The importance of local eosinophilia in the surgical outcome of chronic rhinosinusitis: a 3-year prospective observational study.

BACKGROUND: Patients with chronic rhinosinusitis with/without nasal polyps (CRSwNP/CRSsNP) benefit from endoscopic sinus surgery (ESS), with an estimated success rate of 80%. At present, the influence on clinical outcome after ESS of eosinophils, eosinophilic mucin (EM), and fungal hyphae (FH) in secretions remains unclear. By delineating CRS groups and subgroups based on the finding of eosinophils, EM, and FH, differences in recurrence after ESS were investigated. METHODS: A prospective monocenter study including 221 CRS patients who were unresponsive to medical treatment and underwent ESS was performed. All tissue and sinonasal secretions were microscopically examined for the presence of eosinophils, EM, and FH. Patients were followed for 3 years after surgery. Recurrence was defined according to the European position paper on rhinosinusitis and nasal polyps. RESULTS: In total, 96 CRSwNP and 125 CRSsNP patients were included. Tissue eosinophils were found in 78% of CRSwNP patients compared with 42% in CRSsNP patients. EM was observed in 52% of the CRSwNP group versus 20% of the CRSsNP group. Furthermore, secretion analysis revealed FH in 7% of CRS. Recurrence in the total group was 22% over 3 years. CRSwNP patients with tissue eosinophilic involvement showed a recurrence rate of 48%, and those with additional EM showed recurrence in 56%. CONCLUSION: The presence of eosinophils in tissue or airway secretions greatly increases the risk of recurrent disease in CRSwNP patients. The finding of tissue eosinophilia and EM provides valuable information regarding the increased likelihood of CRS recurrence after ESS, whereas the finding of FH does not.

Dissemination and implementation of the ARIA guidelines for allergic rhinitis in general practice.

BACKGROUND: Allergic rhinitis (AR) is a prevalent problem in general practice. The first evidence-based guidelines for AR, the ARIA guidelines, were published and have been updated repeatedly since 2001 in order to improve the care of AR patients. Very limited information, however, is available on the impact of these guidelines on everyday clinical practice. The aim of this study was to evaluate the dissemination and implementation of the ARIA guidelines in general practice. METHODS: Three hundred and fifty Flemish general practitioners (GPs) were recruited to complete a questionnaire covering their demographic and professional characteristics, awareness, perception and implementation of the ARIA guidelines. To assess compliance with the ARIA treatment recommendations, 4 fictitious case scenarios of AR were presented, in which the respondents were asked to select the treatment of choice. RESULTS: Of the 350 GPs included, only 31% were aware of the ARIA guidelines and 10% stated that they implement them. For the diagnosis of AR, 71% of the GPs ask specific IgE tests or perform skin prick tests, whereas only 29% perform an anterior rhinoscopy. ARIA users are more likely to screen for concomitant asthma. In the clinical-case section, there was a large variability in proposed therapeutic strategies. Adherence to the evidence-based ARIA treatment guidelines was low, but recent graduation was a significant predictor of compliance with these recommendations. CONCLUSIONS: The ARIA guidelines remain relatively unknown among Flemish GPs and even those who are aware of them still tend to treat AR independently of the guideline recommendations.

Staphylococcal enterotoxin B influences the DNA methylation pattern in nasal polyp tissue: a preliminary study.

Staphylococcal enterotoxins may influence the pro-inflammatory pattern of chronic sinus diseases via epigenetic events. This work intended to investigate the potential of staphylococcal enterotoxin B (SEB) to induce changes in the DNA methylation pattern. Nasal polyp tissue explants were cultured in the presence and absence of SEB; genomic DNA was then isolated and used for whole genome methylation analysis. Results showed that SEB stimulation altered the methylation pattern of gene regions when compared with non stimulated tissue. Data enrichment analysis highlighted two genes: the IKBKB and STAT-5B, both playing a crucial role in T- cell maturation/activation and immune response.

Omalizumab is effective in allergic and nonallergic patients with nasal polyps and asthma.

