Geographical variation in the prevalence of sensitization to common aeroallergens in adults: the GA(2) LEN survey

Allergen Sensitization and Its Association With Allergic Diseases in the Korean Population: Results From the 2019 Korea National Health and Nutrition Examination Survey

PURPOSE

Allergen exposure is the most potent factor in allergen sensitization, which affects the exacerbation and severity of allergic diseases. Due to industrialization and climate change, the pattern of allergen sensitization has changed over time, and the incidence of allergic diseases has also increased. This study investigated the status of allergen sensitization in the Korean population and its effects on allergic diseases.

METHODS

A total of 2,386 participants aged ≥ 10 years, who underwent 7 specific immunoglobulin E tests for aeroallergens (Dermatophagoides farinae [Der f], dog dander, cat epithelium, birch, oak, Japanese hop, and ragweed), were selected among the participants of the 2019 Korean National Health and Nutrition Examination Survey. We compared the demographic characteristics, combined allergic diseases, and sinusitis symptoms between the atopic and non-atopic groups.

RESULTS

The prevalence of allergen sensitization in the general Korean population was 45%, and Der f was the most frequent cause of sensitization (39.9%). The prevalence of sensitization to indoor allergens was highest among teenagers and those belonging to the 20- to 29-year age group (P < 0.001). In contrast, there was a high prevalence of sensitization to outdoor allergens among individuals belonging to the age group of 60-69 years. The prevalence of atopic dermatitis (odds ratio [OR], 2.559; 95% confidence interval [CI], 1.689-3.878), allergic rhinitis (OR, 3.075; 95% CI, 2.426-3.897), and otitis media (OR, 1.481; 95% CI, 1.092-2.007) significantly increased by allergen sensitization. Patients with allergen sensitization were more likely to experience the symptoms of rhinitis and sinusitis.

CONCLUSIONS

The study findings confirmed that allergen sensitization occurs in approximately half of the general Korean population and affects the prevalence and symptoms of allergic diseases. This suggests that active allergy tests and diagnosis of allergic diseases are necessary in Koreans.

Atopy and allergic diseases among college students at a Saudi Public University

Background

Despite its significant prevalence worldwide, atopy and allergic diseases continue to need more studies, with a need for published articles describing the prevalence of atopy and allergic diseases in Saudi society. The study aimed to determine the prevalence of atopic dermatitis diseases among college students at Imam Mohammad Ibn Saud Islamic University.

Methods

The Cross-sectional study was conducted in Saudi Arabia among college students at Imam Mohammed bin Saud Islamic University in Riyadh based on self-report Asthma and Allergies questionnaires (ISSAC questionnaire, atopic dermatitis part).

Results

Seven hundred ninety-seven (797) students from 11 colleges participated in the study. About half (47.6%) aged between 21 and 24, and 73.7% were females. More than one-third (34.8%) had atopic dermatitis during the last six months, while 30.7% of the participants reported having itchy rash in the past 12 months, and 33.8% were diagnosed with eczema in any life interval. Age is not one of the significant factors affecting the prevalence of atopic dermatitis. However, the prevalence of atopic dermatitis slightly increases with age (P = 0.062). Atopic dermatitis was significantly higher among female students (39.7%) than 21.0% among male students (P = 0.000). College level nor GPA had no significant impact on the prevalence of atopic dermatitis (P = 0.238 and 0.884, respectively).

Conclusion

Imam Mohammad Ibn Saud Islamic University students have a high prevalence of atopic dermatitis, which may indicate a higher prevalence of allergens. Females and older participants were more liable to reported atopic dermatitis.

Outdoor Alternaria and Cladosporium spores and acute asthma

BACKGROUND

Outdoor Alternaria and Cladosporium spores are ubiquitous. Few studies have assessed their impact on asthma hospitalizations providing conflicting results, mainly focused on vulnerable paediatric populations. We aimed to study the impact of outdoor Alternaria and Cladosporium concentrations on acute hospitalizations in the Capital Region of Denmark.

METHODS

This is a bi-directional case-crossover study with 26 years of national registry data at individual level on acute asthma hospitalizations and daily average data on Alternaria and Cladosporium, pollen (Artemisia, Poaceae), maximal temperature, and air pollution. Conditional logistic regression models were applied to assess the associations. Concentration quartiles at lag 0 were used for categorizing the exposure.

RESULTS

For lags 0-2, the odds of hospitalization were significantly higher for both Alternaria and Cladosporium at concentration quartile 2-4 compared with quartile 1. When stratified for age and sex, odds of hospitalization at Alternaria quartiles 2-4 were significantly higher in males below 40 years at lag 0-2, and at lag 0 in females (18-30 years), while quartiles 2-4 of Cladosporium concentrations were associated with significantly higher odds in boys (0-17 years) at lag 1-3, males (18-39 years) at lag 0-1, females (18-39 years) at lag 1-2, males (40-64 years) at lag 0-2, females (40-64 years) at lag 0 and 2, in seniors (65+ years) male at lag 1-2 and female at lag 0-1. The effect of Alternaria varied significantly depending on the level of Cladosporium (p < .0001).

CONCLUSION

Ambient Alternaria and Cladosporium spores can induce asthma hospitalizations. Males are more susceptible to both genera. Males and females under age 40 years are more susceptible to Alternaria.

Current state and prospects of artificial intelligence in allergy

The field of medicine is witnessing an exponential growth of interest in artificial intelligence (AI), which enables new research questions and the analysis of larger and new types of data. Nevertheless, applications that go beyond proof of concepts and deliver clinical value remain rare, especially in the field of allergy. This narrative review provides a fundamental understanding of the core concepts of AI and critically discusses its limitations and open challenges, such as data availability and bias, along with potential directions to surmount them. We provide a conceptual framework to structure AI applications within this field and discuss forefront case examples. Most of these applications of AI and machine learning in allergy concern supervised learning and unsupervised clustering, with a strong emphasis on diagnosis and subtyping. A perspective is shared on guidelines for good AI practice to guide readers in applying it effectively and safely, along with prospects of field advancement and initiatives to increase clinical impact. We anticipate that AI can further deepen our knowledge of disease mechanisms and contribute to precision medicine in allergy.

Microscale pollen release and dispersal patterns in flowering grass populations

Characterizing pollen release and dispersion processes is fundamental for knowledge advancement in ecological, agricultural and public health disciplines. Understanding pollen dispersion from grass communities is especially relevant due to their high species-specific allergenicity and heterogeneously distributed source areas. Here, we aimed to address questions concerning fine level heterogeneity in grass pollen release and dispersion processes, with a focus on characterizing the taxonomic composition of airborne grass pollen over the grass flowering season using eDNA and molecular ecology methods. High resolution grass pollen concentrations were compared between three microscale sites (<300 m apart) in a rural area in Worcestershire, UK. The grass pollen was modelled with local meteorology in a MANOVA (Multivariate ANOVA) approach to investigate factors relevant to pollen release and dispersion. Simultaneously, airborne pollen was sequenced using Illumina MySeq for metabarcoding, analysed against a reference database with all UK grasses using the R packages DADA2 and phyloseq to calculate Shannon's Diversity Index (α-diversity). The flowering phenology of a local Festuca rubra population was observed. We found that grass pollen concentrations varied on a microscale level, likely attributed to local topography and the dispersion distance of pollen from flowering grasses in local source areas. Six genera (Agrostis, Alopecurus, Arrhenatherum, Holcus, Lolium and Poa) dominated the pollen season, comprising on average 77 % of the relative abundance of grass species reads. Temperature, solar radiation, relative humidity, turbulence and wind speeds were found to be relevant for grass pollen release and dispersion processes. An isolated flowering Festuca rubra population contributed almost 40 % of the relative pollen abundance adjacent to the nearby sampler, but only contributed 1 % to samplers situated 300 m away. This suggests that most emitted grass pollen has limited dispersion distance and our results show substantial variation in airborne grass species composition over short geographical scales.

Isolating the species element in grass pollen allergy: A review

Grass pollen is a leading cause of allergy in many countries, particularly Europe. Although many elements of grass pollen production and dispersal are quite well researched, gaps still remain around the grass species that are predominant in the air and which of those are most likely to trigger allergy. In this comprehensive review we isolate the species aspect in grass pollen allergy by exploring the interdisciplinary interdependencies between plant ecology, public health, aerobiology, reproductive phenology and molecular ecology. We further identify current research gaps and provide open ended questions and recommendations for future research in an effort to focus the research community to develop novel strategies to combat grass pollen allergy. We emphasise the role of separating temperate and subtropical grasses, identified through divergence in evolutionary history, climate adaptations and flowering times. However, allergen cross-reactivity and the degree of IgE connectivity in sufferers between the two groups remains an area of active research. The importance of future research to identify allergen homology through biomolecular similarity and the connection to species taxonomy and practical implications of this to allergenicity is further emphasised. We also discuss the relevance of eDNA and molecular ecological techniques (DNA metabarcoding, qPCR and ELISA) as important tools in quantifying the connection between the biosphere with the atmosphere. By gaining more understanding of the connection between species-specific atmospheric eDNA and flowering phenology we will further elucidate the importance of species in releasing grass pollen and allergens to the atmosphere and their individual role in grass pollen allergy.

