Differentiation of chronic sinus diseases by measurement of inflammatory mediators

Biologics in Aspirin-Exacerbated Respiratory Disease and Allergic Bronchopulmonary Aspergillosis

Biologic medications have dramatically altered the landscape for treatment of allergic conditions including aspirin-exacerbated respiratory disease (AERD) and allergic bronchopulmonary aspergillosis (ABPA). Biologics should be considered for patients who are refractory to first line therapies for ABPA. Biologics should be discussed with patients with AERD. Variable responses to different biologics indicate that there may be various endotypes of AERD and ABPA, similar to asthma. Alternative biologics may be considered in patients who fail to respond to initial treatment.

The expression of MUC5AC in patients with rhinosinusitis: A systematic review and meta-analysis

BACKGROUND

To understand the connection between Muc5AC expression and the likelihood of rhinosinusitis, with the goal of providing insights into its prospective use as a biomarker.

METHODS

We searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and Wanfang databases for studies up to November 2023 to conduct a literature review. After screening and quality assessment, eligible studies meeting the criteria were included. Muc5AC expression and rhinosinusitis association was analyzed by STATA 14.0.

RESULTS

Including weighted mean difference and 95% confidence interval, were reported. The meta-analysis included 16 studies with 1448 rhinosinusitis patients. MUC5AC expression was significantly up-regulated in both chronic rhinosinusitis with nasal polyps (CRSwNP; WMD: 0.52; 95% CI: 0.41-0.63) and chronic rhinosinusitis without nasal polyps (CRSsNP; WMD: 0.42; 95% CI: 0.28-0.56) patients compared to controls. IHC positive area analysis corroborated these findings, with elevated MUC5AC levels in CRSwNP (WMD: 25.61; 95% CI: 22.41-28.81) and CRSsNP (WMD: 39.74; 95% CI: 25.6-53.88) patients. Subgroup analysis based on tissue type (nasal tissue fluid and sinus mucosa) consistently supported the overall results.

CONCLUSION

Our meta-analysis robustly demonstrates a significant association between elevated MUC5AC expression and rhinosinusitis risk. This finding underscores the potential of MUC5AC as a molecular marker, providing valuable insights for future research and potential therapeutic interventions in rhinosinusitis management.

SYSTEMATIC REVIEW REGISTRATION

CRD42024518932.

The epithelial barrier theory and its associated diseases

The prevalence of many chronic noncommunicable diseases has been steadily rising over the past six decades. During this time, over 350,000 new chemical substances have been introduced to the lives of humans. In recent years, the epithelial barrier theory came to light explaining the growing prevalence and exacerbations of these diseases worldwide. It attributes their onset to a functionally impaired epithelial barrier triggered by the toxicity of the exposed substances, associated with microbial dysbiosis, immune system activation, and inflammation. Diseases encompassed by the epithelial barrier theory share common features such as an increased prevalence after the 1960s or 2000s that cannot (solely) be accounted for by the emergence of improved diagnostic methods. Other common traits include epithelial barrier defects, microbial dysbiosis with loss of commensals and colonization of opportunistic pathogens, and circulating inflammatory cells and cytokines. In addition, practically unrelated diseases that fulfill these criteria have started to emerge as multimorbidities during the last decades. Here, we provide a comprehensive overview of diseases encompassed by the epithelial barrier theory and discuss evidence and similarities for their epidemiology, genetic susceptibility, epithelial barrier dysfunction, microbial dysbiosis, and tissue inflammation.

Transglutaminase 1: Emerging Functions beyond Skin

Transglutaminase enzymes catalyze Ca2+- and thiol-dependent posttranslational modifications of glutamine-residues that include esterification, hydrolysis and transamidation, which results in covalent protein-protein crosslinking. Among the eight transglutaminase family members in mammals, transglutaminase 1 (TG1) plays a crucial role in skin barrier formation via crosslinking and insolubilizing proteins in keratinocytes. Despite this established function in skin, novel functions have begun merging in normal tissue homeostasis as well as in pathologies. This review summarizes our current understanding of the structure, activation, expression and activity patterns of TG1 and discusses its putative novel role in other tissues, such as in vascular integrity, and in diseases, such as cancer and fibrosis.

Eosinophil extracellular traps in respiratory ailment: Pathogenic mechanisms and clinical translation

Background

Eosinophilic extracellular traps (EETs) are reticular complexes comprising deoxyribonucleic-Acid (DNA) fibers and granule proteins.

Aims

EETs play a crucial role in antimicrobial host responses and are pathogenic when overproduced or under degraded. EETs created by eosinophils appear to enable vital immune responses against extra-cellular pathogens, nevertheless, trap overproduction is evident in pathology.

Materials & Methods

As considerably research is performed, new data affirmed that EETs can alter the outcome of respiratory ailment.

Results

We probe into the disclosure and specificity of EETs produced in reaction to various stimuli and propose a role for those frameworks in ailment pathogenesis and the establishment of chronic, unresolved inflammation.

Discussion

Whether EETs can be used as a prospective brand-new target for the diagnosis, treatment and prognosis of respiratory ailments is a scientific theme worth studying.

Conclusion

We probe into the disclosure and specificity of EETs produced in reaction to various stimuli and propose a role for those frameworks in ailment pathogenesis and the establishment of chronic, unresolved inflammation.

Identification of hub genes associated with neutrophils in chronic rhinosinusitis with nasal polyps

Neutrophil infiltration plays a key role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). However, pertinent mechanisms remain poorly elucidated. Here, we obtained the data from gene expression omnibus (GEO) and gene set enrichment analysis (GSEA) to identify and validate neutrophil-associated hub genes in CRSwNP. We found that four neutrophil-associated hub genes, namely ICAM1, IL-1β, TYROBP, and BCL2A1, were markedly upregulated and positively correlated with neutrophil infiltration levels in patients with CRSwNP. Subsequently, this was confirmed by real-time quantitative PCR. In conclusion, we identified the role of neutrophil infiltration in the pathophysiology of CRSwNP, which may be the potential targets for the diagnosis and treatment of CRSwNP.

Managing Patients with Hypereosinophilic Syndrome: A Statement from the Italian Society of Allergy, Asthma, and Clinical Immunology (SIAAIC)

Hypereosinophilic syndrome (HES) encompasses a heterogeneous and complex group of different subtypes within the wider group of hypereosinophilic disorders. Despite increasing research interest, several unmet needs in terms of disease identification, pathobiology, phenotyping, and personalized treatment remain to be addressed. Also, the prospective burden of non-malignant HES and, more in general, HE disorders is currently unknown. On a practical note, shortening the diagnostic delay and the time to an appropriate treatment approach probably represents the most urgent issue, even in light of the great impact of HES on the quality of life of affected patients. The present document represents the first action that the Italian Society of Allergy, Asthma, and Clinical Immunology (SIAAIC) has finalized within a wider project aiming to establish a collaborative national network on HES (InHES-Italian Network on HES) for patients and physicians. The first step of the project could not but focus on defining a common language as well as sharing with all of the medical community an update on the most recent advances in the field. In fact, the existing literature has been carefully reviewed in order to critically integrate the different views on the topic and derive practical recommendations on disease identification and treatment approaches.

Prevalence of type 2 inflammation in patients with chronic rhinosinusitis with nasal polyps in Saudi Arabia

Background

Chronic Rhinosinusitis (CRS) is a common condition causing a significant worldwide burden, affecting 5%-12% of the general population. CRS is classified into type 2 and non-type 2 disease based on endotype dominance. Type 2 inflammation is distinguished by the presence of IL-4, IL-5, and IL-13 cytokines, along with eosinophil and mast cell activation and recruitment. Evidence of type 2 inflammation is ascertained by tissue eosinophil count >10/high-power field (HPF) or serum eosinophil >250 cells/mcL or total immunoglobulin E (IgE) > 100 IU/ml.

Objectives

To investigate the prevalence and characteristics of type 2 inflammation in patients who presented with nasal polyps and underwent Endoscopic Sinus Surgery (ESS) in Saudi Arabia.

Design

A retrospective cross-sectional Study.

