Effect of leukotriene modifier drugs on the safety of oral aspirin challenges

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.

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.

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.

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.

Leukotriene D4 paradoxically limits LTC4-driven platelet activation and lung immunopathology

BACKGROUND

The 3 cysteinyl leukotrienes (cysLTs), leukotriene (LT) C₄ (LTC₄), LTD₄, and LTE₄, have different biologic half-lives, cellular targets, and receptor specificities. CysLT₂R binds LTC₄ and LTD₄in vitro with similar affinities, but it displays a marked selectivity for LTC₄in vivo. LTC₄, but not LTD₄, strongly potentiates allergen-induced pulmonary eosinophilia in mice through a CysLT₂R-mediated, platelet- and IL-33-dependent pathway.

OBJECTIVE

We sought to determine whether LTD₄ functionally antagonizes LTC₄ signaling at CysLT₂R.

METHODS

We used 2 different in vivo models of CysLT₂R-dependent immunopathology, as well as ex vivo activation of mouse and human platelets.

RESULTS

LTC₄-induced CD62P expression; HMGB1 release; and secretions of thromboxane A₂, CXCL7, and IL-33 by mouse platelets were all were blocked by a selective CysLT₂R antagonist and inhibited by LTD₄. These effects did not depend on CysLT₁R. Inhaled LTD₄ blocked LTC₄-mediated potentiation of ovalbumin-induced eosinophilic inflammation; recruitment of platelet-adherent eosinophils; and increases in IL-33, IL-4, IL-5, and IL-13 levels in lung tissue. In contrast, the effect of administration of LTE₄, the preferred ligand for CysLT₃R, was additive with LTC₄. The administration of LTD₄ to Ptges^-/- mice, which display enhanced LTC₄ synthesis similar to that in aspirin-exacerbated respiratory disease, completely blocked the physiologic response to subsequent lysine-aspirin inhalation challenges, as well as increases in levels of IL-33, type 2 cytokines, and biochemical markers of mast cell and platelet activation.

CONCLUSION

The conversion of LTC₄ to LTD₄ may limit the duration and extent of potentially deleterious signaling through CysLT₂R, and it may contribute to the therapeutic properties of desensitization to aspirin in aspirin-exacerbated respiratory disease.

Effect of LTRA in L-ASA Challenge for Aspirin-Exacerbated Respiratory Disease Diagnosis

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) consists of asthma, chronic rhinosinusitis with polyps, and hypersensitivity to aspirin and/or nonsteroidal anti-inflammatory drugs (NSAIDs). Nasal Lysine Aspirin Challenge is an effective tool for the diagnosis of hypersensitivity to aspirin and/or NSAIDs in patients with AERD. However, there is no unified international consensus version to perform nasal provocation tests (NPTs).

OBJECTIVE

To investigate the effect of a leukotriene receptor antagonist (LTRA), montelukast, on the lysine-acetylsalicylate (L-ASA) nasal challenge.

METHODS

We included 86 patients divided into 3 samples: group A (AERD without LTRA), group B (AERD with LTRA), and the control group (NSAID-tolerant asthmatics). NPT with L-ASA was performed with 25 mg of L-ASA every 30 minutes 4 times followed by rhinomanometry and spirometric measurements and evaluation of symptoms using a novel clinical scale.

RESULTS

In group A, 94.5% of patients (35 of 37) developed a positive response to NPT (drop >40% in total nasal flow), whereas only 46% of group B subjects (13 of 28) showed a positive response to the nasal challenge (P < .001). Control subjects did not show any response to the L-ASA challenge. A novel clinical score demonstrated accuracy in classifying the hypersensitivity to aspirin and/or NSAIDs when patients avoid LTRA (33 of 37).

CONCLUSION

Patients with AERD without LTRA showed a greater positive response to the L-ASA challenge than those taking this drug; therefore, LTRA treatment should be discontinued before the challenge for optimal diagnostic accuracy.

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.

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.

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.

Endoscopic sinus surgery improves aspirin treatment response in aspirin-exacerbated respiratory disease patients

BACKGROUND

Aspirin desensitization and treatment benefits most patients with aspirin-exacerbated respiratory disease (AERD), although some patients fail therapy. Our objective was to assess whether recent endoscopic sinus surgery (ESS) improved aspirin treatment outcomes in AERD patients who initially failed aspirin therapy.

METHODS

Outcomes of aspirin desensitization and treatment in AERD patients prospectively enrolled were assessed preoperatively and at 4, 12, and 24 weeks after ESS by determining changes in Asthma Control Test (ACT) and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores and respiratory function. Biomarkers, including fractional excretion of nitric oxide (FeNO), spirometry, nasal inspiratory peak flow (NPF), immunoglobulin E (IgE), and eosinophil count, were measured.

