Bronchopulmonary Dysplasia: Chronic Lung Disease of Infancy and Long-Term Pulmonary Outcomes

Temporal Dynamics of Oxidative Stress and Inflammation in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is the most common lung complication of prematurity. Despite extensive research, our understanding of its pathophysiology remains limited, as reflected by the stable prevalence of BPD. Prematurity is the primary risk factor for BPD, with oxidative stress (OS) and inflammation playing significant roles and being closely linked to premature birth. Understanding the interplay and temporal relationship between OS and inflammation is crucial for developing new treatments for BPD. Animal studies suggest that OS and inflammation can exacerbate each other. Clinical trials focusing solely on antioxidants or anti-inflammatory therapies have been unsuccessful. In contrast, vitamin A and caffeine, with antioxidant and anti-inflammatory properties, have shown some efficacy, reducing BPD by about 10%. However, more than one-third of very preterm infants still suffer from BPD. New therapeutic agents are needed. A novel tripeptide, N-acetyl-lysyltyrosylcysteine amide (KYC), is a reversible myeloperoxidase inhibitor and a systems pharmacology agent. It reduces BPD severity by inhibiting MPO, enhancing antioxidative proteins, and alleviating endoplasmic reticulum stress and cellular senescence in a hyperoxia rat model. KYC represents a promising new approach to BPD treatment.

Identification and Validation of Oxidative Stress-Related Biomarkers for Bronchopulmonary Dysplasia

The objective of this study was to identify and characterize oxidative stress (OS)-related biomarkers in bronchopulmonary dysplasia (BPD) through a combination of bioinformatics analyses and wet experiments. The study utilized the Gene Expression Omnibus database to obtain the mRNA expression profile dataset GSE32472. Differential expression analysis and functional enrichment analysis were employed to investigate the role of OS-related genes in BPD. Gene Ontology Function Enrichment Analysis and Gene Set Enrichment Analysis were conducted to understand the mechanisms behind the signature. Protein-protein interaction analysis to identify hub genes in BPD, and predictions were made for microRNAs (miRNAs), transcription factors (TFs), and potential medications targeting these genes. CIBERSORT was utilized to investigate the correlation between hub genes and the infiltration of immune cells. Hub genes were ultimately determined and confirmed using expression analysis, correlation analysis, receiver operating characteristic (ROC) analysis, and quantitative real-time PCR (qRT-PCR). A novel OS-related gene signature (ARG1, CSF3R, IL1R1, IL1R2, MMP9, RETN, S100A12, and SOCS3) was constructed for the prediction of BPD. We identified 18 miRNAs, 14 TFs, and 30 potential medications targeting these genes. ROC analysis further validated that these genes could diagnose BPD with high specificity and sensitivity. The qRT-PCR revealed that IL1R1 and ARG1 were highly expressed in the lung tissue of the model group, while the expressions of RETN, SOCS3, IL1R2, and MMP9 were decreased. This study demonstrated that ARG1, CSF3R, IL1R1, IL1R2, MMP9, RETN, S100A12, and SOCS3 may serve as potential diagnostic biomarkers in BPD. Furthermore, a significant association between IL1R1 and the pathogenesis of BPD is observed.

Lung ultrasound score for prediction of bronchopulmonary dysplasia in newborns: A meta-analysis

BACKGROUND

Bronchopulmonary dysplasia (BPD) ranks among preterm infants' most common and severe respiratory diseases. Lung ultrasound scores (LUS) play a vital role in predicting early BPD and guiding treatment and intervention strategies for affected patients.

OBJECTIVE

Performed a meta-analysis to assess the diagnostic LUS for newborns with BPD.

METHODS

Online electronic databases such as MEDLINE, CINAHL, the Cochrane Library, and Web of Science were used to retrieve relevant research until May 2023. A total of 117 literatures were collected, and ten eligible articles were selected for meta-analysis.

RESULTS

Meta-analysis was performed on 10 studies (1274 neonates). LUS at 7 days after birth (7 days of life, DOL 7) showed good diagnostic accuracy for any type of BPD, moderate and severe BPD. DOL 7 was more accurate in predicting all types of BPD (AUC = 0.87, sensitivity = 0.75, specificity = 0.83) than moderate and severe BPD (AUC = 0.80, sensitivity = 0.69, specificity = 0.79). There was no statistical significance between DOL 7 and DOL 14 in their accuracy for predicting all types of BPD (difference in AUC = 0.04, p= 0.068). There was no notable distinction between DOL 7 and DOL 14 in their accuracy for predicting moderate and severe BPD (difference in AUC =-0.04, p= 0.104).

CONCLUSIONS

The diagnostic efficacy of LUS on DOL 7 in predicting the occurrence of all types of BDP and moderate-severe BPD is determined. This will facilitate rapid and accurate detection and timely treatment, thereby reducing the risk of neonatal mortality and sequelae.

Pulse oximetry in pediatric care: Balancing advantages and limitations

BACKGROUND

Pulse oximetry has become a cornerstone technology in healthcare, providing non-invasive monitoring of oxygen saturation levels and pulse rate. Despite its widespread use, the technology has inherent limitations and challenges that must be addressed to ensure accurate and reliable patient care.

AIM

To comprehensively evaluate the advantages, limitations, and challenges of pulse oximetry in clinical practice, as well as to propose recommendations for optimizing its use.

METHODS

A systematic literature review was conducted to identify studies related to pulse oximetry and its applications in various clinical settings. Relevant articles were selected based on predefined inclusion and exclusion criteria, and data were synthesized to provide a comprehensive overview of the topic.

RESULTS

Pulse oximetry offers numerous advantages, including non-invasiveness, real-time feedback, portability, and cost-effectiveness. However, several limitations and challenges were identified, including motion artifacts, poor peripheral perfusion, ambient light interference, and patient-specific factors such as skin pigmentation and hemoglobin variants. Recommendations for optimizing pulse oximetry use include technological advancements, education and training initiatives, quality assurance protocols, and interdisciplinary collaboration.

CONCLUSION

Pulse oximetry is crucial in modern healthcare, offering invaluable insights into patients’ oxygenation status. Despite its limitations, pulse oximetry remains an indispensable tool for monitoring patients in diverse clinical settings. By implementing the recommendations outlined in this review, healthcare providers can enhance the effectiveness, accessibility, and safety of pulse oximetry monitoring, ultimately improving patient outcomes and quality of care.

Stem cell-derived extracellular vesicles: a potential intervention for Bronchopulmonary Dysplasia

Despite advances in neonatal care, the incidence of Bronchopulmonary Dysplasia (BPD) remains high among extreme preterm infants. The pathogenesis of BPD is multifactorial, with inflammation playing a central role. There is strong evidence that stem cell therapy reduces inflammatory changes and restores normal lung morphology in animal models of hyperoxia-induced lung injury. These therapeutic effects occur without significant engraftment of the stem cells in the host lung, suggesting more of a paracrine mechanism mediated by their secretome. In addition, there are multiple concerns with stem cell therapy which may be alleviated by administering only the effective vesicles instead of the cells themselves. Extracellular vesicles (EVs) are cell-derived components secreted by most eukaryotic cells. They can deliver their bioactive cargo (mRNAs, microRNAs, proteins, growth factors) to recipient cells, which makes them a potential therapeutic vehicle in many diseases, including BPD. The following review will highlight recent studies that investigate the effectiveness of EVs derived from stem cells in preventing or repairing injury in the preterm lung, and the potential mechanisms of action that have been proposed. Current limitations will also be discussed as well as suggestions for advancing the field and easing the transition towards clinical translation in evolving or established BPD. IMPACT: Extracellular vesicles (EVs) derived from stem cells are a potential intervention for neonatal lung diseases. Their use might alleviate the safety concerns associated with stem cell therapy. This review highlights recent studies that investigate the effectiveness of stem cell-derived EVs in preclinical models of bronchopulmonary dysplasia. It adds to the existing literature by elaborating on the challenges associated with EV research. It also provides suggestions to advance the field and ease the transition towards clinical applications. Optimizing EV research could ultimately improve the quality of life of extreme preterm infants born at vulnerable stages of lung development.

