Interpreting LFTs Flashcards
What pattern indicates hepatocellular damage?
ALT and AST
What pattern indicates cholestasis?
ALP, GGT and BR
What can be looked at to measure synthetic function?
Albumin
Protein
+/- platelets
What does prothrombin time measure?
Conversion of prothrombin to thrombin
Which coagulation factors ISN’T synthesised in the liver?
Factor VII
Is ALT or AST more specific for liver damage?
ALT- only produced by hepatocytes
What is an AST:ALT =1 but over 1000 indicate?
Ischaemia
What does AST:ALT >2 indicate?
Alcoholic hepatitis
What does AST:ALT <1 indicate?
Hepatocellular damage (ALT specific)
What does ALP»_space; GGT indicate?
High bone turnover
Pregnancy
What does GGT»_space; ALP indicate?
Alcohol, medications
Where is AST made?
Hepatocytes, cardiac muscle, kidney, skeletal muscle, brain, pancreas, lung, blood cells
Where is ALP made?
Biliary epithelium, bone, placenta, kidneys gut?
What are the ABCs of acute liver failure?
ABCs of Acute Liver Failure:
- Acetaminophen (paracetamol), Augmentin, Hep A, AI hepatitis
- B: hep B
- C: hep C
- D: hep D, drugs (TB drugs)
- E: esoteric causes: Wilson’s disease, Budd-Chiari syndrome
- F: acute fatty liver of pregnancy
What is the Hep B serology of a vaccinated person?
HBsAb +
No HBsAg
No HBcAb
What is the serology of someone with a past Hep B infection?
HBsAb +
HBcAb +
What is the Hep B serology of someone with an acute infection?
HBsAg +
HBcAb IgM +
What is the Hep B serology of someone with chronic infection?
HBsAg +
HBcAb IgG+
Which HepB antibody can you NOT get from vaccination?
HBcAb
Can only have HBcAb from current or previous infection
(IgM+ for acute, IgG+ for chronic)
Which Hep B antigen can you only have during infection?
HBsAg
If there is more than a 10x increase in ALT and less than a 3x increase in ALP what is the pattern?
Hepatocellular
If there is greater than a 3x increase in ALP and less than a 10x increase in ALT what is the pattern?
Cholestasis!
What can an elevated GGT mean?
If ALP is also elevated, the raised GGT is suggestive of biliary epithelial damage and bile flow obstruction
GGT can be raised in response to phenytoin and alcohol
What is the patient is jaundiced by ALT and ALP are normal?
Isolated increase in BR
Gilbert’s syndrome
Haemolysis: blood film, blood count, reticulocyte count, coombs test
In the context of jaundice what causes dark urine and normal stools
Hepatic cause
In the context of jaundice what causes dark urine AND pale stool
Post-hepatic/obstructive
What does Prothrombin Time (PT) measure?
Extrinsic pathway
