Mucosal eosinophilia and recurrence of nasal polyps - new classification of chronic rhinosinusitis

Significance as a Prognostic Factor of Eosinophil Count in Nasal Polyp Tissue in Patients with Chronic Rhinosinusitis Accompanied by Asthma

Background/Objectives: Patients with chronic rhinosinusitis (CRS) accompanied by asthma often show poor prognoses and require continuous management. This study aimed to assess the prognostic value of eosinophil counts in nasal polyp tissue for selecting individuals who would benefit from ongoing management in CRS patients with asthma. Methods: Patients with asthma who underwent endoscopic sinus surgery for CRS with nasal polyps were included in the study. Eosinophil counts in nasal polyp tissues were quantified, and retrospective data were collected from laboratory and clinical findings, including endoscopic examinations, CT scans, and Japan Endoscopic Sinus Surgery Rating and Evaluation Committee (JESREC) scores. Disease control status was evaluated through endoscopic examination 6 months post-surgery. Results: A total of 42 patients were divided into two groups based on their disease management status 6 months post-operation: the well-control group (24 patients, 57.14%) and the poor-control group (18 patients, 42.86%). Demographics and laboratory findings did not show significant differences between the groups. However, the JESREC score (p = 0.04) and tissue eosinophil count (p = 0.02) were significantly different. Multivariate analysis identified tissue eosinophil count as the only risk factor associated with prognosis, with a cut-off value of 90/HPF. Conclusions: In CRS patients with asthma, high tissue eosinophil counts in nasal polyps were associated with poor disease control, which is the most potent predictor of prognosis. The assessment of eosinophil counts in nasal polyp tissue could aid in identifying patients who would benefit from continuous management and tailored interventions for improved outcomes.

Functions and Clinical Applications of Extracellular Vesicles in TH2 Cell-Mediated Airway Inflammatory Diseases: A Review

Type 2 airway inflammation (T2AI), driven by type 2 innate lymphoid and CD4+ T helper 2 cells, leads to various diseases and conditions, such as chronic rhinosinusitis with nasal polyps, allergic rhinitis, and asthma. Emerging evidence suggests the involvement of extracellular vesicles (EVs) in these diseases. In this review, we describe the immunological T2AI pathogenic mechanisms, outline EV characteristics, and highlight their applications in the diagnosis and treatment of T2AI. An extensive literature search was conducted using appropriate strategies to identify relevant articles from various online databases. EVs in various biological samples showed disease-specific characteristics for chronic rhinosinusitis with nasal polyps, allergic rhinitis, and asthma, with some demonstrating therapeutic effects against these conditions. However, most studies have been limited to in vitro and animal models, highlighting the need for further clinical research on the diagnostic and therapeutic applications of EVs.

Diagnostic criteria for eosinophilic chronic rhinosinusitis: Comparative analysis and novel scoring system

BACKGROUND

Accurate identification of eosinophilic chronic rhinosinusitis is essentialg because its treatment and prognosis substantially differ from other subtypes.

METHODS

This retrospective observational study included 640 patients who underwent endoscopic sinus surgery for chronic rhinosinusitis in a single tertiary center from January 2021 to December 2022. Receiver operating characteristic curves were generated to compare accuracy, sensitivity, specificity of the novel scoring system, and previous diagnostic criteria (Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis, European Forum for Research and Education in Allergy and Airway Diseases, European Position Paper on Rhinosinusitis and Nasal Polyps, and Sakuma et al.) for predicting eosinophilic chronic rhinosinusitis (ECRS) by tissue eosinophil count ≥70 per high power field.

RESULTS

Patients were randomly divided into estimation (n = 430) and validation (n = 210) groups. The area under the receiver operating characteristic curve for the novel score was 0.753 (95% confidence interval [CI], 0.670-0.835) in the estimation group, 0.729 (0.629-0.830) in the validation group, and 0.661 (0.584-0.738) in the 20-fold cross-validation with the entire dataset.

CONCLUSIONS

We propose a novel scoring system that incorporates three key parameters: "novel score = blood eosinophil (%) + total Lund-Mackay score of anterior ethmoid sinuses + 2 if nasal polyp present" greater than 7 can be reliably used for diagnosing ECRS. This system can facilitate decision-making processes regarding the administration of oral steroids and biologics targeting type 2 inflammation prior to surgical intervention.

Histopathologic features of biologic therapy nonresponders in chronic rhinosinusitis with nasal polyposis

BACKGROUND

Biologics are effective for chronic rhinosinusitis with nasal polyposis (CRSwNP) by reducing type 2 inflammation. Nonresponders often require functional endoscopic sinus surgery (FESS) and represent a challenging population potentially due to non-type 2 pathophysiology. This study characterizes the histopathologic features of biologic nonresponders.

METHODS

A retrospective review of 257 CRSwNP patients undergoing FESS was conducted. The biologic nonresponder group included patients with prior biologic therapy who exhibited persistent symptoms and polyp burden. Those with CRSwNP not prescribed biologic therapy were selected as controls. Demographics, comorbidities, and structured histopathology consisting of 13 variables were collected.

RESULTS

Of 257 CRSwNP patients, 20 were on biologics prior to FESS. Fourteen patients (70.0%) received dupilumab, one (5.0%) received mepolizumab, one (5.0%) received omalizumab, and four (20.0%) tried multiple biologics. The mean age for the biologic nonresponder group was 45.8 years compared to 50.4 years for the controls. Nonresponders had a significantly increased incidence of reduced tissue eosinophilia, defined as <5 per high power field (55% vs. 31.2%, p = 0.044) and increased basement membrane thickening (100% vs. 78.1%, p = 0.019). The remaining 11 variables did not reach statistical significance.

CONCLUSION

Histopathologic analysis of biologic nonresponders demonstrates decreased eosinophilia and thickened basement membranes. These findings, particularly low tissue eosinophils, are consistent with a non-type 2 CRSwNP that may be recalcitrant to biologic therapies. Histopathologic analysis done in conjunction with FESS may aid clinicians in understanding response to biologic therapies in patients with CRSwNP who have persistent symptom burden necessitating FESS.

Predictors of persistent disease in biologic treated type 2 diffuse/eosinophilic chronic rhinosinusitis undergoing surgery

BACKGROUND

Biologic therapy targeting type 2 chronic rhinosinusitis with nasal polyps (CRSwNP) has greatly improved disease control but nonresponders exist in a proportion of patients in phase 3 trials and clinical practice. This study explores the serum and histologic changes in biologic treated CRSwNP that predict disease control.

METHODS

A cross-sectional study was performed of patients with CRSwNP on biologics for their asthma, who underwent endoscopic sinus surgery while on biologic therapy. At the 6-month postoperative assessment, patients with poorly controlled CRSwNP while on biologic therapy were compared to patients who were controlled. Blood and mucosal samples taken at the time of surgery 6 months prior were assessed to predict disease control.

RESULTS

A total of 37 patients were included (age 47.8 ± 12.4 years, 43.2% female). Those with poorly controlled disease had reduced tissue eosinophils (% >100 cells/high-powered field: 8.3% vs. 50.0%, p < 0.001) and increased serum neutrophils (5.2 ± 2.7 vs. 3.7 ± 1.1 × 109 cells/L, p = 0.02). Logistic regression analysis demonstrated that reduced tissue eosinophil was predictive for poorly controlled disease (OR = 0.21, 95% CI [0.05, 0.83], p = 0.03). Receiver-operating characteristic analysis showed that need for rescue systemic corticosteroid was predicted at a serum neutrophil cut-off level of 5.75 × 109 cells/L (sensitivity = 80.0%, specificity = 96.9%, AUC = 0.938, p = 0.002).

CONCLUSION

Low tissue eosinophils and increased serum neutrophils while on biologics predict for poor response in the biological treatment of with CRSwNP. A serum neutrophil level of ≥5.75 × 109 cells/L predicts for poor response to current biologic therapy.

