实验诊断学—止血凝血实验(双语版)

止血凝血

2013年3月7日

19:32

血管壁止血作用：

1.收缩反应：neurohumoral regulation

→endothelial cells contract

→slow blood flow

→bleeding stops

2.激活血小板

Collagen exposed →activate vWF →collagen-vWF-platelet complex →platelet adheresion

3.促进血液凝固过程

Endothelial cells →tissue factor →extrinsic pathway of blood coagulation

Endothelial cells →activate FXII →intrinsic pathway of blood coagulation

4.抑制纤维蛋白溶解

Endothelial cells →PAI(plasminogen activator inhibitor)

一、血管壁检测——screening test

1.BT

2.CRT

1.bleeding time, BT

测定皮肤受特定条件的外伤后，出血自然停止所需的时间

——反应毛细血管壁和血小板止血功能

参考值：6.9±2.1min

abnormal：>9min

Clinical significance:

Influenced by the amount of platelet and the condition of the vascular wall

BT increase:

1.Abnormal function or amount of the platelet: thrombasthenia血小板无力症

2.abnormal condition of the vascular wall: hereditary capillary rise syndrome

3.intergrated factors: VWD、DIC

BT decrease:

Severe hypercoagulable state and thrombotic diseases:

Cerebral thrombosis、cardiac infarction、diabetes mellitus、hyperlipidemia、DVT、hypercoagulable state of DIC

2.Capillary resistance test, CRT

毛细血管的完整性与其本身的结构、功能，血小板的质、量，以及一些体液因素有关。用加压的方法来部分阻止静脉血液回流，可以根据一定范围内新出血点的数目及大小来估计毛细血管的脆性。

Reference value: in the diameter of 5cm

Male: less than 5 spots

Female and Children: less than 10 spots

Clinical significance:

Positive when the amount of spots is more than the normal level

structural or functional defect of the vascular wall:

hereditary capillary rise syndrome、angiohemophilia

Quality and quantity defect of platelet:

Thrombocytopenia 血小板减少症

Platelet dysfunction syndrome 血小板功能缺陷症

二、血小板检测

1.keep the integrity of vascular wall and the permeability of capillary

2.coagulation

primary hemostasis:

Aggregation→adheresion→release→contract

secondary hemostasis:

Provide the catalytic surface of the coagulation with PF3's participation

Screening test:

1.platelet count

Reference value: （100-300）×10^9/L

Clinical significance:

Thrombopenia:

Production dysfunction:

Hematopoietic dysfunction

Over damage and consumption of platelet:

ITP、DIC、TTP

Abnormal distribution of platelet:

Splenomegaly、dilution of blood

Thrombocytosis:

Primary increase: bone marrow incremental diseases( polycythemia vera真性红细胞增多症、primary thrombocythemia、early stage of Myelofibrosis、hemorrhage )

Secondary increse: acute infection、hemolysis、certain kind of CA

2.clot retraction test, CRT

血液凝固后，由于血小板释放的PF4（血栓收缩蛋白），使血块收缩，血清析出。 测定析出血清量占全血量的百分数来表示血块收缩的程度，可间接了解血小板功能情况。

Reference value:

定量法（凝块法）：37℃1小时其血块收率为65.8%±11.0%

定性试验：37℃2小时开始收缩，18-24小时完全收缩（血清占全血1/3-1/2）。

Clinical significance:

Clot retracting ability is based on the platelet、fribinogen,Fg、amount of RBC

Incomplete retraction:

→Quantity disorder of platelet:

Thrombasthenia、ITP、thrombocytosis

→disorder of fribinogen:

Hypofribinogenosis

→increase of RBC: erythrocytosis

Over retraction:

Congenital/acquired FXIII deficiency syndrome

Diagnostic test

3.platelet associated immunoglobulin, PAIg

本试验是免疫性血小板减少性紫癜诊断、疗效及预后估计的重要指标，也有助于其他血小板疾病