Sensitization to Furry Animals in Patients with Suspected Allergic Disease in China: A Multicenter Study

PURPOSE

An objective of this study was to investigate the allergen sensitization characteristics of cat, dog and horse dander in patients with suspected allergic diseases in different geographical regions of Chinese mainland.

PATIENTS AND METHODS

We invited 2377 patients aged 0-86 years with suspected allergic diseases to participate in a cross-sectional survey in 11 provinces in China. Combined with the questionnaires and animal-specific IgE levels, we analyzed the epidemiological characteristics and risk factors of furry animal sensitization in different regions and populations of Chinese Mainland.

RESULTS

Among the 2377 patients with suspected allergic diseases, 14.9% were sensitized to cat dander, 9.3% to dog dander and 5.5% to horse dander. Animal allergens mainly cause low-level sensitization (class 1-3). There was a significant correlation between cat, dog and horse dander allergen sIgE, with correlation coefficients (rs) all greater than 0.750. The majority (46.5%) of sIgE-positive patients were sensitized to at least two animal allergens simultaneously. The prevalence of these animals all showed a trend of increasing first and then decreasing with age, and all reached the peak in young adolescence. As for the geographical factors, the sensitization rate of cats and dogs in Western was significantly higher than that in Eastern (cat: 18.4% vs 9.2%, dog: 11.6% vs 5.5%, all P < 0.001), however, no significant differences were found in horses. Aged ≤6 years, living in Western, and high animal allergen exposure elevated the risk of cat or dog sensitization. Living on a lower floor (aOR: 0.56) was a protective factor for horse sensitization.

CONCLUSION

In this representative sample of Chinese patients with suspected allergic diseases, there was an apparent geographic variation in sensitization to cats and dogs. Age factor and living in Western also had a significant impact on animal allergen sensitization rate.

Allergic sensitization pattern as a marker of bronchial hyperresponsiveness in allergic rhinitis patients living in temperate continental climate zone

BACKGROUND

Bronchial hyperresponsiveness (BHR) is a key feature of asthma, but it may also appear in allergic rhinitis. The type of allergen, as well as regional characteristics, play an important role in the development of BHR. The aim of our study was to analyze allergen sensitization patterns and the factors that affect BHR in allergic rhinitis patients living in temperate continental climate zone.

METHODS

This study retrospectively analyzed allergic rhinitis patients from Eastern Slovakia who underwent skin-prick tests to aeroallergens, spirometry, histamine and methacholine bronchial provocation tests for evaluation of lower airway symptoms. We analyzed the associations between BHR and the pattern of aeroallergen sensitization, lung function parameters, and the total IgE and eosinophil levels.

RESULTS

Out of 365 allergic rhinitis patients (age range 16-64 years), 114 showed BHR. Sensitization to house dust mites (HDMs) and grass were the most common. BHR was significantly associated with sensitization to dogs (odds ratio, OR = 2.15, 95% confidence interval, CI: 1.13-4.11) and Alternaria (OR = 2.15, 95% CI: 1.06-4.35); however, BHR did not show a relationship with HDMs sensitization. The levels of total IgE and eosinophils were higher in the BHR-positive group. Sensitization to more than six allergens significantly increased the probability of BHR (p < 0.01).

CONCLUSION

Dogs and Alternaria, but not HDMs, were the sensitizing agents most closely associated with BHR. High-grade sensitization and increased total IgE and eosinophil levels were characteristic clinical signs in BHR-positive allergic rhinitis patients in the temperate continental climatic zone.

Intralymphatic immunotherapy with one or two allergens renders similar clinical response in patients with allergic rhinitis due to birch and grass pollen

Introduction

There is a need for a fast, efficient and safe way to induce tolerance in patients with severe allergic rhinitis. Intralymphatic immune therapy has been shown to be effective.

Methods

Patients with severe birch and timothy allergy were randomized and received three doses of 0.1 ml of birch and 5‐grass allergen extracts (10,000 SQ units/ml, ALK‐Abelló), or birch and placebo or 5‐grass and placebo by ultrasound‐guided injections into inguinal lymph nodes at monthly intervals. Rhinoconjunctivitis total symptom score, medication score and rhinoconjunctivitis quality of life questionnaire were evaluated before treatment and after each birch and grass pollen season during three subsequent years. Circulating proportions of T helper subsets and allergen‐induced cytokine and chemokine production were analysed by flow cytometry and Luminex.

Results

The three groups reported fewer symptoms, lower use of medication and improved quality of life during the birch and grass pollen seasons each year after treatment at an almost similar rate independently of treatment with one or two allergens. Mild local pain was the most common adverse event. IgE levels to birch decreased, whereas birch‐induced IL‐10 secretion increased in all three groups. IgG4 levels to birch and timothy and skin prick test reactivity remained mainly unchanged. Conjunctival challenge tests with timothy extract showed a higher threshold for allergen. In all three groups, regulatory T cell frequencies were increased 3 years after treatment.

Conclusions

Intralymphatic immunotherapy with one or two allergens in patients with grass and birch pollen allergy was safe, effective and may be associated with bystander immune modulatory responses.

Clinical Trial Registration: EudraCT (2013‐004726‐28).

Atmospheric transport reveals grass pollen dispersion distances

Identifying the origin of bioaerosols is of central importance in many biological disciplines, such as human health, agriculture, forestry, aerobiology and conservation. Modelling sources, transportation pathways and sinks can reveal how bioaerosols vary in the atmosphere and their environmental impact. Grass pollen are particularly important due to their widely distributed source areas, relatively high abundance in the atmosphere and high allergenicity. Currently, studies are uncertain regarding sampler representability between distance and sources for grass pollen. Using generalized linear modelling, this study aimed to analyse this relationship further by answering the question of distance-to-source area contribution. Grass pollen concentrations were compared between urban and rural locations, located 6.4 km apart, during two years in Worcestershire, UK. We isolated and refined vegetation areas at 100 m × 100 m using the 2017 CEH Crop Map and conducted atmospheric modelling using HYSPLIT to identify which source areas could contribute pollen. Pollen concentrations were then modelled with source areas and meteorology using generalized linear mixed-models with three temporal variables as random variation. We found that the Seasonal Pollen Integral for grass pollen varied between both years and location, with the urban location having higher levels. Day of year showed higher temporal variation than the diurnal or annual variables. For the urban location, grass source areas within 30 km had positive significant effects in predicting grass pollen concentrations, while source areas within 2-10 km were important for the rural one. The source area differential was likely influenced by an urban-rural gradient that caused differences in the source area contribution. Temperature had positive highly significant effects on both locations while precipitation affected only the rural location. Combining atmospheric modelling, vegetation source maps and generalized linear modelling was found to be a highly accurate tool to identify transportation pathways of bioaerosols in landscape environments.

Higher Wheal Sizes of Dermatophagoides farinae Sensitization Exhibit Worse Nasal Symptoms in Allergic Rhinitis Patients

Allergic rhinitis (AR) is a global health burden and it manifests in both nasal and non-nasal symptoms. Skin prick test (SPT) is a routine procedure to diagnose AR sensitized to common allergens including house dust mites (HDMs). The degree of sensitivity of a patient toward allergens is determined by the size of the wheal formed by SPT procedure. SPT wheal sizes are influenced by recent anti-histamine usage, however it remains unclear if SPT wheal sizes are also influenced by other factors. In this study, we set out to investigate the association between SPT wheal sizes with the demographical, clinical and environmental characteristics, as well as nasal and non-nasal symptoms severity scores, of AR patients (n = 30) sensitized to common HDMs (i.e., Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Blomia tropicalis). We showed that SPT wheal sizes of HDM allergens were not associated with clinical, demographical and environmental characteristics examined. Nonetheless, significant correlations were observed between SPT wheal sizes of D. farinae sensitization with worse severity scores of all five nasal symptoms examined (i.e., sneezing, runny nose, itchy nose, congestion and postnasal drip) and four of the six non-nasal symptoms examined (i.e., throat symptoms, ear symptoms, headache and mental function). Such relationships were not observed in SPT wheal sizes of D. pteronyssinus and B. tropicalis sensitization. We suggest that increased SPT wheal sizes for D. farinae sensitization may predict the likelihood of more severe nasal and, to a lesser extent, non-nasal manifestations in AR patients.

