The characterization of IL-17A expression in patients with chronic rhinosinusitis with nasal polyps

Immune endotyping and gene expression profile of patients with chronic rhinosinusitis with nasal polyps in the aspirin-exacerbated respiratory disease (AERD) and the non-AERD subgroups

BACKGROUND

Chronic Rhinosinusitis (CRS) is a paranasal sinus inflammatory disease and is divided into two subgroups defined as CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). CRSwNP displays a T helper (Th)2 biased phenotype, and based on sensitivity or tolerance to aspirin or non-steroidal anti-inflammatory drugs (NSAID), is further subdivided into Aspirin-exacerbated respiratory disease (AERD) and non-AERD groups. Considering the challenge of diagnosis and treatment in patients with CRSwNP, particularly the AERD subtype, and the significance of endotyping in these patients, we examined the immune profile and endotyping based on gene expression analysis in the AERD and the non-AERD groups of patients with CRSwNP.

MATERIAL AND METHOD

In this study, 21 patients were enrolled and were categorized into AERD (N = 10) and non-AERD (N = 11) groups based on their sensitivity to aspirin. After the special washing period, nasal polyps were biopsied in both groups, and the infiltration of eosinophils, neutrophils, plasma cells, and lymphocytes was compared between the AERD and the non-AERD groups. Also, gene expression levels of transcription factors including Tbet, GATA3, RoRγt, and FoxP3 and inflammatory cytokines including interleukin (IL)1β, IL1RAP (IL1 receptor accessory protein), IL2, IL4, IL5, IL10, IL13, IL17, TNFα, and IFNγ were investigated by quantitative Real-time PCR (qRT-PCR). Statistical analyses were performed using analytical tests including Kolmogorov-Smirnov, Mann-Whitney, and T-test. A P value less than 0.05 was considered statistically significant.

RESULTS

The mean ± SD age of the studied groups was 37 ± 8.7 years old (21-50) for the AERD, and 40.4 ± 7.7 years old (31-52) for the non-AERD. LMS/EPOS/SNOT scores and pulmonary function tests showed no difference between the two groups. Serum immunoglobulin E (IgE) levels were found to be higher in patients with AERD (p = 0.04), however, the peripheral blood counts of eosinophils were comparable in the two groups. In the histopathologic analysis, the AERD group showed higher percentages of eosinophils (p = 0.04), neutrophils (p = 0.04), and plasma cells (p = 0.04) than the non-AERD group. Additionally, the gene expression levels of GATA3 (p = 0.001), IL4 (p = 0.04), IL5 (p = 0.007), and IL17 (p = 0.03) were significantly higher in the AERD than the non-AERD groups.

CONCLUSION

Higher gene expression levels of GATA3, IL4, IL5, and IL17 were observed in the AERD group compared with the non-AERD group. These findings point to distinct patterns of inflammation in patients with AERD, with a predominance of Th2 inflammation.

Epidemiology and aetiology of chronic rhinosinusitis in Asia-A narrative review

BACKGROUND

Despite having a similar prevalence to Western populations, literature on chronic rhinosinusitis (CRS) in the Asian population is sparse. There is limited data on the epidemiology and aetiology of CRS in Asia.

OBJECTIVES

To review the current literature on the epidemiology and aetiology of CRS in Asia.

METHODS

This is a narrative review of published data on the epidemiology and aetiology of CRS. Studies on CRS in Asian countries, published in English and indexed on PubMed or Google Scholar were reviewed. Where available, data extracted included epidemiology, endotype and cytokine profiles and genetic profiles.

RESULTS AND CONCLUSION

The prevalence of CRS in Asia ranges widely from 2.1% to 28.4%. Type 2 inflammation has been reported in 5%-55% of Asian patients, with lower levels of Type 2 cytokines reported in head to head comparisons of Western versus Asian patients. Notably, there exists marked heterogeneity in criterion of the tissue eosinophilic infiltration for diagnosis of type 2 CRS. Our review suggests that differences in prevalence of CRS and proportion of eosinophilic CRS between Asia and Europe and the Americas requires further study. Large-scale Asian studies utilising standardised definitions are needed to bridge this gap. Head to head genetic and microbiomal analysis may also be useful in understanding differences in CRS between the Asian and Western populations.

Psoriasis and Systemic Inflammatory Disorders

Psoriasis is a representative inflammatory skin disease occupied by large surface involvement. As inflammatory cells and cytokines can systemically circulate in various organs, it has been speculated that psoriatic skin inflammation influences the systemic dysfunction of various organs. Recent updates of clinical studies and experimental studies showed the important interaction of psoriasis to systemic inflammatory diseases. Furthermore, the importance of systemic therapy in severe psoriasis is also highlighted to prevent the development of systemic inflammatory diseases. In this review, we introduced representative systemic inflammatory diseases associated with psoriasis and the detailed molecular mechanisms.

Classification of eCRS: Based on disease outcome or normal range?: Comment on Toro et al

Undoubtedly, there is a lack of unanimous histopathologic criteria to classify eosinophilic chronic rhinosinusitis (eCRS) worldwide. We read with great interest the recent constructive systematic review by Toro et al.(1). The authors stretched out the current knowledge on the methods of classifying eCRS to determine an optimal cut-off point. While the authors are to be congratulated for their comprehensive overview, a point regarding the disease recurrence as the most relevant parameter to divide eosinophilic and noneosinophilic inflammation in chronic rhinosinusitis (CRS) should be discussed. In order to contribute to an evidence-based standardization of cut-off point to classify eCRS, we would like to share our considerations and approaches in this comment.

IL-17A-producing sinonasal MAIT cells in patients with chronic rhinosinusitis with nasal polyps

BACKGROUND

Diverse immune cells contribute to the pathogenesis of chronic rhinosinusitis (CRS), an inflammatory disease of the nasal cavity and paranasal sinuses. However, whether mucosal-associated invariant T (MAIT) cells are present in human sinonasal tissues remains unclear. Furthermore, the characteristics of sinonasal MAIT cells have not been studied in patients with CRS.

OBJECTIVE

We investigated the phenotype, function, and clinical implications of MAIT cells in patients with CRS.

METHODS

Peripheral blood and sinonasal tissue were obtained from patients with CRS with (CRSwNP) or without nasal polyps (CRSsNP) and healthy controls. MAIT cells were analyzed by flow cytometry.

RESULTS

We found that MAIT cells are present in human sinonasal tissues from healthy controls and patients with CRS. The sinonasal MAIT cell population, but not peripheral blood MAIT cells, from patients with CRSsNP, noneosinophilic CRSwNP (NE-NP), or eosinophilic CRSwNP (E-NP) had a significantly higher frequency of activated cells marked by CD38 expression. In functional analysis, the sinonasal MAIT cell population from NE-NP and E-NP had a significantly higher frequency of IL-17A⁺ cells but lower frequency of IFN-γ⁺ or TNF⁺ cells than control sinonasal tissues. Furthermore, CD38 expression and IL-17A production by sinonasal MAIT cells significantly correlated with disease extent evaluated by the Lund-Mackay computed tomography score in patients with E-NP.

CONCLUSIONS

Sinonasal MAIT cells exhibit an activated phenotype and produce higher levels of IL-17A in patients with CRSwNP. These alterations are associated with the extent of disease in patients with E-NP.

Th17/1-Biased Inflammatory Environment Involved in the Response of Epithelial Cells to Antigen Stimuli in Nasal Polyps

Several studies showed that IL-17A was significantly increased in nasal polyps (NPs). However, the source and characteristics of IL-17A-producing cells in NPs were not fully understood. We isolated mononuclear cells from NPs and uncinate tissues and analyzed them using flow cytometry. The results indicated that IL-17A was increased in NP tissues compared to uncinate tissues. The main IL-17A-expressing cells were CD3⁺ T cells in NP tissues, including Th17 cells, Tc17 cells, and γδT17 cells. Not similar to those in uncinate tissues, the majority of Th17 cells highly coexpressed IFN-γ in NP tissues, such as Th17/1 cells, which highly expressed CXCR3, CCR6, RORγt, and T-bet. Furthermore, Th17/1-biased environment increased the response of nasal epithelial cells to bacterial and viral stimuli, implying that Th17/1 cells play a greater role in the pathological development of NPs than Th17 or Th1 cells.

Evaluation of Diffuse Type 2 Dominant or Eosinophilic Chronic Rhinosinusitis With Corticosteroid Irrigation After Surgical Neosinus Cavity Formation

Importance

Eosinophilic chronic rhinosinusitis (eCRS), contemporarily classified as diffuse type 2 dominant chronic rhinosinusitis (CRS), is characterized by eosinophil-dominant mucosal inflammation. Contemporary management of eCRS as an inflammatory airway condition is multimodal with corticosteroid irrigations after the surgical creation of a neosinus cavity.

