Filaggrin loss-of-function mutations are associated with food allergy in childhood and adolescence.

BACKGROUND: Filaggrin is an epidermal protein that has a role in skin barrier function. Filaggrin loss-of-function (FLG-LOF) mutations are a significant risk factor for eczema and atopy, but their association with food allergy (FA) is less clear. OBJECTIVE: We explored the longitudinal relationship between 3 common FLG-LOF mutations and FA using the Isle of Wight birth cohort. METHODS: FA diagnosis was based on recognized allergic reactions within 4 hours after exposure to known food allergens. Food allergen sensitization (FAS) was identified by using skin prick tests conducted between 1 and 18 years of age to a range of food allergens. Three FLG mutations were genotyped in 1150 (79%) of 1456 children. The temporal relationships between FA, FAS, and eczema in children with FLG mutations were explored by using path analysis with total, direct, and indirect effect models. RESULTS: There was a significant total effect of FLG-LOF mutations on the risk of FA in later childhood at the ages of 10 (odds ratio, 31.46; 95% CI, 2.86 to >100) and 18 (odds ratio, 4.25; 95% CI, 1.55-11.61) years. Path analysis showed that there was no direct effect of FLG-LOF mutations on FA at any age; however, an indirect effect was found on FA at all ages through eczema and FAS in the earlier years. CONCLUSION: FLG-LOF mutations are associated with FA in older children through eczema and FAS during early childhood. Our results highlight a biologically plausible pathway, which suggests that skin barrier function is important in the development and persistence of FA.

Pre- and perinatal characteristics and breast milk immune markers.

BACKGROUND: Maternal allergy and gestational exposures can alter the concentration of type-1/type-2/T-regulatory markers in breast milk. We tested whether maternal risk factors are related to breast milk immune markers. METHODS: Expecting mothers were enrolled in 2008-2010 in South Carolina in prenatal clinics and classes. Interferon (IFN)-γ-induced protein 10 (CXCL10), CCL11, interleukin (IL)-1ß, IL-4, IL-5, IL-6, CXCL8, IL-10, IL-12(p70), IL-13, transforming growth factor (TGF)-ß1, and immunoglobulin (Ig)A in 115 whey samples were measured by immunoassays. Maternal asthma, eczema, rhinitis, smoking, urogenital infections during gestation, pet exposure, education, race/ethnicity, age, body mass, and the child's birth date and sex were ascertained. The effects of these risk factors on immune markers were estimated using general linear models. RESULTS: Maternal asthma was linked to higher levels of IL-5, rhinitis to lower levels of IL-5 and INF-γ, and eczema to lower levels of IL-6. Gestational smoking was related to increased concentrations of CXCL8 and IL-6. African-American mothers had markedly higher levels of IL-6, IFN-γ, and CXCL8. Urogenital infections, maternal age, body mass, child's sex, and season of birth contributed to the variation. CONCLUSION: The impact of maternal allergies on immune markers in breast milk was small compared with that of maternal nondisease characteristics.

Epidemiologic methods of assessing asthma and wheezing episodes in longitudinal studies: measures of change and stability.

BACKGROUND: In settings in which diseases wax and wane, there is a need to measure disease dynamics in longitudinal studies. Traditional measures of disease occurrence (eg, cumulative incidence) do not address change or stability or are limited to stable cohorts (eg, incidence) and may thus lead to erroneous conclusions. To illustrate how different measures can be used to detect disease dynamics, we investigated sex differences in the occurrence of asthma and wheezing, using a population-based study cohort that covered the first 18 years of life. METHODS: In the Isle of Wight birth cohort (n = 1456), prevalence, incidence, cumulative incidence, positive and negative transitions, and remission were determined at ages 1 or 2, 4, 10, and 18 years. Latent transition analysis was used to simultaneously identify classes of asthma and wheezing (related phenotypes) and characterize transition probabilities over time. Trajectory analysis was used to characterize the natural history of asthma and wheezing. RESULTS: Regarding time-specific changes, positive and negative transition probabilities were more informative than other measures of associations because they revealed a sex switchover in asthma prevalence (P < 0.05). Transition probabilities were able to identify the origin of a sex-specific dynamic; in particular, prior wheezing transitioned to asthma at age 18 years among girls but not among boys. In comparison with latent transition analysis, trajectory analysis did not directly identify a switchover in prevalence among boys and girls. CONCLUSIONS: In longitudinal analyses, transition analyses that impose minimal restrictions on data are needed in order to produce appropriate information on disease dynamics.

Predisposing, Enabling, and Need Factors Associated with Psychotropic Medication and Mental Health Service Use among Children in Out-of-Home Care in the United States: A Scoping Review.

