VWD

Question 1

def VWD

Answer 1

bleeding disorder

type 1 (60-80%) - reduced levels of vWF, mild symptoms, autosomal dominant

type 2 (20-30%) - abnormal vWF, with lack of high molecular weight multimers, usually autosomal dominant, bleeding tendency varies

type 3 (1-5%) - Undetectable vWF levels (autosomal recessive with gene deletions). vWF antigen is lacking and there is reduced factor VIII. Symptoms can be severe.

Question 2

aetiology of VWD

Answer 2

abnormalities in expression or function of vWF

usually autosomal dominant, sometimes recessive

acquired forms

vWF is a plasma glycoprotein involved in clotting

1. adhesive bridge between platelet receptors (GP-Ib) and damaged subendothelium collagen IV of vessels.
2. makes platelets bind to each other
3. Binds to FVIII and prevents degradation in circulation

Question 3

RF VWD

Answer 3

FH and consanguineous relationships

Question 4

epi VWD

Answer 4

VWD is the most common inherited bleeding disorder, affecting 66 to 100 people per million of the general population,

Question 5

sx VWD

Answer 5

mucocutaneous bleeding - mouth, epistaxis, menorrhagia

increased bleeding after minor trauma

easy bruising

increased bleeding after tooth extraction

post op bleeding

FH of bleeding

GI bleeding

Question 6

Ix for VWD

Answer 6

increased bleeding time

increased APTT

reduced FVIIIc (clotting activity)

reduced vWF levels

Ristocetin cofactor assay (reduced platelet aggregation by vWF in the presence of ristocetin).

no change in INR/platelets