Vascular endothelial growth factor up-regulation and bronchial wall remodelling in asthma

BACKGROUND: There is increasing in vitro evidence to support a role for vascular endothelial growth factor (VEGF), a major regulator of angiogenesis, as a mediator of fibrosis associated with neovascularization. OBJECTIVE: We tested the hypothesis that VEGF is involved both in increased airway mucosal vascularity and in the subepithelial fibrosis of asthmatic patients. METHODS: Bronchial biopsies were performed in 24 asthmatic patients and eight healthy controls. Immunostaining, using computerized image analysis, was performed using monoclonal antibodies against VEGF(+) cells, type IV collagen, to outline the basement membrane thickness, and tryptase and EG2, to identify mast cells and eosinophils, respectively. RESULTS: The counts of VEGF(+) cells (P<0.05), mast cells and EG2(+) cells (both P<0.01) were higher in asthmatics than in controls. The number of vessels, the vascular area in the lamina propria, and the basement membrane thickness were significantly higher in asthmatics than in healthy volunteers (P<0.01). Moreover, in asthmatic patients, the number of VEGF(+) cells was significantly related to the number of vessels (P<0.01), to mast cells (P<0.01) and to basement membrane thickness (P<0.01). A colocalization study also revealed that mast cells were a relevant cellular source of VEGF. High doses of inhaled fluticasone propionate significantly reduced VEGF(+) cells (P<0.05), vessel number (P<0.05), vascular area (P<0.05) and basement membrane thickness (P<0.05) in a subgroup of asthmatic patients. CONCLUSIONS: This study shows that VEGF, in addition to being involved in the vascular component of airway remodelling, may play a role in the thickening of the basement membrane in asthma.     

Increased levels of vascular endothelial growth factor in induced sputum in asthmatic patients

BACKGROUND: Vascular endothelial growth factor (VEGF) is highly expressed in the airway of asthmatic patients. As VEGF increases airway vascular permeability, consequent thickening of the airway wall mucosa may lead to narrowing of the airway lumen. OBJECTIVE: We evaluated the relationship between VEGF levels in induced sputum and eosinophilic inflammatory profiles, and the degree of airway vascular permeability in asthmatic patients and we evaluated the effect of inhaled corticosteroids on VEGF levels in induced sputum. METHODS: Induced sputum specimens were obtained from 28 glucocorticosteroids free asthmatics and 11 healthy control subjects. We examined VEGF levels and airway vascular permeability index in induced sputum. After the initial sputum induction, 21 asthmatics received 8-week inhaled beclomethasone dipropionate (BDP, 800 micro g/day) therapy, then sputum induction was repeated. RESULTS: The VEGF levels in asthmatics were significantly higher than in healthy control subjects (P < 0.0001). The VEGF levels were negatively correlated with forced expiratory volume of 1 s (FEV1, % predicted, r = - 0.68, P < 0.001), the percentage of eosinophils (r = 0.51, P < 0.01) and ECP levels (r = 0.39, P < 0.05). Moreover, the VEGF levels were significantly correlated with airway vascular permeability index (r = 0.61, P < 0.001). After 8-week inhaled BDP therapy, the VEGF levels were significantly decreased compared to pretreatment levels (P < 0.0001) and the VEGF levels were significantly correlated with airway vascular permeability index even in post-treatment asthmatics (r = 0.62, P < 0.01). CONCLUSION: The VEGF levels in induced sputum were increased in asthmatics and its levels were associated with degree of airway narrowing and airway vascular permeability. These findings provide strong evidence that VEGF may play an important role in the pathogenesis of bronchial asthma.     

