Non-allergic rhinitis: Position paper of the European Academy of Allergy and Clinical Immunology

This EAACI position paper aims at providing a state-of-the-art overview on nonallergic rhinitis (NAR). A significant number of patients suffering from persistent rhinitis are defined as nonallergic noninfectious rhinitis (NANIR) patients, often denominated in short as having NAR. NAR is defined as a symptomatic inflammation of the nasal mucosa with the presence of a minimum of two nasal symptoms such as nasal obstruction, rhinorrhea, sneezing, and/or itchy nose, without clinical evidence of endonasal infection and without systemic signs of sensitization to inhalant allergens. Symptoms of NAR may have a wide range of severity and be either continuously present and/or induced by exposure to unspecific triggers, also called nasal hyperresponsiveness (NHR). NHR represents a clinical feature of both AR and NAR patients. NAR involves different subgroups: drug-induced rhinitis, (nonallergic) occupational rhinitis, hormonal rhinitis (including pregnancy rhinitis), gustatory rhinitis, senile rhinitis, and idiopathic rhinitis (IR). NAR should be distinguished from those rhinitis patients with an allergic reaction confined to the nasal mucosa, also called "entopy" or local allergic rhinitis (LAR). We here provide an overview of the current consensus on phenotypes of NAR, recommendations for diagnosis, a treatment algorithm, and defining the unmet needs in this neglected area of research.

EUFOREA Rhinology Research Forum 2016: report of the brainstorming sessions on needs and priorities in rhinitis and rhinosinusitis

The first European Rhinology Research Forum organized by the European Forum for Research and Education in Allergy and Airway Diseases (EUFOREA) was held in the Royal Academy of Medicine in Brussels on 17th and 18th November 2016, in collaboration with the European Rhinologic Society (ERS) and the Global Allergy and Asthma European Network (GA2LEN). One hundred and thirty participants (medical doctors from different specialties, researchers, as well as patients and industry representatives) from 27 countries took part in the multiple perspective discussions including brainstorming sessions on care pathways and research needs in rhinitis and rhinosinusitis. The debates started with an overview of the current state of the art, including weaknesses and strengths of the current practices, followed by the identification of essential research needs, thoroughly integrated in the context of Precision Medicine (PM), with personalized care, prediction of success of treatment, participation of the patient and prevention of disease as key principles for improving current clinical practices. This report provides a concise summary of the outcomes of the brainstorming sessions of the European Rhinology Research Forum 2016.

Positioning the principles of precision medicine in care pathways for allergic rhinitis and chronic rhinosinusitis - A EUFOREA-ARIA-EPOS-AIRWAYS ICP statement

Precision medicine (PM) is increasingly recognized as the way forward for optimizing patient care. Introduced in the field of oncology, it is now considered of major interest in other medical domains like allergy and chronic airway diseases, which face an urgent need to improve the level of disease control, enhance patient satisfaction and increase effectiveness of preventive interventions. The combination of personalized care, prediction of treatment success, prevention of disease and patient participation in the elaboration of the treatment plan is expected to substantially improve the therapeutic approach for individuals suffering from chronic disabling conditions. Given the emerging data on the impact of patient stratification on treatment outcomes, European and American regulatory bodies support the principles of PM and its potential advantage over current treatment strategies. The aim of the current document was to propose a consensus on the position and gradual implementation of the principles of PM within existing adult treatment algorithms for allergic rhinitis (AR) and chronic rhinosinusitis (CRS). At the time of diagnosis, prediction of success of the initiated treatment and patient participation in the decision of the treatment plan can be implemented. The second-level approach ideally involves strategies to prevent progression of disease, in addition to prediction of success of therapy, and patient participation in the long-term therapeutic strategy. Endotype-driven treatment is part of a personalized approach and should be positioned at the tertiary level of care, given the efforts needed for its implementation and the high cost of molecular diagnosis and biological treatment.

Prospective open-label evaluation of long-term low-dose doxycycline for difficult-to-treat chronic rhinosinusitis with nasal polyps

BACKGROUND

This study aimed to assess clinical outcomes of long-term low-dose oral doxycycline therapy in difficult-to-treat chronic rhinosinusitis with polyps (CRSwNP).

