S. aureus and IgE-mediated diseases: pilot or copilot? A narrative review

INTRODUCTION

S. aureus is a major opportunistic pathogen that has been implicated in the pathogenesis of several chronic inflammatory diseases including bronchial asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), chronic spontaneous urticaria (CSU), and atopic dermatitis. S. aureus can induce the production of both polyclonal and specific IgE that can elicit an inflammatory cascade.

AREAS COVERED

The link between the sensitization to S. aureus enterotoxins and the severity of several chronic inflammatory diseases is reviewed in detail, as well as its therapeutic implications.

EXPERT OPINION

An anti-IgE strategy to inhibit S. aureus enterotoxins would be a valid approach to treat several endotypes of severe asthma, CRSwNP and CSU in which IgE against S. aureus enterotoxins should represent, not only a marker of severity of the diseases but also a target of a treatment.

TLR Signals in Epithelial Cells in the Nasal Cavity and Paranasal Sinuses

The respiratory tract is constantly at risk of invasion by microorganisms such as bacteria, viruses, and fungi. In particular, the mucosal epithelium of the nasal cavity and paranasal sinuses is at the very forefront of the battles between the host and the invading pathogens. Recent studies have revealed that the epithelium not only constitutes a physical barrier but also takes an essential role in the activation of the immune system. One of the mechanisms equipped in the epithelium to fight against microorganisms is the Toll-like receptor (TLR) response. TLRs recognize common structural components of microorganisms and activate the innate immune system, resulting in the production of a plethora of cytokines and chemokines in the response against microbes. As the epithelia-derived cytokines are deeply involved in the pathogenesis of inflammatory conditions in the nasal cavity and paranasal sinuses, such as chronic rhinosinusitis (CRS) and allergic rhinitis (AR), the molecules involved in the TLR response may be utilized as therapeutic targets for these diseases. There are several differences in the TLR response between nasal and bronchial epithelial cells, and knowledge of the TLR signals in the upper airway is sparse compared to that in the lower airway. In this review, we provide recent evidence on TLR signaling in the upper airway, focusing on the expression, regulation, and responsiveness of TLRs in human nasal epithelial cells (HNECs). We also discuss how TLRs in the epithelium are involved in the pathogenesis of, and possible therapeutic targeting, for CRS and AR.

Differential expression and role of S100 proteins in chronic rhinosinusitis

PURPOSE OF REVIEW

Immune system modulators have been under investigation to help elucidate the underlying pathophysiologies of chronic rhinosinusitis (CRS). Psoriasin (S100A7) and calgranulins (S100A8, S100A9, and S100A12) are S100 proteins that have been studied for their immune-mediating responses to pathogens within the context of CRS. This review highlights the expression patterns and proposed roles of S100 proteins in CRS with (CRSwNP) and without (CRSsNP) nasal polyps.

RECENT FINDINGS

Elevated levels of S100A7 and S100A12 were measured in the sinonasal tissues of patients with CRSsNP compared with CRSwNP and controls. S100A12 expression in CRSsNP was significantly correlated to disease severity. Contrastingly, increased S100A8, S100A9, and S100A8/A9 levels were demonstrated in the nasal polyp tissues of patients with CRSwNP compared with those in inferior turbinate and uncinate tissues of patients with CRSsNP and controls.

SUMMARY

The reported differential expression patterns and activities of psoriasin and calgranulins suggest that S100 proteins exert unique and concerted roles in mediating immunity in different subtypes of CRS. These studies will enable further investigations focused on understanding the immune-modulating mechanisms of S100 proteins in different inflammatory signaling pathways and disease phenotypes of CRS toward the pursuit of identifying new biomarkers and targets for improved outcomes.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

[Management strategies for chronic rhinosinusitis with nasal polyps in adults]

INTRODUCTION

Chronic rhinosinusitis with nasal polyps (CRSwNP) is one of the categories of chronic rhinosinusitis and is defined by the presence of bilateral polyps. It is frequently associated with other conditions (asthma, atopy, aspirin intolerance), which worsen its prognosis.

STATE OF ART

The pathophysiology of CRSwNP is still poorly understood. The genesis of polyps is thought to be based on an initial epithelial lesion caused by environmental factors in the context of self-maintained chronic local inflammation. Multiple local and general factors can be involved in this inflammation, which is mainly of Th2 type in Europe. Abnormalities of the epithelial barrier and the immune system (eosinophilia, cytokines, T and B lymphocytes), genetic factors and pathogens, including Staphylococcus aureus, have been incriminated. The treatment of CRSwNP is mainly based on the application of local corticosteroids. Surgery remains an important part of patient management where CRSwNP becomes resistant to topical therapy. The management of CRSwNP may be at a turning point thanks to the arrival of biological therapies (anti-IgE, anti-IL-5, anti-IL-4/IL-13) the initial results of which are promising.

PERSPECTIVES/CONCLUSIONS

With the new concept of endotypes, current avenues of research are moving towards a better understanding of the inflammatory mechanisms of CRSwNP. Immunotherapy appears to be a promising future for the treatment of CRSwNP.

Correlation Between HMGB1 and TLR4 Expression in Sinonasal Mucosa in Patients With Chronic Rhinosinusitis

OBJECTIVES

Chronic rhinosinusitis (CRS) is one of the most common inflammations in the upper airway. Despite the wide prevalence of CRS, the pathogenesis of this disease is poorly understood. Several components of the innate immune system may play a significant role in CRS, including Toll-like receptor 4 (TLR4), TLR9, and high-mobility group box 1 protein (HMGB1). This study was conducted to determine the expression of TLR4, TLR9, HMGB1, and pNFκ-B p65 in paraffin-embedded blocks of patients with CRS with nasal polyps compared with those of the control group.

METHODS

Twenty-six formalin-fixed, paraffin-embedded samples from patients with confirmed CRS and 26 patients undergoing septoplasty due to anatomic variations and no other inflammatory nasal diseases as the control group were assessed. Expression patterns of HMGB1, TLR9, TLR4, and pNFκ-B p65 genes were examined using real-time quantitative reverse transcription polymerase chain reaction (Real-Time qRT-PCR). Statistical analyses were performed with SPSS and analyzed using unpaired 2-tailed t tests or 1-way analysis of variance.

RESULTS

Real-time PCR showed that the expression level of HMGB1 messenger RNA was significantly increased in the tissues of patients with CRS compared with controls (P < .05). The other 3 genes were also upregulated in the patients, but were not significant compared with control. Analysis of the Pearson correlation coefficient (r) revealed a significant positive correlation between HMGB1 and TLR4 (r = 0.79, P < .05) in patients and negative correlation between TLR4 and NfκB in the control group (r = 0.94; P < .05).

CONCLUSIONS

Both HMGB1 and TLR4 are increased in the paranasal sinus mucosa of patients with CRS. These results suggest a possible contribution of HMGB1 and its internal receptor (TLR4) in the pathophysiology of CRS.

