Prednisone blunts airway neutrophilic inflammatory response due to ozone exposure in asthmatic subjects.
BACKGROUND
The effect of corticosteroids on the ozone (O3)-induced airway inflammation is still debated.


OBJECTIVE
The aim of the study was to confirm the effect of a short-term treatment with oral glucocorticosteroids on O3-induced airway inflammation, detected by induced sputum analysis, and on functional response in glucocorticosteroid-naive subjects.


METHODS
A randomized, placebo-controlled study using oral prednisone (25 mg o.d. for 4 days) was carried out. Nine mild persistent asthmatics were exposed for 2 h, on separatedays, to 0.27 ppm O3 and to air in random order, after 4 days of treatment with prednisone (25 mg o.d.) and after 4 days of placebo.Before and after exposure, pulmonary function test was measured; 6 h afterexposure, sputum induction was done.


RESULTS
Oral glucorticosteroids did not prevent pulmonary function decrement due to O3. After placebo, the percentage of neutrophils in induced sputum was significantly higher after O3 than after air [52.1 (15.7-77.3) vs. 17.8 (1.7-58.4), p=0.02, O3 vs. air]. This difference was lost after 4 days of treatment with prednisone [35.2% (10-96.2) vs. 30.9% (6.1-75.6), n.s., O3 vs. air]. Neutrophil elastase in sputum supernatant increased after O3 exposure in the sample obtained after placebo, but not after prednisone treatment.


CONCLUSIONS
This study confirms that glucocorticosteroids reduce inflammatory airway response, but do not prevent the airway functional impairment after O3 exposure.
Vagaggini
Barbara
B
Pneumology Section, Cardiothoracic Department, University of Pisa, Pisa, Italy. b.vagaggini@ao-pisa.toscana.it
Cianchetti
Silvana
S
Bartoli
Marialaura
M
Ricci
Manrico
M
Bacci
Elena
E
Dente
Federico L
FL
Di Franco
Antonella
A
Paggiaro
Pierluigi
P
D000280:Administration, Inhalation; D000284:Administration, Oral; D000328:Adult; D001249:Asthma / Q000188:drug therapy* / Q000473:pathology; D001991:Bronchitis / Q000139:chemically induced / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D019272:Leukocyte Elastase / Q000378:metabolism; D008297:Male; D009504:Neutrophils / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D010083:Oxidants, Photochemical / Q000008:administration & dosage / Q000009:adverse effects*; D010126:Ozone / Q000008:administration & dosage / Q000009:adverse effects*; D011241:Prednisone / Q000008:administration & dosage / Q000627:therapeutic use*; D016037:Single-Blind Method; D013183:Sputum / Q000166:cytology / Q000201:enzymology; D016896:Treatment Outcome
D005938:Glucocorticoids; D010083:Oxidants, Photochemical; D010126:Ozone; D019272:Leukocyte Elastase; D011241:Prednisone