Which enzyme is commonly elevated in acute hepatitis?

• A. ALT
• B. ALP
• C. Ammonia
• D. Ceruloplasmin

Answer: (A)

Acute hepatitis causes damage to liver cells, so enzymes that reside inside those cells spill into the bloodstream. Alanine aminotransferase, or ALT, is highly concentrated in liver cells, making it a very sensitive and relatively liver-specific marker of hepatocellular injury. When hepatocytes are damaged, ALT levels rise quickly and often to high levels, which is why ALT is the enzyme most commonly elevated in acute hepatitis.

Alkaline phosphatase tends to rise with problems involving the bile ducts or cholestasis, not primarily with acute hepatocellular injury. Ammonia is a byproduct that increases with significant liver dysfunction affecting the urea cycle, and it isn’t an enzyme used to diagnose acute hepatitis. Ceruloplasmin is a copper-transport protein and not a marker of acute hepatocellular injury.