[Abdominal scintigraphy with leukocytes marked with indium-111 in Crohn disease: clinical importance and prognostic usefulness]

: The exact role of 111In leukocyte scanning in the assessment of clinical activity of Crohn's disease (CD) is still a matter of controversy. In our center we studied 22 patients with CD (8 with active disease) with standard 111In labelled mixed leukocyte scans. We determined the extent of the lesion measured as lesion-occupied cells on scanned area and the degree of inflammatory activity assessed as count ratio between the involved region and the iliac crest. Particularly in delayed scans, these scintigraphic parameters showed good correlation with clinical and laboratory indices of disease activity. In our series, only 6 patients had completely negative scans. They were in clinical and laboratory remission, and 5 of them had undergone surgery for CD during the previous year, with no radiological and/or endoscopic findings of recurrence. Among the other 8 patients in clinical remission, 5 had positive early scans, while the rest showed persistent delayed images. Moreover both early and delayed leukocyte scans were positive in 8 cases in which disease was undoubtedly active. A 1-year follow-up was available for 14 patients in clinical remission when 111In-scan was performed. During this period, 3 patients, all of whom had had early and delayed positive 111In-scan, suffered from clinical relapse; no clinical relapses were documented in patients with only 4th hour positive scans. In conclusion, in our series, 111In-scan was also frequently positive in patients in clinical remission; in this patient subset persistent images on delayed scans might suggest the risk of clinical relapse.