title: Progression and Treatment Outcomes of Lung Disease Caused by Mycobacterium abscessus and Mycobacterium massiliense.
abstract: BACKGROUND
  Mycobacterium abscessus and Mycobacterium massiliense are grouped as the Mycobacterium abscessus complex. The aim of this study was to elucidate the differences between M. abscessus and M. massiliense lung diseases in terms of progression rate, treatment outcome, and the predictors thereof.
  
  
  METHODS
  Between 1 January 2006 and 30 June 2015, 56 patients and 54 patients were diagnosed with M. abscessus and M. massiliense lung diseases, respectively. The time to progression requiring treatment and treatment outcomes were compared between the 2 groups of patients, and predictors of progression and sustained culture conversion with treatment were analyzed. In addition, mediation analysis was performed to evaluate the effect of susceptibility to clarithromycin on treatment outcomes.
  
  
  RESULTS
  During follow-up, 21 of 56 patients with M. abscessus lung diseases and 21 of 54 patients with M. massiliense lung diseases progressed, requiring treatment. No difference was detected in the time to progression between the 2 patient groups. Lower body mass index, bilateral lung involvement, and fibrocavitary-type disease were identified as predictors of disease progression. Among the patients who began treatment, infection with M. massiliense rather than M. abscessus and the use of azithromycin rather than clarithromycin were associated with sustained culture conversion. The difference in treatment outcomes was partly mediated by the organism's susceptibility to clarithromycin.
  
  
  CONCLUSIONS
  Progression rates were similar but treatment outcomes differed significantly between patients with lung disease caused by M. abscessus and M. massiliense. This difference in treatment outcomes was partly explained by the susceptibility of these organisms to clarithromycin.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Jimyung
authors.initials: J
authors.lastname: Park
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Jaeyoung
authors.initials: J
authors.lastname: Cho
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Sung Koo
authors.initials: SK
authors.lastname: Han
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea yimjj@snu.ac.kr.
authors.forename: Jae-Joon
authors.initials: JJ
authors.lastname: Yim
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017963:Azithromycin / Q000494:pharmacology / Q000627:therapeutic use; D017291:Clarithromycin / Q000494:pharmacology* / Q000627:therapeutic use; D018450:Disease Progression; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000175:diagnosis / Q000188:drug therapy* / Q000382:microbiology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis / Q000188:drug therapy* / Q000382:microbiology*; D009170:Nontuberculous Mycobacteria / Q000187:drug effects* / Q000302:isolation & purification; D012189:Retrospective Studies; D012307:Risk Factors; D013183:Sputum / Q000382:microbiology; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin; D017291:Clarithromycin
keywords: 
  Mycobacterium abscessus
  ; 
  Mycobacterium massiliense
  ; disease progression; nontuberculous mycobacteria; treatment outcome.