Chronic rhinosinusitis in Asia

Predictors of nasal bacterial culture rates in patients with chronic rhinosinusitis

All nontechnical factors were analyzed to predict nasal bacterial culture results in patients with chronic rhinosinusitis (CRS). Four hundred and ninety-six CRS patients, who underwent functional endoscopic sinus surgery (FESS), were enrolled. Prior to FESS, the severity of each patient's CRS was evaluated using a questionnaire, endoscopic examination, acoustic rhinometry, smell test, saccharine transit test, and CT scan. Nasal bacterial cultures were collected from both middle meati using a cotton-tipped stick. Our results showed that the symptom severity complained of by patients and their loss of smell function did not influence the bacterial culture rate. We discovered that the bacterial culture rate was significantly higher in nostrils with nasal polyps than those without polyps, along with nostrils experiencing thick, purulent discharge as opposed to those without discharge. Additionally, this result also occurred in nostrils with a saccharin transit time of more than 30 min than it did in those with a saccharin transit time of less than or equal to 30 min. Both the total endoscopic score and anterior group CT score were significantly higher in nostrils with positive culture than those with negative culture, while the second minimal cross-sectional area (MCA₂) of the nasal cavity was significantly lower in nostrils with positive culture than those with negative culture. Multiple logistic regression analysis showed that both nasal polyps and MCA₂ were the predictors for positive nasal bacterial culture results. It was concluded that nasal polyps and MCA₂ were the predictors for positive nasal bacterial culture results in CRS patients.

Whole-transcriptome sequencing reveals heightened inflammation and defective host defence responses in chronic rhinosinusitis with nasal polyps

INTRODUCTION

The pathways underlying chronic rhinosinusitis with nasal polyps (CRSwNP) are unclear. We conducted genome-wide gene expression analysis to determine pathways and candidate gene sets associated with CRSwNP.

METHODS

We performed whole-transcriptome RNA sequencing on 42 polyp (CRSwNP-NP) and 33 paired nonpolyp inferior turbinate (CRSwNP-IT) tissues from patients with CRSwNP and 28 inferior turbinate samples from non-CRS controls (CS-IT). We analysed the differentially expressed genes (DEGs) and the gene sets that were enriched in functional pathways.

RESULTS

Principal component-informed analysis revealed cilium function and immune regulation as the two main Gene Ontology (GO) categories differentiating CRSwNP patients from controls. We detected 6182 and 1592 DEGs between CRSwNP-NP versus CS-IT and between CRSwNP-NP versus CRSwNP-IT tissues, respectively. Atopy status did not have a major impact on gene expression in various tissues. GO analysis on these DEGs implicated extracellular matrix (ECM) disassembly, O-glycan processing, angiogenesis and host viral response in CRSwNP pathogenesis. Ingenuity Pathway Analysis identified significant enrichment of type 1 interferon signalling and axonal guidance canonical pathways, angiogenesis, and collagen and fibrotic changes in CRSwNP (CRSwNP-NP and CRSwNP-IT) tissues compared with CS-IT. Finally, gene set enrichment analysis implicated sets of genes co-regulated in processes associated with inflammatory response and aberrant cell differentiation in polyp formation.

CONCLUSIONS

Gene signatures involved in defective host defences (including cilia dysfunction and immune dysregulation), inflammation and abnormal metabolism of ECM are implicated in CRSwNP. Functional validation of these gene expression patterns will open opportunities for CRSwNP therapeutic interventions such as biologics and immunomodulators.

Neutrophils as a Protagonist and Target in Chronic Rhinosinusitis

Neutrophils have traditionally been acknowledged as the first immune cells that are recruited to inflamed tissues during acute inflammation. By contrast, their importance in the context of chronic inflammation has been studied in less depth. Neutrophils can be recruited and are largely present in the nasal mucosa of patients with chronic rhinosinusitis (CRS) both in Asians and in Caucasians. Increased infiltration of neutrophils in patients with CRS has been linked to poor corticosteroid response and disease prognosis. Meanwhile, tissue neutrophils may possess specific phenotypic features distinguishing them from resting blood counterparts and are endowed with particular functions, such as cytokines and chemokines production, thus may contribute to the pathogenesis of CRS. This review aims to summarize our current understanding of the pathophysiologic mechanisms of CRS, with a focus on the roles of neutrophils. We discuss recruitment, function, and regulation of neutrophils in CRS and outline the potential therapeutic strategies targeting neutrophils.

