Airway inflammation in asthma and perennial allergic rhinitis. Relationship with nonspecific bronchial responsiveness and maximal airway narrowing

BACKGROUND: Eosinophilic airway inflammation is the hallmark of asthma, but it has also been reported in other conditions such as allergic rhinitis. We have tested whether the analysis of cells and chemicals in sputum can distinguish between patients with mild allergic asthma, those with allergic rhinitis, and healthy controls. The relationship between inflammation markers in sputum and nonspecific bronchial hyperresponsiveness to methacholine (BHR) (PD20 and maximal response plateau [MRP] values) was also evaluated. METHODS: We selected 31 mild asthmatics and 15 rhinitis patients sensitized to house-dust mite. As a control group, we studied 10 healthy subjects. Every subject underwent the methacholine bronchial provocation test (M-BPT) and sputum induction. Blood eosinophils and serum ECP levels were measured. Sputum cell differentials were assessed, and eosinophil cationic protein (ECP), tryptase, albumin, and interleukin (IL)-5 levels were measured in the entire sputum supernatant. RESULTS: Blood eosinophils and serum ECP levels were higher in asthma patients and rhinitis than in healthy controls, but no difference between asthma patients and rhinitis patients was found. Asthmatics had higher eosinophil counts and higher ECP and tryptase levels in sputum than rhinitis patients or control subjects. Sputum albumin levels were higher in asthmatics than in controls. Rhinitis patients exhibited higher sputum eosinophils than healthy controls. An association between sputum eosinophil numbers and MPR values (r= -0.57) was detected, and a trend toward correlation between sputum ECP levels and PD20 values (r= -0.47) was found in the rhinitis group, but not in asthmatics. No correlation between blood eosinophilic inflammation and lung functional indices was found. CONCLUSIONS: Induced sputum is an accurate method to study bronchial inflammation, allowing one to distinguish between rhinitis patients and mildly asthmatic patients. The fact that no relationship was detected between sputum inflammation and BHR suggests that other factors, such as airway remodeling, may be at least partly responsible for BHR in asthma.     

Serum eosinophil cationic protein (ECP) as a marker of disease activity and treatment efficacy in seasonal asthma

This study was carried out to determine whether serum eosinophil cationic protein (ECP) represents a sensitive marker for disease activity in atopic asthmatic patients during the pollen season. The study, in double-blind fashion, was performed between February and June 1994. Two groups of 10 seasonal asthmatic patients randomly received two different treatments. The first group was treated with inhaled beclomethasone dipropionate (BDP) 500 μg bid; the second received a matched placebo (P). At the beginning and every month, blood samples for determination of ECP and eosinophil count were collected and lung function (FEV₁) and methacholine responsiveness (PD₂₀) were performed. Subjects recorded daily symptoms of asthma, salbutamol consumption, and peak expiratory flow (PEF) values. In the P group, all indices, except FEV₁, showed significant changes during the pollen season ( P < 0.001). In the BDP group, significant changes were detected for symptom score ( P < 0.01), salbutamol consumption ( P < 0.01), and eosinophil number ( P < 0.05). Between the two groups, significant differences for symptom score ( P < 0.001), salbutamol consumption ( P < 0.001), ECP levels ( P < 0.05), eosinophil count ( P < 0.02), PD₂₀ methacholine ( P < 0.02), and PEF values ( P < 0.01) were detected. Changes in serum ECP significantly correlated with changes in other parameters ( P < 0.001), except FEV₁. Our results provide evidence that serum ECP is a sensitive marker for monitoring of the disease activity in seasonal asthma. Furthermore, it may offer a useful tool for estimating treatment efficacy.     

Intracellular expression and serum levels of eosinophil peroxidase (EPO) and eosinophil cationic protein in asthmatic children

