Eosinophil infiltration and activation in nasal polyposis

Eosinophilic and Non-eosinophilic Chronic Rhinosinusitis with Nasal Polyps and Their Clinical Comparison in Indian Population

Eosinophilic chronic rhinosinusitis with nasal polyps (eCRSwNP) and non-eosinophilic chronic rhinosinusitis with nasal polyps (neCRSwNP) are two distinct endotypes of chronic rhinosinusitis with nasal polyps (CRSwNP). The aim of the study was to find the prevalence of eCRSwNP and neCRSwNP, their clinical comparison and to establish predictive values for clinical and diagnostic factors to differentiate between eCRSwNP and neCRSwNP in Indian population with CRSwNP. This study was a prospective cohort, multi- institutional study. A total of 162 patients who were diagnosed with nasal polyps at different military hospitals in India during the period from 2011 to 2020 were selected for study. They were diagnosed in accordance with EPOS guidelines. They were randomly divided into two groups as eCRSwNP and neCRSwNP based on the response to oral corticosteroids for 2 weeks duration and the prevalence of eCRSwNP was established. Blood samples were collected and endoscopic sinus surgery was performed in all patients after atleast 2 months of last steroid dose. Preop CT scan scores, preop nasal endoscopy scores, preop blood eosinophil counts, preop tissue eosinophil counts were compared between the groups. Postop followup was done at 6 months by comparing CT scan scores and nasal endoscopy scores. Predictive values for clinical and diagnostic factors were established to diagnose eCRSwNP in Indian population. Out of a total 162 patients, 121 (74.6%) patients were classified into eCRSwNP and 41 (23.6%) into neCRSwNP out of a total of 162 patients with CRSwNP. CRSwNP was seen in the 4th decade. eCRSwNP was seen in the later part and neCRSwNP was seen in the early part. eCRSwNP was more common in males and neCRSwNP was more common in females. Smoking, asthma and aspirin intolerance were more commonly seen in eCRSwNP than neCRSwNP, p < 0.001, p = 0.020 respectively. Preop total CT scan score, preop bood absolute eosinophil count,preop blood eosinophil percentage, tissue eosinophil percentage, postop nasal endoscopy score, postop CT scan score were stastically significant in eCRSwNP, p < 0.001 except preop total nasal endoscopic score. Tissue absolute eosinophil count had best predictive accuracy plotted with receiver operating characteristic (ROC) curve analysis, area under curve (AUC) 0.923(95% CI, 0.876-0.970). The cutoff points determined to diagnose eCRSwNP were ≥ 15 for preop total CT scan score,  ≥ 378 × 106/L for preop absolute blood eosinophil count,  ≥ 6.5% for preop blood eosinophil percentage,  ≥ 14% for tissue eosinophil percentage,  ≥ 16 for absolute tissue eosinophil count, ≥ 1 for 6 months postop total nasal endoscopy score,  ≥ 2 for 6 months postop total CT scan score. eCRSwNP and neCRSwNP are two distinct endotypes of nasal polyps present in Indian population with CRSwNP. Two thirds of the patients with nasal polyps were eCRSwNP and the prevalence in Indian population is more than the East Asian population but less than the Western population. There is a high chance of recurrence and treatment failures for eCRSwNP than neCRSwNP. The cutoff points for various non invasive diagnostic predictors are useful to diagnose the patients with eCRSwNP during the outpatient visits and hence plan for better treatment strategies.

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.

25-Hydroxyl Vitamin D Deficiency in Nasal Polyposis

Introduction  Vitamin D is known to have immunomodulatory functions and has action on chronic inflammatory processes, such as nasal polyposis.

Objective  The present study assessed the levels of 25-hydroxy vitamin D and high-sensitivity C-reactive protein (hs-CRP) in patients with nasal polyposis, as compared with healthy control subjects, and identified their association with disease severity in nasal polyposis. It further assessed the levels of 25-hydroxyl vitamin D and hs-CRP in patients with nasal polyposis and atopy and compared it with patients with nasal polyposis without atopy.

Methods  This was a cross-sectional study involving 2 groups: 80 patients with nasal polyposis and 80 healthy subjects. In patients with nasal polyposis, the disease severity is assessed by the sino-nasal outcome test (SNOT20) and by the Lund & Mackay staging system. Levels of 25-hydroxy vitamin D and hs-CRP were measured by enzyme-linked immunosorbent assay (ELISA).