The impact of nasal airflow on sinus mucosa: A radiographic review

BACKGROUND

Chronic rhinosinusitis (CRS) is a disease of widespread prevalence and high morbidity. Many suggest that the introduction of toxins and allergens via nasal airflow plays a significant role in the development of CRS. In patients who have undergone total laryngectomy, nasal airflow is disrupted, providing an opportunity to examine the role of nasal airflow in sinonasal pathology.

METHODS

All patients who received a total laryngectomy between 2002 and 2012 with preoperative and postoperative computed tomography (CT) scans were retrospectively reviewed. The Lund-Mackay (LM) score for each sinus was recorded for both scans. The assessment of differences in pre-operative and post-operative LM scores was analyzed utilizing paired t-tests.

RESULTS

56 patients underwent total laryngectomy and had both preoperative and postoperative CT scans. There were no significant differences in the LM scores between pre-operative and post-operative scans within each sinus (frontal sinus, p = 1.0; anterior ethmoid sinus, p = 0.77; posterior ethmoid sinus, p = 0.45; maxillary sinus, p = 0.90; sphenoid sinus, p = 0.63; ostiomeatal complex, p = 0.78) or in the total LM scores (p = 0.97). Furthermore, patients with pre-operative sinonasal mucosal thickening (total LM score > 0) showed no significant change in their total LM score post-operatively (p = 0.13).

CONCLUSION

In total laryngectomy patients, studies demonstrate that a disruption in nasal airflow is correlated to altered sinonasal physiology and decreased subjective symptoms. However, our study shows that the disruption of nasal airflow results in no significant change in radiographic evidence of sinonasal mucosal thickening.

C3a receptor antagonism as a novel therapeutic target for chronic rhinosinusitis

Chronic rhinosinusitis with nasal polyps (CRSwNP) is an inflammatory disease with an unknown etiology. Recent studies have implicated the complement system as a potential modulator of disease immunopathology. We performed proteomic pathway enrichment analysis of differentially increased proteins, and found an enrichment of complement cascade pathways in the nasal mucus of individuals with CRSwNP as compared to control subjects. Sinonasal mucus levels of complement 3 (C3) correlated with worse subjective disease severity, whereas no significant difference in systemic C3 levels could be determined in plasma samples. Given that human sinonasal epithelial cells were the predominate sinonasal source of C3 and complement anaphylatoxin 3a (C3a) staining, we focused on their role in in vitro studies. Baseline intracellular C3 levels were higher in CRSwNP cells, and following exposure to Aspergillus fumigatus (Af) extract, they released significantly more C3 and C3a. Inhibition of complement 3a receptor (C3aR) signaling led to a decrease in Af-induced C3 and C3a release, both in vitro and in vivo. Finally, we found in vivo that C3aR deficiency or inhibition significantly reduced inflammation and CRS development in a mouse model of Af-induced CRS. These findings demonstrate that local sinonasal complement activation correlates with subjective disease severity, and that local C3aR antagonism significantly ameliorates Af-induced CRS in a rodent model.

P-glycoprotein and chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a heterogeneous definition that includes different disease states that usually are associated with abnormal inflammatory responses. Besides being prevalent, the mechanisms involved in its pathogenesis are not clear and there are few therapeutic options with tolerable side effects. P-glycoprotein (P-gp) is an efflux pump responsible of extruding xenobiotics and cellular metabolites from multiple cell types. It has been widely studied in the cancer field, due to its ability to confer resistance to chemotherapy. It also promotes Type 2 helper T-cell polarizing cytokine secretion in CRS and may represent a potential target to differentiate subtypes of CRS and personalize treatment. This state-of-the-art review explores current knowledge on the participation of P-gp in the pathogenesis of CRS, the P-gp inhibition as a novel targeted therapeutic strategy and the exosomal P-gp test, a non-invasive biomarker that can represent an important advance in the field of rhinology.

Calgranulin C (S100A12) Is Differentially Expressed in Subtypes of Chronic Rhinosinusitis

Background Calgranulin C (S100A12) is an innate immune peptide at the air-mucosal interface associated with neutrophil involvement, which when overexpressed has been implicated as a biomarker of inflammatory diseases. Decreased epithelial expression of certain innate immune peptides has been reported in chronic rhinosinusitis (CRS). We hypothesized that S100A12 is differentially expressed in the sinonasal mucosa of patients with CRS compared to controls and that S100A12 is a potential biomarker of CRS-specific quality of life (QOL) and disease severity. Methods A prospective observational study was conducted which included 70 patients: 17 controls, 28 having CRS without (CRSsNP), and 25 with (CRSwNP) nasal polyps. The expression of S100A12 and human neutrophil elastase (HNE) was assessed in the anterior ethmoid tissues from all patients using enzyme-linked immunosorbent assay (ELISA) and immunohistochemical (IHC) analyses. Disease-specific QOL (Rhinosinusitis Disability Index) and disease severity (computed tomography [CT] and endoscopy) were evaluated and correlated to the expression levels of S100A12. Results S100A12 and HNE were significantly elevated in patients with CRSsNP compared to normal controls ( P < .05 and P < .001, respectively) and patients with CRSwNP ( P < .05 and P < .001, respectively), as measured by ELISA and IHC analyses. Patients with CRS exhibited worse CRS-specific disease severity compared to normal controls ( P < .05), and the increased protein levels of S100A12 were significantly correlated to disease severity, represented by CT scores ( P < .05). Conclusions S100A12 is differentially expressed in CRS subtypes and is significantly elevated in patients with CRSsNP and associated with CRS-specific disease severity.

Genetic and Immune Dysregulation in Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a prevalent condition that is heterogeneous in disease characteristics and multifactorial in cause. Although sinonasal mucosal inflammation in CRS is often either reversible or well-managed medically and surgically, a significant proportion of patients has a refractory form of CRS despite maximal therapy. Two of the several described factors thought to contribute to disease recalcitrance are genetic influences and dysfunction of the host immune system. Current evidence for a genetic basis of CRS is reviewed, as it pertains to putative abnormalities in innate and adaptive immune function. The role of systemic immunodeficiencies in refractory CRS is discussed.

Refractory Chronic Rhinosinusitis with Nasal Polyposis

Chronic rhinosinusitis with nasal polyposis (CRSwNP) represents a subset of chronic sinusitis with various causes. Some forms of the disease are driven by allergy, often in association with asthma. Refractory CRSwNP can be associated with cystic fibrosis and other clinical syndromes. More recent literature is presented regarding roles of innate immunity and superantigens. Effective treatment of CRSwNP requires careful endoscopic sinus surgery followed by an individualized treatment plan that often includes oral and topical steroids. Recidivism of polyps is common, and patients require long-term follow-up.

Differences in RANTES and IL-6 levels among chronic rhinosinusitis patients with predominant gram-negative and gram-positive infection

Background

Bacteria are suspected players in the pathogenesis of chronic rhinosinusitis (CRS), yet their exact role is not understood. We investigated the effect of planktonic and biofilm of staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) on the mucosa of CRS patients with gram-positive and gram-negative infections by measuring the levels of IL-6 and RANTES, a chemokine with activity on eosinophils and T lymphocytes.

