Clinical Applications of CD34+ Cell‐selected Peripheral Blood Stem Cells

Abstract

Peripheral blood stem cells (PBSC) are increasingly used for stem cell transplantation after high dose chemotherapy. CD34+ cell selection has also been done for use in autologous transplantation studies Bone marrow (BM) may contain tumor cells at the time of harvesting, and on re-infusion, these cells could contribute to a subsequent relapse. Similarly, tumor cell contamination of PBSC collections has been found in a number of studies. Therefore, purging contaminating tumor cells may prevent cases of relapse. As most tumor cell types do not express CD34 antigen, one of the most widespread applications of CD34+ cell selection is likely to be in tumor cell purging. Similarly, CD34+ cell selection has aided allogeneic transplantation studies. Acute graft-versus-host disease (aGVHD) is a major cause of morbidity and mortality in cases of allogeneic transplantation. As aGVHD is mediated by donor T cells, removal of T cells from the graft by CD34+ cell selection may ensure prophylaxis against aGVHD. Further, high-dose immunosuppression followed by CD34+ cell-selected stem cell rescue is theoretically reasonable as a therapeutic tool for patients with autoimmune disease resistant to conventional therapy. However, patients given T cell-depleted transplantation have an increased risk of opportunistic infection as well as malignancies related to immunosuppression; therefore, close monitoring is warranted. We describe here clinical applications of CD34+ cell-selected PBSC for a variety of diseases, with special emphasis on the efficacy as well as drawbacks of this novel technique.

Blood Dendritic Cells Suppress NK Cell Function and Increase the Risk of Leukemia Relapse after Hematopoietic Cell Transplantation

“…Second, the data suggest that DC depletion from the donor graft should be considered in haploidentical HCT for leukemia, as blood DCs may not only inhibit NK cells, but also contain some circulating tolerogenic DC subsets (59, 60). DC depletion can be accomplished by directly removing DCs from the hematopoietic graft, or indirectly through positive selection of stem cells using markers such as CD133 or CD34 which are commonly used in the clinic (61). …”

HIV-Induced Abnormalities in Myelopoiesis and their Recovery Following Antiretroviral Therapy

“…Sampling from peripheral blood is less traumatic for the patient and more suitable for longitudinal studies. The widespread use of blood-derived CD34+ cells in the clinical setting [12][13][14] suggests that these cells are functionally equivalent to their bone marrow counterparts, although to date this has been not clearly demonstrated in the setting of HIV infection.…”

Immunomagnetic Cell Selection Performed for HLA Haploidentical Transplants with the CliniMACS Device: Effect of Additional Platelet Removal on CD34+Cell Recovery

“…Currently, immunomagnetic cell selection has been proved to be the safest and most effective technology approved for clinical practice (10,11). The CliniMACS (Miltenyi Biotec) cell selection device is an automated and sterile system that allows large-scale magnetic cell selection of CD34 ϩ cells (12)(13)(14). Many factors may potentially influence the ICS outcome (15); in particular, platelets are suggested to affect the CD34 ϩ cell recovery and purity negatively through a possible aspecific interference on antibody binding to the stem cells to be selected.…”