BACKGROUND: Adult patients with nasal polyps often have comorbid asthma, adding to the serious effect on the quality of life of these patients. Nasal polyps and asthma might represent a therapeutic challenge; inflammation in both diseases shares many features, such as airway eosinophilia, local IgE formation, and a T(H)2 cytokine profile. Omalizumab is a human anti-IgE mAb with proved efficacy in patients with severe allergic asthma. Omalizumab could be a treatment option for patients with nasal polyps and asthma. OBJECTIVE: The goal of this study was to investigate the clinical efficacy of omalizumab in patients with nasal polyps and comorbid asthma. METHODS: A randomized, double-blind, placebo-controlled study of allergic and nonallergic patients with nasal polyps and comorbid asthma (n = 24) was conducted. Subjects received 4 to 8 (subcutaneous) doses of omalizumab (n = 16) or placebo (n = 8). The primary end point was reduction in total nasal endoscopic polyp scores after 16 weeks. Secondary end points included a change in sinus computed tomographic scans, nasal and asthma symptoms, results of validated questionnaires (Short-Form Health Questionnaire, 31-item Rhinosinusitis Outcome Measuring Instrument, and Asthma Quality of Life Questionnaire), and serum/nasal secretion biomarker levels. RESULTS: There was a significant decrease in total nasal endoscopic polyp scores after 16 weeks in the omalizumab-treated group (-2.67, P = .001), which was confirmed by means of computed tomographic scanning (Lund-Mackay score). Omalizumab had a beneficial effect on airway symptoms (nasal congestion, anterior rhinorrhea, loss of sense of smell, wheezing, and dyspnea) and on quality-of-life scores, irrespective of the presence of allergy. CONCLUSION: Omalizumab demonstrated clinical efficacy in the treatment of nasal polyps with comorbid asthma, supporting the importance and functionality of local IgE formation in the airways.

Syk-kinase inhibition prevents mast cell activation in nasal polyps.

BACKGROUND: Mast cells are crucial effector cells in the allergic cascade. The cross-linking of the high affinity IgE receptor (FcεRI) activates mast cells and basophils. Spleen tyrosine kinase (Syk) is positioned upstream of the IgE receptor signal transducing pathway and may represent an important target for the treatment of nasal inflammatory diseases. OBJECTIVE: We measured effects of a specific Syk inhibitor in the release of mast cell mediators in human cord blood-derived mast cells (CBDMCs) (in-vitro) and in human nasal tissue (ex-vivo). METHODS: Surgical samples were collected from patients with nasal polyposis who underwent sinus surgery. Tissue cubes of +- 0.9 mm3 were primed with myeloma IgE (1 microg/ml), preincubated with Syk inhibitor NVP-QAB205 in different concentrations and then stimulated with tissue culture medium, anti-IgE 10 microg/ml and anti-IgE 30 microg/ml. Supernatants were analysed for concentrations of histamine, LTC4/LTD4/LTE4 and PGD2. CBDMCs were likewise pre-incubated with compound, prior to stimulation with anti-IgE at 10 microg/ml. RESULTS: In CBDMCs, the Syk inhibitor prevented degranulation assessed by measurement of histamine release and the production of LTC4/LTD4/LTE4 and PGD2. Furthermore, the Syk inhibitor was similarly able to significantly inhibit the release of these granules and newly synthesized mediators by nasal polyp mast cells in a dose dependent manner. CONCLUSION: Although the critical role of Syk in the IgE receptor signal transduction pathway has been well documented in vitro, this study supports the importance of Syk in IgE receptor-mediated degranulation of mast cells ex-vivo within nasal tissue. Thus, inhibition of Syk may represent an important therapeutic strategy for the treatment of upper airway disease with mast cell involvement, such as allergic rhinitis.

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.

Efficacy of desloratadine in persistent allergic rhinitis - a GA²LEN study.

BACKGROUND: The ARIA (Allergic Rhinitis and its Impact on Asthma) guidelines proposed a classification for allergic rhinitis based on the duration of symptoms (intermittent or persistent) rather than on the time of allergen exposure (seasonal or perennial). There had been no placebo-controlled, randomized, clinical trial of desloratadine (DL) in patients with persistent allergic rhinitis to date. OBJECTIVES: To assess the efficacy and safety of DL in patients with persistent allergic rhinitis based on the ARIA classification. METHODS: Patients 12 years of age and older with persistent allergic rhinitis were assessed over 85 days of treatment with DL 5 mg once daily (n = 360) or placebo (n = 356). The primary endpoint was the AM/PM reflective total 5-symptom score (T5SS) averaged over days 1-29. Secondary endpoints included AM/PM instantaneous T5SS and individual symptoms, therapeutic response, symptom severity assessed by a visual analogue scale and quality of life. RESULTS: The mean reduction in AM/PM reflective T5SS was significantly greater with DL than placebo over days 1-29 (-3.76 vs. -2.87, p < 0.001) and on each individual day (p < 0.05). The mean AM instantaneous T5SS was significantly reduced with DL compared with placebo as early as day 2 (-1.90 vs. -1.46; p < 0.001). The therapeutic response and improvement in quality of life were significantly greater with DL than placebo (p < 0.001 for each). The frequency of treatment-related adverse events was low and similar between DL (10.0%) and placebo (8.4%). CONCLUSIONS: This study showed DL to be effective and safe in the treatment of persistent allergic rhinitis.

