A CD34+ Cell Enrichment Protocol of Hematopoietic Stem Cells in a Well-Established Quality Management System

Abstract

Allogeneic stem cell transplantation applications have improved tremendously over the past quarter of a century. The use of new immunosuppressive protocols and elimination of T cells by CD34+ cell enrichment or T cell depletion on apheresis products increases the chance of using partially matched or haploidentical grafts. This is without increasing the risk of graft-versus-host disease, which is observed as a major complication of hematopoietic stem cell transplantation. The aim of this protocol is to evaluate the results obtained from 6 different process cycles performed on 6 different days. We used the CliniMACS Plus system located in our Cell and Tissue Manufacturing Center Quality Control Unit which is already calibrated as a class D room and includes a class A microbiological safety cabinet inside. The average purity of the end products was 95.66%, excluding only one end product which was 70%; this was higher than the values in current studies in the field. Superior to the reported studies, the CD3 quantity in each end product was below the dedicated thresholds. BactecTM FX40 blood culture system test results were detected as negative for each end product. Endotoxin testing suggested the absence of endotoxin within the products. The consistent outcomes obtained from these 6 different process cycles confirmed that the CliniMACS® Plus process cycles performed in accordance with our well-defined quality management system procedure is sufficient for the routine application of high-quality and safe CD34+ enrichment processes within our clean room area.