This scoping review aimed to identify predisposing, enabling, and need factors associated with the use of mental health services, including psychotropic medications, among children in out-of-home care in the United States. We searched the PsycInfo, SocINDEX, Medline, and Scopus databases, and 22 studies met inclusion criteria and were systematically analyzed. Among the included studies, 7 studies examined predictors associated with taking psychotropic medications, and 16 examined factors associated with using other mental health services. Significant predisposing, enabling, and need factors associated with greater use of mental health services, including psychotropic medications, were identified. The most frequently identified predisposing factors were child race/ethnicity, age, gender, and maltreatment. Important enabling factors were out-of-home placement type and length of care, and need factors included children's mental/behavioral problems. The results provide insight into maximizing factors facilitating children's use of mental health services to address mental health problems of children in out-of-home care. Further, the results imply the importance of the appropriate use of psychotropic medication (e.g., the type and dosage of medications) among children in out-of-home care. The identified factors can inform child welfare agencies and stakeholders on ways to improve access to mental health services and the appropriate use of psychotropic medications among children in out-of-home care in the United States.

Fatty acids in breast milk associated with asthma-like symptoms and atopy in infancy: a longitudinal study.

OBJECTIVE: The relationship between fatty acids (FAs) in breast milk and the risk of childhood allergies is controversial. We prospectively investigated the relationship between FAs in colostrum and breast milk and asthma-like symptoms (AS) and atopy in infancy. METHODS: Pregnant women were recruited in Columbia and Charleston, South Carolina. Colostrum and mature milk samples were collected. The concentrations of n-3 FAs (eicosapentaenoic acid, α-linolenic acid, docosapentaenoic acid, and docosahexaenoic acid) and n-6 FAs (linoleic acid, arachidonic acid, and eicosadienoic acid) were determined by gas chromatography. AS were ascertained at 6 and 12 months of age and atopy (skin prick test) at 12 months. FAs were dichotomized (high vs. median and low). Generalized estimating equations were used to determine the effect of FAs on repeated AS, compensating for intra-individual correlations and adjusting for confounders. Log-linear regression was used to analyze atopy. RESULTS: FAs were analyzed in 24 colostrum and 78 breast milk samples. High levels of total n-6 (lipid based) FAs in breast milk were associated with an increased risk of AS in infants (risk ratio (RR) = 2.91; 95% confidence interval (CI): 1.37, 6.18), even after controlling for total n-3 FAs (RR = 2.07, 95% CI: 1.12, 3.85). High levels of total n-3 FAs controlling for n-6 FAs decreased the risk of atopy at the age of 12 months. CONCLUSIONS: High levels of total n-6 polyunsaturated fatty acids (PUFAs) in breast milk are associated with an increased risk for AS, whereas high levels of total n-3 PUFAs decreased the risk of atopy. These data suggest that the effects of n-3 and n-6 PUFAs on allergic disorders should be further explored.

Maternal immune markers in serum during gestation and in breast milk and the risk of asthma-like symptoms at ages 6 and 12 months: a longitudinal study.

BACKGROUND: The role of breast milk on the risk of childhood asthma is in dispute. The aim of this prospective study is to determine the relationship of immune markers in maternal serum during gestation and breast milk to asthma-like symptoms (AS) in infancy. METHODS: Pregnant women were recruited in Columbia and Charleston, South Carolina. Blood (median: three weeks before delivery) and breast milk (three weeks after delivery) samples were collected. Concentrations of interferon (IFN)-γ, IFN gamma-induced protein 10 (IP-10 or CXCL10), CCL11, interleukin (IL) 1ß, IL-4, IL-5, IL-6, CXCL8, IL-10, IL-12(p70), IL-13, transforming growth factor (TGF)-ß1, and immunoglobulin (Ig) A in both maternal serum and milk whey were determined via immunoassays. Asthma-like symptoms (AS) of the infant were ascertained at 6 and 12 months, respectively. Generalized estimating equations assessed relative risks (RRs) of immune markers for repeated measurements of AS, considering intra-individual correlations and adjusting for confounders. To provide comparable risk estimates, quartiles of the immune markers were used, except for IL-5 in whey and IgA in serum, which were dichotomized. RESULTS: Of 178 women, 161 provided blood and 115 breast milk samples. IL-12(p70), IL-4, IL-10, IL-1ß, and CCL11 in serum and in whey were not further considered for the statistical analyses since the proportion of non-detectable values was high. Most immune markers in serum and milk whey were moderately or highly correlated; however, IgA was negatively correlated. Infants in the highest quartile of IL-13 in both serum and whey were at a higher risk of AS (RR = 3.02 and 4.18; respectively) compared to infants in the first quartile. High levels of IL-5 in serum and whey was also identified as a risk. In addition, increased secretory IgA and TGF-ß1 in breast milk reduced the risks of AS. CONCLUSIONS: Maternal serum and whey levels of IL-5 and IL-13 are risk markers for AS; whey IgA and TGF-ß1 seem to be protective. Only focusing on breast milk portend that milk cytokines IL-5 and IL-13 have adverse effects. However, similar immune exposures during late gestation and via milk suggest that both may enhance AS among infants.

