Cytokines in Chronic Rhinosinusitis. Role in Eosinophilia and Aspirin-exacerbated Respiratory Disease

Nasal biomarkers of immune function differ based on smoking and respiratory disease status

Respiratory biomarkers have the potential to identify airway injury by revealing inflammatory processes within the respiratory tract. Currently, there are no respiratory biomarkers suitable for clinical use to identify patients that warrant further diagnostic work-up, counseling, and treatment for toxic inhalant exposures or chronic airway disease. Using a novel, noninvasive method of sampling the nasal epithelial lining fluid, we aimed to investigate if nasal biomarker patterns could distinguish healthy nonsmoking adults from active smokers and those with chronic upper and lower airway disease in this exploratory study. We compared 28 immune mediators from healthy nonsmoking adults (n = 32), former smokers with COPD (n = 22), chronic rhinosinusitis (CRS) (n = 22), and smoking adults without airway disease (n = 13). Using ANOVA, multinomial logistic regressions, and weighted gene co-expression network analysis (WGCNA), we determined associations between immune mediators and each cohort. Six mediators (IL-7, IL-10, IL-13, IL-12p70, IL-15, and MCP-1) were lower among disease groups compared to healthy controls. Participants with lower levels of IL-10, IL-12p70, IL-13, and MCP-1 in the nasal fluid had a higher odds of being in the COPD or CRS group. The cluster analysis identified groups of mediators that correlated with disease status. Specifically, the cluster of IL-10, IL-12p70, and IL-13, was positively correlated with healthy and negatively correlated with COPD groups, and two clusters were correlated with active smoking. In this exploratory study, we preliminarily identified groups of nasal mucosal mediators that differed by airway disease and smoking status. Future prospective, age-matched studies that control for medication use are needed to validate these patterns and determine if nasosorption has diagnostic utility for upper and lower airway disease or injury.

Inflammatory mediators in nasal secretions of patients with nasal polyposis with and without aspirin sensitivity

BACKGROUND

The aim of this cross-sectional study was to compare the levels of inflammatory mediators in nasal secretions in patients with aspirin-exacerbated respiratory disease (AERD) and in those with nasal polyposis (NP) without aspirin-sensitivity and to correlate nasal fluid mediator concentrations with clinical parameters of the disease.

METHODS

A total of 30 patients with AERD, 30 chronic rhinosinusitis (CRS) with NP patients without aspirin sensitivity (CRSwNP), and 30 control subjects without inflammation of the nasal mucosa (C), selected for surgical treatment entered the study. The total nasal symptom score (TNSS), endoscopic score (ES), and Lund-Mackay score (LMS), were evaluated. The concentrations of eosinophil cationic protein (ECP), tryptase, heat shock protein 70 (HSP70), substance P and Clara cell protein 16 (CC16) were determined in nasal secretions.

RESULTS

Higher concentrations of ECP, tryptase, and HSP70 were measured in the AERD patients than in the CRSwNP patients and the C group (p < .001; p < .001, respectively for all mediators). However, levels of CC16 were higher in the C group than in the AERD and CRSwNP groups (p < .001; p < .001, respectively). A positive correlation between the TNSS and CC16 and a negative one between CC16 and tryptase levels were found in the C group. The CRSwNP group showed positive correlations between ECP, HSP70, and tryptase and negative correlations between substance P, ES, and LMS, as well as between CC16 and tryptase levels. In the AERD group, we found a positive correlation between HSP70 and ECP levels and a negative correlation between the TNSS and CC16 concentration.

CONCLUSION

The obtained results indicate the increased production of mediators of eosinophil and mast cell function, and the decreased production of biomarker of respiratory epithelial function in AERD patients. Clinical and biochemical parameters correlate in different ways in the AERD and CRSwNP patients.

High proportion of inflammatory CD62Llow eosinophils in blood and nasal polyps of severe asthma patients

BACKGROUND

In mice models, eosinophils have been divided into different subpopulations with distinct phenotypes and functions, based on CD62L and CD101 patterns of membrane expression. Limited data are available in humans.

OBJECTIVE

To investigate eosinophils subpopulations in peripheral blood (PB) and nasal polyp tissue (NP) from severe eosinophilic asthma (SEA) patients plus concomitant chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

We recruited 23 SEA patients (14 with CRSwNP); as controls, we enrolled 15 non-severe asthma patients, 15 allergic rhinitis patients without asthma and 15 healthy donors. Eosinophils were isolated from PB and NP and analysed by FACS. Eotaxin-3 and eotaxin-1 mRNA expression in NP tissue was also evaluated.

RESULTS

A significantly higher percentage of circulating CD62L^low cells was observed in SEA, as compared with controls, expressing higher levels of CCR3, CD69 and lower levels of CD125 (IL-5R), CRTH2, CD86 and CD28 in comparison with CD62L^bright cells. In NP, eosinophils showed a high proportion of CD62L^low phenotype, significantly greater than that observed in PB. Surface expression of IL-3R, IL-5R, CD69 and CD86 was significantly higher in CD62L^low eosinophils from NP than in those from blood. Moreover, eotaxin-3 mRNA expression positively correlated with the percentage of CD62L^low cells in NP.

CONCLUSION

Two different eosinophil subphenotypes can be identified in blood and NP of SEA patients, with a preferential accumulation of CD62L^low inflammatory cells in NP.

The nasal microbiome in patients suffering from non-steroidal anti-inflammatory drugs-exacerbated respiratory disease in absence of corticosteroids

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease phenotypically classified by the absence (CRSsNP) or presence of nasal polyps (CRSwNP). The latter may also be associated with asthma and hypersensitivity towards non-steroidal anti-inflammatory drugs (NSAID) as a triad termed NSAID-exacerbated respiratory disease (N-ERD). The role of the microbiome in these different disease entities with regard to the underlying inflammatory process and disease burden is yet not fully understood. To address this question, we measured clinical parameters and collected nasal samples (nasal mucosal fluids, microbiome swabs from middle meatus and anterior naris) of patients suffering from CRSsNP (n=20), CRSwNP (n=20) or N-ERD (n=20) as well as from patients without CRS (=disease controls, n=20). Importantly, all subjects refrained from taking local or systemic corticosteroids or immunosuppressants for at least two weeks prior to sampling. The nasal microbiome was analyzed using 16S rRNA gene amplicon sequencing, and levels of 33 inflammatory cytokines were determined in nasal mucosal fluids using the MSD platform. Patients suffering from N-ERD and CRSwNP showed significantly worse smell perception and significantly higher levels of type 2 associated cytokines IL-5, IL-9, Eotaxin and CCL17. Across all 4 patient groups, Corynebacteria and Staphylococci showed the highest relative abundances. Although no significant difference in alpha and beta diversity was observed between the control and the CRS groups, pairwise testing revealed a higher relative abundance of Staphylococci in the middle meatus in N-ERD patients as compared to CRSwNP (p<0.001), CRSsNP (p<0.01) and disease controls (p<0.05) and of Lawsonella in patients suffering from CRSwNP in middle meatus and anterior naris in comparison to CRSsNP (p<0.0001 for both locations) and disease controls (p<0.01 and p<0.0001). Furthermore, we observed a positive correlation of Staphylococci with IL-5 (Pearson r=0.548) and a negative correlation for Corynebacteria and Eotaxin-3 (r=-0.540). Thus, in patients refraining from oral and nasal corticosteroid therapy for at least two weeks known to alter microbiome composition, we did not observe differences in microbiome alpha or beta diversity between various CRS entities and disease controls. However, our data suggest a close association between increased bacterial colonization with Staphylococci and decreased colonization by Corynebacteria as well as increased type 2 inflammation.

Bioinformatics analysis and verification of key candidate genes influencing the pathogenesis of chronic rhinosinusitis with nasal polyps

OBJECTIVES

Chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) is a prominent public health issue. Furthermore, the prognosis of eosinophilic CRSwNP is poor, with a high recurrence rate. The underlying molecular mechanisms of eosinophilic CRSwNP remain unclear. Therefore, in this study, we sought to determine the crucial genes underlying eosinophil infiltration in eosinophilic CRSwNP pathogenesis.

METHODS

We used the Gene Expression Omnibus database (GEO) (GSE36830 and GSE23552 datasets) to mine gene expression profiles of CRSwNP patients and normal subjects. Differentially expressed genes (DEGs) between normal and CRSwNP tissues were identified and subjected to the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses. Co-expression networks were established using a weighted gene co-expression network analysis (WGCNA) and single-sample gene set enrichment analysis (GSEA). Protein-protein interaction networks were developed to detect functional protein modules. Based on the common DEGs, candidate miRNAs and related lncRNAs were predicted using the mirTarBase and StarBase databases. Finally, we generated immune cell subtypes of CRSwNP.

RESULTS

A total of 146 DEGs were identified. Of these, 131 genes were upregulated, whereas 15 were downregulated. GO analysis indicated that DEGs primarily participated in leukocyte chemotaxis and migration as well as cell chemotaxis. KEGG pathway analysis suggested that DEGs participated in the interactions between cytokines and viral proteins, osteoclast differentiation, and cytokine-cytokine receptor interactions. Real-time quantitative polymerase chain reaction analysis showed that Complement C5a Receptor 1 (C5AR1), C-C Motif Chemokine Receptor 3 (CCR3), Complement C3a Receptor 1 (C3AR1), and C-C Motif Chemokine Ligand 13 (CCL13) expression levels were significantly upregulated in nasal polyps, whereas C-C Motif Chemokine Ligand 4 (CCL4) expression levels were significantly downregulated.

