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

Aspirin hypersensitivity diagnostic index (AHDI): In vitro test for diagnosing of N-ERD based on urinary 15-oxo-ETE and LTE4 excretion

BACKGROUND

15-oxo-eicosatetraenoic acid (15-oxo-ETE), is a product of arachidonic acid (AA) metabolism in the 15-lipoxygenase-1 (15-LOX-1) pathway. 15-oxo-ETE was overproduced in the nasal polyps of patients with nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD). In this study we investigated the systemic biosynthesis of 15-oxo-ETE and leukotriene E4 (LTE4) and assessed their diagnostic value to identify patients with N-ERD.

METHODS

The study included 64 patients with N-ERD, 59 asthmatics who tolerated aspirin well (ATA), and 51 healthy controls. A thorough clinical characteristics of asthmatics included computed tomography of paranasal sinuses. Plasma and urinary 15-oxo-ETE levels, and urinary LTE4 excretion were measured using high-performance liquid chromatography and tandem mass spectrometry. Repeatability and precision of the measurements were tested.

RESULTS

Plasma 15-oxo-ETE levels were the highest in N-ERD (p < .001). A receiver operator characteristic (ROC) revealed that 15-oxo-ETE had certain sensitivity (64.06% in plasma, or 88.24% in urine) for N-ERD discrimination, while the specificity was rather limited. Modeling of variables allowed to construct the Aspirin Hypersensitivity Diagnostic Index (AHDI) based on urinary LTE4-to-15-oxo-ETE excretion corrected for sex and the Lund-Mackay score of chronic rhinosinusitis. AHDI outperformed single measurements in discrimination of N-ERD among asthmatics with an area under ROC curve of 0.889, sensitivity of 81.97%, specificity of 87.23%, and accuracy of 86.87%.

CONCLUSIONS

We confirmed 15-oxo-ETE as a second to cysteinyl leukotrienes biomarker of N-ERD. An index based on these eicosanoids corrected for sex and Lund-Mackay score has a similar diagnostic value as gold standard oral aspirin challenge in the studied group of patients with asthma.

Updates on the Natural History and Clinical Characteristics of NSAID-ERD

Nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (NSAID-ERD) is a distinct clinical syndrome characterized by nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity, asthma, and nasal polyposis. Its diagnosis is challenging owing to variable presentations and a lack of simple tests, leading to diagnostic delays. Recent research has revealed its genetic predispositions, environmental triggers, and associations with atopy and second-hand tobacco smoke exposure or smoking cessation. Despite its severity, diagnostic awareness remains low, leading to the delay in effective management. Therapeutically, NSAID-ERD necessitates multidisciplinary approaches, often combining surgical interventions with medical management, including aspirin desensitization and biologic agents. However, predictive biomarkers for treatment response remain elusive. Understanding the underlying mechanisms driving NSAID-ERD pathogenesis and identifying reliable biomarkers are crucial for enhancing diagnostic accuracy and refining targeted therapeutic strategies for this debilitating condition. This review aims to provide a thorough understanding of NSAID-ERD, covering its history, clinical features, epidemiology, diagnosis, systemic and molecular biomarkers, available treatment options, and avenues for future research.

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.

Lower serum 15-HETE level predicts nasal ILC2 accumulation during COX-1 inhibition in AERD

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is associated with high levels of cysteinyl leukotrienes, prostaglandin D2, and low levels of prostaglandin E2. Further, 15-hydroxyeicosatetraenoic acid (15-HETE) levels may have predictive value in therapeutic outcomes of aspirin desensitization. Accumulation of nasal group 2 innate lymphoid cells (ILC2s) has been demonstrated during COX-1 inhibition in AERD, although the relationships between tissue ILC2 accumulation, reaction symptom severity, and novel lipid biomarkers are unknown.

OBJECTIVE

We sought to determine whether novel lipid mediators are predictive of nasal ILC2 accumulation and symptom scores during COX-1 inhibitor challenge in patients with AERD.

METHODS

Blood and nasal scraping samples from patients with AERD were collected at baseline and COX-1 inhibitor reaction and then processed for flow cytometry for nasal ILC2s and serum for lipidomic analysis.

RESULTS

Eight patients with AERD who were undergoing aspirin desensitization were recruited. Of the 161 eicosanoids tested, 42 serum mediators were detected. Baseline levels of 15-HETE were negatively correlated with the change in numbers of airway ILC2s (r = -0.6667; P = .0428). Docosahexaenoic acid epoxygenase metabolite 19,20-dihydroxy-4Z,7Z,10Z,13Z,16Z-docosapentaenoic acid (19,20-diHDPA) was positively correlated with both changes in airway ILC2s (r = 0.7143; P = .0305) and clinical symptom scores (r = 0.5000; P = .0081).

