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Kraal KCJM, Timmerman I, Kansen HM, van den Bos C, Zsiros J, van den Berg H, Somers S, Braakman E, Peek AML, van Noesel MM, van der Schoot CE, Fiocco M, Caron HN, Voermans C, Tytgat GAM. Peripheral Stem Cell Apheresis is Feasible Post 131Iodine-Metaiodobenzylguanidine-Therapy in High-Risk Neuroblastoma, but Results in Delayed Platelet Reconstitution. Clin Cancer Res 2018; 25:1012-1021. [PMID: 30314967 DOI: 10.1158/1078-0432.ccr-18-1904] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/01/2018] [Accepted: 10/09/2018] [Indexed: 11/16/2022]
Abstract
PURPOSE Targeted radiotherapy with 131iodine-meta-iodobenzylguanidine (131I-MIBG) is effective for neuroblastoma (NBL), although optimal scheduling during high-risk (HR) treatment is being investigated. We aimed to evaluate the feasibility of stem cell apheresis and study hematologic reconstitution after autologous stem cell transplantation (ASCT) in patients with HR-NBL treated with upfront 131I-MIBG-therapy. EXPERIMENTAL DESIGN In two prospective multicenter cohort studies, newly diagnosed patients with HR-NBL were treated with two courses of 131I-MIBG-therapy, followed by an HR-induction protocol. Hematopoietic stem and progenitor cell (e.g., CD34+ cell) harvest yield, required number of apheresis sessions, and time to neutrophil (>0.5 × 109/L) and platelet (>20 × 109/L) reconstitution after ASCT were analyzed and compared with "chemotherapy-only"-treated patients. Moreover, harvested CD34+ cells were functionally (viability and clonogenic capacity) and phenotypically (CD33, CD41, and CD62L) tested before cryopreservation (n = 44) and/or after thawing (n = 19). RESULTS Thirty-eight patients (47%) were treated with 131I-MIBG-therapy, 43 (53%) only with chemotherapy. Median cumulative 131I-MIBG dose/kg was 0.81 GBq (22.1 mCi). Median CD34+ cell harvest yield and apheresis days were comparable in both groups. Post ASCT, neutrophil recovery was similar (11 days vs. 10 days), whereas platelet recovery was delayed in 131I-MIBG- compared with chemotherapy-only-treated patients (29 days vs. 15 days, P = 0.037). Testing of harvested CD34+ cells revealed a reduced post-thaw viability in the 131I-MIBG-group. Moreover, the viable CD34+ population contained fewer cells expressing CD62L (L-selectin), a marker associated with rapid platelet recovery. CONCLUSIONS Harvesting of CD34+ cells is feasible after 131I-MIBG. Platelet recovery after ASCT was delayed in 131I-MIBG-treated patients, possibly due to reinfusion of less viable and CD62L-expressing CD34+ cells, but without clinical complications. We provide evidence that peripheral stem cell apheresis is feasible after upfront 131I-MIBG-therapy in newly diagnosed patients with NBL. However, as the harvest of 131I-MIBG-treated patients contained lower viable CD34+ cell counts after thawing and platelet recovery after reinfusion was delayed, administration of 131I-MIBG after apheresis is preferred.
