Introduction

This is the introductory chapter to the section Organ-Localized Autoimmune Diseases . Autoimmunity is common, while autoimmune disease is not. Autoimmune disease can be divided into two types. The first type - the systemic diseases - are conditions in which the whole body may be involved. The second category consists of the organ-specific autoimmunities. More and more of the assays are now based on enzyme-linked immunosorbent assay using purified antigens or recombinant antigens. Certain new assays use immunoblots of tissue extracts or digested purified antigens. These assays have promise for screening several antigens or epitopes simultaneously. The role of the clinical laboratory is changing from one in which new assays are developed to one of evaluating the new technologies.