Assessment of inflammatory bowel disease by using two different (99m)Tc leucocyte labelling methods

The aim of this study was to retrospectively compare the diagnostic accuracy of (99m)Tc hexamethylpropyleneamine oxime (HMPAO) white blood cell scintigraphy in patients with a suspicion of active inflammatory bowel disease by using two different cell suspension media: leukocyte poor plasma (LPP) and Hanks' balanced salt solution (HBSS). Leukocytes from 30 patients were labelled using LPP and in 28 cases using HBSS. In the LPP method the leukocytes were resuspended in 0.5 ml cell-free plasma while in the 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 (99m)Tc-HMPAO leukocytes. The leukocyte labelling efficiency was 65.5% and 89.0%, respectively, for the LPP and HBSS methods. There were 22 true positive, seven true negative and one false negative result in the LPP group, while in the HBSS group results were 18, nine and one, respectively. Diagnostic accuracy was similar with both methods although sensitivity was slightly higher in the HBSS group. In summary, these date indicate that leukocyte scintigraphy labelling using HBSS as the resuspension medium should be used as a first option for white blood cell labelling and diagnosis of inflammatory bowel disease.