Allergic respiratory disease: Different allergens, different symptoms

The Significance of Fractional Exhaled Nitric Oxide, Fractional Nasal Exhaled Nitric Oxide and Lung Function Tests in Children with Moderate-to-Severe Allergic Rhinitis

PURPOSE

Fractional nasal exhaled NO (FnNO), fractional exhaled NO (FeNO) and lung function tests were performed in children with moderate-to-severe persistent allergic rhinitis (AR) to investigate the significance of the above indices in the assessment and diagnosis of children with AR.

METHODS

A total of 135 children with persistent AR were selected and divided into moderate-to-severe and mild groups; serum total immunoglobulin E (IgE), peripheral blood eosinophil counts (EOS), FnNO, FeNO, and lung function tests were performed.

RESULTS

Children in the moderate-to-severe group had increased levels of FnNO and FeNO and decreased levels of forced expiratory flow at 75% of forced vital capacity as a percentage of the predicted value (FEF75%) and maximum mid-term expiratory flow as a percentage of the predicted value (MMEF%) . IgE in children with AR was positively correlated with FeNO and FnNO and negatively correlated with FEF75% . EOS was positively correlated with FnNO. FeNO was negatively correlated with FEF75% and forced expiratory flow at 50% of forced vital capacity as a percentage of the predicted value (FEF50%). FnNO was negatively correlated with FEF75%, FEF50%, and MMEF%.

CONCLUSION

FnNO, FeNO, and pulmonary function tests may help assess disease severity and level of disease control in children with persistent AR.

Link between gut microbiota dysbiosis and childhood asthma: Insights from a systematic review

Asthma, a chronic inflammatory disorder of the airways, is a prevalent childhood chronic disease with a substantial global health burden. The complex etiology and pathogenesis of asthma involve genetic and environmental factors, posing challenges in diagnosis, severity prediction, and therapeutic strategies. Recent studies have highlighted the significant role of the gut microbiota and its interaction with the immune system in the development of asthma. Dysbiosis, an imbalance in microbial composition, has been associated with respiratory diseases through the gut-lung axis. This axis is an interaction between the gut and lungs, allowing microbial metabolites to influence the host immune system. This systematic review examines the association between gut microbiota composition, measured using 16S rRNA sequencing, during infancy and childhood, and the subsequent development of atopic wheeze and asthma. The results suggest that higher alpha diversity of bacteria such as Bifidobacterium, Faecalibacterium, and Roseburia may have protective effects against asthmatic outcomes. Conversely, lower relative abundances of bacteria like Bacteroides and certain fungi, including Malassezia, were associated with asthma. These findings highlight the potential of early screening and risk assessment of gut microbiota to identify individuals at risk of asthma. Furthermore, investigations targeting gut microbiota, such as dietary modifications and probiotic supplementation, may hold promise for asthma prevention and management. Future research should focus on identifying specific microbial signatures associated with asthma susceptibility and further investigate approaches like fecal microbiota transplantation. Understanding the role of gut microbiota in asthma pathogenesis can contribute to early detection and development of interventions to mitigate the risk of asthmatic pathogenesis in childhood.

Outdoor aeroallergen impacts on asthma exacerbation among sensitized and nonsensitized Philadelphia children

Background

Outdoor aeroallergens, such as pollens and molds, are known triggers of asthma exacerbation; however, few studies have examined children's aeroallergen response based on sensitization.

Objective

Our aim was to compare the relative impact of aeroallergen levels on asthma exacerbation between pediatric patients with asthma who tested positive or negative for sensitization to particular allergens.

Methods

A case-crossover design study was conducted to examine associations between outdoor aeroallergen levels and asthma exacerbation events among children living in Philadelphia, Pennsylvania, who were treated within a large pediatric care network. Sensitization to common allergens was characterized in a subset of patients with asthma exacerbation who had undergone skin prick testing (5.5%). Odds ratios (ORs) and 95% CIs were estimated in all patients with asthma exacerbation and in those sensitized or not sensitized to aeroallergens.

