Varon D, Dardik R, Shenkman B, Kotev-Emeth S, Farzame N, Tamarin I, Savion N
National Hemophilia Center, Sheba Medical Center, Tel-Hashomer, Israel.
Thromb Res. 1997 Feb 15;85(4):283-94. doi: 10.1016/s0049-3848(97)00014-5.
A new method and device in which whole blood platelet deposition and aggregation on extracellular matrix (ECM) under defined shear conditions is quantitatively evaluated was developed. A 0.25 mL aliquot of citrated whole blood is placed on ECM and a defined shear rate is applied for 2 min using a cone and plate device. This is followed by staining and measuring the number of stained objects, the percentage of ECM surface covered with stained objects and the average size of the objects using an image analyzer. When normal blood is analyzed, platelet deposition is a shear and a time dependent process, reaching maximal levels within 2 min at high shear rate (1300 s-1) of about 20% surface coverage and average aggregate size of about 40-50 microns 2. These two parameters demonstrated positive correlation with the platelet count and the hematocrit. Studies using samples from patients with von Willebrand disease (vWD) and Glanzmann's Thrombasthenia (GT) were performed and demonstrated the ability of the new method to detect these pathological conditions. Blood samples of vWD patients showed a very low adhesion and aggregation at high shear rate as reflected by very low surface coverage (5.2%) and average particle size of single platelets (21.3 microns2). GT samples at a high shear rate demonstrated surface coverage similar to normal blood samples (21.7%) but with average particle size of single platelets (21.3 microns2). The new method is an alternative method to clinically evaluate platelet function under close to physiological conditions.
开发了一种新方法和装置，可在规定的剪切条件下定量评估全血血小板在细胞外基质（ECM）上的沉积和聚集情况。将0.25 mL枸橼酸化全血等分试样置于ECM上，使用锥板装置在规定的剪切速率下施加2分钟。随后进行染色，并使用图像分析仪测量染色物体的数量、被染色物体覆盖的ECM表面百分比以及物体的平均大小。分析正常血液时，血小板沉积是一个与剪切和时间相关的过程，在高剪切速率（1300 s-1）下2分钟内达到最大水平，表面覆盖率约为20%，平均聚集体大小约为40 - 50微米²。这两个参数与血小板计数和血细胞比容呈正相关。使用血管性血友病（vWD）和血小板无力症（GT）患者的样本进行的研究表明，该新方法能够检测这些病理状况。vWD患者的血样在高剪切速率下显示出非常低的黏附性和聚集性，表现为极低的表面覆盖率（5.2%）和单个血小板的平均粒径（21.3微米²）。GT样本在高剪切速率下显示出与正常血样相似的表面覆盖率（21.7%），但单个血小板的平均粒径为（21.3微米²）。该新方法是一种在接近生理条件下临床评估血小板功能的替代方法。
