The prevalence of mucus plugging in severe eosinophilic asthma and its relationship to clinical efficacy of anti-IL-5R treatment.

Mucus plugging (MP) of the airways is well recognized in the pathogenesis of acute severe and fatal asthma exacerbations.1 Patients with MP are more likely to have severe asthma and require higher inhaled corticosteroid and maintenance oral corticosteroid (mOCS) use.2 Subsegmental MP can be readily detectable by computed tomography (CT) imaging and is associated with airflow obstruction and gas trapping. The plugs themselves are typically eosinophil-rich, and the degree of MP has been shown to relate to the degree of sputum eosinophilia.