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Affiliation(s)
- Kathelijne C J M Kraal
- Princess Máxima Center for Pediatric Oncology (PMC), Utrecht, the Netherlands.,Department of Pediatric Oncology, Emma Children's Hospital (EKZ/AMC), Amsterdam, the Netherlands
| | - Ilse Timmerman
- Princess Máxima Center for Pediatric Oncology (PMC), Utrecht, the Netherlands.,Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, the Netherlands
| | - Hannah M Kansen
- Princess Máxima Center for Pediatric Oncology (PMC), Utrecht, the Netherlands.,Department of Paediatric Pulmonology and Allergology, University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Cor van den Bos
- Princess Máxima Center for Pediatric Oncology (PMC), Utrecht, the Netherlands.,Department of Pediatric Oncology, Emma Children's Hospital (EKZ/AMC), Amsterdam, the Netherlands
| | - Jozsef Zsiros
- Princess Máxima Center for Pediatric Oncology (PMC), Utrecht, the Netherlands.,Department of Pediatric Oncology, Emma Children's Hospital (EKZ/AMC), Amsterdam, the Netherlands
| | - Henk van den Berg
- Department of Pediatric Oncology, Emma Children's Hospital (EKZ/AMC), Amsterdam, the Netherlands
| | - Sebastiaan Somers
- Department of Pediatric Oncology, Emma Children's Hospital (EKZ/AMC), Amsterdam, the Netherlands
| | - Eric Braakman
- Department of Hematology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Annemarie M L Peek
- Department of Pediatric Oncology, University of Groningen, University Medical Centre Groningen, Groningen, the Netherlands
| | - Max M van Noesel
- Princess Máxima Center for Pediatric Oncology (PMC), Utrecht, the Netherlands
| | - C Ellen van der Schoot
- Department of Experimental Immunohematology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, the Netherlands
| | - Marta Fiocco
- Medical Statistics, Department of Biomedical Data Sciences, Leiden University Medical Center, Leiden, the Netherlands.,Mathematical Institute, Leiden University, Leiden, the Netherlands
| | - Huib N Caron
- Department of Pediatric Oncology, Emma Children's Hospital (EKZ/AMC), Amsterdam, the Netherlands
| | - Carlijn Voermans
- Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, the Netherlands
| | - Godelieve A M Tytgat
- Princess Máxima Center for Pediatric Oncology (PMC), Utrecht, the Netherlands. .,Department of Pediatric Oncology, Emma Children's Hospital (EKZ/AMC), Amsterdam, the Netherlands
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Pharmacological inhibition of caspase and calpain proteases: a novel strategy to enhance the homing responses of cord blood HSPCs during expansion. PLoS One 2012; 7:e29383. [PMID: 22235291 PMCID: PMC3250442 DOI: 10.1371/journal.pone.0029383] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 11/28/2011] [Indexed: 02/06/2023] Open
Abstract
Background Expansion of hematopoietic stem/progenitor cells (HSPCs) is a well-known strategy employed to facilitate the transplantation outcome. We have previously shown that the prevention of apoptosis by the inhibition of cysteine proteases, caspase and calpain played an important role in the expansion and engraftment of cord blood (CB) derived HSPCs. We hypothesize that these protease inhibitors might have maneuvered the adhesive and migratory properties of the cells rendering them to be retained in the bone marrow for sustained engraftment. The current study was aimed to investigate the mechanism of the homing responses of CB cells during expansion. Methodology/Principal Findings CB derived CD34+ cells were expanded using a combination of growth factors with and without Caspase inhibitor -zVADfmk or Calpain 1 inhibitor- zLLYfmk. The cells were analyzed for the expression of homing-related molecules. In vitro adhesive/migratory interactions and actin polymerization dynamics of HSPCs were assessed. In vivo homing assays were carried out in NOD/SCID mice to corroborate these observations. We observed that the presence of zVADfmk or zLLYfmk (inhibitors) caused the functional up regulation of CXCR4, integrins, and adhesion molecules, reflecting in a higher migration and adhesive interactions in vitro. The enhanced actin polymerization and the RhoGTPase protein expression complemented these observations. Furthermore, in vivo experiments showed a significantly enhanced homing to the bone marrow of NOD/SCID mice. Conclusion/Significance Our present study reveals another novel aspect of the regulation of caspase and calpain proteases in the biology of HSPCs. The priming of the homing responses of the inhibitor-cultured HSPCs compared to the cytokine-graft suggests that the modulation of these proteases may help in overcoming the major homing defects prevalent in the expansion cultures thereby facilitating the manipulation of cells for transplant procedures.
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Woo KS, Goh RY, Kim SH, Kwon HC, Kim HJ, Lee YH, Han JY. Number of megakaryocytic progenitors and adhesion molecule expression of stem cells predict platelet engraftment after allogeneic hematopoietic stem cell transplantation. Cytotherapy 2007; 9:555-61. [PMID: 17882720 DOI: 10.1080/14653240701561337] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND The mechanism of platelet recovery after hematopoietic stem cell transplantation and the factors that influence its time-course are not fully understood. Rapid hematopoietic recovery results in a reduction of transplantation-related complications. In the present study, we questioned and analyzed whether there were important factors predicting the speed of platelet engraftment. METHODS Thirty-seven patients with various hematologic diseases transplanted with allogeneic BM between January 2002 and December 2005 were included. We investigated the differences in mononuclear cell counts (MNC), numbers of infused CD34(+), CD34(+) CD41(+) and CD34(+) CD61(+) cells and phenotypic analysis of homing-associated cell adhesion molecules (CXCR4, CD49d and CD49e). The number of megakaryocytes formed in vitro (colony-forming unit-megakaryocytes; CFU-Mk) was also measured. RESULTS Median days of ANC >/=0.5x10(9)/L and platelet count >/=20x10(9)/L were 14.8 and 17.3, respectively. The number of infused CD34(+) CD41(+) and CD34(+) CD61(+) cells correlated much better with the time to platelet engraftment than that of infused CD34(+)cells (P<0.05 each). Rapid platelet recovery also occurred in patients receiving both higher homing-associated cell adhesion molecule doses and CFU-Mk (P<0.05 each). DISCUSSION Rapid platelet recovery has several advantages, including reducing the cost of supportive therapy and reducing the risk of fatal bleeding as a result of severe thrombocytopenia. Our findings suggest that phenotypic and clonogenic assessment of infused progenitor cells can identify patients in whom platelet engraftment is likely to be significantly delayed, and new strategies to overcome related problems might be employed in the very near future.
