The relationship between airway inflammation typing and asthma status and its response to inhaled corticosteroids treatment in children with mild or moderate asthma / 临床儿科杂志

ABSTRACT

Objective To evaluate the relationship between airway inflammation before treatment and asthma status and response to inhaled corticosteroids treatment in children with mild or moderate asthma. Methods Eighty-seven children diagnosed with mild or moderate asthma were enrolled as study group, 20 healthy children as control group. Sputum induction, cellular differential count, and the assaying of mediators in sputum supernatant were performed before treatment with corticosteroids. Eosinophil cationic protein were measured by enzyme-linked fluorescent assay, interleukin-8 and transforming growth factor-β_1 (TGF-β_1) were measured by enzyme linked immunosorbent assay. Pulmonary function tests were performed for small airway function on the baseline and methacholine bronchial provocation tests were performed to screen airway hyperresponsiveness. SPSS13.0 software was used to analyze the data. Results (1) Among the 87 patients, 64 patients were studied as eosinophil asthma (EA) group, 23 patients as non-eosinophil asthma (NEA) group according to the ratio of eosinophils in sputum. The percentages of inflammatory cells and level of ECP, IL-8 were of significant difference between the two groups (P < 0.05), other indexes as FEV_1% pred, PEF% pred, moderate-severe AHR%. small airway function were also of significant difference between the two groups (P < 0.05). (2) Patients in EA group showed significant improvement in pulmonary function, bronchial hyperresponsiveness and small airway function after treatment with inhaled corticosteroids compared with NEA group. (3) Multiple stepwise regression analysis showed that among the different baseline variants considered only baseline FEVl%pred, sputum eosinophil percentages (EOS%), sputum TGF-β_1 significantly correlated with the response to inhaled cortieosteroids, moreover, sputum eosinophil percentages had the closest correlation (β= 0.583, t = 6.214, P < 0.05). Conclusions There were different patterns of airways inflammation in children with mild or moderate asthma. Sputum eosinophilia was associated with asthma status. Low sputum eosinophils, low FEV_1%pred, high sputum TGF-β_1 before treatment predict poor response to treatment with inhaled corticosteroids. Evaluation of those baseline indexes may be helpful to an individualized therapeutic regime.