Multivariate analysis of clinical and radiological risk factors for revision endoscopic sinus surgery in patients with chronic rhinosinusitis with nasal polyps: can phenotype predict recurrence?

OBJECTIVE

This study aimed to analyse clinical and radiological features (phenotypes) to predict revision risk after functional endoscopic sinus surgery in patients with chronic rhinosinusitis with nasal polyps.

METHOD

Phenotype characteristics of the patients with chronic rhinosinusitis with nasal polyps who underwent functional endoscopic sinus surgery were analysed retrospectively.

RESULTS

The rates of asthma, aspirin sensitivity, smoking and a positive prick test result were significantly higher in revision functional endoscopic sinus surgery cases (p < 0.001, 0.001, < 0.001 and < 0.001, respectively). Multivariate analysis demonstrated that only gender, pre-operative nasal steroid use, pre-operative systemic steroid use, intra-operative systemic steroid use and smoking were significant risk factors for revision functional endoscopic sinus surgery (p = 0.034, 0.001, 0.010, 0.007 and 0.001, respectively). In addition, only eosinophilia and aspirin sensitivity were significant risk factors for multiple revision functional endoscopic sinus surgery procedures (p = 0.043 and 0.005, odds ratio = 2.4 and 5.2).

CONCLUSION

Beyond the endotype of chronic rhinosinusitis with nasal polyps, defining clinical and radiological factors enables a valid prediction of patients at high risk of revision functional endoscopic sinus surgery.

IL-13 and IL-13-induced periostin levels are specifically decreased in patients following endoscopic sinus surgery for chronic rhinosinusitis

BACKGROUND

Type 2 (T2) inflammation plays a pathogenic role in chronic rhinosinusitis (CRS). The effects of endoscopic sinus surgery (ESS) on T2 inflammation are unknown.

OBJECTIVE

The aim of this study was to compare T2 inflammatory biomarkers from middle meatal (MM) mucus for distinguishing patients with CRS from CRS-free patients, identifying major phenotypes (CRS without nasal polyps [CRSsNP] and CRS with nasal polyps [CRSwNP]), assessing endotypic change, and establishing cross-sectional and longitudinal outcomes in patients undergoing ESS.

METHODS

MM mucus samples were collected from patients with CRSsNP and patients with CRSwNP before and 6 to 12 months after ESS and compared with samples from CRS-free control patients. T2 biomarkers were evaluated both continuously and using threshold-based definitions of T2 endotype to identify relationships with patient-reported (based on the 22-Item Sinonasal Outcomes Test and Chronic Rhinosinusitis Patient-Reported Outcomes Measure) and clinician-reported (radiographic and endoscopic) severity. Linear mixed models were developed to analyze clinical variables associated with T2 biomarker levels.

RESULTS

A total of 154 patients with CRS (89 with CRSsNP and 65 with CRSwNP) were enrolled, with a mean interval of 9 months between ESS and follow-up. An analysis of pre-ESS MM mucus samples revealed elevated levels of T2 mediators in patients with CRSwNP versus in patients with CRSsNP and CRS-free controls. Temporally stable correlations between levels of IL-13 and IL-5, levels of periostin and complement 5a, and levels of eosinophil cationic protein (ECP) and eotaxin-3 were observed. On this basis and on the basis of pathologic significance, levels of IL-13, periostin and ECP were further analyzed. After ESS, levels of IL-13 and periostin decreased significantly, whereas ECP levels remained unchanged. Across pre- and post-ESS evaluation, the T2 endotype was associated with radiographic severity but did not predict outcomes. CRSwNP status and African American race were associated with higher levels of IL-13 and periostin, whereas ECP level was higher in patients undergoing extensive surgery.

CONCLUSION

ESS decreased levels of IL-13 and periostin in the middle meatus. T2 inflammation after ESS was correlated with patient- and clinician-reported severity across phenotypes. Pre-ESS T2 inflammation did not predict post-ESS outcomes.

Interaction of eosinophilic and neutrophilic inflammation in patients with chronic rhinosinusitis

PURPOSE OF REVIEW

In the past year, the endotype of chronic rhinosinusitis (CRS) has been studied from a new perspective. Eosinophilic and neutrophilic inflammation are not independent processes in the pathogenesis of CRS. In this review, we will focus on recent research on mixed eosinophilic-neutrophilic inflammation in CRS and discuss the mechanism and potential treatments.

RECENT FINDINGS

Traditionally, patients with eosinophilic CRS (ECRS) present with severe clinical manifestations, comorbidities, and a higher recurrence rate. Recent studies have found that approximately 40% of patients with ECRS present with neutrophilic infiltration, while patients with predominantly eosinophilic infiltration along with neutrophilic inflammation present with more complex inflammation, clinical manifestations and exhibit refractory characteristics.

SUMMARY

The complex inflammatory profile and refractory clinical characteristics of mixed eosinophilic-neutrophilic inflammation in CRS are current challenges for clinicians. We summarize the features of eosinophilic and neutrophilic inflammation and current studies on the mechanisms of mixed eosinophilic-neutrophilic inflammation and suggest potentially effective therapeutic methods. We hope that this review will help with determining precise treatment options for patients.

Type 2 Biomarkers for the Indication and Response to Biologics in CRSwNP

PURPOSE OF REVIEW

Three biologics targeting type 2 inflammation have been approved for the treatment of severe and uncontrolled chronic rhinosinusitis with nasal polyps (CRSwNP). Nevertheless, around 40-60% of patients do not respond well to these biological treatments. Selecting appropriate patients is crucial to improve treatment outcome of biologics. This review summarizes the literature data on type 2 biomarkers, with a specific focus on the indication to biologics for severe CRSwNP.

RECENT FINDINGS

No consensus has been reached on how to define mucosal type 2 inflammation in CRSwNP. Clinical markers (e.g., 22-item Sino-nasal Outcome Test (SNOT-22) score, Lund-Mackay CT score (LMS), ethmoid/maxillary sinus CT score, and CT-radiomics), nasal secretion biomarkers (e.g., eosinophil cationic protein and interleukin-5), blood and nasal cytology eosinophil counts, and nasal swab eosinophil peroxidase activity have been reported to be associated with type 2 inflammation in CRSwNP. The time duration since the last surgery, SNOT-22 score at 1 week of treatment, and baseline serum osteoprotegerin levels might indicate the response to dupilumab. LMS and asthma control test scores were found to have moderate predictive value for acceptable improvement after 24-week treatment of omalizumab. High blood eosinophil levels at baseline were associated with treatment response to mepolizumab and benralizumab. Although several clinical and biological markers might be associated with type 2 inflammation and response to biologics in patients with CRSwNP, their validity requires further investigation. Identifying clinically applicable biomarkers for biologic treatment holds significant promise for advancing personalized approaches to biologics and optimizing treatment outcomes for patients with CRSwNP.

Diverse Endotypes of Chronic Rhinosinusitis and Clinical Implications

Chronic rhinosinusitis (CRS) is a highly heterogeneous disease characterized by inflammation in the nasal and sinus mucosa. The CRS phenotypes, based on the presence or absence of nasal polyps, are known as CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). However, this classification has limitations in fully capturing the mechanisms and clinical manifestations of CRS. To address the heterogeneity of CRS, there has been a growing focus on classifying the condition into distinct endotypes. Endotype classification involves grouping patients based on specific molecular, immunological, and clinical characteristics, allowing for more personalized and targeted treatment approaches.This review delves into the current state of endotype classifications for CRS. It explores the role of geographic factors, microbiome, and subphenotype in shaping different endotypes. Additionally, the review examines how various clinical features are associated with specific endotypes, providing valuable insights into tailoring treatment options for better outcomes and transitions between different endotypes.Overall, this review offers a comprehensive and up-to-date perspective on the intricate realm of CRS endotype classifications. By unraveling the molecular and clinical intricacies, this review lays the foundation for more precise, effective, and individualized treatment strategies in the management of CRS.