Results

Children who were sensitized to a particular allergen had higher odds of asthma exacerbation with exposure to the allergen (ie, early-season tree pollen, oak tree pollen, early-season weed pollen, and late-season molds) than did all patients with asthma or nonsensitized patients. For example, the association between early-season tree pollen and asthma exacerbation among sensitized children (>90th percentile vs ≤25th, OR = 2.28 [95% CI = 1.23-4.22]) was considerably stronger than that estimated among all patients (OR = 1.34 [95% CI = 1.19-1.50]), and it was also substantially different from the lack of association seen among nonsensitized children (OR = 0.89 [95% CI = 0.51-1.55] [P value for heterogeneity = .03]).

Conclusion

More prevalent allergy testing may be useful for prevention of asthma exacerbation by informing interventions targeted to sensitized children and tailored for particular aeroallergens.

Polysensitisation is associated with more severe symptoms: The reality of patients with allergy

BACKGROUND

Studying the sensitisation profiles of patients with allergies allows for a deeper understanding of the disease which may facilitate the selection of the best-personalised allergen immunotherapy. This observational, cross-sectional, multicentre study aimed to demonstrate the heterogeneity of the German population with allergies by analysing specific immunoglobulin E (sIgE) patterns towards aeroallergens and exploring the relationship between sensitisation and clinical symptoms.

METHODS

In total, 500 patients with allergies from different regions of Germany were recruited based on their case histories, clinical allergic symptoms and skin prick test data for aeroallergens. Serum samples were analysed using ImmunoCAP assays to determine sIgE levels for 33 allergenic sources and 43 molecular allergens.

RESULTS

Most patients (81%) were polysensitised. Betula verrucosa pollen was the most common cause of sensitisation (59%), followed by Phleum pratense (58%) and Dermatophagoides pteronyssinus (44%). The highest prevalence rates of molecular allergens were observed for Bet v 1 (84%) from birch pollen, Phl p 1 from grass pollen (82%), Der p 2 (69%) from mites and Fel d 1 (69%) from cat. Polysensitisation was significantly associated with the presence of asthma and the severity of rhinitis symptoms.

CONCLUSIONS

Our findings show a high rate of polysensitisation and emphasise the importance of molecular diagnosis for more precise and comprehensive insights into sensitisation patterns and their association with clinical symptoms. These data may help improve personalised diagnosis and immunotherapy adapted to the needs of individual patients in the region.

AIM2 participates in house dust mite (HDM)-induced epithelial dysfunctions and ovalbumin (OVA)-induced allergic asthma in infant mice

Objective: Allergen sensitization and high rates of concomitant allergic diseases are characteristic of severe pediatric asthma. The present study was aimed to explore the mechanism of allergic asthma via bioinformatics and experiment investigation. Methods: The GSE27011 dataset contained the expression profiles of normal and pediatric asthma white blood cells was downloaded for analyzing the different expression genes and function enrichment. The allergic asthma model in infant mice was established by ovalbumin (OVA) stimulation. The cellular model was established by house dust mite (HDM)-stimulation in human bronchial epithelial cells. The absent in melanoma 2 (AIM2) knockdown was achieved by intranasal lentivirus injection or cell infection. The bronchoalveolar lavage fluid (BALF) was collected for cell counting and ELISA assessment of cytokines. Lung tissues were collected for HE staining and immunohistochemical (IHC) staining. Real-time PCR and immunoblotting were used for the determination of key gene expressions in mouse and cell models. Results: upregulation of AIM2 gene expression was observed in pediatric asthma patients based on GSE27011 and OVA-induced infant mouse allergic asthma model. AIM2 knockdown ameliorated OVA caused elevation in airway hyper-responsiveness (AHR), elevation in cell quantities (eosinophils, neutrophils, lymphocytes), and levels of cytokines (IL-4, IL-13, TNF-α, and OVA-specific IgE) in BALF. Moreover, AIM2 knockdown relieved OVA-caused histopathological alterations in mouse lungs, up-regulation of AIM2 levels, and NOD1 and receptor-interacting protein 2 (RIP2) protein levels, as well as p65 phosphorylation. In the cell model, AIM2 knockdown partially ameliorated HDM-induced epithelial dysfunctions by promoting cell viability, down-regulating inflammatory cytokines levels, and decreasing the protein levels of AIM2, NOD1, RIP2, and phosphorylated p65. Conclusion: AIM2 participates in HDM-induced epithelial dysfunctions and OVA-induced allergic asthma progression. AIM2 could be a promising target for pediatric allergic asthma treatment regimens, which warrants further in vivo investigations.

