Immunoglobulin E to staphylococcal and streptococcal toxins in patients with chronic sinusitis/nasal polyposis

Impact of type 2 targeting biologics on acute exacerbations of chronic rhinosinusitis

Background: Acute exacerbations of chronic rhinosinusitis (AECRS) are associated with significant morbidity and decreased quality of life. There are sparse data assessing the real-world impact of biologics on AECRS. Objectives: We sought to determine the impact of type 2-targeting biologics on the frequency of medication use for AECRS episodes. Methods: Antibiotic and/or systemic corticosteroid courses for AECRS were identified in a retrospective study from November 2015 to February 2020, at a single academic health system. The estimated yearly rates for antibiotic and corticosteroid courses were evaluated before and after initiation of type 2 biologics. Results: One-hundred and sixty-five patients with chronic rhinosinusitis (CRS) had received either omalizumab (n = 12), mepolizumab (n = 42), benralizumab (n = 44), dupilumab (n = 61), or reslizumab (n = 6). Seventy percent had CRS with nasal polyps, and 30% had CRS without nasal polyps. All the patients had asthma. When all the biologics were combined, the estimated yearly rate for antibiotics for AECRS decreased from 1.34 (95% confidence interval [CI], 1.12-1.59) to 0.68 (95% CI, 0.52-0.88) with biologic use (49% reduction, p < 0.001). Those with frequent AECRS (three or more courses of antibiotics in the 1 year before biologic use) had a larger degree of reduction, with an estimated yearly rate of 4.15 (95% CI, 3.79-4.55) to 1.58 (95% CI, 1.06-2.35) with biologic use (n = 27; 62% reduction; p < 0.001). Within the total cohort, the estimated yearly rate for systemic corticosteroids for AECRS decreased from 1.69 (95% CI, 1.42-2.02) to 0.68 (95% CI, 0.53-0.88) with biologic use (60% reduction; p < 0.001). Conclusion: Type 2-targeting biologics reduced medication use for AECRS. This suggested that biologics may be a therapeutic option for patients with frequent AECRS.

What is the contribution of IgE to nasal polyposis?

Taking a novel approach, this narrative review collates knowledge about nasal polyposis and the biological functions of IgE in several diseases (allergic rhinitis, allergic asthma, nonsteroidal anti-inflammatory drugs-exacerbated respiratory disease, and chronic spontaneous urticaria) to consider which IgE-mediated mechanisms are relevant to nasal polyposis pathology. A type 2 eosinophil-dominated inflammatory signature is typical in nasal polyp tissue of European patients with nasal polyposis, with a shift toward this endotype observed in Asian populations in recent years. Elevated polyclonal IgE is present in the nasal tissue of patients with and without allergy. It is derived from many different B-cell clones and, importantly, is functional (proinflammatory). Staphylococcus aureus enterotoxins are thought to act as superantigens, inducing production of polyclonal IgE via B-cell and T-cell activation, and triggering release of inflammatory mediators. In some patients, exposure to antigens/triggers leads to production of high levels of antigen-specific IgE, which mediates cross-linking of the high-affinity IgE receptor on various cells, causing release of inflammatory mediators. The efficacy of omalizumab confirms IgE as an important inflammatory mediator in nasal polyposis. By blocking IgE, omalizumab targets the T2 inflammation in nasal polyposis, reduces nasal polyp score and improves symptoms.

Role of the Intestinal Epithelium and Its Interaction With the Microbiota in Food Allergy

The intestinal epithelial tract forms a dynamic lining of the digestive system consisting of a range of epithelial cell sub-types with diverse functions fulfilling specific niches. The intestinal epithelium is more than just a physical barrier regulating nutrient uptake, rather it plays a critical role in homeostasis through its intrinsic innate immune function, pivotal regulation of antigen sensitization, and a bi-directional interplay with the microbiota that evolves with age. In this review we will discuss these functions of the epithelium in the context of food allergy.

Staphylococcus aureus Infection and Persistence in Chronic Rhinosinusitis: Focus on Leukocidin ED

Chronic rhinosinusitis (CRS) is thought to be a multifactorial disease that includes a direct involvement of bacteria that trigger inflammation and contribute to CRS pathogenesis. Staphylococcus aureus infection and persistence is associated with chronic rhinosinusitis (CRS), and it may be particularly relevant in the form with nasal polyps (CRSwNP). The large array of exotoxins deployed by S. aureus is instrumental for the bacterium to warrant its infection and dissemination in different human body districts. Here, we analyze the common Th2 environment in CRSwNP and prospect a possible dynamic role played by S. aureus leukocidins in promoting this chronic inflammation, considering leukocidin ED (LukED) as a strong prototype candidate worth of therapeutic investigation. CCR5 is an essential target for LukED to exert its cytotoxicity towards T cells, macrophages and dendritic cells. Therefore, CCR5 blockade might be an interesting therapeutic option for CRS and, more specifically, persistent and relapsing CRSwNP. In this perspective, the arsenal of CCR5 antagonists being developed to inhibit HIV-1 entry (CCR5 being the major HIV-1 co-receptor) could be easily repurposed for CRS therapeutic investigation. Finally, direct targeting of LukED by neutralizing antibodies could represent an important additional solution to S. aureus infection.

Sinus Infections, Inflammation, and Asthma

There is an important link between the upper and lower respiratory tracts whereby inflammation in one environment can influence the other. In acute rhinosinusitis, pathogen exposures are the primary driver for inflammation in the nose, which can exacerbate asthma. In chronic rhinosinusitis, a disease clinically associated with asthma, the inflammation observed is likely from a combination of an impaired epithelial barrier, dysregulated immune response, and potentially infection (or colonization) by specific pathogens. This review explores the associations between rhinosinusitis and asthma, with particular emphasis placed on the role of infections and inflammation.

