Plasma tryptase elevation during aspirin-induced reactions in aspirin-exacerbated respiratory disease

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.

Mast Cells in Aspirin-Exacerbated Respiratory Disease

PURPOSE OF REVIEW

Aspirin-exacerbated respiratory disease (AERD) is a syndrome of high type 2 inflammation and is known to critically involve mast cell activation. The mast cell is an important cell in the baseline inflammatory processes in the upper and lower airway by maintaining and amplifying type 2 inflammation. But it also is prominent in the hypersensitivity reaction to COX-1 inhibition which defines this condition.

RECENT FINDINGS

Recent work highlights the mast cell as a focal point in AERD pathogenesis. Using AERD as a specific model of both high type 2 asthma and chronic sinusitis, the role of mast cell activity can be better understood in other aspects of airway inflammation. Further dissecting out the mechanism of COX-1-mediated mast cell activation in AERD will be an important next phase in our understanding of NSAID-induced hypersensitivity as well as AERD pathophysiology.

Mechanistic and clinical updates in AERD: 2021-2022

Aspirin-exacerbated respiratory disease (AERD) is a unique and often clinically severe disease affecting a subgroup of adults with asthma and chronic rhinosinusitis with nasal polyposis. Works published in 2021-2022 confirmed the critical role of lipid mediator dysregulation and mast cell activation and expanded our understanding of basophils, macrophages, fibrin dysregulation, and the 15-lipoxygenase pathway in disease pathogenesis. Translational studies established inflammatory heterogeneity in the upper and lower airway at baseline and during aspirin-induced respiratory reactions. Clinical cohorts provided insights into the mechanistic actions of frequently utilized biologic therapies in AERD. These advances are already changing clinical care delivery and affecting patient outcomes. Despite this, further work is needed to improve clinical tools to reliably diagnose AERD and identify factors that could prevent development of the disease altogether. Additionally, the impact of inflammatory heterogeneity on clinical trajectories and the utility and safety of combination biologic and daily aspirin therapies remains unanswered.

Causes and Diagnostic Usefulness of Tryptase Measurements for Anaphylaxis in a Korean Tertiary Care General Hospital

PURPOSE

The causes of anaphylaxis in a general hospital may differ from those occurring in a community setting. Underlying diseases in admitted patients and vague presenting symptoms can make the diagnosis of anaphylaxis difficult. Serum tryptase measurements may provide valuable evidence for diagnosing anaphylaxis in admitted patients.

MATERIALS AND METHODS

This study was designed as a retrospective study of 53 patients with an anaphylaxis episode at a Korean tertiary care general hospital. Tryptase levels were measured at baseline and different time points from the onset of anaphylaxis.

RESULTS

Drugs (42 cases; 79.2%) and foods (10 cases; 18.9%) were the most common causes of anaphylaxis. In drug-induced anaphylaxis, antibiotics (24.5%), anticancer medications, which included monoclonal antibodies (22.6%), and contrast agents (11.3%) were the most frequent causes. The muscle relaxant eperisone (5.7%), neuromuscular blocking agent rocuronium (5.7%), and its antagonist sugammadex (3.8%) were other frequent triggering agents. Wheat-dependent exercise-induced anaphylaxis was the most common entity in food-induced anaphylaxis. Tryptase concentrations were higher in patients with higher grades of anaphylaxis, as well as in accidental anaphylaxis, compared to meticulously provoked anaphylaxis. Overall diagnostic sensitivity was higher for tryptase algorithm criteria (≥[1.2×baseline+2] µg/L: 71.4%) than for abnormal tryptase level criteria (≥11.4 µg/L: 52.8%).

CONCLUSION

The triggers of anaphylaxis in a Korean tertiary care hospital were diverse, including beta-lactam antibiotics, anticancer medications, contrast medias, eperisone, nonsteroidal anti-inflammatory drugs, rocuronium, sugammadex, and wheat. Tryptase measurements provided valuable evidence for diagnosis, and the sensitivity of algorithm criteria was superior to that of the abnormal value criteria.

NSAID-exacerbated respiratory disease (N-ERD): a population study

Background

Nonsteroidal anti-inflammatory drugs (NSAIDs) may exacerbate respiratory symptoms. A recent European Academy of Allergy and Clinical Immunology position paper recommended the use of an acronym, N-ERD (NSAID-exacerbated respiratory disease), for this hypersensitivity associated with asthma or chronic rhinosinusitis with or without nasal polyposis. Our aim was to estimate the prevalence of N-ERD and identify factors associated with N-ERD.

Methods

In 2016, a cross-sectional questionnaire survey of a random adult population of 16 000 subjects aged 20–69 years was performed in Helsinki and Western Finland. The response rate was 51.5%.