Bronchial Asthma, Airway Remodeling and Lung Fibrosis as Successive Steps of One Process

Bronchial asthma is a heterogeneous disease characterized by persistent respiratory system inflammation, airway hyperreactivity, and airflow obstruction. Airway remodeling, defined as changes in airway wall structure such as extensive epithelial damage, airway smooth muscle hypertrophy, collagen deposition, and subepithelial fibrosis, is a key feature of asthma. Lung fibrosis is a common occurrence in the pathogenesis of fatal and long-term asthma, and it is associated with disease severity and resistance to therapy. It can thus be regarded as an irreversible consequence of asthma-induced airway inflammation and remodeling. Asthma heterogeneity presents several diagnostic challenges, particularly in distinguishing between chronic asthma and other pulmonary diseases characterized by disruption of normal lung architecture and functions, such as chronic obstructive pulmonary disease. The search for instruments that can predict the development of irreversible structural changes in the lungs, such as chronic components of airway remodeling and fibrosis, is particularly difficult. To overcome these challenges, significant efforts are being directed toward the discovery and investigation of molecular characteristics and biomarkers capable of distinguishing between different types of asthma as well as between asthma and other pulmonary disorders with similar structural characteristics. The main features of bronchial asthma etiology, pathogenesis, and morphological characteristics as well as asthma-associated airway remodeling and lung fibrosis as successive stages of one process will be discussed in this review. The most common murine models and biomarkers of asthma progression and post-asthmatic fibrosis will also be covered. The molecular mechanisms and key cellular players of the asthmatic process described and systematized in this review are intended to help in the search for new molecular markers and promising therapeutic targets for asthma prediction and therapy.

[Unmet Needs in Severe Allergic Asthma]

Severe asthma affects 3%-10% of the world's population, according to estimates by the Global Initiative for ASTHMA (GINA). Allergic asthma is one of the most common phenotypes of severe asthma and it is characterized by allergen-induced type 2 inflammation in which immunoglobulin E (IgE) is a key mediator, making it an important therapeutic target. The introduction of targeted biological therapies or treatments has entered the management for severe asthma in the era of precision medicine, and the goal of treatment is clinical remission of the disease. There is a significant percentage of patients with severe allergic asthma who do not respond to treatments and whose symptoms are not controlled. In this paper, a group of experts in the management of severe allergic asthma reviewed and evaluated the most relevant evidence regarding the pathophysiology and phenotypes of severe allergic asthma, the role of IgE in allergic inflammation, allergen identification, techniques, biomarkers and diagnostic challenges, available treatments and strategies for disease management, with a special focus on biological treatments. From this review, recommendations were developed and validated through a Delphi consensus process with the aim of offering improvements in the management of severe allergic asthma to the professionals involved and identifying the unmet needs in the management of this pathology.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Omics technologies in allergy and asthma research: An EAACI position paper

