Hepatic panel
Aspartate aminotransferaseAST
Aminotransferase shared between liver, muscle, heart, and red cells.
Sample
Serum
Clinical reference range
10 to 40 U/L
Adult
Conv: 10–40 U/L
Biology
What it measures
Cytosolic and mitochondrial isoforms in many tissues. Less liver-specific than ALT.
Clinical use
Why we order it
Calculate AST/ALT ratio (>2 in alcoholic liver disease, ≥1 in cirrhosis), part of FIB-4.
Differential
Causes of abnormal values
Causes of HIGH
- ↑Alcoholic hepatitis
- ↑Cirrhosis
- ↑Muscle injury / rhabdomyolysis
- ↑MI (historical)
- ↑Hemolysis (in vitro can falsely raise)
Pitfalls
Pre-analytic & interpretation traps
- !AST out of proportion to ALT in muscle injury — check CK before extensive liver workup.
Related