Autoimmune hepatitis (AIH) is a chronic (long term of more than six months duration) ongoing inflammation in the liver, due to body’s own immune system attacking the cells of the liver (hepatocytes).
Human body has defense mechanisms in the form of immune cells to protect from external infections such as bacteria or viral etc. When this self-defense starts recognizing cells as foreign antigens and mounts an inflammatory response, it’s called autoimmune disease. If this happens in joints, it’s called arthritis; in lungs, it’s called asthma; in liver, it’s called autoimmune hepatitis.
Two main subtypes have been identified:
- Type 1 AIH
- More common
- Can occur at any age
- 50% people with type 1 AIH have other autoimmune disorders, such as celiac disease, rheumatoid arthritis, ulcerative colitis, or type 1 diabetes
- Type 2 AIH
- Occurs mainly in children and young persons
- Adults can also develop this condition
- Other autoimmune diseases may also be present
The exact cause for AIH remains unclear, but if left untreated, AIH can lead to severe liver tissue scarring (fibrosis), cirrhosis and eventually liver failure.
- Female gender, around 45 years; risk is three to four times greater compared to men
- After exposure to certain infections such as measles, herpes simplex or Epstein-Barr virus. AIH is also associated with hepatitis A, B or C infection
- Genetic (hereditary) predisposition
- Environmental factors can be triggers
- In persons already having an autoimmune disorder such as celiac disease, rheumatoid arthritis, or hyperthyroidism (Graves’ disease or Hashimoto’s thyroiditis)
- Taking certain medications such as nitrofurantoin (usually used to treat or prevent urinary tract infections) and minocycline (an antibiotic usually used to treat acne and some types of bacterial skin infections) carry a risk for drug induced AIH
- Feeling more tired than normal (fatigue)
- Feeling generally unwell
- Abdominal bloating and discomfort
- Reduced appetite and weight loss
- Joint pains
- Mild joint or muscle pains, usually worse in the mornings
- Abnormal menstrual periods
- Spontaneous abortions
- Swelling in the legs, feet and ankles
- Swollen abdomen (ascites)
- Jaundice –yellowish tinge in the whites of the eyes, yellowish tinge to the skin
- Bruising of the skin
- Dark or high coloured urine
- Routine blood tests
- Liver tests
- Raised enzyme levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) indicate severity of the liver inflammation. In AIH, the levels of AST/ALT is 2-3 times upper limit of normal
- Immunoglobulins (Igs) in the blood are raised in the presence of infections and inflammatory conditions. Serum IgG elevation occurs in 80% of the cases with AIH and is usually ≥1.5 times the upper limit of normal. These levels are important markers of disease activity
- Antibody tests for ANA, ASMA or Anti-LKM1 in titers >1:80 is diagnostic of AIH; however, in about 20% of patients ANA, ASMA, and anti-LKM1 can be negative. In such persons, additional antibodies may be present such anti soluble liver antibody (anti-SLA), anti-LC1, and anti-liver-kidney microsomal antibody type 3 (anti-LKM3)
- Imaging like USG abdomen or CT abdomen will give information about cirrhosis and its complications if any.
- Transient elastography is a quick non-invasive technique which uses shear wave velocity to define the stiffness in liver. The stiffness can be because of ongoing inflammation or permanent damage leading to fibrosis. It is a useful modality to define the response to medical management.
- Liver biopsy is the gold standard test which should be done before starting treatment for autoimmune hepatitis. It’s usually done under ultrasound guidance.
- Essential in established AIH
- Usually over long-term or lifelong
- By immunosuppression (reduces the activity of the body’s immune system)
- Goal is to prevent and halt the progression of liver damage
- Improves symptoms and liver test results
Early AIH may not produce any symptoms. When symptoms do appear, they can range from mild to severe symptoms. Mild symptoms are very non-specific and AIH, as such, may not be suspected:
Severe symptoms occur late in the disease, and may include:
The diagnosis is made by carrying out tests that can rule out common causes of liver disease and secondly to understand the extent of liver damage along with its complications.
Persistent inflammation and damage leads to cirrhosis as an end result. Usually patient with decompensated liver cirrhosis secondary to autoimmune hepatitis do not respond or develop more side effects to medical management such as steroids etc. Such patients should be considered for timely liver transplantation as a long term definitive cure.
AIH can be treated in most cases if diagnosed early and treatment initiated to prevent further damage and enhance the recovery.