How Much Do You Know About Autoimmune Diseases?

AIDS stands for "acquired immunodeficiency syndrome," but this disease is not an autoimmune illness. It is caused by a virus (HIV), which damages the person's immune system. Autoimmune diseases include systematic lupus erythematosus, rheumatoid arthritis, psoriasis, type 1 diabetes, Crohn's disease, and multiple sclerosis.

Instead of focusing on invading bacteria or viruses, the antibodies zero in on the body's own tissues, organs, or cells.

Researchers don't know why this is so, but one theory suggests that the hormone estrogen may play a role.

Autoimmune disease can affect any organ in the body, although certain diseases attack specific organs. In Crohn's disease, for instance, the area affected is the gut. In multiple sclerosis, the areas affected are the brain and spinal cord.

Lupus is more common among African-American women. Hispanic women also are more likely to develop lupus.

Autoimmune diseases have a variety of causes, although doctors don't yet know them all. Some illnesses, such as rheumatic fever, develop after a streptococcal infection. People taking a particular medication for high blood pressure (methyldopa) can develop the autoimmune illness lupus (the condition usually reverses itself once the drug is halted, but not in every case). Some autoimmune diseases run in families, which suggests that genes play a role.

For many autoimmune diseases, the vague early symptoms and lack of specific lab tests make them a diagnostic puzzle for doctors.

But some autoimmune diseases, such as multiple sclerosis and rheumatoid arthritis, can go into remission, even without treatment. For the most part, though, autoimmune illnesses are chronic, needing lifelong monitoring and care. Medication can help reduce or stop the damage caused by some of the diseases. Medication can also help suppress the immune system's response, helping to ease symptoms caused by the disease.