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.

Standardisation of allergen products: 4. Validation of a candidate European Pharmacopoeia standard method for quantification of major grass pollen allergen Phl p 5

BACKGROUND

The aim of the BSP090 project is the establishment of European Pharmacopoeia Chemical Reference Substances (CRSs) in combination with corresponding standard ELISA methods for quantification of major allergens in allergen products. Here, we present data of a Phl p 5-specific sandwich ELISA that proved suitable for the quantification of Phl p 5, one of the major Timothy grass (Phleum pratense) pollen allergens.

METHODS

A Phl p 5-specific ELISA system was assessed with respect to accuracy, precision, inter-assay (within laboratory) and inter-laboratory variations, in a ring trial including 14 laboratories in Europe and the USA. Model samples containing recombinant Phl p 5a CRS as well as native grass pollen extracts were analysed. Each participant was instructed to perform at least one preliminary assay to familiarise with the protocol, followed by three independent assays.

RESULTS

The candidate standard ELISA proved suitable to quantify recombinant and native Phl p 5 with satisfactory precision (93% of results within ±30% acceptance range). Inter-assay variation (max. GCV 24%) and especially inter-laboratory variation (max. GCV 13%) showed conclusive results. When assessing accuracy by means of recovery of recombinant spikes from a grass pollen extract matrix, similarly satisfactory spike recovery results were observed for the two spikes with higher concentrations (all within ±30% acceptance range), whereas recovery of the lowest concentration spike was slightly poorer with mean results of six laboratories exceeding acceptance range.

CONCLUSIONS

Based on the collaborative study results, the assessed Phl p 5-specific immunoassay is appropriate to be proposed as European Pharmacopoeia standard method.

Inhalant Mammal-Derived Lipocalin Allergens and the Innate Immunity

A major part of important mammalian respiratory allergens belongs to the lipocalin family of proteins. By this time, 19 respiratory mammalian lipocalin allergens have been registered in the WHO/IUIS Allergen Nomenclature Database. Originally, lipocalins, small extracellular proteins (molecular mass ca. 20 kDa), were characterized as transport proteins but they are currently known to exert a variety of biological functions. The three-dimensional structure of lipocalins is well-preserved, and lipocalin allergens can exhibit high amino acid identities, in several cases more than 50%. Lipocalins contain an internal ligand-binding site where they can harbor small principally hydrophobic molecules. Another characteristic feature is their capacity to bind to specific cell-surface receptors. In all, the physicochemical properties of lipocalin allergens do not offer any straightforward explanations for their allergenicity. Allergic sensitization begins at epithelial barriers where diverse insults through pattern recognition receptors awaken innate immunity. This front-line response is manifested by epithelial barrier-associated cytokines which together with other components of immunity can initiate the sensitization process. In the following, the crucial factor in allergic sensitization is interleukin (IL)-4 which is needed for stabilizing and promoting the type 2 immune response. The source for IL-4 has been searched widely. Candidates for it may be non-professional antigen-presenting cells, such as basophils or mast cells, as well as CD4+ T cells. The synthesis of IL-4 by CD4+ T cells requires T cell receptor engagement, i.e., the recognition of allergen peptides, which also provides the specificity for sensitization. Lipocalin and innate immunity-associated cell-surface receptors are implicated in facilitating the access of lipocalin allergens into the immune system. However, the significance of this for allergic sensitization is unclear, as the recognition by these receptors has been found to produce conflicting results. As to potential adjuvants associated with mammalian lipocalin allergens, the hydrophobic ligands transported by lipocalins have not been reported to enhance sensitization while it is justified to suppose that lipopolysaccharide plays a role in it. Taken together, type 2 immunity to lipocalin allergens appears to be a harmful immune response resulting from a combination of signals involving both the innate and adaptive immunities.

Cross-sectional study on exhaled nitric oxide in relation to upper airway inflammatory disorders with regard to asthma and perennial sensitization

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a well-known marker of type-2 inflammation. FeNO is elevated in asthma and allergic rhinitis, with IgE sensitization as a major determinant.

OBJECTIVE

We aimed to see whether there was an independent association between upper airway inflammatory disorders (UAID) and FeNO, after adjustment for asthma and sensitization, in a multi-centre population-based study.

METHODS

A total of 741 subjects with current asthma and 4155 non-asthmatic subjects participating in the second follow-up of the European Community Respiratory Health Survey (ECRHS III) underwent FeNO measurements. Sensitization status was based on measurement of IgE against airborne allergens; information on asthma, UAID and medication was collected through interview-led questionnaires. Independent associations between UAID and FeNO were assessed in adjusted multivariate regression models and test for interaction with perennial sensitization and asthma on the relation between UAID and FeNO were made.

RESULTS

UAID were associated with higher FeNO after adjusting for perennial sensitization, asthma and other confounders: with 4.4 (0.9-7.9) % higher FeNO in relation to current rhinitis and 4.8 (0.7-9.2) % higher FeNO in relation to rhinoconjunctivitis. A significant interaction with perennial sensitization was found in the relationship between current rhinitis and FeNO (p = .03) and between rhinoconjunctivitis and FeNO (p = .03). After stratification by asthma and perennial sensitization, the association between current rhinitis and FeNO remained in non-asthmatic subjects with perennial sensitization, with 12.1 (0.2-25.5) % higher FeNO in subjects with current rhinitis than in those without.

CONCLUSIONS & CLINICAL RELEVANCE

Current rhinitis and rhinoconjunctivitis was associated with higher FeNO, with an interaction with perennial sensitization. This further highlights the concept of united airway disease, with correlations between symptoms and inflammation in the upper and lower airways and that sensitization needs to be accounted for in the relation between FeNO and rhinitis.

Sensitisation patterns and allergy outcomes in pregnant women living in the urban area

BACKGROUND

Worldwide, allergy affects more than one billion people, with particularly rising prevalence in industrialised areas. Specifically, young adults appear to be predominantly targeted for an allergy diagnosis. Allergic diseases in pregnancy are mainly pre-existing but could also occur de novo. The immunological changes while pregnant, with increased Th2 lymphocyte activity, can facilitate allergen sensitisation.

OBJECTIVE

The aim of this study was to evaluate the pattern of specific IgE (sIgE) sensitisation to common inhalant and food allergens in pregnancy, and assess its relationship to self-reported allergic disease.

METHODS

We assessed 200 pregnant women, aged 20-38 years (mean age = 29 years), participant of ELMA (Epigenetic Hallmark of Maternal Atopy and Diet) study, living in a metropolitan area, with no pregnancy associated metabolic complications, for total IgE and allergen specific IgE to 20 allergens.

RESULTS

48% of pregnant women were sensitised to at least one allergen, at a cut-off point of 0.35 kU/L and they were assigned as atopic. However 42% in atopic group were not reporting any allergic disease. The most common inhalant allergens were: pollen (24.5%) and animal dander (23.5%). The most common food allergens were: cow's milk (5.5%) and apples (4.5%). 7.5% of women reported asthma, 21.5% allergic rhinitis, 11.5% atopic dermatitis and 18.5% food allergy. 8.5% of were taking medication for asthma or allergies. Atopic dermatitis had the highest tendency to become more severe during pregnancy. Total IgE values were significantly higher in atopic women.

CONCLUSIONS

Allergic sensitisation is a common phenomenon in pregnancy. Some sensitisations could be asymptomatic. Further studies should investigate if sensitisation in mothers confers risks for immune alterations in their children.

Differential Correlations among Allergy Tests According to Indoor Allergens in Allergic Rhinitis

OBJECTIVES

Several allergy tests are used for the diagnosis of allergic rhinitis; however, few studies have reported a direct comparison of the skin prick test (SPT), multiple allergen simultaneous test (MAST), and ImmunoCAP according to specific allergens. This study aimed to evaluate the correlations between each test and allergic rhinitis symptoms and to evaluate the correlations of the MAST and ImmunoCAP with the SPT for representative indoor allergens in Korea.

METHODS

Electronic medical charts were retrospectively reviewed, and 698 patients with allergic rhinitis who had performed SPT, MAST, and ImmunoCAP were enrolled. Correlations between each allergy test for 4 representative indoor allergens and the symptoms of allergic rhinitis were analyzed. Agreements of the MAST and ImmunoCAP with the SPT were compared according to each allergen.

RESULTS

The SPT showed higher correlations with allergic rhinitis symptoms for 4 indoor allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat, and dog allergens) than the MAST or ImmunoCAP. In comparison between the MAST and SPT, the least correlation was observed for the dog allergen, whereas between the ImmunoCAP and SPT, the least correlation was observed for the cat allergen. The correlation between the ImmunoCAP and SPT was higher than that between the MAST and SPT for the dog allergen, whereas no significant differences were noted for other allergens.

