Recent advances in the treatment of multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory, immune-mediated, demyelinating, neurodegenerative disorder of the central nervous system. Despite the lack of an etiologic factor, it has been consistently demonstrated that the immune system plays a crucial role in the pathogenesis of MS. The traditional description of immunopathogenesis of MS suggests a preferential CD4+ TH1 cell activity causing tissue damage by the release of pro-inflammatory cytokines and subsequent demyelination and axonal loss. Recent evidence, however, suggests that other immune cells including TH17 cells, CD8+ effector T cells, CD4+ CD25+ regulatory T cells, and B cells may play a prominent role in MS immunopathology. A better understanding of the molecular and cellular components of the immunopathogenesis of MS is allowing the development of novel therapies.