Abstract: BACKGROUND: Asthma is a chronic disease defined by airway inflammation, increased airway hyperresponsiveness and episodes of airway obstruction. Although there are abundant clinical and experimental data showing that stress may worsen asthma, the mechanisms linking stress to asthma are not well understood. By inducing a pro-inflammatory cytokine milieu, stress might enhance airway inflammation in bronchial asthma. We therefore investigated the correlation of stress perception and the cytokine profile of circulating lymphocytes in humans. METHODS: Allergic asthmatic patients and healthy controls were evaluated for perceived level of stress, demographic and lung function data. Whole blood cells were obtained and stimulated by mitogen to assess intracellular IL-4, IFN-gamma and TNF-alpha by flow cytometry. Neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) were measured in serum. RESULTS: Asthmatic patients showed significantly higher percentages of TNF-alpha-producing T cells than healthy controls. Only in asthmatic patients was stress perception correlated with percentages of TNF-alpha-producing T cells and serum BDNF levels, while forced expiratory volume in 1 s (% predicted) was negatively correlated to BDNF. CONCLUSION: The results of our study support the hypothesis that stress deteriorates bronchial asthma by inducing a pro-inflammatory cytokine profile in allergic asthmatics. Stress management might provide a supplement therapy of allergic asthma.
Abstract: BACKGROUND: Neurotrophins are produced by various cells upon different stimuli and participate in the initiation and regulation of inflammation in various diseases including allergy and asthma, but little is known about the production and control of neurotrophins by dendritic cells (DCs). The aim of this study was to assess whether DCs produce the neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), and whether inflammatory stimuli or allergens are able to induce the production of neurotrophic factors. METHODS: Monocyte-derived dendritic cells (MoDCs) were generated from different donors. The neurotrophins NGF and BDNF were demonstrated by RT-PCR, Western blotting, flow cytometry analysis and fluorescence microscopy. MoDCs were cultured and stimulated with lipopolysaccharide (LPS) or allergen for 24 h. The supernatants and cells were collected. Measurement for NGF and BDNF was performed by ELISA. RESULTS: DCs express mRNA for the neurotrophins NGF and BDNF. Proteins were detectable by Western blot, FACS analysis and fluorescence microscopy. LPS led to an up-regulation of BDNF, while NGF was unaffected. Cell lysates demonstrated an increased amount of BDNF after stimulation with LPS or allergen, while NGF was not affected significantly. CONCLUSIONS: DCs are a source of neurotrophins. LPS selectively regulates the production of BDNF. Allergen stimulation leads to an LPS-independent regulation. This contributes to a complex involvement of neurotrophins in allergic diseases.
Abstract: BACKGROUND & OBJECTIVE: Because of environmental concerns CFC-containing pressurised metered dose inhalers (pMDI) had to be replaced by dry powder inhalers (DPI). The Novolizer((R)), a novel DPI has previously been shown to be as effective as the Turbuhaler((R)) in delivering budesonide. The objective of this study was to show non-inferiority of inhaled formoterol therapy delivered through the Novolizer((R)) compared to formoterol delivered through the Aerolizer((R)) in patients suffering from moderate to severe asthma. METHODS: In this double-blind, double-dummy, multicentre study 392 patients were randomised and received a dose of 12mug formoterol twice daily for 4 weeks either through the Aerolizer((R)) or the Novolizer((R)). FEV(1) after 4 weeks of treatment was the primary variable. Secondary variables were FVC, PEF, consumption of short-acting 2 adrenoceptor agonists, asthma symptoms, tolerability and safety. RESULTS: After 4 weeks of treatment, the mean trough FEV(1) (95% CI) was 2.34L (2.24-2.45) for the Novolizer((R)) and 2.31L (2.21-2.41) for the Aerolizer((R)). Non-inferiority was proven (p<0.0001, pre-defined  of 0.25L). All secondary variables (incl. PEF) confirmed these findings. Treatment with both devices was safe and well tolerated. CONCLUSION: Inhalation of 12mug formoterol twice daily via Novolizer((R)) was shown to be equally therapeutically effective compared to the inhalation via Aerolizer((R)) in the treatment of moderate to severe persistent asthma. Treatment via both inhalers was safe and well tolerated.
