Scientists report they’ve pinpointed which immune system cells trigger allergies. The discovery may someday lead to a blood test that improves treatment, they suggests. These cells “represent a common enemy to every allergic individual that we can now easily track,” said study author Erik Wambre. He’s an immunology researcher at Seattle’s Benaroya Research Institute at Virginia Mason.
Allergic reactions stem from an inappropriate immune response to usually benign substances such as mold, pollen or peanuts. In the United States, almost 50 million Americans have nasal allergies, and as many as 200 die from serious food allergies a year.'
According to Wambre, more “biomarkers” – signs of illness that can show up in tests – are needed to improve allergy detection and assess treatment. At the moment, doctors relay on skin pricks to test your reaction to allergy-causing substances, or use blood tests that show if your immune system reacts to certain substances, Wambre said.
But these tests aren’t always accurate, and there’s no accepted way to use the results to predict someone’s response to treatment affecting the immune system, he explained.
That’s where the blood test Wambre and his colleagues are developing comes in. The study authors report they’ve developed a way to detect so-called type 2 helper T-cells (TH2) that reveal if a person has an allergy, although it doesn’t specify to what substances.
“Up until now, we couldn’t easily identify the TH2 cells triggering allergies from the one protecting the body from parasites, bacteria or viruses,” Wambre said. But the researchers said they found a kind of “signature” on the cells that cause a reaction to common allergens such as peanut, grass pollen, mold, cat dander, tree pollen and dust mites.
Their study involved 80 patients with allergies and 34 without allergies. “These cells were present in every person with allergies and almost entirely absent from people who don’t have allergies,” Wambre said.
