Eotaxin-2 and eotaxin-3 expression is associated with persistent eosinophilic bronchial inflammation in patients with asthma after allergen challenge

BACKGROUND: Eotaxin-1, eotaxin-2, and eotaxin-3 are chemokines involved in the activation and recruitment of eosinophils through activation of their main receptor, CC chemokine receptor 3. The differential roles of these chemokines still remain to be established. It has been suggested that eotaxin-1 is an important mediator in the early phase of allergen-induced recruitment of eosinophils into the airways. Eotaxin-2 and eotaxin-3 might play a role in the subsequent persistence of allergen-induced bronchial eosinophilia. OBJECTIVE: The aim of this study was to determine the expression of eotaxins and eosinophil counts in the bronchial mucosa of subjects with mild asthma after resolution of the late-phase asthmatic response (LAR). METHODS: The expression of eotaxins and eosinophil counts were determined in bronchial biopsy specimens obtained from 10 subjects with mild asthma 48 hours after diluent and allergen challenge by using immunohistochemistry. Positively stained cells were counted in a 125-mum-deep zone of the lamina propria. RESULTS: Eotaxin-2 and eotaxin-3 expression in bronchial mucosa was significantly increased 48 hours after allergen challenge ( P = .001 and P = .013, respectively). At this time point, when marked tissue eosinophilia was still present, these increases were positively correlated with the magnitude of the LAR ( r = 0.72, P = .019 and r = 0.64, P = .046, respectively). Furthermore, eotaxin-2 expression was associated with the number of eosinophils after allergen challenge ( r = 0.72, P = .018). CONCLUSION: Our findings suggest that eotaxin-2 and eotaxin-3 might account for the persistence of bronchial eosinophilia after resolution of the LAR.     

Cromolyn sodium suppresses eosinophilic inflammation in patients with aspirin-intolerant asthma.

BACKGROUND: Although administration of cromolyn sodium is one of the most useful drugs for the treatment of aspirin-intolerant asthma (AIA), both its pharmacologic mechanism of action and association with the pathogenesis remain obscure. OBJECTIVE: This study was designed to investigate the protective effect of cromolyn sodium on airway responsiveness to the sulpyrine provocation test, and to examine whether its activity is associated with a reduction in eosinophilic inflammation. METHODS: Patients were randomly assigned to receive cromolyn sodium (20 mg/2 mL, or 1 ampoule; Fujisawa, Osaka, Japan) or matching placebo (2 mL of saline) four times daily for 1 week. We evaluated the effects of pretreatment with cromolyn sodium on bronchoconstriction precipitated by inhalation of sulpyrine in 16 adult patients with mild or moderate AIA; those who were in stable clinical condition were allocated to this study. A double-blind, randomized, crossover design was used. Blood and sputum samples were taken in the morning on the sulpyrine provocation testing day. Eosinophil counting and measurement of eosinophilic cationic protein (ECP) were performed. RESULTS: Inhaled cromolyn sodium protect against aspirin-induced attacks of asthma through mechanisms not related to the bronchodilator property, but related to the improvement of the bronchial hypersensitivity, almost completely in all patients (P < 0.001). After 1 week's treatment with cromolyn sodium, patients' symptoms, blood and sputum eosinophils counts, and sputum ECP levels were significantly decreased compared with both placebo and baseline. CONCLUSIONS: Cromolyn sodium has a bronchial anti-inflammatory effect associated with decreased eosinophilic infiltration. This is the first report that cromolyn sodium reduces blood and sputum eosinophils counts and sputum ECP levels in AIA.     

Exhaled nitric oxide identifies the persistent eosinophilic phenotype in severe refractory asthma

BACKGROUND: The fractional concentration of exhaled nitric oxide (FENO) is increased in asthma, correlates with eosinophilic inflammation, and decreases after steroid therapy. OBJECTIVE: We sought to examine whether persistent eosinophilia would be accompanied by an increased FENO level despite steroid therapy in patients with severe refractory asthma (SRA) as manifestations of steroid resistance. METHODS: Subjects with SRA, subjects with mild-moderate asthma, and healthy control subjects had FENO measured, followed by endobronchial biopsy and bronchoalveolar lavage. Tissue and bronchoalveolar lavage inflammatory cells were assessed for all subjects, and eosinophil status (EOS+/EOS-) was determined for subjects with SRA. RESULTS: Twenty-four subjects with SRA, 15 subjects with moderate-mild asthma, and 17 healthy control subjects were studied. Subjects with EOS+ SRA had significantly higher median FENO levels compared with levels in subjects with EOS- SRA (P = .0084) and all other groups. In subjects with SRA, FENO levels correlated with tissue eosinophils (r(s) = 0.54, P = .007), lymphocytes (r(s) = 0.40, P = .003), and mast cells (r(s) = 0.44, P = .05). FENO levels of greater than 72.9 ppb were associated with a sensitivity of 0.56 and a specificity of 1.0 for EOS+ status in subjects with SRA. CONCLUSION: FENO measurement identified the subgroup of subjects with SRA with persistent eosinophilia despite steroid therapy. Further studies are needed on the use of FENO to monitor response to therapy over time in subjects with SRA.     