Abstract: BACKGROUND: Brain-derived neurotrophic factor (BDNF) is a molecule influencing neuronal proliferation and differentiation. In states of allergy, it may orchestrate inflammatory changes by linking the immune system with the nervous system. Because the precise regulation of gene transcription in mast cells MCs is not clear, the present studies assessed the gene regulation of BDNF in this inflammatory cell type. METHODS: Transcriptional expression of BDNF in human skin was studied in isolated cells using RT-PCR. In situ lesional MC BDNF protein expression was analysed by immunohistochemistry and related to the differential staining of MCs and functional effects of BDNF on HaCaT keratinocytes. RESULTS: BDNF mRNA expression was found in isolated human skin MCs, keratinocytes, and fibroblasts. Also, low levels were found in endothelial cells and melanocytes. BDNF protein expression was found in situ in lesional and non-lesional MCs. A significantly decreased expression of BDNF protein was found in atopic dermatitis lesional MCs when compared with control MC expression. Functional in vitro experiments demonstrated that a decrease in BDNF stimulation led to increased secretion rates for stem cell factor and IL-8 in HaCaT keratinocytes. CONCLUSION: The demonstration of a decreased level of BDNF gene transcription in lesional MCs points to a differential regulation of MC-released neutrotrophins in cutaneous allergic inflammation. Topically administered neurotrophin receptor-modulating compounds should be receptor target specific and not universally acting in diseases such as atopic dermatitis or allergic asthma.
Abstract: Background: Omalizumab is an established add-on therapy efficacious in allergic diseases with additional anti-inflammatory activity in the treatment of asthma. The evaluation of responders to anti-IgE treatment is critical to maximize benefit/risk/cost ratio. The aim of the study was to monitor the efficacy of anti-IgE treatment by ex vivo basophil histamine release. Methods: Seventeen patients with allergic asthma were enrolled and received omalizumab at a dose of >/=0.016 mg/kg/IgE every 4 weeks. Histamine release from basophils was evaluated fluorometrically after dose-dependent allergen challenge at baseline and after 16 weeks of treatment. Maximal histamine release and cellular sensitivity to the allergen were calculated. Clinical measurements consisted of body plethysmography, skin prick test, beta(2)-agonist usage, serum free IgE levels, peripheral eosinophils and investigator ratings of global evaluation of treatment effectiveness. Results: Maximal histamine release and cellular sensitivity to the allergen were significantly decreased in the omalizumab group compared to placebo. These changes were accompanied by significant changes in the clinical markers airway resistance, beta-agonist usage, skin prick test wheal area and investigator ratings of global evaluation of treatment effectiveness. Conclusions: Omalizumab therapy decreases basophil histamine release and cellular sensitivity with high effectivity of 95.8% (median). The decline of ex vivo basophil responses does not always parallel individual clinical improvement. Basophil-based stimulation tests should be further evaluated before being regarded as useful parameters monitoring omalizumab therapy. Copyright (c) 2007 S. Karger AG, Basel.
Abstract: BACKGROUND: Neurotrophins are involved in inflammatory reactions influencing several cells in health and disease including allergy and asthma. Dendritic cells (DCs) play a major role in the induction of inflammatory processes with an increasing role in allergic diseases as well. OBJECTIVE: The aim of this study was to investigate the influence of neurotrophins on DC function. METHODS: Monocyte-derived dendritic cells were generated from allergic and non-allergic donors. Neurotrophin receptors were demonstrated by western blotting, flow cytometry and fluorescence microscopy. Activation of small GTPases was evaluated by pull-down assays. DCs were incubated with nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and supernatants were collected for measurement of IL-4, IL-6, IL-10, IL-12p70, TNF-alpha and TGF-beta. RESULTS: Receptor proteins were detectable by western blot, fluorescence activated cell sorting analysis and fluorescence microscopy. Signalling after neurotrophin stimulation occurred in a ligand-specific pattern. NGF led to decreased RhoA and increased Rac activation, while BDNF affected RhoA and Rac activity in a reciprocal fashion. Cells of allergics released a significantly increased amount of IL-6, while for healthy subjects a significantly higher amount of IL-10 was found. CONCLUSION: These data indicate that DCs are activated by the neurotrophins NGF and BDNF by different pathways in a receptor-dependant manner. These cells then may initiate inflammatory responses based on allergic sensitization releasing preferred cytokines inducing tolerance or a T-helper type 2 response.
