Lymphocyte Subpopulations and Cytokines in Nasal Polyps: Is there a Local Immune System in the Nasal Polyp?

Chronic Rhinosinusitis, S. aureus Biofilm and Secreted Products, Inflammatory Responses, and Disease Severity

Chronic rhinosinusitis (CRS) is a persistent inflammation of the nasal cavity and paranasal sinuses associated with tissue remodelling, dysfunction of the sinuses' natural defence mechanisms, and induction of different inflammatory clusters. The etiopathogenesis of CRS remains elusive, and both environmental factors, such as bacterial biofilms and the host's general condition, are thought to play a role. Bacterial biofilms have significant clinical relevance due to their potential to cause resistance to antimicrobial therapy and host defenses. Despite substantial medical advances, some CRS patients suffer from recalcitrant disease that is unresponsive to medical and surgical treatments. Those patients often have nasal polyps with tissue eosinophilia, S. aureus-dominant mucosal biofilm, comorbid asthma, and a severely compromised quality of life. This review aims to summarise the contemporary knowledge of inflammatory cells/pathways in CRS, the role of bacterial biofilm, and their impact on the severity of the disease. Here, an emphasis is placed on S. aureus biofilm and its secreted products. A better understanding of these factors might offer important diagnostic and therapeutic perceptions for recalcitrant disease.

Cytokine Signature and Involvement in Chronic Rhinosinusitis with Nasal Polyps

Cytokines are well known to play a central role in chronic rhinosinusitis with nasal polyps (CRSwNP), particularly in maintenance of the inflammatory response and the recruitment of eosinophils. The pathophysiological concepts concerning the involvement of inflammatory cytokines in CRSwNP have gradually evolved. Although the Th2 cytokines environment associated with an eosinophilic infiltration has retained a central role in the genesis of polyps, the role of other cytokine subpopulations has also and more recently been detailed, leading to a specific and complex signature in CRSwNP. The purpose of this review is to summarize the current state of knowledge about the cytokine signature in CRSwNP, the role of cytokines in the pathogenesis of this disease and in the intercellular dialog between epithelial cells, fibroblasts and inflammatory cells. Knowledge of this precise cytokine signature in CRSwNP is fundamental in the perspective of potential targeting biotherapies.

Involvement of inflammatory cells in chronic rhinosinusitis with nasal polyps

Inflammation plays an important role in the pathogenesis of nasal polyps. Understanding the biomolecular action mechanisms of inflammatory elements can contribute to improving the prognosis of these lesions. The study analyzed the distribution and immunohistochemically quantified eosinophils [eosinophil major basic protein (BMK-13)], lymphocytes [cluster of differentiation (CD) 4, CD8, CD20] and plasmocytes (CD138) in both the epithelial and stromal compartment in relation to composite scores, which included specific histopathological parameters for 50 sinonasal polyps. Inflammatory elements predominated at stromal level, the high histological composite scores being frequently associated with increased expression of inflammatory elements. Also, the numerical distribution of inflammatory elements indicated positive linear relations within the groups BMK-13/CD8 and CD4/CD20/CD138, and a negative linear relation between the two groups. This aspect can support the existence of alternative or sequential pathogenic mechanisms involved in the pathogenesis of sinonasal polyps, and the results obtained can be used for a better stratification of patients in order to optimize the therapy.

BMP-7, MMP-9, and TGF-β tissue remodeling proteins and their correlations with interleukins 6 and 10 in chronic rhinosinusitis

INTRODUCTION

Chronic rhinosinusitis without nasal polyposis (CRSsNP) and Chronic rhinosinusitis with nasal polyposis (CRSwNP) present distinct tissue remodeling processes. The proteins involved in the process of tissue remodeling have their production and activity related to the inflammatory environment they are. This study aimed to evaluate the protein expression of BMP-7, MMP-9, TGF-β in chronic sinusitis with and without nasal polyposis and their relations with IL-6 and IL-10.

METHODS

Cross-sectional observational study with 86 participants was divided into three groups: patients with CRSwNP (n = 34), patients with CRSsNP (n = 26), and a control group (CG) without inflammatory disease of the nasal mucosa (n = 26). The primary outcomes were the concentrations of BMP-7, MMP-9, TGF-β, IL-6, and IL-10. Secondary outcomes were the correlations of these markers.

RESULTS

The TGF-β dosage was elevated in the CRSsNP group and reduced in the CSwNP group. The dosage of IL-6 was higher in the CSwNP group, and the IL-10 dosage lower in the groups with sinusitis, and IL-10 was positively correlated with BMP-7 in all groups. There was a negative correlation between IL-6 and IL-10 in all groups observed. The correlation between MMP-9 and interleukins was lost in the CRSsNP group. There was a positive correlation between TGF-β and IL-6 in the CG, and negative in the CRSsNP group.

CONCLUSION

An inflammation shown in rhinosinusitis with an increase in IL-6 and decrease in IL-10 when compared with the control group; only TGF-β was altered in the tissue remodeling process when compared with BMP-7 and MMP-9 in rhinosinusitis. There is a loss of correlation between tissue remodeling proteins and interleukins studied in CRSsNP.

Exosomes Represent an Immune Suppressive T Cell Checkpoint in Human Chronic Inflammatory Microenvironments

Background: T cells present in chronic inflammatory tissues such as nasal polyps (from chronic rhinosinusitis patients) have been demonstrated to be hypo-responsive to activation via the TCR, similar to tumor-specific T cells in multiple different human tumor microenvironments. While immunosuppressive exosomes have been known to contribute to the failure of the tumor-associated T cells to respond optimally to activation stimuli, it is not known whether they play a similar role in chronic inflammatory microenvironments. In the current study, we investigate whether exosomes derived from chronic inflammatory microenvironments contribute to the immune suppression of T cells. Methods: Exosomes were isolated by ultracentrifugation and characterized by size and composition using nanoparticle tracking analysis, scanning electron microscopy, antibody arrays and flow exometry. Immunosuppressive ability of the exosomes was measured by quantifying its effect on activation of T cells, using nuclear translocation of NFκB as an activation endpoint. Results: Exosomes were isolated and characterized from two different types of chronic inflammatory tissues - nasal polyps from chronic rhinosinusitis patients and synovial fluid from rheumatoid arthritis patients. These exosomes arrest the activation of T cells stimulated via the TCR. This immune suppression, like that which is seen in tumor microenvironments, is dependent in part upon a lipid, ganglioside GD3, which is expressed on the exosomal surface. Conclusion: Immunosuppressive exosomes present in non-malignant chronic inflammatory tissues represent a new T cell checkpoint, and potentially represent a novel therapeutic target to enhance the response to current therapies and prevent disease recurrences.

