Relationships between allergic inflammation and nasal airflow in children with seasonal allergic rhinitis.

BACKGROUND: Allergic rhinitis is characterized by a T(H)2-dependent inflammation. Nasal obstruction is a typical symptom of allergic rhinitis. OBJECTIVE: To evaluate the possible relationships among nasal symptoms, allergic inflammation, including inflammatory cells and cytokine pattern, and nasal airflow in children with seasonal allergic rhinitis. METHODS: Children with seasonal allergic rhinitis and moderate-severe nasal obstruction were evaluated during the pollen season. Total symptom score, rhinomanometry, nasal lavage, and nasal scraping were evaluated in all patients. Inflammatory cells were counted by conventional staining; interleukin 5 (IL-5) and IL-8 levels were measured by immunoassay on fluids recovered from nasal lavage. RESULTS: Twenty children (11 boys and 9 girls; mean +/- SD age, 12.9 +/- 1.7 years) participated in this study. Eosinophil levels were significantly associated with total symptom score (r = 90.6%, P < .001), IL-5 (r = 94.9%, P < .001), and nasal flow (r = -93.6%, P < .001). No association was elicited with IL-8 (r = 9.4%, P = .69). In a multivariate analysis that included eosinophils, neutrophils, and IL-5, eosinophil levels were shown to be the only independent predictor of nasal flow. CONCLUSIONS: This study demonstrates the close connection between T(H)2 cytokines and eosinophil infiltration. In addition, there is clear evidence concerning the relationship among nasal symptoms, eosinophil infiltration, and nasal airflow. These findings constitute evidence of the relationship between nasal airflow impairment and eosinophilic inflammation in children with seasonal allergic rhinitis.     

Changes in airway inflammation following nasal allergic challenge in patients with seasonal rhinitis

BACKGROUND: Seasonal allergic rhinitis could predispose to the development of chronic bronchial inflammation as observed in asthma. However, direct links between nasal inflammation, bronchial inflammation and airway responsiveness in patients with seasonal allergic rhinitis and without asthma are not fully understood. The aim of this study was to analyse the changes induced by allergic nasal challenge outside the pollen season in airway responsiveness and bronchial inflammation of patients with seasonal allergic rhinitis. METHODS: Nine patients were evaluated after either grass pollens or placebo nasal challenge in a randomized cross-over double-blinded trial. Nasal parameters were recorded hourly and airway responsiveness was assessed by methacholine challenge. Cytological examinations and cytokine measurements were performed in nasal lavage and induced sputum. Eosinophil activation was investigated by eosinophil-cationic protein expression and secretion. RESULTS: Airway responsiveness was increased after allergic nasal challenge. Total eosinophils and eosinophils expressing eosinophil-cationic protein were increased in induced sputum after allergic nasal challenge. Both eosinophil number and eosinophil-cationic protein concentration in induced sputum were correlated to methacholine responsiveness. CONCLUSIONS: These results suggest that eosinophils participate to the bronchial inflammation in patients with seasonal allergic rhinitis following allergic nasal challenge outside the pollen season and might explain changes in airway responsiveness.     

Airway function and nasal inflammation in seasonal allergic rhinitis and asthma

BACKGROUND: Allergic rhinitis (AR) and asthma are frequently associated and characterized by a Th2-dependent inflammation. Nasal and bronchial obstruction may be objectively measured. OBJECTIVE: The aim of this study was to evaluate the relationships among upper and lower airway function and nasal inflammation in subjects with seasonal allergic rhinitis (SAR) and asthma. METHODS: Twenty out-patients (12 males and eight females, mean age: 23.4+3.6 years) with SAR and asthma were evaluated during the pollen season. All of them showed a moderate-severe grade of nasal obstruction. Total symptom score, rhinomanometry, spirometry, nasal lavage, and nasal scraping were obtained in all subjects. Eosinophils were counted by conventional staining; IL-4 and IFN-gamma were measured by immunoassay on fluids recovered from nasal lavage. RESULTS: Functional parameters, i.e. nasal airflow and forced expiratory volume in 1 s (FEV(1)), were correlated with nasal eosinophils (R(2)>0.83, P<0.001). Inflammatory parameters, i.e. eosinophils were correlated with immunological parameters, i.e. IL-4 and IFN-gamma levels (R(2)=0.93, P<0.001). Nasal symptoms were correlated with nasal airflow (rho=-0.71, P< or =0.01) and eosinophils (rho=0.72, P<0.01). Nasal airflow was correlated with FEV(1) (r=0.89, P<0.0001). CONCLUSIONS: This study demonstrates the close connection between Th2 cytokines and eosinophil infiltration in the nose. There is also clear evidence concerning the relationships between eosinophils infiltration and cytokines levels. Nasal eosinophils can be regarded as the most important predictors of upper and lower airway functions. These findings constitute first evidence of a relationship among nasal Th2-related inflammation and nasal and bronchial airflow in patients with SAR and asthma.     