Can EPOS2020 criteria of type 2 inflammation be applied to Asian patients with chronic rhinosinusitis?

BACKGROUND

There is a large diversity of mucosal immunologic chronic rhinosinusitis with nasal polyps (CRSwNP) endotypes across Western and Asian patient populations.

OBJECTIVES

The objective of the study was whether the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) 2020 criteria for type 2 inflammation are appropriate for biological use in CRSwNP patients.

METHODS

A total of 207 participants are enrolled for the study. Retrospective evaluations of the tissues taken during surgery and the patients' clinical features were performed. We investigated whether the criteria described in the EPOS2020 guideline were appropriate based on the criteria for type 2 inflammation identified based on prior studies using receiver-operating characteristic (ROC) analyses.

RESULTS

The EPOS 2020 criteria are also shown to be an insufficient evaluation approach with low specificity (area under curve [AUC] = 0.645, specificity 8.4%). The authors created a novel scoring method using the total serum IgE level, blood eosinophil percentage, and tissue eosinophil percentage. This novel scoring system (AUC = 0.862, p < .001) fared better in ROC analyses than the EPOS 2020 criteria (AUC = 0.645) and Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis scoring system (AUC = 0.647).

CONCLUSIONS AND SIGNIFICANCE

A novel standard for type 2 inflammation in Asian CRSwNP patients must be established, as the EPOS 2020 criteria do not appear to be sufficient.

Use of peripheral blood eosinophils to guide post-operative glucocorticoid therapy in patients with chronic rhinosinusitis with nasal polyps: a randomised, controlled trial

OBJECTIVE

This study aimed to explore the utility of the eosinophil percentage in peripheral blood for guiding post-operative glucocorticoid therapy in patients with chronic rhinosinusitis with nasal polyps.

METHODS

Forty-four patients with chronic rhinosinusitis with nasal polyps underwent functional endoscopic sinus surgery and were randomly divided into two groups. Patients in the standard treatment group used oral and nasal spray glucocorticoids. In the biomarker treatment group, patients with peripheral blood eosinophil percentage values less than 3.05 per cent did not receive glucocorticoid treatment, whereas patients with values 3.05 per cent or above were part of the standard treatment group. Visual Analogue Scale, Sino-Nasal Outcome Test-22 scores, endoscopic Lund-Kennedy scores, eosinophils, interleukin-5 and eosinophil cationic protein in peripheral blood, and nasal secretions were measured.

RESULTS

After functional endoscopic sinus surgery, the Visual Analogue Scale, Sino-Nasal Outcome Test-22 and Lund-Kennedy scores were significantly reduced in both groups; there were no significant differences in those indicators between the groups during the three follow-up visits.

CONCLUSION

Peripheral blood eosinophil percentage offers a potential biomarker to guide post-operative glucocorticoid therapy in patients with chronic rhinosinusitis with nasal polyps.

Macroarray expression analysis of cytokines and prostaglandin metabolism-related genes in chronic rhinosinusitis

Background

Chronic rhinosinusitis (CRS) can be divided into endotypes by functional or pathophysiologic findings.

Objective

The aim of this study was to analyze the expression of cytokines, prostaglandin (PG) synthases, and their receptors related to the pathogenesis of CRS, especially those contributing to nasal polyp (NP) formation.

Methods

NPs and uncinate tissue (UT) samples were collected from 90 patients who underwent endoscopic sinus surgery. They included 75 patients with CRS (including 45 with eosinophilic CRS [eCRS] and 30 with non-eCRS) and 15 patients without CRS. A total of 30 genes were selected for our original DNA array plate to analyze the levels of expression of 10 cytokines (IFN-γ, IL-4, IL-5, IL-10, IL-13, IL-17A, IL-22, IL-25, IL-33, and TSLP), 4 prostaglandin synthases (prostaglandin D2 [PGD2] synthase, prostaglandin E2 synthase, COX-1, and COX-2), and their 16 receptors. Clustering analysis was performed according to the expression results, and clinical findings of patients from each cluster were investigated.

Results

The samples could be divided into 3 clusters. Cluster 1 showed elevated levels of expression of IL4, IL5, IL13, TSLP, IL1RL1 (ST2 [an IL-33 receptor]), HPGDS, and GPR44 (CRTH2, a PGD2 receptor); cluster 2 showed elevated levels of expression of IL17A and PTGES; and cluster 3 showed an elevated level of expression of IL25. Regarding clinical features, the main characteristics of each cluster were as follows: NPs from patients with eCRS for cluster 1, NPs and/or UT samples from patients with non-eCRS for cluster 2, and UTs from patients with non-CRS for cluster 3.

Conclusion

The results suggest that there are associations between type 2 inflammation/PGD2 and eCRS and also between type 3 inflammation/prostaglandin E2 and non-eCRS.

Innovative treatments for severe uncontrolled chronic rhinosinusitis with nasal polyps

INTRODUCTION

In recent years, endotypes of chronic rhinosinusitis (CRS) based on the underlying immune mechanisms provided a better understanding of this heterogeneous disease and are frequently applied in diagnosis and treatment.

AREAS COVERED

In this manuscript, we aim to review novel treatment approaches for this often uncontrolled disease and highlight endotype-driven medical algorithms that could be beneficial in daily clinical practice.

EXPERT OPINION

With the development of endotyping and the mucosal inflammatory concept, several type 2-targeted biologics and surgical options are nowadays available for treating CRS. However, a better understanding based on clinical trials and real-life experience in daily practice is needed to optimize patient selection, biological drug selection, treatment duration, prediction, and long-term follow-up strategies. Indirect comparison analysis suggested that dupilumab might be the most effective biologic for treating CRS with nasal polyps, but the role and timing of surgery remain unclear. More real-life studies and comparative trials are needed for the optimal integration of biologics into clinical pathways in combination with established treatment approaches such as nasal and oral glucocorticosteroids and adequate surgery to provide long-term perspectives.

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.

Involvement of CD40-CD40L and ICOS-ICOSL in the development of chronic rhinosinusitis by targeting eosinophils

Background

Chronic rhinosinusitis (CRS), whose prevalence and pathogenesis are age-related, is characterized by nasal tissue eosinophil infiltration. CD40-CD40 ligand (CD40L) pathway involves in the eosinophil-mediated inflammation, and inducible co-stimulator (ICOS)-ICOS ligand (ICOSL) signal can strengthen CD40-CD40L interaction. Whether CD40-CD40L and ICOS-ICOSL have a role in the development of CRS remains unknown.

Objectives

The aim of this study is to investigate the association of CD40-CD40L and ICOS-ICOSL expression with CRS and underlying mechanisms.

Methods

Immunohistology detected the expression of CD40, CD40L, ICOS, and ICOSL. Immunofluorescence was performed to evaluate the co-localizations of CD40 or ICOSL with eosinophils. Correlations between CD40-CD40L and ICOS-ICOSL as well as clinical parameters were analyzed. Flow cytometry was used to explore the activation of eosinophils by CD69 expression and the CD40 and ICOSL expression on eosinophils.

Results

Compared with the non-eCRS subset, ECRS (eosinophilic CRS) subset showed significantly increased CD40, ICOS, and ICOSL expression. The CD40, CD40L, ICOS, and ICOSL expressions were all positively correlated with eosinophil infiltration in nasal tissues. CD40 and ICOSL were mainly expressed on eosinophils. ICOS expression was significantly correlated with the expression of CD40-CD40L, whereas ICOSL expression was correlated with CD40 expression. ICOS-ICOSL expression positively correlated with blood eosinophils count and disease severity. rhCD40L and rhICOS significantly enhanced the activation of eosinophils from patients with ECRS. Tumor necrosis factor-α (TNF-α) and interleukin-5 (IL-5) obviously upregulated CD40 expression on eosinophils, which was significantly inhibited by the p38 mitogen-activated protein kinase (MAPK) inhibitor.

