Apoptotic eosinophils in sputum from asthmatic patients correlate negatively with levels of IL-5 and eotaxin

BACKGROUND: Eosinophilic inflammation of the airways is a key characteristic of asthma. A defect in eosinophil apoptosis might contribute to the chronic tissue eosinophilia associated with asthma. OBJECTIVE: Our purpose was to examine whether the occurrence of apoptotic eosinophils in induced sputum from asthmatic patients correlate with interleukin (IL)-5 and eotaxin. METHODS: Thirty stable and 30 exacerbated asthmatic patients were recruited. Twenty healthy subjects were enrolled as a control group. Induced sputum was obtained from asthmatic patients and from control subjects. The number of apoptotic eosinophils in sputum was assessed by flow cytometry. In sputum supernatant, eosinophil cationic protein (ECP) was measured by sensitive radioimmunoassay, and IL-5 and eotaxin by sandwich enzyme linked immunosorbant assay. RESULTS: Levels of eosinophils, apoptotic eosinophils, IL-5, ECP and eotaxin from asthmatic patients were higher than those from healthy subjects. Thirty exacerbated asthmatics showed higher proportions of eosinophils (median 29.3%, range 13.4%-40.9%), more detectable levels of IL-5 (50.44, 32.99-67.01 pg/ml) and eotaxin (644.6, 197.4-937.7 pg/ml) in their sputum than the patients with stable asthma (P<0.05). There were significant inverse correlations between the levels of sputum IL-5 and the proportion of sputum eosinophil apoptosis in patients with exacerbated and stable asthma (r=-0.85 and -0.79, P<0.01 and P<0.05, respectively). Also inverse correlations were found between the levels of eotaxin and the proportion of sputum eosinophil apoptosis in exacerbated (r=-0.85, P<0.01), or stable asthma (r=-0.69, P<0.05). Additional positive correlations between the levels of sputum IL-5 and eotaxin in either exacerbatated (r=0.93, P<0.01) or stable asthma (r=0.82, P<0.05) were observed. CONCLUSIONS: Apoptosis of eosinophils might be suppressed by proinflammatory cytokines and chemokines such as IL-5 and eotaxin leading to their accumulation in the lung. Stimulation of eosinophils in airway with IL-5 and eotaxin may play a crucial role in allergic inflammation.     

Interleukin-10 level in sputum is reduced in bronchial asthma, COPD and in smokers.

Interleukin (IL)-10 is a potent regulatory cytokine that decreases inflammatory responses. This study investigated whether IL-10 levels in the airway are decreased in chronic airway inflammation associated with asthma or chronic obstructive pulmonary disease (COPD). Sputum was obtained from 12 healthy nonsmokers, 10 healthy smokers, 16 asthmatic patients and seven patients with COPD by means of the sputum-induction method. The IL-10 level was measured via enzyme-linked immunosorbent assay and immunocytochemical analysis. The IL-10 level in sputum was significantly lower in asthma and COPD patients and healthy smokers compared with that in healthy nonsmokers (nonsmokers, 68.0+/-11.3; smokers, 45.3+/-7.8; asthma, 26.7+/-4.0; COPD, 18.0+/-2.3 pg x mL(-1); p<0.05 for nonsmokers versus the other groups). The percentage of IL-10-positive cells in the sputum was also significantly lower in asthma and COPD and in smokers (nonsmokers, 13.2+/-1.7; smokers, 6.4+/-1.8; asthma, 5.4+/-3.5; COPD, 3.5+/-1.6%; p<0.05 for nonsmokers versus the other groups). The IL-10-positive cell appeared morphologically to be the macrophage. These data suggest that the reduced level of interleukin-10 within the airways plays a role in the pathogenesis of chronic airway inflammation in asthma and chronic obstructive pulmonary disease.     

IL-2 and IL-10 levels in induced sputum and serum samples of asthmatics.

