Blood eosinophilia and eosinophilic inflammation correlates strongly with AR
In order to identify the cellular drivers of airway inflammation in AR, we took a deeper look into the SSIC cohort. [10, 11] Using flow cytometry data from whole blood analysis, we performed unsupervised PhenoGraph clustering of whole blood subsets and correlated them with atopy status (Figure 1A-C and Supplementary Table 3 ). Of all cell subsets, eosinophils were identified as the only leukocyte cluster directly associated with atopy (Figure 1B and C ). Atopic individuals were demonstrated to have higher frequencies of eosinophils than individuals without atopy (Supplementary Figure 1A ). Following this, we did a correlation analysis of the symptoms of AR with eosinophil counts. While atopy status was defined objectively by SPT, assessment of AR manifestation and symptoms for SSIC cohort was based on a survey questionnaire. [11] Despite the subjective nature of these self-reported parameters, we observed strong associations between eosinophils and AR, where AR cases registered significantly higher eosinophil frequencies than non-AR controls (Figure 1D ). The same trend was observed for total IgE levels (Figure 1E ).