Bronchiolar Complications of Connective Tissue Disorders

A spectrum of inflammatory and fibrotic disorders involving the small air ways (i.e., respiratory and terminal bronchioles) may complicate connective tissue disor ders (CTDs). Obliterative (constrictive) bronchiolitis (OB) is a well-recognized, albeit rare, complication of rheumatoid arthritis, and occasional cases have been described in other CTDs. Bronchiolitis obliterans with organizing pneumonia (BOOP), also termed crypto genic organizing pneumonia, is a rare complication of CTDs. Clinical, radiographic, histo logical features and prognosis differ markedly between these entities. Clinical features are nonspecific, and the diagnosis (particularly OB) may be difficult. High resolution thin section computed tomographic (HRCT) scans are useful in detecting bronchiolar pathol ogy, even when symptoms are minimal or absent. Surgical (open or thoracoscopic) lung biopsies can substantiate the diagnosis, but in some cases, the diagnosis can be affirmed less aggressively by appropriate imaging studies (e.g., HRCT) and transbronchial lung biopsies. Corticosteroids are highly efficacious for BOOP, but therapeutic options for OB are disappointing.