A new treatment may be a safe and effective form of immunotherapy for children with peanut allergy, according to researchers at Duke University Medical Center and Massachusetts General Hospital. Currently, there are no treatments available for people with peanut allergy. The double-blind, placebo-controlled study, funded in part by NCCAM and published in The Journal of Allergy and Clinical Immunology, investigated the safety, clinical effectiveness, and immunologic changes with sublingual immunotherapy—a treatment that involves administering very small amounts of the allergen extract under a person’s tongue.
Researchers randomly assigned 18 children (ages 1 to 11 years) with known peanut allergy to receive either peanut sublingual immunotherapy or placebo. Participants in the peanut group received increased doses of peanut extract every 2 weeks for 6 months. Following each dose increase, participants continued the same daily dose at home. Once a maximum dose of 2,000 micrograms of peanut protein was reached, participants continued to take this daily maintenance dose at home for approximately 6 more months.
After a total of 12 months of sublingual immunotherapy, participants underwent a food challenge, which involved taking increasing doses of peanut protein in the form of peanut flour mixed with food. The food-challenge placebo consisted of oat flour mixed with food given in the same increments. Allergy skin prick tests were performed, and participants’ blood samples were taken at different points throughout the study.
The researchers found that the participants who had received peanut sublingual immunotherapy could safely consume 20 times more peanut protein than those who had received the placebo (1710 mg vs. 85 mg). This level of desensitization is clinically significant because it represents protection from accidental ingestion of peanut, which is often less than 100 mg (or one peanut). In addition, allergy skin prick tests showed a decreased allergic response to peanut in the treatment group. The blood tests showed immunologic changes in the treatment group, suggesting a significant change in allergic response.
The researchers concluded that these findings are promising, but more study is needed to determine whether sublingual immunotherapy can increase long-term tolerance to peanuts in children with peanut allergy.
Kim EH, Bird JA, Kulis M, et al. Sublingual immunotherapy for peanut allergy: clinical and immunologic evidence of desensitization. The Journal of Allergy and Clinical Immunology.; 127(3):640–646.2011