Jaundice

Question 1

What type of jaundice is seen classically with the following bloods:

Hb 153, Plts 75, WCC 6.4, ALT 90, Alk Phos 132, Bili 40, PT 24

Answer 1

Hepatocellular

A raised ALT, an Alk Phos within the upper limits of normal, with low platelets and high INR, this is most likely to be hepatocellular in nature (most commonly alcoholic liver disease)

Question 2

A patient is admitted with RUQ pain and blood tests showing a post-hepatic jaundice, the patient otherwise well and stable. What is the most appropriate initial investigation?

Answer 2

US abdomen

Question 3

What are the bilirubin levels for the jaundice to occur?

Answer 3

Bilirubin levels >50µmol/L

Question 4

What is the jaundice result of?

Answer 4

High level of bilirubin in the blood

Question 5

Bilirubin pathway

Answer 5

• Bilirubin is the normal breakdown product from the catabolism of haem (destruction of RBCs)
• bilirubin undergoes conjugation within the liver, making it water-soluble
• It is then excreted via the bile into the GI tract, the majority of which egested in the faeces as urobilinogen
• Around 10% is reabsorbed into the bloodstream and excreted through the kidneys

Jaundice occurs when this pathway is disrupted.

Question 6

Pre-hepatic jaundice

• what happens in overall?
• what happens to bilirubin?

Answer 6

Pre-hepatic jaundice

• Happens as a result of excessive breakdown of RBCs
• the liver cannot cope with excess bilirubin -> cannot conjugate it all -> unconjugated bilirubin
• unconjugated bilirubin = jaundice

*some bilirubin can manage to be conjugated and to be excreted normally. It’s only an unconjugated bilirubin that remains in the bloodstream and appear as a jaundice

Question 7

Hepatocellular jaundice

• what happens?
• what picture of jaundice can be seen and why?

Answer 7

Hepatocellular/ intracellular

• liver loses its ability to conjugate bilirubin (due to liver damage/ impairment)
• mixed picture jaundice may occur because, example:
• liver cirrhosis may compress on the hepetic portion of biliary duct -> conjugated bilirubin
• liver damage -> cannot conjugate -> unconjugated bilirubin

Question 8

Post-hepatic jaundice

• what happens
• type of jaundice

Answer 8

Post-hepatic

• bilirubin cannot be excreted from a biliary tract due to obstruction
• as bilirubin was conjugated by the liver -> conjugated hyperbilirubinaemia

Question 9

Pre- hepatic causes of jaundice

Name some specific conditions

Answer 9

• *Pre-Hepatic**
• Haemolytic anaemia
• Gilbert’s syndrome or Criggler-Najjar syndrome

Question 10

Hepatocellular jaundice causes

(specific conditions)

Answer 10

Hepatocellular jaundice

• Alcoholic liver disease
• Viral hepatitis
• Medication
• Hereditary haemochromatosis
• Autoimmune hepatitis
• Primary biliary cirrhosis
• Primary sclerosing cholangitis
• Hepatocellular carcinoma

Question 11

Post-hepatic jaundice causes

• specific conditions

Answer 11

Post-hepatic jaundice

• Intra-luminal causes, such as gallstones
• Mural causes, such as cholangiocarcinoma, strictures, or drug-induced cholestasis
• Extra-mural causes, such as pancreatic cancer or abdominal masses (e.g. lymphomas)

Question 12

Colour of urine and type of jaundice

Answer 12

Conjugated bilirubin (as per normal pathway) may be excreted in the urine

• dark, coca-cola urine -> in conjugated, mixed-type jaundice
• normal urine -> in unconjugated

Question 13

Investigations for jaundice (bloods) + rationale

Answer 13

FBC -> anaemia, raised MCV, thrombocytopaenia - seen in all liver diseases

LFTs-> to look for a degree of jaundice, hepatocellular injury

U&Es

Coagulation studies -> PT may be raised in liver dysfunction (due to impaired synthesis of clotting factors)

Question 14

LFTs in testing for jaundice

(explain each component of the blood test)

Answer 14

• Bilirubin -> to assess the degree of jaundice
• Albumin -> marker of liver synthesis function
• AST and ALT -> marker of hepatocellular injury
• Alkaline Phosphatase -> raised in a biliary obstruction (or in bone injury)
• Gamma-GT -> raised in biliary obstruction

*Gamma-GT is not a part of standard LFTs - requested separately if ALP is raised

Question 15

What conditions are the ratios suggesting of:

• AST:ALT ratio of >2
• AST:ALT ratio of around 1

Answer 15

• AST:ALT ratio of >2 -> likely alcohol liver disease
• AST:ALT ratio of around 1 -> likely viral hepatitis

Question 16

When to perform liver screen?

What are the main two categories looked at in the liver screen?