CONCLUSIONS

The candidate genes identified in this study may influence the activation and accumulation of eosinophils, cell chemotaxis, and inflammatory responses, thereby potentially representing molecular targets for future studies of CRSwNP.

CCL4 Regulates Eosinophil Activation in Eosinophilic Airway Inflammation

Eosinophilic chronic rhinosinusitis (ECRS) is a refractory airway disease accompanied by eosinophilic inflammation, the mechanisms of which are unknown. We recently found that CCL4/MIP-1β-a specific ligand for CCR5 receptors-was implicated in eosinophil recruitment into the inflammatory site and was substantially released from activated eosinophils. Moreover, it was found in nasal polyps from patients with ECRS, primarily in epithelial cells. In the present study, the role of epithelial cell-derived CCL4 in eosinophil activation was investigated. First, CCL4 expression in nasal polyps from patients with ECRS as well as its role of CCL4 in eosinophilic airway inflammation were investigated in an in vivo model. Furthermore, the role of CCL4 in CD69 expression-a marker of activated eosinophils-as well as the signaling pathways involved in CCL4-mediated eosinophil activation were investigated. Notably, CCL4 expression, but not CCL5, CCL11, or CCL26, was found to be significantly increased in nasal polyps from patients with ECRS associated with eosinophil infiltration as well as in BEAS-2B cells co-incubated with eosinophils. In an OVA-induced allergic mouse model, CCL4 increased eosinophil accumulation in the nasal mucosa and the bronchoalveolar lavage (BALF). Moreover, we found that CD69 expression was upregulated in CCL4-stimulated eosinophils; similarly, phosphorylation of several kinases, including platelet-derived growth factor receptor (PDGFR)β, SRC kinase family (Lck, Src, and Yes), and extracellular signal-regulated kinase (ERK), was upregulated. Further, CCR5, PDGFRβ, and/or Src kinase inhibition partially restored CCL4-induced CD69 upregulation. Thus, CCL4, which is derived from airway epithelial cells, plays a role in the accumulation and activation of eosinophils at inflammatory sites. These findings may provide a novel therapeutic target for eosinophilic airway inflammation, such as ECRS.

Current and Emerging Treatment Options in Sinus and Nasal Diseases: A Promising Future in the Appropriate Therapies

Chronic rhinosinusitis (CRS) is an inflammatory condition of the nose and paranasal sinuses defined by clinical symptoms, including two or more symptoms, one of which should be either nasal blockage or nasal discharge with or without facial pain/pressure or reduction in/loss of sense of smell [...].

Mepolizumab decreases tissue eosinophils while increasing type-2 cytokines in eosinophilic chronic rhinosinusitis

BACKGROUND

Eosinophilic chronic rhinosinusitis is an often treatment-resistant inflammatory disease mediated by type-2 cytokines, including interleukin (IL)-5. Mepolizumab, a monoclonal antibody drug targeting IL-5, has demonstrated efficacy and safety in inflammatory airway disease, but there is negligible evidence on direct tissue response. The study's aim was to determine the local effect of mepolizumab on inflammatory biomarkers in sinonasal tissue of eosinophilic chronic rhinosinusitis patients.

METHODS

Adult patients with eosinophilic chronic rhinosinusitis received 100mg mepolizumab subcutaneously at four-weekly intervals for 24 weeks in this prospective phase 2 clinical trial. Tissue eosinophil counts, eosinophil degranulation (assessed as submucosal eosinophil peroxidase deposition by immunohistochemistry) and cytokine levels (measured in homogenates by immunoassay) were evaluated in ethmoid sinus tissue biopsies collected at baseline and at weeks 4, 8, 16 and 24.

RESULTS

Twenty patients (47.7 ± 11.7 years, 50% female) were included. Sinonasal tissue eosinophil counts decreased after 24 weeks of treatment with mepolizumab (101.64 ± 93.80 vs 41.74 ± 53.76 cells per 0.1 mm² ; p = .035), eosinophil degranulation remained unchanged (5.79 ± 2.08 vs 6.07 ± 1.20, p = .662), and type-2 cytokine levels increased in sinonasal tissue for IL-5 (10.84 ± 18.65 vs 63.98 ± 50.66, p = .001), IL-4 (4.48 ± 3.77 vs 9.38 ± 7.56, p = .004), IL-13 (4.02 ± 2.57 vs 6.46 ± 3.99, p = .024) and GM-CSF (1.51 ± 1.74 vs 4.50 ± 2.97, p = .001).

CONCLUSION

Mepolizumab reduced eosinophils in sinonasal tissue, demonstrating that antagonism of IL-5 suppresses eosinophil trafficking. With reduced tissue eosinophils, a local type-2 inflammatory feedback loop may occur. The study exposes mechanistic factors which may explain incomplete treatment response.

[Expression and predictive value of type Ⅱ inflammatory cytokines in nasal secretion in eosinophilic chronic rhinosinusitis with nasal polyps]

Objective:To analyze the expression of type Ⅱ inflammatory-related cytokines in nasal secretions of patients with eosinophilic chronic rhinosinusitis with nasal polyps（ECRSwNP）, and to preliminarily explore the role of type Ⅱ inflammatory cytokines in nasal secretions in predicting ECRSwNP. Methods:A prospective analysis was made of 91 patients with CRSwNP who underwent endoscopic sinus surgery in Peking University Third Hospital from November 2020 to June 2021. All the selected patients had their SNOT-22 score, Lund-Mackay score and blood eosinophilia collected before surgery. Percentage and absolute value; the nasal secretions of patients were collected before operation, and enzyme-linked immunosorbent assay was used to detect the typeⅡinflammatory cytokines（IL-4, IL-5, IL-13, IL-25, IL-33, Eotaxin-3, periostin）, intraoperative nasal polyp tissue was collected for eosinophil count. According to the proportion of eosinophils in the tissue≥10%, they were divided into ECRSwNP group and nECRSwNP group. The clinical baseline data and type Ⅱ inflammatory cytokines were compared between the two groups, and the related factors of ECRSwNP were evaluated by univariate logistic regression analysis. The receiver operating characteristic（ROC） curve was used to evaluate the predictive potential of each clinical index. Results:The SNOT-22 score, Lund-Mackay score, blood eosinophil percentage and absolute value in the ECRSwNP group were higher than those in the nECRSwNP group（P<0.05）. In the nECRSwNP group（P<0.01）. Logistic regression analysis found that IL-5, Eotaxin-3 and blood eosinophil percentage were risk factors for ECRSwNP（P<0.05）. ROC analysis found that IL-5, Eotaxin-3 and blood eosinophil percentage had predictive diagnostic value（P<0.01）, among which blood eosinophil percentage had the greatest predictive value（AUC=0.756）. The prediction model composed of Eotaxin-3, SNOT-22 score, sinus CT Lund-Mackay score, blood eosinophil percentage and blood eosinophil absolute value had better prediction effect on ECRSwNP（AUC=0.873）. Conclusion:Type Ⅱ inflammatory cytokines IL-5 and Eotaxin-3 in nasal secretions may be involved as biomarkers for early diagnosis of ECRSwNP.

M2 macrophage-related gene signature in chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common sinonasal inflammatory disorder with high heterogeneity. Increasing evidence have indicated that the infiltration of macrophages especially M2 macrophages play pivotal roles in the pathogenesis of CRSwNP, but the underlying mechanisms remain undetermined. This study sought to identify potential biomarkers related to M2 macrophages in CRSwNP.

METHODS

The expression datasets of GSE136825 and GSE179265 were download from Gene Expression Omnibus (GEO) database and merged. Then, CIBERSORT and weighted gene co-expression network analysis (WGCNA) algorithms were applied to identify M2 macrophage-related gene modules. Thereafter, differentially expressed genes (DEGs) related to M2 macrophages were selected to perform functional enrichment analyses. A protein-protein interaction (PPI) network was built to identify hub genes and quantitative real-time reverse transcriptions PCR was used to verify the bioinformatics results.

RESULTS

A total of 92 DEGs associated with M2 macrophages were identified for further analysis. The results of Gene ontology (GO) and Kyoto Encyclopedia of genes and genomes (KEGG) analyses illustrated that M2 macrophage-associated DEGs primarily enriched in immune responses and extracellular matrix structure. PPI network analysis identified 18 hub genes related to M2 macrophages that might be pivotal in the pathogenesis of CRSwNP. After verification, AIF1, C1QA, C1QB, C3AR1, CCR1, CD163, CD4, CD53, CD86, CSF1R, CYBB, FCER1G, FCGR3A, IL10RA, ITGB2, LAPTM5, PLEK, TYROBP were identified as potential M2 macrophage-related biomarkers for CRSwNP.

CONCLUSION

These findings yield new insights into the hub genes and mechanisms related to M2 macrophages in the pathogenesis of CRSwNP. Further studies of these hub genes would help better understand the disease progression and identify potential treatment targets.

Retinoic acid promotes fibrinolysis and may regulate polyp formation

BACKGROUND

Patients with aspirin-exacerbated respiratory disease (AERD) regularly exhibit severe nasal polyposis. Studies suggest that chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by excessive fibrin deposition associated with a profound decrease in epithelial tissue plasminogen activator (tPA). Retinoids, including vitamin A and its active metabolite retinoic acid (RA), are necessary for maintaining epithelial function and well-known inducers of tPA in endothelial cells.

