Trajectories of IgE sensitization to allergen molecules from childhood to adulthood and respiratory health in the EGEA cohort.

BACKGROUND: Longitudinal studies assessing the association of profiles of allergen-specific IgE (sIgE) sensitization to a large range of allergen molecules and respiratory health are rare. We aimed to assess trajectories of molecular sIgE sensitization profiles from childhood to adulthood and their associations with respiratory health. METHODS: IgE reactivity to microarrayed allergen molecules were measured in childhood (EGEA1) and 12 years later in adult life (EGEA2) among 291 EGEA participants (152 with asthma). At each time point, sIgE sensitization profiles were identified by latent class analysis (LCA) by considering IgE-reactivity to the 38 most prevalent respiratory allergens. The LCA-defined profiles were then studied in association with respiratory health. RESULTS: At baseline, the mean (min-max) age of the population was 11 (4.5-16) years. The LCA identified four sIgE sensitization profiles which were very similar at both time points (% at EGEA1 and EGEA2); A: "no/few allergen(s)" (48%, 39%), B: "pollen/animal allergens" (18%, 21%), C: "most prevalent house dust mite allergens" (22%, 27%) and D: "many allergens" (12%, 13%). Overall, 73% of the participants remained in the same profile from childhood to adulthood. The profiles were associated with asthma and rhinitis phenotypes. Participants of profiles C and D had lower FEV1 % and FEF25-75 % as compared to profile A. Similar patterns of associations were observed for participants with asthma. There was no association with change in lung function. CONCLUSION: Using high-resolution sIgE longitudinal data, the LCA identified four molecular sensitization profiles, mainly stable from childhood to adulthood, that were associated with respiratory health.

Association between lung function of school age children and short-term exposure to air pollution and pollen: the PARIS cohort.

BACKGROUND: Daily levels of ambient air pollution and pollen may affect lung function but have rarely been studied together. We investigated short-term exposure to pollen and air pollution in relation to lung function in school-age children from a French population-based birth cohort. METHODS: This study included 1063 children from the PARIS (Pollution and Asthma Risk: an Infant Study) cohort whose lung function and FeNO measurements were performed at age 8 years old. Exposure data were collected up to 4 days before testing. We estimated daily total pollen concentration, daily allergenic risk indices for nine pollen taxa, as well as daily concentrations of three air pollutants (particulate matter less than 10 µm (PM10), nitrogen dioxide (NO2), ozone (O3)). Children with similar pollen and air pollution exposure were grouped using multidimensional longitudinal cluster analysis. Associations between clusters of pollen and air pollution exposure and respiratory indices (FEV1, FVC, FeNO) were studied using multivariable linear and logistic regression models adjusted for potential confounders. RESULTS: Four clusters of exposure were identified: no pollen and low air pollution (Cluster 1), grass pollen (Cluster 2), PM10 (Cluster 3) and birch/plane-tree pollen with high total pollen count (Cluster 4). Compared with children in Cluster 1, children in Cluster 2 had significantly lower FEV1 and FVC levels, and children from Cluster 3 had higher FeNO levels. For FEV1 and FVC, the associations appeared stronger in children with current asthma. Additional analysis suggested a joint effect of grass pollen and air pollution on lung function. CONCLUSION: Daily ambient chemical and biological air quality could adversely influence lung function in children.

Infant feeding clusters are associated with respiratory health and allergy at school age in the PARIS birth cohort.

