How I treat low von Willebrand factor levels

Abstract

Partial quantitative deficiency of plasma von Willebrand factor (VWF) is responsible for the majority of cases of von Willebrand disease (VWD), the most common inherited human bleeding disorder. International consensus guidelines recommend that patients with reduced plasma VWF antigen (VWF:Ag) levels and bleeding phenotypes be considered in 2 distinct subsets. First, patients with marked reductions in plasma VWF levels (<30 IU/dL) usually have significant bleeding phenotypes and should be classified with “type 1 VWD.” In contrast, patients with intermediate reduced plasma VWF levels (in the range of 30-50 IU/dL) should be considered in a separate category labeled “low VWF levels.” These patients with low VWF commonly display variable bleeding phenotypes and often do not have VWF gene sequence variations. Because the pathophysiology underlying low VWF levels remains largely undefined, diagnosis and management of these patients continue to pose significant difficulties. In this article, we present a number of clinical case studies to highlight these common clinical challenges. In addition, we detail our approach to establishing a diagnosis in low VWF patients and discuss strategies for the management of these patients in the context of elective surgery and pregnancy.

Perioperative management for patients with von Willebrand disease: Defining the optimal approach

“…Furthermore, antifibrinolytics can be used in patients undergoing surgery to minimise the risk of bleeding and the need for blood transfusions as well as the incidence of thromboembolic events 44 . In patients with VWD, the co‐administration of tranexamic acid (15‐25 mg/kg body weight three times a day) in some settings, such as dental procedures, has been shown to be beneficial at reducing the occurrence of bleeds and need for additional coagulation factor replacement 45 …”

“…The surgical management of patients with low VWF levels continues to pose a significant clinical challenge as patients present with variable bleeding phenotypes; treatment should, therefore, also consider personal and family bleeding histories in addition to VWF levels in order to optimise therapy 45 …”

Clinical significance of slightly reduced von Willebrand factor activity (30–50 IU/dL)

“…Increases in VWF levels to normal values in patients with low VWF levels enrolled in the Zimmerman Program were reported in 36% of the population, but for most of these patients, bleeding risk was not reduced. 31,[34][35][36] In the low VWF Ireland Cohort study, Lavin et al 27 examined 126 patients, mostly women (n = 112; 89%), with threshold VWF levels. Diagnosis of low VWF levels was based on patient history, which included bleeding history and VWF level of 30 to 50 IU/dl assayed twice (in a 3 -month interval).…”

“…In patients with VWF levels of 30 to 50 IU/dl and bleeding history, the predictability of future bleeding is markedly higher, whereas in asymptomatic patients with VWF levels of 30 to 50 IU/dl, the risk of bleeding is considered rather low. 12,31,32 Clinical and laboratory characteristics of low von Willebrand factor Test results from various centers using large cohorts of patients suggest that in patients with VWF levels of 30 to 50 IU/dl, bleeding symptoms and VWF levels are most often The mechanism behind this is not fully understood. This is most likely due to the antigenic determinants of the ABO system (H -antigen) expressed on the N -linked VWF polysaccharide chains.…”

¿Qué avances recientes hay en el entendimiento, diagnóstico y tratamiento de la enfermedad de Von Willebrand?: una revisión de la literatura

“…Las opciones terapéuticas incluyen el uso de desmopresina, que libera FVW endógeno de las células endoteliales y el FVW exógeno de los concentrados derivados de plasma de FVW/ FVIII. Esto logra incrementar los niveles de FVW, por lo que previenen eventos hemorrágicos severos (59).…”