Montelukast and bronchial inflammation in asthma: a randomised, double-blind placebo-controlled trial.

BACKGROUND: Examination of bronchoalveolar lavage, induced sputum, and peripheral blood indicate that cysteinyl leukotriene receptor blockers decrease inflammatory cells in asthma but these do not examine airway tissue per se. OBJECTIVES: Our objective was to determine the effect of montelukast, a leukotriene receptor antagonist, on airway tissue inflammatory cells by direct bronchoscopic examination of the bronchial mucosa. METHODS: Adult subjects with mild asthma (pre-bronchodilator FEV(1)> or =70% predicted; PC(20) of < or =4 mg/mL) were given 10mg/day oral montelukast (N=38) or placebo (N=37) for 6 weeks. Bronchial mucosal eosinophils and mast cells were identified and counted. RESULTS: Change from baseline in numbers of biopsy EG2+ ("activated") eosinophils was the primary endpoint; numbers of total (chromotrope 2R+) eosinophils and (tryptase+) mast cells were secondary. Unexpectedly, there were many patients with zero EG2+ eosinophils at baseline. There was a within-group decrease in EG2+ cells, from 13.54 cells/mm (at baseline) to 0.79 cells/mm at 6 weeks in the montelukast group (LS mean change; 95% confidence interval=-13.59 [-25.45, -1.74]cells/mm; P<0.05), a change not observed in the placebo group (-1.17 [-13.26, 10.91]cells/mm; NS). The zero-inflated Poisson statistical model demonstrated that montelukast significantly reduced post-treatment EG2+ cells by 80% compared with placebo (95% CI [70.6-86.8%]; P<0.0001). The data for total eosinophils showed similar changes. The reduction in mast cell numbers was 12% (95% CI [7.9, 16.0]; P<0.0001). CONCLUSION: Direct examination of airway tissue confirms that montelukast decreases the number of eosinophils and mast cells in asthma.

Effects of salmeterol on mucosal inflammation in asthma: a placebo-controlled study.

Although the anti-inflammatory effects of inhaled corticosteroids in the treatment of asthma are established, the effects of long-acting beta2-adrenergic receptor agonists on inflammation are the subject of debate. The aim of the present study was to determine the effect of salmeterol on the numbers of inflammatory cells in biopsy samples of distinct immunophenotype and those expressing the genes for interleukin-4 and -5, regulatory cytokines particularly relevant to asthma. Twenty patients (aged 18-55 yrs) with mild stable asthma were randomised in a three-way crossover study to 6 weeks of treatment with: 1) salmeterol (50 microg b.d.; SM50); 2) fluticasone propionate (250 microg b.d.; FP250), or 3) placebo. Compared with placebo, SM50 significantly reduced the numbers of neutrophils in bronchial biopsy samples and the concentrations of myeloperoxidase and soluble E-selectin in serum, each of which reflect neutrophil involvement. Compared with FP250, SM50 reduced neutrophil number and human neutrophil lipocalin level in bronchial lavage fluid and intercellular adhesion molecule-1 level in bronchoalveolar lavage fluid. Compared with placebo, FP250 significantly reduced the numbers of (CD3+) T-lymphocytes, (CD4+) T-helper cells, (CD45RO+) activated T-helper cells and eosinophils in the biopsy samples; it also reduced the percentage of eosinophils and soluble intercellular adhesion molecule-1 in serum. The percentage of symptom-free days and nights and airways hyperresponsiveness improved significantly after SM50 compared to both placebo and FP250. In conclusion, a novel antineutrophilic effect of the inhaled long-acting beta2-adrenergic receptor agonist, salmeterol, in mild asthma is reported.

Effects of fluticasone propionate on inflammatory cells in COPD: an ultrastructural examination of endobronchial biopsy tissue.

BACKGROUND: Inhaled corticosteroids (ICS) markedly reduce bronchial mucosal inflammation in asthma but whether they have an anti-inflammatory effect in airway tissue in chronic obstructive pulmonary disease (COPD) is unknown. METHODS: A study of endobronchial biopsy samples was conducted as part of a double blind, placebo controlled, randomised trial of parallel design. Patients had mild to moderately severe COPD (FEV(1) 25-80% of predicted) and were given 3 months treatment with ICS, fluticasone propionate (FP; 500 micro g twice daily, n=14) or placebo (n=10). Biopsy tissue taken at baseline and after treatment was examined by transmission electron microscopy to count the numbers of all ultrastructurally distinct inflammatory cells. RESULTS: Compared with their baseline values, FP resulted in a significant decrease (on average 65%) in the numbers of mucosal mast cells (median 7.8 (range 1-33) v 2.8 (1-14), p<0.05). The reductive effect of FP held true when the post-treatment values of the placebo and FP groups were compared: 8.8 (1-24) v 2.8 (1-14) (p<0.05). Unexpectedly, there were significantly more neutrophils in the FP than in the placebo group: 4.0 (0-23) v 1.7 (0-8), respectively (p<0.05). There were no alterations to other cell types including mononuclear cells. Symptoms markedly improved in the patients treated with FP for 3 months. CONCLUSION: Fluticasone propionate given for 3 months to patients with COPD has selective effects on the inflammatory cells in the bronchial mucosa: the reduction in mast cell numbers may account for the improvement in symptoms over this time.

Different cytokine profiles in cryptogenic fibrosing alveolitis and fibrosing alveolitis associated with systemic sclerosis: a quantitative study of open lung biopsies.

