Synthesis of which of the following clotting factors is not affected in liver disease?
**Core Concept**
The coagulation cascade involves the synthesis of various clotting factors in the liver. Liver disease can significantly impact the production of these factors, leading to coagulopathy. The synthesis of clotting factors is primarily regulated by the liver, which produces most of the clotting factors, except for a few.
**Why the Correct Answer is Right**
Factor VII is synthesized in the liver and is the only clotting factor that is produced in the liver and also synthesized in the endothelial cells. However, its synthesis in the liver is not significantly affected in liver disease. This is because Factor VII is produced in the liver to a lesser extent compared to other clotting factors. In contrast, factors like prothrombin (Factor II), Factor V, Factor VII (produced in the liver), Factor X, and fibrinogen (Factor I) are significantly reduced in liver disease.
**Why Each Wrong Option is Incorrect**
**Option A:** Factor II (Prothrombin) - Liver disease significantly affects the synthesis of Factor II, leading to reduced levels.
**Option B:** Factor V - The liver is the primary site for Factor V synthesis, and liver disease can lead to reduced levels.
**Option C:** Factor VII (produced in the liver) - Although Factor VII is also produced in endothelial cells, its synthesis in the liver is significantly impacted in liver disease.
**Clinical Pearl / High-Yield Fact**
Liver disease can lead to a significant reduction in the production of clotting factors, making patients more prone to bleeding. This is particularly relevant in patients with cirrhosis or liver failure, who may require careful management of coagulopathy.
**Correct Answer: D. Factor VII**