Causes of Elevated Aspartate Aminotransferase (AST)

Aspartate aminotransferase (AST), clinically also known as glutamic-oxaloacetic transaminase (GOT), is commonly abbreviated as AST in liver function tests. Its concentration is highest in myocardial and hepatocytes. AST resides in both the mitochondria and cytoplasm of hepatocytes and primarily reflects hepatic functional status. Causes of elevated aspartate aminotransferase levels include:

1. Hepatic diseases, such as alcoholic liver disease, nonalcoholic fatty liver disease (NAFLD), cirrhosis, hepatocellular carcinoma, hepatitis B, and hepatitis A. Additionally, hepatic tumors—whether primary or metastatic—can also lead to elevated AST levels.

2. Vascular disorders, such as Budd-Chiari syndrome—a condition caused by obstruction of the hepatic veins or the inferior vena cava above the hepatic vein outflow—which can result in hepatic injury and consequent elevation of AST.

Furthermore, certain medications may also cause elevated AST levels. Since drugs are metabolized and absorbed primarily by the liver, some medications may exert hepatotoxic effects. Patients are advised to avoid alcohol consumption and other hepatotoxic exposures to facilitate clinical improvement.