title: Reduction of biological response modifiers in the supernatant of washed paediatric red blood cells.
abstract: BACKGROUND
  Washing of red blood cells (RBC) can reduce unwanted biological response modifiers (BRMs) that can mediate transfusion complications in infants. The aim of this study was to examine the in vitro quality and the changes in BRMs following washing in paediatric RBC units.
  
  
  METHODS
  A pool and split design was used to prepare RBC (either 1 or 4 days old; n = 26 pairs). One unit was washed with 0·9% saline by centrifugation and then resuspended in SAG-M, while the other remained unwashed. Each RBC unit was divided to produce four units of paediatric-sized components. Samples were taken after 3 h and subsequently on days 1, 2, 7 and 14 post-wash.
  
  
  RESULTS
  Washing of RBC resulted in some red cell loss, with a minor increase in haemolysis. Washing effectively reduced supernatant potassium and IgA, as well as cytokines and complement proteins. RBC microparticles were significantly reduced in RBC washed at 1, but not 4 days post-collection. Incubation with supernatant from unwashed but not washed RBC led to endothelial cell activation, with increased cell surface expression of CD62E (E-selectin) and CD106 (VCAM).
  
  
  CONCLUSIONS
  Although washing affected some aspects of the in vitro quality of RBC, it effectively reduced the concentration and activity of BRMs in the supernatant of RBC. Such a reduction may be clinically beneficial in selected patient groups.
authors.affiliation: Research and Development, Australian Red Cross Blood Service, Sydney, NSW, Australia.
authors.forename: Y S
authors.initials: YS
authors.lastname: Loh
authors.affiliation: Research and Development, Australian Red Cross Blood Service, Sydney, NSW, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Tan
authors.affiliation: Research and Development, Australian Red Cross Blood Service, Sydney, NSW, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Kwok
authors.affiliation: School of Paediatrics and Reproductive Health, The Robinson Institute, University of Adelaide, Adelaide, NSW, Australia.
authors.forename: M J
authors.initials: MJ
authors.lastname: Stark
authors.affiliation: Research and Development, Australian Red Cross Blood Service, Sydney, NSW, Australia.
authors.forename: D C
authors.initials: DC
authors.lastname: Marks
mesh_terms: D058731:Blood Safety; D055252:Cell-Derived Microparticles / Q000502:physiology; D016238:Cytapheresis / Q000379:methods*; D019040:E-Selectin / Q000378:metabolism; D017707:Erythrocyte Transfusion; D061307:Human Umbilical Vein Endothelial Cells / Q000502:physiology; D006801:Humans; D007155:Immunologic Factors / Q000302:isolation & purification*; D010372:Pediatrics
chemical_list: D019040:E-Selectin; D007155:Immunologic Factors; C546936:SELE protein, human
keywords: blood processing; cytokine; red cell components; transfusion - paediatrics