BACKGROUND: There is consisting evidence that asthma is associated with airway inflammation. Originally IL-10 and IL-2 were described as lymphokines produced by T cells in mediating cellular infiltration into the airways and continue to be of interest in evaluating asthma pathogenesis. The aim of this study was to evaluate the serum and sputum levels of IL-2 and IL-10 in asthmatic subjects and healthy controls and to correlate disease activity and other clinical indices with concentrations of IL-2 and IL-10 in serum and sputum samples. METHODS: We evaluated cell profiles and IL-2 and IL-10 levels in induced sputum samples and in serum samples of 6 mild, 5 moderate, 7 severe asthmatic patients and 5 healthy controls by using ELISA. RESULTS: The mean IL-2 in sputum samples of asthmatics and controls were 35.3 +/- 13.2 pg/ml and 35.3 +/- 8.4 pg/ml, respectively. The mean IL-2 in serum samples of asthmatics and controls were 42.7 +/- 21.1 pg/ml and 30.3 +/- 2.4 pg/ml, respectively. Both levels did not result in any statistically significant difference between asthmatics and controls. There was no correlation between serum and sputum IL-2 levels, however sputum IL-2 levels correlated with percentage of sputum lymphocytes (p < 0.03, r = 0.51). The mean IL-10 levels in sputum samples of asthmatics and controls were 4.4 +/- 3.3 pg/ml and 3.9 +/- 5.9 pg/ml, respectively, the mean IL-10 level in serum of asthmatics and controls were 4.1 +/- 3.8 pg/ml and 2.3 +/- 2.5 pg/ml, respectively. We could not find statistically significant difference of serum or sputum IL-10 levels between asthmatics and controls. There was only correlation between serum and sputum IL-10 levels in asthmatics (p < 0.0008, r = 0.73). There was no difference between asthmatic subgroups regarding sputum and serum levels of IL-2 and IL-10. No correlation could be demonstrated between sputum or serum IL-2 and IL-10 levels and clinical severity. CONCLUSIONS: We have demonstrated the presence of detectable concentrations of the IL-2 and IL-10 in serums and induced sputum samples of asthmatics, however, they have no predictive value for asthma since their levels are not increased in asthmatic patients over controls. Moreover, IL-2 level positively correlated with lymphocyte percentage in induced sputum. The results suggest that measurement of IL-2 and IL-10 concentrations in serum and sputum will not be of diagnostic use in asthma and a reflection of the severity of asthmatic airway inflammation.     

Smoking Affects Eotaxin Levels in Asthma Patients

Background. Chronic airway inflammation is most important pathological finding in asthma. Cigarette smoking may modify type of inflammation as well as may influence disease severity and response to the treatment. Objective. Thus the aim of this study was to investigate whether cigarette smoking may have an influence on the levels of eotaxin-1, eotaxin-2, eotaxin-3 and IL-5 in patients with stable mild/moderate asthma. Methods. 45 steroid naive asthmatics (mean age: 55.2 ± 2.2 yrs) and 23 “healthy” smokers and non-smokers control subjects (mean age: 54.4 ± 9.7 yrs) were investigated. Asthmatics were divided into two subgroups according to their smoking histories: asthmatic smokers (n = 19) who currently smoke and have a history of > 10 pack-years and asthmatic never-smokers (n = 26). BAL and induced sputum were performed. Cytospins of induced sputum and BAL were stained with May-Grünwald-Giemsa for differential cell counts. Eotaxin-1, eotaxin-2, eotaxin-3 and IL-5 concentrations in serum, sputum and BAL supernatant was measured using a commercial ELISA kit. Results. In sputum supernatant from asthma smokers was significantly higher concentration of eotaxin-1 than in non-smokers asthmatics (203.4 ± 10.0 vs. 140.2 ± 9.5 respectively, p < 0.05). In non-smokers asthma patients levels of BAL eotaxin-1 strongly related to percent and absolute numbers of BAL eosinophils and neutrophils (Rs = 0.737 and Rs = 0.514 respectively, p < 0.05). The number and percent of sputum neutrophils and eosinophils, obtained from smokers asthmatics, significantly correlated with eotaxin-2 concentration in sputum supernatant (Rs = 0.58 and Rs = 0.75 respectively, p < 0.05). IL-5 levels in the serum and sputum from asthmatic never-smokers were significantly higher than they were from asthmatic smokers and “healthy” smokers. Asthmatic never-smokers showed a significantly higher amount of IL-5 in serum and sputum than the asthmatic smokers showed. Conclusions. This study showed the elevated levels of sputum eotaxin-1 as well as serum, sputum and BAL eotaxin-2 in asthmatic smokers without a significant increase of eosinophils compared to asthmatic never-smokers. The eotaxin concentrations were related not only with number of eosinophils but also with the number of neutrophils in all the studied tissue compartments. The data herein permits a suggestion that smoking may influence change in asthmatic airway inflammation by stimulating the production of eotaxins.     

Reduced bronchial CD4+ T-cell density in smokers with occupational asthma.

