Indium-111-labeled autologous leukocyte imaging and fecal excretion. Comparison with conventional methods of assessment of inflammatory bowel disease.

This study was designed to evaluate the role of 111In-labeled leukocyte imaging and fecal excretion in the assessment of inflammatory bowel disease. We compared these tests to various indices of disease activity in Crohn's disease, to Truelove's grading in ulcerative colitis, and to endoscopy, x-ray, and pathology in both diseases. Eleven controls, 16 patients with Crohn's disease, 13 with ulcerative colitis, and 3 with other types of acute bowel inflammation were studied (positive controls). Indium scanning was performed at 1, 4, and 24 hr. Fourteen of 16 patients with active Crohn's disease had positive scans but in only five was localization accurate. One patient had inactive ulcerative colitis, and the scan was negative. Of 12 patients with active ulcerative colitis, 10 had positive scans but disease localization was accurate in only four. Disease extent was correctly defined in 1 of the 3 Positive Controls. There was no significant difference in the accuracy of scanning at 1, 4, or 24 hr. 111In fecal excretion was significantly higher in patients with inflammatory bowel disease than in controls, and there was correlation between 111In fecal excretion and most of the indices of disease activity in Crohn's disease. In ulcerative colitis, 111In fecal excretion did not correlate with Truelove's grading but reflected colonoscopic assessment of severity. In conclusion, 111In-labeled leukocyte scanning lacks sensitivity with respect to disease extent, but fecal excretion of 111In correlates well with disease severity as determined by other methods.