The platelet aggregation pattern drawn is characteristic of which aggregating agent?

The platelet aggregation pattern drawn is characteristic of which aggregating agent?

• A. ADP
• B. Collagen
• C. Ristocetin
• D. Thrombin

Answer: (B)

The pattern described is typical of collagen because collagen activates platelets through receptors such as GPVI and α2β1, triggering a signaling cascade that leads to sustained platelet activation and recruitment. On an aggregation tracing, this shows up as a slower onset with a large, steady plateau as aggregates continue to form and stabilize. This contrasts with the rapid, sharp curves usually seen with thrombin or ADP, where the response rises quickly to a peak, and with ristocetin, which relies on von Willebrand factor and often yields little or differently shaped aggregation in normal platelets. So the drawn pattern best fits collagen-induced aggregation due to its characteristic gradual, robust plateau reflecting collagen’s mechanism of activating platelets.

The pattern described is typical of collagen because collagen activates platelets through receptors such as GPVI and α2β1, triggering a signaling cascade that leads to sustained platelet activation and recruitment. On an aggregation tracing, this shows up as a slower onset with a large, steady plateau as aggregates continue to form and stabilize. This contrasts with the rapid, sharp curves usually seen with thrombin or ADP, where the response rises quickly to a peak, and with ristocetin, which relies on von Willebrand factor and often yields little or differently shaped aggregation in normal platelets. So the drawn pattern best fits collagen-induced aggregation due to its characteristic gradual, robust plateau reflecting collagen’s mechanism of activating platelets.