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

Analysis of Cdx2 VDR gene polymorphism rs11568820 in association with multiple sclerosis in Slovaks

Vitamin D deficiency is involved in the pathogenesis of multiple sclerosis (MS), a severe autoimmune demyelinating disease of the central nervous system. The gene polymorphism Cdx-2 (rs11568820, G/A) seriously influences the trancriptional activity of the vitamin D receptor (VDR) that binds the vitamin D responsive elements of target genes including HLA-DRB1*15. The aim of the present study in Slovaks was to analyse the association of Cdx-2 variants with the risk of MS and disability progression, and to assess the DRB1*15:01 allele as a possible confounding factor. In total, 493 MS patients and 417 healthy controls were involved in this study. The genotyping of Cdx-2 was performed using restriction analysis; DRB1*15:01 positivity was determined by a high-resolution melting analysis of its surrogate marker rs3135388 (G/A). Our results did not prove any allelic association between Cdx-2 and a risk of MS (minor allele A - 0.181 in patients vs. 0.161 in controls, OR = 1.15, .95 CI = 0.90-1.47, p = 0.289). The logistic regression analysis, adjusted for sex and age, showed no differences in Cdx-2 genotype counts when using an additive, dominant or recessive genetic model (p = 0.351, 0.150, 0.240 respectively). The Cdx-2 variants were also not associated with disease disability progression, evaluated using the Multiple Sclerosis Severity Score. The HLA-DRB1*15:01 allele was found to strongly increase the risk of MS in our study (0.300 in patients vs. 0.101 in controls, OR = 3.83, .95 CI = 2.94-4.99, p = 1.016 × 10-26, dominant genetic model OR = 4.62, .95 CI = 3.40-6.26, p = 9.1 × 10-23). In summary, we found the Cdx-2 as a single genetic marker not to be associated with MS development or progression in Slovaks, independently of HLA-DRB1*15:01 status.

Higher IgG level correlated with vitamin D receptor in the hippocampus of a pristane-induced lupus model

INTRODUCTION/OBJECTIVES

Patients with systemic lupus erythematosus (SLE) may have neurological complications, characterizing neuropsychiatric lupus (NPSLE). Studies have investigated alternative therapies such as vitamin D, which has an effect on the immune system and brain, to control manifestations of SLE. Experimental lupus models may be a good alternative to best study the immunological mechanisms underlying the development of NPSLE, and the animal model of pristane-induced lupus (PIL) may mimic SLE symptoms in humans. Our objective was to evaluate central nervous system involvement and vitamin D supplementation in a PIL model.

METHOD

Female BALB/c mice were divided into controls (CO; n = 7), PIL (n = 9), and PIL supplemented with vitamin D (VD; n = 7). The hippocampus area was measured and immunoassays were performed for detecting vitamin D receptor (VDR) and IgG.

RESULTS

The PIL group had a higher hippocampal IgG infiltrate when compared to the CO group. Vitamin D showed potential for reducing IgG infiltration. The hippocampus area was similar in all groups. No differences in VDR expression were observed between groups. A positive correlation was observed between the expression of VDR and IgG in the hippocampus.

CONCLUSION

Our data suggest that increased IgG infiltration into the hippocampus indicated an inflammatory process that may have stimulated VDR expression. Key Points • IgG infiltrate is higher in PIL animals than controls • VDR increases along with IgG infiltrate • Hippocampal VDR expression does not increase with vitamin D supplementation.

Vitamin D levels in Greek patients with systemic lupus erythematosus

OBJECTIVES

Vitamin D deficiency has been observed in autoimmune rheumatic diseases, such as rheumatoid arthritis. The aim was to study vitamin D in patients with systemic lupus erythematosus (SLE) and its relationship with disease activity.

METHODS

In a cohort of 45 patients with SLE, 41 females and 4 males, aged 47.07 ± 2.17 years (mean ± SEM), and range = 21-79 years, 25(OH)D₃ levels were determined by electrochemiluminescence. C₃ and C₄ levels were also analyzed. SLE disease activity was estimated by SLEDAI-2K. Observations were also performed in a control group matched for age and sex.

RESULTS

In this cohort of SLE patients, 25(OH)D₃ levels were 40.36 ± 2.41 nmol/L (mean ± SEM) as opposed to 60.98 ± 4.28 nmol/L in the control group (p < 0.001, Student's t test). Vitamin D levels were related to C₃ (p < 0.001, linear regression analysis), correlation coefficient 0.106, r² = 0.011, and C₄ (p < 0.001); correlation coefficient 0.316 and r² = 0.100; and inversely related to disease activity (p < 0.001), correlation coefficient -0.572 and r² = 0.327. 25(OH)D₃ levels were 17.73 ± 1.20 nmol/L and 12.24 ± 0.93 nmol/L, in the groups without and with renal involvement, respectively (p = 0.001, Student's t test).