CONCLUSION

Low levels of baseline 15-HETE predicted a greater accumulation of airway ILC2s in patients with AERD who were receiving COX-1 inhibition. Further, increases in the cytochrome P pathway metabolite 19,20-dihydroxy-4Z,7Z,10Z,13Z,16Z-docosapentaenoic acid (19,20-diHDPA) were associated with increased symptoms and nasal ILC2 accumulation. Future studies to assess how these mediators might control ILC2s may improve the understanding of AERD pathogenesis.

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.

Plasma and rectal mucosal oxylipin levels during aspirin and eicosapentaenoic acid treatment in the seAFOod polyp prevention trial

BACKGROUND

Aspirin and eicosapentaenoic acid (EPA) have colorectal polyp prevention activity, alone and in combination. This study measured levels of plasma and rectal mucosal oxylipins in participants of the seAFOod 2 × 2 factorial, randomised, placebo-controlled trial, who received aspirin 300 mg daily and EPA 2000 mg free fatty acid, alone and in combination, for 12 months.

METHODS

Resolvin (Rv) E1, 15-epi-lipoxin (LX) A₄ and respective precursors 18-HEPE and 15-HETE (with chiral separation) were measured by ultra-high performance liquid chromatography-tandem mass spectrometry in plasma taken at baseline, 6 months and 12 months, as well as rectal mucosa obtained at trial exit colonoscopy at 12 months, in 401 trial participants.

RESULTS

Despite detection of S- and R- enantiomers of 18-HEPE and 15-HETE in ng/ml concentrations, RvE1 or 15‑epi-LXA₄ were not detected above a limit of detection of 20 pg/ml in plasma or rectal mucosa, even in individuals randomised to both aspirin and EPA. We have confirmed in a large clinical trial cohort that prolonged (12 months) treatment with EPA is associated with increased plasma 18-HEPE concentrations (median [inter-quartile range] total 18-HEPE 0.51 [0.21-1.95] ng/ml at baseline versus 0.95 [0.46-4.06] ng/ml at 6 months [P<0.0001] in those randomised to EPA alone), which correlate strongly with respective rectal mucosal 18-HEPE levels (r = 0.82; P<0.001), but which do not predict polyp prevention efficacy by EPA or aspirin.

CONCLUSION

Analysis of seAFOod trial plasma and rectal mucosal samples has not provided evidence of synthesis of the EPA-derived specialised pro-resolving mediator RvE1 or aspirin-trigged lipoxin 15‑epi-LXA₄. We cannot rule out degradation of individual oxylipins during sample collection and storage but readily measurable precursor oxylipins argues against widespread degradation.

The role of oxylipins in NSAID-exacerbated respiratory disease (N-ERD)

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) is characterized by nasal polyp formation, adult-onset asthma, and hypersensitivity to all cyclooxygenase-1 (COX-1) inhibitors. Oxygenated lipids are collectively known as oxylipins and are polyunsaturated fatty acids (PUFA) oxidation products. The most extensively researched oxylipins being the eicosanoids formed from arachidonic acid (AA). There are four major classes of eicosanoids including leukotrienes, prostaglandins, thromboxanes, and lipoxins. In N-ERD, the underlying inflammatory process of the upper and lower respiratory systems begins and occurs independently of NSAID consumption and is due to the overproduction of cysteinyl leukotrienes. Leukotriene mediators all induce edema, bronchoconstriction, and airway mucous secretion. Thromboxane A2 is a potent bronchoconstrictor and induces endothelial adhesion molecule expression. Elevated Prostaglandin D2 metabolites lead to vasoconstriction, additionally impaired up-regulation of prostaglandin E2 leads to symptoms seen in N-ERD as it is essential for maintaining homeostasis of inflammatory responses in the airway and has bronchoprotective and anti-inflammatory effects. A characteristic feature of N-ERD is diminished lipoxin levels, this decreased capacity to form endogenous mediators with anti-inflammatory properties could facilitate local inflammatory response and expose bronchial smooth muscle to relatively unopposed actions of broncho-constricting substances. Treatment options, such as leukotriene modifying agents, aspirin desensitization, biologic agents and ESS, appear to influence eicosanoid pathways, however more studies need to be done to further understand the role of oxylipins. Besides AA-derived eicosanoids, other oxylipins may also pay a role but have not been sufficiently studied. Identifying pathogenic N-ERD mechanism is likely to define more effective treatment targets.