Result  The mean 25-hydroxyl vitamin D levels (ng/ml) was 12.01 ± 7.29 for cases and 22.87 ± 14.95 for controls, with p  < 0.0001. The mean hs-CRP levels (mg/L) was 5.99 ± 2.74 in cases and 2.41 ± 1.95 in controls, with p  < 0.0001. The severity of polyposis correlated negatively with serum levels of 25-hydroxy vitamin D and positively with hs-CRP.

Conclusion  The study has thus shown significant correlation between vitamin D deficiency and inflammation in patients with nasal polyps.

Histopathological Features of Chronic Rhinosinusitis with Nasal Allergic Polyps

Chronic rhinosinusitis with nasal polyps of allergic etiology is one of the most common pathology in the ENT sphere that affect a significant percentage of population. The paper aims to establish the involvement of the allergic component in the genesis of nasal polyposis. The study included 150 nasal polyps from patients hospitalized and operated in the ENT Department of Craiova's Clinical Emergency County Hospital. The biological material was fixed in 10% buffered formalin, processed by classical paraffin embedding technique followed by hematoxylin-eosin staining and it was interpreted in the Pathology Department of the same hospital. We evaluated a number of histopathological parameters that were given severity scores. The most common changes at epithelial level were: basal layer hyperplasia observed in 87 cases (58%), goblet cell hyperplasia in 121 cases (80.66%), basal membrane thickening with values between 10-42μm corresponding to a number of 118 cases (78.66%). The most important stromal changes were edema in 88% and infiltration with eosinophils 100%, indicating the allergic nature of this disease.

Adhesion molecules as predictors of nasal polyposis recurrence

BACKGROUND

Nasal polyposis is a chronic inflammation of nasal and paranasal sinuses in the pathogenesis of which adhesion molecules may have a significant role. This study investigates the possible role of certain adhesion molecules, mucins, and oncogenes in nasal polyposis recurrence.

METHODS

A sample study of 21 individuals (17 men and 4 women) aged 47.44 ± 15.10 years with nasal polyposis who had undergone nasal surgery twice was used. Twenty-one individuals aged 46.9 ± 12.8 years suffering from nasal polyposis who had undergone surgery only once in the same period were used as a control sample.

RESULTS

Statistically significant differences between the two groups were observed regarding epithelial membrane antigen (EMA/mucin 1) of stromal cells (p < 0.001) and CD86 stromal expression (p = 0.009). No patient of the control group exhibited high (++) CD86 stromal expression, whereas six patients of the resurgery group did so. When EMA and CD86 were included in a logistic regression model, stromal EMA was found to be positively related to recurrence.

CONCLUSION

Adhesion molecules may relate to nasal polyp prognosis and recurrence rates.

Intercellular adhesion molecule-1 expression in activated eosinophils is associated with mucosal remodeling in nasal polyps

Nasal polyposis (NP) is characterized by chronic mucosal inflammation with infiltrating eosinophils. Eosinophil-mediated tissue remodeling may be involved in NP pathogenesis; therefore, improved understanding of tissue remodeling may result the identification of novel pathways and therapeutic strategies. The present study aimed to investigate the pathological changes occurring during tissue remodeling in NP, in order to assess the role of intercellular adhesion molecule-1 (ICAM-1) in localized tissue remodeling and the potential association between ICAM-1 expression and markers of eosinophil activation. A total of 28 eligible patients and 10 healthy controls participated in the current study. Nasal mucosal tissues of these subjects were retrospectively evaluated for mucosal remodeling using histopathological staining. ICAM-1 and eosinophil cationic protein (ECP) expression levels were determined by immunohistochemical analysis. Compared with the healthy controls, all the specimens from NP patients presented substantial epithelial damage, skewed cellular distribution with a reduced density of goblet cells, an increased density of subepithelial gland and increased subepithelial collagen deposition. In addition, the NP specimens exhibited significantly higher eosinophil infiltration and ICAM-1 expression compared with the controls. Positive correlations were observed between ICAM-1 and ECP expression levels (P=0.010), as well as between extracellular collagen deposition and ICAM-1 (P=0.010) and ECP (P=0.012) expression levels in the NP specimens, but not in the control specimens. Morphological evidence demonstrated eosinophil-mediated tissue remodeling in NP tissues. ICAM-1 expression in activated eosinophils was associated with NP remodeling, indicating the possibility that ICAM-1 may regulate NP remodeling.

