| What Are Autoimmune
Diseases?
The word "auto" is the Greek word
for self. The immune system is a complicated network of cells and cell
components (called molecules) that normally work to defend the
body and eliminate infections caused by bacteria, viruses, and other
invading microbes. If a person has an autoimmune disease, the immune
system mistakenly attacks self, targeting the cells, tissues, and organs
of a person's own body. A collection of immune system cells and molecules
at a target site is broadly referred to as inflammation.
There are many different autoimmune diseases, and they can each affect the
body in different ways. For example, the autoimmune reaction is directed
against the brain in multiple sclerosis and the gut in Crohn's disease. In
other autoimmune diseases such as systemic lupus erythematosus (lupus),
affected tissues and organs may vary among individuals with the same
disease. One person with lupus may have affected skin and joints whereas
another may have affected skin, kidney, and lungs. Ultimately, damage to
certain tissues by the immune system may be permanent, as with destruction
of insulin-producing cells of the pancreas in Type 1 diabetes mellitus.
Who Is Affected by Autoimmune
Diseases?
Many of the autoimmune diseases are rare.
As a group, however, autoimmune diseases afflict millions of Americans.
Most autoimmune diseases strike women more often than men; in particular,
they affect women of working age and during their childbearing years.
Some autoimmune diseases occur more frequently in certain minority
populations. For example, lupus is more common in African-American and
Hispanic women than in Caucasian women of European ancestry. Rheumatoid
arthritis and scleroderma affect a higher percentage of residents in some
Native American communities than in the general U.S. population. Thus, the
social, economic, and health impact from autoimmune diseases is
far-reaching and extends not only to family but also to employers,
co-workers, and friends.
How Are Autoimmune Diseases
Treated?
Autoimmune diseases are often chronic,
requiring lifelong care and monitoring, even when the person may look or
feel well. Currently, few autoimmune diseases can be cured or made to
"disappear" with treatment. However, many people with these
diseases can live normal lives when they receive appropriate medical care.
Physicians most often help patients manage the consequences of
inflammation caused by the autoimmune disease. For example, in people with
Type 1 diabetes, physicians prescribe insulin to control blood sugar
levels so that elevated blood sugar will not damage the kidneys, eyes,
blood vessels, and nerves. However, the goal of scientific research is to
prevent inflammation from causing destruction of the insulin-producing
cells of the pancreas, which are necessary to control blood sugars.
On the other hand, in some diseases such as lupus or rheumatoid arthritis,
medication can occasionally slow or stop the immune system's destruction
of the kidneys or joints. Medications or therapies that slow or suppress
the immune system response in an attempt to stop the inflammation involved
in the autoimmune attack are called immunosuppressive medications. These
drugs include corticosteroids (prednisone), methotrexate, cyclophosphamide,
azathioprine, and cyclosporin. Unfortunately, these medications also
suppress the ability of the immune system to fight infection and have
other potentially serious side effects.
In some people, a limited number of immuno-suppressive medications may
result in disease remission. Remission is the medical term used for
"disappearance" of a disease for a significant amount of time.
Even if their disease goes into remission, patients are rarely able to
discontinue medications. The possibility that the disease may restart when
medication is discontinued must be balanced with the long-term side
effects from the immunosuppressive medication.
A current goal in caring for patients with autoimmune diseases is to find
treatments that produce remissions with fewer side effects. Much research
is focused on developing therapies that target various steps in the immune
response. New approaches such as therapeutic antibodies against specific T
cell molecules may produce fewer long-term side effects than the
chemotherapies that now are routinely used.
Ultimately, medical science is striving to design therapies that prevent
autoimmune diseases. To this end, a significant amount of time and
resources are spent studying the immune system and pathways of
inflammation. |