Resumen

FALFAN VALENCIA, RAMCÉS. MHC: POLIMORFISMOS GENÉTICOS EN AUTOINMUNIDAD. Rev. Inst. Nal. Enf. Resp. Mex. [online]. 2004, vol.17, n.2, pp.126-134. ISSN 0187-7585.

Autoimmune diseases are characterized by inflammation and by the development and maintenance of antibodies and T lymphocytes against "self" antigens. Although the etiology of these diseases is unknown, they have a number of cellular and molecular mechanisms in common. A strong genetic association exists between a number of autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, and insulin-dependent diabetes mellitus (IDDM) and the expression of certain alleles or haplotypes of the major histocompatibility complex (MHC). The current explanation for this association proposes that disease-associated MHC molecules efficiently bind autoantigens involved in the pathophysiology of the disease. This results in a peripheral T cell-mediated immune response to the autoantigens and autoimmune sequelae. Individual susceptibility to autoimmune diseases may be determined by a combination of specific polymorphisms of genes encoding multiple cytokines, MHC antigens, adhesion molecules, and cellular proteins. This condition may lead to abnormal expression of immunoregulatory molecules and finally result in the development or exacerbation of the disease. Recently, the role of viral sequences in the pathogenesis of autoimmunity has been discussed, mainly involved in molecular mimicry.

Palabras llave : Autoimmunity; MHC; HLA; HLA-DR; HLA-DQ; insulin-dependent diabetes mellitus; autoimmune disease.