Desmopressin (DDAVP) in the Treatment of Bleeding Disorders: The First 20 Years

How I treat patients with von Willebrand disease

Von Willebrand disease (vWD) is a frequent inherited disorder of hemostasis that affects both sexes. Two abnormalities are characteristic of the disease, which is caused by a deficiency or a defect in the multimeric glycoprotein called von Willebrand factor: low platelet adhesion to injured blood vessels and defective intrinsic coagulation owing to low plasma levels of factor VIII. There are 2 main options available for the treatment of spontaneous bleeding episodes and for bleeding prophylaxis: desmopressin and transfusional therapy with plasma products. Desmopressin is the treatment of choice for most patients with type 1 vWD, who account for approximately 70% to 80% of cases. This nontransfusional hemostatic agent raises endogenous factor VIII and von Willebrand factor 3 to 5 times and thereby corrects both the intrinsic coagulation and the primary hemostasis defects. In patients with the more severe type 3 and in most patients with type 2 disease, desmopressin is ineffective or is contraindicated and it is usually necessary to resort to plasma concentrates containing both factor VIII and von Willebrand factor. Concentrates treated with virucidal methods should be preferred to cryoprecipitate because they are equally effective and are perceived as safer. (Blood. 2001;97:1915-1919)

A protocol for the dental management of von Willebrand's disease, haemophilia A and haemophilia B

A guide for the dental management of the three inherited bleeding disorders, von Willebrand's disease, haemophilia A and haemophilia B, was established jointly by the Institute of Medical and Veterinary Science Transfusion and Haemostasis Unit in conjunction with the Medically Compromised Dental Unit at the Adelaide Dental Hospital. This protocol was subjected to a successful trial for 24 months.

Effects of agents, used to treat bleeding disorders, on bleeding time prolonged by a very high dose of a direct thrombin inhibitor in anesthesized rats and rabbits

Melagatran is the active form of the oral, direct thrombin inhibitor, H 376/95, that is under evaluation in clinical trials for the prevention and treatment of thromboembolism. In this study, a single dose, calculated on body weight basis, of antifibrinolytic treatment, factor VIIa, factor VIII with and without von Willebrand factor (vWF), factor IX, activated (APCC) or nonactivated (PCC) prothrombin complex concentrates was given intravenously to rats and rabbits, in an attempt to reverse the prolonged bleeding time during intensive anticoagulation with melagatran (2 micromol/kg/h). The doses used were at or above human therapeutic doses. The cutaneous tail bleeding time in the rat, as well as the ear incision bleeding time and cuticle bleeding time, and the blood loss in the rabbit were used for evaluation of the hemostatic effects of these agents. In vivo Feiba (APCC) and Prothromplex-T (PCC) shortened the prolonged cutaneous bleeding times in rats (P<.05); Feiba and Autoplex (APCC) shortened the cutaneous bleeding times in rabbits (P<.05). In contrast, Prothromplex-T prolonged bleeding times and blood loss in the rabbits (P<.05). Ex vivo Feiba, Autoplex and NovoSeven (rF VIIa) significantly (P<.05) shortened the prolonged whole blood clotting time (WBCT). Prothromplex-T significantly prolonged WBCT, activated clotting time (ACT) and activated partial thromboplastin time (APTT). Feiba, Autoplex, and Prothromplex-T increased thrombin generation measured as increased thrombin-antithrombin complex (TAT) formation. In conclusion, APCCs were found to be the most effective agents for reversing bleeding time induced by a very high plasma concentration of melagatran. APCC and recombinant activated factor FVII (rF VIIa) effectively shortened the prolonged WBCT. Thus, stimulating thrombin generation with the use of APCC may counteract the anticoagulant effect observed with a very high dose of a thrombin inhibitor.

Interleukin 11 significantly increases plasma von Willebrand factor and factor VIII in wild type and von Willebrand disease mouse models

