Mechanisms and pathogenesis of chronic rhinosinusitis

Clinical Practice Guideline: Surgical Management of Chronic Rhinosinusitis

OBJECTIVE

The purpose of this specialty-specific clinical practice guideline is to identify quality improvement opportunities and provide clinicians with trustworthy, evidence-based recommendations for the surgical management of chronic rhinosinusitis in adults. The target audience includes otolaryngologist-head and neck surgeons who manage adults with chronic rhinosinusitis, including candidacy and performance of endoscopic sinus surgery.

METHODS

This guideline was developed using the 55-page protocol published as the American Academy of Otolaryngology-Head and Neck Surgery Foundation's Clinical Practice Guideline Development Manual (3rd edition), which summarizes the methodology for assessments of current data, topic prioritization, development of key action statements (KASs), application of value judgments, and related procedures. The guideline group represented otolaryngologists, rhinologists, advanced practice nursing and physician assistants, and consumers who represented participating national professional organizations.

ACTION STATEMENTS

The Guideline Development Group made strong recommendations for the following KASs: Before considering surgery, the surgeon should verify an existing diagnosis of chronic rhinosinusitis to ensure established diagnostic criteria (signs and symptoms) from clinical practice guidelines are met, and the surgeon should assess candidacy for sinus surgery based on symptoms, disease characteristics, quality of life, and prior medical or surgical therapy (KASs 1A and 1B). The surgeon or their designee should not prescribe antibacterial therapy to an adult with chronic rhinosinusitis if significant or persistent purulent nasal discharge (anterior, posterior, or both) is absent on examination (KAS 3). The Guideline Development Group made recommendations for the following KASs: The surgeon should not endorse or require a predefined, one-size-fits-all regimen or duration of medical therapy (eg, antibiotics, steroids, antihistamines) as a prerequisite to sinus surgery for an adult with chronic rhinosinusitis (KAS 2). The surgeon should identify patients with chronic rhinosinusitis that would benefit most from surgery and are least likely to benefit from continued medical therapy alone, such as those with chronic rhinosinusitis subtypes that include, but are not limited to, chronic rhinosinusitis with polyps, polyps with bony erosion, eosinophilic mucin, or fungal balls (KAS 4). The surgeon or their designee should counsel patients before sinus surgery to establish realistic expectations, including the potential for chronicity or relapse, and the likelihood of long-term medical management, taking into account their chronic rhinosinusitis subtype (KAS 5). The surgeon should offer sinus surgery to an adult with chronic rhinosinusitis when the anticipated benefits exceed that of nonsurgical management alone, there is clarity regarding the anticipated outcomes, and the patient understands the expectation for long-term disease management following surgery (KAS 6). For an adult who is a candidate for sinus surgery, the surgeon or their designee should obtain a computed tomography (CT) scan with a fine-cut protocol, if not already available, to examine the paranasal sinuses for surgical planning (KAS 7). The surgeon should not plan the extent of sinus surgery (eg, which specific sinuses to operate on) solely based on arbitrary criteria regarding a minimal level of mucosal thickening, sinus opacification, or outflow obstruction on a CT scan (KAS 8). The surgeon or their designee should educate an adult with chronic rhinosinusitis who is scheduled for sinus surgery regarding anticipated postoperative care, specifically pain control, debridement, medical management, activity restrictions, return to work, duration and frequency of follow-up visits, and the potential for recurrent disease or revision surgery (KAS 9). When the sinus involves polyps, osteitis, bony erosion, or fungal disease in an adult with chronic rhinosinusitis who is scheduled for sinus surgery, the surgeon should perform sinus surgery that includes full exposure of the sinus cavity (lumen) and removal of diseased tissue, not just balloon or manual ostial dilation, or refer the patient to a surgeon who can perform this extent of surgery (KAS 10). The surgeon or their designee should routinely follow up to assess and document outcomes of sinus surgery for chronic rhinosinusitis, between 3 and 12 months after the procedure, through history (symptom relief, quality of life, complications, adherence to therapy, need for rescue medications, and ongoing care) and nasal endoscopy (KAS 11). There were no recommendations that were considered options from the Guideline Development Group.

Intrapolyp Steroid Injection for Nasal Polyposis: A Systematic Review and Network Meta-Analysis

OBJECTIVE

To conduct a systematic review and network meta-analysis to evaluate the safety and efficacy of intrapolyp steroid injection compared with oral steroids, nasal steroid wash, nasal steroid spray, and a control group in patients with chronic rhinosinusitis with nasal polyps (CRSwNP).

DATA SOURCES

PubMed, Scopus, Web of Science, Embase, and CENTRAL.

REVIEW METHODS

Both randomized and non-randomized clinical trials were included. For risk of bias assessment, we used the RoB-2 and ROBINS-I tools. Our outcomes focused on safety and efficacy, including rates of visual disturbance and bleeding, as well as improvements in nasal polyps evaluated through three domains: endoscopic, radiologic, and patient-reported assessments. Safety data were pooled as events (%), while efficacy data were pooled as mean difference (MD) or standardized mean difference (SMD).

RESULTS

Eight clinical trials involving 579 patients were analyzed. The pooled analyses showed low event rates for visual disturbances (event rate = 0.64%, 95% CI [0.00%, 2.23%]) and bleeding (event rate = 0.61%, 95% CI [0.00%, 2.25%]). Additionally, intrapolyp steroid injections were found to be comparable with oral steroids, with no statistically significant differences. Moreover, intrapolyp steroid injections demonstrated some superiority over nasal sprays, nasal washes, and the control group.

CONCLUSION

This network meta-analysis confirms that intrapolyp steroid injections have a favorable safety and efficacy profile as a viable management option for CRSwNP. The injections showed comparable efficacy with oral steroids and demonstrated certain advantages over other treatments, such as nasal sprays and washes. Further research with larger sample sizes and standardized protocols are needed. Laryngoscope, 135:1872-1883, 2025.

siHIF-1α-loaded micellar nanoparticles inhibit M1 macrophage activation to ameliorate chronic rhinosinusitis

OBJECTIVE

To investigate the molecular mechanisms by which micellar nanoparticles loaded with small interfering RNA targeting hypoxia-inducible factor 1-alpha (MNP_siHIF-1α) modulate macrophage polarization and ferroptosis in chronic rhinosinusitis (CRS), offering a novel therapeutic approach to ameliorate chronic inflammation and immune dysregulation in CRS.

METHODS

Transcriptomic analysis of the GSE10406 dataset identified 3821 differentially expressed genes (DEGs) in CRS, with functional enrichment via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Single-cell RNA sequencing (scRNA-seq) using the Seurat package characterized cellular heterogeneity in nasal mucosal tissues of CRS mice. In vitro, Raw264.7 macrophages were transfected with lentiviral sh-HIF-1α or oe-TFRC constructs, followed by RT-qPCR, chromatin immunoprecipitation (ChIP), dual-luciferase assays, and flow cytometry to assess HIF-1α-TFRC interactions, ROS accumulation, and M1 polarization. MNP_siHIF-1α, prepared using PCL-PEG/PPEEA diblock copolymers, was characterized via dynamic light scattering (DLS) and gel retardation assays. In vivo, CRS mice received intranasal MNP_siHIF-1α (10 mg/mL, 20 μL, thrice weekly for 4 weeks), with histopathological and inflammatory outcomes evaluated by H&E staining, immunohistochemistry, and ELISA.

RESULTS

HIF-1α was significantly upregulated in CRS tissues (p < 0.05) and activated TFRC transcription by binding its promoter, driving M1 macrophage polarization (↑NOS2, IL-6, IL-1β; p < 0.05) and ferroptosis (↑MDA, Fe2+; p < 0.05). Silencing HIF-1α reduced TFRC expression (↓42 %, p < 0.05), suppressed ROS levels (↓35 %, p < 0.05), and inhibited M1 polarization (↓50 % IL-6, p < 0.05). MNP_siHIF-1α (51.0 ± 2.3 nm, ζ-potential: +27.9 mV) achieved 95 % siRNA loading at N/P 5:1 and reduced nasal mucosal thickening (↓60 %, p < 0.01) and inflammatory cytokines (TNF-α: ↓45 %, p < 0.05) in CRS mice. Ferroptosis markers (GPX4: ↑2.1-fold, MDA: ↓55 %) confirmed therapeutic efficacy.

CONCLUSION

MNP_siHIF-1α suppresses the HIF-1α/TFRC-ROS axis, mitigates M1 macrophage-driven inflammation, and inhibits ferroptosis, significantly alleviating CRS progression. This study underscores the potential of nanotechnology-based siRNA delivery as a precision therapy for CRS, though further validation of long-term safety and clinical translation is warranted.

Biyuantong decoction improves chronic rhinosinusitis by inhibiting inflammatory cell adhesion via NF-кB pathway modulation

ETHNOPHARMACOLOGICAL RELEVANCE

Biyuantong decoction (BYT), a traditional Chinese medicinal formulation, has been used for years to treat chronic rhinosinusitis (CRS) with good clinical results. However, the underlying mechanisms of its treatment for CRS remain to be fully elucidated.

STUDY AIM

This research investigates the molecular mechanism by which BYT ameliorates CRS and provide new perspectives for CRS treatment research.

