Which statement is true about ALT and AST in hepatocellular injury?

Which statement is true about ALT and AST in hepatocellular injury?

• A. ALT is more specific than AST
• B. AST is more liver-specific than ALT
• C. ALP is more liver-specific than ALT
• D. GGT is more liver-specific than ALT

Answer: (A)

ALT is more liver-specific than AST. Alanine aminotransferase is concentrated mainly in liver cells, so when hepatocytes are damaged, ALT rises prominently as a more direct indicator of liver injury. AST, by contrast, is found in many tissues—heart, skeletal muscle, kidney, brain, and red blood cells—so its elevation can reflect injury outside the liver as well. This distribution makes ALT a more specific marker for hepatocellular injury. The other enzymes mentioned are less specific for hepatocyte damage; ALP and GGT relate more to biliary or cholestatic processes and can be elevated for reasons beyond pure hepatocellular injury.

ALT is more liver-specific than AST. Alanine aminotransferase is concentrated mainly in liver cells, so when hepatocytes are damaged, ALT rises prominently as a more direct indicator of liver injury. AST, by contrast, is found in many tissues—heart, skeletal muscle, kidney, brain, and red blood cells—so its elevation can reflect injury outside the liver as well. This distribution makes ALT a more specific marker for hepatocellular injury. The other enzymes mentioned are less specific for hepatocyte damage; ALP and GGT relate more to biliary or cholestatic processes and can be elevated for reasons beyond pure hepatocellular injury.