Association between vitamin D receptor (VDR) polymorphisms and the risk of multiple sclerosis (MS): an updated meta-analysis

Association between vitamin D receptor gene polymorphism and essential hypertension: An updated systematic review, meta-analysis, and meta-regression

The association between Vitamin D Receptor (VDR) gene polymorphisms and essential hypertension (EH) remains controversial. We searched databases (Cochrane Library, EBSCO, EMBASE, LILACS, ProQuest, PubMed, Science Direct, Springer) for studies on VDR gene polymorphisms and EH until May 30, 2024, following PRISMA guidelines. RevMan 5.4.1 provided pooled odds ratio (OR) under Hardy-Weinberg Equilibrium based on allele, additive, dominant, and recessive genetic models. Meta-regression was performed using Comprehensive Meta Analysis V3. Twenty-two studies from thirteen countries were analyzed. The recessive model suggested lower EH risk in individuals with the recessive allele (bb) of BsmI (OR: 0.81; 95%CI, 0.69 to 0.94, p = 0.007; I2 = 35%, p = 0.13). No significant associations were found for FokI, ApaI, and TaqI polymorphisms. Methodological quality significantly influenced EH risk associated with the FokI polymorphism across allele, additive, and dominant models (All p<0.0005). Male proportion influenced EH risk in the additive model for the FokI polymorphism (p = 0.0235), while age impacted risk in the recessive model (p = 0.0327). FokI polymorphism's influence on EH risk varies by sex, age, and study quality. BsmI polymorphism is independently associated with lower EH risk in recessive homozygotes, with no significant associations found for ApaI and TaqI polymorphisms.

Vitamin D in Multiple Sclerosis: A Comprehensive Umbrella Review

BACKGROUND

Multiple sclerosis (MS) is an inflammatory neuroimmune disease with a multifaceted etiology and long-lasting adverse effects. Several studies have explored the role of 25-hydroxyvitamin D (25(OH)D) serum levels, vitamin D receptor (VDR) gene polymorphisms, and vitamin D supplementation (VDS) in individuals with MS.

OBJECTIVES

The aim of this study was to evaluate the relationship of MS with 25(OH)D serum levels, VDR gene polymorphisms, and VDS.

METHODS

We assessed relevant articles published in PubMed, Scopus, and Web of Science from the inception up to 24 February, 2024. Meta-analyses that investigated the link of 25(OH)D serum levels, VDR gene polymorphisms including Apal (rs7975232), BsmI (rs1544410), Taql (rs731236), and Fokl (rs10735810), and VDS with the risk and clinical manifestations of MS were included. The methodological quality of selected articles was assessed by the Assessment of Multiple Systematic Reviews version 2. The statistical analysis of this umbrella review was carried out using RStudio version 2023.03.1 and R version 4.3.2, simultaneously.

RESULTS

A total of 23 of 304 records were entered into this umbrella review with a pooled sample size of 37,567 participants. Eleven articles were rated as high quality, 1 was moderate quality, 1 was low quality, and 10 were critically low quality. The homozygote model of FokI (FF+ff compared with Ff) was significantly associated with an 8% reduction of MS risk (odds ratio: 0.92, 95% confidence interval: 0.86, 0.98; I2 = 0%, P > 0.99).

CONCLUSION

According to existing clinical evidence, the risk of MS may be associated with VDR gene polymorphism. Further studies are needed to explore the association of MS and vitamin D.

TRIAL REGISTRATION NUMBER

This trial was registered at International Prospective Register of Systematic Reviews (PROSPERO) as registration number CRD42024521541.

Vitamin D receptor gene BsmI (rs1544410) polymorphism: role in multiple sclerosis and genotype-phenotype correlations

BACKGROUND

Multiple sclerosis (MS) has a complex pathophysiology which depends on many endogenous and exogenous factors. Vitamin D involvement has been largely studied in MS. The large distribution of the vitamin D receptor (VDR) in different immune cells is suggestive of an immunomodulatory role. The VDR gene polymorphisms have been proposed as potential risk factors for MS development or evolution with non-conclusive results.

METHODS AND RESULTS

We conducted a cross-sectional study including patients ≥ 18 years, with a diagnosis of relapsing remitting MS according to the McDonald Criteria and having a minimum follow-up period of one year after starting a disease modifying therapy. Two study groups were compared based on the Multiple Sclerosis Severity Scale or MSSS: "a slow progressor" group for an MSSS ≤ 5, and a "fast progressor" group for an MSSS > 5. The rs1544410 VDR gene polymorphism was studied for all patients. Eighty patients were included. The fast progressor groups had a higher EDSS at onset, a higher total number of relapses, more frequent and shorter time to secondary progression. The progression profile was not statistically different between genotypes and alleles of the VDR gene polymorphism rs1544410. The CC genotype and wild-type allele exhibited a more aggressive disease phenotype with a higher number of relapses the first year, shorter time to secondary progression and cerebral atrophy on assessment.

CONCLUSIONS

Our results suggest potential genotype-phenotype correlations for the rs1544410 VDR gene polymorphism in the disease course of MS. Future research on a larger scale is needed to confirm these findings.

Association of CD58 rs12044852 and rs2300747 polymorphisms with the risk of multiple sclerosis: A systematic review and meta-analysis

OBJECTIVE

Multiple sclerosis is a serious neurodegenerative disorder that causes disability in young adults. Genetic predisposition of multiple sclerosis is well documented and several single nucleotide polymorphisms (SNPs) of the CD58 were found to be associated with this disease. This systematic review and meta-analysis were done with the aim of finding the association between CD58 gene SNPs (rs12044852 and rs2300747) and the risk of multiple sclerosis (MS).