CONCLUSIONS

Overall, the SPT showed a higher correlation with allergic rhinitis symptoms than the MAST or ImmunoCAP for 4 indoor allergens. ImmunoCAP showed similar reactivity to MAST; however, it showed better positivity with dog allergen in patients who were reactive to the allergen in the SPT. Care should be taken while evaluating dog allergen sensitization using the MAST.

Effectiveness and safety of a glutaraldehyde-modified, L-tyrosine-adsorbed and monophosphoryl lipid A-Adjuvanted allergen immunotherapy in patients with allergic asthma sensitized to olive pollen: A retrospective, controlled real-world study

Background

Allergy to olive pollen is one of the primary causes of allergic asthma in Spain. Even though allergen immunotherapy (AIT) has shown clinical benefits in patients sensitized to different allergens, studies in asthmatic patients sensitized to olive pollen are insufficient.

Objective

To assess the effectiveness and safety of an ultra-short course of AIT with an L-tyrosine-adsorbed and monophosphoryl lipid A-adjuvanted olive pollen and olive/grass pollen extract (Pollinex Quattro®) in patients with allergic asthma in the real-world setting.

Methods

Retrospective, controlled study including patients with asthma, with and without allergic rhinitis, caused by sensitization to olive pollen from 11 centers in Spain. Patients received out-of-season (October–March) treatment with AIT in addition to their pharmacological treatment (active group) or pharmacological treatment (control group). Effectiveness variables, including unscheduled visits to the healthcare center, emergency room admissions, symptoms of asthma and rhinitis (following GEMA and ARIA classifications, respectively), and use of medication to treat asthma and rhinitis during the subsequent pollen season were compared between treatment groups.

Results

Of 131 study patients, 42 were treated with their usual asthma medication (control group) and 89 were treated with AIT (active group), either Pollinex Quattro® 100% olive pollen (n = 43, 48.3%) or 50% olive pollen/50% grass pollen (n = 46, 51.7%). Patients’ demographic and clinical characteristics were similar between groups. The mean (SD) number of unscheduled visits to a healthcare center and emergency room admissions due to allergy symptoms was 2.19 (1.40) and 0.43 (0.63) in the control group, and 1.09 (1.25) and 0.11 (0.51) in the active group (P = 0.001 and P = 0.006, respectively). Severity and control of asthma symptoms remained unchanged (P = 0.347 and P = 0.179, respectively), rhinitis type improved (P = 0.025), and severity remained unchanged in the active compared to the control group. The use of short-acting beta-agonists and inhaled corticosteroids to treat asthma symptoms decreased in the active vs. the control group (P = 0.001 and P = 0.031, respectively). Twelve (13.5%) and two (2.2%) patients in the active group experienced local adverse reactions (edema, swelling, erythema, hives, pruritus, and heat), and systemic adverse reactions (hypertensive crisis and low-grade fever) to AIT, respectively; none was serious.

Conclusion

AIT with Pollinex Quattro® specific for olive pollen and olive/grass pollens resulted in reduced visits to the healthcare center and emergency room and the use of asthma medication during the pollen season, indicating that this treatment was safe and effective in treating asthma in patients sensitized to these pollens.

Climate change in Switzerland: Impact on hazel, birch, and grass pollen on the basis of half a century of pollen records (1969 - 2018)

As indicated by the Intergovernmental Panel on Climate Change (IPCC), human activities are estimated to have caused ~ 1.0 °C of global warming above pre-industrial levels. The impact of this global warming is diverse and pertains also plant biology. The start of the pollen season as well as the observed quantities of pollen have been considered indicators of the impact of climate change. Switzerland has one of the longest pollen time series now – more than half a century. It has been tested whether the impact of climate change is robust by checking with this long time series of different pollen like hazel, birch, and grass as prominent representatives of triggers of hay fever. The results indicate that based on a time series of 50 years, the pollen seasons of hazel, birch, and grass started earlier as the temperature increased. Comparing the annual amount of pollen, a relevant increase is only observed for hazel. However, it must be considered that in the observed 50 years there was a land use change from grass land to built-up land due to the increase of population, and yet certain pollen counts increased considerably.

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.

Atopy and allergic diseases among Saudi young adults: A cross-sectional study

Objective

In this cross-sectional study, we aimed to determine the prevalence of asthma and other allergic diseases among a homogenous group of students attending the health colleges of a Saudi university and to investigate the relationship between their atopy profile and associated clinical symptoms of allergic diseases.

Methods

A total of 222 students completed the International Study of Asthma and Allergies in Childhood questionnaire and underwent skin prick testing (SPT) using a standardized panel of allergenic extracts.

Results

Overall prevalence of physician-diagnosed allergic diseases was 27% for bronchial asthma (BA), 13.1% for atopic dermatitis (AD), and 5% for allergic rhinitis (AR). Atopy was present in 90 (40.5%) students. Students with atopic disease were more likely to have physician-diagnosed BA, AR, and AD. Atopy and polysensitization was more frequent among male than female students. SPT results were positive in 20.8% of participants for Bermuda grass, 18.9% for cat fur, and 12.7% for Dermatophagoides pteronyssinus .

Conclusion

The prevalence of atopy and allergic diseases in Saudi young adults is high and worrisome. Comorbid allergic diseases were more prevalent among our participants with atopic disease. Determination of allergen sensitization patterns in patients with atopic disease is crucial for selecting proper preventive and therapeutic strategies.

Allergen immunotherapy in asthma: current evidence

Background: Allergic asthma is the predominant phenotype in clinical practice. Allergen immunotherapy is the only curative and specific approach for the treatment of allergies with clinical benefits for several years after its discontinuation. Despite advances, the use of allergen immunotherapy in allergic asthma is still suboptimal and controversial.Objective: The purpose of this article is to review the published data about the impact of allergen immunotherapy with the most commonly used allergen extracts on allergic asthma outcomes, including both clinical parameters and patients' subjective experience (quality of life).Methods: As data sources several databases were used, including PubMed, Scopus, Web of Science (2002-2019) and search in English and Spanish languages was performed using the following terms: "allergen immunotherapy" and "asthma" in combination with "house dust mite", "birch pollen", "grass pollen", "olive tree pollen", "molds", "pets" and "asthma quality of life". Randomised control trials and meta-analysis from reviewed publications were selected.Results: Emerging data relating to the positive impact on asthma outcomes of allergen immunotherapy allows the addition of this treatment as a therapeutic option in mild to moderate asthmatics sensitized to house dust mite and pollens. Limited data are available for patients sensitized to molds and pets, as well in severe allergic asthma population.Conclusion: Allergen immunotherapy remains a potential therapeutic option for some patients with allergic asthma. Further research is needed to define the optimal period of treatment, the possible therapeutic role in the treatment of severe allergic asthma, and the cost-effectiveness of allergen immunotherapy in asthmatic patients.

Strong dose response after immunotherapy with PQ grass using conjunctival provocation testing

Background

Pollinex Quattro Grass (PQ Grass) is an effective, well-tolerated, short pre-seasonal subcutaneous immunotherapy to treat seasonal allergic rhinoconjunctivitis (SAR) due to grass pollen. In this Phase II study, 4 cumulative doses of PQ Grass and placebo were evaluated to determine its optimal cumulative dose.

Methods

Patients with grass pollen-induced SAR were randomised to either a cumulative dose of PQ Grass (5100, 14400, 27600 and 35600 SU) or placebo, administered as 6 weekly subcutaneous injections over 31-41 days (EudraCT number 2017-000333-31). Standardized conjunctival provocation tests (CPT) using grass pollen allergen extract were performed at screening, baseline and post-treatment to determine the total symptom score (TSS) assessed approximately 4 weeks after dosing. Three models were pre-defined (Emax, logistic, and linear in log-dose model) to evaluate a dose response relationship.

Results

In total, 95.5% of the 447 randomized patients received all 6 injections. A highly statistically significant (p < 0.0001), monotonic dose response was observed for all three pre-specified models. All treatment groups showed a statistically significant decrease from baseline in TSS compared to placebo, with the largest decrease observed after 27600 SU (p < 0.0001). The full course of 6 injections was completed by 95.5% of patients. Treatment-emergent adverse events were similar across PQ Grass groups, and mostly mild and transient in nature.

Conclusions

PQ Grass demonstrated a strong curvilinear dose response in TSS following CPT without compromising its safety profile.

Efficacy and safety of sublingual dust mite drops in children with mono- or polysensitized allergic rhinitis

OBJECTIVE

To explore the efficacy and safety of sublingual house dust mite (HDM) drops in children with mono- or polysensitized allergic rhinitis.

