The relevance of vitamin D receptor gene polymorphisms for vitamin D research in multiple sclerosis

The protective role of interaction between vitamin D, sex hormones and calcium in multiple sclerosis

Multiple sclerosis (MS) is a neurological disorder that causes disability and paralysis, especially among young adults. Although interactions of several factors, such as viral infections, autoimmunity, genetic and environmental factors, performance a role in the beginning and progression of the disease, the exact cause of MS is unknown to date. Different immune cells such as Th1 and Th17 play an impressive role in the immunopathogenesis of MS, while, regulatory cells such as Th2 and Treg diminish the severity of the illness. Sex hormones have a vital role in many autoimmune disorders, including multiple sclerosis. Testosterone, estrogen and progesterone have various roles in the progress of MS, which higher prevalence of disease in women and more severe in men reveals the importance of sex hormones' role in this disease. Vitamin D after chemical changes in the body, as an active hormone called calcitriol, plays an important role in regulating immune responses and improves MS by modulating the immune system. The optimum level of calcium in the body with vitamin D modulates immune responses and calcium as an essential ion in the body plays a key role in the treatment of autoimmune diseases. The interaction between vitamin D and sex hormones has protective and therapeutic effects against MS and functional synergy between estrogen and calcitriol occurs in disease recovery. Moreover, vitamin D and calcium interact with each other to regulate the immune system and shift them to anti-inflammatory responses.

Vitamin D Receptor Polymorphisms in a Spanish Cohort of Parkinson's Disease Patients

Background: Vitamin D receptor (VDR) is a nuclear hormone receptor widely expressed in the substantia nigra. Its association with an increased risk of Parkinson's disease (PD) is based on vitamin D deficiency and/or different polymorphisms in its gene receptor. This fact has been demonstrated by several case-control studies. Materials and Methods: Consequently, we investigated the association between VDR ApaI, BsmI, FokI, and TaqI gene polymorphisms and PD in a Spanish cohort that included 54 cases and 17 healthy controls. The detection of single nucleotide polymorphisms (SNPs) was performed using a polymerase chain reaction-restriction fragment length polymorphism. Results: Our data indicate that the SNPs were not associated with the age of onset of PD, nor with the occurrence of motor symptoms. However, only BsmI polymorphism was significantly associated with PD in this Spanish cohort. In fact, BsmI genotype was five times higher among PD patients than among controls, and the A allele was considered as a genetic risk for PD. Additionally, the combination of FokI and BsmI polymorphisms was significantly associated with PD and could represent a risk factor. Conclusion: We conclude that ApaI, TaqI, and FokI polymorphisms were not associated with PD, but BsmI could be a risk factor for PD in this randomized population.

Biological Pathways Associated with Vitamins in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is characterized by early-appearing social communication deficits, with genetic and environmental factors potentially playing a role in its etiology, which remains largely unknown. During pregnancy, certain deficiencies in critical nutrients are mainly associated with central nervous system impairment. The vitamin B9 (folate) is primarily related to one-carbon and methionine metabolism, participating in methyl donor generation. In addition, supplementation with folic acid (FA) is recommended by the World Health Organization (WHO) in the first three gestational months to prevent neural tube defects. Vitamin B12 is related to folate regeneration, converting it into an active form. Deficiencies in this vitamin have a negative impact on cognitive function and brain development since it is involved in myelin synthesis. Vitamin D is intimately associated with Ca2+ levels, acting in bone development and calcium-dependent signaling. This vitamin is associated with ASD at several levels since it has a relation with ASD genes and oxidative stress environment. This review carries the recent literature about the role of folate, vitamin B12, and vitamin D in ASD. In addition, we discuss the possible impact of nutrient deficiency or hypersupplementation during fetal development. On the other hand, we explore the biases of vitamin supplementation studies such as the loss of participants in retrospective studies, as well as multiple variants that are not considered in the conclusion, like dietary intake or auto-medication during pregnancy. In this regard, we aim to contribute to the discussion about the role of vitamins in ASD currency, but also in pregnancy and fetal development as well. Furthermore, stress during pregnancy can be an ASD predisposition, with cortisol as a regulator. In this view, we propose that cortisol is the bridge of susceptibility between vitamin disorders and ASD prevalence.

Relevance of Serum Levels and Functional Genetic Variants in Vitamin D Receptor Gene among Saudi Women with Gestational Diabetes Mellitus

Background: This study explored the association between ApaI-TaqI Single Nucleotide Polymorphisms (SNPs) in a Vitamin D receptor (VDR) and the risk of Gestational Diabetes Mellitus (GDM) in Saudi women, along with the serum levels of vitamin D. Methods: Ninety women with GDM and 90 non-GDM women were enrolled, based on the inclusion and exclusion criteria for pregnant women enrolled in a single-center study. Blood samples were retrieved from 180 pregnant women using ethylenediaminetetraacetic acid (EDTA) tubes. Serum samples were used to measure the vitamin D, 25-hydroxyvitamin D (25(OH)D or calcidiol), and lipid profiles. Blood was used to measure the hemoglobin A1c levels and to isolate the DNA. The polymerase chain reaction (PCR) was performed for the ApaI (rs79785232), BsmI (rs1544410), FokI (rs2228570), and TaqI (rs731236) SNPs in the VDR gene using restriction fragment length polymorphism analysis. Validation was performed using Sanger sequencing. Statistical analyses were performed between the patients with and without GDM using various statistical software packages. Results: The Hardy-Weinberg equilibrium analysis was statistically significant (p > 0.05). The ApaI, BsmI, and TaqI SNPs were associated with alleles, genotypes, and different genetic models (p < 0.05). Vitamin D levels were associated with deficient levels (p = 0.0002), as well as with a normal and overweight body mass index (p = 0.0004). When vitamin D levels were measured with GDM covariates, the fasting plasma glucose (FPG) (p = 0.0001), postprandial blood glucose (PPBG) (p < 0.0001), oral glucose tolerance test (OGTT)-1 h (p = 0.005), high-density lipoprotein (p = 0.022), and low-density lipoprotein cholesterol (LDLc) (p = 0.001) levels were significantly different. When similar vitamin D levels were measured for each genotype, we confirmed that the ApaI SNP was associated with sufficient levels (p < 0.0001), whereas the BsmI, FokI, and TaqI (p < 0.05) were associated with insufficient levels. The logistic regression model confirmed that the first hour of the OGTT (p = 0.005) was strongly associated with GDM, whereas the analysis of variance confirmed that FPG and PPBG (p < 0.05) were strongly associated with all the SNPs evaluated in the VDR gene. Additionally, the second hour of the OGTT (p = 0.048) and LDLc (p = 0.049) were associated with the ApaI and FokI SNP. Moreover, the first hour OGTT (p = 0.045) and lipid profile parameters (p < 0.05) were associated. Haplotype analysis revealed positive associations among the examined SNPs, which seemed compatible with the hypothesis that variants and combinations of multiple SNP genotypes enhance the risk of GDM in women. Haplotype analysis revealed that different combinations of alleles, such as AGCC, CATT, CGTC, AGTC, and CATT (p < 0.05), were strongly associated. The linkage disequilibrium (LD) analysis showed a strong association with all combinations (p < 0.05). Among the gene-gene interactions, all possible combinations showed a positive association (p < 0.05). Conclusions: Low vitamin D levels were observed in women with GDM. The ApaI, BsmI, and TaqI SNPs were associated with genotype and allele frequencies (p < 0.05). Vitamin D and the SNPs in the VDR gene were associated, according to the ANOVA, logistic regression, haplotype analysis, LD analysis, and the generalized multifactor dimensionality reduction model (p < 0.05).

