ALT is a specific indicator of which organ damage?

Study liver anatomy and function with our medical students test. Engage with detailed multiple choice questions, each with hints and explanations. Prepare effectively for your test!

ALT, alanine aminotransferase, is an enzyme concentrated mainly in liver cells. When hepatocytes are damaged, ALT leaks into the bloodstream, so a rise in ALT is a signal of liver injury. This makes ALT a liver-specific indicator, more so than other enzymes that are also present in heart or muscle. While AST can also rise with liver injury, it is not as liver-specific because it is found in heart and skeletal muscle as well. So when you see elevated ALT, think hepatocellular damage—as seen in hepatitis, fatty liver disease, or drug-induced liver injury—where the degree of elevation generally reflects how much hepatocyte injury has occurred.