SEATTLE - Allergies affect more than 50 million people in the United States and the number, according to researchers, is rising. It’s estimated by 2050 half the population will have an allergy.
Treating allergies often involves daily over-the-counter medication, but a groundbreaking discovery at the Benaroya Research Institute at Virginia Mason could mean a trajectory shift in treatment for allergy sufferers.
Researchers have discovered a single type of cell they say appears to drive all allergies, whether they are food allergies or environmental. The cell has a name TH2A. The discovery could mean that allergy suffers won’t have to rely on daily medicine to fight allergies.
An afternoon at the playground for mom Rachael Crickman and her six-year-old twin boys is about swinging in the sunshine. Like most moms out with kids, she packs snacks, but in Crickman’s bag are also EPI pens, lifesavers for her son Zephyr who has a life-threatening peanut allergy.
“They help you so you don’t die,” said Zephyr describing the use of EPI pens.
“He’s at a very young age to be in touch with his mortality. Something as simple as eating school lunch he shouldn’t have to be thinking about if I take a misstep and ingest this, I might die. I think that’s a heavyweight for a kid to have,” said Crickman.
A heavyweight that’s become the norm for the Crickman’s since they discovered Zephyr had a food allergy at nine months old.
“It’s not the type of vigilance I want to have, but we’re forced to have,” said Crickman. “Everything he eats, every product we pull from the shelves, we have become those parents where you scan the label and you look, and peanut is really ubiquitous, you don’t know until you can’t have it that there is peanut flour and peanut oil. He can have cashews but they might be dipped in peanut oil, so you really have to scrutinize every single object that we purchase," said Crickman.
It also means that Zephyr’s twin brother Zachary who doesn’t have a peanut allergy rarely eats them either.
Both boys donated blood to the Benaroya Research Institute where researchers are looking at how cells in people with allergies differ than those without.
Under the tissue culture hood at the Wambre laboratory, it’s a different kind of playground. Pipets and petri dishes, seven years of researching that’s led to a discovery hanging in the office.
“If you’re allergic, you have cells in this yellow square. If you are non-allergic, you don’t have those cells,” said Erik Wambre, PhD and research scientist at the BRI.
Wambre discovered the cell which he named TH2A. The cells could be used as biomarkers, or indicators that show whether a person has an allergy or is responding to allergy therapy.
TH2A shows to be a promising focal point driving all allergies.
“It’s a very good therapeutic target,” said Wambre.
Allergies are caused when the immune system detects an allergen such as pollen, peanuts or pet dander, and overreacts by producing antibodies to fight the allergens. The antibodies release histamine and other chemicals that can cause sneezing, life-threatening reactions and other symptoms.
“Now, If we can find way to stop those TH2A cells, the patient can benefit not just for peanut or walnut, but every allergy,” said Wambre.
TH2A is a key player in allergic response. Think of it as the target.
Wambre says he now has to figure out how to destroy that target to reduce or even eliminate the allergy.
“I really hope in the next 10 years we will find, and have FDA approved-drug that will destroy those cells,” said Wambre. “The best way, instead of taking those drugs, I hope you will take a few shots, or treatment until those cells disappear and maybe it will last longer than just the time of pollen season,” he said.
Dr. Wambre began this study seven years ago by examining a type of immune cell, Th2, which helps coordinate how the immune system responds to parasites, viruses and bacterial infections, but also leads to allergies. As Wambre and his colleagues analyzed the blood samples from BRI’s Allergy and Asthma Biorepositories containing these cells, they discovered a specialized subtype of cell, which they called Th2A, which is present in people with allergies but almost entirely absent from people who don’t have allergies.
As Wambre and his colleagues analyzed blood samples containing these cells, they discovered a specialized subtype of cell, which they called Th2A, which is present in people with allergies but almost entirely absent from people who don’t have allergies. The researchers found that, unlike normal Th2 cells, these Th2A cells lack expression of one key protein – called CD27 – while simultaneously expressing the CRTH2 and CD161 proteins – that lead the immune system to overreact to allergens.
“This indicates that the Th2A cells are more specialized than conventional Th2 cells – they’re tailored to help the body respond to allergens,” Wambre says.
Wambre and his colleagues performed tests to confirm that Th2A cells play a pivotal role in at least six common allergies – including peanut, grass pollen, mold, cat dander, tree pollen and dust mites.
The researchers examined Th2A cells in blood samples from people allergic to grass pollen. They found that the Th2A cells were activated during allergy season when they expressed larger amounts of CD38 – a protein that reflects activation following allergen exposure. CD38 was not expressed in conventional Th2 cells or outside of allergy season.
For the Crickman’s the new research could mean that Zephyr’s life would be a little easier and less scary when he’s simply at a lunch table filled with peanut butter and jelly sandwiches.
“It’s not that I want him to be able to eat a peanut butter sandwich, it’s just that I want to feel like if he has a little bit that he would be okay, and we could change the conversation and bring back some levity into things like eating,” said Crickman.
Wambre says the discovery is aimed at designing drugs to one day treat allergies instead of serving as a diagnostic tool, however, he says it could be used as a blood test for a baby to have and if it indicates presence of TH2A, then parents would know the child has an allergy and to be aware of it. The blood test wouldn’t be able to show which allergy, but that an allergic response is present in the child.