Isolation of CD34+ progenitor cells from peripheral blood by use of an automated immunomagnetic selection system: factors affecting the results

Summary:With the increasing frequency of haploidentical transplantation, it is becoming more important to establish the degree of HLA mismatch that can be accepted. We retrospectively analyzed clinical data of 50 adult Japanese patients with high-risk hematologic malignancies who underwent allogeneic peripheral blood stem cell transplantation (PBSCT) from two-or three-loci-mismatched related donors with HLA class I and II gene disparities in the graft-versus-host direction. They were treated at 20 transplant centers between 1996 and 2002. In all, 18 patients received unmanipulated PBSC, while 32 received purified CD34 þ blood cells. Conventional (n ¼ 31) or reduced-intensity (n ¼ 19) conditioning regimens were used. Of the 39 patients (78%) who survived for X28 days after transplant, 37 (95%) achieved neutrophil engraftment, while graft failure and rejection occurred in two of 39 (5%) and three of 37 (8%) patients, respectively. Stepwise Cox regression analysis revealed a significantly lower incidence of grades II-IV acute GVHD in patients receiving purified CD34 þ cells (hazard ratio 0.32; 95% CI 0.12-0.84; P ¼ 0.022). By 1 year post transplant, 28 patients (56%) had died of transplantrelated problems, including infectious complications (30%). Although the number of patients is small, our data suggest that transplant-related problems, particularly infectious complications, are major obstacles to the success of this therapy.

Section: Stem Cell Collection and Graft Manipulationmentioning

confidence: 99%

Allogeneic peripheral blood stem cell transplantation from two- or three-loci-mismatched related donors in adult Japanese patients with high-risk hematologic malignancies

Yamasaki

Ohno

Taniguchi

et al. 2003

“…Collection was performed in one (10 donors) 21 Cells were directly infused without cryopreservation.…”

Section: Stem Cell Collection and Processingmentioning

confidence: 99%

Individually adjusted prophylactic donor lymphocyte infusions after CD34-selected allogeneic peripheral blood stem cell transplantation

Ferrà

Rodríguez-Luaces

Gallardo

et al. 2001

Summary:T cell depletion of the graft increases graft failure and relapse rate in allogeneic PBSC transplantation. Delayed lymphocyte add-back after T cell-depleted transplants might prevent these complications. We The success of allogeneic progenitor stem cell transplantation is mainly limited by the morbidity and mortality caused by GVHD and tumor relapse. Donor T-lymphocytes play a critical role in the pathogenesis of GVHD, which may therefore be prevented by T cell depletion of the graft. However, T-lymphocytes facilitate donor engraftment and contribute to the eradication of various hematologic malignancies. T cell depletion of the graft has been associated with a higher incidence of graft-failure and leukemia relapse. 1-3Many strategies have been tested in order to prevent GVHD without compromising the GVL effect: partial T cell depletion of a specific subset of lymphocytes; 4 maintenance of a minimal threshold of lymphocytes in the depleted graft; 5 or recently, the administration of delayed DLI.6-9 DLI reverts disease relapse after allogeneic transplantation, which indicates that delayed donor lymphocytes retain their antitumor effect. [10][11][12][13] Moreover, in a murine model the timing of DLI appears to influence the induction of GVHD. 14 Mobilized PBSC from the donor have been used for allogeneic transplantation, 15 but this approach is associated with a higher incidence of chronic GVHD.16,17 Allogeneic transplantation of CD34 + -selected cells has been used to decrease GVHD incidence. 18,19 Prophylactic or pre-emptive DLI after hematopoietic stem cell transplant may prevent relapse. This approach has been used in small groups of patients receiving allogeneic bone marrow transplantation with promising results. 6,7,9 However, there are few data on this approach after CD34-selected allogeneic PBSC transplantation. 8,20 As GVHD induced by T cells from the donor is associated with a GVL effect, we aimed to conserve the antileukemic effect, while preventing and controlling GVHD through the delayed administration of increasing doses of T-lymphocytes.We designed a protocol in which prophylactic DLI was adjusted for each patient depending on their risk of relapsing or developing GVHD, in order to derive the maximal

“…The manufacturer's recommendations were followed with minor modifications as reported elsewhere. 9 Max-Sep for negative selection: A negative selection step was performed afterwards in an attempt to optimize the TCD to that achieved with the positive selection process. The CD34 + cell-enriched component obtained with the Isolex 300i was transferred to a Lifecell bag (Baxter).…”

