The presence of eosinophil aggregates correlates with increased postoperative prednisone requirement

Platycodon D protects human nasal epithelial cells from pyroptosis through the Nrf2/HO-1/ROS signaling cascade in chronic rhinosinusitis

BACKGROUND

Pyroptosis has been demonstrated being closely associated with the inflammatory progression in chronic rhinosinusitis (CRS). However, platycodon D (PLD) has emerged as a key anti-inflammatory mediator in the inflammatory progression of various respiratory diseases. This study aims at investigating whether PLD could reduce inflammatory progression of CRS by inhibiting pyroptosis.

METHODS

Nasal mucosal tissues from patients with CRS and the control group (simple nasal septal deviation) were analyzed for morphological difference using hematoxylin & eosin staining and for the expression of pyroptosis-related makers by immunofluorescence (IF). Human nasal epithelial cells (HNEpCs) were cultured and co-stimulated with lipopolysaccharide (LPS)/adenosine triphosphate (ATP) to construct an in vitro cellular model simulating CRS. After pretreatment with PLD, EthD-I staining, TUNEL staining, transmission electron microscopy (TEM), and GSDMD-NT detection were performed to evaluate pyroptosis markers. The NLRP3 inflammasome was detected by IF and western blotting (WB). Reactive oxygen species (ROS) were detected by H2DCFDA staining, and mitochondrial membrane potential was evaluated by JC-1 staining. Mitochondrial morphology and structure were observed using TEM. The Nrf2/HO-1 antioxidant signaling pathway was detected using WB.

RESULTS

The nasal mucosa structure of patients with CRS exhibited significant damage, with a marked increase in the expression of pyroptosis-related proteins compared with the control group. LPS/ATP co-stimulation resulted in an increased expression of IL-18 and IL-1β in HNEpCs, causing significant damage to nuclear and cell membranes, GSDMD-NT accumulation around the cell membrane, and intracellular NLRP3 inflammasome activation. Furthermore, it led to increased ROS expression, significantly decreased mitochondrial membrane potential, and damaged mitochondrial structure. However, pretreatment with PLD significantly reversed the aforementioned trends and activated the Nrf2/HO-1 antioxidant signaling pathway.

CONCLUSIONS

The results of this study confirm that NLRP3-mediated pyroptosis plays a crucial role in the pathological process of nasal mucosal impairment in patients with CRS. PLD inhibits NLRP3-mediated pyroptosis, preventing inflammatory damage in HNEpCs of patients with CRS by activating the Nrf2/HO-1 antioxidant signaling pathway, which in turn reduces ROS production and ameliorates mitochondrial damage.

Polyps' Extension and Recurrence in Different Endotypes of Chronic Rhinosinusitis: A Series of 449 Consecutive Patients

Different inflammatory endotypes reflect the heterogeneity of chronic rhinosinusitis with nasal polyps' (CRSwNPs) clinical presentation. This retrospective study aimed to analyze the distribution of polyps in nasal cavities and paranasal sinuses to establish a possible association between CRSwNP endotypes, prognosis, and polyps' extension. This study included 449 adult patients who underwent endoscopic sinus surgery for CRSwNPs between 2009 and 2022. Patients were categorized based on the number of paranasal sinuses involved by polyps. Statistical analyses, including Cox regression, were performed to identify associations between demographic, clinical, and histopathological factors and disease recurrence. CRSwNP patients were stratified into four groups based on the extent of polyp involvement. Asthma and acetylsalicylic acid (ASA) sensitivity were associated with more sinuses involved (p-values = 0.0003 and 0.0037, respectively). Blood eosinophil counts increased with the number of sinuses affected (p-value < 0.0001). The distribution of eosinophilic and non-eosinophilic histotypes varied significantly among these groups (p-value < 0.0001). The risk of CRSwNP recurrence was higher in patients with asthma, higher basophil percentages, and eosinophilic histotype (p-value 0.0104, 0.0001, 0.0118, and 0.0104, respectively). This study suggests a positive association between the number of paranasal sinuses involved by polyps and the severity of CRSwNPs, particularly in patients with eosinophilic histotype, asthma, and ASA sensitivity.

Histological Characteristics of Chronic Allergic Rhinitis Versus Non-allergy: Is There a Difference in the Remodeling?