Endotype-driven care pathways in patients with chronic rhinosinusitis

Chronic rhinosinusitis (CRS) has been differentiated clinically into CRS without nasal polyps and CRS with nasal polyps, with both forms subjected to glucocorticosteroid and antibiotic treatments and, if not successful, to nasal and sinus surgery tailored to endoscopic and computed tomographic scan findings. The elaboration of endotypes based on pathomechanisms involving different immune responses offers new possibilities in terms of prediction of prognosis and risks and sophisticated guidance in personalized pharmacotherapy, surgical approaches, and innovative treatment approaches in the CRS field with various biologics. Surgical approaches can vary from classical functional endoscopic sinus surgery to extended and "reboot" approaches, with the idea to completely remove the dysfunctional and inflamed mucosa and replace it with a newly grown healthy mucosa. Biologics in this field are targeting the type 2 cytokines IL-4, IL-5, and IL-13, as well as IgE. Phase I and II study results are promising, and phase III studies are currently being performed. The development of endotype-driven integrated care pathways appreciating these innovations are now needed for the management of CRS.

Nasal polyps and future risk of head and neck cancer: A nationwide population-based cohort study

BACKGROUND

Nasal polyps are a common condition with a significant effect on quality of life. The association between nasal polyps and future risk of head and neck cancer is unknown.

OBJECTIVE

We sought to investigate the relative risk of nasal cavity and paranasal sinus (NCPS) and nasopharyngeal cancers in a nationwide, population-based, longitudinal retrospective cohort of patients with nasal polyps and matched comparators.

METHODS

The 2005-2017 National Health Insurance claims and National Health Screening program databases were used to construct a cohort of patients with nasal polyps and matched comparators in Korea. The relative risk of NCPS and nasopharyngeal cancer in patients with nasal polyps was examined.

RESULTS

The study consisted of 453,892 patients with nasal polyps and 4,583,938 matched comparators. The mean duration of follow-up was 6.2 years (range, 2-13 years). The incidence rate ratios of patients with nasal polyps compared with the comparators was 7.00 (95% CI, 5.28-9.25) for NCPS cancer and 1.78 (95% CI, 1.28-2.42) for nasopharyngeal cancer. Increased risks of these cancers were only evident in older subjects (age ≥50 years). There were trends toward weaker associations of nasal polyps with these cancers in younger subjects with comorbid asthma or allergic rhinitis (<50 years).

CONCLUSION

Although the absolute cancer incidence is very low, the relative risk of NCPS or nasopharyngeal cancers was significantly greater in older patients with nasal polyps. Given the regional and pathologic heterogeneity of nasal polyps, further studies are needed to explore the underlying mechanisms and validate the relationships.

Cross-talk between TH2 and TH17 pathways in patients with chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease with a spectrum of endotypes. T_H2- and T_H17-related cytokines are 2 central regulators involved in the inflammation associated with CRSwNP.

OBJECTIVE

We sought to investigate the interregulation of T_H2 and T_H17 pathways in Chinese patients with CRSwNP.

METHODS

Levels of key T_H2- and T_H17-related factors were measured in homogenates of polyp tissue obtained from patients with CRSwNP. The relationship of these factors and their expression in groups classified according to tissue IL-5 and IL-17 concentrations were analyzed. Cross-regulation of T_H2 and T_H17 cytokines and the effects of dexamethasone treatment were studied in dispersed nasal polyp cells. Associations between T_H2- and T_H17 related factors and comorbid atopic status and asthma, disease recurrence, and edema scores were also explored.

