New Targeted Therapies for Uncontrolled Asthma

Prostaglandin D2 receptor 2 downstream signaling and modulation of type 2 innate lymphoid cells from patients with asthma

Increased production of Prostaglandin D2 (PGD2) is linked to development and progression of asthma and allergy. PGD2 is rapidly degraded to its metabolites, which initiate type 2 innate lymphoid cells (ILC2) migration and IL-5/IL-13 cytokine secretion in a PGD2 receptor 2 (DP2)-dependent manner. Blockade of DP2 has shown therapeutic benefit in subsets of asthma patients. Cellular mechanisms of ILC2 activity in response to PGD2 and its metabolites are still unclear. We hypothesized that ILC2 respond non-uniformly to PGD2 metabolites. ILC2s were isolated from peripheral blood of patients with atopic asthma. ILC2s were stimulated with PGD2 and four PGD2 metabolites (Δ12-PGJ2, Δ12-PGD2, 15-deoxyΔ12,14-PGD2, 9α,11β-PGF2) with or without the selective DP2 antagonist fevipiprant. Total RNA was sequenced, and differentially expressed genes (DEG) were identified by DeSeq2. Differential gene expression analysis revealed an upregulation of pro-inflammatory DEGs in ILC2s stimulated with PGD2 (14 DEGs), Δ12-PGD2 (27 DEGs), 15-deoxyΔ12,14-PGD2 (56 DEGs) and Δ12-PGJ2 (136 DEGs), but not with 9α,11β-PGF2. Common upregulated DEGs were i.e. ARG2, SLC43A2, LAYN, IGFLR1, or EPHX2. Inhibition of DP2 via fevipiprant mainly resulted in downregulation of pro-inflammatory genes such as DUSP4, SPRED2, DUSP6, ETV1, ASB2, CD38, ADGRG1, DDIT4, TRPM2, or CD69. DEGs were related to migration and various immune response-relevant pathways such as "chemokine (C-C motif) ligand 4 production", "cell migration", "interleukin-13 production", "regulation of receptor signaling pathway via JAK-STAT", or "lymphocyte apoptotic process", underlining the pro-inflammatory effects of PGD2 metabolite-induced immune responses in ILC2s as well as the anti-inflammatory effects of DP2 inhibition via fevipiprant. Furthermore, PGD2 and metabolites showed distinct profiles in ILC2 activation. Overall, these results expand our understanding of DP2 initiated ILC2 activity.

Real-World Safety Profile of Biologic Drugs for Severe Uncontrolled Asthma: A Descriptive Analysis from the Spanish Pharmacovigilance Database

Background: The present investigation provides a thorough analysis of adverse drug reactions (ADRs) reported in the Database of the Spanish Pharmacovigilance System (FEDRA) for biologic medications primarily indicated for severe refractory asthma, including omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab, and tezepelumab. Our main objective was to identify ADRs not documented in the drugs' Technical Sheets (summary of product characteristics, SmPC), potentially indicating unrecognized risks meriting pharmacovigilance attention. Methods: Data spanning from each drug's market introduction until 22 January 2024, were analyzed, sourced from direct submissions to the Spanish Pharmacovigilance System, industry communications, and literature reviews. We evaluated notifications impartially to ensure a comprehensive review of all the ADRs associated with these medications. Results: This investigation underlines the critical role of post-marketing surveillance in enhancing patient safety. It emphasizes the necessity for healthcare professionals to report ADRs comprehensively to foster a robust pharmacovigilance system. Furthermore, the study highlights gaps between the reported ADRs and the information provided in SmPCs, signaling potential areas for improvement in drug safety monitoring and regulatory oversight. Conclusions: Finally, these findings may contribute to informed decision making in clinical practice and regulatory policy, ultimately advancing patient care and safety in the management of severe uncontrolled asthma.

Correlation between LTC4S -444 A>C polymorphism and susceptibility to asthma: A meta-analysis and trial sequential analysis

Background

This study aims to uncover the potential correlation between LTC4S -444 A>C polymorphism and susceptibility to asthma.

Methods

Literatures reporting the correlation between LTC4S -444 A>C polymorphism and susceptibility to asthma published before 1st June, 2019 were searched in PubMed, Embase, Cochrane, Wanfang and CNKI. Eligible literatures were enrolled and their data were extracted. OR and its 95% CI were calculated for assessing the correlation between LTC4S -444 A>C polymorphism and susceptibility to asthma. The included data were weighted by an inverse variance and then analyzed by a fixed or random effects model. Heterogeneity test and sensitivity analysis were performed on the enrolled reports. STATA12.1 and TSA (trial sequential analysis) were utilized for analyses.

Epithelial SIRT6 governs IL-17A pathogenicity and drives allergic airway inflammation and remodeling

Dysregulation of IL-17A is closely associated with airway inflammation and remodeling in severe asthma. However, the molecular mechanisms by which IL-17A is regulated remain unclear. Here we identify epithelial sirtuin 6 (SIRT6) as an epigenetic regulator that governs IL-17A pathogenicity in severe asthma. Mice with airway epithelial cell-specific deletion of Sirt6 are protected against allergen-induced airway inflammation and remodeling via inhibiting IL-17A-mediated inflammatory chemokines and mesenchymal reprogramming. Mechanistically, SIRT6 directly interacts with RORγt and mediates RORγt deacetylation at lysine 192 via its PPXY motifs. SIRT6 promotes RORγt recruitment to the IL-17A gene promoter and enhances its transcription. In severe asthma patients, high expression of SIRT6 positively correlates with airway remodeling and disease severity. SIRT6 inhibitor (OSS_128167) treatment significantly attenuates airway inflammation and remodeling in mice. Collectively, these results uncover a function for SIRT6 in regulating IL-17A pathogenicity in severe asthma, implicating SIRT6 as a potential therapeutic target for severe asthma.

A real-world pharmacovigilance study of mepolizumab in the FDA adverse event reporting system (FAERS) database

Mepolizumab is primarily used in the treatment of asthma, eosinophilic granulomatosis with polyangiitis, eosinophilia syndrome, and chronic rhinitis with nasal polyps. The information about its adverse drug reactions is mainly derived from clinical trials, and there is a shortage of real-world studies with extensive sample sizes. In this study, the U.S. FDA's Adverse Event Reporting System (FAERS) database was analyzed to evaluate the side effects of mepolizumab. A total of 18,040 reports of mepolizumab-associated adverse events were identified from the FDA Adverse Event Reporting System database. Multiple disproportionality analysis algorithms were used to determine the significance of these AEs. The study identified 198 instances of mepolizumab-induced AEs, including some important AEs not mentioned in the product labeling. The time to onset of adverse reactions was also analyzed, with a median time of 109 days. Most AEs occurred within the first month of mepolizumab use, but some may still occur after 1 year of treatment. Gender-specific analysis showed different high-risk AEs for females (digestive and neurological side effects) and males (serious adverse effects leading to hospitalization and death). The findings mentioned provide valuable insights on optimizing the use of mepolizumab, enhancing its effectiveness, and minimizing potential side effects. This information will greatly contribute to the practical implementation of the drug in clinical settings.

Thymic Stromal Lymphopoietin (TSLP), Its Isoforms and the Interplay with the Epithelium in Allergy and Asthma

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine that has emerged as a critical player in the development and progression of allergy and asthma. It is primarily produced by epithelial cells and functions as a potent immune system activator. TSLP acts through interaction with its receptor complex, composed of the TSLP receptor (TSLPR) and interleukin-7 receptor alpha chain (IL-7Rα), activating downstream complex signalling pathways. The TSLP major isoform, known as long-form TSLP (lfTSLP), is upregulated in the airway epithelium of patients with allergic diseases. More research is warranted to explore the precise mechanisms by which short-form TSLP (sfTSLP) regulates immune responses. Understanding the dynamic interplay between TSLP and the dysfunctional epithelium provides insights into the mechanisms underlying allergy and asthma pathogenesis. Targeting TSLP represents an important therapeutic strategy, as it may upstream disrupt the inflammatory cascade and alleviate symptoms associated with allergic inflammation.

