Janet – The antibodies of Grave’s disease attack the thyroid and cause it to release too much thyroid – these are pretty specific for the thyroid. There may be some cross-over with the eye disease that accompanies Graves. There are no other organs I know of that are impacted. The reason of the antibodies is that the immune system has lost its ability to recognise the thyroid as "self" and attacks it as "non-self".
However, if someone has Graves, they have a greater risk of other autoimmune diseases, diabetes, lupus, etc. These are not the same antibodies. What we think causes the immune system to start recognise self as non-self has to do with the internal mechanism for eliminating self-antibodies is not working. So, it is possible for other self antibodies to occur in the same person – but the self-antibody for each illness is specific to that illness. Hope that helps. Cathy