Platelet disorders and Aggregometry
Glanzmann Thrombasthenia

Platelet disorders and Aggregometry

Glanzmann Thrombasthenia

 • Defective aggregation to all agonists except ristocetin

 • Normal platelet, PT, PTT (diff from afibrinogenemia, which will have a similar aggregation pattern)

 • Platelet count and platelet morphology — normal

 • Platelet flow cytometry — GP Ilb/llla (CD41/CD61) is absent


 • Defective aggregation to high-dose ristocetin; normal aggregation with other agonists

 • This pattern could also be seen in vWD (either severe Type 1 or Type 3) — differentiate vWD from BS by measuring vWF level or flow for Gplb receptor

 • Thrombcytopenia and giant platelets

 • Platelet flow cytometry— GP lb/lX/V (CD42b) is absent or dysfunctional; may be normal with qualitative defects of GP lb/lX/V

Von Willebrand Disease

 • Decreased aggregation to HD ristocetin, but platelet aggregation is not considered first-line testing

 • Usually normal platelet count and morphology

Dr. Laura Brown @lauraebrown

#Platelet #disorders #hematology #hemepath #differential #diagnosis #Aggregometry
Contributed by

Dr. Gerald Diaz
Board Certified Internal Medicine Hospitalist, GrepMed Editor in Chief 🇵🇭 🇺🇸 - Sign up for an account to like, bookmark and upload images to contribute to our community platform. Follow us on IG: | Twitter:

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