Is exposure to pollen a risk factor for moderate and severe asthma exacerbations?

Limited number of studies have focused on the impact of pollen exposure on asthma. As a part of the EAACI Guidelines on Environment Science, this first systematic review on the relationship of pollen exposure to asthma exacerbations aimed to bridge this knowledge gap in view of implementing recommendations of prevention. We searched electronic iPubMed, Embase, and Web of Science databases using a set of MeSH terms and related synonyms and identified 73 eligible studies that were included for systemic review. When possible, meta-analyses were conducted. Overall meta-analysis suggests that outdoor pollen exposure may have an effect on asthma exacerbation, but caution is needed due to the low number of studies and their heterogeneity. The strongest associations were found between asthma attacks, asthma-related ED admissions or hospitalizations, and an increase in grass pollen concentration in the previous 2-day overall in children aged less than 18 years of age. Tree pollen may increase asthma-related ED visits or admissions lagged up to 7-day overall in individuals younger than 18 years. Rare data show that among subjects under 18 years of age, an exposure to grass pollen lagged up to 3 days may lower lung function. Further research considering effect modifiers of pollen sensitization, hay fever, asthma, air pollution, green spaces, and pre-existing medications is urgently warranted to better evaluate the impacts of pollen on asthma exacerbation. Preventive measures in relation to pollen exposure should be integrated in asthma control as pollen increase continues due to climate change.

Prioritizing Molecular Biomarkers in Asthma and Respiratory Allergy Using Systems Biology.

Highly prevalent respiratory diseases such as asthma and allergy remain a pressing health challenge. Currently, there is an unmet need for precise diagnostic tools capable of predicting the great heterogeneity of these illnesses. In a previous study of 94 asthma/respiratory allergy biomarker candidates, we defined a group of potential biomarkers to distinguish clinical phenotypes (i.e. nonallergic asthma, allergic asthma, respiratory allergy without asthma) and disease severity. Here, we analyze our experimental results using complex algorithmic approaches that establish holistic disease models (systems biology), combining these insights with information available in specialized databases developed worldwide. With this approach, we aim to prioritize the most relevant biomarkers according to their specificity and mechanistic implication with molecular motifs of the diseases. The Therapeutic Performance Mapping System (Anaxomics' TPMS technology) was used to generate one mathematical model per disease: allergic asthma (AA), non-allergic asthma (NA), and respiratory allergy (RA), defining specific molecular motifs for each. The relationship of our molecular biomarker candidates and each disease was analyzed by artificial neural networks (ANNs) scores. These analyses prioritized molecular biomarkers specific to the diseases and to particular molecular motifs. As a first step, molecular characterization of the pathophysiological processes of AA defined 16 molecular motifs: 2 specific for AA, 2 shared with RA, and 12 shared with NA. Mechanistic analysis showed 17 proteins that were strongly related to AA. Eleven proteins were associated with RA and 16 proteins with NA. Specificity analysis showed that 12 proteins were specific to AA, 7 were specific to RA, and 2 to NA. Finally, a triggering analysis revealed a relevant role for AKT1, STAT1, and MAPK13 in all three conditions and for TLR4 in asthmatic diseases (AA and NA). In conclusion, this study has enabled us to prioritize biomarkers depending on the functionality associated with each disease and with specific molecular motifs, which could improve the definition and usefulness of new molecular biomarkers.

Food allergy as an asthma comorbidity in children and adolescents: a practical approach through a real-world study.

INTRODUCTION: Several studies have shown interactions between food allergy (FA) and asthma, but the influence of FA in asthma traits has been scarcely studied. METHODS: A real-world retrospective observational study was conducted among patients between 3 and 18 years old referred to our Asthma Clinic from November 2014 to November 2017. Data were obtained from daily clinical practice. Only patients properly diagnosed with asthma and FA were included. RESULTS: 815 patients were included: 483 asthmatics and 332 non-asthmatics and 180 FA and 635 no FA. Food allergy was statistically more prevalent among asthma patients (p = 0.014). In a high pollen exposure area, Madrid, among subjects with asthma (121 FA, 362 no-FA), sensitization to lipid transfer protein (LTP) (p = 0.016, OR: 3.064, RR: 2.512) and pollen (p = 0.016, OR: 3.064, RR: 2.512) are risk factors to have a concomitant FA diagnosis, whereas sensitization to profilin is not. Peripheral blood eosinophils were higher in subjects with asthma and FA (≥450 eos/µL) than in asthmatics without FA (≤300 eos/µL) (p = 0.031). Blood eosinophilia, using a cut-off >300 eos/µL, was only present in the FA group. Therefore, this trait should be considered when phenotyping a patient as eosinophilic asthma. Sex had an impact on several variables: height, weight, BMI, blood eosinophils count, sensitization profile, and early-onset asthma. CONCLUSIONS: Asthma and FA are closely related and the presence of FA should be investigated in every asthma patient. This study shows an association between asthma with concomitant FA and sensitization to pollen and LTP, blood eosinophilia, and growth alterations. Differences between boys and girls were also described, so a sex-specific approach is recommended.

