A systematic review of data on biological variation for alanine aminotransferase, aspartate aminotransferase and γ-glutamyl transferase

Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and ?-glutamyl transferase (GGT) are enzymes measured in serum or plasma to investigate liver disease. The aim of this work is to assess the validity of published biological variation (BV) data currently available for these enzymes