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1.
Eur J Health Econ ; 23(1): 23-32, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34236542

ABSTRACT

OBJECTIVE: The Hemraude study was conducted to describe the profile of patients with HA, disease management, and economic burden in a collective perspective. METHODS: This retrospective study was conducted using the French administrative healthcare claims database SNIIRAM/SNDS. Male patients treated for hemophilia A with a long-term illness (ALD) status or invalidity were included in the study between January 1, 2016 and December 31, 2017. Patients were classified in six treatment groups: no treatment, on-demand FVIII, prophylactic FVIII, FVIII in immune tolerance induction (ITI) protocol, on-demand bypassing agents, and prophylactic bypassing agents. Patients treated with FVIII in ITI protocol and those treated with bypassing agents are deemed to have developed inhibitors. HA patients were compared to a control population without coagulation disorder and matched (ratio 1:3) on age and sex. RESULTS: A total of 4172 patients were included in the analysis, aged on average 35.2 years, 5.3% had HIV infection, and 8.8% had hepatitis B or C. In 2017, half of the patients received no treatment for HA, 46.7% were treated with FVIII (25% on demand, 20.6% with prophylaxis, and 1.1% ITI), 1.5% with bypassing agents. Patients treated with prophylactic treatments, either inhibitor or non-inhibitor, were less likely to be hospitalized for severe bleeding compared to patients receiving on-demand treatments. The average annual costs for HA management per patient were 72,209.60 €. The highest costs were observed in patients treated with FVIII in ITI protocol and those receiving prophylactic bypassing agents. CONCLUSION: Direct costs of HA treatments for HA may be very high especially in the small percentage of patients developing inhibitors or treated with ITI protocol.


Subject(s)
HIV Infections , Hemophilia A , Aged , Factor VIII/therapeutic use , Hemophilia A/drug therapy , Hemorrhage , Humans , Male , Retrospective Studies
2.
Arch Pediatr ; 28(2): 156-158, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33277135

ABSTRACT

BACKGROUND: The range of normal values for coagulation factors in the healthy newborn was described 30 years ago but since then the reagents, automated systems, and dosing techniques have changed considerably. For 30 years, several authors have tried to update the standards and references in children using updated reagents but the newborn and infant population in these studies has been quite small, limiting the findings. The aim of this study was to establish the normal coagulation standards in healthy newborns. METHODS: We included all consecutive healthy newborns with pyloric stenosis presenting to our reference center over a period of 5 years. We calculated the reference ranges defined as mean±2 SD. Normality of distribution was checked graphically and by using the Shapiro-Wilk test. Correlations between two continuous variables were assessed using Spearman's rank coefficient correlation. Statistical testing was done at the two-tailed α-level of 0.05. Data were analyzed using the SAS software package, release 9.4 (SAS Institute, Cary, NC). RESULTS: We included 112 healthy newborns and infants. The median age was 35.5 days (15.0-88.0), median weight was 4062g (2855-6040), and 90.2% were boys. Activated partial thromboplastin time (aPTT) and prothrombin time (PT) were not correlated with age (P=0.92 and P=0.21, respectively) or with weight (P=0.16 and P=0.90, respectively). The reference range was 28.6-46.2 s for aPTT, 0.91-1.49 for aPTT ratio, and 71.3-110.6 s for PT. Regarding fibrinogen (n=24), the median was 2.2g/L (1.2-3.2); the median for factor II was 67.0U/dL (51.0-130.0; n=20), and 101.5U/dL for factor V (68.0-233.0; n=20). Regarding factor VIII, the median was 75.0U/dL (45.0-152.0; n=25), 49.0U/dL for factor IX (32.0-96.0; n=25) and 53.0U/dL (29.0-112.0) for factor XI (n=23). CONCLUSION: This study can help to establish standards for coagulation testing in this very specific population. Indeed, our study represents the largest newborn population in a recent investigation of PT and aPTT using updated reagents.