METHODS

This was a prospective, open-label study of 60 patients with difficult-to-treat CRSwNP who had undergone endoscopic sinus surgery. Patients were divided into two groups: 28 received nasal steroids, saline irrigation, and doxycycline (200 mg on the first day, followed by 100 mg once daily) for 12 weeks, while 30 received only nasal steroids and saline irrigation. The main outcome measure was an adequate effect size of doxycycline treatment on clinically meaningful significant improvement of SNOT-20. Other outcome measures were the SNOT-20, NOSE, and Lund-Kennedy scores. The following parameters were also analyzed: asthma, rhinitis, non-steroidal-exacerbated respiratory disease (NERD), and baseline serum IgG, IgA, IgE, IgM, ANCA, and eosinophil count.

RESULTS

There was an adequate effect size of doxycycline treatment on clinically meaningful significant improvement of SNOT-20. Patients who received doxycycline also had significantly better outcomes regarding SNOT-20, NOSE, and Lund-Kennedy scores. There was a negative association among a clinically significant improvement of SNOT-20 and presence of asthma, NERD, and elevated serum IgE levels before treatment.

CONCLUSION

These findings suggest that doxycycline may have a beneficial role for CRSwNP patients, especially for patients without asthma, NERD or high levels of serum IgE before treatment.

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.

Multi-morbidities of allergic rhinitis in adults: European Academy of Allergy and Clinical Immunology Task Force Report

This report has been prepared by the European Academy of Allergy and Clinical Immunology Task Force on Allergic Rhinitis (AR) comorbidities. The aim of this multidisciplinary European consensus document is to highlight the role of multimorbidities in the definition, classification, mechanisms, recommendations for diagnosis and treatment of AR, and to define the needs in this neglected area by a literature review. AR is a systemic allergic disease and is generally associated with numerous multi-morbid disorders, including asthma, eczema, food allergies, eosinophilic oesophagitis (EoE), conjunctivitis, chronic middle ear effusions, rhinosinusitis, adenoid hypertrophy, olfaction disorders, obstructive sleep apnea, disordered sleep and consequent behavioural and educational effects. This report provides up-to-date usable information to: (1) improve the knowledge and skills of allergists, so as to ultimately improve the overall quality of patient care; (2) to increase interest in this area; and (3) to present a unique contribution to the field of upper inflammatory disease.

Prospective open-label evaluation of long-term low-dose doxycycline for difficult-to-treat chronic rhinosinusitis with nasal polyps

BACKGROUND

This study aimed to assess clinical outcomes of long-term low-dose oral doxycycline therapy in difficult-to-treat chronic rhinosinusitis with polyps (CRSwNP).

METHODS

This was a prospective, open-label study of 60 patients with difficult-to-treat CRSwNP who had undergone endoscopic sinus surgery. Patients were divided into two groups: 28 received nasal steroids, saline irrigation, and doxycycline (200 mg on the first day, followed by 100 mg once daily) for 12 weeks, while 30 received only nasal steroids and saline irrigation. The main outcome measure was an adequate effect size of doxycycline treatment on clinically meaningful significant improvement of SNOT-20. Other outcome measures were the SNOT-20, NOSE, and Lund-Kennedy scores. The following parameters were also analyzed: asthma, rhinitis, non-steroidal-exacerbated respiratory disease (NERD), and baseline serum IgG, IgA, IgE, IgM, ANCA, and eosinophil count.

RESULTS

There was an adequate effect size of doxycycline treatment on clinically meaningful significant improvement of SNOT-20. Patients who received doxycycline also had significantly better outcomes regarding SNOT-20, NOSE, and Lund-Kennedy scores. There was a negative association among a clinically significant improvement of SNOT-20 and presence of asthma, NERD, and elevated serum IgE levels before treatment.

CONCLUSION

These findings suggest that doxycycline may have a beneficial role for CRSwNP patients, especially for patients without asthma, NERD or high levels of serum IgE before treatment.

Raised immunoglobulin A and circulating T follicular helper cells are linked to the development of food allergy in paediatric liver transplant patients

BACKGROUND

Post-transplant food allergy (LTFA) is increasingly observed after paediatric liver transplantation (LT). Although the immunopathology of LTFA remains unclear, immunoglobulin (Ig) E seems to be implicated.

OBJECTIVE

To study humoral and cellular immunity in paediatric LT patients in search for factors associated with LTFA, and compare with healthy controls (HC) and non-transplant food-allergic children (FA).

