Omalizumab reduces cysteinyl leukotriene and 9α,11β-prostaglandin F2 overproduction in aspirin-exacerbated respiratory disease

Critical pathomechanisms of NSAID-exacerbated respiratory disease (N-ERD) clarified by treatment with omalizumab, an anti-IgE antibody

Characteristic symptoms of NSAID-exacerbated respiratory disease (N-ERD) include asthma, chronic eosinophilic rhinosinusitis with nasal polyposis, cysteinyl LT (CysLT) overproduction and NSAIDs hypersensitivity. Some N-ERD patients present with episodic treatment-resistant extra-respiratory symptoms (CysLT-associated coronary artery vasospasm, gastroenteritis, or skin rash). Even when using standard treatments for respiratory and extra-respiratory symptoms, including systemic corticosteroids and aspirin desensitization, it is difficult to control the clinical symptoms and severe type 2 inflammation involved with mast cells, eosinophils, ILC2s, and platelet activation. Few treatment options are applicable in a clinical setting. Therefore, identifying effective treatments is essential for managing N-ERD patients who suffer from these conditions. Our previous observational study demonstrated 12-month omalizumab treatment of N-ERD was clinically effective against respiratory symptoms. Despite the remaining eosinophilia, omalizumab significantly reduced urinary LTE4 and PGD2 metabolites to near normal levels at steady state. Based on the preliminary study, we demonstrated that omalizumab induced tolerance to aspirin in N-ERD patients 3 months after therapy initiation and suppressed activation of mast cells during 24 h of initiation in a randomized manner. Moreover, omalizumab had significant efficacy against extra-respiratory symptoms at baseline (lacking aspirin exposure) as well as throughout aspirin challenge. This review addresses the latest discoveries related to N-ERD pathogenesis and the significant effectiveness of omalizumab on N-ERD as a mast cell stabilizer. Our findings regarding omalizumab-associated mast cell inhibitory effects are indirect evidence that mast cell dysregulation and, possibly, IgE are pivotal components of N-ERD.

Brazilian guideline for the use of immunobiologicals in chronic rhinosinusitis with nasal polyps ‒ 2024 update

INTRODUCTION

Biologics targeting type 2 inflammation have revolutionized the way we treat patients with Chronic Rhinosinusitis with Nasal Polyps (CRSwNP). Particularly in severe and difficult-to-control cases, these drugs have provided a new reality for these patients, allowing for the effective and safe treatment of extensive diseases that were not completely managed with the typical strategy of surgery and topical medications.

OBJECTIVES

The experience achieved with the approval of these medications by ANVISA for use in CRSwNP and the knowledge obtained regarding outcomes, adverse effects, and the ideal patient profile prompted the update of the previously published guideline, with a detailed review of the most recent scientific literature, the personal experiences of experts, and the adaptation to the reality of the Brazilian healthcare system, both public and private.

RESULTS

We proposed a new eligibility criterion for biologics in patients with CRSwNP based on four pillars of indication: the impact of the disease on the patient's life, whether in the presence of specific symptoms or in overall quality of life; the extent of sinonasal disease; the presence of type 2 comorbidities, considering other associated diseases that may also benefit from anti-T2 biologics, and the presence of biomarkers to define type 2 inflammation, especially those associated with worse disease prognoses.

CONCLUSIONS

This innovative and pioneering method has two major advantages. First, it ensures a comprehensive evaluation of patients; second, it is flexible, as advancements in our understanding of the disease and changes in cost-effectiveness can be addressed by simply adjusting the required score for indication, without the need to modify the entire evaluation scheme.

Biologic Therapies across Nasal Polyp Subtypes

Chronic rhinosinusitis with nasal polyposis is a common inflammatory condition, with subtypes like aspirin-exacerbated respiratory disease, allergic fungal rhinosinusitis, and central compartment atopic disease sharing a common type 2 inflammatory pathway. Respiratory biologic therapies have been developed that target type 2 inflammation. In this article, we discuss the use of respiratory biologic therapies for nasal polyposis in general, as well as within the various subtypes of nasal polyps. Further, we discuss future roles of novel biologic therapies targeting type 2 inflammation in nasal polyposis.

Management of Aspirin-Exacerbated Respiratory Disease: What Does the Future Hold?

Aspirin-exacerbated respiratory disease (AERD) is a subtype of chronic rhinosinusitis with polyps (CRSwNP) and asthma with higher recurrence of nasal polyps after surgery and severe asthma. Patients with CRSwNP and asthma should be screened for AERD by detailed history of aspirin/nonsteroidal anti-inflammatory drug reactions and review of medications that may mask aspirin reaction or directly by aspirin challenge. Treatment of AERD may require more intensive therapy, including endoscopic sinus surgery, daily aspirin therapy, leukotriene modifiers, or biologics.

Hypersensitivity to intravenous succinate corticosteroids in patients with nonsteroidal anti-inflammatory drug-exacerbated respiratory disease

Although there are many case reports of asthma exacerbations with intravenous corticosteroids, especially hydrocortisone succinate, in nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD), the frequency and mechanism remain unclear. We hypothesized that N-ERD patients are potentially hypersensitive to succinates, especially succinate corticosteroids, based on the results of previous provocation studies and considered specific mechanisms. The objective of this study was to determine the frequency and mechanism of succinate corticosteroids hypersensitivity in patients with N-ERD. Eleven patients with stable, moderate to severe N-ERD were tested with hydrocortisone sodium succinate (HCs), hydrocortisone sodium phosphate (HCp), methylprednisolone sodium succinate (MPSLs), prednisolone sodium succinate (PSLs), and chloramphenicol sodium succinate (CPs, without a steroidal chemical structure) at doses below the normal dose through intravenous administration using a single-blind test. As a comparison, seven patients with aspirin-tolerant asthma (ATA) also underwent an intravenous provocation test of HCs. The positive intravenous provocation test rates of HCs 100-500 mg, HCp 500 mg, MPSLs 80 mg, PSLs 20 mg, and CPs 500 mg in N-ERD patients were 82% (9/11), 9% (1/11), 50% (5/10), 33% (1/3), and 86% (6/7), respectively. Most positive reactions began with a severe cough within 5 min of intravenous injection. The course of these hypersensitivity symptoms differed from those seen with the usual aspirin challenge test. The HCs 100-500 mg intravenous test was negative in all seven patients with ATA. In conclusion, patients with N-ERD have high rates of potential hypersensitivity to the succinate ester structure, which is not linked to the corticosteroid structure, but to the succinate ester structure. We hypothesized that the mechanism of hypersensitivity observed during rapid intravenous administration of succinate corticosteroids is mast cell activation via succinate receptor stimulation, rather than due to the corticosteroid itself.

