figure out which possible beasties are found in the saliva. "

Good luck with that.

Ha, yes okay maybe just from their secretions may be a tad optimistic. However, there are some papers out there about the associated microbiota, although I have no idea if they just mushed the whole tick up to get enough material.

To give you an idea: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1279316/

"We are grossly ignorant of bacterial life on earth. Environmental microbiologists estimate that less than 2% of bacteria can be cultured in the laboratory. "

In the last 2-3 years, several sequencing labs have popped up that specialize in separating pathogen DNA from host DNA.

Presumably someone like the UCSF next-gen diagnostics lab could grind up a bunch of ticks and isolate the different DNA sources. They've done similar things with other animal pathogens.

Not sure that it is so easy. May be easier to go mRNA fishing. Diversa did this. I think now part of BASF.

I have red meat allergy (specifically stronger for beef). IgE present for that specific test and all.

I've always thought allergic people were over-reacting. I've never had any kind of allergies before, but when I grew up and travelled, I found out that I had this particular nasty reaction with my nose. At first I thought it was pollen allergy.

Now I understand more about allergies. This type of allergy has very little scientific materials to read about so I appreciate OP's link. I just want to know more about it: what made me turn from non-allergic to very-allergic suddenly? And why beef?

Allergies are very strange. The skin in my mouth falls off when I eat beans, and there is very little literature about that one either.

I have the same reaction to some spice (plus tongue blood blisters) and I cannot figure out which. Usually it's some poor-quality take away.

Sichuan Peppercorns[1] possibly? They're not used typically in Western cuisine even as a flavor enhancer, but they would appear in more authentic Eastern takeout and they have some weird chemistry going on with tongues.

[1]: https://www.thespruceeats.com/sichuan-peppercorn-info-694248

Could be, as I had it from some Asian takeaway. But I also get it from some cheap pizza.

Its strangeness contributes a lot to scepticism when first presented with it. I have to admit I had this "you're making it up" reaction to allergic people. I literally thought, when I was a kid, that nut-allergy is overblown, people who claim that they're allergic to X is actually just fussy eaters, etc. (Now I know better)

As an example, I have contact dermatitis (red rashes, itchy) when I wear leather watches. If the watch has a plastic band or metal band, then it's fine. But leather always does it for me.

Part of me is thinking: is this because it's made from a mammal's skin?

But another part of me is really thinking: am I taking this too far? Maybe it's something else?

The worst thing is there's no doctors that would confirm my hypothesis. Reading online the symptoms of people who have this type of allergy is very different (people always list irritated bowel or skin rashes after eating meat), whereas for me when I eat beef (or even just soup made by using beef bones), it's actually: hard to breathe, my nose runs constantly (and effusively! - I am always amazed at the volume of snot that I can produce during the allergic times)

I have this reaction with other types of meat as well, but chicken is fine. It made me think a lot about what I eat.

Since the reaction has been mild, I've been adventurous at times, when I really craved steaks. My doctor hearing about it afterwards was aghast: she said I should never, ever do that again and I might die.

And really the child in me is still thinking: is this overblown? Would I really die from it?

It's so frustrating not knowing -exactly- what can I do or not do. It either goes from: you're going to die, to OK pop these Desloratadine pills and you're going to be fine, to "I don't think it's allergies, you have -X disease-"

Leather is also cured in all sorts of nasty things.

I have a similar reaction to nickel jewellery/watches, even nickel guitar strings make my fingers blister more than cobalt strings.

The most common, fastest and cheapest leather making method is called chrome-tanning which uses chromium-sulfate, which is kind of a nasty chemical. Virtually all unnatural colored leather is made this way too (though most brown leather is dyed too).

Not that it really changes much for you, but it seems unlikely that it's specifically mammalian skin to blame (I would assume exotic leathers from non-mammal sources probably have the same effect for you) and you might actually be sensitive to the tanning chemicals or any of the other leather conditioners or dyes that the leather has absorbed.

I can't express how happy I am to learn this information, thank you!

Will definitely investigate from there and see if that's the cause.

Ooh, I get that with pepperoni, especially bad with the 'snack' type of pepperoni stick. Not other preserved meats, just pepperoni. I mentioned it to a doctor and they absolutely just sighed and said "Yeah, well, bodies are weird, maybe don't eat pepperoni then?".

Me too. I get it from eating too much beef jerky too. My theory is that I have a sensitivity to nitrates or nitrites.

The "nitrate free" stuff doesn't work either, because they really mean artificial-nitrate-free and they use a natural source of nitrate like celery.

