Serum Transaminases (Aminotransferases)

Aminotransferases (Transaminases)

  • Aspartate Aminotransferase (AST)
    • Formerly Called Serum Glutamate-Oxaloacetate Transaminase (SGOT)
  • Alanine Aminotransferase (ALT)
    • Formerly Called Serum Glutamate-Pyruvate Transaminase (SGPT)

Origin of Transaminases (Aminotransferases)

  • Liver: AST and ALT
  • Cardiac and Skeletal Muscle: AST only
  • Thyroid: AST only


Diagnosis of Liver Disease

  • Sensitivity/Specificity of Transaminases (Especially ALT) for the Differentiation of Liver Disease from Other Disorders Depends on the Cutoff Value Chosen to Define an Abnormal Result
    • ALT Levels Correlate with the Degree of Abdominal Adiposity Vary Between the Sexes
    • AST and ALT Upper Limits of Normal Vary Between Laboratories: due to differing reference standards used
    • Optimal ALT Cutoff Value (Male): 29 IU/L (Hepatology, 2012) [MEDLINE]
    • Optimal ALT Cutoff Value (Female): 22 IU/L (Hepatology, 2012) [MEDLINE]


  • Upper limits of normal for alanine aminotransferase activity in the United States population. Hepatology. 2012;55(2):447 [MEDLINE]