No abstract available.
Neoplasm, Residual*

BACKGROUND: Peripheral blood progenitor cells collected from normal donors after granulocyte- colony stimulating factor (G-CSF) treatment are increasingly used for allogeneic transplantation. Previously, we investigated the mobilization kinetics of CD34+/Thy-1dim progenitor cells during subcutaneous administration of G-CSF in normal donors (Transfusion 1997;37:406-10). Although it is considered to be a relatively safe procedure, there are still uncertainties about the most efficient method of progenitor cell mobilization. Due to the short elimination half-life of G-CSF of about 3-4 hours we considered the subcutaneous administration of G-CSF once or twice daily might be suboptimal. The aim of the present study is to evaluate the mobilization kinetics of CD34+ cells during continuous intravenous (IV) administration of G-CSF in normal donors. METHODS: Fifteen healthy donors were enrolled in this study. The median age was 38 years (range, 20-56). G-CSF (Filgrastim, 10 microgram/kg/day) was administered for 4 consecutive days through continuous IV infusion. Then, we collected PBPC on the day following the 4th dose of G-CSF using a blood cell separator. For measurement of complete blood counts and CD34+ cell levels, peripheral blood sampling was performed immediately before the administration of G-CSF (steady-state) and after 4, 8, 24, 48, 72, 96, 120 hours of continuous IV administration of G-CSF. RESLUTS: After continuous IV administration of G-CSF, the WBC counts increased up to day 5 and reached approximately 8.4-fold above the steady-state level. Changes in the granulocyte count were similar to those in WBC counts. The number of lymphocytes increased up to day 4 (2.7-fold above the steady-state level), but no further increase occurred on day 5. Although there were considerable variations among the healthy donors, the statistical peaks of CD34+ cell levels were consistently observed on day 3 or day 4. Up to the fourth day of G-CSF treatment, the circulating CD34+ cells expanded by 25-fold. The percentage and absolute number of CD34+ cells significantly increased on day 3 (0.55 +/- 0.09%, 51.12 +/- 24.83x103/mL) and day 4 (0.47 +/- 0.09%, 46.66 +/- 24.93x103/mL), compared with steady-state values (0.06 +/- 0.09%, 2.03 +/- 5.69x103/mL). CONCLUSION: Our results showed that continuous IV administration of G-CSF apparently results in more rapid mobilization of CD34+ cells at least 24-48 hours compared with daily subcutaneous administration of G-CSF in normal donors.
Administration, Intravenous* ; Blood Cell Count ; Blood Cells ; Colony-Stimulating Factors ; Granulocyte Colony-Stimulating Factor* ; Granulocytes ; Half-Life ; Humans ; Kinetics* ; Lymphocytes ; Stem Cells ; Tissue Donors* ; Transplantation, Homologous

No abstract available.
Stem Cells*

BACKGROUND: The stromal cells, which one part of the microenvironment, including adipocyte, fibroblasts, endothelial cells, macrophage and smooth muscle cells provide a suitable environment for self-renewal, proliferation and differentiation of hematopoietic stem cells, as well as providing other regulators, cytokines to stimulate and enhance hematopoiesis. Unlike bone marrow, the in vitro development of this stroma cells from the umbilical cord blood (UCB) is not well established and has met very limited success. To see if stromal elements capable of supporting hematopoiesis could be grown from CD34+ enriched umbilical cord blood, we was done stroma-free liquid culture system with thrombopoietin (TPO), flt3-ligand (FL) and the granulocyte- colony stimulating factor (G-CSF) using cord blood CB CD34+ cells. METHODS: Purified umbilical cord blood CD34+ cells were cultured for five weeks in a stroma-free liquid culture system using TPO, FL, and G-CSF in the density of 1x105 cells/mL. When a firmly adherent monolayer of fibroblast like cells were fully formed, we evaluate morphology, immunopheno-type, immunohistochemistry and functional assay, including non-adherent expansion, clonogenic progenitor expansion and apoptosis of established adherent cell layers. RESULTS: By the 4th~5th week, we found that firmly adherent fibroblast-like cells were established. These cells showed characteristics of endothelial cells expressing with VWF, VCAM-1, ICAM-1, CD31 and E-selectin. Furthermore, comparing without established endothelial monolayer, with established endothelial monolayer better expansion of total nucleated cells, CD34+ cells and colony forming units granulocyte-macrophage (CFU-GM) during culture were found. CONCLUSION: These results suggest that the UCB CD34+ cell fraction contains stromal cell precursors and can establish the hematopoietic microenvironment to expand and sustain UCB CD34+ cells through down-regulating apoptosis.
Adipocytes ; Apoptosis ; Bone Marrow ; Colony-Stimulating Factors ; Cytokines ; E-Selectin ; Endothelial Cells ; Fetal Blood* ; Fibroblasts ; Granulocyte Colony-Stimulating Factor* ; Hematopoiesis ; Hematopoietic Stem Cells ; Humans* ; Immunohistochemistry ; Intercellular Adhesion Molecule-1 ; Macrophages ; Myocytes, Smooth Muscle ; Stem Cells ; Stromal Cells ; Thrombopoietin ; Vascular Cell Adhesion Molecule-1

