Comparison of kaolin and tissue factor activated thromboelastography in haemophilia

Young, Guy; Zhang, R.; Miller, Robert; Yassin, D.; Nugent, Diane J.

doi:10.1111/j.1365-2516.2009.02165.x

Cited by 23 publications

(22 citation statements)

References 14 publications

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“…Similar to previous TEG data, this study confirms that kaolin activation is more sensitive at discerning clot initiation (R) and clot propagation (K) compared to TF activation [15,16]. This supports the notion that patients without FVIII inhibitors still retain clot-forming ability from the unmeasurable circulating FVIII while the neutralizing FVIII antibody leads to a 'true' zero FVIII function in patients with inhibitors.…”

Section: Discussionsupporting

confidence: 89%

Is some better than none: are TEG and TGA profiles different in severe FVIII‐deficient patients with inhibitors?

et al. 2014

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Severe factor VIII (FVIII)-deficient patients with and without FVIII inhibitors cannot be distinguished using FVIII levels. The FVIII assay is sensitive to detect factor levels below 1%. While severe FVIII-deficient, non-inhibitor patients have FVIII < 1%, they may retain unmeasurable residual factor activity. In contrast, inhibitor patients have a FVIII antibody that presumably fully eliminates FVIII activity. It is unknown whether thromboelastography (TEG) and thrombin generation assay (TGA) can differentiate between patients with FVIII < 1% with and without the presence of FVIII inhibitors. The primary objective was to discern whether TEG and TGA could differentiate between severe FVIII-deficient patients with and without the presence of FVIII inhibitors. A secondary objective was to correlate TEG and TGA to annualized bleeding rates. This observational study performed TEG and TGA in healthy volunteers (N = 15), severe FVIII-deficient (N = 15) and severe FVIII-deficient patients with inhibitors (N = 15). Kaolin-activated TEG was better at differentiating reaction time (31.3 vs. 120 min respectively, P = 0.004) and kinetics time (6.1 vs. 23.1 min respectively, P = 0.028) between the non-inhibitor and inhibitor patients. TEG activated by tissue factor in plasma-containing corn trypsin inhibitor failed to differentiate groups. The TGA failed to differentiate peak thrombin, endogenous thrombin potential and lag time between groups. There was no correlation between TEG and TGA with annualized bleeding rates. Kaolin-activated TEG, but not TGA, differentiated between severe FVIII-deficient patients with and without inhibitors. These assays did not find a correlation to annualized bleeding rate.

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Section: Discussionsupporting

confidence: 89%

Is some better than none: are TEG and TGA profiles different in severe FVIII‐deficient patients with inhibitors?

et al. 2014

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“…30 More recently, in vitro spiking studies comparing kaolin to 2 concentrations of recombinant human tissue factor (Innovin) demonstrated that the kaolin method is not only effective at discriminating the effects of rFVIIa and rFVIII but is perhaps even better than tissue factor at discriminating these effects. 31,32 Yet another issue with the tissue factor method is the consideration of CTI to inhibit the intrinsic system. Although CTI has been used in some studies that incorporated the tissue factor method, it remains uncertain whether addition of CTI improves the reliability or validity of the assay.…”

Section: Controversiesmentioning

confidence: 99%

Thrombin generation and whole blood viscoelastic assays in the management of hemophilia: current state of art and future perspectives

Young

Sørensen

Dargaud

et al. 2013

Blood

148

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Hemophilia is a bleeding disorder that afflicts about 1 in 5000 males. Treatment relies upon replacement of the deficient factor, and response to treatment both in clinical research and practice is based upon subjective parameters such as pain and joint mobility. Existing laboratory assays quantify the amount of factor in plasma, which is useful diagnostically and prognostically. However, these assays are limited in their ability to fully evaluate the patient’s clot-forming capability. Newer assays, known as global assays, provide a far more detailed view of thrombin generation and clot formation and have been studied in hemophilia for about 10 years. They have the potential to offer a more objective measure of both the hemophilic phenotype as well as the response to treatment. In particular, in patients who develop inhibitors to deficient clotting factors and in whom bypassing agents are required for hemostasis, these assays offer the opportunity to determine the laboratory response to these interventions where traditional coagulation assays cannot. In this article we review the existing literature and discuss several controversial issues surrounding the assays. Last, a vision of future clinical uses of these assays is briefly described.

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“…They are also further cross-linked by covalent bonds formed by factor XIII. Kaolin and TF activation are commonly used for monitoring haemophilia [5–8]. However, TF is a physiological activator while kaolin is a non-physiological particulate activator.…”

Section: Introductionmentioning

confidence: 99%

Measurement of the viscoelastic properties of blood plasma clot formation in response to tissue factor concentration-dependent activation

et al. 2016

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The coagulation of blood plasma in response to activation with a range of tissue factor (TF) concentrations was studied with a quartz crystal microbalance (QCM), where frequency and half width at half maximum (bandwidth) values measured from the conductance spectrum near resonant frequency were used. Continuous measurement of bandwidth along with the frequency allows for an understanding of the dissipative nature of the forming viscoelastic clot, thus providing information on the complex kinetics of the viscoelastic changes occurring during the clot formation process. Using a mathematical model, these changes in frequency and bandwidth have been used to derive novel QCM parameters of effective elasticity, effective mass density and rigidity factor of the viscoelastic layer. The responses of QCM were compared with those from thromboelastography (TEG) under identical conditions. It was demonstrated that the nature of the clot formed, as determined from the QCM parameters, was highly dependent on the rate of clot formation resulting from the TF concentration used for activation. These parameters could also be related to physical clot characteristics such as fibrin fibre diameter and fibre density, as determined by scanning electron microscopic image analysis. The maximum amplitude (MA) as measured by TEG, which purports to relate to clot strength, was unable to detect these differences.

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Comparison of kaolin and tissue factor activated thromboelastography in haemophilia

Cited by 23 publications

References 14 publications

Is some better than none: are TEG and TGA profiles different in severe FVIII‐deficient patients with inhibitors?

Is some better than none: are TEG and TGA profiles different in severe FVIII‐deficient patients with inhibitors?

Thrombin generation and whole blood viscoelastic assays in the management of hemophilia: current state of art and future perspectives

Measurement of the viscoelastic properties of blood plasma clot formation in response to tissue factor concentration-dependent activation

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