Early indoor aeroallergen exposure is not associated with development of sensitization or allergic rhinitis in high-risk children

Maternal vitamin D-related metabolome and offspring risk of asthma outcomes

BACKGROUND

Gestational vitamin D deficiency is implicated in development of respiratory diseases in offspring, but the mechanism underlying this relationship is unknown.

OBJECTIVE

We sought to study the link between gestational vitamin D exposure and childhood asthma phenotypes using maternal blood metabolomics profiling.

METHODS

Untargeted blood metabolic profiles were acquired using liquid chromatography-mass spectrometry at 1 week postpartum from 672 women in the Copenhagen Prospective Studies on Asthma in Childhood2010 (COPSAC2010) mother-child cohort and at pregnancy weeks 32 to 38 from 779 women in the Vitamin D Antenatal Asthma Reduction Trial (VDAART) mother-child cohort. In COPSAC2010, we employed multivariate models and pathway enrichment analysis to identify metabolites and pathways associated with gestational vitamin D blood levels and investigated their relationship with development of asthma phenotypes in early childhood. The findings were validated in VDAART and in cellular models.

RESULTS

In COPSAC2010, higher vitamin D blood levels at 1 week postpartum were associated with distinct maternal metabolome perturbations with significant enrichment of the sphingomyelin pathway (P < .01). This vitamin D-related maternal metabolic profile at 1 week postpartum containing 46 metabolites was associated with decreased risk of recurrent wheeze (hazard ratio [HR] = 0.92 [95% CI 0.86-0.98], P = .01) and wheeze exacerbations (HR = 0.90 [95% CI 0.84-0.97], P = .01) at ages 0 to 3 years. The same metabolic profile was similarly associated with decreased risk of asthma/wheeze at ages 0 to 3 in VDAART (odds ratio = 0.92 [95% CI 0.85-0.99], P = .04). Human bronchial epithelial cells treated with high-dose vitamin D3 showed an increased cytoplasmic sphingolipid level (P < .01).

CONCLUSIONS

This exploratory metabolomics study in 2 independent birth cohorts demonstrates that the beneficial effect of higher gestational vitamin D exposure on offspring respiratory health is characterized by specific maternal metabolic alterations during pregnancy, which involves the sphingomyelin pathway.

Molecular Mapping of Allergen Exposome among Different Atopic Phenotypes

Climate change and exposure to environmental pollutants play a key role in the onset and aggravation of allergic diseases. As different climate-dependent patterns of molecular immunoglobulin E (IgE) reactivity have been regionally described, we sought to investigate the evolving allergen exposome in distinctive allergic phenotypes and subtropical weather conditions through a Precision Allergy Molecular Diagnosis (PAMD@) model. Concurrent sensitization to several house dust mites (HDM) and storage mite molecules were broadly dominant in the investigated cohort, followed by the major cat allergen Fel d 1, and regardless of the basal allergic disease. Although a complex repertoire of allergens was recognized, a steadily increasing number of IgE binding molecules was associated with the complexity of the underlying atopic disease. Besides the highly prevalent IgE responses to major HDM allergens, Der p 21, Der p 5, and Der p 7 also showed up as serodominant molecules, especially in subjects bothered by asthma and atopic dermatitis. The accurate characterization of the external exposome at the molecular level and their putative role as clinically relevant allergens is essential to elucidate the phenotypic diversity of atopic disease in terms of personalized diagnosis and therapy.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

25 Years of translational research in the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC)

The Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) mother-child cohorts have provided a foundation of 25 years of research on the origins, prevention, and natural history of childhood asthma and related disorders. COPSAC's approach is characterized by clinical translational research with longitudinal deep phenotyping and exposure assessments from pregnancy, in combination with multi-omic data layers and embedded randomized controlled trials. One trial showed that fish oil supplementation during pregnancy prevented childhood asthma and identified pregnant women with the highest benefits from supplementation, thereby creating the potential for personalized prevention. COPSAC revealed that airway colonization with pathogenic bacteria in early life is associated with an increased risk of asthma. Further, airway bacteria were shown to be a trigger of acute asthma-like symptoms, with benefit from antibiotic treatment. COPSAC identified an immature gut microbiome in early life as a risk factor for asthma and allergy and further demonstrated that asthma can be predicted by infant lung function. At a molecular level, COPSAC has identified novel susceptibility genes, early immune deviations, and metabolomic alterations associated with childhood asthma. Thus, the COPSAC research program has enhanced our understanding of the processes causing childhood asthma and has suggested means of personalized prevention and treatment.

