Higher serum folate levels are associated with a lower risk of atopy and wheeze

Evaluation the Effect of Supplements Containing Vitamin D and Trace Elements in Patients with Moderate to Severe Asthma

Background

Asthma is a common and major allergic disease in the world. We aimed to investigate the impact of supplements with vitamin D, folic acid, selenium, zinc, and copper in patients with moderate to severe asthma.

Methods

In this clinical trial study 70 patients above six years old with moderate to severe asthma, were divided into two groups, randomly; one group received daily Asmavit syrup, 10 ml (Asmavit, Vitabiotics Ltd, London, UK), and the other group received daily 1000 IU vitamin D3 drops (Asmavit, Vitabiotics Ltd, London, UK) for two months along with ordinary treatment for asthma. Clinical and physical examinations, immunological and biochemical tests were carried out for each patient before and after the treatment.

Results

The mean age of patients was 39.9± 14.7 years old, and the mean disease duration was 8.8 ± 9.8 years. A significant increase in lung function, asthma control, and quality of life score tests was observed in both groups after the treatment (P< 0.05). There was no significant difference in cytokines expression levels before and after the treatment with vitamin D3 or Asmavit (P> 0.05). Serum levels of selenium and folic acid before treatment were correlated with disease severity, while post-treatment vitamin D levels significantly increased FEV1 (P> 0.05). Oxidative stress levels reduced in both groups, with greater reduction in the vitamin D group (P< 0.05).

Conclusions

Supplements, particularly vitamin D, when combined with standard asthma treatment, may effectively improve clinical symptoms and enhance the quality of life for asthmatic patients.

Exome sequencing identified novel variants in three Chinese patients with 5,10-methenyltetrahydrofolate synthetase deficiency

5,10-methenyltetrahydrofolate synthetase (MTHFS) deficiency is a folate metabolism disorder known as a rare autosomal recessive neurodevelopmental disorder (MIM: #618367). With central nervous system involvements, it is mainly characterized by developmental delay, epilepsy, microcephaly, hypertonia, and cranial nerves involvement. Here, we report three new cases with MTHFS deficiency from two non-consanguineous Chinese families. All patients showed white matter dysplasia and global developmental delay, of which only patient 1 and 2 manifested tonic-clonic seizures. Moreover, patient 2 had severe eczema and patient 3 had recurrent diarrhea. Both phenotypic features are firstly found in MTHFS deficiency. Trio whole-exome sequencing and sanger sequencing were used to identify four novel variants, p.Y169Tfs*17, p.S53F, c.117+1delG, and p.E61G in the MTHFS gene. The identification of four novel pathogenic variants and varied clinical features in three affected patients expands the genotype and phenotype spectrum of MTHFS deficiency. We also reviewed all cases of MTHFS deficiency that had previously been reported. The experience of diagnosis and treatment from these cases provides us a more comprehensive understanding of this rare disease.

The Role of Vitamins in the Pathogenesis of Asthma

Vitamins play a crucial role in the proper functioning of organisms. Disturbances of their levels, seen as deficiency or excess, enhance the development of various diseases, including those of the cardiovascular, immune, or respiratory systems. The present paper aims to summarize the role of vitamins in one of the most common diseases of the respiratory system, asthma. This narrative review describes the influence of vitamins on asthma and its main symptoms such as bronchial hyperreactivity, airway inflammation, oxidative stress, and airway remodeling, as well as the correlation between vitamin intake and levels and the risk of asthma in both pre- and postnatal life.

Association between serum folate levels and blood eosinophil counts in American adults with asthma: Results from NHANES 2011-2018

BACKGROUND

To date, many researches have investigated the correlation of folate and asthma occurrence. Nevertheless, few studies have discussed whether folate status is correlated with dis-ease severity, control or progression of asthma. So, we explored the correlation of serum folate and blood eosinophil counts in asthmatic adults to gain the role of folate in the control, progression, and treatment of asthma.

METHODS

Data were obtained from the 2011-2018 NHANES, in which serum folate, blood eosinophils, and other covariates were measured among 2332 asthmatic adults. The regression model, XGBoost algorithm model, and generalized linear model were used to explore the potential correlation. Moreover, we conducted stratified analyses to determine certain populations.

RESULTS

Among three models, the multivariate regression analysis demonstrated serum folate levels were negatively correlated with blood eosinophil counts among asthmatic adults with statistical significance. And we observed that blood eosinophil counts decreased by 0.20 (-0.34, -0.06)/uL for each additional unit of serum folate (nmol/L) after adjusting for confounders. Moreover, we used the XGBoost Algorithm model to identify the relative significance of chosen variables correlated with blood eosinophil counts and observed the linear relationship between serum folate levels and blood eosinophil counts by constructing the generalized linear model.

CONCLUSIONS

Our study indicated that serum folate levels were inversely associated with blood eosinophil counts in asthmatic adult populations of America, which indicated serum folate might be correlated with the immune status of asthmatic adults in some way. We suggested that serum folate might affect the control, development, and treatment of asthma. Finally, we hope more people will recognize the role of folate in asthma.

Association between Serum Folic Acid Levels and Asthma in the Korean Population: A Study Based on the 2016-2018 Korea National Health and Nutrition Examination Survey

BACKGROUND

Folic acid is involved in inflammatory reactions; however, the association between folic acid and allergic diseases, particularly asthma, remains unclear. Thus, this study aimed to evaluate the association between serum folic acid levels and asthma in Koreans.

METHODS

This study analyzed the serum folic acid levels of 6,615 individuals included in the 2016-2018 Korea National Health and Nutrition Examination Survey. The prevalence of asthma was determined using a questionnaire that identified cases of physician-diagnosed asthma. The relationship between serum folic acid levels and asthma was analyzed using logistic regression analysis.

RESULTS

Multiple logistic regression analysis showed that a 1 ng/mL increase in serum folic acid level significantly reduced the risk of asthma after adjusting for confounding factors including sex, age, household income, current smoking, current alcohol use, and body mass index (odds ratio [OR], 0.930; 95% confidence interval [CI], 0.876- 0.987; P=0.017). The relationship between the adjusted odds of asthma and serum folic acid levels were consistently inverse (OR, 2.266; 95% CI, 1.126-4.420; P for trend=0.038).

CONCLUSION

Serum folic acid levels are inversely associated with physician-diagnosed asthma in the Korean population.

Seeing the Forest for the Trees: Evaluating Population Data in Allergy-Immunology

A population-level study is essential for understanding treatment effects, epidemiologic phenomena, and health care best practices. Evaluating large populations and associated data requires an analytic framework, which is commonly used by statisticians, epidemiologists, and data scientists. This document will serve to provide an overview of these commonly employed methods in allergy and immunology research. We will draw upon recent examples from the allergy-immunology literature to contextualize discrete principles of relevance to population-level analysis that include statistical features of a study population, elements of statistical inference, regression analysis, and an overview of machine learning practices. Our intent is to guide the reader through a practical description of this important quantitative discipline and facilitate greater understanding about data and result display in the medical literature.

