Platelets from patients with which two disorders will not aggregate with ristocetin?

Question

Quizplus · Accepted Answer

Platelets from patients with von Willebrand's disease and Bernard-Soulier syndrome will not aggregate with ristocetin. This is because ristocetin requires the presence of von Willebrand factor (vWF) to mediate platelet aggregation, and patients with von Willebrand's disease have a deficiency or defect in vWF. Bernard-Soulier syndrome is characterized by a deficiency of the glycoprotein Ib-IX-V complex, which is the receptor for vWF on the platelet surface, thus also leading to impaired platelet aggregation in the presence of ristocetin.

Platelets from Patients with Which Two Disorders Will Not Aggregate