Do early-life allergic sensitization and respiratory infection interact to increase asthma risk?

OBJECTIVE

The 'two-hit' hypothesis theorizes that early life allergic sensitization and respiratory infection interact to increase asthma risk.

METHODS

We sought to determine in a high allergy risk birth cohort whether interactions between early life allergic sensitization and respiratory infection were associated with increased risk for asthma at ages 6-7 years and 18 years. Allergic sensitization was assessed at 6, 12, and 24 months by skin prick testing to 3 food and 3 aeroallergens. Respiratory infection was defined as reported "cough, rattle, or wheeze" and assessed 4-weekly for 15 months, at 18 months, and age 2 years. Regression analysis was undertaken with parent-reported asthma at age 6-7 years and doctor diagnosed asthma at 18 years as distinct outcomes. Interactions between allergic sensitization and respiratory infection were explored with adjustment made for potential confounders.

RESULTS

Odds of asthma were higher in sensitized compared to nonsensitized children at age 6-7 years (OR = 14.46; 95% CI 3.99-52.4), There was no evidence for interactions between allergic sensitization and early life respiratory infection, with a greater frequency of respiratory infection up to 2 years of age associated with increased odds for asthma at age 6-7 years in both sensitized (OR = 1.13; 95% CI 1.02-1.25, n = 199) and nonsensitized children (OR = 1.31; 1.11-1.53, n = 211) (p interaction = 0.089). At age 18 years, these associations were weaker.

CONCLUSIONS

Our findings do not support 'two-hit' interactions between early life allergic sensitization and respiratory infection on asthma risk. Both early life respiratory infections and allergic sensitization were risk factors and children with either should be monitored closely for development of asthma.

Aeroallergen sensitization patterns among patients with chronic rhinitis with or without concomitant asthma

OBJECTIVES

The aim of this study was to explore the differences in the pattern of allergen sensitization in CR individuals without or with asthma, according to asthma severity.

METHODS

A total of 1066 adults were evaluated. Asthma and chronic⁄allergic rhinits were identified by specialists, questionnaries and skin-prick test. The phenotypic characterization was avaliable from skin-prick test to an aeroallergen extended panel, total IgE and pulmonary function. Using questionnaires and clinical evaluation, participants were classified into the groups: chronic rhinitis alone (CRA) and chronic rhinitis + asthma, the latter subdivided into CR + mild asthma (CRMA) and CR + moderate to severe asthma (CRMSA). Aerollergen sensitization was defined by a positive prick test to one or more allergens associated with nasal symptoms and/or asthma. The association between CR and asthma was evaluated by multivariable logistic regression. The evidence of effect modification of pattern of sensitization in CR on the association with asthma severity and outcomes was examined by introducing interactions terms in the logistic regression models adjusting for confounders.

RESULTS

Frequency of sensitization to aeroallergens was higher in association with asthma in comparison to CRA (CRMA 70.4%; CRMSA 65.0%; CRA 47.0%; p = 0.000). Similarly, the presence of asthma was associated to aeroallergen multiple sensitization (51.5%) (OR = 2.10, 95% CI 1.27-3.50). Additionally, the sensitization to mites, cockroaches, animal epithelium, grasses, and molds, were higher in asthma (56.8%, 24.3%, 12%, 7.13% and 10.3%, respectively). Sensitization to Alternaria alternata, Cladosporium herbarum and dog epithelium was exclusive in asthma groups. A concomitant asthma diagnosis was directly associated with a positive allergen sensitization at least one allergen (62.7%, OR = 2.45, 95% CI 1.80-3.34) and polissensitization (51.5%, OR = 2.10, 95% CI 1.27-3.50).

CONCLUSION

Asthma is associated with multiple allergen sensitization among patients with CR. Some unique profiles of aeroallergen sensitization were observed in patients with CR and asthma. Nevertheless, no difference was found in the sensitization in relation to asthma severity, which suggest atopy is not the main underlying mechanism for asthma severity among patients with CR.

LEVEL OF EVIDENCE

Level 3.

Ecto-5'-nucleotidase (CD73): an emerging role as prognostic factor in allergic sensitization

Over the years, the importance of the epithelium in the assessment of allergic sensitization and development of allergic diseases has increased. Sensitization to allergens appears to be influenced by genetic and external environmental factors. However, not all subjects exposed to environmental factors that damage epithelial cells suffer from allergic diseases. On this basis, identifying the signaling pathways that characterize the different phenotypes and endotypes of allergy is of high priority for a successful personalized therapy. Ecto-5'-nucleotidase/CD73 is a membrane-bound enzyme responsible for extracellular adenosine accumulation from AMP derived, in turn, from the hydrolysis of extracellular ATP. Current knowledge suggests that CD73 expression and enzymatic activity at epithelial barriers would be of fundamental importance to control the first defense against allergens, by preserving both physical and immunological epithelial barrier functions. Here, we highlight evidence for a crucial role of CD73 in features of allergic sensitization and the potential of this enzyme as prognostic marker and target of therapeutic intervention.

Associations of exposure to metals with total and allergen-specific IgE: An NHANES analysis (2005-2006)

BACKGROUND

Immunoglobulin E (IgE) is a diagnostic biomarker for allergic diseases. While some metal exposure has been found to be associated with allergic diseases, there are still a lot of knowledge gaps regarding the relationship between metal exposure and allergen-specific IgE antibodies, particularly in adults.

METHODS

We included a total of 1433 adult participants from the 2005-2006 National Health and Nutrition Examination Survey (NHANES), all of whom had concentrations of 10 metals (including Barium (Ba), Cadmium (Cd), Cobalt (Co), Cesium (Cs), Molybdenum (Mo), Lead (Pb), Antimony (Sb), Thallium (Tl), Tungsten (Tu), and Uranium (Ur)) in urine, as well as measurements of 19 allergen-specific IgE and total IgE antibodies. Linear regression, logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) were used to estimate associations between metals and total and allergen-specific IgE.

RESULTS

Linear regression models revealed a positive correlation between Pb and Cd levels and the total IgE levels. Furthermore, the WQS and BKMR models suggested a positive association between mixed metals and total IgE levels, with the WQS model highlighting Pb and Cd as the major contributors. Logistic regression models showed positive correlations between Pb and food sensitization, Ur and plant sensitization, negative correlations between Cs and plant sensitization, Co and dust mite and pet sensitization, Mo and dust mite and cockroach sensitization, and Tl and mold sensitization. Moreover, the BKMR results indicated a statistically significant negative correlation between mixed metals and mold sensitization.

CONCLUSION

According to the research findings, exposure to metals is associated with total and allergen-specific IgE in American adults. Further assessment of these relationships is necessary in representative populations of other countries.

Associations of allergy-related outcomes with depression in the US adults

Evidences showed the link between allergy and depression, while the relationships of depression with allergy-related outcomes is insufficient. The objective of this study is to evaluate and compare the relationship of depression with allergy-related outcomes assessed using two different outcome indicators, in a population-based study. A cross-sectional study was performed of 1094 participants in the 2005-2006 National Health and Nutrition Examination Survey (NHANES). The self-reported allergic symptoms of allergic rhinitis (AR) status and immunoglobulin E (IgE) were used to evaluate the allergy-related outcomes. The depression disorder was defined as the ≥ 10 points on the Patient Health Questionnaire-9. Logistic and linear regression models were performed to illustrate the associations of depression and allergy-related outcomes. The prevalence of AR and depression was 34.2% and 6.8%, respectively. The odds of depression were 8.6% higher in participants with AR patients compared those without AR [odds ratio (OR) = 1.739, 95% confidence interval (CI): (1.034, 2.933)], while the odds of depression in participants with allergic sensitization and without allergic sensitization were not found significant difference. Allergy is positively associated with depression disorder, and patients with allergy-related outcomes, such as AR, may be at higher risk of depression, while the IgE level was not founded to be related with depression. In the treatment of AR patients with depression symptoms, early detection and management of mental problems are of importance.

Prevalence and risk factors for allergic sensitization: 3 cross-sectional studies among schoolchildren from 1996 to 2017

Background

The prevalence of allergic sensitization and allergic diseases has increased for decades in Northern Europe, but recent studies are lacking.

Objective

We sought to study the prevalence trends of allergic sensitization, associated risk factors, and the association with asthma and allergic rhinitis (AR) among children in Northern Sweden.

Methods

Three cohorts of children aged 7 to 8 years participated in a skin prick test (SPT) with 10 airborne allergens in 1996, 2006, and 2017, with 2148, 1693, and 1762 participants tested, respectively, representing 87% to 90% of schoolchildren in the catchment communities. Adjusted Poisson regression was used to identify risk factors for allergic sensitization and the association with asthma and AR.

Results

The prevalence of any positive SPT response increased from 21% in 1996 to 30% in 2006 and remained at 30% in 2017 (P < .001). Sensitization to cat was the most common for all the years. The risk factor pattern for a positive SPT response was similar in all examinations, with positive and significant associations with a family history of allergy (risk ratio, 1.4-1.5) and negative and significant associations with having a cat at home (risk ratio, 0.7-0.8). The prevalence of physician-diagnosed asthma increased, but the association with allergic sensitization weakened. The opposite trends were found for AR-decreasing prevalence and strengthened association with allergic sensitization.

