The correlational analysis assessment of exacerbation in bronchial asthma and treatment efficacy

Blood and sputum eosinophils, eosinophilic cation protein (ECP) in the serum and OPV1 were measured in 30 patients with atopic bronchial asthma (BA) of moderate severity showing eosinophilia at the beginning and the end of treatment week 1 and 4, respectively. In exacerbation of BA relative number of blood eosinophils averaged 10.4 + -1.4%, sputum 35.2 + -5.6%. Serum concentration of ECP, OPV1, IgE averaged 42.6% + -11.9%, 66.8 + -6.3%, 753.7 + -114 IU/ml, respectively. In exacerbation a strong correlation is noted between relative number of eosinophils in the blood and sputum, between the levels of IgE and ECP. At the end of the treatment OPV1 was higher while ECP level in the serum went down. Reduced eosinophilia in the blood and sputum correlated with OPV1 increment. In BA patients with high blood and sputum eosinophilia function of the lungs depends on eosinophilic number, while in normalization of blood eosinophil concentration and in a sharp fall of sputum eosinophil number OPV1 changes correlation with changes in ECP in the course of treatment. A close correlation between changes in eosinophil count, FVD indices, IgE and ECP levels during the treatment indicate relief of inflammation in BA patients.     

Eosinophilic inflammation in cough variant asthma

Eosinophils are considered to play a central pathogenetic role in asthma. We previously reported that sputum eosinophilia was observed in patients with cough variant asthma (CVA), as well as in "classic" asthma with wheezing. This study was undertaken to further investigate the involvement of eosinophils in CVA. The serum eosinophil cationic protein (ECP) level, the percentage of eosinophils in bronchoalveolar lavage (BAL) fluid, and the number of eosinophils in bronchial biopsy specimen were examined in 14 patients with CVA, 21 with classic asthma, and in seven healthy controls. For the two asthmatic groups, the clinical severity was classified with scores of 1-3. Pulmonary function and bronchial responsiveness were not significantly different between the patients with classic asthma and those with CVA. BAL, tissue eosinophil and serum ECP were all significantly increased in both classic asthma and CVA when compared with the controls but were not different between classic asthma and CVA. In both groups of asthmatics, the clinical severity significantly correlated with serum ECP and tissue eosinophils. In conclusion, eosinophilic inflammation is involved in cough variant asthma as well as in classic asthma. Anti-inflammatory treatment may be essential in patients with CVA, as in those with classic asthma.     

Induced sputum eosinophil cationic protein (ECP) measurement in asthma and chronic obstructive airway disease (COAD)

BACKGROUND: Induced sputum is a useful way to monitor airway inflammation in asthma, but cell counts are time-consuming and labour intensive. OBJECTIVE: The aim of this study was to evaluate a novel processing method using eosinophil cationic protein (ECP) as a biochemical marker of sputum eosinophil number and activation in subjects with asthma and other airway diseases. METHODS: Sputum was dispersed with dithiothreitol and centrifuged to yield cell free supernatant and a cell pellet. The pellet was treated with a cellular lysis buffer to release cell-associated ECP. ECP was measured in sputum supernatant and in the lysed cell pellet and was compared with sputum eosinophil counts in 31 adults with asthma, chronic obstructive airway disease (COAD), bronchiectasis and healthy controls. The ratio of supernatant to pellet ECP was evaluated as an index of eosinophil degranulation. The effect of sputum processing reagents and storage time on ECP measurement was also evaluated. RESULTS: ECP measured in the cell pellet lysate correlated closely with sputum absolute eosinophil counts across a range of subject groups (r = 0.72, P = 0.004). Sputum eosinophil counts were less well correlated with supernatant ECP levels (r = 0.54, P < 0.05). Incubation with dithiothreitol or lysis buffer did not influence ECP measurement and sputum ECP levels were stable over a 6-9 month period. Sputum supernatant and pellet lysate ECP concentrations were increased in stable asthma, asthma exacerbations and COAD/bronchiectasis (P < 0.05). The ratio of supernatant to pellet ECP was used as an index of eosinophil degranulation and found to be elevated in asthma exacerbations, COAD and bronchiectasis, but not in stable asthma. CONCLUSION: The measurement of ECP in the sputum cell pellet provides a reliable and efficient estimate of sputum eosinophil counts which can potentially be used in clinical trials and epidemiological surveys. The ECP ratio may be a useful marker of eosinophil activation, and was increased in asthma exacerbation and COAD. The increased ECP in COAD reflects a non-selective accumulation of eosinophils in this condition.     