Evaluation of the frequency of invariant natural killer T (iNKT) cells in nasal polyps

Nasal polyps (NP) are associated with inflamed mucosa of unknown etiology. The role of T cells in nasal polyposis is unclear. Invariant natural killer T cells (iNKT) can promote Th2 responses and have been implicated in some types of asthma. As there are shared inflammatory pathways involved in asthma and NPs, we evaluated the frequency of iNKT in 17 patients with NPs, but without asthma. A median of 6% polyp cells were T lymphocytes, of which iNKT were 0 to 2.38% (mean 0.674%). In the matched group (n = 10), iNKT in NPs was significantly higher than PBMCs (1.057% vs 0.155%, P < 0.05). Relative expression of Vα24 to TCR-beta genes in polyps (n = 14) was higher than blood in matched samples (n = 4). The presence of greater proportions of iNKT in NPs than in blood suggests that iNKT may play a role in the pathogenesis of nasal polyposis.

Frequency of CD4+ and CD8+ T cells in Iranian chronic rhinosinusitis patients

Background

Chronic Rhinosinusitis (CRS) is a persistent inflammatory disease affecting paranasal sinuses. CRS is categorized into two distinct subgroups defined as CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). Although several immune cells are involved in the CRS pathogenesis, the role of T cells is not fully understood. The objective of the present study was to evaluate the frequency of CD4⁺ and CD8⁺ T cells and macrophages in the sinonasal mucosa of CRS patients, as well as to investigate the specific transcription factors for Th1, Th2, Th17, and Treg cells.

Methods

In this study, 15 healthy controls, 12 CRSsNP, and 23 CRSwNP patients participated. CD4⁺, CD8⁺, and CD68⁺ cells were investigated in the sinonasal tissues using immunohistochemistry. The expression of transcription factors related to Th subsets (T-bet, GATA3, Ror-γt, and FoxP3) was evaluated using real-time PCR. Furthermore, CRSwNP patients were defined as eosinophilic when eosinophils consisted of more than 10% of total inflammatory cells. The Kruskal–Wallis, Mann–Whitney, and Spearman tests were used in statistical analyses.

Results

The median (range) age of the studied groups was: 32 (14–67) for CRSwNP, 28 (10–43) for CRSsNP, and 27 (17–44) for controls. The number of eosinophils in CRSwNP patients was higher than two other groups, whereas neutrophils were elevated in both CRSwNP and CRSsNP groups in comparison to controls. The frequency of CD4⁺ and CD8⁺ T cells, macrophages, and total inflammatory cells were significantly increased in CRSwNP and CRSsNP patients compared with controls. The mRNA expression of GATA3 was increased in CRSwNP patients while mRNA expression of Ror-γt was elevated in CRSsNP patients. No significant difference was observed in T-bet mRNA expression among three groups. Both CRSwNP and CRSsNP patients showed decreased FoxP3 mRNA expression in comparison to controls.

Conclusion

The frequency of CD4⁺ and CD8⁺ T cells was elevated in CRS patients. In addition, we demonstrated Th2 dominance in CRSwNP patients and Th17 dominance in CRSsNP patients, implicating different mechanisms may underlie the disease. Better CRS classification and targeted therapeutic strategies may be achievable by determining the pattern of infiltrating inflammatory cells. Therefore, further experimental investigations on T cells are needed.

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.

Peripheral Blood T-Helper Cells and Eosinophil Populations in Patients with Atopic and Nonatopic Chronic Rhinosinusitis

Background

Analysis of recent research indicated that T-helper cells may play an important role in the pathogenesis of chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP).

Objective

The purpose of this study was to investigate the peripheral blood Th1 and Th2 cells and eosinophil population in patients with CRS.

Methods

Peripheral blood samples were obtained from nine nonatopic controls, 37 patients with CRSsNP, and 66 patients with CRSwNP. The samples were then analyzed by flow cytometry analysis (Th1 cell [CD4+, interleukin 4−, interferon γ+]; and Th2 cell [CD4+, interleukin 4+, interferon γ−]). The patients were stratified into four groups based on their allergic status by using skin-prick test results and immunoglobulin E level measurements as the following: (1) nonatopic CRSsNP, (2) nonatopic CRSwNP, (3) atopic CRSsNP, and (4) atopic CRSwNP. Eosinophil counts were also compared. The severity of nasal diseases in these patients was assessed via the Lund-Mackay score.

Results

No significant differences in peripheral blood Th1 and Th2 cells were found among all the atopic, nonatopic CRS groups, and the nonatopic control groups. Peripheral blood eosinophil levels in atopic CRSwNP were significantly elevated compared with the nonatopic controls (p < 0.05), but no significant difference was found among all atopic and nonatopic CRS groups.

Conclusion

Analysis of our data demonstrated that a proportion of systemic Th1- and Th2-skewed lymphocytes in all CRS groups were similar to that in healthy subjects, irrespective of atopic status. The patients with CRSwNP and with atopy but not the patients with CRSsNP and with atopy demonstrated systemic eosinophilic inflammation. Further studies are needed to investigate underlying pathophysiologic mechanism or endotypes.

Improvement in allergic and nonallergic rhinitis: A secondary benefit of adenoidectomy in children

Chronic rhinitis (CR) is a common disorder in children. Allergic rhinitis (AR) is a risk factor for CR, and children with AR tend to suffer more from hypertrophic adenoids than do patients with nonallergic rhinitis (NAR). Few studies have addressed the issue of alleviating symptoms of pediatric CR or AR following adenoidectomy alone. We conducted a retrospective chart review to determine whether CR in children improves after adenoidectomy and whether children with AR will benefit more than those with NAR. Charts of 47 children who had undergone adenoidectomy for nasal obstruction and chronic middle ear effusion were reviewed. AR and NAR subgroups were classified based on symptoms, signs, blood IgE, and nasal smear (allergic criteria). Hypertrophic adenoids were graded using the adenoid-to-nasopharyngeal ratio (ANr >0.8). A questionnaire was used to assess the change in chronic rhinitis postoperatively. Improvement in CR was reported in 37 of 47 (79%) children. Patients with AR improved to a higher extent than those with NAR (12 of 14 [86%] vs. 25 of 33 [76%], respectively), but the difference was not statistically significant. A total of 41 lateral postoperative nasopharyngeal x-rays were obtained. The x-rays revealed that 20 of 26 (77%) of patients with ANr >0.8 had complete and 4 of 26 (15%) had partial resolution of symptoms of CR for a total resolution rate of 92%, compared to only a 53% resolution in the ANr <0.8 subgroup (6 of 15 and 2 of 15 patients, respectively [p <0.05]). The correlation between adenoid size and resolution of CR was not related to any of the AR/NAR subgroups. We conclude that symptoms of CR may improve after adenoidectomy in children who are experiencing nasal obstruction and chronic otitis media with effusion. Clinical improvement did not differ between AR and NAR patients, and was more prominent in children with hypertrophic adenoids (ANr >0.8).

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.

Human Nasal Polyp Microenvironment Maintained in Viable and Functional States as Xenografts in SCID Mice

Objectives:

We undertook to maintain human nasal polyp tissue in a viable and functional state in SCID (severe combined immunodeficiency) mice.

Methods:

Small, nondisrupted pieces of human nasal polyp tissues were subcutaneously implanted into SCID mice depleted of natural killer cells. The resulting xenografts were examined histologically, and the sera were evaluated for the presence of human protein.

