title: Clinical features in secondary and cryptogenic organising pneumonia.
abstract: METHODS
  The clinical differences between cryptogenic organising pneumonia (COP) and secondary organising pneumonia (OP) have not been studied well.
  
  
  OBJECTIVE
  To compare clinical features in COP and secondary OP.
  
  
  METHODS
  Causes, clinical features, treatment, radiographic studies and pathology were studied.
  
  
  RESULTS
  After re-evaluation, 104 patients fulfilled the diagnostic criteria, 58 for COP and 46 for secondary OP. The mean age was 68 years. Most of the patients were smokers (79/104). Infections were the most common causes of secondary OP (21/46). Cough was the most common symptom and crackles the most common sign. Crackles were more common in patients with secondary OP (P = 0.02). Transbronchial biopsy was the diagnostic test in 81/104 cases. Most patients had lowered partial oxygen pressure (PO(2)) and mildly restrictive spirometry, with no differences between the two groups. Radiographic features were similar. Corticosteroids were the treatment in 70% of the patients, but 27% received no pharmacological treatment. The average initial dose of steroids was 42 mg prednisolone, and was similar for both groups. Relapses were seen in 20% of cases, with no difference between the two groups.
  
  
  CONCLUSIONS
  There were no major differences in clinical features of COP and secondary OP, except that crackles were more common in secondary OP.
authors.affiliation: Department of Respiratory Medicine, Sleep and Allergy, Landspitali University Hospital, Reykjavik, Iceland.
authors.forename: O A
authors.initials: OA
authors.lastname: Sveinsson
authors.forename: H J
authors.initials: HJ
authors.lastname: Isaksson
authors.forename: A
authors.initials: A
authors.lastname: Sigvaldason
authors.forename: F
authors.initials: F
authors.lastname: Yngvason
authors.forename: T
authors.initials: T
authors.lastname: Aspelund
authors.forename: G
authors.initials: G
authors.lastname: Gudmundsson
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000368:Aged; D001424:Bacterial Infections / Q000150:complications; D003371:Cough / Q000209:etiology; D018549:Cryptogenic Organizing Pneumonia / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D011859:Radiography; D012008:Recurrence; D012129:Respiratory Function Tests; D012135:Respiratory Sounds / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D016896:Treatment Outcome; D014777:Virus Diseases / Q000150:complications
chemical_list: D000305:Adrenal Cortex Hormones