Liver Function Test (LFT)
All are enzymes!
AST = Aspartate Transaminase
ALT = Alanine Transaminase
ALP = Alkaline phosphatase = non specific = produced in liver, bones (from bone formation), intestines, placenta
GGT = Gamma glutamyl transferase
Interpretations
HI AST/ ALT: Hepatocelluar damage (ALT > 3XALP)
HI ALP only: Bones (Paget's, vit D deficiency, mets), placenta (pregnancy), intestines
HI ALP + GGT: cholestasis (ALP > 3xALT), alcohol, meds
HI GGT only: Alcohol
HI Bilirubin: Hepatotoxic/ Cholestasis
LO Albumin: severe liver damage, pregnancy, inflammation, protein losing states, malnutrition
Causes of:
NOTE: higher levels do not mean increased severity
Source
http://www.racgp.org.au/download/documents/AFP/2011/March/201103coates.pdf
AST = Aspartate Transaminase
ALT = Alanine Transaminase
ALP = Alkaline phosphatase = non specific = produced in liver, bones (from bone formation), intestines, placenta
GGT = Gamma glutamyl transferase
Interpretations
HI AST/ ALT: Hepatocelluar damage (ALT > 3XALP)
- inc 10x = acute (eg acute viral hepatitis, hypoxia)
- inc mildly = inf, alcohol, fatty liver, meds
- inc AST: ALT = alcohol
HI ALP only: Bones (Paget's, vit D deficiency, mets), placenta (pregnancy), intestines
HI ALP + GGT: cholestasis (ALP > 3xALT), alcohol, meds
HI GGT only: Alcohol
HI Bilirubin: Hepatotoxic/ Cholestasis
- Usually conjugated in adults
- Unconjugated: Gilbert's Syndrome (x2-3 of ref)/ Haemolysis
LO Albumin: severe liver damage, pregnancy, inflammation, protein losing states, malnutrition
Causes of:
- Hepatocellular damage: infection, fatty liver, alcohol, meds (paracetamol), metal overload (FE, Cu), hypoxia, autoimmune
- Cholestasis: Biliary obstruction (gallstones), meds (erythromycin, oestrogen), pregnancy, infiltration (malignancy)
NOTE: higher levels do not mean increased severity
Source
http://www.racgp.org.au/download/documents/AFP/2011/March/201103coates.pdf