A 9-year-old boy with acute liver failure is bleeding from his intravenous sites. Laboratory studies show a prolonged Prothrombin Time, a prolonged Partial Thromboplastin Time, and thrombocytopenia. You are trying to differentiate the coagulopathy of severe liver disease from disseminated intravascular coagulation. Which of the following laboratory findings would most strongly support a diagnosis of severe liver disease over disseminated intravascular coagulation?