SEASONAL-VARIATION OF INTERFERON-GAMMA PRODUCTION IN PROGRESSIVE MULTIPLE-SCLEROSIS

Multiple sclerosis (MS) is a chronic inflammatory disease of the centr al nervous system. There is increased interferon (IFN)-gamma secretion in MS patients in vitro, and IFN-gamma administration induces exacerb ations of disease suggesting a link between IFN-gamma and disease acti vity. We observed significantly increased IFN-gamma production in the autumn and winter months compared with the spring and summer months in chronic progressive MS, and this increase was linked to endogenous in terleukin (IL)-12 production. Increased seasonal IFN-gamma was not obs erved in normal control subjects, and there were no seasonal changes i n IL-10 in progressive MS. These results suggest a potential environme ntal link between dysregulated IFN-gamma production and MS disease pro gression and pathogenesis.