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Background: The lung clearance index (LCI) is a measure of pulmonary function. Variable feasibility (50‐>80%) in preschool children has been reported. There are limited studies exploring its relationship to respiratory symptoms and how it predicts persistent wheeze. We aimed to assess the association with respiratory symptoms in preschool‐aged children with LCI and determine its utility in predicting persistent wheeze. Methods: LCI was measured in a subcohort of the CHILD Cohort Study at age 3 years using SF6 multiple breath washout test mass spectrometry. Respiratory symptom phenotypes at age 3 were derived from children's respiratory symptoms reported by their parents. Responses were used to categorize children into 4 symptom groups: recurrent wheeze (3RW), recurrent cough (3RC), infrequent symptoms (IS), and no current symptoms (NCS). At age 5 years, these children were seen by a specialist clinician and assessed for persistent wheeze (PW). Results: At age 3 years, 69% (234/340) had feasible LCI. Excluding two children with missing data, 232 participants were categorized as follows: 33 (14%) 3RW; 28 (12%) 3RC; 17 (7%) IS; and 154 (66%) NCS. LCI z‐score at age 3 years was highest in children with 3RW compared to 3RC (mean (SD): 1.14 (1.56) vs. 0.09 (0.95), p <.01), IS (mean (SD): −0.14 (0.59), p <.01), and NCS (mean (SD): −0.08 (1.06), p <.01). LCI z‐score at age 3 was predictive of persistent wheeze at age 5 (PW) (AUROC: 0.87). Conclusions: LCI at age 3 was strongly associated with recurrent wheeze at age 3, and predictive of its persistence to age 5. [ABSTRACT FROM AUTHOR]

Background: Multiplex tests allow for measurement of allergen‐specific IgE responses to multiple extracts and molecular allergens and have several advantages for large cohort studies. Due to significant methodological differences, test systems are difficult to integrate in meta‐analyses/systematic reviews since there is a lack of datasets with direct comparison. We aimed to create models for statistical integration of allergen‐specific IgE to peanut/tree nut allergens from three IgE test platforms. Methods: Plasma from Canadian and Austrian children/adolescents with peanut/tree nut sensitization and a cohort of sensitized, high‐risk, pre‐school asthmatics (total n = 166) were measured with three R&D multiplex IgE test platforms: Allergy Explorer version 1 (ALEX) (Macro Array Dx), MeDALL‐chip (Mechanisms of Development of Allergy) (Thermo Fisher), and EUROLINE (EUROIMMUN). Skin prick test (n = 51) and ImmunoCAP (Thermo Fisher) (n = 62) results for extracts were available in a subset. Regression models (Multivariate Adaptive Regression Splines, local polynomial regression) were applied if >30% of samples were positive to the allergen. Intra‐test correlations between PR‐10 and nsLTP allergens were assessed. Results: Using two regression methods, we demonstrated the ability to model allergen‐specific relationships with acceptable measures of fit (r2 = 94%‐56%) for peanut and tree nut sIgE testing at the extract and molecular‐level, in order from highest to lowest: Ara h 2, Ara h 6, Jug r 1, Ana o 3, Ara h 1, Jug r 2, and Cor a 9. Conclusion: Our models support the notion that quantitative conversion is possible between sIgE multiplex platforms for extracts and molecular allergens and may provide options to aggregate data for future meta‐analysis. [ABSTRACT FROM AUTHOR]

In contrast to other environmental allergens, the association with atopic dermatitis was present for Fel d 1, which may suggest that the skin is an important route of sensitization for this allergen. GLO:1X5/01dec19:all13927-fig-0002.jpg PHOTO (COLOR): Hierarchical clustering performed on patient sensitization profiles and allergen components indicating clusters by allergen source and biochemical family (sensitized: N = 37; nonsensitized: N = 18). In conclusion, we provide data describing a potentially high-risk preschool asthma cohort in Canada using a comprehensive approach capturing sensitization to allergens of paramount importance. By applying both allergen extracts and components, we identified that peanut and animal allergens from cat and dog were major allergen sources in this North American cohort of preschool asthmatics. [Extracted from the article]