Conclusions

Increased CD40-CD40L and ICOS-ICOSL expressions in nasal tissues are linked to eosinophils infiltration and disease severity of CRS. CD40-CD40L and ICOS-ICOSL signals enhance eosinophils activation of ECRS. TNF-α and IL-5 regulate eosinophils function by increasing CD40 expression partly via p38 MAPK activation in patients with CRS.

Eosinophilic Airway Diseases: From Pathophysiological Mechanisms to Clinical Practice

Eosinophils play a key role in airway inflammation in many diseases, such as allergic and non-allergic asthma, chronic rhinosinusitis with nasal polyps, and chronic obstructive pulmonary disease. In these chronic disabling conditions, eosinophils contribute to tissue damage, repair, remodeling, and disease persistence through the production a variety of mediators. With the introduction of biological drugs for the treatment of these respiratory diseases, the classification of patients based on clinical characteristics (phenotype) and pathobiological mechanisms (endotype) has become mandatory. This need is particularly evident in severe asthma, where, despite the great scientific efforts to understand the immunological pathways underlying clinical phenotypes, the identification of specific biomarkers defining endotypes or predicting pharmacological response remains unsatisfied. In addition, a significant heterogeneity also exists among patients with other airway diseases. In this review, we describe some of the immunological differences in eosinophilic airway inflammation associated with severe asthma and other airway diseases and how these factors might influence the clinical presentation, with the aim of clarifying when eosinophils play a key pathogenic role and, therefore, represent the preferred therapeutic target.

Sinonasal Stent Coated with Sustained-Release Varnish of Mometasone Furoate Inhibits Pro-Inflammatory Cytokine Release from Macrophages: An In Vitro Study

The aim of the study was to develop a sustained-release varnish (SRV) containing mometasone furoate (MMF) for sinonasal stents (SNS) to reduce mucosa inflammation in the sinonasal cavity. The SNS' segments coated with SRV-MMF or an SRV-placebo were incubated daily in a fresh DMEM at 37 °C for 20 days. The immunosuppressive activity of the collected DMEM supernatants was tested on the ability of mouse RAW 264.7 macrophages to secrete the cytokines' tumor necrosis factor α (TNFα) and interleukin (IL)-10 and IL-6 in response to lipopolysaccharide (LPS). The cytokine levels were determined by respective Enzyme-Linked Immunosorbent Assays (ELISAs). We found that the daily amount of MMF released from the coated SNS was sufficient to significantly inhibit LPS-induced IL-6 and IL-10 secretion from the macrophages up to days 14 and 17, respectively. SRV-MMF had, however, only a mild inhibitory effect on LPS-induced TNFα secretion as compared to the SRV-placebo-coated SNS. In conclusion, the coating of SNS with SRV-MMF provides a sustained delivery of MMF for at least 2 weeks, maintaining a level sufficient for inhibiting pro-inflammatory cytokine release. This technological platform is, therefore, expected to provide anti-inflammatory benefits during the postoperative healing period and may play a significant role in the future treatment of chronic rhinosinusitis.

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.

Translating the biology of β common receptor-engaging cytokines into clinical medicine

The family of cytokines that comprises IL-3, IL-5, and GM-CSF was discovered over 30 years ago, and their biological activities and resulting impact in clinical medicine has continued to expand ever since. Originally identified as bone marrow growth factors capable of acting on hemopoietic progenitor cells to induce their proliferation and differentiation into mature blood cells, these cytokines are also recognized as key mediators of inflammation and the pathobiology of diverse immunologic diseases. This increased understanding of the functional repertoire of IL-3, IL-5, and GM-CSF has led to an explosion of interest in modulating their functions for clinical management. Key to the successful clinical translation of this knowledge is the recognition that these cytokines act by engaging distinct dimeric receptors and that they share a common signaling subunit called β-common or βc. The structural determination of how IL-3, IL-5, and GM-CSF interact with their receptors and linking this to their differential biological functions on effector cells has unveiled new paradigms of cell signaling. This knowledge has paved the way for novel mAbs and other molecules as selective or pan inhibitors for use in different clinical settings.

Persistent discharge or edema after endoscopic sinus surgery in patients with chronic rhinosinusitis is associated with a type 1 or 3 endotype

BACKGROUND

Patients with chronic rhinosinusitis (CRS) may have persistence of polyps, discharge, or edema after endoscopic sinus surgery (ESS). Inflammation in CRS can be classified into three endotypes, with the presence of polyps associated with the type 2 endotype. Here, we evaluate the endotypic underpinnings of discharge or edema without polyps after ESS.

METHODS

At a visit 6-12 months post ESS, patients underwent endoscopy and completed the CRS-PRO and SNOT-22. Luminex analysis of middle meatal mucus obtained at that visit was performed for IFN-γ, ECP, and IL-17a. Type 1, 2, and 3 endotypes were defined as greater than the 90th percentile expression of each marker, respectively, in controls. Wilcoxon rank-sum and chi-squared tests were used to compare cytokine levels and endotype prevalence between those with and without endoscopic findings.

RESULTS

A total of 122 CRS patients completed a clinical exam (median: 8.2 months post ESS). Of the 122 patients, 107 did not have polyps on endoscopy. Of these 107 patients, 48 had discharge, 44 had edema, and 46 had neither discharge nor edema. Compared with those patients without any findings, patients with discharge or edema reported significantly worse severity as measured by CRS-PRO (10.5 vs. 7.0, p = 0.009; 12.0 vs. 7.0, p < 0.001; respectively), and had higher post-ESS IFN-γ, ECP, and IL-17a. Patients with discharge had higher prevalence of only T1 and T3 endotypes, while patients with edema had higher prevalence of only the T3 endotype.

CONCLUSIONS

Post-ESS discharge or edema in the absence of polyps was associated with higher patient-reported outcome severity and was more strongly associated with type 1 or 3 inflammation.

Use of intraoperative frontal sinus mometasone-eluting stents decreased interleukin 5 and interleukin 13 in patients with chronic rhinosinusitis with nasal polyps

BACKGROUND

Mometasone-eluting stents (MES) have demonstrated improvement in short-term endoscopic outcomes and reduce short- to medium-term rescue interventions. Their effect on the local inflammatory environment, longer-term patient-reported outcomes, and radiographic severity have not been studied.

METHODS

Middle meatal mucus and validated measures of disease severity were collected before and 6 to 12 months after endoscopic surgery in 52 patients with chronic rhinosinusitis with nasal polyps (CRSwNPs). Operative findings, type 2 mediator concentrations, intraoperative variables, and disease severity measures were compared between those who did and those who did not receive intraoperative frontal MES.

RESULTS

A total of 52 patients with CRSwNPs were studied; 33 received frontal MES and were compared with 19 who did not. Pre-endoscopic sinus surgery (ESS) middle meatus (MM) interleukin (IL) 13 and eosinophil cationic protein (ECP) were higher in the stented group (p < 0.05), but pre-ESS clinical measures of disease severity were similar as were surgical extent and post-ESS medical management. Intraoperative eosinophilic mucin was more frequent in the stented group (58% vs 11%, p = 0.001). IL-5 (p < 0.05) and IL-13 (p < 0.001) decreased post-ESS in the stented group, but this was not observed in the nonstented group. Post-ESS IL-4 and IL-13 were higher in the nonstented vs stented group (p < 0.05 for both).

CONCLUSION

Although patients who received intraoperative frontal MES had significantly higher pre-ESS MM IL-13 and ECP, patients who received frontal MES had lower concentrations of IL-4 and IL-13 than those who did not at a median of 8 months post-ESS. However, these changes did not correspond to significantly different measures of symptomatic or radiographic disease severity.

