Pathogenesis of nasal polyposis

Basal Instinct: Persistence of Barrier Dysfunction

In a recent issue of Nature, Ordovas-Montanes et al. (2018) used cutting-edge genomic, epigenetic, and interventional techniques to characterize the cellular ecosystem in allergic chronic rhinosinusitis. They showed that basal epithelial cells "remember" type 2 inflammatory stimuli to maintain a chronic allergic disease phenotype.

Expression of IL-25, IL-33, and Thymic Stromal Lymphopoietin in Nasal Polyp Gland Duct Epithelium in Patients With Chronic Rhinosinusitis

Background

Nasal polyps accompany eosinophilic chronic rhinosinusitis (ECRS). Cytokines, including interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP) expressed in nasal mucosa have been implicated in polyp pathogenesis. We investigated the role of nasal polyp epithelium cytokine expression in eosinophilic infiltration in ECRS.

Methods

Tissues were collected from 39 patients undergoing nasal surgery. Cases were divided into 3 groups: control (CTR), non-ECRS (nECRS), and ECRS and were evaluated for IL-25, IL-33, and TSLP expression.

Results

Abundant eosinophilia was observed underneath the nasal mucosa and around the nasal ducts in polyps in ECRS and correlated positively with IL-33 protein expression.

Conclusion

Cytokine expression in nasal duct cells and eosinophilic infiltration around duct cells similar to those in the nasal mucosa occurred in the nasal epithelium of polyps, suggesting its role in inducing eosinophilic inflammation.

Intraoperative bacterial analysis in nasal polyposis: Clinical and functional impact

BACKGROUND

The impact of Staphylococcus aureus on onset of nasal polyposis has been the focus of numerous studies, but there have been few studies of other germs found in the ethmoid of operated patients or of their impact on post-operative results.

MATERIAL AND METHODS

All patients undergoing endoscopic radical ethmoidectomy for nasal polyposis in the teaching hospital of Nantes (France) between 2006 and 2016 had intraoperative ethmoid cavity bacterial sampling. Phenotypic characteristics, pre- and post-operative symptoms and endoscopic findings were analyzed. Mann-Whitney tests and Kruskal-Wallis correlation analysis were used to assess clinical/bacteriological correlations.

OBJECTIVES

The main objective was to describe bacterial colonization of patients undergoing surgery for nasal polyposis, and to assess correlations with phenotypic features, functional results and postoperative clinical course.

RESULTS

One hundred and seven patients were included. A total of 26% were not infected, 55% mono-infected and 19% multi-infected. In 27.3%, staphylococci were isolated; in 30.5%, isolates were gram-negative bacilli. There were no significant correlations between presence or type of pathogen and symptom profile.

CONCLUSION

This study confirmed the high rate of pathogenic bacteria in nasal cavities in case of polyposis, with high frequencies of S. aureus but also of gram-negative bacilli, raising the question of their involvement in the inflammatory reactions underlying the nasal polyposis.

Type 2/Th2-driven inflammation impairs olfactory sensory neurogenesis in mouse chronic rhinosinusitis model

BACKGROUND

Chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) is a chronic inflammatory disease often accompanied by impairment of sense of smell. This symptom has been somewhat overlooked, and its relationship to inflammatory cytokines, tissue compression, neuronal loss, and neurogenesis is still unclear.

METHODS

In order to elucidate potential mechanisms leading to CRS in humans, we have established a type 2/T helper type 2 cell (Th2)-mediated allergic CRS mouse model, based on house dust mite (HDM) and Staphylococcus aureus enterotoxin B (SEB) sensitization. The inflammatory status of the olfactory epithelium (OE) was assessed using histology, biochemistry, and transcriptomics. The sense of smell was evaluated by studying olfactory behavior and recording electro-olfactograms (EOGs).

RESULTS

After 22 weeks, a typical type 2/Th2-mediated inflammatory profile was obtained, as demonstrated by increased interleukin (IL)-4, IL-5, and IL-13 in the OE. The number of mast cells and eosinophils was increased, and infiltration of these cells into the olfactory mucosa was also observed. In parallel, transcriptomic and histology analyses indicated a decreased number of immature olfactory neurons, possibly due to decreased renewal. However, the number of mature sensory neurons was not affected and neither the EOG nor olfactory behavior was impaired.

CONCLUSION

Our mouse model of CRS displayed an allergic response to HDM + SEB administration, including the type 2/Th2 inflammatory profile characteristic of human eosinophilic CRSwNP. Although the sense of smell did not appear to be altered in these conditions, the data reveal the influence of chronic inflammation on olfactory neurogenesis, suggesting that factors unique to humans may be involved in CRSwNP-associated anosmia.

Mometasone furoate sinus implant - a new targeted approach to treating recurrent nasal polyp disease

Introduction: Chronic rhinosinusitis (CRS) is a broad heterogeneous inflammatory disorder of the nose and paranasal sinuses, resulting from the dysfunctional interplay between host immunity, defective epithelial barrier, and environmental factors. CRS with nasal polyps (CRSwNP) is considered a more severe clinical phenotype with greater burden of symptoms and higher relapse rate, especially with comorbid asthma or aspirin sensitivity. Available treatment options after endoscopic sinus surgery (ESS) - systemic corticosteroids or revision surgery - have significant risks and limitations. Areas covered: Bioabsorbable, steroid-eluting implants have been studied extensively for the ability to dilate and re-establish sinus patency by the localized, controlled delivery of topical corticosteroids to diseased sinonasal lining and nasal polyps. This review provides a comprehensive, up to date analysis of the literature regarding a novel, office-based, mometasone furoate (MF) sinus implant that may treat patients with recurrent CRSwNP after ESS. Expert commentary: Clinical evidence has demonstrated the safety and efficacy of steroid-eluting implant in the reduction of polyp size, symptom burden, and the need for revision sinus surgery. MF sinus implants may play an important role in the management of patients with recurrent polyposis after sinus surgery.

Current opinions for the management of asthma associated with ear, nose and throat comorbidities

Ear, nose and throat (ENT) comorbidities are common in patients with asthma and are frequently associated with poorer asthma outcomes. All these comorbidities are "treatable traits" in asthma. Identification and management of these disorders may spare medication usage and contribute to improved asthma control and quality of life, and a decrease in exacerbation rates.This review summarises recent data about the prevalence, clinical impact and treatment effects of ENT comorbidities in asthma including allergic rhinitis, chronic rhinosinusitis with and without nasal polyposis, aspirin-exacerbated respiratory disease, obstructive sleep apnoea and vocal cord dysfunction.Many of these comorbidities are possible to be managed by the pulmonologist, but the collaboration with the ENT specialist is essential for patients with chronic rhinosinusitis or vocal cord dysfunction. Further rigorous research is needed to study the efficacy of comorbidity treatment to improve asthma outcomes, in particular with the development of biotherapies in severe asthma that can also be beneficial in some ENT diseases.

