Subphenotypes of nonsteroidal antiinflammatory disease-exacerbated respiratory disease identified by latent class analysis

Inflammatory Cytokines in Middle Ear Effusion of Patients With Asthma, Chronic Rhinosinusitis With Nasal Polyps With or Without NSAID Intolerance

OBJECTIVE

To measure the inflammatory cytokines of middle ear effusion (MEE) in otitis media (OM) associated with asthma and chronic rhinosinusitis with nasal polyps (CRSwNP) with or without nonsteroidal anti-inflammatory drug (NSAID) sensitivity to strengthen our assumption that OM is part of the same inflammatory entity. The potential individual differences between MEE inflammatory cytokines could be used in clinical practice for more individual characterization of the inflammation.

STUDY DESIGN

Case-control study.

SETTING

Tertiary referral center.

PATIENTS

Convenience sample of 24 case patients with otitis media with effusion (OME) or chronic otitis media (COM), asthma, and CRSwNP, 14 of whom had NSAID intolerance, and 8 controls with OME but no history of asthma, CRSwNP, or NSAID intolerance.

INTERVENTION

Diagnostic.

MAIN OUTCOME AND MEASURE

Inflammatory cytokines including interleukins (IL)-4, IL-5, IL-6, IL-13, and interferon gamma (IFN-γ) in middle ear effusion.

RESULTS

The MEE mass fractions of IL-5 (p = 0.003) and IFN-γ (p = 0.048) were higher among our case patients with OME/COM than among the controls. For IL-4 and IL-13, the mass fractions were also higher among the case patients than the controls, but this difference was not statistically significant (p = 0.199 and p = 0.617, respectively). We found no difference between the IL-6 mass fractions of the groups. We found notable heterogeneity in individual patients' cytokine levels.

CONCLUSIONS

According to our findings, OM, when present, should be considered part of the respiratory inflammatory process associated with asthma and CRSwNP. The individual differences in MEE cytokine levels could be useful as biomarkers.

Biomarkers of immediate drug hypersensitivity

Immediate drug hypersensitivity reactions (IDHRs) are a burden for patients and the health systems. This problem increases when taking into account that only a small proportion of patients initially labelled as allergic are finally confirmed after an allergological workup. The diverse nature of drugs involved will imply different interactions with the immunological system. Therefore, IDHRs can be produced by a wide array of mechanisms mediated by the drug interaction with specific antibodies or directly on effector target cells. These heterogeneous mechanisms imply an enhanced complexity for an accurate diagnosis and the identification of the phenotype and endotype at early stages of the reaction is of vital importance. Currently, several endophenotypic categories (type I IgE/non-IgE, cytokine release, Mast-related G-protein coupled receptor X2 (MRGPRX2) or Cyclooxygenase-1 (COX-1) inhibition and their associated biomarkers have been proposed. A precise knowledge of endotypes will permit to discriminate patients within the same phenotype, which is crucial in order to personalise diagnosis, future treatment and prevention to improve the patient's quality of life.

Distinct eicosanoid patterns in severe recalcitrant nasal polyposis

BACKGROUND

Although altered eicosanoid levels are related to disease severity in chronic rhinosinusitis with nasal polyps (CRSwNP), identifying patients prone to recurrent nasal polyps (NPs) is still difficult. We investigated levels of nasally secreted eicosanoids before and after NP surgery in patients with or without NP recurrence (NPR) and explored potential endotypes based on pre-surgical eicosanoid levels.

METHODS

Levels of leukotriene (LT) E4 , LTB4 , prostaglandin (PG) D2 , PGE2 and 15(S) hydroxyeicosatetraenoic acid (15[S]-HETE) were measured in nasal secretions with specific immunoassays at pre-surgery (n = 38) and 6 and 12 months post-surgery (n = 35), with NPR identified endoscopically. Pre- and post-surgical levels were compared between patients with and without NPR. Eicosanoid patterns among patients were explored with cluster analysis and evaluated with clinical parameters.

RESULTS

Patients with recurrent NPs had pronounced pre-surgical levels of nasal 15(S)-HETE, PGD2 and LTE4 . From pre-surgery to 12 months post-surgery, NPR was associated with significant decreases of 15(S)-HETE and PGD2 relative to non-recurrence, whereas levels of LTE4 decreased at 6 months but increased again at 12 months. Clustering revealed three potential endotypes. Clusters 1 and 3 featured high and low eicosanoid levels, respectively. Cluster 2 had higher levels of LTE4 and PGD2 , lower levels of PGE2 and LTB4 , and more cases of recurrent NPs and previous NP surgeries.