RESULTS

Four CRSwNP groups were classified based on expression or nonexpression of mutually exclusive T_H2- and T_H17-related factors. The T_H2 cytokines IL-4 and IL-13 inhibited expression of T_H17-related factors, whereas the T_H17 cytokines IL-17 and TGF-β1 enhanced expression of T_H2-related factors. Dexamethasone treatment inhibited both the T_H2 and T_H17 pathways. A patient's atopic status was related to their T_H2 immune response. Edema scores were positively correlated with the T_H2 pathway and negatively correlated with the T_H17 pathway.

CONCLUSION

The T_H2 and T_H17 pathways are mutually exclusive and regulate each other, favoring the development of a T_H2 immune response in Chinese patients with CRSwNP.

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.

Endoscopic sinus surgery for pediatric patients: Prognostic factors related to revision surgery

OBJECTIVES

In the past two decades, endoscopic sinus surgery (ESS) has been performed frequently in children with medically recalcitrant chronic rhinosinusitis (CRS). However, surgical success rates vary according to age. The causes of failure and prognostic factors for revision ESS remain unclear. The aims of the present study were to evaluate prognostic factors related to revision surgery after ESS, and to determine the most optimal timing for surgery in the pediatric population.

METHODS

This was a retrospective review in a tertiary medical center. Children who underwent ESS for CRS between 2004 and 2017 were enrolled. Demographics, sinonasal examination findings, previous operation history, laboratory data, comorbidities, and computed tomography (CT) results were collected from medical records. Prognostic factors for revision surgery were analyzed.

RESULTS

A total of 188 pediatric patients were enrolled in this study. Twenty-four patients (12.8%) required revision surgery. Multivariate logistic regression analysis identified patients with nasal allergy (OR = 6.258; P = .010) and higher Lund-Mackay score on preoperative sinus CT (OR = 1.658; P = .043) had worse outcomes, while older age was a positive prognostic factor (OR = 0.702; P = .018). A cut-off point of 15.68 years of age and mean Lund-Mackay score of 10.5 showed the best predictive power for revision surgery.

CONCLUSION

Because ESS is performed with increasing frequency in children, knowledge of prognostic factors for revision surgery is important. In this study, patients with younger age, nasal allergy, and higher Lund-Mackay score on preoperative sinus CT had worse outcomes.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:1051-1055, 2020.

Association of Inflammation Mediator in Mucosal and Tissue of Chronic Rhinosinusitis with Recurrent Nasal Polyp

BACKGROUND

Chronic rhinosinusitis with polyps (CRSwNP) have a high risk of recurrence and patients often experience repeated surgery. There are several types of inflammatory patterns in CRSwNP, such as Th2 inflammation (eosinophilic) and Th1/Th17 inflammation (neutrophilic).

AIM

This study aims to determine the expression of IL-5, IL-8, IL-17A and TGF-β in recurrent CRSwNP using the most convenient and non-invasive examination tool such as brushing the mucosal polyp and find out its correlation with polyp tissues.

MATERIAL AND METHODS

A cross-sectional comparative study was carried out on 15 samples of mucosal brushing and polyp tissue. Expressions of IL-5, IL-8, IL-17A and TGF-β on mucosa were measured using the Enzyme-Linked Immunosorbent Assay (ELISA) examination and tissues using Immunohistochemical (IHC) examination.

RESULT

The result showed that Only IL-5 has a significant relationship between mucosa and tissue with moderate positive correlation (p < 0.05; r = 0.527).

CONCLUSION

This study concluded that mucosa brushing could be used as a simple and non-invasive examination to observe the expression of IL-5 in recurrent CRSwNP. IL-5 is one of the cytokines that mark the Th2 (eosinophilic) inflammatory pattern where eosinophilic polyps are closely related to recurrence.