Cigarette smoking may alter bronchial inflammation in asthma. Multicolour immunohistofluorescent examination on bronchial cryosections was used to examine bronchial inflammatory cell infiltrate in patients with occupational asthma. Monoclonal antibodies to CD3, CD4, CD8, T-cell receptor-delta1, CD68 and human leukocyte antigen-DR were combined to identify T-cell subsets and macrophages in bronchial biopsies from 20 workers with occupational asthma (12 smokers and eight nonsmokers), 15 healthy workers (seven smokers and eight nonsmokers) and 10 nonsmoking, nonexposed controls. The increased subepithelial CD4+ T-cell density in nonsmoking asthmatics was not present in smoking asthmatics, who had the lowest CD4+ T-cell density of all groups. The decreased subepithelial CD4+ and CD8+ T-cell density correlated with a reduction in lung function, as measured by percentage predicted forced expiratory volume in one second, in smoking asthmatics only. Although smoking asthmatics had a significantly increased number of intraepithelial CD8+ T-cells and macrophages compared with nonsmoking asthmatics, the proportion of gammadelta-T-cells was significantly decreased in both asthmatic groups. Smoking asthmatics had a distinctly different distribution of T-cell subsets compared with nonsmoking asthmatics. The accumulation of subepithelial CD4+ T-cells, which was observed in nonsmoking asthmatics, appeared to be inhibited in smoking asthmatics, suggesting a smoking-induced bronchial immune modulation, at least in occupational asthma in the aluminium industry.     

Prostaglandin E2 in the expired breath condensate of patients with asthma.

Inhaled prostaglandin (PG)E2 has been found to cause bronchodilation in asthmatics, although it does not have bronchodilative effects in normal subjects. The aim of this study was to investigate the levels of PGE2 in the expired breath condensate of patients with asthma, the possible contribution of smoking habit to its levels and the possible relationship between PGE2 and the degree of bronchial hyperresponsiveness, as assessed by the provocation dose of histamine causing a 20% fall in forced expiratory volume in one second (FEV1) (PD20). A total of 30 mild asthmatics (15 smokers, all steroid-naive, FEV1 88+/-6 (%+/-SD)) and 20 healthy control subjects (10 smokers) were studied. Histamine challenge testing was performed in all subjects and the PD20 was determined. The results showed that asthmatic smokers had significantly higher values of PGE2 compared to asthmatic nonsmokers and control subjects (40+/-21 versus 14.5+/-4.5 versus 11.7+/-3 pg x mL(-1), respectively). Further analysis showed that PGE2 levels were significantly higher in asthmatic smokers compared to smoker and nonsmoker controls (40+/-21 versus 11.6+/-2 versus 11.7+/-4 pg x mL(-1), respectively). No significant difference was observed between asthmatic nonsmokers and both control smokers and control nonsmokers. No significant correlation was found between PGE2 levels and PD20 in all groups of asthmatics, irrespective of smoking habit. In conclusion, the elevation of prostaglandin E2 in the expired breath condensate of patients with asthma is mainly attributed to smoking habit and prostaglandin E2 levels do not predict the degree of bronchial hyperresponsiveness.     

The Effect of Cigarette Smoking on the Levels of Nitric Oxide Metabolites in the Sputum of Patients with Acute Asthma

Cigarette smoking may reduce the production of endogenous nitric oxide (NO), which plays an important role in inflammation of the asthmatic airway. NO metabolites in sputum were measured in 11 cigarette smokers and five nonsmokers, all with acute asthma. NO metabolite levels reflected the severity of asthmatic exacerbation, as they were significantly higher in patients with “severe,” or “respiratory arrest imminent” asthma than in patients with “mild” to “moderate” asthma. There were no significant differences in sputum NO metabolite levels between smokers and nonsmokers with asthma, nor were any differences observed in NO metabolite levels for relative cigarette pack-years in smokers. These findings suggest that severe airway inflammation outweighs the effect of smoking on NO in the sputum of patients with asthma.     

The effect of cigarette smoking on exhaled nitric oxide in mild steroid-naive asthmatics.

STUDY OBJECTIVES: It has been demonstrated previously that exhaled nitric oxide (eNO) is increased in steroid-naive asthmatics and that inhaled steroids reduce eNO in these patients. Cigarette smoking has also been reported to reduce the eNO in healthy volunteers. Recently a correlation has been demonstrated between eNO and airway hyperresponsiveness in steroid-naive, mild asthmatics. We hypothesized that cigarette smoking would reduce the eNO level in steroid-naive asthmatics and might, therefore, affect the correlation between eNO and airway hyperresponsiveness. DESIGN: Comparison of eNO in healthy smoking and nonsmoking volunteers with the level of eNO in steroid-naive and steroid-treated asthmatics. Correlate the eNO level with the provocative concentration of histamine causing a 20% fall in FEV1 (PC20hist) in the asthmatic smoking and nonsmoking patients. SETTING: University outpatient asthma clinic. PATIENTS AND METHODS: eNO levels and PC20hist were measured in three different asthmatic patient groups (group A = 29 steroid-naive, nonsmoking asthmatics; group B = 19 steroid-treated, nonsmoking asthmatics; and group C = 13 smoking, steroid-naive asthmatics) and in two healthy volunteer groups (group D = 18 nonsmoking; and group E = 16 smoking). RESULTS: eNO in group A was significantly increased compared with the values in groups B and D (21.8+/-12.7, 12.8+/-4.9, and 10.6+/-2.2 parts per billion [ppb], respectively). Cigarette smoking decreased eNO in healthy volunteers (7.4+/-1.8 ppb, group E) as well as in steroid-naive asthmatics (12.7+/-5.1 ppb, group C). There was a significant correlation between eNO and PC20hist in group A (r = -0.45, p < 0.05); this correlation was, however, lost in both groups B and C. CONCLUSION: Cigarette smoking and inhaled steroids reduce the eNO in patients with mild asthma to a comparable extent. Because the correlation between eNO and airway hyperresponsiveness was lost in steroid-treated and smoking, steroid-naive asthmatics, we question the value of eNO as a marker of airway inflammation, at least in mild asthmatics who are already being treated with inhaled steroids or who are currently smoking.     