Conclusions

The prevalence of allergic sensitization increased from 1996 to 2006 but plateaued in the next decade, whereas the risk factor pattern remained stable. The diverging trends of associations between allergic sensitization and asthma and AR suggest secular trends in the clinical management of allergic diseases.

B-cell-derived IL-10 promotes allergic sensitization in asthma regulated by Bcl-3

Aeroallergen sensitization, mainly mediated by lung epithelium and dendritic cells (DCs), is integral to allergic asthma pathogenesis and progression. IL-10 has a dual role in immune responses, as it inhibits myeloid cell activation but promotes B-cell responses and epithelial cell proliferation. Here, we report a proinflammatory function of B-cell-derived IL-10 modulated by Bcl-3 in allergic asthma. Specifically, Bcl-3-/- mice showed elevated IL-10 levels and were found to be highly vulnerable to allergic asthma induced by house dust mites (HDMs). IL-10 had a positive correlation with the levels of the DC chemoattractant CCL-20 in HDM-sensitized mice and in patients with asthma and induced a selective increase in CCL-20 production by mouse lung epithelial cells. Blockade of IL-10 or IL-10 receptors during sensitization dampened both HDM-induced sensitization and asthma development. IL-10 levels peaked 4 h post sensitization with HDM and IL-10 was primarily produced by B cells under Bcl-3-Blimp-1-Bcl-6 regulation. Mice lacking B-cell-derived IL-10 displayed decreased lung epithelial CCL-20 production and diminished DC recruitment to the lungs upon HDM sensitization, thereby demonstrating resistance to HDM-induced asthma. Moreover, responses to HDM stimulation in Bcl-3-/- mice lacking B-cell-derived IL-10 were comparable to those in Bcl-3+/+ mice. The results revealed an unexpected role of B-cell-derived IL-10 in promoting allergic sensitization and demonstrated that Bcl-3 prevents HDM-induced asthma by inhibiting B-cell-derived IL-10 production. Thus, targeting the Bcl-3/IL-10 axis to inhibit allergic sensitization is a promising approach for treating allergic asthma. IL-10 is released rapidly from lung plasma cells under Bcl-3-Blimp-1-Bcl-6 regulation upon house dust mite exposure and amplifies lung epithelial cell (EC)-derived CCL-20 production and subsequent dendritic cell (DC) recruitment to promote allergic sensitization in asthma.

A dietary pattern of frequent plant-based foods intake reduced the associated risks for atopic dermatitis exacerbation: Insights from the Singapore/Malaysia cross-sectional genetics epidemiology cohort

BACKGROUND

The prevalence of atopic dermatitis (AD) has been increasing in recent years, especially in Asia. There is growing evidence to suggest the importance of dietary patterns in the development and management of AD. Here, we seek to understand how certain dietary patterns in a Singapore/Malaysia population are associated with various risks of AD development and exacerbation.

METHODS

A standardized questionnaire following the International Study of Asthma and Allergies in Childhood (ISAAC) guidelines was investigator-administered to a clinically and epidemiology well-defined allergic cohort of 13,561 young Chinese adults aged 19-22. Information on their sociodemographic, lifestyle, dietary habits, and personal and family medical atopic histories were obtained. Allergic sensitization was assessed by a skin prick test to mite allergens. Spearman's rank-order correlation was used to assess the correlation between the intake frequencies of 16 food types. Dietary patterns were identified using principal component analysis. Four corresponding dietary scores were derived to examine the association of identified dietary patterns with allergic sensitization and AD exacerbations through a multivariable logistic regression that controlled for age, gender, parental eczema, BMI, and lifestyle factors.

RESULTS

The correlation is the strongest between the intake of butter and margarine (R = 0.65). We identified four dietary patterns, "high-calorie foods", "plant-based foods", "meat and rice", and "probiotics, milk and eggs", and these accounted for 47.4% of the variance in the dietary habits among the subjects. Among these patterns, moderate-to-high intake of "plant-based foods" conferred a negative association for chronic (Adjusted odds ratio (AOR): 0.706; 95% confidence interval (CI): 0.589-0.847; p < 0.001) and moderate-to-severe AD (AOR: 0.756; 95% CI: 0.638-0.897; p < 0.01). "Meat and rice" and "probiotics, milk and eggs" were not significantly associated with AD exacerbation. While frequent adherence to "high-calorie foods" increased the associated risks for ever AD and moderate-to-severe AD, having a higher adherence to "plant-based foods" diminished the overall associated risks.

CONCLUSIONS

Frequent adherence to "plant-based foods" was associated with reduced risks for AD exacerbation in young Chinese adults from Singapore/Malaysia. This provides the initial evidence to support the association between dietary factors and AD. Further research is needed to better understand the pathomechanisms underlying diet and AD exacerbations.

High excess-free-fructose beverage consumption is not associated with prevalent allergy in US adults: a population-based analysis of NHANES 2005-2006

BACKGROUND

A strong association exists between high-excess free fructose (EFF) beverage consumption and prevalent allergy in children and adolescents; however, whether this association exists in the adult population is unclear. Therefore, this study aimed to investigate the relationship between high-EFF beverage intake and prevalent allergy.

METHODS

This cross-sectional study extracted data from the National Health and Nutrition Examination Survey 2005-2006. Adults aged ≥ 20 were eligible for inclusion, excluding those without complete information on beverage intake, allergic symptom survey, and allergen-specific immunoglobulin E test results. A total of 2077 adults were included. Univariate and multivariable logistic regression analyses determined the associations between high-EFF beverage consumption, prevalent allergic symptoms, and allergic sensitization.

RESULTS

After adjusting for confounders, there were no significant associations between high intake (vs. low) of sum of high-EFF beverage (adjusted odds ratio [aOR] = 1.10, 95% confidence interval [CI] 0.77, 1.57), apple juice (aOR = 0.95, 95% 0.55, 1.65), fruit drinks (aOR = 0.95, 95%CI 0.70, 1.29), soft drinks (aOR = 1.17, 95%CI 0.89, 1.55) and presence of allergic sensitization, or allergic symptoms. Stratified analyses also revealed no associations between high intake of high-EFF beverage in sum, presence of allergic symptoms or sensitization among individuals aged 20-39y, 40-59y, and ≥ 60y.

CONCLUSIONS

Our findings indicate no independent association between frequent intake of high-EFF beverage and increased likelihood of allergy in US adults.

Demystifying controversies in preschool wheeze

INTRODUCTION

Wheezing disorders in preschool children are common. Current treatment approaches assume all preschool wheezers are the same and will respond to a short course of oral corticosteroids (OCS) during acute attacks and subsequent maintenance inhaled corticosteroids (ICS) to prevent future attacks. But we have increasing evidence showing preschool wheezing disorders are markedly heterogeneous and the response to corticosteroids either during acute attacks or as maintenance therapy can be variable between patients and is determined by disease severity and underlying pathological phenotype.

AREAS COVERED

The aim of this review is to discuss recent evidence which will help to explain a few critical pathophysiological concepts that are often misunderstood, thus helping to demystify the controversies that often surround preschool wheezing disorders and can contribute to ineffective management.

EXPERT OPINION

Preschool wheezing disorders are distinct from school-age allergic asthma. There is little evidence to support the use of oral corticosteroids for acute attacks. A staged approach to confirm the diagnosis, and objective tests to determine the pathological phenotype of preschool wheeze is essential prior to initiating maintenance therapy to control symptoms and prevent attacks in children with recurrent preschool wheeze.

Exposure to household dust, allergens, and endotoxin and allergy-related outcomes alternation in the general U.S. population

It has been widely reported that the general population was at an increased risk of allergy diseases, which probably be related with household allergens exposure. However, the difference of local and systemic allergic reactions exposure to allergens has not been reported in the general population previously. The data of 1094 U.S. adults from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 data bank were analyzed. Dust, allergens (Bia g 1, Bia g 2, Can f 1, Feld 1, Derp 1, Mus m 1, Rat n 1, Alternaria alternate, and Aspergillus fumigatus), and endotoxin, were measured to estimate sensitizing source exposure. And allergy-related outcomes indicators including hay fever, sneezing, allergic rhinitis (AR), immunoglobulin E (IgE), and allergic sensitization, were evaluzted to estimate local and systemic allergic reactions. Multiple linear regression and logistic regression models were used to examine the associations of sensitizer and allergy-related outcomes. The mean or median concentration of dust and endotoxin were 0.66 g and 12.98 EU/mg dust. The Derp 1, Mus m 1, Rat n 1, Alternaria alternate, and Aspergillus fumigatus were the main allergens in the dust, with the concentrations of 30.66 ng/g dust, 30.73 ng/g dust, 5.94 ng/g dust, 5.20 ng/g dust, and 207.68 μg/g dust, respectively. The prevalence of AR was 34.2% among the general population. After controlling for sociodemographic factors, we found that the allergens, such as Can f 1 and Feld 1, were positively associated with AR. The prevalence of allergic sensitization was about 20%. Dust and endotoxin were found positively associated with allergic sensitization, while Bia g 2, Rat n 1, Alternaria alternate, and Aspergillus fumigatus were inversely associated with that. Dust and endotoxin probably be associated with higher risk of local allergic reactions, while some allergens, such as Bia g 2, Rat n 1, Alternaria alternate, and Aspergillus fumigatus probably be associated with lower risk of systemic allergic reactions.

