Local immunoglobulin production in nasal polyposis is modulated by superantigens

Chronic rhinosinusitis and asthma: novel understanding of the role of IgE 'above atopy'

Chronic rhinosinusitis (CRS) affects more than 10% of the European population and is often associated with asthma. Phenotypes of CRS can be differentiated based on mucosal remodelling and inflammatory patterns. Understanding the role of central mediators, such as interleukin-5, in these different phenotypes may lead to the development of specific therapeutic approaches. The impact of staphylococcal superantigens has been shown to further modify the immune response, contributing to persistent severe disease via the activation of T and B cells and the formation of local IgE. It is clear that these mechanisms are involved in the systemic spread of upper airway disease with resulting asthma comorbidity, when IgE antibodies to staphylococcal enterotoxins are present at measurable levels in serum. Recent findings point to superantigens as possible causal agents in the intrinsic form of severe asthma, and an anti-IgE strategy has shown promising therapeutic potential in nonatopic patients with nasal polyps and asthma. These findings should lead to a clinically relevant endotyping of patients with upper and lower airway disease and to a new understanding of the role of IgE 'above atopy'.

Herpes simplex virus type 1 infection facilitates invasion of Staphylococcus aureus into the nasal mucosa and nasal polyp tissue

BACKGROUND

Staphylococcus aureus (S. aureus) plays an important role in the pathogenesis of severe chronic airway disease, such as nasal polyps. However the mechanisms underlying the initiation of damage and/or invasion of the nasal mucosa by S. aureus are not clearly understood. The aim of this study was to investigate the interaction between S. aureus and herpes simplex virus type 1 (HSV1) in the invasion of the nasal mucosa and nasal polyp tissue.

METHODOLOGY/PRINCIPAL FINDINGS

Inferior turbinate and nasal polyp samples were cultured and infected with either HSV1 alone, S. aureus alone or a combination of both. Both in turbinate mucosa and nasal polyp tissue, HSV1, with or without S. aureus incubation, led to focal infection of outer epithelial cells within 48 h, and loss or damage of the epithelium and invasion of HSV1 into the lamina propria within 72 h. After pre-infection with HSV1 for 24 h or 48 h, S. aureus was able to pass the basement membrane and invade the mucosa. Epithelial damage scores were significantly higher for HSV1 and S. aureus co-infected explants compared with control explants or S. aureus only-infected explants, and significantly correlated with HSV1-invasion scores. The epithelial damage scores of nasal polyp tissues were significantly higher than those of inferior turbinate tissues upon HSV1 infection. Consequently, invasion scores of HSV1 of nasal polyp tissues were significantly higher than those of inferior turbinate mucosa in the HSV1 and co-infection groups, and invasion scores of S. aureus of nasal polyp tissues were significantly higher than those of inferior turbinate tissues in the co-infection group.

CONCLUSIONS/SIGNIFICANCE

HSV1 may lead to a significant damage of the nasal epithelium and consequently may facilitate invasion of S. aureus into the nasal mucosa. Nasal polyp tissue is more susceptible to the invasion of HSV1 and epithelial damage by HSV1 compared with inferior turbinate mucosa.

Specific IgE against Staphylococcus aureus enterotoxins: an independent risk factor for asthma

BACKGROUND

The role of IgE in patients with severe asthma is not fully understood.

OBJECTIVE

We sought to investigate whether IgE to Staphylococcus aureus enterotoxins might be relevant to disease severity in adult asthmatic patients.

METHODS

Specific IgE antibody concentrations in serum against enterotoxins, grass pollen (GP), and house dust mite allergens and total IgE levels were measured in adult cohorts of 69 control subjects, 152 patients with nonsevere asthma, and 166 patients with severe asthma. Severe asthma was defined as inadequately controlled disease despite high-dose inhaled corticosteroids plus at least 2 other controller therapies, including oral steroids.

RESULTS

Enterotoxin IgE positivity was significantly greater in patients with severe asthma (59.6%) than in healthy control subjects (13%, P< .001). Twenty-one percent of patients with severe asthma with enterotoxin IgE were considered nonatopic. Logistic regression analyses demonstrated significantly increased risks for enterotoxin IgE-positive subjects to have any asthma (OR, 7.25; 95% CI, 2.7-19.1) or severe asthma (OR, 11.09; 95% CI, 4.1-29.6) versus enterotoxin IgE-negative subjects. The presence of GP or house dust mite IgE antibodies was not associated with either significantly increased risk for asthma or severity. Oral steroid use and hospitalizations were significantly increased in patients with enterotoxin IgE and nonatopic asthma. GP IgE was associated with a higher FEV(1) percent predicted value, and enterotoxin IgE was associated with a lower FEV(1) percent predicted value.

