Concordant systemic and local eosinophilia relates to poorer disease control in patients with nasal polyps

Epithelium-derived kallistatin promotes CD4+ T-cell chemotaxis to TH2-type inflammation in chronic rhinosinusitis

BACKGROUND

The function of kallistatin in airway inflammation, particularly chronic rhinosinusitis with nasal polyps (CRSwNP), has not been elucidated.

OBJECTIVE

We sought to investigate the role of kallistatin in airway inflammation.

METHODS

Kallistatin and proinflammatory cytokine expression levels were detected in nasal polyps. For the in vivo studies, we constructed the kallistatin-overexpressing transgenic mice to elucidate the role of kallistatin in airway inflammation. Furthermore, the levels of plasma IgE and proinflammatory cytokines in the airways were evaluated in the kallistatin-/- rat in vivo model under a type 2 inflammatory background. Finally, the Notch signaling pathway was explored to understand the role of kallistatin in CRSwNP.

RESULTS

We showed that the expression of kallistatin was significantly higher in nasal polyps than in the normal nasal mucosa and correlated with IL-4 expression. We also discovered that the nasal mucosa of kallistatin-overexpressing transgenic mice expressed higher levels of IL-4 expression, associating to TH2-type inflammation. Interestingly, we observed lower IL-4 levels in the nasal mucosa and lower total plasma IgE of the kallistatin-/- group treated with house dust mite allergen compared with the wild-type house dust mite group. Finally, we observed a significant increase in the expression of Jagged2 in the nasal epithelium cells transduced with adenovirus-kallistatin. This heightened expression correlated with increased secretion of IL-4, attributed to the augmented population of CD4+CD45+Notch1+ T cells. These findings collectively may contribute to the induction of TH2-type inflammation.

CONCLUSIONS

Kallistatin was demonstrated to be involved in the CRSwNP pathogenesis by enhancing the TH2 inflammation, which was found to be associated with more expression of IL-4, potentially facilitated through Jagged2-Notch1 signaling in CD4+ T cells.

Association Between Serum Amyloid A Expression and Disease Control after Endoscopic Sinus Surgery in Patients With Chronic Rhinosinusitis With Nasal Polyps

OBJECTIVE

Our previous study revealed that serum amyloid A (SAA) levels in polyp tissues could serve as a biomarker for the prediction of corticosteroid insensitivity in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). However, their association with disease control status in the patients after endoscopic sinus surgery remains to be assessed.

METHODS

Polyp tissues and control uncinate process mucosa were collected from 48 patients with CRSwNP and 10 healthy control subjects. SAA expression was examined using immunohistochemistry and enzyme-linked immunosorbent assay. Receiver operating characteristic (ROC) curves were performed to determine the predictive value of SAA in nasal polyps. The clinical characteristics of 2 CRSwNP subtypes (SAAhigh and SAAlow) were evaluated.

RESULTS

The SAA expression levels in polyp tissues were significantly elevated both in non-eosinophilic and eosinophilic CRSwNP as compared to the healthy controls. In patients with CRSwNP, the tissue SAA level was significantly higher in the disease-controlled patients than those of the partly controlled and uncontrolled. ROC curve analysis revealed that a cut-off value of 114.9 ng/mL for the tissue SAA level predicted the patients with disease-controlled status with 93.33% sensitivity and 63.64% specificity (AUC = .8727, P < .001). Furthermore, The SAAhigh subgroup showed higher tissue eosinophil numbers and percentage of the disease-controlled patients compared to the SAAlow subgroup.

CONCLUSIONS

Our findings suggest that measurements of SAA in polyp tissues may provide useful information for evaluating CRSwNP conditions, especially identifying the CRSwNP patients with disease-controlled status after endoscopic sinus surgery.

ALOX15+ M2 macrophages contribute to epithelial remodeling in eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

Epithelial remodeling is a prominent feature of eosinophilic chronic rhinosinusitis with nasal polyps (eCRSwNP), and infiltration of M2 macrophages plays a pivotal role in the pathogenesis of eCRSwNP, but the underlying mechanisms remain undefined.

OBJECTIVE

We sought to investigate the role of ALOX15+ M2 macrophages in the epithelial remodeling of eCRSwNP.

METHODS

Digital spatial transcriptomics and single-cell sequencing analyses were used to characterize the epithelial remodeling and cellular infiltrate in eCRSwNP. Hematoxylin and eosin staining, immunohistochemical staining, and immunofluorescence staining were used to explore the relationship between ALOX15+ M2 (CD68+CD163+) macrophages and epithelial remodeling. A coculture system of primary human nasal epithelial cells (hNECs) and the macrophage cell line THP-1 was used to determine the underlying mechanisms.

RESULTS

Spatial transcriptomics analysis showed the upregulation of epithelial remodeling-related genes, such as Vimentin and matrix metalloproteinase 10, and enrichment of epithelial-mesenchymal transition (EMT)-related pathways, in the epithelial areas in eCRSwNP, with more abundance of epithelial basal, goblet, and glandular cells. Single-cell analysis identified that ALOX15+, rather than ALOX15-, M2 macrophages were specifically highly expressed in eCRSwNP. CRSwNP with high ALOX15+ M2THP-1-IL-4+IL-13 macrophages had more obvious epithelial remodeling features and increased genes associated with epithelial remodeling and integrity of epithelial morphology versus that with low ALOX15+ M2THP-1-IL-4+IL-13 macrophages. IL-4/IL-13-polarized M2THP-1-IL-4+IL-13 macrophages upregulated expressions of EMT-related genes in hNECs, including Vimentin, TWIST1, Snail, and ZEB1. ALOX15 inhibition in M2THP-1-IL-4+IL-13 macrophages resulted in reduction of the EMT-related transcripts in hNECs. Blocking chemokine (C-C motif) ligand 13 signaling inhibited M2THP-1-IL-4+IL-13 macrophage-induced EMT alteration in hNECs.

CONCLUSIONS

ALOX15+ M2 macrophages are specifically increased in eCRSwNP and may contribute to the pathogenesis of epithelial remodeling via production of chemokine (C-C motif) ligand 13.

