Clinical Biochemistry 1

Question 1

Where is the liver located?

Answer 1

Right hypocardium + extends into epigastrium

Question 2

What is structure of the liver?

Answer 2

Left + right lobe

Question 3

What is the left + right lobe of liver separated by?

Answer 3

Falciform ligament

Question 4

Describe clinical biochem for the liver

Answer 4

Not completely specific to liver

Just says if liver dysfunction

Question 5

What are the standard parameters?

Answer 5

Alkaline phosphate (AP)
Alanine aminotransferase (ALT)
Aspartate aminotransferase (AST)
Gamma-glutamyl transferase (GGT)
Bilirubin
Albumin 
Total protein

Question 6

What are the two enzyme measurements?

Answer 6

Soluble cytoplasmic enzymes (AST + ALT)

Membrane-associated enzymes (AP + GGT)

Question 7

What is AP produced by?

Answer 7

Hepatocytes

Question 8

When does AP increase?

Answer 8

Liver disease - hepatitis, cholestasis
Bone disease - even bone growth in teens
Pregnancy - end + breast feeding

Question 9

What are the aminotransferases?

Answer 9

ALT + AST

Question 10

Where is AST?

Answer 10

Liver, heart, pancreas, lungs, RBCs + skeletal muscle

Question 11

Where is ALT?

Answer 11

Liver

= more specific

Question 12

What type of enzymes are aminotransferases?

Answer 12

Intracellular cytoplasmic enzymes

Question 13

When does AST + ALT increase?

Answer 13

Hepatic damage

Question 14

Where is GGT?

Answer 14

High conc in liver, kidneys, pancreas, intestine + prostate

Question 15

What is GGT an indicator of?

Answer 15

Hepatobiliary disease in conjunction with raised AP

Question 16

What is half life of albumin?

Answer 16

20 days = reflect long term picture of disease

Question 17

In cirrhotic patients what happens to albumin?

Answer 17

Decrease by 50%

Question 18

Why is albumin important?

Answer 18

Most acidic drugs are strongly bonded to albumin

Question 19

When is albumin conc altered?

Answer 19

Crohn’s disease, malnutrition, malignancy + nephrotic syndrome

Question 20

What is major function of liver?

Answer 20

Manufacture of plasma proteins

Question 21

What are the main plasma proteins?

Answer 21

Albumin + clotting factor

Question 22

What is INR?

Answer 22

International Normalised Ratio

Question 23

What is the liver responsible for?

Answer 23

Production of clotting factors

Question 24

When are INRs abnormal?

Answer 24

INR > 1.2

Question 25

When is INR elevated?

Answer 25

Chronic or acute liver disease

Question 26

What can INR also be used in + why?

Answer 26

Paracetamol poisoning = marker of hepatocellular damage

Question 27

Describe bilirubin metabolism

Answer 27

Unconjugate bilirubin + albumin Unconjugated bilirubin transported with ligand Conjugated to glucuronic acid Conjugated bilirubin to small intestine Bacterial proteases convert to urobilinogen Back to blood then liver Urobilinogen excreted in urine

Question 28

What % of bilirubin is converted to urobilinogen?

Answer 28

``` 10% = portal vein = hepatocyte = urobilinogen 90% = faeces ```

Question 29

What is jaundice?

Answer 29

Increase production of bilirubin decrease uptake Decrease metabolism Decrease excretion

Question 30

When is bilirubin elevated?

Answer 30

Unconjugated hyperbilirubinemia | Conjugated hyperbilirubinemia

Question 31

What is unconjugated hyperbilirubinemia?

Answer 31

Haemolysis | Gilberts syndrome

Question 32

What is conjugated hyperbilirubinemia?

Answer 32

Intra/extra-cellular cholestasis Acute hepatitis Cirrhosis Jaundice

Question 33

What do you need to consider?

Answer 33

``` LFT profile as a whole Other clinical factors Dynamic shifts over time Normal = doesn't mean healthy Abnormal = doesn't mean diseased ```