Outcome measures in European patients with haemophilia: Survey of implementation in routine clinical practice, perception of relevance and recommendations by European treaters in the EHTSB.

INTRODUCTION: This study was conducted to evaluate the current implementation of outcome measures in routine clinical haemophilia practice and to explore and appreciate the perception of the relevance of such measures by treaters. METHODS: A survey was completed by 19 of the 26 physicians involved in the European Haemophilia Therapy Strategy Board (EHTSB). Employing an extensive inventory of outcome measures used in patients with haemophilia, information was collected about the frequency of data collection and the subjective appreciation of their importance during clinic review. RESULTS: The survey revealed that most treaters currently collect data that are mainly related to the haemostatic treatment (consumption of concentrates) and the bleeding symptoms (number and location of bleeds) in a non-uniform and non-standardized way. By contrast, functional, physical and quality of life scorings are rarely used and show considerable heterogeneity between treaters. Also, many disparities emerged between practice and perception, in particular quality of life data that are perceived as being important but for most of the time are not collected. CONCLUSIONS: This survey represents, in our view, the first attempt to evaluate the actual utilization of outcome measures in haemophilia care. While the value of outcome measures is appreciated, they are not assessed regularly. Therefore, there is a need to include appropriate performance indicators (outcome measures) of haemophilia care in routine clinical practice. Consensus recommendations to provide a framework for achieving this aim are provided.

Protein modelling to understand FGB mutations leading to congenital hypofibrinogenaemia.

INTRODUCTION: Congenital hypofibrinogenaemia is a quantitative fibrinogen disorder characterized by proportionally decreased levels of functional and antigenic fibrinogen. Mutations accounting for quantitative fibrinogen disorders are relatively frequent in the conserved COOH-terminal globular domains of the γ and Bß chains. The latter mutations are of particular interest since the Bß-chain is considered the rate-limiting chain in the hepatic production of the fibrinogen hexamer. AIM: The aim of this study was to study the molecular pattern of four patients with congenital hypofibrinogenaemia. METHODS: Four novel fibrinogen Bß-chain mutations leading to congenital hypofibrinogenaemia were identified in four women with heterogeneous symptoms. The human fibrinogen beta chain precursor protein sequence (P02675) was obtained from the UniProt database. The resulting models were analysed using swisspdbviewer 4.1.0. RESULTS: Three patients were heterozygous for different missense mutations located in the highly conserved ß nodule: c.882G>C:Arg294Ser (Arg264Ser), c.1298G>T:Trp433Leu (Trp403Leu) and c.1329C>G:Asn443Lys (Asn413Lys). Modelling analyses predicted major structural modifications likely to result in impaired fibrinogen secretion. One patient was heterozygous for an intron 7 donor splice mutation (c.1244 + 1G>A), leading to the complete abolishment of the donor site. CONCLUSIONS: Protein modelling of new causative mutations and comparison of molecular, biochemical and clinical data continue to yield valuable information on the development and course of fibrinogen disorders as well as on the choice of the most appropriate treatments.

Fibrinogen Mahdia: A congenitally abnormal fibrinogen characterized by defective fibrin polymerization.

INTRODUCTION: Congenital dysfibrinogenemia is a rare qualitative fibrinogen deficiency. Molecular defects that result in dysfibrinogenemia are usually caused by mutations which affect fibrinopeptide release, fibrin polymerization, fibrin cross-linking or fibrinolysis. AIM: Here, we investigated the genetic basis of hypodysfibrinogenemia in two Tunisian siblings with major bleeding. METHODS: Coagulation-related tests were performed on the patients and their family members. Functional analysis was performed in plasma fibrinogen to characterize fibrin polymerization. The sequences of fibrinogen genes were amplified and analysed by sequencing. RESULTS: Coagulation studies revealed a reduced functional and a borderline low antigenic fibrinogen plasma levels with prolonged thrombin and activated partial thromboplastin times. The fibrinogen is also characterized by a markedly impaired polymerization and could incorporate into fibrin fibres to a smaller extent (22%). Mutational screening disclosed a heterozygous single nucleotide deletion (G) at c.1025, resulting in a frameshift mutation (AαGly323GlufsX79) that is predicted to delete a part of the αC-domain containing some of the FXIII cross-linking sites. Both the normal and the aberrant Aα-chain (approximately 43 kDa) were detected by electrophoretic analysis in the patients. CONCLUSION: The new dysfunctional fibrinogen, Mahdia variant, describes its impact on fibrin assembly after the loss of the αC domains which are involved in the lateral aggregation of protofibrils. The study confirms that the truncated Aα-chain could be incorporated into mature fibrinogen molecules.