> what made me turn from non-allergic to very-allergic suddenly?

Indeed, one day I took a Lemsip and then face swelled up and I developed a rash. I was suddenly allergic to an ingredient in it.

So you can be literally infected with vegetarianism now?

(brb writing a novel about a secret agent trying to stop a terrorist vegan organization from putting this in the water supply of new york city.)

Yep - this happened to a family member about 9 months ago.

Wasn't as straight forward as you might think to diagnose.

This seems to be the story with a lot of tick related illness. People come down with some random illness and they see doctor after doctor who runs a battery of tests that yield no results. Finally someone decides to run the test for Lyme Disease and lo and behold the results come back positive. Kris Kristofferson is a prime example. His doctors thought his memory loss was due to dementia, until a someone finally decided to test for Lyme Disease.

https://www.cbsnews.com/news/kris-kristofferson-misdiagnosed...

A childhood friend of my sister was always shorter and skinnier than her classmates, didn't really hit the same kind of growth spurt as they did. I think she also had some indicators of ADHD, and she did run out of energy rather quickly.

It turned out after quite some time that she had lyme disease, and once that was treated, she basically hit her growth spurt with back interest. It was honestly surprisingly how much of a change it made. She grew much taller, and now has a very active career as a musician and social activist, barely ever sitting still for very long.

Not true vegetarianism; just can't eat mammal-derived meat. Other animals are still fair game. (pun not intended, but I'll take it)

Primates are also fair game.

Chicken might be an easier obtainable answer.

Primates are mammals...

> Primates are mammals...

That don't produce alpha-gal, the glycan that generates this allergy.

If humans produced alpha-gal, negative selection would typically remove it as a possible ligand, and this would rarely happen.

Ah, gotcha. Well I won't be eating any primates, but that's interesting to know.

Biology is such a fascinating field.

You've got bizarre disease states, immunobiology (a vast field in its own right - B cells, immunoglobulins, antigens, amplification, negative selection, etc.), evolution, and even ecology.

Just in this one problem.

Is the sequel to that novel a story about women taking over the tech sector

That is... a surprisingly interesting idea. Maybe swap terrorists for a certain nationalist government aligned with a certain vegetarian-leaning religion?

Don't have a dog in this race, but doesn't that certain vegetarian-leaning religion also prohibit violence against human beings? How do the terrorists square such contradictions in their mind? And is that one of the many mysteries driving the narrative in GP's novel forward?

You'll not be surprised to hear that religions all have "national security exceptions" to their non-violence clauses. I offer as evidence: all the crazy religiously motivated violence perpetuated by any long living religions (the truly peaceful ones being beaten to death long ago).

This was apparently one of the story points in Fish to Mars by Peter Watts ( https://www.rifters.com/crawl/?p=8217 ).

NPR had a great episode about this! A lot of people that I grew up with had chronic fatigue. We lived in one of the most tick populated area in the US and the teachers will just let us roam the shrubs and trees when we were on school trips. I always wondered if the population suffered from under tested and diagnosed Lyme and Lone Star disease.

I personally know multiple people that became intolerant to beef after a tick bite, rather than all mammalian meat. The symptoms manifested as digestive stress: abdominal cramping, nausea, and diarrhea. The onset of symptoms might be delayed for minutes or hours.

In one case, the person started to lose ability to tolerate a wide variety of foods. Further investigation revealed some symptoms that seemed to be related to MTHFR mutations. Genetic analysis confirmed this. Prior to analysis, began supplementing with 5-methyltetrahydrofolate. This began to immediately improve symptoms and foods were able to be added back to the diet. This continue for some time and hit a wall. Eventually traditional Chinese medicine doctor prescribed some herbal supplements.

The person in question still avoids beef, but is otherwise back to their pre-tickbite diet and living a normal life after years of struggling.

So was it beef sensitivity or just a folate deficiency?

Something about the beef sensitivity (possibly caused by a confirmed tick bite) seemed to cause the situation to spiral into more food intolerances. Symptoms started to mimic others with an MTHFR mutation. That mutation results in less production of some enzyme that metabolizes folate into another form (eventually leading to the form I posted 5-something-or-other). Taking that supplement allows you to bypass the folate conversion metabolic pathway.

How does this all fit together? I'm not entirely sure, this is an emerging area of research, I can only share what worked for the person I know. This MTHFR business seems to be related to histamine levels as well, that methlylated folate seems to be used by the liver to metabolize histamine. This seems to be directly related to allergic immune responses.