Son of sevenless binds to the SH3 domain of src-type tyrosine kinase

Measurement of serum levels of ECP has been widely used for monitoring airway inflammation in bronchial asthma and recently been applied to measure anti-inflammatory effect of theophylline. However, reduced levels of ECP in theophylline-administered patients may express not only in vivo effect of theophylline but also in vitro effect after sampling because serum ECP measures released ECP during coagulation and theophylline has been reported to inhibit eosinophil degranulation in vitro. In order to answer the question, we tested whether theophylline added to blood after sampling reduces measured levels of serum ECP. Various concentrations of theophylline were added to SST tube, to which venous blood from atopic patients was drawn. Serum was, then, obtained by centrifugation after 15 min to 6 hours of incubation at room temperature. Theophylline significantly reduced serum ECP in a concentration-dependent manner. Percent reduction of ECP levels at 1 hour of incubation were 11.9%, 18.7%, 22.8%, and 51.7% at theophylline levels of 5, 12.5, 22.5, and 120 micrograms/ml, respectively. Kinetics of serum ECP release was also inhibited in the presence of theophylline. These results suggest that in vitro effect of theophylline on serum ECP levels should be considered when data of serum ECP in patients who take theophylline are interpreted.     

Effect of theophylline on CD11b and L-selectin expression and density of eosinophils and neutrophils in vitro

The nonspecific phosphodiesterase inhibitor theophylline, widely used in asthma therapy, may cause a decrease in inflammatory responses of airways. In asthma, eosinophils migrate to the airway wall and become activated. Activated eosinophils are characterized by low cell density, as well as increased expression of CD11b and reduced expression of L-selectin, two adhesion molecules involved in transendothelial migration. To study the anti-inflammatory effect of theophylline on granulocyte adhesion molecules in vitro, the platelet-activating factor (PAF)-induced density shift was determined by density centrifugation and the modulation of CD11b and L-selectin expression by flow cytometry on eosinophils and neutrophils in human whole blood. A relatively high concentration of theophylline (10(-3) M) inhibited the increase in the percentage of hypodense eosinophils and neutrophils in whole-blood samples after PAF stimulation in vitro. A more pharmacological concentration (10(-4) M) inhibited the CD11b upregulation and L-selectin shedding induced by PAF (10(-7) M) on both eosinophils and neutrophils. The effect of isoproterenol on the inhibitory effect of theophylline was mainly additive, but a small synergistic effect could not be excluded. In conclusion theophylline can attenuate eosinophil and neutrophil activation in vitro at the level of adhesion molecule expression and changes in cell density. This may have implications for transendothelial migration of these cells in asthma.     

The relationship of eosinophil viability enhancing activity in sputum and clinical symptoms in asthma

We studied the correlation of eosinophil viability enhancing activity (EVEA) in sputum from asthmatic children and clinical symptoms. Sputum from asthmatic children and equal volume of saline were mixed with a Vortex mixer and centrifuged at 40000 G. Clear supernatants were obtained and filtered with 0.22 micron membrane filter. Periphral blood eosinophils purified by Percoll density gradient centrifugation and CD16 negative selection/ immunomagnetic beads technique were incubated with sputum extract for 4 days. Eosinophil viability was examined by staining the cells with fluorescen diacetate and propidium iodide and expressed as eosinophil viability enhancing activity (EVEA). Eosinophil cationic protein (ECP) concentrations in sputum were also measured by a radioimmunoassay. Correlation between EVEA in sputum and pulmonary functions, attack score, treatment score, or sputum ECP was determined by Spearman correlation test. Sputum EVEA was correlated 1) inversely with pulmonary functions on sampling, 2) with attack score of 2 weeks period before sampling, 3) with treatment score of 1 month to 1 week before and 1 to 2 weeks after sampling, and 4) with sputum ECP in individual cases. Sputum EVEA may serve as a suitable parameter for monitoring airway inflammation in asthma.     

