Pathogenesis Of Chronic Rhinosinusitis Research Articles

Single-cell transcriptomic sequencing coupled with Mendelian randomization analysis elucidates the pivotal role of CTSC in chronic rhinosinusitis

Objective: To investigate the molecular mechanisms of chronic rhinosinusitis (CRS), to identify key cell subgroups and genes, to construct effective diagnostic models, and to screen for potential therapeutic drugs. Methods: Key cell subgroups in CRS were identified through single-cell transcriptomic sequencing data. Essential genes associated with CRS were selected and diagnostic models were constructed by hdWGCNA (high dimensional weighted gene co-expression network analysis) and various machine learning algorithms. Causal inference analysis was performed using Mendelian randomization and colocalization analysis. Potential therapeutic drugs were identified using molecular docking technology, and the results of bioinformatics analysis were validated by immunofluorescence staining. Graphpad Prism, R, Python, and Adobe Illustrator software were used for data and image processing. Results: An increased proportion of basal and suprabasal cells was observed in CRS, especially in eosinophilic CRS with nasal polyps (ECRSwNP), with P=0.001. hdWGCNA revealed that the "yellow module" was closely related to basal and suprabasal cells in CRS. Univariate logistic regression and LASSO algorithm selected 13 key genes (CTSC, LAMB3, CYP2S1, TRPV4, ARHGAP21, PTHLH, CDH26, MRPS6, TENM4, FAM110C, NCKAP5, SAMD3, and PTCHD4). Based on these 13 genes, an effective CRS diagnostic model was developed using various machine learning algorithms (AUC=0.958). Mendelian randomization analysis indicated a causal relationship between CTSC and CRS (inverse variance weighted: OR=1.06, P=0.006), and colocalization analysis confirmed shared genetic variants between CTSC and CRS (PPH4/PPH3>2). Molecular docking results showed that acetaminophen binded well with CTSC (binding energy:-5.638 kcal/mol). Immunofluorescence staining experiments indicated an increase in CTSC+cells in CRS. Conclusion: This study integrates various bioinformatics methods to identify key cell types and genes in CRS, constructs an effective diagnostic model, underscores the critical role of the CTSC gene in CRS pathogenesis, and provides new targets for the treatment of CRS.

The oxidant-antioxidant imbalance was involved in the pathogenesis of chronic rhinosinusitis with nasal polyps.

Although oxidative stress is involved in the pathophysiological process of chronic rhinosinusitis with nasal polyps (CRSwNP), the specific underlying mechanism is still unclear. Whether antioxidant therapy can treat CRSwNP needs further investigation. Immunohistochemistry, immunofluorescence, western blotting and quantitative polymerase chain reaction (qPCR) analyses were performed to detect the distribution and expression of oxidants and antioxidants in nasal polyp tissues. qPCR revealed correlations between oxidase, antioxidant enzymes and inflammatory cytokine levels in CRSwNP patients. Human nasal epithelial cells (HNEpCs) and primary macrophages were cultured to track the cellular origin of oxidative stress in nasal polyps(NPs) and to determine whether crocin can reduce cellular inflammation by increasing the cellular antioxidant capacity. The expression of NOS2, NOX1, HO-1 and SOD2 was increased in nasal epithelial cells and macrophages derived from nasal polyp tissue. Oxidase levels were positively correlated with those of inflammatory cytokines (IL-5 and IL-6). Conversely, the levels of antioxidant enzymes were negatively correlated with those of IL-13 and IFN-γ. Crocin inhibited M1 and M2 macrophage polarization as well as the expression of NOS2 and NOX1 and improved the antioxidant capacity of M2 macrophages. Moreover, crocin enhanced the ability of antioxidants to reduce inflammation via the KEAP1/NRF2/HO-1 pathway in HNEpCs treated with SEB or LPS. Additionally, we observed the antioxidant and anti-inflammatory effects of crocin in nasal explants. Oxidative stress plays an important role in the development of CRSwNP by promoting various types of inflammation. The oxidative stress of nasal polyps comes from epithelial cells and macrophages. Antioxidant therapy may be a promising strategy for treating CRSwNP.