Interleukin (IL)-11 is a cytokine with thrombopoietic activity that has been shown to increase plasma von Willebrand factor (vWf) in preliminary clinical studies. This led to further evaluation of the effect of recombinant human (rh)IL-11 on vWf and factor VIII (FVIII) secretion. In vitro, rhIL-11 did not increase vWf production by cultured endothelial cells, which suggests an indirect mechanism. Also, in vivo, plasma vWf was not elevated in mice shortly after a single intravenous (IV) bolus injection of 250 or 1000 microg/kg rhIL-11. The effect of continuous exposure to rhIL-11 was accessed by treating wild type mice for 7 consecutive days with subcutaneous 250 microg/kg/d rhIL-11. Platelet counts increased by 25% and 40% after 4 and 7 days, respectively. Plasma vWf and FVIII levels increased 2-fold after 4 and 7 days. Surprisingly, no effect of rhIL-11 on vWf or FVIII messenger RNA was observed, which suggests that the regulation by rhIL-11 occurs after transcription. No increase in soluble P-selectin was observed after rhIL-11 treatment, indicating that platelet activation is not the source of elevated vWf. Similarly to wild type mice, vWf heterozygous mice responded to rhIL-11 treatment by a significant increase in platelet counts and vWf and FVIII levels. Importantly, in vWf-deficient mice, rhIL-11 also induced a significant increase in FVIII independent of vWf and was able to reduce skin bleeding time. These results suggest that a clinical evaluation of the effects of rhIL-11-induced vWf/FVIII elevation in maintaining hemostasis in mild hemophilia A or von Willebrand disease would be worthwhile.

Use of ristocetin cofactor activity in the management of von Willebrand disease

von Willebrand disease (vWD), the most common of the hereditary bleeding disorders, arises from quantitative or qualitative defects in von Willebrand factor (vWF). vWF is a multimeric plasma protein that plays a key role in primary and secondary haemostasis. In the current classification scheme, vWD is divided into six subtypes that are based on the nature of the vWF defect. Therapeutic strategies depend on the accurate identification of these subtypes. In most clinical situations, desmopressin is effective treatment for the great majority of patients with mild (type 1) disease, while replacement therapy with factor VIII/vWF concentrates that contain high levels of vWF activity is required for most type 2 and nearly all type 3 vWD patients. Several factor VIII/vWF replacement products are available, one of which (Humate P) has been approved for the treatment of vWD by the US Food and Drug Administration. Preliminary results of recent studies support the hypothesis that treatment with factor VIII/vWF concentrates based upon the content of vWF activity as reflected in the ristocetin cofactor assay is practicable, safe and efficacious. The establishment of optimal treatment regimens with respect to dose intensity and duration will require further study.

DDAVP (desmopressin; 1-deamino-cys-8-D-arginine-vasopressin) treatment in children with haemophilia B

We tested the response to desmopressin (1-deamino-cys-8-D-arginine-vasopressin; DDAVP) in four patients with haemophilia B [factor IX (F IX) at diagnosis 1.4-5%]. The activated partial thromboplastin time (aPTT) was significantly shortened in all patients. Although there was an up to 1.4-fold increase in F IX levels in three patients, maximal F IX activity remained below 10%. Much more prominent were the increases in F VIII (three- to fourfold), in von Willebrand factor antigen (VWF:Ag; 2.5-fold) and particularly in VWF collagen-binding activity (VWF:CBA; fivefold). These changes were reflected by the prophylactic efficacy of DDAVP for dental surgery. After pretesting, DDAVP could be a useful drug for reducing the need for plasma products for prevention of minor surgical bleeding in patients with mild to moderate haemophilia B.

Haemophilias: advances towards genetic engineering replacement therapy

Both haemophilia A and B are X-linked recessive disorders and therefore occur almost exclusively in males. The genes for both factors VIII and IX have been mapped to the distal end of the long arm of the X chromosome, bands Xq28 and Xq27.1, respectively. The Factor VIII gene comprises 186 kb DNA with 9 kb of exon of DNA which encodes an mRNA of nearly 9 kb. The Factor IX gene is 34 kb in length and the essential genetic information is present in eight exons which encode 1.6 kb mRNA. In gene therapy, genetic modification of the target cells can be either ex vivo or in vivo. The advantage of the ex vivo approach is that the genetic modification is strictly limited to the isolated cells. In the in vivo approach, the integrity of the target tissue is maintained but the major challenge is to deliver the gene to the target tissue. The use of improved retroviral and adenovirus-based vectors for gene therapy has produced clinically relevant levels of human factor VIII in mice and haemophilic dogs. If further improvements can increase the persistence of expression and decrease the immunological responses, phase I clinical trials in patients can be considered.

Monthly haemoptysis in a woman with platelet storage pool disease

A 26-year-old female with known platelet storage pool disease presented with a short history of recurrent haemoptysis. Initial investigations were unhelpful until the cyclical nature of the symptoms became apparent prompting the unusual diagnosis of pulmonary endometriosis to be made. This was subsequently confirmed on premenstrual CT scanning. The introduction of a specific hormonal therapy and multidisciplinary input was ultimately successful.