OBJECTIVES

This study sought to determine whether endogenous retinoids are involved in NP pathophysiology and disease severity in patients with CRSwNP and AERD.

METHODS

NP tissue was collected from patients with AERD or CRSwNP, and concentrations of retinoids and fibrinolysis markers were measured using ELISA. Normal human bronchial epithelial cells were stimulated alone or in combination with RA and IL-13 for 24 hours.

RESULTS

This study observed lower retinoid levels in nasal polyps of patients with AERD than those with CRSwNP or healthy controls (P < .01). Levels of the fibrin-breakdown product d-dimer were the lowest in AERD polyps (P < .01), which is consistent with lower tPA expression (P < .01). In vitro, all-trans RA upregulated tPA levels in normal human bronchial epithelial cells by 15-fold and reversed the IL-13-induced attenuation of tPA expression in cultured cells (P < .01).

CONCLUSIONS

RA, a potent inducer of epithelial tPA in vitro, is reduced in tissue from patients with AERD, a finding that may potentially contribute to decreased levels of tPA and fibrinolysis in AERD. RA can induce tPA in epithelial cells and can reverse IL-13-induced tPA suppression in vitro, suggesting the potential utility of RA in treating patients with CRSwNP and/or AERD.

The roles of eosinophils and interleukin-5 in the pathophysiology of chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is generally associated with eosinophilic tissue infiltration linked to type 2 inflammation and characterized by elevated levels of interleukin (IL)-5 and other type 2 inflammatory mediators. Although distinct and overlapping contributions of eosinophils and IL-5 to CRSwNP pathology are still being explored, they are both known to play an important role in NP inflammation. Eosinophils secrete numerous type 2 inflammatory mediators including granule proteins, enzymes, cytokines, chemokines, growth factors, lipids, and oxidative products. IL-5 is critical for the differentiation, migration, activation, and survival of eosinophils but is also implicated in the biological functions of mast cells, basophils, innate lymphoid cells, B cells, and epithelial cells. Results from clinical trials of therapeutics that target type 2 inflammatory mediators (including but not limited to anti-IL-5, anti-immunoglobulin-E, and anti-IL-4/13) may provide further evidence of how eosinophils and IL-5 contribute to CRSwNP. Finally, the association between eosinophilia/elevated IL-5 and greater rates of NP recurrence after endoscopic sinus surgery (ESS) suggests that these mediators may have utility as biomarkers of NP recurrence in diagnosing and assessing the severity of CRSwNP. This review provides an overview of eosinophil and IL-5 biology and explores the literature regarding the role of these mediators in CRSwNP pathogenesis and NP recurrence following ESS. Based on current published evidence, we suggest that although eosinophils play a key role in CRSwNP pathophysiology, IL-5, a cytokine that activates these cells, also represents a pertinent and effective treatment target in patients with CRSwNP.

Effect of Dexamethasone and Lidocaine on the Cytokine Profile and Bleeding during Endoscopic Rhinosinus Surgery

The objective: to evaluate the feasibility of using dexamethasone and lidocaine to potentiate the effect of anesthesia in patients with chronic polypous rhinosinusitis during functional endoscopic sinus surgery (FESS) interventions.

Subjects and Methods. Clinical data, blood serum samples were collected prospectively from 52 patients who underwent FESS intervention. The patients were divided into 3 groups: Control Group ‒ C (n = 26), anti-inflammatory drugs were not administered; Dexamethasone Group ‒ D (n = 13), dexamethasone was administered (0.10‒0.15 mg/kg); and Lidocaine Group ‒ L (n = 13), a 1% solution of lidocaine was administered intravenously. The following parameters were studied: IL-6, IL-10, IL-18, alpha1-antitrypsin, and ferritin.

Results. An increase of IL-6, IL-6/IL-10 was observed in Group C. An increase of IL-10 and a decrease of IL-6, IL-6/IL-10 were noted in Group D. In Group L, IL-6, IL-6/IL-10 did not change significantly. The intensity of bleeding was lower in Groups L (p < 0.001) and D (p < 0.05) versus Group C. Relative changes in the concentration of biomarkers within the normal range were detected in all groups.

Conclusions. Changes in the cytokine profile are insignificant in patients with chronic polyposis rhinosinusitis during FESS performed under combined anesthesia.

No convincing data on the need for intraoperative use of dexamethasone or intravenous lidocaine have been received.

Roles of Exosomes in Chronic Rhinosinusitis: A Systematic Review

The pathophysiology of chronic rhinosinusitis (CRS) is multifactorial and not entirely clear. The objective of the review was to examine the current state of knowledge concerning the role of exosomes in CRS. For this systematic review, we searched PubMed/MEDLINE, Scopus, CENTRAL, and Web of Science databases for studies published until 7 August 2022. Only original research articles describing studies published in English were included. Reviews, book chapters, case studies, conference papers, and opinions were excluded. The quality of the evidence was assessed with the modified Office and Health Assessment and Translation (OHAT) Risk of Bias Rating Tool for Human and Animal Studies. Of 250 records identified, 17 were eligible, all of which had a low to moderate risk of overall bias. Presented findings indicate that exosomal biomarkers, including proteins and microRNA, act as promising biomarkers in the diagnostics and prognosis of CRS patients and, in addition, may contribute to finding novel therapeutic targets. Exosomes reflecting tissue proteomes are excellent, highly available material for studying proteomic alterations noninvasively. The first steps have already been taken, but more advanced research on nasal exosomes is needed, which might open a wider door for individualized medicine in CRS.

Local Immunoglobulin E in nasal polyps: Role and modulation

In the airway, IgE is traditionally regarded as a key mediator in allergic diseases, such as AR and allergic asthma. However, growing evidence demonstrates the importance of local IgE in airway inflammatory diseases, irrespective of the presence of allergy. In this review, we discuss the most recent evidence for IgE in chronic rhinosinusitis with nasal polyps(CRSwNP), including the local IgE’s characteristics, the modulation of its synthesis, and its function. The levels of local IgE are significantly elevated in polyps independently of IgE serum levels and atopic status. Local IgE, which is correlated with type 2 inflammation, is polyclonal and functional. IgE is produced by active B cells and is dependent on the class switch recombination(CSR). In NPs, this process is triggered by not only allergens but also microbial colonization, especially the superantigen- Staphylococcus aureus. The production of local IgE is modulated by lymphocytes(such as Tfh, ILC2s, iTreg), cytokines(such as IL-4, IL-13, IFN-γ, TGF-β, IL-2, IL-21), transcription factors, and B cell-intrinsic factor. Due to the central role of IgE in NPs, it is regarded as an ideal target for therapy and has been proved to be clinically successful. Based on this knowledge, we believe that exploring the trigger and regulatory factors for the activation of local B cells and CSR to IgE will provide more valuable information for us to recognize the pathological mechanisms of local IgE and offer the possible option for new therapeutic targets of nasal polyps.

Prognostic factors for polyp recurrence in chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps is frequently managed with endoscopic sinus surgery (ESS). Prior studies describe individual clinical variables and eosinophil density measures as prognostic for polyp recurrence (PR). However, the relative prognostic significance of these have not been extensively investigated.

OBJECTIVES

We sought to evaluate the impact of PR on measures of disease severity post-ESS and quantify the prognostic value of various clinical variables and biomarkers.

METHODS

Ninety-four patients with chronic rhinosinusitis with nasal polyps and prospectively biobanked polyp homogenates at the time of ESS were recruited 2 to 5 years post-ESS. Patients were evaluated with patient-reported outcome measures and endoscopic and radiographic scoring pre- and post-ESS. Biomarkers in polyp homogenates were measured with ELISA and Luminex. Relaxed least absolute shrinkage and selection operator regression optimized predictive clinical, biomarker, and combined models. Model performance was assessed using receiver-operating characteristic curve and random forest analysis.

RESULTS

PR was found in 39.4% of patients, despite significant improvements in modified Lund-Mackay (MLM) radiographic and 22-item Sinonasal Outcomes Test scores (both P < .0001). PR was significantly associated with worse post-ESS MLM, modified Lund-Kennedy, and 22-item Sinonasal Outcomes Test scores. Relaxed least absolute shrinkage and selection operator identified 2 clinical predictors (area under the curve = 0.79) and 3 biomarkers (area under the curve = 0.78) that were prognostic for PR. When combined, the model incorporating these pre-ESS factors: MLM, asthma, eosinophil cationic protein, anti-double-stranded DNA IgG, and IL-5 improved PR predictive accuracy to area under the curve of 0.89. Random forest analysis identified and validated each of the 5 variables as the strongest predictors of PR.

CONCLUSIONS

PR had strong associations with patient-reported outcome measures, endoscopic and radiographic severity. A combined model comprised of eosinophil cationic protein, IL-5, pre-ESS MLM, asthma, and anti-double-stranded DNA IgG could accurately predict PR.

Sweet taste receptor agonists attenuate macrophage IL-1β expression and eosinophilic inflammation linked to autophagy deficiency in myeloid cells

BACKGROUND

Eosinophilic inflammation is a hallmark of refractory chronic rhinosinusitis (CRS) and considered a major therapeutic target. Autophagy deficiency in myeloid cells plays a causal role in eosinophilic CRS (ECRS) via macrophage IL-1β overproduction, thereby suggesting autophagy regulation as a potential therapeutic modality. Trehalose is a disaccharide sugar with known pro-autophagy activity and effective in alleviating diverse inflammatory diseases. We sought to investigate the therapeutic potential of autophagy-enhancing agent, trehalose, or related sugar compounds, and the underlying mechanism focusing on macrophage IL-1β production in ECRS pathogenesis.