Comprehensive Analysis of Nasal Polyps Reveals a More Pronounced Type 2 Transcriptomic Profile of Epithelial Cells and Mast Cells in Aspirin-Exacerbated Respiratory Disease

Chronic rhinosinusitis with nasal polyps is affecting up to 3% of Western populations. About 10% of patients with nasal polyps also suffer from asthma and intolerance to aspirin, a syndrome called aspirin-exacerbated respiratory disease. Although eosinophilic inflammation is predominant in polyps of both diseases, phenotypic differences in the tissue-derived microenvironment, elucidating disease-specific characteristics, have not yet been identified. We sought to obtain detailed information about phenotypic and transcriptional differences in epithelial and immune cells in polyps of aspirin-tolerant and intolerant patients. Cytokine profiles in nasal secretions and serum of patients suffering from aspirin-exacerbated respiratory disease (n = 10) or chronic rhinosinusitis with nasal polyps (n = 9) were assessed using a multiplex mesoscale discovery assay. After enrichment for immune cell subsets by flow cytometry, we performed transcriptomic profiling by employing single-cell RNA sequencing. Aspirin-intolerant patients displayed significantly elevated IL-5 and CCL17 levels in nasal secretions corresponding to a more pronounced eosinophilic type 2 inflammation. Transcriptomic profiling revealed that epithelial and mast cells not only complement one another in terms of gene expression associated with the 15-lipoxygenase pathway but also show a clear type 2-associated inflammatory phenotype as identified by the upregulation of POSTN, CCL26, and IL13 in patients with aspirin-exacerbated respiratory disease. Interestingly, we also observed cellular stress responses indicated by an increase of MTRNR2L12, MTRNR2L8, and NEAT1 across all immune cell subsets in this disease entity. In conclusion, our findings support the hypothesis that epithelial and mast cells act in concert as potential drivers of the pathogenesis of the aspirin-exacerbated respiratory disease.

Effector functions of Th17 cells are regulated by IL-35 and TGF-β in visceral leishmaniasis

Visceral leishmaniasis (VL) is a debilitating human pathogenesis in which the body's immune functions are severely compromised. Various subsets of T cells, including Th17 cells are important regulators of immune responses observed in various pathologies. The role of Th17 cells and its correlation with immuno-regulatory cytokines are however not well understood in human VL. Herein we studied how IL-17 is associated with the progression of Leishmania donovani infection using murine model of VL. We found induction of a strong IL-17 response at the early phase of infection which progressively reduced to basal level during chronic VL. The mechanistic study of this behavior was found to be linked with the role of regulatory T cells (CD4⁺ CD25⁺ T cells) that suppresses the proliferation of the Th17 cell population. Moreover, TGF-β and IL-35 derived from CD4⁺ CD25⁺ T cells are the key mediators for the downregulation of IL-17 during chronic VL. Thus, this study points to an antagonistic effect of Tregs and Th17 cells that can be used for designing better therapeutic and preventive strategies against leishmaniasis.

Biomarkers for predicting response to long-term high dose aspirin therapy in aspirin-exacerbated respiratory disease

INTRODUCTION

Aspirin-exacerbated respiratory disease (AERD) is a phenotype of asthma characterized by eosinophilic inflammation in the airways, mast cell activation, cysteinyl leukotriene overproduction, and acute respiratory reactions on exposure to cyclooxygenase-1 inhibitors. Aspirin desensitization followed by daily high-dose aspirin therapy is a safe and effective treatment option for the majority of patients with AERD. However, there is still some percentage of the population who do not derive benefits from daily aspirin use.

METHODS

Based on the current literature, the biomarkers, which might predict aspirin treatment outcomes in AERD patients, were evaluated.

RESULTS AND CONCLUSIONS

Patients with severe symptoms of chronic rhinosinusitis, type 2 asthma based on blood eosinophilia, non-neutrophilic inflammatory phenotype based on sputum cells, as well as high plasma level of 15-hydroxyeicosatetraenoic acid (15-HETE) are potentially good responders to long term high-dose aspirin therapy. Additionally, high expression of the hydroxyprostaglandin dehydrogenase gene, HPGD encoding prostaglandin-degrading enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH) and low expression of the proteoglycan 2 gene, PRG2 encoding constituent of the eosinophil granule in sputum cells might serve as a predictor of good response to aspirin therapy. Variations in the expression of cysteinyl leukotriene receptor 1 in the airways could additionally influence the response to long-term aspirin therapy. Arachidonic acid metabolites levels via the 5-lipoxygenase as well as via the cyclooxygenase pathways in induced sputum supernatant do not change during high dose long-term aspirin therapy and do not influence outcomes of aspirin treatment.