BACKGROUND: Eosinophils are involved in the chronic inflammatory response in asthma and their basic proteins are thought to play a major pathophysiological role in this process. While serum levels of basic proteins have been used to monitor the ongoing allergic disease, little is known about the intracellular expression of these proteins in clinical situations. OBJECTIVE: The aim of the study was to determine the intracellular expression of eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) in asthmatic children and control subjects and relate it to serum levels of both proteins, lung function tests and immunoglobulin (Ig)E levels. METHODS: Serum ECP and EPO concentrations were determined by immunoassays in 13 asthmatic children (mean age: 9 +/- 1 years, mean FEV1: 92 +/- 10% predicted, geometric mean PC20 histamine 0.5 mg/mL) and 10 age-matched, healthy control subjects. A flow cytometric single cell assay was employed to detect intracellular ECP and EPO in peripheral blood eosinophils. RESULTS: While serum concentrations of both ECP (asthma: median 15.0 microg/L [range 3.6-57.7] vs control: 5.9 microg/L [2.7-9.1]; P = 0.02) and EPO (22.9 microg/L [5.2-82.5] vs 7. 2 microg/L [2.5-12.7]; P = 0.008) were significantly elevated in asthmatics, the intracellular expression of ECP and EPO (measured as mean fluorescence intensity) was decreased (EG1: 55.3 [17.7-120.8] vs 100.3 [46.5-264.4]; P = 0.01; EG2: 80.2 [24.1-135.3] vs 133.7 [32. 1-244.9]; P = 0.04 and EPO: 49.7 [23.1-155.8] vs 94.9 [28.8-115.2]; P = 0.03). In asthmatics there was a significant correlation of FEV1 with intracellular ECP and of bronchial hyperresponsiveness with serum EPO and ECP. Furthermore, total IgE levels were positively correlated with serum EPO only. CONCLUSION: We conclude that in asthmatics the intracellular content of ECP and EPO in peripheral eosinophils is reduced possibly due to degranulation. Epitope masking in activated eosinophils or a shift to early bone marrow-derived progenitors with less granule proteins are further possible explanations.     

Bronchial hyper-responsiveness to hypertonic saline and blood eosinophilic markers in 8–13-year-old schoolchildren

BACKGROUND: In adult asthma, bronchial hyper-responsiveness (BHR) to indirect stimuli reflects eosinophilic activation more closely than BHR to stimuli that directly cause smooth muscle contraction. AIM: To assess the relationship between BHR to the indirect stimulus hypertonic saline (HS), blood eosinophil numbers, and serum eosinophilic cationic protein (ECP) in children with and without current wheeze. METHODS: A cross-sectional survey among 8-13-year-old schoolchildren, using the International Study of Asthma and Allergic disease in Childhood questionnaire, bronchial challenge with HS, skin prick tests, serum IgE, blood eosinophil counts and ECP (in a subset). Based upon the presence of current wheeze (WHE) and BHR, we defined three case groups (WHE+BHR+, WHE-BHR+, WHE+BHR-) and the reference group (WHE-BHR-). By regression analyses, each case group was compared with the reference group for differences in atopic sensitization, blood eosinophil counts and serum ECP. RESULTS: Complete data were obtained for 470 children. BHR was present in 103 children (22%), 66 being asymptomatic and 37 symptomatic. Children of all three case groups were more often atopic. Sensitization to indoor allergens particularly occurred in children with BHR, irrespective of symptoms (P < 0.05). Children with WHE+BHR+ had highest values for blood eosinophils and serum ECP (P < 0.05). Children with WHE-BHR+ had less severe responsiveness. In atopic children with WHE-BHR+, serum ECP was higher than in children with WHE-BHR-(P < 0.05). CONCLUSIONS: BHR to HS is associated with blood markers of eosinophilic activation, particularly in atopic children.     

Effects of immunotherapy on the inflammation in pollen asthma

Seasonal asthma is a natural model of airway inflammation where amount of airborne antigen have direct impact and correlates to the clinical disease and degree of inflammation. Bronchial hyperresponsiveness (BHR) is an indirect measure of the degree of airway inflammation and the seasonal increase paralleling clinical disease has been shown in a number of studies. Using a model of seasonal asthma in birch pollen sensitive individuals we intended to prove the anti-inflammatory potential of immunotherapy (IT). Forty birch pollen-allergic patients, 20 IT-treated and 20 untreated participated in a series of studies. BHR expressed as PCzo histamine increased in all patients during the season although most in untreated controls; the difference between the groups was p <0.07. The level of eosinophil cationic protein (ECP) rose in untreated, but not IT-treated, patients during the season (p <0.05). Significant increase in eosinophil chemotactic activity (ECA) in serum of untreated patients during the season was noted. IT-treatment abrogated this response. After 2 years of treatment bronchoalveolar lavage (BAL) was performed on 12 patients (6 in each group). IT-treatment prevented seasonal rise of eosinophil numbers in peripheral blood (PB) and the lung while in the untreated group the increase was significant in both compartments (p <0.05 and p<0.01, respectively). At the same timc, significant increment in ECP and ECA levels in BAL wcre rccordcd in untreated patients comparcd with IT-treated (p <0.05. p <0.01, respectively). It is concluded that IT proved its anti-inflammatory effect by diminishing degree of BHR, prcventing attraction. accumulation and activation of eosinophils in the lung of allergic I asthmatics.     