Relationships between allergic inflammation and nasal airflow in children with persistent allergic rhinitis due to mite sensitization

BACKGROUND: Allergic rhinitis is associated with Th2-dependent inflammation. Nasal obstruction is the most typical symptom in children with mite allergy. OBJECTIVES: The aim of this study was to evaluate the possible relationships among nasal symptoms, allergic inflammation, including inflammatory cells and cytokine pattern, and nasal airflow in children with persistent allergic rhinitis because of mite sensitization. METHODS: Twenty children (13 males and seven females, mean age 13.4 +/- 1.6 years) with persistent rhinitis because of mite allergy were evaluated. All of them had moderate-severe grade of nasal obstruction. Total symptom score (TSS), rhinomanometry, nasal lavage, and nasal scraping were obtained in all subjects. Inflammatory cells were counted by conventional staining; interleukin (IL)-5, and IL-8 were measured by immunoassay on fluids recovered from nasal lavage. RESULTS: Eosinophils were significantly associated with TSS (R = 74.4%, P = 0.0002), with IL-5 (R = 90.6%, P < 0.0001) and with nasal flow (R = -69%, P = 0.0007), but not with IL-8 (R = 0.1%, P = 0.995). Eosinophil levels were shown to independently predict nasal flow (P < 0.001), with flow decreasing linearly for increasing eosinophils, together with a significant effect of neutrophils (P = 0.016, linear increase in flow) and a borderline effect of IL-8 (P = 0.063, linear increase in flow). CONCLUSIONS: This study demonstrates the close association between IL-5 concentration and eosinophil infiltration. In addition, there is clear evidence concerning the relationship between eosinophil infiltration and nasal airflow. Thus, nasal eosinophils can be regarded as the most important predictor of upper airway function. These findings constitute first evidence of the relationship between nasal airflow impairment and Th2-related eosinophilic inflammation in children with persistent allergic rhinitis because of mite sensitization.     

Effects of allergic inflammation of the nasal mucosa on the severity of rhinovirus 16 cold

BACKGROUND: Despite the strong association of asthma exacerbations with rhinovirus (RV) infection, inoculation of asthmatic subjects with RV only causes small changes in lower airway function, suggesting that RV infection is not itself sufficient to provoke asthma exacerbations. OBJECTIVE: Our purpose was to test whether allergic inflammation increases the airway response to RV infection. METHODS: We compared the severity of RV type 16-induced colds in 2 groups of 10 subjects with allergic rhinitis. One group received 3 nasal challenges with allergen and the other received challenges with placebo over the week before nasal inoculation with RV type 16 (4000 tissue culture infective dose 50% per subject). Subjects kept symptom diaries and were assessed with spirometry, methacholine challenge, nasal lavage, and sputum induction on days 2, 4, 7, 10, 15, and 30 after inoculation. RESULTS: The 2 groups developed equal rates of infection (90%), similar cold symptoms (Jackson score median [interquartile range], 11 [6-33] vs 20.5 [6-42] for allergen and placebo groups respectively, P =.54), and similar changes in cellular profile and in IL-6 and IL-8 concentrations in nasal lavage fluid and induced sputum after RV inoculation. The incubation period was significantly longer in the allergen group (2.5 [1-5.5] vs 1 [1-1] day, P =.03) and the duration of cold symptoms was shorter (5 [4-7] vs 8.5 [6-10] days, P =.008). We also found an inverse correlation between the percent of eosinophils in nasal lavage fluid before inoculation and the severity of cold symptoms (r = -0.58, P =. 008). CONCLUSION: In subjects with allergic rhinitis, augmented nasal allergic inflammation before inoculation with RV type 16 does not worsen the severity of cold symptoms but delays their onset and shortens their duration.     

