Past sun exposure, skin phenotype and risk of multiple sclerosis: A case-control study

Abstract

The striking latitudinal gradient of multiple sclerosis (MS) prevalence may reflect variation in ultraviolet radiation (UVR). A Th1 cell mediated attack on myelin proteins appears to be important in the pathogenesis of MS and recent immunological work shows that UVR can suppress the Th1 cell mediated activity. We conducted a population based case-control study in Tasmania, Australia, to examine whether high past sun exposure was associated with a reduced risk of MS. Interviews were conducted with 136 cases with MS and 272 controls randomly drawn from the community and matched on sex and birth year. Measures included reported sun exposure, dermal actinic damage (a marker of cumulative lifetim..