Diagnosis of Autoimmune Hepatitis

How do doctors diagnose autoimmune hepatitis?

Doctors diagnose autoimmune hepatitis based on your medical history, a physical exam, and tests.

Medical history

Your doctor will ask about your symptoms and other factors that could be damaging your liver. For example, your doctor may ask about any medicines and herbal or botanical products you take and how much alcohol you drink. Your doctor will ask you about other autoimmune diseases that you might have, such as inflammatory bowel disease or thyroid conditions.

Physical exam

During a physical exam, your doctor will check for signs of liver damage such as

• yellowish color of the whites of the eyes
• changes in the skin
• enlargement of the liver or spleen
• tenderness or swelling in the abdomen
• swelling in the lower legs, feet, or ankles, called edema

What tests do doctors use to diagnose autoimmune hepatitis?

Your doctor may order blood tests, imaging tests, and a liver biopsy to diagnose autoimmune hepatitis.

Blood tests

Your doctor may order one or more blood tests to help diagnose autoimmune hepatitis. A health care professional will take a blood sample from you and send the sample to a lab. Your doctor will use blood tests to look for evidence of autoimmune hepatitis.

Blood tests include tests that check levels of the liver enzymes alanine transaminase (ALT) and aspartate transaminase (AST) and check for autoantibodies such as antinuclear antibody (ANA) and anti-smooth muscle antibody (SMA). ALT and AST are particularly important because these liver enzymes are highly elevated in people with autoimmune hepatitis. Doctors check ALT and AST levels to follow the progress of the disease and the response to treatment.

Doctors will order additional blood tests to look for other liver diseases that have symptoms similar to autoimmune hepatitis, such as viral hepatitis, primary biliary cholangitis, primary sclerosing cholangitis, nonalcoholic steatohepatitis (NASH), or Wilson disease.

Imaging Tests

Your doctor may order imaging tests of your abdomen and liver. The most commonly used test is ultrasound. Ultrasound uses a device called a transducer, which bounces safe, painless sound waves off organs to create images of their structure. An ultrasound can show whether the liver is enlarged, has an abnormal shape or texture, or has blocked bile ducts.

Doctors sometimes order a computed tomography (CT) scan, which uses a combination of x-rays and computer technology to create images. A CT scan can show the size and shape of the liver and spleen and whether there is evidence of cirrhosis. Doctors may also order magnetic resonance imaging (MRI), which uses radio waves and magnets to produce detailed images of organs and soft tissues without using x-rays. MRI can show the shape and size of the liver and detect evidence of cirrhosis.

Liver biopsy

During a liver biopsy, a doctor will take a piece of tissue from your liver. A pathologist will examine the tissue under a microscope to look for the amount of injury and features of specific liver diseases. A doctor can use a liver biopsy to look for the features of autoimmune hepatitis and to check the amount of scarring to find out if you have cirrhosis.