Multiple sclerosis and experimental autoimmune encephalomyelitis: A review

Abstract

Multiple sclerosis is a chronic inflammatory autoimmune disease of the central nervous system, characterized by mononuclear cell infiltration, axon demyelination and gliosis in the myelin sheath, with formation of multiple plaques. It affects individuals aged between 25 and 50 years old, female and residents of higher latitudes. The etiology of multiple sclerosis is multifactorial and not fully understood; however, the influence of genetic predisposition and environmental factors on immune dysregulation is recognized. The pathophysiology of the disease is mediated by self-reactive T lymphocytes that respond to autoantigens from the central nervous system. The emergence of multifocal regions of demyelination, axonal loss, loss of oligodendrocytes and astroglial scarring result in impaired neurological function, leading to neurodegeneration. Although there is still no cure for multiple sclerosis, scientific research has provided great advances in therapeutic strategies. Currently there are approaches to attenuate specific signs and symptoms, drugs to control disease relapses and treatments designed to modify or delay the course of multiple sclerosis. Although these drugs show promising effects, they are ineffective in curing the patient. In addition, they present a fundamental problem, which is the non-selective action on the cells of the immune system, which triggers serious side effects. Considering the limitations of studies in humans due to the difficulty of accessing the affected tissues, the use of experimental models that simulate the singularities of multiple sclerosis is a key element for the study of the pathogenesis of inflammation and therapeutic alternatives. Experimental autoimmune encephalomyelitis, an animal model that presents several similarities with pathophysiological, histological and clinical aspects of multiple sclerosis, is the most used model for these studies. Therefore, in this chapter, the aim was to review the historical context, definition, etiology, pathophysiology, clinical manifestations, diagnosis and treatment of multiple sclerosis and, at the same time, address aspects of the timeline, induction, the evolutionary course and the immunopathogenesis of the most studied model for the investigation of the nuances of multiple sclerosis, correlating the similarities and differences between both.