Radiation Dose Determines Degree of Donor Chimerism after Nonmyeloablative Hematopoietic Cell Transplantation.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1828-1828 ◽  
Author(s):  
Christoph Kahl ◽  
Marco Mielcarek ◽  
Mineo Iwata ◽  
Michael Harkey ◽  
Barry Storer ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Radiation Dose ◽  
Low Dose ◽  
Donor Chimerism ◽  
Stem Cell Source ◽  
Cd34 Cells ◽  
Cell Source ◽  
Total Body

Abstract Efforts to replace total body irradiation (TBI) used for transplant conditioning with agents that have less acute and long-term toxicities require a better understanding of the biological effects of low dose TBI. We therefore retrospectively analyzed the role of radiation dose, stem cell source, and type of immunosuppression on both the stability and degree of donor chimerism in canine recipients of matched littermate hematopoietic cell transplants. Recipients were prepared with 200 cGy (n=26), 100 cGy (n=76) or 50 cGy (n=19) total body irradiation (TBI) at 7 cGy/min. Stem cell sources included bone marrow (BM) alone (n=58), BM plus G-CSF mobilized peripheral blood mononuclear cells (G-PBMC) (n=42), BM and CD14-depleted G-PBMC (n=13), or BM and T-cell-depleted G-PBMC (n=8). Posttransplant immunosuppression consisted of cyclosporin (CSP) only (n=53), CSP plus mycophenolate mofetil (MMF) (n=23), CSP and rapamycin (n=12), CSP, MMF and rapamycin (n=5); or CSP and MMF in combination with pretransplant immunosuppression (n=28). The percentage of donor granulocytes in the peripheral blood, as determined by PCR amplification of variable numbers of tandem repeats (VNTR), served as a marker for engraftment. TBI dose and stem cell source were both significantly associated with long-term (>26 weeks) stable engraftment in multivariate analysis (p=0.0001 and p=0.004, respectively). Among the 39 dogs with stable engraftment, however, TBI dose was the only factor examined that was associated with the degree of donor chimerism (mean % of donor granulocytes after 200 cGy, 100 cGy and 50 cGy of TBI: 65%, 52%, and 24%, respectively; p=0.008). To determine whether low-dose irradiation directly affected recipient stem/progenitor cell numbers and thereby conferred a competitive disadvantage to donor cells, CD34+ cells were isolated from two normal human donors. One preparation of CD34 cells was ex vivo irradiated (=200 cGy) and then injected into NOD/SCID beta2m-/- mice in combination with an equal number of unirradiated CD34 cells from the second donor. The contributions of each donor to human engraftment were assessed at 10 weeks by VNTR. After 200 cGy, the irradiated population contributed 74% less than expected, 24% less after 100 cGy, but only 6% less after 50 cGy. Flow analysis of Caspase-3 activation indicated that a significant percentage of cells irradiated with 200 cGy were apoptotic, and that this was associated with the loss of L-selectin and P-selectin glycoprotein ligand-1. In conclusion, our findings suggest that TBI, in addition to its well-characterized immunosuppressive effects, determines the degree of donor cell engraftment by directly compromising recipient stem cells, thereby providing a competitive advantage to donor stem cells.

Growth factor treatment prior to low-dose total body irradiation increases donor cell engraftment after bone marrow transplantation in mice

Blood ◽  
2002 ◽  
Vol 100 (1) ◽  
pp. 312-317 ◽  
Author(s):  
Estelle J. K. Noach ◽  
Albertina Ausema ◽  
Jan H. Dillingh ◽  
Bert Dontje ◽  
Ellen Weersing ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Growth Factors ◽  
Low Dose ◽  
Donor Cell ◽  
Hematopoietic Growth Factors ◽  
Cell Engraftment ◽  
Total Body