Leukotriene E(4) in urine in patients with asthma and COPD--the effect of smoking habit

Leukotriene E(4) (LTE(4)) is implicated in asthma pathophysiology and possibly in chronic obstructive pulmonary disease (COPD) as one of the causes of persistent bronchoconstriction and mucus hypersecretion. Cigarette smoking stimulates cysteinyl leukotrienes (CysLTs) production. We investigated whether LTE(4) is equally increased in asthma and COPD and whether smoking significantly affects LTE(4) levels. Secondary outcomes involved correlations with inflammatory and functional parameters. We studied 40 patients with COPD [20 smokers], 40 asthmatics [20 smokers] and 30 healthy subjects [15 smokers]. Spirometry (FEV(1)% pred., FEV(1)/FVC) was performed, urine was collected for measurement of LTE(4) and creatinine, induced sputum was collected for differential cell counts and serum for ECP. LTE(4)/creatinine levels (pg/mg) [mean (sd)] were increased in asthmatic patients compared to COPD and controls, [125.6(54.5) vs. 54.5(19) vs. 55.9(18.9)pg/mg, respectively, P<0.0001 for asthma]. Smoking significantly affects LTE(4) levels only in asthmatic patients [164 (48) vs. 87 (26.3), P<0.0001 for smokers]. The only significant correlation was between eosinophils in induced sputum and LTE(4)/creatinine levels in asthmatics. In conclusion, patients with asthma presented higher LTE(4) values compared to normals and patients with COPD. Smoking significantly affects LTE(4) values only in asthmatics indicating a different underlying CysLTs inflammatory process in this condition.     

Reduced interleukin-18 levels in BAL specimens from patients with asthma compared to patients with sarcoidosis and healthy control subjects

STUDY OBJECTIVES: To investigate whether differing airway interleukin (IL)-18 levels may be implicated in the pathogenesis of asthma and sarcoidosis. SETTING: University teaching hospital. Patients and methods: IL-18 levels were measured in BAL fluid and in the supernatant of lipopolysaccharide (LPS)-stimulated alveolar macrophages obtained by BAL from 15 patients with sarcoidosis, 11 patients with asthma, and 13 healthy subjects. We also examined the relationship between IL-18 levels and macrophage and lymphocyte concentrations in BAL fluid. IL-18 was measured using an in-house enzyme-linked immunosorbent assay. RESULTS: IL-18 levels were significantly lower in BAL fluid from patients with asthma (median, 0.0 pg/mL; interquartile range, 0.0 to 0.0 pg/mL) compared to patients with sarcoidosis (median, 222.0 pg/10(6); interquartile range, 110 to 340 pg/mL; p = 0.009, Mann Whitney rank-sum test) and healthy control subjects (median, 162 pg/mL; interquartile range, 38 to 203 pg/mL; p = 0.025, Mann Whitney rank-sum test). Individual analyses comparing IL-18 levels with BAL macrophage counts, and IL-18 with lymphocyte counts in the three groups showed no correlation between these indexes. The mean levels of IL-18 in unstimulated macrophage supernatants were 410 pg/10(6) cells for patients with asthma, 723.4 pg/10(6) cells for patients with sarcoidosis, and 734.8 pg/10(6) cells for healthy control subjects (p > 0.05). Stimulated macrophages from patients with sarcoidosis responded with increasing amounts of IL-18 at lower doses of LPS than macrophages from healthy control subjects or patients with asthma. CONCLUSION: Our findings suggest that inherently low levels of IL-18 may be associated with the pathogenesis of asthmatic airway inflammation.     

