Abstract

The level of haemophilia care and the use of Factor Replacement Therapy varies enormously between countries on a global level. The level of care varies from below the minimal survival standard to an optimum standard of care. An optimum standard of care would involve treatment in a comprehensive care centre, provision of safe and efficacious replacement therapy, the availability of home therapy, treatment on a prophylactic basis to prevent joint damage and minimise bleeding and strong and effective cooperation between doctors and the haemophilia society on a national basis. In setting national objectives for care one should ensure that they are linked to the economy of the country and that they are realistic ,practicable and achievable especially in view of the current global economic turmoil. Care on a national level should focus both on resources required and organisational issues. In the current economic global climate, governments and funding authorities will be looking more critically at the cost of treatment of all medical conditions including haemophilia. We must ensure that haemophilia organisations and clinicians are adequately prepared to play a proactive role in the assessment of future haemophilia care. The move towards the use of Health Technology Assessments and other measures of cost effectiveness of haemophilia treatment will be discussed.

Brian O Mahony

Unravelling the complexities of Type 1 von Willebrand Disease. Said Enayat, Birmingham Children’s Hospital, UK.

Abstract

Although von Willebrand Disease (VWD) is now well described, many aspects of diagnosis of its different types have remained confusing and debateable. From its original description to present there have been three different classifications and in the last one it is still unclear about few of the minor types of VWD. From the beginning, at least type 1 VWD was thought to be the easiest to be diagnosed on the bases of reduced VWF antigen (VWF:Ag) below the normal level of about 0.5 U/ml. However, since the identification of the VWF gene, very few mutations were identified to be the causative agent of this type of VWD disorder.
The data from three multi-centre cohort studies from Canada, UK and Europe on type 1 VWD have had a great influence on revision of diagnosis, classification and management of this type of bleeding disorder. These studies have found that patients with low levels of VWF:Ag tend to have a mutation in the VWF gene and disease tends to be transmitted predictably within families. In patients with VWF levels close to the lower end of normal range, candidate mutations are found less often ABO blood group is a major important factor and the disease has a variable hereditability within the families. Diagnosis of patients with VWF:Ag levels between these two groups is still problematic. Further studies on mechanism of VWF synthesis, its post-translational modification, secretion and clearance are needed to resolve this. The findings from these studies have now provided a great help in management of VWD patients and facilitated genetic counselling within their families.

Catherine CoWomen and haemopilia: molecular diagnosis and new management of pregnancy in X linked disease.

Catherine Costa
CHU Henri Mondor APHP Laboratoire de Génétique Moléculaire, Génétique INSERM U955 équipe 11, Créteil, France.

Haemophilia is a frequent X-linked bleeding disorder caused by factor 8 (F8) haemophilia A or factor 9 (F9) hemophilia B gene defects. Diagnosis of haemophilia does not only rely on the molecular identification of the disease-causing mutation but still on Factor VIIIc or FIXc activity. The relevance for identification of the disease-causing mutation is first the diagnosis of carriers, second a help in predicting development of factor VIII inhibitors and least a better understanding of the structure–function relationship.
Identification of carriers is of major importance in genetic counselling. The pedigree study of the family allows identification of obligate carriers and women at risk. Factor VIII or IX activity are performed in women as well as molecular studies since about one third of carriers have normal activity. Identification of disease-causing mutations usually relies on extensive analysis of the coding sequence in index-cases, is suited to the type of haemophilia A or B and subsequently allows carrier status determination in at-risk women.The carrier status established prenatal diagnosis can be proposed to better take care of newborn and mother during delivery but also to reduce mothers’ anxiety.
However, in case of large deletions, or in absence of index case and in somatic mosaicism direct molecular diagnosis of carriers becomes difficult by conventional methods. Recent advance in new technologies can circumvent these problems.
Sampling for prenatal diagnosis uses invasive techniques. Chorionic villus sampling is the earliest procedure for foetal sex determination and molecular analysis of X-linked genetic disorders during the first trimester but it is associated with a risk of foetal loss. Non invasive procedure as ultrasound examination allows reliable foetal sex determination only during the second trimester. Cell-free foetal DNA circulating in maternal plasma offers a new possibility of non-invasive approach in prenatal diagnosis. It has recently been demonstrated that foetal gender determination can be achieved by maternal serum analysis during the first trimester of pregnancy. As a consequence, a new strategy for the management of prenatal diagnosis in X-linked genetic disorders such as haemophilia is now proposed. Foetal gender determination in maternal blood allows avoiding an invasive procedure for molecular analysis in 50% of the foetuses.