Consensus on the Clinical Approach to Moderate-to-Severe Atopic Dermatitis in Spain: A Delphi Survey.

BACKGROUND: The purpose of this study was to gather information on the current assessment and management of patients with moderate-to-severe AD in routine daily practice. METHODS: A cross-sectional two-round Delphi survey with the participation of dermatologists and allergologists throughout Spain was conducted. They completed a 46-item questionnaire, and consensus was defined when responses of ≥80% of participants coincided in the categories of a 5-point Likert scale for that item. RESULTS: A total of 105 specialists (aged 40-59 years) completed the two rounds. Participants agreed regarding the consideration of AD as a multifaceted disease and the differences in clinical presentation of AD according to the patient's age. It is recommendable to perform a skin biopsy to exclude early stage T-cell cutaneous lymphoma, psoriasis, or dermatitis herpetiformis, among others (99.1%). Also, consensus was reached regarding the use of the SCORAD index to quantify the severity of the disease (86.7%), the use of wet wraps to increase the effect of topical corticosteroids (90.4%), the usefulness of proactive treatment during follow-up (85.6%) and tacrolimus ointment (91.2%) to reduce new flares, and the fact that crisaborole is not the treatment of choice for severe AD (92.4%). AD was not considered a contraindication for immunotherapy in patients with allergic respiratory diseases (92.4%). In patients with severe AD, the use of immune response modifier drugs (97.6%) or phototherapy (92.8%) does not sufficiently cover their treatment needs. Consensus was also obtained regarding the role of the new biologic drugs (93.6%) targeting cytokines involved in the Th2 inflammatory pathway (92.0%) and the potential role of dupilumab as first-line treatment (90.4%) in moderate-to-severe AD patients. CONCLUSION: This study contributes a reference framework to the care of AD patients. There is no diagnostic test or biomarkers to direct treatment or to assess the severity of the disease, and many therapeutic challenges remain.

Therapeutic potential of peptides from Ole e 1 in olive-pollen allergy.

Olive-pollen allergy is one of the leading causes of respiratory allergy in Mediterranean countries and some areas of North America. Currently, allergen-specific immunotherapy is the only etiophatogenic treatment. However, this approach is not fully optimal, safe, or effective. Thus, efforts continue in the search for novel immunotherapy strategies, being one of the most promising the use of peptides derived from major allergens. This work tries to determine the therapeutic potential and safety of 5 dodecapeptides derived from the main allergen of olive-pollen allergy, Ole e 1. The immunomodulatory capacity of these peptides was studied using peripheral blood mononuclear cells (PBMCs) obtained from 19 olive-pollen-allergic patients and 10 healthy controls. We determined the capacity of these peptides to inhibit the proliferative response toward olive-pollen allergenic extract and to induce the regulatory cytokines, IL-10 and IL-35. To test the safety and absence of allergenicity of the peptides, the basophil activation was analyzed by flow-cytometry, using peripheral blood. The results showed that two of five peptides inhibited near to 30% the proliferative response against the total olive-pollen allergenic extract in olive-pollen-allergic patients. Inhibition increased to nearly 35% when the 5 peptides were used in combination. In both cases, a statistically significant induction of IL-10 and IL-35 secretion was observed in the supernatants of allergic patients PBMCs cultures. None of the 5 peptides induced basophil activation and cross-link inflammatory cell-bound IgE. In conclusion, these results open up new possibilities in the treatment of olive-pollen allergy, which could solve some of the problems facing current therapy approaches.

[Executive Summary of ARIA 2019: Integrated care pathways for allergic rhinitis in Argentina, Spain and Mexico]. / Resumen ejecutivo de ARIA 2019: Vías integradas de atención para la rinitis alérgica en Argentina, España y México.

