ENDOSCOPY, RADIOLOGY, TC-99M-EXAMETAZINE LABELED LEUKOCYTES AND IN-111 LABELED HUMAN POLYCLONAL IMMUNOGLOBULIN-G SCINTIGRAPHY IN THE DIAGNOSIS OF INFLAMMATORY BOWEL-DISEASE - A COMPARATIVE-STUDY

BACKGROUND: The Tc-99m-exametazine labelled leukocytes (Tc-99m-WBC) sc intigraphy is an established method for the inflammatory bowel disease (IBD) diagnosis, but the labelled procedure is a large and laborious process. The (111)ln-labelled human polyclonal immunoglobulin G ((111) ln-IgG) can be an alternative in the non invasive IBD diagnosis. PATIE NTS AND METHODS: Thirty-four patients routinely referred for investiga tion of IBD were studied. The Tc-99m-WBC and (111)ln-IgG were simultan eously injected and images were obtained at 30 min, 3 and 24 h post-in jection. The diagnostic was established by histology of endoscopy and/ or surgery samples. Images were blindly evaluated by two experienced o bservers who only knew of the clinical suspicion of IBD. IBD was confi rmed in 27 patients (17 with Crohn's disease [CD] and 10 with ulcerati ve colitis [UC]). RESULTS: Sensitivity, specificity and accuracy were 88.5, 100 and 90.3% respectively for endoscopy, 73.7, 75 and 73.9% for radiology, 59.3, 85.7 and 64.7% for (111)ln-IgG scan and 96.3, 85.7 a nd 94.1% for Tc-99m-WBC scan. In the diagnosis of CD involvement of sm all bower, the Tc-99m-WBC scan identified 9/11 patients with confirmed disease, whereas the (111)ln-IgG scan diagnosed only four of them. In the evaluation of colonic disease, the (TC)-T-99m-WBC scan correctly diagnosed 21/22 confirmed patients, being the (111)ln-IgG scan positiv e in 13 of them. As far as disease extension concerned, the Tc-99m-WBC demonstrated a statistically significance rather number of disease se gments than endoscopy, radiology and (111)ln-IgG scan. CONCLUSIONS: Th e Tc-99m-WBC was an effective method in the diagnosis of suspected IBD patients, both in the evaluation of small bowel disease and colonic d isease, with slightly best results for colonic disease, whereas the (1 11)ln-IgG scan seems to have no utility neither in diagnosis nor in ex tension evaluation of IBD.