Inflammatory cells in nasal mucosa and nasal polyps

Emissions from modern engines induce distinct effects in human olfactory mucosa cells, depending on fuel and aftertreatment

Ultrafine particles (UFP) with a diameter of ≤0.1 μm, are contributors to ambient air pollution and derived mainly from traffic emissions, yet their health effects remain poorly characterized. The olfactory mucosa (OM) is located at the rooftop of the nasal cavity and directly exposed to both the environment and the brain. Mounting evidence suggests that pollutant particles affect the brain through the olfactory tract, however, the exact cellular mechanisms of how the OM responds to air pollutants remain poorly known. Here we show that the responses of primary human OM cells are altered upon exposure to UFPs and that different fuels and engines elicit different adverse effects. We used UFPs collected from exhausts of a heavy-duty-engine run with renewable diesel (A0) and fossil diesel (A20), and from a modern diesel vehicle run with renewable diesel (Euro6) and compared their health effects on the OM cells by assessing cellular processes on the functional and transcriptomic levels. Quantification revealed all samples as UFPs with the majority of particles being ≤0.1 μm by an aerodynamic diameter. Exposure to A0 and A20 induced substantial alterations in processes associated with inflammatory response, xenobiotic metabolism, olfactory signaling, and epithelial integrity. Euro6 caused only negligible changes, demonstrating the efficacy of aftertreatment devices. Furthermore, when compared to A20, A0 elicited less pronounced effects on OM cells, suggesting renewable diesel induces less adverse effects in OM cells. Prior studies and these results suggest that PAHs may disturb the inflammatory process and xenobiotic metabolism in the OM and that UFPs might mediate harmful effects on the brain through the olfactory route. This study provides important information on the adverse effects of UFPs in a human-based in vitro model, therefore providing new insight to form the basis for mitigation and preventive actions against the possible toxicological impairments caused by UFP exposure.

Extrafollicular IgD+ B cells generate IgE antibody secreting cells in the nasal mucosa

Increased IgE is a typical feature of allergic rhinitis. Local class-switch recombination has been intimated but B cell precursors and mechanisms remain elusive. Here we describe the dynamics underlying the generation of IgE-antibody secreting cells (ASC) in human nasal polyps (NP), mucosal tissues rich in ASC without germinal centers (GC). Using VH next generation sequencing, we identified an extrafollicular (EF) mucosal IgD+ naïve-like intermediate B cell population with high connectivity to the mucosal IgE ASC. Mucosal IgD+ B cells, express germline epsilon transcripts and predominantly co-express IgM. However, a small but significant fraction co-express IgG or IgA instead which also show connectivity to ASC IgE. Phenotypically, NP IgD+ B cells display an activated profile and molecular evidence of BCR engagement. Transcriptionally, mucosal IgD+ B cells reveal an intermediate profile between naïve B cells and ASC. Single cell IgE ASC analysis demonstrates lower mutational frequencies relative to IgG, IgA, and IgD ASC consistent with IgE ASC derivation from mucosal IgD+ B cell with low mutational load. In conclusion, we describe a novel mechanism of GC-independent, extrafollicular IgE ASC formation at the nasal mucosa whereby activated IgD+ naïve B cells locally undergo direct and indirect (through IgG and IgA), IgE class switch.

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.

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.

Evaluation of Telomerase Activity in Nasal Polyps

Background

The objective of this study was to assess if nasal polyps express telomerase activity and whether a difference could be found between the polyp and the surrounding mucosa of the middle meatus and between different portions of the polyp itself.

Methods

Nine patients affected by nasal polyposis were included in this study; four of these patients had recurring polyposis. Telomerase activity was measured by telomeric repeat amplification protocol assay. In six patients, the telomeric repeat amplification protocol assay was performed on the polyp and on the mucosa from the ipsilateral middle meatus. In a polyp, we were able to investigate telomerase activity of its different portions, corresponding to pedicle and fundus.

Results

Telomerase activity observed in nasal polyps was higher than that observed in samples from the ipsilateral middle meatus mucosa. High or intermediate telomerase activity was found to be related to predominant recurring polyposis.

Conclusion

Therefore, it could be postulated that telomerase activity could be related with the tendency of polyps to recur.

Acquired Immunity in Chronic Rhinosinusitis

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

Intranasal immunization with dry powder vaccines

Vaccination represents a cost-effective weapon for disease prevention and has proven to dramatically reduce the incidences of several diseases that once were responsible for significant mortality and morbidity worldwide. The nasal cavity constitutes the initial stage of the respiratory system and the first contact with inhaled pathogens. The intranasal (IN) route for vaccine administration is an attractive alternative to injection, due to the ease of administration as well as better patient compliance. Many published studies have demonstrated the safety and effectiveness of IN immunization with liquid vaccines. Currently, two liquid IN vaccines are available and both contain live attenuated influenza viruses. FluMist® was approved in 2003 in the United States, and Nasovac® H1N1 vaccine was approved in India in 2010. Preclinical studies showed that IN immunization with dry powder vaccines (DPVs) is feasible. Although there is not a commercially available DPV yet, DPVs have the inherent advantage of being relatively more stable than liquid vaccines. This review focuses on recent developments of DPVs as next-generation IN vaccines.