CONCLUSIONS

Staphylococcal enterotoxin IgE antibodies, but not IgE against inhalant allergens, are risk factors for asthma severity. We hypothesize that the presence of enterotoxin IgE in serum indicates the involvement of staphylococcal superantigens in the pathophysiology of patients with severe asthma.

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.

Glandular mast cells with distinct phenotype are highly elevated in chronic rhinosinusitis with nasal polyps

BACKGROUND

Although chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) is characterized by T(H)2 inflammation, the role of mast cells is poorly understood.

OBJECTIVE

The objective of this study was to investigate the presence, localization, and phenotype of mast cells in patients with CRS.

METHODS

We collected nasal tissue and nasal lavage fluid from patients with CRS and control subjects. We analyzed mRNA for the mast cell proteases tryptase, chymase, and carboxypeptidase A3 by using real-time PCR and measured mast cell protease proteins by using ELISA, immunohistochemistry, and immunofluorescence.

RESULTS

Tryptase mRNA was significantly increased in nasal polyps (NPs) from patients with CRSwNP (P< .001) compared with uncinate tissue from patients with CRS or control subjects. Tryptase protein was also elevated in NPs and in nasal lavage fluids from patients with CRSwNP. Immnohistochemistry showed increased numbers of mast cells in epithelium and glands but not within the lamina propria in NPs. The mast cells detected in the epithelium in NPs were characterized by the expression of tryptase and carboxypeptidase A3 but not chymase. Mast cells expressing all the 3 proteases were abundant within the glandular epithelium of NPs but were not found in normal glandular structures.

CONCLUSIONS

Herein we demonstrated a unique localization of mast cells within the glandular epithelium of NPs and showed that mast cells in NPs have distinct phenotypes that vary by tissue location. Glandular mast cells and the diverse subsets of mast cells detected may contribute to the pathogenesis of CRSwNP.

Local allergic rhinitis: concept, pathophysiology, and management

Local allergic rhinitis (LAR) is a localized nasal allergic response in the absence of systemic atopy characterized by local production of specific IgE (sIgE) antibodies, a T(H)2 pattern of mucosal cell infiltration during natural exposure to aeroallergens, and a positive nasal allergen provocation test response with release of inflammatory mediators (tryptase and eosinophil cationic protein). Although the prevalence remains to be established, a number of patients previously given a diagnosis of nonallergic rhinitis or idiopathic rhinitis are now being classified as having LAR. Culprit allergens responsible include house dust mite, grass and olive pollens, and many others. For the diagnosis of LAR, neither skin prick testing nor determination of the presence of serum sIgE antibodies is useful, and a nasal allergen provocation test is needed to identify the culprit allergen or allergens. In a certain proportion of cases, local sIgE can be detected, and conjunctivitis, asthma, or both can be associated. Whether patients with LAR will have systemic atopy in the future is a matter of debate. Further studies are needed for examine the prevalence of this phenomenon in different areas, to improve the diagnostic methods to better identify these patients, and to develop therapeutic approaches, including the use of immunotherapy.

The who, where, and when of IgE in allergic airway disease

Allergic asthma and allergic rhinitis/conjunctivitis are characterized by a T(H)2-dominated immune response associated with increased serum IgE levels in response to inhaled allergens. Because IgE is a key player in the induction and maintenance of allergic inflammation, it represents a prime target for therapeutic intervention. However, our understanding of IgE biology remains fragmentary. This article puts together our current knowledge on IgE in allergic airway diseases with a special focus on the identity of IgE-secreting cells ("who"), their location ("where"), and the circumstances in which they are induced ("when"). We further consider the therapeutic implications of the insights gained.

The effect of hypoxia and cycloxygenase inhibitors on nasal polyp derived fibroblasts

BACKGROUND AND PURPOSE

The pathogenesis of chronic rhinosinusitis with nasal polyposis is unknown. Chronic inflammation along with local tissue hypoxia may effect polyp's growth. Activation of Cycloxygenases may also be involved. COX-2 up-regulates in response to different stimuli including hypoxia. Its activation is associated with enhanced cell proliferation. Histologically, besides inflammatory cells, increased stromal fibrosis is seen in nasal polyposis. The aims of this study were to test whether hypoxia amplifies nasal polyp fibroblasts proliferation, whether treatment with various COX inhibitors could influence fibroblasts, and whether this effect may be modulated in response to different oxygenation conditions.

MATERIALS AND METHODS

Polyp fibroblasts were incubated under hypoxic or normoxic conditions with or without NSAIDs at different concentrations for 12 or 24 hours. Cell proliferation was quantified using BrdU ELISA. Metabolic activity was evaluated using MTT assay. Cell death was measured using Annexin V staining and FACS scan.

