By Alan Koenigsberg, M.D.

While cutting a tomato, we cut our finger…amazingly, it heals itself over the next few days and weeks, without our needing to do much!

We get a bad cold and similarly, a few days later, it seems to mysteriously go away.

On the other hand, some of us get congested during hay fever season, and bemoan that allergies have struck.

What’s going on here? Well, the human body has developed an amazing set of systems to protect itself. Some are passive, like the largest organ of the body, our skin, to protect us from many external dangers.

Others are active, such as skin healing and the immune system. This article will focus on our immune system, in health and illness.

Our immune system consists of many individual components. There are lymph glands, located throughout the body, which act as collectors for germs. Some are in our neck, armpits and groin, and we can feel them when they are swollen. For instance, if we have a sore throat, we may feel swollen lymph glands in our neck, the region that drains that area. Our tonsils and adenoids are other lymph glands.

The spleen, located on the left side of our abdomen, is the largest lymph gland.

Then there are the actual cells that attack invading bacteria and viruses.

Our skeletal system, our bones, is also a miraculous component of our bodies. We all know that our bones are the support system that holds our bodies up and that they have muscles attached which provide movement.

In addition, the inner parts of our bones, the marrow, actually are the sites of manufacture of red and white blood cells. The white blood cells are the part of our immune system that provides local immediate action, such as histamine release, which causes the inflammatory response, as well as antibodies that combat specific antigens, namely the bacteria and viruses that may invade our bodies.

In health, white mast cells release histamine, which causes swelling, heat and redness to surround, wall off and destroy skin infections. We may take an antihistamine after a bee sting, for example, or if we suffer from allergies.

If we have a systemic infection, such as a viral cold, various other white cells are manufactured in response to the specific virus — which is why that is a more delayed response — and attack and destroy the virus. The fever generated helps destroy the viruses.

The active immune system recognizes foreign proteins and that is what triggers it. The immune system does not react to inert non-protein substances. 

In order to protect itself effectively, the body must have some sort of mechanism to distinguish its own tissues, which are protein, from foreign ones, or it could just as easily manufacture antibodies to destroy its own cells.

Sometimes the immune system is indeed triggered to produce antibodies against its own cells, and these conditions are called autoimmune disorders.

The body does not recognize certain organs, parts of organs or membranes surrounding certain organs as its own tissues, and produces antibodies to attack those organs.

Examples of these conditions are rheumatoid arthritis (not osteoarthritis), type 1 diabetes, systemic lupus erythematous (SLE), multiple sclerosis, psoriatic arthritis, inflammatory bowel disease (Crohn and ulcerative colitis), celiac disease and many others.

In part two of this article, I’ll discuss some of the more common autoimmune conditions, their symptoms, and treatments.

Alan Koenigsberg, M.D., is a practicing psychiatrist and clinical professor of psychiatry at UTSW Medical School in Dallas. He can be reached at akoenigsberg@mac.com.