Precision medicine in patients with allergic diseases: Airway diseases and atopic dermatitis-PRACTALL document of the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma & Immunology

Distinct immune phenotypes in infants developing asthma during childhood

Early exposure to environmental triggers may elicit trajectories to chronic inflammatory disease through deregulated immune responses. To address relations between early immune competence and development of childhood asthma, we performed functional immune profiling of 186 parameters in blood of 541 18-month-old infants and examined links between their response phenotype and development of transient or persistent disease at 6 years of age. An abnormal neutrophil-linked antiviral response was associated with increased risk of transient asthma. Children who exhibited persistent asthma at year 6 showed enhanced interleukin-5 (IL-5) and IL-13 production in stimulated T cells at 18 months of age, which was associated with early life bacterial colonization of the airways. These findings highlight the early appearance of distinct immune characteristics in infants developing different asthma endotypes during childhood.

The Current State of Biologic Therapies for Treatment of Refractory Asthma

Asthma is a heterogeneous disease, with the immune processes behind the chronic inflammation underlying this disorder differing between the various identified asthma endotypes. In addition to heterogeneity in underlying disease pathophysiology, asthmatics fall across a broad spectrum of disease severity and can vary greatly in their response to convention asthma therapies. A small percentage of patients with severe persistent asthma will remain uncontrolled despite treatment with high-dose inhaled corticosteroids and a long-acting beta-agonist. Less than two decades ago, there were few options for these treatment-refractory asthmatics beyond chronic systemic steroids, with their myriad of treatment-limiting side effects. However, in recent years, there have been a growing number of Food and Drug Administration (FDA)-approved biologic medications with targets that include immunoglobulin E (IgE), interleukin-5 (IL-5), the IL-5 receptor and the IL-4/IL-13 receptor-alpha subunit. The current FDA-approved biologics for severe persistent asthma are omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab. These monoclonal antibodies have been shown to improve asthma control, decrease asthma exacerbations and decrease glucocorticoid dependence in certain subsets of patients with asthma. The optimal biologic for treatment of severe asthma varies from patient to patient, depending on the underlying pathophysiology of the patient's disease. For each of these medications, there are certain biomarkers that can help predict whether a patient is likely to respond favorably to the medication. This review will discuss the currently approved biologics for severe persistent asthma, including their indications, efficacy and side effects.

Comorbidities and treatment patterns in adult patients with atopic dermatitis: results from a nationwide multicenter study

Adult atopic dermatitis (adult AD) is a systemic inflammatory disorder, whose relationship with immune-allergic and metabolic comorbidities is not well established yet. Moreover, treatment of mild-to-moderate and severe atopic dermatitis needs standardization among clinicians. The aim of this study was to evaluate the distribution of comorbidities, including metabolic abnormalities, rhinitis, conjunctivitis, asthma, alopecia and sleep disturbance, according to severity of adult AD, and describe treatments most commonly used by Italian dermatologists. Retrospective, observational, nationwide study of adult patients over a 2-year period was performed. Clinical and laboratory data were obtained through review of medical records of patients aged ≥ 18 years, followed in 23 Italian National reference centres for atopic dermatitis between September 2016 and September 2018. The main measurements evaluated were disease severity, atopic and metabolic comorbidities, treatment type and duration. Six-hundred and eighty-four adult patients with AD were included into the study. Atopic, but not metabolic conditions, except for hypertension, were significantly associated with having moderate-to-severe AD in young adult patients. Disease duration was significantly associated with disease severity. Oral corticosteroids and cyclosporine were the most widely used immunosuppressant. Our study seems confirm the close relationship between adult AD and other atopic conditions, further long-term cohort studies on patients affected by adult AD need to be performed to evaluate the complex relationship between adult AD disease severity and metabolic comorbidities.

Proteomic signatures of inflammatory skin diseases: a focus on atopic dermatitis

Introduction: Atopic dermatitis (AD) is a chronic inflammatory skin condition characterized by cutaneous and systemic inflammation and barrier abnormalities. Over the past few decades, proteomic studies have been increasingly applied to AD research to compliment transcriptomic evaluations. Proteomic analyses helped identify new biomarkers of AD, allowing investigation of both the cutaneous AD profile and the systemic inflammation associated with the disease.Areas covered: This review discusses key studies that utilized various proteomic technologies to analyze AD skin and/or blood, which facilitated discovery of biomarkers related to pathogenesis, disease severity, systemic inflammation, and therapeutic response. Moreover, this review summarizes proteomic studies that helped define various AD endotypes/phenotypes. A literature search was conducted by querying Scopus, Google Scholar, PubMed/Medline, and Clinicaltrials.gov up to January 2021.Expert opinion: Use of proteomics in AD has allowed for identification of novel AD-related protein biomarkers. This approach continues to evolve and is becoming increasingly common for the study of AD, in conjunction with other -omics platforms, as proteomics shifts to quicker and more sensitive methods for detection of potential protein biomarkers. Although many biomarkers have been identified thus far, future larger studies are necessary to further correlate these markers with clinical parameters.

Spotlight on microRNAs in allergy and asthma

In past 10 years, microRNAs (miRNAs) have gained scientific attention due to their importance in the pathophysiology of allergic diseases and their potential as biomarkers in liquid biopsies. They act as master post‐transcriptional regulators that control most cellular processes. As one miRNA can target several mRNAs, often within the same pathway, dysregulated expression of miRNAs may alter particular cellular responses and contribute, or lead, to the development of various diseases. In this review, we give an overview of the current research on miRNAs in allergic diseases, including atopic dermatitis, allergic rhinitis, and asthma. Specifically, we discuss how individual miRNAs function in the regulation of immune responses in epithelial cells and specialized immune cells in response to different environmental factors and respiratory viruses. In addition, we review insights obtained from experiments with murine models of allergic airway and skin inflammation and offer an overview of studies focusing on miRNA discovery using profiling techniques and bioinformatic modeling of the network effect of multiple miRNAs. In conclusion, we highlight the importance of research into miRNA function in allergy and asthma to improve our knowledge of the molecular mechanisms involved in the pathogenesis of this heterogeneous group of diseases.

Systemic and breath biomarkers for asthma: an update

PURPOSE OF REVIEW

Finding suitable biomarkers to phenotype asthma, identify individuals at risk of worsening and guide treatment is highly prioritized in asthma research. We aimed to provide an analysis of currently used and upcoming biomarkers, focusing on developments published in the past 2 years.

RECENT FINDINGS

Type 2 inflammation is the most studied asthma mechanism with the most biomarkers in the pipeline. Blood eosinophils and fractional exhaled nitric oxide (FeNO) are those most used clinically. Recent developments include their ability to identify individuals at higher risk of exacerbations, faster decline in lung function and more likely to benefit from anti-IL-5 and anti-IL-4/-13 treatment. Certain patterns of urinary eicosanoid excretion also relate to type 2 inflammation. Results of recent trials investigating the use of serum periostin or dipeptidyl peptidase-4 to guide anti-IL-13 therapy were somewhat disappointing. Less is known about non-type 2 inflammation but blood neutrophils and YKL-40 may be higher in patients with evidence of non-type 2 asthma. Volatile organic compounds show promise in their ability to distinguish both eosinophilic and neutrophilic asthma.

SUMMARY

The ultimate panel of biomarkers for identification of activated inflammatory pathways and treatment strategies in asthma patients still lies in the future, particularly for non-type 2 asthma, but potential candidates are available.