A Comprehensive Consolidation of Data on the Relationship Between Surfactant Protein-B (SFTPB) Polymorphisms and Susceptibility to Bronchopulmonary Dysplasia

BACKGROUND

This meta-analysis aims to evaluate the potential link between common variations in the Surfactant Protein-B (SFTPB) gene and the risk of bronchopulmonary dysplasia (BPD) in preterm neonates.

METHODS

All pertinent articles published prior to February 1, 2024, in PubMed, Web of Science, EMBASE, CNKI, and Scopus databases were reviewed.

RESULTS

Nineteen case-control studies involving 1149 BPD cases and 1845 non-BPD controls, were analyzed. Combined data indicated a significant link between SFTPB -18 A > C and Intron 4 VNTR polymorphisms with increased BPD susceptibility, while the 1580 C > T polymorphism provides a protective impact on BPD initiation.

CONCLUSIONS

Pooled data indicated a significant association between SFTPB -18 A > C and Intron 4 VNTR polymorphisms with increased BPD risk, whereas the 1580 C > T polymorphism confers protection. These findings suggest a genetic susceptibility to BPD, underscoring the complex interplay of different genetic elements in its development.

Fetal origin of bronchopulmonary dysplasia: contribution of intrauterine inflammation

Bronchopulmonary dysplasia (BPD) is a common chronic lung disease in infants and the most frequent adverse outcome of premature birth, despite major efforts to minimize injury. It is thought to result from aberrant repair response triggered by either prenatal or recurrent postnatal injury to the lungs during development. Intrauterine inflammation is an important risk factor for prenatal lung injury, which is also increasingly linked to BPD. However, the specific mechanisms remain unclear. This review summarizes clinical and animal research linking intrauterine inflammation to BPD. We assess how intrauterine inflammation affects lung alveolarization and vascular development. In addition, we discuss prenatal therapeutic strategies targeting intrauterine inflammation to prevent or treat BPD.

Role of sex as a biological variable in neonatal alveolar macrophages

The lung macrophages play a crucial role in health and disease. Sexual dimorphism significantly impacts the phenotype and function of tissue-resident macrophages. The primary mechanisms responsible for sexually dimorphic outcomes in bronchopulmonary dysplasia (BPD) remain unidentified. We tested the hypothesis that biological sex plays a crucial role in the transcriptional state of alveolar macrophages, using neonatal murine hyperoxia-induced lung injury as a relevant model for human BPD. The effects of neonatal hyperoxia exposure (95 % FiO2, PND1-5: saccular stage) on the lung myeloid cells acutely after injury and during normoxic recovery were measured. Alveolar macrophages (AM) from room air- and hyperoxia exposed from male and female neonatal murine lungs were subjected to bulk-RNA Sequencing. AMs are significantly depleted in the hyperoxia-exposed lung acutely after injury, with subsequent recovery in both sexes. The transcriptome of the alveolar macrophages is impacted by neonatal hyperoxia exposure and by sex as a biological variable. Pathways related to DNA damage and interferon-signaling were positively enriched in female AMs. Metabolic pathways related to glucose and carbohydrate metabolism were positively enriched in the male AMs, while oxidative phosphorylation was negatively enriched. These pathways were shared with monocytes and airway macrophages from intubated male and female human premature neonates.

Recombinant fragment of human surfactant protein D to prevent neonatal chronic lung disease (RESPONSE): a protocol for a phase I safety trial in a tertiary neonatal unit

INTRODUCTION

Chronic respiratory morbidity from bronchopulmonary dysplasia (BPD) remains the most common complication of preterm birth and has consequences for later respiratory, cardiovascular and neurodevelopmental outcomes. The early phases of respiratory illness are characterised by rapid consumption of endogenous surfactant and slow replenishment. Exogenous surfactant is routinely administered to infants born before 28 weeks of gestation as prophylaxis. Endogenous surfactant includes four proteins, known as surfactant proteins (SPs) A, B, C and D. Current bovine-derived and porcine-derived surfactant preparations only contain SPs B and C. SP-D has a key role in lung immune homeostasis as part of the innate immune system. Laboratory studies using recombinant SP-D have demonstrated reduced inflammation, which may be a pathway to reducing the associated morbidity from BPD. RESPONSE uses a recombinant fragment of human SP D (rfhSP-D), in a phase I safety and dose-escalation trial as the first stage in determining its effect in humans.

METHODS AND ANALYSIS

This is a single-centre, dose-escalation, phase I safety study aiming to recruit 24 infants born before 30 weeks gestation with respiratory distress syndrome. In addition to routine surfactant replacement therapy, participants will receive three doses of rfhSP-D via endotracheal route at either 1 mg/kg, 2 mg/kg or 4 mg/kg. The study uses a Bayesian continual reassessment method to make dose escalation decisions. Dose-limiting events (DLE) in this trial will be graded according to the published Neonatal Adverse Event Severity Score. The primary outcome of this study is to evaluate the safety profile of rfhSP-D across each dose level based on the profile of DLE to establish the recommended phase 2 dose (RP2D) of rfhSP-D.

ETHICS AND DISSEMINATION

The RESPONSE study has received ethical approval from London-Brent NHS Research Health Authority ethics committee. Results from the study will be published in peer-reviewed journals and presented at national and international conferences.

TRIAL REGISTRATION NUMBERS

ISRCTN17083028, NCT05898633.

PROTOCOL VERSION

RESPONSE Protocol V.4.0 24th July 2024.

Role of Myeloperoxidase, Oxidative Stress, and Inflammation in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a lung complication of premature births. The leading causes of BPD are oxidative stress (OS) from oxygen treatment, infection or inflammation, and mechanical ventilation. OS activates alveolar myeloid cells with subsequent myeloperoxidase (MPO)-mediated OS. Premature human neonates lack sufficient antioxidative capacity and are susceptible to OS. Unopposed OS elicits inflammation, endoplasmic reticulum (ER) stress, and cellular senescence, culminating in a BPD phenotype. Poor nutrition, patent ductus arteriosus, and infection further aggravate OS. BPD survivors frequently suffer from reactive airway disease, neurodevelopmental deficits, and inadequate exercise performance and are prone to developing early-onset chronic obstructive pulmonary disease. Rats and mice are commonly used to study BPD, as they are born at the saccular stage, comparable to human neonates at 22-36 weeks of gestation. The alveolar stage in rats and mice starts at the postnatal age of 5 days. Because of their well-established antioxidative capacities, a higher oxygen concentration (hyperoxia, HOX) is required to elicit OS lung damage in rats and mice. Neutrophil infiltration and ER stress occur shortly after HOX, while cellular senescence is seen later. Studies have shown that MPO plays a critical role in the process. A novel tripeptide, N-acetyl-lysyltyrosylcysteine amide (KYC), a reversible MPO inhibitor, attenuates BPD effectively. In contrast, the irreversible MPO inhibitor-AZD4831-failed to provide similar efficacy. Interestingly, KYC cannot offer its effectiveness without the existence of MPO. We review the mechanisms by which this anti-MPO agent attenuates BPD.

Mitochondrial dynamics in pulmonary disease: Implications for the potential therapeutics

Mitochondria are dynamic organelles that continuously undergo fusion/fission to maintain normal cell physiological activities and energy metabolism. When mitochondrial dynamics is unbalanced, mitochondrial homeostasis is broken, thus damaging mitochondrial function. Accumulating evidence demonstrates that impairment in mitochondrial dynamics leads to lung tissue injury and pulmonary disease progression in a variety of disease models, including inflammatory responses, apoptosis, and barrier breakdown, and that the role of mitochondrial dynamics varies among pulmonary diseases. These findings suggest that modulation of mitochondrial dynamics may be considered as a valid therapeutic strategy in pulmonary diseases. In this review, we discuss the current evidence on the role of mitochondrial dynamics in pulmonary diseases, with a particular focus on its underlying mechanisms in the development of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis (PF), pulmonary arterial hypertension (PAH), lung cancer and bronchopulmonary dysplasia (BPD), and outline effective drugs targeting mitochondrial dynamics-related proteins, highlighting the great potential of targeting mitochondrial dynamics in the treatment of pulmonary disease.

