Aspartate transaminase (AST) or aspartate aminotransferase, also known as AspAT/ASAT/AAT or serum glutamic oxaloacetic transaminase (SGOT), is a pyridoxal phosphate (PLP)-dependent transaminase enzyme which catalyzes the reversible transfer of an α-amino group between aspartate and glutamate.It an important enzyme in amino acid metabolism.This enzyme is found and concentrated in tissues with high metabolic activities such as the liver, heart, kidneys, skeletal muscle,brain, red blood cells and to a lower extend in the kidney and pancreas.
The combination of serum AST level and serum ALT (alanine transaminase) level including their ratio (AST/ALT ratio) which are both enzymes associated with liver parenchymal cells are commonly measured clinically as biomarkers for hepatic or liver diseases (Liver function Test) especially when there is an inflammation or injury affecting the cells of those tissues which result to a lyse of the cells releasing the enzyme AST which is picked up by the blood resulting in an increase in it serum level.
Indication of AST test
AST test is used in the evaluation of clients suspected with hepatocellular diseases
Purpose of AST test
This test is used to detect diseases such as acute hepatitis, gallstones, cirrhosis, liver congestion, metastatic tumour of the liver, infectious mononucleosis, acute pancreatitis, acute renal disease, musculoskeletal diseases or trauma.
Sign and Symptoms related to AST
- Yellow skin or eyes,condition term jaundice
- Swollen belly
- Stomach pain
- Appetite loss
- Itchy skin
- Dark-colored urine
- Light-colored poop
- Swelling in your legs and ankles
Factors that can affect the level of AST
The following factors can affect the level of AST during testing
- Pregnancy: This can cause decreased AST levels.
- Exercise: This may increase AST levels.
- Also some drugs may cause increases in AST like antihypertensives, cholinergic agents, anticoagulants, contraceptives, opiates, and statins).
Result and clinical Significance of AST
|Lower level||Higher level|
|Acute renal disease||Liver diseases such as hepatitis, hepatic cirrhosis, drug-induced liver injury, hepatic metastasis, mononucleosis|
|Beriberi||Skeletal muscle diseases such as muscle trauma, surgery, burns, muscular dystrophy, heat stroke|
|Diabetic ketoacidosis||Other diseases such as acute hemolytic anemia and acute pancreatitis|
|Chronic renal dialysis||xx|
Reference Range of AST
Note Adapted from Pagana, K. D., and T. J. Pagana. Mosby’s Canadian Manual of Diagnostic and Laboratory Tests. 1st ed. Toronto, ON: Elsevier Canada, 2013.