[Medically-induced rhinitis]

This paper summarizes the currently accepted concepts of the pathogenetic mechanisms underlying the morphological and functional changes in intranasal mucosa of the patients having a long history of the application of the long-acting topical vasoconstrictor agents. The author presents the data illustrating the effectiveness of various methods for the pharmacotherapeutic treatment of medically-induced rhinitis.

Could Eosinophilia predict clinical severity in nasal polyps?

Background

Although nasal polyps are one of the most frequent diseases, their etiopathogenesis remains unclear.Since eosinophils are the main inflammatory cells in the substantial proportion of nasal polyp tissues, they are considered potentially responsible for the etiopathogenesis and prognosis of the disease. Aim of this study was to investigate the relation between mucosal and peripheral eosinophilia and their relation with disease severity in nasal polyps.

Methods

The study included 53 patients with nasal polyps who underwent endoscopic sinus surgery. Preoperative Lund-MacKay computed tomography (CT) scores and the Lund-Kennedy endoscopic scores of the patients were recorded. Nasal polyp tissues were stained with hematoxylin and eosin, eosinophil counts were performed using high-power field (HPF, 400×) under the light microscope, and the patients were grouped as those with high mucosal eosinophil count and those with low mucosal eosinophil count.

Results

The mean Lund-MacKay CT score and the mean Lund-Kennedy endoscopic score were higher in the patients with high mucosal eosinophil count than in those with low mucosal eosinophil count. Likewise, the mean Lund-MacKay CT score and the mean Lund-Kennedy endoscopic scores were significantly higher in the patients with high peripheral eosinophil count than in those with low peripheral eosinophil count (p < 0.05 for both). Moreover, the mean peripheral eosinophil count was significantly higher in the patients with high mucosal eosinophil count than in those with low mucosal eosinophil count (p < 0.05).

Conclusion

Mucosal and peripheral eosinophilia can be used as a marker to predict disease severity in nasal polyps.

Methotrexate Induces Apoptosis in Organ-Cultured Nasal Polyps Via the Fas Pathway

OBJECTIVE

Methotrexate (MTX) is very effective when used to treat chronic inflammatory diseases, and also induces apoptosis in nasal polyps (NPs). Increasing evidence suggests that Fas-Fas ligand (FasL) interactions activate multiple pathways involved in the regulation of immune and inflammatory cell functions. The aim of the present study was to identify pathways activated by Fas signaling when NPs were treated with MTX.

METHODS

Nasal polyps tissues were cultured using an air-liquid interface organ culture method. Cultures were maintained in the absence or presence of MTX (10 or 100 μM) for 24 hours. The authors used the reverse transcription-polymerase chain reaction method and Western blotting to identify pathways activated by Fas when NPs were treated with MTX.

RESULTS

The Fas mRNA expression ratio was unchanged upon MTX treatment, but the FasL mRNA expression ratio was significantly higher in MTX-treated than nontreated polyps. In addition, the expression levels of the Fas and FasL proteins were significantly higher in polyps treated with both 10 and 100 μM MTX compared with nontreated polyps.

CONCLUSIONS

Methotrexate induces apoptosis in NPs via the Fas pathway. Future studies should explore the topical use of MTX for NP control. Methotrexate may be a useful alternative steroid-sparing agent for the treatment of NPs.

Expression Profile of Immune-Associated Genes in Nasal Polyps

Objectives:

We performed this study to investigate the expression profile of immune-associated genes and to probe the role of related genes in the immune pathogenesis of nasal polyps.

Methods:

Microarray analysis was used to find the expression profile of 491 immune-associated genes in nasal polyps. In validation studies, immunohistochemical staining and Western blot analysis were used to detect interleukin (IL)–17 and IL-17 receptor (IL-17R) in nasal polyps and controls.

Results:

Eighty-seven genes were differentially expressed in the immune-associated gene profile of nasal polyps, and 15 genes showed differential expression in both chips. In nasal polyp tissues, IL-17 was expressed mainly in the cytoplasm of plasma cells and to a lesser degree in the prickle cell layer of the epithelium and the acinus of the serous gland. In turbinates, IL-17 was also expressed in the same location, but the expression of IL-17 in nasal polyps and that in turbinates differed significantly (p > .05). Both IL-17 and IL-17R displayed specific bands in nasal polyps and turbinates, but the bands of IL-17 and IL-17R in nasal polyps were stronger than those in turbinates.

Conclusions:

The differentially expressed genes in immune-associated gene chips will provide clues about, and a theoretical foundation for, the pathogenesis of nasal polyps. Furthermore, IL-17 may play an important role in the occurrence of nasal polyps by overexpression.

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.

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.

Cellular comparison of sinus mucosa vs polyp tissue from a single sinus cavity in chronic rhinosinusitis

BACKGROUND

Nasal polyposis is a common development in chronic rhinosinusitis (CRS), and sinus mucosa and polyp tissue have been used interchangeably in studies investigating CRS. However, potential differences may exist between these 2 tissue types, which have not been entirely characterized.

