Murine model of eosinophilic chronic rhinosinusitis with nasal polyposis inducing neuroinflammation and olfactory dysfunction.

BACKGROUND: Chronic rhinosinusitis (CRS) is a common inflammatory condition affecting the nasal and paranasal sinus mucosa, often accompanied by olfactory dysfunction. Eosinophilic CRS with nasal polyps (ECRSwNP) is a subtype of CRS characterized by eosinophilic infiltration. Animal models for ECRSwNP with olfactory dysfunction are necessary for exploring potential therapeutic strategies. OBJECTIVE: The aim of this study was to establish a mouse model of ECRSwNP combined with olfactory dysfunction in a shorter time frame using intranasal ovalbumin and Aspergillus protease (AP) administration. The efficacy of the model was validated by evaluating sinonasal inflammation, cytokine levels, olfactory function, and neuroinflammation in the olfactory bulb. METHODS: Male BALB/c mice were intranasally administered ovalbumin and AP for 6 and 12 weeks to induce ECRSwNP. The resultant ECRSwNP mouse model underwent histologic assessment, cytokine analysis of nasal lavage fluid, olfactory behavioral tests, and gene expression profiling to identify neuroinflammatory markers within the olfactory bulb. RESULTS: The developed mouse model exhibited substantial eosinophil infiltration, increased levels of inflammatory cytokines in nasal lavage fluid, and confirmed olfactory dysfunction through behavioral assays. Furthermore, olfactory bulb inflammation and reduced mature olfactory sensory neurons were observed in the model. CONCLUSION: This study successfully established a validated mouse model of ECRSwNP with olfactory dysfunction within a remarkably short span of 6 weeks, providing a valuable tool for investigating the pathogenesis and potential therapies for this condition. The model offers an efficient approach for future research in CRS with nasal polyps and olfactory dysfunction.

Galectin-10 in serum extracellular vesicles reflects asthma pathophysiology.

BACKGROUND: Novel biomarkers (BMs) are urgently needed for bronchial asthma (BA) with various phenotypes and endotypes. OBJECTIVE: We sought to identify novel BMs reflecting tissue pathology from serum extracellular vesicles (EVs). METHODS: We performed data-independent acquisition of serum EVs from 4 healthy controls, 4 noneosinophilic asthma (NEA) patients, and 4 eosinophilic asthma (EA) patients to identify novel BMs for BA. We confirmed EA-specific BMs via data-independent acquisition validation in 61 BA patients and 23 controls. To further validate these findings, we performed data-independent acquisition for 6 patients with chronic rhinosinusitis without nasal polyps and 7 patients with chronic rhinosinusitis with nasal polyps. RESULTS: We identified 3032 proteins, 23 of which exhibited differential expression in EA. Ingenuity pathway analysis revealed that protein signatures from each phenotype reflected disease characteristics. Validation revealed 5 EA-specific BMs, including galectin-10 (Gal10), eosinophil peroxidase, major basic protein, eosinophil-derived neurotoxin, and arachidonate 15-lipoxygenase. The potential of Gal10 in EVs was superior to that of eosinophils in terms of diagnostic capability and detection of airway obstruction. In rhinosinusitis patients, 1752 and 8413 proteins were identified from EVs and tissues, respectively. Among 11 BMs identified in EVs and tissues from patients with chronic rhinosinusitis with nasal polyps, 5 (including Gal10 and eosinophil peroxidase) showed significant correlations between EVs and tissues. Gal10 release from EVs was implicated in eosinophil extracellular trapped cell death in vitro and in vivo. CONCLUSION: Novel BMs such as Gal10 from serum EVs reflect disease pathophysiology in BA and may represent a new target for liquid biopsy approaches.

IL-4Rα signaling promotes barrier-altering oncostatin M and IL-6 production in aspirin-exacerbated respiratory disease.

