Histopathologic parameters in chronic rhinosinusitis with nasal polyposis: impact on quality of life outcomes

ALOX15+ M2 macrophages contribute to epithelial remodeling in eosinophilic chronic rhinosinusitis with nasal polyps

BACKGROUND

Epithelial remodeling is a prominent feature of eosinophilic chronic rhinosinusitis with nasal polyps (eCRSwNP), and infiltration of M2 macrophages plays a pivotal role in the pathogenesis of eCRSwNP, but the underlying mechanisms remain undefined.

OBJECTIVE

We sought to investigate the role of ALOX15+ M2 macrophages in the epithelial remodeling of eCRSwNP.

METHODS

Digital spatial transcriptomics and single-cell sequencing analyses were used to characterize the epithelial remodeling and cellular infiltrate in eCRSwNP. Hematoxylin and eosin staining, immunohistochemical staining, and immunofluorescence staining were used to explore the relationship between ALOX15+ M2 (CD68+CD163+) macrophages and epithelial remodeling. A coculture system of primary human nasal epithelial cells (hNECs) and the macrophage cell line THP-1 was used to determine the underlying mechanisms.

RESULTS

Spatial transcriptomics analysis showed the upregulation of epithelial remodeling-related genes, such as Vimentin and matrix metalloproteinase 10, and enrichment of epithelial-mesenchymal transition (EMT)-related pathways, in the epithelial areas in eCRSwNP, with more abundance of epithelial basal, goblet, and glandular cells. Single-cell analysis identified that ALOX15+, rather than ALOX15-, M2 macrophages were specifically highly expressed in eCRSwNP. CRSwNP with high ALOX15+ M2THP-1-IL-4+IL-13 macrophages had more obvious epithelial remodeling features and increased genes associated with epithelial remodeling and integrity of epithelial morphology versus that with low ALOX15+ M2THP-1-IL-4+IL-13 macrophages. IL-4/IL-13-polarized M2THP-1-IL-4+IL-13 macrophages upregulated expressions of EMT-related genes in hNECs, including Vimentin, TWIST1, Snail, and ZEB1. ALOX15 inhibition in M2THP-1-IL-4+IL-13 macrophages resulted in reduction of the EMT-related transcripts in hNECs. Blocking chemokine (C-C motif) ligand 13 signaling inhibited M2THP-1-IL-4+IL-13 macrophage-induced EMT alteration in hNECs.

CONCLUSIONS

ALOX15+ M2 macrophages are specifically increased in eCRSwNP and may contribute to the pathogenesis of epithelial remodeling via production of chemokine (C-C motif) ligand 13.

Tissue Eosinophilia is Superior to an Analysis by Polyp Status for the Chronic Rhinosinusitis Transcriptome: An RNA Study

OBJECTIVE

RNA sequencing (transcriptomics) is used to study biological pathways. However, the yield of data depends on comparing well-characterized cohorts. We compared tissue eosinophilia versus nasal polyp (NP) status as the metric to characterize transcriptomic mechanisms at play in eosinophilic and non-eosinophilic chronic rhinosinusitis (CRS) versus controls.

METHODS

RNA sequencing was conducted on sinonasal tissue samples of CRS and controls. Analyses were conducted based on polyp status [with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP)] as well as tissue eosinophil levels per high power field (eos/hpf)[non-eosinophilic (<10 eos/hpf, neCRS) or eosinophilic (≥10 eos/hpf, eCRS)]. The yield of differentially expressed genes (DEGs) and biological pathways through Ingenuity Pathway Analysis (IPA) were compared.

RESULTS

CRS tissue differed from controls by 736 statistically significant DEGs. Both NP status and tissue eosinophilia were effective in differentiating CRS from controls and into two distinct subgroups. Statistically significant DEGs identified when comparing CRS by NP status were 60, whereas 110 DEGs were identified using eosinophil cutoff ≥10 and <10 eos/hpf. Additionally, heatmaps showed greater homogeneity within each CRS subgroup when analyzed by tissue eosinophilia versus NP status. On IPA, the IL-17 signaling pathway was significantly different only by tissue eosinophilia status, not NP status, being higher in CRS <10 eos/hpf.

CONCLUSION

Tissue eosinophilia is superior to an analysis by NP status for the study of CRS transcriptome by RNA sequencing in identifying DEGs. Classification of CRS samples by eosinophil counts agnostic of NP status may offer advantageous insights into CRS pathogenetic mechanisms.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:2480-2489, 2023.

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.