Chronic rhinosinusitis: pathogenesis, therapy options, and more

INTRODUCTION

When rhinosinusitis - the inflammation of the nasal cavity and paranasal sinuses - persists for over 12 weeks, it is termed 'chronic rhinosinusitis' (CRS). Both innate and adaptive immunity contribute to the heterogeneous inflammatory pathogenesis of CRS, which is driven by genetic and environmental factors and the microbiome. CRS is classified by the presence of polyps. Molecular mechanisms in CRS with nasal polyps are similar to those in atopic diseases.

AREAS COVERED

This review focuses on the immune pathogenesis of CRS, differences between the two CRS subtypes, and latest treatments that may aid in the provision of personalized medicine.

EXPERT OPINION

Basic research in the last decade has helped significantly in enhancing our knowledge of the pathophysiologic processes of CRS, due to which there is now a better understanding of the associated natural history, physiopathology, novel treatments, and prevention strategies. Treatment success depends on the clarification of the underlying pathogenesis and disease-contributing factors. The exploration of disease endotypes and introduction of novel agents are important advancements. Prior studies performed without disease-endotyping resulted in the inefficiency of certain drugs and insignificant results. The identification of biomarkers, development of personalized approaches, and utilization of disease algorithms are required for CRS therapy success.

Role of Superantigens in Allergic Inflammation: Their Relationship to Allergic Rhinitis, Chronic Rhinosinusitis, Asthma, and Atopic Dermatitis

OBJECTIVES

Our intention was to review all material published to date regarding superantigens (SAgs) and allergy from an otorhinolaryngological viewpoint to understand this association more clearly.

METHODS

We identified all materials published mentioning both SAg and allergic rhinitis (AR), chronic sinusitis, asthma, and atopic dermatitis (AD) that are indexed on PubMed, Google, or the ProQuest Central databases.

RESULTS

Staphylococcus aureus is a significant bacterial pathogen in humans and has the ability to produce enterotoxins with superantigenic features. The inflammatory response in allergy seen in both B cell and T cell may be attributed to SAgs. Sufferers of both allergic asthma with rhinitis and AR alone produce serological evidence of immunoglobulin E formation to SAgs produced by S. aureus. Perennial AR sufferers carry S. aureus more frequently and the presence of the organism within the nasal cavity may exacerbate perennial AR. SAg produced by S. aureus potentially worsens the asthmatic inflammatory response within the airway and may lead to the airways becoming hyperresponsive, as well as possibly activating T cells if asthmatic control is poor. Staphylococcal SAgs potentially increase the risk of developing chronic rhinosinusitis with nasal polyposis, additionally being a marker for more severe disease. If SAgs bring about chronic inflammatory responses in the nose and sinuses, then T cells excreting interferon-gamma may be a crucial mediator. In allergic dermatitis, S. aureus could be a key player in exacerbation of the condition. Even in younger pediatric patients with allergic dermatitis, allergic hypersensitivity to SAgs is frequent and may be a factor explaining how severe the condition becomes.

CONCLUSION

Just as SAgs are known to feature in many allergic conditions, they play their part in AR, chronic rhinosinusitis, asthma, and AD. Further research is required before the relationship between SAgs and allergy can be adequately explained.

Understanding the Role of Biofilms and Superantigens in Chronic Rhinosinusitis

PURPOSE OF REVIEW

This review explores recent discoveries in our understanding of how biofilms and superantigens contribute to the pathogenesis of chronic rhinosinusitis (CRS). It also examines clinical implications and novel treatment approaches for biofilm associated CRS.

RECENT FINDINGS

While the role of biofilms in CRS has been studied for 14 years, research interest has now turned toward elucidating new methods of biofilm detection, microbial diversity, and novel treatment approaches. Recent studies on biofilm superantigens aim to clarify the immunological mechanisms of upper airway inflammation, particularly the type-2 response seen in nasal polyposis.

SUMMARY

Biofilms are a topic of research interest for their role in the pathogenesis of chronic rhinosinusitis, particularly when they elute superantigens. New studies on this topic focus on the molecular and cellular mechanisms at play.

Staphylococcal Exotoxins and Nasal Polyposis: Analysis of Systemic and Local Responses

Background

Staphylococcal exotoxins have been implicated in the pathogenesis of several chronic inflammatory diseases including atopic dermatitis (AD), asthma, and, most recently, chronic rhinosinusitis with nasal polyposis (CRS/NP). In severe AD, these toxins act both as superantigens (SAg), triggering massive T-cell activation, and as conventional allergens, triggering toxin-specific immunoglobulin E (IgE) in the serum. In CRS/NP, evidence for both processes has been reported but it is unclear whether these processes are linked. The aim of this study was to correlate SAg activity as inferred by staphylococcal-specific T-cell receptor (TCR) V-β expansion in the polyp and blood of CRS/NP patients with staphylococcal-specific anti-IgE antibodies in the serum.

Methods

IgE antibodies to staphylococcal exotoxin A (SEA), staphylococcal exotoxin B (SEB), and toxic shock syndrome toxin (TSST) 1 were measured in the serum of 12 individuals with CRS/NP before functional endoscopic sinus surgery. Flow cytometry was used to analyze the SEA, SEB, and TSST-1–specific TCR V-β domains on the T cells from the polyp and blood of these patients.

Results

Serum SEA-, SEB-, and TSST-1-specific IgE antibodies were detected in 0/12 (0%), 6/12 (50.0%), and 9/12 (75%) of CRS/NP patients, respectively. Evidence of SAg effect in the polyp lymphocytes (TCR V-β expansion in both CD4+ and CD8+ subsets) was noted in 7/12 (58.3%) patients. Five of 6 CRS/NP patients had overlapping evidence of a systemic IgE response and TCR V-β expansion, suggestive of exposure to the same exotoxin. No patients had evidence a SAg effect in blood lymphocytes. Nine of 12 subjects also had coexistent asthma.

Conclusion

These results provide evidence for a local SAg effect in 7/12 (58.3%) polyp patients and establish a positive correlation of V-β expansion with the presence of corresponding toxin-specific IgE in the serum.