Optimization and Characterization of Novel ALCAM-Targeting Antibody Fragments for Transepithelial Delivery

Activated leukocyte cell adhesion molecule (ALCAM) is a cell adhesion molecule that supports T cell activation, leukocyte migration, and (lymph)angiogenesis and has been shown to contribute to the pathology of various immune-mediated disorders, including asthma and corneal graft rejection. In contrast to monoclonal antibodies (mAbs) targeting ALCAM's T cell expressed binding partner CD6, no ALCAM-targeting mAbs have thus far entered clinical development. This is likely linked with the broad expression of ALCAM on many different cell types, which increases the risk of eliciting unwanted treatment-induced side effects upon systemic mAb application. Targeting ALCAM in surface-exposed tissues, such as the lungs or the cornea, by a topical application could circumvent this issue. Here, we report the development of various stability- and affinity-improved anti-ALCAM mAb fragments with cross-species reactivity towards mouse, rat, monkey, and human ALCAM. Fragments generated in either mono- or bivalent formats potently blocked ALCAM-CD6 interactions in a competition ELISA, but only bivalent fragments efficiently inhibited ALCAM-ALCAM interactions in a leukocyte transmigration assay. The different fragments displayed a clear size-dependence in their ability to penetrate the human corneal epithelium. Furthermore, intranasal delivery of anti-ALCAM fragments reduced leukocyte infiltration in a mouse model of asthma, confirming ALCAM as a target for topical application in the lungs.

Severe Asthmatic Responses: The Impact of TSLP

Asthma is a chronic inflammatory disease that affects the lower respiratory system and includes several categories of patients with varying features or phenotypes. Patients with severe asthma (SA) represent a group of asthmatics that are poorly responsive to medium-to-high doses of inhaled corticosteroids and additional controllers, thus leading in some cases to life-threatening disease exacerbations. To elaborate on SA heterogeneity, the concept of asthma endotypes has been developed, with the latter being characterized as T2-high or low, depending on the type of inflammation implicated in disease pathogenesis. As SA patients exhibit curtailed responses to standard-of-care treatment, biologic therapies are prescribed as adjunctive treatments. To date, several biologics that target specific downstream effector molecules involved in disease pathophysiology have displayed superior efficacy only in patients with T2-high, eosinophilic inflammation, suggesting that upstream mediators of the inflammatory cascade could constitute an attractive therapeutic approach for difficult-to-treat asthma. One such appealing therapeutic target is thymic stromal lymphopoietin (TSLP), an epithelial-derived cytokine with critical functions in allergic diseases, including asthma. Numerous studies in both humans and mice have provided major insights pertinent to the role of TSLP in the initiation and propagation of asthmatic responses. Undoubtedly, the magnitude of TSLP in asthma pathogenesis is highlighted by the fact that the FDA recently approved tezepelumab (Tezspire), a human monoclonal antibody that targets TSLP, for SA treatment. Nevertheless, further research focusing on the biology and mode of function of TSLP in SA will considerably advance disease management.

Pathogenesis of allergic diseases and implications for therapeutic interventions

Allergic diseases such as allergic rhinitis (AR), allergic asthma (AAS), atopic dermatitis (AD), food allergy (FA), and eczema are systemic diseases caused by an impaired immune system. Accompanied by high recurrence rates, the steadily rising incidence rates of these diseases are attracting increasing attention. The pathogenesis of allergic diseases is complex and involves many factors, including maternal-fetal environment, living environment, genetics, epigenetics, and the body's immune status. The pathogenesis of allergic diseases exhibits a marked heterogeneity, with phenotype and endotype defining visible features and associated molecular mechanisms, respectively. With the rapid development of immunology, molecular biology, and biotechnology, many new biological drugs have been designed for the treatment of allergic diseases, including anti-immunoglobulin E (IgE), anti-interleukin (IL)-5, and anti-thymic stromal lymphopoietin (TSLP)/IL-4, to control symptoms. For doctors and scientists, it is becoming more and more important to understand the influencing factors, pathogenesis, and treatment progress of allergic diseases. This review aimed to assess the epidemiology, pathogenesis, and therapeutic interventions of allergic diseases, including AR, AAS, AD, and FA. We hope to help doctors and scientists understand allergic diseases systematically.

Treatment Strategy of Uncontrolled Chronic Rhinosinusitis with Nasal Polyps: A Review of Recent Evidence

Chronic rhinosinusitis (CRS) is recognized as a heterogeneous disease with a wide range of clinical features, resulting in significant morbidity and cost to the healthcare system. While the phenotypic classification is determined by the presence or absence of nasal polyps and comorbidities, the endotype classification has been established based on molecular biomarkers or specific mechanisms. Research on CRS has now developed based on information based on three major endotypes: types 1, 2, and 3. Recently, biological therapies targeting type 2 inflammation have been clinically expanded and may be applied to other inflammatory endotypes in the future. The purpose of this review is to discuss the treatment options according to the type of CRS and summarize recent studies on new therapeutic approaches for patients with uncontrolled CRS with nasal polyps.

Progress in diagnosis and treatment of difficult-to-treat asthma in children

At present, medications containing inhaled corticosteroids (ICS-containing) are the keystones of asthma treatment. The majority of asthmatic children can significantly improve clinical outcomes with little worsening by standardized inhaled glucocorticoid treatment, but there is still a small proportion of children who are unable to achieve good symptom control even after the maximum standardized treatment, known as 'children with difficult-to-treat asthma (DA)'. The high heterogeneity of DA makes therapy challenging and expensive, which poses a serious risk to children's health and makes it extremely difficult for clinical physicians to accurately identify and treat children with DA. This article reviews the definition, evaluation, and treatment of this asthma in order to provide a reference for optimal clinical decision-making.

CD6-mediated inhibition of T cell activation via modulation of Ras

BACKGROUND

CD6 is one of many cell surface receptors known to regulate signal transduction upon T cell activation. However, whether CD6 mediates costimulatory or inhibitory signals is controversial. When T cells engage with antigen presenting cells (APCs), CD6 interacts with its ligand CD166 at the cell-cell interface while the cytosolic tail assembles a complex signalosome composed of adaptors and effector enzymes, that may either trigger activating signaling cascades, or instead modulate the intensity of signaling. Except for a few cytosolic adaptors that connect different components of the CD6 signalosome, very little is known about the mechanistic effects of the cytosolic effectors that bind CD6.

METHODS

Jurkat model T cells were transfected to express wild-type (WT) CD6, or a cytoplasmic truncation, signaling-disabled mutant, CD6Δcyt. The two resulting cell lines were directly activated by superantigen (sAg)-loaded Raji cells, used as APCs, to assess the net signaling function of CD6. The Jurkat cell lines were further adapted to express a FRET-based unimolecular HRas biosensor that reported the activity of this crucial GTPase at the immunological synapse.

RESULTS

We show that deletion of the cytosolic tail of CD6 enhances T-cell responses, indicating that CD6 restrains T-cell activation. One component of the CD6-associated inhibitory apparatus was found to be the GTPase activating protein of Ras (RasGAP), that we show to associate with CD6 in a phosphorylation-dependent manner. The FRET HRas biosensor that we developed was demonstrated to be functional and reporting the activation of the T cell lines. This allowed to determine that the presence of the cytosolic tail of CD6 results in the down-regulation of HRas activity at the immunological synapse, implicating this fundamental GTPase as one of the targets inhibited by CD6.