Results:

The original histologic architecture of the polyp was maintained in the xenografts. The tissues, including pseudostratified columnar epithelial–lined polyps and subepithelial stroma, remained viable, and goblet cells continued to produce mucin for up to 26 weeks after engraftment. Human inflammatory leukocytes, including CD3+ T cells, CD20+ B cells, CD138+ plasma cells, and CD68+ monocytes and/or macrophages, were present. Identification of human immunoglobulin and human interferon-γ in the sera of xenograft-bearing mice indicated that the B cells or plasma cells and T cells within the xenografts remained functional for 2 weeks after engraftment.

Conclusions:

The ability to engraft and maintain nasal polyps provides an in vivo human/mouse chimeric model with which to investigate the role of inflammatory leukocytes and stromal cells in the maintenance and progression of polyposis and to determine how exogenous cytokines may alter the interaction of inflammatory cells, stromal cells, and epithelial cells in the polyp.

CD8(+) T cells with distinct cytokine-producing features and low cytotoxic activity in eosinophilic and non-eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

CD8(+) T cells are important effectors of cell-mediated immunity; however, their contribution to the pathogenesis of CRS is unclear.

OBJECTIVE

This study aimed to characterize the cytokine-producing features and cytotoxic activity of CD8(+) T cells, and their correlation with inflammation patterns in CRS with nasal polyps.

METHODS

The expression of IFN-γ, IL-4, IL-5, IL-17A, forkhead box P3 (FOXP3), perforin, and granzyme B in CD8(+) T cells was studied by means of flow cytometry, immunohistochemistry, and immunofluorescence. The expression of CD8(+) T-cell subset relevant chemokines and chemokine receptors was detected by means of real-time RT-PCR or ELISA. The cytotoxic activity of sorted CD8(+) T cells was defined by anti-CD3-redirected killing assay.

RESULTS

Compared with controls, elevated percentages of total CD8(+) T cells and cytotoxic T lymphocyte (Tc) 1 (IFN-γ(+) ), Tc2 (IL-4(+) ), and Tc17 (IL-17A(+) ) cell subset, and decreased percentages of FOXP3(+) CD8(+) regulatory T cells, were found in both eosinophilic and non-eosinophilic polyps with a Tc2-skewed and Tc1/Tc17-dominated response in eosinophilic and non-eosinophilic polyps, respectively. Nasal CD8(+) T cells were found to produce similar or even higher levels of IFN-γ and IL-4 compared with CD4(+) T cells. Tc1 and Tc17, and Tc2 (IL-4(+) and IL-5(+) ) cell subset percentages positively correlated with neutrophil and eosinophil counts in sinonasal mucosa, respectively. Strikingly, the expression of perforin and granzyme B and cytotoxic activity were significantly reduced in nasal CD8(+) T cells compared with their counterparts in peripheral blood. The expression of CXCL16, CCL17, and CCL20 positively correlated with Tc1, Tc2, and Tc17 cell subset number in sinonasal mucosa, respectively.

CONCLUSION AND CLINICAL RELEVANCE

CD8(+) T cells have low cytotoxic activity; nevertheless, they are a significant and previously underappreciated source of inflammatory cytokine production in polyps. Different Tc cell subset domination may contribute to distinctly biased granulocyte inflammation in eosinophilic and non-eosinophilic polyps.

Comprehensive review on endonasal endoscopic sinus surgery

Endonasal endoscopic sinus surgery is the standard procedure for surgery of most paranasal sinus diseases. Appropriate frame conditions provided, the respective procedures are safe and successful. These prerequisites encompass appropriate technical equipment, anatomical oriented surgical technique, proper patient selection, and individually adapted extent of surgery. The range of endonasal sinus operations has dramatically increased during the last 20 years and reaches from partial uncinectomy to pansinus surgery with extended surgery of the frontal (Draf type III), maxillary (grade 3-4, medial maxillectomy, prelacrimal approach) and sphenoid sinus. In addition there are operations outside and beyond the paranasal sinuses. The development of surgical technique is still constantly evolving. This article gives a comprehensive review on the most recent state of the art in endoscopic sinus surgery according to the literature with the following aspects: principles and fundamentals, surgical techniques, indications, outcome, postoperative care, nasal packing and stents, technical equipment.

T cells in chronic rhinosinusitis with nasal polyposis

PURPOSE OF REVIEW

The cause of nasal polyp disease remains controversial. Examination of the T lymphocytes involved in nasal polyp inflammation may lead to an improved understanding of the cause, prognosis, and treatment of chronic rhinosinusitis with nasal polyposis.

RECENT FINDINGS

T lymphocytes are important directors of the inflammatory process in allergic rhinitis and asthma, but the role of T lymphocytes in chronic rhinosinusitis with nasal polyposis has not been thoroughly investigated. The T lymphocyte infiltrate in nasal polyps may vary based upon genetic factors, polyp histology, or the presence of asthma/atopy. Staphylococcal enterotoxins, which are known to activate T cells, stimulate proinflammatory cytokine secretion by nasal polyp cells, whereas regulatory cytokines are not similarly up regulated by enterotoxin exposure. The inflammation in nasal polyps may be related to deficient function of regulatory T cells. New data on staphylococcal enterotoxins and regulatory T cells point to possible roles for T cells in chronic rhinosinusitis with nasal polyposis.

SUMMARY

Further study of the T cell compartment in nasal polyps may lead to a better understanding of the intrinsic and extrinsic factors responsible for nasal polyp inflammation.

Deprived TLR9 expression in apparently healthy nasal mucosa might trigger polyp-growth in chronic rhinosinusitis patients

Background

The origin of nasal polyps in chronic rhinosinusitis is unknown, but the role of viral infections in polyp growth is clinically well established. Toll-like receptors (TLRs) have recently emerged as key players in our local airway defense against microbes. Among these, TLR9 has gained special interest in viral diseases. Many studies on chronic rhinosinusitis with nasal polyps (CRSwNP) compare polyp tissue with nasal mucosa from polyp-free individuals. Knowledge about changes in the turbinate tissue bordering the polyp tissue is limited.

Objectives

To analyse the role of TLR9 mediated microbial defense in tissue bordering the polyp.

Methods

Nasal polyps and turbinate tissue from 11 patients with CRSwNP and turbinate tissue from 11 healthy controls in total were used. Five biopsies from either group were analysed immediately with flow cytometry regarding receptor expression and 6 biopsies were used for in vitro stimulation with a TLR9 agonist, CpG. Cytokine release was analysed using Luminex. Eight patients with CRSwNP in total were intranasally challenged with CpG/placebo 24 hours before surgery and the biopsies were collected and analysed as above.

Results

TLR9 expression was detected on turbinate epithelial cells from healthy controls and polyp epithelial cells from patients, whereas TLR9 was absent in turbinate epithelial cells from patients. CpG stimulation increased the percentage cells expressing TLR9 and decreased percentage cells expressing VEGFR2 in turbinate tissue from patients. After CpG stimulation the elevated levels of IL-6, G-CSF and MIP-1β in the turbinate tissue from patients were reduced towards the levels demonstrated in healthy controls.

