Download markers of pulmonary diseases in exhaled breath condensate

REVIEW PAPERS
International Journal of Occupational Medicine and Environmental Health, Vol. 15, No. 4, 317—323, 2002
MARKERS OF PULMONARY DISEASES
IN EXHALED BREATH CONDENSATE
ADAM ANTCZAK and PAWEŁ GÓRSKI
Department of Pneumology and Allergology
Medical University
Łódź, Poland
Abstract. Exhaled breath condensate has been more and more extensively used as a novel and non-invasive method to
study airway inflammation. It is simple to perform, very well tolerated by patients and no adverse events have been reported so far. Serial measurements can be made with no harmful effects on patients, which is of extreme value in occupational medicine. Exhaled breath condensate has been obtained from both adult and children patients suffering from various
pulmonary diseases such as asthma, cystic fibrosis, chronic obstructive pulmonary disease, and interstitial lung diseases.
Several markers and mediators are detectable in breath condensate: hydrogen peroxide, thiobarbituric acid–reactive substances, isoprostanes, prostaglandins and leukotrienes. Nitric oxide–related markers have also been studied in the condensate. There is increasing body of evidence that changes in condensate markers reflect local abnormalities of airway lining fluid.
Key words:
Exhaled breath condensate, Hydrogen peroxide, Leukotrienes, Nitrotyrosine, Asthma, Chronic obstructive pulmonary
disease
INTRODUCTION
Airway inflammation plays an important role in various
respiratory lung diseases, including recurrent wheezing,
asthma, cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) [1,2]. Several attempts have been
made therefore to detect and monitor inflammatory
changes and mediators using non-invasive methods.
There is also a need for objective and early criteria to
evaluate airway inflammation. The first useful and valuable step has been made by measuring bronchial hyperresponsiveness to methacholine, which, indeed, provides
complementary information on symptoms, lung function,
and the course and prognosis of diseases. More recent
efforts have been made to detect markers in induced sputum and exhaled markers of airway inflammation [3].
The diagnosis of occupational lung diseases in general
and occupational asthma in particular, needs to be more
objective and based on a wider range of criteria.
Frequently used measurements (metacholine airway
responsiveness, diurnal and at work variations of peak
expiratory flow, cannot be performed optimally and are
often insufficient in occupational medicine, and further
measurements may prove more useful. Measurements of
exhaled breath condensate (EBC) that can be made at
workplace directly and noninvasively, and last but not
least repeatedly over short periods of time could be valuable in occupational medicine. Inflammatory mediators
in EBC that increase at work in most patients with occupational lung disease can be used as objective evidence to
support the diagnosis.
Unfortunately, the collection of sputum induced by
inhalation of hypertonic saline may irritate the airways
and subsequently becomes similar to bronchial challenge
tests [4]. Repetitive measurements are also not recom-
* Address reprint requests to Prof. P. Górski, M.D., Ph.D., Department of Pneumology and Allergology, Medical University, Kopcińskiego 22, 90-153 Łódź, Poland (email: [email protected]).
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A. ANTCZAK, P. GÓRSKI
mended due to cell count changes and proinflammatory
action of sputum induction over short period of time.
Exhaled nitric oxide (NO) is the most extensively studied
exhaled marker, and abnormalities in NO levels have
been documented in several lung diseases [5].
Recently, EBC has been more and more extensively used
as a novel and non-invasive method to study airway
inflammation. It is extremely simple to perform, very
well tolerated by patients and no adverse events have
been reported so far. Moreover, it seems valuable in
occupational medicine, in which serial measurements to
monitor the impact of work environment and exposure
estimates on lung function can be made without harmful
effects on patients. The measurement can be performed
in each subject and be repeated as often as possible. A
15-min time of collection seems to be sufficient to obtain
samples. If analysis is restricted to a single marker or
mediator only a few minutes of tidal breathing are sufficient for an adequate sample. Forced breathing should
be avoided. Sampling can be interrupted any time.
Condensate collection should not be performed on the
same day or in case of respiratory insufficiency requiring
support of respiration. The volatile and non-volatile substances in human breath can potentially be used in the
assessment of airway inflammation, based on the
assumption that aerosol particles and vapor in exhaled
air reflect the composition of the lower airway fluids.
