Let-7a-5p regulates the inflammatory response in chronic rhinosinusitis with nasal polyps

BACKGROUND

Let-7a-5p is demonstrated to be a tumor inhibitor in nasopharyngeal carcinoma. However, the role of let-7a-5p in chronic rhinosinusitis with nasal polyps (CRSwNP) has not been reported. This study is designed to determine the pattern of expression and role of let-7a-5p in CRSwNP.

METHODS

The expression level of let-7a-5p, TNF-α, IL-1β, and IL-6 in CRSwNP tissues and cells were detected by RT-qPCR. Western blot assay was carried out to measure the protein expression of the Ras-MAPK pathway. Dual luciferase reporter assay and RNA pull-down assay were used to explore the relationship between let-7a-5p and IL-6.

RESULTS

Let-7a-5p was significantly downregulated in CRSwNP tissues and cells. Moreover, the mRNA expression of TNF-α, IL-1β and IL-6 was increased in CRSwNP tissues, while let-7a-5p mimic inhibited the expression of TNF-α, IL-1β and IL-6. Besides that, let-7a-5p was negatively correlated with TNF-α, IL-1β and IL-6 in CRSwNP tissues. In our study, IL-6 was found to be a target gene of let-7a-5p. Additionally, let-7-5p mimic obviously reduced the protein levels of Ras, p-Raf1, p-MEK1 and p-ERK1/2, while IL-6 overexpression destroyed the inhibitory effect of let-7a-5p on the Ras-MAPK pathway in CRSwNP.

CONCLUSION

We demonstrated that let-7a-5p/IL-6 interaction regulated the inflammatory response through the Ras-MAPK pathway in CRSwNP.

Human airway mast cells proliferate and acquire distinct inflammation-driven phenotypes during type 2 inflammation

Mast cells (MCs) play a pathobiologic role in type 2 (T2) allergic inflammatory diseases of the airway, including asthma and chronic rhinosinusitis with nasal polyposis (CRSwNP). Distinct MC subsets infiltrate the airway mucosa in T2 disease, including subepithelial MCs expressing the proteases tryptase and chymase (MCTC) and epithelial MCs expressing tryptase without chymase (MCT). However, mechanisms underlying MC expansion and the transcriptional programs underlying their heterogeneity are poorly understood. Here, we use flow cytometry and single-cell RNA-sequencing (scRNA-seq) to conduct a comprehensive analysis of human MC hyperplasia in CRSwNP, a T2 cytokine-mediated inflammatory disease. We link discrete cell surface phenotypes to the distinct transcriptomes of CRSwNP MCT and MCTC, which represent polarized ends of a transcriptional gradient of nasal polyp MCs. We find a subepithelial population of CD38highCD117high MCs that is markedly expanded during T2 inflammation. These CD38highCD117high MCs exhibit an intermediate phenotype relative to the expanded MCT and MCTC subsets. CD38highCD117high MCs are distinct from circulating MC progenitors and are enriched for proliferation, which is markedly increased in CRSwNP patients with aspirin-exacerbated respiratory disease, a severe disease subset characterized by increased MC burden and elevated MC activation. We observe that MCs expressing a polyp MCT-like effector program are also found within the lung during fibrotic diseases and asthma, and further identify marked differences between MCTC in nasal polyps and skin. These results indicate that MCs display distinct inflammation-associated effector programs and suggest that in situ MC proliferation is a major component of MC hyperplasia in human T2 inflammation.

Mechanisms of Dupilumab

The Th2 cytokines interleukin 4 (IL-4) and IL-13 and the heterodimeric IL-4 receptor (IL-4R) complexes that they interact with play a key role in the pathogenesis of allergic disorders. Dupilumab is a humanized IgG4 monoclonal antibody that targets the IL-4 receptor alpha chain (IL-4Rα), common to both IL-4R complexes: type 1 (IL-4Rα/γc; IL-4 specific) and type 2 (IL-4Rα/IL-13Rα1; IL-4 and IL-13 specific). In this review, we detail the current state of knowledge of the different signalling pathways coupled to the IL-4R complexes and examine the possible mechanisms of Dupilumab action and survey its clinical efficacy in different allergic disorders. The development of Dupilumab and the widening spectrum of its clinical applications is relevant to the current emphasis on precision medicine approaches to the blockade of pathways involved in allergic diseases.