RESULTS

Nineteen patients who benefited (responders) and 21 patients who failed (nonresponders) preoperative aspirin treatment with a distant history of ESS (mean, 48 months) were identified. Nonresponders were more likely to be African American (71%, p < 0.01) and have higher baseline IgE levels (252 kU/L vs 87 kU/L in responders, p < 0.01). 24 of the 40 patients (nine responders and 15 non-responders) required subsequent ESS and underwent another aspirin desensitization 3-4 weeks after ESS. All 24 patients tolerated a second round of aspirin desensitization and treatment. The primary aspirin therapy was associated with a significant increase in IgE in nonresponders, but there was no significant increase in IgE after the second aspirin desensitization and treatment.

CONCLUSION

Antecedent ESS enhances aspirin treatment responses in AERD patients and may convert patients who failed aspirin treatment before surgery to a more responsive phenotype after ESS. Patients with higher baseline serum IgE levels may benefit from ESS performed shortly before aspirin desensitization and therapy.

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.

Objective and subjective sinonasal and pulmonary outcomes in aspirin desensitization therapy: A prospective cohort study

OBJECTIVE

Aspirin exacerbated respiratory disease (AERD) patients are challenging to manage with sinonasal and pulmonary symptoms refractory to maximal medical and surgical therapies. Our objective was to comprehensively examine objective and validated, disease-specific subjective sinonasal and pulmonary outcomes of aspirin (ASA) desensitization therapy in this patient population.

METHODS

Prospective cohort study at an academic tertiary center. AERD patients with a history of chronic rhinosinusitis with nasal polyposis (CRSwNP), prior diagnosis of asthma, and a history of ASA sensitivity were eligible for inclusion. Patients underwent ASA desensitization using an established institutional protocol and continued on a 650mg twice daily maintenance dose. Baseline Sinonasal Outcome Test (SNOT-22) and Asthma Control Questionnaire (ACQ) responses, acoustic rhinometry, peak flow readings, and endoscopic scoring of nasal polyps were recorded prior to desensitization and after 6months of maintenance therapy.

RESULTS

Twelve patients were recruited for participation and underwent desensitization. Eight patients continued maintenance therapy and follow up at 6months. Prior to desensitization, patients reported bothersome sinonasal symptoms with a median SNOT-22 score of 30.0±34.5 (interquartile range (IQR)). There was significant improvement after 6months of maintenance therapy to a median SNOT-22 score of 18.5±17.3 (p=0.025, Wilcoxon signed rank test). Acoustic rhinometry, endoscopic scores, ACQ and forced expiratory volume values remained stable at 6months.

CONCLUSIONS

AERD patients may benefit from ASA desensitization with subjective sinonasal symptom improvement at 6months and stable asthma and objective sinonasal measures. Further discussion is needed in the otolaryngology community regarding ASA desensitization in AERD management.

Multiple Drug Intolerance Syndrome: An Underreported Distinct Clinical Entity

Aim:

Multiple drug intolerance syndrome (MDIS) is a unique clinical entity distinct from other drug hypersensitivity syndromes. The aim of this review was to critically appraise the various aspects of MDIS.

Methods

A review was conducted to search for the causes, mechanism, clinical features, and management of MDIS.

Results

The most common cause of MDIS is antibiotics followed by non-steroidal anti-inflammatory drugs (NSAIDs). Although some non-specific immunological mechanisms are involved, the immunological tests for MDIS are negative. Rashes, gastrointestinal reflux, headache, cough, muscle ache, fever, dermatitis, hypertension, and psychiatric symptoms are the usual manifestations. Treatment is mostly symptomatic with the withdrawal of the offending drug. Drug re-challenges and desensitization may be required for the management of this syndrome.

Conclusion

MDIS occurs by a nonimmune mechanism which requires a prompt withdrawal of the offending drug(s), and in some cases may require drug re-challenge and desensitization.