Patterns of Olfactory Impairment Among Patients with Uncontrolled Chronic Rhinosinusitis

OBJECTIVES

Self-reported olfactory dysfunction is an assessment component criterion for chronic rhinosinusitis (CRS) disease control of the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS). No studies have objectively explored olfactory function across different psychophysical olfactory domains among patients with uncontrolled CRS. We aimed to investigate the patterns of olfactory impairment in patients with uncontrolled CRS with Sniffin' Sticks test.

METHODS

A total of 79 patients with CRS were prospectively recruited and assessed for disease control based on the EPOS criteria. Sniffin' Sticks test scores, olfactory cleft computed tomography (CT) scores, olfactory cleft endoscopy scale (OCES), questionnaire of olfactory disorders-negative statements (QOD-NS), and sinonasal outcome test-22 (SNOT-22) were obtained. Multiple logistic regression was applied to explore risk factors of uncontrolled CRS.

RESULTS

Twenty-six percent of patients with CRS presented with uncontrolled status. The odor threshold (OT) (p = 0.005), odor identification (OI) (p = 0.041), and thresholds-discrimination-identification (TDI) (p = 0.029) scores were significantly lower in patients with uncontrolled CRS when compared with patients with controlled CRS. Furthermore, patients with uncontrolled CRS presented with a significantly increased percentage of anosmia (p = 0.014), olfactory cleft CT score (p = 0.038), OCES (p = 0.016), QOD-NS(p = 0.008), and SNOT-22 (p < 0.001) scores than patients with controlled CRS. After adjusting for patient demographics, as for the subdomain of olfaction, only the OT score was an independent risk factor for uncontrolled CRS (odds ratio = 0.604; p = 0.030). The OT scores less than 5.950 were the best predictor of uncontrolled CRS.

CONCLUSION

Patients with uncontrolled CRS demonstrated distinct patterns of olfactory impairment, and a reduced olfactory threshold was highly associated with uncontrolled CRS.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:2341-2348, 2024.

Heterogeneity in the definition of chronic rhinosinusitis disease control: a systematic review of the scientific literature

PURPOSE

Disease control is conceptually recognized to be an important outcome measure for chronic rhinosinusitis (CRS). However, inconsistent usage is a significant factor in disadoption of important concepts and it is presently unclear how consistently the construct of CRS 'control' is being defined/applied. The objective of this study was to determine the heterogeneity of CRS disease control definitions in the scientific literature.

METHODS

Systematic review of PubMed and Web of Science databases from inception through December 31, 2022. Included studies used CRS disease control as an explicitly stated outcome measure. The definitions of CRS disease control were collected.

RESULTS

Thirty-one studies were identified with more than half published in 2021 or later. Definitions of CRS control were variable, although 48.4% of studies used the EPOS (2012 or 2020) criteria to define control, 14 other unique definitions of CRS disease control were also implemented. Most studies included the burden CRS symptoms (80.6%), need for antibiotics or systemic corticosteroids (77.4%) or nasal endoscopy findings (61.3%) as criteria in their definitions of CRS disease control. However, the specific combination of these criteria and prior time periods over which they were assessed were highly variable.

CONCLUSION

CRS disease control is not consistently defined in the scientific literature. Although many studies conceptually treated 'control' as the goal of CRS treatment, 15 different criteria were used to define CRS disease control, representing significant heterogeneity. Scientific derivation of criteria and collaborative consensus building are needed for the development of a widely-accepted and -applied definition of CRS disease control.

Vitamin D Levels in Chronic Rhinosinusitis in Patients With or Without Nasal Polyposis: A Systematic Review

Chronic rhinosinusitis (CRS) is a large group of heterogeneous diseases characterized by extensive inflammation of the nasal mucosa and sinuses. Vitamin D (VD), as an immunoregulatory hormone, may play an important role in the pathophysiology of CRS. The purpose of this study is to review the existing literature that correlates VD levels with CRS with or without nasal polyps. A systematic manual search was conducted in the PubMed and Google Scholar databases up to July 2023. Articles from PubMed and the first 100 articles from Google Scholar were recorded for our research. Keywords used were the following: vitamin D, chronic rhinosinusitis, and nasal polyps. Among the 134 articles retrieved, only 18 were eligible. The other 116 studies were excluded as they related VD levels with other conditions (e.g., allergic rhinitis) and for other reasons. However, we identified two more eligible records through the manual research of the above-mentioned 132 studies, and finally, 20 records were included in the current review. The review concerned case-control studies, prospective, retrospective, and cross-sectional studies. Based on our review, we concluded that CRS patients are correlated with the lowest VD levels, accompanied by increased severity of the disease, especially in those with nasal polyposis. Patients can benefit from appropriate VD supplementation, and serum VD levels should be included in the laboratory assessment of CRS. However, due to the heterogeneity of the individuals involved, more well-designed clinical trials as well as randomized clinical trials should be conducted for further validation of the above findings in the general population in the future.

Prognostic factors for post-operative outcomes in chronic rhinosinusitis with nasal polyps: a systematic review

INTRODUCTION

Chronic rhinosinusitis with nasal polyps (CRSwNP) has a high recurrence rate after surgery despite the availability of medical treatments. Multiple clinical and biological factors have been associated with poor post-operative outcomes in patients with CRSwNP. However, these factors and their prognostic values have not yet been extensively summarized.

AREAS COVERED

This systematic review included 49 cohort studies exploring the prognostic factors for post-operative outcomes in CRSwNP. A total of 7802 subjects and 174 factors were included. All investigated factors were classified into three categories according to their predictive value and evidence quality, of which 26 factors were considered plausible for post-operative outcome prediction. Previous nasal surgery, ethmoid-to-maxillary (E/M) ratio, fractional exhaled nitric oxide, tissue eosinophil count or percentage, tissue neutrophil count, tissue IL-5, tissue eosinophil cationic protein, and CLC or IgE in nasal secretion provided more reliable information for prognosis in at least two studies.