Abstract: BACKGROUND: Omalizumab is a recombinant monoclonal anti-IgE antibody with proven efficacy in allergic diseases and further anti-inflammatory potency in the treatment of asthma. OBJECTIVES: To explore the anti-inflammatory mechanism of omalizumab, we investigated the induction of immunologic changes leading to eosinophil apoptosis and examined T-lymphocyte cytokine profiles in patients with allergic asthma. METHODS: Nineteen patients with allergic asthma were enrolled and received omalizumab at a dose of at least 0.016 mg/kg/IgE (IU/mL) every 4 weeks. Peripheral eosinophils and T-lymphocyte cytokine profiles were evaluated by fluorescence-activated cell sorting before treatment (baseline), at 12 weeks of treatment, and 12 weeks after discontinuation of treatment with omalizumab or placebo. RESULTS: Markers of eosinophil apoptosis (Annexin V) were significantly increased in omalizumab recipients compared with placebo, whereas no changes in markers of necrosis (7-amino-actinomycin) or eosinophil activation CD69 or Fas receptor (CD95) were detected. GM-CSF+ lymphocytes were reduced in omalizumab recipients compared with placebo. Fewer IL-2+ and IL-13+ lymphocytes were evident in omalizumab recipients than in the placebo group. There were no significant differences in IL-5, IFN-gamma, or TNF-alpha between the omalizumab and placebo groups. CONCLUSION: These findings provide further evidence that omalizumab has additional anti-inflammatory activity demonstrated by induction of eosinophil apoptosis and downregulation of the inflammatory cytokines IL-2 and IL-13. Further studies are needed to determine the underlying mechanisms. CLINICAL IMPLICATIONS: These findings support the critical role of IgE in the regulation of inflammation in allergic asthma: influencing the inflammation is the key to control the more severe type of asthma.
Abstract: BACKGROUND: Omalizumab, a recombinant monoclonal anti-immunoglobulin E (IgE) antibody, shows proven efficacy in the treatment of allergic diseases. A little is known about the immunological pathways affected by the decrease of circulating free IgE during omalizumab treatment. AIM OF THE STUDY: To investigate the immunological consequence of IgE withdrawal, we studied the influence of omalizumab on stimulated IgE-release of cultured peripheral blood mononuclear cells (PBMC) and on the relative number of lymphocytes in the peripheral blood (cellular immune status) in patients with allergic asthma. METHODS: Nineteen patients were enrolled and received omalizumab at a dose of at least 0.016 mg/kg/IgE (IU/ml) every 4 weeks. PBMC were isolated from peripheral blood. Cells were cultured and stimulated with IL-4 (5 ng/ml) and CD40 ligand (1 microg/ml) for 10 days. IgE release was detected in cell culture supernatants by enzyme-linked immunosorbent assay (ELISA). Cellular immune status was investigated by fluorescence-activated cell sorting. RESULTS: Omalizumab treatment induced significant inhibition of stimulated IgE release (median 1.38-0 ng/ml vs. 1.64-2.0 ng/ml in placebo group, P<0.05). B-lymphocyte counts were also significantly lower in the omalizumab group compared with placebo after 12 weeks of treatment (median 18.2-15.6% lymphocytes vs 12.7-13.7% lymphocytes after placebo, P<0.01). There were no significant differences in the other lymphocyte subpopulations between the groups. CONCLUSIONS: These findings provide evidence of immunological influences of omalizumab treatment, leading to a downregulation of IgE secretion and decrease of lymphocyte subpopulations (B-cells) indicating their anti-inflammatory potency.
Abstract: INTRODUCTION: Recent studies have shown that neurotrophins (NTs) are involved in inflammatory processes. Elevated plasma levels of NTs were found allergic diseases with the highest levels in allergic asthma. However, the exact cellular sources involved in the regulation and release of neurotrophins in allergic inflammation are still not well defined. OBJECTIVE: The aim of this study was to assess whether monocytes of allergic and non-allergic subjects produce, store and release the neurotrophins NGF, BDNF and NT-3. METHODS: Monocytes of allergic and non-allergic donors were purified by immunomagnetic selection. APAAP-staining for the presence of NTs and their receptors was performed. RT-PCR and Western blot evaluated the production and storage of NTs. Monocytes were incubated and supernatants were collected for measurement of neurotrophic factors after stimulation with lipopolysaccharide (LPS) as inflammatory stimulus. The neurotrophin content in lysates and cell culture supernatants was determined by ELISA. RESULTS: Human monocytes express the neurotrophins NGF, BDNF and NT-3 but also their specific receptors TrkA, TrkB and TrkC. RT-PCR amplification of isolated mRNA demonstrated expression of the examined neurotrophins. Proteins were detectable by Western blot. NTs were found in the monocyte lysates and supernatants at different levels in allergic and non-allergic donors. Cell stimulation with LPS leads to release of NGF and NT3. CONCLUSIONS: Monocytes, produce, store and release NGF, BDNF and NT-3. They are a possible source of elevated neurotrophin levels found in allergy and asthma.