RESULTS

No significant difference was found between proliferation of fibroblasts treated under hypoxia or normoxia. Cells incubated with indomethacin proliferated in a slightly enhanced manner compared with non-treated cells. Celecoxib inhibited fibroblast proliferation (P < .001) but did not influence cell survival. Metabolic activity of cells treated with celecoxib was significantly reduced (P < .003), unlike cells treated with indomethacin or rofecoxib.

CONCLUSION

Hypoxia does not affect fibroblasts proliferation. It may contribute to nasal polyposis pathogenesis in other ways. The anti-proliferative effect of celecoxib may be associated with cell cycle arrest rather than with pro-apoptotic activity. Celecoxib may be considered for treating nasal polyposis.

Activation-induced cytidine deaminase (AID)-associated multigene signature to assess impact of AID in etiology of diseases with inflammatory component

Activation-induced cytidine deaminase (AID) is expressed in B cells within germinal centers and is critically involved in class switch recombination and somatic hypermutation of immunoglobulin loci. Functionally active AID can additionally be detected within ectopic follicular structures developed at sites of chronic inflammation. Furthermore, AID may target non-Ig genes in B- and non-B-cell background. Therefore, AID-associated effects are of increasing interest in disease areas such as allergy, inflammation, autoimmunity, and cancer.Pathway- or disease-relevant multigene signatures have attracted substantial attention for therapeutic target proposal, diagnostic tools, and monitoring of therapy response. To delineate the impact of AID in etiology of multifactorial diseases, we designed the AID-associated 25-gene signature. Chronic rhinosinusitis with nasal polyps was used as an inflammation-driven airway disease model; high levels of IgE have been previously shown to be present within polyp tissue. Expression levels of 16 genes were found to be modulated in polyps including AID, IgG and IgE mature transcripts which reflect AID activity; clustering algorithm revealed an AID-specific gene signature for the disease state with nasal polyp. Complementary, AID-positive ectopic lymphoid structures were detected within polyp tissues by in situ immunostaining. Our data demonstrate the class switch recombination and somatic hypermutation events likely taking place locally in the airways and in addition to the previously highlighted markers and/or targets as IL5 and IgE suggest novel candidate genes to be considered for treatment of nasal polyposis including among others IL13 and CD23. Thus, the algorithm presented herein including the multigene signature approach, analysis of co-regularities and creation of AID-associated functional network gives an integrated view of biological processes and might be further applied to assess role of altered AID expression in etiology of other diseases, in particular, aberrant immunity and cancer.

Pathophysiology of Chronic Rhinosinusitis with Nasal Polyp

Background

Chronic rhinosinusitis (CRS) is a common inflammatory condition of the paranasal sinuses and nasal passages. CRS with nasal polyp (CRSwNP) is a subtype of CRS, and the pathogenesis of CRSwNP remains largely unclear.

Methods

This article reviews the literature regarding the pathophysiology of CRSwNP.

Results

Evidence suggests that altered innate immunity, adaptive immunity, tissue remodeling, and/or effects of microorganisms may play a role in the development of CRSwNP. Aberrant arachidonic acid metabolism may also contribute to the pathogenesis of CRSwNP in patients with aspirin-exacerbated respiratory disease.

Conclusion

There have been significant advances in the understanding pathophysiology of CRSwNP. Additional research is needed to elucidate these mechanisms and to determine their relative importance in the pathogenesis of CRSwNP.

Exacerbation of cigarette smoke-induced pulmonary inflammation by Staphylococcus aureus enterotoxin B in mice

Background

Cigarette smoke (CS) is a major risk factor for the development of COPD. CS exposure is associated with an increased risk of bacterial colonization and respiratory tract infection, because of suppressed antibacterial activities of the immune system and delayed clearance of microbial agents from the lungs. Colonization with Staphylococcus aureus results in release of virulent enterotoxins, with superantigen activity which causes T cell activation.

Objective

To study the effect of Staphylococcus aureus enterotoxin B (SEB) on CS-induced inflammation, in a mouse model of COPD.

Methods

C57/Bl6 mice were exposed to CS or air for 4 weeks (5 cigarettes/exposure, 4x/day, 5 days/week). Endonasal SEB (10 μg/ml) or saline was concomitantly applied starting from week 3, on alternate days. 24 h after the last CS and SEB exposure, mice were sacrificed and bronchoalveolar lavage (BAL) fluid and lung tissue were collected.

Results

Combined exposure to CS and SEB resulted in a raised number of lymphocytes and neutrophils in BAL, as well as increased numbers of CD8⁺ T lymphocytes and granulocytes in lung tissue, compared to sole CS or SEB exposure. Moreover, concomitant CS/SEB exposure induced both IL-13 mRNA expression in lungs and goblet cell hyperplasia in the airway wall. In addition, combined CS/SEB exposure stimulated the formation of dense, organized aggregates of B- and T- lymphocytes in lungs, as well as significant higher CXCL-13 (protein, mRNA) and CCL19 (mRNA) levels in lungs.