EXPERT OPINION

Exploring predictors through noninvasive or minimally invasive methods for specimen collection is recommended for future work. Models combining multiple factors must be established, as no single factor is effective for the whole population.

A novel inflammatory endotype diagnostic model based on cytokines in chronic rhinosinusitis with nasal polyps

Background

Type 2 CRSwNP is characterized by severe symptoms, multiple comorbidities, longer recovery course and high recurrence rate. A simple and cost-effective diagnostic model for CRSwNP endotype integrating clinical characteristics and histopathological features is urgently needed.

Objective

To establish a clinical diagnostic model of inflammatory endotype in CRSwNP based on the clinical characteristics, pathological characteristics, and cytokines profile in the polyp tissue of patients.

Methods

A total of 244 participants with CRSwNP were enrolled at 2 different centers in China and Belgium from 2018 to 2020. IL-5 level of nasal polyp tissue was used as gold standard. Clinical characteristics were used to establish diagnostic models. The area under the receiver operating curve (AUC) was used to evaluate the diagnostic performance. The study was approved by the ethics board of the First Affiliated Hospital of Sun Yat-sen University ([2020] 302), and written informed consent was obtained from all subjects before inclusion.

Results

In total, 134 patients from China (training set) and 110 patients from Belgium (validation set) were included. The logistic regression (LR) model in predicting inflammatory endotype of CRSwNP showed the AUC of 83%, which was better than the diagnostic performance of machine learning models (AUC of 61.14%-82.42%), and single clinical variables. We developed a simplified scoring system based on LR model which shows similar diagnostic performance to the LR model (P = 0.6633).

Conclusion

The LR model in this diagnostic study provided greater accuracy in prediction of inflammatory endotype of CRSwNP than those obtained from the machine learning model and single clinical variable. This indicates great potential for the use of diagnostic model to facilitate inflammatory endotype evaluation when tissue cytokines are unable to be measured.

A review of current biomarkers in chronic rhinosinusitis with or without nasal polyps

INTRODUCTION

Chronic rhinosinusitis (CRS) is a heterogeneous disease with a variety of cellular and molecular pathophysiologic mechanisms. Biomarkers have been explored in CRS using various phenotypes, such as polyp recurrence after surgery. Recently, the presence of regiotype in CRS with nasal polyps (CRSwNP) and the introduction of biologics for the treatment of CRSwNP has indicated the importance of endotypes, and there is a need to elucidate endotype-based biomarkers.

AREAS COVERED

Biomarkers for eosinophilic CRS, nasal polyps, disease severity, and polyp recurrence have been identified. Additionally, endotypes are being identified for CRSwNP and CRS without nasal polyps using cluster analysis, an unsupervised learning technique.

EXPERT OPINION

Endotypes in CRS have still being established, and biomarkers capable of identifying endotypes of CRS are not yet clear. When identifying endotype-based biomarkers, it is necessary to first identify endotypes clarified by cluster analysis for outcomes. With the application of machine learning, the idea of predicting outcomes using a combination of multiple integrated biomarkers, rather than a single biomarker, will become mainstream.

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.

Current understanding of disease control and its application in patients with chronic rhinosinusitis

Background

Disease control is a primary treatment goal for patients with chronic rhinosinusitis (CRS). This study aims to summarize the evaluation parameters of disease control and then identify predictors of poorly controlled CRS.

Methods

A systematic review of the literature was performed on PubMed, Google Scholar, Scopus, and Cochrane databases to identify studies relating to disease control in CRS.

Results

The concept of disease control in patients with CRS involved the longitudinal assessment of the disease state and was also an important goal of treatment. As a metric of the disease state, the disease control reflected the ability to keep disease manifestations within certain limits, the efficacy after treatment, and the impact on quality of life. Validated measurements, such as EPOS2012 criteria, EPOS2020 criteria, Sinus Control Test, and patient/physician-reported global level of CRS control, have been utilized in clinical practice. These existing disease control instruments incorporated various disease manifestations and categorized patients into two (well-controlled and poor-controlled), three (uncontrolled, partly controlled, and controlled), or five (not at all, a little, somewhat, very, and completely) control categories. Eosinophilia, high computerized tomography score, bilateral sinonasal disease, asthma, allergic rhinitis, female gender, aspirin intolerance, revision surgery, low serum amyloid A, and specific T cell subtype would predict poorly controlled CRS.

Conclusion

The concept of disease control and its application were gradually developed in patients with CRS. The existing disease control instruments demonstrated a lack of uniformity regarding the controlled criteria and included parameters.

Identification of Inflammatory Endotypes by Clinical Characteristics and Nasal Secretion Biomarkers in Chronic Rhinosinusitis with Nasal Polyps

INTRODUCTION

The emergency of biologics and surgical techniques targeting the specific inflammatory endotype in chronic rhinosinusitis with nasal polyps (CRSwNP) asks for efficient identification of patients with different endotypes. Although mucosal IL-4, IL-5, IL-13, and IgE have been used to define type 2 (T2) inflammation, the optimal one remains unclear. In this study, we aimed to determine the optimal anchor for T2 inflammation and identify clinical characteristics and nasal secretion biomarkers predicting different endotypes in CRSwNP.

METHODS

Six mediators in sinonasal tissue and 36 mediators in nasal secretion samples were detected by the Bio-Plex suspension array system. Mucosal IFN-γ and IL-17A levels were used to define the T1 and T3 endotype, respectively. The efficacy of mucosal IL-4, IL-5, IL-13, and IgE to define the T2 endotype was compared. The power of clinical characteristics and nasal secretion biomarkers to predict the T1, T2, and T3 endotype was analyzed.

RESULTS

Among mucosal IL-4, IL-5, IL-13, and IgE, IL-13 was the best one to coincide with the expression of other T2 biomarkers. A combination of atopy, facial pain symptom score, ethmoid/maxillary computed tomography score ratio, and blood eosinophil percentage had a moderate predictive performance for T2 endotype (area under the receiver operating curve [AUC] = 0.815), comparable to that of nasal secretion IL-5 (AUC = 0.819). For the T3 endotype, nasal secretion IL-1Rα identified it with an AUC value of 0.756. No efficient marker for the T1 endotype was found.

