The Global Allergy and Asthma European Network (GALEN rhinosinusitis cohort: a large European cross-sectional study of chronic rhinosinusitis patients with and without nasal polyps

BACKGROUND

Chronic rhinosinusitis (CRS) is a common yet under-recognised chronic inflammatory disease of the nose and paranasal sinuses that is classified according to the presence (CRSwNP) or absence (CRSsNP) of nasal polyps.

METHODS

This paper reports the methodology and descriptive results of the Global Allergy and Asthma European Network (GALEN) rhinosinusitis cohort. We established a large CRS cohort within the GALEN consortium (European FP6 research initiative) to identify inflammatory endotypes, the natural disease course, and its impact on health-related quality of life (HRQoL). Detailed information on the impact of CRS on HRQoL, comorbidity incidence, objective disease measures, and medical and surgical treatments were collected.

RESULTS

This multicentre cross-sectional case-control study recruited 935 adults (869 eligible for analysis: 237 CRSsNP; 445 CRSwNP; 187 controls [reference group]). Comorbidities such as asthma, allergy, eczema, food allergy, urticaria, and chronic obstructive pulmonary disease were significantly more frequent in CRS patients. Nasal corticosteroids, antibiotics, and oral corticosteroids were the most common treatments. Significantly more CRSwNP patients reported previous sinonasal surgery.

CONCLUSIONS

This study provides detailed information that facilitates studying CRS and its main phenotypes. However, patient distribution of this study does not necessarily reflect disease distribution in the general population.

Th2 cytokines orchestrate the secretion of MUC5AC and MUC5B in IL-5-positive chronic rhinosinusitis with nasal polyps

BACKGROUND

Mucin over-secretion is a significant characteristic of chronic rhinosinusitis with nasal polyps (CRSwNP). This study aimed to investigate the relationship between Th2 cytokines and MUC5AC or MUC5B, and the mechanism of mucin over-secretion in the type-2 inflammatory endotype of CRSwNP.

METHODS

Main Th-cell cytokines, associated mediators, and mucins were determined in the homogenates of nasal polyp samples from 21 CRSwNP patients and inferior turbinate samples from 8 controls, by ELISA or UniCAP system. Secretion of MUC5AC and MUC5B was measured in the supernatants of IL-5, IL-4, or IL-13 primed nasal polyp fragments. Co-localization of MUC5AC, MUC5B, and IL-4 receptor α (IL-4Rα) in CRSwNP and controls was evaluated by immunohistochemistry. Gene expression of IL-4Rα in the samples was measured by real-time reverse transcription-polymerase chain reaction.

RESULTS

Baseline protein levels of the Th2-cytokines IL-4, IL-5, and IL-13, and mucins MUC5AC and MUC5B were significantly higher in the IL-5(+) CRSwNP group, compared to control and IL-5(-) CRSwNP groups. MUC5AC and MUC5B secretions were significantly increased in IL-4- or IL-13-primed, but not IL-5-primed fragments of nasal polyps. Immuno-stained serial sections demonstrated that IL-4Rα was widely expressed in the epithelium and submucosal glands in control and nasal polyp tissues. Gene expression of IL-4Rα was elevated in nasal polyp tissues, specifically in the IL-5(+) CRSwNP group.

CONCLUSIONS

In type-2 inflammatory nasal polyps, characterized by the tissue expression of IL-5, MUC5AC and MUC5B are overexpressed. Both IL-4 and IL-13 may upregulate mucin expression via IL-4Rα, which is also overexpressed in IL-5(+) CRSwNP.

In chronic spontaneous urticaria, IgE against staphylococcal enterotoxins is common and functional

BACKGROUND

Chronic spontaneous urticaria (CSU) is a frequent disorder with recurrent itchy wheals and/or angioedema. Despite the known effectiveness of omalizumab therapy, the relevant IgE antigens are largely unknown. Recently, increased rates of elevated levels of IgE towards Staphylococcus aureus enterotoxins (SEs) were described in CSU.

AIM

To assess the prevalence and functional relevance of IgE to SEs in CSU.

METHOD

We investigated serum levels of IgE against SEs in 49 CSU patients and in 15 CSU patients additional specific IgE to SE components and basophil histamine release (BHR). Sera of 15 healthy controls (HCs) served as control group.

RESULTS

Twenty-five (51%) of the CSU patients had detectable levels of SE-IgE as compared to 5 (33%) of HCs. Specific IgE to one of the SEs, Staphylococcus enterotoxin B (SEB), was present in 5 (33%) of 15 randomly selected CSU patients vs 3 (20%) of HC. Total IgE serum levels in CSU patients were significantly correlated with SE-IgE (r = .52, P < .001) and SEB-IgE (r = .54, P = .04) serum concentrations. Interestingly, SEB-IgE levels were strongly correlated with disease activity (UASday) in CSU patients (r = .657, P = .01). Furthermore, BHR in response to SEB was significantly higher in basophils loaded with the serum of CSU patients compared to HC (P < .05) and was clinically correlated with duration of disease (r > .51, P < .05).

DISCUSSION

IgE against SEs may contribute to the pathogenesis of CSU in a subpopulation of patients. Its role and relevance in the pathophysiology of CSU need to be further analysed.

FcεRI expression and IgE binding by dendritic cells and basophils in allergic rhinitis and upon allergen immunotherapy

BACKGROUND

In humans, both basophils and dendritic cells (DCs) express the high-affinity IgE receptor (FcεRI).

OBJECTIVE

To gain more insight into the relation between serum IgE levels and FcεRI expression and IgE binding by DCs and basophils in house dust mite (HDM) allergy and during subcutaneous immunotherapy (SCIT).

