In von Willebrands disease there is:: (A) Isolated prolonged PTT with normal PT, (B) Normal PTT with normal PT, (C) Prolongation of both PT and PTT, (D) Prolongation of thrombin time
Answer is A. Von Willebrand disease (VWD) - - Autosomal dominant disorder - The main source of plasma von-Willebrand factor is endothelial cells. - vWF circulates in the plasma in association with factor VIII. - Patients with VWD have defects in platelet function despite a normal platelet count - Deficiency of von willebrand factor (VWF -promote platelet adherence and activation) causes | platelet adhesion ( |BT) and | Intrinsic pathway activity ( | aPTT) . - von willebrand factor can also be found in : Platelet granules Subendothelium Endothelial cells within cytoplasmic vesicles called Weibel-Palade bodies C/F Spontaneous mucosal bleeding - Petechiae /purpura /epistaxis / melena excessive bleeding from wounds menorrhagia Lab findings - Platelet count - Normal Prothrombin time - Normal Bleeding time - Increased Activated paial thromboplastin time (aPTT)-Increased Rx - Desmopressin for mild form - Cryoprecipitate for severe form