James Martin, MD, DSc
McGill University Health Centre and McGill University Health Centre Research Institute and McGill University, Montréal, QC

Irritant asthma is a clinically relevant entity that is recognized best in its acute form but may also complicate treatment of asthma when irritant exposure is not recognized. Irritant asthma is a neutrophilic phenotype and, as such, may not fall into the treatment paradigm of so-called T2 high asthma. Using a murine model of irritant asthma, it has been possible to explore the role of interleukin (IL)-33 in airway hyperresponsiveness and inflammation. Chlorine, a common cause of irritant asthma and a potent oxidant that likely shares many features with other oxidants, triggers IL-33 secretion. IL-33 expands innate lymphoid cells and the secretion of IL-13. This pathway is protective against airway dysfunction and inflammation in contrast to its pathogenic role in T2 high asthma. Novel biologics directed against the IL-33 pathway, although reducing exacerbations in T2 high asthma, may not be appropriate for T2 low irritant asthma.

Learning Objectives
At the end of this presentation, attendees will be able to:

  • Identify the potential importance of irritant exposure for the control of asthma;
  • Understand the endotypic characteristics of irritant asthma; and
  • Evaluate the characteristics of patients likely to benefit from some novel biologics directed against inleukin-33.

CanMEDS Roles Addressed: Health Advocate, Medical Expert, Scholar