Pathogenesis of NSAID-induced reactions in aspirin-exacerbated respiratory disease

It is well-established that following ingestion of aspirin or any other inhibitor of cyclooxygenase-1, patients with Samter's disease, or aspirin-exacerbated respiratory disease (AERD) develop the sudden onset of worsening respiratory clinical symptoms, which usually involves nasal congestion, rhinorrhea, wheezing and bronchospasm. Gastrointestinal distress, nausea, a pruritic rash and angioedema can also occasionally develop. However, the underlying pathologic mechanism that drives these clinical reactions remains elusive. Pretreatment with medications that inhibit the leukotriene pathway decreases the severity of clinical reactions, which points to the involvement of cysteinyl leukotrienes (cysLTs) in the pathogenesis of these aspirin-induced reactions. Furthermore, studies of aspirin challenges in carefully-phenotyped patients with AERD have confirmed that both proinflammatory lipid mediators, predominantly cysLTs and prostaglandin (PG) D₂, and the influx of effector cells to the respiratory tissue, contribute to symptom development during aspirin-induced reactions. Mast cells, which have been identified as the major cellular source of cysLTs and PGD₂, are likely to be major participants in the acute reactions, and are an attractive target for future pharmacotherapies in AERD. Although several recent studies support the role of platelets as inflammatory effector cells and as a source of cysLT overproduction in AERD, it is not yet clear whether platelet activation plays a direct role in the development of the aspirin-induced reactions. To further our understanding of the pathogenesis of aspirin-induced reactions in AERD, and to broaden the pharmacotherapeutic options available to these patients, additional investigations with targeted clinical trials will be required.

Aspirin exacerbated respiratory disease: Current topics and trends

Aspirin-exacerbated respiratory disease is a chronic and treatment-resistant disease, characterized by the presence of eosinophilic rhinosinusitis, nasal polyposis, bronchial asthma, and nonsteroidal anti-inflammatory drugs hypersensitivity. Alterations in arachidonic acid metabolism may induce an imbalance between pro-inflammatory and anti-inflammatory substances, expressed as an overproduction of cysteinyl leukotrienes and an underproduction of prostaglandin E2. Although eosinophils play a key role, recent studies have shown the importance of other cells and molecules in the development of the disease like mast cells, basophils, lymphocytes, platelets, neutrophils, macrophages, epithelial respiratory cells, IL-33 and thymic stromal lymphopoietin, making each of them promissory diagnostic and treatment targets. In this review, we summarize the most important clinical aspects of the disease, including the current topics about diagnosis and treatment, like provocation challenges and aspirin desensitization. We also discuss recent findings in the pathogenesis of the disease, as well as future trends in diagnosis and treatment, including monoclonal antibodies and a low salicylate diet as a treatment option.

An update on the management of aspirin-exacerbated respiratory disease

INTRODUCTION

Clinical features of aspirin-exacerbated respiratory disease (AERD) consist of moderate to severe asthma associated with chronic rhinosinusitis (CRS), which are derived from overproduction of cysteinyl leukotrienes along with chronic type 2 mediated inflammation in the upper and lower airway mucosa. Area covered: This review provides recent up-to-date information regarding phenotypes of AERD and encompasses comprehensive diagnostic methods and treatment options. To confirm the diagnosis of AERD, provocation testing via nasal, inhalation or the oral route of aspirin remains the gold standard; in vitro diagnostic methods are still not available. Essential management is to avoid cross-reacting cyclooxygenase 1 (COX-1) inhibitors along with use of highly selective COX-2 inhibitors and to maintain pharmacologic treatment depending on the severity of asthma and chronic rhinosinusitis. Recent biologics, including anti-IgE and anti-IL5 antibodies, are required in severe AERD patients with CRS. Aspirin desensitization can be recommended when indicated. Expert commentary: AERD is a heterogeneous disease in terms of severity and associated allergic disease. When performing diagnosis and treatment for AERD, such disease characteristics need to be kept in mind.

Aspirin and Nonsteroidal Antiinflammatory Drugs Hypersensitivity and Management

Aspirin and nonsteroidal antiinflammatory drugs (NSAIDs) are widely used in the United States and throughout the world for a variety of indications. Several unique hypersensitivity syndromes exist to this class of medications, making them one of the common reasons for consultation to the allergist. The lack of any laboratory-based diagnostic studies to assist in identifying the culprits in these reactions make evaluation of aspirin and NSAID hypersensitivity challenging. Identifying patients appropriate for oral challenge and/or desensitization protocols is the standard pragmatic approach to this issue when it arises.

Effect of misoprostol on patients with aspirin-exacerbated respiratory disease undergoing aspirin challenge and desensitization

BACKGROUND

Prostaglandin E₂ (PGE₂) is an anti-inflammatory compound that inhibits 5-lipoxygenase activity. Diminished PGE₂ regulation in aspirin-exacerbated respiratory disease (AERD) leads to respiratory reactions on cyclooxygenase 1 inhibition. In vitro studies have found that exogenous PGE₂ stabilizes inflammatory mediator release.