CONCLUSIONS

This study provides the first description of a mechanistic sequence of events underlying the CD6-mediated inhibition of T-cell activation, involving the modulation of the MAPK pathway at several steps, starting with the coupling of RasGAP to the CD6 signalosome, the repression of the activity of Ras, and culminating in the reduction of ERK1/2 phosphorylation and of the expression of the T-cell activation markers CD69 and IL-2R α chain. Video abstract.

Comparison between clinical trials and real-world evidence studies on biologics for severe asthma

In recent years, the more widespread availability of biological drugs with specific mechanisms of action has led to significant breakthroughs in the management of severe asthma. Over time, numerous randomised clinical trials have been conducted to evaluate the efficacy and safety of these biologics and define the eligibility criteria of patients suitable for various therapeutic options. These studies were conducted under controlled conditions not always applicable to real life. For this and other reasons, real-world evidence and pragmatic studies are required to provide useful information on the effectiveness of biological drugs and their safety, even in the long term. Because differences in outcomes have sometimes emerged between clinical trials and real-life studies, it is important to clarify the causes of these discrepancies and define the significance of the results of studies conducted in the course of daily clinical practice. Thus, a scientific debate is ongoing, and no consensus has been reached. The purpose of this narrative review is to analyse the differences between randomised trials and real-world evidence studies, focusing on their roles in guiding clinicians among different therapeutic options and understanding the reasons for the large discrepancies often found in the results obtained.

Blockade of Tyrosine Kinase, LCK Leads to Reduction in Airway Inflammation through Regulation of Pulmonary Th2/Treg Balance and Oxidative Stress in Cockroach Extract-Induced Mouse Model of Allergic Asthma

Asthma is one of the most common inflammatory diseases affecting the airways. Approximately 300 million individuals suffer from asthma around the world. Allergic immune responses in the asthmatic airways are predominantly driven by Th2 cells and eosinophils. Lymphocyte-specific protein tyrosine kinase (LCK) is a non-receptor tyrosine kinase which regulates several key intracellular events through phosphorylation of its substrates. Some of the intracellular signaling pathways activated by LCK phosphorylation help in differentiation of Th2 cells which secrete allergic cytokines that amplify airway inflammation. Therefore, this investigative study was designed to determine the role of LCK in a cockroach extract (CE)-induced airway inflammation murine model of allergic asthma. Further, the effect of a pharmacological LCK inhibitor, A-770041, on allergic airway inflammation and key intracellular pathways in CD4+ T cells was assessed. Our data exhibit that there is an activation of LCK during allergic airway inflammation as depicted by increased p-LCK levels in CD4+ T cells. Activated LCK is involved in the activation of ITK, PLC-γ, GATA3, NFkB, and NFATc1. Activated LCK is also involved in the upregulation of Th2 related cytokines, such as IL-4/IL-5/IL-13 and oxidative stress, and the downregulation of Treg cells. Furthermore, utilization of LCK inhibitor causes the reduction in p-LCK, PLC-γ, GATA3, and NFATc1 as well as Th2 cytokines and oxidative stress. LCK inhibitor causes upregulation of Treg cells in allergic mice. LCK inhibitor also caused a reduction in CE-induced airway inflammation and mucus secretion. Therefore, the inhibition of LCK signaling could be a fruitful approach to adjust allergic airway inflammation through the attuning of Th2/Treg immune responses. This study could lead to the design of newer treatment options for better management of allergic inflammation in asthma.

Conventional and pathogenic Th2 cells in inflammation, tissue repair, and fibrosis

Type 2 helper T (Th2) cells, a subset of CD4⁺ T cells, play an important role in the host defense against pathogens and allergens by producing Th2 cytokines, such as interleukin-4 (IL-4), IL-5, and IL-13, to trigger inflammatory responses. Emerging evidence reveals that Th2 cells also contribute to the repair of injured tissues after inflammatory reactions. However, when the tissue repair process becomes chronic, excessive, or uncontrolled, pathological fibrosis is induced, leading to organ failure and death. Thus, proper control of Th2 cells is needed for complete tissue repair without the induction of fibrosis. Recently, the existence of pathogenic Th2 (Tpath2) cells has been revealed. Tpath2 cells produce large amounts of Th2 cytokines and induce type 2 inflammation when activated by antigen exposure or tissue injury. In recent studies, Tpath2 cells are suggested to play a central role in the induction of type 2 inflammation whereas the role of Tpath2 cells in tissue repair and fibrosis has been less reported in comparison to conventional Th2 cells. In this review, we discuss the roles of conventional Th2 cells and pathogenic Th2 cells in the sequence of tissue inflammation, repair, and fibrosis.

Signaling and functions of interleukin-33 in immune regulation and diseases

Interleukin-33 (IL-33) which belongs to the interleukin-1 (IL-1) family is an alarmin cytokine with critical roles in tissue homeostasis, pathogenic infection, inflammation, allergy and type 2 immunity. IL-33 transmits signals through its receptor IL-33R (also called ST2) which is expressed on the surface of T helper 2 (Th2) cells and group 2 innate lymphoid cells (ILC2s), thus inducing transcription of Th2-associated cytokine genes and host defense against pathogens. Moreover, the IL-33/IL-33R axis is also involved in development of multiple types of immune-related diseases. In this review, we focus on current progress on IL-33-trigggered signaling events, the important functions of IL-33/IL-33R axis in health and diseases as well as the promising therapeutic implications of these findings.

Integrated systems modeling of severe asthma: Exploration of IL-33/ST2 antagonism

Asthma is a complex, heterogeneous disease with a high unmet medical need, despite therapies targeting a multitude of pathways. The ability to quantitatively integrate preclinical and clinical data on these pathways could aid in the development and testing of novel targets and therapeutics. In this work, we develop a computational model of asthma biology, including key cell types and mediators, and create a virtual population capturing clinical heterogeneity. The simulated responses to therapies targeting IL-13, IL-4Rα, IL-5, IgE, and TSLP demonstrate agreement with clinical endpoints and biomarkers of type 2 (T2) inflammation, including blood eosinophils, FEV1, IgE, and FeNO. We use the model to explore the potential benefit of targeting the IL-33 pathway with anti-IL-33 and anti-ST2. Model predictions are compared with data on blood eosinophils, FeNO, and FEV1 from recent anti-IL-33 and anti-ST2 trials and used to interpret trial results based on pathway biology and pharmacology. Results of sensitivity analyses on the contributions of IL-33 to the predicted biomarker changes suggest that anti-ST2 therapy reduces circulating blood eosinophil levels primarily through its impact on eosinophil progenitor maturation and IL-5-dependent survival, and induces changes in FeNO and FEV1 through its effect on immune cells involved in T2 cytokine production. Finally, we also investigate the impact of ST2 genetics on the conferred benefit of anti-ST2. The model includes representation of a wide array of biologic mechanisms and interventions that will provide mechanistic insight and support clinical program design for a wide range of novel therapies during drug development.

Biologics in severe asthma: the role of real-world evidence from registries

Asthma is one of the most common noncommunicable diseases; in the majority of patients it is well controlled with inhaled bronchodilators and inhaled corticosteroids, but the management of severe asthma has been a significant challenge historically. The introduction of novel biologic drugs in the past few decades has revolutionised the field, presenting physicians with a variety of biologic drugs with different mechanisms for the treatment of severe asthma.It is of crucial importance to evaluate the effectiveness of these drugs by following their "real-life" effectiveness rather than relying solely on their efficacy, established in carefully designed clinical trials, which therefore do not necessarily match the profile of the real-life patient. Understanding the actual effectiveness of the specific drugs in real-life patients is a crucial part of tailoring the right drugs to the right patients. Registries serve as an important tool in obtaining real-life evidence, since they are in effect observational studies, following the entire patient population.