Predictive markers of long-term recurrence in chronic rhinosinusitis with nasal polyps

BACKGROUND

In last years, many attempts were made to recognize chronic rhinosinusitis with nasal polyps (CRSwNP) phenotypes focusing on identifying relevant key pathogenic molecules. Polyps recurrence rate ranges from 4% to 60%, so it's clear that not all clinical and immunologic factors associated with recurrence are known.

OBJECTIVE

We investigate the inflammatory profile in patients with long term recurrent and non-recurrent CRSwNPs and if a specific profile is associated with recurrence, comparing eosinophilic, neutrophilic and lymphocytic infiltration, as well as IL-5 and IL-8 expression to long term recurrence rate.

METHODS

This prospective study included 44 adult patients with CRSwNP treated with endoscopic sinus surgery between 2008 and 2010. Long term follow-up data (8-10 years) indicated that among 44 patients, 18 (40.1%) experienced long term recurrence of nasal polyposis needing maximal medical treatment or revision surgery. We realized two groups: one with patients who didn't present long term recurrence (26 patients) and another with patients who presented long term recurrence (18 patients) and in both groups eosinophilic, neutrophilic and lymphocytic infiltration and IL-5 and IL-8 expression were measured.

RESULTS

The parameters that reached statistical significance (p < 0.05) comparing the two groups were eosinophilic infiltration and IL-5 expression, whereas neutrophilic and lymphocytic infiltration, as IL-8 expression didn't show any significant difference. Asthma and aspirin intolerance seemed significantly more frequent in patients with recurrence, while allergy presented not statistically significant difference between two groups.

CONCLUSIONS

We can conclude that high eosinophilic infiltration and high IL-5 expression in CRSwNP correlate with higher rate of long term recurrence, while neutrophilic and lymphocytic infiltration, and IL-8 expression don't correlate with it. These findings provide the opportunity to improve our ability to predict the prognosis of surgical intervention, although it is still needed to explore the optimal predictor of outcome in CRSwNP.

Conjunctivitis in dupilumab clinical trials

BACKGROUND

Dupilumab blocks the shared receptor component for interleukin (IL)-4 and IL-13. It is approved in the U.S.A. for patients aged ≥ 12 years with moderate-to-severe atopic dermatitis (AD) uncontrolled by topical prescription medicines or who cannot use topical medicines, for patients in Japan whose AD is uncontrolled with existing therapies, for patients with moderate-to-severe AD in Europe who are candidates for systemic therapy and for patients aged ≥ 12 years for maintenance treatment of moderate-to-severe asthma uncontrolled with their current medicines. AD trials have reported increased incidence of conjunctivitis for dupilumab vs. placebo.

OBJECTIVES

To characterize further the occurrence and risk factors of conjunctivitis in dupilumab clinical trials.

METHODS

We evaluated randomized placebo-controlled trials of dupilumab in AD (n = 2629), asthma (n = 2876), chronic rhinosinusitis with nasal polyps (CRSwNP) (n = 60) and eosinophilic oesophagitis (EoE) (n = 47).

RESULTS

In most AD trials, dupilumab-treated patients had higher conjunctivitis incidence than placebo controls. Higher baseline AD severity and previous history of conjunctivitis were associated with increased conjunctivitis incidence. Conjunctivitis was mostly mild to moderate. Most cases recovered or resolved during the treatment period; two patients permanently discontinued dupilumab due to conjunctivitis or keratitis. Common treatments included ophthalmic corticosteroids, antibiotics, and antihistamines or mast cell stabilizers. Most cases were diagnosed by the investigators. In asthma and CRSwNP trials, the incidence of conjunctivitis was lower for both dupilumab and placebo than in AD trials; dupilumab did not increase the incidence compared with placebo. In the EoE trial, no patients had conjunctivitis.