Management of congenital quantitative fibrinogen disorders: a Delphi consensus.

INTRODUCTION: No evidence-based guidelines for the management of patients suffering from afibrinogenaemia and hypofibrinogenaemia are available. AIM AND METHOD: The aim of this study was to harmonize patient's care among invited haemophilia experts from Belgium, France and Switzerland. A Delphi-like methodology was used to reach a consensus on: prophylaxis, bleeding, surgery, pregnancy and thrombosis management. RESULTS: The main final statements are as follows: (i) a secondary fibrinogen prophylaxis should be started after a first life-threatening bleeding in patients with afibrinogenaemia; (ii) during prophylaxis the target trough fibrinogen level should be 0.5 g L-1 ; (iii) if an adaptation of dosage is required, the frequency of infusions rather than the fibrinogen amount should be modified; (iv) afibrinogenaemic patients undergoing a surgery at high bleeding risk should receive fibrinogen concentrates regardless of the personal or family history of bleeding; (v) moderate hypofibrinogenaemic patients (i.e. ≥0.5 g L-1 ) without previous bleeding (despite haemostatic challenges) undergoing a surgery at low bleeding risk may not receive fibrinogen concentrates as prophylaxis; (vi) monitoring the trough fibrinogen levels should be performed at least once a month throughout the pregnancy and a foetal growth and placenta development close monitoring by ultrasound is recommended; (vii) fibrinogen replacement should be started concomitantly to the introduction of anticoagulation in afibrinogenaemic patients suffering from a venous thromboembolic event; and (viii) low-molecular-weight heparin is the anticoagulant of choice in case of venous thromboembolism. CONCLUSION: The results of this initiative should help clinicians in the difficult management of patients with congenital fibrinogen disorders.

Can the phenotype of inherited fibrinogen disorders be predicted?

Congenital fibrinogen disorders are rare diseases affecting either the quantity (afibrinogenaemia and hypofibrinogenaemia) or the quality (dysfibrinogenaemia) or both (hypodysfibrinogenaemia) of fibrinogen. In addition to bleeding, unexpected thrombosis, spontaneous spleen ruptures, painful bone cysts and intrahepatic inclusions can complicate the clinical course of patients with quantitative fibrinogen disorders. Clinical manifestations of dysfibrinogenaemia include absence of symptoms, major bleeding or thrombosis as well as systemic amyloidosis. Although the diagnosis of any type of congenital fibrinogen disorders is usually not too difficult with the help of conventional laboratory tests completed by genetic studies, the correlation between all available tests and the clinical manifestations is more problematic in many cases. Improving accuracy of diagnosis, performing genotype, analysing function of fibrinogen variants and carefully investigating the personal and familial histories may lead to a better assessment of patients' phenotype and therefore help in identifying patients at increased risk of adverse clinical outcomes. This review provides an update of various tests (conventional and global assays, molecular testing, fibrin clot analysis) and clinical features, which may help to better predict the phenotype of the different types of congenital fibrinogen disorders.

Rare coagulation disorders: fibrinogen, factor VII and factor XIII.