Conclusions

Combined CS and SEB exposure aggravates CS-induced inflammation in mice, suggesting that Staphylococcus aureus could influence the pathogenesis of COPD.

Evidence-based management of nasal polyposis by intranasal corticosteroids: from the cause to the clinic

BACKGROUND

Nasal polyposis is an inflammatory disorder involving the mucosa of the nose and paranasal sinuses and affecting approximately 2-4% of the general population.

METHODS

A literature search of Medline and Embase was conducted to obtain an overview of the epidemiology, pathophysiology, and current treatment of nasal polyposis, focusing on evidence-based efficacy of intranasal corticosteroids (INSs) as primary and postoperative therapy. Recent research on INSs in nasal polyp treatment, along with notable historic findings, was reviewed.

RESULTS

Nasal polyps are mostly characterized by eosinophil infiltration, a complex inflammation of nasal mucosa, and possibly production of polyclonal IgE. Current treatment modalities include INSs, oral corticosteroids, and surgery; surgery is generally limited to those with an insufficient response to medical treatment. Because of their effects on eosinophil-dominated inflammation, INSs and oral corticosteroids are the primary medical treatment strategies. The very low (≤1%) systemic bioavailability of newer INSs minimizes the systemic adverse effects seen with oral corticosteroids.

CONCLUSION

Based on randomized, controlled trials, guidelines recommend INSs as first-line therapy for nasal polyps and for care after polypectomy. Clinical data suggest INSs are effective in reducing polyp size and relieving nasal symptoms. INS treatment has also reduced nasal polyp recurrence in patients undergoing functional endoscopic sinus surgery. Treatment with these mainstay options has been found to improve quality of life, which, along with symptom improvement, is a key factor in disease treatment.

Mucosal tissue polyclonal IgE is functional in response to allergen and SEB

BACKGROUND

Staphylococcus aureus may modify airway disease by inducing local formation of polyclonal IgE antibodies (abs), the role of which is unknown.

METHODS

Nasal mucosal tissue and serum was obtained from 12 allergic rhinitis (AR) and 14 nasal polyp (NP) subjects. Skin prick tests were performed, and total and specific IgE abs to inhalant allergens and enterotoxin B were determined in serum and tissue. Tissue fragments were stimulated with anti-IgE, enterotoxin B, or grass and house dust mite allergens in different concentrations for 30 min. RBL SX38 cells were sensitized with NP homogenates containing IgE and stimulated with grass pollen extracts.

RESULTS

In AR patients, degranulation of tissue mast cells upon allergen exposure and presence of specific IgE to inhalant allergens corresponded in almost all cases. Total IgE concentrations in serum and mucosal tissue homogenates highly correlated. In contrast, in NP patients, reactivity of tissue mast cells upon allergen exposure and presence of specific IgE to inhalant allergens or Staphylococcus aureus enterotoxin B corresponded for tissue, but not for serum. Total IgE was significantly higher in tissue compared to serum and failed to show correlation. Tissue IgE to grass pollen was functional to degranulate RBL cells.

CONCLUSION

We here demonstrate that mucosal IgE abs in NP tissue are functional and able to activate mast cells; specific IgE abs in NP tissue can be found independently of their presence in serum. We postulate that superantigen-induced polyclonal IgE in airway disease contributes to chronic inflammation by continuously activating mast cells.

Presence of IL-5 protein and IgE antibodies to staphylococcal enterotoxins in nasal polyps is associated with comorbid asthma

BACKGROUND

Nasal polyps often are associated with asthma. The phenotype of these patients is unknown.

OBJECTIVE

To identify the mucosal factors associated with asthma comorbidity, we analyzed the inflammatory patterns of nasal polyps.

METHODS

Nasal polyps from 70 Belgian patients, 34% with asthma, were analyzed for type of inflammation, T-cell cytokines, and IgE antibodies to Staphylococcus aureus enterotoxins. The same investigations were repeated in 93 Chinese patients with polyps, a group with a low asthma comorbidity rate (8%).

RESULTS

In Belgian patients with polyps, 54% of samples showed eosinophilic inflammation. A classification tree evaluation identified IL-5 as the main positive determinant. Enterotoxin IgE in tissue (37%) was associated with significantly increased total IgE and eosinophil cationic protein concentrations. Expression of enterotoxin IgE, total IgE at greater than 1,442 kU/L, and eosinophil cationic protein at greater than 17,109 μg/L in samples with a total IgE concentration of greater than 246 kU/L significantly predicted asthma (odds ratio, 5.8-13). Only 7.5% of the samples from Chinese patients with polyps showed eosinophilic inflammation. IL-5 was confirmed as a positive determinant of eosinophilic inflammation, and enterotoxin IgE in tissue (17% of patients) was associated with significantly increased total IgE and eosinophil cationic protein concentrations. The expression of IL-5 or total IgE at greater than 790 kU/L in samples with an IL-5 concentration of greater than 194 pg/mL significantly predicted comorbid asthma (odds ratio, 17.2-96).

