Type I allergic reactions to plant-derived food: A consequence of primary sensitization to pollen allergens

Abstract

Patients with pollen allergy also frequently experience allergic symptoms on ingestion of plantderived foods (fruits, vegetables, and spices). 1-3 The association of certain pollen allergies with food intolerance has led to the definition of clinical syndromes such as the celery-mugwort-birch pollen syndrome, the apple-birch pollen syndrome, and similar phenomena. More than 10 years ago, it was suggested that IgE antibodies that cross-react with pollen and food proteins could be responsible for the observed clinical phenomena. 4-8 New information allows us to attribute pollen-food allergy syndromes to the cross-reactivity of IgE antibodies to conserved plant allergens that are expressed in related and unrelated plant species and different plant tissues. The term conserved protein refers to proteins that fulfill important biologic functions and therefore are conserved in their sequence and/or structure. Prominent conserved allergens responsible for pollen-food cross-reactivities are the actin-binding protein profilin, first described in birch pollen (Bet v 2), 91~ and the major birch pollen allergen, Bet v 1,11 which is highly homologous to pathogenesis-related plant proteins. We have developed the hypothesis that sensitization to airborne pollen allergens represents the primary event leading to the induction of IgE antibodies that are then capable of cross-reacting with homologous food allergens. This study summarizes evidence for this hypothesis. Complementary DNAs coding for a number of