Abstract: OBJECTIVE: Persistent perennial allergic rhinitis belongs to the most frequent diseases in occupational and environmental medicine. Because the innervation may play a role in the pathogenesis of the disease, the present study analyzed nasal mucosal nerve profiles. METHODS: Neuropeptide-containing nerve fibers were examined using immunohistochemistry and related to eosinophil and mast cell numbers. RESULTS: In contrast to constant numbers of mast cells, there was a significant increase in the number of eosinophils. Immunohistochemistry for calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP), and neuropeptide tyrosine (NPY) revealed abundant staining of mucosal nerves. Semiquantitative assessment of nerve fiber neuropeptide density demonstrated a significant increase of VIP-positive fibers in rhinitis tissues. CONCLUSIONS: The present data indicate a differential regulation of neuropeptide-containing nerve fibers with increased numbers of VIPergic fibers suggesting a modulatory role of the upper airway innervation in perennial allergic rhinitis.
Abstract: BACKGROUND: Recent studies have shown that the neurotrophins NGF and BDNF are produced by eosinophils. The influence of neurotrophins in allergic diseases including asthma has been described. The regulation by pharmacological substance remains unclear. OBJECTIVES: The aim of this study was to assess whether approved pharmacological substances in the treatment of asthma such as corticosteroids or theophylline regulate neurotrophins on a cellular level. METHODS: Eosinophils were purified by negative immunoselection from allergics and non-allergic donors. Eosinophils were incubated with dexamethasone and theophylline and supernatants were collected for measurement of neurotrophic factors. The content of neurotrophins in eosinophil lysates was determined by ELISA. Regulation of stored NGF and BDNF was demonstrated by Western-blotting and flow cytometry while influence on transcription level was demonstrated by RT-PCR. RESULTS: Eosinophils produce and release the neurotrophins NGF and BDNF at different levels in allergics and non-allergics. Dexamethason lead to a significant downregulation of NGF in eosinophils of allergics. The levels of BDNF were not significantly reduced. Theophylline did not influence the levels of NGF nor BDNF significantly. CONCLUSIONS: The production of the neurotrophin NGF was downregulated by an established substance such as dexamethasone. This might further contribute to the pharmacological potential of corticosteroids in allergic asthma.
Abstract: Elevated serum levels of antigen-specific immunoglobulin (Ig)E are often associated with allergic respiratory diseases. This parallel-group, randomised, double-blind, placebo-controlled trial was designed to study the influence of omalizumab on the early nasal response to allergen challenge reflected by symptom score and inflammatory marker levels in nasal lavage fluid (NAL). A total of 23 patients with allergic rhinitis took part in the study, 11 were given placebo and omalizumab was administered subcutaneously in 12. Omalizumab or placebo were given at 2- or 4-week intervals based on a patient's body weight and IgE levels to a total dose of 0.016 mg x kg(-1) x IgE(-1) (IU x mL(-1)) every 4 weeks. Compared to placebo, 16 weeks of treatment with omalizumab significantly inhibited allergen challenge-induced nasal symptoms (median symptom score 7.0-0.5 versus 7.0-7.0) and inhibited the increase of human serum albumin (median 15.3-0.12 mg x mL(-1) versus 8.2-19.7 mg x mL(-1)) in the NAL after allergen challenge. Treatment with omalizumab induced a significant decrease in tumour necrosis factor-alpha levels in basal NAL, but no change was seen for histamine. These results indicate that subcutaneously administered monoclonal anti-immunoglobulin-E antibody, omalizumab, inhibits the nasal responses to allergen challenge of patients with allergic rhinitis. Omalizumab may provide a new strategy for the treatment of allergic rhinitis.