Allergic diseases and asthma are heterogenous chronic inflammatory conditions with several distinct complex endotypes. Both environmental and genetic factors can influence the development and progression of allergy. Complex pathogenetic pathways observed in allergic disorders present a challenge in patient management and successful targeted treatment strategies. The increasing availability of high-throughput omics technologies, such as genomics, epigenomics, transcriptomics, proteomics, and metabolomics allows studying biochemical systems and pathophysiological processes underlying allergic responses. Additionally, omics techniques present clinical applicability by functional identification and validation of biomarkers. Therefore, finding molecules or patterns characteristic for distinct immune-inflammatory endotypes, can subsequently influence its development, progression, and treatment. There is a great potential to further increase the effectiveness of single omics approaches by integrating them with other omics, and nonomics data. Systems biology aims to simultaneously and longitudinally understand multiple layers of a complex and multifactorial disease, such as allergy, or asthma by integrating several, separated data sets and generating a complete molecular profile of the condition. With the use of sophisticated biostatistics and machine learning techniques, these approaches provide in-depth insight into individual biological systems and will allow efficient and customized healthcare approaches, called precision medicine. In this EAACI Position Paper, the Task Force "Omics technologies in allergic research" broadly reviewed current advances and applicability of omics techniques in allergic diseases and asthma research, with a focus on methodology and data analysis, aiming to provide researchers (basic and clinical) with a desk reference in the field. The potential of omics strategies in understanding disease pathophysiology and key tools to reach unmet needs in allergy precision medicine, such as successful patients' stratification, accurate disease prognosis, and prediction of treatment efficacy and successful prevention measures are highlighted.

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.

Associations of sleep problems with asthma and allergic rhinitis among Chinese preschoolers

The aim of this study was to examine the associations of sleep problems with asthma and allergic rhinitis among Chinese preschoolers. This cross-sectional survey was conducted in Guangzhou, China. Children aged 3–6 years were recruited from 32 kindergartens in 7 administrative districts. Asthma, allergic rhinitis and sleep problems were evaluated using a valid questionnaire. Binary logistic regression models were employed to estimate the odds ratios (OR) and 95% confidence intervals (CI) for the associations of asthma and allergic rhinitis with short sleep duration, late bedtime and frequent nocturnal awakening. We included 4876 preschool children in the current analysis. Of these, 182 (3.7%) diagnosed as asthma, and 511 (10.5%) diagnosed as allergic rhinitis. Frequent nocturnal awakening was associated with asthma and allergic rhinitis, with adjusted OR were 1.49 (95% CI 1.05–2.13) and 1.59 (95% CI 1.27–1.99), respectively. Subgroup analysis showed the OR for frequent nocturnal awakening with asthma was higher in girls (1.68; 95% CI 1.02–2.78) than in boys (1.35; 95% CI 0.81–2.24), but the OR for frequent nocturnal awakening with allergic rhinitis were similar in girls (1.73; 95% CI 1.15–2.30) and boys (1.57; 95% CI 1.17–2.12). No significant associations of short sleep duration and late bedtime with asthma or allergic rhinitis were identified. Our data suggested that frequent nocturnal awakening was associated with asthma and allergic rhinitis among preschoolers, and the association of frequent nocturnal awakening with asthma differed by gender. Further studies are warranted to address the causal relationship between nocturnal awakening and asthma and allergic rhinitis.

Clinical features and nasal inflammation in asthma and allergic rhinitis

Asthma and allergic rhinitis (AR) are widely considered to be the most common chronic inflammatory disorders. This study was performed to investigate the clinical features, disease severity, and upper airway inflammation among patients with asthma, AR, and asthma comorbid AR. Blood and nasal lavage fluid samples were collected from patients with isolated asthma (n = 23), isolated AR (n = 22), and asthma comorbid AR (n = 22). Demographic data, symptom evaluation, and spirometry were obtained from all subjects. The levels of interleukin (IL)-4, IL-5, IL-13, IL-17, IL-25, IL-33, and S100 proteins were measured in the nasal lavage fluid. Compared with isolated asthma, patients with asthma comorbid AR showed a lower quality of life according to the asthma quality-of-life questionnaire (AQLQ) score (6.11 ± 0.47 vs. 6.45 ± 0.35, P = 0.007). Additionally, no significant difference in the levels of IL-4 (P = 0.116), IL-25 (P = 0.235), and S100A12 (P = 0.392) was observed in nasal lavage fluid among three groups. However, miniscule levels of IL-5, IL-17, IL-13, IL-33, S100A8, and S100A9 were detected in nasal lavage fluid in all three groups. Patients with asthma comorbid AR showed an increased level of systemic cytokine in plasma than that of patients with isolated AR or asthma alone. The finding from our study may help clinicians to better understand the airway inflammation among asthma patients with or without AR.

