Quantification of IgE antibodies simplifies the classification of allergic diseases in 4-year-old children. A report from the prospective birth cohort study--BAMSE

Prenatal exposure to ambient fine particulate matter and child lung function in the CANDLE cohort

BACKGROUND

Ambient fine particulate matter (PM2.5) exposure adversely impacts child airway health; however, research on prenatal PM2.5 exposure, and child lung function is limited. We investigated these associations in the ECHO-PATHWAYS Consortium, focusing on the role of exposure timing during different phases of fetal lung development.

METHODS

We included 675 children in the CANDLE cohort born between 2007 and 2011 in Memphis, TN, USA. Prenatal exposure to ambient PM2.5 was estimated using a spatiotemporal model based on maternal residential history and averaged over established prenatal periods of lung development. Forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) were measured by spirometry at age 8-9 years. We used linear regression and Bayesian Distributed Lag Interaction Models (BDLIM) to estimate associations between exposure and lung function z-scores, adjusting for maternal/child characteristics, prenatal/postnatal tobacco exposure, and birth year/season, and evaluating effect modification by child sex and allergic sensitization.

RESULTS

The average ambient concentration of PM2.5 during pregnancy was 11.1 µg/m3 (standard deviation:1.0 µg/m3). In the adjusted linear regression and BDLIM models, adverse, but not statistically significant, associations were observed between exposure during the pseudoglandular (5-16 weeks of gestation) and saccular (24-36 weeks) phases of lung development and FEV1 and FVC. The strongest association was between a 2 μg/m3 higher concentration of PM2.5 during the saccular phase and FEV1 z-score (-0.176, 95% Confidence Interval [CI]: -0.361, 0.010). The FEV1/FVC ratio was not associated with PM2.5 in any exposure window. No effect modification by child sex or allergic sensitization was observed.

CONCLUSIONS

We did not find strong evidence of associations between prenatal ambient PM2.5 exposure and child lung function in a large, well-characterized study sample. However, there was a suggested adverse association between FEV1 and exposure during late pregnancy. The saccular phase of lung development might be an important window for exposure to PM2.5.

Long-term ozone exposure and lung function in middle childhood

BACKGROUND

Ozone (O3) exposure interrupts normal lung development in animal models. Epidemiologic evidence further suggests impairment with higher long-term O3 exposure across early and middle childhood, although study findings to date are mixed and few have investigated vulnerable subgroups.

METHODS

Participants from the CANDLE study, a pregnancy cohort in Shelby County, TN, in the ECHO-PATHWAYS Consortium, were included if children were born at gestational age >32 weeks, completed a spirometry exam at age 8-9, and had a valid residential history from birth to age 8. We estimated lifetime average ambient O3 exposure based on each child's residential history from birth to age 8, using a validated fine-resolution spatiotemporal model. Spirometry was performed at the age 8-9 year study visit to assess Forced Expiratory Volume in the first second (FEV1) and Forced Vital Capacity (FVC) as primary outcomes; z-scores were calculated using sex-and-age-specific reference equations. Linear regression with robust variance estimators was used to examine associations between O3 exposure and continuous lung function z-scores, adjusted for child, sociodemographic, and home environmental factors. Potential susceptible subgroups were explored using a product term in the regression model to assess effect modification by child sex, history of bronchiolitis in infancy, and allergic sensitization.

RESULTS

In our sample (n = 648), O3 exposure averaged from birth to age 8 was modest (mean 26.6 [SD 1.1] ppb). No adverse associations between long-term postnatal O3 exposure were observed with either FEV1 (β = 0.12, 95% CI: -0.04, 0.29) or FVC (β = 0.03, 95% CI: -0.13, 0.19). No effect modification by child sex, history of bronchiolitis in infancy, or allergic sensitization was detected for associations with 8-year average O3.

CONCLUSIONS

In this sample with low O3 concentrations, we did not observe adverse associations between O3 exposures averaged from birth to age 8 and lung function in middle childhood.

Chronic Atopic Dermatitis with Eosinophilia Improved by Daesiho-Tang: A Case Report

Purpose

This study is to report a case of chronic atopic dermatitis (AD) with eosinophilia, which did not respond to conventional therapy and was improved by Daesiho-tang (DSHT).

Patients and Methods

The patient visited our clinic with symptoms of atopic dermatitis including skin lesions and pruritus. Based on her symptoms, DSHT was prescribed. At each visit, the Scoring Atopic Dermatitis (SCORAD), Dermatology Life Quality Index (DLQI), and accompanying systemic symptoms (ASS) were measured. Multiple Allergen Simultaneous Test (MAST) was initially performed for 108 allergens and analyzed by Western blotting using an Alternate Scoring Method (ASM) according to the specific IgE concentration. Also, peripheral blood laboratory (Lab) tests were performed three times during the patient's visit.

Results

After taking DSHT, the total SCORAD score improved from 62.9 to 23.5, while the patient's ASS also improved. The DLQI score improved from 19 to 5. The total number of eosinophils in the peripheral blood, which showed a mild increase, recovered from 17.2% (0.98 x103/μL) to 4.5% (0.24 x103/μL). The total IgE slightly decreased, while AST and ALT were also restored to normal ranges.

Conclusion

Based on this case, DSHT is considered a potential alternative treatment for AD.

Allergic disease and sensitization disparity in urban and rural China: A EuroPrevall-INCO study

BACKGROUND

Studies in comparison with allergic diseases and sensitization between rural and urban environments in westernized countries might be biased and not adequately reflect countries undergoing rapid transition.

METHODS

A total of 5542 schoolchildren from urban area and 5139 from rural area were recruited for the EuroPrevall-INCO survey. A subsequent case-control sample with 196 children from urban area and 202 from rural area was recruited for a detailed face-to-face questionnaire and assessment of sensitization. Skin prick tests and serum-specific IgE measurements were used to assess sensitizations against food and aeroallergens. Logistic regression analysis was used to determine associations between risk/protective factors, food adverse reactions (FAR), allergic diseases, and sensitizations.

RESULTS

Prevalence of self-reported allergic diseases, including asthma (6.6% vs.2.5%), rhinitis (23.2% vs.5.3%), and eczema (34.1% vs.25.9%), was higher in urban than in rural children. Urban children had a significantly higher prevalence of FAR and related allergic diseases, and lower food/inhalation allergen sensitization rate, than those of rural children. In urban children, frequent changing places of residency (odds ratio 2.85, 95% confidence interval: 1.45-5.81) and antibiotic usage (3.54, 1.77-7.32) in early life were risk factors for sensitization, while sensitization and family history of allergy were risk factors for allergic diseases. In rural children, exposure to rural environments in early life was protective against both allergen sensitizations (0.46, 0.21-0.96) and allergic diseases (0.03, 0.002-0.19).

CONCLUSION

We observed a disparity in rates of allergic diseases and allergen sensitization between rural and urban children. In addition to family history, the development of allergic diseases and allergen sensitization were associated with specific urban/rural environmental exposures in early life.

Associations of early-life pet ownership with asthma and allergic sensitization: a meta-analysis of >77,000 children from the EU Child Cohort Network

BACKGROUND

Studies examining associations of early-life cat and dog ownership with childhood asthma have reported inconsistent results. Several factors could explain these inconsistencies, including type of pet, timing and degree of exposure.

OBJECTIVE

To study associations of early-life cat and dog ownership with school-age asthma, including the role of type (cat versus dog), timing (never, prenatal or early childhood) and degree (number) of ownership, and the role of allergic sensitisation.

METHODS

We used harmonised data from 77,434 mother-child dyads aged 5-11 years from nine birth cohorts in the EU Child Cohort Network. Associations were examined through the DataSHIELD platform using adjusted logistic regression models, fitted separately for each cohort and combined using random-effects meta-analysis.

RESULTS

Early-life cat and dog ownership ranged between 12-45% and 7-47% respectively, and prevalence of asthma between 2-20%. There was no overall association between either cat or dog ownership and asthma (OR: 0.97 (95% CI: 0.87-1.09) and 0.92 (0.85-1.01), respectively). Timing and degree of ownership did not strongly influence associations. Cat and dog ownership were also not associated with cat- and dog-specific allergic sensitisation (OR: 0.92 (0.75-1.13) and 0.93 (0.57-1.54), respectively). However, cat- and dog-specific allergic sensitisation were strongly associated with school-age asthma (OR: 6.69 (4.91-9.10) and 5.98 (3.14-11.36), respectively). There was also some indication of an interaction between ownership and sensitisation, suggesting that ownership may exacerbate the risks associated with pet-specific sensitisation, but offer some protection against asthma in the absence of sensitisation.

CONCLUSION

Our findings do not support early-life cat and dog ownership in themselves increasing the risk of school-age asthma, but suggest that ownership may potentially exacerbate the risks associated with cat- and dog-specific allergic sensitisation.

