Cardiopulmonary bypass causes release of leukocyte proteinase-3.

Activation of leukocytes is an important but not fully understood event during cardiopulmonary bypass. Leukocyte proteinase-3, also known as neutrophil proteinase-4, was analysed in plasma by means of an enzyme-linked immunosorbent assay after heart surgery with extracorporeal circulation. The levels of proteinase-3 increased ninefold after surgery compared with preoperative values. Over the following days, the levels declined but were still elevated on the second postoperative day. The levels of proteinase-3 3 h after heart surgery were correlated to the time on cardiopulmonary bypass. Proteinase-3 is involved in the inflammatory process seen after extracorporeal circulation.