Phosphoinositide 3-kinase-delta could be a biomarker for eosinophilic nasal polyps

Nasal polyps (NP) cause diverse clinical symptoms of chronic rhinosinusitis (CRS). Chronic inflammation of sinonasal mucosa is known to be crucial in NP formation. We aimed to define the implications of phosphoinositide 3-kinase (PI3K)-δ in nasal inflammation associated with NP by analyzing NP tissue obtained from CRS patients. Results showed that expression of p110δ, a regulatory subunit of PI3K-δ, in NP tissue was increased compared to control tissue. Increased p110δ expression was closely correlated with more severe CRS features. Interestingly, p110δ expression was increased in eosinophilic NP, which are closely related to more complicated clinical courses of the disease. Furthermore, CRS patients possessing NP with higher p110δ expression displayed more eosinophils in NP tissue and blood, higher levels of IL-5 in NP tissue, and more severe features of the disease. Therefore, PI3K-δ may contribute to the formation of NP, especially eosinophilic NP associated with more severe clinical presentations and radiological features.

How often is sinus surgery performed for chronic rhinosinusitis with versus without nasal polyps?

BACKGROUND

There currently are no data on the relative frequency of endoscopic sinus surgeries (ESS) performed for chronic rhinosinusitis with nasal polyposis (CRSwNP) versus chronic rhinosinusitis without nasal polyposis (CRSsNP) in the United States.

OBJECTIVES

To compare the rate of surgical interventions for CRSwNP and CRSsNP.

METHODS

Cases identified by CPT codes were extracted from the 2009-2011 State Ambulatory Surgery Databases for California, Florida, Maryland, and New York. Patient demographics, extent of surgery, mean charges, and operating room (OR) time were compared.

RESULTS

A total of 97,228 ESS cases were performed in the four states; 29.3% of surgeries were for patients with CRSwNP, 66.0% of patients with CRSsNP, and 4.8% for other indications. The proportion of ESS for CRSwNP varied across states, with California having the highest percentage (34.6%) and Maryland having the lowest (26.4%) (p < 0.0001). Patients with Medicaid (33.8%) and Medicare (32.2%) had higher rates of surgery for CRSwNP compared with patients with private insurance (29.9%) (p < 0.001). Surgeons who performed a higher volume of sinus surgery compared to lower volume surgeons performed a lower percentage of surgery for CRSwNP (24.4 versus 33.5%; p < 0.001). ESS cases for CRSwNP were more extensive (relative risk of four sinus surgeries of 1.88; p < 0.0001), used image guidance more frequently (relative risk, 1.39; p < 0.0001), and were less likely to include a balloon procedure (relative risk, 0.69; p < 0.0001). Patients with CRSwNP had longer OR times (ESS that involved all four sinuses took 14 minutes longer) (p < 0.0001), but no difference in charges compared with patients with CRSsNP who underwent a similar extent of surgery.

CONCLUSION

Almost 30% of ESS were performed for CRSwNP, and these cases were, on average, more extensive, used more OR time, and more often used image guidance than surgeries for CRSsNP. The rate of surgery performed for CRSwNP varied based on geography, payer, and surgical volume, which indicted that patient selection impacted surgical management.

Role of IL-13Rα2 in modulating IL-13-induced MUC5AC and ciliary changes in healthy and CRSwNP mucosa

BACKGROUND

The IL-13 receptor α2 (IL-13Rα2) is a receptor for IL-13 which has conflicting roles in mediating IL-13 responses in the lower airway, with little known about its impact on upper airway diseases. We sought to investigate the expression of IL-13 receptors, IL-13Rα1 and IL-13Rα2, in chronically inflamed nasal epithelium, and explore IL-13-induced signaling pathways in an in vitro model of human nasal epithelial cells (hNECs).

METHODS

The protein and mRNA expression levels of IL-13 and its receptors in nasal biopsies of patients with nasal polyps (NP) and healthy controls were evaluated. We investigated goblet cell stimulation with mucus hypersecretion induced by IL-13 (10 ng/mL, 72 hours) treatment in hNECs using a pseudostratified epithelium in air-liquid interface (ALI) culture.

RESULTS

There were significant increases in IL-13, IL-13Rα1, and IL-13Rα2 mRNA and protein levels in NP epithelium with healthy controls as baseline. MUC5AC mRNA positively correlated with IL-13Rα2 (r = .5886, P = .002) but not with IL-13Rα1 in primary hNECs. IL-13 treatment resulted in a significant increase in mRNA and protein levels of IL-13Rα2 only in hNECs. IL-13 treatment induced an activation of extracellular signal-regulated kinases (ERK)1/2 and an upregulation of C-JUN, where the IL-13-induced effects on hNECs could be attenuated by ERK1/2 inhibitor (50 μmol/L) or dexamethasone (10^-4 -10^-7  mol/L) treatment.

CONCLUSIONS

IL-13Rα2 has a potential role in IL-13-induced MUC5AC and ciliary changes through ERK1/2 signal pathway in the nasal epithelium. IL-13Rα2 may contribute to airway inflammation and aberrant remodeling which are the main pathological features of CRSwNP.

Expression of E-prostanoid receptors in nasal polyp tissues of smoking and nonsmoking patients with chronic rhinosinusitis

Background

Different inflammatory reactions have been observed in the polyp tissues of nonsmokers and smokers with chronic rhinosinusitis (CRS). E-prostanoid (EP) receptors play a role in the inflammatory processes. Cigarette smoke (CS) exposure regulates EP-receptor expression levels promoting inflammatory mediator release from various inflammatory cells. In this study, we characterize the EP-receptor expression profiles in the polyps of nonsmoking and smoking CRS patients to explore the possible role of CS in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP).

Methods

Polyp biopsies were obtained from 28 non-smoking and 21 smoking CRSwNP patients. Histopathological characteristics were observed under a light microscope. The prostaglandin E₂ (PGE₂), TNF-α, and IL-8 contents in polyp tissues were detected using enzyme-linked immunosorbent assay. Immunostaining was used to locate EP receptors in polyps. Messenger RNA and protein expression of EP receptors were examined using quantitative real-time polymerase chain reaction and Western blot, respectively.

Results

More severe inflammatory reactions occurred in polyp tissues of smoking CRSwNP patients. The PGE₂, TNF-α, and IL-8 in tissue homogenate levels were significantly higher in smoking CRSwNP patients than those in nonsmoking CRSwNP patients. Moreover, the distribution of each EP receptor subtype was similar in both groups. Compared with the EP-receptor expression in nonsmokers, messenger RNA and protein of EP2 and EP4 receptor were significantly down-expressed in smoking patients, but EP1 and EP3 receptors did not show significant differences.