MATERIALS AND METHODS

Clinical research is conducted on CRS patients who underwent surgery, and post-operative treatments and observations were performed. The pathological alterations of CRS were inspected by H&E staining and nasal endoscopy. Flow cytometry and ELISA were employed to measure the levels of inflammatory cells and cytokines in the peripheral blood of CRS patients. The cytotoxic impacts of BYT were assessed by cell viability, cell cycle and apoptosis assays. The effects of BYT on the adhesion and invasion of inflammatory cells to endothelial cells were evaluated by hetero-adhesion and transwell assay. Flow cytometry was employed to analyze the expression of cell adhesion molecules (CAMs) on HUVECs. The effects of BYT on NF-κB signaling pathway was analyzed by Western blot and immunofluorescence staining. The chemical components of BYT was determined by UPLC-HRMS, and network pharmacology analysis was adopted to predict potential targets in the NF-κB pathway.

RESULTS

Clinical samples demonstrated that BYT treatment could effectively alleviate sinus mucosal edema and significantly decreased the recurrence rate after surgery. H&E staining disclosed obvious inflammatory cell infiltration in the sinus mucosa of CRS patients. Flow cytometry and ELISA results indicated that BYT treatment reduced the levels of eosinophils (median decrease 16.21 %) and cytokines in peripheral blood. Cell adhesion and transwell assays manifested that BYT inhibited the adhesion and invasion of U937 cells to TNF-α-induced HUVECs. Moreover, BYT counteracted the TNF-α-induced upregulation of CAMs on endothelial cells. Western blot and immunofluorescence analyses confirmed that BYT reduced the expression of NF-κB-related proteins and hindered the nuclear translocation of NF-κB. Network pharmacology analysis and component identification of BYT further supported the function of its compounds in synergistically modulating NF-κB signaling.

CONCLUSION

BYT enhances the clinical efficacy of CRS by suppressing inflammatory cell adhesion and infiltration into the nasal mucosa via NF-кB pathway regulation. These findings provide a robust foundation for the clinical application of BYT in CRS treatment and suggest interrupting inflammatory cell adhesion as a potential new approach.

Epithelial cell dynamics: Key drivers of type 2 inflammation in eosinophilic chronic rhinosinusitis

Sinonasal mucosal epithelial cells act not only as a physical barrier, but also as dynamic regulators of immune responses through innate and acquired immunity. These cells play a key role in detecting environmental stimuli, such as pathogens, allergens, and pollutants, and in initiating the inflammatory cascade that shapes the overall immune response. By releasing cytokines, such as interleukin (IL)-25 and IL-33, and thymic stromal lymphopoietin, epithelial cells interact with immune cells and promote type 2 inflammation. The pathogenesis of eosinophilic chronic rhinosinusitis (ECRS), which is driven by type 2 inflammation, is heterogeneous. While immune cells have traditionally been considered to be central to the disease pathogenesis, emerging evidence has indicated the critical role of epithelial cells. Furthermore, novel biologics targeting the IL-4/IL-13 signaling pathway have shown potential in alleviating epithelial dysfunction and inflammation. Eosinophilic mucins that accumulate in the sinuses impair mucociliary function, and especially eosinophil extracellular trap cell death (EETosis) stimulate epithelial cells and amplify eosinophilic inflammation. Eosinophilic mucin formation has been shown to significantly increase viscosity through EETosis, and novel biologics targeting the IL-5 signaling pathway hold promise for effectively mitigating this process. To develop targeted interventions, it is important to explore the role of epithelial subpopulations, such as basal cells and tuft cells, in maintaining the balance between tissue repair and chronic inflammation. Single-cell transcriptomics and spatial transcriptomics technologies have provided significant insights into the complexity of epithelial cell-derived inflammation in ECRS. The heterogeneity of the pathogenesis of CRS with nasal polyps and ECRS across patient populations complicates the development of universal therapies, underscoring the need for stratified medicine approaches. Potential future therapeutic strategies include the restoration of epithelial integrity and immune balance by disrupting aberrant crosstalk between epithelial and immune cells, particularly in patients unresponsive to current treatments.

IL-13 May Could Enhance the Proliferation and Affect the Differentiation of Nasal Epithelium Basal Cells Through the mTOR/p70S6K1 Pathway in Chronic Rhinosinusitis With Nasal Polyps

Background: One of the hallmarks of Chronic rhinosinusitis with nasal polyps (CRSwNP) is the overexpression of IL-13, which may influence the proliferation and differentiation of nasal epithelial basal cells. However, the pathway is not clear enough, and the mTOR/p70S6K1 pathway is related to cell growth. This study was trying to explore if IL-13 could impact nasal epithelial basal cells through the mTOR/p70S6K1 pathway. Methods: PCR, western blot (WB), and immunohistochemistry (IHC) were used to compare the difference between IL-13 and the mTOR/p70S6K1 pathway-related molecules expression level between the healthy control (HC) and CRSwNP groups. WB, 5-ethynyl-2'-deoxyuridine staining, and Immunofluorescent (IF) were performed on human nasal epithelial progenitor cells (HNEPCs) to detect the proliferation ability under the effect of IL-13. In addition, qRT-PCR, WB, and IF were used to detect the differentiation ability with the stimulation of IL-13 in the air-liquid interface (ALI) system. Results: The expression of IL-13, mTOR/p70S6K1-related molecules, and proliferation-related molecules Ki67, CDK2, and cyclin E1 were upregulated in CRSwNP compared to HC. In HNEPCs, IL-13 could stimulate nasal epithelial cells proliferating through the mTOR/p70S6K1 pathway, and this phenomenon could be inhibited when mTOR (with rapamycin) and S6K1 (with PF-4708671) were blocked. In the ALI system, the effect of IL-13 added in the proliferation phase could persist in the proliferation and differentiation stage, affecting the nasal epithelial progenitor/stem cells' irregular differentiation. Conclusion: IL-13 may affect the proliferation and differentiation of nasal epithelial progenitor/stem cells through the mTOR/p70S6K1 pathway, which may affect the development of nasal polyps.

A long-term mixed eosinophilic and neutrophilic chronic rhinosinusitis C57BL/6 mouse model with neuroinflammation, olfactory dysfunction and anxiety-like behaviors

BACKGROUND

Chronic rhinosinusitis (CRS) is a heterogeneous condition characterized by persistent inflammation and high recurrence rates. The mixed granulocytic endotype, marked by increased eosinophils and neutrophils, is particularly refractory and prone to relapse.

OBJECTIVE

This study aimed to evaluate the papain-induced mouse model for investigating the more refractory mixed granulocytic CRS endotype, characterized by elevated eosinophils and neutrophils.

METHODS

Male C57BL/6 mice were intranasally administered papain for 11 days to induce CRS. Cytokine profiles, nasal tissue histology, olfactory bulb analysis, assessments of olfactory function, cognition, anxiety-like and depression-like behaviors were performed at 30, 60, and 90 days post-treatment.

RESULTS

A long-term mixed eosinophilic and neutrophilic CRS model was successfully established, showing elevated IgE, IL-4, IL-5, IL-13, IL-33, TSLP, and TNF-α in nasal lavage fluid, alongside infiltration of eosinophils and neutrophils in both olfactory and respiratory regions. Chronic pathology included increased mast cells, goblet cells, basal cells, mucus hyperproduction, and epithelial damage, persisting up to 90 days, with partial improvement observed at the 60-day mark. Brain analysis revealed ongoing neuroinflammation, olfactory dysfunction, and anxiety-like behaviors in CRS mice, without signs of cognitive impairment or depression-like behaviors.

CONCLUSIONS

This study phenotypically delineated a long-term mixed eosinophilic and neutrophilic CRS mouse model, demonstrating sustained neuroinflammation, olfactory dysfunction, and anxiety-like behaviors following short-term papain exposure. These findings highlighted the role of mixed inflammation in CRS and provided a time-efficient platform for further exploration of its pathogenesis and mind-brain-body interactions.

Hypoxia-reduced YAP phosphorylation enhances expression of Mucin5AC in nasal epithelial cells of chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is an upper respiratory disease characterized by persistent inflammation of the nasal mucosa. However, the mechanism of abnormal Mucin5AC expression by CRSwNP epithelial cells is not fully understood.

OBJECTIVE

We investigated the potential role of yes-associated protein (YAP) underlying the mechanism of excessive epithelial Mucin5AC expression in CRSwNP in a hypoxic model.

METHODS

Tissue biopsies of CRSwNP (n = 60), chronic rhinosinusitis without nasal polyps (CRSsNP) (n = 9) and healthy controls (n = 30) were investigated together with a well-established hypoxic model of primary human nasal epithelial cells (hNECs). The expression levels of hypoxia inducible factor (HIF)-1α and YAP, and the effect of the signaling axis on mucus secretion in hNECs were analyzed.

RESULTS

We observed a significant elevated expression levels of YAP in patients with CRSwNP and CRSsNP compared to controls. In addition, HIF-1α expression of CRSwNP was higher than that of control group. Under hypoxic conditions, HIF-1α was found to regulate the upregulation of YAP in hNECs. Further investigations revealed that HIF-1α facilitated the activation and nuclear localization of active-YAP by reducing the phosphorylation of YAP. This mechanism appeared to be linked to HIF-1α-mediated inhibition of LATS 1 phosphorylation and subsequent YAP degradation. HIF-1α was shown to promote the expression of P63 and the levels of Mucin5AC in hNECs by enhancing YAP activation.