Small extracellular vesicles facilitate epithelial-mesenchymal transition in chronic rhinosinusitis with nasal polyps via the miR-375-3p/QKI axis.

Epithelial-mesenchymal transition (EMT) plays a crucial role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). However, the involvement of small extracellular vesicles (sEVs) in EMT and their contributions to CRSwNP has not been extensively investigated. SEVs were isolated from nasal mucosa through ultracentrifugation. MicroRNA sequencing and reverse-transcription quantitative polymerase chain reaction were employed to analyze the differential expression of microRNAs carried by sEVs. Human nasal epithelial cells (hNECs) were used to assess the EMT-inducing effect of sEVs/microRNAs. EMT-associated markers were detected by western blotting and immunofluorescence. Dual-luciferase reporter assay was performed to determine the target gene of miR-375-3p. MicroRNA mimic, lentiviral, and plasmid transduction were used for functional experiments. In line with the greater EMT status in eosinophilic CRSwNP (ENP), sEVs derived from ENP (ENP-sEVs) could induce EMT in hNECs. MiR-375-3p was elevated in ENP-sEVs compared to that in control and nonENP. MiR-375- 3p carried by ENP-sEVs facilitated EMT by directly targeting KH domain containing RNA binding (QKI) at seed sequences of 913-919, 1025-1033, and 2438-2444 in 3'-untranslated region. Inhibition of QKI by miR-375-3p overexpression promoted EMT, which could be reversed by restoration of QKI. Furthermore, the abundance of miR-375-3p in sEVs was closely correlated with the clinical symptom score and disease severity. MiR-375-3p-enriched sEVs facilitated EMT by suppressing QKI in hNECs. The association of miR-375-3p with disease severity underscores its potential as both a diagnostic marker and a therapeutic target for the innovative management of CRSwNP.

Neurocognitive disorders and chronic rhinosinusitis. A modern view of the problem (literary review)

The purpose of the study: to review the results of scientific research on combined etiopathogenetic, clinical, and functional manifestations of chronic rhinosinusitis and a number of neurological diseases classified as neurocognitive disorders (NCDs). The interdisciplinary approach in the analysis was based on the modern understanding of neurocognitive disorders and induced neuroinflammatory reactions, the commonality between the infectious agents in the pathogenesis of chronic rhinosinusitis and diseases characterized by NCDs, and the validity of the involvement of central brain structures in the process of chronic inflammation of the nasal cavity and paranasal sinuses. The analogy of the formation of such manifestations as nasal obstruction, changes in the olfactory tract and visual function, and disorders of the microbiota of the upper respiratory tract, and their impact on brain structures with impaired neurocognitive functions was drawn. The systematization of scientific research data characterizing various chronic forms of rhinosinusitis and NCDs was a confirmation of the regulatory role of the autonomic nervous system and the hypothalamic-limbic-reticular complex in understanding the common pathophysiological mechanisms occurring in these nosologies.

Particulate matter exposure is associated with increased inflammatory cytokines and eosinophils in chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is thought to result from complex interactions between the host immune system, microbiota, and environmental exposures. Currently, there is limited data regarding the impact of ambient particulate matter ≤2.5 μm in diameter (PM2.5) in the pathogenesis of CRS, despite evidence linking PM2.5 to other respiratory diseases. We hypothesized that PM2.5 may result in differential cytokine patterns that could inform our mechanistic understanding of the effect of environmental factors on CRS. We conducted an analysis of data prospectively collected from 308 CRS patients undergoing endoscopic sinus surgery. Cytokines were quantified in intraoperative mucus specimens using a multiplex flow cytometric bead assay. Clinical and demographic data including zip codes were extracted and used to obtain tract-level income and rurality measures. A spatiotemporal machine learning model was used to estimate daily PM2.5 levels for the year prior to each patient's surgery date. Spearman correlations and regression analysis were performed to characterize the relationship between mucus cytokines and PM2.5. RESULTS: Several inflammatory cytokines including IL-2, IL-5/IL-13, IL-12, and 21 were significantly correlated with estimated average 6, 9, and 12-month preoperative PM2.5 levels. These relationships were maintained for most cytokines after adjusting for age, income, body mass index, rurality, polyps, asthma, and allergic rhinitis (AR) (p < .05). There were also higher odds of asthma (OR = 1.5, p = .01) and AR (OR = 1.48, p = .03) with increasing 12-month PM2.5 exposure. Higher tissue eosinophil counts were associated with increasing PM2.5 levels across multiple timeframes (p < .05). Chronic PM2.5 exposure may be an independent risk factor for development of a mixed, type-2 dominant CRS inflammatory response.

