Autoimmune Disorders: Overview

Autoimmune disorders are diseases caused by dysfunctions of the immune system * . They include such disorders as reactive arthritis, type 1 diabetes, multiple sclerosis, lupus, scleroderma, and psoriasis, among many others.

Autoimmune disorders are diseases resulting from dysfunctions of the body's immune system. The purpose of the immune system is to identify such foreign substances as bacteria * , viruses * , toxins * , cancer cells, and blood and tissue from outside the body (transplanted tissue) that enter the body and mobilize the body's defenses to fight the foreign substance. In autoimmune diseases, the immune system is unable to tell the difference between the body's own tissues, referred to as self, and organisms that are foreign, referred to as nonself. When the immune system incorrectly identifies the self as nonself, it may start fighting itself. One researcher states that there are more than 80 types of autoimmune disorders.

Diseases that are considered autoimmune include:

The number of people in the developed countries affected by autoimmune disorders is estimated to be between 2 and 5 percent of the population in those countries. Estimates of the number of people in the United States who have an autoimmune disorder vary, and range from 23.5 million to 50 million. The difference has to do with the number of diseases that are considered autoimmune disorders. The National Institutes of Health (NIH) lists 24 diseases as autoimmune. On the other hand, the American Autoimmune Related Diseases Association states that there are between 80 and 100 autoimmune diseases. More women than men are affected by autoimmune diseases. According to the NIH, autoimmune disorders are among the top 10 leading causes of death in girls and in adult women up to age 64.

There is some evidence that some people may have a genetic predisposition to an autoimmune disorder. This predisposition appears when there are several members of the same family who have the same or a similar autoimmune disorder.

People who have a family history of an autoimmune disorder are at greater risk of acquiring an autoimmune disorder. Women are at greater risk of an autoimmune disorder, as approximately 75 percent of people with autoimmune disorders are women. Women who are African American, Hispanic American, or Native American also have a higher risk of an autoimmune disorder than Caucasian women.

Signs of an autoimmune disease generally are related to the specific type and location of the impaired immune response. For example, a person with rheumatoid arthritis often experiences severe joint pain that results in joint deformity over time and a general feeling of tiredness. Some common signs of autoimmune disease are a general feeling of fatigue or tiredness, fever, joint pain, and rash.

The health care provider will obtain a detailed health history, including any specific health concerns that may suggest an autoimmune disorder. A physical examination will be conducted, and laboratory studies of blood and urine samples will be performed. Specific blood studies that may be done are a complete blood count (CBC), which looks at the different blood cells (for example, red blood cells [RBCs], white blood cells [WBCs], and erythrocyte sedimentation rate) and their functioning; antibodies * in the blood; and rheumatoid factor. X-rays and special diagnostic studies may be ordered, depending on the diagnoses that the doctor is considering. Abnormal findings will be evaluated to determine the cause.

Autoimmune disorders are considered chronic, which means that they cannot be cured, but symptoms may improve with effective medical management and healthy lifestyle habits.

Treatment focuses on the specific autoimmune disorder diagnosed. The goals of treatment include:

Drugs that suppress the activity of the immune system may be prescribed, but these medications carry the risk of the body's not being able to fight off influenza, pneumonia, and other infectious diseases.

See also Addison's Disease • AIDS and HIV Infection • Arthritis • Celiac Disease • Chronic Fatigue Syndrome • Collagen Vascular Diseases: Overview • Diabetes • Fever • Fibromyalgia • Guillain-Barré Syndrome • Immune Deficiencies • Immune System and Other Body Defenses: Overview • Lou Gehrig's Disease (Amyotrophic Lateral Sclerosis) • Lupus • Multiple Sclerosis (MS) • Myasthenia Gravis (MG) • Psoriasis • Sjögren's Syndrome • Thyroid Disease

* immune system (im-YOON SIStem) is the system of the body composed of specialized cells and the substances they produce that helps protect the body against disease-causing germs.

* bacteria (bak-TEER-ee-a) are single-celled microorganisms that typically reproduce by cell division. Some but not all types of bacteria can cause disease in humans. Many types can live in the body without causing harm.

* virus (VY-rus) is a tiny infectious agent that can cause infectious disease. A virus can reproduce only within the cells it infects.

* toxin is a poisonous substance produced within living organisms or cells.

* infection (in-FEK-shun) is a disease caused by microorganisms that release toxins or harmful substances. Infection can cause damage to body tissues or to the body as a whole.

* anemia (uh-NEE-me-yuh) is a blood condition in which there is a decreased amount of hemoglobin in the blood or fewer than the normal number of red blood cells.

* antibody is a protein molecule produced by the body's immune system to help fight a specific infection caused by a microorganism like a bacterium or virus.