Objectives

To assess long-term treatment outcomes in patients with primary diffuse type 2 CRS or eCRS receiving multimodal treatment.

Design, Setting, and Participants

A prospective cohort study of patients seen in a tertiary rhinology practice recruited from May 2010 to November 2018 was conducted. Follow-up duration was 12 months or more following endoscopic sinus surgery (ESS) with a neosinus cavity formed. Data analysis was performed from August to November 2020. Consecutive adult (≥18 years) patients diagnosed with primary diffuse type 2 dominant CRS or eCRS based on the European Position Paper on Rhinosinusitis and Nasal Polyps 2020 criteria were included. Type 2 inflammation was defined as more than 10 eosinophils per high-power field obtained from sinus mucosal biopsy and managed with neosinus cavity ESS and ongoing corticosteroid irrigations. Exclusion criteria were less than 12 months of follow-up and secondary CRS.

Interventions

Endoscopic sinus surgery with complete removal of intersinus bony partitions to create a neosinus cavity. Nasal irrigation (240 mL) with betamethasone, 1 mg, or budesonide, 1 mg, daily for 3 to 6 months after ESS and tapered to an as-needed basis (minimum, 2-3 per week).

Main Outcomes and Measures

Poor control was defined as polyp recurrence (polyp growth in >1 sinus area on a single side), use of long-term systemic therapy (biologic therapy or ≥3 consecutive months of oral corticosteroids), and revision surgery involving polypectomy. The disease in patients with no poor control criteria was defined as well controlled, and the disease in those with 1 or more criteria was considered poorly controlled. Maintenance medical therapy use and patient-reported outcomes based on the 22-item Sinonasal Outcomes Test for preoperative and last follow-up were collected.

Results

Of the 222 participants recruited with primary diffuse type 2 dominant CRS or eCRS and minimum of year of follow-up, 126 were men (56.8%). Mean (SD) age was 54.8 (13.6) years, and median (SD) follow-up was 2.2 (2.2) years. Of the 222 patients, 195 (87.8%) had well-controlled disease, 16 (7.2%) had polyp recurrence, 7 (3.2%) continued to receive long-term oral corticosteroid therapy, 5 (2.3%) received biologic therapy, and 8 (3.6%) underwent a revision polypectomy. Clinically meaningful change on the 22-item Sinonasal Outcomes Test and the nasal subdomain score was maintained at the last follow-up in 134 patients (67.0%). Poor disease control was not associated with poor adherence to irrigation use.

Conclusions and Relevance

The findings of this cohort study suggest that long-term disease control and reduction in symptom burden in patients with primary diffuse type 2 CRS or eCRS might be achieved when managed as an inflammatory disorder. Maintenance corticosteroid irrigations in the population examined appeared to be successfully self-tapered to disease activity.

Local IL-17 positive T cells are functionally associated with neutrophil infiltration and their development is regulated by mucosal microenvironment in nasal polyps

OBJECTIVE AND DESIGN

IL-17 plays essential roles in neutrophilic inflammation in the lower respiratory tract, however, the characteristics of local IL-17⁺ T cells in nasal inflammatory mucosa are not fully understood. We investigated the roles of IL-17⁺ T cells in regulating neutrophil infiltration and the effect of the mucosal microenvironment in modulating IL-17⁺ T cell differentiation in CRSwNP tissues.

SUBJECTS

47 polyp tissues from chronic rhinosinusitis with nasal polyps (CRSwNP) patients without corticosteroid therapy and 26 tissues from healthy mucosa were obtained.

METHODS

Immunohistochemistry and flow cytometry were used to analyze the neutrophil infiltration, local IL-17⁺ T cell subsets, as well as cytokine producing profiles of IL-17⁺ T cell; tissue homogenates were used to study neutrophil migration and IL-17⁺ T cell differentiation.

RESULTS

Increase of IL-17⁺ cells and IL-17⁺ T cell subsets was significant in polyp tissues versus controls, IL-17⁺ cell number was positively correlated with neutrophil infiltration; while homogenates from polyp tissues with high IL-17 promoted neutrophil migration in vitro. IL-17 response was found in polyp-derived T cells upon Staphylococcus aureus infection. IL-17⁺ T cells were also down-regulated in polyps from patients treated with glucocorticoid steroids, and exhibited poly-functionality patterns in polyp tissues. Finally, IL-17⁺ T cell differentiation could be induced by IL-23, and homogenates from polyps could enhance IL-17⁺ T cell development.

CONCLUSIONS

This study determined a functional association of IL-17⁺ T cells with neutrophils in CRSwNP, and revealed that polyp microenvironment could promote IL-17⁺ T cell differentiation, suggesting a potential feedback role for IL-17⁺ T cell development and local neutrophilic inflammation.

Interleukin-17A Expression Correlated with the Prognosis of Chronic Rhinosinusitis with Nasal Polyps and the Anti-Interleukin-17A Effect in a Murine Nasal Polyps Model

OBJECTIVE

To investigate the expression of interleukin-17A (IL-17A) in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and to analyze its effect on prognosis and to explore the role and mechanism of anti-IL-17A effect in vivo by establishing a murine nasal polyps (NP) model.

METHODS

Patients with CRSwNP who underwent endoscopic sinus surgery and matched control subjects were collected. We investigated IL-17A expression in human NP tissues using immunohistochemistry and analyzed their clinical features, including Lund-Mackay computed tomography scoring (LMCS) before surgery, Lund-Kennedy endoscopic scoring (LKES) before surgery (LKES B), LKES 6 months after surgery (LKES A), and reduction of LKES (LKES R). Then, after establishing the murine NP model to detect the expression and correlation of IL-17A and matrix metalloproteinase-9 (MMP-9) in nasal tissue, we studied nasal lavage fluid and serum by PCR and enzyme-linked immunosorbent assay in vivo. Anti-IL-17A treatment was administered in the murine NP model to confirm the function of IL-17A during the pathogenic processes.

RESULTS

IL-17A expression was upregulated in NP tissues from patients with CRSwNP compared with control subjects (p < 0.001). The number of IL-17A+ cells was significantly negatively correlated with LKES R in patients with CRSwNP (p < 0.01). However, there was no significant correlation between IL-17A and LMCS or LKES B (all p < 0.05). Further, IL-17A and MMP-9 were more abundant in nasal mucosa of the murine NP model compared with that of control mice (all p < 0.05), and severe polypoid lesions were apparently observed in murine NP models. Anti-IL-17A treatment downregulated the mRNA and protein expression of MMP-9 in nasal mucosa and reduced the number of polypoid lesions in the murine NP model (all p < 0.05).

CONCLUSION

Our results suggest that IL-17A plays a crucial role and may affect the prognosis of CRSwNP. Anti-IL-17A treatment may reduce the formation of polypoid lesions through inhibition of MMP-9 expression.

Chinese Society of Allergy and Chinese Society of Otorhinolaryngology-Head and Neck Surgery Guideline for Chronic Rhinosinusitis

The current document is based on a consensus reached by a panel of experts from the Chinese Society of Allergy and the Chinese Society of Otorhinolaryngology-Head and Neck Surgery, Rhinology Group. Chronic rhinosinusitis (CRS) affects approximately 8% of Chinese adults. The inflammatory and remodeling mechanisms of CRS in the Chinese population differ from those observed in the populations of European descent. Recently, precision medicine has been used to treat inflammation by targeting key biomarkers that are involved in the process. However, there are no CRS guidelines or a consensus available from China that can be shared with the international academia. The guidelines presented in this paper cover the epidemiology, economic burden, genetics and epigenetics, mechanisms, phenotypes and endotypes, diagnosis and differential diagnosis, management, and the current status of CRS in China. These guidelines-with a focus on China-will improve the abilities of clinical and medical staff during the treatment of CRS. Additionally, they will help international agencies in improving the verification of CRS endotypes, mapping of eosinophilic shifts, the identification of suitable biomarkers for endotyping, and predicting responses to therapies. In conclusion, these guidelines will help select therapies, such as pharmacotherapy, surgical approaches and innovative biotherapeutics, which are tailored to each of the individual CRS endotypes.

Role of IL-17A in Chronic Rhinosinusitis With Nasal Polyp

Purpose

Th17-associated inflammation is increased in chronic rhinosinusitis with nasal polyp (CRSwNP), and is associated with disease severity and steroid resistance. Overexpressed interleukin (IL)-17A affects CRSwNP by tissue remodeling, eosinophilic accumulation, and neutrophilic infiltration. We aimed to identify the role of IL-17A in CRSwNP and to evaluate the effects of anti-IL-17A blocking antibody on nasal polyp (NP) formation using a murine NP model. Moreover, we sought to investigate whether the inhibition of mechanistic target of the rapamycin (mTOR) signal pathway could suppress IL-17A expression and NP formation.

