Inflammatory bowel disease activity assessment with biologic markers and 99mTc-WBC scintigraphy: are there different trends in ileitis versus colitis?

To evaluate whether scintigraphy with (99m)Tc-labeled white blood cells (WBC) can assess the intensity of bowel inflammation, a large dataset of laboratory values and clinical activity indices was correlated with (99m)Tc-WBC scintigraphy in children with Crohn's disease (CD), ulcerative colitis (UC), and miscellaneous colitis (MC). Also evaluated was whether stratification of children with CD as ileitis versus colitis results in different correlation coefficients for laboratory values versus (99m)Tc-WBC scintigraphy.

METHODS

Over a 6-y period, 313 (99m)Tc-WBC studies were performed. A dataset of 2,714 laboratory values is available for analysis.

RESULTS

There is a positive correlation between the erythrocyte sedimentation rate (ESR) and large bowel uptake of (99m)Tc-WBC (P < 0.05) and a negative trend with small bowel uptake of (99m)Tc-WBC in children with CD. Similarly, there is a correlation between WBC counts and scintigraphy in most segments of the large bowel and a negative correlation with the small bowel (R = -0.32, P = 0.01) in children with CD. There is a correlation between platelets and (99m)Tc-WBC in children with CD or UC. There is no correlation between the ESR and (99m)Tc-WBC in children with UC or MC. Many clinical activity indices correlate (P < 0.001) with (99m)Tc-WBC in children with CD, but none correlates in children with UC. Numerous laboratory values correlate with each other. There is a negative correlation between protein, albumin, hemoglobin, and hematocrit versus (99m)Tc-WBC scintigraphy in children with CD. In children with UC, there is a negative correlation between hemoglobin and hematocrit versus (99m)Tc-WBC.

CONCLUSIONS

(99m)Tc-WBC scintigraphy, ESR, and WBC counts are good indicators of the inflammatory activity in CD if the inflammation is limited to the large bowel. There is a trend toward an inverse relationship when the inflammation is limited to the small bowel; thus, scintigraphy and the aforementioned markers may be of limited value. This report also demonstrates that (99m)Tc-WBC scintigraphy correlates with clinical activity indices in CD and with numerous biologic markers. In children with UC, scintigraphy with (99m)Tc-WBC and most laboratory markers are of limited value in assessing disease activity.