Depletion of αβ T cells for a haploidentical hematopoietic stem cell transplantation in children.

A consistent and reproducible depletion technique is crucial for the successful transplantation of an ex vivo depleted graft. Our aim was to evaluate the efficacy of an ex vivo technique for depletion of αβ T cells using a biotinylated anti-TCRαβ monoclonal antibody, which was performed by one clinical nurse specialist. Between 2012 and 2017, 119 depletion procedures from 216 apheresis using the anti-TCRαβ monoclonal antibody were performed on 105 pediatric patients. The median log depletion of αβ T cells was 4.0 (range, 2.5-5.0). The median recovery rates of CD34 , NK, and γδ T cells were 90.4%, 74.9%, and 75.9%, respectively. The efficacy of depletion of αβ T cells significantly improved over time and the duration of the depletion procedure significantly decreased over time. Our study demonstrated that this procedure for depletion of αβ T cells by skilled staff is highly effective at depleting target cells and obtaining CD34+ progenitor cells.