Physician-authored summaries and commentary on the most important medical research, provided by the NEJM Group, a division of the Massachusetts Medical Society.
© Massachusetts Medical SocietySeptember 2022
About 20% of patients with bronchiectasis have eosinophilic inflammation.
Similar to chronic obstructive pulmonary disease (COPD) and asthma, bronchiectasis can display different disease characteristics, or phenotypes. Although bronchiectasis classically is thought to be a neutrophilic disease, some patients with bronchiectasis have eosinophilic inflammation.
Researchers used multiple European datasets to characterise patients with eosinophilic bronchiectasis. As in asthma and COPD, peripheral blood eosinophils were found to be a surrogate marker for sputum eosinophils, and 23% of bronchiectasis patients had blood eosinophil counts above 0.3 x 109 cells/L. Eosinophil counts below 0.1 x 109 cells/L were associated with greater disease severity and mortality, but higher eosinophilic counts were associated with shorter time to exacerbations, especially in bronchiectasis patients with concomitant Pseudomonas aeruginosa infections.
Comment: Among patients with asthma or COPD, those with eosinophilic inflammation respond better to inhaled corticosteroids (ICS) than do those with neutrophilic or paucigranular inflammation. COPD patients with blood eosinophil counts above 0.3 x 109 cells/L have fewer exacerbations with ICS, but those with counts below 0.1 x 109 cells/L have minimal response when ICS is added to dual long-acting bronchodilator therapy. Are those observations relevant to bronchiectasis patients? Although current guidelines do not recommend routine use of ICS for bronchiectasis unless patients have concomitant asthma or COPD (Eur Respir J 2017; 50: 1700629), some evidence shows that ICS improve quality of life for patients with eosinophilic bronchiectasis. In an accompanying editorial, the authors call for further study on the complex relation between inflammation and the lung microbiome in bronchiectasis.
DAVID J. AMROL, MD
Associate Professor of Clinical Internal Medicine, Director of the Division of Allergy and Immunology, University of South Carolina School of Medicine, Columbia, USA.
Shoemark A, et al. Characterization of eosinophilic bronchiectasis: a European multicohort study. Am J Respir Crit Care Med 2022; 205: 894-902.
Singh D, Brightling C. Bronchiectasis, the latest eosinophilic airway disease: what about the microbiome? Am J Respir Crit Care Med 2022; 205: 860-862.
This summary is taken from the following Journal Watch title: General Medicine.