Methods

This study was conducted among patients who presented with nasal polyps and underwent ESS at King Saud University Medical City (KSUMC) from 2015 to 2020. Patients with nasal/sinus diseases other than Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) were excluded. Demographic data, olfaction status, and co-morbidities were collected, and radiological images were evaluated. Type 2-CRS was determined by meeting at least one of three predictor criteria (blood eosinophils ≥250 cells/mcL, tissue eosinophils ≥10/HPF, or total IgE levels ≥100 IU/ml). Blood parameters and histopathologic analysis were obtained for each patient.

Results

Of the 381 patients included in the study, the prevalence of type 2-CRS, based on the EPOS2020 criteria, was 99.7% in our population. Among these patients, 47.5% had hyposmia, 38.8% had anosmia, and 13.6% had normal olfaction. The most prevalent co-morbidity was allergic rhinitis, followed by bronchial asthma.

Conclusion

This study aimed to determine the prevalence of type 2 inflammation among patients Diagnosed with CRSwNP and underwent ESS in Saudi Arabia. The results showed a prevalence of 99.7%, indicating that almost all recorded patients with CRSwNP in our population had type 2 inflammation.

[Importance of aspirin challenges in patients with NSAID-exacerbated respiratory disease]

BACKGROUND

Nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD) is often characterized by a severe course of chronic rhinosinusitis with nasal polyps (CRSwNP), comorbid asthma, and NSAID hypersensitivity. The gold standard for N-ERD diagnosis is challenge with acetylsalicylic acid (ASA). In expert recommendations, the diagnosis of N-ERD is established based on a plausible positive history of NSAID hypersensitivity and CRSwNP with asthma.

OBJECTIVE

The following review describes the performance of ASA challenges and their sensitivity and specificity. It also examines the extent to which a positive history of NSAID hypersensitivity correlates with ASA challenge results in clinical trials and when ASA challenges should be performed.

RESULTS AND CONCLUSION

ASA challenges have high sensitivity and specificity. In clinical ASA challenge studies, there is a high concordance between a positive history of NSAID hypersensitivity obtained by rhinologists and the measured data of ASA challenge in patients with CRSwNP and comorbid asthma. Therefore, ASA challenge is primarily indicated in patients with an unclear history of NSAID hypersensitivity.

Antibody-based therapeutics for chronic rhinosinusitis with nasal polyps

INTRODUCTION

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a prevalent inflammatory condition with heterogenous underlying endotypes, the most common being type 2 mediated inflammation. Several biologics have been developed to target specific pro-inflammatory cytokines and their receptors with proven efficacy in both quantitative and qualitative outcomes in patients with severe uncontrolled disease. However, there is an ongoing debate on the role of biologics relative to conventional therapies for CRSwNP and their efficacy in patient subgroups with non-polyp type 2 disease.

AREAS COVERED

This review examines the evidence on the efficacy and safety of biologics in CRSwNP, recommendations for their use, and discusses the broader economic factors influencing their application in clinical practice.

EXPERT OPINION

Emerging real-life data demonstrating the variable efficacy of the available biologics for patients with CRSwNP, coupled with the high cost compared to conventional therapies such as surgery, renders biologics to be considered as an add-on therapy in the majority of cases. However, ongoing research into increasing biologic dose intervals and novel therapies targeting alternative pathways may offer a more cost-effective and sustainable option in future.

S. aureus biofilm properties correlate with immune B cell subset frequencies and severity of chronic rhinosinusitis

Staphylococcus aureus mucosal biofilms are associated with recalcitrant chronic rhinosinusitis (CRS). However, S. aureus colonisation of sinus mucosa is frequent in the absence of mucosal inflammation. This questions the relevance of S. aureus biofilms in CRS etiopathogenesis. This study aimed to investigate whether strain-level variation in in vitro-grown S. aureus biofilm properties relates to CRS disease severity, in vitro toxicity, and immune B cell responses in sinonasal tissue from CRS patients and non-CRS controls. S. aureus clinical isolates, tissue samples, and matched clinical datasets were collected from CRS patients with nasal polyps (CRSwNP), CRS without nasal polyps (CRSsNP), and controls. B cell responses in tissue samples were characterised by FACS. S. aureus biofilms were established in vitro, followed by measuring their properties of metabolic activity, biomass, colony-forming units, and exoprotein production. S. aureus virulence was evaluated using whole-genome sequencing, mass spectrometry and application of S. aureus biofilm exoproteins to air-liquid interface cultures of primary human nasal epithelial cells (HNEC-ALI). In vitro S. aureus biofilm properties were correlated with increased CRS severity scores, infiltration of antibody-secreting cells and loss of regulatory B cells in tissue samples. Biofilm exoproteins from S. aureus with high biofilm metabolic activity had enriched virulence genes and proteins, and negatively affected the barrier function of HNEC-ALI cultures. These findings support the notion of strain-level variation in S. aureus biofilms to be critical in the pathophysiology of CRS.

Comparison of cytokine expression and disease severity between plasma cell-dominant and eosinophil-dominant patients in chronic rhinosinusitis with nasal polyps

PURPOSE

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease characterized by inflammation of the nasal and sinus mucosa. The inflammatory patterns may differ among patients, leading to different subtypes based on the dominant inflammatory cell type. This study aimed to compare the differences in cytokine expression and disease severity between plasma cell-dominant and eosinophil-dominant subtypes in patients with CRSwNP.

METHODS

This study included 53 CRSwNP patients and 19 control subjects who did not have asthma or a history of cigarette smoking. The expression of cytokines and inflammatory cells was assessed via enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, respectively.

RESULTS

Among the cytokines analyzed, only IL-6 was significantly different between the two subtypes. A greater proportion of mast cells and IgE cells was present in plasma cell-dominant CRSwNP patients than in eosinophil-dominant group. For the three disease severity scores (LMK-CT, TPS and SNOT-22), objective scores (LMK-CT and TPS) were greater in the eosinophil-dominant CRSwNP group, while the opposite result was shown for the subjective score (SNOT-22). Additionally, the percentage of plasma cell-dominant cells was significantly positively correlated with disease severity according to the TPS and SNOT-22 scores.

CONCLUSIONS

Our data revealed that plasma cell-dominant inflammation, a subtype of type 2 CRS, was significantly correlated with subjective disease severity. The study also highlights the role of IL-6, IgE and mast cells as distinguishing factors between eosinophil-dominant and plasma cell-dominant CRSwNP. This information could be useful for clinical diagnosis and personalized treatment.

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.

Visual and bibliometric analysis of chronic rhinosinusitis and nasal polyps

Background

Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by persistent sinonasal inflammation and sinus microbiome dysbiosis. Nasal polyps (NPs) are one of the main manifestations that cause diverse clinical symptoms of CRS.

Objective

We sought to conduct a bibliometric and visual analysis of articles on CRS and NPs published between 2003 and 2022 to provide researchers with the current state of research and potential directions.

Methods

We searched relevant articles from 2003 to 2022 in the Web of Science database. VOSviewer and the Bibliometrix R package were used to perform the bibliometric analysis.

Results

A total of 3907 publications were retrieved. The United States made the highest contributions to global research, followed by China. Northwestern University had the most publications. The most published author was C. Bachert, followed by R. P. Schleimer and R. J. Schlosser. The authors with the most co-citations were C. Bachert, W. J. Fokkens, and P. Gevaert. Moreover, the journal with the most publications was the International Forum of Allergy & Rhinology, and the Journal of Allergy and Clinical Immunology was the most cited. "Covid-19," "biologics," and "type 2 inflammation" were the top current research hotspots.

Conclusions

The United States and Northwestern University were the leading country and institution in researching CRS and NPs. C. Bachert was the most influential expert. The International Forum of Allergy & Rhinology and the Journal of Allergy and Clinical Immunology were leading journals. "Covid-19," "biologics," and "type 2 inflammation" were the trending topics.

Olfactory Loss in Rhinosinusitis: Mechanisms of Loss and Recovery

Chronic rhinosinusitis (CRS) is a highly prevalent disease and up to 83% of CRS patients suffer from olfactory dysfunction (OD). Because OD is specifically seen in those CRS patients that present with a type 2 eosinophilic inflammation, it is believed that type 2 inflammatory mediators at the level of the olfactory epithelium are involved in the development of this olfactory loss. However, due to the difficulties in obtaining tissue from the olfactory epithelium, little is known about the true mechanisms of inflammatory OD. Thanks to the COVID-19 pandemic, interest in olfaction has been growing rapidly and several studies have been focusing on disease mechanisms of OD in inflammatory conditions. In this paper, we summarize the most recent data exploring the pathophysiological mechanisms underlying OD in CRS. We also review what is known about the potential capacity of olfactory recovery of the currently available treatments in those patients.