Results

The prevalence was 1.4% for N-ERD, and 0.7% for aspirin-exacerbated respiratory disease (AERD). The prevalence of N-ERD was 6.9% among subjects with asthma and 2.7% among subjects with rhinitis. The risk factors for N-ERD were older age, family history of asthma or allergic rhinitis, long-term smoking and exposure to environmental pollutants. Asthmatic subjects with N-ERD had a higher risk of respiratory symptoms, severe hypersensitivity reactions and hospitalisations than asthmatic subjects without N-ERD. The subphenotype of N-ERD with asthma was most symptomatic. Subjects with rhinitis associated with N-ERD, which would not be included in AERD, had the fewest symptoms.

Conclusion

We conclude that the prevalence of N-ERD was 1.4% in a representative Finnish adult population sample. Older age, family history of asthma or allergic rhinitis, cumulative exposure to tobacco smoke, secondhand smoke, and occupational exposures increased odds of N-ERD. N-ERD was associated with significant morbidity.

Population-based prevalence of N-ERD is 1.4%. N-ERD is symptomatic, with a rhinitis subgroup. The risk factors for N-ERD are older age, family history of asthma or allergic rhinitis, long-term smoking and exposure to environmental pollutants.https://bit.ly/3HxGftP

Mediator production and severity of aspirin-induced respiratory reactions: Impact of sampling site and body mass index

BACKGROUND

Patients with aspirin-exacerbated respiratory disease can experience severe reactions during aspirin challenge that are associated with high levels of mast cell mediators. The tissue source and clinical factors contributing to systemic mediator levels are unknown.

OBJECTIVE

To determine the concordance between respiratory tract and systemic inflammatory mediator levels and identify clinical factors associated with these mediators.

METHODS

We performed an oral aspirin challenge in 30 subjects with aspirin-exacerbated respiratory disease. Respiratory symptoms and function, nasal mucosal fluid, blood, and urine were collected at baseline, at the onset of a respiratory reaction and over a 3-hour observation period. Changes in nasal and systemic mediator levels were compared.

RESULTS

Neither tryptase nor leukotriene E₄ levels in nasal fluid correlated with serum tryptase or urinary leukotriene E₄ at baseline or during reactions. We observed no association between the baseline or aspirin-induced change in nasal versus urinary leukotriene E₄ and serum tryptase levels. Body mass index inversely correlated with baseline and aspirin-induced urinary leukotriene E₄, prostaglandin D₂ metabolite, and serum tryptase levels, as well as with aspirin-induced symptoms and respiratory function, but not with nasal mediators.

CONCLUSION

The levels of nasal and systemic aspirin-induced mast cell products are discordant in aspirin-exacerbated respiratory disease. Systemically detected levels are likely derived from mast cells outside of the sinonasal cavity and do not accurately reflect upper respiratory tract production. Increased body mass index decreases systemic mast cell mediator production and reaction severity, supporting a contribution of metabolic regulation in aspirin-induced systemic reactions.

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.

Lipid-mediated innate lymphoid cell recruitment and activation in aspirin-exacerbated respiratory disease

OBJECTIVE

To synthesize investigations into the role of lipid-mediated recruitment and activation of group 2 innate lymphoid cells (ILC2s) in aspirin-exacerbated respiratory disease (AERD).

DATA SOURCES

A comprehensive literature review of reports pertaining to cellular mechanisms, cytokine, and lipid mediators in AERD, as well as ILC2 activation and recruitment, was performed using PubMed and Google Scholar.

STUDY SELECTIONS

Selections of studies were based on reports of lipid mediators in AERD, cytokine mediators in AERD, type 2 effector cells in AERD, platelets in AERD, AERD treatment, ILC2s in allergic airway disease, and ILC2 activation, inhibition, and trafficking.

RESULTS

The precise mechanisms of AERD pathogenesis are not well understood. Greater levels of proinflammatory lipid mediators and type 2 cytokines are found in tissues derived from patients with AERD relative to controls. After pathognomonic cyclooxygenase-1 inhibitor reactions, proinflammatory mediator concentrations (prostaglandin D2 and cysteinyl leukotrienes) are rapidly increased, as are ILC2 levels in the nasal mucosa. The ILC2s, which potently generate type 2 cytokines in response to lipid mediator stimulation, may play a key role in AERD pathogenesis.

CONCLUSION

Although the literature suggests that lipid-mediated ILC2 activation may occur in AERD, there is a dearth of definitive evidence. Future investigations leveraging novel next-generation single-cell sequencing approaches along with recently developed AERD murine models will better define lipid mediator-induced ILC2 trafficking in patients with AERD.

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.