CONCLUSION

Our findings indicated that hypoxia enhances YAP activation by decreasing p-LATS 1 and YAP phosphorylation. This has the potential to impact on the proliferation of basal cells and the differentiation of goblet cells in CRSwNP, ultimately leading to a pathological condition characterized by excessive Mucin5AC expression.

Obesity: Next game changer of allergic airway diseases?

Obesity and allergic diseases are global health concerns, both of which are seeing an increase in prevalence in recent years. Obesity has been recognised as an important comorbidity in subpopulations with allergic airway diseases, which represents a unique phenotype and endotype. Obesity-related allergic airway diseases are associated with exacerbated clinical symptom burden, altered immune response, increased disease severity and compromised predictive capability of conventional biomarkers for evaluating endotype and prognosis. Moreover, treatment of obesity-related allergic airway diseases is challenging because this unique endotype and phenotype is associated with poor response to standard therapeutic strategies. Therapeutic regimen that involves weight loss by non-surgical and surgical interventions, gut microbiome-targeted treatment, glucagon-like peptide-1 receptor agonist and other agents should be considered in this population. In this review, we outline the current knowledge of the impact of obesity on prevalence, endotypes, clinical symptom and management of allergic airway diseases. Increased understanding of the implications of obesity may contribute to better treatment options for the obesity-related refractory airway inflammation, particularly in precision medicine. KEY POINTS: Obesity can increase the prevalence of allergic airway diseases such as asthma, AR, and CRSwNP. Obesity alters the immune endotype and exacerbates clinical symptoms of respiratory allergic diseases. Obesity-related allergic airway diseases exhibit therapeutic resistance to standard treatment. Obesity-related allergic airway diseases constitute a distinct category of endotypes and phenotypes, requiring further in-depth research and novel therapeutic approaches.

Age-related changes of inflammatory cytokines in nasal secretion of patients with chronic rhinosinusitis

BACKGROUND

Patient-specific factors are highly involved in chronic rhinosinusitis (CRS) 's course and treatment response. However, the effects of aging on the pathophysiology of CRS remain unclear. This study aimed to evaluate the age-related changes in nasal secretion inflammatory characteristics in patients with CRS.

METHODS

The levels of 12 inflammatory cytokines in nasal mucus samples obtained from 31 patients diagnosed with CRS were measured via enzyme-linked immunosorbent assays. The associations between age and inflammatory cytokine levels were determined by Spearman correlation coefficient analysis. In addition, the relationships between inflammatory markers and demographic evaluation variables such as the Sino-Nasal Outcome Test-22 (SNOT-22) score and disease duration were examined to determine whether the levels of inflammatory cytokines influence the assessment of disease severity in CRS patients.

RESULTS

Compared to younger patients with CRS, aged CRS patients exhibited a significant reduction in IL-6 levels (p < 0.01), while levels of IL-10 (p < 0.01), IL-13 (p < 0.01), and Eotaxin (p < 0.05) were markedly elevated. Notably, the Eotaxin level demonstrated a significant decline with age among CRS patients younger than 60 years old (r = -0.79, p < 0.001). Furthermore, the increased mucus TNF-α level was significantly correlated with the prolongation of the disease course in aged CRS patients, with a clinically relevant difference of 7.78 months (p < 0.05).

CONCLUSION

We have revealed age-specific changes in the inflammatory characteristics of CRS patients, providing new and interesting findings for the development of personalized treatment methods tailored to this high-risk population.

Exploring the comorbidity association and biological mechanisms of chronic rhinosinusitis and chronic obstructive pulmonary disease

Although chronic rhinosinusitis (CRS) and chronic obstructive pulmonary disease (COPD) are both common chronic inflammatory diseases, the interaction between their comorbidities remains poorly understood within the unified airway disease framework. This study, for the first time, integrated multi-omics analysis and large-scale epidemiological data to explore their common mechanisms and clinical significance. The NHANES database was used for analysis, and multivariate logistic regression was employed to assess the comorbidity risk of CRS and COPD. Machine-learning models (glmnet, ranger, and xgboost) were used to analyze the NHANES data to determine the best model. Subsequently, Mendelian randomization(MR) was applied to explore relevant associations. Additionally, CRS and COPD datasets from GEO were further analyzed to identify potential targets. The NHANES analysis showed a significant association between CRS and COPD, with MR results indicating that CRS significantly increased the risk of COPD. Multi-omics integration revealed that C3 and CD163 are core targets in CRS/COPD patients. The ranger model was identified as the most suitable in this study. This study provides new evidence that CRS is an independent risk factor for COPD and establishes a unified airway mechanism centered on C3-CD163-mediated inflammation. These findings advance the "one airway, one disease" paradigm and support a dual-target therapeutic strategy.

Long-Term Particulate Matter Exposure May Increase Risk of Chronic Rhinosinusitis WIth Nasal Polyposis: Results from an Exposure-Matched Study

BACKGROUND

Particulate matter ⩽2.5 µm in diameter (PM2.5) and its role in chronic rhinosinusitis (CRS) pathogenesis have gained heightened attention. We previously demonstrated that PM2.5 exposure may bias the nasal mucosa in CRS toward a Type 2 inflammatory pathway. However, there are limited data comparing cytokine changes in CRS sinonasal tissue to non-CRS patients as it relates to PM2.5 exposure. We hypothesized that long-term exposure preferentially increases the risk of manifesting CRS with nasal polyposis (CRSwNP).

METHODS

We performed a retrospective analysis of 376 patients (308 CRS, 68 controls) who underwent endoscopic sinus or skull base surgery. A spatiotemporal machine-learning model estimated daily PM2.5 levels for 1 year prior to each patient's surgery date. Cytokines were quantified using a multiplex flow cytometric bead assay and compared to estimated PM2.5 exposure using Spearman correlation and multivariate regression. Patients with high and low 12-month PM2.5 exposures were matched across age, sex, income, and rurality using a nearest neighbor algorithm. Multivariate adjusted logistic regression was used to estimate the odds of CRS based on PM2.5 exposure.

RESULTS

Reduced IL-10 levels were associated with higher PM2.5 exposures in control patients (β = -0.735, p = 0.0196). In exposure-matched logistic regression analysis, high 12-month PM2.5 exposure was an independent predictor of CRSwNP (β = 1.97, OR: 7.22, p = 0.0001) after adjustment for age, income, rurality, and comorbid asthma/allergic rhinitis. A similar relationship was not identified for CRSsNP.

CONCLUSIONS

PM2.5 exposure is associated with reduced IL-10 in control patients compared to CRS and may increase odds of CRSwNP development.

Histopathologic features of chronic rhinosinusitis with nasal polyps in patients from high-altitude Xizang region

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous inflammatory disease with varying patterns across regions.

OBJECTIVE

This study aims to investigate the clinical and histopathological features of CRSwNP in Xizang, a high-altitude region in China.

MATERIALS AND METHODS

We retrospectively analyzed the histopathological features of CRSwNP patients from Shanghai and Xizang who underwent functional endoscopic sinus surgery (FESS) between 2017 and 2024. Polyp tissue samples were assessed, and statistical analyses compared features between the two regions in CRSwNP, eosinophilic CRSwNP (eCRSwNP), and noneosinophilic CRSwNP (neCRSwNP) patients.

RESULTS

Twenty-eight patients from Xizang and 35 from Shanghai were analyzed. All Shanghai patients were Han Chinese, and all Xizang patients were Tibetan. Compared to Shanghai, Tibetan patients had significantly lower rates of smoking and asthma. Overall inflammation levels in Xizang were lower, while eosinophil counts were lower in eCRSwNP patients. Neutrophil infiltration, mucosal ulceration, and squamous metaplasia were higher in Xizang patients, while neCRSwNP patients exhibited more neutrophil infiltration and less subepithelial edema.

CONCLUSIONS

The study revealed that Tibetan patients with CRSwNP have lower eosinophilic inflammation but higher neutrophil infiltration and squamous metaplasia compared to Shanghai patients, indicating the impact of high-altitude environments on inflammatory patterns.

Impact of Comorbid Asthma on Life Quality of Patients with Chronic Rhinosinusitis and Nasal Polyps

Objective

This study aimed to characterize the clinical features of patients with comorbid asthma and chronic rhinosinusitis with nasal polyps and to evaluate the impact of comorbid asthma on the quality of life of these patients.

Methods

Adult patients with bilateral chronic rhinosinusitis with nasal polyps scheduled for sinus surgery were prospectively enrolled. Clinical information of the participants, including laboratory data and computed tomography images. The Sinonasal Outcome Test-22 was used to evaluate nasal symptoms and quality of life impairment of participants.

Results

A total of 170 participants were recruited, of whom 32 (18.8%) had comorbid asthma. Compared to patients with chronic rhinosinusitis with nasal polyps and without comorbid asthma, patients with asthma exhibited significant higher age, computed tomography ethmoid/maxillary ratio, computed tomography olfactory cleft opacification score, serum total IgE, serum eosinophil cationic protein levels, and blood and tissue eosinophil count. Patients with comorbid chronic rhinosinusitis with nasal polyps and asthma exhibited significant higher total, and rhinologic- and sleep-related domains of the Sinonasal Outcome Test-22 than did those without comorbid asthma.