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.

Interleukin-4 and interleukin-13 compromise the sinonasal epithelial barrier and perturb intercellular junction protein expression

BACKGROUND

Altered expression of epithelial intercellular junction proteins has been observed in sinonasal biopsies from nasal polyps and epithelial layers cultured from nasal polyp patients. These alterations comprise a "leaky" epithelial barrier phenotype. We hypothesize that T helper 2 (Th2) cytokines interleukin (IL)-4 and IL-13 modulate epithelial junction proteins, thereby contributing to the leaky epithelial barrier.

METHODS

Differentiated primary sinonasal epithelial layers cultured at the air-liquid interface were exposed to IL-4, IL-13, and controls for 24 hours at 37°C. Epithelial resistance measurements were taken every 4 hours during cytokine exposure. Western blot and immunofluorescence staining/confocal microscopy were used to assess changes in a panel of tight and adherens junction proteins. Western blot densitometry was quantified with image analysis.

RESULTS

IL-4 and IL-13 exposure resulted in a mean decrease in transepithelial resistance at 24 hours to 51.6% (n = 6) and 68.6% (n = 8) of baseline, respectively. Tight junction protein junctional adhesion molecule-A (JAM-A) expression decreased 42.2% with IL-4 exposure (n = 9) and 37.5% with IL-13 exposure (n = 9). Adherens junction protein E-cadherin expression decreased 35.3% with IL-4 exposure (n = 9) and 32.9% with IL-13 exposure (n = 9). Tight junction protein claudin-2 showed more variability but had a trend toward higher expression with Th2 cytokine exposure. There were no appreciable changes in claudin-1, occludin, or zonula occludens-1 (ZO-1) with IL-4 or IL-13 exposure.

CONCLUSION

Sinonasal epithelial exposure to Th2 cytokines IL-4 and IL-13 results in alterations in intercellular junction proteins, reflecting increased epithelial permeability. Such changes may explain some of the phenotypic manifestations of Th2-mediated sinonasal disease, such as edema, nasal discharge, and environmental reactivity.

Sinonasal epithelial wound resealing in an in vitro model: inhibition of wound closure with IL-4 exposure

BACKGROUND

Prolonged healing and persistent inflammation following surgery for rhinosinusitis impacts patient satisfaction and healthcare resources. Cytokines interleukin (IL)-4, IL-5, and IL-13 are important mediators in T-helper 2 (Th2) inflammatory rhinosinusitis. Decreased wound healing has been demonstrated with Th2 cytokine exposure, but this has not been extensively studied in sinonasal epithelium. We hypothesized that in vitro exposure of primary sinonasal epithelial cell cultures to Th2 inflammatory cytokine IL-4 and IL-13 would impair wound resealing and decrease expression of annexin A2 at the wound edge.

METHODS

Following 24-hour exposure to IL-4, IL-5, or IL-13 vs controls, sterile linear mechanical wounds were created in primary sinonasal epithelial cultures (n = 12 wounds per condition). Wounds were followed for 36 hours or until complete closure, and residual wound areas were calculated by image analysis. Group differences in annexin A2 were assessed by immunofluorescence labeling, confocal microscopy, and Western blots.

RESULTS

Significant wound closure differences were identified across cytokine exposure groups (p < 0.001). Mean percentage wound closure at the completion of the 36-hour time course was 98.41% ± 3.43% for control wounds vs 85.02% ± 18.46% for IL-4 exposed wounds. IL-13 did not significantly impair sinonasal epithelial wound resealing in vitro. Annexin A2 protein levels were decreased in IL-4 treated wounds when compared to control wounds (p < 0.01).

CONCLUSION

Th2 cytokine IL-4 decreases sinonasal epithelial wound closure in vitro. Annexin A2 is also diminished with IL-4 exposure. This supports the hypothesis that IL-4 exposure impairs sinonasal epithelial wound healing and may contribute to prolonged healing in Th2 inflammatory rhinosinusitis.

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.