Infectious Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a persistent inflammatory disease that affects a multitude of people worldwide. The pathogenesis of CRS involves many factors including genetics, status of the sinonasal microbiome, infections, and environmental influences. Comorbidities associated with CRS include asthma, allergic rhinitis, bronchiectasis, and certain kinds of immunodeficiency. CRS can be divided into different subtypes based on endotypes and phenotypes. Infectious CRS is one such category. The etiology of infectious CRS is usually secondary to chronic bacterial infection that commonly begins with a viral upper respiratory tract infection. Humoral antibody deficiencies can underlie difficult-to-treat or recurrent CRS. Infectious CRS can be treated with antimicrobials, topical or oral corticosteroids, and nasal saline irrigations. Patients with CRS and humoral immunodeficiency may require an aggressive treatment approach including immunoglobulin replacement therapy. Despite advancements in the field of CRS, targeted therapies and reliable biomarkers are still lacking.

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.

Different roles of Staphylococcus aureus enterotoxin in different subtypes of nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial disease. The pathogenesis of CRSwNP remains unclear. This study was designed to investigate the role of inflammation and Staphylococcus aureus enterotoxin (SE) in this disease. The study included a total of 74 patients with CRSwNP and 6 controls. A serum Phadiatop assay was conducted to detect atopy status, and serum eosinophil cationic protein (ECP) and total immunoglobulin (Ig)E levels were determined using ELISA. SEA, SEB, total IgE, ECP and myeloperoxidase (MPO) levels in nasal tissue supernatant were measured using ELISA. The results indicated that 15 (22.1%) patients had systemic allergies. On the basis of the ECP/MPO ratio, the patients were divided into an eosinophilic CRSwNP group (n=18) and a non-eosinophilic CRSwNP group (n=56). The total ECP/MPO ratio was 0.572, with a notable bias toward neutrophilic inflammation. The supernatant ECP and MPO levels were elevated in the CRSwNP group compared with the control group, but no significant difference in the serum total IgE and ECP levels were observed between the CRSwNP and control groups. In addition, the non-eosinophilic and eosinophilic CRSwNP groups showed significant elevations in supernatant total IgE, SEA and SEB levels compared with the control group. Thus, it may be concluded that allergy is a common pathogenesis of CRSwNP, and neutrophilic inflammation is present in most Chinese CRSwNP patients. Additionally, local indicators reflect the inflammatory status more accurately than do serum indicators. SEs may act as an infection factor rather than as a superantigen in Chinese non-eosinophilic CRSwNP patients. Thus, long-term antibiotic therapy may be an option for Chinese non-eosinophilic CRSwNP patients.

Biofilm Formation by Staphylococcus Aureus and Pseudomonas Aeruginosa is Associated with an Unfavorable Evolution after Surgery for Chronic Sinusitis and Nasal Polyposis

OBJECTIVES: To determine whether biofilm-forming capacity of bacteria demonstrated in chronic rhinosinusitis (CRS) has an impact on persistence of the disease following endoscopic sinus surgery (ESS).

METHOD: Thirty-one bacterial strains recovered from 19 patients with CRS at least 1 year post-ESS. Evolution of disease was assessed by questionnaire and endoscopy as favorable or unfavorable. The bacteria were cultured on a 96-well culture plaque and a semi-quantitative method using crystal violet to quantify biofilm production was used.

RESULTS: Twenty-two of 31 samples produced a biofilm thicker or equal to the positive control. Biofilm production was noted in 6/10 Pseudomonas aeruginosa isolates, 8/10 Staphylococcus aureus, and 8/11 coagulase-negative staphylococci. Biofilm formation was associated with a poor evolution for Pseudomonas aeruginosa and Staphylococcus aureus, but not coagulase-negative staphylococcus.

CONCLUSION: There is a correlation between in vitro biofilm-producing capacity by Pseudomonas aeruginosa and Staphylococcus aureus and unfavorable evolution after ESS, suggesting a role for biofilm production in chronic sinusitis.

The Etiology and Pathogenesis of Chronic Rhinosinusitis: a Review of Current Hypotheses

Chronic rhinosinusitis (CRS) is a broad clinical syndrome that is characterized by prolonged mucosal inflammation of the nose and paranasal sinuses, and is typically divided into two subtypes based on the presence or absence of nasal polyps. The etiology and pathogenesis of both forms remain areas of active research. Over the last 15 years, a number of hypotheses have been proposed to explain all or part of the clinical CRS spectrum. These hypotheses reflect the concept that CRS results from a dysfunctional interplay between individual host characteristics and factors exogenous to the host. Six broad theories on CRS etiology and pathogenesis are discussed as follows: (1) the "fungal hypothesis," (2) the "superantigen hypothesis," (3) the "biofilm hypothesis," and (4) the "microbiome hypothesis," all of which emphasize key environmental factors, and (5) the "eicosanoid hypothesis" and (6) the "immune barrier hypothesis," which describe specific host factors. These theories are reviewed, and the evidence supporting them is critically appraised.

Staphylococcus enterotoxin A induces MUC5B expression via Toll-like receptor 2, extracellular signal-regulated kinase 1/2, and p38 mitogen-activated protein kinase in human airway epithelial cells

BACKGROUND

Staphylococcus aureus enterotoxins are known to induce an inflammatory response of the airways, increase sensitization to inhaled allergens, and decrease T-cell sensitivity to steroids. However, the effects of Staphylococcus enterotoxin A (SEA) on mucin secretion of airway epithelial cells still have not been reported. Therefore, in this study, the effect and brief signaling pathway of SEA on MUC5B expression were investigated in human airway epithelial cells.

METHODS

In the mucin-producing human NCI-H292 airway epithelial cells and the primary cultures of normal nasal epithelial cells, the effect and signaling pathway of SEA on MUC5B expression were investigated using reverse transcriptase-polymerase chain reaction (PCR), real-time PCR, enzyme immunoassay, and immunoblot analysis with several specific inhibitors and small interfering RNA (siRNA).