METHODS

We measured FcεRI, IgE and HDM allergen on DCs (conventional type 2 DCs, cDC2s; plasmacytoid dendritic cells, pDCs) and basophils by flow cytometry in 22 non-allergic vs 52 allergic subjects and upon HDM SCIT in 28 allergic subjects. IgE levels were measured in serum.

RESULTS

Serum IgE correlated differentially with FcεRI expression and IgE binding depending on cell type and allergic status. In non-allergic subjects, FcεRI/IgE surface densities increased with serum IgE to a significantly stronger degree on basophils compared to cDC2s. By contrast, in allergic subjects FcεRI/IgE surface densities increased with serum IgE to a slightly stronger degree on cDC2s compared to basophils. In addition, the data set suggests sequential loading of IgE onto FcεRI expressed by these cells (basophils>cDC2s>pDCs). Finally, HDM SCIT induced a temporary increase in serum IgE, which was paralleled by a peak in FcεRI and IgE on DCs, but not on basophils.

CONCLUSIONS & CLINICAL RELEVANCE

This study provides a comprehensive insight into the relation between serum IgE and FcεRI/IgE on basophils and DC subsets. The novel finding that HDM SCIT induces a temporary increase in FcεRI expression on DCs, but not on basophils, can be an incentive for future research on the potential tolerogenic role of IgE/FcεRI signalling in DCs in the setting of allergen immunotherapy.

The effect of systemic treatments on periostin expression reflects their interference with the eosinophilic inflammation in chronic rhinosinusitis with nasal polyps

BACKGROUND

Periostin is a recently discovered biomarker for eosinophilic inflammation. Chronic rhinosinusitis with nasal polyps is a T-helper 2-skewed chronic inflammatory airway disease. Medical treatments aim to relieve symptoms and maintain clinical control by interfering with the inflammatory cascade. The effect on nasal and serum periostin levels is however yet unknown. We aimed to evaluate the effect of omalizumab, mepolizumab, methylprednisolone and doxycycline on nasal and systemic periostin expression.

METHODS

This study is based on 3 previously published trials. Nasal and systemic periostin were assessed in CRSwNP patients, randomly assigned to receive doxycycline (n=14), methylprednisolone (n=14), mepolizumab (n=20) or omalizumab (n=15). There was a control group for each treatment scheme. Doxycycline (200 mg on the first day, followed by 100 mg once daily) and methylprednisolone (32-8 mg once daily) were administered during 20 days; mepolizumab was injected at baseline and at 4 weeks. Omalizumab was injected every 2 or 4 weeks, following the official drug leaflet.

RESULTS

Methylprednisolone and omalizumab significantly reduced serum periostin levels at 4 and 8 weeks, respectively, after the start of the treatment. The effect of methylprednisolone was transient. Nasal periostin levels decreased significantly after 8 weeks of treatment with mepolizumab. The periostin expression is in accordance with the previously reported effect on the eosinophilic inflammation and clinical outcome.

CONCLUSION

All treatment options distinctly influence periostin expression, reflecting the interference with the local or systemic eosinophilic inflammatory cascade.

[Pathophysiology of chronic rhinosinusitis, pharmaceutical therapy options]

Research in immunology has brought great progress in knowledge of inflammatory processes in the last 2 decades, which also has an impact on the upper airways. Our understanding of the pathophysiology of chronic rhinosinusitis developed from a rather mechanistic point of view with a focus on narrow clefts and mucociliary clearance to the appreciation of a complex network of immunological pathways forming the basis of disease. We today differentiate various forms of inflammation, we start to understand complex immune-regulatory networks and the reasons for their failure, and have already developed innovative approaches for therapy for the most severely ill subjects. Due to this new knowledge in inflammation and remodeling processes within mucosal tissue, specifically on the key driving factors, new diagnostic tools and therapeutic approaches for chronic rhinosinusitis have developed; the differentiation of endotypes based on pathophysiological principles will be crucial for the use of innovative therapies, mostly humanized monoclonal antibodies. Several hundred of those antibodies are currently developed for various indications and will impact our speciality as well as pneumology to a great extent.

The adjuvant-like activity of staphylococcal enterotoxin B in a murine asthma model is independent of IL-1R signaling

BACKGROUND

Staphylococcal enterotoxin B (SEB) is a superantigen known to be a modulator of chronic airway inflammation in mice and humans, yet little is known about the mechanisms that regulate its interaction with the innate immune system. We investigated this mechanism in a murine model of allergic airway inflammation induced by OVA (ovalbumin) in the presence of SEB.

METHODS

Superantigen-induced allergic inflammation was studied in IL-1R knockout (KO) mice exposed to OVA+SEB. Multicolor flow cytometry was used to analyze the inflammatory cell profile in airways and lymph nodes. Production of IL-4, IL-5, IL-10, and IL-13 in lymph nodes was assessed by Luminex technology.

RESULTS

In wild-type mice, endonasal instillation of OVA+SEB induced a pulmonary inflammation, characterized by an increase in the number of eosinophils, T cells, and dendritic cells and in the production of Th2 cytokines and OVA-specific IgE. In IL-1R KO mice exposed to OVA+SEB, attraction of CD4+ cells and production of Th2 cytokines were reduced. However, knocking out IL-1R did not affect any of the features of allergic airway inflammation, such as bronchial eosinophilia, OVA-specific IgE production and goblet cell metaplasia.

CONCLUSION

We provide new insights into the mechanisms of airways allergy development in the presence of bacterial superantigen. The asthma features induced by OVA+SEB, such as bronchial eosinophilia, goblet cell proliferation, production of OVA-specific IgE and increase in inflammatory dendritic cells, are IL-1R independent. Yet, IL-1R signaling is crucial for CD4 cell accumulation and Th2 cytokine production.

Inflammation and remodelling patterns in early stage chronic rhinosinusitis

BACKGROUND

A distinct set of inflammatory and remodelling factors have been found elevated in chronic rhinosinusitis.