Identification of neutrophils and eosinophils in upper airway mucosa with immunofluorescence multiplex image cytometry

Characterization of inflammation in chronic rhinosinusitis with (CRSwNP) and without nasal polyps (CRSsNP) is an ongoing research process. To overcome limitations of current cytologic techniques, we investigated whether immunofluorescence multiplex image cytometry could quantify intact neutrophils, eosinophils, and other immune cells in solid upper airway mucosa. We used a four-channel immunofluorescence-microscopy technique for the simultaneous detection of the leukocyte marker CD45, the neutrophil marker myeloperoxidase, two eosinophil markers, i.e., major basic protein and eosinophil peroxidase, and DAPI (4',6-diamidin-2-phenylindole), in formalin-fixed paraffin-embedded upper airway tissue samples of patients with CRSwNP and CRSsNP, as well as of patients free of CRS with inferior turbinate hypertrophy (controls). Image acquisition and analysis were performed with TissueFAXS and StrataQuest (TissueGnostics, Vienna, Austria), respectively. Positive and negative immunostaining were differentiated with a specific fluorescence signal/background signal ratio. Isotype controls were used as negative controls. In six controls, nine patients with CRSsNP, and 11 patients with CRSwNP, the median area scanned and median cell count per patient were 14.2 mm2 and 34,356, respectively. In CRSwNP, the number of eosinophils was three times higher (23%) than that of neutrophils (7%). Three times more immune cells were encountered in CRSwNP (33%) compared to CRSsNP (11%). In controls, inflammation was balanced between the epithelial layer and lamina propria, in contrast to CRS (three times more pronounced inflammation in the lamina propria). The quantification of intact neutrophils, eosinophils, and other immune cells in solid tissue with undisrupted architecture seems feasible with immunofluorescence multiplex image cytometry.

Neuroimmune interplay during type 2 inflammation: Symptoms, mechanisms, and therapeutic targets in atopic diseases

Type 2 inflammation is characterized by overexpression and heightened activity of type 2 cytokines, mediators, and cells that drive neuroimmune activation and sensitization to previously subthreshold stimuli. The consequences of altered neuroimmune activity differ by tissue type and disease; they include skin inflammation, sensitization to pruritogens, and itch amplification in atopic dermatitis and prurigo nodularis; airway inflammation and/or hyperresponsiveness, loss of expiratory volume, airflow obstruction and increased mucus production in asthma; loss of sense of smell in chronic rhinosinusitis with nasal polyps; and dysphagia in eosinophilic esophagitis. We describe the neuroimmune interactions that underlie the various sensory and autonomic pathologies in type 2 inflammatory diseases and present recent advances in targeted treatment approaches to reduce type 2 inflammation and its associated symptoms in these diseases. Further research is needed to better understand the neuroimmune mechanisms that underlie chronic, sustained inflammation and its related sensory pathologies in diseases associated with type 2 inflammation.

Eosinophil extracellular traps in eosinophilic chronic rhinosinusitis induce Charcot-Leyden crystal formation and eosinophil recruitment

Eosinophil extracellular traps (EETs) are implicated in various eosinophil-associated diseases; however, their role in chronic rhinosinusitis (CRS) remains unclear. In the present study, 57 CRS patients were enrolled, and immunofluorescence was used to analyze EETs in eosinophilic (eCRS) and non-eosinophilic (Non-eCRS) tissues. MSD was used to examine IL-4, IL-5, and IL-13 concentrations in tissue homogenates. Charcot-Leyden crystals (CLCs) protein expression was detected in PMA, PMA+DNase I, and blank control eosinophils using ELISA. Eotaxin-3 mRNA and protein levels were measured in human nasal epithelial cells (HNECs) cultured with EETs, EETs+DNase I, DNase I, and unstimulated eosinophils using PCR and ELISA. EETs were significantly increased in eCRS tissues compared with Non-eCRS (P<0.001), and correlated with VAS and Lund-Mackay CT scores. IL-5 expression was related to EETs formation (r = 0.738, P<0.001). PMA-stimulated eosinophils exhibited higher CLCs protein levels (P<0.01). Co-culturing HNECs with EETs significantly increased eotaxin-3 mRNA and protein levels (P<0.0001, P<0.001) compared with other groups. The study suggests EETs formation is elevated in eCRS patients and is involved in CLCs formation and chemokine secretion, promoting eosinophilic inflammation.

Endotypic heterogeneity and pathogenesis in chronic rhinosinusitis

PURPOSE OF REVIEW

This review aims to provide updates in realms of endotypic heterogeneity, pathogenesis at the molecular level, potential of biomarkers, and cutting-edge scope of biologics in CRS.

RECENT FINDINGS

High-dimensional analyses, such as transcriptomes, and machine learning, have significantly enhanced CRS endotyping, uncovering diverse pathogenetic mechanisms contributing to its heterogeneity. The dynamic process of epithelial remodeling in CRS pathogenesis has gained more clarity and support as exemplified by IL-13 and oncostatin M (OSM) that are shown intricately linked to epithelial barrier dysfunction. Moreover, anti-dsDNA autoantibody, BAFF, periostin, and cystatin SN show promise as potentials biomarkers, offering diagnostic and prognostic value for CRS.

SUMMARY

The identification of inflammatory molecules involved in endotype specific signaling pathways provides insights into the underlying mechanisms and verifiable biomarkers for diagnosis and prediction of disease severity. More comprehensive clinical studies should be conducted to facilitate biologics from bench to bedside in treating CRS.

Lactobacillus rhamnosus dampens cytokine and chemokine secretion from primary human nasal epithelial cells infected with rhinovirus

AIMS

To investigate the effect of Lactobacillus rhamnosus on viral replication and cellular response to human rhinovirus (HRV) infection, including the secretion of antiviral and inflammatory mediators from well-differentiated nasal epithelial cells (WD-NECs).

METHODS AND RESULTS

The WD-NECs from healthy adult donors (N = 6) were cultured in vitro, exposed to different strains of L. rhamnosus (D3189, D3160, or LB21), and infected with HRV (RV-A16) after 24 h. Survival and adherence capacity of L. rhamnosus in a NEC environment were confirmed using CFSE-labelled isolates, immunofluorescent staining, and confocal microscopy. Shed virus and viral replication were quantified using TCID50 assays and RT-qPCR, respectively. Cytotoxicity was measured by lactate dehydrogenase (LDH) activity. Pro-inflammatory mediators were measured by multiplex immunoassay, and interferon (IFN)-λ1/3 was measured using a standard ELISA kit. Lactobacillus rhamnosus was able to adhere to and colonize WD-NECs prior to the RV-A16 infection. Lactobacillus rhamnosus did not affect shed RV-A16, viral replication, RV-A16-induced IFN-λ1/3 production, or LDH release. Pre-exposure to L. rhamnosus, particularly D3189, reduced the secretion of RV-A16-induced pro-inflammatory mediators by WD-NECs.

CONCLUSIONS

These findings demonstrate that L. rhamnosus differentially modulates RV-A16-induced innate inflammatory immune responses in primary NECs from healthy adults.

[Features of inflammatory endotypes and phenotypes in chronic rhinosinusitis]

Recently, significant progress has been made in identifying the cellular and molecular mechanisms responsible for the pathogenesis of chronic rhinosinusitis (CRS). Cohort studies of CRS have led to advances in the clinical understanding of this disease. New therapeutic agents have been approved or are undergoing clinical trials to expand treatment options for this disease. One of the promising areas in medicine is the provision of personalized clinical care. From this perspective, CRS can be divided into three different endotypes depending on the type of underlying inflammatory response. In the United States, CRS with and without nasal polyps is predominantly characterized as the second inflammatory endotype. CRS with nasal polyps (about 17%) and without nasal polyps (up to 20%) belongs to the 1st and 3rd inflammatory endotypes, respectively. And if for the second inflammatory endotype the effectiveness of targeted biological therapy is beyond doubt, then for the first and third inflammatory endotypes the principles of such conservative therapy are under active development. Moreover, large validated studies to confirm associations between CRS phenotypes and endotypes, as well as to find effective biological markers of inflammatory endotypes, remain to be performed.