CONCLUSION

Mucosal inflammation in nasal polyps orchestrated by T(H)2 cytokines and amplified by S aureus enterotoxins is characterized by an increased eosinophilic inflammation and formation of IgE antibodies. This phenotype is associated with comorbid asthma in white and Asian patients with nasal polyps.

Identification of the nasal mucosa as a new target for leptin action

The aim of this study was to examine systemic and local nasal leptin and leptin receptor expression in patients with nasal polyposis and healthy controls.

METHODS AND RESULTS

Serum leptin and soluble leptin receptor levels were examined by enzyme-linked immunosorbent assay (ELISA). The presence of leptin and leptin receptor mRNA was investigated using reverse transcriptase-polymerase chain reaction (RT-PCR), and tissue leptin and leptin receptor protein expression was analysed by immunohistochemistry and ELISA. Serum levels of biologically active leptin were significantly elevated in patients with nasal polyps compared with control subjects. These serum leptin levels were strongly correlated with the levels found in tissue in both study groups, although leptin was not significantly elevated in nasal polyp tissue. Using RT-PCR, we showed that both leptin and its receptors were produced in nasal mucosa. Finally, immunohistochemistry showed that leptin and leptin receptor protein were expressed in several cells of the normal and inflamed nasal mucosa.

CONCLUSIONS

Leptin receptors and their biological ligand leptin are expressed in the nasal mucosa, suggesting a possible role in upper airway immunology.

Rhinosinusitis and asthma: a link for asthma severity

The term rhinosinusitis describes an inflammation of the mucosal lining of the nose and sinuses; however, recent evidence points to the need to differentiate patients with chronic rhinosinusitis without nasal polyps from those with nasal polyps. Asthma comorbidity is especially common in nasal polyp disease and may be associated with aspirin-exacerbated respiratory disease. Of interest, asthma comorbidity is uncommon in some parts of the world but common in others. A further analysis of the inflammatory patterns also revealed that nasal polyps do not represent one single entity; interleukin (IL)-5-positive nasal polyps can be differentiated from IL-5-negative forms by different inflammatory patterns (predominance of eosinophils vs neutrophils). Staphylococcus aureus superantigens frequently colonize IL-5-positive nasal polyps and may amplify the eosinophilic inflammation, induce a polyclonal local IgE formation, and increase the risk of asthma comorbidity. Recent findings in severe asthma patients confirm the role of superantigens in lower airway disease.

T-lymphocyte subpopulations and B7-H1/PD-1 expression in nasal polyposis

T-lymphocyte subpopulations and B7-H1/programmed death-1 (PD-1) positive lymphocytes infiltrating nasal polyps were evaluated in 17 patients with chronic sinusitis with nasal polyposis. Peripheral blood samples were also obtained from the patients and from 11 healthy controls. The CD4(+), CD8(+), CD3(+), CD19(+), B7-H1(+) and PD-1(+) lymphocyte populations were measured using flow cytometry. Lymphocytes from nasal polyps had significantly fewer CD4(+) but significantly more CD8(+) T-cells compared with lymphocytes from the peripheral blood of patients and controls. The percentages of CD19(+)/B7-H1(+) B-cells and of CD3(+)/PD-1(+) T-cells were significantly higher in the nasal polyp samples than in those from peripheral blood of patients and controls. Changes in the T-lymphocyte subpopulations and in the up-regulation of B7-H1 and PD-1 in lymphocytes infiltrating nasal polyps may be involved in the development of the chronic inflammation associated with nasal polyposis.

Oral steroids and doxycycline: two different approaches to treat nasal polyps

BACKGROUND

There is little scientific evidence to support the current practice of using oral glucocorticosteroids and antibiotics to treat patients with chronic rhinosinusitis and nasal polyps.

OBJECTIVE

We evaluated the effects of oral glucocorticoids and doxycycline on symptoms and objective clinical and biological parameters in patients with chronic rhinosinusitis and nasal polyps.

METHODS

In a double-blind, placebo-controlled, multicenter trial, we randomly assigned 47 participants with bilateral nasal polyps to receive either methylprednisolone in decreasing doses (32-8 mg once daily), doxycycline (200 mg on the first day, followed by 100 mg once daily), or placebo for 20 days. Participants were followed for 12 weeks. Patients were assessed for nasal peak inspiratory flow and symptoms and by nasal endoscopy. Markers of inflammation such as eosinophilic cationic protein (ECP), IL-5, myeloperoxidase, matrix metalloproteinase 9, and IgE were measured in nasal secretions. Concentrations of eosinophils, ECP, and soluble IL-5 receptor alpha were measured in peripheral blood samples.

