18F-FDG labelling of human leukocytes

Abstract

Radiolabelled leukocytes are useful for the imaging of inflammation and infection, and 18F-fluorodeoxyglucose (18F-FDG) is known to concentrate in metabolically active cells. We evaluated the feasibility of leukocyte labelling with 18F-FDG using ACD and heparin anticoagulants at 20 degrees C and 37 degrees C, with and without gentle mixing during incubation. With leukocytes (WBC) harvested from 20 ml blood, studies were performed using 18F-FDG in concentrations of 3.7-74 MBq (0.1-2.0 mCi). 18F-FDG WBC stability in platelet-poor plasma was assessed at 1-4 h. Satisfactory labelling efficiency was achieved with incubation in heparin-saline at 37 degrees C for 30 min (62.7+/-1.6%), and was further enhanced by mixing during incubation (78.1+/-3.9%). Cell labelling was predominantly of granulocytes (78.5+/-1.4%). 18F-FDG WBC was relatively stable in platelet-poor plasma for up to 4 h, and no cell staining was observed in viability studies using trypan blue. These results indicate the feasibility of leukocyte labelling with 18F-FDG, providing an approach that may be useful in PET imaging of inflammation and infection.

Quantification of the chromosomal radiation damage induced by labelling of leukocytes with [18F]FDG

“…The variability in published data could be related to methodological aspects such as number and type of cells [6,34], volume and geometry of samples and, of course, the CBMN assay [35,26]. In this sense, our CBMN test follows protocols compiled elsewhere [30] our mean labelling efficiencies (44-63% for [99mTc]HMPAO and 33-86% for [18F]FDG) are in agreement with published data [18,20,21,24], cell viability averaged 95%, as described in literature [9,25] and radiolabelling with 99mTc and 18F decreases in percentages similar to those of earlier publications [18,25].…”

“…Samples of fresh venous blood (35 ml) were extracted from 5 healthy donors (3 men 2 women, aged from 26 to 67 years old) and collected in 5 ml of saline with 350 UI of heparin (Heparin 5%, Hospira, Lake Forest, Illinois, USA) [24]. For each donor, additional 8 ml of blood was collected in saline-heparin and centrifuged at 1500g for 15 minutes to obtain cell-free plasma.…”

Usefulness of Positron Emission Tomography in the Evaluation of Distribution and Activity of Systemic Lesions Associated with Autoimmune Pancreatitis

“…The advantage of PET is to be able to quantify intracellular intake of 18 F-FDG by SUV. In human tissues a high level of 18 F-FDG uptake is not only recognized in tumor cells [7] , but also in endothelial cells [35] and leukocytes, especially granulocytes [36] and macrophages [37] . FDG uptake is affected by cellular conditions such as plasma membrane glucose transporter, GLUT-1 [38] and GLUT-4 [39] and glucose metabolic enzyme, hexokinase [38] and environmental conditions such as nitric oxide stimulants [38] and hypoxia [40] .…”

PET/CT with 18F-FDG–Labeled Autologous Leukocytes for the Diagnosis of Infected Fluid Collections in Acute Pancreatitis

“…However, image quality and resolution obtained with these tracers were unsatisfactory, especially for planar scintigraphy. Osman and Danpure (11) first described the in vitro labeling of leukocytes with 18 F-FDG, and several groups subsequently used this tracer to detect different types of infection in both animals and humans (12)(13)(14)(15). In the present study, the image quality provided by PET/CT with 18 F-FDG-labeled leukocytes was clearly superior to that previously reported with 99m Tc-or 111 In-labeled leukocytes.…”

“…The feasibility of labeling leukocytes in vitro with 18 F-FDG was first demonstrated by Osman and Danpure (11) and subsequently verified in both animals and humans by other groups (12,13). Rini et al directly compared leukocytes labeled with 111 In and leukocytes labeled with 18 F-FDG in orthopedic infections and described similar sensitivities, specificities, and accuracies with both tracers (14).…”