Conclusion

Defects in the TLR9 mediated microbial defense in the mucosa adjacent to the anatomic origin of the polyp might explain virus induced polyp growth. CpG stimulation decreased VEGFR2, suggesting a role for CpG in polyp formation. The focus on turbinate tissue in patients with CRSwNP opens new perspectives in CRSwNP-research.

Cytokine expression before and after aspirin desensitization therapy in aspirin-exacerbated respiratory disease

Aspirin exacerbated respiratory disease (AERD) is induced by acetylsalicylic acid (ASA) and/or nonsteroidal antiinflammatory drugs (NSAIDs). Effects of desensitization on many mediators have been examined previously, but few studies addressed the influence of desensitization on T lymphocytes and T lymphocyte-derived cytokines. This study was performed to examine peripheral blood lymphocyte (PBL) cytokine expression in aspirin-sensitive patients who have asthma before and after aspirin desensitization. In this study, the release of interleukin-2 (IL-2), interleukin-4 (IL-4), and interferon-gamma (IFN-γ) by CD4+ T lymphocytes prior to aspirin desensitization were also measured at intracellular levels, and expression of these cytokines after 1 month aspirin desensitization was evaluated. Twelve patients with AERD were included in the study. Two different control groups were formed, one consisted of 15 healthy people and second 12 aspirin tolerant asthmatic (ATA) patients using aspirin. A blood sample was collected prior to desensitization, and the tests were repeated by taking a second blood sample 1 month after the 4-day desensitization treatment. The proportion of lymphocytes secreting IFN-γ in the study group was 15.61 ± 4.40 % before desensitization and 15.08 ± 5.89 % after desensitization. The rate of IFN-γ secreting CD4+ T lymphocytes was 20.51 ± 4.41 % in the normal control group and 16.07 ± 5.7 % in the ATA group (p = 0.021). The ratio of CD4+ T lymphocyte secreting IFN-γ was reduced in patients with AERD before desensitization compared to normal control group (p = 0.040). The levels of IL-2, IL-4, and the subsets of lymphocyte were not different before and after desensitization compared to control groups.

Interleukin-17A expression in patients presenting with nasal polyposis

Sinonasal polyposis (SNP) is a chronic inflammatory pathology of the nasal/paranasal cavities which affects from 1%-4% of the population. Although polyps seem to be a manifestation of chronic inflammation of nasal/paranasal sinus mucosa in both allergic and non-allergic subjects, the pathogenesis of nasal polyposis remains unknown. Interleukin-17A (IL-17A) is a key inflammatory cytokine in many disorders. Little attention has been paid to the role of IL-17A in chronic inflammatory disorders.

Objective

To investigate the expression of IL-17A in the SNP and verify if this expression is a marker of good or bad prognosis.

Method

Prospective study with 25 patients presenting with SNP were subjected to the immunohistochemistry technique. After a skin prick test, all patients were divided into atopic and nonatopic groups, and asthmatic or non-asthmatic.

Results

The IL-17A expression was observed in both atopic and nonatopic patients. The numbers of IL-17A positive cells were greater in nasal polyps of atopic patients than nonatopic (p = 0.0128).

Conclusion

These results indicate that IL-17A may play an important role in the pathology of SNP. Considering the inflammatory properties of IL-17A, this study suggests that it could increase susceptibility to atopy and asthma.

Systemic prednisone administration selectively alters granulocyte subsets in nasal polyps from aspirin-exacerbated respiratory disease and chronic rhinosinusitis patients

BACKGROUND

Nasal polyps (NPs) are hallmark inflammatory lesions of sinusitis. Despite the spectrum of NP conditions, cellular differences between NPs from patients with chronic rhinosinusitis with NPs (CRSwNP) and aspirin-exacerbated respiratory disease (AERD) are poorly understood. NPs are associated with abundant eosinophils; the contributions of neutrophil and basophil granulocytes are less defined. We therefore sought to assess granulocyte subpopulations, and differential effects following prednisone pretreatment, within NPs of CRSwNP and AERD patients.

METHODS

NPs, adjacent ethmoid sinus tissue, and peripheral blood mononuclear cells (PBMCs) were obtained from patients undergoing endoscopic sinus surgery. Samples from 5 cohorts: CRSwNP ± prednisone (n = 6 each), AERD ± prednisone (n = 6 each), and controls (n = 9), were analyzed by high-dimensional flow cytometry to gate granulocyte populations. Specimens were also assessed using immunohistochemistry (IHC) staining.

RESULTS

Systemic prednisone administration was associated with a lower frequency of eosinophils (p < 0.0001, n = 6) in NPs in both CRSwNP and AERD patients, whereas a decrease in neutrophils (p = 0.0070, n = 6) in NPs was only observed in CRSwNP patients after prednisone treatment. In contrast, steroids do not alter basophil proportions (p = 0.48, n = 6) within NPs from either group. No significant shift in granulocyte subsets after steroid treatment was identified in the adjacent ethmoid mucosa or PBMCs from the same patients. Immunohistochemistry (IHC) staining supported these findings.

CONCLUSION

Granulocyte subpopulations are focally affected within NPs by systemic steroid exposure, without notable granulocyte alterations in the surrounding regional tissues. These data provide direct insights into the cellular effects of routine prednisone exposure in CRS patients, and highlight a unique microenvironment present within NP lesions.

Cytokine correlation between sinus tissue and nasal secretions among chronic rhinosinusitis and controls

OBJECTIVES/HYPOTHESIS

Compare cytokine levels in sinus tissue to sinus secretions from controls and chronic rhinosinusitis patients.

STUDY DESIGN

In vitro.

METHODS

Polyurethane foam sponges were placed into middle meati of patients with chronic rhinosinusitis without nasal polyps (CRSsNP), with polyps (CRSwNP), and controls. Sinus biopsies were then taken from the same location. Protein levels of tumor necrosis factor-alpha (TNF-α), interferon-γ (IFN-γ), and interleukins (IL) 2, 4, 6, 8, 10, and 17A were measured via cytometric bead assay for each sample. Protein values from sinus tissue and secretions were compared with Pearson's correlation between samples as well as one-way ANOVA with posthoc t test between groups.

RESULTS

Samples from 43 patients in total were examined. Mucus was measured from 10 controls, 11 CRSsNP and 10 CRSwNP, and sinus tissue was measured from 10 controls, 15 CRSsNP and 10 CRSwNP. IL-8 and IFN-γ levels were outside of the detectable range of the assay. Levels of secreted IL-2, 4, 6, 10, and 17A correlated with tissue levels (P < 0.05 for all, r > 0.49) while TNF-α did not (P = 0.71). CRSsNP had elevated mucus levels of IL-2, 4, 6, 10, and 17A compared to controls. CRSwNP had elevated mucus levels of IL-4, 6, 10, 17A, and TNF-α compared to controls.

CONCLUSIONS

Cytokine levels in sinus secretions correlate with levels in sinus tissue and are elevated in CRS versus control based on Th1/Th2 skewing.