Atopic Status in Children with Asthma and Respiratory Allergies—Comparative Analysis of Total IgE, ImmunoCAP Phadiatop/fx5 and Euroimmun Pediatric Immunoblot

Introduction: An atopic status assessment (skin prick test or specific immunoglobulin (sIgE)) in asthmatic children is considered a milestone in identifying potential risk factors and triggers provoking loss of asthma control and asthma exacerbation. Objective: The study aims to perform a comparative analysis of different laboratory methods for a serological assessment of an atopic status in asthma and respiratory allergies in children. Material and methods: A total of 86 children were included, all of whom were diagnosed with bronchial asthma, aged from 5 to 17 years and screened for total IgE level using enzyme-linked immunosorbent assay (ELISA). In 48 randomly selected children, we performed a semi-quantitative serological in vitro assessment of the specific IgE antibodies against food and aeroallergen, using two different laboratory methods—Euroimmun Immunoblot and ImmunoCAP (Phadiatop/fx5). Results: In 70% of the children with a history of allergies, and 65.3% without clinically manifested allergies, multiscreen test ImmunoCAP Phadiatop/fx5 showed positivity and confirmed atopy. Our results showed a significant moderate to strong correlation between multiscreen ImmunoCAP Phadiatop/fx5, and Euroimmun specific IgE titers against aero-allergens—cats, mites, tree mix and food allergens—soy, wheat (р = 0.006), rice, р = 0.090), apple р = 0.007) and peanut. A sensitivity of 63% and specificity of 73.5% was observed for EUROIMMUN Pediatric (food allergens, IgE titer > 1) compared with the gold standard ImmunoCap/fx5. The mean value of total IgE is significantly higher in children with asthma and concomitant with allergic rhinitis compared to those without allergic rhinitis (mean 202.52 U/mL, IQR 102.50 (24.20–363.95) vs. 316.68, IQR 261.00 (109.20–552.50), p = 0.005). Conclusion: Establishing the spectrum of the most common respiratory and food allergens is an essential factor for maintaining asthma control, both through a strategy to avoid allergen exposure and by developing a recommendation plan. The immunoblotting technique is easily applicable in daily clinical and laboratory practice. It is also a cost-effective and reliable alternative to the “gold standard” ImmunoCAP Phadiatop/fx5 in diagnosing atopy in children.

DNA Methylation Levels in Mononuclear Leukocytes from the Mother and Her Child Are Associated with IgE Sensitization to Allergens in Early Life

DNA methylation changes may predispose becoming IgE-sensitized to allergens. We analyzed whether DNA methylation in peripheral blood mononuclear cells (PBMC) is associated with IgE sensitization at 5 years of age (5Y). DNA methylation was measured in 288 PBMC samples from 74 mother/child pairs from the birth cohort ALADDIN (Assessment of Lifestyle and Allergic Disease During INfancy) using the HumanMethylation450BeadChip (Illumina). PBMCs were obtained from the mothers during pregnancy and from their children in cord blood, at 2 years and 5Y. DNA methylation levels at each time point were compared between children with and without IgE sensitization to allergens at 5Y. For replication, CpG sites associated with IgE sensitization in ALADDIN were evaluated in whole blood DNA of 256 children, 4 years old, from the BAMSE (Swedish abbreviation for Children, Allergy, Milieu, Stockholm, Epidemiology) cohort. We found 34 differentially methylated regions (DMRs) associated with IgE sensitization to airborne allergens and 38 DMRs associated with sensitization to food allergens in children at 5Y (Sidak p ≤ 0.05). Genes associated with airborne sensitization were enriched in the pathway of endocytosis, while genes associated with food sensitization were enriched in focal adhesion, the bacterial invasion of epithelial cells, and leukocyte migration. Furthermore, 25 DMRs in maternal PBMCs were associated with IgE sensitization to airborne allergens in their children at 5Y, which were functionally annotated to the mTOR (mammalian Target of Rapamycin) signaling pathway. This study supports that DNA methylation is associated with IgE sensitization early in life and revealed new candidate genes for atopy. Moreover, our study provides evidence that maternal DNA methylation levels are associated with IgE sensitization in the child supporting early in utero effects on atopy predisposition.

IgE allergy diagnostics and other relevant tests in allergy, a World Allergy Organization position paper

Currently, testing for immunoglobulin E (IgE) sensitization is the cornerstone of diagnostic evaluation in suspected allergic conditions. This review provides a thorough and updated critical appraisal of the most frequently used diagnostic tests, both in vivo and in vitro. It discusses skin tests, challenges, and serological and cellular in vitro tests, and provides an overview of indications, advantages and disadvantages of each in conditions such as respiratory, food, venom, drug, and occupational allergy. Skin prick testing remains the first line approach in most instances; the added value of serum specific IgE to whole allergen extracts or components, as well as the role of basophil activation tests, is evaluated. Unproven, non-validated, diagnostic tests are also discussed. Throughout the review, the reader must bear in mind the relevance of differentiating between sensitization and allergy; the latter entails not only allergic sensitization, but also clinically relevant symptoms triggered by the culprit allergen.

Relevance of low specific IgE levels to egg, milk and peanut in infancy

BACKGROUND

IgE sensitization is usually associated with allergy-related diseases, but may also occur in asymptomatic individuals. The clinical importance of IgE antibody concentrations in the interval 0.1-0.34 kU/L in early life in relation to allergy development is poorly evaluated.

OBJECTIVE

To assess the relevance of low specific IgE (s-IgE) to hen's egg, cow's milk and peanut at 6 months of age for development of sensitization and allergy-related disease during early childhood.

METHODS

s-IgE concentrations to relevant allergens from blood samples taken at 6 months and 1, 2 and 5 years from children in the prospective ALADDIN cohort were divided into three categories: non-sensitized (<0.1 kU/L), low sensitized (0.1-0.34 kU/L) and sensitized (≥0.35 kU/L) and allergy-related disease assessed.

RESULTS

A total of 372 children were included in this study. Compared with non-sensitized children at 6 months of age, children with low levels of allergen specific IgE (0.1-0.34 kU/L) to food allergens, especially to egg, at 6 months of age were associated with development of sensitization to aeroallergens at 5 years of age (10/14 [71%] vs 39/250 [15%]). In addition, children with low levels to egg or milk at 6 months were more often sensitized to the respective allergen at 1 year of age and, regarding low levels to egg, also to the development of eczema (6/18 [33%] vs 29/292 [10%]).

CONCLUSION & CLINICAL RELEVANCE

IgE antibody concentrations in the interval 0.1-0.34 kU/L to food allergens in infancy seem to increase the probability of sensitization to aeroallergens and, regarding low levels to egg, also of eczema during early childhood. Thus, IgE levels during the first year of life, although below 0.35 kU/L, can provide additional allergy-related prognostic information.

Asthma biomarkers in the age of biologics

The heterogeneous nature of asthma has been understood for decades, but the precise categorization of asthma has taken on new clinical importance in the era of specific biologic therapy. The simple categories of allergic and non-allergic asthma have given way to more precise phenotypes that hint at underlying biologic mechanisms of variable airflow limitation and airways inflammation. Understanding these mechanisms is of particular importance for the approximately 10% of patients with severe asthma. Biomarkers that aid in phenotyping allow physicians to "personalize" treatment with targeted biologic agents. Unfortunately, testing for these biomarkers is not routine in patients whose asthma is refractory to standard therapy. Scientific advances in the recognition of sensitive and specific biomarkers are steadily outpacing the clinical availability of reliable and non-invasive assessment methods designed for the prompt and specific diagnosis, classification, treatment, and monitoring of severe asthma patients. This article provides a practical overview of current biomarkers and testing methods for prompt, effective management of patients with severe asthma that is refractory to standard therapy.

Cellular and noncellular bloodborne biomarkers in asthma

OBJECTIVE

To provide an overview of studied cellular and noncellular blood-derived asthma biomarkers.

DATA SOURCES

PubMed literature review.

STUDY SELECTIONS

Articles discussing cellular and noncellular bloodborne asthma biomarkers.

RESULTS

Discussed asthma biomarkers include peripheral blood cell counts of T cells, fibrocytes, or granulocytes, as well as levels of cytokines, periostin, IgE, and lipid mediators with or without stimulation. Moreover, this article summarizes the association of various blood biomarkers with the type of airway inflammation, presence of atopy, and dominance of specific T-cell subsets and associated pathways in asthma. Furthermore, biomarkers are here listed according to their proposed clinical use, such as diagnosis, disease phenotyping, classification of severity, assessment of disease control, and monitoring of and predicting treatment response.

CONCLUSION

Further research on asthma biomarkers may improve asthma endotyping and ultimately lead to personalized treatment.

Preeclampsia Associates with Asthma, Allergy, and Eczema in Childhood

RATIONALE

Preeclampsia reflects an unusual increase in systemic inflammation during pregnancy.

OBJECTIVES

We studied associations between preeclampsia and asthma, allergy, and eczema in Copenhagen Prospective Studies on Asthma in Childhood₂₀₀₀ (COPSAC₂₀₀₀) and in national registries.

METHODS

COPSAC₂₀₀₀ is a high-risk birth cohort of 411 Danish children. Asthma, allergy, and eczema were diagnosed prospectively, and lung function measured at age 1 month and 7 years. Sensitization was evaluated at age 6 months, 18 months, 4 years, and 6 years by skin prick tests and IgE measurements. The register-based cohort included 1.7 million children from Danish national registries in the 35-year period 1977-2012. Children born to mothers with preeclampsia were analyzed regarding risk of asthma, allergy, and eczema.

