Neutrophil extracellular trap production and CCL4L2 expression influence corticosteroid response in asthma.

The association between neutrophil extracellular traps (NETs) and response to inhaled corticosteroids (ICS) in asthma is unclear. To better understand this relationship, we analyzed the blood transcriptomes from children with controlled and uncontrolled asthma in the Taiwanese Consortium of Childhood Asthma Study using weighted gene coexpression network analysis and pathway enrichment methods. We identified 298 uncontrolled asthma-specific differentially expressed genes and one gene module associated with neutrophil-mediated immunity, highlighting a potential role for neutrophils in uncontrolled asthma. We also found that NET abundance was associated with nonresponse to ICS in patients. In a neutrophilic airway inflammation murine model, steroid treatment could not suppress neutrophilic inflammation and airway hyperreactivity. However, NET disruption with deoxyribonuclease I (DNase I) efficiently inhibited airway hyperreactivity and inflammation. Using neutrophil-specific transcriptomic profiles, we found that CCL4L2 was associated with ICS nonresponse in asthma, which was validated in human and murine lung tissue. CCL4L2 expression was also negatively correlated with pulmonary function change after ICS treatment. In summary, steroids fail to suppress neutrophilic airway inflammation, highlighting the potential need to use alternative therapies such as leukotriene receptor antagonists or DNase I that target the neutrophil-associated phenotype. Furthermore, these results highlight CCL4L2 as a potential therapeutic target for individuals with asthma refractory to ICS.

PD-L1 Enhanced by cis-Urocanic Acid on Langerhans Cells Inhibits Vγ4+ γδT17 Cells in Imiquimod-Induced Skin Inflammation.

Psoriasis is an IL-23/IL-17-mediated inflammatory autoimmune dermatosis, and UVB may contribute to immunosuppression and ameliorate associated symptoms. One of the pathophysiology underlying UVB therapy is the production of cis-urocanic acid (cis-UCA) by keratinocytes. However, the detailed mechanism is yet to be fully understood. In this study, we found FLG expression and serum cis-UCA levels were significantly lower in patients with psoriasis than in healthy controls. We also noted that cis-UCA application inhibited psoriasiform inflammation through the reduction of Vγ4+ γδT17 cells in murine skin and draining lymph nodes. Meanwhile, CCR6 was downregulated on γδT17 cells, which would suppress the inflammatory reaction at a distal skin site. We revealed that the 5-hydroxytryptamine receptor 2A, the known cis-UCA receptor, was highly expressed on Langerhans cells in the skin. cis-UCA also inhibited IL-23 expression and induced PD-L1 on Langerhans cells, leading to the attenuated proliferation and migration of γδT-cells. Compared to the isotype control, α-PD-L1 treatment in vivo could reverse the antipsoriatic effects of cis-UCA. PD-L1 expression on Langerhans cells was sustained through the cis-UCA-induced mitogen-activated protein kinase/extracellular signal-regulated kinase pathway. These findings uncover the cis-UCA-induced PD-L1-mediated immunosuppression on Langerhans cells, which facilitates the resolution of inflammatory dermatoses.

Separation of Gagua Rise from Great Benham Rise in the West Philippine Basin during the Middle Eocene.

The West Philippine Basin (WPB) has started opening at ~ 58 Ma and ceased spreading at ~ 33 Ma, developing a fast spreading (~ 44 mm/yr half-spreading rate) magmatic episode between 58 and 41 Ma and the second amagmatic episode between 41 and 33 Ma. The occurrence of the first stage of spreading is closely related to the Oki-Daito mantle plume and related Benham Rise (BR) and Urdaneta Plateau (UP) activity. To the east of the Luzon-Okinawa Fracture Zone (LOFZ), BR was the most active volcanism from 48 to 41 Ma. The geomagnetic ages on both sides of the LOFZ have been determined; however, their causal relationship and evolution in the WPB remain unclear. In this study, we performed integrated analyses of multichannel seismic data and swath bathymetry data for the area to the west of the LOFZ. To the west of the LOFZ, the Gagua Rise (GR), is identified by a high residual free-air gravity anomaly, volcanic seamount chains and an overlapping spreading center. The GR is located at magnetic isochrons C20/C22 (50 to 44 Ma) and shows a thick oceanic crust of at least 12.7 km. We first propose an oceanic plateau named Great Benham Rise (GBR) which includes GR, UP and BR. We infer that the GR was a portion of the GBR since ~ 49 Ma and was separated from the GBR at ~ 41 Ma by the right-lateral LOFZ motion. Later, the relict GBR magmatism only continued in the area to the east of the LOFZ. Overall, the GBR dominates the spreading history of the WPB.