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.

Clinical evaluation and diagnosis of aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease (AERD) is a condition composed of chronic rhinosinusitis with nasal polyposis and asthma that is defined by respiratory hypersensitivity reactions to the cyclooxygenase 1-inhibitory effects of nonsteroidal anti-inflammatory drugs. It is diagnosed in 5% to 15% of patients with asthma and is even more common in those with comorbid nasal polyposis. Diagnosis is confirmed after an aspirin challenge procedure, yet many patients present with all components and can reliably be diagnosed by history. Patients with AERD commonly experience severe uncontrolled nasal polyposis and require multispecialty evaluation to properly stage and treat this condition. The presence of nasal polyposis plays a large component in the diminished quality of life in patients with AERD. In the last decade, multiple new therapeutic areas have been approved for type 2 airway diseases, offering patients with AERD many more options for control. This makes an early and accurate diagnosis of AERD important in the care of the larger population of type 2 airway diseases.

Aspirin Actions in Treatment of NSAID-Exacerbated Respiratory Disease

Non-steroidal Anti-inflammatory drugs (NSAID)-exacerbated respiratory disease (N-ERD) is characterized by nasal polyposis, chronic rhinosinusitis, adult-onset asthma and hypersensitive reactions to cyclooxygenase-1 (COX-1) inhibitors. Among the available treatments for this disease, a combination of endoscopic sinus surgery followed by aspirin desensitization and aspirin maintenance therapy has been an effective approach. Studies have shown that long-term aspirin maintenance therapy can reduce the rate of nasal polyp recurrence in patients with N-ERD. However, the exact mechanism by which aspirin can both trigger and suppress airway disease in N-ERD remains poorly understood. In this review, we summarize current knowledge of aspirin effects in N-ERD, cardiovascular disease, and cancer, and consider potential mechanistic pathways accounting for the effects of aspirin in N-ERD.

Biomarkers for predicting response to aspirin therapy in aspirin-exacerbated respiratory disease

Background

Aspirin desensitization followed by daily aspirin use is an effective treatment for aspirin‐exacerbated respiratory disease (AERD).

Objective

To assess clinical features as well as genetic, immune, cytological and biochemical biomarkers that might predict a positive response to high‐dose aspirin therapy in AERD.

Methods

We enrolled 34 AERD patients with severe asthma who underwent aspirin desensitization followed by 52‐week aspirin treatment (650 mg/d). At baseline and at 52 weeks, clinical assessment was performed; phenotypes based on induced sputum cells were identified; eicosanoid, cytokine and chemokine levels in induced sputum supernatant were determined; and induced sputum expression of 94 genes was assessed. Responders to high‐dose aspirin were defined as patients with improvement in 5‐item Asthma Control Questionnaire score, 22‐item Sino‐Nasal Outcome Test (SNOT‐22) score and forced expiratory volume in 1 second at 52 weeks.

Results

There were 28 responders (82%). Positive baseline predictors of response included female sex (p = .002), higher SNOT‐22 score (p = .03), higher blood eosinophil count (p = .01), lower neutrophil percentage in induced sputum (p = .003), higher expression of the hydroxyprostaglandin dehydrogenase gene, HPGD (p = .004) and lower expression of the proteoglycan 2 gene, PRG2 (p = .01). The best prediction model included Asthma Control Test and SNOT‐22 scores, blood eosinophils and total serum immunoglobulin E. Responders showed a marked decrease in sputum eosinophils but no changes in eicosanoid levels.

Conclusions and Clinical Relevance

Female sex, high blood eosinophil count, low sputum neutrophil percentage, severe nasal symptoms, high HPGD expression and low PRG2 expression may predict a positive response to long‐term high‐dose aspirin therapy in patients with AERD.

Targeting eosinophils in respiratory diseases: Biological axis, emerging therapeutics and treatment modalities

Eosinophils are bi-lobed, multi-functional innate immune cells with diverse cell surface receptors that regulate local immune and inflammatory responses. Several inflammatory and infectious diseases are triggered with their build up in the blood and tissues. The mobilization of eosinophils into the lungs is regulated by a cascade of processes guided by Th2 cytokine generating T-cells. Recruitment of eosinophils essentially leads to a characteristic immune response followed by airway hyperresponsiveness and remodeling, which are hallmarks of chronic respiratory diseases. By analysing the dynamic interactions of eosinophils with their extracellular environment, which also involve signaling molecules and tissues, various therapies have been invented and developed to target respiratory diseases. Having entered clinical testing, several eosinophil targeting therapeutic agents have shown much promise and have further bridged the gap between theory and practice. Moreover, researchers now have a clearer understanding of the roles and mechanisms of eosinophils. These factors have successfully assisted molecular biologists to block specific pathways in the growth, migration and activation of eosinophils. The primary purpose of this review is to provide an overview of the eosinophil biology with a special emphasis on potential pharmacotherapeutic targets. The review also summarizes promising eosinophil-targeting agents, along with their mechanisms and rationale for use, including those in developmental pipeline, in clinical trials, or approved for other respiratory disorders.

