What Are Autoimmune Diseases?

• Autoimmune diseases are a family of more than 80 chronic, and often disabling, illnesses that develop when defects in the immune system lead the body to attack its own cells, tissues, and organs.¹
• Some common autoimmune diseases include rheumatoid arthritis, lupus, multiple sclerosis and Type 1 diabetes.¹

What Causes Autoimmune Diseases?

• The cause of autoimmune disease remains unknown. However, fundamentally all autoimmune diseases are a consequence of impaired immune function that results from a mix of genetic and environmental factors.¹
• Approximately one-third of the risk of developing an autoimmune disease can be attributed to heredity.¹
• Other non-inherited risk factors may include environmental triggers, such as exposure to infectious agents (e.g., virus, bacteria), and lifestyle considerations, such as nutritional factors that may affect immune function.¹
• In the past decade, clinical and laboratory research has suggested that certain immune cells called B-cells may have a stronger influence on the development and progression of various autoimmune diseases than previously thought.²

What Is the Prevalence of Autoimmune Diseases?

• For reasons poorly understood, the incidence and prevalence of autoimmune diseases is rising.¹
• Collectively, autoimmune diseases are among the most prevalent diseases in the U.S., affecting between 14.7 and 23.5 million people — up to 8 percent of the population. ¹
• Research suggests that autoimmune diseases may run in families.¹
• Most of these diseases disproportionately afflict women, and are among the leading causes of death for young and middle-aged women.¹
• Estimates suggest that 75 percent of autoimmune diseases occur in women, most frequently during the childbearing years.³

How Is Autoimmune Diseases Diagnosed?

• Diagnosing autoimmune diseases can be particularly difficult, because these disorders can affect any organ or tissue in the body and produce a wide variety of signs and symptoms. ¹
• Many early symptoms of these disorders — such as fatigue, joint and muscle pain, fever or weight change — are nonspecific.¹
• Symptoms are often not apparent until the disease has reached a relatively advanced stage.¹
• Diagnosis typically involves many steps, including the following:
• Reviewing health history.
• Determining family history of autoimmune diseases.
• Conducting blood tests for the presence of specific autoantibodies — antibodies that react against the body's own cells and tissues — which can be a strong indicator of an autoimmune disorder.²

References ¹ Progress in Autoimmune Diseases Research, Report to Congress, National Institutes of Health, The Autoimmune Diseases Coordinating Committee, March 2005, forward and pages i, 1, 2, 16, 17, 28, 29, 30, 32, 52.
² Stevenson, F. and Natvig, J. Autoantibodies revealed: the role of B-cells in autoimmune diseases. Immunol. Today 1999 Jul;20(7):296-8.
³ U.S. Department of Health and Human Services Office on Women's Health. "Autoimmune Diseases in Women." http://www.4women.gov/FAQ/autoimmune.htm, accessed 2/9/06.