The in-vivo pharmacokinetics study of 99Tcm labelled anti-granulocyte monoclonal antibody BW250/183 and bone marrow radioimmunoimaging

Objective: To study 1) the biological distribution pattern of 99Tcm-BW250/183 after injection. 2) the primary clinical application of bone marrow radioimmunoimaging. Methods: 1) BW250/183 was labelled following sterile procedure, the labelling rate was analyzed by paper chromatography after being incubated with human serum at 37 degree C for 15 and 30 min, 1, 2, 4, 6 and 24 h. 2) One volunteer underwent whole body imaging 15 min, 1, 2, 4, 6 and 24 h after injection of 555 MBq 99Tcm-BW250/183, and 2 mL of blood samples was taken from a cubital vein at every time point. The percentage of radioactivity of different organs and the kinetic data of in-vivo 99Tcm-BW250/183 was then calculated. In all the blood samples the peripheral leukocytes were counted by a standard procedure. 3) Five control patients underwent whole body and regional imaging 4 h after injection of 555 MBq 99Tcm-BW250/183, the percentage of radioactivity of different organs and the uptake ratios of organ-to-background were calculated. Results: The in-vivo pharmacokinetics of 99Tcm-BW250/183 belonged to first-order reaction, two compartment model. T1/2α and T1/2β was 0.163 h and 13.066 h, respectively. After injection, the distribution of in-vivo 99Tcm-BW250/183 was mainly in bone marrow, and the peripheral leukocyte count maintained stable and showed no significant decrease. Conclusion: 99Tcm-BW250/183 is a safe and ideal bone marrow imaging agent