<prompt> PTT is prolonged in all except:-Hemophilia AVon Willebrand diseaseChristmas diseaseITP  <response>: aPTT is used to monitor the activity of Intrinsic pathway. A. Hemophilia B. Von Willebrand disease C. Christmas disease D. ITP - Idiopathic Thrombocytopenic Purpura most common type of hemophilia is Hemophilia A . Hemophilia A - Factor VIII deficiency aPTT Associated with reduction in the half life of Factor VIII aPTT Factor IX deficiency aPTT Disease associated with platelets, not a clotting factor problem. Parameters affected in ITP a. Increase bleeding time b. Decrease platelet count 