Exploring the efficacy and contribution of Dupilumab in asthma management

IgG4 monoclonal antibody Dupilumab binds to the alpha chain (IL4R) of both types of the ligand-binding domains (IL4R/ IL13R1; equally IL4 and IL13 specific) of the IL-4 receptor. The current focus on precision medicine techniques to blocking pathways implicated in allergy disorders is crucial to the development of Dupilumab and broadening its therapeutic uses. Our review describes how the IL-4R complexes signaling pathway works, explores the probable mechanisms of Dupilumab activity and addresses its clinical usefulness and safety in asthma. The FDA (Food and Drug Administration) already licences it to treat Alzheimer's disease and moderate-to-severe asthma, and it has shown highly significant results in the management of chronic rhinosinusitis and Eosinophilic esophagitis (EoE). Previous investigations and clinical trials undertaken by various pharmaceutical firms are examined in this review article to assess the existing literature fully. The discovery of Dupilumab and the expanding range of therapeutic uses are pertinent to the current focus on precision medicine methods to blocking asthma-related pathways.

Endotypes of chronic rhinosinusitis: Relationships to disease phenotypes, pathogenesis, clinical findings, and treatment approaches

Chronic rhinosinusitis (CRS) is a common clinical syndrome that produces significant morbidity and costs to our health system. The study of CRS has progressed from an era focused on phenotype to include endotype-based information. Phenotypic classification has identified clinical heterogeneity in CRS based on endoscopically observed features such as presence of nasal polyps, presence of comorbid or systemic diseases, and timing of disease onset. More recently, laboratory-based findings have established CRS endotype based upon specific mechanisms or molecular biomarkers. Understanding the basis of widespread heterogeneity in the manifestations of CRS is advanced by findings that the three main endotypes, Type 1, 2, and 3, orchestrate the expression of three distinct large sets of genes. The development and use of improved methods of endotyping disease in the clinic are ushering in an expansion of the use of biological therapies targeting Type 2 inflammation now and perhaps other inflammatory endotypes in the near future. The purpose of this review is to discuss the phenotypic and endotypic heterogeneity of CRS from the perspective of advancing the understanding of the pathogenesis and improvement of treatment approaches and outcomes.

Potential cellular endocrinology mechanisms underlying the effects of Chinese herbal medicine therapy on asthma

Asthma is a complex syndrome with polygenetic tendency and multiple phenotypes, which has variable expiratory airflow limitation and respiratory symptoms that vary over time and in intensity. In recent years, continuous industrial development has seriously impacted the climate and air quality at a global scale. It has been verified that climate change can induce asthma in predisposed individuals and that atmospheric pollution can exacerbate asthma severity. At present, a subset of patients is resistant to the drug therapy for asthma. Hence, it is urgent to find new ideas for asthma prevention and treatment. In this review, we discuss the prescription, composition, formulation, and mechanism of traditional Chinese medicine monomer, traditional Chinese medicine monomer complex, single herbs, and traditional Chinese patent medicine in the treatment of asthma. We also discuss the effects of Chinese herbal medicine on asthma from the perspective of cellular endocrinology in the past decade, emphasizing on the roles as intracellular and extracellular messengers of three substances-hormones, substances secreted by pulmonary neuroendocrine cells, and neuroendocrine-related signaling protein-which provide the theoretical basis for clinical application and new drug development.

Emerging therapeutic options in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic disease that requires chronic treatment throughout the evolution of the disease, with a complex physiopathology that entails great challenges for the development of new and specific treatments for ulcerative colitis and Crohn´s disease. The anti-tumor necrosis factor alpha therapy has impacted the clinical course of IBD in those patients who do not respond to conventional treatment, so there is a need to develop new therapies and markers of treatment response. Various pathways involved in the development of the disease are known and the new therapies have focused on blocking the inflammatory process at the gastrointestinal level by oral, intravenous, subcutaneous, and topical route. All these new therapies can lead to more personalized treatments with higher success rates and fewer relapses. These treatments have not only focused on clinical remission, but also on achieving macroscopic changes at the endoscopic level and microscopic changes by achieving mucosal healing. These treatments are mainly based on modifying signaling pathways, by blocking receptors or ligands, reducing cell migration and maintaining the integrity of the epithelial barrier. Therefore, this review presents the efficacy and safety of the new treatments that are currently under study and the advances that have been made in this area in recent years.

Moving towards a Treatable Traits model of care for the management of obstructive airways diseases

Asthma and chronic obstructive pulmonary disease (COPD) are two prevalent chronic airways diseases. Both are complex and heterogeneous. Traditionally, clinical guidelines have advocated a stepwise approach to pharmacotherapy of asthma and COPD, but there is increasing realization that both require a more personalized and precise management approach. To this end, a management strategy based on the so-called Treatable Traits has been proposed. Emerging evidence suggests that this model improves relevant outcomes in patients with chronic airway diseases but further research is needed to guide implementation. This review discusses the challenges, opportunities, and hurdles that its implementation will have to face.

PTGDR2 Expression in Peripheral Blood as a Potential Biomarker in Adult Patients with Asthma

Background: Precision medicine is a promising strategy to identify biomarkers, stratify asthmatic patients according to different endotypes, and match them with the appropriate therapy. This proof-of-concept study aimed to investigate whether gene expression in peripheral blood could provide a valuable noninvasive approach for the molecular phenotyping of asthma. Methods: We performed whole-transcriptome RNA sequencing on peripheral blood of 30 non-atopic non-asthmatic controls and 30 asthmatic patients. A quantitative PCR (qPCR) validation study of PTGDR2 that encodes for CRTH2 receptor, expressed in cells involved in T2 inflammation, was developed in a cohort of 361 independent subjects: 94 non-asthmatic non-atopic controls, 187 asthmatic patients [including 82 with chronic rhinosinusitis with nasal polyposis (CRSwNP) and 24 with aspirin-exacerbated respiratory disease (AERD)], 52 with allergic rhinitis, and 28 with CRSwNP without asthma. Results: PTGDR2 was one of the most differentially overexpressed genes in asthmatic patients’ peripheral blood (p-value 2.64 × 10⁶). These results were confirmed by qPCR in the validation study, where PTGDR2 transcripts were significantly upregulated in asthmatic patients (p < 0.001). This upregulation was mainly detected in some subgroups such as allergic asthma, asthma with CRSwNP, AERD, eosinophilic asthma, and severe persistent asthma. PTGDR2 expression was detected in different blood cell types, and its correlation with eosinophil counts showed differences in some groups of asthmatic patients. Conclusions: We found that PTGDR2 expression levels could identify asthma patients, introduce a minimally invasive biomarker for adult asthma molecular phenotyping, and add additional information to blood eosinophils. Although further studies are required, analyzing PTGDR2 expression levels in peripheral blood of asthmatics might assist in selecting patients for treatment with specific antagonists.

Particulate matter exposure is highly correlated to pediatric asthma exacerbation

Asthma is a heterogeneous disease in which environmental factors play an important role, and the effect of particulate matter (PM) on the occurrence and severity of asthma is drawing more attention. This study aims to identify the correlation between PM and pediatric asthma exacerbation and explore the potential mechanisms. The asthma visits data (N = 16,779,739) in a university-based tertiary children’s hospital from January 2013 to December 2017 were collected, and the relationship between asthma visits and local PM concentration was analyzed. For further study, we established a house dust mite (HDM)-induced allergic airway inflammation model with PM intervention. We detected a correlation between PM concentration and pediatric asthma visits, especially in children under 6 years old. The in vivo data showed that PM aggravated HDM-induced airway inflammation, and IL-33 neutralizing antibody exerted a protective role. Our study suggests that PM is a risk factor in promoting pediatric asthma exacerbation, in which IL-33 might be a promising target.