Rhinitis Phenotypes

Rhinitis is an umbrella term of a group of upper airway diseases with nasal symptoms and signs with different etiologies and various clinical features or traits. It can be classified into different "phenotypes," based on these observable traits. A proper differential diagnosis is necessary to adequately manage the disease. The objective of this review is to clarify the concept of rhinitis phenotypes while analyzing the clinical features and/or traits of each in order to determine a proper differential diagnosis and appropriate treatment.

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.

EAACI Biologicals Guidelines-dupilumab for children and adults with moderate-to-severe atopic dermatitis

Atopic dermatitis imposes a significant burden on patients, families and healthcare systems. Management is difficult, due to disease heterogeneity, co-morbidities, complexity in care pathways and differences between national or regional healthcare systems. Better understanding of the mechanisms has enabled a stratified approach to the management of atopic dermatitis, supporting the use of targeted treatments with biologicals. However, there are still many issues that require further clarification. These include the definition of response, strategies to enhance the responder rate, the duration of treatment and its regimen (in the clinic or home-based), its cost-effectiveness and long-term safety. The EAACI Guidelines on the use of dupilumab in atopic dermatitis follow the GRADE approach in formulating recommendations for each outcome and age group. In addition, future approaches and research priorities are discussed.

Epithelial barriers in allergy and asthma

The respiratory epithelium provides a physical, functional, and immunologic barrier to protect the host from the potential harming effects of inhaled environmental particles and to guarantee maintenance of a healthy state of the host. When compromised, activation of immune/inflammatory responses against exogenous allergens, microbial substances, and pollutants might occur, rendering individuals prone to develop chronic inflammation as seen in allergic rhinitis, chronic rhinosinusitis, and asthma. The airway epithelium in asthma and upper airway diseases is dysfunctional due to disturbed tight junction formation. By putting the epithelial barrier to the forefront of the pathophysiology of airway inflammation, different approaches to diagnose and target epithelial barrier defects are currently being developed. Using single-cell transcriptomics, novel epithelial cell types are being unraveled that might play a role in chronicity of respiratory diseases. We here review and discuss the current understandings of epithelial barrier defects in type 2-driven chronic inflammation of the upper and lower airways, the estimated contribution of these novel identified epithelial cells to disease, and the current clinical challenges in relation to diagnosis and treatment of allergic rhinitis, chronic rhinosinusitis, and asthma.

Treatable Mechanisms in Asthma

Asthma is a heterogeneous condition, but firm identification of heterogeneity-focused treatments is still lacking. Dividing patients into subgroups of asthma pheno-/endotypes based on combined clinical and cellular biological characteristics and linking them to targeted treatments could be a potentially useful approach to personalize therapy for better outcomes. Nonetheless, there are still many problems related to the identification and validation of asthma phenotypes and endotypes. Alternatively, a precision-medicine strategy for the management of patients with airways disease that is free from the traditional diagnostic labels and based on identifying "treatable traits" in each patient might be preferable. However, it would represent a quite unsophisticated approach because the definition of a treatable trait is too imprecise. In fact, there is still no understanding of the mechanisms underlying treatable traits that allow directing any targeted therapies against any particular treatable trait. Fortunately, in-depth identification of underlying molecular pathways to guide targeted treatment in individual patients is in progress thanks to the improvement in big data management obtained from '-omic' sciences that is greatly increasing knowledge concerning asthma.

Anti-Asthmatic Effects of Saffron Extract and Salbutamol in an Ovalbumin-Induced Airway Model of Allergic Asthma

Introduction: Asthma is a chronic inflammatory disorder of the airways often characterized by airway remodeling and influx of inflammatory cells into the airways. Saffron (C. sativus) has been reported to possess anti-inflammatory, anti-allergic and immunomodulatory properties. Salbutamol is known to relax airway smooth muscles. Objective: To investigate the combined anti-asthmatic effect of C. sativus extract (CSE) and salbutamol in an ovalbumin (OVA)-induced asthma in rats. Materials and methods: Airway hyperresponsiveness (AHR) was induced in male Sprague-Dawley rats by OVA challenge and treated with CSE (30 mg/kg and 60 mg/kg i.p.) and salbutamol (0.5 mg/kg p.o) for 28 days. After the induction period, various hematological, biochemical, molecular (ELISA) and histological analyses were performed. Results: OVA-induced alterations observed in hematological parameters (total and differential cell counts observed in Bronchoalveolar Lavage Fluid (BALF) were significantly attenuated (p < 0.01) by CSE (30 mg/kg and 60 mg/kg) and salbutamol (0.5 mg/kg). The treatment combination also significantly decreased (p < 0.01) the levels of total protein and albumin in serum, BALF and lung tissues. Treatment with CSE and salbutamol significantly attenuated (p < 0.01) increase in OVA induced Th2 cytokine levels (TNF-α, IL-1β, IL-4, IL-13). Histopathological analysis of lung tissue showed that combined effect of CSE and salbutamol treatment ameliorated OVA-induced inflammatory influx and ultrastructural aberrations. Conclusion: The results obtained from this study show that the combined effect of CSE and salbutamol exhibited anti-asthmatic properties via its anti-inflammatory effect and by alleviating Th2 mediated immune response. Thus, this treatment combination could be considered as a new therapeutic strategy for management of asthma.

Eczema Herpeticum: Clinical and Pathophysiological Aspects

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease in the world. AD is a complex pathology mainly characterized by an impaired skin barrier, immune response dysfunction, and unbalanced skin microbiota. Moreover, AD patients exhibit an increased risk of developing bacterial and viral infections. One of the most current, and potentially life-threatening, viral infection is caused by herpes simplex virus (HSV), which occurs in about 3% of AD patients under the name of eczema herpeticum (EH). Following a first part dedicated to the clinical features, virological diagnosis, and current treatments of EH, this review will focus on the description of the pathophysiology and, more particularly, the presently known predisposing factors to herpetic complications in AD patients. These factors include those related to impairment of the skin barrier such as deficit in filaggrin and anomalies in tight and adherens junctions. In addition, low production of the antimicrobial peptides cathelicidin LL-37 and human β-defensins; overexpression of cytokines such as interleukin (IL)-4, IL-13, IL-25, IL-33, and thymic stromal lymphopoietin (TSLP); or downregulation of type I to III interferons as well as defect in functions of immune cells such as dendritic, natural killer, and regulatory T cells have been involved. Otherwise, genetic polymorphisms and AD topical calcineurin inhibitor treatments have been associated with an increased risk of EH. Finally, dysbiosis of skin microbiota characterized in AD patients by Staphylococcus aureus colonization and toxin secretion, such as α-toxin, has been described as promoting HSV replication and could therefore contribute to EH.

Efficacy and safety of dupilumab for moderate-to-severe atopic dermatitis: A systematic review for the EAACI biologicals guidelines

This systematic review evaluates the efficacy, safety and economic impact of dupilumab compared to standard of care for uncontrolled moderate-to-severe atopic dermatitis (AD). Pubmed, EMBASE and Cochrane Library were searched for RCTs and health economic evaluations. Critical and important AD-related outcomes were considered. The risk of bias and the certainty of the evidence were assessed using GRADE. Seven RCTs including 1845 subjects >12 years treated with dupilumab 16 to 52 weeks were evaluated. For adults, there is high certainty that dupilumab decreases SCORAD (MD -30,72; 95% CI -34,65% to -26,79%) and EASI-75 (RR 3.09; 95% CI 2.45 to 3.89), pruritus (RR 2.96; 95% CI 2.37 to 3.70), rescue medication (RR 3.46; 95% CI 2.79 to 4.30), sleep disturbance (MD -7.29; 95% CI -8.23 to -6.35) and anxiety/depression (MD -3.08; 95% CI -4.41 to -1.75) and improves quality of life (MD -4.80; 95% CI -5.55 to -4.06). The efficacy for adolescents is similar. Dupilumab-related adverse events (AEs) slightly increase (low certainty). The evidence for dupilumab-related serious AE is uncertain. The incremental cost-effectiveness ratio ranged from 28 500 £ (low certainty) to 124 541 US$ (moderate certainty). More data on long-term safety are needed both for children and for adults, together with more efficacy data in the paediatric population. Registration: PROSPERO (CRD42020153645).

