Diagnostic possibilities and clinical indications of policlonal labeled Ig in the bowel inflammatory disease

BACKGROUND/AIMS: Ulcerative colitis (UC) and Crohn's disease (CD) represent the more common forms of idiopathic inflammatory bowel disease. They have a peculiar course, which is characterized by exacerbation and submissions, and a symptomatology that changes in relation to severity and extension of the lesions. The aim of this study is to establish the diagnostic usefulness of 99m Tc human policlonal immunoglobulin (HIG) imaging in patients with inflammatory bowel disease (IBD). METHODOLOGY: During the period between September 1995 and September 1997 we submitted a group of 32 patients affected by UC (n = 22) and CD (n = 10), to Human Immunoglobulin labeled with Technetium 99m (99m Tc-HIG) scintigraphy. The diagnosis of IBD was obtained in all cases by endoscopy with biopsy. RESULTS: Scintigraphic examination with labeled HIG showed an abnormal intestinal fixation (ileal or colic) of the marked immunoglobulins in 17 patients (77.2%) affected by UC and in 8 patients (80%) affected by CD. In 5 (22.7%) and 2 (20%) patients, respectively, the scintigraphic examination revealed a normal distribution of the immunoglobulins without appreciable focal accumulation. Among the patients with a negative scintigraphic examination, only one presented an endoscopic and histologic report that documented UC in an active stage. The histologic and endoscopic findings observed in all cases of CD were similar to that of HIG scintigraphy in 7 of the 8 scintigraphic-positive cases and in 1 of the 2 scintigraphic-negative patients. CONCLUSIONS: The authors, on the basis of their results, suggest that this diagnostic strategy may have a significant role in the diagnostic protocol and in the follow-up of chronic inflammatory bowel disease.