Eosinophilic allergic polyp: a clinically oriented concept of nasal polyp

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.

Immunopathologic Role of Eosinophils in Eosinophilic Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a diverse chronic inflammatory disease of the sinonasal mucosa. CRS manifests itself in a variety of clinical and immunologic patterns. The histological hallmark of eosinophilic CRS (ECRS) is eosinophil infiltration. ECRS is associated with severe disease severity, increased comorbidity, and a higher recurrence rate, as well as thick mucus production. Eosinophils play an important role in these ECRS clinical characteristics. Eosinophils are multipotential effector cells that contribute to host defense against nonphagocytable pathogens, as well as allergic and nonallergic inflammatory diseases. Eosinophils interact with Staphylococcus aureus, Staphylococcal enterotoxin B, and fungi, all of which were found in the tissue of CRS patients. These interactions activate Th2 immune responses in the sinonasal mucosa and exacerbate local inflammation. Activated eosinophils were discovered not only in the tissue but also in the sinonasal cavity secretion. Eosinophil extracellular traps (EETs) are extracellular microbes trapping and killing structures found in the secretions of CRS patients with intact granule protein and filamentous chromatic structures. At the same time, EET has a negative effect by causing an epithelial barrier defect. Eosinophils also influence the local tissue microenvironment by exchanging signals with other immune cells and structural cells. As a result, eosinophils are multifaceted leukocytes that contribute to various physiologic and pathologic processes of the upper respiratory mucosal immune system. The goal of this review is to summarize recent research on the immunopathologic properties and immunologic role of eosinophils in CRS.

Ingrained Insight into Nasal Polyposis; Role of Human Papillomavirus: An Indian Study

Nasal polyposis (NP) are benign lesion of nasal cavity, affecting up to 1-4% of population. It is known to have up to 70% recurrence rate. The underlying pathophysiology is still undetermined. Recent literatures have thrown light on the viral aetiology for NP. To our knowledge this is the first Indian study done, that aims to evaluate the prevalence of Human papillomavirus (HPV) in NP. It was a prospective case control study done among 40 individuals with NP and 40 healthy controls in a tertiary care centre. All the patients were subjected to routine clinical evaluation, investigations prior to proposed surgeries. The mucosal samples after the surgery were subjected to HPV DNA analysis by RT-PCR. Among the cases, the male to female ratio was 1.3:1. The mean age of patients with NP was 39 ± 14.6. The mean serum IgE levels among the case were 154 IU/ml and was significantly higher as compared to controls. Other inflammatory markers such as absolute eosinophil count, erythrocyte sedimentation rate, and neutrophil to leukocyte ration were found to be not significant. There was no HPV DNA detected among both case as well as controls. There seems to be strong association of IgE and NP, suggesting an IgE mediated pathway for its Causation. There is no association of HPV in NP.

Application of Clinical Scores in the Differential Diagnosis of Chronic Rhinosinusitis With Nasal Polyps in a Chinese Population

Background

Eosinophilic (Eos) and non-eosinophilic (non-Eos) chronic rhinosinusitis with nasal polyps (CRSwNP) react differently to clinical treatment, with eosinophilic chronic rhinosinusitis with nasal polyps (Eos CRSwNP) being more likely to recur after surgery.

Objective

To explore the clinical value of the visual analog scale (VAS), nasal endoscopy score (Lund–Kennedy, L–K), computed tomography (CT) score (Lund–Mackay scoring system, L–M), and blood Eos percentage in the differential diagnosis of Eos CRSwNP and non-Eos CRSwNP.

Methods

Ninety-nine patients with CRSwNP were enrolled in this study and assigned to 2 groups (Eos CRSwNP and non-Eos CRSwNP). The blood Eos percentage and VAS, L–K, and L–M scores in the 2 groups of patients were compared. A receiver operating characteristic (ROC) was used to assess the usefulness of VAS, L–K, and L–M scores for differentiating Eos CRSwNP and non-Eos CRSwNP.

