autoimmune hepatitis

Question 1

definition

Answer 1

Autoimmune hepatitis (AIH) is a chronic inflammatory disease of the liver of unknown aetiology.

More frequently affects women and has a variable course with different clinical manifestations, ranging from no symptoms to fulminant hepatic failure.

Concurrent autoimmune diseases are often present.

Aminotransferase levels are usually more strikingly raised than bilirubin and gamma-GT levels.

Characterised by the presence of circulating auto-antibodies (antinuclear antibody, smooth muscle antibody, perinuclear anti-neutrophil cytoplasmic auto-antibody, anti-soluble liver antigen/liver pancreas, anti-liver kidney microsomal-1, anti-liver cytosol) with a high serum globulin concentration and inflammatory changes on liver histology.

Treatment options include corticosteroids alone or in combination with other immunosuppressants.

Liver transplantation is indicated in patients with advanced liver disease who are refractory or intolerant to corticosteroid therapy.

Question 2

symptoms

Answer 2

May be asymptomatic and discovered incidentally by abnormal LFT.

Insidious onset: Malaise, fatigue, anorexia, weight loss, nausea, jaundice, amenorrhoea, epistaxis (nose bleeds).

Acute hepatitis (25%): Fever, anorexia, jaundice, nausea, vomiting, diarrhoea, RUQ pain.
Some may also present with serum sickness (e.g. arthralgia, polyarthritis, maculopapular rash).
May be associated with keratoconjuctivitis sicca.

Question 3

epidemiology

Answer 3

Type 1 autoimmune hepatitis occurs in all age groups (although mainly in young women). Type 2 is generally a disease of girls and young women.

Type I (classic): ANA, anti-smooth muscle antibodies (ASMA), anti-actin antibodies (AAA), anti-soluble liver antigen (anti-SLA).
Type 2: Antibodies to liver/kidney microsomes (ALKM-1, directed at an epitope of CYP2D6), antibodies to a liver cytosol antigen (ALC-1).

Question 4

risk factors

Answer 4

Personal or family history of autoimmune disease, e.g. type 1 diabetes mellitus and vitiligo.
It is important to take a full history to rule out other potential causes of liver disease (e.g. alcohol, drugs).

Question 5

signs

Answer 5

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

Question 6

investigations

Answer 6

1st investigations:

• AST
• ALT
• bilirubin
• GGT
• ALP
• serum globulin
• serum albumin
• prothrombin time

others to consider:
- ANA, anti-ssDNA etc.