Platelet dysfunction contributes to haemostatic defects, possibly leading to bleeding complications. We hypothesised that liver transplantation and liver resection, together with portal clamping time, might be a potential stimulus for platelet activation. Therefore, we determined the expression of platelet GPIIb/IIIa and P-selectin, representing important platelet activation markers, and the thrombopoietin (TPO) serum level after transplantation and resection. Twenty patients [ten that had undergone orthotopic liver transplantation (OLT), ten with liver resection (LRX)] were included in the study. From sequential venous blood samples, surface expression of GPIIb/IIIa and P-selectin was quantified by flow cytometry, and TPO serum levels were determined by ELISA. Baseline GPIIb/IIIa receptor expression on circulating platelets was significantly reduced in the OLT group compared to the LRX group and healthy volunteers. GPIIb/IIIa expression after activation with TRAP-6 increased significantly ( P
