Thrombin generation assay: a useful routine check‐up tool in the management of patients with haemophilia?

Abstract

Severity assessment of patients with haemophilia A (HA) is traditionally based on FVIII activity (FVIII:C). Clinical phenotype of HA patients often differs between individuals with the same FVIII:C determined with clotting and chromogenic assays. The aim of this study was to assess the influence of the FVIII:C on thrombin generation (TG) assay parameters both in vitro and ex-vivo postinfusion plasma. For in-vitro approach, influence of FVIII:C was evaluated on TG parameters in several dilutions of a normal plasma pool with commercial FVIII-depleted-plasma (FVIIIDP) and in others experiments, adding increasing amounts of different commercial FVIII concentrates (Fanhdi, Haemate-P, Hemofil-M and Kogenate Bayer) to FVIIIDP. In a series of 50 postinfusion samples, from HA patients of different severity, we assayed TG and FVIII:C (chromogenic and clotting). In vitro experiments, the 50% of maximum TG peak (TGMP) was achieved using only 5% FVIII:C and the TGMP was obtained with 40% of normal VIII:C. Impaired response compared with normal plasma was found in FVIIIDP using addition of increasing amounts of different commercial FVIII concentrates. An overall good correlation between the two FVIII assays was observed (y = 0.9115x - 0.273, r = 0.975, P < 0.001); TGMP and the Lag-Phase-Time (LPT) provided some discrepant results when compared with the total range of FVIII:C measurements. In contrast, correlations for TGMP, LPT and endogenous thrombin potential were improved in samples restricted to FVIII:C <5%. We conclude that TG parameters tentatively could be a tool to tailor the global haemostatic capacity in haemophilic patients.

Evaluation of Thrombin Generation Assay in Patients With Hemophilia

“…Based on the capacity of plasma to generate thrombin in vitro, TG assay can be used as a more precise and comprehensive method than clotting system function test. 5 As expected, compared to the normal controls, significantly lower levels of ETP and peak in patients with hemophilia were detected. On the other hand, significantly more prolonged durations of lag time, ttpeak, and start tail were determined in patients with hemophilia compared to healthy participants.…”

“…3,11,22 It can be a better predictor of disease phenotype and a more precise method for decision making regarding the management and prophylactic treatment. 5,23 In conclusion, based on our results, although most of the TG parameters evaluated were not significantly correlated with BS of patients with hemophilia based on Tosetto questionnaire, the majority of TG parameters were significantly associated with factor activity level and disease severity. In patients with hemophilia, plasma factor activity level has a poor predictive value in the evaluation of efficacy of treatment, but it seems that TG assay is an appropriate tool for assessment of global hemostasis and better reflection of clotting function in the management of patients with hemophilia.…”

“…3,4 However, large clinical heterogeneity is observed with some patients especially in the severe type. 5,6 The first approach to the patient with bleeding disorder is collection of information on symptoms and bleeding history. It is recognized from clinical experience that in patients with these disorders, the relation between the results of plasma levels of deficient factor by conventional coagulation screening tests and bleeding tendency can vary markedly between deficiencies and between patients.…”

Aptamer ARC19499 mediates a procoagulant hemostatic effect by inhibiting tissue factor pathway inhibitor

“…Thrombin-generation assays such as the CAT assay are used in hemophilia care centers 22,23 because deficiency in FVIII or FIX activity is correlated with reduced thrombin generation. 22,24 The ability of ARC19499 to enhance thrombin generation was tested in 3 platelet-poor hemophilia plasmas: plasma pooled from 7-8 patients with severe hemophilia A (Ͻ 1% FVIII; "hemophilia A plasma"), plasma from 3 different hemophilia A patients with high BLOOD, 19 MAY 2011 ⅐ VOLUME 117, NUMBER 20 For personal use only.…”

A retrospective study of Octaplex in the treatment of bleeding in patients with haemophilia A complicated by inhibitors

“…Thrombin generation parameters of plasma samples drawn from four haemophilia A patients (independent of the retrospective clinical study) were obtained and stored as described previously [20]. The inhibitory potencies of the four individuals were 30, 36, 72 and 159 BU/ml.…”