Necrosis Index
Transaminases: Alanine Transaminase (ALT)
Aspartate transaminase (AST)
Others: lactate dehydrogenase (LDH)
AST (formerly SGOT) is primarily a mitochondrial enzyme. ALT (formerly SGPT) is located in the cytosol. ALT is more specific than AST for liver disease. AST and ALT are only released by hepatocyte injury/necrosis.
Alcoholic liver disease: AST > ALT, since alcohol is a mitochondrial poison. Enzyme levels are rarely > 200-300 U/L.
Viral hepatitis: ALT > AST. ALT is the last enzyme to return to normal. Enzyme levels are often > 1000 U/L in acute hepatitis.
LDH is increased in cell necrosis and is a nonspecific marker of primary or metastatic tumor in the liver.