OBJECTIVE

The investigation of their expression in early stage disease may reveal early events in this common disease.

METHODS

Sinonasal mucosal samples from nine patients with early stage CRSsNP were taken from the inferior and middle turbinates, the uncinate process, maxillary sinus, anterior ethmoid, bulla ethmoidalis and the posterior ethmoid and measured for TGF-beta 1 and it's receptors, MPO protein as well as pro-inflammatory cytokines (TNF-alpha and IL-1beta) and the Th1 cell signature (IFN-gamma and T-bet). As outcome parameter for TGF-beta signalling collagen deposition was analysed. Inferior turbinates from patients undergoing (rhino-) septoplasty were collected as controls.

RESULTS

TGF-beta 1 protein concentrations were significantly increased in the maxillary sinuses (P = 0.006), the uncinate process (P = 0.01), the anterior ethmoid including the bulla ethmoidalis (P = 0.005) and the posterior ethmoid (P = 0.037) when compared to the inferior and middle turbinates. Collagen deposition was significantly increased in the maxillary sinus when compared to the inferior turbinates (P = 0.008). In contrast, mRNA for TGF-beta receptors, Th1 related markers (IFN-gamma and T-bet), pro-inflammatory cytokines (IL-1 beta and TNF-alpha), and MPO protein as neutrophil marker were expressed at all locations but showed no significant differences between the various locations. TGF-beta 1 mRNA expression in inferior turbinates of CRSsNP was significantly higher when compared to inferior turbinates of controls (P = 0.017). The pro-inflammatory cytokines and Th1-related cytokines did not show an upregulation in inferior turbinates of CRSsNP when compared to controls.

CONCLUSIONS

In early stage chronic sinus disease, TGF-beta protein is expressed in significantly higher concentrations within the paranasal sinuses when compared to turbinates, whereas pro-inflammatory, neutrophilic and Th1 markers did not show any difference. These findings suggest that TGF-beta plays a central role in the initiation of CRSsNP, and represents a major target for further research and future intervention.

Local free light chain expression is increased in chronic rhinosinusitis with nasal polyps

BACKGROUND

Free light chain (FLC) concentrations are demonstrated to be increased in different inflammatory disorders and are proposed to mediate mast cell-dependent immune responses. A role for mast cells is suggested in chronic rhinosinusitis with nasal polyposis (CRSwNP), which is characterized by a local Th2 inflammatory response. However, clear mast cell-activating factors are not always apparent. In this study, the presence of FLCs in CRS patients with or without nasal polyps (CRSw/sNP) was investigated and the effect of different treatments on FLC expression was analyzed.

METHODS

Nasal tissue, nasal secretion, and serum of control patients, patients with CRSwNP, and CRSsNP were analyzed for the presence of kappa and lambda FLC. The expression of FLCs in nasal polyp tissue was investigated using immunohistochemistry. In addition, FLC was measured in serum and nasal secretion of nasal polyp patients treated with methylprednisolone, doxycycline, anti-IL-5, or placebo.

RESULTS

Free light chain concentrations were increased in nasal secretion and mucosal tissue homogenates in patients with chronic rhinosinusitis, and this effect was most prominent in CRSwNP patients. Immunohistochemical analysis confirmed the increased FLC concentrations in nasal polyp tissue. In CRSwNP patients, treatment with methylprednisolone or anti-IL-5 resulted in the reduction in systemic or local FLC concentrations, respectively.

CONCLUSION

The presence of FLC in CRSwNP and CRSsNP suggests a possible role in mediating the local immune reaction in the paranasal cavities. Furthermore, the decrease in local FLCs after treatment with anti-IL-5 presumes that IL-5 creates an environment that favors FLC production.

Adaptive immune responses in Staphylococcus aureus biofilm-associated chronic rhinosinusitis

BACKGROUND

The etiopathogenesis of chronic rhinosinusitis (CRS) is currently an area of intense debate. Recently, biofilms have been proposed as a potential environmental trigger in this disease. In particular, Staphylococcus aureus biofilms appear to be a predictor of severe disease recalcitrant to current treatment paradigms. However, direct causal links between biofilms and host immune activation are currently lacking. This study aimed to document both the adaptive immune responses that characterize S. aureus biofilm-associated CRS and the relative contributions of staphylococcal superantigens and S. aureus biofilms in the inflammatory make-up of this disease.

METHODS

A total of 53 disease subjects and 15 controls were recruited. Sinonasal mucosa was collected for the determination of S. aureus and Haemophilus influenzae biofilms and presence of total and superantigen-specific IgE and for the measurement of cytokines that characterize the T-helper pathways.

RESULTS

Staphylococcus aureus biofilms and superantigens are significantly associated in CRS patients, suggesting the biofilm may be a nidus for superantigen-eluting bacteria. The presence of S. aureus biofilms is associated with eosinophilic inflammation, across the spectrum of CRS, on the back of a T-helper(2) skewing of the host's adaptive immune response (elevated Eosinophilic Cationic Protein and IL-5). This can be distinguished from the superantigenic effect resulting in the induction of IgE.

CONCLUSION

This study provides novel evidence of a link between S. aureus biofilms and skewing of the T-cell response toward the T-helper(2) pathway that is independent of superantigen activities. Further research is required to confirm the cause-effect relationship of this association.

Alternatively activated macrophages and impaired phagocytosis of S. aureus in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by biased Th2 inflammation and CRS without nasal polyps (CRSsNP) by a Th1 immune response. Colonization by Staphylococcus aureus is increased in CRSwNP. We aimed to determine macrophage phenotypes in nasal mucosa of CRSwNP and CRSsNP and to examine phagocytosis of S. aureus in these pathologies.

