Formation of C 8 - CI - Inhibitor , Kallikrein - CI - Inhibitor , and Plasmin - a 2 - Plasmin - Inhibitor Complexes During Cardiopulmonary Bypass

Stimulation of platelets and neutrophils occurs during clinical cardiopulmonary bypass. We investigated whether the classical complement. contact. or fibrinolytic pathways are activated as potential sources of neutrophil agonists. Using enzyme-linked immunosorbent “sandwich” assays specific for Cl 8-C1 -and kallikrein-C1 -inhibitor complexes respectively. we found that there was a modest increase in plasma levels of each complex after clinical cardiopulmonary bypass was completed. The increased concentration of enzyme-inhibitor complexes reverted to baseline within 24 hours. Since these complexes are cleared in vivo. we measured their formation by assaying their plasma levels