A comprehensive reference work: This looseleaf work is an authoritative compilation of methods for the detection of autoantibodies (Section A: Methods of Autoantibody Detection); the structure, function, and molecular and biochemical concepts of autoantigens (Section B: Autoantigens); and the clinical significance of measuring autoantibodies in patients with rheumatic, connective tissue and autoimmune diseases (Section C: Clinical Significance of Autoantibodies). This unique work brings together all the molecular and medical information - very difficult to retrieve otherwise - in ONE publication. The Editors and contributors are leading experts in the immunological, molecular biological, and clinical fields. The format of this looseleaf publication allows regular updating of data as well as inclusion of new advances in research on autoimmunity. Until now, the work (Basic work including Supplement 1) included Section A, and the larger part of Section B, both in an attractive and robust ringbinder. Audience: By nature and design of this exciting reference work, it is especially aimed at scientists, including immunologists, pathologists and molecular biologists, and clinical chemists, as well as clinicians specializing in rheumatic diseases and autoimmune disorders, inflammation or clinical immunology. Supplement 2: This supplement primarily contains Section C (Clinical Significance of Autoantibodies). As in the other sections, the contents are presented in a consistently structured manner, beautifully illustrated with photos and schematic figures. Extensive literature references are provided. Also, this supplement includes an addition to Section B (Autoantigens), being chapter B.1.5: The Antigens Defined by Antikeratin Antibodies (AKA).