Four common vitamin D receptor polymorphisms and coronary artery disease susceptibility: A trial sequential analysis

Background

Studies on the susceptibility of vitamin D receptor (VDR) polymorphisms to coronary artery disease (CAD) reached controversial results. We performed this study for a more accurate evaluation between the VDR polymorphisms and CAD susceptibility.

Methods

PubMed, Embase, CNKI, Wan Fang, and VIP databases were searched. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to evaluate the associations. Trial sequential analysis (TSA) was introduced to estimate the positive associations. The potential functions of the VDR polymorphisms were analyzed based on the SNPinfo and ENSEMBL databases.

Results

Thirteen studies were finally included. In the overall analysis, increased CAD risks were observed in the VDR rs1544410 polymorphism and verified by the TSA; for the rs2228570 and rs731236 polymorphisms, significant associations with high heterogeneity were detected; decreased risk was remarkably observed for the rs7975232 polymorphism. In the subgroup analysis, wide associations with reduced heterogeneity were observed in the rs2228570, rs1544410, and rs731236 polymorphisms. The RNAfold analysis indicated the mutant G allele of the rs1544410 polymorphism was easier to disperse from the DNA double helix structure and may have a potential crucial role in the VDR transcription process.

Conclusions

Our analysis supports the role of the rs1544410 polymorphism in the VDR gene as a risk factor for CAD. The VDR rs2228570 and rs731236 polymorphisms were associated with increased CAD risks in the White population. Restrict decreased CAD risk was firstly discovered in the rs7975232 polymorphism.

Limitations

Firstly, the language was restricted to English and Chinese, which will cause the limited number of studies included; secondly, other unknown polymorphisms in VDR polymorphisms could also be associated the CAD susceptibility, and more case-control studies with comprehensive clinical outcomes and GWAS studies were required; thirdly, the rs1544410, rs7975232 and rs731236 polymorphism are in strong LD, haploid factors with CAD risk need to be considered; fourthly, the mechanisms of the VDR polymorphism on the VDR gene or RNA or protein were not discussed enough, further mechanistic studies are required; at last, genetic factor was the one side for CAD susceptibility, the interaction between environmental risk factors should be considered.

Vitamin D Receptor and Its Influence on Multiple Sclerosis Risk and Severity: From Gene Polymorphisms to Protein Expression

Multiple sclerosis (MS) is a multifactorial neurodegenerative disease. Low levels of vitamin D are a risk factor for MS and alterations in the vitamin D receptor (VDR) might be a risk factor as well. This study aimed to evaluate whether the VDR rs731236 (Taq-I) and rs4334089 (HpyCH4V) gene polymorphisms and VDR protein expression are associated with MS risk and severity. Vitamin D plasma levels were analyzed in a group of patients. Additional analyses of VDR protein expression and vitamin D levels of patients with different forms of MS (MSSS < 3 and MSSS ≥ 3) were performed. The analysis of the genotypic and allelic frequencies revealed that the rs731236 (Taq-I) gene polymorphism is significantly associated with MS presence. Although the total, cytosolic and nuclear VDR protein contents do not change between MS patients and healthy controls and between patients with different MS severity, vitamin D levels decrease in parallel with an increase in MSSS.

Association of vitamin D receptor polymorphisms with vitamin D and calcium levels in Turkish multiple sclerosis patients

Aim: The present study was conducted to assess the impact of gene (vitamin D receptor [VDR] polymorphisms) - environment (serum vitamin D and calcium levels) interaction on multiple sclerosis (MS) risk. Materials & methods: FokI, BsmI, TaqI and ApaI genotyping were performed in 149 MS patients and 127 controls. We measured serum vitamin D and calcium levels. Results: No significant difference between VDR polymorphisms and MS risk was detected. In patients with FokI ff, BsmI Bb, TaqI Tt and ApaI AA genotypes, vitamin D levels were statistically higher. Serum calcium levels were significantly lower in patients with FokI FF, Ff, all BsmI and TaqI genotypes and ApaI AA and Aa genotypes. Conclusion: No significant association was found between VDR polymorphisms with MS risk.

Vitamin D Receptor Polymorphisms Among the Turkish Population are Associated with Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory disease characterized by demyelination and axonal degeneration affecting the central nervous system. Among the genetic factors suggested to be associated with this disease are polymorphisms to the vitamin D receptor (VDR) gene. We tested the hypothesis that polymorphisms in the vitamin D receptor (VDR) gene are associated with MS. The aim of the study was to investigate the relationship of MS with the VDR gene Fok-I, Bsm-I and Taq-I polymorphisms among the Turkish population. This study contains 271 MS patients and 203 healthy controls. Genomic DNA was isolated from the samples and the VDR gene Fok-I, Bsm-I and Taq-I polymorphism regions were amplified by polymerase chain reaction (PCR). The PCR products were digested, and the genotypes were determined based on size of digested PCR products. Our results demonstrate associations between MS and the distribution of the VDR gene Fok-I T/T polymorphism genotype in a dominant model, VDR gene Fok-I T allele frequency, distribution of VDR gene Taq-I C/C polymorphism genotype in a dominant model and VDR gene Taq-I C allele frequency (Pearson test, p<0.05). However, there was no association between MS and the VDR gene Bsm-I polymorphisms for the genotype distribution (Pearson test, p>0.05) or allele frequency (Pearson test, p>0.05). Fok-I and Taq-I VDR gene polymorphisms are significantly associated with MS in dominant, homozygote and heterozygote inheritance models among the Turkish population.