GEMA 5.3. Spanish Guideline on the Management of Asthma

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

Aspirin-exacerbated respiratory disease: Updates in the era of biologics

OBJECTIVE

Aspirin-exacerbated respiratory disease (AERD) is a chronic respiratory condition characterized by severe chronic rhinosinusitis with nasal polyps (CRSwNP), eosinophilic asthma, and respiratory reactions to cyclooxygenase inhibitors. The management of AERD has evolved recently with the availability of respiratory biologics for treatment of severe asthma and CRSwNP. The objective of this review is to provide an update on the management of AERD in the era of respiratory biologic therapy.

DATA SOURCES

A literature review of pathogenesis and treatment of AERD, with a specific focus on biologic therapies in AERD, was performed through publications gathered from PubMed.

STUDY SELECTIONS

Original research, randomized controlled trials, retrospective studies, meta-analyses, and case series of high relevance are selected and reviewed.

RESULTS

Aspirin therapy after desensitization (ATAD) and respiratory biologic therapies targeting interleukin (IL)-4Rα, IL-5, IL-5Rα, and immunoglobulin E, all have some efficacy in the treatment of CRSwNP and asthma in patients with AERD. There are currently no head-to-head studies comparing ATAD vs respiratory biologic therapy, or specific respiratory biologics, for asthma and CRSwNP in patients with AERD.

CONCLUSION

Advances in our understanding of the fundamental drivers of the chronic respiratory inflammation in asthma and CRSwNP have led to the identification of several potential therapeutic targets for these diseases that can be used in patients with AERD. Further study of the use of ATAD and biologic therapy, independently and together, will help to inform future treatment algorithms for patients with AERD.

Omalizumab ameliorates extrarespiratory symptoms in patients with aspirin-exacerbated respiratory disease

BACKGROUND

Omalizumab, an anti-IgE antibody, has clinical efficacy against respiratory symptoms of aspirin-exacerbated respiratory disease (AERD). However, some patients with AERD also present with extrarespiratory (chest, gastrointestinal, and/or cutaneous) symptoms, which are resistant to conventional treatment but can be alleviated by systemic corticosteroids.

OBJECTIVE

We evaluated the efficacy of omalizumab on extrarespiratory symptoms related to AERD.

METHODS

In study 1, a total of 27 consecutive patients with AERD initially prescribed omalizumab at Sagamihara National Hospital between July 2009 and March 2019 were retrospectively studied. Frequency of exacerbations of AERD-related extrarespiratory symptoms was compared before and after omalizumab treatment. In study 2, we reported 3 AERD cases with aspirin challenge-induced extrarespiratory symptoms among patients studied in our previous randomized trial (registration UMIN000018777), which evaluated the effects of omalizumab on hypersensitivity reactions during aspirin challenge to AERD patients. Extrarespiratory symptoms induced during the aspirin challenge were compared between placebo and omalizumab phases.

RESULTS

In study 1, omalizumab treatment was associated with decrease in frequency of exacerbation of chest pain (no. [%] of patients with exacerbation frequency ≥1 time per year, 6 [22.2%] vs 0; P < .001), gastrointestinal symptoms (9 [33.3%] vs 2 [7.4%]; P = .016), and cutaneous symptoms (16 [59.3%] vs 2 [7.4%]; P < .001), even under conditions of treatment-related reduction in systemic corticosteroid dose. Omalizumab also attenuated all the extrarespiratory symptoms during aspirin challenge in study 2.

CONCLUSION

Omalizumab ameliorated extrarespiratory symptoms at baseline (without aspirin exposure) and during aspirin challenge.

Distribution, composition, and activity of airway-associated adipose tissue in the porcine lung

Patients with comorbid asthma-obesity experience greater disease severity and are less responsive to therapy. We have previously reported adipose tissue within the airway wall that positively correlated with body mass index. Accumulation of biologically active adipose tissue may result in the local release of adipokines and disrupt large and small airway function depending on its anatomical distribution. This study therefore characterized airway-associated adipose tissue distribution, lipid composition, and adipokine activity in a porcine model. Airway segments were systematically dissected from different locations of the bronchial tree in inflation-fixed lungs. Cryosections were stained with hematoxylin and eosin (H&E) for airway morphology, oil red O to distinguish adipose tissue, and Nile blue A for lipid subtype delineation. Excised airway-associated adipose tissue was cultured for 72 h to quantify adipokine release using immunoassays. Results showed that airway-associated adipose tissue extended throughout the bronchial tree and occupied an area proportionally similar to airway smooth muscle within the wall area. Lipid composition consisted of pure neutral lipids (61.7 ± 3.5%), a mixture of neutral and acidic lipids (36.3 ± 3.4%), or pure acidic lipids (2.0 ± 0.8%). Following tissue culture, there was rapid release of IFN-γ, IL-1β, and TNF-α at 12 h. Maximum IL-4 and IL-10 release was at 24 and 48 h, and peak leptin release occurred between 48 and 72 h. These data extend previous findings and demonstrate that airway-associated adipose tissue is prevalent and biologically active within the bronchial tree, providing a local source of adipokines that may be a contributing factor in airway disease.

Updates on immune mechanisms in aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease has fascinated and frustrated specialists in allergy/immunology, pulmonology, and otorhinolaryngology for decades. It generally develops in previously healthy young adults and is unremitting and challenging to treat. The classical triad of asthma, nasal polyposis, and pathognomonic respiratory reactions to aspirin and other cyclooxygenase-1 inhibitors is accompanied by high levels of mast cell activation, cysteinyl leukotriene production, platelet activation, and severe type 2 respiratory inflammation. The "unbraking" of mast cell activation and further cysteinyl leukotriene generation induced by cyclooxygenase-1 inhibition reflect an idiosyncratic dependency on cyclooxygenase-1-derived products, likely prostaglandin E2, to maintain a tenuous homeostasis. Although cysteinyl leukotrienes are clear disease effectors, little else was known about their cellular sources and targets, and the contributions from other mediators and type 2 respiratory inflammation effector cells to disease pathophysiology were unknown until recently. The applications of targeted biological therapies, single-cell genomics, and transgenic animal approaches have substantially advanced our understanding of aspirin-exacerbated respiratory disease pathogenesis and treatment and have also revealed disease heterogeneity. This review covers novel insights into the immunopathogenesis of aspirin-exacerbated respiratory disease from each of these lines of research, including the roles of lipid mediators, effector cell populations, and inflammatory cytokines, discusses unanswered questions regarding cause and pathogenesis, and considers potential future therapeutic options.