Endotyping Difficult-to-Treat Chronic Rhinosinusitis with Nasal Polyps by Structured Histopathology

INTRODUCTION

This study aimed to identify the histopathologic characteristics associated with difficult-to-treat chronic rhinosinusitis with nasal polyps (CRSwNPs), enabling physicians to predict the risk of poor outcome after endoscopic sinus surgery (ESS).

METHODS

A prospective cohort study performed at the First Affiliated Hospital of Sun Yat-sen University between January 2015 and December 2018 with CRSwNP patients who underwent ESS. Polyp specimens were collected during surgery and were subjected to structured histopathological evaluation. Difficult-to-treat CRSwNPs were determined at 12-15 months post-operation according to the European Position Paper. Multiple logistic regression model was used to assess the association between histopathological parameters and the difficult-to-treat CRSwNP.

RESULTS

Among 174 subjects included in the analysis, 49 (28.2%) were classified with difficult-to-treat CRSwNP, which had higher numbers of total inflammatory cells, tissue eosinophils, and percentages of eosinophil aggregates and Charcot-Leyden crystals (CLC) formation but a lower number of interstitial glands than the nondifficult-to-treat CRSwNP. Inflammatory cell infiltration (adjusted OR: 1.017), tissue eosinophilia (adjusted OR: 1.005), eosinophil aggregation (adjusted OR: 3.536), and CLC formation (adjusted OR: 6.972) were independently associated with the difficult-to-treat outcome. Furthermore, patients with tissue eosinophil aggregation and CLC formation had an increasingly higher likelihood of uncontrolled disease versus those with tissue eosinophilia.

CONCLUSION

The difficult-to-treat CRSwNP appears to be characterized by increased total inflammatory infiltrates, tissue eosinophilia, eosinophil aggregation, and CLC formation in structured histopathology.

Molecular and Clinical Predictors of Quality of Life in Chronic Rhinosinusitis with Nasal Polyps

(1) Background: Factors influencing the quality of life (QoL) of patients with chronic rhinosinusitis with nasal polyposis (CRSwNP) are poorly understood. We set out to determine the predictive factors on patients' QoL using the Sino-Nasal Outcome Test-22 (SNOT-22); (2) Methods: An ambispective analysis of data from patients diagnosed with CRSwNP in our institution. All the patients underwent a nasal polyp biopsy and completed the SNOT-22 questionnaire. Demographic and molecular data as well as the SNOT-22 scores were collected. Patients were classified in six subgroups considering the presence of asthma, non-steroidal drugs (NSAID) intolerance and corticosteroid resistance; (3) Results: The mean SNOT-22 score was 39. Considering the clinical parameters, the SNOT-22 value was significantly associated with NSAID intolerance (p = 0.04) and the endoscopic polyp score (p = 0.04). A high SNOT-22 value was also correlated with high tissue eosinophilia (p = 0.01) and high IL-8 expression; (4) Conclusions: Eosinophilia, IL-8 expression and NSAID intolerance can be used as predictors of worse QoL in patients with CRSwNP.

Interleukin-19 upregulates fibronectin and collagen I expression via the NF-κB-Smad2/3 pathway in fibroblasts of patients with chronic rhinosinusitis

BACKGROUND

Tissue remodeling is a prominent characteristic of chronic rhinosinusitis (CRS). Excess deposition of fibronectin (FN) and collagen (Col) I by fibroblasts is crucial for the pathologic tissue remodeling in CRS without nasal polyps (CRSsNP). Increased interleukin (IL)-19 level in patients with CRS had been demonstrated in our previous studies. Here, we aimed to evaluate the role of IL-19 in mediating FN and Col I expression in CRS.

METHODS

Nasal mucosal tissue samples were collected from patients with CRS with nasal polyps (CRSwNP), CRSsNP, and controls. The expression of IL-19, vimentin, FN, and Col I were detected using immunohistochemistry and immunofluorescence. Primary human nasal fibroblasts were treated with IL-19, then the activation of Smad2/3, NF-κB and relevant pathways, and the expression of FN and Col I were measured.

RESULTS

Expression levels of vimentin, FN, and Col I were significantly increased in nasal tissues from patients with CRSsNP compared with CRSwNP and control subjects. Moreover, IL-19 co-localized with FN and Col Ι in nasal tissues. IL-19-treated fibroblasts had increased production of FN and Col I, which was associated with the activated Smad2/3 and NF-κB pathways. Moreover, Smad2/3 activation was mediated by the NF-κB pathway in IL-19-treated fibroblasts.