Heterogeneity of airway inflammation in persistent asthma : evidence of neutrophilic inflammation and increased sputum interleukin-8

STUDY OBJECTIVES: To identify the characteristics of airway inflammation in persistent asthma and to examine the role of neutrophilic inflammation in noneosinophilic persistent asthma. METHODS: Nonsmoking adults (n = 56) with persistent asthma and healthy control subjects (n = 8) underwent hypertonic saline solution challenge and sputum induction. Selected sputum portions were dispersed with dithiothreitol and assayed for total cell count, cellular differential, supernatant eosinophil cationic protein (ECP), myeloperoxidase, and interleukin (IL)-8. RESULTS: We identified two distinct inflammatory patterns. Typical eosinophilic inflammation occurred in 41% of subjects, whereas the remainder exhibited noneosinophilic asthma (59%). Both neutrophil percentage and absolute neutrophil counts were increased in subjects with noneosinophilic asthma (64%, 283 x 10(6)/mL) compared to eosinophilic asthma (14%, 41 x 10(6)/mL) and control subjects (34%, 49 x 10(6)/mL; p = 0.0001). Myeloperoxidase was elevated in both noneosinophilic (280 ng/mL) and eosinophilic groups (254 ng/mL) compared with control subjects (82 ng/mL; p = 0.002). Sputum IL-8 levels were highest in subjects with noneosinophilic asthma (45 ng/mL) compared to eosinophilic asthma (9.6 ng/mL) and control subjects (3.5 ng/mL; p = 0.0001). Neutrophils correlated with IL-8 levels (r = 0.72). ECP was highest in subjects with eosinophilic asthma (2,685 ng/mL) compared with noneosinophilic asthma (1,081 ng/mL) and control subjects (110 ng/mL; p = 0.0001). CONCLUSION: Induced-sputum analysis in persistent asthma identifies two different inflammatory patterns. The most common pattern is noneosinophilic, associated with a neutrophil influx and activation, which may be mediated by IL-8 secretion. There is heterogeneity of airway inflammation in persistent asthma, which indicates differing mechanisms and may impact on treatment responses.     

NO in exhaled air is correlated with markers of eosinophilic airway inflammation in corticosteroid-dependent childhood asthma.

The relationship between nitric oxide in exhaled air, levels of sputum eosinophils, sputum eosinophil cationic protein (ECP) and urinary eosinophil protein X (EPX) excretion has not yet been investigated in corticosteroid-dependent childhood asthma. Therefore, taking 25 children with stable asthma (mean age 11.2 yrs) treated with inhaled corticosteroids and nine nonatopic healthy control children (mean age 12.8 yrs) the level of exhaled NO was measured by means of a chemiluminescence analyser before and after sputum induction. This was conducted as a slow vital capacity manoeuvre under standardized conditions with a target flow of 70 mL x s(-1) against a resistance of 100 cm H2O x L(-1) x s. Sputum induction was performed by inhalation of hypertonic saline (3, 4, and 5%) in a standardized manner and a single sample of urine was collected. Exhaled NO (p = 0.01), absolute eosinophil cell counts in sputum (p = 0.02), sputum ECP (p = 0.09) and urinary EPX excretion (p = 0.02) were higher in asthmatics compared to control children. Exhaled NO was positively correlated with sputum ECP (r(s) = 0.59, p = 0.002), urinary EPX (r(s) = 0.42, p = 0.03), and sputum eosinophils (r(s) = 0.30, p = 0.15) in the asthmatic children. These correlations appeared to be pronounced after sputum induction, where NO values had decreased (p = 0.01). None of the correlations were observed in the group of nonatopic control subjects. Additionally there were significant correlations between sputum ECP and sputum eosinophils (r(s) = 0.69, p<0.001) as well as between sputum ECP and urinary EPX excretion (r(s) = 0.58, p = 0.003) in the asthmatics. Exhaled NO provides information about the degree of eosinophilic airway inflammation and thus appears to be a useful and easy-to-perform inflammatory marker in corticosteroid-dependent asthma.     