Expression of vascular endothelial growth factor, basic fibroblast growth factor, and angiogenin immunoreactivity in asthmatic airways and its relationship to angiogenesis

BACKGROUND: Angiogenesis is a prerequisite for airway remodeling in bronchial asthma. Several growth factors may play important roles in inflammation and angiogenesis through effects on inflammatory cell infiltration or neovascularization. OBJECTIVE: We sought to compare bronchial vascularity and expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and angiogenin in bronchial biopsy specimens from asthmatic and healthy control subjects. METHODS: Bronchial biopsy specimens were obtained from 16 asthmatic subjects and 9 normal control subjects. The number of vessel profiles and the vascular area per unit area on a histologic section were estimated by using computerized image analysis after staining for type IV collagen in vessel walls. Numbers of VEGF+, bFGF+, and angiogenin+ cells were determined by means of immunoreactivity. RESULTS: The airways of asthmatic subjects had significantly more vessels (P < .05) and greater vascular area (P < .001) than that observed in control subjects. Asthmatic subjects exhibited higher VEGF and bFGF and angiogenin immunoreactivity in the submucosa than did control subjects (P < .001, respectively). Significant correlations were detected between the vascular area and the numbers of angiogenic factor-positive cells (VEGF: rs = 0.93, P < .001; bFGF: rs = 0.83, P < .001; angiogenin: rs = 0.88, P < .001) within the asthmatic airways. Furthermore, the degree of vascularity was inversely correlated with airway caliber and airway responsiveness. Colocalization analysis revealed that the angiogenic factor-positive cells were CD34+ cells, eosinophils, and macrophages. CONCLUSION: Our results suggest that increased vascularity of the bronchial mucosa in asthmatic subjects is closely related to the expression of angiogenic factors, which may then contribute to the pathogenesis of asthma.     

The involvement of matrix metalloproteinase-9 in airway inflammation of patients with acute asthma

BACKGROUND: Bronchial asthma is an inflammatory disease of the airway characterized by airway remodelling, and is due at least in part to an excess of extracellular matrix (ECM) deposition in the airway wall, which leads to subepithelial collagen deposition. Matrix metalloproteinase-9 (MMP-9) is the major proteolytic enzyme that induces bronchial remodelling in asthma. MMP-9 is also important in the migration of inflammatory cells through basement membrane components. OBJECTIVES: We evaluated whether airway inflammatory cells correlated with levels of MMP-9 in acute asthma and we examined the time course of sputum levels of MMP-9 activity in patients with spontaneous asthma exacerbation. METHODS: We performed zymographic analysis and checked levels of MMP-9 by means of enzyme immunoassay. MMP-9 levels were also evaluated during a spontaneous attack of asthma. RESULTS: Pro-MMP-9 activities and concentrations of MMP-9 in asthmatic patients significantly exceeded those of control subjects (P < 0.01). The activities of pro-MMP-9 were significantly higher in acute asthmatic patients than in stable asthmatic patients (P < 0.01). The elevated MMP-9 activities significantly decreased after 7 and 28 days of therapy. In acute asthmatic patients, the levels of sputum MMP-9 significantly correlated with the total macrophage + neutrophil + eosinophil cell numbers. CONCLUSION: These data suggest that airway inflammation after asthma exacerbation correlates with the overproduction of MMP-9, which then leads to airway remodelling.     

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.     

Imbalance between vascular endothelial growth factor and endostatin levels in induced sputum from asthmatic subjects