BACKGROUND: The aim of the present study is to evaluate the modulation of CD44 and CD31 expression and apoptotic status on mobilized CD34+ cells during continuous intravenous (i.v.) administration of granulocyte-colony stimulating factor (G-CSF), elucidating the mechanism of peripheral blood progenitor cells (PBPC) mobilization in normal donors. METHODS: Fifteen healthy donors were enrolled in this study. G-CSF (10 microgram/kg/day) was administered for 4 consecutive days through continuous i.v. infusion. Measurement of CD34+ cell levels and their expression of CD44, CD31 and 7-aminoactinomycin D (7-AAD) was performed. PB sampling was drawn immediately before the administration of G-CSF (steady-state) and after 4, 8, 24, 48, 72, 96 and 120 hours of G- CSF administration. RESULTS: Although there were considerable variations among the healthy donors, the absolute number of CD34+ cells significantly increased at day 3 (51.12+/-24.83x103/mL) and day 4 (46.66+/-24.93x103/mL),compared to the steady-state level (2.03+/-5.69x103/mL). The expression of CD44 on CD34+ cells revealed a significant reduction from the steady-state level (579.59+/-133.69) after day 3 (281.02+/-105.15, P=0.0059) and day 4 (164.76+/-107.44, P=0.0002) of G-CSF administration. The expression of CD31 on CD34+ cells also significantly decreased from the steady-state level (145.86+/-30.52) after day 4 (34.47+/-38.87, P=0.0055) and day 5 (17.33+/-50.68, P=0.0134) of G-CSF administration. The proportions of apoptotic (7-AADdIm) CD34+ cells were also significantly decreased after day 3 of G-CSF administration. CONCLUSION: Down-regulation of CD44 and CD31 on CD34+ cells is likely to be involved in the mobilization of PBPC and G- CSF may acts as a survival factor for mobilized CD34+ cells by the suppression of apoptosis during continuous i.v. administration of G-CSF in normal donors.
Administration, Intravenous* ; Apoptosis ; Down-Regulation ; Granulocyte Colony-Stimulating Factor ; Humans ; Stem Cells ; Tissue Donors*

Emergence of new clonal chromosomal abnormality (CCA) has been reported in Philadelphia-negative cells in patients with chronic myeloid leukemia (CML) undergoing the tyrosine kinase inhibitor (TKI) treatment. However, the time of emergence and clinical significance of CCA remains to be elucidated. In this study, we report a CML patient undergoing TKI treatment who developed myelodysplastic syndrome (MDS) after 206 months since the diagnosis of CML. Results of droplet digital PCR performed with serial bone marrow samples revealed that monosomy 7 in Philadelphia-negative cells appeared at the time of MDS development that did not exist initially at the time of CML diagnosis.

Emergence of new clonal chromosomal abnormality (CCA) has been reported in Philadelphia-negative cells in patients with chronic myeloid leukemia (CML) undergoing the tyrosine kinase inhibitor (TKI) treatment. However, the time of emergence and clinical significance of CCA remains to be elucidated. In this study, we report a CML patient undergoing TKI treatment who developed myelodysplastic syndrome (MDS) after 206 months since the diagnosis of CML. Results of droplet digital PCR performed with serial bone marrow samples revealed that monosomy 7 in Philadelphia-negative cells appeared at the time of MDS development that did not exist initially at the time of CML diagnosis.