Encapsulation of folic acid (vitamin B9) into sporopollenin microcapsules: Physico-chemical characterisation, in vitro controlled release and photoprotection study

Folic acid (FA) is a crucial vitamin for all living creatures. However, it is susceptible to degradation under pH, heat, ultraviolet (UV) and day sunlight conditions, resulting in lowering its bioavailability. Therefore, a versatile protective encapsulation system for FA is highly required to overcome its inherent instability. We report the use of the robust Lycopodium clavatum sporopollenin (LCS) microcapsules, extracted from their natural micrometer-sized raw spores, for FA microencapsulation. The physico-chemical characterisation of the LCS microcapsules are comprehensively investigated before and after the microencapsulation using SEM, elemental, CLSM, FTIR, TGA/DTG and XRD analyses, revealing a successful FA encapsulation within the LCS in an amorphous form. The phenylpropanoid acids, responsible for the UV protection and the autofluorescence of the LCS, were found in the LCS as evidenced by FTIR analysis. TGA/DTG results revealed that the hemi-cellulose and cellulose are the major component of the LCS. A controlled and sustained release of FA from FA-loaded LCS were achieved where the release profile of FA-loaded LCS was found to be pH-dependent. The percentages of cumulative FA released after 10 h at 37 ± 0.5 °C were 45.5% and 76.1% in pH 1.2 and 7.4, respectively, ensuring controlled and slow release in simulated physiological conditions. The FA release kinetic studies indicated the prevalence of the Fickian diffusion mechanism in pH 1.2, while anomalous non-Fickian transport was ascribed for FA release in pH 7.4. The in vitro cytotoxicity assay revealed that the obtained formulations were biocompatible against the human skin fibroblast (HSF) cell line. The versatile LCS microcapsules exhibited intriguing photostability for FA under UV or sunlight irradiation. Concretely, the obtained FA sustained delivery and photoprotection properties of these LCS microcapsules validate their multifunctional characteristics, opening up intriguing applications in oral and topical drug delivery as well as in food industry.

Potential role of folate status on pulmonary function in pediatric asthma

OBJECTIVE

The aim of this study was to explore the relationship between plasma folate status and measures of airway disease (as reflected by spirometry) in children with asthma on a traditional Mediterranean diet. We hypothesized that folate deficiency is associated with lung function impairment in this group of children.

METHODS

This cross-sectional study included 64 children with mild asthma (52% boys, mean age 8 ± 2 y) residing in Athens, Greece. Clinical assessments included spirometry and fractional exhaled nitric oxide (FeNO). Plasma 5-methyltetrahydrofolate (5-MTHF) was analyzed using high performance-liquid chromatography assay and examined in participants using quartiles (Q1-Q4).

RESULTS

Of the 64 children, 45.3% were folate deficient (5-MTHF <10 nmol/L). A positive relationship was observed between 5-MTHF and forced vital capacity (FVC; β = 0.79, 95% confidence interval (CI), 0.14-1.44; adjusted P = 0.019), forced expiratory volume in 1s (FEV₁) (β = 0.78; 95% CI, 0.01-1.55; adjusted P = 0.046), and peak expiratory flow (PEF; β = 1.64; 95% CI, 0.14-3.15; adjusted P = 0.033) in girls only, adjusting for body mass index and regular exercise. Girls with low plasma folate concentrations (Q1), compared with girls with high concentrations (Q4) had 8.64% lower FVC (β = -8.64; 95% CI, -16.18 to -1.09; adjusted P = 0.027), 10.35% FEV₁ (β = -10.35; 95% CI, -18.82 to -1.89; adjusted P = 0.019), and 18.72% PEF (β = -18.72; 95% CI, -36.30 to -1.14; adjusted P = 0.038).

CONCLUSION

The findings of this study highlighted the potential negative effects of folate deficiency on pulmonary function in girls with asthma, the importance of monitoring folate status in children with asthma, and early prevention strategies.

High Serum Folate Concentration Is Associated with Better Lung Function in Male Chronic Obstructive Pulmonary Disease Patients Who Are Current Smokers: Analysis of Nationwide Population-Based Survey

Folate, folic acid, has a role in mitigating inflammatory reactions in the human body. This study aimed to evaluate the association of serum folate levels with lung function in chronic obstructive pulmonary disease (COPD) patients. Of the 8149 participants of the 2016 Korean National Health and Nutrition Examination Survey (KNHANES), 311 subjects (192 males and 119 females) having COPD defined by the lower fifth percentile of the reference population were selected. Pearson's correlation coefficient was used to investigate the relationship between serum folate level and lung function measurements. The association between the serum folate level and lung function in patients with COPD was evaluated using multivariable linear regression analysis after adjustment for age, sex, height, high sensitivity C-reactive protein, total calorie intake, residence, smoking status and smoking pack-years, education, and household income. The serum folate level showed a positive correlation with the predicted percentage of forced expiratory volume in one second (FEV₁%). In males, a trend for a positive correlation with serum folate level was observed in predicted FEV₁%, FEV₁ value, predicted percentage of forced vital capacity (FVC%), FVC value, and peak expiratory flow (PEF). No significant correlation between the serum folate level and lung function in females was observed. In the multivariable linear regression model, the serum folate level was associated with an increase in predicted FEV1%, FEV₁ value, predicted FVC%, FVC value, and PEF; however, the significance was only observed in males, especially among current smokers. High serum folate level was positively associated with lung function measurements in male COPD patients who were current smokers. Further longitudinal studies are needed to elucidate the underlying mechanisms.

Effects of a Novel Barley-Based Formulation on Allergic Rhinitis: A Randomized Controlled Trial

OBJECTIVE

Current treatment options for Allergic Rhinitis (AR) may have their own limitations and side effects. This study aimed to investigate the effects of Ma-al-Shaeer (MS), a novel natural formulation based on Hordeum vulgare, in the treatment of AR compared with Fexofenadine (FX).

METHODS

A total of 77 patients with AR were divided into two groups: MS group (n=38) and FX group (n=39). The first group received 15 g of dried MS powder, and the second group received 60 mg of FX twice daily for 14 days. At baseline (week zero) and after the 14-day treatment period (week two), both groups were evaluated for sneezing, rhinorrhea, nasal congestion, nasal itching, post nasal drip, eye, throat, or ear symptoms, headache, cough, mental function, quality of life scores, blood eosinophil count and total IgE levels. Rhinitis control assessment tests were conducted at week zero and again at one week after cessation of treatment (week three) in both groups.

RESULTS

All symptoms of AR except cough were significantly reduced in both groups; for nasal congestion, post nasal drip, and headache, the MS treatment was found to be superior. Rhinitis control was significantly increased after treatment in both groups (p value < 0.001). Both drugs significantly reduced total IgE levels. There was no significant change in eosinophil count in either group.

CONCLUSION

MS formulation based on H. vulgare may be an effective treatment for AR. Further studies are needed to confirm the effect of MS as an alternative treatment in AR.

Association of frequent intake of fast foods, energy drinks, or convenience food with atopic dermatitis in adolescents

PURPOSE

Specific food consumption, besides food allergy, may aggravate atopic dermatitis (AD). However, previous reports on the association between AD and food intake in adolescents are scarce. The aim of this study was to determine the relationship between AD and specific food consumption frequency in adolescents.

METHODS

A cross-sectional analysis using data from the Korea Youth Risk Behavior Web-based Survey 2017 was performed. The frequency of food consumption in the recent-diagnosed AD group (AD diagnosed within 12 months) compared to those in the previous-diagnosed AD (AD diagnosed more than 12 months ago) or control group were investigated.

