Antibody profiles and self‐reported symptoms to pollen‐related food allergens in grass pollen‐allergic patients from northern Europe

Background: Most studies on pollen‐related food allergy have so far focused on the association of birch/weed pollen allergens and plant food allergy. The aim of this study was to elucidate the allergen spectrum among a group of grass pollen‐allergic patients from northern Europe and to relate the results to clinical histories of pollen‐related food allergy. Methods: Fifty‐eight grass pollen‐allergic patients answered a questionnaire regarding allergy to foods. Blood samples were taken to test IgE‐reactivity to a large panel of pollen allergens and pollen‐ and nonpollen‐related food allergens using crude allergen extracts and recombinant and native allergens. Results: Three different groups of grass pollen‐allergic patients were identified according to their IgE antibody profile: a grass pollen group only (19%), a grass and tree pollen group (29%) and a grass, tree and compositae (pan‐) pollen group (48%). No sensitization to Bet v 1 as well as almost no IgE to plant food was observed in the grass pollen group. In contrast, nearly all patients in the two tree‐related groups had IgE to Bet v 1, which reflected the high frequency of adverse reactions to typical birch‐related food in these groups. Only four patients belonging to the pan‐pollen group displayed IgE to profilin Phl p 12/Bet v 2. Patients in the pan‐pollen group reported significantly more symptoms to food allergens compared with patients in the two other groups. The most frequently reported symptom was the oral allergy syndrome. Conclusions: Sensitization to grass pollen alone is rare among grass pollen‐allergic patients from northern Europe. The majority of patients are in addition sensitized to birch (Bet v 1), which seems to be closely related to their pollen‐derived food allergy. The study highlights the advantage of using well‐defined allergen molecules for the diagnosis of cross‐reactivity between pollen and food allergens.