Long-lasting sensitization to food during the first two years precedes allergic airway disease. The MAS Study Group, Germany

Measurement of eosinophil percentages and ECP concentration in induced sputum may be useful in the diagnosis and assessment of the variability of airway inflammation in bronchial asthma (BA). To evaluate the usefulness of sputum eosinophil counts and ECP concentrations in the diagnosis of BA, we measured these parameters in 68 patients with respiratory complaints. In addition, we followed-up 14 BA patients with variable airflow limitation for 45.4 +/- 10.4 days. The BA group (n = 41) showed a higher percentage of sputum eosinophilia (24.5 +/- 7.6 vs. 2.2 +/- 2.9%, p < 0.001) and a higher level of sputum ECP (198.2 vs. 90.6 micrograms/L, p < 0.05) than those in the nonasthmatic group (NBA, n = 27). The sensitivity and specificity of sputum eosinophilia (> or = 5%) for the diagnosis of BA were 85.4% and 92.6%, respectively, which were better than the sensitivity (68.3%) and specificity (55.5%) of the increased level of sputum ECP (> or = 100 micrograms/L). Patients with moderate-to-severe persistent BA had a higher percentage of sputum eosinophil (n = 23, 34.6 +/- 10.6%) than those of mild persistent BA (n = 18, 10.7 +/- 5.2%, p < 0.01), but we could not find significant difference in ECP levels between mild persistent and moderate-to-severe persistent asthma. The percentages of sputum eosinophilia showed a moderate correlation with ECP (r = 0.4358, p < 0.01) and with the peak expiratory flow rate (PFR, r = -0.4746, p < 0.01) but sputum ECP did not correlate with PFR. In 14 BA patients who were followed, there was a relationship between changes of PFR and the percentage of sputum eosinophil (r = -0.7238, p < 0.01), but the change of PFR did not correlate with the change of sputum ECP levels. These results suggest that the sputum eosinophil count and sputum ECP level could be helpful in the diagnosis of BA, but that sputum ECP is not satisfactory for the assessment of variability of airway eosinophilic inflammation during the initial anti-inflammatory management of BA.     

Serum levels of eosinophil cationic protein and eosinophil protein x in pollen atopic patients with stable asthma and its relation with bronchial hyperresponsiveness

Eosinophils are important effector cells in allergic inflammation described in allergic rhinitis (AR) and allergic bronchial asthma (BA). During the pollen season serum levels of eosinophil cationic protein (ECP) and eosinophil X protein/eosinophil-derived neurotoxin (EPX/EDN) are increased in BA. The aim of the present study was to evaluate the serum levels of ECP and EPC in pollen atopic patients with AR and BA during the winter. 92 patients were studied. They were divided into three groups: I 29 patients with AR, II 51 patients with BA and III 12 healthy subjects. Allergic rhinitis and bronchial asthma were diagnosed by routine clinical tests: clinical history, skin tests, total IgE and specific IgE. In addition ECP and EPX were determined in serum. All patients were asymptomatic, stable and without medical treatment. Methacholine challenge test (MCT) was performed in all patients. MCT were positive in 4 patients of group I and 45 patients of group II. ECP levels (ug/l) were: 21 (I), 24 (II) and 7 (III). EPX levels (ug/l) were 35 (I), 45 (II) and 21 (III). Statistical differences (p < 0.01) were observed both in ECP and EPX levels in patients with MCT positive in relation to patients with MCT negative, and in allergic patients (I and II) in comparison with the healthy subjects (III) (p < 0.01). ECP and EPX serum levels are increased in patients with a positive MCT in the winter, out of the pollen season, when patients are asymptomatic, stable and without treatment. This fact suggests that eosinophils play an important role in the pathogenesis of bronchial asthma.     

Flow cytometric analysis for the activation of peripheral immunoregulatory cells from patients with bronchial asthma

By use of flow cytometry, we have investigated intracellular activated eosinophil cationic protein (ECP) in eosinophils and mitogen-induced cytokine production of T cells in peripheral blood from children with acute severe asthma. In addition, we measured ECP releasability (serum ECP/lysate ECP) as a maker of activated eosinophils. The monoclonal antibody EG2 (anti-activated ECP/EPX antibody) was used for measuring the amount of intracellular activated ECP. ECP releasability and mean fluorescence intensity (MFI) values of EG2-positive eosinophils increased at the time of asthmatic attack and reduced after treatment with improvement in peak expiratory flow. Furthermore, the frequency of T cells which produced IL-4, IL-5 and IFN-gamma stimulated with phorbol myristate acetate and ionomycin increased and reduced in parallel with MFI of EG2-positive cells. These observations suggest that flow cytometric analysis for intracellular ECP and mitogen-induced cytokine production reflects the activation of T cells in bronchial mucosa, and is useful for monitoring airway inflammation in bronchial asthma.     