METHODS

Macrophage phenotyping was performed by immunohistochemical staining on nasal mucosa sections from 28 patients; in addition flow cytometry analysis was performed. Tissue homogenate protein levels of IFN-γ, IL-5, IL-6, IL-1β, TGF-β, eosinophil cationic protein (ECP) and total IgE were analyzed and correlated with macrophage subtypes. Phagocytosis of S. aureus was analyzed by flow cytometry. Survival of S. aureus in Thp1 cells in the presence of polarizing cytokines was studied in vitro.

RESULTS

  By immunohistochemical analysis more M2 macrophages were present in CRSwNP than in CRSsNP. This also was positively correlated with increased levels of IL-5, ECP and locally produced IgE and decreased levels of IL-6, IL-1β and IFN-γ. FACS analysis of dissociated nasal tissue confirmed the presence of increased numbers of M2 macrophages (CD206(+) HLADR(+) CD14(+) CD11c(+) CD20(-) ) in CRSwNP as compared to controls, while the number of M1 macrophages (CD206(-) HLADR(+) CD14(+) CD11c(int) CD16(-) CD20(-) ) was not different. Phagocytosis of S. aureus by human tissue derived macrophages was reduced in CRSwNP as compared to macrophages from the control inferior turbinates.

CONCLUSIONS

  Decreased phagocytosis of S. aureus and an M2 activation phenotype in CRSwNP could potentially contribute to persistence of chronic inflammation in CRSwNP.

T cell inflammatory response, Foxp3 and TNFRS18-L regulation of peripheral blood mononuclear cells from patients with nasal polyps-asthma after staphylococcal superantigen stimulation

BACKGROUND

Staphylococcal superantigens may modulate airway inflammatory disease.

OBJECTIVE

We assessed the effect of Staphylococcus aureus enterotoxin B (SEB) on T cell activation in patients with nasal polyps and asthma, and its possible link to aspirin hypersensitivity.

METHODS

Leucocytes were isolated from five healthy subjects (controls), five asthmatics with nasal polyps without (NP-ATA) and five with aspirin-induced asthma (NP-AIA). Cells were incubated with increasing concentrations of SEB for 4 and 18 h. Release of T(H)1/T(H)2 cytokines was assessed by Cytometric Bead-Array. Foxp3 and TNFRS18-L expression were analysed by qPCR and flow cytometry.

RESULTS

After 4 and 18 h, SEB significantly increased IFN-gamma, IL-4, TNF-alpha, IL-5 and IL-2 concentrations in supernatants of both NP polyp groups compared with controls. Baseline Foxp3 was significantly decreased in both NP-asthma groups. Incubation with SEB for 4 h induced a limited up-regulation of Foxp3 in NP-AIA patients, which was switched off consecutively. Foxp3 was significantly up-regulated in the control group after 18 h, but not in the NP-asthmatic groups. In parallel, TNFRS18-L mRNA significantly increased after 18 h in the NP-asthma groups compared with control subjects. This molecule was highly expressed in CD11c(+)CD14(+) cells and its levels increased after 18 and 24 h culture in the NP-asthma patients.

CONCLUSION

SEB induces both T(H)1 and T(H)2 pro-inflammatory responses in patients with nasal polyps and asthma regardless of the presence of aspirin hypersensitivity. The nature of this response may be linked to a basal deficiency of Foxp3 observed in the NP-asthmatic patients and/or to the up-regulation of TNFRS18-L on monocytes/dendritic cell precursors.

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.

Inflammatory profiles in nasal mucosa of patients with persistent vs intermittent allergic rhinitis

BACKGROUND

To date there is little information on the inflammatory profiles of patients suffering from persistent (PER) and intermittent allergic rhinitis (IAR). Also, it is not clear whether differences exist in eosinophilic inflammation and/or T-helper cell sub-populations and their markers. The aim of this study was to primarily evaluate the inflammatory profiles of patients with moderate/severe PER and IAR.

METHODS

Inferior nasal turbinate tissue was obtained from 12 PER, 12 IAR and 12 nonallergic nonrhinitic (control) patients, and symptoms (visual analogue scales, VAS) and impairment of life was monitored. All tissues were assessed for eosinophil and mast cell numbers by immunohistochemistry; IL-5, ECP and IgE concentrations by immunoassay; mRNA for transcription factors GATA-3, T-bet, FOXP3 and RORc by quantitative real-time polymerase chain reaction; and IgE-induced release of LTC(4)/D(4)/E(4) and PGD(2)in vitro.

RESULTS

Eosinophils and mast cells were significantly increased in patients with PER and patients with IAR compared to control subjects; by patients with PER demonstrating even significantly greater increase of both cell types than patients with IAR. Similarly, ECP IL-5, GATA-3 mRNA expression and IgE-induced release of LTC4/D(4)/E(4) and PGD(2) from mast cells were significantly increased in patients with PER compared to patients with IAR. In contrast, the expression of T-bet, FOXP3 or RORc mRNA was not significantly different in the PER, IAR or control patients.

CONCLUSION

The findings from the present study suggest that PER is characterized by a significantly greater eosinophilic and predominantly Th2 cell-mediated nasal inflammatory profile compared to IAR.

CRTH2 mediates the activation of human Th2 cells in response to PGD(2) released from IgE/anti-IgE treated nasal polyp tissue

BACKGROUND

Mast cells release mediators upon stimulation that contribute to the pathogenesis of chronic airway disease, including the recruitment and activation of Th2 lymphocytes. The objective was to determine the involvement of prostaglandin D(2) (PGD(2)) and its receptors in the chemotaxis of Th2 cells, using nasal polyp tissue.

METHODS

Tissue explants from ten patients with nasal polyposis were incubated with RPMI alone or RPMI containing IgE/anti-IgE for 30 min. Some samples were treated with diclofenac to inhibit the production of PGD(2). Supernatants were assayed for PGD(2) content and for their ability to promote human Th2 cell chemotaxis in the presence and absence of a CRTH2 antagonist. Transcript levels of D protanoid receptor type 1 (DP(1)), chemoattractant receptor-homologous receptor expressed on Th2 cells (CRTH2) and PGD(2) synthase were analysed by real time PCR.