CEACAM3 decreases asthma exacerbations and modulates respiratory syncytial virus latent infection in children.

BACKGROUND: Respiratory syncytial virus (RSV) is associated with childhood asthma. Nevertheless, not all children exposed to RSV develop asthma symptoms, possibly because genes modulate the effects of RSV on asthma exacerbations. OBJECTIVE: The purpose of this study was to identify genes that modulate the effect of RSV latent infection on asthma exacerbations. METHODS: We performed a meta-analysis to investigate differentially expressed genes (DEGs) of RSV infection from Gene Expression Omnibus datasets. Expression quantitative trait loci (eQTL) methods were applied to select single nucleotide polymorphisms (SNPs) that were associated with DEGs. Gene-based analysis was used to identify SNPs that were significantly associated with asthma exacerbations in the Taiwanese Consortium of Childhood Asthma Study (TCCAS), and validation was attempted in an independent cohort, the Childhood Asthma Management Program (CAMP). Gene-RSV interaction analyses were performed to investigate the association between the interaction of SNPs and RSV latent infection on asthma exacerbations. RESULTS: A total of 352 significant DEGs were found by meta-analysis of RSV-related genes. We used 38 123 SNPs related to DEGs to investigate the genetic main effects on asthma exacerbations. We found that eight RSV-related genes (GADD45A, GYPB, MS4A3, NFE2, RNASE3, EPB41L3, CEACAM6 and CEACAM3) were significantly associated with asthma exacerbations in TCCAS and also validated in CAMP. In TCCAS, rs7251960 (CEACAM3) significantly modulated the effect of RSV latent infection on asthma exacerbations (false-discovery rate <0.05). The rs7251960 variant was associated with CEACAM3 mRNA expression in lung tissue (p for trend=1.2×10-7). CEACAM3 mRNA was reduced in nasal mucosa from subjects with asthma exacerbations in two independent datasets. CONCLUSIONS: rs7251960 is an eQTL for CEACAM3, and CEACAM3 mRNA expression is reduced in subjects experiencing asthma exacerbations. CEACAM3 may be a modulator of RSV latent infection on asthma exacerbations.

Pulmonary IL-33 orchestrates innate immune cells to mediate respiratory syncytial virus-evoked airway hyperreactivity and eosinophilia.

BACKGROUND: Respiratory syncytial virus (RSV) infection is epidemiologically linked to asthma. During RSV infection, IL-33 is elevated and promotes immune cell activation, leading to the development of asthma. However, which immune cells are responsible for triggering airway hyperreactivity (AHR), inflammation and eosinophilia remained to be clarified. We aimed to elucidate the individual roles of IL-33-activated innate immune cells, including ILC2s and ST2+ myeloid cells, in RSV infection-triggered pathophysiology. METHODS: The role of IL-33/ILC2 axis in RSV-induced AHR inflammation and eosinophilia were evaluated in the IL-33-deficient and YetCre-13 Rosa-DTA mice. Myeloid-specific, IL-33-deficient or ST2-deficient mice were employed to examine the role of IL-33 and ST2 signaling in myeloid cells. RESULTS: We found that IL-33-activated ILC2s were crucial for the development of AHR and airway inflammation, during RSV infection. ILC2-derived IL-13 was sufficient for RSV-driven AHR, since reconstitution of wild-type ILC2 rescued RSV-driven AHR in IL-13-deficient mice. Meanwhile, myeloid cell-derived IL-33 was required for airway inflammation, ST2+ myeloid cells contributed to exacerbation of airway inflammation, suggesting the importance of IL-33 signaling in these cells. Local and peripheral eosinophilia is linked to both ILC2 and myeloid IL-33 signaling. CONCLUSIONS: This study highlights the importance of IL-33-activated ILC2s in mediating RSV-triggered AHR and eosinophilia. In addition, IL-33 signaling in myeloid cells is crucial for airway inflammation.

Consumption of betel quid contributes to sensorineural hearing impairment through arecoline-induced oxidative stress.

