IgE responses to multiple allergen components among school-aged children in a general population birth cohort in Tokyo

Background: Response patterns to allergen components among Japanese children have not been studied extensively. Objective: Our aim was to examine the differences in sensitization patterns at ages 5 years and 9 years to identify longitudinal changes in the degree and patterns of sensitization in a birth cohort of Japanese children. Methods: Our study enrolled 984 children at aged 5 years between 2008 and 2010, and 729 children aged 9 years between 2012 and 2014. Allergic diseases were assessed using the ISAAC and UK Working Party's Diagnostic Criteria. Serum-specific IgE titers to allergen components were measured by multiplex array ImmunoCAP ISAC when the children were aged 5 and 9 years. Principal component analysis (PCA) was performed to characterize IgE sensitization to allergen components. Results: The prevalence of allergic rhinitis increased considerably over time (10.6%–31.2%). Furthermore, the sensitization prevalence to allergen-specific IgE (sIgE) also increased from 57.8% at age 5 years to 74.8% at age 9 years. IgE sensitization prevalence to Der f 1 (mites) was 42.1% at age 5 years and 54.3% at age 9 years. Furthermore, children were highly sensitized to Cry j 1 (Japanese cedar) (32.8% at age 5 years and 57.8% at age 9 years). Principle component analysis showed that sensitization to PR-10 cross-reactive components was independent of sensitization to mite and that no children acquired sensitization to pollen before acquiring sensitization to mite. Conclusions: The prevalence of allergic rhinitis and related allergen components increased from age 5 years to age 9 years in Japanese children. Keywords: Allergy, Asthma, Atopic dermatitis, Child, Cohort, Eczema, IgE, ISAAC, ISAC, Prospective birth cohort, Rhinitis, Sensitization, Wheeze