Multiple sclerosis, vitamin D, and HLA-DRB1*15

Vitamin D levels in Hispanics with multiple sclerosis

Vitamin D has been associated with multiple sclerosis (MS) and several markers of disease state in whites. There are limited reports of vitamin D's influence in MS in ethnic groups, such as in Hispanics. In this study, we compared vitamin D levels in Hispanics and whites with MS and tried to determine whether season or increasing disability influence hypovitaminosis D in Hispanics with MS. Serum 25-hydroxyvitamin D [25(OH)D] levels and clinical characteristics were compared in a cross-sectional sample of Hispanics (n = 80) and whites (n = 80) with MS recruited from the University of Southern California. Serum 25(OH)D levels were significantly lower in Hispanics than whites with MS (mean and standard deviation 25.1 ± 9.4 and 37.3 ± 19.8 ng/ml, respectively; p < 0.001). Hispanics were significantly more likely than whites to be vitamin D insufficient (≤ 30 ng/ml; 70 vs. 41 %, respectively; p < 0.001) and deficient (≤ 20 ng/ml; 40 vs. 14 %, respectively, p < 0.001). In Hispanics, serum 25(OH)D levels were not influenced by season (p = 0.8) or higher physical disability (EDSS ≥ 6, p = 0.7). We found that the relationship between vitamin D and MS differs by Hispanic ethnicity. Hypovitaminosis D was significantly more common among Hispanics than among whites with MS, and the majority of Hispanics were vitamin D insufficient. Interestingly, there was no association between vitamin D levels and season or increasing disability in the Hispanics. Our findings imply that factors influencing vitamin D levels and possibly vitamin D requirements may vary by ethnicity in patients with MS. These results should be confirmed in larger, prospective multi-ethnic cohort studies.

ANKRD55 and DHCR7 are novel multiple sclerosis risk loci

Multiple sclerosis (MS) shares some risk genes with other disorders hallmarked by an autoimmune pathogenesis, most notably IL2RA and CLEC16A. We analyzed 10 single-nucleotide polymorphisms (SNPs) in nine risk genes, which recently emerged from a series of non-MS genome-wide association studies (GWAS), in a Spanish cohort comprising 2895 MS patients and 2942 controls. We identified two SNPs associated with MS. The first SNP, rs6859219, located in ANKRD55 (Chr5), was recently discovered in a meta-analysis of GWAS on rheumatoid arthritis (RA), and emerged from this study with genome-wide significance (odds ratio (OR) = 1.35; P = 2.3 × 10(-9)). The second SNP, rs12785878, is located near DHCR7 (Chr11), a genetic determinant of vitamin D insufficiency, and showed a size effect in MS similar to that recently observed in Type 1 diabetes (T1D; OR = 1.10; P = 0.009). ANKRD55 is a gene of unknown function, and is flanked proximally by the IL6ST-IL31RA gene cluster. However, rs6859219 did not show correlation with a series of haplotype-tagging SNPs covering IL6ST-IL31RA, analyzed in a subset of our dataset (D'< 0.31; r(2)< 0.011). Our results expand the number of risk genes shared between MS, RA and T1D.

Month of birth is associated with multiple sclerosis but not with HLA-DR15 in Finland

BACKGROUND

Spring birth has been found to be associated with increase in the risk of MS. However, this effect is reportedly found particularly in HLA-DR15 positive patients.

OBJECTIVE

Examine the month of birth (MOB) effect in Finnish MS patients and its association with HLA-DR15.

METHODS

Using the national register on hospitalizations during 1979-2004 we identified 8359 MS patients. We used a χ(2)-analysis to compare the distribution of MOB in MS patients versus age-adjusted controls. Patients were subdivided into 10-year birth cohorts to analyse temporal variations in MOB. A subgroup of HLA-typed MS patients (n = 657) and a population sample of healthy donors from the Finnish Bone Marrow Donor Registry (n = 19,805) were included to analyse connections between HLA-DR15 and MOB.

RESULTS

An April birth was associated with a 9.4% increased risk of MS (p = 0.008), whereas November birth was associated with an 11.1% decreased risk (p = 0.004) compared with the expected birth distribution. No temporal clustering in the MOB effect was found during 1900-1988. Both HLA-DR15 positive (34% increase, p = 0.043) and DR15 negative (48% increase, p = 0.0095) MS patients exhibited an increase in spring births (in May). HLA-DR15 in healthy subjects was not associated with MOB.

CONCLUSIONS

We confirm that spring birth increases MS risk. This phenomenon was not associated with HLA-DR15 and there was no evidence of temporal clustering. The MOB effect suggests that early developmental processes may modulate MS risk.

Symptomatic therapy in multiple sclerosis

Multiple sclerosis is the most common disabling neurological disease of young adults. The ability to impact the quality of life of patients with multiple sclerosis should not only incorporate therapies that are disease modifying, but should also include a course of action for the global multidisciplinary management focused on quality of life and functional capabilities.