Methods

Ethmoid mucosa of six CRS patients with gram-positive bacteria on culture and five with gram-negative bacteria were compared to ethmoid mucosa of 8 control patients. The tissue explants were stimulated with SA and PA extracts in planktonic and biofilm form for 6 hours, then RANTES levels were measured by ELISA.

Results

Compared to the control group, CRS patients with gram-negative predominance demonstrated a significantly higher level of RANTES expression in response to all forms of bacterial stimuli (P-value <0.05). Patients with gram-positive predominance showed a higher level of RANTES compere to control group, however, this difference was not significant (P-value >0.05).

Conclusions

The mucosa of CRS patients with gram-negative infections has a heightened innate immune response compared to controls and patients with gram-positive infections. It is possible that this response leads to the pathological eosinophilic inflammation seen in CRS.

Electronic supplementary material

The online version of this article (doi:10.1186/s40463-016-0183-x) contains supplementary material, which is available to authorized users.

Biofilms in chronic rhinosinusitis: Pathophysiology and therapeutic strategies

BACKGROUND

There is increasing evidence that biofilms are critical to the pathophysiology of chronic infections including chronic rhinosinusitis (CRS). Until relatively recently, our understanding of biofilms was limited. Recent advances in methods for biofilm identification and molecular biology have offered new insights into the role of biofilms in CRS. With these insights, investigators have begun to investigate novel therapeutic strategies that may disrupt or eradicate biofilms in CRS.

OBJECTIVE

This review seeks to explore the evidence implicating biofilms in CRS, discuss potential anti-biofilm therapeutic strategies, and suggest future directions for research.

RESULTS

The existing evidence strongly supports the role of biofilms in the pathogenesis of CRS. Several anti-biofilm therapies have been investigated for use in CRS and these are at variable stages of development. Generally, these strategies: 1) neutralize biofilm microbes; 2) disperse existing biofilms; or 3) disrupt quorum sensing. Several of the most promising anti-biofilm therapeutic strategies are reviewed.

CONCLUSIONS

A better understanding of biofilm function and their contribution to the CRS disease process will be pivotal to the development of novel treatments that may augment and, potentially, redefine the CRS treatment paradigm. There is tremendous potential for future research.

A comprehensive review of the nasal microbiome in chronic rhinosinusitis (CRS)

Chronic rhinosinusitis (CRS) has been known as a disease with strong infectious and inflammatory components for decades. The recent advancement in methods identifying microbes has helped implicate the airway microbiome in inflammatory respiratory diseases such as asthma and COPD. Such studies support a role of resident microbes in both health and disease of host tissue, especially in the case of inflammatory mucosal diseases. Identifying interactive events between microbes and elements of the immune system can help us to uncover the pathogenic mechanisms underlying CRS. Here we provide a review of the findings on the complex upper respiratory microbiome in CRS in comparison with healthy controls. Furthermore, we have reviewed the defects and alterations of the host immune system that interact with microbes and could be associated with dysbiosis in CRS.

Differential short palate, lung, and nasal epithelial clone 1 suppression in eosinophilic and noneosinophilic chronic rhinosinusitis with nasal polyps: implications for pathogenesis and treatment

PURPOSE OF REVIEW

Short palate, lung, and nasal epithelial clone 1 (SPLUNC1) is an epithelium-secreted protein that is involved in innate immunity. A protective role for SPLUNC1 in lower respiratory inflammation and chronic rhinosinusitis (CRS) has recently been recognized.

RECENT FINDINGS

An impaired epithelial immune barrier has been proposed to play a critical role in the pathogenesis of CRS. Recent research has demonstrated that SPLUNC1 is profoundly reduced in polyp tissues of CRS with nasal polyps (CRSwNP) compared with control tissues. Studies investigating the differential expression of SPLUNC1 in eosinophilic and noneosinophilic CRSwNP have been published. Nasal SPLUNC1 expression was inhibited by Th2 cytokines (IL-4 and IL-13) but was stimulated by toll-like receptor (TLR) agonists and glucocorticoids. Decreased SPLUNC1 expression in the sinus mucosa is associated with positive Pseudomonas aeruginosa bacterial colonization and poor surgical outcomes in CRS patients.

SUMMARY

These studies identify the role of SPLUNC1 in sinonasal innate immunity and the pathogenesis of CRS. Defective expression of SPLUNC1 in CRSwNP patients may lead to insufficient maintenance of the epithelial barrier function and enhanced bacterial colonization. The use of SPLUNC1 as a therapeutic target for CRSwNP remains to be determined.

Pediatric chronic rhinosinusitis

The goal of this review is to elucidate the pathogenic factors, histopathologic features, and special considerations that relate to pediatric versus adult chronic rhinosinusitis (CRS) and to emphasize differences and similarities between the adult and pediatric conditions. Emphasis is placed on understanding of the differences in pathogenic mechanisms, host-microbial interactions, potential defects in innate antimicrobial immunity, and the role of biofilm formation in pediatric versus adult CRS and how these translate to different approaches toward both medical and surgical management. Pediatric CRS can be viewed as evolving from acute bacterial rhinosinusitis into an uncomplicated "early" stage of CRS, later evolving into a persistent stage and, in some cases, evolving into a late "maladaptive-eosinophilic" stage disease. Given this potential evolution toward more irreversible disease, a plea can be made for improved recognition of and more aggressive early intervention for pediatric CRS, it is hoped, to prevent these long-term consequences. For the primary care physician, this may necessitate enlisting the support of a sinus specialist before the symptoms of CRS have persisted for months or years. It may also necessitate, in some cases, the use of sinus computed tomography imaging to demonstrate that sinus abnormalities have resolved. Other arguments can be made for prompt and comprehensive management of pediatric CRS, including the need to reduce the burden of illness, reduce health care costs, avoid unnecessary antibiotic use and its attendant effects toward promoting antibiotic resistant infections and, potentially, to reduce the development of important comorbidities, e.g., asthma.

A role for auto-immunity in chronic rhinosinusitis? Lessons learned from sub-epidermal bullous disorders of the skin

Chronic rhinosinusitis (CRS) is a frequent chronic condition, which has origins in complex interactions between genetic, immunological and microbial factors. The role of auto-immunity in CRS remains unclear, although recent studies have started to emerge in CRS patient refractory to maximal medical management. We discuss the possible auto-immunity link between CRS and other skin diseases, in particular acquired bullous dermatoses, and review the current evidence. We raise additional considerations for auto-immunity from both research and clinical standpoints.

Cytokine patterns in nasal secretion of non-atopic patients distinguish between chronic rhinosinusitis with or without nasal polys

BACKGROUND

Being one of the most common nasal diseases, chronic rhinosinusitis (CRS) is subdivided into CRS with nasal polyps (NP) and CRS without nasal polyps (CRSsNP). CRSsNP presents itself with a TH1 milieu and neutrophil infiltration, while NP is characterised by a mixed TH1/TH2 profile and an influx of predominantly eosinophils, plasma cells and mast cells. For the purpose of discovering disease-specific cytokine profiles, the present study compares levels of mediators and cytokines in nasal secretions between CRSsNP, NP, and healthy controls.