CONCLUSIONS

IL-19 promotes FN and Col I production via the activated NF-κB-Smad2/3 pathway in fibroblasts, leading to fibrosis and collagen deposition in patients with CRS.

Antifibrosis Efficacy of Apo-9-Fucoxanthinone-Contained Sargassum horneri Ethanol Extract on Nasal Polyp: An In Vitro and Ex Vivo Organ Culture Assay

Sargassum horneri is a seaweed species with diverse bioactivities. However, its antifibrotic effects during nasal polyp (NP) formation are not clearly understood. Therefore, we investigated the inhibitory effect of S. horneri on fibrosis progression in NP-derived fibroblasts (NPDFs) and NP tissues ex vivo. NPDFs were stimulated with TGF-β1 in the presence or absence of S. horneri ethanol extract (SHE). The extracellular matrix (ECM) protein production levels, myofibroblast differentiation (α-smooth muscle actin, α-SMA), and phosphorylation of Smad 2/3 and -ERK in TGF-β1-stimulated NPDFs were investigated using western blotting. Further, the contractile activity of SHE was assessed by performing a collagen gel contraction assay. The expression levels of collagen-1, fibronectin, and α-SMA were investigated in NP organ cultures treated with SHE. TGF-β1 stimulated ECM protein expression, myofibroblast differentiation, and collagen contractile activity while these were attenuated by pretreatment with SHE. We also found antifibrotic effect of SHE on ex vivo NP tissues. The antifibrotic effects of SHE were modulated through the attenuation of Smad 2/3 and ERK signaling pathways in TGF-β1-stimulated NPDFs. In conclusion, SHE inhibited ECM protein accumulation and myofibroblast differentiation during NP remodeling. Thus, SHE may be helpful as a treatment for NP recurrence after endoscopic sinus surgery.

Transcription Factor Specificity Protein 1 Regulates Inflammation and Fibrin Deposition in Nasal Polyps Via the Regulation of microRNA-125b and the Wnt/β-catenin Signaling Pathway

Nasal polyps (NPs) are multifactorial soft growths inside the nasal passages and are associated with chronic inflammation that originate from the nasal and paranasal sinus mucosae. This study focused on the role of microRNA (miR)-125b and the molecules associated with NP development. Differentially expressed miRNAs between nasal tissues from patients with chronic rhinosinusitis (CRS) with NP (CRSwNP) and CRS without NP (CRSsNP) were screened using microarray analysis. A murine model of CRSwNP was established. The expression of miR-125b in murine tissues was examined using reverse transcription quantitative polymerase chain reaction. Candidate upstream regulators of miR-125b were predicted using bioinformatics tools, and the binding relationship between specificity protein 1 (Sp1) and miR-125b was validated using luciferase and chromatin immunoprecipitation assays. Altered expression of Sp1 and miR-125b was induced to evaluate their relevance to the progression of NPs. miR-125b expression was significantly upregulated in NP tissues from patients with CRSwNP. Sp1 was confirmed as an upstream regulator that promotes miR-125b transcription in NPs. Overexpression of Sp1 reduced levels of d-dimer (an indicator of fibrinogen degradation products) and tissue-type plasminogen activator (t-PA) but increased eosinophil cationic protein and peroxidase levels, as well as the levels of inflammatory factors interleukin-5 (IL-5) and IL-8 in murine NP tissues. However, these trends were reversed after miR-125b downregulation. Sp1 and miR-125b were found to activate the Wnt/β-catenin signaling pathway in NPs. This study demonstrated that Sp1, an upstream transcription factor of miR-125b, accumulates on the miR-125b promoter to activate its transcription, which induces inflammation and fibrin deposition in NP by activating the Wnt/β-catenin axis.

Type 2 immunity-driven diseases: Towards a multidisciplinary approach

Asthma, atopic dermatitis and chronic rhinoconjunctivitis are highly heterogeneous. However, epidemiologic associations exist between phenotypic groups of patients. Atopic march is one such association but is not the only common point. Indeed, beyond such phenotypes, hallmarks of type 2 immunity have been found in these diseases involving immune dysregulation as well as environmental triggers and epithelial dysfunction. From the canonical Th2 cytokines (IL-4, IL-5, IL-13), new cellular and molecular actors arise, from the epithelium's alarmins to new innate immune cells. Their interactions are now better understood across the different environmental barriers, and slight differences appeared. In parallel, the development of type 2-targeting biotherapies not only raised hope to treat those diseases but also raised new questions regarding their true pathophysiological involvement. Here, we review the place of type 2 immunity in the different phenotypes of asthma, chronic rhinitis, chronic rhinosinusitis and atopic dermatitis, highlighting nuances between them. New hypotheses rising from the use of biotherapies will be discussed along with the uncertainties and unmet needs of this field.

