Single-cell analysis reveals epithelial alarmin-associated immune architecture in pediatric refractory and rhinovirus-positive asthma

Methods

Children with asthma were classified into refractory asthma (defined according to Global Initiative for Asthma criteria) and rhinovirus-positive asthma (defined by qPCR-confirmed rhinovirus infection). Bronchoalveolar lavage fluid samples from children with refractory asthma (n = 5), rhinovirus-positive asthma (n = 4) and healthy controls (n = 6) were subjected to single-cell RNA sequencing, followed by integrative bioinformatic analysis and cross-age comparison with adult asthma datasets.

Controls were obtained from individuals undergoing bronchoscopy for non-inflammatory indications and lacked a history of atopy or airway inflammatory disease. Results: Pediatric refractory asthma showed increased epithelial cell representation, elevated epithelial alarmin–related gene expression, enhanced chemokine and interferon-stimulated gene signatures, and increased expression of remodeling-associated genes. Cell–cell communication analysis identified enhanced macrophage-to-epithelium signaling mediated through FN1–CD44/αVβ integrin interactions.

Rhinovirus-positive asthma exhibited a more pronounced inflammatory profile, characterized by increased T-cell abundance, enhanced chemokine and interferon responses, and strengthened CTL–macrophage communication via the CCL5–CCR1 axis. Cross-age comparison indicated relatively higher epithelial alarmin–associated features in pediatric asthma and stronger chemokine-associated signatures in adult asthma.