Results

There were significantly differences between the Eos CRSwNP group and non-Eos CRSwNP group in the following scores: blood Eos percentage, mean VAS score, olfaction/VAS, general discomfort/L–K, edema score/L–K, olfactory cleft (OC) score via endoscopy, mean L–M score, anteriorethmoid sinus score, posterior ethmoid sinus score, sphenoid sinus score, frontal sinus score, and OC score via CT. An ROC analysis showed that blood Eos percentage had the highest area under the ROC curve (AUC) value (0.749); however, several other scores (olfaction score/VAS, edema score/L–K, and mean L–M score) also had high AUC values. The combination of olfaction score/VAS and blood Eos percentage had the highest clinical convenience score as well as high sensitivity and specificity. A combination of cutoff values for the 2 predictors (blood Eos percentage ≥3.85%, olfaction score/VAS score ≥3) showed a sensitivity of 75.5% and a specificity of 78.0%.

Conclusion

The olfaction score/VAS score and the blood Eos percentage can be combined to differentiate Eos CRSwNP from non-Eos CRSwNP in a Chinese population.

Histopathological Features of Chronic Rhinosinusitis with Nasal Allergic Polyps

Chronic rhinosinusitis with nasal polyps of allergic etiology is one of the most common pathology in the ENT sphere that affect a significant percentage of population. The paper aims to establish the involvement of the allergic component in the genesis of nasal polyposis. The study included 150 nasal polyps from patients hospitalized and operated in the ENT Department of Craiova's Clinical Emergency County Hospital. The biological material was fixed in 10% buffered formalin, processed by classical paraffin embedding technique followed by hematoxylin-eosin staining and it was interpreted in the Pathology Department of the same hospital. We evaluated a number of histopathological parameters that were given severity scores. The most common changes at epithelial level were: basal layer hyperplasia observed in 87 cases (58%), goblet cell hyperplasia in 121 cases (80.66%), basal membrane thickening with values between 10-42μm corresponding to a number of 118 cases (78.66%). The most important stromal changes were edema in 88% and infiltration with eosinophils 100%, indicating the allergic nature of this disease.

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.

Concordant systemic and local eosinophilia relates to poorer disease control in patients with nasal polyps

Background

Eosinophilic inflammation is a major phenotype associated with poorly controlled disease in nasal polyp patients. The difference between systemic and local eosinophilia in relation to disease control is poorly understood.

Objective

To explore whether blood and polyp tissue eosinophil numbers are independent risk factors for poor disease control in patients with nasal polyp.

Methods

By using the electronic medical records database and manual evaluation, 183 nasal polyp patients who had undergone endoscopic sinus surgery at least one year prior to the study with complete data of tissue specimens, baseline blood routine test, nasal endoscopy and sinus computed tomography, were identified and recruited to assess disease control based on the criteria of a European position paper on rhinosinusitis and nasal polyps 2012 (EPOS 2012). Multiple logistic regression model was used to determine the association between blood and tissue eosinophil numbers and risk of poor disease control by adjusting for demographics and comorbidities.

Results

We broke down the cohort into 4 groups according to blood (0.3 ​× ​10⁹/L) and tissue (10%) eosinophils. The patients without eosinophilic inflammation represented the largest group (41.5%). The group with concordant blood and tissue eosinophilia represented the second largest (31.2%), and the patients with isolated tissue (15.3%) or blood (12.0%) eosinophilia were relatively rare. Multiple logistic regression models found blood eosinophil count and tissue eosinophil percentage were independently associated with increased risk for poor disease control after adjustments for covariates related to poor treatment outcome. Furthermore, subjects with concordant blood and tissue eosinophilia had a higher risk for poor disease control than those with isolated blood or tissue eosinophilia.

Conclusion

Concordant blood and tissue eosinophilia relates to a higher likelihood of poor disease control than isolated blood or tissue eosinophilia after adjustment of potential confounders in nasal polyp patients.

Predictive Significance of Charcot–Leyden Crystals for Eosinophilic Chronic Rhinosinusitis With Nasal Polyps

Background

Eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) is a distinct phenotype of chronic rhinosinusitis with nasal polyps (CRSwNP), with many significantly different clinical features from non-eosinophilic chronic rhinosinusitis with nasal polyps (non-ECRSwNP). Thus, identification of subtypes is crucial for precise treatment. Immunohistology is a reliable way to present the subtypes; however, the results mainly depend on the observation of pathologist, and the method with automatic readout and the corresponding biomarkers is lacking.

