Additive immunosuppressive effects of 1,25-dihydroxyvitamin D3 and corticosteroids on TH1, but not TH2, responses

Pre- and Postnatal Vitamin D Status and Allergy Outcomes in Early Childhood

The dramatic increase in the prevalence of allergic disease in recent decades reflects environmental and behavioural changes that have altered patterns of early immune development. The very early onset of allergic diseases points to the specific vulnerability of the developing immune system to environmental changes and the development of primary intervention strategies is crucial to address this unparalleled burden. Vitamin D is known to have immunomodulatory functions. While allergic disease is multifactorial, associations with reduced sunlight exposure have led to the hypothesis that suboptimal vitamin D levels during critical early periods may be one possible explanation. Interventions to improve vitamin D status, especially in early life, may be the key to allergic disease prevention.

Association of Dietary Quality With Risk of Incident Systemic Lupus Erythematosus in the Nurses' Health Study and Nurses' Health Study II

OBJECTIVE

Knowledge remains scarce regarding diet and systemic lupus erythematosus (SLE) risk. Our objective was to investigate 4 dietary quality scores and SLE risk overall and by anti-double-stranded DNA (anti-dsDNA) positive versus negative subtypes.

METHODS

We studied 79,568 women in the Nurses' Health Study (1984-2014) and 93,554 in the Nurses' Health Study II (1991-2013). Using validated food frequency questionnaires, we calculated 4 dietary scores: the 2010 Alternative Healthy Eating Index (AHEI-2010), the Alternative Mediterranean Diet Score (aMed), the Dietary Approach to Stop Hypertension (DASH), and the Empirical Dietary Inflammatory Pattern (EDIP). Incident SLE was confirmed by medical record review. Time-varying Cox regression models estimated pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) of SLE risk, overall and by anti-dsDNA, for cumulative average dietary quality score tertiles and individual AHEI-2010 components.

RESULTS

We identified 194 incident SLE cases. SLE risk was similar in women with the highest (versus lowest) dietary scores (AHEI-2010 HR 0.78 [95% CI 0.54-1.14], aMed HR 0.82 [95% CI 0.56-1.18], DASH HR 1.16 [95% CI 0.81-1.66], EDIP HR 0.83 [95% CI 0.57-1.21]). No association was demonstrated for anti-dsDNA+ or anti-dsDNA- SLE risk. Women in the highest (versus lowest) AHEI-2010 tertile of nut/legume intake had a decreased SLE risk (HR 0.59 [95% CI 0.40-0.87]). No association was demonstrated for other AHEI-2010 components and SLE risk.

CONCLUSION

We observed no association between long-term adherence to the AHEI-2010, aMed, DASH, or EDIP scores with SLE risk, suggesting a large effect of dietary quality on SLE risk is unlikely. However, potential reduction in overall SLE risk with high nut/legume intake warrants further investigation.

Vitamin D and N-Acetyl Cysteine Supplementation in Treatment-Resistant Depressive Disorder Patients: A General Review

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Major Depressive Disorder (MDD) is often a lifetime disabling mental illness as individuals with MDD might not benefit from standard-therapy, including both pharmacological and psychosocial interventions. Novel therapies are, therefore, required.

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It was shown by recent preclinical and clinical studies that the dysfunction of glutamatergic neurotransmission might be involved in the pathophysiology of MDD. Furthermore, neuroimmune alterations could have a significant role in the pathogenesis of MDD.

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Vitamin D is a neurosteroid hormone essential for several metabolic processes, immune responses, and for regulating neurotrophic-neuroprotective processes, neurotransmission and synaptic plasticity. Recent studies have also shown Vitamin D deficiency in patients with severe psychiatric disorders, including MDD.

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Lately, clinical studies have shown the neuroprotective action of N-acetyl cysteine (NAC) through the modulation of inflammatory pathways and via the modulation of synaptic release of glutamate in cortico-subcortical brain regions; the cysteine-glutamate antiporter.

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This paper reviews the therapeutic use of Vitamin D and NAC and among individuals with refractory MDD to the first- line pharmacological interventions, reviewing the clinical studies published in the last decade.

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A detailed summary of the current evidence in this area aims to better inform psychiatrists and general practitioners on the potential benefits of Vitamin D and NAC supplementation for this disorder.

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Nutraceutical supplementation with Vitamin D and NAC in treatment-resistant MDD patients may be important not only for improving depressive clinical manifestations but also for their safety and tolerability profile. This is of great interest, especially considering the need for treating special populations affected by MDD, such as youngsters and elders. Finally, the nutraceutical approach represents a good choice, considering its better compliance by the patients compared to traditional psychopharmacological treatment.

The Role of Vitamin D in Respiratory Allergies Prevention. Why the Effect Is so Difficult to Disentangle?

Asthma and allergic rhinitis are the most common chronic childhood diseases with an increasing prevalence worldwide. There is an urgent need to look for methods of preventing allergic diseases from an early age. The relationship between vitamin D status and allergic diseases has been discussed in several studies recently. 25-hydroxyvitamin D (25(OH)D) is suggested to affect the development and/or severity of asthma and allergic rhinitis. Observational studies have seemed to confirm that vitamin D deficiency may contribute to an increase in allergy and asthma. Following interventional studies, however, have yielded ambiguous results. In this review, we describe recent findings regarding 25(OH)D impact on allergic diseases and provide a systematic analysis of the causes of great variability of the achieved results in different studies.

Association between multivitamin supplementation and mortality among patients with Ebola virus disease: An international multisite cohort study

INTRODUCTION

Micronutrient supplementation is recommended in Ebola Virus Disease (EVD) care; however, there is limited data on its therapeutic effects.

METHODS

This retrospective cohort study included patients with EVD admitted to five Ebola Treatment Units (ETU) in Sierra Leone and Liberia during September 2014 to December 2015. A uniform protocol was used to guide ETU care, however, due to supply limitations, only a subset of patients received multivitamins. Data on demographics, clinical characteristics, and laboratory testing was collected. The outcome of interest was facility-based mortality and the primary predictor was multivitamin supplementation initiated within 48 h of admission. The multivitamin formulations included: thiamine, riboflavin, niacin and vitamins A, C, and D₃. Propensity score models (PSM) were used to match patients based on covariates associated with multivitamin administration and mortality. Mortality between cases treated and untreated within 48 h of admission were compared using generalized estimating equations to calculate relative risk with bootstrap methods employed to assess statistical significance.

RESULTS

There were 424 patients with EVD who had sufficient treatment data for analysis, of which 261 (61.6%) had daily multivitamins initiated within 48 h of admission. The mean age of the cohort was 30.5 years and 59.4% were female. In the propensity score matched analysis, mortality was 53.5% among patients receiving multivitamins and 66.2% among patients not receiving multivitamins, resulting in a relative risk for mortality of 0.81 (p = 0.03) for patients receiving multivitamins.

CONCLUSION

Early multivitamin supplementation was associated with lower overall mortality. Further research on the impact of micronutrient supplementation in EVD is warranted.

