Update on the Management of Aspirin-Exacerbated Respiratory Disease

Biologic Therapies across Nasal Polyp Subtypes

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

Allergy and Asthma Prevalence and Management Across Nasal Polyp Subtypes

Allergy and asthma prevalence vary across different subsets of chronic rhinosinusitis with nasal polyposis. In this article, the authors investigate the management of allergy and asthma within populations of patients with aspirin-exacerbated respiratory disease, allergic fungal rhinosinusitis, and central compartment atopic disease. Topical steroids, nasal rinses, and endoscopic sinus surgery are frequently employed in the management of nasal polyposis. Further, other causes of upper and lower airway inflammation like allergy and asthma should be considered in the overall treatment plan in order to optimize outcomes.

Investigation of the Relationship between Aspirin-Sensitivity and Poor Response to Medical Management in NSAIDs-exacerbated Respiratory Disease Patients with Sinonasal Polyposis

Background

NSAID-exacerbated respiratory disease (N-ERD) is a highly heterogeneous disorder with various clinical symptoms. The aspirin challenge test is a gold standard method for its diagnosis, and there are still no reliable in vitro diagnostic biomarkers yet. Oral challenge tests are time-consuming and may be associated with a risk of severe systemic reactions. This study aimed to evaluate whether patients with poor responses to medical management are more susceptible to being aspirin-sensitive.

Methods

In this cohort study, after CT scanning of all patients and subject selection, conventional medical treatment was started as follows and continued for three consecutive months: at first, saline nose wash twice per day, intranasal beclomethasone spray one puff in each nostril twice per day, montelukast 10 mg tablet once daily, a ten-day course of oral prednisolone starting with the dose of 25 mg per day and taper and discontinued thereafter. Sinonasal outcome test 22 (SNOT22) was used for the evaluation of symptom severity. Statistical analyses were performed with SPSS version 23, and data were analyzed using an independent samples T-test, paired T-test, and Receiver operating curve analysis.

Results

25 males and 53 females were enrolled in this study, with an average age of 41.56 ± 11.74 years old (18-36). Aspirin challenge test results were positive in 29 (37.2%) patients. The average SNOT22 scores before the treatment were 52.97 ± 17.73 and 47.04 ± 18.30 in aspirin-sensitive and aspirin-tolerant patients, respectively, and decreased to 27.41 ± 16.61 and 24.88 ± 16.72 in aspirin-sensitive and aspirin-tolerant patients after the treatment, respectively. There was no significant difference in SNOT22 scores between the groups.

Conclusion

The severity of symptoms before treatment and clinical improvement after treatment are not good predictors of N-ERD.

[Theories of the pathogenesis of polypous rhinosinusitis and the asthmatic triad]

Polypous rhinosinusitis (PRS) is a chronic inflammatory disease of the mucous membrane of the nasal cavity and paranasal sinuses, characterized by the formation and recurrent growth of polyps. Often, PRS is a manifestation of the most severe clinical symptom complex - the asthmatic triad (AT). AT is characterized by three main clinical manifestations: bronchial asthma (BA) itself, PRS, intolerance to acetylsalicylic acid, other nonsteroidal anti-inflammatory drugs (NSAIDs) and NA. However, not all three components of the triad are expressed equally, a variant of the dyad (BA with PRS) is possible. AT is one of the most severe variants of BA, it is more difficult to respond to conservative therapy and significantly reduces the ability of patients to work. In the world, PRS and AT are detected in 0.5-16% of the population, in Russia the number of patients is about 1.5 million people.

MATERIAL AND METHODS

The analysis of the medical literature on this problem has been carried out.

RESULTS

To date, there is no consensus on the etiology and pathogenesis of the polypous process in the nasal cavity and paranasal sinuses, therefore, many theories of the occurrence of this disease have been proposed, the main ones being: anatomical factors, osteitis, virological, bacterial, allergic, autoimmune theory and the theory of metabolic disorders of arachidonic acid. The key role in modern studies of the pathogenesis of AT is still given to the peculiarities of arachidonic acid metabolism.

CONCLUSIONS

The low effectiveness of treatment and the severity of clinical manifestations encourage scientists to further investigate the etiopathogenesis of polypous rhinosinusitis and the asthmatic triad.

