111In-oxine marked leukocytes: a method for diagnosing the location and evaluating the activity of Crohn disease and ulcerative colitis

Patients with Crohn's disease (n = 22), ulcerative colitis (n = 5), inactive Whipple's disease (n = 1), irritable bowel syndrome (n = 2), arthritis (n = 1) and Yersinia infections (n = 2) were examined with 111In-oxine labelled "mixed" leukocyte preparations (n = 12) or with 111In-oxine labelled "pure" granulocyte preparations (n = 21). Compared with barium enemas of the gut and colonoscopy, performed within of one week in 31 patients there was a correct location of infiltrated bowel segments in 24 patients (78%). The scan diagnosed more infiltrated segments in 4 patients (13%). In 3 patients it failed to diagnose one inflamed segment. In 24 patients the faecal 111In-excretion was expressed as percentage of the reinjected 111In-activity. All patients with non inflammatory bowel diseases and patients with inactive inflammatory bowel diseases excreted less than 2% of the reinjected 111In-activity. All but one female patient with active bowel disease excreted more than 2%. In 24 patients the correlation of ESR, CDAI and A.I. was available. There was a good correlation between ESR (r = 0.77, P less than 0.001), A.I. (r = 0.61, p less than 0.001) and the %-faecal faecal excretion. The 111In-labelling of white blood cells, especially of granulocytes, seems to be a reliable alternative method to localize infiltrated bowel segments and to assess disease activity in patients with inflammatory bowel diseases, compared to usually performed radiological, endoscopical and clinical methods.