Prevalence of allergic sensitization versus allergic rhinitis symptoms in an unselected population

Poor Rhinitis and Asthma Control Is Associated With Decreased Health-Related Quality of Life and Utilities: A MASK-air Study

BACKGROUND

Allergic rhinitis (AR) and asthma may affect health-related quality of life. However, national estimates on the quality of life of patients with AR or asthma are lacking.

OBJECTIVE

To provide estimates for utility scores and EuroQoL five-dimension (EQ-5D) visual analog scale (VAS) for patients with AR or asthma.

METHODS

We conducted a cross-sectional study using direct patient data from the MASK-air app on European MASK-air users with self-reported AR or asthma. We used a multi-attribute instrument (EQ-5D) to measure quality of life (as utility scores and EQ-5D VAS values). Mean scores were calculated per country and disease control level using multilevel regression models with poststratification, accounting for age and sex biases.

RESULTS

We assessed data from 7905 MASK-air users reporting a total of up to 82,737 days. For AR, utilities ranged from 0.86 to 0.99 for good control versus 0.72 to 0.85 for poor control; EQ-5D VAS levels ranged from 78.9 to 87.9 for good control versus 55.3 to 64.2 for poor control. For asthma, utilities ranged from 0.84 to 0.97 for good control versus 0.73 to 0.87 for poor control; EQ-5D VAS levels ranged from 68.4 to 81.5 for good control versus 51.4 to 64.2 for poor control. Poor disease control was associated with a mean loss of 0.14 utilities for both AR and asthma. For the same control levels, AR and asthma were associated with similar utilities and EQ-5D VAS levels. However, lower values were observed for asthma plus AR compared with AR alone.

CONCLUSIONS

Poor AR or asthma control are associated with reduced quality of life. The estimates obtained from mobile health data may provide valuable insights for health technology assessment studies.

Revealing clinically relevant specific IgE sensitization patterns in Hymenoptera venom allergy with dimension reduction and clustering

Background

Immunoglobulin E (IgE) blood tests are used to detect sensitizations and potential allergies. Recent studies suggest that specific IgE sensitization patterns due to molecular interactions affect an individual's risk of developing allergic symptoms.

Objective

The aim of this study was to reveal specific IgE sensitization patterns and investigate their clinical implications in Hymenoptera venom allergy.

Methods

In this cross-sectional study, 257 hunters or fishers with self-filled surveys on previous Hymenoptera stings were analyzed. Blood samples were taken to determine Hymenoptera IgE sensitization levels. Using dimensionality reduction and clustering, specific IgE for 10 Hymenoptera venom allergens were evaluated for clinical relevance.

Results

Three clusters were unmasked using novel dimensionality reduction and clustering methods solely based on specific IgE levels to Hymenoptera venom allergens. These clusters show different characteristics regarding previous systemic reactions to Hymenoptera stings.

Conclusion

Our study was able to unmask non-linear sensitization patterns for specific IgE tests in Hymenoptera venom allergy. We were able to derive risk clusters for anaphylactic reactions following hymenoptera stings and pinpoint relevant allergens (rApi m 10, rVes v 1, whole bee, and wasp venom) for clustering.

A Clinical Approach of Allergic Rhinitis in Children

Allergic rhinitis is an important disease with a global footprint and a growing prevalence, affecting children and adults. Although it is commonly under-diagnosed and under-treated, it causes important social and economic effects (diminished quality of life, poor academic performance, escalated medical visits, heightened medication usage, and effects in other chronic conditions, e.g., asthma). It is characterized by distinctive, easily identifiable symptoms (sneezing, nasal discharge, nasal congestion, nasal-eye-palatal itching) and indirect accompanying indicators (fatigue and decreased school performance). The classification of allergic rhinitis hinges upon its nature and chronic distribution (seasonal or perennial) and its intensity, which spans from mild to moderate and severe. The diagnostic process primarily relies upon recognizing key clinical indicators, evaluating historical records, and considering risk factors. It is supported by abnormal laboratory findings, like in vitro allergen-specific IgE tests (enzyme immunoassay-EIA, chemiluminense immunoassay-CLIA) or in vivo skin prick tests for specific allergens. In the differential diagnosis, other chronic diseases manifesting with chronic rhinitis should be excluded (e.g., rhinosinusitis, chronic non-allergic rhinitis, rhinitis triggered by medications). The treatment of allergic rhinitis in children is mainly chronic and is focused on allergen exposure prevention, drug therapy, and immunotherapy in severe cases. Locally administered intranasal corticosteroids are the cornerstone of therapy. They are safe, effective, and have a favorable safety profile even during long-term use. Choosing a suitable intranasal corticosteroid drug with low systemic bioavailability makes long-term treatment even safer. Combinations of intranasal corticosteroids and H1 antihistamines are available in several countries and are widely used in more severe cases and the presence of year-round symptoms. Adding newer-generation oral H1-antihistamines broadens the available therapeutic inventory without significant effects compared to using previous-generation, once widely available, H1-antihistamines. Treatment of allergic rhinitis is complex and multi-dimensional, requiring an effective approach by a specialized group of specialized pediatricians, and is severely affected by the concurrent presence or development of other diseases in the spectrum of allergic diseases (conjunctivitis, asthma).

Analysis of Multimorbidity of Moderate to Severe Allergic Rhinitis in Children: A Real-World Study

INTRODUCTION

Allergic rhinitis (AR) in children is associated with various comorbidities, posing challenges for treatment and management. There have been few investigations of these multimorbidities in Chinese children with AR. Here, we investigated the prevalence of multimorbidities in children with moderate to severe AR and analyzed the influencing factors using real-world data.

METHODS

In total, 600 children who visited the outpatient clinic of our hospital and were diagnosed with moderate-severe AR were prospectively enrolled. All children underwent allergen detection and electronic nasopharyngoscopy. Parents or guardians completed a questionnaire that included age, sex, mode of delivery, feeding pattern, and familial history of allergy. The multimorbidities investigated included atopic dermatitis (AD), asthma, allergic conjunctivitis (AC), chronic rhinosinusitis (CRS), adenoid hypertrophy (AH), tonsil hypertrophy (TH), recurrent epistaxis, and recurrent respiratory tract infections (RRTIs).

RESULTS

The AR multimorbidities reported in children were as follows: recurrent epistaxis (46.5%), AC (46.3%), AD (40.7%), asthma (22.5%), RRIs (21.3%), CRS (20.5%), AH (19.7%), and TH (12.5%). In univariate logistic regression analysis, age (<6 years), birth mode, familial history of allergy, and single dust mite allergy were associated with AR multimorbidity (p < 0.05). Multivariate logistic regression revealed that a familial history of allergy was an independent risk factor for AC (odds ratio [OR] = 1.539, 95% confidence interval [CI]: 1.104-2.145) and AH (OR = 1.506, 95% CI: 1.000-2.267) (p < 0.05). Age (<6 years) was independently associated with the risk of AD (OR = 1.405, 95% CI: 1.003-1.969) and RRTIs (OR = 1.869, 95% CI: 1.250-2.793) (p < 0.05), cesarean section with AR and CRS risk (OR = 1.678, 95% CI: 1.100-2.561), and single dust mite allergy with asthma (OR = 1.590, 95% CI: 1.040-2.432) and CRS (OR = 1.600, 95% CI: 1.018-2.515) risk (p < 0.05). Further, non-dust mite allergy was independently associated with AR and CRS (OR = 2.056, 95% CI: 1.084-3.899).

CONCLUSION

AR was found to be accompanied by different comorbidities, including both allergic and non-allergic comorbidities, complicating disease treatment. These findings demonstrated that age (<6 years), familial history of allergy, types of allergens, and cesarean section were risk factors for different multimorbidities associated with AR.

Current allergy educational needs in primary care. Results of the EAACI working group on primary care survey exploring the confidence to manage and the opportunity to refer patients with allergy

The aim of this survey was to explore the specific educational needs of a cohort of European GPs with regards to allergy training so that future educational initiatives may better support the delivery of allergy services in primary care.

