D3.41 - Population-based IgE profiling of adolescents using a multiplex allergen array

Type I allergic reactions are defined by the production of allergen-specific IgE antibodies. This study used molecule-resolved IgE diagnostics to evaluate sensitization patterns in an Austrian adolescent population.

Serum samples from 291 unselected pupils aged 14-19 years (173 female, 118 male) in the county of Salzburg, Austria, were analyzed using the ALEX³ allergen array to determine IgE responses to 218 allergen molecules and 72 extracts (cutoff ≥ 0.3 kUA/L). IgE sensitization patterns were evaluated and related to allergic reactions reported in a detailed questionnaire on allergic symptoms. 

Within the cohort, 61.8% of females and 68.6% of males demonstrated IgE reactivity to at least one of the tested allergens. Most participants exhibited multi-sensitization, with an average of nine allergen reactivities per individual. Sensitization to pollen was highly prevalent, predominantly driven by the grass pollen allergens Phl p 1 (22.3%), Phl p 5 (17.9%) and the PR-10 birch pollen allergen Bet v 1 (15.1%) along with its associated food allergens, e. g. Cor a 1 (16.2%).  Among weed pollen, Pla l 1 was the most relevant allergen (6.2 %). Other frequently detected allergens included the insect venom allergens Api m 1 (18.6 %) and Ves v 5 (10.3%); mite group 1 (13.4%), group 2 (17.5%), group 23 allergens (12.7%) and Fel d 1 from cat (15.1%).  

Allergic symptoms were reported by 38.4% of participants (self-report or clinical diagnosis) reflecting a heterogeneous clinical expression. Despite comparable sensitization rates to grass pollen and insect venom allergens, clinical manifestation was substantially higher for Phl p 1 (90.6%) compared to Api m 1 (29.6%) in sensitized individuals.  

Allergen sensitization is common in adolescents and characterized by broad IgE reactivity, predominantly toward pollen allergens. Compared with a similar cohort ten years earlier, the overall sensitization frequency increased from 53.5% to 64.6%, while sensitization to marker allergens has remained coherent. This cohort provides the basis for the classification of allergic and sensitized individuals for identification of novel antibody biomarkers to distinguish clinical allergies from asymptomatic sensitizations.