The Construction & Virtues of a National Database

Professor Frank Hill, Haematology Department
The Birmingham Children’s Hospital, Birmingham, UK

In 1997 Rosemary Biggs invited UK clinicians treating patients with haemophilia to meet. From this came a collaboration that resulted in a framework for a national Haemophilia Service. From 1969, these centres were submitting annual returns from their centre, which were compiled into a national annual report. By 1991 there was a computerised National Register of all patients with Inherited Bleeding Disorders set up at Oxford. The current National Haemophilia Database is at the Haemophilia Centre in Manchester and is managed by the UK Haemophilia Doctors Organisation (UKHCDO).

The importance of centre databases and their collection of data will be discussed, as well as the collection of data for a national haemophilia database. How this data can be used to plan haemophilia care both locally and nationally will be discussed, including the monitoring and recording of adverse events, which is an important function of a national data collection. The process of data standardisation and verification, patient and centre consents, remit of data collection and use of this information is central to having a successful national database. Essential to all of this is collaboration and co-operation between centres, as this facilitates the creation of working groups and the production of guidelines for patient investigation and treatment that is state of the art.

FGHH/PAM/26.02.2009

Future prospects for haemophilia treatment

Dr. Paul Giangrande, Consultant Haematologist and Director, Oxford Haemophilia and Thrombosis Centre (UK)

So far, the application of recombinant technology has been limited to simply copying the normal factor VIII and IX molecules. In the future, it is likely that modified molecules with enhanced properties such as reduced immunogenicity and increased half-life will be developed. Pegylation has been employed to produce preparations of factors VIII and IX as well as von Willebrand factor which have enhanced duration of action. This technology has also been applied to recombinant activated factor VII, with the aim of facilitating prophylaxis as the molecule appears to have a half-life in of the order of 19 hours. A subcutaneous formulation of rVIIa is undergoing clinical trial. Fusion to albumin has been developed as a alternative to pegylation. Binding of factor IX to monomeric immunoglobulin can also result in increased duration of activity by exploiting endothelial recycling. Other possible strategies for increasing the duration of activity of factor VIII in the circulation include generating forms of factor VIII with mutations at the sites which are the natural targets for specific proteolytic inactivation by activated protein C (APC) or factor IXa and Xa. Clearance of factor VIII in the circulation is normally mediated by low-density lipoprotein receptor-related protein (LRP), a hepatic clearance receptor with a broad ligand specificity. Suppression of the interaction between factor VIII and these catabolic receptors could thus theoretically prolong the half-life of factor VIII. Although there is no immediate prospect of oral preparations becoming available, a formulation for use as a nasal spray is a realistic target. This exploits the fact that certain compounds are able to open up the molecular “locks” which normally bind adjacent epithelial cells and thus permit intercellular transport across mucosal surfaces. The development of inhibitory antibodies in haemophilia remains a significant problem and the creation of less immunogenic molecules would be a welcome development. The major targets for binding of inhibitory antibodies are within the A2 and C2 domains of factor VIII. The creation of hybrid molecules containing substituted porcine sequences at specific points within these domains results in reduction of reactivity with antibodies. Non-anticoagulant polysaccharide derivatives of heparin such as fucoidan have been shown to inhibit tissue factor pathway inhibitor (TFPI). Such drugs may prove beneficial as adjunctive therapy and particularly for patients with inhibitors. The development of transgenic dairy animals also offers the potential for the production of production of recombinant products which can be extracted from their milk. Transgenic antithrombin is already clinical trials and factor IX molecule from pigs is also under development. Ultimately, gene therapy can be expected to cure the condition although this is not likely to be a realistic prospect for some twenty years. Six clinical trials in both haemophilia A and B have yielded promising results.

