Association Between Vitamin D Receptor Gene Polymorphism rs2228570 and Allergic Rhinitis

Molecular investigation of vitamin D receptor (VDR) genetic variants and their impact on VDR mRNA and serum vitamin D levels in allergic rhinitis in an Indian population: A case-control study

Vitamin D deficiency is widespread and poses a significant health concern, as emerging research links it to allergic diseases owing to its immunomodulatory functions. The optimal functioning of vitamin D and its activation depend on its nuclear receptor, vitamin D receptor (VDR). Genetic variants of VDR have been explored as potential factors in autoimmune and allergic diseases, with limited studies on their association with allergic rhinitis (AR). The present investigation aims to analyse the role of three VDR genetic variants - TaqI, FokI and BsmI - in AR susceptibility and their impact on VDR mRNA and serum vitamin D levels. A total of 550 subjects, consisting of 250 AR cases and 300 age- and gender-matched controls, underwent genotyping by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). VDR mRNA and vitamin D levels were determined by quantitative real-time PCR and chemiluminescence, respectively. Although TaqI did not exhibit significant differences, FokI demonstrated a noteworthy association with AR, particularly with the CC genotype (odds ratio [OR]: 3.34; confidence interval [CI]: 1.79-6.23). Similarly, BsmI revealed an increased risk for AR, with the GA + AA genotypes showing a 2.2-fold elevated risk (OR: 2.20; CI: 1.53-3.16). VDR mRNA expression was threefold lower in AR patients (p < .0001), accompanied by reduced serum vitamin D levels (p < .0001). In addition, CC (p = .01) and AA (p = .02) genotypes of FokI and BsmI were associated with reduced VDR mRNA levels, whereas TaqI showed no such association. Similarly, heterozygous genotypes of TaqI and FokI, as well as homozygous AA of BsmI, correlated with lower serum vitamin D levels (p < .001). This study emphasizes the intricate relationship among VDR genetic variations, altered VDR activity, immune modulation and vitamin D metabolism in AR. Further research involving diverse populations is crucial for confirming and generalizing these findings, paving the way for personalized therapeutic interventions in vitamin D-related disorders.

Vitamin D receptor and vitamin D binding protein gene polymorphisms in patients with asthma: a pilot study

BACKGROUND

The effects of vitamin D are exerted by interaction with the vitamin D receptor (VDR) and vitamin D binding protein (VDBP). Polymorphisms in VDR or VDBP genes may affect vitamin D levels, influencing the pathogenesis of asthma and atopy. The aim of this study was to investigate the possible association of VDR and VDBP gene single-nucleotide polymorphisms (SNP), 25-hydroxyvitamin D (25(OH)D), blood eosinophils and total IgE level in subjects with asthma in comparison with healthy individuals.

METHODS

This case-control study enrolled 63 subjects with asthma (45 allergic and 18 non-allergic) and 32 healthy subjects were involved in the study. Sensitization of subjects to inhaled allergens was determined by a skin prick test, lung function was evaluated by spirometry. Blood eosinophil count was determined by standard methods. Serum 25(OH)D and total IgE levels were evaluated by ELISA. Polymorphisms in the VDR and VDBP genes on the 12q13.11 and 4q13.3 chromosomal region were analyzed using TaqMan SNP Genotyping Assay probes.

RESULTS

In asthma patients with vitamin D deficiency (< 20 ng/ml) the allele G of rs11168293 of VDR was more common than in those having insufficiency (20-30 ng/ml) of vitamin D (63% and 31%, p < 0.05). Moreover, asthmatic subject with rs11168293 G allele has significant higher blood eosinophil count compared to asthmatic without the rs11168293 G allele (8.5 ± 12.3% vs. 5.1 ± 1.5%, p < 0.05). Significantly higher IgE level was found in subjects with allergic asthma with the allele A of rs7041 on VDBP gene than in those without this allele (540 ± 110 and 240 ± 80 IU/ml, p < 0.05).

CONCLUSIONS

The association of polymorphisms in VDBP and VDR gene, the rs11168293 G allele and the rs7041 A allele, with 25(OH)D, blood eosinophil and total IgE level in asthma, let us suggest that vitamin D, VDR and VDBP gene polymorphisms are important in pathogenesis of asthma despite its form in relation to atopy.

Association of vitamin D levels and VDR variant (rs2228570) with allergic rhinitis: A meta-analysis and trial sequential analysis

Background

Allergic rhinitis (AR) is a most common allergic condition characterised by cough, sneezing and flu-like symptoms. The aetiology of AR is not known. A deficiency of vitamin D has been associated with various allergic diseases. The role of vitamin D in allergic rhinitis has been explored in different populations, but the results remained inconsistent. Furthermore, vitamin D exerts its effect through the vitamin D receptor (VDR), and genetic variations in the VDR gene significantly alter vitamin D. We performed a meta-analysis to investigate the role of vitamin D levels and VDR polymorphisms with a predisposition to the development of AR.

Materials and methods

All published articles were searched using databases such as PubMed, Google Scholar, and Science Direct. Based on rigorous inclusion and exclusion, appropriate studies were identified. Vitamin D levels, VDR genotype and allele frequencies were extracted from the eligible reports. The meta-analysis was performed by comprehensive meta-analysis software v3.3.