Conclusion

Comorbid asthma is associated with more severe type 2 eosinophilic inflammation and has a significant impact on the nasal symptoms and quality of life of patients with chronic rhinosinusitis with nasal polyps, particularly as shown in the rhinologic- and sleep-related domains of the Sinonasal Outcome Test-22. This information may assist physicians in decision-making when treating these patients.

The immunology of asthma and chronic rhinosinusitis

Asthma and chronic rhinosinusitis (CRS) are common chronic inflammatory diseases of the respiratory tract that have increased in prevalence over the past five decades. The clinical relationship between asthma and CRS has been well recognized, suggesting a common pathogenesis between these diseases. Both diseases are driven by complex airway epithelial cell and immune cell interactions that occur in response to environmental triggers such as allergens, microorganisms and irritants. Advances, including a growing understanding of the biology of the cells involved in the disease, the application of multiomics technologies and the performance of large-scale clinical studies, have led to a better understanding of the pathophysiology and heterogeneity of asthma and CRS. This research has promoted the concept that these diseases consist of several endotypes, in which airway epithelial cells, innate lymphoid cells, T cells, B cells, granulocytes and their mediators are distinctly involved in the immunopathology. Identification of the disease heterogeneity and immunological markers has also greatly improved the protocols for biologic therapies and the clinical outcomes in certain subsets of patients. However, many clinical and research questions remain. In this Review, we discuss recent advances in characterizing the immunological mechanisms of asthma and CRS, with a focus on the main cell types and molecules involved in these diseases.

The expression and significance of nasal mucosal glandular hyperplasia and eosinophil infiltration in chronic rhinosinusitis

BACKGROUND

The pathophysiological mechanisms underlying nasal mucosal glandular changes in chronic rhinosinusitis (CRS) remains poorly understood.

OBJECTIVES

This study aimed to examine nasal mucosal glandular density and eosinophil (Eos) infiltration in CRS patients and their role in disease pathogenesis.

MATERIALS AND METHODS

HE staining was used to assess glandular density and Eos infiltration in nasal mucosal lesion tissues from 86 CRS patients during FESS (16 CRS without nasal polyps (CRSsNP), 55 non-eosinophilic CRS with nasal polyps (nECRSwNP), and 15 eosinophilic CRSwNP (ECRSwNP)). Immunohistochemical analysis was conducted to evaluate eosinophil cationic protein (ECP), lysozyme, and immunoglobulin A (IgA) expression within these tissues. The Kruskal-Wallis test was used to reveal the statistical difference in therapeutic efficacy among the groups.

RESULTS

The CRSsNP group showed nasal mucosal glandular density of '+++/++' with minimal Eos infiltration, and 94% achieved control. The nECRSwNP group exhibited atypical glandular hyperplasia and Eos infiltration, with 22% achieving complete control, 51% partial control, and 27% no control. The ECRSwNP group had significant Eos infiltration '++/+++' and reduced glands, with 93% showing uncontrolled conditions.

CONCLUSIONS AND SIGNIFICANCE

The findings suggest that extensive Eos infiltration and ECP secretion contribute to glandular and epithelial damage, reducing lysozyme and IgA production. These changes may promote chronic inflammation and increase the likelihood of nasal polyp recurrence.

Biological therapy in chronic rhinosinusitis with nasal polyps

INTRODUCTION

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease. High proportions of patients with CRSwNP characterized by type 2 inflammation fail to gain adequate control with conventional treatment. The application of biologics in clinics and assessments of novel biologics in clinical trials are blooming in expectations to fulfill the unmet medical needs of patients with CRSwNP with type 2 inflammation.

AREAS COVERED

After an extensive search of PubMed, Medline, and EMBASE for the most recent evidence, we thoroughly summarize current advances in biological therapies for treating patients with CRSwNP.

EXPERT OPINION

In recent years, biological therapy has been in the spotlight in clinical studies on CRSwNP. Biologics have proven to be efficacious in reducing nasal polyp size, alleviating CRSwNP-related symptoms, improving quality of life, and reducing the need for systemic corticosteroids or endoscopic sinus surgery for nasal polyps. The considerable efficacy and safety profile of biologics has offered patients with refractory CRSwNP another treatment option. However, some concerns remain to be addressed. Aspects such as the position of biological therapy in the management of CRSwNP, traits of patients suitable for certain biologics, etc. necessitate efforts to elucidate these unknowns in order to provide patients with tailored therapy.

IRF4 Knockdown Inhibits the Chronic Rhinosinusitis Without Nasal Polyps Development by Regulating NLRP3/Caspase-1/GSDMD-Mediated Pyroptosis

Chronic rhinosinusitis without nasal polyps (CRSsNP) is a CRS phenotype. However, the mechanisms of CRSsNP remains unclear. Differentially expressed genes (DEGs) were obtained from the GSE36830 and GSE198950 datasets through the GEO2R tool. The six hub genes were screened by the protein-protein interaction (PPI) network analysis and Cytoscape software. Then we constructed the mouse models of CRS and verified the expression levels of hub genes by reverse transcription quantitative PCR (RT-qPCR). Hematoxylin-eosin (HE) staining was employed to observe pathological alterations in mouse tissues. Casepase-3 expression was detected by immunohistochemistry (IHC). The levels of TNF-α, IL-12, IL-6, IL-1β, LDH, and IL-18 were evaluated using enzyme-linked immunosorbent assay (ELISA). Pyroptosis-related protein expressions were measured by western blotting. Cell counting kit-8 (CCK-8) and flow cytometry were performed to assess the proliferation and apoptosis of lipopolysaccharide (LPS)-induced NP69 cells. Six hub DEGs were identified. The expression levels of IRF4, IKZF1, and CD79A were obviously increased in CRSsNP, while those of ADH6, ADH1A, and LDHC were significantly decreased. IRF4 knockdown attenuated the pathologic features of CRSsNP. IRF4 knockdown reduced levels of the TNF-α, IL-12, IL-6 IL-1β, LDH, and IL-18 as well as the proteins expression of Casepase-1, GSDMD, and NLRP3 both in vivo and in vitro, implying that inflammation and pyroptosis were inhibited. IRF4 knockdown hinders the development of CRSsNP by inhibiting the inflammatory response and NLRP3/Caspase-1/GSDMD-mediated pyroptosis, which offers novel promising treatment strategies for clinical intervention.

Tezepelumab in Adults with Severe Chronic Rhinosinusitis with Nasal Polyps

BACKGROUND

Treatment with tezepelumab has been effective for sinonasal symptoms in patients with severe, uncontrolled asthma and a history of chronic rhinosinusitis with nasal polyps, but its efficacy and safety in adults with severe, uncontrolled chronic rhinosinusitis with nasal polyps is unknown.

METHODS

We randomly assigned adults with physician-diagnosed, symptomatic, severe chronic rhinosinusitis with nasal polyps to receive standard care and either tezepelumab (at a dose of 210 mg) or placebo subcutaneously every 4 weeks for 52 weeks. The coprimary end points were the changes from baseline in the total nasal-polyp score (range, 0 to 4 [for each nostril]; higher scores indicate greater severity) and the mean nasal-congestion score (range, 0 to 3; higher scores indicate greater severity) at week 52. Key secondary end points assessed in the overall population were the loss-of-smell score, the total score on the Sinonasal Outcome Test (SNOT-22; range, 0 to 110; higher scores indicate greater severity), the Lund-Mackay score (range, 0 to 24; higher scores indicate greater severity), the total symptom score (range, 0 to 24; higher scores indicate greater severity), and the first decision to treat with nasal-polyp surgery or use of systemic glucocorticoid therapy, or both, assessed in time-to-event analyses (individual and composite).

RESULTS

In total, 203 patients were assigned to receive tezepelumab and 205 to receive placebo. At week 52, the patients who received tezepelumab had significant improvements in the total nasal-polyp score (mean difference vs. placebo, -2.07; 95% confidence interval [CI], -2.39 to -1.74) and the mean nasal-congestion score (-1.03; 95% CI, -1.20 to -0.86) (P<0.001 for both scores). Tezepelumab significantly improved the loss-of-smell score (mean difference vs. placebo, -1.00; 95% CI, -1.18 to -0.83), SNOT-22 total score (-27.26; 95% CI, -32.32 to -22.21), Lund-Mackay score (-5.72; 95% CI, -6.39 to -5.06), and total symptom score (-6.89; 95% CI, -8.02 to -5.76) (P<0.001 for all scores). Surgery for nasal polyps was indicated in significantly fewer patients in the tezepelumab group (0.5%) than in the placebo group (22.1%) (hazard ratio, 0.02; 95% CI, 0.00 to 0.09); there was significantly less use of systemic glucocorticoids with tezepelumab (5.2%) than with placebo (18.3%) (hazard ratio, 0.12; 95% CI, 0.04 to 0.27) (P<0.001 for both time-to-event analyses).

CONCLUSIONS

Tezepelumab therapy led to significantly greater reductions in the size of nasal polyps, the severity of nasal congestion and sinonasal symptoms, and the use of nasal-polyp surgery and systemic glucocorticoids than placebo in adults with severe, uncontrolled chronic rhinosinusitis with nasal polyps. (Funded by AstraZeneca and Amgen; WAYPOINT ClinicalTrials.gov number, NCT04851964.).