Blood trihalomethane concentrations and allergic sensitization: A nationwide cross-sectional study

BACKGROUND

Exposure to disinfection by-products has been associated with several allergic diseases, but its association with allergen-specific immunoglobulin E (IgE) antibodies remains inconclusive.

METHODS

We included 932 U.S. adolescents and 2187 adults from the National Health and Nutrition Examination Survey 2005-2006 who had quantified blood THM concentrations [chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM)] and 19 allergen-specific IgE antibodies. The odds ratios (ORs) of allergen-specific sensitization per 2.7-fold increment in blood THM concentrations were estimated by multivariable logistic regression models.

RESULTS

Blood THM concentrations were unrelated to any allergen-specific sensitization in adults. Among adolescents, however, we found positive associations between blood TCM and chlorinated THMs (Cl-THMs: sum of TCM, BDCM, and DBCM) concentrations and the odds of pet sensitization [OR = 1.28 (95 % CI: 1.05, 1.55) and 1.38 (1.15, 1.65), respectively, per each 2.7-fold increment], between blood BDCM concentrations and the odds of mold [OR = 1.47 (1.24, 1.74)], plant [OR = 1.25 (1.09, 1.43)], pet [OR = 1.27 (1.07, 1.52)], and food sensitization [OR = 1.18 (1.03, 1.36)], and between blood brominated THM (Br-THMs: sum of BDCM, DBCM, and TBM) and total THM (TTHMs: sum of 4 THMs) concentrations and the odds of mold [OR = 1.52 (1.30 1.78) and 1.30 (1.03, 1.65), respectively], dust mite [OR = 1.39 (1.06, 1.82) and 1.45 (1.06, 1.98), respectively], and pet sensitization [OR = 1.42 (1.05, 1.92) and 1.54 (1.19, 1.98), respectively].

CONCLUSION

Higher blood concentrations of THMs were associated with a greater risk of allergic sensitization among U.S. adolescents but not in adults.

A narrative review on asthma and pest sensitization (cockroach, mouse and rat allergens): a social issue besides the medical problem

OBJECTIVE

Among animals defined as "pests", cockroaches and rodents (mouse and rat) represent the most common cause of airway allergic sensitization and bronchial asthma worldwide. Their frequency of sensitization has been widely assessed in US and other countries but poorly in Western Europe. This narrative review aims to provide a synthesis of data resulting in MEDLINE concerning allergic sensitization/asthma to pests as well as their related environmental/social risk factors, specifically in the European area.Data Sources: We performed a literature research in MEDLINE for clinical trials, randomized controlled trials, systematic reviews and meta-analyses.Study Selections: We selected studies to the following key words: allergic sensitization, allergic rhinitis, bronchial asthma, cockroach, hypersensitivity, integrated pest management, material hardship, medication compliance, mouse, pest, poverty, rat, rodents.

RESULTS

Current evidence indicates that residence in poor and urban areas, exposure to outdoor/indoor pollutants and tobacco smoke, poverty, material hardship, poor-quality housing, differences in health care quality, medication compliance, heath care access contribute to increased pest-related allergic sensitization and asthma morbidity.

CONCLUSION

Further research should be done on many aspects of pest allergy such as a better characterization of allergens and epidemiological aspects. Relevant social actions should be carried out against poverty, healthcare disparities, psycho-social stress, poor compliance to therapy, with economic contributions to improve private and public living environments. Allergic sensitization to pests and pest-allergic respiratory diseases like asthma are "paradoxical" conditions, as they typically affect the poorest communities but can only be corrected by high-cost (diagnostic and preventive) interventions. We hope that progress can be made in this direction in the future.

Ovalbumin-Induced Epithelial Activation Directs Monocyte-Derived Dendritic Cells to Instruct Type 2 Inflammation in T Cells Which Is Differentially Modulated by 2'-Fucosyllactose and 3-Fucosyllactose

Allergic sensitization starts with epithelial cell activation driving dendritic cells (DCs) to instruct T helper 2 (Th2) cell polarization. Food allergens trigger intestinal epithelial cell (IEC) activation. Human milk oligosaccharides may temper the allergic phenotype by shaping mucosal immune responses.We investigated in vitro mucosal immune development after allergen exposure by combining ovalbumin (OVA)-preexposed IEC with monocyte-derived DCs (OVA-IEC-DCs) and subsequent coculture of OVA-IEC-DCs with Th cells. IECs were additionally preincubated with 2'FL or 3FL.OVA activation increased IEC cytokine secretion. OVA-IEC-DCs instructed both IL13 (p < 0.05) and IFNγ (p < 0.05) secretion from Th cells. 2'FL and 3FL permitted OVA-induced epithelial activation, but 2'FL-OVA-IEC-DCs boosted inflammatory and regulatory T-cell development. 3FL-OVA-IEC lowered IL12p70 and IL23 in DCs and suppressed IL13 (p < 0.005) in T cells, while enhancing IL17 (p < 0.001) and IL10 (p < 0.005).These results show that OVA drives Th2- and Th1-type immune responses via activation of IECs in this model. 2'FL and 3FL differentially affect OVA-IEC-driven immune effects. 2'FL boosted overall T-cell OVA-IEC immunity via DC enhancing inflammatory and regulatory responses. 3FL-OVA-IEC-DCs silenced IL13, shifting the balance towards IL17 and IL10.This model demonstrates the contribution of IEC to OVA Th2-type immunity. 2'FL and 3FL modulate the OVA-induced activation in this novel model to study allergic sensitization.

Allergic sensitization and exposure to ambient air pollution beginning early in life lead to a COPD-like phenotype in young adult mice

The perinatal period and early infancy are considered critical periods for lung development. During this period, adversities such as environmental exposures, allergic sensitization, and asthma are believed to impact lung health in adulthood. Therefore, we hypothesized that concomitant exposure to allergic sensitization and urban-derived fine particulate matter (PM_2.5) in the early postnatal period of mice would cause more profound alterations in lung alveolarization and growth and differently modulate lung inflammation and gene expression than either insult alone in adult life. BALB/c mice were sensitized with ovalbumin (OVA) and exposed to PM_2.5 from the fifth day of life. Then, we assessed lung responsiveness, inflammation in BALF, lung tissue, and alveolarization by stereology. In addition, we performed a transcriptomic analysis of lung tissue on the 40th day of life. Our results showed that young adult mice submitted to allergic sensitization and exposure to ambient PM_2.5 since early life presented decreased lung growth with impaired alveolarization, a mixed neutrophilic-eosinophilic pattern of lung inflammation, increased airway responsiveness, and increased expression of genes linked to neutrophil recruitment when compared to animals that were OVA-sensitized or PM_2.5 exposed only. Both, early life allergic sensitization and PM_2.5 exposure, induced inflammation and impaired lung growth, but concomitant exposure was associated with worsened inflammation parameters and caused alveolar enlargement. Our experimental data provide pathological support for the hypothesis that allergic or environmental insults in early life have permanent adverse consequences for lung growth. In addition, combined insults were associated with the development of a COPD-like phenotype in young adult mice. Together with our data, current evidence points to the urgent need for healthier environments with fewer childhood disadvantage factors during the critical windows of lung development and growth.

Evaluation of Skin Prick Test Reading Time at 10 versus 15 min in Young Infants

Introduction

The optimal time point for reading the mean wheal diameter (MWD) of a skin prick test (SPT) in infants is not established. We aimed to assess if either of two reading time points of the SPT, 10 or 15 min, was superior to detect allergic sensitization (AS) in 6-month-old infants.

Methods

In 1,431 6-month-old infants from the population-based Preventing Atopic Dermatitis and ALLergies in children (PreventADALL) mother-child cohort, the SPT was performed with standard solutions for egg, cow's milk, peanut, wheat, soy, birch, timothy, dog, and cat. The MWD was measured after 10 and 15 min. AS was defined as a positive SPT with MWD ≥2 mm larger than the negative control.

Results

Overall, 149 (10.4%) infants were sensitized to at least one allergen at 10 and/or 15 min, while 138 (9.6%) had a positive SPT at 10 min and 141 (9.9%) at 15 min. A total of 12,873 allergen pricks were performed with 212 (1.6%) being positive at any time point, 194 (1.5%) positive at 10 min, and 196 (1.5%) positive at 15 min. The mean (95% CI) histamine MWD of 3.8 (3.8, 3.9) mm at 10 min was significantly larger than the 3.6 (3.6, 3.7) mm at 15 min.

Discussion/Conclusions

Reading the SPT after both 10 and 15 min increased the number of 6-month-old infants with documented AS compared to reading after one time point only. As neither 10 nor 15 min reading time was superior to the other in detecting AS, our results indicate that readings at both time points should be considered. However, the histamine MWD was significantly larger at 10 min compared to 15 min. Reappraisal of SPT reading in infancy may be warranted.

