Tara N. Havens

and 11 more

Background: Viral wheeze is an important risk factor for asthma, which comprises several respiratory phenotypes. We sought to understand if the etiology of early life wheezing illnesses relates to childhood respiratory and asthma phenotypes. Methods: Data were collected prospectively on 429 children in the Urban Environment and Childhood Asthma (URECA) birth cohort study through age 10 years. We identified wheezing illnesses and the corresponding viral etiology (PCR testing of nasal mucus) during the first three years of life. Six phenotypes of respiratory health were identified at 10 years of age based on trajectories of wheezing, allergic sensitization, and lung function. We compared etiology of early wheezing illnesses on these respiratory phenotypes and the development of asthma. Results: In the first three years of life, at least one virus was detected in 324 (67%) of the 483 wheezing episodes documented in the study cohort. Using hierarchical partitioning we found that non-viral wheezing episodes accounted for the greatest variance on asthma diagnosed at both 7 and 10 years of age (8.0% and 5.8% respectively). Rhinovirus wheezing illnesses explained the most variance on respiratory phenotype outcome followed by non-viral wheezing episodes (4.9% and 3.9% respectively) at 10 years of age. Conclusion and Relevance: Within this high-risk urban-residing cohort early life, non-viral wheezing episodes were frequently identified and associated with asthma development. Though rhinovirus wheezing illnesses had the greatest association with phenotype outcome, the specific etiology of wheezing episode in early life provided limited information about subsequent wheezing phenotypes.
BACKGROUND: Characterization of allergic responses to cockroach (CR), a common aeroallergen associated with asthma, has focused mainly on IgE reactivity, but little is known about T cell responses, particularly in children. We conducted a functional evaluation of CR allergen-specific T cell reactivity in a cohort of CR allergic children with asthma. METHODS: Peripheral blood mononuclear cells (PBMCs) were obtained from 71 children, with mild-to-moderate asthma who were enrolled in a CR immunotherapy (IT) clinical trial, prior to treatment initiation. PBMC were stimulated with peptide pools derived from 11 CR allergens, and CD4+ T cell responses assessed by intracellular cytokine staining. RESULTS: Highly heterogeneous responses in T cell reactivity were observed among participants, both in terms of the magnitude of cytokine response and allergen immunodominance. Reactivity against Bla g 9 and Bla g 5 was most frequent. The phenotype of the T cell response was dominated by IL-4 production and a Th2 polarized profile in 54.9% of participants, but IFN production and Th1 polarization was observed in 25.3% of the participants. The numbers of regulatory CD4+ T cells were also highly variable and the magnitude of effector responses and Th2 polarization were positively correlated with serum IgE levels specific to a clinical CR extract. CONCLUSIONS: Our results demonstrate that in children with mild-to-moderate asthma, CR-specific T cell responses display a wide range of magnitude, allergen dominance, and polarization. These results will enable examination of whether any of the variables measured are affected by IT and/or are predictive of clinical outcomes.