Anterior part middle turbinoplasty in endoscopic sinus surgery: a randomized controlled study

OBJECTIVE

Resection of middle turbinate in the setting of endoscopic sinus surgery is a controversial procedure. Our aim is to assess the impact of the anterior part middle turbinoplasty on the outcome of endoscopic sinus surgery, incidence of synechia between the middle turbinate and the lateral nasal wall, intra- and post-operative accessibility to the paranasal sinuses.

METHODS

Single blinded randomized controlled study of 120 patients with chronic rhinosinusitis without polyps, they were allocated into two groups, we performed anterior part middle turbinoplasty in the group one "60 patients", and we preserved the middle turbinate in the group two "60 patients". We assessed the patients pre-operatively by Sino-nasal outcome Test (SNOT-22), intra-operatively by Likert scale score for the sinuses accessibility. At least 6 months post-operatively, we assessed the patients by SNOT-22, and Likert scale score for sinus accessibility.

RESULTS

During and after surgery, the Likert scale score in the group one showed statistically significant better sinuses accessibility than in the group two. We noticed synechia between the MT and the lateral nasal wall in 9.2% and 18.2% of the operated sides in group one and group two, respectively. SNOT-22 and its smell item improved significantly in both groups with no statistically significant differences between them. No major complications were reported.

CONCLUSION

Anterior part middle turbinoplasty is a safe and effective technique during endoscopic sinus surgery to improve the intra- and post-operative sinus accessibility, and decrease the incidence of post-operative synechia, with no adverse effect on olfaction or bleeding.

Alteration of Histopathology in Recurrent Nasal Polyps

OBJECTIVE

The objective of this study was to analyze the histopathologic changes in recurrent nasal polyps (NPs) in terms of tissue inflammatory cells infiltration and mucosal remodeling.

METHODS

Thirty-five patients with primary NPs requiring a revision surgery during follow-up and a matched control group of 35 primary NP patients without recurrence were retrospectively enrolled. Histopathologic examination was performed of tissue inflammatory cells, subepithelial edema, epithelial cell hyperplasia, basement membrane thickness, and fibrosis.

RESULTS

The mean eosinophil and neutrophil counts, proportions of eosinophil and neutrophil, as well as total inflammatory cell count were significantly higher in the recurrent group than those in the controls. Higher subepithelial edema was seen in the recurrent group. Within the recurrent group, the mean tissue eosinophil count and relative eosinophilia reduced from the first operation to revision surgery, whereas neutrophil count and proportion, and total inflammatory cell counts remained unchanged. Subepithelial edema and epithelial cell hyperplasia were significantly reduced after the first surgical procedure.

CONCLUSION

NP recurrence is associated with higher inflammatory grade (especially in eosinophilia and neutrophilia). Surgical and corticoid treatments may have an impact on mucosal histopathologic changes but need further certification.

Distinct Patterns of Tissue Remodeling and Their Prognostic Role in Chronic Rhinosinusitis

INTRODUCTION

Tissue remodeling refers to structural changes that occur in damaged tissue and is associated with disease severity in asthma. However, the characteristics of tissue remodeling and its prognostic role in chronic rhinosinusitis (CRS) remain unclear. In this report, we evaluated the clinical implications of tissue remodeling in CRS.

METHODS

We performed a retrospective cohort study of adult patients who underwent endoscopic sinus surgery for bilateral CRS. The histopathology of sinus mucosa was determined by evaluating the inflammatory cell count and tissue remodeling markers (squamous metaplasia, subepithelial gland proliferation, basement membrane [BM] thickening, stromal edema, and fibrosis). Eosinophilic CRS (ECRS) was defined as an eosinophil count >15/high-power field in the biopsied tissue. Patient characteristics, allergy test grade, preoperative Lund-Mackay score (LMS), and pre- and postoperative Lund-Kennedy scores (LKSs) were analyzed.

RESULTS

Of the identified patients, 59.1% were classified as ECRS and the remaining 40.9% as non-ECRS. Regarding tissue remodeling markers, stromal edema was seen in 90.9%, BM thickening in 63.6%, and stromal fibrosis in 34.1% of patients. In cases with stromal edema and BM thickening, greater tissue eosinophilia was observed, while stromal fibrosis decreased tissue eosinophilia (p < 0.05). Prognostically, subepithelial gland proliferation alone was an independent risk factor for poor postoperative endoscopic findings (odds ratio: 8.250, 95% confidence interval: 1.128-60.319, p = 0.038).

