Alanine Aminotransferase (ALT)

Test Code

38437

CPT Codes
84460<br>Limited Access Code

Preferred Specimen

1 mL plasma collected in a plasma separator tube

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

Instructions

Centrifuge plasma specimens within 1 hour of collection, transfer plasma to a sterile, plastic, screw-capped vial(s), and ship at room temperature.

Transport Container

Sterile plastic screw-cap vial

Transport Temperature

Room temperature

Specimen Stability

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

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

Unspun plasma separator tube; Unspun green-top tube (heparinized plasma not separated from cells); Anticoagulants other than lithium heparin, sodium heparin or fluoride/oxalate; Anticoagulants other than heparin

Methodology
Spectrophotometric

Setup Schedule

Set up: Daily; Report available: 1-2 days

Reference Range

Age	Males (U/L)	Females (U/L)
< 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.