<<Disclaimer: Verify this information before applying it to your situation.>>

This information is from the Dr. Koop internet site - it explains an immune
system disorder (i.e., Celiac Disease) and  Dr. Koop explains the
differences between an immune system disorder and an allergy.  The site
address: http://www.drkoop.com/adam/peds/top/000816.htm


Immune system disorders occur when the immune response is inappropriate,
excessive, or lacking. Autoimmune disorders develop when the immune system
destroys normal body tissues. This is caused by a hypersensitivity reaction
similar to allergies, where the immune system reacts to a substance that it
normally would ignore. In allergies, the immune system reacts to an external
substance that would normally be harmless. With autoimmune disorders, the
immune system reacts to normal "self" body tissues.

Normally, the immune system is capable of differentiating "self" from
"non-self" tissue. Some immune system cells (lymphocytes) become sensitized
against "self" tissue cells, but these cells are usually controlled
(suppressed) by other lymphocytes. Autoimmune disorders occur when the
normal control process is disrupted. They may also occur if normal body
tissue is altered so that it is no longer recognized as "self." The
mechanisms that cause disrupted control or tissue changes are not known. One
theory holds that various microorganisms and drugs may trigger some of these
changes, particularly in people with a genetic predisposition to an
autoimmune disorder.

Because autoimmune disorders and allergy are both caused by hypersensitivity
reactions, it is believed that a history of allergy indicates increased risk
for autoimmune disorders. However, autoimmune disorder have also been
statistically linked to left handedness.

Autoimmune disorders result in destruction of  one or more types of body
tissues, abnormal growth of an organ, or changes in organ function. The
disorder may affect only one organ or tissue type or may affect multiple
organs and tissues. Organs and tissues commonly affected by autoimmune
disorders include blood components such as red blood cells, blood vessels,
connective tissues, endocrine glands such as the thyroid or pancreas,
muscles, joints, and skin.

A person may experience more than one autoimmune disorder at the same time.
Some disorders have multiple interrelated causes, one of which is
autoimmunity. Examples of autoimmune (or autoimmune-related) disorders
include:
Hashimoto's thyroiditis
pernicious anemia
Addison's disease
diabetes mellitus
rheumatoid arthritis
systemic lupus erythematosus
dermatomyositis
Sjogren's syndrome
dermatomyositis
lupus erythematosus
multiple sclerosis
myasthenia gravis
Reiter's syndrome
Graves disease

___________________
R. David Nackerud
Portland, Oregon
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