Clarithromycin suppresses bronchial hyperresponsiveness associated with eosinophilic inflammation in patients with asthma.

BACKGROUND: Although long-term administration of 14-membered macrolide antibiotics is a therapeutic alternative in asthma, both its pharmacologic mechanism of action and association with the pathogenesis of asthma remain obscure. OBJECTIVE: This study investigated the suppressive effect of clarithromycin on airway responsiveness to methacholine provocation testing and examined whether chrarithromycin's antiasthmatic activity is associated with a reduction in eosinophilic inflammation. METHODS: For 8 weeks, patients received 200 mg of clarithromycin or identical-appearing placebo twice daily. We assessed the effects of treatment with clarithromycin on bronchoconstriction precipitated by inhalation of methacholine in 17 adults with mild or moderate bronchial asthma who were in stable clinical condition. A double-blind, randomized, crossover design was used. Eosinophil counts and eosinophilic cationic protein (ECP) levels were determined in blood and sputum samples obtained on the morning of the methacholine provocation testing day. RESULTS: After 8 weeks of treatment with clarithromycin, patients' symptoms, blood and sputum eosinophils counts and sputum ECP levels were significantly decreased compared with both placebo and baseline. Furthermore, values of PC20 methacholine improved in all patients after clarithromycin treatment. CONCLUSIONS: Clarithromycin has a bronchial anti-inflammatory effect associated with decreased eosinophilic infiltration. This study suggests interesting therapeutic possibilities for bronchial asthma that warrant further trials.     

Airway inflammation and eotaxin in exhaled breath condensate of patients with severe persistent allergic asthma during omalizumab therapy

PurposeThe central role of IgE in allergic inflammation in asthma has provided a rationale for the development of omalizumab, the humanized monoclonal anti-IgE antibody. The aim of the study was to determine the effect of omalizumab treatment on changes in airway inflammatory process and eotaxin in exhaled breath condensate in patients with persistent severe allergic asthma.Material and MethodsThe study was performed on a group of 19 patients with severe persistent allergic asthma treated with conventional therapy (according to GINA 2006) and with or without omalizumab (9 vs 10 patients). Eotaxin in exhaled breath condensate, exhaled nitric oxide, blood eosinophil count and serum ECP were measured before and after 16 weeks of therapy.ResultsIn the group treated with omalizumab, a statistically significant decrease in the concentrations of eotaxin in EBC, FENO, serum ECP, and blood eosinophil count after 16 weeks of treatment was observed. Statistically significant correlations were revealed between the decrease in eotaxin and the decrease in FENO, serum ECP and blood eosinophil count after omalizumab therapy.ConclusionsDownregulation of eotaxin expression in the airways through limitation of eosinophilic inflammation could be essential in the beneficial effect of anti-IgE therapy with omalizumab in asthma patients.     

Cost-effectiveness of omalizumab in patients with severe persistent allergic asthma

BACKGROUND: The health, economic and societal burden of asthma is considerable, and is greatest in patients with severe asthma, particularly when inadequately controlled. Real-life studies that assess the effectiveness of treatment are of particular interest. METHODS: We determined the incremental cost-effectiveness ratio (ICER) of adding omalizumab to standard therapy using data from the real-life 1-year randomized open-label study (ETOPA) and using Canada as a reference country. Only patients receiving high-dose ICS plus LABA were included in the analysis, reflecting the EU label for omalizumab. Costs and quality-adjusted life years (QALYs) gained were used to calculate the ICER for omalizumab (cost/QALY). Probabilistic sensitivity analysis was performed to determine the 95% confidence interval and one-sided sensitivity analyses were performed. RESULTS: The base case lifetime analysis of standard therapy vs standard therapy plus add-on omalizumab for the first 5 years, gave an ICER of 31,209 Euro. Probabilistic sensitivity analysis indicated that the 95% confidence interval around the ICER was 27,739-40,840 Euro. The ICER range for one-way sensitivity analyses was 23,762 Euro without discounting to 66,443 Euro without inclusion of asthma-related mortality. CONCLUSIONS: This study demonstrates that add-on omalizumab therapy is cost-effective in patients with severe persistent allergic asthma.     

