Description
Aspartate Aminotransferase (AST) is a mitochondrial enzyme involved in the transfer of an amino group from a 2-amino- to a 2-oxoacid found in the heart, liver, skeletal muscle, and kidney and is normally present in plasma. The serum concentrations are raised when any of these tissues are damaged.
Indications
In acute viral hepatitis 20-30 fold elevations of AST are common in the early phase with a gradual return to normal over a few weeks if recovery is uneventful. As a general rule elevations of AST greater than 10 fold (400 U/L), point towards hepatocellular damage, while in obstructive jaundice, intrahepatic and extrahepatic cholestasis in cirrhosis, and in primary and secondary liver tumours, the AST level is usually below 400 U/L. Besides viral hepatitis, very high levels (> 1000 U/L) are associated with circulatory collapse and occasionally in extrahepatic obstruction. The activity of AST in human serum has also been widely measured for use as a diagnostic aid in cases of myocardial infarction.
Sample Type, Quantity & Conditions
1 ml Serum 1 ml K2-EDTA or Li-Heparin Plasma Stability: 24 Hours at 15-25 °C 7 Days at 2-8 °C
Special Precautions
Unexplained AST elevations should first be investigated with ALT and GGT
Normal Range
Male: Up to 40 U/L Up to 0.67 µkat/L Female: Up to 32 U/L Up to 0.53 µkat/L