Health Status and Developing Hemophilia Care Program in Iranian Hemophilia Southern Iran

Mehran Karimi MD
Hematology Reaserch Center, Shiraz University of Medical Sciences, Iran
karimim@sums.ac.ir

Introduction:
More than 400000 people in the world have haemophilia, 115000 patients have been identified and more than 285000 remains undiagnosed or untreated, most of who live in developing countries.
Early and accurate diagnosis, safe therapeutic products and even prophylactic therapy are available to only 20% of patients, those who live in developed countries.
Financial resources limitations are the most reason for inadequate haemophilia care in 75% of haemophiliacs in these countries.
Medical care with prompt factor replacement for bleeding episodes allows these individuals to have normal function and life.
Life time treatment of persons with hemophilia needs a large amount of money.
The largest portion of patients’ cost is spent on their factor infusion.
In USA: the mean annual cost of care is $ 139000 from which factor VIII is about 72%
Iran has 7000 bleeding disorder patients where more than 500 of them live in Fars province, south of Iran.
The total cost of care of these patients including hemophilia and non- hemophilia care is paid by the Ministry of Health. We use 1.5 units of factors /capital in Iran
A haemophilia care program should be able to provide comprehensive medical care to the patient with haemophilia and the provision of such care is the ability to provide adequate hemostatic support to the haemophilic patients.
Development of such a program depends on the presence and commitment of the following elements:
1. Key medical and paramedical personels.
2. Recognition of the fact that haemophilia exists in a particular country or community.
3. Positive attitude toward haemophilia by society
For achieving the comprehensive haemophilia care program, we should consider the following issues:
1. Training of care providers and establishing care centers.
2. Accurate diagnosis and registration of persons with haemophilia.
Health status is defined as the ability to engage in every day behaviors necessary to maintain daily life and encompassing areas of physical, cognitive and social functioning.
Health status was assessed by staff members using a four item scale first used by the hemophilia utilization group study (HUGS).
Our results showed 65.9% had HUGS> 7
The average cost of care was $ 8510 which 99% of it was factor use and 1% non factor use.
In Conclusion, the lowest annual cost of care is with mild FVIII deficiency, no inhibitor, no arthropathy.
The patients had acceptable functional health: 65.9% had HUGS> 7, in comparison with 78.3% in USA
Health status is acceptable but not optimal comparing with developed countries.
Inappropriate distribution and usage of factors are challenging issues in Iran.

Management of Carriers with Hemophilia

Alison Street
Vice-President Medical, WFH
Alfred Hospital, Melbourne, Australia

Carriers of hemophilia may themselves have a bleeding disorder due to reduction of Factors VIII or IX, though most have adequate levels for safe hemostasis
Women who are known to be carriers, or at “risk” of being so, need to have the relevant plasma factor measured so that their own risk of bleeding at delivery, surgery or with trauma can be assessed and managed.
Definitive diagnosis of the carrier state in non-obligate carriers is made by genetic analysis
There are many medical and social issues for carriers and their care is best managed by a hematologist and other members of a comprehensive care team familiar with hemophilia. This may involve recognition of anemia and management of menorrhagia.
When a known or suspected hemophilia carrier is pregnant, she needs a care plan developed to be shared with all her clinicians. This is to ensure the most safe delivery for her with any surgical and analgesic/anesthetic procedures and for her male infant at risk of having hemophilia.