BACKGROUND: Angiogenesis has recently attracted considerable attention as a component of airway remodeling in bronchial asthma. Vascular endothelial growth factor (VEGF) is highly expressed in asthmatic airways, and its contribution to airway remodeling has been reported. Although angiogenesis is regulated by a balance of angiogenic and antiangiogenic factors, the relative levels of antiangiogenic factors in asthmatic airways have not been evaluated. OBJECTIVE: We sought to determine whether an imbalance between angiogenic and antiangiogenic factors exists in asthmatic airways. METHODS: We simultaneously measured VEGF and endostatin levels and evaluated their correlation and balance in induced sputum from 18 steroid-naive asthmatic subjects and 11 healthy control subjects. After initial sputum induction, asthmatic subjects underwent 8 weeks of inhaled beclomethasone dipropionate (BDP; 800 microg/d) therapy, and sputum induction was then repeated. RESULTS: VEGF and endostatin levels in induced sputum were significantly higher in asthmatic subjects than in control subjects (P <.001). There was a significant correlation between VEGF and endostatin levels in both control subjects (r = 0.995, P <.001) and asthmatic subjects (r = 0.923, P <.001). Moreover, the VEGF/endostatin level ratio in asthmatic subjects was significantly higher than that in control subjects (P <.0001). After 8 weeks of inhaled BDP therapy, the VEGF level in induced sputum in asthmatic subjects was significantly decreased (P <.001), whereas the endostatin level was not. A correlation between VEGF and endostatin levels existed even after BDP therapy (r = 0.861, P <.001). Moreover, the VEGF/endostatin level ratio was significantly decreased to the same level as in the control subjects after BDP therapy (P <.0001). CONCLUSION: There was an imbalance between VEGF and endostatin levels in induced sputum from asthmatic subjects. This imbalance might play an important role in the pathogenesis of bronchial asthma through its effects on angiogenesis.     

Inter-relationships between airway inflammation, reticular basement membrane thickening and bronchial hyper-reactivity to methacholine in asthma; a systematic bronchoalveolar lavage and airway biopsy analysis

Background Asthma is accepted as a disease characterized by airway inflammation, with evidence that airway structural changes, or ‘remodelling’ occurs. There are few studies relating airway physiology, inflammation and remodelling, however. We have carried out a study of inter‐relationships between airway inflammation, airway remodelling, reticular basement membrane (RBM) thickening, and bronchial hyper‐reactivity (BHR), before and after high‐dose inhaled corticosteroid (fluticasone propionate 750 μg b.d.), in a group of relatively mild but symptomatic, steroid naïve asthma patients. Methods Double‐blind, randomized, placebo‐controlled, parallel group study of inhaled corticosteroid (ICS) in 35 asthmatics, with bronchoalveolar lavage (BAL) and airway endobronchial biopsy (EBB) for inflammatory cell profiles and EBB for airway remodelling carried out at baseline, 3 and 12 months. Results At baseline RBM thickening was related to BAL mast cells and EBB eosinophil counts. In turn baseline log EBB EG2 eosinophil count, log%BAL epithelial cells and log RBM thickness explained 55% of the variability in BHR. Conclusion We provide new information that airway inflammation, remodelling, and BHR in asthma are inter‐related and improved by ICS therapy. Our data potentially support the need for early and long‐term intervention with ICS even in relatively mild asthmatics, and the need to further assess the potential merit of longitudinal BHR testing in management of some patients, as this may reflect both airway inflammation and remodelling.     

Serum eosinophil cationic protein levels measured during exacerbation of asthma: characteristics of patients with low titres

BACKGROUND: Serum eosinophil cationic protein (ECP) levels reflect ongoing eosinophilic airway inflammation and are used as a marker for asthma activity. ECP levels, however, may not be elevated in some asthmatic patients, even when they are symptomatic. OBJECTIVE: To clarify the characteristics of patients with 'low' ECP titres despite asthma exacerbation. METHODS: Serum ECP levels were measured in 113 asthmatic patients during exacerbation. Patients were divided into two groups according to ECP titre: a high ECP group (H; ECP > or = 16.0 microg/L) and a low ECP group (L; ECP <16.0 microg/L). Twenty-two patients who had recently received systemic steroids were excluded and the clinical features of the remaining patients in H (n = 54) and L (n = 37 were compared. RESULTS: Gender, atopic or smoking status, disease severity, inhaled steroid or theophylline usage, peak expiratory flow (% personal best) and forced expiratory volume in 1 s (FEV1) (% predicted) did not significantly differ between the two groups. Patients in L were significantly older and had longer disease duration and lower serum IgE levels than those in H. Multivariate analysis combining age, disease duration and IgE levels showed that age and disease duration were independently associated with ECP level. Airway wall thickness, assessed in a subset of patients using computed tomography, was significantly larger in L. CONCLUSION: Serum ECP levels in asthmatic patients may not be elevated during exacerbation and thus may not be a useful marker in patients who are older, have longer disease duration or possibly have thicker airway walls. Mechanisms other than eosinophilic inflammation, such as airway remodelling, may be involved in asthma exacerbation in these patients.     