CONCLUSIONS

Conjunctivitis was more frequent with dupilumab treatment in most AD trials. In dupilumab trials in other type 2 diseases, incidence of conjunctivitis was overall very low, and was similar for dupilumab and placebo. In AD, the incidence of conjunctivitis was associated with AD severity and prior history of conjunctivitis. The aetiology and treatment of conjunctivitis in dupilumab-treated patients require further study. What's already known about this topic? Ocular disorders, including allergic conjunctivitis, are common in patients with atopic dermatitis (AD). In most dupilumab AD trials, dupilumab-treated patients had higher conjunctivitis incidence than those receiving placebo. Most cases were mild to moderate and recovered or were recovering during study treatment; study treatment discontinuation due to conjunctivitis was rare. Conjunctivitis incidence was very low and similar for dupilumab and placebo in clinical trials in asthma, chronic rhinosinusitis with nasal polyps and eosinophilic oesophagitis. What does this study add? This analysis confirms and extends the results of the individual clinical trials. Baseline disease-related factors, including AD severity, prior conjunctivitis history and certain biomarkers (thymus and activation-regulated chemokine, IgE, eosinophils), were associated with increased incidence of conjunctivitis. Patients who responded well to dupilumab had reduced incidence of conjunctivitis. Further study is needed to elucidate the aetiology and treatment of conjunctivitis in dupilumab-treated patients with AD.

IL-1β, IL-23, and TGF-β drive plasticity of human ILC2s towards IL-17-producing ILCs in nasal inflammation

Innate lymphoid cells (ILCs) are crucial for the immune surveillance at mucosal sites. ILCs coordinate early eradication of pathogens and contribute to tissue healing and remodeling, features that are dysfunctional in patients with cystic fibrosis (CF). The mechanisms by which ILCs contribute to CF-immunopathology are ill-defined. Here, we show that group 2 ILCs (ILC2s) transdifferentiated into IL-17-secreting cells in the presence of the epithelial-derived cytokines IL-1β, IL-23 and TGF-β. This conversion is abrogated by IL-4 or vitamin D3. IL-17 producing ILC2s induce IL-8 secretion by epithelial cells and their presence in nasal polyps of CF patients is associated with neutrophilia. Our data suggest that ILC2s undergo transdifferentiation in CF nasal polyps in response to local cytokines, which are induced by infectious agents.

Upregulation of FZD5 in Eosinophilic Chronic Rhinosinusitis with Nasal Polyps by Epigenetic Modification

Eosinophilic chronic rhinosinusitis with nasal polyps (CRSwNP) is one of the most challenging problems in clinical rhinology. FZD5 is a receptor for Wnt5A, and its complex with Wnt5A contributes to activating inflammation and tissue modification. Nasal polyps and eosinophil/non-eosinophil counts are reported to be directly correlated. This study investigated the expression and distribution of FZD5, and the role of eosinophil infiltration and FZD5 in eosinophilic CRSwNP pathogenesis. The prognostic role of eosinophil levels was evaluated in seven patients with CRSwNP. Fifteen patients with CRS were classified based on the percentage of eosinophils in nasal polyp tissue. Methylated genes were detected using methyl-CpG-binding domain sequencing, and qRT-PCR and immunohistochemistry were used to detect FZD5 expression in nasal polyp tissue samples. The results showed that mRNA expression of FZD5 was upregulated in nasal polyps. FZD5 expression was significantly higher in nasal polyp samples from patients with eosinophilic CRSwNP than in those from patients with non-eosinophilic CRSwNP, as indicated by immunohistochemistry. Furthermore, inflammatory cytokine levels were higher in eosinophilic CRSwNP-derived epithelial cells than in normal tissues. In conclusion, FZD5 expression in nasal mucosal epithelial cells is correlated with inflammatory cells and might play a role in the pathogenesis of eosinophilic CRSwNP.