A Precision Medicine Approach to Treating Alzheimer's Disease Using Rosiglitazone Therapy: A Biomarker Analysis of the REFLECT Trials

BACKGROUND

The REFLECT trials were conducted to examine the treatment of mild-to-moderate Alzheimer's disease utilizing a peroxisome proliferator-activated receptor gamma agonist.

OBJECTIVE

To generate a predictive biomarker indicative of positive treatment response using samples from the previously conducted REFLECT trials.

METHODS

Data were analyzed on 360 participants spanning multiple negative REFLECT trials, which included treatment with rosiglitazone and rosiglitazone XR. Support vector machine analyses were conducted to generate a predictive biomarker profile.

RESULTS

A pre-defined 6-protein predictive biomarker (IL6, IL10, CRP, TNFα, FABP-3, and PPY) correctly classified treatment response with 100%accuracy across study arms for REFLECT Phase II trial (AVA100193) and multiple Phase III trials (AVA105640, AV102672, and AVA102670). When the data was combined across all rosiglitazone trial arms, a global RSG-predictive biomarker with the same 6-protein predictive biomarker was able to accurately classify 98%of treatment responders.

CONCLUSION

A predictive biomarker comprising of metabolic and inflammatory markers was highly accurate in identifying those patients most likely to experience positive treatment response across the REFLECT trials. This study provides additional proof-of-concept that a predictive biomarker can be utilized to help with screening and predicting treatment response, which holds tremendous benefit for clinical trials.

Allergic rhinitis

Allergic rhinitis (AR) is caused by immunoglobulin E (IgE)-mediated reactions to inhaled allergens and is one of the most common chronic conditions globally. AR often co-occurs with asthma and conjunctivitis and is a global health problem causing major burden and disability worldwide. Risk factors include inhalant and occupational allergens, as well as genetic factors. AR impairs quality of life, affects social life, school and work, and is associated with substantial economic costs. The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative classified AR into intermittent or persistent and mild or moderate/severe. The diagnosis is based on the clinical history and, if needed in patients with uncontrolled rhinitis despite medications or with long-lasting symptoms, on skin tests or the presence of serum-specific IgE antibodies to allergens. The most frequently used pharmacological treatments include oral, intranasal or ocular H₁-antihistamines, intranasal corticosteroids or a fixed combination of intranasal H₁-antihistamines and corticosteroids. Allergen immunotherapy prescribed by a specialist using high-quality extracts in stratified patients is effective in patients with persistent symptoms. Real-world data obtained by mobile technology offer new insights into AR phenotypes and management. The outlook for AR includes a better understanding of novel multimorbid phenotypes, health technology assessment and patient-centred shared decision-making.

Real-life assessment of chronic rhinosinusitis patients using mobile technology: The mySinusitisCoach project by EUFOREA

BACKGROUND

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease associated with a substantial personal and socioeconomic burden. Monitoring of patient-reported outcomes by mobile technology offers the possibility to better understand real-life burden of CRS.

METHODS

This study reports on the cross-sectional evaluation of data of 626 users of mySinusitisCoach (mSC), a mobile application for CRS patients. Patient characteristics of mSC users were analysed as well as the level of disease control based on VAS global rhinosinusitis symptom score and adapted EPOS criteria.

RESULTS

The mSC cohort represents a heterogeneous group of CRS patients with a diverse pattern of major symptoms. Approximately half of patients reported nasal polyps. 47.3% of all CRS patients were uncontrolled based on evaluation of VAS global rhinosinusitis symptom score compared to 40.9% based on adapted EPOS criteria. The impact of CRS on sleep quality and daily life activities was significantly higher in uncontrolled versus well-controlled patients. Half of patients had a history of FESS (functional endoscopic sinus surgery) and reported lower symptom severity compared to patients without a history of FESS, except for patients with a history of more than 3 procedures. Patients with a history of FESS reported higher VAS levels for impaired smell.

CONCLUSION

Real-life data confirm the high disease burden in uncontrolled CRS patients, clearly impacting quality of life. Sinus surgery improves patient-reported outcomes, but not in patients with a history of more than 3 procedures. Mobile technology opens a new era of real-life monitoring, supporting the evolution of care towards precision medicine.

Physiopathologie de la dermatite atopique et des autres maladies atopiques : une approche globale est-elle possible ?

Atopy is defined by the propensity to develop an exaggerated type-2 inflammatory response to environmental molecules. Clinically, atopy is diagnosed when atopic disease occurs: atopic dermatitis, food allergy, atopic asthma and allergic rhinitis and conjunctivitis. Whereas the classical "atopic march" is increasingly challenged through epidemiological studies, type-2 cellular inflammation is a characteristic shared by the atopic diseases. This inflammation can be innate (non-specific: eosinophils, mast cells, dendritic cells, innate lymphoid cells [ILC]), or adaptive (antigen-specific, involving T cells). Interleukins (IL-)4, 5 and 13 are major actors of type-2 inflammation and are mainly produced by ILC and T cells. The efficacy of treatments targeting these type-2 cytokines highlight the importance of type-2 inflammation in atopic diseases. However, several patients do not respond to type-2 targeting treatments, highlighting the presence of other actors in pathophysiology of atopic diseases: alteration of epithelial barrier, IgE-mediated allergic responses, type-17 inflammation. Thus, the term "endotype" can illustrate this diversity in pathophysiology. Finally, a global approach of atopic diseases, as type-2 inflammatory diseases, is fundamental, but not sufficient. An approach by endotype is advisable, in a personalized medicine perspective. © 2020 Elsevier Masson SAS. All rights reserved.

Blockage of sphingosine-1-phosphate receptor 2 attenuates 2,4-dinitrochlorobenzene-induced atopic dermatitis in mice

Sphingosine-1-phosphate (S1P) and its receptors have been implicated in functions of Langerhans cells and atopic dermatitis. In this study, we investigated the roles of S1P receptor type 2 (S1P₂) in a mouse model of atopic dermatitis, which was induced by topical application of 2,4-dinitrochlorobenzene (DNCB) on ventral skin on D0, followed by repeated DNCB challenge on both ears from D7 to D49. Wild-type mice with atopic dermatitis displayed severe inflammation and mast cell accumulation in ear tissues and elevated IgE levels in serum. Furthermore, the mice showed significantly increased sizes of draining lymph nodes, high levels of inflammatory cytokines (IL-4, IL-13, IL-17, and IFN-γ) in the ears and lymph nodes and high levels of chemokines CCL17 and CCL22 in ears. Administration of JTE-013, a selective antagonist of S1P₂ (3 mg/kg, i.p, from D19 to D49) before DNCB challenge significantly suppressed DNCB-induced atopic responses in ears and lymph nodes. JTE-013 administration also significantly decreased the lymph nodes sizes, the levels of inflammatory cytokines (IL-4, IL-13, IL-17, and IFN-γ) in the ears and lymph nodes, and the levels of chemokines CCL17 and CCL22 in ears. Furthermore, the inflammatory responses of atopic dermatitis were greatly ameliorated in S1pr2 gene-deficient mice. As CCL17 and CCL22 are CCR4 ligands, acting as Th2-attracting chemokines, we investigated CCL17 and CCL22 expression in bone marrow-derived dendritic cells (BMDCs) from wild-type and S1pr2 gene-deficient mice. Addition of IL-4 (10 ng/mL) markedly increased the levels of CCL17 and CCL22, but IL-4-induced CCL17 and CCL22 expression was significantly blunted in BMDCs from S1pr2 gene-deficient mice. Furthermore, pretreatment with JTE-013 (1-30 μM) dose-dependently suppressed this induction in BMDCs from wild-type mice. Our results demonstrate that blockage of S1P₂ ameliorates not only DNCB-induced atopic dermatitis symptoms but also Th2 cell-attracting capacity of dendritic cells, suggesting S1P₂ as a potential therapeutic target for atopic dermatitis.

