Studies May Have Found Key to Peanut Allergies

Some kids with allergies may someday be able to dig into peanut butter. Elena Demyanko/Shutterstock

Talk to people in their 40s, and they will likely remember kids who brought peanut butter sandwiches to school. Ask many parents today, and they’ll tell you peanuts aren’t even allowed in the cafeteria.

Food-related allergies have been on the rise for years. Some kids have mild reactions and, for some, peanut allergies are life-threatening. According to the U.S. Centers for Disease Control and Prevention (CDC), food allergies among children increased by 18 percent between 1997 and 2007, and food-related allergic reactions have become the most common cause of anaphylaxis in community-health settings.

An experimental treatment from a California-based drug company seemed to have found some success in clinical trials. In studies, Aimmune Therapeutics gave 500 kids with severe peanut allergies capsules filled with gradually escalating amounts of peanut flour for a period of six months. Then, the children were given 300 milligrams a day for the next six months as part of maintenance therapy. The theory is that exposing people to small doses of peanut protein over time will gradually increase their tolerance.

In this 2018 trial, Aimmune said 67 percent of the participants were able to tolerate the equivalent of about two peanuts by the end of the study. About 20 percent dropped out of the trial and 12 percent were due to treatment-related issues.

The company expects to file for U.S. Food and Drug Administration approval by the end of 2018, and for approval in Europe in early 2019.

Earlier peanut studies

This is just one of several studies focused on gradually developing tolerance.

A 2017 study by researchers at the Murdoch Childrens Research Institute in Australia shows that two-thirds of the 48 children enrolled in a small clinical trial who received an experimental immunotherapy treatment were cured of their allergy, and the results lasted for four years.

“These children had been eating peanut freely in their diet without having to follow any particular program of peanut intake in the years after treatment was completed,” lead researcher Professor Mimi Tang said in a press release. The results suggest "the exciting possibility that tolerance is a realistic target for treating food allergy. This is a major step forward in identifying an effective treatment to address the food allergy problem in Western societies,” Tang said.

Tang is an immunologist and an allergist who developed a new treatment that combines probiotics with peanut oral immunotherapy (PPOIT). Instead of avoiding peanuts, people with such an allergy take the peanut-protein-laced probiotic to gradually develop a tolerance to peanuts.

Peanuts plus probiotics

The results are a follow-up to a 2015 clinical trial from the same researchers in Australia, where 28 children with peanut allergies were given daily doses of the probiotic Lactobacillus rhamnosus in combination with peanut protein. The amount of probiotic stayed the same while the dose of peanut protein increased over time until the children were receiving two grams a day.

By the end of the trial, more than 80 percent of the children who received treatment (and not the placebo) were able to include peanuts in their diet.

"In the study the combined delivery of probiotic and oral immunotherapy was a safe and effective treatment for peanut allergy,” Tang said of the findings. “However, it is important to point out that this treatment must be only be given under close medical supervision as we are giving peanut[s] to children who are allergic to peanut[s], and children did have allergic reactions. Nevertheless, the likelihood of success was high — if nine children were given probiotic and peanut therapy, seven would benefit."

Tang added, "It appears that we have been able to modify the allergic response to peanut such that the immune system produces protective responses rather than a harmful response to the peanut protein."

Gradual prevention

The Australian team's use of gradually introducing peanuts into a child's diet to ward off an allergic reaction is a process now recommended by the U.S. National Institute of Allergy and Infectious Diseases (NIAID), a center that is part of the National Institutes of Health.

The panel recommended three guidelines based on a child's risk factor for developing peanut allergies. Those infants at the highest risk, meaning they're already showing signs of severe ezcema or allergy, should receive peanut-containing foods as early as 4 to 6 months of age in reduce their risk factor. Those with a medium risk should wait until 6 months to have peanut foods introduced at 6 months old. Infants who do not display any signs of an allergic reaction should eat as much peanut food as parents and doctors see fit.

NIAID made these recommendations based on studies that have suggested early exposure to peanuts can reduce allergy risk. While the Australian study above was not cited, a study from the New England Journal of Medicine published in February 2015 "showed that regular peanut consumption begun in infancy and continued until 5 years of age led to an 81 percent reduction in development of peanut allergy in infants deemed at high risk."