Autoimmune hepatitis

Question 1

Define autoimmune hepatitis

Answer 1

Chronic hepatitis of unknown aetiology, characterised by autoimmune features, hyperglobulinaemia & the presences of circulating autoantibodies

Question 2

Aetiology of autoimmune hepatitis

3

Answer 2

In genetically predisposed individuals, an environmental agent (e.g. virus or drug) may lead to hepatocyte expression of HLA antigens, which then become the focus of a principally T cell mediated autoimmune attack

Raised titre of anti nuclear antibodies (ANA), anti smooth muscle antibodies (ASMA) & anti liver/kidney microsomes (anti LKM) are NOT thought to directly injure liver

Chronic inflammatory changes are similar to those seen in chronic viral hepatitis w/ lymphoid infiltration of the portal tracts & hepatocyte necrosis leading to fibrosis & eventually cirrhosis

Question 3

Types of autoimmune hepatitis & differences

4+2

Answer 3

Type 1 (classic)
ANA
ASMA
Anti actin antibodies (AAA)
Anti soluble liver antigen (anti SLA)

Type 2
Antibodies to liver/kidney microsomes (ALKM-1)
Antibodies to liver cytosol antigen (ALC-1)

Question 4

Epidemiology of autoimmune hepatitis

2 populations

Answer 4

Type 1 occurs in ALL age groups but mainly young women

Type 2 generally occurs in girls & young women

Question 5

Presenting symptoms of autoimmune hepatitis

3

Answer 5

May be ASYMPTOMATIC & discovered through abnormal LFT
Insidious presentation
Acute hepatitis (25%)

Question 6

Presenting symptoms of autoimmune hepatitis - insidious presentation
(8)

Answer 6

Malaise
Fatigue
Anorexia
Weight loss
Nausea
Jaundice
Amenorrhoea
Epistaxis

Question 7

Presenting symptoms of autoimmune hepatitis - acute hepatitis
(6)

Answer 7

Fever
Anorexia
Jaundice 
N&V&D
RUQ pain
Some present w/ serum sickness (e.g. arthralgia, polyarthritis, maculopapular rash)

Question 8

Signs of autoimmune hepatitis on physical examination

3

Answer 8

Stigmata of chronic liver disease (e.g. spider naevi)
Ascites, oedema & hepatic encephalopathy are late features
Cushingoid features may be present even before the administration of steroids

Question 9

Investigations for autoimmune hepatitis

5

Answer 9

Bloods
Liver biopsy
To rule out other causes of liver disease
US/CT/MRI of liver & abdomen
ERCP

Question 10

Investigations for autoimmune hepatitis - bloods

4

Answer 10

LFTs
high AST, ALT, GGT, ALP & bilirubin
low albumin (in severe disease)

Clotting
high PT (in severe disease)

FBC
low Hb, platelets & WCC (if hypersplenism from portal hypertension)

Hypergammaglobulinaemia
presence of ANA, ASMA, & anti LKM antibodies

Question 11

Investigations for autoimmune hepatitis - liver biopsy

Answer 11

Needed to establish diagnosis & check whether hepatitis or cirrhosis

Question 12

Investigations for autoimmune hepatitis - to rule out other causes
(5)

Answer 12

Viral serology
Urinary copper/caeruloplasmin
Ferritin & transferring saturation
α1 antitrypsin 
Anti mitochondrial antibodies (PBC)

Question 13

Investigations for autoimmune hepatitis - US/CT/MRI

Answer 13

Visualise structural lesions

Question 14

Investigations for autoimmune hepatitis - ERCP

Answer 14

To rule out PSC