Topical Application of S1P2 Antagonist JTE-013 Attenuates 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis in Mice

Sphingosine-1-phosphate (S1P) and its receptors have been implicated in atopic dermatitis. S1P₂ was found to function as a pro-allergic receptor, while its antagonist JTE-013 was found to suppress allergic asthma in mice. Topical application of JTE-013 has not been investigated in an in vivo model of atopic dermatitis. Therefore, the therapeutic potential of JTE-013 topical application was evaluated by the use of a 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis mouse model. DNCB-induced inflammation and mast cell accumulation in skin tissues were significantly suppressed by topical JTE-013 treatment in BALB/c mice. DNCB-induced increase of lymph nodes sizes and elevated inflammatory cytokines (IL-4, IL-13, IL-17, and IFN-γ) in lymph nodes were also significantly reduced by the JTE-013 treatment. Elevated serum levels of IgE were significantly suppressed by the topical treatment of JTE-013. In summary, the topical treatment of JTE-013 S1P₂ antagonist suppressed DNCB-induced atopic dermatitis symptoms and immune responses. These results suggested JTE-013 as a potential therapeutic agent for atopic dermatitis.

Analysis of the immunoglobin E molecular sensitization profile in children with allergic asthma and predictive factors for the efficacy of allergy immunotherapy

Background

As the incidence of allergic asthma in children increases, the immunoglobin E (IgE) molecular sensitization profile of allergic asthma remains underreported while the level of total IgE (tIgE) and sIgE/tIgE have not been studied as predictors of efficacy of allergen immunotherapy (AIT) for allergic asthma, specifically in children.

Methods

Starting from August 2018 to March 2019 in the Respiratory Department of the Children’s Hospital of Chongqing Medical University, asthmatic children, with positive skin prick tests to Der p or Der f, were enrolled in this study. Total IgE, allergen serum-specific IgE (sIgE) of Der p, Der f, Blomia tropicalis (Blo t), cat dander, dog dander, egg white, milk, cockroach, shrimp, and crab, along with Der p allergen components, Der p1 and Der p2, were measured by ImmunoCAP™ assay.

Results

A total of 142 children with allergic asthma were enrolled, all of whom showed positive IgE for Der p, Der p1, Der p2, and Der f; meanwhile, the positive rates of Blo t, cat dander, dog dander, egg white, milk, cockroach, shrimp, and crab were 91.84%, 10.96%, 7.32%, 9.15%, 11.58%, 17.03%, 18.90%, and 18.28% respectively. A significantly high correlation was found between total IgE and the sIgE of Der f, Der p, Der p 1, and Der p 2. Asthmatic children with a family history of allergy displayed higher total IgE and unknown IgE levels than those patients without a family history of allergy. The ratios of Der f sIgE/tIgE and Der p sIgE/tIgE were higher in the negative family history of allergy group than in the positive family history of allergy group. Furthermore, total IgE and unknown IgE were higher in the polysensitized group than in the in monosensitized group. The ratios of Der f sIgE/tIgE and Der p sIgE/tIgE were higher in the monosensitized group than in the polysensitized group.

Conclusions

From this study, we noticed that dust mites are the main cause of asthma in children investigated. Our findings indicate patients with no family history of allergy and monosensitized patients have a higher ratio of sIgE/tIgE, and those patients may benefit more from AIT.

Free fatty acid receptor 4 (FFA4) activation ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis by increasing regulatory T cells in mice

High dose intake of docosahexaenoic acid showed beneficial effects on atopic dermatitis in patients and was found to increase regulatory T cells in mice, but its molecular target has not been identified. Free fatty acid receptor 4 (FFA4, also known as GPR120) is a receptor sensing polyunsaturated long-chain fatty acids including docosahexaenoic acid. In the present study, we examined whether FFA4 acted as a therapeutic target of docosahexaenoic acid for treating atopic dermatitis. Experimental atopic dermatitis was induced in mice by 2,4-dinitrochlorobenzene (DNCB) sensitization on day 0, followed by repeated DNCB challenges from D7 to D48. The mice were treated with a selective agonist compound A (30 mg· kg⁻¹· d⁻¹, ip) from D19 to D48, and sacrificed on D49. We found that DNCB-induced atopic dermatitis-like skin lesions, i.e. hypertrophy and mast cell infiltration in skin tissues, as well as markedly elevated serum IgE levels. Administration of compound A significantly suppressed the atopic responses in ears and lymph nodes, such as hypertrophy and mast cell infiltration in the ears, enlarged sizes of lymph nodes, and elevated serum IgE and levels of cytokines IL-4, IL-13, IL-17, and IFN-γ in ear tissue. The therapeutic effects of compound A were abolished by FFA4 knockout. Similarly, increased CD4⁺Foxp3⁺ regulatory T-cell population in lymph nodes was observed in wide-type mice treated with compound A, but not seen in FFA4-deficient mice. In conclusion, we demonstrate that activation of FFA4 ameliorates atopic dermatitis by increasing CD4⁺Foxp3⁺ regulatory T cells, suggesting FFA4 as a therapeutic target for atopic dermatitis.

The genetics of asthma and the promise of genomics-guided drug target discovery

Asthma is an inflammatory airway disease that is estimated to affect 339 million people globally. The symptoms of about 5-10% of patients with asthma are not adequately controlled with current therapy, and little success has been achieved in developing drugs that target the underlying mechanisms of asthma rather than suppressing symptoms. Over the past 3 years, well powered genetic studies of asthma have increased the number of independent asthma-associated genetic loci to 128. In this Series paper, we describe the immense progress in asthma genetics over the past 13 years and link asthma genetic variants to possible drug targets. Further studies are needed to establish the functional significance of gene variants associated with asthma in subgroups of patients and to describe the biological networks within which they function. The genomics-guided discovery of plausible drug targets for asthma could pave the way for the repurposing of existing drugs for asthma and the development of new treatments.

