Dysfunction of neutrophils in patients with cystic fibrosis (CF) is best characterized in bronchoalveolar lavage (BAL), whereas peripheral blood neutrophils are less examined, and the results are contradictory, especially in younger populations. Therefore, this work aimed to study functional and phenotypic changes in circulating neutrophils in children with CF. The study included 19 CF children (5–17 years) and 14 corresponding age-matched healthy children. Isolated neutrophils were cultured either alone or with different stimuli. Several functions were studied: apoptosis, NET-osis, phagocytosis, and production of reactive oxygen species (ROS), neutrophil elastase (NE), and 11 cytokines. In addition, the expression of 20 molecules involved in different functions of neutrophils was evaluated by using flow cytometry. CF neutrophils showed reduced apoptosis and lower production of NE and IL-18 compared to the healthy controls, whereas IL-8 was augmented. All of these functions were further potentiated after neutrophil stimulation, which included higher ROS production and the up-regulation of CD11b and IL-10 expression. NET-osis was higher only when neutrophils from moderate–severe CF were treated with Pseudomonas aeruginosa, and the process correlated with forced expiratory volume in the first second (FEV1). Phagocytosis was not significantly changed. In conclusion, circulating neutrophils from children with CF showed fewer impaired changes in phenotype than in function. Functional abnormalities, which were already present at the baseline levels in neutrophils, depended on the type of stimuli that mimicked different activation states of these cells at the site of infection.

Asthma is a syndrome characterized by chronic inflammation of the airways, which represents one of the key elements of the disease. Over the past decade, significant progress has been made in understanding the pathophysiology of severe asthma in children. This led to the development of biological drugs.Objective: to evaluate the therapeutic effects of omalizumab during one year of treatment in patients with persistent severe asthma..Materials and methods: 30 children aged 8 to 18 with persistent moderate and severe asthma were included in the study. The therapeutic effects of Omalizumab on lung functions, fraction of exhaled nitric oxide and body mass index were evaluated.Results: Forced expiratory volume in 1 second and forced expiratory flow FEF 25-75 show improvement trends after the administration of Omalizumab. The decrease in body mass index was statistically significant after therapy.Conclusion: Omalizumab could have a modifying effect on long-term disease progression in children with severe asthma.