ATS 2026: Bronchiectasis and NTM Pulmonary Disease Management

Bronchiectasis is a chronic respiratory condition characterized by permanent dilation of the bronchi and bronchioles, leading to recurrent respiratory infections and inflammation.¹ Its etiology is diverse, encompassing post-infectious causes, primary ciliary dyskinesia, cystic fibrosis, immunodeficiencies, and connective tissue diseases.² Nontuberculous mycobacteria (NTM) pulmonary disease is a significant and increasing cause of morbidity in patients with pre-existing lung conditions, including bronchiectasis.³ The ATS 2026 sessions addressed the intricate relationship between these conditions, focusing on diagnostic precision and therapeutic optimization.

Diagnosis of bronchiectasis relies on high-resolution computed tomography (HRCT) findings, demonstrating bronchial dilation and lack of tapering.¹ Identification of underlying etiologies is critical for targeted management. For NTM pulmonary disease, diagnosis requires a combination of clinical symptoms, radiographic evidence, and microbiological isolation of NTM from respiratory samples, adhering to established criteria.³ The sessions underscored the importance of distinguishing NTM colonization from active disease, as treatment for NTM pulmonary disease involves prolonged, multi-drug regimens with potential for significant adverse effects.⁴

Complex Case Management and Updated Guidelines

Management strategies for bronchiectasis aim to reduce exacerbations, improve lung function, and enhance quality of life. These include airway clearance techniques, bronchodilators, and long-term macrolide therapy in selected patients.⁵ The ATS 2026 discussions highlighted the challenges in managing patients with co-existing bronchiectasis and NTM pulmonary disease, where treatment decisions become particularly complex. For NTM pulmonary disease, updated guidelines from the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA) provide refined recommendations for species-specific treatment regimens.⁴ For instance, Mycobacterium avium complex (MAC) pulmonary disease, the most common NTM species, typically requires a macrolide-based regimen (e.g., azithromycin or clarithromycin) combined with ethambutol and rifampin.⁴ Treatment duration for MAC pulmonary disease is generally 12 months after culture conversion.⁴

The sessions also reviewed emerging therapies and novel approaches to managing refractory cases. This included discussions on inhaled antibiotics for chronic bronchial infection in bronchiectasis, such as inhaled tobramycin or aztreonam, which have demonstrated efficacy in reducing bacterial load and exacerbation frequency in specific patient populations.⁶ For NTM, the role of newer agents and combination therapies for drug-resistant strains was explored, though specific trial data were not detailed in the general session overview. The importance of a multidisciplinary team, including pulmonologists, infectious disease specialists, microbiologists, and physiotherapists, was emphasized for optimal patient outcomes, particularly in cases with complex microbiology or treatment intolerance.³

Limitations in current understanding include the precise mechanisms driving disease progression in a subset of patients and the identification of biomarkers predicting treatment response or disease exacerbation. Further research is needed to develop more targeted and less toxic therapies for NTM pulmonary disease and to better understand the interplay between various etiologies of bronchiectasis. The sessions concluded with a call for continued collaborative research to address these gaps and improve patient care.