The role of vitamin D in 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.

The association between nasal mucosa bacteria and serum metals in children with nasal diseases

Allergic rhinitis (AR) and adenoid hypertrophy (AH) are common nasal diseases in children. Studies have shown that heavy metals are environmental risk factors for nasal diseases, and the pathogenic mechanisms may be related to dysregulation of nasal mucosal microbiota. However, it is unclear how heavy metal exposure relates to the nasal mucosal microbiota in nasal diseases. Therefore, we explored serum metal exposure levels and nasal mucosal microbiota composition in children with different nasal disease, and further studied the potential correlation between metal exposure and disease-related taxa. There were 64 children recruited for this study. The 23 metals concentrations in serum were measured by inductively coupled plasma mass spectrometry, and nasal mucosal bacteria was identified by 16S rRNA sequencing. Nasal diseases (AR and AH) in children were associated with alterations in the abundance and diversity of the nasal mucosal microbiota. The nasal microbiota of children with AR showed lower diversity, while the microbiota of children with AH showed higher diversity. Linear discriminant analysis Effect Size showed 108 differentially abundant taxa between AR and control groups, 35 differentially abundant taxa among large adenoid, moderate adenoid and small adenoid groups. The serum zinc concentration was negatively correlated with Pielou's eveness index and Simpson's Index in children classified by adenoid size. The spearman correlation analysis showed that multiple disease-related taxa were closely associated with metal concentrations in serum. Our findings may support a link between metal exposure and the diversity and composition of nasal bacteria in children with nasal disease, which present new evidence for the effects of metals on children health.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

A Clinical Study to Evaluate the Role of Vitamin D3 in Allergic Rhinitis

Allergic rhinitis is a common and chronic immunoglobulin E-mediated inflammation of nasal mucosa induced after allergen exposure. Allergic rhinitis is a global health problem that causes major illness and affects patient's social life, sleep, school and work performance. Various studies have implicated the association between low serum vitamin D levels and allergic diseases. Active form of Vitamin D3 has been shown to have immunoregulatory effect on both innate and adaptive immunity, which can significantly affect the outcome of allergic responses in allergic rhinitis. The study aims to evaluate effectiveness of Oral Vitamin D3 supplementation as an adjunct to standard therapy, in the management of allergic rhinitis. The present study is a prospective study in which 80 subjects were recruited and were randomly divided into two groups. The study group received oral vitamin D3 (60,000 IU) along with intranasal steroid spray while control group received only intranasal steroid spray for 4 weeks. The response in both the groups was compared by evaluating total nasal symptom score (TNSS). Subjects of allergic rhinitis showed deficiency in vitamin D indicated by mean serum vitamin D levels of 15 ± 2.42 ng/ml in the study group and 14.72 ± 2.64 ng/ml in the control group. The pre treatment mean TNSS score was 10.45 ± 3.1 in the study group and 11.43 ± 2.35 in the control group. The post treatment mean TNSS score was 2.1 ± 0.21 in the study group and 3.85 ± 0.76 in the control group. A significant reduction in symptoms score was observed after 4 weeks of oral vitamin D3 supplementation. The difference between two groups was found to be statistically significant (p value < 0.05).

Changes in Vitamin D Status in Korean Adults during the COVID-19 Pandemic

The aim of this study was to investigate changes in 25(OH)D (25-hydroxyvitamin D) levels and in the vitamin D status of Korean adults before and during the coronavirus disease (COVID-19) pandemic. This study compared serum 25(OH)D levels before and after the pandemic in 1483 adults aged 19 years and older who were screened at a university hospital. Subjects were selected only from participants tested in the same season before and after the pandemic. The pre-COVID-19 testing period was from 1 March 2018 to 31 November 2019; the testing period in the COVID-19 era was from 1 June 2020 to 31 November 2021. The mean 25(OH)D level for all participants was 21.4 ± 10.2 ng/mL prior to the outbreak of COVID-19, which increased to 23.6 ± 11.8 ng/mL during the COVID-19 lockdown period (p < 0.001). The increase was particularly dramatic in elderly females (28.8 ± 12.3 ng/mL to 37.7 ± 18.6 ng/mL, p = 0.008). The prevalence of vitamin D deficiency decreased in both males (48.4% to 44.5%, p = 0.005) and females (57.0% to 46.0%, p < 0.001). In conclusion, 25(OH)D levels in Korean adults increased during the COVID-19 era, and the prevalence of vitamin D deficiency decreased accordingly.

TLR Signaling Pathway Gene Polymorphisms, Gene-Gene and Gene-Environment Interactions in Allergic Rhinitis

Background

Allergic rhinitis (AR) is a nasal inflammatory disease resulting from a complex interplay between genetic and environmental factors. The association between Toll-like receptor (TLR) signaling pathway and environmental factors in AR pathogenesis remains to be explored. This study aims to assess the genetic association of AR with single nucleotide polymorphisms (SNPs) in TLR signaling pathway, and investigate the roles of gene–gene and gene–environment interactions in AR.