OBJECTIVE

To examine whether misoprostol (oral prostaglandin E₁ analogue) use during aspirin challenge and desensitization might decrease the severity of aspirin-induced symptoms and make desensitization safer for patients with AERD.

METHODS

Forty-five patients undergoing aspirin challenge and/or desensitization were randomized to misoprostol (n = 30) or placebo (n = 15) and compared with a group of historical controls (n = 31). Misoprostol (200 μg) was administered at 30 minutes, 90 minutes, and 4 hours after the first dose of nasal ketorolac. Measured end points included change in forced expiratory volume in 1 second (FEV₁), peak nasal inspiratory flow rate (PNIF), number of treatments received for induced reactions, and adverse gastrointestinal effects.

RESULTS

A difference in FEV₁ and PNIF reduction was detected between misoprostol and placebo (P = .03) and misoprostol and historical controls (P = .01), respectively, during nasal ketorolac challenge. No difference was detected among aspirin reactors. Among all reactors, no difference in magnitude was found for FEV₁ (P = .13) or PNIF (P = .07) reduction across all 3 groups. Total treatment requirement was similar (P = .14). Patients receiving misoprostol were more likely to report adverse gastrointestinal effects (P = .02).

CONCLUSION

The addition of misoprostol to current aspirin challenge and/or desensitization protocols reveals no protective effect in reducing the intensity of nonsteroidal anti-inflammatory drug-induced symptoms and is not recommended based on the findings in this study.

Safety and outcomes of aspirin desensitization for aspirin-exacerbated respiratory disease: A single-center study

BACKGROUND

Aspirin desensitization is an effective treatment option for aspirin-exacerbated respiratory disease. Aspirin desensitization protocol modifications have improved the safety and efficiency of this procedure, yet some providers remain reluctant to perform it.

OBJECTIVE

The primary objective of this study was to evaluate the safety and outcomes of outpatient aspirin desensitization procedures. A secondary objective was to assess clinical characteristics that might predict reaction severity during aspirin desensitization.

METHODS

Two hundred seventy-five patients underwent aspirin desensitization at Scripps Clinic between January 2009 and August 2015. Baseline patient characteristics and reaction results were analyzed in the 167 patients who reacted during desensitization.

RESULTS

All of the 167 reactors, including 23 who were classified as severe reactors, were successfully desensitized in the outpatient setting. The average desensitization duration among reactors was 1.67 days, and the average duration for gastrointestinal reactors was 2.29 days. The mean baseline Sino-Nasal Outcome Test score was higher in severe reactors compared with nonsevere reactors (P = .05). Overall, patients receiving omalizumab had a similar reaction profile to those not receiving omalizumab.

CONCLUSIONS

Most patients undergoing aspirin desensitization will have symptoms. It remains difficult to predict the severity of these symptoms. However, desensitization can be done safely and efficiently in an appropriately equipped outpatient setting. This treatment option should be made available to all patients with aspirin-exacerbated respiratory disease. The Sino-Nasal Outcome Test score might be able to predict more severe reactions and merits further study. Eight of the 9 patients receiving omalizumab reacted during desensitization, suggesting that it does not block reactions during aspirin desensitization.

Aspirin-Exacerbated Respiratory Disease

Aspirin-exacerbated respiratory disease (AERD) is characterized by the triad of asthma, sinonasal polyposis, and aspirin intolerance. The hallmark of the disease is baseline overproduction of cysteinyl leukotrienes via the 5-lipoxygenase pathway, exacerbated by ingestion of aspirin. Patients with AERD have high rates of recidivistic polyposis following sinus surgery, although the improvement in quality of life following surgery is similar to aspirin-tolerant patients. The diagnosis is secured by a positive aspirin provocation test, usually administered by a medical allergist. Aspirin therapy is a unique treatment consideration for patients with AERD.

Plasma 15-Hydroxyeicosatetraenoic Acid Predicts Treatment Outcomes in Aspirin-Exacerbated Respiratory Disease

BACKGROUND

Aspirin desensitization followed by daily aspirin provides therapeutic benefits to patients with aspirin-exacerbated respiratory disease (AERD). It is not well understood how eicosanoid levels change during aspirin treatment.

OBJECTIVE

To investigate associations between clinical outcomes of aspirin treatment and plasma eicosanoid levels in patients with AERD.

METHODS

Thirty-nine patients with AERD were offered aspirin treatment (650 mg twice daily) for 4 weeks. Respiratory parameters and plasma levels of multiple eicosanoids were recorded at baseline and after 4 weeks of aspirin therapy using the Asthma Control Test and Rhinoconjunctivitis Quality of Life Questionnaire. Respiratory function was evaluated using the FEV₁ and nasal inspiratory peak flow.

