Key Factors in the Development of Asthma: Atopy

One approach to unraveling the role of the multiple risk factors that contribute to the development of asthma is to track the process in cohorts of children from birth until age(s) at which the disease manifests. In relation to atopy, this involves the prospective and cross-sectional study of allergen-specific T cell function in cohorts of children, focusing particularly on responses to the major inhalant allergens that have been identified as asthma triggers in later life. The key issues in this context are ( 1 ) what factor(s) are responsible for the polarization of allergen-specific helper T cell memory toward the atopyassociated helper T cell type 2 (Th2) cytokine phenotype, and ( 2 ) why does the development of this form of helper T cell memory lead to the development of asthma in some but not all individuals with atopic asthma.