Tracheobronchial amyloidosis. The Boston University experience from 1984 to 1999

Area of Science:

• Pulmonology
• Radiology
• Pathology

Background:

• Tracheobronchial amyloidosis (TBA) is an idiopathic disorder involving fibrillar protein deposition in the airways.
• Fewer than 100 cases of TBA have been reported, with limited long-term outcome data.
• This study presents the largest and most complete outcome reporting for TBA to date.

Purpose of the Study:

• To define the natural history of biopsy-proven tracheobronchial amyloidosis.
• To evaluate the utility of bronchoscopy, CT imaging, and PFTs in monitoring disease progression.
• To identify patterns of disease and factors associated with mortality.

Main Methods:

• Retrospective analysis of 10 patients with biopsy-proven TBA over 15 years.
• Prospective evaluation of 3 patients using bronchoscopy, CT imaging, and PFTs for up to 24 months.
• Longitudinal follow-up averaging 8 years for all patients.

Main Results:

• No patients developed systemic amyloidosis; no TBA cases found in patients with primary systemic amyloidosis.
• CT imaging effectively assessed airway narrowing and mural thickening, identifying three disease patterns (proximal, mid, distal).
• Severe proximal/mid airway disease correlated with decreased airflow and fixed obstruction; serial PFTs were most sensitive to progression.

Conclusions:

• CT imaging and serial PFTs provide the best assessment of airway involvement and disease progression in TBA.
• Bronchoscopy is crucial for diagnosis but limited in monitoring.
• While debulking procedures showed limited success, radiation therapy may offer future treatment potential.