METHODS

The study included 45 participants suffering from NP, 48 suffering from CRSsNP and 48 healthy controls. Allergic rhinitis constituted an exclusion criterion. Nasal secretions, sampled using the cotton wool method, were analysed for IL-4, IL-5, IL-10, IL-12, IL-13, IL-17, IL-8, GM-CSF, G-CSF, IFN-γ, MCP-1, MIP-1α, MIP-1β, eotaxin, and RANTES, and for ECP and tryptase, using Bio-Plex Cytokine assay or ELISA, respectively.

RESULTS

Elevated levels of IL-5, IL-17, G-CSF, MCP-1, MIP-1α, MIP-1β, ECP, and tryptase, as well as decreased levels of IL-10, IL-12, IL-13, and IFN-γ were detected in NP. CRSsNP presented increased levels of RANTES and MIP-1β while IL-13 was decreased. No differences between the three groups were found for IL-4, IL-8, GM-CSF, and eotaxin.

CONCLUSIONS

The present work suggests a disequilibrium of TH1 and TH2, together with a down-regulation of regulatory T lymphocytes and up-regulated TH17 in NP. Moreover, elevated levels of diverse mediators represent the activation of various inflammatory cells in this disease entity. The inflammation in CRSsNP, however, is only weakly depicted in nasal secretions. Therefore, cytokines in nasal secretions may provide helpful information for differential diagnosis.

Chronic rhinosinusitis pathogenesis

There are a variety of medical conditions associated with chronic sinonasal inflammation, including chronic rhinosinusitis (CRS) and cystic fibrosis. In particular, CRS can be divided into 2 major subgroups based on whether nasal polyps are present or absent. Unfortunately, clinical treatment strategies for patients with chronic sinonasal inflammation are limited, in part because the underlying mechanisms contributing to disease pathology are heterogeneous and not entirely known. It is hypothesized that alterations in mucociliary clearance, abnormalities in the sinonasal epithelial cell barrier, and tissue remodeling all contribute to the chronic inflammatory and tissue-deforming processes characteristic of CRS. Additionally, the host innate and adaptive immune responses are also significantly activated and might be involved in pathogenesis. Recent advancements in the understanding of CRS pathogenesis are highlighted in this review, with special focus placed on the roles of epithelial cells and the host immune response in patients with cystic fibrosis, CRS without nasal polyps, or CRS with nasal polyps.

Involvement of Toll-like receptor 2 and epidermal growth factor receptor signaling in epithelial expression of airway remodeling factors

Staphylococcus aureus (SA) colonization and infection is common, and may promote allergic or inflammatory airway diseases, such as asthma, cystic fibrosis, and chronic rhinosinusitis by interacting with airway epithelial cells. Airway epithelial cells not only comprise a physical barrier, but also play key roles in immune, inflammatory, repair, and remodeling responses upon encounters with pathogens. To elucidate the impact of SA on epithelial-mediated remodeling of allergic airways, we tested the hypothesis that SA can enhance the remodeling process. Normal human bronchial epithelial (NHBE) cells were stimulated with heat-killed SA (HKSA) or transforming growth factor (TGF) α. Cell extracts were collected to measure mRNA (real-time RT-PCR) and signaling molecules (Western blot); supernatants were collected to measure protein (ELISA) after 24 hours of stimulation. Epidermal growth factor receptor (EGFR) signaling inhibition experiments were performed using a specific EGFR kinase inhibitor (AG1478) and TGF-α was blocked with an anti-TGF-α antibody. HKSA induced both mRNA and protein for TGF-α and matrix metalloproteinase (MMP) 1 from NHBE cells by a Toll-like receptor 2-dependent mechanism. Recombinant human TGF-α also induced mRNA and protein for MMP-1 from NHBE cells; anti-TGF-α antibody inhibited HKSA-induced MMP-1, suggesting that endogenous TGF-α mediates the MMP-1 induction by HKSA. HKSA-induced MMP-1 expression was suppressed when a specific EGFR kinase inhibitor was added, suggesting that EGFR signaling was mediating the HKSA-induced MMP-1 release. Exposure or colonization by SA in the airway may enhance the remodeling of tissue through a TGF-α-dependent induction of MMP-1 expression, and may thereby promote remodeling in airway diseases in which SA is implicated, such as asthma and chronic rhinosinusitis.

P-glycoprotein regulates Staphylococcus aureus enterotoxin B-stimulated interleukin-5 and thymic stromal lymphopoietin secretion in organotypic mucosal explants

BACKGROUND

T-helper 2 (Th2) inflammation is a hallmark of chronic rhinosinusitis with nasal polyps (CRSwNP) although the pathogenesis is poorly understood. P-glycoprotein (permeability glycoprotein, P-gp) is an efflux pump that is capable of regulating cytokine transport and is expressed within sinonasal mucosa. The purpose of this study was to examine if the oversecretion of interleukin 5 (IL-5) and thymic stromal lymphopoietin (TSLP) in CRSwNP could be explained through P-gp-mediated secretory pathways.

METHODS

Fifteen ethmoid mucosal explants were harvested from patients with CRS (n = 10) and CRSwNP (n = 10) and stimulated with Staphylococcus aureus enterotoxin B (SEB). P-gp was inhibited using zosuquidar trihydrochloride (herein Zosuquidar). P-gp expression was measured using real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). IL-5, IL-8, and TSLP secretion were quantified using ELISA.

RESULTS

P-gp protein was overexpressed in CRSwNP (28.32 ± 25.94 ng/mL per mg explant) as compared to CRS (10.74 ± 8.61; p = 0.01, 2-tailed Mann-Whitney U test). There was no difference in messenger RNA (mRNA) expression. SEB induced a significant increase in IL-5 and TSLP but not IL-8 secretion relative to control in the CRSwNP explants only. Subsequent P-gp inhibition significantly reduced IL-5 and TSLP secretion (p = 0.04 for both, 2-tailed Student t test) to control levels. The concentration of IL-5 and TSLP secretion were strongly and significantly correlated to the concentration of P-gp within the same explant (IL-5: r = 0.791, p = 0.001; TSLP: r = 0.687, p = 0.003; 2-tailed Spearman's rank-order correlation).

CONCLUSION

P-gp protein is expressed at higher concentrations in CRSwNP as compared to CRS. This overexpression directly contributes to the relative hypersecretion of IL-5 and TSLP. These findings suggest a novel mechanism for Th2 skewing in CRSwNP.

