Risk factors for olfactory dysfunction in chronic rhinosinusitis

Propriety of various examinations for subjective symptoms of olfactory disorders

PURPOSE

In Japan, two types of tests for diagnosing olfactory disorders, T and T (T&T) olfactometry and intravenous olfactory tests, are covered by insurance and performed on patients with olfactory disorders. This study examined the validity of these olfactory tests and whether psychophysical or morphological tests are more helpful in evaluating olfactory disorders.

METHODS

We evaluated patients who visited our department and underwent two types of olfaction tests and sinus computed tomography (CT). Data regarding the age, sex, peripheral blood eosinophil percentage, presence of bronchial asthma, diagnoses, olfactory symptom score, results of the two olfactory tests, and CT findings in eligible patients were extracted from medical records and retrospectively reviewed.

RESULTS

One hundred and sixty-three patients underwent all tests during the study period. The results of the T&T olfactometry and intravenous olfactory tests were significantly correlated. However, only the results of T&T olfactometry and olfactory cleft opacification on CT were statistically significant predictors of the olfactory symptom scores.

CONCLUSION

T&T olfactometry and CT evaluations of olfactory cleft opacification helped evaluate olfactory dysfunction. It is important to note that intravenous olfactory tests are best performed with careful control and not blindly to assess olfactory disorders.

Based on the clinical features of cytologically intrinsic chronic rhinosinusitis with nasal polyps

BACKGROUND

The clinical phenotypes of CRS, such as the presence or absence of polyps, cannot well reflect the pathophysiological mechanisms and characteristics of patients. Only by distinguishing the different internal types of CRS can we individualize patients more accurately.

OBJECTIVE

To investigate the clinical characteristics of chronic rhinosinusitis with different cell types (CRSwNP), and to provide a reference for the diagnosis and treatment of CRSwNP.

MATERIALS AND METHODS

The cytological endotypes of CRSwNP were divided into five groups by cluster analysis.

RESULTS

There was a significant difference in the proportion of CRSwNP with different endotypes. There were significant differences in peripheral blood eosinophils, cerebrovascular disease, and unilateral and bilateral nasal polyps among CRSWNP patients with different cytological types.

CONCLUSIONS

Mixed CRSwNP and eosinophilic CRSwNP are the most common, while neutrophilic CRSWNP is the least common. Eosinophilic CRSwNP is more common in bilateral nasal polyps, with a high recurrence rate and a high probability of olfactory dysfunction. Neutrophilic CRSwNP is more common in elderly patients with cardiovascular and cerebrovascular diseases. Compared with total serum IgE, the percentage of eosinophils in peripheral blood is more helpful for the diagnosis of eosinophilic CRSwNP.

Association Between Smoking and Chronic Rhinosinusitis: A Systematic Review and Meta-Analysis

OBJECTIVE

Chronic rhinosinusitis (CRS) is a prevalent inflammatory disease of the upper airway. The impact of smoking on CRS has not been clearly established. We aim to clarify the association between first-hand cigarette smoking and the prevalence and prognoses of CRS.

REVIEW METHODS

PubMed, Embase, SCOPUS, and Cochrane Library were searched from inception until May 15, 2022. Three blinded reviewers selected relevant studies, extracted data, and evaluated study bias following a PROSPERO-registered protocol (CRD42022345585). We used random-effects meta-analyses to pool the prevalence of smoking in CRS, association between smoking status and CRS, and association of smoking with quality of life (QOL) before and after functional endoscopic sinus surgery (FESS). We also performed descriptive analyses of olfactory function, CT scores, and endoscopy scores before and after FESS.

RESULTS

We included 23 cross-sectional studies, 19 cohort studies, two case-control studies, and one prospective clinical trial. The pooled prevalence of ever-smokers was 40% (95% CI = 0.30-0.51) and 33% (95% CI = 0.25-0.43) in patients with and without CRS. Compared to never-smokers, active smokers and past smokers had 1.35 (95% CI = 1.18-1.55) and 1.23 (95% CI = 1.17-1.29) higher odds of having CRS. Among patients with CRS, non-smokers reported higher initial QOL than smokers (standardized mean difference [SMD] = 0.23, 95% CI = 0.11-0.35), although post-FESS QOL was similar (SMD = 0.10, 95% CI = -0.30-0.51). Descriptive analysis found no significant correlations between smoking and post-FESS olfactory function and endoscopy scores.

CONCLUSIONS

Cigarette smoking is associated with higher prevalence and odds of CRS. Clinicians should be aware that smoking predisposes to CRS, but does not negatively impact the rhinologic outcomes of FESS. Laryngoscope, 134:2513-2524, 2024.

Eosinophilic Chronic Rhinosinusitis and Pathogenic Role of Protease

Chronic rhinosinusitis (CRS) is an inflammation of the nasal and paranasal sinus mucosa, and eosinophilic CRS (eCRS) is a subtype characterized by significant eosinophil infiltration and immune response by T-helper-2 cells. The pathogenesis of eCRS is heterogeneous and involves various environmental and host factors. Proteases from external sources, such as mites, fungi, and bacteria, have been implicated in inducing type 2 inflammatory reactions. The balance between these proteases and endogenous protease inhibitors (EPIs) is considered important, and their imbalance can potentially lead to type 2 inflammatory reactions, such as eCRS. In this review, we discuss various mechanisms by which exogenous proteases influence eCRS and highlight the emerging role of endogenous protease inhibitors in eCRS pathogenesis.

Olfactory cleft mucus eosinophil-derived neurotoxin better reflects olfactory loss than blood eosinophil counts in patients with chronic rhinosinusitis

BACKGROUND

Eosinophils are associated with olfactory dysfunction in chronic rhinosinusitis (CRS) and eosinophil-derived neurotoxin (EDN) is a sensitive marker of intense eosinophil activation. This study aimed to analyze olfactory cleft mucus and olfactory mucosa EDN levels and their association with olfactory dysfunction in CRS.

METHODS

We prospectively recruited 150 patients with CRS electing endoscopic sinus surgery and 25 healthy controls. Both superior turbinate biopsy specimens and olfactory cleft mucus were collected to analyze EDN levels. Sniffin' Sticks test scores, olfactory cleft computed tomography (CT) scores, and olfactory cleft endoscopy scale (OCES) were obtained. Multivariable logistic regression analysis was applied to analyze the predictability of EDN levels for olfactory dysfunction in CRS.