Methods

A total of 452 AR patients and 495 healthy controls from eastern China were enrolled in this hospital-based case–control study. We evaluated putatively functional genetic polymorphisms in TLR2, TLR4 and CD14 genes for their association with susceptibility to AR and related clinical phenotypes. Interactions between environmental factors (such as traffic pollution, residence, pet keeping) and polymorphisms with AR were examined using logistic regression. Models were stratified by genotype and interaction terms, and tested for the significance of gene–gene and gene–environment interactions.

Results

In the single-locus analysis, two SNPs in CD14, rs2563298 (A/C) and rs2569191 (C/T) were associated with a significantly decreased risk of AR. Compared with the GG genotype, the GT and GT/TT genotypes of TLR2 rs7656411 (G/T) were associated with a significantly increased risk of AR. Gene–gene interactions (eg, TLR2 rs7656411, TLR4 rs1927914, and CD14 rs2563298) was associated with AR. Gene–environment interactions (eg, TLR4 or CD14 polymorphisms and certain environmental exposures) were found in AR cases, but they were not significant after Bonferroni correction.

Conclusion

The genetic polymorphisms of TLR2 and CD14 and gene–gene interactions in TLR signaling pathway were associated with susceptibility to AR in this Han Chinese population. However, the present results were limited to support the association between gene–environment interactions and AR.

The beliefs about allergic rhinitis and its treatment options from people in Central Thailand

Background

Allergic rhinitis (AR) has substantially negative impacts on patients' quality of life. Besides conventional medicines, many patients use alternative approaches, which sometimes were misconception.

Objective

This study aims to explore and compare the beliefs about AR and its treatment options between 2 different groups; control and AR patient groups.

Methods

A cross-sectional study of 518 respondents residing in the central region of Thailand has been conducted using a self-reported questionnaire which consists of 3 parts; personal profile, the International Study of Asthma and Allergies in Childhood (ISAAC) questions, and the beliefs. ISAAC is applied for identifying respondents as the control or the AR group.

Results

From a total of 518 respondents, 311 (60.0%) were identified as the AR group. The demographic data between the control and the AR group has no statistical difference (p > 0.05). Regarding the beliefs about AR characteristics, 56.1% of the AR group believe that low immunity causes AR while the number of the control group reaches 56%. Thirty-nine point two percent for the AR group and 38.6% for the control group believe that AR is a fatal disease. The belief that AR can be spread by droplet/airborne transmission is 22.8% and 28.5% for the AR and the control group, respectively. About AR treatment options, 60.1% of the AR group and 43% of the control group believe that taking vitamin C can relieve AR symptoms, which has a statistical difference (p < 0.05) between the 2 groups. The belief that prolonged use of antihistamine drugs can cause drug resistance is 29.9% and 24.6% for AR and control groups, respectively.

Conclusion

Both groups of respondents mostly share common beliefs about AR characteristics and treatment options in which the AR group has higher percentage in some beliefs. Therefore, health literacy should be promoted in order to improve patient's care.

Systemic and local cytokine profile and risk factors for persistent allergic airway inflammation in patients sensitised to house dust mite allergens

Objective

To evaluate cytokine profile, vitamin D status, symptom score and quality of life in patients with persistent allergic airway diseases sensitised to house dust mites (HDM) in comparison with healthy individuals.

Material and methods

Patients sensitized to HDM with persistent AR and having symptoms for at least 2 years with or without AA were involved into the study. Measurements of vitamin D level in serum and IL-10, IL-13, IL-17, IL-22, IL-33 and IFN-gamma in serum and nasal lavage were performed by ELISA.

Results

Eighty-one subjects were involved into the study. Serum IL-10 concentration was higher in patients with AR than in patients with AR and AA (6.71 ± 1.73 vs. 1.98 ± 0.24, p < 0.05). IFN-gamma level in nasal lavage was higher in patients with AR and AA than in patients with AR (p < 0.01) and healthy individuals (p < 0.05) (7.50 ± 0.37 vs. 6.80 ± 0.99 vs. 6.50 ± 0.22). Serum IL-22 negatively correlated with IL-22 in nasal lavage, whereas serum IFN-gamma positively correlated with IFN-gamma in nasal lavage. Positive correlation between serum IL-17 and total IgE and negative correlation between IL-17 in nasal lavage and eosinophils in nasal smear were found in patients with AR and AA. Serum IFN-gamma decreased the risk of AR for healthy individuals. Serum IL-10 and vitamin D decreased risk for development of AA for patients with AR. IL-22 in serum and IL-10 and IL-33 in nasal lavage increased this risk.

Conclusion

Novel cytokines such as IL-22, IL-17 and IL-33 and vitamin D may be involved in pathogenesis of persistent airway inflammation in patients sensitized to HDM.