RESULTS

A total of 53,373 participants were eligible for this study. The weighted prevalence of the recent-diagnosed AD and the previous-diagnosed AD was 7.39% and 18.00%, respectively. When compared with subjects with the previous-diagnosed AD, those with the recent-diagnosed AD were significantly more likely to frequently consume fast foods (odds ratio OR 1.405; 95% CI 1.150-1.717), energy drinks (OR 1.457; 95% CI 1.175-1.807), or convenience food (OR 1.304; 95% CI 1.138-1.495). Patients of the recent-diagnosed AD were significantly more likely to frequently consume fast foods (OR 1.374; 95% CI 1.155-1.634) than the control group. The differences in the frequency of specific food consumption among groups were more pronounced in high school students than in middle school students.

CONCLUSIONS

Frequent intake of fast foods, energy drinks, and convenience food was related to the recent-diagnosed AD in adolescents. Prospective cohort and interventional studies are needed to identify causal relationships.

A novel zebrafish model to emulate lung injury by folate deficiency-induced swim bladder defectiveness and protease/antiprotease expression imbalance

Lung injury is one of the pathological hallmarks of most respiratory tract diseases including asthma, acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD). It involves progressive pulmonary tissue damages which are usually irreversible and incurable. Therefore, strategies to facilitate drug development against lung injury are needed. Here, we characterized the zebrafish folate-deficiency (FD) transgenic line that lacks a fully-developed swim bladder. Whole-mount in-situ hybridization revealed comparable distribution patterns of swim bladder tissue markers between wild-type and FD larvae, suggesting a proper development of swim bladder in early embryonic stages. Unexpectedly, neutrophils infiltration was not observed in the defective swim bladder. Microarray analysis revealed a significant increase and decrease of the transcripts for cathepsin L and a cystatin B (CSTB)-like (zCSTB-like) proteins, respectively, in FD larvae. The distribution of cathepsin L and the zCSTB-like transcripts was spatio-temporally specific in developing wild-type embryos and, in appropriate measure, correlated with their potential roles in maintaining swim bladder integrity. Supplementing with 5-formyltetrahydrofolate successfully prevented the swim bladder anomaly and the imbalanced expression of cathepsin L and the zCSTB-like protein induced by folate deficiency. Injecting the purified recombinant zebrafish zCSTB-like protein alleviated FD-induced swim bladder anomaly. We concluded that the imbalanced expression of cathepsin L and the zCSTB-like protein contributed to the swim bladder malformation induced by FD and suggested the potential application of this transgenic line to model the lung injury and ECM remodeling associated with protease/protease inhibitor imbalance.

The potential role of folate metabolism in interstitial cystitis

The topic of interstitial cystitis (IC), also known as painful bladder syndrome (PBS), and folate/one carbon metabolism has previously been unaddressed in research. This narrative review highlights a potential connection for those with mast cell-related IC and histamine-mediated pain that is explored through four conceptual sections. The first section focuses on the nature of mast cell involvement and histamine-mediated pain in some interstitial cystitis patients. The second section reviews the literature on folate status in wider allergic conditions. The third section addresses the role of folate and methylation in general in histamine excretion. Finally, folate metabolism and vascular function are addressed because of the vascular abnormalities present in some IC bladders.

A novel nutritional intervention improves lung function in overweight/obese adolescents with poorly controlled asthma: the Supplemental Nutrition in Asthma Control (SNAC) pilot study

Asthma in the obese is often severe, difficult to treat, and characterized by less eosinophilic inflammation than asthma in the nonobese. Obesity-associated metabolic dysregulation may be a causal factor. We previously reported that a nutrient- and fiber-dense bar [Children's Hospital Oakland Research Institute (CHORI)-bar], which was designed to fill gaps in poor diets, improved metabolism in healthy overweight/obese (OW/OB) adults. In this pilot trial, OW/OB adolescents with poorly controlled asthma were randomized to weekly nutrition/exercise classes with or without twice-daily CHORI-bar consumption. Intent-to-treat analysis did not indicate CHORI-bar-specific effects. However, restricting the analysis to participants with acceptable compliance and a relatively low fraction of exhaled nitric oxide (FENO; <50/ ppb, a surrogate for noneosinophilic asthma; study participants: CHORI-bar, n = 16; controls, n = 15) indicated that CHORI-bar-specific, significant improvements in lung function (forced vital capacity, percent-predicted forced expiratory volume in 1 s, and percent-predicted forced expiratory flow between 25 and 75% of forced vital capacity), primarily in participants with low chronic inflammation (high-sensitivity C-reactive protein <1.5 mg/L). (We previously observed that chronic inflammation blunted CHORI-bar-induced metabolic improvements in healthy OW/OB adults.) Lung function improvement occurred without weight loss and was independent of improvements in metabolic and anthropometric end points and questionnaire-based measures of asthma control and quality of life. This study suggests that a nutritional intervention can improve lung function in OW/OB adolescents with asthma and relatively low FENO without requiring major changes in dietary habits, lifestyle, or weight loss and that this effect is blunted by chronic inflammation.-Bseikri, M., McCann, J. C., Lal, A., Fong, E., Graves, K., Goldrich, A., Block, D., Gildengoren, G. L., Mietus-Snyder, M., Shigenaga, M., Suh, J., Hardy, K., Ames, B. N. A novel nutritional intervention improves lung function in overweight/obese adolescents with poorly controlled asthma: the Supplemental Nutrition in Asthma Control (SNAC) pilot study.

Associations of genetic determinants of serum vitamin B12 and folate concentrations with hay fever and asthma: a Mendelian randomization meta-analysis

BACKGROUND/OBJECTIVES

Studies of the effect of vitamin B12 and folate on the risk of asthma and hay fever have shown inconsistent results that may be biased by reverse causation and confounding. We used a Mendelian randomization approach to examine a potential causal effect of vitamin B12 and folate on hay fever, asthma, and selected biomarkers of allergy by using 11 vitamin B12-associated single-nucleotide polymorphisms (SNPs) and 2 folate-associated SNPs as unconfounded markers.

SUBJECTS/METHODS

We included 162,736 participants from 9 population-based studies including the UK Biobank. Results were combined in instrumental variable and meta-analyses and effects expressed as odds ratios (ORs) or estimates with 95% confidence interval (CI).

RESULTS

Using genetic proxies for B12 and folate, instrumental variable analyses did not show evidence for associations between serum B12 and hay fever: OR = 1.02 (95% CI: 0.98, 1.05), asthma: OR = 0.99 (95% CI: 0.95, 1.04), allergic sensitization: OR = 1.02 (95% CI: 0.74, 1.40), or change in serum IgE: 10.0% (95% CI: -9.6%, 29.6%) per 100 pg/ml B12. Similarly, there was no evidence for association between serum folate and hay fever: OR = 0.74 (95% CI: 0.45, 1.21), asthma: OR = 0.80 (95% CI: 0.43, 1.49), or allergic sensitization: OR = 1.92 (95% CI: 0.11, 33.45), but there was a statistically significant association with change in serum IgE: 2.0% (95% CI: 0.43%, 3.58%) per 0.1 ng/ml serum folate.

CONCLUSIONS

Our results did not support the hypothesis that levels of vitamin B12 and folate are causally related to hay fever, asthma, or biomarkers of allergy, but we found evidence of a positive association between serum folate and serum total IgE.

Serum folate concentrations, asthma, atopy, and asthma control in Peruvian children

BACKGROUND

The relationship between folate status and asthma-related outcomes has not been carefully examined in low- and middle-income countries where folate deficiency is common.