Conclusion

CS exposure downregulates the expression levels of EP2 and EP4 receptors and stimulates the production of PGE₂ and the proinflammatory cytokine IL-8 and TNF-α in polyp tissues of CRS patients. The down-expressed EP2 and EP4 receptors might be associated with severe inflammatory reactions in smoking CRSwNP patients.

TREM-1 Neutrophil Activation Pathway Is Suppressed in Eosinophilic Nasal Polyps

Background Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by type 2 helper T-cell-skewed immune profiles, but the state of the neutrophil activation signaling pathway in CRSwNP is unknown. The purpose of this study was to examine neutrophil activation pathways in the pathogenesis of CRSwNP. Methods Institutional review board approved the study in which tissue proteomes were compared between control (inferior turbinate) and CRSwNP (nasal polyps) (n = 10/group) using an aptamer-based proteomic array and confirmed by whole transcriptomic analysis. Protein expression was analyzed using Student's t test and Benjamini-Hochberg procedures followed by the application of Ingenuity Pathway, MetaCore, and Genemania bioinformatics analyses. Results All the patients with CRSwNP (n = 10) had eosinophilic nasal polyps. Compared with controls, proteins associated with the triggering receptor expressed on myeloid cells 1 (TREM-1) neutrophil activation signaling pathway such as Calcineurin B, zeta chain-associated protein kinase of 70 kD (ZAP70), 14-3-3 protein theta, 14-3-3 protein zeta/delta, protein kinase C delta type (PKC-D), Interleukin (IL)-17B, IL-17B receptor, IL-23, and IL-1B were significantly decreased in CRSwNP (fold change [FC] = -1.60, P = .003; FC = -1.85, P = .040; FC = -1.26, P < .001; FC = -1.05, P = .008; and FC = -1.31, P = .004; FC = -1.22, P < .001; FC = -1.09, P = .022; FC = -1.25, P < .001; and FC = -1.31, P = .014; respectively). In contrast, tissue eosinophil count ( P < .001) and eosinophil-associated proteins such as C-C motif chemokine 17, periostin, and galectin 10 were all significantly increased in CRSwNP (FC = 1.56, P = .009; FC = 3.95, P < .001; and FC = 2.44, P < .001; respectively). Furthermore, the FC of the studied proteins' expression significantly and positively correlated with FC of their mRNA expression ( P = .001, r = .75). Conclusions TREM-1-associated neutrophilic signaling pathway proteins are significantly suppressed in eosinophilic CRSwNP.

Sex difference in counts of α4 and α7 nicotinic acetylcholine receptors in the nasal polyps of adults with or without exposure to tobacco smoke

OBJECTIVE

To assess counts of α4 and α7 nicotinic acetylcholine receptors in nasal polyps of adults with or without long-term exposure to cigarette tobacco smoke.

METHODS

Twenty-two patients with and 22 patients without exposure to cigarette tobacco smoke participated in the study. After endoscopic polypectomy, the fragments of the nasal polyps were analysed by immunohistochemistry.

RESULTS

Compared to patients with no exposure, patients with exposure showed higher counts of α4 and α7 nicotinic acetylcholine receptors (t-test, p 0.05).

CONCLUSION

Exposure to cigarette tobacco smoke may induce increased counts of α4 and α7 nicotinic acetylcholine receptors in nasal polyps of adults, with lower counts in males than females without exposure to tobacco smoke.

Aberrant expression of miR-663 and transforming growth factor-β1 in nasal polyposis in children

The aim of the present study was to investigate the expression of microRNA (miR)-663 and its regulatory effects on the pathogenesis of nasal polyposis in children. Nasal polyp tissue, as well as serum and peripheral blood eosinophils were collected from 35 children diagnosed with nasal polypectomy between August 2013 and August 2015. As a control, the inferior nasal concha, serum and peripheral blood eosinophils were collected from 46 patients with nasal septal deviation complicated by inferior turbinate hypertrophy or patients with simple inferior turbinate hypertrophy who had undergone surgical removal of the inferior nasal concha. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to measure the expression of miR-663 and transforming growth factor-β1 (TGF-β1) in the nasal polyp tissue, serum and peripheral blood eosinophils of patients with nasal polyposis and controls. Western blotting was used to measure the expression of TGF-β1 protein in nasal tissue and eosinophils and an enzyme-linked immunosorbent assay was used to measure serum level of TGF-β1 protein. A dual luciferase reporter assay was used to determine whether TGF-β1 was a target gene of miR-663. Compared with the control group, levels of TGF-β1 mRNA and protein were significantly increased in all three types of specimens from pediatric patients with nasal polyposis (P<0.05). miR-663 expression was significantly decreased in nasal polyp tissue and peripheral blood eosinophils (P<0.05). The dual luciferase reporter assay confirmed that TGF-β1 was a target gene of miR-663. The current study suggests that the upregulation of TGF-β1 may be associated with the downregulation of miR-663 in nasal polyposis in children. miR-663 may have regulatory effects on the pathogenesis of nasal polyposis by regulating TGF-β1 and may be developed as a genetic marker of nasal polyposis in children.

Interactions between dendritic cells and T lymphocytes in pathogenesis of nasal polyps

The aim of the present study was to investigate the functional status of dendritic cells (DCs) in nasal polyps (NP) and their interactions with T lymphocytes. The interactions between DC and T lymphocytes in the pathogenesis of NP was also studied. The expression of cluster of differentiation (CD)1a and CD83 in NP was detected using immunohistochemistry and the ratio of CD83 DC/CD1a+DC was counted. The distribution of DCs in NP and normal inferior turbinate mucosa (nITM) was evaluated using double immunostaining (CD1a/CD40) and low illumination fluorescence microscopy. The number of CD1a+ cells, CD83+ cells and CD1a/CD40-dual positive cells in was significantly higher in NP tissues compared with nITM. Furthermore, the density of DCs observed in NP was significantly greater than that observed in nITM. The ratio of CD83 DC/CD1a+DC in NP was significantly higher compared with in nITM tissues. The results of the present study revealed significant infiltration of DCs in NP, with the majority being mature DCs. DCs are able to interact with T cells via the CD40/CD40L costimulatory factor, thus serving an important role in the development and progression of NP.

