Diagnosis of Autoimmune Hepatitis

Your doctor will make a diagnosis based on your symptoms, blood tests, and liver biopsy.

• Blood tests. A routine blood test for liver enzymes can help reveal a pattern typical of hepatitis, but further tests, especially for autoantibodies, are needed to diagnose autoimmune hepatitis. Antibodies are proteins made by the immune system to fight off bacteria and viruses. In autoimmune hepatitis, the immune system makes antinuclear antibodies (ANA), antibodies against smooth muscle cells (SMA), or liver and kidney microsomes (anti-LKM). The pattern and level of these antibodies help define the type of autoimmune hepatitis (type I or type II).
  
  Blood tests also help distinguish autoimmune hepatitis from viral hepatitis (such as hepatitis B or C) or a metabolic disease (such as Wilson's disease).
  
  
• Liver biopsy. A tiny sample of your liver tissue, examined under a microscope, can help your doctor accurately diagnose autoimmune hepatitis and tell how serious it is. You will go to a hospital or outpatient surgical facility for this procedure.

source: http://digestive.niddk.nih.gov/ddiseases/pubs/autoimmunehep/index.htm