The challenge resides in the complexity of the biochemical and cellular pathways involved in tolerance, which is the immune system's ability to distinguish self from non-self, allowing the body to recognize and destroy invading viruses, bacteria, and other pathogens while ignoring the body's own tissue and organs. Moreover, genetic and environmental influences that we don't fully understand multiply the complications of the pathways. The discovery and characterization of the regulatory pathways, however, will lead to new drugs and cell therapies for autoimmune diseases.2-4
More than 80 diseases with an autoimmune etiology have been identified. Clinicians divide autoimmune diseases into multiple categories based on systemic versus organ-specific autoimmunity, distinct roles of pathogenic antibodies versus pathogenic T cells, and complex mechanisms of action in the different disease settings. In some autoimmune diseases, an antibody acts against cell-surface or matrix antigens. This mechanism appears in Graves' disease, insulin-resistant diabetes, myasthenia gravis, pemphigus vulgaris, ...