METHODS

Ancillary analysis of an unmatched case-control study in which we analyzed serum folate concentrations in 412 children with asthma and 342 controls living in peri-urban communities in Lima, Peru. We examined baseline associations between folate and asthma, atopy, total serum IgE, pulmonary function, and fractional exhaled nitric oxide. We then followed children with asthma longitudinally for 6-9 months and assessed associations between folate and odds of uncontrolled asthma (defined as Asthma Control Test score ≤ 19) and of ≥1 emergency visits during follow-up.

RESULTS

A 10 ng/mL decrease in serum folate was associated with 45% higher adjusted odds of asthma (OR = 1.45, 95% CI 1.05-2.02). The folate-asthma relationship differed by atopic status: a 10 ng/mL decrease in serum folate was associated with a 2.4-fold higher odds of asthma among children without atopy (2.38, 1.20-4.72) and 23% higher odds of asthma in children with atopy (1.23, 0.85-1.80). Among children with asthma, a 10 ng/mL decrease in serum folate was associated with 62% higher odds of uncontrolled asthma (1.62, 1.02-2.56) and 73% higher odds of ≥1 emergency visits during follow-up (1.73, 1.05-2.85).

CONCLUSIONS

Serum folate concentrations were inversely associated with asthma, but this effect was stronger in children without atopy. Among children with asthma, lower serum folate concentrations were associated with higher risk of uncontrolled asthma.

Large -scale wheat flour folic acid fortification program increases plasma folate levels among women of reproductive age in urban Tanzania

There is widespread vitamin and mineral deficiency problem in Tanzania with known deficiencies of at least vitamin A, iron, folate and zinc, resulting in lasting negative consequences especially on maternal health, cognitive development and thus the nation's economic potential. Folate deficiency is associated with significant adverse health effects among women of reproductive age, including a higher risk of neural tube defects. Several countries, including Tanzania, have implemented mandatory fortification of wheat and maize flour but evidence on the effectiveness of these programs in developing countries remains limited. We evaluated the effectiveness of Tanzania's food fortification program by examining folate levels for women of reproductive age, 18-49 years. A prospective cohort study with 600 non-pregnant women enrolled concurrent with the initiation of food fortification and followed up for 1 year thereafter. Blood samples, dietary intake and fortified foods consumption data were collected at baseline, and at 6 and 12 months. Plasma folate levels were determined using a competitive assay with folate binding protein. Using univariate and multivariate linear regression, we compared the change in plasma folate levels at six and twelve months of the program from baseline. We also assessed the relative risk of folate deficiency during follow-up using log-binomial regression. The mean (±SE) pre-fortification plasma folate level for the women was 5.44-ng/ml (±2.30) at baseline. These levels improved significantly at six months [difference: 4.57ng/ml (±2.89)] and 12 months [difference: 4.27ng/ml (±4.18)]. Based on plasma folate cut-off level of 4 ng/ml, the prevalence of folate deficiency was 26.9% at baseline, and 5% at twelve months. One ng/ml increase in plasma folate from baseline was associated with a 25% decreased risk of folate deficiency at 12 months [(RR = 0.75; 95% CI = 0.67-0.85, P<0.001]. In a setting where folate deficiency is high, food fortification program with folic acid resulted in significant improvements in folate status among women of reproductive age.

Dietary intake is associated with respiratory health outcomes and DNA methylation in children with asthma

BACKGROUND

Asthma is an increasingly common chronic disease among children, and data point toward a complex mechanism involving genetic, environmental and epigenetic factors. Epigenetic modifications such as DNA hypo- or hyper-methylation have been shown to occur in response to environmental exposures including dietary nutrients.

METHODS

Within the context of the asthma randomized trial of indoor wood smoke (ARTIS) study, we investigated relationships between diet, asthma health measures, and DNA methylation. Asthma health measures included a quality of life instrument, diurnal peak flow variability (dPFV) and forced expiratory volume in the first second (FEV₁). Dietary intake was assessed with a food frequency questionnaire. Methylation levels of LINE-1 repetitive element and two promoter CpG sites for interferon gamma (IFNγ, -186 and -54) from buccal cell DNA were measured using pyrosequencing assays.

RESULTS

Data were collected on 32 children with asthma living in western Montana who were recruited to the ARTIS study. Selenium and several methyl donor dietary nutrients were positively associated with the asthma quality of life measure. Intake of methyl donating nutrients including folate was positively associated LINE-1 methylation and negatively associated with IFNγ CpG-186. Higher levels of LINE-1 methylation were associated with greater dPFV.

CONCLUSION

We identified several nutrients that were associated with improved quality of life measures among children with asthma. The IFNγ promoter CpG site -186 but not -54 was associated with the intake of selected dietary nutrients. However, in this small population of children with asthma, the IFNγ promoter CpG sites were not associated with respiratory health measures so it remains unclear through which epigenetic mechanism these nutrients are impacting the quality of life measure. These findings add to the evidence that dietary nutrients, particularly foods containing methyl donors, may be important for epigenetic regulation as it pertains to the control of asthma. Trial registration ClincialTrials.gov NCT00807183. Registered 10 December 2008.

The Genetics and Epigenetics of Atopic Dermatitis-Filaggrin and Other Polymorphisms

Atopic dermatitis (AD) is a chronic inflammatory skin disease caused by a combination of genetic and environmental factors. Genetic evidences depict a complex network comprising by epidermal barrier dysfunctions and dysregulation of innate and adaptive immunity in the pathogenesis of AD. Mutations in the human filaggrin gene (FLG) are the most significant and well-replicated genetic mutation associated with AD, and other mutations associated with epidermal barriers such as SPINK5, FLG-2, SPRR3, and CLDN1 have all been linked to AD. Gene variants may also contribute to the abnormal innate and adaptive responses found in AD, including mutations in PRRs and AMPs, TSLP and TSLPR, IL-1 family cytokines and receptors genes, vitamin D pathway genes, FCER1A, and Th2 and other cytokines genes. GWAS and Immunochip analysis have identified a total of 19 susceptibility loci for AD. Candidate genes at these susceptibility loci identified by GWAS and Immunochip analysis also suggest roles for epidermal barrier functions, innate and adaptive immunity, interleukin-1 family signaling, regulatory T cells, the vitamin D pathway, and the nerve growth factor pathway in the pathogenesis of AD. Increasing evidences show the modern lifestyle (i.e., the hygiene hypothesis, Western diet) and other environmental factors such as pollution and environmental tobacco smoke (ETS) lead to the increasing prevalence of AD with the development of industrialization. Epigenetic alterations in response to these environmental factors, including DNA methylation and microRNA related to immune system and skin barriers, have been found to contribute to the pathogenesis of AD. Genetic variants and epigenetic alteration might be the key tools for the molecular taxonomy of AD and provide the background for the personalized management.