RESULTS

Methylprednisolone and doxycycline each significantly decreased nasal polyp size compared with placebo. The effect of methylprednisolone was maximal at week 3 and lasted until week 8, whereas the effect of doxycycline was moderate but present for 12 weeks. Methylprednisolone significantly reduced levels of ECP, IL-5, and IgE in nasal secretions, whereas doxycycline significantly reduced levels of myeloperoxidase, ECP, and matrix metalloproteinase 9 in nasal secretions.

CONCLUSION

This is the first double-blind, placebo-controlled study to show a significant effect of oral methylprednisolone and doxycycline on size of nasal polyps, nasal symptoms, and mucosal and systemic markers of inflammation.

Evaluation of the presence of B-cell attractant chemokines in chronic rhinosinusitis

BACKGROUND

B-cell responses may play a role in the pathogenesis of nasal polyposis via local IgA and IgE production and activation of eosinophils and mast cells. B-cell attracting chemokines may therefore have relevance in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNPs) Methods: Polyp and inferior turbinate tissues were obtained from CRSwNPs, CRS without NPs (CRSsNPs), and control patients; ELISA and reverse-transcription polymerase chain reaction were used to detect levels of protein and mRNA for selected B-cell chemokines (B-cell attracting chemokine 1 [CXCL13/BCA-1/BLC]), thymus expressed chemokine (CCL25/TECK), mucosae-associated epithelial chemokine (CCL28/MEC), stromal cell-derived factor-1alpha (CXCL12/SDF-1alpha), and selected chemokine receptor genes (CXCR4, CXCR5, and CXCR7).

RESULTS

BCA-1 and SDF-1alpha protein levels were significantly increased in polyp tissue compared with turbinate tissue from CRSsNP patients and controls (p < 0.05 and p < 0.01, respectively). Differences in TECK and MEC were not significant. For mRNA, expression of BCA-1 was significantly up-regulated in polyp tissue and levels correlated with CD20 mRNA expression. Additionally, significant up-regulation of mRNA for the SDF-1alpha receptors CXCR7 and CXCR4 was detected in polyps, while there was a trend for up-regulation of the BCA-1 receptor CXCR5.

CONCLUSION

Elevated levels of the BCA-1 and SDF-1alpha and their receptors may account for an increased presence of B cells and their products, contributing to eosinophilic inflammation in patients with CRSwNP.

Detection of Staphylococcus aureus in nasal tissue with peptide nucleic acid-fluorescence in situ hybridization

BACKGROUND

Staphylococcus aureus (SA) in the nose can be a simple colonizer but also may create an intramucosal reservoir causing recurrent infections or can be a specific immune modulator through superantigenic mechanisms. Because the colonization rate of SA is high, but immunologic reactions causing chronic disease are less frequent, the purpose of this study was to identify the presence of intramucosal SA in healthy subjects and in patients with chronic rhinosinusitis (CRS) and to eventually relate those to the specific immunologic changes due to SA enterotoxins.

METHODS

Nasal tissue was collected in 40 subjects (9 controls, 21 CRS patients with [CRSwNP], and 10 CRS patients without nasal polyps [CRSsNP]). Tissues were homogenized, and mediators and specific IgE-antibodies against SA enterotoxins (SAE-IgE) were measured using the UniCAP system. The tissue was analyzed for the presence of SA by the peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) technique (AdvanDx), and a semiquantitative scoring system was applied. Mann-Whitney exact test was used for statistical analysis.

RESULTS

SA in the mucosal tissue was detected in a higher quantity among CRSwNP subjects with aspirin exacerbated respiratory disease (AERD) versus controls and CRSsNP (p=0.03). Among CRSwNP patients, Th2 markers (eosinophil cationic protein, p=0.006, and total IgE, p=0.004) were increased related to the SAE-IgE status but not related to the presence of SA in the tissue.

CONCLUSION

This study describes the detection of SA within nasal tissue using the PNA-FISH technique. The presence of SA in the submucosa did not correlate with the amplification of the Th2-related inflammation typically found in CRSwNP patients, but this reaction is dependent on the formation of SAE-IgE within mucosal tissue. We also show, for the first time, that submucosal SA is a prevalent finding in CRSwNP patients with AERD.

The role of allergy in rhinosinusitis

PURPOSE OF REVIEW

To examine the current evidence for IgE and non-IgE-mediated hypersensitivity mechanisms in acute and chronic rhinosinusitis.

