Oral immunotherapy promising for children with peanut allergy

Children with a history of immunoglobulin E mediated peanut allergy who received controlled exposure to peanut protein achieved desensitization to the allergen in the early phases of a double-blind, placebo-controlled trial conducted at Arkansas Children's Hospital and Duke University.

“Currently, we have no active therapy for peanut allergy,” said Stacie M. Jones, MD, associate professor of pediatrics at University of Arkansas for Medical Sciences and Arkansas Children’s Hospital, both in Little Rock, during the American Academy of Allergy and Immunology Annual Meeting held this week.

Data from the first double-blind food challenge conducted as part of the study indicated that five participants who received oral immunotherapy (n=125) tolerated 5,000 mg of peanut protein — equivalent to the amount found in about 16 peanuts — compared with five participants in the placebo group (n=6), who tolerated a median cumulative dose of 460 mg of protein — equivalent to the amount of about two peanuts.

With a target population of 45 participants, 29 children aged 1 to 16 years with peanut-specific IgE levels greater than 15 kU/L have been enrolled, 18 have completed the first treatment arm and have participated in a peanut challenge. Minimal allergic symptoms were reported among the 18 patients who tolerated the initial 6 mg escalation day dose and reached a total 4 g maintenance dose. These symptoms included itching, occasional mild hives and mild abdomen pain. Only one patient belonging to the placebo group required epinephrine.

“Ongoing treatment is certainly needed and planned within our study population to determine the effect of peanut oral immunotherapy on clinical tolerance induction,” Jones said. “Our future work in this study and others will focus on immunologic mechanisms associated with oral immunotherapy for peanut allergy.”– by Nicole Blazek

For more information:

Jones SM. #814. American Academy of Allergy, Asthma & Immunology Annual Meeting; Washington; March 13-17, 2009.

Oral immunotherapy is currently not a very practical intervention for children with severe peanut allergy, but it may be the only way to desensitize them to allergens. Studies like these require lots of children and take a lot of time and resources to complete. Although the American Academy of Pediatrics has recently changed its stance that food avoidance early in life is the best strategy for preventing food allergy, this topic is still controversial and I am leery of exposing children who have never experienced a reaction to potential allergens.

– Gary S. Rachelefsky, MD

Infectious Diseases in Children Editorial Board member

This is one of many similar trials on oral peanut immunotherapy. Basically the work right now has been to prove the concept that you can feed someone who is allergic to peanuts incremental doses and induce some limited tolerance. The challenge will be to recruit enough patients and do a widespread trial to make sure that this concept works, that it works safely and that it works for all levels of peanut allergy severity. The important thing to recognize is that this is not a cure, but an expansion of one’s tolerance. Eventually this may be a landmark study that hopefully paves the way for a potential treatment for what can be a devastating and lifelong allergy for certain individuals.
Click here to hear Dr. Greenhawt's perspective.

– Matthew Greenhawt, MD

Pediatric Allergist and Food Allergy Specialist
Atlanta, GA