title: Use of granulocyte colony-stimulating factor for fluorine-18-fluorodeoxyglucose labeling in human leukocytes.
abstract: OBJECTIVE
  Insufficient labeling efficiency and poor retention of radioactivity are the considerable shortcomings of fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) labeling in human leukocytes. This study was conducted to evaluate the feasibility of using granulocyte colony-stimulating factor (G-CSF) to improve ¹⁸F-FDG labeling in human leukocytes.
  
  
  METHODS
  Leukocyte separation was performed using methods reported earlier. Separated leukocytes were preincubated with G-CSF or insulin at 37°C for 1 h. After preincubation, labeling was performed with ¹⁸F-FDG (37-74 MBq) at 37°C for 30 min. Retained radioactivity was assessed at 1-4 h after labeling by the same method described in earlier reports. The viability of labeled leukocytes was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay.
  
  
  RESULTS
  Labeling efficiency of leukocytes preincubated with G-CSF, G-CSF with insulin, insulin, and control leukocytes was 52.1±8.9%, 49.9±10.5%, 40.3±7.7%, and 40.3±6.0%, respectively. G-CSF significantly increased the labeling efficiency compared with insulin (P=0.005) and control (P=0.004). In leukocytes preincubated with G-CSF, 77.0±1.2%, and 59.0±1.8% of radioactivity was retained at 1 and 3 h after labeling. There was no significant difference in retained radioactivity compared with that of leukocytes with different treatment at all time points. Furthermore, no significant difference in viabilities among leukocytes with different treatments was observed.
  
  
  CONCLUSIONS
  Use of G-CSF significantly improved ¹⁸F-FDG labeling efficiency without a significant effect on cell viability and retention of radioactivity.
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Moon
authors.forename: Ho-Young
authors.initials: HY
authors.lastname: Lee
authors.forename: Jae Seon
authors.initials: JS
authors.lastname: Eo
authors.forename: Seog Gyun
authors.initials: SG
authors.lastname: Kim
authors.forename: Hye-Kyung
authors.initials: HK
authors.lastname: Shim
authors.forename: Hyun Woo
authors.initials: HW
authors.lastname: Kwon
authors.forename: Chulhan
authors.initials: C
authors.lastname: Kim
authors.forename: Yong-Il
authors.initials: YI
authors.lastname: Kim
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
authors.forename: June-Key
authors.initials: JK
authors.lastname: Chung
authors.forename: Myung Chul
authors.initials: MC
authors.lastname: Lee
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D007962:Leukocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D000925:Anticoagulants; D006895:Hydroxyethyl Starch Derivatives; D007328:Insulin; D019788:Fluorodeoxyglucose F18; D016179:Granulocyte Colony-Stimulating Factor