METHODS

We studied serum Ig levels in 29 LTFA, 43 non-food-allergic LT patients (LTnoFA), 21 FA patients and 36 HC. Serum-specific IgA and IgE against common food allergens in LTFA, IgA1 , IgA2 and joining-chain-containing polymeric IgA (pIgA) were measured. Peripheral blood mononuclear cells were analysed by flow cytometry for B and T cell populations of interest.

RESULTS

Serum IgA and specific IgA were higher in LTFA compared to LTnoFA. LTFA patients had the highest proportion of circulating T follicular helper cells (cTfh). The percentage of cTfh correlated positively with serum IgA. Unique in LTFA was also the significant increase in serum markers of mucosal IgA and the decrease in the Th17 subset of CXCR5(-) CD4(+) cells compared to HC. Both LT patients exhibited a rise in IgA(+) memory B cells and plasmablasts compared to HC and FA.

CONCLUSIONS

LT has an impact on humoral immunity, remarkably in those patients developing FA. The increase in serum markers of mucosal IgA, food allergen-specific IgA and cTfh cells observed in LTFA, point towards a disturbance in intestinal immune homoeostasis in this patient group.

Local IgE in non-allergic rhinitis

Local allergic rhinitis (LAR) is characterized by the presence of a nasal Th2 inflammatory response with local production of specific IgE antibodies and a positive response to a nasal allergen provocation test (NAPT) without evidence of systemic atopy. The prevalence has been shown to be up to 25% in subjects affected with rhinitis with persistence, comorbidity and evolution similar to allergic rhinitis. LAR is a consistent entity that does not evolve to allergic rhinitis with systemic atopy over time although patients have significant impairment in quality of life and increase in the severity of nasal symptoms over time. Lower airways can be also involved. The diagnosis of LAR is based mostly on demonstration of positive response to NAPT and/or local synthesis of specific IgE. Allergens involved include seasonal or perennial such as house dusts mites, pollens, animal epithelia, moulds (alternaria) and others. Basophils from peripheral blood may be activated by the involved allergens suggesting the spill over of locally synthesized specific IgE to the circulation. LAR patients will benefit from the same treatment as allergic patients using antihistamines, inhaled corticosteroids and IgE antagonists. Studies on immunotherapy are ongoing and will determine its efficacy in LAR in terms of symptoms improvement and evolution of the natural course of the disease.

Calcineurin inhibitors dampen humoral immunity by acting directly on naive B cells

Calcineurin inhibitors (CNI), used frequently in solid organ transplant patients, are known to inhibit T cell proliferation, but their effect on humoral immunity is far less studied. Total and naive B cells from healthy adult donors were cultured in immunoglobulin (Ig)A- or IgG/IgE-promoting conditions with increasing doses of cyclosporin, tacrolimus, rapamycin or methylprednisolone. The effect on cell number, cell division, plasmablast differentiation and class-switching was tested. To examine the effect on T follicular helper (Tfh) cell differentiation, naive CD4(+) T cells were cultured with interleukin (IL)-12 and titrated immunosuppressive drug (IS) concentrations. Total B cell function was not affected by CNI. However, naive B cell proliferation was inhibited by cyclosporin and both CNI decreased plasmablast differentiation. Both CNI suppressed IgA, whereas only cyclosporin inhibited IgE class-switching. Rapamycin had a strong inhibitory effect on B cell function. Strikingly, methylprednisolone, increased plasmablast differentiation and IgE class-switching from naive B cells. Differentiation of Tfh cells decreased with increasing IS doses. CNI affected humoral immunity directly by suppressing naive B cells. CNI, as well as rapamycin and methylprednisolone, inhibited the in-vitro differentiation of Tfh from naive CD4(+) T cells. In view of its potent suppressive effect on B cell function and Tfh cell differentiation, rapamycin might be an interesting candidate in the management of B cell mediated complications post solid organ transplantation.

In vivo diagnosis of allergic diseases--allergen provocation tests

The allergen challenge test has been the mainstay of diagnosis of allergic diseases for a long time since it offers a direct proof of the clinical relevance of a particular allergen for the allergic disease symptoms and severity. Standardisation and availability for daily practice (including safety issues) are still to be refined but most of the challenge tests have safely crossed the border from research tools to diagnostic tests available for daily practice for a well trained clinical staff.

