Autoimmune hepatitis (AIH) is a chronic autoimmune disorder that causes inflammation of the liver cells. It occurs when the body's immune system attacks its healthy cells and damages them mistakenly. The exact cause of autoimmune hepatitis is unknown; however, over time, genetic and environmental factors can trigger its manifestation. Undiagnosed and untreated autoimmune hepatitis can lead to cirrhosis (scarring of liver tissue) and eventually liver failure.
Causes of autoimmune hepatitis
AIH is autoimmune in nature, i.e., the body’s immune system cannot differentiate between healthy and abnormal cells and can destroy normal body cells. Liver inflammation, or hepatitis, may occur along with other autoimmune disorders such as Graves’ disease, inflammatory bowel disease, rheumatoid arthritis, scleroderma, Sjögren syndrome, systemic lupus erythematosus, thyroiditis, type 1 diabetes, ulcerative colitis, etc. AIH is more common in young girls and women.
Types of autoimmune hepatitis
Depending on the type of autoantibodies, there are mainly two forms of autoimmune hepatitis as mentioned below:
Type 1 autoimmune hepatitis: It is the most common form that occurs in any age group. It involves anti-smooth muscle antibodies (ASMA) and attacks the smooth muscles of the liver. People with type 1 AIH may have other autoimmune conditions as well.
Type 2 autoimmune hepatitis: It is more common in children and teenagers. It involves an anti-liver-cytosol type 1 antibody that attacks the liver cells. Other autoimmune disorder may also be present along with this form of autoimmune hepatitis.
Symptoms of autoimmune hepatitis
Autoimmune hepatitis signs and symptoms might differ from person to person. Some of the common ones include:
• Extreme tiredness (fatigue)
• Abdominal pain
• Mild-flu-like symptoms
• Yellowish discolouration of the skin and eyes (jaundice)
• Skin rashes
• Loss of appetite
• Joint pain or swelling
• Dark urine & pale stools
• Ascites (fluid accumulation in the belly)
• Rectal bleeding
• An enlarged liver
• Abnormal web-like blood vessels on the skin (spider angiomas)
• Loss of menstrual periods (amenorrhoea)
• Confusion, drowsiness, or disorientation (hepatic encephalopathy)
Diagnosis of autoimmune hepatitis
The diagnosis of AIH starts with a physical examination, followed by blood tests and imaging tests.
Blood tests
• Liver function tests: These tests are performed to check for inflammatory blood proteins and levels of liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as well as degree of liver damage. During the course of treatment, your healthcare provider may call for a liver function test (LFT) to monitor the treatment response.
• Complete blood count (CBC): It helps to determine the number (count) and types of blood cells.
• Electrolyte panel: It helps to determine the electrolyte imbalance in the body.
• Coagulation panel: It assists in determining how well your clotting proteins are functioning.
• Autoimmune antibodies: It helps to identify and differentiate autoimmune hepatitis from other autoimmune disorders. Anti-liver kidney microsome type 1 antibody (anti-LKM-1), anti-nuclear antibody (ANA), anti-smooth muscle antibody (ASMA), liver kidney microsomal antibody (LKM) and immunoglobulin G (IgG) are some autoantibodies that are tested to diagnose autoimmune hepatitis.
Imaging tests
• CT scan: It provides more detailed horizontal imaging of the liver than a standard X–ray.
• MRI: It provides detailed images of the liver using a dye that is seen more clearly.
• Ultrasound: It provides images of the liver using high-frequency sound waves. It also checks blood flow in blood vessels.
• Liver biopsy: It involves collecting a sample of liver tissue and then examining it under a microscope to determine the type of liver disease.
Treatment of autoimmune hepatitis
The goal of AIH treatment is to slow or stop the immune system response, thereby reducing an immune system attack on the liver. The common medications used to treat AIH are:
• Corticosteroids (steroids) – To reduce and suppress the inflammatory response.
• Immunosuppressant – To reduce and suppress the autoimmune response. They work better for long-term maintenance.
• Liver transplant – If medications don’t improve the disease condition, your liver may progress into irreversible cirrhosis or liver failure. Then the choice of treatment is a liver transplant. During a liver transplant, a diseased portion of the liver is removed and replaced with a healthy liver.
In most instances, autoimmune hepatitis cannot be prevented or cured completely. With early diagnosis and treatment, one can relieve symptoms and prevent or reverse the extent of liver damage. By knowing your risk factors and getting an early diagnosis followed by treatment of autoimmune hepatitis, the chances of developing cirrhosis and other advanced liver diseases can be reduced.