



The immune system is charged with identifying and destroying unwanted assailants. It is made up of a complex network of specialized cells and molecules that patrol the body seeking out intruders. In order to defend us, the immune system must be able to distinguish between self-tissues and foreign invaders. In healthy individuals, the immune system will mount responses to unfamiliar objects only, and ignore the body itself.
Sometimes this identification system breaks down, and the immune system mistakenly targets the body’s own tissues. This phenomenon is known as autoimmunity, and is observed in diseases like lupus, rheumatoid arthritis, myasthenia gravis, and multiple sclerosis.
A major weapon used by the immune system to protect the body is group of proteins called antibodies. Produced by highly specialized white blood cells, antibodies work by flagging unwanted invaders for destruction and removal.
In autoimmune disorders, antibodies are directed against various building blocks of the body like DNA or neurons. Self-directed antibodies are called ‘autoantibodies’, and are a major contributor to the destruction observed in autoimmune disorders.
During pregnancy, antibodies are passed from the mother to the developing fetus. These antibodies have a protective role, serving as a temporary immune system until the child’s own system matures during the first year of life.
If autoantibodies are present in maternal circulation, the fetus will receive them as well. Autoantibodies passed from the mother are capable of reacting with important proteins in the body of the developing fetus. In some autoimmune disorders, including lupus, rhematoid arthritis, myasthenia gravis and Grave's disease, autoantibodies produced by the mother can have a deleterious effect on the developing fetus.