Mobilization kinetics of CD34(+) cells in association with modulation of CD44 and CD31 expression during continuous intravenous administration of G-CSF in normal donors.
The aim of the present study is to evaluate the kinetics of CD34(+) cells and investigate the potential modulation of CD44 and CD31 expression on CD34(+) cells during continuous i.v. administration of G-CSF, thus to elucidate the possible mechanism of peripheral blood progenitor cell (PBPC) mobilization. Fifteen healthy donors were enrolled in this study. G-CSF (10 microg/kg/day) was administered for four consecutive days through continuous 24-h i.v. infusion. For measurement of complete blood counts, CD34(+) cell levels and their expression of CD44 and CD31, PB sampling was performed immediately before the administration of G-CSF (steady-state) and after 4, 8, 24, 48, 72, 96, and 120 h of G-CSF administration. The percentage and absolute number of CD34(+) cells significantly increased at day 3 (0. 55 +/- 0.09%, 51.12 +/- 24.83 x 10(3)/ml) and day 4 (0.47 +/- 0.09%, 46.66 +/- 24.93 x 10(3)/ml), compared to the steady-state level (0. 06 +/- 0.09%, 2.03 +/- 5.69 x 10(3)/ml). At day 3 to day 5 following the onset of G-CSF administration, a strong decrease of CD44 and CD31 expression was observed on mobilized CD34(+) cells compared to controls: the relative fluorescence intensity of CD44 and CD31 was, respectively, 50%-70% and 40%-90% lower than that of controls. We conclude that continuous i.v. administration of G-CSF apparently results in more rapid mobilization of CD34(+) cells, and downregulation of CD44 and CD31 on CD34(+) cells is likely to be involved in the mobilization of PBPC after treatment with G-CSF.
Lee
S
S
Departments of Hematology-Oncology, College of Medicine, Ewha Woman's University, Seoul, Korea.
Im
S A
SA
Yoo
E S
ES
Nam
E M
EM
Lee
M A
MA
Ahn
J Y
JY
Huh
J W
JW
Kim
D Y
DY
Lee
S N
SN
Kim
M J
MJ
Lee
S J
SJ
Chung
W S
WS
Seong
C M
CM
D000328:Adult; D018952:Antigens, CD34; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis*; D007275:Injections, Intravenous; D007700:Kinetics; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis*
D018952:Antigens, CD34; D018960:Hyaluronan Receptors; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D016179:Granulocyte Colony-Stimulating Factor