Monday, March 16, 2009

AAAAI: Oral Immunotherapy Beats Peanut Allergy in Some Children


AAAAI: American Academy of Allergy Asthma & Immunology Meeting

By John Gever, Senior Editor, MedPage Today
Published: March 16, 2009
Reviewed by Zalman S. Agus, MD; Emeritus Professor
University of Pennsylvania School of Medicine.
WASHINGTON, March 16 -- Five of nine peanut-allergic children undergoing long-term, steady exposure to small quantities of peanuts are now able to eat peanut products freely, a researcher said here.

The children, enrolled in an open-label trial of oral immunotherapy for peanut allergy, have been treated for at least 2.5 years, A. Wesley Burks, M.D., of Duke University, reported at the American Academy of Allergy, Asthma, and Immunology meeting here.

The findings provide a glimmer of hope for up to 3 million Americans who suffer from peanut allergies in a society where peanut products are ubiquitous. Action Points
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Explain to interested patients that peanut allergies in children usually persist into adulthood and can be life threatening.

Explain that only a small number of patients have been fully evaluated in this study, and the treatment should still be considered investigational.

Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
Peanut allergies are among the most common triggers of anaphylaxis, according to the AAAAI, and only one in five children with the allergy outgrows it in adulthood.

Currently, the standard treatment is avoidance of foods containing the legumes and keeping an epinephrine injector close by to deal with severe reactions.

In all, 39 children have participated in the ongoing study, which Dr. Burks characterized as an open-label pilot trial.

The ongoing study protocol -- with 33 currently enrolled -- began when children were two to five years old. They initially received tiny doses of peanut flour, less than one milligram.

The children took steadily increasing amounts of peanut until, eight to ten months later, they could tolerate up to 15 peanuts per day.

Treatment continued at that level, Dr. Burks said, with periodic challenges to confirm the youngsters' ability to tolerate peanut products.

The researchers -- including scientists at the University of Arkansas in Little Rock -- have determined that children successfully treated showed significantly decreased serum levels of peanut-specific immunoglobulin E.

Withdrawal of the immunotherapy has now begun to be tested in participants with very low peanut IgE, less than 2 kU/L.

Five of nine children who had been on treatment for at least 2.5 years passed an oral food challenge test. Researchers then stopped their immunotherapy for a month, followed by a second challenge test.

It was successful in all cases, Dr. Burks said, and the children now are under no diet restrictions and eat peanut-containing foods daily. "They are months out and they are doing fine," he said.

Biochemical studies in these children indicate that the therapy induced regulatory T cells and secretion of IL-10 indicative of tolerance to peanut proteins.

"They [immune cells] change to a nonallergic phenotype," Dr. Burks said.

Of the 39 total participants, six moved away and dropped out, and four withdrew because of allergic reactions.

Also underway is a separate double-blind, placebo-controlled study of the oral immunotherapy protocol, he added.

The study is still in its early stages, but data are available on 18 children participating in it.

The children are one to 16 years old and have completed one year in the study. Among 12 assigned to active therapy, the mean tolerance at one year was 15 peanuts, compared with 1.5 peanuts for six placebo-group children (P<0.05),>

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