FN: Jaundice

Question 1

Hb metabolism

Answer 1

1. Hb converted to unconjugate Bilirubin by splenic macrophages
2. uBR is conjugated by bilirubin UDP glucoronyl transferase in the liver
3. cBR is then secreted in bile and converted to urobilinogen (colourless)

Question 2

Urobilinogen metabolism

Answer 2

1. Some urobilinogen is reabsorbed, returned to liver and excreted into bile
2. Some reabsorbed urobilinogen is excreted into the urine
3. The urobilinogen that remaines in the GIT is concerted to stercobilin (brown) and excreted

Question 3

Pre-Hepatic causes if Jaundice

Answer 3

Excess BR production
􏰀 - Haemolytic anaemia
􏰀- Ineffective erythropoiesis
􏰁 e.g. thalassaemia

Question 4

Hepatic causes of Jaundice unconjugated

Answer 4

1. ↓ BR Uptake
􏰀 Drugs: contrast, RMP 􏰀 CCF
2. ↓ BR Conjugation
􏰀 Hypothyroidism
􏰀 Gilbert’s (AD)
􏰀 Crigler-Najjar (AR)
3. Neonatal jaundice is both ↑ production + ↓ conjug.

Question 5

Hepatic causes of Jaundice conjugated

Answer 5

Hepatocellular Dysfunction
􏰀 1. Congen: HH, Wilson’s, α1ATD
2. 􏰀 Infection: Hep A/B/C, CMV, EBV
3. 􏰀 Toxin: EtOH, drugs
4. 􏰀 AI: AIH
5. 􏰀 Neoplasia: HCC, mets
6. 􏰀 Vasc: Budd-Chiari

↓ Hepatic BR Excretion
􏰀 - Dubin-Johnson
􏰀 - Rotor’s

Question 6

Post-Hepatic causes of Jaundice

Answer 6

Obstruction
􏰀 Stones
􏰀

Question 7

Drug-induced Haundice and mechanism of causing jaundice

Answer 7

1. Antimalarials (e.g. dapsone)
2. Hepatitis caused by
   - paracetamol OD
   - RMP, INH, PZA
   - Valproate
   - Statins
   - Halothane
   - MAOIs
3. Cholestatsis
   - Fluclox (may be weeks after Treatment)
   - Co-amoxiclav
   - OCP
   - Sulfonylureas
   - chlopromazine, prochlorperazine

Question 8

Gilberts syndrome

Answer 8

􏰀 Auto dom partial UDP-GT deficiency
􏰀 2% of the population
􏰀 Jaundice occurs during intercurrent illness 􏰀

Dx: ↑ uBR on fasting, normal LFTs

Question 9

Crigler-Najjar

Answer 9

• Rare auto rec total UDP-GT deficiency
• Severe neonatal jaundice and kernicterus
• Rx: liver Tx

Question 10

Pre-hepatic Jaundice urine results

Answer 10

• No BR (acholuric)
• increased urobilinogen
• increased Hb if intravascular haemolysis

Question 11

Pre-hepatic Jaundice LFTs show

Answer 11

• increased uBR
• Increased AST
• Increased LDH

Question 12

Pre-hepatic jaundice other investigations

Answer 12

• FBC and film
• Coombs test
• Hb electrophoresis

Question 13

Hepatic Jaundice Urine shows

Answer 13

Increased BR

- increased urobilinogen

Question 14

Hepatic Jaundice LFTs shows

Answer 14

􏰀 ↑ cBR (usually)
􏰀 ↑AST:↑ALT
􏰁 >2=EtOH
􏰁 <1=Viral
􏰀 ↑ GGT (EtOH, obstruction)
􏰀 ↑ALP
􏰀 Function: ↓ albumin, ↑ PT

Question 15

Hepatic Jaundice Other investigations

Answer 15

􏰀 - FBC: anaemia
- 􏰀 Anti- SMA, LKM, SLA, ANA
􏰀 - α1AT, ferritin, caeruloplasmin
- 􏰀 Liver biopsy

Question 16

Post-Hepatic Jaundice Urine results

Answer 16

very high Bilirubin

No urobilinogen

Question 17

Post-Hepatic Jaundice LFTs show

Answer 17

􏰀 ↑↑cBR
􏰀 ↑AST,↑ALT 􏰀 ↑↑ALP
􏰀 ↑GGT

Question 18

Post-Hepatic Jaundice other investigations

Answer 18

􏰀 Abdo US: ducts >6mm
􏰀 ERCP, MRCP
􏰀 Anti- AMA, ANCA, ANA