IFN-λ1 enhances Staphylococcus aureus clearance in healthy nasal mucosa but not in nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by TH2-skewed inflammation and increased colonization by Staphylococcus aureus. IFN-λ1 is known for its antiviral activity, but there is little information on its antibacterial role.

OBJECTIVE

We sought to determine the expression and release of IFN-λ1 from nasal mucosal tissue of healthy subjects and patients with CRSwNP on exposure to S aureus and assess its potential role in antibacterial defense mechanisms.

METHODS

Nasal tissue from healthy subjects and patients with CRSwNP was exposed to S aureus, and we assessed expression of IFN-λ1, MUC5AC, and MUC5B. THP1-derived macrophages incubated with or without IFN-λ1 were assessed for uptake and killing of S aureus and expression of lysosomal-associated membrane protein 1 and intracellular reactive oxidase substrate (ROS), the IFN-λ1 receptor IL-28 receptor (IL-28R), and the Janus kinase/signal transducer and activator of transcription (STAT) 1 pathway by means of immunofluorescence staining.

RESULTS

S aureus infection increased IFN-λ1 expression in tissue from patients with CRSwNP. IFN-λ1 (10 ng/mL) significantly decreased the number of S aureus colony-forming units in healthy control tissue but not in tissue from patients with CRSwNP and upregulated MUC5AC and MUC5B expression in control tissue on S aureus infection. IFN-λ1 stimulation increased intracellular killing of S aureus in THP1-derived macrophages and substantially increased lysosomal-associated membrane protein 1, IL-28R, ROS, and STAT signaling in macrophages incubated with S aureus. All of these effects were attenuated by blocking IL-28R and ROS activities.

CONCLUSIONS

IFN-λ1 favors clearance of S aureus in healthy nasal mucosa and enhances antibacterial function of macrophages through IFN-λ1-IL-28R-ROS-Janus kinase-STAT signaling pathways.

Chronic rhinosinusitis in elderly patients is associated with an exaggerated neutrophilic proinflammatory response to pathogenic bacteria

BACKGROUND

Potential effects of aging on chronic rhinosinusitis (CRS) pathophysiology have not been well defined but might have important ramifications given a rapidly aging US and world population.

OBJECTIVE

The goal of the current study was to determine whether advanced age is associated with specific inflammatory CRS endotypes or immune signatures.

METHODS

Levels of 17 mucus cytokines and inflammatory mediators were measured in 147 patients with CRS. Hierarchical cluster analysis was used to identify and characterize inflammatory CRS endotypes, as well as to determine whether age was associated with specific immune signatures.

RESULTS

A CRS endotype with a proinflammatory neutrophilic immune signature was enriched in older patients. In the overall cohort patients 60 years and older had increased mucus levels of IL-1β, IL-6, IL-8, and TNF-α when compared with their younger counterparts. Increases in levels of proinflammatory cytokines were associated with both tissue neutrophilia and symptomatic bacterial infection/colonization in aged patients.

CONCLUSIONS

Aged patients with CRS have a unique inflammatory signature that corresponds to a neutrophilic proinflammatory response. Neutrophil-driven inflammation in aged patients with CRS might be less likely to respond to corticosteroids and might be closely linked to chronic microbial infection or colonization.

PREVAILING CLINICO-PATHOGENETIC PARAMETERS IN PATIENTS WITH POLYPOUS RHINOSINUSITIS

Aim - Improvement of polypous rhinosinusitis anti-relapse treatment efficacy by distinguishing of the core meaningful factors of the disease's development. The study included 300 patients with polypous rhinosinusitis aged 18-77 years. Comprehensive evaluation of the data is done by means of factor analysis by the method of the main components with subsequent varimax-rotation of the factor axes. The critical value of p-level was 0.05. As a result of the factorial analysis, 6 main factors were identified, the joint action of which explains 53.72% of the variability of indicators for the polypous rhinosinusitis. The factor analysis allowed to distinguish the groups of indicators and estimate the specific weight of individual pathogenetic factors in the development of polypous rhinosinusitis, which might be conditionally combined under the general names of «clinic-immune», «clinic-pathomorphological», «immunoregulatory», «clinical-microbiological», «violation local protection»,»epidemiological and demographic «factors. The effect of two of the most powerful factors («clinical-immune» and «clinic-pathomorphological factor») is explained by 46.47% of the variability of indicators. Factor estimates for the most potent «clinically-immune-causative factor» with a high degree of reliability distinguished groups of patients with the first identified polypous rhinosinusitis and its relapse. Perspectives of further investigations are related to mathematical modeling of the pathological process using artificial neural networks.

