title: Variable leukocyte composition of red blood cell concentrates prepared in top-bottom systems: possible implications for pre-transplant blood transfusion.
abstract: OBJECTIVE
  The beneficial effect of blood transfusion on kidney graft survival requires the presence of leukocytes in the transfusate, but a minimal dose has not been defined, nor has the role of individual leukocyte subsets been investigated. In the Netherlands, a standard pre-transplant blood transfusion consists of a buffy coat (BC)-depleted red blood cell concentrate (RBCC) containing a maximum of 1.2x10(9) residual leukocytes per unit. However, leukocyte subset composition is not standardized.
  
  
  METHODS
  Using FACS analysis, this study compared the residual leukocyte composition of RBCCs produced by Compomat((R)) and Optipress((R)), two currently used top-bottom systems.
  
  
  RESULTS
  While the total leukocyte content of the RBCCs was equivalent in both press types (0.5x10(9)), the percentage of mononuclear cells (lymphocytes and monocytes) was significantly higher in the Compomat as compared with the Optipress system (p < 0. 0001), resulting in significantly higher numbers of transfused T cells, B cells, HLA-DR-positive cells, NK cells and stem cells.
  
  
  CONCLUSIONS
  The leukocyte composition of a pre-transplant blood transfusion depends on the BC depletion method used; this might differentially affect the tolerizing or immunizing potential of a pre-transplant blood transfusion.
authors.affiliation: Department of Immunobiology, Central Laboratory of the Blood Transfusion Service, Amsterdam, The Netherlands. staphanie.weinreich@vsn.nl
authors.forename: S S
authors.initials: SS
authors.lastname: Weinreich
authors.forename: E B
authors.initials: EB
authors.lastname: Remmerswaal
authors.forename: R
authors.initials: R
authors.lastname: Laport
authors.forename: D J
authors.initials: DJ
authors.lastname: van Rhenen
authors.forename: E
authors.initials: E
authors.lastname: Rombout-Sastrienkova
authors.forename: C T
authors.initials: CT
authors.lastname: Smit Sibinga
authors.forename: H
authors.initials: H
authors.lastname: Vrielink
authors.forename: C J
authors.initials: CJ
authors.lastname: Boog
mesh_terms: D001772:Blood Cell Count; D001781:Blood Component Removal / Q000295:instrumentation / Q000379:methods*; D002469:Cell Separation / Q000295:instrumentation*; D002498:Centrifugation; D017707:Erythrocyte Transfusion / Q000379:methods* / Q000592:standards; D005434:Flow Cytometry; D006801:Humans; D016030:Kidney Transplantation / Q000379:methods / Q000592:standards; D007958:Leukocyte Count; D007962:Leukocytes; D007963:Leukocytes, Mononuclear / Q000166:cytology