Cryptogenic Organizing Pneumonia

Introduction

• Definition
  • inflammation and fibrosis of the small airways (bronchioles) 
  • manifestation of chronic rejection in lung transplant  (and allogenic bone marrow transplant)
    • involves small bronchioles 
    • obstructive pattern on PFTs (reduced FEV1/ FVC)
  • major problem in lung transplant patients 
    • vasculature is relatively unaffected unlike other examples of chronic organ rejection
      • e.g. kidney
  • Other etiologies
    • viral infections
    • collagen vascular diseases
    • toxic fumes
    • rheumatoid arthritis
• Pathophysiology
  • lymphocytic inflammation of bronchiolar wall
  • damage replaced by fibrous tissue
  • progressive reduction in diameter of small airway lumens