Markers of antigen presentation and activation on eosinophils and T cells in the esophageal tissue of patients with eosinophilic esophagitis

OBJECTIVES

Evidence suggests eosinophils may be acting as antigen-presenting cells (APCs) by presenting antigen to T cells. We investigated the surface proteins of eosinophils and T cells in the esophageal biopsies of patients with eosinophilic esophagitis (EoE), patients with gastroesophageal reflux disease (GERD), and healthy controls (HCs).

METHODS

: Subjects were categorized as EoE, GERD, or HC. In esophageal tissue, EG2+ eosinophils were stained for the APC markers, CD40 or CD80, via immunohistochemistry. CD3+ T cells were stained for costimulatory markers, CD40L or CD28, and for activation markers, CD69 or CD134, via immunofluorescence or immunohistochemistry.

RESULTS

Eosinophils stained with CD40 and CD80. The number of EG2+CD40+ cells was increased in EoE (mean 19.1±14.8 cells/high-power field [HPF], n=11), compared with GERD (mean 0.13±0.19 cells/HPF, n=5, P<0.01) and HC (mean 0.3±0.7 cells/HPF, n=5, P<0.01). There was an elevation in EG2+CD80+ cells in EoE (mean 18.1±16.2 cells/HPF, n=10), GERD (mean 1.7±2.8 cells/HPF, n=6, P<0.01), or HC (mean 0.8±1.3 cells/HPF, n=6, P<0.01). CD3+ T cells stained with CD40L (not quantified). CD3+ T cells stained with CD28 at elevated levels in EoE (mean 14±8.7 cells/HPF, n=9) versus GERD (mean 3.3±1.2 cells/HPF, n=6, P<0.05) or HC (mean 3.0±3.2 cells/HPF, n=7, P<0.01). The number of CD3+CD69+ cells was highest in EoE (mean 14.8±7.5 cells/HPF, n=6) versus GERD (mean 0.8±0.9 cells/HPF, n=6, P<0.001) or HC (mean 2.7±2.5 cells/HPF, n=6, P<0.001).

CONCLUSIONS

We show that esophageal eosinophils express CD40 and CD80, and T cells with CD40L, CD28, and CD69. The number of double-stained cells was higher in EoE in comparison to control groups. These data support the hypothesis that eosinophils in EoE may act as APCs, activating T cells.

Effect of long-term, low-dose clarithromycin on T helper 2 cytokines, eosinophilic cationic protein and the 'regulated on activation, normal T cell expressed and secreted' chemokine in the nasal secretions of patients with nasal polyposis

BACKGROUND

Little is known about the effects of macrolides on the cytokines and chemokines that modulate the function of eosinophils in nasal polyposis.

METHODS

Twenty-two non-allergic and 18 allergic patients with nasal polyps were administered clarithromycin 500 mg/day (single oral dose) for eight weeks. We measured the nasal secretion levels of the T helper 2 (also known as Th2) cytokines interleukin 4, 5 and 6, the 'regulated on activation, normal T cell expressed and secreted' (also known as RANTES) chemokine, and the eosinophilic cationic protein, before and after treatment.

RESULTS

After clarithromycin treatment, we found reduced levels of the 'regulated on activation, normal T cell expressed and secreted' chemokine in samples from both non-allergic and allergic patients (p < 0.05). Clarithromycin treatment decreased the levels of eosinophilic cationic protein only in non-allergic patients (p < 0.05), and decreased the level of interleukin 6 only in allergic patients (p < 0.05). Decreased levels of the 'regulated on activation, normal T cell expressed and secreted' chemokine were associated with a reduction in polyp size both in non-allergic and allergic patients.

CONCLUSION

Clarithromycin has a strong anti-inflammatory effect in nasal polyposis, but has different immunomodulatory effects in allergic and non-allergic nasal polyposis patients.

Nasal polyposis in patients with asthma and allergic rhinitis

OBJECTIVE

This study aimed to determine the prevalence of nasal polyps in patients with allergic rhinitis and with asthma, and also to assess the impact of this condition on these disorders.

STUDY DESIGN

Cross-sectional study.

METHODS

The presence of nasal polyps was assessed by rhinoscopy and endoscopic examination.

RESULTS

Nasal polyps were detected in 60 out of 250 patients (24 per cent) with documented asthma or allergic rhinitis. There was a statistically significant correlation between asthma severity and nasal polyposis prevalence (p = 0.007), but not between allergic rhinitis severity and nasal polyposis prevalence (p = 0.081). The prevalence of nasal polyps increased significantly with increasing patient age and rhinitis or asthma duration.