High frequency of macrophages expressing elevated level of CD80, PD-Ls and TLR1 in nasal polyps of CRS patients

Identification of the association between tissue biomarkers, their surrogates in blood and clinical features, could provide new diagnostic tools and facilitate adequate choices of therapeutic interventions for selected patients suffering from CRS. The aim of present study was the assessment of macrophages in the polyp tissue and monocytes in the peripheral blood in the course of CRSwNP, and their functional immunophenotype. We analyzed 31 patients with CRSwNP. Nasal mucosa tissue was obtained via functional endoscopic sinus surgery (FESS). The control group included 10 patients with deviated nasal septum (DNS). Fluorochrome stained cells were proceed to acquisition using FACS Canto flow cytometer, and the results were analyzed using the software FACS Diva. In our study, we observed a significantly higher level of CD80, CD274, CD273 and TLR1 in nasal polyps compared to blood samples from patients with CRSwNP. This finding may suggest the importance of the PD-1 pathway as a therapeutic target in CRS and an important role for TLR1 in nasal polyp formation and maintenance. Our results may provide some insight into potential future targets of recurrent nasal polyp treatment and contribute to a better understanding of the inflammatory process in Chronic Rhinosinusitis.

C3a receptor antagonism as a novel therapeutic target for chronic rhinosinusitis

Chronic rhinosinusitis with nasal polyps (CRSwNP) is an inflammatory disease with an unknown etiology. Recent studies have implicated the complement system as a potential modulator of disease immunopathology. We performed proteomic pathway enrichment analysis of differentially increased proteins, and found an enrichment of complement cascade pathways in the nasal mucus of individuals with CRSwNP as compared to control subjects. Sinonasal mucus levels of complement 3 (C3) correlated with worse subjective disease severity, whereas no significant difference in systemic C3 levels could be determined in plasma samples. Given that human sinonasal epithelial cells were the predominate sinonasal source of C3 and complement anaphylatoxin 3a (C3a) staining, we focused on their role in in vitro studies. Baseline intracellular C3 levels were higher in CRSwNP cells, and following exposure to Aspergillus fumigatus (Af) extract, they released significantly more C3 and C3a. Inhibition of complement 3a receptor (C3aR) signaling led to a decrease in Af-induced C3 and C3a release, both in vitro and in vivo. Finally, we found in vivo that C3aR deficiency or inhibition significantly reduced inflammation and CRS development in a mouse model of Af-induced CRS. These findings demonstrate that local sinonasal complement activation correlates with subjective disease severity, and that local C3aR antagonism significantly ameliorates Af-induced CRS in a rodent model.

Solitary chemosensory cells are a primary epithelial source of IL-25 in patients with chronic rhinosinusitis with nasal polyps

BACKGROUND

IL-25 can function as an early signal for the respiratory type 2 response characteristic of allergic asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). In the mouse gut, tuft cells are the epithelial source of IL-25. However, the source of human airway epithelial IL-25 has remained elusive.

OBJECTIVE

In this study we sought to determine whether the solitary chemosensory cell (SCC) is the predominant source of IL-25 in the sinonasal epithelium.

METHOD

Flow cytometry and immunofluorescence for SCCs and IL-25 were used to interrogate polyp and turbinate tissue from patients with CRSwNP. Mucus was collected during acute inflammatory exacerbations from patients with CRSwNP or chronic rhinosinusitis without nasal polyps and IL-25 levels determined by using ELISA. Lastly, sinonasal epithelial cultures derived from polyp and turbinate tissue were stimulated with IL-13 and analyzed for SCC proliferation and IL-25 production.