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.

Endotyping of nasal polyps in a multiracial Asian population

Background: Chronic rhinosinusitis is a heterogenous disease with variation in the endotypes of nasal polyps, with type 2 inflammation being more prevalent in Caucasian populations whereas Chinese populations are more heterogenous. We aim to describe the variation in endotypes for patients with chronic rhinosinusitis with nasal polyposis in our unique multiracial population. Methodology: Demographic, clinical and structured histopathological data of 66 patients who underwent sinus surgery for nasal polyposis were evaluated retrospectively. Results: 54.6% had eosinophilic disease, and 45.4% had non-eosinophilic disease with no significant demographic differences between the 2 populations. There were significantly higher peripheral eosinophil levels in patients with eosinophil-predominant inflammation on tissue histology (mean absolute eosinophil count 0.59 ± 0.18 x 109) compared with non-eosinophilic disease (mean absolute eosinophil count 0.24 ± 0.11 x 109). Structured histopathological reporting revealed that patients with eosinophilic disease had higher degree of inflammation and eosinophil aggregates. Conclusions: Our population is shown to have a slight preponderance toward eosinophilic disease, however the Chinese majority tended to have non-eosinophilic disease. Serum eosinophilia and the presence of asthma seems to correlate well with tissue eosinophilia, which can potentially be utilised as markers of type 2 inflammatory disease.

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

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

Conventional and pathogenic Th2 cells in inflammation, tissue repair, and fibrosis

Type 2 helper T (Th2) cells, a subset of CD4⁺ T cells, play an important role in the host defense against pathogens and allergens by producing Th2 cytokines, such as interleukin-4 (IL-4), IL-5, and IL-13, to trigger inflammatory responses. Emerging evidence reveals that Th2 cells also contribute to the repair of injured tissues after inflammatory reactions. However, when the tissue repair process becomes chronic, excessive, or uncontrolled, pathological fibrosis is induced, leading to organ failure and death. Thus, proper control of Th2 cells is needed for complete tissue repair without the induction of fibrosis. Recently, the existence of pathogenic Th2 (Tpath2) cells has been revealed. Tpath2 cells produce large amounts of Th2 cytokines and induce type 2 inflammation when activated by antigen exposure or tissue injury. In recent studies, Tpath2 cells are suggested to play a central role in the induction of type 2 inflammation whereas the role of Tpath2 cells in tissue repair and fibrosis has been less reported in comparison to conventional Th2 cells. In this review, we discuss the roles of conventional Th2 cells and pathogenic Th2 cells in the sequence of tissue inflammation, repair, and fibrosis.

Prognostic factors for polyp recurrence in chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps is frequently managed with endoscopic sinus surgery (ESS). Prior studies describe individual clinical variables and eosinophil density measures as prognostic for polyp recurrence (PR). However, the relative prognostic significance of these have not been extensively investigated.

OBJECTIVES

We sought to evaluate the impact of PR on measures of disease severity post-ESS and quantify the prognostic value of various clinical variables and biomarkers.

METHODS

Ninety-four patients with chronic rhinosinusitis with nasal polyps and prospectively biobanked polyp homogenates at the time of ESS were recruited 2 to 5 years post-ESS. Patients were evaluated with patient-reported outcome measures and endoscopic and radiographic scoring pre- and post-ESS. Biomarkers in polyp homogenates were measured with ELISA and Luminex. Relaxed least absolute shrinkage and selection operator regression optimized predictive clinical, biomarker, and combined models. Model performance was assessed using receiver-operating characteristic curve and random forest analysis.

RESULTS

PR was found in 39.4% of patients, despite significant improvements in modified Lund-Mackay (MLM) radiographic and 22-item Sinonasal Outcomes Test scores (both P < .0001). PR was significantly associated with worse post-ESS MLM, modified Lund-Kennedy, and 22-item Sinonasal Outcomes Test scores. Relaxed least absolute shrinkage and selection operator identified 2 clinical predictors (area under the curve = 0.79) and 3 biomarkers (area under the curve = 0.78) that were prognostic for PR. When combined, the model incorporating these pre-ESS factors: MLM, asthma, eosinophil cationic protein, anti-double-stranded DNA IgG, and IL-5 improved PR predictive accuracy to area under the curve of 0.89. Random forest analysis identified and validated each of the 5 variables as the strongest predictors of PR.

CONCLUSIONS

PR had strong associations with patient-reported outcome measures, endoscopic and radiographic severity. A combined model comprised of eosinophil cationic protein, IL-5, pre-ESS MLM, asthma, and anti-double-stranded DNA IgG could accurately predict PR.

Characterization of the Notch pathway in nasal polyps of patients with chronic rhinosinusitis: A pilot study

Chronic rhinosinusitis with nasal polyps is a widespread pathology characterized by persistent inflammation of nasal and paranasal mucosa. Although it represents one of the most frequent diseases of the nasal cavities, its etiology is still not completely elucidated. There is evidence suggesting that the Notch signaling, a highly conserved intercellular pathway known to regulate many cellular processes, including inflammation, is implicated in nasal polyps formation. The purpose of this study was to investigate the expression of genes of the Notch pathway in nasal polyps from patients with chronic rhinosinusitis. Nasal polyps and adjacent mucosa tissue were obtained from 10 patients. RNA was analyzed by quantitative reverse transcriptase-polymerase chain reaction for the expression level of (1) Notch pathway components such as receptors (NOTCH1-4), ligands (DLL4, JAGGED-1), and target genes (HEY1, 2, and HES1) and (2) genes providing information on the pathogenesis of polyposis (C-MYC and SCGB1A1) and on eosinophils content (CCL26, IL5, and SAA2). We report a Notch-driven gene expression pattern in nasal polyps which correlates with the expression of genes highly expressed in eosinophils, whose presence is an important parameter to define the pathophysiologic diversity characterizing nasal polyps. Taken together, our results suggest a role for Notch signaling in the pathophysiology of polyposis. Further studies are needed to elucidate the role of Notch in nasal polyps formation and to establish whether it could represent a novel therapeutic target for this pathology.

Efficacy of an oral CRTH2 antagonist (AZD1981) in the treatment of chronic rhinosinusitis with nasal polyps in adults: A randomized controlled clinical trial

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease of the upper airways. AZD1981 is a selective antagonist of chemoattractant receptor-homologous molecule expressed on T helper type 2 and other type 2 cells, including innate lymphoid cells type 2, eosinophils, and basophils.

OBJECTIVE

To evaluate the efficacy of AZD1981 in reducing nasal polyp size when added to intranasal corticosteroids in adult patients with CRSwNP.

METHODS

Eighty-one subjects (18-70 years of age) with CRSwNP were recruited and screened for trial eligibility from allergy and otolaryngology clinics from a single tertiary care site between June 2016 and August 2019. Eligible patients were randomized in a double-blind fashion to receive either AZD1981 (n = 22) or placebo (n = 21) orally three times a day for 12 weeks, added to intranasal corticosteroids. The primary endpoint was a change in nasal polyp score (NPS) at 12 weeks. Secondary endpoints included improvement in sinus computed tomography using Lund Mackay scoring, symptoms using visual analog scale, quality of life using Sino Nasal Outcome Test-22, and the Brief Smell Identification Test.

RESULTS

Forty-three patients met the inclusion criteria and were enrolled. At 12 weeks, there was no difference in NPS change in the AZD1981 arm (mean 0, standard error 0.34, n = 15) compared with placebo (mean 0.20, standard error 0.36, n = 17); mean difference -0.20 (95% confidence interval: -1.21, 0.81; p = .69). No significant differences were observed for Lund Mackay score, symptoms, quality of life, or smell test. AZD1981 was well tolerated except for one case of hypersensitivity reaction.

CONCLUSION

In patients with CRSwNP, the addition of AZD1981 to intranasal corticosteroids did not change nasal polyp size, radiographic scores, symptoms, or disease-specific quality of life.