The Effect of Serum Vitamin D Level on Allergic Rhinitis Symptoms in Children

Background: Allergic rhinitis (AR) is a chronic disease that is becoming increasingly common worldwide and has a negative impact on school performance, work performance, and quality of life. The aim of this study was to investigate the effect of vitamin D on the symptoms of AR in children. Methods: Serum vitamin D levels of children with AR and age-matched healthy controls were compared using the high-pressure liquid chromatography method. The relationship between serum vitamin D levels and symptoms and severity of AR was then examined. Results: The study included 137 patients diagnosed with AR (76 males, 61 females; median age: 11 years). Serum vitamin D levels were lower in the patient group than in the control group (P = 0.001), lower in all aeroallergen groups (mites, pollen, and multiple inhalants) than in the healthy control group (P = 0.001), and lower in both the perennial AR group and the seasonal AR group than in the control group (P = 0.001). Spearman correlation analysis showed that there was no correlation between symptom score and vitamin D level (r_s = -0.099; P = 0.25). Conclusions: We found no correlation between serum vitamin D level and symptoms and severity of AR. Serum vitamin D levels were lower in children with AR than in healthy children.

Upregulation of the Vitamin D Receptor in the Nasal Mucosa of Patients With Allergic Rhinitis

Background and Objectives: Vitamin D modulates immunity, including that of allergic diseases, and plays its roles through contact with vitamin D receptors (VDR). Recent studies have shown that patients with allergic rhinitis have low systemic serum vitamin D level. However, the expression of VDR in local tissue such as human nasal mucosa has not been investigated. Our study demonstrated that, in nasal mucosa of normal controls and patients with allergic rhinitis.Materials and Methods: Nasal mucosa were harvested from twenty-five patients who had normal nasal mucosa and twenty-five patients with allergic rhinitis. After the total RNA isolation, we performed reverse transcriptase-polymerase chain reaction, immunohistochemical staining and western blot analysis.Results: VDR were expressed in submucosal glands and the superficial layer of epithelial cell, and that inflammatory cells are expressed more highly in the nasal mucosa of patients with allergic rhinitis compared to those without. In the mucosa of patients with allergic rhinitis, VDR expression level was upregulated compared to that in normal nasal mucosa.Conclusion: This findings suggest that VDR plays a role in the pathogenesis of allergic rhinitis. Additional research is needed to determine the mechanism and consequences of VDR upregulation.

Allergic Rhinitis: What Do We Know About Allergen-Specific Immunotherapy?

Allergic rhinitis (AR) is an IgE-mediated disease that is characterized by Th2 joint inflammation. Allergen-specific immunotherapy (AIT) is indicated for AR when symptoms remain uncontrolled despite medication and allergen avoidance. AIT is considered to have been effective if it alleviated allergic symptoms, decreased medication use, improved the quality of life even after treatment cessation, and prevented the progression of AR to asthma and the onset of new sensitization. AIT can be administered subcutaneously or sublingually, and novel routes are still being developed, such as intra-lymphatically and epicutaneously. AIT aims at inducing allergen tolerance through modification of innate and adaptive immunologic responses. The main mechanism of AIT is control of type 2 inflammatory cells through induction of various functional regulatory cells such as regulatory T cells (Tregs), follicular T cells (Tfr), B cells (Bregs), dendritic cells (DCregs), innate lymphoid cells (IL-10⁺ ILCs), and natural killer cells (NKregs). However, AIT has a number of disadvantages: the long treatment period required to achieve greater efficacy, high cost, systemic allergic reactions, and the absence of a biomarker for predicting treatment responders. Currently, adjunctive therapies, vaccine adjuvants, and novel vaccine technologies are being studied to overcome the problems associated with AIT. This review presents an updated overview of AIT, with a special focus on AR.

Vitamin D receptor gene polymorphisms in atopy

Background

The occurrence of allergic conditions, for example allergic asthma, rhinitis, and atopic dermatitis, is rising worldwide. These allergic conditions are associated with poor life quality. Vitamin D is proposed to be linked with increased risk and severe forms of allergic diseases.

Aims

This review article aimed to evaluate the vitamin D level role and polymorphisms of vitamin D receptor gene (VDR) in atopy.

Methods & Materials

We analyzed publications that were focusing on levels of vitamin D and/or polymorphism analysis of vitamin D receptor gene in allergic asthma, rhinitis, and atopic dermatitis patients.

Results

We noticed that levels of vitamin D are extensively studied in atopy by many research groups, however, polymorphisms of vitamin D receptor gene and their link with levels of vitamin D lack comprehensive data. There is evidence that vitamin D may be associated with anti‐inflammatory effects in allergic diseases. Some of VDR polymorphisms also may play a role in pathogenesis of these diseases. However, the data from different studies are controversial.

