Autoimmune Hepatitis

Question 1

Define Autoimmune Hepatitis:

Answer 1

Chronic Hepatitis of unknown aetiology

Characterised by autoimmune features, suppressor T-cell defects with autoantibodies directed against hepatocyte surface antigens and hyperglobulinaemia

Question 2

What are the two types of Autoimmune Hepatitis?

Answer 2

Type 1:

• ANA (Anti-nuclear)
• ASMA (Anti-smooth muscle)
• AAA (Anti-actin)
• anti-SLA (smooth liver antigen)

Type 2:

• ALKM-1 (Liver/kidney microsomes)
• ALC-1 (Liver cytosol)

Question 3

Describe the epidemiology of the different types of Autoimmune Hepatitis:

Answer 3

4:1 - female:male

Type 1 - 80% - mainly young women

Type 2 - generally girls and young women

Question 4

What are the risk factors for Autoimmune Hepatitis?

Answer 4

Personal or FHx of autoimmune disease

AI Hepatitis is often seen alongside Hashimoto’s thyroiditis or Graves’ disease

Question 5

Outline the pathophysiology of Autoimmune Hepatitis:

Answer 5

Genetical predisposition + Environmental trigger (e.g. virus/drugs)

Leads to Hepatocyte expression of HLA [MHC II] (often HLA-DR3/DR4)

These become focus of T-cell-mediated autoimmune attack

Lead to: Chronic inflammatory changes w/lymphoid infiltration of portal tracts + hepatocyte necrosis

(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)

Question 6

Describe how Autoimmune Hepatitis can progress:

Answer 6

Highly variable - may always remain asymptomatic

Hepatocyte necrosis due to AI attack can lead to Fibrosis and eventually Cirrhosis

Question 7

In what 3 ways may Autoimmune Hepatitis present?

Answer 7

Asymptomatic - accidental discovery through abnormal LFTs

Acute hepatitis (40%)

Insidious Onset

Question 8

How would acute Autoimmune Hepatitis present?

Answer 8

• Fever
• Malaiese
• Anorexia
• Jaundice
• Nausea & Vomitting
• RUQ pain
• Urticarial rash

+/- Serum sickness (polyarthritis, arthralgia, maculopapular rash)

Question 9

How might an insidious onset Autoimmune Hepatitis present?

Answer 9

• Malaise
• Fatigue
• Anorexia
• Cachexia
• Nausea
• Jaundice
• Amenorrhea
• Epistaxis

Question 10

What signs might you see on examination of someone with Autoimmune Hepatitis?

Answer 10

Stigmata of chronic liver disease

Ascites, oedema and hepatic encephalopathy in late-stage

Cushingoid features

Question 11

What might blood results for a patient with Autoimmune Hepatitis look like?

Answer 11

FBC:
Low Hb, PLT and WCC (if hypersplenism from portal HTN)

LFTs:
High ALT, AST (ALT typically higher)
High GGT, ALP
High Bilirubin
Low albumin in severe disease

Clotting:
High PT in severe

Hypergammaglobulinaemia:
+ve ANA, ASMA, Anti-LKM

Question 12

Apart from bloods, what other investigations may you perform if you suspect Autoimmune Hepatitis?

Answer 12

Liver biopsy: establish diagnosis and check for stage (hepatitis or cirrhosis)

US, CT, MRI: to visualise structural lesions

ERCP: to rule out PSC

Question 13

What 6 tests may you do in establishing whether Autoimmune Hepatitis is the cause of liver disease?

Answer 13

• Viral serology
• Urinary copper/ceruloplasmin
• Ferritin and transferrin saturation
• alpha₁ antitrypsin
• Anti-mitochondrial antibodies (PBC)
• ERCP to exclude PSC

Question 14

(not a LO)

How might you treat Alcoholic Hepatitis?

Answer 14

Corticosteroids - pred

Azathioprine

Liver transplant