Demonstrate the histological remodeling changes in the turbinates, identify the frequency of the two forms of rhinitis in the samples studied and determine the remodeling differences found in the two variants. Patients attended an otolaryngology service at the Social Security Hospital of city Sangolqui-Ecuador from February 2016 to June 2017. The allergic variant was determined when eosinophils were found by higher magnification field and non-allergic when they were not found in the submucosal segment. Epithelial, inflammatory, and stromal markers were analyzed. One hundred twenty histopathological samples were analyzed, 75% presented allergic rhinitis, the age averaged 36.2 years. When we compared between the allergic and non-allergic variants: epithelial and stromal markers we had significant differences, as well as between each of its components; except fibrosis. In relation to the inflammatory pattern, there were significant differences between the number of mast cells and stromal markers with eosinophils > 10 by field. The allergic type corresponded to 75% of patients with persistent severe rhinitis who underwent turbinectomy. Regarding remodeling, there was a statistically significant difference in favor of the allergic variant. Eosinophilia greater than 10 was directly related to mastocytosis and subepithelial edema.

Association of Comorbid Asthma and the Efficacy of Bioabsorbable Steroid-eluting Sinus Stents Implanted After Endoscopic Sinus Surgery in Patients with Chronic Rhinosinusitis with Nasal Polyps

OBJECTIVE

To identify factors affecting the efficacy of steroid-eluting sinus stents implanted after endoscopic sinus surgery (ESS) in patients with chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

We performed a post-hoc analysis of a randomized self-controlled clinical trial on post-operative implantation of bioabsorbable steroid-eluting stents in patients with CRSwNP. Univariate logistic regression analysis was conducted to identify which of the following factors affect the response to post-operative stent implantation: sex, serum eosinophil levels, history of prior surgery, endoscopic scores, and comorbid conditions (asthma and allergic rhinitis). The primary outcome was the rate of post-operative intervention on day 30, and the secondary outcome was the rate of polypoid tissue formation (grades 2-3) on days 14, 30, and 90.

RESULTS

A total of 151 patients with CRSwNP were included in the post-hoc analysis. Asthma was identified as the only risk factor for a poor response to steroid-eluting sinus stents on post-operative day 30, with an odds ratio of 23.71 (95% CI, 2.81, 200.16; P=0.004) for the need for post-operative intervention and 19 (95% CI, 2.20, 164.16; P=0.003) for moderate-to-severe polypoid tissue formation. In addition, the asthmatic group showed higher rates of post-operative intervention and polypoid tissue formation than the non-asthmatic group on post-operative day 30. Blood eosinophil levels were not identified as a risk factor for poor outcomes after stent implantation.

CONCLUSION

Comorbid asthma, but not blood eosinophil level, impairs the efficacy of steroid-eluting sinus stents in the short term after ESS in patients with CRSwNP.

The role of intranasal corticosteroids in chronic rhinosinusitis with nasal polyposis treated with dupilumab

PURPOSE

Dupilumab represents an innovative and effective therapy for refractory/recurrent severe chronic rhinosinusitis with nasal polyps (CRSwNP). Intranasal corticosteroids should be used during treatment with biological agents. However, adherence to nasal therapy may not be complete. The aim of this study was to evaluate the role of intranasal corticosteroids in patients with CRSwNP who underwent treatment with dupilumab.

MATERIALS AND METHODS

Fifty-two patients treated with dupilumab for CRSwNP were enrolled. Clinical parameters (age, sex, comorbidities, blood eosinophils, Nasal Polyp Score - NPS, Visual Analogue Scale - VAS - for smell loss, Asthma Control Test - ACT), quality of life (Sino Nasal Outcome Test 22 - SNOT-22 questionnaire), nasal cytology, and adherence to regular administration of intranasal corticosteroids were recorded before treatment (T0), and after 3 (T1), 6 (T2), and 12 months (T3).

RESULTS

NPS, VAS for smell, ACT and SNOT-22 total score and subscores improved during treatment (p < 0.05). Blood eosinophils reached a peak at T1-T2 and then decreased toward baseline at T3. Adherence to regular treatment with intranasal steroids was 61.5 %. No statistically significant differences in all the clinical outcomes were observed between patients who regularly used intranasal steroids and other subjects (p > 0.05). Nasal cytology showed a decrease of eosinophils and an increase of neutrophils during treatment.

CONCLUSIONS

Dupilumab is still effective in patients who are using topical nasal steroids with variable adherence (real world settings).

Endotyping Difficult-to-Treat Chronic Rhinosinusitis with Nasal Polyps by Structured Histopathology

INTRODUCTION

This study aimed to identify the histopathologic characteristics associated with difficult-to-treat chronic rhinosinusitis with nasal polyps (CRSwNPs), enabling physicians to predict the risk of poor outcome after endoscopic sinus surgery (ESS).

METHODS

A prospective cohort study performed at the First Affiliated Hospital of Sun Yat-sen University between January 2015 and December 2018 with CRSwNP patients who underwent ESS. Polyp specimens were collected during surgery and were subjected to structured histopathological evaluation. Difficult-to-treat CRSwNPs were determined at 12-15 months post-operation according to the European Position Paper. Multiple logistic regression model was used to assess the association between histopathological parameters and the difficult-to-treat CRSwNP.