METHODS

We investigated the therapeutic effects of trehalose and saccharin on macrophage IL-1β production and eosinophilia in the mouse model of ECRS with myeloid cell-specific autophagy-related gene 7 (Atg7) deletion. The mechanisms underlying their anti-inflammatory effects were assessed using specific inhibitor, genetic knockdown or knockout, and overexpression of cognate receptors.

RESULTS

Unexpectedly, trehalose significantly attenuated eosinophilia and disease pathogenesis in ECRS mice caused by autophagy deficiency in myeloid cells. This autophagy-independent effect was associated with reduced macrophage IL-1β expression. Various sugars recapitulated the anti-inflammatory effect of trehalose, and saccharin was particularly effective amongst other sugars. The mechanistic study revealed an involvement of sweet taste receptor (STR), especially T1R3, in alleviating macrophage IL-1β production and eosinophilia in CRS, which was supported by genetic depletion of T1R3 or overexpression of T1R2/T1R3 in macrophages and treatment with the T1R3 antagonist gurmarin.

CONCLUSION

Our results revealed a previously unappreciated anti-inflammatory effect of STR agonists, particularly trehalose and saccharin, and may provide an alternative strategy to autophagy modulation in the ECRS treatment.

Utilization of Nasal Mucus to Investigate the Pathophysiology of Chronic Rhinosinusitis

BACKGROUND

Nasal mucus is proving to be a useful means by which to study the pathogenesis of chronic rhinosinusitis (CRS). Given the increase in publications examining nasal mucus and the lack of a review on this topic, we will focus on this noninvasive approach to studying CRS. Particular attention will be drawn towards inflammatory cytokines and biomarkers and their influence on disease severity.

METHODS

A literature review of papers published in English pertaining to nasal mucus was performed using the PubMed database. The search utilized combinations of the following keywords: sinusitis, polyps, sample collection, nasal mucus, or nasal secretion. Studies solely on acute or bacterial sinusitis, allergic rhinitis, or cystic fibrosis were not included.

RESULTS

A wide variety of materials and methods have been used to collect nasal mucus. Numerous assay types have been performed with the most common being ELISA, cytometric bead array, and proteomics. Most studies have focused on examining the levels of Th1/Th2 cytokines along with chemokines associated with type 2 immunity. Other factors identified include growth factors, senescence-associated proteins, complement, and antimicrobial defenses have also been identified. Nasal mucus cytokines have proven useful in cluster analysis and predicting postoperative improvement in Sino-nasal Outcome Test (SNOT-22) scores. One limitation of the use of nasal mucus is that some studies have suggested that nasal mucus does not always reflect the tissue microenvironment.

CONCLUSIONS

Nasal mucus represents a critical tool by which to examine the sinonasal microenvironment in a noninvasive manner. Unlike studies of tissue, it can be utilized in both surgically and medically managed patients and avoids the trauma of biopsies. However, studies are still needed to determine the most effective method for nasal mucus collection. Studies should also take care to confirm that nasal mucus markers do, in fact, reflect the levels of the product studied in the tissue.

Efficacy of an oral CRTH2 antagonist (AZD1981) in the treatment of chronic rhinosinusitis with nasal polyps in adults: A randomized controlled clinical trial

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease of the upper airways. AZD1981 is a selective antagonist of chemoattractant receptor-homologous molecule expressed on T helper type 2 and other type 2 cells, including innate lymphoid cells type 2, eosinophils, and basophils.

OBJECTIVE

To evaluate the efficacy of AZD1981 in reducing nasal polyp size when added to intranasal corticosteroids in adult patients with CRSwNP.

METHODS

Eighty-one subjects (18-70 years of age) with CRSwNP were recruited and screened for trial eligibility from allergy and otolaryngology clinics from a single tertiary care site between June 2016 and August 2019. Eligible patients were randomized in a double-blind fashion to receive either AZD1981 (n = 22) or placebo (n = 21) orally three times a day for 12 weeks, added to intranasal corticosteroids. The primary endpoint was a change in nasal polyp score (NPS) at 12 weeks. Secondary endpoints included improvement in sinus computed tomography using Lund Mackay scoring, symptoms using visual analog scale, quality of life using Sino Nasal Outcome Test-22, and the Brief Smell Identification Test.

RESULTS

Forty-three patients met the inclusion criteria and were enrolled. At 12 weeks, there was no difference in NPS change in the AZD1981 arm (mean 0, standard error 0.34, n = 15) compared with placebo (mean 0.20, standard error 0.36, n = 17); mean difference -0.20 (95% confidence interval: -1.21, 0.81; p = .69). No significant differences were observed for Lund Mackay score, symptoms, quality of life, or smell test. AZD1981 was well tolerated except for one case of hypersensitivity reaction.

CONCLUSION

In patients with CRSwNP, the addition of AZD1981 to intranasal corticosteroids did not change nasal polyp size, radiographic scores, symptoms, or disease-specific quality of life.

Type 2 inflammation in asthma and other airway diseases

Chronic inflammatory airway diseases, including asthma, chronic rhinosinusitis, eosinophilic COPD and allergic rhinitis are a global health concern. Despite the coexistence of these diseases and their common pathophysiology, they are often managed independently, resulting in poor asthma control, continued symptoms and poor quality of life. Understanding disease pathophysiology is important for best treatment practice, reduced disease burden and improved patient outcomes. The pathophysiology of type 2 inflammation is driven by both the innate immune system triggered by pollutants, viral or fungal infections involving type 2 innate lymphoid cells (ILC2) and the adaptive immune system, triggered by contact with an allergen involving type 2 T-helper (Th2) cells. Both ILC2 and Th2 cells produce the type-2 cytokines (interleukin (IL)-4, IL-5 and IL-13), each with several roles in the inflammation cascade. IL-4 and IL-13 cause B-cell class switching and IgE production, release of pro-inflammatory mediators, barrier disruption and tissue remodelling. In addition, IL-13 causes goblet-cell hyperplasia and mucus production. All three interleukins are involved in trafficking eosinophils to tissues, producing clinical symptoms characteristic of chronic inflammatory airway diseases. Asthma is a heterogenous disease; therefore, identification of biomarkers and early targeted treatment is critical for patients inadequately managed by inhaled corticosteroids and long-acting β-agonists alone. The Global Initiative for Asthma guidelines recommend add-on biological (anti IgE, IL-5/5R, IL-4R) treatments for those not responding to standard of care. Targeted therapies, including omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab and tezepelumab, were developed on current understanding of the pathophysiology of type 2 inflammation. These therapies offer hope for improved management of type 2 inflammatory airway diseases.

The Role of Allergen-Specific Immunotherapy in ENT Diseases: A Systematic Review

Previous studies have demonstrated that both subcutaneous (SCIT) and sublingual specific immunotherapy (SLIT) are effective in treating allergic rhinitis (AR). Further studies have evaluated the efficacy of allergen-specific immunotherapy (AIT) on different ear, nose, and throat (ENT) manifestations, in which allergy might have an etiopathogenetic role, such as local allergic rhinitis (LAR), rhinosinusitis (RS), otitis media (OM), and adenotonsillar (AT) disease. Nevertheless, the management of allergy in ENT diseases is still debated. To the best of our knowledge, this is the first systematic review assessing the efficacy of AIT in ENT diseases aside from AR. Literature data confirmed that AIT might be an effective therapeutic option in LAR, although its effect is restricted to studies with short-term follow-up. Furthermore, previous research demonstrated that AIT may improve symptoms and surgical outcomes of chronic rhinosinusitis when used as an adjunctive treatment. Few studies supported the hypothesis that AIT may exert positive therapeutic effects on recurrent upper airway infections as adenotonsillar disease. Finally, some clinical observations suggested that AIT may add some benefits in the management of otitis media with effusion (OME). The results of this systematic review allow us to conclude that the efficacy of AIT in ENT disorders has been only slightly investigated and additional studies are needed.

Benralizumab in Patients With Severe Eosinophilic Asthma With and Without Chronic Rhinosinusitis With Nasal Polyps: An ANANKE Study post-hoc Analysis

Background

Severe eosinophilic asthma (SEA) in the presence of chronic rhinosinusitis with nasal polyps (CRSwNP) indicates the presence of a more extensive eosinophilic inflammation. Post-hoc analyses from a pivotal clinical trial have demonstrated the enhanced efficacy of benralizumab on asthma outcomes in patients with CRSwNP as a comorbidity.

Methods

This is a post-hoc analysis from the Italian multi-center observational retrospective ANANKE study. Patients were divided into two groups based on self-reported CRSwNP. Baseline clinical and laboratory features in the 12 months prior to benralizumab prescription were collected. Data of change over time of blood eosinophils, annualized exacerbations rates (AER), asthma control, lung function, oral corticosteroids (OCS) use, and benralizumab discontinuation were collected during the observation period.

Results

At baseline, the 110 patients with CRSwNP were less frequently female (50.9% vs 74.2%) and obese (9.1% vs. 22.6%) with higher eosinophils (605 vs. 500 cells/mm3) and OCS use when compared to patients without CRSwNP. Similar reductions of AER were seen (-95.8% vs. -91.5% for any exacerbation and -99.1% vs. -92.2% for severe exacerbations in patients with and without CRSwNP, respectively). During benralizumab treatment, comorbid SEA+CRSwNP was associated with a lower risk of any exacerbation (p = 0.0017) and severe exacerbations (p = 0.025). After a mean ± SD exposure of 10.3 ± 5.0 months, half of the SEA+CRSwNP patients eliminated OCS use. No discontinuation for safety reasons was recorded.

