Which condition is NOT associated with abnormal initial platelet adhesion to the subendothelial matrix?

Which condition is NOT associated with abnormal initial platelet adhesion to the subendothelial matrix?

• A. Factor XIII deficiency
• B. Von Willebrand disease and Bernard-Soulier syndrome
• C. Hemophilia A
• D. Glanzmann thrombasthenia

Answer: (A)

Initial platelet adhesion to the subendothelial matrix depends on von Willebrand factor binding to the platelet GPIb-IX-V receptor. When this vWF–GPIb axis is defective, adhesion at the very start of plug formation is impaired, as seen in von Willebrand disease and Bernard-Soulier syndrome. Defects that primarily disrupt aggregation, such as Glanzmann thrombasthenia (lack of GPIIb/IIIa), don’t typically abolish the initial tethering to the damaged vessel wall. Hemophilia A, due to factor VIII deficiency, affects thrombin generation and fibrin formation rather than the initial adhesion step. Factor XIII deficiency, which impairs crosslinking of fibrin, similarly does not alter the ability of platelets to adhere initially. Therefore, Factor XIII deficiency is not associated with abnormal initial platelet adhesion to the subendothelial matrix.

Initial platelet adhesion to the subendothelial matrix depends on von Willebrand factor binding to the platelet GPIb-IX-V receptor. When this vWF–GPIb axis is defective, adhesion at the very start of plug formation is impaired, as seen in von Willebrand disease and Bernard-Soulier syndrome. Defects that primarily disrupt aggregation, such as Glanzmann thrombasthenia (lack of GPIIb/IIIa), don’t typically abolish the initial tethering to the damaged vessel wall. Hemophilia A, due to factor VIII deficiency, affects thrombin generation and fibrin formation rather than the initial adhesion step. Factor XIII deficiency, which impairs crosslinking of fibrin, similarly does not alter the ability of platelets to adhere initially. Therefore, Factor XIII deficiency is not associated with abnormal initial platelet adhesion to the subendothelial matrix.