Characteristics of patients with pulmonary non-tuberculous Mycobacterial infection in bronchiectasis: Data from the EMBARC registry

Introduction: Nontuberculous mycobacteria (NTM) are a common cause or complication of bronchiectasis (BE) but may be under-recognised. This study aimed to identify clinical factors associated with NTM infection in the EMBARC BE cohort. Methods: Prospective multicentre European Registry in 27 countries. Characteristics of patients with active or previous NTM infection were compared to patients with BE not due to NTM in whom NTM had been excluded by sputum culture. NTM pulmonary disease was defined by the ATS/IDSA criteria 2007. Results: 504 patients with a history of NTM (160 actively treated) were compared to 3593 patients without current NTM. 65.9% had Mycobacterium avium complex (16.3% M. abscessus complex 8.9% M. chelonae, others <5%). Patients with active NTM were older (mean 67 vs 63, p<0.0001 and more likely to be female (68.1% vs 58%, p=0.001). NTM patients had a lower mean BMI (22.7 vs 25.1, p<0.001). 54.4% of patients had involvement of the middle lobe and lingula bilaterally compared to 39.6% without NTM.(p<0.0001). In logistic regression, factors independently associated with NTM infection were age (OR 1.02 95% CI 1.101-1.03, p=0.005), female gender (OR 1.49 95% CI 1.03-2.14, p=0.03), MRC dyspnoea score (OR 1.26 95% CI 1.07-1.48, p=0.007) and bilateral involvement of the middle lobe and lingula OR 1.74 (95% CI 1.15-2.61, p<0.0001). Conclusion: European BE patients with NTM pulmonary disease are more likely to be older, female and have more symptoms and dyspnoea and bilateral middle lobe/lingula involvement. These parameters may be helpful to increase diagnosis rates of pulmonary NTM. Supported by EU/EFPIA IMI iABC grant agreement n° 115721.