MEDizzy - A 58-year-old man has had episodes of prolonged epistaxis in

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Hemodynamic Disorders

A 58-year-old man has had episodes of prolonged epistaxis in the past 6 months. On examination, he has occult blood detected in his stool. Coagulation studies show that his prothrombin time is elevated, but his partial thromboplastin time (PTT), platelet count, and platelet function are all normal. When his plasma is mixed with an equal amount of normal plasma, the prothrombin time corrects to normal. Which of the following underlying diseases is most likely to be associated with these findings?

ExplanationHis elevated prothrombin time that corrects with normal plasma points to coagulation factor deficiency, and factors II, VII, IX, and X are synthesized in the liver and affect this “extrinsic” in vitro coagulation pathway. They are vitamin K dependent and therefore may also be affected by warfarin therapy or by parenchymal liver disease. Antiphospholipid syndrome has an inhibitory effect upon in vitro coagulation tests and does not correct with addition of normal plasma. The factor V Leiden mutation leads to difficulty inactivating factor V by the action of protein C, thus causing thrombosis, not bleeding. Hemophilia A results from loss of factor VIII function and affects just the partial thromboplastin time (PTT).