Eosinophil extracellular trap formation is closely associated with disease severity in chronic rhinosinusitis regardless of nasal polyp status

Chronic rhinosinusitis (CRS) is a heterogeneous inflammatory airway disease involving non-eosinophilic and eosinophilic phenotypes, which translate to various endotypes. Activated eosinophils and neutrophils are known to generate extracellular traps consisting of DNA and cytotoxic granule proteins. We sought to investigate the presence of eosinophil and neutrophil extracellular traps (EETs and NETs, respectively) in human CRS tissues and to clarify the associations with their clinical features. Nasal polyp (NP) or ethmoid tissue slides of 43 subjects from endoscopic sinus surgery for CRS were analysed. Quantitative analysis of EETs and NETs was performed by confocal microscopy using immunofluorescent staining. For correlation study, the presence of NPs, number of infiltrating tissue eosinophils, preoperative Lund–Mackay scores, and other comorbidities were analysed. EET formation was observed to varying degrees in all CRS groups and was correlated with the number of tissue eosinophils (r  =  0.83, p  < 0.001) regardless of the presence of NPs. Patients with more EETs demonstrated higher Lund–Mackay scores (r  =  0.51, p  = 0.009), blood eosinophilia (r  =  0.80, p  < 0.001), and decreased olfactory function (r  = −0.65, p  < 0.001). No correlation between the extent of EET formation and the presence of atopy or asthma was apparent. However, none of the CRS groups containing neutrophils formed NETs in this study. Eosinophilic CRS indicates the presence of EETs. Formation of EETs could have a role in clinical decision-making and prediction of treatment outcome of CRS, regardless of NP status.

Epithelial physical barrier defects in chronic rhinosinusitis

INTRODUCTION

Chronic rhinosinusitis (CRS) is a common upper airway disease with a prevalence of greater than 10% of the general population. Although the pathogenesis of CRS remains poorly understood, there is growing evidence indicating that epithelial physical barrier defects play an important role in CRS pathogenesis. Areas covered: Epithelial physical barriers are maintained by various intercellular junctions, especially tight junctions (TJs). Recent studies suggest that the expression of TJ molecules and epithelial barrier function in human nasal epithelium are modulated by various internal and external factors. This review summarizes recent advances regarding the structure, function, and regulating mechanisms of the epithelial physical barrier in the context of CRS. Expert opinion: Available data indicate that epithelial physical barrier defects in CRS can result from inhaled allergens, microbial or virus infections, cytokines, hypoxia, or zinc deficiency, among other causes. Several genes/molecules, such as SPINK5, S100A7, S100A8/9, PCDH1, NDRG1, SPRR, and p63 are involved in modulating the physical barrier function in the context of CRS. The exact mechanisms and molecular pathways that lead to these barrier defects, however, require additional study. Additional work is necessary to further explore the epithelial physical barrier function in normal and pathologic sinonasal mucosa.

Precision medicine and phenotypes, endotypes, genotypes, regiotypes, and theratypes of allergic diseases

A rapidly developing paradigm for modern health care is a proactive and individualized response to patients' symptoms, combining precision diagnosis and personalized treatment. Precision medicine is becoming an overarching medical discipline that will require a better understanding of biomarkers, phenotypes, endotypes, genotypes, regiotypes, and theratypes of diseases. The 100-year-old personalized allergen-specific management of allergic diseases has particularly contributed to early awareness in precision medicine. Polyomics, big data, and systems biology have demonstrated a profound complexity and dynamic variability in allergic disease between individuals, as well as between regions. Escalating health care costs together with questionable efficacy of the current management of allergic diseases facilitated the emergence of the endotype-driven approach. We describe here a precision medicine approach that stratifies patients based on disease mechanisms to optimize management of allergic diseases.

Regulation of Interaction between the Upper and Lower Airways in United Airway Disease

The concept of united airway disease comprises allergic rhinitis (AR) with asthma, and eosinophilic chronic rhinosinusitis (ECRS) with asthma. It embodies a comprehensive approach to the treatment of upper and lower airway inflammation. The treatment of upper airway inflammation reduces asthma symptoms and decreases the dose of inhaled corticosteroids (ICS) necessary to treat asthma. However, little is known about the mechanisms of interaction between upper and lower airway inflammation. Here we review these mechanisms, focusing on neural modulation and introduce a novel therapeutic approach to united airway disease using a fine-particle ICS. Our understanding of the relationship between the upper and lower airways and its contribution to T helper 2 (Th2)-skewed disease, such as AR and/or ECRS with asthma, has led us to this novel therapeutic strategy for a comprehensive approach to the treatment of upper airway inflammation with asthma.