Material hardship and child neglect risk amidst COVID-19 in grandparent-headed kinship families: The role of financial assistance.

BACKGROUND: COVID-19 has exacerbated material hardship among grandparent-headed kinship families. Grandparent-headed kinship families receive financial assistance, which may mitigate material hardship and reduce child neglect risk. OBJECTIVE: This study aims to examine (1) the association between material hardship and child neglect risk; and (2) whether financial assistance moderates this association in a sample of kinship grandparent-headed families during COVID-19. PARTICIPANTS AND SETTING: Cross-sectional survey data were collected from a convenience sample of grandparent-headed kinship families (not necessarily child welfare involved) (N = 362) in the United States via Qualtrics Panels online survey. METHODS: Descriptive, bivariate, and negative binomial regression were conducted using STATA 15.0. RESULTS: Experiencing material hardship was found to be associated with an increased risk of child neglect, and receiving financial assistance was associated with a decreased risk of child neglect in the full sample and a subsample with household income > $30,000. Receiving financial assistance buffered the negative effect of material hardship on child neglect risk across analytic samples, and receiving SNAP was a significant moderator in the full sample. Among families with a household income ≤ $30,000, receiving SNAP and foster care payments was associated with a decreased risk of child neglect, while receiving TANF and unemployment insurance was associated with an increased risk of child neglect. Among families with household income > $30,000, only receiving SNAP was associated with a decreased risk of child neglect. CONCLUSIONS: This study suggests the potential importance of providing concrete financial assistance, particularly SNAP and foster care payments, to grandparent-headed kinship families in efforts to decrease child neglect risk during COVID-19.

Breastfeeding protects against acute gastroenteritis due to rotavirus in infants.

To assess whether breastfeeding protects against acute gastroenteritis (AGE) due to rotavirus (RV) infection compared to RV-negative AGE (RV-) in children age 0-12 months. Data from a community-based study of children with AGE from 30 pediatric practices in Germany, Switzerland, and Austria were evaluated. A case-control design was conducted with RV-positive AGE (RV+) cases and RV- AGE as controls. Odds ratios and 95% confidence intervals were estimated using log-linear regression models adjusting for child's age, family size, number of siblings, child care attendance, and nationality. A total of 1,256 stool samples were collected from infants with AGE; 315 (25%) were RV+ and 941 RV-. Being breastfed in the period of disease inception reduced the risk of AGE due to RV+ (OR, 0.53; 95% CI, 0.37-0.76). In infants 0-6 months of age, the protective effect was stronger (OR, 0.33; 95% CI, 0.19-0.55) than in 7-12-month-old children. Our study adds to the evidence of a protective concurrent effect of breastfeeding against rotavirus infection in infants, particularly in children 6 months and younger. Breastfeeding is important to diminish rotavirus-related gastroenteritis in infants before vaccination can be introduced.

Applying time series modeling to assess the dynamics and forecast monthly reports of abuse, neglect and/or exploitation involving a vulnerable adult.

BACKGROUND: Application of time series modeling to predict reports related to maltreatment of vulnerable adults can be helpful for efficient early planning and resource allocation to handle a high volume of investigations. The goal of this study is to apply: (1) autoregressive integrated moving average (ARIMA) time series modeling to fit and forecast monthly maltreatment reports accepted for assessment reported to adult protective services (APS), and (2) interrupted time series analysis to test whether the implementation of intake hubs have a significant impact in the number of maltreatment reports after the implementation period. METHODS: A time series analysis on monthly APS intake reports was conducted using administrative data from SC Child and Adult Protective Services between January 2014 and June 2018. Monthly APS data were subjected to ARIMA modeling adjusting for the time period when intake hubs were implemented. The coefficient of determination, normalized SBC, AIC, MSE, and Ljung-Box Q-test were used to evaluate the goodness-of-fit of constructed models. The most parsimonious model was selected to predict the monthly APS intakes from July to December 2018. Poisson regression was fit to examine the association of the implementation of the hubs and the number of intake reports received to APS, adjusting for confounders. RESULTS: Over 24,000 APS intakes accepted for investigation were identified over a period of four calendar years with an increase in the monthly average of APS intakes between 2014 and 2017. An increase in the number of monthly APS intakes was found after the intake hubs were implemented in 2015 (Phase-1) and 2017 (Phase-2). Of all the models tested, an ARIMA (12), 1, 1 model was found to work best after evaluating all fit measures for both models. For Phase-1, the optimum model predicted an average of 488 APS intake reports between July and December 2018, representing a 9% increase from January-June 2018 (median = 445). For Phase-2, the percent increase was 32%. CONCLUSIONS: The implementation of the intake hubs has a significant impact in the number of reports received after the implementation period. ARIMA time series is a valuable tool to predict future reports of maltreatment of vulnerable adults, which could be used to allow appropriate planning and resource allocation to handle a high volume of monthly intake reports.