METHODS

A cross-sectional study of CRS with nasal polyposis (CRSwNP) patients undergoing endoscopic sinus surgery was conducted. Sinus mucosal biopsies and corresponding polyp tissue were obtained from the same sinus cavity via flow cytometry, single-cell suspensions identified type 2 innate lymphoid cells (ILC2s), CD4 and CD8 T cells, activated CD4 and CD8 T cells, plasma cells, plasmacytoid dendritic cells (pDCs), regulatory T cells, T follicular helper cells, B cells, and immunoglobulin A (IgA)(+) and IgG(+) B cells. Cells were measured as a percentage of CD45(+) cells. Paired nonparametric comparisons between sinus and polyp tissue were performed.

RESULTS

Ten patients (50% female; age 48 ± 16 years) were recruited. Significantly elevated ILC2 levels were found in polyp tissue compared to sinus mucosa (0.12 [0.07 to 0.23] vs 0.07 [0.04 to 0.16], p = 0.02), as well as plasma cells (2.25 [0.84 to 3.68] vs 1.18 [0.74 to 2.41], p = 0.01); pDCs (0.15 [0.12 to 0.50[ vs 0.04 [0.02 to 0.17], p = 0.03); activated CD8 T cells (29.22 [17.60 to 41.43] vs 16.32 [10.07 to 36.16], p = 0.04) and IgG(+) B cells (6.96 [0.06 to 11.82] vs 1.51 [0.38 to 5.13], p = 0.04). Other cell populations showed no significant differences.

CONCLUSION

Polyps have a similar cellular composition to that of mucosa. Higher levels of ILC2s, plasma cells, pDCs, activated CD8 T cells, and IgG(+) B cells in polyp tissue may be reflective of cell populations driving nasal polyp development. The cellular machinery of CRS is present in polyps and representative of the disease process. This pilot study strongly suggests that a larger study would provide significant insights into the relationship of sinus mucosa to pathogenesis of nasal polyps.

Surgical treatment of nasal polyposis: a comparison between cutting forceps and microdebrider

BACKGROUND

Nasal polyposis (NP) is defined as a specific form of chronic rhinosinusitis (CRS), characterized by bilateral and multifocal polyps. Functional endoscopic sinus surgery represents the gold standard therapy when medical treatment fails. The availability of different tools raises the question of which one provides significant advances in technique and surgical outcome. This study considered the outcome of the surgical treatment of NP in relation to several comorbidities and the surgical device used: the microdebrider versus the Blakesley traditional forceps. Other studies compared the two instruments but did not evaluate the clinical relevance of history of comorbidities such as asthma, allergy, and eosinophilia.

METHODS

A prospective randomized single-blind study was designed to analyze 311 cases of bilateral CRS with NP. Each patient served as his/her own control, meaning that one side was operated on using the Blakesley forceps and the opposite side using the microdebrider. The follow-up period was 13.3 ± 1.2 months.

RESULTS

The Blakesley forceps caused a significantly lower NP recurrence rate than the microdebrider (p < 0.001), which was more effective in preventing synechia formation (p < 0.05). Only asthma was significantly associated with a higher recurrence rate, without being influenced by the instrument used (p < 0.001).

CONCLUSION

The manual instrument allowed for a significantly lower recurrence incidence but yielded a higher rate of synechia formation compared with the microdebrider. Only asthma was significantly associated with a poorer clinical outcome, and gender, age, allergy, and eosinophilia did not affect the surgical prognosis.

Relationship of eosinophils and plasma cells to biofilm in chronic rhinosinusitis

BACKGROUND

This study investigates the relationship of eosinophils and plasma cells to biofilm in chronic rhinosinusitis (CRS). A prospective observational study was performed at the Keck Hospital, University of Southern California, Department of Otolaryngology, Los Angeles, CA.

METHODS

A total of 29 patients, 20 undergoing endoscopic sinus surgery for CRS and 9 control patients undergoing septoplasty for nasal obstruction without history or evidence of CRS, were included in this study. Contiguous sinonasal mucosa sample sections were examined by hematoxylin and eosin (H&E), fluorescence in situ hybridization (FISH), and immunohistochemistry (IHC) for biofilm, microbes, eosinophil major basic protein (EMBP), and cluster designation 27 (CD27). EMBP and CD27 were used as eosinophil and plasma cell markers, respectively.

RESULTS

Biofilm was visualized in 15 of 20 patients with CRS on H&E sections, confirmed by microbial presence using FISH. Biofilm was not identified in tissue samples of the nine control patients. On IHC analysis, CD27 and EMBP expression were significantly higher in patients with CRS compared with control (p < 0.05) and had greater expression in biofilm-positive patients compared with biofilm-negative patients. Nasal polyps correlated with higher expression of CD27 and EMBP, but in CRS patients without polyps CD27 and EMBP was also significantly greater in biofilm-positive specimens compared with biofilm-negative specimens.

CONCLUSION

Biofilm presence in CRS appears to correlate to host inflammatory response involving plasma cell and eosinophil recruitment.

Nod-like receptors in head and neck squamous cell carcinoma

CONCLUSION

The capability of Nod1 to recognize bacteria along with its altered expression and ability to cause an immunological response in head and neck cancer suggest a novel pathway for bacteria to interfere with ongoing cancer inflammation.