Rare coagulation disorders (RCDs) include the inherited deficiencies of fibrinogen, factor (F) II, FV, combined FV and VIII, FVII, FX, combined FVII and X, FXI, FXIII and combined congenital deficiency of vitamin K-dependent factors (VKCFDs). Despite their rarity, a deep comprehension of all these disorders is essential to really understand haemostasis. Indeed, even if they share some common features each RCD has some particularity which makes it unique. In this review, we focus on three disorders: fibrinogen, FVII and FXIII.

Hypertension, haematuria and renal functioning in haemophilia - a cross-sectional study in Europe.

BACKGROUND AND OBJECTIVES: This cross-sectional, epidemiological study sought to assess the prevalence and extent of potential risk factors for hypertension, particularly renal function related to haematuria and their associations in people with haemophilia. METHODOLOGY: Demographic and medical data were collected at a single time-point in patients with haemophilia over 40 years of age from 16 European centres. Associations with diagnosis of hypertension were tested in univariate and multivariate analyses. RESULTS: We enrolled 532 patients (median age 52 years, range 40-98) with haemophilia A (n = 467) or haemophilia B (n = 65). Haemophilia was severe (<0.01 IU mL-1 ) in 313 patients (59%). Hypertension was diagnosed in 239 patients (45%). In multivariate analyses, age and body mass index (BMI) were significantly and independently associated with hypertension (adjusted odds ratio (OR) 18.1, P < 0.001, in elderly patients and OR = 25.1, P < 0.001, in patients with BMI >30 kg m-2 ). Estimated glomerular filtration rate (eGFR) <70 mL min-1 (OR = 2.7, P = 0.047) was significantly associated with hypertension, but mean eGFR was significantly higher for severe than mild haemophilia. Further variables with OR > 2.8 were diabetes (OR = 2.8, P = 0.04), coronary artery disease (OR = 3.3, P = 0.052) and family history of hypertension (OR = 4.4, P < 0.001). Neither severity of haemophilia nor history of haematuria was significantly associated with hypertension in univariate or multivariate analyses. CONCLUSION: As in the general population, age and BMI were major risk factors for hypertension in people with haemophilia. Renal dysfunction was associated with hypertension, but the prevalence of renal dysfunction was not extensive and furthermore not significantly correlated with haematuria. The associations of other variables with hypertension require further studies to confirm causal relationships over time.

Hypofibrinogenemia and liver disease: a new case of Aguadilla fibrinogen and review of the literature.

INTRODUCTION: Fibrinogen storage disease (FSD) is characterized by hypofibrinogenemia and hepatic inclusions due to impaired release of mutant fibrinogen which accumulates and aggregates in the hepatocellular endoplasmic reticulum. Liver disease is variable. AIM: We studied a new Swiss family with fibrinogen Aguadilla. In order to understand the molecular peculiarity of FSD mutations, fibrinogen Aguadilla and the three other causative mutations, all located in the γD domain, were modelled. METHOD: The proband is a Swiss girl aged 4 investigated because of fatigue and elevated liver enzymes. Protein structure models were prepared using the Swiss-PdbViewer and POV-Ray software. RESULTS: The proband was found to be heterozygous for fibrinogen Aguadilla: FGG Arg375Trp. Familial screening revealed that her mother and maternal grandmother were also affected and, in addition, respectively heterozygous and homozygous for the hereditary haemochromatosis mutation HFE C282Y. Models of backbone and side-chain interactions for fibrinogen Aguadilla in a 10-angstrom region revealed the loss of five H-bonds and the gain of one H-bond between structurally important amino acids. The structure predicted for fibrinogen Angers showed a novel helical structure in place of hole 'a' on the outer edge of γD likely to have a negative impact on fibrinogen assembly and secretion. CONCLUSION: The mechanism by which FSD mutations generate hepatic intracellular inclusions is still not clearly established although the promotion of aberrant intermolecular strand insertions is emerging as a likely cause. Reporting new cases is essential in the light of novel opportunities of treatment offered by increasing knowledge of the degradation pathway and autophagy.

