The Multiple Autoimmune Syndromes

Abstract

The common background evidence for autoimmune diseases has grown and allows us to infer that although their heterogeneity is due to a collection of diverse disorders based on epidemiology, pathology, or diagnostic criteria, in fact the underlying immunogenetic mechanism might be similar. The clinical evidence supporting the common origin of autoimmune diseases corresponds to the kaleidoscope of autoimmunity, which is the co-occurrence of various autoimmune diseases within an individual or co-occurrence within members of a family. The two better conditions that illustrate the kaleidoscope of autoimmunity are the multiple autoimmune syndromes (MAS) and the familial autoimmunity (FA). The MAS consists in the presence of three or more well-defined autoimmune conditions in a single patient. A review of the literature and cluster analysis of MAS disclosed systemic lupus erythematosus, Sjögren’s syndrome, and autoimmune thyroid disease as the “chaperones” of autoimmune diseases. FA is defined as the presence of diverse autoimmune diseases on multiple members of a nuclear family. In this chapter, both the MAS and FA are discussed and illustrated in the context of the common genetic background of autoimmunity.