RESULTS

SEA increased MUC5B mRNA and protein expression. Toll-like receptor 2 (TLR2) mRNA expression was significantly increased after treatment with SEA. Knockdown of TLR2 by siRNA significantly blocked SEA-induced MUC5B mRNA expression. SEA significantly activated phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK). U0126 (ERK1/2 MAPK inhibitor) and SB203580 (p38 MAPK inhibitor) significantly inhibited SEA-induced MUC5B mRNA expression. In addition, knockdown of ERK1/2 and p38 MAPK by siRNA significantly blocked SEA-induced MUC5B mRNA expression. Furthermore, the phosphorylation of ERK1/2 and p38 MAPK was significantly blocked by knockdown of TLR2 by siRNA.

CONCLUSION

These results show for the first time that SEA induces MUC5B expression via TLR2, ERK1/2, and p38 MAPK signaling pathway in human airway epithelial cells.

Serum levels of specific IgE to Staphylococcus aureus enterotoxins in patients with chronic rhinosinusitis

The aim of this study was to determine the prevalence of Staphylococcus aureus enterotoxins (SEs) in the serum from patients with chronic rhinosinusitis (CRS) and its involvement in the condition. Thirty CRS patients without nasal polyps (CRSsNP), 40 CRS patients with nasal polyps (CRSwNP), and 30 healthy controls were enrolled in this study. Peripheral blood was obtained and analyzed to measure the serum levels of total IgE, specific IgE to SEA, SEB and SEC, and eosinophil cationic protein (ECP) using ImmunoCAP assays. The positive rate and level of serum specific IgE to SEB, but not to SEA or SEC, were significantly higher in CRSwNP patients compared with the controls (P=0.027 and P=0.021, respectively). No significant differences were found between CRSsNP patients and controls, or between CRSsNP and CRSwNP patients. Serum total IgE was significantly elevated and positively correlated with SEB-specific IgE in the CRSsNP (P<0.001; r=0.393, P=0.032) and CRSwNP (P<0.001; r=0.581, P<0.001) groups. ECP was also significantly increased in the CRSsNP (P=0.002) and CRSwNP (P<0.001) groups, but not correlated with specific IgE to SEs in either CRS group. The results suggest that SEB may play a role in the pathogenesis of CRSwNP.

Allergic sensitization in Canadian chronic rhinosinusitis patients

BACKGROUND

Chronic rhinosinusitis (CRS) is a societal burden and cause of morbidity in Canada; however, the prevalence of allergic sensitization in Canadian CRS patients has remained poorly characterized.

OBJECTIVE

In this study, we used skin prick test (SPT) and specific immunoglobulin E (sIgE) and G (sIgG) titers to regionally relevant allergen sources in order to determine whether allergic sensitization is more prevalent in CRS patients compared to chronic idiopathic urticaria (CIU) control patients.

METHODS

One hundred and fifty eight subjects (19-70 years of age) were recruited into the study. 101 subjects had a confirmed diagnostic history of CRS and 57 subjects with a clinical diagnosis of CIU were recruited as controls. Enrolled subjects underwent SPT to a panel of perennial and seasonal allergens and sIgE titers were quantified to selected environmental allergen mixes (grass, mold, and tree species) using Phadia ImmunoCAP. sIgG was additionally quantified to Alternaria alternata, Aspergillus versicolor, Cladosporium herbarum, and Stachybotrys atra. Differences between CRS and control CIU patient SPT and serological data were examined by chi-squared analysis and analysis of variance.

RESULTS

Reactivity to at least one SPT extract occurred in 73% of CRS patients. Positive SPT reactivity to A. alternata (odds ratio (OR): 4.34, 95% confidence interval: 1.57, 12.02), cat (OR: 3.23, 95% CI: 1.16, 9.02), and ragweed (OR: 2.31, 95% CI: 1.02, 5.19) extracts were more prevalent in patients with CRS (p < 0.05). Although dust mite and timothy grass sensitization approached statistical significance in the chi-squared analysis of SPT data, other common perennial and seasonal allergens were not associated with CRS. No statistically significant differences were observed between mean sIgE and sIgG titers in CRS and control patients.

CONCLUSIONS

This study supports previous data that suggests A. alternata sensitization is associated with CRS; however, these findings additionally highlight the contribution of other regionally important allergens including cat and ragweed.

Streptococcal superantigens: categorization and clinical associations

Superantigens are key virulence factors in the immunopathogenesis of invasive disease caused by group A streptococcus. These protein exotoxins have also been associated with severe group C and group G streptococcal infections. A number of novel streptococcal superantigens have recently been described with some resulting confusion in their classification. In addition to clarifying the nomenclature of streptococcal superantigens and proposing guidelines for their categorization, this review summarizes the evidence supporting their involvement in various clinical diseases including acute rheumatic fever.

Etiology, diagnosis and management of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a common health care problem, yet many aspects of this diagnosis remain poorly understood. Its etiology is often debated and remains a significant area of research. The diagnosis of CRS is based on subjective symptoms, duration of symptoms and objective evidence of inflammation. Each of these criteria must be met to make a diagnosis of CRS. Management of CRS often involves a combination of systemic and topical therapies with surgery reserved for patients who fail medical therapy. This review provides a comprehensive view of the etiology, diagnosis and management of CRS.

Detection of Staphylococcal Exotoxins in Antrochoanal Polyps and Chronic Rhinosinusitis with Nasal Polyps

Objective

Staphylococcal exotoxins have been reported in the pathogenesis of many chronic inflammatory diseases. Recent reports have hypothesized that staphylococcal exotoxins might be related to inflammatory mucosal changes seen in chronic sinusitis with nasal polyps (CRS-NPs). Staphylococcal exotoxins have the capacity to act as superantigens (SAgs), bypassing normal antigen processing and directly stimulating a massive inflammatory response. The objective of this study was to analyze polyp tissue samples from patients with antrochoanal polyps (ACPs) and CRS-NPs for the presence of staphylococcal exotoxins.

Study Design

Prospective cohort study.

Setting

Tertiary medical center.

Subjects and Methods

Tissue samples were obtained from 29 patients and 16 controls. Thirteen of 29 patients had ACPs, and 16 had CRS-NPs. Specimens were analyzed for the presence of 5 staphylococcal exotoxins (SEA, SEB, SEC, SED, and toxic shock syndrome toxin–1) using enzyme-linked immunosorbent assay (ELISA).

