12. Von Willebrand disease Flashcards
1
Q
when does acquired VWD occur?
A
rare. associated with many underlying disorders (malignancy, hypothyroidism, multiple myeloma)
caused by different mechanisms (anti-vWF Ab’s–> ↑ clearance ↓ synthesis)
2
Q
what is the most common VWD type?
A
type 1 (75%) reduced levels of vWF
3
Q
how is type 2 VWD classified?
A
dysfunctional VWF protein type 2A type 2B type 2M type 2N
4
Q
what occurs in type 3 VWD?
A
absent levels of VWF
5
Q
clinical manifestations of VWD
A
- mucosal bleeding symptoms
- post-operative bleeding
- manifest in later childhood
- menorrhagia (common in women)
- mild disease seen with dental extractions or tonsillectomy
6
Q
how do we measure the vWF activity?
A
ristocetin cofactor assay
7
Q
diagnosis of vWD
A
- ↓ vWF antigen assay (vWF:Ag)
- ↓ vWF activity
- vWF multimer analysis
- ↓ F. VIII, ↑ PTT, ↓ PLT
8
Q
Management vWD
A
- Desmopressin (SE: hyponatremia)
- VWF replacement therapy (cryoprecipitate, factor VII, recombinant vWF)
- Anti-fibrinolytic therapy (aminocaproic acid or tranexamic acid) - adjunctive or prophylaxis therapy