Advances in the pharmacological management of bronchopulmonary dysplasia: an update of the literature

INTRODUCTION

Bronchopulmonary dysplasia (BPD) is the commonest adverse outcome of extremely prematurely born infants, and its incidence is increasing. Affected infants suffer chronic respiratory morbidity and are at risk of early onset of chronic obstructive pulmonary disease. It is, therefore, important that these infants are appropriately managed, with efficacious pharmacological treatments.

AREAS COVERED

Searches were made on Embase, PubMed, and the Cochrane database for ('treatment' or 'drug therapy/') and ('bronchopulmonary dysplasia' or 'chronic lung disease') and ('neonatology' or 'newborn' or 'prematurity' or 'baby') between 2019 and 2024. Corticosteroids, diuretics, caffeine, anti-asthmatics, nutritional supplements, and medications treating patent ductus arteriosus and pulmonary hypertension are discussed.

EXPERT OPINION

Dexamethasone is associated with adverse neurodevelopmental outcomes and impairment of adult lung function. Inhaled corticosteroids have not resulted in significant effects on BPD. Diuretics only result in short-term improvements in lung function and have side-effects. Evidence suggests it is better to wait and see than aggressively treat PDA; inhaled nitric oxide and sildenafil can improve oxygenation, but whether they improve long-term outcomes remains to be tested. Stem cells are a promising therapy, but further research is required. Appropriately designed trials are required to identify efficacious treatments for infants with BPD.

Beyond Bronchopulmonary Dysplasia: A Comprehensive Review of Chronic Lung Diseases in Neonates

In neonates, pulmonary diseases such as bronchopulmonary dysplasia and other chronic lung diseases (CLDs) pose significant challenges due to their complexity and high degree of morbidity and mortality. This review discusses the etiology, pathophysiology, clinical presentation, and diagnostic criteria for these conditions, as well as current management strategies. The review also highlights recent advancements in understanding the pathophysiology of these diseases and evolving strategies for their management, including gene therapy and stem cell treatments. We emphasize how supportive care is useful in managing these diseases and underscore the importance of a multidisciplinary approach. Notably, we discuss the emerging role of personalized medicine, enabled by advances in genomics and precision therapeutics, in tailoring therapy according to an individual's genetic, biochemical, and lifestyle factors. We conclude with a discussion on future directions in research and treatment, emphasizing the importance of furthering our understanding of these conditions, improving diagnostic criteria, and exploring targeted treatment modalities. The review underscores the need for multicentric and longitudinal studies to improve preventative strategies and better understand long-term outcomes. Ultimately, a comprehensive, innovative, and patient-centered approach can enhance the quality of care and outcomes for neonates with CLDs.

Childhood outcomes following discharge from a referral bronchopulmonary dysplasia program

OBJECTIVES

The primary objective of this study was to profile the childhood health, development, and health-related quality of life (HR QoL) for children with the most severe bronchopulmonary dysplasia (BPD), those discharged from a quaternary referral program.

STUDY DESIGN

We collected cross-sectional data through telephone interviews with 282 families of children ages 18 months to 11 years who had been discharged from a BPD referral program.

RESULTS

Respiratory morbidities were near universal, with 42% of children ever having required a tracheostomy and severity of these morbidities correlated with parent-reported health and QoL. Developmental morbidities were also marked: 97% required an individualized educational plan. While respiratory morbidities and overall health improved over time, developmental morbidities were increasingly prominent, resulting in lower quality of life.

CONCLUSIONS

Among children referred to a quaternary BPD program, respiratory and developmental morbidities are on numerous counts more severe than any reported in the literature.

Impact of severity and age with variable definitions of bronchopulmonary dysplasia on neurodevelopmental outcomes

BACKGROUND

Bronchopulmonary dysplasia (BPD) is associated with neurodevelopmental impairment (NDI).

METHODS

To compare the ability of NICHD 2001 and Jensen 2019 definitions of BPD and respiratory support at 40 weeks postmenstrual age (PMA) to predict NDI, a retrospective study (1/2010-12/2020) was conducted in infants with gestational age <32 weeks and birth weight <1500 g. The primary outcome measure was NDI at 18-24 months corrected age.

RESULTS

Of 1119 infants, 227 (20.7%) met the inclusion criteria and had adequate follow-up data. Multivariate regression analysis showed that the NICHD 2001 definition was not predictive of NDI. Infants with Grade 2 or 3 BPD (Jensen 2019) had 4.75 (95% CI: 1.282-17.563) times greater odds of having NDI than infants without BPD. Infants requiring respiratory support at 40 weeks PMA had 4.95 (95% CI: 1.490-16.47) times greater odds of having NDI. Receiver operating characteristic curves demonstrated that the 2 definitions of BPD and the need for respiratory support at 40 weeks PMA were similar in their ability to predict NDI.

CONCLUSION

There is no significant difference in the ability of the NICHD 2001 and Jensen 2019 BPD definitions, as well as the need for respiratory support at 40 weeks, for predicting NDI.

IMPACT STATEMENT

Current bronchopulmonary dysplasia (BPD) definitions may not effectively predict neurodevelopmental impairment (NDI) in preterm infants. Grades 2/3 BPD (Jensen 2019 criteria) significantly associate with NDI. Infants requiring respiratory support at 40 weeks post-menstrual age (PMA) have 5 times higher odds of NDI than those on room air at 40 weeks PMA. The NICHD 2001, Jensen 2019 definitions, and the requirement for respiratory support at 40 weeks PMA, do not differ in their ability to predict NDI. Future studies should include multiple centers, with level III-IV NICUs, catering to socioeconomic, culturally, and racially diverse populations.

Evaluation of the Relationship between Pain Exposure and Somatosensory Evoked Potentials in Preterm Infants: A Prospective Cohort Study

BACKGROUND AND AIM

First, to compare somatosensory evoked potentials (SEPs) in preterm newborns without major brain injury studied at term equivalent age (TEA) with a term historical control group. Second, to investigate the impact of pain exposure during the first 28 days after birth on SEPs. Third, to evaluate the association between SEPs and Bayley-III at 2 years corrected age (CA).

METHODS

Infants born at <32 weeks' gestational age (GA) were studied with continuous-SEPs. First, SEP differences between preterm and term infants were analyzed. Second, regression analyses were conducted to explore the association between SEPs and painful procedures, and then between SEPs and neurodevelopment.

RESULTS

86 preterm infants were prospectively enrolled. Preterm infants exhibited prolonged N1 latencies, central conduction times (CCTs), lower N1-P1 amplitudes, and more recurrently abnormal SEPs compared to term infants. Higher pain exposure predicted longer N1 latency and slower CCT (all p < 0.005), adjusting for clinical risk factors. Younger GA and postmenstrual age (PMA) at SEP recording were associated with longer N1 latency and lower N1-P1 amplitude (all p < 0.005). A normal SEP at TEA positively predicted cognitive outcome at 2 years CA (p < 0.005).

CONCLUSION

Pain exposure and prematurity were risk factors for altered SEP parameters at TEA. SEPs predicted cognitive outcome.

Effect of acute histologic chorioamnionitis on bronchopulmonary dysplasia and mortality rate among extremely low gestational age neonates: A retrospective case-control study

OBJECTIVE

To evaluate whether acute histologic chorioamnionitis (HCA) diagnosed in the placenta may be associated with an increased occurrence of bronchopulmonary dysplasia (BPD) or death among extremely low gestational age neonates (ELGAN).

METHODS

This Italian single-center case-control retrospective study involved ELGAN admitted to the neonatal intensive care unit between January 2019 and June 2022. Infants born from pregnant women with acute and severe HCA, identified as stage ≥2 and grade 2 HCA, (HCA-infants) were compared with infants of pregnant women without chorioamnionitis or with stage 1, grade 1 chorioamnionitis (no-HCA-infants).

RESULTS

Among 101 eligible ELGAN, 63 infants had complete clinical and histologic data relevant to the study: thirty infants were included in the HCA-infants group and 33 in the no-HCA-infants group. Neonatal and maternal demographic and clinical characteristics were similar between the two groups. Infants born from mothers with acute and severe HCA had significantly higher occurrence of composite BPD or death (18 [60%] vs. 9 [27%]; P = 0.012), as well as higher incidence of severe forms of BPD (6 [30%] vs. 2 [6%]; P = 0.045). In multiple logistic regression analysis, after adjustment for confounding covariates, HCA was an independent risk factor for BPD or death (OR, 4.49; 95% CI: 1.47-13.71).