Discussion

The results of different studies are usually inconsistent, most probably due to populational bias or differences in methodology. Even though, more evidence shows a positive impact of vitamin D on the risk and outcomes of allergic diseases, especially atopic dermatitis, and asthma.

Conclusions

There is controversial data about the level of vitamin D and its role in atopy; however, more evidence shows a positive impact on the risk and outcomes of allergic diseases.

Role of Vitamin D in the Clinical Course of Nasal Polyposis

Vitamin D is a lipo-soluble hormone well known for its effects on calcium homeostasis and bone metabolism. Recently, there has been growing interest in the extraskeletal effects of vitamin D. In particular, recent studies have highlighted how vitamin D plays a fundamental role in immunomodulation processes in the context of both innate and adaptive immunity, with consequent anti-inflammatory and anti-oxidant effect in different immune-mediated pathologies, such as systemic sclerosis, psoriasis, atopic dermatitis and rheumatoid arthritis; as well as in various pro-inflammatory processes affecting the airways, including chronic rhinosinusitis with (CRSwNP) or without (CRSsNP) nasal polyposis. We analyze the role of vitamin D in the genesis and progression of CRSwNP/sNP and its supplementation as a safe and valid therapeutic strategy capable of improving the clinical outcome of standard therapies.

The Association of Prenatal Vitamin D Sufficiency With Aeroallergen Sensitization and Allergic Rhinitis in Early Childhood

BACKGROUND

The role of prenatal vitamin D sufficiency and supplementation in the development of childhood aeroallergen sensitization and allergic rhinitis remains uncertain.

OBJECTIVE

To describe the association of prenatal vitamin D sufficiency with childhood allergic outcomes in participants of the Vitamin D Antenatal Asthma Reduction Trial, a randomized controlled trial of prenatal vitamin D supplementation.

METHODS

We included 414 mother-offspring pairs with offspring aeroallergen sensitization data available at age 6 years in this analysis. We examined the association between prenatal vitamin D sufficiency status, based on vitamin D levels measured in the first and third trimesters, or vitamin D supplementation treatment assignment with the outcomes of aeroallergen sensitization, parent-reported clinical allergic rhinitis, parent-reported clinical allergic rhinitis with aeroallergen sensitization, food sensitization, any sensitization, eczema, and total IgE at ages 3 and 6 years.

RESULTS

Compared with early and late insufficiency, early prenatal vitamin D insufficiency with late sufficiency was associated with reduced development of clinical allergic rhinitis with aeroallergen sensitization at 3 years (adjusted odds ratio [aOR] = 0.34; 95% confidence interval [CI], 0.13-0.82; P = .02) and 6 years (aOR = 0.54; 95% CI, 0.29-0.98; P = .05). At 6 years, clinical allergic rhinitis with sensitization was significantly decreased in offspring whose mothers received high-dose vitamin D (aOR = 0.54; 95% CI, 0.32-0.91; P = .02) compared with offspring whose mothers who received low-dose vitamin D. Associations of prenatal vitamin D with aeroallergen sensitization were strengthened among children who also developed asthma or who had a maternal history of atopy.

CONCLUSIONS

Among mothers with first-trimester vitamin D insufficiency, we detected a protective effect of third-trimester prenatal vitamin D sufficiency on the development of clinical allergic rhinitis with aeroallergen sensitization at ages 3 and 6 years.

Double-Edged Sword of Vitamin D3 Effects on Primary Neuronal Cultures in Hypoxic States

The use of vitamin D3 along with traditional therapy opens up new prospects for increasing the adaptive capacity of nerve cells to the effects of a wide range of stress factors, including hypoxia-ischemic processes. However, questions about prophylactic and therapeutic doses of vitamin D3 remain controversial. The purpose of our study was to analyze the effects of vitamin D3 at different concentrations on morpho-functional characteristics of neuron-glial networks in hypoxia modeling in vitro. We showed that a single administration of vitamin D3 at a high concentration (1 µM) in a normal state has no significant effect on the cell viability of primary neuronal cultures; however, it has a pronounced modulatory effect on the functional calcium activity of neuron-glial networks and causes destruction of the network response. Under hypoxia, the use of vitamin D3 (1 µM) leads to total cell death of primary neuronal cultures and complete negation of functional neural network activity. In contrast, application of lower concentrations of vitamin D3 (0.01 µM and 0.1 µM) caused a pronounced dose-dependent neuroprotective effect during the studied post-hypoxic period. While the use of vitamin D3 at a concentration of 0.1 µM maintained cell viability, preventive administration of 0.01 µM not only partially preserved the morphological integrity of primary neuronal cells but also maintained the functional structure and activity of neuron-glial networks in cultures. Possible molecular mechanisms of neuroprotective action of vitamin D3 can be associated with the increased expression level of transcription factor HIF-1α and maintaining the relationship between the levels of BDNF and TrkB expression in cells of primary neuronal cultures.