METHOD

A comprehensive search was done in PubMed, Google Scholar, Embase, and MSGene.org to find the relevant data. Our search yielded 13 relevant publications which were included for meta-analysis consisting of 5194 cases and 5766 controls. All the statistical analysis was conducted using meta and metafor packages in R studio. The odds ratio (OR) along with 95 % confidence intervals and p values were determined using the fixed effects and random effects model. The I2 test was done to measure heterogeneity. Subgroup analysis was performed along with analysis for publication bias.

RESULTS

We found significant association for both rs12044852 (allelic, dominant, over-dominant, heterozygous, and homozygous models) and rs2300747 (allelic, dominant, over-dominant, heterozygous models) with multiple sclerosis. Both the SNPs provided a protective effect for multiple sclerosis. Subgroup analysis indicated that rs12044852 polymorphism provided a protective effect in both Asians and Caucasians. However, for rs2300747, the Asian population showed no statistically significant association with the risk of MS.

CONCLUSION

Polymorphism of rs12044852 and rs2300747 of the CD58 gene provided a protective effect for multiple sclerosis. The protective effect is more prominent in Caucasian populations compared to Asians.

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.

Vitamin D Receptor Gene Polymorphism Predicts the Outcome of Multidisciplinary Rehabilitation in Multiple Sclerosis Patients

Better knowledge about the possible role of genetic factors in modulating the response to multiple sclerosis (MS) treatment, including rehabilitation, known to promote neural plasticity, could improve the standard of care for this disease. Vitamin D receptor (VDR) gene polymorphisms are associated with MS risk, probably because of the role played by vitamin D in regulating inflammatory and reparative processes. The aim of this study was to evaluate the association of the most important functional VDR SNPs (TaqI (T/C), ApaI (A/C), and FokI (C/T)) with functional outcome in MS patients undergoing multidisciplinary inpatient rehabilitation (MDR) treatment, in order to determine whether genetic profiling might be useful to identify subjects with a higher chance of recovery. To this end, 249 MS inpatients with a diagnosis of either progressive (pMS; n = 155) or relapsing remitting (RRMS; n = 94) disease who underwent MDR treatment (average duration = 5.1 weeks) were genotyped for VDR SNPs by real-time allelic discrimination. The rehabilitation outcome was assessed using the modified Barthel Index (mBI), Expanded Disability Status Scale (EDSS), and pain numerical rating scores (NRS) at the beginning and the end of MDR treatment. A positive correlation was observed in RRMS patients between the VDR TaqI major allele (TT) and mBI increase (i.e., better functional recovery), as assessed by the linear and logistic regression analysis adjusted for gender, age, disease duration, time of hospitalization, HLA-DRB1*15.01 positivity, and number of rehabilitative interventions (Beta = 6.35; p = 0.0002). The VDR-1 TaqI, ApaI, FokI: TCC haplotype was also associated with mBI increase in RRMS patients (Beta = 3.24; p = 0.007), whereas the VDR-2: CAC haplotype was correlated with a lower mBI increase (Beta = -2.18 p = 0.04) compared with the other haplotypes. VDR TaqI major allele (TT), as well as the VDR-1 TaqI, ApaI, FokI: TCC haplotype could be associated with a better rehabilitation outcome in RRMS patients.

Immunomodulatory actions of vitamin D in various immune-related disorders: a comprehensive review

For many years, vitamin D has been acknowledged for its role in maintaining calcium and phosphate balance. However, in recent years, research has assessed its immunomodulatory role and come up with conflicting conclusions. Because the vitamin D receptor is expressed in a variety of immune cell types, study into the precise role of this molecule in diseases, notably autoimmune disorders, has been made possible. The physiologically activated version of vitamin D also promotes a tolerogenic immunological condition in addition to modulating innate and acquired immune cell responses. According to a number of recent studies, this important micronutrient plays a complex role in numerous biochemical pathways in the immune system and disorders that are associated with them. Research in this field is still relatively new, and some studies claim that patients with severe autoimmune illnesses frequently have vitamin D deficiencies or insufficiencies. This review seeks to clarify the most recent research on vitamin D's immune system-related roles, including the pathophysiology of major disorders.

VDR Gene Single Nucleotide Polymorphisms and Autoimmunity: A Narrative Review

The vitamin D/Vitamin D receptor (VDR) axis is crucial for human health as it regulates the expression of genes involved in different functions, including calcium homeostasis, energy metabolism, cell growth and differentiation, and immune responses. In particular, the vitamin D/VDR complex regulates genes of both innate and adaptive immunity. Autoimmune diseases are believed to arise from a genetic predisposition and the presence of triggers such as hormones and environmental factors. Among these, a role for Vitamin D and molecules correlated to its functions has been repeatedly suggested. Four single nucleotide polymorphisms (SNPs) of the VDR gene, ApaI, BsmI, TaqI, and FokI, in particular, have been associated with autoimmune disorders. The presence of particular VDR SNP alleles and genotypes, thus, was observed to modulate the likelihood of developing diverse autoimmune conditions, either increasing or reducing it. In this work, we will review the scientific literature suggesting a role for these different factors in the pathogenesis of autoimmune conditions and summarize evidence indicating a possible VDR SNP involvement in the onset of these diseases. A better understanding of the role of the molecular mechanisms linking Vitamin D/VDR and autoimmunity might be extremely useful in designing novel therapeutic avenues for these disorders.