CONCLUSION

IL-13 is a primary anchor for the T2 endotype in CRSwNP. Clinical characteristics and nasal secretion biomarkers are helpful for identifying the T2 and T3 endotype of CRSwNP.

Pathobiology of Type 2 Inflammation in Asthma and Nasal Polyposis

Asthma and nasal polyposis often coexist and are frequently intertwined by tight pathogenic links, mainly consisting of the cellular and molecular pathways underpinning type 2 airway inflammation. The latter is characterized by a structural and functional impairment of the epithelial barrier, associated with the eosinophilic infiltration of both the lower and upper airways, which can be driven by either allergic or non-allergic mechanisms. Type 2 inflammatory changes are predominantly due to the biological actions exerted by interleukins 4 (IL-4), 13 (IL-13), and 5 (IL-5), produced by T helper 2 (Th2) lymphocytes and group 2 innate lymphoid cells (ILC2). In addition to the above cytokines, other proinflammatory mediators involved in the pathobiology of asthma and nasal polyposis include prostaglandin D₂ and cysteinyl leukotrienes. Within this context of 'united airway diseases', nasal polyposis encompasses several nosological entities such as chronic rhinosinusitis with nasal polyps (CRSwNP) and aspirin-exacerbated respiratory disease (AERD). Because of the common pathogenic origins of asthma and nasal polyposis, it is not surprising that the more severe forms of both these disorders can be successfully treated by the same biologic drugs, targeting many molecular components (IgE, IL-5 and its receptor, IL-4/IL-13 receptors) of the type 2 inflammatory trait.

Cluster analysis of patients with chronic rhinosinusitis and asthma after endoscopic sinus surgery

BACKGROUND

Patients with chronic rhinosinusitis with nasal polyps and asthma (CRSwAS) are highly heterogenous in severity and prognosis. The clinical phenotypes and inflammatory endotypes of CRSwAS and their association with outcomes of endoscopic sinus surgery (ESS) have not been fully studied yet.

OBJECTIVE

We aimed to find out the clinical phenotypes of CRSwAS and explore their relationship with ESS outcomes using cluster analysis.

METHODS

We recruited 103 consecutive adult patients with CRSwAS who had undergone ESS and been followed up for more than 1 year. For cluster analysis, we collected the data from 63 variables pertaining to demographic characteristics, preoperative disease status, surgical techniques, postoperative medical treatment, and outcomes. Eosinophilic CRS was defined as greater than or equal to 10 eosinophils/high-power field, and sinus computed tomography was evaluated by Lund-Mackay sinus computed tomography score (LM score).

RESULTS

We screened 92 eligible patients and 13 preoperative variables for balanced iterative reducing and clustering using hierarchies cluster analysis. Patients with CRSwAS were divided into 4 clusters with distinct ESS outcomes: (1) cluster 1, characterized by aspirin-exacerbated respiratory disease, eosinophilic CRS, high preoperative LM score, moderate-to-severe asthma, and uncontrolled CRS after ESS; (2) cluster 2, characterized as having female dominance (66.67%), non-aspirin-exacerbated respiratory disease, eosinophilic CRS, high preoperative LM score, moderate-to-severe asthma, and uncontrolled CRS after ESS; (3) cluster 3, characterized as having female dominance (95.83%), noneosinophilic CRS, low preoperative LM score, moderate asthma, and controlled CRS after ESS; and (4) cluster 4, characterized as men-only, smoker, noneosinophilic CRS, low preoperative LM score, mild asthma, and controlled CRS after ESS.

CONCLUSION

CRSwAS has distinct clusters, each corresponding to unique clinical and inflammatory characteristics and ESS outcomes.

The Role of Nasal Cytology and Serum Atopic Biomarkers in Paediatric Rhinitis

A Nasal Provocation Test allows the differentiation of allergic and non-allergic rhinitis, but it is difficult and expensive. Therefore, nasal cytology is taking hold as an alternative. We carried out a cross-sectional study, including 29 patients with persistent rhinitis according to ARIA definition and negative skin prick tests. Nasal symptoms were scored from 0 to 5 using a visual analogue scale, and patients underwent blood tests to investigate blood cell count (particularly eosinophilia and basophilia), to analyze serum total and specific IgE and eosinophil cationic protein (ECP), and to perform nasal cytology. We performed a univariate logistical analysis to evaluate the association between total serum IgE, serum eosinophilia, basophils, and ECP and the presence of eosinophils in the nasal mucosa, and a multivariate logistic model in order to weight the single variable on the presence of eosinophils to level of the nasal mucosa. A statistically significant association between serum total IgE levels and the severity of nasal eosinophilic inflammation was found (confidence interval C.I. 1.08-4.65, odds ratio OR 2.24, p value 0.03). For this reason, we imagine a therapeutic trial with nasal steroids and oral antihistamines in patients with suspected LAR and increased total IgE levels, reserving nasal cytology and NPT to non-responders to the first-line therapy.

The roles of eosinophils and interleukin-5 in the pathophysiology of chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is generally associated with eosinophilic tissue infiltration linked to type 2 inflammation and characterized by elevated levels of interleukin (IL)-5 and other type 2 inflammatory mediators. Although distinct and overlapping contributions of eosinophils and IL-5 to CRSwNP pathology are still being explored, they are both known to play an important role in NP inflammation. Eosinophils secrete numerous type 2 inflammatory mediators including granule proteins, enzymes, cytokines, chemokines, growth factors, lipids, and oxidative products. IL-5 is critical for the differentiation, migration, activation, and survival of eosinophils but is also implicated in the biological functions of mast cells, basophils, innate lymphoid cells, B cells, and epithelial cells. Results from clinical trials of therapeutics that target type 2 inflammatory mediators (including but not limited to anti-IL-5, anti-immunoglobulin-E, and anti-IL-4/13) may provide further evidence of how eosinophils and IL-5 contribute to CRSwNP. Finally, the association between eosinophilia/elevated IL-5 and greater rates of NP recurrence after endoscopic sinus surgery (ESS) suggests that these mediators may have utility as biomarkers of NP recurrence in diagnosing and assessing the severity of CRSwNP. This review provides an overview of eosinophil and IL-5 biology and explores the literature regarding the role of these mediators in CRSwNP pathogenesis and NP recurrence following ESS. Based on current published evidence, we suggest that although eosinophils play a key role in CRSwNP pathophysiology, IL-5, a cytokine that activates these cells, also represents a pertinent and effective treatment target in patients with CRSwNP.

