Bronchial Thermoplasty Induced Changes in Blood Transcriptome Profile of Patients with Severe Asthma

Bronchial thermoplasty (BT) is a non-pharmacological treatment for severe asthma. The working mechanism and response determinants of BT remain partly unknown. This study aims to investigate whether a systemic transcriptomic response to BT can be detected and contextualized against a control cohort. Whole blood was collected at baseline and six months after BT from severe asthma patients (n = 31) and a control cohort (n = 126). RNA was isolated and sequenced. The following comparisons were made: before and after BT, responders and non-responders, and severe asthma (at baseline) versus controls. Differentially expressed genes were identified across 179 samples using DESeq2. Pathway enrichment was investigated using gene set enrichment and overrepresentation analyses. Following BT, pathways related to nervous system development, ion channel activity, muscle tissue development, and cilia function were downregulated. In responders specifically, gene sets involved in nervous system and muscle development were downregulated. Compared with the control cohort, pathways related to nervous system development and ion channel activity were upregulated in the severe asthma cohort at baseline. In conclusion, systemic blood-derived transcriptomic changes can be detected in severe asthma patients six months after BT and may provide insight into BT mechanisms and its responder profile.