Abstract: Abstract: Objective To investigate the expression and clinical significance of neutrophil S100A8/A9 in induced sputum in children with bronchial asthma. Methods A total of 108 cases of bronchial asthma patients in the Fourth Affiliated Hospital of Nanchang University were involved in the study form October 2014 to October 2015. According to the severity of the disease, the patients were divided into mild group (n=40), moderate group (n=36) and severe group (n=32).Twenty health children were taken as control group at the same period. All the patients were treated with budesonide aerosol for three months, and the control group was received aerosol inhalation for normal saline (NS). The ratio of forced expiratory volume in one second and forced vital capacity (FEV1/FVC, FEV1%) were used to evaluate the pulmonary function in two groups. The asthma control questionnaire (AcQ- 5) score was used to estimate the asthma control effects. The expression level of neutrophil S100A8/A9 mRNA in induced sputum was detected by real-time PCR. The correlation of S100A8/A9 mRNA, AcQ-5 score and FEV1% was analyzed. Results Before the treatment, the FEV1% decreased, while the AcQ-5 score and express level of S100A8/A9 mRNA significantly increased with the severity of disease (all P < 0.01). Three months after treatment, asthma was completely controlled in 60 patients, partial controlled in 31 cases and uncontrolled in 17 cases.With the improvement of the therapeutic efficacy, the FEV1% significantly decreased, while the express level of S100A8/A9 mRNA significantly increased (all P < 0.01). The express level of S100A8/A9 mRNA in induced sputum neutrophils wasnegatively correlated with FEV1% (r=-0.327 and -0.406 respectively, P < 0.05), which was positively correlated with ACQ-5 score (r=0.704 and 0.817, P < 0.05). Conclusion The level of S100A8/A9 expression in induced sputum neutrophil is positively correlated with the severity of asthma, which can be used as clinical indicators of the severity and the efficacy of asthma.

Key words: asthma, bronchial asthma, sputum, neutrophil infiltration, S100A8/A9, asthma control questionnaire