Eosinophil granule proteins in cardiopulmonary bypass with and without heparin coating

Extracorporeal circulation with exposure of blood to foreign surfaces causes activation of different defense systems, eg, white cells. Several potent mediators are released into plasma, capable of causing harmful effects to different organs, contributing to postoperative morbidity after operations using cardiopulmonary bypass. The eosinophil granulocyte has not previously been investigated in this respect. We studied two of its activation products, eosinophil cationic protein and eosinophil protein X in coronary bypass patients. In 17 control patients, plasma levels of eosinophil cationic protein and eosinophil protein X increased considerably during cardiopulmonary bypass. In 19 patients with heparin-coated cardiopulmonary bypass equipment the levels were significantly reduced, indicating improved biocompatibility of the cardiopulmonary bypass circuit. The heparin-coated surface causes less activation of eosinophils; also, released eosinophil cationic protein is bound to the heparinized surface.