Increased expression of chemokine receptors CCR1 and CCR3 in nasal polyps: molecular basis for recruitment of the granulocyte infiltrate

Inflammatory processes play an important role in the development of nasal polyps (NP), but the etiology and, to a high degree also, the pathogenesis of NP are not fully understood. The role of several cytokines and chemokines such as eotaxins, IL-4, IL-5, IL-6, IL-8, and RANTES has been reported in NP. Herewith, we investigated the expression and pattern of distribution of chemokine receptors CCR1 and CCR3 in nasal polyps. Immunohistochemical detection was carried out in frozen sections of biopsies from 22 NP and 18 nasal mucosa specimens in both the epithelial and stromal compartments. Fluorescence microscopy and computerized image analysis revealed a statistically significant increased number of CCR1 (45.2 ± 2.8 vs. 15.1 ± 1.9, p < 0.001)-positive as well as CCR3 (16.4 ± 1.4 vs. 9.7 ± 1.1, p < 0.001)-positive cells in the stroma of NP compared to nasal mucosa. In comparison to healthy nasal mucosa, increased positivity of CCR3 was detected in the epithelial compartment of NP. Our data suggest that increased expression of CCR1 and CCR3 chemokine receptors may, in accord with various chemokines, contribute to the pathogenesis of nasal polyposis by facilitating increased migration and prolonged accumulation of inflammatory cells, e.g., eosinophils, in the inflammatory infiltrate of NP.

Memory T cells in the chronic inflammatory microenvironment of nasal polyposis are hyporesponsive to signaling through the T cell receptor

A majority of T cells from chronic inflammatory tissues derived from patients with nasal polyposis were found to express an effector memory phenotype. We report here that these memory T cells failed to activate NF-κB in response to TCR stimulation but responded normally when the proximal TCR signaling molecules were bypassed with PMA and ionomycin. The dysfunction of these cells was associated with a decrease in the phosphorylation of several TCR proximal signaling molecules including ZAP70, Lck and SLP-76. In addition to the disruption in the TCR signaling pathway, the nasal polyp-associated T cells were shown to have a defect in their ability to translocate LAMP-1 to the cell surface. The results presented here establish that the phenotype and anergy of the T cells in the nasal polyp are similar to those which is seen in memory T cells derived from human tumors and other sites of chronic inflammation.

Decreased Expression of FOXP3 in Nasal Polyposis

Purpose

The pathogenesis of nasal polyposis (NP) is unclear. Eosinophils and mast cells are considered to play important roles in this process. In addition, the levels of Th2-type cells are increased, irrespective of the atopic status of the patient with NP. In this context, we and others have shown high levels of thymus and activation-related chemokine/CCL17, macrophage-derived chemokine, eotaxin, and RANTES in patients with NP. Forkhead box P3 (FOXP3) plays a key role in CD4+CD25+ regulatory T-cell function and represents a specific marker for regulatory T cells (Tregs). Decreased expression of FOXP3 has been reported in allergic diseases. The present study was designed to evaluate the presence and potential roles of Tregs, defined by the expression of FOXP3 protein, in NP.

Methods

Using immunohistochemistry, we estimated the numbers of FOXP3+ cells in the epithelium and lamina propria of the NPs of 17 patients with chronic rhinosinusitis with NP and the nasal mucosa of 15 patients with allergic rhinitis (AR). The number of FOXP3+ cells in NPs was compared with that in the nasal mucosa of patients with AR, and the numbers of FOXP3+ cells in atopic and non-atopic NP were also compared.

Results

The number of FOXP3+ cells in the lamina propria of patients with NP was significantly lower than that in the nasal mucosa of the AR patients (2.79 vs. 5.99, P=0.008). There was no statistically significant difference noted for the numbers of FOXP3+ cells between the epithelium of the NP and the nasal mucosa (3.60 vs. 2.39, P=0.180). Furthermore, the numbers of CD4+FOXP3+ cells were lower in NPs than in the allergic nasal mucosa. There was no difference in the number of FOXP3+ cells between the atopic and non-atopic NP patients.

Conclusions

Fewer Tregs (i.e., decreased FOXP3 expression) are found in NPs than in the nasal mucosa of AR patients. As the severity of eosinophilic, Th2-type inflammation and the levels of inflammatory mediators are much higher in NPs than in the nasal mucosa of AR patients, an inverse co-relationship may exist between these parameters and the number of Tregs. The deficiency of Tregs in NP may account for the more pronounced Th2-type inflammation seen in these patients.

T-lymphocyte subpopulations and B7-H1/PD-1 expression in nasal polyposis

T-lymphocyte subpopulations and B7-H1/programmed death-1 (PD-1) positive lymphocytes infiltrating nasal polyps were evaluated in 17 patients with chronic sinusitis with nasal polyposis. Peripheral blood samples were also obtained from the patients and from 11 healthy controls. The CD4(+), CD8(+), CD3(+), CD19(+), B7-H1(+) and PD-1(+) lymphocyte populations were measured using flow cytometry. Lymphocytes from nasal polyps had significantly fewer CD4(+) but significantly more CD8(+) T-cells compared with lymphocytes from the peripheral blood of patients and controls. The percentages of CD19(+)/B7-H1(+) B-cells and of CD3(+)/PD-1(+) T-cells were significantly higher in the nasal polyp samples than in those from peripheral blood of patients and controls. Changes in the T-lymphocyte subpopulations and in the up-regulation of B7-H1 and PD-1 in lymphocytes infiltrating nasal polyps may be involved in the development of the chronic inflammation associated with nasal polyposis.

Evidence for altered activity of the IL-6 pathway in chronic rhinosinusitis with nasal polyps

BACKGROUND

IL-6 activates T(H)17 cells and regulates the response of B lymphocytes and regulatory T cells. The IL-6 receptor and the membrane protein, glycoprotein 130 (gp130), form an active signaling complex that signals through signal transducer and activator of transcription 3 (STAT3) and other signaling molecules. Both the IL-6 receptor (IL-6R) and gp130 can be found in soluble forms that regulate the pathway.

OBJECTIVE

We measured IL-6 signaling components and IL-17 in chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP), CRS without nasal polyps (CRSsNP), and controls to assess the IL-6 pathway in CRS.

METHODS

IL-6, soluble IL-6R, soluble gp130 (sgp130), and IL-17 were measured in sinus tissue extracts and in nasal lavage fluid by either cytokine bead array or ELISA. phosphoSTAT3 (p-STAT3) was determined by Western blot and by immunohistochemistry.

RESULTS

IL-6 protein was significantly (P < .001) increased in CRSwNP compared with CRSsNP and controls. Soluble IL-6R was also increased in nasal polyp compared with control tissue (P < .01). Despite elevated IL-6 and sIL-6R, IL-17A, E, and F were undetectable in the sinus tissue from most of the patients with CRS and controls. p-STAT3 levels were reduced in the polyp tissue, possibly indicating reduced activity of IL-6 in the tissue. sgp130 was elevated in CRSwNP compared with CRSsNP and controls.