Objective

The purpose of our research was to explore the predictive value of quantitative reverse transcription polymerase chain reaction (qRT-PCR) as an alternative method and messenger RNA (mRNA) expression of Charcot–Leyden crystals (CLC) as a corresponding target for ECRSwNP, which may benefit the automatized judgment.

Method

CLC mRNA levels in tissue samples from 48 CRSwNP patients and 10 controls were evaluated by quantitative real-time PCR. Hematoxylin and eosin staining was performed for histological assessment of CRSwNP and subtyping as ECRSwNP and non-ECRSwNP. Factors associated with ECRSwNP were determined with logistic regression analysis, the predictive value was presented by a receiver operating characteristic (ROC) curve, and optimal cutoff points of the predictors were identified as the Youden index.

Results

mRNA level of CLC in ECRSwNP was significantly elevated compared to either non-ECRSwNP group or control group, with no significant difference between non-ECRSwNP patients and controls. CLC mRNA levels were positively correlated with percentages of tissue eosinophil and peripheral blood eosinophil ( P < .001, r = .683; P = .003, r = .420, respectively). Logistic regression analysis revealed CLC mRNA level and blood eosinophil percentages were prediagnosis factors ( P = .007, P = .045, respectively) for ECRSwNP. ROC curves analysis indicated the area under the curve (AUC) of CLC mRNA level was 0.948 which was superior to the blood eosinophil percentage (AUC = 0.797; P = .044) as an optimal biomarker to predict ECRSwNP.

Conclusions

CLC mRNA levels based on the qRT-PCR may serve as a reliable and alternative method for the identification of ECRSwNP.

Predictive value of computed tomography in the recurrence of chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a nasal disease with a high tendency for recurrence. The aim of this study was to compare the use of computed tomography (CT) scan with other clinical parameters in predicting the recurrence of CRSwNP.

METHODS

A total of 272 consecutive CRSwNP patients undergoing endoscopic functional sinus surgery were recruited. The demographic characteristics and clinical parameters, including CT scores, level of exhaled nitric oxide, and peripheral eosinophilia, were recorded. The degree of infiltration of inflammatory cells in the sinus mucosa was evaluated.

RESULTS

Two hundred thirty of the 272 patients completed the study (118 patients with recurrence and 112 patients with no recurrence). The average follow-up time was 24 months after the first surgery. The 2 groups were not significantly different with respect to age, gender distribution, comorbid allergy, exhaled oral fractional exhaled nitric oxide levels, nasal obstruction/runny nose/headache/facial pain scores, Lund-Mackay score, peripheral eosinophil percentage, and peripheral eosinophil absolute count. The onset of surgical history and asthma, visual analog scores of CRS, anosmia score, ratio of total ethmoid sinus scores for both sides and maxillary sinus score for both sides (E/M ratio), Lund-Kennedy score, tissue eosinophil percentage, and tissue eosinophil absolute count were significantly higher in the recurrence group. The E/M ratio showed high accuracy as a predictor for CRSwNP recurrence. The cut-off point of 2.55 for E/M ratio indicated the highest predictive value of CRSwNP recurrence.

CONCLUSION

The E/M ratio is a useful predictor for the recurrence of CRSwNP in the Chinese population.

Comparison Between Signature Cytokines of Nasal Tissues in Subtypes of Chronic Rhinosinusitis

PURPOSE

Endotype in chronic rhinosinusitis (CRS) has been established in the last decade. However, the exact immunologic profile of CRS still has controversy because it has a considerable immunologic heterogeneity. Therefore, we investigated various inflammatory mediators according to different nasal tissues in chronic rhinosinusitis and compared them within the same subject.

METHODS

We collected uncinate process mucosa (UP) and nasal polyp (NP) tissues from controls, CRS without NP (CRSsNP) and CRS with NP (CRSwNP). Expression levels of 28 inflammatory mediators including T helper (Th) 1, Th2, Th17, proinflammatory cytokines and remodeling markers were determined by multiplex immunoassay and were analyzed using paired tests as well as principal component analysis (PCA) to investigate endotype in each subtype of CRS.