The association of infant feeding patterns with food allergy symptoms and food allergy in early childhood.

Background: The role of infant feeding for food allergy in children is unclear and studies have not addressed simultaneous exposures to different foods. The goal of this study was to analyze existing data on feeding practices that represent realistic exposure and assess the risk of food allergy symptoms and food allergy in children. Methods: The Infant Feeding Practices Study II conducted by the CDC and US-FDA enrolled pregnant women and collected infant feeding information using nine repeated surveys. Participants were re-contacted after 6 years. Food allergy data were collected at 4, 9, 12, and 72 months. In total, 1387 participants had complete infant feeding pattern data for 6 months and information on food allergy symptoms and doctors' diagnosed food allergy. Feeding patterns constituted six groups: 3-months of feeding at breast followed by mixed feeding, 3-months of breast milk and bottled milk followed by mixed feeding, 1-month of feeding at breast followed by mixed feeding, 6-months of mixed feeding i.e., concurrent feeding of breast milk, bottled milk and formula, 2-3 months of formula followed by formula and solid food, and formula and solid food since the first month. To estimate risks of food allergy, we used linear mixed models, controlling for potential confounders. Results: Of the 328 children with food allergy symptoms in infancy and at 6 years, 52 had persistent symptoms from infancy. Children exposed to mixed feeding had a higher risk of food allergy symptoms (Risk Ratio [RR] 1.54; 95% Confidence Interval [CI] 1.04, 2.29) compared to 3-months of feeding at breast adjusted for confounding. No statistically significant risk of infant feeding patterns was found for doctors' diagnosed food allergy. Paternal allergy posed a higher risk for food allergy symptoms (RR 1.36; 95% CI 1.01, 1.83). Prenatal maternal smoking increased the risk for doctors' diagnosed food allergy (RR 2.97; 95% CI 1.53, 5.79). Conclusions: Analysis of this prospective birth cohort suggest that introduction of multiple feeding source may lead to food allergy symptoms. Future efforts are needed to determine acceptable approaches to improve the ascertainment of food allergy in children and the role of infant feeding.

Duration of breastfeeding is associated with leptin (LEP) DNA methylation profiles and BMI in 10-year-old children.

BACKGROUND: Breastfeeding is protective against many long-term diseases, yet the mechanisms involved are unknown. Leptin gene (LEP) is reported to be associated with body mass index (BMI). On the other hand, breastfeeding duration has been found to be associated with DNA methylation (DNAm) of the LEP gene. Therefore, epigenetic regulation of LEP may represent the mechanism underlying the protective effect of breastfeeding duration against obesity. METHODS: In the Isle of Wight Birth Cohort, peripheral blood DNAm at 23 cytosine-phosphate-guanine sites (CpGs) in the LEP locus in 10-year-old (n = 297) samples and 16 CpGs in 18-year-old (n = 305) samples, were generated using the Illumina Infinium MethylationEPIC and HumanMethylation450 Beadchips respectively and tested for association with breastfeeding duration (total and exclusive) using linear regression. To explore the association between breastfeeding durations and genome-wide DNAm, epigenome-wide association studies (EWASs) and differential methylation region (DMR) analyses were performed. BMI trajectories spanning the first 18 years of life were used as the outcome to test the association with breastfeeding duration (exposure) using multi-nominal logistic regression. Mediation analysis was performed for significant CpG sites. RESULTS: Both total and exclusive breastfeeding duration were associated with DNAm at four LEP CpG sites at 10 years (P value < 0.05), and not at 18 years. Though no association was observed between breastfeeding duration and genome-wide DNAm, DMR analyses identified five significant differentially methylated regions (Sidak adjusted P value < 0.05). Breastfeeding duration was also associated with the early transient overweight trajectory. Furthermore, DNAm of LEP was associated with this trajectory at one CpG site and early persistent obesity at another, though mediation analysis was not significant. CONCLUSIONS: Breastfeeding duration is associated with LEP methylation at age 10 years and BMI trajectory. LEP DNAm is also significantly associated with BMI trajectories throughout childhood, though sample sizes were small. However, mediation analysis did not demonstrate that DNAm of LEP explained the protective effect of breastfeeding against childhood obesity.

