[Evolution of the concept of autoimmunity and its therapeutic implications]

Autoimmunity is paradoxically a physiologic phenomenon. One finds in normal sera natural autoantibodies that are encoded by germ line genes. Autoimmunity is at the origin of common and severe diseases such as diabetes mellitus, rheumatoid arthritis, systemic lupus erythematosus and perhaps psoriasis and Crohn's disease. The disease may be due according to cases to exacerbation of physiologic autoimmunity or to appearance of autoreactive clones producing autoantibodies encoded by mutated genes. The respective role of triggering environmental factors and genetic predisposition (HLA and non HLA genes) is not determined. New immunotherapeutic methods, particularly cyclosporine, monoclonal antibodies (against T cells, CD4 and T cell receptor molecules and Ia antigens) and autoantigen-specific vaccination open new major therapeutic perspectives that presage major improvement in the prognosis of these diseases.