Importance of Molecular Genetic Analysis in Iranian Families with Congenital Bleeding Disorders

Inherited bleeding disorders such as haemophilia are caused by heterogeneous mutations involving a single gene. These disorders cannot be cured and they require continuous lifetime medical care which is very expensive. The financial burden becomes very heavy in countries such as Iran with limited resources for health care. Due to inadequate therapeutic materials and diagnostic facilities, bleeding disorders are generally perceived to be associated with crippling and disability.
On the other hand the hereditary nature of these disorders profoundly affects the entire family rather than merely the affected individual. Being a carrier has a particularly great impact on the future of sisters. Identification of carriers, antenatal diagnosis and genetic counseling are important aspects the care of bleeding disorders care and effective control of the disease. The provision of predictive tests is extremely important in the prevention of inherited disorders.
In Iran establishment of a centre with expertise in screening, DNA analysis and counseling along with haemostasis testing and mutation detection of congenital bleeding disorders is of fundamental importance. The Comprehensive Hemophilia Care Centre in Tehran has taken a leading role in the identification of mutations and carrier detection for congenital bleeding disorders for the whole country free of charge.
This presentation will describe the results of our five years practice in the molecular genetics laboratory and will highlight the importance of genetic services for developing countries in particular.

MOLECULAR CHARACTERIZATION OF IRANIAN PATIENTS WITH TYPE 3 VON WILLEBRAND DISEASE

Shirin Shahbazi 1, Reza Mahdian 2, Fereidoon A. Ala 3, Jean-Maurice Lavergne 1, Cécile V. Denis 1, Olivier D. Christophe 1
1 INSERM U770, Université Paris-Sud, Faculté de Médecine Paris-Sud, IFR93, Le Kremlin-Bicêtre, France.
2 Molecular Medecine Department, Pasteur Institute of Iran, Tehran, Iran.
3 Iranian Comprehensive Haemophilia Care Centre (ICHCC), Tehran, Iran.

Abstract
Introduction: Von Willebrand disease (VWD) type 3 is a rare but severe autosomal-recessive inherited bleeding disorder with a prevalence higher in certain locations where consanguineous marriages are more frequent.
Objective: The genetic defects causing recessive type 3 VWD in ten unrelated families from Iran have been investigated and the genetic heterogeneity among these patients was evaluated.
Methods and Results: All exons and their flanking regions of von Willebrand factor (VWF) gene were amplified by PCR and sequenced using specific primers. Eight patients were fully characterized at the molecular level. Six different gene alterations were identified. All the mutations caused null alleles, 3 being nonsense mutations (Q104X, Q793X, and E1981X), 2 possible splice site mutations (2431-1 GC and 1110-1 GA), 1 small deletion (3237delA). Three of them have not been described previously. Most patients were born from consanguineous marriages and all the patients were homozygous for their mutations.
Conclusions: Our results confirm that molecular defects in type 3 VWD are heterogeneous with mutations arising randomly within the entire gene.

MOLECULAR CHARACTERIZATION OF IRANIAN PATIENTS WITH TYPE 3 VON WILLEBRAND DISEASE

Shirin Shahbazi 1, Reza Mahdian 2, Fereidoon A. Ala 3, Jean-Maurice Lavergne 1, Cécile V. Denis 1, Olivier D. Christophe 1
1 INSERM U770, Université Paris-Sud, Faculté de Médecine Paris-Sud, IFR93, Le Kremlin-Bicêtre, France.
2 Molecular Medecine Department, Pasteur Institute of Iran, Tehran, Iran.
3 Iranian Comprehensive Haemophilia Care Centre (ICHCC), Tehran, Iran.

Abstract
Introduction: Von Willebrand disease (VWD) type 3 is a rare but severe autosomal-recessive inherited bleeding disorder with a prevalence higher in certain locations where consanguineous marriages are more frequent.
Objective: The genetic defects causing recessive type 3 VWD in ten unrelated families from Iran have been investigated and the genetic heterogeneity among these patients was evaluated.
Methods and Results: All exons and their flanking regions of von Willebrand factor (VWF) gene were amplified by PCR and sequenced using specific primers. Eight patients were fully characterized at the molecular level. Six different gene alterations were identified. All the mutations caused null alleles, 3 being nonsense mutations (Q104X, Q793X, and E1981X), 2 possible splice site mutations (2431-1 GC and 1110-1 GA), 1 small deletion (3237delA). Three of them have not been described previously. Most patients were born from consanguineous marriages and all the patients were homozygous for their mutations.
Conclusions: Our results confirm that molecular defects in type 3 VWD are heterogeneous with mutations arising randomly within the entire gene.