Autoimmune Diseases & The Immune System

[lady_express_44]

Autoimmune Diseases
"Very simply stated, autoimmune disorders occur when the immune system confuses normal body tissue, "self", with a foreign intruder, and attacks it. How can this happen? As a way to avoid being attacked by the immune system, some infectious organisms, such as bacteria and viruses, learn to expose only those parts of themselves that mimic "self" tissue. Bacteria and viruses are made from chains of protein as are our bodies. The foreign invader exposes a segment of it’s protein chain (called an antigen) that looks something like the protein chain of self tissue; and when the immune system mounts it’s attack against these foreign organisms by detecting it’s antigen, it inadvertently targets the "self tissue" to be attacked and destroyed.

The Immune System
Our bodies are continuously under attack from foreign invaders such as environmental toxins, pollutants, and germs. The immune system is our bodies natural defense mechanism against these attackers. The immune system is made up of white blood cells, organs and structures whose mission it is to identify and destroy disease causing organisms such as bacteria, viruses, fungi, and parasites. It’s the immune systems job to protect the body against these foreign invaders. Immunology is the study of the immune system. It’s medical research includes all the cells, chemicals, and organs that defend the body against disease.

There are basically four types of infectious organisms that attack our body: bacteria, viruses, fungi, and parasites. Bacterium is the smallest living organism that can eat, grow, and multiply on it’s own. Viruses are not self-sufficient and must invade living cells, using that cells own machinery in order to reproduce. A virus must invade, destroy, and occupy another cell to live. Fungi is a life form slightly more advanced than bacteria but not as developed as plants, and include molds, rusts, mildews and yeast. Parasites are organisms that feed, grow and take shelter in other organisms acting as the host. The immune system must identify and destroy these foreign invaders.

The White Blood Cells
The white blood cells are the back bone of the immune system. There are many different kinds of white blood cells that have specific jobs to perform. There are however three common characteristics that all white blood cells have: each contain a nucleus, each primarily serves an immune function, and each white blood cell is believed to be produced by the same parent cell called the stem cell in the bone marrow. To simplify matters let’s classify white blood cells into four main types: the B-cell (bone marrow/bursa), which produces antibodies and primarily fight off bacteria; the T-cell (thymus), which fights off viruses, and allerts many other immune responses; the nonspecific effector cell which can kill and eat foreign intruders; and the compliment cell which will either notify other immune cells to respond or may begin destroying an invader by punching holes in it’s outer sheath. Cells from the spleen, lymph nodes, liver, bone marrow, lungs and intestines are also part of the immune system and help to dispose of pollutants in the blood. This is called the reticuloendothelial system (RES).

How The Immune System Works
The immune system is able to identify intruding organisms as being foreign because the protein chain, antigen, of the organism is different from self cells. The B-cell specializes in detecting bacteria and other organisms living outside the body’s self cells. The B-cell carries different antibodies on it’s surface, each responding to a different invader. When detection of a foreign invader occurs, a portion of the B-cell transforms rapidly secreting antibodies to attack the invader. The remaining B-cell becomes a memory cell to remain on alert and to detect any future attacks.
The T-cell specializes in detecting viruses and other organisms that are found inside the bodies own cell. The T-cell detects viruses by recognizing the viruses unique genetic code. When a foreign invader attacks, it is detected by one type of T-cell, which then orchestrates a multilayered immune response that includes stimulating B-cell secretion of antibodies, and signaling other T-cells to destroy infected cells; and still others for inflammatory response. The T-cell also produces a memory cell to recognize any future attacks.

The white blood cells that make up the immune system are very complex and this is a very simple explanation of the process. There are other groups of white blood cells that attack parasites and fungi and still others that belong to the lymph system. So you can see just how complex the immune system is.

Autoimmunity
The immune system must detect self cells from foreign or invaded cells. Every person’s self cells are inscribed with a unique "serial number", called the HLA (human leukocyte antigen), that lets the immune system know this cell is a self cell. This serial number is a unique group of proteins called (self) antigens. Antigens are found on almost every cell in the body and are determined by a particular segment of our DNA (deoxyribonucleic acid). The immune system differentiates self antigen from foreign antigen.

In autoimmune diseases, a foreign antigen mimics a group of self proteins, and then when the immune system mounts an attacking response against these foreign invaders, it inadvertently attacks and destroys self tissues. This cross-reaction occurs when the immune system is primed to attack the foreign antigen and any similar antigen, which in this case is the self.

Virtually any organ in the body can be the target for autoimmunity. A virus called adenovirus type 2 looks remarkably similar to the composition of the myelin sheath, which is the protective covering around the nerves and parts of the brain. When the immune system attacks this virus it can also mistakenly attack the myelin sheath causing multiple sclerosis, MS; a disease that causes numbness, tingling, weakness, visual impairment, loss of coordination and other disturbances. Similarly, a certain strain of streptococcal bacteria causes the immune system to attack the valves of the heart leading to rheumatic fever. Autoimmunity of the joints results in rheumatoid arthritis. With myasthenia gravis, the connections between nerves and muscles is affected. In Hashimoto’s thyroiditis, the immune system targets and destroys the thyroid; while with Grave’s disease, the immune system causes the thyroid gland to secrete excessive amounts of it’s hormone.

Skin is targeted in pemphigus vulgaris characterized by blistering of the skin and mouth; and psoriasis characterized by thick, scaling plaques of skin. An unidentified antigen causes sarcoidosis, a inflammation disease appearing in multiple organs, such as the lungs, livers, skin and eyes. System lupus erythematosus or Lupus affects the collagen, the connective tissue, and in turn that can affect almost every organ system in the body. Ulcerated colitis and Crohns disease affects the digestive systems.

There is no cure for stopping autoimmunity. Most treatment of autoimmune diseases is usually aimed at lessening the severity of symptoms and replacing the missing hormones when a gland is destroyed. If the immune system becomes too hyperactive, immunosuppressive drugs are administered.

Approximately half of all persons afflicted with autoimmune diseases experience periods of spontaneous remission. It is known that stress can tend to exacerbate symptoms.

No information in this letter should be construed as medical advice.
This information is for educational purposes only.

Jeff Frankel

http://www.healinglight.com/autoimmune/whatis.html
_________________
You can tell whether a man is clever by his answers.
You can tell whether a man is wise by his questions.
Naguib Mahfouz