BACKGROUND: As infant feeding may influence allergy development, we aimed to identify groups of infants based on feeding practices and to examine their associations with respiratory health/allergy at 8 years in the PARIS birth cohort. METHODS: Data on breastfeeding, consumption of infant formula (regular, pre-/probiotics, partially hydrolysed with hypoallergenic label [pHF-HA], extensively hydrolysed [eHF], soya) and solid food introduction were collected using repeated questionnaires at 1, 3, 6, 9 and 12 months. Infants with similar feeding practices over the first year of life were grouped using multidimensional longitudinal cluster analysis. Respiratory/allergic morbidity was studied at 8 years as symptoms, doctor's diagnoses (asthma, hay fever, eczema, food allergy), and measurement of lung function, FeNO and specific IgE. Associations between feeding-related clusters and respiratory/allergic morbidity were investigated using multivariable logistic and linear regression models adjusted for potential confounders including early respiratory/allergic outcomes and parental history of allergy. RESULTS: Five clusters were identified among 3446 infants: Cluster 1 (45%) mainly fed with regular formula, Cluster 2 (27%) exclusively breastfed during the first 3 months, and three other clusters consuming different types of formula (pre-/probiotics for Cluster 3 [17%], pHF-HA for Cluster 4 [7%], eHF/soya for Cluster 5 [4%]). Compared to Cluster 1, children from Cluster 2 tended to have a lower risk of asthma and children from Cluster 4 had a significant lower lung function (FEV1 , FVC), higher FeNO and higher risk of sensitization at 8 years. CONCLUSION: Early pHF-HA use was negatively associated with objective measures of respiratory/allergic morbidity at school age, while children breastfed for at least 3 months seem protected against asthma at 8 years old.

Emergence of pollen food allergy syndrome in asthmatic children in Paris.

BACKGROUND: Over the last few decades, the level of pollen from birch and homologous trees has increased in parts of Europe. Sensitization to birch pollen allergens (principally Bet v 1) has been associated with food cross-reactivity called pollen food allergy syndrome (PFAS). OBJECTIVE: To evaluate changes in allergic diseases due to IgE sensitization over 25 years in asthmatic children. METHODS: This was a cross-sectional retrospective study conducted in Paris. We analyzed two cohorts of asthmatic children with similar characteristics explored between 1993-1999 (old cohort = OC) and 2012-2018 (recent cohort = RC). RESULTS: 121 children were in the OC and 120 in the RC. An increase in sensitization to tree pollens was found especially for birch pollen, which was 11.6% in the OC and 31% in the RC (P = .0002). Allergic rhinitis prevalence was significantly higher in the RC than in the OC (96% vs 52%, respectively, P < .0001). IgE-mediated food allergy increased from 6% to 16% in the OC and RC, respectively, (P = .01) mainly due to PFAS. In the RC, a higher mean Bet v 1-specific IgE level was observed in children with PFAS compared to children without (105.7 KU/L ± 17.8 and 48.9 kU/L ± 15.7, respectively, P < .05). CONCLUSION: Allergic rhinitis and food allergy with tree pollen sensitization have increased in Paris over 25 years mainly due to PFAS. Environmental factors could be responsible for these modifications as described in the literature.

Determinants of blood eosinophilia in moderate and severe asthmatic patients during childhood: Evidence from the severe asthma molecular phenotype (SAMP) cohort.

BACKGROUND: Asthma is a heterogeneous disease in which the interaction between genetic and environmental factors plays a major role. The significance of blood eosinophil is unclear. The aim of the study was to determine the significance of blood eosinophil count in moderate-to-severe asthmatic children of preschool age and school age. METHODS: This was a prospective cross-sectional study performed from 2011 to 2015 including children from the severe asthma molecular phenotype (SAMP) cohort at Trousseau Hospital (Paris, France). We included children with severe and moderate asthma, or severe and moderate recurrent wheeze, aged from 1 to 15 years at the time of exploration. RESULTS: We analyzed data from 402 children: 248 of preschool age and 154 of school age. Blood eosinophil count third quartile thresholds were 322 and 600 cells/µL for the preschool- and school-age groups, respectively. In multivariate analysis, a blood eosinophil count over this threshold was associated with elevated total IgE (OR = 5.33, P < .01), multiple hospitalizations for asthma attacks (OR = 4.96, P = .03), and a maternal history of asthma (OR = 4.91, P = .01) in preschool children; and with staphylococcal toxin-specific IgE (OR = 2.75, P = .03) in children of school age. Random forest analysis reinforced these results. CONCLUSION: High blood eosinophil count is linked to both atopic features and control of asthma with different parameters associated with these features depending on age.