The Role of Omalizumab in NSAID-Exacerbated Respiratory Disease: A Narrative Review

Nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD) is a condition characterized by the triad of chronic rhinosinusitis with nasal polyps, bronchial asthma, and hypersensitivity to nonsteroidal anti-inflammatory drugs. This article explores the current knowledge on the various pathological mechanism(s) of N-ERD-such as arachidonic acid metabolism, cysteinyl leukotrienes, prostaglandins, platelets, IgE, mast cells, eosinophils, basophils, and innate immune system-and the role of omalizumab in its management. The authors dive deep into the role of IgE in N-ERD and its potential as a therapeutic target. IgE plays a significant role in mediating allergic reactions, is intricately linked with mast cells, interacts with multiple immunopathological pathways involved in N-ERD, and tends to be elevated in patients with N-ERD. Multiple real-world studies, observational studies, and case series, as well as 2 phase III trials, have demonstrated the effectiveness of omalizumab in the management of N-ERD. For a disease with such a well-documented history, the pathophysiology of N-ERD and the most effective ways to manage it remain a mystery. With this background, the authors ask-is IgE a missing piece of the N-ERD puzzle, thus explaining the efficacy of omalizumab in the treatment of the disease?

Rapid and sustained effect of dupilumab on clinical and mechanistic outcomes in aspirin-exacerbated respiratory disease

BACKGROUND

Dupilumab, a mAb targeting IL-4Rα, improves upper and lower airway symptoms in patients with aspirin-exacerbated respiratory disease (AERD), but the mechanisms leading to clinical improvement are not fully elucidated.

OBJECTIVE

Our aim was to identify the mechanistic basis of clinical improvement in patients with AERD treated with dupilumab.

METHODS

A total of 22 patients with AERD were treated with dupilumab for 3 months for severe asthma and/or chronic rhinosinusitis with nasal polyps. Clinical outcomes were assessed at baseline and at 1 and 3 months after initiation of dupilumab. Nasal fluid, urine, blood, and inferior turbinate scrapings were collected at the 3 time points for determination of mediator levels, cellular assays, and RNA sequencing.

RESULTS

Participants had rapid improvement in clinical measures, including sense of smell, sinonasal symptoms, and lung function after 1 month of treatment with dupilumab; the improvements were sustained after 3 months of dupilumab. Baseline severity of smell loss was correlated with lower nasal prostaglandin E₂ levels. Dupilumab increased nasal prostaglandin E₂ level and decreased levels of nasal albumin, nasal and urinary leukotriene E₄, and serum and nasal IgE. Transcripts related to epithelial dysfunction and leukocyte activation and migration were downregulated in inferior turbinate tissue after treatment with dupilumab. There were no dupilumab-induced changes in nasal eosinophilia.

CONCLUSION

Inhibition of IL-4Rα in AERD led to rapid improvement in respiratory symptoms and smell, with a concomitant improvement in epithelial barrier function, a decrease in inflammatory eicosanoid levels, and an increase in the anti-inflammatory eicosanoid prostaglandin E₂ level. The therapeutic effects of dupilumab are likely due to decreased IL-4Rα signaling on respiratory tissue granulocytes, epithelial cells, and B cells.

Baseline Conservative and Surgical Management in the Treatment of NSAID-Exacerbated Respiratory Disease

Non-steroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) is a chronic medical condition that includes asthma, chronic rhinosinusitis with nasal polyposis, and hypersensitivity to aspirin and other NSAIDs. Eosinophilic inflammation in the upper and lower airways is treated with local corticosteroids, repeated antibiotics, oral corticosteroid courses, endoscopic sinus surgery, and in some cases aspirin treatment after desensitization (ATAD). Nevertheless, the disease may be uncontrolled and it has a great impact on quality of life. A better understanding of the pathomechanisms of the disease and the development of medications that target type 2 inflammation mediators may have a crucial role in achieving better disease control in patients with N-ERD.

Local and Systemic Production of Pro-Inflammatory Eicosanoids Is Inversely Related to Sensitization to Aeroallergens in Patients with Aspirin-Exacerbated Respiratory Disease

Aspirin-exacerbated respiratory disease (AERD) is characterized by overproduction of the pro-inflammatory eicosanoids. Although immunoglobulin E-mediated sensitization to aeroallergens is common among AERD patients, it does not belong to the defining disease characteristics. In this study of 133 AERD patients, we sought to find a relationship between sensitization to aeroallergens and local (leukotriene E4, prostaglandin E2 and prostaglandin D2) and/or systemic (leukotriene E4) production of arachidonic acid metabolites. Interestingly, a negative association between pro-inflammatory eicosanoid levels in induced sputum supernatant or urine and sensitization to aeroallergens was observed. This inverse relationship might suggest the presence of a protective effect of atopic sensitization to aeroallergens against stronger local airway inflammation and higher systemic AERD-related inflammatory activity.

Emerging Biomarkers Beyond Leukotrienes for the Management of Nonsteroidal Anti-inflammatory Drug (NSAID)-Exacerbated Respiratory Disease

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD) is a unique condition characterized by aspirin/NSAID hypersensitivity, adult-onset asthma, and/or chronic rhinosinusitis with nasal polyps. Arachidonic acid metabolism dysregulation and intense eosinophilic/type 2 inflammation are central mechanisms in NERD. Studies have been conducted on various biomarkers, and urinary leukotriene E4 is considered the most available biomarker of NERD. However, the pathophysiology of NERD is heterogeneous and complex. Epithelial cells and platelets can interact with immune cells in NERD, and novel biomarkers related to these interactions have recently been investigated. We summarize emerging novel biomarkers of NERD and discuss their roles in the management of NERD.

Omalizumab-induced aspirin tolerance in N-ERD patients is independent of atopic sensitization

BACKGROUND

NSAID-exacerbated respiratory disease (N-ERD) comprises the triad of chronic rhinosinusitis with nasal polyps (CRSwNP), asthma and intolerance to inhibitors of the cyclooxygenase-1-enzyme. The impact of omalizumab on prevention of aspirin-induced hypersensitivity in N-ERD patients with and without atopic sensitization has not been thoroughly addressed.

OBJECTIVE

To investigate the effect of omalizumab treatment on aspirin tolerance in atopic and non-atopic N-ERD patients.

METHODS

This single-center, prospective trial evaluated overall omalizumab-induced aspirin tolerability in N-ERD patients by performing aspirin challenge testing before and after 6 months of anti-IgE therapy. The impact of omalizumab on CRSwNP, asthma as well as serum and tissue biomarkers in patients with and without comorbid atopic sensitizations was further analyzed.

RESULTS

Out of 33 patients included in the study, 56% developed complete aspirin tolerance and 18% tolerated higher dosages after 24 weeks. Polyp size and disease-specific symptoms (NPS:-1.9±0.3,p<0.001;SNOT-20:-16.7±3.7,p<0.001;ACT:+3.2±0.7,p<0.001) improved in all patients irrespective of atopic sensitization. Effectiveness of omalizumab was accompanied by an increase in mean total serum IgE (307.8±42kU/L,p<0.001) and a decrease in ECP (-10.6±6.7 μg/L ) and in relative eosinophilia (-2.5±0.7%, p<0.01). While there was a significant reduction of tissue IgE (p<0.05) in all patients after 4 weeks, the number of local eosinophils decreased only in atopic individuals (p<0.05).