Non-Musculoskeletal Benefits of Vitamin D beyond the Musculoskeletal System

Vitamin D, a fat-soluble prohormone, is endogenously synthesized in response to sunlight or taken from dietary supplements. Since vitamin D receptors are present in most tissues and cells in the body, the mounting understanding of the role of vitamin D in humans indicates that it does not only play an important role in the musculoskeletal system, but has beneficial effects elsewhere as well. This review summarizes the metabolism of vitamin D, the research regarding the possible risk factors leading to vitamin D deficiency, and the relationships between vitamin D deficiency and numerous illnesses, including rickets, osteoporosis and osteomalacia, muscle weakness and falls, autoimmune disorders, infectious diseases, cardiovascular diseases (CVDs), cancers, and neurological disorders. The system-wide effects of vitamin D and the mechanisms of the diseases are also discussed. Although accumulating evidence supports associations of vitamin D deficiency with physical and mental disorders and beneficial effects of vitamin D with health maintenance and disease prevention, there continue to be controversies over the beneficial effects of vitamin D. Thus, more well-designed and statistically powered trials are required to enable the assessment of vitamin D’s role in optimizing health and preventing disease.

Association between polymorphisms in the vitamin D receptor and susceptibility to multiple sclerosis

OBJECTIVES

Multiple sclerosis (MS) is a neurodegenerative chronic inflammatory. Mutations in the vitamin D receptor (VDR) gene can substantially affect serum vitamin D levels or alter its functionality, and can consequently increase susceptibility to developing MS. The objective of this study was to evaluate the association between polymorphisms in the VDR gene and risk of MS in a (Spanish) Caucasian population.

PATIENTS AND METHODS

We conducted a retrospective case-control study comprising 209 patients with relapsing-remitting multiple sclerosis (RRMS) and 836 controls of Caucasian origin from southern Spain. The ApaI (rs7975232), BsmI (rs1544410), Cdx2 (rs11568820), FokI (rs2228570), and TaqI (rs731236) gene polymorphisms were determined by allelic discrimination real-time PCR using TaqMan probes.

RESULTS

The recessive logical regression model, adjusted for age and sex, revealed that the TT genotype for VDR FokI (rs2228570) polymorphism was associated with higher risk of MS (P = 0.0150; OR = 1.82; 95% CI = 1.12-2.94; TT vs. CT + CC). No association between the other polymorphisms and development of MS was found in any of the models analyzed. The haplotype analysis, adjusted for age, smoking, and sex, did not find any statistically significant association between the haplotypes analyzed and risk of MS.

CONCLUSIONS

The VDR FokI (rs2228570) polymorphism was significantly associated with developing MS. We found no influence of the ApaI (rs7975232), BsmI (rs1544410), Cdx2 (rs11568820), FokI (rs2228570), and TaqI (rs731236) gene polymorphisms on the risk of developing MS in our patients.

Vitamin D and its therapeutic relevance in pulmonary diseases

Vitamin D is customarily involved in maintaining bone and calcium homeostasis. However, contemporary studies have identified the implication of vitamin D in several cellular processes including cellular proliferation, differentiation, wound healing, repair and regulatory systems inclusive of host defence, immunity, and inflammation. Multiple studies have indicated corelations between low serum levels of vitamin D, perturbed pulmonary functions and enhanced incidences of inflammatory diseases. Almost all of the pulmonary diseases including acute lung injury, cystic fibrosis, asthma, COPD, Pneumonia and Tuberculosis, all are inflammatory in nature. Studies have displayed strong inter-relations with vitamin D deficiency and progression of lung disorders; however, the underlying mechanism is still unknown. Vitamin D has emerged to possess inhibiting effects on pulmonary inflammation while exaggerating innate immune defenses by strongly influencing functions of inflammatory cells including dendritic cells, monocyte/macrophages, T cells, and B cells along with structural epithelial cells. This review dissects the effects of vitamin D on the inflammatory cells and their therapeutic relevance in pulmonary diseases. Although, the data obtained is very limited and needs further corroboration but presents an exciting area of further research. This is because of its ease of supplementation and development of personalized medicine which could lead us to an effective adjunct and cost-effective method of therapeutic modality for highly fatal pulmonary diseases.

The role of TH17 cells in multiple sclerosis: Therapeutic implications

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) where immunopathology is thought to be mediated by myelin-reactive CD4⁺ T helper (TH) cells. The TH cells most commonly implicated in the pathogenesis of the disease are of TH1 and TH17 lineage, which are defined by the production of interferon-γ and interleukin-17, respectively. Moreover, there is emerging evidence for the involvement of TH17.1 cells, which share the hallmarks of TH1 and TH17 subsets. In this review, we summarise current knowledge about the potential role of TH17 subsets in the initiation and progression of the disease and put a focus on their response to approved immunomodulatory MS drugs. In this regard, TH17 cells are abundant in peripheral blood, cerebrospinal fluid and brain lesions of MS patients, and their counts and inflammatory mediators are further increased during relapses. Fingolimod and alemtuzumab induce a paramount decrease in central memory T cells, which harbour the majority of peripheral TH17 cells, while the efficacy of natalizumab, dimethyl fumarate and importantly hematopoietic stem cell therapy correlates with TH17.1 cell inhibition. Interestingly, also CD20 antibodies target highly inflammatory TH cells and hamper TH17 differentiation by IL-6 reductions. Moreover, recovery rates of TH cells best correlate with long-term efficacy after therapeutical immunodepletion. We conclude that central memory TH17.1 cells play a pivotal role in MS pathogenesis and they represent a major target of MS therapeutics.

Matrix metalloproteinases (MMPs) family gene polymorphisms and the risk of multiple sclerosis: systematic review and meta-analysis

Background

Several studies have reported the association between polymorphisms in Matrix metalloproteinases (MMPs) gene family and risk of Multiple sclerosis (MS). However, the results have been inconsistent and inconclusive. To resolve this issue, here we performed a systematic review and meta-analysis of the MMP-91562 C/T (rs3918242), MMP-3 (− 1612 5A/6A), and MMP-2 (− 1306 C/T) polymorphisms and susceptibility to MS.

Methods

We conducted a comprehensive systematic search in the major electronic database, including Scopus and PubMed to look up for relevant studies published before December 2019 that surveyed the association between the MMP-91562 C/T (rs3918242), MMP-3 (− 1612 5A/6A), and MMP-2 (− 1306 C/T) polymorphisms and susceptibility to MS. The level of association between the polymorphisms and susceptibility to MS in the polled analysis was determined by calculating the odds ratio (OR) and the corresponding 95% confidence interval (CI).

Results

We found 15 studies containing 2430 MS subjects and 2304 controls. A statistically significant association was observed in the all five comparisons of the MMP-91562 C/T polymorphism and MS risk as follows: dominant model (OR = 1.62, 95% CI = 1.03–2.53, P = 0.03), recessive model (OR = 2.69, 95% CI = 1.68–4.29, P < 0.001), allelic model (OR = 1.51, 95% CI = 1–2.28, P = 0.04), TT vs. CC model (OR = 3.20, 95% CI = 1.87–5.46, P < 0.001), and CT vs. CC model (OR = 1.53, 95% CI = 1.02–2.28, P = 0.04).

