Transaminases: oldies but goldies. A narrative review

Worldwide, patients are tested for acute and chronic diseases using a series of basic blood assays. The most common liver tests are serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), also called transaminases. These tests are indicators of hepatocellular injury and their increase requires further investigations. The aim of this descriptive review is to highlight and remind the importance of liver transaminases in daily practice. A systematic literature search of the main international databases was performed. We looked for papers that involved transaminases, either in the normal range or in case of increased level and focused on their use in clinical practice. A narrative review of this topic was written. Multiple studies have demonstrated that the presence of an elevated ALT was associated with increased liver-related mortality. The normal ALT level ranges from 29 to 33 IU/L in males and 19 to 25 IU/L in females. The investigations imposed by a high level of transaminases includes testing for viral hepatitis A, B, C and E, assessment for nonalcoholic fatty liver disease and alcoholic liver disease, screening for autoimmune hepatitis, hemochromatosis, Wilson's disease and alpha-1 antitrypsin deficiency. Hepatotoxic drugs consumption also should be excluded. Furthermore, the utility of transaminases is evident in the assessment of the outcome after treatment of each specific liver disease. Beside the role in the first diagnostic step of liver injuries, the utility of liver transaminases is also maintained during the follow-up of liver diseases and in their prognostic assessment.