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) is a severe disease involving dysregulated type 2 inflammation. However, the role other inflammatory pathways play in AERD is poorly understood. OBJECTIVE: We sought to broadly define the inflammatory milieu of the upper respiratory tract in AERD and to determine the effects of IL-4Rα inhibition on mediators of nasal inflammation. METHODS: Twenty-two AERD patients treated with dupilumab for 3 months were followed over 3 visits and compared to 10 healthy controls. Nasal fluid was assessed for 45 cytokines and chemokines using Olink Target 48. Blood neutrophils and cultured human mast cells, monocytes/macrophages, and nasal fibroblasts were assessed for response to IL-4/13 stimulation in vitro. RESULTS: Of the nasal fluid cytokines measured, nearly one third were higher in AERD patients compared to healthy controls, including IL-6 and the IL-6 family-related cytokine oncostatin M (OSM), both of which correlated with nasal albumin levels, a marker of epithelial barrier dysregulation. Dupilumab significantly decreased many nasal mediators, including OSM and IL-6. IL-4 stimulation induced OSM production from mast cells and macrophages but not from neutrophils, and OSM and IL-13 stimulation induced IL-6 production from nasal fibroblasts. CONCLUSION: In addition to type 2 inflammation, innate and IL-6-related cytokines are also elevated in the respiratory tract in AERD. Both OSM and IL-6 are locally produced in nasal polyps and likely promote pathology by negatively affecting epithelial barrier function. IL-4Rα blockade, although seemingly directed at type 2 inflammation, also decreases mediators of innate inflammation and epithelial dysregulation, which may contribute to dupilumab's therapeutic efficacy in AERD.

Factors for predicting the outcome of surgery for non-eosinophilic chronic rhinosinusitis with nasal polyps.

BACKGROUND: Despite the large patient base in Asia, the prognostic factors of patients with non-eosinophilic chronic rhinosinusitis with nasal polyps (CRSwNP) remain largely undetermined. OBJECTIVE: We aimed to systematically investigate the predictive value of clinical and biological variables for non-eosinophilic CRSwNP. METHODS: Fifty-one patients with non-eosinophilic CRSwNP who underwent functional endoscopic surgery were recruited. Clinical information and assessment were comprehensively collected before and after surgery. A broad spectrum of biomarkers was measured in tissue homogenates using multiple assays. A random forest algorithm and stepwise logistic regression were used to construct clinical, biological, and combined models. RESULTS: A total of 41.2% of non-eosinophilic CRSwNP patients were uncontrolled more than 6 months after surgery. We identified one clinical variable (22-item Sino-Nasal Outcome Test score) and four biomarkers (programmed cell death ligand 1, platelet-derived growth factor subunit B [PDGF-ß], macrophage inflammatory protein-3b, and PDGF-α) that were significantly predictive of the surgical outcome. The clinical, biological, and combined models showed predictive ability with areas under the curve of 0.78, 0.83, and 0.89, respectively. PDGF-ß and programmed cell death ligand 1 were identified as independent biomarkers for the prognosis of patients with CRSwNP without considerable eosinophilic infiltration. CONCLUSION: This study shows that clinical and biological factors, such as the 22-item Sino-Nasal Outcome Test score and PDGF-ß, are predictive of the post-functional endoscopic surgical prognosis of non-eosinophilic CRSwNP patients.

Systematic Review of Long Term Sinonasal Outcomes in CRSwNP after Endoscopic Sinus Surgery: A call for Unified and Standardized Criteria and Terms.

PURPOSE OF REVIEW: To present current evidence in long-term (> 5 years) results after endoscopic sinus surgery (ESS) focusing on Patients Reported Outcome Measures (PROMs) and other sinonasal outcomes while assessing the role of ESS in the treatment of CRSwNP, and identifying outcomes which affect the results of ESS and defining recommendations for future studies. RECENT FINDINGS: Long-term results of ESS in CRSwNP can be branched in PROMs and other objective measurements. Despite the heterogeneity of reported outcomes make it difficult to perform comparisons and meta-analysis, ESS improves PROMs, including symptoms, QOL and olfaction. Objectives outcomes such as NPS, LMS, type of surgery, or recurrence and revision surgery don't have a clear role in long-term results. Clustering patients suggest asthma, N-ERD, allergy, eosinophil count and IL-5 could have a role in predicting recurrence and severe disease. Long-term studies of CRSwNP treated with ESS are scarce. There is a significant need to standardize the report of results. The use of tools as SNOT-22, NPS, validated smell tests, defined criteria for disease recurrence and control and ESS extension in a unified systematic way could allow better comparisons between treatments in the new era of biologics.