METHOD

This study took the form of a cross-sectional observational study in which a structured electronic questionnaire was distributed to primary care providers, in eight languages, across 8 European countries between September 2019 and November 2019. Data associated with demographic parameters, professional qualifications, type of employment, level of confidence regarding competencies for diagnosis and treatment of allergic diseases, referral of patients to allergist and preferred method of learning and assessment were collected. A 5-point Likert scale was used to assess level of confidence. Exploratory analysis was carried out.

RESULTS

A total of 687 responses were available for analysis, with 99.3% of responders working within Europe. 70.1% of participants were female; and 48.0% and 48.0% of participants respectively had received some undergraduate and/or postgraduate allergy education. Confidence in dealing with different aspect of allergy management differed between countries. The main reason for specialist referral was a perceived need for tertiary assessment (54.3%), and the main barrier for referral was the consideration that the patient's condition could be appropriately diagnosed and treated in a primary care facility. Up to 44.7% and 55.3% of participants reported that they preferred e-Learning over traditional learning.

CONCLUSIONS

This study identified the specific areas of skills training and educational needs of GPs in managing allergic conditions in primary care, and provided insights into possible strategies for more feasible and cost-effective approaches.

How reliable is anamnestic data in predicting the clinical relevance of house dust mite sensitization?

PURPOSE

For perennial inhalant allergens such as house dust mite (HDM), the German guideline on allergen-specific immunotherapy explicitly recommends provocation testing. This procedure is time-consuming, expensive, and potentially dangerous for the patient. Recently it has been discussed whether provocation tests are really necessary for diagnosing allergy to Dermatophagoides species. Thus, our study aimed to analyze the concordance between nasal provocation tests with Dermatophagoides species and anamnestic data.

METHODS

We retrospectively analyzed the concordance between patients' histories including self-reported symptom scores and the results of provocation testing in 471 individuals with proven sensitization to Dermatophagoides species.

RESULTS

248 patients had a positive nasal provocation test (NPT) result to Dermatophagoides species and 223 individuals a negative NPT result. Patients allergic to HSM suffered significantly more often from atopic dermatitis (14% vs. 7%, p = 0.046) and more from asthma (20% vs. 19%, p = 0.851). Moreover, individuals with clinically silent sensitization complained less about nasal secretion (37% vs. 45%, p = 0.244) but significantly more about nasal dryness (46% vs. 34%, p = 0.046) whereas rates of nasal airway obstruction, ocular complaints and sleep quality were comparable in both groups. Allergic patients reported more often perennial (34% vs. 30%, p = 0.374) and location-dependent (39% vs. 31%, p = 0.090) symptoms. However, the discrepant prevalence of atopic dermatitis was the only statistically significant difference between both groups.

CONCLUSION

Despite slight differences between both patient groups, clinical data are not sufficient to distinguish between silent sensitization and clinically relevant allergic rhinitis to HDM. Therefore, nasal provocation testing remains the gold standard for assessing clinical relevance in patients sensitized to Dermatophagoides species.

Study of the Expected Impact of Palm Pollen on Human Respiratory Tract Allergy

&lt;b&gt;Background and Objective:&lt;/b&gt; Date-Palm trees (&lt;i&gt;Phoenix dactylifera&lt;/i&gt; L.) are the most abundant crop in Saudi Arabia. Date Palm Pollen (DPP) are considered an important allergens. The reasons for the increase in susceptibility to allergy are not clear. This investigation aimed to link the size, shape, moisture contents and biogenic contents of the collected pollens to susceptibility. &lt;b&gt;Materials and Methods:&lt;/b&gt; Pollens were collected from three different regions in the Kingdom. Date palm pollen sizes were determined in wet and dry states by Microtrac. A microscope with a camera was used to image the forms of date palm pollens. The biogenic amines were determined after extraction using HPLC. Data were analyzed by one-way analysis of variance (ANOVA), using SPSS version 16.0. &lt;b&gt;Results:&lt;/b&gt; There was a variation in the sizes of pollens from different regions ranging between 3.3-704 μm. Most pollen grains are spherical. The concentrations of six biogenic amines were detected in all samples but with different concentrations. They included B-phenyl ethylamine, Putrescine, Cadaverine, Histamine, Tyramine and Spermidine. &lt;b&gt;Conclusion:&lt;/b&gt; The shape and size of the pollen grains studied were variable and will not facilitate deep penetration into the respiratory system but their biogenic contents were very high and suggested to cause allergy.

Long-Term Pollen Monitoring in the Benelux: Evaluation of Allergenic Pollen Levels and Temporal Variations of Pollen Seasons

Airborne pollen is a major cause of allergic rhinitis, affecting between 10 and 30% of the population in Belgium, the Netherlands, and Luxembourg (Benelux). Allergenic pollen is produced by wind pollinating plants and released in relatively low to massive amounts. Current climate changes, in combination with increasing urbanization, are likely to affect the presence of airborne allergenic pollen with respect to exposure intensity, timing as well as duration. Detailed analysis of long-term temporal trends at supranational scale may provide more comprehensive insight into these phenomena. To this end, the Spearman correlation was used to statistically compare the temporal trends in airborne pollen concentration monitored at the aerobiological stations which gathered the longest time-series (30–44 years) in the Benelux with a focus on the allergenic pollen taxa: Alnus, Corylus, Betula, Fraxinus, Quercus, Platanus, Poaceae, and Artemisia. Most arboreal species showed an overall trend toward an increase in the annual pollen integral and peak values and an overall trend toward an earlier start and end of the pollen season, which for Betula resulted in a significant decrease in season length. For the herbaceous species (Poaceae and Artemisia), the annual pollen integral and peak values showed a decreasing trend. The season timing of Poaceae showed a trend toward earlier starts and longer seasons in all locations. In all, these results show that temporal variations in pollen levels almost always follow a common trend in the Benelux, suggesting a similar force of climate change-driven factors, especially for Betula where a clear positive correlation was found between changes in temperature and pollen release over time. However, some trends were more local-specific indicating the influence of other environmental factors, e.g., the increasing urbanization in the surroundings of these monitoring locations. The dynamics in the observed trends can impact allergic patients by increasing the severity of symptoms, upsetting the habit of timing of the season, complicating diagnosis due to overlapping pollen seasons and the emergence of new symptoms due allergens that were weak at first.

Treatable Traits in Elderly Asthmatics from the Australasian Severe Asthma Network: A Prospective Cohort Study

BACKGROUND

Data on treatable traits (TTs) in different populations are limited.

OBJECTIVE

To assess TTs in elderly patients with asthma and compare them to younger patients, to evaluate the association of TTs with future exacerbations, and to develop an exacerbation prediction model.

METHODS

We consecutively recruited 521 participants at West China Hospital, Sichuan University based on the Australasian Severe Asthma Network, classified as elderly (n = 62) and nonelderly (n = 459). Participants underwent a multidimensional assessment to characterize the TTs and were then followed up for 12 months. TTs and their relationship with future exacerbations were described. Based on the TTs and asthma control levels, an exacerbation prediction model was developed, and the overall performance was externally validated in an independent cohort.

RESULTS

A total of 38 TTs were assessed. Elderly patients with asthma had more chronic metabolic diseases, fixed airflow limitation, emphysema, and neutrophilic inflammation, whereas nonelderly patients with asthma exhibited more allergic characteristics and psychiatric diseases. Nine traits were associated with increased future exacerbations, of which exacerbation prone, upper respiratory infection-induced asthma attack, cardiovascular disease, diabetes, and depression were the strongest. A model including exacerbation prone, psychiatric disease, cardiovascular disease, upper respiratory infection-induced asthma attack, noneosinophilic inflammation, cachexia, food allergy, and asthma control was developed to predict exacerbation risk and showed good performance.

CONCLUSIONS

TTs can be systematically assessed in elderly patients with asthma, some of which are associated with future exacerbations, proving their clinical utility of evaluating them. A model based on TTs can be used to predict exacerbation risk in people with asthma.