Granulocyte proteins in serum in childhood asthma: relation to spirometry and therapy

Background Measurement of markers of eosinophil activation in asthmatics provides information indicative of ongoing inflammatory processes in the airways. Objectives This study was eonducted to determine the correlations between serum markers of allergie inflammation with spirometry parameters in asthmatic children in different treatment groups. Methods Blood eosinophils. serum levels of eosinophil cationic protein (ECP). eosinophil protein X (EPX), myeloperoxidase (MPO) and tryptase were measured simultaneously with serial measurements of FEV₁/FVC, FEF_25–75 and FEF in 60 children with acute asthma on admission and after 2, 14, 30 and 60 days. Group A received bronchodilators only (n= 20). group B received sodium cromoglycate (SCG) (n= 20) and group C received oral and/or inhaled corticosteroids (n= 20). Results Oral steroid treatment (2 mg /kg/day). given at the onset of the asthma attack, resulted in significant reduction in the ECP and EPX levels in all the children. However, these reduced ECP and EPX levels were not sustained in the children, even in those who continued on maintenance steroid treatment. Significant, but inconsistent, correlations between ECP, EPX with total eosinophil count, percentage eosinophils and spirometry parameters were observed at the different time-points. Tryptase levels were normal in all subjects. There were no significant correlations between myeloperoxidase levels and the spirometry parameters or eosinophil parameters. Serial monitoring of ECP and EPX levels was found to be of some use in predicting clinical outcome in certain steroid-dependent asthmatics (group C) but of no value in the mild asthmatics (group A). Conclusion While elevation of ECP, EPX and MPO in the serum of childhood asthmatics suggests ongoing inflammation and may inversely correlate with spirometry parameters in some patients, the relationship between these markers and airway function is not a simple one.     

Serum eosinophil granule proteins predict asthma risk in allergic rhinitis

Background: Allergic rhinitis is a common disease, in which some patients will deteriorate or develop asthma. It is important to characterize these patients, thereby offering the possibility for prevention. This study evaluated eosinophil parameters as potential indicators of deteriorating allergic airway disease. Methods: The subjects of the study included all patients who suffered seasonal allergic rhinitis and had participated in a study 6 years earlier, in which blood eosinophils, serum eosinophil cationic protein (ECP) serum eosinophil peroxidase (EPO), nasal lavage ECP and nasal lavage EPO levels were measured. Patients in the present study were interviewed on occurrence of rhinitis symptoms during the last season, rhinitis outside season, asthma‐like symptoms and asthma diagnosis, and were skin‐prick tested for common aeroallergens. Eosinophil parameters from the study 6 years earlier were then tested for the ability to predict occurrence of new allergies, worsening of rhinitis and occurrence of asthma. Results: Forty‐four patients participated in the study. In four patients seasonal rhinitis symptoms had deteriorated, 10 had experienced perennial rhinitis symptoms, 14 reported asthma‐like symptoms and seven had been diagnosed with asthma. Thirteen had developed additional sensitization. Patients developing asthma‐like symptoms compared with patients with no such symptoms had significantly higher serum ECP (16.7 μg/l vs 8.2 μg/l; P ≤ 0.01) and serum EPO (17.9 μg/l vs 8.8 μg/l; P ≤ 0.05). Results were similar, considering patients diagnosed with asthma. Blood eosinophils and nasal lavage parameters were not related to development of asthma and asthma‐like symptoms. No eosinophil parameter was related to deterioration of rhinitis or additional sensitization. Conclusion: Serum ECP and EPO in patients with seasonal rhinitis demonstrated a high predictive ability for later development of asthma.     

