Allergic cross-reactivity among peanut and tree nut allergens

Authors: Maleki, Soheila; Hurlburt, Barry

Submitted to: United States-Japan Cooperative Program in Natural Resources (UJNR)
Publication Type: Proceedings
Publication Acceptance Date: 11/20/2018
Publication Date: 12/4/2018
Citation: Maleki, S.J., Hurlburt, B.K. 2018. Allergic cross-reactivity among peanut and tree nut allergens. United States-Japan Cooperative Program in Natural Resources (UJNR). 44:3-5.

Interpretive Summary: People with peanut allergy are also often allergic to tree nuts, and vice versa, as well as to other foods and must avoid all of them. These include nuts and seeds that often do not belong to the same botanical families, but may cause cross-reaction because they contain proteins that are homologous to the major allergens (i.e., those belonging to the same protein family, or Pfam) and are difficult to distinguish from each other. Significant amount of information has emerged from the microarray analysis described here. Using microarray analysis, we identified a group of allergen peptides that were recognized by patients with cross reactivity to both walnuts and peanuts, and another group that were recognized by all of the sera from nut allergic patients. The cross-reactive proteins were identified by digestion and mass spectrometry, to be major allergens in nuts. Therefore, a group of conserved, similar IgE binding regions, not necessarily within the same family of proteins, could account for the high degree of cross reactivity between peanuts and many different nuts and seeds. Our analysis with clinically well-characterized patient sera will allow the development of more reliable diagnostic assays and discovery of biomarkers related to allergic status.

Technical Abstract: People with peanut allergy are also often allergic to tree nuts, and vice versa, as well as to other foods and must avoid all of them. These include nuts and seeds that often do not belong to the same botanical families, but may cause cross-reaction because they contain proteins that are homologous to the major allergens (i.e., those belonging to the same protein family, or Pfam) and are difficult to distinguish from each other. Significant amount of information has emerged from the microarray analysis described here. Using SPOTs membranes and microarray analysis, we identified a group of peptides that were recognized by patients with cross reactivity to both walnuts and peanuts, and another group that were recognized by all of the sera from nut allergic patients. The cross-reactive proteins were identified by digestion and mass spectrometry, to be major allergens in nuts. Therefore, a group of conserved, similar IgE binding regions, not necessarily within the same family of proteins, could account for the high degree of cross reactivity between peanuts and many different nuts and seeds. Our analysis with clinically well-characterized patient sera will allow the development of more reliable diagnostic assays and discovery of biomarkers related to allergic status.