Betel quid is one of the most widely used psychoactive substances, and is consumed by approximately 10% of the world's population. In addition to its carcinogenicity, betel quid has also been reported to affect many organs, including the brain, heart, lungs, gastrointestinal tract, and reproductive organs. As betel quid contains several neurotoxic ingredients, we hypothesize that it also possesses ototoxicity and may lead to sensorineural hearing impairment (SNHI). In this study, we investigated the contribution of betel quid consumption to SNHI in a large clinical cohort, and validated the pathogenetic mechanisms in ex vivo tissue explants. We enrolled a total of 2364 volunteers, and determined their audiologic results based on Z-scores converted from their original frequency-specific hearing thresholds. Using generalized linear regression, we identified a positive correlation between betel quid consumption and the Z-scores across different frequencies. Subsequently, we explored the toxicity of arecoline, the main neuroactive component of betel quid, on tissue explants from murine cochleae. Arecoline reduced cell activity in the explant cultures and induced apoptosis in the hair cells, probably through the effects of oxidative stress. These findings have expanded the potential hazards of betel quid to common neurological disorders, and provide insights into preventive strategies against SNHI caused by neurotoxic substances.

Longitudinal analysis of bronchodilator response in asthmatics and effect modification of age-related trends by genotype.

BACKGROUND AND OBJECTIVES: Genome Wide Association Studies (GWAS) have identified genetic polymorphisms associated with bronchodilator response (BDR), but it is unknown how these associations change across life stages. We examined the impact of genetic variants on BDR from childhood to adulthood in asthmatics to uncover potential effect modification by age. METHODS: We searched the National Human Genome Research Institute (NHGRI) catalog of published GWAS to obtain a list of genetic associations with BDR, and tested them for effect modification by age in 604 subjects from the Childhood Asthma Management Program (CAMP), a clinical trial with longitudinal measures of BDR (age range 5-30 years). We performed longitudinal analyses using linear mixed models and visualized longitudinal changes in BDR using generalized additive models with repeated measures, adjusting for treatment group, sex, and main effects of age and additive genotype. RESULTS: Increasing age was associated with decreased BDR (-0.24% per year). Polymorphisms rs295137 (T allele) near SPATS2L and rs2626393 (C allele) near ASB3 demonstrated their strongest associations with BDR in early childhood through adolescence, with a large decrease in their magnitude of effect from adolescence onward. The effect estimate for % BDR associated with rs295137 genotype (Beta = 1.3; 95%CI 0.6-2.1) was diminished by age (interaction term = -0.06, P = 0.004). The effect estimate for rs2626393 (Beta = -0.92 (95%CI -1.7 to -0.2) was also modified by age (interaction term = 0.05, P = 0.0004). CONCLUSIONS: Polymorphisms associated with BDR in childhood may not be relevant for predicting adolescent and adult BDR, which could reflect age-related changes in asthma phenotypes.

A simple prediction tool for inhaled corticosteroid response in asthmatic children.

BACKGROUND: Inhaled corticosteroids are recommended as the first-line controller medication for childhood asthma owing to their multiple clinical benefits. However, heterogeneity in the response towards these drugs remains a significant clinical problem. METHODS: Children aged 5 to 18 years with mild to moderate persistent asthma were recruited into the Taiwanese Consortium of Childhood Asthma Study. Their responses to inhaled corticosteroids were assessed based on their improvements in the asthma control test and peak expiratory flow. The predictors of responsiveness were demographic and clinical features that were available in primary care settings. We have developed a prediction model using logistic regression and have simplified it to formulate a practical tool. We assessed its predictive performance using the area under the receiver operating characteristic curve. RESULTS: Of the 73 asthmatic children with baseline and follow-up outcome measurements for inhaled corticosteroids treatment, 24 (33%) were defined as non-responders. The tool we have developed consisted of three predictors yielding a total score between 0 and 5, which are comprised of the following parameters: the age at physician-diagnosis of asthma, sex, and exhaled nitric oxide. Sensitivity and specificity of the tool for prediction of inhaled corticosteroids non-responsiveness, for a score of 3, were 0.75 and 0.69, respectively. The areas under the receiver operating characteristic curve for the prediction tool was 0.763. CONCLUSIONS: Our prediction tool represents a simple and low-cost method for predicting the response of inhaled corticosteroids treatment in asthmatic children.

Newborn genetic screening for hearing impairment: a population-based longitudinal study.