Abstract Low-toxicity conditioning regimens prior to bone marrow transplantation (BMT) are widely explored. We developed a new protocol using hematopoietic growth factors prior to low-dose total body irradiation (TBI) in recipients of autologous transplants to establish high levels of long-term donor cell engraftment. We hypothesized that treatment of recipient mice with growth factors would selectively deplete stem cells, resulting in successful long-term donor cell engraftment after transplantation. Recipient mice were treated for 1 or 7 days with growth factors (stem cell factor [SCF] plus interleukin 11 [IL-11], SCF plus Flt-3 ligand [FL], or granulocyte colony-stimulating factor [G-CSF]) prior to low-dose TBI (4 Gy). Donor cell chimerism was measured after transplantation of congenic bone marrow cells. High levels of donor cell engraftment were observed in recipients pretreated for 7 days with SCF plus IL-11 or SCF plus FL. Although 1-day pretreatments with these cytokines initially resulted in reduced donor cell engraftment, a continuous increase in time was observed, finally resulting in highly significantly increased levels of donor cell contribution. In contrast, G-CSF treatment showed no beneficial effects on long-term engraftment. In vitro stem cell assays demonstrated the effect of cytokine treatment on stem cell numbers. Donor cell engraftment and number of remaining recipient stem cells after TBI were strongly inversely correlated, except for groups treated for 1 day with SCF plus IL-11 or SCF plus FL. We conclude that long-term donor cell engraftment can be strongly augmented by treatment of recipient mice prior to low-dose TBI with hematopoietic growth factors that act on primitive cells.

scholarly journals Long-Term Cryopreservation Does Not Affect Quality of Peripheral Blood Stem Cell Grafts: A Comparative Study of Native, Short-Term and Long-Term Cryopreserved Haematopoietic Stem Cells

2021 ◽  
Vol 30 ◽  
pp. 096368972110360
Author(s):  
Daniel Lysak ◽  
Michaela Brychtová ◽  
Martin Leba ◽  
Miroslava Čedíková ◽  
Daniel Georgiev ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Statistical Significance ◽  
Extended Period ◽  
High Dose ◽  
Atp Production ◽  
Cd34 Cells ◽  
Negative Effect

Cryopreserved haematopoietic progenitor cells are used to restore autologous haematopoiesis after high dose chemotherapy. Although the cells are routinely stored for a long period, concerns remain about the maximum storage time and the possible negative effect of storage on their potency. We evaluated the effect of cryopreservation on the quality of peripheral stem cell grafts stored for a short (3 months) and a long (10 years) period and we compared it to native products.The viability of CD34+ cells remained unaffected during storage, the apoptotic cells were represented up to 10% and did not differ between groups. The clonogenic activity measured by ATP production has decreased with the length of storage (ATP/cell 1.28 nM in native vs. 0.63 in long term stored products, P < 0.05). Only borderline changes without statistical significance were detected when examining mitochondrial and aldehyde dehydrogenase metabolic activity and intracellular pH, showing their good preservation during cell storage. Our experience demonstrates that cryostorage has no major negative effect on stem cell quality and potency, and therefore autologous stem cells can be stored safely for an extended period of at least 10 years. On the other hand, long term storage for 10 years and longer may lead to mild reduction of clonogenic capacity. When a sufficient dose of stem cells is infused, these changes will not have a clinical impact. However, in products stored beyond 10 years, especially when a low number of CD34+ cells is available, the quality of stem cell graft should be verified before infusion using the appropriate potency assays.

scholarly journals Syngeneic and allogeneic bone marrow engraftment after total body irradiation: dependence on dose, dose rate, and fractionation

Blood ◽  
1991 ◽  
Vol 77 (3) ◽  
pp. 661-669 ◽  
Author(s):  
JD Down ◽  
NJ Tarbell ◽  
HD Thames ◽  
PM Mauch
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Radiation Dose ◽  
Dose Rate ◽  
Dose Response ◽  
Total Body Irradiation ◽  
Low Dose ◽  
Allogeneic Bone ◽  
Low Dose Rate ◽  
Total Body