Relationship among pulmonary function, bronchial reactivity, and exhaled nitric oxide in a large group of asthmatic patients.

BACKGROUND: Bronchial reactivity and exhaled nitric oxide (eNO) are not often used to monitor control and severity of asthma in clinical practice. OBJECTIVE: To evaluate the relationship among different physiologic measures (pulmonary function, nonspecific bronchial reactivity, and eNO) in asthmatic patients. METHODS: Cross-sectional, hospital-based study conducted in patients with varied asthma severity. RESULTS: A total of 392 patients participated in the study. There was no difference in eNO levels between patients taking inhaled corticosteroids (ICS group) and patients not receiving inhaled corticosteroids (NICS group). However, the percentage of predicted forced expiratory volume in 1 second (FEV1) and the provocative dose of methacholine causing a 20% decrease in FEV1 were significantly lower in the ICS group compared with the NICS group (mean, 83.2%; 95% confidence interval [CI], 80.4%-86.0%; vs mean, 94.1%; 95% CI, 91.1%-97.1%; P = .001; and geometric mean, 0.32 mg; 95% CI, 0.23-0.45 mg; vs geometric mean, 0.58 mg; 95% CI, 0.42-0.81 mg; P = .01; respectively). Patients with more severe bronchial hyperresponsiveness had a lower percentage of predicted FEV1 values (P < .001) and levels of eNO were significantly increased with increasing bronchial hyperresponsiveness (P < .001). There was no relationship between the percentage of predicted FEV1 and eNO. Atopic patients had significantly higher eNO levels than nonatopic patients (geometric mean, 11.21 ppb; 95% CI, 10.07-12.49 ppb; vs geometric mean, 7.76 ppb; 95% CI, 6.11-9.85 ppb; P = .006; respectively). CONCLUSIONS: eNO values are not related to the degree of airway obstruction but are related to airway reactivity and atopic status independent of inhaled corticosteroid use. Higher values of eNO are seen with increased airway reactivity.     

Comparison of roflumilast, an oral anti-inflammatory, with beclomethasone dipropionate in the treatment of persistent asthma

BACKGROUND: Roflumilast is an oral, once-daily phosphodiesterase 4 inhibitor with anti-inflammatory activity in development for the treatment of asthma. Roflumilast was compared with inhaled beclomethasone dipropionate (BDP) in patients with asthma. METHODS: In a double blind, double-dummy, randomized, noninferiority study, 499 patients (forced expiratory volume in 1 s [FEV1] = 50-85% predicted) received roflumilast 500 microg once daily or BDP 200 microg twice daily (400 microg/day) for 12 weeks. Lung function and adverse events were monitored. RESULTS: Roflumilast and BDP significantly improved FEV1 by 12% (270 +/- 30 ml) and 14% (320 +/- 30 ml), respectively (P < 0.0001 vs baseline). Roflumilast and BDP also significantly improved forced vital capacity (FVC) (P < 0.0001 vs baseline). There were no significant differences between roflumilast and BDP with regard to improvement in FEV1 and FVC. Roflumilast and BDP showed small improvements in median asthma symptom scores (-0.82 and -1.00, respectively) and reduced rescue medication use (-1.00 and -1.15 median puffs/day, respectively; P < 0.0001 vs baseline). These small differences between roflumilast and BDP were not considered clinically relevant. Both agents were well tolerated. CONCLUSIONS: Once daily, oral roflumilast 500 microg was comparable with inhaled twice-daily BDP (400 microg/day) in improving pulmonary function and asthma symptoms, and reducing rescue medication use in patients with asthma.     