Conclusions

This study helped to confirm the baseline clinical features that distinguish patients with and without CRSwNP being prescribed benralizumab. Numerically enhanced OCS reduction and lower exacerbation risk were observed in patients with SEA and comorbid CRSwNP treated with benralizumab.

TLR Signals in Epithelial Cells in the Nasal Cavity and Paranasal Sinuses

The respiratory tract is constantly at risk of invasion by microorganisms such as bacteria, viruses, and fungi. In particular, the mucosal epithelium of the nasal cavity and paranasal sinuses is at the very forefront of the battles between the host and the invading pathogens. Recent studies have revealed that the epithelium not only constitutes a physical barrier but also takes an essential role in the activation of the immune system. One of the mechanisms equipped in the epithelium to fight against microorganisms is the Toll-like receptor (TLR) response. TLRs recognize common structural components of microorganisms and activate the innate immune system, resulting in the production of a plethora of cytokines and chemokines in the response against microbes. As the epithelia-derived cytokines are deeply involved in the pathogenesis of inflammatory conditions in the nasal cavity and paranasal sinuses, such as chronic rhinosinusitis (CRS) and allergic rhinitis (AR), the molecules involved in the TLR response may be utilized as therapeutic targets for these diseases. There are several differences in the TLR response between nasal and bronchial epithelial cells, and knowledge of the TLR signals in the upper airway is sparse compared to that in the lower airway. In this review, we provide recent evidence on TLR signaling in the upper airway, focusing on the expression, regulation, and responsiveness of TLRs in human nasal epithelial cells (HNECs). We also discuss how TLRs in the epithelium are involved in the pathogenesis of, and possible therapeutic targeting, for CRS and AR.

Analysis of competing endogenous RNA (ceRNA) crosstalk in eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is one of the most common chronic inflammatory diseases, and has various phenotypes. Although its pathophysiology remains obscure, evidence has shown that dysregulation of noncoding RNAs (ncRNAs) is associated with CRSwNP. ncRNAs in the cytoplasm can act as competing endogenous RNAs (ceRNAs), which are involved in many inflammatory processes. However, the ceRNA crosstalk in CRSwNP is still unclear METHODS: We investigated expression profiles of messenger RNA (mRNA), microRNAs (miRNAs), and long noncoding RNAs (lncRNAs) in eosinophilic CRSwNP and constructed a global triple ceRNA network.

RESULTS

As a result, 964 differentially expressed mRNAs (DEmRs), 207 differentially expressed miRNAs (DEmiRs), and 15 differentially expressed lncRNAs (DElncRs) were identified, and a ceRNA network containing 598 miRNA-mRNA pairs and 70 lncRNA-miRNA pairs was finally constructed. Gene set enrichment analysis (GSEA) results indicated these DEmRs were mainly enriched in "cytokine-cytokine receptor interaction," "salivary secretion," "hematopoietic cell lineage," and "chemokine signaling pathway." Moreover, we also predicted the subcellular localization of the DElncRs identified in the network via bioinformatics approaches  CONCLUSION: In summary, the present study provided the first comprehensive assessment of the ceRNA crosstalk in eosinophilic CRSwNP. These findings will be of interest to the understanding of the potential pathophysiology of this disease.

Identification of a circRNA/miRNA/mRNA ceRNA Network as a Cell Cycle-Related Regulator for Chronic Sinusitis with Nasal Polyps

Purpose

To explore the mechanisms by which circRNA/miRNA/mRNA competitive endogenous RNAs (ceRNA) networks regulate CRSwNP.

Methods

The expression profiles of circRNAs, miRNAs, and mRNAs from patients with CRSwNP and control subjects were acquired from the Gene Expression Omnibus database. The circRNA/miRNA/mRNA ceRNA network was constructed based on the predicted circRNA–miRNA interactions and miRNA–mRNA interactions. Hub-mRNAs were screened by protein–protein interaction network analysis and Cytoscape molecular complex detection. The expression of factors in tissue and in hsa_circ_0031594 siRNA transfection cells was verified by RT-qPCR and the association between them was revealed by Spearman correlation analysis. Receiver operating characteristic curve analysis was performed with the pROC R package.

Results

The differential expression of 5423 circRNAs, 415 miRNAs, and 3673 mRNAs was identified in CRSwNP subjects compared to control subjects. Among these, 9 circRNAs, 39 miRNAs, and 78 mRNAs were screened to construct a ceRNA network. Ultimately, a subnetwork including circRNA hsa_circ_0031594, hsa-miR-1260b, hsa-miR-6507-5p, NCAPG2, RACGAP1, CHEK1 and PRC1 was screened out. RT-qPCR validated that the expression of hsa_circ_0031594, NCAPG2, PRC1 was significantly increased, and hsa-miR-1260b and hsa-miR-6507-5p were expressed significantly less in patients with CRSwNP than in control subjects. In addition, the AUCs of hsa_circ_0031594, hsa-miR-1260b, hsa-miR-6507-5p, NCAPG2, and PRC1 to discriminate CRSwNP patients were 0.995, 0.842, 0.862, 0.765, and 0.816. Spearman correlation showed that the expression of hsa_circ_0031594 was negatively correlated with hsa-miR-1260b and hsa-miR-6507-5p, and positively correlated with NCAPG2 and PRC1. In human nasal epithelial cell (HNEpC) line, knocking down hsa_circ_0031594 could increase the expression of hsa-miR-1260b and hsa-miR-6507-5p, and reduce the expression of NCAPG2 and PRC1.

Conclusion

CeRNA networks including hsa_circ_0031594, hsa-miR-1260b, and NCAPG2, and hsa_circ_0031594, hsa-miR-6507-5p, and PRC1 may be key regulators for CRSwNP occurrence, and may be potential targets for the pathogenesis and treatment development of CRSwNP.

Efficacy and safety of dupilumab in patients with uncontrolled severe chronic rhinosinusitis with nasal polyps and a clinical diagnosis of NSAID-ERD: Results from two randomized placebo-controlled phase 3 trials

Background

About one‐tenth of patients with difficult‐to‐treat chronic rhinosinusitis with nasal polyps (CRSwNP) have comorbid non‐steroidal anti‐inflammatory drug‐exacerbated respiratory disease (NSAID‐ERD). Dupilumab, a fully human monoclonal antibody that blocks the shared interleukin (IL)‐4/IL‐13 receptor component, is an approved add‐on treatment in severe CRSwNP. This post hoc analysis evaluated dupilumab efficacy and safety in patients with CRSwNP with/without NSAID‐ERD.

Methods

Data were pooled from the phase 3 SINUS‐24 and SINUS‐52 studies in adults with uncontrolled severe CRSwNP who received dupilumab 300 mg or placebo every 2 weeks. CRSwNP, nasal airflow, lung function, and asthma control outcomes at Week 24 were evaluated, and treatment–subgroup interactions were assessed for patients with and without NSAID‐ERD.

Results

Of 724 patients, 204 (28.2%) had a diagnosis of NSAID‐ERD. At Week 24, least squares mean treatment differences demonstrated significant improvements in nasal polyp score, nasal congestion (NC), Lund–Mackay computed tomography, 22‐item Sinonasal Outcome Test (SNOT‐22), Total Symptom Score (TSS), rhinosinusitis severity visual analog scale, peak nasal inspiratory flow (PNIF), six‐item Asthma Control Questionnaire score, and improvement in smell with dupilumab versus placebo (all p < .0001) in patients with NSAID‐ERD. Treatment comparisons demonstrated significantly greater improvements with dupilumab in patients with versus without NSAID‐ERD for NC (p = .0044), SNOT‐22 (p = .0313), TSS (p = .0425), and PNIF (p = .0123).

Conclusions

In patients with uncontrolled severe CRSwNP, dupilumab significantly improved objective measures and patient‐reported symptoms to a greater extent in the presence of comorbid NSAID‐ERD than without. Dupilumab was well tolerated in patients with/without NSAID‐ERD.

Endotypes of chronic rhinosinusitis: Relationships to disease phenotypes, pathogenesis, clinical findings, and treatment approaches

Chronic rhinosinusitis (CRS) is a common clinical syndrome that produces significant morbidity and costs to our health system. The study of CRS has progressed from an era focused on phenotype to include endotype-based information. Phenotypic classification has identified clinical heterogeneity in CRS based on endoscopically observed features such as presence of nasal polyps, presence of comorbid or systemic diseases, and timing of disease onset. More recently, laboratory-based findings have established CRS endotype based upon specific mechanisms or molecular biomarkers. Understanding the basis of widespread heterogeneity in the manifestations of CRS is advanced by findings that the three main endotypes, Type 1, 2, and 3, orchestrate the expression of three distinct large sets of genes. The development and use of improved methods of endotyping disease in the clinic are ushering in an expansion of the use of biological therapies targeting Type 2 inflammation now and perhaps other inflammatory endotypes in the near future. The purpose of this review is to discuss the phenotypic and endotypic heterogeneity of CRS from the perspective of advancing the understanding of the pathogenesis and improvement of treatment approaches and outcomes.