CONCLUSIONS

Tissue eosinophilia was commonly associated with BM thickening and stromal edema. Subepithelial gland proliferation predicted a poor surgical prognosis in CRS. These findings imply that tissue remodeling provides additional information not only on the CRS endotype but also on the postsurgical prognosis.

Third window approach assisted middle meatal antrostomy: prospective cohort study of the two ports technique in management of hard to reach maxillary sinus pathology

OBJECTIVE

This study aimed to assess the outcomes of a prelacrimal recess approach assisted middle meatal antrostomy in the management of hard to reach maxillary sinus pathologies.

METHOD

Twenty-five patients with maxillary sinus pathology underwent prelacrimal recess approach assisted middle meatal antrostomy (with a prelacrimal recess width of more than 3 mm). Patients were prospectively evaluated using both the Arabic version of the Sino-Nasal Outcome Test-22 and nasal endoscopy at least 6 months post-operatively.

RESULTS

Our study included 25 maxillary sinuses (13 with antrochoanal polyps, 10 with maxillary fungal ball and 2 with a migrated part of a tooth). At a mean follow-up period of 10.9 months, all patients showed significant improvement in total mean Sino-Nasal Outcome Test-22 score. There was recurrence of one case with antrochoanal polyp and two cases with asymptomatic synechia. Injury to the nasolacrimal duct was not reported.

CONCLUSION

A prelacrimal recess approach assisted middle meatal antrostomy is a reliable and safe technique to manage pathologies in hard to reach regions within the maxillary sinus.

Histopathologic analysis in chronic rhinosinusitis: Impact on quality of life outcomes

OBJECTIVE

This study investigates the impact of histopathologic parameters on quality of life outcomes in patients with chronic rhinosinusitis.

SETTING

Hospital of Zhejiang University.

STUDY DESIGN

Retrospective analysis of collected data.

SUBJECTS AND METHODS

One hundred and twenty patients with chronic rhinosinusitis (CRS) who underwent endoscopic sinus surgery were recruited. Clinical features, CT evaluation, pre and postoperative SNOT-22 scores and histopathologic findings were collected. Tissue eosinophils and mucosal remodeling were analyzed relative to clinical features and outcomes 12 months postoperatively.

RESULTS

Symptom improvement was seen for the entire population. Eosinophilic CRS had significantly worse preoperative and postoperative SNOT-22 scores than non- eosinophilic CRS. Symptom improvement in eosinophilic CRS after surgery was less than that of non-eosinophilic CRS. There was no significant association between preoperative and postoperative SNOT-22 scores and remodeling markers. However, patients with basement membrane thickening showed less reductions of SNOT-22 score postoperatively.

CONCLUSIONS

Presence of mucosal eosinophilia and basal membrane thickening appear to be the main factors adversely affect the symptom control of surgical intervention. Routine histopathology analysis can provide meaningful information for prognostication of surgical outcome.

Investigating the correlation between mucus cytokine levels, inflammatory cell counts, and baseline quality-of-life measures in chronic rhinosinusitis

BACKGROUND

It is hypothesized that uncontrolled inflammation is responsible for many of the manifestations and symptoms of chronic rhinosinusitis (CRS). Although earlier work has demonstrated an association between olfactory loss and mucus cytokines, the impact on other symptoms is unknown. In this study we investigated the relationship between cytokines, inflammatory cell counts, and patient-reported outcomes measures to better understand how the inflammatory microenvironment correlates with CRS symptomatology.

METHODS

The 22-item Sino-Nasal Outcome Test (SNOT-22) and 8-item Short Form Health Survey (SF-8) were administered to 76 patients undergoing endoscopic sinus surgery for CRS. Mucus was collected intraoperatively from the middle meatus and tested for 17 cytokines using a multiplex flow cytometric bead assay. Eosinophil/neutrophil counts were obtained from histopathologic slide review. Spearman correlations between cytokines, cell counts, and quality-of-life subdomain scores were assessed without multiple comparisons correction due to the small sample size.

RESULTS

Interleukin-4 (IL-4) correlated significantly with the Rhinologic domain (R_s = 0.25, p = 0.03), whereas eosinophil and neutrophil counts were inversely correlated with the Extranasal Rhinologic domain (R_s = -0.32, p = 0.01; and R_s = -0.27, p = 0.03). Subgroup analysis for nasal polyposis (CRSwNP) showed significant correlations between IL-6 and Total SF-8 (R_s = 0.35, p = 0.02), General Health (R_s = 0.34, p = 0.03), and Emotional (R_s = 0.47, p = 0.002) scores. In patients without polyps (CRSsNP), IL-21 correlated positively with Extranasal Rhinologic Symptoms domain (R_s = 0.41, p = 0.01).