Conclusions

Our meta-analysis revealed significant association of MMP-9 (− 1562 C/T) Single-nucleotide polymorphism (SNP) with MS susceptibility that increased the disease risk.

Vitamin D and Demyelinating Diseases: Neuromyelitis Optica (NMO) and Multiple Sclerosis (MS)

Vitamin D deficiency is prevalent in all ages regardless of climate or geographical location and evidence is emerging that the incidence of autoimmune diseases is increasing worldwide. Women make up a large proportion of autoimmune disease diagnoses, underscoring the importance of fully elucidating the complex synergistic relationships between estrogens and vitamin D. Vitamin D receptor-activating drugs appear to enhance remyelination in patients diagnosed with multiple sclerosis (MS) and other demyelinating diseases such as neuromyelitis optica (NMO). This review is intended to update health practitioners about the potential role of vitamin D deficiency demyelination and to motivate future research on dietary recommendations for vitamin D in preventing and treating demyel1nating diseases.

Epidemiology of multiple sclerosis in Iran: A systematic review and meta-analysis

BACKGROUND

Multiple sclerosis (MS) is one of the most common neurological disorders and is one of the main causes of disability. The prevalence and incidence of MS in Iran is reported to range from 5.3 to 89/ 100,000and 7 to 148.1/ 100,000, respectively. There are no systematic and meta-analysis studies on MS in Iran. Therefore, this study was conducted to investigate the prevalence and incidence of MS in Iran using meta-analysis.

METHOD

A systematic review of the present study focused on MS epidemiology in Iran based on PRISMA guidelines for systematic review and meta-analysis. We searched eight international databases including Scopus, PubMed, Science Direct, Cochrane Library, Web of Science, EMBASE, PsycINFO, Google Scholar search engine and six Persian databases for peer-reviewed studies published without time limit until May 2018. Data were analyzed using Comprehensive meta-analysis ver. 2 software. The review protocol has been registered in PROSPERO with ID: CRD42018114491.

RESULTS

According to searching on different databases, 39 (15%) articles finalized. The prevalence of MS in Iran was estimated 29.3/ 100,000 (95%CI: 25.6-33.5) based on random effects model. The prevalence of MS in men and women was estimated to be 16.5/ 100,000 (95%CI: 13.7-23.4) and 44.8/ 100,000 (95%CI: 36.3-61.6), respectively. The incidence of MS in Iran was estimated to be 3.4/ 100,000 (95%CI: 1.8-6.2) based on random effects model. The incidence of MS in men was estimated to be 16.5/ 100,000 (95%CI: 13.7-23.4) and the incidence of MS in women was 44.8/ 100,000 (95%CI: 36.3-61.6). The meta-regression model for prevalence and incidence of MS was significantly higher in terms of year of study (p<0.001).

CONCLUSIONS

The results of this study can provide a general picture of MS epidemiology in Iran. The current meta-analysis showed that the prevalence and incidence of MS in Iran is high and is rising over time.

Impaired vitamin D sensitivity

Resistance to vitamin D has been known for decades as vitamin D resistant rickets, caused by mutations of the gene encoding for vitamin D receptor (VDR). Findings of extra-skeletal effects of vitamin D and learning of the molecular mechanisms used by its biologically active metabolite calcitriol revealed other ways leading to its impaired sensitivity. Calcitriol takes advantage of both genomic and non-genomic mechanisms through its binding to vitamin D receptor, located not only in the cell nuclei but also in a perinuclear space. On the genomic level the complex of calcitriol bound to VDR binds to the DNA responsive elements of the controlled gene in concert with another nuclear receptor, retinoid X receptor, and expression of the VDR itself is controlled by its own ligand. These elements were found not only in the promotor region, but are scattered over the gene DNA. The gene expression includes a number of nuclear transcription factors which interact with the responsive elements and with each other and learning how they operate would further contribute to revealing causes of the impaired vitamin D sensitivity. Finally, the examples of major disorders are provided, associated with impairment of the vitamin D function and its receptor.

Vitamin D Receptor in Muscle Atrophy of Elderly Patients: A Key Element of Osteoporosis-Sarcopenia Connection

In this study, we investigated the relationship between sarcopenia (evaluated in term of fibers atrophy), vitamin d receptor protein expression and TaqI/Cdx2/FokI VDR genotypes in an Italian cohort of osteoporosis(n=44) and osteoarthritis (n=55) patients. Muscle biopsies were fixed and investigated by both immunohistochemistry (vitamin d receptor expression) and transmission electron microscopy (satellite stem cells niches). Vitamin d receptor polymorphisms were studied on DNA extracted from muscle paraffin sections. For the first time, we reported that aging differently affects the VDR activation in OA and OP patients. In particular, while in OP patients we observed a significant reduction of VDR positive myonuclei with age, no “age effect” was observed in OA patients. The frequent activation of VDR could explain the lower number of atrophic fiber that we observed in OA patients respect to OP. From genetic point of view, we showed a putative association among polymorphisms FokI and Cdx2 of VDR gene, vitamin d receptor activation and the occurrence of sarcopenia. Altogether these data open new prospective for the prevention and cure of age-related muscle disorders.

A Pharmacogenetic Study of VDR fok1 and TYMS Polymorphisms and Their Association With Glucocorticoid-Induced Osteonecrosis in Egyptian Children With Acute Lymphoblastic Leukemia

Purpose: Osteonecrosis is a significant toxicity resulting from the treatment of pediatric Acute Lymphoblastic Leukemia (ALL). This study aimed to investigate the relationship between vitamin D receptor fok1 (VDR fok1) and thymidylate synthase (TYMS) gene polymorphisms with the glucocorticoid (GC) induced osteonecrosis (ON) in Egyptian pediatric ALL patients. In addition, to identify the possible association of genetic polymorphisms with other factors such as gender and ALL subtypes.

Patients and Methods: A retrospective case-control study was conducted on 102 pediatric ALL patients under the age of 18 who were treated at Children Cancer Hospital Egypt according to St Jude SR/HR total XV protocol. The recruited patients were composed of 51 cases who developed GC-induced osteonecrosis and 51 age- and gender-matched patients who received glucocorticoids but remained osteonecrosis-free (controls). Genotyping of the VDR fok1 and TYMS genes was performed using restriction fragment length polymorphism (RFLP) and conventional PCR, respectively.

