Non-tuberculous mycobacteria (NTM) and COPD: a multicentre prospective study

Area of Science:

• Pulmonology
• Infectious Diseases
• Microbiology

Background:

• Airway isolates of non-tuberculous mycobacteria (NTM) are increasing, particularly in patients with pre-existing lung damage.
• Inhaled corticosteroids may elevate the risk of NTM lung disease.
• Data on NTM isolation prevalence in chronic obstructive pulmonary disease (COPD) patients are limited.

Purpose of the Study:

• Determine NTM isolation prevalence and NTM pulmonary disease incidence in high-risk COPD patients per ATS/ERS/IDSA 2020 criteria.
• Identify risk factors for NTM isolation and NTM pulmonary disease development in COPD patients.

Main Methods:

• Prospective, multicenter, observational study.
• Collected three sputum samples annually for culture (standard, mycobacteria, fungi) from high-risk COPD patients.
• Included patients with postbronchodilator FEV1<50% and/or ≥2 exacerbations/year, with 12-month follow-up.

Main Results:

• NTM was isolated in 15% (39/258) of patients; 3% (8/258) met criteria for NTM disease.
• Mycobacterium avium complex (MAC) was the most common species.
• Risk factors for NTM isolation: low body weight, alpha-1 antitrypsin (AAT) deficiency, inhaled corticosteroids, cancer.
• NTM disease associated with body mass index <21.

Conclusions:

• NTM isolation is more common than anticipated in COPD patients, impacting treatment decisions.
• Low body weight, AAT deficiency, inhaled corticosteroid use, and cancer are associated with NTM isolation in COPD.