Type 1/type 2 inflammatory cytokines correlate with olfactory function in patients with chronic rhinosinusitis

The causal relationship between autoimmune diseases and rhinosinusitis, and the mediating role of inflammatory proteins: a Mendelian randomization study

Observational studies have linked autoimmune diseases (ADs) with rhinosinusitis (RS) manifestations. To establish a causal relationship between ADs and RS, and to explore the potential mediating role of inflammatory mediators between ADs and RS, we utilized Mendelian randomization (MR) analysis. Using a two-sample MR methodology, we examined the causality between multiple sclerosis (MS), rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriasis (PsO), type 1 diabetes (T1D), Sjogren's syndrome (SS), celiac disease (CeD), Crohn's disease (CD), hypothyroidism (HT), Graves' disease (GD), and Hashimoto's thyroiditis and their association with chronic and acute rhinosinusitis (CRS and ARS, respectively).To achieve this, we employed three distinct MR techniques: inverse variance weighting (IVW), MR-Egger, and the weighted median method. Our analysis also included a variety of sensitivity assessments, such as Cochran's Q test, leave-one-out analysis, MR-Egger intercept, and MR-PRESSO, to ensure the robustness of our findings. Additionally, the study explored the role of inflammation proteins as a mediator in these relationships through a comprehensive two-step MR analysis. Among the ADs, MS, RA, T1D, CeD, and HT were determined as risk factors for CRS. Only CeD exhibited a causal relationship with ARS. Subsequent analyses identified interleukin-10 (IL-10) as a potential mediator for the association of MS, RA and HT with CRS, respectively., while C-X-C motif chemokine 10 levels (CXCL10) and T-cell surface glycoprotein CD6 isoform levels (CD6) were found to influence HT's effect on CRS. Our findings demonstrate a causative link between specific autoimmune diseases and rhinosinusitis, highlighting IL-10, CXCL10, and CD6 as potential mediators in this association.

Efficacy and safety of dupilumab in the treatment of CRSwNP in the real-life setting: a review of the literature

INTRODUCTION

The recent approval of Dupilumab has profoundly revolutionized the management of patients affected by severe and recalcitrant Chronic Rhinosinusitis with Nasal Polyps (CRSwNP). However, a review that summarizes the results of real-life studies and compares them to phase 3 studies SINUS-24 and 52 is still lacking.

MATERIALS AND METHODS

A search of all real-life studies published from 2019 to 2023 was performed. Patients characteristics at baseline and 6 and 12 months after starting Dupilumab were extracted and compared to those from phase 3 trials: age, sex, smoking habits, comorbid asthma and aspirin-exacerbated respiratory disease (AERD), previous endoscopic sinus surgery (ESS), hematic eosinophils and total IgE, NasalAQ2 Polyps Score (NPS), smell, SNOT-22, adverse events (AEs), and response to treatment.

RESULTS

15 papers were included with an overall number of 1658 patients. A higher rate of comorbidities and previous ESS was found in patients from real-life studies. In addition, they had worse smell and SNOT-22 at baseline compared to patients from SINUS-24 and 52. Comorbid and post-ESS patients tended to have a faster NPS and SNOT-22 improvement, although the absolute values were not clinically relevant. A more extensive surgery and a number of ESS ≥ 2 were related to worse olfactory outcomes, probably due to iatrogenic damage. No correlation was found between hematic eosinophils and outcomes. AEs were reported by 12.4% of patients and 2.2% had to discontinue dupilumab. Weight gain was an emergent AE (0.8%), probably related to the restored sense of smell and taste. Non-responders were 3.5% and they were switched to systemic steroid, ESS, or another biologic.

