Season of infectious mononucleosis and risk of multiple sclerosis at different latitudes; the EnvIMS Study
2014 (English)In: Multiple Sclerosis, ISSN 1352-4585, E-ISSN 1477-0970, Vol. 20, no 6, 669-674 p.Article in journal (Refereed) Published
Background: Seasonal fluctuations in solar radiation and vitamin D levels could modulate the immune response against Epstein-Barr virus (EBV) infection and influence the subsequent risk of multiple sclerosis (MS). Methods: Altogether 1660 MS patients and 3050 controls from Norway and Italy participating in the multinational case-control study of Environmental Factors In Multiple Sclerosis (EnvIMS) reported season of past infectious mononucleosis (IM). Results: IM was generally reported more frequently in Norway (p=0.002), but was associated with MS to a similar degree in Norway (odds ratio (OR) 2.12, 95% confidence interval (CI) 1.64-2.73) and Italy (OR 1.72, 95% CI 1.17-2.52). For all participants, there was a higher reported frequency of IM during spring compared to fall (pless than0.0005). Stratified by season of IM, the ORs for MS were 1.58 in spring (95% CI 1.08-2.31), 2.26 in summer (95% CI 1.46-3.51), 2.86 in fall (95% CI 1.69-4.85) and 2.30 in winter (95% CI 1.45-3.66). Conclusions: IM is associated with MS independently of season, and the association is not stronger for IM during spring, when vitamin D levels reach nadir. The distribution of IM may point towards a correlation with solar radiation or other factors with a similar latitudinal and seasonal variation.
Place, publisher, year, edition, pages
SAGE Publications (UK and US) , 2014. Vol. 20, no 6, 669-674 p.
vitamin D; Epstein-Barr virus; latitude; interaction; Multiple sclerosis; seasons
IdentifiersURN: urn:nbn:se:liu:diva-106843DOI: 10.1177/1352458513505693ISI: 000334865900005OAI: oai:DiVA.org:liu-106843DiVA: diva2:720132