Sequential CD34+ and CD4+ Cell Selection from Leukapheresis Components

Abstract

We tested the feasibility of sequential selection of CD34+ and CD4+ cell-enriched fractions from aliquots of five autologous leukapheresis components. CD34+ cells were seleced from a median 8.0 x 10⁸ mononuclear cells using the CellPro CEPRATE LC cell separation system. All cells in the CD34-depleted fraction (median 4.8 x 10⁸, range 0.6-10.0 x 10⁸) were then incubated with the appropriate antibodies for CD4+ cell selection and passed through a second LC column. Median target cell purities of the CD34+ cell-enriched fraction and CD4+ cell-enriched fraction were 90.5% and 86.0%, respectively. This study demonstrates that high purity CD34+ and CD4+ cell-enriched fractions can be isolated sequentially from leukapheresis components. In addition, CD8+ lymphocytes, implicated in graft-versus-host disease, were depleted in the course of both positive selection procedures. This approach could decrease the number of donor procedures by providing separate CD34+-enriched and CD4+-enriched populations for allogeneic peripheral blood progenitor cell transplantation and subsequent donor lymphocyte infusion from the same leukapheresis component.