CONCLUSION

Elevated nasal LTE4 12 months post-surgery in NP recurrent subjects suggests that postoperative LTE4 measurements may indicate rapid NP regrowth. A distinct nasal eicosanoid profile may be used for the identification of the most severe recalcitrant patients in need of targeted immunomodulatory therapies.

Long-term clinical outcomes of aspirin-exacerbated respiratory disease: Real-world data from an adult asthma cohort

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is a phenotype of severe asthma, but its disease course has not been well documented compared with that of aspirin-tolerant asthma (ATA).

OBJECTIVES

This study aimed to investigate the long-term clinical outcomes between AERD and ATA.

METHODS

AERD patients were identified by the diagnostic code and positive bronchoprovocation test in a real-world database. Longitudinal changes in lung function, blood eosinophil/neutrophil counts, and annual numbers of severe asthma exacerbations (AEx) were compared between the AERD and the ATA groups. Within a year after baseline, two or more severe AEx events indicated severe AERD, whereas less than two AEx events indicated nonsevere AERD.

RESULTS

Among asthmatics, 353 had AERD in which 166 and 187 patients had severe and nonsevere AERD, respectively, and 717 had ATA. AERD patients had significantly lower FEV1%, higher blood neutrophil counts, and higher sputum eosinophils (%) (all p < .05) as well as higher levels of urinary LTE4 and serum periostin, and lower levels of serum myeloperoxidase and surfactant protein D (all p < .01) than those with ATA. In a 10-year follow-up, the severe AERD group maintained lower FEV1% with more severe AEs than the nonsevere AERD group.

CONCLUSION AND CLINICAL RELEVANCE

We demonstrated that AERD patients presented poorer long-term clinical outcomes than ATA patients in real-world data analyses.

Non‐eosinophilic asthma in nonsteroidal anti‐inflammatory drug exacerbated respiratory disease

Background

The cellular inflammatory pattern of nonsteroidal anti‐inflammatory drug–exacerbated respiratory disease (N‐ERD) is heterogeneous. However, data on the heterogeneity of non‐eosinophilic asthma (NEA) with aspirin hypersensitivity are scanty. By examination of N‐ERD patients based on clinical data and eicosanoid biomarkers we aimed to identify NEA endotypes potentially guiding clinical management.

Methods

Induced sputum was collected from patients with N‐ERD. Sixty six patients (49.6% of 133 N‐ERD) with NEA were included in the hierarchical cluster analysis based on clinical and laboratory data. The quality of clustering was evaluated using internal cluster validation with different indices and a practical decision tree was proposed to simplify stratification of patients.

Results

The most frequent NEA pattern was paucigranulocytic (PGA; 75.8%), remaining was neutrophilic asthma (NA; 24.2%). Four clusters were identified. Cluster #3 included the highest number of NEA patients (37.9%) with severe asthma and PGA pattern (96.0%). Cluster #1 (24.2%) included severe only asthma, with a higher prevalence of NA (50%). Cluster #2 (25.8%) comprised well‐controlled mild or severe asthma (PGA; 76.5%). Cluster #4 contained only 12.1% patients with well‐controlled moderate asthma (PGA; 62.5%). Sputum prostaglandin D₂ levels distinguished cluster #1 from the remaining clusters with an area under the curve of 0.94.

Conclusions

Among identified four NEA subtypes, clusters #3 and #1 represented N‐ERD patients with severe asthma but a different inflammatory signatures. All the clusters were discriminated by sputum PGD₂ levels, asthma severity, and age of patients. The heterogeneity of non‐eosinophilic N‐ERD suggests a need for novel targeted interventions.

What happens to basophils and tryptase, LXA4 and CysLTs during aspirin desensitization?

INTRODUCTION

Aspirin desensitization (AD) is an effective treatment in patients with non-steroidal anti-inflammatory drugs (NSAID)-exacerbated respiratory disease (NERD) by providing inhibitory effect on symptoms and polyp recurrence. However, limited data is available on how AD works. We aimed to study comprehensively the mechanisms underlying AD by examining basophil activation (CD203c upregulation), mediator-releases of tryptase, CysLT, and LXA₄, and LTB₄ receptor expression for the first 3 months of AD.

METHODS

The study was conducted in patients with NERD who underwent AD (group 1: n = 23), patients with NERD who received no desensitization (group 2: n = 22), and healthy volunteers (group 3, n = 13). All participants provided blood samples for flow cytometry studies (CD203c and LTB₄ receptor), and mediator releases (CysLT, LXA_4, and tryptase) for the relevant time points determined.

