title: Cryptogenic and secondary organizing pneumonia: clinical presentation, radiographic findings, treatment response, and prognosis.
abstract: BACKGROUND
  Organizing pneumonia (OP) is a distinct clinical and pathologic entity. This condition can be cryptogenic (COP) or secondary to other known causes (secondary OP). In the present study, we reviewed the features associated with COP and secondary OP in patients from two teaching hospitals.
  
  
  METHODS
  The medical records of 61 patients with biopsy-proven OP were retrospectively reviewed. Forty patients were diagnosed with COP and 21 patients with secondary OP. The clinical presentation, radiographic studies, pulmonary function tests (PFTs), laboratory data, BAL findings, treatment, and outcome were analyzed.
  
  
  RESULTS
  The mean age at presentation was 60.46 ± 13.57 years. Malaise, cough, fever, dyspnea, bilateral alveolar infiltrates, and a restrictive pattern were the most common symptoms and findings. BAL lymphocytosis was observed in 43.8% of patients with OP. The relapse rate and mortality rate after 1 year of follow-up were 37.8% and 9.4%, respectively. The in-hospital mortality was 5.7%. The clinical presentation and radiographic findings did not differ significantly between patients with COP and secondary OP. A mixed PFT pattern (obstructive and restrictive physiology) and lower blood levels of serum sodium, serum potassium, platelets, albumin, protein, and pH were observed among patients with secondary OP. Higher blood levels of creatinine, bilirubin, Paco₂, and BAL lymphocytes were also more common among patients with secondary OP. There were no differences in the relapse rate or mortality between patients with COP and secondary OP. The 1-year mortality correlated with an elevated erythrocyte sedimentation rate, low albumin, and low hemoglobin levels.
  
  
  CONCLUSIONS
  The clinical and radiographic findings in patients with COP and secondary OP are similar and nonspecific. Although certain laboratory abnormalities are more common in secondary OP and can be associated with worse prognosis, they are likely due to the underlying disease. COP and secondary OP have similar treatment response, relapse rates, and mortality.
authors: Third Pulmonary Medicine Department, Sismanoglion General Hospital, Maroussi, Greece.
authors: Fotios
authors: F
authors: Drakopanagiotakis
authors: Third Pulmonary Medicine Department, Sismanoglion General Hospital, Maroussi, Greece.
authors: Koralia
authors: K
authors: Paschalaki
authors: Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, Brown University, Providence, RI. Electronic address: Muhanned_Abu-Hijleh@Brown.edu.
authors: Muhanned
authors: M
authors: Abu-Hijleh
authors: Department of Pathology, Rhode Island Hospital-The Alpert Medical School of Brown University, Providence, RI.
authors: Bassam
authors: B
authors: Aswad
authors: Third Pulmonary Medicine Department, Sismanoglion General Hospital, Maroussi, Greece.
authors: Napoleon
authors: N
authors: Karagianidis
authors: Third Pulmonary Medicine Department, Sismanoglion General Hospital, Maroussi, Greece.
authors: Emmanouil
authors: E
authors: Kastanakis
authors: Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, Brown University, Providence, RI.
authors: Sidney S
authors: SS
authors: Braman
authors: Third Pulmonary Medicine Department, Sismanoglion General Hospital, Maroussi, Greece.
authors: Vlasis
authors: V
authors: Polychronopoulos
mesh_terms: D001706:Biopsy / Q000379:methods*; D001999:Bronchoscopy; D018549:Cryptogenic Organizing Pneumonia / Q000175:diagnosis* / Q000188:drug therapy / Q000401:mortality; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000627:therapeutic use*; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D018942:Macrolides / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013902:Radiography, Thoracic; D012008:Recurrence; D012129:Respiratory Function Tests / Q000379:methods*; D012189:Retrospective Studies; D012237:Rhode Island / Q000453:epidemiology; D016896:Treatment Outcome
chemical_list: D005938:Glucocorticoids; D018942:Macrolides