Candida-induced asthma steps up to the plate-lets

Fungal proteases are well-known allergens. In this issue of Immunity, Wu et al. (2021) observe that allergic airway responses to Candida albicans are mediated by the peptide toxin candidalysin rather than proteases. Candidalysin promotes these responses by stimulating platelets to release the Wnt antagonist Dickkopf-1.

Alternaria as an Inducer of Allergic Sensitization

Alternaria alternata is a saprophytic mold whose spores are disseminated in warm dry air, the typical weather of the Mediterranean climate region (from 30° to 45°), with a peak during the late summer and early autumn. Alternaria spores are known to be biological contaminants and a potent source of aeroallergens. One consequence of human exposure to Alternaria is an increased risk of developing asthma, with Alt a 1 as its main elicitor and a marker of primary sensitization. Although the action mechanism needs further investigation, a key role of the epithelium in cytokine production, TLR-activated alveolar macrophages and innate lymphoid cells in the adaptive response was demonstrated. Furthermore, sensitization to A. alternata seems to be a trigger for the development of co-sensitization to other allergen sources and may act as an exacerbator of symptoms and an elicitor of food allergies. The prevalence of A. alternata allergy is increasing and has led to expanding research on the role of this fungal species in the induction of IgE-mediated respiratory diseases. Indeed, recent research has allowed new perspectives to be considered in the assessment of exposure and diagnosis of fungi-induced allergies, although more studies are needed for the standardization of immunotherapy formulations.

The dual function of ILC2: From host protection to pathogenic players in type 2 asthma

Innate lymphoid cells type 2 (ILC2) are considered the innate counterpart of Th2 cells and cooperate with them in host protection against helminths and in the pathogenesis of allergic diseases. ILC2 are characterized by type 2 cytokines production (IL-13, IL-4 and IL-5) and by GATA-3 transcription factor expression. Belonging to innate immune system, ILC2 lack of antigen specific receptor and their activation is controlled mainly by epithelial derived cytokines, such as TSLP, IL-25, and IL-33. ILC2 are located in a strategic position in the airway mucosa and are important to patrol the airways, to recruit other immune system cells and to activate resident cells in response to pathogens injury and/or tissue damage. In the last decade, many studies, in both humans and mice, focused on ILC2, fully investigating their main features such as the development from the precursor, the stimuli for their activation or inhibition, their plasticity, their classification in different subsets, and finally, their pathogenetic role in type 2 immune-mediated disorders. In this review we performed an excursus on phenotypical and functional properties on both human and mouse ILC2, in physiological and pathological conditions (mainly in type 2 asthma), considering this cell subset as target for specific therapeutic strategies.

Total IgE Variability Is Associated with Future Asthma Exacerbations: A 1-Year Prospective Cohort Study

BACKGROUND

Few prospective studies have investigated the relationship between IgE variability and risk for asthma exacerbations (AEs).

OBJECTIVE

To explore the relationship between IgE variability and AEs.

METHODS

Recruited patients with stable asthma underwent two serum total IgE tests within a month (at screening [baseline IgE] and at 1 month) to obtain the coefficient of variation (CV) of base 10 log-transformed IgE. Patients with IgE CV were divided into IgE CV-high and IgE CV-low cohorts based on the CV median and were observed within 12 months, during which the association between IgE variability and AEs was explored using a negative binomial regression model.