哮喘患者痰液中炎症介质和细胞因子与气道重塑的关系研究

目的　以支气管粘膜网状基底膜厚度作为气道重塑的指标 ,探讨哮喘患者气道重塑与痰液中细胞因子和炎症介质的关系。方法　对 2 0例哮喘患者和 10名正常对照者经纤维支气管镜行(纤支镜 )支气管粘膜活检 ,测量支气管粘膜网状基底膜厚度 ,用荧光酶联免疫方法测定痰液中的嗜酸细胞阳离子蛋白 (ECP) ,酶联免疫法测定白细胞介素 5 (IL 5 )、肿瘤坏死因子 (TNF α)的水平 ;采用SPSS8 0统计软件作等级相关分析 ,探讨哮喘患者痰液中ECP、IL 5、TNF α水平与支气管粘膜厚度的关系。结果　缓解期哮喘患者支气管粘膜网状基底膜厚度为 (10 1± 2 6 ) μm ,与正常对照组 [(4 4± 1 2 )μm]比较 ,差异有显著性 (P <0 0 0 5 ) ;哮喘组痰液中ECP水平为 (14 4± 80 ) μg/L、IL 5为 (17± 4 ) μg/L、TNF α为 (14 6± 79) μg/L ,与正常对照组 [(81± 4 4 ) μg/L、(14± 4 ) μg/L、(5 3± 36 ) μg/L]比较 ,差异有显著性 (P <0 0 0 5 ) ;两组痰液中ECP、IL 5与支气管粘膜厚度呈明显正相关 (r =0 5 6 9、0 4 6 6 ,P均 <0 0 0 5 ) ;两组痰液中TNF α水平与粘膜厚度无明显相关 (r=0 2 5 4 ,P >0 0 5 )。结论　缓解期哮喘患者支气管粘膜网状基底膜厚度均存在不同程度增厚 ;而痰液ECP和IL 5水平与支气管粘膜厚度呈     

Interleukin-17 in sputum correlates with airway hyperresponsiveness to methacholine

BACKGROUND: Interleukin-17 (IL-17) is a novel cytokine secreted by activated human memory CD4+ T cells. In vivo IL-17 recruits neutrophils into the airways via the release of CXC chemokines (interleukin-8) from bronchial epithelial cells. Since neutrophils are implicated in pathogenesis of chronic obstructive pulmonary disease (COPD) chronic bronchitis (CB) and asthma, we hypothesized that there would be increased concentration of IL-17 in the airways of these patients. To test this hypothesis, we measured levels of IL-17 in induced sputum of COPD patients, chronic bronchitis and asthmatics and compared them with healthy controls. METHODS: Levels of IL-17 in induced sputum were measured via ELISA method in 19 COPD, 16 CB, 10 asthma and 11 control subjects. Airway responsiveness to methacholine was performed in people with FEV1 higher than 70% of predicted. RESULTS: There were no significant differences in IL-17 levels between control group and the other groups. However, levels of IL-17 in sputum of COPD patients were significantly lower than in asthma (P=0.004) and in CB (P=0.01) groups. Medians and (ranges) were as follows: asthma--37.6 pg/ml (18.8-55.7 pg/ml), CB 293 pg/ml (18.8-49.7 pg/ml) and COPD 24.6 pg/ml (0-34.1 pg/ml). Comparison of healthy control subjects (PC20 > 8 mg/ml) to a group with bronchial hyperreactivity, which consisted of asthmatics and CB patients, whose PC20 was less than 8 mg/ml, revealed that levels of IL-17 were significantly increased in the second group (P=0.02). Also, levels of IL-17 were significantly increased (P=0.02) in the asthmatic patients with bronchial hyperreactivity compared to healthy subjects. Moreover levels of IL-17 in sputum of all studied subjects correlated negatively with PC20 (r=-0.51, P=0.002). CONCLUSIONS: According to our results IL-17 is probably not involved in pathogenesis of stable COPD, but it may play a role in people with airway hyperresponsiveness.     

Eotaxin level in induced sputum is increased in patients with bronchial asthma and in smokers

BACKGROUND: Airway eosinophilia is one of the hallmarks of asthma. Eotaxin may play an important role in eosinophil recruitment. OBJECTIVES: To examine the relationship between eotaxin levels in the sputum and eosinophilic inflammation. METHODS: The sputum was obtained from 11 non-smokers, 14 smokers and 13 asthmatic patients using a sputum induction method. Eotaxin and interleukin (IL)-5 levels in the sputum were determined by ELISA and immunocytochemical analysis. RESULTS: Asthmatic patients had eosinophilia and smokers showed neutrophilia in their sputum. The eotaxin level in the sputum was significantly higher in smokers (median 412.5, range 91.1-872.2 pg/ml) and asthmatic patients (351.0, 185.0-928.0 pg/ml) compared with non-smokers (123.2, 0-369.0 pg/ml; both p < 0.05). IL-5 was detected in the sputum of 1 non-smoker, none of the smokers and 4 asthmatic patients. The percentage of eotaxin-positive cells was higher in smokers and asthmatic patients than in non-smokers, but the percentage of IL-5-positive cells was significantly higher only in asthmatic patients (p < 0.05). CONCLUSIONS: These findings suggest that the elevated eotaxin level in the sputum does not always accompany the increase in eosinophils, and cooperation with another cytokine such as IL-5 may be required for the recruitment of eosinophils.     

