Autoimmune Diseases

Disease Background

Autoimmune diseases are a group of diseases characterized by an abnormal immune system attack on an individual's own body tissue. The components of the immune system responsible for this effect are proteins called antibodies. These proteins, produced by white blood cells, typically are made in response to infections caused by pathogens such as bacteria or viruses. Each type of antibody is specific for a component of the bacteria or virus. The antibody targets a foreign protein from a pathogen for destruction by other immune system components.

In autoimmune diseases, normal molecules of the body are mistakenly recognized by antibodies and targeted for destruction. The destruction may be against a specific organ in the body or may be more widespread. Some examples of autoimmune diseases include lupus, rheumatoid arthritis and multiple sclerosis, but there are many others. In some cases, the specific tissue or protein targeted for destruction is known or strongly suspected. For example, in multiple sclerosis the immune system attacks the myelin sheath, the coating that surrounds and protects nerve fibers, causing a wide range of neurological symptoms.

Four of the most common types of autoimmune diseases include the following (click the link to learn more about Hutchinson Center research for that disease):

• Rheumatoid Arthritis (RA) is a chronic, systemic, inflammatory autoimmune disease that affects more than 2.5 million people in the United States. Like other autoimmune diseases, it affects women more than men.



• Lupus is a chronic autoimmune disease in which a person's immune system attacks the body, resulting in inflammation of various organs or tissues. According to the Lupus Foundation of America, Inc., more than 16,000 Americans develop lupus each year. It is estimated that 500,000 to 1.5 million Americans have been diagnosed with the disease, making it one of the most common types of autoimmune diseases.



• Multiple sclerosis is an autoimmune disease that impairs the nervous system. An estimated 350,000 people in the United States have been diagnosed with multiple sclerosis.



• Scleroderma is a chronic autoimmune disease. Its hallmark feature is fibrosis, which means hardening of the skin (derived from "sklero" or hard and "derma" referring to skin). About 100,000 Americans have scleroderma. Like many other autoimmune diseases, scleroderma occurs much more frequently in women than men. Scleroderma can range from a localized disease that primarily affects the skin to a more serious illness known as systemic sclerosis, causing damage to multiple parts of the body.