Von Willebrand disease (VWD)

Question 1

define VWD

Answer 1

VWD is an inherited bleeding disorder characterised by a reduced quality or function of von Willebrand factor (VWF).

Question 2

what causes VWD

Answer 2

autosomal dominant condition

caused by a mutation of the
VWF gene on chromosome 12.

Question 3

what is the most common inherited bleeding disorder

Answer 3

VWD

Question 4

is VWD more common in men or women

Answer 4

It occurs in equal proportion in men and women

however, women are more likely
to experience symptoms due to increased bleeding from menstruation, pregnancy,
and childbirth.

Question 5

2 main functions of VWD

Answer 5

• Assists in platelet plug formation by
  attracting circulating platelets to the injury
  site.
• Binds to factor VIII, preventing its
  clearance from the plasma.

Question 6

what does an abnormality of VWD lead to

Answer 6

more spontaneous bleeding/bruising.

Question 7

what are all the classification levels of VWD

Answer 7

type 1
type 2
type 3

Question 8

what are the subtypes of type 2 VWD

Answer 8

2A
2B
2M
2N

Question 9

what is type 1 VWD

Answer 9

Partial quantitative deficiency in VWF

Question 10

what is type 2 VWD

Answer 10

Reduced qualitative function of VWF

Question 11

what is type 3 VWD

Answer 11

An almost complete deficiency of VWF

Question 12

what is type 2a VWD

Answer 12

The VWF multimers aren’t the right
size

Question 13

what is type 2b VWD

Answer 13

The VWF multimers aren’t the right
size and the VWF becomes too active

Question 14

what is type 2m VWD

Answer 14

Low/absent binding of VWF to
platelets

Question 15

what is type 2n VWD

Answer 15

VWF has a reduced affinity for factor
VIII

Question 16

which type of patients present more severely with VWD

Answer 16

Patients with type 2 and 3 VWD usually present earlier and more severely than with type 1

Question 17

signs and symptoms of VWD

Answer 17

*Excess/prolonged bleeding
* Easy bruising
* Menorrhagia
* Epistaxis (nose bleeds)
* GI bleeding

Question 18

3 investigations for VWD

Answer 18

1. clotting tests
2. platelet count
3. VWD assay

Question 19

which investigation is diagnostic for VWD

Answer 19

VWD assay

Question 20

what do clotting tests for VWD show

Answer 20

Normal PT and PTT,
prolonged APTT and bleeding time.

Question 21

what does platelet count for VWD show

Answer 21

normal

Question 22

what other investigations are useful. in diagnosing VWD

Answer 22

VWF antigen, VWF activity, and FVIII clotting activity may also be useful.

Question 23

what is VWD treatment aimed at

Answer 23

replacing/increasing
VWF

Question 24

first line treatment for VWD

Answer 24

Desmopressin
(works by temporarily increasing factor VIII and VWF levels by releasing endothelial stores).

Question 25

treatment for acute presentation of VWD

Answer 25

Desmopressin should be given if not already taken. Tranexamic acid for minor bleeding or before surgery. VWF-FVIII concentrates should be used if the above is unsuccessful.