A Current Perspective of Allergic Asthma: From Mechanisms to Management

Asthma is a result of heterogenous, complex gene-environment interactions with variable clinical phenotypes, inflammation, and remodeling. It affects more than 330 million of people worldwide throughout their educational and working lives, while exacerbations put a heavy cost/burden on productivity. Childhood asthma is characterized by a predominance of allergic sensitization and multimorbidity, while in adults polysensitization has been positively associated with asthma occurrence. Despite significant improvements in recent decades, asthma management remains challenging. Recently, a group of specialists suggested that the term "asthma" should be preferably used as a descriptive term for symptoms. Moreover, type 2 inflammation has emerged as a pivotal disease mechanism including overlapping endotypes of specific IgE production, while type 2-low asthma includes several disease endotypes. Optimal asthma control requires both appropriate pharmacological interventions, tailored to each patient, as well as trigger avoidance measures. Regular monitoring for maintenance of symptom control, preservation of lung function, and detection of treatment-related adverse effects are warranted. Allergen-specific immunotherapy and the advent of new targeted therapies for patients with difficult to control asthma offer diverse treatment options. The current review summarizes up-to-date knowledge on epidemiology, definitions, diagnosis, and current therapeutic strategies.

[Impact of reslizumab on the course of chronic rhinosinusitis in patients with eosinophilic asthma]

Chronic rhinosinusitis (CRS) with polyps is associated with eosinophilic inflammation, in which the key mediator is interleukin - 5 (IL-5) and is often combined with asthma.

RESEARCH OBJECTIVES

To evaluate the therapeutic potential of reslizumab-humanized anti-IL-5 monoclonal antibody for the treatment of CRS with polyps in patients with severe asthma.

PATIENTS AND METHODS

We investigated the cases of 9 patients with severe asthma treated with intravenous reslizumab at a dose of 3 mg per 1 kg of weight with regularity once in 4 weeks. The presence of CRS with polyps was revealed in 7 of 9 patients, SCT scanning of the paranasal sinuses indicated changes in all the patients, 2 patients had symptoms of chronic non-allergic rhinitis (NARES).The treatment effectiveness control was carried out after 6 months from the beginning of the treatment by the dynamics of nasal symptoms (SNOT-22), endoscopic image of the nose, total polyp score (TPS), changes in the SCT of the paranasal sinuses on the Lund-Mackay scale, rhinocytogram, the content of eosinophilic cationic protein in the blood, the level of systemic eosinophilia. The effectiveness of asthma control was assessed by the reduction of the frequency of asthma exacerbations, the need for systemic corticosteroids, spirometry data and Asthma Control Test (ACT) results. Along with a marked improvement in asthma control, 8 out of 9 patients displayed clinical, endoscopic, radiological signs of weakening of nasal symptoms. More significant improvement in asthma control was achieved in patients having CRS with polyps. In the group of patients having CRS with polyps, it was possible to detect anamnestic presence of NARES symptoms in the early stages of the disease. This indicates that NARES can be a precursor to the development of eosinophilic, non-IgE-induced asthma and nasal polyps.

CONCLUSION

Treatment with reslizumab in patients with eosinophilic asthma and concomitant CRS with polyps and chronic non-allergic rhinitis (NARES) leads not only to improved control of asthma symptoms, but also to a significant regression of nasal symptoms.

The Concept of Pathogenic TH2 Cells: Collegium Internationale Allergologicum Update 2021

T helper (TH) cells have evolved into distinct subsets that mediate specific immune responses to protect the host against a myriad of infectious and noninfectious challenges. However, if dysregulated, TH-cell subsets can cause inflammatory disease. Emerging evidence now suggests that human allergic disease is caused by a distinct subpopulation of pathogenic TH2 cells. Pathogenic TH2 cells from different type-2-driven diseases share a core phenotype and show overlapping functional attributes. The unique differentiation requirements, activating signals, and metabolic characteristics of pathogenic TH2 cells are just being discovered. A better knowledge of this particular TH2 cell population will enable the specific targeting of disease-driving pathways in allergy. In this review, we introduce a rational for classifying TH cells into distinct subsets, discuss the current knowledge on pathogenic TH2 cells, and summarize their involvement in allergic diseases.

Longitudinal proteomic profiling of dialysis patients with COVID-19 reveals markers of severity and predictors of death

End-stage kidney disease (ESKD) patients are at high risk of severe COVID-19. We measured 436 circulating proteins in serial blood samples from hospitalised and non-hospitalised ESKD patients with COVID-19 (n = 256 samples from 55 patients). Comparison to 51 non-infected patients revealed 221 differentially expressed proteins, with consistent results in a separate subcohort of 46 COVID-19 patients. Two hundred and three proteins were associated with clinical severity, including IL6, markers of monocyte recruitment (e.g. CCL2, CCL7), neutrophil activation (e.g. proteinase-3), and epithelial injury (e.g. KRT19). Machine-learning identified predictors of severity including IL18BP, CTSD, GDF15, and KRT19. Survival analysis with joint models revealed 69 predictors of death. Longitudinal modelling with linear mixed models uncovered 32 proteins displaying different temporal profiles in severe versus non-severe disease, including integrins and adhesion molecules. These data implicate epithelial damage, innate immune activation, and leucocyte-endothelial interactions in the pathology of severe COVID-19 and provide a resource for identifying drug targets.

Old Friends with Unexploited Perspectives: Current Advances in Mesenchymal Stem Cell-Based Therapies in Asthma

Mesenchymal stem cells (MSCs) have a great regenerative and immunomodulatory potential that was successfully tested in numerous pre-clinical and clinical studies of various degenerative, hematological and inflammatory disorders. Over the last few decades, substantial immunoregulatory effects of MSC treatment were widely observed in different experimental models of asthma. Therefore, it is tempting to speculate that stem cell-based treatment could become an attractive means to better suppress asthmatic airway inflammation, especially in subjects resistant to currently available anti-inflammatory therapies. In this review, we discuss mechanisms accounting for potent immunosuppressive properties of MSCs and the rationale for their use in asthma. We describe in detail an intriguing interplay between MSCs and other crucial players in the immune system as well as lung microenvironment. Finally, we reveal the potential of MSCs in maintaining airway epithelial integrity and alleviating lung remodeling.

An Aging-Related Single-Nucleotide Polymorphism is Associated With Altered Clinical Outcomes and Distinct Inflammatory Profiles in Aged Blunt Trauma Patients

The contribution of individual genetic determinants of aging to the adverse clinical outcomes and altered inflammation mediator networks characteristic of aged trauma patients is unknown. The AA genotype of the aging-related single-nucleotide polymorphism (SNP) rs2075650 in TOMM40 has been associated with longevity, while the AG and GG genotypes are associated with an increased risk of Alzheimer disease. Here, we studied the effect of rs2075650 on clinical outcomes and dynamic biomarker patterns after traumatic injury. Genomic DNA was obtained from blunt trauma patients admitted to the ICU and examined for 551,839 SNPs using an Illumina microarray kit. Plasma was sampled from each patient three times within the first 24 h and daily from day 1 to 7 then assayed for 31 biomarkers using Luminex. Aged patients (65-90 years) were segregated into AA (n = 77) and AG/GG (n = 17) genotypes. Additional comparisons were made with matched groups of young patients (18-30 years), controlling for injury severity score (ISS) and sex ratio, and also segregated into AA (n = 56) and AG/GG (n = 19) genotypes. Aged patients with the AA genotype had a significantly lower requirement for ventilation and fewer days on mechanical ventilation, as well as significantly higher levels of one mediator and lower levels of two mediators. Dynamic Bayesian Network inference revealed IL-23 as a central node in each network regardless of age or genotype, with MIG and IP-10 also as key mediators in the networks of the aged patients. These findings suggest that an aging-related SNP, rs2075650, may influence clinical outcomes and inflammation networks in aged patients following blunt trauma, and thus may serve as a predictive outcome biomarker in the setting of polytrauma.