Vitamin D deficiency are associated with subjective disease severity in Chinese patients with chronic rhinosinusitis with nasal polyps

OBJECTIVE

To evaluate the serum vitamin D level in patients with chronic rhinosinusitis with nasal polyps and its correlation with the disease severity.

SETTING

Hospital of Zhejiang University.

STUDY DESIGN

Retrospective analysis of collected data.

SUBJECTS AND METHODS

Patients with chronic rhinosinusitis with or without nasal polyps who underwent endoscopic sinus surgery were recruited. Demographic information including age, gender, body mass index, smoke history, atopic status and asthma was collected. Disease severity was measured by the Lund-Mackay CT score and Sino-Nasal Outcome Test-22 score. Serum 25-hydroxyvitamin D3 was measured by enzyme-linked immunosorbent assay preoperatively.

RESULTS

Serum 25-hydroxyvitamin D3 levels were significantly lower in patients with nasal polyps (CRSwNP, 38.2 ± 9.1 nmol/L; CRSsNP, 48.94 ± 12.1 nmol/L; control, 54.1 ± 17.1 nmol/L. p < 0.001), and the levels were significantly associated with the preoperative Sino-Nasal Outcome Test-22 score (p = 0.013), but not with the Lund-Mackay score (p = 0.126). Furthermore, serum 25-hydroxyvitamin D3 levels were associated with the subjective improvement six months postoperatively (p < 0.001), CONCLUSION: Serum 25-hydroxyvitamin D3 levels are lower in Chinese CRSwNP patients. These 25-hydroxyvitamin D3 levels are associated with SNOT-22 score. Preoperative 25-hydroxyvitamin D3 level may impact on the symptom improvement after surgery.

Changes in the clinical and histological characteristics of Chinese chronic rhinosinusitis with nasal polyps over 11 years

BACKGROUND

Traditionally, it was believed that chronic rhinosinusitis with nasal polyps (CRSwNP) demonstrated less eosinophilic and more neutrophilic inflammation in China compared to North America and Europe. However, inflammatory patterns may change over time. The study aimed to analyze the changing trends in the clinical and histological characteristics of CRSwNP over time in China.

METHODS

A total of 115 consecutive CRSwNP patients from 2003 to 2005 and 114 consecutive CRSwNP patients from 2014 to 2016 were enrolled in this retrospective study. The clinical and histological data were compared between patients from the 2 time periods.

RESULTS

The percentage of eosinophils in nasal polyp tissue increased, and the percentage of neutrophils and total inflammatory cell count decreased, over 11 years. The proportion of eosinophilic CRSwNP significantly increased from 59.1% to 73.7% over 11 years. The proportion of neutrophils and the total inflammatory cell count in nasal polyps decreased, and the proportion of eosinophilic CRSwNP patients using intranasal corticosteroids 1 month before surgery increased remarkably over 11 years. Moreover, eosinophilic CRSwNP patients had better compliance with intranasal corticosteroid use than non-eosinophilic CRSwNP patients, and patients with comorbid allergic rhinitis and asthma had better compliance with intranasal corticosteroid use than patients without those conditions.

CONCLUSION

Eosinophilic CRSwNP, which was previously a minor subtype in East Asians, has increased remarkably in incidence to become the predominant CRSwNP subtype in Beijing, China, indicating that rhinologists should place greater emphasis on its diagnosis and treatment.

Interleukin-4-induced posttranscriptional gene regulation of CCL26 by the RNA-binding protein HuR in primary human nasal polyp-derived epithelial cells

BACKGROUND

Much attention on the pathophysiology of nasal polyp (NP) has focused on eosinophils. Interleukin (IL)-4 and eotaxin-3 (C-C motif chemokine ligand 26, or CCL26) levels have been reported to be increased in eosinophilic nasal polyps. The aim of this study was to characterize CCL26 posttranscriptional regulation by the RNA-binding protein HuR in primary human nasal polyp-derived epithelial cells (hNPDECs) challenged with IL-4.