Results

At least 1 toxin was detected in 7 of 13 patients with ACPs and in 13 of 16 patients with CRS-NPs, whereas it was detected in only 4 controls. There were no statistically significant differences between ACP and control groups ( P = .063). Our results showed a statistically significant association between toxin detection and patients with CRS-NPs ( P = .003).

Conclusion

Inflammatory triggers in ACP remain a subject of debate, and this study does not support the hypothesis that staphylococcal exotoxins may play a role in ACP ethiopathogenesis. Our research is consistent with the possibility of SAgs as etiological agents in the development of bilateral nasal polyposis.

Staphylococcus aureus enterotoxin B contributes to induction of nasal polypoid lesions in an allergic rhinosinusitis murine model

BACKGROUND

Studies on the pathophysiology of nasal polyps in human subjects have been limited; thus an animal model is needed. There is increasing evidence supporting the role of Staphylococcus aureus enterotoxin B (SEB) in the pathogenesis of nasal polyposis. The aim of this study was to investigate the histological and immunologic effects of SEB on the formation of nasal polypoid lesions in an allergic rhinosinusitis murine model.

METHODS

After induction of an ovalbumin (OVA)-induced allergic rhinosinusitis, OVA with SEB (5 or 500 ng) was instilled into the nasal cavity of mice for 8 weeks. Control mice did not receive SEB or OVA instillation. Histopathological changes were observed using hematoxylin and eosin, Sirius red, Giemsa, Masson's trichrome, and Alcian blue stains. The levels of interleukin (IL)-4, IL-5, IL-8, IL-13, eotaxin, interferon gamma, total IgE, and OVA-specific IgE from serum or nasal lavage fluid were measured using enzyme-linked immunosorbent assay.

RESULTS

The group treated with OVA plus 5 ng of SEB had significantly more mucosal lesions with epithelial disruption and nasal polypoid lesions than mice treated with OVA only, showing a significant increase in the infiltration of total inflammatory cells, eosinophils, and lymphocytes than the other groups. Levels of IL-5, eotaxin, and OVA-specific IgE in nasal lavage fluid were increased in the group treated with OVA plus 5 ng of SEB than in the other groups. A higher number of secretory cells in the groups treated with OVA plus SEB was observed than in other groups.

CONCLUSION

Low-dose SEB induced nasal polypoid lesions with an increased eosinophilic infiltration in an allergic rhinosinusitis murine model.

Synergism of Staphylococcus aureus colonization and allergic reaction in the nasal cavity in mice

BACKGROUND

The aim of this study is to investigate the reciprocal effect of Staphylococcus aureus colonization and allergic rhinitis in an allergy model of mice.

METHODS

BALB/c mice with intraperitoneal ovalbumin (OVA) sensitization and/or intranasal S. aureus inoculation were prepared. The following 4 groups were designed: an OVA-sensitized S. aureus-inoculated (AR-SA) group, an OVA-sensitized uninoculated (AR) group, a nonsensitized S. aureus-inoculated (SA) group, and a nonsensitized uninoculated (control) group. After intranasal OVA challenge, nasal lavage fluid, peripheral blood, and nasal mucosa were collected. Polymorphonuclear cells in the nasal lavage fluid were counted, serum OVA-specific IgE and IgG1 were measured by enzyme immunoassays, and IL-4, IL-5, and IFN-γ mRNAs in the nasal mucosa were assessed by quantitative real-time reverse transcription-PCR. The number of S. aureus in the nasal mucosa and lavage fluid was counted.

RESULTS

Both eosinophil and neutrophil counts were larger in the AR-SA group than in the other groups. Both IgE and IgG1 levels were higher in the AR and AR-SA groups than in the SA and control groups, and the IgG1 level was higher in the AR-SA group than in the AR group. The expression of IL-4 mRNA was higher in the AR-SA group than in the other groups, and the expression of IL-5 mRNA was higher in the AR-SA group than in the SA group. The AR-SA group showed higher counts of S. aureus in the nasal mucosa than the SA group.

CONCLUSION

These results indicate the mutually potentiating effect of S. aureus colonization and allergic rhinitis.

The systemic and pulmonary immune response to staphylococcal enterotoxins

In response to environmental cues the human pathogen Staphylococcus aureus synthesizes and releases proteinaceous enterotoxins. These enterotoxins are natural etiologic entities of severe food poisoning, toxic shock syndrome, and acute diseases. Staphylococcal enterotoxins are currently listed as Category B Bioterrorism Agents by the Center for Disease Control and Prevention. They are associated with respiratory illnesses, and may contribute to exacerbation of pulmonary disease. This likely stems from the ability of Staphylococcal enterotoxins to elicit powerful episodes of T cell stimulation resulting in release of pro-inflammatory cytokines. Here, we discuss the role of the immune system and potential mechanisms of disease initiation and progression.

Evidence for altered activity of the IL-6 pathway in chronic rhinosinusitis with nasal polyps

BACKGROUND

IL-6 activates T(H)17 cells and regulates the response of B lymphocytes and regulatory T cells. The IL-6 receptor and the membrane protein, glycoprotein 130 (gp130), form an active signaling complex that signals through signal transducer and activator of transcription 3 (STAT3) and other signaling molecules. Both the IL-6 receptor (IL-6R) and gp130 can be found in soluble forms that regulate the pathway.

OBJECTIVE

We measured IL-6 signaling components and IL-17 in chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP), CRS without nasal polyps (CRSsNP), and controls to assess the IL-6 pathway in CRS.

METHODS

IL-6, soluble IL-6R, soluble gp130 (sgp130), and IL-17 were measured in sinus tissue extracts and in nasal lavage fluid by either cytokine bead array or ELISA. phosphoSTAT3 (p-STAT3) was determined by Western blot and by immunohistochemistry.