RESULTS

Chronic rhinosinusitis with olfactory dysfunction presented significantly higher olfactory mucosa (p = 0.016) and olfactory cleft mucus (p < 0.001) EDN levels than CRS without olfactory dysfunction. Mucus EDN levels were positively correlated with blood eosinophils (r = 0.625, p = 0.002), olfactory cleft CT scores (r = 0.738, p < 0.001), and OCES (r = 0.605, p = 0.004) in CRS. Furthermore, mucus EDN levels were significantly negatively correlated with threshold, discrimination, and identification (TDI) (r = -0.688), olfactory threshold (r = -0.606), olfactory discrimination (r = -0.608), and olfactory identification (r = -0.697) scores. After adjusting for patient demographics and comorbidities, mucus EDN levels were significantly associated with olfactory dysfunction in CRS (odds ratio = 2.162; p = 0.027). Mucus EDN levels showed a significantly better performance for predicting olfactory dysfunction than blood eosinophil counts (area under the curve, 0.873 vs. 0.764, p = 0.024).

CONCLUSION

Olfactory cleft mucus EDN level may be a better biomarker for predicting olfactory dysfunction in CRS than blood eosinophil counts.

Exhaled Nitric Oxide and Olfactory Dysfunction in Patients with Asthma: Association with Chronic Rhinosinusitis

Objectives: Olfactory dysfunction is a clinical sign that is important to detect with coexistent upper airway comorbidities in patients with asthma. This study aimed to investigate the etiology of olfactory dysfunction in patients with asthma and the relationship between fractional exhaled nitric oxide (FeNO) levels. Materials and Methods: This study included 47 asthma patients who were evaluated for olfactory dysfunction at Hiroshima University Hospital between 2012 and 2020. The etiologies of olfactory dysfunction were evaluated, and they were classified according to the FeNO levels of patients with asthma. Results: Olfactory dysfunction was observed in 30 patients with asthma, with chronic rhinosinusitis (77%) being the most prevalent etiology. Eosinophilic chronic rhinosinusitis (ECRS) was the most prevalent etiology of olfactory dysfunction in asthma patients with high FeNO levels (≥25 ppb), while non-eosinophilic chronic rhinosinusitis (NCRS) was the most prevalent etiology in asthma patients with low FeNO levels (<25 ppb). Additionally, the prevalence of ECRS was significantly higher in asthma patients with olfactory dysfunction and high FeNO levels (74%) than in those with either high FeNO levels or olfactory dysfunction and those with low FeNO levels and no olfactory dysfunction (12% and 9%, respectively). Conclusions: We found that ECRS was the predominant cause of olfactory dysfunction in patients with high FeNO levels, while NCRS was more common in those with low FeNO levels. The present study showed that both ECRS and NCRS are common etiologies of olfactory dysfunction in patients with asthma. Additionally, this study supports the link between upper and lower airway inflammation in patients with asthma complicated with olfactory dysfunction.

Relationship of Lesion Location to Postoperative Steroid Use in Eosinophilic Chronic Rhinosinusitis

OBJECTIVES

Eosinophilic chronic rhinosinusitis (ECRS) is known to recur after surgery. The treatment choice for recurrent ECRS, such as oral steroids or biological agents, must be chosen carefully, and identifying the lesion location may be useful. This study aimed to evaluate the postoperative course of ECRS patients and assess the relationship between endoscopic lesion location and postoperative oral steroid use.

METHODS

Patients with chronic rhinosinusitis who underwent bilateral endoscopic sinus surgery from April 2018 to March 2020 were divided into two groups based on the presence or absence of oral steroid use after surgery. The primary endpoint was the lesion location on endoscopic findings during surgery: middle turbinate, middle meatus, superior turbinate, superior meatus, nasal septum, and sphenoethmoidal recess. Subjective symptoms, blood tests, and computerized tomography (CT) findings (Lund-Mackay score) were evaluated as secondary endpoints.

RESULTS

Among 264 patients, 88 were diagnosed histologically with ECRS (mean 48.98 ± 1.40 years, 67 males/21 females). Twenty-three patients were steroid-using, 65 were steroid-free, and six stopped attending their appointments. Patients with sphenoethmoidal recess lesions were significantly more likely to require steroids (p = 0.019). There was a significant association between steroid use and younger age (p = 0.041), olfactory dysfunction (p = 0.021), and all sinuses (Frontal sinus: p < 0.001, Anterior ethmoid sinus: p = 0.002, Posterior ethmoid sinus: p = 0.011, Maxillary sinus: p = 0.018, Sphenoid sinus: p = 0.034, Total score: p < 0.001).

CONCLUSION

A sphenoethmoidal recess lesion was a risk factor for requiring postoperative steroids. Young age, olfactory dysfunction, and preoperative severe CT findings were also significant risk factors.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:2511-2516, 2023.

Understanding the Impact of Chronic Rhinosinusitis with Nasal Polyposis on Smell and Taste: An International Patient Experience Survey

The aim is to understand the patient experience of living with chronic rhinosinusitis with nasal polyposis (CRSwNP), clinician interactions and how symptoms, smell and taste disturbance are managed. An anonymized, online survey was distributed through a UK charity, Fifth Sense, a UK otolaryngology clinic and online support groups to capture qualitative and quantitative data. Data were collected from 1st December 2022 to 1st February 2023. A total of 124 individuals participated. The majority were female (66%) and in the age range of 41-70 years; 74.2% of participants were from the UK with the rest from North America, Europe and Asia. A total of 107 participants declared they had CRSwNP. Rhinologists and general otolaryngology clinicians scored the highest for patient satisfaction whilst general practitioners scored the lowest. Satisfaction with the management of smell and taste disturbance was lower amongst all clinicians compared to overall satisfaction. Ratings correlated with response to therapy and clinician interactions. Respondents reported hyposmia/anosmia to be the most debilitating symptom. Surgery and oral steroids were considered to be effective; however, the benefit lasted less than six months (62%). Hyposmia/anosmia is a key CRSwNP symptom that has limited treatment options and is frequently undervalued by clinicians. There is a need for more effective management options, education and patient support.

