Bleeding Disorders

Question 1

Type 1 VWD

Answer 1

partial quantitative deficiency
75% of individuals with VWD
AD inheritance
Tx desmopressin (DDAVP)

Question 2

Type 2a VWD

Answer 2

qualitative variant
decreased platelet adhesion due to deficiency in HMW VWF multimers
20% of individuals with VWD
Tx DDAVP

Question 3

Type 2b VWD

Answer 3

qualitative variant
enhanced spontaneous GP1b binding
thrombocytopenia
do not use DDAVP

Question 4

Type 3 VWD

Answer 4

severe quantitative deficiency/absent VWF
rare
do not use DDAVP

Question 5

hemophilia A

Answer 5

X-linked
normal PT, prolonged PTT, corrects with 50/50 mixing study
Factor VIII deficiency
severe: <1% normal factor level
moderate: 1-5% normal factor level
mild: > 5% normal factor level
Tx: Factor VIII concentrates
30% develop inhibitors that inactivate concentrates
Goal:
- severe bleeding: Factor level 80-100%
-hemarthrosis: Factor level 50%

Question 6

hemophilia B

Answer 6

X-linked
normal PT, prolonged PTT, corrects with 50/50 mixing study
Factor IX deficiency
severe: <1% normal factor level
moderate: 1-5% normal factor level
mild: > 5% normal factor level
Tx: Factor IV concentrates
Goal:
- severe bleeding: Factor level 80-100%
-hemarthrosis: Factor level 50%

Question 7

inherited platelet disorders

Answer 7

Bernard-Soulier syndrome (BSS)

Question 8

aVWS

Answer 8

lymphoproliferative disorders
autoimmune disorders
MPNs

Question 9

Treatment for inhibitors to concentrates

Answer 9

recombinant Factor VIIa (Novoseven)
activated prothrombin (PT) complex (FEIBA)

Question 10

Treatment for inhibitors to concentrates

Answer 10

recombinant Factor VIIa (Novoseven)
activated prothrombin (PT) complex (FEIBA)

Question 11

vwf

Answer 11

binds to collagen at sites of vascular injury
carrier protein for Factor VIII
mediates platelet adhesion and aggregation via vwf-GP1b interaction.

Question 12

VWD diagnosis

Answer 12

- measurements of von Willebrand factor
antigen (VWF:Ag)
- the level of von Willebrand factor–dependent platelet adhesion (i.e. von Willebrand factor–ristocetin
cofactor activity assay VWF:RCo)
- Factor VIII activity (FVIII:C)

Question 13

VWD Type 2 dx

Answer 13

• ratio of von Willebrand factor–ristocetin cofactor activity to von Willebrand factor antigen, ≤0.6
• Further subtyping tests,
  such as assays of von Willebrand factor multimers
  and ristocetin-induced platelet aggregation, are
  then required to determine the phenotypic characteristics that define types 2A, 2B, and 2M von
  Willebrand’s disease

Question 14

VWD Type 2N

Answer 14

-ratio of factor VIII activity to von Willebrand factor
antigen, ≤0.6
DDX Mild hemophilia A