Phenotypes and Endotypes in Asthma

Asthma is a broadly encompassing diagnosis of airway inflammation with significant variability in presentation and response. Advances in molecular techniques and imaging have unraveled the delicate mechanistic tapestry responsible for the underlying inflammatory pathways in asthma. The elucidation of biomarkers and cellular components specific to these inflammatory pathways allowed for the categorization of asthma from generic phenotypes to more specific mechanistic endotypes, with two prominent subgroups emerging based on the level of Type 2 inflammation present - T2 high and T2 low (or non-T2). Sophisticated modeling and cluster analyses using a combination of clinical, physiologic, and biomarker parameters have permitted the identification of subendotypes within the broader T2 umbrella. This mechanistic-driven classification schema for asthma has dramatically altered the landscape of asthma management with the discovery and approval of targeted biologic therapies and has ushered in a new era of personalized precision medicine in asthma.

Advances in the Understanding of Drug Hypersensitivity: 2012 Through 2022

Over the last decade there have been key advances in understanding mechanisms, risk, and consequences of both true immunological drug hypersensitivity and unverified drug allergy labels that have changed clinical practice. This has been facilitated by the widespread adoption of electronic health records (EHRs). The vast majority of EHR drug allergy labels are unverified and cause significant morbidity from unnecessary avoidance of optimal drug therapy. There has also been significant movement in our understanding of mechanisms of drug hypersensitivity that, in addition to advancing our understanding of the pathogenesis of immediate and delayed reactions, have guided preventive efforts, diagnostic procedures, and clinical management. More widespread adoption, including scale-up of "allergy" delabeling and appropriate management, specifically for antibiotics, opiates, radiocontrast, chemotherapeutics, biologics, and nonsteroidal anti-inflammatory medications, will be necessary to improve patient outcomes over the next decade. This will require further engagement and collaboration between primary care health care providers, allergists, and other specialists.

Overview of recent advancements in asthma management

Asthma is a common but complex heterogenous inflammatory airway disorder. Despite significant developments in our understanding of the pathophysiology and treatment of asthma, it remains a major cause of mortality and morbidity. Optimal management involves addressing modifiable risk factors, titration of inhaled pharmacotherapy in a stepwise approach and, in severe disease, consideration of biologic agents. Appreciation of the clinical characteristics of asthma and recognition of the immune pathways involved has allowed the development of phenotypic and endotypic subtypes of asthma to be better defined. This has revolutionised asthma management, allowing risk stratification of patients, targeted use of biologic agents to modify cytokine responses that drive asthma and improved patient outcomes. Patient education and engagement are critical to the management of this disease in an era of personalised medicine and a rapidly changing global environment.

Persistent Eosinophilic Inflammation in Adult Asthmatics with High Serum and Urine Levels of Leukotriene E4

Background

Cysteinyl leukotrienes (CysLTs) are key mediators for bronchoconstriction, eosinophil recruitment and mucus production in the airways of asthmatic patients. To better understand the role of CysLTs in different asthma phenotypes, we compared the levels of arachidonic acid metabolites in relation to asthma control status and phenotypes in adult asthmatics on regular anti-asthma medications.

Methods

A total of 137 adult asthmatics (47 with aspirin-exacerbated respiratory disease [AERD] and 90 asthmatics with aspirin-tolerant asthma [ATA]) and 20 healthy controls were enrolled. Arachidonic acid metabolites in serum and urine were analyzed using LC-MS/MS methods, and clinical data, including asthma control status, exhaled NO (FeNO) and lung function tests, were collected.

Results

Urine LTE₄ levels were significantly higher in AERD patients on inhaled corticosteroid-long-acting β₂- agonist plus leukotriene receptor antagonist (LTRA) treatment than in ATA patients (P=0.001). No differences were found in the serum or urine levels of 15-HETE, TXB_2, or PGF_2α. High serum LTE₄ levels were associated with lower FEV1% and uncontrolled status in AERD patients (P=0.006 and P=0.002, respectively), but not in ATA patients. Multivariate analysis demonstrated that blood eosinophil counts, FeNO levels and aspirin hypersensitivity were significant factors affecting urine LTE₄ levels.