CONCLUSIONS

This is the first study showing that in utero exposure to acute and severe HCA is an independent risk factor for the occurrence of composite BPD or death among ELGAN.

Efficacy and safety of different inhaled corticosteroids for bronchopulmonary dysplasia prevention in preterm infants: A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to evaluate the efficacy and safety of inhaled corticosteroids (budesonide, beclomethasone, or fluticasone propionate) in preventing bronchopulmonary dysplasia (BPD) for premature infants.

METHOD

Electronic databases, including PubMed, EMBASE, Web of science, Scopus, and Cochrane library, were searched from databases inception to January 2022 for eligible randomized controlled trials. Clinical outcomes such as BPD, mortality, BPD or death, adverse events, and neurodevelopmental outcomes were assessed.

RESULTS

Overall, budesonide was significantly associated with a reduction in BPD at 36 weeks' postmenstrual age (RR 0.48; 95 % CI [0.38, 0.62]) and patent ductus arteriosus (PDA) (RR 0.75; 95 % CI [0.63, 0.89]) compared with control treatments. Early longer duration inhalation of budesonide alone was associated with a lower risk of BPD at 36 weeks' postmenstrual age and PDA compared with controls. Early shorter duration intratracheal instillation of budesonide with surfactant as vehicle was associated with a lower risk of BPD at 36 weeks' postmenstrual age and all-cause mortality compared with surfactant. There was no statistically significant difference between budesonide and control groups regarding neurodevelopmental impairment. Beclomethasone and fluticasone propionate did not show any superior or inferior effect on clinical outcomes compared to control treatments.

CONCLUSION

These findings suggest that budesonide, especially intratracheal instillation of budesonide using surfactant as a vehicle, is a safe and effective option in preventing BPD for preterm infants. More well-design large-scale trials with long-term follow-ups are necessary to verify the present findings.

Sampling pattern discrepancy in the application of compressed sensing hyperpolarized xenon-129 lung MRI

Although hyperpolarized (HP) 129Xe ventilation MRI can be carried out within a breath hold, it is still challenging for many sick patients. Compressed sensing (CS) is a viable alternative to accelerate this approach. However, undersampled images with identical sampling ratios differ from one another. Twenty subjects (n = 10 healthy and n = 10 patients with asthma) were scanned using a GE MR750 3 T scanner, acquiring fully sampled 2D multi-slice HP 129Xe lung ventilation images (10 s breath hold, 128 × 80 (FE × PE-frequency encoding × phase encoding) and 16 slices). Using fully sampled data, 500 variable-density Cartesian random undersampling patterns were generated, each at eight different sampling ratios from 10% to 80%. The parallel imaging and compressed sensing (PICS) command from BART was employed to reconstruct undersampled data. The signal to noise ratio (SNR), structural similarity index measurement (SSIM) and sidelobe to peak ratio of each were subsequently compared. There was a high degree of variation in both SNR and SSIM results from each of the 500 masks of each sampling rate. As the undersampling increases, there is more variation in the quantifying metrics, for both healthy and asthmatic individuals. Our study shows that random undersampling poses a significant challenge when applied at sampling ratios less than 60%, despite fulfilling CS's incoherency criteria. Such low sampling ratios will result in a large variety of undersampling patterns. Therefore, skipped segments of k-space cannot be allowed to happen randomly at low sampling rates. By optimizing the sampling pattern, CS will reach its full potential and be able to be applied to a highly undersampled 129Xe lung dataset.

Recent progress in neonatal hyperoxic lung injury

With the progress in neonatal intensive care, there has been an increase in the survival rates of premature infants. However, this has also led to an increased incidence of neonatal hyperoxia lung injury and bronchopulmonary dysplasia (BPD), whose pathogenesis is believed to be influenced by various prenatal and postnatal factors, although the exact mechanisms remain unclear. Recent studies suggest that multiple mechanisms might be involved in neonatal hyperoxic lung injury and BPD, with sex also possibly playing an important role, and numerous drugs have been proposed and shown promise for improving the treatment outcomes of hyperoxic lung injury. Therefore, this paper aims to analyze and summarize sex differences in neonatal hyperoxic lung injury, potential pathogenesis and treatment progress to provide new ideas for basic and clinical research in this field.

Quality Improvement Initiative Enhances Outpatient Pediatric Pulmonology Follow-up for Premature Infants with Bronchopulmonary Dysplasia

Introduction

Bronchopulmonary dysplasia (BPD) is a chronic lung disorder affecting many premature infants. Infants with BPD have higher hospital readmission rates due to respiratory-related morbidity. We aimed to increase the rates of outpatient pulmonary follow-up and attendance of premature babies with moderate and severe BPD to above 85% within 6 months.

Methods

We conducted a quality improvement project at Yale New Haven Children's Hospital. Key interventions included developing a BPD clinical pathway integrated into the electronic medical record to assist providers in correctly classifying BPD severity, assigning the appropriate International Classification of Diseases, 10th Revision code (P27.1), and providing standardized treatment options. The outcome measures included correct diagnosis and classification of BPD, the percentage of patients with BPD scheduled for pediatric pulmonology appointments within 45 days, and the percentage attending those appointments.

Results

There were 226 patients in our study, including 85 in the baseline period. Correct diagnosis of BPD increased from 49% to 95%, the percentage of scheduled appointments increased from 71.9% to 100%, and the percentage of appointments attended increased from 55.6% to 87.1%.

Conclusions

Our quality improvement initiative improved the accuracy of diagnosis, severity classification, and outpatient pulmonary follow-up of children with moderate and severe BPD.

Childhood atopic disorders in relation to placental changes-A systematic review and meta-analysis

Fetal programming may arise from prenatal exposure and increase the risk of diseases later in life, potentially mediated by the placenta. The objective of this systematic review was to summarize and critically evaluate publications describing associations between human placental changes and risk of atopic disorders during childhood. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The inclusion criteria were original research articles or case reports written in English describing a human placental change in relation to disease occurring in offspring during childhood. The MEDLINE and EMBASE databases were searched for eligible studies. Risk of bias (RoB) was assessed using the ROBINS-I tool. The results were pooled both in a narrative way and by a meta-analysis. Nineteen studies were included (n = 12,997 participants). All studies had an overall serious RoB, and publication bias could not be completely ruled out. However, five studies showed that histological chorioamnionitis in preterm-born children was associated with asthma-related problems (pooled odds ratio = 3.25 (95% confidence interval = 2.22-4.75)). In term-born children, a large placenta (≥750 g) increased the risk of being prescribed anti-asthma medications during the first year of life. Placental histone acetylation, DNA methylation, and gene expression differences were found to be associated with different atopic disorders in term-born children. There is some evidence supporting the idea that the placenta can mediate an increased risk of atopic disorders in children. However, further studies are needed to validate the findings, properly control for confounders, and examine potential mechanisms.

Insulin for Treatment of Neonatal Hyperglycemia in Premature Infants: Prevalence over Time and Association with Outcomes

OBJECTIVE

Our objective was to determine the prevalence of insulin treatment in premature infants with hyperglycemia and evaluate the association of length of treatment with outcomes.

STUDY DESIGN

The study included cohort of 29,974 infants 22 to 32 weeks gestational age (GA) admitted to over 300 neonatal intensive care unit (NICU) from 1997 to 2018 and diagnosed with hyperglycemia.

RESULTS

Use of insulin significantly decreased during the study period (p = 0.002) among studied NICUs. The percentage of hyperglycemic infants exposed to insulin ranged from 0 to 81%. Infants who received insulin were more likely to have lower GA, birth weight, 5-minute Apgar score, longer duration of stay, and require mechanical ventilation. After adjustment for GA, infants requiring insulin for >14 days were more likely to have treated retinopathy of prematurity (ROP) and develop chronic lung disease (CLD). Insulin treatment of 1 to 7 days had increased odds of death, death/ROP, and death/CLD compared with no exposure.