Elucidating the Real-World Burden of Chronic Rhinosinusitis With Nasal Polyps in Patients in the USA

Objective

To characterize healthcare burden, treatment patterns, and clinical characteristics associated with chronic rhinosinusitis with nasal polyps (CRSwNP).

Study Design

Retrospective cohort.

Setting

Real-world study using US health insurance claims database.

Methods

Adults with ≥1 CRSwNP diagnosis (index date: first claim for nasal polyps [NPs] between January 1, 2008, and March 31, 2019) and continuous health insurance coverage for ≥180 days preindex (baseline) and postindex were included. Follow-up spanned from index to the earliest of disenrollment, death, or data end. Assessments included patient demographics, comorbidities, and blood eosinophil count at baseline, healthcare resource utilization (HCRU), and costs during follow-up in the overall population and stratified by number of surgeries.

Results

Of the 119,357 patients who met the inclusion criteria, 33,748 (28%) had ≥1 surgery during follow-up, among whom 3262 (9.7%) had ≥2 surgeries. At baseline, patients with ≥1 vs no NP surgeries had a greater comorbidity burden; a higher proportion of patients had comorbid asthma (37.8% vs 21.8%) and blood eosinophil count ≥300 cells/µL (42.6% vs 38.1%). During follow-up, patients with NP surgeries had higher all-cause and CRSwNP-related HCRU and costs than patients without NP surgery. All-cause healthcare costs per person per year increased with the number of surgeries during follow-up (no surgery, $10,628; ≥1 surgery, $20,747; ≥2 surgeries, $26,969).

Conclusion

Patients with CRSwNP and surgery had a greater disease burden than those without surgery, with higher HCRU and costs, and were more likely to have comorbid conditions (most commonly asthma) and elevated blood eosinophil count, indicating a subset of patients with recalcitrant CRSwNP.

Deep Learning-Based Prediction of Treatment Prognosis from Nasal Polyp Histology Slides

BACKGROUND

Histopathology of nasal polyps contains rich prognostic information, which is difficult to objectively extract. In the present study, we aimed to develop a prognostic indicator of patient outcomes by analyzing scanned conventional haematoxylin and eosin (H&E) -stained slides alone using deep learning.

METHODS

An interpretable supervised deep learning model was developed using 185 H&E-stained whole-slide images (WSIs) of nasal polyps, each from a patient randomly selected from the pool of 232 patients who underwent endoscopic sinus surgery at the First Affiliated Hospital of Sun Yat-sen University (internal cohort). We internally validated the model on a holdout dataset from the internal cohort (47 H&E-stained WSIs) and externally validated the model on 122 H&E-stained WSIs from the Seventh Affiliated Hospital of Sun Yat-sen University and the University of Hong Kong-Shenzhen Hospital (external cohort). A poor prognosis score (PPS) was established to evaluate patient outcomes, and then risk activation mapping was applied to visualize the histopathological features underlying PPS.

RESULTS

The model yielded a patient-level sensitivity of 79.5%, and specificity of 92.3%, with areas under the receiver operating characteristic curve of 0.943, on the multi-center external cohort. The predictive ability of PPS was superior to that of conventional tissue eosinophil number. Notably, eosinophil infiltration, goblet cell hyperplasia, glandular hyperplasia, squamous metaplasia, and fibrin deposition were identified as the main underlying features of PPS.

CONCLUSIONS

Our deep learning model is an effective method for decoding pathological images of nasal polyps, providing a valuable solution for disease prognosis prediction and precise patient treatment. This article is protected by copyright. All rights reserved.

A novel risk score for disease control prediction of Chronic rhinosinusitis

Objectives

To assess the impact of risk factors on the disease control among chronic rhinosinusitis (CRS) patients, following 1 year of functional endoscopic sinus surgery (FESS), and combining the risk factors to formulate a convenient, visualised prediction model.

Design

A retrospective and nonconcurrent cohort study.

Setting and Participants

A total of 325 patients with CRS from June 2018 to July 2020 at the First Affiliated Hospital of Sun Yat‐sen University, the Third Affliated Hospital of Sun Yat‐sen University, the Seventh Affiliated Hospital of Sun Yat‐sen University.

Main Outcomes Measures

Outcomes were time to event measures: the disease control of CRS after surgery 1 year. The presence of nasal polyps, smoking habits, allergic rhinitis (AR), the ratio of tissue eosinophil (TER) and peripheral blood eosinophil count (PBEC) and asthma was assessed. The logistic regression models were used to conduct multivariate and univariate analyses. Asthma, TER, AR, PBEC were also included in the nomogram. The calibration curve and area under curve (AUC) were used to evaluate the forecast performance of the model.

Results

In univariate analyses, most of the covariates had significant associations with the endpoints, except for age, gender and smoking. The nomogram showed the highest accuracy with an AUC of 0.760 (95% CI, 0.688–0.830) in the training cohort.

Conclusions

In this cohort study that included the asthma, AR, TER, PBEC, which had significantly affected the disease control of CRS after surgery. The model provided relatively accurate prediction in the disease control of CRS after FESS and served as a visualised reference for daily diagnosis and treatment.

Clinical characteristics of patients with CRSwNP with intensely high eosinophil level

Background

High tissue and blood eosinophils are linked to poor treatment outcome in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). However, the difference between the patients with different level of blood or tissue eosinophilia in relation to disease control is still lacking.

