The Reevaluation of Thrombin Time Using a Clot Waveform Analysis

Abstract

Object: Although thrombin burst has attracted attention as a physiological coagulation mechanism, clinical evidence from a routine assay for it is scarce. This mechanism was therefore evaluated by a clot waveform analysis (CWA) to assess the thrombin time (TT). Material and Methods: The TT with a low concentration of thrombin was evaluated using a CWA. We evaluated the CWA-TT of plasma deficient in various clotting factors, calibration plasma, platelet-poor plasma (PPP), and platelet-rich plasma (PRP) obtained from healthy volunteers, patients with thrombocytopenia, and patients with malignant disease. Results: Although the TT-CWA of calibration plasma was able to be evaluated with 0.01 IU/mL of thrombin, that of FVIII-deficient plasma could not be evaluated. The peak time of CWA-TT was significantly longer, and the peak height significantly lower, in various deficient plasma, especially in FVIII-deficient plasma compared to calibration plasma. The second peak of the first derivative (1st DP-2) was detected in PPP from healthy volunteers, and was shorter and higher in PRP than in PPP. The 1st DP-2 was not detected in PPP from patients with thrombocytopenia, and the 1st DP-2 in PRP was significantly lower in patients with thrombocytopenia and significantly higher in patients with malignant disease than in healthy volunteers. Conclusion: The CWA-TT became abnormal in plasma deficient in various clotting factors, and was significantly affected by platelets, suggesting that the CWA-TT may be a useful test for hemostatic abnormalities.

Clot Waveform Analysis Demonstrates Low Blood Coagulation Ability in Patients with Idiopathic Thrombocytopenic Purpura

“…However, in some ITP patients there is no correlation between the bleeding symptoms and the extent of thrombocytopenia [18], because total hemostasis involves platelets, coagulation factors, activation factors of coagulation, cofactor for coagulation factor, vessels, and other factors. As the CWA-sTF/FIXa [5,14] and CWA-TT [17] results for patients using PRP can reflect not only the platelet counts but also thrombin bursts [19,20], these assays may be used to evaluate the clotting ability in ITP patients.…”

“…One of the mechanisms underlying the association between platelets and increased blood coagulation ability may involve thrombin bursts [19]. It was reported that CWA-TT reflects a thrombin burst in the presence of platelets [17]. The peak times of CWA-TT using PRP were markedly prolonged and the peak heights of the CWA-TT using both PRP and PPP were markedly low in ITP in comparison to patients with other types of thrombocytopenia.…”

“…The CWA-sTF/FIXa assay [14] was carried out using platelet-rich plasma (PRP) and 2000-fold diluted HemosIL RecombiPlasTin 2G (Instrumentation Laboratory). The TT [17] was measured using thrombin (Thrombin 500 units, Mochida Pharmaceutical Co., Ltd., Tokyo, Japan) 0.5 IU and an ACL-TOP ® system (Instrumentation Laboratory). The CWA-APTT, CWA-sTF/FIXa, and CWA-TT assays show three curves [11].…”

A Clot Waveform Analysis of Thrombin Time Using a Small Amount of Thrombin Is Useful for Evaluating the Clotting Activity of Plasma Independent of the Presence of Emicizumab

“…An optical automatic coagulation analyzer has been able to demonstrate the clot reaction curve of APTT [ 14 , 15 ], diluted prothrombin time (PT) [ 16 ] and thrombin time (TT) [ 17 ]. Such an analysis of the coagulation curve is called a clotting waveform analysis (CWA) [ 18 ].…”

“…In addition, sTF/FIXa may reflect thrombin burst, which mainly depends on the activation of FXI, FVIII and FV [ 20 , 21 ]. CWA-TT has also been reported to be useful for evaluating thrombin burst [ 17 ]. Although measurement of FVIII activity in patients treated with emicizumab using anti-idiotype, monoclonal antibodies is possible [ 22 ], this method is not easy to perform.…”