The book series "Autoantigens, Autoantibodies, Autoimmunity" is designed to provide clinicians and scientists with reviews and new results on a broad range of topics in autoimmunology which are relevant to the etiology, pathology, diagnosis and therapy of autoimmune diseases. The first issue summarizes the results on the 5th Dresden Symposium on Autoantibodies, held in Dresden on October 18-21, 2000. The main aspects of this symposium are addressed to autoantigens and autoantibodies as clues to understanding autoimmunity and their use as diagnostic tools. The research on genomics and proteomics leads to growing insights into the structure and function of autoantigens as well as into processes of the induction, diversification and pathogenic effects of autoimmune responses (Chapter 1 - 4). In addition, more and more autoantigens and autoantibodies of potential diagnostic or pathogenic relevance were identified (Chapter 1, 2, 5). A better understanding of the mechanisms of induction, maintenance and effects of pathogenic autoimmunity is a prerequisite for improvements of prophylaxis, diagnosis and therapy not only of definite systemic (Chapter 6, 7, 10) or organ specific autoimmune diseases (Chapter 8, 9, 11, 12) but also for diseases with suspected pathogenic autoimmunity such as preeclampsia and HELP syndrome (Chapter 4), atherosclerosis (Chapter 6), paraneoplastic diseases (Chapter 11) and chronic urticaria (Chapter 12). One common thread uniting autoimmune diseases is the presence of disease specific autoimmune responses. These responses are often detectable a long time before a definite diagnosis of the autoimmune disorder can be made. The continuous development in serological testing for autoantibodies is directly attributable to the rapid growth of molecular biology. A growing number of test kits for diagnostic and predictive marker antibodies become available for routine laboratory practice. Nevertheless, there is a need for further optimization and standardization of assays for the determination of autoantibodies (Chapter 13).