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.

Aspirin-Exacerbated Respiratory Disease: Association Between Patient-Reported Sinus and Asthma Morbidity

BACKGROUND

The association between sinonasal and pulmonary symptoms in aspirin-exacerbated respiratory disease is not fully established.

OBJECTIVE

To characterize sinonasal and asthma symptomatology, and to determine whether reported sinonasal symptoms predict asthma severity.

METHODS

Prospectively collected data from an aspirin-exacerbated respiratory disease registry cohort were included from 2013 to 2018. Sinonasal symptomatology measured by Sino-Nasal Outcomes Test (SNOT) 22-item total scores was used as the predictor variable, with Asthma Control Test (ACT) scores and percent predicted FEV₁ (FEV₁% predicted) as primary outcomes. All instances of paired data on the same date were used. ACT score was also evaluated with FEV₁% predicted as the outcome. Mixed effects regression was completed.

RESULTS

From 1065 aspirin-exacerbated respiratory disease registry subjects (mean age, 48.1 ± 12.8 years; 68.0% females, 29.8% males), mean SNOT-22 score was 42.3 ± 24.12 (n = 1307 observations from 869 subjects), mean ACT score was 19.4 ± 5.2 (n = 1511 observations from 931 subjects), and mean FEV₁% predicted was 82.8 ± 19.6 (n = 777 observations from 307 subjects). SNOT-22 score significantly predicted ACT scores (P < .0001, 1185 paired observations from 845 subjects) and FEV₁% predicted (P = .018, 485 observations from 246 subjects). Any 10-point increase in SNOT-22 score was associated with a 0.87-point decrease in ACT score and a 0.75% decrease in FEV₁% predicted. Any 1-point increase in ACT score was associated with a 1.0% increase in FEV₁% predicted (P < .0001, 616 observations from 269 subjects). The most severe SNOT-22 symptoms were sense of smell/taste and blockage/congestion of nose.

CONCLUSIONS

SNOT-22 scores significantly predict ACT scores and FEV₁% predicted, and ACT scores significantly predict FEV₁% predicted. This study demonstrates an association between patient-reported rhinosinusitis and asthma symptom severity and subjective and objective measures of asthma severity.

Analysis of serum polyunsaturated fatty acid metabolites in allergic bronchopulmonary aspergillosis

BACKGROUND

The importance of lipid mediators in allergic diseases has been long recognized, whereas little is known about their role in allergic bronchopulmonary aspergillosis (ABPA). We investigated whether lipid mediators are associated with ABPA.

METHODS

We recruited 12 ABPA patients, 23 asthma patients and 12 healthy control in our study. Serum of 11 ABPA patients were collected before and following treatment. 36 polyunsaturated fatty acid metabolites were measured in serum samples by using liquid chromatography-mass spectrometry. This study was approved by the Ethics Committee of the First Affiliated Hospital of Guangzhou Medical University, with ethics number GYFYY-2016-73.

RESULTS

Levels of arachidonic acid (AA), 15(S)-hydroxyeicosatetraenoic acid (HETE), 12(S)-HETE, 8(S)-HETE, 5(S)-HETE, LTB₄, PGB₂, 12(S)-hydroxyeicosapentaenoic acid (HEPE), 12-hydro-xyheptadecatrienoic acid (HHTrE) were significantly higher in ABPA patients than that in HC groups. Compared with asthma group, ABPA group expressed lower levels of 15(S)-hy-droperoxyeicosatetraenoic acid (HPETE), 5(S)-HPETE, 13(S)-hydroperoxyoctadecadienoic acid (HPODE) and 9(S)-HPODE. In APBA patients, AA level was positively correlated with serumtotal IgE (tIgE). The levels of 12(S)-HPETE, 15(S)-HEPE and 12(S)-HEPE correlated with Asp-ergillus fumigatus specific IgE(A. fumigatus sIgE) positively. Peripheral blood eosinophilia correlated with high levels of 12(S)-HETE and 15(S)-HETE. In addition, the serum levels of15(S)-HETE and 12(S)-HETE in ABPA subjects both declined with the decrease of tIgE, A. fumigatus sIgE and sIgG concentrations after treatment.