PURPOSE: The feasibility of genetic screening for deafness-causing mutations in newborns has been reported in several studies. The aim of this study was to investigate the long-term results in those who screened positive for deafness mutations; these results are crucial to determine the cost-effectiveness to justify population-wide genetic screening. METHODS: We performed simultaneous hearing screening and genetic screening targeting four common deafness mutations (p.V37I and c.235delC of GJB2, c.919-2A>G of SLC26A4, and the mitochondrial m.1555A>G) in 5173 newborns at a tertiary hospital between 2009 and 2015. Serial audiometric results up to 6 years old were then analyzed in children with conclusive genotypes. RESULTS: Newborn genetic screening identified 82 (1.6%) babies with conclusive genotypes, comprising 62 (1.2%) with GJB2 p.V37I/p.V37I, 16 (0.3%) with GJB2 p.V37I/c.235delC, and 4 (0.1%) with m.1555A>G. Of these, 46 (56.1%) passed hearing screening at birth. Long-term follow-up demonstrated progressive hearing loss in children with the GJB2 p.V37I/p.V37I and p.V37I/c.235delC genotypes; this hearing loss deteriorated by approximately 1 decibel hearing level (dBHL) per year. CONCLUSIONS: We delineated the longitudinal auditory features of the highly prevalent GJB2 p.V37I mutation on a general population basis and confirmed the utility of newborn genetic screening in identifying infants with late-onset or progressive hearing impairment undetectable by newborn hearing screening.Genet Med 19 1, 6-12.

Smoking-related microRNAs and mRNAs in human peripheral blood mononuclear cells.

Teenager smoking is of great importance in public health. Functional roles of microRNAs have been documented in smoke-induced gene expression changes, but comprehensive mechanisms of microRNA-mRNA regulation and benefits remained poorly understood. We conducted the Teenager Smoking Reduction Trial (TSRT) to investigate the causal association between active smoking reduction and whole-genome microRNA and mRNA expression changes in human peripheral blood mononuclear cells (PBMC). A total of 12 teenagers with a substantial reduction in smoke quantity and a decrease in urine cotinine/creatinine ratio were enrolled in genomic analyses. In Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA), differentially expressed genes altered by smoke reduction were mainly associated with glucocorticoid receptor signaling pathway. The integrative analysis of microRNA and mRNA found eleven differentially expressed microRNAs negatively correlated with predicted target genes. CD83 molecule regulated by miR-4498 in human PBMC, was critical for the canonical pathway of communication between innate and adaptive immune cells. Our data demonstrated that microRNAs could regulate immune responses in human PBMC after habitual smokers quit smoking and support the potential translational value of microRNAs in regulating disease-relevant gene expression caused by tobacco smoke.

Associations of serum perfluoroalkyl acid levels with T-helper cell-specific cytokines in children: By gender and asthma status.

Perfluoroalkyl acids (PFAAs) are a group of common chemicals that ubiquitously exist in wildlife and humans. Experimental data suggest that they may alter T-lymphocyte functioning in situ by preferentially enhancing the development of T-helper 2 (TH2)- and inhibiting TH1-lymphocyte development and might increase allergic inflammation, but few human studies have been conducted. To evaluate the association between serum PFAAs concentrations and T-lymphocyte-related immunological markers of asthma in children, and further to assess whether gender modified this association, 231 asthmatic children and 225 non-asthmatic control children from Northern Taiwan were recruited into the Genetic and Biomarker study for Childhood Asthma. Serum concentrations of ten PFAAs and levels of TH1 [interferon (IFN)-γ, interleukin (IL)-2] and TH2 (IL-4 and IL-5) cytokines were measured. The results showed that asthmatics had significantly higher serum PFAAs concentrations compared with the healthy controls. When stratified by gender, a greater number of significant associations between PFAAs and asthma outcomes were found in males than in females. Among males, adjusted odds ratios for asthma among those with the highest versus lowest quartile of PFAAs exposure ranged from 2.59 (95% CI: 1.14, 5.87) for the perfluorobutanesulfonate (PFBS) to 4.38 (95% CI: 2.02, 9.50) for perfluorooctanesulfonate (PFOS); and serum PFAAs were associated positively with TH2 cytokines and inversely with TH1 cytokines among male asthmatics. Among females, no significant associations between PFAAs and TH2 cytokines could be detected. In conclusion, increased serum PFAAs levels may promote TH cell dysregulation and alter the availability of key TH1 and TH2 cytokines, ultimately contributing to the development of asthma that may differentially impact males to a greater degree than females. These results have potential relevance in asthma prevention.

