title: Activation of the complement system by different autologous transfusion devices: an in vitro study.
abstract: BACKGROUND
  The aim of the present investigation was to study whether autologous transfusion devices activate the complement system and whether complement-activated blood is more vulnerable to further activation during processing.
  
  
  METHODS
  Forty-eight blood units were randomized to be processed by one of three different salvage systems: Group 1 underwent whole blood filtration (hemofiltration) (n=16); Group 2 underwent continuous processing, saline washing, and centrifugation (CATS, Fresenius AG ) (n=16); and Group 3 underwent saline washing and centrifugation (Cell-Saver, Haemonetics Corp.) (n=16). Eight blood units for each system were activated with cobra venom factor (CVF) at a concentration of 0.2 U per mL whole blood before processing. C activation was studied by determinations of C4d, Bb, C3a, and SC5b-9. Samples were drawn from whole blood, processed blood, and the waste bags.
  
  
  RESULTS
  The concentrations of Bb, C3a, and SC5b-9 in whole blood after activation with CVF were significantly elevated compared to blood that was not activated (p < 0.01). Processed blood from hemofiltration contained significantly higher levels of complement-split products than techniques that use washing and centrifugation. The concentrations of SC5b-9 in blood processed by hemofiltration were higher in the experiments with CVF activation (p < 0.05).
  
  
  CONCLUSIONS
  The tested autologous transfusion systems did not themselves activate the complement system, and complement-activated blood was not more vulnerable to further activation during processing. A blood-salvaging technique that used washing and centrifugation reduced elevated concentrations of complement-split products, whereas hemofiltration did not.
authors.affiliation: Department of Anesthesiology and Intensive Care, Sahlgrenska University Hospital/Ostra, Göteburg, Sweden. tylman@mailer.mednet.gu.se
authors.forename: Maria
authors.initials: M
authors.lastname: Tylman
authors.forename: Jan Peter
authors.initials: JP
authors.lastname: Bengtson
authors.forename: Anders
authors.initials: A
authors.lastname: Bengtsson
mesh_terms: D001804:Blood Transfusion, Autologous / Q000295:instrumentation*; D002498:Centrifugation; D003167:Complement Activation; D051561:Complement C3 Convertase, Alternative Pathway; D015926:Complement C3a / Q000032:analysis; D003179:Complement C3b; D003181:Complement C4; D015935:Complement C4b; D015938:Complement Membrane Attack Complex; D003165:Complement System Proteins; D004546:Elapid Venoms / Q000494:pharmacology; D005374:Filtration; D006023:Glycoproteins / Q000097:blood; D006801:Humans; D066298:In Vitro Techniques; D010446:Peptide Fragments / Q000097:blood
chemical_list: D003181:Complement C4; D015938:Complement Membrane Attack Complex; D004546:Elapid Venoms; D006023:Glycoproteins; D010446:Peptide Fragments; C047610:SC5b-9 protein complex; C016310:cobra venom factor; D015926:Complement C3a; D003179:Complement C3b; D015935:Complement C4b; C032261:complement C4d; D003165:Complement System Proteins; D051561:Complement C3 Convertase, Alternative Pathway