CONCLUSIONS

Vitamin D levels are low in SLE patients and are inversely related to disease activity. Routine screening for vitamin D levels should be performed in SLE patients.

Calcium-phosphate metabolism in patients with multiple sclerosis

INTRODUCTION AND OBJECTIVES

The purpose of this study was to evaluate the concentration of 25-hydroxycholecalciferol and parameters of calcium-phosphate metabolism at different periods of relapsing-remitting multiple sclerosis (RRMS).

MATERIALS AND METHODS

Forty-five patients, residents of Poland (49°-50°, N), were enrolled in the study, i.e. 15 immediately after the diagnosis of RRMS, 15 at the early stage and 15 at the advanced stage of RRMS. The results were compared to values obtained in 20 age- and sex-matched controls.

RESULTS

Lower serum concentrations of 25-hydroxycholecalciferol and ionised calcium were found in patients compared to the control group. In patients with the disease duration of 5-6 years, concentrations of 25-hydroxycholecalciferol and ionised calcium were lower than in patients in the earlier period of RRMS. The inverse and clearer direction of changes was found in parathormone serum concentration in patients compared to the controls. In patients with a longer disease duration, a significantly lower 25-hydroxycholecalciferol concentration was found in female patients compared to male patients. In patients, more frequent 25-hydroxycholecalciferol and unsaturated fatty acids' supplementation was observed compared to the controls.

CONCLUSIONS

In RRMS patients, calcium-phosphate metabolism is disturbed which increases during disease progression.

Sunlight exposure and multiple sclerosis in a tropical country

OBJECTIVE

We analysed past and current sun exposure in multiple sclerosis (MS) patients as compared with matched controls in Mexico, a country with tropical climate.

METHODS

In a case-controlled study that include 83 MS patients and 166 matched controls, we inquired about sunlight exposure in two different periods: during adolescence and during the immediate past 5 years. Indicators were: exposure on quotidian and weekend outdoor activities with direct sunlight contact as expressed on frequency by mean number of days, daytime (morning, noon, afternoon), number of hours, visits to sunny places, and use of sunblocking agents. Additional elements were socioeconomic status, skin colour, and antecedent of varicella infection during childhood.

RESULTS

MS patients showed a larger proportion of white skin. MS patients had more sunlight exposure during adolescence (80% versus 60%, P = 0·002); this tendency prevailed on current indicators (46% versus 30%, P = 0·02). However, current exposure on weekends (10% versus 22%, P = 0·02) and visits to the beach (64% versus 98%, P = 0·002) were lower in MS than in controls.

DISCUSSION

Mexico gets more sunlight through the year than areas with high incidence of MS; nevertheless, its prevalence has greatly increased over the last decades, making it a relevant emerging disease. Our results indicate that in a tropical country, there is no association between sunlight exposure and the risk to develop MS, given the immunological effects of sunlight exposure either through UV radiation or vitamin D metabolism.

Contribution of vitamin D insufficiency to the pathogenesis of multiple sclerosis

The contribution of vitamin D insufficiency to the pathogenesis of multiple sclerosis (MS) is reviewed. Among the multiple recently discovered actions of vitamin D, an immunomodulatory role has been documented in experimental autoimmune encephalomyelitis and in humans. This action in the peripheral immune system is currently the main known mechanism through which vitamin D might influence MS, but other types of actions could be involved within the central nervous system. Furthermore, vitamin D insufficiency is widespread in temperate countries and in patients with MS at the earliest stages of the disease, suggesting that the deleterious effects related to vitamin D insufficiency may be exerted in these patients. In fact, many genetic and environmental risk factors appear to interact and contribute to MS. In genetics, several human leukocyte antigen (HLA) alleles (more particularly HLA-DRB1*1501) could favour the disease whereas some others could be protective. Some of the genes involved in vitamin D metabolism (e.g. CYP27B1) also play a significant role. Furthermore, three environmental risk factors have been identified: past Epstein-Barr virus infection, vitamin D insufficiency and cigarette smoking. Interactions between genetic and environmental risk or protective factors may occur during the mother's pregnancy and could continue during childhood and adolescence and until the disease is triggered in adulthood, therefore possibly modulating the MS risk throughout the first decades of life. Furthermore, some clinical findings already strongly suggest that vitamin D status influences the relapse rate and radiological lesions in patients with MS, although the results of adequately powered randomized clinical trials using vitamin D supplementation have not yet been reported. While awaiting these incontrovertible results, which might be long in coming, patients with MS who are currently in vitamin D insufficiency should be supplemented, at least for their general health status, using moderate doses of the vitamin.