METHODS

We conducted a retrospective cohort study of 65 children with monosensitized AR and 118 children with polysensitized AR who were scheduled for sublingual administration of HDM drops from January 2015 to June 2016. Interleukin (IL)-2, IL-4, and IL-17α, transforming growth factor-β1 (TGF-β1), specific immunoglobulin E (IgE), and specific IgG4 were detected by ELISA. The efficacies were assessed using symptoms score and medication score. All the outcomes were measured 1 month before the study and 1 month after the end of the 2-year treatment.

RESULTS

The total nasal symptoms score (TNSS) decreased significantly from 11.27 (9.81 ± 12.73) at baseline to 3.48(1.98 ± 4.98) at the end of sublingual treatment for the monosensitized AP group (t = 30.00, P < 0.01), and from 11.54(10.04 ± 13.04) to 3.56 (2.00 ± 5.16) for the polysensitized AR group (t = 40.05, P < 0.01), respectively. IL-2 and TGF-β1 increased significantly after treatment in contrast with before treatment in both the monosensitized group and the polysensitized group (both P < 0.01). In contrast, IL-4 and IL-17α decreased significantly after treatment compared with the baseline in both groups (both P < 0.01). Sublingual HDM drops were generally safe and well tolerant in both groups.

CONCLUSIONS

This study confirmed the efficacy and safety of sublingual AIT in both monosensitized and polysensitized AR patients (Chinese children).

New toxicity testing of PQ grass allergy immunotherapy to support product development

PQ Grass represents an allergen-specific immunotherapy for pre-seasonal treatment of patients with seasonal allergic rhinitis (or rhinoconjunctivitis) with or without mild-to-moderate bronchial asthma. It consists of a native pollen extract for 13 grass species, chemically modified with glutaraldehyde, and adsorbed to l-tyrosine in a microcrystalline form with addition of the adjuvant Monophosphoryl Lipid A (MPL^® ). Previous non-clinical safety testing, including rat repeat dose toxicity in adult and juvenile animals, rat reproductive toxicity and rabbit local tolerance studies showed no safety findings of concern. A new Good Laboratory Practice compliant rat subcutaneous repeat dose toxicity study to evaluate a higher clinical dose and modified posology (once every 2 weeks for 13 weeks) showed no signs of toxicity. As seen in previous studies, relatively minor, immunostimulatory effects were seen such as reversible increased white cell count (notably neutrophils), increased globulin level (resulting in decreased A/G ratio) and increased fibrinogen as well as minor dose site reaction in the form of inflammatory cell infiltrate. These findings are likely due to the immunostimulatory nature of MPL and/or the presence of l-tyrosine within the adjuvanted vaccine. This new toxicity study with PQ Grass therefore supports longer posology with higher dose levels.

Furry Animal Allergen Component Sensitization and Clinical Outcomes in Adult Asthma and Rhinitis

BACKGROUND

Sensitization to allergen components has been linked to asthma in children, but studies in adults are lacking.

OBJECTIVE

To study the relation of sensitization to furry animal allergen components to risk of asthma, rhinitis, and markers of asthma severity in adults.

METHODS

From the West Sweden Asthma Study, a random population-representative sample of adults aged 16 to 75 years, 2006 participants were clinically examined; 1872 were analyzed for serum IgE level to a mix of aeroallergens. Those with an IgE level of more than 0.35 kUA/L to cat, dog, or horse allergen components were analyzed for specific cat (Felis domesticus [Fel d 1, Fel d 2, and Fel d 4]), dog (Canis familiaris [Can f 1, Can f 2, Can f 3, and Can f 5]), and horse (Equus caballus [Equ c 1]) allergen components. We defined monosensitization, double sensitization, and polysensitization (>2 components) patterns and applied cluster analysis to derive distinct sensitization clusters.

RESULTS

Sensitization to each allergen component, lipocalins, each sensitization pattern, and each sensitization cluster (nonsensitized, Fel d 1-driven sensitized, and multisensitized clusters) was associated with substantial increased risk of asthma, rhinitis, concomitant asthma and rhinitis, and Asthma Control Test-controlled asthma. Fel d 1, Can f 1, Can f 2, Can f 3, polysensitization, and multisensitized cluster were further associated with increased fractional exhaled nitric oxide and eosinophil levels, but with lower PD20 methacoline (provocative dose of methacholine causing a 20% drop in FEV1) values. There was no association with asthma exacerbations, FEV1 predicted values, emergency visits or regular oral steroid use, and neutrophil levels.

CONCLUSIONS

Sensitization to furry animal allergen components is an important predictor of asthma, rhinitis, and markers of asthma severity with increased blood eosinophils, fractional exhaled nitric oxide, and airway hyperreactivity.

Characterization of sensitization to furry animal allergen components in an adult population

BACKGROUND

There are paucity of data on sensitization to furry animal allergen components in adults. Furry animals are major sensitizers and contributors to asthma burden in northern Europe and North America.

OBJECTIVE

To characterize sensitization patterns to furry animal allergen components in Swedish adults.

METHODS

Based on the West Sweden Asthma Study, a random population (n = 1103) and an asthma sample (n = 769) were tested for allergen sensitization using Phadiatop^® . Those with IgE ≥ 0.35 kU_A /L were tested for cat (Fel d 1, 2, and 4), dog (Can f 1, 2, 3, and 5), and horse (Equ c 1) allergen component sensitization. We defined allergen component poly-sensitization patterns, identified data-driven sensitization clusters, described component sensitization overlaps, and assessed determinants of sensitization patterns.

RESULTS

The prevalence of allergen component sensitization ranged from 0.8% for Fel d 2 and Can f 3 to 8.9% for Fel d 1. The most common dog component was Can f 5 (3.6%); 2.1% were sensitized to Equ c 1. Those sensitized to Fel d 2 and Fel d 4 were commonly sensitized to Fel d 1. The most common dog component overlap was between Can f 1/Can f 2 and Can f 5. Mono-sensitization was 5.6%, double sensitization 1.5% and poly-sensitization 2.1%. Sensitization was always higher in the asthma than in the random sample. Three sensitization clusters were derived, namely non-sensitized (90% in random vs 66% in asthma sample); Fel d 1-driven sensitized (7% vs 19%); and multi-sensitized (3% vs 15%). Key determinants of sensitization were gender, age, raised on a farm, family history of allergy or asthma, smoking, and occupational exposure to dust or fumes.

CONCLUSIONS & CLINICAL RELEVANCE

Fel d 1 and Can f 5 are the most common cat and dog components sensitization in this adult Swedish population. Mono-sensitization is more common than poly-sensitization. This detailed characterization highlights the current distribution of furry animal allergen components in Swedish adults, and their impact on clinical outcomes of asthma will be further explored.

Geographic and demographic variations of inhalant allergen sensitization in Koreans and non-Koreans

BACKGROUND

To diagnose and treat respiratory allergic diseases, it is important to identify the specific allergens involved. Many differences exist between common inhalant allergens depending on the residential environment and demographic factors. This study aimed to compare common inhalant allergens between Koreans and non-Koreans according to their residential region, age, and sex.

METHODS

This study evaluated 15,334 individuals who underwent serum tests for multiple allergen-specific immunoglobulin E at a tertiary academic medical center between January 2010 and December 2016. The individuals included 14,786 Koreans and 548 non-Koreans. The AdvanSure™ Allostation assay (LG Life Science, Korea) was used to test for 33 inhalant allergens.

RESULTS

The house dust mite (HDM) was the most common allergen in both Koreans and non-Koreans, although the proportion of individuals with HDM sensitization was greater among Koreans. High sensitization rates for various pollen types were detected among Koreans in Gangwon region, whereas Japanese cedar pollen was unique among Koreans in Jeju region. Grass pollen and animal dander were relatively common among individuals from the Americas, whereas weed and grass pollen accounted for the 10 most common allergens for individuals from Central Asia. The total sensitization rate, sensitization to HDM, and sensitization to animal dander peaked among adolescents and young adults, then subsequently decreased with age.

CONCLUSIONS

This large-scale study demonstrates that various regional and age-related differences exist in the allergen sensitization rates of Koreans and non-Koreans. These data could be useful for development of avoidance measures, immunotherapy for causative allergens, and policymaking regarding allergic diseases.

Cross-Reactive Aeroallergens: Which Need to Cross Our Mind in Food Allergy Diagnosis?