CONCLUSION

Insulin use decreased over time, and differing durations of use were associated with adverse outcomes.

KEY POINTS

· Insulin use decreased over time.. · There is a temporal relation between the duration of treatment and adverse outcomes.. · Further studies are needed to determine the efficacy and safety of insulin use..

Characteristics and Outcomes of Intrahospital Transfers from Neonatal Intensive Care to Pediatric Intensive Care Units

OBJECTIVE

Critically ill children may be transferred from the neonatal intensive care unit (NICU) to the pediatric intensive care unit (PICU) for further critical care, but the frequency and outcomes of this patient population are unknown. The aims of this study are to describe the characteristics and outcomes in patients transferred from NICU to PICUs. We hypothesized that a higher-than-expected mortality would be present for patients with respiratory or cardiovascular diagnoses that underwent a NICU to PICU transition and that specific factors (timing of transfer, illness severity, and critical care interventions) are associated with a higher risk of mortality in the cardiovascular group.

STUDY DESIGN

Retrospective analysis of Virtual Pediatric Systems, LLC (2011-2019) deidentified cardiovascular and respiratory NICU to PICU subject data. We evaluated demographics, PICU length of stay, procedures, disposition, and mortality scores. Pediatric Index of Mortality 2 (PIM2) score was utilized to determine the standardized mortality ratio (SMR).

RESULTS

SMR of 4,547 included subjects (3,607 [79.3%] cardiovascular and 940 [20.7%] respiratory) was 1.795 (95% confidence interval: 1.62-1.97, p < 0.0001). Multivariable logistic regression analysis demonstrated transfer age (cardiovascular: odds ratio, 1.246 [1.10-1.41], p = 0.0005; respiratory: 1.254 [1.07-1.47], p = 0.0046) and PIM2 scores (cardiovascular: 1.404 [1.25-1.58], p < 0.0001; respiratory: 1.353 [1.08-1.70], p = 0.0095) were significantly associated with increased odds of mortality.

CONCLUSION

In this present study, we found that NICU to PICU observed deaths were high and various factors, particularly transfer age, were associated with increased odds of mortality. While the type of patients evaluated in this study likely influenced mortality, further investigation is warranted to determine if transfer timing is also a factor.

KEY POINTS

· NICU patients may be transitioned to the PICU.. · NICU to PICU observed deaths were high.. · Transfer timing may be a factor..

Neurodevelopmental Outcomes of Preterm Infants Born <29 Weeks with Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension: A Multicenter Study

OBJECTIVE

This study aimed to determine neurodevelopmental outcomes of preterm infants born at <29 weeks' gestational age (GA) with bronchopulmonary dysplasia and pulmonary hypertension (BPD-PH) at 18 to 24 months' corrected age (CA).

STUDY DESIGN

In this retrospective cohort study, preterm infants born at <29 weeks' GA between January 2016 and December 2019, admitted to level 3 neonatal intensive care units, who developed BPD and were evaluated at 18 to 24 months' CA in the neonatal follow-up clinics were included. We compared demographic characteristics and neurodevelopmental outcomes between the two groups: Group I: BPD with PH and Group II: BPD with no PH, using univariate and multivariate regression models. The primary outcome was a composite of death or neurodevelopmental impairment (NDI). NDI was defined as any Bayley-III score < 85 on one or more of the cognitive, motor, or language composite scores.

RESULTS

Of 366 eligible infants, 116 (Group I [BPD-PH] =7, Group II [BPD with no PH] = 109) were lost to follow-up. Of the remaining 250 infants, 51 in Group I and 199 in Group II were followed at 18 to 24 months' CA. Group I and Group II had median (interquartile range [IQR]) birthweights of 705 (325) and 815 g (317; p = 0.003) and median GAs (IQR) were 25 (2) and 26 weeks (2; p = 0.015) respectively. Infants in the BPD-PH group (Group I) were more likely to have mortality or NDI (adjusted odds ratio: 3.82; bootstrap 95% confidence interval; 1.44-40.87).

CONCLUSION

BPD-PH in infants born at <29 weeks' GA is associated with increased odds of the composite outcome of death or NDI at 18 to 24 months' CA.

KEY POINTS

· Long-term neurodevelopmental follow-up of preterm infants born <29 weeks' GA.. · Association of neurodevelopmental outcomes with BPD-associated PH.. · Need for longitudinal follow-up of children with BPD-associated PH..

Protective Effects of Resveratrol Against Airway Hyperreactivity, Oxidative Stress, and Lung Inflammation in a Rat Pup Model of Bronchopulmonary Dysplasia

Oxygen therapy provides an important treatment for preterm and low-birth-weight neonates, however, it has been shown that prolonged exposure to high levels of oxygen (hyperoxia) is one of the factors contributing to the development of bronchopulmonary dysplasia (BPD) by inducing lung injury and airway hyperreactivity. There is no effective therapy against the adverse effects of hyperoxia. Therefore, this study was undertaken to test the hypothesis that natural phytoalexin resveratrol will overcome hyperoxia-induced airway hyperreactivity, oxidative stress, and lung inflammation. Newborn rats were exposed to hyperoxia (fraction of inspired oxygen - FiO2>95 % O2) or ambient air (AA) for seven days. Resveratrol was supplemented either in vivo (30 mg·kg-1·day-1) by intraperitoneal administration or in vitro to the tracheal preparations in an organ bath (100 mikroM). Contractile and relaxant responses were studied in tracheal smooth muscle (TSM) using the in vitro organ bath system. To explain the involvement of nitric oxide in the mechanisms of the protective effect of resveratrol against hyperoxia, a nitric oxide synthase inhibitor - Nomega-nitro-L-arginine methyl ester (L-NAME), was administered in some sets of experiments. The superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and the tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels in the lungs were determined. Resveratrol significantly reduced contraction and restored the impaired relaxation of hyperoxia-exposed TSM (p<0.001). L-NAME reduced the inhibitory effect of resveratrol on TSM contractility, as well as its promotion relaxant effect (p<0.01). Resveratrol preserved the SOD and GPx activities and decreased the expression of TNF-alpha and IL-1beta in hyperoxic animals. The findings of this study demonstrate the protective effect of resveratrol against hyperoxia-induced airway hyperreactivity and lung damage and suggest that resveratrol might serve as a therapy to prevent the adverse effects of neonatal hyperoxia. Keywords: Bronchopulmonary dysplasia, Hyperoxia, Airway hyperreactivity, Resveratrol, Pro-inflammatory cytokines.

Bronchopulmonary dysplasia: temporal trend from 2010 to 2019 in the Brazilian Network on Neonatal Research

OBJECTIVE

To evaluate the temporal trend of bronchopulmonary dysplasia (BPD) in preterm infants who survived to at least 36 weeks' post-menstrual age (PMA) and BPD or death at 36 weeks' PMA, and to analyse variables associated with both outcomes.

DESIGN

Retrospective cohort with data retrieved from an ongoing national registry.

SETTING

19 Brazilian university public hospitals.

PATIENTS

Infants born between 2010 and 2019 with 23-31 weeks and birth weight 400-1499 g.

MAIN OUTCOME MEASURES

Temporal trend was evaluated by Prais-Winsten model and variables associated with BPD in survivors or BPD or death were analysed by logistic regression.

RESULTS

Of the 11 128 included infants, BPD in survivors occurred in 22%, being constant over time (annual per cent change (APC): -0.80%; 95% CI: -2.59%; 1.03%) and BPD or death in 45%, decreasing over time (APC: -1.05%; 95% CI: -1.67%; -0.43%). Being male, small for gestational age, presenting with respiratory distress syndrome, air leaks, needing longer duration of mechanical ventilation, presenting with treated patent ductus arteriosus and late-onset sepsis were associated with an increase in the chance of BPD. For the outcome BPD or death, maternal bleeding, multiple gestation, 5-minute Apgar <7, late-onset sepsis, necrotising enterocolitis and intraventricular haemorrhage were added to the variables reported above as increasing the chance of the outcome.

CONCLUSION

The frequency of BPD in survivors was constant and BPD or death decreased by 1.05% at each study year. These results show some improvement in perinatal care in Brazilian units which resulted in a reduction of BPD or death, but further improvements are still needed to reduce BPD in survivors.

