CD34⁺Cell Enrichment for Autologous Peripheral Blood Stem Cell Transplantation by Use of the CliniMACS Device

Abstract

Several devices for selection of CD34+ peripheral blood stem cells (PBSC) have been used during the last years for reducing tumor cell contamination of the graft. The new CliniMACS system (magnetic-activated cell separation system by Miltenyi Biotech GmbH, Bergisch-Gladbach, Germany) was recently approved for clinical use in Europe. To evaluate its purging efficiency and engraftment data in the autologous transplant, PBSC from 28 adult patients with various malignant diseases (non-Hodgkin's lymphoma, n = 17; chronic lymphocytic leukemia, n = 5; multiple myeloma, n = 4; acute lymphocytic leukemia, n = 1; medulloblastoma, n = 1) were mobilized by chemotherapy and granulocyte colony-stimulating factor (G-CSF) (10 microg/kg per day). Thirty leukapheresis products from 28 patients with a median of 4.4 x 10(8) nucleated cells/kg body weight (bw)(range 0.6-10.8 x 10(8)/kg bw) and a median of 7.1 x 10(6) CD34+ cells/kg bw (range 2.8 to 18.8 x 10(6)/kg bw) were selected using the Cobe spectra cell separator (Cobe BCT Inc., Lakewood, CO). After the CliniMACS procedure, the median yield of CD34+ selected cells was 4.5 x 10(6)/kg (range 2.2-11.1 X 10(6)/kg bw) with a median recovery of 69.5% (range 46.9-87.3%) and a median purity of 97.7% (range 89.4-99.8%). The procedure did not alter viability of selected cells, which was tested by propidium iodide staining. So far, purified PBSC were used for autologous transplantation in 15 out of 28 patients after total body irradiation and/or high-dose chemotherapy. Median time to reach an absolute neutrophil count > 500/microl was 12 days (range 10-18 days), platelet recovery >50,000/microl occurred at day + 16 (range 11-22). With a median follow-up time of 12 months (range 3-19), 5 patients died of relapse. We confirmed the feasibility and safety of the CliniMACS CD34+ cell enrichment procedure in adult patients with autologous PBSC transplantation.

Relapse risk after autologous transplantation in patients with newly diagnosed myeloma is not related with infused tumor cell load and the outcome is not improved by CD34+ cell selection: long term follow-up of an EBMT phase III randomized study

“…A variety of approaches have been developed in an attempt to improve the outcome of high-dose therapy in multiple myeloma patients, including tandem highdose therapy, 25,26 reduced intensity allogeneic transplantation ,27,28 purging strategies based either on negative or positive selection, [29][30][31][32][33][34][35][36][37][38][39] and new approaches to conditioning. Although the present study used a combination of melphalan and TBI for conditioning, it has since been established that high dose melphalan alone is less toxic and at least as effective as regimens including total body irradiation.…”

Impaired stem cell function of CD34+ cells selected by two different immunomagnetic beads systems

“…[4][5][6][7][8][9][10][11][12][13][14][15][16][17] In general, approximately 80% of CD34 þ cells were recovered when both the CD34 þ and CD34 À cell fractions were Stem cell function of immunomagnetically separated CD34 þ cells T Kimura et al combined (Figures 1a and 3a), while approximately 20% of the CD34 þ cells were lost during processing by either device.…”

“…1 Therefore, positive selection of CD34 þ peripheral blood stem cells (PBSCs) is employed for both allogeneic and autologous hematopoietic stem cell (HSC) transplantation. 2,3 So far, two immunomagnetic beads systems, the Isolex 300 (300i) [4][5][6][7][8][9][10][11][12] and the CliniMACS, [13][14][15][16][17] have been widely used in the clinical field. Most studies have shown that rapid and stable neutrophil and platelet engraftment occurs in patients who receive at least 2 Â 10 6 CD34 þ cells/kg.…”

“…Most studies have shown that rapid and stable neutrophil and platelet engraftment occurs in patients who receive at least 2 Â 10 6 CD34 þ cells/kg. 5,6,[9][10][11][13][14][15][16] However, previous studies have only assessed the efficiency of CD34 þ cell recovery, CD34 þ cell purity, depletion of CD3 þ T lymphocytes, and tumor cell purging. Therefore, it is necessary to more precisely elucidate the functional property of the CD34 þ cells selected by these immunomagnetic beads systems, since the detailed properties of selected CD34 þ hematopoietic stem/progenitor, especially their long-term bone marrow (BM) repopulating activity, have not yet been fully elucidated.…”

High‐throughput laser‐mediated in situ cell purification with high purity and yield

“…In drug discovery, homogeneous populations of cells overexpressing a particular drug target or reporter gene are necessary for high-throughput screening campaigns that may span several months and hundreds of thousands of candidate drugs (4). Cell purification technologies have even affected medical practice, such as the use of magnetic bead and other systems to eliminate tumor cells from autologous HSC transplants or to eliminate T cells from allogeneic HSC transplants (5)(6)(7).…”