Mediterranean diet and lung function, sensitization, and asthma at school age: The PARIS cohort.

BACKGROUND: The Mediterranean diet (MD) has known health benefits, but its specific impact on allergy development is unclear. As part of the PARIS birth cohort follow-up, we aimed to investigate the adherence of 8-year-old children to the MD and its association with allergic/respiratory morbidity at school age. METHODS: Diet was assessed using a food frequency questionnaire completed by the parents. Adherence to the MD was assessed based on two scores: the KIDMED index and the Mediterranean Diet Score (MDS). Current allergic diseases (asthma, rhinitis, eczema), lung function indices (FEV1 and FVC), FeNO and specific IgE levels were determined during a health check-up at 8 years. Associations between levels of adherence to the MD and respiratory/allergic morbidity were studied using multivariable logistic and linear regression models adjusted for potential confounders. RESULTS: A total of 975 children were included in the present study, 35.6% with low adherence to the MD, 55.7% with moderate adherence and 8.7% with high adherence according to the KIDMED index. High family socioeconomic status, any breastfeeding at 6 months and consumption of organic food were associated with higher adherence to the MD. Compared with low adherence, high adherence was associated with lower risk of asthma and sensitization at 8 years, as well as higher FEV1 and FVC. CONCLUSION: This study suggests a protective effect of high adherence to the MD on allergic and respiratory morbidity at school age. These results need to be confirmed by further longitudinal analyses. A healthy diet may prevent allergic and respiratory morbidity in school-aged children.

Long-term air pollution exposure is associated with increased severity of rhinitis in 2 European cohorts.

BACKGROUND: Very few studies have examined the association between long-term outdoor air pollution and rhinitis severity in adults. OBJECTIVE: We sought to assess the cross-sectional association between individual long-term exposure to air pollution and severity of rhinitis. METHODS: Participants with rhinitis from 2 multicenter European cohorts (Epidemiological Study on the Genetics and Environment on Asthma and the European Community Respiratory Health Survey) were included. Annual exposure to NO2, PM10, PM2.5, and PMcoarse (calculated by subtracting PM2.5 from PM10) was estimated using land-use regression models derived from the European Study of Cohorts for Air Pollution Effects project, at the participants' residential address. The score of rhinitis severity (range, 0-12), based on intensity of disturbance due to symptoms reported by questionnaire, was categorized into low (reference), mild, moderate, and high severity. Polytomous logistic regression models with a random intercept for city were used. RESULTS: A total of 1408 adults with rhinitis (mean age, 52 years; 46% men, 81% from the European Community Respiratory Health Survey) were included. The median (1st quartile-3rd quartile) score of rhinitis severity was 4 (2-6). Higher exposure to PM10 was associated with higher rhinitis severity (adjusted odds ratio [95% CI] for a 10 µg/m3 increase in PM10: for mild: 1.20 [0.88-1.64], moderate: 1.53 [1.07-2.19], and high severity: 1.72 [1.23-2.41]). Similar results were found for PM2.5. Higher exposure to NO2 was associated with an increased severity of rhinitis, with similar adjusted odds ratios whatever the level of severity. Adjusted odds ratios were higher among participants without allergic sensitization than among those with, but interaction was found only for NO2. CONCLUSIONS: People with rhinitis who live in areas with higher levels of pollution are more likely to report more severe nasal symptoms. Further work is required to elucidate the mechanisms of this association.

Allergic Rhinitis and its Impact on Asthma (ARIA) Phase 4 (2018): Change management in allergic rhinitis and asthma multimorbidity using mobile technology.