Gene expression of vascular endothelial growth factor and its receptors and angiogenesis in bronchial asthma

BACKGROUND: Angiogenesis is a feature of airway remodeling in bronchial asthma. The mechanism responsible for this angiogenesis is unknown. Vascular endothelial growth factor (VEGF) is a potent inducer of endothelial cells, which may contribute to chronic inflammation and angiogenesis. OBJECTIVE: We sought to investigate the molecular mechanisms underlying increased vascularity, and we examined the mRNA expression of VEGF and its receptors (flt-1 and flk-1) within bronchial biopsy specimens from asthmatic patients and normal control subjects. METHODS: Endobronchial biopsy specimens were examined immunocytochemically by staining with anti-type IV collagen mAb to evaluate vessel density by using computer-assisted image analysis. Specimens were also analyzed for the presence of the mRNAs of VEGF and its receptors with in situ hybridization. RESULTS: The extent of airway vascularity was increased in asthmatic subjects compared with that in control subjects (P <.01). Asthmatic subjects exhibited a greater expression of VEGF, flt-1, and flk-1 mRNA(+) cells in the airway mucosa compared with that in control subjects (P <.001 for each comparison). The degree of vascularity was associated with the number of VEGF, flt-1, and flk-1 mRNA(+) cells. Numbers of cells expressing VEGF mRNA inversely correlated with airway caliber (r = -0.83, P <.01) and airway hyperresponsiveness (r = -0.97, P <.001). Colocalization studies showed that macrophages, eosinophils, and CD34(+) cells were the major sources of VEGF; CD34(+) cells, macrophages, and T cells expressed both flt-1 and flk-1. CONCLUSION: These findings provide evidence that VEGF may play an important role in angiogenesis and subsequent airway remodeling in bronchial asthma.     

Effect of low-dose ciclesonide on allergen-induced responses in subjects with mild allergic asthma

BACKGROUND: Inhalation of allergens by sensitized patients with asthma induces reversible airway obstruction, airway hyperresponsiveness, and eosinophilic airway inflammation. Attenuation of allergen-induced bronchoconstriction and inflammation has been used to examine the efficacy of therapeutic agents such as inhaled corticosteroids in asthma. Ciclesonide, a nonhalogenated inhaled corticosteroid being developed for the treatment of persistent asthma, remains inactive until cleaved by esterases in the lung. OBJECTIVE: This study examined the effect of low doses of inhaled ciclesonide, 40 microg and 80 microg, on allergen-induced bronchoconstriction, serum eosinophil cationic protein, and eosinophilic airway inflammation. METHODS: Twenty-one nonsmokers with mild atopic asthma completed a multicenter, randomized, 3-way crossover study comparing the effects of 7-day treatment of ciclesonide or placebo. Allergen-induced responses, including the early and late fall in FEV1, peripheral blood eosinophils, serum eosinophil cationic protein levels, and eosinophils in induced sputum were measured. RESULTS: Ciclesonide 80 microg attenuated the early and late asthmatic responses, including the change in FEV1, serum eosinophil cationic protein, and sputum eosinophils measured at 24 hours postchallenge (P < .025). Ciclesonide 40 microg attenuated the late asthmatic responses and sputum eosinophils measured at 24 hours postchallenge (P < .025), with no effect on the early allergen-induced bronchoconstriction, 24-hour FEV1, or serum eosinophil cationic protein levels (P < .025). CONCLUSION: With the exception of 24-hour postchallenge peripheral blood eosinophils, a low dose of ciclesonide, 80 microg, was effective in blocking all allergen-induced responses measured.     

Protective effect of inhaled furosemide on allergen-induced early and late asthmatic reactions