The health and economic impact of allergic diseases are increasing rapidly, and changes in management strategies are required. Its influence reduces the capacity of work and school performance by at least a third. The ICPs of the airways (integrated care pathways for respiratory diseases) are structured multidisciplinary healthcare plans, promoting the recommendations of the guidelines in local protocols and their application to clinical practice. This document presents an executive summary for Argentina, Mexico, and Spain. Next-generation ARIA guidelines are being developed for the pharmacological treatment of allergic rhinitis (AR), using the GRADE-based guidelines for AR, tested with real-life evidence provided by mobile technology with visual analogue scales. It is concluded that in the AR treatment, H1-antihistamines are less effective than intranasal corticosteroids (INCS), in severe AR the INCS represent the first line of treatment, and intranasal combination INCS + anti-H1 is more effective than monotherapy. However, according to the MASK real-life observational study, patients have poor adherence to treatment and often self-medicate, according to their needs.

El impacto sanitario y económico de las enfermedades alérgicas está aumentando rápidamente y se necesitan cambios en las estrategias para su manejo. Su influencia reduce al menos en un tercio la capacidad de desempeño laboral y escolar. Los ICP (Vías Integradas de Atención) de las enfermedades de las vías respiratorias son planes de atención estructurados y multidisciplinarios, que promueven las recomendaciones de las guías en protocolos locales y su aplicación a la práctica clínica. En este documento se presenta un resumen ejecutivo para Argentina, México y España. Se desarrollan las guías ARIA de próxima generación para el tratamiento farmacológico de la rinitis alérgica (RA) utilizando las pautas basadas en GRADE para RA, probadas con evidencia de la vida real proporcionada por tecnología móvil basada en escalas visuales analógicas. Se concluye que en el tratamiento de la RA, los antihistamínicos anti-H1 son menos efectivos que los corticoides intranasales (CINS), que en la rinitis gravelos CINS representan la primera línea de tratamiento, y que la combinación intranasal de CINS + anti-H1 es más eficaz que la monoterapia. Sin embargo, según el estudio MASK observacional en vida real, los pacientes tienen pobre adherencia al tratamiento y frecuentemente se automedican de acuerdo con sus necesidades.

Molecular diagnosis and immunotherapy.

PURPOSE OF REVIEW: To describe recent insights into how molecular diagnosis can improve indication and selection of suitable allergens for specific immunotherapy and increase the safety of this therapy. RECENT FINDINGS: As specific allergen immunotherapy targets specific allergens, identification of the disease-eliciting allergen is a prerequisite for accurate prescription of treatment. In areas of complex sensitization to aeroallergens or in cases of hymenoptera venom allergy, the use of molecular diagnosis has demonstrated that it may lead to a change in indication and selection of allergens for immunotherapy in a large proportion of patients when compared with diagnosis based on skin prick testing and/or specific IgE determination with commercial extracts. These changes in immunotherapy prescription aided by molecular diagnosis have been demonstrated to be cost-effective in some scenarios. Certain patterns of sensitization to grass or olive pollen and bee allergens may identify patients with higher risk of adverse reaction during immunotherapy. SUMMARY: Molecular diagnosis, when used with other tools and patients' clinical records, can help clinicians better to select the most appropriate patients and allergens for specific immunotherapy and, in some cases, predict the risk of adverse reactions. The pattern of sensitization to allergens could potentially predict the efficacy of allergen immunotherapy provided that these immunotherapy products contain a sufficient amount of these allergens. Nevertheless, multiplex assay remains a third-level approach, not to be used as screening method in current practice.

Comparison of allergenic extracts from different origins: the value of the FDA's bioequivalent allergy unit (BAU).

INTRODUCTION: Allergy immunotherapy (AIT) is the only disease-modifying intervention for the treatment of allergic diseases. The clinical effectiveness of AIT is clearly dose-dependent, so it is important that clinicians can assess and compare the potency of the various products available. However, this is not possible in practice, because manufacturers use different methods to determine potency. Therefore, a clear need exists for adoption of a 'gold-standard' measure of allergenicity. The bioequivalent allergy unit (BAU) is thus far the only allergen unit approved by a regulatory agency (the US Food and Drug Administration), with European regulatory authorities yet to adopt a common unit. AREAS COVERED: Using PubMed, we performed a review of the literature on measures of allergen extract potency, use of the BAU, and BAU assessment for grass pollen tablets. Expert commentary: There is an obvious benefit to allergists and patients for having a single, comparable unit across products, and we strongly support the adoption of a single, 'gold-standard' unit of measurement for all products. Use of the BAU allows a clear comparison of the potency of allergen products from different manufacturers, and enables better understanding of the potential reasons for any differences in administration and dosing protocols between these products.

Analysis of comorbidities and therapeutic approach for allergic rhinitis in a pediatric population in Spain.