Management of Patients with Severe Asthma and Chronic Rhinosinusitis with Nasal Polyps: A Multidisciplinary Shared Approach

Chronic rhinosinusitis (CRS) is one of the most frequent comorbidities associated with asthma and it contributes to an amplified global disease burden in asthmatics. CRS prevalence is much higher in asthmatic patients compared to the general population and it is more frequently related to severe asthma, especially in presence of nasal polyps (chronic rhinosinusitis with nasal polyps, CRSwNP). Moreover, asthma exacerbation has a higher occurrence in CRSwNP. From a pathologic point of view, CRS and asthma share similar and connected mechanisms (e.g., type-2 inflammation). A multidisciplinary approach represents a crucial aspect for the optimal management of patients with concomitant asthma and CRSwNP and improvement of patient quality of life. An Italian panel of clinicians with different clinical expertise (pulmonologists, ear, nose and throat specialists, immunologists and allergy physicians) identified three different profiles of patients with coexisting asthma and nasal symptoms and discussed the specific tracks to guide a comprehensive approach to their diagnostic and therapeutic management. Currently available biological agents for the treatment of severe asthma act either on eosinophil-centered signaling network or type-2 inflammation, resulting to be effective also in CRSwNP and representing a valid option for patients with concomitant conditions.

The Role of Proprotein Convertases in Upper Airway Remodeling

Chronic rhinosinusitis (CRS) is a multifactorial, heterogeneous disease characterized by persistent inflammation of the sinonasal mucosa and tissue remodeling, which can include basal/progenitor cell hyperplasia, goblet cell hyperplasia, squamous cell metaplasia, loss or dysfunction of ciliated cells, and increased matrix deposition. Repeated injuries can stimulate airway epithelial cells to produce inflammatory mediators that activate epithelial cells, immune cells, or the epithelial-mesenchymal trophic unit. This persistent inflammation can consequently induce aberrant tissue remodeling. However, the molecular mechanisms driving disease within the different molecular CRS subtypes remain inadequately characterized. Numerous secreted and cell surface proteins relevant to airway inflammation and remodeling are initially synthesized as inactive precursor proteins, including growth/differentiation factors and their associated receptors, enzymes, adhesion molecules, neuropeptides, and peptide hormones. Therefore, these precursor proteins require post-translational cleavage by proprotein convertases (PCs) to become fully functional. In this review, we summarize the roles of PCs in CRS-associated tissue remodeling and discuss the therapeutic potential of targeting PCs for CRS treatment.

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

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

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.

Using machine learning for the personalised prediction of revision endoscopic sinus surgery

BACKGROUND

Revision endoscopic sinus surgery (ESS) is often considered for chronic rhinosinusitis (CRS) if maximal conservative treatment and baseline ESS prove insufficient. Emerging research outlines the risk factors of revision ESS. However, accurately predicting revision ESS at the individual level remains uncertain. This study aims to examine the prediction accuracy of revision ESS and to identify the effects of risk factors at the individual level.

METHODS

We collected demographic and clinical variables from the electronic health records of 767 surgical CRS patients ≥16 years of age. Revision ESS was performed on 111 (14.5%) patients. The prediction accuracy of revision ESS was examined by training and validating different machine learning models, while the effects of variables were analysed using the Shapley values and partial dependence plots.

RESULTS

The logistic regression, gradient boosting and random forest classifiers performed similarly in predicting revision ESS. Area under the receiving operating characteristic curve (AUROC) values were 0.744, 0.741 and 0.730, respectively, using data collected from the baseline visit until six months after baseline ESS. The length of time during which data were collected improved the prediction performance. For data collection times of 0, 3, 6 and 12 months after baseline ESS, AUROC values for the logistic regression were 0.682, 0.715, 0.744 and 0.784, respectively. The number of visits before or after baseline ESS, the number of days from the baseline visit to the baseline ESS, patient age, CRS with nasal polyps (CRSwNP), asthma, non-steroidal anti-inflammatory drug exacerbated respiratory disease and immunodeficiency or suspicion of it all associated with revision ESS. Patient age and number of visits before baseline ESS carried non-linear effects for predictions.

CONCLUSIONS

Intelligent data analysis identified important predictors of revision ESS at the individual level, such as the frequency of clinical visits, patient age, Type 2 high diseases and immunodeficiency or a suspicion of it.

Clinical and laboratory features for various criteria of eosinophilic chronic rhinosinusitis: a systematic review and meta-analysis

Objectives: To evaluate the differences in clinical and laboratory features between eosinophilic chronic rhinosinusitis (ECRS) and non-ECRS and to compare the diagnostic criteria for ECRS.Methods: We compared clinical features and/or laboratory findings classified as ECRS and non-ECRS according to various diagnostic criteria (histological and clinical criteria). In addition, we analyzed studies to compare endoscopic findings, symptom scores, laboratory findings, and computed tomography (CT) findings between ECRS and non-ECRS. Results: Our search included 55 studies with 6,143 patients. As a result of comparing clinical features and/or laboratory criteria with histological criteria, there were no significant differences regarding nasal symptom scores and CT scores according to criteria. Serum eosinophil levels showed differences according to criteria, however, ECRS were higher serum eosinophil levels than non-ECRS in all criteria. In the case of olfactory dysfunction, JESREC and tissue eosinophilia (

Chinese Central Compartment Atopic Disease: The Clinical Characteristics and Cellular Endotypes Based on Whole-Slide Imaging

Purpose

Histopathologic characterizations of central compartment atopic disease (CCAD) by whole-slide imaging remains lacking. We aim to study clinical presentations and cellular endotyping diagnosis of Chinese CCAD using artificial intelligence (AI).

Methods

A total of 72 patients diagnosed with chronic rhinosinusitis with nasal polyps (CRSwNP) were enrolled. CCAD was defined by positive result of serology specific IgE, endoscopic and radiological findings. The aeroallergen sensitization status, endoscopic results, radiological findings, and symptoms were evaluated and compared between patients with CCAD (n=14), eosinophilic CRSwNP (ENP, n=32) and non-eosinophilic CRSwNP (NENP, n=26). The cellular endotypes including eosinophils, neutrophils, lymphocytes, and plasma cells were analyzed by the AI chronic rhinosinusitis evaluation platform 2.0.

Results

CCAD was most common in male (71.43%). The positive rate of aeroallergen in patients with CCAD is 100%, which is much higher than those in patients with ENP (40.63%) and NENP (23.08%). Allergic rhinitis incidence was found to be 57.14% in Chinese CCAD subjects, which is obviously higher when compared with those in patients with ENP (21.88%) or NENP (0.00%). The presence of asthma was not significantly different between groups. Chinese CCAD population demonstrated mild symptoms and lower endoscopic and radiological scores than those in patients with ENP and NENP. For cellular endotypes in CCAD subjects, the median of eosinophils, neutrophils, lymphocytes, and plasma cells was 26.55%, 0.49%, 60.85%, and 7.33%, respectively. The proportion of eosinophils in nasal tissue and peripheral blood mononuclear cells from the CCAD group is between the proportions in those patients with ENP and NENP.

Conclusion

Chinese CCAD was associated with aeroallergen sensitivity, and displayed an eosinophil-dominant inflammatory pattern. Thus, proper management with allergy control and topical steroids could be recommended for CCAD treatment.

Classification of eCRS: Based on disease outcome or normal range?: Comment on Toro et al

Undoubtedly, there is a lack of unanimous histopathologic criteria to classify eosinophilic chronic rhinosinusitis (eCRS) worldwide. We read with great interest the recent constructive systematic review by Toro et al.(1). The authors stretched out the current knowledge on the methods of classifying eCRS to determine an optimal cut-off point. While the authors are to be congratulated for their comprehensive overview, a point regarding the disease recurrence as the most relevant parameter to divide eosinophilic and noneosinophilic inflammation in chronic rhinosinusitis (CRS) should be discussed. In order to contribute to an evidence-based standardization of cut-off point to classify eCRS, we would like to share our considerations and approaches in this comment.