RESULTS

All baseline parameters of CD203c and LTB₄ receptor expressions, tryptase, CysLT, and LXA₄ releases were similar in each group (p > 0.05). In group 1, CD203c started to be upregulated at the time of reactions during AD, and continued to be high for 3 months when compared to controls. All other study parameters were comparable with baseline and at the other time points in each group (p > 0.05).

CONCLUSION

Although basophils are active during the first 3 months of AD, no releases of CysLT, tryptase or LXA₄ exist. Therefore, our results suggest that despite active basophils, inhibition of mediators can at least partly explain underlying the mechanism in the first three months of AD.

Association of ATP8B3 gene polymorphisms with aspirin-exacerbated respiratory disease in asthmatics

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD), an asthma phenotype, often presents with severe manifestations and it remains widely underdiagnosed because of insufficient awareness of the relationship between the ingestion of nonsteroidal anti-inflammatory drugs, including acetylsalicylic acid (ASA), and asthma exacerbation. Our previous genome-wide association study demonstrated an association between a single nucleotide polymorphism (SNP) of the ATP8B3 gene and the risk of AERD. This study examined AERD-related SNPs of the ATP8B3 gene in a large population.

METHODS

Twenty-five SNPs of ATP8B3 were genotyped with the GoldenGate assay using VeraCode microbeads in 141 asthmatics with AERD and 995 Aspirin-tolerant asthma (ATA). The genotype distribution was analyzed using logistic regression models. The declines in forced expiratory volume in 1 second (FEV1)following an ASA challenge were compared among the genotypes and haplotypes using a type III generalized linear model.

RESULTS

The minor allele frequencies (MAFs) of rs10421558 A>G in the 5'UTR and rs10403288 G>A in the intron were significantly lower in the AERD than the ATA [34.0% vs. 43.8%, OR = 0.66 (0.62-0.92), Pcorr = 0.03 and 28.4% vs. 35.4%, OR = 0.62 (0.59-0.89), Pcorr = 0.016, respectively]. BL1ht5 was significantly higher in the AERD [7.6% vs. 1.6%, OR = 12.23 (0.2-0.51), P = 4.7 × 10 -4 , Pcorr = 0.001]. Among them, rs10421558 A>G and BL1ht5 were associated with the percent decline in FEV1 on the oral ASA challenge test.

CONCLUSION

The minor allele of rs10421558 A>G in the 5'UTR may protect against the development of AERD via the increased production of ATP8B3.

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

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

Effects of non-steroidal anti-inflammatory drugs and other eicosanoid pathway modifiers on antiviral and allergic responses: EAACI task force on eicosanoids consensus report in times of COVID-19

Non‐steroidal anti‐inflammatory drugs (NSAIDs) and other eicosanoid pathway modifiers are among the most ubiquitously used medications in the general population. Their broad anti‐inflammatory, antipyretic, and analgesic effects are applied against symptoms of respiratory infections, including SARS‐CoV‐2, as well as in other acute and chronic inflammatory diseases that often coexist with allergy and asthma. However, the current pandemic of COVID‐19 also revealed the gaps in our understanding of their mechanism of action, selectivity, and interactions not only during viral infections and inflammation, but also in asthma exacerbations, uncontrolled allergic inflammation, and NSAIDs‐exacerbated respiratory disease (NERD). In this context, the consensus report summarizes currently available knowledge, novel discoveries, and controversies regarding the use of NSAIDs in COVID‐19, and the role of NSAIDs in asthma and viral asthma exacerbations. We also describe here novel mechanisms of action of leukotriene receptor antagonists (LTRAs), outline how to predict responses to LTRA therapy and discuss a potential role of LTRA therapy in COVID‐19 treatment. Moreover, we discuss interactions of novel T2 biologicals and other eicosanoid pathway modifiers on the horizon, such as prostaglandin D2 antagonists and cannabinoids, with eicosanoid pathways, in context of viral infections and exacerbations of asthma and allergic diseases. Finally, we identify and summarize the major knowledge gaps and unmet needs in current eicosanoid research.

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.

Pharmacogenomics of Hypersensitivity to Non-steroidal Anti-inflammatory Drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are extensively prescribed in daily clinical practice. NSAIDs are the main cause of drug hypersensitivity reactions all over the world. The inhibition of cyclooxygenase enzymes by NSAIDs can perpetuate arachidonic acid metabolism, shunting to the 5-lipoxygenase pathway and its downstream inflammatory process. Clinical phenotypes of NSAID hypersensitivity are diverse and can be classified into cross-reactive or selective responses. Efforts have been made to understand pathogenic mechanisms, in which, genetic and epigenetic backgrounds are implicated in various processes of NSAID-induced hypersensitivity reactions. Although there were some similarities among patients, several genetic polymorphisms are distinct in those exhibiting respiratory or cutaneous symptoms. Moreover, the expression levels, as well as the methylation status of genes related to immune responses were demonstrated to be involved in NSAID-induced hypersensitivity reactions. There is still a lack of data on delayed type reactions. Further studies with a larger sample size, which integrate different genetic pathways, can help overcome current limitations of gen etic/epigenetic studies, and provide valuable information on NSAID hypersensitivity reactions.

