%0 Journal Article
%T The autoimmune tautology
%A Juan-Manuel Anaya
%J Arthritis Research & Therapy
%D 2010
%I BioMed Central
%R 10.1186/ar3175
%X Autoimmune diseases are chronic conditions initiated by the loss of immunological tolerance to self-antigens and represent a heterogeneous group of disorders that afflict specific target organs or multiple organ systems. The chronic nature of these diseases places a significant burden on the utilization of medical care, direct and indirect economic costs, and quality of life. Almost all autoimmune diseases disproportionately affect middle-aged women and are among the leading causes of death for this group of patients. With increasing age of patients, the female-to-male ratio for autoimmune diseases becomes more prominent.The autoimmune tautology refers to the fact that autoimmune diseases share several clinical signs and symptoms, physiopathologic mechanisms, and genetic factors and this fact indicates that they have a common origin (Table 1). In the previous issue of Arthritis Research & Therapy, Eyre and colleagues [1] report that variation within the TAGAP gene, at 6q25.3, is associated with three autoimmune diseases, namely rheumatoid arthritis, type 1 diabetes, and coeliac disease, in Caucasians. In addition, the authors confirmed other loci associated with these diseases in their population: CTLA-4, the IL2-21 region, 6q23 (TNFAIP3), SH2B3, PRKCQ, and MMEL1 [1].The impact of genetic predisposition on susceptibility to autoimmune diseases was first identified by the analysis of disease concordance rates in monozygotic twins (concordance rates ranged from about 15% to 57%) [2]. The decrease in the concordance rates of siblings compared with the rate among monozygotic twins supports the presence of multiple genes contributing to the autoimmune phenotype onset.A primary characteristic of complex diseases is that affected individuals tend to cluster in families (that is, familial aggregation, also referred to as recurrence risk). Recurrent associations of autoimmune diseases in family members of patients have been reported. Although non-genetic factors may have an
%U http://arthritis-research.com/content/12/6/147