Haemophilia care in central Scotland 1980-94. I. Demographic characteristics, hospital admissions and causes of death

To estimate the resources required to manage patients with haemophilia in Scotland, we studied the demographic features, hospital admissions and causes of deaths for individuals with haemophilia A and B and von Willebrand disease, treated with blood products, during the period 1980-94 living in central Scotland. Data were obtained from 413 adults and children (93% ascertainment). The age distribution in 1980 revealed a paucity of individuals over 60 years but the number in this age group increased over the study period. Of those with haemophilia A and B, 63 and two respectively, became HIV positive. Hospital admissions rose from 103 to 168 per annum; the number of annual bed days utilized also increased, but there was marked annual fluctuation (790-1832). The rate of admission was greater for those with severe haemophilia A and this increased during the 15-year period mainly due to the clinical consequences of human immunodeficiency virus (HIV) and hepatitis C virus (HCV). The admission rate for haemophilia B was significantly lower than that for haemophilia A, and was similar for all degrees of severity of the disorder. Throughout the 15-year period the incidence of admissions for acute bleeds was constant, as was the average duration in hospital. For those with a factor VIII inhibitor, the rate of admission was about double the rate of those without an inhibitor, although the duration of hospital stay was similar for both groups. There were 61 deaths; the death rate increased during the study period principally due to HIV and HCV, and 12 patients died from haemorrhage. We conclude that: (i) the life expectancy for haemophiliacs in Scotland was generally increasing, although HIV and HCV caused increasing mortality and morbidity (as shown by the increase in hospital admissions); (ii) hospital bed usage for the treatment of acute bleeds continued to be required, but fluctuated greatly; and (iii) the clinical impression that haemophilia B is less clinically severe than haemophilia A is confirmed by objective data. The planning implications for haemophilia care in Scotland and similar countries are discussed.

Coagulation and Bleeding Disorders: Review and Update

Hemostasis is initiated by injury to the vascular wall, leading to the deposition of platelets adhering to components of the subendothelium. Platelet adhesion requires the presence of von Willebrand factor and platelet receptors (IIb/IIIa and Ib/IX). Additional platelets are recruited to the site of injury by release of platelet granular contents, including ADP. The “platelet plug” is stabilized by interaction with fibrinogen. In this review, I consider laboratory tests used to evaluate coagulation, including prothrombin time, activated partial thromboplastin time, thrombin time, and platelet count. I discuss hereditary disorders of platelets and/or coagulation proteins that lead to clinical bleeding as well as acquired disorders, including disseminated intravascular coagulation and acquired circulating anticoagulants.

Vasopressin-induced von Willebrand factor secretion from endothelial cells involves V2 receptors and cAMP

Vasopressin and its analogue 1-deamino-8-D-arginine vasopressin (DDAVP) are known to raise plasma von Willebrand factor (vWF) levels. DDAVP is used as a hemostatic agent for the treatment of von Willebrand's disease. However, its cellular mechanisms of action have not been elucidated. DDAVP, a specific agonist for the vasopressin V2 receptor (V2R), exerts its antidiuretic effect via a rise in cAMP in kidney collecting ducts. We tested the hypothesis that DDAVP induces vWF secretion by binding to V2R and activating cAMP-mediated signaling in endothelial cells. vWF secretion from human umbilical vein endothelial cells (HUVECs) can be mediated by cAMP, but DDAVP is ineffective, presumably due to the absence of V2R. We report that DDAVP stimulates vWF secretion in a cAMP-dependent manner in HUVECs after transfection of the V2R. In addition, vasopressin and DDAVP induce vWF secretion in human lung microvascular endothelial cells (HMVEC-L). These cells (but not HUVECs) express endogenous V2R, as shown by RT-PCR. Vasopressin-induced vWF secretion is mimicked by DDAVP and inhibited by the selective V2R antagonist SR121463B. It is mediated by cAMP, since it is inhibited by the protein kinase A inhibitor Rp-8CPT-cAMPS. These results indicate that vasopressin induces cAMP-mediated vWF secretion by a direct effect on endothelial cells. They also demonstrate functional expression of V2R in endothelial cells, and provide a cellular mechanism for the hemostatic effects of DDAVP.

