Which condition shows normal prothrombin time, usually prolonged partial thromboplastin time, prolonged bleeding time, and normal platelet count?

Which condition shows normal prothrombin time, usually prolonged partial thromboplastin time, prolonged bleeding time, and normal platelet count?

• A. Haemophilia
• B. Thrombocytopenia
• C. Von Willebrand disease
• D. Aspirin

Answer: (A)

The pattern described points to von Willebrand disease. When prothrombin time is normal, it means the extrinsic pathway is intact. If the partial thromboplastin time is usually prolonged, that suggests an issue with the intrinsic pathway or with factor VIII stability, which von Willebrand factor helps maintain. A prolonged bleeding time indicates a problem with primary hemostasis—platelets not forming the initial platelet plug effectively. Yet the platelet count being normal shows that there aren’t fewer platelets, just a functional defect. Von Willebrand factor is essential for platelet adhesion to the subendothelium and it also protects factor VIII; when it’s deficient or defective, you get impaired platelet adhesion and sometimes reduced factor VIII activity, leading to prolonged bleeding time and sometimes a prolonged aPTT, with a normal PT. Haemophilia, by contrast, typically has a normal bleeding time because primary hemostasis is intact, and the main issue is a defect in the coagulation cascade that prolongs aPTT. Aspirin can extend bleeding time by impairing platelet function but doesn’t reliably prolong aPTT. Thrombocytopenia lowers platelet count, which is not seen here.

The pattern described points to von Willebrand disease. When prothrombin time is normal, it means the extrinsic pathway is intact. If the partial thromboplastin time is usually prolonged, that suggests an issue with the intrinsic pathway or with factor VIII stability, which von Willebrand factor helps maintain. A prolonged bleeding time indicates a problem with primary hemostasis—platelets not forming the initial platelet plug effectively. Yet the platelet count being normal shows that there aren’t fewer platelets, just a functional defect. Von Willebrand factor is essential for platelet adhesion to the subendothelium and it also protects factor VIII; when it’s deficient or defective, you get impaired platelet adhesion and sometimes reduced factor VIII activity, leading to prolonged bleeding time and sometimes a prolonged aPTT, with a normal PT.

Haemophilia, by contrast, typically has a normal bleeding time because primary hemostasis is intact, and the main issue is a defect in the coagulation cascade that prolongs aPTT. Aspirin can extend bleeding time by impairing platelet function but doesn’t reliably prolong aPTT. Thrombocytopenia lowers platelet count, which is not seen here.