Liver Function Tests Flashcards
Name 5 things measured in LFTs
- Albumin
- ALT (Alanine to Glutamate, Alpha-keto glutarate)
- AST (Glutamate to Aspartate, Oxaloacetate)
- ALP
- Bilirubin
Of the Hepatic Enzymes, which one is more specific to liver?
What structures can the other one be found be in?
ALT- More specific to liver
AST- Also in Skeletal muscle, Cardiac muscle, RBCs
(Skeletal muscle damage->raised CK, cardiac muscle damage-> raised troponin, RBC damage-> FBC)
Which hepatic enzyme rises more in Acute and Chronic liver damage?
Acute liver damage- ALT rises more
Chronic liver damage- AST rises more
Where is Alkaline Phosphatase (ALP) found?
When can it be raised?
- Found in cells lining bile ducts
- Damage/ obstruction of bile ducts (Cholestasis- Bile duct obstruction)
- In children/ teens still growing (Bone turnover)
- Bone malignancy
How can we test to see if raised ALP is coming from liver?
Use Gamma-GT (GGT), to confirm if raised ALP is from bile duct cells
Why is raised Bilirubin particularly dangerous in neonates?
Unconjugated Bilirubin can cross Blood Brain Barrier leading to deficits/ developmental abnormalities
Suggest 3 occasions LFTs would be measured
- In a healthy patient before starting on a course of medication
- To monitor liver conditions
- If any liver pathology is suspected
Can LFTs tell you jaundice is present?
No, jaundice can only be diagnosed by looking at patient
What does raised ALP, normal AST and ALT suggest?
Obstructive pattern (of bile duct)
What does normal ALP, raised AST and ALT suggest?
Hepatocellular damage
What does raised ALP, AST, ALT suggest?
What is the most likely cause?
Mixed picture of obstruction and hepatocellular damage
Most likely due to liver metastases
Why can we test Gamma GT?
To rule out bone-related causes of raised ALP
