A molecular sensitization map of European children reveals exposome- and climate-dependent sensitization profiles

Understanding differences in sensitization profiles at the molecular allergen level is important for diagnosis, personalized treatment and prevention strategies in allergy.

Immunoglobulin E (IgE) sensitization profiles were determined in more than 2800 sera from children in nine population-based cohorts in different geographical regions of Europe; north [BAMSE (Sweden), ECA (Norway)], west/central [PIAMA (the Netherlands), BiB (the United Kingdom), GINIplus (Germany)], and south [INMA Sabadell and Gipuzkoa (Spain) and ROBBIC Rome and Bologna (Italy)] using the MeDALL-allergen chip.

Sensitization to grass pollen allergen, Phl p 1, and to major cat allergen, Fel d 1, dominated in most European regions whereas sensitization to house dust mite allergens Der p 1, 2 and 23 varied considerably between regions and were lowest in the north. Less than half of children from Sabadell which has a hot and dry climate were sensitized to respiratory allergens, in particular house dust mite allergens as compared to Gipuzkoa nearby with a more humid climate. Peanut allergen Ara h 1 was the most frequently recognized class 1 food allergen in Northern/Western Europe, while the fruit allergens Pru p 3, Act d 1 and 2 were prominent in Southern and Western/Central Europe. Ves v 5-sensitization dominated in North and West/Central Europe.

We show regional, exposome- and climate-dependent differences in molecular IgE-reactivity profiles in Northern, Western/Central and Southern Europe which may form a molecular basis for precision medicine-based approaches for treatment and prevention of allergy.