The movement of ions and water across the membranes of bronchial cells is part of the control of the bronchial obstructive response to physical stimuli. In a double-blind, randomized, crossover study, we compared the effect of an aerosol of the loop diuretic furosemide with that of a placebo on the early (within 60 minutes) and late (4 to 12 hours) asthmatic responses to a specific inhaled allergen. We studied 11 subjects with mild allergic asthma, who had both early and late asthmatic responses to a specific inhaled allergen in a preliminary challenge. After placebo administration, the maximal changes (mean +/- SE) from base line in the forced expiratory volume in one second (FEV1) and specific airway resistance were, respectively, a decrease of 35 +/- 4 percent and an increase of 288 +/- 56 percent between 0 and 60 minutes after inhalation of the allergen (early response) and a decrease of 35 +/- 5 percent and an increase of 301 +/- 40 percent between 4 and 12 hours (late response). After furosemide administration (4 ml; 10 mg per milliliter), the early response to inhaled allergen was markedly attenuated in all the subjects, and the late response in all but one. The maximal changes in the FEV1 and specific airway resistance were, respectively, a decrease of 11 +/- 2 percent and an increase of 61 +/- 2 percent between 0 and 60 minutes and a decrease of 20 +/- 4 percent and an increase of 178 +/- 25 percent between 4 and 12 hours (P less than 0.05 for all comparisons). No significant differences were seen in the bronchoconstrictor response to inhaled methacholine after furosemide or placebo administration. We conclude that a furosemide-sensitive mechanism in the airways is involved in the pathogenesis of the reactions of patients with allergic asthma. Whether inhaled furosemide might be useful in the treatment of allergic asthma is uncertain and will require further study.     

Enhanced osteopontin expression in a murine model of allergen-induced airway remodelling

BACKGROUND: Airway remodelling is a central pathophysiological feature of chronic asthma. A wide variety of cytokines and growth factors are likely to be involved in the development of airway remodelling. Osteopontin (OPN) is a cytokine with pro-fibrotic properties; however, its role in airway remodelling in asthma has not been explored. OBJECTIVE: To determine the expression and cellular sources of OPN in a murine model of chronic allergen-induced airway remodelling. METHODS: BALB/c mice were sensitized and exposed to ovalbumin (OVA) or saline inhalations for 5 weeks and killed 24 h after the last inhalation. The following parameters of inflammation and remodelling were assessed: differential cell counts in bronchoalveolar lavage (BAL) fluid lung collagen content (colorimetric biochemical assay) and peribronchial smooth muscle content (immunohistochemistry, followed by image analysis). OPN expression in BAL and lung tissue was determined by PCR and ELISA. The cellular source and distribution of OPN were evaluated by immunohistochemistry and immunofluorescence. RESULTS: OPN expression is up-regulated in lung tissue and in BAL fluid of OVA-treated mice and correlates with collagen content and peribronchial smooth muscle area. In addition, OPN significantly increases collagen deposition in vitro in a murine lung cell line. Cells producing OPN include the airway epithelium and cells of the submucosal inflammatory infiltrate (T cells, eosinophils, and macrophages). Positive staining for OPN was also observed in bronchial tissue from human asthmatic subjects. CONCLUSION: OPN expression in the lungs is increased in a murine model of allergen-induced chronic airway remodelling, suggesting a role for this cytokine in airway remodelling in asthma.     

Effect of inhaled indomethacin in asthmatic patients taking high doses of inhaled corticosteroids

Background: Cyclooxygenase products of arachidonic acid may play a part in bronchoconstriction and airway inflammation in asthma. Objective: We sought to determine the effect of inhaled indomethacin on asthma control and asthma exacerbations during reduction of inhaled corticosteroids in patients with moderate-to-severe steroid-dependent asthma. Methods: We conducted a double-blind, randomized, parallel-group, multicenter study in 38 patients with asthma taking high doses (≥1500 μg/d) of beclomethasone dipropionate (BDP). After a run-in period, patients were assigned inhaled indomethacin (50 mg/d) or placebo for 6 weeks, during which the daily doses of BDP were reduced to half at week 2 and then to one third of the baseline dose at week 4. Results: Data were available from 34 patients. After the reduction of BDP doses, FEV₁, peak expiratory flow, asthma symptoms, and exhaled nitric oxide concentrations deteriorated in both treatment groups, but these effects were less pronounced in the indomethacin group compared with the placebo group. During the 6-week treatment period, 89% of the patients receiving placebo had relapse of asthma, whereas only 38% of those receiving inhaled indomethacin did so (P = .003). Conclusion: Inhalation of indomethacin can reduce asthma exacerbations induced by reduction of high-dose inhaled corticosteroid in steroid-dependent asthma. (J Allergy Clin Immunol 2000;105:1134-9.)     

