We sought to describe the clinical and immunologic characteristics of patients with peanut allergy from 3 countries (Spain, the United States, and Sweden) using a molecular component diagnostic approach.
Patients with peanut allergy from Madrid (Spain, n = 50), New York (United States, n = 30), Gothenburg, and Stockholm (both Sweden, n = 35) were enrolled. Clinical data were obtained either from a specific questionnaire or gathered from chart reviews. IgE antibodies to peanut extract and the peanut allergens rAra h 1, 2, 3, 8 and 9, as well as to cross-reactive birch (rBet v 1) and grass (rPhl p 1, 5, 7, and 12) pollen allergens, were analyzed.
American patients frequently had IgE antibodies to rAra h 1 to 3 (56.7 % to 90.0 % ) and often presented with severe symptoms. Spanish patients recognized these 3 recombinant peanut allergens less frequently (16.0 % to 42.0 % ), were more often sensitized to the lipid transfer protein rAra h 9 (60.0 % ), and typically had peanut allergy after becoming allergic to other plant-derived foods. Swedish patients detected rAra h 1 to 3 more frequently than Spanish patients (37.1 % to 74.3 % ) and had the highest sensitization rate to the Bet v 1 homologue rAra h 8 (65.7 % ), as well as to rBet v 1 (82.9 % ). Spanish and Swedish patients became allergic to peanut at 2 years or later, whereas the American children became allergic around 1 year of age.
Peanut allergy has different clinical and immunologic patterns in different areas of the world. Allergen component diagnostics might help us to better understand this complex entity.