The impact of age on serum allergen-specific IgE to inhaled molecular components

Background Respiratory allergy is characterised by an IgE-mediated reaction. The immune system functions, including IgE production, progressively decline over time, such as growing up and ageing. Molecular-based allergy diagnostic defines sensitisation profile. This study aimed to evaluate the impact of age on serum allergen-specific IgE to molecular component levels in a large sample of subjects. Methods Serum IgE to: Phl p1, Bet v1, Ole e1, Cup a1, Par j2, Can f1, Der p2, and Fel d1 were assessed by ISAC method. Sera from 2788 patients, 1230 males (44.1%) and 1558 females (55.9%), median age 23 years (1st and 3rd quartiles: 9.7–49.7 years; age range: 1 month–103 years) were analysed. Results The number of positive tests (i.e. sensitisation) tended to increase between birth and school-age till young adulthood and then decreased (p < 0.0001) with the exception of Fel d 1 (p = 0.14). A similar age-dependent trend was observed considering the levels of each allergen components: the levels of each allergen component, with the exception of Fel d 1, tended to increase till early adulthood and then to decrease reaching the lowest levels in the elderly. Conclusions Allergen-specific IgE production to inhaled molecular components trend to reduce with ageing, but with differences between allergens. This phenomenon should be adequately evaluated managing allergic patients.