Infant feeding pattern in the first six months of age in USA: a follow-up study.

BACKGROUND: Infant feeding may consist of direct breastfeeding (DBF), pumping and bottle feeding (P&F), formula feeding (FF), solid food feeding (SFF), and any combination. An accurate evaluation of infant feeding requires descriptions of different patterns, consistency, and transition over time. METHODS: In United States of America, the Infant Feeding Practice Study II collected information on the mode of feeding on nine occasions in 12 months. We focused on the first 6 months with six feeding occasions. To determine the longitudinal patterns of feeding the latent class transition analyses was applied and assessed the transition probabilities between these classes over time. RESULTS: Over 6 months, 1899 mothers provided feeding information. In month 1 the largest latent class is FF (32.9%) followed by DBF (23.8%). In month 2, a substantial proportion of the FF class included SFF; which increases over time. A not allocated class, due to missing information was identified in months 1-3, transitions to SFF starting in month 4 (8.9%). In month 1, two mixed patterns exist: DBF and P&F combined with FF (13.9%) and DBF combined with P&F (18.7%). The triple combination of DBF, P&F, and FF (13.9%) became FF in month 2 (transition probability: 24.8%), and DBF in combination with P&F (transition probability: 49.1%). The pattern of DBF combined with P&F is relatively stable until month 4, when at least 50% of these infants receive solid food. Only 23-26% of the infants receive direct breastfeeding (DBF) in months 1-4, in month 5-6 SFF is added. Mothers who used FF were less educated and employed fulltime. Mothers who smoke and not residing in the west of the United States were also more likely to practice formula feeding. CONCLUSION: Infant feeding is complex. Breastfeeding is not predominant and we additionally considered the mixed patterns of feeding. To facilitate direct breastfeeding, a substantial increase in the duration of maternal leave is necessary in the United States.

Association Between Infant Feeding Modes and Gastroesophageal Reflux: A Repeated Measurement Analysis of the Infant Feeding Practices Study II.

BACKGROUND: Gastroesophageal reflux in neonates is frequently reported by parents, potentially motivating changes in infant feeding mode and/or addition of solid food. OBJECTIVE: The authors prospectively analyzed associations between repeated measurement of feeding modes and reflux in infancy. METHODS: The Infant Feeding Practices Study II, conducted between 2005 and 2007 (2,841 infants), provides data on reflux and feeding modes at nine time points from months 1 to 12. Feeding modes were defined based on direct breastfeeding, feeding of bottled human milk, formula feeding, their combinations, and use of solid food. Repeated measurements were investigated using 1-month delayed models to estimate risk ratios (RRs) and their 95% confidence intervals (CIs). Risk ratios of different feeding modes were estimated for reflux; addressing a reverse association, RRs for feeding mode were estimated as responses to prior reflux. RESULTS: Compared to direct breastfeeding, combinations with formula feeding showed a statistically significant risk for reflux (bottled human milk plus formula feeding: RR = 2.19, 95% CI [1.11, 4.33]; formula feeding: RR = 1.95, 95% CI [1.39, 2.74]; and mixed breastfeeding plus formula feeding: RR = 1.59, 95% CI [1.40, 2.42]). Addition of solid food was not protective (RR = 1.21, 95% CI [0.86, 1.70]). Analyses of reverse association (reflux → feeding) showed fewer breastfed infants among those with reflux in the prior month. CONCLUSION: Any combination of infant feeding with formula seems to be a risk for reflux. Although breastfeeding was protective, mothers with a child with reflux were more likely to wean their child.

Maternal serum but not breast milk IL-5, IL-6, and IL-13 immune markers are associated with scratching among infants.