Aspergillus Enhances Eosinophil and Neutrophil Extracellular DNA Trap Formation in Chronic Rhinosinusitis.

Chronic rhinosinusitis (CRS) is characterized by inflammatory cell infiltration in the sinonasal mucosa. Eosinophil and neutrophil extracellular traps (EETs and NETs, respectively) are prominently found in CRS. This study aimed to investigate the effect of airborne fungi, Alternaria alternata and Aspergillus fumigatus, on EET and NET formation. Nasal epithelial cells, eosinophils, and neutrophils were isolated from eosinophilic CRS (ECRS), non-ECRS (NECRS), and healthy control. We determined eosinophil and neutrophil transepithelial migration after fungal treatment. We then determined the release of EETs and NETs by fungi using Sytox Green staining and determined the role of reactive oxygen species (ROS) using ROS inhibitors. We identified more abundant EETs and NETs in ECRS than in NECRS. A. alternata and A. fumigatus enhanced eosinophil and neutrophil transepithelial migration. A. fumigatus strongly induced EET and NET formation in CRS and, simultaneously, suppressed fungal metabolic activity. EET formation in CRS is associated with nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase and NET formation with NADPH-oxidase and mitochondrial ROS. A. fumigatus, but not A. alternata, induced EET and NET formation, and peripheral blood eosinophils and neutrophils exhibited different immune responses against A. fumigatus following the inflammatory status of the host. Aspergillus-fumigatus-induced EET and NET formation plays a crucial role in CRS pathogenesis.

Oncostatin M's Involvement in the Pathogenesis of Chronic Rhinosinusitis: Focus on Type 1 and 2 Inflammation.

The cytokine oncostatin M (OSM) elicits pathogenic effects involving disruption of the epithelial barrier function as a part of immunological response networks. It is unclear how these integrated cytokine signals influence inflammation and other physiological processes in the pathology of chronic rhinosinusitis (CRS). We investigated the expression and distribution of OSM and OSM receptor (OSMR) in CRS patients' sinonasal specimens, and we compared the results with a panel of inflammatory cytokine levels and clinical features. We classified CRS patients as eosinophilic (ECRS, n = 36) or non-eosinophilic (non-ECRS, n = 35) based on the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis phenotypic criteria and compared their cases with those of 20 control subjects. We also examined OSM's stimulatory effects on cytokine receptor expression levels using the human bronchial epithelium cell line BEAS-2B. RT-PCR showed that the OSM mRNA levels were significantly increased in the CRS patients' ethmoid sinus mucosa. The OSM mRNA levels were positively correlated with those of TNF-α, IL-1β, IL-13, and OSMR-β. In BEAS-2B cells, OSM treatment induced significant increases in the OSMRβ, IL-1R1, and IL-13Ra mRNA levels. OSM is involved in the pathogenesis of CRS in both type 1 and type 2 inflammation, suggesting the OSM signaling pathway as a potential therapeutic target for modulating epithelial stromal interactions.

