| 1. |
- Salzer, Jonatan, 1981-, et al.
(författare)
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Epstein-Barr virus antibodies and vitamin D in prospective multiple sclerosis biobank sampels
- 2013
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Ingår i: Multiple Sclerosis Journal. - : Sage Publications. - 1352-4585 .- 1477-0970. ; 19:12, s. 1587-1591
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Tidskriftsartikel (refereegranskat)abstract
- Background: Increased antibody reactivity against Epstein-Barr Nuclear Antigen-1 (EBNA-1) has been associated with an increased risk for MS, and high levels of 25-Hydroxyvitamin D (25[OH]D) have been associated with a lower risk for MS. Interaction between these two factors has been proposed.Objectives: To examine the association between antibody reactivity against EBNA-1 and five EBNA-1 domains, and the risk for multiple sclerosis (MS), and to examine if these antibodies and 25(OH)D status interact regarding MS risk in prospectively collected blood samples.Methods: Antibody reactivity (as specified above) and 25(OH)D levels were measured using ELISAs in n=192 MS cases and n=384 matched controls. The risk for MS was analysed using matched logistic regression.Results: The risk for MS increased across tertiles of antibody reactivity against EBNA-1, domain EBNA-1402–502, and domain EBNA-1385–420; p trend <0.001. The risk increase was most pronounced for EBNA-1385–420. In young individuals (below median age at sampling, <26.4 years) these associations were stronger, and 25(OH)D levels correlated inversely to antibody reactivity against EBNA-1 and the EBNA-1 domains.Conclusions: We confirm that increased antibody reactivity against EBNA-1 is a risk factor for MS. Our findings in young individuals suggest that 25(OH)D status might influence the immune response towards Epstein-Barr virus, and thereby modulate MS risk.
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| 2. |
- Salzer, Jonatan, 1981-, et al.
(författare)
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Smoking as a risk factor for multiple sclerosis
- 2013
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Ingår i: Multiple Sclerosis Journal. - : Sage Publications. - 1352-4585 .- 1477-0970. ; 19:8, s. 1022-1027
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Tidskriftsartikel (refereegranskat)abstract
- Background: Smoking has been associated with an increased risk for multiple sclerosis, but no studies have measured levels of the nicotine metabolite cotinine in prospectively collected samples to assess exposure.Objective: To investigate the effects of laboratory defined tobacco use on the risk for multiple sclerosis using prospectively collected biobank blood samples.Methods: Levels of cotinine were measured in n=192 cases, and n=384 matched controls, using an immunoassay. The risk for multiple sclerosis was estimated using matched logistic regression.Results: Elevated cotinine levels (≥10 ng/ml) were associated with a significantly increased risk for multiple sclerosis, (odds ratio, OR 1.5, 95% confidence interval, CI 1.0–2.1). This association was only present in young individuals (below median age at blood sampling, <26.4 years), (OR 2.2, 95% CI 1.3–3.8).Conclusions: This study confirms that smoking is a risk factor for multiple sclerosis. It has the advantage of using analyses of cotinine levels in samples that were collected several years before disease onset, thus excluding any risk for recall bias and minimising the risk for reversed causation. Our results also suggest that the smoking related immunological events that contribute to the development of multiple sclerosis occur early in life.
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| 3. |
- Salzer, Jonatan, 1981-, et al.
(författare)
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Vitamin A and systemic inflammation as protective factors in multiple sclerosis
- 2013
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Ingår i: Multiple Sclerosis Journal. - : Sage Publications. - 1352-4585 .- 1477-0970. ; 19:8, s. 1046-1051
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Tidskriftsartikel (refereegranskat)abstract
- Background: Vitamin A is important for the immune system, and might suppress inflammatory activity in multiple sclerosis (MS).Objectives: We aimed to examine if vitamin A levels were associated with MS risk in samples collected prospectively and during gestation.Methods: We measured Retinol Binding Protein (RBP – a surrogate marker for vitamin A) and high-sensitivity C-reactive protein (hs-CRP) levels, in (1) prospectively collected biobank blood samples from MS cases and controls, and (2) gestational samples where the offspring had later developed MS, and gestational control samples. The risk of MS was calculated using matched multivariable logistic regression adjusted for confounders.Results: In prospective samples, RBP levels within the second quintile (vs. the first) were associated with a lower MS risk (OR = 0.38, 95% CI 0.19–0.74). No effect on MS risk in the offspring by gestational RBP levels was found. In young subjects hs-CRP levels ≥10 mg/l in prospective samples were associated with a lower MS risk (OR = 0.36, 95% CI 0.14–0.95).Conclusions: Our results suggest that sub-optimal vitamin A levels may be associated with MS risk. The association between hs-CRP levels and MS risk in young subjects may support the role of the hygiene hypothesis in MS aetiology.
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| 4. |
- Salzer, Jonatan, et al.
(författare)
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Vitamin D as a protective factor in multiple sclerosis
- 2012
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Ingår i: Neurology. - 0028-3878 .- 1526-632X. ; 79:21, s. 2140-2145
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To examine the association between 25-hydroxyvitamin D (25[OH]D) levels and the risk of multiple sclerosis (MS) in blood samples collected prospectively and during gestation.Methods: In this nested case-control study, 2 population-based biobanks with 291,500 samples from164,000 persons collected since 1975 in the northern half of Sweden were used. We identified prospectively collected blood samples from MS cases (n = 192, controls matched 2:1) and gestational samples from pregnant mothers where the offspring had later developed MS (n = 37, control mothers matched 5:1). 25(OH)D levels were measured using an ELISA, and the risk of MS was analyzed using matched logistic regression.Results: Levels of 25(OH)D ≥75 (vs <75) nmol/L in prospectively collected blood samples were associated with a decreased risk of MS (odds ratio [OR] 0.39, 95% confidence interval [CI] 0.16- 0.98). No decrease in MS risk was found in the offspring exposed to gestational 25(OH)D levels ≥75 (vs <75) nmol/L (OR 1.8, 95%CI 0.53-5.8). The prevalence of 25(OH)D levels ≥75 nmol/L in female controls decreased gradually during 1976-2005 (p trend = 0.005).Conclusion: This study supports the presence of an association between high 25(OH)D levels during the years preceding disease onset and a decreased risk of MS. In the very limited material with samples drawn in early pregnancy, where month-of-birth effects were controlled for, we found no association between gestational 25(OH)D levels and MS risk in the offspring. Decreasing 25(OH) D levels in the population may contribute to explain the increasing MS incidence that is suggested from epidemiologic studies.
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