Targeting Interleukin-5 or Interleukin-5Rα: Safety Considerations

Asthma is a highly prevalent chronic disease of the airways; approximately 10% of patients with asthma will experience a severe form of the disease. New understanding of the pathogenesis of asthma has enabled the development of novel drugs and provided hope for patients with asthma. Interleukin (IL)-5 and IL-5 receptor subunit α (IL-5-Rα) plays a crucial role in the development, maturation, and operation of eosinophils so were the first important therapeutic target of these new drugs. While the results of early clinical trials of these drugs were not promising, results improved once researchers discovered the drugs worked best in patients with high eosinophil levels. Patients treated with both anti-IL-5 and IL-5-Rα experienced significant decreases in exacerbations. Trials have also demonstrated promising safety profiles; adverse events have been few and frequently only observed with placebo or considered unrelated to the study drug. The positive efficacy and safety profiles of these drugs has led to trials with interesting results in other diseases that are also secondary to the action of eosinophils: Churg-Strauss syndrome, hypereosinophilic syndrome, nasal polyposis, chronic obstructive pulmonary disease, atopic dermatitis, and esophagitis. In this review, we explore the main clinical trials of anti-IL-5 and IL-5-Rα, both in asthma and in other pathologies, with particular reference to the interesting safety and efficacy results.

Recent advances in biologic therapy of asthma and the role in therapy of chronic rhinosinusitis

Great strides have been made in the last five years in understanding the pathology of chronic rhinosinusitis (CRS). CRS is now accepted to be the end-stage manifestation of inflammation resultant from various pathogenetic mechanisms. This has resulted in increasing recognition of distinct CRS endotypes. Such endotypes encompass a cluster of patients with similar pathogenic mechanisms that may have common therapeutic targets and responsiveness to interventions. The elucidation of mechanisms leading to the development of chronic upper (sino-nasal) airway inflammation has to some extent paralleled investigations of aberrant pathways operant in asthma. In this review, we focus on recent developments in understanding the innate immune pathways as well as adaptive (late) immune responses in CRS and asthma and their implication as potentially modifiable targets in CRS. Specific biologic therapy (that is, monoclonal antibodies targeting cytokines, cytokine receptors, or specific key molecules targeting inflammation) is an exciting proposition for the future of medical management of CRS. As of the writing of this article, the agents described are not approved for use in CRS; many have partial approval for use in asthma or are considered experimental.

Antronasal Polyp Extending to Orbital Fossa

Sinonasal infections and nasal polyps can be taken as 2 components of a disease. Polyps due to chronic inflammations of nasal cavity and sinuses are not rare. They may present with various clinical signs and symptoms, while the secondary complications may cause serious problems. They are most commonly treated medically, although surgery is the therapy of choice in some conditions. The complications can be listed as mucocele formation, orbital inflammation, intracranial extension by erosion of the boney structures.

Asthma onset pattern and patient outcomes in a chronic rhinosinusitis population

BACKGROUND

Chronic rhinosinusitis (CRS) is strongly associated with comorbid asthma. This study compares early-onset and late-onset asthma in a CRS population using patient-reported and clinical characteristics.

METHODS

At enrollment into a clinical registry, CRS patients completed the 22-item Sino-Nasal Outcome Test (SNOT-22), Asthma Control Test (ACT), mini-Asthma Quality of Life Questionnaire (miniAQLQ), the 29-item Patient-Reported Outcomes Measurement Information System (PROMIS-29), and medication use questionnaires. Patients also reported comorbid asthma and age at first asthma diagnosis. Early-onset (<18 years) and late-onset (>18 years) asthma groups were defined. Analysis of variance (ANOVA), chi-square, and Kruskal-Wallis tests were used to compare patient responses.

RESULTS

A total of 199 non-asthmatic (56.1%), 71 early-onset asthmatic (20.0%), and 85 late-onset asthmatic (23.9%) CRS patients completed the survey. Body mass index (BMI) was significantly higher in late-onset asthmatic (p = 0.046) while age, gender, race, and smoking history did not differ with time of asthma onset. SNOT-22, ACT, and miniAQLQ were not different between asthma groups, but late-onset asthmatics had significantly lower physical function than non-asthmatics (p = 0.008). Compared to non-asthmatics, late-onset asthmatics showed increased rates of nasal polyps (p < 0.001), higher Lund-Mackay scores (p = 0.005), and had received more oral steroid courses (p < 0.001) and endoscopic surgeries (p = 0.008) for CRS management. Late-onset asthmatics compared to early-onset asthmatics showed increased nasal polyposis (p = 0.011) and oral steroid courses for CRS (p = 0.003).

CONCLUSION

While CRS-specific and asthma-specific patient-reported outcome measures (PROMs) were not significantly different among groups, CRS patients with late-onset asthma had poorer physical function, more frequent nasal polyposis, and required increased treatment for CRS. Late-onset asthma may predict more severe disease in CRS.

Differential Hrd1 Expression and B-Cell Accumulation in Eosinophilic and Non-eosinophilic Chronic Rhinosinusitis With Nasal Polyps

Purpose

Hrd1 has recently emerged as a critical regulator of B-cells in autoimmune diseases. However, its role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) remains largely unexplored. This study aimed to examine Hrd1 expression and B-cell accumulation and their possible roles in CRSwNP.

Methods

Quantitative real-time polymerase chain reaction, immunohistochemistry, enzyme-linked immunosorbent assay and Western blotting were used to assess gene and protein expression in nasal tissue extracts. Cells isolated from nasal tissues and peripheral blood mononuclear cells were characterized by flow cytometry. Local antibody production was measured in tissue extracts with a Bio-Plex assay. Additionally, changes in Hrd1 expression in response to specific inflammatory stimuli were measured in cultured dispersed polyp cells.

Results

Nasal polyps (NPs) from patients with eosinophilic CRSwNP (ECRS) had increased levels of Hrd1, B-cells and plasma cells compared with NPs from patients with non-eosinophilic CRSwNP (non-ECRS) or other control subjects (P < 0.05). The average Hrd1 levels in B-cells in NPs from ECRS patients were significantly higher than those from non-ECRS patients and control subjects (P < 0.05). NPs also contained significantly increased levels of several antibody isotypes compared with normal controls (P < 0.05). Interestingly, Hrd1 expression in cultured polyp cells from ECRS patients, but not non-ECRS patients, was significantly increased by interleukin-1β, lipopolysaccharide and Poly(I:C) stimulation, and inhibited by dexamethasone treatment (P < 0.05).

Conclusions

Differential Hrd1 expression and B-cell accumulation between the ECRS and non-ECRS subsets suggests that they can exhibit distinct pathogenic mechanisms and play important roles in NP.

Biologic Therapies for Immunoglobulin E-mediated Food Allergy and Eosinophilic Esophagitis

Immunoglobulin (Ig) E-mediated food allergy and eosinophilic esophagitis (EoE) are chronic, allergen-mediated disorders characterized by an aberrant TH2 immune response. The development and investigation of biologics for the treatment of IgE-mediated food allergy and eosinophilic esophagitis have provided further insight into the pathophysiology and management of these disorders. This article provides an overview of biologic therapies that are being investigated or have potential as treatments for IgE-mediated food allergy and eosinophilic esophagitis. Identification of EoE phenotypes that are responsive to biologics and investigation of biologics combined with other therapies may help elucidate a role for biologics in EoE.

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.