Distinguishing severe asthma phenotypes: role of age at onset and eosinophilic inflammation

BACKGROUND: Asthma is a heterogeneous process, yet little is understood regarding phenotypes. OBJECTIVE: To determine whether phenotypic differences exist between early-onset, severe asthma as compared with late-onset disease and whether the presence or absence of eosinophilia influences the phenotypes. METHODS: Cross-sectional analysis of integrated clinical, physiologic, and pathologic data collected from 80 subjects with severe asthma. Subjects were divided into those with asthma onset before age 12 years (n = 50) versus after age 12 (n = 30) and by the presence or absence of lung eosinophils. RESULTS: Subjects with early-onset, severe asthma had significantly more allergen sensitivity (skin test positivity, 98% vs 76%, P <.007) and more allergic symptoms (P values all 相似文献   

Effects of suplatast tosilate on allergic eosinophilic airway inflammation in patients with mild asthma

BACKGROUND: Bronchial asthma is a chronic inflammatory disease characterized mainly by infiltration of the airway mucosa by various inflammatory cells, notably eosinophils. T(H)2-type cytokines are suggested to be deeply involved in the pathogenesis of asthma. OBJECTIVE: We sought to determine the suppressive effects of suplatast tosilate, an inhibitor of T(H)2-type cytokines, on eosinophilic inflammation of the bronchial mucosa in patients with mild asthma. METHODS: Airway hyperresponsiveness tests, pulmonary function tests, eosinophil measurements in induced sputum, and bronchial mucosa biopsies were performed before and after treatment with suplatast tosilate for 6 weeks in 15 patients with mild asthma and in 13 control patients with mild asthma not receiving suplatast tosilate. This study was performed as a case-controlled open study. RESULTS: In the treatment group a significant improvement in the provocation concentration of histamine was observed (P <.05). Improvements in peak expiratory flow (P <.01) and in symptom score (P <.05) were also noted in the suplatast tosilate-treated group. Moreover, the average number of infiltrating eosinophils and EG2(+) cells significantly decreased (both P <.05), as did the ratios of eosinophils and EG2(+) cells in sputum (both P <.01). The average number of CD4(+) and CD25(+) T lymphocytes also decreased (both P <.05). CONCLUSION: Suplatast tosilate appears to inhibit allergic airway inflammation mediated by T(H)2-type cytokine and to improve clinical symptoms in patients with mild asthma.     

Airway inflammation assessed by invasive and noninvasive means in severe asthma: eosinophilic and noneosinophilic phenotypes

BACKGROUND: Airway inflammation assessed by bronchial biopsies demonstrates distinct eosinophilic and noneosinophilic phenotypes in severe asthma, but their relationship to other biomarkers of disease (induced sputum and nitric oxide [NO]) is not clear. OBJECTIVES: We sought to compare airway inflammation using noninvasive (induced sputum, exhaled NO), and invasive (bronchial biopsies) methods in moderate and severe asthma and to assess whether induced sputum and exhaled NO would allow the identification of eosinophilic and noneosinophilic phenotypes in severe asthma. METHODS: We performed a cross-sectional study of 32 subjects with severe asthma and 35 subjects with moderate asthma, from whom we obtained bronchial biopsies, induced sputum, and exhaled NO measurements. RESULTS: Among subjects with severe asthma, we identified eosinophilic and noneosinophilic phenotypes using both bronchial biopsies and sputum cell counts. However, the vast majority of subjects with high sputum eosinophil counts did not have high mucosal eosinophil counts. Exhaled NO was increased in the eosinophilic phenotype as judged from bronchial biopsy findings, but not on the basis of induced sputum. Subjects with high sputum eosinophil counts experienced more asthma exacerbations than the subjects with low sputum eosinophil counts. In contrast, we did not find any differences in the clinical characteristics between eosinophilic and noneosinophilic phenotypes that were identified by bronchial biopsies. CONCLUSION: The use of sputum cell counts allowed the identification of a subgroup of subjects with severe asthma who were at risk of more frequent asthma exacerbations. CLINICAL IMPLICATIONS: Monitoring sputum eosinophil counts in subjects with severe asthma may allow identifying the subjects with the greatest disease activity.