Development of Sensitization to Multiple Allergen Molecules from Preschool to School Age Is Related to Asthma

INTRODUCTION

Allergic sensitization in early life has been identified as a strong risk factor for subsequent asthma in childhood. It is still unclear why only a part of sensitized children develop asthma, and the role of specific allergen molecules in asthma pathogenesis is ambiguous [Pharmacol Ther. 2009 Feb;121(2):174-84]. We assessed the sensitization to multiple allergen molecules longitudinally and explored its relation to persistent asthma at 7 years.

METHODS

Seventy-two children included during an acute wheezing episode (cases) were followed prospectively from early preschool age (EPA) to age 7, and compared to 43 healthy controls at EPA. Allergen molecules were analyzed at EPA and age 7 using ImmunoCAP Solid-phase Allergen Chip (ISAC). Asthma diagnosis at 7 years was based on symptoms, medication, and spirometry.

RESULTS

At EPA, cases compared to controls showed a tendency toward having a higher prevalence of allergic sensitization (23.6% vs. 9.3%, p = 0.055). The prevalence of sensitization increased in cases from EPA to 7 years (23.6% vs. 38.9%; p = 0.048) as well as the median number (range) of immunoglobulin E (IgE)-reactive molecules 3 (3-14) versus 6.5 (1-21); p = 0.024. Sensitization to each additional molecule from EPA to the age of 7 was significantly related to asthma at 7 (OR = 1.25, 95% confidence interval [1.01, 1.54]).

CONCLUSION

Polysensitization, assessed by allergen molecules, had a significant impact on persistent asthma at school age. The extent of sensitization, illustrated by molecular spreading from preschool to school age, was related to asthma diagnosis at 7 years in children with a history of wheezing at early life.

Longitudinal changes in body mass index Z-scores during infancy and risk of childhood allergies

BACKGROUND

Few studies address the dynamic changes of body mass index (BMI) Z-scores during infancy with breastfeeding and their impact on childhood atopic diseases.

METHODS

A total of 183 children from a birth cohort regularly followed-up for 4 years were enrolled in this study. Time series data of BMI Z-scores from 1 month to 2 years of age was clustered using K-means method in R software. Breastfeeding status during the first 6 months of life was recorded and classified. The total serum and specific immunoglobulin E (IgE) levels to food and inhalant allergens were measured at age 0.5, 1, 1.5, and 2 years.

RESULTS

Using K-means clustering, the dynamic changes in BMI Z-scores were classified into three clusters (cluster A, increasing, n = 62; cluster B; decreasing, n = 62; cluster C, constant low, n = 59). Despite having no statistical association with atopic diseases, a decreasing trend in infantile BMI Z-scores was significantly associated with a higher prevalence of IgE sensitization at age 1 which increased the risk of rhinitis development at age 4 (P = 0.007). No difference in BMI Z-scores was determined between different breastfeeding patterns. However, exclusive formula feeding ≥6 months was found to be significantly associated with mite sensitization at age 1.5 years which risks asthma development at age 4 (P = 0.001).

CONCLUSIONS

A decreasing trend of BMI Z-scores during infancy is determined to be inversely associated with IgE and allergen sensitization, which may potentially increase the risk of allergies in early childhood.

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.

Indoor Environmental Factors May Modify the Response to Mouse Allergen Reduction Among Mouse-Sensitized and Exposed Children with Persistent Asthma

BACKGROUND

Whether concomitant home exposures modify the effectiveness of mouse allergen reduction among mouse-sensitized children with asthma is unknown.

OBJECTIVE

To determine whether a lower baseline home mouse allergen level, lower particulate matter 10 μ or less (PM₁₀), and the absence of sensitization and exposure to other indoor allergens are associated with greater improvements in asthma associated with mouse allergen reduction.

METHODS

A secondary analysis of a randomized clinical trial of a home mouse allergen intervention was performed to examine the effect of 3 indoor factors on the relationship between mouse allergen reduction and a range of asthma outcomes.

RESULTS

Participants (N = 297) were predominantly minority (78% African American, 22% Hispanic) and publicly insured (88%). Higher baseline mouse allergen levels were associated with a greater response to mouse allergen reduction for several symptom and exacerbation outcomes. Lower indoor PM₁₀ levels were associated with a greater response to mouse allergen reduction for several symptom outcomes, but not exacerbation outcomes. Overall, sensitization and exposure to other indoor allergens did not appear to modify the effect of mouse allergen reduction.

CONCLUSIONS

In this population of predominantly low-income children with persistent asthma and mouse sensitization, mouse allergen reduction was associated with improvements in asthma, especially among those with high baseline mouse allergen exposure. Lower indoor PM₁₀ was associated with greater improvements in asthma symptoms.

Allergic sensitization profiles among the foreign-born population in the north of Madrid

Summary

Background. We assessed differences in allergic sensitization and clinical characteristics in a foreign-born population. Methods. Prospective, observational, descriptive study of patients aged > 12 years who were seen at the Department of Allergy, La Paz Hospital (Madrid, Spain), between January 2017 and December 2018. Patients were classified by geographical origin and ethnicity. Results. We included 150 patients (110 female) with a mean age of 38.38 years. Mean time to onset of respiratory symptoms after immigration was 8.47 years. Significant differences were observed between ethnic groups (p = 0.007). The most frequent sensitization was to grass pollen (75.2%), which was more common in South American patients (p = 0.005). We found that 59% of patients were sensitized to Cupressus and Olea pollen (higher in Asian patients, p = 0.032 and p = 0.049). Conclusions. Allergic sensitization in the foreign-born population was similar to that of the autochthonous population although differences between the groups were identified.

The triad of current asthma, rhinitis and eczema is uncommon among adults: Prevalence, sensitization profiles, and risk factors

BACKGROUND

Coexistence of asthma, rhinitis, and eczema has been studied in children, but data are lacking in adults. As new treatments emerge, epidemiological data on the coexistence are needed.

AIMS

To study the prevalence of concomitant asthma, rhinitis and eczema in the general adult population and among those sensitized to aeroallergens, and to study associations between background characteristics and risks of phenotypes of asthma, rhinitis, and eczema.

METHODS

In the West Sweden Asthma Study, phenotypes and sensitization profiles of 1103 randomly selected adults (16-75 years) were assessed. The methods included measures of serum-IgE and structured interviews on asthma, rhinitis, eczema, their associated symptoms, and relevant risk factors.

RESULTS

Among all participants and in those sensitized, 2% and 6% had concomitant asthma, rhinitis, and eczema, respectively, and the condition did not differ by age or sex. Corresponding figures for asthma and rhinitis, but not eczema, was 8% and 19%, respectively. Determinants of coexistence of the three conditions were family history of asthma/allergy, body mass index, and occupational exposure to gas, dust and fumes. Allergic sensitization in those with asthma, rhinitis and eczema was found in 78%, in those with asthma and rhinitis but not eczema in 65%, in those with asthma and eczema but not rhinitis in 40%, while only 5% were sensitized among those having asthma only.

CONCLUSIONS

In the general adult population about 2% have concomitant asthma, rhinitis, and eczema. Of sensitized adults, about 6% has coexistence of the three conditions.

Effect of individual allergen sensitization on omalizumab treatment outcomes in patients with severe allergic asthma determined using data from the Czech Anti-IgE Registry

Background

Omalizumab is an efficient drug for patients with uncontrolled severe allergic asthma (SAA). However, little is known about the differences in omalizumab treatment outcomes among patients with different types of atopic sensitization. Here, we assessed the effect of sensitization to individual allergens or their combinations on the outcomes of anti-IgE therapy in patients with SAA.

Methods

We performed a post hoc analysis of data of subgroups of patients enrolled in the Czech Anti-IgE Registry (CAR). The patients were evaluated at baseline and 16 weeks and 12 months after omalizumab treatment initiation. We analyzed the dependence of primary treatment outcomes [global evaluation of treatment effectiveness (GETE) after 16 weeks of treatment, a reduction in severe exacerbation rate (ER), and an improvement in the asthma control test (ACT) result during 12 months of treatment] and secondary outcomes [a reduction in systemic corticosteroid (SCS) use, an improvement in lung functions, and a fraction of exhaled nitric oxide] of patients with SAA treated with omalizumab for 12 months on sensitization to different perennial aeroallergens. We assessed sensitization to house dust mites, molds, and pets at baseline using skin prick tests and/or specific IgE measurement (semiquantitative evaluation). We compared polysensitized patients (sensitized to all tested allergens) with monosensitized (single positivity) or partially polysensitized patients (combined positivity but not to all allergens).

Results

We enrolled 279 patients (58.3% women, mean age 52.9 years). Omalizumab treatment presented an 82.8% response rate (according to GETE). It significantly reduced severe asthma exacerbations and SCS use, and improved the ACT result in 161 responders. We identified a subgroup of responders with distinct sensitization patterns (polysensitization to all tested perennial allergens) with higher odds of being responders (OR = 2.217, p = 0.02) and lower tendency to improve ACT result (OR 0.398, p = 0.023) and reduce ER (OR 0.431, p = 0.034) than non-polysensitized patients.

Conclusions

The clinical benefit of sensitization for patients with SAA receiving omalizumab may be particularly dependent on sensitization pattern. Polysensitized patients showed a higher tendency to be responders (GETE), but a lower tendency to improve the ACT result and reduce ER than non-polysensitized patients.