The role of vitamin D and P2X7R in multiple sclerosis

Multiple sclerosis (MS) is characterized by neuroinflammatory infiltrates and central nervous system demyelination. In the neuroinflammatory foci of MS there is increased expression of a purinergic receptor, P2X7R. Although implicated in the neuroinflammation, the exact role of P2X7R in the context of MS is unclear and forms the basis of this review. In this review, we also introduce the immunopathologies and inflammatory processes in MS, with a focus on P2X7R and the possible immunomodulatory role of vitamin D deficiency in this setting.

Vitamin D, Inflammation and Immunity: Review of Literature and Considerations on Recent Translational and Clinical Research Developments

The most relevant and recent literature findings linking exposure to sunlight, Vitamin D (VD), inflammation and immune system in health and disease, are reviewed.

Reduced sunlight exposure determined hypo-vitaminosis D to be common among patients or even healthy subjects, especially at higher latitudes. Numerous studies support the hypothesis that VD insufficiency could contribute to the higher autoimmune diseases incidence in the same geographic areas.

In the present review, the ways in which VD was reported to influence immune system, contributing to organism homeostasis or disease development are addressed. In fact, some of the hormone activities were recognised to determine stimulation or inhibition of immune system components.

Several diseases, where an association with VD deficiency was studied, are summarised. Finally, the rationale for optimization of substitutive/additive therapy with VD analogues and the last innovations regarding these drugs are mentioned.

Characterization of monocyte subtypes regarding their phenotype and development in the context of graft-versus-host disease

Graft-versus-host disease (GvHD) is a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). In this study, monocyte subtypes were characterized regarding cytokine expression pattern and development in the context of GvHD. Using inflammatory S100 proteins for monocyte stimulation, it could be demonstrated that intermediate monocytes are the main producers of inflammatory cytokines such as IL-6 and TNFα known to be involved in the development of Th17 cells pointing towards an inflammatory phenotype of this monocyte subtype. Furthermore, novel aspects regarding monocyte subtype development were found. Our data reveal that prednisolone promotes the induction of intermediate monocytes from classical monocytes which correlates with HSP70 expression levels. However, 1α,25-Dihydroxyvitamin D3 treatment results in the abrogation of the prednisolone-mediated induction of this inflammatory monocyte subset and low HSP70 expression levels. Treatment of classical monocytes with pifithrin-μ, a specific HSP70 inhibitor, also leads to an inhibited induction of intermediate monocytes in the presence of prednisolone. These data point towards a predominant role of HSP70 in the development of intermediate monocytes. Thus, HSP70 might be a promising target for GvHD therapy, especially in combination with glucocorticoids, in order to decrease intermediate monocyte subset levels.

Asthma and Allergy "Epidemic" and the Role of Vitamin D Deficiency

The increase in asthma and allergies prevalence that has been recorded in many countries during the last decades, and the reemergence of vitamin D (VD) deficiency in many populations worldwide, renders fairly plausible the assumption of an underlying association between these two conditions and justifies the research effort invented in this issue. Indeed, there is growing body of evidence from epidemiological, laboratory, and clinical studies, suggesting that such an association does exist. The hypothesis of low levels of VD leading to compromised fetal programming and impairment of various immune functions involved in asthma and allergic disorders, stands as the most credible explanation of this presumed association. However, the evidence is not yet definite and there are some conflicting results among studies. As a consequence, no safe conclusions can be drawn yet, and more research is required in order to fully clarify the involvement of VD deficiency in the pathogenesis of asthma and allergies, and decide if VD has a role to play in the prevention and therapy of these disorders.

Evaluation of serum 25-hidroxy vitamin D and zinc levels in asthmatic patients

Introduction:

We aimed to investigate the impact of serum zinc, and vitamin D levels on the development of asthma, and its clinical characteristics.

Methods:

In our cross-sectional study; 50 patients who were diagnosed as atopic asthma and 70 healthy children consisted the control group. In both groups levels of vitamin D, and zinc were analyzed.

Results:

A statistically significant intergroup difference was not detected as for age, gender, body height (percentile), and weight (percentile) of the patients (p>0.05). Mean vitamin D levels in the asthmatic patient, and control groups were 32.61±9.48 nmol/L, and 42.55±15.42 nmol/L, respectively. Between two groups a statistically significant difference was found (p=0.001). Zinc levels were higher in the control group without any statistically significant difference between groups (p=0.25). A statistically significant negative correlation (−0.635) was found between vitamin D levels, and severity of asthma in the patient group. As the level of vitamin D increased, a decrease in severity of asthma was seen (p=0.04).

Conclusion:

Though larger series are needed to arrive at definitive conclusions, we think that vitamin D deficiency rather than zinc deficiency, might convey importance in the emergence, and exacerbation of asthma.

TH1 signatures are present in the lower airways of children with severe asthma, regardless of allergic status

BACKGROUND

The pathogenesis of severe asthma in childhood remains poorly understood.

OBJECTIVE

We sought to construct the immunologic landscape in the airways of children with severe asthma.

METHODS

Comprehensive analysis of multiple cell types and mediators was performed by using flow cytometry and a multiplex assay with bronchoalveolar lavage (BAL) specimens (n = 68) from 52 highly characterized allergic and nonallergic children (0.5-17 years) with severe treatment-refractory asthma. Multiple relationships were tested by using linear mixed-effects modeling.

RESULTS

Memory CCR5⁺ T_H1 cells were enriched in BAL fluid versus blood, and pathogenic respiratory viruses and bacteria were readily detected. IFN-γ⁺IL-17⁺ and IFN-γ^-IL-17⁺ subsets constituted secondary T_H types, and BAL fluid CD8⁺ T cells were almost exclusively IFN-γ⁺. The T_H17-associated mediators IL-23 and macrophage inflammatory protein 3α/CCL20 were highly expressed. Despite low T_H2 numbers, T_H2 cytokines were detected, and T_H2 skewing correlated with total IgE levels. Type 2 innate lymphoid cells and basophils were scarce in BAL fluid. Levels of IL-5, IL-33, and IL-28A/IFN-λ2 were increased in multisensitized children and correlated with IgE levels to dust mite, ryegrass, and fungi but not cat, ragweed, or food sources. Additionally, levels of IL-5, but no other cytokine, increased with age and correlated with eosinophil numbers in BAL fluid and blood. Both plasmacytoid and IgE⁺FcεRI⁺ myeloid dendritic cells were present in BAL fluid.

CONCLUSIONS

The lower airways of children with severe asthma display a dominant T_H1 signature and atypical cytokine profiles that link to allergic status. Our findings deviate from established paradigms and warrant further assessment of the pathogenicity of T_H1 cells in patients with severe asthma.

Increase of Intermediate Monocytes in Graft-versus-Host Disease: Correlation with MDR1+Th17.1 Levels and the Effect of Prednisolone and 1α,25-Dihydroxyvitamin D3

Graft-versus-host disease (GVHD) remains one of the major complications after allogeneic hematopoietic stem cell transplantation that is mainly treated with glucocorticoids such as prednisolone. In this study the influence of monocyte subpopulations, prednisolone, and 1α,25-dihydroxyvitamin D3 (1α,25-(OH)₂D3) on the induction of a proinflammatory subset of Th17 cells (MDR⁺Th17.1) characterized by CCR6⁺CXCR3^hiCCR4^loCCR10^-CD161⁺ and stable expression of the multidrug resistance protein type 1 (MDR1) was investigated. Our results demonstrate that intermediate monocytes are increased in patients with acute GVHD, promoting the induction of proinflammatory MDR1⁺Th17.1 cells. Furthermore, prednisolone induces the development of MDR1⁺Th17.1 cells, whereas 1α,25-(OH)₂D3 acts as an anti-inflammatory, leading to diminished percentages of proinflammatory MDR1⁺Th17.1 cells in the presence of prednisolone after stimulation with the TLR4-ligand S100A8/S100A9. Moreover, 1α,25-(OH)₂D3 decreased the expression level of the targets JAK2 and CD74, both associated with T cell activation, in monocytes. Thus, in steroid-resistant GVHD, 1α,25-(OH)₂D3 could be an important regulator in monocyte-induced development of proinflammatory MDR1⁺Th17.1 cells and might therefore be a potential therapeutic agent in combination with glucocorticoids for GVHD treatment.