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Affiliation(s)
- K S Woo
- Department of Laboratory Medicine, Dong-A University College of Medicine, Busan, Korea
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Gold J, Valinski HM, Hanks AN, Ballen KK, Hsieh CC, Becker PS. Adhesion receptor expression by CD34+ cells from peripheral blood or bone marrow grafts: correlation with time to engraftment. Exp Hematol 2006; 34:680-7. [PMID: 16647574 DOI: 10.1016/j.exphem.2006.01.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Revised: 01/24/2006] [Accepted: 01/25/2006] [Indexed: 01/31/2023]
Abstract
OBJECTIVE This study was undertaken to define the pattern of cell adhesion receptor expression by the CD34+ progenitor cells from mobilized peripheral blood and bone marrow from normal and autologous donors, and to correlate the adhesion receptor profile with time to blood cell recovery for patients undergoing autologous transplant. METHODS Blood cell recovery was determined by absolute neutrophil count (> 500/microL), time to last red cell transfusion, and platelet count (> 50,000/microL and > 100,000/microL). The analysis for expression of adhesion receptors alphaL (CD11a), alpha2 (CD49b), alpha3 (CD49c), alpha4 (CD49d), alpha5 (CD49e), alpha6 (CD49f), beta1 (CD29), L-selectin (CD62L), ICAM-1 (CD54), PECAM-1 (CD31), HCAM (CD44), and P-selectin (CD62P) was performed by two-color flow cytometry. The Kruskal-Wallis test and Spearman's rank correlation were used for statistical analysis. RESULTS Statistical analysis of adhesion expression by the CD34+ population for patients undergoing autologous transplant demonstrated that the higher percent expression of PECAM-1 correlated with longer time to platelet recovery (> 100,000/microL, p = 0.049). In contrast, the higher the percent expression of alpha6 (p = 0.013) and the increased density of expression of alpha2 (p = 0.035), alpha3 (p = 0.023), alpha4 (p = 0.044), beta1 (p = 0.027), and ICAM-1 (p = 0.010) correlated with shorter time to platelet recovery. Neutrophil recovery time decreased with increased density of expression of alphaL (p = 0.014) and P-selectin (p = 0.007) receptors. Increased density of expression of CD44 (HCAM) was associated with longer time to red blood cell recovery (p = 0.05). CONCLUSION These data suggest that upregulation of specific adhesion receptors or selection of certain cell populations could result in earlier blood cell recovery after transplant.
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Affiliation(s)
- Jack Gold
- Department of Mathematics, University of Massachusetts, Amherst, MA, USA
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Greco NJ, Lee WR, Moroff G. Increased transmigration of G-CSF-mobilized peripheral blood CD34+ cells after overnight storage at 37°C. Transfusion 2003; 43:1575-86. [PMID: 14617318 DOI: 10.1046/j.1537-2995.2003.00572.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND G-CSF-mobilized PBPCs are utilized in allogeneic and autologous PBPC transplants. Homing, adhesion, and transmigration of hematopoietic CD34+ cells are required for successful engraftment. Hematopoietic CD34+ cells undergo directional migration toward the CXCR4 receptor ligand stromal-derived factor-1 (SDF-1). Limited data are available on the effects of liquid storage and cryopreservation on PBPC CD34+ cells. STUDY DESIGN AND METHODS Magnetic-assisted cell sorting (MACS)-selected CD34+ cells were assayed for retention of in vitro transmigration and phenotypic changes of unit-matched liquid-stored and cryopreserved PBPC samples from healthy donors. Studies evaluated whether transmigration of CD34+ cells in Iscove's modified Dulbecco's medium plus 1 percent HSA alone or in medium supplemented with SCF or allogeneic plasma was affected by overnight incubation at 37 degrees C, relative to nonincubated conditions. RESULTS Transmigration was maintained during liquid storage at 1 to 6 degrees C during a 2-day period and in unit-matched cryopreserved-thawed samples that had been initially liquid stored. Overnight incubation at 37 degrees C of MACS-selected unit-matched liquid-stored or cryopreserved-thawed CD34+ cells resulted in substantially increased transmigration, in particular with noncoated filters chemoattracted with the chemokine SDF-1. CONCLUSION CD34+ cell transmigration was comparable between liquid-stored and cryopreserved samples, and both demonstrated similar increases after overnight incubation at 37 degrees C.