CONCLUSIONS

We present data regarding the role of polyunsaturated fatty acid metabolites in APBA for the first time. Most of the tested metabolites increased in ABPA when co-mpared with healthy controls and 15(S)-HETE and 12(S)-HETE may play a role in the pat-hogenesis of ABPA. These findings can provide new ideas for diagnosis, therapy and mon-itor of ABPA.

Meta-analysis Exploring Sinopulmonary Outcomes of Aspirin Desensitization in Aspirin-Exacerbated Respiratory Disease

OBJECTIVE

The objective of this study is to explore the sinopulmonary outcomes of aspirin desensitization through a systematic review and meta-analysis.

DATA SOURCES

Embase and OVID Medline databases.

REVIEW METHODS

A systematic review of published articles on outcomes following aspirin desensitization in any language for relevant articles was performed in February 2019. Outcomes included sinonasal quality-of-life assessment, sense-of-smell scores, FEV-1 (forced expiratory volume in 1 second), and medication/steroid use.

RESULTS

Thirteen studies met the inclusion criteria out of 6055 articles screened. Aspirin desensitization resulted in significant improvement in FEV-1 and reduction in asthma medication/steroid use (P < .05). There was no significant improvement in the sinonasal quality of life of patients who underwent aspirin desensitization (P = .098).

CONCLUSION

Aspirin desensitization appears to be effective in improving pulmonary outcomes and should be considered in the treatment of patients with aspirin-exacerbated respiratory disease. However, good-quality studies are still needed to determine the ideal protocol tailored to individual patients.

Activation of the 15-lipoxygenase pathway in aspirin-exacerbated respiratory disease

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is characterized by asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), and an intolerance of medications that inhibit cyclooxygenase-1. Patients with AERD have more severe upper and lower respiratory tract disease than do aspirin-tolerant patients with CRSwNP. A dysregulation in arachidonic acid metabolism is thought to contribute to the enhanced sinonasal inflammation in AERD.

OBJECTIVE

Our aim was to utilize an unbiased approach investigating arachidonic acid metabolic pathways in AERD.

METHODS

Single-cell RNA sequencing (10× Genomics, Pleasanton, Calif) was utilized to compare the transcriptional profile of nasal polyp (NP) cells from patients with AERD and patients with CRSwNP and map differences in the expression of select genes among identified cell types. Findings were confirmed by traditional real-time PCR. Lipid mediators in sinonasal tissue were measured by mass spectrometry. Localization of various proteins within NPs was assessed by immunofluorescence.

RESULTS

The gene encoding for 15-lipooxygenase (15-LO), ALOX15, was significantly elevated in NPs of patients with AERD compared to NPs of patients with CRSwNP (P < .05) or controls (P < .001). ALOX15 was predominantly expressed by epithelial cells. Expression levels significantly correlated with radiographic sinus disease severity (r = 0.56; P < .001) and were associated with asthma. The level of 15-oxo-eicosatetraenoic acid (15-Oxo-ETE), a downstream product of 15-LO, was significantly elevated in NPs from patients with CRSwNP (27.93 pg/mg of tissue) and NPs from patients with AERD (61.03 pg/mg of tissue) compared to inferior turbinate tissue from controls (7.17 pg/mg of tissue [P < .001]). Hydroxyprostaglandin dehydrogenase, an enzyme required for 15-Oxo-ETE synthesis, was predominantly expressed in mast cells and localized near 15-LO⁺ epithelium in NPs from patients with AERD.

CONCLUSIONS

Epithelial and mast cell interactions, leading to the synthesis of 15-Oxo-ETE, may contribute to the dysregulation of arachidonic acid metabolism via the 15-LO pathway and to the enhanced sinonasal disease severity observed in AERD.

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.

Heterogeneity of NSAID-Exacerbated Respiratory Disease: has the time come for subphenotyping?

PURPOSE OF REVIEW

NSAID-Exacerbated Disease (N-ERD) is a chronic eosinophilic inflammatory disorder of the respiratory tract occurring in patients with asthma and/or rhinosinusitis with nasal polyps, whose symptoms are exacerbated by NSAIDs. The purpose of this review is to provide an update on clinical characteristics, pathophysiology, and management of N-ERD, and to emphasize heterogeneity of this syndrome.