Role of vitamin D in cystic fibrosis and non-cystic fibrosis bronchiectasis

Bronchiectasis is usually classified as cystic fibrosis (CF) related or CF unrelated (non-CF); the latter is not considered an orphan disease any more, even in developed countries. Irrespective of the underlying etiology, bronchiectasis is the result of interaction between host, pathogens, and environment. Vitamin D is known to be involved in a wide spectrum of significant immunomodulatory effects such as down-regulation of pro-inflammatory cytokines and chemokines. Respiratory epithelial cells constitutively express 1α-hydroxylase leading to the local transformation of the inactive 25(OH)-vitamin D to the active 1,25(OH)₂-vitamin D. The latter through its autocrine and paracrine functions up-regulates vitamin D dependent genes with important consequences in the local immunity of lungs. Despite the scarcity of direct evidence on the involvement of vitamin D deficiency states in the development of bronchiectasis in either CF or non-CF patients, it is reasonable to postulate that vitamin D may play some role in the pathogenesis of lung diseases and especially bronchiectasis. The potential contribution of vitamin D deficiency in the process of bronchiectasis is of particular clinical importance, taking into consideration the increasing prevalence of vitamin D deficiency worldwide and the significant morbidity of bronchiectasis. Given the well-established association of vitamin D deficiency with increased inflammation, and the indicative evidence for harmful consequences in lungs, it is intriguing to speculate that the administration of vitamin D supplementation could be a reasonable and cost effective supplementary therapeutic approach for children with non-CF bronchiectasis. Regarding CF patients, maybe in the future as more data become available, we have to re-evaluate our policy on the most appropriate dosage scheme for vitamin D.

Immunoregulation of Inflammatory and Inhibitory Cytokines by Vitamin D3 in Patients with Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is a group of idiopathic, chronic and relapsing inflammatory conditions of the gastrointestinal tract, caused by an aberrant and exaggerated immunological response in the gut. Supplementation of vitamin D3 in patients with IBD exerts both direct and indirect regulatory roles on the naïve T cells, thereby maintaining a balance between inflammatory and inhibitory cytokines. The direct actions of vitamin D3 on naïve T cells result in the proliferation of more regulatory T cells and inhibitory cytokines such as IL-4, IL-10 and IL-5. The binding of vitamin D to dendritic cells (DCs) through vitamin D receptors inhibits the action of IL-12 on DCs, resulting in the downregulation of Th1 and Th17. On the other hand, this interaction favours Th2 and Treg upregulation and facilitates the maintenance of immune homoeostasis between inflammatory and inhibitory cytokines which is essentially significant in the management of patients with IBD. The aim of this review was to explore the current and mounting scientific evidence on the roles of vitamin D3 in immunoregulation of inflammatory and inhibitory cytokines in patients with IBDs. An extensive literature search was conducted using keywords such as Vitamin D3*, IBD*, inflammatory cytokines*, inhibitory cytokines*, naïve-T-cells* and antigen presenting cells* through PubMed, SCOPUS and MEDLINE search engines. The results of the accumulated bodies of research that have been conducted demonstrate that vitamin D3 plays a major role not only in the immunoregulation of cytokines involved in the pathogenesis of IBDs but also in many other inflammatory disorders.

Vitamin D Induces Global Gene Transcription in Human Corneal Epithelial Cells: Implications for Corneal Inflammation

Purpose

Our previous studies show that human corneal epithelial cells (HCEC) have a functional vitamin D receptor (VDR) and respond to vitamin D by dampening TLR-induced inflammation. Here, we further examined the timing of the cytokine response to combined vitamin D–TLR treatment and used genome-wide microarray analysis to examine the effect of vitamin D on corneal gene expression.

Methods

Telomerase-immortalized HCEC (hTCEpi) were stimulated with polyinosinic-polycytidylic acid (poly[I:C]) and 1,25-dihydroxyvitamin D₃ (1,25D₃) for 2 to 24 hours and interleukin (IL)-8 expression was examined by quantitative (q)PCR and ELISA. Telomerase-immortalized HCEC and SV40-HCEC were treated with 1,25D₃ and used in genome-wide microarray analysis. Expression of target genes was validated using qPCR in both cell lines and primary HCEC. For confirmation of IκBα protein, hTCEpi were treated with 1,25D₃ for 24 hours and cell lysates used in an ELISA.

Results

Treatment with 1,25D₃ increased poly(I:C)-induced IL-8 mRNA and protein expression after 2 to 6 hours. However, when cells were pretreated with 1,25D₃ for 24 hours, 1,25D₃ decreased cytokine expression. For microarray analysis, 308 genes were differentially expressed by 1,25D₃ treatment in hTCEpi, and 69 genes in SV40s. Quantitative (q)PCR confirmed the vitamin D–mediated upregulation of target genes, including nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor, α (IκBα). In addition to increased transcript levels, IκBα protein was increased by 28% following 24 hours of vitamin D treatment.

Conclusions

Microarray analysis demonstrates that vitamin D regulates numerous genes in HCEC and influences TLR signaling through upregulation of IκBα. These findings are important in dissecting the role of vitamin D at the ocular surface and highlight the need for further research into the functions of vitamin D and its influence on corneal gene expression.

CYP3A4 is a crosslink between vitamin D and calcineurin inhibitors in solid organ transplant recipients: implications for bone health

The use of calcineurin inhibitors (CNIs) and vitamin D deficiency may contribute to the pathogenesis of post-transplant bone disease. CNIs and 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) are substrates of the drug-metabolizing enzyme CYP3A4. This review summarizes the indications for the use of activated vitamin D analogs in post-transplant care and the current knowledge on the impact of CNIs on bone. We searched for clinical evidence of the interaction between CNIs and 1,25(OH)₂D₃. We also provide an overview of the literature on the interplay between vitamin D metabolism and CYP3A4 in experimental and clinical settings and discuss its possible implications for solid organ transplant recipients. In conclusion, there is a body of evidence on the interplay between vitamin D and the drug-metabolizing enzyme CYP3A4, which may have therapeutic implications.

