Search

To cite this article: Melioli G, Marcomini L, Agazzi A, Bazurro G, Tosca M, Rossi GA, Minale P, Rossi R, Reggiardo G, Canonica GW, Passalacqua G. The IgE repertoire in children and adolescents resolved at component level: A cross-sectional study. Pediatr Allergy Immunol 2012: 23: 433–440. Abstract Background: It is well known that allergy evolves at clinical level from the birth to adulthood, and this has been clearly demonstrated also at a level of sensitization. However, little information is available on the evolution of the IgE repertoire directed to single allergenic components. In this cross-sectional, observational study, the evolution of the IgE repertoire was analysed at component level. Methods: Serum samples from 901 allergic patients, stratified in 6 groups according to age, were analysed by ImmunoCAP ISAC, a microarray chip that allows to identify the presence of specific IgE towards 103 different allergen components. Total IgE were also evaluated. Results: The behaviour of total IgE according to age strictly paralleled that of the sum of specific IgE directed to molecular components. As expected, food-related components (in particular those of milk and egg) were the most frequently recognized in the earliest ages, whereas specific IgE to plant allergens appeared invariably later. Nonetheless, IgE specific to mite components was the most represented in all age classes. Of note, specific IgE against cross-reacting allergens was virtually absent in the first years and tended to appear only after the age of 6. Conclusion: Despite this was not a study performed on a cohort of patients followed up from birth to adolescence, the molecular patterns of allergen recognition resulted modified according to age. These findings may support, at molecular level, the clinical features of the allergic march.

Background Allergic sensitization and diseases have been reported to have a very high and increasing prevalence in elite athletes. Over 80% of allergic athletes are poly-sensitized. Objective This study aims at evaluating the potential diagnostic added value of a microarray technology (ImmunoCAP ISAC, Phadia AB [at present Thermo Fisher Scientific] Uppsala, Sweden which detects IgE antibodies to specific or cross-reacting allergen components. Methods Seventy-two poly-sensitized athletes according to skin prick test (SPT) with different allergic phenotypes (asthma n = 19; rhino-conjunctivitis n = 20; food allergy and/or oral allergy syndrome n = 13; no clinical symptoms n = 20) and two different control populations (20 poly-sensitized sedentary subjects with respiratory allergy and 20 healthy athletes with negative SPT) were studied for detecting specific IgE (sIgE) both to allergen extracts (ImmunoCAPsIgE) and to allergen components (ImmunoCAP ISAC). Results ImmunoCAP ISAC detected the presence of sIgE in 90% of poly-sensitized athletes – in 96% with symptoms and in 75% without symptoms – and in 100% of allergic controls. The pattern of positivity towards the 103 components tested differed from subject to subject, even in those with the same sensitization to allergen extract SPT or sIgE. Based on the ISAC results, poly-sensitized athletes were classified into the following prototypical patterns, differently represented in the clinical phenotypes studied (P = 0.03): (1) One single predominant specific allergen positivity; (2) sIgE to two or more non-cross-reacting allergens; (3) sIgE to cross-reacting allergens; and (4) sIgE to components potentially responsible for severe allergic reactions. Conclusions The ImmunoCAP ISAC represents a useful additional tool for diagnosis and management of poly-sensitized athletes.

Background The allergic march is well known at the level of pattern of sensitisation, but there is no information of its evolution in term of sensitzation to single allergenic molecules. We investigated the evolution of the IgE repertoire by means of a microarray allergen assay. Methods Serum samples from allergic patients of a wide age range were analyzed by a micorarray chip, which allow to identify in a single assay the presence of specific IgE towards 103 allergenic molecules. Total IgE were also evaluated as an internal control. Patients were stratified in 6 groups according to their age (0–2; 3–5; 6–9; 10–13; 14–17 and >17 years). Results Samples from 609 patients were analysed. The behaviour of total IgE according to age strictly paralleled that of the sum of specific IgE. Food-related components were the more frequently recognized in the first ages, whereas specific IgE to plant allergens appeared later. Nonetheless, mite-specific IgE were the most represented in all age classes. Specific IgE against cross-reacting allergens were virtually absent in the first years and tended to appear after the age of 6. Conclusions The molecular pattern of allergen recognition according to age well reflects the clinical characteristics of the allergic march.