New Approach to Peanut Allergy

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Summary and Comment

New Approach to Peanut Allergy

A monoclonal antibody against IgE might prevent severe allergic reactions in peanut-sensitive patients.

Antigen-specific IgE presumably mediates allergic reactions to peanuts. In this industry-supported, randomized, double-blind trial, researchers sought to determine the effect of a monoclonal antibody directed against IgE in 82 patients (mean age, 32) with histories of immediate hypersensitivity to peanuts. The anti-IgE antibody prevents binding of IgE to mast cells and basophils.

For each patient, the researchers first determined the threshold amount of ingested peanut flour that would trigger an allergic response; the mean threshold was 331 mg. Then, the patients were assigned to receive 4 monthly subcutaneous injections of placebo or 1 of 3 doses of anti-IgE. Several weeks after the final injection, each patient underwent another peanut challenge: The mean amount of ingested peanut flour required to elicit symptoms increased by 710 mg in placebo recipients and by 913 mg, 1650 mg, and 2627 mg, respectively, in the groups that received the 3 escalating doses of anti-IgE. This trend -- an increasing threshold of sensitivity with increasing doses of anti-IgE -- was statistically significant. No serious side effects were reported.

Comment: Despite the best efforts of peanut-allergic patients, they still inadvertently ingest foods containing peanut products and occasionally experience life-threatening reactions. The approach outlined in this study holds promise for ameliorating this concern, but the authors note that additional trials are necessary before anti-IgE is approved for general use.

— Allan S. Brett, MD

Published in Journal Watch General Medicine April 1, 2003