Objectives

This study aimed to characterize patients with CRSwNP with intensely high eosinophil level.

Methods

A retrospective study of CRSwNP patients underwent endoscopic sinus surgery was conducted. The patients were subdivided with various cut‐off values of blood and tissue eosinophils. Tissue eosinophils of ≥50% and 10%–20% were defined as intensely high tissue eosinophils (IH‐tissue‐eos) and high tissue eosinophils (H‐tissue‐eos), respectively. Blood eosinophils of ≥0.6 × 10⁹/L and 0.2 × 10⁹/L–0.3 × 10⁹/L were defined as intensely high blood eosinophils (IH‐blood‐eos) and high blood eosinophils (H‐blood‐eos). Clinical characteristics, Lund‐Mackay score (LMS), and disease control status were compared between subgroups.

Results

A total of 302 patients were enrolled. There was a trend toward a higher rate of uncontrolled disease when the patients subdivided by blood eosinophil cut‐off values ranged from 0.1 × 10⁹/L to 0.6 × 10⁹/L. The controlled patients accounted for 27%, 36%, 22%, and 31%, and the uncontrolled patients 46%, 32%, 52%, and 31% of patients in IH‐tissue‐eos, H‐tissue‐eos, IH‐blood‐eos, and H‐blood‐eos subgroup, respectively. The percentages of patients in the three categories of control were not significantly different between IH‐tissue‐eos and H‐tissue‐eos subgroups. By contrast, the IH‐blood‐eos subgroup had higher percentages of current smoker and asthma, preoperative LMS and tissue eosinophil percentage, and showed a trend toward a higher rate of uncontrolled subjects compare with the H‐blood‐eos subgroup.

Conclusion

CRSwNP patients with IH‐blood‐eos (≥0.6 × 10⁹/L) may be possibly associated with a poorer disease control than those with levels near the threshold of blood eosinophilia (0.2 × 10⁹/L–0.3 × 10⁹/L). Further larger, preferably prospective studies are needed to confirm this relationship.

Level of Evidence: 4.

Mepolizumab for chronic rhinosinusitis with nasal polyps: treatment efficacy by comorbidity and blood eosinophil count

BACKGROUND

In the Phase III SYNAPSE study, mepolizumab reduced nasal polyp (NP) size and nasal obstruction in chronic rhinosinusitis with NP (CRSwNP).

OBJECTIVE

To assess the efficacy of mepolizumab in patients from SYNAPSE grouped by comorbid asthma, aspirin-exacerbated respiratory disease (AERD), and baseline blood eosinophil count (BEC).

METHODS

SYNAPSE, a randomized, double-blind, 52-week study (NCT03085797), included patients with severe bilateral CRSwNP eligible for surgery despite intranasal corticosteroid treatment. Patients received 4-weekly subcutaneous mepolizumab 100 mg or placebo plus standard of care for 52 weeks. Co-primary endpoints were change in total endoscopic NP score (Week 52) and nasal obstruction visual analog scale (VAS) score (Weeks 49-52). Subgroup analyses by comorbid asthma and AERD status, and post hoc by BEC, were exploratory.

RESULTS

Analyses included 407 patients (289 with asthma; 108 with AERD; 371 and 278 with BEC counts ≥150 or ≥300 cells/μL, respectively). The proportion of patients with ≥1-point improvement from baseline in NP score was higher with mepolizumab versus placebo across comorbid diseases (asthma: 52.9% vs 29.5%; AERD: 51.1% vs 20.6%) and baseline BEC subgroups (<150 cells/μL: 55.0% vs 31.3%; ≥150 cells/μL: 49.5% vs 28.1%; <300 cells/μL: 50.7% vs 29.0%; ≥300 cells/μL: 50.4% vs 28.1%). A similar trend was observed in patients without comorbid asthma or AERD. More patients had >3-point improvement in nasal obstruction VAS score with mepolizumab versus placebo across comorbid subgroups.

CONCLUSION

Mepolizumab reduced polyp size and nasal obstruction in CRSwNP regardless of the presence of comorbid asthma or AERD.

CLINICAL IMPLICATION

Mepolizumab should be considered for the treatment of CRSwNP, particularly in patients with comorbid asthma or AERD.

Immunopathologic characteristics of Chinese pediatric patients with chronic rhinosinusitis

Background

The histopathology of pediatric chronic rhinosinusitis with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP) is rarely reported due to low prevalence or the unavailability of tissue samples. Hence, we aimed to characterize and compare the histologic features and protein expression of Th1/Th2/Th17-related cytokines in pediatric CRSsNP and CRSwNP.

Methods

The histologic characteristics of 15 children with CRSsNP, 52 children with CRSwNP, and 12 control participants were analyzed using hematoxylin and eosin staining. The expression of Th1/Th2/Th17-related cytokines were examined using immunohistochemistry and the enzyme-linked immunosorbent assay.

Results

Pediatric subjects with CRSwNP had more intact epithelium and less submucosal mucous glands compared to those with CRSsNP. Tissue eosinophils were more prevalent in the younger CRSwNP group compared to the older CRSwNP or the CRSsNP groups. The protein concentrations of Th2 cytokines were significantly higher in the CRSwNP group than the CRSsNP group or the control group. Moreover, the protein concentrations of Th17 cytokines were significantly higher in the younger CRSwNP group than the older CRSwNP group or the CRSsNP and control groups. The protein concentrations of Th1 and Th17 cytokines were also significantly higher in the CRSsNP group than the control group. Compared with non-eosinophilic CRSwNP, eosinophilic CRSwNP presented with elevated protein concentrations of Th1 and Th17 cytokines.

Conclusion

For the first time, we showed that pediatric CRSwNP presents as eosinophilic with Th2/Th17 inflammation, whereas CRSsNP presents as Th1/Th17 inflammation. Our study may provide a theoretical basis for the precise treatment of pediatric CRS in the future.