Methods

Human sinonasal tissues from control subjects and patients with chronic rhinosinusitis (CRS) were analyzed using immunohistochemistry (IHC) and immunofluorescence staining. The effects of IL-17A neutralizing antibody and rapamycin were evaluated in a murine NP model. Mouse samples were analyzed using IHC, quantitative real-time polymerase chain reaction, and enzyme-linked immunosorbent assay.

Results

IL-17A⁺ inflammatory cells were significantly increased in number in NP from patients with CRSwNP compared to that in uncinate process tissues from control subjects and patients with CRS without NP or CRSwNP. CD68⁺ M1 macrophages dominantly expressed IL-17A, followed by neutrophils and T helper cells, in NP tissues. Neutralization of IL-17A effectively reduced the number of NPs, inflammatory cytokines, and IL-17A-producing cells, including M1 macrophages. Inhibition of IL-17A via the mTOR pathway using rapamycin also attenuated NP formation and inflammation in the murine NP model.

Conclusions

IL-17A possibly plays a role in the pathogenesis of CRSwNP, the major cellular source being M1 macrophage in NP tissues. Targeting IL-17A directly or indirectly may be an effective therapeutic strategy for CRSwNP.

Differences in Expression of Inflammatory Mediator in Mucosal and Polyp Tissue between Chronic Rhinosinusitis and Recurrent Chronic Rhinosinusitis

BACKGROUND:

Chronic rhinosinusitis with nasal polyps (CRSwNP) remains a challenging clinical entity with its propensity for recurrence. This disease decreases the patients’ quality of life and creates a high economic burden. An effort to investigate the aetiology of recurrent polyps has to be more alert.

AIM:

This study aims to prove the differences in expression of IL-5, IL-8, IL-17A and TGF-β1 in mucosal and polyp tissue between CRSwNP and recurrent CRSwNP and also to determine which expression of cytokines that have the main role in mucosal and polyp tissue in recurrent CRSwNP.

MATERIAL AND METHODS:

An observational study was conducted with a comparative cross-sectional design of CRS patients with 15 recurrent CRSwNP and CRSwNP who had never undergone surgery for as many as 15 polyps. Mucosal specimens of nasal polyps are taken by brushing, and polyp tissue specimens are taken during surgical removal of nasal polyps. Specimens from the polyp mucosa were examined by ELISA while the polyp tissue specimens were carried out immunohistochemistry (IHC).

RESULTS:

The result showed that there is a significant difference in IL-5 expression in the polyp mucosal between CRSwNP with recurrent CRSwNP, where expression is higher in recurrent CRSwNP. The expression of IL-8, IL-17 and TGF-β1 were lower in recurrent CRSwNP, but the difference was not significant. In nasal polyp tissue, there is a significant difference in TGF-β1 and IL-8 expression between CRSwNP and recurrent CRSwNP, where the expression of both cytokines is lower in recurrent CRSwNP. Interleukin-5 expression was higher in recurrent CRSwNP than CRSwNP, but the difference was not significant. In the polyps mucosal, IL-5 has the main role in recurrent CRSwNP polyp, whereas TGF-β has the main role in polyp tissue.

CONCLUSION:

This study concluded that the expression of IL-5 in the mucosa could be examined with simple techniques like brushing before polypectomy or FESS was performed to determine the possibility of polyps recurrencies.

Association of Inflammation Mediator in Mucosal and Tissue of Chronic Rhinosinusitis with Recurrent Nasal Polyp

BACKGROUND:

Chronic rhinosinusitis with polyps (CRSwNP) have a high risk of recurrence and patients often experience repeated surgery. There are several types of inflammatory patterns in CRSwNP, such as Th2 inflammation (eosinophilic) and Th1/Th17 inflammation (neutrophilic).

AIM:

This study aims to determine the expression of IL-5, IL-8, IL-17A and TGF-β in recurrent CRSwNP using the most convenient and non-invasive examination tool such as brushing the mucosal polyp and find out its correlation with polyp tissues.

MATERIAL AND METHODS:

A cross-sectional comparative study was carried out on 15 samples of mucosal brushing and polyp tissue. Expressions of IL-5, IL-8, IL-17A and TGF-β on mucosa were measured using the Enzyme-Linked Immunosorbent Assay (ELISA) examination and tissues using Immunohistochemical (IHC) examination.

RESULT:

The result showed that Only IL-5 has a significant relationship between mucosa and tissue with moderate positive correlation (p < 0.05; r = 0.527).

CONCLUSION:

This study concluded that mucosa brushing could be used as a simple and non-invasive examination to observe the expression of IL-5 in recurrent CRSwNP. IL-5 is one of the cytokines that mark the Th2 (eosinophilic) inflammatory pattern where eosinophilic polyps are closely related to recurrence.

Tc17/IL-17A Up-Regulated the Expression of MMP-9 via NF-κB Pathway in Nasal Epithelial Cells of Patients With Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a common chronic inflammatory disease of the upper airways involving nasal cavity and sinus. Deriving both from its clinical complexity with protean clinical manifestations as well its pathogenetic heterogeneity, the molecular mechanisms contributing to the pathogenesis of CRS remain unclear, and attract a wide interest in the field. Current evidences indicate that IL-17A is highly expressed in chronic rhinosinusitis with nasal polyps (CRSwNP). However, its pathogenetic role in regulation of tissue remodeling of CRSwNP remains unknown. The present study aimed to investigate the cellular origins and functions of IL-17A cytokine in CRSwNP, and further determined whether IL-17A could affect the expression of metalloproteinases (MMPs), the remodeling factors of CRSwNP. The results showed that the expression of IL-17A was upregulated in nasal tissues of patients with CRSwNP compared to those with chronic rhinosinusitis without nasal polyps (CRSsNP) and controls. CD8⁺ cytotoxic T lymphocytes (Tc) were major IL-17A producers in nasal tissues of CRSwNP. Interleukin (IL)-17-producing CD8⁺ T cells (Tc17) was significantly higher in nasal tissues of CRSwNP than CRSsNP and controls. Nonetheless, no difference was observed among the IL-17A in peripheral blood lymphocytes of these three groups. Moreover, in the same patients, IL-17A expression was negligible in lymphocytes of peripheral blood when compared with nasal tissues. Increased gene and protein expression of MMP-7 and MMP-9 in patients with CRSwNP compared with controls were observed. In CRSwNP samples, IL-17A receptor (IL-17AR) co-localized with MMP-9 and they were mainly expressed in the epithelial cells. MMP-9 expression was up-regulated both in Primary human nasal epithelial cells (PHNECs) and a nasal epithelial cell line (RPMI 2650) by IL-17A treatment, and diminished by anti-IL-17AR treatment. Furthermore, IL-17A promoted the expression of MMP-9 by activating the NF-κB signal pathway. Thus, our results have revealed a crucial role of IL-17A and Tc cells on pathogenesis and tissue remodeling of CRSwNP.

Endotypes of Chronic Rhinosinusitis Across Ancestry and Geographic Regions

PURPOSE OF REVIEW

Preliminary studies have suggested differences in endotypes of chronic rhinosinusitis (CRS) across ancestry/ethnic groups. Eosinophilic CRS (ECRS) is the predominant subtype for Western/European ancestry CRS patients and non-eosinophilic CRS (nECRS) for Asian patients. This review aims to re-analyze CRS endotypes across ancestry populations using one consistent criteria to existing data.

RECENT FINDINGS

Although tissue eosinophilia is the most commonly used criterion for ECRS, various cut-off points are suggested. Surrogate markers have been extensively studied. Sixty-six cohorts with study criteria were included with a total of 8557 patients. Raw data from 11 studies 544 patients were re-analyzed using number of tissue eosinophils. At lower cut-off values of ≥ 5 and ≥ 10 cells/HPF, most patients of Asian and Western/European ancestry were classified as ECRS without difference. In contrast, at cut-off points of ≥ 70 and ≥ 120 cells/HPF, the majority of both groups became reclassified as nECRS. After applying one consistent criteria to existing data, differences across ancestry and geographic populations in endotypes of CRS were no longer evident.

A possible role of stem cells in nasal polyposis

Since its discovery, the understanding of stem/progenitor cells raised dramatically in the last decade. Their regenerative potential is important to develop new therapeutic applications, but the identification advanced much faster than our understanding of stem/progenitor cells. In nasal polyposis, little is known about stem cells/progenitor cells and their ability. However, the further characterization of stem cells/progenitor cells may provide new treatment options for combating nasal polyposis. This review highlights the knowledge of the current literature about stem cells/progenitor cells in nasal polyposis and how this may be exploited in the development of novel treatment strategies.