Modelling grass pollen levels in Belgium

Biogenic aerosols such as airborne grass pollen affect the public health badly by putting additional distress on people already suffering from cardiovascular and respiratory diseases. In Belgium, daily airborne pollen concentrations are monitored offline at a few sites only, hampering the timely coverage of the country and short-term forecasts. Here we apply the Chemistry Transport Model SILAM to the Belgian territory to model the spatio-temporal airborne grass pollen levels near the surface based on bottom-up inventories of grass pollen emissions updated with the Copernicus land monitoring Service grassland map of 2015. Transport of aerosols in SILAM is driven by ECMWF ERA5 meteorological data. The emitted grass pollen amounts in SILAM are computed by the multiplication of the grass pollen source map with the release rate determined by the seasonal shape production curve during the grass flowering period. The onset and offset of this period follow a location-dependent prescribed calendar days. Here we optimize the grass pollen seasonal start and end in SILAM by comparing a 2008-2018 time series of daily airborne grass pollen concentrations from the Belgian aerobiological surveillance network with the simulations. The effect of the spatial distribution of grass pollen sources is quantified by constructing pollen source-receptor relations using model simulations with varying grass pollen emissions in five areas of the model domain as input. Up to 33% of the airborne grass pollen in one area was transport from others areas inside Belgium. Adjusting the start and end of the grass pollen season improved the model performance substantially by almost doubling the correlation with local observations. By introducing the temporal scaling of the inter-seasonal pollen amounts in the model, an additional R² increase up to 22% was obtained. Further improvements can be made by including more detailed grass pollen sources and more dynamic start and end dates of the pollen season.

Diagnostic characterization of respiratory allergies by means of a multiplex immunoassay

Allergic sensitization is commonly assessed in patients by performing the skin prick test (SPT) or determining specific immunoglobulin (IgE) levels in blood samples with the ImmunoCAP™ assay, which measures each allergen and sample separately. This paper explores the possibility to investigate respiratory allergies with a high throughput method, the Meso Scale Discovery (MSD) multiplex immunoassay, measuring IgE levels in low volumes of blood. The MSD multiplex immunoassay, developed and optimized with standards and allergens from Radim Diagnostics, was validated against the SPT and the ImmunoCAP assay. For 18 adults (15 respiratory allergy patients and three controls), blood collection and the SPT were performed within the same hour. Pearson correlations and Bland-Altman analysis showed high comparability of the MSD multiplex immunoassay with the SPT and the ImmunoCAP assay, except for house dust mite. The sensitivity of the MSD multiplexed assay was ≥78% for most allergens compared to the SPT and ImmunoCAP assay. Additionally, the specificity of the MSD multiplex immunoassay was ≥ 87% - the majority showing 100% specificity. Only the rye allergen had a low specificity when compared to the SPT, probably due to cross-reactivity. The reproducibility of the MSD multiplex immunoassay, assessed as intra- and interassay reproducibility and biological variability between different sampling moments, showed significantly high correlations (r = 0·943-1) for all tested subjects (apart from subject 13; r = 0·65-0·99). The MSD multiplex immunoassay is a reliable method to detect specific IgE levels against respiratory allergens in a multiplexed and high-throughput manner, using blood samples as small as from a finger prick.

Determinants of the utilization of allergy management measures among hay fever sufferers: a theory-based cross-sectional study

Background

The quality of life of chronically ill individuals, such as hay fever sufferers, is significantly dependent on their health behavior. This survey aimed to explain the health-related behavior of allergic individuals using the protection motivation theory (PMT) and the transtheoretical model (TTM).

Methods

The influencing variables stated by PMT were operationalized based on data from semistructured pilot interviews and a pretest with 12 individuals from the target population. The final questionnaire inquired perceived seriousness and severity of hay fever, response efficacy, response costs, self-efficacy, and the use of various hay fever management measures in relation to the TTM stages. Multivariate logistic regression was performed to investigate the relationships between the PMT constructs and the examined health behavior.

Results

A total of 569 allergic individuals completed the online questionnaire. Only 33.26% of allergic individuals were in the maintenance stage for treatment under medical supervision, and almost 60% preferred hay fever self-management. A total of 67.56% had a well-established habit of taking anti-allergic medication, but only 25.31% had undergone specific immunotherapy. The likelihood of seeking medical supervision was positively influenced by perceived severity (OR = 1.35, 95% CI: 1.02–1.81), perceived seriousness (OR = 2.12, 95% CI: 1.56–2.89), and self-efficacy (OR = 4.52, 95% CI: 3.11–6.65). The perceived severity of symptoms predicted the practice of hay fever self-management (OR = 1.60, 95% CI: 1.21–2.11), as well as anti-allergic medication intake (OR = 1.65, 95% CI: 1.16–2.35). The latter measure was also positively influenced by self-efficacy (OR = 1.52, 95% CI: 1.01–2.28) and hay fever self-management (OR = 4.76, 95% CI: 2.67–7.49). Undergoing specific immunotherapy was significantly predicted only by medical supervision (OR = 9.80, 95% CI: 8.16–13.80). Allergen avoidance was a strategy used by allergic individuals who preferred hay fever self-management (OR = 2.56, 95% CI: 1.87–3.52) and experienced notable symptom severity (OR = 2.12, 95% CI: 1.60–2.81).

Conclusion

Educational interventions that increase the awareness of health risks associated with inadequate hay fever management and measures to increase self-efficacy might be beneficial for the promotion of appropriate hay fever management among allergic individuals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-020-09959-w.

A new portable sampler to monitor pollen at street level in the environment of patients

Allergic rhinitis caused by pollen exposure is one of the most common allergic diseases. Therefore monitoring pollen levels in ambient air is an important tool in research and health care. Most European monitoring stations collect airborne pollen at rooftop levels for measurements in the larger surrounding of the sampling station, and not in the direct environment of sensitized subjects. Here we present the development and evaluation of a portable pollen sampler, called "Pollensniffer", that was designed to collect pollen in the immediate environment of allergic subjects. Validation of the Pollensniffer against the standard volumetric pollen sampler showed for most pollen types high correlations between the number of pollen collected by those two devices (Spearman's Correlation Coefficient > 0.8); the Pollensniffer appeared to collect on average 5.8 times more pollen per hour than the static sampler. Pollen monitoring was performed using this Pollensniffer at street level at 3 different locations in the city of Leiden during 22 weeks in 2017 and 21 weeks in 2018, during three 15-min periods a day and at one day in the week. The results showed that the pollen levels for birch and grass pollen can significantly differ from location to location and per time of day. Furthermore, the Pollensniffer measurements at street level showed that birch and grass pollen grains were detected 1 1/2 and 2-3 weeks, respectively, before detection at rooftop level. The street measurements show that allergic subjects can encounter varying pollen levels throughout the city and that they can be exposed to grass and birch pollen and may experience hay fever symptoms, even before the sampler at rooftop level registers these pollen.

Clinical Manifestations of Allergic Rhinitis by Age and Gender: A 12-Year Single-Center Study

OBJECTIVES

Currently, epidemiological data on allergic rhinitis collected through the skin prick test are scarce. Moreover, the relationship of age and sex to allergic rhinitis is not comprehensively understood. This study aimed to characterize allergic rhinitis and the associated clinical manifestations by age and sex.

METHODS

We retrospectively investigated data from 2883 patients who visited a single university hospital for rhinitis symptoms between January 2003 and December 2014. Of these 2883 patients, 1964 who underwent a skin prick test with 11 standardized allergen extracts and completed a nasal symptom questionnaire were enrolled. The clinical characteristics of allergen sensitization and nasal symptoms were analyzed by sex and age distribution.