CONCLUSION

Despite some differences in prescription criteria between countries, dupilumab was demonstrated to be effective even in the real-life scenario. However, emerging AEs and possible unknown long-term AEs of a likely lifelong therapy should be considered.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Olfactory Loss in Rhinosinusitis: Mechanisms of Loss and Recovery

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

The interleukin-4/interleukin-13 pathway in type 2 inflammation in chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is predominantly a type 2 inflammatory disease associated with type 2 (T2) cell responses and epithelial barrier, mucociliary, and olfactory dysfunction. The inflammatory cytokines interleukin (IL)-4, IL-13, and IL-5 are key mediators driving and perpetuating type 2 inflammation. The inflammatory responses driven by these cytokines include the recruitment and activation of eosinophils, basophils, mast cells, goblet cells, M2 macrophages, and B cells. The activation of these immune cells results in a range of pathologic effects including immunoglobulin E production, an increase in the number of smooth muscle cells within the nasal mucosa and a reduction in their contractility, increased deposition of fibrinogen, mucus hyperproduction, and local edema. The cytokine-driven structural changes include nasal polyp formation and nasal epithelial tissue remodeling, which perpetuate barrier dysfunction. Type 2 inflammation may also alter the availability or function of olfactory sensory neurons contributing to loss of sense of smell. Targeting these key cytokine pathways has emerged as an effective approach for the treatment of type 2 inflammatory airway diseases, and a number of biologic agents are now available or in development for CRSwNP. In this review, we provide an overview of the inflammatory pathways involved in CRSwNP and describe how targeting key drivers of type 2 inflammation is an effective therapeutic option for patients.

Non-Type 2 and Mixed Inflammation in Chronic Rhinosinusitis and Lower Airway Disease

OBJECTIVE

The aim was to discuss the role of non-type 2 inflammation in patients diagnosed with chronic rhinosinusitis (CRS) and comorbid lower airway disease.

DATA SOURCES

Medline, Embase, National Institute for Health and Care Excellence, TRIP Database, ProQuest, Clinicaltrials.gov, Cochrane Central Registry of Controlled Trials, Web of Science, government and health organizations, and graduate-level theses.

REVIEW METHODS

This scoping review followed PRISMA-ScR guidelines. Search strategy was peer-reviewed by medical librarians. Studies were included if they utilized airway sampling, non-type 2 cytokines, and patients with CRS and lower airway disease.

RESULTS

Twenty-seven from 7060 articles were included. In patients with CRS and comorbid asthma, aspirin-exacerbated respiratory disease (AERD), and chronic obstructive pulmonary disease (COPD)/bronchiectasis, 60% (n = 12), 33% (n = 2), and 100% (n = 1), respectively, demonstrated mixed or non-type 2 endotypes. Comorbid CRS and asthma produced type 1 (n = 1.5), type 2 (n = 8), type 3 (n = 1), mixed type 1/2 (n = 1), and mixed type 1/2/3 (n = 8.5) endotype shifts. AERD demonstrated type 2 (n = 4), mixed type 2/3 (n = 1), and mixed type 1/2/3 (n = 1) endotype shifts. CRS with COPD or bronchiectasis demonstrated a mixed 1/2 (n = 1) endotype shift.

CONCLUSION

Type 2 disease has been extensively reviewed due to advent biologics targeting type 2 inflammation, but outcomes may be suboptimal due to the presence of non-type 2 inflammation. A proportion of patients with CRS and comorbid lower airway disease demonstrated mixed and non-type 2 endotype shifts. This emphasizes that patients with unified airway disease may have forms of inflammation beyond classical type 2 disease which could inform biologic development. Laryngoscope, 134:1005-1013, 2024.