Gender-Dimorphic Impact of PXR Genotype and Haplotype on Hepatotoxicity During Antituberculosis Treatment.

Women have a higher risk of drug-induced hepatotoxicity during antituberculosis treatment (HATT) than men. We hypothesized that single nucleotide polymorphism (SNP) genotype and derived haplotype of pregnane X receptor (PXR) gene, which could regulate the expression of phase I enzyme cytochrome P450 (CYP) 3A4, had a sex-specific influence on the risk of HATT. Six SNPs of the PXR gene were sequenced. Genotypes and haplotypes of the PXR SNPs, and other potential risk factors for HATT were compared between pulmonary TB patients with and those without HATT. HATT was defined as an increase in serum transaminase level >3 times the upper limit of normal (ULN) with symptoms, or >5 times ULN without symptoms. We performed the study in a derivation and a validation cohort. Among the 355 patients with pulmonary TB in the derivation cohort, 70 (19.7%) developed HATT. Logistic regression analysis revealed the risk of HATT increased in female genotype AA at rs2461823 (OR: 6.87 [2.55-18.52]) and decreased in female genotype AA at rs7643645 (OR: 0.14 [0.02-1.02]) of PXR gene. Haplotype analysis showed that female h001101 (OR: 2.30 [1.22-4.32]) and female h000110 (OR: 2.25 [1.08-4.69]) haplotype were associated with increased HATT risk. The identified predictors were also significantly associated with female HATT risk among the 182 patients in the validation cohort. Two PXR SNP genotypes and 2 haplotypes influenced the risk of HATT only in females. The PXR SNP showed a sex-specific impact that contributed to an increased HATT risk in females.

Contribution of adiponectin and its type 1 receptor to age-related hearing impairment.

Age-related hearing impairment (ARHI) is a complex neurodegenerative disorder caused by a combination of environmental and genetic factors. We have reported previously that obesity increases the risk for ARHI, and that plasma levels of adiponectin are associated with ARHI. In the present study, we further explored the role of adiponectin in the pathophysiology of ARHI by investigating the genotypes of ADIPOQ and ADIPOR1, the genes of adiponectin and its type 1 receptor, respectively. A total of 1682 volunteers were enrolled, and their audiological phenotypes were determined according to the z scores converted from their original frequency-specific hearing thresholds. A total of 9 tag-single nucleotide polymorphisms (tagSNPs) in ADIPOQ and 4 tagSNPs in ADIPOR1 were genotyped, and the genotypes were correlated to the audiological phenotypes under the assumption of various inheritance models. Significant associations were identified between certain ADIPOQ tagSNPs and z scores under dominant, codominant, or additive models, whereas no association was identified between ADIPOR1 tagSNPs and z scores. The associations between ADIPOQ tagSNPs and z scores appear to exist only in subjects with specific ADIPOR1 genotypes, indicating an interaction between adiponectin and AdipoR1. Measurement of plasma adiponectin in 736 subjects revealed that ADIPOQ genotypes might exert their effects on hearing levels via modulation of plasma adiponectin levels. Subsequently, we confirmed the expression of AdipoR1 in the inner ear of mice, and demonstrated antiapoptotic effects of adiponectin in cochlear explant cultures. These results provide insights into the physiological function and potential clinical implications of adiponectin against ARHI.

Association of time-location patterns with urinary cotinine among asthmatic children under household environmental tobacco smoke exposure.

INTRODUCTION: Environmental tobacco smoke (ETS) is a hazardous component of indoor air, and may increase the risk of respiratory diseases, atherosclerosis and otitis media in children. In this study, we explored the relationship between time inside the house, ETS exposure and urinary cotinine level, and also determined the association of time inside the house on asthma phenotypes when children exposed to ETS. METHODS: A total of 222 asthmatic children and 205 non-asthmatic controls were recruited in the Genetic and Biomarker study for Childhood Asthma (GBCA). Structured questionnaires and time-location pattern questionnaires were administered by face-to-face interview. Urinary cotinine was measured by liquid chromatography tandem mass spectrometry (LC/MS/MS). The level of household ETS exposure was assessed using the cotinine/creatinine ratio (CCR). RESULTS: In general, urinary cotinine and CCR were higher in subjects exposed to household ETS than those who never had ETS at home. A significant positive relationship was found between average time inside the house and urinary CCR in asthmatic children with current ETS at home (ß=0.278, p=0.02). After adjustment for age and gender, average time inside the house was positively related to severe wheeze in asthmatic children with household ETS within 1 month (OR: 1.26, 95%: 1.02-1.64). CONCLUSIONS: Our study suggests that the major source of ETS exposure for children is due to longer period of exposures among children living with adult smokers at home. Home-smoking restrictions that effectively prevent children from being exposed to ETS would be worthwhile.

