Platelet

Question 1

Investigating platelet secretion defects

Answer 1

Lumiaggregometry: Bioluminescent method using luciferin-luciferase reagent which releases light with ATP release
i.e. plt granule release ∝ light emission. Agonists are the same as LTA.

Question 2

Glanzmanns

Answer 2

GpIIb/IIIa receptor defect
Normal platelet appearance
Agglutination only seen with ristocetin (occurs independently of fibrinogen)
Gives a “global defect”
Ddx afribrinogenaemia