Autoimmune hepatitis is a disease characterized by chronic inflammation of the liver. The best way to describe this disease is to break the term down into its composite words. Autoimmune refers to the body’s own immune system attacking another part of the body. Hepatitis refers to inflammation of the liver, which can range from mild to severe. In the vast majority of patients, autoimmune hepatitis is marked by fluctuating levels of intensity, with relapses and remissions.