Pathogenesis

Microbial infection and dysfunctional immunity contribute to the pathophysiology of bronchiectasis (1).

Essential components of bronchiectasis include impaired mucociliary clearance and structural changes in the walls of the bronchi.

• The structural changes may be a consequence of impaired mucociliary clearance defects in ciliary motility, or, occur together

Acute severe lower respiratory infection, chronic low grade respiratory infection in an immunodeficient patient.

The majority of adult cases at present are due to severe respiratory childhood infection, such as measles or whooping cough.

• Bronchial obstruction may lead to bronchiectasis in the lung distal to the block e.g. due to tuberculous lymph nodes, carcinoma, foreign body.
• Proximal bronchiectasis may be seen in allergic aspergillosis.
• Bronchiectasis may also accompany congenitally atelectic lobes and ciliary dyskinesia.

Reference:

1. Chalmers JD, Chang AB, Chotirmall SH, Dhar R, McShane PJ. Bronchiectasis. Nat Rev Dis Primers. 2018 Nov 15;4(1):45. doi: 10.1038/s41572-018-0042-3.