Neutrophil extracellular traps promote ΔNp63+ basal cell hyperplasia in chronic rhinosinusitis

Neutrophil extracellular traps (NETs) are observed in chronic rhinosinusitis (CRS), although their role remains unclear. This study aimed to investigate the influence of NETs on the CRS epithelium. Forty-five sinonasal biopsy specimens were immunofluorescence-stained to identify NETs and p63+ basal stem cells. Investigators treated human nasal epithelial cells with NETs and studied them with immunofluorescence staining, Western blotting, and quantitative real-time PCR. NET inhibitors were administered to a murine neutrophilic nasal polyp model. NETs existed in tissues in patients with CRS with nasal polyps, especially in noneosinophilic nasal polyp tissues. p63+ basal cell expression had a positive correlation with the release of NETs. NETs induced the expansion of Ki-67+p63+ cells. We found that ΔNp63, an isoform of p63, was mainly expressed in the nasal epithelium and controlled by NETs. Treatment with deoxyribonuclease (DNase) I or Sivelestat (NET inhibitors) prevented the overexpression of ΔNp63+ epithelial stem cells and reduced polyp formation. These results reveal that NETs are implicated in CRS pathogenesis via basal cell hyperplasia. This study suggests a novel possibility of treating CRS by targeting NETs.

Pathophysiological features of chronic IgE-mediated rhinosinusitis of bacterial etiology

Chronic rhinosinusitis (CRS) is a disease caused by inflammation of the paranasal sinuses and its mucous membrane lasting for more than 4 weeks continuously. The aim of our study was to examine the main pathophysiological features of chronic IgE-mediated rhinosinusitis of bacterial etiology according to publications in the Russian Federation and in the world. A search was made through English- and Russian-language literature sources using the following databases: PubMed, MedLine, Web of Science, Russian Science Citation Index, Springer, Scopus, Scientific Research, Google Scholar, Crossref, eLibrary. The epidemiological features of CRS in the Russian Federation, bacterial pathogens and pathophysiological characteristics of CRS were analyzed. A 2-fold increase in the prevalence of CRS was registered over the past 20 years. Prevalence of the disease increases at longer age ranges. Chronic rhinosinusitis ranks first among all chronic diseases in the field of otorhinolaryngology. Allergic rhinitis, asthma, bronchiectasia, immunodeficiencies, cystic fibrosis, primary ciliary dyskinesia and autoimmune diseases are associated with CRS. The most common bacterial pathogens are S. aureus, Staphylococcus epidermidis and Propionibacterium acnes, Prevotella, Streptococcus and Veillonella, and some Gram-negative bacteria, e.g., Pseudomonas aeruginosa (P. aeruginosa), Proteus mirabilis and Klebsiella pneumoniae. Staphylococcus aureus (S. aureus) is involved in pathogenesis of nasal polyps. The colonizing bacteria may contribute to pathogenesis of CRS through the formation of biofilms. Alterations in the sino-nasal microbiome may also contribute to the development of CRS. An association of the CRS and CFTR gene mutations plays a significant role in the pathogenesis of chronic rhinosinusitis. An “immune barrier hypothesis” has been proposed as potential mechanism of CRS. Reduced expression of SPINK5, impaired STAT3 signaling, and T2R38 bitter taste receptor polymorphism have been identified in the pathogenesis of CRS. The T2R38 gene stimulates epithelial cells to produce nitrous oxide with a bactericidal effect, promotes mucociliary elimination of pathogens and prevention of upper respiratory tract infections, the polymorphism of this gene predisposes patients to gram-negative infectious diseases, and therefore is a risk factor for the development of CRS. In addition, antibody deficiency is the most common primary immunodeficiency associated with CRS.Hence, the pathogenesis of chronic IgE-mediated rhinosinusitis of bacterial etiology is associated with defects in innate immunity and mucociliary clearance, influence of the sinonasal microbiome, allergies, and genetic factors. A comprehensive assessment of these factors is necessary for the development of new preventive and therapeutic options for the correction of CRS.

The interplay of inflammation and remodeling in the pathogenesis of chronic rhinosinusitis: current understanding and future directions.