RESULTS

Among 174 subjects included in the analysis, 49 (28.2%) were classified with difficult-to-treat CRSwNP, which had higher numbers of total inflammatory cells, tissue eosinophils, and percentages of eosinophil aggregates and Charcot-Leyden crystals (CLC) formation but a lower number of interstitial glands than the nondifficult-to-treat CRSwNP. Inflammatory cell infiltration (adjusted OR: 1.017), tissue eosinophilia (adjusted OR: 1.005), eosinophil aggregation (adjusted OR: 3.536), and CLC formation (adjusted OR: 6.972) were independently associated with the difficult-to-treat outcome. Furthermore, patients with tissue eosinophil aggregation and CLC formation had an increasingly higher likelihood of uncontrolled disease versus those with tissue eosinophilia.

CONCLUSION

The difficult-to-treat CRSwNP appears to be characterized by increased total inflammatory infiltrates, tissue eosinophilia, eosinophil aggregation, and CLC formation in structured histopathology.

Molecular and Clinical Predictors of Quality of Life in Chronic Rhinosinusitis with Nasal Polyps

(1) Background: Factors influencing the quality of life (QoL) of patients with chronic rhinosinusitis with nasal polyposis (CRSwNP) are poorly understood. We set out to determine the predictive factors on patients' QoL using the Sino-Nasal Outcome Test-22 (SNOT-22); (2) Methods: An ambispective analysis of data from patients diagnosed with CRSwNP in our institution. All the patients underwent a nasal polyp biopsy and completed the SNOT-22 questionnaire. Demographic and molecular data as well as the SNOT-22 scores were collected. Patients were classified in six subgroups considering the presence of asthma, non-steroidal drugs (NSAID) intolerance and corticosteroid resistance; (3) Results: The mean SNOT-22 score was 39. Considering the clinical parameters, the SNOT-22 value was significantly associated with NSAID intolerance (p = 0.04) and the endoscopic polyp score (p = 0.04). A high SNOT-22 value was also correlated with high tissue eosinophilia (p = 0.01) and high IL-8 expression; (4) Conclusions: Eosinophilia, IL-8 expression and NSAID intolerance can be used as predictors of worse QoL in patients with CRSwNP.

Proposal for Structured Histopathology of Nasal Secretions for Endotyping Chronic Rhinosinusitis: An Exploratory Study

Background: The EPOS guidelines promote cellular analysis as a primary goal in endotyping chronic rhinosinusitis (CRS). Current analysis is mainly based on biopsy or operative tissue collection, whereas the use of sinonasal secretions for inflammatory endotyping is not advocated in clinical practice. Early endotyping is crucial though, especially regarding the increasing evidence of patient-tailored therapy. We aimed to investigate the diagnostic value and reproducibility of sinonasal secretions sampling. Methods: First, preoperative secretion analysis of 53 Caucasian CRS patients was compared to subsequent operative tissue analysis. Second, secretion analysis at two different time points was compared for 10 postoperative Caucasian CRS patients with type 2 (T2) inflammation and 10 control participants. Secretions were collected by both endoscopic aspiration and nasal blown secretions in all participants. Results: The sensitivity to detect T2 inflammation was higher in nasal aspiration samples (85%) compared to nasal blow secretions (32%). A specificity of 100% for both techniques was obtained. A 90% reproducibility for T2 eosinophil detection was found by sampling at different time points regardless of the technique. Of the T2 patients, 60% showed no T2 inflammatory pattern more than one year after endoscopic sinus surgery. Conclusions: Nasal secretion sampling, especially aspiration of nasal secretions, is useful in the detection of T2 inflammation in CRS pathology. We proposed a structured histopathology analysis to be useful in daily clinical practice, which includes Congo red staining sensitive for eosinophilic cells and free eosinophil granules. Analysis of nasal secretions enables endotyping in an early stage, allowing more directed therapy.

Clinical and biological markers in disease and biologics to treat chronic rhinosinusitis

PURPOSE OF REVIEW

Chronic rhinosinusitis (CRS) is a heterogeneous disorder with diverse responses to conventional anti-inflammatory medical and surgical treatments. Even for the newly developed mAbs targeting type 2 (T2) reaction, a considerable number of patients with CRS with nasal polyps (CRSwNP) exhibited unsatisfying response. Identifying patients with a tendency to poor prognosis is critical for selecting targeted therapies to improve the treatment outcome. This review focuses on clinical and biological markers associated with prognosis of CRS patients under conventional medical and surgical treatments and provides an update summary of potential markers for T2 biologics.