However, there are no sufficiently convincing data providing clear evidence on the source of particles present
in EBC, and only theoretical considerations have arrived
at the conclusion that the exhaled breath and exhaled
breath condensate mainly represent the biochemical situation in the lower airways.
Breath condensate mainly consists of water but also of
inorganic salts and oxides of about 10 ppm, lipids, hydrocarbons and proteins. The reliable determination of these
compounds is fundamental for diagnosing respiratory disorders using exhaled breath condensate (Table 1).
The composition of the condensate is very complex. There
are several hints indicating that EBC consists of two phases
(vapor and aerosol), which constitute breath condensate.
The vapor phase consists mainly of non-water soluble biomolecules potent to form binary systems with water in the
watery surface of the lung [6]. Leukotrienes and
prostaglandins are good examples of molecules that normally are only hardly volatile and can evaporate easily in
the vapor phase of breath condensate [7]. Many proteins
can be expired via the aerosol phase of the condensate. As
shown by Papineni [8] the lungs produce aerosols under
tidal breathing conditions, and a relatively low number of
particles per liter of exhaled air can be increased if a deep
exhalation maneuver or coughing before the breath analysis is performed. These findings confirm a hypothesis that
aerosol particles are formed in the peripheral compartments of the lung and are exhaled.
Condensate constituents reflect different molecules from
oral cavity and oropharynx, alveoli, and their proportional contribution has not as yet been clearly defined.
Table 1. Markers of inflammation in exhaled breath condensate
Compound
318
Asthma
COPD
Smokers
CF
ARDS
Bronchiectases
H2O2
+
+
+
+
+
+
8-Isoprostane
Thiobarbituric
acid-reactive products
+
+
+
?
+
?
Nitrotyrosine
Nitrosothiols
Nitrite/Nitrates
+
+
+
+
?
?
pH
+
+
?
?
?
?
Leukotrienes
PGE2
+
+
?
+
+
?
Cytokines
?
?
?
+
?
?
IJOMEH, Vol. 15, No. 4, 2002
MEDIATORS IN EXHALED BREATH CONDENSATE
However, a general idea of breath condensate collection
consists in the expiration of breathing air through a condenser cooled down by ice, dry ice or by cooling liquid
REVIEW PAPERS
in the airways. EBC provides an easy to perform means of
exploring the airways without the need to undertake invasive procedures, such as bronchoscopy.
(Fig. 1). An important factor for the sample quality seems
to be temperature, the lower the better especially for
eicosanoids that are highly unstable. There is also a risk of
saliva contamination, which potentially influences the levels of different markers in breath condensate. Saliva is a
reach source of hydrogen peroxide and high levels of
eicosanoids have been observed in saliva from asthmatic
patients. Therefore, amylase as a good marker of saliva
contamination should be monitored when obtaining
breath condensate and the subjects should be asked to
rinse the mouth before and during collection.
Fig. 1. Exhaled breath condensing cooling system – schematic presentation.
OXIDATIVE STRESS
Oxidative stress – an imbalance of oxidants/antioxidants
in favor of oxidants has been implicated in the pathophysiology of a number of respiratory disorders such as asthma, COPD and CF [9]. Activation of eosinophils, neutrophils, and macrophages induces a respiratory burst,
resulting in the production of reactive oxygen species
(ROS) that cause tissue damage and cell death. Lung
cells, in particular alveolar epithelial type II cells, are particularly susceptible to the injurious effects of oxidants.
Therefore, oxidative stress and overall inflammatory
response are a fundamental process involved in pathogenesis of many lung diseases [10]. EBC might be utilized in
detecting and assessing oxidative stress non-invasively and
in giving an opportunity to investigate the local processes
MARKERS OF OXIDATIVE STRESS
Hydrogen peroxide (H2O2)
An important source of H2O2 are phagocytes. Activated
cells generate O2•-, which is converted to H2O2 by superoxide dismutase and hydroxyl radical, formed non-ezymatically in the presence of Fe2+. An intense airway
inflammation can be caused either by H2O2 alone or by
newly generated hydroxyl radical [10].