Chronic rhinosinusitis (CRS), a common clinical condition characterized by persistent mucosal inflammation and tissue remodeling, has a complex pathogenesis that is intricately linked to innate and adaptive immunity. A number of studies have demonstrated that a variety of immune cells and cytokines that play a vital role in mediating inflammation in CRS are also involved in remodeling of the nasal mucosa and the cells as well as different cytokines involved in remodeling in CRS are also able to exert some influence on inflammation, even though the exact relationship between inflammation and remodeling in CRS has not yet been fully elucidated. In this review, the potential role of immune cells and cytokines in regulating inflammation and remodeling of CRS mucosa has been described, starting with the immune cells and cytokines that act together in inflammation and remodeling. The goal is to aid researchers in understanding intimate connection between inflammation and remodeling of CRS and to offer novel ideas for future research.

Comprehensive analysis of mitophagy-related genes in diagnosis and heterogeneous endothelial cells in chronic rhinosinusitis: based on bulk and single-cell RNA sequencing data.

Background: Chronic rhinosinusitis (CRS) is a complex inflammatory disorder affecting the nasal and paranasal sinuses. Mitophagy, the process of selective mitochondrial degradation via autophagy, is crucial for maintaining cellular balance. However, the role of mitophagy in CRS is not well-studied. This research aims to examine the role of mitophagy-related genes (MRGs) in CRS, with a particular focus on the heterogeneity of endothelial cells (ECs). Methods: We employed both bulk and single-cell RNA sequencing data to investigate the role of MRGs in CRS. We compiled a combined database of 92 CRS samples and 35 healthy control samples from the Gene Expression Omnibus (GEO) database and we explored the differential expression of MRGs between them. A logistic regression model was built based on seven key genes identified through Random Forests and Support Vector Machines - Recursive Feature Elimination (SVM-RFE). Consensus cluster analysis was used to categorize CRS patients based on MRG expression patterns and weighted gene co-expression network analysis (WGCNA) was performed to find modules of highly correlated genes of the different clusters. Single-cell RNA sequencing data was utilized to analyze MRGs and EC heterogeneity in CRS. Results: Seven hub genes-SQSTM1, SRC, UBA52, MFN2, UBC, RPS27A, and ATG12-showed differential expression between two groups. A diagnostic model based on hub genes showed excellent prognostic accuracy. A strong positive correlation was found between the seven hub MRGs and resting dendritic cells, while a significant negative correlation was observed with mast cells and CD8+ T cells. CRS could be divided into two subclusters based on MRG expression patterns. WGCNA analysis identified modules of highly correlated genes of these two different subclusters. At the single-cell level, two types of venous ECs with different MRG scores were identified, suggesting their varying roles in CRS pathogenesis, especially in the non-eosinophilic CRS subtype. Conclusion: Our comprehensive study of CRS reveals the significant role of MRGs and underscores the heterogeneity of ECs. We highlighted the importance of Migration Inhibitory Factor (MIF) and TGFb pathways in mediating the effects of mitophagy, particularly the MIF. Overall, our findings enhance the understanding of mitophagy in CRS, providing a foundation for future research and potential therapeutic developments.

S. aureus biofilm metabolic activity correlates positively with patients’ eosinophil frequencies and disease severity in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a persistent inflammation of the sinus mucosa. Recalcitrant CRS patients are unresponsive to medical and surgical interventions and often present with nasal polyps, tissue eosinophilia, and Staphylococcus aureus dominant mucosal biofilms. However, S. aureus sinonasal mucosal colonisation occurs in the absence of inflammation, questioning the role of S. aureus in CRS pathogenesis. Here, we aimed to investigate the relationship between S. aureus biofilm metabolic activity and virulence genes, innate immune cells, and disease severity in CRS. Biospecimens, including sinonasal tissue and nasal swabs, and clinical datasets, including disease severity scores, were obtained from CRS patients and non-CRS controls. S. aureus isolates were grown into biofilms in vitro, characterised, and sequenced. The patients’ innate immune response was evaluated using flow cytometry. S. aureus was isolated in 6/19 (31.58%) controls and 23/53 (43.40%) CRS patients of 72 recruited patients. We found increased S. aureus biofilm metabolic activity in relation to increased eosinophil cell frequencies and disease severity in recalcitrant CRS cases. Mast cell frequencies were higher in tissue samples of patients carrying S. aureus harbouring lukF.PV, sea, and fnbB genes. Patients with S. aureus harbouring lukF.PV and sdrE genes had more severe disease. This offers insights into the pathophysiology of CRS and could lead to the development of more targeted therapies.