Secondary food allergies due to cross-reactivity between inhalant and food allergens are a significant and increasing global health issue. Cross-reactive food allergies predominantly involve plant-derived foods resulting from a prior sensitization to cross-reactive components present in pollen (grass, tree, weeds) and natural rubber latex. Also, primary sensitization to allergens present in fungi, insects, and both nonmammalian and mammalian meat might induce cross-reactive food allergic syndromes. Correct diagnosis of these associated food allergies is not always straightforward and can pose a difficult challenge. As a matter of fact, cross-reactive allergens might hamper food allergy diagnosis, as they can cause clinically irrelevant positive tests to cross-reacting foods that are safely consumed. This review summarizes the most relevant cross-reactivity syndromes between inhalant and food allergens. Particular focus is paid to the potential and limitations of confirmatory testing such as skin testing, specific IgE assays, molecular diagnosis, and basophil activation test.

IgE sensitization to food allergens and airborne allergens in relation to biomarkers of type 2 inflammation in asthma

BACKGROUND

We have recently reported that sensitization to food allergens and sensitization to airborne allergens had independent associations with increased fraction of exhaled nitric oxide (FeNO) and blood eosinophils in middle-aged adults and in young subjects with asthma.

OBJECTIVE

To investigate the relation between IgE sensitization and several type 2 inflammation biomarkers in adult asthmatics.

METHODS

FeNO, urinary eosinophil-derived neurotoxin (U-EDN), serum eosinophil cationic protein (S-ECP) and periostin were measured in 396 asthmatics, aged 17-76 years, from the Swedish GA2LEN study. Sensitization to airborne allergens was examined with skin prick tests (≥3 mm wheal) and sensitization to food allergens with measurement of specific IgE (≥0.35 kU/L).

RESULTS

Asthmatics sensitized to food allergens had higher FeNO, 22.3 ppb (18.6, 26.7) vs 16.1 ppb (14.2, 18.2) (P = .005), S-ECP, 17.7 mg/L (14.8, 21.1) vs 12.8 mg/L (10.9, 14.9) (P = .01), and periostin, 73.7 (67.5, 80.3) ng/mL vs 59.9 (55.8, 64.2) ng/mL (P = .003), than non-sensitized subjects. Periostin levels in this group were also significantly higher than in the group sensitized only to airborne allergens (P = .01). Sensitization to food allergens related independently to FeNO (P = .02), S-ECP (P = .006) and periostin (P = .004), whereas sensitization only to airborne allergens related only to FeNO (P = .02) after adjustments for age, sex, height, weight and smoking history. FeNO correlated weakly with S-ECP (r = .17, P < .001), periostin (r = .19, P < .001) and U-EDN (0.16, P < .001). S-ECP also correlated weakly with U-EDN (r = .12, P = .02). None of the correlations between the remaining pairs of markers of type 2 inflammation were significant.

CONCLUSIONS & CLINICAL RELEVANCE

Sensitization to food allergens related to several local and systemic type 2 inflammation markers, such as FeNO, S-ECP and periostin. Assessing the profile of allergic sensitization, including to food allergens, might improve the understanding and interpretation of inflammatory markers and potentially improve asthma management.

Immunotherapy for pet allergies

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

Poaceae pollen as the leading aeroallergen worldwide: A review

The Poaceae family comprises over 12 000 wind-pollinated species, which release large amounts of pollen into the atmosphere. Poaceae pollen is currently regarded as the leading airborne biological pollutant and the chief cause of pollen allergy worldwide. Sensitization rates vary by country, and those variations are reviewed here. Grass pollen allergens are grouped according to their protein structure and function. In Poaceae, although species belonging to different subfamilies are characterized by distinct allergen subsets, there is a considerable degree of cross-reactivity between many species. Cross-reactivity between grass pollen protein and fresh fruit pan-allergens is associated with the appearance of food allergies. The additional influence of urban pollution may prompt a more severe immunological response. The timing and the intensity of the pollen season are governed by species genetics, but plant phenology is also influenced by climate; as a result, climate changes may affect airborne pollen concentrations. This article reviews the findings of worldwide research which has highlighted the major impact of climate change on plant phenology and also on the prevalence and severity of allergic disease.

Mapping allergenic pollen vegetation in UK to study environmental exposure and human health

Allergenic pollen is produced by the flowers of a number of trees, grasses and weeds found throughout the UK. Exposure to such pollen grains can exacerbate pollen-related asthma and allergenic conditions such as allergic rhinitis (hay fever). Maps showing the location of these allergenic taxa have many applications: they can be used to provide advice on risk assessments; combined with health data to inform research on health impacts such as respiratory hospital admissions; combined with weather data to improve pollen forecasting systems; or as inputs to pollen emission models. In this study we present 1km resolution maps of 12 taxa of trees, grass and weeds found in the UK. We have selected the main species recorded by the UK pollen network. The taxa mapped in this study were: Alnus (alder), Fraxinus (ash), Betula (birch), Corylus (hazel), Quercus (oak), Pinus (pine) and Salix (willow), Poaceae (grass), Artemisia (mugwort), Plantago (plantain), Rumex (dock, sorrels) and Urtica (nettle). We also focus on one high population centre and present maps showing local level detail around the city of London. Our results show the different geographical distributions of the 12 taxa of trees, weeds and grass, which can be used to study plants in the UK associated with allergy and allergic asthma. These maps have been produced in order to study environmental exposure and human health, although there are many possible applications. This novel method not only provides maps of many different plant types, but also at high resolution across regions of the UK, and we uniquely present 12 key plant taxa using a consistent methodology. To consider the impact on human health due to exposure of the pollen grains, it is important to consider the timing of pollen release, and its dispersal, as well as the effect on air quality, which is also discussed here.

Novel approaches and perspectives in allergen immunotherapy

In this review, we report on relevant current topics in allergen immunotherapy (AIT) which were broadly discussed during the first Aarhus Immunotherapy Symposium (Aarhus, Denmark) in December 2015 by leading clinicians, scientists and industry representatives in the field. The aim of this symposium was to highlight AIT-related aspects of public health, clinical efficacy evaluation, mechanisms, development of new biomarkers and an overview of novel therapeutic approaches. Allergy is a public health issue of high socioeconomic relevance, and development of evidence-based action plans to address allergy as a public health issue ought to be on national and regional agendas. The underlying mechanisms are in the focus of current research that lays the ground for innovative therapies. Standardization and harmonization of clinical endpoints in AIT trials as well as current knowledge about potential biomarkers have substantiated proof of effectiveness of this disease-modifying therapeutic option. Novel treatments such as peptide immunotherapy, intralymphatic immunotherapy and use of recombinant allergens herald a new age in which AIT may address treatment of allergy as a public health issue by reaching a large fraction of patients.

Nanoparticle-allergen complexes for allergen immunotherapy

Allergen-specific immunotherapy was introduced in clinical settings more than 100 years ago. It remains the only curative approach to treating allergic disorders that ameliorates symptoms, reduces medication costs, and blocks the onset of new sensitizations. Despite this clinical evidence and knowledge of some immunological mechanisms, there remain some open questions regarding the safety and efficacy of this treatment. This suggests the need for novel therapeutic approaches that attempt to reduce the dose and frequency of treatment administration, improving patient compliance, and reducing costs. In this context, the use of novel adjuvants has been proposed and, in recent years, biomedical applications using nanoparticles have been exploited in the attempt to find formulations with improved stability, bioavailability, favorable biodistribution profiles, and the capability of targeting specific cell populations. In this article, we review some of the most relevant regulatory aspects and challenges concerning nanoparticle-based formulations with immunomodulatory potential, their related immunosafety issues, and the nature of the nanoparticles most widely employed in the allergy field. Furthermore, we report in vitro and in vivo data published using allergen/nanoparticle systems, discuss their impact on the immune system in terms of immunomodulatory activity and the reduction of side effects, and show that this strategy is a novel and promising tool for the development of allergy vaccines.

Prevalence of allergen sensitization in 1000 adults in Saskatchewan

BACKGROUND

The prevalence of sensitization varies geographically based on multiple environmental factors including humidity. The aim of this study was to determine the prevalence of atopy in symptomatic adults. More importantly we aimed to obtain a regional statistic of sensitization to common allergens given Saskatchewan's dry climate.

METHODS

One thousand consecutive symptomatic adults were screened for atopy via skin prick test over 10 years (2006-2016) in the Division of Respirology. An atopic screen was performed with twenty common aeroallergens by a single investigator, Dr. D. Cockcroft. A positive test was considered to be a wheal ≥3 mm and markedly positive reactions ≥8 mm were also documented.

RESULTS

The prevalence of atopy by means of a positive skin test (≥3 mm) was 45.5%. The prevalence of one or more markedly positive reactions (≥8 mm) was 29.5% of the total population. The most frequent sensitization was to cat dander (58.2%), followed by mixed grass (32.1%), and birch (26.8%). Dust mite sensitization was 22.4% and mouse 6.2%. A positive epidemiology screen for cat/grass/mite would have incorporated 82.0% (n = 373) of subjects with positive skin tests. Those who failed the cat/grass/mite screen were mainly sensitized to trees (n = 34), molds (n = 22), weeds (n = 7), and animals (n = 8).