Nasal obstruction in patients with seasonal allergic rhinitis: relationships between allergic inflammation and nasal airflow

BACKGROUND: Nasal obstruction is a typical symptom of allergic rhinitis. Allergic rhinitis is characterized by a Th2-dependent inflammation. The aim of this study was to evaluate the possible relationships between allergic inflammation, including inflammatory cells and cytokine pattern, and nasal airflow in patients with nasal obstruction due to seasonal allergic rhinitis. METHODS: Fifty patients (31 males and 19 females, mean age 31.9 +/- 4.8 years) with seasonal allergic rhinitis were evaluated during the pollen season. All of them had moderate to severe nasal obstruction. Total symptom score, rhinomanometry, nasal lavage, and nasal scraping were assessed in all subjects. Inflammatory cells were counted by conventional staining; IL-4, IL-5, IL-8, and IFNgamma were measured by immunoassay on fluids recovered from nasal lavage. RESULTS: Significant positive relationships were demonstrated between eosinophil infiltration and IL-4 levels (p < 0.0001), eosinophils and IL-5 levels (p < 0.0001), and eosinophils and IL-8 levels (p < 0.0001). Significant negative relationships were demonstrated between eosinophil infiltration and IFNgamma levels (p < 0.0001) and eosinophil infiltration and nasal airflow (p < 0.001). CONCLUSIONS: This study demonstrates the close connection between Th2 cytokines and eosinophil infiltration. In addition, there is clear evidence concerning the relationship between eosinophil infiltration and nasal airflow. These findings constitute first evidence of the relationship between nasal airflow impairment and Th2-related inflammation in seasonal allergic rhinitis.     

Induced sputum: comparison of postinfectious cough with allergic asthma in children

BACKGROUND: Cough persisting after a respiratory infection is common in children and is often managed as asthma. However, little is known about the pathophysiologic mechanisms of such cough and how it compares with asthma. OBJECTIVE: We used the technique of induced sputum to examine the inflammatory index values associated with persistent cough or allergic asthma in children. We hypothesized that the sputum from children with persistent postinfectious cough would differ from that of children with allergic asthma in that the former would lack eosinophils compared with the latter.Study design: Sputum production was induced with hypertonic saline solution in 34 children: 12 with cough persisting for 1 month or more after an apparent respiratory tract infection, not treated with corticosteroid; 11 with untreated atopic asthma, not using inhaled corticosteroid; and 11 with treated atopic asthma using inhaled corticosteroid. RESULTS: The percentage of eosinophils in the sputum of children with cough was significantly lower than in the sputum of children with untreated allergic asthma (median 0.5% vs 14.5%, P <.0001). Similarly, the percentage of eosinophils in the sputum of children with asthma treated with inhaled steroids was significantly lower compared with untreated asthmatic children (1.5% vs 14.5%, P <.0001). The peripheral blood eosinophils, serum eosinophil cationic protein, and nasal percent eosinophils of the patients with cough were also significantly lower than those from patients with untreated asthma. Methacholine challenge in 6 of the 11 cough patients tested showed mild-to-moderate hyperresponsiveness, whereas the other 5 had a negative methacholine challenge. CONCLUSIONS: Children with persistent postinfectious cough do not have airway eosinophilia typical of untreated asthma. Despite the absence of eosinophilic inflammation, some of the patients with chronic cough had reactive airways. These results suggest that postinfectious cough in children has different pathophysiologic features than allergic asthma and probably represents a different disease.     

Correlation of nasal inflammation and nasal airflow with forced expiratory volume in 1 second in patients with perennial allergic rhinitis and asthma.

BACKGROUND: Allergic rhinitis and asthma are frequently associated and are characterized by TH2-dependent inflammation. Nasal and bronchial obstruction largely depend on allergic inflammation. OBJECTIVE: To evaluate the relationships among nasal eosinophil counts, interleukin 4 (IL-4) and interferon-gamma (IFN-gamma) levels, nasal airflow, and forced expiratory volume in 1 second (FEV1) in patients with perennial allergic rhinitis and asthma. METHODS: Eight men and 7 women (mean +/- SD age, 24.8 +/- 4.7 years) with perennial allergic rhinitis and asthma were evaluated. All 15 patients had a moderate-to-severe grade of nasal obstruction. Total symptom score, rhinomanometry, nasal lavage, nasal scraping, and spirometry were evaluated in all patients. Eosinophils were counted using conventional staining; IL-4 and IFN-gamma levels were measured by immunoassay in fluids recovered from nasal lavage. RESULTS: Significant positive relationships were demonstrated between eosinophil infiltration and IL-4 levels, nasal airflow and IFN-gamma levels, FEV1 and IFN-gamma levels, and nasal airflow and FEV1 (P < .001 for all). Significant negative relationships were demonstrated between eosinophil infiltration and IFN-gamma levels, IL-4 and IFN-gamma levels, eosinophil infiltration and nasal airflow, IL-4 values and nasal airflow, nasal eosinophil counts and FEV1, and IL-4 values and FEV1 (P < .001 for all). CONCLUSIONS: There is a close association between TH2 cytokines and eosinophil infiltration in the nose. There is also clear evidence concerning the relationships among eosinophil infiltration, IL-4 and IFN-gamma levels, and nasal airflow. Nasal eosinophil, IL-4, and IFN-gamma levels correlate with FEV1. Finally, nasal airflow is related to FEV1. These findings constitute the first evidence of a relationship between TH2-related nasal inflammation and nasal and bronchial airflow in patients with perennial allergic rhinitis and asthma.     