Effects of early life exposure to home environmental factors on childhood allergic rhinitis: Modifications by outdoor air pollution and temperature

BACKGROUND

There is growing evidence that allergic rhinitis (AR) is associated with indoor environmental factors, but their role in childhood AR during early life remains unclear.

OBJECTIVE

To investigate the association of preconceptional, prenatal, early postnatal, and current exposure to home environmental factors with childhood AR, and to further explore whether this association can be interacted by outdoor air pollution and temperature.

METHODS

A retrospective cohort study of 8689 preschool children was conducted during 2019-2020 in Changsha, China. A standard questionnaire was used to collect data on each family's health outcomes and home environments. We considered home environmental exposures during one year before conception, pregnancy, first year of life, and past year. Associations of indoor air pollution and allergens with AR were assessed by multiple logistic regression models.

RESULTS

Pre-birth exposure to indoor air pollution emitted by new furniture or redecoration and dampness related allergen derived from mold/damp stains and mold/damp clothes or bedding during 1 year before conception and pregnancy was significantly associated with increased AR, with adjusted ORs (95% CI) ranging from 1.35 (1.05-1.75) to 1.87 (1.55-2.27). Childhood AR was also significantly related with post-birth exposure to dampness related indoor allergen including mold/damp stains and mold/damp clothes or bedding in first year and past year and pollen allergen including total and nonflowing plants in past year, with a range of ORs (95% CI) from 1.20 (1.01-1.42) to 1.79 (1.42-2.27). We identified that pre-birth, particularly in utero exposure to both indoor air pollution from renovation and dampness related allergens, played a key role in AR development compared to post-birth exposures, and accumulative effect was observed with the highest risk of AR. High exposure to traffic-related air pollution (TRAP) including outdoor PM_2.5, NO₂, CO, and O₃, as well as living near traffic road not only significantly increased adverse effect of home environmental factors but also decreased protective effect of household dogs on childhood AR. Early life exposure to low temperature in pregnancy and high temperature in first year significantly increased AR risk of home environmental exposure. Sensitivity analysis indicated that some sub-groups were more susceptible to AR risk of home environmental exposure.

CONCLUSION

Our study suggests that pre-birth exposure to home environmental factors played an important role in AR development and this effect can be interacted by TRAP and temperature, which supports a hypothesis of "(pre)fetal origin of childhood AR".

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.

The majority of children sensitized before school-age develop allergic disease before adulthood: a longitudinal population-based study

BACKGROUND

Allergic sensitization increases the risk of and asthma and allergic rhinitis, but the impact of age at onset of sensitization is less studied.

OBJECTIVE

To examine the cumulative incidence of asthma and rhinitis up to age 19 years in relation to age at onset of sensitization to airborne allergens.

METHOD

All children in grade one and two (median age 8 years) in two municipalities in Northern Sweden were invited to skin prick tests and a questionnaire about allergic diseases, and 88% participated. At ages 12 and 19 years the protocol was repeated, and n=1510 individuals participated in all three examinations. Specific IgE was collected in a random sample at age 19, n=770. Onset of sensitization was defined; ≤8 years, 8-12 years, 12-19 years, and never sensitized. Adjusted Poisson regression was utilized to calculate risk ratios.

RESULTS

At age 19, those sensitized ≤8 year had the highest risk of asthma (RR 4.68 (95%CI 3.14-6.97)) and rhinitis (RR 22.3 (95%CI 13.3-37.6)), and 84% had developed either asthma or rhinitis. The combination of sensitization ≤8 year and family history of allergic diseases rendered high risks for asthma (RR 10.6 (6.71-16.7)) and rhinitis (RR 36.3 (18.9-69.7). Individuals sensitized ≤8 year showed significantly highest level of sensitization, as judged by number of positive skin tests and titers of specific IgE.

CONCLUSION

The majority of individuals with sensitization ≤8 years developed asthma or rhinitis before young adulthood. The high level of sensitization in early sensitized contribute to the high incidence of allergic airway conditions.