RESULTS

Increased release of PGD(2) by nasal polyp tissue treated with IgE/anti-IgE was significantly inhibited by preincubation of the tissue with diclofenac. Transcript levels of PGD(2) synthase, DP(1) and CRTH2 receptors increased after stimulation with IgE/anti-IgE. Supernatants from IgE/anti-IgE-stimulated nasal polyp tissue caused significantly increased chemotaxis of Th2 cells. The levels of PGD(2) produced and the degree of Th2 cell chemotaxis were highly correlated. Diclofenac inhibited the production of Th2 cell chemotactic activity, and the chemotactic effect of the supernatant on Th2 cells was inhibited by the CRTH2 antagonist ramatroban.

CONCLUSION

These data suggest that in immunologically activated nasal polyp tissue, PGD(2) produced by mast cells promotes the migration of Th2 cells through a CRTH2 dependent mechanism.

Differential expression of the interleukin 5 receptor alpha isoforms in blood and tissue eosinophils of nasal polyp patients

BACKGROUND

Given the key role of interleukin-5 (IL-5) in eosinophil function, we investigated the regulated expression of the membrane-anchored (TM-IL-5Ralpha) isoform, or a secreted (SOL IL-5Ralpha) isoform, on both protein and transcript level in vitro and in vivo.

METHODS

A real-time PCR, FACS and ELISA were established to determine IL-5Ralpha isoform expression in peripheral blood and nasal tissue from control subjects and nasal polyp (NP) patients with or without asthma. Human peripheral blood eosinophils were incubated with IL-5 and were analyzed for SOL-IL-5Ralpha and TM-IL-5Ralpha mRNA and protein levels in comparison with CD-69 expression.

RESULTS

SOL-IL-5Ralpha and TM-IL-5Ralpha mRNA and protein expression was significantly increased in NP vs controls. In polyp tissue, SOL-IL-5Ralpha expression correlated to disease severity and eosinophils counts, whereas TM-IL-5Ralpha levels were inversely correlated to eosinophils counts and SOL-IL-5Ralpha expression. FACS analysis revealed increased CD-69 and decreased TM-IL-5Ralpha expression in NP tissue eosinophils vs blood eosinophils. Incubation of blood eosinophils with IL-5 caused up-regulation of CD-69 and down-regulation of TM-IL-5Ralpha after 2 and 24 h.

CONCLUSION

The expression of SOL-IL-5Ralpha and TM-IL-5Ralpha differs according to the eosinophil activation state and localization in the body (blood vs tissue) and may therefore be involved in the fine-tuning of the eosinophil homeostasis. Exposure of eosinophils to IL-5 reduces their responsiveness to IL-5 by regulated expression of the IL-5Ralpha isoforms. Since, TM-IL-5Ralpha is down-regulated and SOL-IL-5Ralpha (antagonistic) is upregulated in NP tissue, our findings are important to understand the clinical trials with anti-IL-5 in humans.

Differentiation of chronic sinus diseases by measurement of inflammatory mediators

BACKGROUND

Chronic rhinosinusitis (CRS) clinically is a heterogeneous group of sinus diseases, which may cover different disease entities, or may represent a disease continuum. Studying inflammatory cells and mediators in clearly defined disease subgroups may lead to a better differentiation of chronic sinus diseases.

METHODS

Sinonasal mucosal tissue from 10 nasal polyp (NP) patients, 13 cystic fibrosis patients (CF-NP), eight CRS subjects without polyps, and nine control patients were stained for CD3, CD25, CD68, CD20, myeloperoxidase (MPO), CD138 and tissue homogenates were assayed for eotaxin, interleukin (IL)-1beta, IL-2sRalpha, IL-5, interferon (IFN)-gamma, IL-8, transforming growth factor (TGF)-beta1, tumor necrosis factor-alpha, and MPO by enzyme-linked immunosorbent assay or UNICAP system.

RESULTS

Nasal polyp and CF-NP showed increased numbers and activation of T cells, while only NP displayed an increase in plasma cells. Nasal polyp had significantly higher levels of eosinophilic markers [eosinophils, eotaxin, and eosinophil cationic protein (ECP)] compared with CRS, controls and CF-NP. Chronic rhinosinusitis was characterized by a Th1 polarization with high levels of IFN-gamma and TGF-beta, while NP showed a Th2 polarization with high IL-5 and immunoglobulin (Ig) E concentrations. Nasal polyp and CF-NP were discriminated by edema from CRS and controls, with CF-NP displaying a very prominent neutrophilic inflammation.

CONCLUSION

Based on cellular and mediator profiles, we suggest that CRS, NP, and CF-NP are distinct disease entities within the group of chronic sinus diseases.

An update on the impact of Staphylococcus aureus enterotoxins in chronic sinusitis with nasal polyposis

