Platelets

Question 1

Which glycoprotein on platelets binds to fibrinogen ?

Answer 1

Glycoprotein IIb-IIIa or integrin alphaII-beta3 or Fibrinogen receptor

Question 2

What is Glanzmann thrombasthenia ?

Answer 2

Deficiency in glycoprotein IIb-IIIa;CD41/61
Mutations in genes encoding for
- calcium binding domains within alphaIIb

Question 3

Which breeds are predisposed to Glanzmann thrombasthenia ?

Answer 3

Breeds predisposed:

• Great Pyrenees
• Otterhound
• Thoroughbred (England)
• Quarter Horse (Alabama)
• Peruvian paso (Idaho)
• Oldenbourg (Canada)

Question 4

What are the different types of Glanzmann thrombasthenia ?

Answer 4

Type I:

Question 5

Which glycoprotein on platelets binds to Von willebrand factor ?

Answer 5

Glycoprotein Ib

Question 6

Platelet function analyzer-100 (PFA-100)

Answer 6

• Aperture closure instrument
• Global platelet adhesion and aggregation under high shear mediated by gpIB-VWF interaction
• Cartridge membranes are coated with collagen and either adenosine diphosphate or epinephrine
• Final closure time affected by:
  - platelet function
  - platelet count
  - hematocrit