Metabolomic Analysis Reveals the Association of Severe Bronchopulmonary Dysplasia with Gut Microbiota and Oxidative Response in Extremely Preterm Infants

Bronchopulmonary dysplasia (BPD) is a chronic lung disease mainly affecting premature infants needing ventilation or oxygen for respiratory distress. This study aimed to evaluate the molecular linkages for BPD in very and extremely preterm infants using a metabolomics-based approach. A case-control study of enrolling preterm infants born before 32 weeks gestational age (GA) was prospectively performed. These preterm infants were subsequently stratified into the following two groups for further analysis: no or mild BPD, and moderate or severe BPD based on the 2019 NICHD criteria. Urinary metabolomic profiling was performed using 1H-Nuclear magnetic resonance (NMR) spectroscopy coupled with partial least squares discriminant analysis (PLS-DA) at a corrected age of 6 months. Metabolites significantly differentially related to GA and BPD severity were performed between groups, and their roles in functional metabolic pathways were also assessed. A total of 89 preterm infants born before 32 weeks gestation and 50 infants born at term age (above 37 completed weeks' gestation) served as controls and were enrolled into the study. There were 21 and 24 urinary metabolites identified to be significantly associated with GA and BPD severity, respectively (p < 0.05). Among them, N-phenylacetylglycine, hippurate, acetylsalicylate, gluconate, and indoxyl sulfate were five metabolites that were significantly higher, with the highest importance in both infants with GA < 28 weeks and those with moderate to severe BPD, whereas betaine and N,N-dimethylglycine were significantly lower (p < 0.05). Furthermore, ribose and a gluconate related pentose phosphate pathway were strongly associated with these infants (p < 0.01). In conclusion, urinary metabolomic analysis highlights the crucial role of gut microbiota dysbiosis in the pathogenesis of BPD in preterm infants, accompanied by metabolites related to diminished antioxidative capacity, prompting an aggressive antioxidation response in extremely preterm infants with severe BPD.

Assessing the agreement of chronic lung disease of prematurity diagnosis between radiologists and clinical criteria

BACKGROUND

Chronic lung disease of prematurity (CLD) is the most prevalent complication of preterm birth and indicates an increased likelihood of long-term pulmonary complications. The accurate diagnosis of this condition is critical for long-term health management. Numerous definitions define CLD with different clinical parameters and radiology findings, making diagnosis of the disease ambiguous and potentially inaccurate.

METHODS

95 patients were identified for this study, as determined by the diagnosis or confirmation of CLD in the impression of the radiologist's report on chest x-ray. Pulmonary function and complications were recorded at multiple benchmark timeframes within each patient's first few months of life and used for determining eligibility under each definition.

RESULTS

Each clinical definition of CLD had a high sensitivity for patients identified to have CLD by radiologists, correctly fitting over 90% of patients. Most patients included required invasive mechanical ventilation or positive pressure ventilation at 36 weeks postmenstrual age, indicating patients with radiographically confirmed CLD tended to have more severe disease. Radiologists tended to diagnose CLD before 36 weeks postmenstrual age, a timepoint used by multiple standard clinical definitions, with cases called earlier fitting under a larger percentage of definitions than those called later.

CONCLUSIONS

Radiologists tend to diagnose CLD in young patients with severe respiratory compromise, and can accurately diagnose the condition before developmental milestones for clinical definitions are met.

Types of home respiratory support in children with bronchopulmonary dysplasia and factors determining its duration: A scoping review

Bronchopulmonary dysplasia also known as chronic lung disease of prematurity has changed as a disease entity over the last five decades and children with "new bronchopulmonary dysplasia (BPD)" have better survival rates. This necessitates strategies to prevent severe BPD and provide organized home support. Home respiratory support in these children varies from home oxygen to noninvasive ventilation and tracheostomy ventilation. This review was conducted utilizing Joanna Briggs Institute publications on evidence synthesis and presentation of results for a scoping review. The Preferred Reporting Items for Systematic Review and Meta-Analyses were used to report the results. The risk of bias assessment was done using "The Cochrane Handbook for Systematic Reviews tool for interventional studies." After screening for the duplication of results and applying inclusion and exclusion criteria, twenty-seven studies were assessed by reading the full texts. Out of these, eleven were finally included in this systematic review. The total sample size from all studies was 4794, including 2705 males. The 4/11 studies home oxygen, one study reported continuous positive airway pressure/bilevel positive airway pressure and seven studies used tracheostomy or tracheostomy ventilation. The median duration of post-natal invasive ventilation was higher in those discharged on home oxygen compared to those who did not need oxygen at discharge. There is a significant proportion of children who are tracheostomy ventilated (8.65%) at home. In the absence of established guidelines, these children are vulnerable when it comes to care at home and the timing of decannulation. For home oxygen alone, guidelines by ERS, ATS and BTS have streamlined weaning protocols and the need for having a multi-disciplinary team to care for these children.

Long-term pulmonary outcomes of young adults born prematurely: a Polish prospective cohort study PREMATURITAS 20

BACKGROUND

The long-term consequences of prematurity are often not sufficiently recognized. To address this gap, a prospective cohort study, which is a continuation of the multicenter Polish study PREMATURITAS, was conducted, utilizing unique clinical data from 20 years ago.

OBJECTIVE

The main goal was to evaluate lung function, detect any structural abnormalities using lung ultrasound, and assess psychological well-being in young adults born between 24 and 34 weeks of gestational age (GA). Additionally, the study aimed to investigate potential associations between perinatal risk factors and abnormalities observed in pulmonary function tests (PFTs) during adulthood.

METHODS

The young survivors underwent a comprehensive set of PFTs, a lung ultrasound, along with the quality of life assessment. Information regarding the neonatal period and respiratory complications was obtained from the baseline data collected in the PREMATURITAS study.

RESULTS

A total of 52 young adults, with a mean age of 21.6 years, underwent PFTs. They were divided into two groups based on GA: 24-28 weeks (n = 12) and 29-34 weeks (n = 40). The subgroup born more prematurely had significantly higher lung clearance index (LCI), compared to the other subgroup (p = 0.013). LCI ≥ 6.99 was more frequently observed in the more premature group (50% vs. 12.5%, p = 0.005), those who did not receive prenatal steroids (p = 0.020), with a diagnosis of Respiratory Distress Syndrome (p = 0.034), those who received surfactant (p = 0.026), and mechanically ventilated ≥ 7 days (p = 0.005). Additionally, elevated LCI was associated with the diagnosis of asthma (p = 0.010).

CONCLUSIONS

The findings suggest pulmonary effects due to prematurity persist into adulthood and their insult on small airway function. Regular follow-up evaluations of young survivors born preterm should include assessments of PFTs. Specifically, the use of LCI can provide valuable insights into long-term pulmonary impairment.

Bronchopulmonary dysplasia in adults: Exploring pathogenesis and phenotype

This review highlights both the longstanding impact of bronchopulmonary dysplasia (BPD) on the health of adult survivors of prematurity and the pressing need for prospective, longitudinal studies of this population. Conservatively, there are an estimated 1,000,000 survivors of BPD in the United States alone. Unfortunately, most of the available literature regarding outcomes of lung disease due to prematurity naturally focuses on pediatric patients in early or middle childhood, and the relative amount of literature on adult survivors is scant. As the number of adult survivors of BPD continues to increase, it is essential that both adult and pediatric pulmonologists have a comprehensive understanding of the pathophysiology and underlying disease process, including the molecular signaling pathways and pro-inflammatory modulators that contribute to the pathogenesis of BPD. We summarize the most common presenting symptoms for adults with BPD and identify the critical challenges adult pulmonologists face in managing the care of survivors of prematurity. Specifically, these challenges include the wide variability of the clinical presentation of adult patients, comorbid cardiopulmonary complications, and the paucity of longitudinal data available on these patients. Adult survivors of BPD have even required lung transplantation, indicating the high burden of morbidity that can result from premature birth and subsequent lung injury. In addition, we analyze the disparate symptoms and management approach to adults with "old" BPD versus "new" BPD. The aim of this review is to assist pulmonologists in understanding the underlying pathophysiology of BPD and to improve clinical recognition of this increasingly common pulmonary disease.