RECENT FINDINGS

Epidemiological studies show that classical IgE-mediated allergy is present in a proportion of acute rhinosinusitis patients. There is conflicting evidence whether the prevalence of IgE-mediated allergy is greater in chronic rhinosinusitis than in individuals without chronic rhinosinusitis. Despite presence of classical IgE-mediated allergy, based on elevated allergen-specific serum IgE levels and positive skin prick tests, currently there is no direct evidence for allergy as a major cause of sinonasal inflammation in chronic rhinosinusitis. There is increasing evidence that non-IgE-mediated fungal hypersensitivity and nonallergic IgE-associated inflammation may contribute to the pathogenesis in some forms of chronic rhinosinusitis, including allergic fungal sinusitis. Specific IgE to bacterial superantigens may also be elevated in nasal polyps and modulate eosinophilic inflammation. Recent insights into mucosal immune mechanisms yield intriguing prospects for the roles of mucosal IgE, mast cells and non-IgE-mediated hypersensitivity mechanisms that require further examination in rhinosinusitis.

SUMMARY

There is a need for further immunological studies of the systemic and mucosal cellular and humoral mechanisms in well defined patient groups and controls to better understand the role of IgE and non-IgE-mediated hypersensitivity mechanisms and nonhypersensitivity functions of IgE in rhinosinusitis.

Intrinsic asthma: not so different from allergic asthma but driven by superantigens?

The mechanisms of intrinsic or non-allergic asthma remain uncertain as allergens have no obvious role in driving the inflammatory process in the airways. However, IgE synthesis occurs in the airways, despite negative skin prick tests and serum-specific IgE. Furthermore, the inflammatory process in the airways is very similar between allergic and non-allergic asthma, with increased T-helper type 2 (Th2) cells, mast cell activation and infiltration of eosinophils. This pattern of inflammation is associated with a similar expression of inflammatory mediators, including Th2 cytokines and eosinophilotactic chemokines. There is increasing evidence that microbial superantigens, particularly Staphylococcal enterotoxins are important in amplifying inflammation in atopic dermatitis and chronic rhinosinusitis, in atopic and non-atopic patients. Superantigens may also be important in intrinsic asthma as airway epithelial cells may be colonized by Staphylococci and other superantigen-producing microbes. Superantigens produced locally in the airways may lead to class switching of local B cells, resulting in polyclonal IgE production in the airways and also specific IgE against the superantigen (which functions as a 'superallergen'). This leads to sensitization of mast cells, which can be activated by the usual asthma triggers, such as exercise. Superantigens also cause clonal expansion of T cells, resulting in increased Th2 cells and CD8(+) cells, while suppressing regulatory T cells. Superantigens may also reduce responsiveness to corticosteroids, resulting in more severe asthma. Finally, cytotoxic autoantibodies may also be implicated as IgG antibodies directed against epithelial proteins, such as cytokeratin-18, have been detected in intrinsic asthma, possibly as a result of epithelial damage and this may make epithelial cells more susceptible to microbial colonization. The therapeutic implications are that antibodies against local IgE and microbial superantigens or antibiotic therapy to eradicate the relevant superantigen-producing microorganisms may improve the efficacy of conventional therapy with corticosteroids.

Important research questions in allergy and related diseases: 3-chronic rhinosinusitis and nasal polyposis - a GALEN study

Chronic rhinosinusitis is one of the most common health care challenges, with significant direct medical costs and severe impact on lower airway disease and general health outcomes. The diagnosis of chronic rhinosinusitis (CRS) currently is based on clinical signs, nasal endoscopy and CT scanning, and therapeutic recommendations are focussing on 2 classes of drugs, corticosteroids and antibiotics. A better understanding of the pathogenesis and the factors amplifying mucosal inflammation therefore seems to be crucial for the development of new diagnostic and therapeutic tools. In an effort to extend knowledge in this area, the WP 2.7.2 of the GA(2)LEN network of excellence currently collects data and samples of 1000 CRS patients and 250 control subjects. The main objective of this project is to characterize patients with upper airway disease on the basis of clinical parameters, infectious agents, inflammatory mechanisms and remodeling processes. This collaborative research will result in better knowledge on patient phenotypes, pathomechanisms, and subtypes in chronic rhinosinusitis. This review summarizes the state of the art on chronic rhinosinusitis and nasal polyposis in different aspects of the disease. It defines potential gaps in the current research, and points to future research perspectives and targets.