Abstract Murine bone marrow chimera models were used to assess the efficacy of host total body irradiation (TBI) given at different doses, dose rates, and fractionation schemes in providing for engraftment of syngeneic and allogeneic bone marrow. B6-Hbbd congenic and LP mice, respectively, were used as donors (10(7) bone marrow cells) for syngeneic and allogenic (H-2 compatible) transplantation in standard B6 recipients. Stable marrow chimerism was determined from host and donor stem cell- derived hemoglobin phenotypes (Hbbs and Hbbd) on gel electrophoresis at 3 months posttransplant. Partial engraftment of syngeneic marrow was seen at single doses as low as 2 Gy, with the donor component increasing steadily with increasing TBI dose to a level of 100% at 7 Gy. Immunologic resistance of the host appeared to prevent allogeneic engraftment until 5.5 Gy. A very steep radiation dose response was then observed so that the level of chimerism with 6 Gy and above became comparable with syngeneic engraftment. Low dose rate (5 cGy minute-1) and fractionated TBI required higher total doses for equivalent engraftment (radiation dose-sparing) in both syngeneic and allogenic bone marrow transplantation. This displacement in the dose-response curve on fractionation was seen with interfraction intervals of 3 and 6 hours. A further dose-sparing effect was observed on extending the interval to 18 and 24 hours, but only for allogeneic transplantation, and may therefore be related to recovery of immune-mediated graft resistance. The involvement of multiple target cell populations in determining allogenic engraftment rendered the application of the linear-quadratic model for radiation cell survival problematic in this case. The recovery in dose when low dose rate and 6-hour interfraction intervals were applied in either syngeneic or allogeneic BMT is consistent with appreciable sub-lethal damage repair in the primitive self-renewing stem cell population of the host marrow. These results contrast with the poor repair capacity of the 11-day spleen colony- forming units (CFUs) population after fractionated irradiation and support the notion that ablation of early stem cells in the pre-CFUs compartment is essential for long-term marrow engraftment.

Effects of Chemical and Physical Shear-Stress Stimulation of Human Placenta-Derived Multipotent Stem Cells in Microchannel

2013 ◽  
Author(s):  
Chia-Wen Tsao ◽  
Meng-Zhi Chiang ◽  
Yu-Che Cheng
Keyword(s):  
Stem Cells ◽  
Shear Stress ◽  
Stem Cell ◽  
Human Placenta ◽  
Multipotent Stem Cells ◽  
Term Placenta ◽  
Stem Cell Source ◽  
Multipotent Cells ◽  
Cell Source ◽  
Stimulation Of

Multipotent cells obtain from human postpartum term placenta is an ethically conductive, easily accessible and high-yielding stem cell source. In this conference presentation, we demonstrate using microchannel platform to culture and differentiate the human placenta-derived stem cells. Both chemical and shear stress stimulation effects were investigated.

scholarly journals AMD3100 mobilizes hematopoietic stem cells with long-term repopulating capacity in nonhuman primates

Blood ◽  
2006 ◽  
Vol 107 (9) ◽  
pp. 3772-3778 ◽  
Author(s):  
André Larochelle ◽  
Allen Krouse ◽  
Mark Metzger ◽  
Donald Orlic ◽  
Robert E. Donahue ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hematopoietic Stem Cells ◽  
Genetic Manipulation ◽  
Retroviral Vectors ◽  
Lymphoid Cells ◽  
Alternative Source ◽  
Hematopoietic Stem ◽  
Cd34 Cells

AMD3100, a bicyclam antagonist of the chemokine receptor CXCR4, has been shown to induce rapid mobilization of CD34+ hematopoietic cells in mice, dogs, and humans, offering an alternative to G-CSF mobilization of peripheral-blood hematopoietic stem cells. In this study, AMD3100-mobilized CD34+ cells were phenotypically analyzed, marked with NeoR-containing retroviral vectors, and subsequently transplanted into myeloablated rhesus macaques. We show engraftment of transduced AMD3100-mobilized CD34+ cells with NeoR gene marked myeloid and lymphoid cells up to 32 months after transplantation, demonstrating the ability of AMD3100 to mobilize true long-term repopulating hematopoietic stem cells. More AMD3100-mobilized CD34+ cells are in the G1 phase of the cell cycle and more cells express CXCR4 and VLA-4 compared with G-CSF-mobilized CD34+ cells. In vivo gene marking levels obtained with AMD3100-mobilized CD34+ cells were better than those obtained using CD34+ cells mobilized with G-CSF alone. Overall, these results indicate that AMD3100 mobilizes a population of hematopoietic stem cells with intrinsic characteristics different from those of hematopoietic stem cells mobilized with G-CSF, suggesting fundamental differences in the mechanism of AMD3100-mediated and G-CSF-mediated hematopoietic stem cell mobilization. Thus, AMD3100-mobilized CD34+ cells represent an alternative source of hematopoietic stem cells for clinical stem cell transplantation and genetic manipulation with integrating retroviral vectors.