RESULTS

The IgE CV levels obtained from 340 patients classified patients into two groups (n = 170 for the IgE CV-high and IgE CV-low groups, respectively) based on the serum total IgE CV median of 2.12% (quartiles 1 and 3: 0.98% and 3.91%, respectively). The IgE CV-high patients exhibited worse asthma control and lung function and more marked airway inflammation, and received more intensive medication use compared with IgE CV-low patients. The IgE CV-high patients exhibited increased rates of moderate-to-severe (adjusted rate ratio = 2.88; 95% confidence interval, 1.65-5.03; P < .001) and severe (adjusted rate ratio = 2.16; 95% confidence interval, 1.08-4.32; P = .029) AEs during the follow-up year compared with IgE CV-low patients. Furthermore, sputum IL-6 partially mediated the associations between IgE CV with moderate-to-severe and severe AEs.

CONCLUSIONS

Variability in total serum IgE levels is an easily obtained and practical measure for predicting AEs. Future studies are needed to investigate whether IgE variability can be used to guide precision medicine in asthma.

Recent Advances in Allergen-Specific Immunotherapy as Treatment for Allergic Asthma: A Practical Overview

The Global Initiative for Asthma Report updated in 2019 stated that potential benefits of allergen immunotherapy (AIT), compared to pharmacological and avoidance options, must be weighed against the risk of adverse effects and the inconvenience and cost of the prolonged course of therapy in asthma. Thus, with the aim of clarifying some aspects with regard to the possible use of AIT in allergic asthma treatment armamentarium, a group of expert allergists from the Spanish Allergy and Clinical Immunology Scientific Society (SEAIC), particularly from the Immunotherapy and Asthma Interest Groups developed a frequently asked questions in clinical practice. This document updates relevant topics on the use of AIT in asthma and could facilitate physician clinical decisions and improve health outcomes for individual patients.

New perspectives in bronchial asthma: pathological, immunological alterations, biological targets, and pharmacotherapy

Asthma is the most common, long-lasting inflammatory airway disease that affects more than 10% of the world population. It is characterized by bronchial narrowing, airway hyperresponsiveness, vasodilatation, airway edema, and stimulation of sensory nerve endings that lead to recurring events of breathlessness, wheezing, chest tightness, and coughing. It is the main reason for global morbidity and occurs as a result of the weakening of the immune system in response to exposure to allergens or environmental exposure. In asthma condition, it results in the activation of numerous inflammatory cells like the mast and dendritic cells along with the accumulation of activated eosinophils and lymphocytes at the inflammation site. The structural cells such as airway epithelial cells and smooth muscle cells release inflammatory mediators that promote the bronchial inflammation. Long-lasting bronchial inflammation can cause pathological alterations, viz. the improved thickness of the bronchial epithelium and friability of airway epithelial cells, epithelium fibrosis, hyperplasia, and hypertrophy of airway smooth muscle, angiogenesis, and mucus gland hyperplasia. The stimulation of bronchial epithelial cell would result in the release of inflammatory cytokines and chemokines that attract inflammatory cells into bronchial airways and plays an important role in asthma. Asthma patients who do not respond to marketed antiasthmatic drugs needed novel biological medications to regulate the asthmatic situation. The present review enumerates various types of asthma, etiological factors, and in vivo animal models for the induction of asthma. The underlying pathological, immunological mechanism of action, the role of inflammatory mediators, the effect of inflammation on the bronchial airways, newer treatment approaches, and novel biological targets of asthma have been discussed in this review.

16S Metagenomics Reveals Dysbiosis of Nasal Core Microbiota in Children With Chronic Nasal Inflammation: Role of Adenoid Hypertrophy and Allergic Rhinitis