Answer 16

If unsure of what is causing a liver dysfunction

Categories:

A. Acute Liver Injury

B. Chronic liver injury

*both looking at viral serology and non-infective markers

Question 17

Components of the liver screen in acute liver injury

• viral serology
• non- infective markers

Answer 17

Question 18

Components of the liver screen in chronic liver injury:

• viral serology
• non-infective markers

Answer 18

Question 19

Autoantibodies screened for in the liver screen for chronic liver injury

Answer 19

Chronic liver injury, non-infective causes markers - autoantibodies:

• AMA anti-mitochondrial antibody
• Anti-SMA anti-smooth muscle antibody
• ANA anti-nuclear antibody

*these are used to identify variety of autoimmune conditions e.g. primary sclerosing cholangitis

Question 20

Imaging in the investigation of jaundice

Answer 20

• abdominal USS -> to identify obstructive causes or gross liver pathology

• MRCP -> to visualise biliary tree*

*MRCP is typically performed if obstructive jaundice is suspected, but USS abdomen was inconclusive

Question 21

Examples for definitive treatment for jaundice

Answer 21

Depends on underlying cause, e.g.

obstructive - removal of gallstone through ERCP, open surgery, cholecystectomy, stenting of the common bile dugt

Question 22

Symptomatic treatment of itching in obstructive jaundice

Answer 22

Itching (due to hyperbilirubinaemia)

• cholestyramine - to improve biliary drainage

*MoA of cholestyramine: it is a bile acid sequestrant; combines with bile acids in the intestine -> forms an insoluble complex that is excreted in the faeces

• antihistamines

Question 23

Possible complications of liver failure (monitoring and management)

Answer 23

Coagulopathy/ bleeding -> vitamin K, Fresh Frozen Plasma (FFP)

Hypoglecaemia -> oral Rx (when possible) or 5% dexterose

Confusion (from hepatic encephalopathy):

• • laxatives (lactulose or senna)*
• • neomycin or rifaximin (*to reduce the number of ammonia-producing bacteria in the bowel)

* neomycin - aminoglycoside antibiotic

* rifaximin - semi-synthetic antibiotics (used in travellers diarrhoea and hepatic encephalopathy)

Question 24

Gilbert’s syndrome

1. What is this
2. Pathology and genetics

Answer 24

Gilbert’s syndrome

1. It is a mild liver disorder - unable to fully process bilirubin
2. Mutation in UGT1A1 gene -> decreased function of bilirubin uridine diphosphate glucuronosyntransferate enzyme
   - usually inherited in AR pattern
   - rarely inherited in AD pattern - depends on type of mutation

Question 25

***Gilbert syndrome*** 1. Symptoms and presentation 2. Diagnosis

Answer 25

***Gilbert syndrome*** ## Footnote 1. **Symptoms** - occasional yellowing of the skin or sclera - weakness/ fatigue - abdominal pain \* episodes of jaundice may be triggered by stress, exercise, menstruation, starvation 2. **Diagnosis**: higher levels of unconjugated bilirubin in the blood without signs or liver problems or RBCs breakdown

Question 26

***Gilbert syndrome*** Treatment

Answer 26

***Gilbert syndrome*** - usually, no treatment is needed - significant jaundice -\> ***phenobarbital*** \*phenobarbital is barbiturate; in jaundice, it works by increasing liver metabolism (so it will conjugate more bilirubin)

Question 27

***Crigler - Najjar syndrome*** 1. What is this and complications 2. Pathology and genetics

Answer 27

***Crigler-Najjar syndrome*** - disorder of bilirubin metabolism - manifests in infancy - for od non-haemolytic jaundice - accumulation of bilirubin -\> brain damage in infants _Genetics:_ **AR** manner of inheritance **Pathology:** *uridine* *diphosphogluconurate* *glucuronosyltransferase* (UGT1A1) enzyme dysfunction -\> bilirubin cannot be conjugated

Question 28

**Crigler-Najjar syndrome** What's seen and what's not seen on the investigation

Answer 28

***Crigler-Najjar*** - **liver function and hepatic histology** -\> are usually normal = no evidence of liver damage - no evidence of haemolysis

Question 29

Treatment in Crigler- Najjar syndrome

Answer 29

- plasmapheresis - phototherapy - liver transplant - curative

Question 30

***Dubin - Johnson syndrome*** - pathology and genetics

Answer 30

**AR** benign disorder -\> increased conjugated bilirubin in the serum Pathology: hepatocytes unable to secrete conjugated bilirubin into the bile (instead it goes into the serum/blood)

Question 31

***Dubin - Johnson syndrome*** - the appearance of the liver

Answer 31

***Dubin-Johnson*** - liver would be black or pink - due to the accumulation of pigment

Question 32

***Dubin - Johnson syndrome*** ## Footnote - diagnosis

Answer 32

Unusual ratio between the byproducts of heme biosynthesis: * normally, **[coproporphyrin](https://en.wikipedia.org/wiki/Coproporphyrin) III to coproporphyrin I ratio** around 3–4:1. * in Dubin–Johnson syndrome, this ratio is inverted, with coproporphyrin I being 3–4 times higher than coproporphyrin III For the first two days of life, healthy neonates have ratios of **urinary coproporphyrin** similar to those seen in patients with Dubin–Johnson syndrome; by 10 days of life, however, these levels convert to the normal adult ratio

Question 33

**Dubin-Johnson syndrome** treatment

Answer 33

The condition is benign and usually, no treatment is needed as most patients are asymptomatic \*it is important to recognise it so it is not confused with other disorders associated with hyperbilirubinaemia (jaundice)