[Role of autoimmunity in multiple sclerosis]

A number of evidences indicate that an antigen-specific immune reaction is responsible for the formation and/or the maintenance of multiple sclerosis (MS) lesions. This disease is characterized by the following: 1), an infiltration of the white matter of the brain and spinal cord by inflammatory cells; 2), the T and B lymphocytes, present in the lesions or in the cerebrospinal fluid of patients, show signs of activation; i.e., the classic IgG oligoclonal bands of the cerebrospinal fluid (activation of B lymphocytes) and the presence of activation markers on the surface of the T lymphocytes; 3), the presence of an association, and a linkage between the disease and the genes of the HLA complex. The HLA molecules are implicated in the presentation of the antigen to the T lymphocytes; 4), finally, it should be noted that the therapeutic approaches aimed at reducing (immunosuppressants) or at modulating (beta-interferon, copolymer 1) the immune responses have a positive effect on this disease, whereas those treatments which activate the immune system (gamma-interferon) have a negative effect.