Congenital combined deficiency of coagulation factors VII and X--different genetic mechanisms.

Combined coagulation factor VII (FVII) and factor X (FX) deficiency (combined FVII/FX deficiency) belongs to the group of bleeding disorders in which both factors show reduced plasma activity. It may arise from coincidental inheritance of separate coagulation factor deficiencies or a common cause as large deletions comprising both gene loci. The F7 and F10 genes are located on the long arm of chromosome 13. Here, we describe 10 cases with combined FVII/FX deficiency representing both genetic mechanisms of occurrence. Genetic analyses included direct sequencing of the F7 and F10 genes and MLPA (multiplex ligation-dependent probe amplification) for detection of heterozygous large deletions. In four patients, the combined deficiency was due to a large deletion within the terminal end of chromosome 13. In the remaining six cases the deficiency resulted from coincidental inheritance of different genetic alterations affecting both genes independently. In most cases, the genetic defects were heterozygous, presenting with prolonged PT, normal aPTT and mild or no bleeding symptoms. Only in one case compound heterozygous mutations were detected in the F10, resulting in prolonged aPTT and a more severe bleeding phenotype. To avoid a misdiagnosis of combined FVII/FX deficiency, analyses of single factor activities have to be performed in all cases with prolonged PT even if aPTT is normal. Genetic analyses are substantial for correct prediction of an inheritance pattern and a proper genetic counselling.

Novel products for haemostasis.

The primary major issue in haemophilia treatment remains the development of inhibitors. Recently two novel bypassing products have been developed. First, a humanized bispecific antibody against FIXa and FX, termed hBS23, was produced utilizing these two molecules placed into a spatially appropriate position to mimic FVIIIa, and recently this mimetic activity and the pharmacokinetics of the original antibody were improved by engineering the charge properties of the variable region within the immunoglobulin. Using the new antibody, termed ACE910, a phase 1 study in 64 Japanese and Caucasian healthy adults was performed and data from this trial suggested that the product had medically acceptable safety and tolerability profiles. The other new bypassing agent is named MC710, and consists of a mixture of plasma-derived FVIIa and FX. Preclinical studies using in vitro and in vivo haemophilia B inhibitor monkey models indicated that the haemostatic effects of FVIIa and FX were enhanced by simultaneous administration. Results from phase I and II clinical studies suggested that MC710 had equal or greater pharmacokinetic (PK), pharmacodynamic (PD), efficacy and safety profiles than conventional bypassing agents in the treatment of joint bleeding in haemophilia patients with inhibitors. Another significant current issue in this context is the increased medical cost of conventional treatment due to the higher consumption of concentrates. Biosimilar products may offer advantages in these circumstances and may offer a less expensive alternative. Regulatory issues, however, together with acceptability of biosimilar materials and reimbursement policies as well as supply and demand incentives remain to be considered. Rare bleeding disorders (RBDs) have attracted less attention from the pharmaceutical industry than haemophilia or von Willebrand disease due to the limited number of patients involved. Many cases of this type have been treated, therefore, using fresh frozen plasma (FFP) or prothrombin complex concentrates (PCCs) which carry serious risks of infections, allergic reactions and fluid overload. Several specific plasma-derived or recombinant products including fibrinogen, FVIIa, FXI and FXIII have now become available, however, and a phase III clinical study of recombinant FXIIIa has recently been completed demonstrating safety and efficacy of substances of this nature.

Cancer detection and management in patients with haemophilia: a retrospective European multicentre study.