Eosinophil chemoattractants in the middle ear of patients with eosinophilic otitis media

BACKGROUND: Patients with intractable otitis media associated with bronchial asthma have an extensive accumulation of eosinophils in the effusion and mucosa of the middle ear; this condition is called eosinophilic otitis media (EOM). It remained to be determined how eosinophils accumulate in the middle ear. OBJECTIVES: To clarify the pathogenesis of middle ear diseases, we measured the concentration of eosinophil chemoattractants in middle ear effusion (MEE), and carried out immunohistochemical studies of middle ear mucosa specimens to demonstrate the expression of eosinophil chemoattractants. METHODS: Middle ear effusion samples were obtained from 15 EOM patients with bronchial asthma and from six controls for the measurement of eosinophil cationic protein (ECP), IL-5, eotaxin and regulated on activation, normal T expressed and secreted concentrations. Middle ear mucosa samples were also taken from 14 EOM patients and 16 controls for immunohistochemical study. In 10 EOM patients, the numbers of immunoreactive cells as well as apoptotic cells were determined before and after the topical application of triamcinolone acetonide into the middle ear. RESULTS: In EOM, significantly higher ECP and IL-5 concentrations were detected in MEE than in serum, and ECP, IL-5 and eotaxin concentrations in MEE were higher in the EOM patients than in the controls. ECP concentration positively correlated with that of IL-5. Immunohistochemically, the numbers of cells positive for EG2 and ecalectin were significantly higher in the EOM patients than in the controls. After the topical application of triamcinolone acetonide, the numbers of infiltrating cells and immunoreactive cells distinctly decreased, whereas the number of apoptotic cells significantly increased. CONCLUSION: In EOM, locally produced IL-5 may play a crucial role in the accumulation of eosinophils in the middle ear. Chemokines such as ecalectin and eotaxin are also produced in the middle ear, and help activate and enhance the survival of eosinophils to induce the intractable condition in the middle ear. The topical application of triamcinolone acetonide induces the apoptosis of not only eosinophils but also eosinophil chemoattractant-producing cells, thereby improving the middle ear condition.     

Corticosteroid resistance in mild asthma: markers of persistent inflammation.

BACKGROUND: Bronchial hyperresponsiveness (BHR) is an important feature of asthma. Glucocorticosteroids (GCS) reduce BHR, probably by suppressing allergic inflammation. There are, however, two groups of asthmatics with either GCS-responsive or non-responsive BHR to methacholine. We investigated the mechanism of non-GCS-responsive BHR in mild asthma. METHODS: Non-GCS-responsive BHR asthma was defined as failure of reduction of BHR to methacholine after a 2-week course of oral prednisolone (30 mg/day). The expression of interleukin (IL)-4, IL-5, IFN-gamma mRNA in peripheral blood mononuclear cells, eosinophil count, serum cortisol, eosinophilic cationic protein (ECP), and spirometry were measured in five non-GCS-responsive BHR asthmatics and six patients with GCS-responsive BHR asthma before and after prednisolone therapy. RESULTS: With the exception of serum ECP and expression of IL-5 mRNA, no significant differences were observed between GCS-responsive BHR and non-GCS-responsive BHR asthma. The mean ECP level was significantly higher in non-GCS-responsive BHR than in GCS-responsive BHR asthma before and after prednisolone therapy. Interleukin-5 mRNA was detected in all asthmatics before prednisolone therapy; however, after prednisolone therapy, IL-5 mRNA was only detected in non-GCS-responsive BHR asthmatics. CONCLUSIONS: Our findings suggest that activation of eosinophils appears to persist in some asthmatics with non-GCS-responsive BHR due to continuous IL-5 production by lymphocytes.     

Application of monoclonal antibodies against major basic protein (BMK-13) and eosinophil cationic protein (EG1 and EG2) for quantifying eosinophils in bronchial biopsies from atopic asthma

A monoclonal antibody prepared against the eosinophil major basis protein (MBP) was compared with the anti-eosinophil cationic protein (ECP) antibodies (EG1 and EG2) in immunostaining of bronchial biopsies from atopic asthma and controls. Anti-MBP (designated BMK-13) did not cross-react with other eosinophil basic proteins (i.e. ECP, eosinophil peroxidase [EPO] or eosinophil-derived neurotoxin [EDN]) and stained more than 98% of peripheral blood eosinophils irrespective of their degree of activation. EG2 stained 15% of resting and 75% of activated eosinophils; EG1 recognized 74% and 78% of resting and activated cells, respectively. The numbers of BMK-13, EG1 or EG2-positive staining cells in bronchial biopsies from asthma were significantly greater than atopic non-asthmatics (P less than 0.02, P less than 0.01 and P less than 0.05, respectively) and normal non-atopic controls (P less than 0.001). For each of the various groups studied, the rank order for the number of eosinophils stained was BMK-13 greater than EG1 greater than EG2. BMK-13 stained significantly more cells from bronchial biopsies of atopic asthma and atopic non asthma when compared to EG2 (P less than 0.001 and P less than 0.05, respectively). Since only a proportion of BMK-13+ cells were EG2+, these results suggest that not all tissue eosinophils are actively secreting. Thus, BMK-13 can serve as a useful pan-eosinophil marker in tissue sections since it appears to stain most eosinophils.     

