Airway Inflammation Before and After Bronchial Thermoplasty in Severe Asthma

Wijsman PC, Goorsenberg AWM, Ravi A, d'Hooghe JNS, Dierdorp BS, Dekker T, van Schaik CCLM, Ten Hacken NHT, Shah PL, Weersink EJM, Bel EH, Annema JT, Lutter R, Bonta PI.

J Asthma Allergy. 2022 Dec 16;15:1783-1794. doi: 10.2147/JAA.S383418. PMID: 36560975; PMCID: PMC9767029.

What is the key question?

  • Bronchial thermoplasty (BT) has been shown to provide improvements in exacerbation rates, hospital presentations and quality of life for patients with severe asthma, but its mechanism of action is unclear.
  • This study aimed to assess the effect BT had on airway inflammation and correlations with treatment responders. It included 28 patients with severe asthma and compared bronchoscopic samples at time of BT and 6 months after.

What is the bottom line?

  • BT-treated areas were found to have reduced inflammation-related gene expressions in the airway epithelium after 6 months compared to non-treated areas.
  • BT-responders did not show major changes in epithelium gene expressions, but did have signals in glycolysis (reduced) and corticosteroid-response (increased) genes compared to non-responders.
  • BT-responders were found to have higher pre-treatment lavage and blood eosinophil counts, and higher IgE counts.

Why read on?

  • The authors detail gene analysis that was performed on bronchoscopic epithelial samples and the inflammation-related genetic changes, particularly those in tumor necrosis (TNF)-alpha signalling. These data suggest that BT treatment effects go beyond the airway smooth muscle.