Abstract: BACKGROUND: Allergic rhinitis (AR) is the most common allergic disease affecting the respiratory tract. Next to inflammatory changes, the airway innervation plays an important modulatory role in the pathogenesis of the disease. OBJECTIVE: To examine the participation of different neuropeptides in the human nasal mucosa of intermittent (seasonal) AR tissues in the allergic season. METHODS: Immunohistochemistry for substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and neuropeptide tyrosine (NPY) was related to the characterization of inflammatory cells in tissues of patients with seasonal AR (n=18). RESULTS: While there was a significant increase in the number of eosinophils present if compared with a control group, no changes occurred in mast cell numbers. Immunostaining was abundantly found in different nerve fibre populations of both groups. SP expression was significantly increased in mucosal nerve fibres of patients with intermittent (seasonal) AR. Also, significantly increased numbers of VIP- and NPY-immunoreactive nerve fibres were found in biopsies of rhinitis patients in comparison with sections of normal human nasal mucosa. In contrast, CGRP expression did not change significantly. CONCLUSION: The increase of neuropeptide expression in mucosal nerve fibres indicates a major role of the autonomous mucosal innervation in the pathophysiology of intermittent (seasonal) AR.
Abstract: BACKGROUND: Recent studies have shown that neurotrophins are produced by and can act on several immune-inflammatory cells. The origin of circulating as well as local neurotrophins is unknown. OBJECTIVES: The aim of this study was to assess whether eosinophils of allergic and non-allergic donors produce, store and release the neurotrophic factors NGF, BDNF and NT-3. METHODS: Eosinophils were purified by negative immunoselection (purity > 96%) from allergic asthmatics and non-allergic donors (25 to 53 years). The presence of mRNA for neurotrophic factors was evaluated by reverse transcription PCR. Specificity was demonstrated by cloning products and sequencing. Stored NGF, BDNF and NT-3 was demonstrated by Western-blotting and flow cytometry. Eosinophils were incubated and supernatants were collected for measurement of neurotrophic factors after cell stimulation with PAF. Neurotrophin content in eosinophil lysates was determined by ELISA. RESULTS: Eosinophils demonstrate mRNA for neurotrophins. Proteins were detectable by Western blot and FACS analysis. Neurotrophins were found in the eosinophil lysates at different amounts comparing allergic and non-allergic donors. Cell stimulation with PAF (10-8-10-5 M) after priming with GM-CSF leads to a dose-dependant release of NGF and BDNF. CONCLUSIONS: Eosinophils store, produce and release NGF, BDNF and NT-3. They are a possible source of elevated neurotrophin levels found in allergy and asthma.
Abstract: BACKGROUND/OBJECTIVES: The mechanical aerosol generator, MAGhaler, is a new chlorofluorocarbon-free inhalation device. The objective of this trial was to show equivalent efficacy and safety of beclomethasone dipropionate (BDP) delivered via the MAGhaler and the metered-dose inhaler (MDI) in patients with mild to moderate bronchial asthma. Moreover, user-friendliness and acceptance of the two devices were compared. METHODS: This was a double-blind, reference-controlled, 12-week trial in 171 patients with asthma receiving BDP (1,000 microg/day) delivered via either the MAGhaler or the conventional MDI. Respiratory function parameters, clinical symptoms, concomitant intake of salbutamol or fenoterol, adverse events (AEs), laboratory values, and concomitant medications and diseases were recorded. The primary efficacy parameter was mean forced expiratory volume in 1 s (FEV1), measured after 4, 8, and 12 weeks of therapy. RESULTS: The equivalence of the two devices was confirmed (p = 0.003) on the basis of the ratios of the mean FEV1 in weeks 4 to 12. Mean (+/- SD) FEV1 (MAGhaler was 2.24 +/- 0.60 l (baseline), 2.61 +/- 0.90 litres (week 4), and 2.62 +/- 0.87 litres (weeks 4-12). Mean FEV1 (MDI) was 2.28 +/- 0.59 litres (baseline), 2.53 +/- 0.82 litres (week 4), and 2.56 +/- 0.77 litres (weeks 4-12). In total, 33 AEs occurred in 26 (30.2%) patients (MAGhaler) and 51 AEs in 36 (42.4%) patients (MDI). Most of the AEs were of mild or moderate intensity. The relationship to treatment could not be excluded for 11 AEs in 11 patients (MAGhaler) and 23 AEs in 18 patients (MDI). Three serious AEs, all unrelated to treatment, occurred in 3 patients (MAGhaler: 2, MDI: 1). There were no clinically relevant changes in other safety parameters. Most patients either preferred the MAGhaler or rated the two devices as equally acceptable. CONCLUSION: The new MAGhaler was equivalent to the standard MDI in terms of the safety and efficacy of BDP. The improved user-friendliness and acceptance of the MAGhaler over the conventional MDI represent an important advance in the clinical management of bronchial asthma.
