What is a characteristic of von Willebrand's disease (VWD), a congenital bleeding disorder?

Von Willebrand Disease Characteristics

Von Willebrand disease (VWD) is the most common congenital bleeding disorder, affecting males and females equally, and is not characterized by hemarthrosis as a common manifestation nor does it result in prolonged prothrombin time. 1

Key Characteristics of VWD

• Prevalence and Inheritance:

  • Affects up to 1% of the general population 1
  • Autosomal inheritance pattern (not X-linked) 1
  • Affects males and females in approximately equal proportions 1, 2

• Pathophysiology:

  • Results from deficiency or dysfunction of von Willebrand factor (VWF) 1
  • VWF is a multimeric plasma glycoprotein that:
    • Mediates platelet adhesion and aggregation at vascular injury sites
    • Carries and stabilizes factor VIII in circulation 1

• Clinical Presentation:

  • Common bleeding manifestations include:
    • Mucosal bleeding (epistaxis, oral bleeding) 3
    • Easy bruising 3, 4
    • Gastrointestinal bleeding 1
    • Heavy menstrual bleeding in women 1
    • Postoperative bleeding 4
  • Hemarthrosis (joint bleeding) is NOT a common manifestation in VWD, unlike in hemophilia 3, 4

Laboratory Findings

• Coagulation Tests:

  • Prolonged bleeding time in 83% of patients 4
  • Normal prothrombin time (PT) - VWD does NOT result in prolonged PT 1
  • Potentially prolonged activated partial thromboplastin time (APTT), especially in cases with lower factor VIII levels 4

• Specific VWD Tests:

  • Decreased VWF:RCo (ristocetin cofactor activity) 4, 5
  • Decreased VWF:Ag (von Willebrand factor antigen) 6
  • Potentially decreased factor VIII activity (FVIII:C) 4

VWD Classification

• Type 1: Partial quantitative deficiency (most common, ~75% of cases) 1
• Type 2: Qualitative deficiency with four subtypes (2A, 2B, 2M, 2N) 1
• Type 3: Virtually complete quantitative deficiency (rare, ~1 in 1,000) 1

Treatment Approaches

• Desmopressin (DDAVP):

  • First-line treatment for Type 1 VWD 7, 3
  • Effective in approximately 81% of patients 4
  • Indicated for patients with factor VIII levels >5% 7

• VWF-containing concentrates:

  • Used for Type 3 and severe forms of Type 1 and 2 VWD 3
  • Indicated when DDAVP is ineffective 3

Important Distinctions

It's important to note that VWD differs from hemophilia in several key aspects:

• VWD affects both genders equally (not male-predominant) 1, 2
• Mucosal bleeding is more characteristic than joint bleeding 3, 4
• Laboratory findings show normal PT but may show prolonged bleeding time 4

The absence of hemarthrosis as a common manifestation and normal prothrombin time are important distinguishing features of VWD compared to other bleeding disorders like hemophilia.