Component-resolved diagnostics in pet allergy: Current perspectives and future directions

Furry mammals kept as pets are important allergen sources. The prevalence of sensitization to dander from various animals appears to be increasing worldwide. Several mammalian allergens from diverse species and distinct protein families have been characterized, and some are available for component-resolved diagnostics (CRD). This review presents an overview of mammalian aeroallergens, with a focus on cat, dog, and horse allergens. The potential of CRD in fine-tuning the diagnostic workup following traditional methods based on whole- allergen extracts and allergen immunotherapy is discussed. The review highlights the clinical utility of CRD, particularly as a marker/predictor of increased asthma risk and disease severity. Finally, several perspectives of the future implications of CRD are offered in the context of furry animal allergens.

Pet ownership in pregnancy and methylation pattern in cord blood

Having pets in the house during the first years of life has been shown to protect against allergies. However, the result of different studies is heterogeneous. The aim of this study was to evaluate the methylation pattern in cord blood in relation to pet ownership during pregnancy.We investigated the methylation patterns of 96 cord blood samples, participants of the Epigenetic Hallmark of Maternal Atopy and Diet-ELMA project, born to mothers who either owned pets (n = 32) or did not own pets (n = 64) during their pregnancy. DNA from cord blood was analysed using the Infinium methylation EPIC. For statistical analysis, RnBeads software was applied.We found 113 differentially methylated sites (DMs) in the covariate-adjusted analysis (FDR p < 0.05), with small methylation differences. The top DMs were associated with genes: UBA7, THRAP3, GTDC1, PDE8A and SBK2. In the regional analysis, two promoter regions presented with significance: RN7SL621P and RNU6-211P. Cis-regulatory element analysis revealed significant associations with several immune-related pathways, such as regulation of IL18, Toll signalling, IL6 and complement.We conclude that pet exposure during pregnancy causes subtle but significant changes in methylation patterns in cord blood, which are reflected in the biological processes governing both innate and adaptive immune responses.

Epigenetic landscape links upper airway microbiota in infancy with allergic rhinitis at 6 years of age

BACKGROUND

The upper airways present a barrier to inhaled allergens and microbes, which alter immune responses and subsequent risk for diseases, such as allergic rhinitis (AR).

OBJECTIVE

We tested the hypothesis that early-life microbial exposures leave a lasting signature in DNA methylation that ultimately influences the development of AR in children.

METHODS

We studied upper airway microbiota at 1 week, 1 month, and 3 months of life, and measured DNA methylation and gene expression profiles in upper airway mucosal cells and assessed AR at age 6 years in children in the Copenhagen Prospective Studies on Asthma in Childhood birth cohort.

RESULTS

We identified 956 AR-associated differentially methylated CpGs in upper airway mucosal cells at age 6 years, 792 of which formed 3 modules of correlated differentially methylated CpGs. The eigenvector of 1 module was correlated with the expression of genes enriched for lysosome and bacterial invasion of epithelial cell pathways. Early-life microbial diversity was lower at 1 week (richness P = .0079) in children with AR at age 6 years, and reduced diversity at 1 week was also correlated with the same module's eigenvector (ρ = -0.25; P = 3.3 × 10-5). We show that the effect of microbiota richness at 1 week on risk for AR at age 6 years was mediated in part by the epigenetic signature of this module.

CONCLUSIONS

Our results suggest that upper airway microbial composition in infancy contributes to the development of AR during childhood, and this trajectory is mediated, at least in part, through altered DNA methylation patterns in upper airway mucosal cells.

A butterfly flaps its wings: Extinction of biological experience and the origins of allergy

OBJECTIVE

To explore links between biodiversity on all scales and allergic disease as a measure of immune dysregulation.

DATA SOURCES

PubMed and Web of Science were searched using the keywords biodiversity, nature relatedness, allergic disease, microbiome, noncommunicable diseases, coronavirus disease 2019, and associated terms.

STUDY SELECTIONS

Studies were selected based on relevance to human health and biodiversity.

RESULTS

Contact with natural environments enriches the human microbiome, promotes regulated immune responses, and protects against allergy and both acute and chronic inflammatory disorders. These important links to ecopsychological constructs of the extinction of experience, which indicates that loss of direct, personal contact with biodiversity (wildlife and the more visible elements of the natural world), might lead to emotional apathy and irresponsible behaviors toward the environment.

CONCLUSION

The immune system is a useful early barometer of environmental effects and, by means of the microbiome, is a measure of the way in which our current experiences differ from our ancestral past. Although we would benefit from further research, efforts to increase direct, personal contact with biodiversity have clear benefits for multiple aspects of physical and mental health, the skin and gut microbiome, immune function, food choices, sleep, and physical activity and promote environmental responsibility.

