title: Time for new concepts about measurement of complement activation by cardiopulmonary bypass?
abstract: Fifty-one patients admitted for routine coronary bypass operations were randomized to cardiopulmonary bypass with a membrane oxygenator (Capiox) or a bubbler (Polystan or William Harvey). Complement activation was measured using enzyme immunoassays for concentrations of C3 activation products and the terminal complement complex. From 5.8 to 8.1 arbitrary units (AU)/mL (medians), the plasma concentrations of C3 activation products increased by 119.9 AU/mL (Capiox), 124.6 AU/mL (Polystan), and 79.5 AU/mL (William Harvey) to a peak at closure of the sternum (not significant when related to baseline concentrations). The increase in C3 activation products and baseline C3 activation were linearly correlated (R2 = 0.30; p less than 0.0001). From 5.5 to 6.1 AU/mL, the plasma terminal complement complex concentrations increased by 45.2 AU/mL (Capiox), 15.4 AU/mL (Polystan), and 17.4 AU/mL (William Harvey) to a peak before termination of cardiopulmonary bypass. Maximal terminal (C5-C9) activation was significantly higher in the membrane oxygenator group (p less than 0.0001) and showed no relationship to C3 activation. Measurement of C3 activation only gives no information about C5-C9 activation. At present, terminal complement complex quantitation is probably the best index of C5-C9 activation during cardiopulmonary bypass.
authors.affiliation: Institute for Experimental Medical Research, Ullevaal Hospital, Oslo, Norway.
authors.forename: V
authors.initials: V
authors.lastname: Videm
authors.forename: E
authors.initials: E
authors.lastname: Fosse
authors.forename: T E
authors.initials: TE
authors.lastname: Mollnes
authors.forename: P
authors.initials: P
authors.lastname: Garred
authors.forename: J L
authors.initials: JL
authors.lastname: Svennevig
mesh_terms: D002315:Cardiopulmonary Bypass; D003167:Complement Activation; D003176:Complement C3 / Q000276:immunology*; D003165:Complement System Proteins / Q000032:analysis / Q000276:immunology*; D001026:Coronary Artery Bypass; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010106:Oxygenators; D010107:Oxygenators, Membrane
chemical_list: D003176:Complement C3; D003165:Complement System Proteins