Abstract
BackgroundCo-existence or subsequent isolation of multiple nontuberculous mycobacteria (NTM) species in same patient has been reported. However, clinical significance of these observations is unclear. The aim of this study was to determine clinical implications of changes of NTM species during or after treatment in patients with NTM lung disease.MethodsPatients with NTM lung disease, who experienced changes of NTM species during treatment or within 2 years of treatment completion between January 1, 2009 and December 31, 2015, were included in the analysis. Demographic, clinical, microbiological, and radiographic data were reviewed and analyzed.ResultsDuring the study period, 473 patients were newly diagnosed with NTM lung disease. Treatment was started in 164 patients (34.6%). Among these 164 patients, 16 experienced changes of NTM species during or within 2 years of treatment completion. Seven showed changes from M. avium complex (MAC) to M. abscessus subspecies abscessus (MAA) and five patients displayed changes from M. abscessus subspecies massiliense (MAM) to MAC. With isolation of new NTM species, 6 out of 7 patients with change from MAC to MAA reported worsening of symptoms, whereas none of the five patients with change from MAM to MAC reported worsening of symptoms. All MAA isolated during or after treatment for MAC lung diseases showed inducible resistance to clarithromycin.ConclusionsChange of NTM species may occur during or after treatment for NTM lung disease. Especially, changes from MAC to MAA is accompanied by symptomatic and radiographic worsening as well as inducible resistance to clarithromycin.
Highlights
Co-existence or subsequent isolation of multiple nontuberculous mycobacteria (NTM) species in same patient has been reported
Co-culture of M. avium complex (MAC) was reported among 20% of patients with M. abscessus subspecies abscessus (MAA)
Study population Among patients treated for NTM lung disease at Seoul National University Hospital between January 1, 2009 and December 31, 2015, patients with changes of NTM species during treatment or within 2 years of treatment completion were included in the analysis
Summary
Co-existence or subsequent isolation of multiple nontuberculous mycobacteria (NTM) species in same patient has been reported. The aim of this study was to determine clinical implications of changes of NTM species during or after treatment in patients with NTM lung disease. Nontuberculous mycobacteria (NTM) are ubiquitous in environments including natural or treated water and soil. They have a relatively low pathogenicity but can cause lung disease in immunocompetent as well as immunocompromised hosts. We have experienced several patients with NTM lung diseases in whom changes of NTM species was identified during or after treatment. The aim of this study was to determine the clinical implications of changes of NTM species during or after treatment completion in patients with NTM lung disease
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