Desmopressin: therapeutic limitations in children and adults with inherited coagulation disorders

Desmopressin (DDAVP), a synthetic analogue of vasopressin has been successfully used in the treatment of type I von Willebrand's disease (VWD), mild factor VIII (FVIII) deficiency and intrinsic platelet function defects (PFDs) for almost three decades. However, there is limited published data documenting its efficacy and the reliability of circulating plasma FVIII:C as a surrogate marker of response to therapy in VWD. We report the haemostatic response to DDAVP in 133 consecutive patients (91 type I VWD, 20 mild FVIII deficiency and 22 PFDs). Minimal therapeutic response to DDAVP (0.3 microg/kg) was defined by normalization 30 min post- infusion of bleeding time for PFDs, factor VIII:C (FVIII:C) for mild haemophilia A, and von Willebrand factor antigen (VWF:Ag), von Willebrand factor functional activity (VWF:Ac) and FVIII:C for VWD. Nine out of 91 (10%) VWD patients failed to achieve minimal therapeutic response to DDAVP; plasma FVIII:C levels were an unreliable surrogate marker of DDAVP response as 6 out of 9 (67%) of these patients had normal post-infusion FVIII:C levels. Five out of the 20 (25%) patients with mild FVIII deficiency and 5 out of 22 (23%) patients with PFDs failed to achieve a minimal therapeutic response to DDAVP. DDAVP is an effective therapy in the majority of patients with type I VWD, PFDs and mild FVIII deficiency. The significant failure rate associated with this therapy supports the recent recommendations that response should be assessed in all patients at the time of diagnosis. FVIII:C is an unreliable guide of response to DDAVP in patients with VWD and therefore VWF:Ag and VWF:Ac should also be assessed. Failure to demonstrate the response of VWF:Ag, VWF:Ac and FVIII:C to DDAVP in patients with VWD is likely to increase the risk of haemorrhagic complications in patients with bleeding episodes or who are undergoing surgery.

Severe hyponatraemia secondary to desmopressin therapy in von Willebrand's disease

A 42-year-old female with von Willebrand's disease was managed with desmopressin and tranexamic acid to aid haemostasis following a vaginal hysterectomy. Severe acute hyponatraemia (134 to 108 mmol/l) developed over two days, culminating in a generalized tonic-clonic seizure and cerebral oedema. Fluid restriction, cessation of desmopressin and hypertonic saline administration led to a full recovery. Desmopressin is known to reduce free water elimination and produce hyponatraemia, but its extent and rate of development in this patient was surprising. Close monitoring of serum sodium and fluid balance is recommended in these patients.

Adverse events during use of intranasal desmopressin acetate for haemophilia A and von Willebrand disease: a case report and review of 40 patients

We report our experience with the incidence of adverse events during the use of Stimate brand intranasal desmopressin acetate (IN DDAVP) for patients with haemophilia A (HA) or von Willebrand disease (vWD) after noting two severe adverse events in one adult patient. All patients with documented vWD (type 1 or 2 A) or haemophilia A (mild, moderate or symptomatic carrier) from the Emory Comprehensive Hemophilia Center who had IN DDAVP challenge testing or were using Stimate for treatment of bleeding were evaluated for adverse events by patient report or nursing observation of clinical signs and symptoms. Forty patients were studied. Sixty-eight per cent (27/40) experienced clinical signs and/or symptoms. The majority of these symptoms were mild, however several patients reported moderate to severe side-effects and one adult patient required medical intervention for symptomatic hyponatraemia. In our experience, two-thirds of patients tested experienced adverse signs and/or symptoms with the use of Stimate; considerably higher than that reported from preliminary results in the literature. Young age did not correlate positively with adverse reactions. Severe adverse events requiring medical intervention were rare, however symptoms such as moderate to severe headache, nausea, vomiting and weakness may necessitate evaluation for hyponatraemia. This is the first report of symptomatic hyponatraemia in an adult patient with recommended dosing of Stimate. Side-effects may be minimized if patients adhere to instructions regarding fluid intake and composition while using IN DDAVP.

Therapeutic monitoring of von Willebrand disease: interest and limits of a platelet function analyser at high shear rates