H2O2 is released in extracellular fluid. In the airways, part
of H2O2, which has not been decomposed by antioxidant
enzymes, can be exhaled with exhaled breath. H2O2 is elevated in EBC in various inflammatory lung disorders, such
as asthma [11,12], CF [13], bronchiectasis [14], adult respiratory distress syndrome (ARDS) and acute hypoxemic
respiratory failure [15], cigarette smoking [16], and COPD
[17]. Cigarette smoking is a strong pro-inflammatory and
pro-oxidant factor and therefore, high levels of H2O2 have
been found in EBC from smokers compared to non-smoking subjects [18]. Increased H2O2 levels have been found
in EBC in a relatively small group of asthmatic children,
mainly in those with acute disease, however, elevated
H2O2 in stable asthmatics has been also observed [19]. As
postulated by Horvath and co-workers [20] measurements
of H2O2 in EBC and exhaled NO in asthmatic patients
provides complementary data for monitoring the disease
progress. Exhaled H2O2 may be used not only as a diagnostic test but also to guide anti-inflammatory treatment.
Inhaled beclomethasone in low dose has been shown to
decrease H2O2 in EBC in a 2-week treatment [21]. This
has been also observed in children with stable asthma,
part of them received inhaled cortiosteroids daily ]12].
There was a significant difference in median H2O2 concentration between asthmatics without anti-inflammatory
treatment and healthy controls. A study of ARDS patients
treated with corticosteroids showed a tendency towards
lowering the levels of H2O2 in the expired air condensate
as compared to steroid-naive ARDS patients [22]. In a
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A. ANTCZAK, P. GÓRSKI
recent study, it has been observed that long-term treatment of N-acetylcysteine (600 mg daily) decreases H2O2
exhalation in COPD patients [23]. Both, asthma and CF
patients with an acute pulmonary exacerbation have
abnormally high levels of exhaled H2O2, which decrease
during antibiotic treatment [24].
Products of lipid peroxidation
Thiobarbituric acid-reactive substances
Measurement of thiobarbituric acid-reactive substances
(TBARS) is a simple method, but non-specific to assess
lipid peroxidation damage in tissues, cells and body fluids.
TBARS levels are increased in exhaled breath condensate
in asthma [11] and COPD [25] and they increase during
exacerbations [24]. Increased levels of conjugated dienes in
EBC in bronchial biopsies from patients with COPD and
simple chronic bronchitis have also been observed [26].
8-Isoprostane
8-Isoprostane, stable prostaglandin-like arachidonate
product formed by ROS on membrane phospholipids is
postulated to be a reliable biomarker of lipid peroxidation
caused by reactive oxygen species and represent a quantitative measure of oxidant stress in vivo [27]. 8-Isoprostane
appears to reflect oxidative stress in EBC. It progressively
increases with increasing severity of asthma, reaching very
high levels in aspirin-induced asthma [28,29]. It is also
reported to be increased in EBC in COPD patients [30]
and further goes up in exacerbated COPD [31]. There was
also observed a positive correlation between exhaled
H2O2 and 8-isoprostane levels, which might reflect the
cause-effect relationship (A. Antczak, unpublished data).
8-Isoprostane has also been detected in EBC from ARDS
patients [32].
Nitrogen-reactive species
Nitrotyrosine
Nitrotyrosine formation in EBC may be a marker of
nitrosative-oxidative stress in airways. NO is able to react
with superoxide anions in the airways to form peroxynitrite,
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IJOMEH, Vol. 15, No. 4, 2002
a highly reactive species. Peroxynitrite in reaction with tyrosine residues in proteins forms a stable product - nitrotyrosine. Nitrotyrosine concentrations have been detected in
EBC of normal subjects, and were increased significantly in
patients with mild asthma [33]. However, the levels of
nitrotyrosine in EBC have been higher in mild than in moderate or severe asthma. Moreover, there was a significant
correlation between nitrotyrosine in EBC and exhaled NO
in patients with mild asthma [33]. Exhaled NO is decreased
in CF patients, perhaps because it is metabolized to oxidative end-products. 3-Nitrotyrosine may indicate local ROS
formation. Nitrotyrosine levels in EBC were significantly
increased in stable CF patients compared with normal subjects. There was an inverse correlation between the levels of
nitrotyrosine and the severity of lung disease [34].