Acquired Immunity in Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a prevalent disease that is associated with significant costs and quality of life impairments. Currently, patients are classified into subgroups based on clinical characteristics, most often the presence or absence of nasal polyps. However, despite medical and surgical treatment, many of these patients continue to have symptoms. Recent efforts have focused on gaining a more complete understanding of the inflammatory mechanisms that drive pathogenesis in CRS, and it is becoming clear that the inflammatory processes in CRS are quite complex. As our understanding of these complex phenotypes improves, it may become possible to classify patients into endotypes based on unique inflammatory patterns within the sinus mucosa. This information may also lead to the identification of appropriate targeted therapies for different endotypes. This review will discuss our current understanding of endotypes in CRS along with the unique adaptive immune responses that may contribute to these different endotypes and, finally, some potential targeted therapeutics for the next generation of CRS treatment strategies.

Sinonasal T-cell expression of cytotoxic mediators granzyme B and perforin is reduced in patients with chronic rhinosinusitis

BACKGROUND

CD8+ T cells and natural killer (NK) cells are cytotoxic cells that use granzyme B (GrB) and perforin. Defective cytotoxic function is known to play a role in dysregulated immune response as seen in chronic sinusitis, also referred to as chronic rhinosinusitis (CRS). However, to our knowledge, in the United States, neither GrB or perforin expression has been reported in patients with CRS.

OBJECTIVE

The aim of this study was to investigate sinonasal cytotoxic cells, their mediators, and cell-specific distribution of these mediators in patients with CRS with nasal polyp (CRSwNP) and in patients with CRS without nasal polyp (CRSsNP).

METHODS

Blood and sinus tissue samples were taken from patients with CRSsNP (n = 8) and CRSwNP (n = 8) at the time of surgery. Control subjects (n = 8) underwent surgery for cerebrospinal fluid leak repair or to remove non-hormone-secreting pituitary tumors. The cells were analyzed via flow cytometry by using CD8 expression to identify cytotoxic T cells and CD56 expression to identify NK cells. Intracellular GrB and perforin expression were analyzed with flow cytometry.

RESULTS

We observed no significant differences in plasma or peripheral blood immune cell numbers or specific levels of GrB or perforin among the groups. In the sinonasal mucosa of the patients with CRSsNP and the patients with CRSwNP, there was a significant decrease in GrB and perforin levels (p < 0.05) despite similar or increased numbers of cytotoxic cells when compared with the controls. The overall decrease in GrB and perforin in the sinonasal mucosa of the patients with CRSsNP and the patients with CRSwNP was due to decreased T cell production. There was no difference in total NK cell count or expression of perforin or GrB among all the groups.

CONCLUSION

Total levels of sinonasal GrB and perforin were decreased in the sinonasal mucosa of both the patients with CRSwNP and the patients with CRSsNP compared with the controls, whereas sinonasal CD8+ T cells, (but not NK cells,), intracellular stores of GrB and perforin were reduced in the patients with CRSwNP compared with the controls.

Micro RNA-19a interferes with IL-10 expression in peripheral dendritic cells of patients with nasal polyposis

The pathogenesis of nasal polyp is to be further investigated. Micro RNA (miR) plays a role in the development of allergic inflammation. Interleukin (IL)-10-producing dendritic cells (DC) have immune tolerogenic properties. This study test a hypothesis that miR-17-92 cluster is associated with suppressing IL-10 in peripheral DC. In this study, peripheral blood samples were obtained from 26 patients with nasal polyp. The CD11c DCs were isolated from the blood samples and analyzed for the expression of IL-10. We observed that, as compared with healthy subjects, the IL-10 expression in peripheral DC was significantly lower in polyp patients. The levels of miR-19a, but not the rest 5 members of the miR-17-92 cluster, were markedly higher in DCs in polyp group. Exposure to recombinant IL-4 suppressed the IL-10 expression in DCs, which was abolished by blocking histone deacetylase-11 or knocking down the miR-19a gene in DCs. We conclude that miR-19a plays a critical role in the suppression of IL-10 in peripheral DCs, which may be a target in the immune therapy for nasal polyp.

Osteopontin induced vascular endothelial growth factor production in dispersed nasal polyp cells through the phosphatidylinositol 3-kinase-protein kinase B and the extracellular signal-regulated kinase 1/2 pathways

BACKGROUND

Osteopontin (OPN) is involved in cell survival, migration, and angiogenesis. The role of OPN in inducing angiogenesis in tumor has been confirmed. In this study, we investigated the expression of OPN in patients with chronic rhinosinusitis (CRS) with nasal polyp (NP) and the relationship of OPN with vascular endothelial growth factor (VEGF) production.

METHODS

We enrolled 45 subjects with CRS (25 with CRS with NPs [CRSwNP] and 20 subjects with CRS without NPs [CRSsNP]), and with 14 normal controls to determine the expression of OPN and VEGF. The distribution, messenger RNA (mRNA), and protein levels of OPN and VEGF were examined by immunohistochemistry, quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay, respectively. The effect of OPN on the VEGF production was tested in dispersed NP cells (DNPC) and the involved signaling pathways were examined by Western blot.

RESULTS

In NP tissue of the subjects with CRSwNP, the epithelial cells, interstitial cells, glandular cells, and endothelial cells were positive for OPN and VEGF staining, whereas OPN and VEGF immunoactivity in specimens of subjects with CRSsNP and in normal controls was significantly reduced. We found that the immunostainings, the mRNA expression, and the protein levels of OPN and VEGF were significantly increased in NPs compared with normal controls. OPN induced VEGF production by DNPCs in a time- and dose-dependent manner through phosphatidylinositol 3-kinase- protein kinase B and the extracellular signal-regulated kinase 1/2 pathway. Moreover, VEGF also induced OPN production, which formed a positive feedback between OPN and VEGF.

CONCLUSION

Our findings demonstrated that OPN and VEGF were overproduced in NPs and that OPN induced VEGF production, which indicated that OPN-VEGF axis might contribute to angiogenesis in NPs.

Prognostic value of nasal cytology and clinical factors in nasal polyps development in patients at risk: can the beginning predict the end?

BACKGROUND

We evaluated the prognostic value of nasal cytology and clinical factors in predicting nasal polyp (NP) development in patients with history of nonallergic chronic sinonasal inflammation.

METHODS

This was a retrospective case-control study of 295 patients followed at our institution for a mean of 85.70 ± 19.41 months. According to the inclusion criteria we enrolled 84 cases with persistent eosinophilic nonallergic sinonasal inflammation (group A) and 106 cases with neutrophilic inflammation (group B), both without evidence of NPs at the baseline. We considered as controls 105 patients affected by nonallergic noninfectious vasomotor rhinitis without evidence of inflammation at nasal cytology (group C). Patients were checked every 6 months for NPs. Temporal analyses was performed by Kaplan-Mayer curves and odds ratios were evaluated by logistic regression analyses.