Residual nasal polyp tissue following dupilumab therapy is associated with periostin-associated fibrosis.

PURPOSE: Dupilumab, an anti-interleukin-4 receptor alpha monoclonal antibody, is a new treatment for severe uncontrolled chronic rhinosinusitis with nasal polyps. However, data on the effect of dupilumab on histological changes in nasal polyp tissue are lacking. We aimed to investigate the effect of dupilumab on real-life clinical conditions and nasal polyp tissues from patients with eosinophilic chronic rhinosinusitis (ECRS), which is a refractory subtype. METHODS: We conducted an open-label, prospective, observational, single-centre study on 63 patients with refractory ECRS on the basis of the criteria of the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis Study. These patients had a history of surgery and received dupilumab for 24 weeks. Patient-reported sinonasal symptoms, T&T olfactometry and nasal polyp scores were prospectively evaluated. In 23 patients with residual nasal polyps following dupilumab treatment, changes in systemic and local periostin expression, and total collagen deposition in nasal polyp tissues were investigated before and after dupilumab administration. RESULTS: Dupilumab rapidly improved sinonasal symptoms and reduced the nasal polyp score 24 weeks after initiation. 40 (63.5%) patients had resolution of nasal polyps, but the reduction was limited in the remaining 23 (36.5%) patients. Periostin expression in serum and nasal lavage fluid was decreased, whereas periostin and the total collagen deposition area in subepithelial tissues in residual nasal polyps were enhanced after dupilumab administration. CONCLUSION: Dupilumab improves sinonasal symptoms and reduces the nasal polyp score in refractory ECRS. Periostin-associated tissue fibrosis may be involved in the differential effect of dupilumab on nasal polyp reduction.

IgE receptor of mast cells signals mediator release and inflammation via adaptor protein 14-3-3ζ.

BACKGROUND: Mast cells (MCs) are tissue-resident immune cells that mediate IgE-dependent allergic responses. Downstream of FcεRI, an intricate network of receptor-specific signaling pathways and adaptor proteins govern MC function. The 14-3-3 family of serine-threonine phosphorylation-dependent adapter proteins are known to organize intracellular signaling. However, the role of 14-3-3 in IgE-dependent activation remains poorly defined. OBJECTIVE: We sought to determine whether 14-3-3 proteins are required for IgE-dependent MC activation and whether 14-3-3 is a viable target for the treatment of MC-mediated inflammatory diseases. METHODS: Genetic manipulation of 14-3-3ζ expression in human and mouse MCs was performed and IgE-dependent mediator release assessed. Pharmacologic inhibitors of 14-3-3 and 14-3-3ζ knockout mice were used to assess 14-3-3ζ function in a MC-dependent in vivo passive cutaneous anaphylaxis (PCA) model of allergic inflammation. Expression and function of 14-3-3ζ were assessed in human nasal polyp tissue MCs. RESULTS: IgE-dependent mediator release from human MCs was decreased by 14-3-3ζ knockdown and increased by 14-3-3ζ overexpression. Deletion of the 14-3-3ζ gene decreased IgE-dependent activation of mouse MCs in vitro and PCA responses in vivo. Furthermore, the 14-3-3 inhibitor, RB-11, which impairs dimerization of 14-3-3, inhibited cultured MC and polyp tissue MC activation and signaling downstream of the FcεRI receptor and dose-dependently attenuated PCA responses. CONCLUSION: IgE/FcεRI-mediated MC activation is positively regulated by 14-3-3ζ. We identify a critical role for this p-Ser/Thr-binding protein in the regulation of MC FcεRI signaling and IgE-dependent immune responses and show that this pathway may be amenable to pharmacologic targeting.

Retinoic Acid Treatment Mitigates PM2.5-Induced Type 2 Inflammation: Insights into Modulation of Innate Immune Responses.