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.

Toward improved ecological validity in the acoustic measurement of overall voice quality: combining continuous speech and sustained vowels.

To improve ecological validity, perceptual and instrumental assessment of disordered voice, including overall voice quality, should ideally sample both sustained vowels and continuous speech. This investigation assessed the utility of combining both voice contexts for the purpose of auditory-perceptual ratings as well as acoustic measurement of overall voice quality. Sustained vowel and continuous speech samples from 251 subjects with (n=229) or without (n=22) various voice disorders were concatenated and perceptually rated on overall voice quality by five experienced voice clinicians. After removing the nonvoiced segments within the continuous speech samples, the concatenated samples were analyzed using 13 acoustic measures based on fundamental frequency perturbation, amplitude perturbation, spectral and cepstral analyses. Stepwise multiple regression analysis yielded a six-variable acoustic model for the multiparametric measurement of overall voice quality of the concatenated samples (with a cepstral measure as the main contributor to the prediction of overall voice quality). The correlation of this model with mean ratings of overall voice quality resulted in r(s)=0.78. A cross-validation approach involving the iterated internal cross-correlations with 30 subgroups of 100, 50, and 10 samples confirmed a comparable degree of association. Furthermore, the ability of the model to distinguish voice-disordered from vocally normal participants was assessed using estimates of diagnostic precision including receiver operating characteristic (ROC) curve analysis, sensitivity, and specificity, as well as likelihood ratios (LRs), which adjust for base-rate differences between the groups. Depending on the cutoff criteria employed, the analyses revealed an impressive area under ROC=0.895 as well as respectable sensitivity, specificity, and LR. The results support the diagnostic utility of combining voice samples from both continuous speech and sustained vowels in acoustic and perceptual analysis of disordered voice. The findings are discussed in relation to the extant literature and the need for further refinement of the acoustic algorithm.

[GA2LEN (Global Allergy and Asthma European Network), the perspective of the German speaking centers]. / GA2LEN (Global Allergy and Asthma European Network), die Perspektive der deutschsprachigen Zentren.

Allergic diseases represent a major health problem in Europe. They are increasing in prevalence, severity and costs. GA2LEN (Global Allergy and Asthma European Network), an FP6 Network of Excellence, was created in 2005 as a vehicle to ensure excellence in research bringing together research and clinical institutions to combat fragmentation in the European research area and to tackle allergy as a whole. GA2LEN benefited greatly from the voluntary efforts of researchers who are strongly committed to this model of pan-European collaboration. The network was organized in order to increase networking for scientific projects in allergy and asthma around Europe and to make GA2LEN the world leader in the field. Besides these activities, research has been jointly made and the first papers are being published. GA2LEN achievements in general can be grouped as those for a durable infrastructure built up during the project phase those which are project-related work based on these novel infrastructures, and the development and implementations of guidelines. The major achievements of GA2LEN are reported in this paper.

Acoustic measurement of overall voice quality: a meta-analysis.

Over the past several decades, many acoustic markers have been proposed to be sensitive to and measure overall voice quality. This meta-analysis presents a retrospective appraisal of scientific reports, which evaluated the relation between perceived overall voice quality and several acoustic-phonetic correlates. Twenty-five studies met the inclusion criteria and were evaluated using meta-analytic techniques. Correlation coefficients between perceptual judgments and acoustic measures were computed. Where more than one correlation coefficient for a specific acoustic marker was available, a weighted average correlation coefficient was calculated. This was the case in 36 acoustic measures on sustained vowels and in 3 measures on continuous speech. Acoustic measures were ranked according to the strength of the correlation with perceptual voice quality ratings. Acoustic markers with more than one correlation value available in literature and yielding a homogeneous weighted r of 0.60 or above were considered to be superior. The meta-analysis identified four measures that met these criteria in sustained vowels and three measures in continuous speech. Although acoustic measures are routinely utilized in clinical voice examinations, the results of this meta-analysis suggest that caution is warranted regarding the concurrent validity and thus the clinical utility of many of these measures.

Local complement activation in nasal polyposis.

