Objective: CD34+ is an immunophenotype of hematopoietic stem cells/progenitors. CD34+ cells selection in vitro may deplete T-cells 4-5 logs and tumor cells 3-4 logs. It will benefit to mismatched related donor allo-transplantation and autologous transplantation of tumor diseases.
Methods: 19 patients aged 29 (5-52) years were treated by allo- (n = 5) or auto-PB CD34+ cells transplantation (n = 14). Grafts from fifteen patients with various disorders (3 lymphomas, 6 multiple myelomas, 2 SLE, 1 Sjogren's syndrome, 2 breast cancer and 1 medulloblastoma) and five haploidentical donors for leukemia patients (1 ALL-CR2, 2 AML-rel, 1 CML-CP and 1 MDS-RAEB) were isolated using magnetic-activated cell sorting (CliniMACS, Milteny Biotech, Germany).
Results: After separation, purity of CD34+ cells was > 97%. Depletion of CD34 negative cells was extensive: CD3+ 2.6-4.6 logs, CD4+ > 5 logs, CD8+ 4.6-> 5 logs, and CD19+ 1.2-3.1 logs. 19 patients who received selected CD34+ cells transplantation (CD34+ CT) were followed up for 11(1-20) months. Overall survival(OS) was 13/19 (68.4%) cases. 1/5 patients with haploidentical transplant had disease free survival for 19 months. 12/14(85.7%) auto-CD34+ CT achieved overall survival(OS).
Conclusion: Selected CD34+ cells transplantation significantly decreases the incidence of > II GVHD and depletes tumor cell contamination. This approach may be useful to haploidentical or unrelated donor transplantation. It also benefits autologous transplant in various tumor disorders.