Background: Respiratory tract infection in infancy can cause symptomatic wheezing or asthma later in childhood. Eosinophil-derived neurotoxin (EDN), a single-chain polypeptide with a molecular mass of 18.6 kDa, has been proposed to play a role in the development of recurrent wheezing and asthma; however, this fact remains unclear. Therefore, this study aimed to determine whether EDN is a risk factor for recurrent wheezing and asthma in pediatric patients following respiratory tract infection. Method: From October 2021 to March 2022, we tracked children hospitalized for respiratory tract infections at the Chengdu Women’s and Children’s Central Hospital. All patients underwent medical history collection, EDN testing, and induced sputum testing and were followed up at 6 months and 1 year post-discharge. Multifactor analysis was subsequently conducted using stepwise logistic regression analysis. Results: A total of 183 participants were enrolled in this study. Statistical analyses revealed that elevated EDN levels increased the risk of asthma following respiratory infection in young children. Children with a history of allergies or allergic rhinitis further exhibited elevated EDN levels. Conclusion: EDN may be a useful biomarker to predict the development of asthma following respiratory tract infections in infants and could be used as a useful screening tool for allergic diseases, particularly allergic rhinitis.

Objective: To address the effectiveness and safety of early airway utilization of budesonide and surfactant for BPD prevention in premature infants with RDS. Methods: PubMed, Web of Science, EMBASE, Cochrane Library, Wanfang, CQ VIP and China National Knowledge Infrastructure databases were searched from the inception to May 2021. Stata 16.0 software was used for statistical analysis. Results: This meta-analysis suggested that early combined utilization of budesonide and surfactant by airway tended to have a superiority on BPD incidence (RR=0.63;95%CI:0.54～0.73, P<0.001), mortality (RR=0.63;95%CI:0.43～0.94, P=0.022) and the composite outcome of BPD or mortality (RR=0.59;95%CI:0.49～0.70, P<0.001), the reuse incidence of surfactant (RR=0.54; 95%CI:0.45～0.65, P<0.001), the duration of assisted ventilation (SMD=-1.14;95%CI: -1.58 ～ -0.70, P<0.001), invasive ventilation (SMD=-1.33;95%CI: -1.76～-0.90, P<0.001), and hospital stays (SMD=-1.20;95%CI: -1.88～-0.51, P=0.001) in preterm infants with RDS. And these benefits were not associated with increased adverse outcomes. Furthermore, a decreased incidence of PDA (RR=0.80; 95%CI:0.64～0.99, P=0.041) was found in test group. Subgroup analysis based on budesonide delivery methods (inhalation or intratracheal instillation) indicated that the decrease of mortality (RR=0.62;95%CI:0.41～0.95, P=0.026), duration of assisted ventilation (SMD=-0.95;95%CI: -1.30～-0.61, P<0.001) and hospital stays (SMD=-1.38;95%CI: -2.33～-0.43, P=0.004) were mainly in budesonide intratracheal instillation subgroup. Conclusions: This meta-analysis suggested that early combined utilization of budesonide and surfactant by airway might be an effective and safe clinical practice for BPD prevention in premature infants with RDS, especially when budesonide was delivered by intratracheal instillation.