CONCLUSION

Omalizumab induced complete aspirin tolerance in the majority (56%) of patients independent of atopic sensitization and demonstrated clinical efficacy in the treatment of CRSwNP and asthma. Inhibition of IgE can therefore be a promising treatment option in preventing NSAID hypersensitivity reactions in N-ERD patients.

Recent Insights into the Management of Inflammation in Asthma

The present prevailing inflammatory paradigm in asthma is of T2-high inflammation orchestrated by key inflammatory cells like Type 2 helper lymphocytes, innate lymphoid cells group 2 and associated cytokines. Eosinophils are key components of this T2 inflammatory pathway and have become key therapeutic targets. Real-world evidence on the predominant T2-high nature of severe asthma is emerging. Various inflammatory biomarkers have been adopted in clinical practice to aid asthma characterization including airway measures such as bronchoscopic biopsy and lavage, induced sputum analysis, and fractional exhaled nitric oxide. Blood measures like eosinophil counts have also gained widespread usage and multicomponent algorithms combining different parameters are now appearing. There is also growing interest in potential future biomarkers including exhaled volatile organic compounds, micro RNAs and urinary biomarkers. Additionally, there is a growing realisation that asthma is a heterogeneous state with numerous phenotypes and associated treatable traits. These may show particular inflammatory patterns and merit-specific management approaches that could improve asthma patient outcomes. Inhaled corticosteroids (ICS) remain the mainstay of asthma management but their use earlier in the course of disease is being advocated. Recent evidence suggests potential roles for ICS in combination with long-acting beta-agonists (LABA) for as needed use in mild asthma whilst maintenance and reliever therapy regimes have gained widespread acceptance. Other anti-inflammatory strategies including ultra-fine particle ICS, leukotriene receptor antagonists and macrolide antibiotics may show efficacy in particular phenotypes too. Monoclonal antibody biologic therapies have recently entered clinical practice with significant impacts on asthma outcomes. Understanding of the efficacy and use of those agents is becoming clearer with a growing body of real-world evidence as is their potential applicability to other treatable comorbid traits. In conclusion, the evolving understanding of T2 driven inflammation alongside a treatable traits disease model is enhancing therapeutic approaches to address inflammation in asthma.

Innate immune cell dysregulation drives inflammation and disease in aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease (AERD) is a complex inflammatory disorder that is not generally viewed as a disease involving the adaptive immune system but instead one largely driven by the innate immune system. This article focuses on the cellular dysregulation involving 4 central cell types: eosinophils, basophils, mast cells, and innate lymphoid type 2 cells. AERD can be envisioned as involving a self-perpetuating vicious circle in which mediators produced by a differentiated activated epithelial layer, such as IL-25, IL-33, and thymic stromal lymphopoietin, engage and activate each of these innate immune cells. The activation of these innate immune cells with their production of additional cytokine/chemokine and lipid mediators leads to further recruitment and activation of these innate immune cells. More importantly, numerous mediators produced by these innate immune cells provoke the epithelium to induce further inflammation. This self-perpetuating cycle of inflammation partially explains both current interventions suggested to ameliorate AERD (eg, aspirin desensitization, leukotriene modifiers, anti-IL-5/IL-5 receptor, anti-IL-4 receptor, and anti-IgE) and invites exploration of novel targets as specific therapies for this condition (prostaglandin D₂ antagonists or cytokine antagonists [IL-25, IL-33, thymic stromal lymphopoietin]). Several of these interventions currently show promise in small retrospective analyses but now require definite clinical trials.

What is the contribution of IgE to nasal polyposis?

Taking a novel approach, this narrative review collates knowledge about nasal polyposis and the biological functions of IgE in several diseases (allergic rhinitis, allergic asthma, nonsteroidal anti-inflammatory drugs-exacerbated respiratory disease, and chronic spontaneous urticaria) to consider which IgE-mediated mechanisms are relevant to nasal polyposis pathology. A type 2 eosinophil-dominated inflammatory signature is typical in nasal polyp tissue of European patients with nasal polyposis, with a shift toward this endotype observed in Asian populations in recent years. Elevated polyclonal IgE is present in the nasal tissue of patients with and without allergy. It is derived from many different B-cell clones and, importantly, is functional (proinflammatory). Staphylococcus aureus enterotoxins are thought to act as superantigens, inducing production of polyclonal IgE via B-cell and T-cell activation, and triggering release of inflammatory mediators. In some patients, exposure to antigens/triggers leads to production of high levels of antigen-specific IgE, which mediates cross-linking of the high-affinity IgE receptor on various cells, causing release of inflammatory mediators. The efficacy of omalizumab confirms IgE as an important inflammatory mediator in nasal polyposis. By blocking IgE, omalizumab targets the T2 inflammation in nasal polyposis, reduces nasal polyp score and improves symptoms.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Effectiveness of endoscopic sinus surgery and aspirin therapy in the management of aspirin-exacerbated respiratory disease

Background: Aspirin therapy and/or type 2 (T2) biologics are used in the management of aspirin-exacerbated respiratory disease (AERD). Objective: To identify the number of patients with AERD who tolerated aspirin therapy, yet due to persistent symptoms, incorporated T2 biologic management. Methods: A retrospective review was performed between July 2016 and June 2019. Patients with AERD and who underwent endoscopic sinus surgery (ESS), aspirin desensitization (AD), and at least 6 months of aspirin therapy (ATAD) after AD, and who remained biologic-naive up through this timepoint were included in the study. Introduction of a T2 biologic while on ATAD was the primary outcome. The secondary outcome was a change in a validated patient-reported outcome measure for chronic rhinosinusitis score between the postoperative predesensitization timepoint, and the 6-month postdesensitization timepoint, presented as means and compared by using the Student's t-test. Results: A total of 103 patients met inclusion criteria. Two patients (1.9%) ultimately supplemented ATAD with a T2 biologic. The mean outcomes measure test score after 6 months of ATAD for patients who received biologics was 40.5 versus 15 in those who did not receive biologics (p = 0.02). The mean differences between the postoperative predesensitization test score and the 6-month postdesensitization test score for patients who went on to receive biologics was an increase of 13 versus a decrease of 10 for those patients who did not receive biologics (p = 0.12). Conclusion: ESS, coupled with AD and ATAD, was successful in the long-term management of the majority of the patients with AERD, which rarely required the incorporation of T2 biologics. Patient questionnaires, such as outcomes measure test score, may identify aspirin therapy failures and help guide the practitioner in deciding when to introduce T2 biologics into the patient's treatment regimen.

