Smoking Affects Eotaxin Levels in Asthma Patients

Abstract

Background. Chronic airway inflammation is most important pathological finding in asthma. Cigarette smoking may modify type of inflammation as well as may influence disease severity and response to the treatment. Objective. Thus the aim of this study was to investigate whether cigarette smoking may have an influence on the levels of eotaxin-1, eotaxin-2, eotaxin-3 and IL-5 in patients with stable mild/moderate asthma. Methods. 45 steroid naive asthmatics (mean age: 55.2 ± 2.2 yrs) and 23 “healthy” smokers and non-smokers control subjects (mean age: 54.4 ± 9.7 yrs) were investigated. Asthmatics were divided into two subgroups according to their smoking histories: asthmatic smokers (n = 19) who currently smoke and have a history of > 10 pack-years and asthmatic never-smokers (n = 26). BAL and induced sputum were performed. Cytospins of induced sputum and BAL were stained with May-Grünwald-Giemsa for differential cell counts. Eotaxin-1, eotaxin-2, eotaxin-3 and IL-5 concentrations in serum, sputum and BAL supernatant was measured using a commercial ELISA kit. Results. In sputum supernatant from asthma smokers was significantly higher concentration of eotaxin-1 than in non-smokers asthmatics (203.4 ± 10.0 vs. 140.2 ± 9.5 respectively, p < 0.05). In non-smokers asthma patients levels of BAL eotaxin-1 strongly related to percent and absolute numbers of BAL eosinophils and neutrophils (Rs = 0.737 and Rs = 0.514 respectively, p < 0.05). The number and percent of sputum neutrophils and eosinophils, obtained from smokers asthmatics, significantly correlated with eotaxin-2 concentration in sputum supernatant (Rs = 0.58 and Rs = 0.75 respectively, p < 0.05). IL-5 levels in the serum and sputum from asthmatic never-smokers were significantly higher than they were from asthmatic smokers and “healthy” smokers. Asthmatic never-smokers showed a significantly higher amount of IL-5 in serum and sputum than the asthmatic smokers showed. Conclusions. This study showed the elevated levels of sputum eotaxin-1 as well as serum, sputum and BAL eotaxin-2 in asthmatic smokers without a significant increase of eosinophils compared to asthmatic never-smokers. The eotaxin concentrations were related not only with number of eosinophils but also with the number of neutrophils in all the studied tissue compartments. The data herein permits a suggestion that smoking may influence change in asthmatic airway inflammation by stimulating the production of eotaxins.

Keywords:

• asthma
• smoking
• eotaxin-1
• eotaxin-2
• eotaxin-3
• IL-5