Hypoxia regulates IL-17A secretion from nasal polyp epithelial cells

Hypoxia creates a microenvironment conducive to polypogenesis by regulating immune responses of the nasal polyp (NP) epithelium. We explored the immunocompetence of NP and control epithelial cells in response to hypoxia, to investigate potential relationships with polypogenesis. Three groups of tissue samples were collected: inferior turbinate (IT)and NP from individuals with chronic rhinosinusitis with NPs (CRSwNP), and control IT. A positive relationship was detected between HIF1α, HIF2α protein expression in epithelial cells and endoscope score in NP samples, while there was a negative correlation between HIF1α expression and degree of eosinophil infiltration. Epithelial IL-17A expression was lower in NPs than in IT samples from either controls or patients with CRSwNP. Primary human nasal epithelial cells were cultured under hypoxic or normoxic conditions. Enzyme-linked immunosorbent assays demonstrated decreased IL-17A expression upon prolonged exposure to hypoxia in both IT and NP samples from patients with CRSwNP, while IL-17A increased in control IT epithelial cells; correlation and time-dependency were observed between HIF1α and IL-17A expression in both IT and NP samples from patients with CRSwNP. These observations suggest that hypoxia is involved in the pathogenesis of NPs through regulation of IL-17A secretion and HIF1α and HIF2α expression in the NP epithelium.

Asthma associated with chronic rhinosinusitis: a population-based study

BACKGROUND

Few studies have investigated the relationship between asthma and chronic rhinosinusitis (CRS). The present study investigated the association between asthma and the risk of CRS in a large national sample.

METHODS

Patients newly diagnosed with asthma (International Classification of Diseases, Ninth Revision [ICD-9], Clinical Modification code 493) between 2000 and 2008 were identified from the Taiwan National Health Insurance Research Database. The cases were compared with sex-, age-, residence-, and insurance premium-matched controls, and both groups were followed until the end of 2009 for incidences of CRS with or without nasal polyps (CRSwNP or CRSsNP, respectively). Competing risk-adjusted Cox regression analyses were performed after adjustment for sex, age, residence, insurance premium, steroid use, hyperlipidemia, diabetes, hypertension, coronary artery disease, Charlson comorbidity index score, and mortality. We also performed a case-control study to determine the association between asthma and CRS.

RESULTS

The cohort study analysis examined 81,462 patients with a mean ± standard deviation (SD) follow-up period of 5.8 ± 2.4 years. Asthma was an independent predictor of CRSsNP (hazard ratio = 2.58; 95% confidence interval [CI], 2.20 to 3.03; p < 0.001) in the fully adjusted models. In the case-control analysis, both CRSwNP and CRSsNP were associated with asthma in the fully adjusted models.

CONCLUSION

Asthma was associated with increased risks of CRSwNP and CRSsNP, independent of several potential confounding factors.

Role of atopy in chronic rhinosinusitis with nasal polyps: does an atopic condition affect the severity and recurrence of disease?

BACKGROUND

The role of atopy in chronic rhinosinusitis is unclear: it is particularly controversial in chronic rhinosinusitis with nasal polyps.

METHODS

A prospective study of 210 patients with chronic rhinosinusitis with nasal polyps was performed. Patient demographics, visual analogue scale scores, Lund-Kennedy endoscopy scores, Lund-Mackay computed tomography scores, serum total immunoglobulin E levels, serum eosinophil cationic protein (ECP) levels and Phadiatop test findings were analysed.

RESULTS

There were no significant differences in age, sex, visual analogue scale score, Lund-Mackay computed tomography score, total serum immunoglobulin E level, serum ECP level or Phadiatop test results between patients with primary and recurrent chronic rhinosinusitis with nasal polyps. A total of 99 patients (47 per cent) had positive atopy tests. No significant differences in sex, visual analogue scale score, Lund-Kennedy endoscopy score, Lund-Mackay computed tomography score or recurrence rates were found between atopic and non-atopic patients; however, atopic patients were significantly younger than non-atopic patients. Atopy status did not correlate with disease severity.

CONCLUSION

There was no association between atopy status and either disease severity or recurrence in patients with chronic rhinosinusitis with nasal polyps, although atopic patients were younger than non-atopic patients.

T regulatory and Th17 cells in chronic rhinosinusitis with polyps

BACKGROUND

Chronic rhinosinusitis (CRS) is categorized into 2 types based on the absence (CRSsNP) and presence of nasal polyps (CRSwNP). Although CRSsNP patients lack nasal polyps, the mucosa may show variable degrees of polypoid change. This raises the question of whether or not the classification system is an over simplification and that CRSsNP and CRSwNP only represent 2 phenotypic extremes along a broader spectrum of immunologically different disease processes. To investigate this, adaptive and innate immune cells were compared in the different tissue types within CRSsNP and CRSwNP patients.

METHODS

Tissue from 15 CRSwNP, 6 CRSsNP, and 8 healthy control patients was obtained prospectively. Nonpolypoid mucosa, polypoid tissues, and polyps were obtained at the time of endoscopic sinus surgery and analyzed using flow cytometry for various adaptive and innate immune cell subsets.

RESULTS

In the polyps from CRSwNP patients there were significantly more T regulatory (Treg) cells (12.86 ± 12.60 vs 2.83 ± 4.68) and Th17 cells (16.12 ± 11.75 vs 2.31 ± 2.13) compared to the polypoid tissue from CRSsNP patients. Cellular infiltrates in the nonpolypoid or polypoid mucosa of the different patient categories showed no difference in CRSwNP, CRSsNP and control groups.

CONCLUSION

This observational study identified an increase in Treg and Th17 cells in CRSwNP patients implying that these cells may be implicated in polyp development. Importantly it also identified a similar inflammatory infiltrate in nonpolyp or polypoid mucosa across control, CRSsNP, and CRSwNP groups inferring that polyps should be sampled when studying CRSwNP.

Th17 Cytokines Disrupt the Airway Mucosal Barrier in Chronic Rhinosinusitis

Cytokine mediated changes in paracellular permeability contribute to a multitude of pathological conditions including chronic rhinosinusitis (CRS). The purpose of this study was to investigate the effect of interferons and of Th1, Th2, and Th17 cytokines on respiratory epithelium barrier function. Cytokines and interferons were applied to the basolateral side of air-liquid interface (ALI) cultures of primary human nasal epithelial cells (HNECs) from CRS with nasal polyp patients. Transepithelial electrical resistance (TEER) and permeability of FITC-conjugated dextrans were measured over time. Additionally, the expression of the tight junction protein Zona Occludens-1 (ZO-1) was examined via immunofluorescence. Data was analysed using ANOVA, followed by Tukey HSD post hoc test. Our results showed that application of interferons and of Th1 or Th2 cytokines did not affect the mucosal barrier function. In contrast, the Th17 cytokines IL-17, IL-22, and IL-26 showed a significant disruption of the epithelial barrier, evidenced by a loss of TEER, increased paracellular permeability of FITC-dextrans, and discontinuous ZO-1 immunolocalisation. These results indicate that Th17 cytokines may contribute to the development of CRSwNP by promoting a leaky mucosal barrier.

Cytokine Patterns and Endotypes in Acute and Chronic Rhinosinusitis

Since rhinosinusitis is an inflammatory disease, cytokines as key regulators of inflammation play a central role in its pathophysiology. In acute rhinosinusitis, several proinflammatory cytokines of different types have been identified. Initial information about the involvement of the inflammasome in rhinosinusitis has been gained, but this area remains open for more detailed research. Although it has been accepted now that chronic rhinosinusitis (CRS) needs to be differentiated into CRS with and without nasal polyps, it has become clear that this distinction is insufficient to clearly define subgroups with uniform pathophysiology and cytokine patterns. While Th1-cytokines are mostly found in CRSsNP and Th2 cytokines in CRSwNP, there is a substantial overlap, and several other cytokines have also been detected. Attempts to identify CRS endotypes based on cytokines are ongoing but not yet generally accepted. Despite the central role of cytokines in rhinosinusitis, no specific cytokine-targeted therapies are currently available, and only very few studies have specifically addressed the effects of such biologicals in rhinosinusitis.

Th17 response and its regulation in inflammatory upper airway diseases

Allergic rhinitis (AR) and chronic rhinosinusitis (CRS) are two widely prevalent inflammatory diseases in the upper airways. T cell immunity has been suggested to play an important pathogenic role in many chronic inflammatory diseases including inflammatory upper airway diseases. Inappropriate CD4(+) T cell responses, especially the dysregulation of the Th1/Th2 balance leading to excessive Th1 or Th2 cell activation, have been associated with allergic rhinitis and chronic rhinosinusitis. Nevertheless, recent studies suggest that IL-17A and IL-17A-producing Th17 cell subset, a distinct pro-inflammatory CD4(+) T cell lineage, may also play an important role in the pathophysiology of inflammatory upper airway diseases. Th17 cells may promote both eosinophilic and neutrophilic inflammation in AR and CRS. In addition, a few, but accumulating evidence shows that the Th17 responses can be tightly regulated by endogenous and exogenous substances in the context of AR and CRS. This review discusses recent advances in our understanding of the expression and function of the Th17 response and its regulation in inflammatory upper airway diseases, and the perspective for future investigation and clinical utility.

