September 24, 2013

Inflammation and corticosteroid responsiveness in ex-, current- and never-smoking asthmatics

Open Access
Research article


Eef D TelengaHuib A KerstjensNick H ten HackenDirkje S Postma and Maarten van den Berge
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BMC Pulmonary Medicine 2013, 13:58 doi:10.1186/1471-2466-13-58
Published: 22 September 2013

Abstract (provisional)

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 mug/day (n=76) and after 1-year treatment with fluticasone 500 mug/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.

The complete article is available as a provisional PDF. The fully formatted PDF and HTML versions are in production.

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