Subject(s)
Blood Coagulation Tests/standards , Blood Coagulation/physiology , Blood Coagulation Tests/methods , Female , Humans , Infant , Infant, Newborn , Male , Reference Standards , Reference Values , Retrospective Studies
3.
Haemophilia ; 24 Suppl 4: 5-19, 2018 May.
Article in English | MEDLINE | ID: mdl-29687935

ABSTRACT

The fifth Åland Island meeting on von Willebrand disease (VWD) was held on the Åland Islands, Finland, from 22 to 24 September 2016-90 years after the first case of VWD was diagnosed in a patient from the Åland Islands in 1926. This meeting brought together experts in the field of VWD to share knowledge and expertise on current trends and challenges in VWD. Topics included the storage and release of von Willebrand factor (VWF), epidemiology and diagnostics in VWD, treatment of VWD, angiogenesis and VWF inhibitors.


Subject(s)
von Willebrand Diseases/diagnosis , von Willebrand Diseases/therapy , Humans , von Willebrand Diseases/epidemiology , von Willebrand Diseases/etiology
4.
Haemophilia ; 23 Suppl 1: 4-13, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27990784

ABSTRACT

The high incidence of inhibitors against factor VIII (FVIII) concentrates in patients with haemophilia A has encouraged debate as to whether product-type plays a role. There is debate in the literature as to whether rFVIII concentrates are associated with a higher incidence of inhibitors compared to pdFVIII products. The management of haemophilia in patients with inhibitors includes on-demand/prophylaxis treatment with bypassing agents, and/or immune tolerance induction (ITI). However, these options create an economic and emotional burden on patients, their families and healthcare practitioners. Although ITI eliminates inhibitors successfully in 60-80% of cases, it is costly. Despite high costs, preliminary data from a decision analytical model have indicated that ITI is economically advantageous compared with on-demand/prophylactic treatment with bypassing agents. In patients with persistent inhibitors and those who are not candidates for ITI or have failed ITI, bleeding-related mortality and morbidity increase and quality of life decreases, compared with non-inhibitor patients. This article provides an update on the risk of inhibitor development and discusses best management approaches for patients with high-risk factors for inhibitor development.


Subject(s)
Blood Coagulation Factor Inhibitors/therapeutic use , Factor VIII/antagonists & inhibitors , Hemophilia A/drug therapy , Blood Coagulation Factor Inhibitors/pharmacology , Humans , Observational Studies as Topic , Randomized Controlled Trials as Topic
6.
Haemophilia ; 21(4): 481-9, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25817556

ABSTRACT

Factor XI (FXI)-deficient patients may develop excessive bleeding after trauma or surgery. Replacement therapy should be considered in high-risk situations, especially when FXI levels are below 20 IU dL(-1) . HEMOLEVEN is a human plasma-derived factor XI concentrate available in France since 1992, but there are few data regarding its use by physicians. This prospective study assessed the use, efficacy and safety of HEMOLEVEN in common clinical practice. HEMOLEVEN was evaluated in FXI-deficient patients in 13 French centres in a 3-year postmarketing study. Forty-four patients (30 females, 14 males) received 67 treatments. The median age was 37 years (8 months-91 years). Basal FXI levels were <1 to 51 IU dL(-1) (median: 5.5); 29 patients were severely FXI-deficient (<20 IU dL(-1) ). FXI was administered prophylactically before 43 surgical procedures, 10 invasive procedures, 8 vaginal deliveries, or as curative treatment for six bleeds. The efficacy was assessed as excellent/good in 63, moderate in two and undetermined in two treatments. Seven patients experienced seven adverse effects, including two rated as serious: one sudden massive pulmonary embolism with fatal outcome and one case of inhibitor to FXI. HEMOLEVEN is effective for bleeding prevention in FXI deficiency. However, considering the benefit/risk ratio observed in relation to dosage in this study; firstly, it should be used sparingly due to its potential prothrombotic effect; secondly, new prescription procedures should be defined to adapt the dosage, especially in patients with intrinsic and/or acquired risk factors for thrombosis.


Subject(s)
Factor XI Deficiency/drug therapy , Factor XI/therapeutic use , Thrombosis/etiology , Adolescent , Adult , Aged , Aged, 80 and over , Blood Loss, Surgical/prevention & control , Child , Child, Preschool , Factor XI/adverse effects , Factor XI/immunology , Female , Hemostasis, Surgical , Humans , Infant , Male , Middle Aged , Product Surveillance, Postmarketing , Prospective Studies , Risk Factors , Young Adult
9.
Haemophilia ; 19(4): 564-70, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23574453