A Decade of Pathogenesis Advances in Non-Type 2 Inflammatory Endotypes in Chronic Rhinosinusitis: 2012-2022

Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by localized inflammation of the upper airways. CRS includes two main phenotypes, namely, CRS with nasal polyps and CRS without nasal polyps. The phenotype-based classification method cannot reflect the pathological mechanism. The endotype-based classification method has been paid more and more attention by researchers. It is mainly divided into type 2 and non-type 2 endotypes. The mechanism driving the pathogenesis of non-type 2 inflammation is currently unknown. In this review, the PubMed and Web of Science databases were searched to conduct a critical analysis of representative literature works on the pathogenesis of non-type 2 inflammation in CRS published in the past decade. This review summarizes the latest evidence that may lead to the pathogenesis of non-type 2 inflammation. It is the main method that analyzing the pathogenesis from the perspective of immunology. Genomics and proteomics technique provide new approaches to the study of the pathogenesis. Due to differences in race, environment, geography, and living habits, there are differences in the occurrence of non-type 2 inflammation, which increase the difficulty of understanding the pathogenesis of non-type 2 inflammation in CRS. Studies have confirmed that non-type 2 endotype is more common in Asian patients. The emergence of overlap and unclassified endotypes has promoted the study of heterogeneity in CRS. In addition, as the source of inflammatory cells and the initiation site of the inflammatory response, microvessels and microlymphatic vessels in the nasal mucosal subepithelial tissue participate in the inflammatory response and tissue remodeling. It is uncertain whether CRS patients affect the risk of infection with SARS-CoV-2. In addition, the pathophysiological mechanism of non-type 2 CRS combined with COVID-19 remains to be further studied, and it is worth considering how to select the befitting biologics for CRS patients with non-type 2 inflammation.

Olfactory dysfunction in chronic rhinosinusitis: insights into the underlying mechanisms and treatments

INTRODUCTION

Olfactory dysfunction (OD) is a typical symptom of chronic rhinosinusitis (CRS), which adversely affects the patient's quality of life and results in mood depression. Studies investigating the impairment of olfactory epithelium (OE) have indicated that inflammation-induced cell damage and dysfunction in OE plays a vital role in the development of OD. Consequently, glucocorticoids and biologics are beneficial in the management of OD in CRS patients. However, the mechanisms underlying OE impairment in CRS patients have not been fully elucidated.

AREAS COVERED

This review focuses on mechanisms underlying inflammation-induced cell impairment in OE of CRS patients. Additionally, the methods used for detection of olfaction and both currently available and potentially new clinical treatments for OD are reviewed.

EXPERT OPINION

Chronic inflammation in OE impairs not only olfactory sensory neurons but also non-neuronal cells that are responsible for regeneration and support for neurons. The current treatment for OD in CRS is mainly aimed at attenuating and preventing inflammation. Strategies for use of combinations of these therapies may achieve greater efficacy in restoration of the damaged OE and consequently better management of OD.

Disturbed microbiota-metabolites-immune interaction network is associated with olfactory dysfunction in patients with chronic rhinosinusitis

Purpose

Olfactory dysfunction (OD) is a debilitating symptom frequently reported by patients with chronic rhinosinusitis (CRS) and it is associated with a dysregulated sinonasal inflammation. However, little information is available about the effect of the inflammation-related nasal microbiota and related metabolites on the olfactory function in these patients. Therefore, the current study aimed to investigate the nasal microbiota-metabolites-immune interactions and their role in the pathogenesis of OD in CRS patients.

Methods

23 and 19 CRS patients with and without OD, respectively, were enrolled in the present study. The "Sniffin' Sticks" was used to measure the olfactory function, while the metagenomic shotgun sequencing and the untargeted metabolite profiling were performed to assess the differences in terms of the nasal microbiome and metabolome between the two groups. The levels of nasal mucus inflammatory mediators were investigated by a multiplex flow Cytometric Bead Array (CBA).

Results

A decreased diversity in the nasal microbiome from the OD group compared to the NOD group was evidenced. The metagenomic analysis revealed a significant enrichment of Acinetobacter johnsonii in the OD group, while Mycoplasma arginini, Aeromonas dhakensis, and Salmonella enterica were significantly less represented (LDA value > 3, p < 0.05). The nasal metabolome profiles were significantly different between the OD and NOD groups (P < 0.05). The purine metabolism was the most significantly enriched metabolic subpathway in OD patients compared with NOD patients (P < 0.001). The expressions of IL-5, IL-8, MIP-1α, MCP-1, and TNF were statistically and significantly increased in the OD group (P < 0.05). All these data, including the dysregulation of the nasal microbiota, differential metabolites, and elevated inflammatory mediators in OD patients demonstrated a clear interaction relationship.