The effect of immediate‐hypersensitivity reactions on the level of SLPI, granulocyte elastase, α1‐antitrypsin, and albumin in nasal secretions, by the method of unilateral antigen challenge

BACKGROUND: The aim of this paper was to investigate the role of SLPI in patients with allergic rhinitis. From this point of view, we also examined leukocyte elastase, alpha1-antitrypsin, and albumin. SLPI is an inhibitor of serine proteases such as leukocyte elastase, cathepsin G, and mast-cell chymase. Since chymase is considered to participate in mast-cell degranulation and histamine release, SLPI might act as a regulator of allergic reactions. Recent interest has been focused on leukocytes and allergy. Since SLPI is a strong inhibitor of leukocyte elastase, we also focused on the function of elastase in allergic rhinitis. METHODS: We used the method of nasal lavage after unilateral nasal antigen challenge in atopic and healthy subjects. The ELISA quantified SLPI and elastase. Albumin and alpha1-antitrypsin were quantified by electroimmunoassay. Gel filtration was used to separate native SLPI from its complex with elastase. RESULTS: There was a higher level of SLPI in lavage fluid from healthy subjects than from atopic patients. SLPI was increased on the contralateral side in atopic subjects after allergen challenge. The absence of increase in SLPI on the challenged side may be attributed to the increase in elastase and its binding to SLPI, which might have an effect on the immunoreactivity and interfere with the ELISA. It may then be assumed that there is an augmentation of SLPI on the challenged side as well. No increase was seen in healthy subjects. There was a higher concentration of elastase, alpha1-antitrypsin, and albumin before antigen challenge in atopic patients outside the pollen season than in healthy subjects. As expected, an increase was also seen in the challenged side exclusively in atopic subjects. CONCLUSIONS: The lower concentration of SLPI in nasal lavage fluid among the atopic patients than the healthy subjects indicates damaged mucosa. Neural reflexes are involved in SLPI release since there was an increase even in the contralateral nostril. A higher level of elastase and albumin before allergen challenge suggests chronic inflammation in nasal mucosa outside the pollen season. Leukocyte recruitment takes place in response to IgE-mediated reactions, which are reflected in an increase in elastase in response to allergen challenge.     

Nasal inflammation and bronchial reactivity to methacholine in atopic children with respiratory symptoms

BACKGROUND: In atopic subjects, dysfunctions of the upper and lower airways frequently coexist and allergic rhinitis seems to constitute a risk factor for the occurrence of asthma in predisposed individuals. AIM OF THE STUDY: To evaluate whether in atopic subjects nasal inflammation could reflect changes in respiratory functions, 11 allergic children, sensitized to house dust mites (HDM), with rhinoconjunctivitis and asthma and 10 nonatopic controls (ctrs) were studied. METHODS: All subjects underwent nasal brushing to detect percentages of nasal eosinophils (Eos %) and intercellular adhesion molecule-1 (ICAM-1) expression by nasal epithelial cells. In the same day pulmonary function tests, i.e. forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), forced expiratory flows at 25-75% of the vital capacity (FEF25-75%) and methacholine (MCh) bronchial inhalation challenge were also evaluated. RESULTS: Pulmonary function parameters were not significantly different in allergic children and in ctrs (P > 0.05), while a significant increase in bronchial reactivity to MCh, expressed as Pd20 MCh, was detected in the former population (P < 0.05). As compared with ctrs, allergic children showed elevated Eos % and ICAM-1 expression (P < 0.05). When nasal inflammation and pulmonary function parameters were compared, a significant correlation was found between nasal Eos % and bronchial reactivity to MCh (P = 0.002). CONCLUSIONS: These data support the concept of significant links between upper and lower respiratory tract involvement in atopic children sensitized to HDM.     

The effect of recombinant interleukin-8 on eosinophils' and neutrophils' migration in vivo and in vitro