Aspirin exacerbated respiratory disease (AERD): molecular and cellular diagnostic & prognostic approaches

Aspirin-exacerbated respiratory disease (AERD) is characterized by immune cells dysfunction. This study aimed to investigate the molecular mechanisms involved in AERD pathogenesis. Relevant literatures were identified by a PubMed search (2005-2019) of english language papers using the terms "Aspirin-exacerbated respiratory disease", "Allergic inflammation", "molecular mechanism" and "mutation". According to the significant role of inflammation in AERD development, ILC-2 is known as the most important cell in disease progression. ILC-2 produces cytokines that induce allergic reactions and also cause lipid mediators production, which activates mast cells and basophils, ultimately. Finally, Monoclonal antibody and Aspirin desensitization in patients can be a useful treatment strategy for prevention and treatment.

Choice of biologics in asthma endotypes

PURPOSE OF REVIEW

The aim of this study was to highlight the phenotypes and endotypes of asthma as a tool for selection of the Food and Drug Administration approved biologic therapies.

RECENT FINDINGS

An evolving concept of asthma has led to the identification of distinct phenotypes and endotypes in this disease. Asthma endotypes are defined as the biological mechanism and are often categorized as T2-high and T2-low based on the influence of T helper type 2 (T2) cells and type 2 cytokines, including interleukin (IL)-4, IL-5, IL-9 and IL-13. Biomarkers such as peripheral blood absolute eosinophil count, total IgE, specific IgE and fractional exhaled nitric oxide may be used as indicators of asthma endotypes and help predict response to biologic therapies. There are currently five biologic therapies approved as a treatment option for T2-high asthma: omalizumab, benralizumab, mepolizumab, reslizumab and dupilumab.

SUMMARY

Here, we explore the current understandings of asthma endotypes and review their associated phenotypes. We provide practical and evidence-based guidance for clinicians considering a biologic for asthma add-on maintenance therapy.

Urinary Leukotriene E4 and Prostaglandin D2 Metabolites Increase in Adult and Childhood Severe Asthma Characterized by Type 2 Inflammation. A Clinical Observational Study

Rationale: New approaches are needed to guide personalized treatment of asthma.Objectives: To test if urinary eicosanoid metabolites can direct asthma phenotyping.Methods: Urinary metabolites of prostaglandins (PGs), cysteinyl leukotrienes (CysLTs), and isoprostanes were quantified in the U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Diseases Outcomes) study including 86 adults with mild-to-moderate asthma (MMA), 411 with severe asthma (SA), and 100 healthy control participants. Validation was performed internally in 302 participants with SA followed up after 12-18 months and externally in 95 adolescents with asthma.Measurement and Main Results: Metabolite concentrations in healthy control participants were unrelated to age, body mass index, and sex, except for the PGE₂ pathway. Eicosanoid concentrations were generally greater in participants with MMA relative to healthy control participants, with further elevations in participants with SA. However, PGE₂ metabolite concentrations were either the same or lower in male nonsmokers with asthma than in healthy control participants. Metabolite concentrations were unchanged in those with asthma who adhered to oral corticosteroid treatment as documented by urinary prednisolone detection, whereas those with SA treated with omalizumab had lower concentrations of LTE₄ and the PGD₂ metabolite 2,3-dinor-11β-PGF_2α. High concentrations of LTE₄ and PGD₂ metabolites were associated with lower lung function and increased amounts of exhaled nitric oxide and eosinophil markers in blood, sputum, and urine in U-BIOPRED participants and in adolescents with asthma. These type 2 (T2) asthma associations were reproduced in the follow-up visit of the U-BIOPRED study and were found to be as sensitive to detect T2 inflammation as the established biomarkers.Conclusions: Monitoring of urinary eicosanoids can identify T2 asthma and introduces a new noninvasive approach for molecular phenotyping of adult and adolescent asthma.Clinical trial registered with www.clinicaltrials.gov (NCT01976767).

The role of aspirin desensitization followed by oral aspirin therapy in managing patients with aspirin-exacerbated respiratory disease: A Work Group Report from the Rhinitis, Rhinosinusitis and Ocular Allergy Committee of the American Academy of Allergy, Asthma & Immunology

Aspirin-exacerbated respiratory disease (AERD) is characterized by the clinical triad of chronic rhinosinusitis with nasal polyps, asthma, and an intolerance to medications that inhibit the cycloxgenase-1 enzyme. Patients with AERD on average have more severe respiratory disease compared with patients with chronic rhinosinusitis with nasal polyps and/or asthma alone. Although patients with AERD traditionally develop significant upper and lower respiratory tract symptoms on ingestion of cycloxgenase-1 inhibitors, most of these same patients report clinical benefit when desensitized to aspirin and maintained on daily aspirin therapy. This Work Group Report provides a comprehensive review of aspirin challenges, aspirin desensitizations, and maintenance aspirin therapy in patients with AERD. Identification of appropriate candidates, indications and contraindications, medical and surgical optimization strategies, protocols, medical management during the desensitization, and recommendations for maintenance aspirin therapy following desensitization are reviewed. Also included is a summary of studies evaluating the clinical efficacy of aspirin therapy after desensitization as well as a discussion on the possible cellular and molecular mechanisms explaining how this therapy provides unique benefit to patients with AERD.

Olfactory outcomes in the management of aspirin exacerbated respiratory disease related chronic rhinosinusitis

Patients with aspirin exacerbated respiratory disease (AERD) experience a severe and recalcitrant form of chronic rhinosinusitis with nasal polyposis (CRSwNP) and asthma, which are exacerbated by aspirin/NSAID ingestion. As compared with aspirin-tolerant CRSwNP, patients with AERD experience more severe olfactory dysfunction, which is one of the key contributors to the observed decrease in quality of life (QOL) in this disease. The objective of this paper is to review the published olfactory outcomes observed with various treatment modalities.

Effects of Omalizumab Treatment in Patients With Recalcitrant Nasal Polyposis and Mild Asthma: A Multicenter Retrospective Study

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a clinical entity with specific features that impacts significantly on patient quality of life (QoL). CRSwNP is often associated with asthma and is difficult to control and manage despite pharmacological and/or surgical treatment. Omalizumab, a monoclonal anti-IgE antibody, has emerged as a putative therapeutic option.

OBJECTIVE

To evaluate the effects of omalizumab on nasal polyp (NP) size and QoL assessed by Sino-Nasal Outcome Test-22 (SNOT-22) in patients with recalcitrant CRSwNP and mild asthma.

METHODS

A multicenter retrospective analysis of patient data from the Community of Valencia (Spain) was performed. Adult patients with recalcitrant CRSwNP and comorbid mild asthma receiving compassionate use of omalizumab were included. NP size measured by total nasal endoscopic polyp score (TPS) and QoL evaluated through the SNOT-22 questionnaire were assessed at baseline and monthly over 12 months. An ordinal regression model was built to analyze the results.

