Viral Hepatitis and Liver Disease Website Course
Evaluating Liver Test Abnormalities
Understanding the Pathophysiology of Liver Disease
for Health Care Providers
alanine aminotransferase (ALT)
Injury to hepatocytes causes ALT to leak out into the systemic circulation. ALT is more specific to the liver than AST.
aspartate aminotransaminases (AST)
Injury to hepatocytes causes AST to leak out into the systemic circulation. AST is not specific to the liver and can also be liberated during muscle injury.
cholestatic liver injury or cholestasis
Occurs when there is a disruption of bile flow (alkaline phosphatase/GGT and bilirubin levels are elevated with variable elevation of other liver enzymes). Severe injury can lead to dark urine, pruritus and jaundice.
Specialized capillary system of the liver. Unlike other capillary beds, hepatic sinusoids are leaky, allowing close contact between circulating blood and hepatocytes.
A condition where there is a disruption of bile flow. Cholestasis is classified as intrahepatic or extrahepatic
A reaction where a substrate was modified by addition of
Conjugated bilirubin. Results from glucuronidation of unconjugated bilirubin in the liver. It is water soluble and can therefore be excreted into bile.
Unconjugated bilirubin. It is not water soluble and needs to be conjugated with glucuronide before being excreted into bile. Conjugation occurs in the liver.
Product of heme degradation.
glucuronyl transferase (UDPG)
A hepatic enzyme catalyzing conjugation of glucorunide to bilirubin. Deficiency of this enzyme leads to direct hyperbilirubinemia
A genetic disease of iron metabolism, resulting in iron accumulaton and liver injury.