A review of current biomarkers in chronic rhinosinusitis with or without nasal polyps

INTRODUCTION

Chronic rhinosinusitis (CRS) is a heterogeneous disease with a variety of cellular and molecular pathophysiologic mechanisms. Biomarkers have been explored in CRS using various phenotypes, such as polyp recurrence after surgery. Recently, the presence of regiotype in CRS with nasal polyps (CRSwNP) and the introduction of biologics for the treatment of CRSwNP has indicated the importance of endotypes, and there is a need to elucidate endotype-based biomarkers.

AREAS COVERED

Biomarkers for eosinophilic CRS, nasal polyps, disease severity, and polyp recurrence have been identified. Additionally, endotypes are being identified for CRSwNP and CRS without nasal polyps using cluster analysis, an unsupervised learning technique.

EXPERT OPINION

Endotypes in CRS have still being established, and biomarkers capable of identifying endotypes of CRS are not yet clear. When identifying endotype-based biomarkers, it is necessary to first identify endotypes clarified by cluster analysis for outcomes. With the application of machine learning, the idea of predicting outcomes using a combination of multiple integrated biomarkers, rather than a single biomarker, will become mainstream.

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.

Olfactory cleft mucus galectin-10 predicts olfactory loss in chronic rhinosinusitis

BACKGROUND

Eosinophils have been reported to be involved in the pathogenesis of olfactory fluctuation in chronic rhinosinusitis (CRS). Galectin-10 is more frequently associated with type 2 inflammation and potentially a sign of intense eosinophil activation.

OBJECTIVE

To explore olfactory cleft mucus and olfactory mucosa galectin-10 level and its association with olfactory dysfunction (OD) in CRS.

METHODS

We prospectively enrolled 50 patients with CRS and 15 healthy controls. Olfactory cleft mucus and superior turbinate biopsy specimens were collected to analyze galectin-10 levels and quantify tissue eosinophils. Psychophysical olfactory testing, olfactory cleft endoscopy scale, and olfactory cleft computed tomography scores were obtained. The predictability of galectin-10 levels for OD in patients with CRS was analyzed by multivariable logistic regression analysis.

RESULTS

Both olfactory cleft mucus and olfactory mucosa galectin-10 levels in patients with CRS with OD were significantly higher than those in patients with CRS without OD (all P < .001). Mucus galectin-10 levels were positively correlated with tissue eosinophils (r = 0.541, P = 0.002), olfactory cleft endoscopy scale (r = 0.498, P = 0.006), and olfactory cleft computed tomography scores (r = 0.432, P = 0.019) in patients with CRS. Mucus galectin-10 levels were negatively correlated threshold, discrimination, and identification (r = -0.589,  P = 0.001), olfactory threshold (r = -0.522, P = 0.003), olfactory discrimination (r = -0.488, P = 0.007), and olfactory identification (r = -0.466, P = 0.011) scores. After adjusting for patient demographics and comorbidities, mucus galectin-10 levels were significantly associated with OD in patients with CRS (odds ratio, 1.299; P = .008). Mucus galectin-10 levels greater than 8.975 ng/mL were the best predictor of OD in CRS.

CONCLUSION

Olfactory cleft mucus galectin-10 is highly associated with OD in CRS.

The Diagnostic and Prognostic Role of Biomarkers in Chronic Rhinosinusitis

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

Association of computed tomography scores to psychophysical measures of olfaction: A systematic review and meta-analysis

BACKGROUND

While various sinus computed tomography (CT) scoring systems have been proposed and used in the literature, no single system has been identified as superior. The strength of associations between CT scoring systems and measures of olfaction also remains unclear.

METHODS

A systematic review of PubMed, CINAHL, Scopus, and the Cochrane Library was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies that reported both CT scores and measures of olfaction in a cross-sectional manner were included.

RESULTS

A total of 37 studies were eligible for meta-analysis. Of 8035 patients with chronic rhinosinusitis, 55.6% were male patients and 53.2% had chronic rhinosinusitis with nasal polyps. Analysis by meta-regression was performed of Lund-Mackay (LM) versus Smell Identification Test-40 (SIT-40; 12 studies), Brief Smell Identification Test (BSIT; 10 studies), Sniffin' Sticks (SS; 10 studies), and Toyota & Takagi (T&T) olfactometry (four studies). A significant moderate association was found between LM and SIT-40 (R²  = 0.612, p < 0.001) and LM and SS (R²  = 0.612, p < 0.001). An association between LM and BSIT approached significance (R²  = 0.461, p = 0.054). No significant associations were noted between LM and T&T olfactometry and between LM and SS when stratified by nasal polyp status.

CONCLUSION

There is a significant moderate association of current CT scoring systems to SIT-40 and SS. Further research should focus on associations of objective measures of olfaction to CT scores of the nasal cavity, sinuses, and olfactory cleft, as well as other disease markers.

Improvement of Subjective Olfactory Dysfunction in Chronic Rhinosinusitis With Nasal Polyps After Endoscopic Sinus Surgery

Objective

Olfactory impairment is a common complaint in patients with chronic rhinosinusitis with nasal polyps (CRSwNP), but the influence of endoscopic sinus surgery (ESS) on olfaction and the factors predicting olfactory impairment are not fully understood. This study aimed to assess the effect of ESS on improving olfactory dysfunction in patients with CRSwNP and to identify factors that predict prognosis.

Methods

A total of 56 patients with CRSwNP reported their self-evaluated olfactory dysfunction score preoperatively and 1 month, 3 months, and 12 months after ESS. Preoperative clinical characteristics, computed tomography (CT) scan, and sinonasal endoscopy examination results were collected before surgery. Additionally, factors that predicted olfactory loss and affected the improvement of olfaction after ESS were evaluated.

Results

Olfactory improvement can be observed 1 month after ESS. A total of 73.2% (41/56) subjects experienced sustained recovery of subjective olfaction with the self-evaluated olfactory dysfunction score improving from 2.04 to 0.64 (P < 0.001) after 12 months. The Lund–Mackay scores (r = 0.593, P < 0.001) and Lund–Kennedy scores (r = 0.265, P < 0.05) correlated with the preoperative olfactory dysfunction score. Multivariate logistic regression analysis revealed that longer duration of olfactory dysfunction, blood eosinophilia, lower Lund–Mackay scores, and peripheral distribution of CT opacification were risk factors that adversely affected the recovery of olfactory function (P < 0.05).