Allergic Rhinitis and its Impact on Asthma (ARIA) has evolved from a guideline by using the best approach to integrated care pathways using mobile technology in patients with allergic rhinitis (AR) and asthma multimorbidity. The proposed next phase of ARIA is change management, with the aim of providing an active and healthy life to patients with rhinitis and to those with asthma multimorbidity across the lifecycle irrespective of their sex or socioeconomic status to reduce health and social inequities incurred by the disease. ARIA has followed the 8-step model of Kotter to assess and implement the effect of rhinitis on asthma multimorbidity and to propose multimorbid guidelines. A second change management strategy is proposed by ARIA Phase 4 to increase self-medication and shared decision making in rhinitis and asthma multimorbidity. An innovation of ARIA has been the development and validation of information technology evidence-based tools (Mobile Airways Sentinel Network [MASK]) that can inform patient decisions on the basis of a self-care plan proposed by the health care professional.

Interactive effect between ATPase-related genes and early-life tobacco smoke exposure on bronchial hyper-responsiveness detected in asthma-ascertained families.

BACKGROUND: A positional cloning study of bronchial hyper-responsiveness (BHR) at the 17p11 locus in the French Epidemiological study on the Genetics and Environment of Asthma (EGEA) families showed significant interaction between early-life environmental tobacco smoke (ETS) exposure and genetic variants located in DNAH9. This gene encodes the heavy chain subunit of axonemal dynein, which is involved with ATP in the motile cilia function.Our goal was to identify genetic variants at other genes interacting with ETS in BHR by investigating all genes belonging to the 'ATP-binding' and 'ATPase activity' pathways which include DNAH9, are targets of cigarette smoke and play a crucial role in the airway inflammation. METHODS: Family-based interaction tests between ETS-exposed and unexposed BHR siblings were conducted in 388 EGEA families. Twenty single-nucleotide polymorphisms (SNP) showing interaction signals (p≤5.10-3) were tested in the 253 Saguenay-Lac-Saint-Jean (SLSJ) families. RESULTS: One of these SNPs was significantly replicated for interaction with ETS in SLSJ families (p=0.003). Another SNP reached the significance threshold after correction for multiple testing in the combined analysis of the two samples (p=10-5). Results were confirmed using both a robust log-linear test and a gene-based interaction test. CONCLUSION: The SNPs showing interaction with ETS belong to the ATP8A1 and ABCA1 genes, which play a role in the maintenance of asymmetry and homeostasis of lung membrane lipids.

Gender, prick test size and rAra h 2 sIgE level may predict the eliciting dose in patients with peanut allergy: Evidence from the Mirabel survey.

BACKGROUND: Peanut allergy management is based on active avoidance and access to emergency treatment including self-injectable adrenaline. Knowing the dose at which a patient is likely to react is crucial for risk assessment and could significantly improve management by integrating a personalized approach. OBJECTIVE: To develop a threshold dose distribution curve model from routinely collected data. METHODS: The MIRABEL survey is an observational study of 785 patients with peanut allergy/sensitization conducted in France, Belgium and Luxemburg. The current analysis included the 238 participants for whom medical and oral food challenge data were available. Several statistical models (Kaplan-Meier, Cox model, Weibull and Lognormal with predictive factors, basic Weibull and Lognormal) were compared to select the best model and predictive factor combination associated with the threshold doses. Inferences were made with a Bayesian approach. RESULTS: Patients were mainly children (mean age: 9 years [IQR: 6-11]; 87% < 16 years) and males (62%). Median Ara h2 s IgE was of 8kUA/L [IQR: 1-55] and median skin prick test size of 10 mm [IQR: 7-13]. OFC was positive in 204 patients (86%). The median threshold dose was of 67 mg of peanut protein [IQR: 16-244]. The dose at which 1% of the patients are likely to react with objective symptoms was 0.26 [0.03; 2.24] mg of peanut protein. Gender, size of the skin prick test (SPT) and Ara h 2 specific IgE level had a significant impact on the threshold dose distribution curve. The Cox model was the most effective to predict threshold doses with this combination of factors. Girls react to lower doses than boys with a beta coefficient associated to the risk and a 95% credible interval of 0.44 [0.04; 0.77]. The higher the size of the SPT and the Ara h 2 specific IgE level are, the higher the risk of reacting to a small amount of peanut, with beta coefficients associated to the risk and 95% credible intervals of 0.05 [0.02; 0.08] and 0.01 [0.01; 0.02], respectively. CONCLUSION AND CLINICAL RELEVANCE: According to the model, routinely collected data could be used to estimate the threshold dose. The consequences could be the identification of high-risk patients who are susceptible to react to small amounts of peanut and a personalized management of peanut allergy integrating the risk of allergic reaction. Limitations of this study are that assessors of OFC outcome were aware of SPT and Arah2 results, and a further validation study is required to confirm the predictive value of these parameters.