CONCLUSION

This pilot study identifies possible pairwise correlations between mucus cytokine levels and baseline quality-of-life measures that need confirmation in larger, targeted studies. Due to the exploratory methodology, positive results may be spurious and should only be used as a starting point for future confirmatory work.

Differential effects of postoperative oral corticosteroid on eosinophilic vs. non-eosinophilic CRSwNP subtypes

PURPOSE

The efficacy of postoperative oral corticosteroids on surgical outcomes in chronic rhinosinusitis with nasal polyps (CRSwNP) patients following endoscopic sinus surgery (ESS) remains controversial. This study evaluated the potential benefits of postoperative oral corticosteroids on surgical outcomes in CRSwNP patients and investigated the differential effects on eosinophilic CRSwNP (ECRSwNP) and noneosinophilic CRSwNP (NECRSwNP).

MATERIALS AND METHODS

Patients with bilateral CRSwNP who underwent ESS were enrolled and randomized to receive either oral prednisolone (30 mg/day) or placebo for 2 weeks after surgery. Visual analog scale (VAS) and Sino-Nasal Outcome Test 22 (SNOT-22) scores were chosen as the subjective outcomes, evaluated at preoperative baseline and 1, 3, and 6 months postoperatively. Lund-Kennedy Endoscopic Scores (LKESs) were used as the objective outcome, evaluated at preoperative baseline and at 2 weeks and 2, 3, and 6 months postoperatively.

RESULTS

In total, 100 patients with bilateral CRSwNP were enrolled, of whom only 82 completed the 6-month follow-up. The subjective outcomes showed no significant difference at each follow-up points. Of the objective outcomes, the corticosteroid group reporting a trend of improvement in LKESs at 6 months postoperatively (p = 0.05). After stratification by tissue eosinophils, only patients with NECRSwNP (<10 eosinophils/HPF) demonstrated a significant improvement in LKESs at 3 months postoperatively (p = 0.03).

CONCLUSIONS

Postoperative oral corticosteroids did not provide additional improvements in VAS and SNOT-22 scores; nevertheless, a trend of LKES improvement was noted at 6 months postoperatively. After stratification by tissue eosinophils, this effect was significant only among NECRSwNP patients at 3 months follow-up.

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.

Fucoxanthin Inhibits Myofibroblast Differentiation and Extracellular Matrix Production in Nasal Polyp-Derived Fibroblasts via Modulation of Smad-Dependent and Smad-Independent Signaling Pathways

Nasal polyps (NPs) are a multifactorial disorder associated with a chronic inflammatory state of the nasal mucosa. Fucoxanthin (Fx) is a characteristic orange carotenoid obtained from brown algae and has diverse immunological properties. The present study investigated whether Fx inhibits fibrosis-related effects in nasal polyp-derived fibroblasts (NPDFs) and elucidated the molecular signaling pathways involved. The production of collagen type I (Col-1) was investigated in NP tissue via immunohistochemistry and western blot analysis. NPDFs were treated with transforming growth factor (TGF)-β1 (1 ng/mL) in the presence or absence of Fx (5⁻30 µM). The levels of α-smooth muscle actin (α-SMA), Col-1, and phosphorylated (p)-Smad 2/3, signal protein-1 (SP-1), MAPKs (mitogen-activated protein kinases), and Akt were measured by western blot analysis. The expression of Col-1 was detected in NP tissues. TGF-β1 stimulated the production of α-SMA and Col-1, and stimulated the contraction of collagen gel. However, pretreatment with Fx attenuated these effects. Furthermore, these inhibitory effects were mediated through modulation of both Smad 2/3 and Akt/SP-1 signaling pathways in TGF-β1-induced NPDFs. The results from the present study suggest that Fx may be a novel anti-fibrotic agent for the treatment of NP formation.

Role of tissue eosinophils in chronic rhinosinusitis-associated olfactory loss

BACKGROUND

Olfactory dysfunction is 1 of the hallmark symptoms of chronic rhinosinusitis (CRS). Eosinophilic inflammation has been implicated as a potential causative factor. However, prior studies have been limited by retrospective study designs, concomitant use of systemic corticosteroids, and other confounding factors.