Identification of DIO2 as a Molecular Therapeutic Target for Depression in Chronic Rhinosinusitis: A Comprehensive Bioinformatics and Experimental Study

Chronic rhinosinusitis (CRS) and depression are both common conditions with significant socioeconomic impact. The high co-occurrence of depression in CRS patients suggests a common pathophysiology, but the mechanisms are unclear. This study aimed to identify potential molecular links between the two conditions. We retrieved gene expression datasets for CRS and depression from the GEO database. Using differentially expressed genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA), we identified co-expression genes associated with CRS and depression. Enrichment analyses including GO, KEGG, and GSEA were performed to explore biological pathways. Machine learning algorithms including random forest and LASSO regression were engaged to screen for shared hub genes predictive of CRS and depression. Single-cell RNA sequencing (scRNA-seq) data were analyzed to delineate the expression profiles of the shared hub genes across different cell types. Animal experiments were employed to validate the role of core genes in CRS-related depression. We identified five shared hub genes: CHRDL1, DIO2, HSD17B6, PDE3A, and PLA2G5, with the TGF-β signaling, cytokine-cytokine interaction receptors, and cell adhesion as key biological pathways. DIO2, as identified by machine learning, is a promising diagnostic biomarker for CRS and depression. The scRNA-seq analysis showed that DIO2 is primarily expressed in neurons and astrocytes. Animal experiments showed that overexpression of DIO2 improved the depressive-like behaviors in CRS mice. This study sheds new light on the molecular basis of the comorbidity between CRS and depression. DIO2 is a potential diagnostic and therapeutic target for CRS patients with comorbid depression.

The Role of the Environment and Occupational Exposures in Chronic Rhinosinusitis

PURPOSE OF REVIEW

The purpose of the review is to summarize the current literature and evaluate how different environmental exposures may contribute to the development and course of chronic rhinosinusitis (CRS). The review aims to explore the relationship between host factors and environmental exposures in the pathogenesis of CRS.

RECENT FINDINGS

Recent studies have helped establish the role of air pollutants, tobacco smoke, occupational exposures, and microplastics in the pathogenesis of CRS. These exposures have been shown to cause epithelial dysfunction and promote inflammation through different mechanisms and to different degrees. The pathogenesis of CRS is complex and multifactorial, with environmental exposures playing a key role in its onset and exacerbation. Research indicates that pollutants can damage the sinonasal epithelial barrier and disrupt the microbiome, leading to increased inflammation. A deeper understanding of the mechanisms behind this inflammatory process and its link to environmental exposures could enhance strategies for preventing and treating CRS.

Ambient particulate matter and frequency of outpatient visits for chronic rhinosinusitis in the United States

BACKGROUND

Emerging evidence has underscored the harmful effects of air pollution on the upper airway. We investigated the relationship between ambient particulate matter (PM) level and the frequency of outpatient visits for chronic rhinosinusitis (CRS).

METHODS

We conducted an ecological cohort study of US adults enrolled in The Merative MarketScan outpatient database from 2007 to 2020. For each geographical subunit (core-based statistical area [CBSA]), we calculated the annual rate of CRS-related outpatient visits per 1000 well-patient checkup visits (CRS-OV). Using data from the Environmental Protection Agency's Air Quality System, we mapped the rolling statistical average of daily PM2.5 and PM10 over the preceding year onto each CBSA × year combination. We employed multivariable negative binomial regression modeling to estimate the association between PM levels and subsequent CRS-OV.

RESULTS

Across 3933 observations (CBSA × year combinations), encompassing ∼4 billion visits, the median CRS-OV was 164 (interquartile range 110-267). The mean PM2.5 level was 8.9 µg/m3 (SD 2.6) and the mean PM10 level was 20.2 µg/m3 (SD 7.2). Adjusting for patient demographics and respiratory comorbidities, a compounded rise in subsequent CRS-OV was observed with increasing PM levels. Each µg/m3 rise in PM2.5 independently predicted a 10% increase in CRS-OV (adjusted incidence rate ratio [aIRR]) 1.10, 95% confidence interval [CI] 1.08-1.13) and each µg/m3 rise in PM10 independently predicted a 3% increase in CRS-OV (aIRR 1.03, 95% CI 1.02-1.04).

CONCLUSION

Elevated ambient PM2.5 and PM10 levels are associated with a subsequent compounded increase in the frequency of CRS-OV, with PM2.5 predicting a more pronounced rise compared to PM10.

Enlarged Frontal Sinusotomy and Chronic Rhinosinusitis with Nasal Polyps: An Effective Strategy to Control the Disease

INTRODUCTION

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a disease with a strong impact on the quality of life (QoL) which treatment is based on local intranasal corticosteroids (ICS) and iterative courses of systemic corticosteroids (SCS) in case of relapse. When medical treatment is insufficient, surgery is indicated. We investigated the impact of enlarged frontal sinusotomies (EFS: Draf IIb or Draf III) on QoL and annual SCS consumption of patients with severe uncontrolled CRSwNP.

METHODS

This is a retrospective cohort study of 38 patients, who underwent EFS at Lariboisière University Hospital (CHU) in Paris, France, between 2006 and 2020. All patients were asked to complete SNOT-22 questionnaires concerning pre- and post-op status. Patients' medical and sinus surgery history as well as the number of SCS treatments per year before and after surgery were also collected.

RESULTS

Of the 38 patients, 33 underwent a Draf III procedure and 5 a Draf IIb, with no major complications reported. Surgery resulted in a significant improvement in SNOT-22 scores (-32.7 ± 19.3, P < 0.001), with 19/22 items improving significantly. The number of annual SCS treatments decreased significantly from a mean of 4.8 ± 4.3 to 0.6 ± 1.2 (P < 0.001). During the follow-up (mean 88 months), 95% of our patients showed a satisfying disease control and only 2 patients required revision surgery for poor disease control 5 years after EFS.

CONCLUSION

EFS appears to be an effective and durable therapeutic option to improve the QoL of patients with severe CRSwNP and to reduce their SCS consumption without major complications.

Type 2 immunity in allergic diseases

Significant advancements have been made in understanding the cellular and molecular mechanisms of type 2 immunity in allergic diseases such as asthma, allergic rhinitis, chronic rhinosinusitis, eosinophilic esophagitis (EoE), food and drug allergies, and atopic dermatitis (AD). Type 2 immunity has evolved to protect against parasitic diseases and toxins, plays a role in the expulsion of parasites and larvae from inner tissues to the lumen and outside the body, maintains microbe-rich skin and mucosal epithelial barriers and counterbalances the type 1 immune response and its destructive effects. During the development of a type 2 immune response, an innate immune response initiates starting from epithelial cells and innate lymphoid cells (ILCs), including dendritic cells and macrophages, and translates to adaptive T and B-cell immunity, particularly IgE antibody production. Eosinophils, mast cells and basophils have effects on effector functions. Cytokines from ILC2s and CD4+ helper type 2 (Th2) cells, CD8 + T cells, and NK-T cells, along with myeloid cells, including IL-4, IL-5, IL-9, and IL-13, initiate and sustain allergic inflammation via T cell cells, eosinophils, and ILC2s; promote IgE class switching; and open the epithelial barrier. Epithelial cell activation, alarmin release and barrier dysfunction are key in the development of not only allergic diseases but also many other systemic diseases. Recent biologics targeting the pathways and effector functions of IL4/IL13, IL-5, and IgE have shown promising results for almost all ages, although some patients with severe allergic diseases do not respond to these therapies, highlighting the unmet need for a more detailed and personalized approach.

New insights into the endotypes of chronic rhinosinusitis in the biologic era

Chronic rhinosinusitis (CRS) exhibits significant heterogeneity and has been generally classified as type 1 (T1), T2, and T3 endotypes according to the histopathologic and inflammatory features of the nasal mucosa. T2 inflammation has been regarded as the predominant endotype of CRS linked to disease severity and refractory conditions. The development of biological agents that specifically target key molecules involved in T2 inflammation offers a highly effective and promising therapeutic approach for CRS. Recent findings have expanded the understanding of CRS endotypes by incorporating a range of disease-related molecules for classification, with progress made on the endotyping of CRS without nasal polyps. In addition, there has been an increasing emphasis on the study of mixed inflammatory endotypes. This review examines recent findings on CRS endotyping and the related noninvasive biomarkers, as well as novel mechanisms governing endotype formation, and addresses the efficacy of biologics in targeting T2 inflammation. Further research is warranted to understand if newly identified CRS endotypes show clinical significance for precision medicine and the management and treatment of refractory CRS in the era of biologics.

Supramolecular gel with enhanced immunomodulatory effects presents a minimally invasive treatment strategy for eosinophilic chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is an inflammatory disease characterized by persistent immune dysregulation, which presents considerable limitations in current medical therapy.

OBJECTS

This study investigates a supramolecular gel (PSPD), which aims to minimize systemic adverse effects through local injection, provide long-lasting anti-inflammatory effects, and modulate the mucosal immune microenvironment.

METHODS

The properties of PSPD were evaluated using rheological experiments. Biocompatibility assessments were conducted through CCK-8 and serum biochemical analyses. The balance between TH17 and Treg was determined using immunofluorescence (IF) and flow cytometry (FC). Additionally, sinus computed tomography (CT), and endoscopy were employed to evaluate mucosal swelling.