Nitric oxide synthase-2 (CCTTT)n polymorphism is associated with local gene expression and clinical manifestations in patients with chronic rhinosinusitis

Introduction

Nitric oxide (NO) is synthesized through NO synthase (NOS). The proximal NOS2 gene promoter contains the pentanucleotide CCTTT repeat polymorphism. We examined whether CCTTT repeats are associated with NOS2 expression in the sinonasal tissues and clinical manifestations in patients with chronic rhinosinusitis.

Methods

Mucosal specimens were obtained from the ethmoid sinus and inferior turbinate of 30 eosinophilic chronic rhinosinusitis (ECRS) and 28 non-ECRS patients. CCTTT repeats were classified into short alleles (S), with less than or equal to 14, and long alleles (L), with more than 14. The subjects were classified into the L/S + L/L and S/S groups.

Results

In ECRS, the NOS2 mRNA levels of the ethmoid sinus mucosa were significantly higher in the L/S + L/L group than in the S/S group (median, 1.66 and 0.77, respectively). On the ther hand, ECRS patients showed no significant difference in the NOS2 mRNA level of the inferior turbinate between the L/S + L/L group and the S/S group (median, 0.63 and 0.88, respectively). In ECRS, preoperative SNOT-22 were significantly higher in the L/S + L/L group than in the S/S group, whereas the former group showed a lower postoperative recurrence risk.

Conclusion

CCTTT repeat polymorphism in the NOS2 promotor gene may be a useful indicator to evaluate ECRS severity and prognosis.

Expert Opinion on Biological Treatment of Chronic Rhinosinusitis with Nasal Polyps in the Gulf Region

Chronic rhinosinusitis (CRS) is defined as the inflammation of nose and paranasal sinuses, affecting the patients' quality of life and productivity. Chronic rhinosinusitis with nasal polyps (CRSwNP) is a principal clinical entity confirmed by the existence of chronic sinonasal inflammation and is characterized by anterior or posterior rhinorrhea, nasal congestion, hyposmia and/or facial pressure or facial pain. Several epidemiologic studies have revealed wide variations in the incidence of CRS among regions globally ranging from 4.6% to 12%. The Gulf countries are also witnessing an unprecedented burden of CRSwNP. According to the current clinical guidelines, glucocorticosteroids and antibiotics are the principal pharmacotherapeutic approaches. Endoscopic sinus surgery is recommended for those who have failed maximal pharmacotherapy. Recently, biologics are considered as an alternative best approach due to the complications associated with medical therapy and surgery. However, precise data on the clinical position of biologic agents in the management of CRSwNP in the Gulf region is not available. The present review article addresses the current diagnostic and management approaches for CRSwNP and also emphasizes the role of emerging biologics in the current treatment strategies for CRSwNP in the Gulf region. Further, a consensus protocol was convened to rationalize the guideline recommendations, strategize the best practices with biologics, and develop clinical practice guidelines for all primary-care specialists in the Gulf region. The consensus-based report will be a useful reference tool for primary-care physicians in primary-healthcare settings, regarding the appropriate time for the initiation of biological treatment in the Gulf region.

Dupilumab efficacy in chronic rhinosinusitis with nasal polyps from SINUS-52 is unaffected by eosinophilic status

Background

The human monoclonal antibody dupilumab blocks interleukin (IL)‐4 andIL‐13, key and central drivers of type 2 inflammation. Dupilumab, on background mometasone furoate nasal spray (MFNS), improved outcomes in the phase III SINUS‐52 study (NCT02898454) in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). This posthoc analysis of SINUS‐52 examined whether eosinophilic status of CRSwNP was a predictor of dupilumab efficacy.

Methods

Patients were randomized 1:1:1 to dupilumab 300 mg every 2 weeks (q2w) until week 52; dupilumab 300 mg q2w until Week 24, then 300 mg every 4 weeks until week 52; or placebo (MFNS) until week 52. Coprimary endpoints were change from baseline in nasal polyps score (NPS), nasal congestion (NC), and Lund‐Mackay score assessed by CT (LMK‐CT) at week 24. Patients (n = 438) were stratified by eosinophilic chronic rhinosinusitis (ECRS) status according to the Japanese Epidemiological Survey of Refractory Eosinophilic Rhinosinusitis algorithm.

Results

Dupilumab significantly improved NPS, NC, and LMK‐CT scores versus placebo at week 24 in all ECRS subgroups (p < 0.001), with improvements maintained or increased at week 52 (p < 0.001). There was no significant interaction between ECRS subgroup (non‐/mild or moderate/severe) and dupilumab treatment effect for all endpoints at weeks 24 and 52 (p > 0.05), except LMK‐CT at week 24 (p = 0.0275). Similar results were seen for the secondary endpoints. Dupilumab was well tolerated across all ECRS subgroups.

Conclusion

Dupilumab produced consistent improvement in symptoms of severe CRSwNP irrespective of ECRS status. Therefore, blood eosinophil level may not be a suitable biomarker for dupilumab efficacy in CRSwNP.

Advances in chronic rhinosinusitis in 2020 and 2021

Major progress has been achieved in the understanding and clinical practice of chronic rhinosinusitis, with or without nasal polyps. These advances resulted in a better understanding of the pathophysiology, the distribution into subgroups, and consequently in a better management perspective using classical approaches and biologics. Pathomechanisms, endotypes and biomarkers, and finally innovative therapeutic approaches are themes especially for the more severe forms of chronic rhinosinusitis, those with uncontrolled severe nasal polyps. Biologicals against key type 2 cytokines are gaining ground in the long-term treatment approaches of often recurrent nasal polyps, and should be integrated in care pathways making use of classical and innovative treatment pathways. These areas of interest show a fast development and will profoundly change our disease management within a decade.

Inflammatory molecular endotypes of nasal polyps derived from Caucasian and Japanese populations

BACKGROUND

Emerging evidence suggests that chronic rhinosinusitis with nasal polyps (CRSwNP) is a highly heterogeneous disease with disparate inflammatory characteristics between different racial groups and geographies. Little is known currently about possible distinguishing factors underlying these inflammatory differences.

OBJECTIVE

To interrogate for differences between Caucasian and Japanese CRSwNP disease using whole transcriptome and single-cell RNA gene expression profiling of nasal polyps (NPs).

METHODS

We performed whole transcriptome RNA sequencing (RNA-seq) with endotype stratification of NPs from 8 Caucasian (residing in USA) and 9 Japanese (residing in Japan) patients. Reproducibility was confirmed by qPCR in an independent validation set of 46 Caucasian and 31 Japanese patients. Single-cell RNA-seq stratified key cell types for contributory transcriptional signatures.

RESULTS

Unsupervised clustering analysis identified two major endotypes present within both NP cohorts, which have previously been reported at the cytokine level: 1) type 2 endotype and 2) non-type 2 endotype. Importantly, there was a statistically significant difference in the proportion of these endotypes between these geographically distinct NP subgroups (p = 0.03). Droplet-based single-cell RNA sequencing further identified prominent type 2 inflammatory transcript expression: C-C motif chemokine ligand 13 (CCL13) and CCL18 in M2 macrophages, as well as cystatin SN (CST1) and CCL26 in basal, suprabasal, and secretory epithelial cells.

CONCLUSION

NPs from both racial groups harbor the same two major endotypes, which we determine are present in differing ratios between each cohort with CRSwNP disease. Distinct inflammatory and epithelial cells contribute to the type 2 inflammatory profiles observed.

