We speak often of kids who are exquisitely allergic and react severely to the smallest allergenic bite. But allergists say many kids with a peanut allergy will only react with more allergen exposure. They have a higher threshold of reactivity.
Now, a novel study reveals that eating gradually increasing amounts of store-bought peanut butter can lead to an impressive level of desensitization for higher-threshold children with peanut allergy. In the study, patients on peanut butter oral immunotherapy (OIT) tolerated about three tablespoons of peanut butter in a final feeding challenge.
The trial, led by researchers at the Icahn School of Medicine at Mount Sinai in New York, involved children who at enrollment could safely eat at least one half a peanut.
By comparison, previous oral immunotherapy studies focus on patients who react at much lower doses of peanut. However, allergic children with the higher threshold must still avoid peanuts, notes Dr. Scott Sicherer, lead author of the study published in the journal NEJM Evidence.
“We wanted to focus on this group where one could ask if it is helpful to do a treatment or is better to leave things as they are,” says Sicherer, the director of the Jaffe Food Allergy Institute and chief of pediatric allergy at the Icahn School of Medicine at Mount Sinai.
The team decided to attempt peanut butter OIT for the less reactive group. “We were thrilled to find this treatment strategy was even more successful than we had anticipated,” says study co-lead Dr. Julie Wang, a professor of pediatrics at Mount Sinai and researcher at the Jaffe Institute.
Using peanut butter could make OIT more accessible to patients who fit the criteria. But Sicherer stresses that this is certainly not for everyone. There are risks, and medical supervision is a necessity.
Peanut Butter OIT Trial
“This whole process must be emphasized with, ‘Do not try this at home,’” he cautions. He says this must be supervised by an allergist.
The trial included 73 children ages 4 to 14 years old. Thirty-eight children were randomly assigned to the treatment group, while a control group of 35 kids continued to avoid peanut.
Each participant entered the study with an oral challenge to determine their personal reaction threshold. Patients reacted to between 443 mg and 5,043 mg of peanut protein. Sicherer explains that a peanut kernel is about 200 to 300 mg of protein, and a level teaspoon of peanut butter is around 1,100 mg (around 4 peanuts). As well, 300 mg is the common maintenance dose for peanut OIT.
The treatment group started with eating a 1/8 teaspoon of peanut butter. The daily dose was increased every eight weeks, until the children reached 1 tablespoon of peanut butter. Or, they had an equivalent amount of a different peanut product, such as candy. Each dose increase took place under medical supervision.
Sicherer explains that aversion to the taste of peanut butter can be an issue for children with the allergy. This is why equivalent amounts of various candies were allowed after a few dosing points were reached.
Thirty-two of the participants on peanut butter OIT took part in the final oral challenge. One hundred percent of them could tolerate 9 grams of peanut protein. Again, that’s having about 3 tablespoons of peanut butter, without reacting.
Thirty children in the peanut avoiding group also did the food challenge. Three of them (10 percent) tolerated that amount, as well, and are considered to have outgrown their allergy naturally.
Off Peanut Butter, Then Back On
The next phase of the peanut butter OIT study tested the lasting effect of the desensitization. Participants ate at least 2 tablespoons of peanut butter per week for 16 weeks. Then, they avoided peanuts for eight weeks.
After the peanut avoidance, 26 of the 30 children in treatment could still tolerate 9 grams of peanut protein in a final feeding test. “It was a nice relief seeing how durable the response was for most,” Sicherer says.
After that challenge, the researchers instructed study participants to keep eating peanut regularly. Sicherer says patients were told not to eat peanut like a medicine on a schedule, but to consume it as part of their diet. For instance, to eat a serving amount of peanuts, peanut butter or candy during the week. They were also told to avoid having weeks go by without peanut.
The study results are encouraging, especially with a low reaction rate to the peanut butter OIT.
Without treatment, those who have a higher threshold for peanut can still have severe symptoms if exposed to enough peanut. Yet, none of the study participants in the peanut-ingestion group had severe reactions during home dosing. One participant was given epinephrine during a medically supervised dosing visit.
The focus on peanut-allergic children with a high threshold could open up treatment options, says Dr. Jeanne Marrazzo. She is director of the National Institutes of Health’s National Institute of Allergy and Infectious Diseases. NIAID sponsored and funded the trial. Marrazzo said such a therapy could be “liberating for many of these children and their families.” NIAID adds that “the investigators want to learn if the same treatment strategy would work for food allergens other than peanuts.”
Effective, But Not ‘a Cure’
If an allergist were to consider peanut butter OIT as an alternative to avoidance for high-threshold patients, Sicherer says they would need to consider whether the approach is appropriate.
That determination would include a discussion with a family about the risks and benefits. Then there would be an oral challenge to determine the peanut threshold, and highly detailed supervision of the treatment, he says.
It is important to remember that there are risks involved. Children did have symptoms from treatment in the research, and strict medical supervision was in place through all trial phases. Researchers applied the usual rules for treatment with OIT, such as no exercise for a few hours after dosing, taking doses with a meal, and skipping doses if ill.
While the trial was a success, it indicates desensitization, not a cure for milder peanut allergy. “I would not use the term ‘cure’ as we have not studied it that way,” Sicherer says.
The tolerance has not yet been tested on a longer timeline, he also stresses. “This was one small study at one center and would benefit from validation in larger studies to learn more nuances.”
Still, the research is the first to focus on the less-reactive group and to look at outcomes from a randomized trial.
“These study results are very exciting and a huge step forward in personalizing food allergy treatment,” Sicherer says.
Related Reading:
FDA Greenlights Palforzia OIT for Toddlers with Peanut Allergy
‘Very Low-Dose’ Peanut Oral Immunotherapy Helps Desensitize
