Exhaled leukotrienes and prostaglandins in COPD.
BACKGROUND
The role of eicosanoids, including leukotrienes (LTs) and prostaglandins (PGs), in chronic obstructive pulmonary disease (COPD) is uncertain. The aim of this study was to investigate whether eicosanoids are measurable in exhaled breath condensate (EBC), a non-invasive method of collecting airway secretions, in patients with stable mild to moderate COPD, and to show possible differences in their concentrations compared with control subjects.


METHODS
LTB(4), LTE(4), PGE(2), PGD(2)-methoxime, PGF(2alpha), and thromboxane B(2) (TxB(2)) were measured in EBC in 15 healthy ex-smokers, 20 steroid naïve patients with COPD who were ex-smokers, and in 25 patients with COPD who were ex-smokers and who were treated with inhaled corticosteroids. The study was of cross sectional design and all subjects were matched for age and smoking habit.


RESULTS
LTB(4) and PGE(2) concentrations were increased in steroid naïve (LTB(4): median 100.6 (range 73.5-145.0) pg/ml, p<0.001; PGE(2): 98.0 (range 57.0-128.4) pg/ml, p<0.001) and steroid treated patients with COPD (LTB(4): 99.0 (range 57.9-170.5) pg/ml, p<0.001; PGE(2): 93.6 (range 52.8-157.0) pg/ml, p<0.001) compared with control subjects (LTB(4): 38.1 (range 31.2-53.6) pg/ml; PGE(2): 44.3 (range 30.2-52.1) pg/ml). Both groups of patients had similar concentrations of exhaled LTB(4) (p=0.43) and PGE(2) (p=0.59). When measurable, LTE(4) and PGD(2)-methoxime concentrations were similar in COPD patients and controls, whereas PGF(2alpha) concentrations were increased in the former. TxB(2)-LI was undetectable in any of the subjects.


CONCLUSIONS
There is a selective increase in exhaled LTB(4) and PGE(2) in patients with COPD which may be relatively resistant to inhaled corticosteroid therapy.
Montuschi
P
P
Department of Pharmacology, School of Medicine, Catholic University of the Sacred Heart, Rome, Italy. pmontuschi@rm.unicatt.it
Kharitonov
S A
SA
Ciabattoni
G
G
Barnes
P J
PJ
D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage; D000368:Aged; D001944:Breath Tests; D003430:Cross-Sectional Studies; D015237:Dinoprost / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007975:Leukotriene B4 / Q000378:metabolism; D017999:Leukotriene E4 / Q000378:metabolism; D015289:Leukotrienes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015230:Prostaglandin D2 / Q000378:metabolism; D011453:Prostaglandins / Q000378:metabolism*; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D013929:Thromboxane B2 / Q000378:metabolism; D014797:Vital Capacity / Q000502:physiology
D000305:Adrenal Cortex Hormones; D015289:Leukotrienes; D011453:Prostaglandins; D007975:Leukotriene B4; D013929:Thromboxane B2; D017999:Leukotriene E4; D015237:Dinoprost; D015232:Dinoprostone; D015230:Prostaglandin D2