[IL-25  derived  from epithelial cells has the potential to promote airway remodeling in asthma].
OBJECTIVE
To explore the role    of interleukin-25(IL-25) in the pathogenesis of eosinophilic asthma (EA) and non-eosinophilic asthma (NEA) through detecting  its expression in serum,  induced sputum and bronchial epithelial mucosa of asthmatic patients.


METHODS
Serum and induced sputum   were collected   from 55 untreated asthmatic patients and 27 healthy control subjects.  The asthmatic patients were divided into EA and NEA groups  according to sputum eosinophils(EOS) percentage (3%  as a dividing point).    The level of IL-25 in serum and induced spntum was determined  by ELISA; the expression  of IL-25 in bronchial epithelium was quantified by immunohistochemistry   in biopsied specimens from 10 cases of EA, 10 NEA and 10 controls.  Basement membrane thickness as an important index of airway remodeling was  detected by  HE staining.


RESULTS
Compared with healthy control subjects,  the lung function was impaired in patients with EA and NEA. ELISA results showed that the levels of IL-25 in the serum and induced sputum of asthmatic patients were significantly higher than those in  healthy subjects (P<0.05). But there were no statistic differences between EA and NEA patients (P>0.05). The immunohistochemical results indicated that the  expression of IL-25 was higher  in asthmatic bronchial epithelium   than in control ones.   HE staining showed that the basement membrane thickness    increased in EA and NEA patients(P<0.05). Correlation analysis showed that the levels  of IL-25 in serum and induced sputum were   positively correlated with the average thickness of basement membrane in asthmatic patients.


CONCLUSIONS
IL-25 secreted from epithelial cells has the potential to promote airway remodeling in asthma.  EOS has  nothing to do with the thickness of basement membrane,  and    it may not be necessary for airway remodeling in asthma.
Department of Respiratory Medicine, Shandong University, Jinan, China. liufen0102@163.com
Fen
F
Liu
Jin-xiang
JX
Wu
Ji-ping
JP
Zhao
Hong-jia
HJ
Li
Wen
W
Liu
Wen-xiang
WX
Bi
Liang
L
Dong
D000328:Adult; D056151:Airway Remodeling / Q000276:immunology*; D001249:Asthma / Q000276:immunology* / Q000473:pathology; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D020381:Interleukin-17 / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020545:Respiratory Mucosa / Q000276:immunology / Q000378:metabolism / Q000473:pathology
D020381:Interleukin-17