Introduction: Cystic fibrosis (CF) is an autosomal recessive disorder. Although it is considered as an epithelial disease due to impaired chloride transport, its pathogenesis is not clear. CF is classified as a syndrome with congenital defects of phagocyte in recent human inborn errors of immunity phenotypic classification. Neutrophils are the most effective cells in the eradication of bacterial infections such as Pseudomonas aeruginosa. The aim of this study was to investigate the phagocyte functions in pseudomonas colonized cystic fibrosis patients. Material-Method: A total number of 26 Pseudomonas colonized cystic fibrosis patients and 21 healthy controls (sex and age matched) were included in the study. Absolute neutrophil counts(ANC), immunoglobulin values (Ig), Migratest to evaluate chemotaxis in neutrophils and monocytes, CD11A/CD18/CD15 S (β2 integrin) adhesion molecules, Phagoburst test for intracellular bacterial killing were analyzed by flow cytometer. Results:  Absolute neutrophil counts (ANC), CD15S expression on neutrophils and IgG, IgA and IgM levels were higher in CF patients than control group (p<0.01, 0,018). The neutrophils oxidative burst activity and chemotactic ability of CF patients did not differ from that of controls. Patients with Allergic Bronchopulmonary Aspergillosis (ABPA) and with a mutation of 2183AA>G had significantly lower chemotaxis index than the others (respectively p:0.01, p:0.01). Conclusion: Our results from a small group of patients does not support impaired functions such as migration and phagocytosis of neutrophils in patients with CF. Further studies involving more CF patients are needed to make a definitive interpretation.

Objective: To determine whether high-flow nasal cannula oxygen (HFNCO) provided enhanced respiratory support in bronchiolitis than low-flow oxygen (LFO). Methods: We conducted a prospective, randomized controlled trial in children between 1-24 months diagnosed with moderate-to-severe bronchiolitis requiring oxygen therapy. Participants received LFO via face mask (6-10 L/min) or HFNCO (2 L*kg/min). Primary outcomes were the time that heart rate (HR) and respiratory rate (RR) return to their normal range for age and the time that baseline clinical respiratory score (CRS) regress to a lower severity score. Secondary outcomes were changes in HR, RR, and CRS over time, length of stay (LOS), duration of oxygen requirement, treatment failure, and adverse event (AE). Results: Eighty-seven children were enrolled (48 in LFO; 39 in HFNCO). The time that HR and RR baseline values reached their normal range for age was shorter in HFNCO therapy (2.0h [1.0-4.0] vs. 12.0h [2.0-24.0] and 4.0 h [2.0-12.0] vs. 24.0 h [4.0-48.0], respectively; P< .001); additionally, the improvement in CRS emerged more quickly in children treated with HFNCO (2.0 h [1.0-4.0] vs. 4.0 h [2.0-24.0]; P = .003). While the duration of oxygen requirement (19.0 h [4.0-30.0] vs. 29.5 h [14.0-45.7]; P = .009) and treatment failure (3% vs. 21%) was statistically lower in children who received HFNCO, there were no differences in LOS and AE between groups. Conclusion: HFNCO may provide enhanced respiratory support with a notable improvement in HR, RR, and CRS than LFO. Comprehensive studies are needed to assess the clinical efficacy of HFNCO therapy.

Objective: To determine whether viral coinfection is a risk for severe lower respiratory tract infection (LRTI). Working Hypothesis: Children with viral coinfection had a higher risk for admission to the intensive care unit (ICU) than those with a single virus infection. Study Design: Retrospective, observational study for ten years. Patient-Subject Selection: Children between 1-60 months of age hospitalized with LRTI. Methodology: We defined severe LRTI as admission to the ICU for high-flow nasal cannula oxygen/bilevel positive airway pressure/invasive ventilation and assessed demographic and laboratory data with potential risk factors from the patients’ medical records. Results: Of 2115 children hospitalized with LRTI, 562 had severe, and 1553 had mild disease. Viral coinfection was present in 28.3% of all patients, and those with viral coinfection were at a higher risk of severe LRTI than those with a single virus infection (43.8% vs. 22.7%; aOR, 3.44; 95% CI, 2.74-4.53). Respiratory syncytial virus (RSV) and rhinovirus (except for between 25-60 months) coinfections were associated with severe LRTI in all ages, whereas parainfluenza virus-3 (PIV3; 7-24 months) and bocavirus (7-12 months) coinfections led to severe LRTI in early childhood. Moreover, influenza-A coinfection caused severe LRTI in children between 7-12 and 25-60 months. Other risk factors included young age, prematurity, history of atopy, exposure to tobacco smoke, underlying condition, neutrophilia, lymphopenia, and high CRP value. Conclusion: Children with viral coinfection, particularly with rhinovirus, RSV, influenza-A, PIV3, and bocavirus, may be followed closely regarding the clinical changes.