Publications by authors named "Bernard Dazey"

Article Synopsis
  • Over a 10-year study, 999 UCB units were used to treat 796 patients, with a notably high median cell dose, leading to improved neutrophil engraftment and faster recovery, particularly in those receiving higher cell doses.
  • The findings highlighted that higher cell counts in banked UCB units were linked to better transplant outcomes, making cell dose the most significant factor affecting patient survival rates after the procedure.
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Background: Umbilical cord blood (UCB) has been used as an alternative source of donor hematopoietic stem cells for hematologic transplant setting over the past decade. This study attempted to evaluate potential predictors of cord blood quality.

Methods: A total of 750 UCB samples were studied (male, n = 365; female, n = 385).

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During storage and transportation of collected cord blood units (CBUs) to the bank prior to their processing and cryopreservation, it is imperative to preserve the functional capacities of a relatively small amount of cells of interest (stem and progenitor cells) which are critical for graft potency. To improve CBU storage efficiency, we conceived an approach based on the following two principles: (1) to provide a better nutritive and biochemical environment to stem and progenitor cells in CB and (2) to prevent the hyperoxygenation of these cells transferred from a low- (1.1%-4% O2 in the CB) to a high-oxygen (20%-21% O2 in atmosphere) concentration.

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We recently developed a clinical grade ex vivo cord blood expansion procedure enabling a massive amplification of hematopoietic progenitors without any loss of stem cell potential. This procedure, based on day 14 liquid cultures of cord blood CD34(+) cells, in medium Macopharma HP01 and in the presence of stem cell factor (SCF; 100 ng/ml), fms-related tyrosine kinase 3-ligand (Flt-3L; 100 ng/ml), megakaryocyte growth and developmental factor (MGDF; 100 ng/ml), and granulocyte colony-stimulating factor (G-CSF; 10 ng/ml) had to be modified due to the commercially unavailability of clinical grade MGDF molecule. So MGDF was replaced by thrombopoietin (TPO) in fivefold lower dose (20 ng/ml), and culture time was reduced to 12 days.

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We developed a clinical-scale cord blood (CB) cell ex vivo procedure to enable an extensive expansion of committed progenitors--colony-forming cells (CFCs) without impairing very primitive hematopoietic stem cells (HSCs). CD34(++) cells, selected from previously cryopreserved and thawed CB units, were cultured in two steps (diluted 1:4 after 6 days) in the presence of stem cell factor (SCF), fms-related tyrosine kinase 3 ligand (Flt-3L), megakaryocyte growth and development factor (MGDF) (100 ng/ml each), granulocyte-colony stimulating factor (G-CSF) (10 ng/ml) in HP01 serum-free medium. HSC activity was evaluated in a serial transplantation assay, by detection of human cells (CD45, CD33, CD19 and CFC of human origin) in bone marrow (BM) of primary and secondary recipient NOD/SCID mice 6-8 weeks after transplantation.

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Background: The first protocol of ex vivo expansion that enabled almost total abrogation of postmyeloablative chemotherapy neutropenia was based on a three-cytokine cocktail (stem cell factor [SCF], granulocyte-colony-stimulating factor [G-CSF], pegylated-megakaryocyte growth and development factor [PEG-MGDF]) in a serum-free medium. Since the clinical-grade molecule MGDF is no longer available on the market, we evaluated its substitution by thrombopoietin (TPO).

Study Design And Methods: CD34+ cells of myeloma patients were expanded for 10 days in serum-free cultures with SCF, G-CSF, or MGDF (100 ng/mL) or with TPO (2.

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Background: Herein are reported the results obtained in all multiple myeloma patients transplanted with peripheral blood hematopoietic progenitor cells submitted to ex vivo expansion.

Study Design And Methods: Patients had blood progenitor cell mobilization with cyclophosphamide and filgrastim. CD34+ cells were expanded for 10 days in a medium containing granulocyte-colony-stimulating factor (G-CSF), stem cell factor, and megakaryocyte growth and development factor (MGDF).

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Background: The autologous transplantation of CD 34+ cells expanded ex vivo in serum-free conditions dramatically reduces post-myeloablative neutropenia in myeloma patients. In our cell therapy unit, cells for this clinical assay have been expanded under GMP with serum-free Irvine Scientific (IS) medium with stem cell factor (SCF), granulocyte-colony-stimulating factor (G-CSF), and megakaryocyte growth and development factor (MGDF; 100 ng/mL, respectively). Because this clinical-grade IS medium is no longer available, a new serum-free medium, Maco Biotech HP 01 (Macopharma), was evaluated.

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Background: Used leuko-depletion filters (LDFs), containing billions of white blood cells (WBCs), are discarded. Because the steady-state blood contains low quantities of stem and progenitor cells that are retained in LDFs, the viability and the functional properties of mononuclear cells (MNCs) and CD 34+ cells recovered from LDFs were investigated.

Study Design And Methods: WBCs were recovered from LDFs by use of a closed system.

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In the present work, we tested the hypothesis that liquid cultures (LCs) of cord blood CD34+ cells at an appropriate low O2 concentration could simultaneously allow colony-forming cell (CFC) expansion and nonobese diabetic/severe combined immunodeficiency mice-repopulating cell (SRC) maintenance. We first found that 3% was the minimal O2 concentration, still allowing the same rate of CFC expansion as at 20% O2. We report here that 7-day LCs of cord blood CD34+ cells at 3% O2 maintain SRC better than at 20% O2 and allow a similar amplification of CFCs (35- to 50-fold) without modifying the CD34+ cell proliferation.

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Background: Mobilized PBPCs, detectable on the basis of CD34 expression, can be collected on various cell separators. The CD34+ cell collection efficiencies of two cell separators (CS-3000+ and Amicus, Baxter) were tested on two comparable groups of oncology patients.

Study Design And Methods: Leukapheresis assisted by the standard manufacturer's software and variables settings was performed in 37 (CS-3000+) and 34 (Amicus) patients (total of 83 and 67 collections, respectively) after chemotherapy plus G-CSF treatment.

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