How are liver enzymes like ALT and AST used clinically?

Liver enzymes such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are primarily used in clinical practice to evaluate liver cell injury. When liver cells are damaged, these enzymes are released into the bloodstream, leading to increased serum levels. Elevated levels of ALT and AST serve as important biomarkers for conditions such as hepatitis, fatty liver disease, and liver toxicity due to medications or alcohol.

The interpretation of these enzyme levels allows healthcare providers to assess the extent of liver damage, make decisions regarding further diagnostic testing, and initiate appropriate treatment plans. In particular, ALT is more specific to liver injury, while AST can be elevated in conditions affecting other organs, which is why their levels are often analyzed together for a comprehensive evaluation of liver health. This clinical approach helps in diagnosing not just liver conditions but also monitoring the progression or resolution of liver disease.