Objective: The potential benefit of a combined adenotonsillectomy and bronchoscopy with bronchoalveolar lavage (TA-B-BAL) in preschool children with asthma has been debated in the literature. We aimed to describe the clinical course of preschool children with severe asthma undergoing this combined procedure. Study Design: This is a retrospective case-control study. Patient Selection: Preschool patients diagnosed with severe asthma who underwent TA-B-BAL treatment between 2012 and 2019 were included as cases. Controls were age and sex matched patients receiving standard asthma care. Methodology: A retrospective patient chart review was conducted. Data on demographics, clinical characteristics, medication use, virology and microbiology from bronchoalveolar lavage, and asthma control questionnaires were collected. Cases and controls were compared with t-tests and regression analysis. Results: Eighteen preschool subjects (mean age 3.19±1.13 years) in the case group were matched to eighteen control subjects receiving standard care. A Poisson mixed effects regression analysis revealed reduced risk of oral corticosteroid use (RR 0.39, 95%CI 0.18, 0.83, p=0.014), reduced emergency department visits (RR 0.36, 95%CI 0.17, 0.75, p=0.01) and reduced risk of asthma exacerbations (RR 0.58, 95%CI 0.28, 1.20, p=0.14) in cases compared to controls. Ten patients experienced clinically meaningful improvements in TRACK scores after the procedure (p<0.001). Conclusion: This pilot study provides early evidence that preschool children with severe asthma may benefit from combined adenotonsillectomy and bronchoscopy with bronchoalveolar lavage procedure. The procedure is a useful adjunct for reduction of medication use and hospital visits for preschool age patients with severe asthma.

Background: Multiplex tests allow for measurement of allergen-specific IgE responses to multiple allergen extracts and components 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 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, ALEX (Macro Array Dx), MeDALL-chip (Mechanisms of Development of Allergy) (Thermo Fisher), and EUROLINE (EUROIMMUN). Skin prick test (n=51) and ImmunoCAP (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 component-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, Cor a 9. Conclusion: Our models support the notion that conversion is reasonably possible between sIgE multiplex platforms for allergen extracts and components and may provide options to aggregate data for future meta-analysis.