Conclusion

The disturbed nasal microbiota-metabolite-immune interaction networks may be implicated in the pathogenesis of OD in CRS patients and the underlying pathophysiological mechanisms need to be further investigated in future studies.

Expression profiles of east-west highly differentiated genes in Uyghur genomes

It remains unknown and debatable how European-Asian-differentiated alleles affect individual phenotypes. Here, we made the first effort to analyze the expression profiles of highly differentiated genes with eastern and western origins in 90 Uyghurs using whole-genome (30× to 60×) and transcriptome data. We screened 921 872 east-west highly differentiated genetic variants, of which ∼4.32% were expression quantitative trait loci (eQTLs), ∼0.12% were alternative splicing quantitative trait loci (sQTLs), and ∼0.12% showed allele-specific expression (ASE). The 8305 highly differentiated eQTLs of strong effects appear to have undergone natural selection, associated with immunity and metabolism. European-origin alleles tend to be more biasedly expressed; highly differentiated ASEs were enriched in diabetes-associated genes, likely affecting the diabetes susceptibility in the Uyghurs. We proposed an admixture-induced expression model to dissect the highly differentiated expression profiles. We provide new insights into the genetic basis of phenotypic differentiation between Western and Eastern populations, advancing our understanding of the impact of genetic admixture.

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

PURPOSE

To evaluate the putative association between subjective symptoms and eosinophilic inflammation in patients with chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS

A total of 102 patients with CRSwNP who underwent endoscopic sinus surgery were prospectively enrolled. The Sinonasal Outcomes Test-22 scores (SNOT-22), EuroQol 5-dimensional Questionnaire scores (ED-5D), and Lund-Mackay scores by computed tomography (CT) were obtained. Patients were grouped as eosinophilic CRSwNP (eCRSwNP) and non-eosinophilic CRSwNP (neCRSwNP). ECRSwNP was defined if tissue eosinophils of nasal polyps were greater than or equal to 8/HPF according to positive major basic protein (MBP) staining, and neCRSwNP otherwise.

RESULTS

Thirty neCRSwNP and 72 eCRSwNP patients were included. ECRSwNP patients had higher incidences of asthma (p = 0.001), allergic rhinitis (p = 0.001), and ethmoid-to-maxillary opacification ratio on CT scans (p < 0.001), whereas the proportion of purulent discharge (p < 0.001) and maxillary sinus score (p = 0.002) was higher in the neCRSwNP patients. There were no significant differences between patients on the mains of the EQ-5D health utility values and total SNOT-22 score. However, eCRSwNP patients had higher SNOT-22 scores of sneezing (p = 0.006), runny nose (p < 0.001), and ear/facial domain (p = 0.012), and lower scores of thick nasal discharge (p = 0.015) and blockage (p = 0.042). Sneezing, thick nasal discharge, and blockage/congestion of nose were recognized as independent factors of CRSwNP.

CONCLUSION

Sneezing was an independent predictor of eCRSwNP, and thick nasal discharge and blockage/congestion of nose were independent predictors of neCRSwNP.

Pathogenesis and treatment of chronic rhinosinusitis from the perspective of sinonasal epithelial dysfunction

Background

Chronic rhinosinusitis (CRS) is a clinical syndrome primarily characterized by long-term mucosal inflammation of the nasal cavity and sinuses. The pathogenesis of CRS is still unclear due to its high heterogeneity. A number of studies have recently focused on the sinonasal epithelium. Thus, there has been a quantum leap in awareness of the role of the sinonasal epithelium, which is now understood as an active functional organ rather than simply an inert mechanical barrier. Undoubtedly, epithelial dysfunction plays a vital role in the onset and development of CRS.

