What is indicated by normal PT, prolonged APTT, increased bleeding time, and normal platelet count?

The combination of normal prothrombin time (PT), prolonged activated partial thromboplastin time (APTT), increased bleeding time, and a normal platelet count aligns well with von Willebrand’s disease.

In von Willebrand’s disease, the defect primarily affects the function of von Willebrand factor, which is essential for platelet adhesion and helps stabilize Factor VIII in circulation. This dysfunction leads to prolonged APTT due to the involvement of Factor VIII but does not affect the PT, as the extrinsic pathway remains intact. The increased bleeding time is due to impaired platelet function resulting from the deficiency or dysfunction of von Willebrand factor, despite the platelet count being normal.

Other conditions would demonstrate different patterns. For instance, Factor VIII and IX deficiencies would typically present with a prolonged APTT but would not increase bleeding time to the same degree without affecting the platelet count. DIC often shows significant changes across multiple coagulation parameters, including both PT and APTT, indicating a more systemic coagulopathy. Therefore, the specific combination of normal PT, prolonged APTT, and increased bleeding time with a normal platelet count is characteristic of von Willebrand’s disease.