METHODS

A prospective, observational study was conducted. Nasal polyp tissues were obtained from eosinophilic (n = 12) and non-eosinophilic (n = 10) NP patients, and inferior turbinate (IT) tissues were taken from control subjects (n = 9) and cultured into hNPDECs. Expression of HuR and CCL26 were measured by immunohistochemistry, Western blot analysis, enzyme-linked immunoassay, and real-time polymerase chain reaction (PCR). The nucleocytoplasmic shuttling of HuR in hNPDECs was detected by immunofluorescence. Posttranscriptional regulation of CCL26 by HuR was tested by ribonucleoprotein immunoprecipitation assay (RIP) and dual-luciferase reporter assay. CCL26 mRNA stabilization was measured by quatititative PCR after treatment with actinomycin D. Student's t test and one-way analysis of variance were used.

RESULTS

Immunohistochemical data show that both HuR and CCL26 were highly expressed in NP tissues, especially eosinophilic NP tissues (p < 0.05). IL-4 stimulation increased CCL26 mRNA stability, and overexpression and knockdown of HuR affected CCL26 expression. Immunofluorescence data indicate that IL-4 altered the subcellular distribution of HuR. The RIP and dual-luciferase reporter assay results supply strong evidence for HuR binding to CCL26.

CONCLUSION

Our results provide strong support for the hypothesis that IL-4-induced expression of CCL26 in hNPDECs relies partly on CCL26 mRNA stabilization mediated by the interaction of HuR with CCL26 3'UTR.

Chronic Rhinosinusitis-Could Phenotyping or Endotyping Aid Therapy?

OBJECTIVES

We reviewed the phenotyping and endotyping of chronic rhinosinusitis (CRS) and treatment options.

METHODS

We searched PubMed, Google, Google Scholar, and the Proquest Central Database of the Kırıkkale University Library.

RESULTS

Phenotypes are observable properties of an organism produced by the environment acting upon the genotype, that is, patients with a particular disorder are subgrouped according to common characteristics. Currently, CRS is usually phenotyped as being with (CRSwNP) or without (CRSsNP) nasal polyps. However, this is not immutable as some individuals progress from nonpolyp to polypoid CRS over time. Phenotypes of CRS are also based on inflammatory patterns, generally CRSwNP is eosinophilic, CRSsNP neutrophilic; but there is a spectrum, rather than a clear-cut division into 2 types. An endotype is a subtype of a condition defined by a distinct functional or pathobiological mechanism. Endotypes of CRS can be (1) nontype Th2, (2) moderate type Th2, and (3) severe type Th2 immune reactions, based on cytokines and mediators such as IL4, 5, 13. CRS endotyping can also include a (1) type 2 cytokine-based approach, (2) eosinophil-mediated approach, (3) immunoglobulin E-based approach, and (4) cysteinyl leukotriene-based approach. Subdivisions of CRSwNP can be made into nonsteroidal anti-inflammatory drug-exacerbated respiratory disease, allergic fungal sinusitis, and eosinophil pauci-granulomatous arteritis by testing. General treatment for all CRS is nasal douching. The place of surgery needs careful reconsideration. Endotype-directed therapies include glucocorticosteroids, antibiotics, aspirin, antifungals, anticytokines, and immunoglobulin replacement. The recognition of united airways and the co-occurrence of CRSwNPs and severe asthma should lead to common endotyping of both upper and lower airways in order to better direct therapy.

CONCLUSION

Endotyping can allow for the identification of groups of patients with CRS with a high likelihood of successful treatment, such as patients with a moderate type 2 immune reaction or those with acquired immune deficiency.