Assessment of eosinophil granule proteins in various body fluids: is there a relation to clinical variables in childhood asthma?

BACKGROUND: The eosinophil plays a central role in the inflammatory process in bronchial asthma. Recent studies have indicated that the assessment of eosinophil-derived proteins in various body fluids could be used for monitoring disease activity of childhood asthma. Till now, no study exists which compared the levels of eosinophil-derived proteins in various body fluids such as serum, nasal lavage fluid (NALF) and urine. OBJECTIVE: To investigate whether eosinophil granule proteins in different compartments were correlated and whether there is a relationship between disease activity, pulmonary function and bronchial hyperreactivity. METHODS: Twenty-eight children with atopic bronchial asthma were recruited. Serum, NALF and urine samples were obtained and assessed for eosinophil cationic protein (ECP) and eosinophil protein X (EPX). The levels of eosinophil proteins were analysed for a relationship with lung function variables, bronchial hyperreactivity and disease activity. Eleven healthy control subjects were used as controls. RESULTS: Median ECP and EPX concentrations in serum (31.4 and 74.8 microg/L vs 15.8 and 24.3 microg/L, respectively), NALF (9.9 and 44. 9 microg/L vs 0 and 2.5 microg/L, respectively) and urine (49.4 vs 16.5 microg/mmol creatinine) were significantly raised in children with bronchial asthma compared with healthy control subjects. In addition, ECP and EPX levels in serum and urine samples were significantly higher in symptomatic patients compared with asymptomatic subjects with asthma. Although no relationship between eosinophil-derived proteins in serum, NALF or urine and the level of nonspecific bronchial hyperreactivity could be detected, the concentrations of EPX in serum and urine were correlated with variables of pulmonary function. CONCLUSION: Our findings demonstrate increased eosinophil activity in serum, NALF and urine derived from children with bronchial asthma. Due to the relationship between levels of eosinophil proteins in serum/urine samples and lung function, as well as significant concentration differences between symptomatic and asymptomatic asthmatic children, the assessment of eosinophil proteins in serum or urine samples appear to be more appropriate in monitoring disease activity than measurement of ECP or EPX in NALF. Thus, the determination of serum ECP/EPX or urinary EPX may be preferentially used in monitoring eosinophilic inflammation in childhood asthma.     

Eosinophil cationic protein in patients with bronchial asthma]

To evaluate the role of eosinophils in the pathogenesis of bronchial asthma, we measured eosinophil cationic protein (ECP), one of the eosinophil granule proteins. Serum ECP levels were measured by radioimmunoassay in asthmatic (n = 59) and non-asthmatic (n = 47) patients. Preliminary study showed that ECP levels were time-dependently increased in the blood samples until 3 hr. Based on the findings, we determined to measure serum ECP levels at 30 min after blood sampling. Serum ECP levels and blood eosinophil counts in asthmatic patients were significantly higher than those in non-asthmatic patients (p less than 0.01). There was also a positive correlation between serum ECP levels and blood eosinophil counts in patients with asthma (r = 0.46, p less than 0.001). No significant difference was observed in either serum ECP levels or blood eosinophil counts in asthmatic patients classified by clinical type and severity. Blood eosinophil counts in patients with asthma attacks were significantly greater than in those in remission (p less than 0.05), but no significant difference was observed in serum ECP levels between these groups, suggesting an enhanced elimination of ECP during attack. Serum alpha-2 macroglobulins, which bind to ECP and may function as scavengers for ECP, were not significantly different in these group. These results suggest that serum ECP levels may not be a direct indicator of eosinophil activation or degranulation in the pathogenesis of asthma.     

