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Radiolab

Return of Alpha Gal

56 min episode · 2 min read
·
Amy Pearl,Dan Pashman,Thomas Platts Mills

Episode

56 min

Read time

2 min

Topics

Science & Discovery

AI-Generated Summary

Key Takeaways

  • Alpha-gal allergy mechanism: Lone Star tick saliva delivers alpha-galactose sugar directly through skin, bypassing normal digestion. The skin's immune surveillance system mislabels alpha-gal as a pathogen. Subsequently, eating any non-primate mammal meat — beef, lamb, pork, goat — triggers delayed anaphylaxis typically appearing two to six hours after consumption, making diagnosis notoriously difficult.
  • Delayed reaction window: Alpha-gal syndrome reactions occur two to six hours post-consumption, unlike most food allergies that trigger within minutes. Anyone suspecting this allergy should track symptoms against meals eaten hours earlier, not immediately prior. Blood testing for alpha-gal IgE antibodies provides confirmation; levels above baseline indicate active sensitization requiring strict red meat avoidance.
  • Geographic risk mapping: Alpha-gal syndrome cases cluster in the southeastern and mid-Atlantic United States — Virginia, North Carolina, Arkansas, southern Missouri — mirroring the Lone Star tick's range. People in these regions who spend time outdoors, especially off-trail, carry elevated exposure risk. Performing thorough tick checks within two hours of outdoor activity reduces bite duration and sensitization probability.
  • GalSafe pig as food solution: Revivacore's FDA-approved GalSafe pig has the alpha-1,3-galactosyltransferase gene removed, eliminating alpha-gal from its tissue. This makes its pork theoretically safe for alpha-gal syndrome patients. The pig received FDA approval for both medical device applications and as a food source, representing the first regulatory pathway specifically addressing this tick-induced allergy through genetic modification.
  • Xenotransplantation breakthrough: NYU Langone surgeons successfully transplanted a GalSafe pig kidney into a human patient in 2021 as a proof-of-concept, with a second transplant occurring simultaneously. In March 2024, a living 62-year-old end-stage kidney disease patient received a pig kidney and survived two additional months. Roughly 90,000 people currently await kidneys in the US, making animal organ supply a viable research direction.

What It Covers

Radiolab traces how the Lone Star tick triggers alpha-gal syndrome — a sudden red meat allergy — through a mechanism discovered via a cancer drug, following producer Amy Pearl's personal diagnosis, and connecting to a genetically modified GalSafe pig now used in landmark human kidney transplants.

Key Questions Answered

  • Alpha-gal allergy mechanism: Lone Star tick saliva delivers alpha-galactose sugar directly through skin, bypassing normal digestion. The skin's immune surveillance system mislabels alpha-gal as a pathogen. Subsequently, eating any non-primate mammal meat — beef, lamb, pork, goat — triggers delayed anaphylaxis typically appearing two to six hours after consumption, making diagnosis notoriously difficult.
  • Delayed reaction window: Alpha-gal syndrome reactions occur two to six hours post-consumption, unlike most food allergies that trigger within minutes. Anyone suspecting this allergy should track symptoms against meals eaten hours earlier, not immediately prior. Blood testing for alpha-gal IgE antibodies provides confirmation; levels above baseline indicate active sensitization requiring strict red meat avoidance.
  • Geographic risk mapping: Alpha-gal syndrome cases cluster in the southeastern and mid-Atlantic United States — Virginia, North Carolina, Arkansas, southern Missouri — mirroring the Lone Star tick's range. People in these regions who spend time outdoors, especially off-trail, carry elevated exposure risk. Performing thorough tick checks within two hours of outdoor activity reduces bite duration and sensitization probability.
  • GalSafe pig as food solution: Revivacore's FDA-approved GalSafe pig has the alpha-1,3-galactosyltransferase gene removed, eliminating alpha-gal from its tissue. This makes its pork theoretically safe for alpha-gal syndrome patients. The pig received FDA approval for both medical device applications and as a food source, representing the first regulatory pathway specifically addressing this tick-induced allergy through genetic modification.
  • Xenotransplantation breakthrough: NYU Langone surgeons successfully transplanted a GalSafe pig kidney into a human patient in 2021 as a proof-of-concept, with a second transplant occurring simultaneously. In March 2024, a living 62-year-old end-stage kidney disease patient received a pig kidney and survived two additional months. Roughly 90,000 people currently await kidneys in the US, making animal organ supply a viable research direction.

Notable Moment

University of Virginia allergist Thomas Platts-Mills deliberately walked off-trail in the Blue Ridge Mountains, collected roughly 200 tick bites, then ate lamb chops months later — waking covered in hives, having self-induced the very meat allergy he had previously dismissed as medically impossible in his own patients.

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Episode Transcript

Radialab is supported by Progressive Insurance. Do you ever think about switching insurance companies to see if you could save some cash? Progressive makes it easy to see if you could save when you bundle your home and auto policies. Try it at progressive.com. Progressive Casualty Insurance Company and affiliates. Potential savings will vary. Not available in all states. Hello. It's Lulu. It's summer here in the Northern Hemisphere, which means the ticks the ticks are out. And also the barbecues are out. You know, hot dogs, hamburgers, ticks, and burning meat, which made me think of today's episode, which combines the two into a wildly eerie, scary, but perhaps hopeful, ethically complex tale. It's one of my all time favorite Radiolabs, and we're gonna play it for you today. It is ten years old. But lucky for you, it has a pretty thrilling scientific update at the end. So here we go. Yeah. Wait. Wait. You're listening. Okay. Alright. Okay. Alright. You're listening Listening. To Radiolab. Radiolab. From WNYC. Cousins. Yep. Rewind. Good? Okay. Is your mic on? Yeah. I'm getting... This is making me nervous. Maybe I should get my EpiPen. Are you allergic to radio greatness? Not that I know of. I haven't been really exposed to it yet. Anyway, let's go. Are we rolling? We're good? We're going? We are rolling. Okay. I'm Robert Krowlwitz. This is Radiolab. And today, we're gonna begin with a conversation between Dan Pashman Okay. Host of a podcast here at WNYC called The Sporkful. It's about food. And Amy Pearl. Amy. Yes. A digital producer here at the station who likes food. Mhmm. And the conversation they had was about something that happened to Amy, which she never expected, certainly didn't want, and yet it could happen to any of us at any time. So years ago, before any of this happened to you, just tell me what was your relationship with meat? My relationship with meat? Yeah. Well, you know how when you're little and your mom is like, you can have any special dinner for your birthday. My dinner was meatballs. And she was like, except meatballs are so hard to make, so it was pot roast. And then Peter... You know Peter Luger's? Famous steakhouse in Brooklyn. Yeah. I used to go there quite often, and I live there. And I have a Peter Luger credit card. So... Are those hard to get? I... You know, I don't I don't know how they give them out, but nobody seems to have one. I don't think they give them out anymore. But I mean, I was very into Peter Liquor. I was living in Williamsburg, and it just... It opened at, like, 01:00 every day, and you could just walk in at one. They had an amazing bar. There's no tablecloths on the table. These old German waiters, they bring out your porterhouse for three. They put a little plate upside down and then put the big platter …

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  • by Revivacore

    Revivacore's FDA-approved GalSafe pig has the alpha-1,3-galactosyltransferase gene removed, eliminating alpha-gal from its tissue. This makes its pork theoretically safe for alpha-gal syndrome patients.

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