Increased Aldehyde Dehydrogenase Activity Indentifies a Subset of Human Leukemic Blasts with Stem Cell Characteristics and Correlates with Poor Prognosis.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1345-1345
Author(s):  
Dan Ran ◽  
Mario Schubert ◽  
Larissa Pietsch ◽  
Isabel Taubert ◽  
Christian Wallenwein ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Prognostic Factors ◽  
Aldehyde Dehydrogenase ◽  
Protein Level ◽  
Aldh Activity ◽  
Cd34 Cells ◽  
Dividing Cells

Abstract INTRODUCTION: Normal hematopoietic stem cells (HSC) are characterized by their ability to self-renew, to generate multiple cell-lineages, and show slow divisional kinetics. Leukemic stem cells (LSC) have been reported to show similar characteristics but their identification has been elusive. We have studied various methods and have identified aldehyde dehydrogenase (ALDH) staining as an optimal method for the enrichment of primary human LSC. MATERIAL&METHODS: Bone marrow samples were obtained from patients with newly diagnosed AML after informed consent. Mononuclear cells were stained with Aldefluor and sorted by flow cytometry according to their forward/side scatter characteristics and ALDH activity (ALDH+/ALDH−). Alternatively, primary AML samples were being enriched for CD34+ cells by magnetic column, then double-stained with CD34-antibodies and Aldefluor and sorted for the co-expression of CD34+ and ALDH+, respectively for CD34+ alone. Human Mesenchymal Stromal Cells (MSC), isolated from human bone marrow, were used as a surrogate model for the cellular microenvironment of the hematopoietic niche. Adhesion of various AML cell lines and subpopulations of primary leukemic cells (ALDH+, ALDH−, CD34+, CD34+/ALDH+, all blasts) to MSC was tested in the adhesion chamber assay. Semi-quantitative RT-PCR was used to analyze the gene expression of various adhesion molecules and Western- Blot analysis was performed to validate the PCR-results on protein level. The generation of secondary leukemic colonies was evaluated in a semi-solid methylcellulose medium, as well as in a long term co-culture system (LSC-IC assay; in analogy to the LTC-IC assay). RESULTS: The percentage of ALDH+ cells ranged from 0.01% to 13.2% with a median of 1.47% (n=55). Adhesion significantly differed in the ALDH+ and ALDH− subpopulations: 85±4% of ALDH+ cells but only 61±8% of ALDH− cells were adherent (n=11, p&lt;0.001). Adhesion molecules, such as CXCR4 and CD44, were highly expressed on the ALDH+ subpopulation both on mRNA level and protein level, in contrast to the ALDH− subpopulation. Analysis of the initial divisional kinetics on single cell base showed that the ALDH+ subpopulation contained more slow dividing cells whereas the majority of the ALDH− subpopulation consisted of fast-dividing cells (n=3; p&lt;0.01). The frequency of long term leukemic colony initiating cells (LSC-IC) was 3.82% in the ALDH+ but only 0.01% in the ALDH− (n=21; p&lt;0.01). In the CD34+ the LSC-IC frequency was 1.96% versus 0.01% in the CD34− (n=5, p&lt;0.01). The highest LSC-IC frequency could be monitored in ALDH+/CD34+ cells: 6.1% generated secondary leukemic colonies (n=5). These colonies, harvested after 7 weeks of cultivation, were examined for their immune phenotype and screened for cytogenetic aberrations by fluorescent in situ hybridization (FISH) and the chromosomal aberrations were consistent with the AML samples taken at diagnosis. Furthermore, the frequency of ALDH+ cells correlated significantly with adverse prognostic factors: patients with a high-risk karyotype had a mean of 2.9% ALDH+ cells (n=21); in contrast, patients with a normal karyotype had a mean of 0.4% ALDH+ cells in their bone marrow (n=34; p&lt;0.001). The ability of ALDH+ versus ALDH− subsets to generate secondary leukemia in the animal model is concurrently examined. DISCUSSION: In summary, measurement of the ALDH activity provides a useful tool for the isolation of a distinct AML-blast subpopulation with stem-cell like features (LSC). The ALDH+ subsets showed higher affinity to the surrogate niche (MSC), elevated expression of CD44, Cadherin-2, and CXCR4 and were associated with an increased frequency of secondary leukemic colonies in vitro (LSC-IC). Above all, the frequency of ALDH+ blasts correlated with clinical prognostic factors, which substanciates LSC as a relevant therapeutic target.