BACKGROUND: Allergic rhinitis (AR) is the most common chronic disease in children. The main objective of this study was to analyze the comorbidities and therapeutic approaches for AR in a Spanish pediatric population. METHODS: Children aged 6 to 12 years with AR were included in an observational, cross-sectional, multicenter study. RESULTS: 1,275 children were recruited from 271 centers. AR was intermittent in 59.5% of cases, persistent in 40.5%, seasonal in 60.7%, and perennial in 39.3% of patients. The most frequent comorbidities were conjunctivitis (53.6%), asthma (49.5%), atopic dermatitis (40%), rhinosinusitis(26.1%), otitis media (23.8%), and adenoid hypertrophy (17.3%). Overall, patients with persistent, moderate or severe, AR were more likely to present comobidities, except for food allergy and urticaria. The most common drugs used for treatment of AR were oral antihistamines(76%), nasal corticosteroids(49%) and a combination of both (45%). Antihistamines and nasal corticosteroids were used on demand (<18 days) in 38 and 41% of patients, respectively; for 18-30 days in 22 and 27%; for 1-3 months in 31 and 29%; and for more than 3 months in 8 and 3%, respectively. Eye drops were used in 32% and specific immunotherapy in 21% of patients. CONCLUSION: Comorbidities are frequent in children with AR, supporting the notion of allergy as a systemic disease. Severity and duration of AR were significantly associated with presence of most of comorbidities. The most common drugs used for AR treatment were oral antihistamines, followed by nasal corticosteroids and a combination of both used on demand.

Validation of ARIA (Allergic Rhinitis and its Impact on Asthma) classification in a pediatric population: the PEDRIAL study.

Allergic rhinitis (AR) is the commonest chronic disease in children. Allergic Rhinitis and its Impact on Asthma (ARIA) classification based on symptom duration (intermittent vs. persistent) and severity (mild vs. moderate/severe) has not been yet validated in children. Thus our objective was to validate ARIA classification in children, after determining the severity and duration of AR in a pediatric population, using ARIA definitions. Children aged 6-12 with a diagnosis of AR were included in an observational, cross-sectional, multicenter study. Patients were classified according to ARIA guidelines. AR symptoms were assessed using the Total Four Symptoms Score (T4SS). Severity was also evaluated by the patient using a visual analogue scale (VAS). Comparisons were made by means of a statistical analysis. One thousand two hundred and seventy-five children from 271 centers were included. Among them, 59.5% had intermittent and 40.5% persistent AR, while 60.7% seasonal and 39.3% perennial according to dated classification, with significant differences existing between one classification and another; 89.7% had moderate/severe rhinitis. Significantly higher T4SS and VAS scores were obtained in moderate/severe compared to mild AR. In our experience, the current ARIA classification can be considered a valid tool also in children from 6- to 12-yr old.

Molecular cloning and characterization of Cup a 4, a new allergen from Cupressus arizonica.

Sensitization to Cupressaceae pollen has become one of the most important causes of pollinosis in Western countries during winter and early spring. However, the characterization of the extracts, the allergens involved and the cross-reactivity with other pollen sources still remain poorly studied; in the case of Cupressus arizonica only two allergens have been described so far. A new allergen from C. arizonica pollen, Cup a 4, was cloned and expressed in Escherichia coli as an N-terminally His-tag recombinant protein that was characterized biochemically, immunologically and by circular dichroism spectroscopy. The new allergen has high sequence identity with Prickly Juniper allergen Jun o 4 and contains four EF-hand domains. The recombinant protein has structural similarities with other calcium binding allergens such as Ole e 3, Ole e 8 and Phl p 7. Cup a 4 is expressed in mature pollen grains and shares antigenic properties with the recombinant form. Sera from 9.6% C. arizonica allergic patients contain specific IgE antibodies against recombinant Cup a 4.

Allergy to kiwi in patients with baker's asthma: identification of potential cross-reactive allergens.