Eicosanoids and Eosinophilic Inflammation of Airways in Stable COPD

Purpose

Lipid mediators, particularly eicosanoids, are associated with airway inflammation, especially with the eosinophilic influx. This study aimed to measure lipid mediators and cells in induced sputum, that could possibly reflect the inflammatory process in the bronchial tree of COPD subjects.

Patients and Methods

Eighty patients diagnosed with COPD and 37 healthy controls participated in the study. Induced sputum samples were ascertained for differential cell count and induced sputum supernatant concentrations of selected eicosanoids by the means of gas chromatography/mass spectrometry and high-performance liquid chromatography/tandem mass spectrometry.

Results

Increased sputum eosinophilia was associated with higher concentrations of selected proinflammatory eicosanoids. In COPD subjects prostaglandin D₂ and 11-dehydro-thromboxane B₂ correlated negatively with airway obstruction measured by FEV₁ and FEV₁/FVC values. COPD subjects with disease exacerbations during past 12 months had significantly higher concentrations of prostaglandin D₂, 12-oxo-eicosatetraenoic acid and 5-oxo-eicosatetraenoic acid.

Conclusion

Stable COPD is often associated with eosinophil influx in the lower airways and elevated concentrations of eicosanoids that is reflected by some disease characteristics.

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.

Platelet-Adherent Leukocytes Associated With Cutaneous Cross-Reactive Hypersensitivity to Nonsteroidal Anti-Inflammatory Drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most highly consumed drugs worldwide and the main triggers of drug hypersensitivity reactions. The most frequent reaction, named cross-reactive NSAID-hypersensitivity, is due to the pharmacological activity of these drugs by blocking the cyclooxygenase-1 enzyme. Such inhibition leads to cysteinyl-leukotriene synthesis, mainly LTE4, which are responsible for the reaction. Although the complete molecular picture of the underlying mechanisms remains elusive, the participation of platelet-adherent leukocytes (CD61⁺) and integrins have been described for NSAID-exacerbated respiratory disease (NERD). However, there is a lack of information concerning NSAID-induced urticaria/angioedema (NIUA), by far the most frequent clinical phenotype. Here we have evaluated the potential role of CD61⁺ leukocytes and integrins (CD18, CD11a, CD11b, and CD11c) in patients with NIUA, and included the other two phenotypes with cutaneous involvement, NSAID-exacerbated cutaneous disease (NECD) and blended reactions (simultaneous skin and airways involvement). A group NSAID-tolerant individuals was also included. During the acute phase of the reaction, the three clinical phenotypes showed increased frequencies of CD61⁺ neutrophils, eosinophils, and monocytes compared to controls, which correlated with urinary LTE4 levels. However, no correlation was found between these variables at basal state. Furthermore, increased expressions of CD18 and CD11a were found in the three CD61⁺ leukocytes subsets in NIUA, NECD and blended reactions during the acute phase when compared with CD61^-leukocyte subpopulations. During the acute phase, CD61⁺ neutrophils, eosinophils and monocytes showed increased CD18 and CD11a expression when compared with CD61⁺ leukocytes at basal state. No differences were found when comparing controls and CD61⁺ leukocytes at basal state. Our results support the participation of platelet-adherent leukocytes and integrins in cutaneous cross-hypersensitivity to NSAIDs and provide a link between these cells and arachidonic acid metabolism. Our findings also suggest that these reactions do not involve a systemic imbalance in the frequency of CD61⁺ cells/integrin expression or levels of LTE4, which represents a substantial difference to NERD. Although further studies are needed, our results shed light on the molecular basis of cutaneous cross-reactive NSAID-hypersensitivity, providing potential targets for therapy through the inhibition of platelet-leukocyte interactions.