ABSTRACT

Although extremely rare, acquired haemophilia A (AHA) can cause severe bleeding, which may be fatal. The underlying causes of autoantibody development are not fully understood. Treatment goals are bleeding control and autoantibody eradication. At the time of our study, there was no consensus on a standard treatment strategy for AHA. Previous data were mainly retrospective or from single-centre cohorts. We conducted a prospective, controlled, registry-based study of patients with AHA in France. The prospective French registry (Surveillance des Auto antiCorps au cours de l'Hémophilie Acquise [SACHA]) collected data on prevalence, clinical course, disease associations and outcomes for haemostatic treatment and autoantibody eradication in 82 patients with a 1-year follow-up. Similar to earlier studies, the prevalence of AHA was higher in the elderly, with two thirds of patients aged >70 years. Around half of AHA cases were associated with underlying disease, most commonly autoimmune disease and cancer in younger and older patients respectively. Haemostatic treatment was initially administered to 46% of patients. Complete resolution or improvement of initial bleeding occurred in 22/27 (81%) rFVIIa-treated patients and in all six cases receiving pd-aPCC. The majority of patients (94%) received immunosuppressive therapy, with complete remission at 3 months in 61% (36/59) and in 98% (50/51) at 1 year. Overall mortality was 33%: secondary to bleeding in only three patients but to sepsis in 10. Bypassing agents were effective at controlling bleeding in patients with AHA. Immunosuppressive therapy should be used early but with caution, particularly in elderly patients.


Subject(s)
Hemophilia A/drug therapy , Hemophilia A/epidemiology , Registries , Adult , Age Distribution , Aged , Aged, 80 and over , Autoantibodies/immunology , Cause of Death , Factor VIII/immunology , Female , France/epidemiology , Hemophilia A/complications , Hemophilia A/mortality , Hemorrhage/complications , Hemorrhage/drug therapy , Hemostatics/therapeutic use , Humans , Immunosuppressive Agents/therapeutic use , Male , Middle Aged , Prospective Studies , Recurrence , Treatment Outcome
10.
J Thromb Haemost ; 9(6): 1191-9, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21489128

ABSTRACT

BACKGROUND: Recombinant activated factor VIIa (rFVIIa) is used to treat bleeds in hemophilia patients with inhibitors. A subcutaneous formulation could potentially improve its half-life and make it suitable for prophylactic treatment. OBJECTIVES: A study was conducted to determine the safety of subcutaneously administered rFVIIa in patients with hemophilia and the pharmacokinetic profile (including bioavailability). PATIENTS/METHODS: This was a multicenter, open-label, cross-over comparison of single doses of intravenous rFVIIa 90µgkg(-1) and a new formulation of rFVIIa for subcutaneous injection at dose levels of 45, 90, 180, 270 and 360µgkg(-1) . Sixty subjects (12 per dose cohort) with hemophilia A or B were enrolled. RESULTS: Subcutaneously administered rFVIIa showed lower mean peak plasma concentrations and prolonged FVII activity (C(max) , 0.44-5.16IU mL(-1) [across doses]; t(1/2) , 12.4h; t(max) , 5.6h) compared with intravenously administered rFVIIa (C(max) , 51.7IUmL(-1) ; t(1/2) , 2.7h; t(max) , <10min). The absolute bioavailability of subcutaneous rFVIIa ranged from 21.1 to 30.1% across dose levels. Dose proportionality was observed within a 2-fold dose increase but not across the full dose range. No thromboembolic events, drug-related serious adverse events, severe injection-site reactions or neutralizing antibodies were reported (primary endpoint). Mild and moderate injection-site reactions were more frequent with subcutaneous than with intravenous injections. CONCLUSION: This phase I clinical trial did not identify safety concerns of prolonged exposure to rFVIIa administered subcutaneously in single doses to hemophilia patients.


Subject(s)
Factor VIIa/administration & dosage , Hemophilia A/drug therapy , Hemophilia B/drug therapy , Adolescent , Adult , Aged , Biological Availability , Child , Cross-Over Studies , Dose-Response Relationship, Drug , Drug-Related Side Effects and Adverse Reactions , Factor VIIa/adverse effects , Factor VIIa/pharmacokinetics , Hemorrhage/prevention & control , Humans , Injections, Subcutaneous , Middle Aged , Pharmacokinetics , Recombinant Proteins/administration & dosage , Recombinant Proteins/adverse effects , Recombinant Proteins/pharmacokinetics , Young Adult
12.
Haemophilia ; 17(6): 944-51, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21371195