Updates on treatment options in aspirin exacerbated respiratory disease

PURPOSE OF REVIEW

The aim is to describe why this review is timely and relevant. Acetylsalicylic acid exacerbated respiratory disease (AERD) is a clinically significant disease affecting approximately 7% of all asthmatics or around 1,400,000 persons in the United States alone. A large portion of these patients remain undiagnosed. This review summarizes up to date knowledge on the pathophysiology, treatment opinions and provides an expert opinion on how to approach the AERD patient.

RECENT FINDINGS

Findings describe the main themes in the literature covered by the article. Review of the current knowledge in terms of the key cells, cytokines/chemokines contributing to the acquired disease state of AERD. It also provides clinical approach toward the AERD patient with regards to current treatment options.

SUMMARY

Summary describes the implications of the findings for clinical practice or research. This is an up-to-date review of the current literature, with insight into how to approach the management of an AERD patient.

Steroid affected cytokines in aspirin exacerbated respiratory disease

BACKGROUND

Patients with aspirin exacerbated respiratory disease (AERD) are among the most challenging rhinologic patients to treat. AERD has a complex inflammatory milieu of lipid mediators and cytokines. In this study we evaluated cytokine differences in the complex AERD environment at the mucus, epithelial and tissue levels.

METHODS

Samples were acquired at the time of sinus surgery from twenty-one patients (7 steroid-treated, 14 untreated) with aspirin challenge-confirmed AERD. Three methods (sponge adsorption, epithelial brushing, tissue biopsy) were used to acquire samples from the respective sinus sampling sites (mucus, polyp epithelium, and full thickness polyp) of each patient. We measured and compared 16 cytokine concentrations in AERD patients with or without prednisone treatment using the Luminex platform.

RESULTS

In most sampling sites, IL-5, IL-6, IL-10, IL-13, IL-33, CCL20, and TNF-α were detected at higher concentrations than IFN-γ, IL-1β, IL-17A, IL-4, IL-22, IL-17E/IL25 and GM-CSF. Each sampling site had a different pattern of cytokine levels and except for IL-5 and IL-25 there was no correlation among sampling methods for each cytokine tested. The most notable and significant decreases in cytokines from those treated with prednisone were observed in the epithelium for IL-5, IL-10, IL-33, and IFN-γ.

CONCLUSIONS

In the epithelial samples, type 2 associated cytokines IL-5 and IL-33, the anti-inflammatory cytokine IL-10, and IFN-γ were lower in AERD patients treated with prednisone. This work serves as a basis to assess therapeutic-induced mucosal cytokine responses in AERD and indicates that the site of cytokine measurement is an important consideration when assessing results. This article is protected by copyright. All rights reserved.

Elevated Serum Leptin Levels in Patients With Eosinophilic Chronic Rhinosinusitis

Background: Eosinophilic chronic sinusitis (ECRS) is a subtype of CRS with nasal polyps (CRSwNP) that is frequently comorbid with asthma. Notably, ECRS patients often show a high recurrence of NPs after surgical resection. Leptin is a hormone produced by adipocytes that has been implicated in airway inflammatory diseases. However, to date, the role of leptin in ECRS has not been investigated. Objective: To determine whether the serum levels of leptin are altered in patients with ECRS. Methods: In total, 40 patients with ECRS, 15 patients with non-eosinophilic CRS (non-ECRS), and 12 individuals without CRS (control) were included in this study. Patient's serum leptin levels were assessed, and the number of eosinophils in their NPs were measured through a histological evaluation of the three densest areas with cellular infiltrate beneath the epithelial surface. Finally, nasal fibroblast cultures established from NPs were stimulated with varying concentrations of recombinant leptin in vitro to determine whether leptin affects eotaxin-3 (Chemokine (C-C motif) ligand 26 :26: CCL26) expression. Results: The serum leptin levels in both the ECRS and non-ECRS groups were significantly higher than those in the control subjects (p < 0.0001 vs. ECRS; p < 0.05 vs. non-ECRS). Furthermore, ECRS patients displayed significantly elevated serum leptin levels compared to non-ECRS patients (p < 0.001), although there was no difference in body mass index between the groups. Notably, serum leptin levels were correlated with the proportion of eosinophils in peripheral blood (r = 0.3575, p < 0.01) and the number of eosinophils in NPs (r = 0.5109, p < 0.0001). Serum leptin levels were also correlated with eotaxin-3 mRNA expression in NPs (r = 0.5374, p < 0.01). Finally, leptin significantly augmented eotaxin-3 expression in nasal fibroblasts established in vitro from NPs in a leptin receptor-dependent manner (p < 0.05). Conclusion: Leptin levels are elevated in ECRS patients and may both promote and indicate the severity of ECRS as well as systemic type 2-biased inflammatory responses. Combined, these data indicate that circulating leptin may play a significant role in the development of eosinophilic inflammation in NPs.

Emerging Biomarkers Beyond Leukotrienes for the Management of Nonsteroidal Anti-inflammatory Drug (NSAID)-Exacerbated Respiratory Disease

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD) is a unique condition characterized by aspirin/NSAID hypersensitivity, adult-onset asthma, and/or chronic rhinosinusitis with nasal polyps. Arachidonic acid metabolism dysregulation and intense eosinophilic/type 2 inflammation are central mechanisms in NERD. Studies have been conducted on various biomarkers, and urinary leukotriene E4 is considered the most available biomarker of NERD. However, the pathophysiology of NERD is heterogeneous and complex. Epithelial cells and platelets can interact with immune cells in NERD, and novel biomarkers related to these interactions have recently been investigated. We summarize emerging novel biomarkers of NERD and discuss their roles in the management of NERD.

Dupilumab efficacy in chronic rhinosinusitis with nasal polyps from SINUS-52 is unaffected by eosinophilic status

Background

The human monoclonal antibody dupilumab blocks interleukin (IL)‐4 andIL‐13, key and central drivers of type 2 inflammation. Dupilumab, on background mometasone furoate nasal spray (MFNS), improved outcomes in the phase III SINUS‐52 study (NCT02898454) in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). This posthoc analysis of SINUS‐52 examined whether eosinophilic status of CRSwNP was a predictor of dupilumab efficacy.

Methods

Patients were randomized 1:1:1 to dupilumab 300 mg every 2 weeks (q2w) until week 52; dupilumab 300 mg q2w until Week 24, then 300 mg every 4 weeks until week 52; or placebo (MFNS) until week 52. Coprimary endpoints were change from baseline in nasal polyps score (NPS), nasal congestion (NC), and Lund‐Mackay score assessed by CT (LMK‐CT) at week 24. Patients (n = 438) were stratified by eosinophilic chronic rhinosinusitis (ECRS) status according to the Japanese Epidemiological Survey of Refractory Eosinophilic Rhinosinusitis algorithm.

Results

Dupilumab significantly improved NPS, NC, and LMK‐CT scores versus placebo at week 24 in all ECRS subgroups (p < 0.001), with improvements maintained or increased at week 52 (p < 0.001). There was no significant interaction between ECRS subgroup (non‐/mild or moderate/severe) and dupilumab treatment effect for all endpoints at weeks 24 and 52 (p > 0.05), except LMK‐CT at week 24 (p = 0.0275). Similar results were seen for the secondary endpoints. Dupilumab was well tolerated across all ECRS subgroups.

Conclusion

Dupilumab produced consistent improvement in symptoms of severe CRSwNP irrespective of ECRS status. Therefore, blood eosinophil level may not be a suitable biomarker for dupilumab efficacy in CRSwNP.

Inflammatory molecular endotypes of nasal polyps derived from Caucasian and Japanese populations

BACKGROUND

Emerging evidence suggests that chronic rhinosinusitis with nasal polyps (CRSwNP) is a highly heterogeneous disease with disparate inflammatory characteristics between different racial groups and geographies. Little is known currently about possible distinguishing factors underlying these inflammatory differences.

OBJECTIVE

To interrogate for differences between Caucasian and Japanese CRSwNP disease using whole transcriptome and single-cell RNA gene expression profiling of nasal polyps (NPs).

METHODS

We performed whole transcriptome RNA sequencing (RNA-seq) with endotype stratification of NPs from 8 Caucasian (residing in USA) and 9 Japanese (residing in Japan) patients. Reproducibility was confirmed by qPCR in an independent validation set of 46 Caucasian and 31 Japanese patients. Single-cell RNA-seq stratified key cell types for contributory transcriptional signatures.

RESULTS

Unsupervised clustering analysis identified two major endotypes present within both NP cohorts, which have previously been reported at the cytokine level: 1) type 2 endotype and 2) non-type 2 endotype. Importantly, there was a statistically significant difference in the proportion of these endotypes between these geographically distinct NP subgroups (p = 0.03). Droplet-based single-cell RNA sequencing further identified prominent type 2 inflammatory transcript expression: C-C motif chemokine ligand 13 (CCL13) and CCL18 in M2 macrophages, as well as cystatin SN (CST1) and CCL26 in basal, suprabasal, and secretory epithelial cells.

CONCLUSION

NPs from both racial groups harbor the same two major endotypes, which we determine are present in differing ratios between each cohort with CRSwNP disease. Distinct inflammatory and epithelial cells contribute to the type 2 inflammatory profiles observed.