Clinical exome sequencing elucidates underlying cause of death in sudden unexpected death of infants: two case reports

Sudden unexpected death in infants (SUDI) is a traumatic event for families, and unfortunately its occurrence remains high in many parts of the world. Whilst cause of death is resolved for most cases, others remain undetermined following postmortem investigations. There has been a recognition of the role of genetic testing in unexplained cases, where previous studies have demonstrated the resolution of cases through DNA analyses. Here we present two case reports of SUDI cases admitted to Salt River Mortuary, South Africa, and show that underlying causes of death were determined for both infants using clinical exome sequencing. The first infant was heterozygous for a variant (rs148175795) in COL6A3, which suggested a bronchopulmonary dysplasia phenotype. This hypothesis led to finding of a second candidate variant in DMP1 (rs142880465), which may contribute towards a digenic/polygenic mechanism of a more severe phenotype. Histological analysis of retained tissue sections showed an asphyxial mechanism of death, where bronchiolar muscle weakness from an underlying bronchopulmonary dysplasia may have contributed to the asphyxia by affecting respiration. In the second infant, a homozygous variant (rs201340753) was identified in MASP1, which was heterozygous in each parent, highlighting the value of including parental DNA in genetic studies. Whilst mannose-binding lectin deficiency could not be assessed, it is plausible that this variant may have acted in combination with other risk factors within the triple-risk model to result in sudden death. These results may have genetic implications for family members, and represent possible new candidate variants for molecular autopsies.

Human Milk Cessation in the NICU in Infants with Bronchopulmonary Dysplasia

OBJECTIVE

The objective of this study was to identify factors associated with the cessation of human milk prior to neonatal intensive care unit (NICU) discharge for infants diagnosed with bronchopulmonary dysplasia (BPD).

STUDY DESIGN

Participants were recruited from the Johns Hopkins BPD Clinic between January 2016 and October 2018. Clinical and demographic characteristics were analyzed based on whether participants stopped human milk before or after NICU discharge.

RESULTS

Of the 224 infants included, 109 (48.7%) infants stopped human milk prior to discharge. The median duration of human milk intake was less for infants who stopped human milk prior to discharge compared with those who continued after discharge (2 vs. 8 months, p < 0.001). In multivariate regression analysis, pulmonary hypertension (odds ratio [OR]: 2.90; p = 0.016), public insurance (OR: 2.86; p < 0.001), and length of NICU admission (OR: 1.26 per additional month; p = 0.002) were associated with human milk cessation prior to NICU discharge.

CONCLUSION

Infants with BPD who have severe medical comorbidities and markers of lower socioeconomic status may be at higher risk for earlier human milk discontinuation.

KEY POINTS

· Half of infants in our study with BPD who received human milk stopped human milk prior to NICU discharge.. · For infants on human milk after discharge, the duration of human milk intake was 8.6 months.. · Infants with pulmonary hypertension, tracheostomies, and ventilation stopped human milk earlier.. · Non-White race, lower income, and public insurance were predictors of early human milk cessation..

Lysine demethylase KDM3A alleviates hyperoxia-induced bronchopulmonary dysplasia in mice by promoting ETS1 expression

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease among neonates, with increasing morbidity and mortality. This study aims to investigate the effect and mechanism of lysine demethylase 3A (KDM3A) on hyperoxia-induced BPD. Hyperoxia-induced BPD mouse and alveolar epithelial cell models were constructed. The effects of hyperoxia on lung development were evaluated by histological and morphological analysis. The levels of KDM3A, E26 transformation specific-1 (ETS1), H3 lysine 9 dimethylation (H3K9me2), and endoplasmic reticulum (ER) stress-related indexes were quantified by RT-qPCR, Western blot, and IF staining. Cell apoptosis was assessed by flow cytometry and TUNEL staining. Transfection of oe-ETS1, oe-KDM3A, and sh-ETS1 was applied in hyperoxia-induced alveolar epithelial cells to explore the mechanism of the KDM3A/ETS1 axis in hyperoxia-induced apoptosis. KDM3A inhibitor IOX1 was applied to validate the in vivo effect of KDM3A in hyperoxia-induced BPD mice. The results displayed that hyperoxia-induced BPD mice showed reduced body weight, severe destruction of alveolar structure, decreased radial alveolar count (RAC), and increased mean linear intercept (MLI) and mean alveolar diameter (MAD). Further, hyperoxia induction down-regulated ETS1 expression, raised ER stress levels, and increased apoptosis rate in BPD mice and alveolar epithelial cells. However, transfection of oe-ETS1 improved the above changes in hyperoxia-induced alveolar epithelial cells. Moreover, transfection of oe-KDM3A up-regulated ETS1 expression, down-regulated H3K9me2 expression, inhibited ER stress, and reduced apoptosis rate in hyperoxia-induced alveolar epithelial cells. In addition, transfection of sh-ETS1 reversed the inhibitory effect of KDM3A on hyperoxia-induced apoptosis by regulating ER stress. In vivo experiments, KDM3A inhibitor IOX1 intervention further aggravated BPD in newborn mice. In a word, KDM3A alleviated hyperoxia-induced BPD in mice by promoting ETS1 expression.

Outcomes of postnatal systemic corticosteroids administration in ventilated preterm newborns: a systematic review of randomized controlled trials

Introduction

Prolonged mechanical ventilation, commonly used to assist preterm newborns, increases the risk of developing bronchopulmonary dysplasia (BPD). In recent decades, studies have demonstrated that systemic corticosteroids play a significant role in the prevention and management of BPD. In this systematic review of randomized controlled trials (RCTs), we evaluated the association between the administration of systemic corticosteroids in preterm infants and its long-term outcomes, such as neurodevelopment, growth, extubation rate, and related adverse effects.

Methods

We conducted an electronic search in Medline, Scopus, and PubMed using the following terms: "premature infants" and "corticosteroids." We considered all RCTs published up to June 2023 as eligible. We included all studies involving preterm newborns treated with systemic corticosteroids and excluded studies on inhaled corticosteroids.

Results

A total of 39 RCTs were evaluated. The influence of steroids administered systemically during the neonatal period on long-term neurological outcomes remains unknown, with no influence observed for long-term growth. The postnatal administration of systemic corticosteroids has been found to reduce the timing of extubation and improve respiratory outcomes. Dexamethasone appears to be more effective than hydrocortisone, despite causing a higher rate of systemic hypertension and hyperglycemia. However, in the majority of RCTs analyzed, there were no differences in the adverse effects related to postnatal corticosteroid administration.

Conclusion

Dexamethasone administered during the neonatal period appears to be more effective than hydrocortisone in terms of respiratory outcomes; however, caution should be taken when administering dexamethasone. Data derived from current evidence, including meta-analyses, are inconclusive on the long-term effects of the administration of systemic steroids in preterm infants or the possibility of neurodevelopmental consequences.

Effect of Systemic Hydrocortisone on Brain Abnormalities and Regional Brain Volumes in Ventilator-dependent Infants Born Preterm: Substudy of the SToP-BPD Study

OBJECTIVE

To evaluate whether a high cumulative dose of systemic hydrocortisone affects brain development compared with placebo when initiated between 7 and 14 days after birth in ventilated infants born preterm.

STUDY DESIGN

A double-blind, placebo-controlled, randomized trial was conducted in 16 neonatal intensive care units among infants born at <30 weeks of gestation or with a birth weight of <1250 g who were ventilator-dependent in the second week after birth. Three centers performed MRI at term-equivalent age. Brain injury was assessed on MRI using the Kidokoro scoring system and compared between the 2 treatment groups. Both total and regional brain volumes were calculated using an automatic segmentation method and compared using multivariable regression analysis adjusted for baseline variables.

RESULTS

From the 3 centers, 78 infants participated in the study and 59 had acceptable MRI scans (hydrocortisone group, n = 31; placebo group, n = 28). Analyses of the median global brain abnormality score of the Kidokoro score showed no difference between the hydrocortisone and placebo groups (median, 7; IQR, 5-9 vs median, 8, IQR, 4-10, respectively; P = .92). In 39 infants, brain tissue volumes were measured, showing no differences in the adjusted mean total brain tissue volumes, at 352 ± 32 mL in the hydrocortisone group and 364 ± 51 mL in the placebo group (P = .80).