Adult-onset eosinophilic airway diseases

Eosinophilic airway inflammation is one of the cardinal features of allergic airway diseases such as atopic asthma and allergic rhinitis. These childhood-onset conditions are mediated by allergen and allergen-specific IgE and often accompanied by other allergic diseases including food allergy and eczema. They can develop consecutively in the same patient, which is referred to as an allergic march. In contrast, some phenotypes of asthma, nonsteroidal anti-inflammatory drugs-exacerbated airway disease (N-ERD), chronic rhinosinusitis with nasal polyps (CRSwNP)/eosinophilic CRS and allergic bronchopulmonary aspergillosis/mycosis (ABPA/ABPM) are adult-onset airway diseases, which are characterized by prominent peripheral blood eosinophilia. Most of these conditions, except for ABPA/ABPM, are nonatopic, and the coexistence of multiple diseases, including an adult-onset eosinophilic systemic disease, eosinophilic granulomatosis with polyangiitis (EGPA), is common. In this review, we focus on eosinophil biology, genetics and clinical characteristics and the pathophysiology of adult-onset eosinophilic asthma, N-ERD, CRSwNP/eosinophilic CRS, ABPA/ABPM and EGPA, while exploring the common genetic, immunological and pathological conditions among these adult-onset eosinophilic diseases.

The Role of Mast Cells in Aspirin-Exacerbated Respiratory Disease (AERD) Pathogenesis: Implications for Future Therapeutics

Mast cells (MC) have recently been demonstrated to play an integral role in the pathogenesis of aspirin-exacerbated respiratory disease (AERD). When activated, MCs release pre-formed granules of many pro-inflammatory mediators, including histamine, serotonin, and various chemokines and cytokines including tumor necrosis factor (TNF)-α, interferon ɣ (IFN ɣ), macrophage inhibitory factor, transforming growth factor, interleukin (IL) 1, 3–6, 9, 10, 13 and 16. These mediators promote inflammation in AERD by recruiting or activating a network of cells involved in acute and chronic inflammatory pathways, such as endothelial, epithelial, stromal, and other immune cells. Several studies have implicated multifactorial pathways for MC activation in AERD beyond classical IgE mediated mechanisms. The elucidation of these complex networks therefore represents important targets for innovative patient therapeutics. This review summarizes classic and alternative pathways of MC activation in AERD with a special focus in relation to new and emerging treatment strategies.

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

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.

NSAID-ERD Syndrome: the New Hope from Prevention, Early Diagnosis, and New Therapeutic Targets

PURPOSE OF REVIEW

This review summarizes the latest information on the appropriate identification, evaluation, and treatment of patients with nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NSAID-ERD), also known as aspirin-exacerbated respiratory disease (AERD). Within the framework of our understanding of the underlying pathophysiology of NSAID-ERD, we also provide an update regarding new surgical techniques and newly available or upcoming medical therapies that may benefit these patients.

RECENT FINDINGS

There have been considerable developments regarding recommendations for both the extent and timing of sinus surgery for NSAID-ERD. The last few years have also given us several new biologic medications that warrant consideration in the treatment of patients with recalcitrant NSAID-ERD. Further clinical trials are underway to investigate additional medications that may decrease the type 2 inflammation that dominates this disease. Despite the severe lower respiratory inflammation and recurrent nature of the nasal polyps in patients with NSAID-ERD, significant recent advances now afford much-improved quality of life for these patients. Careful collaboration between Allergy/Immunology and Rhinology specialists is imperative to ensure proper treatment of patients with NSAID-ERD.

Nasal Polyposis and Aspirin-Exacerbated Respiratory Disease

Aspirin-exacerbated respiratory disease (AERD) is characterized by eosinophilic chronic rhinosinusitis with nasal polyps, asthma, and upper-/lower-respiratory tract reactions to nonsteroidal antiinflammatory drugs. Persistent, severe disease, anosmia, and alcohol sensitivity is typical. AERD is mediated by multiple pathways, including aberrant arachidonic acid metabolism leading to elevated leukotriene E4 and decreased prostaglandin E2. Mast cell mediators (prostaglandin D2) and unique properties of eosinophils and type 2 innate lymphoid cells, along with receptor-mediated signaling, also contribute to AERD pathogenesis. Pharmacologic therapies are a cornerstone of AERD treatment and include leukotriene modifiers, corticosteroids, biologics, and aspirin.

Aspirin Exacerbated Respiratory Disease: Epidemiology, Pathophysiology, and Management

The correlation between aspirin sensitivity, asthma, and nasal polyposis was recognized in the early 20th century. Today, this classic triad of symptoms, eponymously named Samter's Triad, is known as aspirin exacerbated respiratory disease (AERD). Aspirin exacerbated respiratory disease affects approximately 0.3⁻0.9% of the general population in the USA and approximately 7% of asthmatic patients. The management of AERD is challenging as no single modality has proven to have high rates of symptom control. Consequently, disease management typically involves a multimodality approach across both medical and surgical disciplines. This review describes the epidemiology of AERD and the current state-of-the-art as it relates to the underlying pathophysiologic mechanisms of this disease process. A significant proportion of the review is focused on the appropriate diagnostic workup for AERD patients including the utility of aspirin provocation testing. The spectrum of medical treatments, including aspirin desensitization and recently introduced immunotherapies, are discussed in detail. Furthermore, surgical approaches to disease control, including advanced endoscopic techniques, are reviewed and treatment outcomes presented.