CONCLUSION

The prevalence of nasal polyps in patients with allergic rhinitis or asthma was higher than previously reported. Given this high prevalence of nasal polyposis, nasal examination and concomitant treatment of this disorder are recommended.

Serum interleukin-16 levels in patients with nasal polyposis

OBJECTIVE/HYPOTHESIS

Several inflammatory and allergic disorders have been reported to correlate with interleukin-16 (IL-16). IL-16 is a highly potent chemotactic and chemoattractant molecule for eosinophils. Nasal polyposis (NP) has an inflammatory basis, and eosinophilia is a common finding in polyp tissue. In this study, we aimed to determine serum IL-16 levels in NP patients.

STUDY DESIGN

Prospective controlled study in a tertiary academic hospital.

METHODS

Peripheral blood samples were obtained and used for serologic studies with enzyme-linked immunosorbent assay kits to determine IL-16 levels.

RESULTS

The study and the control groups consisted of 17 and 10 patients, respectively. Mean serum IL-16 levels were significantly higher in the study group when compared to the control group (447.9 pg/mL vs. 260.2 pg/mL) (P < .001).

CONCLUSIONS

Serum IL-16 levels are significantly elevated in NP patients. This finding may represent identification of a valuable serum biomarker and potential therapeutic target in NP patients.

Plasma RANTES and eotaxin levels are correlated with the severity of chronic rhinosinusitis

Eosinophilia occurs in up to 75-90% of nasal polyps in Caucasians. The chemokines eotaxin and RANTES increase eosinophil recruitment, activation, and survival, and these chemokines are significantly expressed in nasal polyps. We hypothesized that eotaxin and RANTES plasma levels might be correlated with disease severity. We compared the eotaxin and RANTES plasma levels in 20 Taiwanese patients with chronic rhinosinusitis and nasal polyps and 20 Taiwanese healthy controls. Eotaxin and RANTES plasma levels were measured by ELISA and disease severity was scored by CT scans. Compared to controls, patients with nasal polyps had significantly elevated plasma levels of eotaxin and RANTES and increased peripheral blood eosinophils (p < 0.001). Eotaxin plasma levels were significantly correlated with disease severity in patients with chronic rhinosinusitis to a greater extent than were RANTES levels. RANTES and eotaxin levels were also positively correlated with the percentages of peripheral blood eosinophils. Eotaxin plasma levels are significantly correlated with disease severity in Taiwanese patients with nasal polyposis to a greater degree than are RANTES levels. Additional studies are needed to assess whether eotaxin plasma levels can be used to monitor disease progression and attenuation.

Correlation between cytokine levels in nasal fluid and scored clinical parameters in patients with nasal polyposis

The aim of this study was to compare the cytokine levels in nasal fluid in subjects with nasal polyposis (NP) and co-morbid asthma and NP patients without asthma and to correlate these levels with clinical parameters of severity of disease. Forty NP patients (20 asthmatic and 20 nonasthmatic) were enrolled. Nasal secretion samples were collected from nasal cavities of all 40 subjects. The levels of Th1 cytokines IL-2, IL-12 and IFN-γ, Th2 cytokines IL-4, IL-5, IL-6, and IL-10, chemokine IL-8, and proinflammatory cytokines IL-1β, TNF-α and TNF-β were measured using flow cytometric method. Each of the 40 patients was staged clinically according to global nasal symptom score, endoscopic score, and Lund-Mackay computed tomography (CT) score. The concentrations of Th2 cytokines IL-5, IL-6 and IL-10 were significantly higher (P < 0.01, P < 0.01, P < 0.05) in patients with NP and asthma compared with NP patients without asthma. Positive correlations were observed between concentration of IL-2 in nasal secretions and global nasal symptom score, endoscopic score, and Lund-Mackay score only in NP patients without asthma. We also found positive correlation between CT score and the levels of IL-8, IL-4, and IL-1β in nonasthmatic patients. Finally, our results showed a positive correlation between IL-5 levels in nasal fluid and endoscopic score only in asthmatic patients. NP in asthmatic patients have different immunological patterns compared to those without asthma. We also concluded that concentrations of cytokines measured in nasal fluid were not sensitive enough to determine the severity of disease.