ABSTRACT

Type 2N von Willebrand's disease (VWD) is characterized by a factor VIII (FVIII) deficiency and a low FVIII/VWF ratio related to a markedly decreased affinity of von Willebrand factor (VWF) to FVIII. Type 2N VWD is diagnosed using assays allowing the measurement of plasma VWF capacity to bind FVIII (VWF:FVIIIB). These assays, crucial in order to distinguish type 2N VWD patients from mild haemophiliacs A and haemophilia A carriers, remain exclusively homemade and limited to laboratories possessing a high level of expertise in VWD. We evaluated the first commercial ELISA (Asserachrom® VWF:FVIIIB; Stago) comparated to a reference method in a multicentric study involving 205 subjects: 60 healthy volunteers, 37 haemophiliacs A, 17 haemophilia A carriers, 37 patients with type 2N VWD, 9 heterozygous carriers for a 2N mutation and 45 patients with miscellaneous other types of VWD (all previously characterized). A diluted plasma sample adjusted to 10 IU dL(-1) of VWF:Ag was incubated with a rabbit antihuman VWF polyclonal antibody. After removing the endogenous FVIII, recombinant FVIII (rFVIII) was added and bound rFVIII was quantified using a peroxydase-conjugated mouse antihuman FVIII monoclonal antibody. The intra-assay and inter-assay reproducibility was satisfactory. In all subgroups, both methods were well correlated. All type 2N VWD patients exhibited a markedly decreased VWF:FVIIIB (lower than 15%) and all heterozygous 2N carriers had a moderately decreased VWF:FVIIIB (between 30% and 65%). All controls (healthy subjects, haemophiliacs A and haemophilia A carriers) had a normal VWF:FVIIIB (higher than 80%) except one healthy volunteer and three haemophiliacs who exhibited a moderately decreased VWF:FVIIIB suggesting a heterozygous status for a 2N mutation. In conclusion, the Asserachrom® VWF:FVIIIB is easy to perform, standardized and accurate for type 2N VWD diagnosis with a 100% sensitivity and specificity.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Factor VIII/metabolism , von Willebrand Disease, Type 2/diagnosis , von Willebrand Factor/metabolism , Hemophilia A/diagnosis , Humans , Mutation/genetics , Reagent Kits, Diagnostic , Reference Values , Reproducibility of Results , Sensitivity and Specificity , von Willebrand Disease, Type 2/genetics , von Willebrand Diseases/diagnosis
14.
Thromb Res ; 126(3): 227-31, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20650506

ABSTRACT

BACKGROUND: Accurate measurement of von Willebrand factor (VWF) is a critical requirement for the diagnosis of von Willebrand disease (VWD). AIM OF THE STUDY: To evaluate the diagnostic efficiency of a rapid quantitative test for the measurement of VWF antigen (VWF:Ag) in type 1 VWD. PATIENTS AND METHODS: VWF:Ag was measured with an ELISA in a robotic instrument, as a reference method, and with a fully automated latex-immunoassay (LIA) on an ACL 9000 analyser in 1,716 subjects enrolled within the Molecular and Clinical Markers for Diagnosis and Management of Type 1 von Willebrand Disease (MCMDM-1VWD) Study. Among these subjects, 1,049 were healthy controls, 281 healthy family members and 386 affected members from 127 European families with type 1 VWD. RESULTS: The assay linearity range was 10-125 IU/dL for LIA (R2=0.99) and 5-133 IU/dL for ELISA (R2=0.99). The inter-assay CV for low VWF levels (approximately 30 IU/dL) was 2% for the LIA test and 8.7 % for ELISA. The sensitivity for detection of type 1 VWD affected members was 86% and the specificity 91% for LIA, 87% and 90% for ELISA. A receiver-operator (ROC) analysis disclosed only a marginal difference between the two tests, LIA having a slightly greater area under the curve (0.94 vs. 0.93, p=0.03). CONCLUSION: VWF:Ag LIA compared well to standard ELISA in this large population of patients and controls, showing better CV. However the lower detection limit for the VWF:Ag LIA compared to the VWF:Ag ELISA means that the LIA assay is less good at discriminating between type 3 VWD and moderate type 1 VWD.