CONCLUSIONS

There is a high prevalence of cat sensitization in Saskatchewan, much higher than recorded in other centers internationally. This is likely due to a high proportion of cat ownership. The prevalence of mite sensitization is lower than those mentioned at other centres likely due to Saskatchewan's dry climate. The significance of the rate of markedly positive reactions (≥8 mm wheal) when compared to humid areas with higher burden of mite is unknown. There is a low prevalence of roach also likely due to the dry climate and mouse sensitization was low but still identified as a significant indoor allergen. A cat/grass/mite screen may be useful with a 82.0% sensitivity.

Allergic diseases in the elderly: biological characteristics and main immunological and non-immunological mechanisms

Life expectancy and the number of elderly people are progressively increasing around the world. Together with other pathologies, allergic diseases also show an increasing incidence in geriatric age. This is partly due to the growing emphasis on a more accurate and careful diagnosis of the molecular mechanisms that do not allow to ignore the real pathogenesis of many symptoms until now unknown, and partly to the fact that the allergic people from 20 years ago represent the elderly population now. Moreover, environmental pollution predisposes to the onset of allergic asthma and dermatitis which are the result of internal pathologies more than the expression of allergic manifestations. At the same time the food contamination permits the onset of allergic diseases related to food allergy. In this review we provide the state of the art on the physiological changes in the elderly responsible for allergic diseases, their biological characteristics and the major immunological and extra immunological mechanisms. Much emphasis is given to the management of several diseases in the elderly, including anaphylactic reactions. Moreover, some new features are discussed, such as management of asthma with the support of physical activity and the use of the AIT as prevention of respiratory diseases and for the purpose of a real and long lasting benefit. The mechanisms of adverse reactions to drugs are also discussed, due to their frequency in this age, especially in polytherapy regimens. Study of the modifications of the immune system is also of great importance, as regards to the distribution of the lymphocytes and also the presence of a chronic inflammatory disease related to the production of cytokines, especially in prevision of all the possible therapies to be adopted to allow an active and healthy aging.

Patterns of Inhalant Allergen Sensitization and Geographical Variation in Korean Adults: A Multicenter Retrospective Study

Purpose

Inhalant allergen sensitization is one of the major factors involved in the pathogenesis of allergic respiratory diseases. However, the sensitization is determined by interactions between genetic and environmental factors. Thus, testing panels of inhalant allergens may differ among geographical areas. Here we aimed to determine 10 common inhalant allergens in Korean adult patients with suspected respiratory allergies and to examine the variation between different geographical locations.

Methods

A total of 28,954 patient records were retrieved for retrospective analysis, from 12 referral allergy clinics located in 9 different areas. Inclusion criteria were Korean adults (≥18 years old) who underwent the inhalant allergen skin prick test for suspected history of respiratory allergy. The primary outcome was inhalant allergen skin prick response. Demographic and clinical information were also collected. Positive skin prick responses to allergens were defined as allergen-to-histamine wheal ratio ≥1. Based on skin test results, the most prevalent aeroallergens were determined.

Results

The overall prevalence of allergic sensitization was 45.3%. Dermatophagoides farinae and Dermatophagoides pteronyssinus were the most commonly sensitized allergens. Other common inhalant allergens were cat epithelium (8.1%), birch (7.7%), mugwort (6.9%), alder (6.7%), hazel (6.7%), beech (6.7%), oak (6.6%), and Tyrophagus putres (6.2%), in decreasing order frequency. These 10 inhalant allergens explained 90% of inhalant allergen sensitization in the study participants. However, distinct patterns of the 10 inhalant sensitization were observed in patients living in Chungnam and Jeju. American cockroach, Gernam cockroach, and Trichophyton metagrophytes were unique in Chungnam. Orchard, Japanese cedar, and Velvet were unique in Jeju.

Conclusions

The present analysis suggests a panel of 10 most common inhalant allergens in Korean adult patients with suspected respiratory allergies, which explained 90% of inhalant allergen sensitization. This panel can be utilized as a practical and convenient tool for primary practice and epidemiological surveys of respiratory allergic diseases.

Asthma and other allergic diseases among Saudi schoolchildren in Najran: the need for a comprehensive intervention program

BACKGROUND

In the last three decades, an increasing incidence of allergic diseases has been associated with increasing morbidity and mortality in children and young adults.

OBJECTIVES

The study aimed to investigate the prevalence and risk factors associated with allergic diseases among Saudi schoolchildren in the southwestern Saudi region of Najran, and to determine the sensitization of patients to a set of allergens.

DESIGN

Cross-sectional observational study.

SETTING

Primary, intermediate and secondary schools, Najran, Saudi Arabia.

SUBJECTS AND METHODS

All participants completed the Arabic version of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Skin prick tests (SPT) were performed, using a panel of standardized allergenic extracts.

MAIN OUTCOME MEASURE(S)

Prevalence and risk factors associated with pediatric allergic diseases.

RESULTS

The study included 1700 Saudi schoolchildren. The overall prevalence of physician-diagnosed asthma, allergic rhinitis and atopic dermatitis was 27.5%, 6.3% and 12.5%, respectively. Multivariate analysis showed that male gender (adjusted odds ratio [aOR], 1.27), fast food consumption (aOR, 1.53), trucks passing near houses (aOR, 1.86), and having a dog or cat at home (aOR, 1.85) were significant risk factors. A total of 722 (42.5%) children had a positive SPT result to at least one allergen. The most prevalent allergens were grass pollens (60%), cat fur (41.6%), and house dust mites (25%).

CONCLUSIONS

The findings of this study highlight the urgent need for developing an effective interven- tion program including several components working in harmony to control and reduce the burden of allergic diseases.

LIMITATIONS

These results may not be generalizable to the rest of Saudi Arabia.

300 IR HDM tablet: a sublingual immunotherapy tablet for the treatment of house dust mite-associated allergic rhinitis

INTRODUCTION

The once-daily 300 index of reactivity (IR) house dust mite (HDM) tablet (Actair®; Stallergenes Greer, Antony, France/Shionogi & Co. Ltd., Osaka, Japan) is the first sublingual immunotherapy (SLIT) tablet to be approved for the treatment of HDM-induced allergic rhinitis. Areas covered: This drug profile reviews the current body of evidence on the efficacy, safety and tolerability of the 300 IR HDM tablet, its pharmacodynamics, and its role in clinical practice. Expert commentary: Data from its clinical development program demonstrate favorable efficacy and safety in adults and adolescents with HDM-induced allergic rhinitis, irrespective of mono- or polysensitization status, or the presence of comorbid mild asthma. The 300 IR HDM tablet is effective from as early as 2 months after treatment initiation, providing allergic symptom control and a reduction in the need for symptomatic medication, while improving health-related quality of life. Clinical efficacy is maintained for 1 year after treatment is stopped.

High sensitization to house-dust mites in patients with allergic rhinitis in the eastern Black Sea region of Turkey: A retrospective study

OBJECTIVES

Identification of the most common aeroallergens to which patients are sensitized in a specific area is important in the diagnosis and treatment of allergic rhinitis (AR). We determined the distribution of aeroallergens, detected by skin-prick tests (SPT), in adult patients with AR in the Eastern Black Sea region of Turkey and compared the results with the other regions of Turkey and in the world.

METHODS

The medical records of SPT performed on 1457 patients with symptoms of AR (with regard to the Allergic Rhinitis and its Impact on Asthma 2008 guidelines) between March 2010 and March 2013 were analyzed retrospectively. SPT were carried out with the same panel, which included grass; weeds; trees; mold; epidermal mixtures; and with two house-dust mite (HDM) extracts, Dermatophagoides pteronyssinus and Dermatophagoides farinae.

RESULTS

In 1229 of 1457 patients (84.4%), there were positive reactions for at least one aeroallergen on the SPT. The most common aeroallergen was the HDM D. pteronyssinus (84% [n = 1033]) followed by D. farinae (78.2% [n = 962]). Grass pollen sensitivity (70.8% [n = 871]) was higher than tree or weed pollen sensitivity in this region.

CONCLUSIONS

The most common aeroallergens in AR are HDMs of D. pteronyssinus and D. farinae in the Eastern Black Sea region in Turkey. Our study may help in developing environmental control strategies for AR.