Some studies have demonstrated the effects of particulate matter (PM) on chronic rhinosinusitis with nasal polyps (CRSwNP) development, as well as the therapeutic role of retinoic acid (RA) in nasal polypogenesis. However, the immunologic effect of PM in innate lymphoid cells (ILCs) and the exact mechanism of the therapeutic effect of RA remain unclear. Therefore, the present study investigated the effects of fine-dust-induced inflammation in CRSwNP and the mechanisms of the therapeutic effect of RA. PM2.5 exposure exacerbated pathological damage in the nasal mucosa of mice with nasal polyps (NP) via upregulation of type 2 inflammation. Additionally, PM2.5 exposure increased the expression of type 2 cytokines and epithelial-cell-derived cytokines (IL-33 and IL-25) significantly, as well as the ILC populations in human-NP-derived epithelial cells (HNECs). Moreover, RA supplementation significantly increased the expression of ILCreg in Lin-CD45+CD127+ cells, which in turn increased the levels of the anti-inflammatory cytokine IL-10. The findings suggest that PM2.5 exposures could aggravate the CRSwNP type 2 inflammation, and RA treatment may ameliorate fine-dust-induced inflammation by modulating the innate immune response.

Increased CYR61 expression activates CCND1/c-Myc pathway to promote nasal epithelial cells proliferation in chronic rhinosinusitis with nasal polyps.

PURPOSE: Chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) is a chronic sinonasal inflammatory disease characterized histologically by hyperplastic nasal epithelium and epithelial cells proliferation. Cysteine-rich angiogenic inducer 61 (CYR61) acts as a positive regulator of cell cycle process. Cyclin D1 (CCND1) and c-Myc play key roles in the processes of cell cycle and cell growth. The purpose of our research was to explore the expression and roles of CYR61, CCND1 and c-Myc in CRSwNP. METHODS: FeaturePlot and vlnPlot functions embedded in the seurat package (version 4.1.1) of R software (version 4.2.0) were applied to explore the cellular distribution of CYR61, CCND1 and c-Myc in the single-cell RNA sequencing (scRNA-seq) dataset of nasal tissue samples. CYR61, CCND1 and c-Myc immunolabeling and mRNA levels in nasal tissue samples were assessed by immunohistochemistry and real-time PCR. Co-localization of CYR61, CCND1 and c-Myc with basal epithelial cell marker P63 was assayed using double-label immunofluorescence staining. Furthermore, we collected and cultured human nasal epithelial cells (HNEC) to assess the regulation and role of CYR61 in vitro study. RESULTS: CYR61, CCND1 and c-Myc were primarily expressed by nasal epithelial cells. Significant upregulation of CYR61, CCND1 and c-Myc positive cells and increased levels of CYR61, CCND1 and c-Myc mRNA were found in nasal polyps in comparison to control samples. Of note, CYR61 mRNA and protein levels were altered by SEB, LPS, IFN-γ, IL-13, IL-17A and TGF-ß1 in HNEC. In addition, CYR61 intervention could increase CCND1 and c-Myc mRNA and protein levels to promote HNEC proliferation, and siRNA against ITGA2 (si-ITGA2) could reverse CYR61 induced upregulation of CCND1 and c-Myc mRNA and protein levels in HNEC and cell proliferation of HNEC. CONCLUSIONS: CYR61, CCND1 and c-Myc were primarily expressed by epithelial cells in nasal mucosa. CYR61, CCND1 and c-Myc expression levels were increased in CRSwNP compared with controls. CYR61 could interact with ITGA2 to enhance HNEC proliferation via upregulating CCND1 and c-Myc levels in the HNEC, leading to hyperplastic nasal epithelium in CRSwNP.

Relationship between Eosinophilic and Neutrophilic Inflammation in Chinese Chronic Rhinosinusitis with Nasal Polyps.

