By Lan Anh Le
Kari Nadeau, associate professor of pediatrics in the School of Medicine, uses a seemingly counterintuitive treatment for her young patients suffering from severe food allergies: giving them doses of the things that could kill them.
Nadeau has used this technique, called oral immunotherapy (OIT), in trials to desensitize children with multiple food allergies. In OIT, the patient swallows small amounts of an allergen, increasing the dosage over time until his or her body builds up a tolerance to it.
Until recently, the only solution for patients with severe food allergies was strict avoidance of the allergen. However, Nadeau’s work with OIT has provided a viable alternative to the traditional avoidance method, especially for children with life-threatening allergies.
According to Nadeau, the results of OIT’s preliminary trials have been promising.
“The three patients that I have been working with did what we had expected them to do,” Nadeau said. “Gradually, they ate more of the allergen than what they could originally eat, and eventually they have become desensitized.”
Desensitizing children with multiple allergies
A Feb. 2013 study in Pediatrics estimated that almost six million children in the United States — one in 13 kids — has a food allergy. According to the study, approximately 39 percent of these allergies cause severe reactions, making Nadeau’s task both more challenging and important.
“There are so many people with severe allergies, kids with multiple food allergies,” she reflected. “I am inspired by my patients to do this work.”
One of Nadeau’s patients is nine-year-old Tessa, who was severely allergic to milk, wheat, eggs, nuts, shellfish and multiple other foods when her mother, Kim Yates Grosso, approached Nadeau about possible treatments in 2009.
Before Tessa started OIT treatment in 2012, she and her family lived in constant fear of a life-threatening allergic reaction. Grosso said that the process of being desensitized to allergens was ultimately not just about “being able to eat a type of food.
“It’s more about diminishing the fear and threats that we used to have to face,” Grosso said. “At one point, Tessa had stopped eating and didn’t want to leave the house.”
After going through an accelerated process in a multi-allergen clinical study, Tessa can now safely eat many of the foods that were once forbidden.
“She has gone from the point where she almost died when milk got spilled on her skin to being a kid who can eat ice cream,” Grosso said. “She can eat 16 peanuts, 16 almonds and almost as much wheat as she wants.”
Like other patients, Tessa has to continue eating the allergens every day so that she does not become allergic again, though the ultimate goal is that she will no longer have to worry about a relapse.
“There’s a lot of hope,” Grosso said. “We just don’t know how long it would be until she can stop.”
Stanford Alliance for Food Allergy Research
According to Nadeau, her interest in the immune system stemmed from her experience suffering from asthma and allergies to molds and polluted water in the houseboat where she lived as a child.
She became involved in long-term work in immunology and allergies after discovering the close connection between asthma and allergies, and she founded the Stanford Alliance for Food Allergy Research (SAFAR) to consolidate a clinical research team in fighting food allergies.
According to Nadeau, SAFAR researchers focus on the nuances of the allergic condition, such as the link between food allergies and asthma, how tobacco and pollution affect the immune system and how one identical twin can have allergies while his or her sibling doesn’t. The researchers have also experimented with various treatment strategies.
“We look at different therapeutic methods, from having a patch on the skin or underneath the tongue, to swallowing the allergen to build resistance,” Nadeau said.
According to Rosa Bacchetta, a visiting lecturer in immunology and allergy who works with Nadeau, collaboration and discussion are common in Nadeau’s lab, and Nadeau often solicits advice from other members of the Stanford community.
“She is very expert in immunological techniques, but she also collaborates with many different groups here at Stanford,” Bacchetta said. “It’s really interesting to combine different ways of thinking, different technologies and different types of study in the work.”
Nadeau stressed that OIT is still in an experimental stage and said that though she is excited about the results of the trials thus far, she and her researchers have to be “extremely careful.”
“The patient might take that peanut and not have that reaction,” Nadeau said. “But after any one day without ingesting that peanut, their resistance might collapse, and they might have a reaction again. It’s not a cure because they have to maintain the dose of the allergen they eat every day.”
According to Nadeau, the next step in developing OIT includes conducting multiple studies with many more patients in order to improve diagnostics and make new therapies as safe and effective as possible.
Despite the room for further advances, Grosso said that Nadeau’s work with OIT has already significantly impacted many families with children that suffer from life-threatening allergies.
“She is an angel,” Grosso said about Nadeau. “She is the first doctor that has given families with food allergies hope. Working closely with Kari makes me more assured that my child is safe.”