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Affiliation(s)
- Nicholas J Greco
- American Red Cross, Blood & Cell Therapy Development Department, Holland Laboratory, Rockville, Maryland, USA.
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Netelenbos T, van den Born J, Kessler FL, Zweegman S, Huijgens PC, Drager AM. In vitro model for hematopoietic progenitor cell homing reveals endothelial heparan sulfate proteoglycans as direct adhesive ligands. J Leukoc Biol 2003; 74:1035-44. [PMID: 14525970 DOI: 10.1189/jlb.1202593] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Proteoglycans (PGs) play a dominant role within the bone marrow (BM), but their role in homing of transplanted hematopoietic progenitor cells (HPC) is unknown. In this study, the role of heparan sulfate (HS) PGs on BM endothelium as adhesive structures was investigated. HPC (primary CD34+ cells and cell line KG-1a) were able to bind fractionated heparin, which could be competed by highly sulfated heparin/HS-glycosaminoglycans (GAGs). Under flow conditions, HPC adhered to immobilized heparin after rolling over E-selectin. Rolling of KG-1a on BM endothelial cell (EC) line 4LHBMEC was completely E selectin-dependent. Addition of heparin/HS-GAGs, endothelial treatment with chlorate, or anti-HS all partially inhibited firm adhesion. Moreover, enzymatic removal of endothelial HS-GAGs reduced initial adhesion. Finally, HPC-bound PGs isolated from 4LHBMEC, which was largely inhibited by enzymatic HS-degradation. In summary, we identified sulfated structures on BM endothelium, most likely HSPGs, as a novel class of glycoconjugates involved in the multistep homing cascade of HPC.
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Affiliation(s)
- Tanja Netelenbos
- Department of Hematology, Vrije Universiteit Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
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Plett PA, Frankovitz SM, Orschell CM. Distribution of marrow repopulating cells between bone marrow and spleen early after transplantation. Blood 2003; 102:2285-91. [PMID: 12775569 DOI: 10.1182/blood-2002-12-3742] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Whether hematopoietic stem cells (HSCs) home selectively to bone marrow (BM) early after transplantation remains an issue of debate. Better understanding of homing mechanisms may benefit BM transplantation protocols in cases of limited graft cell number or nonmyeloablative conditioning regimens. Using flow cytometry and serial transplantation to stringently identify HSCs, trafficking patterns of long-term engrafting cells were mapped between BM and spleen early after transplantation. Low-density BM cells were tracked in irradiated or nonirradiated mice 1, 3, 6, and 20 hours after transplantation, at which time recipient BM and spleen were analyzed for recovery of primitive donor cells by phenotype and adhesion molecule expression. In addition, phenotypically defined HSC-enriched or HSC-depleted grafts were tracked 20 hours after transplantation in recipient BM and spleen and analyzed for recovery and long-term repopulating potential in mice undergoing serial transplantation. Regardless of irradiation status, recovery of donor Sca-1+ lin- cells was higher at most time points in recipient BM than in spleen, while recovery of total Sca-1+ cells was variable. A significantly higher percentage of BM-homed donor Sca-1+ cells expressed CD43, CD49e, and CD49d 20 hours after transplantation than spleen-homed cells, which contained significantly more non-HSC phenotypes. Furthermore, BM-homed cells were significantly enriched for cells capable of secondary multilineage hematopoiesis in mice undergoing serial transplantation compared with spleen-homed cells. These results support the notion of specific homing of HSCs to BM by 20 hours after transplantation and provide a basis for the enhanced engraftment potential afforded some Sca-1+ lin- cells subfractionated on the basis of adhesion molecule expression.