Nasal polyps in adults, characterized by abundant eosinophils, local overproduction of immunoglobulin E, and often associated with asthma, have been appreciated as an eosinophilic inflammation, potentially of allergic origin, but unrelated to a bacterial impact. Evidence accumulates, however, that Staphylococcus aureus colonizes chronic rhinosinusitis with, but not without polyps, with significantly increased prevalence. The germs release enterotoxins, which act as superantigens and induce a topical multiclonal IgE-formation as well as a severe, possibly steroid-insensitive eosinophilic inflammation. Recently, S. aureus could be demonstrated to reside intraepithelially, and potentially to release superantigens into the tissue from within the epithelial cells. An immune defect, either in the innate or adaptive immunity, might be responsible for this phenomenon. Follicle-like structures and lymphocyte accumulations, specifically binding enterotoxins, can be found within the polyp tissues, giving rise to local IgE formation. The superantigen-induced immune response also leads to a modulation of the severity of the eosinophilic inflammation, and may be linked to lower airway co-morbidity in polyp patients. Interestingly, IgE antibodies to enterotoxins can be found in the majority of aspirin-sensitive polyp tissues, associated with a substantial increase in ECP and IL-5. The possible role of S. aureus enterotoxins in polyp disease in Europe, the US and Asia has meanwhile been supported by several studies, demonstrating the presence of IgE antibodies to enterotoxins and inflammatory consequences in nasal polyp tissue. First studies also point to an involvement of S. aureus derived enterotoxins in lower airway disease, such as severe asthma and exacerbated COPD, clearly suggesting a clinical need for diagnosis and treatment of the germ and its related effects. Therapeutic approaches are so far empirical, and need further study, also serving to proof the clinical relevance of the concept.

Nasal polyps in patients with and without cystic fibrosis: a differentiation by innate markers and inflammatory mediators

BACKGROUND

The dysfunction of the mucosal interface of the upper respiratory tract in cystic fibrosis (CF) patients is clinically visible by the development of nasal polyps (NP) at a young age. Innate defence markers and inflammatory mediators in NP from patients with CF were compared with non-cystic fibrosis nasal polyps (non-CF-NP) to determine a possible different immunological background in macroscopically similar tissue.

METHODS

Surgical samples were obtained from patients with non-CF-NP, cystic fibrosis patients with nasal polyps (CF-NP) and control patients (CO). With real time PCR, the mRNA expression of human beta defensins (HBD) 2 and 3, toll-like receptors (TLR) 2 and 4 and the macrophage mannose receptor (MMR) were measured. On homogenates of the surgical samples eotaxin, myeloperoxidase (MPO), IL-5 and IL-8 protein content was measured using commercial ELISA kits; IgE and eosinophilic cationic protein (ECP) were measured by the Unicap system.

RESULTS

In CF-NP we found a statistically significant higher mRNA expression of HBD 2 compared with non-CF-NP and CO and of TLR 2 compared with non-CF-NP. In the non-CF-NP group, MMR mRNA expression was significantly elevated compared with CO and CF-NP. For TLR 4 mRNA expression no statistically significant differences were found between groups. IL-5 was below detection level in all CO and CF-NP, but was measurable in 80% of the non-CF-NP. MPO and IL-8 concentrations were significantly higher in CF-NP compared with CO and non-CF-NP, whereas ECP, eotaxin and IgE were significantly higher in the non-CF-NP group.

CONCLUSIONS

We here demonstrate that CF-NP and non-CF-NP not only differ in terms of inflammatory mediator profile, but also in terms of innate markers.

Organization of secondary lymphoid tissue and local IgE formation to Staphylococcus aureus enterotoxins in nasal polyp tissue

BACKGROUND

Bilateral nasal polyposis (NP) is characterized by high concentrations of IgE in NP tissue, which show no relation to the atopic status. We aimed to study the relationship between systemic and local IgE formation, nasal carriage of Staphylococcus aureus and nasal polyposis.

METHODS

In serum and nasal tissue homogenates from 24 NP patients and 12 controls, we determined concentrations of total IgE and IgE antibodies to inhalant allergens and S. aureus enterotoxins (SAEs; A,B,C,D,E,TSST) by ImmunoCAP. Tissue cryosections were stained for CD3, CD20, CD38, CD23, FcepsilonRI, IgE and SEA/SEB.

RESULTS

We demonstrated a higher incidence of S. aureus colonization (17/24) and IgE antibodies to SAEs in NP tissue (12/24) compared with controls (3/12 and 0/12, respectively). Total IgE and IgE antibodies in serum and NP tissue were dissociated because of local polyclonal IgE formation in NP tissue. Staining of NP tissue revealed follicular structures characterized by B and T cells, and lymphoid accumulations with diffuse plasma cell infiltration.

CONCLUSIONS

We demonstrated the organization of secondary lymphoid tissue in polyp tissue and a polyclonal hyper-immunoglobulinemia E associated with the presence of IgE antibodies to SAEs, colonization with S. aureus, and tissue eosinophilia in a relevant subgroup of polyp patients.

Macrophage mannose receptor in chronic sinus disease

BACKGROUND

The role of infectious agents in the onset and maintenance of chronic sinus disease is still not fully understood. Macrophage mannose receptor (MMR), an innate pattern recognizing receptor, capable of phagocytosis of invaders and signal transduction for proinflammatory mechanisms, might be of importance in immune interactions in chronic sinus disease.

OBJECTIVE

We examined the MMR in sinonasal airway mucosa to evaluate its possible role in chronic rhinosinusitis (CS) and nasal polyposis (NPs).

METHODS

Surgical samples from patients with sinonasal disease were investigated with real-time RT-PCR for quantification of MMR mRNA expression, and the presence and location of MMR-positive cells was analysed by immunohistochemistry.

RESULTS

Quantification of MMR mRNA showed a statistically significant higher expression in NPs compared to CS without NP and controls. Immunohistochemistry revealed expression of MMR in all tissue samples; however, in NP we found an enhanced positive cellular staining including cell aggregates.

CONCLUSIONS

We could demonstrate for the first time that the expression of MMR is significantly upregulated in NP compared to patients with CS without NP or turbinate tissue of controls. Macrophages expressing MMR, accumulated in cell aggregates in NPs, play a possible key role in pathogen-macrophage interaction in NP disease.

Human beta-defensins and toll-like receptors in the upper airway

BACKGROUND

Measurement of innate markers in nasal mucosa, tonsils and adenoids might lead to new views about the role of innate immunity in the upper airway. In this study, the expression of human beta-defensins (HBD) 2 and 3 and toll-like receptors (TLR) 2 and 4 in various upper airway diseases was investigated.