Effects of 1,25-dihydroxyvitamin D3 in an ovalbumin-induced allergic rhinitis model

IL-17-producing Th17 cells play an important role in allergic airway diseases, but their local expression and regulation in allergic rhinitis (AR) is not well understood. This study investigated the effects of 1,25-dihydroxyvitamin D3 (1,25-(OH)₂D₃) on T-bet expression, Th1 cells, Th2 cells, Th17 cells and IL-33-positive epithelial cells in AR. C57BL/6 mice were intranasally sensitized and challenged with ovalbumin (OVA), and 1,25-(OH)₂D₃ was intraperitoneally injected into AR mice. Cytokine levels were measured with enzyme-linked immunosorbent assays, phenotypic analysis of Th1, Th2 and Th17 cells in the spleen was completed with flow cytometry, and the CD4⁺IL-17⁺ cells in the Nasopharynx-associated lymphoid tissue (NALT) and IL-33-positive cells in nasal mucosa was evaluated with immunofluorescence microscopy. AR mice shown significantly increased Th2 and Th17 cell ratio in spleen, IL-17 level in serum, IL-5 and IL-13 levels in NALF but a lower number of IL-33-positive epithelial cells and Th1 response (Th1 and Tbet⁺Th1 cell ratio in the spleen and serum IFN-γ level) than the control mice.1,25-(OH)₂D₃ treatment significantly decreased the number of sneezing, nasal rubbing, OVA-sIgE and IL-17 in serum, IL-5 and IL-13 levels in NALF, Th17 cell ratio in the spleen and the histological of nasal mucosal but increased the number of IL-33-positive epithelial cells in AR mice. However, 1,25-(OH)₂D₃ treatment did not significantly influence IFN-γ level in serum, and Th1, Tbet⁺Th1 and Th2 cell ratio in spleen. Thus, 1,25-(OH)₂D₃ may exert anti-allergic effects by suppressing Th17 responses and local production of IL-5 and IL-13 cytokines.

Vitamin D3 derivatives, alone or in combination with glucocorticoids, suppress streptococcal pyrogenic enterotoxin A-stimulated proliferation of peripheral blood mononuclear cells in patients with psoriasis

Bacterial colonization on skin or tonsil may influence the clinical response of patients with psoriasis to immunosuppressive drugs. However, few studies have investigated the effects of bacterial superantigens on therapy in these patients. Recently, combination therapy with topical glucocorticoids (GC) and vitamin D3 (VD3) appears to be more effective than GC or VD3 monotherapy for psoriasis. We evaluated the suppressive effects of betamethasone butyrate propionate (BBP), three VD3 derivatives (calcipotriol, maxacalcitol and tacalcitol), cyclosporin and BBP plus VD3, on concanavalin A (ConA)- or streptococcal pyrogenic enterotoxin A (SPEA)-stimulated proliferation of peripheral blood mononuclear cells (PBMC) obtained from 35 psoriasis patients. Drug concentrations effecting 50% inhibition concentration of ConA- or SPEA-stimulated PBMC proliferation were estimated. Cytokine levels of tumor necrosis factor-α, γ-interferon, interleukin-1b, -2, -4, -5, -6, -8 -10 and -12p70 in PBMC culture supernatants were measured with bead-array procedures. Suppression of PBMC proliferation by BBP was significantly lower when PBMC were stimulated by SPEA than when stimulated by ConA. In contrast, the suppressive effects of calcipotriol and tacalcitol increased significantly when PBMC were stimulated by SPEA than when stimulated by ConA. The suppressive effect of BBP on SPEA-stimulated PBMC proliferation was improved significantly by adding 1-1000 ng/mL calcipotriol, compared with BBP alone. Cytokine levels in PBMC culture supernatants were not significantly different between ConA- and SPEA-stimulated PBMC. Calcipotriol and BBP in combination markedly suppressed SPEA-stimulated PBMC proliferation. SPEA produced by colonization of hemolytic streptococci may reduce the efficacy of BBP but not VD3 derivatives in the treatment of psoriasis.

The Active Metabolite of Vitamin D3 as a Potential Immunomodulator

In the past, vitamin D was known for its classical, skeletal action as a regulator of calcium and bone homoeostasis. Currently, vitamin D was found to have a role in numerous physiological processes in the human body; thus, vitamin D has pleiotropic activity. The studies carried out in the past two decades showed the role of vitamin D in the regulation of immune system functions. Basically, these effects may be mediated not only via endocrine mechanism of circulating calcitriol but also via paracrine one (based on cell-cell communication that leads to production of signal inducing the changes in nearby/adjacent cells and modulating their differentiation or behaviour) and intracrine mechanism (the action of vitamin D inside a cell) of 1,25-dihydroxycholecalciferol (1,25(OH)2 D3 ) synthetized from its precursor 25-hydroxyvitamin D3 (25(OH)D3 ). Both vitamin D receptor (VDR) and 25-hydroxyvitamin D3 1-α-hydroxylase (CYP27B1) are expressed in several types of immune cells (i.e. antigen presenting cells, T and B cells), and thus, they are able to synthetize the bioactive form of vitamin D that modulates both the innate and adaptive immune system. This review discusses the role of vitamin D as regulator of immune system, and our understanding of how vitamin D regulates both adaptive and innate immunity as well as inflammatory cascade on the cellular level.

Factors associated with 1,25-dihydroxyvitamin D3 concentrations in liver transplant recipients: a prospective observational longitudinal study

The aim of the study was to identify factors associated with 1,25(OH)2D3 concentrations in liver transplant recipients with emphasis on the renal function and catabolism. We also tested the hypothesis that tacrolimus increases 1,25(OH)2D3 concentrations. Serum 25(OH)D3, 1,25(OH)2D3, and 24,25(OH)2D3 were measured in 41 patients before, at 2 weeks and 3 months after transplantation. Dose-adjusted tacrolimus concentration was used as a surrogate marker of CYP3A4 activity. Factors associated with 1,25(OH)2D3 were identified using multivariate linear regression analysis. The median 1,25(OH)2D3 levels remained stable: 55 versus 46 pg/ml (P = 0.36) despite an increase in 25(OH)D3 from 18 ng/ml at baseline to 26 ng/ml (P = 0.03), serum albumin (34 to 41 g/l, P = 0.02), and comparable eGFR at baseline and month 3 (94 and 92 ml/min, respectively, P = 0.15). At 3 months 19 % of patients had 1,25(OH)2D3 < 25 pg/ml. Low eGFR and a low dose-adjusted tacrolimus concentration were both independently associated with 1,25(OH)2D3 at 3 months. Liver transplant recipients with impaired renal function or a low dose-adjusted tacrolimus concentration suggesting a high CYP3A4 are at risk of low 1,25(OH)2D3 concentrations. The use of tacrolimus does not lead to an increase in 1,25(OH)2D3 concentrations in a clinical setting.

Vitamin D Signaling Modulators in Cancer Therapy

The antiproliferative and pro-apoptotic effects of 1α,25-dihydroxycholecalciferol (1,25(OH)2D3, 1,25D3, calcitriol) have been demonstrated in various tumor model systems in vitro and in vivo. However, limited antitumor effects of 1,25D3 have been observed in clinical trials. This may be attributed to a variety of factors including overexpression of the primary 1,25D3 degrading enzyme, CYP24A1, in tumors, which would lead to rapid local inactivation of 1,25D3. An alternative strategy for improving the antitumor activity of 1,25D3 involves the combination with a selective CYP24A1 inhibitor. The validity of this approach is supported by numerous preclinical investigations, which demonstrate that CYP24A1 inhibitors suppress 1,25D3 catabolism in tumor cells and increase the effects of 1,25D3 on gene expression and cell growth. Studies are now required to determine whether selective CYP24A1 inhibitors+1,25D3 can be used safely and effectively in patients. CYP24A1 inhibitors plus 1,25D3 can cause dose-limiting toxicity of vitamin D (hypercalcemia) in some patients. Dexamethasone significantly reduces 1,25D3-mediated hypercalcemia and enhances the antitumor activity of 1,25D3, increases VDR-ligand binding, and increases VDR protein expression. Efforts to dissect the mechanisms responsible for CYP24A1 overexpression and combinational effect of 1,25D3/dexamethasone in tumors are underway. Understanding the cross talk between vitamin D receptor (VDR) and glucocorticoid receptor (GR) signaling axes is of crucial importance to the design of new therapies that include 1,25D3 and dexamethasone. Insights gained from these studies are expected to yield novel strategies to improve the efficacy of 1,25D3 treatment.