Pathophysiologic mechanisms of chronic rhinosinusitis and their roles in emerging disease endotypes

OBJECTIVE

Chronic rhinosinusitis (CRS) is a heterogeneous disorder with distinct pathophysiologic mechanisms. Based on transcription factor expression and cytokine production patterns in different innate lymphoid cell (ILC) types, in parallel with those of adaptive CD4⁺ T-helper (T_H) cells and CD8⁺ cytotoxic T (Tc) cells, new perspectives on endotypes of patients are emerging for the immune response deviation into type 1 (orchestrated by ILC1s and Tc1, and T_H1 cells), type 2 (characterized by ILC2s and Tc2 and T_H2 cells), and type 3 (mediated by ILC3s and Tc17 and T_H17 cells). In addition, cluster analysis has been applied to endotyping of CRS in recent years, which has provided additional novel insights into CRS pathogenesis. This review assessed pathologic mechanisms of CRS based on type 1, 2, and 3 immune responses and how they inform us to begin to understand CRS endotypes. This review also assessed recent cluster analysis studies of CRS endotypes. The impact of endotype on therapeutic management of CRS also is summarized.

DATA SOURCES

Review of published literature.

STUDY SELECTIONS

Relevant literature concerning CRS endotypes and possible underlying mechanisms was obtained from a PubMed search and summarized.

RESULTS AND CONCLUSION

CRS with and without nasal polyps are composed of distinct endotypes with distinct deviated immune responses, pathogenic mechanisms, and different responses to medical and surgical treatment. An endotype of CRS with prominent type 2 immune responses is the best-studied endotype and generally can benefit from treatment with steroids and specific type 2 disrupting biologics.

Immunological mechanisms underlying chronic rhinosinusitis with nasal polyps

INTRODUCTION

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common and quality-of-life impacting disorder, with an underlying immunological mechanism similar to other conditions such as eosinophilic asthma or atopic eczema. Areas covered: This review article summarizes the most recent evidence on the main immunological mechanisms involved in the pathogenesis and the perpetuation of CRSwNP, with a particular focus on the key role of epithelium-derived inflammation as a consequence of the interaction with the airborne environment. Expert commentary: The increase in knowledge of the immunology of CRSwNP leads to the development of therapeutical strategies based upon the use of biologic agents that, according to a personalized and precision medicine approach, will provide each single patient with the most suitable immunological treatment.

TREM-1 Neutrophil Activation Pathway Is Suppressed in Eosinophilic Nasal Polyps

Background Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by type 2 helper T-cell-skewed immune profiles, but the state of the neutrophil activation signaling pathway in CRSwNP is unknown. The purpose of this study was to examine neutrophil activation pathways in the pathogenesis of CRSwNP. Methods Institutional review board approved the study in which tissue proteomes were compared between control (inferior turbinate) and CRSwNP (nasal polyps) (n = 10/group) using an aptamer-based proteomic array and confirmed by whole transcriptomic analysis. Protein expression was analyzed using Student's t test and Benjamini-Hochberg procedures followed by the application of Ingenuity Pathway, MetaCore, and Genemania bioinformatics analyses. Results All the patients with CRSwNP (n = 10) had eosinophilic nasal polyps. Compared with controls, proteins associated with the triggering receptor expressed on myeloid cells 1 (TREM-1) neutrophil activation signaling pathway such as Calcineurin B, zeta chain-associated protein kinase of 70 kD (ZAP70), 14-3-3 protein theta, 14-3-3 protein zeta/delta, protein kinase C delta type (PKC-D), Interleukin (IL)-17B, IL-17B receptor, IL-23, and IL-1B were significantly decreased in CRSwNP (fold change [FC] = -1.60, P = .003; FC = -1.85, P = .040; FC = -1.26, P < .001; FC = -1.05, P = .008; and FC = -1.31, P = .004; FC = -1.22, P < .001; FC = -1.09, P = .022; FC = -1.25, P < .001; and FC = -1.31, P = .014; respectively). In contrast, tissue eosinophil count ( P < .001) and eosinophil-associated proteins such as C-C motif chemokine 17, periostin, and galectin 10 were all significantly increased in CRSwNP (FC = 1.56, P = .009; FC = 3.95, P < .001; and FC = 2.44, P < .001; respectively). Furthermore, the FC of the studied proteins' expression significantly and positively correlated with FC of their mRNA expression ( P = .001, r = .75). Conclusions TREM-1-associated neutrophilic signaling pathway proteins are significantly suppressed in eosinophilic CRSwNP.