Alanine aminotransferase, usually referred to as ALT, is an enzyme that is concentrated primarily in the liver. Another name of ALT is SGPT, means Serum Glutamic Pyruvic Transaminase. High levels of these enzymes can be a sign that the liver is injured or irritated, and the enzymes are leaking out of the liver cells. Serum/EDTA plasma can be used as specimen