The advantages of the lateral decubitus position after spinal anesthesia with hyperbaric tetracaine

Exercise-induced bronchoconstriction (EIB) is widely prevalent in asthmatic patients. Eosinophilic airway inflammation is considered to be a major factor in the pathogenesis of asthma. However, the effects of eosinophilic airway inflammation on EIB have been elucidated insufficiently. To examine the relationship between the severity of EIB and eosinophilic inflammation, sputum induction and exercise challenge were performed in 21 asthmatic patients. Significantly higher percentages of eosinophils and levels of eosinophil cationic protein (ECP) were found in induced sputum in EIB-positive asthmatics (median (range), eosinophils: 23.5 (11.0-61.0)%; ECP: 1,475 (74.8-17,701) ng x mL(-1)) than in EIB-negative asthmatics (eosinophils: 6.0 (1.0-41.5)% (p=0.006); ECP: 270.6 (10.8-7,700) ng x mL(-1) (p=0.049)). There was a significant correlation between the severity of EIB and the sputum eosinophil percentage (r=0.59, p=0.009) and the level of ECP (r=0.47, p=0.037). The area under the curve of the forced expiratory volume in one second for 30 min after exercise correlated with the percentage of eosinophils (r=0.60, p=0.008) and the level of ECP (r=0.45, p=0.04). There was no correlation between airway responsiveness to methacholine on the one hand and EIB, sputum eosinophils or ECP on the other. In conclusion, these results provide evidence that the severity of bronchoconstriction evoked by exercise is more closely related to eosinophilic airway inflammation than airway hyperresponsiveness to methacholine in asthmatic patients.     

Serum eosinophil cationic protein in infants during first wheezing episode

We measured serum ECP levels in infants during first wheezing episode. Serum ECP in these infants are significantly higher than in control infants, although much higher in children with asthma. Serum ECP in these infants with high serum IgE and/or positive RAST score are higher than in infants with normal serum IgE and negative RAST score. In children with bronchial asthma serum ECP is correlated with peripheral eosinophil counts, but in infants during first wheezing episode serum ECP is often elevated not associated with increased peripheral eosinophil counts. These suggest that activated eosinophils could be responsible for bronchoconstriction in wheezing patients with atopic diathesis even in very early phase and that these eosinophilic inflammations could contribute to formation of increased airway reactivity and bronchial asthma.     

Comparison of basophil histamine release, eosinophil cationic protein and non-specific airway responsiveness between mite-sensitive asthmatic and non-asthmatic children and non-allergic controls

To understand the relevance of allergy to the development of asthma in children, we examined basophil histamine release (HR) with Df antigen, blood eosinophil counts, serum eosinophil cationic protein (ECP) levels, and bronchial responsiveness to methacholine (PC20) in three groups of children, including 36 asthmatics with high RAST titre for Df (group 1), 36 non-asthmatics with similarly high RAST titre for Df (group 2) and 21 non-asthmatics with negative RAST titre for Df (group 3). The amount of Df antigen inducing 50% HR from basophils did not vary significantly between group 1 and 2 (P > 0.05), while none of the cells responded to higher concentrations of Df in group 3. The mean number of blood eosinophils and level of serum ECP were highest in group 1, and lowest in group 3, with group 2 being intermediate, and the differences were significant between all three groups (P < 0.01). The mean PC20 value was the lowest in group 1, intermediate in group 2, and the highest in group 3, and the differences were significant between all three groups (P < 0.01). While correlation studies showed that PC20 values of group 2 subjects significantly correlated with their eosinophil numbers (r = -0.48, P < 0.01) and ECP levels (r = -0.49, P < 0.01), such correlations were not found in group 1 subjects. These results suggest that the degree of the eosinophilic inflammation caused by the allergic reaction to mites is an important factor in determining the clinical expression of asthma in atopic subjects.     