Vitamin D and Immunoglobulin E Status in Allergic Rhinitis Patients Compared to Healthy People

Allergic rhinitis (AR) is a type of inflammatory condition that includes a group of symptoms, mainly affecting the nasal mucosa. Nasal obstruction, sneezing, stuffy or runny nose, in addition to swollen, itchy, red and watery eyes are the most common symptoms of the disease. These symptoms are triggered as a result of increased inflammatory mediators such as histamine and leukotrienes. Studies have recently shown the role of vitamin D (vit.D) in many allergic and immune conditions, where receptors for the active form of vit.D (1,25-dihydroxyvitamin D3) have been discovered on the surface of almost all types of inflammatory cells. Therefore, the present study was conducted to explore the level of vit. D in AR patients and its correlation with the severity of the disease. Two groups participated in the study; the first group included 49 patients who were diagnosed in a private otolaryngology clinic by the first author as having allergic rhinitis (AR group). The second one served as a control group and included 50 apparently healthy volunteers with no history of AR. The mean level of IgE and vit. D was found to be 326.3 and 10.2 ng/ml in the AR group, respectively, and 30.8 and 23.3 ng/ml in the control group, respectively. Ninety-three percent of AR patients have shown a deficiency in vit. D level, where 56% of this group showed severe deficiency. On the other hand, 34% of the control group has shown an insufficient level of vit. D. Additionally, 64% of AR patients have shown serum levels of IgE at values ranging between 100-299 ng/ml. Higher serum levels of IgE at values ranging between 300-599 ng/ml and 600-1000 ng/ml were observed in 25% and 11% of AR patients, respectively. The prevalence of low levels of vit. D in the AR group was significantly higher than that in the control group (P < 0.001). Vit. D deficiency is significantly related to severe AR symptoms and measuring serum vit. D level is recommended in the management plan of this group of patients.

Association of Serum Vitamin D and Immunoglobulin E Levels With Severity of Allergic Rhinitis

Objective The aim of this study was to determine the association of serum vitamin D and immunoglobulin E (IgE) levels with the severity of allergic rhinitis (AR). Methods This case-control study was conducted at Mayo Hospital, Lahore, from June to September 2020 after obtaining ethical approval. Patients of AR were included and divided with the help of allergic rhinitis and its impact on asthma (ARIA) classification, into group A (cases), patients presenting with moderate to severe symptoms, and into group B (control), patients with mild symptoms, after treatment of AR. The mean difference between serum IgE and serum Vitamin D levels of both groups were compared by t-test. Association was determined by logistic regression and odds ratio. Results A total of 224 patients were included in the study, 112 patients in group A and 112 patients in group B. There were 106 (47.3%) female and 118 (52.7%) male. The mean age of patients in group A was 26.78± 8.92 years and in group B, it was 25.72±8.12 years. Mean serum vitamin D levels in group A were 16.24±6.7 ng/ml and in group B 26.92±35 ng/ml (p=0.0001). Mean serum IgE levels in group A were 383.69±154.86 IU/ml and in group B, they were 373.03±106.83 IU/ml (p=0.0001). Vitamin D deficient patients were 24 times more likely to develop moderate to severe AR disease. Conclusion This study showed that in moderate-severe AR, IgE levels are raised statistically as compared to mild AR and the deficiency of Vitamin D is associated with increasing severity of allergic rhinitis symptoms.

Null association between serum 25-hydroxyvitamin D levels with allergic rhinitis, allergic sensitization and non-allergic rhinitis: A Mendelian randomization study

BACKGROUND

Previous observational studies have not found a conclusive association between serum 25-hydroxyvitamin D (25(OH)D) levels and allergic rhinitis (AR) or allergic sensitization (AS).

OBJECTIVE

To investigate a causal association between 25(OH)D levels with risk of AR and AS, using a two-sample Mendelian randomization (MR) approach.

METHODS

Seven single nucleotide polymorphisms (SNPs), previously shown to be associated with serum 25(OH)D levels, were identified as instrumental variables. The primary outcome was AR, and the secondary outcomes were AS and non-allergic rhinitis (NAR). The genome-wide association (GWA) summary statistics of the outcomes were obtained from two cohort studies (EAGLE Consortium and UK Biobank). An MR analysis with random-effects inverse-variance weighted method was performed as the primary analysis to estimate overall effect size (odds ratio [OR] and 95% confidence interval [CI]). Sensitivity analysis using weighted median method and MR-Egger regression method was conducted. A subgroup analysis based on 25(OH)D synthesis-related SNPs was further applied.

RESULTS

Serum 25(OH)D levels were not causally associated with risk of AR (OR: 0.960; 95% CI: 0.779-1.184), AS (OR: 1.059; 95% CI: 0.686 to 1.634) or NAR (OR: 0.937; 95% CI: 0.588-1.491). Subgroup analysis also showed null association between 25(OH)D synthesis-related SNPs and the outcomes. Sensitivity analyses yielded similar results.