CONCLUSION

p-STAT3 levels are decreased in CRSwNP despite increased levels of IL-6 and sIL-6R and are associated with the absence of an IL-17 response. This may be a response to elevated levels of sgp130, a known inhibitor of IL-6 signaling. These results indicate that IL-6 and its signaling pathway may be altered in CRSwNP.

Human nasal polyp microenvironments maintained in a viable and functional state as xenografts in NOD-scid IL2rgamma(null) mice

OBJECTIVES

The objective was to develop a model with which to study the cellular and molecular events associated with nasal polyp progression. To accomplish this, we undertook to develop a system in which nondisrupted human nasal polyp tissue could be successfully implanted into severely immunocompromised mice, in which the histopathology of the original nasal polyp tissue, including inflammatory lymphocytes, epithelial and goblet cell hyperplasia, and subepithelial fibrosis, could be preserved for prolonged periods.

METHODS

Small, non-disrupted pieces of human nasal polyp tissues were subcutaneously implanted into NOD-scid IL2rgamma(null) mice. Xenografts at 8 to 12 weeks after implantation were examined histologically and immunohistochemically to identify human inflammatory leukocytes and to determine whether the characteristic histopathologic characteristics of the nasal polyps were maintained for a prolonged period. The xenografts, spleen, lung, liver, and kidneys were examined histologically and immunohistochemically and were evaluated for changes in volume. The sera of these mice were assayed for human cytokines and immunoglobulin.

RESULTS

Xenografts of human nasal polyp tissues were established after their subcutaneous implantation into NOD-scid IL2rgamma(null) mice. The xenografts were maintained in a viable and functional state for up to 3 months, and retained a histopathologic appearance similar to that of the original tissue, with a noticeable increase in goblet cell hyperplasia and marked mucus accumulation in the submucosal glands compared to the original nasal polyp tissue. Inflammatory lymphocytes present in the polyp microenvironment were predominantly human CD8+ T cells with an effector memory phenotype. Human CD4+ T cells, CD138+ plasma cells, and CD68+ macrophages were also observed in the xenografts. Human immunoglobulin and interferon-gamma were detected in the sera of xenograft-bearing mice. The polyp-associated lymphocytes proliferated and were found to migrate from the xenografts to the spleens of the recipient mice, resulting in a significant splenomegaly. A progressive increase in the volume of the xenografts was observed with little or no evidence of mouse cell infiltration into the human leukocyte antigen-positive human tissue. An average twofold increase in polyp volume was found at 3 months after engraftment.

CONCLUSIONS

The use of innate and adaptive immunodeficient NOD-scid mice homozygous for targeted mutations in the interleukin-2 receptor gamma-chain locus NOD-scid IL2rgamma(null) for establishing xenografts of nondisrupted pieces of human nasal polyp tissues represents a significant improvement over the previously reported xenograft model that used partially immunoincompetent CB17-scid mice as tissue recipients. The absence of the interleukin-2 receptor gamma-chain results in complete elimination of natural killer cell development, as well as severe impairments in T and B cell development. These mice, lacking both innate and adaptive immune responses, significantly improve upon the long-term engraftment of human nasal polyp tissues and provide a model with which to study how nasal polyp-associated lymphocytes and their secreted biologically active products contribute to the histopathology and progression of this chronic inflammatory disease.

Technical advances in rhinologic basic science research

Chronic rhinosinusitis (CRS) is the single most common self-reported chronic health condition in the United States and is estimated to affect 16% of the adult population annually. Despite the prevalence of this disease, there still exists an incomplete understanding of CRS pathophysiology. In this review, the authors highlight technological advances in rhinology: real-time polymerase chain reaction, epithelial cell culture, flow cytometry, genomics/single-nucleotide polymorphism detection, microarrays, and genetic/nongenetic animal models of sinusitis. The purpose of this review is to describe these methodologies and their contributions toward achieving a better understanding of CRS.

Role of nasal allergy in chronic secretory otitis media

Nasal allergy seems to be one of the important causes of chronic secretory otitis media (SOM) in children and adults. Chronic SOM is unequivocally related to disturbed function of the eustachian tube, which facilitates communication of the middle ear with the nasopharynx, nasal cavity, and indirectly with paranasal sinuses. The most serious consequences of chronic SOM are decreased elasticity of the tympanic membrane and hearing impairment. Allergic reactions in the nasal mucosa leading to release of various mediators result in development of three types of nasal response characterized predominantly by nasal obstruction. Eustachian tube functions can be affected directly by the mediators released in the nasal mucosa or indirectly by the nasal obstruction. Nasal challenges with allergens performed by rhinomanometry, combined with tympanometry and eventually audiometry, may be a useful diagnostic supplement for this disorder.

Important research questions in allergy and related diseases: 3-chronic rhinosinusitis and nasal polyposis - a GALEN study

Chronic rhinosinusitis is one of the most common health care challenges, with significant direct medical costs and severe impact on lower airway disease and general health outcomes. The diagnosis of chronic rhinosinusitis (CRS) currently is based on clinical signs, nasal endoscopy and CT scanning, and therapeutic recommendations are focussing on 2 classes of drugs, corticosteroids and antibiotics. A better understanding of the pathogenesis and the factors amplifying mucosal inflammation therefore seems to be crucial for the development of new diagnostic and therapeutic tools. In an effort to extend knowledge in this area, the WP 2.7.2 of the GA(2)LEN network of excellence currently collects data and samples of 1000 CRS patients and 250 control subjects. The main objective of this project is to characterize patients with upper airway disease on the basis of clinical parameters, infectious agents, inflammatory mechanisms and remodeling processes. This collaborative research will result in better knowledge on patient phenotypes, pathomechanisms, and subtypes in chronic rhinosinusitis. This review summarizes the state of the art on chronic rhinosinusitis and nasal polyposis in different aspects of the disease. It defines potential gaps in the current research, and points to future research perspectives and targets.

Activated mammalian target of rapamycin is associated with T regulatory cell insufficiency in nasal polyps

BACKGROUND

Decreased infiltration of Foxp3+ T regulatory cell (Treg) is considered to be critical for the Th1/Th2 dysregulation of nasal polyps, while the cellular mechanism underlying Foxp3+ Treg insufficiency is currently not well defined.

METHODS

We attempted to investigate the tissue expression of phosphorylated mammalian target of rapamycin (pmTOR) and infiltration of Foxp3+ Tregs in 28 nasal polyps and 16 controls by histological staining. We also evaluated the effects of blocking the mTOR signaling pathway with rapamycin on T cell phenotype selection and Foxp3+CD4+ Tregs expansion in a tissue culture system.

RESULTS

Significantly increased infiltration of pmTOR+ inflammatory cells and decreased infiltration of Foxp3+CD4+ Tregs into nasal polyps was observed, with an inverse association. In the tissue culture system, we detected significantly elevated Foxp3 expression and IL-10 production, as well as an increased percentage of Foxp3+ Tregs in nasal polyps after blocking the mTOR signaling pathway with rapamycin.