Differences in the inflammatory response and prognosis of cryptogenic fibrosing alveolitis (CFA) and that associated with systemic sclerosis (FASSc) are beginning to emerge. It is hypothesized that these differences may be reflected in a distinct pattern of T-helper (Th)-1 and Th-2-type cytokines. Open lung biopsies were obtained from clinically well-documented cases of CFA and FASSc and, as a control, compared with grossly and histologically normal parenchyma obtained from smokers whose lungs were resected for cancer (n=5 in each group). In situ hybridization (ISH) was applied to the samples using anti-sense and sense 35S-labelled riboprobes to detect messenger ribonucleic acid (mRNA) for interleukins (IL)-2, IL-4, IL-5 and interferon (IFN)-gamma. Between 52-91% of cells expressing the cytokines studied were present in the alveolar interstitium rather than in lumenal cells or the alveolar epithelial lining. The highest values for all four cytokines were present in the patients with FASSc, i.e., 22-39 ISH positive cells x mm(-2) alveolar tissue compared with 1-19 cells x mm(-2) and 4-5 cell x mm(-2) in CFA and control subjects, respectively. Whereas the proportions of the four cytokines in FASSc were similar to the control subjects, IL-4 and IL-5 predominated significantly in CFA (p<0.001). For example, the ratio of IL-5 to IFN-gamma was 22:1 in CFA, significantly higher than in the cases with FASSc (2:1) or the control subjects (4:1) (p<0.05). In conclusion, cryptogenic fibrosing alveolitis is an inflammatory condition which is characterized, like asthma, by a predominance of gene expression for T-helper-2-type regulatory cytokines, whereas cryptogenic fibrosing alveolitis associated with systemic sclerosis appears to have a distinct mixed T-helper-1/T-helper-2 functional phenotype and a greater number of cells expressing each of these pro-inflammatory cytokines.

Cytolysis and piecemeal degranulation as distinct modes of activation of airway mucosal eosinophils.

BACKGROUND: Cytotoxic eosinophil granule proteins are considered important in the pathogenesis of inflammatory airway diseases, including asthma, rhinitis, and polyposis. However, little is known about the mechanisms involved in the deposition of these tissue-damaging granular products in vivo. OBJECTIVE: We sought to determine the occurrence of degranulating eosinophils, those with morphologic evidence of cytolysis with associated clusters of free eosinophil granules (Cfegs), and to identify the frequency of apoptotic eosinophils in inflamed upper airway tissue. METHODS: Eosinophil-rich nasal polyps were processed for transmission electron microscopy and for light microscopic evaluation of whole-mount preparations subjected to deep tissue staining for eosinophil peroxidase. RESULTS: The mean proportion of eosinophil subtypes were intact and resting (6.8%), intact but degranulating (83%), cytolytic or Cfegs (9.9%), and apoptotic (0.0%). All degranulating eosinophils exhibited piecemeal degranulation. The occurrence of Cfegs was confirmed in nonsectioned whole-mount preparations. Depending on the appearance of their core and matrix, the specific granules were divided into four subtypes, and a degranulation index (altered per total granules) was calculated for each eosinophil. Cytolytic eosinophils had a much lower degranulation index than intact eosinophils present in the same tissue (P < .001). CONCLUSIONS: These data indicate that eosinophil cytolysis is present in human airway mucosa, that its occurrence is not an artifact of the means of tissue handling, and that cytolysis of eosinophils may occur without prior extensive degranulation. We suggest that eosinophil cytolysis is a major activation mechanism, which occurs along with, but is distinct from, other types of degranulation.

Myofibroblast involvement in the allergen-induced late response in mild atopic asthma.

We undertook a detailed cellular and ultrastructural examination of bronchial biopsies from seven allergic asthmatic patients and 10 nonasthmatic control subjects (five atopic and five nonatopic) to determine the nature of the inflammation that occurs during allergen-induced late-phase responses (LPRs). The asthmatic subjects had mild asthma (FEV1 = 94 +/- 9% predicted; mean +/- SEM) and required only intermittent use of beta 2-agonists. Airway mucosal biopsy specimens were obtained on a single occasion from the nonasthmatic controls and on two occasions from the asthmatic subjects, at 24 h after diluent challenge and 24 h after challenge with allergen 3 wk later. The mean maximal decrease in FEV1 during the late response after allergen challenge was 30%, and that after administration of diluent was 4%. In coded plastic sections, subepithelial cells were counted with both light and electron microscopy, and the numbers present were expressed per 0.1 mm2 of tissue. Light microscopy revealed statistically significant increases in the total number of inflammatory cells (P < 0.02) and in "activated fibroblasts" after allergen challenge (P < 0.05). Electron microscopy showed significant increases after allergen challenge in the total number of eosinophils (P < 0.05) and cells with the ultrastructural features of myofibroblasts. The latter cells constituted 1.5% of cells after administration of diluent, and this increased to 15.5% after allergen challenge (P < 0.05). Mast cells were significantly more abundant in the atopic nonasthmatic controls than in the asthmatic subjects after allergen challenge. The study demonstrates that the profile of inflammatory cells in asthma at 24 h after allergen challenge is distinct from that in stable asthma and in nonasthmatic controls, and that migratory cells with a contractile phenotype appear in greater numbers in the late response. We propose that subjects who repeatedly develop a late response have increased numbers of migrating, contractile cells that may contribute to formation of the increased bronchial smooth-muscle mass observed in fatal asthma.