Vitamin D receptor gene polymorphisms are associated with the risk and features of myasthenia gravis in the Han Chinese population

Vitamin D receptor gene (VDR) polymorphisms are candidate genetic variants for susceptibility to autoimmune diseases. Here, we explored the association between VDR polymorphisms and myasthenia gravis (MG) susceptibility and disease features in a Han Chinese population. A total of 151 patients with MG and 146 healthy controls were genotyped for VDR rs1544410, rs2228570, rs731236, and rs7975232 polymorphisms using the improved multiple ligase detection reaction. Information regarding age at onset, acetylcholine receptor (AChR-Ab) and muscle-specific kinase (MuSK-Ab) antibody status, thymus status, involved muscles at onset, and Osserman type at maximum worsening during 2-year follow-up was obtained and used for subclassification grouping. Intergroup comparisons of allele and genotype frequencies and haplotype distributions were performed between the MG and control groups and between each pair of MG subgroups. The VDR rs7975232 polymorphism was associated with the risk of MG in allele, codominant (CC vs. CA), and dominant models (p = 0.040, p = 0.018, and p = 0.018, respectively). Moreover, subjects with the ACC haplotype (order of rs731236, rs7975232, rs1544410) were more likely to develop MG than those with other haplotypes (OR = 1.486, 95% CI: 1.017-2.171, p = 0.040). In a dominant model, the rs7975232 CC genotype frequency was significantly higher in the ocular MG group than in the generalized MG group (p = 0.019). The study findings suggest that the VDR rs7975232 C allele and the ACC haplotype can be associated to an increased susceptibility to the development of MG. Trial registration: NCT05380128.

Vitamin D as a Nutri-Epigenetic Factor in Autoimmunity-A Review of Current Research and Reports on Vitamin D Deficiency in Autoimmune Diseases

Epigenetics is a series of alterations regulating gene expression without disrupting the DNA sequence of bases. These regulatory mechanisms can result in embryogenesis, cellular differentiation, X-chromosome inactivation, and DNA-protein interactions. The main epigenetic mechanisms considered to play a major role in both health and disease are DNA methylation, histone modifications, and profiling of non-coding RNA. When the fragile balance between these simultaneously occurring phenomena is disrupted, the risk of pathology increases. Thus, the factors that determine proper epigenetic modeling are defined and those with disruptive influence are sought. Several such factors with proven negative effects have already been described. Diet and nutritional substances have recently been one of the most interesting targets of exploration for epigenetic modeling in disease states, including autoimmunity. The preventive role of proper nutrition and maintaining sufficient vitamin D concentration in maternal blood during pregnancy, as well as in the early years of life, is emphasized. Opportunities are also being investigated for affecting the course of the disease by exploring nutriepigenetics. The authors aim to review the literature presenting vitamin D as one of the important nutrients potentially modeling the course of disease in selected autoimmune disorders.

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.

5Apal, Taql, Fokl, and Bsml polymorphisms and the susceptibility of Behcet's disease: an updated meta-analysis

OBJECTIVE

The aim of this study was to investigate whether the gene polymorphisms of vitamin D receptor (VDR) had a genetic effect on the susceptibility of Behcet's disease (BD).

MATERIAL AND METHODS

We conducted a meta-analysis emphasizing the association between the VDR gene polymorphisms and the risk of BD. The strength of the association in five genetic models was assessed by pooled odds ratios (OR) with a corresponding 95%confidence interval (CI).

RESULTS

A total of seven independent comparisons with 478 cases and 666 healthy controls were included in this meta-analysis. The overall results suggested that a significant association between ApaI polymorphism and BD risk was found in allele comparison, recessive model, and homozygote model among total populations. Subgroup analysis indicated that a significant association of ApaI polymorphism in the development of BD existed under the allelic model among Africans, while for Caucasians, a similar link was identified in the recessive model and homozygote model. Regarding Bsml polymorphism, an obvious relationship was detected to be significant in allele comparison and recessive model in the Caucasian population. Interestingly, the Fokl variant decreased the risk of BD in Africans under five genetic models, while it increased the risk in Caucasians across the recessive model and homozygote model.

CONCLUSION

The results of this meta-analysis provide evidence of the link between the four widely studied polymorphisms in the VDR gene and BD, indicating a robust estimate of the genetic 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.

Role of Neural Stem Cells and Vitamin D Receptor (VDR)-Mediated Cellular Signaling in the Mitigation of Neurological Diseases

Specific stem cell-based therapies for treating Alzheimer's disease, Parkinson's disease, and schizophrenia are gaining importance in recent years. Accumulating data is providing further support by demonstrating the efficacy of neural stem cells in enhancing the neurogenesis in the aging brain. In addition to stem cells, recent studies have shown the efficacy of supplementing vitamin D in promoting neurogenesis and neuronal survival. Studies have also demonstrated the presence of mutational variants and single-nucleotide polymorphisms of the vitamin D receptor (VDR) in neurological disorders; however, implications of these mutations in the pathophysiology and response to drug treatment are yet to be explored. Hence, in this article, we have reviewed recent reports pertaining to the role of neural stem cells and VDR-mediated cellular signaling cascades that are involved in enhancing the neurogenesis through Wnt/β-catenin and Sonic Hedgehog pathways. This review benefits neurobiologists and pharmaceutical industry experts to develop stem cell-based and vitamin D-based therapies to better treat the patients suffering from neurological diseases.