RESULTS

Signature inflammatory mediators are interleukin (IL)-5, C-C motif chemokine ligand (CCL)-24, monocyte chemoattractant protein (MCP)-4, and vascular cell adhesion molecule (VCAM)-1 in eosinophilic NP, whereas IL-17A, IL-1β, and matrix metallopeptidase (MMP)-9 were detected as signature inflammatory markers in non-eosinophilic NP. Despite differences in inflammatory cytokine profile between eosinophilic and non-eosinophilic NP, the common upregulation of IL-5, CCL-11, IL-23, IL-2Rα, VCAM-1, MMP-3 and MMP-9 were shown in NP compared to UP within the same subject. In the PCA, we observed that Th2 immune response was helpful in discriminating between nasal tissues in subtypes of CRS and that there was a partial overlap between non-eosinophilic NP and eosinophilic NP in terms of Th2 mediators.

CONCLUSIONS

Commonly upregulated mediators in NP were Th2-associated, compared with UP regardless of CRS subtypes, whereas signature markers were distinct in each NP subtype. These findings imply that Th2 inflammatory responses may play a role in the development of NP regardless of CRSwNP subtypes.

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.

Classification of chronic rhinosinusitis according to a nasal polyp and tissue eosinophilia: limitation of current classification system for Asian population

Chronic rhinosinusitis (CRS) can be classified according to the presence of a nasal polyp (NP): CRS with NP (CRSwNP) and CRS without NP (CRSsNP). CRSwNP has characteristics with high infiltration of tissue eosinophilia with a burst of Th2 inflammatory cytokine. However recent findings in Eastern Asia countries suggest that CRSwNP can be divided according to the presence of tissue eosinophilia. Thus, CRSwNP can be classified into eosinophilic and noneosinophilic. Eosinophilic CRSwNP seems to have different immunological and clinical feature compared to noneosinophilic CRSwNP. From the same point of view, CRSsNP can also be divided according to tissue eosinophilia. However, the meaning of this dichotomous categorization in CRS seems to be not quite clear. This review focus on the limitations in current subclassification of CRS according to the presence of NP and tissue eosinophilia and discuss other factors related to tissue remodeling and NP generation which may provide clues for the further understanding of CRS pathogenesis.

Non-Eosinophilic Nasal Polyps Shows Increased Epithelial Proliferation and Localized Disease Pattern in the Early Stage

Background

Non-eosinophilic nasal polyps (NPs) show less inflammatory changes and are less commonly associated with lower airway inflammatory disorders such as asthma, compared with eosinophilic NPs. However, the development of non-eosinophilic NPs which is a predominant subtype in Asian population still remains unclear.

Methods

A total of 81 patients (45 with non-eosinophilic NPs and 36 with eosinophilic NPs) were enrolled. Clinical information and computed tomography (CT), endoscopic, and histological findings were investigated. Tissue samples were analyzed for total IgE levels and for mRNA expression levels of interleukin (IL)-4, IL–5, IL–13, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-17A, IL–22, IL-23p19, transforming growth factor (TGF)-β1, TGF-β2, TGF-β3, and periostin. Immunostaining assessment of Ki–67 as a proliferation marker was performed.

Results

We found that epithelial in-growing patterns such as pseudocysts were more frequently observed in histological and endoscopic evaluations of non-eosinophilic NPs, which was linked to increase epithelial staining of Ki–67, a proliferating marker. Eosinophilic NPs were characterized by high infiltration of inflammatory cells, compared with non-eosinophilic NPs. To investigate the developmental course of each subtype, CT was analyzed according to CT scores and subtypes. Non-eosinophilic NPs showed more localized pattern and maxillary sinus involvement, but lesser olfactory involvement in early stage whereas eosinophilic NPs were characterized by diffuse ethmoidal and olfactory involvement. In addition, high ethmoidal/maxillary (E/M) CT scores, indicating ethmoidal dominant involvement, were one of surrogate markers for eosinophilic NP. E/M CT scores was positively correlated with levels of T_H2 inflammatory markers, including IL–4, IL–5, periostin mRNA expression and total IgE levels in NPs, whereas levels of the T_H1 cytokine, IFN- γ were inversely correlated. Moreover, if the combinatorial algorithm meet the three of the four markers, including IL–5 (<2.379), periostin (<3.889), IFN-γ (>0.316), and E/M ratio (<2.167), non-eosinophilic CRSwNP are diagnosed with a sensitivity of 84.4% and a specificity of 84.8%.