RESULTS

The prevalence of allergen sensitization progressively decreased with age after peaking at between 20 and 29 years. The sensitization rate was higher in males than in females (P = .046). The sensitization rate to house dust mites decreased with age, while sensitization to mugwort and ragweed increased. Six allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, mugwort, trees, ragweed, and cats) were sufficient to identify >96% of patients with allergen sensitization. Nasal obstruction tended to decrease with age and was more prevalent in males (P = .002) than in females, while rhinorrhea (P = .007) and itching (P = .013) were more prevalent in females. Total nasal symptom scores did not differ by sex.

CONCLUSIONS

The clinical characteristics of allergic rhinitis, including allergen-sensitization patterns and related symptoms, varied by age and sex. Six common allergens could be sufficient to generate a cost-effective tool to identify allergic rhinitis.

Quantitative allergenicity risk assessment of food products containing yellow mealworm (Tenebrio molitor)

Insect-based foods are starting to enter the EU market, raising concerns about their safety. Allergic consumers might be exposed to even a greater risk, since insects have proven to trigger allergic symptoms, particularly in patients sensitised to crustaceans. Current legislation does not enforce producers to include insects in the list of allergenic ingredients. Food allergenicity risk assessment (FARA) is still at its infancy, and the debate on the need to define allergen thresholds is open. In this paper, we aimed at applying the concepts of stochastic quantitative FARA to describe present and future scenarios of exposure to foods containing Tenebrio molitor, the yellow mealworm. According to our risk characterisation, mealworm-based food products represent a major risk for individuals allergic to crustaceans to develop symptoms after the consumption of a dose lower than a serving size. Moreover, other allergic consumers might be at risk. A correct labelling of insect containing foods would help safeguarding the health of EU allergic consumers. Quantitatively assessing the risk of allergenicity provides a clear description of the problem, facilitating the decisional process of the risk manager, supporting the implementation of effective allergen management procedures and limiting the phenomenon of uninformative precautionary labelling.

Short-term exposure to pollen and the risk of allergic and asthmatic manifestations: a systematic review and meta-analysis

BACKGROUND

Several studies have assessed effects of short-term exposure to pollen on allergic and asthmatic manifestations. The evidence is inconclusive, and no meta-analysis has been published.

OBJECTIVE

To synthesise the evidence on the relations between short-term pollen exposure and the risk of allergic and asthmatic manifestations.

METHODS

We performed a systematic literature search of PubMed and Scopus databases up to the end of August 2018. In addition, we reviewed the reference lists of relevant articles. Two authors independently evaluated the eligible articles and extracted relevant information in a structured form. We calculated summary effect estimates (EE) based on the study-specific ORs and regression coefficients (β) by applying both fixed-effects and random-effects models.

RESULTS

26 studies met the a priori eligibility criteria, and 12 of them provided sufficient information for the meta-analysis. The summary EE related to 10 grains per m³ increase in pollen exposure showed an 1% increase (EE 1.01, 95% CI 1.00 to 1.02) in the risk of lower respiratory symptoms and a 2% increase (EE 1.02, 95% CI 1.01 to 1.03) in the risk of any allergic or asthmatic symptom. Correspondingly, the risk of upper respiratory symptoms and ocular symptoms increased 7% (EE 1.07, 95% CI 1.04 to 1.09) and 11% (EE 1.11, 95% CI 1.05 to 1.17), respectively, in relation to such pollen exposure. Short-term exposure to pollen did not show any significant effect on daily lung function levels.

CONCLUSION

Our results provide new evidence that short-term pollen exposure significantly increases the risks of allergic and asthmatic symptoms.

SQ house dust mite sublingual immunotherapy for the treatment of adults with house dust mite-induced allergic rhinitis

Introduction: Allergic rhinitis (AR) is one of the most common chronic conditions affecting both children and adults. The house dust mites (HDM) account for a substantial part of the overall sources of allergens. In patients where allergen avoidance and symptom-relieving pharmacotherapy do not provide adequate disease control, specific allergen immunotherapy (AIT) is indicated. While subcutaneous injection (SCIT) is considered as a time-consuming and invasive treatment regimen, sublingual allergy immunotherapy (SLIT) appears as more convenient treatment strategy.Areas covered: This Drug Profile reviews the clinical data behind the development of the SQ HDM SLIT-tablet, including both the early studies and the pivotal studies, which formed the basis for regulatory approval in Europe, Japan, and the U.S.Expert opinion: The clinical trials behind the development of the SQ HDM-SLIT have demonstrated that the tablet provides a safe, well-tolerated and robust efficacy in the treatment of HDM-induced allergic rhinoconjunctivitis. Further, studies show that the SQ HDM SLIT-tablet is a cost-effective treatment option compared with SCIT.

A paper-based chemiluminescence immunoassay device for rapid and high-throughput detection of allergen-specific IgE

The fast and precise detection of potential allergen-specific immunoglobulin E (sIgE) is imperative for the diagnosis and appropriate treatment of allergic diseases. In this study, we have successfully fabricated a novel paper-based immunoassay device for the detection of sIgE in allergic diseases. We used Can f 1, one of the main dog allergens, as a model allergen to detect sIgE in human sera. To achieve excellent performance, the experimental parameters were optimized. Further, we extended this device for potential applications in the clinical diagnosis of allergic diseases: worthwhile clinical performance in the detection of allergens was achieved as compared to that achieved by commercial enzyme-linked immunosorbent assay (ELISA) kit. Therefore, it was proven that this strategy has the advantages of high-throughput, rapid, sensitive, and highly accurate detection of trace amounts of sIgEs. Furthermore, by simply changing the antigen and antibody, this device could be used for the high-throughput detection of other allergens, so as to achieve multiallergen detection and appropriate desensitization therapy, thereby making it promising in the determination of allergic diseases in clinics.

Birch pollen allergy in Europe

Birch and other related trees of the families Betulaceae and Fagaceae (alder, hazel, oak, hornbeam, chestnut, and beech) constitute the birch homologous group. This grouping is primarily based on the extensive IgE cross-reactivity of allergen homologs to the major birch allergen Bet v 1. Birch pollen is the most dominant tree pollen in Northern and Central Europe and is a major cause of allergic rhinitis and, possibly, asthma symptoms. Over the last few decades, levels of birch pollen have risen and the period of exposure has increased due to climate changes. Subsequently, the prevalence of birch pollen sensitization has also increased. The cross-reactivity and sequential pollen seasons within the birch homologous group create a prolonged symptomatic allergy period beyond birch pollen alone. Furthermore, many plant food allergens contain homologs to Bet v 1, meaning that the majority of patients with birch pollen allergy suffer from secondary pollen food syndrome (PFS). As a result, the negative impact on health-related quality of life (HRQoL) in patients allergic to birch pollen is significant. The purpose of this manuscript was to narratively review topics of interest such as taxonomy, cross-reactivity, prevalence, clinical relevance, PFS, and HRQoL with regard to birch pollen allergy from a European perspective.

[Relevance of nasal provocation testing in house dust mite allergy]

Patients with house dust mite allergies frequently exhibit very different symptoms to those allergic to other inhalant allergens. The frequency of comorbid allergic asthma in these patients is increased. Therefore, diagnosing patients with suspected house dust mite allergies can be difficult. It is important to distinguish between sensitization to an allergen and a clinically relevant allergy. Nasal provocation testing (NPT) is a reliable method to identify patients suitable for a causal treatment (specific immunotherapy). Position papers on methodology and interpretation of NPT data are available. Skin prick and allergen-specific IgE tests reveal a reasonable correlation with NPT results, although this is inexact to some extent. Performance of NPT in patients with suspected house dust mite allergy is important in individuals with questionable symptoms and unclear skin and blood test results, particularly prior to initiation of allergen immunotherapy.

