Heparin-protamine complexes and C-reactive protein induce activation of the classical complement pathway: studies in patients undergoing cardiac surgery and in vitro

Autor: P, Bruins, H, te Velthuis, A J, Eerenberg-Belmer, A P, Yazdanbakhsh, E M, de Beaumont, L, Eijsman, A, Trouwborst, C E, Hack
Rok vydání: 2000
Předmět:
Zdroj: Thrombosis and haemostasis. 84(2)
ISSN: 0340-6245
Popis: The administration of protamine to patients undergoing cardiopulmonary bypass (CPB) to neutralize heparin and to reduce the risk of bleeding, induces activation of the classical complement pathway mainly by heparin-protamine complexes. We investigated whether C-reactive protein (CRP) contributes to protamine-induced complement activation. In 24 patients during myocardial revascularization, we measured complement, CRP, and complement-CRP complexes, reflecting CRP-mediated complement activation in vivo. We also incubated plasma from healthy volunteers and patients with heparin and protamine in vitro to study CRP-mediated complement activation. During CPB, CRP levels remained unchanged while C3 activation products increased. C4 activation occurred after protamine administration. CRP-complement complexes increased at the end of CPB and upon protamine administration. Incubation of plasma with heparin and protamine in vitro generated complement-CRP complexes, which was blocked by phosphorylcholine and stimulated by exogenous CRP. C4d-CRP complex formation after protamine administration correlated clinically with the incidence of postoperative arrhythmia. Protamine administration during cardiac surgery induces complement activation which in part is CRP-dependent, and correlates with postoperative arrhythmia.
Databáze: OpenAIRE