PEANUT AND OTHER FOOD ALLERGIES

Authors: Maleki, Soheila; Champagne, Elaine

Submitted to: United States Japan Natural Resources Protein Panel
Publication Type: Proceedings
Publication Acceptance Date: 10/1/2000
Publication Date: 11/25/2000
Citation: Maleki, S.J., Champagne, E.T. 2000. PEANUT AND OTHER FOOD ALLERGIES. United States Japan Natural Resources Protein Panel. QQ.

Interpretive Summary: Peanut, egg and milk are responsible for 80% of food allergies that occur in children. The only current method for prevention of food allergy is avoidance. Children become tolerant to most food allergies with age (e.g., eggs, milk, shellfish, soy, etc.); however, peanut allergy is rarely outgrown. Thus, it is increasingly difficult for an allergic individual to avoid an abundantly utilized and most often disguised food source such as peanuts, leading to accidental ingestion, anaphylaxis, and possibly death. In the U.S., and many other countries, peanuts are rarely ingested in raw form, and yet most investigations are carried out using raw peanuts. Our findings clearly demonstrate that thermal processing events, such as roasting, modify the biophysical and immunological behavior of the peanut proteins. Alterations in these properties cause an overall change in the allergenic properties of peanuts. One of the significant conclusions of this study is that peanut and other food allergens should be studied in the form they are ingested. The beneficiaries of this research will eventually be the individuals allergic to peanuts.

Technical Abstract: In the past decade, there has been an increase in allergic reactions to peanut and other food proteins, often resulting in fatal reactions. The development of improved methods for both diagnosis and treatment of all allergies requires a better understanding of the allergenic proteins and the immune responses that they induced. Various minor allergens and two major allergens have been identified in peanuts. Purified major allergens, Ara h 1 and Ara h 2, were shown to be recognized by the immunoglobulin E (IgE) of pooled serum from peanut allergic individuals. Also, T-cells from allergic individuals were specifically stimulated in response to the purified allergens. Prick skin tests were used for an in vivo analysis to confirm the allergenicity of these purified proteins and their utility in diagnosis of peanut allergies. Purification of the allergens allowed an in-depth analysis of the protein structure and the relationship of the structure to their function as allergens. Our most recent data indicates that thermal processing affects the structural characteristics of the major peanut allergens, which in turn contribute to an increase in the allergenic properties of these proteins. We are currently in the process of identifying the specific structural modifications caused by processing that may be responsible for increasing the allergic properties of the peanut proteins. Our studies are directly applicable to other foods and will contribute to a better understanding of food allergies in general.