title: Comparison between cryptogenic organizing pneumonia and connective tissue disease-related organizing pneumonia.
abstract: OBJECTIVE
  Although the overall prognosis of CTD-related interstitial pneumonia is better than that of idiopathic interstitial pneumonia, the prognosis of CTD-related organizing pneumonia (CTD-OP) was suggested to be worse than that of cryptogenic organizing pneumonia (COP). The aim of this study was to compare the clinical features and outcome of the two conditions.
  
  
  METHODS
  A retrospective review of 100 patients diagnosed by lung biopsy as having organizing pneumonia patterns (CTD, 24; COP, 76) at three tertiary referral centres.
  
  
  RESULTS
  Underlying CTDs were mostly RA, SS and PM/DM. The median follow-up period was 43.6 months. There were no differences in initial symptoms, lung function or bronchoalveolar lavage fluid findings except significantly more females (83.3 vs. 59.2%, P = 0.048) in the CTD-OP than in the COP group. Over 80% of the patients in both the groups improved. However, complete recovery rate was lower in CTD-OP (20.8%) than in COP (46.1%; P = 0.028) with a tendency towards higher recurrence rate in CTD-OP (40.0 vs 20.3%; P = 0.072). There was no significant difference in the frequency of rapid progression or overall survival between the two groups.
  
  
  CONCLUSIONS
  The clinical features and prognosis of CTD-OP are similar to COP. However, lower complete recovery rate with a tendency towards higher recurrence rate in CTD-OP compared with COP suggest the need for closer follow-up in patients with CTD-OP.
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Asan Medical Center, College of Medicine, University of Ulsan, 388-1, Pungnap-2dong, Songpa-gu, Seoul, South Korea.
authors.forename: Jung-Wan
authors.initials: JW
authors.lastname: Yoo
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Song
authors.forename: Se Jin
authors.initials: SJ
authors.lastname: Jang
authors.forename: Chang Keun
authors.initials: CK
authors.lastname: Lee
authors.forename: Mi-Young
authors.initials: MY
authors.lastname: Kim
authors.forename: Hyun-Kyung
authors.initials: HK
authors.lastname: Lee
authors.forename: Yangjin
authors.initials: Y
authors.lastname: Jegal
authors.forename: Dong Soon
authors.initials: DS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D003240:Connective Tissue Diseases / Q000150:complications*; D018549:Cryptogenic Organizing Pneumonia / Q000175:diagnosis / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology*; D011379:Prognosis; D012008:Recurrence; D012129:Respiratory Function Tests; D012189:Retrospective Studies