DR Medhat MRCP

Bronchiolitis oblitrans(BO)
- Progressive irreversible airway obstruction due to sub-mucosal bronchiolar fibrosis &
collagen deposition leading to obliteration of the airway.
• Causes :
1) In heart-lung transplantation : this is the main cause , lead to allograft rejection.
2) Connective tissue disease (especially Rhoid arthritis) : 1 st cause in non-transplant pt.
3) Less common causes Inhalation of toxic fumes.
Infection (viral,mycoplasma).
Drugs (radiation , penicillamine)
Ulcerative colitis.
• Clinical picture :
1) Often non-specific & insidious.
2) Dyspnea on exertion : is the most common symptom.
3) Hyperinflation signs , end expiratory wheezes & crackles.
• Investigations :
1) CXR : hyperinflation ± fibrosis.
2) HRCT : bronchial wall thickening with mosaic perfusion.
3) Lung biopsy : the only method for definite diagnosis.
4) PFT : ↓↓FEV1 , FEV1/FVC < 0.7 ,↑ RV, normal DLCO.
• Treatment :
No reliable therapy (poor response to steroids).
• Prognosis :
Generally poor : slow progression to death within 1 year.
Overall mortality 25-55% : mainly from infection & respiratory failure.