INTRODUCTION: Chronic rhinosinusitis with nasal polyps (CRSwNPs) in China is characterized by a mixed eosinophilic-neutrophilic inflammation, linking to a more heterogeneous clinical phenotype. However, the relationship between eosinophilic and neutrophilic inflammation in Chinese patients with CRSwNP remains largely unknown. We aimed to further characterize the correlation between neutrophils with eosinophils in relation to clinical characters and disease control status after endoscopic sinus surgery (ESS). METHODS: A total of 242 patients were recruited and stratified based on tissue (≥10%) eosinophilia and (≥20/per high-power field) neutrophilia. Clinical characteristics and disease control status were compared between subgroups. Associations between tissue eosinophils and neutrophils were analyzed. RESULTS: The uncontrolled patients accounted for 41.3%, 41.3%, 17.1%, and 22.2% in subjects with concomitant tissue eosinophilia and neutrophilia (EN-high), isolated eosinophilia (E-high), isolated neutrophilia (N-high), and no eosinophilia and neutrophilia (EN-low), respectively. Positive correlations between tissue eosinophils and neutrophils were observed in patients with CRSwNP as well as in EN-high and N-high subgroups but not in E-high and EN-low subgroups. The EN-high subgroup had higher tissue eosinophil numbers than the other three subgroups. Both EN-high and E-high subgroups had higher rates of uncontrolled subjects than the N-high and EN-low subgroups; however, there was no difference in the rate of uncontrolled subjects between EN-high and E-high subgroups and between N-high and EN-low subgroups. CONCLUSION: Tissue neutrophils might have a potential interaction and mutual promotion effect with eosinophils in CRSwNP. However, tissue neutrophilia would not pose significant risk for poor disease control after ESS. Further larger, prospective studies are needed to confirm our findings.

Comparison of the clinical outcomes of patients with NSAID-exacerbated respiratory disease receiving aspirin or biologicals.

OBJECTIVE: NSAID-exacerbated respiratory disease (NERD) is characterized by exacerbation of respiratory symptoms after NSAID intake. While research for specific treatment options continues in patients who cannot tolerate or are unresponsive to aspirin treatment after aspirin desensitization (ATAD), biologicals have emerged as a new therapeutic option in NERD patients. The aim of this study was to compare the quality of life, and the sinonasal and respiratory outcomes of NERD patients treated with ATAD or biologicals. METHODS: Patients who have been followed up at a tertiary care allergy center and who have been receiving at least one of ATAD, mepolizumab or omalizumab for at least six months were included. Evaluations were made using sinonasal outcome test (SNOT-22), asthma control test (ACT), short form-36 (SF-36), blood eosinophil counts, need for recurrent functional endoscopic sinus surgeries (FESS), and asthma or rhinitis exacerbations requiring oral corticosteroids (OCS). RESULTS: A total of 59 patients comprised of 35 (59%) females and 24 (41%) males with a mean age of 46.1 (min-max, 20-70) years were included. The baseline blood eosinophil count was higher, and a significant decrease in blood eosinophil counts was observed in the mepolizumab group compared to ATAD group (p = 0.001, p < 0.001, respectively). At follow-up, the rate of recurrent FESS was lower in the group that received mepolizumab (p = 0.02). CONCLUSIONS: In NERD patients, mepolizumab significantly decreased blood eosinophil counts and recurrent FESS. There was no significant difference between the patients receiving ATAD or mepolizumab regarding other clinical parameters.

Diagnostic value of serum and tissue eosinophil in diagnosis of asthma among patients with chronic rhinosinusitis.

BACKGROUND: Chronic rhinosinusitis (CRS) is one of the most common chronic inflammatory diseases of sinonasal mucosa. Asthma among CRS patients is often underdiagnosed which makes the management of CRS more challenging. Therefore, using serum and tissue eosinophil as an indicator and predictor of asthma in CRS patients is vital for further preventing recurrent and increasing the effectiveness of treatment for CRS. OBJECTIVE: To determine the association and diagnostic ability of serum and tissue eosinophils in the diagnosis of asthma among CRS patients. METHODS: A cross-sectional study was conducted involving 24 CRS patients with asthma and without asthma, respectively, from the Otorhinolaryngology clinic of two tertiary hospitals located on the East Coast of Peninsular Malaysia. Serum and tissue eosinophils (obtained from nasal polyp) levels between both groups were compared. Association between serum and tissue eosinophils with asthma was evaluated using logistic regression analysis, adjusting for important sociodemographic characteristics. The diagnostic ability of serum and tissue eosinophil was then evaluated by assessing the receiver operating characteristic curve. RESULTS: A total of 48 CRS patients with a mean [SD] age of 47.50 [14.99] years were included. Patients with asthma had significantly higher serum [0.48 vs 0.35 × 109/L] and tissue eosinophil [100 vs 8.5 per HPF] levels. Tissue eosinophils were found to be an independent predictor of asthma with adjusted OR 1.05, p < 0.001, after adjusting for age and serum eosinophils. The area under the receiver operating characteristic curve for serum eosinophil was 69.0%. At optimal cut-off value (0.375 × 109/L), the sensitivity and specificity for serum eosinophil was 75.0% and 70.8%. The area under the receiver operating characteristic curve for tissue eosinophil was 93.4%. At the optimal cut-off value (58.0 per HPF), the sensitivity and specificity for tissue eosinophils were 79.2% and 91.7%, respectively. CONCLUSION: This study indicates a significantly higher level of serum and tissue eosinophils in CRS with asthma. However, there was no correlation between serum and tissue eosinophils in both group. Based on this study, the CRS patient needs to be screened for asthma if the level of serum eosinophil is > 0.375 × 109/L and tissue eosinophil > 58 per HPF.

