Platelet Disorders

Question 1

Von willebrandts factor

In primary hemostasis

Answer 1

Binds collagen to platelets via GP1BIX

Activated platelets undergo shape change and releases granules (ADP, TXA2, 5HT)

Question 2

Platelets adhere to each other via

In primary hemostasis

Answer 2

GP2b3a activation

After granule release

Question 3

Platelet progenitor cell

Answer 3

Megakaryocyte

Question 4

Thrombocytopenia

Answer 4

Low platelets below 150,000

Risk for bruising and bleeding
Severe below 10,000

Drug-induced
Bactrim, vancomycin, acyclovir
H2RA, Quinidine

Abciximab, heparin

Question 5

Thrombocytosis

Answer 5

Platelets high above 450,000

Defect in the JAK2 pathway

Primary thrombocytosis
Treat with: Hydroxyurea
Anagrelide

Don’t treat reactive thrombocytosis

Question 6

Thrombotic thrombocytopenia Pentad

(Microangiopathic hemolytic anemia)

Due to loss of ADAMTS13 and enlarged vWF

NFRST

Answer 6

Thrombocytopenia 
Schistocytes (sheared RBC)
Fever
Neurological symptoms
Renal failure

Treat with plasma exchange

Question 7

Platelets dysfunction disorder

Gray Gran
Bernard 1B
Glanz 3a

Answer 7

Acquired: liver, renal disease, aspirin

Inherited:
Gray - lack granules
Bernard - GP1BIX deficient
Glanzman - GP2b3a

Question 8

Immune thrombocytopenia

Answer 8

Treat with prednisone
IV IgG

Rituximab to spare long term prednisone

Question 9

Immune thrombocytopenia

Answer 9

Treat with prednisone
IV IgG

Rituximab to spare long term prednisone