Bonus Material-33_CHEST Board Review 2025NEW Bronchiectasis-NTM FINAL DAH

Pdf Summary

This comprehensive CHEST Board Review by Dr. Doreen Addrizzo-Harris focuses on non-cystic fibrosis (non-CF) bronchiectasis and nontuberculous mycobacterial (NTM) lung diseases, emphasizing pathophysiology, diagnosis, treatment strategies, and emerging therapies.<br /><br />Non-CF bronchiectasis involves irreversible bronchial dilation with mucus pooling, persistent infection, and inflammation. Diagnosis relies on clinical history, imaging (high-resolution CT), and lab tests including immunoglobulin levels, sputum cultures (bacterial, fungal, mycobacterial), sweat chloride for CF exclusion, and ciliary function testing. Management centers on airway clearance therapies (exercise, nebulized hypertonic saline, percussion, PEP devices) and in frequent exacerbators, long-term macrolides (azithromycin or erythromycin) reduce exacerbation rates through anti-inflammatory and antimicrobial effects; however, macrolide use requires pre-treatment NTM exclusion due to risk of promoting infection. Inhaled antibiotics (tobramycin, colistin, aztreonam) and the new FDA-approved neutrophil elastase inhibitor brensocatib (a DPP-1 inhibitor) show promise in reducing exacerbations and improving outcomes.<br /><br />NTM lung disease, primarily caused by Mycobacterium avium complex (MAC), is rising in US prevalence, especially in older adults with chronic lung conditions. Diagnosis mandates compatible chest CT findings plus multiple positive sputum or bronchoscopy cultures. Treatment of MAC varies by disease severity and radiographic pattern (fibronodular versus fibrocavitary), combining macrolides, ethambutol, and rifamycins either intermittently or daily depending on severity. Adherence to guideline-based therapy is crucial to prevent macrolide resistance, which can emerge with inappropriate regimens.<br /><br />For treatment-refractory MAC, options include inhaled amikacin liposome suspension (ALIS), clofazimine, bedaquiline, and possibly surgery. Surgery is also considered for localized disease or severe refractory cases with good outcomes.<br /><br />M. abscessus lung disease requires accurate subspecies identification and detection of the erm(41) gene due to inducible macrolide resistance influencing treatment choices. Multidrug regimens including amikacin, macrolides (if susceptibility confirmed), cefoxitin, imipenem, tigecycline, and others are used, often for prolonged durations. Surgery may improve outcomes in select cases.<br /><br />Key takeaways include the importance of accurate diagnosis through clinical, radiographic, and microbiologic assessment, individualized treatment regimens based on disease type and severity, the growing role of novel therapies such as brensocatib and ALIS, and early referral to expert centers to optimize management of complex NTM lung disease and non-CF bronchiectasis.

Meta Tag

Concept Non-CF Bronchiectasis

Concept Airway Clearance

Concept NTM Lung Disease

Concept Mycobacterium abscessus Lung Disease

Concept Etiology

Keywords

non-CF bronchiectasis

NTM lung disease

Mycobacterium avium complex

high-resolution CT

airway clearance

macrolide therapy

inhaled antibiotics

brensocatib

amikacin liposome suspension

erm(41) gene

Non-CF Bronchiectasis

Airway Clearance

NTM Lung Disease

Mycobacterium abscessus Lung Disease

Etiology