MEASUREMENTS AND MAIN RESULTS

In the COPSAC₂₀₀₀ cohort, 5.6% (n = 23) were diagnosed with preeclampsia. Preeclampsia was associated with increased risk of treatment with inhaled corticosteroids at age 7 years (adjusted odds ratio, 4.01 [95% confidence interval (CI), 1.11-14.43]; P = 0.0337), increased bronchial responsiveness to methacholine (adjusted β-coefficient log-μmol, -0.80 [95% CI, -1.55 to -0.06]; P = 0.0348), and allergic rhinitis (adjusted odds ratio, 4.83 [95% CI, 1.58-14.78]; P = 0.0057) in the 7-year-old children. Furthermore, the children had an increased risk of sensitization to both aeroallergens and food allergens, and increased amount of total IgE during childhood. In the registry-based cohort, 3.7% (n = 62,728) were born to mothers with preeclampsia. Preeclampsia was associated with increased risk of asthma, eczema, and aeroallergen and food allergy, especially pronounced after a duration of preeclampsia of 14 days or more. Maternal asthma increased the risk of preeclampsia.

CONCLUSIONS

Preeclampsia is a shared prenatal risk factor for asthma, eczema, and allergy in childhood pointing toward in utero immune programming of the child.

Biomarkers in asthmatic patients: Has their time come to direct treatment?

Asthma is a heterogeneous disease with multiple phenotypes that have variable risk factors and responses to therapeutics. Mild-to-moderate asthma often responds to traditional medications, whereas severe disease can be refractory to inhaled corticosteroids, long-acting β-agonists, and leukotriene receptor antagonists. There is robust research into the variable phenotypes of asthma. Biomarkers help define the specific pathophysiology of different asthma phenotypes and identify potential therapeutic targets. The following review will discuss the current use of biomarkers for the diagnosis of asthma, triaging the severity of a patient's disease, and the potential efficacy of treatments. This information can be used to define certain patient populations that are more likely to respond to inhaled corticosteroids or biologics. As knowledge of patient phenotypes and endotypes and biological agents to target specific classes of asthma emerge, the ability to provide personalized care to asthmatic patients will follow.

The risk of respiratory symptoms on allergen exposure increases with increasing specific IgE levels

BACKGROUND

The relation between IgE sensitization and allergic respiratory symptoms has usually been evaluated by dichotomizing specific IgE levels. The aim of this study was to evaluate the association between specific IgE levels and risk of symptoms on allergen-related exposure, with special reference to allergen-related asthma-rhinitis comorbidity.

METHODS

We considered 6391 subjects enrolled within the European Community Respiratory Health Survey 2, having information on cat/grass/D. pteronyssinus IgE levels and symptoms on exposure to animals/pollen/dust. The risk of oculonasal/asthmalike/both symptoms was evaluated by a multinomial logistic model.

RESULTS

A clear positive association was observed between specific IgE levels to cat/grass/mite and the risk of symptoms on each allergen-related exposure (test for trend with P < 0.001). This trend was particularly pronounced when considering the coexistence of asthmalike and oculonasal symptoms. Compared to non-sensitized subjects, subjects with specific IgE to cat >= 3.5 kU/l presented relative risk ratios of 11.4 (95% CI 6.7-19.2), 18.8 (8.2-42.8), and 55.3 (30.5-100.2) when considering, respectively, only oculonasal symptoms, only asthmalike symptoms, or both. A similar pattern was observed when considering specific IgE to grass/mite and symptoms on exposure to pollen/dust. Also the proportion of people using inhaled medicines or visiting a general practitioner for breathing problems in the previous year increased with increasing sum of specific IgE to cat/grass/mite.

CONCLUSION

Specific IgE level is the most important predictor of allergen-related symptoms. The risk of both oculonasal/asthmalike symptoms increases with specific IgE levels, suggesting that specific IgE contributes to the 'united airways disease'.

Exposure to 'farming' and objective markers of atopy: a systematic review and meta-analysis

There is growing interest in the 'farm effect' on the spectrum of allergy. Evidence concerning the farm effect on asthma, eczema, and allergic rhinitis has been systematically synthesized, but without a specific focus on objective markers of sensitization. This focus is important, as farm exposures may be related to allergy but not to non-allergic phenotypes of disease. We aimed to systematically review and meta-analyse literature that has investigated associations between farm exposure at any age and objective measures of atopy, that is serum IgE or skin prick tests results. Using predefined inclusion and exclusion criteria, we identified 29 articles for review. IgE levels were measured in either childhood or adulthood by eighteen studies, while skin prick testing was performed in sixteen studies. Newcastle-Ottawa Scale quality assessments indicated that the majority of these studies demonstrated a representative sample of selected participants. Due to significant heterogeneity in study measures and methodology between studies, only few were meta-analysed. This meta-analysis showed a significant protective effect of farm exposure before 1 year of life on allergic sensitization (OR = 0.60 [0.52-0.70]). Farm exposure during childhood was also associated with a reduced risk of sensitization to cat or timothy (OR = 0.60 [0.51-0.70]; OR=0.46 [0.41-0.51]). Studies investigating the effect of farm exposure in adult life could not be meta-analysed, and their results were inconsistent. Insufficient studies investigated food sensitization as an outcome to allow synthesis. The majority of studies included in this review investigated childhood farm exposure, finding evidence to support a protective childhood 'farm effect' against subsequent atopy. There is inconsistent evidence on the association between farm exposure in adulthood and allergic sensitization. Further studies are needed to tease out the exact exposures and timing associated with farming environments that protect against allergic disease.

Hand eczema and atopic dermatitis in adolescents: a prospective cohort study from the BAMSE project

BACKGROUND

There is a well-known association between atopic dermatitis (AD) and hand eczema but less is known about how age at onset, persistence and severity of AD influence the risk of developing hand eczema.

OBJECTIVES

To examine the role of AD in the occurrence of hand eczema in adolescence. In addition, associations between asthma and rhinoconjunctivitis, sensitization to common airborne and food allergens, and hand eczema were studied.

METHODS

From the population-based birth cohort BAMSE, 2927 adolescents who had been followed up repeatedly concerning allergy-related disease were included. Questionnaires identified adolescents with hand eczema at 16 years, and their blood was analysed for specific IgE.

RESULTS

A total of 152 (5·2%) adolescents had hand eczema at the age of 16 years. Many of these adolescents had a history of AD (n = 111; 73·0%) and asthma and/or rhinitis (n = 83; 54·6%), respectively. Children with AD (aged 0-16 years) had more than threefold increased odds ratios (OR) for having hand eczema; those with persistent or severe AD had a crude OR of 6·1 [95% confidence interval (CI) 4·0-9·1] and 5·3 (95% CI 2·9-9·6), respectively.

CONCLUSIONS

We confirm a strong association between AD during childhood and hand eczema in adolescence. Children with persistent or more severe AD are at greater risk of developing hand eczema. Asthma and/or rhinoconjunctivitis, positive specific IgE or age at onset of AD are not associated with hand eczema in adolescence.

Cord blood 25(OH)-vitamin D deficiency and childhood asthma, allergy and eczema: the COPSAC2000 birth cohort study

Background

Epidemiological studies have suggested an association between maternal vitamin D dietary intake during pregnancy and risk of asthma and allergy in the offspring. However, prospective clinical studies on vitamin D measured in cord blood and development of clinical end-points are sparse.

Objective

To investigate the interdependence of cord blood 25-hydroxyvitamin D (25(OH)-Vitamin D) level and investigator-diagnosed asthma- and allergy-related conditions during preschool-age.

Methods

Cord blood 25(OH)-Vitamin D level was measured in 257 children from the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC₂₀₀₀) at-risk mother-child cohort. Troublesome lung symptoms (TROLS), asthma, respiratory infections, allergic rhinitis, and eczema, at age 0–7 yrs were diagnosed exclusively by the COPSAC pediatricians strictly adhering to predefined algorithms. Objective assessments of lung function and sensitization were performed repeatedly from birth.

Results

After adjusting for season of birth, deficient cord blood 25(OH)-Vitamin D level (<50 nmol/L) was associated with a 2.7-fold increased risk of recurrent TROLS (HR = 2.65; 95% CI = 1.02–6.86), but showed no association with respiratory infections or asthma. We saw no association between cord blood 25(OH)-Vitamin D level and lung function, sensitization, rhinitis or eczema. The effects were unaffected from adjusting for multiple lifestyle factors.

Conclusion

Cord blood 25(OH)-Vitamin D deficiency associated with increased risk of recurrent TROLS till age 7 years. Randomized controlled trials of vitamin D supplementation during pregnancy are needed to prove causality.

The relationship between a specific IgE level and asthma outcomes: results from the 2005-2006 National Health and Nutrition Examination Survey

BACKGROUND

Allergen exposure is associated with increased specific IgE (sIgE), and allergen exposure plus sensitization is predictive of asthma outcomes. However, it is not known if sIgE is predictive of asthma outcomes in the absence of exposure data.

OBJECTIVE

To investigate whether IgE to indoor allergens is predictive of and has a dose-response relationship with asthma emergency department (ED) visits and wheeze.