The Association Between Eosinophils and the Disease Process in Destructive Non-invasive Fungal Rhinosinusitis

OBJECTIVE

This study aims to investigate the significance of eosinophils in the progression and prognosis of destructive non-invasive fungal rhinosinusitis.

METHODS

This was a retrospective study of 126 patients who were operated on for a nasal sinus disease between 2010 and 2017; of these, 56 met the inclusion criteria. These were divided into two groups: (i) Group 1, with only the destructive non-invasive sinus polyposis type, and (ii) Group 2, with all types of nasal polyposis other than the destructive non-invasive sinus fungal polyposis type. Data including demographic data, paranasal sinuses (PNS) CT scans, pre- and post-operative eosinophils count, histopathology of polyps, and fungal cultures were collected from medical records from King Abdulaziz University Hospital, Jeddah, Saudi Arabia. A nonparametric Wilcoxon signed-rank test was used to determine a significant difference of p< 0.05. We performed multivariate analysis using repeated measure analysis of covariance (ANCOVA) and adjusted for confounders such as age, sex, pre- and post-operative IgE, fungal culture, and histopathology of the disease. Interaction between age, sex, IgE, and proportion of eosinophils was assessed at a p-value of 0.05.

RESULTS

A significant difference was found between pre-and post-operative blood eosinophils levels in Group 1 (p= 0.01) after adjusting for confounders such as age, sex, fungal culture, pre and post IgE, and histopathology of the disease. However, no significant difference was found in Group 2 (p= 0.663) even after adjusting for age, sex, fungal culture, pre and post IgE, and histopathology of the disease. We did not find any significant interaction (P>0.05) between pre- and post-operative levels of eosinophils with age, sex, and fungal culture among Group 1 and Group 2.

CONCLUSIONS

There is a statistically significant difference in blood eosinophils between pre- and post-operative levels in studied cases of destructive non-invasive fungal polyposis, a difference is not seen in nasal sinus polyp cases other than destructive non-invasive fungal polyposis types. High pre-operative eosinophils levels in destructive non-invasive fungal sinus polyposis types demonstrated the importance of eosinophils in the pathogenesis of this disease. The blood eosinophils can therefore be considered an important factor in the disease process and an indicator of the disease prognosis and destructive behavior.

Unraveling the Role of Epithelial Cells in the Development of Chronic Rhinosinusitis

The pathophysiology of CRS is multifactorial and complex yet needs to be completed. Recent evidence emphasizes the crucial part played by epithelial cells in the development of CRS. The epithelial cells act as physical barriers and play crucial roles in host defense, including initiating and shaping innate and adaptive immune responses. This review aims to present a comprehensive understanding of the significance of nasal epithelial cells in CRS. New research suggests that epithelial dysfunction plays a role in developing CRS through multiple mechanisms. This refers to issues with a weakened barrier function, disrupted mucociliary clearance, and irregular immune responses. When the epithelial barrier is compromised, it can lead to the passage of pathogens and allergens, triggering inflammation in the body. Furthermore, impaired mucociliary clearance can accumulate pathogens and secretions of inflammatory mediators, promoting chronic inflammation. Epithelial cells can release cytokines and chemokines, which attract and activate immune cells. This can result in an imbalanced immune response that continues to cause inflammation. The interaction between nasal epithelial cells and various immune cells leads to the production of cytokines and chemokines, which can either increase or decrease inflammation. By comprehending the role of epithelial cells in CRS, we can enhance our understanding of the disease's pathogenesis and explore new therapeutics.

Staphylococcus aureus biofilm properties and chronic rhinosinusitis severity scores correlate positively with total CD4+ T-cell frequencies and inversely with its Th1, Th17 and regulatory cell frequencies

Chronic rhinosinusitis (CRS) represents chronic inflammation of the sinus mucosa characterised by dysfunction of the sinuses' natural defence mechanisms and induction of different inflammatory pathways ranging from a Th1 to a Th2 predominant polarisation. Recalcitrant CRS is associated with Staphylococcus aureus dominant mucosal biofilms; however, S. aureus colonisation of the sinonasal mucosa has also been observed in healthy individuals challenging the significance of S. aureus in CRS pathogenesis. We aimed to investigate the relationship between CRS key inflammatory markers, S. aureus biofilm properties/virulence genes and the severity of the disease. Tissue samples were collected during endoscopic sinus surgery from the ethmoid sinuses of CRS patients with (CRSwNP) and without (CRSsNP) nasal polyps and controls (n = 59). CD3+ T-cell subset frequencies and key inflammatory markers of CD4+ helper T cells were determined using FACS analysis. Sinonasal S. aureus clinical isolates were isolated (n = 26), sequenced and grown into biofilm in vitro, followed by determining their properties, including metabolic activity, biomass, colony-forming units and exoprotein production. Disease severity was assessed using Lund-Mackay radiologic scores, Lund-Kennedy endoscopic scores and SNOT22 quality of life scores. Our results showed that S. aureus biofilm properties and CRS severity scores correlated positively with total CD4+ T-cell frequencies but looking into CD4+ T-cell subsets showed an inverse correlation with Th1 and Th17 cell frequencies. CD4+ T-cell frequencies were higher in patients harbouring lukF.PV-positive S. aureus while its regulatory and Th17 cell subset frequencies were lower in patients carrying sea- and sarT/U-positive S. aureus. Recalcitrant CRS is characterised by increased S. aureus biofilm properties in relation to increased total CD4+ helper T-cell frequencies and reduced frequencies of its Th1, Th17 and regulatory T-cell subsets. These findings offer insights into the pathophysiology of CRS and could lead to the development of more targeted therapies.

Targeting Epithelium Dysfunction and Impaired Nasal Biofilms to Treat Immunological, Functional, and Structural Abnormalities of Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) with (CRSwNP) or without (CRSsNP) nasal polyps is a prevalent and heterogeneous disorder existing as a spectrum of clinical conditions with complex underlying pathomechanisms. CRS comprises a broad syndrome characterized by multiple immunological features involving complex interactions between the genes, the microbiome, host- and microbiota-derived exosomes, the epithelial barrier, and environmental and micromilieu exposures. The main pathophysiological feature is an epithelial barrier disruption, accompanied by microbiome alterations and unpredictable and multifactorial immunologic overreactions. Extrinsic pathogens and irritants interact with multiple epithelial receptors, which show distinct expression patterns, activate numerous signaling pathways, and lead to diverse antipathogen responses. CRSsNP is mainly characterized by fibrosis and mild inflammation and is often associated with Th1 or Th17 immunological profiles. CRSwNP appears to be associated with moderate or severe type 2 (T2) or Th2 eosinophilic inflammation. The diagnosis is based on clinical, endoscopic, and imaging findings. Possible CRS biomarkers from the peripheral blood, nasal secretions, tissue biopsies, and nasally exhaled air are studied to subgroup different CRS endotypes. The primary goal of CRS management is to maintain clinical control by nasal douching with isotonic or hypertonic saline solutions, administration of nasal and systemic steroids, antibiotics, biologic agents, or, in persistent and more severe cases, appropriate surgical procedures.

Diagnostic value of myeloperoxidase and eosinophil cationic protein in nasal secretions for endotypes of chronic rhinosinusitis

OBJECTIVES

To explore associations between inflammatory endotypes and clinical presentations in CRS. To investigate the value of secretions myeloperoxidase (MPO) and eosinophilic cationic protein (ECP) detections in the diagnosis of endotypes of chronic rhinosinusitis (CRS), so as to provide guidance for the clinical application of MPO and ECP detection in secretions.

METHODS

We collected clinical symptom scores from patients with CRS and examined the differences between endotypes in clinical features. Patients' nasal secretions and polyps (or middle turbinate for control) were collected and their NEU number, EOS%, MPO and ECP levels were measured. Correlation analysis was performed for these biomarkers in secretions and tissues, respectively. Receiver operating characteristic curves were used to assess the predictive potential of the biomarkers mentioned above in nasal secretions.

