Neuroimmunologic Mechanisms in the Etiology of Multiple Sclerosis

Multiple sclerosis (MS) is a common chronic inflammatory demyelinating disorder of the central nervous system (CNS) (1,2) that is heterogeneous with respect to its clinical course, response to therapy, radiology, structural pathology, and immunopathogenesis. The factors that contribute to this heterogeneity are largely unknown, although it is likely a complex trait with genetic and environmental components. MS is a disease of young people with a median age of onset of 28 yr, and affects approx 0.1% of the population in temperate climates. The disorder is the most common cause of nontraumatic disability in young adults, with 50% of patients requiring a cane to walk 15 yr after disease onset (3).