Updated September 12, 2007
Lupus (also known as SLE, systemic lupus erythematosus) is an autoimmune disease. It takes on several forms and can affect any part of the body, but is most commonly attacks the skin, joints, heart, lungs, blood, kidneys and brain.
Autoimmune diseases are characterized by a malfunction of the immune system –- one in which the immune system cannot distinguish between the body's own cells and tissues and foreign matter, like viruses. Rather than simply producing antibodies to attack antigens (viruses, bacteria and similar foreign matter), the immune system creates auto-antibodies that attack the immune system itself.
©2014 About.com. All rights reserved.