title: Depletion of T-cell receptor alpha/beta and CD19 positive cells from apheresis products with the CliniMACS device.
abstract: OBJECTIVE
  The CliniMACS device (Miltenyi Biotec, Bergisch Gladbach, Germany) was used for depletion of T-cell receptor alpha/beta positive (TCRαβ(+)) and CD19 positive (CD19(+)) cells from apheresis products.
  
  
  METHODS
  Investigators performed 102 separations. Apheresis products with a median 5.8 (minimum to maximum, 1.2-10.4) × 10(10) mononuclear cells were used with a median 358 (92-1432) × 10(6) CD34(+) cells. There were 24.8% (6.1-45.7%) median TCRαβ(+) cells and 4.4% (1.2-11.7%) median B cells in the apheresis product.
  
  
  RESULTS
  After depletion, a median 0.00097% (0.00025-0.0048%) of TCRαβ(+) cells could be detected, and B cells, as determined as CD20(+) cells, were reduced to 0.0072% (0.0008-0.072%). TCRαβ(+) cells were depleted by log 4.7 (3.8-5.5), and B cells were depleted by log 4.1 (3.0-4.7). Recovery of mononuclear cells was 55% (33-77%), and recovery of CD34(+) cells was 73% (43-98%). Recovery of CD56(+)/3(-) natural killer cells was 80% (35-142%), recovery of TCR gamma/delta positive (TCRγδ(+)) T cells was 83% (39-173%) and recovery of CD14(+) cells was 79% (22-141%). Viability of cells was 98% (93-99%) after separation (all values median).
  
  
  CONCLUSIONS
  Profound depletion of TCRαβ(+) T cells can be achieved with the CliniMACS system. Recovery of CD34(+) stem cells is in the same range than after CD34(+) enrichment and CD3/CD19 depletion. Transplantation with >4 × 10(6) CD34(+) cells/kg can be performed for every patient with 1-5 × 10(4) TCRαβ(+) cells/kg and about 5-10 × 10(6) TCRγδ(+) cells/kg with two rounds of apheresis.
authors.affiliation: Children's Hospital, University Hospital Tübingen, Tübingen, Germany. Michael.Schumm@med.uni-tuebingen.de
authors.forename: Michael
authors.initials: M
authors.lastname: Schumm
authors.forename: Peter
authors.initials: P
authors.lastname: Lang
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bethge
authors.forename: Christoph
authors.initials: C
authors.lastname: Faul
authors.forename: Tobias
authors.initials: T
authors.lastname: Feuchtinger
authors.forename: Matthias
authors.initials: M
authors.lastname: Pfeiffer
authors.forename: Wichard
authors.initials: W
authors.lastname: Vogel
authors.forename: Volker
authors.initials: V
authors.lastname: Huppert
authors.forename: Rupert
authors.initials: R
authors.lastname: Handgretinger
mesh_terms: D018941:Antigens, CD19 / Q000378:metabolism; D018951:Antigens, CD20 / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D001781:Blood Component Removal; D002470:Cell Survival; D005240:Feasibility Studies; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D008212:Lymphocyte Depletion; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism*
chemical_list: D018941:Antigens, CD19; D018951:Antigens, CD20; D016693:Receptors, Antigen, T-Cell, alpha-beta
keywords: B cell; CliniMACS; T cell; allogeneic transplantation; depletion; flow cytometry