Cyclophosphamide-Busulfan Instead of Busulfan-Cyclophosphamide for Conditioning in Allogeneic Hematopoietic Stem Cell Transplantation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2268-2268
Author(s):  
Nathan Cantoni ◽  
Sabine Gerull ◽  
Dominik Heim ◽  
Joerg Halter ◽  
Dimitrios Tsakiris ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cumulative Incidence ◽  
Liver Toxicity ◽  
Conditioning Regimen ◽  
Hematopoietic Stem ◽  
Allogeneic Hsct ◽  
Stem Cell Source ◽  
Cell Source ◽  
Donor Type ◽  
Total Body

Abstract Abstract 2268 Poster Board II-245 Busulfan-cyclophosphamide (BU-CY) is the established non total body irradiation based myeloablative conditioning regimen for allogeneic hematopoietic stem cell transplantation (HSCT). The introduction of intravenous busulfan has facilitated its application and reduced toxicity. Theoretical considerations and pharmacological data indicate that previous application of busulfan may trigger liver toxicity of subsequent cyclophosphamide. A reverse order of cyclophosphamide-busulfan (CY-BU) would be preferable. Recent animal data confirmed this hypothesis, showing less liver toxicity and better outcomes in mice treated with CY-BU. While CY-BU was not feasible in patients with oral busulfan, it has become a possibility with the introduction of i.v. busulfan. We were therefore interested in exploring this concept and changed the order of drug application to CY-BU in 2003 in those patients not on a multicentre standardized BU-CY protocol. We now retrospectively analyzed in this single centre cohort study liver toxicity and transplantation outcome in patients receiving BU and CY as conditioning regimen for allogeneic HSCT. We analyzed 93 consecutive patients between 1993 and 2008, 52 male (55.9%), median age 46 years (range 16 to 70) with hematological malignancies (AML 41 [44.1%], ALL 11 [11.8%], CML 12 [12.9%], myelodysplastic syndrome and myeloproliferative neoplasia 22 [23.7%], lymphoproliferative disorders 4 [4.3%]) or other diseases (3 [3.2%]), receiving an allogeneic HSCT from an HLA- identical sibling (52 [55.9%]), other family member (3 [3.2%]) or a matched unrelated donor (38 [40.9%]) after conditioning regimen with BU-CY (34 patients; 18 patients with oral, 16 patients since 2003 with i.v. busulfan) or CY-BU (59 patients). Outcomes were analyzed using a Cox regression model, adjusting for disease, stage, donor type, stem cell source, previous total body irradiation (TBI) and busulfan administration (oral vs. intravenous). Pretransplant patient characteristics were comparable in the two cohorts for age, gender, underlying disease, stem cell source, donor type and EBMT risk score, but differed in stage (advanced disease BU-CY 28 [84,8%] vs. CY-BU 40 [66.7%]) and previous TBI (BU-CY 16 [48.5%] vs. CY-BU 9 [15.0%]). Liver function as measured by levels of bilirubin and liver enzymes (aspartate amino transferase [AST], alanine amino transferase [ALT], gamma glutamyl transpeptidase [GGT] and alkaline phosphatase [AP]) was not different between the groups before starting conditioning regimen. In contrast liver function differed significantly at day 20, with higher levels of ALT (median 51.0 vs 27.0 IU/l; p=0.012) and a higher incidence of veno-occlusive disease (VOD) (5/34 vs. 1/59, p=0.036) in the BU-CY group (Figure 1A). The cumulative incidence of transplant-related mortality (TRM) at 2 years was significantly higher in patients receiving BU-CY (BU-CY 0.48, CY-BU 0.24, p=0.024; hazard ratio 4.594 for BU-CY, 95% CI 1.382-15.268, p=0.013) (Figure 1B). The cumulative incidence of TRM with BU i.v.-CY was lower (0.44) than with BU oral-CY (0.56) but still higher than CY-BU. This did translate into a higher overall survival in patients after conditioning regimen with CY-BU (hazard ratio for mortality 0.426 for CY-BU, 95% CI 0.184-0.987, p=0.047). Time to engraftment (BU-CY median 13 days vs. CY-BU median 14 days), cumulative incidence of acute GVHD and relapse were similar between patients receiving BU-CY or CY-BU. These data support the concepts derived from Sadeghi et al in their mouse model in favor of CY-BU compared to the traditional BU-CY. They form the basis for prospective controlled studies. Disclosures: No relevant conflicts of interest to declare.

