Autoimmune Hepatitis

Question 1

What is autoimmune hepatitis?

Answer 1

chronic inflammatory disease of the liver of unknown aetiology, characterised by autoimmune features, hyperglobulinaemia and the presence of circulating autoantibodies

Question 2

What are the 3 types of autoimmune hepatitis a patient can have?

Answer 2

1. Type 1 AIH (Most Common - 80%) → antinuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA). Children and adults.
2. Type 2 AIH → anti-liver-kidney microsomal-1 antibodies (anti-LKM-1). Affects children only.
3. Type 3 AIH → anti-soluble liver antigen

Question 3

What causes autoimmune hepatitis?

Answer 3

UNKNOWN
- In a genetically predisposed individual, an environmental agent (e.g. viruses or drugs) may lead to hepatocyte expression of HLA antigens, which then become the focus of a principally T-cell-mediated autoimmune attack
- The raised titre of anti-nuclear antibodies (ANA), anti-smooth muscle antibodies (ASMA) and anti-liver/kidney microsomes (anti-LKM) are NOT thought to directly injure the liver
- The chronic inflammatory changes are similar to those seen in chronic viral hepatitis with lymphoid infiltration of the portal tracts and hepatocyte necrosis, leading to fibrosis and, eventually, cirrhosis

Question 4

Summarise the epidemiology of autoimmune hepatitis

Answer 4

Type 1: occurs in ALL age groups (but mainly young women)
Type 2: generally occurs in girls and young women

Question 5

What are the presenting symptoms of hepatitis?

Answer 5

1. May be asymptomatic and discovered incidentally through abnormal LFT
2. Insidiously present with:
   - Malaise
   - Fatigue
   - Anorexia
   - Weight loss
   - Nausea
   - Jaundice
   - Amenorrhoea
   - Epistaxis
3. Acute hepatitis (25%) presents with:
   - Fever
   - Anorexia
   - Jaundice
   - Nausea/Vomiting/Diarrhoea
   - RUQ pain
   - Some may present with serum sickness (e.g. arthralgia, polyarthritis, maculopapular rash)
4. NOTE: check for personal or family history of other autoimmune diseases
5. A full history is important to rule out other causes of hepatitis (e.g. viral, alcoholic)

Question 6

What signs of autoimmune hepatitis can be found on physical examination

Answer 6

• Stigmata of chronic liver disease (e.g. spider naevi)
• Ascites, oedema and hepatic encephalopathy are late features
• Cushingoid features (rounded face, acne, hirsuitism, cutaneous striae) may be present even before the administration of steroids

Question 7

What investigations are used to diagnose/ monitor autoimmune hepatitis?

Answer 7

1. Increased ALT & AST
2. Serum Antibodies
   - Type 1 → ANA & ASMA
   - Type 2 → anti-LKM-1
3. Serum Protein Electrophoresis → hypergammaglobulinemia (↑IgG)
4. Liver Biopsy → confirms diagnosis. Inflammation & bridging necrosis seen.
5. Prolonged PT, Increased Bilirubin, Decreased Albumin

Question 8

How is autoimmune hepatitis managed?

Answer 8

1. Corticosteroids → prednisolone
2. Immunosuppressants → azathioprine
3. Liver Transplantation

Question 9

What complications may arise from autoimmune hepatitis?

Answer 9

• Fulminant hepatic failure – severe impairment of hepatic functions in the absence of pre-existing liver disease
• Cirrhosis
• Complications of portal hypertension – varices, ascites
• Hepatocellular carcinoma
• Side-effects of corticosteroid treatment

Question 10

Summarise the prognosis for patients with autoimmune hepatitis

Answer 10

• Older patients more likely to have cirrhosis at presentation but may be more likely to respond to treatment
• 80% achieve remission by 3 years
• 35-50% remain in remission when immunosuppression withdrawn
• 50% require lifelong maintenance
• 5 year survival rate: 85% if treated, 50% if untreated
• 5 year survival rate after transplant > 80%