title: Counter-flow elutriation of clinical peripheral blood mononuclear cell concentrates for the production of dendritic and T cell therapies.
abstract: BACKGROUND
  Peripheral blood mononuclear cells (PBMC) concentrates collected by apheresis are frequently used as starting material for cellular therapies, but the cell of interest must often be isolated prior to initiating manufacturing.
  
  
  METHODS
  The results of enriching 59 clinical PBMC concentrates for monocytes or lymphocytes from patients with solid tumors or multiple myeloma using a commercial closed system semi-automated counter-flow elutriation instrument (Elutra, Terumo BCT) were evaluated for quality and consistency. Elutriated monocytes (n = 35) were used to manufacture autologous dendritic cells and elutriated lymphocytes (n = 24) were used manufacture autologous T cell therapies. Elutriated monocytes with >10% neutrophils were subjected to density gradient sedimentation to reduce neutrophil contamination and elutriated lymphocytes to RBC lysis.
  
  
  RESULTS
  Elutriation separated the PBMC concentrates into 5 fractions. Almost all of the lymphocytes, platelets and red cells were found in fractions 1 and 2; in contrast, most of the monocytes, 88.6 ± 43.0%, and neutrophils, 74.8 ± 64.3%, were in fraction 5. In addition, elutriation of 6 PBMCs resulted in relatively large quantities of monocytes in fractions 1 or 2. These 6 PBMCs contained greater quantities of monocytes than the other 53 PBMCs. Among fraction 5 isolates 38 of 59 contained >10% neutrophils. High neutrophil content of fraction 5 was associated with greater quantities of neutrophils in the PBMC concentrate. Following density gradient separation the neutrophil counts fell to 3.6 ± 3.4% (all products contained <10% neutrophils). Following red cell lysis of the elutriated lymphocyte fraction the lymphocyte recovery was 86.7 ± 24.0% and 34.3 ± 37.4% of red blood cells remained.
  
  
  CONCLUSIONS
  Elutriation was consistent and effective for isolating monocytes and lymphocytes from PBMC concentrates for manufacturing clinical cell therapies, but further processing is often required.
authors.forename: David F
authors.initials: DF
authors.lastname: Stroncek
authors.forename: Vicki
authors.initials: V
authors.lastname: Fellowes
authors.forename: Chauha
authors.initials: C
authors.lastname: Pham
authors.forename: Hanh
authors.initials: H
authors.lastname: Khuu
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Fowler
authors.forename: Lauren V
authors.initials: LV
authors.lastname: Wood
authors.forename: Marianna
authors.initials: M
authors.lastname: Sabatino
mesh_terms: D002469:Cell Separation; D064987:Cell- and Tissue-Based Therapy; D003713:Dendritic Cells; D006801:Humans; D008297:Male; D009000:Monocytes; D009101:Multiple Myeloma / Q000628:therapy; D011471:Prostatic Neoplasms / Q000628:therapy; D013601:T-Lymphocytes