von Willebrand Disease: Local Diagnosis and Management of a Globally Distributed Bleeding Disorder

Abstract

von Willebrand disease (VWD) is the most common inherited bleeding disorder and arises from deficiencies and/or defects in the plasma protein von Willebrand factor (VWF). The current report overviews the diagnosis and management of VWD as reflected by differential processes applied within centers around the world. The prevalence of VWD, as well as the frequency of different VWD types, is also reported. VWD prevalence data varies according to methodology used, with epidemiological/population screening estimates approximating 1% of the population (or 10,000 cases per million population), several orders of magnitude higher than estimates from bleeding disorders registry data or regional/center analysis (which instead range from <1 to ~450 cases per million population). Frequency of different VWD types also varies according to source and analysis, with type 1 VWD identified as the clear dominant type in most developed countries (ranging from 40% to 90% of all VWD cases), whereas type 3 VWD predominates in developing countries such as India and Iran. The frequency of qualitative (i.e., type 2) VWD also varies considerably among different reports, ranging from 3% to >50% of all VWD cases, as does the frequency of specific qualitative VWD types (i.e., 2A, 2B, 2M, and 2N). Although type 2A VWD is considered the most common form of type 2 VWD, in some reports workers consider type 2M VWD to be as, or more, common. Although not considered to be a "true" VWD, given its platelet origin, platelet-type VWD is only rarely identified. Finally, management of VWD also differs according to geographic region. Most developed countries use standard therapy, employing desmopressin (DDAVP) wherever possible, factor concentrate in other situations, and antifibrinolytic therapy as required. In contrast, the relative high cost and unavailability of factor concentrates in developing countries, and sometimes the unavailability of DDAVP, requires different management strategies to be applied.

An international survey to inform priorities for new guidelines on von Willebrand disease

“…In the most severe cases, musculoskeletal bleeding may be seen. The prevalence based on patients who present to tertiary care centres with clinical symptoms is reported to be 0.01% 8,9 ; symptomatic VWD in primary care clinics is described to be at least 0.1% [8][9][10] ; and VWD can affect up to 1% of the general population based on epidemiological studies. 6 These bleeding symptoms have implications for daily living and are associated with a reduced quality of life in VWD patients.…”

Establishment and characterization of a new and stable collagen‐binding assay for the assessment of von Willebrand factor activity

“…Von Willebrand disease (VWD) is considered the most common inherited bleeding disorder, with conservative estimates of incidence in the general population of around 100 per million persons and up to one in 1000 in the primary care setting . There are currently six types of defined VWD, as caused by a variety of mutations .…”

Different bleeding risk in type 2A and 2M von Willebrand disease: a 2‐year prospective study in 107 patients: a rebuttal

“…This is an important finding, and should provide support for the ongoing diagnostic differentiation of type 2A and type 2M VWD. The exact frequencies of these two forms of VWD are unknown, although a recent geographically global analysis indicated much variability in their perceived incidence [2], with type 2A and type 2M VWD, respectively, reported as comprising 5.5–82.6% and 0–56.3% (Fig. 1A) of all cases of type 2 VWD.…”

“… Type 2A vs. 2M von Willebrand disease (VWD). (A) Summary of relative frequency data for type 2A and type 2M VWD, as reported by centers representing a global distribution of testing facilities, and shown as percentage of type 2 VWD cases [2]. A wide variety in relative frequency is reported, although most centers report identifying higher numbers of type 2A VWD cases than of type 2M VWD cases.…”