Impact of age, sex, and urban environment on allergen-specific IgE profiles to grass pollen components: a cross-sectional study in Northern Italy.

Background: Asthma and rhino-conjunctivitis are frequently triggered by sensitization to airborne allergens, particularly grass pollens. This study aimed to assess whether age, sex, and living environment influence allergen-specific IgE responses to grass pollen components, using a molecular diagnostic approach.

Methods: A total of 772 patients referred to the Allergology outpatient clinic for suspected grass pollen allergy were enrolled. Allergen-specific IgE levels were measured using the ImmunoCAP ISAC microarray. Patients were stratified into nine groups based on age, sex, and city of residence (Milan, Pavia, and surrounding rural/suburban areas). Sensitization to nine grass pollen components (Cyn d 1, Phl p 1, Phl p 2, Phl p 4, Phl p 5, Phl p 6, Phl p 7, Phl p 11, and Phl p 12) was analyzed.

Results: Sensitization patterns varied by sex, age group, and place of residence. Male patients showed higher IgE positivity for Phl p 2 and Phl p 6. Overall, the highest sensitization rates were observed in adolescents and in patients living in Milan. Cyn d 1, Phl p 1, Phl p 4, and Phl p 5 showed widespread sensitization across all groups, though rates were higher in males and in urban areas.

Conclusions: This cross-sectional study highlights that demographic and environmental factors - particularly sex, age, and urban living - can influence IgE sensitization to grass pollen components. These findings emphasize the relevance of molecular diagnostics in understanding allergy epidemiology and support the hypothesis that environmental exposure, including air pollution, may affect sensitization profiles.