Results: For the total 102 studied patients, the VDR fok1 single nucleotide polymorphisms (SNPs) frequency distribution were TT (8.8%), CT (34.3%), and CC (56.9%), while the TYMS tandem repeat gene variations were reported as 2R2R (20.6%), 2R3R (45.1%), and 3R3R (34.3%). VDR fok1 and TYMS polymorphic variants showed no association neither with gender; P-values 0.3808 and 0.1503, respectively, nor with ALL subtypes; P-values 0.9396 and 0.6596, respectively. The VDR fok1 polymorphisms showed a significant association with the development of ON; P-value = 0.003, on the other hand, TYMS tandem repeats did not show significant impact on osteonecrosis development; P-value = 0.411.

Conclusion: This study showed a significant association between the VDR fok1 polymorphism and osteonecrosis. Such clinical pharmacogenetics results would be promising to discuss the possibility of dose adjustments aiming a regimen with the highest efficacy and least toxicity.

Vitamin D receptor gene polymorphisms in multiple sclerosis disease: A case-control study

Multiple sclerosis (MS) is a common neurologic disorder that is a chronic inflammatory, demyelinating, and neurodegenerative disease of the central nervous system (CNS). Its etiology remains unknown. Several recent studies have found that decreased susceptibility to vitamin D deficiency is also associated with a decreased risk of MS. The role of vitamin D receptor (VDR) gene and its polymorphisms are highlighted as susceptible components. In this study, we aimed to identify the relationship between ApaI (rs7975232), BsmI (rs 1544410), and TaqI (rs731236) gene polymorphisms with MS. ApaI, BsmI, and TaqI genotypes were determined in 70 patients with MS and in 70 control subjects. DNA was isolated from blood samples, and then ApaI, BsmI and TaqI gene polymorphisms were identified using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The distribution of BsmI and TaqI polymorphisms did not show any significant differences in MS patients and controls; however, increased A allele of ApaI polymorphism was found in MS patients. Our findings suggest that the ApaI gene polymorphism might be associated with MS. Investigation of a larger population and functional work on these gene structures and function in MS patients are recommended.

Role of gene polymorphisms in vitamin D metabolism and in multiple sclerosis

Multiple sclerosis (MS) is a complex inflammatory disease of the central nervous system (CNS) resulting in neurological impairment and disability. There is evidence that adequate vitamin D levels may lower the risk of MS development. The aetiology of MS is complex and involves both genetic and environmental factors. In fact, not one but several genes are believed to lead to the disease. As for environmental factors, one of the most important risk factors is vitamin D deficiency, which, in turn, is closely related to gene polymorphisms that play a role in vitamin D metabolism and regulation. However, information about these gene polymorphisms is quite contradictory. The aim of this review is to discuss the association between some of the vitamin D-related gene variants and MS.

Association of VDR gene polymorphisms with risk of relapsing-remitting multiple sclerosis in an Iranian Kurdish population

PURPOSE

The purpose of this study was to evaluate the association of VDR Apa-I, Bsm-I, Fok-I, Taq-I single nucleotide polymorphisms (SNPs) with multiple sclerosis (MS) risk in an Iranian Kurdish population.

MATERIALS AND METHODS

A population including of 118 patients and 124 healthy matched controls were recruited to the study. Genotyping of the SNPs was accomplished using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

The frequency of allele T of Fok-I (P = 0.003) and allele C of Taq-I (P = 0.0003) was significantly different between case and control subjects and showed significant association with risk of MS (OR = 1.84, 95% CI = 1.23-2.76; OR = 1.98, 95% CI = 1.36-2.87, respectively). CT genotype (OR = 1.7, 95% CI = 1.05-2.99) of Fok-I and CC genotype (OR = 2.18, 95% CI = 1.05-4.52) of Taq-I showed a predisposing effect. Combined TT+TC vs. CC for Fok-I (OR = 2.15, 95% = CI 1.29-3.60) and combined CC+TC vs. TT for Taq-I (OR = 2.58, 95% CI 1.51-4.40) were susceptibility genotypes for MS. Apa-I and Bsm-I were not significantly associated with risk of MS (OR < 1, P > 0.05) and any genotypes in any genetic models were not significantly different between cases and controls (P > 0.05).

CONCLUSION

As a result, Fok-I and Taq-I showed significant association with risk of MS, while Apa-I and Bsm-I were not observed to be related to the risk of the disease in this population.

Multiple Sclerosis

Multiple sclerosis (MS) is a chronic disease of the central nervous system (CNS) characterized by loss of motor and sensory function that results from immune-mediated inflammation, demyelination, and subsequent axonal damage.

Clinically, most MS patients experience recurrent episodes (relapses) of neurological impairment, but in most cases (60–80%) the course of the disease eventually becomes chronic and progressive, leading to cumulative motor, sensory, and visual disability, and cognitive deficits.

The course of the disease is largely unpredictable and its clinical presentation is variable, but its predilection for certain parts of the CNS, which includes the optic nerves, the brain stem, cerebellum, and cervical spinal cord, provides a characteristic constellation of signs and symptoms. Several variants of MS have been nowadays defined with variable immunopathogenesis, course and prognosis. Many new treatments targeting the immune system have shown efficacy in preventing the relapses of MS and have been introduced to its management during the last decade.

Vitamin D Deficiency in Egyptian Systemic Lupus Erythematosus Patients: How Prevalent and Does It Impact Disease Activity?

BACKGROUND

The emerging role of vitamin D in immunology and autoimmune disorders has been a worldwide interest in the last decade. Systemic lupus erythematosus (SLE) patients are particularly at a delicate position predisposing them to suffer from vitamin D deficiency due to the multiple risk factors accompanying the disease. Whether vitamin D deficiency is also involved as a risk factor for developing SLE and affecting its course is a considerable concern.

OBJECTIVES

The objective of this study was to estimate the prevalence of vitamin D deficiency in SLE patients and its relation to disease.

MATERIALS AND METHODS

In our observational cross-sectional study, serum levels of vitamin D [25(OH)D] in 60 SLE patients and 30 age- and sex-matched healthy controls were assessed and estimated for deficiency and insufficiency at 10 and 30 ng/mL, respectively. Disease activity was evaluated by SLE disease activity index (SLEDAI), irreversible organ damage by Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI), and severity by Severity of Disease Index. Fatigue was measured by visual analog scale.

RESULTS

Significantly lower levels of 25(OH)D were found in SLE patients (17.6 ± 6.9 ng/mL) in comparison to controls (79.0 ± 28.7 ng/mL), with a statistically high significant difference (t = -11.2, P < 0.001). High prevalence of vitamin D insufficiency and deficiency was detected as 73.3% and 23.3%, respectively. Vitamin D had a highly significant negative correlation with SLEDAI (r = -0.495, P < 0.001), SLICC (r = -0.431, P < 0.05), and fatigue (r = -0.436, P < 0.05).