Th17/Treg cells regulated by interleukin 6 in the pathogenesis of chronic rhinosinusitis with nasal polyps

PURPOSE

To be investigated whether Th17/Treg cells regulated by Interleukin-6 in the pathogenesis of chronic rhinosinusitis with nasal polyps.

METHODS

The distributions of Th17 and Treg cells in peripheral blood mononuclear cells (PBMCs) and tissues got from 46 CRSwNP patients and 14 controls were evaluated. Th17 and Treg cells and cells-related cytokines in serum were assessed in means of cytometric bead array (CBA) multiplex assays and enzyme-linked immunosorbent assays (ELISAs). Spleen cells were isolated from spleen of 20 normal BALB/c mice (male), isolated and purified with CD4 antibody immunomagnetic bead kit. CD4+ cells were divided into three groups, including TGF-β1, TGF-β1+ IL-6 and control (PBS). Treg and Th17 cells and cells related cytokines were detected by flow cytometry (FCM) after collecting spleen cells. The level of IL-10 and IL-17 in supernatant was measured by ELISA.

RESULTS

Th17/Treg ratio and the level of IL-6 in both ECRSwNP (P < 0.05) and non-ECRSwNP (P < 0.05) were significantly increased when compared with control group, these were consistent with the previous findings. Experiments in vitro suggested that the level of Th17 cells in IL-6+ TGF-β1 group was significantly increased than TGF-β1 group and control group (P < 0.05). The ratio of cells expressed RoRγt in IL-6+ TGF-β1 group was much higher than TGF-β1 group (P < 0.05).

CONCLUSION

IL-6 might regulate the function of Th17 and Treg cells and the Th17/Treg ratio and have a role in the pathogenesis of CRSwNP.

The development of the mucosal concept in chronic rhinosinusitis and its clinical implications

In the last 2 decades, an increasing understanding of pathophysiological mechanisms in chronic rhinosinusitis opened an avenue from phenotyping to endotyping, from eosinophilic inflammation to type 2 immunity, and from the "ventilation and drainage" paradigm to the mucosal concept for therapeutic considerations. With the advent of type 2 endotyping and targeted biomarkers, precise endotype-driven therapeutic options are possible including biologics and adapted surgical approaches. We here aim to focus on the complexity and heterogeneity of the features of chronic rhinosinusitis (CRS) endotypes, especially for those with nasal polyps, including its history, latest developments, clinical associations and endotype-driven solutions. In order to better manage uncontrolled severe CRS in clinical practice, medical decisions based on a profound understanding of the pathology and immunology of this heterogeneous disease, aiding a precision-medicine based approach for patient's treatment are pivotal.

CD4 + T cells in inflammatory diseases : pathogenic T-helper cells and the CD69-Myl9 system

CD4 + T cells direct immune responses against infectious microorganisms but are also involved in the pathogenesis of inflammatory diseases. In the last two to three decades, various researchers have identified and characterized several functional CD4 + T cell subsets, including T-helper 1 (Th1), Th2, Th9 and Th17 cells and regulatory T (Treg) cells. In this mini-review, we introduce the concept of pathogenic Th cells that induce inflammatory diseases with a model of disease induction by a population of pathogenic Th cells; "pathogenic Th population disease-induction model". We will focus on Th2 cells that induce allergic airway inflammation-pathogenic Th2 cells (Tpath2 cells)-and discuss the nature of Tpath2 cells that shape the pathology of chronic inflammatory diseases. Various Tpath2 cell subsets have been identified and their unique features are summarized in mouse and human systems. Second, we will discuss how Th cells migrate and are maintained in chronic inflammatory lesions. We propose a model known as the "CD69-Myl9 system". CD69 is a cell surface molecule expressed on activated T cells and interaction with its ligand myosin light chain 9 (Myl9) is required for the induction of inflammatory diseases. Myl9 molecules in the small vessels of inflamed lungs may play a crucial role in the migration of activated T cells into inflammatory lesions. Emerging evidence may provide new insight into the pathogenesis of chronic inflammatory diseases and contribute to the development of new therapeutic strategies for intractable inflammatory disorders.

Role of periostin in ECRS

Periostin, an extracelluar matrix protein belonging to the fasciclin family, has been reported to play a key role in the process of Th2-inflammation disease. As eoshinophilic chronic rhinosinusitis has a higher incident rate, studies show that periostin has participated in the process of inflammation and remodeling. This review mainly to summarize researches of periostin in ECRS and to investigate the clinical significance and expression of periostin.

The Immune System Throws Its Traps: Cells and Their Extracellular Traps in Disease and Protection

The first formal description of the microbicidal activity of extracellular traps (ETs) containing DNA occurred in neutrophils in 2004. Since then, ETs have been identified in different populations of cells involved in both innate and adaptive immune responses. Much of the knowledge has been obtained from in vitro or ex vivo studies; however, in vivo evaluations in experimental models and human biological materials have corroborated some of the results obtained. Two types of ETs have been described—suicidal and vital ETs, with or without the death of the producer cell. The studies showed that the same cell type may have more than one ETs formation mechanism and that different cells may have similar ETs formation mechanisms. ETs can act by controlling or promoting the mechanisms involved in the development and evolution of various infectious and non-infectious diseases, such as autoimmune, cardiovascular, thrombotic, and neoplastic diseases, among others. This review discusses the presence of ETs in neutrophils, macrophages, mast cells, eosinophils, basophils, plasmacytoid dendritic cells, and recent evidence of the presence of ETs in B lymphocytes, CD4+ T lymphocytes, and CD8+ T lymphocytes. Moreover, due to recently collected information, the effect of ETs on COVID-19 is also discussed.

Extrafollicular PD-1highCXCR5-CD4+ T cells participate in local immunoglobulin production in nasal polyps

BACKGROUND

Local immunoglobulin hyperproduction is observed in nasal polyps (NPs) with and without ectopic lymphoid tissues (eLTs).

OBJECTIVE

Our aim was to identify the T-cell subsets involved in local immunoglobulin production independent of eLTs in NPs.

METHODS

The localization, abundance, and phenotype of CD4⁺ T-cell subsets were studied by immunofluorescence, flow cytometry, and single-cell RNA sequencing. Purified nasal T-cell subsets were cultured with autologous peripheral naive B cells to explore their function. Programmed death ligand 1 and programmed death ligand 2 expression in NPs was investigated by immunofluorescence staining and flow cytometry.

RESULTS

Accumulation of PD-1^highCXCR5^-CD4⁺ T cells outside lymphoid aggregates was found in NPs. Nasal PD-1^highCXCR5^-CD4⁺ T cells were characterized by a unique phenotype that was related to B-cell help and tissue residency and distinct from PD-1^-/intCXCR5^- and CXCR5⁺ CD4⁺ T cells in NPs as well as PD-1^highCXCR5^highCD4⁺ follicular helper T cells in tonsils. Compared with the frequencies of PD-1^highCXCR5^-CD4⁺ T cells and their IFN-γ⁺, IL-17A⁺, and IL-21⁺ subsets in the control inferior turbinate tissues, the frequencies of these cells and their subsets were increased in both eosinophilic and noneosinophilic NPs, whereas the frequencies of the IL-4⁺ and IL-4⁺IL-21⁺ subsets were increased only in eosinophilic NPs. Nasal PD-1^highCXCR5^-CD4⁺ T cells induced immunoglobulin production from B cells in a potency comparable to that induced by tonsillar follicular helper T cells. PD-1^highCXCR5^-CD4⁺ T-cell frequencies were correlated with IgE levels in eosinophilic NPs. PD-L1 and PD-L2 suppressed the function of PD-1^highCXCR5^-CD4⁺ T cells, and their levels were reduced in NPs. PD-1^highCXCR5^-CD4⁺ T-cell abundance was associated with the postsurgical relapse of NPs.

CONCLUSION

PD-1^highCXCR5^-CD4⁺ T cells participate in local immunoglobulin production independent of eLTs in NPs.

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.