Re-emerging concepts of immune dysregulation in autism spectrum disorders

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by communication and social interaction deficits, and by restricted interests and stereotyped, repetitive behavior patterns. ASD has a strong genetic component and a complex architecture characterized by the interplay of rare and common genetic variants. Recently, increasing evidence suggest a significant contribution of immune system dysregulation in ASD. The present paper reviews the latest updates regarding the altered immune landscape of this complex disorder highlighting areas with potential for biomarkers discovery as well as personalization of therapeutic approaches. Cross-talk between the central nervous system and immune system has long been envisaged and recent evidence brings insights into the pathways connecting the brain to the immune system. Disturbance of cytokine levels plays an important role in the establishment of a neuroinflammatory milieu in ASD. Several other immune molecules involved in antigen presentation and inflammatory cellular phenotypes are also at play in ASD. Maternal immune activation, the presence of brain-reactive antibodies and autoimmunity are other potential prenatal and postnatal contributors to ASD pathophysiology. The molecular players involved in oxidative-stress response and mitochondrial system function, are discussed as contributors to the pro-inflammatory pattern. The gastrointestinal inflammation pathways proposed to play a role in ASD are also discussed. Moreover, the body of evidence regarding some of the genetic factors linked to the immune system dysregulation is reviewed and discussed. Last, but not least, the epigenetic traits and their interactions with the immune system are reviewed as an expanding field in ASD research. Understanding the immune-mediated pathways that influence brain development and function, metabolism, and intestinal homeostasis, may lead to the identification of robust diagnostic or predictive biomarkers for ASD individuals. Thus, novel therapeutic approaches could be developed, ultimately aiming to improve their quality of life.

Association of vitamin D receptor gene polymorphisms with type 2 diabetes mellitus in Taif population: a case-control study

Abstract Several reasons may underlie the dramatic increase in type2 diabetes mellitus. One of these reasons is the genetic basis and variations. Vitamin D receptor polymorphisms are associated with different diseases such as rheumatoid arthritis and diabetes. The aim of this study is to investigate the possible association of two identified mutations ApaI (rs7975232) and TaqI (rs731236). Eighty-nine healthy individuals and Fifty-six Type 2 Diabetic (T2D) patients were investigated using RFLP technique for genotyping and haplotyping as well. The distribution of Apal genotypes was not statistically significant among the control (P=0.65) as well as for diabetic patients (P=0.58). For Taql allele frequencies of T allele was 0.61 where of G allele was 0.39. The frequency distribution of Taql genotypes was not statistically significant among the control (P=0.26) as well as diabetic patients (P=0.17). Relative risk of the allele T of Apa1 gene is 1.28 and the odds ratio of the same allele is 1.53, while both estimates were < 1.0 of the allele G. Similarly, with the Taq1 gene the relative risk and the odds ratio values for the allele T are 1.09 and 1.27 respectively and both estimates of the allele C were 0.86 for the relative risk and 0.79 for the odds ratio. The pairwise linkage disequilibrium between the two SNPs Taq1/apa1 was statistically significant in control group (D = 0.218, D' = 0.925 and P value < 0.001) and similar data in diabetic groups (D = 0.2, D' = 0.875 and P value < 0.001). These data suggest that the T allele of both genes Apa1 and Taq1 is associated with the increased risk of type 2 diabetes. We think that we need a larger number of volunteers to reach a more accurate conclusion.

ε2 , ε3 , and ε4 variants of ApoE; rs2228570 (VDR), rs4588 and rs7041 (VDBP) polymorphisms in patients with multiple sclerosis: A case-control study in Turkish population

AIM OF THE STUDY

Multiple sclerosis (MS) is a degenerative disease characterized by autoimmune demyelination in the central nervous system. Yet, underlined genetics or environmental markers are still controversial. The impact of vitamin D and cholesterol on disease activity has been phrased by many studies; however, the data available for the Turkish population are very limited. This study aimed to investigate the effect of vitamin D-related polymorphisms (VDBP and VDR) and cholesterol-related variants of ApoE on Turkish MS patients.

MATERIALS AND METHODS

Total DNAs were extracted from peripheral blood samples of 51 MS patients and 50 healthy volunteers. rs4588 and rs7041 polymorphisms of VDBP, rs2228570 of VDR, as well as ε2, ε3, and ε4 variants of ApoE, were investigated by RT-PCR. Biochemical parameters which thought to be associated with MS were also measured. Results were evaluated statistically.

RESULTS

Homozygous mutant genotype and G allele of rs2228570 in VDR, as well as heterozygous genotype of rs4588 in VDBP, were found statistically high in patients. Total cholesterol, triglyceride, and LDL-C levels were found significantly high, whereas HDL-C and vitamin D levels were low in patients. An association was found between rs4588 variation and high triglyceride levels. Similar correlations were found between ε2 genotype and low LDL-C level; ε3 genotype and higher LDL-C. Gender, triglyceride, HDL-C, and AA genotype in rs4588 had a significant effect on MS progression.

CONCLUSION

The variations of rs2228570 and rs4588, vitamin D deficiency, and biological parameters related to cholesterol metabolism may be associated with MS risk.