RESULTS

A total of 23 CRSwNP patients with a mean age (± SD) of 54.78 ± 9.46 years were included. Nineteen suffered from aspirin-exacerbated respiratory disease (AERD). In all patients, a significant and sustained reduction in TPS was observed over time, accompanied by improvements in QoL reflected in lower SNOT-22 scores. In the ordinal regression model, time but not total IgE, age or tissue eosinophilia impacted on NP size and SNOT-22 outcomes. Additionally, improvements in QoL were not explained by reductions in the size of polyps.

CONCLUSION

Omalizumab was effective for the treatment of patients with recalcitrant CRSwNP and mild asthma, even when AERD was present, by reducing NP size and improving QoL; treatment time was a key factor. SNOT-22 improvements were not explained by decreases in TPS, indicating that omalizumab may be effective in all patients, regardless of polyp size.

Targeted Molecular Therapies in Allergy and Rhinology

Biologic agents, monoclonal antibodies that target highly-specific molecular pathways of inflammation, are becoming integrated into care pathways for multiple disorders that are relevant in otolaryngology and allergy. These conditions share common inflammatory mechanisms of so-called Type 2 inflammation with dysregulation of immunoglobulin E production and eosinophil and mast cell degranulation leading to tissue damage. Biologic agents are now available for the treatment of chronic rhinosinusitis with nasal polyps (CRSwNP), asthma, eosinophilic granulomatosis with polyangiitis (EGPA), atopic dermatitis (AD), and chronic spontaneous urticaria (CSU). This paper summarizes the diagnosis and management of these conditions and critically reviews the clinical trial data that has led to regulatory approval of biologic agents for these conditions.

Aspirin-exacerbated respiratory disease: Update on medical management

Aspirin-exacerbated respiratory disease (AERD) is frequently diagnosed in patients with severe type 2 airway inflammation presenting with nasal polyps and severe asthma. It has been associated with a recalcitrant course with high medical and surgical requirements. The advent of recent biological and other targeted treatments show promise in the medical management of patient with AERD. The goal of complete disease control where patients no longer require recurrent surgical procedures, systemic corticosteroid exposure and may live with a stable and relatively normal quality of life is now within reach. Further work is necessary to identify biomarkers predictive of treatment response.

Local immunoglobulin production in nasal tissues: A key to pathogenesis in chronic rhinosinusitis with nasal polyps and aspirin-exacerbated respiratory disease

OBJECTIVE

Local activation of B cells and antibody production are important for protective and pathogenic immune responses. Furthermore, there is evidence that local activation of B cells and antibody production are important for pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) and a severe subset of CRSwNP, aspirin-exacerbated respiratory disease (AERD). This review summarizes these findings and the potential role of B cells and antibodies in disease pathogenesis.

DATA SOURCES

Published literature from PubMed searches.

STUDY SELECTIONS

Studies relevant to B cell development and the roles of B cells and antibodies in the pathogenesis of CRSwNP and AERD.

RESULTS

Formation of tertiary lymphoid structures plays a key role in the local activation of B cells and antibody production. This process is important for fighting infections, but it also contributes to autoimmune disease. Furthermore, there is evidence to support a role for local B cell activation and antibody production in a variety of allergic diseases. Nasal polyp tissues from patients with CRSwNP and AERD have elevated levels of activated B cell subsets and locally produced antibodies. These locally produced antibodies may contribute to disease pathogenesis in a variety of ways, including activation of innate effector cells, whereas locally activated B cells may contribute to pathogenesis through the activation of T cells.

CONCLUSION

More studies are needed to determine the role of B cells and antibodies in driving disease in these patients. However, targeting the processes that drive local B cell activation and antibody production may provide new therapeutic approaches and could help to reduce chronic inflammation.

Japanese guidelines for adult asthma 2020

Bronchial asthma is characterized by chronic airway inflammation, which manifests clinically as variable airway narrowing (wheezes and dyspnea) and cough. Long-standing asthma may induce airway remodeling and become intractable. The prevalence of asthma has increased; however, the number of patients who die from it has decreased (1.3 per 100,000 patients in 2018). The goal of asthma treatment is to control symptoms and prevent future risks. A good partnership between physicians and patients is indispensable for effective treatment. Long-term management with therapeutic agents and the elimination of the triggers and risk factors of asthma are fundamental to its treatment. Asthma is managed by four steps of pharmacotherapy, ranging from mild to intensive treatments, depending on the severity of disease; each step includes an appropriate daily dose of an inhaled corticosteroid, which may vary from low to high. Long-acting β₂-agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonists are recommended as add-on drugs, while anti-immunoglobulin E antibodies and other biologics, and oral steroids are reserved for very severe and persistent asthma related to allergic reactions. Bronchial thermoplasty has recently been developed for severe, persistent asthma, but its long-term efficacy is not known. Inhaled β₂-agonists, aminophylline, corticosteroids, adrenaline, oxygen therapy, and other approaches are used as needed during acute exacerbations, by selecting treatment steps for asthma based on the severity of the exacerbations. Allergic rhinitis, eosinophilic chronic rhinosinusitis, eosinophilic otitis, chronic obstructive pulmonary disease, aspirin-exacerbated respiratory disease, and pregnancy are also important conditions to be considered in asthma therapy.

Omalizumab for Aspirin Hypersensitivity and Leukotriene Overproduction in Aspirin-exacerbated Respiratory Disease. A Randomized Controlled Trial

Rationale: Aspirin-exacerbated respiratory disease is characterized by severe asthma, nonsteroidal antiinflammatory drug hypersensitivity, nasal polyposis, and leukotriene overproduction. Systemic corticosteroid therapy does not completely suppress lifelong aspirin hypersensitivity. Omalizumab efficacy against aspirin-exacerbated respiratory disease has not been investigated in a randomized manner.

Objectives: To evaluate omalizumab efficacy against aspirin hypersensitivity, leukotriene E₄ overproduction, and symptoms during an oral aspirin challenge in patients with aspirin-exacerbated respiratory disease using a randomized design.

Methods: We performed a double-blind, randomized, crossover, placebo-controlled, single-center study at Sagamihara National Hospital between August 2015 and December 2016. Atopic patients (20–79 yr old) with aspirin-exacerbated respiratory disease diagnosed by systemic aspirin challenge were randomized (1:1) to a 3-month treatment with omalizumab or placebo, followed by a >18-week washout period (crossover design). The primary endpoint was the difference in area under logarithm level of urinary leukotriene E₄ concentration versus time curve in the intent-to-treat population during an oral aspirin challenge.

Measurements and Main Results: Sixteen patients completed the study and were included in the analysis. The area under the logarithm level of urinary leukotriene E₄ concentration versus time curve during an oral aspirin challenge was significantly lower in the omalizumab phase (median [interquartile range], 51.1 [44.5–59.8]) than in the placebo phase (80.8 [interquartile range, 65.4–87.8]) (P < 0.001). Ten of 16 patients (62.5%) developed oral aspirin tolerance up to cumulative doses of 930 mg in the omalizumab phase (P < 0.001).