Revisiting Asian chronic rhinosinusitis in the era of type 2 biologics

Chronic rhinosinusitis (CRS) is a highly heterogeneous disorder exhibiting considerable epidemiological, clinical and immunopathological variations across patients with distinct ethnic backgrounds and in different geographic locations. Asian CRS patients present less eosinophilic and type 2 (T2) inflammation, but more prominent neutrophilic inflammation compared with patients in Western countries. Although several biologics targeting important elements of T2 inflammation, such as IL-4, IL-5, IL-13 and IgE, demonstrate promising benefit for Caucasian patients with recurrent nasal polyps, their efficacy in Asian patients remains poorly defined. The distinct endotypes in Asian patients warrant the identification and selection of patients who would benefit from T2 biologics in Asian countries. Additionally, developing novel treatments targeting neutrophilic, type 1, and type 3 inflammation may benefit approximately 50% of Asian CRS patients with non-T2 inflammation. In this review, we summarized and discussed recent progress in the study of Asian CRS endotypes in comparison with those in patients in Western countries, and the methods of identifying Asian patients with eosinophilic or T2 inflammation. T2 biologic treatment of Asian CRS patients, potential therapeutic candidates targeting non-T2 inflammation in Asian CRS patients and the progress on developing other T2 biologics were discussed.

Highlights in the advances of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a complex upper airway inflammatory disease with a broad spectrum of clinical variants. As our understanding of the disease pathophysiology evolves, so too does our philosophy towards the approach and management of CRS. Endotyping is gaining favour over phenotype-based classifications, owing to its potential in prognosticating disease severity and delivering precision treatment. Endotyping is especially useful in challenging CRS with nasal polyposis cases, for whom novel treatment options such as biologicals are now available. The latest European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS2020) reflects these changes with updated rhinosinusitis classifications and new integrated care pathways. With the coronavirus disease 2019 (COVID-19) pandemic, physicians and rhinologists have to balance the responsibility of managing their patients' upper airway while adequately protecting themselves from droplet and aerosol transmission. This review summarises the key updates from EPOS2020, endotype-based classification and biomarkers. The role of biologicals in CRS and the lessons we can draw from their use in severe asthma will be examined. Finally, the principles of CRS management during COVID-19 will also be discussed.

Epithelial-Cell-Derived Extracellular Vesicles in Pathophysiology of Epithelial Injury and Repair in Chronic Rhinosinusitis: Connecting Immunology in Research Lab to Biomarkers in Clinics

Epithelial barrier disruption and failure of epithelial repair by aberrant epithelial-mesenchymal transition (EMT)-induced basal cells observed in nasal mucosa of chronic rhinosinusitis (CRS) are speculated to play important roles in disease pathophysiology. Microparticles (MPs) are a type of extracellular vesicle (EV) released by budding or shedding from the plasma membrane of activated or apoptotic cells. MPs are detected in nasal lavage fluids (NLFs) and are now receiving attention as potential biomarkers to evaluate the degree of activation of immune cells and injury of structural cells in nasal mucosa of subjects with sinus disease. There are three types of epithelial-cell-derived MPs, which are defined by the expression of different epithelial specific markers on their surface: EpCAM, E-cadherin, and integrin β6 (ITGB6). When these markers are on MPs that are also carrying canonical EMT/mesenchymal markers (Snail (SNAI1); Slug (SNAI2); alpha-smooth muscle actin (αSMA, ACTA2)) or pro- and anti-coagulant molecules (tissue factor (TF); tissue plasminogen activator (tPA); plasminogen activator inhibitor-1 (PAI-1)), they provide insight as to the roles of epithelial activation for EMT or regulation of coagulation in the underlying disease. In this review, we discuss the potential of epithelial MPs as research tools to evaluate status of nasal mucosae of CRS patients in the lab, as well as biomarkers for management and treatment of CRS in the clinic.

Yardstick for the medical management of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is an inflammatory condition of the paranasal sinuses defined by classic symptoms, imaging findings, or endoscopic findings. There are a growing number of emerging pharmacologic therapies being evaluated to treat patients with CRS, some of which have gained indication status in the United States. There have not been updated treatment guidelines published in the United States however since 2014. This document is meant to serve as an updated expert consensus document for the pharmacologic management of patients with CRS. We review available data focusing on prospective clinical trials on oral and intranasal corticosteroids, nasal irrigation, biologics, antibiotics, and allergy immunotherapy for CRS both with and without nasal polyposis, including specific therapies for aspirin-exacerbated respiratory disease-associated CRS and allergic fungal CRS. There are multiple options to treat CRS, and clinicians should be knowledgeable on the efficacy and risks of these available therapies. Allergists-immunologists now have various therapies available to treat patients with CRS.

Local inflammatory marker production in Lithuanian patients with chronic rhinosinusitis with nasal polyps

There are two clinical subtypes of chronic rhinosinusitis (CRS): chronic rhinosinusitis with nasal polyps (CRSwNP) and chronic rhinosinusitis without nasal polyps (CRSsNP). The aim of the study here was to determine the levels of invasive inflammatory markers in nasal mucosa samples taken from CRSwNP patients during the surgery and to identify markers that could serve as targets for potential clinical and therapeutic interventions. The study was carried out in 59 patients with proven CRSwNP and a control group consisting of 52 healthy individuals. Concentrations of the inflammatory markers of interest were determined using a LuminexR Assay multiplex kit. The data obtained indicated that levels of inflammatory cytokines interleukin (IL)-2, -4, -5, -7, -12, -17 and -22 were all significantly higher in the nasal polyps (NP) than those in the mucosa of control participants. No differences were seen between the study groups for IL -6, -10, -13, -21 and interferon (IFN)-γ. OR (Odds Ratio) analyses confirmed that elevations in mucosal levels of IL-2, -4, -5, -7, -12, -17, and -22 were likely immune markers of CRSwNP. In conclusion, the present study demonstrated that IL-2, -4, -12 and -22 may be important in the etiopathogenesis of CRSwNP; as markers, each show moderate sensitivity, but high specificity in the Lithuanian population. IL-17 had good sensitivity, but low specificity in the CRSwNP patients.

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.

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.

Mepolizumab targets multiple immune cells in aspirin-exacerbated respiratory disease

BACKGROUND

Eosinophilic asthma and nasal polyposis are hallmarks of aspirin-exacerbated respiratory disease (AERD), and IL-5 inhibition has been shown to provide therapeutic benefit. However, IL-5Rα is expressed on many cells in addition to eosinophils, and the mechanisms by which IL-5 inhibition leads to clinical benefit in eosinophilic asthma and nasal polyposis are unlikely to be due exclusively to antieosinophil effects.

OBJECTIVE

We sought to identify the mechanisms by which anti-IL-5 treatment with mepolizumab improves respiratory inflammation in AERD.

METHODS

The clinical characteristics, circulating granulocytes, nasal scraping transcripts, eosinophilic cationic protein, tryptase, and antibody levels, and urinary and nasal eicosanoid levels were measured for 18 subjects with AERD who were taking mepolizumab and compared with those of 18 matched subjects with AERD who were not taking mepolizumab.

RESULTS

Subjects taking mepolizumab had significantly fewer peripheral blood eosinophils and basophils, and those cells that remained had higher surface CRTH2 expression than did the cells from subjects not taking mepolizumab. Nasal prostaglandin F_2α, prostaglandin D₂ metabolites, leukotriene B₄, and thromboxane levels were lower in subjects taking mepolizumab, as were urinary levels of tetranor-prostaglandin D₂ and leukotriene E₄. The nasal epithelial cell transcripts that were overexpressed among subjects with AERD who were taking mepolizumab were enriched for genes involved in tight junction formation and cilium organization. Nasal and urinary prostaglandin E₂, tryptase, and antibody levels were not different between the 2 groups.

CONCLUSION

IL-5 inhibition in AERD decreases production of inflammatory eicosanoids and upregulates tight junction-associated nasal epithelial cell transcripts, likely due to decreased IL-5 signaling on tissue mast cells, eosinophils, and epithelial cells. These direct effects on multiple relevant immune cells contribute to the mechanism of benefit afforded by mepolizumab.

Biologics for severe uncontrolled chronic rhinosinusitis with nasal polyps: a change management approach. Consensus of the Joint Committee of Italian Society of Otorhinolaryngology on biologics in rhinology

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous inflammatory condition of nasal mucosa and paranasal sinuses, predominantly mediated by type 2 inflammation and often associated with comorbid asthma and/or Exacerbated Respiratory Disease (N-ERD). The standard of care involves local and systemic corticosteroids and/or sinonasal surgery, although these options may be associated with recurrences and patients may require revision surgery. Difficult-to-treat patients, in fact, have a more severe disease requiring high systemic corticosteroid use and/or multiple sinonasal surgeries. Literature data suggests that biologic agents targeting specific key effectors of type 2 inflammation may offer supplemental therapy for patients with severe and uncontrolled CRSwNP, leading to significant improvement in several outcomes. For these reasons, over the years the endotyping of the disease has become increasingly important. Herein, we provide not only an update on the existing studies about the most promising biologics in CRSwNP, but also critical discussion on controversies about the use of biologics in severe uncontrolled CRSwNP. We finally provide consensus on strategic issues gathered among experts of the Joint Committee of Italian Society of Otorhinolaryngology on biologics in order to offer the best care for difficult to treat patients.

Management of Chronic Rhinosinusitis with Nasal Polyposis in the Era of Biologics

Purpose of Review

Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a phenotypic designation of the broader condition of chronic rhinosinusitis. The advent of targeted biologics has shown promise in targeting different aspects of the inflammatory pathway, yet there remains a lack of consensus on the correct timing and use of these medications. This review seeks to provide a concise update of the available literature on the pathophysiology of CRSwNP, the evolution and cost utility of biologics as it pertains to management of patients with CRSwNP, and evidence for each available biologic and its use in CRSwNP.

