Recent Observations on the Experimental Pathogenesis of Multiple Sclerosis

Multiple sclerosis is a disease with complex immune system interactions that are being painstakingly elucidated by various means of experimentation. Great effort is being put forth to discover disease processes that may be affected by immunomodulatory therapies. Difficulties of experimentation and the ability to compare separate experiments in the same context notwithstanding, results from various experiments are being collated and many logical disease mechanisms are being proposed. This paper is an overview of new experimental observations made in the context of previous science and presents a perspective on the ability to compare experimental results from various contexts. Introduction Multiple sclerosis (MS) is a chronic, demyelinating disease of the central nervous system white matter that may cause paralysis, sensory disturbances, incoordination, visual impairment, and alterations in bowel and bladder function. The precise etiology of MS has not been elucidated; however, many observations have been made in both human MS patients and in animal models of the disease, and these observations suggest that both genetic susceptibility and environmental factors play a role in the etiology of MS.1 Some features of the disease suggest that it shares characteristics of other autoimmune disorders2 whereby dysfunction of the local immune system is associated with a local inflammatory reaction. The pathological lesion of MS involves demyelination of central nervous system (CNS) axons and/or injury to either oligodendrocytes or axons, associated with inflammation that surrounds venules of the CNS and extends into the myelin sheath. This demyelination and associated axonal injury causes the clinical features of MS. The intensive and progressive experimental study of MS has elucidated many key observations in the pathogenesis of the disease. This paper is a review of both recent and historical observations of the pathogenesis of MS and it attempts to orga-