Transcriptomic profiling of the airway epithelium in COPD links airway eosinophilia to type 2 inflammation and corticosteroid response.

Background: A subset of COPD patients have high levels of eosinophils in the distal airways ("airway eosinophilia").

Objectives: To compare the gene expression of type 2 inflammation in airway epithelial brushings of COPD patients with and without airway eosinophilia and to investigate the changes after inhaled corticosteroids (ICS).

Methods: Post-hoc analyses of the DISARM randomised controlled trial investigated the expression of airway inflammation (type 1, 2, and 17), IL-13, and mast cell gene signatures at baseline and after 12-week ICS treatment.

Single-cell RNA sequencing of bronchoscopy specimens: development of a rapid minimal handling protocol.

Single-cell RNA sequencing (scRNA-seq) is an important tool for understanding disease pathophysiology, including airway diseases. Currently, the majority of scRNA-seq studies in airway diseases have used invasive methods (airway biopsy, surgical resection), which carry inherent risks and thus present a major limitation to scRNA-seq investigation of airway pathobiology. Bronchial brushing, where the airway mucosa is sampled using a cytological brush, is a viable, less invasive method of obtaining airway cells for scRNA-seq.