RESULTS

Patients with Eos+Neu+ and Eos+Neu-CRS scored highest in most clinical symptom scores, while Eos-Neu+ and Eos-Neu-CRS scored lowest. Correlation analysis showed that tissues NEU number was correlated with NEU number and MPO level in nasal secretions (R = 0.4088; 0.6613); tissues EOS % was correlated with EOS% and ECP level in nasal secretions (R = 0.2344; 0.5774). To diagnose Neu+CRS, the highest area under the curve (AUC) (0.8961) was determined for MPO in secretions; the highest AUC (0.7400) was determined for NEU number in secretions. To diagnose Eos+Neu-CRS from Eos-Neu-CRS in Neu-CRS, the highest AUC (0.8801) was determined for ECP in secretions.

CONCLUSIONS

Clinical presentations are directly associated with CRS endotypes. Measurement of MPO and ECP in nasal secretions is useful for the endotypes diagnosis of CRS.

Eosinophil-mast cell pattern of intraepithelial infiltration as a marker of severity in CRSwNP

Chronic rhinosinusitis with nasal polyps (CRSwNP) is defined as a Type 2 eosinophilic disease, while CRSsNP is considered a Type 1 neutrophilic disease. Since neutrophils are also activated in eosinophilic CRSwNP, the eosinophil-neutrophil dualism has been revaluated. Among the inflammatory cells infiltrating sinus-nasal tissues, the role of mast cells (MCs) is not already recognized, although Clinical-Cytological Grading, which defines the severity of CRSwNP, attributes to mixed eosinophil-MC forms of CRSwNP a greater risk of recurrence. We aimed to examine nasal polyps from both a cytological and histopathological point of view, to evaluate the presence and localization of MCs. Cytological and histological examination of 39 samples of nasal polyps were performed. Immunohistochemistry was used to evaluate the presence of Tryptase + CD117 + MCs, which were counted both in the epithelial layer and in the lamina propria. A statistically significant correlation was found between intraepithelial MCs and CRSwNP severity (p < 0.001) and between the total eosinophil count and the total mast cell count (p < 0.001). Cytological examination and immunohistochemistry were comparable in detecting the presence of intraepithelial MCs (p = 0.002). The histological cut-off of 6 intraepithelial MCs was identified to detect severe CRSwNP (p < 0.001). MCs have been shown to be located in the lamina propria of almost all eosinophilic nasal polyps without significantly affecting their severity. Intraepithelial MCs are associated with greater severity of CRSwNP. Histopathological criteria of the eosinophil-MC form of CRSwNP in addition to the eosinophilic one, should be defined to guarantee patients effective and tailored treatments.

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.

Diagnostic value and underlying mechanism of nasal nitric oxide in eosinophilic chronic rhinosinusitis with nasal polyps

PURPOSE

Nitric oxide (NO) is an important messenger molecule widely present in the human body. However, the role of nasal NO (nNO) in eosinophilic chronic rhinosinusitis with nasal polyps (Eos CRSwNP) remain unclear. This study aimed to investigate the diagnostic value and underlying mechanism of nNO in Eos CRSwNP.

METHODS

The medical records of 84 non-Eos CRSwNP patients, 55 Eos CRSwNP patients, and 37 control subjects were retrospectively reviewed. The diagnostic value of nNO for Eos CRSwNP was assessed. The expression of inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and tight junctions (TJs) components claudin-1, occludin, and ZO-1 was detected in the nasal polyps. Primary human nasal epithelial cells (HNECs) were co-treated with eNOS inhibitor (L-NAME) or Akt inhibitor (MK-2206), interleukin (IL)-13, and dexamethasone (Dex). The level of NO and the expression of TJs and Akt/eNOS pathways were examined.

RESULTS

The nNO levels of the CRSwNP group were significantly lower than those of the control group. Compared with the non-Eos CRSwNP group, the Eos CRSwNP group showed higher nNO level. The combination of nNO level, eosinophilic percentage, and posterior ethmoid score had a better predictive value for Eos CRSwNP (AUC = 0.855). The expression of iNOS, eNOS, and p-eNOS was higher in the CRSwNP groups than in the control group, and p-eNOS expression was higher in the Eos CRSwNP group than in the non-Eos CRSwNP group. The expression of TJs was lower in the Eos CRSwNP group than in the non-Eos CRSwNP and control group. IL-13 decreased TJ expression in HNECs, while Dex promoted Akt and eNOS phosphorylation, NO production and TJ expression. Furthermore, these effects of Dex were inhibited by L-NAME and MK-2206 in HNECs.

CONCLUSION

nNO may have a high diagnostic value in Eos CRSwNP, and Akt/eNOS pathway may promote the generation of NO to protect TJs. NO may have a potentially important role in the diagnosis and treatment of Eos CRSwNP.

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.

Therapeutic Strategies to Prevent the Recurrence of Nasal Polyps after Surgical Treatment: An Update and In Vitro Study on Growth Inhibition of Fibroblasts

Chronic rhinosinusitis with nasal polyps (CRSwNP) is the most bothersome phenotype of chronic rhinosinusitis, which is typically characterized by a Type 2 inflammatory reaction, comorbidities and high rates of nasal polyp recurrence, causing severe impact on quality of life. Nasal polyp recurrence rates, defined as the number of patients undergoing revision endoscopic sinus surgery, are 20% within a 5 year period after surgery. The cornerstone of CRSwNP management consists of anti-inflammatory treatment with local corticosteroids. We performed a literature review regarding the therapeutic strategies used to prevent nasal polyp recurrence after surgical treatment. Finally, we report an in vitro study evaluating the efficacy of lysine-acetylsalicylic acid and other non-steroidal anti-inflammatory drugs (ketoprofen and diclofenac) on the proliferation of fibroblasts, obtained from nasal polyp tissue samples. Our study demonstrates that diclofenac, even more so than lysine-acetylsalicylic acid, significantly inhibits fibroblast proliferation and could be considered a valid therapeutic strategy in preventing CRSwNP recurrence.

Dupilumab (Dupixent®) tends to be an effective therapy for uncontrolled severe chronic rhinosinusitis with nasal polyps: real data of a single-centered, retrospective single-arm longitudinal study from a university hospital in Germany

INTRODUCTION

Chronic rhinosinusitis with nasal polyps (CRSwNP) is an inflammatory disease, which is usually type 2-mediated in the western hemisphere, associated with severe therapeutic and socioeconomic challenges. The first targeted systemic treatment option for severe uncontrolled CRSwNP is a human monoclonal antibody against the interleukin-4 receptor α (IL-4Rα) subunit called dupilumab, which was approved for subcutaneous administration in Germany in October 2019. The purpose of this study is to investigate the efficacy of dupilumab in real life in patients treated with dupilumab in label according to license in our department in 2019-2021.

MATERIALS AND METHODS

Since October 2019, we have investigated 40 patients (18 men, 22 women) treated with dupilumab in a single-center, retrospective single-arm longitudinal study. The following parameters were collected before treatment (baseline), at 1 month, 4 months, 7 months, 10 months, and 13 months: the Sino-Nasal Outcome Test-22 (SNOT-22), the forced expiratory pressure in 1 s (FEV-1), the olfactometry using Sniffin' Sticks-12 identification test (SSIT), a visual analog scale of the total complaints, the Nasal Polyp Score (NPS), histologic findings as well as total serum IgE, eosinophilic cationic protein in serum and blood eosinophils.

RESULTS

The average age was 52.7 years (± 15.3). The follow-up period was 13 months. The SNOT-22 average was 60 points (± 22.2) at the first visit, 28.2 points (± 17.1) after 4 months and 20.8 points (± 17.7) after 13 months. The NPS was 4.3 points (± 1.5), after 4 months 2.1 points (± 1.3) and after 13 months 1.4 points (± 1.1). Olfactometry showed 3.2 points (± 3.7) at the baseline, 7.0 points (± 4.0) after 4 months and 7.8 points (± 3.5) after 13 months. The other parameters also improved. Most parameters showed linear dependence in the slopes under therapy (p < 0.001). Adverse side effects were mostly only mild, and no rescue therapy was needed.

