Autoimmune hepatitis is a chronic inflammatory liver disease which, untreated, often leads to cirrhosis.
Presentation
- 25% asymptomatic at diagnosis
- Others:
- fatigue
- pruritis
- anorexia
- nausea
- abdominal pain
- joint pain
Associations
- long-term use of some medications, such as nitrofurantoin or minocycline
- primary biliary cirrhosis - up to 15%
- primary sclerosing cholangitis - up to 8%
- thyroiditis - up to 23%
- diabetes - up to 9%
Investigations
- LFTs - raised AST/ALT
- autoantibodies
- ANA
- SMA
- SLA/LP (soluble liver antigen/liver-pancreas)
- LKM (liver-kidney microsome)
- dsDNA - 15% (specific for either AIH or SLE)
- raised IgG
- negative tests for viral hepatitis
- liver biopsy may show
- lots of plasma cells - 'plasma-cell hepatitis'
- inflammation of hepatocytes at the junction of portal tract and hepatic parenchyma - 'piecemeal necrosis'
Types of AIH:
- Type 1
- 75% of AIH
- ANA/SMA/anti SLA/LP
- all ages
- F:M 3:1
- Type 2
- anti-LKM-1 or anti LC-1
- usually presents in childhood
- F:M 10:1
- more likely to not respond to treatment
Treatment
- corticosteroids
- azathioprine
- lifelong in type 2 AIH; can consider stopping after remission of at least 4 years in type 1 AIH
- 10-20% of patients will need liver transplants.
Small print gems: In terms of liver diseases, raised IgG suggests AIH, IgM suggests PBC and IgA suggests steatohepatitis (alcoholic or non-alcoholic)