Section: Donorsmentioning

confidence: 99%

“…9 Briefly, cells were incubated with human AB serum and anti-CD34-PE MoAb (8G12, HPCA-2; Becton Dickinson, San Jose, CA, USA) for 15 min at RT in the dark. After washing twice, the samples were incubated for 10 min at RT with ammonium chloride (Ortho Lysing Reagent; Ortho, Raritan, NJ, USA) for erythrocyte lysis.…”

Section: Cytometry Analysesmentioning

confidence: 99%

“…The target cells-9C5 complexes are then captured by sheep antimouse IgG-coated paramagnetic beads (IB) (SAM-M450; Dynabeads, Dynal, Oslo, Norway) and in a final step target cells are released from the 9C5-IB complexes by a peptide that binds competitively to the 9C5 MoAb. 8 This method achieves between 3 and 4 logs of TCD, 9 thus resulting in T cell doses in the allograft lower than those suggested to trigger aGVHD in the T cell-depleted BM of the HLAmatched setting. [10][11][12][13] However, in recipients of HLAmismatched or haploidentical donor grafts, a higher TCD of the graft may be required to avoid aGVHD.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Combined positive and negative cell selection from allogeneic peripheral blood progenitor cells (PBPC) by use of immunomagnetic methods

Martín-Henao

Picón

Amill

et al. 2001

Summary:Twenty-four mobilized peripheral blood products from healthy donors for allogeneic transplantation were positively selected for CD34 + cells and depleted of CD4 + and CD8 + cells (+/− selection) by combining clinical grade immunomagnetic methods. A sequential, 'two-step' strategy combining positive selection of CD34 + cells by use of the Isolex 300i (versions 1 and 2) device and T cell depletion (TCD) using the MaxSep device and a simultaneous, 'one-step' method of CD34 + cell selection and TCD using the Isolex 300i (software versions 1 and 2) have been investigated. Using these magnetic bead separation systems, two groups of sequential +/− selection (Isolex 300i version 1/MaxSep and Isolex 300i version 2/MaxSep) and two groups of simultaneous +/− selection (Isolex 300i versions 1 and 2) were analysed. In the sequential +/− selection, logarithms of TCD (CD3 + cell depletion) obtained by the positive selection step had median values of 3.7 with the version 1 (n = 5) and 4.5 with version 2 software of the Isolex 300i (n = 5) (P = 0.07). Version 2 also gave a higher CD34 + cell purity and yield than did version 1 (92% vs 77%, P Ͻ 0.05 and 55% vs 34%, P = 0.3, respectively). Additional TCD obtained in the second step with the MaxSep device for the two groups had a median value of 0.9 log and 7% CD34 + cell losses. In the simultaneous +/− selection, the Isolex 300i version 2 (n = 10) gave a median TCD of 5.1 log and version 1 (n = 4) of 4 log (P Ͻ 0.005). Higher CD34 + cell purity and yield were also obtained with version 2 than with version 1 (97% and 76%, P Ͻ 0.005 and 57% and 39%, P = 0.07, respectively). These data indicate that simultaneous, 'one-step' +/− selection in the Isolex 300i version 2 achieves a high TCD with a high CD34 + cell purity and an acceptable CD34 + cell yield. Bone Marrow Transplantation ( The development of HLA-mismatched or haploidentical donor stem cell transplantation requires a high degree of T cell depletion (TCD) while preserving an adequate number of CD34 + cells in the graft in order effectively to prevent acute graft-versus-host disease (aGVHD) and ensure engraftment. [1][2][3] Several reasons make CD34 positive cell selection methods (positive selection, + selection) particularly attractive to deplete T cells especially in peripheral blood progenitor cell (PBPC) grafts: they can be applied to the large numbers of cells present in PB, they are able to preserve adequate numbers of progenitors after selection, thus maintaining the potential benefits of a PBPC transplant in this setting and they passively deplete the elevated numbers of T cells present in the PB grafts.Several methods are available for positive selection. 4-7 The immunomagnetic technique, which is now exploited by the Isolex 300i cell selection technology (Nexell Therapeutics, Irvine, CA, USA), involves specific binding of target cells by a mouse anti-CD34 MoAb, 9C5. The target cells-9C5 complexes are then captured by sheep antimouse IgG-coated paramagnetic beads (IB) (SAM-M450; Dynabeads, Dynal, Oslo, Norway)...