Gastroenterology

Question 1

Causes of chronic liver disease

Answer 1

Cholestatic

• Extrahepatic biliary atresia **MOST common cause**
• Alagile syndrome
• Progressive familial intrahepatic cholestasis

Metabolic (WATCH)

• Wilson disease
• Alpha 1 antitrypsin (AAT) deficiency
• Tyrosinaemia type 1
• Cystic fibrosis
• Hereditary fructose intolerance

Chronic hepatitis

• Autoimmune (primary sclerosing cholangitis, autoimmune hepatitis)
  
  • Most respond to prednisolone or azathioprine or cyclosporine or tacrolimus
• Infection: B/C

Acute liver failure

• Drugs: paracetamol
• Infections: hepatitis A/B/C, EBV, HSV, parvovirus
• Hypoperfusion

Oncological

Vascular

Question 2

Extrahepatic bilary atresia

Answer 2

• MOST common cause of liver failure in children
• 10-15% associated with other anomalies: cardiac defects, polysplenia, inferior vena cava anomalies, situs inversus, malrotation
• Destruction of extrahepatic + intrahepatic ducts –> cholestasis –> fibrosis –> cirrhosis
• Treatment: Kasai portoenterostomy (palliative procedure) = removal of fibrosed biliary tree + forming a Roux-en-Y anastomosis
• Only usually successful if performed < 60 days of life
• Recurrent cholangitis, cirrhosis + portal hypertension inevitably occur therefore need a liver transplant

Question 3

Alagille syndrome

Answer 3

• Autosomal dominant
• Multisystem disorder
  
  • Intrahepatic biliary hypoplasia
    
    • 50% regain normal liver function by adolescence
    • Treatment:
      
      • Uursodeoxycholic acid (increases volume of bile)
      • Cholestyramine (bile acid sequestration)
      • Rifampicin (decreases itch)
      • Naltrexone (opiate antogonist, decreases itch)
  • Facial dysmorphism
    
    • Wide forehead, deep set eyes, long straight nose, prominent chin (triangular), low set ears
  • Cardiac defects
    
    • Peripheral pulmonary artery stenosis, right sided heart defects, septal defects
  • Renal abnormalities
    
    • Structural + parenchymal issues
  • Skeletal abnormalities
    
    • Butterfly vertebrae
  • Ocular anomalies
    
    • Posterior embryotoxin
  • Poor growth
  • Delayed milestones + puberty

Question 4

Alpha 1 antitrypsin deficiency

Answer 4

• Autosomal co-dominant
• Liver disease only occurs in Z, M or S phenotypes
• Diagnosis
  
  • Low serum AAT levels
• Management
  
  • No specific therapy for AAT deficiency CLD exists
  • AAT replacement therapy is only for the emphysema of AAT deficiency
• Prognosis
  
  • 1/3 patients will require a transplant
  • 1/3 recover
  • 1/3 cirrhosis