Anemia:

A medical condition caused by a reduced number of red blood cells, characterized by general weakness, paleness, irregular heart beat, and fatigue.

Antibody:

A chemical made by the immune system to destroy foreign invaders.

General autoimmune disorder:

An autoimmune disorder that involves a number of tissues throughout the body.

Immune system:

A network of organs, tissues, cells, and chemicals designed to fight off foreign invaders, such as bacteria and viruses.

Organ specific disorder:

An autoimmune disorder in which only one type of organ is affected.

Steroids:

A group of naturally occurring substances that are very effective in reducing pain and swelling in tissues.

An organ transplantation may be necessary when a person's heart, kidney, lungs, liver, or some other vital organ becomes diseased. In such cases, a second person may offer to donate his or her organ to replace the diseased or damaged organ. Autoimmune disorders can often occur when organs are transplanted from one person to another. The problem is that the patient's immune system may reject the donated organ because it thinks the donated organ is a foreign body. It begins to attack the new organ as it would bacteria, viruses, fungi, or other disease-causing organisms.

Patients who receive transplanted organs are also given immunosuppressant drugs. An immunosuppressant drug is a chemical that reduces the body's natural defenses against foreign bodies. It gives the donated organ a chance to become implanted in the new body and start functioning again.

However, immunosuppressant drugs can cause a different set of problems: they prevent the immune system from doing its normal jobs; a patient becomes much more sensitive to diseases that the immune system is usually able to fight; and patients may become ill very easily. For most patients, though, the tradeoff is well worth it. Without the new, healthy organ and the immunosuppressant drugs to sustain it, they might not live.