Google Trends and pollen concentrations in allergy and airway diseases in France.

BACKGROUND: Google Trends (GTs) is a web-based surveillance tool that explores the searching trends of specific queries via Google. This tool proposes to reflect the real-life epidemiology of allergic rhinitis and asthma. However, the validation of GTs against pollen concentrations is missing at the country level. OBJECTIVES: In the present study, we used GTs (a) to compare the terms related to allergy in France, (b) to assess seasonal variations across the country for 5 years and (c) to compare GTs and pollen concentrations for 2016. METHODS: Google Trends queries were initially searched to investigate the terms reflecting pollen and allergic diseases. 13- and 5-year GTs were used in France. Then, 5-year GTs were assessed in all metropolitan French regions to assess the seasonality of GTs. Finally, GTs were compared with pollen concentrations (Réseau National de Surveillance en Aerobiology) for 2016 in seven regions (GTs) and corresponding cities (pollen concentrations). RESULTS: The combination of searches for "allergy" as a disease, "pollen" as a disease cause and "ragweed" as a plant was needed to fully assess the pollen season in France. "Asthma" did not show any seasonality. Using the 5-year GTs, an annual and clear seasonality of queries was found in all regions depending on the predicted pollen exposure for spring and a summer peak but not for winter peaks. The agreement between GT queries and pollen concentrations is usually poor except for spring trees and grasses. Moreover, cypress pollens are insufficiently reported by GTs. CONCLUSIONS: Google Trends cannot predict the pollen season in France.

ARIA pharmacy 2018 "Allergic rhinitis care pathways for community pharmacy": AIRWAYS ICPs initiative (European Innovation Partnership on Active and Healthy Ageing, DG CONNECT and DG Santé) POLLAR (Impact of Air POLLution on Asthma and Rhinitis) GARD Demonstration project.

Pharmacists are trusted health care professionals. Many patients use over-the-counter (OTC) medications and are seen by pharmacists who are the initial point of contact for allergic rhinitis management in most countries. The role of pharmacists in integrated care pathways (ICPs) for allergic diseases is important. This paper builds on existing studies and provides tools intended to help pharmacists provide optimal advice/interventions/strategies to patients with rhinitis. The Allergic Rhinitis and its Impact on Asthma (ARIA)-pharmacy ICP includes a diagnostic questionnaire specifically focusing attention on key symptoms and markers of the disease, a systematic Diagnosis Guide (including differential diagnoses), and a simple flowchart with proposed treatment for rhinitis and asthma multimorbidity. Key prompts for referral within the ICP are included. The use of technology is critical to enhance the management of allergic rhinitis. However, the ARIA-pharmacy ICP should be adapted to local healthcare environments/situations as regional (national) differences exist in pharmacy care.

New perspectives of childhood asthma treatment with biologics.

Asthma is no longer considered as a single disease but rather as a syndrome corresponding to different entities and pathophysiologic pathways. A targeted strategy is part of personalized medicine which aims to better define each patient's phenotype and endotype so as to prescribe the most suitable treatment at an individual level. Omalizumab and, more recently, mepolizumab are the first biologics approved for children (6-18 years). Omalizumab is now widely used to treat severe allergic asthma in children and is highly effective for asthma exacerbations and asthma control with a good safety profile. Moreover, several other drugs-lebrikizumab, dupilumab, tezepelumab, mepolizumab, reslizumab, benralizumab-are used or are being studied in both teenagers and adults and could benefit younger children in the near future. We hypothesize that defining the asthma phenotype/endotype regarding the type and intensity of inflammation, association with allergic or non-allergic comorbidities, and airway remodeling should contribute to the choice of a specific biologic. Pediatric specificities have to be addressed and validated by studies in children. Long-term effectiveness and particularly the impact on the natural history of asthma should also be investigated. Severe asthma in children is a complex disease, and patients have to be referred to a specialized pediatric asthma center to confirm diagnosis and initiate the best treatment strategy which could include biologics while taking into account their high cost.