BACKGROUND: Interleukin-8 (IL-8) is a chemokine that causes chemotaxis of neutrophils, eosinophils and lymphocytes in vitro; however, its role as a chemoattractant in allergic inflammation is unclear. The objective of this study was to investigate the effect of nasal instillation of IL-8 on the influx of inflammatory cells. METHODS: Twelve patients suffering from seasonal allergic rhinitis hypersensitive to grass pollens, with average age 30.1 +/- 2.67 years were challenged both with diluent for IL-8 and IL-8 on a subsequent day, in two phases: before the pollen season (unprimed mucosa) and during the season (primed mucosa). The number of neutrophils, eosinophils and myeloperoxydase (MPO) levels in the nasal fluid collected after IL-8 or placebo challenge were determined. RESULTS: Challenge with IL-8 of primed nasal mucosa induced a significant influx of neutrophils (29 x 10(4) cells/ml at 0.5 h, 251 x 10(4) at 2 h and 334 x 10(4) at 3 h). Number of eosinophils in comparison with diluent challenge was not significant. There was no difference in MPO levels in the nasal lavage between IL-8 and diluent challenge of unprimed and primed mucosa. We did not find the relationship between MPO levels and the neutrophils number in the lavage (rank Spearman factor, RS = 0.258, P = 0.42). CONCLUSION: We have demonstrated that IL-8 causes influx of neutrophils but not eosinophils into nasal mucosa in vivo. MPO level seems to be of little value as a marker of neutrophil influx into nasal mucosa.     

An eosinophil-Sos1-RAS axis licenses corticosteroid resistance in patients with allergic rhinitis

BackgroundCorticosteroid resistance (CR) is a serious disadvantage in treating many chronic inflammatory conditions. Eosinophils are the main inflammation cells in allergic reactions. Environmental pollution, such as PM2.5, is associated with the pathogenesis of allergic disorders. The objective of this study is to elucidate the mechanism by which the exposure to PM2.5 confers eosinophil CR status.MethodsPatients with allergic rhinitis were recruited and assigned to corticosteroid sensitive (CS) and CR groups. Eosinophils were purified from nasal lavage fluids collected from patients with allergic rhinitis. A murine AR mouse model was developed with dust mite allergens and PM2.5 as the sensitization reagents.ResultsCR status was detected in about 60% eosinophil collected in patients with AR. Upon exposure to eosinophil activators, CS eosinophils released a large quantity of mediators, which was suppressed by the presence of steroids in the culture. CR eosinophils demonstrated resistance to steroidal therapy. RAS activation levels in eosinophils were higher in CR eosinophils than in CS eosinophils. Higher expression of the Son of sevenless-1 (Sos1) was detected in CR eosinophils, which formed a complex with RAS and glucocorticoid receptor-α in CR eosinophils to prevent the binding between steroids and glucocorticoid receptor-α. The presence of an Sos1 inhibitor dissociated glucocorticoid receptor-α from RAS/Sos1 complex, that restored the sensitivity to steroids in eosinophils. Administering the Sos1 inhibitor effectively attenuated the experimental allergic rhinitis.ConclusionsCR status was detected in approximately 1/3 eosinophils sampled from patients with allergic rhinitis. Sos1 was instrumental in the development and perseverance of CR in eosinophils. Sos1 inhibition restored sensitivity to steroids in CR eosinophils, which effectively reduced experimental allergic rhinitis.     

Nasal lavage fluid concentrations of eotaxin-1 (CCL11) in naturally occurring allergic rhinitis: relationship to disease activity, nasal luminal eosinophil influx, and plasma protein exudation

BaCKGROUND: Eotaxin-1 (CCL11) is a CC chemokine whose nasal eosinophilic chemotactic activity in vivo and in vitro has been demonstrated primarily using nasal allergen challenge models. The extension of these challenge findings to the in vivo setting has been limited. OBJECTIVE: To obtain nasal lavage fluid from volunteers with perennial and seasonal (in- and out-of-season) allergic rhinitis (AR) and non-atopic non-rhinitic controls for the measurement of eotaxin-1 concentrations and to relate these findings to the symptomatic disease severity, the percentage of lavage eosinophils, and to alpha(2)-macroglobulin (alpha(2)-MG) lavage concentrations, as a marker of vascular permeability and an index of airway inflammation. METHODS: Thirty-seven volunteers with AR (16 seasonal and 21 perennial) and 20 non-atopic non-rhinitic volunteers were recruited and phenotyped. Nasal lavage fluid was obtained by standardized protocol. The nasal lavage fluid concentrations of eotaxin and alpha(2)-MG were measured by ELISA, and differential cell counts performed on cytospins. RESULTS: Eotaxin-1 nasal lavage fluid concentrations were significantly higher in both the perennial and seasonal (in-season) AR groups compared with the controls, and significantly related to the severity of symptom expression and to the percentage of lavage eosinophils. The lavage eosinophil counts were significantly higher in both the symptomatic rhinitis groups compared with the control groups and correlated with the lavage concentrations of alpha(2)-MG. alpha(2)-MG levels were significantly increased in seasonal (in-season) rhinitics compared with both non-atopic controls and seasonal (out-of-season) rhinitics. A significant correlation was observed between the levels of alpha(2)-MG and levels of eotaxin in the symptomatic allergic rhinitic groups. CONCLUSIONS: This study clearly demonstrates the relevance of eotaxin-1 to the pathogenesis of naturally occurring AR.     

