In the context of hemophilia, it is well know that the level of factor VIII alone does not reflect the clinical phenotype of the patients in an accurate way. At equal factor VIII levels, certain patients will bleed more than others. The thrombin generation test (TGT) is a test that seems to provide a better prediction of the overall hemostatic status of an individual patient. In a previous study, the investigators have established normal reference values of the thrombin generation curve in children aged 6 months to 16 years and adults. The goal was to evaluate the use of this test in different clinical contexts and in severe hemophilia patients in particular. A pilot study showed that the patients having a thrombin generation \<150 had a severe phenotype, whether those who received an appropriate prophylaxy had a thrombin generation superior to 150. Moreover, the investigators now have access to a software tool that allows them to individually determine the pharmacokinetic profile of the factor VIII injected to each patient. The factor VIII concentration is measured at injection and 30 minutes, 1 hour, 2 hours and 24 hours afterwards. The introduction of these concentrations in the software allows to obtain the half-life of factor for a given patient, the maximum peak, and the minimum factor level (though level). The injected dosis might be sufficient (disappearance of substantial diminution of the bleedings) or unsufficient (persisting bleeding) for a given patient. This study aims: * to measure the pharmacokinetic profile of factor VIII by two different methods, the time-based method and the chromogenic method * to correlate the results with the TGT results obtained at the same time points and determine which method gives the best correlation * to link the clinical symptomatology (improved symptomatology or not) with the TGT results * to determine which minimal TGT result is linked to a minimal bleeding rate * to adapt the prophylactic dosis of the patient in a personalized way.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
PREVENTION
Masking
NONE
Enrollment
50
Chronometric method of FVIII dosage on STA-R PLC automate (reactive Cephascreen STAGO, Unicalibrateur STAGO, plasma deficient Cryopep, Controls STAGO)
Chromogenic FVIII assay method ( "BIOPHEN FVIII: C" and "BIOPHEN Factor IX" of the firm Hyphen BioMed)
Briefly: the measurement of thrombin generation is performed by the technique of calibrated and automated Thrombinography (CAT) developed by Hemker HC. This technique allows the simultaneous analysis of multiple samples using a fluorometer (Fluoroscan Ascent, ThermoLabsystems OY, Helsinki, Finland) and a Thrombinoscope® software that converts the fluorescence intensity obtained by concentration of active thrombin. The reagent "PPP-reagent Low" respectively containing 1pm FT and 4μM phospholipid (PL) as a final concentration will be used.
CHU Brugmann
Brussels, Belgium
RECRUITINGHUDERF
Brussels, Belgium
RECRUITINGCentre Hospitalier Régional de la Citadelle de Liège
Liège, Belgium
RECRUITINGCHC de Liège
Liège, Belgium
RECRUITINGCHU Liège Sart Tilman
Liège, Belgium
RECRUITINGFactor VIII blood concentration - chronometric method
Chronometric method of FVIII dosage on STA-R PLC automate (reactive Cephascreen STAGO, Unicalibrateur STAGO, plasma deficient Cryopep, Controls STAGO)
Time frame: baseline: at factor VIII injection
Factor VIII blood concentration - chronometric method
Chronometric method of FVIII dosage on STA-R PLC automate (reactive Cephascreen STAGO, Unicalibrateur STAGO, plasma deficient Cryopep, Controls STAGO)
Time frame: 30 minutes after factor VIII injection
Factor VIII blood concentration - chronometric method
Chronometric method of FVIII dosage on STA-R PLC automate (reactive Cephascreen STAGO, Unicalibrateur STAGO, plasma deficient Cryopep, Controls STAGO)
Time frame: 60 minutes after factor VIII injection
Factor VIII blood concentration - chronometric method
Chronometric method of FVIII dosage on STA-R PLC automate (reactive Cephascreen STAGO, Unicalibrateur STAGO, plasma deficient Cryopep, Controls STAGO)
Time frame: 120 minutes after factor VIII injection
Factor VIII blood concentration - chronometric method
Chronometric method of FVIII dosage on STA-R PLC automate (reactive Cephascreen STAGO, Unicalibrateur STAGO, plasma deficient Cryopep, Controls STAGO)
Time frame: 24h after factor VIII injection
Factor VIII blood concentration - Chromogenic method
Chromogenic FVIII assay method ( "BIOPHEN FVIII: C" and "BIOPHEN Factor IX" of the firm Hyphen BioMed)
Time frame: baseline: at factor VIII injection
Factor VIII blood concentration - Chromogenic method
Chromogenic FVIII assay method ( "BIOPHEN FVIII: C" and "BIOPHEN Factor IX" of the firm Hyphen BioMed)
Time frame: 30 minutes after factor VIII injection
Factor VIII blood concentration - Chromogenic method
Chromogenic FVIII assay method ( "BIOPHEN FVIII: C" and "BIOPHEN Factor IX" of the firm Hyphen BioMed)
Time frame: 60 minutes after factor VIII injection
Factor VIII blood concentration - Chromogenic method
Chromogenic FVIII assay method ( "BIOPHEN FVIII: C" and "BIOPHEN Factor IX" of the firm Hyphen BioMed)
Time frame: 120 minutes after factor VIII injection
Factor VIII blood concentration - Chromogenic method
Chromogenic FVIII assay method ( "BIOPHEN FVIII: C" and "BIOPHEN Factor IX" of the firm Hyphen BioMed)
Time frame: 24h after factor VIII injection
total thrombin generation
the measurement of thrombin generation is performed by the technique of calibrated and automated Thrombinography (CAT) developed by Hemker HC. This technique allows the simultaneous analysis of multiple samples using a fluorometer (Fluoroscan Ascent, ThermoLabsystems OY, Helsinki, Finland) and a Thrombinoscope® software that converts the fluorescence intensity obtained by concentration of active thrombin.
Time frame: baseline: at factor VIII injection
total thrombin generation
the measurement of thrombin generation is performed by the technique of calibrated and automated Thrombinography (CAT) developed by Hemker HC. This technique allows the simultaneous analysis of multiple samples using a fluorometer (Fluoroscan Ascent, ThermoLabsystems OY, Helsinki, Finland) and a Thrombinoscope® software that converts the fluorescence intensity obtained by concentration of active thrombin.
Time frame: 30 minutes after factor VIII injection
total thrombin generation
the measurement of thrombin generation is performed by the technique of calibrated and automated Thrombinography (CAT) developed by Hemker HC. This technique allows the simultaneous analysis of multiple samples using a fluorometer (Fluoroscan Ascent, ThermoLabsystems OY, Helsinki, Finland) and a Thrombinoscope® software that converts the fluorescence intensity obtained by concentration of active thrombin.
Time frame: 60 minutes after factor VIII injection
total thrombin generation
the measurement of thrombin generation is performed by the technique of calibrated and automated Thrombinography (CAT) developed by Hemker HC. This technique allows the simultaneous analysis of multiple samples using a fluorometer (Fluoroscan Ascent, ThermoLabsystems OY, Helsinki, Finland) and a Thrombinoscope® software that converts the fluorescence intensity obtained by concentration of active thrombin.
Time frame: 120 minutes after factor VIII injection
total thrombin generation
the measurement of thrombin generation is performed by the technique of calibrated and automated Thrombinography (CAT) developed by Hemker HC. This technique allows the simultaneous analysis of multiple samples using a fluorometer (Fluoroscan Ascent, ThermoLabsystems OY, Helsinki, Finland) and a Thrombinoscope® software that converts the fluorescence intensity obtained by concentration of active thrombin.
Time frame: 24h after factor VIII injection
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.