OBJECTIVES/HYPOTHESIS: The role of the complement system in nasal polyps (CRSwNP) has so far scarcely been studied. Because nasal polyps are characterized by bacterial colonization, and the complement system is an effective defense mechanism, it might be involved in the pathogenesis of CRSwNP. This study was designed to investigate the local and systemic activation of the complement system in CRSwNP versus control mucosa in relation to the local and systemic eosinophilic and neutrophilic inflammation and local plasma exudation. METHODS: Concentrations of complement factors C3a desArg and C5a desArg, and of albumin, alpha2-macroglobulin, eosinophilic cationic protein, and myeloperoxidase were determined on nasal secretions and serum from 12 CRSwNP patients and 10 control patients. Tissue cryosections were stained for the membrane attack complex (C5b9) RESULTS: We found a significantly higher concentration of C3a desArg and C5a desArg in nasal secretions from CRSwNP patients compared to controls, whereas the serum levels between the two groups did not differ significantly. Significant correlations were found between C5a desArg and eosinophil cationic protein in nasal secretions. Staining for the membrane attack complex revealed a deposition around blood vessels and the basal membrane exclusively in nasal polyp tissue. CONCLUSIONS: These data support the hypothesis that, in addition to the adaptive immune responses, the complement system is involved in the pathogenesis of CRSwNP and may contribute to typical features such as edema and granulocytic inflammation.

Perturbation measures of voice: a comparative study between Multi-Dimensional Voice Program and Praat.

BACKGROUND/AIMS: Frequency and amplitude perturbations are inherent in voice acoustic signals. The assessment of voice perturbation is influenced by several factors, including the type of recording equipment used and the measurement extraction algorithm applied. In the present study, perturbation measures provided by two computer systems (a purpose-built professional voice analysis apparatus and a personal computer-based system for acoustic voice assessment) and two computer programs (Multi-Dimensional Voice Program and Praat) were compared. METHODS: Correlations and inferential statistics for seven perturbation measures (absolute jitter, percent jitter, relative average perturbation, pitch perturbation quotient, shimmer in decibels, percent shimmer, and amplitude perturbation quotient) in 50 subjects with various voice disorders are presented. RESULTS: Results indicate statistically significant differences between the two systems and programs, with the Multi-Dimensional Voice Program yielding consistently higher measures than Praat. Furthermore, correlation analyses show weak to moderate proportional relationships between the two systems and weak to strong proportional relationships between the two programs. CONCLUSION: Based on the literature and the proportional relationships and differences between the two systems and programs under consideration in this study, one can state that one can hardly compare frequency perturbation outcomes across systems and programs and amplitude perturbation outcomes across systems.

TGF-beta signaling and collagen deposition in chronic rhinosinusitis.

BACKGROUND: Chronic rhinosinusitis is an inflammatory disease with distinct cytokine and remodeling patterns. OBJECTIVE: The objective was to analyze the presence of TGF-beta isoforms, receptors, intracellular signaling, and collagen deposition in chronic rhinosinusitis. METHODS: Sinonasal mucosal samples obtained from chronic rhinosinusitis with nasal polyps (CRSwNP; n = 13), chronic rhinosinusitis without nasal polyps (CRSsNP; n = 13), and controls (n = 10) were analyzed for TGF-beta isoforms 1 and 2 by means of ELISA and IHC, and for TGF-beta R1, 2, and 3 by RT-PCR and IHC. As downstream proteins, phospho-Smad 2 (pSmad 2) and collagen were analyzed by performing immunostaining and picrosirius red staining, respectively. RESULTS: TGF-beta 1 and 2 protein concentrations, TGF-beta receptor (R) I and TGF-beta RIII mRNA expression, the number of pSmad 2-positive cells, and total collagen amount were significantly higher in CRSsNP versus controls. In CRSwNP, TGF-beta 1 protein concentration, TGF-beta RII and TGF-beta RIII mRNA expression, the number of pSmad 2-positive cells, and total collagen amount were significantly lower versus controls. Only TGF-beta 2 protein was found higher in CRSwNP versus controls. CONCLUSION: A high TGF-beta 1 protein expression, increased TGF-beta RI expression, and a high number of pSmad 2-positive cells all indicate an enhanced TGF-beta signaling in CRSsNP, whereas a low TGF-beta 1 protein concentration, a decreased expression of TGF-beta RII, and a low number of pSmad 2-positive cells in CRSwNP indicate a low level of TGF-beta signaling in CRSwNP. These findings are compatible with the remodeling patterns observed, reflected by a lack of collagen in CRSwNP, and excessive collagen production with thickening of the collagen fibers in the extracellular matrix in CRSsNP.