METHODS

In the 2005-2006 National Health and Nutrition Examination Survey, 351 children and 390 adults reported current asthma. Continuous sIgE to 9 indoor allergens were considered. Asthma morbidity in the past year was measured by wheezing. Health care utilization was defined as any asthma ED visits in the past year.

RESULTS

Analyses were adjusted for race, age, education, poverty index ratio and (in adults) tobacco use. In children, ED visits were associated with cockroach (odds ratio [OR] 1.5 [95% CI, 1.1-2 .1), rat (OR 1.9 [95% CI, 1.2-2.8]), and Aspergillus (OR 1.6 [95% CI, 1.001-2.60]). Continuous Aspergillus (OR 1.5 [95% CI, 1.04-2.1), Alternaria (OR 1.4 [95% CI, 1.1-1.6]), and total IgE (OR 1.2 [95% CI, 1.1-1.4]) were associated with wheeze in children. Adult ED visits were associated with sIgE for dust mites (Dermatophagoides pteronyssinus OR 1.6 [95% CI, 1.3-2.1]; Dermatophagoides farinae OR 1.6 [95% CI, 1.3-1.9]), total IgE (OR 1.4 [95% CI, 1.04- 1.9]), and the sum of sIgEs (OR 1.6 [95% CI, 1.2-2.2]).

CONCLUSIONS

Sensitization to particular indoor environmental allergens was found to be a risk factor for wheeze and asthma ED visits. These outcomes increased as the concentration of sIgE to these allergens increased.

Role of biomarkers in understanding and treating children with asthma: towards personalized care

Asthma is one of the most common chronic diseases affecting children. Despite publicized expert panels on asthma management and the availability of high-potency inhaled corticosteroids, asthma continues to pose an enormous burden on quality of life for children. Research into the genetic and molecular origins of asthma are starting to show how distinct disease entities exist within the syndrome of "asthma". Biomarkers can be used to diagnose underlying molecular mechanisms that can predict the natural course of disease or likely response to drug treatment. The progress of personalized medicine in the care of children with asthma is still in its infancy. We are not yet able to apply stratified asthma treatments based on molecular phenotypes, although that time may be fast approaching. This review discusses some of the recent advances in asthma genetics and the use of current biomarkers that can help guide improved treatment. For example, the fraction of expired nitric oxide and serum Immunoglobulin E (IgE) (including allergen-specific IgE), when evaluated in the context of recurrent asthma symptoms, are general predictors of allergic airway inflammation. Biomarker assays for secondhand tobacco smoke exposure and cysteinyl leukotrienes are both promising areas of study that can help personalize management, not just for pharmacologic management, but also education and prevention efforts.

Cord blood Th2-related chemokine CCL22 levels associate with elevated total-IgE during preschool age

BACKGROUND

Early-life immune deviation is suspected in the inception of atopic disease.

OBJECTIVE

To investigate the association between cord blood chemokines and the subsequent development of atopic biomarkers and clinical end-points during the first 6 years of life.

METHODS

The Th1-associated chemokines CXCL10 and CXCL11 and the Th2-associated chemokines CCL17 and CCL22 were assessed in cord blood of asymptomatic at-risk newborn children from the Copenhagen Prospective Study on Asthma in Childhood (COPSAC(2000) ) birth cohort and associated with the longitudinal development of biomarkers and clinical end-points of asthma, eczema, and allergic rhinitis during the first 6 years of life.

RESULTS

Cord blood CCL22 levels were significantly associated to total-IgE levels measured at four time-points during the first 6 years of life; overall odds ratio, 1.54 [CI, 1.25-1.89; P < 0.0001]. CXCL10 and CXCL11 were not associated with development of any atopic disorders or biomarkers.

CONCLUSION AND CLINICAL RELEVANCE

High cord blood levels of the Th2 related chemokine CCL22 were significantly associated with high total- IgE levels during the first 6 years of life, but not with specific sensitization, asthma, eczema or allergic rhinitis. This suggests an inborn skewing of the immune system in healthy newborns developing elevated total- IgE later in life.

Pooling birth cohorts in allergy and asthma: European Union-funded initiatives - a MeDALL, CHICOS, ENRIECO, and GA²LEN joint paper

Long-term birth cohort studies are essential to understanding the life course and childhood predictors of allergy and the complex interplay between genes and the environment (including lifestyle and socioeconomic determinants). Over 100 cohorts focusing on asthma and allergy have been initiated in the world over the past 30 years. Since 2004, several research initiatives funded under the EU Framework Program for Research and Technological Development FP6-FP7 have attempted to identify, compare, and evaluate pooling data from existing European birth cohorts (GA(2)LEN: Global Allergy and European Network, FP6; ENRIECO: Environmental Health Risks in European Birth Cohorts, FP7; CHICOS: Developing a Child Cohort Research Strategy for Europe, FP7; MeDALL: Mechanisms of the Development of ALLergy, FP7). However, there is a general lack of knowledge about these initiatives and their potentials. The aim of this paper is to review current and past EU-funded projects in order to make a summary of their goals and achievements and to suggest future research needs of these European birth cohort networks.

Infant origins of childhood asthma associated with specific molds

BACKGROUND

The specific cause or causes of asthma development must be identified to prevent this disease.

OBJECTIVE

Our hypothesis was that specific mold exposures are associated with childhood asthma development.

METHODS

Infants were identified from birth certificates. Dust samples were collected from 289 homes when the infants were 8 months of age. Samples were analyzed for concentrations of 36 molds that comprise the Environmental Relative Moldiness Index (ERMI) and endotoxin, house dust mite, cat, dog, and cockroach allergens. Children were evaluated at age 7 years for asthma based on reported symptoms and objective measures of lung function. Host, environmental exposure, and home characteristics evaluated included a history of parental asthma, race, sex, upper and lower respiratory tract symptoms, season of birth, family income, cigarette smoke exposure, air conditioning, use of a dehumidifier, presence of carpeting, age of home, and visible mold at age 1 year and child's positive skin prick test response to aeroallergens and molds at age 7 years.

RESULTS

Asthma was diagnosed in 24% of the children at age 7 years. A statistically significant increase in asthma risk at age 7 years was associated with high ERMI values in the child's home in infancy (adjusted relative risk for a 10-unit increase in ERMI value, 1.8; 95% CI, 1.5-2.2). The summation of levels of 3 mold species, Aspergillus ochraceus, Aspergillus unguis, and Penicillium variabile, was significantly associated with asthma (adjusted relative risk, 2.2; 95% CI, 1.8-2.7).

CONCLUSION

In this birth cohort study exposure during infancy to 3 mold species common to water-damaged buildings was associated with childhood asthma at age 7 years.

Neonatal bronchial hyperresponsiveness precedes acute severe viral bronchiolitis in infants

BACKGROUND

Respiratory syncytial virus and other respiratory tract viruses lead to common colds in most infants, whereas a minority develop acute severe bronchiolitis often requiring hospitalization. We hypothesized that such an excessive response to respiratory tract viral infection is caused by host factors reflected in pre-existing increased bronchial responsiveness.

OBJECTIVE

We sought to compare bronchial responsiveness and lung function in 1-month-old neonates who later develop acute severe bronchiolitis with those who do not.

METHODS

We measured infant lung function (n=402) and bronchial responsiveness to methacholine (n=363) using the raised-volume rapid thoracoabdominal compression technique before any respiratory symptoms in 1-month-old neonates from the Copenhagen Prospective Study of Asthma in Childhood birth cohort born to mothers with asthma. The children were prospectively monitored for respiratory symptoms and given a diagnosis of acute severe bronchiolitis according to a fixed algorithm.

RESULTS

Thirty-four (8.5%) infants had acute severe bronchiolitis before 2 years of age, 21 (62%) were hospitalized, and 23 (67%) of the cases were associated with respiratory syncytial virus. Children who later had acute severe bronchiolitis irrespective of viral species had a 2.5-fold increased responsiveness to methacholine (provocative dose of methacholine producing a 15% decrease in transcutaneous oxygen pressure [PD(15)]) at age 1 month compared with control subjects (median PD(15) in cases vs control subjects, 0.13 vs 0.33 μmol; P=.01), whereas differences in baseline airflow were not significant for forced expiratory volume at 0.5 seconds (mean z score for cases vs control subjects, -0.18 vs -0.01; P=.36) and forced expiratory flow at 50% of forced vital capacity (mean z score for cases vs control subjects, -0.37 vs -0.09; P=.13).

CONCLUSION

Bronchial hyperresponsiveness in at-risk neonates precedes acute severe bronchiolitis in response to infections with respiratory tract virus.

Influence of host and environmental factors on wheezing severity in infants: findings from the PARIS birth cohort

BACKGROUND

Determinants of wheezing severity are poorly documented in infants.

OBJECTIVES

To study the determinants of wheezing severity in infants aged 18 months followed-up in the PARIS (« Pollution and Asthma Risk : an Infant Study ») birth cohort.

METHODS

Data on wheezing disorders, medical visits and medications, as well as biological markers of atopy, were collected during a medical examination at age 18 months. Severe wheeze was defined as wheeze that required inhaled corticosteroid and/or hospital-based care. Environmental exposures were assessed prospectively with regular questionnaires. Risk factors for wheeze in the first 18 months of life were assessed by multivariate regression models.

