Nature of airway inflammation and remodeling in chronic cough

J Allergy Clin Immunol. 2005 Sep;116(3):565-70. doi: 10.1016/j.jaci.2005.07.010.


Background: Chronic cough may be a result of asthma and non-asthma causes, but it is unclear whether there are specific inflammatory or remodeling changes.

Objective: We determined airway mucosal changes in patients presenting with asthmatic cough and cough associated with non-asthmatic causes.

Methods: Patients with chronic cough of non-asthmatic (n=33; postnasal drip/rhinitis in 6, gastroesophageal reflux in 5, bronchiectasis in 3, and idiopathic in 19) and asthmatic (n=14) causes and 15 healthy controls underwent fiberoptic bronchoscopy. Morphometry of bronchial biopsies and capsaicin cough sensitivity were assessed.

Results: Compared with controls, submucosal eosinophils and neutrophils were increased in patients with asthmatic cough (P<.005) and submucosal mast cells in patients with non-asthmatic cough (P=.01). Sub-basement membrane thickness, goblet cell area, vascularity, and vessel size were also increased in both groups. Smooth muscle area was higher only in patients with non-asthmatic cough (P=.0007 vs control and P=.019 vs asthmatic cough). None of the pathologic changes were related to the duration of coughing. Cough sensitivity was heightened in patients with non-asthmatic cough compared with controls and patients with asthmatic cough. The degree of goblet cell hyperplasia and epithelial shedding positively correlated with cough sensitivity in patients with non-asthmatic cough (r=0.43; P=.01; and r=0.40; P=.02, respectively).

Conclusion: Features of airway wall remodeling are prominent in the airways with non-asthmatic as well as asthmatic cough. These are linked to chronic cough rather than to asthma. Mast cell hyperplasia rather than eosinophilia is distinctive for non-asthmatic cough.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Asthma / complications
  • Asthma / immunology
  • Asthma / pathology
  • Bronchiectasis / complications
  • Bronchiectasis / immunology
  • Bronchiectasis / pathology
  • Bronchoscopy
  • Chronic Disease
  • Cough / etiology
  • Cough / immunology*
  • Cough / pathology*
  • Eosinophils / immunology
  • Female
  • Gastroesophageal Reflux / complications
  • Gastroesophageal Reflux / immunology
  • Gastroesophageal Reflux / pathology
  • Goblet Cells / pathology
  • Humans
  • Hyperplasia / pathology
  • Inflammation / immunology*
  • Inflammation / pathology
  • Lung / blood supply
  • Lung / immunology*
  • Lung / pathology*
  • Male
  • Mast Cells / immunology
  • Middle Aged
  • Muscle, Smooth / pathology
  • Neutrophils / immunology
  • Respiratory Mucosa / immunology
  • Respiratory Mucosa / pathology
  • Rhinitis / complications
  • Rhinitis / immunology
  • Rhinitis / pathology