Liver function tests

Question 1

What do liver tests measure?

Answer 1

• Alanine aminotransferase
• Albumin
• Bilirubin
• Alkaline phosphatase
• Gamma glutamyltransferase
• Asparatate aminotransferase
• Globulin or total protein

Question 2

How to measure liver injury

Answer 2

ALT, AST, alk phos, gamma-GT

Question 3

How to measure liver synthesis

Answer 3

Albumin

Question 4

How to measure liver excretion

Answer 4

Bilirubin

Question 5

jaundice and bilirubin

Answer 5

• Pre-hepatic: haemolysis
• Hepatic: hepatocyte impairment
• Post-hepatic: biliary stasis
• Unconjugated bilirubin is indirect, conjugated is direct
• Unconjugated bilirubin is protein-bound so shouldn’t appear in urine

Question 6

Chronic hep C

Answer 6

• Blooc-blood contact (needle sharing)
• Majority will not clear virus and develop infection
• Leads to cirrhosis or hepatocellular carcinoma
• Liver function test and ascites indicate cirrhosis
• Raised gamma GT suggest alcohol is additional factor
• Management involves monitoring extent of injury and consider antivirals
• AST>ALT
• Increased gamma GT

Question 7

Alcoholic cirrhosis with GI bleed

Answer 7

• Normally reaches advanced stage befroe seeking help
• Elevated gamma GT = alcohol
• Upper GI bleed, examination findings, hyponatraemia and AST
• Can’t form clot
• Stent through jugular vein to link portal and hepatic vein - shunts fluid past obstruction
• Shunts bypass liver - means that ammonia is not metabolised and can reach brain
• Low BP, increased HR
• Ascites
• Increased gamma GT
• Decreased Hb

Question 8

Gilbert’s syndrome

Answer 8

• UDP-glucuronosyltransferase which conjugates bilirubin is defective
• Leads to elevated bilirubin levels and mild jaundice
• Symptoms are few, may be unnoticed for years
• Exacerbated by illness, fasting or extreme exercise
• Increased unconjugated bilirubin

Question 9

Spherocytosis

Answer 9

• Haemolytic crisis
• RBC proteins abnormal - inability to adjust shape to pass through capillaries
• Cells are destroyed by spleen
• Elevated reticulocyte count = increased RBC turnover
• Mild forms can be delayed until adult life
• LUQ pain from spleen
• Splenomegaly
• Increased unconjugated bilirubin
• Decreased Hb
• Increased reticulocytes

Question 10

Carcinoma of pancreatic head

Answer 10

• Obstructs bile duct
• Palpable gall bladder = malignancy
• Bilirubin is conjugated and spills into urine = dark colour
• Liver enzymes (ALP) are raise and INR may be high due to malabsorption of vit K in absence of bile salts in intestine
• Build up of bile salts
• Increased conjugated bilirubin, increased INR

Question 11

HELLP syndrome

Answer 11

• Advanced pre-eclampsia
• Haemolysis, elevated liver enzymes, low platelet count
• Hypertension, oedema, proteinuria, headache, epigastric pain and poor foetal growth
• Baby needs to be delivered ASAP
• Platelet transfusion needed
• High mortality rate
• Increased BP, oedema, headaches, decreased Hb

Question 12

Primary biliary cirrhosis

Answer 12

• Raised gamma GT and ALP = biliary damage
• Strongly raised AMA = primary biliary cirrhosis
• ANA raised in auto-immune hepatitis
• Primary biliary cirrhosis inflames intra-hepatic biliary ducts
• Bear bile salts
• Dark urine
• Splenomegaly