Molecular mimicry in human diseases--phenomena or epiphenomena?

Molecular mimicry is one mechanism by which infectious agents (or other exogenous substances) trigger an immune response against the host antigens. When a susceptible host acquires an infection with an organism that has antigens immunologically similar to the host antigens but differ sufficiently, to induce, an immune response when presented to T cells, results in loss of tolerance to host antigens. Further more there is development of a pathogen-specific immune response that cross-reacts with host structures to cause tissue damage and disease. Till date the advances in the research in molecular biology has documented evidence to suggest that molecular mimicry plays in important role in pathogenesis of a number of diseases. This review is a brief overview of some of these disorders.