The Impact of Vitamin D Levels on Inflammatory Status: A Systematic Review of Immune Cell Studies

Chronic low-grade inflammation accompanies obesity and its related chronic conditions. Both peripheral blood mononuclear cells (PBMCs) and cell lines have been used to study whether vitamin D has immune modulating effects; however, to date a detailed systematic review describing the published evidence has not been completed. We therefore conducted a systematic review on the effect of vitamin D on the protein expression and secretion of inflammatory markers by human-derived immune cells. The review was registered at the International Prospective Register for Systematic Reviews (PROSPERO, Registration number CRD42015023222). A literature search was conducted using Pubmed, Science Direct, Scopus, Web of Science and Medline. The search strategy used the following search terms: Vitamin D or cholecalciferol or 1,25-dihydroxyvitamin or 25-hydroxy-Vitamin D and Inflam* or cytokine* and supplement* or cell*. These terms were searched in the abstract, title and keywords. Inclusion criteria for study selection consisted of human-derived immune cell lines or cellular studies where PBMCs were obtained from humans, reported in the English language, and within the time period of 2000 to 2015. The selection protocol was mapped according to PRISMA guidelines. Twenty three studies (7 cell line and 16 PBMCs studies) met our criteria. All studies selected except one used the active metabolite 1,25(OH)2, with one study using cholecalciferol and two studies also using 25(OH)D. Four out of seven cell line studies showed an anti-inflammatory effect where suppression of key markers such as macrophage chemotactic protein 1, interleukin 6 and interleukin 8 were observed. Fourteen of sixteen PBMC studies also showed a similar anti-inflammatory effect based on common inflammatory endpoints. Mechanisms for such effects included decreased protein expression of toll-like receptor-2 and toll-like receptor-4; lower levels of phosphorylated p38 and p42/42; reduced expression of phosphorylated signal transducer and activator of transcription 5 and decreased reactive oxygen species. This review demonstrates that an anti-inflammatory effect of vitamin D is a consistent observation in studies of cell lines and human derived PBMCs.

Role of socioeconomic position in multiple sclerosis etiology

Multiple sclerosis (MS) is a debilitating autoimmune disease with a prominent inflammatory component. There have been strides identifying genetic and environmental MS risk factors, though much of the disease risk remains unknown. Recent large observational studies suggest adverse socioeconomic position increases the risk for MS, however the mediating biological processes are not understood. We hypothesize a prominent role for stress response, both the autonomic nervous system and the hypothalamic–pituitary–adrenal axis, which become maladaptive under frequent or chronic stimulation resulting in a proinflammatory phenotype. Thus, adverse SEP and chronic stress may predispose individuals for MS.

Immune Modulation by Vitamin D and Its Relevance to Food Allergy

Apart from its classical function in bone and calcium metabolism, vitamin D is also involved in immune regulation and has been linked to various cancers, immune disorders and allergic diseases. Within the innate and adaptive immune systems, the vitamin D receptor and enzymes in monocytes, dendritic cells, epithelial cells, T lymphocytes and B lymphocytes mediate the immune modulatory actions of vitamin D. Vitamin D insufficiency/deficiency early in life has been identified as one of the risk factors for food allergy. Several studies have observed an association between increasing latitude and food allergy prevalence, plausibly linked to lower ultraviolet radiation (UVR) exposure and vitamin D synthesis in the skin. Along with mounting epidemiological evidence of a link between vitamin D status and food allergy, mice and human studies have shed light on the modulatory properties of vitamin D on the innate and adaptive immune systems. This review will summarize the literature on the metabolism and immune modulatory properties of vitamin D, with particular reference to food allergy.

Race differences in the association between multivitamin exposure and wheezing in preterm infants

OBJECTIVE

We aimed to determine whether vitamin D exposure, as estimated by use of multivitamins, is positively or negatively associated with recurrent wheezing in infants born preterm.

STUDY DESIGN

This prospective cohort study enrolled 300 infants, born at 28(0/7) to 34(6/7) weeks gestational age, and conducted follow-up at 3-, 6-, 9- and 12-month adjusted age.

RESULT

Black (55.9%) and non-black (36.6%) infants experienced recurrent wheezing. Adjusted odds ratios (ORs) for the association between multivitamin exposure at 3 months and recurrent wheezing were 2.15 (95% confidence interval (CI): 0.97, 4.75) for black and 0.43 (95% CI: 0.19, 0.96) for non-black infants with an interaction by race (P=0.003). In lag-effect models, ORs were 2.69 (95% CI: 1.41, 5.14) for black and 0.50 (95% CI: 0.27, 0.92) for non-black infants.

CONCLUSION

Differences by race were seen in association between multivitamins and wheezing; population heterogeneity should be considered when evaluating vitamin supplementation.

Vitamin D as an adjunctive therapy in asthma. Part 1: A review of potential mechanisms

Vitamin D deficiency (VDD) is highly prevalent worldwide. The classical role for vitamin D is to regulate calcium absorption form the gastrointestinal tract and influence bone health. Recently vitamin D receptors and vitamin D metabolic enzymes have been discovered in numerous sites systemically supporting diverse extra-skeletal roles of vitamin D, for example in asthmatic disease. Further, VDD and asthma share several common risk factors including high latitude, winter season, industrialization, poor diet, obesity, and dark skin pigmentation. Vitamin D has been demonstrated to possess potent immunomodulatory effects, including effects on T cells and B cells as well as increasing production of antimicrobial peptides (e.g. cathelicidin). This immunomodulation may lead to asthma specific clinical benefits in terms of decreased bacterial/viral infections, altered airway smooth muscle-remodeling and -function as well as modulation of response to standard anti-asthma therapy (e.g. glucocorticoids and immunotherapy). Thus, vitamin D and its deficiency have a number of biological effects that are potentially important in altering the course of disease pathogenesis and severity in asthma. The purpose of this first of a two-part review is to review potential mechanisms whereby altering vitamin D status may influence asthmatic disease.

Vitamin D, allergies and asthma: focus on pediatric patients

In recent years, the interest of the scientific world towards vitamin D gradually increased, and several studies have been conducted to dissect its possible role in modulating the development/course of allergic diseases. Also, Vitamin D supplementation has been assessed as a beneficial approach for treating allergies in some, but not all studies. We reviewed herein the available and relevant literature concerning the possible links between Vitamin D, its supplementation and allergic diseases. A literature search was made independently by the Authors, identifying articles for a narrative review. As per literature, Vitamin D plays a key role in calcium and phosphate metabolism, and it is essential for bone health in infants, children and adolescents. However, there is presently insufficient evidence to support vitamin D supplementation for prevention or treatment of allergic diseases in infants, children and adolescents, concerning allergic rhinitis, asthma, food allergy and atopic dermatitis.