Important non-disease-related determinants of exhaled nitric oxide levels in mild asthma - results from the Swedish GA(2) LEN study

BACKGROUND

Fractional exhaled nitric oxide (FeNO) has a potential clinical role in asthma management. Constitutive factors such as age, height and gender, as well as individual characteristics, such as IgE sensitization and smoking, affect the levels of FeNO in population-based studies. However, their effect on FeNO in subjects with asthma has been scarcely studied.

OBJECTIVE

To study the effects on FeNO of these commonly regarded determinants, as demonstrated in healthy subjects, as well as menarche age and parental smoking, in a population of asthmatics.

MATERIAL AND METHODS

Fractional exhaled nitric oxide was measured in 557 subjects with asthma from the Swedish GA(2) LEN study. Allergic sensitization was assessed by skin prick tests to most common aeroallergens. Upper airway comorbidities, smoking habits, smoking exposure during childhood and hormonal status (for women) were questionnaire-assessed.

RESULTS

Male gender (P < 0.001), greater height (P < 0.001) and sensitization to both perennial allergens and pollen (P < 0.001) are related to higher FeNO levels. Current smoking (P < 0.001) and having both parents smoking during childhood, vs. having neither (P < 0.001) or only one parent smoking (P = 0.002), are related to lower FeNO. Women with menarche between 9 and 11 years of age had lower FeNO than those with menarche between 12 and 14 years of age (P = 0.03) or 15 and 17 years of age (P = 0.003).

CONCLUSIONS AND CLINICAL RELEVANCE

Interpreting FeNO levels in clinical practice is complex, and constitutional determinants, as well as smoking and IgE sensitisation, are of importance in asthmatic subjects and should be accounted for when interpreting FeNO levels. Furthermore, menarche age and parental smoking during childhood and their effects on lowering FeNO deserve further studies.

Asthma in the elderly: a different disease?

KEY POINTS

Asthma in the elderly can be difficult to identify due to modifications of its clinical features and functional characteristics.Several comorbidities are associated with asthma in the elderly, and this association differs from that observed in younger patients.In clinical practice, physicians should treat comorbidities that are correlated with asthma (i.e. rhinitis or gastro-oesophageal reflux), assess comorbidities that may influence asthma outcomes (i.e. depression or cognitive impairment) and try to prevent comorbidities related to -'drug-associated side-effects (i.e. cataracts, arrhythmias or osteoporosis)."Geriatric asthma" should be the preferred term because it implies the comprehensive and multidimensional approach to the disease in the older populations, whereas "asthma in the elderly" is only descriptive of the occurrence of the disease in this age range.

EDUCATIONAL AIMS

To present critical issues in performing differential diagnosis of asthma in the elderly.To offer the instrument to implement the management of asthma in the most advanced ages. Asthma is a chronic airway disease that affects all ages, but does this definition also include the elderly? Traditionally, asthma has been considered a disease of younger age, but epidemiological studies and clinical experience support the concept that asthma is as prevalent in older age as it is in the young. With the ever-increasing elderly population worldwide, the detection and proper management of the disease in old age may have a great impact from the public health perspective. Whether asthma in the elderly maintains the same characteristics as in young populations is an interesting matter. The diagnostic process in older individuals with suspected asthma follows the same steps, namely a detailed history supported by clinical examination and laboratory investigations; however, it should be recognised that elderly patients may partially lose reversibility of airway obstruction. The correct interpretation of spirometric curves in the elderly should take into account the physiological changes in the respiratory system. Several factors contribute to delaying the diagnosis of asthma in the elderly, including the age-related impairment in perception of breathlessness. The management of asthma in advanced age is complicated by the comorbidities and polypharmacotherapy, which advocate for a comprehensive approach with a multidimensional assessment. It should be emphasised that older age frequently represents an exclusion criterion for eligibility in clinical trials, and current asthma medications have rarely been tested in elderly asthmatics. Ageing is associated with pharmacokinetic changes of the medications. As a consequence, absorption, distribution, metabolism and excretion of antiasthmatic medications can be variably affected. Similarly, drug-to-drug interactions may reduce the effectiveness of inhaled medications and increase the risk of side-effects. For this reason, we propose the term "geriatric asthma" be preferred to the more generic "asthma in the elderly".

Diagnosis and treatment of allergic diseases in Zhejiang Province: a cross-sectional survey

BACKGROUND

The specialty of allergy developed quickly in western countries because of the rapid increase of allergic diseases, whereas it developed relatively slowly in China. The prevalence of allergen sensitization and allergic diseases in Zhejiang Province of China is high and improving the medical services for these diseases is critically needed.

OBJECTIVE

To investigate the working status of the diagnosis and treatment of allergic diseases, including doctor resources, diagnostic methods, and allergen-specific immunotherapy in patients of Zhejiang Province, and to provide instructions for the strategic development of subspecialties of allergic diseases.

METHODS

First we defined the doctors who treat allergic diseases, and designed a comprehensive questionnaire to collect personal and hospital information for these doctors. The questionnaires were distributed to hospitals with different ranks and from different areas in the province. The general condition of doctor's resources, carryout of diagnostic methods, and allergen-specific immunotherapy were described and variations in the different specialties, hospitals, and areas were further analyzed.

RESULTS

Doctors in their thirties with bachelor's degrees were the mainstream for diagnosing and treating allergic diseases. The main specialties of the doctor resources were the specialties of Ear, Nose and Throat (ENT), Respirology, Pediatrics, and Dermatology. The Pediatrics specialty had a more reasonable infrastructure of doctor resources with more young doctors working in this subspecialty. The development of allergy subspecialty varied within hospitals at different levels or from different areas. The carryout of the skin prick test (SPT), serum specific IgE (ssIgE), and subcutaneous immunotherapy (SCIT) was best performed in provincial hospitals, while sublingual immunotherapy (SLIT) was prescribed most commonly in municipal hospitals. The performance of SPT and ssIgE in Hangzhou, Jiaxing, and Wenzhou areas was much better than that in other places. The performance of SCIT and SLIT was best in Wenzhou.

CONCLUSIONS

Our survey revealed a very initial and unbalanced development for the allergy subspecialty in Zhejiang Province. Doctor resources for allergic diseases were mainly from the specialties of ENT, Respirology, and Pediatrics, and the performance of diagnosis and treatment was mainly focused on provincial and municipal hospitals. Continuous education of allergies could be extended to primary healthcare centers and more efforts should be directed to those areas with poor medical resources.

Pollen Allergens for Molecular Diagnosis

Pollen allergens are one of the main causes of type I allergies affecting up to 30% of the population in industrialized countries. Climatic changes affect the duration and intensity of pollen seasons and may together with pollution contribute to increased incidences of respiratory allergy and asthma. Allergenic grasses, trees, and weeds often present similar habitats and flowering periods compromising clinical anamnesis. Molecule-based approaches enable distinction between genuine sensitization and clinically mostly irrelevant IgE cross-reactivity due to, e. g., panallergens or carbohydrate determinants. In addition, sensitivity as well as specificity can be improved and lead to identification of the primary sensitizing source which is particularly beneficial regarding polysensitized patients. This review gives an overview on relevant pollen allergens and their usefulness in daily practice. Appropriate allergy diagnosis is directly influencing decisions for therapeutic interventions, and thus, reliable biomarkers are pivotal when considering allergen immunotherapy in the context of precision medicine.

Sensitization to common aeroallergens in a population of young adults in a sub-Saharan Africa setting: a cross-sectional study

BACKGROUND

Sensitization to aeroallergens increases the risk of developing asthma or allergic rhinitis. Data on sensitization to airborne allergens in the general population in sub-Saharan Africa are lacking. The aim of this study was to determine the prevalence and determinants of sensitization to common aeroallergens in a population of young adults.

METHODS

A cross-sectional study was conducted among students of the Faculty of Medicine and Pharmaceutical Sciences of the University of Douala between 1st February and 30th April 2014. We consecutively recruited all the students present in class or in hospital during our visit. They filled an anonymous questionnaire and underwent skin prick tests with common aeroallergens. A logistic regression model of the SPSS.20 software was used to investigate factors associated with sensitization to common aeroallergens.

RESULTS

Of the 600 students included in the study, 305 (50.8 %) were female. The mean age of participants was 22.6 ± 2.7 years. The prevalence of sensitization to aeroallergens was 42.8 % (95 % CI 38.8-46.8). Dermatophagoides pteronyssimus (24.2 %), Dermatophagoides farinae (22.8 %), Blomia tropicalis (23.3 %) and Blatella germanica (15.2 %) were the most common allergens found. Allergic rhinitis, asthma symptoms and family atopy were independently associated to sensitization to common aeroallergens.

CONCLUSION

A significant proportion of young adults are sensitized to common aeroallergens. Dust mites and cockroach should be included in the panel of aeroallergens in Cameroon.