Conclusion

ESS improved self-evaluated olfactory function in patients with CRSwNP. Lund–Mackay scores and Lund–Kennedy scores were correlated with olfactory function prior to surgery, while a longer course of the disease, higher blood eosinophilia, lower Lund–Mackay scores, and peripheral distribution of CT opacification were risk factors for poor olfactory prognosis.

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.

Studies on Clinical Features, Mechanisms, and Management of Olfactory Dysfunction Secondary to Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is one of the most common causes of inflammation of the olfactory system, warranting investigation of the link between chronic inflammation and the loss of olfactory function. Type 2 inflammation is closely related to the clinical features and disease mechanisms of olfactory dysfunction secondary to CRS. Patients with eosinophilic CRS, aspirin-exacerbated respiratory disease, and central compartment atopic disease report increased olfactory dysfunction. Increased levels of interleukin-(IL-)2, IL-5, IL-6, IL-10, and IL-13 in the mucus from the olfactory slit have been reported to be associated with reduced olfactory test scores. The influence of several cytokines and signaling transduction pathways, including tumor necrosis factor-α, nuclear factor-κB, and c-Jun N-terminal kinases, on olfactory signal processing and neurogenesis has been demonstrated. Corticosteroids are the mainstay treatment for olfactory dysfunction secondary to CRS. Successful olfaction recovery was recently demonstrated in clinical trials of biotherapeutics, including omalizumab and dupilumab, although the treatment effect may diminish gradually after stopping the use of the medications. Future studies are required to relate the complex mechanisms underlying chronic inflammation in CRS to dysfunction of the olfactory system.

Evaluation of nasal symptoms to distinguish eosinophilic from noneosinophilic nasal polyps based on peripheral blood

Background: Patients with eosinophilic chronic rhinosinusitis with nasal polyps (eCRSwNP) have poorer outcomes after endoscopic sinus surgery and a higher recurrence rate. Objective: This study aimed to investigate the profile of clinical symptoms of eCRSwNP and the related risk factors. Methods: We prospectively enrolled 298 inpatients with CRSwNP from February 2019 to December 2019. The patients were divided into eCRSwNP and non-eCRSwNP groups based on the percentage of blood eosinophils; the cutoff value was set at 3.05%. Clinical data on questionnaires, visual analog scale (VAS) scores, and laboratory tests were collected. The differences in clinical symptoms, including nasal congestion, rhinorrhea, olfactory disorders, and head and/or facial pain, between the two groups were analyzed to identify the influential factors. Logistic analysis and receiver operating characteristic curves were used to determine the diagnostic benefit for the specific symptom in the patients in the eCRSwNP group. Results: Nasal congestion and olfactory disorders were significantly different between the eCRSwNP and non-eCRSwNP groups. The patients in the eCRSwNP group more frequently had concerns about olfactory disorders (p = 0.002), whereas patients in the non-eCRSwNP group mostly had nasal congestion (p = 0.001). The logistic analysis showed that the primary risk factors for olfactory disorders of eCRSwNP were disease duration (p = 0.014) and alcohol intake (p = 0.012). Olfactory disorders were not associated with the disease course of the eCRSwNP group but were correlated with the disease duration of non-eCRSwNP (p = 0.008). A VAS score for the olfactory disorders of >5.75 could be used to predict the diagnosis of eCRSwNP (area under the curve, 0.674 [95% confidence intervals, 0.559-0.689]; P < 0.001). Conclusion: Olfactory disorder might be the major nasal symptom that could be used to distinguish a peripheral eosinophilia-based definition of eCRSwNP and non-eCRSwNP. The disease duration was a limiting factor for using olfactory to distinguish two subgroups of nasal polyp. The investigation with regard to the accurate time boundary should be further addressed.

Systematic literature review of the epidemiology and clinical burden of chronic rhinosinusitis with nasal polyposis

OBJECTIVES

We conducted a systematic literature review (SLR) to determine the epidemiology and clinical burden of chronic rhinosinusitis with nasal polyps (CRSwNP) and to describe how the addition of biologics has affected outcomes for patients with CRSwNP.

METHODS

The SLR adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Embase, MEDLINE, and Evidence-Based Medicine Reviews databases were searched using OVID. Relevant studies published between 1 January 2008 and 8 February 2019, for epidemiology, and 1 January 2008 and 16 February 2019, for clinical burden, and relevant conference abstracts from 1 January 2017 to 7 March 2019, for epidemiology and 1 January 2017-16 February 2019 for clinical burden were included.

RESULTS

For the epidemiology and clinical burden SLR, 147 and 119 records, respectively, met the inclusion criteria. We found the prevalence of CRSwNP was 1-2.6% and was greater in men. Asthma, allergy, and allergic rhinitis were the most common comorbidities identified. Reported risk factors included asthma, gene polymorphisms, age, and eosinophilia. Studies indicated that dupilumab, mepolizumab, and omalizumab each improved different clinical outcomes. Non-biologics (drugs such as corticosteroids or antibiotics, surgery, or aspirin desensitization) improved clinical outcomes as well.

CONCLUSIONS

CRSwNP is fairly prevalent in the general population. Despite the significant efficacy of existing treatments, several unmet needs remain. The high burden of uncontrolled symptoms, frequent recurrence of nasal polyps after surgery, and long-term adverse effects of oral corticosteroids indicate that new therapies addressing these unmet needs should be developed. Although data on biologics from randomized controlled trials look promising, the efficacy of biologics in the real world has yet to be established. The SLR of the epidemiology and clinical burden of CRSwNP revealed key gaps in the literature. There was a paucity of prevalence data across many geographic areas, and no prevalence projections could be determined. Studies showed varying efficacy of non-biologics and no studies directly compared biologics for efficacy. Data regarding clinical efficacy of agents for eosinophilic CRSwNP or severe CRSwNP were lacking, and these patient populations would be served by more trials.

