Allergy & Immunology

Autoimmune & Inflammatory Diseases

The immune system has the capacity to mount an immune response to virtually all molecules and/or cells. Although the capacity to respond to self-antigen is present in all of us, in most instances such responses result in tolerance, indicating that mechanisms must exist to prevent or subdue autoimmune responses. Moreover, auto-reactive T and B cells, as well as autoantibodies, are found in people who do not have autoimmune diseases, demonstrating that immunological auto-reactivity alone is not sufficient for the development of the disease. The mechanisms currently thought to prevent/dampen autoimmune responses include inactivation or deletion of autoreactive B and T cells, active suppression by cells or cytokines, idiotype or anti-idiotype interactions, and the immunosuppressive adrenal hormones, the glucocorticoids. When dampening mechanisms fail or are overridden, a response directed against self-antigen can occur, resulting in autoimmune diseases that range from those which are organ-specific (diabetes and thyroiditis) to those which are systemic (non-organ specific) such as systemic lupus erythematosus and rheumatoid arthritis.