AST

About Test

The Aspartate Aminotransferase (AST) assay measures the levels of AST, an enzyme found in various tissues, primarily the heart and liver. This test is crucial for diagnosing and monitoring liver damage, heart conditions, and muscle disorders. Elevated AST levels may indicate liver disease, such as hepatitis or cirrhosis, heart muscle damage from a heart attack or heart failure, or muscle injury from trauma or strenuous exercise. Conversely, low AST levels are rare but could be associated with severe liver disease or malnutrition. Doctors often include AST testing as part of routine liver function panels or when evaluating patients with symptoms suggestive of heart or muscle issues.

Sample Requirements

Gold SST Tube

Stability

Serum: 4 days 4-25°C, 7 days 2-8°C.

Turnaround Time

4 hours

Gold SST Tube

Assay Interferences

Interferences (<10% up to)

Icterus: 60mg/dL (conjugated and unconjugated bilirubin)

Haemolysis: 100mg/dL haemoglobin

Lipemia: 200mg/dL intralipid

Ascorbic Acid: 30mg/dL

Other: Rarely, gammopathy, may cause unreliable results.
Sulfasalazine and sulfapyridine medication may cause false results.

Reference Range (IU/L):

0-14 days: 1.0 -150.0 / 15 days - <1 year: 1.0 -60.0 / 1-7 years: 1.0-40.0 / 7 -14 years male: 13.0 -36.0 / 7 -14 years female: 14.0 -26.0 / Adult male: <50.0 / Adult female: <35.0

Known factors:

Increased AST

  • Problem: Delay in processing
    Caused by: Overnight storage / > 6 hours delay in separation

  • Problem: Haemolysis
    Caused by: Expelling blood through needle / Vigorous shaking / Extreme Temperatures

Critical Value:

Not Applicable