What is the expected effect of liver disease on coagulation tests?

• A. Prolonged TT only.
• B. Prolonged PT and aPTT due to reduced synthesis; may have concomitant thrombocytopenia.
• C. Shortened PT and aPTT.
• D. Normal coagulation tests.

Answer: (B)

When the liver is damaged, its ability to synthesize most coagulation factors drops, and it also produces less thrombopoietin, which can lead to fewer platelets. Because both the extrinsic pathway (measured by PT) and the intrinsic pathway (measured by aPTT) rely on these factors, clotting times for both tests become prolonged. Platelet count can be low, adding to bleeding risk. Thrombin time can also be affected if fibrinogen is reduced, but the characteristic pattern in liver disease is prolonged PT and prolonged aPTT due to reduced synthesis of multiple factors and potential thrombocytopenia. Shortened times or normal tests would not fit this coagulation dysfunction.