Conclusion

Despite LTRA treatment in AERD, the LTE₄ levels remained high and showed close associations with blood eosinophilia, high FeNO levels and impaired disease control. Our real-world evidence indicates that control of asthma is not fully achieved by blocking the CysLT pathway with LTRA. Thus, introduction of treatment modalities targeting eosinophilia could be a better option for patients with high CysLTs.

Effect of TGF-β1 on eosinophils to induce cysteinyl leukotriene E4 production in aspirin-exacerbated respiratory disease

Cysteinyl leukotriene (cysLT) overproduction and eosinophil activation are hallmarks of aspirin-exacerbated respiratory disease (AERD). However, pathogenic mechanisms of AERD remain to be clarified. Here, we aimed to find the significance of transforming growth factor beta 1 (TGF-β1) in association with cysteinyl leukotriene E4 (LTE4) production, leading to eosinophil degranulation. To evaluate levels of serum TGF-β1, first cohort enrolled AERD (n = 336), ATA (n = 442) patients and healthy control subjects (HCs, n = 253). In addition, second cohort recruited AERD (n = 34) and ATA (n = 25) patients to investigate a relation between levels of serum TGF-β1 and urinary LTE4. The function of TGF-β1 in LTE4 production was further demonstrated by ex vivo (human peripheral eosinophils) or in vivo (BALB/c mice) experiment. As a result, the levels of serum TGF-β1 were significantly higher in AERD patients than in ATA patients or HCs (P = .001; respectively). Moreover, levels of serum TGF-β1 and urinary LTE4 had a positive correlation (r = 0.273, P = .037). In the presence of TGF-β1, leukotriene C4 synthase (LTC4S) expression was enhanced in peripheral eosinophils to produce LTE4, which sequentially induced eosinophil degranulation via the p38 pathway. When mice were treated with TGF-β1, significantly induced eosinophilia with increased LTE4 production in the lung tissues were noted. These findings suggest that higher levels of TGF-β1 in AERD patients may contribute to LTE4 production via enhancing LTC4S expression which induces eosinophil degranulation, accelerating airway inflammation.

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

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

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.

Associations between TMEM196 polymorphisms and NSAID-exacerbated respiratory disease in asthma

BACKGROUND

We previously found differences in the minor allele frequency (MAF) of single-nucleotide polymorphisms (SNPs) in transmembrane protein 196 (TMEM196) between 995 patients with aspirin-tolerant asthma (ATA) and 141 asthmatic patients with NSAID-exacerbated respiratory disease (NERD). In this study, we statistically analyzed the distributions of the genotypes and haplotypes of these SNPs to determine the exact association between TMEM196 genetic variants and the risk for NERD.

MATERIALS AND METHODS

Lewontin's D' and r values were used to measure linkage disequilibrium between the biallelic loci having MAFs more than 0.05, and haplotypes were inferred using the PHASE algorithm (version 2.0). The genotype distribution was analyzed by logistic regression models using age of onset, smoking status (nonsmoker=0, ex-smoker=1, smoker=2), and BMI as covariates. Regression analysis of the association between SNPs and the risk of NERD was analyzed using SPSS version 12.0 and PLINK version 1.9.

RESULTS

The MAF of rs9886152 C>T was significantly lower in NERD than in ATA [24.8 vs. 34.0%, odds ratio=0.64 (0.48-0.85), P=2.07×10, Pcorr=0.048]. The rate of the rs9886152 C>T minor allele was significantly lower in NERD than in ATA [44.0 vs. 56.4% in the codominant model, P=0.002, Pcorr=0.049, odds ratio=0.64 (0.48-0.85)]. An additional three SNPs (rs9639334 A>G, rs9638765 A>G, and rs2097811 G>A) showed similar associations with the risk of NERD. NERD patients had lower frequencies of the rs9639334 A>G minor allele (51.1 vs. 64.4%, P=0.002, Pcorr=0.043), rs9638765 A>G (49.7 vs. 64.2%, P=0.001, Pcorr=0.017), and rs2097811 G>A (51.1 vs. 64.5%, P=0.002, Pcorr=0.04) compared with ATA patients. Patients homozygous for the minor alleles of the four SNPs showed significantly less of an aspirin-induced decrease in forced expiratory volume in one second compared with those homozygous for the common alleles (P=0.003-0.012).