BACKGROUND: Scratching in infants is considered to be related to early development of eczema. Little is known about the effects of maternal immune markers on scratching among infants. The objective is to compare the risks related to maternal serum immune markers (IMs) during pregnancy and IMs in breast milk for the occurrence of scratching in infants at 6 and 12 months of age. METHODS: Pregnant women were recruited in Columbia and Charleston, South Carolina. Blood (median 3 weeks prepartum) and breast milk (3 weeks postpartum) samples were collected. The concentrations of interferon (IFN)-γ, IFN gamma-induced protein 10 (IP-10) (or CXCL10), CCL11, interleukin (IL) 1ß, IL-4, IL-5, IL-6, IL-8 (CXCL8), IL-10, IL-12 (p70), IL-13, transforming growth factor (TGF)-ß1, and immunoglobulin (Ig) A in both maternal serum and whey were assayed using optimized immunoassays. Scratching and skin manifestations were ascertained at 6 and 12 months. Generalized estimating equations were used to estimate relative risks (RRs) of IMs for repeated measurements of scratching, considering intra-individual correlations and adjusting for confounders. RESULTS: Of 178 women, 161 provided blood and 115 breast milk samples. IL-1ß, IL-4, IL-10, IL-12, and CCL11 in maternal serum and whey were not analyzed due to a large proportion of non-detectable values. Infants in the highest tertile of IL-6 and IL-13 in maternal serum were at higher risk of scratching (RR 1.73 and 1.84, respectively; p ≤ 0.002) compared to infants in the first tertile; similarly, infants born to mothers with high (versus low) levels of serum IL-5 were also at increased risk (RR 1.60, p = 0.002). None of the breast milk IMs studied were associated with scratching. CONCLUSIONS: Scratching but not doctors diagnosed eczema was associated with higher levels of maternal IL-5, IL-6, and IL-13 during pregnancy. Further investigations are necessary to determine how maternal serum IMs influence infants scratching.

DNA methylation loci associated with atopy and high serum IgE: a genome-wide application of recursive Random Forest feature selection.

BACKGROUND: The prevalence of allergic diseases are increasing worldwide, emphasizing the need to elucidate their pathogeneses. The aims of this study were to use a two-stage design to identify DNA methylation levels at cytosine-phosphate-guanine (CpG) sites across the genome associated with atopy and high serum immunoglobulin E (IgE), then to replicate our findings in an independent cohort. METHODS: Atopy was assessed via skin prick tests and high serum IgE. Methylation levels were measured from whole blood using the Illumina Infinium HumanMethylation450 BeadChip from 18-year-old women (n = 245) and men (n = 122) in the Isle of Wight birth cohort. After data cleaning and processing, and removing probes with possible single nucleotide polymorphisms, DNA methylation levels from 254,460 CpG sites from the 245 women were subjected to recursive Random Forest feature selection for stage 1. The sites selected from stage 1 were tested in stage 2 for associations with atopy and high IgE levels (>200 kU/L) via logistic regression adjusted for predicted cell-type proportions and sex. Sites significantly associated with atopy in stage 2 underwent replication tests in the independent Swedish birth cohort BAMSE (n = 464). RESULTS: In stage 1, 62 sites were selected, of which 22 were associated with atopy in stage 2 (P-value range 6.5E-9 to 1.4E-5) and 12 associated with high IgE levels (P-value range 1.1E-5 to 7.1E-4) at the Bonferroni adjusted alpha (0.05/62 = 0.0008). Of the 19 available sites, 13 were replicated. CONCLUSIONS: We identified 13 novel epigenetic loci associated with atopy and high IgE that could serve as candidate loci for future studies; four were within genes with known roles in the immune response (cg04983687 in the body of ZFPM1, cg18219873 in the 5'UTR of PRG2, cg27469152 in the 3'UTR of EPX, and cg09332506 in the body of COPA).

Oral contraceptives modify the effect of GATA3 polymorphisms on the risk of asthma at the age of 18 years via DNA methylation.