Unsupervised trajectories of respiratory/allergic symptoms throughout childhood in the PARIS cohort.

BACKGROUND: Natural course and co-occurrence of asthma, eczema, and allergic rhinitis through childhood are still not fully documented. We aim to identify and characterize profiles based on the time course, severity, and apparent triggers of respiratory/allergy symptoms in school-aged children. METHODS: Data on occurrence, severity, and triggers of asthma, rhinitis, and dermatitis symptoms were collected annually during the follow-up of the PARIS birth cohort. Children with similar symptom trajectories until 8-9 years were grouped into profiles using multidimensional (all symptoms considered simultaneously) cluster analysis. Associations between profiles and different health outcomes were analyzed using logistic or linear regression models. RESULTS: Six distinct symptomatic profiles were identified. A profile was defined by persistent dermatitis symptoms, associated with sensitization to food and aeroallergens. Two profiles were characterized by wheezing: one with early transient wheezing and the other with persistent wheezing related to doctor-diagnosed asthma, airway obstruction, and perennial aeroallergen sensitization. Three profiles were characterized by rhinitis symptoms: one non-allergic and two allergic, either with persistent rhinitis symptoms related to allergic multimorbidity and sensitization to perennial aeroallergens, or with late-onset symptoms, related to both pollen and perennial aeroallergens sensitization as well as low lung function. CONCLUSION: This study brings further insights into the developmental profiles of respiratory/allergic outcomes from birth to school age. The identified profiles clearly differed regarding objective features such as diagnosed morbidity, sensitization, or lung function measurements, thus highlighting their biologic and clinical relevance. Allergic rhinitis profiles deserve particular attention, since they were likely to be involved in multimorbidity patterns.

Omalizumab effectiveness in patients with severe allergic asthma according to blood eosinophil count: the STELLAIR study.

Omalizumab is a monoclonal anti-IgE antibody used to treat severe allergic asthma (SAA). The aim of the STELLAIR study was to determine the importance of pre-treatment blood eosinophil count as a predictive measure for response to omalizumab.This retrospective real-life study was conducted in France between December 2015 and September 2016 using medical records of SAA omalizumab-treated patients. Response to omalizumab was assessed by three criteria: physician evaluation, reduction of ≥40% in annual exacerbation rate and a combination of both. Response rate was calculated according to blood eosinophil count measured in the year prior to omalizumab initiation.872 SAA omalizumab-treated patients were included by 78 physicians (723 adults (age ≥18 years) and 149 minors (age 6-17 years)). Blood eosinophil count was ≥300 cells·µL-1 in 52.1% of adults and 73.8% of minors. By physician evaluation, 67.2% of adults and 77.2% of minors were responders and 71.1% adults and 78.5% minors had a ≥40% reduction in the exacerbation rate. In adults, the response rate for combined criteria was 58.4% (95% CI 53.2-63.4%) for blood eosinophils ≥300 cells·µL-1 (n=377) and 58.1% (95% CI 52.7-63.4%) for blood eosinophils <300 cells·µL-1 (n=346).This study shows that a large proportion of patients with SAA have a blood eosinophil count ≥300 cells·µL-1, and suggests that omalizumab effectiveness is similar in "high" and "low" eosinophil subgroups.

Specific IgE and IgG measured by the MeDALL allergen-chip depend on allergen and route of exposure: The EGEA study.