Comparison of olfactory and taste functions between eosinophilic and non-eosinophilic chronic rhinosinusitis

OBJECTIVE

Most patients with chronic rhinosinusitis (CRS) complain of olfactory and/or taste dysfunctions. However, olfactory and taste dysfunctions depending on the subtype of CRS, classified as eosinophilic CRS (ECRS) and non-eosinophilic CRS (NCRS), have not been clearly reported. Therefore, the purpose of this study was to investigate the clinical features in olfactory and taste functions according to the subtype classified as ECRS and NCRS.

METHODS

We retrospectively analyzed the electronic medical records of patients who underwent endoscopic sinus surgery and were diagnosed with CRS. The patients were divided into ECRS and NCRS groups, according to their Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC) scores. We analyzed demographic characteristics, Sino-Nasal Outcome Test findings, Lund-Mackay score, and the results of previously-validated tests, including the Korean Version of Sniffin' Stick test and chemical gustatory function test.

RESULTS

Patients with ECRS and NCRS had decreased olfactory and taste functions compared to the control group. In particular, the olfactory score of ECRS patients was lower than that of NCRS patients (18.1 ± 9.5 vs 23.7 ± 8.5, respectively, p <0.001). On the other hand, taste scores of ECRS patients were not statistically different compared to NCRS patients (19.1 ± 4.7 vs. 18.3 ± 4.7, respectively, p = 0.166). Olfactory score decreased with increase in JESREC score (r=-0.203, p = 0.002), but it had no correlation with taste score (r = 0.072, p = 0.276).

CONCLUSION

We found a difference in olfactory function but no difference in taste function between patients in ECRS and NCRS groups. These results may provide valuable clinical features in terms of olfactory and taste functions according to the subtypes of CRS.

A novel pathophysiologic link between upper and lower airways in patients with chronic rhinosinusitis: Association of sputum periostin levels with upper airway inflammation and olfactory function

Background

Chronic rhinosinusitis (CRS) and asthma are collectively called unified airway diseases. Periostin has been implicated in the pathophysiologic link of these conditions but only by serum measurements. We sought to investigate sputum levels of periostin and their association with upper airway inflammation and olfactory function in CRS patients.

Methods

We prospectively recruited 56 CRS patients who underwent endoscopic sinus surgery (20 with and 36 without comorbid asthma), and 28 healthy controls between October 2015 and December 2017. Lower and upper airway indices such as sputum periostin levels and eosinophil and neutrophil counts, exhaled fractional nitric oxide (FeNO) levels, and olfactory function were evaluated in the three groups. Radiological severity of CT images and tissue eosinophilia of surgical specimens were also assessed in the CRS patients.

Results

Sputum periostin levels were highest, and olfactory function was most impaired, in the CRS patients with comorbid asthma, followed by those without asthma and controls in this order. CRS with asthma group showed higher sputum eosinophils and FeNO levels than the other two groups, while CRS patients without asthma showed significantly higher neutrophils in sputum than the other two groups. When confined to CRS patients, olfactory dysfunction was correlated with sputum eosinophil counts. Eosinophil counts of nasal polyps showed a significant positive correlation with sputum periostin and FeNO levels. Radiological severity of CRS was correlated with sputum eosinophil counts and FeNO levels.

Conclusions

Periostin levels and inflammatory cells such as eosinophils and neutrophils in the lower airways are increased in patients with CRS, suggesting the presence of mutual interactions between upper and lower airways even if asthma does not coexist. Olfactory dysfunction and eosinophilic nasal polyps may be potential indicators of Th2-driven inflammation in the lower airways.

Trial registration

This study was registered on the UMIN Clinical Trials Registry (Registry ID UMIN000018672).

Predictive markers of long-term recurrence in chronic rhinosinusitis with nasal polyps

BACKGROUND

In last years, many attempts were made to recognize chronic rhinosinusitis with nasal polyps (CRSwNP) phenotypes focusing on identifying relevant key pathogenic molecules. Polyps recurrence rate ranges from 4% to 60%, so it's clear that not all clinical and immunologic factors associated with recurrence are known.

OBJECTIVE

We investigate the inflammatory profile in patients with long term recurrent and non-recurrent CRSwNPs and if a specific profile is associated with recurrence, comparing eosinophilic, neutrophilic and lymphocytic infiltration, as well as IL-5 and IL-8 expression to long term recurrence rate.

METHODS

This prospective study included 44 adult patients with CRSwNP treated with endoscopic sinus surgery between 2008 and 2010. Long term follow-up data (8-10 years) indicated that among 44 patients, 18 (40.1%) experienced long term recurrence of nasal polyposis needing maximal medical treatment or revision surgery. We realized two groups: one with patients who didn't present long term recurrence (26 patients) and another with patients who presented long term recurrence (18 patients) and in both groups eosinophilic, neutrophilic and lymphocytic infiltration and IL-5 and IL-8 expression were measured.

RESULTS

The parameters that reached statistical significance (p < 0.05) comparing the two groups were eosinophilic infiltration and IL-5 expression, whereas neutrophilic and lymphocytic infiltration, as IL-8 expression didn't show any significant difference. Asthma and aspirin intolerance seemed significantly more frequent in patients with recurrence, while allergy presented not statistically significant difference between two groups.

CONCLUSIONS

We can conclude that high eosinophilic infiltration and high IL-5 expression in CRSwNP correlate with higher rate of long term recurrence, while neutrophilic and lymphocytic infiltration, and IL-8 expression don't correlate with it. These findings provide the opportunity to improve our ability to predict the prognosis of surgical intervention, although it is still needed to explore the optimal predictor of outcome in CRSwNP.