Effect of inhaled corticosteroid on an immunoreactive thymus and activation-regulated chemokine expression in the bronchial biopsies from asthmatics

BACKGROUND: Bronchial asthma is characterized by airway inflammation, notably because of eosinophils and T cells. Thymus and activation-regulated chemokine (TARC) is known to selectively attract Th2 cells, and is increased in response to interleukin (IL)-4 and IL-13, which share a common receptor, IL-4 receptor alpha (IL-4Ralpha). While corticosteroids have proven, very effective in modifying airway inflammation, the effect of corticosteroids on TARC in asthmatics has been little studied. OBJECTIVE: We examined the effects of inhaled budesonide (BUD) on the expression of TARC and the number of inflammatory cells in bronchial biopsy specimens taken from asthma patients. METHODS: Inhaled BUD 800 mug daily, or placebo was administered for 3 months in a double-blind, parallel-group study, and bronchial biopsies were performed before and after treatment. Biopsy specimens were examined by immunocytochemistry. RESULTS: We observed a significant decrease in the epithelial expression of TARC (P < 0.01) in the BUD group compared with the placebo group. This was accompanied by decreases in the number of eosinophils (P < 0.01), CD3(+) T cells (P < 0.05), and CD4(+) T cells (P < 0.01). A significant correlation was found between changes in epithelial TARC and in IL-4Ralpha immunoreactivity (r(s) = 0.66, P < 0.01). CONCLUSIONS: These findings suggest that corticosteroid asthma treatment can reduce infiltration of the airway by inflammatory cells, an effect modulated by down-regulation of bronchial epithelial TARC expression.     

Chymase-positive mast cells play a role in the vascular component of airway remodeling in asthma

BACKGROUND: There is increasing evidence to support a role for total mast cells (MC(TOT)) in the vascular component of airway remodeling in asthma. On the contrary, up to now, no study has addressed the role of chymase-positive mast cells (MC(TC)) in microvasculature changes. OBJECTIVE: We sought to assess the role of MC(TC) in the vascular component of airway remodeling in asthma. METHODS: We recruited 8 patients with mild-to-moderate asthma and 8 healthy volunteers as a control group. Fiberoptic bronchoscopy with endobronchial biopsy was successfully performed in all subjects. Immunostaining was performed for quantification of vessels, vascular endothelial growth factor (VEGF)-positive cells, MC(TOT), and MC(TC). RESULTS: Compared with those from healthy subjects, endobronchial biopsy specimens from asthmatic patients showed increased numbers of MC(TOT) and MC(TC) and VEGF(+) cells (P < .05). In asthmatic patients the number of vessels and the vascular area was also greater than in healthy subjects (P < .05). Additionally, in asthmatic patients the number of MC(TC) was significantly related to the vascular area (r(s) = 0.74, P < .01) and to the number of VEGF(+) cells (r(s) = 0.78, P < .01). Moreover, a colocalization study revealed that MC(TC) were a relevant cellular source of VEGF. Finally, a 6-week treatment with inhaled fluticasone propionate was able to reduce MC(TC) numbers. CONCLUSION: MC(TC) can play a role in the vascular component of airway remodeling in asthma, possibly through induction of VEGF. CLINICAL IMPLICATIONS: Specific targeting of MC(TC) might be a tool for treating vascular remodeling in asthma.     