RECENT FINDINGS

Allergic rhinitis, asthma, prior sinus surgery, nasal polyps, tissue eosinophilia and neutrophilia, blood eosinophilia and high levels of Charcot-Leyden crystal, cystatin SN, chemokine (C-C motif) ligand 17, macrophage inflammatory protein-1β and interleukin (IL)-5 in nasal secretions have been associated with poor prognosis in CRS patients under conventional medical and surgical treatments. Blood eosinophil level might be a biomarker for anti-IL-5 (mepolizumab) and anti-IL-5R (benralizumab) biologic in patients with refractory CRSwNP.

SUMMARY

Several clinical and biological markers have been associated with poor response to conventional treatments in CRS patients; however, majority of them should be verified by large-scale multicentre studies. More efforts are needed to identify biomarkers for biologics.

Defining the Allergic Endotype of Chronic Rhinosinusitis by Structured Histopathology and Clinical Variables

BACKGROUND

Atopy has a strong association with chronic rhinosinusitis (CRS).

OBJECTIVE

To understand whether patients with atopy and CRS can be defined by markers of tissue histopathology, systemic biomarkers, and clinical factors, which may guide their response to new pharmacologic agents.

METHODS

In a retrospective cohort of CRS patients who underwent functional endoscopic sinus surgery, a structured histopathology report consisting of 12 variables, comorbid conditions, preoperative total serum IgE levels, and preoperative modified Lund-Kennedy endoscopic and sinonasal outcome test (SNOT-22) scores were compared between atopic CRS (aCRS) and non-aCRS control patients in a multivariable model.

RESULTS

A total of 380 CRS patients were enrolled, 286 of whom had comorbid atopy (aCRS). Compared with non-aCRS, aCRS patients had significantly higher preoperative total SNOT-22 scores (40.45 ± 22.68 vs 29.70 ± 20.68, P = .015) and symptom-specific SNOT-22 scores in all domains except psychological dysfunction. Relative to non-aCRS, aCRS patients had increased tissue eosinophilia (P < .0001), eosinophil aggregates (P < .0001), Charcot-Leyden crystals (P < .04), fibrosis (P < .02), total serum IgE levels (P < .04), polyploid disease (P < .001), and a prevalence of comorbid asthma (P < .0001) and aspirin exacerbated respiratory disease (AERD) (P < .003). Patients with aCRS demonstrated increased tissue eosinophilia compared with non-aCRS patients even after controlling for polypoid disease, asthma, and AERD.

CONCLUSION

In the context of CRS, atopy appears to be a specific predictor of CRS severity linked to specific histopathologic variables, including enhanced eosinophilic aggregates. Moving forward, allergic status may be a useful way to identify an atopic endotype of CRS patients. Furthermore, after surgery, patients are often maintained on intranasal corticosteroids. In patients whose disease is unresponsive to steroids, we may look to atopic status to identify another management therapy. Atopic CRS patients, irrespective of polyp and asthmatic status, could be optimal candidates for biologic agents such as T-helper cell, eosinophil, and/or IgE-targeted therapies.

Efficacy and safety of benralizumab in chronic rhinosinusitis with nasal polyps: A randomized, placebo-controlled trial

BACKGROUND

Eosinophilic inflammation has been implicated in the pathogenesis, severity, and treatment responsiveness of chronic rhinosinusitis with nasal polyps (CRSwNP).

OBJECTIVE

We sought to assess the efficacy and safety of benralizumab-mediated eosinophil depletion for treating CRSwNP.

METHODS

The phase 3 OSTRO study enrolled patients with severe CRSwNP who were symptomatic despite treatment with intranasal corticosteroids and who had a history of systemic corticosteroid (SCS) use and/or surgery for nasal polyps (NP). Patients were randomized 1:1 to treatment with benralizumab 30 mg or placebo every 4 weeks for the first 3 doses and every 8 weeks thereafter. Coprimary end points were change from baseline to week 40 in NP score (NPS) and patient-reported mean nasal blockage score reported once every 2 weeks.

RESULTS

The study population comprised 413 randomized patients (207 in the benralizumab group and 206 in the placebo group). Benralizumab significantly improved NPS and nasal blockage score compared to placebo at week 40 (P ≤ .005). Improvements in Sinonasal Outcome Test 22 score at week 40, time to first NP surgery and/or SCS use for NP, and time to first NP surgery were not statistically significant between treatment groups. Nominal significance was obtained for improvement in difficulty in sense of smell score at week 40 (P = .003). Subgroup analyses suggested influences of comorbid asthma, number of NP surgeries, sex, body mass index, and baseline blood eosinophil count on treatment effects. Benralizumab was safe and well tolerated.

CONCLUSION

Benralizumab, when added to standard-of-care therapy, reduced NPS, decreased nasal blockage, and reduced difficulty with sense of smell compared to placebo in patients with CRSwNP.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03401229.