Conclusion

Histologic, immunologic and clinical data suggest that non-eosinophilic NPs showed enhanced epithelial alteration and more localized maxillary involvement. Combination of cutoff value on IL–5, periostin, IFN-γ, and E/M scores may be one of surrogate markers for non-eosinophil NP subtype.

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.

Surgical treatment of nasal polyposis: a comparison between cutting forceps and microdebrider

BACKGROUND

Nasal polyposis (NP) is defined as a specific form of chronic rhinosinusitis (CRS), characterized by bilateral and multifocal polyps. Functional endoscopic sinus surgery represents the gold standard therapy when medical treatment fails. The availability of different tools raises the question of which one provides significant advances in technique and surgical outcome. This study considered the outcome of the surgical treatment of NP in relation to several comorbidities and the surgical device used: the microdebrider versus the Blakesley traditional forceps. Other studies compared the two instruments but did not evaluate the clinical relevance of history of comorbidities such as asthma, allergy, and eosinophilia.

METHODS

A prospective randomized single-blind study was designed to analyze 311 cases of bilateral CRS with NP. Each patient served as his/her own control, meaning that one side was operated on using the Blakesley forceps and the opposite side using the microdebrider. The follow-up period was 13.3 ± 1.2 months.

RESULTS

The Blakesley forceps caused a significantly lower NP recurrence rate than the microdebrider (p < 0.001), which was more effective in preventing synechia formation (p < 0.05). Only asthma was significantly associated with a higher recurrence rate, without being influenced by the instrument used (p < 0.001).

CONCLUSION

The manual instrument allowed for a significantly lower recurrence incidence but yielded a higher rate of synechia formation compared with the microdebrider. Only asthma was significantly associated with a poorer clinical outcome, and gender, age, allergy, and eosinophilia did not affect the surgical prognosis.

Histological Characteristics of Chronic Rhinosinusitis with Nasal Polyps: Recent 10-Year Experience of a Single Center in Daegu, Korea

Background

Chronic rhinosinusitis with nasal polyps (CRSwNP) has various histological patterns and the immunologic characteristics differ between eastern and western patients. This study assessed the histological pattern of Korean NPs and determined whether Korean NP patterns have become westernized.

Methods

Three hundred forty-nine CRSwNP patients were enrolled in this study in 2001 (n = 107), 2006 (n = 111), and 2011 (n = 131). Histological type was categorized as eosinophilic, neutrophilic, seromucinous gland hyperplasia, and stromal atypia types. Medical records were reviewed for their atopic status, olfactory function, and computed tomography (CT) score.

Results

The eosinophilic type was significantly increased in 2011 (62.6%) when compared with 2001 (52.3%) and 2006 7.7%). The incidence of atopic NPs was significantly higher in 2006 (18.9%) and 2011 (21.5%) than in 2001 (14.0%). Although atopic status and CT score were not significantly different among three NP types, anosmia was more common in eosinophilic NPs.

Conclusion

The prevalence of NPs with atopy and eosinophilic NPs has continuously increased in Korea, indicative that the sinonasal disease pattern is becoming similar with western countries.

Does Eosinophilic Inflammation Affect the Outcome of Endoscopic Sinus Surgery in Chronic Rhinosinusitis in Koreans?

Background

The implication of eosinophilic inflammation in chronic rhinosinusitis (CRS) has not been sufficiently studied in Asians. The aim of this study was to evaluate the relationship between eosinophilic inflammation in sinonasal tissues and the surgical outcome of functional endoscopic sinus surgery (FESS) in Koreans.

Methods

A retrospective review of medical records was performed for 347 patients who had undergone bilateral FESS. During FESS, nasal polyp (NP) or sinonasal pathological mucosa was obtained and histopathological analyses were performed. For analyses of surgical outcomes, 173 patients whose follow-up was >12 months were included. The sinonasal cavity was evaluated by endoscopic examination at the last follow-up using a Lund-Kennedy endoscopic scoring system.

