HM-PAO-labeled leukocyte scintigraphy in pediatric patients with inflammatory bowel disease

Leukocyte scintigraphy (LS) was performed in 20 pediatric patients with inflammatory bowel disease (IBD: 10 with ulcerative colitis, 2 with indeterminate colitis, and 8 with Crohn disease) in different stages of clinical activity. Leukocytes were separated from 15 to 60 ml venous blood and were labeled in vitro with [99mTc]HM-PAO. The segmental extent (small intestine; ascending, transverse, and descending colon; and recto-sigmoideum) of the process was determined by LS. The uptake of each bowel segment was scored in relation to the bone marrow uptake. The scintigraphic activity, calculated by summing the segment scores, was compared with laboratory parameters. The mean labeling efficacy was 76% (60-86%). The segmental extent of the process determined by LS was compared with the results of barium enema or colonoscopy with regard to 32 bowel segments. The sensitivity, specificity, and accuracy of LS were 93, 88, and 91%, respectively. Two extraintestinal manifestations (abdominal abscess and joint involvement) were also detected by LS. These lesions were verified by computed tomography (CT) (abscess) and on the basis of the clinical outcome (arthritis). The scintigraphic activity correlated with the C-reactive protein (CRP) level (r = 0.82, p < 0.001), the alpha 2-globulin level (r = 0.63, p < 0.02), the sedimentation rate (r = 0.51, p < 0.05), and the fS iron level (r = -0.66, p < 0.005). LS is applicable in pediatric patients. The method is an excellent technique for assessment of the extent of IBD in children. Extraintestinal manifestations of IBD can also be investigated by LS. The scintigraphic activity is a useful parameter for determination of the activity of IBD in children.