Use of Plerixafor to Overcome Stem Cell Mobilization Failure: Long Term Follow up of Patients Proceeding to Transplant Using Plerixafor Mobilized Stem Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4390-4390 ◽  
Author(s):  
Abhinav Deol ◽  
Judith Abrams ◽  
Ashiq Masood ◽  
Zaid Al-Kadhimi ◽  
Muneer H. Abidi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Side Effects ◽  
Cell Count ◽  
Peripheral Blood ◽  
Cd 34 ◽  
Cd34 Cells ◽  
Significant Difference

Abstract Abstract 4390 Background: Plerixafor is a CXCR 4 antagonist which is now approved for use for stem cell (SC) mobilization with granulocyte colony stimulating factor (GCSF) in patients with non Hodgkin lymphoma (NHL) or multiple myeloma (MM). Prior to the approval of plerixafor, we enrolled 49 patients in a compassionate use protocol at our institution to mobilize SC for patients who previously failed at least one mobilization attempt. Methods: Patients received 0.24 mg/kg of plerixafor subcutaneously 9 –11 hrs prior to apheresis in addition to twice daily GCSF. Results: Median age of the patients was 64 years (range, 23–74 years). NHL was the most common diagnosis in 27 (55%) patients, followed by MM with 17(35%) patients and HD with 5 (10%) patients. Thirty nine patients (80%) had been treated with more than 2 chemotherapeutic regimens prior to the first attempt at stem cell collection. Thirty seven patients (76%) failed one previous mobilization attempt, while 12 (24%) had failed 2 or more previous attempts. Using the combination of Plerixafor and GCSF we collected ≥ 2.5 × 106 CD34+ cells/Kg in 33 patients (67%). The median days for pheresis were 1 day with a range of 1 to 3 days. The median SC dose collected was 4 × 106 CD34+ cells/Kg, with a range 2.5 – 14.3. The median CD-34+ peripheral blood count on the 1st day of their collection with plerixafor was 22.4/uL. In contrast the median peripheral blood CD-34+ cell count in these patients on the day of their first collection which failed was 6.2 /uL. The median increase using G-CSF and plerixafor was 14.9 CD-34+ cells/uL. We collected ≥ 2.5 × 106 CD34+ cells/Kg on 4/5 (80%) patients with HD, 13/17 (76%) patients with MM and 16/27 (59%) patients with NHL. Sixteen patients (33%) collected < 2.5 × 106 CD34+ cells/Kg. The median cell dose collected in these patients was 1.4 × 106 CD34+ cells/Kg with a range, 0.4–2.2. The median number of days of pheresis was 2 days (range, 1–4 days). In these16 patients the median CD-34+ count on the day of their previous failed collection was11.2/uL. Their CD-34+ cell count on their first day of collection after the use of G-CSF and plerixafor was 8.3/ul. Figure 1 shows the change in peripheral CD34 counts with the prior mobilization attempt and after plerixafor mobilization, for 38 patients in whom data was available. The most common side effects attributed to plerixafor were diarrhea, fatigue, thrombocytopenia and bone pain; observed in 12%, 8%, 8% and 6% patients, respectively. Forty three of the 49 patients proceeded to an autologus peripheral blood SC transplant, 34 patients received ≥ 2.5 × 106 CD34+ cells/Kg. Thirty two of these patients used the plerixafor collection as the only source of SC. Two patients had their plerixafor mobilized SC combined with a previous suboptimal SC collection. Nine patients received < 2.5 × 106 CD34 + cells/Kg; 4 patients received plerixafor mobilized SC alone, 5 patients received plerixafor mobilized SC combined with their previously mobilized SC. The preparative regimens used were R- BEAM (20 patients), Melphalan (16 patients), BEAM (6 patients) and Etoposide+TBI (1 patient). All patients received GCSF from day +6 till WBC engraftment. The median days of WBC and platelet engraftment were day +11 (range, 9–13 days) and day +16 (range, 11–77 days), respectively. There was no significant difference in days to engraftment between the patients who collected greater or less than 2.5 × 106 CD34 + cells/Kg. With a median follow up 13.7 months, long term engraftment data is available on 27 patients. The median white cell count, hemoglobin and platelet count 1 year after transplant was 4.7 × 109/L, 12.2 g/dL and 109 ×109/L, respectively. There was no significant difference in counts at the 1 year mark between patients who collected more or less than 2.5 × 106 CD34 + cells/Kg. To date 15 patients have evidence of disease progression. Two patients have developed MDS/AML post transplant. Conclusion: Overall, plerixafor leads to mobilization of sufficient stem cells in a vast majority of patients who have failed previous mobilization attempts and allows more patients to proceed to an autologous SC transplant. Plerixafor is well tolerated with minimal side effects, acceptable time to engraftment and acceptable peripheral blood counts at 1 yr after the transplant. Our analysis suggests that failure to increase peripheral CD34 count after plerixafor when compared to previous attempts may predict unsuccessful mobilization. Disclosures: Lum: Transtarget Inc: Equity Ownership, Founder of Transtarget.