Allergic fungal sinusitis: pathophysiology, diagnosis and management

Allergic fungal sinusitis (AFS) is a noninvasive form of fungal rhinosinusitis with an incidence of between 6 and 9% of all rhinosinusitis requiring surgery. Regional variation in incidence has been reported, with the southern and southwestern US particularly endemic. Patients with AFS commonly present with chronic rhinosinusitis with nasal polyps, inhalant atopy, elevated total serum immunoglobulin E (IgE), and sinus-obstructing inspissates of a characteristic extramucosal 'peanut buttery' visco-elastic eosinophil-rich material called 'allergic mucin' that contains sparse numbers of fungal hyphae. Sinus CT is always abnormal, showing findings of chronic rhinosinusitis that often include central areas of increased contrast ('hyperattenuation') within abnormal paranasal sinuses that represent the presence of fungal-containing allergic mucin. AFS has been found to be analogous in several ways to allergic bronchopulmonary aspergillosis (ABPA). Both are chronic inflammatory respiratory tract disorders that are driven by hypersensitivity responses to the presence of small numbers of extramucosal fungi found growing within airway-impacting allergic mucin. AFS allergic mucin typically cultures positive for either dematiaceous fungi such as Bipolaris spicifera or Curvularia lunata, or Aspergillus species such as A. fumigatus, A. flavus or A. niger. As with ABPA, patients have type I immediate hypersensitivity to the etiologic mold in AFS. Further, both AFS and ABPA have been found to have association with specific class II major histocompatibility alleles. Proper diagnosis of AFS and differentiation from the other forms of both noninvasive and invasive fungal rhinosinusitis requires strict adherence to published diagnostic criteria. Medical treatment of AFS has been modeled to an extent after treatment approaches for ABPA that includes the use of postoperative oral corticosteroids and aggressive antiallergic inflammation therapy. The use of follow-up measurements of total serum IgE during treatment of both AFS and ABPA patients can help to monitor disease activity. Future AFS research will lead to further insights into pathogenesis, improved treatments, and ultimately decreases in surgical recurrence rates for this highly recurrent hypertrophic rhinosinusitis disorder.

Perspectives on the etiology of chronic rhinosinusitis: an immune barrier hypothesis

BACKGROUND

Chronic rhinosinusitis (CRS) has been defined as persistent symptomatic inflammation of the nasal and sinus mucosa resulting from the interaction of multiple host and environmental factors. Recent studies have implicated Alternaria fungi or toxigenic Staphylococcus aureus as critical agents in CRS pathogenesis. The emphasis on environmental agents in CRS etiology has focused interest toward elimination of those agents as the prime mechanism of therapy. This viewpoint is in marked contrast to the current perspective on some other chronic inflammatory epithelial disorders that afflict the skin, lungs, and gut, wherein host factors are believed to predispose to disease expression in the presence of ubiquitous environmental agents.

METHODS

The current review evaluates CRS etiology from this perspective and considers that CRS develops, in part, as an outcome of a dysfunctional host response. Specifically, evidence from our laboratory and others will be reviewed indicating that CRS is associated with a failure of the mechanical and immunologic barriers across the nasal mucosa. The hypothesis would further propose that genetic and epigenetic variation predisposes susceptible individuals to barrier failure in the presence of environmental stress leading to CRS.

RESULTS

From this unifying perspective, bacteria and fungi are seen as disease modifiers rather than primary etiologic agents.

CONCLUSION

The goal is to place concepts of CRS pathophysiology in a framework consistent with a current understanding of chronic inflammation in general and epithelial disease in particular.

Evidence of a role for B cell-activating factor of the TNF family in the pathogenesis of chronic rhinosinusitis with nasal polyps

BACKGROUND

The polypoid form of chronic rhinosinusitis (chronic rhinosinusitis with nasal polyps [CRSwNP]) is a highly prevalent disease that often requires surgical intervention for treatment. Nasal polyps contain large quantities of B lymphocytes and immunoglobulin as well as eosinophils.

OBJECTIVES

The objective of this study was to investigate the expression of B cell-activating factor of the TNF family (BAFF), an important regulator of class-switch recombination and immunoglobulin production, in patients with chronic rhinosinusitis (CRS).

METHODS

We collected nasal tissue and nasal lavage fluid from patients with CRS and control subjects. We assayed mRNA for BAFF and B-lymphocyte markers, CD20 and transmembrane activator and calcium-modulator and cyclophilin ligand interactor, by using real-time PCR, and assayed BAFF protein by using ELISA and immunohistochemistry.

RESULTS

BAFF mRNA was significantly increased in nasal polyps from patients with CRSwNP (P < .001) compared with inferior turbinate tissue from patients with CRS or healthy subjects. BAFF protein was also elevated in polypoid tissue and nasal lavage from patients with CRSwNP. Immunohistochemistry showed considerable BAFF staining in mucosal epithelial cells in nasal polyps along with unidentified cells in the lamina propria. Expression of mRNA for BAFF in sinonasal tissue was significantly correlated with CD20 and transmembrane activator and CAML interactor in sinus tissue. IgA, an immunoglobulin isotype known to activate eosinophils, was also significantly elevated in the polypoid tissue.

CONCLUSION

Overproduction of BAFF in nasal polyps may contribute to the pathogenesis of CRSwNP via the local induction of IgA and activation of eosinophils.