Change to reference intervals for ALT and AST


Following an upgrade of the main biochemistry analyser from the Cobas 6000 to Cobas 8100 at Waikato hospital laboratory, a review of reference intervals was undertaken. The new IFCC reference methods for AST and ALT methods correlate well with Pathlab results allowing us to harmonise our reference intervals across the BOP, Lakes and Waikato regions.

Plot of Pathlab results against Waikato Hospital Laboratory results

On the 14th December we will be removing the gender specific intervals for both tests and the age-related reference intervals for ALT.

The new harmonised reference interval will be as follows:


0-2 years 0-90 U/L

2-10 years 0-70 U/L

>10 years 0-50 U/L


All ages 0-55 U/L