Imtensive Recap

Question 1

Normal platelets have a circulating life span of approx.:

Answer 1

9 - 10 days (10 days)

Question 2

Platelet dense granules contain:

Answer 2

(CAPAS ME!)
✅ Calcium
✅ Storage ADP
✅ Serotonin
❌ PF4 (alpha granules)

*Dense granules are found on organelled zone

Question 3

Which of the following measures platelet function?

Answer 3

Bleeding time
• Screening for plt dysfunctions and vWD
• Directly affected by: plt ct., thickness and vascularity of skin, ability of blood vessels
• Not affected by coag. mechanism

Question 4

To evaluate normal platelet numbers in an appropriate area of a blood smear, approx. how many platelets should be observed per OIF?

Answer 4

8 to 20

*Plt estimation = ave. no. of plt x 20 000

Question 5

Thrrombocytosis may be assoc. with:

Answer 5

Post-splenectomy and Polycythemia vera

• Significant bleeding: <60 x 10^9/L

Question 6

What is the characteristic of Bernard-Soulier Syndrome?

Answer 6

Giant platelets (> 20 um)

• Deficiency in GPIb
• ⬆️ BT, ❗️ Ristocetin

Question 7

A patient has been taking aspiring regularly for arthritic pain. Abnormal test:

Answer 7

Template bleeding time
• Modification of routine BT; uses template which contains a standard slit

• Aspirin: Acetyl salicylic acid; causes abn aggregation with A, C, E

Question 8

Platelet GP IIb/IIIa complex is:

Answer 8

Membrane receptor for fibrinogen (Glanzmann - AR)

Question 9

Platelet response assoc. with Glanzmann’s thrombasthenia?

Answer 9

Normal platelet aggregation response to risotcetin;

⬇️ response to collagen, ADP, epinephrine (ACE)

Question 10

Platelet aggregation studies:
Normal - collagen, epinephrine, ADP
Abnormal - ristocetin

Differential dx?

Answer 10

Von Willebrand Dse vs. Bernard Soulier Syndrome

Question 11

What is the platelet response most likely assoc. with classic VWD.

Answer 11

⬇️ Plt aggregation to ristocetin

Question 12

The preffered blood product for a bleeding px with VWD is transfused with:

Answer 12

Cryoprecipitated AHF