Serum eosinophil cationic protein in the evaluation of asthma severity in children

To assess the sensitivity and specificity of serum eosinophil cationic protein (ECP) in the diagnosis of asthma and evaluation of asthma severity, we conducted a prospective study to compare parameters of asthma severity, peripheral blood eosinophilia, and serum ECP concentrations in 88 children presenting to a university hospital outpatient clinic with suspected ( n =59) or recently diagnosed asthma ( n =29). Serum ECP correlated significantly (r²=0.676. P=0.0001) with peripheral eosinophil counts, but only weakly with asthma severity (r,=0.21, P=0.046). Serum ECP was significantly higher in atopic children (25±11 μg/l) than in nonatopic children (16±15 μg/l) iP=0.01). Bronchial hyperresponsiveness had no significant correlation (r_s=-0.21, P=0.30) with serum ECP Lung function test results had no (peak flow) or only a weak (FEV) correlation with serum ECP. In distinguishing between children with and without asthma or in assessing asthma severity, serum ECP is not superior to the peripheral blood eosinophil count. The diagnostic sensitivity and specificity of ECP in serum for detecting symptomatically active asthma, evaluated against the cutoff level of ECP in serum of 16 mg/1, were 54% and 71%, respectively.     

Significance of the eosinophil cationic protein/eosinophil count ratio in asthmatic patients: its relationship to disease severity.

BACKGROUND: Serum levels of eosinophil cationic protein (ECP) may reflect the degree of bronchial inflammation in patients with asthma, but its clinical value as a parameter for monitoring asthma remains controversial. OBJECTIVE: We measured the ratios of the serum ECP concentrations to peripheral blood eosinophil counts (ECP/Eo ratio) in patients with asthma and evaluated the correlation between these ratios and individual asthma severity. METHODS: The serum ECP concentrations and peripheral blood eosinophil counts were measured by radioimmunoassay and an autoanalyzer, respectively. Each patient with asthma was in remission at the time the serum specimen was obtained. An overall evaluation of asthma severity for each patient was determined by the frequency and severity of asthma attacks and by clinical scores. RESULTS: The ECP/Eo ratio in patients with severe asthma was significantly higher than in those with mild asthma. However, serum ECP concentrations and peripheral blood eosinophil counts were not different among the patients with mild, moderate, or severe asthma. The ECP/Eo ratios correlated significantly with the monthly average of the clinical scores, but the serum ECP concentrations did not correlate with the monthly average of the clinical scores. The ECP/Eo ratios were also increased in patients with more severe asthma whose serum IgE concentrations and peripheral eosinophil counts were not elevated. CONCLUSIONS: The ECP/Eo ratio may be useful in assessing asthma severity; however, the serum ECP concentration or peripheral blood eosinophil count is not useful.     

Bronchial responsiveness to methacholine and adenosine 5'-monophosphate in young children with asthma: their relationship with blood eosinophils and serum eosinophil cationic protein

BACKGROUND: Bronchial hyperresponsiveness is a characteristic feature of asthma, and is usually measured by bronchial challenges using direct or indirect stimuli. Blood eosinophil numbers and serum levels of eosinophil cationic protein (ECP) are considered as indirect measures of airway inflammation in asthma. The aim of this study was to investigate whether bronchial responsiveness to adenosine 5'-monophosphate (AMP) is more closely associated with blood eosinophil markers, compared with that to methacholine, in young children with asthma. METHODS: Methacholine and AMP bronchial challenges were performed in 4- to 6-year-old children with asthma (n = 77) and in healthy controls (n = 32), using a modified auscultation method. The end-point was defined as the appearance of wheezing and/or oxygen desaturation. The peripheral blood eosinophil counts and serum ECP concentrations were determined in each subject. RESULTS: A positive response to methacholine (end-point concentration < or =8mg/ml) and to AMP (end-point concentration < or =200 mg/ml) was observed in 74 (96.1%) and 66 asthmatic children (85.7%), respectively. A majority of controls was unresponsive to both challenges. In the asthma group, there was no significant correlation between methacholine end-point concentration and the eosinophil counts (r = -0.111, P = 0.337) or serum ECP levels (r = -0.126, P = 0.274). In contrast, AMP end-point concentration correlated significantly with the eosinophil counts (r = -0.372, P = 0.001) and with serum ECP levels (r = -0.371, P = 0.001). CONCLUSIONS: Our results suggest that bronchial responsiveness to AMP is more closely related to airway inflammation, compared with that to methacholine, and support the potential usefulness of AMP challenges in detecting inflammatory changes in young children with asthma.     