IL-33 is associated with allergy in children sensitized to the cat

BACKGROUND

Several studies suggest that early-life exposure to animal allergens constitutes a relevant risk factor for the development of allergic sensitization.

OBJECTIVES

The aim of the present study was to determine the role of interleukin-33 in children sensitive to cat allergen with allergic rhinitis and/or asthma.

METHODS

The study included 51 children aged 5-18 years, both sexes, allergic to cats. Sensitization to cat allergen was confirmed by skin prick tests or specific IgE. Children were evaluated for the presence of bronchial asthma, atopic dermatitis, allergic rhinitis. A questionnaire evaluating the occurrence of allergic symptoms in children after contact with the cat and dog was performed. Mothers completed a questionnaire regarding cat exposure: during pregnancy and having a cat at home. A blood sample was taken from all children to measure the level of IL-33 in the serum.

RESULTS

Keeping a cat in the home, once in the past, or having a cat in the home during the mother's pregnancy, revealed a statistically significant relationship with IL-33 levels in the studied patients. Also, daily contact with a cat during pregnancy affected the level of IL-33. Higher levels of IL-33 were shown in people with hypersensitivity to cat and pollen allergens and cat and other animals. In patients with bronchial asthma higher levels of IL-33 were found than in patients without bronchial asthma.

CONCLUSIONS

Increased serum levels of IL-33 is related with keeping cats during pregnancy and in early childhood and can be associated with the development of asthma in children.

Early Life Domestic Pet Ownership, and the Risk of Pet Sensitization and Atopic Dermatitis in Preschool Children: A Prospective Birth Cohort in Shanghai

Background: Although domestic pet ownership is on the rise, the impact of early life pet ownership on children's pet sensitization and atopic dermatitis (AD) remains controversial. Methods: Shanghai Allergy Cohort is an ongoing prospective study followed up to the age of 5 years. Pregnant mothers were recruited and their offspring were followed up every year by a group of pediatricians. Information on furred pet ownership was collected by the questionnaire. AD was diagnosed by dermatologists according to disease history and Williams criteria at 5 years ± 1 months. Skin prick test (SPT) was performed to determine sensitization to specific allergens. Multiple logistic regression models were used to evaluate the associations between pet ownership and AD, dog/cat sensitization. Results: In the 538 children at preschool age, 112 (20.82%) were diagnosed with AD. Dermatophagoides pteronyssinus and Dermatophagoides farina were the most common allergens, and almost 10% of children were positive to dog and cat. The percentage of positive SPT reactors at 5-year old was 65.28% in the group of children with AD, higher than that in non-AD group (44.57%). Domestic pet ownership at both infant and preschool period was positively associated with an increased risk of sensitization to dog (OR _adjusted = 2.85 [95% CI: 1.08-7.50 for infant exposure], OR _adjusted = 2.73 [95% CI: 1.33-5.61] for preschool exposure), and interestingly, pet ownership at infant period negatively associated with higher risk of AD at 5-year old (OR adjusted = 0.33 [95% CI: 0.12-0.88]). Conclusion: This is the first prospective birth cohort study in Shanghai that found half of preschool children had positive allergen sensitization even in the non-AD children. Although early life exposure to dog may increase the risk of dog sensitization, it significantly decreased the risk of AD. The underlying mechanisms warrant further investigations.

Cat and dog ownership during/after the first year of life and risk for sensitization and reported allergy symptoms at age 13

BACKGROUND

Avoidance of pets as a strategy for preventing atopic diseases has been questioned. This study aimed to identify the risk of sensitization and allergic symptoms at age 13 in relation to dog- and cat-keeping during and after the first year of life.

METHODS

The study included all children born at Östersund Hospital in Northern Sweden between February 1996 and January 1997 (n = 1231). At inclusion, parents were asked to answer questionnaires about lifestyle, including cat- and dog-keeping. Dog allergy, cat allergy, hay fever, and asthma were diagnosed based on parental reported allergic symptoms at 13 years of age (n = 834). The risks of sensitization or allergy in relation to dog- and cat-keeping during and after the first year of life were analyzed with logistic regression. To adjust for reverse causation, all subjects that had reported avoidance of pets due to allergic symptoms of the child or allergy in the family (n = 177) were excluded.