Lymphomas or hepatocarcinomas related to blood-borne transmitted diseases are well-known malignancies in persons with haemophilia (PWH). However, rising life expectancy has increased the number of PWH suffering from other malignancies. This study aimed to collect cancer occurrence data in PWH followed in five European haemophilia treatment centres (Brussels, Geneva, Marseille, Montpellier and Paris-Bicêtre) over the last 10 years and to analyse some particular features of cancer occurring in PWH. In total, 45 malignancies were diagnosed in 1067 PWH. The most common malignancies were hepatocellular carcinoma (12/45) and urogenital tract tumours (9/45). Bleeding at presentation or changes in bleeding pattern was indicative of cancer in four patients. Three patients with mild haemophilia developed anti-factor VIII inhibitors after intensive substitution therapy prior to surgery or invasive procedures. There was no bleeding associated with chemotherapy or radiotherapy. A few bleeding complications occurred following invasive (3/39) or surgical procedures (2/27) as a result of insufficient hemostatic coverage or in spite of adequate substitution. No bleeding was noted after liver or prostate biopsies. Following cancer diagnosis, five patients were switched from on-demand to prolonged prophylaxis substitution. In the majority of cases, the standard cancer treatment protocol was not modified on account of concomitant haemophilia. Thus, oncological treatments are not contraindicated and should not be withheld in PWH assuming that adequate haemostasis correction is undertaken. As shown by our study results, a change in bleeding pattern in adult PWH should raise suspicion of a malignancy. Intensive substitution must be considered a risk factor for inhibitor development.

Applicability of the European Society of Cardiology guidelines on management of acute coronary syndromes to people with haemophilia - an assessment by the ADVANCE Working Group.

There are no evidence-based guidelines for antithrombotic management in people with haemophilia (PWH) presenting with acute coronary syndrome (ACS). The aim of the study was to review the current European Society of Cardiology guidelines, and to consider how best they should be adapted for PWH. Structured communication techniques based on a Delphi-like methodology were used to achieve expert consensus on key aspects of clinical management. The main final statements are as follows: (i) ACS and myocardial revascularization should be managed promptly by a multidisciplinary team that includes a haemophilia expert, (ii) each comprehensive care centre for adult PWH should have a formal clinical referral pathway with a cardiology centre with an emergency unit and 24 h availability of percutaneous coronary intervention (PCI), (iii) PCI should be performed as soon as possible under adequate clotting factor protection, (iv) bare metal stents are preferred to drug-eluting stents, (v) anticoagulants should only be used in PWH after replacement therapy, (vi) minimum trough levels should not fall below 5-15% in PWH on dual antiplatelet therapy, (vii) the duration of dual antiplatelet therapy after ACS and PCI should be limited to a minimum, (viii) the use of GPIIb-IIIa inhibitors is not recommended in PWH other than in exceptional circumstances, (ix) the use of fibrinolysis may be justified in PWH when primary PCI (within 90 min) is not available ideally under adequate clotting factor management. It is hoped that the results of this initiative will help to guide optimal management of ACS in PWH.

Obstetrical antiphospholipid syndrome: from the pathogenesis to the clinical and therapeutic implications.

Antiphospholipid syndrome (APS) is an acquired thrombophilia with clinical manifestations associated with the presence of antiphospholipid antibodies (aPL) in patient plasma. Obstetrical APS is a complex entity that may affect both mother and fetus throughout the entire pregnancy with high morbidity. Clinical complications are as various as recurrent fetal losses, stillbirth, intrauterine growth restriction (IUGR), and preeclampsia. Pathogenesis of aPL targets trophoblastic cells directly, mainly via proapoptotic, proinflammatory mechanisms, and uncontrolled immunomodulatory responses. Actual first-line treatment is limited to low-dose aspirin (LDA) and low-molecular weight heparin (LMWH) and still failed in 30% of the cases. APS pregnancies should be a major field in obstetrical research, and new therapeutics are still in progress.

[New oral anticoagulants: from theory to practice]. / Hémostase. Nouveaux anticoagulants oraux: de la théorie à la pratique.

