Interpretations Of Liver Function Tests

Question 1

What are the major functions of the liver

Answer 1

Metabolisma and excretion: bilirubin and bile acids, drugs, foreign bodies, steroid hormones
Carbohydrate metabolism: gluconeogenesis
Protein metabolism: synthesis of urea from ammonia
Fat metabolism: cholesterol synthesis, fatty acid synthesis, bile acid synthesis
Catabolic site for many of the hormones: vitamind, insulin, glucagon, oestrogens, gh, glucocorticoid
Contribution to immune response: lined by kupffer cells, cytokines

Question 2

What are the symptoms of liver disease

Answer 2

Jaundice
Abdominal distension
Ankle swelling due to fluid accumulation
Haemetemesis due to portal hypertension
Pale stool and dark urine due to dysregulaiton in bilirubin

Question 3

What are the sources of bilurubin

Answer 3

Haemoglobin catabolism
Red cell precurosrs
Myoglobulin
Cytochrom
Peroxidase

Question 4

What is the metabolism of bilirubin

Answer 4

1. Unconjugated bilirubin is taken to the liver to become conjugated
2. Conjugated bilirubin is taken by the biliary system into the second part of the duodenum (small intestine)
3. Conjugated bilirubin is converted to urobilinogen by bacterial proteases
4. Urobilinogen is coverted to sterobilin which taken into the faeces that gives stools its brownish colour
5. Remaining Urobilogen is taken by the portal vein into the liver and then to the kidneys to become exreted in the urine

Question 5

What are the causes of hyperbilirubinaemia

Answer 5

Pre hepatic: haemolytic condition that causes high unconjugated bilirubin
Hepatic: unconjugated and conjugated biliurubin is hihg
Post hepatic: conjugated bilirubin is high due to flow obstruction

Question 6

When is jaundice recognised

Answer 6

When bilirubin levels are more than 50micro moles per litre

Question 7

What are the pre hepatic causes of unconjugated hyperbilirubinaemia

Answer 7

• High production of haem: haemoltyc anaemia, rapid turnover in neonates
• decreased delivery of unconjugated bilirubun in plasma due to right sided congested cardiac failure or portocaval shunt
• decreased uptake of unconjugated biluribin to the liver due to compettive inhibitiron of drugs, gilberts syndrome, sepsis

Question 8

What are the hepatic causes of conjugated bilirubinaemia

Answer 8

• decreased secretion of conjugated bilirubin due to: hepatitis, durgs, intrahepatic obstruction, primary biliary cirrhosis, tumout, drugs, granuloma

Question 9

What are the post hepatic causes of conjugated hyperbilirubinaemia

Answer 9

Extrahepatic obstruction: gallstones, carcinoma of the pancreas head, structure, sclerosing cholangitis, atresia

Question 10

What are the hepatocellular enzymes

Answer 10

AST

ALT

Question 11

What are the hepatobilary enzymes

Answer 11

ALP

Gamma GT

Question 12

Where can ALP be found in

Answer 12

Bone
Placenta
When bone is remodelled after a fracture

Question 13

In a liver function test what are the plasma proteins that we can have a look at

Answer 13

Albumin
Immunoglobulin
Caeruloplasmin- decreased in wilsons disease
Alpha anti trypsin- protease inhibitors which deficiency increases damage to liver and lungs
Coagultion proteins- we use INR

Question 14

Is unconjugated bilirubin soluble in water

Answer 14

no

Question 15

Is unconjugated bilirubin present in urine

Answer 15

no because its unsoluble to urine

Question 16

Why is a post hepatic picture likelt ot five dark urine

Answer 16

Becuase there is an increase in conjugated bilirubin in the urine

Question 17

What does a positive bilirubin in urine suggest

Answer 17

High conjugated bilirubin so it is hepatic and post hepatic

Question 18

What does a higher AST, ALT than GGT and ALP suggest

Answer 18

hepatocellular injury

Question 19

What does higher ALP and GGT than AST and ALT suggest

Answer 19

Cholestasis picture

Question 20

If there is low albumine what doe sthis indicate

Answer 20

Chornic and severity

Question 21

If there is high pt and INR what does this indicate

Answer 21

Severity of cholestasis

Question 22

What does increase in GGT alone suggest

Answer 22

Alcohol

Use of more drugs such as antibiotics

Question 23

What does an increase in ALP on its own suggest

Answer 23

Bone origin problem e.g bone mets

Question 24

What does normal urine and normal stools suggest

Answer 24

Pre hepatic cause

Question 25

What cause does dark urine and normal stool suggest

Answer 25

Hepatic cause

Question 26

What does dark urine and pale stools suggest

Answer 26

Post hepatic cause

Question 27

What is gilberts syndrome

Answer 27

impaired conjugation