Allergic rhinitis (AR) and adenoid hypertrophy (AH) are, in children, the main cause of partial or complete upper airway obstruction and reduction in airflow. However, limited data exist about the impact of the increased resistance to airflow, on the nasal microbial composition of children with AR end AH. Allergic rhinitis (AR) as well as adenoid hypertrophy (AH), represent extremely common pathologies in this population. Their known inflammatory obstruction is amplified when both pathologies coexist. In our study, the microbiota of anterior nares of 75 pediatric subjects with AR, AH or both conditions, was explored by 16S rRNA-based metagenomic approach. Our data show for the first time, that in children, the inflammatory state is associated to similar changes in the microbiota composition of AR and AH subjects respect to the healthy condition. Together with such alterations, we observed a reduced variability in the between-subject biodiversity on the other hand, these same alterations resulted amplified by the nasal obstruction that could constitute a secondary risk factor for dysbiosis. Significant differences in the relative abundance of specific microbial groups were found between diseased phenotypes and the controls. Most of these taxa belonged to a stable and quantitatively dominating component of the nasal microbiota and showed marked potentials in discriminating the controls from diseased subjects. A pauperization of the nasal microbial network was observed in diseased status in respect to the number of involved taxa and connectivity. Finally, while stable co-occurrence relationships were observed within both control- and diseases-associated microbial groups, only negative correlations were present between them, suggesting that microbial subgroups potentially act as maintainer of the eubiosis state in the nasal ecosystem. In the nasal ecosystem, inflammation-associated shifts seem to impact the more intimate component of the microbiota rather than representing the mere loss of microbial diversity. The discriminatory potential showed by differentially abundant taxa provide a starting point for future research with the potential to improve patient outcomes. Overall, our results underline the association of AH and AR with the impairment of the microbial interplay leading to unbalanced ecosystems.

Immunologic mechanisms in asthma

Asthma is a chronic airway disease, which affects more than 300 million people. The pathogenesis of asthma exhibits marked heterogeneity with many phenotypes defining visible characteristics and endotypes defining molecular mechanisms. With the evolution of novel biological therapies, patients, who do not-respond to conventional asthma therapy require novel biologic medications, such as anti-IgE, anti-IL-5 and anti-IL4/IL13 to control asthma symptoms. It is increasingly important for physicians to understand immunopathology of asthma and to characterize asthma phenotypes. Asthma is associated with immune system activation, airway hyperresponsiveness (AHR), epithelial cell activation, mucus overproduction and airway remodeling. Both innate and adaptive immunity play roles in immunologic mechanisms of asthma. Type 2 asthma with eosinophilia is a common phenotype in asthma. It occurs with and without visible allergy. The type 2 endotype comprises; T helper type 2 (Th2) cells, type 2 innate lymphoid cells (ILC2), IgE-secreting B cells and eosinophils. Eosinophilic nonallergic asthma is ILC2 predominated, which produces IL-5 to recruit eosinophil into the mucosal airway. The second major subgroup of asthma is non-type 2 asthma, which contains heterogeneous group of endoypes and phenotypes, such as exercise-induced asthma, obesity induced asthma, etc. Neutrophilic asthma is not induced by allergens but can be induced by infections, cigarette smoke and pollution. IL-17 which is produced by Th17 cells and type 3 ILCs, can stimulate neutrophilic airway inflammation. Macrophages, dendritic cells and NKT cells are all capable of producing cytokines that are known to contribute in allergic and nonallergic asthma. Bronchial epithelial cell activation and release of cytokines, such as IL-33, IL-25 and TSLP play a major role in asthma. Especially, allergens or environmental exposure to toxic agents, such as pollutants, diesel exhaust, detergents may affect the epithelial barrier leading to asthma development. In this review, we focus on the immunologic mechanism of heterogenous asthma phenotypes.

Expansion of commensal fungus Wallemia mellicola in the gastrointestinal mycobiota enhances the severity of allergic airway disease in mice