Vascular endothelial growth factor receptor 1 expression in nasal polyp tissue

BACKGROUND

Edema represents a key feature of nasal polyp (NP) disease. Members of the vascular endothelial growth factor (VEGF) family may be involved, but the precise role of VEGF-A, VEGF-B, placental growth factor (PlGF), and their receptors VEGFR1 and VEGFR2 in NP edema formation remains elusive.

OBJECTIVE

Exploring the expression of VEGF family members and their receptors and their correlation with clinical, radiological, and edema markers in NP.

METHODS

The expression of VEGF-A, VEGF-B, PlGF, VEGFR1, and VEGFR2 was measured in NP (n = 23) and control tissue (n = 22) at mRNA and protein level. Edema was evaluated by measuring albumin levels and wet/dry ratios. Computed tomography (CT) scans were scored using the Lund-Mackay scoring system. IL-5 mRNA expression was determined by real-time RT-PCR. Cell suspensions from NP (n = 10) and control tissue (n = 12) were stimulated in vitro with IL-1β or TNFα.

RESULTS

mRNA expression of VEGFR1 and VEGF-B was significantly higher in NP compared with control tissue. Expression levels of VEGF-B and VEGFR1 significantly correlated with NP albumin content (VEGF-B: P = 0.0208; VEGFR1: P = 0.0293), CT scan scores (VEGF-B: P = 0.0075; VEGFR1: P = 0.0068), and IL-5 mRNA (VEGF-B: P = 0.0027; VEGFR1: P = 0.0001). In vitro stimulation of control and NP tissue cell suspensions with IL-1β or TNFα significantly reduced the expression of VEGFR2 in control tissue, without altering VEGFR1 and VEGF-B expression. hVEGF-B induced nitric oxide production in NP macrophages (P < 0.05).

CONCLUSION

Expression levels of VEGFR1 and VEGF-B correlate with edema and clinical markers of NP disease and therefore represent potential therapeutic targets.

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 receptor revision and class switching to IgE in chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (NP) and allergic rhinitis (AR) is characterized by local Th2 inflammation and up-regulation of IgE; however, IgE in NP is 'polyclonal' and allergen specific, whereas IgE in AR is 'oligoclonal' and allergen specific. Germinal center (GC) reactions occur in AR, while only the formation of GC-like structures in NP is described. The aim of this study was to investigate the involvement of local IgE production, class switch recombination, and receptor revision in NP.

METHODS

We compared the levels of local IgE, germline gene transcripts, and mature Ig mRNA expression, recombination activating gene (RAG1 and RAG2), key markers of Th2 inflammation, and GC reactions in NP tissue vs AR and control tissue. Nasal mucosa was immunostained for the co-expression of RAG1 and RAG2 in B cells, plasma cells, and T cells, using dual or triple immunofluorescence (IF).

RESULTS

In NP, local IgE level and key markers of local class switching are increased compared with AR and normal controls (NC). In NP, switch circle transcripts reveal ongoing local class switch recombination to IgE. Up to 30% of B cells, plasma cells, and T cells in nasal polyps re-express both RAG1 and RAG2, required for receptor revision. RAG1 and RAG2 mRNA concentrations are increased in NP and correlated with the magnitude of inflammation and the presence of S. aureus enterotoxin (superantigen)-specific IgE in the nasal polyp mucosa.

CONCLUSION

Our results provide the first evidence of local receptor revision and class switching to IgE, and B-cell differentiation into IgE-secreting plasma cells in NP.

Uncontrolled allergic rhinitis and chronic rhinosinusitis: where do we stand today?

