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Women and Autoimmune DiseaseThe Mysterious Ways Your Body Betrays Itself
By Robert Lahita
HarperCollins Publishers, Inc.Copyright © 2006 Robert Lahita
All right reserved.
Part One: What Is an Autoimmune Disease?
For most of us who go about the everyday tasks of work, shopping, or life in general, the immune system does not seem particularly remarkable. Why would it be? Few movies of the week have been made about it. There are no weekend telethons on its behalf. It does not have a star such as Britney Spears anxious to attach her name to it, nor does Katie Couric remind us to have it checked every year, or two, or five.
No, it is just there, doing its job of protecting us from the, oh, say 5 or 6 billion molecules of viruses, bacteria, parasites, pollutants, and germs to which we open our doors--not to mention our mouths-- every single day of our lives. When things are going smoothly, we are all a bit guilty of a laissez-faire attitude about the immune system. Ah, but let something go awry and watch out! Now it has our attention.
And well it should.
We cannot live, at least not very well, without our immune systems. The immune system is the body's natural defense mechanism against the attackers I have cited above--as well as many as-yet-unknown microbes that would love nothing more than to climb inside and set up shop all over our bodies. To get a good sense of the might of this silent but hardworking system, consider what happens to something livingonce it dies: Within minutes, everything shuts down; within hours the process of decomposition sets in, and long before sunset, the body is completely taken over by all sorts of unwelcome visitors. I need not go further. You get the picture.
If you are in any way concerned about autoimmune disease--and I suspect you are if you're reading this book--it is essential that you understand the basic workings of the healthy immune system. This chapter explains it, but be forewarned; in large part, it will be a vocabulary lesson. Many of the terms I use here are repeated throughout the book, so it is helpful to understand them from the first. I do promise this, however: To the extent that it is possible to illustrate things clearly otherwise, I will not burden you with so much as an extraneous microbe.
Central to the workings of the immune system is its ability to distinguish between what is "us" and what is "not us," hereafter known as self and nonself. Every cell in the body carries distinctive molecules that distinguish it as "self." When foreign--"nonself"--molecules enter the body, if they trigger an immune reaction, they are known as antigens (against self).
Antigens can come from outside the body or may actually exist as part of the body itself. An external antigen could be a bacterium, a virus, or a parasite, for example. Tissues or cells from other humans, such as those introduced during a heart or lung transplant, also are recognized as antigens, which is why, without strong drugs to suppress the immune system, the body rejects transplanted organs. As soon as the immune system recognizes an antigen in the bloodstream, it responds by producing antibodies, which are molecules designed to counteract the antigen and render it impotent. The process of creating an antibody upon recognition of an antigen is known as an immune response.
For an example of an internal antigen, there are times when the im- mune system suddenly turns on the hair follicles, mistakenly recognizing them as foreign and makes antibodies against them. This constitutes an autoimmune response that can result in an autoimmune disease called alopecia areata universalis, or complete loss of hair. The hair follicle itself has become the antigen and is now called an autoantigen. Why cells in the body that heretofore coexisted in peace suddenly become the enemy, no one knows.
The organs that comprise the immune system include the bone marrow, the lymph nodes, the thymus, and the spleen. These organs are connected to each other and to other organs of the body by way of the lymphatic vessels, a network that courses throughout the body in a manner similar to the blood vessels.
The bone marrow serves as the factory that produces, among other things, the white blood cell (also known as leukocytes) a collection of different kinds of cells, such as polymorphonuclear leukocytes (phagocytes), monocytes, and lymphocytes. They are considered the backbone of the immune system, and many of them are described below.
The lymph nodes are small bean-shaped structures that contain filter tissue and work as the clearinghouse for germs and foreign invaders. They are the place where the immune cells face off with antigens. Using a police force as an analogy for the immune system, you might consider the lymph nodes as police precincts that are strategically placed in various parts of the body where the immune system has to be on high alert--for example, the tonsils, the ears, the mouth, the genitals, or any area where there might be an invasion of a foreign substance or a foreign germ. When fighting a bacterial infection, for example, the nodes are the battleground for bacteria and the immune cells that are fighting them. The result of this influx of cells and cell activity is a swollen lymph node, which is a good predictor that an infection exists.
The thymus, which is located in the middle of the chest under the breastbone and below the thyroid gland, is the master programmer of the immune system. Interestingly, the thymus usually disappears by Organs of the Immune System...
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