Conclusions: Omalizumab treatment inhibited urinary leukotriene E₄ overproduction and upper/lower respiratory tract symptoms during an oral aspirin challenge, resulting in aspirin tolerance in 62.5% of the patients with aspirin-exacerbated respiratory disease.

Efficacy of benralizumab for patients with severe eosinophilic asthma: a retrospective, real-life study

Background

Benralizumab, an anti-interleukin-5 (IL-5) receptor α monoclonal antibody, significantly reduces the number of annual exacerbations and oral corticosteroid (OCS) maintenance doses for patients with severe eosinophilic asthma (SEA). However, few studies on the efficacy of this biologic in real life are available. The aim was to elucidate the efficacy of benralizumab by evaluating changes in clinical parameters after benralizumab treatment in patients with SEA.

Methods

From July 2018 to December 2019, 24 Japanese patients with SEA received benralizumab at Jikei University Hospital. We retrospectively evaluated the patients’ characteristics, parameters, numbers of exacerbations and maintenance OCS doses.

Results

Among the 24 patients, eleven patients had received mepolizumab treatment and were directly switched to benralizumab. The peripheral blood eosinophil and basophil counts significantly decreased after benralizumab treatment regardless of previous mepolizumab treatment. Pulmonary function, Asthma Control Test scores, the numbers of annual exacerbations and maintenance OCS doses in patients without previous mepolizumab treatment tended to improve without significant differences. Fourteen patients (58%) were responders according to the Global Evaluation of Treatment Effectiveness (GETE) score. The proportion of GETE responders among patients with aspirin-exacerbated respiratory disease (AERD) tended to be lower than that among patients without AERD (p = 0.085). After benralizumab treatment, the change in the forced expiratory volume in 1 s from baseline was 200 ml or greater in eight patients (33%), including three patients who were switched from mepolizumab.

Conclusion

Benralizumab treatment improved and controlled asthma symptoms based on the GETE score.

NSAID-Exacerbated Respiratory Disease (NERD): From Pathogenesis to Improved Care

Nonsteroidal antiinflammatory drug (NSAID)-exacerbated respiratory disease (NERD) is characterized by moderate-to-severe asthma and a higher prevalence of chronic rhinosinusitis/nasal polyps, but is a highly heterogeneous disorder with various clinical manifestations. Two major pathogenic mechanisms are: (1) overproduction of cysteinyl leukotrienes with dysregulation of arachidonic acid metabolism and (2) increased type 2 eosinophilic inflammation affected by genetic mechanisms. Aspirin challenge is the gold standard to diagnose NERD, whereas reliable in vitro biomarkers have yet not been identified. Therapeutic approaches have been done on the basis of disease severity with the avoidance of culprit and cross-reacting NSAIDs, and when indicated, aspirin desensitization is an effective treatment option. Biologic approaches targeting Type 2 cytokines are emerging as potential therapeutic options. Here, we summarize the up-to-date evidence of pathophysiologic mechanisms and diagnosis/management approaches to the patients with NERD with its phenotypic classification.

New phenotypes in hypersensitivity reactions to nonsteroidal anti-inflammatory drugs

PURPOSE OF REVIEW

Nonsteroidal anti-inflammatory drug (NSAID) is one of the most frequently prescribed medications in the medical field, and hypersensitivity to NSAID is a common adverse drug reaction encountered. However, NSAID hypersensitivity presents a variety of symptoms caused by diverse pharmacological and immunological mechanisms.

RECENT FINDINGS

Owing to the heterogeneity of the disease, a new concept for the classification of NSAID hypersensitivity has recently been proposed to diagnose and manage NSAID hypersensitivity for personalized treatment. Acute and delayed reactions were distinguished in this classification, and identification of symptoms and speculation of putative mechanisms help physicians make the right diagnosis. NSAID-exacerbated respiratory disease is a noticeable phenotype of NSAID hypersensitivity that involves upper airway comorbidities (chronic rhinosinusitis with nasal polyps) as well as asthmatic features. The cutaneous phenotypes of NSAID hypersensitivity occur, and cross-reactivity with other types of NSAID should be considered in establishing a proper diagnosis. Hypersensitivity to a single NSAID can present urticaria/angioedema and anaphylaxis, in which an IgE-mediated immune response is suggested to be a prime mechanism. Management of NSAID hypersensitivity reactions includes avoidance, pharmacological treatment following standard guidelines, and aspirin desensitization.

SUMMARY

The classification, diagnosis, and management of NSAID hypersensitivity should be individually reached by identifying its phenotype.

Clinical use of biologics for asthma treatment by allergy specialists: A questionnaire survey

BACKGROUND

Asthma is a heterogeneous disease with emerging phenotypes and endotypes. At present, 5 distinct biologics are Food and Drug Administration-approved as an add-on therapy for difficult-to-control type 2-high asthma. Because allergy specialists manage a spectrum of diseases for which biologics may be appropriate, it is important to understand their prescribing patterns.

OBJECTIVE

To elucidate the allergist's use of biologics in the treatment of asthma, including barriers, preferences, indications for prescribing, measures to determine effectiveness, and cost-effectiveness.

METHODS

A survey was performed among allergists using a semistructured 10-item self-administered web-based questionnaire and the responses were analyzed using one-way frequencies and multiple logistic regression.

RESULTS

The response rate was approximately 9%. Omalizumab was the most prescribed biologic for asthma (98%), and "uncontrolled asthma despite adherence to controller medication" was the most common reason. The common selection criteria among the biologics included elevated peripheral eosinophil count, asthma with nasal polyps, and asthma type (type 1; type 2; nonallergic). A decreased exacerbation frequency was the best standard to determine the efficacy among biologics. Benralizumab was considered the most cost-effective.

CONCLUSION

This study represents one of the largest surveys among allergy specialists regarding the real-world use of asthma biologics. It seems that there has been reasonably good dissemination and application of current guidelines among allergists based on prescribing patterns. However, their responses reflect the need for the continued modification of asthma guidelines that incorporate novel biologics and other pathway-specific agents into step therapy. As clinical phenotypes and predictive biomarkers develop, allergy specialists will be better prepared to practice precision medicine that optimizes the use of asthma biologics.

Biologic therapies versus surgical management for aspirin-exacerbated respiratory disease: A review of preliminary data, efficacy, and cost

Aspirin-exacerbated respiratory disease (AERD) patients with CRSwNP suffer from reduced quality of life, reduced economic productivity, and higher risk of depression and sleep dysfunction. These patients often require frequent medical and surgical therapy, including functional endoscopic sinus surgery for recalcitrant disease. Given this severity, anti-type 2 biologic treatments are being investigated for use in this subgroup of patients with CRSwNP, including Omalizumab and Dupilumab. Preliminary data suggests that SNOT-22 related quality of life improvements following treatment with biologics are comparable to the current standard of care in the short term, but there is a lack of long-term data and standardized regimen that makes direct comparison difficult. Biologic therapies additionally require continuous use to avoid recurrence, and currently cost many times more than existing medical or surgical therapies.