Precision medicine and treatable traits in chronic airway diseases - where do we stand?

PURPOSE OF REVIEW

To provide an update on the implementation of precision medicine, based on treatable traits and mechanisms, in the daily clinical management of chronic airways diseases.

RECENT FINDINGS

Recent insights into the complex and heterogeneous nature of chronic airway diseases including chronic obstructive pulmonary disease (COPD) and asthma identified several clinical and inflammatory phenotypes. This shifted the management focus of these diseases away from the prototypic disease labels and paved the way for developing novel targeted therapies.The concept of precision medicine aims to link the right patient to the right treatment, while minimizing the risk of adverse effects. Several treatable features ('treatable traits') have now been identified for these chronic airway diseases, including pulmonary, extra-pulmonary, and psychological/lifestyle/environmental traits. As the next step, innovative detection techniques should clarify underlying mechanisms and molecular pathways of these treatable traits and novel reliable point-of-care (composite) biomarkers to help predict responders to targeted therapies must be developed.

SUMMARY

Precision medicine links the right patient to the right treatment. Identification of treatable traits in asthma and COPD will help optimize the treatment approach in these heterogeneous diseases. Furthermore, in-depth identification of underlying molecular pathways and reliable biomarkers in chronic airways diseases to guide targeted treatment in individual patients is in progress.

Treatment options in type-2 low asthma

Monoclonal antibodies targeting IgE or the type-2 cytokines interleukin (IL)-4, IL-5 and IL-13 are proving highly effective in reducing exacerbations and symptoms in people with severe allergic and eosinophilic asthma, respectively. However, these therapies are not appropriate for 30-50% of patients in severe asthma clinics who present with non-allergic, non-eosinophilic, "type-2 low" asthma. These patients constitute an important and common clinical asthma phenotype, driven by distinct, yet poorly understood pathobiological mechanisms. In this review we describe the heterogeneity and clinical characteristics of type-2 low asthma and summarise current knowledge on the underlying pathobiological mechanisms, which includes neutrophilic airway inflammation often associated with smoking, obesity and occupational exposures and may be driven by persistent bacterial infections and by activation of a recently described IL-6 pathway. We review the evidence base underlying existing treatment options for specific treatable traits that can be identified and addressed. We focus particularly on severe asthma as opposed to difficult-to-treat asthma, on emerging data on the identification of airway bacterial infection, on the increasing evidence base for the use of long-term low-dose macrolides, a critical appraisal of bronchial thermoplasty, and evidence for the use of biologics in type-2 low disease. Finally, we review ongoing research into other pathways including tumour necrosis factor, IL-17, resolvins, apolipoproteins, type I interferons, IL-6 and mast cells. We suggest that type-2 low disease frequently presents opportunities for identification and treatment of tractable clinical problems; it is currently a rapidly evolving field with potential for the development of novel targeted therapeutics.

A Low Serum CCL4/MIP-1β Level May Predict a Severe Asthmatic Responsiveness to Mepolizumab

Objective Mepolizumab, a humanized anti-interleukin-5 monoclonal antibody, is effective for treating eosinophilic severe asthma. However, there is a need for more biomarkers that can predict the patient response to mepolizumab before starting therapy. This study aimed to identify a new biomarker in the serum that is able to accurately predict the responsiveness to mepolizumab. Methods This study enrolled 11 patients who had all been diagnosed with severe eosinophilic asthma and were then administered mepolizumab every 4 weeks for at least 4 months. Blood samples were collected, and pulmonary function tests and questionnaires were administered at baseline and after 4, 8 and 16 weeks of treatment. The response to mepolizumab was then assessed based on the difference in the Asthma Quality of Life Questionnaire (AQLQ) score after 16 weeks of mepolizumab therapy compared with that at baseline. Patients with an increase in the AQLQ score of more than 0.5 were defined as responders. The cytokine levels in the blood were measured by LUMINEX 200 and ELISA. Results There were 6 responders and 5 non-responders. The responders showed a significantly lower serum level of chemokine (C-C motif) ligand 4/macrophage inflammatory protein-1β (CCL4/MIP-1β) at baseline compared to the non-responders. Receiver operating characteristic curves to distinguish responders from non-responders using the baseline serum CCL4/MIP-1β level showed a good area under the curve of 0.9. The non-responders showed a significant increase in the level of CCL4/MIP-1β after 4 weeks compared to the baseline. Conclusion A low baseline serum CCL4/MIP-1β level may be useful for predicting a good mepolizumab response in severe eosinophilic asthma.

PD-1 pathway regulates ILC2 metabolism and PD-1 agonist treatment ameliorates airway hyperreactivity

Allergic asthma is a leading chronic disease associated with airway hyperreactivity (AHR). Type-2 innate lymphoid cells (ILC2s) are a potent source of T-helper 2 (Th2) cytokines that promote AHR and lung inflammation. As the programmed cell death protein-1 (PD-1) inhibitory axis regulates a variety of immune responses, here we investigate PD-1 function in pulmonary ILC2s during IL-33-induced airway inflammation. PD-1 limits the viability of ILC2s and downregulates their effector functions. Additionally, PD-1 deficiency shifts ILC2 metabolism toward glycolysis, glutaminolysis and methionine catabolism. PD-1 thus acts as a metabolic checkpoint in ILC2s, affecting cellular activation and proliferation. As the blockade of PD-1 exacerbates AHR, we also develop a human PD-1 agonist and show that it can ameliorate AHR and suppresses lung inflammation in a humanized mouse model. Together, these results highlight the importance of PD-1 agonistic treatment in allergic asthma and underscore its therapeutic potential.

Asthma and Lung Mechanics

This article will discuss in detail the pathophysiology of asthma from the point of view of lung mechanics. In particular, we will explain how asthma is more than just airflow limitation resulting from airway narrowing but in fact involves multiple consequences of airway narrowing, including ventilation heterogeneity, airway closure, and airway hyperresponsiveness. In addition, the relationship between the airway and surrounding lung parenchyma is thought to be critically important in asthma, especially as related to the response to deep inspiration. Furthermore, dynamic changes in lung mechanics over time may yield important information about asthma stability, as well as potentially provide a window into future disease control. All of these features of mechanical properties of the lung in asthma will be explained by providing evidence from multiple investigative methods, including not only traditional pulmonary function testing but also more sophisticated techniques such as forced oscillation, multiple breath nitrogen washout, and different imaging modalities. Throughout the article, we will link the lung mechanical features of asthma to clinical manifestations of asthma symptoms, severity, and control. © 2020 American Physiological Society. Compr Physiol 10:975-1007, 2020.

Effectiveness of omalizumab in patients with severe allergic asthma with and without chronic rhinosinusitis with nasal polyps: a PROXIMA study post hoc analysis

Background

A significant proportion of patients with severe asthma may also suffer from nasal polyposis, which is commonly defined as chronic rhinosinusitis with nasal polyps (CRSwNP), the presence of which may adversely affect asthma treatment outcomes. The biologic agent omalizumab is effective as add-on therapy in patients with severe allergic asthma. The aim of this post hoc analysis of the PROXIMA study was to compare the efficacy of omalizumab between patients with severe allergic asthma, with and without comorbid CRSwNP.