RESULTS

Rheological assessments revealed that PSPD possesses excellent self-healing and slow-release properties. CCK-8 and serum biochemical assays indicated that PSPD demonstrated superior biocompatibility. In nasal polyps, PSPD significantly inhibited IL17 expression. In an Eosinophilic Chronic Rhinosinusitis (ECRS) rat model, treatment with PSPD led to significant alleviation of nasal mucosal congestion. Furthermore, PSPD modulated the proliferation of TH17 and Treg as well as the expression of cytokines, ultimately reversing the TH17/Treg immune imbalance.

CONCLUSION

This multifunctional gel effectively sustains the modulation of TH17/Treg homeostasis, improving long-term disease management and representing a promising new therapeutic strategy for CRS, particularly in cases of ECRS.

A Longitudinal Study Examining the Impact of Chronic Rhinosinusitis on the Risk of Cancer Development: A National Population-Based Cohort Study

BACKGROUND/OBJECTIVES

We investigated the association between chronic rhinosinusitis (CRS) and cancer risk in an adult Korean population.

METHODS

This retrospective cohort study used data from the Korean National Health Insurance Service database. To ensure comparability between the groups, adjustments were made for potential confounding factors, including sex, age, residence, household income, diabetes, hypertension, and chronic kidney disease. The primary endpoint was the presence of newly diagnosed cancer.

RESULTS

Among 1,337,120 individuals in the nationally representative cohort database, 10,567 patients with CRS were identified and matched with 42,268 control subjects without CRS. Patients with CRS had a significantly higher risk of overall cancer events than controls. The adjusted hazard ratio (HR) for cancer in the CRS group was 1.16 (95% confidence interval [CI]: 1.05-1.28). Notably, female patients with CRS had an elevated risk of incident cancer events. Furthermore, patients with CRS without nasal polyps exhibited a significantly increased risk of cancer, whereas those with CRS with nasal polyps did not show a similar association.

CONCLUSIONS

These findings underscore the need for physicians to carefully monitor patients with CRS for potential cancer progression and develop appropriate therapeutic strategies to mitigate the impact of this condition.

[Morphogenesis and molecular regulation of polyposis rhinosinusitis]

Polyposis rhinosinusitis (CRSwNP) is a heterogeneous proliferative disease characterized by inflammatory hyperplasia of the nasal mucosa with dysregulation of apoptosis and cell differentiation. The review summarizes data on the molecular cellular mechanisms of CRSwNP and presents the concept of intercellular signaling during polyposis growth. Various factors that form a specific endotype are involved in the development of a polyp. Features of morphogenesis make it possible to distinguish edematous, eosinophilic and fibrous NP. In all cases, markers of neurogenic inflammation, impaired expression of proinflammatory cytokines, NO synthase, BMP-2 and other morphogenetic molecules arerecorded. The growing polyp and the inflammatory reaction damage the epithelium of the mucous membrane and bone wall of the nasal cavity. Interleukin-1β and BMP-2 are an integrative link in the pathogenesis of these events.

Correlation between Lund-Mackay computed tomography score and subjective symptoms in Chinese patients with nasal polyps

BACKGROUND

The association between objective imaging findings and subjective symptoms remains undefined.

AIMS

To investigate the correlation between objective imaging findings and symptom severity in the overall chronic rhinosinusitis with nasal polyps (CRSwNP) population as well as its subendotypes according to the eosinophilic inflammation.

METHODS

Patients with CRSwNP undergoing endoscopic sinus surgery were included. All participants completed the Sino-Nasal Outcome Test (SNOT-22) questionnaire. The Lund-Mackay (LM) CT scores was also obtained. Spearman correlation analysis was performed to evaluate the correlation between CT scores and SNOT-22 scores.

RESULTS

Forty-four non-eosinophilic CRSwNP(neCRSwNP) and 93 eosinophilic CRSwNP (eCRSwNP) patients were recruited. There was significant association between LM total score and nasal subdomain of SNOT-22 in the overall CRSwNP patients. The nasal symptom of SNOT-22 was significantly associated with maxillary, frontal, sphenoid, anterior drainage, and posterior drainage in all CRSwNP patients. In eCRSwNP and neCRSwNP patients, the sense of smell/taste was associated with sphenoid and posterior drainage. Thick nasal discharge was positively correlated with maxillary, frontal, and anterior drainage only in eCRSwNP patients.

CONCLUSIONS

The high score of sphenoid and posterior drainage may suggest the occurrence of loss of sense of smell/taste, while high score of maxillary sinus may indicate suffering from thick nasal discharge in eCRSwNP patients.

Food Allergy Genetics and Epigenetics: A Review of Genome-Wide Association Studies

In this review, we provide an overview of food allergy genetics and epigenetics aimed at clinicians and researchers. This includes a brief review of the current understanding of genetic and epigenetic mechanisms, inheritance of food allergy, as well as a discussion of advantages and limitations of the different types of studies in genetic research. We specifically focus on the results of genome-wide association studies in food allergy, which have identified 16 genetic variants that reach genome-wide significance, many of which overlap with other allergic diseases, including asthma, atopic dermatitis, and allergic rhinitis. Identified genes for food allergy are mainly involved in epithelial barrier function (e.g., FLG, SERPINB7) and immune function (e.g., HLA, IL4). Epigenome-wide significant findings at 32 loci are also summarized as well as 14 additional loci with significance at a false discovery of < 1 × 10-4. Integration of epigenetic and genetic data is discussed in the context of disease mechanisms, many of which are shared with other allergic diseases. The potential utility of genetic and epigenetic discoveries is deliberated. In the future, genetic and epigenetic markers may offer ways to predict the presence or absence of clinical IgE-mediated food allergy among sensitized individuals, likelihood of development of natural tolerance, and response to immunotherapy.

Anti-IgE therapy in chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory condition characterized by type 2 (T2) immune responses with significant impacts on quality of life and health care costs. Local IgE production in nasal polyp tissue plays a key role in the T2 inflammatory cascade. Omalizumab, an anti-IgE monoclonal antibody, is an effective treatment for some patients with CRSwNP regardless of the patient's allergic status. Clinical trials, including the pivotal POLYP 1 and POLYP 2 studies, demonstrated omalizumab's efficacy in reducing nasal polyp size, improving symptom scores, and enhancing quality of life, particularly in patients with comorbid asthma and aspirin-exacerbated respiratory disease. As we summarize in this review, omalizumab's effect appears to involve the reduction in local IgE and T2 inflammation; however, this remains poorly understood. Notably, omalizumab's effectiveness appears to be partially sustained after long-term therapy, though symptoms and inflammation begin to return at discontinuation. Ongoing research is needed to determine the optimal duration of therapy and potential for biologics to modify the disease course. Additionally, further studies are needed to identify biomarkers to predict treatment response and to compare omalizumab with other biologics such as dupilumab in head-to-head trials. Omalizumab is one of the key T2-targeted therapeutic options for CRSwNP, with sustained effectiveness and strong safety profile.

FERMT1 contributes to the epithelial-mesenchymal transition of chronic rhinosinusitis with nasal polyps via PI3K/Akt signaling

BACKGROUND

Epithelial-mesenchymal transition (EMT) is a key process of chronic rhinosinusitis with nasal polyps (CRSwNP). The molecular mechanism of EMT in CRSwNP remains unknown. In this study, we aimed to investigate the role of FERMT1 during the EMT process in CRSwNP.

METHODS

Western blotting, qRT-PCR, and immunohistochemistry (IHC) were performed to examine the expression of related proteins and mRNAs. The migration ability of human nasal epithelial cells (HNEpCs) was evaluated with wound scratch assay. RNA sequencing was performed to investigate the downstream genes of FERMT1. The CRSwNP mouse model was established to study the effect of FERMT1 in vivo.

RESULTS

We found that FERMT1 was increased in nasal polyp tissues and correlated with the symptom scores of CRSwNP patients. Knockdown of FERMT1 inhibited the EMT process and cell migration induced by TGF-β1 through the PI3K/Akt pathway, and Akt inhibitor partially blocked the EMT induced by FERMT1 overexpression. In the CRSwNP mouse model, FERMT1 knockdown reduced nasal polyp formation and reversed the EMT process.

CONCLUSIONS

Our data indicate that knockdown of FERMT1 inhibits migration and EMT process of HNEpCs via PI3K/Akt signaling pathway, suggesting that FERMT1 may be a novel and potential therapeutic target for CRSwNP treatment.

M2 macrophage derived HMOX1 defines chronic rhinosinusitis with nasal polyps

BACKGROUND

Molecular signatures of chronic rhinosinusitis with nasal polyps (CRSwNP) related to macrophages remain unclear. This study aimed to develop a macrophage-associated diagnostic signature for CRSwNP.

METHODS

Transcriptome data from 54 patients with CRSwNP and 37 healthy controls across GSE136825, GSE36830, and GSE72713 were used to identify differentially expressed genes (DEGs) between two groups. Gene Set Enrichment Analysis and Weighted Gene Co-Expression Network Analysis pinpointed crucial pathways and gene clusters. A diagnostic model was created from these analyses and receiver operating characteristic curve (ROC), and further validated in our transcriptome data from 29 samples. Immune cell infiltration analysis was performed and linked those diagnostic genes to macrophages and verified by single-cell RNA sequencing data. Immunofluorescence co-staining of CD163 and HMOX1 was performed in nasal tissues. Mouse bone marrow-derived macrophage (BMDMs) cultures were used in functional experiments. Correlations between the expression of HMOX1 and eotaxin genes were investigated.