Physicians are confronted with many new antithrombotic drugs, either antiplatelet agents or new oral anticoagulants (NOAC). Targets of NOAC are specific (either anti-IIa or antiXa) and clinical studies have shown that NOAC are as efficacious and as safe as "old" anticoagulants (heparin, low molecular weight heparin, vitamin K antagonists); moreover they present some advantages. Indeed, NOAC have a wide therapeutic window and do not require laboratory monitoring. Therefore, it is very tempting to prescribe them on a large scale basis in patients at risk or having thromboembolic diseases. However, things are not so simple in the day-to-day practice and this review aims at answering in a brief and simplified manner to some questions.

[Thrombotic risk in myeloproliferative neoplasms: what the general practitioner needs to know]. / Risque thrombotique en cas de néoplasies myéloprolifératives: ce que devrait savoir le médecin praticien.

Polycythaemia vera, essential thrombocythemia and primary myelofibrosis are stem cell-derived clonal haemopathies classified in the group of myeloproliferative neoplasms. Their clinical course may be complicated by both arterial and venous (sometimes in unusual sites) thrombotic events. Although general risk factors contribute to the prevalence of thrombotic events in this population, some other risk factors are specifically associated with the myeloproliferative neoplasms. The treatment options are aspirin, anticoagulation, cytoreduction and phlebotomies.

Anti-apolipoprotein A-1 IgG in patients with myocardial infarction promotes inflammation through TLR2/CD14 complex.

OBJECTIVES: Toll-like receptor (TLR)-mediated vascular inflammation, inducible by - amongst other factors - auto-antibodies, is increasingly recognized as a potential mediator of cardiovascular disease. We investigated whether anti-apolipoprotein (Apo)A-1 IgG was associated with a pro-inflammatory cytokine profile in myocardial infarction (MI) patients and whether anti-ApoA-1 IgG elicited a pro-inflammatory response by activating TLRs. METHODS: As surrogate markers of atherosclerotic plaque vulnerability, interleukin (IL)-6, tumour necrosis factor (TNF)-α, matrix metalloproteinase (MMP)-9 and MMP-3 levels were assessed in 221 consecutive MI patients. Using human monocyte-derived macrophages (HMDMs) we investigated (i) the anti-ApoA-1 IgG interaction with TLRs using proximity ligation assay and (ii) anti-ApoA-1 IgG-dependent IL-6/TNF-α production. TLR involvement was further confirmed using HEK293-Blue TLR-2/-4 cells and by computational docking simulations. RESULTS: In MI patients, anti-ApoA-1 IgG positivity was associated with higher levels of IL-6, TNF-α and MMP-9, but lower MMP-3 levels. In in vitro experiments, anti-ApoA-1 antibodies bound to HDMDs in a TLR2-dependent manner, resulting in nuclear translocation of NFκB and a significant increase in TNF-α and IL-6 production. Subsequent functional studies highlighted the importance of CD14 as co-receptor in the anti-ApoA-1 IgG-TLR2-induced cytokine production. Additional bioinformatic studies identified structural homologies between TLR2 and ApoA-1, which may explain the observed cross-reactivity between antibodies against these two molecules. CONCLUSIONS: Anti-ApoA-1 IgG positivity in MI is associated with a high-risk cytokine profile. These auto-antibodies promote inflammation by stimulating the TLR2/CD14 receptor complex, probably because of molecular mimicry, which may contribute to atherosclerosis-related complications in patients.

Recommendations for assessment, monitoring and follow-up of patients with haemophilia.