Production of nitrotyrosine may reflect increased formation of reactive nitrogen species, such as peroxynitrite or
direct nitration by granulocyte peroxidases, indicating
increased oxidative stress in airways of CF patients [34].
Nitrosothiols
Nitrosothiols (RS-NOs) are formed by interaction
between NO and glutathione. RS-NOs are detectable in
EBC of healthy subjects and are increased in patients with
inflammatory lung diseases. RS-NOs in EBC were higher
in subjects with severe asthma versus normal subjects and
those with mild asthma [35]. Elevated RS-NOs were also
found in CF patients and in smokers. In current smokers,
RS-NOs values correlated with smoking history
(pack/year). As RS-NOs concentrations in EBC vary in
different airway diseases, and increase with increasing
severity of asthma, it is postulated that their measurement
may have clinical relevance as a non-invasive biomarker of
oxidative-nitrosative stress.
Nitrites/nitrates
Nitrite (NO2) and nitrate (NO3) are end-products of NO
oxidation. Total EBC NO2/NO3 concentrations were significantly higher in CF patients and smokers than in
healthy controls [36,37]. They were also higher in patients
with asthma than in normal subjects [38]. Inhaled steroid
MEDIATORS IN EXHALED BREATH CONDENSATE
therapy led to decreased levels of NO2/NO3 in EBC. A
positive correlation between NO2/NO3 levels and H2O2
concentrations in EBC from asthmatic patients was also
observed [38].
REVIEW PAPERS
ences in exhaled PGE2 levels from COPD patients and
healthy controls [45].
Leukotrienes
Cysteinyl-leukotrienes (LTE4, LTC4, LTD4) are strong
pro-inflammatory products of arachidonic acid metabo-
Cytokines
Measurement of proteins in exhaled breath condensate is
difficult due to very low concentrations of these biomolecules in the condensate. It has been shown by Balint et al.
[39] that Il-8 is increased in breath condensate from
unstable CF patients. Higher total protein levels were
observed in exhaled breath condensate from smokers
compared to non-smokers, but tumor necrosin factor-α
(TNF-α) did not show any difference [40]. We found
undetectable TNF-α in the condensate (A. Antczak,
unpublished data). The assessment of proteins in EBC
obviously needs more precise and sensitive methods. A
proteomics technique is of considerable interest (inverse
acute phase proteins observed in EBC - information from
dr Ian Adcock, Imperial College, London, UK).
lism. They are detectable in EBC from healthy subjects
and in higher levels in asthmatic patients. Particularly high
levels of cys-LTs are observed in EBC from aspirininduced asthmatic patients. Moreover, they decrease after
steroid treatment [44].
As shown by Hanazawa et al. [33] there is further increase
in cys-LTs after allergen challenge in mild asthmatic
patients. Moreover, withdrawal of steroids in these
patients was accompanied not only by clinical deterioration but also by significant increase in cys-LTs levels in
EBC.
We have not observed increased LTB4 levels in asthmatic
patients [44]. On the contrary, unstable COPD patients
had higher levels of LTB4 in EBC compared to stable and
healthy subjects. They decreased during treatment, however, they were still higher than in healthy subjects [45].
Eicosanoids
Prostaglandins
Prostaglandin E2 (PGE2) relaxes airway smooth muscles
and exerts potent anti-inflammatory activity [41].
Diminished PGE2 levels in bronchoalveolar lavage (BAL)
obtained from aspirin-sensitive asthmatic patients were
observed to further decrease after aspirin administration
[42]. Moreover, inhaled PGE2 can inhibit aspirin-induced
bronchoconstriction and urinary leukotriene E4 (LTE4)
excretion [43]. It is postulated that the failure in PGE2breaking mechanism with increased sensitivity to inhibition by non-steroidal anti-inflammatory drugs (NSAIDs)
is responsible for overproduction of cys-LTs in aspirin
asthma.
