Ενεργοποίηση των μορίων προσκόλλησης (Adhesion molecules) των λευκοκυττάρων κατά την εξωσωματική κυκλοφορία

Abstract

Backround: Extracorporeal circulation produces a systemic imflammatory response in humans, activating the complement system, the intrinsic and extrinsic coagulation pathways, the fibrinolytic system, monocytes, platelets, endothelial cells and neutrophils. Part of this complex interaction entails the upregulation of leucocyte adhesion molecules. Hypothesis: We hypothesized that leucocytes are activated during extracorporeal circulation. CD11a/DC18 and CD11b/CD18 are upregulated and their upregulation will be measured with flow cytometry. Materials and Methods: This study included 40 adult patients that underwent coronary bypass graft operations with the use of extracorporeal circulation. These patients were carefully selected when it comes to risk factors, so the patient population was as homogenous as possible.Blood samples were collected at 7 descrete phases of the perioperative period. These blood samples were processed with fluorescent monoclonal antibodies against CD11a/CD18 and CD11b/CD18 and were afterwards analyzed with flow cytometry , measuring the mean channel fluorescence of the activated leucocytes. Results were analyzed using the Lysis II statistical software. Results: The adhesion molecules were upregulated. CD11a/CD18 was mostly upregulated after protamine administration. On the other hand, CD11b/CD18 was upregulated at an early phase and also later on after protamine administration.Both agents’ levels returned back to preoperative baseline values, 24hrs after the operation.None of the study population of patients suffered any significant complication, including, stroke, myocardial infarction or death. Discussion: This study demonstrated that during extracorporeal circulation, there is activation of adhesion molecules CD11a/CD18 and CD11b/CD18. This agrees with the findings of other investigators.The significance of this upregulation is still uncertain.The role of protamine administration seems to be of importance. It upregulates significantly both adhesion molecules and possibly can lead to pulmonary dysfunction. The activation of these two molecules correlates with the activation of the complement system with the resultant production of several lytic or inhibitory enzymes. ...........................................................................................................................