Expression, Distribution and Role of Aquaporins in Various Rhinologic Conditions

Aquaporins (AQPs) are water-specific membrane channel proteins that regulate cellular and organismal water homeostasis. The nose, an organ with important respiratory and olfactory functions, is the first organ exposed to external stimuli. Nose-related topics such as allergic rhinitis (AR) and chronic rhinosinusitis (CRS) have been the subject of extensive research. These studies have reported that mechanisms that drive the development of multiple inflammatory diseases that occur in the nose and contribute to the process of olfactory recognition of compounds entering the nasal cavity involve the action of water channels such as AQPs. In this review, we provide a comprehensive overview of the relationship between AQPs and rhinologic conditions, focusing on the current state of knowledge and mechanisms that link AQPs and rhinologic conditions. Key conclusions include the following: (1) Various AQPs are expressed in both nasal mucosa and olfactory mucosa; (2) the expression of AQPs in these tissues is different in inflammatory diseases such as AR or CRS, as compared with that in normal tissues; (3) the expression of AQPs in CRS differs depending on the presence or absence of nasal polyps; and (4) the expression of AQPs in tissues associated with olfaction is different from that in the respiratory epithelium.

Gut-organ axis: a microbial outreach and networking

Human gut microbiota (GM) includes a complex and dynamic population of microorganisms that are crucial for well-being and survival of the organism. It has been reported as diverse and relatively stable with shared core microbiota, including Bacteroidetes and Firmicutes as the major dominants. They are the key regulators of body homeostasis, involving both intestinal and extra-intestinal effects by influencing many physiological functions such as metabolism, maintenance of barrier homeostasis, inflammation and hematopoiesis. Any alteration in GM community structures not only trigger gut disorders but also influence other organs and cause associated diseases. In recent past, the GM has been defined as a 'vital organ' with its involvement with other organs; thus, establishing a link or a bi- or multidirectional communication axis between the organs via neural, endocrine, immune, humoral and metabolic pathways. Alterations in GM have been linked to several diseases known to humans; although the exact interaction mechanism between the gut and the organs is yet to be defined. In this review, the bidirectional relationship between the gut and the vital human organs was envisaged and discussed under several headings. Furthermore, several disease symptoms were also revisited to redefine the communication network between the gut microbes and the associated organs.

Epigenetics and the Environment in Airway Disease: Asthma and Allergic Rhinitis

Asthma and rhinitis are complex, heterogeneous diseases characterized by chronic inflammation of the upper and lower airways. While genome-wide association studies (GWAS) have identified a number of susceptible loci and candidate genes associated with the pathogenesis of asthma and allergic rhinitis (AR), the risk-associated alleles account for only a very small percent of the genetic risk. In allergic airway and other complex diseases, it is thought that epigenetic modifications, including DNA methylation, histone modifications, and non-coding microRNAs, caused by complex interactions between the underlying genome and the environment may account for some of this "missing heritability" and may explain the high degree of plasticity in immune responses. In this chapter, we will focus on the current knowledge of classical epigenetic modifications, DNA methylation and histone modifications, and their potential role in asthma and AR. In particular, we will review epigenetic variations associated with maternal airway disease, demographics, environment, and non-specific associations. The role of specific genetic haplotypes in environmentally induced epigenetic changes are also discussed. A major limitation of many of the current studies of asthma epigenetics is that they evaluate epigenetic modifications in both allergic and non-allergic asthma, making it difficult to distinguish those epigenetic modifications that mediate allergic asthma from those that mediate non-allergic asthma. Additionally, most DNA methylation studies in asthma use peripheral or cord blood due to poor accessibility of airway cells or tissue. Unlike DNA sequences, epigenetic alterations are quite cell- and tissue-specific, and epigenetic changes found in airway tissue or cells may be discordant from that of circulating blood. These two confounding factors should be considered when reviewing epigenetic studies in allergic airway disease.

Type 2 immunity in the skin and lungs

There has been extensive progress in understanding the cellular and molecular mechanisms of inflammation and immune regulation in allergic diseases of the skin and lungs during the last few years. Asthma and atopic dermatitis (AD) are typical diseases of type 2 immune responses. interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin are essential cytokines of epithelial cells that are activated by allergens, pollutants, viruses, bacteria, and toxins that derive type 2 responses. Th2 cells and innate lymphoid cells (ILC) produce and secrete type 2 cytokines such as IL-4, IL-5, IL-9, and IL-13. IL-4 and IL-13 activate B cells to class-switch to IgE and also play a role in T-cell and eosinophil migration to allergic inflammatory tissues. IL-13 contributes to maturation, activation, nitric oxide production and differentiation of epithelia, production of mucus as well as smooth muscle contraction, and extracellular matrix generation. IL-4 and IL-13 open tight junction barrier and cause barrier leakiness in the skin and lungs. IL-5 acts on activation, recruitment, and survival of eosinophils. IL-9 contributes to general allergic phenotype by enhancing all of the aspects, such as IgE and eosinophilia. Type 2 ILC contribute to inflammation in AD and asthma by enhancing the activity of Th2 cells, eosinophils, and their cytokines. Currently, five biologics are licensed to suppress type 2 inflammation via IgE, IL-5 and its receptor, and IL-4 receptor alpha. Some patients with severe atopic disease have little evidence of type 2 hyperactivity and do not respond to biologics which target this pathway. Studies in responder and nonresponder patients demonstrate the complexity of these diseases. In addition, primary immune deficiency diseases related to T-cell maturation, regulatory T-cell development, and T-cell signaling, such as Omenn syndrome, severe combined immune deficiencies, immunodysregulation, polyendocrinopathy, enteropathy, X-linked syndrome, and DOCK8, STAT3, and CARD11 deficiencies, help in our understanding of the importance and redundancy of various type 2 immune components. The present review aims to highlight recent advances in type 2 immunity and discuss the cellular sources, targets, and roles of type 2 mechanisms in asthma and AD.

Treatments for Childhood Atopic Dermatitis: an Update on Emerging Therapies

Atopic dermatitis (AD) is generally considered a T helper type 2-dominated disease. Pediatric AD is usually less severe than adult AD, but it may present as moderate to severe lesions that are inadequately managed by current modalities including emollients/moisturizers, topical corticosteroids (TCSs), topical calcineurin inhibitors (TCIs), and even systemic immunosuppressants (such as cyclosporine, azathioprine, methotrexate, and mycophenolate mofetil). In addition, systemic immunosuppressants are often not recommended for childhood AD by the current guidelines due to their toxicities. Therefore, there is still an unmet need for a safe and effective long-term therapy for pediatric AD patients whose disease is inadequately controlled or who are intolerant to current treatments. The emerging therapeutics for AD focuses on intervening in the inflammatory pathway by targeting specific cytokines/chemokines or their receptors. Monoclonal antibodies against immunoglobulin E (IgE), interleukin (IL)-4 receptor subunit α, IL-5, IL-13, IL-31 receptor subunit α, IL-33, and thymic stromal lymphopoietin (TSLP) have been evaluated clinically for AD. Encouraging results have been reported for many of the biologics, of which the most exciting is dupilumab. Other emerging systemic therapies include small molecules such as baricitinib, abrocitinib, upadacitinib, and tradipitant. Several novel topical agents are under clinical investigation for the treatment of AD, including topical phosphodiesterase 4 (PDE4) inhibitors, Janus kinase (JAK) inhibitors, aryl hydrocarbon receptor (AhR) modulating agents, and transient receptor potential vanilloid subfamily member 1 (TRPV1) antagonists. Accompanied by thorough characterization of different phenotype and endotype subsets, the application of precision medicine could provide new prospects for the optimal treatment of AD.