BACKGROUND: Baker's asthma is a frequent IgE-mediated occupational disorder mainly provoked by inhalation of cereal flour. Allergy to kiwifruit has being increasingly reported in the past few years. No association between both allergic disorders has been described so far. METHODS: Twenty patients with occupational asthma caused by wheat flour inhalation were studied. Kiwi allergens Act d 1 and Act d 2 were purified by cation-exchange chromatography. Wheat, rye, and kiwi extracts, purified kiwi allergens, and model plant glycoproteins were analyzed by IgE immunodetection, enzyme-linked immunosorbent assay (ELISA), and inhibition ELISAs. RESULTS: Kiwifruit ingestion elicited oral allergy syndrome in 7 of the 20 patients (35%) with baker's asthma. Positive specific IgE and skin prick test responses to this fruit were found in all these kiwi allergic patients, and IgE to Act d 1 and Act d 2 was detected in 57% and 43%, respectively, of the corresponding sera. Actinidin Act d 1 and bromelain (harboring cross-reactive carbohydrate determinants) reached above 50% inhibition of the IgE binding to wheat and/or kiwi extracts. CONCLUSIONS: A potential association between respiratory allergy to cereal flour and allergy to kiwifruit has been disclosed. Cross-reactive carbohydrate determinants and thiol-proteaseshomologous to Act d 1 are responsible for wheat-kiwi crossreactivity in some patients.

Hypersensitivity to black locust (Robinia pseudoacacia) pollen: "allergy mirages".

BACKGROUND: The allergenicity of the ornamental tree Robinia pseudoacacia, or black locust, is unknown. OBJECTIVE: To evaluate the prevalence of sensitization to R. pseudoacacia pollen, its possible allergenic cross-reactivity with other common pollens, and the potential implication of pollen panallergens (profilin, polcalcin, and 1,3-beta-glucanase) as a cause of sensitization to R. pseudoacacia pollen. METHODS: Skin prick testing with R. pseudoacacia pollen was performed in 149 patients with pollinosis. Nasal challenge with R. pseudoacacia pollen was performed in 10 patients. The prevalence of sensitization to the recombinant forms of profilin (rChe a 2), polcalcin (rChe a 3), and the N-terminal of the 1,3-beta-glucanase (rNtD of Ole e 9) was investigated. Immunoblotting, enzyme-linked immunosorbent assay, and competitive inhibition assays were performed with R. pseudoacacia pollen and recombinant pollen allergens. RESULTS: Sixty-four patients (43%) had positive skin prick test reactions to R. pseudoacacia pollen. Nasal challenge results were positive in 5 sensitized patients and negative in 4 controls and 1 sensitized patient. The allergenic profile of R. pseudoacacia pollen comprises at least the panallergen profilin, a calcium-binding protein, and a 1,3-beta-glucanase. The prevalence of sensitization to rChe a 2, rChe a 3, and rNtD of Ole e 9 was 60%, 33%, and 87%, respectively, among patients sensitized to R. pseudoacacia pollen. Binding of IgE to R. pseudoacacia extract was completely inhibited by Robinia, Chenopodium, Olea, Cupressus, and Lolium extracts. CONCLUSIONS: The high prevalence of R. pseudoacacia pollen sensitization in patients with pollinosis is likely to be due to cross-sensitization to panallergens (profilin, polcalcin, and 1,3-beta-glucanase) from other common pollens. This phenomenon may lead to a diagnosis of "allergy mirages."

Asma relacionada con la inhalación de Plantago ovata / Asthma related to inhalation of Plantago ovata

FUNDAMENTOS: El psyllium, obtenido de semillas de Plantago ovata, se utiliza como laxante de volumen. Se ha descrito que puede actuar como un alergeno por vía inhalatoria, fundamentalmente en el medio laboral. Presentamos un caso clínico de asma por semillas de P. ovata, destacando el potencial alergénico de esta sustancia de uso frecuente como laxante. Se trata de una paciente de 31 años de edad, fumadora y atópica, que desde hacía unos 3 años preparaba y administraba en su domicilio, a su madre incapacitada, dos sobres diarios de un laxante con semillas de P. ovata (Plantaben®). MÉTODOS Y RESULTADOS: Se realizaron pruebas cutáneas de hipersensibilidad inmediata (prick) con un extracto de psyllium, resultando positivas. Se detectó IgE específica a P. ovata mediante técnica ELISA. El test de inhalación bronquial con metacolina reveló una hiperreactividad bronquial leve (PC20 = 1,5 mg/ml). En el test de provocación bronquial específico con psyllium se obtuvo una respuesta inmediata. Los alergenos responsables se identificaron mediante SDSPAGE e inmunoblot, observándose varios componentes alergénicos con pesos moleculares aparentes de 66 kDa, 60 kDa, entre 36-20 kDa y de 14 kDa. Se investigó si existía reactividad cruzada con el polen de Plantago lanceolata, lo que se descartó mediante ensayo de ELISA-inhibición. CONCLUSIONES: El psyllium puede actuar como un potente alergeno capaz de causar asma, no sólo en el medio laboral, sino también en ambiente doméstico a los propios consumidores del laxante o a los familiares que los dispensan (AU)