Características e variação do fenótipo inflamatório do escarro induzido em crianças e adolescentes com asma grave resistente à terapia

Abstract

Introduction: Asthma is a global health problem, with a high prevalence, especially in the child population. Of the children with this disease, about 5-10% do not respond adequately to the drug treatment, presenting no disease control, even with the best optimization of the clinical management, and then classified as severe therapy-resistant asthma (STRA). There are few clinical studies with pediatric patients with STRA. Objective: to evaluate the lower airway inflammation profile and pulmonary function characteristics in children and adolescents with STRA, compared to children with mild to moderate asthma (MMA). Methods: Patients aged 6 to 18 years, with a diagnosis of STRA (n = 28), followed for more than three months in a reference center, regardless of the prescribed treatment, and with MMA (n = 75) were selected. a transversal study in public schools of the same city were selected. The classification of patients, STRA or MMA, followed internationally established criteria. Disease control, lung function tests, and inflammation in induced sputum were evaluated. Results: patients with STRA did not present an inflammatory pattern different from those with MMA, but the STRA group showed a significantly higher frequency of sputum exams without inflammation (p = 0.003). An inverse correlation was found between FEV1 (r = -0.83, p = 0.0007), FVC (r = -0.75, p = 0.004) and FEF25-75 (r = -0.88, p = 0.0001) and the absolute number of neutrophils when analyzed (STRA and MMA) with abnormal pulmonary function. Finally, there was a change in the inflammatory pattern of patients with STRA who underwent two sputum exams in 9/16 (56%) of the cases. Conclusion: Our findings show that pediatric patients with STRA do not present a different inflammatory pattern from patients with milder asthma, suggest that neutrophilic inflammation may be involved in worsening lung function, and that most patients with severe asthma modify the inflammation pattern of the lower airways.