Eosinophilic Inflammation in Allergic Rhinitis and Nasal Polyposis

On histopathological examination, nasal polyps and nasal mucosa in allergic rhinitis show different forms of pseudostratified respiratory epithelium, whereas the dominant characteristic of lamina propria is an eosinophilic infiltration. The aim of this study was to compare interleukin (IL)-5 and eosinophilic cationic protein (ECP) levels in the nasal fluid of 42 patients: 12 with allergic rhinitis and nasal septal deviation, 17 non-atopic patients with nasal polyposis, and 13 atopic nasal polyp patients were enrolled in this cross-sectional study. Nasal secretion samples were collected a few days before surgery. The levels of IL-5 were measured using flow cytometry and the ECP using a commercial ELISA kit. In addition, we counted eosinophils in hematoxylin-and-eosin-stained sections of all nasal polyp and all nasal mucosa samples taken from the inferior nasal turbinates during septoplasty. A significantly higher concentration of IL-5 was found in the nasal fluid of atopic patients with nasal polyposis than in non-atopic nasal polyp patients (p=0.025) and patients with allergic rhinitis (p=0.05). ECP was higher in atopic nasal polyp patients than in patients with allergic rhinitis (p<0.0001) and than in non-atopic nasal polyp patients (p<0.0001). Polyp eosinophils were higher in atopic' than in non-atopic patients (p<0.0001) and higher than in the mucosa of patients with allergic rhinitis (p<0.0001). These however had significantly more mucosal eosinophils than was found in the polyps of non-atopic patients' (p=0.025). ECP levels in nasal fluid and eosinophil counts in tissue specimens correlated well in all three groups of patients. Our study has shown that atopic nasal polyp patients have a higher level of eosinophilic inflammation than non-atopic patients with nasal polyps and patients with allergic rhinitis.

Expression of galectin-9 by IFN-γ stimulated human nasal polyp fibroblasts through MAPK, PI3K, and JAK/STAT signaling pathways

Galectin-9 exhibited potent and selective eosinophil chemoattractant activity and attracted eosinophils in vitro and in vivo. Nasal polyposis is a chronic inflammatory disease of the upper airway characterized by the marked presence of inflammatory cells, particularly eosinophils. Thus, galectin-9 may be implicated in the pathogenesis of nasal polyposis. The study was designed to investigate whether interferon-gamma (IFN-γ) can induce the augmentation of galectin-9 expression and induce the expression of galectin-9 in nasal polyps. We examined the correlation between galectin-9 expression and eosinophil infiltration in nasal polyps. In addition, we identified the signaling pathways involved in the elevation of galectin-9 expression in response to IFN-γ. Our data demonstrate that the involvement of mitogen-activated protein kinases (MAPKs), phosphatidylinositol 3 phosphate kinase (PI3K), and Janus kinase/signal transducer and activator of transcription (JAK/STAT) may play important roles in the selective recruitment of eosinophils in nasal polyp tissues through the production of galectin-9. These findings suggest that galectin-9 expression is associated with eosinophil infiltration in polyps of patients with nasal polyposis.

Correlation between cytokine levels in nasal fluid and eosinophil counts in nasal polyp tissue in asthmatic and non-asthmatic patients

BACKGROUND/AIMS

Concentrations of mediators in nasal secretions could reflect the inflammatory status of the nasal mucosa and evolution of sinus disease. So, the aim of our study was to evaluate local immune reaction by measuring crucial Th1, Th2 and inflammatory cytokines in nasal fluid samples of patients with nasal polyps (NP), and to correlate them to clinical, radiological findings and to the degree of eosinophil infiltration of polyp tissue. Therefore, in our study we compared the cytokine levels in nasal fluid of asthmatic and non-asthmatic patients with nasal polyposis, the eosinophil counts in NP tissues of these patients, and we correlated cytokine levels with eosinophil counts in NP tissue specimens.

MATERIAL AND METHODS

Thirty patients with nasal polyposis (NP) (15 asthmatic and 15 non-asthmatic) were included in this prospective study. Nasal secretion samples were collected from nasal cavities of all subjects. The levels of 11 cytokines (TNF-α, TNF-β, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, and IFN-γ) were measured using commercial flow cytometric kit. Eosinophils were counted in haematoxylin-and-eosin-stained NP sections.