CONCLUSIONS AND CLINICAL RELEVANCE

This MR study found no evidence supporting a causal association between serum 25(OH)D levels and risk of AR, AS and NAR in European-ancestry population. This argues against the previous postulation that vitamin D supplementation is effective in prevention of allergic diseases.

Vitamin D Status in Egyptian Children With Allergic Rhinitis

Objective: This study aimed to assess the serum levels of vitamin D in an Egyptian cohort of children with allergic rhinitis (AR) and to evaluate any correlation of vitamin D status with the disease severity. Patient and methods: One hundred twenty children with AR and 100 healthy children were included in our study. We studied the serum levels of vitamin D 25(OH)D and 1,25(OH)2D in all participants. The associations between vitamin D levels and clinical characteristics of AR were examined. Results: In AR group, the serum levels of calcium, (25(OH)D and 1,25(OH)2D levels were significantly lower (p < .0001, p < .001, and p < .0001, respectively) in AR children than in controls. Furthermore, the mean 25-OHD3 levels in patients with moderate/severe AR were significantly lower than those with mild AR (p < .001). We found significant negative correlations between mean 25(OH)D levels and total nasal symptom score (r = -.62, p = .002) and total immunoglobulin E levels (r = -.27, p = .013) in AR group. Conclusions: Vitamin D deficiency is a frequent finding among Egyptian children with AR when compared to the healthy group. A significant inverse association was observed between vitamin D levels and AR disease severity.

Association Between Vitamin D Receptor Gene Polymorphism rs2228570 and Allergic Rhinitis

Background

Vitamin D receptor (VDR) gene polymorphisms are involved in a variety of immune-related diseases, and VDR is associated with allergic rhinitis. The present study explored the associations between VDR gene polymorphisms and allergic rhinitis in the Chinese population.

Methods

The study population consisted of 400 patients with allergic rhinitis and 400 healthy controls. General characteristics were determined by interview. Blood DNA was extracted and genotyping was performed via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The associations of each genetic variant with risk for AR were assessed by calculating the odds ratio (OR) with 95% confidence interval (95% CI).

Results

No significant differences were observed in general characteristics between cases and controls. The distributions of genotypes at the rs2228570 locus of the VDR gene conformed to Hardy–Weinberg equilibrium. There was a significant difference in the distribution of rs2228570 genotype (P<0.001) between cases and controls. Compared to GG and GA genotypes, the AA genotype increased the risk of AR (OR=3.27, 95% CI: 2.10–5.11, P=0.000; OR=2.58, 95% CI:1.63–4.08, P<0.001). Similar results were also observed in the dominant model (OR=1.64, 95% CI:1.24–2.17, P<0.001) and codominant model (OR=2.95, 95% CI:1.93–4.51, P<0.001). The A allele was still associated with elevated risk gene for AR after adjusting for potential confounding factors. Subgroup analyses indicated an interaction between alcohol and rs2228570 in the risk of allergic rhinitis. The A allele also increased the risk for AR in the population without asthma (OR=1.85, 95% CI:1.46–2.34, P<0.001).

Conclusion

VDR gene polymorphism is associated with AR, and the AA genotype of rs2228570 is associated with the increased risk of AR in the Chinese population.

Association of vitamin D genetic pathway with asthma susceptibility in the Kurdish population

BACKGROUND

Vitamin D (Vit D) function in asthma progression has been studied well. The effects of genetic variations in Vit D pathway molecules have been also studied, although the results are contradicted. In the present study, for the first time we examined the Vit D pathway molecules included serum Vit D and vitamin D-binding protein (VDBP) and also genetic variations in the vitamin D receptor (VDR) and VDBP in a Kurdish population with asthma.

METHODS

An enzyme-linked immunosorbent assay (ELISA) method was used to measure the serum Vit D and VDBP. VDR rs1544410 and rs2228570 and VDBP rs7041 were assessed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

The serum level of Vit D significantly decreased in asthmatic patients versus controls (16.26 ± 6.76 vs 23.05 ± 10.57 ng/mL, P value = .001). We observed an indirect correlation between Vit D and clinical findings. We also found an increased level of serum VDBP in patients as compared to the controls (1044.6 ± 310.82 vs 545.95 ± 121.73 µg/mL, P value < .0001). Besides, the risk of asthma progression was increased in patients with the VDR rs2228570 CC and VDBP rs7041 GG genotypes (OR = 3.56, P = .0382 and OR = 2.58, P = .01, respectively).

CONCLUSION

In summary, our results explain the influence of the genetic variations in VDR and VDBP in addition to Vit D and VDBP serum concentrations on asthma susceptibility in the Kurdish population.