Serum level of interleukin-21 is elevated in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is an inflammatory disease of the sinuses and mucosa with unclear pathogenesis. Interleukin (IL)-21 is mainly expressed in activated cluster of differentiation (CD)4(+) T cells and has potent regulatory effects on the immune system.

OBJECTIVE

This study is to determine whether IL-21 in the blood is correlated with CRS.

METHODS

The blood samples from CRS patients and normal controls were analyzed in correlation with clinical features. The eosinophil percentage was counted, and serum levels of total immunoglobulin E (IgE) and IL-21 were analyzed by enzyme-linked immunosorbent assay (ELISA). In addition, IL-21 and interferon (IFN)-γ secreted from stimulated peripheral blood mononuclear cells (PBMCs) were measured by ELISA, and their mRNA expression levels were analyzed by real-time quantitative polymerase chain reaction (RT-qPCR). Disease severity was scored based on computed tomography (CT) scan, nasal endoscopy, and global osteitis scoring scale (GOSS).

RESULTS

A total of 55 CRS and 37 healthy subjects were recruited. The average levels of serum total IgE were 20 kU/L in normal group, 290 kU/L in CRS with nasal polys (CRSwNP), and 187 kU/L in CRS without nasal polys (CRSsNP). IL-21 levels were 28 pg/mL in normal group, 54 pg/mL in CRSwNP, and 71 pg/mL in CRSsNP. Both IgE and IL-21 were significantly elevated in both CRS patient subgroups. However, no significant difference was found between these two patient subgroups. The serum IL-21 levels correlated well with the disease severity in the patients. In addition, the secreted IL-21 was enhanced significantly in the patient's PBMCs stimulated by phytohemagglutin (PHA).

CONCLUSION

IL-21 could be a target for diagnosis and treatment of CRS.

Increased IL-21 expression in chronic rhinosinusitis with nasalpolyps

BACKGROUND

IL-21 is a key cytokine for regulating B cell immunity, which is involved in several inflammatory conditions. This study sought to define a role for IL-21 in activated B lymphocytes and enhanced tissue eosinophilia in NP tissues during the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

NP and uncinate process tissues were collected from 64 CRSwNP patients, 25 CRSsNP patients, and 29 control subjects. IL-21 expression was examined using IHC staining, qRT-PCR, flow cytometry, and ELISA, and its clinical implication was evaluated. Moreover, the effects of IL-21 on B cell differentiation and Ig production in cultured NP cells were examined in vitro.

RESULTS

The mRNA and protein levels of IL-21 were significantly increased in polyp tissues compared with control tissues (P < 0.05). Polyp IL-21 level was significantly associated with polyp size, tissue eosinophilia and asthma comorbidity, and recurrence after surgery (P < 0.05). Both Th1 and Th17 cells were the main cellular sources of IL-21 in polyp tissues. The percentage of IL-21(+) CD4(+) cells was significantly higher in polyp tissues compared with control tissues and matched PBMCs (P < 0.01). Accordingly, the percentage of CD19(+) CD20(+/-) CD38(high) cells was significantly higher in polyp tissues compared with control tissues (P < 0.01). Moreover, recombinant IL-21 significantly increased the percentage of CD19(+) CD20(+/-) CD38(high) cells (plasmablasts) and IgG and IgA production in cultured NP cells in vitro (P < 0.05).

CONCLUSION AND CLINICAL RELEVANCE

Increased IL-21 level in polyp tissues was associated with disease severity, local B cell activation, and immunoglobulin production, suggesting that IL-21 might play an important role in promoting persistent mucosal inflammation in CRSwNP patients.

Phospholipase A2-dependent Release of Inflammatory Cytokines by Superantigen-Stimulated Nasal Polyps of Patients with Chronic Rhinosinusitis

Background

Chronic rhinosinusitis (CRS) is an inflammatory/allergic disease with unclear pathophysiology, but it has been linked to an imbalance in the production of eicosanoids, which are metabolites of arachidonic acid, and results from phospholipids hydrolysis by phospholipase A2 (PLA2). As of yet, the role of PLA2 in CRS has hardly been studied, except for a report that group II PLA2 expression is elevated in interleukin (IL) 1β or tumor necrosis factor α-stimulated CRS nasal tissues with and without polyps. The PLA2 families include extracellular (secretory) and intracellular isoforms, which are involved in the regulation of inflammatory processes in different ways. Here we comprehensively investigated the expression of PLA2s, particularly those reported to be involved in respiratory disorders, in superantigen (SAE)-stimulated nasal polyps from patients with CRS with polyps, and determined their role in inflammatory cytokine production by inhibition of PLA2 expression.

Methods

The release of IL-5, IL-13, IL-17, and interferon γ by nasal polyps dispersed cells (NPDC) was determined concomitantly with PLA2 messenger RNA expression, under SAE stimulation, with or without dexamethasone, as a regulator of PLA2 expression.

Results

Stimulation of NPDCs by SAE-induced cytokine secretion with enhanced expression of several secretory PLA2 and Ca2+-independent PLA2, while suppressing cytosolic PLA2 expression. All these were reverted to the level of unstimulated NPDCs on treatment with dexamethasone.

Conclusion

This study further supports the key role of secretory PLA2 in the pathophysiology of respiratory disorders and presents secretory PLA2 inhibition as a therapeutic strategy for the treatment of CRS and airway pathologies in general.

Increased expression of the epithelial anion transporter pendrin/SLC26A4 in nasal polyps of patients with chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is a multifactorial disease of unknown cause characterized by sinonasal inflammation, increased mucus production, and defective mucociliary clearance. Expression of Pendrin, an epithelial anion transporter, is increased in asthma and chronic obstructive pulmonary disease. Pendrin increases mucus production and regulates mucociliary clearance.

OBJECTIVES

We sought to investigate the expression of pendrin and the mucus-related protein Muc5AC in sinonasal tissues of control subjects and patients with CRS and to evaluate the regulation of pendrin expression in nasal epithelial cells (NECs) in vitro.

METHODS

The expression and distribution of pendrin in sinonasal tissues was analyzed by using real-time PCR, immunoblot analysis, and immunohistochemistry. Differentiated NECs were used to study the regulation of pendrin expression.

RESULTS

Increased pendrin expression was observed in nasal polyp (NP) tissue of patients with CRS. Immunohistochemistry analysis revealed that pendrin was largely restricted to the epithelial layer. Pendrin expression significantly correlated with inflammatory cell markers, suggesting that the factors made by these cells might induce pendrin expression. Furthermore, both pendrin and periostin levels (a biomarker in asthma) correlated with IL-13 levels, suggesting that pendrin can be induced by this cytokine in sinonasal tissues. Expression of the mucus component protein Muc5AC correlated weakly with pendrin expression, indicating that pendrin might modulate mucus production in NPs. In cultured NECs pendrin expression was induced by TH2 cytokines and induced synergistically when TH2 cytokines were combined with IL-17A. Interestingly, human rhinovirus had a potentiating effect on IL-13-induced pendrin expression. Dexamethasone suppressed pendrin expression, suggesting that the therapeutic benefit of dexamethasone in asthmatic patients and those with CRS might involve regulation of pendrin expression.

CONCLUSIONS

TH2-mediated pendrin expression is increased in NPs of patients with CRS and might lead to increased inflammation, mucus production, and decreased mucociliary clearance.

Impact of intraoperative hydrodebrider treatment on postoperative sinonasal inflammation

BACKGROUND

The impact of intraoperative hydrodebrider sinus irrigation (HSI) during endoscopic sinus surgery (ESS) on postoperative inflammation, endoscopy, and patient-reported outcomes has not been studied.

METHODS

A clinical trial of 12 patients with symmetric chronic rhinosinusitis were prospectively randomized to HSI on one side after undergoing bilateral ESS. The contralateral side was not treated with any irrigation and served as an internal control. Preoperative computed tomography, endoscopic, 22-item Sino-Nasal Outcome Test (SNOT-22), and symptom visual analog scale (VAS) scores for each side were obtained. At 1 and 3 months postsurgery, endoscopy, SNOT-22, and sinus VAS were recorded. Sinonasal mucus levels of interleukin (IL)-6, IL-10, IL-17a, and tumor necrosis factor (TNF) alpha were measured at the time of surgery, 1 and 3 months, postoperatively, from each side.