Objective

In this article, we discuss the potential contribution of sinonasal epithelium dysfunction to CRS pathogenesis and explore a few current and developing therapeutic options targeting the sinonasal epithelium.

Results

Impaired mucociliary clearance (MCC) and an abnormal sinonasal epithelial barrier are usually considered to be the main causative factors in CRS. Epithelial-derived bioactive substances, such as cytokines, exosomes, and complements, play a vital role in the regulation of innate and adaptive immunity and contribute to the pathophysiological alterations of CRS. The phenomena of epithelial-mesenchymal transition (EMT), mucosal remodeling, and autophagy observed in CRS offer some novel insights into the pathogenesis of this disease. In addition, existing treatment options targeting disorder of sinonasal epithelium can help to relieve the main symptoms associated with CRS to some extent.

Conclusion

The presence of a normal epithelium is fundamental for maintaining homeostasis in the nasal and paranasal sinuses. Here, we describe various aspects of the sinonasal epithelium and highlight the contributions of epithelial dysfunction to CRS pathogenesis. Our review provides sound evidence of the need for in-depth study of the pathophysiological alterations of this disease and for the development of novel epithelium-targeting alternative treatments.

Analysis of CRSsNP Proteome Using a Highly Multiplexed Approach in Nasal Mucus

BACKGROUND

Chronic rhinosinusitis without nasal polyps (CRSsNP) represents a phenotype of CRS, whose immunological mechanisms are still unclear. So far there are neither suitable biomarkers to determine the course of the disease nor an individual therapy.

OBJECTIVE

The purpose of this study was to characterize the CRSsNP endotype by identifying and validating non-invasive proteomic biomarkers.

METHODS

A highly-multiplexed proteomic array consisting of antibodies against 2000 proteins was used to identify proteins that are differentially expressed in the nasal mucus of the CRSsNP and control groups (n = 7 per group). The proteins identified to be most differentially expressed were validated in matched nasal mucus samples using western blots and enzyme-linked immunosorbent assay (ELISA). Validation was also done in a second cohort using western blots (CRSsNP n = 25, control n = 23) and ELISA (n = 30 per group). Additionally, immunohistochemistry in CRSsNP and control tissue samples was performed to characterize the selected proteins further.

RESULTS

Out of the 2000 proteins examined, 7 from the most differentially expressed proteins were chosen to be validated. The validation results showed that 4 proteins were significantly upregulated in CRSsNP mucus, including macrophage inflammatory protein-1beta (MIP-1β), resistin, high mobility group box 1 (HMGB1), and forkhead box protein 3 (FOXP3). Cartilage acidic protein 1 (CRTAC1) was not significantly upregulated. Two proteins were significantly downregulated including scavenger receptor class F member 2 (SCARF2) and P-selectin. All proteins selected are mainly associated with inflammation, cell proliferation/differentiation, apoptosis and cell-cell or cell-matrix interaction.

CONCLUSION

Proteomic analysis of CRSsNP and control mucus has confirmed known and revealed novel disease-associated proteins that could potentially serve as a new biosignature for CRSsNP. Analysis of the associated pathways will specify endotypes of CRSsNP and will lead to an improved understanding of the pathophysiology of CRSsNP. Furthermore, our data contribute to the development of a reproducible, non-invasive, and quantitative "liquid biopsy" for rhinosinusitis.

IL-10 family cytokines in chronic rhinosinusitis with nasal polyps: From experiments to the clinic

Chronic rhinosinusitis with nasal polyps (CRSwNP) is considered a nasal sinus inflammatory disease that can be dominated by immune cells and cytokines. IL-10 family cytokines exert essential functions in immune responses during infection and inflammation. Recently, the understanding of the roles of the IL-10 family in CRSwNP is being reconsidered. IL-10 family members are now considered complex cytokines that are capable of affecting epithelial function and involved in allergies and infections. Furthermore, the IL-10 family responds to glucocorticoid treatment, and there have been clinical trials of therapies manipulating these cytokines to remedy airway inflammatory diseases. Here, we summarize the recent progress in the understanding of IL-10 family cytokines in CRSwNP and suggest more specific strategies to exploit these cytokines for the effective treatment of CRSwNP.