CONCLUSION

The minor alleles of the four SNPs in TMEM196 may exert a protective effect against the development of NERD and may be useful genetic markers to predict the risk of NERD.

Surfactant protein D alleviates eosinophil-mediated airway inflammation and remodeling in patients with aspirin-exacerbated respiratory disease

BACKGROUND

Surfactant protein D (SPD) is a member of the collectin family that lines the airway epithelial cells with host defense. However, the role of SPD in the pathogenesis of aspirin-exacerbated respiratory disease (AERD) is still unclear.

METHODS

The serum SPD level was measured in patients with AERD (n = 336), those with aspirin-tolerant asthma (ATA, n = 442), and healthy controls (HC, n = 104). Polymorphisms of SFTPD in the study subjects were analyzed. The effect of LTE4 on SPD production through eosinophil infiltration was investigated in BALB/c mice. The protective function of SPD against eosinophils inducing inflammation and remodeling was assessed in vitro/vivo. The potential efficacy of nintedanib against airway remodeling through the production of SPD was evaluated.

RESULTS

The serum SPD level was significantly lower (P < .001) in AERD compared with ATA patients, and negatively correlated with fall in FEV₁ (%) after lysine-aspirin bronchoprovocation test and/or the urinary LTE4 level. In addition, polymorphism of SFTPD at rs721917 was significantly different in the study subjects (odds ratio, 1.310; 95% confidence intervals, 2.124-3.446; P = .002). LTE4-exposed mice showed an increased eosinophil count with a decreased SPD level in bronchoalveolar lavage fluid. Eosinophils increased α-smooth muscle actin expression in airway epithelial cells, which was attenuated by SPD treatment. Furthermore, nintedanib protected the airway epithelial cells against eosinophils by enhancing the production of SPD.

CONCLUSION

The decreased level of SPD in AERD was associated with airway inflammation/remodeling under the eosinophilic condition, suggesting that modulation of SPD may provide a potential benefit in AERD.

Which Factors Associated With Activated Eosinophils Contribute to the Pathogenesis of Aspirin-Exacerbated Respiratory Disease?

Eosinophils have long been recognized as a central effector cell in the lungs of asthmatic patients. They contribute to airway inflammation and remodeling through releasing several molecules such as cytokines, granule proteins, lipid mediators and extracellular traps/vesicles. Repeated evidence reveals that intense eosinophil infiltration in upper and lower airway mucosae contributes to the pathogenesis of aspirin-exacerbated respiratory disease (AERD). Persistent eosinophilia is found to be associated with type 2 immune responses, cysteinyl leukotriene overproduction and eosinophil-epithelium interactions. This review highlights recent findings about key mechanisms of eosinophil activation in the airway inflammation of AERD. In addition, current biologics (targeting type 2 immune responses) were suggested to control eosinophilic inflammation for AERD patients.

Epithelial folliculin enhances airway inflammation in aspirin-exacerbated respiratory disease

BACKGROUND

Clinical features of aspirin-exacerbated respiratory disease (AERD) are characterized by overproduction of cysteinyl leukotrienes (LT) and eosinophil activation, in which epithelial cells contribute to eosinophilic airway inflammation. Folliculin (FLCN) helps maintain the integrity of epithelial barrier, but little is known about FLCN in AERD.

OBJECTIVE

We investigated the role of FLCN in the pathogenic mechanisms of AERD.

METHODS

We recruited 178 subjects with AERD, 276 subjects with aspirin-tolerant asthma (ATA) and 71 normal healthy controls (NC) at Ajou Medical Center. Levels of FLCN and interleukin (IL)-8 in sera and supernatants were measured by ELISA. Peripheral blood eosinophils isolated from asthmatic patients were cocultured with human airway epithelial cells (HAECs) pretreated with LTE₄ , dexamethasone and montelukast. The intracellular expressions of FLCN, tight (TJ) (occludins, claudin-1) and adherens (AJ) junctions (E-cadherin) were analysed by Western blotting. shRNA was used to down-regulate FLCN (shFLCN) in HAECs.

