Hormones sexuelles et sclérose en plaques

Multiple sclerosis is an autoimmune inflammatory demyelinating disease which preferentially affects young women while occuring at a somewhat later age and with more severity in men. Genetic but also hormonal influences may account for this gender difference observed in humans and in the animal model of the disease: experimental autoimmune encephalomyelitis. Through their immune, promyelinating and neuroprotective properties, estrogens, progesterone and androgens are able to influence the course of the disease. It is now well established that the relapse rate is inhibited in the late pregnancy and increases during the first quarter after delivery. In animal models, various estrogens, progesterone and androgens can prevent or attenuate the disease, while castration of males enhances its severity. Clinical and experimental data have led to consider sexual steroids as potential adjuvant therapeutic tools. Two pilot studies have been conducted with oral estriol in women and percutaneous testosterone in men. A phase III clinical trial, POPART'MUS, aimed at preventing postpartum relapses with an estradiol-progestin association, is still running.