Leukotriene B4(LTB4), derived from arachidonic acid, is a potent chemotactic agent and activating factor for hematopoietic cells. In addition to host defense in vivo, several eicosanoids have been reported to be involved in stem cell differentiation or proliferation. In this study, we investigated the effect of LTB4 on human cord blood CD34+ hematopoietic stem cells (HSCs). LTB4 was shown to induce proliferation of HSC and exert anti-apoptotic effect on the stem cells. Blockade of interaction between LTB4 and its receptor enhanced self-renewal of the stem cells. Effect of LTB4 on differentiation of CD34+ HSCs were confirmed by clonogenic assays, and induction of the expression of BLT2 (the low- affinity LTB4 receptor), during the ex vivo expansion was confirmed by reverse transcription-PCR. Our results suggest that LTB4-BLT2 interaction is involved in the cytokine-induced differentiation and ex vivo expansion of hematopoietic stem cells.
Antigens, CD34/metabolism ; Apoptosis/drug effects ; Cell Differentiation/drug effects ; Cell Proliferation/drug effects ; Fetal Blood/cytology/drug effects ; Hematopoietic Stem Cells/*drug effects/metabolism ; Humans ; Leukotriene B4/*pharmacology ; Receptors, Leukotriene B4/genetics/metabolism ; Research Support, Non-U.S. Gov't ; Reverse Transcriptase Polymerase Chain Reaction ; *Signal Transduction

Prognosis is known to be better in cases with isolated chromosomal abnormalities than in those with complex karyotypes. Accordingly, del(20q) as an isolated abnormality must be distinguished from cases in which it is associated with other chromosomal rearrangements for a better stratification of prognosis. We report a case of an isolated del(20q) abnormality with additional genomic aberrations identified using whole-genome single nucleotide polymorphism array (SNP-A)-based karyotyping. A 39-yr-old man was diagnosed with AML without maturation. Metaphase cytogenetic analysis (MC) revealed del(20)(q11.2) as the isolated abnormality in 100% of metaphase cells analyzed, and FISH analysis using D20S108 confirmed the 20q deletion in 99% of interphase cells. Using FISH, other rearrangements such as BCR/ABL1, RUNX1/RUNX1T1, PML/RARA, CBFB/MYH11, and MLL were found to be negative. SNP-A identified an additional copy neutral loss of heterozygosity (CN-LOH) in the 11q13.1-q25 region. Furthermore, SNP-A allowed for a more precise definition of the breakpoints of the 20q deletion (20q11.22-q13.31). Unexpectedly, the terminal regions showed gain on chromosome 20q. The patient did not achieve complete remission; 8 months later, he died from complications of leukemic cell infiltrations into the central nervous system. This study suggests that a presumably isolated chromosomal abnormality by MC may have additional genomic aberrations, including CN-LOH, which could be associated with a poor prognosis. SNP-A-based karyotyping may be helpful for distinguishing true isolated cases from cases in combination with additional genomic aberrations not detected by MC.

Cases of clonal cytogenetic abnormalities in Philadelphia-negative cells during the treatment of Philadelphia-positive CML have been previously reported. However, clonal abnormalities unrelated to the original t(8;21) or t(15;17) karyotype are not common. Deletion of 20q (del(20q)) is one of the most common recurrent cytogenetic abnormalities in myeloid neoplasms. Here we describe 3 patients with t(8;21), t(15;17), or t(9;22) who developed unrelated del(20q) after successful treatment of leukemia. We retrospectively reviewed the cytogenetic results of 23 AML patients with t(8;21)(q22;q22), 28 AML patients with t(15;17)(q22;q12), and 47 CML patients with t(9;22)(q34;q11.2). We identified 3 patients with del(20q) as the only clonal aberration unrelated to the primary karyotype when they achieved complete morphologic and cytogenetic remission. The latency period between diagnosis and emergence of del(20q) was 1, 114, and 35 months for the 3 patients, respectively. There was no evidence of therapy-related MDS/AML during the follow-up period. In 1 AML patient with t(8;21), relapse occurred in a t(8;21)(q22;q22) clone and the del(20q) clones were lost. The clinical significance of del(20q) as an unrelated clonal aberration is unknown, but our study suggests that del(20q) does not cause therapy-related MDS/AML or indicate disease progression.
Chromosome Aberrations ; Chromosome Deletion ; Chromosomes, Human, Pair 20 ; Clone Cells ; Cytogenetics ; Disease Progression ; Follow-Up Studies ; Humans ; Karyotype ; Latency Period (Psychology) ; Leukemia ; Recurrence ; Retrospective Studies