RESULTS

Serum FLCN levels were significantly higher in AERD group than in ATA and NC groups (all P < 0.001). The cut-off value of 56.6 pg/mL was used to define the high FLCN phenotype (highFLCN). Asthmatic patients with highFLCN were associated with increased airway hyperresponsiveness to methacholine (P = 0.015). The serum FLCN level could discriminate AERD group from NC group with 82% sensitivity (AUC = 0.793, P < 0.001). When HAECs were exposed to LTE₄ , FLCN release was increased significantly (P < 0.05), which were amplified along with disruption of TJ and AJ expressions when HAECs were cocultured with eosinophils and LTE₄ (all P < 0.05); these effects were suppressed by dexamethasone and montelukast. FLCN knockdown reduced IL-8 release and occludin expression from shFLCN HAECs.

CONCLUSIONS

Our findings suggest that high LT and airway eosinophilia increased FLCN release from HAECs, which enhance epithelial activation and disruption. Modulation of FLCN may be a potential target for AERD.

Aspirin-exacerbated respiratory disease: an update

PURPOSE OF REVIEW

The pathophysiology of aspirin-exacerbated respiratory disease (AERD) is not fully understood and diagnostic methods and so far, treatments for AERD have not been standardized. We summarize recent research into the pathological mechanisms of AERD, diagnostic methods, and treatments for AERD patients.

RECENT FINDINGS

In AERD pathophysiology, not only the reduced expression of E prostanoid 2 but also the dysfunction of its pathway could be involved. Moreover, eosinophils of AERD patients could be directly activated by aspirin to produce prostaglandin D2. Platelet activations are well known to be involved in AERD; however, plasma markers do not change during aspirin challenge tests. Additionally, novel genetic polymorphisms, such as P2RY12 and dipeptidyl peptidase 10 gene, and epigenetic predispositions of AERD were found. In AERD diagnosis, bronchial and nasal aspirin challenges have been applied in addition to oral challenge. Serum periostin has been suggested as a potential biomarker for AERD. Apart from standard pharmacological treatment and aspirin desensitization, biologics, including omalizumab and mepolizumab, as well as CRTH2 antagonists have been suggested as promising therapies for AERD treatment.

SUMMARY

AERD is usually associated with severe asthma phenotypes. AERD pathophysiology mainly involves the dysregulation of eicosanoid metabolisms, activations of effector cells, which could be influenced by genetic/epigenetic factors. Understanding the pathophysiology of AERD is key to improve the diagnostic methods and proper management of AERD patients.

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.

Therapeutic Effect of Omalizumab in Severe Asthma: A Real-World Study in Korea

Purpose

Omalizumab, an anti-immunoglobulin E (IgE) monoclonal antibody, has proved to be effective for the treatment of severe asthma. However, there is no direct evidence of effectiveness of omalizumab in Korean patients with severe asthma. We sought to evaluate the real-world effectiveness of omalizumab in Korean adult patients suffering from severe asthma and to identify predictors of favorable response.

Methods

A retrospective analysis of electrical medical records was performed on severe allergic asthmatic patients with omalizumab treatment group (OT group) for more than 6 months between March 2008 and February 2016. Propensity score matching was applied to define the standardized treatment control group (STC group) treated without omalizumab. Asthma-related outcomes were compared between the 2 groups, and analyzed before and after omalizumab use in the OT group. Responders to treatment were defined as patients showing >50% reduction in asthma exacerbations and/or systemic steroid requirement during the outcome period.

Results

One hundred twenty-four patients with severe asthma (62 in the OT group; 62 in the STC group) were enrolled in the study. Proportion of patients having the reduction of asthma exacerbation (53.2% vs 35.5%, P=0.015) and the rate of responders (67.7% vs 41.9%, P=0.007) were significantly higher in the OT group than in the STC group. Significant reductions were noted in asthma exacerbation (P=0.006), hospitalization (P=0.009), hospitalization days (P=0.006), systemic corticosteroid requirements (P=0.027), and sputum eosinophil count (P=0.031) in OT group compared with STC group. There were no significant differences in changes of forced expiratory volume in the 1 second (FEV1) levels between the 2 groups. No predictors of responders were found for omalizumab treatment.

