IgE recognition patterns in peanut allergy are age dependent: perspectives of the EuroPrevall study

BACKGROUND: We tested the hypothesis that specific molecular sensitization patterns correlate with the clinical data/manifestation in a European peanut allergic population characterized under a common protocol. METHODS: 68 peanut allergic subjects and 82 tolerant controls from 11 European countries were included. Allergy to peanut and lowest symptom-eliciting-dose were established by double-blind placebo-controlled food-challenge in all but anaphylactic subjects. Information of early or late (before or after 14 years of age) onset of peanut allergy was obtained from standardized questionnaires. IgE to peanut allergens rAra h 1-3, 6, 8-9, profilin and CCD were determined using ImmunoCAP. RESULTS: 78% of peanut allergics were sensitised to peanut extract and 90% to at least one peanut component. rAra h 2 was the sole major allergen for the peanut allergic population. Geographic differences were observed for rAra h 8 and rAra h 9, which were major allergens for central/western and southern Europeans, respectively. Sensitisation to rAra h 1 and 2 were exclusively observed in early onset peanut allergy. Peanut tolerant subjects were frequently sensitised to rAra h 8 or 9 but not to storage proteins. Sensitisation to Ara h 2 ≥1.0 kUA /L conferred a 97% probability for a systemic reaction (p=0.0002). Logistic regression revealed a significant influence of peanut extract sensitization and region on the occurrence of systemic reactions (p=0.0185 and p=0.0436 respectively). CONCLUSION: Sensitization to Ara h 1, 2 and 3 is usually acquired in childhood. IgE to Ara h 2 ≥1.0 kUA /L is significantly associated with the development of systemic reactions to peanut. This article is protected by copyright. All rights reserved.