Evaluating Liver Test Abnormalities
Understanding the Pathophysiology of Liver Disease
for Health Care Providers
Tests of Hepatocellular Injury
Aspartate Aminotransferase (AST)
AST was formerly known as SGOT (serum glutamic oxaloacetic transaminase). In addition to hepatocytes, AST can be found in cardiac and skeletal muscle as well as blood. The co-existing elevation of creatinine kinase or aldolase may help differentiate the muscle origin of AST from the hepatic origin.
Alanine Aminotransferase (ALT)
ALT was formerly known as SGPT (serum glutamic pyruvic transaminase). Although a small amount of ALT is present in the cardiac and skeletal muscles, the majority of this enzyme is found in the mitochondrial compartment of the hepatocytes. ALT elevation is therefore more specific to the liver than AST.
*AST and ALT are commonly called collectively as hepatic transaminases, or more appropriately, hepatic aminotransferases.
Note: Regardless of the facility upper limit of normal, the American Gastroenterology Association recommends that an ALT >25 in women and >35 in males should be reviewed.