Vitamin E and D regulation of allergic asthma immunopathogenesis

Asthma occurs as complex interactions of the environmental and genetics. Clinical studies and animal models of asthma indicate dietary factors such as vitamin E and vitamin D as protective for asthma risk. In this review, we discuss opposing regulatory functions of tocopherol isoforms of vitamin E and regulatory functions of vitamin D in asthma and how the variation in global prevalence of asthma may be explained, at least in part, by these dietary components.

Vitamin D, steroid hormones, and autoimmunity

The endogenous serum metabolite of vitamin D (calcitriol, 1,25(OH)2 D3 ) is considered a true steroid hormone (D hormone), and like glucocorticoids (GCs) and gonadal hormones, may exert several immunomodulatory activities. Serum vitamin D deficiency (25(OH) D), and therefore reduced 1,25(OH)2 D3 availability, is considered a risk factor for several chronic/inflammatory or autoimmune conditions, including infectious diseases, type 1 diabetes, multiple sclerosis, and especially autoimmune rheumatic diseases (ARD). In ARD in particular, 1,25(OH)2 D3 regulates both innate and adaptive immunity, potentiating the innate response (antimicrobial activity) but reducing adaptive immunity (antigen presentation, T and B cell activities). Regarding a possible synergism between vitamin D and GCs, several studies show that 1,25(OH)2 D3 has significant additive effects on dexamethasone-mediated inhibition of human lymphocyte and monocyte proliferation. Conversely, vitamin D deficiency seems to play a role in increasing autoantibody production by B cells, and seasonal vitamin D declines may trigger flares in ARD, as recently shown. Finally, 1,25(OH)2 D3 seems to reduce aromatase activity and limit the negative effects related to increased peripheral estrogen metabolism (cell proliferation, B cell overactivity).

Vitamin D, the immune system and asthma

The effects of vitamin D on bone metabolism and calcium homeostasis have long been recognized. Emerging evidence has implicated vitamin D as a critical regulator of immunity, playing a role in both the innate and cell-mediated immune systems. Vitamin D deficiency has been found to be associated with several immune-mediated diseases, susceptibility to infection and cancer. Recently, there has been increasing interest in the possible link between vitamin D and asthma. Further elucidation of the role of vitamin D in lung development and immune system function may hold profound implications for the prevention and treatment of asthma.

Effect of vitamin D supplementation on cathelicidin, IFN-γ, IL-4 and Th1/Th2 transcription factors in young healthy females

OBJECTIVES

We assessed the effect of cholecalciferol and calcium supplementation on mRNA expression of cathelicidin (LL-37), Th1 and Th2 cytokines and their transcription factors in the peripheral blood mononuclear cells (PBMCs) in healthy females with vitamin D deficiency (VDD).

SUBJECTS/METHODS

Subjects included 131 females with biochemical VDD randomized to receive (a) oral cholecalciferol (60,000 IU/week for 8 weeks followed by 60,000 IU/fortnight (b) calcium (elemental calcium 500 mg twice/day) (c), dual supplementation and (d) placebo for 6 months. The mRNA expression of cathelicidin, Th1 (IFN-γ) and Th2 (IL-4 and its antagonist-IL-4δ2) cytokines and their transcription factors (T-bet, STAT4, GATA-3, STAT6) were measured in the PBMC by real-time PCR before and after intervention.

RESULTS

Cholecalciferol-supplemented groups showed significant rise of mean serum 25(OH)D (30.6 ± 7.51 and 28.6 ± 8.41 ng/ml). The expression of LL-37, IFN-γ, IL-4, IL-4δ2 and transcription factors were comparable in the four groups at baseline. Despite significant increase in mean serum 25(OH)D in the cholecalciferol-supplemented groups, their mean mRNA transcripts of LL-37, IFN-γ, IL-4, transcription factors and their IFN-γ/IL-4 and T-bet/GATA-3 ratios were similar to that of calcium and placebo groups.

CONCLUSIONS

Six months of cholecalciferol/calcium supplementation in young females with VDD do not lead to significant alteration in mRNA expression of LL-37, Th1/Th2 cytokines and their transcription factors.

Effect of vitamin D on T-helper type 9 polarized human memory cells in chronic persistent asthma

BACKGROUND

Vitamin D suppresses inflammation and vitamin D deficiency is linked to the severity of asthma symptoms. T-helper type 9 (TH9) cells are important in the pathogenesis, yet the effects of vitamin D on this subset of inflammatory T-helper cells from patients with chronic asthma is unknown.

OBJECTIVE

To determine the effects of vitamin D and dexamethasone on TH9 memory cells from adults with chronic persistent asthma and on a recall response to dust mite allergen.

METHODS

T-helper memory cells were cultured with cytokines that drive TH9 polarization with vitamin D and/or dexamethasone. Peripheral blood mononuclear cells (PBMCs) from patients with radioallergosorbent test results for house dust mite were stimulated with allergen in the presence or absence of vitamin D. Intracellular cytokines, transcription factors, and identification of cell surface phenotypic markers were determined by flow cytometry.

RESULTS

Vitamin D decreased interleukin (IL)-9, IL-5, and IL-8 but increased IL-13(+) cells in TH9 cultures. Transcription factors PU.1 and interferon regulatory factor 4 were downregulated by vitamin D but not GATA3 and c-MAF. When PBMCs from patients with positive radioallergosorbent test results were stimulated with dust mite allergen, vitamin D decreased IL-9, IL-5, and IL-13 in T-helper cells (CD4(+)). TH9 cells present in a recall response were classically TH2 (CD294(+)), and polarization by transforming growth factor-β and IL-4 altered that phenotype.

CONCLUSION

Vitamin D decreased inflammatory cytokine profiles in TH9 memory cells and CD4(+) cells stimulated with dust mite allergen. Vitamin D is additive with dexamethasone in decreasing inflammatory cytokine production from T-cell subsets implicated in asthma.

The pathophysiology of the hygiene hypothesis

There has been a considerable increase in the diagnosis of allergic diseases over the last decades. Prevalence of allergies in high-income countries and urban areas appears higher than in rural environments. While environmental factors like pollution or nutrition can be important, it is more likely that in the end they have a small association with allergies. Childhood infections and exposure to certain microbial antigens on the other hand seem to present a strong negative correlation with allergies, and therefore the increase of the allergic burden in the Western world has been frequently related to a decline of childhood infections giving birth to the "Hygiene Hypothesis". We address the issue with emphasis on the associated pathophysiology tightrope walking between the skepticism of the critics, which cast doubt on it, and the pilgrims' belief of having discovered allergy's Holy Grail.

Vitamin D in allergic disease: shedding light on a complex problem

Vitamin D is unique among nutritional factors because the intake of this special vitamin represents the sum of vitamin D obtained from diet, nutritional supplements, and endogenous production after exposure to sunlight. The current recommended nutritional intake requirements reflect needs based on its established role in calcium absorption and bone health. However, recent studies have revealed that vitamin D has important functions in the immune system and might influence the course of immune-mediated disorders, including atopic dermatitis and asthma. This review discusses the scientific rationale for a role for vitamin D in immune function, gives an update on allergic disease associations with lower vitamin D serum levels, and discusses recent observations relating to vitamin D in immune function.