Eosinophil cationic protein in the asthmatic infant: correlation with the clinic and pulmonary function

PATIENTS AND METHODS: Serum eosinophil cationic protein (ECP) was measured in 99 chronic asthmatic patients (51 males and 48 females) with a mean age of 10.59 years and correlated with the number of eosinophils, lung function, symptoms in the last 6 months and clinical scoring (that reflecting the clinical situation during the last 15 days). RESULTS: Serum ECP showed a significant correlation with the total number of eosinophils (p < 0.001, R = 0.44), clinical scoring (p < 0.05, R = 0.26), number of inhaled beta 2-agonist doses needed in the last 15 days (p < 0.05, R = 0.26), forced expiratory volume during 1 second (FEV1; p < 0.01, R = -0.27), forced vital capacity (FVC; p < 0.05, R = -0.23), maximal mid-expiratory flow (FEF25-27; p < 0.001, R = -0.37). However, there was no significant correlation between the total number of eosinophils and the clinical situation of the children or the FEV1, but we found a significant correlation with the FEF25-27. Patients with ECP < 20 had better results on lung function tests than patients with ECP > 20 (FEV1: 108.89 +/- 17.7 vs 100.5 +/- 22 (p < 0.05), FEF25-27: 93.81 +/- 24.4 vs 75.21 +/- 24.5 (p < 0.001). CONCLUSIONS: The findings of this study suggest that the ECP level is a good marker of the situation of asthma in childhood. The levels of ECP will probably be able to help us to evaluate the degree of bronchial inflammation that neither the clinical state nor the lung function define completely.     

Persistence of sputum eosinophilia in children with controlled asthma when compared with healthy children

We aimed to describe induced sputum cell counts in healthy nonasthmatic children, and to compare these to children with controlled and uncontrolled asthma. Following clinical assessment and spirometry, ultrasonically nebulized hypertonic saline was used to induce sputum from children with asthma (n=50) and without asthma (n=72). Sputum was dispersed and cell counts performed to yield total and differential cell counts. Specific stains were used for eosinophil and mast cell counts. All of the children with asthma were receiving inhaled and/or oral corticosteroids. Current asthma control was assessed in terms of symptoms and lung function. Children were classified as controlled on inhaled corticosteroids (no current symptoms, normal lung function n=15), current symptomatic asthma (n=16) and asthma exacerbation (n=11). It was found that eosinophils comprised a median 0.3% (interquartile range (IQR): 0, 1.05) of cells in sputum from healthy children. Sputum eosinophils (4.3% (IQR: 15, 14.1) p=0.0005) and epithelial cells (14% (IQR: 6, 19.4) p=0.0005) were significantly higher in children with asthma than in nonasthmatic children. Children whose asthma was controlled, as well as those with symptoms, had more sputum eosinophils and epithelial cells than the nonasthmatics. Mast cells were found in the sputum of only four of the 42 children with asthma. This study demonstrates that eosinophilic airway inflammation and epithelial damage can occur in children with asthma. Airway inflammation persists even in those children who are receiving inhaled corticosteroids, have normal lung function and good symptomatic control of their disease.     

Effects of PAF, FMLP and opsonized zymosan on the release of ECP, elastase and superoxide from human granulocytes

Platelet-activating factor (PAF) is a potent chemoattractant for human eosinophils and neutrophils and causes eosinophil and neutrophil recruitment into animal airways. Since eosinophils and eosinophil cationic proteins are thought to play an important role in the pathophysiology of asthma, we have examined the hypothesis that PAF may also stimulate eosinophil cationic protein (ECP) release from human granulocytes. Granulocytes (93% neutrophils, 3% eosinophils) were isolated from the blood of normal volunteers, using metrizamide density gradients, and stimulated in vitro with PAF, L-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) or opsonized zymosan (OPZ). Superoxide generation was measured colorimetrically, granulocyte degranulation by a fluorimetric assay for elastase, and eosinophil activation by specific radioimmunoassay (RIA) for ECP. Granulocyte chemotaxis was also measured. Whilst both PAF and FMLP were potent chemoattractants for human mixed granulocytes (concentrations producing half the maximal effect (EC50s) ca 10 nM), PAF at concentrations below 10 microM was a poor stimulus to superoxide generation, elastase release or ECP release from the same cell population. In contrast, FMLP was a potent stimulus to both superoxide generation (EC50 48 nM) and ECP (EC50 ca 100 nM) and elastase release (EC50 ca 1 microM). OPZ was a potent stimulus to superoxide generation, but was a poor stimulus to ECP or elastase release. Thus, although PAF is a potent chemoattractant for human granulocytes, our results suggest that it alone may not stimulate their subsequent activation and release of cytotoxic products.     