Adult-onset eosinophilic airway diseases

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

Advances and recent developments in asthma in 2020

In this review, we discuss recent publications on asthma and review the studies that have reported on the different aspects of the prevalence, risk factors and prevention, mechanisms, diagnosis, and treatment of asthma. Many risk and protective factors and molecular mechanisms are involved in the development of asthma. Emerging concepts and challenges in implementing the exposome paradigm and its application in allergic diseases and asthma are reviewed, including genetic and epigenetic factors, microbial dysbiosis, and environmental exposure, particularly to indoor and outdoor substances. The most relevant experimental studies further advancing the understanding of molecular and immune mechanisms with potential new targets for the development of therapeutics are discussed. A reliable diagnosis of asthma, disease endotyping, and monitoring its severity are of great importance in the management of asthma. Correct evaluation and management of asthma comorbidity/multimorbidity, including interaction with asthma phenotypes and its value for the precision medicine approach and validation of predictive biomarkers, are further detailed. Novel approaches and strategies in asthma treatment linked to mechanisms and endotypes of asthma, particularly biologicals, are critically appraised. Finally, due to the recent pandemics and its impact on patient management, we discuss the challenges, relationships, and molecular mechanisms between asthma, allergies, SARS-CoV-2, and COVID-19.

Inflammatory heterogeneity in aspirin-exacerbated respiratory disease

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is a mechanistically distinct subtype of chronic rhinosinusitis with nasal polyps (CRSwNP). Although frequently associated with type 2 inflammation, literature characterizing the milieu of inflammatory cytokines and lipid mediators in AERD has been conflicting.

OBJECTIVE

We sought to identify differences in the upper airway inflammatory signature between CRSwNP and AERD and determine whether endotypic subtypes of AERD may exist.

METHODS

Levels of 7 cytokines representative of type 1, type 2, and type 3 inflammation, and 21 lipid mediators were measured in nasal mucus from 109 patients with CRSwNP, 30 patients with AERD, and 64 non-CRS controls. Differences in inflammatory mediators were identified between groups, and patterns of inflammation among patients with AERD were determined by hierarchical cluster analysis.

RESULTS

AERD could be distinguished from CRSwNP by profound elevations in IL-5, IL-6, IL-13, and IFN-γ; however, significant heterogeneity existed between patients. Hierarchical cluster analysis identified 3 inflammatory subendotypes of AERD characterized by (1) low inflammatory burden, (2) high type 2 cytokines, and (3) comparatively low type 2 cytokines and high levels of type 1 and type 3 cytokines. Several lipid mediators were associated with asthma and sinonasal disease severity; however, lipid mediators showed less variability than cytokines.

CONCLUSIONS

AERD is associated with elevations in type 2 cytokines (IL-5 and IL-13) and the type 1 cytokine, IFN-γ. Among patients with AERD, the inflammatory signature is heterogeneous, supporting subendotypes of the disease. Variability in AERD immune signatures should be further clarified because this may predict clinical response to biologic medications that target type 2 inflammation.

Subphenotypes of nonsteroidal antiinflammatory disease-exacerbated respiratory disease identified by latent class analysis

BACKGROUND

Induced sputum (IS) allows to measure mediators of asthmatic inflammation in bronchial secretions. NSAID-exacerbated respiratory disease (NERD) is recognized as a distinct asthma phenotype, usually with a severe course, eosinophilic airway inflammation, and increased production of pro-inflammatory eicosanoids. A more insightful analysis of NERD patients has shown this phenotype to be nonhomogeneous.

OBJECTIVE

We aimed to identify possible subphenotypes in a cohort of NERD patients with the means of latent class analysis (LCA).

METHODS

A total of 95 asthma patients with aspirin hypersensitivity underwent sputum induction. High-performance liquid chromatography or gas chromatography coupled with mass spectrometry was used to profile eicosanoids in induced sputum supernatant (ISS). Sixteen variables covering clinical characteristics, IS inflammatory cells, and eicosanoids were considered in the LCA.

RESULTS

Three classes (subphenotypes) were distinguished within the NERD cohort. Class 1 subjects had mild-to-moderate asthma, an almost equal distribution of inflammatory cell patterns, the lowest concentrations of eicosanoids, and logLTE4 /logPGE2 ratio. Class 2 represented severe asthma with impaired lung function despite high doses of steroids. High sputum eosinophilia was in line with higher pro-inflammatory LTE4 in ISS and the highest logLTE4 /logPGE2 ratio. Class 3 subjects had mild-to-moderate asthma and were also characterized by eosinophilic airway inflammation, yet increased production of pro- (LTE4 , PGD2 and 11-dehydro-TBX2 ) was balanced by anti-inflammatory PGE2 . The value of logLTE4 /logPGE2 was between values calculated for classes 1 and 3, similarly to disease control and severity.

CONCLUSIONS

LCA revealed three distinct NERD subphenotypes. Our results support a more complex pathobiology of aspirin hypersensitivity. Considering NERD heterogeneity, the relationship between inflammatory pathways and clinical manifestations of asthma may lead to more individualized treatment in difficult to treat patients in the future.