Relationship between chemokines and T lymphocytes in the context of respiratory allergies (Review)

Allergic diseases have been classified in the last decades using various theories. The main classes of the newest classification in allergic respiratory diseases focus on the characterization of the endotype (which takes into account biomarkers related to determinant pathophysiological mechanisms) and of the phenotype (based on the description of the disease). Th2, Th1 and Th17 lymphocytes and the type of inflammatory response mediated by them represent the basis for Th2 and non-Th2 endotype classification. In addition, new lymphocytes were also used to characterize allergic diseases: Th9 lymphocytes, Th22 lymphocytes, T follicular helper cells (T_FH) lymphocytes and invariant natural killer T (iNKT) lymphocytes. In the last decade, a growing body of evidence focused on chemokines, chemoattractant cytokines, which seems to have an important contribution to the pathogenesis of this pathology. This review presents the interactions between chemokines and Th lymphocytes in the context of Th2/non-Th2 endotype classification of respiratory allergies.

Impact of Endoplasmic Reticulum Stress in Otorhinolaryngologic Diseases

The endoplasmic reticulum (ER) is an important organelle for normal cellular function and homeostasis in most living things. ER stress, which impairs ER function, occurs when the ER is overwhelmed by newly introduced immature proteins or when calcium in the ER is depleted. A number of diseases are associated with ER stress, including otorhinolaryngological diseases. The relationship between ER stress and otorhinolaryngologic conditions has been the subject of investigation over the last decade. Among otologic diseases associated with ER stress are otitis media and hearing loss. In rhinologic diseases, chronic rhinosinusitis, allergic rhinitis, and obstructive sleep apnea are also significantly associated with ER stress. In this review, we provide a comprehensive overview of the relationship between ER stress and otorhinolaryngological diseases, focusing on the current state of knowledge and mechanisms that link ER stress and otorhinolaryngologic diseases.

Different Development Forms of Local Allergic Rhinitis towards Birch

Background

Efficacy of allergen immunotherapy (AIT) in local allergic rhinitis (LAR) is a new subject of research. The presence of asthmatic symptoms in patients with LAR in the context of AIT is unexplored.

Objective

The efficacy and safety of AIT in patients with LAR towards birch pollen were investigated. The possibility of concomitant local allergic asthma in studied patients and the impact of AIT on it were examined.

Methods

36 patients with LAR towards birch were included in three years of AIT in a double-blind, placebo-control study. Primary outcome measurement was the mean changes in the combined symptom and medication scores (CSMSs) after AIT, and the second is the changes in the quality of life (QoL). Skin prick tests, serum, nasal allergen-specific IgE to birch, nasal and bronchial provocation challenge tests with birch allergen, methacholine tests, and spirometry were carried out at baseline and after AIT.

Results

Mean CSMSs of three years of AIT were significantly decreased in the active group from 5.88 (range: 4.11-9.01) to 1.98 (range: 1.22-4.51; p < 0.05). After three years of AIT, there was a significant increase of toleration for birch allergen from the mean concentration of 6250 ± 1200 SQ-U/ml up to 45000 ± 2500 SQ-U/ml (p = 0.02) during repeated nasal challenges. 16 patients with LAR had the positive results of methacholine tests, and 11 of them had a positive bronchial challenge to birch allergen. After AIT, the significant decrease of bronchial responsiveness to birch allergen in 5 from 7 patients was confirmed (p = 0.03). QoL assessed by the use of the RQLQ score was improved after AIT from 1.84 (95% CI: 1.53-1.97) to 1.45 (95% CI: 1.32-1.62) score in the active group after three years of AIT therapy (p = 0.03).

Conclusion

AIT to birch can be useful and safe in a patient with local allergic rhinitis and also with concomitant asthmatic symptoms. Further studies are needed.

Leveraging -omics for asthma endotyping

Asthma is a highly heterogeneous disease, often manifesting with wheeze, dyspnea, chest tightness, and cough as prominent symptoms. The eliciting factors, natural history, underlying molecular biology, and clinical management of asthma vary highly among affected subjects. Because of this variation, many efforts have gone into subtyping asthma. Endotypes are subtypes of disease based on distinct pathophysiologic mechanisms. Endotypes can be clinically useful because they organize our mechanistic understanding of heterogeneous diseases and can direct treatment toward modalities that are likely to be the most effective. Asthma endotyping can be shaped by clinical features, laboratory parameters, and/or -omics approaches. We discuss the application of -omics approaches, including transcriptomics, epigenomics, microbiomics, metabolomics, and proteomics, to asthma endotyping. -Omics approaches have provided supporting evidence for many existing endotyping paradigms and also suggested novel ways to conceptualize asthma endotypes. Although endotypes based on single -omics approaches are relatively common, their integrated multi-omics application to asthma endotyping has been more limited thus far. We discuss paths forward to integrate multi-omics with clinical features and laboratory parameters to achieve the goal of precise asthma endotypes.

Could FeNO Predict Asthma in Patients with House Dust Mites Allergic Rhinitis?

Background and Objectives: The evolution of allergic rhinitis to asthma is a part of "atopic march". The aim of this study was to analyze possible predictive markers for asthma occurrence in patients with allergic rhinitis to house dust mites (HDM). Materials and Methods: Fifty-eight patients with persistent allergic rhinitis (PAR) were included. The clinical, biological evaluation and fractionated exhaled nitric oxide (FeNO) measurement were performed at enrolment. The patients were clinically evaluated after one year to determine asthma occurrence. Results: The severity of rhinitis symptoms, levels of total immunoglobulin E (IgE), ICAM-1, VCAM-1, E-selectin and IL-6, but not IL-8 and TNF-α were higher in patients with allergic rhinitis who developed asthma compared to non-asthmatics, but the differences were not significant to considered them as predictive factors for asthma occurrence. The risk of asthma was independently influenced by patients aged over 30 years ((OR-3.74; CI95% 0.86-16.31; p = 0.07), a duration of allergic rhinitis over 12 months ((OR-4.20; CI95% 0.88-20; p = 0.07) and a basal FeNO over 28 parts per billion (pbb) ((OR-18.68; CI95% 3.79-92.05; p < 0.001). Conclusion: Clinical and biological parameters may predict asthma occurrence in patients with persistent allergic rhinitis to HDM. Adult patients with a longer duration of rhinitis symptoms and a high level of FeNO have a greater risk to develop asthma.

Group 2 Innate Lymphoid Cells and the House Dust Mite-Induced Asthma Mouse Model

Asthma is an important issue not only in health but also in economics worldwide. Therefore, asthma animal models have been frequently used to understand the pathogenesis of asthma. Recently, in addition to acquired immunity, innate immunity has also been thought to be involved in asthma. Among innate immune cells, group 2 innate lymphoid cells (ILC2s) have been considered to be crucial for eosinophilic airway inflammation by releasing T helper 2 cytokines. Moreover, house dust mites (HDMs) belonging to group 1 act on airway epithelial cells not only as allergens but also as cysteine proteases. The production of interleukin-25 (IL-25), IL-33, and thymic stromal lymphopoietin (TSLP) from airway epithelial cells was induced by the protease activity of HDMs. These cytokines activate ILC2s, and activated ILC2s produce IL-5, IL-9, IL-13, and amphiregulin. Hence, the HDM-induced asthma mouse model greatly contributes to understanding asthma pathogenesis. In this review, we highlight the relationship between ILC2s and the HDM in the asthma mouse model to help researchers and clinicians not only choose a proper asthma mouse model but also to understand the molecular mechanisms underlying HDM-induced asthma.