RESULTS

The percentage of patients that developed NPs was higher in group A (29/84 [34.52%]) than in group B (17/106 [16.03%]) and group C (5/104 [4.7%]) (p < 0.05). Logistic regression analyses showed that eosinophilic patients had a higher risk of NP development over the years than neutrophilic patients compared to controls (odds ratio [OR], 10.55 vs 3.2). We also demonstrated that hypereosinophilia, asthma, and aspirin intolerance may increase the OR differently in eosinophilic patients.

CONCLUSION

Our data suggest that early identification of inflammatory patterns and associated clinical factors in patients affected by chronic nonallergic sinonasal inflammation have a prognostic value that can help to identify patients with different risks of NP development. Our data confirm that detection of nasal eosinophilic inflammation represents an early marker for identification of a more aggressive inflammatory phenotype.

Bacterial Ball as an Unusual Finding in Patients With Chronic Rhinosinusitis

OBJECTIVES

Pathophysiology of chronic rhinosinusitis (CRS) is very complex and has not yet been clearly understood. To date, various factors have been researched to have relations with the pathogenesis of CRS, such as superantigens and biofilms. Recently, we found an unusual pathological finding in patients with CRS, and we called this new entity as bacteria ball (or bioball). In this study, we analyze the clinical characteristics of bacteria ball occurred in CRS.

METHODS

This study enrolled consecutive 247 patients with CRS who underwent functional endoscopic sinus surgery from January 2015 to August 2016. The diagnosis of bacterial ball was made when negative in Gomori-methenamine-silver stain and positive in Gram stain. Histologically, bacterial ball was defined as acellular mucous materials with bacterial colonies and inflammatory cell infiltrates. We compared clinical data and computed tomography (CT) findings between fungal and bacterial balls.

RESULTS

Six cases (2.4%) of CRS were confirmed histologically as bacterial ball. Most of them were found in the maxillary sinus of CRS without nasal polyposis (66.7%). Bacterial ball was green or brown colored materials similar to fungal ball which was harder and tightly adherent to the antral mucosa. Compared to fungal ball, patients with bacterial ball showed significantly less peripheral eosinophils (P=0.011) and calcification in CT scans (P=0.003).

CONCLUSION

Bacterial ball is unusual findings occurred in patient with CRS which is different from fungal ball and biofilm. For diagnosis of bacterial ball, Gram stain is essentially required to identify bacterial colonies. Bacterial ball might appear to be evidence of a new strategy for living in the paranasal sinuses.

Clinical predictors of remission and persistence of adult-onset asthma

BACKGROUND

Adult-onset asthma is an important but relatively understudied asthma phenotype and little is known about its natural course and prognosis. The remission rate is believed to be low, and it is still obscure which factors predict remission or persistence of the disease.

OBJECTIVE

This study sought to determine the remission rate and identify predictors of persistence and remission of adult-onset asthma.

METHODS

Two hundred adult patients with recently diagnosed (<1 year) asthma were recruited from secondary and tertiary pulmonary clinics and prospectively followed for 5 years. Clinical, functional, and inflammatory parameters were assessed at baseline and at yearly visits. Asthma remission was defined as absence of asthma symptoms for ≥1 year and no asthma medication use for ≥1 year. Descriptive statistics and logistic regression analysis were performed.

RESULTS

Five-year follow-up data of 170 patients (85%) was available. Of these, 27 patients (15.9%) experienced asthma remission. Patients with asthma persistence were older, had worse asthma control, required higher doses of inhaled corticosteroids, had more severe airway hyperresponsiveness, more often nasal polyps, and higher levels of blood neutrophils as compared to patients who experienced clinical remission. In a multivariable logistic regression analysis, only moderate to severe bronchial hyperresponsiveness and nasal polyps were independent predictors of asthma persistence. Patients with these 2 characteristics had <1% chance of asthma remission.

CONCLUSIONS

One in 6 patients with adult-onset asthma experiences remission within the first 5 years of the disease. In patients with moderate to severe bronchial hyperresponsiveness and nasal polyposis, the chance of remission is close to zero.

Chronic airway inflammation provides a unique environment for B cell activation and antibody production

BACKGROUND

B cells play many roles in health and disease. However, little is known about the mechanisms that drive B cell responses in the airways, especially in humans. Chronic rhinosinusitis (CRS) is an inflammatory disease of the upper airways that affects 10% of Europeans and Americans. A subset of CRS patients develop nasal polyps (NPs), which are characterized by type 2 inflammation, eosinophils and group 2 innate lymphoid cells (ILC2s). We have reported that NP contain elevated levels of B cells and antibodies, making NP an ideal system for studying B cells in the airways.

OBJECTIVE

We sought to determine the mechanisms that drive B cell activation and antibody production during chronic airway inflammation.

METHODS

We analysed B cells from NP or tonsil, or after ILC2 coculture, by flow cytometry. Antibody production from tissue was measured using Luminex assays and the frequency of antibody-secreting cells by ELISpot. Formation of B cell clusters was assessed using immunohistochemistry. Expression of genes associated with B cell activation and class switch recombination was measured by qRT-PCR.

RESULTS

NP contained significantly elevated frequencies of plasmablasts, especially those that expressed the extrafollicular marker Epstein-Barr virus-induced protein 2 (EBI2), but significantly fewer germinal centre (GC) B cells compared with tonsil. Antibody production and the frequency of antibody-secreting cells were significantly elevated in NP, and there was evidence for local class switch recombination in NP. Finally, ILC2s directly induced EBI2 expression on B cells in vitro.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data suggest there is a unique B cell activation environment within NP that is distinct from classic GC-mediated mechanisms. We show for the first time that ILC2s directly induce EBI2 expression on B cells, indicating that ILC2s may play an important role in B cell responses. B cell-targeted therapies may provide new treatment options for CRSwNP.

Selective expansion of human regulatory T cells in nasal polyps, and not adjacent tissue microenvironments, in individual patients exposed to steroids

Severe forms of chronic rhinosinusitis (CRS), a common upper airway inflammatory disorder, are associated with nasal polyps (NPs). NP disease is ameliorated by glucocorticoid (GC) treatment, whose cellular effects are poorly understood. We therefore assessed the influence of GC therapy on NPs in CRS patients, focusing on regulatory T (T_reg) cells. T_reg cell populations were analyzed by flow cytometry in NPs and control tissues from GC-treated CRS patients and controls. After GC exposure, selective expansion of T_reg cells was seen within NPs, and not blood or adjacent ethmoid tissues. To confirm direct GC effects, NPs from the same patients were biopsied prior to, and following, 1week of oral GC exposure. Direct expansion of Tregs into the same NP bed was detected in 4/4 CRS patients following GC exposure. T_reg cell spikes into NPs were secondary to cellular recruitment given limited Ki67 expression within these regulatory cells. Chemokine gene expression profiling identified several chemokines, notably CCL4, induced within NPs upon GC treatment. Neutralization of chemokine receptor/ligand interactions using CCR4 small molecule antagonists reduced T_reg migration towards GC-treated NPs in an ex vivo migration assay. Our findings suggest that the common use of GCs in the treatment of NP disease leads to recruitment of T_reg cells from peripheral sites into NP tissues, which may be critical to the anti-inflammatory effect of GCs. Mechanistically T_reg expansion appears to be conferred, in part, by chemokine receptor/ligand interactions induced following corticosteroid therapy.