Utilization of Nasal Mucus to Investigate the Pathophysiology of Chronic Rhinosinusitis

BACKGROUND

Nasal mucus is proving to be a useful means by which to study the pathogenesis of chronic rhinosinusitis (CRS). Given the increase in publications examining nasal mucus and the lack of a review on this topic, we will focus on this noninvasive approach to studying CRS. Particular attention will be drawn towards inflammatory cytokines and biomarkers and their influence on disease severity.

METHODS

A literature review of papers published in English pertaining to nasal mucus was performed using the PubMed database. The search utilized combinations of the following keywords: sinusitis, polyps, sample collection, nasal mucus, or nasal secretion. Studies solely on acute or bacterial sinusitis, allergic rhinitis, or cystic fibrosis were not included.

RESULTS

A wide variety of materials and methods have been used to collect nasal mucus. Numerous assay types have been performed with the most common being ELISA, cytometric bead array, and proteomics. Most studies have focused on examining the levels of Th1/Th2 cytokines along with chemokines associated with type 2 immunity. Other factors identified include growth factors, senescence-associated proteins, complement, and antimicrobial defenses have also been identified. Nasal mucus cytokines have proven useful in cluster analysis and predicting postoperative improvement in Sino-nasal Outcome Test (SNOT-22) scores. One limitation of the use of nasal mucus is that some studies have suggested that nasal mucus does not always reflect the tissue microenvironment.

CONCLUSIONS

Nasal mucus represents a critical tool by which to examine the sinonasal microenvironment in a noninvasive manner. Unlike studies of tissue, it can be utilized in both surgically and medically managed patients and avoids the trauma of biopsies. However, studies are still needed to determine the most effective method for nasal mucus collection. Studies should also take care to confirm that nasal mucus markers do, in fact, reflect the levels of the product studied in the tissue.

International consensus statement on allergy and rhinology: Olfaction

BACKGROUND

The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O).

METHODS

Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus.

RESULTS

The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies.

CONCLUSION

This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

The Expression and Regulation of Na+-K+-ATPase in Nasal Epithelial Cells of Chronic Rhinosinusitis with Nasal Polyps

OBJECTIVE

Na+-K+-ATPase (NKA) is essential in maintaining cell permeability, reserving potential energy, and preventing cellular edema. Nevertheless, how NKA expression is altered and regulated in chronic rhinosinusitis with nasal polyps (CRSwNPs) remain uncertain. Therefore, the present study aimed to explore the expression and regulation of NKA in CRSwNP.

METHODS

NKA immunolabeling was assessed by the immunohistochemistry method, NKA protein levels were detected with the Western blotting method, and mRNA levels of NKA and aquaporin-5 (AQP5) were assayed by real-time PCR in nasal tissues from CRSwNP and control subjects. The co-localization of NKA with inflammatory cells was evaluated by immunofluorescence staining. In addition, human nasal epithelial cells (HNECs) were cultured and stimulated using various stimulators to evaluate the regulation of NKA.

RESULTS

We found significantly decreased NKA positive cells, NKA protein levels, and mRNA levels of NKA and AQP5 in nasal tissues from CRSwNP patients compared to control subjects, especially in eosinophilic CRSwNP. Furthermore, NKA mRNA levels in HNECs were downregulated by staphylococcal enterotoxin B (SEB), lipopolysaccharides (LPSs), inflammatory cytokine (IFN)-γ, IL-4, IL-13, and IL-1β.

CONCLUSION

NKA and AQP5 expressions were decreased in CRSwNP. NKA in HNECs could be suppressed by SEB, LPS, IFN-γ, IL-4, IL-13, and IL-1β. Impairment of NKA may contribute to the genesis and development of CRSwNP via inducing AQP5 downregulation and edema.