Alanine transaminase

Alanine transaminase or ALT is (mostly) a liver enzyme. The spillover of this enzyme into blood is routinely measured as a marker of liver-cell damage. This helps distinguish liver disease caused by liver-cell damage from diseases caused by problems in biliary ducts[?].

ALT is markedly raised in hepatitis and other acute liver damage. The enzyme AST has a similar role, but this enzyme tends to be found in other tissues, such as heart, and it is not as specific to the liver.