RESULTS

After aspirin treatment, respiratory symptoms improved in 16 patients, worsened in 12 patients, and did not change in 4 patients. Seven patients were unable to complete the desensitization protocol. Patients with symptom improvement had higher baseline plasma 15-hydroxyeicosatetraenoic acid (15-HETE) levels than did patients with symptom worsening: 7006 pg/mL (interquartile range, 6056-8688 pg/mL) versus 4800 pg/mL (interquartile range, 4238-5575 pg/mL), P = .0005. Baseline 15-HETE plasma levels positively correlated with the change in Asthma Control Test score (r = 0.61; P = .001) and in FEV₁ after 4 weeks of aspirin treatment (r = 0.49; P = .01). It inversely correlated with Rhinoconjunctivitis Quality of Life Questionnaire score (r = -0.58; P = .002). Black and Latino patients were more likely to have symptom worsening on aspirin or fail to complete the initial desensitization than white, non-Latino patients (P = .02).

CONCLUSIONS

In patients with AERD, low baseline 15-HETE plasma levels and black or Latino ethnicity are associated with worsening of respiratory symptoms during aspirin treatment.

Current complications and treatment of aspirin-exacerbated respiratory disease

INTRODUCTION

Aspirin-exacerbated respiratory disease is defined by the clinical tetrad of aspirin sensitivity, nasal polyps, asthma, and chronic rhinosinusitis. Patients experience acute upper and lower airway reactions with exposure to aspirin and other cyclooxygenase-1 inhibiting medications. However, airway inflammation and disease progression occur even in the absence of exposure to these medications, often leading to aggressive polyp formation and need for systemic corticosteroids to treat exacerbations in asthma and rhinosinusitis. Areas covered: This review focuses on the direct and indirect complications of aspirin-exacerbated respiratory disease. Current and potential management strategies are discussed with emphasis on aspirin desensitization. Expert commentary: Aspirin desensitization remains the gold standard of treatment. Demonstrated benefits of desensitization include improved symptom scores, reduction in use of systemic corticosteroids, slowing of polyp regrowth, and tolerance of aspirin and other NSAIDs for various therapeutic purposes. Continued investigation into the pathogenic mechanisms of AERD is likely to yield new diagnostic and therapeutic approaches.

Risk and safety requirements for diagnostic and therapeutic procedures in allergology: World Allergy Organization Statement

One of the major concerns in the practice of allergy is related to the safety of procedures for the diagnosis and treatment of allergic disease. Management (diagnosis and treatment) of hypersensitivity disorders involves often intentional exposure to potentially allergenic substances (during skin testing), deliberate induction in the office of allergic symptoms to offending compounds (provocation tests) or intentional application of potentially dangerous substances (allergy vaccine) to sensitized patients. These situations may be associated with a significant risk of unwanted, excessive or even dangerous reactions, which in many instances cannot be completely avoided. However, adverse reactions can be minimized or even avoided if a physician is fully aware of potential risk and is prepared to appropriately handle the situation. Information on the risk of diagnostic and therapeutic procedures in allergic diseases has been accumulated in the medical literature for decades; however, except for allergen specific immunotherapy, it has never been presented in a systematic fashion. Up to now no single document addressed the risk of the most commonly used medical procedures in the allergy office nor attempted to present general requirements necessary to assure the safety of these procedures. Following review of available literature a group of allergy experts within the World Allergy Organization (WAO), representing various continents and areas of allergy expertise, presents this report on risk associated with diagnostic and therapeutic procedures in allergology and proposes a consensus on safety requirements for performing procedures in allergy offices. Optimal safety measures including appropriate location, type and required time of supervision, availability of safety equipment, access to specialized emergency services, etc. for various procedures have been recommended. This document should be useful for allergists with already established practices and experience as well as to other specialists taking care of patients with allergies.

Performing Aspirin Desensitization in Aspirin-Exacerbated Respiratory Disease

Aspirin-exacerbated respiratory disease (AERD) is characterized by chronic rhinosinusitis with nasal polyps, asthma, and reactions to cyclooxygenase-1-inhibiting drugs. This condition is often refractory to standard medical treatments and results in aggressive nasal polyposis that often requires multiple sinus surgeries. Aspirin desensitization followed by daily aspirin therapy is an important treatment option, and its efficacy has been validated in multiple research studies. Aspirin desensitization is not without risk, but specific protocols and recommendations exist to mitigate the risk. Most patients with AERD can undergo aspirin desensitization in an outpatient setting under the supervision of an allergist.