Results

The present meta-analysis comprised 14 reports with 1504 AR patients and 1435 healthy controls. Compared to healthy controls, AR had significantly lower levels of vitamin D (P = 0.000, standard difference of means = -1.287, 95% CI = -1.921 to -0.652). The meta-analysis of two separate investigations, which included 917 cases and 847 controls, showed no predisposition to allergic rhinitis. The trial sequential analysis also demonstrated the need for future case-control studies of VDR polymorphism to examine their involvement in AR.

Conclusions

Lower vitamin D levels are associated with allergic rhinitis, and vitamin D supplementation might be advantageous in addition to standard treatment. The connection of VDR polymorphism (rs2228570) remained equivocal, and additional research is needed.

Summary

Vitamin D exerct its beneficial effect through the vitamin D receptor (VDR) and role of vitamin D and VDR variant in the allergic rhinitis has been contradictories. We performed a meta-analysis to draw a definitive conclusion of importance of vitamin D and VDR polymorphisms in predisposition to development of allergic rhinitis. The observations of the meta-analysis revealed a significant association of lower vitamin D with allergic rhinitis. In addition the VDR rs2228570 variant predisposed subject to develop rhinitis. Collectively, the results of the present investigation redirect requirement of individualized vitamin D supplementation in the management of allergic rhinitis.

CLEC16A variants conferred a decreased risk to allergic rhinitis in the Chinese population

Background: Allergic rhinitis (AR) is a chronic respiratory disease. Hereditary factors played a key role in the pathogenesis of the AR. This study investigated the association between CLEC16A variants and AR risk in the Chinese population. Methods: We applied Agena MassARRAY technology platform to genotype five single nucleotide polymorphisms (SNPs) located in CLEC16A in 1004 controls and 995 cases. The association between CLEC16A SNPs (rs2286973, rs887864, rs12935657, rs11645657 and rs36045143) and AR risk were calculated by logistic regression analysis, with odds ratio (OR) and 95% confidence interval (CI). False-positive report probability (FPRP) was also used to assess the significant results to reduce false positives. Multifactor dimensionality reduction (MDR) was completed to assess the interaction between CLEC16A variants to predict AR risk. Results: Totally, CLEC16A (rs887864, rs12935657, rs2286973, rs11645657 and rs36045143) were significantly associated with AR risk. Therein, rs2286973, rs11645657 and rs36045143 were related to a decreased risk of AR in the people ≤ 43 years old, females and the people with BMI≤24, respectively. And rs887864 and rs12935657 were also associated with a decreased susceptibility of AR in the people >43 years old. Meanwhile, in the results of region stratification, rs887864 conferred a reduced risk to AR in the people from loess hilly area. Conclusion: CLEC16A variants conferred a decreased risk to AR in the Chinese population.

A Novel Strategy for the Treatment of Allergic Rhinitis: Regulating Treg/Th17 and Th1/Th2 Balance In Vivo by Vitamin D

Objective

This prospective study is aimed at observing the number of nasal itching and sneezing in rats from the macroscopic level and examine the pathological changes of nasal mucosa, Th1 and Th2-related cytokines, and Treg/Th17 by vitamin D3 administration from the microscopic level, in order to explore the role of vitamin D in allergic rhinitis and to provide theoretical guidance for prevention and treatment.

Results

There were significant differences in nasal itching and sneezing between the administration groups and the positive groups. Meanwhile, the level of Th1 and Treg in the administration groups increased, while the level of Th2 and Th17 decreased, indicating that the balance of Th1/Th2 was corrected. Our study revealed that vitamin D3 has preventive and therapeutic effects on allergic rhinitis, which provides theoretical guidance for practical application.

Vitamin D Receptor Gene Polymorphisms and Risk of Atopic Dermatitis in Chinese Han Population

BACKGROUND

Studies investigated the associations between four Vitamin D receptor (VDR) common variations and interactions of gene-environment factors and atopic dermatitis (AD) in Chinese population are few.

METHODS

In this case-control study, 400 AD patients and 400 controls were genotyped for the FokI, TaqI, BsmI and ApalI variations of VDR genes by restriction fragment length polymorphism analysis. The associations between VDR genes and AD were assessed by univariate and multivariate logistic regression. The interactions between VDR genes and some risk factors were also explored using cross-over analysis. The corresponding odds ratio (ORs) and 95% confidence intervals (CI) were also calculated.

RESULTS

The FoKI rs2228570 polymorphism was significantly associated with an increased risk of atopic dermatitis in the co-dominant model (OR=2.93, 95% CI: 1.78-4.82. P=0.000), recessive model (OR=2.67, 95% CI: 1.68-4.26, P=0.000) and dominant model (OR=1.38, 95% CI: 1.04-1.84, P=0.028), and allele model. No significant associations were found among TaqI, BsmI and ApalI polymorphism and AD. The C-A-T-C and C-G-T-T haplotypes significantly increased the risk of atopic dermatitis. For rs2228570, the increased effects were more evident in the subgroups of age ≤8-month, cow milk and mixed, and keeping pet. Interactions between rs2228570 gene polymorphism and family history, age >8, and keeping pet increased the AD risk. The rs2228570 C allele decreased the relative mRNA expression.

CONCLUSION

The FokI rs2228570 C allele of VDR gene could be a risk candidate gene for AD. Interactions between FokI polymorphism and family history and some behaviors may increase the risk of AD.