Clinical characteristics of eosinophilic and noneosinophilic asthma in children

Aim Asthma is a heterogeneous and complex chronic inflammatory disease of the airways. Asthma can be classified as eosinophilic asthma (EA) or noneosinophilic asthma (NEA). We investigated whether children with EA manifest different clinical characteristics than those with NEA. Methods We enrolled 288 steroid-naive asthmatic children and classified them, based on the cell counts in induced sputum, into EA (158 children) and NEA (89 children) groups. Results No significant differences were observed between the groups with regard to age, sex, family history of atopy, secondary smoking or asthma exacerbations. Moderate-to-severe asthma was more frequent in the EA group than in the NEA group. Blood eosinophil counts and serum eosinophil cationic protein were higher in EA patients than in NEA patients. The forced expiratory volume in 1 sec was lower in children with EA than in those with NEA (% of predicted value, 88.6 +/- 18.5 vs. 93.6 +/- 15.6, p < 0.05). The sputum eosinophil (in EA) and neutrophil (in NEA) counts increased with increasing asthma severity. Conclusion Airway inflammation, especially eosinophilic inflammation, was associated with asthma severity and reduced pulmonary function in children.