Fungal and Bacterial Microbiome in Sinus Mucosa of Patients with and without Chronic Rhinosinusitis.

Dysbiosis of the sinonasal microbiome has been implicated in the pathogenesis of chronic rhinosinusitis (CRS). However, the mycobiome remains largely understudied, and microbial alterations associated with specific CRS subtypes have yet to be delineated. The objective of this study is to investigate the fungal and bacterial microbiome of sinus mucosa in CRS patients with and without nasal polyposis (CRSwNP and CRSsNP) versus healthy controls. Sinus mucosa was obtained from 92 patients (31 CRSsNP, 31 CRSwNP, and 30 controls) undergoing endoscopic sinus/skull base surgery. Data regarding demographics, Lund-MacKay scores, and histopathology were collected. Fungal and bacterial microbiome analysis was performed utilizing internal transcribed spacer amplicon and 16S rRNA sequencing. Beta diversity of the sinonasal mycobiome differed significantly between CRS and controls (p = 0.001) and between CRSwNP and controls (p = 0.049), but not between CRSwNP and CRSsNP (p = 0.32) nor between CRSsNP and controls (p = 0.06). With respect to the bacterial microbiome, significantly lower alpha diversity was observed between CRS and controls (p < 0.001), CRSwNP versus controls (p < 0.001), and CRSsNP versus controls (p < 0.001). Beta diversity was also significantly different at the genus level between CRSwNP and CRSsNP (p = 0.019), CRSwNP and controls (p = 0.002)), and CRSsNP and controls (p < 0.001). However, alpha and beta diversity did not differ significantly between CRS patients with/without eosinophils or correlate with Lund-MacKay scores. Differences in mycobiota diversity in CRS patients in comparison with controls suggest that alterations in the mycobiome may contribute to disease pathogenesis. Our findings also confirmed that diminished diversity among bacterial communities is associated with CRS and that significant differences are present in microbial composition between CRSwNP and CRSsNP. 3 Laryngoscope, 134:1054-1062, 2024.

Hypoxia induces the production of epithelial-derived cytokines in eosinophilic chronic rhinosinusitis with nasal polyps.

Hypoxia plays a significant role in the pathogenesis of chronic rhinosinusitis (CRS). However, the role and mechanism of hypoxia in the type 2 immune response in eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) remain unclear. The expression of hypoxia-inducible factor-1α (HIF-1α) and epithelial-derived cytokines (EDCs), including interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin (TSLP), was detected in nasal polyps via immunohistochemical analysis. The relationship between HIF-1α and EDCs was also elucidated using Pearson's correlation. Moreover, primary human nasal epithelial cells (HNECs) and a mouse model of ECRSwNP were employed to elucidate the role and mechanism of hypoxia in type 2 immune responses. HIF-1α, IL-25, IL-33, and TSLP expression levels were upregulated in the non-ECRSwNP and ECRSwNP groups compared with the control group, with the ECRSwNP group having the highest HIF-1α and EDC expression levels. Additionally, HIF-1α was positively correlated with IL-25 and IL-33 in the ECRSwNP group. Meanwhile, treatment with a HIF-1α inhibitor, PX-478, inhibited the hypoxia-induced increase in the mRNA and protein expression of EDCs and type 2 cytokines in HNECs. Similarly, in vivo, PX-478 inhibited EDC expression in the sinonasal mucosa of mice with ECRSwNP. Hypoxia induces EDC expression by upregulating HIF-1α levels, thereby promoting type 2 immune responses and the development of ECRSwNP. Hence, targeting HIF-1α may represent an effective therapeutic strategy for ECRSwNP.

