Liver Function Tests Flashcards
What protein components are measured in LFTs?
- Total protein
- Albumin
- Globulins (TP - albumin)
Which two liver enzymes, if elevated, indicate cholestasis?
Alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT)
Which two liver enzymes, if elevated, indicate some form of hepatocellular injury or inflammation?
Alanine aminotransferase (ALT) and aspartate aminotransferase (AST)
What are the 4 key liver enzymes?
- Alkaline phosphatase (ALP)
- Gamma glutmyl transferase (GGT)
- Alanine aminotransferase (ALT)
- ASpartate aminotransferase (AST)
What do liver enzymes tell you about function?
Very little - there are many causes of changes in liver enzymes/protein/bilirubin besides impaired liver function
LFT presents with massively increased ALT and AST.
What is the most likely cauase?
Acute hepatitis, e.g. Acute viral hepatitis.
Out of ALT and AST, which is more specific to the liver?
AST is also found in skeletal and cardiac muscle.
Therefore, isolated AST increase may indicate skeletal/cardiac muscle origin (but not always)
What does mildy raised ALT and AST most likely indicated?
Chronic hepatitis e.g. Non-alcoholic fatty liver disease.
Milder increase in liver enzymes.
What does a raised ALT and AST paired with significantly raised GGT indicate?
Alcoholic hepatitis.
What does a raised ALP and GGT indicate?
Some form of cholestasis, e.g. PBC, PSC, gallstone biliary obstruction
What is the difference in causes of conjugated hyperbilirubinaemia and unconjugated hyperbilirubiaemia?
Conjugated implies spillage of contents from the liver, e.g. biliary obstruction.
Unconjugated implies haemolysis or defect in hepatic conjugation
LFT presents with decreased total protein (decreased albumin and globulins).
BIlirubin is raised.
What does this most likely indicate?
Chronic liver disease, including cirrhosis of the liver.
LFT presents isolated raised GGT.
What is the most likely cause?
Acute alcohol poisoning.
GGT production can be induced by alcohol ingestion.
LFT presents with raised total protein, normal albumin and raised globulins.
What does this indicate?
Monoclonal gammopathy, most likely myeloma.