Abstract: IgE plays a key role in allergic asthma. We investigated whether omalizumab treatment of patients with moderate to severe allergic asthma leads to changes in inflammatory mediators and clinical symptoms. This sub-study was conducted on 35 patients with a positive skin prick test (SPT) requiring daily administration of beclomethasone dipropionate (500-1,000 microg), who participated in a multicentre, randomised, double-blind, placebo-controlled study. Omalizumab or placebo was administered at 0.016 mg/kg/IgE every 4 weeks. Patients recorded peak expiratory flow, asthma symptom score and beta(2)-agonist use in daily diaries and spirometry was performed at each visit. beta(2)-Agonist use and SPT wheal reaction decreased significantly (p < 0.05). Circulating levels of IL-5, IL-6, IL-8, IL-10, IL-13 and s-ICAM were measured before and after 16 weeks of treatment. IL-13 and s-ICAM were measured before and after 16 weeks of treatment. IL-13 decreased significantly (p < 0.01). IL-5 and IL-8 decreased in the omalizumab group compared to baseline. The other circulating mediators did not demonstrate any changes. Histamine release was significantly reduced (p < 0.01). Airway resistance (p < 0.05) and the provocative concentration inducing a 20% decrease in FEV(1) (p < 0.05) were measured before, after 16 weeks, and 3 months after completion of treatment. Both parameters decreased significantly (p < 0.05). Peripheral eosinophil count decreased significantly compared to placebo (p < 0.01). These findings suggest that omalizumab has potential as a novel treatment for allergic asthma.
Abstract: BACKGROUND: Recent studies have shown that nerve growth factor (NGF) can act on several immune cells as well as residential cells. But little is known about their role in modulating eosinophil function via activation of high-affinity receptors. OBJECTIVES: The aim of this study was to assess whether eosinophils express functional receptors and if their function is influenced by NGF, brain-derived neurotrophic factor (BDNF) or neurotrophin-3 (NT-3). METHODS: Eosinophils were purified by negative immunoselection (purity > 96%). High-affinity neurotrophin receptors were demonstrated by reverse transcription polymerase chain reaction, western blotting and flow-cytometry analysis. Functionality of receptors was demonstrated by receptor phosphorylation after ligand binding. Eosinophils were incubated with NGF, BDNF and NT-3, and cells and supernatants were collected for measurement of the mediators IL-4, IL-5, IL-8, transforming growth factor (TGF)-beta1, eosinophil cationic protein (ECP), eosinophil protein X (EPX) as well as eosinophil viability. RESULTS: Eosinophils expressed mRNA for neurotrophin receptors. Proteins were detectable by western blot and fluorescent-activated cell sorter analysis. The receptors were phosphorylated after stimulation with neurotrophins. After NGF stimulation, a significant increase in IL-4 was detectable. BDNF and NT-3 stimulation led to a significant increase in EPX. Eosinophil viability was not influenced. CONCLUSIONS: Eosinophils express the functionally active receptors TrkA, TrkB and TrkC. Receptor activation stimulates eosinophils. This might be an additional pathway regulating inflammatory responses in allergic reactions.
Abstract: The ability of omalizumab, an anti-immnoglobulin-E agent, to maintain long-term disease control in patients with moderate-to-severe allergic asthma was investigated in a 24-week double-blind extension to a 28-week core trial. During the extension, 483 of the initial 546 patients were maintained on randomised treatment and the lowest sustainable dose of beclomethasone dipropionate (BDP) as established during the steroid-reduction phase of the core trial. The use of concomitant asthma medication was permitted and investigators were allowed to adjust the BDP dose or switch patients from BDP to other asthma medications if deemed necessary. More omalizumab-treated patients (33.5%) than placebo-treated patients (13.5%) were able to complete the extension period without requiring inhaled corticosteroid treatment. The mean BDP equivalent dose throughout the extension was lower in the omalizumab group (25 microg x day(-1)) than in the placebo group (43 microg x day(-1)). Disease control was sustained in 76% of omalizumab patients compared with 59.4% of placebo patients free from an asthma exacerbation during the extension period. Compared with placebo, fewer patients in the omalizumab group used other concomitant asthma medication during the extension. Treatment with omalizumab was well tolerated and the incidence of adverse events was similar between groups. In conclusion, these results suggest that omalizumab is a promising new agent for the long-term control of allergic asthma.
