Leukotriene B4 contributes to exhaled breath condensate and sputum neutrophil chemotaxis in COPD.
BACKGROUND
Neutrophils have been implicated in the pathogenesis of COPD. Several chemoattractants for neutrophils have been measured in samples of exhaled breath condensate (EBC) and induced sputum (IS) from patients with COPD. The aims of this study were to compare EBC and IS supernatant neutrophil chemotactic activity (NCA) from ex-smoking subjects with COPD and healthy ex-smokers, and to assess the contribution of leukotriene B(4) (LTB(4)) to this activity.


METHODS
Thirty-four subjects with COPD were compared to 24 control subjects. EBC and IS chemotactic activity for neutrophils was assessed by using Boyden microchambers. The chemotactic index was used to evaluate cell migration. LTB(4) was measured by a specific enzyme immunoassay. The contribution of LTB(4) to EBC and sputum neutrophil chemotaxis was assessed by an LTB(4) receptor antagonist (U-75302; Cayman Chemical Company; Ann Arbor, MI).


RESULTS
EBC and IS samples from both COPD patients and healthy subjects displayed significant NCA, but this activity was raised in COPD patients compared to healthy subjects. The chemotactic activity contained in sputum, however, failed to correlate with that in EBC. In COPD patients, there was a significant correlation between EBC NCA and sputum neutrophil counts. LTB(4) levels were raised in EBC samples, but not in sputum samples, from COPD subjects compared to those from healthy subjects. LTB(4) receptor antagonist concentrations (2.5 x 10(-4) mol/L) reduced by 44.6% and by 44.4%, respectively, the chemotactic activity contained in the EBC and sputum samples.


CONCLUSIONS
EBC and IS from COPD patients have a raised NCA to which LTB(4) contributes.
Corhay
Jean-Louis
JL
Department of Pneumology, Centre Hospitalier Universitaire de Liège, Liège, Belgium. Electronic address: jlcorhay@chu.ulg.ac.be.
Henket
Monique
M
Department of Pneumology, Centre Hospitalier Universitaire de Liège, Liège, Belgium.
Nguyen
Delphine
D
Department of Pneumology, Centre Hospitalier Universitaire de Liège, Liège, Belgium.
Duysinx
Bernard
B
Department of Pneumology, Centre Hospitalier Universitaire de Liège, Liège, Belgium.
Sele
Jocelyne
J
Department of Pneumology, Centre Hospitalier Universitaire de Liège, Liège, Belgium; GIGA Research, University of Liège, Liège, Belgium.
Louis
Renaud
R
Department of Pneumology, Centre Hospitalier Universitaire de Liège, Liège, Belgium.
D001944:Breath Tests; D002634:Chemotaxis, Leukocyte / Q000502:physiology*; D045853:Exhalation; D005233:Fatty Alcohols / Q000494:pharmacology; D006018:Glycols / Q000494:pharmacology; D006801:Humans; D007124:Immunoenzyme Techniques; D007975:Leukotriene B4 / Q000032:analysis / Q000502:physiology*; D009504:Neutrophils / Q000502:physiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D013183:Sputum / Q000166:cytology
D005233:Fatty Alcohols; D006018:Glycols; C062137:U 75302; D007975:Leukotriene B4