Folate deficiency affects dendritic cell function and subsequent T helper cell differentiation

Insufficient folate status may be related to the increasing prevalence of immune- or inflammation-related chronic diseases. To investigate the effects of folate on immune regulation, we examined the impact of folate deficiency (FD) on dendritic cell (DC) maturation and function and, thus, T helper (Th) cells differentiation. First, bone marrow-derived DCs (BMDCs) were generated from BALB/c mice bone marrow cells cultured in folate-containing (F-BMDCs) or folate-deficient (FD-BMDCs) medium. FD-BMDC displayed more immature phenotype including reduced levels of major histocompatibility complex class II (MHC II), co-stimulatory molecules and characteristic of higher endocytic activity. FD-BMDC produced less IL-12p70 and proinflammatory cytokines in response to lipopolysaccharide. This aberrant DC maturation due to FD resulted in reduced BMDC-induced Th cell activity and lower IL-2, IFNγ, IL-13 and IL-10 productions. Further in vivo study confirmed significantly lower IFNγ and IL-10 productions by T cells and showed higher splenic naïve Th and lower memory T, effector T and regulatory T cell (Treg) percentages in mice fed with the FD diet for 13 weeks. To investigate the role of DCs on T cell activity, splenic DCs (spDC) from FD mice were cocultured with Th cells. The FD spDC had lower MHC II and CD80 expressions and subsequently impaired DC-induced Th differentiation, shown as decreased cytokine productions. This study demonstrated that folate deficiency impaired DC functions and, thus, Th differentiation and responses, suggesting that folate plays a crucial role in maintaining Th cells homeostasis.

Folate Deficiency, Atopy, and Severe Asthma Exacerbations in Puerto Rican Children

BACKGROUND

Little is known about folate and atopy or severe asthma exacerbations. We examined whether folate deficiency is associated with number of positive skin tests to allergens or severe asthma exacerbations in a high-risk population and further assessed whether such association is explained or modified by vitamin D status.

METHODS

Cross-sectional study of 582 children aged 6 to 14 years with (n = 304) and without (n = 278) asthma in San Juan, Puerto Rico. Folate deficiency was defined as plasma folate less than or equal to 20 ng/ml. Our outcomes were the number of positive skin tests to allergens (range, 0-15) in all children and (in children with asthma) one or more severe exacerbations in the previous year. Logistic and negative binomial regression models were used for the multivariate analysis. All multivariate models were adjusted for age, sex, household income, residential proximity to a major road, and (for atopy) case/control status; those for severe exacerbations were also adjusted for use of inhaled corticosteroids and vitamin D insufficiency (a plasma 25[OH]D < 30 ng/ml).

MEASUREMENTS AND MAIN RESULTS

In a multivariate analysis, folate deficiency was significantly associated with an increased degree of atopy and 2.2 times increased odds of at least one severe asthma exacerbation (95% confidence interval for odds ratio, 1.1-4.6). Compared with children who had normal levels of both folate and vitamin D, those with both folate deficiency and vitamin D insufficiency had nearly eightfold increased odds of one or more severe asthma exacerbation (95% confidence interval for adjusted odds ratio, 2.7-21.6).

CONCLUSIONS

Folate deficiency is associated with increased degree of atopy and severe asthma exacerbations in school-aged Puerto Ricans. Vitamin D insufficiency may further increase detrimental effects of folate deficiency on severe asthma exacerbations.

Folate status, regulatory T cells and MTHFR C677T polymorphism study in allergic children

PURPOSE

This study aimed to investigate early-life folate serum concentrations in children with food, inhalant or mixed type allergy. The influence of folate levels on the FoxP₃ expression in Treg (regulatory T) cells in the studied children, taking into account the MTHFR (5,10-methylenetetrahydrofolate reductase) genotypes was also analyzed.

MATERIAL AND METHODS

The study was performed in 83 allergic children (study group) and 49 healthy children (control group), aged 2-72 months. Medical history of each child was obtained and laboratory tests (serum folic acid concentrations and MTHFR C677T polymorphism) were carried out. The percentage of Treg cells was evaluated in almost a half of the examined subjects (48.5%).

RESULTS

Significantly higher serum folate levels in the group of children with food allergy than in those with inhalant allergy was confirmed (P=0.037). In the study group the TT homozygotes were characterized by significantly lower folate concentrations than CC homozygotes (P=0.045). A negative correlation was demonstrated between the FoxP₃ expression in CD4⁺CD25^highFoxP₃⁺ peripheral blood lymphocytes and serum folic acid concentrations. The correlation was more pronounced in the group of allergic children and it was statistically significant (r=-0.339, P<0.05).

CONCLUSIONS

The results of the study indicate a possibility of some effects of folate status on Treg cells, thus suggesting their potential role in the development and course of allergy in children.

Epigenetics: The New Frontier in the Landscape of Asthma

Over the years, on a global scale, asthma has continued to remain one of the leading causes of morbidity, irrespective of age, sex, or social bearings. This is despite the prevalence of varied therapeutic options to counter the pathogenesis of asthma. Asthma, as a disease per se, is a very complex one. Scientists all over the world have been trying to obtain a lucid understanding of the machinations behind asthma. This has led to many theories and conjectures. However, none of the scientific disciplines have been able to provide the missing links in the chain of asthma pathogenesis. This was until epigenetics stepped into the picture. Though epigenetic research in asthma is in its nascent stages, it has led to very exciting results, especially with regard to explaining the massive influence of environment on development of asthma and its varied phenotypes. However, there remains a lot of work to be done, especially with regard to understanding how the interactions between immune system, epigenome, and environment lead to asthma. But introduction of epigenetics has infused a fresh lease of life in research into asthma and the mood among the scientific community is that of cautious optimism.

Promising candidates for allergy prevention

Recent advances in understanding environmental risk factors for allergic diseases in children have led to renewed efforts aimed at prevention. Factors that modify the probability of developing allergies include prenatal exposures, mode of delivery, diet, patterns of medication use, and exposure to pets and farm animals. Recent advances in microbial detection techniques demonstrate that exposure to diverse microbial communities in early life is associated with a reduction in allergic disease. In fact, microbes and their metabolic products might be essential for normal immune development. Identification of these risk factors has provided new targets for prevention of allergic diseases, and possibilities of altering microbial exposure and colonization to reduce the incidence of allergies is a promising approach. This review examines the rationale, feasibility, and potential effect for the prevention of childhood allergic diseases and explores possible strategies for enhancing exposure to beneficial microbes.

Folic Acid Fortification and Women's Folate Levels in Selected Communities in Brazil - A First Look

BACKGROUND

Several countries have implemented mandatory folic acid fortification of wheat flour and selected grain products to increase the folate intake of reproductive-aged women. Brazil implemented a folic acid fortification program in 2004. No previous studies have examined folate differences among Brazilian women following the mandate.

OBJECTIVE

We evaluate differences in serum and red blood cell (RBC) folate concentrations between two samples of women of childbearing age from selective communities in Brazil, one tested before (N = 116) and the other after the mandate (N = 240).

METHODS

We compared the baseline folate levels of women enrolled in a prevention study shortly before the fortification mandate was implemented, to baseline levels of women from the same communities enrolled in the same study shortly after fortification began. The participants were women enrolled in a folate supplementation clinical trial, at a hospital specializing in treating craniofacial anomalies in the city of Bauru from January 29, 2004 to April 27, 2005. We only compared baseline folate levels before the women received oral cleft prevention program (OCPP) folic acid supplements.

RESULTS

Women enrolled after the fortification mandate had higher means of serum folate (20.3 versus 11.2 nmol/L; p < 0.001) and RBC folate (368.3 versus 177.6 nmol/L; p < 0.001) than women enrolled before the mandate. Differences in folate levels between the two groups remained after adjusting for several co-variables.

CONCLUSIONS

The results suggest that serum and RBC folate levels among women of childbearing age increased after implementing the folic acid fortification mandate in Brazil.