Different activations of toll-like receptors and antimicrobial peptides in chronic rhinosinusitis with or without nasal polyposis

Both up- and down-regulation of the Toll-like receptors (TLRs) and antimicrobial peptides (AMPs) of the sinonasal mucosa have already been associated with the pathogenesis of chronic rhinosinusitis with (CRSwNP) or without (CRSsNP) nasal polyps. The objective of this study was to determine the expression of all known TLR and several AMP genes and some selected proteins in association with allergy, asthma and aspirin intolerance (ASA) in CRS subgroups. RT-PCR was applied to measure the mRNA expressions of 10 TLRs, four defensins, lysozyme, cathelicidin and lactoferrin (LTF) in sinonasal samples from patients with CRSsNP (n = 19), CRSwNP [ASA(-): 17; ASA(+): 7] and in control subjects (n = 12). Protein expressions were detected with immunohistochemistry (n = 10). Statistical analysis was done with the Kruskal-Wallis ANOVA, Mann-Whitney U, and Student t test. TLR2, TLR5, TLR6, TLR7, TLR8, TLR9, β-defensins 1 and 4, cathelicidin and LTF mRNA expressions were significantly (p < 0.05) increased in CRSwNP, whereas only TLR2 and LTF were up-regulated in CRSsNP compared to controls. There was no statistical difference in respect of allergy, aspirin intolerance and smoking between CRSsNP, ASA(-) and ASA(+) CRSwNP patients. TLR2, TLR3, TLR4, LTF, β defensin 2 and lysozyme protein expressions were found to be elevated in macrophages of CRSwNP samples (p < 0.05). Gene expression analysis showed markedly different expressions in CRSwNP (6 out of 10 TLR and 4 out of 7 AMP genes were up-regulated) compared to CRSsNP (1/10, 1/7). The distinct activation of the innate immunity may support the concept that CRSsNP and CRSwNP are different subtypes of CRS. These findings were found to be independent from allergy, asthma, smoking, aspirin intolerance and systemic steroid application.

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.

Pathogenesis of nasal polyposis

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a complex inflammatory condition that affects a large proportion of the population world-wide and is associated with high cost of management and significant morbidity. Yet, there is a lack of population-based epidemiologic studies using current definitions of CRSwNP, and the mechanisms that drive pathogenesis in this disease remain unclear. In this review, we summarize the current evidence for the plethora of factors that likely contribute to CRSwNP pathogenesis. Defects in the innate function of the airway epithelial barrier, including diminished expression of antimicrobial products and loss of barrier integrity, combined with colonization by fungi and bacteria likely play a critical role in the development of chronic inflammation in CRSwNP. This chronic inflammation is characterized by elevated expression of many key inflammatory cytokines and chemokines, including IL-5, thymic stromal lymphopoietin and CCL11, that help to initiate and perpetuate this chronic inflammatory response. Together, these factors likely combine to drive the influx of a variety of immune cells, including eosinophils, mast cells, group 2 innate lymphoid cells and lymphocytes, which participate in the chronic inflammatory response within the nasal polyps. Importantly, however, future studies are needed to demonstrate the necessity and sufficiency of these potential drivers of disease in CRSwNP. In addition to the development of new tools and models to aid mechanistic studies, the field of CRSwNP research also needs the type of robust epidemiologic data that has served the asthma community so well. Given the high prevalence, costs and morbidity, there is a great need for continued research into CRS that could facilitate the development of novel therapeutic strategies to improve treatment for patients who suffer from this disease.

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.

Biofilms in chronic rhinosinusitis: what is new and where next?

Background:

Chronic rhinosinusitis is a common, heterogeneous condition. An effective means of mitigating disease in chronic rhinosinusitis patients remains elusive. A variety of causes have been implicated, with the biofilm theory gaining increasing prominence.

Objective:

This article reviews the literature on the role of biofilms in chronic rhinosinusitis, in terms of pathophysiology and with regard to avenues for future treatment.

Methods:

A systematic review of case series was performed using databases with independently developed search strategies, including Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, Cochrane library, and Zetoc, in addition to conference proceedings and a manual search of literature, with the last search conducted on 18 January 2014. The search terms included the following, used in various combinations to maximise the yield of articles identified: ‘biofilms’, ‘chronic rhinosinusitis’, ‘DNase’, ‘extracellular DNA’ and ‘biofilm dispersal’.

Results:

The existing evidence lends further support for the role of biofilms (particularly the Staphylococcus aureus phenotype) in more severe, recalcitrant disease and poorer surgical outcomes.

Conclusion:

Multimodality treatment, with a shift in paradigm to incorporate anti-biofilm strategies, is likely to form the mainstay of future recalcitrant chronic rhinosinusitis management.

ICON: chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a public health problem that has a significant socio-economic impact. Moreover, the complexity of this disease due to its heterogeneous nature based on the underlying pathophysiology - leading to different disease variants - further complicates our understanding and directions for the most appropriate targeted treatment strategies. Several International/national guidelines/position papers and/or consensus documents are available that present the current knowledge and treatment strategies for CRS. Yet there are many challenges to the management of CRS especially in the case of the more severe and refractory forms of disease. Therefore, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), a collaboration between EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus (ICON) on Chronic Rhinosinusitis. The purpose of this ICON on CRS is to highlight the key common messages from the existing guidelines, the differences in recommendations as well as the gaps in our current knowledge of CRS, thus providing a concise reference. In this document we discuss the definition of the disease, its relevance, pharmacoeconomics, pathophysiology, phenotypes and endotypes, genetics and risk factors, natural history and co-morbidities as well as clinical manifestations and treatment options in both adults and children comprising pharmacotherapy, surgical interventions and more recent biological approaches. Finally, we have also highlighted the unmet needs that wait to be addressed through future research.

Verapamil modulates interleukin-5 and interleukin-6 secretion in organotypic human sinonasal polyp explants

BACKGROUND

Verapamil is an L-type calcium channel blocker (CCB) that has been shown to have immunomodulatory properties in a variety of tissues. The goal of this study was determine whether verapamil is capable of regulating cytokine secretion in sinonasal polyps and to compare this effect to dexamethasone, an established immunosuppressive corticosteroid.

METHODS

This was an institutional review board (IRB)-approved study in sinonasal polyp explants derived from 8 patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Polyps were incubated with dexamethasone or verapamil for 24 hours followed by an additional 24 hours with Staphylococcal enterotoxin B (SEB). Concentrations of secreted cytokines over each exposure period were determined by enzyme-linked immunosorbent assay (ELISA) and are expressed as a percent. Results were compared using a 2-tailed Student t test.

RESULTS

The percent of SEB-stimulated interleukin-5 (IL-5) secretion (mean ± standard deviation [SD], 339.94% ± 315.48%) between the second and first treatment periods was significantly reduced following exposure to dexamethasone (74.08% ± 26.77%, p < 0.05) and verapamil (119.99% ± 69.32%, p < 0.05). The percent of SEB-stimulated IL-6 secretion (217.53% ± 89.51%) was also significantly reduced following exposure to verapamil (148.82% ± 79.15%, p < 0.05) but not dexamethasone (148.86% ± 145.24%). Finally, the percent of SEB-stimulated thymic stromal lymphopoietin (TSLP) secretion (37.86% ± 18.88%) demonstrated a nonsignificant trend toward reduction with both dexamethasone (31.15% ± 35.28%) and verapamil (20.14% ± 12.10%).

CONCLUSION

Although the mechanism has yet to be fully understood, L-type CCBs are capable of reducing inflammation in multiple tissues. Verapamil was specifically found to reduce airway goblet cell hyperplasia and eosinophilic infiltration in a murine asthma model. Our data support these findings suggesting that verapamil can modulate T-helper cell type 2 (Th2)-associated cytokine secretion in sinonasal polyp explants. This data points to a possible therapeutic role for CCBs in the management of CRSwNP.

