Inflammatory Indices in Predicting the Failure of Inhaled Corticosteroids Reduction in Young Participants With Asthma

A prospective, observational, interventional, single-blind study (blinded for a clinician in the field of inflammatory parameters). The aim of the study is evaluation of the usefulness of induced sputum eosinophilia and other inflammatory indices [exhaled nitric oxide (NO), exhaled breath temperature, bronchial hyperresponsiveness] in predicting the failure of treatment reduction with inhaled corticosteroids (ICS) in stable asthma in children and adolescents. In participants with a stable course of the asthma (confirmed in the run -in period), every 3 months the dose of ICS is halved (according to GINA guidelines) until the control is lost or the lowest daily ICS dose is reached (200 mcg, calculated as budesonide equivalent). Throughout the treatment reduction period, the participants run an observation card (clinical symptoms) and peak expiratory flow rate (PEFR) measurements. Clinical evaluation is performed every month, with spirometry, exhaled NO and exhaled breath temperature measurements. Before the reduction and then one month after the change of treatment, the hyperresponsiveness measurement is carried out with the sputum induction (combined method using hypertonic saline), and 2 months after the change of treatment with the exercise challenge test. In the case of loss of asthma control, beta-mimetic will be administered (temporarily) and return to dose of ICS before reduction or further increase of treatment is planned. In severe asthma exacerbations, oral steroids will be considered. The study is observational: treatment is modified according to GINA guidelines based on clinical data as part of routine medical care. Only difference compared do standard care is supplementary inflammation evaluation (exhaled NO, sputum eosinophilia, bronchial hyperreactivity).