Asthma risk factors

BACKGROUND

Bronchial asthma is one of the most common chronic diseases in childhood, with a current prevalence of 6% to 9%, but a prevalence that is increasing at an alarming rate. Asthma is a complex genetic disorder with strong environmental influence. It imposes a growing burden on our society in terms of morbidity, quality of life, and healthcare costs. Despite large-scale efforts, only a few asthma genes have been confirmed, suggesting that the genetic underpinning of asthma is highly complex.

METHODS

A review of the literature was performed regarding atopic and nonatopic asthma risk factors, including environmental risk factors and genetic studies in adults and children.

RESULTS

Several environmental risk factors have been identified to increase the risk of developing asthma such as exposure to air pollution and tobaccos smoke as well as occupational risk factors. In addition atopy, stress, and obesity all can increases the risk for asthma in genetically susceptible persons.

CONCLUSION

Asthma represents a dysfunctional interaction with our genes and the environment to which they are exposed, especially in fetal and early infant life. The increasing prevalence of asthma in all age groups indicate that our living environment and immunity are in imbalance with each other reacting with airway inflammation to the environmental exposures and often non-harmful proteins, such as allergens causing the current "asthma and allergy epidemic." Because of the close relationship between asthma and chronic rhinosinusitis, it is important that otolaryngologists have a good understanding of asthma, the etiologic factors associated with disease, and its evaluation and management.

Does allergy begin in utero?

It has been recognized for centuries that allergic disease runs in families, implying a role for genetic factors in determining individual susceptibility. More recently, a range of evidence shows that many of these genetic factors, together with in utero environmental exposures, lead to the development of allergic disease through altered immune and organ development. Environmental exposures during pregnancy including diet, nutrient intake and toxin exposures can alter the epigenome and interact with inherited genetic and epigenetic risk factors to directly and indirectly influence organ development and immune programming. Understanding of these factors will be essential in identifying at-risk individuals and possible development of therapeutic interventions for the primary prevention of allergic disease. In this review, we summarize the evidence that suggests allergic disease begins in utero, together with possible mechanisms for the effect of environmental exposures during pregnancy on allergic disease risk, including epigenetics.

Is Folate Status a Risk Factor for Asthma or Other Allergic Diseases?

PURPOSE

It is controversial whether folate status is a risk factor for the development of asthma or other allergic diseases. This study was conducted to investigate whether indirect or direct exposure to folate and impaired folate metabolism, reflected as methylene-tetrahydrofolate reductase (MTHFR) C677T polymorphism, would contribute to the development of asthma and other allergic diseases.

METHODS

Electronic databases were searched to identify all studies assessing the association between folate status and asthma or other allergic diseases. Two reviewers independently assessed the eligibility of studies and extracted data. The relative risk (RR) or odds ratio (OR) with 95% confidence intervals (CI) was calculated and pooled.

RESULTS

Twenty-six studies (16 cohort, 7 case-control, and 3 cross-sectional studies) were identified. Maternal folic acid supplementation was not associated with the development of asthma, atopic dermatitis (AD), eczema, and sensitization in the offspring, whereas exposure during early pregnancy was related to wheeze occurrence in the offspring (RR=1.06, 95% CI=[1.02-1.09]). The TT genotype of MTHFR C677T polymorphism was at high risk of asthma (OR=1.41, 95% CI=[1.07-1.86]).

CONCLUSIONS

It is indicated that maternal folic acid supplementation during early pregnancy may increase the risk of wheeze in early childhood and that the TT genotype of MTHFR C677T polymorphism impairing folic acid metabolism would be at high risk of asthma development. These results might provide additional information for recommendations regarding forced folate consumption or folic acid supplements during pregnancy based on its well-established benefits for the prevention of congenital malformations. However, currently available evidence is of low quality which is needed to further elucidate.

Systematic review of adverse health outcomes associated with high serum or red blood cell folate concentrations

BACKGROUND

To examine the relationship between reported high serum or red blood cell (RBC) folate status and adverse health outcomes.

METHODS

We systematically searched PubMed/Medline and EMBASE (to May 2013), with no limits by study type, country or population, to identify studies reporting high folate concentrations in association with adverse health outcomes. Two reviewers screened studies and extracted data. Study quality was assessed.

RESULTS

We included 51 articles, representing 46 studies and 71 847 participants. Quantiles were used by 96% of studies to identify high folate concentrations. Eighty-three percent of serum folate and 50% of RBC folate studies reported a high folate cutoff that corresponded with a clinically normal concentration. Increasing values of reported high folate concentration did not demonstrate a consistent association with risk of adverse health outcomes. Overall, reported high folate concentrations appeared to be associated with a decreased risk of adverse health outcomes, though substantial methodological heterogeneity precluded complex analyses.

CONCLUSIONS

Our interpretation was complicated by methodological variability. High folate cutoffs varied and often corresponded with normal or desirable blood concentrations. In general, a negative association appeared to exist between reported high folate status and adverse health outcomes. Consistent methods and definitions are needed to examine high folate status and ultimately inform public health interventions.

Relationship between prenatal and postnatal exposures to folate and risks of allergic and respiratory diseases in early childhood

BACKGROUND

It is uncertain whether folate is risk or preventive factor for allergic and respiratory diseases.

OBJECTIVE

To determine the relationship between maternal or offspring folate status and subsequent development of allergic and respiratory diseases in early childhood.

METHODS

In total, 917 mother-child pairs from a prospective birth cohort in South Korea were studied. Data regarding the children's allergic and respiratory outcomes were obtained from standardized questionnaires completed by the mothers at postnatal months 6, 12, and 24. Serum folate levels were measured in the mothers at mid- and late-pregnancy, and in their children at 24 months of age. Atopic biomarkers were measured in the cord blood (CB) and at 24 months after birth. Biomarkers and clinical outcomes were analyzed and compared between the mother-child pairs divided into two groups according to median serum folate status at mid- and late-pregnancy.

RESULTS

Serum folate levels during mid-pregnancy were inversely associated with CB eosinophil count (adjusted odds ratio [OR] 0.72, 95% confidence interval [CI], 0.54-0.96) and positively associated with CB interleukin-10 levels (1.47, 1.11-1.94). Maternal folate level above the median value (≥9.5 ng/ml) during mid-pregnancy was associated with a decreased risk for the child of lower respiratory tract infections (LRTIs) at 6 months of age (adjusted OR 0.50, 95% CI 0.28-0.91) and atopic dermatitis (AD) at 24 months (adjusted OR 0.52, 95% CI 0.31-0.88), but not with LRTIs and AD at other ages.

CONCLUSIONS

A relatively high maternal serum folate level in mid-pregnancy was associated with a decreased risk of LRTIs and AD in early childhood.

Nutritional status and childhood wheezing in rural Bangladesh

OBJECTIVE

To investigate the association between current childhood nutritional status and current wheezing among pre-school children in rural Bangladesh.

DESIGN

Cross-sectional study.

SETTING

Matlab region, rural Bangladesh.

SUBJECTS

Children (n 912) aged 4·5 years. Anthropometric measurements of the mothers and their children were taken during a 1-year period from December 2007 to November 2008. Current wheezing was identified using the International Study of Asthma and Allergies in Childhood questionnaire. Serum total IgE was measured by human IgE quantitative ELISA. IgE specific antibody to dust mites (Dermatophagoides pteronyssinus) was measured by the CAP-FEIA system (Phadia AB, Uppsala, Sweden).