A Comprehensive Analysis of the Stability of Blood Eosinophil Levels

Rationale: Blood eosinophil counts are used to inform diagnosis/management of eosinophilic asthma. Objectives: Examine blood eosinophil variability and identify factors affecting eosinophil levels to inform clinical interpretation. Methods:Post hoc analysis to understand eosinophil variability using data from four randomized controlled asthma trials. We examined 1) influence of intrinsic/extrinsic factors (comorbidities, medication, and patient history) using baseline data (n = 2,612); 2) monthly variation using placebo-treated patient data (n = 713); 3) stability of eosinophil classification (<150, 150-299, and ⩾300 cells/μl) in placebo-treated patients with monthly measurements over a 1-year period (n = 751); and 4) impact of technical factors (laboratory-to-laboratory differences and time from collection to analysis). Results: Of intrinsic/extrinsic factors examined, nasal polyps increased eosinophil levels by 38%, whereas current smoking decreased levels by 23%. Substantial seasonal differences in eosinophil counts were observed, with differences of ∼20% between July and January. Eosinophil levels between 150 and 299 cells/μl were least stable, with 44% of patients remaining in the same classification for seven of 10 measurements versus 59% and 66% of patients in the <150 and ⩾300 cells/μl subgroups, respectively. Measurements at different laboratories showed high association (Spearman's correlation coefficient, R = 0.89); however, eosinophil counts were reduced, with longer time from collection to analysis, and variability increased with increasing eosinophil counts. Conclusions: Several intrinsic, extrinsic, and technical factors may influence, and should be considered in, clinical interpretation of eosinophil counts. Additionally, a single measurement may not be sufficient when using eosinophil counts for diagnosis/management of eosinophilic asthma.

Defining the Efficacy of Omalizumab in Nasal Polyposis: A POLYP 1 and POLYP 2 Subgroup Analysis

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease with variable underlying pathophysiologies. Numerous patient factors have been linked to differences in disease severity, control, and response to treatment, including asthma status, aspirin sensitivity, previous sinonasal surgery, and blood eosinophil levels.

OBJECTIVE

The present study examines the efficacy of the anti-immunoglobulin E therapy, omalizumab, versus placebo in patients with CRSwNP from the replicate POLYP 1 (NCT03280550) and POLYP 2 (NCT03280537) trials, grouped by inherent patient characteristics to determine the response to therapy.

METHODS

Patients in prespecified subgroups from POLYP 1 and POLYP 2 (studies pooled for analysis) were examined. Subgroups included blood eosinophil count at baseline (>300 or ≤300 cells/μL), previous sinonasal surgery (yes or no), asthma status (yes or no), and aspirin sensitivity status (yes or no). Subgroups were examined for subgroup-specific adjusted mean difference (95% confidence interval [CI]) (omalizumab-placebo) in change from baseline at week 24 in Nasal Congestion Score (NCS), Nasal Polyp Score (NPS), Sino-Nasal Outcome Test-22 (SNOT-22), Total Nasal Symptom Score (TNSS), and University of Pennsylvania Smell Identification Test (UPSIT).

RESULTS

Adjusted mean difference (95% CI) (omalizumab-placebo) in NCS, NPS, SNOT-22, TNSS, and UPSIT change from baseline at week 24 consistently favored omalizumab treatment over placebo in patients with blood eosinophil count >300 and ≤300 cells/μL, with or without previous sinonasal surgery, asthma, and aspirin sensitivity.

CONCLUSION

Together, these data suggest broad efficacy of omalizumab across clinical and patient-reported outcomes in patients with CRSwNP, independent of the underlying patient factors examined, including those with high eosinophil levels and those who have undergone previous surgery, which are associated with high recurrence.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifiers: POLYP 1: ClinicalTrials.gov identifier NCT03280550 (https://clinicaltrials.gov/ct2/show/NCT03280550); POLYP 2: ClinicalTrials.gov identifier NCT03280537 (https://clinicaltrials.gov/ct2/show/NCT03280537).

Role of Vitamin D in the Clinical Course of Nasal Polyposis

Vitamin D is a lipo-soluble hormone well known for its effects on calcium homeostasis and bone metabolism. Recently, there has been growing interest in the extraskeletal effects of vitamin D. In particular, recent studies have highlighted how vitamin D plays a fundamental role in immunomodulation processes in the context of both innate and adaptive immunity, with consequent anti-inflammatory and anti-oxidant effect in different immune-mediated pathologies, such as systemic sclerosis, psoriasis, atopic dermatitis and rheumatoid arthritis; as well as in various pro-inflammatory processes affecting the airways, including chronic rhinosinusitis with (CRSwNP) or without (CRSsNP) nasal polyposis. We analyze the role of vitamin D in the genesis and progression of CRSwNP/sNP and its supplementation as a safe and valid therapeutic strategy capable of improving the clinical outcome of standard therapies.

Real-life effects of benralizumab on allergic chronic rhinosinusitis and nasal polyposis associated with severe asthma

The aim of this study has been to evaluate the efficacy of the IL-5 receptor blocker benralizumab on chronic rhinosinusitis with nasal polyposis (CRSwNP), associated with severe eosinophilic allergic asthma. Ten patients with severe eosinophilic allergic asthma and CRSwNP were enrolled. Sino-nasal outcome test (SNOT-22), numerical rating scale (NRS), endoscopic nasal polyp score, Lund Mackey CT (computed tomography) score, and blood eosinophil count were measured at baseline and after 24 weeks of treatment with benralizumab. All the above clinical, endoscopic, imaging, and hematological parameters significantly improved after 24 weeks of treatment with benralizumab. In particular, SNOT-22 decreased from 61.10 ± 17.20 to 26.30 ± 19.74 (P < 0.001), NRS decreased from 7.20 ± 1.55 to 3.40 ± 2.22 (P < 0.001), the endoscopic polyp nasal score decreased from 4.20 ± 1.32 to 2.50 ± 1.78 (P < 0.001), the Lund-Mackay CT score decreased from 16.60 ± 5.50 to 6.90 ± 5.99 (P < 0.001), and blood eosinophil count decreased from 807.3 ± 271.1 cells/μL to 0 cells/μL (P < 0.0001). These results strongly suggest that benralizumab exerted a very effective therapeutic action on CRSwNP associated with severe asthma, thus improving nasal symptoms and decreasing polyp size.