Differential expression of innate immunity genes in chronic rhinosinusitis

BACKGROUND

Prior research has identified several components of the innate immune system that may play a significant role in chronic rhinosinusitis (CRS), but the role of innate immunity in patients with CRS is poorly understood. The objective of this study was to determine differential expression of innate immunity genes in the mucosa of patients with CRS with nasal polyposis (CRSwNP) and CRS without nasal polyposis (CRSsNP) when compared with controls.

METHODS

Control patients (n = 9) and patients with CRS (n = 36) who failed medical management were prospectively enrolled. Ethmoid mucosa samples were harvested during surgery and quantitative real-time polymerase chain reaction was used to determine levels of mRNA expression of Toll-like receptor (TLR) 2 and TLR9 and interleukin-22 receptor (IL-22R). The average change in crossover threshold and fold change were calculated and differences between controls, CRSwNP, and CRSsNP were compared. Statistical analysis was performed using the Kruskall-Wallis and adjusted Mann-Whitney U tests.

RESULTS

Patients with CRSwNP (n = 16) and CRSsNP (n = 20) showed lower mean expression of TLR2 (p < 0.05) compared with controls. Patients with CRSsNP showed significantly higher mean expression of IL-22R (p < 0.05) than controls.

CONCLUSION

The sinonasal innate immune system may have a significant role in the development of CRS. We found differential expression of innate immune mediators between patients with and without nasal polyposis. These results provide further evidence of disruption of innate immunity at the mucosal level in CRS and highlight differences between polyp- and non-polyp-forming CRS phenotypes at the molecular level. In addition to our knowledge, this is the first report of altered IL-22R expression in CRSsNP patients. This study was a part of the clinical trial NCT01332136 registered in www.clinicaltrials.gov.

Deprived TLR9 expression in apparently healthy nasal mucosa might trigger polyp-growth in chronic rhinosinusitis patients

Background

The origin of nasal polyps in chronic rhinosinusitis is unknown, but the role of viral infections in polyp growth is clinically well established. Toll-like receptors (TLRs) have recently emerged as key players in our local airway defense against microbes. Among these, TLR9 has gained special interest in viral diseases. Many studies on chronic rhinosinusitis with nasal polyps (CRSwNP) compare polyp tissue with nasal mucosa from polyp-free individuals. Knowledge about changes in the turbinate tissue bordering the polyp tissue is limited.

Objectives

To analyse the role of TLR9 mediated microbial defense in tissue bordering the polyp.

Methods

Nasal polyps and turbinate tissue from 11 patients with CRSwNP and turbinate tissue from 11 healthy controls in total were used. Five biopsies from either group were analysed immediately with flow cytometry regarding receptor expression and 6 biopsies were used for in vitro stimulation with a TLR9 agonist, CpG. Cytokine release was analysed using Luminex. Eight patients with CRSwNP in total were intranasally challenged with CpG/placebo 24 hours before surgery and the biopsies were collected and analysed as above.

Results

TLR9 expression was detected on turbinate epithelial cells from healthy controls and polyp epithelial cells from patients, whereas TLR9 was absent in turbinate epithelial cells from patients. CpG stimulation increased the percentage cells expressing TLR9 and decreased percentage cells expressing VEGFR2 in turbinate tissue from patients. After CpG stimulation the elevated levels of IL-6, G-CSF and MIP-1β in the turbinate tissue from patients were reduced towards the levels demonstrated in healthy controls.

Conclusion

Defects in the TLR9 mediated microbial defense in the mucosa adjacent to the anatomic origin of the polyp might explain virus induced polyp growth. CpG stimulation decreased VEGFR2, suggesting a role for CpG in polyp formation. The focus on turbinate tissue in patients with CRSwNP opens new perspectives in CRSwNP-research.

Histopathological evaluation of chronic rhinosinusitis: a critical review

BACKGROUND

Chronic rhinosinusitis (CRS) consists of a constellation of symptoms, including facial pressure/pain, hyposmia, rhinorrhea, and nasal congestion. On histopathological evaluation, the disease can be divided into pathophysiologically distinct subgroups. This study systematically reviews the literature regarding the unique histopathological findings of the various subtypes of CRS to determine the potential diagnostic value of performing tissue analysis of CRS specimens beyond routine hematoxylin and eosin (H&E) staining.

METHODS

A PubMed search was untaken to identify articles that evaluated the histopathological features of CRS. Six hundred fifty-four relevant articles were identified and after application of specific exclusion criteria, 71 articles were further reviewed in detail.

RESULTS

All articles included analysis of tissue samples from in-office biopsies or intraoperative specimens of patients who underwent sinus surgery. CRS was often further divided into subgroups and compared with each other and with a control group. The subgroups included CRS with and without nasal polyps, asthmatic and nonasthmatic patients, and with and without eosinophilia. Distinct inflammatory mediators were found for the different subgroups. Twenty-eight articles evaluated these inflammatory markers for their potential value as prognostic indicators.

CONCLUSION

CRS is a heterogeneous disease based on its histopathological findings. Information that is obtainable from light microscopy, but typically goes unreported, can serve as valuable prognostic indictors. However, routine H&E staining is suboptimal in distinguishing among the various subgroups of CRS. Assessment of specific inflammatory mediators in sinus mucosa specimens may help provide prognostic information and guide more tailored treatment for the individual patient.

Fungal extracts detected in eosinophilic chronic rhinosinusitis induced cytokines from the nasal polyp cells

Objectives/Hypothesis

The role of fungi in chronic rhinosinusitis (CRS) is still controversial. The present study was conducted to detect and identify fungal species from the nasal polyp tissues of eosinophilic and noneosinophilic CRS, and to determine the role of fungal antigens in cytokine production.

Study Design

Prospective study.

Methods

Thirty-five specimens of nasal polyps were collected from patients with CRS and examined for fungus using culture, histology, and polymerase chain reaction analysis. The secretion of 14 cytokines stimulated by fungal extracts using dispersed nasal polyp cells (DNPCs) was determined by multiplex immunoassay.

Results

There was no microbiological growth (including fungus) in the cultures of homogenized nasal polyps. Furthermore, Grocott methanamine silver staining for all nasal polyps showed no fungal bodies. Sixteen of 35 samples of the nasal polyps showed amplification of fungal DNA. In none of the mucosa of the sphenoid sinus was fungal DNA detected. The number of eosinophils in the nasal polyps in which fungal DNA was detected was significantly higher than in the nasal polyps in which fungal DNA was not detected (P < .01). The extract of fungus enhanced the secretion of eosinophil-associated cytokines such as interleukine (IL)-5, IL-13, IL-17A, and RANTES (regulated on activation normal T-cell expressed and secreted), and proinflammatory cytokines such as IL-6, IL-8, tumor necrosis factor-α, and granulocyte-macrophage colony-stimulating factor from DNPCs.

