Liver
Alanine aminotransferase (ALT)
Alanine aminotransferase (ALT) is an enzyme concentrated in liver cells that leaks into the blood when those cells are injured. It is one of the core liver function tests, used to screen for and monitor hepatocellular damage.
Why it is measured
ALT is relatively specific to the liver, so a raised level is a useful early flag for hepatocellular injury from causes such as fatty liver, viral hepatitis, alcohol or medicines. Measuring it at the point of care lets clinicians triage liver health quickly in primary care, pharmacy and remote settings without waiting for a central laboratory.
| Typical range | Indicative adult range approximately 10 to 40 U/L, with upper limits commonly higher in males (up to about 50 U/L) than females (about 35 U/L). Ranges vary by analytical method, temperature standardisation and analyser, so always apply the reporting device's or laboratory's own reference interval. |
|---|---|
| Sample | Capillary or venous whole blood, serum or plasma, depending on the analyser. Many cartridge or disc systems accept a small fingerstick or whole-blood volume directly, with no separate spin step. |
| Turnaround | Typically around 5 to 15 minutes per run at the point of care, depending on the analyser and the size of the panel. |
Point of care devices that report it
- Abaxis Piccolo Xpress (Comprehensive Metabolic Panel and Liver Panel Plus reagent discs)
- Samsung LABGEO PT10 (Hepatic panel)
- Roche Reflotron (single-test dry-chemistry strip)
- Seamaty SD1 (dry-chemistry liver panel)
Questions, answered
Does point-of-care ALT match central laboratory results?
POCT ALT correlates well with laboratory analysers, but small systematic differences between methods are common, so results should be read against the device's own reference range. Confirmatory laboratory testing is sensible for borderline or clinically important values. This is general operational guidance, not advice on any individual result.
Why is ALT usually reported alongside AST?
ALT is more liver-specific, whereas AST is also found in muscle, heart and other tissues, so reporting them together (and considering the AST/ALT pattern) gives a fuller picture of the type of injury. Most POCT liver panels include both, plus markers such as ALP, bilirubin and albumin.
What can affect an ALT result at the point of care?
Pre-analytical factors such as haemolysis, sample type, delay since collection and recent strenuous exercise can shift values, and methods calibrated at different temperatures may read differently. Following the manufacturer's sampling and quality-control steps helps keep results reliable and comparable over time.