Subject(s)
Enzyme-Linked Immunosorbent Assay , Latex Fixation Tests , von Willebrand Disease, Type 1/diagnosis , von Willebrand Factor/analysis , Adolescent , Adult , Aged , Aged, 80 and over , Automation, Laboratory , Biomarkers/blood , Case-Control Studies , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay/standards , Europe , Humans , Latex Fixation Tests/standards , Middle Aged , Observer Variation , Predictive Value of Tests , ROC Curve , Reference Standards , Reproducibility of Results , Robotics , Sensitivity and Specificity , Young Adult , von Willebrand Disease, Type 1/blood
15.
Haemophilia ; 16(6): 866-77, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20579113

ABSTRACT

Postauthorization safety surveillance of factor VIII (FVIII) concentrates is essential for assessing rare adverse event incidence. We determined safety and efficacy of ADVATE [antihaemophilic factor (recombinant), plasma/albumin-free method, (rAHF-PFM)] during routine clinical practice. Subjects with differing haemophilia A severities and medical histories were monitored during 12 months of prophylactic and/or on-demand therapy. Among 408 evaluable subjects, 386 (95%) received excellent/good efficacy ratings for all on-demand assessments; the corresponding number for subjects with previous FVIII inhibitors was 36/41 (88%). Among 276 evaluable subjects receiving prophylaxis continuously in the study, 255 (92%) had excellent/good ratings for all prophylactic assessments; the corresponding number for subjects with previous FVIII inhibitors was 41/46 (89%). Efficacy of surgical prophylaxis was excellent/good in 16/16 evaluable procedures. Among previously treated patients (PTPs) with >50 exposure days (EDs) and FVIII≤2%, three (0.75%) developed low-titre inhibitors. Two of these subjects had a positive inhibitor history; thus, the incidence of de novo inhibitor formation in PTPs with FVIII≤2% and no inhibitor history was 1/348 (0.29%; 95% CI, 0.01-1.59%). A PTP with moderate haemophilia developed a low-titre inhibitor. High-titre inhibitors were reported in a PTP with mild disease (following surgery), a previously untreated patient (PUP) with moderate disease (following surgery) and a PUP with severe disease. The favourable benefit/risk profile of rAHF-PFM previously documented in prospective clinical trials has been extended to include a broader range of haemophilia patients, many of whom would have been ineligible for registration studies.


Subject(s)
Blood Coagulation Factor Inhibitors/analysis , Factor VIII/therapeutic use , Hemophilia A/drug therapy , Adolescent , Adult , Child , Child, Preschool , Factor VIII/adverse effects , Female , Hemophilia A/blood , Hemorrhage/prevention & control , Humans , Male , Middle Aged , Product Surveillance, Postmarketing , Recombinant Proteins , United States
16.
J Thromb Haemost ; 8(9): 1986-93, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20492463

ABSTRACT

BACKGROUND: von Willebrand factor (VWF) variant c.2771G>A; p.R924Q has been described as a benign polymorphism or a possible marker for a null allele and been associated with mild bleeding phenotypes. It was identified in several patients in recent type 1 von Willebrand disease (VWD) studies. OBJECTIVES: To determine whether the p.R924Q allele contributes to reduced VWF levels and type 1 VWD. METHODS: One thousand one hundred and fifteen healthy controls and 148 index cases from the MCMDM-1VWD study were genotyped for c.2771G>A; VWF and FVIII levels were analyzed in ABO blood group stratified individuals and the p.R924Q variant was expressed in 293 EBNA cells. RESULTS: c.2771G>A was present in six index cases, five of whom had a second VWF variant which probably contributed to the phenotype. A common core haplotype identified in families, which included the rare G allele of c.5843-8C>G, was present in the majority of 35 c.2771G>A heterozygous controls. c.2771G>A contributed about 10% variance in VWF and FVIII levels in controls and 35% variance when co-inherited with blood group O. Recombinant p.R924Q VWF had no effect on in vitro expression and heterozygous family members had normal VWF-FVIII binding and normal clearance of VWF and FVIII. CONCLUSIONS: The allele bearing c.2771A leads to reductions in VWF and FVIII levels particularly in combination with blood group O. Its inheritance alone may be insufficient for VWD diagnosis, but it appears to be associated with a further VWF level reduction in individuals with a second VWF mutation and it contributes to population variance in VWF and FVIII levels.


