Intestinal permeability in gastrointestinal disorders - Use of oral [^99mTc]DTPA

This study examined intestinal permeability in gastrointestinal disorders by measuring urinary recovery following oral administration of [^99mTc]DTPA in 117 subjects. The mean percent of the ingested dose excreted in a 24-hr urine sample was 2.8±1.6% in 11 healthy controls, 10.8±10.2% (P<0.001) in 21 ulcerative colitis patients, 8.0±4.7% (P< 0.001) in 35 Crohn's disease patients, 5.1±2.9% (P<0.01) in 17 patients with heterogeneous digestive disease diagnoses, and 3.2±4.7% (P>0.05) in 33 patients with hepatobiliary diagnoses. Among ambulatory patients, Crohn's disease subjects, but not ulcerative colitis patients, had greater urinary recovery than the controls (P<0.05). The Crohn's disease activity index correlated positively with the radionuclide recovery in Crohn's subjects (r=0.455, P<0.02). In a heterogeneous sample of subjects simultaneous ingestion of [^99mTc]DTPA and [⁵¹Cr]EDTA produced urinary levels that were correlated positively (r=0.556, P<0.001). Increased absorption of [^99mTc]DTPA relative to [⁵¹Cr]EDTA, however, was noted in ulcerative colitis patients (P<0.05). In conclusion, increased intestinal permeability has been demonstrated by utilizing [^99mTc]DTPA in Crohn's disease and ulcerative colitis patients. Although this observation appears to be a nonspecific indicator of injury, the test provides a simple objective means of establishing disease activity, which possibly may be utilized for therapeutic and investigative studies.