Airway remodelling

Changes in the structure of the airways in response to chronic inflammation

Airway remodelling refers to the structural changes that occur in the airways of individuals with chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD). These changes are a result of persistent inflammation and can lead to a progressive decline in lung function.

Pathophysiology

Airway remodelling involves several structural changes in the airways, including:

• Epithelial changes: The airway epithelium may become damaged and undergo changes such as goblet cell hyperplasia, which increases mucus production.
• Subepithelial fibrosis: There is an increase in the deposition of collagen and other extracellular matrix proteins beneath the epithelium, leading to thickening of the airway walls.
• Smooth muscle hypertrophy and hyperplasia: The smooth muscle layer of the airways becomes thicker due to an increase in the size and number of smooth muscle cells.
• Angiogenesis: There is an increase in the number of blood vessels in the airway walls, contributing to inflammation and edema.

Features of airway remodeling in asthma

Clinical Implications

Airway remodelling contributes to the clinical manifestations of chronic respiratory diseases. It can lead to:

• Airway narrowing: The structural changes reduce the diameter of the airways, increasing airway resistance and causing difficulty in breathing.
• Reduced lung function: Progressive remodelling can lead to a decline in lung function over time, as measured by spirometry.
• Increased airway hyperresponsiveness: The changes in airway structure can make the airways more sensitive to various stimuli, leading to bronchoconstriction.

Diagnosis

Airway remodelling is typically assessed using a combination of clinical evaluation, imaging studies, and pulmonary function tests. Bronchoscopy with biopsy can provide direct evidence of structural changes in the airways.

Management

The management of airway remodelling focuses on controlling the underlying inflammation and preventing further structural changes. This includes:

• Pharmacotherapy: The use of anti-inflammatory medications such as inhaled corticosteroids and bronchodilators to manage symptoms and reduce inflammation.
• Lifestyle modifications: Avoidance of triggers, smoking cessation, and regular exercise can help manage symptoms and improve lung function.
• Monitoring and follow-up: Regular monitoring of lung function and symptoms to adjust treatment as needed.

Related pages

• Asthma
• Chronic obstructive pulmonary disease
• Bronchial hyperresponsiveness
• Inflammation