Successful use of recombinant factor VIII devoid of von Willebrand factor during multiple teeth extractions in a patient with type 3 von Willebrand disease

Emicizumab in Type 3 von Willebrand Disease: Report of a Case with an Alloantibody and Literature Review

Type 3 von Willebrand disease (VWD), the most severe form of VWD, is an inherited recessive bleeding disorder caused by the complete deficiency of von Willebrand factor (VWF). The reported prevalence is 1 per million but varies worldwide according to the frequency of consanguineous marriages. The clinical phenotype is characterized not only by mucocutaneous bleedings, but also by hemarthroses and muscle hematoma, as in patients with moderate hemophilia. Long-term prophylaxis with factor (F)VIII/VWF concentrates is recommended in patients with a history of severe and frequent bleeds. A rare complication of replacement therapy is the development of alloantibodies against VWF, with the consequences of an ineffective therapy and risk of anaphylactic reactions upon treatment. Emicizumab is the first bispecific monoclonal antibody that mimics FVIII coagulant activity and is approved for prophylaxis of bleeding in patients with inherited hemophilia A with or without inhibitors and recently also for acquired hemophilia. In this manuscript we report and discuss available data in the literature on the use of emicizumab in type 3 VWD and describe the case of a female patient with type 3 VWD with a history of alloantibodies against VWF and posttransfusion anaphylaxis, recently and successfully put on off-label prophylaxis with emicizumab.

Towards novel treatment options in von Willebrand disease

Deficiency or dysfunction of von Willebrand factor (VWF) is associated with a bleeding disorder known as von Willebrand disease (VWD). The clinical manifestations of VWD are heterogeneous, and are in part dictated by the structural or functional defects of VWF. The tools to control bleeding in VWD are dominated by VWF concentrates, desmopressin and antifibrinolytic therapy. In view of these treatments being considered as effective, it is surprising that quality-of-life studies consistently demonstrate a significant mental and physical burden in VWD patients, particularly in women. Apparently, the current weaponry to support the management of VWD is insufficient to fully address the needs of the patients. It is important therefore to continue to search for innovative treatment options which could better serve the VWD patients. In this short review, two of such options are discussed in more detail: emicizumab to correct for the deficiency of factor VIII (FVIII), and the pegylated aptamer BT200 to increase endogenous levels of the VWF/FVIII complex.

Dental invasive procedures in von Willebrand disease outpatients treated with high purity FVIII/VWF complex concentrate (Fanhdi®): experience of a single center

PURPOSE

To retrospectively assess the effectiveness and safety of customized hemostatic protocols using a plasma-derived, von Willebrand Factor (VWF)-containing Factor VIII concentrate (pdVWF/FVIII) in von Willebrand disease (VWD) patients undergoing dental invasive procedures.

METHODS

Protocol for each patient was drawn up by the Blood Unit based on the VWD type, disease severity, and type of treatment. pdFVIII/VWF infusions and doses were registered at 30-60 min before intervention (t0) and at 12-24-36-48-72 h after intervention (t12-t72) and up to day 7. Any peri- or postoperative bleeding, complication or adverse event was registered.

RESULTS

Forty-five dental procedures were performed on 20 VWD patients (six type-1, two type-2a, six type-2b, six type-3). Most pdFVIII/VWF infusions at t0 were 60 IU/kg (n = 7) and 50 IU/kg (n = 9). Subsequent infusions were mostly 30-50 IU/kg. No bleeding complications or adverse events were reported.

CONCLUSION

This study supports the safety and efficacy of pdFVIII/VWF to prevent peri- and postoperative bleeding after invasive oral procedures.

Anti-hemorrhagic agents in oral and dental practice: an update

Many oral surgeons in their daily practice have the problem of controlling postoperative bleeding. In surgical, oral and maxillofacial practice, standard anti-hemorrhagic protocols, especially in high risk patients, are obviously required and need to be continuously updated. The purpose of this review is to give a rational insight into the management of bleeding in oral and dental practice through modern drugs and medical devices such as lysine analogues and serine protease inhibitors, desmopressin, fibrin sealants, cyanoacrylates, gelatins, collagen and foams, protein concentrates, recombinant factors, complementary and alternative medicine and other compounds.

Evidence-based patient safety advisory: blood dyscrasias

Rarely, patients with blood disorders may seek to undergo plastic surgery. Although plastic surgeons are not expected to diagnose or manage blood disorders, they should be able to recognize which patients are suitable for surgery and which should be referred to a hematologist before a procedure. This practice advisory provides an overview of the perioperative steps that should be completed to ensure appropriate care for patients with blood disorders.

Factor VIII-Mediated Global Hemostasis in the Absence of von Willebrand Factor

Although the efficacy of recombinant factor VIII (rFVIII) in the treatment of type 3 von Willebrand disease (VWD) has been reported, the mechanisms by which FVIII concentrates devoid of von Willebrand factor (VWF) induce improvements in hemostasis are poorly understood. To address the role of FVIII or intrinsic coagulation in the absence of VWF, we performed a hemostatic analysis. Blood samples were obtained before and after the administration of rFVIII to 2 patients with type 3 VWD. A rotating thromboelastometry assay was performed to examine global interactions in hemostasis. Studies of thrombin-and shear-induced platelet aggregation were also conducted to elucidate the effect on platelet activation. Furthermore, we assessed the rise in the thrombin-induced intracellular concentration of free calcium [Ca2+]i. Addition of rFVIII to preinfusion blood in vitro corrected thromboelastometric parameters and thrombin-induced aggregation. In ex vivo studies, thromboelastometry analysis showed that rFVIII shortened the onset and progression of the coagulation process. Furthermore, rFVIII corrected low shear-induced and thrombin-induced platelet aggregation in platelet-rich plasma. In addition, rFVIII improved thrombin-induced [Ca2+]i flux in washed platelets. Our observations suggested that FVIII is incorporated into platelets to activate them, as well as to act directly in intrinsic coagulation in the absence of VWF. FVIII may play a critical role even in the absence of VWF.