Vitamin D and Serum Immunoglobulin E Levels in Allergic Rhinitis: A Case-control Study from Pakistan

Introduction

Allergic rhinitis (AR) is the most common non-infectious rhinitis and is associated with sneezing, cough, and flu-like symptoms. The exact pathophysiology of AR remains uncertain. The deficiency of vitamin D₃ has been documented as a probable cause of allergic conditions due to its role in immunomodulation. The aim of this study was to evaluate the role of vitamin D₃ deficiency in allergic rhinitis.

Methods

This case-control study was conducted with 50 patients of AR and 50 healthy individuals. Serum immunoglobulin (Ig) E and vitamin D₃ levels were measured in all study participants. Data were analyzed using SPSS v. 21.0 (IBM Corp., Armonk, NY).

Results

Mean serum IgE levels in the AR group were 553.5 ± 53.9 IU/L as compared to 219.4 ± 32.1 IU/L in the control group (p <0.0001). AR patients had mean serum vitamin D levels of 14.8 ± 7.4 ng/mL as compared to 19.1 ± 6.6 ng/mL in the control group (p=0.002). Only 10% of participants in the AR group had adequate serum vitamin D levels as compared to 26% in the controls (p=0.08).

Conclusion

Vitamin D deficiency was present in both study groups. The AR group had significantly lower mean levels of serum vitamin D than the control group. However, upon stratification, the differences were insignificant.

The Impact of Serum 25-Hydroxyvitamin D3 Levels on Allergic Rhinitis

We aimed to clarify the relation between allergic rhinitis and the serum levels of 25-hydroxivitamin D in the adult population. The study group consisted of 86 patients with allergic rhinitis who were diagnosed with the help of history of allergy, positive signs for allergy, blood samples, and positive skin prick tests; while the control group included 43 age- and sex-matched healthy volunteers with negative skin prick tests. The demographic data, medical history, findings in the physical examinations, serum levels of total immunoglobulin E (IgE) and 25-hydroxyvitamin D, and skin prick test results of the groups were noted. A total of 129 patients fulfilling the necessary criteria were enrolled. The median serum 25-hydroxyvitamin D levels in the study group were significantly lower compared to the control group ( P = .014). In the study group, median serum vitamin D levels were significantly higher in men, compared to women ( P = .03). There was a significant negative correlation between IgE and vitamin D levels in the allergic rhinitis group ( P = .028, r = −0.246). This study showed that patients with allergic rhinitis might be more vulnerable to have lower serum levels of vitamin D. Thus, vitamin D supplementation as an adjunctive therapy may be considered in those patients.

Identification of Novel Biomarkers for Drug Hypersensitivity After Sequencing of the Promoter Area in 16 Genes of the Vitamin D Pathway and the High-Affinity IgE Receptor

The prevalence of allergic diseases and drug hypersensitivity reactions (DHRs) during recent years is increasing. Both, allergic diseases and DHRs seem to be related to an interplay between environmental factors and genetic susceptibility. In recent years, a large effort in the elucidation of the genetic mechanisms involved in these disorders has been made, mostly based on case-control studies, and typically focusing on isolated SNPs. These studies provide a limited amount of information, which now can be greatly expanded by the complete coverage that Next Generation Sequencing techniques offer. In this study, we analyzed the promoters of sixteen genes related to the Vitamin D pathway and the high-affinity IgE receptor, including FCER1A, MS4A2, FCER1G, VDR, GC, CYP2R1, CYP27A1, CYP27B1, CYP24A1, RXRA, RXRB, RXRG, IL4, IL4R, IL13, and IL13RA1. The study group was composed of patients with allergic rhinitis plus asthma (AR+A), patients with hypersensitivity to beta-lactams (BLs), to NSAIDs including selective hypersensitivity (SH) and cross-reactivity (CR), and healthy controls without antecedents of atopy or adverse drug reactions. We identified 148 gene variations, 43 of which were novel. Multinomial analyses revealed that three SNPs corresponding to the genes FCER1G (rs36233990 and rs2070901), and GC (rs3733359), displayed significant associations and, therefore, were selected for a combined dataset study in a cohort of 2,476 individuals. The strongest association was found with the promoter FCER1G rs36233990 SNP that alters a transcription factor binding site. This SNP was over-represented among AR+A patients and among patients with IgE-mediated diseases, as compared with control individuals or with the rest of patients in this study. Classification models based on the above-mentioned SNPs were able to predict correct clinical group allocations in patients with DHRs, and patients with IgE-mediated DHRs. Our findings reveal gene promoter SNPs that are significant predictors of drug hypersensitivity, thus reinforcing the hypothesis of a genetic predisposition for these diseases.

Impact of Allergic Rhinitis on Nasal Mucociliary Clearance Time in Children

BACKGROUND

Mucociliary clearance is one of the most important protective functions of the airway. Previous studies, checking the influence of allergic rhinitis (AR) on mucociliary clearance time (MCT), were made on small patient groups and brought contradictive results.