Reversibility of airway obstruction in asthma and chronic bronchitis (author transl)

Our purpose was to determine whether, in patients with airway obstruction, the change in the forced expiratory volume in one second (FEV1) which occurs after a bronchodilator drug, is helpful in differentiating asthma from chronic bronchitis. Two groups of patients (48 with asthma and 42 with chronic bronchitis) having a comparable level of initial airway obstruction were selected according to clinical criteria. After salbutamol (200 microgram inhaled) the number of subjects showing a change in FEV1 of at least 20 percent of its initial value or 10 percent of its predicted value was significantly greater (p less than 0.01) in the asthmatic than in the bronchitic group. Lesser changes in FEV1 did not significantly separate the two groups. When the changes in FEV1 were expressed as percentages of both initial and predicted values, the number of positive responses increased in the asthmatic group. However, there were still 20 asthmatics with little or no change in FEV1 after salbutamol who could not be distinguished from the patients with chronic bronchitis. From these data we conclude that, in patients with airway obstruction, a large bronchodilator-induced change in FEV1 strongly suggests the diagnosis of asthma but that the presence of "irreversible" airway obstruction does not disprove it.     

Reduced nonspecific bronchial reactivity and decreased airway response to antigen challenge in atopic asthmatic patients treated with the inhaled leukotriene D4 antagonist, L-648,051

We studied the effect of the inhaled leukotriene D4 antagonist, L-648,051, on antigen-induced bronchoconstriction and nonspecific bronchial reactivity. Ten males with mild atopic asthma completed a double-blind, randomized, two-period, placebo-controlled cross-over study. For a 7-day period patients inhaled either placebo or 6 mg of L-648,051 four times daily. Bronchial reactivity to methacholine was measured at base line (day 1) and after 6 days, treatment (day 7). On day 8, after inhaling 6 mg of the antagonist (or placebo), the patients were challenged by inhaled antigen; they received an additional 6 mg of the antagonist (or placebo) 3 h later. Pulmonary function (forced expiratory volume in 1 s, FEV1) was measured serially through an 8-h post-antigen challenge. Nonspecific airway reactivity was again measured on day 9. Compared to placebo, L-648,051 treatment diminished the methacholine reactivity, on both day 7 (NS) and on day 9 (P < 0.05). In addition, the immediate and late bronchial responses to antigen challenge on day 8 were attenuated in the patients when treated with L-648,051. In the immediate phase (0-3 h postchallenge), the airway response was significantly reduced at all recordings between 20 min and 1 h postchallenge. In the late phase (3-8 h postchallenge), the pulmonary response was also reduced. However, the reduction was statistically significant only at the 5-h recording. The results suggest that sulfidopeptide leukotrienes are of importance for nonspecific airway reactivity, and that leukotriene D4 is a significant mediator in the immediate asthmatic reaction.     

Reticular basement membrane thickening in airways of lung transplant recipients is not affected by inhaled corticosteroids

INTRODUCTION: Chronic rejection is a major problem for all lung transplant programmes, which is functionally manifested by fixed airflow limitation, Bronchiolitis Obliterans Syndrome (BOS). The inclusion of a Pre-BOS category, BOS(0 approximately p), in newly revised guidelines, recognizes the potential importance of early changes. We have previously demonstrated reticular basement membrane (Rbm) thickening in clinically stable lung transplant recipients free from BOS. The present study extends this, testing the hypothesis that inhaled corticosteroid (ICS) therapy will lead to a decrease in Rbm thickness in lung transplant recipients. METHODS: A parallel group, bronchoscopic intervention study of clinically stable lung allograft recipients, free from BOS, but with evidence of airway inflammation. Following baseline assessment of Rbm thickening, subjects were randomized to 3 months of either chlorofluorocarbon-driven beclomethasone diproprionate (BDP) 400 microg b.i.d., or a formulation designed to yield at least an equivalent dose, hydrofluoroalkane-driven BDP, 200 microg b.i.d. RESULTS: Three months treatment with a moderate dose of ICS, including a formulation designed for preferential small airway deposition, had no effect on Rbm thickening (13+/-3 vs. 14+/-5 microm post-ICS). CONCLUSION: Our data would suggest that airway remodelling can occur early in lung allografts and is not affected by moderate dose ICS therapy. Longitudinal studies are required to describe the pathophysiological processes involved in BOS, and specifically to elucidate potential relationships between airway remodelling, airflow obstruction and allograft failure.