Gender differences in the histopathology of MS?

Multiple sclerosis (MS) lesions are histopathologically characterized by inflammation, demyelination/remyelination, axonal damage and gliosis. Animal experimental and in vitro studies suggest that sex hormones influence the immune system and contribute to the increased likelihood in women of developing MS. However, a variety of studies have also shown that remyelination is more marked in female rodents or that female sex hormones are beneficial for myelin repair. To determine whether gender influences the histopathology of MS lesions, we compared the extent of inflammation, axonal damage and remyelination in MS lesions of female and male MS patients. We observed no differences in the composition of inflammatory infiltrates, axonal damage or cortical pathology. Similar numbers of oligodendroglial progenitor cells and mature oligodendrocytes were present in MS lesions. Remyelination is slightly, but not significantly, more extensive in women than men in early MS lesions. The absence of significant differences in lesion pathology between female and male MS patients might be explained by a lack of a gender influence, but also might be due to the limited number of tissue samples available for histopathological analysis.