Clinical-instrumental, cytological and inflammatory markers of airway remodeling in children with bronchial asthma

Abstract

Purpose - to investigate the clinical-instrumental, cytological and inflammatory characteristics of the disease in children with bronchial asthma, taking into account the content of the remodeling marker matrix metalloproteinase-9 (MMP-9) in the sputum to optimize the timely detection of structural remodeling of the bronchi. Materials and methods. A cohort of 99 children with BA was examined by the method of random sampling in the conditions of the Pulmonary Allergology Department of the RMCE CRCCH. All children underwent a complex clinical and paraclinical examination with the determination of the cytological composition of sputum, the determination of bronchial hyperreactivity and their hypersensitivity in a sample with serial dilution of histamine, the study of the concentration of metabolites of nitrogen monoxide in peripheral blood and condensate of pulmonary expiratory air. Two clinical groups were formed. The Group I included 55 patients in whom the content of MMP-9 in the sputum supernatant did not reach the level of 5.4 ng/ml, and the II group was formed by 44 patients with MMP-9 content ≥5.4 ng/ml. The main clinical characteristics of the observation groups were comparable. Results. It was established that the risk of a clinically more severe exacerbation of the disease is twice as high in children with an increased content of MMP-9 in the sputum (relative risk - 1.4, odds ratio - 2.0) with the preservation of this trend during 5 days of inpatient treatment. The work also shows that in patients with an increased content of MMP-9 in sputum, the concentration of FeNO more than 22.0 μmol/l occurs twice as often as in the first clinical group (pφ<0.05). This finding reflects the association of the processes of allergic inflammation of the respiratory tract and their remodeling. The results of the PC20H bronchoprovocation test indicate statistically significantly lower levels of the provocation dose and provocation concentration of histamine, which corresponds to significant bronchial hypersensitivity, the chances of which increase against the background of the accumulation of MMP-9 in sputum: 27.7 times for PC20H (FEV1) <3.7mg/ml and 48.8 times for PD20H (FEV1) <0.8mg. Conclusions. An increase in the content of MMP-9 in the supernatant fluid of sputum was associated with a more severe course of exacerbations of bronchial asthma in children, an increase in the content of metabolites of nitrogen monoxide in the blood and lung expiratory air, more pronounced signs of bronchial hypersensitivity. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.