Exploring the role of nasal cytology in chronic rhinosinusitis

Objective

Characterising the eosinophilic profile represents the main step in chronic rhinosinusitis (CRS) endotyping. The aim of the study is to verify the correlation between different methods for tissue eosinophilia quantification.

Methods

33 CRS patients undergoing endoscopic sinus surgery and 30 controls undergoing non-CRS surgeries were enrolled. Blood venous sampling, nasal biopsy on uncinate process (UP), nasal cytology on inferior turbinate (IT) and middle meatus (MM) were performed.

Results

Differences in eosinophil count in blood (P=0.0001), UP (P<0.0001), IT (P = 0.01) and MM (P = 0.0006) were significant between CRS cases and controls. A weak correlation was found between UP and blood eosinophil count (r = 0.34, P = 0.006) and between UP and IT eosinophil count (r = 0.30, P = 0.017). Moderate correlation between UP and MM (r = 0.51, P < 0.0001) was shown. ROC analysis predicted eosinophilic CRS with an overall low sensitivity. Once allergic patients were excluded from the analysis, the sensitivity decreased for sampling on IT and increased for MM sampling.

Conclusions

This study suggests that MM cytology gives more accurate information on the degree of tissue eosinophilia. Replication in wide and unbiased cohorts is necessary to verify these results and define accurate thresholds.

Alteration of Histopathology in Recurrent Nasal Polyps

OBJECTIVE

The objective of this study was to analyze the histopathologic changes in recurrent nasal polyps (NPs) in terms of tissue inflammatory cells infiltration and mucosal remodeling.

METHODS

Thirty-five patients with primary NPs requiring a revision surgery during follow-up and a matched control group of 35 primary NP patients without recurrence were retrospectively enrolled. Histopathologic examination was performed of tissue inflammatory cells, subepithelial edema, epithelial cell hyperplasia, basement membrane thickness, and fibrosis.

RESULTS

The mean eosinophil and neutrophil counts, proportions of eosinophil and neutrophil, as well as total inflammatory cell count were significantly higher in the recurrent group than those in the controls. Higher subepithelial edema was seen in the recurrent group. Within the recurrent group, the mean tissue eosinophil count and relative eosinophilia reduced from the first operation to revision surgery, whereas neutrophil count and proportion, and total inflammatory cell counts remained unchanged. Subepithelial edema and epithelial cell hyperplasia were significantly reduced after the first surgical procedure.

CONCLUSION

NP recurrence is associated with higher inflammatory grade (especially in eosinophilia and neutrophilia). Surgical and corticoid treatments may have an impact on mucosal histopathologic changes but need further certification.

Prognostic and pharmacologic value of cystatin SN for chronic rhinosinusitis with nasal polyps

BACKGROUND

Integrated care pathways improve the management of patients with chronic rhinosinusitis with nasal polyps (CRSwNP). The application of integrated care pathways requires development of endotype-based biomarkers to stratify patients. The value of cytokines and markers induced by cytokines for the management of CRSwNP is largely unknown.

OBJECTIVES

Our aim was to determine the prognostic and pharmacologic value of type 2, non-type 2 cytokines, and markers associated with type 2 inflammation, including CCL26, periostin, and cystatin SN, in nasal secretions for CRSwNP.

METHODS

This retrospective study assigned 151 patients with CRSwNP to the discovery and validation phases. Concentrations of cytokines, CCL26, periostin, and cystatin SN in nasal secretions were determined by using Luminex and ELISA. Predictive significance was assessed with receiver-operating characteristic curves. Survival analysis was performed by using Kaplan-Meier curves and Cox regression models.

RESULTS

Cystatin SN was an independent predictor of the uncontrolled status of CRSwNP over a 2-year follow-up after adjustment for other risk factors (hazard ratio = 1.168 and 1.132 in the discovery and validation phases, respectively; both P < .001). Patients with high cystatin SN concentrations presented with a faster onset and higher rate of uncontrolled status than did those with low levels (P < .001). Enhanced medical treatment for patients with high cystatin SN levels postponed the uncontrolled status in the discovery (P = .016) and validation (P = .002) phases but did not completely abolish it by the end of the follow-up.

CONCLUSION

Cystatin SN levels in nasal secretions hold strong prognostic value and can facilitate medical instructions for managing CRSwNP.

Association of Air Pollutant Exposure and Sinonasal Histopathology Findings in Chronic Rhinosinusitis

BACKGROUND

Ambient air pollution is well known to cause inflammatory change in respiratory epithelium and is associated with exacerbations of inflammatory conditions such as asthma and chronic obstructive pulmonary disease. However, limited work has been done on the impact of air pollution on pathogenesis of chronic rhinosinusitis and there are no reports in the literature of how pollutant exposure may impact sinonasal histopathology in patients with chronic rhinosinusitis.