The causal association between peripheral blood eosinophils and nasal polyps: a Mendelian randomization study.

OBJECTIVE: Observational studies suggested that peripheral blood eosinophils were associated with the risk of nasal polyps. However, these studies did not confirm the causality. This study aims to apply Mendelian randomization (MR) method to comprehensively assess the potential causal association between peripheral blood eosinophils and nasal polyps. METHODS: Genetic instrumental variables were extracted from the largest available genome-wide association study (GWAS) of European participants, which were used to investigate the relationship between peripheral blood eosinophils and nasal polyps. The inverse variance weighted method, the MR Egger method, and the weighted median method were applied for this analysis. MR-Egger intercept tests, leave-one-out analyses, and funnel plots were performed for the sensitivity analysis. RESULTS: With the inverse variance weighted method, the MR analysis suggested that there was a significant difference between peripheral blood eosinophils and the risk of nasal polyps (ukb-a-97, OR 1.004, 95% CI 1.003-1.005, p < 0.001; ukb-a-541, OR 1.005, 95% CI 1.004-1.006, p < 0.001; ukb-b-7211, OR 1.004, 95% CI 1.003-1.005, p < 0.001; ukb-b-8425, OR 1.004, 95% CI 1.003-1.005, p < 0.001; finn-b-J10_NASALPOLYP, OR 3.089, 95% CI 2.537-3.761, p < 0.001). Consistent results were also proved by using the weighted median method and the MR Egger method. CONCLUSIONS: Our findings reveal the causal effect of peripheral blood eosinophils on the increased risk of nasal polyps.

Subjective symptoms as predictors for eosinophilic chronic rhinosinusitis with nasal polyps in the Chinese population.

PURPOSE: To evaluate the putative association between subjective symptoms and eosinophilic inflammation in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). METHODS: A total of 102 patients with CRSwNP who underwent endoscopic sinus surgery were prospectively enrolled. The Sinonasal Outcomes Test-22 scores (SNOT-22), EuroQol 5-dimensional Questionnaire scores (ED-5D), and Lund-Mackay scores by computed tomography (CT) were obtained. Patients were grouped as eosinophilic CRSwNP (eCRSwNP) and non-eosinophilic CRSwNP (neCRSwNP). ECRSwNP was defined if tissue eosinophils of nasal polyps were greater than or equal to 8/HPF according to positive major basic protein (MBP) staining, and neCRSwNP otherwise. RESULTS: Thirty neCRSwNP and 72 eCRSwNP patients were included. ECRSwNP patients had higher incidences of asthma (p = 0.001), allergic rhinitis (p = 0.001), and ethmoid-to-maxillary opacification ratio on CT scans (p < 0.001), whereas the proportion of purulent discharge (p < 0.001) and maxillary sinus score (p = 0.002) was higher in the neCRSwNP patients. There were no significant differences between patients on the mains of the EQ-5D health utility values and total SNOT-22 score. However, eCRSwNP patients had higher SNOT-22 scores of sneezing (p = 0.006), runny nose (p < 0.001), and ear/facial domain (p = 0.012), and lower scores of thick nasal discharge (p = 0.015) and blockage (p = 0.042). Sneezing, thick nasal discharge, and blockage/congestion of nose were recognized as independent factors of CRSwNP. CONCLUSION: Sneezing was an independent predictor of eCRSwNP, and thick nasal discharge and blockage/congestion of nose were independent predictors of neCRSwNP.

