Asakura Hidesaku
Department of Internal Medicine (III), Kanazawa University School of Medicine, Kanazawa 920-8641, Japan.
Rinsho Byori. 2011 Oct;59(10):970-7.
Blood dose not normally coagulate in the blood vessels covered with endothelial cells, because these cells contain some substances responsible for antithrombotic action such as thrombomodulin, heparin-like substance, prostacyclin, nitric oxide and tissue plasminogen activator. Most important role of blood coagulation is hemostasis. Blood can coagulate in two ways: intrinsic coagulation pathway and extrinsic coagulation pathway that is activated by negatively charged substances and FVIIa-tissue-factor (TF) complex, respectively. Prothrombin time(PT) can represent extrinsic pathway, while activated partial thromboplastin time (APTT) can represent intrinsic pathway. PT is prolonged in such diseases as vitamin K deficiency, hepatic failure and warfarin intake, while APTT is prolonged such diseases as hemophilia A & B, von Willebrand disease and lupus anticoagulant. Cross mixing test is very useful to assess prolonged clotting time. FDP means fibrin/fibrinogen degradation products and D-dimer is the smallest products of fibrin degradation. These markers are often used to diagnose disseminated intravascular coagulation (DIC) and deep vein thrombosis (DVT). Thrombin-antithrombin complex (TAT) and plasmin-alpha2 plasmin inhibitor (PIC) can be used to evaluate the extent of coagulation and fibrinolysis activation, respectively. These two markers is essential for classify the pathophysiology of DIC: DIC with suppressed fibrinolysis, enhanced fibrinolysis or balanced fibrinolysis. In conclusion, exact interpretation of hemostatic and fibrinolytic markers is one of the most important abilities in clinical situation.
血液通常不会在覆盖有内皮细胞的血管中凝固,因为这些细胞含有一些负责抗血栓形成作用的物质,如血栓调节蛋白、类肝素物质、前列环素、一氧化氮和组织纤溶酶原激活剂。血液凝固的最重要作用是止血。血液可通过两种方式凝固:内源性凝血途径和外源性凝血途径,分别由带负电荷的物质和FVIIa-组织因子(TF)复合物激活。凝血酶原时间(PT)可代表外源性途径,而活化部分凝血活酶时间(APTT)可代表内源性途径。在维生素K缺乏、肝功能衰竭和服用华法林等疾病中PT会延长,而在甲型和乙型血友病、血管性血友病和狼疮抗凝物等疾病中APTT会延长。交叉混合试验对于评估延长的凝血时间非常有用。FDP是指纤维蛋白/纤维蛋白原降解产物,D-二聚体是纤维蛋白降解的最小产物。这些标志物常用于诊断弥散性血管内凝血(DIC)和深静脉血栓形成(DVT)。凝血酶-抗凝血酶复合物(TAT)和纤溶酶-α2纤溶酶抑制剂(PIC)可分别用于评估凝血和纤溶激活的程度。这两种标志物对于DIC病理生理学的分类至关重要:纤维蛋白溶解受抑制、纤维蛋白溶解增强或纤维蛋白溶解平衡的DIC。总之,准确解读止血和纤溶标志物是临床中最重要的能力之一。