Postoperative evaluation of olfactory dysfunction in eosinophilic chronic rhinosinusitis - comparison of histopathological and clinical findings

Background: Olfactory dysfunction in eosinophilic chronic rhinosinusitis (ECRS) is poorly understood. Objective: To compare olfactory mucosal injury due to eosinophil infiltration in ECRS with postoperative olfactory function. Methods: Seventeen ECRS patients (ECRS group) and 18 bilateral rhinosinusitis (non-ECRS group) patients were compared. At 3 and 12 months post-endoscopic sinus surgery (ESS), all patients were evaluated for subjective symptoms (nasal obstruction, nasal discharge and olfactory dysfunction), endoscopic nasal findings, CT score and T&T olfactometer recognition threshold test. The eosinophil count, OMP-positive cells and epithelial erosion in olfactory mucosa collected during ESS were compared with the postoperative olfactory function. Results: The non-ECRS group showed significant improvement in all clinical findings at 3 and 12 months, but the ECRS group showed worsening of the olfactory dysfunction symptoms and T&T olfactometer recognition threshold at 12 months because of recurrence of sinusitis. The groups differed significantly in the ΔT&T value (i.e. pre-ESS T&T recognition threshold - post-ESS T&T recognition threshold) at both 3 and 12 months, and the degree of olfactory improvement differed. Histologically, the ECRS group showed significantly more eosinophils, fewer OMP-positive cells and greater epithelial erosion than the non-ECRS group. Conclusions: Eosinophilic inflammation was thought to cause olfactory mucosal injury/dysfunction.

Highlights of eosinophilic chronic rhinosinusitis with nasal polyps in definition, prognosis, and advancement

Background

Tissue eosinophils are characteristic of inflammation in most but not all patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and may be useful for defining subgroups and making treatment choices. However, no consistent diagnostic criteria for CRSwNP with eosinophilic inflammation have been established.

Methods

Related literature review was performed and current developments in the diagnosis of eosinophilic CRSwNP were summarized. Details in histopathology, definition of tissue eosinophilia, eosinophil as an indicator of disease recurrence, eosinophilic shift, and related biomarkers in CRSwNP are included in this review article.

Results

Mucosal eosinophilia exhibits significant geographic and ethnic differences and may increase over time. Tissue eosinophilia can be defined using a cutoff value based on reference values from healthy mucosa, but typical disease‐specific values should also be employed to increase sensitivity and specificity for clinical use. Recent developments highlight the diagnostic criteria for eosinophilic CRSwNP based on cluster analysis, which were also associated with clinical outcomes. Additionally, some promising eosinophil‐relevant biomarkers, such as eosinophilic cation protein and interleukin 5 (IL‐5), may be clinically applied as diagnostic or predictive tools for CRSwNP in the future.

Conclusion

Sinonasal tissue eosinophilia is present in a majority of CRSwNP patients but is currently more common in the West than in the East. Cutoff values of eosinophils as the diagnostic criteria of eosinophilic CRSwNP are subject to change with geographic and ethnic differences over time. It will be important to identify validated eosinophil‐related biomarkers in different continents/countries for future research and for the introduction of precision medicine.

Long-term postoperative control of eosinophilic chronic rhinosinusitis recurrence by inserting a steroid-eluting, sinus-bioabsorbable device reduces the dosage of oral steroid

OBJECTIVE

We employed a steroid-eluting, sinus-bioabsorbable device for local treatment after surgery for eosinophilic chronic rhinosinusitis (ECRS). One year later, we investigated its efficacy in suppressing recurrence and reducing the use of oral steroids.

METHODS

At one year after ECRS surgery, both 18 cases treated with a postoperative steroid-eluting, sinus-bioabsorbable device (Post-ST group) and 25 cases receiving conventional postoperative therapy (Post-Con group) showed significant improvement in the nasal symptoms (nasal obstruction, nasal discharge and olfactory dysfunction), CT score and threshold test (discrimination test).

RESULTS

The olfactory dysfunction, CT score and threshold test were significantly improved in the Post-ST group compared with the Post-Con group, but the polyp score was not. The mean total number of oral steroid tablets ingested during one year after surgery was 24.3±2.8 tablets in the Post-ST group, which was significant lower than the 36.3±3.7 tablets used in the Post-Con group.

CONCLUSION

The above results indicate that insertion of a steroid-eluting, sinus-bioabsorbable device after ECRS surgery can reduce the oral steroid intake while maintaining long-term suppression of disease recurrence.

Chronic rhinosinusitis and endoscopic sinus surgery

Olfactory dysfunction is a major symptom reported by patients with chronic rhinosinusitis (CRS). Surgical treatment of this disease requires close surveillance of such dysfunction because of wide ranging implications for safety, quality of life, and impact on the flavor of foods and beverages. This review highlights key findings regarding the influences of endoscopic sinus surgery (ESS) on olfactory function across the unique presentations of CRS. Such findings provide information useful for informing patients of potential complications and for obtaining informed consent prior to surgical intervention. ESS has been shown to improve olfaction across all types of CRS as assessed through quantitative testing and subjective reports. The presence of nasal polyposis (NP) and eosinophilia have been identified as predictors of significant postoperative olfactory improvement. When indicated, judicious partial resection of the middle turbinate may result in improved olfactory function without a risk of long term complication. Careful attention to the olfactory cleft and frontal sinus recess are important in limiting olfactory complications by avoiding indiscriminate disruption of olfactory epithelium. Given the chronic nature of the disease, surveillance of olfactory function in patients with CRS is a lifelong activity that will evolve as emerging technologies become available.

Usefulness of our proposed olfactory scoring system during endoscopic sinus surgery in patients with chronic rhinosinusitis

INTRODUCTION

The primary aim of the current study was to examine the usefulness of our proposed olfactory scoring system in chronic rhinosinusitis (CRS) patients with olfactory disorders (n = 213) receiving endoscopic sinus surgery (ESS).

MATERIALS AND METHODS

Analyzed patients were divided into two groups: an eosinophilic CRS (ECRS) group (n = 153); and a non-ECRS group (n = 60). The T&T recognition threshold test was used to evaluate olfaction at baseline and at 3 and 12 months after ESS. Patients with mean recognition threshold < 2.0 at 3 or 12 months or with a decrease of ≥ 1.0 as compared with baseline were defined as showing clinical improvement. We scored mucosal conditions as normal (0 points), edema (1 point), and polyp (2 points) at the canopy of olfactory cleft (OC), middle and superior turbinates, superior nasal meatus, and sphenoethmoidal recess during ESS. The total score of OCs (SOCs) was calculated (range 0-20 points). We compared SOCs between ECRS and non-ECRS groups. Factors related to olfactory improvement were also investigated using uni- and multivariate analyses.