RESULTS

This study demonstrates that a discrete cell type, likely an SCC, characterized by expression of the taste-associated G protein gustducin and the intestinal tuft cell marker doublecortin-like kinase 1, is the predominant source of IL-25 in the human upper airway. Additionally, we show that patients with CRSwNP have increased numbers of SCCs in nasal polyp tissue and that in vitro IL-13 exposure both increased proliferation and induced apical secretion of IL-25 into the mucosal layer.

CONCLUSIONS

Inflammatory sinus polyps but not adjacent turbinate tissue show expansion of the SCC population, which is the source of epithelial IL-25.

Allergic inflammatory memory in human respiratory epithelial progenitor cells

Barrier tissue dysfunction is a fundamental feature of chronic human inflammatory diseases1. Specialized subsets of epithelial cells-including secretory and ciliated cells-differentiate from basal stem cells to collectively protect the upper airway2-4. Allergic inflammation can develop from persistent activation5 of type 2 immunity6 in the upper airway, resulting in chronic rhinosinusitis, which ranges in severity from rhinitis to severe nasal polyps7. Basal cell hyperplasia is a hallmark of severe disease7-9, but it is not known how these progenitor cells2,10,11 contribute to clinical presentation and barrier tissue dysfunction in humans. Here we profile primary human surgical chronic rhinosinusitis samples (18,036 cells, n = 12) that span the disease spectrum using Seq-Well for massively parallel single-cell RNA sequencing12, report transcriptomes for human respiratory epithelial, immune and stromal cell types and subsets from a type 2 inflammatory disease, and map key mediators. By comparison with nasal scrapings (18,704 cells, n = 9), we define signatures of core, healthy, inflamed and polyp secretory cells. We reveal marked differences between the epithelial compartments of the non-polyp and polyp cellular ecosystems, identifying and validating a global reduction in cellular diversity of polyps characterized by basal cell hyperplasia, concomitant decreases in glandular cells, and phenotypic shifts in secretory cell antimicrobial expression. We detect an aberrant basal progenitor differentiation trajectory in polyps, and propose cell-intrinsic13, epigenetic14,15 and extrinsic factors11,16,17 that lock polyp basal cells into this uncommitted state. Finally, we functionally demonstrate that ex vivo cultured basal cells retain intrinsic memory of IL-4/IL-13 exposure, and test the potential for clinical blockade of the IL-4 receptor α-subunit to modify basal and secretory cell states in vivo. Overall, we find that reduced epithelial diversity stemming from functional shifts in basal cells is a key characteristic of type 2 immune-mediated barrier tissue dysfunction. Our results demonstrate that epithelial stem cells may contribute to the persistence of human disease by serving as repositories for allergic memories.

Superantigens and Chronic Rhinosinusitis: Skewing of T-Cell Receptor Vβ-Distributions in Polyp-Derived CD4+ and CD8+ T Cells

Background

Recent studies have suggested that Staphylococcus aureus secrete superantigenic toxins that play a role in the etiology of chronic rhinosinusitis with nasal polyposis (CRSwNP). Twenty S. aureus superantigens (SAg's) have been identified, each of which bind the Vβ-region of the T-cell receptor (TCR) outside the peptide-binding site. Approximately 50 distinct Vβ-domains exist in the human repertoire, and distinct SAg's will bind only particular domains generating a pattern of Vβ-enrichment in lymphocytes dependent on the binding characteristics of a given toxin. The aim of this study was to analyze the pattern of Vβ-expression in polyp-derived lymphocytes from CRSwNP patients.

Methods

Polyps were harvested from 20 patients with CRSwNP and 3 patients with antrochoanal polyps. Flow cytometry was used to analyze the Vβ-repertoire of polyp-derived CD4+ and CD8+ lymphocytes. Data were analyzed in light of the known skewing associated with SAg exposure in vivo and in vitro. Skewing was defined as a percentage of Vβ-expression >2 SD of that seen in normal blood.