VDR Gene Polymorphisms and Cluster Headache Susceptibility: Case-Control Study in a Southeastern European Caucasian Population

Cluster headache (CH) is a severe primary headache disorder with a genetic component, as indicated by family and twin studies. Diurnal and seasonal rhythmicity are key features of the disease and might be related to vitamin D, as low vitamin D levels have been observed in patients with cluster headache. In addition, the vitamin D receptor (VDR) occurs in brain areas and particularly in the hypothalamus. The aim of the present case-control study was to investigate the association of cluster headache susceptibility and clinical phenotypes with the VDR gene polymorphisms FokI, BsmI and TaqI in a Southeastern European Caucasian population. DNA was extracted from 131 unrelated CH patients and 282 non-headache controls and genotyped using real-time PCR (melting curve analysis). Linkage disequilibrium (LD) analysis confirmed that BsmI and TaqI, both located in the 3'UTR of the VDR gene, are in strong LD. Genotype and allele frequency distribution analysis of the VDR FokI, BsmI, and TaqI polymorphisms showed no statistically significant difference between cases and controls, whereas haplotype analysis indicated that the TAC haplotype might be associated with decreased cluster headache susceptibility. Intra-patient analysis according to diverse clinical phenotypes showed an association of the BsmI GG and TaqI TT genotypes with more frequent occurrence of CH attacks in this cohort. Therefore, a possible association was observed between VDR gene polymorphisms BsmI and TaqI or a linked locus and susceptibility for cluster headache development and altered clinical phenotypes in the Southeastern European Caucasian study population. Further large-scale replication studies are needed to validate these findings.

Vitamin D Receptor gene polymorphisms and susceptibility to type 2 diabetes: evidence from a meta-regression and meta-analysis based on 47 studies

BACKGROUND

Evidence from various studies suggest that vitamin D receptor (VDR) gene polymorphisms are associated with type 2 diabetes (T2D); However, these results have been disputable. Here we conducted a meta-analysis to comprehensively evaluate the effect of VDR gene polymorphisms and susceptibility to T2D.

METHODS

All relevant studies reporting the association between VDR gene polymorphisms and susceptibility to T2D published up to August 2020 were identified by comprehensive systematic database search in web of science, Scopus, and Medline. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to measure strength of association. The methodological quality of each study was assessed according to the Newcastle-Ottawa Scale. Subgroup and meta-regression analysis were also performed.

RESULTS

A total of 47 case-control studies were included in this meta-analysis. The overall population results revealed a significant association between FokI, and BsmI (heterozygote model) polymorphisms and T2D in the overall analysis. However, no association was found with the TaqI and ApaI polymorphisms. Moreover, the pooled results of subgroup analysis by ethnicity suggested significant association between FokI, TaqI, and BsmI polymorphisms and T2D in some subgroups. Meta-regression analyses indicated that none of the publication year, ethnicity, and genotyping method were the source of heterogenicity in all four polymorphisms.

CONCLUSIONS

This meta-analysis suggested a significant association between VDR gene FokI, and BsmI (heterozygote model) polymorphisms and T2D susceptibility in overall population and ethnic-specific analysis.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40200-020-00704-z.

Orbital inflammatory disorders: new knowledge, future challenges

PURPOSE OF REVIEW

This review aims to bring together recent advances in basic, translational and clinical research on the pathogenesis and treatment of orbital inflammatory conditions.

RECENT FINDINGS

Basic science studies provide mechanistic insights into why the orbit is targeted for inflammation by autoimmune inflammatory disorders. Using Graves' disease as a test case reveals that endocrine pathways, such as the TSH and IGF1 receptor pathways play important roles in stimulating orbital inflammation. Furthermore, orbital tissues contain high concentrations of retinoids - byproducts of the visual pathway that diffuse across the sclera and can activate de novo transcription of inflammatory cytokines. Such cytokine expression places the orbit in a hyper-inflammatory 'resting' state, prone to respond to any additional systemic or local pro-inflammatory signals. The HIF2A--LOX pathway appears important for orbital tissue fibrosis. Lastly, bench-to-bedside studies of the IGF1R pathway have led to an FDA-approved drug, teprotumumab that represents a novel treatment approach for Graves' orbitopathy. Unfortunately, high drug costs and misplaced insurance company 'step-therapy' policies may block patients from receiving therapy that can protect vision and improve quality of life.

SUMMARY

Improved understanding of orbital inflammatory conditions has led to a new drug and promises additional breakthroughs. Translational research is successful, but requires time, resources, and patience.

Fulminating Autoimmune Demyelination with Optic Neuropathy in a Case of Pediatric Cerebral Adrenoleukodystrophy: Case Report and Review of the Literature

X-linked adrenoleukodystrophy (ALD) is a leukodystrophy characterized not only by progressive loss of myelin in the central nervous system due to dysmyelination, but also by acute, subacute, or chronic inflammatory demyelination. This results in the phenotypic variability of cerebral ALD (cerALD), which is independent of the genotype. In this article, we reported a fulminant presentation with fluctuating encephalopathy and visual loss in a patient with childhood onset cerALD. Brain MRI showed symmetric confluent occipito-temporal demyelination with severe disruption of the blood–brain barrier and prechiasmal optic neuropathy. The patient's cerebral spinal fluid (CSF) demonstrated an elevated IgG index, myelin basic proteins, and oligoclonal bands. Within 48 hours of receiving immunomodulating therapy, the patient's symptoms of psychomotor slowing, visual impairment, and areflexia partially resolved. High plasma C26:0 levels and high ratios of C24/22 and C26/22 were diagnostic of ALD. It has been shown that environmental factors play an important role in the inflammatory demyelination responsible for the severe phenotypes of cerALD.