RESULTS

IL-6 protein was significantly (P < .001) increased in CRSwNP compared with CRSsNP and controls. Soluble IL-6R was also increased in nasal polyp compared with control tissue (P < .01). Despite elevated IL-6 and sIL-6R, IL-17A, E, and F were undetectable in the sinus tissue from most of the patients with CRS and controls. p-STAT3 levels were reduced in the polyp tissue, possibly indicating reduced activity of IL-6 in the tissue. sgp130 was elevated in CRSwNP compared with CRSsNP and controls.

CONCLUSION

p-STAT3 levels are decreased in CRSwNP despite increased levels of IL-6 and sIL-6R and are associated with the absence of an IL-17 response. This may be a response to elevated levels of sgp130, a known inhibitor of IL-6 signaling. These results indicate that IL-6 and its signaling pathway may be altered in CRSwNP.

Perspectives on the etiology of chronic rhinosinusitis

PURPOSE OF REVIEW

This article reviews recent insights surrounding the etiology and pathogenesis of chronic rhinosinusitis. In particular, we highlight the increasing recognition of host-mediated mechanisms in driving mucosal inflammation.

RECENT FINDINGS

Published differences between epithelium from patients with chronic rhinosinusitis and normal controls can be classified into several broad categories. Alterations are reported in the various components of the epithelial innate immune system including epithelial-expressed pattern-recognition receptors (PRRs) and the levels of antimicrobial innate immune effector molecules. Other studies demonstrate differences in the proteins involved in maintaining epithelial barrier integrity. Finally, recent studies show in chronic rhinosinusitis that epithelial-derived cytokines, chemokines and inducible surface proteins are involved in recruiting and activating cells of the adaptive immune system.

CONCLUSION

The sinonasal epithelium provides a mechanical and innate immune barrier to a diverse array of environmental agents. This barrier also plays a key role in regulating the acquired mucosal immune response in the nose. Recent studies suggest that defects in this barrier may foster development of chronic sinonasal inflammation in response to environmental agents, and pathogenic or commensal organisms. The ability to dissect and analyze defects in the inflammatory response in rhinosinusitis may help identify novel targets for drug development.

Short-term antibiotics treatment in patients with nasal polyps and enterotoxins producing Staphylococcus aureus strains

Enterotoxins produced by Staphylococcus aureus (SA) can act as super-antigens and thus influence the course of chronic rhinosinusitis with nasal polyps (NP). The aim of this study was to determine if antibiotic treatment administered after endoscopic sinus surgery (ESS) for NP can positively influence the course of the disease compared to placebo. After ESS, 23 patients who tested positive, in a perioperative culture, for SA strains producing enterotoxins A-E and TSST-1, were randomized into two groups. Group A which in addition to standard treatment received oral anti-staphylococcal antibiotics for 3 weeks. Group B received a placebo. Both groups were compared preoperatively, and at 3 and 6 months after surgery using a symptom-specific score, an endoscopic score and the SNOT-22 quality of life questionnaire. Slightly better results were achieved in patients who received antibiotic therapy. However, the differences were not statistically significant. Regardless of post-operative treatment, approximately 30% of patients had a SA-negative culture 6 months after surgery.

Epithelium, inflammation, and immunity in the upper airways of humans: studies in chronic rhinosinusitis

The purpose of this review is to discuss recent findings made during studies of the upper airways and sinuses of people with chronic rhinosinusitis (CRS) in the context of the literature. CRS is a chronic inflammatory disorder affecting nearly 30 million Americans and is generally resistant to therapy with antibiotics and glucocorticoids (Meltzer EO and coworkers, J Allergy Clin Immunol 2004;114:155-212). We have formed a collaboration that consists of otolaryngologists, allergists, and basic scientists to address the underlying immunologic and inflammatory processes that are occurring in, and possibly responsible for, this disease. The main emphasis of our work has been to focus on the roles that epithelium, in the sinuses and upper airways, plays as both a mediator and regulator of immune and inflammatory responses. It is not our intention here to provide a comprehensive review of the literature in this area, but we will try to put our work in the context of the findings of others (Kato A and Schleimer RP, Curr Opin Immunol 2007;19:711-720; Schleimer RP and coworkers, J Allergy Clin Immunol 2007;120:1279-1284). In particular, we discuss the evidence that epithelial cell responses are altered in CRS, including those relevant to regulation of dendritic cells, T cells, B cells, and barrier function.

Staphylococcal Infection and Toxin Production in Chronic Rhinosinusitis

Background

The association between bacterial colonization and different forms of chronic rhinosinusitis (CRS) has not been well documented. One of the most recent hypotheses is superantigen (SA)-induced inflammation, resulting in up-regulation of lymphocytes to produce cytokines, and other inflammatory mediators that strongly modify the disease. Staphylococcus aureus, frequently encountered in nasal passages, can produce enterotoxins that can act as SAs.

Methods

A prospective case control study was performed. Sixty-four patients diagnosed with CRS (group 1), CRS with nasal polyps (CRSwNP) (group 2), and 15 control subjects were enrolled. Swabs were taken from the middle meatus of all subjects for identification of S. aureus carriers. Positive carriers were analyzed for the presence of toxic shock syndrome toxin (TSST) 1 using reverse passive latex agglutination as well as polymerase chain reaction.

Results

The rate of nasal carriage of

S. aureus in CRS was 42.8%, that of CRSwNP was 45.4%, and that of the control group was 13.3%. The difference between both groups of CRS and the control group was found to be highly significant (p < 0.001). The detection of TSST-1 was significantly higher (p < 0.001) in both groups of CRS patients than in the control group. Finally, the difference in colonization of TSST-1 was highly significant (p < 0.001) between the CRS group 1 and CRSwNP group 2 patients.

Conclusion

Identifying SAs and understanding how they elicit the pathogenic condition in CRS will be central in revealing ways to ameliorate their effects and properly treat these conditions.

Prostaglandin E(2) suppresses staphylococcal enterotoxin-induced eosinophilia-associated cellular responses dominantly through an E-prostanoid 2-mediated pathway in nasal polyps

BACKGROUND

Recent investigations have revealed that staphylococcal enterotoxins (SEs), COX metabolism, or both might participate in the pathogenesis of eosinophilic airway diseases, such as chronic rhinosinusitis with nasal polyposis.