CONCLUSION

Vitamin D deficiency and insufficiency were found to be prevalent in SLE patients in our study and related to disease activity and fatigue. If needed, routine screening and consequent repletion of vitamin D are recommended in SLE patients. Restoring adequate vitamin D levels in SLE patients should be more explored as a potential yet simple measure to their usual management to improve their condition.

Predisposing role of vitamin D receptor (VDR) polymorphisms in the development of multiple sclerosis: A case-control study

Multiple sclerosis (MS) is a chronic inflammatory, demyelinating, and neurodegenerative disease of the central nervous system (CNS) with a complex etiology. Given the Vitamin D receptor (VDR) gene, it is considered an outstanding risk component associated with MS. The aim of the present study has been to explore and emphasize the role of ApaI, BsmI, TaqI and FokI polymorphisms of VDR gene in susceptibility to MS in an Iranian case-control population including 160 patients and 150 healthy controls. All cases were clinically diagnosed with relapsing-remitting (RR) form, and the controls were age, gender, and race matched which were completely in agreement with the case group. PCR-R FLP was conducted for all the SNPs genotyping. The findings of the study showed a significant difference in allele frequency between the cases and controls for ApaI (p<0.0002), BsmI (p<0.0002) and TaqI (p<0.0001), while no significant difference was observed for FokI (P>0.0125). The results also showed that AA genotype polymorphism of ApaI and BsmI (OR=4.6 and OR=2.52, respectively), CC genotype of TaqI (OR=2.41) and AC genotype of ApaI (OR=1.79) are associated with the disease status. Nevertheless, the results revealed the protective role of TT genotype of TaqI (ORs<1), CC genotype of Apal, and GG genotype of BsmI (ORs<1). VDR polymorphisms seem to have a notable connection with MS pathogenesis, however, study of more big population and functional work on the gene structure and its function are recommended.

Essential vitamins for an effective T cell response

Effective adaptive immune responses rely upon appropriate activation of T cells by antigenic peptide-major histocompatibility complex on the surface of antigen presenting cells (APCs). Activation relies on additional signals including co-stimulatory molecules on the surface of the APCs that promote T cell expansion. The immune response is further sculpted by the cytokine environment. However, T cells also respond to other environmental signals including hormones, neurotransmitters, and vitamins. In this review, we summarize the mechanisms through which vitamins A and D impact immune responses, particularly in the context of T cell responses.

ApaI, BsmI, FokI, and TaqI Polymorphisms in the Vitamin D Receptor Gene and Parkinson's Disease

Background:

The vitamin D receptor (VDR) gene has been identified as a candidate gene for susceptibility to Parkinson's disease (PD), but results from genetic association studies to date are inconsistent. Here, we conducted a meta-analysis of published case-control studies to evaluate the association of the extensively studied VDR ApaI (G/T), BsmI (G/A), FokI (C/T), and TaqI (T/C) gene polymorphisms with risk of PD.

Methods:

Electronic search at PubMed, EMBASE, EBSCO, China National Knowledge Infrastructure, Weipu database, and Wanfang database was conducted to identify all relevant studies. Odds ratio (OR) with 95% confidence interval (CI) values was applied to evaluate the strength of the association.

Results:

A total of seven studies with 2034 PD cases and 2432 controls were included in the meta-analysis following the inclusion and exclusion criteria. Overall, no significant association between ApaI, BsmI, and TaqI gene polymorphisms and PD susceptibility in all four genetic models was found (T vs. G: OR = 1.00, 95% CI: 0.89–1.12, P = 0.97; A vs. G: OR = 0.94, 95% CI: 0.77–1.15, P = 0.53; C vs. T: OR = 1.03, 95% CI: 0.85–1.25, P = 0.77) while a significant association between FokI (C/T) and PD risk was observed (C vs. T: OR = 1.41, 95% CI: 1.14–1.75, P = 0.001; CC vs. TT: OR = 2.45, 95% CI: 1.52–3.93, P = 0.0002; CT vs. TT: OR = 2.21, 95% CI: 1.38–3.52, P = 0.0009, CC vs. CT+TT: OR = 2.32, 95% CI: 1.49–3.61, P = 0.0002).

Conclusions:

Polymorphisms of ApaI, BsmI, and TaqI may not be associated with the susceptibility to PD while the FokI (C/T) polymorphism is possibly associated with increased PD risk. However, conclusions should be cautiously interpreted due to the relatively small number of studies included.

Illuminating vitamin D effects on B cells--the multiple sclerosis perspective

Vitamin D is associated with many immune-mediated disorders. In multiple sclerosis (MS) a poor vitamin D status is a major environmental factor associated with disease incidence and severity. The inflammation in MS is primarily T-cell-mediated, but increasing evidence points to an important role for B cells. This has paved the way for investigating vitamin D effects on B cells. In this review we elaborate on vitamin D interactions with antibody production, T-cell-stimulating capacity and regulatory B cells. Although in vitro plasma cell generation and expression of co-stimulatory molecules are inhibited and the function of regulatory B cells is promoted, this is not supported by in vivo data. We speculate that differences might be explained by the B-cell-Epstein-Barr virus interaction in MS, the exquisite role of germinal centres in B-cell biology, and/or in vivo interactions with other hormones and vitamins that interfere with the vitamin D pathways. Further research is warranted to illuminate this tube-versus-body paradox.

Clustering of autoimmune diseases in patients with rosacea

BACKGROUND

Rosacea is a common inflammatory skin condition that shares genetic risk loci with autoimmune diseases such as type 1 diabetes mellitus (T1DM) and celiac disease. A recent genomewide association study identified 90 genetic regions associated with T1DM, celiac disease, multiple sclerosis, and/or rheumatoid arthritis, respectively. However, a possible association with rosacea was not investigated.

OBJECTIVE

We evaluated the association between rosacea and T1DM, celiac disease, multiple sclerosis, and rheumatoid arthritis, respectively.

METHODS

We performed a population-based case-control study. A total of 6759 patients with rosacea were identified and matched with 33,795 control subjects on age, sex, and calendar time. We used conditional logistic regression to calculate crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

After adjustment for smoking and socioeconomic status, patients with rosacea had significantly increased ORs for T1DM (OR 2.59, 95% CI 1.41-4.73), celiac disease (OR 2.03, 95% CI 1.35-3.07), multiple sclerosis (OR 1.65, 95% CI 1.20-2.28), and rheumatoid arthritis (OR 2.14, 95% CI 1.82-2.52). The association was mainly observed in women.

LIMITATIONS

We were unable to distinguish between the different subtypes and severities of rosacea.

