Becker Thomas, Jüttner Björn, Elsner Holger-Andreas, Meyer zu Vilsendorf Andreas, Bornscheuer Albrecht, Nashan Björn, Brandl Michael, Klempnauer Jürgen, Piepenbrock Siegfried, Scheinichen Dirk
Department of Visceral and Transplant Surgery, Hanover Medical School, Carl-Neuberg-Strasse 1, 30625 Hanover, Germany.
Transpl Int. 2004 Sep;17(8):442-8. doi: 10.1007/s00147-004-0747-y. Epub 2004 Aug 17.
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<0.001) in the LRX group but not in the OLT group. P-selectin expression after TRAP-6 stimulation increased significantly ( P<0.001) in the LRX group, being comparable to that in healthy volunteers, whereas only a very low increase in the OLT group was found. In the OLT group, TPO serum levels were in the lower normal range and rose above the upper limit of normal values 24 h after reperfusion. These data indicate that neither liver transplantation nor liver resection influences GPIIb/IIIa and P-selectin expression on circulating platelets. There was a lack of expression in cirrhotic patients and unimpaired baseline expression and functional reserve in non-cirrhotic liver-resection patients. After liver transplantation, increasing serum TPO levels, which indicated a recovering graft function, resulted in rising peripheral platelet counts.
血小板功能障碍会导致止血缺陷，可能引发出血并发症。我们推测肝移植、肝切除以及门静脉阻断时间可能是血小板激活的潜在刺激因素。因此，我们测定了代表重要血小板激活标志物的血小板糖蛋白IIb/IIIa（GPIIb/IIIa）和P-选择素的表达，以及移植和切除术后的血小板生成素（TPO）血清水平。本研究纳入了20例患者[10例行原位肝移植（OLT），10例行肝切除（LRX）]。从连续采集的静脉血样本中，通过流式细胞术定量测定GPIIb/IIIa和P-选择素的表面表达，并通过酶联免疫吸附测定法（ELISA）测定TPO血清水平。与LRX组和健康志愿者相比，OLT组循环血小板上的基线GPIIb/IIIa受体表达显著降低。LRX组经凝血酶受体激活肽-6（TRAP-6）激活后，GPIIb/IIIa表达显著增加（P<0.001），而OLT组未增加。TRAP-6刺激后，LRX组P-选择素表达显著增加（P<0.001），与健康志愿者相当，而OLT组仅发现非常低的增加。在OLT组中，TPO血清水平处于正常范围下限，再灌注后24小时升至正常上限以上。这些数据表明，肝移植和肝切除均不影响循环血小板上GPIIb/IIIa和P-选择素的表达。肝硬化患者存在表达缺失，而非肝硬化肝切除患者的基线表达和功能储备未受损。肝移植后，血清TPO水平升高表明移植肝功能恢复，导致外周血小板计数上升。