A Nomogram Combing Peripheral Parameters for Estimation of CRSwNP Recurrence

BACKGROUND

The preoperative prediction of the recurrence of chronic rhinosinusitis with nasal polyps (CRSwNP) remains difficult in clinical practice.

OBJECTIVE

We aimed to develop a nomogram that combined peripheral risk factors to clinically predict the recurrence of CRSwNP.

METHODS

Data from 158 CRSwNP patients who underwent endoscopic sinus surgery (ESS) from January 2012 to December 2016 were collected, and the patients were followed up for 3 years. Of these, 96 patients who underwent ESS in an earlier period formed the training cohort for nomogram development, and 62 patients who underwent ESS thereafter formed the validation cohort to confirm the model's performance. Risk factors for recurrence identified by univariate and multivariate logistic regression were used to create a nomogram.

RESULTS

The recurrence rate was 29.2% (28/96) for the training cohort and 35.5% (22/62) for the validation cohort. Univariate analysis identified blood eosinophils (Eos), serum IgE level, asthma comorbidity, and the number of previous ESSs as risk factors for recurrence. Among those four parameters, serum IgE level and a previous ESS surgery were identified as two independent risk factors. A nomogram consisting of blood Eos, total serum IgE level, asthma comorbidity, and the number of previous ESSs was constructed, demonstrating a C index of 0.81 (95% CI, 0.79-0.83) and 0.80 (95% CI, 0.77-0.83) for predicting recurrence in the training and validation cohorts, respectively. The nomogram had well-fitted calibration curves.

CONCLUSION

The nomogram might be able to preoperatively predict the recurrence of CRSwNP by using currently available and objective parameters. Further studies are required to validate its reliability and effectiveness.

Inflammatory features and predictors for postsurgical outcomes in patients with nasal polyps stratified by local and systemic eosinophilia

BACKGROUND

In this study we aimed to identify inflammatory patterns and predictors associated with clinical outcomes in chronic rhinosinusitis with nasal polyps (CRSwNP) patients with different blood and tissue eosinophilia.

METHODS

A total of 535 CRSwNP patients were enrolled, and the expression of 35 biomarkers, together with eosinophil and neutrophil counts in nasal polyps, were analyzed in a subset of 249 patients. Patients were stratified on the basis of blood (≥0.5 × 10⁹ /L) and tissue (>10%) eosinophilia. Logistic regression models were applied to identify predictors of uncontrolled disease at least 1 year after surgery. Uncontrolled disease was defined according to the European Position Paper on Rhinosinusitis and Nasal Polyps 2020.

RESULTS

Among 535 patients, 38.5% showed inconsistent blood and tissue eosinophilia. In 249 CRSwNP patients, subjects with concomitant blood and tissue eosinophilia (group 1) showed marked mucosal type 2 inflammation, characterized by high levels of interleukin (IL)-5, IL-13, and eotaxin-1, whereas subjects with normal blood and tissue eosinophil levels (group 4) demonstrated significant local neutrophilic inflammation with high expression of granulocyte colony-stimulating factor and subjects with selective tissue eosinophilia (group 2) showed intermediate and mixed eosinophilic and neutrophilic inflammation. Subjects with isolated blood eosinophilia (group 3) showed low expression of vascular endothelial growth factor and IL-10. Asthma, prior sinus surgery, and blood eosinophilia were the top 3 predictors for postsurgical uncontrolled disease. For subgroup analysis, sex in group 1, asthma in group 2, tissue IL-10 and immunoglobulin E in group 3, and prior sinus surgery in group 4 were the strongest predictors of uncontrolled disease, respectively.

CONCLUSION

Different blood and tissue eosinophilia revealed distinct tissue inflammatory patterns in CRSwNP patients.

Assessing Cut-off Points of Eosinophils, Nasal Polyp, and Lund-Mackay Scores to Predict Surgery in Nasal Polyposis: A Real-World Study

Background

Developing tools to identify chronic rhinosinusitis with nasal polyps (CRSwNP) patients requiring surgical treatment would help clinicians treat patients more effectively. The aim of this retrospective cross-sectional study was to identify cut-off values ​​for eosinophil percentage, nasal polyps (NP), and Lund-Mackay (LM) scores that may predict the need for surgical treatment in Finnish CRSwNP patients.

Methods

Data of CRSwNP patients (N = 378) undergoing consultation for ESS in 2001–19 were used. Data was collected from patient records and Lund-Mackay scores were determined from sinus computed tomography scans. The percentage of eosinophils was microscopically evaluated from the polyp samples available (n = 81). Associations were analyzed by Mann Whitney U test, and cut-off values by the area under the receiver operating characteristic curve (AUROC).

Results

ESS was performed to 293 (77.5%) of patients. Polyp eosinophilia was associated significantly with ESS (p = 0.001), whereas peripheral blood eosinophil count, LM- score and endoscopic NP- score were not (p > 0.05). AUROC values (95% CI) for detecting those needing ESS were for polyp eosinophilia 0.71 (0.60–0.83), p = 0.001, for LM score 0.59 (0.50–0.67), p = 0.054; for NP score 0.56 (0.48–0.64), p = 0.17, and for blood eosinophil count 0.68 (0.46–0.90), p = 0.08. With the threshold value of polyp eosinophilia (>25%), the sensitivity and specificity were optimal for detecting the group needing ESS from the group not undergoing ESS. The cut-off value of blood eosinophil count (>0.26 × 10⁹/L) had relatively good, yet statistically insignificant (underpowered), predictive potential. Moderate cut-off values were found for endoscopic LM score (≥14/24) and NP score (≥4/8).

Conclusions

Polyp eosinophilia (>25%) predicted ESS among Finnish hospital-level CRSwNP patients. A future challenge would be to find less invasive and cost-effective clinical factors predicting uncontrolled CRSwNP.