Resolving Clinical Phenotypes into Endotypes in Allergy: Molecular and Omics Approaches

Allergic diseases are highly complex with respect to pathogenesis, inflammation, and response to treatment. Current efforts for allergic disease diagnosis have focused on clinical evidence as a binary outcome. Although outcome status based on clinical phenotypes (observable characteristics) is convenient and inexpensive to measure in large studies, it does not adequately provide insight into the complex molecular determinants of allergic disease. Individuals with similar clinical diagnoses do not necessarily have similar disease etiologies, natural histories, or responses to treatment. This heterogeneity contributes to the ineffective response to treatment leading to an annual estimated cost of $350 billion in the USA alone. There has been a recent focus to deconvolute the clinical heterogeneity of allergic diseases into specific endotypes using molecular and omics approaches. Endotypes are a means to classify patients based on the underlying pathophysiological mechanisms involving distinct functions or treatment response. The advent of high-throughput molecular omics, immunophenotyping, and bioinformatics methods including machine learning algorithms is facilitating the development of endotype-based diagnosis. As we move to the next decade, we should truly start treating clinical endotypes not clinical phenotype. This review highlights current efforts taking place to improve allergic disease endotyping via molecular omics profiling, immunophenotyping, and machine learning approaches in the context of precision diagnostics in allergic diseases. Graphical Abstract.

FFA2 Activation Ameliorates 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis in Mice

Gut microbiota produce dietary metabolites such as short-chain fatty acids, which exhibit anti-inflammatory effects. Free fatty acid receptor 2 (FFA2, formerly known as GPR43) is a specific receptor for short-chain fatty acids, such as acetate that regulates inflammatory responses. However, the therapeutic potential of FFA2 agonists for treatment of atopic dermatitis has not been investigated. We investigated the efficacy of the FFA2 agonist, 4-chloro-α-(1-methylethyl)-N-2-thiazoylylbenzeneacetanilide (4-CMTB), for treatment of atopic dermatitis induced by 2,4-dinitrochlorobenzene (DNCB). Long-term application of DNCB to the ears of mice resulted in significantly increased IgE in the serum, and induced atopic dermatitis-like skin lesions, characterized by mast cell accumulation and skin tissue hypertrophy. Treatment with 4-CMTB (10 mg/kg, i.p.) significantly suppressed DNCB-induced changes in IgE levels, ear skin hypertrophy, and mast cell accumulation. Treatment with 4-CMTB reduced DNCB-induced increases in Th2 cytokine (IL-4 and IL-13) levels in the ears, but did not alter Th1 or Th17 cytokine (IFN-γ and IL-17) levels. Furthermore, 4-CMTB blocked DNCB-induced lymph node enlargement. In conclusion, activation of FFA2 ameliorated DNCB-induced atopic dermatitis, which suggested that FFA2 is a therapeutic target for atopic dermatitis.

Precision Medicine in Childhood Asthma: Omic Studies of Treatment Response

Asthma is a heterogeneous and multifactorial respiratory disease with an important impact on childhood. Difficult-to-treat asthma is not uncommon among children, and it causes a high burden to the patient, caregivers, and society. This review aims to summarize the recent findings on pediatric asthma treatment response revealed by different omic approaches conducted in 2018–2019. A total of 13 studies were performed during this period to assess the role of genomics, epigenomics, transcriptomics, metabolomics, and the microbiome in the response to short-acting beta agonists, inhaled corticosteroids, and leukotriene receptor antagonists. These studies have identified novel associations of genetic markers, epigenetic modifications, metabolites, bacteria, and molecular mechanisms involved in asthma treatment response. This knowledge will allow us establishing molecular biomarkers that could be integrated with clinical information to improve the management of children with asthma.

Recent developments and advances in atopic dermatitis and food allergy

This review highlights recent advances in atopic dermatitis (AD) and food allergy (FA), particularly on molecular mechanisms and disease endotypes, recent developments in global strategies for the management of patients, pipeline for future treatments, primary and secondary prevention and psychosocial aspects. During the recent years, there has been major advances in personalized/precision medicine linked to better understanding of disease pathophysiology and precision treatment options of AD. A greater understanding of the molecular and cellular mechanisms of AD through substantial progress in epidemiology, genetics, skin immunology and psychological aspects resulted in advancements in the precision management of AD. However, the implementation of precision medicine in the management of AD still requires the validation of reliable biomarkers, which will provide more tailored management, starting from prevention strategies towards targeted therapies for more severe diseases. Cutaneous exposure to food via defective barriers is an important route of sensitization to food allergens. Studies on the role of the skin barrier genes demonstrated their association with the development of IgE-mediated FA, and suggest novel prevention and treatment strategies for type 2 diseases in general because of their link to barrier defects not only in AD and FA, but also in asthma, chronic rhinosinusitis, allergic rhinitis and inflammatory bowel disease. The development of more accurate diagnostic tools, biomarkers for early prediction, and innovative solutions require a better understanding of molecular mechanisms and the pathophysiology of FA. Based on these developments, this review provides an overview of novel developments and advances in AD and FA, which are reported particularly during the last two years.

Exploratory analysis of plasma cytokine/chemokine levels in 6-year-old children from a birth cohort study

This study aimed to reveal a new dimension of allergy profiles in the general population by using machine learning to explore complex relationships among various cytokines/chemokines and allergic diseases (asthma and atopic dermatitis; AD). We examined the symptoms related to asthma and AD and the plasma levels of 72 cytokines/chemokines obtained from a general population of 161 children at 6 years of age who participated in a pilot birth cohort study of the Japan Environment and Children's Study (JECS). The children whose signs and symptoms fulfilled the criteria of AD, which are mostly based on questionnaire including past symptoms, tended to have higher levels of the two chemokine ligands, CCL17 and CCL27, which are used for diagnosis of AD. On the other hand, another AD-related chemokine CCL22 level in plasma was higher only in children with visible flexural eczema, which is one of AD diagnostic criteria but was judged on the same day of blood examination unlike other criteria. Here, we also developed an innovative method of machine learning for elucidating the complex cytokine/chemokine milieu related to symptoms of allergic diseases by using clustering analysis based on the random forest dissimilarity measure that relies on artificial intelligence (AI) technique. To our surprise, the majority of children showing at least any asthma-related symptoms during the last month were divided by AI into the two clusters, either cluster-2 having elevated levels of IL-33 (related to eosinophil activation) or cluster-3 having elevated levels of CXCL7/NAP2 (related to neutrophil activation), among the total three clusters. Future studies will clarify better approach for allergic diseases by endotype classification.

A Precision Medicine Approach to Rhinitis Evaluation and Management

PURPOSE OF REVIEW

Precision medicine (PM) represents a new paradigm in disease diagnosis, prevention, and treatment. The PM approach focuses on the characterization of different phenotypes and pathogenic pathways in order to allow the selection of specific biomarkers that will be useful in disease management. Rhinitis is a highly prevalent and heterogeneous disease, both in terms of underlying endotypes and clinical presentations. Therefore, to apply the PM principles to the various rhinitis subtypes rise as a meaningful strategy to improve evaluation and treatment.

RECENT FINDINGS

The technology of recombinant allergens has allowed molecular characterization of IgE reactivity of specific individual components of allergenic extracts. Recently published and ongoing clinical trials based on component resolved diagnosis (CRD) bring more precision to allergen immunotherapy for allergic rhinitis. Monoclonal antibodies against various cytokines involved in inflammatory allergic and nonallergic rhinitis endotypes show promissory results.

SUMMARY

Better understanding of pathogenic pathways together with an accurate phenotype classification of patients presented with rhinitis symptoms contributes to point out clinical usefulness of biomarkers and other diagnostic tools, which leads to more accurate environmental control measures, personalized pharmacologic options, and new biological therapy developments.

