Liver Blood Tests : Liver Function Tests
A series of special blood tests can often determine whether
or not the liver is functioning properly. These tests may
also distinguish between acute and chronic liver disorders
and between hepatitis and cholestasis (bile obstruction).
The most commonly performed blood tests include:
Serum Bilirubin - Elevated levels of
bilirubin often indicate an obstruction of bile flow or a
defect in the processing of bile by the liver. Bilirubin is
produced by the liver and is excreted in the bile.
Serum Albumin - Below-normal levels of albumin, a protein
made by the liver, are associated with many chronic liver
disorders and cirrhosis.
Serum Alkaline Phosphatase - Elevated levels of alkaline
phosphatase, an enzyme found in the bile, usually indicate an obstruction
of bile flow, liver injury, or certain cancers.
Serum Aminotransferases (transaminases, SGOT, SGPT)
- These enzymes are released from damaged liver cells. They
include ALT (SGPT) and AST (SGOT). They (especially ALT) are elevated
Prothrombin Time (PT) - This test measures the time it
takes for blood to clot. Blood clotting requires vitamin K and a
protein (prothrombin) made by the liver. Liver cell damage and bile
flow obstruction can both interfere with proper blood clotting.
Gamma-glutamyl Transpeptidase (GGT) - This enzyme is released
into the blood when the liver is damaged especially by alcohol or
in bile obstruction.
Alpha-fetoprotein (AFP) - This protein is produced by the
fetal liver and testes, indicating hepatitis or cancer.
Mitochondrial Antibodies (AMA) - The presence of these
antibodies can indicate primary biliary cirrhosis, chronic active
hepatitis, and certain other autoimmune disorders.
» HAV IgM, HEV IgM - these detect active infection
by Hepatitis A or E virus
» HCV-Ab - this detects evidence of infection by HCV virus
» HCVRNA - this detects the actual presence of HCV virus
» HBsAg, HBeAg, HBV DNA - these detect infection with Hepatitis
B virus (HBV)
» Anti-HBs - the evidence of good immunity to HBV infection