PGE2 levels are neither increased in EBC from asthmatic
patients nor decreased in EBC from patients with aspirinsensitive asthma, thus giving an assumption that PGE2
deficiency is not responsible for the development of symptoms in aspirin-induced patients [44]. There are no differ-
pH
A low pH of exhaled breath condensate has been
observed in exacerbation of asthma and COPD [46,47].
This can be associated with increased concentrations of
lactic acid as shown in patients with acute bronchitis [48].
CONCLUSIONS
There is accumulating evidence that abnormalities in
exhaled breath condensate composition may reflect biochemical changes in airway lining fluid. Detecting and
monitoring biomarkers in exhaled breath condensate may
be helpful in the diagnosis and follow-up of patients with
various pulmonary diseases.
REFERENCES
1. Barnes PJ. Chronic obstructive pulmonary disease. New Eng J Med
2000; 342: 269–80.
IJOMEH, Vol. 15, No. 4, 2002
321
REVIEW PAPERS
A. ANTCZAK, P. GÓRSKI
2. Rahman I, Morrison D, Donaldson K, McNee W. Systemic oxidative
16. Nowak D, Antczak A, Król M, Pietras T, Shariati B, Bialasiewicz P,
stress in asthma, COPD, and smokers. Am J Crit Care Respir Med
et al. Increased content of hydrogen peroxide in expired breath of cig-
1996; 154: 1055–60.
arette smokers. Eur Respir J 1996; 9: 652–7.
3. Pavord ID, Pizzichini MMM, Pizzichini E, Hargreave FE. The use of
17. Dekhuijzen PN, Aben KK, Dekker I, Aarts LP, Wielders PL, van
induced sputum to investigate airway inflammation. Thorax 1997; 52:
Herwaarden CL, et al. Increased exhalation of hydrogen peroxide in
498–501.
patients with stable and unstable chronic obstructive pulmonary dis-
4. Antczak A, Kharitonov SA, Barnes P. Exhaled nitric oxide and carbon
monoxide are elevated after sputum induction. Am J Crit Care Respir
Med 2000; 161: A32.
5. Kharitonov SA, Chung KF, Evans D, O’Connor BJ, Barnes PJ.
Increased exhaled nitric oxide in asthma is mainly derived from lower
respiratory tract. Am J Respir Crit Care Med 1996; 153: 1773–80.
6. Fairchild CI, Stampfer JF. Particle concentration in exhaled breath.
Am Ind Hyg Assoc J 1987; 48: 948–9.
7. Rothe M. Breath condensate measurements. Developement, collection,
storage and analysis. Info Jaeger 2001; 1: 13–6.
18. Kasielski M, Nowak D, Antczak A, Pietras T, Krol M. Increased
content of hydrogen peroxide in the expired breath condensate of
patients with chronic obstructive pulmonary disease. Cur Pneumol
1997; 1: 47–51.
19. Dohlman AW, Black HW, Royall JA. Expired breath hydrogen peroxide is a marker of acute airway inflammation in pediatric patients with
asthma. Am Rev Respir Dis 1993; 148: 955–60.
20. Horvath I, Donnelly L, Kiss A, Kharitonov SA, Lim S, Chung KF,
et al. Combined use of exhaled hydrogen peroxide and nitric oxide in
monitoring asthma. Am J Crit Care Respir Med 1998; 158:1042–6.
8. Papineni RS, Rosenthal FS. The size distribution of droplets in the
21. Antczak A, Kurmanowska Z, Kasielski M, Nowak D. Inhaled glu-
exhaled breath of healthy human subjects. J Aerosol Med 1997; 10:
cocorticosteroids decrease hydrogen peroxide in expired air condensate
105–16.
in asthmatic patient. Respir Med 2000; 94: 416–21.
9. Barnes PJ. Reactive oxygen species and airway inflammation. Free
Rad Biol Med 1990; 9: 235–43.
10. Joseph BZ, Routes JM, Borish L. Activities of superoxide dismutase
and NADPH oxidase in neutrophils obtained from asthmatic and normal donors. Inflammation 1993; 17: 361–70.