We have evaluated the position of the Platelet Function Analyzer PFA-100TM in the management of 41 patients with von Willebrand disease (VWD) receiving either desmopressin (23 patients with type 1, five with type 2M, three with type 2A and three with type 2B) or von Willebrand factor (VWF) concentrates (four patients with type 3, two with type 2M 'type B', two with type 2A and one type 1 'platelet low'). In all patients the following were studied before and 30 min after infusion of desmopressin and/or VWF concentrates: VWF ristocetin cofactor activity (VWFRCo), bleeding time (BT) and closure time with the PFA-100 using ADP (CT-ADP) as well as epinephrine (CT-Epi) cartridges. After the infusion of desmopressin, the CT was modified in the same way as the VWFRCo levels, being always normalized in patients with type 1 and not constantly corrected in those with type 2. Thus, our results indicated that the measurement of the CT enabled a quick and accurate evaluation of the response to desmopressin which, in fact, measured the releasable VWF cellular compartment containing the highly multimerized forms of VWF. For patients with type 2 or 3 VWD who were non-responsive to desmopressin, VWF concentrates corrected the VWFRCo defect but not the CT as none of these patients had a normal platelet VWF content and the VWF concentrates did not contain the ultralarge VWF multimers. In conclusion, the very high shear conditions in the PFA-100 make it very sensitive to the contribution of platelet VWF and to the ultralarge VWF multimers, indicating that the evaluation of the CT is a very simple and rapid tool to discriminate between good and non-responders to desmopressin.

Audit of clinical management of von Willebrand disease during 1997 at a single institution and review of treatment patterns between 1980 and 1997

In 1997 the UK Haemophilia Centre Directors Organization published the guidelines for diagnosis and management of von Willebrand disease (vWD). The guidelines stated that desmopressin (DDAVP) should be used in type 1 and type 2N vWD, that it might be useful in other types 2 vWD and that it is ineffective in type 3 vWD. If patients are unresponsive to DDAVP or if it is contraindicated, the treatment of choice is clotting factor concentrates (CFC). In the light of these guidelines, we audited our practice for 1997. Furthermore, we undertook a retrospective review of the changing patterns of treatment of vWD between 1980 and 1997. During 1997, 10 patients with vWD received DDAVP and another 30 patients were treated with CFC (a total of 1.2 million IU): Haemate P (Centeon, Germany) and/or 8Y (BPL, Elstree, UK). Few patients had clear contraindications to DDAVP, but several patients with type 1 and 2 vWD received CFC on the basis of age or reduced levels of von Willebrand factor - where DDAVP was considered suboptimal for adequate haemostasis. However, this assumption was made without a preliminary test dose to assess the response to DDAVP. The analysis of treatment of vWD for the past 17 years showed that cryoprecipitate was discontinued from use in the early 1990s and that both DDAVP and CFC usage has been on the increase. In conclusion, the audit illustrated a general good adherence to guidelines but it highlighted the need for a DDAVP test before using CFC.

Platelet dense granules: structure, function and implications for haemostasis

The advances that have been made over the last decade in microscopic, biochemical, molecular, and genetic techniques have led to substantial improvement in our understanding of platelet dense granule structure and function, and the implications of dense granule deficiencies for haemostasis. However, much has still to be learned. For example, what is the specific mechanism of docking and fusion that occurs during dense granule exocytosis? What are the roles of dense granule membrane proteins during exocytosis or after expression on the surface of activated platelets? Finally, how do the genetic defects identified in HPS and CHS result in the clinical phenotype of these diseases, and what does this tell us about the origin and function of the affected subcellular organelles?

Menstrual disorders. Dysfunctional uterine bleeding

Dysfunctional uterine bleeding is defined as abnormal endometrial bleeding without structural pathology. Although, abnormal uterine bleeding may occur in women of all ages, it is a particularly common issue for adolescents. This article reviews the normal menstrual cycle and the abnormal menstrual cycles. Familiarity with the normal menstrual cycle is necessary to identify the possible causes of abnormal bleeding and aids in the diagnosis and treatment of patients with abnormal uterine bleeding.

Endothelial dysfunction, impaired endogenous fibrinolysis, and cigarette smoking: a mechanism for arterial thrombosis and myocardial infarction

BACKGROUND

Effective endogenous fibrinolysis requires rapid release of tissue plasminogen activator (tPA) from the vascular endothelium. Smoking is a known risk factor for arterial thrombosis and myocardial infarction, and it causes endothelial dysfunction. We therefore examined the effects of cigarette smoking on substance P-induced tPA release in vivo in humans.

METHODS AND RESULTS

Blood flow and plasma fibrinolytic factors were measured in both forearms of 12 smokers and 12 age- and sex-matched nonsmokers who received unilateral brachial artery infusions of substance P (2 to 8 pmol/min). In both smokers and nonsmokers, substance P caused dose-dependent increases in blood flow and local release of plasma tPA antigen and activity (P<0.001 for all) but had no effect on the local release of plasminogen activator inhibitor type 1. Compared with nonsmokers, increases in forearm blood flow (P=0.03) and release of tPA antigen (P=0.04) and activity (P<0.001) caused by substance P were reduced in smokers. The area under the curve for release of tPA antigen and activity decreased by 51% and 53%, respectively.

