Causes of Cystic Bronchiectasis with Central Distribution

Primary Causes of Central Cystic Bronchiectasis

The American Thoracic Society recommends that ABPA is characterized by immune-mediated inflammation in response to inhaled Aspergillus fumigatus antigen, causing central bronchiectasis (inner two-thirds of chest on CT scan) 1
Essential diagnostic criteria for ABPA include central distribution of bronchiectasis, asthma, immediate cutaneous reactivity to Aspergillus antigen, elevated total serum IgE level, and elevated serum levels of IgG-A fumigatus or IgE-A fumigatus 1
Cystic fibrosis is one of the most common identifiable causes of bronchiectasis in the United States and Europe, occurring in 1 per 2,000-3,000 live births, and is caused by mutation of the gene encoding the CF transmembrane regulator protein 3
Primary ciliary dyskinesia is a genetic disorder affecting ciliary structure and function, leading to impaired mucociliary clearance, and causes recurrent sinopulmonary infections and bronchiectasis, often with central distribution 4, 5
MAC infection can cause a clinicopathologic subtype of chronic pulmonary infection predominantly in white women in their seventh or eighth decade, and can be the primary disorder leading to progressive airway damage and bronchiectasis 1

High-resolution CT scanning is the diagnostic procedure of choice to confirm bronchiectasis, with sensitivity and specificity exceeding 90%, according to the American College of Radiology 3
Key features on HRCT include enlarged internal bronchial diameter, failure of larger airways to taper while progressing to the lung periphery, and air-fluid levels in dilated airways 3, 6

Early diagnosis and intervention are important to potentially reverse bronchial wall dilatation in early disease, and treatment should target the underlying cause when identified, as recommended by the European Respiratory Society 2, 4, 5
For ABPA, corticosteroid treatment may be beneficial, and for MAC infection, treatment with a macrolide, ethambutol, and a rifamycin is considered first-line therapy for patients with severe or progressive symptoms, according to the Infectious Diseases Society of America 1, 3