CONCLUSIONS

Rosacea is associated with T1DM, celiac disease, multiple sclerosis, and rheumatoid arthritis, respectively, in women, whereas the association in men only reached statistical significance for rheumatoid arthritis.

Age- and gender-specific effects on VDR gene polymorphisms and risk of the development of multiple sclerosis in Tunisians: a preliminary study

The vitamin D receptor (VDR) polymorphisms have been reported to be associated with multiple sclerosis (MS); however, evidence remains conflicting. In this report, we investigated the association between two single nucleotide polymorphisms (SNPs) TaqI and ApaI of VDR gene and risk development of MS. TaqI and ApaI SNPs were detected by PCR-RFLP from the DNA of 60 Tunisian patients with MS and 114 healthy controls. Our results show a significant difference of the allelic frequency distribution between the case and control groups for TaqI SNP (P = 0.01), but genotype frequencies were not significantly different (P = 0.07 and 0.23). When adjusting frequency distribution of different alleles and genotypes by age, we found that the difference between the T allele frequencies of this SNP in the group of patients age [15-24] in comparison with the control group of the same age group was statistically significant (P = 0.026). Moreover, frequency of the T allele was significantly higher in male patients compared with controls of the same sex (P = 0.017). However, neither the genotype nor the allele frequency distribution was significantly different between the MS and control populations for the ApaI SNP. Our preliminary results indicate that VDR gene polymorphism could be associated with susceptibility to MS. The role of VDR gene polymorphism should be further studied in other large populations, and the distribution of other polymorphism, such as FokI and BsmI, should be also analysed to confirm another susceptibility polymorphisms gene for MS and to obtain more adequate strategies for treatment of MS.

Vitamin D Actions on CD4(+) T Cells in Autoimmune Disease

This review summarizes and integrates research on vitamin D and CD4⁺ T-lymphocyte biology to develop new mechanistic insights into the molecular etiology of autoimmune disease. A deep understanding of molecular mechanisms relevant to gene–environment interactions is needed to deliver etiology-based autoimmune disease prevention and treatment strategies. Evidence linking sunlight, vitamin D, and the risk of multiple sclerosis and type 1 diabetes is summarized to develop the thesis that vitamin D is the environmental factor that most strongly influences autoimmune disease development. Evidence for CD4⁺ T-cell involvement in autoimmune disease pathogenesis and for paracrine calcitriol signaling to CD4⁺ T lymphocytes is summarized to support the thesis that calcitriol is sunlight’s main protective signal transducer in autoimmune disease risk. Animal modeling and human mechanistic data are summarized to support the view that vitamin D probably influences thymic negative selection, effector Th1 and Th17 pathogenesis and responsiveness to extrinsic cell death signals, FoxP3⁺CD4⁺ T-regulatory cell and CD4⁺ T-regulatory cell type 1 (Tr1) cell functions, and a Th1–Tr1 switch. The proposed Th1–Tr1 switch appears to bridge two stable, self-reinforcing immune states, pro- and anti-inflammatory, each with a characteristic gene regulatory network. The bi-stable switch would enable T cells to integrate signals from pathogens, hormones, cell–cell interactions, and soluble mediators and respond in a biologically appropriate manner. Finally, unanswered questions and potentially informative future research directions are highlighted to speed delivery of etiology-based strategies to reduce autoimmune disease.

The role of epidemiology in MS research: Past successes, current challenges and future potential

Multiple sclerosis (MS) is a multifaceted condition, with a range of environmental, behavioural and genetic factors implicated in its aetiology and clinical course. Successes in advancing our appreciation of the roles of Epstein-Barr virus, vitamin D/UV and the HLA-DRB1 locus; and our greater understanding of these and related factors’ modes of action in MS and other conditions, can be attributed in no small part to the work of generations of epidemiologists. Hardly content to rest on our laurels, however, there are yet a range of unsolved conundrums in MS, including some changes in epidemiological characteristics (e.g. increasing incidence and sex ratio), to say nothing of the unresolved parts regarding what underlies MS risk and its clinical course. There is evidence that epidemiology will continue to play a crucial role in unravelling the architecture of MS causation and clinical course. While classic epidemiological methods are ongoing, novel avenues for research include gene-environment interaction studies, the world of ‘-omic’ research, and the utilisation of mobile and social media tools to both access and track study populations, which means that the epidemiological discoveries of the past century may be but a glimpse of our understanding in the next few decades.

Association between vitamin D receptor polymorphisms and multiple sclerosis: systematic review and meta-analysis of case-control studies

Vitamin D receptor (VDR) polymorphisms have been studied as potential contributors to multiple sclerosis (MS). However, published studies differ with respect to study design and the significance of the effects detected. The aim of this study was to quantify the magnitude of the risk associated with the TaqI, BsmI, ApaI and FokI VDR polymorphisms in MS using a meta-analysis approach. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a systematic search and meta-analysis of the literature. Subgroup analyses were performed to detect potential sources of heterogeneity from the selected study characteristics. The stability of the summary risk was evaluated using sensitivity analyses. The meta-analysis included a total of 3300 cases and 3194 controls from 13 case-control studies. There were no significant associations found between TaqI and BsmI polymorphisms and MS risk. The association between the ApaI polymorphism and MS risk was significant in the homozygous and codominant models (P=0.013 and P=0.031, respectively), suggesting that the AA ApaI genotype might be a significant MS risk factor. Publication year and age significantly affected the association between TaqI polymorphisms and MS (P=0.014 and P=0.010, respectively), which indicates a protective effect of the major T allele. The AA ApaI and FF FokI genotypes are significant risk factors for MS. The association between the TaqI polymorphism and MS risk is significantly affected by study characteristics.

Vitamin D Receptor Gene Polymorphism and the Risk of Multiple Sclerosis in South Eastern of Iran

Multiple sclerosis is one of the most widespread demyelinating diseases of the central nervous system. Environmental and genetic factors are collaborating in triggering MS. The role of vitamin D receptor (VDR) gene and its polymorphisms are highlighted as susceptible components. The aim of the present study was to examine the association of single nucleotide polymorphism (SNP)-BsmI and FokI-in VDR gene and MS susceptibility in the South Eastern Iranian population. Therefore, 113 MS patients and 122 controls were recruited in the study. Restriction fragment length polymorphism was performed to detect the SNPs. There were no significant differences in the polymorphism of FokI (rs2228570) in VDR gene among patients and controls (P > 0.05), while a significant difference was observed in BsmI (rs1544410) polymorphism in healthy subjects and homozygous genotype-b/b- with MS (P = 0.025). Results showed a protective association of homozygous genotype-b/b- of BsmI with MS susceptibility in a population in South Eastern of Iran.