OBJECTIVE

Nucleotide oligomerization domain (Nod)-like receptors (NLRs) comprise a recently discovered family of pattern-recognition receptors. In addition to their protective function against infections, accumulating evidence suggests a role for these receptors in various diseases, including cancer. The present study was designed to explore the presence of NLRs in head and neck squamous cell carcinoma, and to determine if these cells have the ability to respond immunologically to ligand stimulation.

METHODS

The pharyngeal squamous cell carcinoma cell lines Detroit-562 and FaDu were used as a model for head and neck cancer, and compared to healthy primary human nasal epithelial cells. Analyses were performed using immunohistochemistry, real-time RT-PCR, Luminex Multiplex Immunoassay, ELISA, and flow cytometry.

RESULTS

The expression profile of NLRs in head and neck cancer cells differed from that seen in healthy epithelial cells. Further, Nod1 stimulation induced an immunological response in tumor cells that differed from the response in normal epithelial cells, especially regarding the expression of β-defensin 2, granulocyte monocyte colony stimulating factor (GM-CSF), granulocyte colony stimulating factor (G-CSF), intercellular adhesion molecule-1 (ICAM-1), and cell survival.

Expression and distribution of dendritic cells in nasal polyps

The aim of the present study was to investigate the expression, distribution and function of dendritic cells (DCs) and to study their role in nasal polyps. The study involved 55 participants, 45 of whom had nasal polyps and were the study group and 10 who had normal inferior turbinates and were the control group. Immunohistochemical staining was used to visualize the expression and distribution of the S-100 protein. A double immunostaining method was used to visualize the CD1a and CD40 expression and the images were analyzed with Axioplan 2 microscopy. The expression level of the S-100 protein in the nasal polyps was higher than that in the normal inferior turbinates with a significant difference (P<0.01). The distribution area, number and density of the double stained cells in the nasal polyps were all greater than in the normal inferior turbinates (P<0.01). The S-100 protein and double stained cells were mainly located in the lamina propria below the mucous membrane. The present study demonstrates that DCs are involved in the pathogenesis of nasal polyps and the presence of CD40-positive DCs suggests that this was related to the reciprocal interaction between the DCs and T lymphocytes.

Evaluation of ceruloplasmin levels in patients undergoing surgical interventions with nasal polyps

OBJECTIVE

Oxidative stress is believed to have a role in the development of nasal polyps (NPs). It is also known that ceruloplasmin (CP), an acute phase protein, limits oxidative stress. The purpose of this study was to evaluate the ceruloplasmin levels in patients with NPs.

METHODS

One hundred and twenty patients with NPs, septal deviations and concha hypertrophies were recruited to the study. Patients were divided in two groups; group 1 (n=60) consisted of patients with NPs, and group 2 (n=60) consisted of septal deviations and concha hypertrophies. Polyp specimens were taken from all patients who underwent endoscopic surgery due to NPs, as well as control specimens were acquired who underwent an operation due to septoplasty or concha hypertrophy. Blood and tissue samples were obtained to assess CP levels.

RESULTS

There were no statistical differences in gender, age and biochemical values between two groups (p>0.05 for all). Compared to group 2, group 1 had significantly higher CP levels both in serum and the tissue samples (both p<0.001).

CONCLUSION

As a result of our study; CP levels both in serum and the tissue in patients with NPs were higher, may be consequence of the inflammation, than in patients without NPs.

Epidemiological analysis of chronic rhinitis in pediatric patients

BACKGROUND

Nonallergic rhinitis is a poorly understood entity, especially among pediatric patients.

OBJECTIVE

The objective of this study was to identify clinical features that may distinguish phenotypes of allergic and nonallergic patients and to evaluate the usefulness of current diagnostic modalities.

METHODS

We reviewed medical records for 151 pediatric patients with perennial rhinitis, evaluated in a multidisciplinary allergy and otolaryngology clinic. Results obtained by standard history, validated sinus and Nasal Quality of Life Survey (SN-5), epicutaneous allergy testing, acoustic rhinometry, and sinus CT were compared.

RESULTS

Nasal congestion was the most frequent primary presenting complaint (62%). Among subjects having a positive allergy test, associated eye symptoms were more frequent (p = 0.01) and responses to the SN-5 allergic domain were higher (p = 0.02). Sinus CT scores were similar among allergic and nonallergic subjects (median 7 and 8, respectively) and did not correlate with symptom scores (p = 0.6). Among nonallergic subjects, quality of life ratings weakly correlated with sinus CT scores (r = 0.4; p = 0.05). By rhinometry, absolute mean cross-sectional area was similar among allergic (0.32 cm(2)) and nonallergic (0.36 cm(2)) subjects and did not correlate with symptom scores (p = 0.8 for allergic and p = 0.6 for nonallergic subjects). Distinct groups of nonallergic patients including those with prominent conjunctival pruritus (n = 24), frequent cold symptoms (n = 3), and chronic sinus disease (n = 2) were observed.

CONCLUSION

It is difficult to distinguish allergic and nonallergic rhinitis in patients with perennial disease, but associated eye symptoms and questionnaire responses are predictive of allergy. Acoustic rhinometry and sinus CT suggest that physical obstruction and sinus disease are not related to nasal symptoms including, surprisingly, the sensation of congestion.