BSACI guideline for the diagnosis and management of allergic and non-allergic rhinitis (Revised Edition 2017; First edition 2007)

This is an updated guideline for the diagnosis and management of allergic and non-allergic rhinitis, first published in 2007. It was produced by the Standards of Care Committee of the British Society of Allergy and Clinical Immunology, using accredited methods. Allergic rhinitis is common and affects 10-15% of children and 26% of adults in the UK, it affects quality of life, school and work attendance, and is a risk factor for development of asthma. Allergic rhinitis is diagnosed by history and examination, supported by specific allergy tests. Topical nasal corticosteroids are the treatment of choice for moderate to severe disease. Combination therapy with intranasal corticosteroid plus intranasal antihistamine is more effective than either alone and provides second line treatment for those with rhinitis poorly controlled on monotherapy. Immunotherapy is highly effective when the specific allergen is the responsible driver for the symptoms. Treatment of rhinitis is associated with benefits for asthma. Non-allergic rhinitis also is a risk factor for the development of asthma and may be eosinophilic and steroid-responsive or neurogenic and non- inflammatory. Non-allergic rhinitis may be a presenting complaint for systemic disorders such as granulomatous or eosinophilic polyangiitis, and sarcoidoisis. Infective rhinitis can be caused by viruses, and less commonly by bacteria, fungi and protozoa.

Stepwise approach towards adoption of allergen immunotherapy for allergic rhinitis and asthma patients in daily practice in Belgium: a BelSACI-Abeforcal-EUFOREA statement

Allergic rhinitis (AR) affects 23–30% of the European population with equal prevalence reported in Belgium. Despite guidelines on the correct use of effective treatment, up to 40% of AR patients remain uncontrolled. Allergen immunotherapy (AIT) has been shown to improve the level of control up to 84% of patients being controlled by AIT. Recently, new guidelines for AIT have been published, supporting the clinical evidence for effectiveness of various subcutaneous and sublingual products for AIT in patients who are allergic to airborne allergens. AIT in AR patients not only reduces nasal and/or ocular symptoms but also induces tolerance and has preventive potential. Adoption of AIT into daily clinical practice in Belgium and other European countries is hampered primarily by reimbursement issues of each of the single products but also by several patient- and physician-related factors. Patients need to be better informed about the effectiveness of AIT and the different routes of administration of AIT. Physicians dealing with AR patients should inform patients on tolerance-inducing effects of AIT and are in the need of a harmonized and practical guide that supports them in selecting eligible patients for AIT, in choosing evidence-based AIT products and in following treatment protocols with proven efficacy. Therefore, a stepwise and holistic approach is needed for better adoption of AIT in the real-life setting in Belgium.

Atopic diseases and type I sensitization from adolescence to adulthood in an unselected population (TOACS) with focus on predictors for allergic rhinitis

BACKGROUND

While much is known on childhood atopic diseases, knowledge about persistence of atopic diseases from childhood to adulthood is limited. We therefore aimed to study the clinical course of atopic diseases and type I sensitization prospectively in an unselected cohort of adolescents followed into adulthood.

METHODS

A cohort of unselected 8th-grade school children (mean age 14 years) established in 1995 and followed up in 2010 were evaluated with questionnaire, clinical examination, skin prick tests and measurements of specific IgE.

RESULTS

The lifetime prevalence of atopic diseases was high and increased significantly from adolescence (31%) to adulthood (57%); particularly allergic rhinitis increased with an incidence rate of 17.5/1000 person-years. Childhood predictors for adult allergic rhinitis were atopic dermatitis, asthma and asymptomatic sensitization to pollen and house dust mite. Among those with asymptomatic sensitization in adolescence, 53%-78% developed allergic rhinitis in adulthood. Furthermore, type I sensitization increased significantly from adolescence to adulthood mostly due to increased sensitization to pollen. Type I sensitization was found mainly in those with allergic rhinitis. A high number of adults had oral allergy symptoms due to the high number of birch pollen allergic individuals.

CONCLUSION

Persistence of atopic diseases in adulthood is common, and a high proportion of the adult population is sensitized giving a high prevalence of allergic rhinitis. Many with asymptomatic sensitization in adolescence will develop allergic rhinitis in adult life. The focus should be on prevention of atopic diseases and sensitization already in childhood.

Chronological changes in rhinitis symptoms present in school-aged children with allergic sensitization

Introduction

It is difficult to accurately predict the natural course of allergic rhinitis (AR), because it is affected by a wide variety of environmental influences, as well as genetic predisposition. Considering the high prevalence of allergic rhinitis in children and adolescents, caregivers should be given appropriate information regarding the disease course. This study aimed to understand the prognosis of allergic rhinitis by examining the relationship between allergic sensitization and rhinitis symptoms during this developmental period.

Methods

This cross-sectional study included 1069 children aged 9–16 years from the Korean International Study of Asthma and Allergies in Childhood Survey database who had completed health questionnaires, and for whom skin prick test results were available. Data were collected during May 2016. The distribution of sensitization and allergic symptoms was compared by age groups (elementary, middle, and high school). Data were analyzed using linear-by-linear analysis.

Results

Sensitization to at least one tested allergen differed by age (59.2%, 58.3%, 68.2%, in elementary, middle, and high school students, respectively; p = 0.025), and seasonal allergen sensitization (35.0%, 37.1%, 53.9%, respectively) increased with age (p < 0.001). Conversely, the proportion of rhinitis symptoms among sensitized children decreased as age increased (58.80%, 52.90%, 49.70%, respectively; p = 0.047). However, the rate of non-allergic rhinitis was age-independent.

Conclusion

With increasing age during childhood and adolescence, symptomatic allergic rhinitis decreases; thus, subclinical allergic rhinitis increases. This suggests that the symptoms of later-sensitized children are less clearly manifested, or that the symptoms reduce as previously sensitized children mature. This should be clarified further in a longitudinal study.

Group 2 Innate Lymphoid Cells in Pulmonary Immunity and Tissue Homeostasis

Group 2 innate lymphoid cells (ILC2) represent an evolutionary rather old but only recently identified member of the family of innate lymphoid cells and have received much attention since their detailed description in 2010. They can orchestrate innate as well as adaptive immune responses as they interact with and influence several immune and non-immune cell populations. Moreover, ILC2 are able to rapidly secrete large amounts of type 2 cytokines that can contribute to protective but also detrimental host immune responses depending on timing, location, and physiological context. Interestingly, ILC2, despite their scarcity, are the dominant innate lymphoid cell population in the lung, indicating a key role as first responders and amplifiers upon immune challenge at this site. In addition, the recently described tissue residency of ILC2 further underlines the importance of their respective microenvironment. In this review, we provide an overview of lung physiology including a description of the most prominent pulmonary resident cells together with a review of known and potential ILC2 interactions within this unique environment. We will further outline recent observations regarding pulmonary ILC2 during immune challenge including respiratory infections and discuss different models and approaches to study ILC2 biology in the lung.

Relationships between aeroallergen levels and hospital admissions for asthma in the Brussels-Capital Region: a daily time series analysis

BACKGROUND

Outdoor pollen grain and fungal spore concentrations have been associated with severe asthma exacerbations at the population level. The specific impact of each taxon and the concomitant effect of air pollution on these symptoms have, however, still to be better characterized. This study aimed to investigate the short-term associations between ambient concentrations of various aeroallergens and hospitalizations related to asthma in the Brussels-Capital Region (Belgium), an area recording especially high rates of admissions.

METHODS

Based on administrative records of asthma hospitalizations and regular monitoring of 11 tree/herbaceous pollen taxa and 2 fungal spore taxa, daily time series analyses covering the 2008-2013 period were performed. Effects up to 6 days after exposure were captured by combining quasi-Poisson regression with distributed lag models, adjusting for seasonal and long-term trends, day of the week, public holidays, mean temperature and relative humidity. Effect modification by age and air pollution (PM, NO₂, O₃) was tested.

RESULTS

A significant increase in asthma hospitalizations was observed for an interquartile range increase in grass (5.9%, 95% CI: 0.0, 12.0), birch (3.2%, 95% CI: 1.1, 5.3) and hornbeam (0.7%, 95% CI: 0.2, 1.3) pollen concentrations. For several taxa including grasses, an age modification effect was notable, the hospitalization risk tending to be higher in individuals younger than 60 years. Air pollutants impacted the relationships too: the risk appeared to be stronger for grass and birch pollen concentrations in case of high PM₁₀ and O₃ concentrations respectively.