An integrated approach to defining genetic and environmental determinants for major clinical outcomes involving vitamin D

There is substantial genetic and epidemiological evidence implicating vitamin D in the pathogenesis of many common diseases. A number of studies have sought to define an association for disease with sequence variation in the VDR gene, encoding the ligand-activated nuclear hormone receptor for vitamin D. The results of such studies have been difficult to replicate and are likely to need to account for specific environmental exposures. Here, we review recent work that has begun to study the interactions between VDR gene polymorphisms, vitamin D blood levels, and complex disease susceptibility, notably in the context of major clinical outcomes. We highlight the challenges moving forward in this area and its importance for effective clinical translation of current research.

The functional polymorphisms of VDR, GC and CYP2R1 are involved in the pathogenesis of autoimmune thyroid diseases

Vitamin D is a multi-functional immune regulator, and a low serum concentration of vitamin D promotes autoimmune inflammation. In this study, we evaluate the association between the prognosis of autoimmune thyroid disease (AITD) and the functional polymorphisms of genes that regulate vitamin D metabolism. For 139 Graves' disease (GD) patients, 116 Hashimoto's disease (HD) patients and 76 control subjects, we genotyped the following polymorphisms using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP): vitamin D receptor (VDR): rs731236, rs7975232, rs2228570 and rs1544410; group-specific component (GC): rs7041 and rs4588; and CYP2R1: rs10741657. The frequency of the TT genotype for the rs731236 polymorphism was higher in GD patients than in HD patients (P = 0·0147). The frequency of the C allele for the rs7975232 polymorphism was higher in GD patients than in control subjects (P = 0·0349). The proportion of GD patients whose anti-thyrotrophin receptor antibody (TRAb) level was >51% was higher in those with the CC genotype than in those with the CA+AA genotypes (P = 0·0065). The frequency of the CC genotype for the rs2228570 polymorphism was higher in HD patients than in control subjects (P = 0·0174) and GD patients (P = 0·0149). The frequency of the Gc1Gc1 genotype for the GC polymorphism and the AG genotype for the CYP2R1 polymorphism were lower in intractable GD than in GD in remission (P = 0·0093 and 0·0268, respectively). In conclusion, genetic differences in the VDR gene may be involved in the development of AITD and the activity of GD, whereas the genetic differences in the GC and CYP2R1 genes may be involved with the intractability of GD.

Low levels of vitamin D in neuromyelitis optica spectrum disorder: association with disease disability

Patients with autoimmune disorders often have low levels of 25-hydroxyvitamin D [25(OH)D3], which correlates with disability or disease activity. Vitamin D may play a role in neuromyelitis optica (NMO) or NMO spectrum disorder (NMOSD), as an important factor involved in immunological pathways. We investigated the relationship between vitamin D levels and disease related disability and clinical activity in patients with NMOSD. Blood samples from 51 patients with NMOSD who were positive for anti-aquaporin4-antibody (AQP4-ab) and 204 healthy controls were collected for 25(OH)D3 measurement. Clinical parameters, including expanded disability status scale (EDSS) score, annualized relapse rate (ARR) and time of blood sampling relative to attack, were determined in patients with NMOSD. We found that 25(OH)D3 levels were significantly lower in patients with NMOSD compared to healthy controls. There was no difference between 25(OH)D3 levels in blood samples taken at relapse or remission, and no association between 25(OH)D3 levels and ARR, but there was an inverse correlation between 25(OH)D3 levels and EDSS scores in patients with NMOSD. It remains to be determined whether low vitamin D levels predispose to NMO and/or modify disease severity, or are secondary to neurological disability. In either case the results could also be of relevance to other neurological diseases such as multiple sclerosis as well as NMO.

Polymorphisms in the vitamin D receptor gene and risk of primary biliary cirrhosis: a meta-analysis

BACKGROUND AND AIM

Primary biliary cirrhosis (PBC) is a chronic and progressive cholestatic autoimmune liver disease. Although many studies have evaluated the association between many functional polymorphisms in the vitamin D receptor (VDR) gene and PBC risk, debates still exist. Our aim is to evaluate the association between VDR gene polymorphisms, including TaqI (rs731236), BsmI (rs1544410), and ApaI (rs7975232), and the risk of PBC by a systematic review.

METHODS

We searched literatures in PubMed, SCOPUS, and EMBASE until July 2013. We calculated pooled odds ratios (OR) and 95% confidence intervals (CIs) using a fixed effects model or a random effects model for the risk to PBC associated with different VDR gene polymorphisms. And the heterogeneity assumption decided the effect model.

RESULTS

A total of six relevant studies, with 1322 PBC cases and 2264 controls, were included in this meta-analysis. The results indicated that TaqI (rs731236) polymorphism was significantly associated with PBC risk (for T vs t OR = 0.75, 95% CI 0.63, 0.89, Pz = 0.001; TT + Tt vs tt OR = 0.62, 95% CI 0.44, 0.86, Pz = 0.005; OR = 0.74, 95% CI 0.58, 0.94, Pz = 0.016 for recessive model), while ApaI (rs7975232) or BsmI (rs1544410) polymorphism did not.

CONCLUSION

Based on current evidences from published studies, the cumulative effect of TaqI polymorphism in VDR was significantly associated with PBC. Larger studies with mixed ethnicity subjects and stratified by clinical and sub clinical characteristics are needed to validate our findings.

Vitamin D concentrations and disease activity in Moroccan children with juvenile idiopathic arthritis

Background

In addition to its important metabolic activities, vitamin D also contributes to the regulation of the immune system. The aim of this study was to assess the relationship between hypovitaminosis D and disease activity in Moroccan children with juvenile idiopathic arthritis (JIA).

Methods

In this cross-sectional study, forty children with JIA were included, all having been diagnosed according to the classification criteria of International League of Associations for Rheumatology (ILAR). The children underwent anthropometric assessment and clinical evaluation. Disease activity was measured using the Disease Activity Score in 28 joints (DAS28) for polyarticular and oligoarticular JIA and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) for enthesitis-related arthritis. Serum 25-hydroxyvitamin [25(OH)D] D₂ and D₃ were measured using radioimmunoassay (RIA). Hypovitaminosis D was defined as serum 25(OH)D <30 ng/ml.

Results

The average age of participants was 11 years ± 4.23. Hypovitaminosis D was observed in 75% of patients. In univariate analyses, 25(OH)D levels were negatively associated with DAS28 for polyarticular and oligoarticular JIA. No significant relationship was found between 25(OH)D levels and BASDAI for juvenile spondylarthropathy. In multivariate linear regression analysis, no association persisted between 25(OH)D levels and DAS28.

Conclusions

Our study suggested that serum levels of vitamin D were low in Moroccan children with JIA disease. Future studies with a larger population are needed to confirm our results.