NEW ORLEANS – Two studies presented at the 2010 Annual Meeting of the American Academy of Allergy, Asthma & Immunology (AAAAI) examine the use of oral immunotherapy in peanut allergic children and continue to add hope that a treatment may be on the horizon.
Both were completed by researchers at Duke University and the University of Arkansas for Medical Sciences. In one, peanut allergic children were randomized to receive either the peanut oral immunotherapy or a placebo. The subjects went through initial escalation, build-up and maintenance dosing. This was then followed by an oral food challenge.
Twenty-three children reached the oral food challenge, 15 had received the oral immunotherapy and eight had received the placebo. During the oral food challenge, the median cumulative dose of peanut tolerated was only 315 mg for the placebo group compared to 5,000 mg (~15 peanuts) for the oral immunotherapy group. In addition, the oral immunotherapy group saw median titrated skin tests decrease from baseline to the oral food challenge.
Median peanut IgE and IgG4 levels were also measured. IgE levels did not change from baseline to the oral food challenge in either group, while IgG4 levels increased from baseline to the oral food challenge in the treatment group.
“We are encouraged by the results of this first blinded, placebo controlled study for oral peanut immunotherapy. The differences in the treatment and placebo group are significant and help guide us to the next studies,” said A. Wesley Burks, MD, FAAAAI, one of the study authors.
In the other study, the researchers looked to identify whether subjects who received the oral immunotherapy could safely ingest peanut after stopping the treatment.
Twelve peanut allergic children who completed all phases of oral immunotherapy, along with meeting certain clinical and laboratory criteria, participated in a final oral food challenge 4 weeks after they stopped receiving the oral immunotherapy. The amount of time the children received the oral immunotherapy ranged between 32 and 61 months.
Nine of the 12 subjects passed this final oral food challenge and now have peanut in their diets.
“We are now trying to identify characteristics in those subjects who were able to stop the therapy to better understand who might be a good candidate for this treatment,” commented Burks.
Over the course of the treatment, peanut IgE levels decreased from the baseline with IgG4 levels increasing. Titrated skin prick tests also decreased from the baseline. These immunologic changes support the development of tolerance.
The AAAAI (www.aaaai.org) represents allergists, asthma specialists, clinical immunologists, allied health professionals and others with a special interest in the research and treatment of allergic and immunologic diseases. Established in 1943, the AAAAI has nearly 6,500 members in the United States, Canada and 60 other countries. If you believe you may have a food allergy, consult with an allergist/immunologist. To find one in your area, visit www.aaaai.org/physref.