Could cellular proliferation be a predictive index for the relapse of nasal polyposis and down-regulated by nasal steroid treatment?

The aim of this article is to identify the cellular mitotic activity using Ki-67 monoclonal antibody for predicting relapses of nasal polyposis after surgery. A prospective study was conducted at Kartal Training and Research Hospital Otolaryngology Department between January 2006 and September 2008. Nasal polyps were obtained from all patients and pathological materials were analyzed for the Ki-67 staining using immunohistochemistry. Patients were followed after surgery for 12 months for relapse. There was no statistically significant difference between recurrent and nonrecurrent polyps. Polyp recurrence has a multifactorial origin. Ki-67 index alone does not provide sufficient information about polyp recurrence before the operation.

Peroxisome proliferator-activated receptor-γ is expressed in eosinophils in nasal polyps

BACKGROUND

Peroxisome proliferator-activated receptor-γ (PPARγ) is a member of the nuclear receptors, which regulate fatty acid metabolites. One of the natural ligands for PPARγ is 15-deoxy-Δ(12,14)-prostaglandin J(2) (15d-PGJ(2)), a major metabolite of prostaglandin D(2) (PGD(2)). Recently, PPARγ has been shown to play an important role in anti-inflammatory reactions, including within-airway allergic diseases, in a mouse model. Our aim was to clarify the expression and localization of PPARγ and PGD(2) synthase, which produces ligands of PPARγ, in nasal polyps by immunohistochemical analysis.

METHODS

Nasal polyps of chronic rhinosinusitis patients (6 asthmatic patients and 6 nonasthmatic patients) were obtained during surgery. May-Grünwald-Giemsa staining was performed to evaluate the eosinophil infiltration of the polyps. To identify the cells expressing PPARγ protein and PGD(2) synthase, double immunostaining was performed using anti-PPARγ antibody, monoclonal antileukocyte antibodies, and PGD(2) synthase antibody.

RESULTS

The number of eosinophils and the number of PPARγ-positive cells in the nasal polyps of the asthmatic patients were significantly higher than those in the nonasthmatic patients. PPARγ was expressed on eosinophils and T cells of the infiltrating cells in the nasal polyps. PGD(2) synthase was also expressed on PPARγ-positive cells.

CONCLUSION

PPARγ is involved in nasal polyposis pathogenesis, acting on eosinophils and T cells.

Myeloperoxydase expression in the pathogenesis of nasal polyps

Nasal polyps are benign mucosal protrusions that expand into the nasal cavity. There are no any etiological factors that may explain the pathogenesis of nasal polyps but currently inflammation continues to be the major factor. As a result of inflammation, neutrophils become activated and migrate to the inflammatory area and form their bactericidal effects by producing free oxygen radicals. The objective of our study is to investigate the expression of myeloperoxydase enzyme, which is usually an indicator of leukocyte infiltration and is responsible in the formation of free oxygen radicals in polyp tissues and to determine its role in the pathogenesis of nasal polyps.

Eosinophilic allergic polyp: a clinically oriented concept of nasal polyp

OBJECTIVE

Tissue eosinophilia is a hallmark of nasal polyposis. However, there is no universally accepted definition for eosinophilic nasal polyp. The aims of this study were to histologically analyze the inflammatory cell population in the nasal polyp and propose the concept of eosinophilic allergic polyp (EAP), a simple and objective concept that would be clinically and practically valuable.

STUDY DESIGN

A cohort study with histological analysis of tissue sections and chart review.

SETTING

A tertiary university hospital.

SUBJECTS AND METHODS

Nasal polyp tissues were harvested during routine endoscopic sinus surgery from a cohort of 118 patients. Total number of inflammatory cells, including eosinophils, was counted. The presence of allergy and asthma was assessed, which was then correlated with the histologic findings. To determine a criterion for EAP, a receiver operating characteristic curve was used to identify the best cutoff point, which was further validated by comparing the eosinophil proportion in each group with reference to the clinical parameters.

RESULTS

Eosinophil accounted for an average of 18.7% of all inflammatory cells. The proportion of nasal polyps with at least 1 or more eosinophil infiltration accounted for 90.7% of all nasal polyps. When the concept of EAP was applied, a tissue eosinophil count of 11% was found to be significant and clinically most useful. Using this criterion, the proportion of EAP among nasal polyps was 62.7%.

CONCLUSION

The authors suggest a tissue eosinophil proportion of more than 11% as a criterion for EAP, a clinically useful concept of nasal polyp that bears good correlation with asthma and allergy.

Do viscid secretions have a role in nasal polyp formation?

OBJECTIVES

We compared histologic findings on light microscopy of viscid secretions found in association with nasal polyps with those found in patients with chronic sinusitis without polyposis (CSWP). The differences might further understanding of nasal polyp pathogenesis.

METHODS

In a prospective controlled study, viscid secretions found in association with nasal polyps were collected at endoscopic sinus surgery. Retained secretions in patients with CSWP acted as a control group. Both were fixed in 10% formalin, processed, and examined with a light microscope.