Clinical Characteristics of Aspirin-Exacerbated Respiratory Disease

Aspirin-exacerbated respiratory disease is a significant endotype of both asthma and chronic rhinosinusitis with nasal polyps. The disease demonstrates what seems to be a unified inflammatory mechanism culminating in highly eosinophilic nasal polyp disease and asthma. The rate of polyp recurrence and morbidity from asthma exacerbations are significant and warrant separating this group diagnostically from aspirin-tolerant peers. Given the unique anti-inflammatory effects of aspirin and the evolving landscape of new, targeted biologic treatments, it is even more incumbent to consider this diagnosis and offer patients treatment specific for the disease.

Diagnostic Evaluation in Aspirin-Exacerbated Respiratory Disease

Aspirin-exacerbated respiratory disease (AERD) is a distinct clinical condition characterized by chronic sinusitis with nasal polyps, asthma, and hypersensitivity reactions to nonsteroidal anti-inflammatory drugs (NSAIDs). Distinguishing AERD from other forms of chronic sinusitis, asthma, and NSAID reactivity has important clinical implications for management. The clinical history is helpful, but not adequate for confirming the diagnosis of AERD, in most cases. Diagnostic provocation challenge remains the only way to confirm or exclude the diagnosis of AERD. This article discusses the utility of the clinical history and the current evidence regarding measures that optimize the safety of performing diagnostic NSAID provocation challenges.

[ASA-intolerance syndrome and persistent rhinosinusitis : Differential diagnosis and treatment]

BACKGROUND

A differential diagnosis of persistent chronic rhinosinusitis is ASA-intolerance syndrome (AIS), also known as Aspirin®‑exacerbated respiratory disease (AERD), Samter-Trias (Samter's disease, Morbus Widal). Particularly in cases of frequent recurrency of nasal polyps in combination with bronchial asthma and hypersensitivity reactions to acetylsalicylic acid (ASA) and other nonsteroidal anti-inflammatory drugs (NSAR) can often be referred to an underlying AIS. The pathogenesis of this syndrome is attributed to a misallocation of the arachidonic acid metabolism, resulting in an increased leukotriene production.

METHODS

The diagnosis may be difficult in the early stages of the disease with incomplete triad of symptoms.

RESULTS

Therapy may consist of paranasal sinuses surgery, drug therapy and adaptive deactivation as the only causal treatment option for patients with AIS.

CONCLUSION

For adaptive desactivation, positive effects were actually shown even in patients with long-term recurrent or persistent complaints of chronic rhinosinusitis.

Utility of low-dose oral aspirin challenges for diagnosis of aspirin-exacerbated respiratory disease

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is diagnosed through graded aspirin challenges that induce hypersensitivity reactions and eicosanoid level changes. It is not known whether diagnostically useful changes also occur after low-dose aspirin challenges that do not induce hypersensitivity reactions.

OBJECTIVE

To investigate the utility of low-dose oral aspirin challenges for diagnosing AERD by measuring different clinical parameters and eicosanoid changes.

METHODS

Sixteen patients with AERD and 13 patients with aspirin-tolerant asthma underwent oral challenges with low-dose (20 or 40 mg) aspirin and diagnostic oral graded aspirin challenges (up to 325 mg of aspirin). Forced expiratory volume in 1 second, nasal peak flow, the fraction of exhaled nitric oxide (FeNO), and eicosanoid levels in plasma and urine were analyzed.

RESULTS

In patients with AERD but not in those with aspirin-tolerant asthma, 40-mg aspirin challenges induced a significant mean (SEM) decrease from baseline in FeNO (19% [5.1%]; P = .001) without causing any hypersensitivity reaction. The FeNO decrease also occurred after higher-dose aspirin challenges (27.8% [4.9%]; P < .001). The sensitivity and specificity of 40-mg aspirin-induced FeNO changes for identifying AERD were 90% and 100% with an area under the curve of 0.98 (95% CI, 0.92-1.00). The low-dose challenge also induced a significant leukotriene E4 urine increase in patients with AERD (from 6.32 [0.08] to 6.91 [0.15] log-pg/mg creatinine; P < .001), but the sensitivity and specificity of these changes were less than for the FeNO changes.

CONCLUSION

The low-dose aspirin-induced decrease in FeNO in patients with AERD may be useful for the diagnosis of aspirin allergy without inducing a hypersensitivity reaction.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01320072.

