GI - liver enzymes

Question 1

Which liver enzymes reflect hepatocyte integrity?

Answer 1

ALT and AST (aminotransferases)

Question 2

Which liver enzymes reflect bile duct integrity?

Answer 2

ALP (alkaline phosphatase) and GGT

Question 3

Which out of ALT and AST is more specific to liver injury and why?

Answer 3

ALT IS MORE SPECIFIC
- ALT is found in low levels in non-hepatic tissue
- AST is found in the liver, brain, pancreas, heart, skeletal/smooth muscle and RBCs

Question 4

Which out of ALT and AST is more specific to liver injury and why?

Answer 4

ALT IS MORE SPECIFIC
- ALT is found in low levels in non-hepatic tissue
- AST is found in the liver, brain, pancreas, heart, skeletal/smooth muscle and RBCs

Question 5

___ is usually elevated in response to viral or drug related hepatic injury

Answer 5

ALT

Question 6

If there is a significant rise in ___ and the patient is unwell then this could indicate liver injury in response to alcohol

Answer 6

AST

Question 7

If AST&raquo_space;> ALT then which of the below is the most likely cause of hepatic injury?
A) alcoholic hepatitis
B) drug/viral induced hepatitis

Answer 7

A) alcoholic hepatitis

Question 8

If ALT&raquo_space;> AST then which of the below is the most likely cause of hepatic injury?
A) alcoholic hepatitis
B) drug/viral induced hepatitis

Answer 8

B) drug (e.g.- paracetamol OD)/viral-induced hepatitis

Question 9

ALP and GGT are released by the ____ epithelium

Answer 9

ALP and GGT are released by the biliary epithelium

Question 10

A rise in ___ and ___ typically reflects cholestasis/biliary obstruction

Answer 10

A rise in ALP and GGT typically reflects cholestasis/biliary obstruction

Question 11

What are the causes of raised GGT?

Answer 11

• cholestasis/biliary obstruction (e.g.- cancer)
• alcohol
• specific medications (phenytoin, isoniazid, rifampicin, glucocorticoids, barbiturates)

Question 12

What is the function of albumin

Answer 12

maintains oncotic pressure – if this is not functioning properly patients will present in an oedematous state (ascites, peripheral oedema, dyspnoea)

Question 13

What does isolated unconjugated hyperbilirubinaemia mean?

Answer 13

isolated raise in bilirubin
Gilbert Syndrome
Gilbert’s syndrome is an inherited (genetic) liver disorder that affects the body’s ability to process bilirubin - patient presents with jaundice on skin and sclera

Question 14

78 year old male presents with intermittent abdominal pain for 3 months. He also has associaed dark urine, pale stools and pruritis.

Bloods tests reveal a raise in the ALP and Gamma GT and raised bilirubin. What are your top 2 differntials and what is the next best step?

Answer 14

Differentials:
1. Cholestasis (stone)
2. Biliary blockage from cancer

Next best step = ULTRASOUND