Subject(s)
Arginine/genetics , Factor VIII/genetics , Glutamine/genetics , von Willebrand Diseases/genetics , von Willebrand Factor/genetics , ABO Blood-Group System , Alleles , Case-Control Studies , Founder Effect , Genetic Variation , Genotype , Heterozygote , Humans , Mutation , Phenotype , Recombinant Proteins/chemistry , von Willebrand Factor/chemistry
17.
Transfus Med ; 20(1): 48-61, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19778318

ABSTRACT

Solvent-detergent (S/D) viral inactivation was recently adapted to the treatment of single plasma donations and cryoprecipitate minipools. We present here a new process and a new bag system where the S/D reagents are removed by filtration and the final products subjected to bacterial (0.2 microm) filtration. Recovered and apheresis plasma for transfusion (FFP) and cryoprecipitate minipools (400 +/- 20 mL) were subjected to double-stage S/D viral inactivation, followed by one oil extraction and a filtration on a S/D and phthalate [di(2-ethylhexyl) phthalate (DEHP)] adsorption device and a 0.2 microm filter. The initial and the final products were compared for visual appearance, blood cell count and cell markers, proteins functional activity, von Willebrand factor (VWF) multimers and protein profile by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Tri (n-butyl) phosphate (TnBP) was quantified by gas chromatography and Triton X-45 and DEHP by high-performance-liquid chromatography (HPLC). General safety tests were by 6.5 mL/kg intravenous injection in rats. The treated plasmas and cryoprecipitates were very clear and the protein content and functionality, VWF multimers and SDS-PAGE profiles were well preserved. TnBP and Triton X-45 were < 1 and <25 ppm, respectively, and DEHP (about 5 ppm) was less than it was in the starting materials. Blood cell counts and CD45, CD61 and glycophorin A markers were negative. There was no enhanced toxicity in rats. Thus, plasma and cryoprecipitate can be S/D-treated in this new CE-marked disposable integral processing system under conditions preserving protein function and integrity, removing blood cells, S/D agents and DEHP, and ensuring bacterial sterility. This process may offer one additional option to blood establishments for the production of virally inactivated plasma components.


Subject(s)
Blood Component Removal/methods , Blood Preservation/instrumentation , Cryopreservation/instrumentation , Factor VIII , Fibrinogen , Plasma , Virus Inactivation , Animals , Blood Cell Count , Blood Protein Electrophoresis , Blood Proteins/analysis , Chromatography, High Pressure Liquid , Detergents/analysis , Diethylhexyl Phthalate/analysis , Female , Filtration , Humans , Male , Octoxynol/analysis , Organophosphates/analysis , Rats , Rats, Sprague-Dawley , Solvents/analysis , Sorption Detoxification
18.
Thromb Haemost ; 103(2): 351-9, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20024491

ABSTRACT

Thromboelastography methods have been used to predict or monitor treatment of haemophilia patients with recombinant activated factor VII (rFVIIa). However, neither of the two thromboelastographic methods (ROTEM and TEG) has as yet been validated. This multi-centre, randomised trial compared both methods in terms of intra- and inter- patient variability following in vivo and ex vivo rFVIIa administration to haemophilia A and B patients with and without inhibitors. Patients ((3)16 years old) received the same intravenous rFVIIa dose (45, 90 or 180 microg/kg) twice, 1-12 weeks apart. Blood samples were collected pre-dose and 15, 60, 120 and 240 minutes post-dose for ROTEM and TEG analysis. Pre-dose samples were also spiked ex vivo with rFVIIa (0.6, 1.2 or 2.4 microg/ml), to correspond to the three in vivo doses. Twenty-six haemophilia A and four haemophilia B patients were enrolled. A significant treatment effect was observed with in vivo rFVIIa (p<0.05) with more pronounced effects in inhibitor (n=14) versus non-inhibitor (n=16) patients. There was a strong positive correlation between ROTEM and TEG parameters. Intra- and inter-patient variation was large for all thromboelastography parameters at all time points and rFVIIa doses. Intra-patient variation was generally lower for non-inhibitor than inhibitor patients, and lower following ex vivo spiking versus in vivo rFVIIa administration. In conclusion, there was a clear effect of rFVIIa on all thromboelastography parameters, but the large intra- and inter-patient variability following in vivo rFVIIa administration renders the use of our method unsuitable for dose-response prediction for haemophilia patients in the clinical setting.