RESULTS

Participation in the medical examination concerned 48.2% of the original cohort. Prevalence of wheeze was 560/1879 (35.7%) and was influenced by male gender, parental history of asthma, siblings, daycare attendance, heavy parental smoking at home, and carpet covered floor in the child's bedroom. Being overweight increased the risk of wheeze by 62% (OR = 1.62, 95%CI 1.13-2.32). In addition, trends towards an increased risk of wheeze were found in infants exposed to daily use of cleaning sprays and to renovation activities. Conversely, the presence of a cat reduced the risk of wheeze (OR = 0.65, 95%CI 0.47-0.89), without any evidence of healthy-pet keeping effect. Severe wheeze concerned 286 of the wheezers (42.7%). The prevalence of severe wheeze was related to atopy, and risk of severe wheeze was in particular increased in infants having eosinophilia (OR = 1.76, 95%CI 1.21-2.55) or being sensitized to ≥ 2 allergens (OR = 1.88, 95%CI 1.13-3.14).

CONCLUSIONS AND CLINICAL RELEVANCE

Whilst risk factors for wheeze before 18 months of age are factors related to infections, indoor air pollution, and being overweight, the severity of wheeze is mainly due to the atopic status of the child. We suggest that atopy should be further considered in the assessment of wheezing severity in infants.

Impact of helminth infection on childhood allergic diseases in an area in transition from high to low infection burden

Background

The effect of helminth infections on allergic diseases is still inconclusive. Furthermore, the effect of helminth infections on childhood allergic diseases in a tropical area where prevalence of helminth infections has undergone dramatic changes is not well documented.

Objective

To investigate the relationship between allergic diseases and helminth infection in a cohort of schoolchildren in an area that has undergone dramatic changes in intensity of helminth infections.

Methods

Children attending grade 5 were recruited from 17 schools in Western Province of Sri Lanka. They were assessed for allergic diseases using the International Study of Asthma and Allergies in Childhood questionnaire. Their serum total IgE (tIgE) and allergen-specific IgE (sIgE) for five common aeroallergens were measured by ImmunoCAP® method and stools were examined for the presence of helminth infections.

Results

A total of 640 children (mean age 10 years) were recruited to the study. Of them, 33.7% had evidence of allergic disease and 15.5% had helminth infections. Majority of infections (68.9%) were of low intensity. A significant relationship between allergic disease and helminth infections was not observed, however, a trend toward protective role of helminth infections against allergic diseases was noted. Multivariate analysis showed helminth infections to be an independent predictor of high tIgE levels whereas allergic disease was not. Allergic sensitization (atopy) was a significant risk factor for allergic disease only among non-infected children (odds ratio 3.025, p = 0.022) but not in infected children. The ratio of sIgE to tIgE was higher in non-infected children.

Conclusion

Though not significant, a reduced risk of allergy in helminth-infected children was observed in this population. A Decrease in intensity of helminth infections may have contributed to the reduced capacity of immune-modulation by helminths in this paediatric population.

Asthma outcomes: biomarkers

BACKGROUND

Measurement of biomarkers has been incorporated within clinical research studies of asthma to characterize the population and associate the disease with environmental and therapeutic effects.

OBJECTIVE

National Institutes of Health institutes and federal agencies convened an expert group to propose which biomarkers should be assessed as standardized asthma outcomes in future clinical research studies.

METHODS

We conducted a comprehensive search of the literature to identify studies that developed and/or tested asthma biomarkers. We identified biomarkers relevant to the underlying disease process progression and response to treatment. We classified the biomarkers as either core (required in future studies), supplemental (used according to study aims and standardized), or emerging (requiring validation and standardization). This work was discussed at an National Institutes of Health-organized workshop convened in March 2010 and finalized in September 2011.

RESULTS

Ten measures were identified; only 1, multiallergen screening to define atopy, is recommended as a core asthma outcome. Complete blood counts to measure total eosinophils, fractional exhaled nitric oxide (Feno), sputum eosinophils, urinary leukotrienes, and total and allergen-specific IgE are recommended as supplemental measures. Measurement of sputum polymorphonuclear leukocytes and other analytes, cortisol measures, airway imaging, breath markers, and system-wide studies (eg, genomics, proteomics) are considered as emerging outcome measures.

CONCLUSION

The working group participants propose the use of multiallergen screening in all asthma clinical trials to characterize study populations with respect to atopic status. Blood, sputum, and urine specimens should be stored in biobanks, and standard procedures should be developed to harmonize sample collection for clinical trial biorepositories.

Elevated eosinophil protein X in urine from healthy neonates precedes development of atopy in the first 6 years of life

RATIONALE

Biomarkers predicting development of atopic disease are needed for targeted preventive measures and to study if disease pathology may be active before onset of symptoms.

OBJECTIVES

To investigate whether eosinophil protein X, leukotriene-C4/D4/E4, and 11β-prostaglandin (PG) F2α (PGD2 metabolite) assessed in urine from healthy at-risk neonates precede development of atopic disease during the first 6 years of life.

METHODS

We measured eosinophil protein X (n = 369), leukotriene-C4/D4/E4 (n = 367), and 11β-PGF2α (n = 366) in urine from 1-month-old children participating in the Copenhagen Prospective Studies on Asthma in Childhood birth cohort. Clinical data on development of allergic sensitization, allergic rhinitis, nasal eosinophilia, blood eosinophilia, eczema, troublesome lung symptoms (significant cough or wheeze or dyspnea), and asthma were collected prospectively until age 6 years. Associations between urinary biomarkers and development of atopic traits were investigated using general estimating equations, logistic regression, and Cox regression.

MEASUREMENTS AND MAIN RESULTS

Eosinophil protein X in the urine of the asymptomatic 1-month-old neonates was significantly associated with development of allergic sensitization (odds ratio, 1.49; 95% confidence interval [CI], 1.08–1.89), nasal eosinophilia (odds ratio, 3.2; 95% CI, 1.2–8.8), and eczema (hazard ratio, 1.4; 95% CI, 1.0–2.0), but not with allergic rhinitis, asthma, or blood eosinophilia. Neither leukotriene-C4/D4/E4 nor 11β-PGF2α was associated with any of the atopic phenotypes.

CONCLUSIONS

Eosinophil protein X in urine from asymptomatic neonates is a biomarker significantly associated with later development of allergic sensitization, nasal eosinophilia, and eczema during the first 6 years of life. These findings suggest activation of eosinophil granulocytes early in life before development of atopy-related symptoms.

Quantification of atopy, lung function and airway hypersensitivity in adults

BACKGROUND

Studies in children have shown that concentration of specific serum IgE (sIgE) and size of skin tests to inhalant allergens better predict wheezing and reduced lung function than the information on presence or absence of atopy. However, very few studies in adults have investigated the relationship of quantitative atopy with lung function and airway hyperresponsiveness (AHR).

OBJECTIVE

To determine the association between lung function and AHR and quantitative atopy in a large sample of adults from the UK.

METHODS

FEV1 and FVC (% predicted) were measured using spirometry and airway responsiveness by methacholine challenge (5-breath dosimeter protocol) in 983 subjects (random sample of 800 parents of children enrolled in a population-based birth cohort enriched with 183 patients with physician-diagnosed asthma). Atopic status was assessed by skin prick tests (SPT) and measurement of sIgE (common inhalant allergens). We also measured indoor allergen exposure in subjects' homes.

RESULTS

Spirometry was completed by 792 subjects and 626 underwent methacholine challenge, with 100 (16.0%) having AHR (dose-response slope>25). Using sIgE as a continuous variable in a multiple linear regression analysis, we found that increasing levels of sIgE to mite, cat and dog were significantly associated with lower FEV1 (mite p = 0.001, cat p = 0.0001, dog p = 2.95 × 10-8). Similar findings were observed when using the size of wheal on skin testing as a continuous variable, with significantly poorer lung function with increasing skin test size (mite p = 8.23 × 10-8, cat p = 3.93 × 10-10, dog p = 3.03 × 10-15, grass p = 2.95 × 10-9). The association between quantitative atopy with lung function and AHR remained unchanged when we repeated the analyses amongst subjects defined as sensitised using standard definitions (sIgE>0.35 kUa/l, SPT-3 mm>negative control).

CONCLUSIONS

In the studied population, lung function decreased and AHR increased with increasing sIgE levels or SPT wheal diameter to inhalant allergens, suggesting that atopy may not be a dichotomous outcome influencing lung function and AHR.

Episodic viral wheeze and multiple trigger wheeze in preschool children: a useful distinction for clinicians?