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Affiliation(s)
- P Artur Plett
- Department of Medicine, Indiana University School of Medicine, 1044 W Walnut Street, Indianapolis, IN 46202-5254, USA
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Fruehauf S, Topaly J, Schad M, Paschka P, Gschaidmeier H, Zeller WJ, Hochhaus A, Ho AD. Imatinib restores expression of CD62L in BCR-ABL-positive cells. J Leukoc Biol 2003; 73:600-3. [PMID: 12714574 DOI: 10.1189/jlb.1002507] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Chronic myelogenous leukemia (CML) is characterized by aberrant trafficking of malignant hematopoietic progenitor cells in the peripheral blood. Expression of the cell adhesion molecule CD62L was reported to be significantly lower in CML patients than in normal controls. We studied whether the transcription of CD62L in CML cells is dependent on the activity of the BCR-ABL tyrosine kinase. Following addition of the Abelson (ABL) tyrosine kinase inhibitor imatinib (formerly STI571) to two BCR-ABL-positive cell lines (BV173, SD-1), we observed a dose-dependent increase in CD62L RNA levels of up to 45-fold by a quantitative, real-time polymerase chain reaction and an increase in the amount of cell surface-bound CD62L of up to 18-fold by quantitative flow cytometry, respectively. These data are validated by an increased CD62L expression in the bone marrow of patients (n=6) with advanced CML who received imatinib. Restoration of defective cell adhesion mediated via the CD62L pathway may be one mechanism of action of imatinib in BCR-ABL-positive leukemias.
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MESH Headings
- Antineoplastic Agents/pharmacology
- Benzamides
- Biomarkers, Tumor/analysis
- Dose-Response Relationship, Drug
- Enzyme Inhibitors/pharmacology
- Fusion Proteins, bcr-abl/analysis
- Gene Expression Regulation, Leukemic/drug effects
- Humans
- Imatinib Mesylate
- L-Selectin/biosynthesis
- L-Selectin/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Piperazines/pharmacology
- Polymerase Chain Reaction
- Pyrimidines/pharmacology
- RNA, Messenger/biosynthesis
- RNA, Neoplasm/biosynthesis
- Tumor Cells, Cultured/drug effects
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Affiliation(s)
- S Fruehauf
- Department of Internal Medicine V, University of Heidelberg, Germany.
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Greco NJ, Lee WR, Kurtz J, Seetharaman S, Moroff G. Characterization of multiple CD34+ cell populations in cord blood. JOURNAL OF HEMATOTHERAPY & STEM CELL RESEARCH 2003; 12:199-213. [PMID: 12804179 DOI: 10.1089/152581603321628340] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Unlike granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood, which show a single homogeneous population of CD34(+) cells, umbilical cord blood (CB) CD34(+) cells are present as multiple populations, CD34(regular) and CD34(bright) (the latter comprising 7.0-58.2% of the total CD34(+) cells), using the ProCOUNT trade mark procedure or with anti-CD34 labeling of immunoselected cells. The CD34(regular) population contains cells with high forward scatter (CD34(regular)FSC(high)) and with low forward scatter (CD34(regular) FSC(low)). Immunomagnetically selected CD34(+) cells, sorted into CD34(regular), CD34(regular) FSC(high), CD34(regular)FSC(low), and CD34(bright) cell populations, were used in in vitro assays: only the CD34(regular)FSC(high) population transmigrated and showed growth of colony-forming unit (CFU) and long-term culture initiating cells (LTC-IC) colonies. The absolute number of CD34(+) cells in CB samples was determined by ProCOUNT trade mark and Stem Kit trade mark enumeration protocols. In liquid stored CB units, ProCOUNT trade mark and Stem Kit trade mark count differences are accounted for by the enumeration of CD34(bright) cells. Differences between ProCOUNT trade mark and Stem Kit trade mark counts using cryopreserved/thawed samples are accounted for by increased CD34(regular) FSC(low) cell numbers (2.0 +/- 1.4% in liquid stored and 27.8 +/- 14.6% in cryopreserved/thawed samples). The ProCOUNT trade mark assay includes the nonfunctional CD34(bright) and CD34(regular)FSC(low) cells as part of the CD34(+) cell count, thereby elevating the absolute number of CD34(+) cells. Using the Stem Kit trade mark assay method of gating, CD34(bright) and CD34(regular)FSC(low) cells are not counted. Our data indicate that the CD34(regular)FSC(high) cell population has functional characteristics based on the in vitro assays and a more accurate count of these cells can be achieved using the Stem Kit trade mark assay.
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Affiliation(s)
- Nicholas J Greco
- Blood & Cell Therapy Development Department, Biomedical Research & Development, American Red Cross, Rockville, MD 20855, USA.
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