Results

Seven of 20 subjects exhibited skewing in Vβ-domains with strong associations with S. aureus SAg's. The three antrochoanal polyps failed to show any significant Vβ-skewing.

Conclusion

This study establishes evidence of S. aureus SAg–T-cell interactions in polyp lymphocytes of 35% of CRSwNP patients. Although these results are consistent with intranasal exposure of polyp lymphocytes to SAg's, additional study is necessary to establish the role of these toxins in disease pathogenesis.

The Role of Anti-IgE Immunoglobulin Therapy in Nasal Polyposis: A Pilot Study

Background

Although the etiology of nasal polyposis (NP) remains unknown, emerging evidence showing elevated local IgE levels and eosinophilic infiltration suggests an allergic etiology. Given this evidence, this pilot study examined whether anti-IgE therapy is efficacious in the treatment of NP.

Methods

Data were retrospectively collected on two groups of patients with atopic asthma and NP who underwent endoscopic sinus surgery (ESS), including a control group (n = 4) and an anti-IgE treatment group (n = 4), who received the anti-IgE agent, omalizumab, postoperatively. Both groups were evaluated by sinus computed tomography (CT) and nasal endoscopic examination, and comparisons were made between the groups with respect to differences in the recurrence of NP after ESS.

Results

Collectively, the subjects showed a direct relationship between NP severity and pretreatment total serum IgE levels. Preoperatively, there were no differences between the groups with regard to their total serum IgE levels, sinus CT scores, and endoscopically determined NP scores. Relative to corresponding preoperative values, there was no significant improvement in the sinus CT scores in either treatment group postoperatively. In contrast, relative to preoperative values, the nasal polyp scores significantly improved in the anti-IgE group, whereas the control group showed no significant improvement.

Conclusion

This pilot study provides new evidence establishing that (1) endoscopic NP severity directly correlates to total serum IgE levels and (2) inclusion of anti-IgE therapy in the postpolypectomy management of atopic asthmatic individuals may reduce the severity of NP recurrence.

Functional role of kynurenine and aryl hydrocarbon receptor axis in chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is associated with mast cell-mediated inflammation and heightened oxidant stress. Kynurenine (KYN), an endogenous tryptophan metabolite, can promote allergen-induced mast cell activation through the aryl hydrocarbon receptor (AhR).

OBJECTIVES

We sought to determine the role of the KYN/AhR axis and oxidant stress in mast cell activation and the development of CRSwNP.

METHODS

We measured the expression of indoleamine 2,3-dioxygenase 1, tryptophan 2,3-dioxygenase, KYN, and oxidized calmodulin-dependent protein kinase II (ox-CaMKII) in nasal polyps and controls. KYN-potentiated ovalbumin (OVA)-induced ROS generation, cell activation, and ox-CaMKII expression were investigated in wild-type and AhR-deficient (AhR-/-) mast cells. The role of ox-CaMKII in mast cell activation was further investigated.

RESULTS

Nasal polyps in CRSwNP showed an increased expression of indoleamine 2,3-dioxygenase 1, tryptophan2,3-dioxygenase, and KYN compared with controls. AhR was predominantly expressed in mast cells in nasal polyps. Activated mast cells and local IgE levels were substantially increased in eosinophilic polyps compared with noneosinophilic polyps and controls. Furthermore, KYN potentiated OVA-induced ROS generation, intracellular Ca2+ levels, cell activation, and expression of ox-CaMKII in wild-type, but not in AhR-/- mast cells. Compared with noneosinophilic polyps and controls, eosinophilic polyps showed increased expression of ox-CaMKII in mast cells. Mast cells from ROS-resistant CaMKII MMVVδ mice or pretreated with CaMKII inhibitor showed protection against KYN-promoted OVA-induced mast cell activation.

CONCLUSIONS

These studies support a potentially critical but previously unidentified function of the KYN/AhR axis in regulating IgE-mediated mast cell activation through ROS and ox-CaMKII in CRSwNP.