CONCLUSIONS

Cigarette smoking causes marked inhibition of substance P-induced tPA release in vivo in humans. This provides an important mechanism whereby endothelial dysfunction may increase the risk of atherothrombosis through a reduction in the acute fibrinolytic capacity.

Congenital disorders of platelet function: disorders of signal transduction and secretion

Congenital defects in platelet function are associated with bleeding manifestations of variable intensity and arise by diverse mechanisms. Defects in platelet-vessel wall interaction (disorders of adhesion) may arise because of qualitative or quantitative abnormalities in plasma von Willebrand factor (von Willebrand disease) or in platelet glycoprotein Ib, the binding site on platelets for von Willebrand factor (Bernard-Soulier syndrome). Disorders characterized by abnormal platelet-platelet interaction (disorders of aggregation) arise because of absence of plasma fibrinogen (congenital afibrinogenemia) or because of qualitative or quantitative abnormalities in platelet glycoprotein IIb-IIIa complex (Glanzmann's thrombasthenia). Patients with abnormalities in platelet secretion and signal transduction are a heterogeneous group characterized by impaired aggregation responses and secretion of granule contents. A small proportion of these patients have deficiency of granule stores (storage pool deficiency [SPD]) or impaired production of thromboxane A2; in most, the mechanisms underlying the platelet dysfunction are unknown. Evidence is accumulating that at least some patients have abnormalities in early signal transduction events. Abnormalities in phospholipase C activation, G-protein activation, and other events (eg, protein phosphorylation) have been documented. Platelets play a major role in blood coagulation, and in Scott syndrome, there is an abnormality in platelet contribution to the mechanisms leading to thrombin generation. In most patients with inherited platelet dysfunction, the underlying mechanisms remain to be delineated. Future studies of these patients should yield valuable new information on normal platelet mechanisms.

Females with von Willebrand disease: 72 years as the silent majority

The monthly challenge of menstruation as well as the haemostatic challenge of childbirth postpartum renders more females than males symptomatic with von Willebrand disease. Among vWD patients, the obstetrical and gynaecological morbidity is certainly more pronounced in Type 2,3 patients compared to Type 1 patients, but even in the latter group there is a high proportion of menorrhagia with associated anaemia, loss of time from work/school and the use of hysterectomy for ultimate control of bleeding. Despite the well known adage of the "gestational palliation" of vWD, there is a high proportion of postpartum haemorrhage in Type 1 patients also especially after the first 24 h after delivery. This may occur despite normalization of the factor VIIIc level in the third trimester, particularly in Type 2,3 patients. With the increasing availability of intranasal/subcutaneous DDAVP that could be readily administered at home for menorrhagia, there recently has been ongoing efforts internationally to determine the prevalence of vWD in females presenting with menorrhagia with a prevalence of 17% combined from two studies of 180 patients total. Issues remain regarding the optimal dose/schedule of intranasal/subcutaneous DDAVP for menorrhagia and the relative efficacy of antifibrinolytic agents. The proper role of oral contraceptives and danazol also deserves further study in vWD patients with menorrhagia. In sum, a comprehensive care approach in females with vWD is warranted analogous to the successful model of care of male haemophiliacs with the intent to (a) reduce unnecessary surgical interventions for menorrhagia, (b) improve the quality of life during menses and (c) optimize peri-partum management.

Treatment of von Willebrand Disease

The general goal of therapy in von Willebrand disease is to correct the two defects that are related to the bleeding tendency of these patients, i.e., the abnormal primary hemostasis expressed by a prolonged bleeding time (BT) and the abnormal intrinsic coagulation due to low factor VIII (FVIII) levels. There are two main treatments in von Willebrand disease, i.e., desmopressin and transfusional therapy with blood products. Desmopressin is most effective in patients with type 1, who account for about 80 per cent of all patients. The remaining patients with type 2 and type 3 von Willebrand disease do not respond consistently to desmopressin and need the infusion of blood products containing FVIII and von Willebrand factor. Virally-inactivated concentrates that are currently on the market are preferable to fresh-frozen plasma and cryoprecipate, that still carry a small risk of transmitting blood-borne infections. In rare instance, particularly for hemorrhoages in mucosal tracts such as gastrointestinal bleeding, platelet concentrates are useful adjuncts to plasma concentrates when patients do not respond to the latters. The role of purified von Willebrand factor and of recombinant products is still unclear.