RESULTS

SOCs in the ECRS and non-ECRS groups showed significant correlations with mean recognition thresholds at baseline and at 3 and 12 months. In the multivariate analysis for predicting improvement of mean recognition threshold, lower SOCs were significantly associated with olfactory improvement factors at 3 and 12 months postoperatively in the ECRS group.

CONCLUSION

SOCs appears promising for estimating olfactory prognosis after ESS in CRS patients.

Superior turbinate eosinophilia correlates with olfactory deficit in chronic rhinosinusitis patients

OBJECTIVE

To evaluate if molecular markers of eosinophilia in olfactory-enriched mucosa are associated with olfactory dysfunction.

STUDY DESIGN

Cross-sectional study of tissue biopsies from 99 patients, and an additional 30 patients who underwent prospective olfactory testing prior to sinonasal procedures.

METHODS

Tissue biopsies were processed for analysis of inflammatory markers using quantitative real time polymerase chain reaction (qRT-PCR). Ipsilateral olfactory performance was assessed using the Sniffin' Sticks (Burghart, Wedel, Germany) threshold component and the University of Pennsylvania Smell Identification Test (Sensonics, Haddon Heights, NJ). Age-adjusted data was correlated with inflammatory marker expression and clinical measures of obstruction from computed tomography and endoscopy.

RESULTS

Gene expression of the eosinophil marker CLC (Charcot Leyden crystal protein) was elevated in superior turbinate (ST) tissue in chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) compared to ST and inferior turbinate tissue in CRS without nasal polyps (CRSsNP) and control patients (all P < 0.001, respectively). CLC in ST tissue was correlated with IL-5 and eotaxin-1 expression (all P < 0.001; P = 0.65, and 0.49, respectively). CLC expression was strongly correlated with eosinophilic cationic protein levels (P < 0.001; r = -0.76), and ST CLC expression was inversely related to olfactory threshold (P = 0.002, r = -0.57) and discrimination scores (P = 0.05, r = -0.42). In multiple linear regression of CLC gene expression, polyp status, and radiographic and endoscopic findings with olfactory threshold, CLC was the only significantly correlated variable (P < 0.05).

CONCLUSION

Markers of eosinophils are elevated in the ST of patients with CRSwNP and correlate with olfactory loss. These findings support the hypothesis that olfactory dysfunction in CRS correlates local eosinophil influx into the olfactory cleft.

LEVEL OF EVIDENCE

NA. Laryngoscope, 127:2210-2218, 2017.

Sensation of smell and taste during intravenous injection of iodinated contrast media in CT examinations

OBJECTIVE

To assess the incidence and types of sensation of smell and taste during i.v. injection of five kinds of contrast media (CM) in CT examinations.

METHODS

735 patients who underwent contrast-enhanced CT (CE-CT) between 14 March 2016 and 5 April 2016 were enrolled. Medical staff asked patients whether they felt heat sensation and sensation of smell and taste during i.v. injection of CM (one of the following: iopromide, iomeprol, iopamidol, iohexol and ioversol) after their CE-CT. If the patients stated having felt the sensation of smell or taste, they were also asked what kind of smell or taste they sensed. Next, 30 ml of each CM was poured into high-purity pet cups for radiological technologists to smell directly. Radiological technologists were asked whether or not each CM had any smell.

RESULTS

The sensations of smell and taste incidence for iopromide were 24.3% and 18.9%, respectively, which were significantly higher than those for other CM (p < 0.05). The highest incidence of the sensation of smell was medicine-ish, and the most frequently noted taste was bitterness. All radiological technologists could directly smell only iopromide, which has an ether group on a side chain and fewer hydroxyl groups.

CONCLUSION

Iopromide showed a higher incidence of sensation of smell and taste than other CM. Advances in knowledge: This was the first investigation of sensation of smell and taste during i.v. injection of CM, and a specific CM showed a higher incidence, which is suspected to be due to its chemical structure.

Chronic Rhinosinusitis-Related Smell Loss: Medical And Surgical Treatment Efficacy

Chronic rhinosinusitis (CRS) is an inflammatory disorder of the nasal cavities and paranasal sinuses. Olfactory dysfunction is a common manifestation of CRS and one of its cardinal diagnostic features. A decreased sense of smell can have a profound impact on a CRS patient's quality of life and overall wellbeing. The treatment of CRS-associated olfactory dysfunction includes a wide range of medical interventions, including anti-inflammatory and antibiotic medications, and surgical interventions, including endoscopic sinus and nasal surgery. The evidence and treatment efficacy for these interventions is quite varied. This review provides a summary of the efficacy of the medical and surgical therapeutic options for CRS-associated olfactory dysfunction.

A pilot study of symptom profiles from a polyp vs an eosinophilic-based classification of chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is likely a biologically heterogeneous disease process. Current guidelines propose subclassification using polyp status while others propose using mucosal eosinophilia. We hypothesized that appropriate CRS subclassification would increase homogeneity of baseline symptoms, and identify characteristic symptoms of each subtype.

METHODS

A total of 57 CRS patients undergoing surgery prospectively completed a preoperative battery of 73 questions relating to symptoms including the 22-item Sino-Nasal Outcome Test (SNOT-22) and 29-item Patient-Reported Outcomes Measurement Information System (PROMIS-29) general quality of life (QOL) measures. Eosinophilic cationic protein (ECP) levels were determined from ethmoid, uncinate, and polyp tissue homogenates using enzyme-linked immunosorbent assay (ELISA) and normalized to total protein. Patients were classified as eosinophilic (eCRS) or non-eosinophilic (neCRS) using a 95th percentile threshold established from control tissue from 82 patients without CRS. Separate pairwise comparisons were performed on patient-reported symptoms using polyp and eosinophilic status.

RESULTS

Of the 57 patients, 28 had CRS with nasal polyps (CRSwNP); 27 of 57 patients had eCRS (CRSwNP, n = 21; CRS without nasal polyps [CRSsNP], n = 6). CRSwNP patients had increased need to blow nose, frequency of nasal congestion, more severe difficulty breathing through nose, more severe nasal discharge, but less cough (p < 0.05). eCRS patients had more bothersome loss of taste/smell, ear pain, sneezing, severe difficulty breathing through nose, and severe nasal congestion compared to neCRS patients (p < 0.05).