RECENT FINDINGS

Growing evidence indicates that N-ERD, which has been considered a separate asthma phenotype, is heterogenous, and can be divided in several subphenotypes varying in clinical characteristics. Pathophysiology of N-ERD is complex and extends beyond abnormalities in the arachidonic acid metabolism. Heterogeneity of pathophysiological mechanisms underlying development of airway inflammation seems to be associated with variability in response to both anti-inflammatory and disease-specific treatments (e.g., with aspirin after desensitization).

SUMMARY

Progress in understanding of the pathophysiology of N-ERD leads to discovery and validation of new biomarkers facilitating diagnosis and predicting the response to treatment of the chronic inflammation underlying upper (CRSwNP) and lower airway (asthma) symptoms. Better characterization of the immunophysiopathological heterogeneity of N-ERD (identification of endotypes) may allow more personalized, endotype-driven approach to treatment in the future.

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.

Depression symptoms and quality of life among individuals with aspirin-exacerbated respiratory disease

OBJECTIVE

Patients with aspirin-exacerbated respiratory disease (AERD) have high disease burden due to the severity of asthma and sinonasal symptoms. There is limited research on the psychological well-being and subjective experiences of patients with AERD. This study examined levels of depression symptoms, asthma-related quality of life and asthma control among AERD patients.

METHODS

Thirty-two adults with AERD and 39 patients without AERD (asthma-only) were recruited from outpatient asthma/allergy clinics. The sample was largely comprised of ethnic minority, inner-city patients who ranged in age from 19 to 84 years old. Participants completed the Beck Depression Inventory (BDI), the Mini Asthma Quality of Life Questionnaire (Mini AQLQ), a self-report rating of asthma severity and spirometry testing. Asthma control and severity were determined following national guidelines.

RESULTS

AERD patients reported lower levels of depression symptoms (p = 0.049), better overall asthma-related quality of life (p < 0.001), and perceived their asthma to be less severe (p = 0.01) compared to asthma-only patients. However, clinician ratings of asthma severity were more severe for AERD than asthma-only patients (p = 0.006). No significant differences were found between the groups on asthma controller medications or oral corticosteroid bursts for asthma.

CONCLUSIONS

AERD patients may be resilient given their low levels of depression symptoms and positive views of asthma-related impairment despite higher clinician-rated asthma severity. The adult onset nature of asthma in AERD might be a protective factor on mental health. Future studies should explore mechanisms linking AERD and positive psychological health outcomes and subjective perception of asthma.

Sinus Surgery Is Associated with a Decrease in Aspirin-Induced Reaction Severity in Patients with Aspirin Exacerbated Respiratory Disease

BACKGROUND

Nasal polyps influence the burden of aspirin-exacerbated respiratory disease (AERD) by contributing to eicosanoid production. AERD is diagnosed through graded aspirin challenges. It is not known how sinus surgery affects aspirin challenge outcomes.

OBJECTIVE

To investigate the effects of endoscopic sinus surgery (ESS) on aspirin-induced reaction severity and on the levels of eicosanoids associated with these reactions.

METHODS

Twenty-eight patients with AERD were challenged with aspirin before and 3 to 4 weeks after ESS. Respiratory parameters and plasma and urine levels of eicosanoids were compared before and after challenges.

RESULTS

Before ESS, AERD diagnosis was confirmed in all study patients by aspirin challenges that resulted in hypersensitivity reactions. After ESS, reactions to aspirin were less severe in all patients and 12 of 28 patients (43%, P < .001) had no detectable reaction. A lack of clinical reaction to aspirin was associated with lower peripheral blood eosinophilia (0.1 K/μL [interquartile range (IQR) 0.1-0.3] vs 0.4 K/μL [IQR 0.2-0.8]; P = .006), lower urinary leukotriene E₄ levels after aspirin challenge (98 pg/mg creatinine [IQR 61-239] vs 459 pg/mg creatinine [IQR 141-1344]; P = .02), and lower plasma prostaglandin D₂ to prostaglandin E₂ ratio (0 [±0] vs 0.43 [±0.2]; P = .03), compared with those who reacted.

CONCLUSIONS

Sinus surgery results in decreased aspirin sensitivity and a decrease in several plasma and urine eicosanoid levels in patients with AERD. Diagnostic aspirin challenges should be offered to patients with suspected AERD before ESS to increase diagnostic accuracy. Patients with established AERD could undergo aspirin desensitizations after ESS as the severity of their aspirin-induced hypersensitivity reactions lessens.