Conclusions

Omalizumab can reduce exacerbations/hospitalization/systemic steroid burst in Korean adult patients with severe asthma.

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.

Dietary Fatty Acid Modification for the Treatment of Aspirin-Exacerbated Respiratory Disease: A Prospective Pilot Trial

BACKGROUND

The high levels of eicosanoid production and the clinical efficacy of leukotriene-modifying pharmacotherapies for patients with aspirin-exacerbated respiratory disease (AERD) suggest that other interventions targeting arachidonic acid dysregulation may also improve disease control.

OBJECTIVE

To assess the utility of a high omega-3/low omega-6 diet for the treatment of AERD.

METHODS

Prospective, nonblinded dietary intervention in 10 adult patients with AERD at Brigham and Women's Hospital in Boston, MA. The primary objective was for subjects to reduce dietary omega-6 fatty acid consumption to less than 4 g/d and increase omega-3 intake to more than 3 g/d. The primary outcome was change in urinary leukotriene E₄, with changes in other eicosanoids, platelet activation, lung function, and patient-reported questionnaires also assessed.

RESULTS

Of the 10 subjects who screened for the study, all 10 completed the dietary intervention. Urinary leukotriene E₄ decreased by 0.17 ng/mg (95% CI, -0.29 to -0.04; P = .02) and tetranor prostaglandin D-M decreased by 0.66 ng/mg creatinine (95% CI, -1.21 to -0.11; P = .02). There was a 15.1-point reduction in the 22-item Sino-Nasal Outcome Test score (95% CI, -24.3 to -6.0; P = .01), a 0.27-point reduction in the 7-item Asthma Control Questionnaire score (95% CI, -0.52 to -0.03; P = .03), and no change in FEV₁ % predicted (P = .92) or forced vital capacity % predicted (P = .74). All patients lost some weight over the 2-week intervention period, and there were no diet-associated adverse events.

CONCLUSIONS

A high omega-3/low omega-6 diet may be an appropriate adjunct treatment option for patients with AERD.

Cofactors and comorbidities in patients with aspirin/NSAID hypersensitivity

Hypersensitivity reactions to aspirin and other NSAIDs occur in individuals genetically predisposed and exhibit different clinical manifestations, especially respiratory, cutaneous, and generalised. Five different phenotypes define distinct clinical pictures: aspirin-exacerbated respiratory disease, aspirin/NSAID cutaneous disease, NSAID-induced urticaria, angio-oedema and anaphylaxis, single NSAID reactions, and delayed reactions. They are observed more frequently in middle-aged women, and in atopic individuals. While ASA/NSAID hypersensitivity shares comorbidities with asthma, chronic rhinosinusitis, nasal polyposis, chronic urticaria and angio-oedema, ASA and other NSAIDs can also be cofactors for other clinically relevant conditions, especially food-dependent exercise-induced anaphylaxis, angio-oedema induced by angiotensin-converting enzyme inhibitors, and oral mite anaphylaxis. Awareness on these relationships is required for the correct diagnosis, classification, and treatment of affected patients.

Potential Biomarkers for NSAID-Exacerbated Respiratory Disease

Asthma is a common chronic disease with several variant phenotypes and endotypes. NSAID-exacerbated respiratory disease (NERD) is one such endotype characterized by asthma, chronic rhinosinusitis (CRS) with nasal polyps, and hypersensitivity to aspirin/cyclooxygenase-1 inhibitors. NERD is more associated with severe asthma than other asthma phenotypes. Regarding diagnosis, aspirin challenge tests via the oral or bronchial route are a standard diagnostic method; reliable in vitro diagnostic tests are not available. Recent studies have reported various biomarkers of phenotype, diagnosis, and prognosis. In this review, we summarized the known potential biomarkers of NERD that are distinct from those of aspirin-tolerant asthma. We also provided an overview of the different NERD subgroups.