Asthma, allergic sensitization and lung function in sickle cell disease

BACKGROUND

Pulmonary disease is a frequent acute and chronic manifestation in sickle cell disease (SCD), presenting high morbidity and mortality.

OBJECTIVES

To identify the prevalence and association of asthma, allergic sensitization and altered pulmonary function in patients with SCD (SS and Sβ^o).

METHODS

A single-center, cross-sectional study was conducted, in which 70 patients with SCD and 44 controls, aged six to 18 years, responded to the questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC), complemented with an anamnesis regarding the associated clinical outcomes. All patients underwent immediate hypersensitivity skin tests with aeroallergens and a pulmonary function evaluation (spirometry). Regarding the statistical analysis, parametric and non-parametric methods were used, depending on the variables studied. Tests were considered significant when p<0.05.

RESULTS

There was no significant difference between the patients and controls regarding the prevalence of asthma and allergic sensitization (p>0.05). The number of occurrences of acute chest syndrome per patient per year was significantly higher for asthmatic patients than for non-asthmatic patients (p=0.04). Obstructive pulmonary function occurred in 30.9% of the patients and in 5.4% of the controls, and restrictive pulmonary function occurred in 5.5% of the patients and 5.4% of the controls. Asthma and wheezing in the last 12months had significant associations with obstructive pulmonary function (p=0.014 and p=0.027, respectively).

CONCLUSIONS

The occurrence of asthma, allergic sensitization and alteration in lung function in patients with SCD reinforces the importance of routine monitoring of these diagnoses, which allows for early treatment and prevention of the evolution of pulmonary disease in adulthood.

Recent advances in mechanisms of food allergy and anaphylaxis

Food allergens are innocuous proteins that promote tolerogenic adaptive immune responses in healthy individuals yet in other individuals induce an allergic adaptive immune response characterized by the presence of antigen-specific immunoglobulin E and type-2 immune cells. The cellular and molecular processes that determine a tolerogenic versus non-tolerogenic immune response to dietary antigens are not fully elucidated. Recently, there have been advances in the identification of roles for microbial communities and anatomical sites of dietary antigen exposure and presentation that have provided new insights into the key regulatory steps in the tolerogenic versus non-tolerogenic decision-making processes. Herein, we will review and discuss recent findings in cellular and molecular processes underlying food sensitization and tolerance, immunological processes underlying severity of food-induced anaphylaxis, and insights obtained from immunotherapy trials.

Symptoms of titanium and nickel allergic sensitization in orthodontic treatment

Aim

The study aimed to evaluate to which extent self-reported symptomatology, age, and sex are predictors of titanium and nickel allergic sensitization in patients in treatment with fixed orthodontic appliances.

Methods

The study analyzed 228 subjects aged 11–45 years (median 18, interquartile range 16–22); 68% of them were females, and 52% were adolescents. The allergic sensitization testing included epicutaneous patch test to titanium, titanium dioxide, titanium oxalate, titanium nitride, and nickel sulfate. The questionnaire on symptoms potentially linked to titanium and nickel sensitization was used.

Results

Prevalence of the allergic sensitization to titanium in patients undergoing orthodontic treatment was 4% (2% only to titanium without nickel) while to nickel 14% (12% nickel without titanium). Hypersensitivity to both metals at the same time was present in 2% of subjects. Sensitization to nickel was more common in females than in males (17 vs. 8%) and much more common in adults than in adolescents with small effect size (20 vs. 8%; p = 0.013). Sensitization to titanium was more common in females than in males (6 vs. 1%) with no difference in age. Multiple logistic regression analysis revealed that adult age increases the odds for being sensitized to nickel for 2.4 × (95% CI 1.1–5.6; p = 0.044) while watery eyes for 3.7 × (95% CI 1.2–11.1; p = 0.022). None of the symptoms were significant predictors of titanium sensitization.

Conclusion

Allergic sensitization to titanium and nickel are not very frequent in orthodontic patients, and self-reported symptomatology is a weak predictor of those sensitizations.

Association between maternal age at delivery and allergic rhinitis in schoolchildren: A population-based study

Background

Some studies have shown associations of maternal age at delivery with asthma and food allergy in offspring. However, the relationship between maternal age at delivery and allergic rhinitis is largely unclear. This study aimed to investigate the association between maternal age at delivery and allergic rhinitis in a population sample of Asian children, and to explore potential effect modifiers.

Methods

A total of 1344 singleton-birth children (763 boys, 56.8%; mean age, 6.4 years) participating in the Longitudinal Investigation of Global Health in Taiwanese Schoolchildren (LIGHTS) cohort were evaluated by a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and interviewed by pediatricians. Allergic sensitization was determined by using Phadiatop Infant. Multiple logistic regression models with covariates adjustment were performed to investigate the association of maternal age at delivery with allergic rhinitis and allergic sensitization in offspring.

Results

Among 1344 study children, 793 (59%) had physician-diagnosed allergic rhinitis. Advanced maternal age at delivery (≥40 years) was significantly associated with increased odds of allergic rhinitis (adjusted odds ratio [AOR] = 4.58, 95% confidence interval [CI]: 1.90–11.03) and allergic sensitization (AOR = 2.86, 95% CI: 1.13–7.22) in offspring. A sex-stratified analysis revealed that the association of advanced maternal age with allergic rhinitis was statistically significant only in female offspring (AOR = 7.02, 95% CI: 1.89–26.14). Stratified analyses by birth order or environmental tobacco smoke exposure during pregnancy did not reveal any significant differences.

Conclusion

Advanced maternal age at delivery was associated with increased risk of allergic rhinitis in Asian children, probably more pronounced among girls.

Role of Environmental Adjuvants in Asthma Development

PURPOSE OF REVIEW

This review summarizes recent progress in our understanding how environmental adjuvants promote the development of asthma.

RECENT FINDINGS

Asthma is a heterogeneous set of lung pathologies with overlapping features. Human studies and animal models suggest that exposure to different environmental adjuvants activate distinct immune pathways, which in turn give rise to distinct forms, or endotypes, of allergic asthma. Depending on their concentrations, inhaled TLR ligands can activate either type 2 inflammation, or Th17 differentiation, along with regulatory responses that function to attenuate inflammation. By contrast, a different category of environmental adjuvants, proteases, activate distinct immune pathways and prime predominantly type 2 immune responses. Asthma is not a single disease, but rather a group of pathologies with overlapping features. Different endotypes of asthma likely arise from perturbations of distinct immunologic pathways during allergic sensitization.

Association between serum immunoglobulin E levels and knee osteoarthritis in Korean adults

OBJECTIVE

The objective of this study was to examine whether osteoarthritis (OA) in the knees was associated with total immunoglobulin E (IgE), allergen-specific IgE, or allergic sensitizations in a nationally representative population.

METHODS

The study population comprised of 785 adults aged 50 years or more in the Korea National Health and Nutrition Examination Survey 2010. OA was diagnosed as radiographic (rOA) and symptomatic osteoarthritis (sxOA). We performed multivariable logistic regression analyses to investigate relationships of OA in a knee with serum total IgE, allergen (Dermatophagoides farinae, cockroach, and dog allergens)-specific IgE, and allergic sensitizations.

RESULTS

Participants with the highest tertile of the total IgE had 92% and 242% increased risk of knee rOA and sxOA, respectively. Those with D. farinae-specific IgE had 2.2 times increased risk of knee sxOA compared to the lowest tertile. Participants with high total IgE (>150kU/L) had a 60% increased risk of knee rOA. Those with D. farinae-specific sensitization (>0.35kU/L) had 2.0 times increased risk of knee sxOA in compared to those without sensitization. Population-attributable fractions of knee rOA caused by high total IgE and knee sxOA caused by D. farinae-specific sensitization were 9.8% and 15.3%, respectively.

CONCLUSIONS

Total IgE and D. farinae-specific IgE were significantly associated with OA in knees of Korean adults. High total IgE and D. farinae-specific sensitization were also associated with their OA.

[Sensitization to aeroallergens in patients with allergic rhinitis in Aguascalientes, Mexico]

BACKGROUND

Allergic rhinitis is the most common allergic disease worldwide and it is caused by a reaction of hypersensitivity to aeroallergens. To our knowledge, there aren't any previous studies of aeroallergenic sensitization in Aguascalientes, Mexico.

OBJECTIVE

To describe the sensitization to aeroallergens in patients with allergic rhinitis who have been treated at a private clinic in Aguascalientes, Mexico.

METHODS

A descriptive, cross-sectional and retrospective study was done in which patients diagnosed with allergic rhinitis were included. Skin prick tests with 32 allergenic extracts were carried out and the frequencies at each were determined.

RESULTS

In total, 350 patients were analyzed. The most frequent aeroallergens were grass pollens (74.8%), followed by tree pollens (64.8%) and dust mites Dermatophagoides pteronyssinus (64%). The group of patients under 20 years of age was predominant (67.1%), followed by the group of 21 to 40 years old (22.5%).

CONCLUSIONS

This research provides information about regional patterns of sensitization, which shall facilitate diagnostic tests in the region and the best practices of specific immunotherapy.