IL-17A-producing sinonasal MAIT cells in patients with chronic rhinosinusitis with nasal polyps.

BACKGROUND: Diverse immune cells contribute to the pathogenesis of chronic rhinosinusitis (CRS), an inflammatory disease of the nasal cavity and paranasal sinuses. However, whether mucosal-associated invariant T (MAIT) cells are present in human sinonasal tissues remains unclear. Furthermore, the characteristics of sinonasal MAIT cells have not been studied in patients with CRS. OBJECTIVE: We investigated the phenotype, function, and clinical implications of MAIT cells in patients with CRS. METHODS: Peripheral blood and sinonasal tissue were obtained from patients with CRS with (CRSwNP) or without nasal polyps (CRSsNP) and healthy controls. MAIT cells were analyzed by flow cytometry. RESULTS: We found that MAIT cells are present in human sinonasal tissues from healthy controls and patients with CRS. The sinonasal MAIT cell population, but not peripheral blood MAIT cells, from patients with CRSsNP, noneosinophilic CRSwNP (NE-NP), or eosinophilic CRSwNP (E-NP) had a significantly higher frequency of activated cells marked by CD38 expression. In functional analysis, the sinonasal MAIT cell population from NE-NP and E-NP had a significantly higher frequency of IL-17A+ cells but lower frequency of IFN-γ+ or TNF+ cells than control sinonasal tissues. Furthermore, CD38 expression and IL-17A production by sinonasal MAIT cells significantly correlated with disease extent evaluated by the Lund-Mackay computed tomography score in patients with E-NP. CONCLUSIONS: Sinonasal MAIT cells exhibit an activated phenotype and produce higher levels of IL-17A in patients with CRSwNP. These alterations are associated with the extent of disease in patients with E-NP.

Rapid and sustained effect of dupilumab on clinical and mechanistic outcomes in aspirin-exacerbated respiratory disease.

BACKGROUND: Dupilumab, a mAb targeting IL-4Rα, improves upper and lower airway symptoms in patients with aspirin-exacerbated respiratory disease (AERD), but the mechanisms leading to clinical improvement are not fully elucidated. OBJECTIVE: Our aim was to identify the mechanistic basis of clinical improvement in patients with AERD treated with dupilumab. METHODS: A total of 22 patients with AERD were treated with dupilumab for 3 months for severe asthma and/or chronic rhinosinusitis with nasal polyps. Clinical outcomes were assessed at baseline and at 1 and 3 months after initiation of dupilumab. Nasal fluid, urine, blood, and inferior turbinate scrapings were collected at the 3 time points for determination of mediator levels, cellular assays, and RNA sequencing. RESULTS: Participants had rapid improvement in clinical measures, including sense of smell, sinonasal symptoms, and lung function after 1 month of treatment with dupilumab; the improvements were sustained after 3 months of dupilumab. Baseline severity of smell loss was correlated with lower nasal prostaglandin E2 levels. Dupilumab increased nasal prostaglandin E2 level and decreased levels of nasal albumin, nasal and urinary leukotriene E4, and serum and nasal IgE. Transcripts related to epithelial dysfunction and leukocyte activation and migration were downregulated in inferior turbinate tissue after treatment with dupilumab. There were no dupilumab-induced changes in nasal eosinophilia. CONCLUSION: Inhibition of IL-4Rα in AERD led to rapid improvement in respiratory symptoms and smell, with a concomitant improvement in epithelial barrier function, a decrease in inflammatory eicosanoid levels, and an increase in the anti-inflammatory eicosanoid prostaglandin E2 level. The therapeutic effects of dupilumab are likely due to decreased IL-4Rα signaling on respiratory tissue granulocytes, epithelial cells, and B cells.