Airway epithelial cells produce neurotrophins and promote the survival of eosinophils during allergic airway inflammation

BACKGROUND: Eosinophil-epithelial cell interactions make a major contribution to asthmatic airway inflammation. Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and other members of the neurotrophin family, originally defined as a class of neuronal growth factors, are now recognized to support the survival and activation of immune cells. Neurotrophin levels are increased in bronchoalveolar lavage fluid during allergic asthma. OBJECTIVE: We sought to investigate the role of neurotrophins as inflammatory mediators in eosinophil-epithelial cell interactions during the allergic immune response. METHODS: Neurotrophin expression in the lung was investigated by means of immunohistochemistry and ELISA in a mouse model of chronic experimental asthma. Coculture experiments were performed with airway epithelial cells and bronchoalveolar lavage fluid eosinophils. RESULTS: Neurotrophin levels increased continuously during chronic allergic airway inflammation, and airway epithelial cells were the major source of NGF and BDNF within the inflamed lung. Epithelial neurotrophin production was upregulated by IL-1beta, TNF-alpha, and T(H)2 cytokines. Lung eosinophils expressed the BDNF and NGF receptors tropomyosin-related kinase (Trk) A and TrkB, and coculture with airway epithelial cells resulted in enhanced epithelial neurotrophin production, as well as in prolonged survival of eosinophils. Eosinophil survival was completely abolished in the presence of the neurotrophin receptor Trk antagonist K252a. CONCLUSION: During allergic inflammation, airway epithelial cells express increased amounts of NGF and BDNF that promote the survival of tissue eosinophils. Controlling epithelial neurotrophin production might be an important therapeutic target to prevent allergic airway eosinophilia. CLINICAL IMPLICATIONS: Attenuating the release of inflammatory mediators from the activated airway epithelium will become an important strategy to disrupt the pathogenesis of chronic allergic asthma.     

Comparison of allergen-induced late inflammatory reactions in the nose and in the skin in house dust mite-allergic patients with or without asthma

BACKGROUND: It remains to be established which factors contribute to the occurrence of asthma in allergic individuals. We hypothesized that differences in the late allergic inflammatory reaction to allergen between asthmatic and non-asthmatic house dust mite-allergic individuals might contribute to the difference in the clinical presentation of allergy. AIM: To compare allergen-induced changes in parameters for cellular inflammation during the phase of the late allergic reaction in the skin and nose, in house dust mite-allergic individuals with or without asthma. MATERIAL AND METHODS: Nasal and dermal allergen challenges with house dust mite (Dermatophagoides pteronyssinus) extract were performed in 52 house dust mite-allergic individuals, of whom 26 had mild to moderate persistent asthma and 26 had perennial rhinitis without current or past asthmatic symptoms. Serial nasal lavage samples were analyzed for the presence of inflammatory cells (eosinophils and neutrophils) and soluble markers associated with cellular inflammation [interleukin-5 (IL-5), interleukin-8 (IL-8), eosinophil cationic protein (ECP) and myeloperoxidase (MPO)]. Macroscopic late phase skin reactions were studied after intracutaneous skin tests with house dust mite extract. RESULTS: Fixed dose nasal allergen provocation elicited a similar degree of immediate allergic reaction as judged by plasma protein exudation and histamine concentrations in asthma and non-asthmatic rhinitis. Subsequently, no differences between groups were found during the phase of the late allergic reaction (4-24 h) in inflammatory cell influx, plasma protein leakage, ECP or MPO. Likewise, there were no differences in levels of chemotactic cytokines IL-5 and IL-8. In agreement with the results of nasal challenge, the late skin reaction after dermal challenge with a fixed allergen dose and after an allergen dose 10,000 times above the skin threshold for an early skin reaction did not differ between the groups. CONCLUSION: House dust mite-allergic patients with or without asthma have very similar late allergic inflammatory reactions in the skin and in the nose after allergen challenge. Hence, it is unlikely that the occurrence of pulmonary symptoms in asthma is explained by a general tendency of asthmatics to have an enhanced late allergic cellular inflammatory response. Nasal and dermal allergen provocations are adequate models to study allergen-induced inflammation but probably lack the pivotal link which is essential for the development of asthma.     

