Immune-Targeted Treatment Might Help Prevent Peanut Allergy Crises
Allergic reactions to peanuts can be incredibly dangerous, causing the throat to close, the chest to tighten, and throw a person into life-threatening anaphylactic shock.
But researchers now believe they've found a way to head off that immune reaction by blocking the antibodies that cause it.
There appear to be two specific allergens in peanut proteins that produce the most violent reaction from the immune system, according to the study.
A medication created to block the immune system from recognizing those allergens appeared to eliminate allergic reaction to peanuts in laboratory blood tests, researchers reported.
"Antibodies will interact with our inhibitors, and our inhibitors will not trigger the allergic reaction, it will just block the antibodies," explained senior researcher Basar Bilgicer. He's an associate professor of chemical and biomolecular engineering with the University of Notre Dame in Indiana.
It has yet to be tested in human clinical trials, but the drug could be a step up from medications like the EpiPen and antihistamines, which only subdue symptoms once the reaction has started, Bilgicer said.
Food allergies occur when a person's immune system recognizes the food as a potential threat to the body and overreacts in response.
Science has started to examine how immune antibodies interact with food to produce these reactions, Bilgicer explained.
In this case, Bilgicer and his research team took blood from 16 patients who are allergic to peanuts and started testing their antibodies to find which peanut allergens create the worst immune response.
The researchers identified two allergens that appear to be the main culprits, and then created a drug that would attach to the parts of a person's allergy-specific antibodies that interact with peanuts.
The new medication blocked allergic response in the blood of 14 of the 16 patients, researchers reported.
"It's very specific and only blocks those antibodies that are responsible for the allergic reaction," Bilgicer said. "It doesn't interfere with any other immune system responses."
The drug they've created could wind up as a pill or monthly injection people would take to ward off their peanut allergy, Bilgicer said.
It also could be used to help patients receiving immunotherapy, which involves exposing them to small amounts of peanuts to gradually reduce their immune response.
"Some patients are so allergic they are not eligible for undergoing immunotherapy," Bilgicer said. "Potentially, this could be used in combination with immunotherapy to desensitize those patients and get rid of the allergic condition for good."
The study was published April 8 in Proceedings of the National Academy of Sciences.
Allergy experts called the new research "exciting."
"Something like this, which seems to be going to where the problem occurs at the level of the recognition of the allergen, is an exciting thing," said Dr. Punita Ponda. She's assistant chief of allergy and immunology at Northwell Health in Great Neck, N.Y.
But right now this has only been tested in the lab, and Ponda said the complexity of the human immune system could create unpredictable problems in clinical trials.
For example, the immune system contains many redundancies, so blocking these specific immune receptors might cause the immune system to become more sensitive to other antigens in peanuts, Ponda said.
"We have to wait and see," Ponda said. "I think what I'm saying is, it's exciting but let's not count our chickens before they're hatched."
Dr. Edwin Kim, an assistant professor of medicine with the University of North Carolina, said he's curious how this approach might be used to help people with multiple food allergies.
He's also interested in how the immune system would respond to such a therapy long-term.
"Say you can successfully treat for a year," Kim said. "Is there some sort of feedback mechanism or something that tells the immune system, OK, look, nothing's happening, you can dial yourself down, and get a lasting effect that way? That would be pretty exciting to see."
Bilgicer said his team is now looking for funding that would allow them to pursue clinical trials.
The American College of Allergy, Asthma and Immunology has more about food allergies.
SOURCES: Basar Bilgicer, Ph.D., associate professor, chemical and bimolecular engineering, University of Notre Dame, Indiana; Punita Ponda, M.D., assistant chief, allergy and immunology, Northwell Health, Great Neck, N.Y.; Edwin Kim, M.D., assistant professor, medicine, University of North Carolina, Chapel Hill; April 8, 2019, Proceedings of the National Academy of Sciences