Accumulating evidence suggest that splitting preschool recurrent wheezing disorders into Episodic (Viral) Wheeze (EVW) and Multiple Trigger Wheeze (MTW) is an oversimplification. There is little evidence that the EVW and MTW phenotypes are related to the longitudinal patterns of wheeze, or to different underlying pathological processes. As the clinical response to inhaled corticosteroids and montelukast varies considerably between individual children with EVW, and between individual patients with MTW, the clinical usefulness of the EVW-MTW approach is doubtful. Based on the currently available evidence, we propose to describe preschool wheeze symptoms not only in terms of temporal pattern, but also in terms of frequency and severity, and age of onset. Relevant associated clinical parameters like atopy and eczema should be described with recognition of age of onset, pattern, and severity. Comparing these data to biomarkers and histopathology may help to improve our understanding of preschool wheezing disorders in the future. Until phenotypes can be described that are associated with different pathobiological process, are related to different longitudinal outcomes, or are clearly different in terms of response to therapy, clinicians are encouraged to take a trial and error approach of different therapeutic agents in preschool children with troublesome recurrent wheeze.

High environmental relative moldiness index during infancy as a predictor of asthma at 7 years of age

BACKGROUND

Mold exposures may contribute to the development of asthma, but previous studies have lacked a standardized approach to quantifying exposures.

OBJECTIVE

To determine whether mold exposures at the ages of 1 and/or 7 years were associated with asthma at the age of 7 years.

METHODS

This study followed up a high-risk birth cohort from infancy to 7 years of age. Mold was assessed by a DNA-based analysis for the 36 molds that make up the Environmental Relative Moldiness Index (ERMI) at the ages of 1 and 7 years. At the age of 7 years, children were evaluated for allergic sensitization and asthma based on symptom history, spirometry, exhaled nitric oxide, and airway reversibility. A questionnaire was administered to the parent regarding the child's asthma symptoms and other potential cofactors.

RESULTS

At the age of 7 years, 31 of 176 children (18%) were found to be asthmatic. Children living in a high ERMI value (≥5.2) home at 1 year of age had more than twice the risk of developing asthma than those in low ERMI value homes (<5.2) (adjusted odds ratio [aOR], 2.6; 95% confidence interval [CI], 1.10-6.26). Of the other covariates, only parental asthma (aOR, 4.0; 95% CI, 1.69-9.62) and allergic sensitization to house dust mite (aOR, 4.1; 95% CI, 1.55-11.07) were risk factors for asthma development. In contrast, air-conditioning at home reduced the risk of asthma development (aOR, 0.3; 95% CI, 0.14-0.83). A high ERMI value at 7 years of age was not associated with asthma at 7 years of age.

CONCLUSIONS

Early exposure to molds as measured by ERMI at 1 year of age, but not 7 years of age, significantly increased the risk for asthma at 7 years of age.

Atopic predisposition of recipients in allergic transfusion reactions to apheresis platelets

BACKGROUND

The biologic mechanisms of allergic transfusion reactions (ATRs) are largely unknown. We sought to compare the atopic predisposition of platelet (PLT) recipients who experienced an ATR to nonreactive control recipients.

STUDY DESIGN AND METHODS

We identified 37 consecutive apheresis PLT recipients who experienced an ATR and 26 matched controls. Total immunoglobulin (Ig)E and aero- and food allergen-specific IgE were quantified in plasma by a blood test for allergies (ImmunoCAP: Phadiatop and Fx5). IgE testing of apheresis PLT supernatants was also performed.

RESULTS

Pruritus and urticaria were manifest in 91.9 and 83.8% of all ATRs, with more severe respiratory symptoms and angioedema occurring in less than 15% of cases. No subject had anaphylaxis. Sex, age, and primary diagnosis were balanced between the two groups. Total and aeroallergen-specific IgE was higher among subjects experiencing an ATR in comparison to control subjects (median total IgE, 55.5 kU/L vs. 8.3 kU/L, p = 0.002; and median aeroallergen-specific IgE, 0.57 kUa/L vs. 0.36 kUa/L, p = 0.046). IgE antibody levels in apheresis products associated with ATRs were similar to control products (p > 0.1 for all IgE tests).

CONCLUSION

Recipient atopic predisposition, as defined by IgE sensitization, is a risk factor associated with ATRs.

Children with allergic and nonallergic rhinitis have a similar risk of asthma

BACKGROUND

Both allergic and nonallergic rhinitis have been associated with increased prevalence of asthma.

OBJECTIVE

To characterize asthma and intermediary asthma endpoints in young children with allergic and nonallergic rhinitis.

METHODS

Thirty-eight 7-year-old children with allergic rhinitis, 67 with nonallergic rhinitis, and 185 without rhinitis from the Copenhagen Prospective Study on Asthma in Childhood birth cohort were compared for prevalence of asthma, eczema, food sensitization, filaggrin null-mutations, total IgE, blood eosinophil count, fractional exhaled nitric oxide (FeNO), lung function, and bronchial responsiveness.

RESULTS

Children with allergic rhinitis compared with asymptomatic controls had increased prevalence of asthma (21% vs 5%; P = .002), food sensitization (47% vs 13%; P < .001), and eczema (66% vs 43%; P = .01) and increased total IgE (155 kU/L vs 41 kU/L; P < .001), blood eosinophil count (0.46 x 10(9)/L vs 0.30 x 10(9)/L; P = .01), FeNO (15.9 ppb vs 6.6 ppb; P < .001), and bronchial hyperresponsiveness (23% vs 9%; P = .008). Filaggrin null-mutations were associated with allergic rhinitis (odds ratio, 3.3; 95% CI, 1.3-8.3) but did not modify these associations. Children with nonallergic rhinitis also had increased asthma prevalence (20% vs 5%; P = .001) but showed no association with filaggrin null-mutations, eczema, food sensitization, total IgE, blood eosinophil count, FeNO, or bronchial responsiveness.

CONCLUSION

Asthma is similarly associated with allergic and nonallergic rhinitis, suggesting a link between upper and lower airways beyond allergy associated inflammation. Only children with allergic rhinitis had increased bronchial responsiveness and elevated FeNO, suggesting different endotypes of asthma symptoms in young children with allergic and nonallergic rhinitis.

Asthma prediction in school children; the value of combined IgE-antibodies and obstructive airways disease severity score

BACKGROUND

Allergic sensitisation increases the risk for asthma development. In this prospective birth cohort (Environment and Childhood Asthma) study, we hypothesized that combining quantitative measures of IgE antibodies (Sigma-IgE) and Severity score of obstructive airways disease (OAD) at 2 years of age (Severity score) is superior to predict current asthma (CA) at 10 years than either measure alone. Secondarily, we assessed if gender modified the prediction of CA.

METHODS

A follow-up study at 10 years of age was performed in 371 2-year-old children with recurrent (n = 219) or no (n = 152) bronchial obstruction with available serum analysed for Sigma-IgE to common food and inhalant allergens through a panel test, Phadiatop Infant) (Phadia, Uppsala, Sweden). Clinical variables included allergic sensitisation and exercise testing to characterise children with CA vs not CA at 10 years and the Severity score (0-12, 0 indicating no OAD) was used to assess risk modification.

RESULTS

Severity score alone explained 24% (Nagelkerke R(2) = 0.24) of the variation in CA, whereas Sigma-IgE explained only 6% (R(2) = 0.06). Combining the two increased the explanatory capacity to R(2) = 0.30. Gender interacted significantly with Sigma-IgE; whereas Severity score predicted CA in both genders, the predictive capacity of Sigma-IgE for CA at 10 years was significant in boys only.

CONCLUSION

Combining Sigma-IgE to inhalant allergens and Severity score at 2 years was superior to predict asthma at 10 years than either alone. Severity score predicted CA in both genders, whereas Sigma-IgE significantly predicted CA in boys only.

The presence of serum anti-Ascaris lumbricoides IgE antibodies and of Trichuris trichiura infection are risk factors for wheezing and/or atopy in preschool-aged Brazilian children

BACKGROUND

The elucidation of factors that trigger the development of transient wheezing in early childhood may be an important step toward understanding the pathogenesis of asthma and other allergic diseases later in life. Transient wheezing has been mainly attributed to viral infections, although sensitisation to aeroallergens and food allergens may occur at an early age. In developing countries, intestinal helminthic infections have also been associated with allergy or atopy-related disorders.

OBJECTIVE

The aim of this study was to explore the association of Trichuris trichiura and Ascaris lumbricoides infections with wheezing and atopy in early childhood.

STUDY DESIGN

A cross-sectional study using a Portuguese-language ISAAC phase I questionnaire, adapted for preschool-aged children, nested in a cohort study of childhood diarrhoea, was conducted on 682 children. Two faecal samples per child were examined for the presence of intestinal helminthic infection. IgE antibodies against three allergenic preparations (Dermatophagoides pteronyssinus, Blomia tropicalis and common child food), as well as against A. lumbricoides antigens, were measured in a sub-sample of these children, whose parents allowed the procedure. Atopy was defined by the presence of levels of serum IgE antibodies ≥0.35 kU/L against at least one of the three tested allergenic preparations.

RESULTS

Active T. trichiura infection but not A. lumbricoides infection was positively associated with wheezing in the total studied children population [adjusted OR = 2.60; CI = 1.54;4.38] and in the atopic children sub-population [adjusted OR = 3.07; CI = 1.00;9.43]. The association with atopy was also positive and statistically significant only in the brute analysis [OR = 2.13; CI = 1.03;4.40]. Anti-A. lumbricoides IgE antibodies, but not current A. lumbricoides infection, were positively associated with wheezing in atopic children [adjusted OR = 2.01; CI = 1.00;4.50] and in non-atopic children [adjusted OR = 3.07; CI = 1.13;8.35] and it was also associated with atopy [adjusted OR = 7.29; CI = 3.90; 13.4]. On the other hands, reports of wheezing were not significantly associated with atopy.

