Autoimmune Hepatitis

Autoimmune hepatitis is a chronic liver disease that begins with a mistake of your immune system. Your immune system sends antibodies to your liver tissues, causing inflammation (hepatitis). These antibodies are normally supposed to attack infections in your liver tissues. But in autoimmune disease, your immune system mistakenly attacks your own healthy cells instead.

Autoimmune hepatitis causes chronic inflammation in your liver, which may cause serious damage over time. Like other types of chronic hepatitis, autoimmune hepatitis can lead to scarring of your liver tissues (cirrhosis). Medical treatment can help reduce the inflammation and prevent complications from developing. However, in the early stages of the disease, you may not have symptoms.

What are the two main types of autoimmune hepatitis?

The different types of autoimmune hepatitis (AIH) involve different autoantibodies that scientists can recognize on an antibody test. These different antibodies attack different types of cells in your liver.

Type 1

Type 1 AIH, the “classic” type, is also the most common. It makes up about 80% of diagnosed cases, and it can affect anyone. Type 1 involves anti-smooth muscle antibodies (ASMA) that attack the smooth muscle cells in your liver. Type 1 has also been called “lupoid hepatitis” because its clinical symptoms resemble those of systemic lupus erythematosus. An ASMA blood test can help distinguish the two.

Type 2

Type 2 AIH is more rare and often more severe. It tends to appear earlier, usually during childhood, and progresses faster than type 1. Type 2 involves anti-liver-kidney microsome type 1 antibodies (anti-LKM-1), or anti-liver cytosol type 1 antibodies (anti-LC1). Anti-LKM-1 antibodies target a protein in your liver cells called cytochrome P450-2D6 (CYP2D6). Anti-LC1 antibodies are liver antibodies specific to type 2 AIH.

How rare is autoimmune hepatitis?

Autoimmune hepatitis is uncommon and its exact prevalence is unknown. European studies suggest that between .010% and .025% of the European population is affected. It appears to affect all racial and ethnic groups, but research has found it’s more common among Alaska Natives, affecting about .043% of that population. It’s also more common in women and people assigned female at birth (AFAB), by a ratio of 4:1.