An overview of the biologic effects of omega-6 oxylipins in humans

Oxylipins are lipid mediators produced from polyunsaturated fatty acid (PUFA) metabolism, and are thought to be a molecular explanation for the diverse biological effects of PUFAs. Like PUFAs, oxylipins are distinguished by their omega-6 (n6) or omega-3 (n3) chemistry. We review the use of n6 oxylipins as biomarkers of disease and their use in diagnosis and risk assessment. We show cases where oxylipins derived from linoleate (LA) or arachidonate (AA) produced by the activities of lipoxygenase, cyclooxygenase, epoxygenase, ω/ω-1 hydroxylase, and autooxidation are useful as biomarkers or risk markers. HODEs, KODEs, EpOMEs, DiHOMEs, and other metabolites of LA as well as prostanoids, HETEs, KETEs, EpETrEs, and DiHETrEs, and other metabolites of AA were useful for understanding the different signaling environments in conditions from traumatic brain injury, to major coronary events, dyslipidemia, sepsis, and more. We next evaluate interventions that alter the concentrations of n6 oxylipins in plasma. We note the utility and response of each plasma fraction, and the generally increasing utility from the non-esterified, to the esterified, to the lipoprotein fractions. Finally, we review the effects which are specifically related to n6 oxylipins and most likely to be beneficial. Both n6 and n3 oxylipins work together in an exceedingly complex matrix to produce physiological effects. This overview should provide future investigators with important perspectives for the emerging utility of n6 oxylipins as products of n6 PUFAs in human health.

Prediagnostic Serum Levels of Fatty Acid Metabolites and Risk of Ovarian Cancer in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial

BACKGROUND

Evidence suggests that inflammation increases risk for ovarian cancer. Aspirin has been shown to decrease ovarian cancer risk, though the mechanism is unknown. Studies of inflammatory markers, lipid molecules such as arachidonic acid, linoleic acid, and alpha-linoleic acid metabolites, and development of ovarian cancer are essential to understand the potential mechanisms.

METHODS

We conducted a nested case-control study (157 cases/156 matched controls) within the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Unconditional logistic regression was used to estimate the association between prediagnostic serum levels of 31 arachidonic acid/linoleic acid/alpha-linoleic acid metabolites and risk of ovarian cancer.

RESULTS

Five of the 31 arachidonic acid/linoleic acid/alpha-linoleic acid (free fatty acids) metabolites were positively associated with ovarian cancer risk: 8-HETE [tertile 3 vs. 1: OR 2.53 (95% confidence interval [CI] 1.18-5.39), P _trend 0.02], 12,13-DHOME [2.49 (1.29-4.81), 0.01], 13-HODE [2.47 (1.32-4.60), 0.005], 9-HODE [1.97 (1.06-3.68), 0.03], 9,12,13-THOME [2.25 (1.20-4.21), 0.01]. In analyses by subtype, heterogeneity was suggested for 8-HETE [serous OR (95% CI): 2.53 (1.18-5.39) vs. nonserous OR (95% CI): 1.15 (0.56-2.36), P _het 0.1] and 12,13-EpOME [1.95 (0.90-4.22) vs. 0.82 (0.39-1.73), 0.05].

CONCLUSIONS

Women with increased levels of five fatty acid metabolites (8-HETE, 12,13-DHOME, 13-HODE, 9-HODE, and 9,12,13-THOME) were at increased risk of developing ovarian cancer in the ensuing decade. All five metabolites are derived from either arachidonic acid (8-HETE) or linoleic acid (12,13-DHOME, 13-HODE, 9-HODE, 9,12,13-THOME) via metabolism through the LOX/cytochrome P450 pathway.

IMPACT

The identification of these risk-related fatty acid metabolites provides mechanistic insights into the etiology of ovarian cancer and indicates the direction for future research.

The Journal of Allergy and Clinical Immunology: In Practice 2017 Year in Review

An impressive number of clinically impactful studies and reviews were published in The Journal of Allergy and Clinical Immunology: In Practice in 2017. As a service to our readers, the editors provide this Year in Review article to highlight and contextualize the advances published over the past year. We include information from articles on asthma, allergic rhinitis, rhinosinusitis, immunotherapy, atopic dermatitis, contact dermatitis, food allergy, anaphylaxis, drug hypersensitivity, urticarial/angioedema, eosinophilic disorders, and immunodeficiency. Within each topic, epidemiologic findings are presented, relevant aspects of prevention are described, and diagnostic and therapeutic advances are enumerated. Treatments discussed include behavioral therapy, allergen avoidance therapy, positive and negative effects of pharmacologic therapy, and various forms of immunologic and desensitization management. We hope this review will help readers consolidate and use this extensive and practical knowledge for the benefit of patients.