Prophylaxis and von Willebrand's disease (vWD)

Similarity in joint function limitation in Type 3 von Willebrand's disease and moderate haemophilia A

Type 3 von Willebrand's disease (VWD) is a rare bleeding diathesis with complete or near complete deficiency of von Willebrand factor (VWF) and low factor VIII (FVIII) levels. In contrast, only FVIII is decreased in haemophilia A (HA). Both disorders are complicated by arthropathy. The purpose of this study was to further clarify the roles of FVIII and VWF: Antigen (VWF:Ag) in joint range of motion (ROM) loss over time. We compared joint ROM loss and other bleeding manifestations in 100 Type 3 VWD subjects (FVIII<5%) and 1814 moderate HA subjects (FVIII 1-5%) within the U.S. Universal Data Collection (UDC) database. High rates of bleeding were reported at baseline. During follow-up, moderate HA patients reported a joint (46% vs. 34%, P < 0.0001) or muscle bleed (27% vs. 16%, P < 0.0001) in a higher proportion of visits than VWD patients. Other bleeds, including mucosal, were reported in a greater proportion of visits among patients with Type 3 VWD than among those with HA (49% vs. 32%, P < 0.0001). Multivariate analysis revealed no difference in joint ROM loss over time in the Type 3 VWD vs. moderate HA populations. A higher FVIII level was protective in both VWD and HA (P < 0.001). Our findings support the hypothesis of primacy of the FVIII level in determining risk of joint haemorrhage, and may help target therapy in Type 3 VWD and moderate HA to prevent joint disability.

Long-term secondary prophylaxis in children, adolescents and young adults with von Willebrand disease. Results of a cohort study

In patients with von Willebrand disease (VWD) replacement therapy with factor VIII/von Willebrand (VWF) concentrates is increasingly applied as prophylactic regimen. Since 2000, 82 consecutively enrolled patients with clinically relevant bleeding episodes (spontaneous, peri- or postoperative) were diagnosed with VWD [type 1: 42/82; type 2: 24/82; type 3: 13/82; acquired: 3/82]. In all patients, decision for initiating prophylaxis was based on a bleeding score > 2 prior to diagnosis, concomitant with recurrent bleeds associated with anaemia in patients with on-demand VWD therapy. We report results on secondary prophylactic VWF replacement therapy applied in 32 patients [children n=13; adolescents n=7; adults n=12] with VWD [type 1: 4; type 2: 15; type 3: 13], 15 of which were females, and nine of these at the reproductive period. Eight patients were treated with Humate P® or Wilate® (n=24). Median [min-max] dose [vWF:RCo] was 40 [20-47] IU/kg, 23 patients were given substitution therapy twice weekly, seven patients three times a week, and two children four times per week. Within a 12-month-period haemoglobin concentrations returned to normal values. Median duration of prophylaxis was three years. Recurrent bleeding episodes stopped in 31 of 32 patients, whereas inhibitors developed in one. Following a 12-month observation period the monthly bleeding frequency and the bleeding score was significantly reduced [3 vs. 0.07; 3 vs. 0: p< 0.001], compared to the pre-prophylaxis/pre-diagnostic values. The use of secondary prophylactic VWF replacement therapy is an effective tolerated treatment modality, highly beneficial for patients with VWD, who present with recurrent bleeding events during on-demand therapy.

Prophylaxis in von Willebrand disease

Von Willebrand disease (VWD), the most common hereditary bleeding disorder, is divided into three types depending on the quantitative (type 1 and 3) or qualitative (type 2) abnormality of von Willebrand factor (VWF). About 70-80% of VWD patients can be treated with the synthetic product desmopressin, while the others necessitate factor VIII/VWF concentrates. In addition to the treatment of bleeding episodes, therapeutic regimens include short- or long-term prophylaxis. While the literature data on short-term prophylaxis in VWD are consistent and clearly show the safety and efficacy of such a therapeutic approach, little evidence is available regarding long-term prophylaxis, and although the preliminary results are encouraging, they need to be validated by large prospective studies.