Pulmonary function tests and high-resolution CT in the detection of pulmonary involvement in inflammatory bowel disease.

Abstract

To assess the pulmonary involvement detected by pulmonary function tests (PFT) and high-resolution computed tomography (HRCT) in inflammatory bowel disease (IBD) patients and to investigate the relationship of the pulmonary abnormalities with respiratory symptoms and bowel disease activity. 23 patients with ulcerative colitis, 13 patients with Crohn disease and 14 control subjects took part in this prospective, controlled study. In all patients, detailed clinical information was obtained and extent and activity of the bowel disease were established. Each patient underwent PFT and HRCT scanning. A pulmonary function abnormality was present in 21 of 36 patients. In IBD patients, DLCO were significantly lower, but RV/TLC was significantly higher than those of controls. HRCT revealed air trapping, fibrosis, emphysema, bronchiectasis and alveolitis in 19 patients. One-third of the patients with PFT abnormality, and 42% of the patients with HRCT abnormality were respiratory symptom free. Approximately 80% of the patients with pulmonary involvement had active bowel disease. Pulmonary involvement is common in patients with IBD. A high degree of suspicion is necessary to detect the pulmonary abnormality in IBD, because considerably large proportions of the symptom free patients have abnormal findings on HRCT and PFT.