An in vitro study to compare ~(99m)Xc-stannous colloids and ~(99m)Xc-HMPAO for labelling human leukocytes

摘要

Aim. Aim of the present study was to compare in vitro the labelling efficiency (LE) and cell viability (TBE) of autol-ogous leukocytes labelled with ~(99m)Tc-SnF_2 and ~(99m)Tc-HMPAO, and to evaluate the quantity and quality of spontaneously released ~(99m)Tc (SR) from labelled cells at several time poults after labelling. Methods. A total of 14 patients with different diseases and 18 normal subjects were included in this study. A blood sample was collected from each patient; purified autol-ogous leukocytes were divided into 2 samples and labelled with ~(99m)Tc-SnF_2 and ~(99m)Tc-HMPAO. LE was evaluated at the end of labelling and TBE and SR were evaluated at 10 min and 1 h, 2 h and 4 h after labelling. Results. LE of ~(99m)Tc-SnF_2-WBC was higher than ~(99m)Tc-HMPAO-WBC (6l.2±18.7% and 43.3±11.3; p < 0.0001) and we found an inverse correlation between blood glucose and labelling efficiency for both methods (p=0.02). Minimal differences were also observed between 2 methods after 10 min and 1 h, as far as the cell viability is concerned. The percentage of radioactivity spontaneously released from ~(99m)Tc-SnF_2-WBC was significantly higher compared to ~(99m)Tc-HMPAO-WBC at each time point Radioactivity released from labelled cells was predominantly ~(99m)Tc-SnF_2 and ~(99m)Tc-HMPAO with few free Conclusion. Both radiopharmaceuticals are not toxic for WBC. Labelling with ~(99m)Tc-SnF_2 give a higher LE than with ~(99m)Tc-HMPAO; however, radiolabelled colloids are more released from labelled cells over a period of 4 h. While ~(99m)Tc-HMPAO is physiological excreted into gastrointestinal tract, ~(99m)Tc-SnF_2 can be re-uptaken in vivo by reticulo-endothelial cells of liver and spleen. These findings suggest that ~(99m)Tc-SnF_2-WBC might be better than ~(99m)Tc-HMPAO-WBC for studying inflammatory bowel diseases.