Hypersensitivity to Aspirin and other NSAIDs: Diagnostic Approach in Patients with Chronic Rhinosinusitis

Hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs) associated with chronic rhinosinusitis (CRS) and/or asthma comprises a distinct clinical syndrome referred to as NSAIDs exacerbated respiratory disease (NERD). Patients with NERD tend to have more severe course of both upper (CRS and nasal polyps) and lower airway (asthma) diseases and are usually recalcitrant to conventional treatment modalities. Diagnosing and phenotyping of patients with NERD are critical for prevention of drug-induced adverse reactions and open novel options for management of underlying chronic airway inflammatory diseases. Diagnosis of NERD is based on detailed clinical history confirmed by challenge with aspirin, but new diagnostic approaches are currently being developed. This review article focuses on the diagnostic approach to a patient with CRS and hypersensitivity to NSAIDs, emphasizing the importance of diagnosis for proper patient's management.

Update on aspirin desensitization for chronic rhinosinusitis with polyps in aspirin-exacerbated respiratory disease (AERD)

Aspirin-exacerbated respiratory disease (AERD) is a clinical condition which results in adverse upper and lower respiratory symptoms, particularly rhinitis, conjunctivitis, bronchospasm, and/or laryngospasm, following exposure to cyclooxygenase-1 (COX-1) inhibiting drugs, namely aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs). A provocative aspirin challenge is the gold standard for diagnosis of AERD. Aspirin desensitization and continuous aspirin therapy has been highly efficacious in those patients with suboptimal control of their disease on current available pharmacotherapy or those with other underlying conditions (i.e., cardiovascular disease) who may require frequent treatment with aspirin or NSAIDs. This review article focuses on aspirin desensitization and the management of patients with AERD with a particular emphasis on outcomes in those patients with chronic rhinosinusitis and nasal polyposis.

Clinical course of patients with aspirin-exacerbated respiratory disease: can we predict the prognosis?

AIM

This study aimed to identify prognostic factors of aspirin-exacerbated respiratory disease by comparing clinical and genetic data with the clinical course.

PATIENTS & METHODS

Patients were classified into two groups according to their response to inhalation rechallenge with lysine-aspirin after at least 1 year of regular treatment with antiasthmatic medications.

RESULTS

Forty eight patients (39.3%, group I) had negative responses, whereas 74 patients (60.7%, group II) had positive responses (n = 23) or were not rechallenged owing to persistent symptoms (n = 51). FEV₁ at diagnosis and follow-up were significantly lower in group II than in group I. The CCR3 polymorphism at -520T/G differed significantly between the two groups, whereas no difference was found in other SNPs.

CONCLUSION

Baseline FEV₁ and lower lung function after treatment were clinical factors indicating a poor prognosis of aspirin-exacerbated respiratory disease. The G allele of CCR3 -520T>G was associated with persistent bronchial hypersensitivity to aspirin.

Aspirin-exacerbated respiratory disease: characteristics and management strategies

Aspirin-exacerbated respiratory disease is a clinical entity comprising chronic rhinosinusitis with nasal polyposis, asthma and intolerance to COX-1 inhibiting drugs. The pathogenesis is not completely understood at this point, but abnormal arachidonic acid metabolism is a key feature in this syndrome. The diagnosis is confirmed only by direct drug challenge. Aspirin desensitization followed by daily aspirin therapy is a useful treatment option in these patients. In this review article are discussed the important characteristics and treatment of aspirin-exacerbated respiratory disease.

Platelet-driven leukotriene C4-mediated airway inflammation in mice is aspirin-sensitive and depends on T prostanoid receptors

Cysteinyl leukotrienes (cysLTs) are bronchoconstricting lipid mediators that amplify eosinophilic airway inflammation by incompletely understood mechanisms. We recently found that LTC4, the parent cysLT, potently activates platelets in vitro and induces airway eosinophilia in allergen-sensitized and -challenged mice by a platelet- and type 2 cysLT receptor-dependent pathway. We now demonstrate that this pathway requires production of thromboxane A2 and signaling through both hematopoietic and lung tissue-associated T prostanoid (TP) receptors. Intranasal administration of LTC4 to OVA-sensitized C57BL/6 mice markedly increased the numbers of eosinophils in the bronchoalveolar lavage fluid, while simultaneously decreasing the percentages of eosinophils in the blood by a TP receptor-dependent mechanism. LTC4 upregulated the expressions of ICAM-1 and VCAM-1 in an aspirin-sensitive and TP receptor-dependent manner. Both hematopoietic and nonhematopoietic TP receptors were essential for LTC4 to induce eosinophil recruitment. Thus, the autocrine and paracrine functions of thromboxane A2 act downstream of LTC4/type 2 cysLT receptor signaling on platelets to markedly amplify eosinophil recruitment through pulmonary vascular adhesion pathways. The findings suggest applications for TP receptor antagonists in cases of asthma with high levels of cysLT production.