CONCLUSIONS

These findings suggest that airborne grass, birch and hornbeam pollen are associated with severe asthma exacerbations in the Brussels region. These compounds appear to act in synergy with air pollution and to more specifically affect young and intermediate age groups. Most of these life-threatening events could theoretically be prevented with improved disease diagnosis/management and targeted communication actions.

The STOPPA Twin Study Explains the Exhaled Nitric Oxide and Asthma Link by Genetics and Sensitization

BACKGROUND

The link between asthma and exhaled nitric oxide (FENO) is not completely understood. The aim of this study was to estimate the association between FENO and asthma, taking genetics, sensitization, and inhaled corticosteroids (ICS) into account.

METHODS

A total of 681 twins (53% monozygotic [MZ] and 47% dizygotic [DZ]) from the population-based STOPPA study (mean age 12.6 years) were recruited and information on FENO (parts per billion), parental report of current asthma, sensitization to airborne allergens (Phadiatop; IgE ≥0.35 kUA/l), and ICS-treatment was collected. We estimated the association between FENO and asthma, sensitization, and ICS in all twins and within pairs (DZ and MZ) to address shared genetic and environmental factors. Linear regression of log-transformed FENO was used and results presented as exponentiated regression coefficients (exp[β]), with 95% confidence interval (CI).

RESULTS

We found an association between asthma and FENO in all twins, exp(β) 1.31 [1.11, 1.54]. In within-pairs analysis, the association was stronger within DZ pairs discordant for FENO, exp(β) 1.50 [1.19, 1.89], compared to MZ pairs, exp(β) 1.07 [0.84, 1.37], p = .049. There was no difference in FENO in non-sensitized children with asthma, compared to children with neither asthma nor sensitization, exp(β) 0.89 [0.77, 1.03]. However, increased FENO was associated with sensitization, exp(β) 1.48 [1.30, 1.69], and with sensitization together with asthma, exp(β) 1.98 [1.57, 2.51], in all twins and within DZ pairs discordant for FENO, but not in MZ pairs. The FENO asthma association remained in DZ pairs without regular ICS-treatment.

CONCLUSIONS

The association between FENO and asthma is explained by genetics and sensitization.

Symptomatology Patterns in Children with Allergic Rhinitis

Background

Although allergic rhinitis (AR) is recognized as a growing global health disease with considerable importance for patients’ lives, especially among children and adolescents, there is a lack of population studies concerning symptomatology patterns of the disease. The present study aimed to explore symptoms prevalence among school-aged children, to detect any correlation between allergen sensitivities with symptomatology patterns, and, finally, to evaluate the association of the sensitivity grade score with symptoms severity or seasonality.

Material/Methods

This was a cross-sectional, observational study in a childhood population. The first stage included recruitment of children and parental-completed questionnaires. The second stage included skin-prick tests for the most common allergens. Severity of symptoms was self-evaluated using a scale that ranged from “0” (no symptoms), “1” (mild), and “2” (moderate-to-severe). AR was classified as seasonal (SAR) or perennial (PAR).

Results

The most frequent symptoms were reported for nasal obstruction, sneezing, and rhinorrhea. All nasal symptoms were significantly more profound among children with HDM sensitivity. However, more symptoms, not only nasal, but also ocular and general ones, were detected among patients with grass pollen sensitivity. Patients with PAR reported more severe symptoms. SAR was associated with mild disease. Finally, the sensitivity grade score was significantly correlated with symptom severity.

Conclusions

Our results suggest that allergen sensitivity may be correlated with symptomatology patterns among children who have allergic rhinitis.

Urbanity as a determinant of exposure to grass pollen in Helsinki Metropolitan area, Finland

Little is known about the levels of exposure to grass pollen in urban environments. We assessed the spatio-temporal variation of grass pollen concentrations and the role of urbanity as a determinant of grass pollen exposure in the Helsinki Metropolitan area. We monitored grass pollen concentrations in 2013 at 16 sites during the peak pollen season by using rotorod-type samplers at the breathing height. The sites were in the cities of Helsinki and Espoo, Finland, and formed city-specific lines that represented urban-rural gradient. The monitoring sites were both visually and based on land use data ranked as high to low (graded 1 to 8) pollen area. The lowest grass pollen concentrations were observed in the most urban sites compared to the least urban sites (mean 3.6 vs. 6.8 grains/m³ in Helsinki; P<0.0001, and 5.2 vs. 87.5 grains/m³ in Espoo; P<0.0001). Significant differences were observed between concentrations measured in morning periods compared to afternoon periods (4.9 vs. 5.4 in Helsinki, P = 0.0186, and 21.8 vs. 67.1 in Espoo, P = 0.0004). The mean pollen concentration increased with decreasing urbanity both in Helsinki (0.59 grains/m³ per urbanity rank, 95% CI 0.25–0.93) and Espoo (8.42, 6.23–10.61). Pollen concentrations were highest in the afternoons and they were related to the ambient temperature. Urbanity was a strong and significant determinant of pollen exposure in two Finnish cities. Pollen exposure can periodically reach such high levels even in the most urban environments that can cause allergic reactions among individuals with allergies.

Natural Evolution of IgE Responses to Mite Allergens and Relationship to Progression of Allergic Disease: a Review

PURPOSE OF REVIEW

Allergenic molecules of the house dust mite (HDM) are crucially important indoor allergens, contributing to allergic rhinitis and asthma around the globe. In the past years, recombinant molecules for diagnostics opened new pathways to investigate individual sensitization profiles and new chances for the prevention and treatment of HDM allergy. This review summarizes the latest findings on the evolution of IgE responses towards mite allergens.

RECENT FINDINGS

Several cross-sectional and longitudinal studies confirmed the role of Der p 1 and Der p 2 as major allergenic proteins of the HDM. A newly identified player is the major allergen Der p 23. Apart from identifying the early sensitization towards this molecule as a risk factor for asthma in school age, a recent longitudinal study described sensitization patterns showing that the production of IgE usually starts towards a group of initiator proteins and may stay monomolecular or expand to an oligo- or even polymolecular stage. This phenomenon also correlates to clinical symptoms. A relation between a broad sensitization pattern and symptom severity has also been shown cross-sectionally. Individual sensitization profiles towards HDM allergens provide important information to evaluate a patient's current stage and risk for clinical symptoms. This knowledge paves the way for an early and adequate prevention and/or treatment.

Sensitization patterns and minimum screening panels for aeroallergens in self-reported allergic rhinitis in China

Optimization of skin prick test (SPT) panels, especially in view of significant differences in sensitizations patterns within different geographical areas, is an unmet need within China. Our aim was to assess the patterns and clinical relevance of aeroallergen sensitizations in allergic rhinitis (AR) and define the minimal battery of SPT allergens, classified according to the Köppen-Geiger climate map. Overall, 7148 subjects with self-reported AR completed a standard questionnaire and were assessed for sensitization to relevant allergens by SPT. 6340 (88.7%) patients had at least one positive skin prick reaction, and demonstrated unique sensitization patterns by stratification with age, gender, and geographic region. Sensitization to house dust mites (HDM) was highest in south China, whereas the three most prevalent aeroallergens were mugwort, ragweed and dandelion pollen in north-west China. Higher sensitization rates and multiple sensitizations were associated with AR comorbidities. Eight allergens (Der f, mugwort, Blatella, hazel, goosefoot, Penicillium notatum, animal dander and Der p) allowed identification >96% of sensitized subjects in central China. Differences in optimal panels were observed between regions, with five to six allergens being sufficient for north-east, north-west and south China. These SPT panels may provide a cost-effective tool for screening sensitized patients in China.

Major allergen content consistency of SQ house dust mite sublingual immunotherapy tablets and relevance across geographic regions

BACKGROUND

Consistency in composition and potency, particularly regarding major allergens, is crucial for the quality of extracts for allergen immunotherapy.

