Autoantibodies are a group of antibodies (immune proteins) that mistakenly target and damage specific tissues or organs of the body. One or more autoantibodies may be produced by a person's immune system when it fails to distinguish between "self" and "non-self" proteins. Usually the immune system is able to discriminate by recognising foreign substances (non-self) and ignoring the body's own cells (self), yet not overreact to non-threatening substances such as foods, dust and pollen, or beneficial microorganisms. It creates antibodies only when it perceives what it has been exposed to as a threat (non-self). When the immune system ceases to recognise one or more of the body's normal constituents as "self", it may produce autoantibodies that attack its own cells, tissues, and/or organs, causing inflammation and damage. The causes of this inappropriate action are varied and are not well understood, often resulting in a chronic auto-immune disorder. While there is not a direct link, it is thought that many cases of autoantibody production are due to a genetic predisposition combined with an environmental trigger (such as a viral illness or a prolonged exposure to certain toxic chemicals). Some families have been shown to have a high prevalence of auto-immune conditions; however, individual family members may have different auto-immune disorders or may never develop an auto-immune condition. Researchers believe that there may also be a hormonal component to the cause as many of the auto-immune conditions are more common in women of childbearing age. This book presents leading research from throughout the world.