D-二聚体、超敏CRP在降主动脉夹层诊断与治疗中的意义

目的:探讨D-二聚体、超敏CRP(hs-CRP)在降主动脉夹层诊断与治疗中的意义。方法:本研究入选2013年1月至2013年10月沈阳军区总医院心血管内科收治的降主动脉夹层患者80例,分别于术前、术后第1日及第3日检测所有患者的血清D-二聚体、hs-CRP水平。结果:所有入选患者术前、术后第1日及术后第3日的血清D-二聚体水平均显著高于正常参考值,且不同时期比较有统计学差异(P=0.005)。急性期患者术前、术后第1日血清D-二聚体水平均明显高于相应时期的慢性期患者(P=0.022、P=0.001)。所有患者术前、术后第1日及术后第3日的血清hs-CRP水平均高于正常参考值,但不同时期比较差异无统计学意义(P=0.812)。急性期患者术前及术后第1日血清hs-CRP水平均明显高于慢性期患者(P=0.002;P=0.002)。围手术期未出现因夹层破裂死亡病患,急性肾功能不全1例。结论:联合检测血清D-二聚体、hs-CRP水平有助于辅助诊断降主动脉夹层,且主动脉腔内隔绝术后血清D-二聚体、hs-CRP的水平可提示患者的预后。     

Thrombin bound to a fibrin clot confers angiogenic and haemostatic properties on endothelial progenitor cells

Recent data suggest that endothelial progenitor cells (EPCs) are involved in recanalizing venous thrombi. We examined the impact of a fibrin network, and particularly of adsorbed thrombin, on EPCs derived from cord blood CD34(+) cells. Fibrin networks generated in microplates by adding CaCl(2) to platelet-depleted plasma retained adsorbed thrombin at the average concentration of 4.2 nM per well. EPCs expressed high levels of endothelial cell protein C receptor and thrombomodulin, allowing the generation of activated protein C on the fibrin matrix in the presence of exogenous human protein C. The fibrin matrix induced significant EPC proliferation and, when placed in the lower chamber of a Boyden device, strongly enhanced EPC migration. These effects were partly inhibited by hirudin by 41% and 66%, respectively), which suggests that fibrin-adsorbed thrombin interacts with EPCs via the thrombin receptor PAR-1. Finally, spontaneous lysis of the fibrin network, studied by measuring D-dimer release into the supernatant, was inhibited by EPCs but not by control mononuclear cells. Such an effect was associated with a 10-fold increase in plasminogen activator inhibitor-1 (PAI-1) secretion by EPCs cultivated in fibrin matrix. Overall, our data show that EPCs, in addition to their angiogenic potential, have both anticoagulant and antifibrinolytic properties. Thrombin may modulate these properties and contribute to thrombus recanalization by EPCs.