11. Antczak A, Nowak D, Krol M, Shariati B, Kurmanowska Z.
22. Kietzman D, Kah R, Muller M, Burchardi H, Kettler D. Hydrogen
peroxide in expired breath condensate of patients with acute respiratory failure and with ARDS. Intensive Care Med 1993; 19: 78–81.
23. Kasielski M, Nowak D. Long-term administration of N-acetylcysteine
decreases hydrogen peroxide exhalation in subjects with chronic
obstructive pulmonary disease. Respir Med 2001; 95: 448–56.
Increased hydrogen peroxide and thiobarbituric acid-reactive products
24. Antczak A, Gorski P. Antibiotic treatment decreases hydrogen perox-
in expired breath condensate of asthmatic patients. Eur Respir J 1997;
ide and thiobarbituric acid–reactive substances in expired air conden-
10: 1231–41.
12. Jobsis Q, Raatgeep HC, Hermans PWM, de Jongste JC. Hydrogen
peroxide in exhaled air is increased in stable asthmatic children. Eur
Respir J 1997; 10: 519–21.
13. Jobsis Q, Raatgeep HC, Schellekens SL, Kroesbergen A, Hop WC,
de Jongste JC. Hydrogen peroxide and nitric oxide in exhaled air of
children with cystic fibrosis during antibiotic treatment. Eur Respir J
2000; 16: 95–100.
322
ease. Am J Crit Care Respir Med 1997; 154: 813–6.
sate in infectious exacerbation of bronchial asthma. Int Rev Allergol
Clin Immunol 2000; 6: 52–5.
25. Nowak D, Kasielski M, Pietras T, Bialasiewicz P. Cigarette smoking
does not increase hydrogen peroxide levels in expired breath condensate of patients with stable COPD. Monaldi Arch Chest Dis 1998; 53:
268–73.
26. Ignatova GL, Volchegorskii IA, Volkova EG, Kazachkov EL,
Kolesnikov OL. Lipid peroxidation processes in chronic bronchitis.
Terapii Arkhiv 1998; 70: 36–7 [in Russian].
14. Loukides S, Horvath I, Wodehouse T, Cole PJ, Barnes PJ. Elevated
27. Montuschi P, Kharitonov SA, Ciabattoni G, Corradi M, van Rensen
levels of expired breath hydrogen peroxide in bronchiectasis. Am J Crit
L, Geddes DM, et al. Exhaled 8-isoprostane as a new non-invasive
Care Respir Med 1998; 158: 991–4.
biomarker of oxidative stress in cystic fibrosis. Thorax 2000; 55: 205–9.
15. Sznajder JI, Fraiman A, Hall JB, Sanders W, Schmidt G, Crawford
28. Montuschi P, Corradi M, Ciabattoni G, Nightingale J, Kharitonov
G, et al. Increased hydrogen peroxide in the expired breath condensate
SA, Barnes PJ. Increased 8-isoprostane, a marker of oxidative stress,
of patients with acute hypoxemic respiratory failure. Chest 1989; 96:
in exhaled condensate of asthma patients. Am J Crit Care Respir
606–12.
Med 1999; 160: 216–20.
IJOMEH, Vol. 15, No. 4, 2002
MEDIATORS IN EXHALED BREATH CONDENSATE
REVIEW PAPERS
29. Antczak A, Kharitonov SA, Montuschi P, Gorski P, Barnes PJ.
40. Scheideler L, Manke HG, Schwulera U, Inacker O, Hammerle H.
Increased 8-isoprostane in aspirin-induced asthma. Eur Respir J
Detection of nonvolatile macromolecules in breath. A possible diag-
2001; 18: 247.
nostic tool? Am Rev Respir Dis 1993; 148: 778–84.
30. Montuschi P, Collins JV, Ciabattoni G, Lazzeri N, Corradi M,
41. Jakobsson PJ, Thoren S, Morgenstern R, Mancici J, Ford-
Kharitonov SA, et al. Exhaled 8-isoprostane as an in vivo biomarker
Huchinson A, Person B. Identification of human prostaglandin E
of lung oxidative stress in patients with COPD and healthy smokers.
synthase: a microsomal, glutathione-dependent, inducible enzyme,
Am J Crit Care Respir Med 2000; 162: 175–7.
constituting a potential novel drug target. Proc Natl Acad Aci USA
31. Antczak A, Gorski P. Increased cysteinyl-leukotrienes, leukotriene B4
and 8-isoprostane in exacerbation of COPD. Eur Respir J 2001; 18:
248.