Lipid profiles in children with and without asthma: interaction of asthma and obesity on hyperlipidemia.

AIMS: The joint effect of obesity and asthma on hyperlipidemia has never been explored. We aim to examine (1) the association of dyslipidemia and asthma, (2) the interaction effect of asthma and obesity on hyperlipidemia, and (3) whether a gender difference existed in the above relationships. METHODS: Between 2009 and 2010, 10- to 15-year-old children were recruited from 7 schools and 2 hospitals in Northern Taiwan. The population consisted of 237 asthmatic children and 225 non-asthmatic controls, and was further divided into four groups: non-obese controls, obese controls, non-obese asthmatics, and obese asthmatics. Measurements included anthropometric measures and blood samples for analysis of metabolic factors. The Cook's criteria were used to define childhood metabolic syndrome. General linear models were used to analyze how lipid profiles were associated with obesity and asthma. RESULTS: Total cholesterol and low density lipoprotein cholesterol levels increased progressively in the group order obese asthmatics>non-obese asthmatics>obese controls>non-obese controls. In boys, low density lipoprotein cholesterol levels were significantly higher in obese asthmatics compared to obese non-asthmatics, with a mean difference of 6.2 mmol/L in the general linear model. We also discovered a significant interactive effect of obesity and asthma on hyperlipidemia in boys (p for interaction=0.03). CONCLUSIONS: Asthma was associated with higher low density lipoprotein cholesterol levels and this association was amplified in overweight and obese subjects. A gender difference was observed in the joint effect of obesity and asthma on hyperlipidemia.

Interleukin-13 genetic variants, household carpet use and childhood asthma.

Interleukin (IL)-13 genetic polymorphisms have shown adverse effects on respiratory health. However, few studies have explored the interactive effects between IL-13 haplotypes and environmental exposures on childhood asthma. The aims of our study are to evaluate the effects of IL-13 genetic variants on asthma phenotypes, and explore the potential interaction between IL-13 and household environmental exposures among Taiwanese children. We investigated 3,577 children in the Taiwan Children Health Study from 14 Taiwanese communities. Data regarding children's exposure and disease status were obtained from parents using a structured questionnaire. Four SNPs were tagged accounting for 100% of the variations in IL-13. Multiple logistic regression models with false-discovery rate (FDR) adjustments were fitted to estimate the effects of IL-13 variants on asthma phenotypes. SNP rs1800925, SNP rs20541 and SNP rs848 were significantly associated with increased risks on childhood wheeze with FDR of 0.03, 0.04 and 0.04, respectively. Children carrying two copies of h1011 haplotype showed increased susceptibility to wheeze. Compared to those without carpet use and h1011 haplotype, children carrying h1011 haplotype and using carpet at home had significantly synergistic risks of wheeze (OR, 2.5; 95% CI, 1.4-4.4; p for interaction, 0.01) and late-onset asthma (OR, 4.7; 95% CI, 2.0-10.9; p for interaction, 0.02). In conclusions, IL-13 genetic variants showed significant adverse effects on asthma phenotypes among children. The results also suggested that asthma pathogenesis might be mediated by household carpet use.

Serum polyfluoroalkyl concentrations, asthma outcomes, and immunological markers in a case-control study of Taiwanese children.

