ALT - Overview: Alanine Aminotransferase (ALT) (GPT), Serum (2023)

Useful For

Suggests clinical disorders or settings where the test may be helpful

Diagnosis and monitoring of liver disease associated with hepatic necrosis

Method Name

A short description of the method used to perform the test

Photometric Rate, L-Alanine with Pyridoxal-5-Phosphate

NY State Available

Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name

Lists a shorter or abbreviated version of the Published Name for a test

Alanine Aminotransferase (ALT), S

Aliases

Lists additional common names for a test, as an aid in searching

Specimen Type

Describes the specimen type validated for testing

Serum

Necessary Information

Patient's age and sex are required.

Specimen Required

Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Specimen Minimum Volume

Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.25 mL

Reject Due To

Identifies specimen types and conditions that may cause the specimen to be rejected

Specimen Stability Information

Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Useful For

Suggests clinical disorders or settings where the test may be helpful

Diagnosis and monitoring of liver disease associated with hepatic necrosis

Clinical Information

Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Alanine aminotransferase (ALT) is present primarily in liver cells. In viral hepatitis and other forms of liver disease associated with hepatic necrosis, serum ALT is elevated even before the clinical signs and symptoms of the disease appear. Although serum levels of both aspartate aminotransferase (AST) and ALT become elevated whenever disease processes affect liver cell integrity, ALT is a more liver-specific enzyme. Serum elevations of ALT are rarely observed in conditions other than parenchymal liver disease. Moreover, the elevation of ALT activity persists longer than does AST activity.

Reference Values

Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Interpretation

Provides information to assist in interpretation of the test results

Elevated alanine aminotransferase (ALT) values are seen in parenchymal liver diseases characterized by a destruction of hepatocytes. Values are typically at least 10 times above the normal range. Levels may reach values as high as 100 times the upper reference limit, although 20- to 50-fold elevations are most frequently encountered. In infectious hepatitis and other inflammatory conditions affecting the liver, ALT is characteristically as high as or higher than aspartate aminotransferase (AST), and the ALT:AST ratio, which normally and in other condition is less than 1, becomes greater than unity. ALT levels are usually elevated before clinical signs and symptoms of disease appear.

Cautions

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Clinical Reference

Recommendations for in-depth reading of a clinical nature

Method Description

Describes how the test is performed and provides a method-specific reference

Alanine aminotransferase (ALT) activity is determined by a kinetic method using a coupled enzyme reaction where the rate of NADH consumption is measured at 340 nm. The NADH decrease is directly proportional to the ALT activity.(Package insert: Roche ALT reagent, Indianapolis, IN, January 2000)

PDF Report

Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed

Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available

The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 to 2 days

Specimen Retention Time

Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 week

Performing Laboratory Location

Indicates the location of the laboratory that performs the test

Rochester

Fees

Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

Test Classification

Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

84460

LOINC® Information

Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Setup Resources

Setup Files

Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf