title: 18 Cases of pulmonary Mycobacterium abscessus: Clinical difference depending on the presence or absence of Mycobacterium avium complex.
abstract: OBJECTIVE
  It can be difficult to treat respiratory tract infections caused by Mycobacterium abscessus (M. abscessus) as there is no established treatment strategy. Complications involving other nontuberculous mycobacterial infections such as Mycobacterium avium complex (MAC) are also commonly observed.
  
  
  METHODS
  We investigated the clinical background and course of 18 cases of pulmonary M. abscessus infection treated over 8 years at Kurashiki Central Hospital. Radiological evaluation was performed using NICE scoring system, a method of semi-quantitative evaluation of imaging findings of pulmonary MAC infection.
  
  
  RESULTS
  The mean age of the 18 patients (males, 6; females, 12) was 74.7 years. The median follow-up period was 1316 days (95% confidence interval; 720-1675 days), and 11 patients were concomitantly infected with pulmonary MAC. Among the patients that underwent antibacterial treatment for M. abscessus, there was one MAC-complication case and one non-MAC-complication case. All MAC-complication cases underwent antibacterial treatment including clarithromycin. Chest X-ray NICE scores for all cases were 8.50 ± 5.45 and 10.94 ± 6.03 at baseline and follow-up, respectively (p = 0.0063). For MAC-complication cases, scores were 8.36 ± 4.74 and 12.00 ± 6.02 at baseline and follow-up, respectively (p = 0.00818), and for non-MAC-complication cases, scores were 8.71 ± 6.82 and 9.29 ± 6.13 at baseline and follow-up, respectively (p = 0.356). MAC-complication cases were significantly further exacerbated than non-MAC-complication cases (p = 0.027).
  
  
  CONCLUSIONS
  Some cases of pulmonary M. abscessus infection progressed well without undergoing antibacterial treatment. In particular, results suggested that the clinical course of MAC-complication and non-MAC-complication cases differs.
authors.affiliation: Department of Respiratory Medicine, Kobe City Hospital Organization Kobe City Medical Center West Hospital, 2-4 Ichibancho, Nagata-ku, Kobe, Hyogo 653-0013, Japan; Department of Respiratory Medicine, Ohara Memorial Kurashiki Healthcare Foundation, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama 710-8602, Japan. Electronic address: k.furuta0113@gmail.com.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Furuta
authors.affiliation: Department of Respiratory Medicine, Ohara Memorial Kurashiki Healthcare Foundation, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama 710-8602, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ito
authors.affiliation: Department of Respiratory Medicine, Ohara Memorial Kurashiki Healthcare Foundation, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama 710-8602, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ishida
authors.affiliation: Department of Respiratory Medicine, Ohara Memorial Kurashiki Healthcare Foundation, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama 710-8602, Japan.
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Respiratory Medicine, Ohara Memorial Kurashiki Healthcare Foundation, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama 710-8602, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Sone
authors.affiliation: Department of Respiratory Medicine, Ohara Memorial Kurashiki Healthcare Foundation, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama 710-8602, Japan; Department of Respiratory Medicine, Sakai City Medical Center, 1-1-1 Ebarajicho, Nishi-ku, Sakai, Osaka 593-8304, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Takaiwa
authors.affiliation: Department of Respiratory Medicine, Ohara Memorial Kurashiki Healthcare Foundation, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama 710-8602, Japan.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Yokoyama
authors.affiliation: Department of Respiratory Medicine, Ohara Memorial Kurashiki Healthcare Foundation, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama 710-8602, Japan; Department of Respiratory Medicine, National Hospital Organization Minami Kyoto Hospital, 11 Ashihara, Joyo, Kyoto 610-0113, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Tachibana
authors.affiliation: Department of Respiratory Medicine, Ohara Memorial Kurashiki Healthcare Foundation, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama 710-8602, Japan.
authors.forename: Machiko
authors.initials: M
authors.lastname: Arita
authors.affiliation: Department of Respiratory Medicine, Ohara Memorial Kurashiki Healthcare Foundation, Kurashiki Central Hospital, 1-1-1 Miwa, Kurashiki, Okayama 710-8602, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Hashimoto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017291:Clarithromycin / Q000627:therapeutic use*; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy*; D015270:Mycobacterium avium-intracellulare Infection / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy; D009170:Nontuberculous Mycobacteria; D011859:Radiography; D012141:Respiratory Tract Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents; D017291:Clarithromycin
keywords: Coinfection; Japan; Mycobacterium abscessus; Mycobacterium avium complex; Nontuberculous mycobacteria