OBJECTIVE

This study aims to identify associations between certain histopathologic characteristics seen in sinus tissue of patients with chronic rhinosinusitis (CRS) and levels of particulate air pollution (PM_2.5) and ground-level ozone in their place of residence.

METHODS

A structured histopathology report was created to characterize the tissues of CRS patients undergoing sinus surgery. An estimate for each patient's exposure to air pollutants including small particulate matter (PM_2.5) and ground-level ozone was obtained using the Environmental Protection Agency's (EPA) Environmental Justice Screening and Mapping Tool (EJSCREEN). Mean pollutant exposures for patients whose tissues exhibited varying histopathologic features were compared using logistic regression models.

RESULTS

Data from 291 CRS patients were analyzed. Higher degree of inflammation was significantly associated with increased ozone exposure (p = 0.031). Amongst the patients with CRSwNP (n=131), presence of eosinophilic aggregates (p = 0.018) and Charcot-Leyden crystals (p = 0.036) was associated with increased ozone exposure.

CONCLUSION

Exposure to ambient air pollutants may contribute to pathogenesis of CRS. Increasing ozone exposure was linked to both higher tissue inflammation and presence of eosinophilic aggregates and Charcot-Leyden crystals in CRSwNP patients.

Inter-pathologist Agreement on Structured Histopathology Reporting in Chronic Rhinosinusitis

BACKGROUND

Structured histopathology reporting is increasingly being utilized in rhinology to characterize endotypes in chronic rhinosinusitis and guide management decisions after sinus surgery.

OBJECTIVE

The goal of this investigation is to evaluate inter-observer agreement in structured histopathology reporting.

METHODS

Two experienced head and neck pathologists independently compiled structured histopathology reports for tissue samples collected during functional endoscopic sinus surgery. Cohen's standard kappa (κ) coefficients were calculated for each histopathologic variable to assess inter-pathologist agreement.

RESULTS

A total of 92 cases were analyzed. Substantial inter-pathologist agreement was reached on tissue eosinophil count (κ = 0.64, P < .001), the presence of eosinophil aggregates (κ = 0.62, P < .001), and the presence of fungal elements (κ = 0.74, P < .001). There was moderate agreement on the degree of inflammation (κ = 0.56, P < .001) and the presence of squamous metaplasia (κ = 0.46, P < .001). There was fair agreement on the presence of neutrophil infiltrates (κ = 0.33, P < .001), the presence of hyperplastic changes (κ = 0.40, P < .001), and the presence of fibrosis (κ = 0.24, P = .022). There was only slight agreement on the degree of subepithelial edema (κ = 0.20, P = .008). The κ coefficients for basement membrane thickening and mucosal ulceration were not statistically significant.

CONCLUSION

High inter-pathologist agreement was demonstrated for several salient histopathologic variables, including tissue eosinophil count and the presence of eosinophil aggregates. However, refining the definitions of certain histopathologic variables may improve the reproducibility of structured histopathology reporting.

Structured histopathology for endotyping and planning rational treatment in chronic rhinosinusitis

In chronic rhinosinusitis (CRS), endotyping, being based on the pathogenic mechanism, provides a precise picture appropriate for use in clinical practice. Structured histopathological examination of CRS is considered a necessary step in efforts to establish its pathogenesis and improve our endotyping capabilities. Herein we discuss the associations between histopathology and clinical characteristics of CRS patients to assist medical and surgical treatment choices.

Neutrophil infiltrates and eosinophil aggregates in chronic rhinosinusitis with nasal polyps and EGPA

INTRODUCTION/OBJECTIVES

The histopathological study of inflammatory cells and their tendency to form aggregates in chronic rhinosinusitis with nasal polyps (CRSwNP) has shown promising results in determining the pathogenesis and predicting clinical outcome. Bilateral nasal polyps also occur in over 70% of patients with eosinophilic granulomatosis with polyangiitis (EGPA). The study aim was to investigate neutrophil infiltrates and eosinophil aggregates in CRSwNP and EGPA tissues of Caucasian patients.

METHOD

A histopathological study was performed on surgical specimens of nasal polyps from 144 adults (15 with allergic fungal rhinosinusitis; 19 with nonsteroidal anti-inflammatory drugs-exacerbated respiratory disease (NERD); 16 with intrinsic asthma; 21 with extrinsic asthma; 21 with allergy; 22 with eosinophil CRSwNP (ECRSwNP); 17 with non-ECRSwNP; 13 with EGPA).