METHODS

Surgical samples from patients with tonsillar disease (n = 18), hypertrophic adenoids (n = 10) and sinonasal disease (n = 30) (chronic sinusitis, nasal polyps, turbinate mucosa as controls) were investigated by immunohistochemistry. Quantification of HBD-2 and 3 mRNA, TLR-2 and 4 mRNA expression was performed by real-time polymerase chain reaction (PCR).

RESULTS

Immunohistochemistry revealed a strong expression of HBD-2 in tonsillar tissue. Quantification of HBD-2 and HBD-3 mRNA showed a more than tenfold higher expression in tonsillar tissue than in adenoids, whereas in nasal biopsies, only negligible defensin expression could be measured. No significant differences were found for TLR-4 between the various tissues, whereas TLR-2 expression in adenoids was significantly lower compared with other tissues.

CONCLUSION

These results demonstrate a strong defensin expression in tonsillar tissue compared with nasal and paranasal mucosa and adenoids. Toll-like receptor expression in all these tissues illustrates a possibly important immunological sentinel function of upper airway mucosa.

Enhanced soluble interleukin-5 receptor alpha expression in nasal polyposis

BACKGROUND

Alternative splicing of the interleukin-5 receptor alpha (IL-5Ralpha)-subunit leads to the generation of a signalling, membrane-anchored (TM) isoform, or a secreted [soluble (SOL)], antagonistic variant. Given the key role of IL-5 in eosinophil function, we investigated SOL IL-5Ralpha expression pattern in an eosinophil-associated disease such as nasal polyposis (NP).

METHODS

An SOL IL-5Ralpha enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction (PCR) were established and applied in serum, nasal secretion and nasal tissue of controls (n = 12), and NP patients (n = 42) with or without asthma.

RESULTS

Analysis of serum, nasal secretion, and nasal tissue samples revealed that SOL IL-5Ralpha protein concentrations were significantly increased in NP vs control tissue. Within the NP group, there was a significant up-regulation of SOL IL-5Ralpha in patients with systemic airway disease. These findings were confirmed at the mRNA level, using an optimized real-time reverse-transcriptase PCR procedure.

CONCLUSIONS

This report demonstrates SOL IL-5Ralpha transcript and protein up-regulation in NP. Soluble IL-5Ralpha differentiates nasal polyps with or without concomitant asthma. As SOL IL-5Ralpha is strongly up-regulated for disease and has antagonistic properties in vitro, our studies shed new light on the mechanisms of specific immunomodulatory therapies, such as anti-IL-5.

Up-regulation of IL-18 in allergic rhinitis

BACKGROUND

This paper reports a study on the concentrations of the pro-inflammatory cytokines IL-18 and IL-1beta in nasal secretions of allergic rhinitis patients in relation to ECP and nasal symptoms.

METHODS

We measured IL-18 and IL-1beta concentrations using ELISA, and eosinophilic cationic protein (ECP) using the CAP system, in nasal secretions of 15 seasonal allergic rhinitis (SAR) patients at six visits throughout the pollen season. Pollen exposure, nasal and ocular symptoms were monitored daily. Furthermore, we measured IL-18, IL-1beta and ECP concentrations in nasal secretions of 19 controls and 20 symptomatic persistent allergic rhinitis (PAR) patients with house dust mite allergy.

RESULTS

In SAR, the increase of IL-18, IL-1beta and ECP paralleled the pollen flight with a time delay. IL-18 and IL-1beta significantly increased during the pollen season compared to baseline, and differently from ECP, remained elevated until 4 weeks after the season. In PAR, the concentrations of IL-18 and ECP, but not IL-1beta, were significantly higher compared to controls, with IL-18 concentrations also being significantly higher than in SAR.

CONCLUSION

This is the first study to demonstrate the up-regulation of IL-18 in nasal secretions in allergic rhinitis. The persistence of elevated IL-18 concentrations until after the season and the high concentrations in PAR compared to SAR suggests its role in persistent allergic inflammation.

Total and specific IgE in nasal polyps is related to local eosinophilic inflammation

BACKGROUND

Nasal polyps (NPs) are characterized by eosinophilic inflammation and often coexist with asthma. However, the role of atopy and IgE in NP pathogenesis is unclear.

OBJECTIVE

We sought to determine whether there is an association between total and specific IgE to a variety of allergens in polyp and nonpolyp tissue and markers of eosinophilic inflammation or skin test results.

METHODS

Homogenates were prepared from nasal tissue of 20 patients with NPs and 20 patients without NPs and analyzed for concentrations of IL-5, IL-4, eotaxin, leukotriene (LT) C4/D4/E4, sCD23, and histamine (ELISA). Eosinophil cationic protein (ECP), tryptase, and total and specific IgE for inhalant allergens and Staphylococcus aureus enterotoxins were measured (ImmunoCAP).

RESULTS

The concentrations of total IgE, IL-5, eotaxin, ECP, LTC4/D4/E4, and sCD23 were significantly higher in NP tissue compared with nonpolyp tissue. Total IgE was significantly correlated to IL-5, ECP, LTC4/D4/E4, and sCD23 and to the number of eosinophils in NPs. On the basis of the presence of specific IgE antibodies in tissue, 3 NP groups were defined. NP group 1 demonstrated no measurable specific IgE, and NP group 2 selected specific IgE. The third group demonstrated a multiclonal specific IgE, including IgE to S aureus enterotoxins, a high total IgE level, and a high prevalence of asthma.

CONCLUSIONS

These studies suggest that there is an association between increased levels of total IgE, specific IgE, and eosinophilic inflammation in NPs, which may be of relevance in the pathophysiology of nasal polyposis. Similarly, the presence of specific IgE to staphylococcal enterotoxins A and B also points to a possible role of bacterial superantigens.