CONCLUSION

Here we demonstrate for the first time that the mTOR signaling pathway is associated with Foxp3+ Tregs insufficiency in nasal polyps. Inhibition of the mTOR signaling pathway may be helpful for enhancement of Foxp3+ Treg expansion, as well as modulation of T cell phenotype imbalances in nasal polyps.

[Role of IFN-gamma and TNF-alpha in etiology of nasal polyps--initial studies]

OBJECTIVE

Nasal polyposis is a chronic inflammatory disease of the nasal mucosa. The pathogenesis of nasal polyps is still not entirely known and has been debated for many years. The aim of the present study was to evaluate the expression of interferon gamma and TNF-alpha secreted by Th1 lymphocytes and to analyze their role in the etiology of nasal polyps.

METHODS

12 patients with nasal polyposis were selected - 6 of them allergic and 6 non-allergic. Patients with allergy were distinguished from those without allergy on the basis of positive allergy skin tests to dust and serum levels of IgE. Blood sample was obtained from patients and examined for the expression of IFN-gamma and TNF-alpha by intracellular staining procedure after stimulation with PMA/ionomycin and allergen.

RESULTS

Negative correlation was found between expression of IFN-gamma and TNF-alpha after PMA/ionomycin stimulation and allergen stimulation (p > 0,05). Statistical analysis of two groups of patients demonstrated that no significant differences in the cytokine expression in allergic versus non-allergic patients were observed although mean value of IFN-gamma and TNF-alpha were lower in allergic patients in comparison to non-allergic (p > 0,05). We didn't observed any correlation between expression of INF-gamma and TNF-alpha and: coexistence of bronchial asthma, allergy to aspirin and local corticosteroid treatment. In patients with recurrent polyposis the expression of INF-gamma was significantly lower (p = 0,05).

CONCLUSION

This research suggests that IFN-gamma and TNF-alpha play a role in the pathogenesis of nasal polyps but the allergic mechanism may not play a fundamental role in this process. It needs further investigations.

The role of allergy in the severity of nasal polyposis

BACKGROUND

Although patients with nasal polyposis frequently exhibit concomitant allergy, there is limited information about the impact of allergy on the severity of nasal polyposis. The goal of this study was to evaluate the role of allergy in the severity of nasal polyposis.

METHODS

Polyp sizes, computed tomography (CT) scores, skin-prick test results, blood total eosinophil count, serum levels of total immunoglobulin E, symptom scores, and recurrences were analyzed in 83 patients with nasal polyposis. The results were compared between allergic and nonallergic patients with nasal polyposis.

RESULTS

No association was found between the presence of allergy per skin-prick testing and polyp size, CT opacification, symptom scores, or recurrences (p > 0.05). In allergic patients, only the serum total eosinophil count correlated strongly with the results of CT (p = 0.005) but not with other parameters (p > 0.05).

CONCLUSIONS

The results of this study show that, although patients with nasal polyposis frequently have allergies, the presence of allergy does not correlate with polyp size, symptom scores or rate of recurrence.

Inflammatory genes in nasal polyposis

PURPOSE OF REVIEW

This paper is a review of the most recent literature concerning the role of inflammatory genes in nasal polyposis. The data provide evidence of a pivotal role for some inflammatory mediators in the development and maintenance of nasal polyps.

RECENT FINDINGS

Nasal polyposis is a common disease of the nasal mucosa; the exact mechanisms leading its development are still unknown. The role of the immune system in the pathogenesis of this disease is poorly understood. This lack of understanding makes definitive treatment very difficult. Activated eosinophils are a prominent feature of nasal polyps. Their presence in tissue results from a complex series of events that regulates their influx from the vasculature, as well as their movement, activation and survival within the tissue. Several studies have demonstrated that there are many potent chemoattractants that can activate eosinophils and trigger the inflammatory response.

SUMMARY

Cytokines, chemokines and growth factors play an important role in the persistence of mucosal inflammation associated with nasal polyps. Metalloproteinases seem to be crucial in nasal tissue remodeling in these patients. Arachidonic acid metabolites seem to be particularly important in the pathogenesis of nasal polyps in patients with aspirin hypersensitivity. We discuss the contribution of each one for the polyp formation.

Chronic rhinosinusitis and psoriasis: do mutually exclusive systemic Th1 and Th2 disease patterns exist?

CONCLUSION

Our results support the theory that chronic rhinosinusitis (CRS) is a systemic Th alteration, the relevance of which is discussed in detail.

OBJECTIVE

CRS imposes a heavy burden on society; however, a reliable CRS therapy has not been found. Developing a better understanding of this pathology will help us in our search for more effective therapies. One question, which is rarely examined, is the possibility of CRS existing as a systemic immune alteration in Th response. Thus, the goal of this study was to examine the occurrence of CRS, a Th2 pathology, with Th1 pathologies such as psoriasis.

PATIENTS AND METHODS

This study was performed via a retrospective electronic query of our medical center in regards to patients coded with the respective diagnosis.

RESULTS

Analysis of the data showed that occurrence of CRS rarely coincided with the occurrence of psoriasis and other such Th1 pathologies.

Innate responses to Aspergillus: role of C1q and pentraxin 3 in nasal polyposis

BACKGROUND

Pentraxin 3 (PTX3) and complement component C1q are humoral factors of innate immunity, produced at sites of inflammation, and are essential in immune defense against several microbes such as Aspergillus, which is commonly implicated in nasal polyposis.

METHODS

PTX3 and C1q were measured in nasal polyp tissue, normal nasal mucosa, and serum of patients and healthy subjects. Immunohistochemistry for the two proteins was done on normal nasal mucosa and nasal polyps. In addition, PTX3 and C1q production from mononuclear cells from patients and healthy subjects was assessed.

RESULTS

Normal nasal mucosa was found to have 100-fold higher levels of PTX3 compared with serum. No measurable local increase of PTX3 was observed in polyps compared with normal mucosa. Immunohistochemistry revealed PTX3 expression in the lining of blood vessels both within normal mucosa and nasal polyps. PTX3 also was present in mononuclear cells infiltrating nasal polyps. C1q levels were higher in polyps than in normal nasal mucosa.

CONCLUSION

High levels of PTX3 are present in normal nasal mucosa, suggesting a role in the maintenance of tissue homeostasis. Elevated C1q levels in nasal polyps might be indicative of an ongoing inflammatory response in the nasal mucosa in these patients.

Innate immunity of the sinonasal cavity and its role in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is one of the most common health problems in the United States. Medical therapy and surgery are successful in treating the majority of patients with sinusitis; however, CRS patients recalcitrant to traditional therapy are increasingly prevalent. Although traditionally this illness could be explained by sinus ostial obstruction and persistent bacterial infection, the rhinologic literature over the years has suggested a significant underlying inflammatory component. Adaptive immune components, including lymphocytes and their associated cytokines, have been the subject of most research in chronic nasal inflammation. A recent appreciation of the importance of the innate immune system is leading to new areas of investigation regarding the pathogenesis of CRS. This review will outline our current knowledge of sinonasal innate immunity, the role of innate immunity in the pathogenesis of CRS, and potential therapeutic targets in the innate immune system.

