Thousands of people are developing life-threatening reactions to animal products – and a single tiny creature is to blame THE LONESTAR TICK>
By Maryn McKenna
It was early morning in early summer, and I was tracing my way through the woods of central North Carolina, steering cautiously around S-curves and braking hard when what looked like a small rise turned into a narrow bridge. I was on my way to meet Tami McGraw, who lives with her husband and the youngest of their kids in a sprawling development of old trees and wide lawns just south of Chapel Hill. Before I reached her, McGraw emailed. She wanted to feed me when I got there.
“Would you like to try emu?” she asked. “Or perhaps some duck?”
These are not normal breakfast offerings. But for years, nothing about McGraw’s life has been normal. She cannot eat beef or pork, or drink milk or eat cheese or snack on a gelatine-containing dessert without feeling her throat close and her blood pressure drop. Wearing a wool sweater raises hives on her skin; inhaling the fumes of bacon sizzling on a stove will knock her to the ground. Everywhere she goes, she carries an array of tablets that can beat back an allergy attack, and an auto-injecting EpiPen that can jolt her system out of anaphylactic shock.
McGraw is allergic to the meat of mammals and everything else that comes from them: dairy products, wool and fibre, gelatine from their hooves, char from their bones. This syndrome affects thousands of people in the US and an uncertain but likely larger number worldwide, and after a decade of research, scientists have begun to understand what causes it. It is created by the bite of a tick, picked up on a hike or brushed against in a garden, or hitchhiking on the fur of a pet that was roaming outside.
The illness, which generally goes by the name “alpha-gal allergy” after the component of meat that triggers it, is a trial that McGraw and her family are still learning to cope with. In much the same way, medicine is grappling with it, too. Allergies occur when our immune systems perceive something that ought to be familiar as foreign. For scientists, alpha-gal is forcing a remapping of basic tenets of immunology: how allergies occur, how they are triggered, whom they put in danger and when.
For those affected, alpha-gal is transforming the landscapes they live in, turning the reliable comforts of home – the plants in their gardens, the food on their plates – into an uncertain terrain of risk.
People were reacting to the drug because they had a pre-existing sensitivity, indicated by a high level of antibodies (called immunoglobulin E, or IgE for short), to a sugar that is present in the muscles of most mammals, though not in humans or other primates. The name of the sugar was galactose-alpha-1,3-galactose, known for short as alpha-gal.
Alpha-gal is familiar to many scientists because it is responsible for an enduring disappointment: its tendency to trigger intense immune reactions is the reason that organs taken from animals have never successfully been transplanted into people. The puzzle was why the drug recipients were reacting to it. To have an allergic reaction, someone needs to have been primed with a prior exposure to a substance – but the trial recipients who reacted badly were all on their first dose of cetuximab.
Team members scrutinised the patients and their families for anything that could explain the problem. The reactions appeared regional – patients in Arkansas and North Carolina and Tennessee experienced the hypersensitivity, but ones in Boston and northern California did not. They investigated parasites, moulds and diseases that occur only in pockets of the US such as rural Tennessee.
The question then became: what in rural Tennessee could trigger a reaction like this? The answer arose from a second coincidence. Dr Jacob Hosen, a researcher in Platts-Mills’s lab, stumbled across a map drawn by the Centers for Disease Control and Prevention (CDC) showing the prevalence of an infection called Rocky Mountain spotted fever. It exactly overlapped the hot spots where the cetuximab reactions had occurred.
Rocky Mountain spotted fever is transmitted by the bite of a tick: Amblyomma americanum, one of the most common ticks in the south-eastern US. It’s known as the lone star tick because of the blotch of white that appears on the back of the female’s body.
https://www.theguardian.com/news/2018/dec/11/mysterious-allergy-to-meat-alpha-gal-lone-star-tick
By Maryn McKenna
It was early morning in early summer, and I was tracing my way through the woods of central North Carolina, steering cautiously around S-curves and braking hard when what looked like a small rise turned into a narrow bridge. I was on my way to meet Tami McGraw, who lives with her husband and the youngest of their kids in a sprawling development of old trees and wide lawns just south of Chapel Hill. Before I reached her, McGraw emailed. She wanted to feed me when I got there.
“Would you like to try emu?” she asked. “Or perhaps some duck?”
These are not normal breakfast offerings. But for years, nothing about McGraw’s life has been normal. She cannot eat beef or pork, or drink milk or eat cheese or snack on a gelatine-containing dessert without feeling her throat close and her blood pressure drop. Wearing a wool sweater raises hives on her skin; inhaling the fumes of bacon sizzling on a stove will knock her to the ground. Everywhere she goes, she carries an array of tablets that can beat back an allergy attack, and an auto-injecting EpiPen that can jolt her system out of anaphylactic shock.
McGraw is allergic to the meat of mammals and everything else that comes from them: dairy products, wool and fibre, gelatine from their hooves, char from their bones. This syndrome affects thousands of people in the US and an uncertain but likely larger number worldwide, and after a decade of research, scientists have begun to understand what causes it. It is created by the bite of a tick, picked up on a hike or brushed against in a garden, or hitchhiking on the fur of a pet that was roaming outside.
The illness, which generally goes by the name “alpha-gal allergy” after the component of meat that triggers it, is a trial that McGraw and her family are still learning to cope with. In much the same way, medicine is grappling with it, too. Allergies occur when our immune systems perceive something that ought to be familiar as foreign. For scientists, alpha-gal is forcing a remapping of basic tenets of immunology: how allergies occur, how they are triggered, whom they put in danger and when.
For those affected, alpha-gal is transforming the landscapes they live in, turning the reliable comforts of home – the plants in their gardens, the food on their plates – into an uncertain terrain of risk.
People were reacting to the drug because they had a pre-existing sensitivity, indicated by a high level of antibodies (called immunoglobulin E, or IgE for short), to a sugar that is present in the muscles of most mammals, though not in humans or other primates. The name of the sugar was galactose-alpha-1,3-galactose, known for short as alpha-gal.
Alpha-gal is familiar to many scientists because it is responsible for an enduring disappointment: its tendency to trigger intense immune reactions is the reason that organs taken from animals have never successfully been transplanted into people. The puzzle was why the drug recipients were reacting to it. To have an allergic reaction, someone needs to have been primed with a prior exposure to a substance – but the trial recipients who reacted badly were all on their first dose of cetuximab.
Team members scrutinised the patients and their families for anything that could explain the problem. The reactions appeared regional – patients in Arkansas and North Carolina and Tennessee experienced the hypersensitivity, but ones in Boston and northern California did not. They investigated parasites, moulds and diseases that occur only in pockets of the US such as rural Tennessee.
The question then became: what in rural Tennessee could trigger a reaction like this? The answer arose from a second coincidence. Dr Jacob Hosen, a researcher in Platts-Mills’s lab, stumbled across a map drawn by the Centers for Disease Control and Prevention (CDC) showing the prevalence of an infection called Rocky Mountain spotted fever. It exactly overlapped the hot spots where the cetuximab reactions had occurred.
Rocky Mountain spotted fever is transmitted by the bite of a tick: Amblyomma americanum, one of the most common ticks in the south-eastern US. It’s known as the lone star tick because of the blotch of white that appears on the back of the female’s body.
https://www.theguardian.com/news/2018/dec/11/mysterious-allergy-to-meat-alpha-gal-lone-star-tick
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I know that coffee, and it is the most acidic I've tasted - big stomach aches afterwards. The donuts are ok for about 15 minutes, then I feel them, too.