RESULTS

Dog- or cat-keeping during the first year of life reduced the risk of sensitization to dog or cat allergens, respectively, and to birch and to at least one of the 10 allergens tested. Cat-keeping, both during and after the first year of life, reduced the risk of cat allergy and hay fever. Having a dog at home during the first year of life reduced the risk of dog and cat allergy, whereas dog-keeping after the first year of life did not affect allergic symptoms.

CONCLUSIONS

Cat ownership, either during or after the first year of life, may be a strategy for preventing the development of cat allergy and hay fever later in life. Dog ownership reduced the risk of sensitization to dog and birch allergen, and also the risk of cat and dog allergy, but had no effect on hay fever.

Early-Life Environmental Factors, IFN-γ Methylation Patterns, and Childhood Allergic Rhinitis

<b><i>Background:</i></b> While early-life risk factors are known to influence the risk of allergies, the biological mechanisms underlying this observation are unclear. The aim of this study was to examine whether DNA methylation in childhood could underlie the association between early-life risk factors and allergic rhinitis (AR). <b><i>Methods:</i></b> In total, 234 patients, aged 6 years, were recruited, i.e., 114 were patients with AR (AR group) and 120 healthy children without AR (NAR group). The DNA methylation patterns of the <i>IFN-γ</i> promoter regions in CD4+ cells were analyzed using bisulfite sequencing. The percentage of Th1 was investigated by flow cytometry. The relationship among DNA methylation, early-life environment, and AR was examined. <b><i>Results:</i></b> After adjusting for several likely confounders, there was a higher likelihood of AR in children who had mothers with allergies than in children who had nonallergic mothers (OR = 5.19; 95% CI 1.18–29.41), in children who were born in autumn or winter than in children who were born in the summer or spring (OR = 2.69; 95% CI 1.34–5.40), and in children who lived with indoor carpet or wallpaper than in children who lived without indoor carpet or wallpaper (OR = 4.14; 95% CI 2.05–8.30). Compared to the NAR group, the AR group had higher mean methylation levels of the promoter region in <i>IFN-γY</i>, and lower numbers of IFN-γ+CD4+ cells were associated with autumn-winter birthdates. The season of birth had an indirect effect on AR at 6 years, which was mediated by the mean <i>IFN-γ</i> promoter methylation level. <b><i>Conclusions:</i></b> This study suggests that early-life environments affect AR, and this is supported by the finding of <i>IFN-γY</i> methylation as a mediator of the effect of an individual’s season of birth on AR.

Parental and child factors associated with inhalant and food allergy in a population-based prospective cohort study: the Generation R Study

The prevalence of allergic diseases in children is markedly increasing to epidemic proportions. The aim of this study is to describe the presence and examine associated parental and child characteristics of allergic sensitization and physician-diagnosed allergy in Dutch children at age 10 years. This study among 5471 children was performed in a population-based prospective cohort from fetal life onwards. Allergic sensitization was measured by skin prick tests. Physician-diagnosed allergy and parental and child characteristics were collected by questionnaires. In children aged 10 years, inhalant and food allergic sensitization was present in 32.2% and 7.1%, and physician-diagnosed inhalant and food allergy in 12.4% and 2.3%. Maternal and paternal history of allergy, eczema or asthma was associated with increased risks of physician-diagnosed inhalant allergy (aOR (95% CI) 1.44 (1.23-1.70) and 1.59 (1.30-1.94), respectively), but not with food allergy. Asthma and eczema ever at age 10 years were associated with increased risks of physician-diagnosed inhalant allergy (4.60 (3.55-5.96) and 2.42 (1.94-3.03), respectively). Eczema ever at age 10 years was associated with an increased risk of physician-diagnosed food allergy (5.78, 3.04-9.52), with the highest risk of cashew (7.36, 3.20-16.94) and peanut (5.58, 3.08-10.10) food allergy.Conclusions: We found strong effects of parental history of allergy, eczema or asthma on the presence of physician-diagnosed inhalant allergy in children at age 10 years. Eczema ever at age 10 years was a strong risk factor for the development of physician-diagnosed inhalant and food allergy. What is Known: • The prevalence of allergic diseases in children has markedly increased. • Early-life influences are critically important in the development of allergic diseases. What is New: • Maternal and paternal history of allergy, eczema or asthma is associated with increased risks of physician-diagnosed inhalant allergy but not with food allergy. • Eczema ever at age 10 years is associated with an increased risk of physician-diagnosed food allergy, with the highest risk for cashew and peanut food allergy.