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

Chronic rhinosinusitis (CRS) can be divided into endotypes by functional or pathophysiologic findings. The aim of this study was to analyze the expression of cytokines, prostaglandin (PG) synthases, and their receptors related to the pathogenesis of CRS, especially those contributing to nasal polyp (NP) formation. NPs and uncinate tissue (UT) samples were collected from 90 patients who underwent endoscopic sinus surgery. They included 75 patients with CRS (including 45 with eosinophilic CRS [eCRS] and 30 with non-eCRS) and 15 patients without CRS. Atotal of 30 genes were selected for our original DNA array plate to analyze the levels of expression of 10 cytokines (IFN-γ, IL-4, IL-5, IL-10, IL-13, IL-17A, IL-22, IL-25, IL-33, and TSLP), 4 prostaglandin synthases (prostaglandin D2 [PGD2] synthase, prostaglandin E2 synthase, COX-1, and COX-2), and their 16 receptors. Clustering analysis was performed according to the expression results, and clinical findings of patients from each cluster were investigated. The samples could be divided into 3 clusters. Cluster 1showed elevated levels of expression of IL4, IL5, IL13, TSLP, IL1RL1 (ST2 [an IL-33 receptor]), HPGDS, and GPR44 (CRTH2, a PGD2 receptor); cluster 2 showed elevated levels of expression of IL17A and PTGES; and cluster 3 showed an elevated level of expression of IL25. Regarding clinical features, the main characteristics of each cluster were as follows: NPs from patients with eCRS for cluster 1, NPs and/or UT samples from patients with non-eCRS for cluster 2, and UTs from patients with non-CRS for cluster 3. The results suggest that there are associations between type 2 inflammation/PGD2 and eCRS and also between type 3 inflammation/prostaglandin E2 and non-eCRS.

Body Mass Index and Related Risk Factor of Sinusitis Among Adults in Saudi Arabia: A Cross-Sectional Study.

Chronic rhinosinusitis (CRS) is a widespread condition worldwide that is leading to a significant burden on society in terms of healthcare consumption and productivity loss.Multiple risk factors have been implicated in the pathogenesis of CRS, such as nasal allergies, bronchial asthma, smoking, nasal polyps, and immune system-related diseases. The present study aimed to assess the prevalence of CRS, the most common risk factors, and the association between diabetes, body mass index(BMI), and CRS in Saudi Arabia. A cross-sectional study was conducted through random sampling that included 3602 participants from different regions of Saudi Arabia from November 2022 to January 2023. Electronic questionnaires were used for data collection. A total of 3602 individuals responded to our questionnaires; 948 (26.3%) were diagnosed by physicians as having chronic rhinosinusitis, and 75.1% were females. The majority (41.5%) were between the ages of 18 and 28 years. We found that smoking was significantly associated with sinusitis (OR 2.01, 95% CI 1.23-5.69) (p value 0.003) and that obesity was also significantly associated with sinusitis, 17.0% of persons with sinusitis were obese class I (BMI 30-35 kg/m2); 7.8% were obese class II (BMI>35 kg/m2); and 29.4% were overweight, whereas 45.8% were of normal weight. All percentages differ significantly from persons with normal weight (p value = 0.000). The most common risk factors for sinusitis were nasal allergies (44.4%), stuffy nose (22.8%), and deviation of the nasal septum (19.2%). All percentages differ significantly from persons without comorbidity (p value = 0.000). The present study showed a slight increase in the prevalence of CRS in Saudi Arabia, which is attributable to increased exposure to allergens. The most common risk factors were nasal allergies, nasal blockage, deviation of the nasal septum, and asthma. There was a significant correlation between CRS and BMI in the form of increased prevalence in overweight and obese compared to normal-weight individuals.