State-of-the-art documents like ARIA and EPOS provide clinicians with evidence-based treatment algorithms for allergic rhinitis (AR) and chronic rhinosinusitis (CRS), respectively. The currently available medications can alleviate symptoms associated with AR and RS. In real life, a significant percentage of patients with AR and CRS continue to experience bothersome symptoms despite adequate treatment. This group with so-called severe chronic upper airway disease (SCUAD) represents a therapeutic challenge. The concept of control of disease has only recently been introduced in the field of AR and CRS. In case of poor control of symptoms despite guideline-directed pharmacotherapy, one needs to consider the presence of SCUAD but also treatment-related, diagnosis-related and/or patient-related factors. Treatment-related issues of uncontrolled upper airway disease are linked with the correct choice of treatment and route of administration, symptom-oriented treatment and the evaluation of the need for immunotherapy in allergic patients. The diagnosis of AR and CRS should be reconsidered in case of uncontrolled disease, excluding concomitant anatomic nasal deformities, global airway dysfunction and systemic diseases. Patient-related issues responsible for the lack of control in chronic upper airway inflammation are often but not always linked with adherence to the prescribed medication and education. This review is an initiative taken by the ENT section of the EAACI in conjunction with ARIA and EPOS experts who felt the need to provide a comprehensive overview of the current state of the art of control in upper airway inflammation and stressing the unmet needs in this domain.

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.

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.

Staphylococcus aureus enterotoxin B facilitates allergic sensitization in experimental asthma

BACKGROUND

Staphylococcus aureus Enterotoxin B (SEB) has immunomodulatory effects in allergic airway disease. The potential contribution of SEB to the sensitization process to allergens remains obscure.

OBJECTIVE

In order to study the effects of staphylococcal-derived toxins on the sensitization to ovalbumin (OVA) and induction of allergic airway inflammation, we have combined the nasal application of OVA with different toxins.

METHODS

Nasal applications of OVA and saline, SEA, SEB, toxic shock syndrome toxin (TSST)-1, protein A or lipopolysaccharide (LPS) were performed on alternate days from day 0 till 12. On day 14, mice were killed for the evaluation of OVA-specific IgE, cytokine production by mediastinal lymph node (MLN) cells and bronchial hyperreactivity (BHR) to inhaled metacholine. The effect of SEB on dendritic cell (DC) migration and maturation, and on T cell proliferation was evaluated.

RESULTS

Concomitant endonasal application of OVA and SEB resulted in OVA-specific IgE production, whereas this was not found with SEA, TSST-1, protein A, LPS or OVA alone. Increased DC maturation and migration to the draining lymph nodes were observed in OVA/SEB mice, as well as an increased T cell proliferation. Bronchial inflammation with an influx of eosinophils and lymphocytes was demonstrated in OVA/SEB mice, together with hyperresponsiveness and the production of IL-4, IL-5, IL-10 and IL-13 by MLN stimulated with OVA.

CONCLUSIONS

Our data demonstrate that SEB facilitates sensitization to OVA and consecutive bronchial inflammation with features of allergic asthma. This is likely due to augmentation of DC migration and maturation, as well as the allergen-specific T cell proliferation upon concomitant OVA and SEB application.

Decreased FOXP3 protein expression in patients with asthma

BACKGROUND

T-regulatory cells (T(reg)) are important in balancing immune responses and maintaining peripheral tolerance. Current evidence suggests that asthma is characterized by a relative deficiency in T(reg), allowing T helper 2 cells to expand. In this study, we aimed to evaluate circulating T(reg), defined by the protein FOXP3, in both control subjects and patients with stable asthma.

METHODS

Peripheral blood mononuclear cells (PBMC) of control (n = 14) and asthmatic patients (n = 29) were labeled for CD4, CD25, and intracellular FOXP3 and analyzed using flow cytometry. In CD3/CD28 stimulated PBMC, the effects of dexamethasone on the transcription factors T-bet, GATA-3, FOXP3, and RORc2 and representative cytokines were studied.

RESULTS

In control subjects and asthmatic patients, numbers of peripheral blood CD4(+)CD25(high) and CD4(+)CD25(high)FOXP3(+) T-cells were similar. However, FOXP3 protein expression within CD4(+)CD25(high) T-cells was significantly decreased in asthmatic patients. There was a tendency for increased FOXP3 expression within CD4(+)CD25(high) T-cells in glucocorticosteroid-treated patients when compared to steroid-naive asthmatic patients. In stimulated PBMC, dexamethasone treatment increased the anti-/proinflammatory transcription ratios of FOXP3/GATA-3, FOXP3/T-bet, and FOXP3/RORc2.

CONCLUSION

Asthmatic patients have decreased FOXP3 protein expression within their CD4(+)CD25(high) T(reg). Our findings also suggest that treatment with inhaled glucocorticosteroids in asthmatics might increase this FOXP3 protein expression within the CD4(+)CD25(high) T-cell population.

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.