Associations between serum 25-hydroxyvitamin D levels and allergic sensitization in early childhood

BACKGROUND AND OBJECTIVES

Vitamin D status may be related to allergen sensitizations, but the evidence is inconsistent. The objective of this study was to assess whether serum 25-hydroxyvitamin D (25(OH)D) levels were associated with allergic sensitizations in early childhood.

METHODS

Data were collected from 2642 children who visited the Guangdong Women and Children's Hospital from January 2016 to May 2017 for routine health check-ups. Serum 25(OH)D levels were tested by electrochemiluminescence immunoassay. Allergic sensitizations including food and inhalant allergens were tested for specific IgE antibodies at one year (12 months 0 days through 12 months 30 days) and two years (24 months 0 days through 24 months 30 days) of age.

RESULTS

The mean level of serum 25(OH)D was 86.47±27.55nmol/L, with a high prevalence of vitamin D insufficiency (<75nmol/L) in children aged 0-2 years (36.8%). Lower 25(OH)D levels with serum total IgE of more than 200IU/mL (81.54±25.53nmol/L) compared with less than 100IU/mL (87.92±28.05nmol/L). The common sensitization to allergens in children aged one and two years were milk (44.2%), cat epithelium (26.4%), egg (13.1%), dog epithelium (12.7%) and Dermatophagoides farinae (6.7%). After multivariate adjustment, data in 25(OH)D treated as a continuous variable or categories, no consistent associations were found between 25(OH)D levels and allergen-specific IgEs.

CONCLUSIONS

Serum 25(OH)D level showed an inverse relationship with total IgE level in early childhood. However, there is lack of evidence to support associations between low 25(OH)D levels and allergic sensitization to various allergens.

Atopy Modifies the Association Between Inhaled Corticosteroid Use and Lung Function Decline in Patients with Asthma

BACKGROUND

Inhaled corticosteroids (ICSs) are the mainstay of asthma treatment, but response to medication is variable. Patients with allergic inflammation generally show a better short-term response to ICSs; however, studies on predictors of long-term response are few.

OBJECTIVE

To assess whether allergic sensitization can modify the association between ICS use and lung function decline over 20 years in adult asthma.

METHODS

We used data from the 3 clinical examinations of the European Community Respiratory Health Survey. We measured ICS use (no use, and use for <1.3, 1.3-8, and >8 years) and FEV₁ decline among subjects with asthma over the 2 periods between consecutive examinations. We conducted a cohort study combining data of the 2 periods (906 observations from 745 subjects) to assess whether the association between ICS use and FEV₁ decline was modified by allergic sensitization (IgE > 0.35 kU/L for any of house-dust mite, timothy grass, cat, or Cladosporium).

RESULTS

FEV₁ decline was similar for non-ICS users, as well as ICS users for less than 1.3 years, with and without allergic sensitization. However, among subjects on ICSs for a longer period, sensitization was associated with an attenuated decline (P_interaction = .006): in the group treated for more than 8 years, FEV₁ decline was on average 27 mL/y (95% CI_{Bonferroni-adjusted}, 11-42) lower for subjects with sensitization compared with nonsensitized subjects.

CONCLUSIONS

Our study suggests that biomarkers of atopy can predict a more favorable long-term response to ICSs. Randomized controlled studies are needed to confirm these findings.

Using high-resolution residential greenspace measures in an urban environment to assess risks of allergy outcomes in children

Despite reported health benefits of urban greenspace (gs), the epidemiological evidence is less clear for allergic disease. To address a limitation of previous research, we examined the associations of medium- and high-resolution residential gs measures and tree and/or grass canopies with allergic outcomes for children enrolled in the longitudinal cincinnati childhood allergy and air pollution study (ccaaps). We estimated residential gs based on 400 m radial buffers around participant addresses (n = 478) using the normalized differential vegetation index (ndvi) and land cover-derived urban greenspace (ugs) (tree and grass coverage, combined and separate) at 30 m and 1.5-2.5 m resolution, respectively. Associations between outdoor aeroallergen sensitization and allergic rhinitis at age 7 and residential gs measures at different exposure windows were examined using multivariable logistic regression models. A 10% increase in ugs-derived grass coverage was associated with an increased risk of sensitization to grass pollens (adjusted odds ratio [aor]: 1.27; 95% confidence interval = 1.02-1.58). For each 10% increase in ugs-derived tree canopy coverage, nonstatistically significant decreased odds were found for grass pollen sensitization, tree pollen sensitization, and sensitization to either (aor range = 0.87-0.94). Results similar in magnitude to ugs-tree canopy coverage were detected for ndvi and allergic sensitizations. High-resolution (down to 1.5 m) gs measures of grass- and tree-covered areas showed associations in opposite directions for different allergy outcomes. These data suggest that measures strongly correlated with tree canopy (e.g., ndvi) may be insufficient to detect health effects associated with proximity to different types of vegetation or help elucidate mechanisms related to specific gs exposure pathways.

Fish-derived low molecular weight components modify bronchial epithelial barrier properties and release of pro-inflammatory cytokines

The prevalence of fish allergy among fish-processing workers is higher than in the general population, possibly due to sensitization via inhalation and higher exposure. However, the response of the bronchial epithelium to fish allergens has never been explored. Parvalbumins (PVs) from bony fish are major sensitizers in fish allergy, while cartilaginous fish and their PVs are considered less allergenic. Increasing evidence demonstrates that components other than proteins from the allergen source, such as low molecular weight components smaller than 3 kDa (LMC) from pollen, may act as adjuvants during allergic sensitization.

We investigated the response of bronchial epithelial cells to PVs and to LMC from Atlantic cod, a bony fish, and gummy shark, a cartilaginous fish. Polarized monolayers of the bronchial epithelial cell line 16HBE14o- were stimulated apically with fish PVs and/-or the corresponding fish LMC. Barrier integrity, transport of PVs across the monolayers and release of mediators were monitored.

Intact PVs from both the bony and the cartilaginous fish were rapidly internalized by the cells and transported to the basolateral side of the monolayers. The PVs did not disrupt the epithelial barrier integrity nor did they modify the release of proinflammatory cytokines. In contrast, LMC from both fish species modified the physical and immunological properties of the epithelial barrier and the responses differed between bony and cartilaginous fish. While the barrier integrity was lowered by cod LMC 24 h after cell stimulation, it was increased by up to 2.3-fold by shark LMC. Furthermore, LMC from both fish species increased basolateral and apical release of IL-6 and IL-8, while CCL2 release was increased by cod but not by shark LMC.

In summary, our study demonstrated the rapid transport of PVs across the epithelium which may result in their availability to antigen presenting cells required for allergic sensitization. Moreover, different cell responses to LMC derived from bony versus cartilaginous fish were observed, which may play a role in different allergenic potentials of these two fish classes.

Exploring the Utility of Noninvasive Type 2 Inflammatory Markers for Prediction of Severe Asthma Exacerbations in Children and Adolescents

BACKGROUND

Noninvasive markers of type 2 inflammation are needed to identify children and adolescents who might benefit from personalized biologic therapy.

OBJECTIVE

We hypothesized that blood eosinophil counts would predict 1 or more acute visits for asthma and that prediction could be improved with the addition of a second, noninvasive type 2 inflammatory biomarker.

METHODS

Children and adolescents 5 to 21 years (N = 589) with an asthma exacerbation necessitating systemic corticosteroid treatment in the previous year completed a characterization visit and telephone calls at 6 and 12 months. The primary outcome was an acute visit for asthma with receipt of systemic corticosteroids. Acute visits were verified by medical record review. Exploratory outcomes included time to first acute visit and hospitalization.

RESULTS

Acute visits occurred in 106 (35.5%) children and 72 (24.8%) adolescents. Elevated blood eosinophils were associated with increased odds and shorter time to first acute visit, but optimal cut-points differed by age (≥150 vs ≥300 cells/μL for children vs adolescents, respectively). The addition of a second marker of type 2 inflammation did not improve prediction in children, but increased the odds and hazard of an acute visit up to 16.2% and 11.9%, respectively, in adolescents. Similar trends were noted for hospitalizations.

CONCLUSIONS

Blood eosinophils and other noninvasive markers of type 2 inflammation may be useful in the clinical assessment of children and adolescents with asthma. However, features of type 2 inflammation vary by age. Whether children and adolescents also respond differently to management of type 2 inflammation is unclear and warrants further evaluation.

High-Sensitivity C-Reactive Protein and Allergic Endpoints in German Adolescents

BACKGROUND

Assessing high-sensitivity C-reactive protein (hs-CRP) in relation to allergic endpoints can shed light on both the mechanisms of allergic disease development and early non-communicable disease prevention. However, only a few epidemiological studies so far have investigated the relationship in children and adolescents, and the results were mixed.

OBJECTIVES

We sought to examine the interrelation between hs-CRP levels and allergic outcomes using a larger population size and a longitudinal study design.

METHODS

Complete data were available on 1,955 participants from the 15-years follow-up of the 2 large population-based German birth cohorts - GINIplus and LISA. Serum hs-CRP concentrations were measured using the immunoturbidimetric high-sensitive assay. Six allergic endpoints were used - doctor-diagnosed asthma, doctor-diagnosed eczema, doctor-diagnosed allergic rhinitis, food sensitization, aeroallergen sensitization, and any sensitization. We used generalized estimation equation models to assess the associations between hs-CRP levels and allergic endpoints.