Leukotriene B4 in exhaled breath condensate and sputum supernatant in patients with COPD and asthma

STUDY OBJECTIVES: Some patients with COPD present with significant reversibility of airflow limitation after receiving bronchodilation therapy. Leukotriene B(4) (LTB(4)) has been implicated in the pathophysiology of both COPD and asthma. We tested the hypothesis that COPD patients with airflow reversibility and asthmatic patients who smoke might have similar levels of LTB(4) in exhaled breath condensate (EBC) and sputum supernatant. The repeatability and stability of LTB(4) measurements were additionally studied. DESIGN: Prospective, cross-sectional study. PATIENTS OR PARTICIPANTS: We studied 30 patients with COPD (15 smokers [FEV(1), 56% predicted; SD, 6% predicted]; 15 patients with significant reversibility in airway obstruction after bronchodilation [FEV(1), 14% predicted; SD, 2% predicted]). Fifteen asthmatic patients who smoked, with similar FEV(1) and reversibility were also studied. Ten healthy smokers served as control subjects. SETTING: A hospital research laboratory. INTERVENTIONS: Spirometry and reversibility testing were performed on the first visit. On the following day, EBC was collected for the measurement of LTB(4), and induced sputum was collected for differential cell counts and LTB(4) measurement in the sputum supernatant. MEASUREMENTS AND RESULTS: LTB(4) levels in EBC [mean (SD)] were increased in COPD patients (mean, 86.7 pg/mL; SD, 19 pg/mL) and asthmatic patients (mean, 97.5 pg/mL; SD, 15 pg/mL) compared to control subjects (mean, 32.3 pg/mL; SD, 10 pg/mL; p < 0.0001 for both groups). COPD patients with airflow reversibility (mean, 99.8 pg/mL; SD, 12 pg/mL) had values similar to those of asthmatic patients (mean, 97.5 pg/mL; SD, 15 pg/mL; p = 0.2) and higher than those of COPD patients without airflow reversibility (mean, 73.7 pg/mL; SD, 17 pg/mL; p = 0.002). Similar results were observed in the sputum supernatant. Measurements of LTB(4) in EBC and sputum were repeatable on two consecutive days, but measurements in the frozen samples of EBC and sputum were not stable after 3 weeks. CONCLUSIONS: Patients with asthma and reversible COPD presented with higher LTB(4) values compared to patients with nonreversible COPD and healthy smokers. This difference may be mainly attributed to the presence of reversibility in airway obstruction, probably as part of a common underlying inflammatory process.     

Clinical assessment of asthma severity partially corresponds to sputum eosinophilic airway inflammation

In the aim to evaluate the relationship between sputum eosinophil percentages and eosinophil cationic protein (ECP) concentrations, as markers of airway inflammation, and different Levels of asthma severity, we examined 223 patients consecutively observed in our asthma clinic. Diagnosis of asthma was made according to internationally accepted criteria. Asthma severity was evaluated according to frequency of symptoms, FEV1, peak expiratory flow variability and level of asthma treatment needed to control asthma. Spontaneous or induced sputum was collected. Adequate sputum samples were obtained in 68 untreated subjects and in 117 subjects regularly treated with ICS. A control group of 14 normal subjects was also examined. In untreated subjects, mild intermittent asthmatics showed a lower sputum eosinophil percentage in comparison with other groups of asthma severity, while no difference in ECP levels was detected. In treated subjects, severe asthmatics showed higher levels of sputum eosinophils and ECP in comparison with other groups of asthma severity. Mild persistent and moderate persistent patients did not differ for sputum eosinophils or ECP in both untreated and treated subjects. Controls were significantly different from all groups of untreated and treated asthmatics. In conclusion, the assessment of asthma severity according to clinical and functional findings only partially corresponds to the severity of eosinophilic airway inflammation as assessed by induced sputum analysis.     

Interleukin-13 and interleukin-5 in induced sputum of eosinophilic bronchitis: comparison with asthma

STUDY OBJECTIVES: Experimental studies on asthma have indicated that interleukin (IL)-13 induces airway hyperreactivity (AHR). However, it remains unproven that IL-13 is responsible for AHR in asthmatic patients. Eosinophilic bronchitis (EB) shows normal airway responsiveness despite eosinophilic airway inflammation of severity similar to that of asthma. This study evaluated the role of IL-13 in asthma by comparing the sputum IL-5 and IL-13 levels in both groups. METHODS: Comparisons between asthma and EB would clarify the role of IL-13 in AHR. IL-5 and IL-13 were assayed in the sputum and culture supernatants of peripheral blood mononuclear cells (PBMCs) from 22 asthmatic patients, 12 EB patients, and 11 healthy control subjects. RESULTS: IL-13 levels were higher in the asthmatic patients than in the EB patients or healthy control subjects (p = 0.001). IL-5 levels were similar in the asthmatic patients and EB patients, who had significantly higher levels than those of healthy control subjects. Sputum IL-13, but not IL-5, is inversely correlated with the provocative concentration of a substance causing a 20% fall in FEV1 for methacholine in asthmatic patients (r = -0.502; p = 0.017). IL-13 production by PBMCs was significantly higher in asthmatic patients than in EB patients (p = 0.015), but the levels between EB patients and healthy control subjects was comparable. CONCLUSION: The results of the present study indicate that IL-13 is related to AHR in asthmatic patients.     