Over the last few decades, clinical follow-up of patients with haemophilia has become more complex as a result of the introduction of new treatment strategies, the presence of comorbidities related to haemophilia or ageing, as well as the emergence of new tools to evaluate the medical and social consequences of haemophilia. This publication describes the parameters and information that should be documented and the tests, examinations and interventions required for optimal follow-up of a patient with haemophilia. In the absence of formal studies, the present recommendations have been established as result of a series of consensus meetings in the frame of the European Haemophilia Therapy Standardization Board (EHTSB). The following 11 domains were identified: Baseline information, Current status, Treatment, Inhibitor status, Bleeding, Joint status and pain, Comorbidities, Dental care, Physical activities, Social participation and Quality of life. For each domain, details are proposed for the relevant parameters to be captured and monitored as well as the relevant tools that facilitate data collection. Adopting these recommendations should help the individual care of patients and, even though this is not the primary objective of this article, it should also help at national and international level to shape a new approach to haemophilia by working towards a more standardized outcome assessment. Greater standardization should have implications for data collection, improvements in treatment evaluation and optimizing resources.

[New anticoagulants: better knowledge, better prescriptions]. / Hémostase. Nouveaux anticoagulants: bien les connaître pour bien les prescrire.

New oral anticoagulants are already or will be soon available. They have shown good efficacy and safety in various studies (prevention and treatment of venous thromboembolism, atrial fibrillation). Their arrival will probably modify the prescription of the current anticoagulant agents. However some precaution should be given in their use pending post marketing studies. Although these new drugs are intended to replace mostly vitamin K antagonists, a place will remain for "old" anticoagulants during the next years.

Management of acute haemarthrosis in haemophilia A without inhibitors: literature review, European survey and recommendations.

Acute haemarthrosis is a frequent type of bleeding in individuals with haemophilia. Delayed and/or inadequate treatment can trigger a series of pathological changes within the joint, leading to a painful and disabling arthropathy. The early management of intra-articular bleeding has the potential to prevent chronic joint disease and may include a combination of factor replacement, rest, ice, rehabilitation and, in certain cases, joint aspiration. Little data are, however, available regarding the optimal management of acute haemarthrosis, especially with respect to replacement therapy and the use of adjunctive therapies (aspiration, avoidance of weight bearing and immobilization, as well as the use of anti-inflammatory medication and embolization). To provide more insight into the management of acute haemarthrosis in patients with haemophilia, a literature review was conducted. Concomitantly, current management was surveyed in 26 European haemophilia comprehensive care centres representing 15 different countries. The review highlights the need for future robust studies to better define the appropriate replacement therapy and the role of adjunctive therapies such as aspiration. The survey reveals much heterogeneity in the management of acute haemarthrosis across the EU. Within the constraints discussed, treatment recommendations are presented that reflect the literature, current practice and the clinical experience of the European Haemophilia Therapy Standardisation Board (EHTSB).

The role of prophylaxis in bleeding disorders.

SUMMARY: The rationale for long-term prophylaxis in more severe forms of von Willebrand's disease (VWD) is obvious, as mucosal bleeding and haemophilia-like joint bleeds resulting in chronic morbidity may occur. However, the experience with prophylactic treatment in this group is scanty. An international VWD Prophylaxis Network (VWD PN) was established in 2006. The VWD PN will investigate prophylaxis with retrospective and prospective studies. Eighteen centres in Europe and North America are recruiting patients and an additional 40 centres are preparing for or evaluating participation. In the absence of randomized prospective studies for most rare bleeding disorders, guidelines for prophylaxis are a subject of controversy. In situations where there is a strong family history of bleeding, long-term prophylaxis is administered in selected cases. Short intervals of prophylaxis can also be given before some surgeries or during pregnancy. The benefits of prophylaxis must be balanced by the risk of side effects. Therefore, it is essential to delineate its management in a specialized comprehensive care environment. In haemophilia, decades of clinical experience and numerous retrospective and, recently, prospective studies clearly demonstrate that prophylactic treatment is superior to on-demand treatment, regardless of whether the outcome is the number of joint- or life-threatening bleeds, arthropathy evaluated by X-ray or MRI, or quality of life measured by generic or haemophilia-specific instruments. Optimal prophylactic treatment should be started early in life (primary prophylaxis) but various options exist for the dose and dose interval. These depend on the objective of treatment in the individual patient, which, in turn, is dependent on resources in the health care system.