Alanine Aminotransferase (ALT)

Test Code

823

CPT Codes
84460

Preferred Specimen

1 mL serum collected in a serum separator tube (SST)

Patient Preparation

The assay manufacturer, Beckman Coulter, warns that patients treated with sulfasalazine may generate false low results for ALT.

Minimum Volume

0.5 mL

Other Acceptable Specimens

Plasma collected in: sodium heparin (green-top) tube, or lithium heparin (green-top) tube

Transport Temperature

Refrigerated (cold packs)

Specimen Stability

Room temperature: 72 hours
Refrigerated: 5 days
Frozen: Unacceptable

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Anticoagulants other than heparin

Methodology
Spectrophotometry (SP)

Setup Schedule

Set up: Daily; Report available: Next day

Limitations

Trauma to striated muscle, tissue, rhabdomyolysis, polymyositis, and dermatomyositis may produce increased results. Hemolyzed samples may yield elevated results. Some illegal drugs (cocaine, anabolic steroids, ecstasy) may also produce increased results.

Reference Range

	Male (U/L)	Female (U/L)
<1 Month	3-25	3-25
1-11 Months	4-35	3-30
1-3 Years	5-30	5-30
4-12 Years	8-30	8-24
13-15 Years	7-32	6-19
16-19 Years	8-46	5-32
≥20 Years	9-46	6-29

Clinical Significance

Alanine Aminotransferase (ALT) measurements are particularly useful in the diagnosis and management of certain liver diseases, e.g., viral hepatitis and cirrhosis. ALT activity in tissue is generally much lower than aspartate aminotransferase (AST) activity and is found in highest concentrations in the liver. Significant elevations of ALT occur only in diseases of the liver. ALT is often measured in conjunction with AST to determine whether the source of the AST is the liver or the heart. ALT is normally not elevated in cases of myocardial infarction, i.e., a normal ALT, in conjunction with an elevated AST, tends to suggest cardiac disease. However, slight elevations of ALT may occur if an infarct destroys a very large volume of heart muscle.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.