Factors Predisposing to Non-Tuberculous Mycobacterial Lung Disease in the Patients with Respiratory Isolates of Non-Tuberculous Mycobacteria

Introduction: An increasing incidence rate of respiratory isolates of non-tuberculous mycobacteria (NTM) has been noted recently in most European countries as well as in the US. Despite many publications, there is no consensus concerning the importance of different factors in promoting NTM lung disease (NTMLD). The aim of the present retrospective study was to analyse patients with positive NTM respiratory isolates in search of factors predisposing to NTMLD. Material and methods: 73 patients, 23 males, 50 females, median age 62.2 years, in whom NTM have been cultured from respiratory specimen (sputum and/or bronchial washings), in the period 2010–2015, entered the study. Results: NTMLD (according to ATS/IDSA) has been recognised in 36 patients, airways colonisation by NTM—in 37 patients. NTMLD was diagnosed more often in the patients infected with M. kansasii, M. abscessus and M. avium/M. intracellulare comparing to those infected with M. xenopi, M. gordonae and M. fortuitum (p < 0.0001). The proportion of females to males was significantly higher in the NTMLD group comparing to the colonisation group (p < 0.007). Previous tuberculosis or mycobacteriosis were noted significantly more frequently in the group of patients with NTMLD comparing to the colonisation group (28% vs. 8%, p = 0.038). Univariate regression analysis revealed M. kansasii, female gender, and previous tuberculosis or mycobacteriosis as significant predictors of NTMLD. Conclusions: The risk factors of NTMLD recognition in the presented group of patients were the following: female gender, M. kansasii isolation, as well as past tuberculosis or mycobacteriosis.