RESULTS

DEGs of CRSwNP versus control group were enriched in the INTERLEUKIN_4_AND_13_SIGNALING pathways. A four-gene diagnostic model (HMOX1, ALOX5, F13A1 and ITGB2) was developed and demonstrated high diagnostic precision with an area under ROC curve of 0.980 for training dataset and 0.895 for test dataset. M2 macrophage presence and HMOX1 expression significantly correlated with CRSwNP (p < 0.001). Single-cell RNA sequencing data underscored the altered cellular composition in CRSwNP, with HMOX1 notably expressed in M2 macrophages. Immunofluorescence staining highlighted the increased infiltration of CD163+ M2 macrophages in nasal mucosa samples of eosinophilic CRSwNP, which correlated with HMOX1 protein levels (p < 0.05). The HMOX1 inhibitor zinc protoporphyrin reduced the ratio of CD163 + HMOX1 + M2 macrophages in mouse BMDM cultures (p < 0.05). HMOX1 expression showed a strong positive correlation with the expression of eotaxin genes (CCL11, CCL24, and CCL26; p < 0.05 respectively).

CONCLUSION

M2 macrophage-derived HMOX1 can be used as an innovative diagnostic signature for CRSwNP, which might be a potential regulator of eosinophilic inflammation.

Upper airway comorbidities of asthma

Asthma, characterized as a chronic heterogeneous airway disease, often presents with common comorbid conditions. The concept of "one airway, one disease" was coined more than 20 years ago, emphasizing the connection between asthma and upper airway comorbidities (UACs) such as allergic or nonallergic rhinitis, chronic rhinosinusitis with or without nasal polyps, and aspirin/nonsteroidal anti-inflammatory drug-exacerbated respiratory disease. Since then, numerous studies have demonstrated that UACs are closely related and affect asthma phenotypes. Recognizing these UACs and managing them are crucial aspects of comprehensive asthma care. Addressing these conditions as part of asthma treatment can lead to better control of symptoms, improved lung function, and better quality of life. Moreover, it is important to explore the field of respiratory biologics, which represents the latest advancements in medical treatment options for patients with asthma and UACs.

Assessment of Gustatory Function in Patients of Chronic Rhinosinusitis: A Case Control Study

Gustation is affected in patients of Chronic rhinosinusitis (CRS) depending on severity of diseases. This study aimed to find the prevalence of gustatory dysfunction in patients with CRS. This case-control study included 61 patients with CRS and 61 healthy controls. Patients were subjected to non-contrast CT scan of the paranasal sinuses. Disease severity was assessed using the Lund Mackay Scoring. Gustatory assessment was done as per scoring of Mueller et al. Taste score of 9 or more was considered normal. The outcome measures were gustatory dysfunction and association with presence of polyps and CRS severity. P-value < 0.05 was considered statistically significant. Compared to controls, cases had significantly lower total taste scores (12 vs. 15, P < 0.001). Gustatory dysfunction was seen among 13 (21.3%) patients. It was significantly more among those with polyps than without [8(53.3%) vs. 5(10.9%), P < 0.05]. There was a significant negative correlation between the gustatory dysfunction scores and the severity of CRS (r=-0.664, P < 0.001). In conclusion, we report a prevalence of gustatory dysfunction in 21.3% cases of CRS which was negatively affected by the presence of nasal polyps and CRS severity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-024-04978-0.

Mucosal Inflammatory Memory in Chronic Rhinosinusitis

Recent advancements in medical management, endoscopic sinus surgery, and biologics have significantly improved outcomes for patients with chronic rhinosinusitis (CRS). However, long-term recurrence is frequently observed following endoscopic sinus surgery, with symptoms worsening after biologics are discontinued. Consequently, refractory or recurrent CRS remains a significant challenge, causing a substantial healthcare burden. In this review, we provide current insights into mucosal inflammatory memory, a potential mechanism leading to CRS recurrence. Given that both immune and non-immune cells in the sinonasal mucosa play critical roles in the pathophysiology of CRS, a deeper understanding of the mechanisms underlying mucosal inflammatory memory in various cellular components of sinonasal tissue could aid in the management of refractory CRS. We describe and discuss the latest knowledge regarding the novel concept of inflammatory memory, including both adaptive immune memory and trained immunity. Additionally, we summarize the pathogenic memory features of the sinonasal mucosa cellular components in the context of CRS.

Update on the Biological and Clinical Relevance of Mast Cells in Chronic Rhinosinusitis with Nasal Polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common inflammatory disorder whose complex immunopathogenesis has yet to be fully elucidated. Endotype-2 CRSwNP is the most common form of disease where eosinophils are the main drivers of inflammation. Traditional treatments for CRSwNP have centered around intranasal or systemic corticosteroids and endoscopic sinus surgery (ESS). However, recent advancements in targeted therapies have introduced novel biological agents that specifically target key inflammatory mediators such as IL-4, IL-5, and IL-13. These biologics offer promising options for patients with CRSwNP, particularly those who do not respond adequately to conventional treatments. Nonetheless, some patients do not satisfactorily respond to these drugs because of an insufficient blockade of the inflammatory process. The mast cell (MC) is another important (and somehow neglected) actor in the pathogenesis of CRSwNP, and the latest clinical and translational evidence in this field has been reviewed in the present paper.

Revisiting T Cells in Chronic Rhinosinusitis

A variety of immune cells in the nasal tissue are involved in the immunopathogenesis of chronic rhinosinusitis (CRS), a chronic inflammatory disease affecting the nasal cavity and paranasal sinuses. T cells play a pivotal role in orchestrating immune dysregulation in CRS by producing key cytokines. Recent studies have expanded the understanding of T cell biology across the inflammatory endotypes of CRS. This review summarizes current knowledge on the multifaceted roles of T cells in the pathophysiology of CRS. Particularly, we highlight the alterations in phenotypes and functions of various T cell subsets in CRS. Additionally, as functional studies of effector and regulatory T cell populations have revealed potential translational targets, we suggest perspectives for future research into T cell-oriented therapeutic strategies for CRS.

NRP1 antagonism as a novel therapeutic target in nasal polyps of patients with chronic rhinosinusitis

BACKGROUND

Neuropilin-1 (NRP1) is expressed on the surface epithelium of respiratory tract and immune cells, demonstrating its possible function in regulating the immune response in airway disease. However, its role in patient with chronic rhinosinusitis (CRS) remains unknown. This study aimed to elucidate the role of NRP1 in CRS with nasal polyps (CRSwNP).

METHODS

Sinonasal biopsy specimens were immunohistochemically stained to investigate NRP1 expression. Double immunofluorescence, immunoblotting, and real-time polymerase chain reaction were performed to evaluate NRP1 in primary human nasal epithelial cells (hNECs). An NRP1 inhibitor was administered to a murine nasal polyp (NP) model.

RESULTS

NRP1 was highly expressed in the epithelium in patients with CRSwNP compared to nasal tissue from controls and CRS without NP patients. NRP1 and vascular endothelial growth factor were upregulated in hNECs under hypoxia. Treatment with NRP1 inhibitor (EG00229) reduced the secretion of interleukin (IL)-1β, IL-6, IL-8, and IL-33 cytokines, as well as inducible nitric oxide synthase, cyclooxygenase-2, and prostaglandin E2 in hNECs. We found that NRP1 was highly expressed in the airway epithelium in the murine NP model. The group treated with the NRP1 inhibitor had significantly fewer nasal polypoid lesions and reduced accumulations of immune cells.

CONCLUSIONS

These findings reveal that NRP1 is upregulated in CRS and NP epithelium, and the inhibition of NRP1 may lead to a reduction in NP growth and immune cell infiltration. Our results suggest that NRP1 inhibition could be a novel possibility for treating nasal polyposis.

Inflammatory Profile of Chronic Rhinosinusitis With Nasal Polyp Patients in Brazil: Multicenter Study

OBJECTIVES

To determine the inflammatory profile of CRSwNP in Brazil and characterize the subgroups of CRSwNP patients in this population through cluster analysis.

STUDY DESIGN

Multicenter cross-sectional study involving 15 centers representing different regions of Brazil.

SUBJECTS AND METHODS

Clinical data of 166 patients and 80 controls, aged 18 to 70 years old, number of surgeries for CRS, history of asthma and aspirin sensitivity, and Lund-Mackay scores on CT scans. During nasal endoscopy, we obtained the Lund-Kennedy scores and collected 2 samples of nasal polyps: one for eosinophil and neutrophil tissue counts and one to quantify different cytokines.

RESULTS

79.6% of our patients had 10 or more eosinophils/HPF. CRSwNP groups exhibited significantly lower concentrations of TNF-alpha and significantly higher concentrations of IFN-gamma, CCL11/Eotaxin, CCL24/Eotaxin-2/MPIF-2, and CCL26/Eotaxin-3 versus the control group (Kruskal-Wallis test). Comparison between CRSwNP groups (≥10 vs <10 eosinophils/HPF) showed no difference in cytokine concentration (Mann-Whitney test). Hierarchical clustering and PCA according to cytokine concentrations revealed 2 main Clusters, with a significantly higher concentration of all cytokines in Cluster 1 (n = 35) than in Cluster 2 (n = 121), except IL-6 and IL-33 (Mann-Whitney test). According to ROC curve analysis the best cut-off to differentiate the 2 clusters was 43 eosinophils/HPF. The group with ≥43 presented a higher prevalence of men and a higher Lund-Mackay score (Mann-Whitney test).