Prostaglandin D₂: a dominant mediator of aspirin-exacerbated respiratory disease

BACKGROUND

Aspirin desensitization followed by high-dose aspirin therapy is routinely performed for patients with aspirin-exacerbated respiratory disease (AERD). Little is known about the contributions of mediators other than cysteinyl leukotrienes to aspirin reactions and to the therapeutic benefit of high-dose aspirin therapy.

OBJECTIVE

We investigated differences in urinary eicosanoid metabolite levels and blood eosinophil counts in patients with AERD who tolerate and those who fail aspirin desensitization and also in patients with AERD who were successfully treated with high-dose aspirin therapy.

METHODS

Twenty-nine patients with AERD were stratified into those who tolerated aspirin desensitization (group I) and those who did not (group II). Urine was analyzed for eicosanoid metabolites at baseline, during aspirin reactions, and during high-dose aspirin therapy. Blood was analyzed for cell differentials at baseline and during aspirin therapy.

RESULTS

Basal prostaglandin D2 metabolite (PGD-M; 13.6 ± 2.7 vs 7.0 ± 0.8 pmol/mg creatinine [Cr], P < .05) and thromboxane metabolite (TX-M; 1.4 ± 0.3 vs 0.9 ± 0.1 pmol/mg Cr, P < .01) levels were higher in group II than in group I. During aspirin reactions, PGD-M levels remained unchanged, whereas TX-M levels (0.7 ± 0.1 pmol/mg Cr, P = .07) tended to decrease in group I. In contrast, PGD-M levels increased dramatically in group II (61.3 ± 19.9 pmol/mg Cr, P < .05), whereas TX-M levels did not change. The decrease in FEV1 inversely correlated with basal urinary levels of both leukotriene E4 and PGD-M. Blood eosinophil and basophil levels increased and urinary PGD-M levels (2.2 ± 0.8 pmol/mg Cr, P < .001) decreased on 2 months of high-dose aspirin therapy in group I.

CONCLUSION

Failure to tolerate aspirin desensitization in a subset of patients with AERD is associated with prostaglandin D2 overproduction. The increase in blood eosinophil and basophil counts during high-dose aspirin therapy might reflect the functional consequences of decreased prostaglandin D2 release and the therapeutic benefit of aspirin.

A retrospective study of the clinical benefit from acetylsalicylic acid desensitization in patients with nasal polyposis and asthma

Background

Aspirin-exacerbated respiratory disease (AERD), also known as Samter’s triad, is a clinical syndrome which consists of aspirin (ASA) intolerance, chronic rhinosinusitis with nasal polyposis, and intrinsic bronchial asthma (Press Med 119:48-51, 1922). ASA challenge is the gold standard for diagnosing AERD (Curr Allergy Asthma 9:155-163, 2009). The practice of ASA challenge and desensitization in Canada is infrequently utilized, which may explain its omission as a viable therapeutic option in the latest Canadian clinical practice guidelines for acute and chronic rhinosinusitis (AACI 7:1-38, 2011).

Methods

This retrospective study assessed 111 patients who underwent ASA desensitization in the Allergy and Immunology clinic at St. Joseph’s Healthcare (SJHC) in London, Ontario. The mean age was 50.7 years, and 52.5% (n = 58) were male. Sixty-one percent (n = 68) claimed prior, significant reactions to ASA, and all patients had features of AERD.

Results

Seventy-three percent (n = 81) claimed symptom improvement after achieving maintenance dosing on the desensitization protocol. Of this population, 21.6% (n = 24) improved in all 3 areas of interest (sense of taste or smell, upper respiratory symptoms and lower respiratory symptoms). Twenty-six percent (n = 29) had adverse effects, mostly in the way of gastrointestinal upset, but no severe adverse events were seen.

Conclusions

ASA desensitization helps improve symptoms in patients with AERD. Further, it allows patients to tolerate additional ASA and other non-steroidal anti-inflammatories (NSAIDs) when needed for supplemental analgesia or for cardio-protection. This is of particular benefit in those who require these medications for improved quality of life, and for reduced morbidity and mortality, such as those with cardiovascular disease or chronic pain. There should be further studies conducted in Canada as well as consideration for ASA desensitization to be included in the next clinical practice guidelines.