Association of Vitamin D receptor gene variations with Gastric cancer risk in Kashmiri population

Vitamin D receptor (VDR) mediates cellular processes like cell cycle arrest and apoptosis which effect cancer susceptibility. VDR single nucleotide polymorphisms (SNPs) have a significant influence on functioning of VDR protein and subsequently contribute to the risk of cancer occurrence and progression. The present case-control study was carried out between 2016 and 2020 to investigate the association of VDR BsmI/ApaITaqI SNPs with Gastric Cancer (GC) risk in ethnic Kashmiri population not only for establishing a molecular marker for GC but also to facilitate the outcomes of personalized medicine in future. The polymorphisms of BsmI and ApaI of the VDR gene were evaluated using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism followed by Di-Deoxy Sanger sequencing in 143 GC cases and 150 controls. The mean age (in years) was 53.5 ± 7.92 and 51.2 ± 8.25 and mean Body mass index was 22.68 ± 4.27 kg/m² and 23.81 ± 3.71 kg/m² for cases and controls respectively. The mean CEA levels of GC cases was 40.2 ± 10.9 ng/ml. Genotypic distribution of VDR BsmI differed significantly between GC cases and controls (GG vs GA + AA; adjusted P = 0.014) and followed dominant mode of inheritence. Stratification of VDR BsmI revealed that frequency of variant genotype (GA + AA) was significantly higher in Preobese GC cases (P = 0.001), GC patients consuming < 5 cups of salt tea/day (P < 0.0001) and with no family history of gastrointestinal cancer (P = 0.014) compared to healthy controls. ATC haplotype associated with high GC risk. In conclusion, our study suggests that VDR BsmI SNP has a significant association with increased risk of GC especially in preobese population and BsmI/ApaITaqI SNPs significantly decreased the overall survival in GC patients of Kashmiri population.

Vitamin D Resistance as a Possible Cause of Autoimmune Diseases: A Hypothesis Confirmed by a Therapeutic High-Dose Vitamin D Protocol

Vitamin D3 (cholecalciferol) is a secosteroid and prohormone which is metabolized in various tissues to the biologically most active vitamin D hormone 1,25(OH)2D3 (calcitriol). 1,25(OH)2D3 has multiple pleiotropic effects, particularly within the immune system, and is increasingly utilized not only within prophylaxis, but also within therapy of various diseases. In this context, the latest research has revealed clinical benefits of high dose vitamin D3 therapy in autoimmune diseases. The necessity of high doses of vitamin D3 for treatment success can be explained by the concept of an acquired form of vitamin D resistance. Its etiology is based on the one hand on polymorphisms within genes affecting the vitamin D system, causing susceptibility towards developing low vitamin D responsiveness and autoimmune diseases; on the other hand it is based on a blockade of vitamin D receptor signaling, e.g. through pathogen infections. In this paper, we review observational and mechanistic evidence for the acquired vitamin D resistance hypothesis. We particularly focus on its clinical confirmation from our experience of treating multiple sclerosis patients with the so-called Coimbra protocol, in which daily doses up to 1000 I.U. vitamin D3 per kg body weight can be administered safely. Parathyroid hormone levels in serum thereby provide the key information for finding the right dose. We argue that acquired vitamin D resistance provides a plausible pathomechanism for the development of autoimmune diseases, which could be treated using high-dose vitamin D3 therapy.

Vitamin D Receptor (VDR) Gene Polymorphisms and Risk of Coronary Artery Disease (CAD): Systematic Review and Meta-analysis

Several studies have noted that vitamin D receptor (VDR) gene polymorphisms are involved in the susceptibility to Coronary artery disease (CAD). Nonetheless, the results have been inconclusive. Here, we performed the most up-to-date analysis of the association between VDR gene polymorphisms and risk of CAD. We conducted a comprehensive systematic search in the major electronic database, including Scopus and PubMed to look up for relevant studies evaluating the association between the VDR gene FokI (rs2228570), TaqI (rs731236), BsmI (rs1544410), and ApaI (rs7975232) polymorphisms and susceptibility to CAD published before December 2019. The level of association between VDR gene polymorphisms and susceptibility to CAD in the polled analysis was calculated by odds ratio (OR) and the corresponding 95% confidence interval (CI). We found 14 articles containing 20,398 cases and 9371 controls. The analysis revealed that all genetic models in the FokI SNP were associated with increased risk of CAD. Furthermore, for the ApaI SNP, except recessive model, all other genetic models significantly increased the risk of CAD in the overall analysis. In addition, it was divulged that both FokI and ApaI SNPs were involved in increasing the risk of CAD in Asians and Europeans in a number of models. FokI and ApaI polymorphisms may confer a susceptibility genetic risk factor for development of CAD, particularly in the Asian population.

