Vitamin D receptor gene BsmI polymorphism B allele, but not BB genotype, is associated with systemic lupus erythematosus in a Han Chinese population

Role of vitamin D receptor gene polymorphisms and serum 25-hydroxyvitamin D level in Egyptian female patients with systemic lupus erythematosus

Recently, several studies have demonstrated the role of vitamin D receptor (VDR) polymorphisms in the development of systemic lupus erythematosus (SLE). We aimed to evaluate VDR (ApaI, BsmI, and FokI) gene polymorphisms and haplotypes as a risk factors and/or activity markers for SLE, and whether they influence 25-hydroxyvitamin (25(OH) D) level. One hundred and seven SLE patients and 129 controls were enrolled in this study. Disease activity in SLE patients was assessed using Disease Activity Index. Polymorphisms of VDR gene were detected using polymerase chain reaction restriction fragment length polymorphism. Serum 25(OH) D levels were measured using ELISA. We found that ApaI AA genotype, BsmI B allele, Bb, BB genotypes, FokI F allele and FF genotype frequencies of VDR were increased in SLE group. There were significant associations of VDR ApaI AA, BsmI BB, and FokI FF genotypes with lupus nephritis and higher SLE activity scores. Moreover, serum 25(OH) D levels were increased in SLE patients carrying FokI ff genotype compared with patients carrying FF genotype. VDR haplotypes aBF and ABF were associated with SLE risk. The ABF haplotype was associated with higher SLE activity scores and lower serum 25(OH) D concentrations. We observed that the presence of leuko/lymphopenia, renal disorders, higher SLE activity scores and higher anti-dsDNA levels were accompanied by a significant decrease of serum 25(OH)D concentrations. We concluded that The VDR genes polymorphisms, haplotypes, and decreased 25(OH) D levels were associated with risk and more activity scores of SLE.

Vitamin D deficiency and risk for rheumatic diseases: an update

PURPOSE OF REVIEW

The role of vitamin D in situations other than calcium homeostasis and bone health has become very topical. It is apparent that vitamin D has significant effects on the immune system and as such may contribute to the pathogenesis of autoimmune disease. This review examines the evidence-to-date that vitamin D has a role in immune-mediated rheumatic disorders.

RECENT FINDINGS

Low vitamin D status is reported in many inflammatory rheumatic conditions. In some this extends to an association with disease activity. Vitamin D acts on a number of cells involved in both innate and acquired immunity biasing the adaptive immune system away from Th17 and Th1, towards Th2 and Tregs. Deficiency accordingly could encourage autoimmunity. Direct evidence for this plausible mechanism in specific diseases remains largely to be demonstrated. To date, there is a dearth of controlled trials of vitamin D in prophylaxis or therapy.

SUMMARY

Vitamin D deficiency may well be an important factor in autoimmune rheumatic disease, including initial disease development and worsening the disease once present. This is testable and there is a pressing need for therapeutic studies.

Vitamin D Receptor BsmІ Polymorphism and Ovarian Cancer Risk: A Meta-Analysis

Objective

Vitamin D receptor (VDR) FokI polymorphism has been reported to influence ovarian cancer (OC) susceptibility, but the association between VDR BsmI polymorphism and OC risk remains controversial. To clarify the relationship between them, we performed a meta-analysis.

Methods

A comprehensive literature search was conducted to examine all the eligible studies of VDR BsmI polymorphism and OC risk. Odds ratios (OR) with 95% confidence intervals (95% CI) were used to assess the strength of this association.

Results

Seven separate comparisons consisting of 1977 OC cases and 2832 healthy controls were included in our meta-analysis. The pooled analyses showed no significant association between VDR BsmI G/A polymorphism and OC in all of the comparisons (AA vs GG: OR, 1.01; P = 0.919; AG vs GG: OR, 1.12; P = 0.087; AG + AA vs GG: OR, 1.10; P = 0.146; AA vs AG + GG: OR, 0.96; P = 0.629). However, subgroup analysis showed a significant contribution of the dominant inheritance model to OC development in the European group: AG + AA vs GG (OR, 1.43; P = 0.029); AG vs GG (OR, 1.46; P = 0.031).

