Oral immunotherapy shows promise for treating peanut allergies
Relief may be on the way for children with peanut allergies. Researchers have found that by desensitizing children with controlled doses of peanut protein at a young age and for an extended period, they can tolerate peanut exposures without allergic reactions.
Food allergies affect many children, with peanut allergies being the most prominent and recognized. Fears over accidental exposure have led some parents to homeschool their kids, despite the fact that many schools across the United States are now “peanut-free” zones.
Even safeguards such as banning peanuts from cafeterias may not keep children safe, however, with 19% reporting allergic events in spite of interventions.
To reduce the risk of life-threatening allergic reactions, researchers have been studying the use of oral immunotherapy to reduce sensitivity to peanut proteins, and a new report has shown the therapy to be 81% effective in preschool-aged children.
Wesley Burks, MD, Curnen Distinguished Professor, Department of Pediatrics, and executive dean at the University of North Carolina School of Medicine, Chapel Hill, led the study, and says although the outcomes from the study need to be further evaluated as the research group ages, peanut oral immunotherapy is a promising long-term treatment for children with peanut allergies.
“We would anticipate that any child with a peanut allergy could do this if the outcome is validated,” Burks says.
Peanut allergies affect between 1.5% to 3% of children globally, and exposures can be life threatening. An estimated 15 million Americans have food allergies—including 1 in 13 children, who are also most at risk of anaphylactic reactions.
The Centers for Disease Control and Prevention has estimated that food allergies among children rose 50% between 1997 and 2011, and the American Academy of Allergy, Asthma, and Immunology says that peanut allergies are the most prevalent in children. Some children grow out of food allergies as they age, but many children with peanut allergies also have allergies to other foods as well.
Although the development of food-specific immunoglobulin E (IgE) begins in infancy, expression is unstable for the first 2 years of life. By targeting newly diagnosed, young peanut-allergic children, Burks says the research team hoped to increase efficacy of the oral immunotherapy, interrupting the allergic process before it had a chance to fully mature.
The National Institutes of Health’s National Institute of Allergy and Infectious Diseases (NIAID) partially funded Burks’ study and affirms that about 80% of the preschool-aged study participants that took part in the peanut oral immunotherapy trial were successfully treated.
The study involved 40 children aged 9 to 36 months with peanut allergies who were randomly assigned to receive either low-dose (300 mg) or high-dose (3000 mg) administrations of peanut protein daily.
Peanut oral immunotherapy involves the ingestion of small, gradually increasing amounts of peanut protein each day. Both low-dose and high-dose amounts of protein were found to be safe and equally effective during the trial, according to NIAID.
The clinical trial lasted an average of 29 months, after which all peanut protein was avoided for 4 weeks. When reintroduced to peanuts after the 4-week hiatus, 80% of the study group had no allergic response to peanuts, both in the low-dose and high-dose groups.
Nearly all the participants in the study experienced some degree of adverse effects, mainly abdominal pain, but the goal of the study was to reduce extreme allergic reactions—such as anaphylaxis—in young children.
Overall, the treatment was well tolerated, according to the study. Allergic reactions related to oral immunotherapy occurred in 95% of the study participants, mainly during the build-up phase. The majority—85%—of the reactions were mild and mostly involved the gastrointestinal tract and upper airway. Another 15% of reactions were moderate and most often occurred in the low-dose group. A quarter of the allergic reactions required no treatment at all, and most others were treated with antihistamines alone. None of the cases required treatment with epinephrine, according to the report.
There is a chance that even oral immunotherapy can’t be tolerated in 20% of individuals with peanut allergies, and there is high potential for relapse if treatment is interrupted, according to the study.
It’s also possible that some of the children in the study group grew out of their allergy naturally, although it’s unlikely. Only a small majority of children—perhaps around 22%—grow out of their peanut allergies naturally, according to the report.
Researchers will continue to monitor the study group to see if the success of the clinical trial continues as the children age.
Long-term success with oral immunotherapy was associated with lower peanut-specific IgE levels in previous studies. In those studies, participants sustained their immunity 5 years after treatment with goal maintenance doses of 4 g of peanut protein daily.
Burks also stresses that, despite the seemingly simplistic nature of this therapy, this is not an intervention parents should attempt at home. “There are too many normal allergic side effects,” he says.
The Immune Tolerance Network, supported by NIAID, is currently conducting a similar clinical trial in peanut-allergic children aged 12 to 48 months. Participants will receive oral immunotherapy for 134 weeks, followed by a period of peanut avoidance for 26 weeks. The study is scheduled to be completed in September 2018.