Lab 4 Liver Function tests

Question 1

What is the serum bilirubin test used to analyse

Answer 1

Liver metabolism and excretion

Question 2

What does ALT measure?

Answer 2

Hepatocellular damage

Question 3

What does ALP measure?

Answer 3

Used to assess biliary obstruction (cholestasis)

Question 4

What are the 2 forms of bilirubin

Answer 4

1. Unconjugated (indirect) = bound to albumin, not processed by liver
2. Conjugated (direct) = water-soluble and excreted in bile

Question 5

What is bilirubin?

Answer 5

Breakdown product of heme from RBCs
Metabolized by liver and excreted in bile

Question 6

Unconjugated bilirubin formula

Answer 6

Total bilirubin - conjugated bilirubin

Question 7

What does elevated bilirubin (hyperbilirubinaemia) levels indicate?

Answer 7

1. Increased RBC haemolysis
2. Liver damage/disease
3. Cholestasis.

Question 8

What causes increased unconjugated bilirubin ?

Answer 8

Haemolytic anaemia

Question 9

What causes increased conjugated bilirubin?

Answer 9

1. Cholestasis (gallstones, bile duct obstruction)

Question 10

How to determine if increased bilirubin is caused by pre-hepatic or post-hepatic reasons

Answer 10

Fractionation of bilirubin
Increased unconjugated means pre-hepatic
Increased conjugated means post-hepatic

Question 11

What does increased ALT indicate?

Answer 11

Hepatocellular damahe

Question 12

Causes of increased ALT

Answer 12

1. hepatitis
   - viral, alcoholic, autoimmune, drug-induced.

Question 13

Further testing to identify cause of increased ALT

Answer 13

Identify cause of hepatitis
- viral hepatitis panel
-pharmacology

Question 14

What does increased serum ALP concentration indicate

Answer 14

Cholestasis = obstruction of bile flow from liver