Molecular Signatures of Aeroallergen Sensitization in Pediatric Populations: A Comparative Study Across Spanish Cities

Abstract

Spain exhibits significant climatic variability across its regions, ranging from the humid oceanic climate in the north to the Mediterranean and stepped climates in the southern and central areas. These climatic differences influence environmental allergen exposure, which may, in turn, affect allergic sensitization patterns in the pediatric population. Variations in temperature, humidity, and airborne allergen distribution, such as pollen, dust mites, animal epithelia, and mold, contribute to regional disparities in allergic responses among children. Understanding how climatic conditions shape allergen recognition patterns across different geographical areas is essential for improving allergy prevention and management strategies. This study aims to shed light on this issue by identifying sensitization patterns in a pediatric population of 236 patients (with 2 age groups analyzed: 6-10 and 11-15 years old) from different climatic regions of Spain. Skin tests with standard aeroallergens were performed, and specific IgE (sIgE) analysis by Allergy Explorer of Macroarray Diagnostic test (ALEX²) and Western blot. The results revealed different sensitization trends across patients from the eight cities analyzed (Barcelona, Granada, Lugo, Sagunto, Santiago de Compostela, Valencia, and Zaragoza).

Keywords: aerobiology; allergens; allergic asthma; allergic rhinitis; climate change; exposome.

Figure 1

Bubble plot illustrating the distribution of airborne allergens in each region. The size of the bubbles is directly proportional to the number of patients who are sensitized (sIgE ≥ 0.3 kU_A/L) to the allergen.

Figure 2

Mean levels of sIgE for each mite allergen among all patients from eight different populations in Spain (Barcelona, Granada, Lugo, Mostoles, Sagunto, Santiago, Valencia, and Zaragoza). Each pie chart represents the proportional distribution of sIgE reactivity to different allergens, as indicated by the color-coded legend. Allergen abbreviations correspond to Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) allergens, as well as other mite species (Blomia tropicalis, Glycyphagus domesticus, Lepidoglyphus destructor, and Tyrophagus putrescentiae).

Figure 3

Mean levels of sIgE illustrating sensitization to different pollen allergens in patients from eight populations in Spain (Barcelona, Granada, Lugo, Mostoles, Sagunto, Santiago, Valencia, and Zaragoza). Each pie chart represents the relative distribution of sIgE against various pollen allergens, according to the color-coded legend. Sensitizations include allergens from Betula (Bet v 1, Bet v 2, Bet v 6), Cupressus (Cup a 1), Platanus (Pla a 1, Pla a 2, Pla a 3), Olea (Ole e 1, Ole e 7, Ole e 9), Phleum (Phl p 1, Phl p 12, Phl p 2, Phl p 5, Phl p 6, Phl p 7), Lolium (Lol p 1), Salsola (Sal k 1), Parietaria (Par j 2), and Artemisia (Art v 1, Art v 3).

Figure 4

Sensitization profile to specific IgE (sIgE): (A) heatmap and (B) scatter plots with bars of the 20 most frequently identified molecular allergens in each region, along with their serodominance. (C) IgE-Western blot of the different groups included against the three most prevalent allergen sources in each region. Different patterns of sIgE binding were identified for each group of patients.

Figure 5

Köppen–Geiger climate map of research centers. Modified figure of climate classification map according to Köppen from the National Atlas of Spain (ANE) [24].