OBJECTIVE

We sought to determine whether COX metabolism, especially prostaglandin (PG) E(2), plays a significant role in SE-induced cellular responses in nasal polyps.

METHODS

Dispersed nasal polyp cells (DNPCs) were prepared from nasal polyps by means of enzymatic digestion. DNPCs were cultured with SEB in the presence or absence of COX inhibitors (diclofenac and indomethacin) for 72 hours; then the levels of IL-5, IL-13, RANTES, and eotaxin in the supernatants were measured. The effect of PGE(2) on SEB-induced responses by diclofenac-treated DNPCs was examined, especially in terms of receptor specificity.

RESULTS

DNPCs produced significant amounts of IL-5, IL-13, and RANTES in response to SEB. COX inhibitors significantly increased the production of these cytokines. The degree of local eosinophilia was significantly and positively correlated with the changes in IL-5 production induced by diclofenac treatment. PGE(2) significantly and dose-dependently inhibited SEB-induced IL-5, IL-13, and RANTES production by diclofenac-treated DNPCs. E-prostanoid (EP) 2 receptor-selective agonist strongly inhibited the production of all 3 cytokines. EP3 and EP4 receptor-selective agonists partially suppressed these responses, whereas EP1 receptor-selective agonist did not. Interestingly, all of the combined treatments with 2 of the 4 EP receptor-selective agonists significantly inhibited the SEB-induced responses by diclofenac-treated DNPCs.

CONCLUSIONS

These results suggest that PGE(2) inhibits the pathogenesis of SEB-induced eosinophilic inflammation primarily through the EP2-mediated pathway in patients with chronic rhinosinusitis with nasal polyposis.

Superantigens and the expression of T-cell receptor repertoire in chronic rhinosinusitis with nasal polyps

CONCLUSIONS

Staphylococcal exotoxins (SEs), acting as superantigens, activate the beta variable chains of T-cell receptors (TCRVbeta) with subsequent massive proliferation and corresponding excursion of gene spectra, thereby contributing to the etiology of chronic rhinosinusitis with nasal polyps (CRSwNP).

OBJECTIVES

To demonstrate the presence of SEs in sinonasal mucosa, and determine the effect of superantigens on the T cells expressing the target of superantigen, i.e. TCRVbeta in patients with CRSwNP.

MATERIALS AND METHODS

Nasal mucosa and sinonasal polyp tissue specimens were obtained from 37 patients with CRS (22 with bilateral nasal polyps, 15 without nasal polyps). Specimens were assayed by enzyme-linked immunosorbent assay (ELISA) for SEs (SEA, SEB, SEC, SED) and toxic shock syndrome toxin type-1 (TSST-1), and analyzed by flow cytometry and reverse transcriptase-polymerase chain reaction (RT-PCR), respectively, to determine the expression of TCRVbeta repertoire.

RESULTS

In the CRSwNP subjects 12 of 22 samples (54.54%) demonstrated reactivity for staphylococcal exotoxins. There was no positive result in the CRS without nasal polyps or normal control group. There was a high percentage of Vbeta+ T cells in the superantigen-positive group. The expressional intensity of Vbeta3, 14, 15, 17, and 20 was specifically enhanced in SEB-positive subjects, as well as that of Vbeta2 and 6.1-3 in specimens that were TSST-1-positive compared with those that were negative for superantigens (all p<0.05). There were no dominantly expressed Vbeta fragments in ELISA-negative specimens.

Intranasal fungi and chronic rhinosinusitis: what is the relationship?

OBJECTIVES

The aim of this study was to investigate the effects of intranasal fungi on chronic rhinosinusitis (CRS).

METHODS

Forty-one patients with CRS were included in the study. The patients were put into 2 groups, with and without intranasal fungi as detected by polymerase chain reaction, and were compared in terms of different laboratory and clinical parameters of CRS. A chi2 test was used to analyze statistical differences between the 2 groups.

RESULTS

Serum eosinophilia, eosinophilia in the nasal mucus, prick and intradermal test positivity for fungi, elevated total IgE, fungal-specific IgE, prevalence of symptoms, frequency of bronchial asthma, aspirin sensitivity, and nasal polyposis did not differ significantly between the 2 groups of patients (p > .05).

CONCLUSIONS

The findings of this study failed to reveal a clear correlation between the presence of fungi in the nasal passage and various factors that are assumed to be involved in the pathogenesis or clinical course of CRS. If fungi have a role in the pathogenesis of CRS, it may be via other mediators and reactions rather than IgE and type I hypersensitivity. However, the sample size was relatively small, and further studies with more cases are needed on the same topic.

Use of an in vitro assay for determination of biofilm-forming capacity of bacteria in chronic rhinosinusitis

BACKGROUND

Bacterial biofilms are increasingly implicated in the pathogenesis of chronic disease and have been established in several chronic ear, nose, and throat conditions, including chronic sinusitis (CRS). However, this relies on specialized imaging methods not widely available. We wished to assess the capacity of an easily performed, inexpensive in vitro test to assess biofilm production by bacteria recovered from individuals with CRS with or without nasal polyposis.

METHODS

Bacterial isolates were recovered from patients consulting an academic tertiary rhinology practice. Biofilm formation was determined with an in vitro staining method using crystal violet. Ten isolates of Pseudomonas aeruginosa, Staphylococcus aureus, and 11 of coagulase-negative staphylococcus from patients with CRS having previously undergone endoscopic sinus surgery for >1 year were assessed. Samples were cultured 24 hours at 37 degrees C on 96-well plates in tryptic soy broth 0.5% glucose medium. After staining with crystal violet, optical density at 570 nm was measured to quantify biofilm production. Biofilm-forming capacity was compared with positive and negative controls for each species obtained from commercial sources.

RESULTS

Positive controls all grew biofilms, with a tendency of lesser biofilm formation at higher dilutions. Twenty-two of 31 clinical samples produced a biofilm greater or equal to the positive control. Biofilm was recovered consistently for all three species studied.