Nasal eosinophils display the best correlation with symptoms, pulmonary function and inflammation in allergic rhinitis

BACKGROUND: The pathogenesis of allergic rhinitis and its link with asthma are well known. Nevertheless, a complete cross-sectional evaluation of the usually available clinical, functional and immunological parameters has never been made. We assessed nasal symptoms and flow, cytology, cytokines, pulmonary function and methacholine positivity in a large number of patients with pure pollinosis. METHODS: Young men presenting at a military hospital for routine follow-up were recruited for the study. They had to suffer from rhinitis alone (without asthma) for at least 2 years and had to have a positive skin prick test to pollens only. During the pollen season, they underwent symptom evaluation, measurement of nasal flow, nasal scraping and lavage (cell count and assay for IL-4, IL-5, IL-8 and IFNgamma), pulmonary function tests and methacholine challenge. RESULTS: Fifty subjects (23.7+/-4.9 years old) were enrolled. All patients had high clinical scores (9.5+/-1.6) and inflammatory cells (eosinophils: 10.5+/-4 and neutrophils 21.3+/-6) and low nasal flow (482+/-111 ml/s). We found that the number of eosinophils in nasal scrapings highly correlated with all the above-mentioned parameters, including nasal flow, cytokines and spirometric values. A significant positive correlation was found between all inflammatory cells and all cytokines. IL-8, IL-4 and neutrophils displayed only a partial correlation with pulmonary parameters (FEV1, FVC and FEF25-75%), at variance wit IL-5 and eosinophils. Methacholine test positivity significantly correlated with the number of eosinophils in the nasal smear. CONCLUSION: Eosinophils in the nasal smear display the best correlation with all the clinical and immunological parameters in allergic rhinitis and also correlate well with methacholine response.     

Effects of prednisone on the cellular responses and release of cytokines and mediators after segmental allergen challenge of asthmatic subjects.

BACKGROUND: Systemic glucocorticoids are a major therapy for the management of allergic inflammation and asthma; however, information about their effects in vivo are limited. OBJECTIVE: This study was performed to examine the effects of prednisone on inflammatory mediators, cytokines, and cellular responses in the model of segmental allergen challenge (SAC) of allergic asthmatic subjects. METHODS: The effects of a 3-day pretreatment with oral prednisone (30 mg twice daily) on the physiologic and inflammatory responses to SAC were studied in 10 allergic asthmatic subjects in a double-blind, placebo-controlled, crossover protocol. RESULTS: Prednisone improved baseline FEV(1) by 10% and modestly inhibited the SAC-induced fall in FEV(1) at 30 minutes and at 6 to 8 hours. Five minutes after challenge, levels of histamine, PGD(2), 9alpha,11beta-PGF(2), and thromboxane B(2) increased in bronchoalveolar lavage fluid (median increase, 5- to 14-fold); prednisone did not inhibit these responses. Prednisone inhibited (median decrease, 66%-97%) the total influx of inflammatory cells, specifically eosinophils, basophils, and some subsets of T lymphocytes (CD4, CD45RA, and CD45RO cells) assessed 19 hours after SAC, but it did not inhibit the influx of neutrophils. Increases in soluble E-selectin, kinins, and albumin were also inhibited by the glucocorticoid (median decrease, 36%-74%). Prednisone treatment inhibited the appearance of mRNA, protein, or both for T(H)2 cytokines (IL-4 and IL-5), as well as for IL-2 and transforming growth factor alpha, but did not inhibit increases of immunoreactive GM-CSF in bronchoalveolar lavage fluid. CONCLUSION: These studies indicate that prednisone suppresses multiple components of allergic airway inflammation, including cell recruitment, adhesion molecule expression or release, airway permeability, and production of cytokines potentially involved in airway immunity or remodeling.     

Mucosal and systemic inflammatory changes in allergic rhinitis and asthma: a comparison between upper and lower airways

BACKGROUND: Local airway inflammation and airway remodelling are considered important in the clinical expression of allergic asthma. OBJECTIVE: The aim of this study was to compare airway inflammation and remodelling in nasal and bronchial mucosa of subjects with allergic rhinitis with or without asthma. METHODS: Four experimental groups were formed: allergic asthma and rhinitis (n = 19); allergic rhinitis, no asthma (n = 18); atopic subjects, no asthma, no rhinitis (n = 8) and non-allergic healthy control subjects (n = 16). Blood samples, nasal and bronchial biopsy specimens were collected during stable disease. Immunohistochemistry was performed for eosinophils (MBP), mast cells (CD117) and vascular endothelium (CD31). Epithelial loss, reticular basement membrane (RBM) thickness and subepithelial vascularity was assessed with a computer-assisted image analysis system. RESULTS: In nasal and bronchial mucosa, numbers of eosinophils were significantly higher in rhinitis patients with and without asthma than in asymptomatic atopics (P < 0.05) and controls (P < or = 0.01). In bronchial mucosa, the RBM was significantly thickened in rhinitis patients with and without asthma compared to asymptomatic atopics (P < 0.05) and controls (P < 0.01), while in nasal mucosa no differences were seen. Patients with asthma and rhinitis had increased numbers of blood eosinophils (P = 0.05) and skin test reactivity (P = 0.01) compared to patients with rhinitis only. No significant differences could be found between the investigated groups with respect to serum IL-5 and eotaxin levels, the number of mucosal mast cells and the degree of epithelial loss and subepithelial vascularity. Epithelial desquamation was significantly increased in the bronchial mucosa compared to nasal mucosa, not only in asthmatics (P < 0.001), but also in atopics without asthma and rhinitis (P = 0.02). CONCLUSIONS: This study shows that allergic inflammation, increased basement membrane thickness and epithelial desquamation are present in the lower airways of atopic subjects, even before the onset of clinical symptoms. Despite the presence of inflammatory cells, no structural changes could be assessed in nasal mucosa of allergic patients.     

