INCREASED PULMONARY AND INTESTINAL PERMEABILITY IN CROHNS-DISEASE

We tested the hypothesis that an increased epithelial permeability may affect sites other than the intestine in patients with Crohn's disease by simultaneously evaluating their pulmonary and intestinal permeability. Pulmonary and intestinal permeability were measured by clearance of inhaled technetium-99m diethylene triamine pentaacetate (Tc-99m-DTPA) and by urinary recovery of chromium-51 ethylene diamine tetraacetate respectively in 22 patients with Crohn's disease. The half time clearance of Tc-99m-dTPA from lung to blood (t1/2LB) was decreased - that is pulmonary permeability increased - in the whole group of patients with Crohn's disease as compared with 13 controls (median 45.5 minutes (8-160) v 85 minutes (34-130) (p < 0-003)). When analysed separately only patients with active Crohn's disease (n = 15) had a decreased t1/2 lung to blood v controls (42 minutes (8-160) v 85 minutes (34-130) (p < 0-0025)). Among patients with active Crohn's disease, six were studied again when their disease was quiescent and their t1/2 lung to blood did not differ significantly. The intestinal permeability was increased in the whole group of Crohn's disease patients as compared with 15 controls (5.25% (1.2-24) v 1.7% (0.65-5.75) (p < 0.0002)). When analysed separately both patients with active and inactive Crohn's disease had increased intestinal permeability v controls (8.1% (1.6-24) and 3.5% (1.2.9.2) v 1.7% (0.65-5.75)) (p < 0.0001, p = 0.05 respectively). Six patients with active Crohn's disease were studied again when their disease was quiescent and their intestinal permeability decreased significantly p < 0.04). Pulmonary permeability was increased in patients with Crohn's disease but was not greatly influenced by Crohn's disease activity as opposed to intestinal permeability. The mechanism of this increase is unknown, but may be related in some patients to the presence of an alveolitis.