RESULTS

VAS scores improved on both sides (p < 0.05) and SNOT-22 improved at all postoperative time points (p < 0.05). Endoscopic scores of HSI-treated sides did not improve compared with baseline. HSI had no additional significant impact on postoperative VAS at any time point. HSI significantly decreased IL-17a levels when compared with the control side at 1 month (p = 0.034) and 3 months (p = 0.031). No significant change was seen in TNF-alpha, IL-6, or IL-10 on either side at any time point.

CONCLUSION

Intraoperative HSI at the time of ESS failed to establish any improvement in postoperative endoscopy or most local cytokine levels after ESS.

Interleukin-25 and Interleukin-33 as Mediators of Eosinophilic Inflammation in Chronic Rhinosinusitis

Background

The initiating mediators of T-helper 2 inflammation, often seen in eosinophillic chronic rhinosinusitis (CRS), remains poorly understood. Interleukin (IL) 25, IL-33, and thymic stromal lymphopoietin (TSLP) are epithelial-derived cytokines implicated in the initiation of T-helper 2 inflammation and eosinophilia in other diseases. The expression of these cytokines was compared with phenotypic and histopathologic markers to investigate the factors that may drive eosinophilic inflammation in CRS.

Method

Sinus mucosal samples from patients with CRS who were undergoing sinus surgery as part of their management were analyzed for IL-25, IL-33, and TSLP messenger RNA (mRNA) expression by quantitative polymerase chain reaction. Patients with tumor and who were undergoing surgery via an endonasal approach with normal sinus mucosa were controls. The mRNA expression was compared with CRS phenotype and histopathologic measures of eosinophilic inflammation. Immunohistochemical staining was used to confirm mRNA expression.

Results

Thirty-nine patients (mean ± standard deviation age; 48.2 ± 15.0 years, 38% women), 12 patients with CRS with nasal polyps, 20 patients with CRS without nasal polyps, and 7 controls were recruited. Higher IL-25 (p = 0.005) and IL-33 (p = 0.003) mRNA and protein expression was observed in patients with >10 eosinophil/hpf. TSLP showed no significant associations (p = 0.39). Similar overexpression was seen in eosinophilic dominated inflammation (IL-25, p = 0.01; IL-33, p = 0.02) and patients with greater inflammatory severity.

Conclusion

IL-25 and IL-33 overexpression was observed in eosinophilic CRS, The release of these cytokines by dysfunctional endothelium may perpetuate the eosinophillic inflammation in CRS.

Interleukin-17A-induced inflammation does not influence the development of nasal polyps in murine model

BACKGROUND

Nasal polyposis associated with chronic rhinosinusitis (CRS) is a chronic inflammatory disease that is characterized by infiltration of many inflammatory cells. Meanwhile, interleukin (IL)-17A is a well-known proinflammatory cytokine that induces both eosinophilic and neutrophilic inflammation. We investigated the role of IL-17A in the development of nasal polyps in the CRS murine model.

METHODS

Eosinophilic CRS with nasal polyps was induced by using ovalbumin (OVA) and Staphylococcus aureus enterotoxin B (SEB) in wild-type BALB/c and IL-17A knockout (KO) mice. Histopathologic changes of the sinonasal cavity were evaluated using hematoxylin and eosin, Periodic acid-Schiff, Sirius red, Masson's trichrome, and immunohistochemistry. The levels of total and OVA-specific immunoglobulin Es (IgEs) in sera were measured using enzyme-linked immunosorbent assay. The expression levels of IL-4, IL-5, and interferon-γ (IFN-γ) in the nasal mucosa were assessed by quantitative real-time polymerase chain reaction.

RESULTS

Under the IL-17A deficiency, total and OVA-specific IgEs in sera were reduced significantly. Infiltration of both eosinophils and neutrophils into the nasal mucosa, subepithelial fibrosis, and goblet cell count also decreased significantly in IL-17A KO mice treated with both OVA and SEB compared with those in the wild-type counterpart. However, there were no significant differences in the number of polypoid lesions among groups. Meanwhile, IL-4 increased and IFN-γ decreased in the nasal mucosa in IL-17A KO mice treated with both OVA and SEB.

CONCLUSION

This study suggests that even though IL-17A plays an important role in both nasal inflammation and remodeling, it does not influence the development of nasal polypoid lesions.

Cytokine crowdsourcing: multicellular production of TH17-associated cytokines

In the 2 decades since its discovery, IL-17A has become appreciated for mounting robust, protective responses against bacterial and fungal pathogens. When improperly regulated, however, IL-17A can play a profoundly pathogenic role in perpetuating inflammation and has been linked to a wide variety of debilitating diseases. IL-17A is often present in a composite milieu that includes cytokines produced by TH17 cells (i.e., IL-17F, IL-21, IL-22, and IL-26) or associated with other T cell lineages (e.g., IFN-γ). These combinatorial effects add mechanistic complexity and more importantly, contribute differentially to disease outcome. Whereas TH17 cells are among the best-understood cell types that secrete IL-17A, they are frequently neither the earliest nor dominant producers. Indeed, non-TH17 cell sources of IL-17A can dramatically alter the course and severity of inflammatory episodes. The dissection of the temporal regulation of TH17-associated cytokines and the resulting net signaling outcomes will be critical toward understanding the increasingly intricate role of IL-17A and TH17-associated cytokines in disease, informing our therapeutic decisions. Herein, we discuss important non-TH17 cell sources of IL-17A and other TH17-associated cytokines relevant to inflammatory events in mucosal tissues.

Interleukin-25 and mucosal T cells in noneosinophilic and eosinophilic chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease of uncertain pathogenesis. Memory T cells acquire additional functions during the secondary response and play important roles in chronic inflammation.

OBJECTIVE

To investigate characteristics of tissue memory CD4(+) T cells obtained from patients with noneosinophilic CRSwNP (NECRS) and eosinophilic CRSwNP (ECRS) by focusing on the influence of interleukin (IL)-25.

METHODS

Pro-allergic cytokines in tissue homogenates were measured using enzyme-linked immunosorbent assays. NP mononuclear cells and CD4(+) T cells were isolated from NPs from patients with CRSwNP. Cytokine expression and CD4(+) T-cell subpopulations were analyzed using enzyme-linked immunosorbent assay, flow cytometry, and real-time polymerase chain reaction.

RESULTS

The IL-25 level in NPs increased in patients with ECRS. IL-5 and IL-9 mRNA levels expressed by tissue CD4(+) T cells were significantly elevated in patients with ECRS. Most infiltrating CD4(+) T cells in ECRS and NECRS expressed CD45RO; however, regardless of the atopic status, high IL-17RB levels were detected in CD4(+) T cells from patients with ECRS. IL-17RB mRNA levels expressed by tissue CD4(+) T cells significantly correlated with the number of eosinophils in NPs. Elevation of IL-5 and IL-9 production was found in NP mononuclear cells from patients with ECRS, but not in those from patients with NECRS, by stimulation with IL-25 under T-cell receptor stimulation.

CONCLUSION

Interleukin-25 and a subpopulation of tissue T-helper type 2 and 9 cells that express increased IL-17RB levels could contribute to infiltration of eosinophils in NPs and could have produced the pathologic difference between NECRS and ECRS.

Role of the aryl hydrocarbon receptor in the pathogenesis of chronic rhinosinusitis with nasal polyps

A predominant Th17 population is a marker of chronic rhinosinusitis with nasal polyps (CRSwNP) in Chinese patients. As a ligand-activated transcription factor, the aryl hydrocarbon receptor (AhR) plays a vital role in promoting or inhibiting specific Th cell development. However, its role in CRSwNP remains to be defined. The aim of the present study was to investigate whether AhR, which regulates Th17 cell differentiation, played a role in the pathogenesis of CRSwNP by evaluating AhR expression in nasal polyps and peripheral blood mononuclear cells (PBMCs) obtained from CRSwNP patients. Forty-eight patients (atopic, 24; non-atopic, 24) and 13 controls were studied. To explore the role of AhR in CRSwNP, we analyzed the expression of AhR, retinoid-related orphan receptor C (RORC), interleukin (IL)-17, and IL-10 and the differentiation of Th17 using mRNA or protein detection methods. Notably, the expression of AhR was reduced in CRSwNP, and the expression of AhR was lower in the atopic group than in the non-atopic group. However, there was a very low level of Th17 and its associated factors (RORC, IL-17) in the control group compared to the two CRSwNP groups. In particular, the polarization of Th17 cells in atopic CRSwNP patients was increased compared with non-atopic individuals. In addition, ITE intervention in PBMCs promoted AhR expression and attenuated Th17 responses, demonstrating that AhR was more likely to suppress Th17 cells differentiation in Chinese CRSwNP patients. This information is valuable for obtaining a clear understanding of the pathogenesis of CRSwNP. Moreover, patients with atopic CRSwNP may exhibit reduced expression of AhR, leading to aggravation of the disproportionate distribution of Th17 cells in polyp tissues and PBMCs, thereby suggesting that atopic CRSwNP has a distinct pathogenesis from that of non-atopic CRSwNP.