RESULTS

Viscid secretions were encountered among nasal polyps in 25 of 132 patients (18.9%). Polyps containing multiloculated cysts filled with viscid secretions were found in 2 of them. Histologic examination of viscid secretions showed variable histologic pictures, ranging from a homogeneous material infiltrated with inflammatory cells, newly formed blood vessels, and bundles of collagen fibers to a well-developed connective tissue core covered with a respiratory epithelium in some areas. Histologic examination of retained secretions in patients with CSWP revealed amorphous material infiltrated with inflammatory cells with no further maturation or epithelial coverage.

CONCLUSIONS

Viscid secretions, originating from ruptured mucosal cysts, might represent the initial step in nasal polyp pathogenesis. The variable histologic pictures detected possibly reflect different stages in nasal polyp formation from these secretions. Factors postulated in nasal polyp etiopathogenesis might trigger maturation and changes in the morphological structure of these secretions.

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.

The role of allergy in rhinosinusitis

PURPOSE OF REVIEW

To examine the current evidence for IgE and non-IgE-mediated hypersensitivity mechanisms in acute and chronic rhinosinusitis.

RECENT FINDINGS

Epidemiological studies show that classical IgE-mediated allergy is present in a proportion of acute rhinosinusitis patients. There is conflicting evidence whether the prevalence of IgE-mediated allergy is greater in chronic rhinosinusitis than in individuals without chronic rhinosinusitis. Despite presence of classical IgE-mediated allergy, based on elevated allergen-specific serum IgE levels and positive skin prick tests, currently there is no direct evidence for allergy as a major cause of sinonasal inflammation in chronic rhinosinusitis. There is increasing evidence that non-IgE-mediated fungal hypersensitivity and nonallergic IgE-associated inflammation may contribute to the pathogenesis in some forms of chronic rhinosinusitis, including allergic fungal sinusitis. Specific IgE to bacterial superantigens may also be elevated in nasal polyps and modulate eosinophilic inflammation. Recent insights into mucosal immune mechanisms yield intriguing prospects for the roles of mucosal IgE, mast cells and non-IgE-mediated hypersensitivity mechanisms that require further examination in rhinosinusitis.

SUMMARY

There is a need for further immunological studies of the systemic and mucosal cellular and humoral mechanisms in well defined patient groups and controls to better understand the role of IgE and non-IgE-mediated hypersensitivity mechanisms and nonhypersensitivity functions of IgE in rhinosinusitis.

Organ culture at the air-liquid interface maintains structural and functional integrities of inflammatory and fibrovascular cells of nasal polyps

BACKGROUND

Both inflammatory and fibrovascular cells play an important role in development of nasal polyps (NPs). In this study, we have developed a culture system to maintain structural and functional integrities of submucosal cells in vitro.

METHODS

NP tissue was cultured on a gelatin sponge at air-liquid (AL) interface or was cultured in submerging. Tissues were analyzed for survival, structural integrity, and vascular endothelial growth factor (VEGF) expression.

RESULTS

Most cells of NPs cultured in submerging died within 3 days. In culture at the AL interface, epithelium as well as submucosa kept structural integrity during the culture period. RT-PCR and immunohistochemistry showed that submucosa cells displayed VEGF expression, which is a major inducer of angiogenesis and edema of NPs.

CONCLUSION

Our study is the first demonstration that organ culture of NPs at the AL interface retains integrity of both epithelium and submucosa and this culture method possibly will be used to study the pathogenesis of NPs.

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.

Pathogenesis of nasal polyps: an update

The cause of nasal polyp formation is still unknown. Genetic predisposition has been suggested, but there are scanty data to support such theories. Activated epithelial cells may be the major source of mediators inducing influx of inflammatory cells (mostly eosinophils) and proliferation and activation of fibroblasts leading to nasal polyp formation. Infectious agents (including viruses, bacteria, or fungi) may be potential primary factors activating nasal epithelial cells. Proinflammatory cytokines and growth factors play important roles in the persistence of mucosal inflammation associated with nasal polyps. Arachidonic acid metabolites seem to be particularly important in the pathogenesis of nasal polyps in patients with aspirin hypersensitivity rhinosinusitis/asthma syndrome.

Activated eosinophils in nasal polyps: a comparison of asthmatic and non-asthmatic patients

OBJECTIVES

There is a recognized clinical association between nasal polyps and asthma. Nasal polyps and the airways of asthmatic patients demonstrate marked eosinophilia suggesting that this inflammatory cell may have a key role to play in both conditions. The objective of this study was to determine whether nasal polyps from patients with asthma had a greater density of activated eosinophils than patients with no associated respiratory disease.

DESIGN

Archived specimens were retrieved from patients who had undergone nasal polyp surgery and their case notes reviewed. Activated eosinophils were identified using immunohistochemistry for a monoclonal antibody to secreted eosinophil cationic protein (EG2).

SETTING

Teaching hospital otolaryngology unit.

PARTICIPANTS

Consecutive patients who had undergone nasal polyp surgery in 1994 were recruited. The diagnosis of asthma was based on a documented physician diagnosis and appropriate drug treatment. Twenty-four asthmatic and 35 non-asthmatic patients were studied.

MAIN OUTCOME MEASURES

Eosinophil density was measured using a standardized counting technique.

RESULTS

Asthmatic patients were significantly more likely to have had previous polyp surgery (chi-square test: P < 0.05). Areas of intense eosinophilia were identified in all samples. There was a significant greater degree of activated eosinophilia in the asthmatic patients (t-test: P < 0.05).