The gastrointestinal microbiota influences immune function throughout the body. The gut-lung axis refers to the concept that alterations of gut commensal microorganisms can have a distant effect on immune function in the lung. Overgrowth of intestinal Candida albicans has been previously observed to exacerbate allergic airways disease in mice, but whether subtler changes in intestinal fungal microbiota can affect allergic airways disease is less clear. In this study we have investigated the effects of the population expansion of commensal fungus Wallemia mellicola without overgrowth of the total fungal community. Wallemia spp. are commonly found as a minor component of the commensal gastrointestinal mycobiota in both humans and mice. Mice with an unaltered gut microbiota community resist population expansion when gavaged with W. mellicola; however, transient antibiotic depletion of gut microbiota creates a window of opportunity for expansion of W. mellicola following delivery of live spores to the gastrointestinal tract. This phenomenon is not universal as other commensal fungi (Aspergillus amstelodami, Epicoccum nigrum) do not expand when delivered to mice with antibiotic-depleted microbiota. Mice with Wallemia-expanded gut mycobiota experienced altered pulmonary immune responses to inhaled aeroallergens. Specifically, after induction of allergic airways disease with intratracheal house dust mite (HDM) antigen, mice demonstrated enhanced eosinophilic airway infiltration, airway hyperresponsiveness (AHR) to methacholine challenge, goblet cell hyperplasia, elevated bronchoalveolar lavage IL-5, and enhanced serum HDM IgG1. This phenomenon occurred with no detectable Wallemia in the lung. Targeted amplicon sequencing analysis of the gastrointestinal mycobiota revealed that expansion of W. mellicola in the gut was associated with additional alterations of bacterial and fungal commensal communities. We therefore colonized fungus-free Altered Schaedler Flora (ASF) mice with W. mellicola. ASF mice colonized with W. mellicola experienced enhanced severity of allergic airways disease compared to fungus-free control ASF mice without changes in bacterial community composition.

Severity of allergic rhinitis impacts sleep and anxiety: results from a large Spanish cohort

Background

Allergic rhinitis (AR) is a highly prevalent disease that generates high social and health care costs and also has a significant effect on quality of life and quality of sleep. It has also been related to some psychological disorders like anxiety or depression.

Objective

To evaluate anxiety, depression, and quality of sleep and life alteration in a group of patients with perennial AR compared to a group of seasonal AR patients.

Methods

Six-hundred seventy adults (> 18 years) with perennial and seasonal AR were recruited consecutively in 47 centers in Spain. Individuals were grouped in “Perennial” and “Seasonal” according to the seasonality of their symptoms. Anxiety, depression, sleep quality and health related quality of life were evaluated using the Hospital Anxiety and Depression Scale, Medical Outcomes Study Sleep Scale (MOS Sleep Scale) and the Health-related quality of life questionnaire ESPRINT-15, respectively. Both groups of patients were evaluated in and out of the pollen season.

Results

AR symptoms are related to worse quality of life and more anxiety and depression symptoms. Indeed, symptom severity also correlates with worse outcomes (quality of life, sleep and depression/anxiety) regardless allergen seasonality. Symptoms severity, compared with seasonality and persistence, is the most important factor related with more anxiety and depression and poor sleep. However, symptoms severity, persistence and seasonality are independently affecting the quality of life in patients with AR.

Conclusions

Although AR symptoms have a great impact on depression and anxiety symptoms, quality of life and quality of sleep in all AR patients, as expected, individuals with more severe AR seem to suffer more intensely their effects.

Electronic supplementary material

The online version of this article (10.1186/s13601-018-0212-0) contains supplementary material, which is available to authorized users.

Role of Type 2 Innate Lymphoid Cells in Allergic Diseases

PURPOSE OF REVIEW

The adaptive immune response orchestrated by type 2 T helper (Th2) lymphocytes, strictly cooperates with the innate response of group 2 innate lymphoid cells (ILC2), in the protection from helminths infection, as well as in the pathogenesis of allergic disease. The aim of this review is to explore the pathogenic role of ILC2 in different type 2-mediated disorders.

RECENT FINDINGS

Recent studies have shown that epithelial cell-derived cytokines and their responding cells, ILC2, play a pathogenic role in bronchial asthma, chronic rhinosinusitis, and atopic dermatitis. The growing evidences of the contribution of ILC2 in the induction and maintenance of allergic inflammation in such disease suggest the possibility to target them in therapy. Biological therapies blocking ILC2 activation or neutralizing their effector cytokines are currently under evaluation to be used in patients with type 2-dominated diseases.