BACKGROUND: The prevalence of asthma in girls increases after puberty. Previous studies have detected associations between sex hormones and asthma, as well as between sex hormones and T helper 2 (Th2) asthma-typical immune responses. Therefore, we hypothesized that exogenous or endogenous sex hormone exposure (represented by oral contraceptive pill (OCP) use and early menarche, respectively) are associated with DNA methylation (DNA-M) of the Th2 transcription factor gene, GATA3, in turn affecting the risk of asthma in girls, possibly in interaction with genetic variants. Blood samples were collected from 245 female participants aged 18 years randomly selected for methylation analysis from the Isle of Wight birth cohort, UK. Information on use of OCPs, age at menarche, and concurrent asthma were assessed by questionnaire. Genome-wide DNA-M was determined using the Illumina Infinium HumanMethylation450 beadchip. In a first stage, we tested the interaction between sex hormone exposure and genetic variants on DNA-M of specific cytosine-phosphate-guanine (CpG) sites. In a second stage, we determined whether these CpG sites interact with genetic variants in GATA3 to explain the risk of asthma. RESULTS: Interactions between OCP use and seven single nucleotide polymorphisms (SNPs) of GATA3 were analyzed for 14 CpG sites (stage 1). The interaction between OCP use and SNP rs1269486 was found to be associated with the methylation level of cg17124583 (P = 0.002, false discovery rate (FDR) adjusted P = 0.04). DNA-M of this same CpG site was also influenced by the interaction between age at menarche and rs1269486 (P = 0.0017). In stage 2, we found that cg17124583 modified the association of SNP rs422628 with asthma risk at the age of 18 years (P = 0.006, FDR adjusted P = 0.04). Subjects with genotype AG showed an increase in average risk ratio (RR) from 0.31 (95% CI: 0.10 to 0.8) to 11.65 (95% CI: 1.71 to 79.5) when methylation level increased from 0.02 to 0.12, relative to genotype AA. CONCLUSION: A two-stage model consisting of genetic variants in the GATA3 gene, OCP use, age at menarche, and DNA-M may explain how sex hormones in women can increase the asthma prevalence after puberty.

The interplay of DNA methylation over time with Th2 pathway genetic variants on asthma risk and temporal asthma transition.

BACKGROUND: Genetic effects on asthma of genes in the T-helper 2 (Th2) pathway may interact with epigenetic factors including DNA methylation. We hypothesized that interactions between genetic variants and methylation in genes in this pathway (IL4, IL4R, IL13, GATA3, and STAT6) influence asthma risk, that such influences are age-dependent, and that methylation of some CpG sites changes over time in accordance with asthma transition. We tested these hypotheses in subsamples of girls from a population-based birth cohort established on the Isle of Wight, UK, in 1989. RESULTS: Logistic regression models were applied to test the interaction effect of DNA methylation and SNP on asthma within each of the five genes. Bootstrapping was used to assess the models identified. From 1,361 models fitted at each age of 10 and 18 years, 8 models, including 4 CpGs and 8 SNPs, showed potential associations with asthma risk. Of the 4 CpGs, methylation of cg26937798 (IL4R) and cg23943829 (IL4) changes between ages 10 and 18 (both higher at 10; P = 9.14 × 10(-6) and 1.07 × 10(-5), respectively). At age 10, the odds of asthma tended to decrease as cg12405139 (GATA3) methylation increased (log-OR = -12.15; P = 0.049); this effect disappeared by age 18. At age 18, methylation of cg09791102 (IL4R) was associated with higher risk of asthma among subjects with genotype GG compared to AG (P = 0.003), increased cg26937798 methylation among subjects with rs3024685 (IL4R) genotype AA (P = 0.003) or rs8832 (IL4R) genotype GG (P = 0.01) was associated with a lower asthma risk; these CpGs had no effect at age 10. Increasing cg26937798 methylation over time possibly reduced the risk of positive asthma transition (asthma-free at age 10 → asthma at age 18; log-OR = -3.11; P = 0.069) and increased the likelihood of negative transition (asthma at age 10 → asthma-free at age 18; log-OR = 3.97; P = 0.074). CONCLUSIONS: The interaction of DNA methylation and SNPs in Th2 pathway genes is likely to contribute to asthma risk. This effect may vary with age. Methylation of some CpGs changed over time, which may influence asthma transition.

Modes of infant feeding and the occurrence of coughing/wheezing in the first year of life.

BACKGROUND: Controversies regarding infant feeding and childhood wheezing may result from insufficient differentiation among various feeding modes. OBJECTIVES: We conducted prospective analyses of associations between the repeated ascertainment of feeding mode and wheezing in infancy. METHODS: The Infant Feeding Practices Study II (2833 infants) provided data on coughing/wheezing episodes (CWEs) at 8 time points and feeding modes at 9 time points from months 1 to 12. Feeding modes were defined as direct breastfeeding, indirect breastfeeding (IBF, bottled breast milk), formula feeding (FF), and their combinations. In concurrent and delayed models using repeated measurements, the relative risks (RR) and their 95% confidence intervals (95% CI) of different feeding modes for CWEs were estimated. In the delayed models, only infants without symptoms were considered at risk for consequent CWE. RESULTS: In a model with a 1-month delay, compared to direct breastfeeding, any other feeding mode showed a statistically significant risk for CWEs (IBF: RR = 1.69, 95% CI [1.05, 2.72]; FF: RR = 1.26, 95% CI [1.08, 1.47]; mixed breast feeding plus FF: RR = 1.25, 95% CI [1.01, 1.55]; and FF and direct breastfeeding: RR = 1.38, 95% CI [1.14, 1.68]). In a concurrent effect model, FF, the combination of FF and IBF, and mixed breastfeeding plus formula were risk factors (RR = 1.38, 95% CI [1.19, 1.59], RR = 1.83, 95% CI [1.27, 2.63], and RR=1.35, 95% CI [1.11, 1.65]; respectively). CONCLUSIONS: Any mode of feeding that includes formula or bottled breast milk seems to be a moderate risk for cough or wheezing episodes in the first 12 months of life.

