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Common Autoimmune Diseases of the Human Body
The immune system is a complicated network of cells and cell components (called
the Lymphatic system) that normally work to defend the body and
eliminate infections caused by bacteria, viruses, and other invading microbes.
The immune response system recognizes pathogens and
acts to remove, immobilize, or neutralize them.
The immune system can recognize millions of distinctive foreign molecules and
produce its own molecules and cells to match up with and counteract each of
them. It is antigen-specific (responding to specific molecules on a pathogen)
and has memory (its defense to a pathogen is encoded for future activation).
Autoimmune "Diseases"
An autoimmune disease or disorder is where the
body is allergic to itself. It is not really a disease; it is more a disorder,
as no pathogen is involved with generating the disorder directly. (see more info
below).
If a person has an autoimmune "disease", the immune system
mistakenly attacks the body itself, targeting the cells, tissues, and organs of
a person's own body because the immune system mistakenly considers the body
tissue cells as a pathogen. A collection of immune system cells and molecules at
a target site is broadly referred to as inflammation .
How the Autoimmune Function is
initiated
When the body attacks itself, it
utilizes the same process that occurs in a normal immune response. Every cell in
the body displays proteins on its surface. These proteins distinguish the
various cells of the body as part of different tissues of the self. The
difference in autoimmune diseases is that the normal protein on the wall of a
normal cell is inadvertently recognized as a foreign antigen and thus subject to
destruction by the T cells.
In other words the classification on autoimmunity
as a disease, is not really a disease but an immune system that is out of
whack; the immune system mistakenly interacts with the body's antigens rather
than foreign antigens causing the destruction of the body's cells.
Etiology of the Autoimmune Disorder:
As cells mature in the thymus, self-reacting
cells, cells which attack the human body, are often produced. In normal
systems, these cells are eliminated. For reasons that are not well
understood, this elimination process sometimes fails leading to an autoimmune
disorder. This failure may be due to chemical, physical or biological
factors. Viral initiation has not been ruled out as a cause of autoimmune
diseases because the antigens produced by the virus may be similar to human
antigens or MHC proteins, creating a phenomenon known as cross-reaction.
Origins of Autoimmune Disorders:
The origin of autoimmune diseases is unknown, although some hypotheses have ben put forward, most centering on some type of stress or multiple stresses.
These stresses might be:
- genetic factors or mutations
- Inherited factors. Thyroid and adrenal autoimmune disorders appear to
run in families, with women, for the most part, being the carriers.
- The majority of persons afflicted with autoimmune diseases are women.
A woman's immune system is much stronger than a males because of her
ability to give birth, making her more susceptible to an autoimmune
disease.
- environmental
- infection
- ultraviolet light
- extreme stress
- certain drugs and antibiotics
- radioactivity
- morbidity evidence from the Kiev area of the Ukraine has shown that
thyroid problems have increased by seven times in children living
downwind of Chernobyl after the 1986 plant versus children living
upwind. It seems the thyroid collected radioactive iodine from the
fallout, causing unusually high amounts of antibodies in the thyroid
cells.
- vaccines, which contain low doses of viruses, are also thought to
trigger some autoimmune diseases, but little research has been done in
this area to date. Genetic predisposition could also influence the
susceptibility to some autoimmune diseases.
Cross Reaction
Cross-reaction occurs during a viral infection when lymphocytes
attack both the viral and human antigens, both infected and normal cells.
Major autoimmune diseases
There are many different autoimmune diseases, (over 100) and
they can each affect the body in different ways. However, the major disease
are show in in the table below.
| Autoimmune Disorder |
System Affected |
|
Addison's Disease |
Adrenal Gland |
|
Crohn's Disease |
Large Intestine |
|
Graves' Disease |
Thyroid Gland |
|
Hashimoto's Thyroiditis |
Thyroid Gland |
| Insulin-dependent diabetes mellitus |
Pancreatic Beta Cells |
|
Multiple Sclerosis |
Brain and Spinal Cord |
|
Psoriasis |
Skin |
| Rheumatoid Arthritis |
Connective Tissues |
| Spontaneous Infertility |
Sperm |
|
Systematic Lupus Erythematosus |
DNA, Platelets, and other tissues |
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