Subject(s)
Factor VIIa/administration & dosage , Hemophilia A/drug therapy , Thrombelastography/methods , Adolescent , Dose-Response Relationship, Drug , Factor VIIa/pharmacokinetics , Factor VIIa/pharmacology , Humans , Reproducibility of Results , Thrombelastography/standards , Treatment Outcome
19.
J Thromb Haemost ; 7(8): 1304-12, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19566550

ABSTRACT

BACKGROUND: Candidate von Willebrand factor (VWF) mutations were identified in 70% of index cases in the European study 'Molecular and Clinical Markers for the Diagnosis and Management of type 1 von Willebrand Disease'. The majority of these were missense mutations. OBJECTIVES: To assess whether 14 representative missense mutations are the cause of the phenotype observed in the patients and to examine their mode of pathogenicity. METHODS: Transfection experiments were performed with full-length wild-type or mutant VWF cDNA for these 14 missense mutations. VWF antigen levels were measured, and VWF multimer analysis was performed on secreted and intracellular VWF. RESULTS: For seven of the missense mutations (G160W, N166I, L2207P, C2257S, C2304Y, G2441C, and C2477Y), we found marked intracellular retention and impaired secretion of VWF, major loss of high molecular weight multimers in transfections of mutant constructs alone, and virtually normal multimers in cotransfections with wild-type VWF, establishing the pathogenicity of these mutations. Four of the mutations (R2287W, R2464C, G2518S, and Q2520P) were established as being very probably causative, on the basis of a mild reduction in the secreted VWF or on characteristic faster-running multimeric bands. For three candidate changes (G19R, P2063S, and R2313H), the transfection results were indistinguishable from wild-type recombinant VWF and we could not prove these changes to be pathogenic. Other mechanisms not explored using this in vitro expression system may be responsible for pathogenicity. CONCLUSIONS: The pathogenic nature of 11 of 14 candidate missense mutations identified in patients with type 1 VWD was confirmed. Intracellular retention of mutant VWF is the predominant responsible mechanism.


Subject(s)
Mutation , von Willebrand Factor/genetics , Animals , COS Cells , Chlorocebus aethiops , Humans , Mutant Proteins , Mutation, Missense , Phenotype , Protein Multimerization , Transfection , von Willebrand Diseases/genetics , von Willebrand Factor/metabolism
20.
J Thromb Haemost ; 6(9): 1494-9, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18627444

ABSTRACT

BACKGROUND: Inherited afibrinogenemia is a rare autosomal recessive disorder characterized by the absence or trace amounts of plasma fibrinogen inducing varying bleeding tendencies. Little is known about the pharmacokinetics of plasma-derived fibrinogen concentrates used in the treatment of afibrinogenemic patients. OBJECTIVE: This open, prospective, multicenter study assessed the pharmacokinetic and pharmacodynamic profiles of FIBRINOGENE T1 (FGT1; LFB, Les Ulis, France), a human fibrinogen concentrate treated with three specific biological safety steps. PATIENTS/METHODS: Five adult patients with congenital afibrinogenemia received a single infusion of 0.06 g kg(-1) of FGT1. Plasma samples drawn up to day 14 were assayed for fibrinogen antigen and activity and for coagulation parameters in a central laboratory. RESULTS: Fibrinogen antigen and activity were similar and highly correlated, with very low between-patient variability for pharmacokinetic parameters. Fibrinogen levels increased rapidly and significantly, with a mean plasma concentration of 1.39 g L(-1) being achieved 1 h after the end of the infusion, leading to almost complete in vivo recovery (94%). The mean half-life was 3.4 days, with slow linear elimination, and the distribution was mainly restricted to the vascular compartment. Coagulation parameters were normalized after the infusion and during the following 6-10 days. FGT1 was well tolerated overall. CONCLUSIONS: FGT1 behaves like natural functional fibrinogen, and its pharmacokinetic properties are in line with those expected from a fibrinogen concentrate. Our findings suggest that FGT1 can restore efficient hemostasis in afibrinogenemic patients, and predict good clinical efficacy.


Subject(s)
Fibrinogen/pharmacology , Fibrinogen/pharmacokinetics , Adult , Afibrinogenemia/drug therapy , Aged , Area Under Curve , Fibrinogen/adverse effects , Fibrinogen/analysis , Fibrinogen/therapeutic use , Half-Life , Humans , Middle Aged
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