title: Increasing patients with pulmonary Mycobacterium avium complex disease and associated underlying diseases in Japan.
abstract: This study was conducted to evaluate trends in the isolation of strains of nontuberculous mycobacteria (NTM) and trends in the number of patients with pulmonary Mycobacterium avium complex (MAC) disease. We retrospectively reviewed microbiological results and clinical data to identify patients who were diagnosed with pulmonary MAC disease at Kyoto University Hospital in Japan between 2000 and 2013. NTM were isolated from 6327 of 80,285 samples (7.9%) for mycobacterial culture. The proportion of NTM isolates among all mycobacterial isolates increased from 355 of 792 samples (44.8%) in 2000 to 688 of 847 samples (81.2%) in 2013. MAC was most frequently observed (5436 isolates, 85.9%), followed by Mycobacterium abscessus (175 isolates, 2.8%) and Mycobacterium kansasii (74 isolates, 1.2%). A total of 592 patients with pulmonary MAC disease were identified (age, 66.0 ± 11.5 years; females, 61.1%). Compared with the early cohort (2000-2006, 236 patients), more patients in the late cohort (2007-2013, 356 patients) had an underlying disease (157 [66.5%] vs. 284 [79.8%], P = 0.0003), a Charlson comorbidity index score ≥ 1 (115 [48.7%] vs. 213 [59.8%], P = 0.008), collagen vascular disease (18 [7.6%] vs. 60 [16.9%], P = 0.001), rheumatoid arthritis (11 [4.7%] vs. 41 [11.5%], P = 0.004), and used immunosuppressive drugs (22 [9.3%] vs. 63 [17.7%], P = 0.004). The numbers of patients with lung disease, malignant disease and diabetes mellitus increased; however, their frequencies did not differ. The recovery rate of NTM and patients with pulmonary MAC disease increased, especially in patients with collagen vascular disease or rheumatoid arthritis or who used immunosuppressive drugs.
authors: Department of Respiratory Medicine, Kyoto University, Kyoto, Japan; Department of Respiratory Medicine, Allergy and Clinical Immunology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. Electronic address: yutaka@med.nagoya-cu.ac.jp.
authors: Yutaka
authors: Y
authors: Ito
authors: Department of Respiratory Medicine, Kyoto University, Kyoto, Japan.
authors: Toyohiro
authors: T
authors: Hirai
authors: Division of Respiratory Medicine, National Hospital Organization Kyoto Medical Center, Kyoto, Japan.
authors: Kohei
authors: K
authors: Fujita
authors: Division of Respiratory Medicine, Takeda General Hospital, Kyoto, Japan.
authors: Koichi
authors: K
authors: Maekawa
authors: Department of Respiratory Medicine, Allergy and Clinical Immunology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors: Akio
authors: A
authors: Niimi
authors: Clinical Laboratory of Medicine, Kyoto University, Kyoto, Japan.
authors: Satoshi
authors: S
authors: Ichiyama
authors: Department of Respiratory Medicine, Kyoto University, Kyoto, Japan.
authors: Michiaki
authors: M
authors: Mishima
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000453:epidemiology; D015897:Comorbidity / Q000639:trends; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007564:Japan / Q000453:epidemiology; D008171:Lung Diseases / Q000453:epidemiology* / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D015269:Mycobacterium avium Complex / Q000302:isolation & purification*; D015270:Mycobacterium avium-intracellulare Infection / Q000453:epidemiology* / Q000382:microbiology*; D019909:Mycobacterium kansasii / Q000302:isolation & purification; D012189:Retrospective Studies; D012737:Sex Factors; D014652:Vascular Diseases / Q000453:epidemiology
chemical_list: D007166:Immunosuppressive Agents
keywords: Collagen vascular disease; Mycobacterium avium complex; Nontuberculous mycobacteria; Rheumatoid arthritis