CONCLUSIONS

We have demonstrated a higher number of previous operations in asthmatic patients, and also a greater degree of activated eosinophilia in asthmatic polyps compared with non-asthmatics. This would suggest that eosinophil activity has a role to play in the pathogenesis of nasal polyps.

Role of Leukotriene Inhibitors in the Postoperative Management of Nasal Polyps

This was a prospective double blind comparative study on 40 patients. It compared the effects of the leukotriene receptor antagonist montelukast and beclomethasone nasal spray on the post-operative course of patients with sinonasal polyps. All patients underwent endoscopic sphenoethmoidectomy and were randomized post-operatively into two groups. Group I: 20 patients (9 females and 11 males) age 17 to 67 (32.4 +/- 9.5 years), receiving 10 mg montelukast orally daily and Group II: 20 patients (6 females and 14 males) age 17 years to 57 years (33.5 +/- 11.9 years), receiving 400 ug beclomethasone local sprays daily. All patients were followed up for 1 year and a symptom score was recorded throughout this period. There was a significant reduction in symptom scores in both groups throughout the study period. In the montelukast group improvement was more marked in itching, post-nasal discharge and headache. The control of sneezing and rhinorrhea was comparable in both groups with a marginal advantage of montelukast. Steroids had a more marked effect on smell disturbances and obstruction. There was no difference in the recurrence rate or in the need for rescue medications between both groups. Both drugs seem to have a complementary action and further studies are needed to determine which patients should receive which treatment.

Inflammatory mediators and eosinophilia in atopic and non-atopic patients with nasal polyposis

Nasal polyps are characterized by eosinophilic infiltration and presence of inflammatory mediators, such as total IgE, eosinophil cationic protein (ECP) and cytokines. The role of atopy in nasal polyp pathogenesis is still unclear. Therefore, we evaluated serum IgE levels, nasal mucus concentrations of ECP and cytokines and the number of infiltrating eosinophils in nasal tissue of polyps from atopic and non-atopic patients. Samples were obtained from a randomized population of 31 patients with nasal polyposis having endonasal sinus surgery and of 13 control subjects undergone corrective surgery of the nasal septum. On the basis of medical history of allergy, positive skin-prick tests and total IgE levels, patients with polyposis were divided in atopic (n = 13) and non-atopic (n = 18) patients. We determined levels of IgE in blood, ECP and cytokines (IL-4, IL-6, IL-8, IFN-gamma and IL-2) in nasal mucus, and number of infiltrating eosinophils in nasal tissue. The concentrations of total IgE, ECP, IL-4 and IL-8 and eosinophilia were significantly higher in all patients with nasal polyps compared with controls. Inside, all patients with nasal polyposis showed lower levels of IL-6, IFN-gamma and IL-2 compared with controls. The atopic patients showed significant differences when compared with non-atopic patients for the higher concentrations of total IgE (698.80+/-322.24 vs. 279.63+/-234.11; P < 0.0001) and IL-8 (1437.2 pg/ml+/-1250.7 vs. 605.5 pg/ml+/-481.1; P < 0.015). These findings suggest that inflammation still remains the major factor in the etiology of nasal polyposis and show different levels of inflammatory mediators into atopic and non-atopic patients.

Association of stem cell factor expression in nasal polyp epithelial cells with aspirin sensitivity and asthma

Mast cells constitute a significant proportion of cells infiltrating nasal polyp tissue, and epithelial cells may release stem cell factor (SCF), a cytokine with chemotactic and survival activity for mast cells. We aimed to assess the expression of SCF in human nasal polyp epithelial cells (NPECs) as related to patients' clinical phenotypes. Nasal polyp tissues were obtained from 29 patients [including nine with aspirin (ASA)-hypersensitivity and 12 with bronchial asthma] undergoing polypectomy for nasal obstruction. Epithelial cells were obtained following 6-week culture of nasal polyps explants. The SCF released into the culture supernatant was assessed by enzyme-linked immunosorbent assay (ELISA) and total SCF mRNA in the polyp tissue was determined by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). For the whole group of patients, the number of polypectomies correlated with expression of SCF mRNA (r = 0.62; P < 0.005), SCF protein in the NPECs supernatants (r = 0.39; P < 0.05) and with density of mast cells in epithelial layer (r = 0.37; P < 0.05) and stromal layer (r = 0.5; P < 0.01) of nasal polyps. The SCF/beta-actin mRNA ratios were significantly higher in ASA-hypersensitive (AH) asthmatics (median 0.97, range: 0.8-1.5) when compared with ASA-tolerant (AT) patients (median 0.5, range: 0.1-0.7; P < 0.001). The SCF protein concentration in NPEC supernatants was also significantly higher in AH asthmatics (median 1.10 pg/microg DNA, range: 0.4-1.9) when compared with AT patients (median 0.1 pg/microg DNA, range: 0.02-1.2; P < 0.001). In the subpopulation of ASA-sensitive asthmatics the number of polypectomies correlated also with the density of mast cells and eosinophils in the polyp tissue.