Pre-/Post-HSCT Imatinib Improves Survival of Childhood with BCR/ABL+ Acute and Chronic Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5248-5248
Author(s):  
Fuyu Pei ◽  
Qi Li ◽  
Wenfeng Xu ◽  
Zhiyong Peng ◽  
Xuedong Wu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Myeloid Leukemia ◽  
Myelogenous Leukemia ◽  
Hematopoietic Stem ◽  
Post Transplant ◽  
Stem Cell Source ◽  
Significant Difference ◽  
Cell Source

Abstract Objective:To evaluate the effect of hematopoietic stem cell transplantation (HSCT) for children with leukemia in our center in recent years. Methods: We retrospectively analyzed data of 87 patients with leukemia underwent HSCT at a median age of 8 years from February 2006 to December 2013 in our center. The median follow-up time was 28 months (range, 2-96), the ratio of male to female patients was 59:28. Conditioning regimen included cyclophosphamide, fludarabine, busulfan with or without (w/o) thiotepa. Anti-thymocyte globulin and cytarabine were individually used for the patients with lymphoid leukemia and myeloid leukemia. GVHD prophylaxis included tacrolimus, mycophenolate mofetil w/o post-transplant cyclophosphamide. Median nucleated cells: 3.75 (1.16`7.56) × 107/Kg. Patients with BCR/ABL+ acute lymphoblastic leukemia (ALL) received imatinib before and after transplant over 6 months per each one. Twenty-six patients received transplant from sibling donors, 31 from haploidentical donor, 30 from unrelated donors; Status before transplant were grouped as CR1 (n= 57), CR 2 (n=13), CR 3 (n=1) and NR (n=16). Source of stem cells included PBSC in 40 cases, UCB in 3 cases, BM in 24 cases, BM+PBSC in 9 cases, and mixed stem cells (BM /PBSC+ UCB) in 11 cases. Results: The estimated 5-year overall survival (OS) was 56.8 ± 5.8% in total.Among them, OS was 54.3 ± 8.0% in 45 patients with ALL; 85.7 ± 13.2% in 8 patients with BCR/ABL+ALL; 48.6 ± 8.7% in 37 patients with BCR/ABL-ALL. 32.8 ± 15% in 29 patients with acute myeloid leukemia and 82.5 ± 11.3% in 13 patients with chronic myelogenous leukemia, respectively. Single factor analysis showed there was no significant difference for OS in comparison of BCR/ABL+ALL, BCR/ABL-ALL, AML and CML (P=0.057), but patients with BCR/ABL+ALL had higher OS compared to those with BCR/ABL-ALL (P=0.048) and to AML (P=0.040). In comparison of difference status before transplant, OS were 55.2 ± 11.6%, 54.9 ± 15.6%, 0,and 27.5 ± 11.6% in CR1, CR2, CR3 and NR, respectively (P=0.025). OS was higher in CR1 than NR (P=0.005). When comparing stem cell source, OS was 65.5 ± 8.5%, 0%, 41.7 ± 11.4%, 33.3 ± 15.7%, and 72 ± 17.8% in PBSC, unrelated CB (UCB), BM, BM+PBSC, and BM/PBSC+UCB transplants, respectively (P=0.003); PBSC transplant associated with higher OS than BM (P=0.049) and BM+PBSC (P=0.009); and BM/PBSC+UCB mixed transplant had highest OS (P=0.026). Multivariate analysis showed Risk factors for OS only remained stem cell source (P=0.046) and status before transplantation (P=0.048). the transplant types (P=0.023), and follow up time(P=0.017). Conclusion: Comparing with data reported in literature we have similar outcomesin total for childhood with leukemia. Use of imatinib pre-/post-transplant for patients with BCR/ABL+ALL conduces to the highest OS in current study. Stem cell sources and the status before transplant have a significant effect on OS. Disclosures No relevant conflicts of interest to declare.

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