METHODS

CRS and healthy non-CRS control subjects undergoing endoscopic sinus or skull-base surgery were prospectively enrolled and completed olfactory testing utilizing the 40-item Smell Identification Test (SIT) immediately prior to surgery. Histopathological evaluation of tissue excised from the ethmoid bulla was performed by a pathologist in a blinded fashion. Disease severity and patient-reported outcomes were measured via the Lund-Mackay computed tomography (CT) grading system and 22-item Sino-Nasal Outcome Test (SNOT-22), respectively. The associations between olfactory function, tissue eosinophilia, and disease severity were analyzed using Spearman rank order correlation and multiple linear regression.

RESULTS

Twenty-seven (27) subjects with CRS without nasal polyps (CRSsNP), 32 subjects with CRS with nasal polyps (CRSwNP), and 10 healthy non-CRS controls were enrolled. CRSwNP was associated with higher mean tissue eosinophil counts (71.6 vs 28.1 eosinophils/high-power field [HPF], p < 0.05) and lower age/sex-adjusted SIT scores (-17.4 vs -6.2, p < 0.001) when compared to CRSsNP. SIT scores were strongly negatively correlated with tissue eosinophil counts in CRSwNP (r = -0.60, p = 0.0003), but not CRSsNP (r = 0.16, p = 0.42). The correlation between olfactory function and tissue eosinophilia in CRSwNP persisted after adjusting for disease severity.

CONCLUSION

Tissue eosinophilia is associated with olfactory loss in CRSwNP, independent of disease severity. These results suggest a possible role for eosinophils or eosinophil-associated cytokines in CRS-associated olfactory loss.

Clinical implications of mucosal remodeling from chronic rhinosinusitis

BACKGROUND

Prognostic implications of mucosal remodeling in chronic rhinosinusitis (CRS) remain unclear. Remodeling of respiratory mucosa in asthma is associated with greater medication use and decreased function. This study investigates the implications of mucosal remodeling on long-term clinical outcomes in patients with CRS.

METHODS

A case-control study of adult patients with CRS undergoing endoscopic sinus surgery (ESS) was performed. Mucosal remodeling was defined by squamous metaplasia, subepithelial fibrosis, and/or basement membrane thickening. The presence of remodeling changes were assessed relative to clinical and treatment outcomes at a minimum of 12 months postoperatively. Clinical outcomes were assessed at baseline and 12 months using a Nasal Symptom Score (NSS) and 22-item Sino-Nasal Outcome Test (SNOT-22). Treatment outcomes were assessed by oral corticosteroid usage (burst/continuous), topical corticosteroid irrigation frequency, and further surgical intervention.

RESULTS

A total of 110 patients (48.73 ± 14.75 years, 48.2% female) were assessed. Significant improvements where seen for the entire population, in both NSS (2.64 ± 1.06 to 1.34 ± 1.08, p < 0.001) and SNOT-22 (2.05 ± 0.96 to 1.06 ± 0.79, p < 0.001). Patients with remodeling (n = 88) were younger (47.2 ± 14.8 vs 54.7 ± 13.5 years, p = 0.03), but had similar symptom scores. Remodeling was seen in CRS with nasal polyposis (CRSwNP) (54.5%) and eosinophilic chronic rhinosinusitis (eCRS) (59.8%). Symptom improvement at 12 months was similar between remodeled and non-remodeled groups (NSS: Δ1.34 ± 1.20 vs Δ1.12 ± 1.31, p = 0.395; SNOT-22: Δ1.05 ± 0.91 vs Δ0.73 ± 0.95, p = 0.124); however, patients with remodeling had greater corticosteroid irrigation frequency (64.0% vs 31.6% daily use, Kendall's tau-b p = 0.004).

CONCLUSION

Established mucosal remodeling predicts a greater reliance on topical therapies to reach similar clinical endpoints as those without remodeling.

Comprehensive review on endonasal endoscopic sinus surgery

Endonasal endoscopic sinus surgery is the standard procedure for surgery of most paranasal sinus diseases. Appropriate frame conditions provided, the respective procedures are safe and successful. These prerequisites encompass appropriate technical equipment, anatomical oriented surgical technique, proper patient selection, and individually adapted extent of surgery. The range of endonasal sinus operations has dramatically increased during the last 20 years and reaches from partial uncinectomy to pansinus surgery with extended surgery of the frontal (Draf type III), maxillary (grade 3-4, medial maxillectomy, prelacrimal approach) and sphenoid sinus. In addition there are operations outside and beyond the paranasal sinuses. The development of surgical technique is still constantly evolving. This article gives a comprehensive review on the most recent state of the art in endoscopic sinus surgery according to the literature with the following aspects: principles and fundamentals, surgical techniques, indications, outcome, postoperative care, nasal packing and stents, technical equipment.

