Depletion of αβ+ T and B Cells Using the CliniMACS Prodigy: Results of 10 Graft-Processing Procedures from Haploidentical Donors

Abstract

Background: Depletion of TCRαβ+ T cells and B cells with the CliniMACS Plus® has been used for haploidentical hematopoietic stem cell transplantation for a decade. The depletion procedure is time and labour demanding and with variable reported efficiencies. Recently, an automated procedure was launched for the CliniMACS Prodigy® (Miltenyi Biotec) but reported data are scarce. Here, we report the results of the first ten TCRαβ+ and B cell depletion procedures for clinical use performed at our centre. Materials and Methods: All transplants were from a parent to a child. Collection of peripheral blood stem cells was performed after filgrastim mobilisation by use of the Spectra Optia® (TerumoBCT) set on the MNC program. Because of insufficient hematopoietic stem cell mobilisation, 1 donor received additional plerixafor. Results: We performed ten uncomplicated processes with the CliniMACS Prodigy. We found the results of the depletion procedures satisfactory with a median log reduction of TCRαβ+ cells of –4.21 (range –3.98 to –4.74), resulting in a median number of TCRαβ+ cells in the depleted product of 28.6 × 10³/kg recipient weight (range 14.9–69.7 × 10³/kg). The median CD34 recovery was 83% (range 70–100). To achieve a sufficient number of CD34+ cells, we performed an additional CD34+ enrichment procedure using the CliniMACS Plus for 3 patients. The B cell depletion was slightly less efficient with a median log reduction of –3.72 (range –2.83 to –4.20). Conclusion: Overall, we found the TCRαβ and CD19 depletion procedure on the CliniMACS Prodigy easy to handle and reliable, providing reproducible good results.