EFFECT OF INFLAMMATORY FACTORS IN THE PATHOGENESIS OF CHRONIC RHINOSINUSITIS

Abstract: Both immune mechanisms, involved in inflammatory processes induced by viral and bacterial pathogens or allergy-inducing agents, and non-immune mechanisms play a direct role in the pathogenesis of chronic rhinosinusitis (CRS). Contrary to popular belief, bacterial infection plays a much smaller role. As a rule, this is a secondary process – following the development of inflammatory processes in the mucosa of the paranasal sinuses, its defense mechanisms are disrupted, which promotes the development of infection. Bacterial infection of the paranasal sinuses is associated with the formation of a biofilm responsible for the persistence of rhinosinusitis, or bacterial endotoxins acting as superantigens cause the persistence of the inflammatory process. The main role in the inflammatory process is played by CD4+ and CD8+ T lymphocytes, as the centers regulating cytotoxic and humoral immune responses. They act in various ways, mainly cytotoxic, and as such can interact with virtually all nucleated host cells showing expression of antigens of endogenous origin and through cytokines, mainly pro-inflammatory cytokines, and they increase migration of inflammatory cells into the mucosa of the nasal cavity and paranasal sinuses. The paper discusses in detail the interaction of immunocompetent cells and their impact on chronic inflammatory processes in the mucosa of paranasal sinuses. Atopy is another factor contributing to the CRS, increasing the action of pro-inflammatory cytokines and promoting processes that lead to obstruction of the ostiomeatal complex. The complexity of the clinical picture of the CRS in relation to ongoing research on pathogenesis indicates that it is still not possible to strictly define the phenotypes of the disease.

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

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

Using of herbal mucolytics in the complex therapy of acute and chronic rhinosinusitis

Chronic rhinosinusitis is a polyetiological heterogeneous disease that is characterized by inflammation of the nasal mucosa and paranasal sinuses. The clinical picture of this pathology may include nasal congestion and rhinorrhea. Studies on the pathogenesis of chronic rhinosinusitis have yielded insufficient results, however, a number of factors that predispose to the development of this disease are currently identified according to clinical guidelines. Among these are both anatomical anomalies and some chronic diseases (rhinitis, atopy), immune system disorders (immunodeficiencies), etc. Mucoactive drugs are used in the treatment of acute and chronic rhinosinusitis to restore the transport function of the upper respiratory tract epithelium. Their mechanism of action is aimed at restoring mucociliary clearance. This therapy also affects the viscous discharge, which is produced during rhinosinusitis and accumulates in the paranasal sinuses and nasal cavity, worsening the course of the inflammatory process. Specialists distinguish the following forms of mucoactive drugs: mucolytics, mucokinetics and mucoregulators. The article considers the aspects of the clinical use of herbal mucolytics for the treatment of acute and chronic rhinosinusitis, in the pathogenesis of which the nasal mucosa edema plays a key role. The authors summarise the most conclusive evidence to date on the need to use herbal mucolytics in the complex therapy of acute and chronic rhinosinusitis. The modern topical therapy of acute and chronic rhinosinusitis in the otorhinolaryngology practice is presented. Herbal medicinal products have a proven secretolytic and anti-inflammatory effect, accelerate the relief of symptoms and reduce the recovery time of patients. The clinical guidelines recommend to prescribe these drugs in addition to the complex therapy of rhinosinusitis to patients suffering from ARS and CRS, who has no contraindications.

Autoimmunity: A New Focus on Nasal Polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) has long been considered a benign, chronic inflammatory, and hyperplastic disease. Recent studies have shown that autoimmune-related mechanisms are involved in the pathology of nasal polyps. Activated plasma cells, eosinophils, basophils, innate type 2 lymphocytes, mast cells, and proinflammatory cytokine in polyp tissue indicate the mobilization of innate and adaptive immune pathways during polyp formation. The discovery of a series of autoantibodies further supports the autoimmune nature of nasal polyps. Local homeostasis dysregulation, infection, and chronic inflammation may trigger autoimmunity through several mechanisms, including autoantigens overproduction, microbial translocation, molecular mimicry, superantigens, activation or inhibition of receptors, bystander activation, dysregulation of Toll-Like Receptors (TLRs), epitope spreading, autoantigens complementarity. In this paper, we elaborated on the microbiome-mediated mechanism, abnormal host immunity, and genetic changes to update the role of autoimmunity in the pathogenesis of chronic rhinosinusitis with nasal polyps.