Clinical and biological markers of difficult-to-treat severe chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease of the upper airways of which two major phenotypes exist, CRS without nasal polyps (CRSsNP) and CRS with nasal polyps (CRSwNP). Some patients with CRS have suboptimal response to current guideline treatments. These patients remain severe and uncontrolled by treatment and have a poor quality of life. It is highly important to identify both clinical and biological markers, so-called biomarkers, in this subset of patients. The presence of nasal polyps and comorbidity with asthma and with aspirin-exacerbated respiratory disease (AERD) are the most common clinical traits that have been associated to difficult-to-treat severe CRS. In addition to clinical traits, numerous biological markers, with known etiopathogenic roles in CRS, have been associated to difficult-to-treat or recalcitrant CRS. This review summarizes the existing knowledge of the clinical and biological markers associated to difficult-to-treat or uncontrolled severe CRS.

Topical cathelicidin (LL-37) an innate immune peptide induces acute olfactory epithelium inflammation in a mouse model

BACKGROUND

Cathelicidin (LL-37) is an endogenous innate immune peptide that is elevated in patients with chronic rhinosinusitis (CRS). The role of LL-37 in olfactory epithelium (OE) inflammation remains unknown. We hypothesized that: (1) LL-37 topically delivered would elicit profound OE inflammation; and (2) LL-37 induced inflammation is associated with increased infiltration of neutrophils and mast cells.

METHODS

To test our hypothesis we challenged C57BL/6 mice intranasally with increasing concentrations of LL-37. At 24 hours tissues were examined histologically and scored for inflammatory cell infiltrate, edema, and secretory hyperplasia. In separate experiments, fluorescently conjugated LL-37 was instilled and tissues were examined at 0.5 and 24 hours. To test our last hypothesis, we performed tissue myeloperoxidase (MPO) assays for neutrophil activity and immunohistochemistry for tryptase to determine the mean number of mast cells per mm(2) .

RESULTS

LL-37 caused increased inflammatory cell infiltrate, edema, and secretory cell hyperplasia of the sinonasal mucosa, with higher LL-37 concentrations yielding significantly more inflammatory changes (p < 0.01). Fluorescent LL-37 demonstrated global sinonasal epithelial binding and tissue distribution. Further, higher concentrations of LL-37 led to significantly greater MPO levels with dose-dependent increases in mast cell infiltration (p < 0.01).

CONCLUSION

LL-37 has dramatic inflammatory effects in the OE mucosa that is dose-dependent. The observed inflammatory changes in the olfactory mucosa were associated with the infiltration of both neutrophils and mast cells. Our biologic model represents a new model to further investigate the role of LL-37 in OE inflammation.

Endoscopic Management of Chronic Frontal Sinusitis: Prospective Quality of Life Analysis

BACKGROUND

Previous studies of endoscopic frontal sinus surgery have been primarily retrospective and focused on symptom relief only.

OBJECTIVES

To prospectively assess the impact of endoscopic frontal sinus surgery on frontal sinus ostium patency and disease-specific quality of life as measured by the Rhinosinusitis Disability Index (RSDI).

STUDY DESIGN

A 60-patient cohort with chronic frontal sinusitis (100 diseased frontal sinuses) was prospectively evaluated using the RSDI, computed tomography (CT) imaging, and endoscopic examination. Image-guided endoscopic frontal sinusotomy (Draf 2a) was performed in each case. Patients were assessed with RSDI and endoscopic assessment at least 6 months postoperatively.

RESULTS

At a mean follow-up of 10 months, endoscopic assessment revealed patent frontal recesses in 90 of 100 frontal sinuses (90%), with significant improvement in the total RSDI score (41.98 ± 26.48 preoperatively to 17.15 ± 15.66 postoperatively) as well as each of its physical, emotional, and functional subscales from 16.3 ± 9.03, 12.23 ± 10.55, 13.45 ± 9.59 preoperatively to 5.95 ± 5.71, 5.55 ± 5.66, 5.65 ± 5.72 postoperatively, respectively. Similar improvement was seen in patients with asthma, polyps, and those undergoing revision sinus surgeries.

CONCLUSIONS

With frontal recess mucosal preservation and meticulous postoperative endoscopic surveillance, endoscopic frontal sinusotomy results in high rates of frontal sinus ostium patency with significant improvement in quality of life.