CONCLUSIONS

These data corroborate previous studies showing that wheezing is predominantly associated with infection in early childhood and shows that anti-A. lumbricoides IgE antibodies, but not active Ascaris infections, are associated with wheezing and atopy. Additionally, the data demonstrate that T. trichiura infection may play a role in the pathogenesis of atopic wheezing in early childhood.

Cord blood versus age 5 mononuclear cell proliferation on IgE and asthma

BACKGROUND

Fetal immune responses following exposure of mothers to allergens during pregnancy may influence the subsequent risk of childhood asthma. However, the association of allergen-induced cord blood mononuclear cell (CBMC) proliferation and cytokine production with later allergic immune responses and asthma has been controversial. Our objective was to compare indoor allergen-induced CBMC with age 5 peripheral blood mononuclear cell (PBMC) proliferation and determine which may be associated with age 5 allergic immune responses and asthma in an inner city cohort.

METHODS

As part of an ongoing cohort study of the Columbia Center for Children's Environmental Health (CCCEH), CBMCs and age 5 PBMCs were cultured with cockroach, mouse, and dust mite protein extracts. CBMC proliferation and cytokine (IL-5 and IFN-gamma) responses, and age 5 PBMC proliferation responses, were compared to anti-cockroach, anti-mouse, and anti-dust mite IgE levels, wheeze, cough, eczema and asthma.

RESULTS

Correlations between CBMC and age 5 PBMC proliferation in response to cockroach, mouse, and dust mite antigens were nonsignificant. Cockroach-, mouse-, and dust mite-induced CBMC proliferation and cytokine responses were not associated with allergen-specific IgE at ages 2, 3, and 5, or with asthma and eczema at age 5. However, after adjusting for potential confounders, age 5 cockroach-induced PBMC proliferation was associated with anti-cockroach IgE, total IgE, and asthma (p < 0.05).

CONCLUSION

In contrast to allergen-induced CBMC proliferation, age 5 cockroach-induced PBMC proliferation was associated with age 5 specific and total IgE, and asthma, in an inner-city cohort where cockroach allergens are prevalent and exposure can be high.

Elevated exhaled nitric oxide in high-risk neonates precedes transient early but not persistent wheeze

RATIONALE

Elevated fractional exhaled nitric oxide (Fe(NO)) concentration has been suggested to predict early childhood wheeze and sensitization.

OBJECTIVES

To investigate the association between Fe(NO) in asymptomatic neonates and the development of wheeze patterns and atopic intermediary phenotypes in the first 6 years of life.

METHODS

We measured Fe(NO) in 253 healthy 1-month-old neonates from the Copenhagen Prospective Study on Asthma in Childhood birth cohort and monitored prospectively wheezy episodes by daily diary cards during the first 6 years of life. Total IgE, specific IgE, and blood eosinophil count were assessed at age 6 months, 4 years, and 6 years. Associations were studied by Cox regression, logistic regression, and generalized linear models.

MEASUREMENTS AND MAIN RESULTS

Increased neonatal Fe(NO) level was significantly associated with the development of recurrent wheeze in the first year of life (hazard ratio, 2.63; 95% confidence interval, 1.1 to 6.2; P = 0.026) but not thereafter. The association was unaffected by environmental tobacco smoke exposure. Fe(NO) was not associated with elevated levels of total IgE, specific IgE, or blood eosinophil count at any age point and was unrelated to neonatal lung function.

CONCLUSIONS

An elevated Fe(NO) level in asymptomatic neonates born to mothers with asthma preceded the development of transient early wheezing, but not persistent wheezing during preschool age, and was unrelated to atopy. This suggests an early disease process other than small airway caliber contributing to the transient wheezing phenotype.

Cat sensitization identified by recombinant Fel d 1 several years before symptoms--results from the BAMSE cohort

Exposure to cat is one of the most important causes of allergic disease. The objective of this study was to investigate IgE reactivity to the recombinant major cat allergen, rFel d 1, as an early marker of cat sensitization. Based on questionnaires, 144 children with allergic symptoms due to cat, or where such symptoms were suspected, were selected from the birth cohort BAMSE and allocated into three study groups. Blood samples taken at age 4 and 8 yrs were analysed for IgE to rFel d 1 and cat dander extract (CDE) by quantitative ELISA (cut-off limit 0.037 kU(A)/l) and the ImmunoCAP System (cut-off limit 0.35 kU(A)/l), respectively. At 4 yrs, 25/33 children with certain allergic symptoms to cat had IgE to both rFel d 1 and CDE, while 14/42 of those suspecting symptoms at 4 had IgE to rFel d 1 and 9/42 to CDE. In a group developing symptoms after 4 yrs, 60/69 had IgE to rFel d 1 and 57/69 to CDE at 8, while 33/69 had IgE to rFel d 1 already at 4 and 26/69 to CDE. This was the only one of the three study groups where a significant increase in the IgE levels to rFel d 1 was found from 4 to 8 yrs (p < 0.001), even when only children with IgE to rFel d 1 already at 4 were included (p < 0.001). We show that the single major cat allergen rFel d 1 is at least as good as CDE in the diagnosis of cat allergy in childhood. With a sensitive rFel d 1 assay cat sensitization can be detected several years before symptoms to cat are reported.

Objective assessments of allergic and nonallergic rhinitis in young children

BACKGROUND

Allergic and nonallergic rhinitis are common childhood disorders.

OBJECTIVE

To study nasal eosinophilia and nasal airway patency in young children with allergic and nonallergic rhinitis to assess the pathology behind such diagnoses.

METHODS

We investigated 255 children at six years of age from the Copenhagen Prospective Study on Asthma in Childhood birth cohort assessing rhinitis history, specific immunoglobulin E relevant to rhinitis symptoms, nasal eosinophilia and nasal airway patency by acoustic rhinometry before and after decongestion. Associations were studied in a multivariate graphical model corrected for gender, height and nasal steroid usage.

RESULTS

Allergic rhinitis was significantly and directly associated with irreversible nasal airway obstruction (reduced decongested nasal airway patency) (P = 0.004), whereas nonallergic rhinitis was not. Both allergic rhinitis (P = 0.000) and nonallergic rhinitis (P = 0.014) were directly and significantly associated with nasal eosinophilia, but this association was stronger for allergic rhinitis.

CONCLUSION

Allergic rhinitis and nonallergic rhinitis are of different pathologies as suggested from their different associations not only to allergy but importantly also to irreversible nasal airway obstruction and eosinophilic inflammation. Allergic rhinitis was significantly associated with nasal eosinophilia and irreversible nasal airway obstruction suggesting chronic inflammation and structural remodeling of the nasal mucosa in children at the age of 6 years. Nonallergic rhinitis exhibited no change in the nasal airway patency, but some nasal mucosal eosinophilia albeit less than children with allergic rhinitis.

Phadiatop infant in the diagnosis of atopy in children with allergy-like symptoms

Background and Objective. Allergy-like symptoms such as wheezing and eczema are common in young children and an early diagnosis is important to initiate correct management. The objective of this study was to evaluate the diagnostic performance of Phadiatop Infant, an in vitro test for determination of early sensitisation to food and inhalant allergens. Patients and Methods. The study was conducted, retrospectively, using frozen sera from 122 children (median age 2.7 years) admitted to the hospital with suspected allergic symptoms. The doctor's diagnosis atopic/nonatopic was based on routinely used procedures such as clinical evaluation, SPT, total and allergen-specific IgE antibodies. The performance of Phadiatop Infant was evaluated in a blinded manner against this diagnosis. Results. Eighty-four of the 86 children classified as atopic showed a positive Phadiatop Infant test. Thirty-six were classified as nonatopic, 32 of who had a negative test. With a prevalence of atopy of 70% in this population, this gives a sensitivity of 98%, a specificity of 89%, and a positive and negative predictive value of 95% and 94%, respectively. Conclusion. The results from the present study suggest that Phadiatop Infant could be recommended as a complement to the clinical information in the differential diagnosis on IgE-mediated disease in young children with allergy-like symptoms.

Anti-cockroach and anti-mouse IgE are associated with early wheeze and atopy in an inner-city birth cohort

BACKGROUND

The relationships between cockroach and mouse allergen exposure, anti-cockroach and anti-mouse IgE, and wheeze, rhinitis, and atopic dermatitis in children as young as age 3 years are of public health importance but have not been thoroughly evaluated.

OBJECTIVE

We hypothesized that inner-city children might have anti-cockroach and anti-mouse IgE by age 3 years, and their presence would be associated with respiratory and atopic symptoms.

METHODS

Children were followed prospectively from birth through age 3 years (n = 404). Residential levels of cockroach and mouse allergens, sera levels of anti-cockroach and anti-mouse IgE, and parental report of wheeze, rhinitis, and atopic dermatitis were measured.

