Obstructive bronchiolar disease identified by CT in the non-transplant population: Analysis of 29 consecutive cases

Background and objective: Obstructive bronchiolar disease or constrictive bronchiolitis, particularly in non-transplant patients, is poorly understood. This study identified the associated diseases, presenting features, and clinical course of obstructive bronchiolar disease identified by CT in the non-transplant adult population. Methods: Retrospective single-centre study of 29 consecutive patients clinically diagnosed to have an obstructive bronchiolar disease based on the presence of respiratory symptoms and abnormal CT findings consisting of mosaic perfusion pattern with air trapping. Results: The median age was 54 years (range, 25-80 years); 20 were women (69%) and four patients (14%) had a smoking history. All 29 patients presented with respiratory symptoms, predominantly dyspnoea. The most common cause of obstructive bronchiolar disease was rheumatoid arthritis (34%). Other causes included hypersensitivity pneumonitis, multiple carcinoid tumorlets, Sjögren's syndrome, paraneoplastic pemphigus, inflammatory bowel disease and Swyer-James syndrome. The underlying cause was not identifiable in nine patients (31%), that is, cryptogenic constrictive bronchiolitis. An obstructive pattern was seen on pulmonary function testing in most patients (86%) with the exception of those with hypersensitivity pneumonitis and extreme obesity. Management usually included corticosteroid therapy, inhaled and oral, and bronchodilator therapy. Additional medications included macrolides, cytotoxic agents and other immunomodulator therapy. Pharmacologic therapy did not provide improvement in pulmonary function in the majority of patients but the follow-up data were limited. Conclusions: Diverse causes and underlying diseases are associated with obstructive bronchiolar disease diagnosed radiologically in the non-transplant adult population. Rheumatoid arthritis-associated and cryptogenic constrictive bronchiolitis are found in over one-half of these patients. Most patients with obstructive bronchiolar disease do not appear to improve with currently available therapy.