Methods

PROXIMA was a prospective observational 2-part study conducted in Italy in adult patients with severe allergic asthma, where, in the second part, patients eligible for add-on omalizumab initiated treatment for 12 months. Patient baseline data such as comorbidities and history of exacerbations were collected. Outcomes were asthma control (Asthma Control Questionnaire [ACQ]), lung function (forced expiratory volume in 1 s [FEV₁]) and exacerbation rate. The post hoc analysis compared these outcomes between the cohort with comorbid CRSwNP and the cohort without CRSwNP.

Results

Of 123 patients included in this analysis, 17 (13.8%) were in the CRSwNP cohort. There was no significant difference between cohorts in baseline clinical characteristics or in change from baseline at 12 months in ACQ values,  % of predicted FEV₁ or annual asthma exacerbation rate, although results were numerically in favor of the CRSwNP cohort versus the non-CRSwNP cohort. The proportion of patients who achieved an improvement in all three outcomes was numerically greater in the CRSwNP cohort (35.7% vs 23.0%).

Conclusions

In an observational real-world setting, add-on omalizumab for severe allergic asthma was effective in improving asthma control, lung function and in reducing exacerbations, including in those patients with CRSwNP.

Immune Modulation in Asthma: Current Concepts and Future Strategies

Asthma treatment concepts have profoundly changed over the last 20 years, from standard therapeutic regimens for all patients with asthma towards individually tailored interventions targeting treatable traits ("precision medicine"). A precise and highly effective immune modulation with minimal adverse effects plays a central role in this new concept. Recently, there have been major advances in the treatment of asthma with immune-modulatory compounds. One example is the approval of several highly potent biologics for the treatment of severe asthma. New immune-modulatory strategies are expected to enter clinical practice in the future; these innovations will be especially important for patients with treatment-resistant asthma.

The enigmatic role of TIPE2 in asthma

Unlike other members of the tumor necrosis factor (TNF)-α-induced protein 8 (TNFAIP8/TIPE) family that play a carcinogenic role and regulate apoptosis, TNFAIP8-like 2 (TIPE2) can not only maintain immune homeostasis but also regulate inflammation. TIPE2 mainly restrains the activation of T cell receptor (TCR) and Toll-like receptors (TLR), regulating its downstream signaling pathways, thereby regulating inflammation. Interestingly, TIPE2 is abnormally expressed in many inflammatory diseases and may promote or inhibit inflammation in different diseases. This review summarizes the molecular target and cellular function of TIPE2 in immune cells and inflammatory diseases and the underlying mechanism by which TIPE2 regulates inflammation. The function and mechanism of TIPE2 in asthma is also explained in detail. TIPE2 is abnormally expressed in asthma and participates in the pathogenesis of different phenotypes of asthma through regulating multiple inflammatory cells' activity and function. Considering the indispensable role of TIPE2 in asthma, TIPE2 may be an effective therapeutic target in asthma. However, the available data are insufficient to provide a full understanding of the complex role of TIPE2 in human asthma. Further study is still necessary to explore the possible mechanism and functions of TIPE2 in different asthma phenotypes.

House Dust Mite Induces Bone Marrow IL-33-Responsive ILC2s and TH Cells

Type 2 innate lymphoid cells (ILC2s) and their adaptive counterpart type 2 T helper (TH2) cells respond to interleukin-33 (IL-33) by producing IL-5, which is a crucial cytokine for eosinophil development in the bone marrow. The aim of this study was to determine if bone marrow ILC2s, TH cells, and eosinophils are locally regulated by IL-33 in terms of number and activation upon exposure to the common aeroallergen house dust mite (HDM). Mice that were sensitized and challenged with HDM by intranasal exposures induced eosinophil development in the bone marrow with an initial increase of IL5Rα+ eosinophil progenitors, following elevated numbers of mature eosinophils and the induction of airway eosinophilia. Bone marrow ILC2s, TH2, and eosinophils all responded to HDM challenge by increased IL-33 receptor (ST2) expression. However, only ILC2s, but not TH cells, revealed increased ST2 expression at the onset of eosinophil development, which significantly correlated with the number of eosinophil progenitors. In summary, our findings suggest that airway allergen challenges with HDM activates IL-33-responsive ILC2s, TH cells, and eosinophils locally in the bone marrow. Targeting the IL-33/ST2 axis in allergic diseases including asthma may be beneficial by decreasing eosinophil production in the bone marrow.

Dupilumab: A Review in Moderate to Severe Asthma

Dupilumab (Dupixent^®) is a fully human monoclonal antibody against the interleukin (IL)-4 receptor α subunit of IL-4 and IL-4/IL-13 receptor complexes. IL-4 and IL-13 are key cytokines in driving type 2 inflammation, a dominant and largely eosinophilic inflammatory pathway in asthma. Trials evaluating the efficacy of dupilumab in asthma include three pivotal, placebo-controlled, phase 3 or 2b trials of 24-52 weeks' treatment duration in patients aged ≥ 12 years with moderate-to-severe asthma (inadequately controlled with medium-to-high dose inhaled corticosteroids) or severe asthma [dependent on oral corticosteroids (OCS) for control]. In these studies, adding subcutaneous dupilumab (200 or 300 mg every 2 weeks) to background therapy was generally well tolerated and reduced the rate of severe asthma exacerbations, improved lung function, as well as asthma control and, where specified, health-related quality of life (HR-QOL), and enabled OCS maintenance doses to be reduced without impacting asthma control. Dupilumab displayed efficacy across various patient subgroups, although those with heightened type 2 immune activity, including elevated eosinophils and fractional exhaled nitric oxide, tended to have a more prominent treatment benefit. Dupilumab is consequently widely indicated (and a valuable treatment option) as an add-on therapy in patients aged ≥ 12 years who have severe/moderate-to-severe asthma with a type 2 inflammation/eosinophilic phenotype despite conventional treatments or have OCS-dependent asthma.

Fractional Exhaled Nitric Oxide (FENO) in the management of asthma: a position paper of the Italian Respiratory Society (SIP/IRS) and Italian Society of Allergy, Asthma and Clinical Immunology (SIAAIC)

Asthma prevalence in Italy is on the rise and is estimated to be over 6% of the general population. The diagnosis of asthma can be challenging and elusive, especially in children and the last two decades has brought evidences that asthma is not a single disease but consists of various phenotypes. Symptoms can be underestimated by the patient or underreported to the clinician and physical signs can be scanty. Usual objective measures, like spirometry, are necessary but sometimes not significant. Despite proper treatment, asthma can be a very severe condition (even leading to death), however new drugs have recently become available which can be very effective in its control. Since asthma is currently thought to be caused by inflammation, a direct measure of the latter can be of paramount importance. For this purpose, the measurement of Fractional Exhaled Nitric Oxide (FE_NO) has been used since the early years of the current century as a non-invasive, easy-to-assess tool useful for diagnosing and managing asthma. This SIP-IRS/SIAAIC Position Paper is a narrative review which summarizes the evidence behind the usefulness of FE_NO in the diagnosis, management and phenotypization of asthma.

