Multiple sclerosis (MS) is a disabling neurological disease with still unknown causes. In addition to a yet unspecified genetic component, there is compelling evidence for the existence of one or more exogenous factors. To study the importance of such exo genous factors a large-scale international case-control study on MS is initiated. The cases in this study will be recruited from existing patient registries that cover large areas and controls will be drawn from the general population of the corresponding areas. Data on possible risk factors will be collected using self-administered questionnaires and will include a limited set of factors related to current hypotheses.
The applicant is the primary investigator of this study and is in relation to the st udy invited to a one year stay at Harvard School of Public Health, in Boston. The host is Alberto Ascherio who is an active member of the study group.
Ascherio is probably the leading international researcher on etiological studies of environmental risk factors in MS, and he has recently published results from cohort studies showing that Epstein-Barr virus, smoking and low vitamin D-status are highly probable risk factors in MS. The focus of the case-control study will be a further examination of these currently most attractive etiological hypotheses. The specific aim is to study the presence and combination of these risk factors, of which the two latter are potentially modifiable either through education or specific interventions at the population leve l (e.g. vitamin D supplementation trial). The study is estimated to include more that 3000 patients and 12000 controls.
The research stay at Harvard will enable a state of the art analysis of the data from the case-control study. Beyond the work on this study, the applicant will continue previously established collaboration with Ascherio that involves work on two Norwegian cohorts ("HUSK -study" and "Mother and child") including a study on smoking.