BACKGROUND: Perfluorinated compounds (PFCs) are ubiquitous pollutants. Experimental data suggest that they may be associated with adverse health outcomes, including asthma. However, there is little supporting epidemiological evidence. METHODS: A total of 231 asthmatic children and 225 nonasthmatic controls, all from northern Taiwan, were recruited in the Genetic and Biomarkers study for Childhood Asthma. Structure questionnaires were administered by face-to-face interview. Serum concentrations of 11 PFCs and levels of immunological markers were also measured. Associations of PFC quartiles with concentrations of immunological markers and asthma outcomes were estimated using multivariable regression models. RESULTS: Nine PFCs were detectable in most children (≥ 84.4%), of which perfluorooctane sulfonate (PFOS) was the most abundant (median serum concentrations of 33.9 ng/mL in asthmatics and 28.9 ng/mL in controls). Adjusted odds ratios for asthma among those with the highest versus lowest quartile of PFC exposure ranged from 1.81 (95% CI: 1.02, 3.23) for the perfluorododecanoic acid (PFDoA) to 4.05 (95% CI: 2.21, 7.42) for perfluorooctanic acid (PFOA). PFOS, PFOA, and subsets of the other PFCs were positively associated with serum IgE concentrations, absolute eosinophil counts (AEC), eosinophilic cationic protein (ECP) concentrations, and asthma severity scores among asthmatics. CONCLUSIONS: This study suggests an association between PFC exposure and juvenile asthma. Because of widespread exposure to these chemicals, these findings may be of potential public health concern.

Fine particle, ozone exposure, and asthma/wheezing: effect modification by glutathione S-transferase P1 polymorphisms.

BACKGROUND: There are limited studies on the role of interaction between exposure to ambient air pollution and glutathione-S-transferase (GST) P1 on the risk of asthma/wheezing among children, which provided suggestive, but inconclusive results. METHODS: To assess the joint effect of air pollutants and GSTP1 on asthma/wheezing, we conducted a nationwide cross-sectional study of 3,825 children in Taiwan Children Health Study. The studied determinants were three GSTP1 Ile105Val (rs 1695) genotypes (Ile-Ile; Ile-Val and Val-Val) and expoure to ambient air pollutants. We used routine air-pollution monitoring data for ozone (O(3)) and particles with an aerodynamic diameter of 2.5 µm or less (PM(2.5)). The effect estimates were presented as odds ratios (ORs) per interquartile changes for PM(2.5) and O(3). FINDINGS: In a two-stage hierarchical model adjusting for confounding, the risk of asthma was negatively associated with PM(2.5) (adjusted odds ratio (OR) 0.60; 95% confidence interval (CI) 0.45, 0.82) and O(3) (OR 0.74; 95% CI 0.60, 0.90) among Ile105 homozygotes, but positively associated with PM(2.5) (OR 1.52; 95% CI 1.01, 2.27) and O(3) (OR 1.19; 95% CI 0.91, 1.57) among those with at least one val105 allele (interaction p value = 0.001 and 0.03, respectively). A similar tendency of effect modification between PM(2.5) and O(3) and GSTP1 on wheezing was found. CONCLUSION: Children who carried Ile105 variant allele and exposed to PM(2.5) and O(3) may be less likely to occurrence of asthma/wheezing.

Home dampness, beta-2 adrenergic receptor genetic polymorphisms, and asthma phenotypes in children.

BACKGROUND: Dampness in the home is a strong risk factor for respiratory symptoms and constitutes a significant public health issue in subtropical areas. However, little is known about the effects of dampness and genetic polymorphisms on asthma. METHODS: In 2007, 6078 schoolchildren were evaluated using a standard questionnaire with regard to information about respiratory symptoms and environmental exposure. Multiple logistic regression analyses were performed to assess the effects of home dampness and beta-2-adrenergic receptor (ADRB2) gene polymorphisms on the prevalence of asthma and selected indicators of severity of asthma. RESULTS: The frequency of mildewy odor, the number of walls with water stamp, and the duration of water damage were all associated with being awakened at night due to wheezing. However, no other clear-cut associations were found for any of the other indicators of asthma. Children exposed to mildewy odor with ADRB2 Arg/Arg genotype were associated with being awakened at night due to wheezing (OR=1.95, 95% CI, 1.14-3.36), compared to those without exposure and with the ADRB2 Gly allele. ADRB2 Arg16Gly showed a significant interactive effect with home dampness on being awakened at night due to wheezing and current wheezing, but no significant effect on active asthma and medication use. Frequency and degree of home dampness were also associated with the prevalence of asthma and selected indicators of severity of asthma, in an exposure-response manner among children with ADRB2 Arg/Arg genotype. CONCLUSIONS: Home dampness prevention is one of the important steps of asthma control, especially in children carrying ADRB2 Arg/Arg genotypes.