Eosinophilic airway inflammation in nasal polyposis.

BACKGROUND: Asthma and asymptomatic bronchial hyperresponsiveness (BHR) are frequent findings in patients with nasal polyposis (NP). OBJECTIVE: To elucidate mechanisms responsible for the development of BHR, we initiated a prospective study of bronchial inflammation as assessed by bronchial lavage (BL) and bronchial biopsy specimens in 35 patients with noninfectious NP. METHODS: BHR was determined with methacholine provocation testing. Differential cell count, ECP, and histamine and tryptase levels were determined in BLs. Pathologic examination of bronchial biopsy specimens was performed with May-Grünwald-Giemsa stain to assess the number of lymphocytes. Indirect immunoenzymatic methods were used to identify eosinophils and mast cells. RESULTS: Fourteen patients did not exhibit BHR (group A); 7 patients had asymptomatic BHR (group B); and 14 patients had BHR associated with asthma (group C). Patients of group C tended to have a longer duration of nasal symptoms than those of groups A and B. FEV1 (L) was significantly lower in group C than in groups A and B. The number and percentage of eosinophils were significantly higher in BLs in groups B and C than in group A (P <. 05). Patients of groups B and C had a significantly higher number of eosinophils in bronchial submucosa (14.0 +/- 1.5/mm2 and 19.0 +/- 1. 9/mm2, respectively) than patients of group A (0.1 +/- 0.1/mm2). The number of lymphocytes was also higher in groups B and C than in group A. FEV1 (percent of predicted value) and eosinophil number within bronchial mucosa correlated negatively. CONCLUSION: Our results demonstrate that patients with NP and asymptomatic BHR had an eosinophilic bronchial inflammation similar to that observed in asthmatic patients with NP, whereas patients with NP without BHR do not feature eosinophilic lower airways inflammation. The clinical relevance of these results requires careful follow-up to determine whether eosinophilic inflammation in these patients precedes and is responsible for the development of obvious asthma.     

A randomized, double-blind trial of the effect of treatment with montelukast on bronchial hyperresponsiveness and serum eosinophilic cationic protein (ECP), soluble interleukin 2 receptor (sIL-2R), IL-4, and soluble intercellular adhesion molecule 1 (sICAM-1) in children with asthma

BACKGROUND: Anti-inflammatory properties of leukotriene modifiers and their effect on bronchial hyperresponsiveness have not been studied in children with asthma. OBJECTIVE: The primary objective of this study was to determine the changes in serum levels of inflammatory mediators, clinical efficacy, and bronchial hyperresponsiveness after treatment with montelukast. METHODS: In this double-blind, randomized, placebo-controlled trial, 39 children with mild-to-moderate atopic asthma were randomly allocated to receive montelukast or placebo for 6 weeks. Main outcome measures were changes in serum concentrations of soluble interleukin 2 receptor (sIL-2R), IL-4, and soluble intercellular adhesion molecule 1 (sICAM-1); peripheral blood eosinophil count; and eosinophilic cationic protein (ECP). Asthma severity score, FEV(1), and bronchial hyperreactivity (BHR) for histamine were secondary end points. RESULTS: Compared to placebo, serum concentrations of IL-4, sICAM-1, and ECP and eosinophil blood counts significantly decreased after 6 weeks of treatment with montelukast. Montelukast significantly improved asthma control and FEV(1). Montelukast resulted in within-group significant decrease in levels of serum sIL-2R (611 vs. 483 pg/mL), IL-4 (0.123 vs 0.102 pg/mL), sICAM-1 (280 vs. 244 ng/mL), and ECP (74 vs. 59 microg/mL) and in eosinophil blood counts (349 vs. 310 cells/mm(3)). Mean FEV(1) value changed from 85% of predicted to 95% (P <.001) and for histamine (PC(20)H) from 2.8 mg/mL to 3.8 mg/mL (P <.001) after treatment with montelukast. There was no significant difference between montelukast and placebo recipients in the serum concentrations of sIL-2R and PC(20)H after treatment. CONCLUSION: Montelukast provides clinical benefit to patients with chronic asthma and decreases bronchial hyperresponsiveness. Montelukast caused a statistically significant decrease of serum concentrations in cytokine, ICAM-1, and ECP and peripheral blood eosinophil counts over the 6-week treatment period. This observation raises the possibility that leukotriene receptor antagonists, such as montelukast, may have effects on parameters of asthmatic inflammation.     