Increased IL-22 level in allergic rhinitis significantly correlates with clinical severity

BACKGROUND

IL-22 regulates various processes and has been linked to diverse effects. However, the importance of IL-22 in the pathogenesis of allergic rhinitis (AR) remains poorly understood. This study sought to evaluate the levels of IL-22 and IL-17A in AR patients and their association with clinical severity ofN AR.

METHODS

Thirty-six AR patients and 22 normal controls were enrolled in this study. The frequencies of IL-22(+), IL-17A(+), and IL-9(+) T helper (Th) cells in peripheral blood of AR patients and normal controls were examined by flow cytometry. Serum levels of IL-22 and IL-17A in AR patients and normal controls were determined by ELISA. The clinical relevance of the percentages of IL-22(+) and IL-17A(+) Th cells as well as serum IL-22 and IL-17A levels were evaluated.

RESULTS

The frequencies of IL-22(+) and IL-17A(+) Th cells, but not IL-9(+) Th cells, were significantly increased compared with those in normal controls (p < 0.05). Frequencies of IL-22(+) and IL-17A(+) Th cells in peripheral blood of AR patients significantly correlated with visual analog scale scores of nasal symptoms (nasal congestion and rhinorrhea; p < 0.05). Moreover, the serum levels of IL-22 and IL-17A were significantly increased compared with those in normal controls (p < 0.05) and significantly correlated with the levels of Dermatophagoides pteronyssinus and Dermatophagoides farinae specific IgE in AR patients.

CONCLUSION

Our findings suggested that IL-22 as well as IL-17A may play an important role in the regulation of Th2-skewed inflammation in AR patients.

Increased level of interleukin-13, but not interleukin-4 and interferon-γ in chronic rhinosinusitis with nasal polyps

BACKGROUND

This study was performed to investigate the serum level of interleukin (IL)-13, IL-4, and interferon (IFN)-γ in chronic rhinosinusitis with nasal polyps (CRSwNP) and subsequent inflammation pattern and comorbidities including asthma and aspirin intolerance.

METHODS

A case-control study was conducted on 60 adult patients with CRSwNP with mean age of 37.7±12.7 (ranging from 18 to 70) years, and on 20 healthy controls. Serum levels of IL-13, IL-4, and IFN-γ were assessed, using enzyme-linked immunosorbent assay to be compared between case and control groups. Serum level of total immunoglobulin (Ig) E was also assessed in the patients with CRSwNP.

RESULTS

Serum level of IL-13 in the patients with CRSwNP was significantly higher than the controls (0.98±1.56 vs. 0.34±0.16 pg/ml, respectively, p=0.002). IL-4 and IFN-γ did not differ significantly between the two groups. Total IgE level was significantly increased in the patients with CRSwNP, compared to the normal values (301.43±516.54 IU/ml, p=0.033). Among the patients with CRSwNP, 12/60 (20%) had aspirin intolerance and 44/60 (73.3%) had asthma. IgE was also higher in asthmatics than non-asthmatics patients (364.9±586.6 vs. 126.7±135.7, respectively, p=0.015). Patients with aspirin intolerance had higher levels of IFN-γ (4.7±1.4 vs. 4.1±0.6, respectively, p=0.022).

CONCLUSIONS

IL-13 with high level of total IgE was observed in the patients with CRSwNP, which predisposes them to have concomitant asthma. IFN-γ seems to be down-regulated in the patients with CRSwNP, but could be over-expressed in the presence of aspirin intolerance.

Effects of IL-17 on expression of GRO-α and IL-8 in fibroblasts from nasal polyps

Recent studies indicated that interleukin (IL)-17, growth-related oncogene (GRO)-α and IL-8 play an important role in the pathogenesis of nasal polyps. However, the effects of the increased amount of IL-17 and the production of GRO-α and IL-8 in human nasal polyp fibroblasts are not completely understood. This study aimed to determine the effects of the increased IL-17 on the changes of GRO-α and IL-8 expression in human nasal polyp fibroblasts and further investigate the mechanism of neutrophil infiltration in nasal polyps. Nasal polyp fibroblasts were isolated from six cases of human nasal polyps, and the cells were stimulated with five different concentrations of IL-17. Real-time fluorescence quantitative polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of GRO-α and IL-8. The mRNA of GRO-α and IL-8 was expressed in unstimulated controls and remarkably increased by stimulation with IL-17. Moreover, the levels of GRO-α and IL-8 produced by fibroblasts were increased gradually with the increases in IL-17 concentrations. The present study showed that nasal fibroblasts can produce GRO-α and IL-8, and their production is remarkably enhanced by IL-17 stimulation, thereby clarifying the mechanism of the IL-17 mediated neutrophil infiltration in nasal polyps. These findings might provide a rationale for using IL-17 inhibitors as a treatment for nasal inflammatory diseases such as nasal polyps.

Lessons learned from mice and man: mimicking human allergy through mouse models

The relevance of using mouse models to represent human allergic pathologies is still unclear. Recent studies suggest the limitations of using models as a standard for assessing immune response and tolerance mechanisms, as mouse models often do not sufficiently depict human atopic conditions. Allergy is a combination of aberrant responses to innocuous environmental agents and the subsequent TH2-mediated inflammatory responses. In this review, we will discuss current paradigms of allergy - specifically, TH2-mediated and IgE-associated immune responses - and current mouse models used to recreate these TH2-mediated pathologies. Our overall goal is to highlight discrepancies that exist between mice and men by examining the advantages and disadvantages of allergic mouse models with respect to the human allergic condition.

Local expression of interleukin-17a is correlated with nasal eosinophilia and clinical severity in allergic rhinitis

Interleukin (IL)-17A is a major cytokine produced by Th17 cells, which are associated with chronic inflammations. The local expression of IL-17A in allergic rhinitis (AR) remains to be characterized. We sought to determine the role of IL-17A expression in human inferior turbinate mucosa in the pathophysiology of AR. Inferior turbinate mucosa was sampled from medical treatment–resistant, surgery-required patients with perennial AR (PAR, n = 21), nonallergic rhinitis with eosinophilia syndrome (NARES, n = 7), and nonallergic hypertrophic rhinitis (HR, n = 13). IL-17A expression was determined with immunohistochemical staining. The mean number of IL-17A⁺ cells and eosinophils per field were counted. Total serum immunoglobulin E (IgE) levels, blood eosinophil count, and forced expiratory volume in 1 second (FEV₁)/forced vital capacity (FVC) ratio were also examined in each patient. IL-17A was primarily expressed in infiltrating inflammatory cells. The number of IL-17A⁺ cells in nasal mucosa was significantly higher in the PAR group compared with HR (p = 0.002) and NARES (p = 0.021) groups. There was a significant and positive correlation between the number of IL-17A⁺ cells and total nasal symptom score (rho = 0.403; p = 0.011), especially sneezing score (rho = 0.471; p = 0.003). The number of IL-17A⁺ cells was significantly and positively correlated with the degree of eosinophil infiltration (rho = 0.623; p < 0.001), but not with total serum IgE levels (rho = 0.284; p = 0.098), blood eosinophil counts (rho = 0.302; p = 0.056), or FEV₁/FVC ratio (rho = 0.092; p = 0.569). The present study provides evidence that IL-17A expression in the nasal mucosa is associated with the pathophysiology of AR, including disease severity and nasal eosinophilia.

Immunomodulatory Effect of Mesenchymal Stem Cells on T Lymphocyte and Cytokine Expression in Nasal Polyps

OBJECTIVES

Adipose tissue-derived stem cells (ASCs) have been reported to have immunomodulatory effects in various inflammatory diseases, including asthma and allergic rhinitis, through the induction of T cell anergy. Nasal polyps (NPs) are a chronic inflammatory disease in the nose and paranasal sinus characterized histologically by the infiltration of inflammatory cells, such as eosinophils or lymphocytes. This study was performed to investigate whether ASCs have immunomodulatory effects on T lymphocyte and cytokine expression in eosinophilic NPs.

STUDY DESIGN

Basic science experimental study.

SETTING

University tertiary care facility.

SUBJECTS AND METHODS

NP specimens were obtained from 20 patients with chronic rhinosinusitis and eosinophilic NPs. ASCs were isolated and cultured from the abdominal fat of 15 subjects undergoing intra-abdominal surgery. Infiltrating cells (1 × 10(6)) were isolated from NP tissue and co-cultured with 1 × 10(5) ASCs. To determine whether ASCs affect infiltrating T lymphocyte and cytokine expression in eosinophilic NP, T lymphocyte subsets and cytokine expression were analyzed before and after ASC treatment.