Gene profiles of THP-1 macrophages after in vitro exposure to respiratory (non-)sensitizing chemicals: identification of discriminating genetic markers and pathway analysis.

It is recognized that respiratory sensitization is a hazard of high concern. Despite international regulatory requirements there is no established protocol for the identification of chemical respiratory sensitizers. New tests should be based on mechanistic understanding and should be preferentially restricted to in vitro assays. The major goal of this study was to investigate the genetic response of human THP-1 macrophages after contact with respiratory (non-)sensitizers, and to identify genes that are able to discriminate between both groups. THP-1 macrophages were exposed during different time points to 3 respiratory sensitizers, 2 irritants, and 1 skin sensitizer. Gene expression changes were evaluated using Agilent Whole Human Genome arrays. Fisher Linear Discriminant Analysis was used to obtain a ranking of genes that reflects their potential to discriminate between respiratory (non-)sensitizing chemicals. Among the 20 most discriminating genes which were categorized into molecular and biological Gene Ontology (GO) terms, EIF4E, PDGFRB, SEMA7A, and ZFP36L2 could be associated with respiratory sensitization. When categorizing the top-1000 genes into biological GO terms, 24 genes were associated with immune function. Using a pathway analysis tool, platelet-derived growth factor signaling was observed to be activated in THP-1 macrophages in the context of respiratory sensitization.

Chronic rhinosinusitis with and without nasal polyps: what is the difference?

Chronic rhinosinusitis is a heterogeneous group of chronic sinus diseases that may consist of clearly different disease entities. Further investigation of the pathomechanisms of chronic rhinosinusitis and the introduction of appropriate disease markers have recently facilitated disease classification. Evaluation of inflammatory cell profiles, the differentiation of T-effector cells, characterization of remodeling processes such as fibrosis or edema formation, and innate or adaptive immunity products such as Toll-like receptors and immunoglobulins all provide tools to identify distinct disease entities within the group of chronic sinus diseases. This disease differentiation will not only increase our knowledge of the pathophysiology of sinusitis but may lead to new diagnostic and therapeutic strategies specifically targeted and adapted to the diagnosed disease entity.

Enhanced release of IgE-dependent early phase mediators from nasal polyp tissue.

BACKGROUND: The mast cell is a crucial effector cell in allergic rhinitis and other inflammatory diseases. During the acute allergic reaction preformed mediators such as histamine, but also de novo produced mediators such as leukotrienes (LTC4/D4/E4) and prostaglandins (PGD2) are released. Mast cells represent targets for therapeutic intervention, and thus a human ex-vivo model to stimulate mast cells taken from mucosal sites would be instrumental for drug intervention studies. We have aimed to activate mast cells within ex-vivo human nasal tissue by IgE/anti-IgE specific (epsilon chain specific) stimulations and in this respect to test the usability of nasal polyps versus inferior turbinates METHODS: Biopsy samples were collected from patients with nasal polyps and inferior turbinates from patients who underwent sinus or septal surgery. Tissue fragments were primed with IgE 1 mug/ml for 60 minutes and then stimulated for 30 minutes with tissue culture medium (negative control), anti-IgE 10 mug/ml, anti-IgE 30 mug/ml and ionomycin 10 muM (positive control). Histamine, leukotrienes and PGD2 were measured in supernatants. To help provide an understanding of the extent of the response, the number of tryptase and FcepsilonRIalpha positive cells was evaluated by means of immunohistochemistry and the FcepsilonRIalpha-chain was measured by means of quantitative PCR in the nasal polyp and inferior turbinate tissues. Finally, the correlation between IgE concentrations in the nasal tissue and the release of mediators was analysed. RESULTS: Stimulations with anti-IgE on IgE-primed nasal tissue fragments lead to a concentration-dependent release of histamine, leukotrienes and PGD2. The release of these early phase mediators was significantly higher in nasal polyps compared to inferior turbinates, although tryptase, FcepsilonRIalpha positive cells and FcepsilonRIalpha-chain transcripts were equally present in both groups. No correlation was found between baseline concentrations of IgE, and the release of histamine, LTC4/LTD4/LTE4 and PGD2 after stimulation. CONCLUSION: This human nasal challenge model mimics the allergic early phase reaction. The release of histamine, cys-leukotrienes and PGD2 was significantly higher in nasal polyps versus inferior turbinates, however, this observation could not be explained by differences in mast cell or FcepsilonRI+ cell numbers.

