The initiation and prevention of multiple sclerosis.
ABSTRACT Although strong genetic determinants of multiple sclerosis (MS) exist, the findings of migration studies support a role for environmental factors in this disease. Through rigorous epidemiological investigation, Epstein-Barr virus infection, vitamin D nutrition and cigarette smoking have been identified as likely causal factors in MS. In this Review, the strength of this evidence is discussed, as well as the potential biological mechanisms underlying the associations between MS and environmental, lifestyle and dietary factors. Both vitamin D nutrition and cigarette smoking are modifiable; as such, increasing vitamin D levels and smoking avoidance have the potential to substantially reduce MS risk and influence disease progression. Improving our understanding of the environmental factors involved in MS will lead to new and more-effective approaches to prevent this disease.
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ABSTRACT: Objective Some previous studies suggest modest to strong effects of 25-hydroxyvitamin D (25(OH)D) on multiple sclerosis (MS) activity. The objective of this study was to explore the mechanistic rationale that may explain potential clinical effects of 25(OH)D.Methods This study measured serum 25(OH)D levels and global gene expression profiles over a course of up to 2 years in patients starting treatment with interferon beta-1b (IFNB-1b) after a clinically isolated syndrome. MS disease activity was assessed by the number of gadolinium-enhancing lesions present on repeated magnetic resonance imaging (MRIs).ResultsThe number of gadolinium-enhancing lesions was highly significantly associated with 25(OH)D levels. Conducting various systems-level analyses on the molecular level, multiple lines of evidence indicated that 25(OH)D regulates expression dynamics of a large gene–gene interaction system which primarily regulates immune modulatory processes modulating MS activity. The vitamin D response element was significantly enriched in this system, indicating a direct regulation of this gene interaction network through the vitamin D receptor. With increasing 25(OH)D levels, resulting regulation of this system was associated with a decrease in MS activity. Within the complex network of genes that are regulated by 25(OH)D, well-described targets of IFNB-1b and a regulator of sphingosine-1-phosphate bioavailability were found. The 25(OH)D effects on MS activity were additively enhanced by IFNB-1b.InterpretationHere, we provide mechanistic evidence that an unbalanced 25(OH)D gene expression system may affect MS activity. Our findings support a potential benefit of monitoring and managing vitamin D levels (e.g., through supplementation) in early MS patients treated with IFN-beta-1b.Annals of Clinical and Translational Neurology. 08/2014;
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ABSTRACT: Background Several environmental exposures, including infection with Epstein-Barr virus, low levels of vitamin D and smoking are established risk factors for multiple sclerosis (MS). Also, high hygienic standard and infection with parasites have been proposed to influence MS risk. The aim of this study was to investigate the influence of various environmental exposures on MS risk in a Norwegian cohort, focusing on factors during childhood related to the hygiene hypothesis.MethodsA questionnaire concerning environmental exposures, lifestyle, demographics and comorbidity was administrated to 756 Norwegian MS patients and 1090 healthy controls. Logistic regression was used to calculate odds ratio (OR) with 95% confidence interval (CI) for the risk of MS associated with the variables infectious mononucleosis, severe infection during childhood, vaccination and animals in the household during childhood. Age, gender, HLA-DRB1*15:01, smoking and infectious mononucleosis were included as covariates. General environmental exposures, including tobacco use, were also evaluated.ResultsInfectious mononucleosis was confirmed to be significantly associated with increased MS risk, also after adjusting for the covariates (OR¿=¿1.79, 95% CI: 1.12-2.87, p¿=¿0.016). The controls more often reported growing up with a cat and/or a dog in the household, and this was significant for ownership of cat also after adjusting for the covariates (OR¿=¿0.56, 95% CI: 0.40-0.78, p¿=¿0.001). More patients than controls reported smoking and fewer patients reported snuff use.Conclusions In this Norwegian MS case¿control study of environmental exposures, we replicate that infectious mononucleosis and smoking are associated with increased MS risk. Our data also indicate a protective effect on MS of exposure to cats during childhood, in accordance with the hypothesis that risk of autoimmune diseases like MS may increase with high hygienic standard.BMC Neurology 10/2014; 14(1):196. · 2.49 Impact Factor
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ABSTRACT: Prolactin (PRL) is a pleiotropic hormone; in addition to a wide variety of endocrine effects, PRL also exhibits immunostimulating effects. Therefore, there is increasing evidence linking PRL with a large number of systemic and organ specific autoimmune diseases. Herein, we report the case of an adolescent girl diagnosed with multiple sclerosis (MS) occurring in the context of untreated prolactinoma evolving since childhood. This raises the exciting question of the involvement of PRL in the pathogenesis of MS. It is likely that early treatment of hyperprolactinemia in this case would have significantly reduced the risk of developing MS or even prevented its occurrence.Cellular Immunology 11/2014; · 1.87 Impact Factor