Vascular endothelial growth factor in nasal polyps: a comparison of asthmatic and non-asthmatic patients

The cause of nasal polyps remains unknown, although there is a well-recognized clinical association between nasal polyposis and asthma. The characteristic histological features of nasal polyps include large quantities of extracellular fluid. Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis and vascular permeability. This study aimed to compare expression of VEGF in nasal polyps from patients with asthma and those with no apparent respiratory disease. Twenty-four asthmatic and 35 non-asthmatic patients were studied using immunohistochemistry for VEGF. VEGF expression was identified in endothelial, inflammatory and epithelial cells. There was significantly greater endothelial expression of VEGF in asthmatic patients (P < 0.05). Greater epithelial expression was observed in asthmatic patients but this did not reach statistical significance (P = 0.07). There was no difference in the density of inflammatory cells expressing VEGF. Differences between the two groups may reflect differences in disease severity or in the nature of the inflammatory process.

Intercellular adhesion molecule-1 expression in nasal polyps treated with corticosteroid

PURPOSE

The aim of this study was to compare intracellular adhesion molecule-1 (ICAM-1) expression in nasal polyp cases who were administered topical corticosteroid and in middle turbinates.

MATERIALS AND METHODS

Twenty-four patients with nasal polyps were included in the study group. These patients were treated with 100 microg budesonide in each nostril twice daily for 2 months before the surgery. Twenty-one nonatopic patients with concha bullosa were included in the control group. The specimens were taken from patients undergoing endoscopic surgery.

RESULTS

In polyps, significantly higher mean ICAM-1 intensity scores were found by comparison with the control turbinates.

CONCLUSIONS

Corticosteroid treatment in patients with nasal polyps does not diminish ICAM-1 to that of turbinate tissue. The initiating events in the formation of nasal polyps still occur in these patients despite treatment with the topical nasal steroid.

Eosinophilia in nasal polyposis: its objective quantification and clinical relevance

BACKGROUND

Eosinophilia within nasal polyps is often taken as a criterion for adjuvant medical treatment postoperatively such as topical steroids.

OBJECTIVE

This study was performed in order to validate a new technique for objective quantification of eosinophilia by using laser scanning cytometry (LSC), to compare these results with manual scoring and routine histopathology, and to correlate them with the history of allergy or recurrence.

METHODS

LSC was used for semi-automated analysis of single-cell preparations from representative ethmoidal polyps obtained during routine paranasal sinus surgery (n=41). This microscope-based instrument scans the cells after immobilization of cells on a glass slide and after triple staining of cytokeratin, eosinophilic granula, and DNA. The location of each cell is stored with the fluorescence data. Therefore, the morphology of every cell can be documented by re-staining with haemotoxylin and eosin and re-localization on the slide. Subsequently, slides were subjected to manual scoring. The remaining polyps were analysed by routine histopathology.

RESULTS

Data from LSC and manual scoring showed good correlation (r=0.81, P<0.001), whereas there were discrepancies with histopathology. Eosinophilia scored by LSC and histopathology was neither correlated with the history of allergy nor with recurrence as determined by Fisher's exact test independent of the definition of eosinophilia (> or =2%, > or =3%, or > or =5% of all cells).

CONCLUSION

Scoring eosinophilia by LSC in comparison with histopathology does not contribute to a more reliable basis for adjuvant medical therapy in nasal polyposis. Instead, functional parameters (cytokine production, apoptosis) may serve better.

Detection of Helicobacter pylori in nasal and maxillary sinus specimens from patients with chronic sinusitis

OBJECTIVES

In patients with chronic sinusitis, the colonization of nasal and maxillary sinus tissues by Helicobacter pylori (HP) was investigated using polymerase chain reaction, urease test (CLO test), culture, and immunohistochemical analysis.

STUDY DESIGN

A prospective clinical study.

METHODS

The subjects were 11 patients aged 20 to 72 years with chronic sinusitis who had undergone sinus surgery under local anesthesia. In 7 of 11 patients, the HP status of the stomach was also studied. Nasal and maxillary sinus tissues were studied using polymerase chain reaction, urease test, culture, and immunohistochemical analysis. Helicobacter pylori infection of nasal and maxillary sinus tissues was defined by at least two positive results of different tests.

RESULTS

Three (16%) of 19 nasal and maxillary sinus specimens from two patients were shown to be HP-positive (positive by polymerase chain reaction and immunohistochemical analysis and weakly positive by the CLO test). In one of these two patients, HP infection of the stomach was confirmed. In the other, a positive findings on immunohistochemical analysis suggested HP infection of the stomach. Immunoreactive structures were seen by immunohistochemical analysis in the nasal, maxillary sinus, and gastric specimens of these two patients but were partially degraded.

CONCLUSION

Helicobacter pylori may exist in the nasal and maxillary sinus tissue specimens of some patients with chronic sinusitis with gastric HP infection.

The new histologic classification of chronic rhinosinusitis

Two histologic patterns of disease are found in chronic rhinosinusitis. The first is dominated by eosinophilia and polypoid changes. Glandular hyperplasia and hypertrophy characterize the second. We present the evidence supporting the existence of these two patterns of disease and link these histologic patterns to the larger pathophysiologic processes that drive them. This histologic classification should be acknowledged both in the clinical setting and in laboratory research of chronic rhinosinusitis.