RESULTS

ASC treatment significantly decreased the proportions of CD4(+) and CD8(+) T cells. After ASC treatment, Th2 cytokine (interleukin [IL]-4 and IL-5) levels decreased significantly. In contrast, levels of Th1 (interferon-γ and IL-2) and regulatory cytokines (transforming growth factor-β and IL-10) increased significantly after ASC treatment.

CONCLUSIONS

ASCs have immunomodulatory effects in the eosinophilic inflammation of NPs, characterized by down-regulation of activated T lymphocytes and a Th2 immune response. These effects would be expected, over time, to significantly contribute to the control of eosinophilic inflammation and, possibly, growth of eosinophilic NPs.

Epidemiology and differential diagnosis of nasal polyps

BACKGROUND

Chronic rhinosinusitis (CRS) is one of the most common chronic medical conditions, with a significant impact on patient quality of life. CRS is broadly classified into two groups: CRS with nasal polyposis (CRSwNP) and CRS without NP (CRSsNP). Clinically, the major subtypes of CRSwNP may be divided into eosinophilic chronic rhinosinusitis (e.g., allergic fungal rhinosinusitis and aspirin-exacerbated respiratory disease [AERD]) and nasal polyps associated with neutrophilic inflammation (e.g., cystic fibrosis [CF]). CF is characterized by mutation of the gene encoding the CF transmembrane conductance regulator. Functional endoscopic sinus surgery is usually required for most NP patients with increased frequency in patients with AERD. This study provides a review of the epidemiology and major classification of CRSwNP.

METHODS

A review was performed of the literature regarding different subtypes of CRSwNP.

RESULTS

Many definitions of CRSwNP exist and estimates of prevalence vary.

CONCLUSION

CRSwNP is a clinical syndrome with a heterogeneous inflammatory profile. Of the subtypes associated with eosinophilic inflammation, AERD remains the most recalcitrant to medical and surgical therapeutic interventions.

Increased activation and differentiated localization of native and phosphorylated STAT3 in nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial disease; the underlying mechanisms of cell signalling are not fully understood. STAT3 (signal transducer and activator of transcription 3) is a phosphokinase and a key signalling molecule implicated in cell cycle regulation. We studied the distribution and expression of STAT3 to examine the role of STAT3 in the pathogenesis of CRSwNP.

METHODS

We investigated tissue samples of the nasal polyps and inferior turbinate of patients with CRSwNP as well as samples of the inferior turbinate of subjects without chronic sinusitis. The expression levels of STAT3 and its activated form pSTAT3 were analysed using Western blotting, protein array, DNA microarray and immunohistochemistry.

RESULTS

No significant differences were found in STAT3-mRNA levels between the samples of nasal polyps and inferior turbinates of the same patient. However, the amount of pSTAT3 was increased in the polyp tissue compared to the inferior turbinates from both CRSwNP patients and control subjects (p < 0.01), indicating an activation of STAT3 in polyps. We identified a varying distribution pattern of pSTAT3; pSTAT3 was primarily found in superficial epithelial cells but not in the basal layer of the epithelium of the turbinate, whereas pSTAT3 was located in all layers of the epithelium of the polyp and mostly noted in the basal layer.

CONCLUSIONS

Our results of the activation and varying localisation of STAT3 and its phosphorylated form in nasal polyps suggest that pSTAT3 plays a crucial role in the proliferative development of nasal polyps.

Staphylococcal enterotoxin B induced expression of IL-17A in nasal epithelial cells and its association with pathogenesis of nasal polyposis

Interleukin (IL)-17A is a highly inflammatory cytokine and is known to be produced by Th17 cells. The importance of IL-17A expression in nasal epithelial cells is not well understood. The goal of this study is to explore the expression of IL-17A in nasal epithelial cells in vivo and in vitro. IL-17A and staphylococcal enterotoxin B (SEB) were detected by immunofluorescence (IF) in nasal epithelial cells of control mucosa (n = 10) and nasal polyps (n = 20). Expression of IL-17A, RORC, IL-6, and TGF-β1 was also measured by RT-PCR in the tissue of control nasal mucosa (n = 10) and nasal polyps (n = 20). IL-17A expression was evaluated in the human nasal epithelial cells after SEB stimulation. Finally, IL-17A expression was demonstrated by immunohistochemistry and IF following intranasal SEB instillation in mice. Expression of IL-17A in nasal epithelial cells was higher in nasal polyps compared to control mucosa. There was a significant correlation between IL-17A and SEB detection in nasal polyps using IF. SEB increased IL-17A expression in human nasal epithelial cells, and in epithelial cells of SEB instilled mice. In conclusion, SEB exposure of nasal epithelial cells induces the enhanced expression of IL-17A. SEB may be involved in pathogenesis of nasal polyps by enhancing IL-17A expression in epithelial cells in nasal polyps.

Allergic rhinitis, chronic rhinosinusitis and asthma: unravelling a complex relationship

PURPOSE OF REVIEW

Allergic rhinitis, chronic rhinosinusitis (CRS) and asthma have a high worldwide prevalence and confer a significant socioeconomic burden. This article reviews the recent advances in allergic rhinitis, CRS and asthma with view to understanding the upper and lower airway as one system.

RECENT FINDINGS

Allergic rhinitis, CRS and asthma demonstrate strong epidemiological coassociation, and early life risk factors for upper airway disease are now apparent. The absence of demonstrable peripheral IgE does not strictly classify airway disease as nonallergic. Excess mucosal inflammation with immune dysregulation is a common feature to all. An important role for innate immunity is now apparent and offers prospects of novel therapeutic approaches in the future. A role for bacterial superantigens is also emerging in all three diseases. Genetic studies highlight common associations between allergic rhinitis, CRS and asthma.

SUMMARY

Whether such overlapping pathological findings reflect a manifestation of the same disease but in relation to the different airway locations in individuals with genetic predisposition remains unknown, although likely. This continues under investigation and debate. The current research priorities are to understand what key events predispose to both upper and lower airway disease together and the critical immunological factors that establish and sustain airway inflammation.

Nasal polyposis: an inflammatory condition requiring effective anti-inflammatory treatment

PURPOSE OF REVIEW

Recent literature in chronic rhinosinusitis with nasal polyps (CRSwNP) has focussed on inflammatory mechanisms underlying the disease. Endotyping the histopathological features of the disease, rather than simple clinical phenotypes, reflects a change in our understanding of the disease and approach to management. This is paralleled by renewed evidence for the need for wide postsurgical access and topical anti-inflammatory therapy.

RECENT FINDINGS

Recent research into patterns of dysfunction in innate immunity suggests a crucial role of respiratory epithelium in mediating the inflammatory response. Elevated interleukins, IL-25 and IL-33, from sinus mucosa in CRSwNP and their interaction via innate lymphoid cells may represent the link between the host-environment interface and T-helper 2 dominated inflammation that characterizes CRSwNP. While thorough immunological profiling of CRSwNP is not routinely available, classification of CRS as eosinophilic (ECRS) or noneosinophilic is practical and correlates with disease severity and prognosis. The practice and utility of endoscopic sinus surgery to create a single neosinus for topical corticosteroid delivery is a logical conclusion founded on the inflammatory basis of CRSwNP/ECRS.

SUMMARY

There is mounting evidence for CRSwNP as a predominantly inflammatory disease. Even simple histopathological classification on the basis of degrees of tissue eosinophilia reflects the underlying pathogenic mechanisms with diagnostic and prognostic implications. Optimal treatment involves topical anti-inflammatory therapy delivered locally via a wide, postsurgical corridor.

Interleukin-17A expression in patients with chronic rhinosinusitis and its relationship with clinical features

OBJECTIVE

To investigate the expression of interleukin (IL) 17A in Chinese patients with chronic rhinosinusitis (CRS) and analyse its correlation with clinical parameters.

METHODS

Patients undergoing functional endoscopic sinus surgery and matched controls were included in this retrospective study. Clinical assessments (using a visual analogue scale of symptom severity, Johansson endoscopic score and Lund-Mackay computed tomography score) were performed preoperatively. Mucosal specimens were analysed for inflammatory infiltration and IL-17A expression, using immunohistochemistry.

RESULTS

In total, 40 patients undergoing functional endoscopic sinus surgery and 16 controls were included in the study. IL-17A levels were significantly higher in tissues from patients with CRS (with or without nasal polyps) than in control tissues. In CRS, IL-17A expression tended to be higher in tissues with infiltrating neutrophils than in those with infiltrating eosinophils, but this difference was not significant. IL-17A expression in CRS was positively correlated with symptom severity, endoscopic findings and radiological appearance.

CONCLUSIONS

Expression of IL-17A was higher in Chinese patients with CRS than in controls, and was associated with infiltrating inflammatory cells, symptom severity, endoscopic findings and radiological appearance. These findings suggest that IL-17A may play a role in CRS pathogenesis and remodelling of nasal polyps.