Bronchiectasis

Description

Bronchiectasis is an irreversible syndrome with symptoms of chronic productive cough and recurrent exacerbations and with characteristic findings on cross-sectional imaging of bronchial wall dilation and thickening.

Epidemiology

Prevalence

• Overall estimated prevalence of bronchiectasis in the United States is 701 per 100,000 (1).
• Prevalence is higher among women than men and increases with age.

Etiology and Pathophysiology

• Bronchiectasis often arises as a complication of inherited or acquired disease states but may arise as an isolated diagnosis.
• Vicious cycle hypothesis (1):
  • An initial pulmonary insult causes airway inflammation, dysfunction, and structural disease.
  • Dysfunctional airways are further impaired in their ability to clear infections.
  • A pattern of lung damage/inflammation and progressive airway dysfunction is established, leading to clinical decline.
• Neutrophil extracellular traps (NETs) levels and neutrophil elastase activity correlate with disease activity and may serve as potential therapeutic targets (1).

General Prevention

• Routine immunization against respiratory infections (pertussis, measles, Haemophilus influenzae type B [HIB], influenza, and Streptococcus pneumonia).
• Early recognition and treatment of respiratory disease, inflammatory disease, and other predisposing conditions
• Genetic counseling for patients with inheritable conditions which predispose to bronchiectasis who wish to conceive
• Encourage and support smoking cessation in all patients who smoke

Commonly Associated Conditions

• Many cases are idiopathic, and bronchiectasis may be an isolated pulmonary diagnosis.
• Acquired conditions associated with bronchiectasis:
  • Pneumonia
  • GERD
  • Asthma/chronic obstructive pulmonary disease (COPD)
  • Rheumatologic conditions (rheumatoid arthritis, IBD)
  • Tuberculosis (TB)
  • Allergic bronchopulmonary aspergillosis (ABPA)
  • Chronic rhinosinusitis
  • Focal airway obstruction
• Inherited conditions associated with bronchiectasis:
  • Cystic fibrosis
  • Primary ciliary dyskinesia
  • Congenital abnormalities of the airways (e.g., tracheobronchomalacia, Mounier-Kuhn syndrome)
  • α1-Antitrypsin deficiency