Conclusions

Vitamin D receptor BsmI G/A gene variant might be a moderate risk factor of OC development in the European population instead of North America or Asian population.

Vitamin D receptor gene BsmI and FokI polymorphisms in relation to ovarian cancer risk in the Polish population

BACKGROUND

The role of vitamin D receptor (VDR) single-nucleotide polymorphisms (SNPs) in ovarian cancer has been studied in various populations; however, these results are discordant between different ethnicities.

METHOD

Using the polymerase chain reaction-restriction fragment length polymorphism method, we studied the prevalence of the VDR FokI (rs2228570) and BsmI (rs1544410) SNPs in women with ovarian cancer (n=168) and controls (n=182) in a Polish population.

RESULTS

We found a significant contribution of the BsmI SNP Bb+BB-versus-bb dominant inheritance model to ovarian cancer development (p=0.0221, p(corr)=0.0442, odds ratio [OR]=1.648 [95% confidence intervals, CI=1.073-2.532]). However, we did not observe an association of the BsmI SNP BB versus Bb+bb recessive inheritance model in patients (p=0.8059, OR=1.093 [95% CI=0.538-2.218]). Moreover, there was no association of FokI SNPs either in Ff+ff versus FF dominant or ff versus Ff+FF recessive inheritance models with ovarian cancer development (p=0.9924, OR=1.002 [95% CI=0.628-1.599] and p=0.1123, OR=1.542 [95% CI=0.901-2.638], respectively). The p-values of the trend test observed for the VDR BsmI and FokI SNPs in patients with ovarian cancer were p(trend)=0.0613 and p(trend)=0.3655, respectively.

CONCLUSION

Our study indicates that the VDR B gene variant might be a moderate risk factor of ovarian cancer development in the Polish population.

Lack of an association between vitamin D receptor BsmI gene polymorphism and the risk of end-stage renal disease: a meta-analysis

OBJECTIVE

To evaluate the association between vitamin D receptor (VDR) BsmI gene polymorphism and the risk of end-stage renal disease (ESRD).

METHODS

All eligible studies were included in our meta-analysis of a search of the PubMed, Embase, Cochrane and China National Knowledge Infrastructure (CNKI) databases according to predefined criteria. The fixed-effects or, in the presence of heterogeneity, random-effects models were used to calculate the pooled odds ratio (OR) and corresponding 95% confidence interval (CI).

MATERIALS

Six studies including 863 patients and 1,063 controls were recruited for the analysis of the association between the VDR BsmI gene polymorphism and the risk of ESRD.

RESULTS

The B allele/BB genotype was not associated with the ESRD risk in the overall population, Caucasians or Asians (overall population: p=0.492 and 0.382, Caucasians: p=0.765 and 0.522, Asians: p=0.607 and 0.481). The Bb/bb genotype was also not associated with the risk of ESRD in the overall population, Caucasians or Asians (overall population: p=0.556 and 0.166, Caucasians: p=0.770 and 0.965, Asians: p=0.411 and 0.098). The exclusion of any single study had little impact on the p value in the overall population. No evidence of publication bias was observed.

CONCLUSION

VDR BsmI gene polymorphism appears to not be associated with the risk of ESRD in the overall population, Caucasians or Asians. However, more studies should be performed in the future.