Could vitamin d have a potential anti-inflammatory and anti-infective role in bronchiectasis?

Bronchiectasis is a chronic infective and inflammatory respiratory disease that causes significant morbidity and mortality. Patients with non-cystic-fibrosis bronchiectasis are frequently vitamin D deficient, and vitamin D levels correlate with disease severity. Infection-specific actions of vitamin D include the enhancement of innate immunity and the moderation of inflammation caused by the adaptive immune response. Potentially, vitamin D could influence the processes that lead to bronchiectasis and the frequency and severity of acute exacerbations. Randomized trials of vitamin D supplementation have shown effects that are likely to be protective against the development of bronchiectasis. Several issues need to be clarified before the development of clinical trials to investigate the role of vitamin D in bronchiectasis. These include an optimal vitamin D supplementation dose and appropriate and sensitive outcome measures that include assessment of exacerbation frequency and severity, lung function, and health-related quality of life.

Exposure to ultraviolet-B and risk of developing rheumatoid arthritis among women in the Nurses' Health Study

OBJECTIVE

To examine the association between ultraviolet-B (UV-B) light exposure and rheumatoid arthritis (RA) risk among women in two large prospective cohort studies, the Nurses' Health Study (NHS) and the Nurses' Health Study II (NHSII).

METHODS

A total of 106 368 women from NHS, aged 30-55 years in 1976, and 115 561 women from NHSII, aged 25-42 in 1989, were included in the analysis. We identified women with incident RA from the start of each cohort until 2008 (NHS) and 2009 (NHSII). Cumulative average UV-B flux, a composite measure of ambient UV exposure based on latitude, altitude and cloud cover, was estimated according to state of residence and categorised as low, medium or high. Estimates of UV-B at birth and age 15 years were also examined. We used multivariable-adjusted Cox proportional hazards models to estimate HR and 95% CI.

RESULTS

1314 incident RA cases were identified in total. Among NHS participants, higher cumulative average UV-B exposure was associated with decreased RA risk; those in the highest versus lowest category had a 21% decreased RA risk (HR (95% CI); 0.79 (0.66 to 0.94)). UV-B was not associated with RA risk among younger women in NHSII (1.12 (0.87 to 1.44)). Results were similar for UV-B at birth and at age 15.

CONCLUSIONS

These results suggest that ambient UV-B exposure is associated with a lower RA risk in NHS, but not NHSII. Differences in sun-protective behaviours (eg, greater use of sun block in younger generations) may explain the disparate results.

Vitamin D and rheumatoid arthritis

OBJECTIVES

Vitamin D deficiency has been implicated in the pathogenesis of autoimmune diseases, such as diabetes mellitus type 1 and multiple sclerosis. Reduced vitamin D intake has been linked to increased susceptibility to the development of rheumatoid arthritis (RA) and vitamin D deficiency has been found to be associated with disease activity in patients with RA. The objective was to evaluate vitamin D status in patients with RA and to assess the relationship between vitamin D levels and disease activity.

METHODS

In a cohort of 44 patients with RA, 25-hydroxyvitamin D(3) [25(OH)D(3)] levels, parathyroid hormone levels, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured. Disease activity was evaluated by calculating the 28-joint Disease Activity Score (DAS28). A control group (n = 44), matched for age and sex, was evaluated as well.

RESULTS

In the cohort of 44 patients with RA 25(OH)D(3) levels were found to be low compared with the control group, 25(OH)D(3) being 15.26 ± 1.07 ng/ml [mean ± standard error of the mean (SEM)] and 25.8 ± 1.6 ng/ml in the patient and control group respectively (Student's t test, p < 0.001). Parathyroid hormone levels were 71.08 ± 7.02 pg/ml (mean ± SEM) (normal values 10.0-65.0 pg/ml), CRP 7.6 ± 1.57 mg/litre (mean ± SEM) (normal values < 3 mg/litre) and ESR was 38.0 ± 4.6 mm/h (mean ± SEM) in the group of patients with RA. Levels of 25(OH)D(3) were found to be negatively correlated to the DAS28, the correlation coefficient being -0.084. Levels of 25(OH)D(3) were also found to be negatively correlated to CRP and ESR, the correlation coefficient being -0.115 and -0.18, respectively.

CONCLUSION

It appears that vitamin D deficiency is highly prevalent in patients with RA, and that vitamin D deficiency may be linked to disease severity in RA. As vitamin D deficiency has been linked to diffuse musculoskeletal pain, these results have therapeutic implications. Vitamin D supplementation may be needed both for the prevention of osteoporosis as well as for pain relief in patients with RA.

Vitamin D and asthma in children

Vitamin D deficiency and insufficiency are increasingly being recognized in the general population, and have been largely attributed to lifestyle changes (reduced exposure to sunshine due to working indoors or the use of protective clothing and sunscreen; changes in diet) over the last few decades. The musculoskeletal consequences of severe vitamin D deficiency are well established, however, a number of other disorders have now been linked to vitamin D insufficiency, including asthma. There is growing appreciation of the likely importance of vitamin D as a pleiotrophic mediator that contributes to pulmonary health. Children with asthma appear to be at increased risk of vitamin D insufficiency. Epidemiologic data suggest that low serum vitamin D in children with asthma is associated with more symptoms, exacerbations, reduced lung function, increased medication usage and severe disease. In vitro studies have demonstrated that vitamin D enhances steroid responsiveness in adult asthmatics. Vitamin D may play an important role in pulmonary health by inhibiting inflammation, in part through maintaining regulatory T cells, and direct induction of innate antimicrobial mechanisms. More research is required to fully understand the role of vitamin D in the maintenance of airway homeostasis and address the diagnostic and therapeutic implications vitamin D may have in the future of asthma management. This review summarises the current understanding and uncertainties regarding the effect of vitamin D deficiency and insufficiency in children with asthma.

Maternal late-pregnancy serum 25-hydroxyvitamin D in relation to childhood wheeze and atopic outcomes

BACKGROUND

Studies exploring the relationship between prenatal vitamin D exposure and childhood asthma have yielded conflicting results. Higher vitamin D intake during pregnancy has been shown to lower the risk of childhood wheeze, yet a study of maternal late-pregnancy serum 25-hydroxyvitamin D suggested higher serum concentrations may be associated with increased childhood asthma.

OBJECTIVE

To assess the relationship between mothers' serum 25-hydroxyvitamin D status and asthma and wheeze phenotypes in their children at age 6 years. Also to explore the relationship between maternal 25-hydroxyvitamin D status and objective measures of childhood atopy and lung function.

METHODS

Serum 25-hydroxyvitamin D was measured at 34 weeks' gestation in the mothers of 860 children born at term. Wheeze was classified as either transient or persistent/late using questionnaire data collated from 6, 12, 24 and 36 months and 6 years. At 6 years spirometry was performed and atopic status was determined by skin prick testing, exhaled nitric oxide was measured in 451 children and bronchial hyperresponsiveness in 216 children.

