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Scientists have long knownthat when it comes to allergic reactions, the IgE antibody is the main culprit.But a groundbreaking new study has found the gut plays a powerful role in theprocess. Researchers at Stanford University say their findings could not onlyhelp determine the root cause of allergies, but also lead to life-changingtreatments.

The California research teamused an endoscope to take tissue samples from the esophagus, stomach and smallintestine of 19 peanut-allergic people taking part in an oral immunotherapytrial. Then they closely examined those cells and compared them with ones foundin the blood.

According to study lead author Ramona Hoh, PhD, they found that peoples rapid response to allergens is due in part to a memory response thats contained in specific kinds of B cells in the gut. When those B cells encounter an antigen like peanut in a person with peanut allergy, they can switch into plasma cells and start pumping out reaction-inducing IgE antibodies.

So this may be how these IgE antibodies get produced so quickly, because theyre actually residing in the stomach and duodenum tissue, Hoh, a senior scientist in the department of pathology at Stanford University, told Allergic Living. She notes that the number of these IgE-producing cells was hundreds of times higher in the gut than whats typically found in the bloodstream.

Using genetic analysis, the researchers were also able to confirm that the cells were being made in the stomach and the duodenum of the small intestine. This showed they were not being generated elsewhere in the body, and then traveling to the gut.

Whats more, many of thepatients shared similar peanut-reactive IgE DNA sequences, which means theirimmune systems see peanut proteins in a similar way.

We think thats extremely interesting because with antibodies youre dealing with this hugely complex, diverse universe, study co-author Dr. Scott Boyd told Allergic Living. But if you look at enough people, you start to recognize the common patterns that are associated with the disease.

We think that may allow usto say whos a better candidate for a certain kind of treatment, for example,or may allow us to better distinguish who is just sensitized to the allergen,but may not react strongly if they eat it, said Boyd, the principalinvestigator at Stanford Medicines Scott Boyd Labratory for Human Immunology.

Titled Origins andclonal convergence of gastrointestinal IgE+ B cells in human peanut allergythe studywas published in the journal ScienceImmunology. While it focused on peanut allergy specifically, Hoh and Boydbelieve the process could be similar for other allergens.

We set out to study peanutallergy because of its high incidence in the population, says Boyd. But inprincipal, we could have done the same study for tree nut allergy or shellfishallergy or others, and we suspect that we would have had similar findings, thatthere would be a lot of these IgE-expressing B cells in the gut.

Hoh adds that the gut of a non-allergicperson looks decidedly different. That difference was most clear in thestomach and the stomach isnt really a tissue thats known to have a lot ofplasma cells or B cells of any type, she says. So it was a pretty dramaticfinding.

IgE is the main catalyst behind allergic reactions. When people have allergies to peanuts or other substances, they develop IgE antibodies that recognize the proteins and other components of those specific allergens. The IgE then binds to the surface of mast cells. With exposure to the allergen, those cells then release inflammatory substances such as histamine. These set off reactions that can range from swollen eyes to hives or digestive symptoms and, in more serious cases, anaphylaxis.

In people without allergies, B cells are most often involved with helping to protect against infectious disease. For example, if you get a vaccination for measles or mumps, the B cells get stimulated by the vaccine and pump disease-fighting antibodies into your blood cells.

By analyzing the B cells that produce the allergen-specific IgE, the Stanford team hoped to help find the root cause of allergies. Until now, researchers have been almost entirely restricted to looking at the cells they can detect in the blood of patients, because getting samples of tissues in the gut is extremely challenging. Their efforts paid off.

We know the human body iscomplicated, and a much bigger space than the blood alone. And there arecertain tissues, like those in the digestive system where, if someone has foodallergy, the reaction starts, says Boyd. And we had reason to suspect theremay be a whole separate aspect of the immune system thats localized to thetissues of the gut and the digestive system, and that those would be worthstudying.

Besides furthering the understanding of how allergic reactions work, Boyd and Hoh say the research could lead to better diagnosis, treatment and prevention. They raise the possibilty for treatments that could prevent the IgE antibodies from triggering reactions.

Boyd points to a recentstudy involving patients with cat allergies, in which participants weregiven a biologic drug that blocked the IgE response and significantly reduced theseverity of their allergic reactions. Theres no reason one couldnt try to dothe same thing for peanut allergy, says Boyd. It might be a bit morecomplicated because there are more allergen molecules involved, but it wouldseem like a viable thing to try.

In recent years, scientistshave developed a far greater understanding of the role the humanmicrobiome plays in the allergic process, and Boyd says theyre starting toreally hone in on potentially life-changing answers, which could lead totargeted treatments.

My guess is there are goingbe more new treatments approved for allergy, and things that might be moresuitable for one patient compared to another in the years ahead, says Boyd.So I think theres room for guarded optimism in patients who suffer from thesedisorders.

See the full study here.

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Groundbreaking Study Finds Peanut Allergy Likely Starts In The Gut - Allergic Living