Current and emerging biologic therapies for allergic rhinitis and chronic rhinosinusitis

Introduction: Allergic rhinitis and chronic rhinosinusitis, with and without nasal polyps, are the most common chronic inflammatory diseases of the upper airways. They both cause relevant respiratory symptoms and a substantial detriment to patients' quality of life, mainly in uncontrolled and severe patients.Areas covered: This review aims to present the most recent evidence on current and emerging biologic therapies for allergic rhinitis and chronic rhinosinusitis and discuss their potential implementation in clinical practice. To select relevant literature for inclusion in this review, we conducted a literature search using the PubMed database, using terms 'biologics OR biological agents', 'allergic rhinitis' and 'chronic rhinosinusitis'. The literature review was performed for publication years 2009-2019, restricting the articles to humans and English language publications.Expert opinion: Biological therapies represent a potential step forward in providing individualized care for all patients with uncontrolled severe upper airway diseases. Biologics recently showed promising results for the treatment of severe uncontrolled allergic rhinitis and chronic rhinosinusitis with nasal polyps with or without associated asthma. Endotyping inflammatory pathways and identifying related biomarkers remain the major challenge for positioning biologics in the care pathway of chronic respiratory diseases.

Obesity and disease severity magnify disturbed microbiome-immune interactions in asthma patients

In order to improve targeted therapeutic approaches for asthma patients, insights into the molecular mechanisms that differentially contribute to disease phenotypes, such as obese asthmatics or severe asthmatics, are required. Here we report immunological and microbiome alterations in obese asthmatics (n = 50, mean age = 45), non-obese asthmatics (n = 53, mean age = 40), obese non-asthmatics (n = 51, mean age = 44) and their healthy counterparts (n = 48, mean age = 39). Obesity is associated with elevated proinflammatory signatures, which are enhanced in the presence of asthma. Similarly, obesity or asthma induced changes in the composition of the microbiota, while an additive effect is observed in obese asthma patients. Asthma disease severity is negatively correlated with fecal Akkermansia muciniphila levels. Administration of A. muciniphila to murine models significantly reduces airway hyper-reactivity and airway inflammation. Changes in immunological processes and microbiota composition are accentuated in obese asthma patients due to the additive effects of both disease states, while A. muciniphila may play a non-redundant role in patients with a severe asthma phenotype.

Asthma and/or hay fever as predictors of fertility/impaired fecundity in U.S. women: National Survey of Family Growth

This study addresses whether asthma and/or hay fever predict fertility and impaired fecundity. The lifetime number of pregnancies (fertility) and spontaneous pregnancy losses (impaired fecundity) in 10,847 women representative of the U.S. population 15 to 44 years of age with histories of diagnosed asthma and/or hay fever are analyzed in the 1995 National Survey of Family Growth using multivariable Poisson regression with multiple covariates and adjustments for complex sampling. Smokers have significantly increased fertility compared to nonsmokers. Smokers with asthma only have significantly increased fertility compared to other smokers. Higher fertility is associated with impaired fecundity (ectopic pregnancy, miscarriage, stillbirth). Women with asthma (with and without hay fever) have significantly higher pregnancy losses than women without asthma. With increasing number of pregnancies, smokers have increased pregnancy losses compared to nonsmokers. Smokers, especially those with asthma only, have increased fertility and require special attention as to their family planning needs, reproductive health, and smoking cessation. Women with asthma, regardless of number of pregnancies, and smokers with higher numbers of pregnancies have high risk pregnancies that require optimal asthma/medical management prenatally and throughout pregnancy. Whether a proinflammatory asthma endotype underlies both the increased fertility and impaired fecundity associated with age and smoking is discussed.

Severe Atopic Dermatitis In Spain: A Real-Life Observational Study

Objective

To determine the epidemiology and characterize the treatment prescribed for severe atopic dermatitis (AD) in children/adults in usual clinical practice.

Methods

Observational, retrospective study made through review of medical records of Spanish patients aged ≥6 years. Patients diagnosed with severe AD who required care between 2013 and 2017 were included. The study groups were: 6–12 years; 13–18 years; and > 18 years. Patients were followed for 5 years. The main measurements were the prevalence of AD, comorbidity and treatment duration. Statistical significance was established as p <0.05.

Results

We included 2323 patients with severe AD. The overall prevalence was 0.10% (95% CI: 0.09–0.11%) and was 0.39%, 0.23% and 0.07% in the 6–12 years, 13–18 years and >18 years age groups, respectively (p <0.001), the percentage of males was 58%, 48.6% and 39%, respectively, and general comorbidity was 0.1, 0.2 and 0.9 points, respectively (p <0.001).The most frequent comorbidities were asthma in 49.0%, 44.9% and 20.8%, respectively (p <0.001), and anxiety in 79.7%, 65.8% and 67.3%, respectively (p <0.001). Oral corticosteroids were administered in 97.3%, 90.9% and 81.7%, respectively (concomitant-medication). Cyclosporine (45.3%), azathioprine (15.9%) and methotrexate (9.0%) were the most frequently prescribed drugs; biologic agents were administered in 5.8% of patients (for AD).

Conclusion

In AD the presence of comorbidities was significant, especially in the psychological, immunoallergic and cardiovascular areas. Cyclosporine was the most widely used immunosuppressant. There was a degree of variability in the use and duration of the treatments prescribed.

Perspectives in allergen immunotherapy: 2019 and beyond

The seventh "Future of the Allergists and Specific Immunotherapy (FASIT)" workshop held in 2019 provided a platform for global experts from academia, allergy clinics, regulatory authorities and industry to review current developments in the field of allergen immunotherapy (AIT). Key domains of the meeting included the following: (a) Biomarkers for AIT and allergic asthma; (b) visions for the future of AIT; (c) progress and data for AIT in asthma and the updates of GINA and EAACI Asthma Guidelines (separated for house dust mite SCIT, SLIT tablets and SLIT drops; patient populations) including a review of clinically relevant endpoints in AIT studies in asthma; (d) regulatory prerequisites such as the "Therapy Allergen Ordinance" in Germany; (e) optimization of trial design in AIT clinical research; (f) challenges planning and conducting phase III (field) studies and the future role of Allergen Exposure Chambers (AEC) in AIT product development from the regulatory point of view. We report a summary of panel discussions of all six domains and highlight unmet needs and possible solutions for the future.

Prioritizing research challenges and funding for allergy and asthma and the need for translational research-The European Strategic Forum on Allergic Diseases

The European Academy of Allergy and Clinical Immunology (EAACI) organized the first European Strategic Forum on Allergic Diseases and Asthma. The main aim was to bring together all relevant stakeholders and decision-makers in the field of allergy, asthma and clinical Immunology around an open debate on contemporary challenges and potential solutions for the next decade. The Strategic Forum was an upscaling of the EAACI White Paper aiming to integrate the Academy's output with the perspective offered by EAACI's partners. This collaboration is fundamental for adapting and integrating allergy and asthma care into the context of real-world problems. The Strategic Forum on Allergic Diseases brought together all partners who have the drive and the influence to make positive change: national and international societies, patients' organizations, regulatory bodies and industry representatives. An open debate with a special focus on drug development and biomedical engineering, big data and information technology and allergic diseases and asthma in the context of environmental health concluded that connecting science with the transformation of care and a joint agreement between all partners on priorities and needs are essential to ensure a better management of allergic diseases and asthma in the advent of precision medicine together with global access to innovative and affordable diagnostics and therapeutics.

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.