Noninvasive methods for the detection of upper and lower airway inflammation in atopic children

BACKGROUND: Exhaled nitric oxide (FE(NO)) and exhaled breath condensate (EBC) are noninvasive methods to assess inflammation. OBJECTIVE: To investigate the role of the FE(NO) and of the EBC pH and IL-5 levels in atopic children. METHODS: We evaluated oral and nasal FE(NO) and the pH and IL-5 of oral and nasal EBC in children with atopic dermatitis (AD; n = 18), allergic rhinitis (AR; n = 18), intermittent asthma (n = 21), moderate persistent asthma (n = 18), and healthy controls (HCs; n = 16). RESULTS: Oral FE(NO) was significantly increased in asthma, whereas the nasal values were increased in AR and asthma in comparison with HCs. The pH of oral EBC was lower in AD and asthma than in AR and HCs, whereas the nasal levels were lower in AD, AR, and asthma than in HCs. The oral IL-5 was higher in AD, AR, and asthma in comparison with HCs, whereas the nasal IL-5 concentrations were higher in asthma and AR than in HCs. In AR, the nasal FE(NO) correlated with the IL-5 values and with the disease duration. In intermittent asthma, oral and nasal pH inversely correlated with the exacerbations, whereas in moderate asthma, the nasal IL-5 positively correlated with exacerbations. In AD, the oral and nasal IL-5 positively correlated with the serum IgE. CONCLUSION: These markers of nasal and bronchial inflammation, accessible with noninvasive techniques, might be useful to identify patients with uncontrolled diseases and to verify the usefulness of new therapeutic approaches. CLINICAL IMPLICATIONS: These markers are useful tools to monitor the upper and lower airway inflammation in atopic children.     

Involvement of eosinophils in the early-phase allergic reaction in a guinea pig rhinitis model

BACKGROUND: Eosinophils are found in the nasal lavage fluid (NLF) and nasal biopsies of patients with allergic rhinitis after a nasal antigen challenge, and associated not only with a late-phase allergic reaction (LPR) but also an early phase allergic reaction (EPR). Numerous studies have been carried out to clarify the participation of eosinophils in LPR or airway hyperresponsiveness. However, there has been no published report describing in detail the role of eosinophils during EPR. To better understand the involvement of eosinophils in EPR, we studied the effects of repeated antigen challenges on nasal airway responsiveness and eosinophilic inflammation in EPR using a guinea pig rhinitis model. METHODS: Nasal airway responsiveness was measured as the nasal airway resistance (NAR) after nasal antigen provocation. Eosinophilic inflammation during EPR was assessed by nasal lavage and histopathological examination using two groups of animals: those in group 1 were subjected to a sensitization pretreatment only, and those in group 2 were subjected to a pretreatment of sensitization followed by repeated nasal challenges. RESULTS: Repeated antigen challenges induced nasal hyperresponsiveness as indicated by a decrease in the antigen provocation dose and a significant increase in NAR. Furthermore, significant increases in eosinophil counts, eosinophil peroxidase (EPO) activity and protein content in NLF during EPR were observed following antigen provocation in group 2. There were significant correlations between the levels of these parameters, and albumin was the most prevalent of the proteins in NLF. Histopathological examination showed that the degree of eosinophil infiltration into the lamina propria of the nasal mucosa of the animals in group 2 was significantly and apparently higher than in group 1. Particularly, epithelial disruption and mucosal edema were significantly elevated after antigen provocation in group 2. CONCLUSIONS: These results suggest that chronic eosinophil accumulation is induced by repeated antigen challenges in the nasal tissue, and that once antigen provocation occurs, eosinophils in the tissue are activated and responsible for the amplification of EPR such as vascular permeability and mucosal edema.