Systemic corticosteroid and inhalation corticosteroid therapy are associated with nontuberculous mycobacterial pulmonary disease

Abstract

Background: Factors contributing to the development of nontuberculous mycobacterial pulmonary disease (NTM-PD), as opposed to NTM colonization, are largely unknown.

Aims and objectives: to assess differences between patients colonized with NTM and those with NTM-PD and identify possible factors that may favor the disease.

Methods: Retrospective analysis of the data from the Croatian national registry of all NTM isolates. We included all patients with pulmonary NTM isolates in the period from 2006 through 2013 (follow up until 01-01-2015) that had complete medical records data. The American Thoracic Society criteria were used to diagnose NTM-PD.

Results: We identified 414 patients (65.5% males) with complete records; 135 had NTM-PD, 279 were only colonized. Overall median follow up was 35.7 months. COPD was the most common comorbidity (176/414; 42.5%). 44 and 60 patients were on inhalation corticosteroid therapy (ICS) in NTM-PD and colonization group, respectively. ICS therapy was significantly associated with NTM-PD (OR 2.5, P=0.003); sub-analysis only showed significance for high doses (≥840 µg beclomethasone) of ICS. Long term systemic corticosteroid therapy (10 and 7 patients in the NTM-PD and colonization group, respectively; OR 3, P=0.02) was also associated with NTM-PD. Patients with NTM-PD had significantly lower average body mass index (BMI) than colonized patients (20 and 24 kg/m², respectively; p<0.0001).

Conclusion: High doses ICS and long term systemic corticosteroids therapy may be risk factors to develop NTM-PD. Lower BMI may be a cause, but also an effect of NTM-PD.