An Overview of Autoimmune Hepatitis
Affecting an increasing number of people worldwide, hepatitis is a liver disease characterized by inflammation and/or destruction of liver cells. The most common cause of hepatitis is infection with one of the hepatitis viruses. Other causes include drug overdoses, alcohol abuse, bacterial infection, exposure to plant and chemical toxins, a reaction to certain drugs and the autoimmune condition known as autoimmune hepatitis (AIH).
The most prominent responsibility of the immune system is to protect the body from viruses, bacteria and other living organisms. A healthy immune system only reacts against invaders intending harm against the body, not its own cells. However, autoimmunity occurs when the immune system mistakenly attacks the cells it is supposed to protect. Researchers speculate that certain bacteria, viruses, toxins and drugs trigger an autoimmune response in people who are genetically susceptible to developing an autoimmune disorder.
In cases of autoimmune hepatitis, the body’s own immune system attacks its own liver cells. Known to occur after infection with Hepatitis A, B or C, autoimmune hepatitis is occasionally confused for a prolonged or relapsing viral hepatitis. Some additional, specific triggers of AIH include:
- The Epstein-Barr virus (EBV)
- The measles virus
- Salmonella bacteria
- Escherichia coli bacteria
In addition, the following medications have been suspected as AIH triggers:
- Alpha methyldopa
Autoimmune hepatitis accounts for 11 to 23 percent of all cases of chronic hepatitis in the United States, affecting 100,000 to 200,000 individuals. Researchers think a genetic factor may predispose some people to autoimmune diseases. About 70 percent of those with autoimmune hepatitis are women, most between the ages of 15 and 40. Similar to other forms of chronic hepatitis, untreated AIH can lead to scarring of the liver (cirrhosis), liver cancer and eventually to liver failure. However, early diagnosis and treatment can help control this illness from progressing.
Women represent about 80 percent of all cases of AIH and two major age groups are affected:
- Young people between ages 10 and 20
- People older than 55 years
Up to 17 percent of people with AIH have a second autoimmune disorder, predominantly autoimmune thyroid disease, including both Hashimoto’s thyroiditis and Graves’ disease. Other autoimmune conditions that typically coexist with AIH include pernicious anemia, autoimmune hemolytic anemia, rheumatoid arthritis, Sjogren’s syndrome, ulcerative colitis, myasthenia gravis, glomerulonephritis, celiac disease, vitiligo and type I diabetes.
Signs and Symptoms
Coming on suddenly or gradually, the signs and symptoms of autoimmune hepatitis can range from minor to severe. Although often asymptomatic, signs and symptoms typical of any type of hepatitis include:
- Abdominal discomfort
- Joint aches
- Yellowing of the skin and whites of the eyes (jaundice)
- An enlarged liver
- Abnormal blood vessels on the skin (spider angiomas)
- Nausea and vomiting
- Liver scarring (cirrhosis)
- Fluid in the abdomen (ascites) or mental confusion, in advanced cases
- Dry eyes and mouth (Sjogren’s syndrome)
Additionally, people with AIH may have the following signs and symptoms:
- Hemolytic anemia
- Chronic inflammation of the thyroid gland (thyroiditis)
- Inflammation of the colon (ulcerative colitis)
- Puffy facial features
- Hirsutism (increased facial hair)
- Pigmented abdominal striae or stretch marks
- Absent or decreased menstruation
The only way to differentiate one type of hepatitis from another is with laboratory tests. While lab tests will confirm the presence of a particular virus in cases of viral hepatitis, increased blood levels of gamma globulin and one or more antibodies that target the liver will detect AIH.
More specifically, a diagnosis of AIH is best achieved with a combination of the following clinical and laboratory findings:
- Antinuclear antibody (ANA)
- Smooth muscle antibody (SMA)
- Liver/Kidney microsomal antibody (LKM-1)
- Anti-mitochondrial antibody (AMA)
- Immunoglobulin G (IgG)
However, the diagnosis of autoimmune hepatitis always requires a liver biopsy.
Although chronic hepatitis due to a virus (such as Hepatitis B or C) is approached by physicians with drugs aiming to annihilate the virus, treatment for AIH is starkly different. Most successful when diagnosed and treated early, therapy for AIH is based on suppressing an overactive immune system.
Clinical studies demonstrate that sustained response to treatment cannot only stop AIH from getting worse, but also may actually reverse some of the damage. While the immunosuppressive drugs used to treat AIH can have significant side effects, approximately 70 percent of those undergoing treatment go into remission within two years of starting treatment. Unfortunately, a majority of AIH sufferers will need to continue with immunosuppressant therapy for years, if not for life. When medications don’t halt the progress of the disease or cirrhosis has developed or progressed to liver failure, the remaining option is a liver transplant – a procedure that’s often very successful in people with autoimmune hepatitis.
Unlike the various strains of viral hepatitis, autoimmune hepatitis is not contagious. Although not an infectious disease, AIH is a serious illness that can lead to irreversible cirrhosis and liver failure. Because early intervention has demonstrated the best success, those with liver concerns or who exhibit the signs and symptoms can benefit by being aware of and being tested for AIH.
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www.digestive.niddk.nih.gov, Autoimmune Hepatitis, National Digestive Diseases Information Clearinghouse, 2007.
www.gicare.com, Hepatitis, Jackson Siegelbaum Gastroenterology, 2007.
www.liverfoundation.org, Autoimmune Hepatitis, American Liver Foundation, 2007.
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