Recent Findings

There are two biologics with FDA approval for use in CRSwNP: dupilumab and omalizumab. Recent clinical trials of other biologic therapies targeting type 2 inflammatory pathways have also demonstrated efficacy both in symptom scores and nasal polyp reduction. However, studies have questioned the cost utility of these medications compared to other interventions. Furthermore, timing of use with respect to other interventions including surgery remains challenging.

Association between obesity and chronic rhinosinusitis with nasal polyps: a national population-based study

OBJECTIVES

We performed a cross-sectional analysis of data from the nationwide Korea National Health and Nutrition Examination Survey to evaluate the association between obesity and chronic rhinosinusitis with nasal polyps (CRSwNP) or without nasal polyp (CRSsNP).

DESIGN

Retrospective cross-sectional analysis of health survey data.

SETTING

Voluntary survey of representative South Korean populations.

PARTICIPANTS

In total, 32 384 individuals aged 19 years or older with available data on CRS and obesity were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

Diagnosis of CRSwNP or CRSsNP was performed by trained otolaryngologists through sinus endoscopy and surveys of medical history. General and central obesity was diagnosed using body mass index (BMI) and waist circumference (WC), respectively.

METHODS

A multivariate logistic regression analysis was used to clarify the association between CRSwNP or CRSsNP and obesity according to BMI and WC. Non-obese individuals were recruited as controls.

RESULTS

The prevalence of CRSwNP was higher in the general (OR, 1.438; 95% CI, 1.170 to 1.768; p<0.001) and central (OR, 1.251; 95% CI, 1.031 to 1.520; p=0.033) obesity groups than in the control group. Prevalence of CRSsNP was not correlated with obesity. In a logistic regression analysis, olfactory dysfunction (OR, 1.329; 95% CI, 1.137 to 1.553; p<0.001) and purulent discharge (OR, 1.383; 95% CI, 1.193 to 1.603; p<0.001) showed a higher incidence in the central obesity group than in the control group.

CONCLUSIONS

We demonstrated an association between CRSwNP and general and central obesity. Further investigations on the mechanism underlying this correlation are necessary for an improved understanding of the pathogenesis of CRSwNP.

Mepolizumab improves sino-nasal symptoms and asthma control in severe eosinophilic asthma patients with chronic rhinosinusitis and nasal polyps: a 12-month real-life study

Background:

Severe eosinophilic asthma is frequently associated to chronic rhinosinusitis and nasal polyposis (CRSwNP) that contribute to poor asthma control. Mepolizumab is an anti-IL-5 monoclonal antibody, approved for the treatment of severe eosinophilic asthma. A limited number of studies have assessed the efficacy of mepolizumab on CRSwNP in severe asthmatics. We aim to evaluate the efficacy of mepolizumab on sino-nasal symptoms, polyp growth and asthma control in severe eosinophilic asthma patients with CRSwNP in real life.

Methods:

In this study 44 severe eosinophilic asthma patients with CRSwNP were treated with mepolizumab (100 mg q4w) for 1 year. The following outcomes were assessed before (T0), after 6 (T6) and 12 months (T12) of treatment: sino/nasal outcome test (SNOT-22), Total Endoscopic Nasal Polyp Score (TENPS), %FEV1 (FEV1/FEV1 predicted) and Asthma control test (ACT). Blood eosinophil count, exhaled nitric oxide (FENO) and prednisone intake were measured. In a subgroup of patients, nasal cytology was performed before (T0), after 6 (T6) and after 12 months (T12) of treatment with mepolizumab.

Results:

We reported a significant reduction of SNOT-22 [from 51.5 ± 21.2 at baseline (T0) to 31.70 ± 17.36 at T6 and 29.7 ± 21.5 at T12 (T0–T12 p < 0.001)] and a decrease of TENPS (from 2.88 ± 3.07 to 1.70 ± 2.37 and 1.77 ± 2.56 at T0, T6 and T12, respectively, T0–T12 p = 0.99). A significant improvement of %FEV₁, ACT and a decrease in blood eosinophils and mean prednisone intake were also reported. No statistically significant decreasing trend was measured for FENO. Nasal cytology findings suggest a significant reduction of eosinophil percentage following mepolizumab treatment (from 16.8 ± 7.2% to 3.6 ± 6.2% and 0.8 ± 2.4% at T0, T6 and T12 respectively, T0 to T12: p < 0.001).

Conclusions:

Mepolizumab improves sino-nasal and asthma symptoms and reduces polyp growth in patients with severe eosinophilic asthma and concomitant CRSwNP in real life.

The reviews of this paper are available via the supplemental material section.

Microbiome profiling of uncinate tissue and nasal polyps in patients with chronic rhinosinusitis using swab and tissue biopsy

Chronic rhinosinusitis (CRS) is characterized according to the presence or absence of nasal polyps (NPs) and displays nasal microbiota dysbiosis. However, optimal sampling methods of the nasal microbiome in CRS have not been identified. We aimed to assess the microbial composition in patients with CRS, comparing different sampling methods (swab and tissue biopsy), tissue types (uncinate tissue and NP), and disease subtypes. Samples were obtained by swabbing the middle meatus and taking a biopsy of uncinate tissue (UT) in patients with CRS with (CRSwNP, N = 8) or without NP (CRSsNP, N = 6) and controls (N = 8). NPs were also harvested in CRSwNP. DNAs were extracted from fifty-two samples and analyzed by 16S rRNA gene amplicon sequencing. As a result, a great interpersonal variance was observed in nasal swabs, while UT samples presented distinct microbiome with low inter-personal differences. Moreover, the UT microbiomes were further differentiated into three clusters which are associated with disease status (control, CRSsNP, and CRSwNP). Compared to UT, NP revealed a unique microbiome profile with significantly less bacterial diversity. Prevotella was the genus whose abundance was negatively correlated with disease severity in NP. In conclusion, tissue samples are better specimens than nasal swabs for assessing the microbiomes of CRS patients. Several bacteria in UT and NP tissues revealed an association with clinical severity of CRSwNP.

Studies of the role of basophils in aspirin-exacerbated respiratory disease pathogenesis

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is characterized by the triad of chronic rhinosinusitis with nasal polyps (CRSwNP), asthma, and intolerance to cyclooxygenase-1 enzyme inhibitors. The underlying mechanisms contributing to AERD pathogenesis are not fully understood, but AERD is characterized by an enhanced type 2 inflammatory phenotype. Basophils are potent type 2 effector cells, but their involvement in AERD pathophysiology remains unclear.

OBJECTIVE

We sought to characterize the systemic and local basophil responses in patients with AERD compared with patients with CRSwNP.

METHODS

Sinonasal tissues including inferior turbinate and/or nasal polyps (NPs) and peripheral blood were collected from controls, patients with AERD, and patients with CRSwNP. Expression of cell surface (CD45, FcεRI, CD203c), activation (CD63), and intracellular (2D7) markers associated with basophils was characterized using flow cytometry. Clinical data including Lund-Mackay scores and pulmonary function were obtained.

RESULTS

The mean number of basophils (CD45⁺CD203c⁺FcεRI⁺CD117^-) detected in AERD NPs (147 ± 28 cells/mg tissue) was significantly elevated compared with that detected in CRSwNP NPs (69 ± 20 cells/mg tissue; P = .01). The number of circulating basophils was significantly elevated in patients with AERD (P = .04). Basophils in NPs had significantly higher CD203c and CD63 mean fluorescence intensity compared with blood in both conditions (P < .01). Basophils from AERD NPs had lower expression of the granule content marker 2D7 compared with those from matched blood (P < .01) or NPs of patients with CRSwNP (P = .06), suggesting ongoing degranulation. Basophil 2D7 mean fluorescence intensity significantly correlated with pulmonary function (r = 0.62; P = .02) and inversely correlated with sinonasal inflammation (r = -0.56; P = .004).

CONCLUSIONS

Increased basophil numbers and extent of ongoing degranulation in NPs of patients with AERD compared with patients with CRSwNP may contribute to the exaggerated disease pathogenesis and severity unique to AERD.

What is the contribution of IgE to nasal polyposis?

Taking a novel approach, this narrative review collates knowledge about nasal polyposis and the biological functions of IgE in several diseases (allergic rhinitis, allergic asthma, nonsteroidal anti-inflammatory drugs-exacerbated respiratory disease, and chronic spontaneous urticaria) to consider which IgE-mediated mechanisms are relevant to nasal polyposis pathology. A type 2 eosinophil-dominated inflammatory signature is typical in nasal polyp tissue of European patients with nasal polyposis, with a shift toward this endotype observed in Asian populations in recent years. Elevated polyclonal IgE is present in the nasal tissue of patients with and without allergy. It is derived from many different B-cell clones and, importantly, is functional (proinflammatory). Staphylococcus aureus enterotoxins are thought to act as superantigens, inducing production of polyclonal IgE via B-cell and T-cell activation, and triggering release of inflammatory mediators. In some patients, exposure to antigens/triggers leads to production of high levels of antigen-specific IgE, which mediates cross-linking of the high-affinity IgE receptor on various cells, causing release of inflammatory mediators. The efficacy of omalizumab confirms IgE as an important inflammatory mediator in nasal polyposis. By blocking IgE, omalizumab targets the T2 inflammation in nasal polyposis, reduces nasal polyp score and improves symptoms.