Question

A 15 year old male was admitted for hernia surgery. The patient reported having had

many headaches recently and also frequent epistaxsis. The physician ordered a battery of

hemostasis screening tests with the following results:

Platelet Count = 250 x 109/L	Protime = 12.9 sec	Fibrinogen = 280 mg/dL
Bleeding Time = 14 min	APTT = 32 sec	D-Dimer= Normal

QUESTION If the bleeding problem was induced by medication, what platelet aggregation pattern would you expect when using ADP as the agonist? Ristocetin?

Answer 1

Answer: The bleeding problem was induced by medication, then ADP that isnthe adenosinw diphosphate is the platelet agonist which mainly causes the aggregation by changing the platelet shape. This also includes the initiation of the thromboxane A2 which is also the the platelet agonist hence this directly effects on the receptors such as P2Y1, P2Y12, and P2X1. So, the Ristocetin is one of the antimicrobial substance which mainly forms the complex and hence causes changes in the vWF, by comformational changes in the vWF. This induces the aggregation of the platelets.