Inflammation and corticosteroid responsiveness in ex-, current- and never-smoking asthmatics.
BACKGROUND
It has been suggested that smoking asthmatics benefit less from corticosteroid treatment than never-smoking asthmatics. We investigated differences in blood and sputum inflammatory profiles between ex-, current-, and never-smokers and assessed their ICS treatment response after 2-week and 1-year treatment.


METHODS
We analyzed FEV1, PC20 methacholine and PC20 AMP, (differential) cell counts in sputum and blood in ex-, current- and never-smokers at baseline (n=114), after 2-week treatment with fluticasone 500 or 2000 μg/day (n=76) and after 1-year treatment with fluticasone 500 μg/day or a variable dose of fluticasone based on a self-management plan (n=64).


RESULTS
A total of 114 patients were included (29 ex-, 30 current- and 55 never-smokers. At baseline, ex- and current-smokers had less eosinophils in sputum and blood than never-smokers. Blood neutrophil counts were higher in current- than in never-smokers. A higher number of cigarettes smoked daily was associated with lower blood and sputum eosinophils. After 2-week ICS treatment, FEV1 %predicted improved less in current-smokers than never-smokers (2.4% versus 8.1%, p=0.010) and ex-smokers tended to improve less than never-smokers (4.1%, p=0.067). In contrast, no differences in ICS treatment response in lung function or inflammatory cells were found between the three groups after 1 year.


CONCLUSIONS
Ex- and current-smokers have less eosinophils and more neutrophils in their sputum and blood than never-smokers. Although ex- and current-smokers have a reduced short-term corticosteroid treatment response, we did not find a difference in their long-term treatment response.
Department of Pulmonary Diseases, University Medical Center Groningen, Groningen, Netherlands. m.van.den.berge@umcg.nl.
Eef D
ED
Telenga
Huib A M
HA
Kerstjens
Nick H T
NH
Ten Hacken
Dirkje S
DS
Postma
Maarten
M
van den Berge
D000328:Adult; D000730:Androstadienes / Q000627:therapeutic use*; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology*; D015415:Biomarkers / Q000378:metabolism; D001985:Bronchial Provocation Tests; D004804:Eosinophils / Q000378:metabolism; D005260:Female; D000068298:Fluticasone; D005541:Forced Expiratory Volume; D006801:Humans; D007249:Inflammation / Q000473:pathology / Q000503:physiopathology*; D007958:Leukocyte Count; D008297:Male; D009504:Neutrophils / Q000378:metabolism; D012907:Smoking / Q000473:pathology / Q000503:physiopathology*; D016540:Smoking Cessation; D013183:Sputum / Q000166:cytology
D000730:Androstadienes; D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D000068298:Fluticasone