Nitric oxide metabolites,eosinophils, and eosinophilic cationic protein in patients with asthma: sputum versus blood

The monitoring of airway inflammation has assessed in bronchial asthma directly by sputum examination, and indirectly by measurements in peripheral blood. To investigate the diagnostic value of these two methods, we compared nitric oxide (NO) metabolites, eosinophils, and eosinophil cationic protein (ECP) in sputum and blood in patients with asthma and control subjects. Sputum and serum were obtained from fifteen patients with asthma, and then were examined before anti-asthma treatment, including steroid preparations. ECP was measured by fluoroimmunoassay. NO metabolites were assayed by using modified Griess reaction. Asthmatic patients, compared with control subjects, had significantly higher level of NO metabolites, higher proportion of eosinophils, and higher levels of ECP in sputum. Asthmatic patients, compared with control subjects, however, had significantly higher number of eosinophils, and were at higher levels of ECP in blood. FEV1, FEV1/FVC was negatively correlated with sputum eosinophils. The area under receiver operating characteristic (ROC) curve showed that eosinophils in sputum are significantly accurate markers than NO metabolites in sputum and blood. These findings suggest that the proportion of eosinophils in sputum have more accurate diagnostic marker of asthmatic airway inflammation than NO metabolites in sputum in differentiating asthmatic patients from control subjects.     

Evaluation of serum eosinophil cationic protein as a predictive marker for asthma exacerbation in patients with persistent disease

BACKGROUND: Eosinophilic inflammation is a feature of asthma. However, serological markers to indicate eosinophil activation in this process are not fully defined. OBJECTIVE: To evaluate the relationship of serum eosinophil cationic protein (ECP) to asthma worsening and a marker for treatment effectiveness, 26 adult patients with an asthma exacerbation were identified. METHODS: Identified asthma subjects were treated with oral corticosteroids (prednisone) for 14 days. The lung function variables, forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF), were determined as percentage of predicted and the blood total eosinophil count and serum ECP levels were measured. Patients were re-evaluated after 14 days of corticosteroid treatment and then every 3 months thereafter during a 12-month period. RESULTS: Eighteen patients responded to prednisone treatment, whereas eight did not, assessed as improvement of their lung function parameters. Different serum ECP patterns could be seen in the responders compared with the non-responders. All 18 responders had considerably increased serum ECP at the time of exacerbation, whereas the non-responders had lower serum ECP levels. The serum ECP levels decreased to a greater extent in the responder patient group than in the non-responder patients following prednisone treatment. This difference in patterns was not seen with total blood eosinophil counts. CONCLUSION: Our findings suggest that serum ECP may be used to predict a response to corticosteroid therapy in adult patients with asthma.     

Bronchial hyperresponsiveness in two populations of Australian schoolchildren. I. Relation to respiratory symptoms and diagnosed asthma

In order to explore the relationship between bronchial hyperresponsiveness (BHR) to inhaled histamine, respiratory symptoms and diagnosed asthma in children, we undertook a cross-sectional study of 2363 Australian schoolchildren aged 8–11 years. The methods used included a self-administered questionnaire to parents, which was shown to have a high degree of repeatability, and a histamine inhalation test to measure bronchial responsiveness (BR). The study showed that 17.9% of children had BHR, defined as a 20% fall in FEV₁ at a provoking dose of histamine (PD₂₀ FEV₁) of less than 7.8 μmol. The distribution of PD₂₀ FEV₁ appeared to be continuous. Most children with PD₂₀ FEV₁ values < 1.0μmol had symptoms of asthma. However, 6.7% of children had BHR without symptoms or a previous diagnosis of asthma and 5.6% had had a diagnosis of asthma but had no BHR. Although there was a good association between BHR and respiratory symptoms, questionnaire data of wheeze and diagnosed asthma do not reflect accurately the level of BHR in the community. We conclude that cross-sectional studies of BR to identify children with BHR probably do not reflect the prevalence of asthma in populations of children. However, the strong association between BHR and symptoms, particularly in children with severe and moderate BHR, suggests that measurements of BR in populations are useful for defining a group of children whose airways behave differently from those of the majority. Prospective studies are needed to define the level of BHR that is associated with important sequelae.