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|Classification and external resources|
|Classification and external resources|
Autoimmune Hepatitis is a disease of the liver that occurs when the body's immune system attacks cells of the liver. Anomalous presentation of human leukocyte antigen (HLA) class II on the surface of hepatocytes, possibly due to genetic predisposition or acute liver infection, causes a cell-mediated immune response against the body's own liver, resulting in autoimmune hepatitis. This abnormal immune response results in inflammation of the liver, which can lead to further symptoms and complications such as fatigue and cirrhosis.
Four subtypes are recognised, but the clinical utility of distinguishing subtypes is limited.
The patient is classically a young female. They may present with signs of chronic liver disease (cirrhosis, low albumin, spider naevi etc.) or acute hepatitis (25% present with fever, jaundice, painful hepatomegaly etc.). Commonly, the patient will have amenorrhoea - this may be the presenting complaint.
"Autoimmune hepatitis usually occurs in women (70 %) between the ages of 15 and 40. Although the term "lupoid" hepatitis was originally used to describe this disease, patients with systemic lupus erythematosus do not have an increased incidence of autoimmune hepatitis and the two diseases are distinct entities. Patients usually present with evidence of moderate to severe hepatitis with elevated serum ALT and AST activities in the setting of normal to marginally elevated alkaline phosphatase and gamma-glutamyltranspeptidase activities. The patient will sometimes present with jaundice, fever and right upper quadrant pain and occasionally systemic symptoms such as arthralgias, myalgias, polyserositis and thrombocytopenia. Some patients will present with mild liver dysfunction and have only laboratory abnormalities as their initial presentation. Others will present with severe hepatic dysfunction."
60% of patients have chronic hepatitis that may mimic viral hepatitis, but without serologic evidence of a viral infection. The disease usually affects women and is strongly associated with anti-smooth muscle auto-antibodies.
|This section requires expansion. (January 2011)|
A number of specific antibodies found in the blood (antinuclear antibody (ANA), anti-smooth muscle antibody (SMA), liver/kidney microsomal antibody (LKM-1, LKM-2, LKM-3), anti soluble liver antigen (SLA/LP) and anti-mitochondrial antibody (AMA)) are of use, as is finding an increased Immunoglobulin G level. However, the diagnosis of autoimmune hepatitis always requires a liver biopsy.
Expert opinion has been summarized by the International Autoimmune Hepatitis Group, which has published criteria which utilize clinical and laboratory data that can be used to help determine if a patient has autoimmune hepatitis. A calculator based on those criteria is available online.
Treatment may involve the prescription of immunosuppressive glucocorticoids, with or without azathioprine, and remission can be achieved in up to 60–80% of cases, although many will eventually experience a relapse. Budesonide has been shown to be more effective in inducing remission than prednisone, and result in fewer adverse effects. Patients who do not respond to glucocorticoids and azathioprine may be given other immunosuppressives like mycophenolate, cyclosporin, tacrolimus, methotrexate etc. Liver transplantation may be required if patients do not respond to drug therapy or when patients present with fulminant liver failure.
Autoimmune hepatitis has an incidence of 1-2 per 100,000 per year, and a prevalence of 10-20/100,000. As with most other autoimmune diseases, it affects women much more often than men (70%). Liver enzymes are elevated, as may be bilirubin.
Autoimmune hepatitis was previously called "lupoid" hepatitis. It was originally described in the early 1950s.
Most patients do have an associated autoimmune disorder such as systemic lupus erythematosus. Thus, its name was previously lupoid hepatitis.
Because the disease has multiple different forms, and is not always associated with systemic lupus erythematosus, lupoid hepatitis is no longer used. The current name at present is autoimmune hepatitis (AIH).