To study whether the individual inflammatory response to ozone was reproducible, dose-dependent, and time-dependent, we performed two exposures to 250 ppb ozone, one to 125 ppb and one to filtered air, each for 3 h of intermittent exercise and separated by at least 1 wk. Twenty-one healthy and 15 asthmatic subjects participated in the study. One hour after the two exposures to 250 ppb ozone we observed a mean increase in sputum neutrophils of 17.9 and 17.9% in healthy and of 20.3 and 15.2% in asthmatic subjects (p < 0.05 each). Twenty-four hours after exposure, the respective values were 11.9 and 14.8%, and 9.1 and 16.1% (p < 0.05 each). In the whole group of subjects, individual changes in the percentage of neutrophils were significantly correlated between the two exposure days 1 h (r = 0.87, p < 0.001; intraclass correlation coefficient [Ri] = 0.86) as well as 24 h (r = 0.79, p < 0.001; Ri = 0.71) after exposure. The percentages of lymphocytes were increased 24 h after exposures (all subjects combined: p < 0.05). The decrease in FEV1 in both groups (p < 0.01), was also reproducible (r = 0.77, p < 0.001), but there were no correlations between changes in sputum parameters and lung function. Exposure to 125 ppb ozone caused a small increase (p < 0. 05) in the percentage of neutrophils in asthmatic subjects and in the concentrations of interleukin-8 in both groups combined. Our data demonstrate that inflammatory and lung function responses to ozone differ between individuals and are reproducible but not related to each other. Therefore, these responses appear to represent two independent factors underlying the airway response to ozone.

Abstractcidated which could influence the results. 3 It has not been ascertained, however, whether the Background -Sputum induction is a noninvasive method for obtaining cellular and induction procedure itself affects the composition of sputum samples obtained in a secbiochemical material from the airways and appears to be particularly suited for ond induction.This question is of interest because sputum repeated testing. However, it has not been clarified whether repeated inductions lead analysis appears to be particularly suited to being performed repeatedly within a short time. to a change in sputum composition. The aim of this study was to compare induced However, data on the effects of repeated sputum inductions, without therapeutic intersputum results between two inductions performed 24 hours apart.ventions, are scarce and conflicting. [4][5][6][7] The aim of our study was therefore to compare sputum Methods -Ten subjects with mild asthma and 19 healthy subjects were included. composition between two inductions performed 24 hours apart in healthy subjects and Sputum was obtained during three consecutive 10 minute periods of hypertonic subjects with mild asthma. To ensure comparability with data in the literature we adhered saline inhalation. Samples were analysed separately for the three inhalation periods. to a previously validated induction procedure. 8Corresponding pooled values were computed, taking into account total cell numbers of each inhalation period. Methods Results -In the three consecutive inhala- tion periods mean (SE) percentages of Ten subjects with mild bronchial asthma (mean neutrophils increased from 29.2 (4.2)%, (SD) age 30 (9) years; forced expiratory volume 22.0 (4.6)% and 14.5 (2.9)% on day 1 to in one second (FEV 1 ) 95 (8)% predicted 9 ) and 43.1 (5.3)%, 34.8 (5.5)% and 25.7 (5.3)% on 19 healthy subjects (age 26 (5) years; FEV 1 day 2 in healthy subjects and from 21.3 105 (13)% predicted) were studied. The dia-(4.3)%, 24.1 (5.9)% and 15.9 (3.7)% to 35.9 gnosis of bronchial asthma followed inter-(6.9)%, 30.7 (7.1)% and 31.8 (6.5)% in asth-nationally accepted criteria.10 All subjects with matic subjects. This parallel shift cor-asthma showed a positive skin prick test to at responded to a mean (95% CI) increase in least one common allergen (Allergopharma, the pooled percentages of neutrophils of Reinbek, Germany) and were hyperresponsive 17.4 (11.6 to 23.3)% in healthy and 14.6 (1.2 to methacholine, their provocative concento 28.0)% in asthmatic subjects. In contrast trations (PC 20 FEV 1 ) being less than 8 mg/ml to neutrophils, the percentage of macro-(geometric mean (SD) 0.44 (3.9) mg/ml). phages decreased from day 1 to day 2, None had taken inhaled corticosteroids within into account when repeated sputum in-formed out of season. All subjects were nonGermany duction is performed. smokers and had not suffered an upper res-O Holz (Thorax 1998;53:83-86) piratory tract infection within the four weeks K Richter R A Jörres preceding the study. The tests were approved P Speckin

The present study aimed at delineating the mechanisms underlying the adverse response to hypertonic saline inhalation in patients with chronic obstructive pulmonary disease (COPD). Twenty patients (age, 48-70 yr; FEV(1), 29-58 %pred) inhaled, on two different days in randomized order, 200 microg salbutamol from an MDI and 20 min later either 0.9% or 3% saline from an ultrasonic nebulizer for a maximum of four consecutive 5-min periods. Forced expiratory (FEV(1)) and inspiratory (FIV(1)) volumes, inspiratory capacity (IC), intrathoracic gas volume (ITGV), and specific airway resistance (SRaw) were measured. Significant changes occurred in FEV(1), FIV(1), IC, ITGV, and SRaw with both concentrations (p < 0.05, each) and effects were stronger with 3% as compared with 0.9% saline (p < 0.05, each). The increase in dyspnea was associated with the changes in FIV(1), FEV(1), IC, and ITGV, in contrast to its decrease during bronchodilation, where only FIV(1) was important. Sputum analysis showed elevated concentrations of histamine after 3% as compared with 0.9% saline. These data indicate that the adverse lung function response to hypertonic saline is common in patients with moderate to severe COPD, involves both bronchoconstriction and lung hyperinflation, and could be mediated, at least partially, through activation of mast cells.

It has been demonstrated that consecutive samples of induced sputum may differ with respect to cellular composition. The aim of this study was to compare two sequential sputum samples in patients with chronic obstructive pulmonary disease (COPD) and asthma with different severity.Two sputum inductions were performed 30 min apart and processed separately in healthy subjects (n=11), patients with moderate to severe COPD (n=10), asthmatics treated with b 2 -agonists alone (group 1, n=11), inhaled steroids (group 2, n=12) or systemic steroids (group 3, n=7).In healthy subjects and asthma group 2, percentages of neutrophils decreased significantly between the two sputum inductions but did not change in COPD and asthma group 3. Percentages of eosinophils did not change significantly in any group of patients. Concentrations of interleukin (IL)-8 decreased significantly in the control group and asthma groups 1 and 2 but not in asthma group 3 and the COPD group.These data demonstrate differences in sputum composition between two consecutive samples which were most pronounced in healthy subjects. Therefore, pooling of sputum samples may affect the results, particularly in healthy subjects, in contrast to subjects with more severe asthma or chronic obstructive pulmonary disease. These findings may be suggestive of differences in the distribution of inflammation along the airways between distinct airway diseases.

Our data suggest that repeated exposure to ozone, at a peak ambient air level, can enhance both functional and inflammatory responses to inhaled allergen in subjects with pre-existing allergic airway diseases, and that these effects might reach a clinically relevant magnitude.