CONCLUSIONS

CRSwNP patients in Brazil present mixed inflammation, with 2 distinct groups (high and low inflammatory pattern) that can be distinguished by tissue eosinophilia of ≥43 eosinophils/HPF cut-off in nasal polyps.

Clinical Observation of Hydrogen-Rich Saline for Nasal Irrigation After Surgery for Chronic sinusitis:A Randomized, Double-Blind, Controlled Trial

Purpose

The treatment of chronic rhinosinusitis (CRS) is often a difficult and long-term behavior, so it is necessary to seek a local treatment method that can be used for a long time, and is safe and effective. Nasal saline irrigation after functional endoscopic sinus surgery (FESS) is currently recognized as a local treatment method, but it has no anti-inflammatory, anti-damage, and healing-promoting functions. To investigate the efficacy and safety of hydrogen-rich saline (HRS) for nasal irrigation after CRS surgery.

Patients and Methods

A total of 61 patients after CRS completed the study. Subjects were randomly assigned to rinse the nasal cavity with HRS or normal saline (NS) after CRS. Participants were followed up once a week for 12 times, and were evaluated with visual analogue score (VAS), 22-item Sinonasal Outcomes Test (SNOT-22), and Lund-Kennedy endoscopy scores (LKES). The primary outcome was the VAS score of patients.

Results

After 12 weeks of follow-up, the VAS scores of both groups decreased, and the HRS group (0.52±0.85) was lower than the NS group (1.47±1.55), P=0.005. The total number of cases with complete control (clinical cure) in the short-term efficacy evaluation was more in the HRS group (20/31) than in the NS group (11/30), P=0.03<0.05. No obvious adverse reactions occurred in the two groups during the follow-up.

Conclusion

This study found that HRS was more effective than NS alone in nasal irrigation after CRS surgery, and could shorten the time of nasal mucosal healing and epithelialization, with a higher rate of recent complete control.

Tezepelumab for severe asthma: elevating current practice to recognize epithelial driven profiles

BACKGROUND

An increasing amount of evidence supports the relevance of epithelium across the wide spectrum of asthma pathobiology. On a clinical ground tezepelumab, selectively binding TSLP, a major epithelial cytokine, has demonstrated to be effective in asthma patients regardless their specific phenotype. In order to avoid the risk of considering tezepelumab as a not-specific option, the present perspective aims to sketch the tezepelumab best eligible patient profile and to propose some hallmarks of epithelial-driven disease by reviewing the published evidence on the drug mechanism of action and efficacy data.

MAIN BODY

Although it cannot rely on standardised or exclusive "markers", the relationship between environment and poor asthma control might suggest a major relevance of the epithelial barrier dysfunction. In that light, allergy and asthma exacerbations concomitant with specific exposures (pathogens, pollutants, chemicals), as well as increased susceptibility to infections can be considered as the hallmark of an impaired epithelial immune response. Tezepelumab is effective in allergic patients, being able to reduce asthma exacerbations precipitated by the exposure to seasonal or perennial aeroallergens, including fungi. In addition, tezepelumab reduced the incidence of co-occurring respiratory illness and asthma exacerbations. In terms of inflammation, epithelial immune response has been related to an impaired mucus hypersecretion and plugging. A placebo-controlled trial demonstrated a significant reduction of mucus plugging in treated patient. Airways hyperreactivity (AHR), airways obstruction and remodelling have been described as an expression of epithelial orchestrated immunological activation. Of note, a significantly higher incidence of mannitol negative test in patients treated with tezepelumab when compared to placebo group has been observed. In addition, A 130 mL improvement in pre-BD FEV1 has been described in patients assuming Tezepelumab. The above-mentioned data suggest that bronchial reversibility and AHR can be considered "functional biomarkers" supporting patients' phenotyping and the identification of tezepelumab best responders.

CONCLUSION

Integrating "functional biomarkers" to the inflammatory ones and a better characterization of asthma exacerbations might pave the way to a different and more transversal phenotyping, which overcomes the "restrictive" labels including T2 high, allergic/atopic or T2 low asthma. Precisely defining the disease characteristics and potential targets for a better control even in tezepelumab eligible subjects is essential to avoid the block buster temptation and optimize the personalized medicine approach according to each patient's individuality.

Mucosal LTE4, PGD2 and 15(S)-HETE as potential prognostic markers for polyp recurrence in chronic rhinosinusitis

BACKGROUND

Altered biosynthesis of eicosanoids is linked to type 2 inflammation in chronic rhinosinusitis with nasal polyps (CRSwNP), but their role in recalcitrant NPs is unclear.

OBJECTIVES

We sought to identify endotypes that are linked to recalcitrant CRSwNP, based on eicosanoids, their biosynthetic enzymes, and receptors as well as cytokines and the presence of eosinophils and mast cells in recurrent NPs.

METHODS

Mucosal tissue collected at the time of sinus surgery from 54 patients with CRSwNP and 12 non-CRS controls were analysed for leukotriene (LT) E4, prostaglandin (PG) D2, 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE) and 17 cytokines with ELISAs and Bio-Plex immunoassays. Patient subgroups were identified by cluster analysis and the probability of NP recurrence were tested with logistic regression analyses. Gene expressions were analysed with qPCR. Tryptase and eosinophil-derived neurotoxin (EDN) were measured with ELISAs as indications of the presence of mast cells and eosinophils, respectively.

RESULTS

Clustering of patients showed that an inflammatory signature characterised by elevated LTE4, PGD2, 15(S)-HETE and IL-13 was associated with NP recurrence. Previous NP surgery as well as aspirin-exacerbated respiratory disease were significantly more common among these patients. Expression of cyclooxygenase 1 was the only gene associated with NP recurrence. Levels of EDN, but not tryptase, were significantly higher in patients with recurrent NPs.

CONCLUSION

Distinguishing endotypes that include LTE4, PGD2, 15HETE and conventional biomarkers of type 2 inflammation could help predict recurrent nasal polyposis and thus identify cases of recalcitrant CRSwNP.

Dupilumab-related late adverse events in patients with chronic rhinosinusitis with nasal polyps

BACKGROUND

Anti-IL-4 receptor α antibody (dupilumab) has demonstrated favorable sinonasal outcomes for chronic rhinosinusitis with nasal polyps (CRSwNP), which is mainly caused by type 2 inflammation. Although increased blood eosinophil levels and injection site symptoms are frequently observed as acute adverse events (AEs) of dupilumab, limited knowledge is available regarding the late AEs of dupilumab for CRSwNP.

OBJECTIVES

We investigated the late AEs following the initiation of dupilumab treatment for CRSwNP.

MATERIAL AND METHODS

Fifty-one patients with CRSwNP treated with dupilumab for > 3 months were enrolled, and their clinical data were collected from their medical records.

RESULTS

Six (11.8%) patients experienced late AEs. One case of eczema with pruritus, one case of psoriasis-like dermatitis, two cases of severe rash, one case of malignant lymphoma, and one case of alopecia areata were observed. Skin disorders were the most common late AEs in this study. It is a Th1-inflammatory disease, and its mechanism is thought to be due to the immune imbalance caused by dupilumab. We could not confirm whether malignant lymphoma in our case was caused by dupilumab use.

CONCLUSIONS AND SIGNIFICANCE

Skin disorders are often late AEs associated with dupilumab; therefore, careful monitoring after dupilumab initiation should be considered.

Integrated machine learning and bioinformatic analysis of mitochondrial-related signature in chronic rhinosinusitis with nasal polyps

Background

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a prevalent inflammatory disorder affecting the upper respiratory tract. Recent studies have indicated an association between CRSwNP and mitochondrial metabolic disorder characterized by impaired metabolic pathways; however, the precise mechanisms remain unclear. This study aims to investigate the mitochondrial-related signature in individuals diagnosed with CRSwNP.

Methods

Through the integration of differentially expressed genes (DEGs) with the mitochondrial gene set, differentially expressed mitochondrial-related genes (DEMRGs) were identified. Subsequently, the hub DEMRGs were selected using 4 integrated machine learning algorithms. Immune and mitochondrial characteristics were estimated based on CIBERSORT and ssGSEA algorithms. Bioinformatic findings were confirmed through RT-qPCR, immunohistochemistry, and ELISA for nasal tissues, as well as Western blotting analysis for human nasal epithelial cells (hNECs). The relationship between hub DEMRGs and disease severity was assessed using Spearman correlation analysis.

Results

A total of 24 DEMRGs were screened, most of which exhibited lower expression levels in CRSwNP samples. Five hub DEMRGs (ALDH1L1, BCKDHB, CBR3, HMGCS2, and OXR1) were consistently downregulated in both the discovery and validation cohorts. The hub genes showed a high diagnostic performance and were positively correlated with the infiltration of M2 macrophages and resting mast cells. Experimental results confirmed that the 5 genes were downregulated at both the mRNA and protein levels within nasal polyp tissues. Finally, a significant and inverse relationship was identified between the expression levels of these genes and both the Lund-Mackay and Lund-Kennedy scores.

Conclusion

Our findings systematically unraveled 5 hub markers correlated with mitochondrial metabolism and immune cell infiltration in CRSwNP, suggesting their potential to be based to design diagnostic and therapeutic strategies for the disease.