Gorog Thrombosis Test: analysis of factors influencing occlusive thrombus formation

Abstract

We used the Gorog Thrombosis Test to analyze the factors influencing the occlusion time, which represents platelet activation and subsequent occlusive thrombus formation, in 132 healthy Japanese volunteers (116 men, 16 women; mean age, 45.0 +/- 12.0 years). The Gorog Thrombosis Test was designed to evaluate platelet aggregation and thrombolytic activity under a high shear stress condition (175 dynes/cm) in a native blood sample in vitro. The mean +/- SD occlusion time was 154.8 +/- 64.7 s (men, 153.4 +/- 64.2 s and women, 165.4 +/- 56.5 s). The occlusion time was inversely correlated with von Willebrand factor ristocetin cofactor activity (VWF:Rco) (r = -0.242, P = 0.0055) and von Willebrand factor antigen (r = -0.230, P = 0.0080). The mean occlusion time in the group with VWF:Rco of at least 170% (137 s) was significantly shorter than that in the group with VWF:Rco less than 170% (156 s, P < 0.05). Platelet counts, other coagulation markers and smoking showed no significant correlations with occlusion time. Red blood cells (r = -0.177, P = 0.0365), hemoglobin (r = -0.191, P = 0.0245) and hematocrit (r = -0.182, P = 0.0329) also showed inverse correlations with the occlusion time. This report is the first to clearly demonstrate the role of von Willebrand factor in the formation of occlusive thrombi in the Gorog Thrombosis Test.

Global Thrombosis Test – a possible monitoring system for the effects and safety of dabigatran

“…The OT value was inversely correlated with vWF ristocetin cofactor activity and vWF antigen. This report is the first to clearly demonstrate the role of vWF in the formation of occlusive thrombi in the Gorog Thrombosis Test [ 12 ]. Thus, the OT value in the GTT system is directly determined by vWF.…”

Platelet Function Tests: Why They Fail to Guide Personalized Antithrombotic Medication

“…At elevated shear stress, platelet thrombus formation depends entirely on the binding of vWF to platelet glycoprotein Iba and glycoprotein IIb/IIIa receptors. This is reflected in the GTT, in which occlusion time was inversely correlated with plasma vWF antigen and vWF ristocetin cofactor activity, 19 and antagonism of vWF with the glycoprotein Ib inhibitor aurin tricarboxylic acid significantly inhibited occlusion, 20 showing that vWF is essential for thrombosis formation in this system.…”

Platelet Function and Spontaneous Thrombolytic Activity of Patients with Cerebral Infarction Assessed by the Global Thrombosis Test

“…Most of these tests are not appropriate for bedside use, however [22,23] . In contrast, the GTT used in the present study can be readily adapted for this purpose [17,18] and enables measurements rapidly after blood sampling.…”

“…Shear-induced platelet function tests using non-anticoagulated whole blood have been shown to be physiologically relevant to thrombosis in vivo [17,18,22,23] . Most of these tests are not appropriate for bedside use, however [22,23] .…”

“…Results using these techniques have been encouraging, and have prompted the further development of global haemostasis analysers. The Global Thrombosis Test (GTT) [16][17][18][19][20] was established on the basis of a series of developments of this nature, including the Haemostatometer [21,22] and the Thrombotic Status Analyser [23] . The technique is particularly used to assess platelet responses to activation by shear force alone, using non-anticoagulated whole blood [16][17][18][19][20][21][22][23][24][25][26][27] .…”