CONCLUSION

Subclassifying CRS with symptoms alone is difficult with neither polyp status nor eosinophilia giving a distinctive clinical symptom profile. However, certain symptoms may help otolaryngologists identify CRS subtypes, which may help guide future treatments. Further validation and evaluation of prognosis following treatment is required to evaluate appropriate means of subclassifying CRS.

Predictive significance of tissue eosinophilia for nasal polyp recurrence in the Chinese population

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) remains a challenging clinical entity with its propensity for recurrence. Tissue eosinophilia is a hallmark of CRSwNP, and its role in polyp recurrence is a subject of much investigation.

OBJECTIVE

The aim of this study was to evaluate the association between clinical parameters, especially tissue eosinophilia and polyp recurrence, and to identify the optimal cutoff value of tissue eosinophilia as a predictor for polyp recurrence in Chinese subjects.

METHODS

Overall, 387 patients with CRSwNP were enrolled in this retrospective analysis and postoperative follow-up for polyp recurrence was over a period that lasted >24 months (mean [standard deviation], 34.03 ± 4.95 months). The baseline demographic and clinical features and the preoperative computed tomography were compared, and mucosal specimens obtained at endoscopic sinus surgery were assessed for inflammatory cells by using histocytologic staining. Predictive factors associated with polyp recurrence were analyzed by logistic regression analysis, and optimal cutoff points of the predictors were determined by receiver operating characteristic curves and the Youden index.

RESULTS

A total of 55.3% patients (214/387) experienced recurrence. Tissue eosinophilia markedly outweighed other parameters and correlated with polyp recurrence. Receiver operating characteristic curves indicated that a cutoff value of 27% tissue eosinophils predicted recurrence with 96.7% sensitivity and 92.5% specificity (area under the curve = 0.969; p < 0.001); and an absolute count of 55 eosinophils per high power field predicted recurrence with 87.4% sensitivity and 97.1% specificity (area under the curve = 0.969; p < 0.001).

CONCLUSION

A tissue eosinophil proportion of >27% of total cells or a tissue eosinophil absolute count of >55 eosinophils per high power field may act as a reliable prognostic indicator for nasal polyp recurrence within 2 years after surgery.

Eosinophilic chronic rhinosinusitis in East Asians

Chronic rhinosinusitis (CRS) is a common disease worldwide, with a prevalence rate of 5%-15% in the general population. CRS is currently classified into two types: CRS with and without nasal polyps. CRS may also be divided into eosinophilic CRS (ECRS) and non-ECRS subtypes based on the presence of tissue eosinophilic infiltration or not. There are significant geographic and ethnic differences in the tissue eosinophilic infiltration, which is predominant in Western white patients and less common in East Asians, despite an increasing tendency for its prevalence in East Asia countries. ECRS differs significantly from non-ECRS in clinical characteristics, treatment outcomes and strategies, and underlying pathogenic mechanisms. ECRS commonly demonstrates more severe symptoms, polyp diseases with a higher incidence of bilateral polyps and sinonasal diseases on computed tomography, and the increase in blood eosinophils. ECRS is considered a special and recalcitrant subtype of CRS, commonly with poor treatment outcomes compared to non-ECRS. The differentiation of specific subtypes and clinical features of CRS will be important for developing novel treatment strategies and improving treatment outcomes for individual phenotypes of CRS. This review discusses clinical features, diagnosis, treatment and prognosis of ECRS in East Asians.

Interferon gamma causes olfactory dysfunction without concomitant neuroepithelial damage

BACKGROUND

Olfactory loss is a debilitating symptom of chronic rhinosinusitis (CRS). The pathophysiology of inflammatory olfactory dysfunction likely involves both conductive and sensorineural components. To study the interaction of CRS-associated inflammatory cytokines with the olfactory epithelium (OE), a transgenic mouse model was developed that allows temporally-controlled local gene expression. Interferon-gamma (IFN-γ) is a prototypical T helper 1 (Th1) cytokine linked to nonpolypoid CRS (CRSsNP), as well as sinonasal viral and bacterial infections. In this study, the effects of chronic IFN-γ expression on olfactory histology and function were investigated.

METHODS

IFN-γ secretion by olfactory sustentacular cells was induced in the transgenic mouse. Viability and gross behavior were unaffected. Mice were euthanized after 6 weeks of IFN-γ expression, and olfactory tissue was studied by histology, immunohistochemistry, and electro-olfactography (EOG). Findings were compared with uninduced littermates.

RESULTS

IFN-γ expression did not result in alteration of the normal histologic architecture of the neuroepithelium or lamina propria. However, EOG recordings demonstrated a significant decrease in odorant responses after IFN-γ expression. In addition, a marked increase in submucosal CD45-positive cells was observed, the majority of which were CD3-positive and CD4-positive lymphocytes.

CONCLUSION

Chronic IFN-γ expression in the mouse OE results in diminished odorant responsiveness, despite the absence of inflammatory tissue damage. This suggests a direct effect of IFN-γ on olfactory neuron function that may underlie olfactory loss in CRSsNP or viral infections. The infiltration of submucosal lymphocytes raises the possibility that other downstream cytokines also contribute to olfactory dysfunction.

Structural organization and cellular localization of tuftelin-interacting protein 11 (TFIP11)

Tuftelin-interacting protein (TFIP11) was first identified in a yeast two-hybrid screening as a protein interacting with tuftelin. The ubiquitous expression of TFIP11 suggested that it might have other functions in non-dental tissues. TFIP11 contains a G-patch, a protein domain believed to be involved in RNA binding. Using a green fluorescence protein tag, TFIP11 was found to locate in a novel subnuclear structure that we refer to as the TFIP body. An in vivo splicing assay demonstrated that TFIP11 is a novel splicing factor. TFIP11 diffuses from the TFIP body following RNase A treatment, suggesting that the retention of TFIP11 is RNA dependent. RNA polymerase II inhibitor (-amanitin and actinomycin D) treatment causes enlargement in size and decrease in number of TFIP bodies, suggesting that TFIP bodies perform a storage function rather than an active splicing function. The TFIP body may therefore represent a new subnuclear storage compartment for splicing components.