The role of female sex hormones in multiple sclerosis and its animal models
Kaja Śmietanka, Bartosz Bielecki
Multiple sclerosis is a progressive disease of the central nervous system with a complex immunopathogenesis characterised by inflammation, demyelination and progressive loss of axons. In the studies on the complex and multifactorial pathophysiology of multiple sclerosis, an animal model of the experimental autoimmune encephalomyelitis plays an important role. Clinical and experimental data suggest autoimmune background of inflammatory responses in the central nervous system. Unfortunately, the pathology of multiple sclerosis is still not fully understood, and the currently available drugs are only able to inhibit the progression of the neurological deficits. Epidemiological data clearly show that gender significantly affects the incidence and course of multiple sclerosis. In both clinical and experimental studies, pregnancy and hormonal treatment with female sex hormones have been shown to influence the number of relapses and the progression of neurological deficits. Abundant data suggesting the role of both sex and pregnancy in multiple sclerosis gave rise to research on the role of sex hormones in this disease and new forms of treatment. In this paper, we have reviewed the available literature regarding the effects of female sex hormones on the course of multiple sclerosis, with particular emphasis on the role of estrogens and progestagens. Data from both clinical and experimental studies have been included. Estrogens and progestagens are the two most important groups of female steroid hormones. They are necessary for development of sex organs as well as for fertility and during pregnancy. It is known that these hormones are able to modulate the function of the immune system. In this review, we have focused not only on the immunomodulatory, but also on the neuroprotective and neuroregenerative role of estrogens and progestagens. We have also described the new therapeutic possibilities associated with the hormonal therapy targeting sex hormones.