Abstract: BACKGROUND: The neurotrophins Nerve Growth Factor (NGF), Brain-Derived Neurotrophic Factor (BDNF) and Neurotrophin (NT)-3 are produced, stored and released by various immunological cells. The influence of NTs upon the function of these cells is described. Elevated plasma levels were found in inflammatory, autoimmune and allergic diseases with the highest levels in allergic asthma. A connection between bronchial hyper-responsiveness and serum levels has been reported. OBJECTIVE: Little is known about the influence of treatment with inhaled corticosteroids (ICS) on serum NT levels and their influence on the asthmatic state. METHODS: Eighty-seven volunteers were studied. Thirty-eight were stable allergic asthmatics with constant ICS doses, 29 were asthmatics not receiving anti-asthmatic treatment and 20 were age- and sex-matched healthy controls. Demographic and lung function data were evaluated. NT serum levels were determined by ELISA. RESULTS: NGF and BDNF levels were significantly increased in untreated asthmatics compared to the control and the treated group, while NT-3 demonstrated significantly higher levels in treated asthmatics compared to healthy controls. After stabilization of untreated subjects with ICS, the NT levels decreased significantly. CONCLUSIONS: These results suggest that NTs participate in allergic inflammation and asthma. Effective treatment leads to a decrease of circulating neurotrophic factors.
Abstract: OBJECTIVE AND DESIGN: There is evidence that substance P (SP) is involved in events related to allergic and nonallergic rhinitis. Furthermore, some effects of SP seem to be greater in subjects suffering from allergic rhinitis than in nonallergic subjects. To investigate if these effects may be partly mediated by histamine release (HR) we studied the influence of SP on HR from nasal mucosa of subjects with and without allergic rhinitis using an in vitro organ culture system. SUBJECTS: Nasal mucosa of the inferior turbinate was obtained from ten patients suffering from allergic rhinitis and eighteen non-allergic subjects receiving surgical therapy for nasal obstruction. METHODS: Tissue samples of nasal mucosa were stimulated with 10(-5) M SP or with 10(-5) M Ca-ionophore A23187 for 120 minutes, and the histamine content was determined in the culture supernatant. RESULTS: Both SP and Ca-ionophore A23187, caused a significantly higher HR from the samples of the non-allergic group (p < 0.01) compared to baseline controls (spontaneous release). The same effect was seen in the allergic group (p < 0.01 and p = 0.036). Comparing the increase in HR from allergic and non-allergic mucosa, in allergics the HR stimulated by SP was significantly higher (p = 0.031), whereas Ca-ionophore A23187 did not show this effect. CONCLUSION: These findings suggest a role of SP in inducing release of histamine from human nasal mucosa, thereby influencing physiologic and pathophysiologic nasal conditions, especially in allergic inflammatory processes.
Abstract: BACKGROUND: In a recent study mast cell heparin proteoglycan (HepPG) of a cell line derived from a mouse mastocytoma was isolated. Glycosaminoglycans proved to be an initiating surface for starting contact activation and could explain kinin generation present in allergic reactions. It is the aim of the present study to prove that HepPG or glycosaminoglycan derived from human mast cells is also capable of acting as a physiologic macromolecule and to induce contact activation. METHODS: HepPG molecules were isolated by anionic column chromatography. Their ability to accelerate reciprocal activation of factor XII was investigated by spectrophotometry. The anticoagulant effect was demonstrated by an increase in partial thromboplastin time. HPLC was performed to correlate these effects with molecular weight (MW). RESULTS: The isolated heparin showed high contact-activating and anticoagulant potency. Both actions were suppressed by incubation with heparinase I. The maximum contact activation peak appeared at a lower MW than the anticoagulant effect. CONCLUSION: These in vitro results explain the results of in vivo allergen challenge studies where a high degree of kinin generation occurs. Heparin derived from human mast cells therefore seems to represent the physiological macromolecule capable of activating the contact system and could be a missing link between cellular and humoral responses in allergic reactions.