RESULTS

Our longitudinal analyses did not detect any significant association between hs-CRP levels and any of the studied allergic outcomes (e.g., asthma, eczema, allergic rhinitis, food sensitization, aeroallergen sensitization, and any sensitization). The results were consistent in a series of sensitivity analyses.

CONCLUSIONS

Our study suggests that there is no association between hs-CRP levels and any of the allergic endpoints in German adolescents. However, whether allergic diseases are inflammatory conditions and which markers might be most sensitive, remain to be confirmed in future studies.

Update on Interventions in Prevention and Treatment of Pediatric Asthma

BACKGROUND

Asthma represents a worldwide health problem with a strong morbidity and a major impact on the health care system. Multiple efforts have been made towards the development of new strategies for the prevention and treatment of this disorder. In the light of this the present review of the literature aimed at summarizing the latest advances in prevention and treatment of pediatric asthma with a focus on the most effective options of interventions during the first stages of life.

METHODS

References were identified by searches of PubMed. Search terms used in the search were "pediatric asthma", "treatment" and "prevention". We included only meta-analysis, randomized controlled trials, reviews and systematic review articles pertaining to humans and subjects aged 0-18 years. All the interventions have been classified as "non-pharmacological" and "pharmacological".

RESULTS

Non-pharmacological interventions have been focused in identifying the genetic and environmental factors underlying the pathogenesis of this disease, including the individual genetic susceptibility, the early allergic sensitization, the role of the environmental microbiome and the exposure to infections and to pollutants. Moreover, the optimization of the existing pharmacological strategies and the development of new treatment options have improved markedly the management of this disease, thereby reducing the health care costs and ameliorating the quality of life of patients.

CONCLUSION

Childhood asthma prevention and treatment still represents a worldwide challenge. Future efforts should be aimed at identifying high risk target populations, minimizing the costs of each policy of intervention and increasing adherence to treatment strategies.

Allergic sensitization increases the amount of extracellular ATP hydrolyzed by guinea pig leukocytes

Increased levels of ATP have been found in the bronchoalveolar lavage of patients with asthma, and subjects with this disease, but not healthy subjects, develop bronchospasm after nebulization with ATP. Because the main mechanism for controlling the noxious effects of extracellular ATP is its enzymatic hydrolysis, we hypothesized that allergic sensitization is accompanied by a decreased functioning of such hydrolysis. In the present study, peripheral blood leukocytes from sensitized and non-sensitized guinea pigs were used for determining the extracellular metabolism (as assessed by inorganic phosphate production) of ATP, ADP, AMP, or adenosine, and for detecting possible changes in the expression (qPCR and Western blot) of major ectonucleotidases (NTPDase1, NTPDase3, and NPP1) and purinoceptors (P2X₁, P2X₇, P2Y₄, and P2Y₆). Contrary to our hypothesis, we found that leukocytes from allergic animals produced higher amounts of inorganic phosphate after stimulation with ATP and ADP, as compared with leukocytes from non-sensitized animals. Although at first glance, this result suggested that sensitization caused higher efficiency of ectonucleotidases, their mRNA and protein expressions were unaffected. On the other hand, after sensitization, we found a significant increase in the protein expression of P2X₇ and P2Y₄, two purinoceptors known to be responsible for ATP release after activation. We concluded that allergic sensitization increased the amount of ATP hydrolyzed by ectonucleotidases, the latter probably not due to the enhanced efficiency of its enzymatic breakdown, but rather due to an increased release of endogenous ATP or other nucleotides, partly mediated by enhanced expression or P2X₇ and P2Y₄ receptors.

Vaccination and Allergic Sensitization in Early Childhood - The ALADDIN Birth Cohort

BACKGROUND

The increasing incidence of allergic diseases highlights the importance of finding underlying mechanisms. Early vaccination has been suggested as one influential factor. However, it is difficult to find a study group with a large variation between subjects concerning compliance to the official vaccination program. The anthroposophic lifestyle is of interest in this context. Moreover, cohort studies show that children of families with this lifestyle run a lower risk of allergic sensitization and allergy-related disease.

METHODS

From the prospective birth cohort ALADDIN we included one group from the anthroposophic community, with restrictive attitudes concerning vaccinations, and two other groups of age-matched children with more conventional parental lifestyles. In all, 466 children were followed from birth to five years of age. Detailed vaccination data and blood samples were collected at six months, one, two, and five years. Information was also obtained on risk factors for allergy. The outcome variable, allergic sensitization was defined as allergen-specific serum IgE levels ≥ 0.35 kU_A/L.

FINDINGS

In a logistic regression model adjusted for socio-demographics and established allergy risk factors, vaccination at later age or having a lower number of injections or vaccines were associated with low OR for allergic sensitization during the first year of life. However, after adjustment for anthroposophic lifestyle, no statistically significant associations remained. The adjusted OR for sensitization at five years of age in children not receiving any vaccinations (n = 54) was 0.98 [95% CI 0.38-2.57].

INTERPRETATION

We found no support for an association between early childhood vaccination and subsequent allergic sensitization. Our findings do not support scepticism towards early childhood vaccination motivated by allergy risk.

Rational Approach to Allergy Testing

Allergy testing is commonly used when symptoms of allergic rhinitis are refractory to symptoms and there is potential for treatment with institution of avoidance measures or immunotherapy. Once the decision for testing has been made, the method of testing by either in vivo skin testing by prick/puncture or intradermal testing or in vitro testing of serum-specific IgE is dictated by factors in the clinical history and an informed decision by the patient. Because there is no perfect testing method, understanding the benefits and limitations of each method is important in selecting the best testing option for each patient.

Type 2 immunity in asthma

Type 2-immunity represents the typical adaptive response to allergen exposure in atopic individuals. It mainly involves Th2 cells and immunoglobulin E, as the main orchestrators of type 2-inflammation. Recently, it has been highlighted that allergens may be responsible for a Th2 response beside specific IgE activation and that a number of other environmental stimuli, such as viruses and pollutants, can trigger the same pattern of inflammation beyond atopy. Emerging data sustain a substantial role of the so-called epithelial dysfunction in asthma pathogenesis, both from anatomic and functional point of view. Furthermore an increasing amount of evidence demonstrates the relevance of innate immunity in polarizing a Th2 impaired response in asthmatic patients. Under this perspective, the complex cross-talking between airway epithelium, innate and adaptive immunity is emerging as a major determinant of type 2-inflammation beyond allergens.

This review will include an update on the relevance of dysregulation of innate and adaptive type 2-immunity in asthma pathogenesis, particularly severe asthma, and on the role of the allergens that are associated with severe asthma. Type 2-immunity also will be reviewed in the light of the current and upcoming targeted treatments for severe asthma.

Allergic sensitization to common pets (cats/dogs) according to different possible modalities of exposure: an Italian Multicenter Study

Background

The query "are there animals at home?" is usually administered for collecting information on anamnesis. This modality to consider exposure to pet allergens constitutes a potential bias in epidemiological studies and in clinical practice. The aim of our study was to evaluate/quantify different modalities of exposure to cat/dog in inducing allergic sensitization.

Methods

Thirty Italian Allergy units participated in this study. Each centre was required to collect the data of at least 20 consecutive outpatients sensitized to cat/dog allergens. A standardized form reported all demographic data and a particular attention was paid in relieving possible modalities of exposure to cat/dog.

Results

A total 723 patients sensitized to cat/dog were recorded, 359 (49.65%) reported direct pet contact, 213 patients (29.46%) were pet owners, and 146 subjects (20.19%) were exposed to pets in other settings. Other patients were sensitized by previous pet ownership (150-20.75%) or indirect contact (103-14.25%), in 111 subjects (15.35%) any contact was reported.

Conclusions

Only 213 patients (29.46%) would be classified as "exposed to animals" and 510 (70.54%) as "not exposed" according to usual query. Our classification has shown that many "not-exposed" subjects (399-55.19%) were "really exposed". The magnitude of exposure to pet allergens at home is not related exclusively to pet ownership. These considerations should be taken into account during the planning of epidemiological studies and in clinical practice for the management of pet allergic individuals.

Allergic sensitization to common pets (cats/dogs) according to different possible modalities of exposure: an Italian Multicenter Study

Background

The query “are there animals at home?” is usually administered for collecting information on anamnesis. This modality to consider exposure to pet allergens constitutes a potential bias in epidemiological studies and in clinical practice. The aim of our study was to evaluate/quantify different modalities of exposure to cat/dog in inducing allergic sensitization.

Methods

Thirty Italian Allergy units participated in this study. Each centre was required to collect the data of at least 20 consecutive outpatients sensitized to cat/dog allergens. A standardized form reported all demographic data and a particular attention was paid in relieving possible modalities of exposure to cat/dog.

Results

A total 723 patients sensitized to cat/dog were recorded, 359 (49.65%) reported direct pet contact, 213 patients (29.46%) were pet owners, and 146 subjects (20.19%) were exposed to pets in other settings. Other patients were sensitized by previous pet ownership (150–20.75%) or indirect contact (103–14.25%), in 111 subjects (15.35%) any contact was reported.