RESULTS

Wheezing at 4·5 years old was significantly associated with stunting (OR = 1·58; 95 % CI 1·13, 2·22) and underweight (OR = 1·39; 95 % CI 1·00, 1·94). The association with stunting remained significant after adjustment for sex, birth weight, birth length, gestational age at birth, mother's parity, maternal BMI, family history of asthma, socio-economic status, season of birth and intervention trial arm (OR = 1·74; 95 % CI 1·19, 2·56).

CONCLUSIONS

Stunting was a significant risk factor for wheezing among rural Bangladeshi children. Further studies will be required to confirm the relationship between nutritional status and allergic illnesses in developing countries.

Asthma, allergy, and responses to methyl donor supplements and nutrients

After a brief period of stabilization, recent data have shown that the prevalence of asthma and allergic diseases continues to increase. Atopic diseases are major public health problems resulting in significant disability and resource use globally. Although environmental factors influence the development of atopic disease, dietary changes might partially explain the high burden of atopic disease. Potential mechanisms through which diet is suspected to effect asthma and allergy susceptibility are through epigenetic changes, including DNA methylation. Dietary methyl donors are important in the one-carbon metabolic pathway that is essential for DNA methylation. Findings from both observational studies and interventional trials of dietary methyl donor supplementation on the development and treatment of asthma and allergy have produced mixed results. Although issues related to the differences in study design partially explain the heterogeneous results, 2 other issues have been largely overlooked in these studies. First, these nutrients affect one of many pathways and occur in many of the same foods. Second, it is now becoming clear that the human intestinal microbiome is involved in the metabolism and production of the B vitamins and other methyl donor nutrients. Future studies will need to account for both the interrelationships between these nutrients and the effects of the microbiome.

The association between serum vitamin D level and immunoglobulin E in Korean adolescents

OBJECTIVE

Vitamin D has immune modulatory functions, and thus its relationship with allergic disease has been evaluated in a number of studies. However, no concrete link between serum IgE level and vitamin D has been established. Thus, the purpose of study was to confirm the association of serum vitamin D level with the serum IgE (total and Dematophagoides farinae specific IgE) in Korean adolescents.

METHODS

A total of 365 subjects between 10 and 18 years of age were enrolled through the Korea National Health and Nutrition Examination Survey (KNHANES). Serum levels of vitamin D, total IgE, and Dermatophagoides farinae (Df) specific IgE were measured, and data for potential confounding variables were collected. Multivariate regression analyses were used to determine the independent effects of these variables.

RESULTS

Levels of both total and Df specific IgE were positively correlated with serum concentration of vitamin D (Spearman's rho (R)=0.126, p=0.016; R=0.152, p=0.004, respectively). These results were confirmed by multivariate linear regression analysis after adjusting for sex, age, and body mass index (coefficient (B): 10.45 95% confidence interval (CI): 0.59-20.31; B: 1.06, 95% CI: 0.31-1.80, respectively). And, the association between serum vitamin D and IgE showed the different results depending on the presence or absence of Df sensitization.

CONCLUSIONS

Serum concentration of vitamin D was positively associated with levels of both total IgE and Df-specific IgE in Korean adolescents.

Environmental exposures and asthma morbidity in children living in urban neighborhoods

A substantial disparity in asthma prevalence and morbidity among urban children compared with their nonurban counterparts has been recognized for more than two decades. Because of the nature of urban neighborhoods, pest allergens, such as cockroach and mouse, are present in high concentrations in US urban housing and have both repeatedly been linked to asthma morbidity in sensitized children. In addition, there is a growing body of evidence demonstrating that concentrations of many pollutants are higher indoors than outdoors in both US and European urban communities and that exposures to indoor pollutants such as particulate matter (PM) and nitrogen dioxide (NO2 ) are independently associated with symptoms in children with asthma. Although environmental interventions are challenging to implement, when they reduce relevant indoor allergen and pollutant exposures, they are associated with clear improvements in asthma. Other modifiable risk factors in urban childhood asthma that have emerged include dietary and nutritional factors. Overweight and obese children, for example, may be more susceptible to the pulmonary effects of pollutant exposure. Insufficiency of vitamin D and folate has also emerged as modifiable risk factors for asthma morbidity in children. The identification of these modifiable risk factors for urban childhood asthma morbidity offers a ripe opportunity for intervention.

Maternal folate exposure in pregnancy and childhood asthma and allergy: a systematic review

Adequate folate status in early pregnancy is critical to prevent congenital malformations, yet little is known about whether exposure to folate, specifically folic acid supplementation beyond the recommended dose, influences chronic health outcomes. The link between maternal folate levels and risk of childhood asthma and allergic disease has been investigated in 10 large prospective cohort studies that reported conflicting results. While the majority of studies reported no association, those supporting a positive relationship found a small increase in risk that was generally transient in nature, confined to early childhood, and associated with folic acid supplementation in late pregnancy. This systematic review presents background information on maternal folate exposure and childhood asthma, synthesizes the current epidemiologic evidence in the context of the methodological differences among studies and their potential limitations, and offers direction for future research.

Epigenetic regulation: the interface between prenatal and early-life exposure and asthma susceptibility

Asthma is a complex disease with genetic and environmental influences and emerging evidence suggests that epigenetic regulation is also a major contributor. Here, we focus on the developing paradigm that epigenetic dysregulation in asthma and allergy may start as early as in utero following several environmental exposures. We summarize the pathways important to the allergic immune response that are epigenetically regulated, the key environmental exposures associated with epigenetic changes in asthma genes, and newly identified epigenetic biomarkers that have been linked to clinical asthma. We conclude with a brief discussion about the potential to apply newly developing technologies in epigenetics to the diagnosis and treatment of asthma and allergy. The inherent plasticity of epigenetic regulation following environmental exposures offers opportunities for prevention using environmental remediation, measuring novel biomarkers for early identification of those at risk, and applying advances in pharmaco-epigenetics to tailor medical therapies that maximize efficacy of treatment. 'Precision Medicine' in asthma and allergy is arriving. As the field advances this may involve an individually tailored approach to the prevention, early detection, and treatment of disease based on the knowledge of an individual's epigenetic profile.

Ascaris lumbricoids Infection as a Risk Factor for Asthma and Atopy in Rural Bangladeshi Children

Controversy persists as to whether helminth infections cause or protect against asthma and atopy. The aim of this study was to investigate the effects of helminth infection on asthma and atopy among Bangladeshi children. A total of 912 children aged 4.5 years (mean = 54.4, range = 53.5–60.8 months) participated in a cross-sectional study nested into a randomized controlled trial in Bangladesh. Ever-asthma, ever-wheezing and current wheezing were identified using the International Study of Asthma and Allergies in Childhood questionnaire. Current helminth infection was defined by the presence of helminth eggs in stools, measured by routine microscopic examination. Repeated Ascaris infection was defined by the presence of anti-Ascaris IgE ≥ 0.70 UA/ml in serum measured by the CAP-FEIA method. Atopy was defined by specific IgE to house dust mite (anti-DP IgE) ≥ 0.70 UA/ml measured by the CAP-FEIA method and/or positive skin prick test (≥ 5 mm). Anti-Ascaris IgE was significantly associated with ever asthma (odds ratio (OR) = 1.86, 95% CI: 1.14–3.04, highest vs. lowest quartile; P for trend 0.016). Anti-Ascaris IgE was also significantly associated with positive anti-DP IgE (OR = 9.89, 95% CI: 6.52–15.00, highest vs. lowest; P for trend < 0.001) and positive skin prick test (OR = 1.69, 95% CI: 1.01–2.81, highest vs. lowest, P for trend 0.076). These findings suggest that repeated Ascaris infection is a risk factor for asthma and atopy in rural Bangladeshi children. Further analysis is required to examine the mechanism of developing asthma and atopy in relation to helminth infection.

