Page 17 - Clinical Biochemistry 08PB804

• Sometimes referred to as the SGPT and SGOT respectively. These are enzymes that are
indicators of liver cell damage.
• The other frequently used liver enzymes are the ALP and gamma-glutamyltranspeptidase
(GGT) that indicate obstruction to the biliary system, either within the liver or in the larger
bile channels outside the liver.
Transaminases
• These enzymes are involved in the transfer of amino groups to ketoglutaric acid. AST and
ALT are elevated in syndromes of hepatocellular injury.
• Aminotransferase elevation is often the first biochemical abnormality detected in a patient
with viral, drug-induced or alcoholic hepatitis.
• Normal range varies by laboratory but is generally (0 - 35 U/L).
Alanine Aminotransferase (ALT)
• ALT is an enzyme produced within the cells of the liver.
• The level of ALT abnormality is increased in conditions where cells of the liver have been
inflamed.
• As the cells are damaged, ALT leaks into the blood stream leading to a rise in serum levels.
• Any form of hepatic cell damage can result in an elevation in the ALT.
• ALT is the most sensitive marker for liver cell damage.
Aspartate Aminotransferase (AST)
• This enzyme also reflects damage to the hepatic cell.
• It is less specific for liver disease.
• The blood test for aspartate aminotransferase (AST) is usually used to detect liver damage.
• It is often ordered in conjunction with another liver enzyme (ALT).
• AST and ALT are considered to be two of the most important tests to detect liver injury.
• Although ALT is more specific for the liver than is AST and is more commonly increased
than is AST. Sometimes AST is compared directly to ALT and an AST/ALT ratio is calculated.