Early Intervention is Important to Prevent Sensitization to New Allergens

We review current management for allergic rhinitis and possible new treatments for this condition. Management of allergic rhinitis includes promotion of protective factors, avoidance of allergens, and possibly immunotherapy. In recent years, the incidence of allergic rhinitis has increased in many countries. Early intervention at different stages is an important part of management. Allergic disease in infants has been described as the allergic march, commencing with atopic dermatitis accompanied by infantile asthma and progressing to perennial allergic rhinitis induced by house dust mite allergy. In order to prevent polysensitization, allergen-specific immunotherapy should probably be initiated at an earlier age, especially in children with rhinitis who show monosensitization to house dust mite antigens.

Indoor allergen levels in settled airborne dust are higher in day-care centers than at home

BACKGROUND

Early-life sensitization to indoor allergens predicts asthma development. The aim of this study was to compare allergen concentrations in day-care centers (DCC) with those in private homes.

METHODS

Settled airborne dust was collected 4 times a year from 20 German DCC (620 samples) and from the homes of children and day-care workers (602 samples) using electrostatic dust collectors (EDC). The samples were analyzed with fluorescence enzyme immunoassays recognizing domestic mite allergens (DM), Fel d 1, Can f 1, and Mus m 1. Pet allergen thresholds that discriminate samples from homes with cats or dogs from those without were calculated using receiver-operating characteristics. Influences on allergen levels were analyzed using multilevel models.

RESULTS

Allergen loads were on average higher in DCC than in homes. In DCC, 96% of the samples were positive for DM, 95% for Can f 1, 90% for Fel d 1, and 83% for Mus m 1. In homes, 84% contained DM, 48.5% Can f 1, 33% Fel d 1, and 43% Mus m 1. The threshold level for homes with dogs was 75 ng/m² Can f 1 (96.8% sensitivity, 96% specificity), and the threshold level for homes with cats was 46 ng/m² Fel d 1 (92% sensitivity, 94.9% specificity). In DCC, Can f 1 and Fel d 1 loads were higher than these thresholds in 37% and 54% of the samples, respectively. Allergen levels were significantly influenced by the season and room type; however, carpets on floors had no influence.

CONCLUSIONS

Mite, mouse, cat, and dog allergens were mostly higher in DCC than in homes. Exposure to dog and cat allergens in DCC often reached levels of households with pets.

Immunotherapy for pet allergies

Allergic diseases compose a serious challenge for modern societies. Their individual, medical and economical burden is large. As humans spend most of their time indoors, exposure to indoor allergens is a significant contributor to the development of allergic sensitization and respiratory allergies, such as allergic rhinoconjunctivitis and asthma. One important source of indoor allergens are pets, in particular cats and dogs. Allergens from these and other mammals spread effectively and they are encountered widely in public places. If patient education, allergen avoidance and pharmacotherapy do not suffice for controlling the symptoms of pet allergy, allergen immunotherapy can be a treatment option. Current information on allergen immunotherapy in pet allergy suggests that it can be effective in reducing allergic symptoms. However, the low number of high-quality randomized controlled trials of allergen immunotherapy in pet allergy warrants for further investigations.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Prediction and prevention of allergy and asthma in EAACI journals (2016)

The European Academy of Allergy and Clinical Immunology (EAACI) owns three journals: Allergy, Pediatric Allergy and Immunology and Clinical and Translational Allergy. One of the major goals of EAACI is to support health promotion in which prevention of allergy and asthma plays a critical role and to disseminate the knowledge of allergy to all stakeholders including the EAACI junior members.

Allergic respiratory disease: Different allergens, different symptoms

BACKGROUND

Spanish population is rather homogeneous in its genetic and sociocultural characteristics, but allergen sensitization shows wide geographical variations. We aimed at assessing whether sensitization to different allergens in the diverse geographical areas induced different clinical and quality-of-life characteristics in adult patients with a first-time diagnosis of rhinitis and/or asthma.

METHODS

Two sequential, identically designed studies were carried out to evaluate such associations (PERFILAR I and II). PERFILAR II was an extension of PERFILAR I with additional allergens being included. Both phases were epidemiological, descriptive, cross-sectional, nonintervention multicenter studies. Participants were required to have lived for at least the last 2 years in the geographical zone. Asthma control assessment was based on ACQ-5. Health-related quality of life was evaluated with validated scales for rhinitis (ESPRINT-15) and asthma (Mini-AQLQ). Skin prick tests were used to identify sensitization to involved allergens.

