Effect of triclosan on the pathogenesis of allergic diseases among children

BACKGROUND

Few studies have assessed associations between allergic diseases and antibacterial agents in Taiwanese children.

OBJECTIVE

This study aimed to investigate the association of triclosan (TCS) exposure with allergic diseases among preschoolers, disease-specific IgE titers, and a child's sex.

METHODS

Pediatric data were obtained from the Childhood Environment and Allergic Diseases Study (CEAS; 2010) cohort, and their urine and blood samples were used to analyze TCS and IgE concentrations (age 3 group). Three years later, clinical data were obtained again from the age 3 group (age 6 group). Correlations of TCS levels at ages 3 and 6 years with IgE levels and allergic diseases were evaluated.

RESULTS

The TCS levels were higher at age 3 than at age 6 (geometric mean, 1.05 ng/ml vs 0.37 ng/ml). TCS levels were positively correlated with serum IgE levels at ages 3 and 6 years. Asthma and atopic dermatitis were significantly associated with TCS (adjusted OR 1.14, 95% confidence interval [CI] 1.01-1.29; OR 1.22, 95% CI 1.05-1.41). Sex-stratified analysis revealed that TCS levels were positively correlated with IgE levels among boys in the age 6 group and significantly associated with asthma, allergic rhinitis, and atopic dermatitis among boys.

SIGNIFICANCE

TCS exposure is associated with IgE levels and a potentially high risk of pediatric atopic disorders.

Specific IgE levels as an outcome predictor in egg-allergic children

BACKGROUND

Diagnosis of immunoglobulin E (IgE)-mediated egg allergy is often based on both a compatible clinical history and either elevated IgE levels or a positive skin prick test. However, the gold standard is the oral food challenge (OFC). Previous studies have pointed to a correlation between IgE levels and OFC outcomes.

OBJECTIVE

This study aimed to determine the relationship between IgE levels and the outcome of OFC, seeking to establish cut-off OFC values that indicate a high likelihood of positive OFC results.

METHODS

A total of 198 patients who underwent OFC (and a serological IgE antibody assay within the three preceding months) were reviewed and divided by OFC type (i.e., baked, cooked, or raw egg). IgE-specific levels were assessed against the challenge outcome as well as cut-offs proposed by other authors.

RESULTS

Receiver-operating characteristic (ROC) curve analysis yielded a potentially useful ovomucoid IgE-specific cutoff used in OFC with cooked egg and several egg white and ovalbumin IgE-specific cut-offs for OFC with raw egg. We found no significant relationship between other specific IgE concentrations and the challenge threshold level with baked eggs.

CONCLUSIONS

IgE-specific concentrations are useful as predictors of OFC outcome and should be considered when selecting patients challenge testing with boiled or raw egg. However, patients should undergo OFC with baked egg regardless of IgE levels.

IgE Levels to Ascaris and House Dust Mite Allergens Are Associated With Increased Histone Acetylation at Key Type-2 Immune Genes

Background

Epigenetic changes in response to allergen exposure are still not well understood. The aim of this study was to evaluate histone acetylation levels in peripheral blood leukocytes from humans naturally infected by intestinal parasites and perennially exposed to house dust mites (HDM).

Methods

Peripheral blood mononuclear cells (PBMCs) were isolated by gradient centrifugation from 20 infected and 21 non-infected individuals living in a rural/village in Colombia. Histone 3 acetylation (H3Ac) and histone 4 acetylation (H4Ac) levels were measured in six immune genes previously associated with helminth immunity by chromatin immunoprecipitation (ChIP)-quantitative PCR. Then we analyzed the association between histone acetylation levels with total parasite egg burden and IgE levels.

Results

We found an inverse correlation between H4Ac levels in the IL13 gene and egg worm burden that remained significant after adjustment by age [−0.20 (−0.32 to −0.09), p < 0.0001]. Moreover, we found significant associations between H4Ac levels in IL4 [0.32 (0.05–0.60), p = 0.02] and CHI3L1 [0.29 (0.08–0.51), p = 0.008] with the IgE levels to Ascaris lumbricoides. In addition, the levels of specific IgE antibodies to HDM were associated with H4Ac levels in the gene TNFSF13B encoding the B cell activating factor (BAFF) [0.51 (0.26–0.76), p < 0.001]. All values are presented as beta (95% CI).

