Isolation and transplantation of autologous peripheral CD34+ progenitor cells highly purified by magnetic-activated cell sorting

Abstract

Summary:Peripheral stem cells were mobilized and collected in 26 pediatric patients with malignant diseases. A total of 47 leukaphereses were performed in the 26 patients. The mean number of nucleated cells collected was 4.5 ؎ 2.6 × 10 8 /kg and the number of CD34 ؉ progenitors collected was 6.7 ؎ 6.8 × 10 6 /kg. CD34-positive selection was performed using a two-step method of magnetic-activated cell sorting (MACS) in 24 patients or a combination of an immunoaffinity column and MACS in two patients. The purity of the positively selected CD34؉ progenitors was 98.8 ؎ 0.7% and the number of isolated CD34 ؉ cells was 6.5 ؎ 5.9 × 10 6 /kg. Thus, the mean recovery of CD34 ؉ cells was 93 ؎ 10%. In 22 of the 26 patients, high-dose chemotherapy was performed with subsequent reinfusion of the highly purified CD34 ؉ cells. In all 22 patients, a normal hematopoietic reconstitution was seen with a mean time of 12.4 ؎ 2.7 days to reach Ͼ0.5 × 10 9 /l neutrophils (range 8-19 days). The time to reach independence from platelet transfusion was 31.6 ؎ 17.0 days (range 16-78 days). There were no transplant-related deaths. In summary, we have shown that mobilized peripheral CD34 ؉ progenitors can be highly purified with a good recovery and that reinfusion of these cells after high-dose chemotherapy results in a rapid, complete and sustained engraftment. We conclude that this method can be used for purging in any CD34-negative malignancies and for autologous T and B cell depletion in the treatment of autoimmune diseases with high-dose immunoablative therapy.

Allogeneic bone marrow stem cell transplantation following CD34+ immunomagnetic enrichment in patients with inherited metabolic storage diseases

“…However, the efficiency of CliniMACS in terms of CD34+ purity and T-cell reduction was comparable with that observed in previous studies. [7][8][9] The aim of HSCT in this setting is not simply to improve survival with normal enzyme activity, but also to stabilize or enhance neuropsychological function thereby promoting Table 2 Cell composition of unmanipulated bone marrow, buffy coat and positively selected product quality of life and patient independence. Therefore, prevention of the potential demyelinating effects because of toxicity and/or GVHD should be considered relevant for these patients.…”

“…6 It has been previously shown that the magnetic-activated cell separation technique is highly effective for clinical-scale preparation of CD34+ progenitor cells collected from leukapheresis products. [7][8][9] Large-scale preparations of purified CD34+ cells from bone marrow (BM) products have been used and reported only occasionally, as the expected cell loss has been considered too high to safely perform HSCT, particularly in adult patients. Children with IMSD have relatively low weights and often receive BM from an unrelated donor.…”

Unrelated peripheral blood stem cell transplantation with ‘megadoses’ of purified CD34+ cells in three children with refractory severe aplastic anemia

“…Presently magnetic cell sorting of peripheral blood CD34 + cells has been shown to be the most effective selection procedure in recovering high numbers of stem cells with high purity and low T cell numbers and therefore was used in our patients. [6][7][8] Donors were provided by the 'Deutsche Knochenmarsspenderdatei' (DKMS) (Tübingen, Germany). Two cell separations after mobilization with G-CSF yielded sufficient numbers of progenitors.…”

“…[6][7][8] In the other two cases CD34 + cells were selected using the CliniMACS-system (Miltenyi Biotec). Apheresis products were diluted (1:1) in buffer solution consisting of phosphate-buffered saline (PBS) w/o Ca/Mg (Gibco, Paisley, UK), 5 mm EDTA and 5% human albumin at a final concentration of 0.8% (Immuno, Vienna, Austria) and centrifuged for 15 min at 350 g for removal of platelets.…”

“…Magnetic cell sorting (MACS) was performed to purify the peripheral blood mononuclear cells with adequate recovery of CD34 + cells. 6 We present the clinical, hematopoietic and immunologic data of three children who underwent transplantation with 'megadoses' of unrelated purified CD34 + cells for the treatment of refractory SAA.…”