Potential masking effects of salmeterol on airway inflammation in asthma

We hypothesized that regular use of long-acting beta-agonists could delay recognition of ("mask") increasing airway inflammation. We studied steroid-sparing and "masking" effects of salmeterol versus placebo in 13 asthmatic individuals requiring >= 1,500 microgram inhaled corticosteroid daily. Corticosteroid doses were reduced weekly until criteria were met for an exacerbation or the corticosteroid was fully withdrawn. Subjects were restabilized on their original dose of inhaled corticosteroid for 4 wk before crossover to the alternative treatment. Subjects maintained symptom and peak expiratory flow (PEF) diaries, and underwent weekly spirometric, methacholine challenge, sputum eosinophil, and serum eosinophil cationic protein (ECP) measurements. Mean corticosteroid dose was reduced by 87% during salmeterol treatment, versus 69% with placebo (p = 0.04). Sputum eosinophils increased before exacerbation despite stable symptoms, FEV1, and PEF. In the week before clinical exacerbation, sputum eosinophil counts were higher in the salmeterol-treatment arm (19.9 +/- 29.8% [mean +/- SD], versus placebo 9.3 +/- 17.6%; p = 0.006). Five subjects showed > 10% sputum eosinophilia before exacerbation during salmeterol treatment, as compared with two receiving placebo. In this model, salmeterol controlled symptoms and lung function until inflammation became significantly more advanced. We conclude that the bronchodilating and symptom-relieving effects of salmeterol can mask increasing inflammation and delay awareness of worsening asthma.     

Human peripheral eosinophils express functional interferon-gamma receptors (IFN-gammaR)

In order to determine whether or not IFN-gammaR is associated with regulatory mechanisms on human eosinophil function, we examined the expression of functional IFN-gammaR on human peripheral eosinophils. In this study, peripheral blood eosinophils were obtained from seven normal controls and 12 patients (bronchial asthma, n = 9, and hypereosinophilic syndrome (HES), n = 3), and the purity of eosinophils was 97.11 +/- 2.31%, n = 19. We first showed that anti-IFN-gammaR alpha-chain MoAb reacted with all tested eosinophils of both normal controls and patients by flow cytometry analysis. We also showed expression of mRNA for the alpha-chain of IFN-gammaR in all purified eosinophils of six individuals. Further, to characterize IFN-gammaR on eosinophils, we did binding experiments with 125I-IFN-gamma on purified peripheral eosinophils. The linear Scatchard plot indicated a single type of high-affinity binding sites (dissociation constant (Kd) = 3.89-4.95 x 10(-10) M, numbers of binding sites = 183-233/cell, n = 3). To determine whether IFN-gammaR on eosinophils is functional, we examined surface eosinophilic cationic protein (ECP) and CD69 induction after IFN-gammaR ligation with recombinant human IFN-gamma (rhIFN-gamma) on eosinophils by flow cytometry. rhIFN-gamma stimulation significantly induced both ECP and CD69 expression on the 2-18 h-cultured eosinophils in a dose-dependent manner. Further, the effects of rhIFN-gamma stimulation were significantly blocked by both a neutralizing anti-IFN-gamma MoAb and a blocking anti-IFN-gammaR MoAb. These results suggest that human peripheral eosinophils express functional IFN-gammaR.     

