Comparative study of clinical features between elderly and non-elderly patients with pulmonary nontuberculous mycobacterial disease

<b>Objective:</b> To compare the clinical features between elderly amd non-elderly patients with pulmonary nontuberculous mycobacterial (NTM) disease. <b>Patients:</b> The subjects consisted of 114 patients over 75 years (elderly) and 193 patients under 74 years (non-elderly) with pulmonary NTM disease diagnosed with criteria proposed by ATS between 2008 and 2019. <b>Results:</b> The ratio of males/females was higher in elderly than non-elderly patients. The presence of underlying diseases was more frequent in elderly than non-elderly patients. The detection method frequently involved periodical health examinations in non-elderly patients and bronchoscopy was positively performed for a definite diagnosis. Regarding laboratory findings,&nbsp;the positive response rate of MAC antibody was similar in&nbsp;both patient groups. The causative microorganism was frequently M.intracellulare in elderly patients and M.kansasii in non-elderly patients. Although small nodules with bronchiectasis were frewuntly noted in non-elderly patients as radiological findings, there were no significant differences. Combined chemotherapy including CAM was performed for 55% of elderly patients and 73% of non-elderly patients. However, there were no significant differences in clinical efficacy rates or adverse reactions. <b>Conclusions:</b> Combined chemotherapy was performed for elderly patients with a good&nbsp;performance status (PS) and pulmonary NTM disease, achieving a favorable clinical effect equal in that of non-elderly patients. Therefore, it may be appropriate to actively perform diagnosis and treatment for elderly patients with pulmonary NTM disease showing a good PS.