RESULTS

Focusing on the presence of tissue eosinophil aggregates, NERD and ECRSwNP were the sub-cohorts with the highest rate. Neutrophil infiltrate rate was significantly higher in EGPA sub-cohort than in all CRSwNP sub-cohorts apart from non-ECRSwNP.

CONCLUSIONS

Structured histopathology is increasingly identifying the different histotypes of CRSwNP. This analysis can be used to better understand CRSwNP endotypes and develop targeted therapies. The response to therapy and therefore control of CRSwNP relapses definitely depends on our ability to act on the underlying inflammatory pattern. Key points • Systematic analysis of how neutrophil infiltrates and eosinophilic aggregates are distributed in the different phenotypes of CRSwNP and EGPA. • Neutrophil infiltrates and eosinophil aggregates are strong risk factors for nasal polyps' refractoriness. • NERD and ECRSwNP are the sub-cohorts of CRSwNP with the highest rate of tissue eosinophil aggregates. • Neutrophil infiltrates are significantly higher in EGPA.

Histopathologic Influences of Comorbid Smoking Status in Chronic Rhinosinusitis

Background

Smoking status has been established as a known irritant of the upper and lower respiratory tracts, leading to inflammation throughout the respiratory system. Tobacco smoking is one comorbidity encountered among chronic rhinosinusitis (CRS) patients. The histopathologic features of CRS and comorbid smoking status have yet to be determined by structured histopathology and may have important implications on disease management.

Methods

Retrospective study of structured histopathology reports analyzing sinus tissue removed during functional endoscopic sinus surgery. Histopathology variables were compared among patients with CRS who were reported as never smokers, former smokers, or current smokers.

Results

A total of 285 CRS patients were included: 173 never smokers, 85 former smokers, and 27 current smokers. When compared with former smokers, current smokers demonstrated increased basement membrane thickening (88.9% vs 67.1%, P <.020). Compared with never smokers, former and current smokers collectively demonstrated increased hyperplastic changes (14.3% vs 6.9%, P < .035), increased squamous metaplasia (26.8% vs 17.3%, P < .040), and trends toward increased basement membrane thickening (72.3% vs 65.3%, P < .124) and increased fibrosis (47.3% vs 40.5%, P < .154).

Conclusion

Smoking status may influence histopathologic tissue-level changes in CRS disease. Interestingly, former and current smokers maintained few differences in histopathology. However, former and current smokers collectively demonstrated increased chronic inflammatory changes compared with never smokers. These findings suggest that the timing of smoking exposure has limited effect on the tissue level, rather exposure overall influences inflammatory change. These findings may have important implications on medical and surgical management of CRS disease and comorbid smoking status.

Latest advances in chronic rhinosinusitis with nasal polyps endotyping and biomarkers, and their significance for daily practice

The term chronic rhinosinusitis (CRS) comprises of an assortment of diseases that share a common feature: inflammation of the sinonasal mucosa. The phenotype classification of CRS, based on the presence of polyps, has failed to offer a curative treatment for the disease, particularly in refractory cases. Chronic rhinosinusitis with nasal polyps (CRSwNP) remains a challenging entity. Researchers have made efforts trying to characterize subtypes of the disease according to the endotypes, which are delineated by different immunological pathways, using biomarkers. Even if the inflammatory processes controlling CRSwNP are not fully understood, data suggested that the disease associated with a type 2 inflammatory mechanisms can be also linked to the type 1 or type 3 pathomechanism, being highly heterogeneous. Biomarkers for CRSwNP are proposed, such as: eosinophil count, cytokines, metalloproteinases, bitter and sweet taste receptors, and the nasal microbiome. For endotyping to be clinically applicable and simply determined, biomarkers referring to the intrinsic biomolecular mechanism still need to be found. Precision medicine is becoming the new standard of care, but innovative therapies such as biologics may be rather challenging for the clinicians in their daily practice. This new approach to CRSwNP implies patient selection and a simple algorithm for deciding the right treatment, easy to implement and adjust. Our review points out the ongoing new research on the pathophysiology of CRSwNP, biomarkers and treatment opportunities. It allows clinicians to keep abreast of current evidence-based knowledge and to individualize the management of CRSwNP, especially in refractory cases.

Histopathological characteristics of surgical tissue from primary vs recurrent chronic rhinosinusitis with nasal polyposis patients

OBJECTIVE

The histopathological characteristics of primary vs recurrent nasal polyps in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have not been studied comprehensively. Identification of these features may be helpful for prognostication, postoperative management, and consideration of novel eosinophil-targeting biologic therapy. This study investigates the histopathological differences in primary vs recurrent CRSwNP tissue.

METHODS

Patients undergoing endoscopic sinus surgery for CRSwNP were included if all 13 histopathological and mucin characteristics on a standardized report were available. Histopathology parameters were compared in surgical tissue and mucin from primary vs recurrent CRSwNP.