Conclusions

Only 213 patients (29.46%) would be classified as “exposed to animals” and 510 (70.54%) as “not exposed” according to usual query. Our classification has shown that many “not-exposed” subjects (399–55.19%) were “really exposed”. The magnitude of exposure to pet allergens at home is not related exclusively to pet ownership. These considerations should be taken into account during the planning of epidemiological studies and in clinical practice for the management of pet allergic individuals.

Association of Japanese cedar pollinosis and sensitization with HLA-DPB1 in the Japanese adolescent

BACKGROUND

Allergic rhinitis (AR) is a heterogeneous disorder that significantly affects daily activity, work productivity, sleep, learning, and quality of life in all generations. Japanese cedar (JC) pollen is the most common allergen responsible for the development of AR in Japan. AR caused by JC pollen is considered to be a multifactorial inheritance disease that is caused by both environmental and genetic factors. The aim of this study was to investigate whether Human Leukocyte Antigen-DPB1 (HLA-DPB1) is associated with JC sensitization/pollinosis.

METHODS

Subjects in the present study were 544 students at the University of Tsukuba from 2013 to 2015. PCR-SSOP was performed to determine each individual's HLA-DPB1 alleles. Logistic regression analysis was performed to examine relationships between JC-related phenotypes and alleles/amino acid polymorphisms of HLA-DPB1.

RESULTS

HLA-DPB1*02 allele were significantly associated with both JC sensitization/pollinosis (q < 0.05). Furthermore, HLA-DPB1*02:01 and HLA-DPB1*02:02 had a protective tendency for JC sensitization/pollinosis, and HLA-DPB1*05:01 had a susceptible tendency for sensitization (P < 0.05). In amino acid polymorphism analyses, Glutamic acid in position 69, Glycine-Glycine-Proline-Methionine in positions 84-87, Threonine in position 170 and Methionine in position 205 were also observed to have a protective tendency for JC sensitization (P < 0.05). Amino acid positions 69 and 84-87 were located in binding pocket 5 and 1 of HLA-DPβ1, respectively.

CONCLUSIONS

Amino acid changes in the allergen-binding pocket of HLA-DPβ1 are likely to influence pollinosis/sensitization to the allergenic peptide of JC pollen and determine the pollinosis risk for each individual exposed to JC pollen.

Frequency and effect of type 1 hypersensitivity in patients from India with chronic obstructive pulmonary disease and associated upper airways symptoms

Background

Chronic obstructive pulmonary disease (COPD) is now recognized as a systemic disorder with many comorbidities. Atopy in patients with COPD and upper airways symptoms has not been characterized.

Objective

We investigated the occurrence and impact of aeroallergen sensitisation in patients with COPD and upper airways symptoms.

Methods

All 41 subjects with COPD diagnosed as per Global Initiative for Chronic Obstructive Lung Disease guidelines, underwent spirometry with reversibility, computed tomography of the paranasal sinuses (CT-PNS), skin prick test (SPT) against common aeroallergens and responded to St. George's Respiratory Questionnaire (SGRQ) and Sino Nasal Outcome Test - 22 (SNOT-22) questionnaires. Upper airways symptoms were assessed as per the Allergic Rhinitis and its Impact on Asthma guidelines.

Results

As documented earlier, 27 of the 41 patients (65.9%) with COPD had upper airways symptoms. Of these 27 patients, 11 had SPT positivity against at least one aeroallergen (group 1). One patient had monosensitisation to pollens of grass Imperata while polysensitisation was seen in 10/11 patients commonly to weeds, trees, and insects. Fungal sensitisation to Aspergillus fumigatus was seen in 3 of 11 patients (27.2%). In group 1, all 11 patients (100%) had radiological sinusitis as compared to 8 of 16 (50%) in group 2. The mean CT-PNS scores were significantly higher in group 1 as compared to group 2. Similarly, the SNOT-22 scores were significantly higher in group 1 as compared to group 2. However, there was no difference in SGRQ scores between the 2 groups. In group 1, there was a significant correlation between CT-PNS and SNOT-22 scores.

Conclusion

Patients with COPD, associated upper airways symptoms and a positive SPT had a significantly higher frequency of radiological sinusitis on CT-PNS. They even had worse quality of life as compared to those with a negative SPT. The study suggested that atopic patients with COPD and upper airways involvement were more symptomatic. It is therefore possible that upper airways symptoms, if left untreated, would result in less than desirable control of the disease.

Eight Aeroallergen Skin Extracts May Be the Optimal Panel for Allergic Rhinitis Patients in Central China

BACKGROUND

The prevalence of allergic rhinitis (AR) is increasing rapidly in Central China. The skin prick test (SPT) is the standard tool with which to determine the allergen sensitization status in AR patients. Changes in allergen sensitization patterns have been observed within countries and regions due to geographical and seasonal variations.

OBJECTIVE

The aim of this study was to evaluate the profile of SPT reactivity to different aeroallergens in AR patients and to suggest a minimal panel of allergens to detect sensitized patients in Central China.

METHODS

From January 2015 to December 2016, patients who presented to Tongji Hospital with suspected AR were tested with the same panel of 19 aeroallergens. The results of SPT were analyzed to determine the minimum test battery panel necessary to cover 99% of the cases of SPT sensitization in different age subgroups.

RESULTS

A total of 2,416 patients (male:female ratio 1.2:1) were enrolled in our study with an average age of 22.0 years. The overall rate of sensitization to any allergen was 79.0%, and 64.3% of the subjects were monosensitized. The highest sensitized rate was found in the subgroup aged 14-18 years (92.0%), followed by the subgroups of 6-14 years (86.4%), >18 years (75.6%), and ≤6 years (74.9%). The most common sensitization was to Dermatophagoides farinae (71.1%). Testing with 8 allergens (D. pteronyssinus, D. farinae, Platanus, Artemisia, Cryptomeria, Blatella germanica, Humulus, and Alternaria) was sufficient to identify over 99% of the sensitized patients.

CONCLUSION

An SPT panel covering 8 allergen extracts was able to detect almost all sensitized patients suffering from AR symptoms in Central China.

Is peanut causing food allergy in Cuba? Preliminary assessment of allergic sensitization and IgE specificity profile to peanut allergens in Cuban allergic patients

Background

Peanut allergy is increasing at an alarming pace in developed countries. Peanut (Arachis hypogaea) is a common food in Cuba. Nevertheless, reported values of sensitization and symptom severity are usually low. As our objective, we carried out an evaluation of allergic sensitivity to perform an assessment of allergic sensitization and IgE specificity profile to peanut allergens in Cuban allergic patients.

Methods

The Skin Prick Test (SPT) was performed for each patient, using two glycerinated allergenic extracts, prepared from raw or roasted peanuts. Overall, 316 food allergic patients (159 adults and 157 children) attending allergy services at four hospitals in Havana were included, as well as 303 adult non- allergic volunteers. The IgE binding profile of 26 selected SPT positive patients was further analyzed by immunoblotting.

Results

The prevalence of sensitization to peanut was 4.6% in general adult population, whereas in adult food-allergic patients it was 18.6%. Prevalence rates were even greater in food allergic children achieving 25.8%. Sensitization frequencies were apparently greater for roasted, as compared to raw peanuts, although the difference was not significant (p> 0.05, Mc Nemar's). IgE binding was shown mostly by the 15 and 17 kDa bands, tentatively identified as the major allergens Ara h 2 and Ara h 6. The IgG4 binding profile was similar to IgE, although with more prominence of the bands at 37 and 28 KDa, corresponding to an Ara h 3 fragment and Peanut Agglutinin.

Discussion

The study estimated a relatively high prevalence of peanut sensitization in population. Data reported here suggest that IgE sensitization in Cuban patients is focused mostly on MW bands corresponding to the major allergens Ara h 6 and Ara h 2.

Conclusions

Sensitization to peanut allergen is indeed relatively frequent in Cuba. The IgE profile is congruent to a sensitization pattern by ingestion of roasted peanuts and is directed to well-known major allergens.

Effects of Allergic Sensitization on Antiviral Immunity: Allergen, Virus, and Host Cell Mechanisms

PURPOSE OF REVIEW

Multiple clinical and epidemiological studies demonstrate links between allergic sensitization and virus-induced atopic disease exacerbations. This review summarizes the recent findings regarding allergen, viral, and host cellular mechanisms relevant to these observations.

RECENT FINDINGS

Recent studies have focused on the molecular pathways and genetic influences involved in allergen-mediated inhibition of innate antiviral immune responses. Multiple tissue and cell types from atopic individuals across the atopy spectrum exhibit deficient interferon responses to a variety of virus infections. Impairment in barrier function, viral RNA and DNA recognition by intracellular sensing molecules, and dysregulation of signaling components are broadly affected by allergic sensitization. Finally, genetic predisposition by numerous nucleotide polymorphisms also impacts immune pathways and potentially contributes to virus-associated atopic disease pathogenesis. Allergen-virus interactions in the setting of atopy involve complex tissue and cellular mechanisms. Future studies defining the pathways underlying these interactions could uncover potential therapeutic targets. Available data suggest that therapies tailored to restore specific components of antiviral responses will likely lead to improved clinical outcomes in allergic disease.