Enrichment of peripheral blood CD34+ cells for transplantation using a fully automated immunomagnetic cell selection system and a novel octapeptide releasing agent

Abstract

Summary:Positive selection of CD34 ؉ cells is being increasingly performed to support hematological reconstitution following high-dose and dose-intensive chemotherapy and to reduce the non-target cell content of transplants. The present study was designed to evaluate the performance of an immunomagnetic cell selection system, including comparison of enzyme and peptide releasing agents and of semi-automated and fully automated selection systems. A total of 74 immunomagnetic CD34 ؉ cell selection procedures were performed involving 55 subjects, the majority of whom had hematologic malignancies. Median CD34 ؉ cell purity with a newly developed specific octapeptide releasing agent (98.5%; 81.0-99.0%) was significantly higher (P = 0.002) than that with chymopapain (85.8%; 28.1-99.7%). No significant differences were observed between semi-automated and fully automated systems in CD34 ؉ cell purity or yield or time to WBC or platelet recovery. Immunomagnetic selection was found to provide highly purified populations of CD34 ؉ cells in sufficient numbers for use in transplantation procedures. CD34 ؉ cell transplants supported rapid and reliable hematologic reconstitution. Use of a fully automated system markedly reduced the time and labor required for immunomagnetic selection, potentially affording more standardized and reproducible positive selection of CD34 ؉ cells.

Transplantation of CD34+ peripheral blood cells selected using a fully automated immunomagnetic system in patients with high-risk breast cancer: results of a prospective randomized multicenter clinical trial

“…The procedural steps performed by the fully automated system, which have been previously described, 33 are shown in Figure 2. Briefly, cells were incubated with 2.5 mg of anti-CD34 MoAb in a total volume of 100 ml for 15 min at ambient temperature with occasional gentle mixing.…”

Autologous bone marrow transplantation in the treatment of refractory systemic sclerosis: early results from a French multicentre phase I–II study

“…CD34 + cell selection. CD34 + cells were selected using an anti‐CD34 monoclonal antibody (mAb), immunomagnetic bead technique (Nexel Isolex ® 300i Stem Cell Collection System) (Marolleau et al , 1999). The CD34 + fraction was cryopreserved and reinfused into the recipient after thawing and washing.…”

Detection of Epithelial Cells in Hematopoietic Organs of Patients with Breast Cancer

“…They demonstrate feasibility, with all three types of clinically tested devices being able to enrich for CD34+ cells, and patients recovering neutrophils and platelets in delays that appear to be similar or slightly longer than for patients receiving unmanipulated stem and progenitor cell support. The use of a CD34+ cell selection device results in a net loss of progenitors (CD34+ cells) that tends to be lower with the most recent of these devices [40, 41, 42], and is also lower when processing aphereses than when processing bone marrow grafts. This is a problem in ‘poor mobilizers’, for which the technique may be unsuitable; one may argue, however, that poor mobilizers are often patients for whom the disease is not in complete remission, and are thus unlikely to benefit from HDCT, even when reinfused with a purged autologous graft.…”

“…The first one [41]examined the consequence of reinfusing CD34+ cell-selected marrow cells by comparison with an unmanipulated graft: the use of the Ceprate ® device resulted in a decreased morbidity associated with the use of a cryoprotectant, DMSO, but patient numbers were too small to look at the consequences in terms of overall or disease-free survival. The second one [6, 42]addressed the same question, but for patients receiving aphereses rather than autologous bone marrow as the hematopoietic support; in addition, tumor purging was achieved through the use of a different CD34+ cell-selection device, the Isolex ® device.…”