Removing AST from liver function panels

In many New Zealand Laboratories AST is no longer part of the liver function panel. To harmonise liver function testing (LFT) across all Awanui labs, from 1 October 2024 AST will no longer form part of the standard liver function test panel. However, AST will still be able to be requested separately as either a stand-alone test or an add-on.

The standard Awanui LFT panel will consist of:

  • Total bilirubin
  • Total protein
  • Albumin
  • Globulin
  • ALP
  • GGT
  • ALT

Serum ALT level is more sensitive and specific than AST level for liver injury and there is little value in ordering both together in the absence of high clinical suspicions for liver injury. Measurement of ALT level is recommended as the primary test for investigating hepatocellular injury. Isolated elevations in AST level can occur with injury to other tissue including liver, heart, and muscle, and commonly occurs because of haemolysis during blood collection and specimen processing for analysis.

The most common causes of hepatocyte injury include non-alcoholic fatty liver disease; viral hepatitis; alcohol, drug or other toxic liver disease; hemochromatosis; and autoimmune disease.

Removing AST from liver function panels is part of our test curation review which is being led by Awanui Labs Clinical Pathology team. It is important for laboratories to continually review the use of specific tests as test usefulness/value can change over time. In the coming months we will advise you of further changes we will be making to our testing panels.

If you have any questions, please contact me via the details below.

Ngā mihi

Richard Steele
Chief Medical Officer
T: 04 381 5900
E: richard.steele@awanuilabs.co.nz