Usual transaminase values: should they be reviewed and adjusted?

Area of Science:

• Clinical Biochemistry
• Enzymology

Background:

• Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are key intracellular enzymes crucial for amino acid metabolism.
• Their activity measurements are fundamental in clinical diagnostics for liver disease screening, diagnosis, and monitoring.

Purpose of the Study:

• To investigate the variability of ALT and AST reference values.
• To highlight the influence of analytical methods and individual patient characteristics on these reference values.

Main Methods:

• Analysis of existing literature on ALT and AST reference value variations.
• Comparison of reported values across different analytical methods and demographic groups.

Main Results:

• ALT and AST reference values significantly vary with analytical methods, gender, body mass index, and age.
• No significant variation was observed based on ethnicity or the specific analyzer used.
• Supplementing samples with pyridoxal phosphate impacts ALT reference values.

Conclusions:

• Clinical laboratories must update ALT and AST reference values considering sex, BMI, age, and analytical methods.
• Standardization of methods, including pyridoxal phosphate supplementation, is recommended for inter-laboratory result comparability.