Aspartate Aminotransferase (AST/SGOT)
CPT Code(s):
84450
Turnaround Time:
4 hours
Specimen Requirements
Preferred Specimen:
Serum
Minimum Volume:
1.0 mL
Transport Container:
Serum Separator Tube (SST) or Red Top Tube
Transport Temperature:
Room Temperature
Collection Instructions:
Allow blood to clot completely prior to centrifugation. Separate serum from cells within 45 minutes of collection.
Rejection Criteria:
Citrate, Fluoride,Sodium Heparin, or EDTA plasma specimen; gross hemolysis; lipemia; improper labeling
Stability Criteria
Room Temperature:
3 days
Refrigerated:
7 days
Frozen:
30 days
Clinical Significance
The Aspartate Aminotransferase (AST), also known as Serum Glutamic Oxaloacetic Transaminase (SGOT), test holds specific clinical significance and diagnostic use in the field of clinical chemistry and hepatology. This test measures the level of AST, an enzyme found predominantly in the liver and other organs, in a patient's blood.
The clinical significance and diagnostic use of AST include:
1. Evaluation of Liver Function: AST is commonly used as a marker of liver function and hepatocellular injury. Elevated AST levels can indicate liver damage or disease, such as viral hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease (NAFLD), drug-induced liver injury, or liver cirrhosis. AST is often performed in combination with other liver function tests to assess the overall liver health and assist in the diagnosis and management of liver diseases.
2. Differentiation of Liver Disorders: AST, along with other liver function tests and clinical evaluation, helps differentiate between different liver disorders. AST levels are typically elevated in acute liver injury or inflammation, such as in viral hepatitis or acute liver damage due to drug toxicity. AST, in conjunction with other liver enzymes and diagnostic tests, aids in distinguishing between different types of liver diseases and guiding appropriate treatment strategies.
3. Monitoring Drug Toxicity: Certain medications and drugs can cause liver toxicity as a side effect. AST is useful in monitoring the liver function of patients taking potentially hepatotoxic medications, such as statins, acetaminophen, or antiretroviral drugs. Regular monitoring of AST levels helps healthcare providers detect drug-induced liver injury early, adjust medication dosages, or switch to alternative therapies as necessary.
4. Prognostic Indicator in Liver Diseases: In patients with liver diseases, AST levels can serve as a prognostic indicator of disease severity and progression. Higher AST levels may be associated with more advanced liver damage, fibrosis, or cirrhosis. Serial measurements of AST over time can provide valuable information about the response to treatment and the overall prognosis of liver diseases.
5. Cardiac Evaluation: While AST is predominantly found in the liver, it is also present in other tissues, including the heart. Elevated AST levels can indicate cardiac muscle damage, such as in acute myocardial infarction (heart attack) or heart muscle inflammation (myocarditis). AST, along with other cardiac biomarkers and diagnostic tests, assists in the evaluation of cardiac health and the diagnosis of related conditions.
In summary, the AST (SGOT) test has specific clinical significance and diagnostic uses in assessing liver function, differentiating liver disorders, monitoring drug toxicity, providing prognostic information in liver diseases, and evaluating cardiac health. By measuring AST levels, healthcare providers gain valuable insights into liver and cardiac health, aiding in the diagnosis, management, and monitoring of various conditions and guiding appropriate treatment decisions.