The use of 2-[18F]fluoro-2-deoxy-d-glucose as a potential in vitro agent for labelling human granulocytes for clinical studies by positron emission tomography

In this study, 2-[¹⁸F]fluoro-2-deoxy-d-glucose, ([¹⁸F]FDG) was used to radiolabel human granulocytes in vitro for possible clinical use by positron emission tomography (PET). Uptake of [¹⁸F]FDG was dependent on the amount of glucose in the labelling medium, e.g. when 1 × 10⁷ granulocytes were incubated with [¹⁸F]FDG containing 15μg/mL glucose 80% of [¹⁸F]FDG was incorporated within 30 min, but in the presence of 1 mg/mL of glucose it was reduced to 2%. Increasing the cell concentration and activating the granulocytes with Streptococcus pneumoniae, opsonized zymosan or phorbol myristate acetate all increased the uptake of [¹⁸F]FDG. Retention of the [¹⁸F]FDG by the cells as [¹⁸F]FDG-6-phosphate was also dependent on the extracellular glucose concentration, 9% was released within 60 min in the absence of glucose, but 27% in the presence of 1 mg/mL glucose.