These antibodies target a human body’s produced enzyme called cytochrome P450 2D6, a protein found primarily in liver cells which catalyze many reactions involved in drug metabolism. The development of the LKM antibodies is strongly associated with type 2 autoimmune hepatitis.

What is Autoimmune hepatitis?

Autoimmune hepatitis is an acute or chronic inflammation of the liver that can lead to liver cirrhosis and, in some cases, to liver failure. Just why the body turns against itself is unclear, but researchers think autoimmune hepatitis could be caused by the interaction of genes controlling immune-system function and exposure to particular viruses or drugs.

Although adults can develop type 2 autoimmune hepatitis, it’s most common in children and young people. Other autoimmune diseases may also accompany this type of autoimmune hepatitis.

Signs and symptoms include:

• Yellowish skin and eyes (jaundice)

• Enlarged liver

• Itching, sometimes over the whole body

• Skin rashes

• Lack of appetite

• Nausea, vomiting, or both

• Joint pain

• Belly (abdominal) pain or discomfort

• Broken blood vessels on the skin, often in a “spider” shape

• Dark urine

• Pale stools

• Tiredness

Risk Factors may include:

• Being female.
• A history of certain infections. Autoimmune hepatitis may develop after you’re infected with the measles, herpes simplex or Epstein-Barr virus. The disease is also linked to hepatitis A, B or C infection.
• Heredity. Evidence suggests that a predisposition to autoimmune hepatitis may run in families.
• Having an autoimmune disease. People who already have an autoimmune disease, such as celiac disease, rheumatoid arthritis or hyperthyroidism (Graves’ disease or Hashimoto’s thyroiditis), may be more likely to develop autoimmune hepatitis.

References: 

• Clinical Immunology Principles and Practice. Third edition. Edited by RR Rich, TA Fliesher, WT Shearer, et al: Philadelphia, PA, Mosby Elsevier, 2008
• Czaja AJ, Homburger HA: Autoantibodies in liver disease. Gastroenterology. January 2001;120(1):239-249
• Frequency and significance of antibodies to liver/kidney microsome type 1 in adults with chronic active hepatitis. (https://www.ncbi.nlm.nih.gov/pubmed/1397887)