Abnormal PFA results and giant platelets best describe which syndrome?

Abnormal PFA results and giant platelets best describe which syndrome?

• A. Bernard-Soulier syndrome
• B. von Willebrand disease
• C. Glanzmann thrombasthenia
• D. May-Hegglin anomaly

Answer: (A)

Giant platelets with abnormal PFA results point to Bernard-Soulier syndrome, an inherited defect of platelet adhesion. In this condition, the GPIb-IX-V receptor complex on the platelet surface is deficient or dysfunctional, so platelets can’t properly bind von Willebrand factor. That impaired adhesion leads to a bleeding tendency and, importantly, platelets are abnormally large (macrothrombocytopenia). When a platelet function test like the PFA is used, closure times are markedly prolonged because the initial steps of forming a platelet plug (adhesion and activation) are compromised. This combination of giant platelets and a defective adhesion response is characteristic of Bernard-Soulier syndrome. von Willebrand disease mainly involves deficient or dysfunctional von Willebrand factor and typically does not feature giant platelets. Glanzmann thrombasthenia involves a defect in platelet aggregation (GPIIb/IIIa) with normal-sized platelets, so giant platelets are not a hallmark. May-Hegglin anomaly can show giant platelets as well, but the classic PFA pattern and the combination with adhesion defects are best explained by Bernard-Soulier syndrome.

Giant platelets with abnormal PFA results point to Bernard-Soulier syndrome, an inherited defect of platelet adhesion. In this condition, the GPIb-IX-V receptor complex on the platelet surface is deficient or dysfunctional, so platelets can’t properly bind von Willebrand factor. That impaired adhesion leads to a bleeding tendency and, importantly, platelets are abnormally large (macrothrombocytopenia). When a platelet function test like the PFA is used, closure times are markedly prolonged because the initial steps of forming a platelet plug (adhesion and activation) are compromised. This combination of giant platelets and a defective adhesion response is characteristic of Bernard-Soulier syndrome.

von Willebrand disease mainly involves deficient or dysfunctional von Willebrand factor and typically does not feature giant platelets. Glanzmann thrombasthenia involves a defect in platelet aggregation (GPIIb/IIIa) with normal-sized platelets, so giant platelets are not a hallmark. May-Hegglin anomaly can show giant platelets as well, but the classic PFA pattern and the combination with adhesion defects are best explained by Bernard-Soulier syndrome.