Hypothesis: Most people can tolerate the small amount of immune response triggered by the a-gal protein. People with MTHFR mutations cannot. The exact causative pathway, TBD.

The α-gal story is one I continue to enjoy learning about. If you haven't listened to it yet, RadioLab has an excellent episode on the topic: https://www.wnycstudios.org/podcasts/radiolab/articles/alpha...

My mom's own experience is remarkably similar to this: repeated unexplained allergic reactions landing her in the ER, eventually blaming an additive in the meat after realizing that meat seemed to be the culprit, and finally a chance conversation with a paramedic leading to the actual cause: alpha-gal allergy caused by a lone star tick bite several years before.

Except she lives in Wisconsin, not Australia.

Happened to me as well (Tennessee), was really, really surprising and the reaction seemed to be mainly around less cooked meat. I stopped eating beef and most pork for a few years and then slowly reintroduced it, now there is no issue. This was about 10 years ago and lasted around 5 years.

Ah, that’s funny! We had traveled to TN somewhere around ten years ago, and assume that’s where she was bit. The lone star tick has apparently made it as far north as Wisconsin though.

Glad you’re over it now. My mom recently has had very small amounts of meat products without issue.

Meat is hypo-allergic and free of prions if you cook it enough. It should be black in the middle, white on the outside.

I wish they'd have gone into the research being done to combat alpha-gal meat allergies. Living in NC and loving meat, this concerns me.

Given that there are only 5000ish cases in a country of 300+ million, right now your odds are pretty good. Best to take precautions when you are in the woods because ticks have other nasty things they bring along which are also quite bad.

Treat outer garments, ground cloths, packs, and tents with Permethrin. Wear a DEET based insect repellent. Wear long sleeves and long pants to prevent tick attachment. When in the woods check yourself daily and remove any ticks that you find as soon as practicable. If you are with someone else, check each other as ticks most often attach in places that are warm e.g. skin folds and it is difficult to check all of your own without assistance. Use a smartphone camera if you are alone.

Most of my familiarity comes from Lyme disease but ticks that are removed within 12-24 hours are much less likely to spread Lyme disease. It is likely, but I do not have evidence to support this, that a similar fact is true for meat allergies.

I just recently did some literature research on this, it's definitely very interesting.

-The antigen causing the allergy is called alpha-gal (a glycan, i.e. a sugar based molecule, present on proteins) -Humans are one of the few mammals that do not produce Alpha-Gal natively

-IgG and IgM antibodies against Alpha-Gal are very common in healthy individuals even in high titers, however IgE (the type of antibody causing allergies) is rare

-For some unknown reason, tick bites induce IgE antibodies against Alpha-Gal (possible reasons are the frequency (you get stung several times over several years, like repeated booster shots) and the saliva of the tick causing Th-2 response (converting IgG to IgE excreting B-cells)

-There's a famous case of a therapeutic antibody against cancer (Cetuximab) that is produced in mouse cells (remember: mice produce alpha-gal) that causes anaphylactic shocks (meaning a strong allergic reaction)

My wife (a horse riding instructor who spends a lot of time outdoors) and I were talking about the severity of our reactions to tick bites.

We were thinking that a stronger reaction would mean removing them more quickly and be protective against Lyme disease and similar tick-borne diseases. Both of us thought that our reaction to ticks had gotten more severe over time and we were thinking that was a good thing.

This spring, unsurprisingly, I started spending a larger than normal portion of my time in the woods. I brought an uncomfortable number of (deer) ticks home in the spring and again in recent weeks. This is every bit or more frightening personally than Covid is. At this point I know every skin tag and mole on my body from doing thorough check downs every time I get home from hiking. In Pa. we have the East Stroudsberg U Tick Research Laboratory who will take a specimen of any tick found embedded or not and run a basic pathogen panel free. The few I've sent in have been clean but being familiar with my bestie's dad's experience with Lyme there's no chance I'm not being as proactive as possible.

I've lived near where my spouse and I moved for most of my life. The woods behind the house we currently live in are where I spent most of my childhood. Ticks are just part of the territory (many springs and seeps = many ticks).

I have never had problems with tick-borne illnesses.

We moved back here 14 years ago, and within one month my spouse was diagnosed with Lyme disease.

My theory is that I'm immune to it due to repeated tick exposure as a kid. Otherwise, it just doesn't make any sense.

I had the same experience after a couple of tick bites in northern Europe around 1990. It went away after a few years. It saved me from eating beef in the UK when they had Mad Cow disease so maybe it's a blessing in disguise.

That's an interesting way to diet too, forced vegan.

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