Assessment of inflammatory bowel disease with two different 99mTc-leucocytes labelling methods

Aim of this study was to retrospectively compare the diagnostic accuracy of 99mTc-HMPAO white blood cell scintigraphy using two different cell suspension mediums: leukocyte poor plasma (LPP) and Hanks' Balanced Salt Solution (HBSS) in patients with suspicion of active inflammatory bowel disease. Materials and Methods: Leukocytes from 30 patients were labelled using LPP and in 28 using HBSS . In LPP method the leukocytes were resuspended in 0,5 ml cell-free plasma while in HBSS method the cells were resuspended in 0,5 ml HBSS. Scintigraphic images were obtained at 30 min and 2 h after injection of 185-200 MBq 99mTc-HMPAO leukocytes. Results: Leukocytes labelling efficiency were 65,5%, and 89,0%, respectively for LPP and HBSS methods. There were 22 true-positive, 7 true-negative and 1 false-negative results in the LPP group, while in the HBSS group results were 18, 10 and 0, respectively. Diagnostic accuracy was similar with both methods though sensitivity was slightly higher in the HBSS group. Conclusion These date indicate that leukocytes scintigraphy labelled using HBSS as resuspension medium should be used as first option method for WBC labelling and diagnosis of inflammatory bowel disease