Immunopathogenesis of Chronic Rhinosinusitis and Nasal Polyposis

Chronic rhinosinusitis (CRS) is a troublesome, chronic inflammatory disease that affects over 10% of the adult population, causing decreased quality of life, lost productivity, and lost time at work and leading to more than a million surgical interventions annually worldwide. The nose, paranasal sinuses, and associated lymphoid tissues play important roles in homeostasis and immunity, and CRS significantly impairs these normal functions. Pathogenic mechanisms of CRS have recently become the focus of intense investigations worldwide, and significant progress has been made. The two main forms of CRS that have been long recognized, with and without nasal polyps, are each now known to be heterogeneous, based on underlying mechanism, geographical location, and race. Loss of the immune barrier, including increased permeability of mucosal epithelium and reduced production of important antimicrobial substances and responses, is a common feature of many forms of CRS. One form of CRS with polyps found worldwide is driven by the cytokines IL-5 and IL-13 coming from Th2 cells, type 2 innate lymphoid cells, and probably mast cells. Type 2 cytokines activate inflammatory cells that are implicated in the pathogenic mechanism, including mast cells, basophils, and eosinophils. New classes of biological drugs that block the production or action of these cytokines are making important inroads toward new treatment paradigms in polypoid CRS.

Canonical Wnt Signaling Drives Tumor-Like Lesions from Sox2-Positive Precursors of the Murine Olfactory Epithelium

Canonical Wnt signaling is known to promote proliferation of olfactory stem cells. In order to investigate the effects of a constitutive activation of Wnt signaling in Sox2-positive precursor cells of the olfactory epithelium, we used transgenic mice that allowed an inducible deletion of exon 3 of the Ctnnb1 gene, which is responsible for the phosphorylation and degradation of Ctnnb1 protein. After induction of aberrant Wnt activation by Ctnnb1 deletion at embryonic day 14, such mice developed tumor-like lesions in upper parts of the nasal cavity. We still observed areas of epithelial hyperplasia within the olfactory epithelium following early postnatal Wnt activation, but the olfactory epithelial architecture remained unaffected in most parts when Wnt was activated at postnatal day 21 or later. In summary, our results suggest an age-dependent tumorigenic potential of aberrant Wnt signaling in the olfactory epithelium of mice.

Innate lymphoid type 2 cells in chronic rhinosinusitis

PURPOSE OF REVIEW

Innate lymphoid type 2 cells (ILC2) have a critical role in the initiation and regulation of type 2 immune responses and are recognized as an important source of type-2 cytokines. Here, we present recent findings of the role of ILC2 in the integration, processing, and coordination of innate and adaptive immune processes and focus on the potential role of ILC2 in the context of chronic rhinosinusitis.

RECENT FINDINGS

Recent research has shown the complex crosstalk that occurs between ILC2 and different innate and adaptive immune cell types with a critical role for ILC2 not only in mounting type 2 immune responses at barrier surfaces, but also in tissue repair responses and normal homeostatic functions. ILC2 research in a disease context has brought important insights in particular in the context of allergic inflammatory diseases, emphasizing a critical role for ILC2 and in particular ILC2-derived IL-13 in diseases of the upper and lower airways such as asthma.

SUMMARY

The identification and characterization of ILC2 in the context of health and disease have brought a wealth of new knowledge into the mechanisms of type 2 immune responses. This is relevant to diverse disorders, including asthma, chronic rhinosinusitis, atopic dermatitis, fibrosis, helminth repulsion, and obesity.

Differential short palate, lung, and nasal epithelial clone 1 suppression in eosinophilic and noneosinophilic chronic rhinosinusitis with nasal polyps: implications for pathogenesis and treatment

PURPOSE OF REVIEW

Short palate, lung, and nasal epithelial clone 1 (SPLUNC1) is an epithelium-secreted protein that is involved in innate immunity. A protective role for SPLUNC1 in lower respiratory inflammation and chronic rhinosinusitis (CRS) has recently been recognized.

RECENT FINDINGS

An impaired epithelial immune barrier has been proposed to play a critical role in the pathogenesis of CRS. Recent research has demonstrated that SPLUNC1 is profoundly reduced in polyp tissues of CRS with nasal polyps (CRSwNP) compared with control tissues. Studies investigating the differential expression of SPLUNC1 in eosinophilic and noneosinophilic CRSwNP have been published. Nasal SPLUNC1 expression was inhibited by Th2 cytokines (IL-4 and IL-13) but was stimulated by toll-like receptor (TLR) agonists and glucocorticoids. Decreased SPLUNC1 expression in the sinus mucosa is associated with positive Pseudomonas aeruginosa bacterial colonization and poor surgical outcomes in CRS patients.

SUMMARY

These studies identify the role of SPLUNC1 in sinonasal innate immunity and the pathogenesis of CRS. Defective expression of SPLUNC1 in CRSwNP patients may lead to insufficient maintenance of the epithelial barrier function and enhanced bacterial colonization. The use of SPLUNC1 as a therapeutic target for CRSwNP remains to be determined.

Regulation of airway inflammation by Siglec-8 and Siglec-9 sialoglycan ligand expression

PURPOSE OF REVIEW

Inflammatory cells involved in the allergic response, including eosinophils, mast cells, basophils, and neutrophils, express sialoglycan-binding proteins such as Siglec-8 and Siglec-9, which inhibit cell function and survival. The purpose of this review is to briefly discuss the biology of these siglecs and their ligands and consider their potential impact in pathology and treatment of chronic rhinosinusitis (CRS).

RECENT FINDINGS

Recent studies demonstrate the presence of ligands for Siglec-8 and Siglec-9 in sinonasal tissue from patients with CRS as well as healthy patients, suggesting that the immunoregulatory functions of siglecs may be triggered in sinus tissue in health and disease.

SUMMARY

Ligands for Siglec-8 and Siglec-9 may regulate the function of eosinophils, mast cells, neutrophils, and other cells in sinus mucosa. Therapeutic strategies that activate the anti-inflammatory effects of siglecs may dampen inflammation and disease in CRS patients.