32. Carpenter CT, Price P, Christmas B. Exhaled breath condensate isoprostanes are elevated in patients with acute lung injury and ARDS.
Chest 1998; 114: 1653–9.
1999; 96: 7220–5.
42. Szczeklik A, Sladek K, Dworski R, Nizankowska E, Soja J, Sheller
J, et al. Bronchial aspirin challenge causes specific eicosanoid
response in aspirin-sensitive asthmatics. Am J Respir Crit Care Med
1996; 154: 1608–14.
43. Sestini P, Armetti L, Gambaro G, Pieroni M, Refini RM, Sala A, et
33. Hanazawa T, Kharitonov SA, Barnes PJ. Increased nitrotyrosine in
al. Inhaled PGE2 prevents aspirin-induced bronchoconstriction and
exhaled breath condensate of patients with asthma. Am J Crit Care
urinary LTE4 excretion in aspirin-sensitive asthma. Am J Respir Crit
Respir Med 2000; 162:1273–6.
Care Med 1996; 53: 572–5.
34. Balint B, Kharitonov SA, Hanazawa T, Donnelly LE, Shah PL,
44. Antczak A, Montuschi P, Kharitonov SA, Gorski P, Barnes PJ.
Hodson ME, et al. Increased nitrotyrosine in exhaled breath conden-
Increased levels of cysteinyl-leukotrienes in exhaled air condensate of
sate in cystic fibrosis. Eur Respir J 2001; 17: 1201–7.
aspirin-induced asthmatic patients. Am J Respir Crit Care Med.
35. Corradi M, Montuschi P, Donnelly LE, Pesci A, Kharitonov SA,
Barnes PJ. Increased nitrosothiols in exhaled breath condensate in
2001; 163 (5): A47.
45. Antczak A, Gorski P. Increased exhaled cysteinyl-leukotrienes,
inflammatory airway diseases. Am J Crit Care Respir Med 2001;
leukotriene B4 and 8-isoprostane in exacerbation of COPD. Eur
163: 854–8.
Respir J 2001; 18 (Suppl. 33): 248.
36. Ho LP, Innes JA, Greening AP. Nitrite levels in breath condensate of
46. Hunt JF, Fang K, Malik R, Snyder A, Malthora N, Platts-Mills TA,
patients with cystic fibrosis is elevated in contrast to exhaled nitric
et al. Endogenous airway acidification: implications for asthma
oxide. Thorax 1998; 53: 680–4.
pathophysiology. Am J Respir Crit Care Med. 2000; 161: 694–9.
37. Balint B, Hanazawa T, Kharitonov SA, Donnelly LE, Barnes PJ.
47. Antczak A, Gorski P. Endogenous airway acidification and oxidant
Increased nitric oxide metabolites in exhaled breath condensate after
overload in infectious exacerbation of COPD. Am J Respir Crit Care
exposure to tobacco smoke. Thorax 2001; 56: 456–61.
Med. 2001; 163 (5): A725.
38. Ganas K, Loukides S, Papatheodorou G, Panagou P,
48. Goncharova VA, Borisenko LV, Dotsenko EK, Pokhaznikova MA.
Kalogeropoulos N. Total nitrite/nitrate in expired breath condensate
Kallikreinikinin indices and biological composition of exhaled con-
of patients with asthma. Respir Med 2001; 95: 649–54.
densate in acute bronchitis patients with varying disease course. Klin
39. Balint B, Kharitonov SA, Kazuhiro I, Shah P, Geddes B, Hodson
Med 1996; 74: 46–8.
ME, et al. Increased Il-8 in exhaled breath condensate in cystic fibro-
Received for publication: February 20, 2002
sis during acute exacerbation. Eur Respir J 2001; 18 (Suppl 33): 537.
Approved for publication: October 30, 2002
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