Page 18 - Clinical Biochemistry

• This ratio may be used to distinguish between different causes of liver damage and to
distinguish liver injury from damage to heart or muscle.
❑ AST: ALT =1

Associated with ischaemia (ischaemic necrosis and hepatitis).
❑ AST: ALT >2.5

Associated with alcoholic hepatitis.
❑ AST: ALT <1

High rise in ALT specific for Hepatocellular damage

Paracetamol

Viral hepatitis.

Alkaline Phosphatase (ALP)
• Alkaline phosphatase is an enzyme found in your bloodstream.
• ALP helps break down proteins in the body and exists in different forms, depending on
where it originates.
• Liver is one of the main sources of ALP, but some is also made in bones, intestines,
pancreas, and kidneys.
• One way to assess the etiology of the alkaline phosphatase is to perform a serologic
evaluation called isoenzymes. In the serum, two types of alkaline phosphatase isozymes
predominate: skeletal and liver.
• Another more common method to asses the etiology of the elevated alkaline phosphatase
is to determine whether the GGT is elevated or whether other function tests are abnormal (e.g.
bilirubin).
• Alkaline phosphatase may be elevated in primary biliary cirrhosis, alcoholic hepatitis,
gallstones in cholecholithiasis.

Gamma Glutamyl Transpeptidase (GGT)
• Present in the cells of the bile ducts and gall bladder.
• It is not very specific.