An alanine transaminase test is a blood test used to measure the ALT enzyme levels in the bloodstream, says WebMD. When the liver is damaged, the enzyme level in the blood is higher than normal.
The ALT enzyme is mainly found in the liver, but it is also present in the kidneys, heart and pancreas. The bloodstream only exhibits traces of the enzyme, according to Mayo Clinic. In cases of liver damage or disease, the level of ALT rises in the blood.
The aspartate transaminase test is also a blood test that checks for liver disease. An increase of AST enzyme in the body also shows damage or illness of the liver. The enzyme’s primary function is metabolizing alanine, an amino acid, states Mayo Clinic.