A Prospective Comparison of 99m Tc-Labeled Polyclonal Human Immunoglobulin and 111 In Granulocytes for Localization of Inflammatory Bowel Disease

Abstract

There is a need for an easily prepared radiopharmaceutical agent for the detection of inflammation and infection. In a group of 14 patients with inflammatory bowel disease (IBD), the detection of actively involved intestinal segments by nonspecific human polyclonal immunoglobulin (IgG) labeled with ^99mTc was compared with that of ¹¹¹In granulocytes. To determine the specificity of ^99mTc-IgG scintigraphy, 8 control patients without clinical indications of intestinal inflammation were examined. ^99mTc-IgG was found in the left colon in 8 and in the right colon in 7 of the 8 controls 4 hours after the injection. At that time of scintigraphy only 4 IBD patients exhibited a more intense accumulation at the site of the intestinal segments with active disease. In contrast, in a randomized comparison with ¹¹¹In granulocytes scintigraphy was positive in 11 patients with the latter technique. Moreover, fewer diseased segments were seen in the 4 patients with positive ^99mTc-IgG scintigraphy (6 versus 12 with ¹¹¹In granulocytes). In view of the low sensitivity and specificity, it is concluded that ^99mTc-IgG is not suitable for the scintigraphic staging of IBD patients.