OBJECTIVE

To characterize the major allergen composition of house dust mite (HDM) extracts commercially available in the United States and the SQ HDM sublingual immunotherapy (SLIT) tablet, and to relate the composition to patient sensitization patterns.

METHODS

Der 1/Der 2 ratios were determined in 10,000- and 30,000-AU/mL HDM extracts from 5 US companies and the SQ HDM SLIT-tablet. Allergen content was analyzed by enzyme-linked immunosorbent assay and compared with an in-house reference. Sensitivity toward Der p 1, Der p 2, and Der p 10 was determined in serum from randomly selected subgroups of 220 individuals from North American and European SQ HDM SLIT-tablet trials.

RESULTS

Mean Der 1/Der 2 ratios in US HDM extracts ranged from 0.4 to 20.5. For the SQ HDM SLIT-tablet (20 batches), variability did not exceed 12% regarding content of Der f 1 (SD, 11.9%; 95% confidence interval [CI], 0.94-1.06), Der p 1 (SD, 6.1%; 95% CI, 0.97-1.03), and combined Der 2 allergen (SD, 6.4%; 95% CI, 0.97-1.03), indicating a consistent Der 1/Der 2 ratio. High allergen sensitivity frequencies toward Der p 1 and Der p 2 were observed regardless of geographic region. Efficacy of the SQ HDM SLIT-tablet has been demonstrated in 5 clinical trials.

CONCLUSION

The SQ HDM SLIT-tablet has efficacy potential for a broad range of patients because it includes a consistent 1:1 ratio of the 2 major HDM allergens to which individuals were most frequently sensitized across geographic regions. Efficacy has been demonstrated.

Costs of perennial allergic rhinitis and allergic asthma increase with severity and poor disease control

BACKGROUND

Perennial allergic rhinitis (PAR) represents a global and public health problem, due to its prevalence, morbidity, and impact on the quality of life. PAR is frequently associated with allergic asthma (AA). Costs of PAR with or without AA are poorly documented.

OBJECTIVE

Our study aimed to detail medical resource utilization (MRU) and related direct cost for PAR, with or without concomitant AA, in France.

METHODS

Using Electronic Health Records (EHRs), we identified in 2010 two cohorts of PAR patients, based on General Practitioners' diagnoses and prescribing data, with and without concomitant AA. For each patient, the EHRs were linked to corresponding claims data with MRU and costs during years 2011 to 2013. Predefined subgroup analyses were performed according to severity of PAR and level of AA control.

RESULTS

The median annual cost reimbursed by social security system for a patient with PAR, and no AA was 159€ in 2013. This varied from 111€ to 188€ depending on PAR severity. For patients with PAR and concomitant AA, the median annual cost varied between 266€ and 375€, and drug treatment accounted for 42-55% of the costs, depending on asthma control.

CONCLUSION

This study linking diagnoses from EHRs to claims data collected valid information on PAR management, with or without concomitant AA, and on related costs. There was a clear increase in costs with severity of PAR and control of AA.

Charting novel allergens from date palm pollen (Phoenix sylvestris) using homology driven proteomics

Pollen grains from Phoenix sylvestris (date palm), a commonly cultivated tree in India has been found to cause severe allergic diseases in an increasing percentage of hypersensitive individuals. To unearth its allergenic components, pollen protein were profiled by two-dimensional gel electrophoresis followed by immunoblotting with date palm pollen sensitive patient sera. Allergens were identified by MALDI-TOF/TOF employing a layered proteomic approach combining conventional database dependent search and manual de novo sequencing followed by homology-based search as Phoenix sylvestris is unsequenced. Derivatization of tryptic peptides by acetylation has been demonstrated to differentiate the 'b' from the 'y' ions facilitating efficient de novo sequencing. Ten allergenic proteins were identified, out of which six showed homology with known allergens while others were reported for the first time. Amongst these, isoflavone reductase, beta-conglycinin, S-adenosyl methionine synthase, 1, 4 glucan synthase and beta-galactosidase were commonly reported as allergens from coconut pollen and presumably responsible for cross-reactivity. One of the allergens had IgE binding epitope recognized by its glycan moiety. The allergenic potency of date palm pollen has been demonstrated using in vitro tests. The identified allergens can be used to develop vaccines for immunotherapy against date palm pollen allergy.

THE SIGNIFICANCE OF THE STUDY

Identification of allergenic proteins from sources harboring them is essential in developing therapeutic interventions. This is the first comprehensive study on the identification of allergens from Phoenix sylvestris (date palm) pollen, one of the major aeroallergens in India using a proteomic approach. Proteomic methods are being increasingly used to identify allergens. However, since many of these proteins arise from species which are un-sequenced, it becomes difficult to interpret those using conventional proteomics. Date palm being an unsequenced species, the IgE-reactive proteins have been identified using a stratified proteomic workflow incorporating manual de novo sequencing and homology-based proteomics. This study also gives an insight into the presence of glycan nature of the IgE binding epitopes. Five proteins have been found to be common with coconut pollen allergens and presumably responsible for cross-reactivity. These can be used in diagnostics to differentiate patient cohorts allergic to both coconut and date palm pollen from true date palm pollen allergic subjects. This would also determine better specific immunotherapy regimes between the two cohorts. The allergens identified herein have potential towards vaccine development in date palm pollen allergy as well as in enriching the existing catalogue of allergenic proteins.

The impact of age on serum allergen-specific IgE to inhaled molecular components

BACKGROUND

Respiratory allergy is characterised by an IgE-mediated reaction. The immune system functions, including IgE production, progressively decline over time, such as growing up and ageing. Molecular-based allergy diagnostic defines sensitisation profile. This study aimed to evaluate the impact of age on serum allergen-specific IgE to molecular component levels in a large sample of subjects.

METHODS

Serum IgE to: Phl p1, Bet v1, Ole e1, Cup a1, Par j2, Can f1, Der p2, and Fel d1 were assessed by ISAC method. Sera from 2788 patients, 1230 males (44.1%) and 1558 females (55.9%), median age 23 years (1st and 3rd quartiles: 9.7-49.7 years; age range: 1 month-103 years) were analysed.

RESULTS

The number of positive tests (i.e. sensitisation) tended to increase between birth and school-age till young adulthood and then decreased (p<0.0001) with the exception of Fel d 1 (p=0.14). A similar age-dependent trend was observed considering the levels of each allergen components: the levels of each allergen component, with the exception of Fel d 1, tended to increase till early adulthood and then to decrease reaching the lowest levels in the elderly.

CONCLUSIONS

Allergen-specific IgE production to inhaled molecular components trend to reduce with ageing, but with differences between allergens. This phenomenon should be adequately evaluated managing allergic patients.

Allergic sensitization prevalence in a children and adolescent population of northeastern Greece region

OBJECTIVES

To evaluate the prevalence of allergic sensitization in a childhood and adolescent population, to explore age- and gender-specific variations and finally to discover co-sensitivities among allergens.

METHODS

A two-stage cross-sectional survey among school-aged children. The two stages of the study involved enrollment of schools and then skin prick testing (SPT) within schools. A total of 675 school children were included in the study. Of those, 231 were diagnosed with allergic rhinitis (AR), according to the medical history as provided by parental-completed questionnaires and positive SPT results. The antigen panel consisted of common allergens and more specifically house dust mites-HDM (Dermatophagoides farinae and Dermatophagoides pteronyssinus), grass mix, trees (olive, cypress and pine), weeds (Parietaria spp.), cat and dog epithelium and moulds (Alternaria spp., Cladosporium spp.). The SPT sensitivity was graded according to SPT-USA Standards.