Hypersensitivity and adverse reactions to biologics for asthma and allergic diseases

Introduction: The development of new biologic agents has provided definite therapeutic advances but, like with any new medications, safety remains a concern.Areas covered: Using PubMed, we reviewed the literature on the adverse effects (AE) to five biologics approved for asthma and/or allergic diseases: one anti-IgE (omalizumab), three anti-IL5 (mepolizumab, reslizumab, benralizumab), and one anti-IL4 (dupilumab).Expert opinion: Biologic agents approved for asthma and allergic diseases are generally safe. Most common AE are benign and tolerated, though long-term safety is lacking for most of them. A slightly increased risk of anaphylaxis to omalizumab and reslizumab required the inclusion of a black box warning, informing the patient, the need for post-injection observation period, and the provision of epinephrine autoinjectors for self-administration when needed. Hypersensitivity reactions, mainly urticaria and very rarely serum sickness have occurred.

Sputum IL-26 Is Overexpressed in Severe Asthma and Induces Proinflammatory Cytokine Production and Th17 Cell Generation: A Case-Control Study of Women

Objective

Asthma inflammation is a complex pathway involving numerous mediators. Interleukin-26 (IL-26), a member of the IL-10 cytokine family, is abundant in human airways and induces the production of proinflammatory cytokines. Our aim was to investigate the possible role of IL-26 in severe asthma. We analysed the expression of IL-26 in severe asthma both in peripheral blood and induced sputum.

Patients and Methods

A total of 50 adult women with severe asthma were recruited and compared to 30 healthy controls (HC). Serum and sputum fluid (SF) levels of IL-26 and IL-17 were defined by ELISA. IL-26 mRNA expression and IL-26 protein were analysed using RT-PCR and Western blot. In vitro, we studied the effect of recombinant IL-26 (rIL-26) and SF-IL-26 on cultured CD4⁺ T cells and monocytes, comparing patients and controls.

Results

Concentrations of IL-26 are higher in serum and induced sputum of asthmatic patients than in HC. Moreover, IL-26 protein and mRNA expression were significantly elevated in asthma sputum cells compared to PBMCs. We observed a positive correlation between body mass index (BMI) and sputum fluid IL-26, while the correlation between IL-26 and lung function tests (FEV1% and FEV1/FVC ratio) was negative. IL-17A was highly expressed in SF and correlated positively with IL-26. In patients’ sputum IL-26 and IL-17A were significantly associated with neutrophils. Stimulation of cultured CD4⁺ T cells with monocytes by recombinant IL-26 promoted the generation of RORγt⁺ Th17⁺ cells inducing the production of IL-17A, IL-1β, IL-6 and TNF-α cytokines. IL-26 expressed in SF was biologically active and induced IL-17 secretion in the presence of IL-1β and IL-6 cytokines.

Conclusion

These findings show that IL-26 is highly produced in asthmatic sputum, induces pro-inflammatory cytokine secretion by monocytes/macrophages, and favours Th17 cell generation. IL-26 thereby appears as a novel pro-inflammatory cytokine, produced locally in the airways that may constitute a promising target to treat asthma inflammatory process.

Asthma phenotypes and T-bet protein expression in cells treated with Fluticasone Furoate/Vilanterol

Asthma is a complex disease with diverse clinical manifestations ranging from mild to severe. Despite existing guidelines for asthma recognition and treatment, still a proportion of patients stay uncontrolled. Combinational therapy which comprises inhaled corticosteroids (ICS) and a long acting B2 adrenreceptor agonist (LABA) has been suggested to control asthma. In this study T-bet expression was attested in CD4 T cells treated with Fluticasone Furoate (FF), Vilanterol (V) and FF/V combination in severe asthmatic patients compared to patients with moderate asthma and healthy controls using Immunocytochemistry (ICC). First, CD4 T cells were isolated from PBMCs of 12 patients and controls using CD4 T cell isolation kit. Subsequently, isolated CD4 T cells were cultured with FF, V and FF/V for 1 h. To accomplish ICC, cells were incubated with anti-T-bet antibody, and then stained with HRP-bound secondary antibody. T-bet expression was evaluated using light microscopy. Statistical analyses were performed using R 3.5.2 software and visualized by ggplot2 3.1.0 package. Significant increasing in T-bet expression was seen in CD4 T cells from patients with moderate asthma treated with FF and FF/V. Suggesting conclusion would be distinct mechanisms responsible for severe asthma and moderate asthma in the patients and the needs for novel therapies. Further molecular studies in different asthma phenotypes would be instructive for asthma treatment.

Biologics and Bronchial Thermoplasty for severe refractory asthma treatment: From eligibility criteria to real practice. A cross-sectional study

The increasing knowledge on immuno-inflammatory pathways allowed the development of new therapeutic options in the field of severe refractory asthma (SRA). It is therefore very important to accurately identify phenotypes and endotypes of patients potentially eligible for innovative treatments. The aim of this study was to describe a cohort of patients affected by SRA referring to the Pneumology Unit of Azienda USL di Reggio Emilia/IRCCS in Reggio Emilia, Italy. It is an observational cross-sectional study, investigating the proportion of subjects with eligibility criteria for biological treatments (omalizumab, mepolizumab, benralizumab) and non-pharmacological treatment (bronchial thermoplasty, BT). We enrolled 137 patients with SRA referring to the centre from June 1st, 2017 to June 30th, 2019. The results of this study showed that 125 (91%) of patients were eligible for at least one biologic and 94 (69%) were eligible for BT. Only 6 (4%) of patients had no criteria for any available SRA treatments. Among biologics, there were only 11 (8%) patients resulting in overlap between omalizumab, mepolizumab and benralizumab, and 22 (16%) overlap of patients when BT was included. Considering eligibility criteria for BT, only 6 (4%) patients had inclusion criteria for BT, instead in real life 28% of patients were treated with BT. The major comorbidities were: bronchiectasis, chronic rhinosinusitis with nasal polyps (CRSwNP), gastro-esophageal reflux disease (GERD), and eosinophilic granulomatosis with polyangiitis (EGPA). The prevalence of bronchiectasis was much higher in the mepolizumab (45%) and benralizumab (43%) groups than in omalizumab (1%) and BT (7%), p < 0,001; CRSwNP and GERD were equally present and EGPA was only present in the mepolizumab group. Overall, our population was eligible for biologicals in almost all cases, and a significant percentage of patients showed the presence of an overlap of allergic and eosinophilic endotypes. This implies the possibility of different therapeutic options and reiterates the need for a correct characterization of patients. This study confirmed how the identification of inflammatory endotypes and phenotypes represent a key role in the selection of the right therapy for the right patient.

Targeting NLRP3 Inflammasome Activation in Severe Asthma

Severe asthma (SA) is a chronic lung disease characterized by recurring symptoms of reversible airflow obstruction, airway hyper-responsiveness (AHR), and inflammation that is resistant to currently employed treatments. The nucleotide-binding oligomerization domain-like Receptor Family Pyrin Domain Containing 3 (NLRP3) inflammasome is an intracellular sensor that detects microbial motifs and endogenous danger signals and represents a key component of innate immune responses in the airways. Assembly of the NLRP3 inflammasome leads to caspase 1-dependent release of the pro-inflammatory cytokines IL-1β and IL-18 as well as pyroptosis. Accumulating evidence proposes that NLRP3 activation is critically involved in asthma pathogenesis. In fact, although NLRP3 facilitates the clearance of pathogens in the airways, persistent NLRP3 activation by inhaled irritants and/or innocuous environmental allergens can lead to overt pulmonary inflammation and exacerbation of asthma manifestations. Notably, administration of NLRP3 inhibitors in asthma models restrains AHR and pulmonary inflammation. Here, we provide an overview of the pathophysiology of SA, present molecular mechanisms underlying aberrant inflammatory responses in the airways, summarize recent studies pertinent to the biology and functions of NLRP3, and discuss the role of NLRP3 in the pathogenesis of asthma. Finally, we contemplate the potential of targeting NLRP3 as a novel therapeutic approach for the management of SA.