title: Interstitial inflammatory lesions of the pulmonary allograft: a retrospective analysis of 2697 transbronchial biopsies.
abstract: BACKGROUND
  Parenchymal and bronchial inflammatory and fibrotic lesions other than acute cellular rejection (ACR) and lymphocytic bronchiolitis are prevalent; however, the context in which they appear is unknown, and often no specific treatment is instigated.
  
  
  OBJECTIVE
  To describe the prevalence, incidence and possible associations between commonly identified inflammatory and fibrotic lesions in the pulmonary allograft.
  
  
  METHODS
  Retrospective chart review of all transbronchial biopsies performed within the first 2 years of 299 lung-transplanted patients in the period 1996 to 2006.
  
  
  RESULTS
  A total of 2697 biopsies were evaluated corresponding to a mean of 6+/-2 (median 8) completed schedules per patient. Diffuse alveolar damage (DAD) was the second most common histological finding within the first 2 weeks after transplantation. The peak prevalence of bronchiolitis obliterans organizing pneumonia (BOOP) and interstitial pneumonitis occurred at 4 to 6 weeks, and 6 to 12 weeks, respectively. There was a steady increase in the cumulative proportion of patients with fibrosis and bronchiolitis obliterans, at each successive scheduled surveillance time point beyond 3 months posttransplantation. The strongest histological correlations were between ACR and lymphocytic bronchiolitis (OR 5.1, P<0.0001) or interstitial fibrosis (OR 3.2, P<0.0001). Patients with interstitial pneumonitis and pulmonary hemosiderosis were also more likely to demonstrate the finding of interstitial fibrosis (OR 3.0 and 3.7, P<0.0001, respectively). Acute cellular rejection was not associated with DAD, and patients with lymphocytic bronchiolitis were not more likely to demonstrate features of organizing pneumonia (DAD or BOOP).
  
  
  CONCLUSIONS
  Histologic findings of ACR, lymphocytic bronchiolitis, BOOP, and interstitial pneumonitis were directly associated with the development of interstitial fibrosis and bronchiolitis obliterans.
authors.affiliation: Division of Lung Transplantation, Department of Cardiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. cmburton@doctors.net.uk
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Burton
authors.forename: Martin
authors.initials: M
authors.lastname: Iversen
authors.forename: Jørn
authors.initials: J
authors.lastname: Carlsen
authors.forename: Claus B
authors.initials: CB
authors.lastname: Andersen
mesh_terms: D001706:Biopsy; D001980:Bronchi / Q000473:pathology*; D001992:Bronchoalveolar Lavage Fluid; D001999:Bronchoscopy; D018549:Cryptogenic Organizing Pneumonia / Q000473:pathology; D005260:Female; D016041:Heart-Lung Transplantation / Q000473:pathology; D006801:Humans; D015994:Incidence; D007249:Inflammation / Q000453:epidemiology / Q000473:pathology*; D008171:Lung Diseases / Q000145:classification / Q000601:surgery; D017563:Lung Diseases, Interstitial / Q000453:epidemiology / Q000473:pathology; D016040:Lung Transplantation / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000473:pathology; D011650:Pulmonary Alveoli / Q000473:pathology; D011658:Pulmonary Fibrosis / Q000453:epidemiology / Q000473:pathology; D012189:Retrospective Studies