RESULTS

The overall prevalence rate of AR was 34.22%. In total, 93 school children (40.3%) were mono- and 138 (59.7%) were poly-sensitized. Overall, the most prevalent sensitizations in decreasing order were to HDM (59.74%), to grasses (48.9%), to Alternaria (34.6%) and to olive (14.71%). There were no age- and sex-specific differences, except for Alternaria mould that showed a significant prevalence among primary school-aged children and predominance in the female gender, by contrast to grass pollen allergy that was predominant to males. A 32% of SPT-positive individuals were not aware of their allergy, with no statistically significant differences between ages. Co-sensitivities were detected for grass pollens and pine and olive trees, for Alternaria and Cladosporium moulds, for cypress and pine trees, and finally for dog and cat danders.

CONCLUSIONS

Given data among school-aged children should be a baseline from which to monitor disease trends and is considered important for the optimal management of AR patients.

Molecular, Structural and Immunological Characterization of Der p 18, a Chitinase-Like House Dust Mite Allergen

Background

The house dust mite (HDM) allergen Der p 18 belongs to the glycoside hydrolase family 18 chitinases. The relevance of Der p 18 for house dust mite allergic patients has only been partly investigated.

Objective

To perform a detailed characterization of Der p 18 on a molecular, structural and immunological level.

Methods

Der p 18 was expressed in E. coli, purified to homogeneity, tested for chitin-binding activity and its secondary structure was analyzed by circular dichroism. Der p 18-specific IgG antibodies were produced in rabbits to localize the allergen in mites using immunogold electron microscopy and to search for cross-reactive allergens in other allergen sources (i.e. mites, crustacea, mollusca and insects). IgE reactivity of rDer p 18 was tested with sera from clinically well characterized HDM-allergic patients (n = 98) and its allergenic activity was analyzed in basophil activation experiments.

Results

Recombinant Der p 18 was expressed and purified as a folded, biologically active protein. It shows weak chitin-binding activity and partial cross-reactivity with Der f 18 from D. farinae but not with proteins from the other tested allergen sources. The allergen was mainly localized in the peritrophic matrix of the HDM gut and to a lower extent in fecal pellets. Der p 18 reacted with IgE from 10% of mite allergic patients from Austria and showed allergenic activity when tested for basophil activation in Der p 18-sensitized patients.

Conclusion

Der p 18 is a rather genus-specific minor allergen with weak chitin-binding activity but exhibits allergenic activity and therefore should be included in diagnostic test panels for HDM allergy.

A rhinitis phenotype associated with increased development of bronchial hyperresponsiveness and asthma in children

BACKGROUND

Allergic rhinitis (AR) has a wide range of clinical features and may be accompanied by comorbid allergic diseases.

OBJECTIVE

To identify rhinitis phenotypes in school aged children and to predict the prognosis for developing bronchial hyperresponsiveness (BHR) and asthma.

METHODS

This prospective follow-up study involved schoolchildren from the Children's Health and Environment Research cohort with current rhinitis, which was defined based on parental-reported, physician-diagnosed rhinitis and symptoms of rhinitis in the previous 12 months. All participants were followed up at 2 and 4 years later. Rhinitis clusters were identified by latent class analysis that used demographic, clinical, and environmental variables.

RESULTS

In 512 eligible children (age range, 6-8 years), 4 rhinitis phenotypes were identified: cluster 1 (25% of children) was associated with nonatopy and a low socioeconomic status; cluster 2 (36%) was associated with a high-atopic burden but normal lung function; cluster 3 (22%) was associated with a high-atopic burden and impaired lung function; and cluster 4 (17%) was associated with low atopy and a high socioeconomic status. Cluster 3 was associated with the highest total serum IgE levels and blood eosinophil percentages at enrollment and the highest incidence of new cases of BHR (P = .04) and asthma symptoms (P = .005) during follow-up.

CONCLUSION

The rhinitis cluster of schoolchildren with atopy and impaired lung function is associated with allergic march. This identification of distinct rhinitis phenotypes in affected children may help to prevent allergic march in children with rhinitis.

Fine-Scale Exposure to Allergenic Pollen in the Urban Environment: Evaluation of Land Use Regression Approach

BACKGROUND

Despite the recent developments in physically and chemically based analysis of atmospheric particles, no models exist for resolving the spatial variability of pollen concentration at urban scale.

OBJECTIVES

We developed a land use regression (LUR) approach for predicting spatial fine-scale allergenic pollen concentrations in the Helsinki metropolitan area, Finland, and evaluated the performance of the models against available empirical data.

METHODS

We used grass pollen data monitored at 16 sites in an urban area during the peak pollen season and geospatial environmental data. The main statistical method was generalized linear model (GLM).

RESULTS

GLM-based LURs explained 79% of the spatial variation in the grass pollen data based on all samples, and 47% of the variation when samples from two sites with very high concentrations were excluded. In model evaluation, prediction errors ranged from 6% to 26% of the observed range of grass pollen concentrations. Our findings support the use of geospatial data-based statistical models to predict the spatial variation of allergenic grass pollen concentrations at intra-urban scales. A remote sensing-based vegetation index was the strongest predictor of pollen concentrations for exposure assessments at local scales.

CONCLUSIONS

The LUR approach provides new opportunities to estimate the relations between environmental determinants and allergenic pollen concentration in human-modified environments at fine spatial scales. This approach could potentially be applied to estimate retrospectively pollen concentrations to be used for long-term exposure assessments.

CITATION

Hjort J, Hugg TT, Antikainen H, Rusanen J, Sofiev M, Kukkonen J, Jaakkola MS, Jaakkola JJ. 2016. Fine-scale exposure to allergenic pollen in the urban environment: evaluation of land use regression approach. Environ Health Perspect 124:619-626; http://dx.doi.org/10.1289/ehp.1509761.

Mining Novel Allergens from Coconut Pollen Employing Manual De Novo Sequencing and Homology-Driven Proteomics

Coconut pollen, one of the major palm pollen grains is an important constituent among vectors of inhalant allergens in India and a major sensitizer for respiratory allergy in susceptible patients. To gain insight into its allergenic components, pollen proteins were analyzed by two-dimensional electrophoresis, immunoblotted with coconut pollen sensitive patient sera, followed by mass spectrometry of IgE reactive proteins. Coconut being largely unsequenced, a proteomic workflow has been devised that combines the conventional database-dependent analysis of tandem mass spectral data and manual de novo sequencing followed by a homology-based search for identifying the allergenic proteins. N-terminal acetylation helped to distinguish "b" ions from others, facilitating reliable sequencing. This led to the identification of 12 allergenic proteins. Cluster analysis with individual patient sera recognized vicilin-like protein as a major allergen, which was purified to assess its in vitro allergenicity and then partially sequenced. Other IgE-sensitive spots showed significant homology with well-known allergenic proteins such as 11S globulin, enolase, and isoflavone reductase along with a few which are reported as novel allergens. The allergens identified can be used as potential candidates to develop hypoallergenic vaccines, to design specific immunotherapy trials, and to enrich the repertoire of existing IgE reactive proteins.

Risk factors for chronic rhinosinusitis

PURPOSE OF REVIEW

To review the recent literature on risk factors for chronic rhinosinusitis (CRS) with an emphasis on genetic, comorbid diseases and environmental factors associated with CRS. Through identifying potential risk factors for CRS, we aim to glean insights into the underlying pathogenic mechanisms essential for developing effective therapeutic strategies.

RECENT FINDINGS

Recent findings demonstrate that genetics and comorbid medical conditions including airway diseases, gastroesophageal reflux disease, inflammatory and autoimmune diseases, and various demographic and environmental factors are associated with having a CRS diagnosis. Limitations of current studies include variable application of disease definitions, lack of prospective longitudinal studies and a disproportionate focus on tertiary care populations.

SUMMARY

CRS has a broad spectrum of associations ranging from genetics to comorbid diseases and environmental factors. These predisposing factors may provide valuable information for possible designing of therapeutic and preventive interventions. However, to better understand whether these associations cause CRS, further studies are needed to independently replicate findings, establish temporal relationships between exposure and disease onset, evaluate the influence of exposure dose on disease severity, and to understand the biological effects of these risk factors in the context of CRS.