RESULTS

Complete structured histopathology reports were available for 96 patients (39 primary polyps and 57 recurrent polyps). Compared to primary polyp tissue, recurrent CRSwNP mucin was significantly more likely to feature eosinophil aggregates (57.9% vs 35.9%; P = .047). Tissue eosinophilia (using a threshold >10 per high power field [HPF]) was not significantly different in primary and recurrent CRSwNP tissue. Other histopathologic parameters and clinical characteristics were similar.

CONCLUSION

Eosinophil aggregates on histopathology are significantly more likely to be present in recurrent CRSwNP. In the limited series, tissue eosinophilia (>10 per HPF) was not significantly different in primary and recurrent CRSwNP. Therefore, in addition to the study of tissue eosinophilia levels, Rhinologic surgeons should also direct attention to CRSwNP mucin. Mucin eosinophilic aggregates are an independent marker of severe inflammation that is associated more likely with recurrent vs primary polyposis. Further study of this marker may help determine its role of choice of postoperative medical therapies, including anti-eosinophilic biologics.

LEVEL OF EVIDENCE

4.

Histopathologic Influences of Tissue Eosinophilia Among Chronic Rhinosinusitis Patients

Background

A subset of chronic rhinosinusitis (CRS) patients demonstrates tissue eosinophilia on structured histopathology. Prior studies have suggested that these patients are at increased risk for recurrent disease. The goals of this study are to identify histopathologic features of CRS patients with tissue eosinophilia and compare the influence of tissue eosinophilia to the effects of age and revision surgery on histopathology.

Methods

A structured histopathology report was utilized to analyze sinus tissue removed during functional endoscopic sinus surgery. Binomial logistic regression analysis was conducted to evaluate the association of age at diagnosis, tissue eosinophil count, and history of revision surgery with histopathology variables.

Results

A total of 281 CRS patients were included, of which 106 had tissue eosinophilia. Regression analysis demonstrated that tissue eosinophilia was associated with degree of inflammation (odds ratio [OR] 5.744; P <  .001), neutrophilic infiltrate (OR 1.882; P =  .020), basement membrane thickening (OR 3.561; P <  .001), squamous metaplasia (OR 3.315; P <  .001), fibrosis (OR 2.246; P =  .002), presence of Charcot–Leyden crystals (OR 20.700; P =  .004), and eosinophilic aggregates (OR 34.172; P <  .001). Age and history of revision surgery were not significant predictors of histopathology variables on multivariate analysis.

Conclusion

Tissue eosinophilia appears to be the predominant driving factor of histopathologic changes irrespective of previous sinus surgery or age at diagnosis. These findings may have important implications for postsurgical management and prognosis for patients with tissue eosinophilia presenting for revision surgery.

A classification of chronic rhinosinusitis with nasal polyps based on structured histopathology

AIMS

In chronic rhinosinusitis with nasal polyps (CRSwNP), tools based on objective evidence, such as histopathology, are needed to assist clinical decision-making. The main aim of this exploratory investigation was to determine whether structured histopathology could be used to classify CRSwNP in homogeneous histological clusters.

METHODS AND RESULTS

A cohort of 135 CRSwNP patients was assessed, on the basis of clinicopathological features: allergic fungal rhinosinusitis (17 patients); non-steroidal anti-inflammatory drug-exacerbated respiratory disease (19 patients); intrinsic asthma (18 patients); extrinsic asthma (21 patients); allergy (21 patients); histologically eosinophilic (22 patients); and histologically non-eosinophilic (17 patients). For structured histopathology, we considered: the degree of inflammation; eosinophil count; eosinophil aggregates; neutrophil infiltration; goblet cell hyperplasia; basement membrane thickening; fibrosis; hyperplastic/papillary changes; squamous metaplasia; mucosal ulceration; and subepithelial oedema. Cluster analysis identified four distinct sets of cases. On discriminant analysis, the global error rate was 1.48%, and the stratified error rates were 4.34%, 0%, 0%, and 0% for clusters 1, 2, 3 and 4, respectively. Cluster 1 was characterised by infrequent fibrosis (<4.5% of cases). Cluster 2 mainly featured neutrophil infiltration in 100% of cases, hyperplastic/papillary changes in 70% of cases, and fibrosis in 65% of cases. Cluster 3 showed fibrosis in 100% of cases. Cluster 4 showed hyperplastic/papillary changes in 100% of cases, and fibrosis in 92% of cases.

CONCLUSIONS

This study shows that cluster analysis can identify different histotypes among CRSwNP patients. The next step will be to investigate, in a larger series, the clinical (e.g. prognostic) implications of identifying such homogeneous clusters of patients with CRSwNP on the basis of their structured histopathology.