Conclusions

The present study offers direct evidence supporting that fungal elements modify the inflammatory response in the nasal polyps of eosinophilic CRS.

Level of Evidence: NA

Host-microbial interactions in patients with chronic rhinosinusitis

There has been considerable investigation of host-microbial interactions in patients with chronic rhinosinusitis (CRS) in hopes of elucidating mechanisms of disease and better treatment. Most attention has been paid to bacterial infection and potential underlying defects in innate immunity. Bacterial biofilm is present in most patients with CRS undergoing surgical intervention, and its presence is associated with more severe disease and worse surgical outcomes. A role for viral or fungal infection in patients with CRS is less clear. There is no evidence for a primary defect in mucociliary clearance in most patients with CRS. Decreased levels of certain antimicrobial proteins, most notably lactoferrin, have been found in sinus secretions, whereas levels of other antimicrobial proteins have been found to be normal. No primary defects in Toll-like receptors have been found in patients with CRS, although a 50% reduced expression of Toll-like receptor 9 was reported in patients with recalcitrant nasal polyps. A polymorphism in a bitter taste receptor was recently associated with refractory CRS and persistent Pseudomonas aeruginosa infection. A downregulation of innate immunity by maladaptive T_H2 tissue inflammation has also been described in patients with recalcitrant nasal polyps, suggesting a link to persistent infection. To date, an effective means of restoring host-microbial balance and mitigating disease in patients with CRS remains elusive.

Damage-associated molecular patterns and their receptors in upper airway pathologies

Inflammation of the nasal (rhinitis) and sinus mucosa (sinusitis) are prevalent medical conditions of the upper airways that are concurrent in many patients; hence the terminology "rhinosinusitis". The disease status is further defined to be "chronic" in case symptoms persist for more than 12 weeks without resolution. A diverse spectrum of external factors including viral and bacterial insults together with epithelial barrier malfunctions could be implicated in the chronicity of the inflammatory responses in chronic rhinosinusitis (CRS). However, despite massive research efforts in an attempt to unveil the pathophysiology, the exact reason for a lack of resolution still remains poorly understood. A novel set of molecules that could be implicated in sustaining the inflammatory reaction may be found within the host itself. Indeed, besides mediators of inflammation originating from outside, some endogenous intracellular and/or extracellular matrix (ECM) components from the host can be released into the extracellular space upon damage induced during the initial inflammatory reaction where they gain functions distinct from those during normal physiology. These "host-self" molecules are known to modulate inflammatory responses under pathological conditions, potentially preventing resolution and contributing to the development of chronic inflammation. These molecules are collectively classified as damage-associated molecular patterns (DAMPs). This review summarizes the current knowledge regarding DAMPs in upper airway pathologies, also covering those that were previously investigated for their intracellular and/or ECM functions often acting as an antimicrobial agent or implicated in tissue/cell homeostasis, and for which their function as a danger signaling molecule was not assessed. It is, however, of importance to assess these molecules again from a point of view as a DAMP in order to further unravel the pathogenesis of CRS.

Natural killer cells from patients with chronic rhinosinusitis have impaired effector functions

Natural killer (NK) cells are multicompetent lymphocytes of the innate immune system that play a central role in host defense and immune regulation. Although increasing evidence suggests that innate immunity plays a key role in the pathogenesis of chronic rhinosinusitis (CRS), the role of NK cells in CRS has been poorly studied. This study aimed to characterize the peripheral blood NK cells from patients with CRS, and to compare the functions of these cells with those from non-CRS controls. The correlation between NK cell functional activity and prognosis was also assessed. Eighteen CRS patients and 19 healthy non-CRS controls were included. The patients with CRS were classified into two subgroups, namely a treatment-responsive group and recalcitrant group. NK cell degranulation was determined by measuring the cell surface expression of CD107a against 721.221 and K562 cells. Intracytoplasmic cytokine production was determined by flow cytometry. Compared to the controls, the NK cells of CRS group had an impaired ability to degranulate and to produce cytokines such as IFN-γ and TNF-α. The recalcitrant subgroup showed the most severe defects in NK cell effector functions. Moreover, the decreased NK cell functions in patients with CRS were associated with poor prognostic factors such as concomitant asthma and peripheral blood eosinophilia. NK cells, which were originally named for their ability to mediate spontaneous cytotoxicity towards diseased cells including infected cells, may play an important role in regulating the inflammatory process in CRS pathogenesis.

Rhinosinusitis and asthma-microbiome and new perspectives

PURPOSE OF REVIEW

Microbiome is one of the new perspectives in human health research, including airway diseases. There are several publications about the relationship of the microbiome and allergic diseases. Although pathogenesis of chronic rhinosinusitis (CRS) as well as its relationship with asthma has been widely investigated, the relationship of the microbiome and CRS is not yet well known.

RECENT FINDINGS

The relationship between the hygiene hypothesis and microorganisms inside the human body and in the environment around it has been clearly shown. Furthermore, several researchers have reported that the microorganisms in the gut play a major role in regulating the immune cells that are of relevance to asthma and allergic diseases, such as Th1, Th2, Th17, Treg and dendritic cells as well as Toll-like receptors. Reduced contact of people with natural environmental features and biodiversity may adversely affect the human commensal microbiota and its immunomodulatory capacity.Some studies have shown a close relationship between CRS and Staphylococcus aureus, anaerobes and so on in the nasal cavity or paranasal sinuses, although the relationship between CRS and microorganisms in the gut has not been demonstrated.

SUMMARY

In this review, we summarized about the microbiome, mainly in asthma and allergic diseases. The relationship between asthma and CRS has been clearly shown, and in particular, CRS with nasal polyps (CRSwNP) has been considered to be Th2-dominant. Studies examining environmental microbial exposure in populations at risk for CRS are necessary to improve our understanding of the role this factor plays in disease development.

Unilateral pathological lesions of paranasal sinuses removed by endoscopic surgery

INTRODUCTION

The aim of this study was to analyze the incidence and nature of unilateral pathological lesions of paranasal sinuses in patients who had endoscopic sinus surgery performed in ENT.

MATERIALS AND METHODS

In the years 2006-2011 endoscopic sinus surgery for unilateral pathological lesions of paranasal sinuses was performed in 1847 patients (838 women and 1009 men). The enrollment of patients was based on the findings of otolaryngological clinical and subjective examinations, assessment of the paranasal sinuses on three-dimensional CT scans, and laboratory examinations. Based on the analysis of medical history data, including gender, age, the type of surgical procedure performed, and histopathological findings the cases were finally analyzed.

RESULTS

Pathological lesions of the paranasal sinuses were localized on the left side in 132 (57%) patients, and on the right side in 100 (43%) patients. Of the 232 patients with unilateral pathological changes, 41.8% subjects underwent endoscopic sinus surgery for polypotic changes in the ethmoid and maxillary sinuses; 28.4% for the maxillary sinus; 10.8% for the ethmoid, maxillary and frontal sinuses; and 8.6% patients for all paranasal sinuses on one side. The number of operations of only one sinus was considerably lower: sphenoid sinus, 4.7%; ethmoid sinus, 2.2%; and frontal sinus, 1.7% patients. The histopathological analysis of unilateral pathological lesions removed by endoscopic surgery showed chronic paranasal sinusitis with polyps in 56.5% patients; chronic paranasal sinusitis in 22.8% patients; and maxillary sinus cyst was confirmed in 11.6% patients. In 5.1% patients inverted papilloma was diagnosed and in 2.2% patients the presence of osteoma was found.