BACKGROUND: The nature of allergens and route and dose of exposure may affect the natural development of IgE and IgG responses. OBJECTIVE: We sought to investigate the natural IgE and IgG responses toward a large panel of respiratory and food allergens in subjects exposed to different respiratory allergen loads. METHODS: A cross-sectional analysis was conducted in 340 adults of the EGEA (Epidemiological study of the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy) (170 with and 170 without asthma) cohort. IgE and IgG responses to 47 inhalant and food allergen components were analyzed in sera using allergen microarray and compared between 5 French regions according to the route of allergen exposure (inhaled vs food allergens). RESULTS: Overall 48.8% of the population had allergen-specific IgE levels of 0.3 ISAC standardized units (ISU) or more to at least 1 of the 47 allergens with no significant differences across the regions. For ubiquitous respiratory allergens (ie, grass, olive/ash pollen, house dust mites), specific IgE did not show marked differences between regions and specific IgG (≥0.5 ISU) was present in most subjects everywhere. For regionally occurring pollen allergens (ragweed, birch, cypress), IgE sensitization was significantly associated with regional pollen exposure. For airborne allergens cross-reacting with food allergens, frequent IgG recognition was observed even in regions with low allergen prevalence (Bet v 1) or for allergens less frequently recognized by IgE (profilins). CONCLUSIONS: The variability in allergen-specific IgE and IgG frequencies depends on exposure, route of exposure, and overall immunogenicity of the allergen. Allergen contact by the oral route might preferentially induce IgG responses.

The emerging landscape of dynamic DNA methylation in early childhood.

BACKGROUND: DNA methylation has been found to associate with disease, aging and environmental exposure, but it is unknown how genome, environment and disease influence DNA methylation dynamics in childhood. RESULTS: By analysing 538 paired DNA blood samples from children at birth and at 4-5 years old and 726 paired samples from children at 4 and 8 years old from four European birth cohorts using the Illumina Infinium Human Methylation 450 k chip, we have identified 14,150 consistent age-differential methylation sites (a-DMSs) at epigenome-wide significance of p < 1.14 × 10-7. Genes with an increase in age-differential methylation were enriched in pathways related to 'development', and were more often located in bivalent transcription start site (TSS) regions, which can silence or activate expression of developmental genes. Genes with a decrease in age-differential methylation were involved in cell signalling, and enriched on H3K27ac, which can predict developmental state. Maternal smoking tended to decrease methylation levels at the identified da-DMSs. We also found 101 a-DMSs (0.71%) that were regulated by genetic variants using cis-differential Methylation Quantitative Trait Locus (cis-dMeQTL) mapping. Moreover, a-DMS-associated genes during early development were significantly more likely to be linked with disease. CONCLUSION: Our study provides new insights into the dynamic epigenetic landscape of the first 8 years of life.

The European Survey on Adverse Systemic Reactions in Allergen Immunotherapy (EASSI): A paediatric assessment.

BACKGROUND: Safety data on 'real-life' allergen immunotherapy (AIT) in children and adolescents is usually extrapolated from studies in adults. METHODS: Patients aged 18 or under initiating aeroallergen AIT were evaluated in a prospective European survey. Patient profiles and systemic reactions (SRs) were recorded. Descriptive, univariate and multivariate analyses were used to identify risk factors for SRs. RESULTS: A total of 1563 patients (mean ± SD age: 11.7 ± 3.9 years; rhinitis: 93.7%; asthma: 61.5%; polysensitization: 62.5%) and 1578 courses of AIT were assessed. Single-allergen AIT was administered in 89.5% of cases (n = 1412; mites: 49%; grass pollen: 25.8%; tree pollen: 8.7%; Alternaria: 4.6%; dander: 0.8%; weed pollen: 0.6%). Subcutaneous AIT (SCIT) was used in 71.4% (n = 1127) of the treatments, including 574 (50.9%) with natural extracts. Sublingual AIT (SLIT) was used for the remaining 451 treatments (drops: 73.8%; tablets: 26.2%). The mean ± SD follow-up period was 12.9 ± 3.3 months. The estimated total number of doses was 19,669 for SCIT and 131,550 for SLIT. Twenty-four patients (1.53%) experienced 29 SRs. Respiratory (55.7%) and skin symptoms (37.9%) were most frequent. Anaphylaxis was diagnosed in 3 SRs (10.3%), and adrenaline was administered in 2 of these cases. In a univariate analysis, the risk of SRs was lower in mite-sensitized patients and higher in cases of pollen polysensitization (>3), grass pollen extracts and the use of natural extracts (vs. allergoids). CONCLUSIONS: In a real-life paediatric setting, AIT is safe. SRs are infrequent and generally not severe. Pollen polysensitization, grass pollen extracts and natural extracts (vs. allergoids) were risk factors for AIT-associated SRs.