Aspirin sensitivity: Lessons in the regulation (and dysregulation) of mast cell function

The idiosyncratic activation of mast cells (MCs) in response to administration of nonselective COX inhibitors is a cardinal feature of aspirin-exacerbated respiratory disease (AERD). Older studies using MC-stabilizing drugs support a critical role for MCs and their products in driving the severe eosinophilic inflammation and respiratory dysfunction that is typical of AERD. Because patients with AERD react to all nonselective COX inhibitors regardless of their chemical structure, the mechanism of MC activation is not caused by classical, antigen-induced cross-linking of IgE receptors. Recent studies in both human subjects and animal models have revealed a complex and multifactorial process culminating in dysregulation of MC function and an aberrant dependency on COX-1-derived prostaglandin E₂ to maintain a tenuous homeostasis. This article reviews the factors most likely to contribute to MC dysregulation in patients with AERD and the potential diagnostic and therapeutic implications.

Aspirin-exacerbated respiratory disease: A review

OBJECTIVES

Aspirin-exacerbated respiratory disease (AERD) is a chronic respiratory condition characterized by a triad of symptoms: asthma, chronic rhinosinusitis with nasal polyposis, and a respiratory reaction to aspirin and other cyclooxygenase-1 inhibitors, also known as nonsteroidal anti-inflammatory drugs. The objective of this review is to provide otolaryngologists with an overview of the pathophysiology, diagnosis, and treatment of this under-recognized condition.

DATA SOURCES AND METHODS

Foundational papers on AERD were reviewed, focusing on the clinical otolaryngology and allergy/immunology literature and other high impact journals or trials.

RESULTS

AERD results from increased production of pro-inflammatory leukotrienes and a decrease in production of anti-inflammatory prostaglandins associated with the dysregulation of multiple enzymes influencing eicosanoid metabolism. Diagnosis hinges on a high index of suspicion, careful history, and confirmatory testing for all three elements. Treatments include endoscopic sinus surgery; topical, inhaled, or oral corticosteroids; aspirin desensitization; leukotriene modifying drugs; and the new class of biologics such as dupilumab.

CONCLUSION

AERD is an under-recognized disease associated with substantial patient-reported morbidity. We expect rapid progress in the pathophysiological understanding of this disease and available treatments in the coming decades.

LEVEL OF EVIDENCE

5.

Aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease (AERD) classically presents with severe asthma, nasal polyposis, and respiratory exacerbations in response to cyclooxygenase (COX)-1 inhibition. Recent advances in our understanding of AERD have revealed multiple facets of immune dysregulation, including diminished prostaglandin E2 (PGE₂) function and elevated levels of both cysteinyl leukotrienes (CysLTs) and innate cytokines such as interleukin 33 (IL-33). Inflammatory mediators in AERD heighten the recruitment and activation of innate lymphoid cells type 2 (ILC2), mast cells, eosinophils, and platelet-adherent leukocytes. This contributes to a cyclical pattern of type 2 inflammation. Here, we highlight current understanding of the immunopathogenesis of AERD.

Biologics in chronic rhinosinusitis with nasal polyposis

OBJECTIVE

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common and heterogeneous inflammatory condition, for which the drivers of the underlying inflammation are not yet fully understood. The use of biologic therapies to target specifically relevant effector cells or cytokines in CRSwNP is a growing field of interest. The objectives of this review are to provide an update on the existing studies of biologics in CRSwNP and to identify potential future areas for further research.

DATA SOURCES

An initial literature review of biologic therapies in CRS was performed through publications gathered from a PubMed search for title/abstract containing "biologic" and "chronic rhinosinusitis." Further manuscripts describing scientific premise for each biologic were then reviewed.

STUDY SELECTIONS

A detailed review of all studies describing biologic therapies targeting inflammation in CRSwNP was performed.

RESULTS

Biologic therapies targeting interleukin (IL)-4Rα, IL-5, IL-5Rα, IL-33, immunoglobulin (Ig)E, and thymic stromal lymphopoietin (TSLP) have all been developed and have been investigated for treatment in CRSwNP, or current research suggests that they may have utility in this area. Only dupilumab, which inhibits IL-4Rα, has gained Food and Drug Administration approval for the treatment of adults with inadequately controlled CRSwNP.

CONCLUSION

Recent advances in our understanding of the fundamental drivers of the chronic respiratory inflammation in CRSwNP has led to the identification of several potential therapeutic targets for this disease. Future clinical success will rely on the availability of biomarker-based endotyping and responder analyses so that clinicians can precisely match each patient to the appropriate biologic, thereby optimizing the proper treatment strategy.

IL-5Rα marks nasal polyp IgG4- and IgE-expressing cells in aspirin-exacerbated respiratory disease

BACKGROUND

The cause of severe nasal polyposis in aspirin-exacerbated respiratory disease (AERD) is unknown. Elevated antibody levels have been associated with disease severity in nasal polyps, but upstream drivers of local antibody production in nasal polyps are undetermined.

OBJECTIVE

We sought to identify upstream drivers and phenotypic properties of local antibody-expressing cells in nasal polyps from subjects with AERD.

METHODS

Sinus tissue was obtained from subjects with AERD, chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP), CRS without nasal polyps, and controls without CRS. Tissue antibody levels were quantified via ELISA and immunohistochemistry and were correlated with disease severity. Antibody-expressing cells were profiled with single-cell RNA sequencing, flow cytometry, and immunofluorescence, with IL-5Rα function determined through IL-5 stimulation and subsequent RNA sequencing and quantitative PCR.

RESULTS

Tissue IgE and IgG4 levels were elevated in AERD compared with in controls (P < .01 for IgE and P < .001 for IgG4 vs CRSwNP). Subjects with AERD whose nasal polyps recurred rapidly had higher IgE levels than did subjects with AERD, with slower regrowth (P = .005). Single-cell RNA sequencing revealed increased IL5RA, IGHG4, and IGHE in antibody-expressing cells from patients with AERD compared with antibody-expressing cells from patients with CRSwNP. There were more IL-5Rα⁺ plasma cells in the polyp tissue from those with AERD than in polyp tissue from those with CRSwNP (P = .026). IL-5 stimulation of plasma cells in vitro induced changes in a distinct set of transcripts.

CONCLUSIONS

Our study identifies an increase in antibody-expressing cells in AERD defined by transcript enrichment of IL5RA and IGHG4 or IGHE, with confirmed surface expression of IL-5Rα and functional IL-5 signaling. Tissue IgE and IgG4 levels are elevated in AERD, and higher IgE levels are associated with faster nasal polyp regrowth. Our findings suggest a role for IL-5Rα⁺ antibody-expressing cells in facilitating local antibody production and severe nasal polyps in AERD.