CONCLUSIONS

Unilateral paranasal pathological lesions, leaving aside rather typical maxillary sinus cysts, require a particularly thorough pre-operative diagnosis and a precise histopathological assessment.

Expression of RANTES, eotaxin-2, ICAM-1, LFA-1 and CCR-3 in chronic rhinosinusitis patients with nasal polyposis

PURPOSE

To compare gene expression of the chemokines RANTES and eotaxin-2, its receptor, CCR-3, adhesion molecule ICAM-1 and its receptor LFA-1 in eosinophilic polyps and in control normal nasal mucosa.

METHODS

Gene expression was quantified by Real Time PCR in polyps (n=35) and in healthy nasal mucosa (n=15).

RESULTS

Eosinophilic polyps showed a higher expression of eotaxin-2 and RANTES, but not of CCR-3, ICAM-1 or LFA-1 compared to control nasal mucosa.

CONCLUSION

Eosinophilic polyps present greater expression of eotaxin-2 and RANTES, but not of CCR-3, ICAM-1 or LFA-1 compared to control nasal mucosa.

Potential role of Alternaria and Cladosporium species in canine lymphoplasmacytic rhinitis

OBJECTIVES

To evaluate the possible role of Alternaria and Cladosporium species in the pathogenesis of canine lymphoplasmacytic rhinitis by comparing the amount of specific fungal DNA in nasal mucosal biopsies between dogs without nasal neoplasia and those with lymphoplasmacytic rhinitis or nasal neoplasia.

METHODS

Quantitative real-time polymerase chain reaction (qPCR) assays detecting DNA from Alternaria and Cladosporium fungi were applied to nasal mucosal biopsies collected from dogs with lymphoplasmacytic rhinitis (n = 8), dogs with nasal neoplasia (n = 10) and control animals (n = 10). A copy number for each sample was calculated using a standard curve of known copy number and differences amongst groups were assessed using Kruskal-Wallis tests.

RESULTS

No significant difference was found between the groups. Low levels of Alternaria DNA (10-100 copies/PCR) were detected in one sample; very low levels of DNA (<10 copies/qPCR) were detected in 6 samples, and 21 samples were negative. Low levels of Cladosporium DNA were detected in 2 samples; very low levels of DNA in 18; and 8 were negative.

CLINICAL SIGNIFICANCE

Results of this study reveal that Alternaria and Cladosporium species are part of the canine nasal flora, and that these fungi are probably not involved in the pathogenesis of lymphoplasmacytic rhinitis.

Gene expression signatures: a new approach to understanding the pathophysiology of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a complex inflammatory disease with variable disease manifestation. Though external risk factors are associated with development and/or persistence of CRS, the host mucosal response is also important, as nasal epithelium acts as a physical and immune barrier. Under inflammatory stress, the nasal epithelium can undergo injury, followed by a rapid remodeling response ranging from epithelial hyperplasia, to goblet-cell metaplasia, to denudation, loss of cilia, fibrosis, and basement membrane thickening. Identification of gene expression signatures and molecular pathways in CRS pathogenesis have now begun to contribute significantly to a better understanding of the genetic and molecular alterations underlying CRS development and progression. Genetic studies are especially illuminating when multiple gene variants synergize within a permissive environmental context, and are expected to guide development of more effective therapeutic targets for CRS treatment.

Endotypes and phenotypes of chronic rhinosinusitis: a PRACTALL document of the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma & Immunology

Chronic rhinosinusitis (CRS) is a complex disease consisting of several disease variants with different underlying pathophysiologies. Limited knowledge of the mechanisms of these disease subgroups is possibly the greatest obstacle in understanding the causes of CRS and improving treatment. It is generally agreed that there are clinically relevant CRS phenotypes defined by an observable characteristic or trait, such as the presence or absence of nasal polyps. Defining the phenotype of the patient is useful in making therapeutic decisions. However, clinical phenotypes do not provide full insight into all underlying cellular and molecular pathophysiologic mechanisms of CRS. Recognition of the heterogeneity of CRS has promoted the concept that CRS consists of multiple groups of biological subtypes, or "endotypes," which are defined by distinct pathophysiologic mechanisms that might be identified by corresponding biomarkers. Different CRS endotypes can be characterized by differences in responsiveness to different treatments, including topical intranasal corticosteroids and biological agents, such as anti-IL-5 and anti-IgE mAb, and can be based on different biomarkers that are linked to underlying mechanisms. CRS has been regarded as a single disease entity in clinical and genetic studies in the past, which can explain the failure to identify consistent genetic and environmental correlations. In addition, better identification of endotypes might permit individualization of therapy that can be targeted against the pathophysiologic processes of a patient's endotype, with potential for more effective treatment and better patient outcomes.

Genetics of chronic rhinosinusitis: state of the field and directions forward

The cause of chronic rhinosinusitis (CRS) remains unclear. Study of the genetic susceptibility to CRS might be a valuable strategy to understand the pathogenesis of this burdensome disorder. The purpose of this review is to critically evaluate the current literature regarding the genetics of CRS in a comprehensive fashion. The most promising findings from candidate gene studies include the cystic fibrosis transmembrane conductance regulator gene (CFTR), as well as genes involved in antigen presentation, innate and adaptive immune responses, tissue remodeling, and arachidonic acid metabolism. We also review the few hypothesis-independent genetic studies of CRS (ie, linkage analysis and pooling-based genome-wide association studies). Interpretation of the current literature is limited by challenges with study design, sparse replication, few functional correlates of associated polymorphisms, and inadequate examination of linkage disequilibrium or expression quantitative trait loci for reported associations. Given the relationship of CRS to other airway disorders with well-characterized genetic components (eg, asthma), study of the genetics of CRS deserves increased attention and investment, including the organization of large, detailed, and collaborative studies to advance knowledge of the mechanisms that underlie this disorder.

Role of innate immunity in the pathogenesis of chronic rhinosinusitis: progress and new avenues

Chronic rhinosinusitis is a heterogeneous and multifactorial disease with unknown etiology. Aberrant responses to microorganisms have been suggested to play a role in the pathophysiology of the disease. Research has focused on the presence, detection, response to, and eradication of these potential threats. Main topics seem to center on the contribution of structural cells such as epithelium and fibroblasts, on the consequences of activation of pattern-recognition receptors, and on the role of antimicrobial agents. This research should be viewed not only in the light of a comparison between healthy and diseased individuals, but also in a comparison between patients who do or do not respond to treatment. New players that could play a role in the pathophysiology seem to surface at regular intervals, adding to our understanding (and the complexity) of the disease and opening new avenues that may help fight this incapacitating disease.