Genetic background of multiple sclerosis

Multiple sclerosis (MS) is a one of the group of diseases labeled as "common complex". Virtually all common complex traits, genetic and environmental components have important roles, both independently and interactively, in disease susceptibility and stochastic and epigenetic effects cannot be overlooked. Data presented are largely part of the Canada-wide prospective, population-based longitudinal Canadian Collaborative Project on Genetic Susceptibility to MS (CCPGSMS) which includes over 30,000 unique families having at least 1 member with MS. Findings do not support a general propensity to autoimmune disease in MS families, but clearly highlight the importance of controlling for gender (patient, informant) when conducting such studies. The MHC class II association has been fine-mapped to the HLA-DRB5*0101-HLA-DRB1*1501-HLA-DQA1*0102-HLA-DQB1*0602 extended haplotype. This HLA haplotype confers a relative risk of approximately 3 and homozygosity for this haplotype increases the risk by over 6 fold. However, the HLA haplotype loci interactions are complex and include, epistasis, trans and cis effects, and parent-of-origin effects. As well, there may be interactions of EBV and vitamin D with the HLA, In conclusion, using MS as an example, susceptibility for common complex disease most likely results from interactions of genes, environmental interactions and gene/environment interactions.

Relevance of IL7R genotype and mRNA expression in Dutch patients with multiple sclerosis

Background: The interleukin 7 receptor (IL7R) has been recognized as a susceptibility gene for Multiple Sclerosis (MS). Analysis of rs6897932 (the most strongly MS-associated single nucleotide polymorphism (SNP)), showed effects of genotype on the relative expression of membrane-bound to total amount of IL7R mRNA.

Objective: We assessed the relevance of IL7R on MS phenotype (including clinical and magnetic resonance imaging (MRI) parameters) at DNA and mRNA level in Dutch patients with MS.

Methods: The genotype of rs6897932 was analyzed in 697 patients with MS and 174 healthy controls. The relevance of genotype and carriership of the C allele on MS phenotype (disease activity and severity, using clinical and MRI parameters) was assessed. In addition, relative gene expression of membrane-bound to total IL7R mRNA was analyzed with respect to disease phenotype in a subgroup of 95 patients with early relapsing MS.

Results: In particular, homozygosity for the risk allele is a risk factor for MS in our population (ORCC vs CT and TT = 1.65 (95% CI: 1.18–2.30), two-sided p = 0.004). However, no effect of genotype or the relative expression of membrane-bound IL7R (presence of exon 6–7) to total amount of IL7R mRNA (presence of exon 4–5) was found on MS phenotype.

Discussion: Homozygosity for the IL7R exon 6 rs6897932 C allele is associated with a higher risk for MS in our Dutch population. No effect was found of genotype or mRNA expression on disease phenotype.

Role of vitamin D in immune responses and autoimmune diseases, with emphasis on its role in multiple sclerosis

Vitamin D is a seco-steroid involved in calcium and phosphorus metabolism, and bone formation and mineralization, through binding to a specific nuclear receptor, vitamin D receptor (VDR). Besides its well-established functions on bone health, multiple lines of evidence have indicated the immunomodulatory roles of vitamin D. Vitamin D can affect both innate and adaptive immunity, and prevent autoimmune responses efficiently. Vitamin D regulates the immune responses by suppressing T cell proliferation and modulating macrophage functions. Epidemiological studies have shown that vitamin D deficiency is associated with multiple diseases such as rickets and cancer. Moreover, associations between vitamin D and autoimmune diseases have been confirmed in multiple sclerosis (MS), rheumatoid arthritis (RA), etc. The present review mainly summarized the recent findings on the immunomodulatory role of vitamin D in various disorders, with special focus on its role in MS, an autoimmune disease of the nervous system.

Widespread vitamin D insufficiency: A new challenge for primary prevention, with particular reference to multiple sclerosis

In the past 10 years, our knowledge of vitamin D has been revolutionized on two main points. Firstly, this vitamin is not only crucial for bone and calcium metabolism but also exerts major hormonal actions via its active metabolite (calcitriol) and specific receptors in almost all organs. The diverse non-classical actions of vitamin D-i.e. anti-inflammatory, immunomodulatory, antiproliferative and as a neurotransmitter-could have protective and preventive effects for a wide variety of pathologies, such as autoimmune diseases, cancer, infections and cardiovascular affections. Secondly, daily vitamin D requirements have been redefined thanks to many recent metabolic and pathological studies and are about 10 times higher than the amount considered sufficient until a few years ago. The fact that sunshine is the essential natural source of vitamin D and is limited in temperate and Nordic countries, coupled with the fact that modern lifestyle increasingly removes people from exposure to the sun, could explain why a great majority of the general population in these countries are in a state of vitamin D insufficiency. A lack of vitamin D can therefore also be observed in all pathologies but it may play a pathogenic role only in some of them. The incrimination of hypovitaminosis D as a risk factor is a reasonable assumption when several different research approaches used in a given pathology have consistently concluded that vitamin D is likely involved in that pathology. In multiple sclerosis, taken here as a prime example, there is a substantial rationale for vitamin D involvement, based on the findings of different experimental, epidemiological, genetic and immunological studies. Possible curative effects of vitamin D, in addition to a preventive action, are currently being tested but have not yet been demonstrated in most pathologies. However, these two questions appear to be clearly distinct and may involve notably different mechanisms. Lastly, since vitamin D insufficiency exists in most people living in mid- or high-latitude countries, vitamin D could exert multiple major preventive actions, simple supplementation is both safe and inexpensive and, for a vitamin-hormone, supplementation seems obligatory from a general preventive medical point of view alone, it follows that vitamin D supplementation should be organized in these countries to treat all those currently in a state of insufficiency, patients and 'normal' subjects alike, without further delay.