Associations between serum folate and vitamin D levels and incident mouse sensitization in adults

BACKGROUND

Although both folic acid intake and vitamin D levels are hypothesized to be contributors to the increased incidence of allergic diseases, prospective studies of these relationships have not been done in adults.

OBJECTIVES

We sought to determine whether serum folate or vitamin D levels are associated with incident mouse sensitization among new workers at a mouse facility.

METHODS

Subjects started employment at the Jackson Laboratory between June 2004 and July 2007. Skin testing to mouse and other allergens and collection of questionnaire data were performed at baseline and every 6 months. Serum folate and vitamin D levels were assessed on baseline samples stored at -80°C. Folate was categorized into tertiles (2.5-10.5, 10.5-16.2, and 16.2-78.4 ng/mL, respectively). Vitamin D was categorized as less than 20 ng/mL, 20 to 29 ng/mL, or 30 ng/mL or greater. This was a nested case-control study in which 5 control subjects were matched to each case on baseline atopy and type of employment. Multivariate analyses controlled for age, sex, education, smoking, season, personal mouse exposure, and serum folate and vitamin D levels.

RESULTS

Thirty-five cases and 47 control subjects were included. The odds of incident mouse sensitization were higher in the intermediate and highest tertiles of serum folate compared with the lowest tertile of serum folate (odds ratio of 10.5 [95% CI, 1.8-61.5; P = .009] and odds ratio of 5.6 [95% CI, 1.8-31.3; P = .049], respectively, in the multivariate model). Serum vitamin D levels were not associated with incident mouse sensitization.

CONCLUSIONS

These findings support a role for higher serum folate levels in increased risk of incident allergic disease, even during adulthood.

Folate and asthma

Findings from experimental studies and animal models led to the hypothesis that folic acid supplementation during pregnancy confers an increased risk of asthma. This review provides a critical examination of current experimental and epidemiologic evidence of a causal association between folate status and asthma. In industrialized nations, the prevalence of asthma was rising before widespread fortification of foodstuffs with folic acid or folate supplementation before or during pregnancy, thus suggesting that changes in folate status are an unlikely explanation for "the asthma epidemic." Consistent with this ecologic observation, evidence from human studies does not support moderate or strong effects of folate status on asthma. Given known protective effects against neural tube and cardiac defects, there is no reason to alter current recommendations for folic acid supplementation during conception or pregnancy based on findings for folate and asthma. Although we believe that there are inadequate data to exclude a weak effect of maternal folate status on asthma or asthma symptoms, such effects could be examined within the context of very large (and ongoing) birth cohort studies. At this time, there is no justification for funding new studies of folate and asthma.

Progress in understanding the epigenetic basis for immune development, immune function, and the rising incidence of allergic disease

The profile of allergic disease worldwide continues to change as the number of severe IgE-mediated allergies increases. This phenomenon is thought to reflect the outcome of combined genetic/environmental/developmental/stochastic effects on immune development, but understanding this remains a challenge. Epigenetic disruption at key immune genes during development has been proposed as a potential explanation for how environmental exposures may alter immune cell development and function. This represents an emerging area of research with the potential to yield new understanding of how disease risk is modified. Here, we examine recent developments in this field that are defining new epigenetic paradigms of allergic disease.

Quantification of urinary folate catabolites using liquid chromatography-tandem mass spectrometry

Folate catabolites p-aminobenzoylglutamate (pABG) and p-acetamidobenzoylglutamate (apABG) in human urine result from break-down of endogenous folate pools and are potential biomarkers of folate status. There is growing interest in analysis of these non-invasive indicators of folate status, since widespread diseases such as cancer, arteriosclerosis and dementia may be linked to disturbed availability of folates. Determination of pABG and apABG in human urine is challenging due to their low urinary concentrations and due to interferences with other urinary compounds. To address these analytical difficulties, we developed an improved LC-MS/MS method with chemical derivatization for fast, selective and sensitive quantification of pABG and apABG in human urine. Forming butyl esters of urinary folate catabolites pABG and apABG improves ionization efficiency as well as enables selective chromatographic separation on standard C18 reversed-phase column material. In contrast to some previously proposed methods for folate catabolites, the new method allows precise differentiation of apABG from pABG. Partial degradation of apABG during derivatization is exactly accounted for using a second differentially labeled stable isotope internal standard. This method is highly sensitive and covers the full range of physiologically occurring concentrations (from 2 to 1000nmol/L), with volume requirements of only 80μL urine. Method performance has been validated according to widely accepted standard recommendations. Use of two stable isotope-labeled internal standards and qualifier ion monitoring for both analytes ensure correct identification and unbiased quantification. With run times of less than 2.5min per sample and cost-efficient sample preparation, this method allows exact quantitation of urinary folate catabolites pABG and apABG for large-scale non-invasive screening of folate status in clinical and epidemiological trials.

Folic acid supplementation in pregnancy: are there devils in the detail?

Maternal folic acid (FA) supplementation is well recognised to protect against neural tube defects. Folate is a critical cofactor in one-carbon metabolism involved in the epigenetic regulation of transcription that underpins development. Thus, it is possible that maternal FA supplementation may have additional, unforeseen persistent effects in the offspring. This is supported by the modification by maternal supplementation with one-carbon donors and FA of the epigenetic regulation of offspring phenotype in mutant mice. The present article reviews studies in human subjects and experimental animals of the effect of maternal FA intake and phenotypic outcomes in the offspring. Maternal FA intake was associated with a short-term increased incidence of allergy-related respiratory impairment in children and multigenerational respiratory impairment in rats. Higher maternal folate status during pregnancy was associated positively with insulin resistance in 6-year-olds. In rats, maternal FA supplementation modified hepatic metabolism and vascular function through altered transcription, in some cases underpinned by epigenetic changes. FA supplementation in pregnant rats increased mammary tumorigenesis, but decreased colorectal cancer in the offspring. Maternal FA supplementation decreased a range of congenital cardiac defects in children. These findings support the view that maternal FA supplementation induces persistent changes in a number of phenotypic outcomes in the offspring. However, the number of studies is limited and insufficient to indicate a need to change current recommendations for FA intake in pregnancy. Nevertheless, such effects should be investigated thoroughly in order to support firm conclusions about the risk of unanticipated long-term negative effects of maternal FA supplementation in humans.

Second-hand tobacco smoke and children

Cigarette smoke contains harmful chemicals with hazardous adverse effects on almost every organ in the body of smokers as well as of nonsmokers exposed to environmental tobacco smoke (ETS). There has been increasing interest in the effects of passive smoking on the health of children. In order to detect the magnitude of passive smoking in children, parental questionnaires, measuring nicotine and cotinine body levels, and evaluating expired carbon monoxide (CO) concentrations, have been used. Passive smoking causes respiratory illness, asthma, poor growth, neurological disorders, and coronary heart diseases. Herein, we focused on the deleterious influences of passive smoking on immunity and liver. Besides, its effects on the concentrations of various biomarker levels related to the oxidant/antioxidant status were considered. Understanding these effects may help clinicians to counsel parents on smoking cessation and smoke exposure elimination. It may also help to develop interventions to improve the health of children. This review potentially demonstrated some nutraceuticals with a promising role in the prevention of smoking-related diseases.