NTM infection in bronchiectasis

Mat Zuki Mat Jaeb
Raja Perempuan Zainab II Hospital, Kota Bahru, Kelantan, Malaysia

Nontuberculous mycobacteria (NTM) infection is increasingly recognized as both a cause and consequence of bronchiectasis, forming a complex clinical interplay that challenges diagnosis and management. NTM pulmonary disease (NTM-PD) commonly presents with nodular bronchiectatic changes, particularly due to Mycobacterium avium complex (MAC) and Mycobacterium abscessus. Isolating NTM does not always indicate active disease, as colonization and transient infection are frequent. Diagnosis requires a combination of clinical symptoms, radiological findings, and microbiological confirmation from respiratory samples.

Bronchiectasis predisposes to NTM infection through impaired mucociliary clearance, altered mucus properties, immune dysfunction, and structural lung changes. Conversely, chronic NTM infection can exacerbate airway inflammation and lead to progressive bronchiectatic damage. Host risk factors include cystic fibrosis gene mutations, connective tissue disorders, immunodeficiencies either congenital or acquired and bronchial obstruction leading to localised bronchiectasis.

Management of NTM infection in bronchiectasis requires a patient-centered, multidisciplinary approach. Standard antimicrobial regimens are prolonged and often poorly tolerated, with suboptimal success rates. Treatment selection should be guided by species identification, disease severity, smear positivity, and host factors. New therapeutic strategies include rifamycin-free regimens, inhaled liposomal amikacin, and host-directed immunotherapies. Supportive careespecially airway clearance and nutritional optimization are crucial.

Due to diagnostic complexity and variable treatment response, not all patients with NTM infection require immediate antibiotic therapy. Understanding the interplay between host vulnerability and mycobacterial pathogenicity will be key to advancing personalized care for patients with bronchiectasis-associated.