Elevated levels of myeloperoxidase, pro-inflammatory cytokines and chemokines in naturally acquired upper respiratory tract infections

Upper respiratory tract infections (URTIs) are characterised by a neutrophilic mucosal infiltration. The purpose of this study was to investigate the time course of release of the cytokines/chemokines interleukins (IL) IL-1beta, IL-1ra, tumour necrosis factor-alpha (TNF-alpha), IL-6, IL-8, interferon-gamma (IFN-gamma) and monocyte chemotactic protein (MCP-1), soluble intercellular adhesion molecule-1 (sICAM-1), myeloperoxidase (MPO) and bradykinin in nasal secretions of patients with a naturally acquired URTI. A total of 117 healthy adult volunteers were recruited for baseline nasal lavages, 39 of whom developed URTI symptoms within 6 months and returned to our centre within 48 h. Lavages were performed daily during the symptomatic period and 3 weeks thereafter, with symptoms no longer present. Compared to baseline, significantly elevated concentrations of total protein, bradykinin, IL-1beta, TNF-alpha, IL-6, IL-8, MCP-1, IFN-gamma, MPO and sICAM-1 were detected in nasal lavage fluids of symptomatic patients, whereas IL-1ra remained unaltered. All studied variables reached baseline 3 weeks after the URTI. Naturally acquired URTI represent a limited, neutrophilic inflammatory reaction, orchestrated by the release of pro-inflammatory cytokines and chemokines.

Nasal polyposis: from cytokines to growth

Nasal polyposis (NP) is a chronic inflammatory condition that is mostly characterized by an infiltration of eosinophils. How this eosinophilic inflammation leads to polyp formation remains largely unclear. In order to identify the most important factors in polyp growth, first we report the histologic features of two early stage manifestations of eosinophilic nasal polyps compared to their surrounding normal mucosa and mature polyps from the same patients. Histomorphologic analysis of these early stage manifestations of NP showed the presence of eosinophils, forming a subepithelial cap over a pseudocyst area that was filled with albumin. In mature NP, a large pseudocyst area containing albumin was surrounded by subepithelial eosinophilia. Second, in an approach to quantify and to study possible relations between eosinophilic inflammation and changes in extracellular tissue components we measured interleukin-5 (IL-5), eotaxin, eosinophil cationic protein (ECP), leukotrienes (LTC4/D4/E4), transforming growth factor-beta 1 (TGF-beta 1), fibronectin, hyaluronic acid, and albumin in nasal tissue homogenates of 31 subjects. Nasal polyp samples (n = 16) were obtained during routine endonasal sinus surgery, whereas control non-polyp samples (n = 15) from subjects with (6) and without (9) allergic rhinitis were obtained from the inferior turbinate during septum surgery. In the group of polyp patients 11 received no treatment, whereas 5 were treated with oral glucocorticoids (GCS) within 4 weeks before surgery. IL-5 was measurable in 8 of 11 untreated NP, whereas IL-5 could not be detected in all 15 controls nor in 4 of 5 oral corticoid-treated polyps. The comparison between the untreated polyp group and controls showed significantly higher concentrations of IL-5, eotaxin, ECP, and albumin in polyp supernatants, whereas TGF-beta 1 was significantly lower. In the oral GCS-treated group, ECP and albumin were significantly reduced compared to untreated nasal polyps. The same tendency, but not reaching significance, was seen for eotaxin and fibronectin, while no difference was found for LTC4/D4/E4 and hyaluronic acid between the groups. Our observations suggest a deposition of albumin (and possibly other plasma proteins) and extracellular matrix proteins, which may be regulated by the subepithelial eosinophilic inflammation, as a possible pathogenic principle of polyp formation and growth. IL-5 and eotaxin are found to be key factors for eosinophilic accumulation and activation in NP. Oral corticoid treatment may lead to the shrinkage of NP by downregulation of the eosinophilic inflammation and reduction of the extravasation and deposition of albumin in NP.

Cytokines and adhesion molecules in allergic rhinitis

This review summarizes our current knowledge of nasal allergic inflammation based on studies of cytokines, chemokines, and adhesion molecules in allergic rhinitis. The article also includes some aspects of viral rhinitis. Due to artificial or natural allergen exposure, an increase in the number of eosinophils and basophils, mast cells, IgE-positive cells, macrophages, monocyte-like cells, Langerhans cells, and activated T-cells can be observed within the mucosa and on the mucosal surface. Mediators are known to be released in response to allergens, but do not seem to be adequate to initiate the cell recruitment. After antigen challenge, the release of proinflammatory and regulatory cytokines could be demonstrated, and TH2-type cytokine mRNA upregulation in allergic mucosa has been shown. Proinflammatory cytokines initiate an adhesion cascade and activate T-cells that create an "atopic" cytokine environment within the tissue, which also may be linked to the long-term selective recruitment of eosinophils. However, the acute selective migration of eosinophils after allergen challenge is not fully understood, nor is the role of chemokines in allergic and viral rhinitis. Allergic rhinitis clearly represents an inflammatory reaction.

Elevated levels of interleukins IL-1 beta, IL-6 and IL-8 in naturally acquired viral rhinitis

We studied the cytokines IL(interleukin)-1 beta, IL-4, IL-6 and IL-8 in nasal lavage samples from 20 patients with naturally acquired viral rhinitis and 5 healthy controls without nasal complaints. IL-1 beta, IL-6 and IL-8 levels in lavage fluid from the viral rhinitis patients were significantly elevated when compared to control subjects. IL-4 was not measurable in any of the samples. The cytokine levels in secretions from the healthy controls remained stable intraindividually on 5 consecutive sampling days. We suggest that cytokines such as IL-1 beta, IL-6 and IL-8, but not IL-4, are involved in the pathophysiology of the common cold.