Pulmonary Nontuberculous Mycobacerial Disease In Elderly Patients

Objective: To investigate the clinical characteristics of pulmonary nontuberculous mycobacterial (NTM) disease in patients over 75 years old. Patients and Methods: The subjects consisted of 101 patients over 75 years old who satisfied the diagnostic criteria of ulmonary NTM disease proposed by ATS between 2008 and 2018. We evaluated the backgrounds, diagnostic methods, laboratory findings, radiological findings, treatments, and outcomes. Results: The average age was 80.5 years old (45 males, 56 females). Most patients had underlying diseases. The detectionmethods most frequently involved incidental identification of an abnormal shadow on radiological images during the follow-up periods for underlying diseases. A definite diagnosis was obtained by analysis of expectorated sputum in 55 patients, bronchoscopy in 42, and others in 4. The causative microorganisms consisted of M.avium in 44 patietns, M.intracellulare in 45, MAC in 5, and others in 7. Regarding laboratory findings, MAC antibody was elevated in 73% (56/77). Radiological findings were frequently bilateral, with lesions limited within unilateral lung fields. Centrilobular small nodules with bronchiectasis were recognized in 60%. Combined chemotherapy including CAM was administered to 52 of the 101 patients (51%). Thirty-two patients (62%) showed favorable efrfects. The outcome was comparatively good, but 22 of the 101 patients mostly died due to other underlying disease or pneumonia. Conclusions: The number of patients over 75 years old has recently increased with aging in Japan. Therefore, it may be appropriate to perform diagnosis and treatment for selected elderly patients with pulmonary NTM disease based on the results of this study.