RESULTS

The odds of early wheeze were significantly higher among children who had IgE to cockroach (odds ratio [OR], 3.3; 95% CI, 1.8-6.2), mouse (OR, 4.6; 95% CI, 2.3-9.0), or both (OR, 9.7; 95% CI, 3.4-27.3). The odds of rhinitis or atopic dermatitis were also higher among children with IgE to cockroach, mouse, or both. Higher IgE class to cockroach and mouse was associated with wheeze and atopic dermatitis (tests for trend, P < .002).

CONCLUSIONS

Children age 2 to 3 years who have anti-cockroach and anti-mouse IgE are at increased risk of wheeze and atopy. Moreover, a dose-response relationship was found between higher IgE class and increased prevalence of wheeze, rhinitis, or atopic dermatitis. These findings indicate the importance of reducing exposure to cockroach and mouse allergens for susceptible children.

Specific IgE serum concentration is associated with symptom severity in children with seasonal allergic rhinitis

BACKGROUND

The impact of allergen-specific and total IgE serum levels before and during the pollen season on symptom severity as well as efficacy of treatment with anti-IgE requires further delineation.

METHODS

Birch and grass pollen allergic patients aged 6-17 years with seasonal allergic rhinitis (SAR) were analyzed for the association of IgE serum concentration with symptom severity and rescue medication use (combination: symptom load, SL) during the grass pollen season. Reference group A (n = 53) received placebo, while group B (n = 54) received Omalizumab (anti-IgE) monotherapy before and during the grass pollen season.

RESULTS

Patients on placebo with high baseline specific grass pollen IgE (>50 kU/l) had a significantly higher SL compared with those with low IgE levels (< or =50 kU/l): SL 1.28 vs 0.61, P = 0.015. This association was nonexistent in patients treated with anti-IgE. In contrast, baseline total IgE levels did not correlate with SL in any group. Patients with anti-IgE treatment and high free total IgE levels (>16.7 ng/ml) had a significantly higher SL compared with those with low free total IgE levels (< or =16.7 ng/ml): SL 0.63 vs 0.23, P = 0.031.

CONCLUSIONS

Baseline specific IgE, but not total IgE, is associated with symptom severity during the pollen season in children with SAR. Likewise, the symptom load in SAR patients with anti-IgE correlates with free total IgE levels. Although further research in larger populations is needed to confirm our findings, our data suggest that specific IgE can be used as a parameter for patient selection for this kind of treatment.

Sensitization to inhalant allergens between 4 and 8 years of age is a dynamic process: results from the BAMSE birth cohort

BACKGROUND

There is limited knowledge of the development of IgE-antibody levels over time in childhood, with respect to persistency and co-sensitization to specific inhalant allergens.

METHODS

Data from 2033 children participating in the BAMSE birth cohort was used. Background factors and clinical parameters were obtained and IgE antibody (ab) levels to eight common airborne allergens were measured (>or=0.35 kU(A)/L) when the children were 4 and 8 years of age.

RESULTS

Between 4 and 8 years the proportion of children sensitized to any of the inhalant allergens tested increased from 15% to 25%. At 4 years IgE-ab to birch and cat dominated, whereas at the age of 8, there was a considerable increase in the proportion of sensitization to timothy and dog. Except for mites and moulds, IgE-ab levels to all aeroallergens increased significantly between 4 and 8 years among those already sensitized at 4. Transient sensitization to inhalant allergen was uncommon. Furthermore, sensitization to birch pollen at 4 years increased the risk for becoming sensitized to timothy, cat and dog later in life. Such an association was not observed among those sensitized primarily to animal dander.

CONCLUSIONS

There is a prominent process of sensitization at pre-school age to inhalant allergens, and in Northern Europe sensitization to birch pollen early in life seems to be important for this process. Such a process has a probable impact on the development of allergic disease in the growing child.

Use of Phadiatop Infant in diagnosis of specific sensitization in young children with wheeze or eczema

Wheezing and eczema are common symptoms in young children and it is important to disclose sensitization for correct management. The objective of this study was to assess the diagnostic values of Phadiatop Infant, an in vitro test for graded determination of immunoglobulin E (IgE) antibodies to food and inhalant allergens. One-hundred and forty-nine children (median age 1.4 yr) with symptoms of wheezing (51%) eczema (28%) or a combination of both (21%) were classified as atopic or non-atopic based on case history, atopic history, physical examination and determination of IgE antibodies. The clinical performance of Phadiatop Infant was evaluated for 145 children against this classification in a blinded manner to the allergist. Fifty-one children were classified as atopic of which Phadiatop Infant identified 49. Ninety-four were non-atopic of which the test identified 90. This resulted in a sensitivity of 96%, a specificity of 96%, a positive and a negative predictive value of 94% and 98%, respectively. Logistic regression showed that probability had to be assessed as atopic increased with increasing Phadiatop Infant values. These results suggest that Phadiatop Infant can be recommended as an adjunct to the clinical information in the differential diagnosis on IgE-mediated allergy in young children. The test thus provides an opportunity for early correct diagnosis and identification of subjects at risk for whom intervention may be necessary.

Patterns of quantitative food-specific IgE-antibodies and reported food hypersensitivity in 4-year-old children

BACKGROUND

Diagnosis of food hypersensitivity (FHS) is difficult and interpretation of food allergy tests is complicated.

OBJECTIVE

To investigate the probability of reported FHS in relation to levels of food-specific IgE-antibodies (AB) in a population-based setting of 4-year-old children (n = 2336).

METHODS

Information on FHS was obtained from a questionnaire and specific IgE-AB to milk, egg, fish, peanut, soy and wheat were analysed.

RESULTS

Thirty-one per cent of the children with reported FHS (n = 284) were sensitized (> or =0.35 kU(A)/l) to at least one of the tested foods compared with 11% of children without FHS (n = 2052). Furthermore, the probability of reported symptoms to milk, egg and fish increased with increasing levels of food-specific IgE-AB to the same food allergens. A similar trend was seen for peanut and wheat, but not for soy. Increasing levels of specific IgE-AB to milk or egg were also associated with an increasing risk of reported symptoms caused by other foods.

CONCLUSIONS

Quantitative measurements of IgE-AB to milk, egg and fish are useful to evaluate IgE-associated FHS in preschool children also in a population based sample. Such measurements appear to be of limited value for soy bean and wheat, in particular as a screening method.

Reported symptoms of food hypersensitivity and sensitization to common foods in 4-year-old children

AIM

To characterize reported food hypersensitivity (FHS) among young children in a birth cohort.

METHODS

At 4 years of age a parental questionnaire on FHS and allergic symptoms was evaluated. Blood was collected for analyses of IgE-antibodies to egg, milk, fish, wheat, peanut and soy. Complete questionnaire data was available for 3694 children (90%), and blood samples were obtained from 2563 children (63%).

RESULTS

FHS was reported in 11% of the children (n=397). Eczema was the most commonly reported symptom and the only symptom in half of these children. Food-related reactions from the airways, facial oedema or urticaria were reported in 198 children, and the majority of these children (75%) reported multiple symptoms. Furthermore, a combination of airway symptoms, facial oedema or urticaria together with sensitization to food suggested a more severe form of FHS. This was found in 1.6% of all children. Symptoms caused by peanut were closely associated with sensitization to peanut (p<0.001).

CONCLUSIONS

FHS in 4-year-old children with any of asthma, rhino-conjunctivitis, facial oedema or urticaria in combination is in most cases associated to sensitization to food. This phenotype of FHS is likely to represent a more severe form of FHS.

Quantification of atopy and the probability of rhinitis in preschool children: a population-based birth cohort study

BACKGROUND

Atopy quantification using IgE levels/skin test diameter (SPT-MWD) may better predict the expression of rhinitis than using atopy as a dichotomous variable.

OBJECTIVE

To investigate the association between the presence, temporal pattern and severity of rhinitis in preschool children and specific IgE levels/SPT-MWDs.

METHODS

Children were followed prospectively to age 5 years in a whole-population birth cohort study. We administered questionnaires (n = 815), skin prick tested children (n = 717) and measured specific serum IgE (n = 478) to inhalant and food allergens. Main outcomes were current rhinitis (CR) and current rhinoconjunctivitis (CRC).

RESULTS

The prevalence of CR and CRC was 26.1% and 12.1%, respectively. The risk of CR and CRC increased significantly with increasing IgE to grass, mite and cat; CRC was also associated with increasing IgE to dog and peanut. Similarly, increasing SPT-MWDs to inhalant allergens were significantly associated with CR and CRC. This association was also shown for grass within the group of atopic children. Perennial and seasonal rhinitis were associated with increasing IgE/SPT-MWD to mite and grass, respectively. Moderate/severe rhinitis was associated with increasing IgE/SPT-MWD to grass. In a multivariate analysis, increasing levels of IgE/SPT-MWD to grass were the strongest independent predictors of both CR (for IgE: OR 1.42, 95% CI 1.23-1.64, P < 0.001) and CRC (for IgE: 1.51, 1.30-1.76, P < 0.001).

CONCLUSION

The probability of CR/CRC increases with increasing specific IgE levels or SPT-MWD. With respect to allergic rhinitis, the absolute levels of specific IgE antibody or the size of SPT wheal offer more information than just the presence/absence of sensitization.