von Willebrand Factor vWF Deficiency

vWF Deficiency: Pathogenesis and clinical findings
Authors: Tristan Jones Reviewers: Sean Spence, Yan Yu, Paige Shelemey, Tony Gu, Man-Chiu Poon* Lynn Savoie* * MD at time of publication
Presence of antibodies to vWF (often in setting of autoimmune disease, e.g., SLE)
Antibodies bind and inactivate existing vWF
Clonal lympho- proliferative disease
Autosomal Dominant Inheritance
Recessive Inheritance
Type III Complete quantitative vWF deficiency
Type I Partial quantitative vWF deficiency
Type II Impaired vWF function (qualitative deficiency)
Reduced vWF quantity and/or function
Less vWF available to bind to damaged vessel collagen to anchor platelets
Impaired platelet plug formation
Reduced vWF
antigen assay
(Diagnostic test for quantitative vWF deficiency)
Reduced plasma Factor VIII (normally stabilized/carried in plasma by vWF)
Impaired intrinsic pathway
Prolonged Partial Thromboplastin Time (PTT)
• Most common inherited bleeding disorder
• Asymptomatic low vWF in 1/100
• Symptomatic low vWF in 1/10,000
• Abs = Antibodies
• vWF = von Willebrand Factor
• vWF:AG = vWF Antigen
Prolonged bleeding/closure time
Bleeding time measures the length of time required to form a platelet plug
Epistaxis (Nosebleeds)
Bleeding from mucosal surfaces Skin bleeding
Easy bruising
Spontaneous hematomas
Sign/Symptom/Lab Finding
Re-published August 4, 2019 on www.thecalgaryguide.com