Forced midexpiratory flow between 25% and 75% of forced vital capacity is associated with long-term persistence of asthma and poor asthma outcomes.

BACKGROUND: Whether small-airway obstruction contributes to the long-term evolution of asthma remains unknown. OBJECTIVES: Our aim was to assess whether the level of forced midexpiratory flow between 25% and 75% of forced vital capacity (FEF25-75) was associated with the persistence of current asthma over 20 years and the subsequent risk for uncontrolled asthma independently of FEV1. METHODS: We studied 337 participants (142 children and 225 adults) with current asthma (asthma attacks or treatment in the past 12 months) recruited to the Epidemiological Study on the Genetics and Environment of Asthma (EGEA1) and followed up at the 12- and 20-year surveys. Persistent current asthma was defined by current asthma reported at each survey. A lung function test and a methacholine challenge test were performed at EGEA1 and EGEA2. Adjusted odds ratios (ORs) were estimated for FEF25-75 decreased by 10% of predicted value. RESULTS: A reduced level of FEF25-75 at EGEA1 increased the risk of long-term asthma persistence (adjusted OR, 1.14; 95% CI, 1.00-1.29). In children the association remained significant after further adjustment for FEV1 and in participants with FEV1 of greater than 80% of predicted value. A reduced FEF25-75 level at EGEA1 was significantly associated with more severe bronchial hyperresponsiveness (P < .0001) and with current asthma a decade later, with an association that tended to be stronger in those with (adjusted OR, 1.44; 95% CI, 1.14-1.81) compared with those without (adjusted OR, 1.21; 95% CI, 1.05-1.41) asthma exacerbation. CONCLUSION: Our analysis is the first to suggest that small-airway obstruction, as assessed based on FEF25-75, might contribute to the long-term persistence of asthma and the subsequent risk for poor asthma outcomes independently from effects of the large airways.

Loss-of-function mutations in RSPH1 cause primary ciliary dyskinesia with central-complex and radial-spoke defects.

Primary ciliary dyskinesia (PCD) is a rare autosomal-recessive respiratory disorder resulting from defects of motile cilia. Various axonemal ultrastructural phenotypes have been observed, including one with so-called central-complex (CC) defects, whose molecular basis remains unexplained in most cases. To identify genes involved in this phenotype, whose diagnosis can be particularly difficult to establish, we combined homozygosity mapping and whole-exome sequencing in a consanguineous individual with CC defects. This identified a nonsense mutation in RSPH1, a gene whose ortholog in Chlamydomonas reinhardtii encodes a radial-spoke (RS)-head protein and is mainly expressed in respiratory and testis cells. Subsequent analyses of RSPH1 identified biallelic mutations in 10 of 48 independent families affected by CC defects. These mutations include splicing defects, as demonstrated by the study of RSPH1 transcripts obtained from airway cells of affected individuals. Wild-type RSPH1 localizes within cilia of airway cells, but we were unable to detect it in an individual with RSPH1 loss-of-function mutations. High-speed-videomicroscopy analyses revealed the coexistence of different ciliary beating patterns-cilia with a normal beat frequency but abnormal motion alongside immotile cilia or cilia with a slowed beat frequency-in each individual. This study shows that this gene is mutated in 20.8% of individuals with CC defects, whose diagnosis could now be improved by molecular screening. RSPH1 mutations thus appear as a major etiology for this PCD phenotype, which in fact includes RS defects, thereby unveiling the importance of RSPH1 in the proper building of CCs and RSs in humans.