THP-1 monocytes but not macrophages as a potential alternative for CD34+ dendritic cells to identify chemical skin sensitizers.

Early detection of the sensitizing potential of chemicals is an emerging issue for chemical, pharmaceutical and cosmetic industries. In our institute, an in vitro classification model for prediction of chemical-induced skin sensitization based on gene expression signatures in human CD34+ progenitor-derived dendritic cells (DC) has been developed. This primary cell model is able to closely mimic the induction phase of sensitization by Langerhans cells in the skin, but it has drawbacks, such as the availability of cord blood. The aim of this study was to investigate whether human in vitro cultured THP-1 monocytes or macrophages display a similar expression profile for 13 predictive gene markers previously identified in DC and whether they also possess a discriminating capacity towards skin sensitizers and non-sensitizers based on these marker genes. To this end, the cell models were exposed to 5 skin sensitizers (ammonium hexachloroplatinate IV, 1-chloro-2,4-dinitrobenzene, eugenol, para-phenylenediamine, and tetramethylthiuram disulfide) and 5 non-sensitizers (l-glutamic acid, methyl salicylate, sodium dodecyl sulfate, tributyltin chloride, and zinc sulfate) for 6, 10, and 24 h, and mRNA expression of the 13 genes was analyzed using real-time RT-PCR. The transcriptional response of 7 out of 13 genes in THP-1 monocytes was significantly correlated with DC, whereas only 2 out of 13 genes in THP-1 macrophages. After a cross-validation of a discriminant analysis of the gene expression profiles in the THP-1 monocytes, this cell model demonstrated to also have a capacity to distinguish skin sensitizers from non-sensitizers. However, the DC model was superior to the monocyte model for discrimination of (non-)sensitizing chemicals.

Gene profiles of a human alveolar epithelial cell line after in vitro exposure to respiratory (non-)sensitizing chemicals: identification of discriminating genetic markers and pathway analysis.

There are currently no accepted biological prediction models for assessing the potential of a substance to cause respiratory sensitization. New tests should be based on mechanistic understanding and should be preferentially restricted to in vitro assays. The major goal of this study was to investigate the alterations in gene expression of human alveolar epithelial (A549) cells after exposure to respiratory sensitizing and non-respiratory sensitizing chemicals, and to identify genes that are able to discriminate between both groups of chemicals. A549 cells were exposed during 6, 10, and 24 h to the respiratory sensitizers ammonium hexachloroplatinate IV, hexamethylene diisocyanate, and trimellitic anhydride, the irritants acrolein and methyl salicylate, and the skin sensitizer 1-chloro-2,4-dinitrobenzene. Overall changes in gene expression were evaluated using Agilent Whole Human Genome 4x44K oligonucleotide arrays. A Fisher linear discriminant analysis was used to obtain a ranking of genes that reflects their potential to discriminate between respiratory sensitizing and respiratory non-sensitizing chemicals. Among the 20 most discriminating genes, which were categorized into molecular and biological gene ontology (GO) terms, CTLA4 could be associated with asthma and/or respiratory sensitization. When categorizing the top-1000 genes into biological GO terms, 22 genes were associated with immune function. Using a pathway analysis tool to identify possible underlying mechanisms of respiratory sensitization, no known canonical signaling pathway was observed to be activated in the A549 cell line.

The current burden of allergic rhinitis amongst primary care practitioners and its impact on patient management.

AIMS: To investigate the burden of allergic rhinitis (AR) amongst primary care practitioners (PCPs), the impact of AR on PCPs' professional lives, and the effect on their management of AR patients of PCPs' personal experience of AR. METHODS: An online questionnaire was completed by 1201 PCPs (50% AR sufferers) from eight countries. RESULTS: 21% of PCPs reported very well controlled symptoms and 66% quite good control. Six hours work per week, on average, was missed by PCPs whose AR symptoms resulted in absence. AR symptoms affected concentration, stress level, mood, time spent with patients, physical contact with patients, and patient throughput. PCPs with AR reported a significantly higher proportion of AR patients in their practice and gave a significantly higher ranking to specific treatment requests and emotional well-being, and gave a significantly lower ranking to preventing comorbidity development and providing a treatment most likely to result in high patient compliance. DISCUSSION: This is the first study demonstrating the impact of AR on PCPs showing association with lost productivity, absenteeism and reduction in professional performance. Personal experience of AR significantly influences PCPs' management of AR and may improve their AR diagnostic ability.