Vitamin D Receptor Polymorphism and Myasthenia Gravis in Chinese Han Population

Myasthenia gravis (MG) is an autoimmune disease in which antibodies bind to acetylcholine receptors (AChR) or other functional molecules in the postsynaptic membrane at the neuromuscular junction. Vitamin D (VD) has a number of pluripotent effects, which include immune-regulation and bone metabolism. The immunomodulatory actions of 1,25(OH)2D3 are mediated by its binding to a vitamin D receptor (VDR). In the study, we undertook a case-control study to explore the association between VDR gene polymorphism and the susceptibility and severity of MG patients. Four hundred and eighty MG patients and 487 healthy controls were included and gene polymorphisms of VDR were determined with improved multiplex ligation detection reaction technique and SNPscan^TM technique. MG patients were classified into subgroups by essential clinical features and by a comprehensive classification. The frequencies of alleles and genotypes were compared between the MG group and the control group, between each MG subgroup and the control group, and between each pair of MG subgroups. There were no significant differences in frequencies of alleles and genotypes between MG patients and healthy controls, between MG subgroups and healthy controls, or between each pair of MG subgroups in the analysis of subgroups classified by essential clinical features (onset age, gender, thymoma, AChRAb positivity, onset involvement) and the maximal severity (modified Oosterhuis score). In the analysis of subgroups with a comprehensive classification, the frequencies of alleles and genotypes in rs731236 showed significant differences between adult non-thymoma AChRAb negative MG subgroup and the control group, as well as the adult non-thymoma AChRAb positive MG group. In the Chinese Han population, rs731236 was found to be possibly associated with adult non-thymoma AChRAb negative MG patients, although this needs further confirmation.

Association of Vitamin D Metabolism Gene Polymorphisms with Autoimmunity: Evidence in Population Genetic Studies

A high prevalence of vitamin D (calcidiol) serum deficiency has been described in several autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis (AR), and systemic lupus erythematosus (SLE). Vitamin D is a potent immunonutrient that through its main metabolite calcitriol, regulates the immunomodulation of macrophages, dendritic cells, T and B lymphocytes, which express the vitamin D receptor (VDR), and they produce and respond to calcitriol. Genetic association studies have shown that up to 65% of vitamin D serum variance may be explained due to genetic background. The 90% of genetic variability takes place in the form of single nucleotide polymorphisms (SNPs), and SNPs in genes related to vitamin D metabolism have been linked to influence the calcidiol serum levels, such as in the vitamin D binding protein (VDBP; rs2282679 GC), 25-hydroxylase (rs10751657 CYP2R1), 1α-hydroxylase (rs10877012, CYP27B1) and the vitamin D receptor (FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) VDR). Therefore, the aim of this comprehensive literature review was to discuss the current findings of functional SNPs in GC, CYP2R1, CYP27B1, and VDR associated to genetic risk, and the most common clinical features of MS, RA, and SLE.

Association between IL7 Receptor Alpha (Il7ra) gene rs6897932 polymorphism and the risk of Multiple Sclerosis: A meta-regression and meta-analysis

BACKGROUND

In this systematic review and meta-analysis, we aimed to find a consistent conclusion for the association between the interleukin 7 receptor alpha (IL7RA) gene rs6897932 single nucleotide polymorphism (SNP) and multiple sclerosis (MS) risk.

METHODS

Here, we performed a comprehensive systematic search in PubMed, Scopus, and Web of Science to find relevant studies published before November 2020 investigating the association between rs6897932 SNP and MS risk. In the pooled analysis, we determined the odds ratio (OR) and the corresponding 95% confidence interval (CI) for the association level between rs6897932 SNP and the risk of MS.

RESULTS

In the current meta-analysis 33 case-control studies (30 articles) containing 19351 patients and 21005 healthy controls certify the inclusion criteria. According to the pooled analysis, a statistically significant association of IL7RA gene rs6897932 SNP with MS risk was found across recessive model (OR= 0.84, 95% CI= 0.77-0.92, P< 0.001, FEM), allelic model (OR= 0.91, 95% CI= 0.85-0.99, P= 0. 02, REM), TT vs. CC model (OR= 0.79, 95% CI= 0.67-0.93, P= 0.005, REM). Moreover, the subgroup analysis based on the ethnicity indicated a negative significant association in Europeans; dominant model (OR= 0.88, 95% CI= 0.78-1.01, P= 0.06, REM), recessive model (OR= 0.79, 95% CI= 0.71-0.88, P< 0.001, REM), allelic model (OR= 0.88, 95% CI= 0.81-0.96, P= 0.003, REM), TT vs. CC model (OR= 0.74, 95% CI= 0.61-0.88, P<0.001, REM) models. Nonetheless, no significant association was detected in Asians and Americans.

CONCLUSIONS

IL7RA gene rs6897932 SNP decreases MS susceptibility in overall population and Europeans.

Single nucleotide vitamin D receptor polymorphisms (FokI, BsmI, ApaI, and TaqI) in the pathogenesis of prematurity complications

The vitamin D receptor (VDR), coded by the VDR gene, plays a pivotal role in executing cellular functions when bound by the active form of vitamin D. Gene polymorphisms in this receptor have been increasingly associated with a heightened state of vulnerability to certain diseases. However, limited data is available concerning the role of VDR gene polymorphisms in preterm infant complications. In 114 premature infants (< 32 weeks gestation) we analyze four single nucleotide VDR polymorphisms (rs2228570 (FokI), rs1544410 (BsmI), rs797532 (ApaI), rs731236 (TaqI)) for their association with respiratory distress syndrome (RDS), intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC) and retinopathy of prematurity (ROP). The results show that BPD was almost four times more likely in infants with the genotype CC of ApaI (rs7975232) (OR 3.845; p = 0.038). While both BPD and NEC were 2.1 times more likely to occur in preterm infants with the allele C of ApaI (rs7975232) (respectively: OR 2.111 and OR 2.129, p < 0.05). The ApaI VDR polymorphism appears to influence incidence of BPD and NEC in preterm infants. Considering VDR polymorphisms in future genetic investigations, in preterm complications, may prove clinically relevant.