Group 2 innate lymphoid cells are increased in nasal polyps in patients with eosinophilic chronic rhinosinusitis

ILC2s represent a critical innate cellular source of type 2 cytokines and may play important roles in various diseases. We examined the role of ILC2s in the pathogenesis of two subgroups of CRSwNP: ECRS and non-ECRS. We analyzed the prevalence of ILC2s in sinonasal tissues and in blood from patients with ECRS, non-ECRS, CRSsNP, and control. The prevalence of ILC2s in nasal tissues was higher in patients with ECRS as compared to those with non-ECRS or CRSsNP. The prevalence of blood ILC2s was not different between patients with ECRS and non-ECRS. The prevalence of blood ILC2s was higher in patients with allergic rhinitis and elevated serum IgE levels. Alternaria-induced IL-33 secretion was increased in nasal epithelial cells derived from patients with ECRS as compared to those from patients with non-ECRS or CRSsNP. ILC2s may be involved in the pathogenesis of CRSwNP, in particular in patients with tissue eosinophilia (i.e., ECRS).

Hyaluronan synthases and hyaluronidases in nasal polyps

Nasal polyps (NPs) are benign lesions of nasal and paranasal sinuses mucosa affecting 1-4 % of all adults. Nasal polyposis affects the quality of patient's life as it causes nasal obstruction, postnasal drainage, purulent nasal discharge, hyposmia or anosmia, chronic sinusitis, facial pain and snoring. Without treatment, the disease can alter the craniofacial skeleton in cases of extended growth of polyps. The development of NPs is caused by the hyperplasia of nasal or paranasal sinuses mucosa, and edema of extracellular matrix. This is usually the result of high concentration of high molecular mass hyaluronan (HA) which is either overproduced or accumulated from blood supply. The size of HA presents high diversity and, especially in pathologic conditions, chains of low molecular mass can be observed. In NPs, chains of about 200 kDa have been identified and considered to be responsible for the inflammation. The purpose of the present study was the investigation, in NPs and normal nasal mucosa (NM), of the expression of the wild-type and alternatively spliced forms of hyaluronidases, their immunolocalization, and the expression of HA synthases to examine the isoform(s) responsible for the increased amounts of HA in NPs. Hyaluronidases' presence was examined on mRNA (RT-PCR analysis) and protein (immunohistochemistry) levels. Hyaluronan synthases' presence was examined on mRNA levels. Hyaluronidases were localized in the cytoplasm of epithelial and inflammatory cells, as well as in the matrix. On mRNA level, it was found that hyal-1-wt was decreased in NPs compared to NM and hyal-1-v3, -v4 and -v5 were substantially increased. Moreover, HAS2 and HAS3 were the only hyaluronan synthases detected, the expression of which was almost similar in NPs and NM. Overall, the results of the present study support that hyaluronidases are the main enzymes responsible for the decreased size of hyaluronan observed in NPs; thus they behave as inflammatory agents. Therefore, they could be a potential target for the design of a more advanced treatment for nasal polyposis.

Immune Mechanisms of Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a common inflammatory disease that results in a significant decrease in patient quality of life and a large economic burden. However, the lack of population-based epidemiologic studies and robust model systems has made it difficult to fully elucidate the key inflammatory pathways that drive the chronic inflammatory responses observed in CRS. This review will highlight the wide variety of factors that likely contribute to CRS disease pathogenesis. Defects in the innate immune function of the airway epithelium, including decreases in barrier function, mucociliary clearance, and production of antimicrobial peptides, all likely play a role in the initial inflammatory response. Subsequent recruitment and activation of eosinophils, mast cells, and innate lymphoid cells (ILCs) further contributes to the chronic inflammatory response and directly activates adaptive immune cells, including T and B cells. However, development of new tools and model systems is still needed to further understand the chronicity of this inflammatory response and which specific factors are necessary or sufficient to drive CRS pathogenesis. Such studies will be critical for the development of improved therapeutic strategies aimed at treating this highly prevalent and costly disease.

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

RATIONALE

The mechanisms that underlie the pathogenesis of chronic rhinosinusitis without nasal polyps (CRSsNP), chronic rhinosinusitis with nasal polyps (CRSwNP), and aspirin-exacerbated respiratory disease (AERD) are not clear.

OBJECTIVES

To first evaluate the inflammatory profiles of CRSsNP and CRSwNP tissues and then to investigate whether clinical differences observed between CRSwNP and AERD are in part secondary to differences in inflammatory mediator expression within nasal polyp (NP) tissues.

METHODS

Expression levels of numerous inflammatory mediators were determined by quantitative real-time polymerase chain reaction, ELISA, and multiplex immunoassay.

MEASUREMENTS AND MAIN RESULTS

CRSwNP NP had increased levels of type 2 mediators, including IL-5 (P < 0.001), IL-13 (P < 0.001), eotaxin-2 (P < 0.001), and monocyte chemoattractant protein (MCP)-4 (P < 0.01), compared with sinonasal tissue from subjects with CRSsNP and control subjects. Expression of IFN-γ messenger RNA or protein was low and not different among the chronic rhinosinusitis subtypes examined. Compared with CRSwNP, AERD NP had elevated protein levels of eosinophil cationic protein (ECP) (P < 0.001), granulocyte-macrophage colony-stimulating factor (GM-CSF) (P < 0.01), and MCP-1 (P = 0.01), as well as decreased gene expression of tissue plasminogen activator (tPA) (P = 0.02). Despite the higher eosinophilia in AERD, there was no associated increase in type 2 mediator protein levels observed.

CONCLUSIONS

CRSwNP was characterized by a predominant type 2 inflammatory environment, whereas CRSsNP did not reflect a classic type 1 milieu, as has been suggested previously. AERD can be distinguished from CRSwNP by elevated ECP levels, but this enhanced eosinophilia is not associated with elevations in traditional type 2 inflammatory mediators associated with eosinophil proliferation and recruitment. However, other factors, including GM-CSF, MCP-1, and tPA, may be important contributors to AERD pathogenesis.

Clinical and biological markers of difficult-to-treat severe chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease of the upper airways of which two major phenotypes exist, CRS without nasal polyps (CRSsNP) and CRS with nasal polyps (CRSwNP). Some patients with CRS have suboptimal response to current guideline treatments. These patients remain severe and uncontrolled by treatment and have a poor quality of life. It is highly important to identify both clinical and biological markers, so-called biomarkers, in this subset of patients. The presence of nasal polyps and comorbidity with asthma and with aspirin-exacerbated respiratory disease (AERD) are the most common clinical traits that have been associated to difficult-to-treat severe CRS. In addition to clinical traits, numerous biological markers, with known etiopathogenic roles in CRS, have been associated to difficult-to-treat or recalcitrant CRS. This review summarizes the existing knowledge of the clinical and biological markers associated to difficult-to-treat or uncontrolled severe CRS.