Distinct features of chronic rhinosinusitis with and without nasal polyps

BACKGROUND

Based on the presence of nasal polyps on endoscopy, chronic rhinosinusitis (CRS) may be clinically divided in CRS with nasal polyps and CRS without nasal polyps. It is unclear, whether CRS with nasal polyps and CRS without nasal polyps represent different disease entities or just different stages of one single disease. In case of one disease, only minor histopathological differences between CRS with small early-stage polyps (CRSNP((+))) and CRS without nasal polyps (CRSNP(-)) were expected.

METHODS

Patients with CRSNP((+)) confined to the infundibular region or CRSNP(-) were selected. Histochemical and immunohistochemical characterization of ethmoidal mucosa was performed on formalin-fixed and paraffin-embedded tissue specimens. Frequency and distribution of eosinophils, neutrophils, mast cells, IgE(+) cells, macrophages, B- and T-cell subsets, natural killer cells, plasma cells and goblet cells were assessed. In addition, the thickness of the basal membrane was evaluated.

RESULTS

Nine CRS patients without detectable polyps, and 11 patients with small early-stage polyps confined to the infundibular region were selected. Despite adjacent polyp stage, the amount of round cell infiltration (P < 0.05), number of eosinophils (P < 0.05), and plasma cells (P < 0.01) significantly differed in the ethmoidal specimens from patients of the two groups.

CONCLUSION

Substantial histopathological differences were observed in ethmoidal mucosa of CRSNP((+)) and CRSNP(-) patients. Thus, the results of this investigation support the concept that CRS with nasal polyps and CRS without nasal polyps are two different disease entities rather than different stages of one single disease, but may also be interpreted as a higher degree of inflammation.

Nasal polyp diseases in allergic and nonallergic patients and steroid therapy

OBJECTIVE

To investigate widespread disease causes, cellular-structural differences, and steroid response of nasal polyps (NPs).

METHOD

Study group consisted of NPs, allergic-NPs, NPs with steroid therapy (ST), antrochoanal polyp (ACP), and controls. We investigated stromal eosinophil, mast cell, CD4+ and CD8+ cell counts and presence of squamous metaplasia, Ki-67 expression, intraepithelial eosinophils-mast cells, epithelial damage, edema, fibrosis, hyalinization, polymorphonuclear leukocyte, and glandular hyperplasia.

RESULTS

In allergic-NPs, intraepithelial eosinophils and epithelial damage CD4+ were significantly higher than NPs and also, eosinophils, mast cells, intraepithelial eosinophils, and epithelial damage were significantly higher than ACP. Only stromal eosinophilic infiltration was significantly higher in NPs than ACP. There was significant increased glandular hyperplasia and decreased intraepithelial eosinophils, mast cells, CD4+ cells, squamous metaplasia, and epithelial damage with ST in allergic-NPs. There were no significant differences with ST in NPs.

CONCLUSION

NPs in allergic and nonallergic patients may differ in their histology and in their histologic responses to ST.

EBM RATING

B-3b.

Ultrastructural investigation of epithelial damage in asthmatic and non-asthmatic nasal polyps

Nasal polyposis is a poorly understood chronic inflammatory disease often associated with asthma. As nasal polyps and asthma both are associated with massive eosinophil infiltration, they may share a common pathophysiological mechanism. Many genetic and autoimmune diseases may result from altered expression or function of cell adhesion molecules such as desmosomes. A transmission electron microscopical study was carried out on tissue from 15 patients suffering from nasal polyps, to investigate if there are changes in desmosomes in nasal polyps from asthmatic and/or allergic patients versus non-asthmatic versus non-allergic patients. In allergic patients the damage to columnar cells was more extensive than in non-allergic patients. Massive infiltration of eosinophils was observed in epithelium and connective tissue in all groups. No significant difference in thickness of the basal lamina was found between any of the groups. All patients had dilated capillaries in the connective tissue. The intercellular space between the epithelial cells was smallest in the asthmatic non-allergic group. The relative length of columnar cell or basal cell desmosomes was reduced in patients with asthma or allergy, compared to non-allergic, non-asthmatic patients. Hence, there appears to be a weakness in the desmosomes in asthmatics and allergics. Epithelial shedding may play an important role in the pathophysiological process of a multifactorial disease such as asthma.

Update on the molecular biology of nasal polyposis

The definition of CRS with and without nasal polyposis continues to evolve. It may require an understanding of a broader range of etiologies and pathogenesis than bacterial or viral infection. One must know whether the inflammation is of infectious or noninfectious origin. Therapeutic options will include pharmacotherapies and surgery. The pharmacotherapeutic approach will include antibiotics, systemic and topical steroids, possibly antifungals, novel anti-inflammatory therapies such as the use of antibodies directed against inflammatory cytokines and antileukotrienes, and perhaps low-dose macrolide therapy. In the case of massive nasal polyposis, modern surgical techniques will have to be performed before these therapeutic options will be possible. Finally, the use of topical diuretics such as amiloride and furosemide has been studied and the initial responses seem to be encouraging.

Potential New Avenues of Treatment for Chronic Rhinosinusitis: an Anti-inflammatory Approach

Chronic rhinosinusitis is a complex disease process, one that is characterized by much more than just infection. Until its pathophysiology is understood fully, truly definitive therapy may remain elusive. As this underlying inflammatory process begins to unravel, however, new avenues of therapy will begin to emerge. This article discusses some of these new therapies and provides some clues as to where future avenues may go.

Downregulation of peroxisome proliferator-activated receptors (PPARs) in nasal polyposis

Background

Peroxisome proliferator-activated receptor (PPAR) α, βδ and γ are nuclear receptors activated by fatty acid metabolites. An anti-inflammatory role for these receptors in airway inflammation has been suggested.

Methods

Nasal biopsies were obtained from 10 healthy volunteers and 10 patients with symptomatic allergic rhinitis. Nasal polyps were obtained from 22 patients, before and after 4 weeks of local steroid treatment (fluticasone). Real-time RT-PCR was used for mRNA quantification and immunohistochemistry for protein localization and quantification.

Results

mRNA expression of PPARα, PPARβδ, PPARγ was found in all specimens. No differences in the expression of PPARs were obtained in nasal biopsies from patients with allergic rhinitis and healthy volunteers. Nasal polyps exhibited lower levels of PPARα and PPARγ than normal nasal mucosa and these levels were, for PPARγ, further reduced following steroid treatment. PPARγ immunoreactivity was detected in the epithelium, but also found in smooth muscle of blood vessels, glandular acini and inflammatory cells. Quantitative evaluation of the epithelial immunostaining revealed no differences between nasal biopsies from patients with allergic rhinitis and healthy volunteers. In polyps, the PPARγ immunoreactivity was lower than in nasal mucosa and further decreased after steroid treatment.

Conclusion

The down-regulation of PPARγ, in nasal polyposis but not in turbinates during symptomatic seasonal rhinitis, suggests that PPARγ might be of importance in long standing inflammations.