An inhaled steroid improves markers of airway inflammation in patients with mild asthma

Airway inflammation can be demonstrated in mildly asthmatic patients who are not treated with inhaled steroids. Current guidelines recommend that inhaled steroids should be introduced in mild asthmatics who use an inhaled beta2-agonist more than once daily. It was postulated that inhaled steroids can have anti-inflammatory effects in patients with even milder disease. The effect of 4 weeks of treatment with budesonide (800 microg twice daily by Turbohaler) was studied in 10 steroid-naive mildly asthmatic patients (forced expiratory volume in one second (FEV1) = 96+/-1.4% predicted) who required an inhaled beta2-agonist less than one puff daily, in a double-blind, placebo-controlled, crossover fashion. Spirometry, exhaled nitric oxide (NO), bronchial responsiveness (provocative concentration causing a 20% fall in FEV1 (PC20)), and sputum induction were performed before and after each treatment period. Following budesonide treatment, there were significant improvements in FEV1, and PC20, in association with a significant reduction in the percentage of eosinophils in induced sputum. Exhaled NO levels tended towards reduction, but the change was nonsignificant. There were also nonsignificant reductions in sputum eosinophil cationic protein and tumour necrosis factor-alpha levels. In conclusion inhaled budesonide can lead to improvements in noninvasive markers of airway inflammation, in association with a small improvement in lung function, even in mildly asthmatic patients who require an inhaled beta2-agonist less than once daily. This suggests a potential benefit of inhaled corticosteroids, even in relatively asymptomatic asthma.     

Inhibitory effects of formoterol on platelet-activating factor induced eosinophil chemotaxis and degranulation

A new long-acting beta 2-agonist, formoterol, has been reported to have a greater efficacy and duration of action in asthmatic patients as compared to conventional beta 2-agonists. We recently demonstrated that formoterol inhibited antigen-induced late asthmatic response (LAR) and accompanying airway eosinophilia in guinea pigs. In this study, we investigated the direct effect of formoterol in vitro on human eosinophil function, focusing on platelet-activating factor (PAF)-induced eosinophil chemotaxis and eosinophil cationic protein (ECP) release. Purified normodense eosinophils were separated by discontinuous gradient from 12 mild asthmatic patients. Formoterol in concentrations of 1-100 microM significantly inhibited PAF-induced eosinophil chemotaxis in a dose-dependent manner with a concentration of drug required to produce 50% inhibition (IC50) of 10.16 microM; % inhibition: 22.9 +/- 13.0% (1 microM), 51.6 +/- 12.7% (10 microM), 75.0 +/- 11.3% (100 microM). When formyl-methionyl-leucyl-phenylamine (FMLP) was used as a chemoattractant, a similar inhibition of eosinophil chemotaxis by formoterol was observed; % inhibition: 13.1 +/- 5.0% (1 microM). 47.7 +/- 7.6% (10 microM), 65.5 +/- 16.5% (100 microM). A conventional beta 2-agonist, salbutamol, at doses to 100 microM did not show any inhibitory effects on PAF-induced eosinophil chemotaxis. Formoterol in concentrations of 1-100 microM also significantly inhibited PAF-induced ECP release from eosinophils; % inhibition: 21.7 +/- 9.0% (1 microM), 39.3 +/- 7.4% (10 microM), 39.6 +/- 8.4% (100 microM). In the presence of phosphodiesterase inhibitors, theophylline or isobutylmethyl xanthine (IBMX), the inhibition by formoterol on PAF-induced ECP release was enhanced.(ABSTRACT TRUNCATED AT 250 WORDS)     

Suppressive effect of corticosteroids on the gene expression of interleukin-5 and eosinophil activation in asthmatics

Although cortico steroids are effective anti-inflammatory agents in ameliorating asthma symptoms and bronchial hperreactivity, their mechanism of action is unknown. Interleukin (IL)-5 is known to play a key role in regulating eosinophil proliferation and activation. Therefore, we examined the changes of IL-5 mRNA expressions in PBMC semi-quantitatively with RT-PCR as well as serum ECP levels and MCH-PC20 values in asthmatics before and after being treated with corticosteroids. The results revealed that there were significant decrease in the level of IL-5 mRNA and serum ECP concentration after therapy (P < 0.05) and there was remarkable improvement in the values of MCH-PC20 and FEV1% (P < 0.05). It was also found that the changes of serum ECP levels or MCH-PC20 values were accompanied by a reduction in IL-5 mRNA expression (r = 0.5426 or 0.4857, P < 0.05). These results suggested that the therapeutic effects of corticosteroids in asthma may result from modulation of IL-5 gene expression with consequent inhibition of eosinophil activation.