Cystic fibrosis (CF) is characterized by neutrophil-driven airway inflammation and acute respiratory events (AREs) that contribute to progressive lung damage. AREs are clinically heterogeneous and often occur without measurable changes in lung function. This study aimed to evaluate the utility of molecular airway inflammatory markers for detecting AREs in school-age children with CF. We performed a secondary analysis of a prospective observational study of children with CF (ages 6.7–16.8 years) followed for two years. Sputum samples were collected from 50 participants during stable visits and AREs. Concentrations of 14 inflammatory cytokines were measured using ELISA and multiplex assays. Associations with lung function (ppFEV₁ and lung clearance index [LCI]) and time to next ARE were assessed. A total of 179 sputum samples were analyzed, including 64 collected during AREs. Calprotectin, interleukin-8 (IL-8), and IL-1β were increased during AREs compared with stable visits, although concentrations frequently remained within ranges observed at stable visits. Other cytokines, including GM-CSF, IL-17A, IL-1α, TNF-α, and SPLUNC-1, were predictive of shorter time to subsequent AREs. No biomarker correlated with lung function measures. These findings indicate that airway inflammatory cytokine changes are associated with clinically diagnosed AREs but not with pulmonary function, supporting their potential role as complementary biomarkers in CF care.

Background: Necrotizing pneumonia (NP) is a severe complication of pediatric community-acquired pneumonia, associated with prolonged hospitalization and morbidity. Early predictors remain poorly defined. We aimed to identify clinical and laboratory factors present at admission that predict NP by comparing children with NP to those with non-complicated pneumonia (NCP), and to evaluate outcomes. Methods: A retrospective cohort study at Hadassah Medical Center included all children diagnosed with NP between January 2010 and December 2024. Age-matched children hospitalized with NCP served as controls. Demographic, clinical, laboratory, imaging, and treatment data were extracted. Univariate analyses were followed by multivariable logistic regression to identify independent predictors. Results: Sixty-nine children with NP were compared with 456 with NCP. NP patients had longer duration of fever and cough before admission and poorer general appearance. NP was associated with higher inflammatory burden, including higher C-reactive protein (CRP) levels (25.9 vs 11.0 mg/L, p<0.001), higher neutrophil percentage, thrombocytosis, anemia, and hypoalbuminemia. In multivariable analysis (n=427), independent predictors of NP were prior antibiotic treatment (OR 3.39, 95% CI 1.55–7.42), longer pre-admission fever (OR 1.13/day, 95% CI 1.00–1.27), higher CRP (OR 1.10/mg/L, 95% CI 1.07–1.13), and poor general appearance, while good appearance was protective (OR 0.14, 95% CI 0.04–0.50). Conclusions: NP is associated with a distinct early clinical and inflammatory profile. Prolonged fever, prior antibiotic exposure, elevated CRP, and poor general appearance independently predict NP, supporting early risk stratification and closer monitoring.