Drug Hypersensitivity and Desensitizations: Mechanisms and New Approaches

Drug hypersensitivity reactions (HSRs) are increasing in the 21st Century with the ever expanding availability of new therapeutic agents. Patients with cancer, chronic inflammatory diseases, cystic fibrosis, or diabetes can become allergic to their first line therapy after repeated exposures or through cross reactivity with environmental allergens. Avoidance of the offending allergenic drug may impact disease management, quality of life, and life expectancy. Precision medicine provides new tools for the understanding and management of hypersensitivity reactions (HSRs), as well as a personalized treatment approach for IgE (Immunoglobuline E) and non-IgE mediated HSRs with drug desensitization (DS). DS induces a temporary hyporesponsive state by incremental escalation of sub-optimal doses of the offending drug. In vitro models have shown evidence that IgE desensitization is an antigen-specific process which blocks calcium flux, impacts antigen/IgE/FcεRI complex internalization and prevents the acute and late phase reactions as well as mast cell mediator release. Through a "bench to bedside" approach, in vitro desensitization models help elucidate the molecular pathways involved in DS, providing new insights to improved desensitization protocols for all patients. The aim of this review is to summarize up to date information on the drug HSRs, the IgE mediated mechanisms of desensitization, and their clinical applications.

Association of interleukin-25 levels with development of aspirin induced respiratory diseases

BACKGROUND

Aspirin-exacerbated respiratory diseases (AERD) are caused by ingestion of non-steroidal anti-inflammatory drugs and are characterized by acute bronchospasms and marked infiltration of eosinophils, the latter being attributable to altered synthesis of cysteinyl leukotrienes (LT) and prostaglandins (PG). Recently, the innate Th2 response is revealed to induce eosinophil infiltration in allergic inflammation, however the role of the innate Th2 response has not been studies in AERD. Thus, we evaluated the relationship between the innate Th2 cytokines including IL-25, thymic stromal lymphopoietin (TSLP) and IL-33 and the development of AERD.

METHODS AND MATERIALS

Plasma IL-25, IL-33, and TSLP levels were measured before and after aspirin challenge in subjects with AERD (n = 25) and aspirin-tolerant asthma (ATA, n = 25) by enzyme-linked immunosorbent assay (ELISA). Pre and post-aspirin challenge levels of LTC4 and PGD2 were measured using ELISA.

RESULTS

Basal plasma IL-25 levels were significantly higher in AERD group than in normal controls and in ATA group (p = 0.025 and 0.031, respectively). IL-33 and TSLP levels were comparable in the AERD and ATA groups. After the aspirin challenge, the IL-25 levels were markedly decreased in the ATA group (p = 0.024), while not changed in the AERD group. The post-challenge IL-25 levels of all asthmatic subjects were significantly correlated with aspirin challenge - induced declines in FEV1 (r = 0.357, p = 0.011), but not with basal and post challenge LTC4 and PGD2 levels.

CONCLUSIONS

IL-25 is associated with bronchospasm after aspirin challenge, possibly via mechanisms other than altered LTC4 and PGD2 production.

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.

Aspirin-exacerbated respiratory disease and current treatment modalities

Aspirin-exacerbated respiratory disease (AERD) refers to the combination of asthma, chronic rhinosinusitis with nasal polyposis, and acute upper and lower respiratory tract reactions to the ingestion of aspirin (acetylsalicylic acid, ASA) and other cyclooxygenase-1 inhibiting non-steroidal anti-inflammatory drugs. AERD affects 0.3-0.9 % of the general population. AERD generally occurs due to abnormalities in mediators and expression of arachidonic acid biosynthesis. Local IgE responses to staphylococcal enterotoxins may also be responsible for eosinophilic activation in the nasal polyp tissues of AERD patients. Clinical features of AERD include the onset of nasal congestion with anosmia, progressing to chronic pansinusitis and nasal polyps that regrow rapidly after surgery. Aspirin desensitization, Leukotriene-modifying agents, biologic agents, management of asthma, chronic rhinosinusitis, and nasal polyposis are recommended as treatment modalities. Immunotherapy is prescribed only to those AERD patients who experience clear seasonal or perennial allergy symptoms in addition to the symptoms attributable to chronic nasal polyposis. There are also investigational and dietary therapies. In this review, the important aspects of AERD will be presented, along with a literature survey.