CONCLUSION

There is a clear improvement in the medical condition and symptoms in all categories mentioned under therapy with dupilumab, as well as a reduction in the need for systemic glucocorticoids and revision surgery as rescue treatment. Our results show that dupilumab tends to be an effective therapy alternative for severe CRSwNP.

Hypoxia disrupts the nasal epithelial barrier by inhibiting PTPN2 in chronic rhinosinusitis with nasal polyps

BACKGROUND

Hypoxia is involved in inflammation and immune response; however, its role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) is not fully understood. We aimed to investigate the mechanisms by which hypoxia disrupts the nasal epithelial barrier in CRSwNP.

METHODS

The expression of hypoxia-inducible factor-1α (HIF-1α), protein tyrosine phosphatase non-receptor type 2 (PTPN2), and tight junction (TJ) components (claudin-4, occludin, and ZO-1) was detected in nasal polyps using immunohistochemistry, western blotting, and qRT-PCR. Primary human nasal epithelial cells (HNECs), BEAS-2B cells, and an eosinophilic CRSwNP (Eos CRSwNP) mouse model were used to explore the potential mechanisms by which hypoxia disrupts the nasal epithelial barrier.

RESULTS

HIF-1α expression in the non-Eos and Eos CRSwNP groups was higher than in the control group, and the expression of PTPN2 and TJs in the non-Eos and Eos CRSwNP groups were lower than those in the control group. Hypoxia decreased the expression of PTPN2 and TJs and increased epithelial cell permeability in HNECs, which was blocked by the HIF-1α inhibitor PX-478. PTPN2 overexpression inhibited hypoxia-induced downregulation of TJ expression in BEAS-2B cells, whereas PTPN2-knockdown aggravated the effects of hypoxia. In the Eos CRSwNP mouse model, both PX-478 and PTPN2 overexpression reduced the formation of nasal polypoid lesions, permeability of the nasal epithelium, and restored TJ expression.

CONCLUSIONS

Our data indicate that hypoxia-induced HIF-1α downregulates TJ expression by inhibiting PTPN2, thereby disrupting the nasal epithelial barrier and promoting CRSwNP development. HIF-1α and PTPN2 may be potential targets for the treatment of CRSwNP.

Effects of Pendrin Protein in Nasal Epithelial Cells on Mucin Production in the Context of Type 2 Inflammation

Background: Chronic rhinosinusitis (CRS) is a heterogeneous disease. The pathogenesis of chronic sinusitis is still unclear; however, the nasal cavity and paranasal sinuses are commonly affected by type 2 inflammation, which is caused by Th2 cytokines such as interleukin (IL)-5, IL-4, and IL-13. Previous studies have shown that pendrin promotes local infiltration of neutrophils through the production of human neutrophil elastase (HNE), which is essential for the secretion of mucin 5AC (MUC5AC) in chronic inflammatory diseases of the lower respiratory tract. This study investigated pendrin expression and its relationship to mucin in type 2 inflammation. Methods: A total of 40 patients (10 CRS patients with nasal polyps,10 CRS patients without nasal polyps, and 20 nasal septum deviation patients) were included in this study and were divided into the CRS group and the NC group. A normal nasal mucosa tissue culture model was established in vitro. IL-13 was used to stimulate primary cultures of human nasal epithelial cells (HNECs). Western blot (WB), enzyme-linked immunosorbent assay (ELISA), and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the expression of pendrin, MUC5AC, and MUC5B. After transfecting HNECs with siRNA pendrin or negative control (NC), EGF receptor (EGFR), HNE, MUC5AC, and MUC5B expression were analyzed using qRT-PCR, WB, or ELISA in terms of their relationships with pendrin. Pendrin expression in the tissue was also analyzed. Results: After IL-13 stimulation, pendrin, MUC5AC, and MUC5B expression levels were upregulated; the optimal concentration of IL-13 was 50 ng/mL. The expression levels of HNE, EGFR, MUC5AC, and MUC5B were downregulated after transfection with siRNA pendrin-1650. Pendrin expression in the NC group was lower than in the CRS group. Conclusion: IL-13 is implicated in the inflammation of nasal mucosa, and pendrin is closely related to the excessive secretion of mucin. The expression of mucin is downregulated after transfection with siRNA pendrin. There is a positive relationship between pendrin and EFGR/HNE. Moreover, pendrin plays an important role in type 2 inflammation.

Treatment Strategy of Uncontrolled Chronic Rhinosinusitis with Nasal Polyps: A Review of Recent Evidence

Chronic rhinosinusitis (CRS) is recognized as a heterogeneous disease with a wide range of clinical features, resulting in significant morbidity and cost to the healthcare system. While the phenotypic classification is determined by the presence or absence of nasal polyps and comorbidities, the endotype classification has been established based on molecular biomarkers or specific mechanisms. Research on CRS has now developed based on information based on three major endotypes: types 1, 2, and 3. Recently, biological therapies targeting type 2 inflammation have been clinically expanded and may be applied to other inflammatory endotypes in the future. The purpose of this review is to discuss the treatment options according to the type of CRS and summarize recent studies on new therapeutic approaches for patients with uncontrolled CRS with nasal polyps.

Eosinophil-derived interferon-γ drives transmembrane protein 119-induced new bone formation in chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory sinonasal disease characterized by eosinophilic infiltration and new bone formation. These changes indicate the severity and prognosis of CRSwNP and may be closely linked to each other.

METHODS

We performed RNA sequencing to screen specific osteogenic molecules and validated transmembrane protein 119 (TMEM119) expression by quantitative polymerase chain reaction (qPCR) and immunohistochemistry analyses. TMEM119 knockdown was performed to observe the downregulation of bone mineralization. We validated the bone-forming activity of interferon-γ (IFN-γ) and its signaling pathways in cultured primary sinus bone cells. Cellular sources of IFN-γ were identified using immunohistochemistry and immunofluorescence analyses. Interleukin-4-eosinophil-IFN-γ axis and the effect of dupilumab were investigated in Eol-1 cells.

RESULTS

We observed elevated IFN-γ levels and eosinophils in the nasal fluid and predominantly eosinophil-derived IFN-γ in the sinus mucosa of patients with CRSwNP. TMEM119 expression and bone-forming activities were increased in the osteitic and primary sinus bone cells of CRSwNP. IFN-γ treatment enhanced bone mineralization and TMEM119 expression via signal transducer and activator of transcription 1 (STAT1) signaling. Moreover, TMEM119 knockdown inhibited sinus bone cell mineralization and dupilumab attenuated IFN-γ secretion by IL4-stimulated Eol-1 cells.

CONCLUSION

Eosinophil-derived IFN-γ promotes the bone-forming activities of sinus bone cells via the STAT1-TMEM119 signaling pathway. Interleukin-4-eosinophil-IFN-γ axis may be crucial for TMEM119-mediated new bone formation in CRSwNP.

B Lineage Cells and IgE in Allergic Rhinitis and CRSwNP and the Role of Omalizumab Treatment

BACKGROUND

Allergic rhinitis (AR) and chronic rhinosinusitis (CRS) are two prevalent nasal diseases where both type 2 inflammation and immunoglobulin E (IgE) may play important roles. Although they can exist independently or comorbidly, subtle but important differences exist in immunopathogenesis.

OBJECTIVE

To summarize current knowledge of pathophysiological roles of B lineage cells and IgE in AR and CRS with nasal polyps (CRSwNP).

METHODS

Searched PubMed database, reviewed AR and CRSwNP-related literature, and discussed disease diagnosis, comorbidity, epidemiology, pathophysiology, and treatment. Similarities and differences in B-cell biology and IgE are compared in the 2 conditions.

RESULTS

Both AR and CRSwNP have evidence for pathological type 2 inflammation, B-cell activation and differentiation, and IgE production. However, distinctions exist in the clinical and serological profiles at diagnosis, as well as treatments utilized. B-cell activation in AR may more frequently be regulated in the germinal center of lymphoid follicles, whereas CRSwNP may occur via extrafollicular pathways although controversies remain in these initial activating events. Oligoclonal and antigen-specific IgE maybe predominate in AR, but polyclonal and antigen-nonspecific IgE may predominate in CRSwNP. Omalizumab has been shown efficacious in treating both AR and CRSwNP in multiple clinical trials but is the only Food and Drug Administration-approved anti-IgE biologic to treat CRSwNP or allergic asthma. Staphylococcus aureus frequently colonizes the nasal airway and has the ability to activate type two responses including B-cell responses although the extent to which it modulates AR and CRSwNP disease severity is being investigated.