Vitamin D receptor gene polymorphisms and the risk of the type 1 diabetes: a meta-regression and updated meta-analysis

BACKGROUND

The association between the polymorphisms in the vitamin D receptor (VDR) gene and the risk of type 1 diabetes mellitus (T1DM) has been evaluated in several studies. However, the findings were inconclusive. Thus, we conducted a meta-analysis to comprehensively evaluate the effect of VDR gene polymorphisms on the risk of T1DM.

METHODS

All relevant studies reporting the association between VDR gene polymorphisms and susceptibility to T1DM published up to May 2020 were identified by comprehensive systematic database search in ISI Web of Science, Scopus, and PubMed/MEDLINE. Strength of association were assessed by calculating of pooled odds ratios (ORs) and 95% confidence intervals (CIs). The methodological quality of each study was assessed according to the Newcastle-Ottawa Scale. To find the potential sources of heterogeneity, meta-regression and subgroup analysis were also performed.

RESULTS

A total of 39 case-control studies were included in this meta-analysis. The results of overall population rejected any significant association between VDR gene polymorphisms and T1DM risk. However, the pooled results of subgroup analysis revealed significant negative and positive associations between FokI and BsmI polymorphisms and T1DM in Africans and Americans, respectively.

CONCLUSIONS

This meta-analysis suggested a significant association between VDR gene polymorphism and T1DM susceptibility in ethnic-specific analysis.

Vitamin D receptor gene polymorphisms and susceptibility to urolithiasis: a meta-regression and meta-analysis

BACKGROUND

The currently available data with respect to the association between vitamin D receptor (VDR) gene polymorphism and risk to urolithiasis are inconclusive and inconsistent. Hence, an exhaustive meta-analysis can solve the discrepancies and provide a hint for upcoming investigations. Herein, a meta-analysis was carried out to attain a conclusive estimate of the association between VDR gene single nucleotide polymorphisms (SNPs) and urolithiasis risk.

METHODS

The major databases, including ISI Web of science, Scopus, and PubMed/MEDLINE were searched systematically from until June 2020 to retrieve all relevant studies. Association between VDR gene polymorphisms, including FokI (rs2228570), TaqI (rs731236), BsmI (rs1544410), and ApaI (rs7975232), and urolithiasis risk was evaluated using pooled odds ratio (OR) and their corresponding 95% confidence interval (CI). Additionally, to seek for the potential source of heterogeneity, meta-regression analyses were exerted.

RESULTS

Literature search led to finally finding of 33 studies evaluating the VDR gene SNPs and urolithiasis risk. It was observed that none of the four SNPs were significantly associated with urolithiasis predisposition. However, subgroup analysis confirmed higher risk of urolithiasis in East-Asian and Caucasian population with ApaI and TaqI gene polymorphism. The analyses of sensitivity acknowledged the results stability.

CONCLUSION

Although this meta-analysis did not support the association of FokI, TaqI, BsmI, and ApaI in the overall polled analysis, it suggests that ApaI and TaqI SNPs is associated with increased risk of urolithiasis in East-Asian and Caucasians populations.

Vitamin D receptor (VDR) gene polymorphism and risk of rheumatoid arthritis (RA): systematic review and meta-analysis

Vitamin D is involved in immune system modulation as well as in calcium and bone homeostasis, hence plays a role in rheumatoid arthritis (RA) etiopathogenesis. A bulk of studies in different populations have assessed the association between the vitamin D receptor (VDR) gene polymorphisms and the risk of RA, reporting conflicting results. Therefore, we designed a meta-analysis to comprehensively evaluate the association of VDR gene polymorphisms and RA risk. All potential studies reporting the association between VDR gene polymorphisms and susceptibility to RA published till February 2020 were retrieved through systematic search of database, including Scopus and MEDLINE. Strength of pooled association was determined through calculating the pooled odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analysis was performed by stratifying the studies by population type. This meta-analysis included 23 eligible studies (21 articles) overall. We noticed that FokI SNP had a significant protective association with susceptibility to RA in the overall analysis as well as in Europeans and Asians. TaqI SNP decreased the RA risk in Africans and Arabs, but not in the overall analysis. Likewise, BsmI SNP and RA risk in the overall population analysis was not significant. Interestingly, BsmI polymorphism increased RA risk in Africans. This meta-analysis offers a significant association between VDR gene polymorphism and susceptibility to RA in both overall and ethnic-specific analysis. However, different polymorphisms acted inversely in increasing or decreasing RA risk in different populations.

Vitamin D's Effect on Immune Function

Ever since its discovery by Windhaus, the importance of the active metabolite of vitamin D (1,25-dihydroxyvitamin D₃; 1,25-(OH)2D₃) has been ever expanding. In this review, the attention is shifted towards the importance of the extra-skeletal effects of vitamin D, with special emphasis on the immune system. The first hint of the significant role of vitamin D on the immune system was made by the discovery of the presence of the vitamin D receptor on almost all cells of the immune system. In vitro, the overwhelming effect of supra-physiological doses of vitamin D on the individual components of the immune system is very clear. Despite these promising pre-clinical results, the translation of the in vitro observations to solid clinical effects has mostly failed. Nevertheless, the evidence of a link between vitamin D deficiency and adverse outcomes is overwhelming and clearly points towards avoidance of vitamin D deficiency especially in early life.