View clinical trials related to Hemophilia.
Filter by:There are large inter-individual differences in the bleeding pattern of patients with moderate or mild hemophilia. The major determinant of bleeding phenotype is the level of coagulant factor VIII or IX. In hemophilia A, studies addressing the association between factor VIII level and the clinical bleeding pattern yield conflicting results. In hemophilia B such studies have not yet been performed. The primary aim of this project is to analyze the association between factor VIII and factor IX levels and the bleeding phenotype. The secondary aim is to analyze potential differences in phenotype between hemophilia A and B. The project is a multicentre observational cohort study. We will include 500 patients with moderate or mild hemophilia A (FVIII 0.02-0.35 IU/mL) and 500 patients with moderate or mild hemophilia B (FIX 0.02-0.35 IU/mL) who are 12 to 55 years old. The main cohort study consists of clinical data collection, one blood sample and an online questionnaire for patients. Data will be collected on the nature and duration of all bleeding episodes, disease and treatment characteristics, physical activity level and musculoskeletal status. One blood withdrawal will be performed for centralized laboratory assays for FVIII or FIX levels (both one-stage and chromogenic assays) and genetic analysis for the most prevalent prothrombotic mutations. The online questionnaire for patients focuses on bleeds experienced in the past. A subset of 200 patients aged 24 years or older (100 with moderate or mild hemophilia A and 100 with moderate or mild hemophilia B) will be investigated in more detail by longitudinal data collection including analysis of physical joint status, MRI imaging of joints and biomarkers for joint damage. This longitudinal observation will consist of two time points that lie two years apart, allowing us to identify any changes that occur over the observed time period with respect to joint status.
The PROBE Phase-3 study will collect data on patient reported outcomes, burdens, and experiences in patients living with hemophilia. The investigators will perform comparisons among countries, within country over time, within country against national normative data.
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.
Background The treatment of haemophilia A and B has been revolutionized by the use of factor concentrate, both as prophylaxis and to treat bleeding episodes (on-demand treatment). However, despite its advantages, repeated treatment with factor concentrate can lead to development of inhibitors (antibodies) towards the coagulation factor in the concentrate. Another patient group in which the bleeding symptoms are difficult to treat because of inhibitors towards coagulation factors, most commonly FVIII, is patients with acquired haemophilia. Patients with high antibody titers exhibit a deficient or no response to factor concentrates and usually need treatment with bypassing agents, namely factor eight inhibitor bypassing agent (FEIBA®, Baxter) och recombinant activated factor VII (rFVIIa, Novo-Seven®, Novo Nordisk). The effect of the treatment cannot be accurately monitored by traditional coagulation tests. The aim of the study is to evaluate the utility of the global haemostatic methods in patients with haemophilia with inhibitors. The objective is to improve the monitoring of the treatment effect and thus increase the safety of the patient and the effectiveness of the treatment. Patients and methods Patients The primary cohort will consist of fifteen patients with inherited haemophilia with inhibitors as well as five adult patients with acquired haemophilia who are followed up at the Coagulation Department of the Karolinska University Hospital, Stockholm, Sweden. Blood samples will be collected from those patients at specific time points (see Design of the study) during the course of two years (for each patient). The treatment (type, dose, duration) will be determined by the treating physician. Methods (selection) - Thrombin generation (Calibrated Automated Thrombogram, CAT® and a commercial kit from Siemens®). - Overall haemostatic potential (OHP) Design of the study Timeframe for blood sampling: i) baseline (inclusion in the study), and ii) prior and after administration of bypassing agents to either treat bleeding symptoms or before an invasive procedure or as prophylaxis. Data analysis The variations in coagulation markers measured as described above (Methods) will be associated to the clinical symptoms (bleeding), the level of coagulation factors (if measurable) and the titers of the inhibitors.