CONCLUSION

This review highlights current knowledge of the roles of B cells and IgE in the pathogenesis of AR and CRSwNP and a small comparison between the 2 diseases. More systemic studies should be done to elevate the understanding of these diseases and their treatment.

Endotyping Chronic Rhinosinusitis with Nasal Polyps: Understanding Inflammation Beyond Phenotypes

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogenous group of inflammatory conditions impacting the nose and paranasal sinuses. Our understanding of the underlying pathobiology of CRSwNP has substantially improved due to ongoing translational research efforts. Advances in treatment options, including targeted respiratory biologic therapy for CRSwNP, allow for more personalized approaches for CRSwNP patient care. Patients with CRSwNP are typically classified to one or more endotype based on the presence of type 1, type 2, and type 3 inflammation. This review will discuss recent advances in our understanding of CRSwNP and how this may impact current and future treatment approaches for patients with CRSwNP.

Role of Nasal Fibroblasts in Airway Remodeling of Chronic Rhinosinusitis: The Modulating Functions Reexamined

Chronic rhinosinusitis (CRS) is a multifactorial inflammatory disease of the nose and sinuses that affects more than 10% of the adult population worldwide. Currently, CRS is classified into endotypes according to the inflammatory response (Th1, Th2, and Th17) or the distribution of immune cells in the mucosa (eosinophilic and non-eosinophilic). CRS induces mucosal tissue remodeling. Extracellular matrix (ECM) accumulation, fibrin deposition, edema, immune cell infiltration, and angiogenesis are observed in the stromal region. Conversely, epithelial-to-mesenchymal transition (EMT), goblet cell hyperplasia, and increased epithelial permeability, hyperplasia, and metaplasia are found in the epithelium. Fibroblasts synthesize collagen and ECM, which create a structural skeleton of tissue and play an important role in the wound-healing process. This review discusses recent knowledge regarding the modulation of tissue remodeling by nasal fibroblasts in CRS.

The Diagnostic and Prognostic Role of Biomarkers in Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) refers to an inflammatory disease of the sinonasal mucosa, with a significant economic burden and impact on quality of life. The diagnosis of CRS is conventionally made on careful history and physical examination, including nasoendoscopic assessment which requires technical expertise. There has been increasing interest in using biomarkers in the non-invasive diagnosis and prognostication of CRS, tailored to the disease inflammatory endotype. Potential biomarkers currently being studied can be isolated from peripheral blood, exhaled nasal gases or nasal secretions, as well as sinonasal tissue. In particular, various biomarkers have revolutionized the way in which CRS is managed, revealing new inflammatory pathways where novel therapeutic drugs are employed to curb the inflammatory process, which may be different from one patient to the next. Biomarkers that have been extensively studied in CRS, such as eosinophil count, IgE, and IL-5, have been associated with a T_H2 inflammatory endotype which correlates with an eosinophilic CRSwNP phenotype that predicts a poorer prognosis, tends to recur after conventional surgical treatment, but responds to glucocorticoid treatment. Newer biomarkers that demonstrate potential, such as nasal nitric oxide, can support a diagnosis of CRS with or without nasal polyps, especially when invasive tests such as nasoendoscopy are unavailable. Other biomarkers such as periostin can be used to monitor disease course after treatment of CRS. With a personalized treatment plan, the management of CRS can be individualized, optimizing treatment efficiency and reducing adverse outcomes. As such, this review aims to compile and summarize the existing literature regarding the utility of biomarkers in CRS in terms of diagnosis and prognostication, and also makes recommendations for further studies to fill current knowledge gaps.

Neutrophilic inflammation in chronic rhinosinusitis

PURPOSE OF REVIEW

Over the last years, extensive research has been done on neutrophils and their contribution in chronic rhinosinusitis (CRS), and made it clear that they are more than just a bystander in this disease. In this article, we will review all recent publications on this topic and look to what the future hold regarding therapeutics targeting the neutrophilic inflammation in CRS.

RECENT FINDINGS

Evidence is growing that the presence of neutrophils are associated with a worse disease outcome in certain CRS patient groups. They are highly activated in type 2 inflammations and exhibit damaging properties through their proteases, contributing to the chronicity of the disease. Several recent studies identified useful biomarkers and targets for future therapeutics.

SUMMARY

The findings we review in this manuscript are of utmost importance in unraveling the complexity of CRS and provide us with the necessary knowledge for future clinical practices.

Oxidative Stress and Antioxidants in Chronic Rhinosinusitis with Nasal Polyps

Oxidative stress results from an imbalance between the production of reactive oxygen species and the body's antioxidant defense system. It plays an important role in the regulation of the immune response and can be a pathogenic factor in various diseases. Chronic rhinosinusitis (CRS) is a complex and heterogeneous disease with various phenotypes and endotypes. Recently, an increasing number of studies have proposed that oxidative stress (caused by both environmental and intrinsic stimuli) plays an important role in the pathogenesis and persistence of CRS. This has attracted the attention of several researchers. The relationship between the presence of reactive oxygen species composed of free radicals and nasal polyp pathology is a key topic receiving attention. This article reviews the role of oxidative stress in respiratory diseases, particularly CRS, and introduces potential therapeutic antioxidants that may offer targeted treatment for CRS.

IgA-producing B cells in lung homeostasis and disease

Immunoglobulin A (IgA) is the most abundant Ig in mucosae where it plays key roles in host defense against pathogens and in mucosal immunoregulation. Whereas intense research has established the different roles of secretory IgA in the gut, its function has been much less studied in the lung. This review will first summarize the state-of-the-art knowledge on the distribution and phenotype of IgA⁺ B cells in the human lung in both homeostasis and disease. Second, it will analyze the studies looking at cellular and molecular mechanisms of homing and priming of IgA⁺ B cells in the lung, notably following immunization. Lastly, published data on observations related to IgA and IgA⁺ B cells in lung and airway disease such as asthma, cystic fibrosis, idiopathic pulmonary fibrosis, or chronic rhinosinusitis, will be discussed. Collectively it provides the state-of-the-art of our current understanding of the biology of IgA-producing cells in the airways and identifies gaps that future research should address in order to improve mucosal protection against lung infections and chronic inflammatory diseases.

Effects of Neutrophil and Eosinophil Extracellular Trap Formation on Refractoriness in Chronic Rhinosinusitis With Nasal Polyps

PURPOSE

This study investigated the clinical implications of neutrophil extracellular trap (NET) formation (NETosis) and eosinophil extracellular trap (EET) formation (EETosis) regarding refractoriness in chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP).

METHODS

Nasal polyp specimens were obtained from 117 patients with CRSwNP who received endoscopic sinus surgery. Disease control status at postoperative 1 year was assessed. Refractory cases were defined as partly controlled or uncontrolled cases according to the EPOS 2020 guidelines. NETosis and EETosis were evaluated through immunofluorescence staining (citrullinated histone H3-human neutrophil elastase and citrullinated histone-galectin-10, respectively) followed by manual counting. The z-score of NET and EET counts was used to define the following four groups: low extracellular trap formation (ETosis), NETosis-predominant, EETosis-predominant, and high-ETosis.

RESULTS

The refractory and non-refractory groups showed significant differences in the tissue eosinophil count (P = 0.005) and EET count (P = 0.029). The tissue neutrophil count and the NET/neutrophil ratio were significantly different between the refractory and non-refractory groups of patients with neutrophilic CRS (P = 0.045, 0.031, respectively). Refractoriness significantly differed among the low-ETosis (30.77%), NETosis-predominant (47.83%), EETosis-predominant (56.67%), and high-ETosis (83.33%) groups (P = 0.005).

CONCLUSIONS

The results of this study suggest that tissue Eosinophilia and EETosis may play a prognostic role, primarily in CRSwNP and thattissue neutrophilia and NETosis can play as prognostic biomarkers in neutrophilic CRSwNP.

