IGE BINDING TO A NEW CROSS-REACTIVE STRUCTURE - A 35 KDA PROTEIN IN BIRCH POLLEN, EXOTIC FRUIT AND OTHER PLANT FOODS

Food allergies in birch pollen allergic patients have been shown to be due to cross-reactivities of specific IEE antibodies which are direct ed against birch pollen allergens with related proteins in fruit, nuts and vegetables. We identified a new cross-reactive structure of 35 kD a in birch pollen and some plant food extracts by Enzyme Allergosorben t Test (EAST) and immunoblot inhibition studies. The 35 kDa birch poll en protein is a minor allergen to which approximately 10-15% of birch pollen allergic individuals have specific IgE. Our data demonstrate th at there is cross-reactivity of this protein with proteins of comparab le size from lychee, mango, banana, orange, apple, pear and carrot. Wh ile the 35 kDa protein is immunologically independent of the major bir ch pollen allergen Bet v 1, we also observed IgE binding to a 34 kDa s tructure which appears to be a Bet v 1 dimer.