Results

Of 347 patients whose tissues were histologically evaluated, 250 (72%) had noneosinophilic CRS. The patients were categorized into four groups according to the presence of NP and eosinophilic inflammation. Of 173 patients, 43 patients (24.9%) had eosinophilic CRS with NP, 15 (8.7%) had eosinophilic CRS without NP, 74 (42.7%) had noneosinophilic CRS with NP, and 41 (23.7%) had noneosinophilic CRS without NP. There were no statistically significant differences in prevalence of allergic rhinitis and asthma and in their preoperative Lund-Mackay scores among four groups. Also, there was no statistically significant difference in the postoperative Lund-Kennedy score between eosinophilic and noneosinophilic CRS groups.

Conclusion

The results suggest that eosinophilic inflammation in CRS may not be related to the surgical outcome in Koreans.

Systemic prednisone administration selectively alters granulocyte subsets in nasal polyps from aspirin-exacerbated respiratory disease and chronic rhinosinusitis patients

BACKGROUND

Nasal polyps (NPs) are hallmark inflammatory lesions of sinusitis. Despite the spectrum of NP conditions, cellular differences between NPs from patients with chronic rhinosinusitis with NPs (CRSwNP) and aspirin-exacerbated respiratory disease (AERD) are poorly understood. NPs are associated with abundant eosinophils; the contributions of neutrophil and basophil granulocytes are less defined. We therefore sought to assess granulocyte subpopulations, and differential effects following prednisone pretreatment, within NPs of CRSwNP and AERD patients.

METHODS

NPs, adjacent ethmoid sinus tissue, and peripheral blood mononuclear cells (PBMCs) were obtained from patients undergoing endoscopic sinus surgery. Samples from 5 cohorts: CRSwNP ± prednisone (n = 6 each), AERD ± prednisone (n = 6 each), and controls (n = 9), were analyzed by high-dimensional flow cytometry to gate granulocyte populations. Specimens were also assessed using immunohistochemistry (IHC) staining.

RESULTS

Systemic prednisone administration was associated with a lower frequency of eosinophils (p < 0.0001, n = 6) in NPs in both CRSwNP and AERD patients, whereas a decrease in neutrophils (p = 0.0070, n = 6) in NPs was only observed in CRSwNP patients after prednisone treatment. In contrast, steroids do not alter basophil proportions (p = 0.48, n = 6) within NPs from either group. No significant shift in granulocyte subsets after steroid treatment was identified in the adjacent ethmoid mucosa or PBMCs from the same patients. Immunohistochemistry (IHC) staining supported these findings.

CONCLUSION

Granulocyte subpopulations are focally affected within NPs by systemic steroid exposure, without notable granulocyte alterations in the surrounding regional tissues. These data provide direct insights into the cellular effects of routine prednisone exposure in CRS patients, and highlight a unique microenvironment present within NP lesions.

Changes in Histological Features of Nasal Polyps in a Korean Population over a 17-year Period

Objective

Nasal polyps can be categorized as eosinophilic or non-eosinophilic, depending on inflammatory cell infiltration. There are geographical differences in the prevalence of types of pathologic polyps. The aim of this study was to evaluate the change in the prevalence of histological subtypes of polyps over time in a Korean population.

Study Design

A retrospective cross-sectional study with histologic analysis.

Setting

A single academic medical center.

Subjects and Methods

A total of 230 patients with nasal polyps were enrolled between 1993-1994 (group A) and 2010-2011 (group B). Specimens were fixed in formalin and embedded into paraffin blocks. Slides were stained with hematoxylin-eosin (H&E) and were subsequently reviewed by 2 of the authors. The numbers of eosinophils per high power field (HPF), as well as other cellular, epithelial, and stromal markers, were recorded.

Results

We compared nasal polyp eosinophil counts according to time period. The average eosinophil count/HPF increased from 6.8 in group A to 19.3 in group B ( P = .006). The prevalence of eosinophilic polyps also increased from 24.0% in group A to 50.9% in group B ( P < .001). Among other histologic markers, lymphocytes, basement membrane thickening, and gland hyperplasia showed significant differences between groups.

Conclusion

After comparison of histopathologic findings of nasal polyps from 1993 and 2011 at 1 academic medical center in Korea, the prevalence of eosinophilic nasal polyps, which are known to be rare among Asians, has significantly increased.