5-Oxo-ETE from Nasal Epithelial Cells Upregulates Eosinophil Cation Protein by Eosinophils in Nasal Polyps in vitro

BACKGROUND

5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is a potent eosinophil chemoattractant and activator that is synthesized not only in inflammatory cells but also in bronchial epithelial cells. The purpose of this study is to clarify whether 5-oxo-ETE can promote the production of eosinophil cation protein (ECP) by eosinophils in nasal polyps (NP) in vitro, and whether normal nasal epithelial cells can produce this lipid mediator in response to oxidative stress.

MATERIALS AND METHODS

Nasal biopsy samples were obtained from normal subjects or subjects with chronic rhinosinusitis with NP. The infiltration of eosinophil in NP was detected and cultured. After that, concentrations of ECP in eosinophil and NP cultures were evaluated after the treatment of 5-oxo-ETE or 5-oxo-ETE + its receptor (OXER) antagonist, pertussis toxin (PT). Then we studied the synthesis of 5-oxo-ETE after H2O2 stimulation by normal nasal epithelial cells and by epithelial cells of NP alone in the cultures, and also determined the OXER expression in NP.

RESULTS

The number of infiltrative eosinophils in NP was increased. The ECP levels in eosinophil and NP cultures were enhanced after the administration of 5-oxo-ETE, and decreased by the PT treatment. 5-Oxo-ETE was upregulated in the cultures of nasal epithelial cells in the presence of H2O2 and of NP epithelial cells alone. The OXER was expressed in inflammatory cells, and not in epithelial cells.

CONCLUSION

5-Oxo-ETE produced by nasal epithelial cells may play a role in the formation and development of NP.

Evidence for altered levels of IgD in the nasal airway mucosa of patients with chronic rhinosinusitis

BACKGROUND

IgD is an enigmatic antibody isotype best known when coexpressed with IgM on naive B cells. However, increased soluble IgD (sIgD) levels and increased IgD+IgM- B-cell populations have been described in the human upper respiratory mucosa.

OBJECTIVE

We assessed whether levels of sIgD and IgD+ B cell counts are altered in nasal tissue from patients with chronic rhinosinusitis (CRS). We further characterized IgD+ B-cell populations and explored clinical and local inflammatory factors associated with tissue sIgD levels.

METHODS

sIgD levels were measured by means of ELISA in nasal tissues, nasal lavage fluid, sera, and supernatants of dissociated nasal tissues. IgD+ cells were identified by using immunofluorescence and flow cytometry. Inflammatory mediator levels in tissues were assessed by using real-time PCR and multiplex immunoassays. Bacterial cultures from the middle meatus were performed. Underlying medical history and medicine use were obtained from medical records.

RESULTS

sIgD levels and numbers of IgD+ cells were significantly increased in uncinate tissue (UT) of patients with chronic rhinosinusitis without nasal polyps (CRSsNP) compared with that of control subjects (4-fold, P < .05). IgD+ cells were densely scattered in the periglandular regions of UT from patients with CRSsNP. We also found that IgD+CD19+CD38bright plasmablast numbers were significantly increased in tissues from patients with CRSsNP compared with control tissues (P < .05). Among numerous factors tested, IL-2 levels were increased in UT from patients with CRSsNP and were positively correlated with tissue IgD levels. Additionally, supernatants of IL-2-stimulated dissociated tissue from patients with CRSsNP had significantly increased sIgD levels compared with those in IL-2-stimulated dissociated control tissue ex vivo (P < .05). Tissue from patients with CRS with preoperative antibiotic use or those with pathogenic bacteria showed higher IgD levels compared with tissue from patients without these variables (P < .05).

CONCLUSION

sIgD levels and IgD+CD19+CD38bright plasmablast counts were increased in nasal tissue of patients with CRSsNP. IgD levels were associated with increased IL-2 levels and the presence of pathogenic bacteria. These findings suggest that IgD might contribute to enhancement mucosal immunity or inflammation or respond to bacterial infections in patients with CRS, especially CRSsNP.