Increased Expression of SERPINB10 Associated with Postoperative Recurrence in Chronic Rhinosinusitis with Nasal Polyps

Background

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common upper airway inflammatory disorder with a high rate of postoperative recurrence. SERPINB10 is a proinflammatory cytokine expressed on epithelial cells, but its role in CRSwNP has not been described. This study is aimed at exploring the SERPINB10 expression in CRSwNP and its relationship with postoperative recidivation.

Methods

We recruited 140 individuals, consisting of 60 patients with CRSwNP, 40 patients with chronic rhinosinusitis without nasal polyps (CRSsNP), and 40 healthy controls (HCs). Tissue specimens were collected during the surgery, and SERPINB10 expression was determined by reverse transcription-polymerase chain reaction, western blotting, and immunofluorescence. We determined the tissue SERPINB10 expression levels in CRSwNP and examined its clinical value in predicting postoperative recurrence.

Results

We determined that tissue SERPINB10 mRNA and protein levels were increased in the CRSwNP group, especially in the recurrent CRSwNP group, compared with the CRSsNP and HC groups (p < 0.05), and SERPINB10 mRNA levels were correlated with peripheral and tissue eosinophil counts and percentages (p < 0.05). Binary logistic regression analysis and receiver operating characteristic (ROC) curves suggested that the expressions of tissue SERPINB10 mRNA were significantly linked to postoperative recurrence in CRSwNP patients (AUC = 0.741, p < 0.001).

Conclusion

Elevated local SERPINB10 levels in patients with CRSwNP were related to tissue eosinophilic inflammation and disease recurrence. These data suggested that SERPINB10 might contribute to the eosinophilic inflammation in CRSwNP and appeared to be a potential biomarker for the prediction of relapse after surgery.

[Research progress of biomarkers in nasal secretions in endotypes diagnosis and clinical application of chronic rhinosinusitis]

With the development of studies on the endotypes of chronic rhinosinusitis （CRS） and the biomarkers of nasal secretions, the studies of CRS endotypes based on nasal secretion have become more abundant. This paper summarizes the endotypes classification of CRS, the collection methods of nasal secretion and the nasal secretion biomarkers related to the endotypes of CRS, in order to provide a reference for establishing the corresponding endotypes of CRS based on the nasal secretion biomarkers.

A Prospective Analysis of Systemic and Local Aeroallergen Sensitivity in Central Compartment Atopic Disease

OBJECTIVE

To compare systemic allergen sensitivity and local allergen sensitivity in the sinonasal tissue of patients with a recently identified subtype of chronic rhinosinusitis strongly associated with allergy: central compartment atopic disease (CCAD).

STUDY DESIGN

Prospective cohort study.

SETTING

Academic tertiary care rhinology clinic.

METHODS

Fifteen participants with endoscopic and radiographic evidence of CCAD underwent systemic allergy testing with skin testing and measurement of serum specific immunoglobulin E (sIgE) to 15 regionally common aeroallergens. Local allergen sensitivity was determined by measuring sIgE to these same 15 allergens in their sinonasal tissue. sIgE testing was performed by ImmunoCAP assay.

RESULTS

Of the 15 participants, 14 were sensitive to at least 1 allergen locally in the central compartment and systemically on skin or serum testing. Among all participants, 4 were sensitive to allergens on central compartment sIgE testing that they were not sensitive to on skin and serum sIgE testing (range, 1-8 discordant allergens). Comparisons between local and systemic aeroallergen sensitivity results showed statistically significant correlations (P < .05) ranging from weak to strong.

CONCLUSION

Systemic allergy testing is recommended in the initial workup for CCAD. Local allergen sensitivities may be present in a subset of patients with CCAD. Further study of the clinical significance of these sensitivities should be undertaken in CCAD, with evaluation of the role of medical therapies and allergen immunotherapy in the treatment of CCAD.

CRS-PRO and SNOT-22 correlations with type 2 inflammatory mediators in chronic rhinosinusitis

The 22-item Sino-Nasal Outcome Test (SNOT-22) and 12-item Patient Reported Outcomes in Chronic Rhinosinusitis (CRS-PRO) instrument are validated patient-reported outcomes measures in CRS. In this study we assess the correlation of these with type 2 (T2) biomarkers before and after endoscopic sinus surgery (ESS).

METHODS

Middle meatal mucus data were collected and the SNOT-22 and CRS-PRO were administered to 123 patients (71 CRS without nasal polyps [CRSsNP], 52 CRS with nasal polyps [CRSwNP]) with CRS before and 6 to 12 months after undergoing ESS. Interleukin (IL)-4, IL-5, IL-13, and eosinophilic cationic protein (ECP) were measured using a multiplexed bead assay and enzyme-linked immunoassay. Pre- and post-ESS SNOT-22 and CRS-PRO were compared with T2 biomarkers.

RESULTS

Before ESS neither PROM correlated with any biomarker. After ESS, CRS-PRO showed a correlation with 2 mediators (IL-5 and IL-13: p = 0.012 and 0.003, respectively) compared with none for the SNOT-22. For CRSwNP patients, pre-ESS CRS-PRO and SNOT-22 correlated with IL-4 (p = 0.04 for both). However, after ESS, CRS-PRO correlated with 3 biomarkers (IL-5, IL-13, and ECP: p = 0.02, 0.024, and 0.04, respectively) and SNOT-22 with 2 biomarkers (IL-5 and IL-13: p = 0.038 and 0.02, respectively). There were no significant relationships between any of the T2 biomarkers pre- or post-ESS among patients with CRSsNP. Exploratory analyses of the subdomains showed the SNOT-22 rhinologic and CRS-PRO rhinopsychologic subdomains correlated better with the T2 biomarkers. On individual item analysis, IL-13 correlated significantly post-ESS with 8 of 12 items on the CRS-PRO vs 6 of 22 items on the SNOT-22.

CONCLUSION

The CRS-PRO total score showed a significant correlation with T2 biomarkers especially when assessed post-ESS and among CRSwNP patients.

Low Diversity and Instability of the Sinus Microbiota over Time in Adults with Cystic Fibrosis

Chronic rhinosinusitis (CRS) is a common, yet underreported and understudied manifestation of upper respiratory disease in people with cystic fibrosis (CF). Recently developed standard of care guidelines for the management of CF CRS suggest treatment of upper airway disease may ameliorate lower airway disease. We sought to determine whether changes to sinus microbial community diversity and specific taxa known to cause CF lung disease are associated with increased respiratory disease and inflammation. We performed 16S rRNA gene sequencing, supplemented with cytokine analyses, microscopy, and bacterial culturing, on samples from the sinuses of 27 adults with CF CRS. At each study visit, participants underwent endoscopic paranasal sinus sampling and clinical evaluation. We identified key drivers of microbial community composition and evaluated relationships between diversity and taxa with disease outcomes and inflammation. Sinus community diversity was low, and the composition was unstable, with many participants exhibiting alternating dominance between Pseudomonas aeruginosa and staphylococci over time. Despite a tendency for dominance by these two taxa, communities were highly individualized and shifted composition during exacerbation of sinus disease symptoms. Exacerbations were also associated with communities dominated by Staphylococcus spp. Reduced microbial community diversity was linked to worse sinus disease and the inflammatory status of the sinuses (including increased interleukin-1β [IL-1β]). Increased IL-1β was also linked to worse sinus endoscopic appearance, and other cytokines were linked to microbial community dynamics. Our work revealed previously unknown instability of sinus microbial communities and a link between inflammation, lack of microbial community diversity, and worse sinus disease. IMPORTANCE Together with prior sinus microbiota studies of adults with CF chronic rhinosinusitis, our study underscores similarities between sinus and lower respiratory tract microbial community structures in CF. We show how community structure tracks with inflammation and several disease measures. This work strongly suggests that clinical management of CRS could be leveraged to improve overall respiratory health in CF. Our work implicates elevated IL-1β in reduced microbiota diversity and worse sinus disease in CF CRS, suggesting applications for existing therapies targeting IL-1β. Finally, the widespread use of highly effective cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy has led to less frequent availability of spontaneous expectorated sputum for microbiological surveillance of lung infections. A better understanding of CF sinus microbiology could provide a much-needed alternative site for monitoring respiratory infection status by important CF pathogens.