Autoimmune hepatitis, often referred to as AIH, is one cause of chronic hepatitis and can be, if untreated, one of the most severe forms.
For a long time AIH was known as chronic active hepatitis. AIH is just one of the causes of chronic active hepatitis but it is now recognised as a specific disease.
What causes AIH is not well understood.
It is believed the cells that do the damage are circulating blood cells known as lymphocytes. They behave as though the hepatocytes (the liver cells) are foreign and start to destroy them. This leads to chronic hepatitis which, if untreated, will progress to cirrhosis and eventually to liver failure.
How common is autoimmune hepatitis?Fortunately AIH is relatively uncommon although it occurs in both males and females.
Between the ages of 15 and 25, it is women who are mostly affected. Around the ages of 45 and 55, both men and women are affected.