OBJECTIVES

The aim of the study is to confirm whether AR in children influences MCT.

METHODS

The examined group consisted of 842 AR children. A total of 96 children with no history of allergy rhinitis served as a comparative group. All patients underwent saccharin and skin prick tests and tests for blood eosinophilia, nasal eosinophilia, vitamin D3 serum concentration, total and specific IgE serum concentration.

RESULTS

Nasal MCT was significantly longer in AR patients (mean ± SD: 10.5 ± 5.65 min) compared to controls (mean ± SD: 7.25 ± 4.3 min). Percentage of eosinophils in nasal smears in patients was significantly higher compared to controls and a weak, but significant positive correlation was observed between the percentage and MCT (r > 0.10, p < 0.008). Patients with intermittent and persistent moderate/ severe AR had significantly longer MCT and higher eosinophilia in nasal smears compared both to patients with intermittent and persistent mild RA and controls. No correlation was observed between MCT and: participant's age, total serum IgE, vitamin D3 serum concentration, absolute number or percentage of eosinophils in blood, prick test results or duration of illness.

CONCLUSIONS

AR affects the mucociliary clearance in children, and its deterioration is related to more severe rhinitis with higher intensity of local nasal inflammation, reflected in nasal smear eosinophilia.

Intranasal Treatment With 1, 25-Dihydroxyvitamin D3 Alleviates Allergic Rhinitis Symptoms in a Mouse Model

PURPOSE

Vitamin D is a potent immunomodulator. However, its role in the pathogenesis of allergic rhinitis is unclear.

METHODS

The aim of this study was to evaluate the antiallergic effect of intranasally applied vitamin D in an allergic rhinitis mouse model. BALB/c mice were intraperitoneally sensitized with ovalbumin (OVA) and alum before they were intranasally challenged with OVA. Then, they were intranasally administered 1, 25-dihydroxyvitamin D3 (0.02 μg) or solvent. Allergic symptom scores, eosinophil infiltration, cytokine mRNA levels (interleukin [IL]-4, IL-5, IL-10, IL-13 and interferon-γ) in the nasal tissue, and serum total immunoglobulin E (IgE) and OVA-specific IgE, IgG1, and IgG2a were analyzed and compared with negative and positive control groups. Cervical lymph nodes (LNs) were harvested for flow cytometry analysis and cell proliferation assay.

RESULTS

In the treatment group, allergic symptom scores, eosinophil infiltration, and mRNA levels of IL-4 and IL-13 were significantly lower in the nasal tissue than in the positive control group. The IL-5 mRNA level, serum total IgE, and OVA-specific IgE and IgG1 levels decreased in the treatment group; however, the difference was not significant. In the cervical LNs, CD86 expression had been down-regulated in CD11c⁺major histocompatibility complex II-high (MHCII^high) in the treatment group. Additionally, IL-4 secretion in the lymphocyte culture from cervical LNs significantly decreased.

CONCLUSIONS

The results confirm the antiallergic effect of intranasal 1,25-dihydroxyvitamin D3. It decreases CD 86 expression among CD11c⁺MHCII^high cells and T-helper type 2-mediated inflammation in the cervical LNs. Therefore, topically applied 1,25-dihydroxyvitamin D3 can be a future therapeutic agent for allergic rhinitis.

Serum 25-hydroxyvitamin D inversely associated with blood eosinophils in patients with persistent allergic rhinitis

Objective

The relationship between vitamin D and allergic rhinitis (AR) remains unclear. The present study investigated their association by examining serum 25-hydroxyvitamin D (25(OH)D) levels, blood eosinophils, and the expression of vitamin D receptors (VDR) on nasal mucosa in patients with AR.

Methods

A total of 32 patients with persistent AR and 25 controls were enrolled in this study. Serum 25(OH)D levels were detected by enzyme-linked immunosorbent assay, and eosinophils in the peripheral blood were examined by an automated hematology system, while VDR expression on inferior turbinate mucosa was assessed by immunohistochemistry. Furthermore, the correlation of serum 25(OH)D levels with blood eosinophils in persistent AR was analyzed.

Results

No significant difference in serum 25(OH)D levels was detected between the AR and control groups (p = 0.371). Interestingly, the serum 25(OH)D levels of the AR group were negatively correlated with blood eosinophil count and its proportion (p = 0.019 and p = 0.010, respectively) even when adjusting confounding factors including age, sex, body mass index, and the season of blood sampling. On the other hand, no significant difference in the expression levels of VDR on nasal mucosa was found between the AR group and the control group (p = 0.231).

Conclusion

These results suggest that the serum 25(OH)D might be inversely associated with blood eosinophils in patients with persistent AR. However, the relationship between vitamin D and AR still requires further clarification.