RESULTS

There were no significant associations between maternal late-pregnancy 25-hydroxyvitamin D status and either asthma or wheeze at age 6 years. Maternal vitamin D status was not associated with transient or persistent/late wheeze; no significant association was found between persistent/late wheeze when subdivided according to atopic status. No associations were found with skin sensitisation or lung function.

CONCLUSIONS

This study provides no evidence that exposure to higher concentrations of 25-hydroxyvitamin D in maternal serum during late pregnancy increases the risk of childhood asthma, wheeze or atopy.

Diet for the prevention of asthma and allergies in early childhood: much ado about something?

In the last decades there has been an increase in allergic disease throughout the world, particularly in children. Attempts have been made to identify the causes of this "allergy epidemic" in environmental changes and changes in population hygiene, lifestyle, socioeconomic level, and eating habits that would exert epigenetic effects. Dietetic hypotheses have been mainly focussed in long-chain polyunsaturated fatty acids, vitamin D, antioxidants, Mediterranean diet, and fruits, vegetables and fish consumption. Although the data suggest a certain association between diet and the development of asthma/allergy, there is no evidence that diet has an impact upon the prevalence of such diseases after early infancy. If indeed there is such an impact, it is likely to be confined to the prenatal period and the first months of life - when it is still possible to modulate the development of the respiratory, digestive and immune systems. Thus, once the most appropriate preventive measures have been defined, these should be implemented during pregnancy and lactation. The existing scientific evidence is unable to recommend any primary preventive measure in the general population or in different population subgroups. Special or restrictive diets in pregnant or nursing women are not indicated. Exclusive breastfeeding for six months is questioned, since solid foods should begin to be introduced at around four months of age. Once the atopic process has started, no nutritional strategies have been found to be effective as secondary or tertiary preventive measures. Longitudinal studies in cohorts of pregnant women or newborn infants could help clarify these issues.

Diet, occupational exposure and early asthma incidence among bakers, pastry makers and hairdressers

BACKGROUND

The natural history of occupational asthma (OA) is influenced by many determinants. This study aims to assess the combined roles of personal characteristics, including occupational exposure and nutritional habits, on the incidence of OA during the first years at work.

METHODS

A nested case-control study was conducted within a retrospective cohort of young workers in the bakery, pastry-making and hairdressing sectors. Cases were subjects diagnosed as 'confirmed' or 'probable' OA consecutively to a medical visit (N = 31). Controls were subjects without OA (N = 196). Atopy was defined after blood specific IgE analysis, based on the PhadiatopTM test. Occupational exposure was characterized by standardized questionnaires and diet patterns by a food frequency questionnaire.

RESULTS

Among bakers and pastry-makers, only atopy is an independent risk factor of OA (OR = 10.07 95%CI [2.76 - 36.65]). Among hairdressers, several variables are associated with OA. Body mass index (unit OR = 1.24 [1.03 - 1.48]) and the score of exposure intensity (unit OR = 1.79 [1.05 - 3.05]) are independent predictors of OA, but the role of atopy is weak (OR = 4.94 [0.66 - 36.75]). Intake of vitamin A is higher among hairdressers cases (crude p = 0.002, adjusted p = 0.01 after control for body mass index and atopy); the same observation is made for vitamin D (crude p = 0.004, adjusted p = 0.01).

CONCLUSION

This study suggests that the influence of several factors on the incidence of OA, including dietary vitamins, might vary across exposure settings.

Vitamin D improves viral response in hepatitis C genotype 2-3 naïve patients

AIM: To examine whether vitamin D improved viral response and predicted treatment outcome in patients with hepatitis C virus (HCV) genotype 2-3.

METHODS: Fifty patients with chronic HCV genotype 2-3 were randomized consecutively into two groups: Treatment group [20 subjects, age 48 ± 14 years, body mass index (BMI) 30 ± 6, 65% male], who received 180 μg pegylated α-interferon-2a plus oral ribavirin 800 mg/d (Peg/RBV), together with oral vitamin D3 (Vitamidyne D drops; 2000 IU/d, 10 drops/d, normal serum level > 32 ng/mL) for 24 wk; and control group (30 subjects, age 45 ± 10 years, BMI 26 ± 3, 60% male), who received identical therapy without vitamin D. HCV RNA was assessed by reverse transcription polymerase chain reaction. Undetectable HCV RNA at 4, 12 and 24 wk after treatment was considered as rapid virological response, complete early virological response, and sustained virological response (SVR), respectively. Biomarkers of inflammation were measured.

RESULTS: The treatment group with vitamin D had higher BMI (30 ± 6 vs 26 ± 3, P < 0.02), and high viral load (> 400 000 IU/mL, 65% vs 40%, P < 0.01) than controls. Ninety-five percent of treated patients were HCV RNA negative at week 4 and 12. At 24 wk after treatment (SVR), 19/20 (95%) treated patients and 23/30 (77%) controls were HCV RNA negative (P < 0.001). Baseline serum vitamin D levels were lower at baseline (20 ± 8 ng/mL) and increased after 12 wk vitamin D treatment, to a mean level of (34 ± 11 ng/mL). Logistic regression analysis identified vitamin D supplement [odds ratio (OR) 3.0, 95% CI 2.0-4.9, P < 0.001], serum vitamin D levels (< 15 or > 15 ng/mL, OR 2.2, P < 0.01), and BMI (< 30 or > 30, OR 2.6, P < 0.01) as independent predictors of viral response. Adverse events were mild and typical of Peg/RBV.

CONCLUSION: Low vitamin D levels predicts negative treatment outcome, and adding vitamin D to conventional Peg/RBV therapy for patients with HCV genotype 2-3 significantly improves viral response.

25-hydroxyvitamin D levels and juvenile idiopathic arthritis: is there an association with disease activity?

The aims of this study were to examine the association between serum levels of 25-hydroxyvitamin D [25(OH)D] and disease activity in juvenile idiopathic arthritis (JIA), to determine the prevalence of vitamin D (VD) deficiency [25(OH)D ≤ 19 ng/ml] and insufficiency [25(OH)D 20-29 ng/ml], and to determine factors associated with lower serum levels of 25(OH)D in this population. In this cross-sectional study, disease activity was measured using JADAS-27, as well as its individual components (physician global assessment of disease activity, parent global assessment of child's well-being, count of joints with active disease, and erythrocyte sedimentation rate). Linear regression models were developed to analyze the association between serum 25(OH)D levels and JADAS-27 and to determine variables associated with serum 25(OH)D levels. A total of 154 patients (61% girls, 88% whites) were included. Mean age was 10.6. VD deficiency was detected in 13% and insufficiency in 42%. In univariate and multivariate analyses, 25(OH)D levels were not associated with JADAS-27, neither with its individual components. However, in a subset analysis including all new-onset JIA patients (n = 27), there was a nonsignificant negative correlation between serum 25(OH)D levels and JADAS-27 (r = -0.29, P = 0.14). In the univariate and multivariate analyses, age, ethnicity, BMI, and season were significantly associated with serum 25(OH)D levels, but not total VD intake. More than 1/2 of JIA patients had serum 25(OH)D levels below 29 ng/ml; however, there was no association between serum 25(OH)D levels and disease activity. Future larger, long-term studies with new-onset JIA patients are needed to further explore the association between serum 25(OH)D levels and disease activity.