The interaction of genetic variants and DNA methylation of the interleukin-4 receptor gene increase the risk of asthma at age 18 years.

BACKGROUND: The occurrence of asthma is weakly explained by known genetic variants. Epigenetic marks, DNA methylation (DNA-M) in particular, are considered to add to the explanation of asthma. However, no etiological model has yet been developed that integrates genetic variants and DNA-M. To explore a new model, we focused on one asthma candidate gene, the IL-4 receptor (IL4R). We hypothesized that genetic variants of IL4R in interaction with DNA-M at cytosine-phosphate-guanine (CpG) sites jointly alter the risk of asthma during adolescence. Blood samples were collected at age 18 years from 245 female cohort participants randomly selected for methylation analysis from a birth cohort (n = 1,456, Isle of Wight, UK). Genome-wide DNA-M was assessed using the Illumina Infinium HumanMethylation450 BeadChip. RESULTS: Thirteen single nucleotide polymorphisms (SNPs) and twelve CpG sites of IL4R gene were analyzed. Based on linkage disequilibrium and association with asthma, eight SNPs and one CpG site were selected for further analyses. Of the twelve CpG sites in the IL4R gene, only methylation levels of cg09791102 showed an association with asthma at age 18 years (Wilcoxon test: P = 0.01). Log-linear models were used to estimate risk ratios (RRs) for asthma adjusting for uncorrelated SNPs within the IL4R gene and covariates. Testing for interaction between the eight SNPs and the methylation levels of cg09791102 on the risk for asthma at age 18 years, we identified the statistically significant interaction term of SNP rs3024685 × methylation levels of cg09791102 (P = 0.002; after adjusting for false discovery rate). A total of 84 participants had methylation levels ≤0.88, 112 participants between 0.89 and 0.90, and 35 between 0.91 and 0.92. For the SNP rs3024685 ('CC' vs. 'TT') at methylation levels of ≤0.85, 0.86, 0.90, 0.91, and 0.92, the RRs were 0.01, 0.04, 4.65, 14.76, 14.90, respectively (interaction effect, P = 0.0003). CONCLUSIONS: Adjusting for multiple testing, our results suggest that DNA-M modulates the risk of asthma related to genetic variants in the IL4R gene. The strong interaction of one SNP and DNA-M is encouraging and provides a novel model of how a joint effect of genetic variants and DNA-M can explain occurrence of asthma.

Interaction of prenatal maternal smoking, interleukin 13 genetic variants and DNA methylation influencing airflow and airway reactivity.

BACKGROUND: Asthma is characterized by airflow limitation and airway reactivity (AR). Interleukin-13 (IL-13) is involved in the pathogenesis of asthma. Two functional SNPs, rs20541 and rs1800925, of the IL-13 gene (IL13) have been frequently associated with asthma-related lung functions. However, genetic variation alone does not fully explain asthma risk. DNA-methylation (DNA-M) is an epigenetic mechanism that regulates gene expression and can be influenced by both environment and genetic variants. To explore the interplay of prenatal maternal smoking, genetic variants and DNA-M, we used a two-stage model: (1) identifying cytosine phosphate guanine (CpG) sites where DNA-M is influenced by the interaction between genetic variants and maternal smoking during pregnancy (conditional methQTL (methylation quantitative trait loci)); and (2) determining the effect of the interaction between DNA-M of CpG (from stage 1) and SNPs (modifying genetic variants; modGV) on airflow limitation and AR in 245 female participants of the Isle of Wight birth cohort. DNA-M was assessed using the Illumina Infinium HumanMethylation450 BeadChip. FINDINGS: Six CpG sites were analyzed in stage 1. DNA-M at cg13566430 was influenced by interaction of maternal smoking during pregnancy and rs20541. In stage 2, genotype at rs1800925 interacted with DNA-M at cg13566430 significantly affecting airflow limitation (P = 0.042) and AR (P = 0.01). CONCLUSION: Both genetic variants and environment affect DNA-M. This study supports the proposed two-stage model (methQTL and modGV) to study genetic variants, environment and DNA-M interactions in asthma-related lung function.