RESULTS

A total of 301 physicians recruited 2711 patients for PERFILAR I+II. Sensitization to allergens was significantly different in patients with rhinitis with/without asthma. Seasonal allergens were associated with rhinitis, a longer time to asthma development, and more severe and commonly intermittent rhinitis. HDM were associated with more common rhinitis, and Alternaria was associated with asthma. The study confirms an association of geographical areas with relevant allergens and allergic clinical picture.

CONCLUSION

Different types of aeroallergens and specific sensitization profiles are associated with different allergic clinical pictures (rhinitis with/without asthma), different clinical symptoms, and different levels of severity. This could have implications to predict later clinical course and to select appropriate management approaches.

Association of atopy phenotypes with new development of asthma and bronchial hyperresponsiveness in school-aged children

BACKGROUND

Although previous studies have investigated the association between atopy phenotypes and allergic diseases, atopy characterizations in association with the development of allergic diseases remain poorly understood.

OBJECTIVE

To identify atopy phenotypes in school-age children and to evaluate the association between atopy phenotypes and allergic diseases.

METHODS

We enrolled 616 children with atopy defined as 1 or more positive allergen responses on skin prick tests and 665 children without atopy from the Children's Health and Environmental Research (CHEER) study. All children were followed up for 4 years at 2-year intervals. Atopy phenotypes were classified using latent class analysis.

RESULTS

Four atopy phenotypes were characterized: later sensitization to indoor allergens (cluster 1); multiple early sensitization (cluster 2); early sensitization to outdoor allergens, especially Alternaria, and later sensitization to indoor allergens, including Aspergillus (cluster 3); and early sensitization to indoor allergens and later sensitization to outdoor allergens (cluster 4). New cases of asthma during follow-up were increased in clusters 2 and 3 (adjusted odds ratio [aOR], 2.76 and 4.25, respectively). The risk of new-onset bronchial hyperresponsiveness was highest in cluster 3 (aOR, 5.03). Clusters 2 and 4 had an increased risk of allergic rhinitis (aOR, 7.21 and 2.37, respectively).

CONCLUSION

Identification of atopy phenotypes facilitates prediction of the development of asthma and bronchial hyperresponsiveness in school-age children. Our study suggests prevention of additional sensitization is required to modify the progression of allergic diseases.

Exposure to Indoor Allergens in Different Residential Settings and Its Influence on IgE Sensitization in a Geographically Confined Austrian Cohort

BACKGROUND

Exposure to indoor allergens is crucial for IgE sensitization and development of allergic symptoms. Residential settings influence the allergen amount in house dust and hence allergic sensitization. Within this study, we investigated allergen exposure and molecule-based IgE levels in a geographically confined region and evaluated the impact of housing, pets and cleaning.

METHODS

501 adolescents from Salzburg, Austria participated in this cross-sectional study. House dust samples were examined regarding major mite, cat, dog, and mold allergens using a multiplex assay. Serum samples of participants were analyzed for specific IgE to Der p 1, Der p 2, Fel d 1, Can f 1 and Alt a 1 using the multiplex array ImmunoCAP ISAC. Information on allergies, living areas, dwelling form (house, flat, farm), pets, and household cleanliness were obtained by a questionnaire.

RESULTS

In investigated house dust samples, the concentration of cat allergen was highest while the prevalence of mold allergens was very low. Participants showed IgE sensitization to Der p 1 (13.2%), Der p 2 (18.2%), Fel d 1 (14.4%), Can f 1 (2.4%) and Alt a 1 (2.0%). In alpine regions, lower mite allergen concentrations were detected which correlated with reduced IgE levels. A trend for increased sensitization prevalence from rural to alpine to urban regions was noted. Living on farms resulted in lower sensitization prevalence to mite and cat allergens, even though exposure to mites was significantly elevated. The presence of cats was associated with a lower sensitization rate and IgE levels to cat and mite allergens, and less frequent allergic diseases. Cleaning did not impact allergen concentrations, while IgE reactivity to mites and allergic diseases were more pronounced when living in cleaner homes.

CONCLUSION

Allergen exposure to indoor allergens was influenced by setting of homes. Living in a farm environment and having a cat at home showed a protective effect for IgE sensitization and allergies. This cross-sectional study in combination with hereditary and lifestyle factors enables development of risk schemes for a more efficient management and potential prevention of allergic diseases.