RESULTS

The concentrations of Th2 cytokines IL-5, IL-6, IL-10, and Th1 cytokine IFN-γ were significantly higher in patients with NP and asthma compared with non-asthmatic subjects. A positive correlation was found between IL-6 and TNF-α levels in nasal fluid and eosinophil counts in polyp tissue in non-asthmatic subjects. In asthmatic NP patients, we found positive correlation between level of IL-6 and eosinophil counts and negative correlation between IFN-γ level and number of eosinophils in NP tissue specimens.

CONCLUSION

Our results showed that these patients with similar clinical findings had significantly different mediator profiles in their nasal secretions, implying clear differences in pathogenesis of their NP.

Increased expression and role of thymic stromal lymphopoietin in nasal polyposis

Purpose

Nasal polyposis is a chronic inflammatory disease of the upper airways often associated with asthma and characterized by markedly increased numbers of eosinophils, Th2 type lymphocytes, fibroblasts, goblet cells and mast cells. Previous studies have shown elevated levels of thymic stromal lymphopoietin (TSLP) in atopic diseases like asthma, atopic dermatitis and mainly in animal models of allergic rhinitis (AR). Here, we investigated the expression of TSLP in nasal polyps from atopics and non-atopics in comparison with the nasal mucosa and its potential role in nasal polyposis.

Methods

Messenger RNA expression for TSLP, thymus and activation-regulated chemokine (TARC) and macrophage derived chemokine (MDC) in nasal polyps and nasal mucosa of atopics and non-atopics was analyzed by real time PCR. Immunoreactivity for TSLP in nasal polyps and in the nasal mucosa of patients with AR and non-allergic rhinitis (NAR) was analyzed by immunohistochemistry. Eosinophil counts was analyzed by Wright-Giemsa staining and nasal polyp tissue IgE, by ELISA.

Results

Messenger RNA expression for TSLP,TARC and MDC was markedly higher in nasal polyps as compared to the allergic nasal mucosa. Immunoreactivity for TSLP was detected in epithelial cells, endothelial cells, fibroblasts and inflammatory cells of the nasal mucosa and nasal polyps. The number of TSLP+ cells was significantly greater in the nasal mucosa of AR than NAR patients. The number of TSLP+ cells in nasal polyps from atopics was significantly greater than that of non-atopics and that in the allergic nasal mucosa. The number of TSLP+ cells correlated well with the number of eosinophils and the levels of IgE in nasal polyps.

Conclusions

The high expression of TSLP in nasal polyps and its strong correlation to eosinophils and IgE suggest a potential role for TSLP in the pathogenesis of nasal polyps by regulating the Th2 type and eosinophilic inflammation.

Increased HLA-DR expression on tissue eosinophils in eosinophilic esophagitis

OBJECTIVE

The aim of the study was to investigate whether eosinophils have increased human leukocyte antigen (HLA)-DR expression in subjects with eosinophilic esophagitis (EoE) compared with controls.

PATIENTS AND METHODS

Patients who were undergoing an upper endoscopy with biopsies for suspected gastroesophageal reflux disease (GERD) or EoE at Lucile Packard Children's Hospital were enrolled. In total, the blood and tissue samples of 10 healthy controls (HC), 11 subjects with GERD, and 10 with EoE were studied. Multiple tissue staining to identify eosinophils (via eosinophil cationic protein-clone EG2) and major histocompatibility complex class II cell surface receptors (via HLA-DR) was performed via immunohistochemistry. The peripheral blood was analyzed using flow cytometry to detect eosinophil HLA-DR expression among these subjects.

RESULTS

In the tissue, a greater proportion of eosinophils expressed HLA-DR among the subjects with EoE (mean 0.83 +/- 0.14, n = 9) relative to those with GERD (mean 0.18 +/- 0.19, n = 8, P < 0.01) and HC (mean 0.18 +/- 0.13, n = 6, P < 0.01). In total, 6 participants (4 HC subjects and 2 subjects with GERD) did not have any eosinophils identified on tissue staining and were unable to be included in the present statistical analysis. In the blood, there was no statistically significant difference in eosinophil HLA-DR expression among HC subjects (mean 415 +/- 217, n = 6), subjects with GERD (mean 507 +/- 429, n = 2), and those with EoE (mean 334 +/- 181, n = 6).

CONCLUSIONS

These data demonstrate that the eosinophils from the esophagus of subjects with EoE have increased HLA-DR expression within this tissue.

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.