Effects of pranlukast administration on vascular endothelial growth factor levels in asthmatic patients

STUDY OBJECTIVES: We have previously found that vascular endothelial growth factor (VEGF) levels in induced sputum were increased in asthmatic patients, and that its levels were closely associated with the degree of airway obstruction and microvascular permeability. Therefore, this study was designed to examine the effects of pranlukast, a selective leukotriene receptor antagonist, on VEGF levels in induced sputum from steroid-untreated or steroid-treated asthmatic patients. DESIGN: Double-blind, randomized, placebo-controlled, crossover study. SETTING: University hospital. PARTICIPANTS: Twenty-three asthmatic patients (steroid-untreated, 13 patients; steroid-treated, 10 patients) and 10 healthy control subjects. INTERVENTIONS: All asthmatic patients received 4-weeks of therapy with pranlukast (225 mg bid), and sputum induction was performed before and after the 4-week treatment course. MEASUREMENTS AND RESULTS: In steroid-untreated asthmatic patients, the mean percentage of eosinophils (%EOS) and mean eosinophil cationic protein (ECP) levels in induced sputum were significantly decreased after 4 weeks of pranlukast administration (%EOS: before, 16.7% [SD, 7.1%]; after, 12.3% [SD, 4.0%]; p = 0.03; ECP levels: before, 774 ng/mL [SD, 258 ng/mL]; after, 564 ng/mL [SD, 204 ng/mL]; p = 0.034). Moreover, VEGF levels in the induced sputum and the airway vascular permeability index also were decreased after pranlukast administration (VEGF levels: before, 5,670 pg/mL [SD, 1,780 pg/mL]; after, 4,380 pg/mL [SD, 1,540 pg/mL]; p = 0.026; airway vascular permeability index: before, 0.032 [SD, 0.012]; after, 0.017 [SD, 0.006]; p = 0.01). In addition, the change in airway vascular permeability index from before to after pranlukast administration was significantly correlated with the change in VEGF levels (r = 0.782; p = 0.007). However, in steroid-treated asthmatic patients there was no significant difference in mean VEGF levels in induced sputum between placebo administration (before, 3,640 pg/mL [SD, 1,020 pg/mL]; after, 3,640 pg/mL [SD, 960 pg/mL] and pranlukast administration (before, 3,660 pg/mL [SD, 940 pg/mL]; after, 2,950 pg/mL [SD, 890 pg/mL]). CONCLUSIONS: Pranlukast administration decreased airway microvascular permeability through, at least in part, a decrease in airway VEGF levels in steroid-untreated asthmatic patients. However, it is likely that pranlukast administration added little efficacy to inhaled corticosteroid therapy for reduction in airway VEGF levels.     

Perception of dyspnea in mild smoking asthmatics

BACKGROUND: Previous data from the literature reported blunted perception of airway obstruction in severe asthmatics with near fatal asthma. Approximately 25% of patients with asthma are current smokers. AIM: To determine whether there is an alteration in perception of airway obstruction during a non specific provocative challenge with methacholine in mild controlled asthmatics who smoke. METHODS: Enrolled in this study were 50 subjects, including 26 mild asthmatics and 24 healthy subjects, all of them current smokers. The first objective was the sensitivity of airway obstruction calculated by the regression slope linking the change in the visual analogic scale (VAS) assessed by the patient and the fall in FEV(1) during a methacholine challenge. RESULTS: Asthmatics who smoke had a blunted perception of airway obstruction during the bronchial challenge significantly different from that seen in healthy smokers (p=0.03). This impaired dyspnea perception was inversely related to baseline VAS (r=-0.29, p<0.05) and positively related to baseline FEV(1) (r=0.35, p<0.05). Perception of airway obstruction was not correlated with age, sex, atopy or with airway inflammation features such as exhaled NO or sputum eosinophils. CONCLUSION: Mild asthmatics who smoke display reduced dyspnea perception during a non-specific provocative challenge with methacholine. This altered perception of airway obstruction does not relate to airway inflammation.