CONCLUSION

This in vitro assessment method is capable of detecting biofilm-forming capacity in bacteria recovered from individuals with CRS. This simple assay may be a useful complement to existing techniques for clinical research.

Superantigens and chronic rhinosinusitis II: analysis of T-cell receptor V beta domains in nasal polyps

BACKGROUND

The superantigen (SAg) hypothesis of chronic rhinosinusitis (CRS) suggests that toxins within the nose stimulate massive oligoclonal expansion of T-cell populations with subsequent eosinophil recruitment and tissue inflammation. SAgs are capable of activating 1 x 10(4) more lymphocytes than conventional antigens by binding specific Vbeta-domains of the T-cell receptor (TCR). The net effect is skewing from the normal Vbeta-profile by oligoclonal expansion of specific domains. This study will assess polyp tissue for evidence of an SAg response in CRS with nasal polyps (CRSwNP).

METHODS

This study consists of a prospective analysis of 18 CRSwNP subjects undergoing sinus surgery. Flow cytometry was used to analyze the distribution of 24 specific TCR V beta-domains in lymphocytes from polyp tissue and blood. Evidence of oligoclonal expansion was tabulated for each specimen and defined as mean normative percentage + 2 SD.

RESULTS

Eighteen of 18 CRSwNP subjects showed expansion of polyp lymphocytes expressing TCRs with specific V beta-domains. The average number of V beta-clones per CRSwNP subject was seven in polyp lymphocytes but only two in blood lymphocytes.

CONCLUSION

The current results indicate that polyp lymphocytes exhibit significant oligoclonal expansion of specific V beta-domains. These data are considered diagnostic of a SAg effect. The corresponding blood profile is much less, suggesting that the nose is the primary source of stimulus. Although the trigger(s) for this expansion are unknown, these data are consistent with the hypothesis that staphylococcal toxins are central to the development of CRSwNP.

Bibliography. Current world literature. Nose and paranasal sinuses

PURPOSE OF REVIEW

Patients with advanced head and neck cancer are being treated with chemo-radiotherapy, and life is being prolonged, with or without persistent disease, for longer than was previously. Hypercalcaemia may present in patients with advanced or disseminated head and neck cancer, and, as such, these patients may present to a larger variety of clinicians for advice concerning their symptoms and illness. Modes of presentation of hypercalcaemia and treatment strategies are reviewed.

RECENT FINDINGS

There were previously few large series of head and neck cancer patients diagnosed with hypercalcaemia, which may or may not have been related to their cancer being treated. Investigations, by way of blood/serum calcium level, may identify such patients. Patients with cancer-related hypercalcaemia have a poor prognosis, but many may respond temporarily to treatment when offered, with an improvement of their quality of life and death.

SUMMARY

Hypercalcaemia should and must be considered in all patients who have or possibly have a diagnosis of a head and neck cancer and who present unwell with symptoms of fatigue, lethargy and somnolence. Investigation must include serum calcium (corrected for serum albumin binding) and parathyroid hormone level. Patients may be treated by a combination of rehydration and bisulphonate therapy until the serum calcium is reduced to a level below 3 mmol/l. The majority of patients diagnosed with hypercalcaemia due to head and neck malignancy die of their diseases in the short term, but some may enjoy a prolongation of life with reasonable quality if diagnosed and treated aggressively.

Chronic rhinosinusitis and superantigens

This article discusses the potential role of bacterial superantigens (SAgs) in chronic rhinosinusitis with nasal polyposis (CRS/NP). First, it briefly describes SAgs, focusing on how they interact with the immune system by binding to T-cell receptors (TCR) and major histocompatibility complex (MHC) class II molecules. Second, it discusses the role of SAgs in other chronic inflammatory diseases.Finally, it presents evidence for the role of SAgs in the pathogenesis and maintenance of CRS/NP focusing on current research and future considerations.

Superantigens and chronic rhinosinusitis: detection of staphylococcal exotoxins in nasal polyps

OBJECTIVE/HYPOTHESIS

The role of infectious agents in the etiology of chronic rhinosinusitis with nasal polyposis (CRSwNP) remains unclear. Recent studies have provided indirect evidence of exposure to staphylococcal exotoxins in the blood and polyp tissue of patients with CRSwNP. These exotoxins have the capacity to act as superantigens, bypassing normal antigen processing and directly stimulating a massive inflammatory response. The objective of the study was to analyze mucus and polyp tissue samples from patients with CRSwNP for the presence of staphylococcal exotoxins.

STUDY DESIGN

Prospective study.

METHODS

Tissue and mucus samples were obtained from 42 patients undergoing endoscopic sinus surgery for chronic rhinosinusitis and 11 normal control patients. Twenty-nine of 42 patients had chronic rhinosinusitis with bilateral nasal polyposis, 2 had antrochoanal polyps, and 11 had chronic rhinosinusitis without nasal polyps. Eleven patients without chronic rhinosinusitis or polyps served as normal control patients. Specimens were analyzed for the presence of five staphylococcal exotoxins (SEA, SEB, SEC, SED, and toxic shock syndrome toxin type 1 [TSST-1]) using enzyme-linked immunosorbent assay (ELISA). Histological analysis of specimens and mean eosinophil counts were correlated with the presence of toxin.

RESULTS

At least one toxin was detected in 14 of 29 patients with bilateral nasal polyposis. Nine of the 14 patients also had positive findings for additional toxins. The dominant histological pattern in the CRSwNP patient group was polypoid mucosa with edema, which was found in both ELISA-positive and ELISA-negative patients. Mean eosinophil counts tended to be higher in ELISA-positive patients with polyps compared with patients without toxin detection. No toxin was detected in the 11 specimens taken from normal control patients. Only 1 of the 13 patients with CRS without polyps had positive ELISA results for toxin.

CONCLUSION

The current study demonstrates the presence of superantigen toxins in 14 of 29 patients with CRSwNP, with SEB and TSST-1 being the most common. Further studies are necessary to correlate the presence of toxin with the pathological changes present in polyp tissue.