Vitamin D receptor gene BsmI, FokI, ApaI and TaqI polymorphisms and the risk of systemic lupus erythematosus

Recently, several studies have demonstrated the role of vitamin D receptor (VDR) polymorphisms in the development of systemic lupus erythematosus (SLE); however, these results are inconsistent between different cohorts. Therefore, we studied the prevalence of the VDR FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236) genotypes and alleles in SLE patients (n = 258) and healthy individuals (n = 545) in a Polish population. We did not observe significant differences for either the VDR FokI, BsmI, ApaI and TaqI genotype and allele frequencies in patients with SLE and healthy individuals. However, the frequency of the VDR F/F and F/f genotypes of FokI was statistically different between patients with renal disease and patients without this symptom OR = 3.228 (1.534–6.792, p = 0.0014), p_corr = 0.0476)]. There was no association of the studied VDR BsmI, ApaI and TaqI polymorphisms with clinical manifestations and laboratory profiles in patients with SLE. Our study indicates that the studied VDR FokI variant might increase the risk of some clinical presentations in patients with SLE.

Vitamin D and polymorphisms of VDR gene in patients with systemic lupus erythematosus

The susceptibility for the development of systemic lupus erythematosus (SLE) is related to environmental, hormonal, genetic, and immunological factors. Numerous genes have been linked to the emergence of SLE, including vitamin D receptor (VDR) gene that synthesizes the receptor of vitamin D. Several polymorphisms have been described since the discovery of this gene, and their effects on VDR activity are still poorly understood. Vitamin D's biological functions are mediated by VDR. Vitamin D exerts many actions on the immune system, and several studies have suggested its role in the pathogenesis of autoimmune diseases. SLE patients have low blood levels of vitamin D, which raises the possibility of association between the deficiency of this vitamin and the onset of the disease. BsmI and FokI polymorphic variants seem to be related to the onset of the disease in Asian patients. In this article, we review the aspects related to the metabolism and immunoregulatory effects of vitamin D, VDR, and main polymorphisms involving the VDR gene and the relationship between vitamin D levels and its receptor with SLE.

Bone mass and biochemical markers of bone turnover in children and adolescents with chronic immune thrombocytopenia: relation to corticosteroid therapy and vitamin D receptor gene polymorphisms

Optional drug therapy in refractory chronic immune thrombocytopenia (ITP) includes standard oral, pulsed high-dose steroid therapy, intravenous gamma globulin, anti-D, and immunosuppressive therapy or thrombopoietin receptor agonists. This work aimed to study the bone mass in children and adolescents with chronic ITP in relation to biochemical markers of bone turnover, cumulative steroid therapy, and the possible modulating effect of vitamin D receptor (VDR) gene polymorphisms. Thirty-six children and adolescents with chronic ITP were recruited from the Hematology Clinic, Children's Hospital, Ain Shams University and the Hematology Clinic of the National Research Centre in Egypt and compared with 43 healthy age- and sex-matched controls. The total cumulative dose of steroids was calculated. Bone markers (serum osteocalcin (OC) and propeptide I precollagen (PICP) and urinary deoxypyridinoline (DPD) excretion), analysis of VDR gene distribution, and dual energy X-ray absorptiometry at lumbar and hip regions were performed for patients and controls. Compared to controls, chronic ITP patients had higher body mass index (BMI) and lower height for age standard deviation score (SDS). Chronic ITP patients had lower levels of OC and C-terminal propeptide of type I procollagen (PICP) and higher urinary DPD excretion, and bone mineral density (BMD) was significantly lower for both spine and hip z-score (<0.001). BMD was inversely correlated with urinary DPD excretion, age, BMI, and cumulative steroid dose. There was significant negative correlation between cumulative oral steroid dose and BMD (r = -0.4, P = 0.01 and r = -0.45, p = 0.001 for spine and hip z-scores, respectively), but the correlation was non-significant in relation to cumulative pulsed steroid therapy. FokI polymorphism was significantly related to BMD for both spine and hip z-score (p = 0.015 and p = 0.008, respectively), but there was no relation between BMD and Bsm1 polymorphism. FokI gene polymorphism may be one of the contributing factors in bone loss in patients on chronic steroid therapy. High cumulative doses of corticosteroids increased bone resorption in young chronic ITP patients. Longitudinal studies are needed to confirm the effect of different steroid protocols on bone turnover. Protocols of therapy of chronic ITP should restrict corticosteroid use in growing children and favor alternative less harmful therapies.