Long-term efficacy and safety of omalizumab for nasal polyposis in an open-label extension study.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) frequently remains uncontrolled despite maximal medical therapy and sinonasal surgery, presenting several unmet needs and challenges. Omalizumab previously demonstrated efficacy in CRSwNP in duplicate phase 3, randomized, placebo-controlled trials (POLYP 1, POLYP 2). OBJECTIVE: This open-label extension evaluated the continued efficacy, safety, and durability of response of omalizumab in adults with CRSwNP who completed POLYP 1 or 2. METHODS: After 24 weeks of omalizumab or placebo in POLYP 1 and 2, patients (n = 249) received open-label omalizumab plus background nasal mometasone therapy for 28 weeks and were subsequently followed for 24 weeks after omalizumab discontinuation. Efficacy end points assessed change from baseline for the coprimary end points, Nasal Polyp Score and Nasal Congestion Score, and the secondary end points of Sino-Nasal Outcome Test 22, Total Nasal Symptom Score and its components, and University of Pennsylvania Smell Identification Test scores. Safety objectives included incidence of adverse events and adverse events leading to omalizumab discontinuation. RESULTS: Patients who continued omalizumab experienced further improvements across coprimary end points and secondary end points through 52 weeks. Patients who switched from placebo to omalizumab experienced favorable responses across end points through week 52 that were similar to POLYP 1 and 2 at week 24. After omalizumab discontinuation, scores gradually worsened over the 24-week follow-up, but remained improved from pretreatment levels for both groups. The safety profile was similar to previous reports. CONCLUSIONS: The efficacy and safety profile from this study supports extended omalizumab treatment up to 1 year for CRSwNP with inadequate response to nasal corticosteroids.

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.

Immunological mechanisms and treatable traits of chronic rhinosinusitis in Asia: A narrative review.

OBJECTIVES: To review the current literature on immunological mechanisms and treatable traits of chronic rhinosinusitis (CRS) in Asia. DESIGN: This is a narrative review of published data on the immunological mechanisms and treatable traits of CRS in Asia. Published English literature on CRS in Asian and Western countries was reviewed. Where available, the data extracted included epidemiology, immunology, bacterium, phenotype, endotype and treatment. RESULTS AND CONCLUSION: CRS is a heterogeneous disease characterised by persistent locoregional mucosal inflammation of the paranasal sinuses. The inflammatory signatures of CRS vary across patients with distinct racial and ethnic backgrounds and geographic areas. Compared to CRS patients in Western countries, Asian CRS patients display less eosinophilic and Type 2 inflammation, which is associated with lower asthma and allergic rhinitis comorbidities. In contrast, Asian patients with CRS have more prominent non-eosinophilic inflammation than those in Western countries. In addition, Asian CRS patients may have different bacterial colonisation than patients in Western countries. Our review suggests that the distinct immunological mechanisms between Asian and Western CRS patients may influence the clinical phenotype, responses to treatment and outcomes. The treatable trait is a new strategy and therapeutic target identified by phenotype or endotype and has been proposed as a new paradigm for the management of diseases. Improved understanding of CRS phenotypic and endotypic heterogeneity and incorporation of treatable traits into clinical care pathways may facilitate more effective selections of therapeutic interventions, including surgery and biologics.

Comparison of sinus distribution between nasal irrigation and nasal spray using fluorescein-labelled in patients with chronic rhinosinusitis: A randomised clinical trial.

OBJECTIVE: This study aims to compare the potential sinus distribution between high-volume nasal irrigation and nasal spray in chronic rhinosinusitis (CRS) patients who have not undergone sinus surgery. DESIGN AND SETTING: A randomised clinical study was conducted at the Otolaryngology-Head & Neck Surgery Department, Ramathibodi Hospital, Faculty of Medicine, Mahidol University. PARTICIPANTS: Forty patients undergoing endoscopic sinus surgery (ESS) for CRS. Thirty-eight patients met the inclusion criteria and were randomly assigned to receive nasal irrigation or nasal spray mixed with fluorescein sodium preoperatively. MAIN OUTCOME MEASURES: The primary outcome was the mean difference in the staining score of fluorescein in all sinuses between the two groups. RESULTS: The total fluorescein staining score for all sinuses in the nasal irrigation group was significantly higher than the score from the nasal spray group, with a mean difference score of 2.90, 95% confidence interval: 1.22-4.58, p = .001. The most significantly affected sinuses were the maxillary and the anterior ethmoid sinuses, while the frontal and sphenoid sinuses had only minimal staining from both techniques. CONCLUSION: Nasal irrigation is a potential route to deliver drugs into the sinus in unoperated CRS patients. However, it is not considered a superior method to nasal spray in the most challenging anatomical areas, that is, the frontal and sphenoid sinuses.