Definition and Overview
The immune system is the body’s defense against many illnesses and diseases. Its network of cells, tissues, and organs make antibodies that kill pathogens before they can cause damage to the body. This prevents infections and keeps people healthy.
However, the immune system can sometimes attack healthy cells by mistake. If it attacks the liver, a person will develop autoimmune hepatitis (AIH).
The liver works with the intestines and pancreas to digest, absorb, and process food. It also filters blood that flows from the digestive tract and produces bile. This is a dark green or yellowish brown fluid that assists with fat digestion and absorption. The liver also detoxifies chemicals and metabolises drugs.
AIH causes the liver to become inflamed. If left untreated, it can lead to cirrhosis. This is a condition in which healthy liver tissues are replaced by scar tissues. Scar tissues can block normal blood flow through the liver. This can lead to liver failure.
What causes AIH is unknown. But doctors believe that it has something to do with the interaction of genes that control the function of the immune system with certain environmental triggers. These triggers include medications and pathogens.
There are two types of AIH. They are simply referred to as type 1 and type 2. The former is the more common type. It often occurs with other autoimmune diseases. The latter, on the other hand, is very rare. It commonly occurs in young girls between the ages of 2 and 14. It can also occur with other autoimmune diseases.
Causes of Condition
The disease occurs due to a problem with the body’s own immune system. Instead of keeping pathogens at bay, it releases autoantibodies that attack healthy cells and tissues. Attack to the liver cells results in AIH.
What causes the immune system to attack healthy cells, tissues, and organs is unknown. Factors that are known to increase its risk are:
Age and gender - The disorder is more common in women aged between 14 and 40 years old.
Other autoimmune disorders
A history of certain infections
A family history of the disease
There is no cure for the condition. It is treated with drugs that stop the immune system from attacking the liver.
The first signs of the disease are fever, muscle pain, and pain in the abdomen. Other symptoms are the yellowing of the whites of the eyes and skin. A skin rash may also occur.
As the disease progresses, patients may also notice:
Spider-like blood vessels on the skin
Itching due to the buildup of toxins and bile
If not treated promptly, the condition can lead to liver cirrhosis and then liver failure. These can cause the following symptoms:
Bleeding and bruising easily
Ascites or fluid build up in the abdomen
Swelling in the legs
Breast enlargement in men
Confusion or disorientation
Sleepiness and a general feeling of unwell
Who to See and Types of Treatments Available
AIH is diagnosed with blood tests and a liver biopsy. Blood tests can rule out viral hepatitis. They can also determine the type of AIH the patient has. AIH diagnosis can be confirmed with a liver biopsy. In this procedure, a long needle is inserted into the abdomen. This allows the doctor to remove a small piece of liver tissue. The sample is then sent to a laboratory for testing.
The results of both tests help doctors assess the extent of the condition. This is important in choosing the best possible treatment for the patient.
AIH is treated with immunosuppressants. These are a type of drug that stops the immune system from attacking the liver. They work by lowering the activity of the immune system. Patients have to take them for the rest of their lives. If the drug is discontinued for any reason, the disease will return. Many patients respond well to medical therapy. But prolonged use of such medications has many side effects. These include osteoporosis, diabetes, and high blood pressure as well as glaucoma and cataracts.
A liver transplant may become necessary if the patient is not responding well to medications. It can also be advised in severe cases. For this procedure, the patient’s damaged liver is removed. It is then replaced with a healthy liver from a living or deceased donor. In a living-donor transplant, only a portion of the healthy liver is given to the recipient. A portion remains in the donor’s body. Both livers will begin to regenerate right after surgery. The procedure often delivers great results. Its five-year survival rating is 70-80%.
Feldman, M, et al. Autoimmune hepatitis. In: Sleisinger and Fordtran’s Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. 10th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. http://www.clinicalkey.com.
Lim, Kie N.; Casanova, Roberto L.; Boyer, Thomas D.; Bruno, Christine Janes (2001). “Autoimmune hepatitis in African Americans: presenting features and response to therapy”. The American Journal of Gastroenterology. 96 (12): 3390–3394. ISSN 0002-9270. doi:10.1111/j.1572-0241.2001.05272.x.