Vitamin D and multiple sclerosis: a critical review and recommendations on treatment

Multiple sclerosis (MS) is an immune-mediated and degenerative disease of nervous system, which affects mostly young adults. Vitamin D deficiency is a well-known environmental risk factor for MS and is considerable in terms of immediate clinical implications. In addition to its classical action on regulation of bone homeostasis, vitamin D may have a potent impact on cytokine profiles and neuro-inflammation. Given the immunomodulatory effects of vitamin D and its high rate of deficiency in MS patients, prescribing vitamin D is a remarkable issue in MS. The results from several experimental and clinical studies indicate that vitamin D supplementation may ameliorate the inflammation during the relapse phase and attenuate disease progression. We present the experimental and clinical studies, which assessed the effects of vitamin D on the pathophysiology, prevalence and management of MS. The authors also discuss current recommendations on prescription of this vitamin to MS patients.

[Prevention of multiple sclerosis: a realistic goal?]

Multiple sclerosis (MS) is the most frequent source of chronic neurological disability in Western countries, and its incidence and prevalence are increasing. However, it is possible to determine its prodromal phase and the radiological, biological and immunological endophenotypes that are present before the clinical onset of the disease, despite remaining unseen with the naked eye. In this context, greater knowledge of the aetiological factors, both genetic and environmental, may lead the way towards primary prevention strategies for MS in the near future.

Relationship between 25-OH-D serum level and relapse rate in multiple sclerosis patients before and after vitamin D supplementation

BACKGROUND

Vitamin D could play a protective role in multiple sclerosis.

METHODS

In an observational, uncontrolled study, vitamin D3 supplementation (3010 IU/day on average) was given to 156 consecutive patients with relapsing-remitting multiple sclerosis, under first-line immunomodulatory therapy and with initial 25-OH-D serum level lower than 100 nmol/l (40 ng/ml). Relapses were determined for 29.1 ± 8.4 months during vitamin D and 29.8 ± 10.1 months before supplementation. The 25-OH-D level was measured before supplementation and several times during supplementation. The incidence rate of relapses before and during supplementation was estimated using negative binomial regression models with follow-up durations as offset terms. The incidence rate and incidence rate ratio of relapses at various 25-OH-D levels were also calculated using negative binomial regression models.

RESULTS

In 76 patients, immunomodulatory therapy preceded vitamin D supplementation (by 4.2 ± 2.7 years) and in 80 patients both treatments were started simultaneously. Under supplementation, the 25-OH-D level increased from 49 ± 22 nmol/l to 110 ± 26 nmol/l on average. Pooling data collected before and during supplementation, we found a significant strong inverse relationship between the relapse incidence rate and the 25-OH-D level (p < 0.0001), suggesting that vitamin D did indeed influence the relapse rate. Results of univariate, bivariate and multivariate analyses were analogous: in the multivariate model adjusted for age, disease duration and previous use of immunomodulatory therapy, every 10 nmol increase in 25-OH-D level was associated with a reduction in the relapse incidence rate of 13.7%. Dividing iteratively the population made up of pooled periods into two subgroups according to the 25-OH-D levels, the relapse incidence rate ratio decreased as the 25-OH-D level increased up to 110 nmol/l, but a plateau effect was observed beyond this limit.

CONCLUSION

Further studies are warranted for accurate quantification of the vitamin D effect.

Vitamin D and autoimmune disease

Vitamin D as a part of the endocrine system is an important component in the interaction between the kidney, bone, parathyroid hormone, and the intestine, which maintains extracellular calcium level within normal limits, in order to keep the vital physiologic process and skeletal integrity. Vitamin D is also associated with hypertension, muscular function, immunity, and ability to encounter infection, autoimmune disease, and cancer. The role of vitamin D in immunity is a feedback reaction of paracrine to eliminate inflammation or to influence CD4 T-cell differentiation and or to increase the function of T suppressor cell or combination between both. The active form of vitamin D produces and maintains self immunologic tolerance, some studies show that 1,25(OH)2D inhibits induction of disease in autoimmune encephalomyelitis, thyroiditis, type-1 diabetes mellitus, inflammatory bowel disease (IBD), systemic lupus erythematosus, and collagen-induced arthritis and Lyme arthritis.