Conclusion

Histone acetylation levels at key type-2 immune genes in humans were modified by nematode infection and HDM allergens and are associated with the intensity of the IgE response.

What Ancestry Can Tell Us About the Genetic Origins of Inter-Ethnic Differences in Asthma Expression

Differences in asthma prevalence have been described across different populations, suggesting that genetic ancestry can play an important role in this disease. In fact, several studies have demonstrated an association between African ancestry with increased asthma susceptibility and severity, higher immunoglobulin E levels, and lower lung function. In contrast, Native American ancestry has been shown to have a protective role for this disease. Genome-wide association studies have allowed the identification of population-specific genetic variants with varying allele frequency among populations. Additionally, the correlation of genetic ancestry at the chromosomal level with asthma and related traits by means of admixture mapping has revealed regions of the genome where ancestry is correlated with the disease. In this review, we discuss the evidence supporting the association of genetic ancestry with asthma susceptibility and asthma-related traits, and highlight the regions of the genome harboring ancestry-specific genetic risk factors.

Polycyclic aromatic hydrocarbons exposure, oxidative stress, and asthma in children

PURPOSE

Polycyclic aromatic hydrocarbons (PAHs) are known for their carcinogenic and teratogenic properties. However, little is known about the effect of PAH on our immune and respiratory systems. Hence, we investigated associations (1) between PAH exposure and IgE levels and asthma in children and (2) between PAH exposure and the oxidative stress marker 8OHdG potentially involved in disease pathogenesis stratifying by (3) sex-based differences.

METHODS

A total of 453 kindergarten children were recruited and provided samples. Urine biomarker of PAH exposure (1-OHP levels) was measured by UPLC-MS/MS and a marker of oxidative stress (8OHdG) was measured by ELISA. Serum IgE were assessed and information on asthma was collected. Associations between 1-OHP levels, 8OHdG, IgE and asthma were analyzed by multivariate linear and logistic regression. A mediation analysis was conducted to evaluate whether the risk of increased IgE and asthma related to PAH exposure is explained by 8OHdG changes.

RESULTS

Urine 1-OHP levels were positively related to 8OHdG levels (per ln-unit: β = 0.30kU/l, p = 0.002). Similar results were also found for 1-OHP levels with IgE levels (per ln-unit: β = 0.27 kU/l, p = 0.027). 1-OHP levels (per ln-unit) were significantly associated with asthma, with an OR (95% CI) of 1.42 (1.18-1.70). In addition, 1-OHP levels were associated with asthma. It is estimated that 35% of the effect of PAH exposure on asthma is mediated by 8OHdG levels.

CONCLUSION

Exposure to PAH may enhance oxidative stress and may induce asthma. The effect of PAH exposure on asthma may be mediated by oxidative stress.

Bisphenol A exposure may increase the risk of development of atopic disorders in children

BACKGROUND

Little is known about the effect of Bisphenol A (BPA) on atopic disorders.

OBJECTIVE

To investigated the associations (i) between postnatal BPA exposure and allergic diseases in children; (ii) between BPA and IgE levels for the possible disease pathogenesis; and (iii) gender-based differences.

METHODS

A total of 453 children from Childhood Environment and Allergic Diseases Study cohort with urine and blood samples were recruited in Taiwan. Urinary BPA glucoronide (BPAG) levels were measured by UPLC-MS/MS at ages 3 and 6 years. The associations between BPAG levels at different ages and IgE levels and the development of allergic diseases were evaluated by multivariate linear regression and logistic regression. A mediation analysis was also conducted to evaluate how much risk of allergic diseases in relation to BPA exposure is explained by IgE changes.

RESULTS

The BPAG levels at age 3 were positively associated with IgE levels at age 3 (β=64.85kU/l per ln-unit increase BPAG level; 95% CI, 14.59-115.11kU/l). Stratified by gender, BPAG levels at age 3 were positively associated with IgE levels at age 3, particularly in girls (β=139.23kU/l; 95% CI, 57.38-221.09kU/l). Similar results were also found at age 6. Urinary BPAG levels at age 3 were significantly associated with asthma at ages 3 and 6, with OR (95%CI) of 1.29(1.08-1.55) and 1.27(1.04-1.55). We estimated that 70% of the total effect of BPA exposure on asthma is mediated by IgE levels.

CONCLUSIONS

BPA exposures were associated with IgE levels and may increase the risk of development of allergic diseases in children particularly in girls.