CONCLUSIONS

Systemic hydrocortisone started in the second week after birth in ventilator-dependent infants born very preterm was not found to be associated with significant differences in brain development compared with placebo treatment.

TRIAL REGISTRATION

The SToP-BPD study was registered with the Netherlands Trial Register (NTR2768; registered on 17 February 2011; https://www.trialregister.nl/trial/2640) and the European Union Clinical Trials Register (EudraCT, 2010-023777-19; registered on 2 November 2010; https://www.clinicaltrialsregister.eu/ctr-search/trial/2010-023777-19/NL).

Cellular Senescence Contributes to the Progression of Hyperoxic Bronchopulmonary Dysplasia

Oxidative stress, inflammation, and endoplasmic reticulum (ER) stress sequentially occur in bronchopulmonary dysplasia (BPD), and all result in DNA damage. When DNA damage becomes irreparable, tumor suppressors increase, followed by apoptosis or senescence. Although cellular senescence contributes to wound healing, its persistence inhibits growth. Therefore, we hypothesized that cellular senescence contributes to BPD progression. Human autopsy lungs were obtained. Sprague-Dawley rat pups exposed to 95% oxygen between Postnatal Day 1 (P1) and P10 were used as the BPD phenotype. N-acetyl-lysyltyrosylcysteine-amide (KYC), tauroursodeoxycholic acid (TUDCA), and Foxo4 dri were administered intraperitoneally to mitigate myeloperoxidase oxidant generation, ER stress, and cellular senescence, respectively. Lungs were examined by histology, transcriptomics, and immunoblotting. Cellular senescence increased in rat and human BPD lungs, as evidenced by increased oxidative DNA damage, tumor suppressors, GL-13 stain, and inflammatory cytokines with decreased cell proliferation and lamin B expression. Cellular senescence-related transcripts in BPD rat lungs were enriched at P10 and P21. Single-cell RNA sequencing showed increased cellular senescence in several cell types, including type 2 alveolar cells. In addition, Foxo4-p53 binding increased in BPD rat lungs. Daily TUDCA or KYC, administered intraperitoneally, effectively decreased cellular senescence, improved alveolar complexity, and partially maintained the numbers of type 2 alveolar cells. Foxo4 dri administered at P4, P6, P8, and P10 led to outcomes similar to TUDCA and KYC. Our data suggest that cellular senescence plays an essential role in BPD after initial inducement by hyperoxia. Reducing myeloperoxidase toxic oxidant production, ER stress, and attenuating cellular senescence are potential therapeutic strategies for halting BPD progression.

Morphine exposure and prematurity affect flash visual evoked potentials in preterm infants

Objective

The present study aimed to explore first the impact of perinatal risk factors on flash-VEP waves and morphology in a group of preterm infants studied at term equivalent age (TEA). Second, to correlate VEP morphology with neurological outcome at 2 years corrected age (CA).

Methods

Infants with a gestational age (GA) at birth <32 weeks, without major brain injury, were enrolled. Multivariate regression analyses were performed, and the models were run separately for each dependent variable N2, P2, N3 latencies and P2 amplitude. Logistic regression was applied to study N4 component (present/absent) and VEP morphology (regular/irregular). The predictors were GA, bronchopulmonary dysplasia (BPD), postmenstrual age at VEP registration, cumulative morphine and fentanyl dose, and painful procedures. Lastly, linear regression models were performed to assess the relation between the Bayley-III cognitive and motor scores at 2 years CA and VEP morphology, in relation to GA, BPD, painful procedures and cumulative morphine dose.

Results

Eighty infants were enrolled. Morphine was the predictor of N2 (R2 = 0.09, p = 0.006), P2 (R2 = 0.11, p = 0.002), and N3 (R2 = 0.13, p = 0.003) latencies. Younger GA was associated with lower amplitude (R2 = 0.05, p = 0.029). None of the independent variables predicted the presence of N4 component, nor VEP morphology in the logistic analysis. VEP morphology was not associated with cognitive and motor scores at 2 years.

Conclusions

Morphine treatment and prematurity were risk factors for altered VEPs parameters at TEA. In our cohort VEP morphology did not predict neurological outcome.

Significance

Morphine administration should be evaluated according to potential risks and benefits, and dosage individually accustomed, according to pain and comfort scores, considering the possible risk for neurodevelopmental impairment.

Airway disease decreases the therapeutic potential of epithelial stem cells

BACKGORUND

Tissue-engineered tracheal grafts (TETG) can be recellularized by the host or pre-seeded with host-derived cells. However, the impact of airway disease on the recellularization process is unknown.

METHODS

In this study, we determined if airway disease alters the regenerative potential of the human tracheobronchial epithelium (hTBE) obtained by brushing the tracheal mucosa during clinically-indicated bronchoscopy from 48 pediatric and six adult patients.

RESULTS

Our findings revealed that basal cell recovery and frequency did not vary by age or region. At passage 1, all samples produced enough cells to cellularize a 3.5 by 0.5 cm2 graft scaffold at low cell density (~ 7000 cells/cm2), and 43.75% could cellularize a scaffold at high cell density (~ 100,000 cells/cm2). At passage 2, all samples produced the number of cells required for both recellularization models. Further evaluation revealed that six pediatric samples (11%) and three (50%) adult samples contained basal cells with a squamous basal phenotype. These cells did not form a polarized epithelium or produce differentiated secretory or ciliated cells. In the pediatric population, the squamous basal cell phenotype was associated with degree of prematurity (< 28 weeks, 64% vs. 13%, p = 0.02), significant pulmonary history (83% vs. 34%, p = 0.02), specifically with bronchopulmonary dysplasia (67% vs. 19%, p = 0.01), and patients who underwent previous tracheostomy (67% vs. 23%, p = 0.03).

CONCLUSIONS

In summary, screening high-risk pediatric or adult population based on clinical risk factors and laboratory findings could define appropriate candidates for airway reconstruction with tracheal scaffolds.

LEVEL OF EVIDENCE

Level III Cohort study.

Nutritional Needs of the Infant with Bronchopulmonary Dysplasia

Growth failure is a common problem in infants with established bronchopulmonary dysplasia (BPD). Suboptimal growth for infants with BPD is associated with unfavorable respiratory and neurodevelopmental outcomes; however, high-quality evidence to support best nutritional practices are limited for this vulnerable patient population. Consequently, there exists a wide variation in the provision of nutritional care and monitoring of growth for infants with BPD. Other neonatal populations at risk for growth failure, such as infants with congenital heart disease, have demonstrated improved growth outcomes with the creation and compliance of clinical protocols to guide nutritional management. Developing clinical protocols to guide nutritional management for infants with BPD may similarly improve long-term outcomes. Given the absence of high-quality trials to guide nutritional practice in infants with BPD, the best available evidence of systematic reviews and clinical recommendations can be applied to optimize growth and decrease variation in the care of these infants.

Necrotizing Enterocolitis and the Preterm Infant Microbiome

Preterm infants differ significantly from their term infant counterparts regarding bacterial colonization patterns related to maternal microbiota diversity, mode of delivery, feeding type, antibiotic exposure, and the environmental influences related to prolonged hospitalization in the neonatal intensive care unit (NICU). Necrotizing enterocolitis (NEC), a multifactorial intestinal disorder characterized by ischemic bowel disease, disproportionately impacts preterm infants and has a high disease burden. Recent studies in the basic, translational, and clinical scientific literature have advanced knowledge into this complex disease process. Despite the explosion of research into NEC, however, there is a still a great deal unknown about this devastating illness. Additionally, the disease morbidity and mortality for NEC remain high despite advances in therapy options. This chapter reviews the current literature into the preterm infant microbiome, pathogenesis of NEC, potential targets for altering preterm microbiome, influence of microbiome on other organ systems, long-term implications of microbiome dysbiosis, and future directions of study.

Extrauterine growth restriction and low energy intake during the early neonatal period of very low birth weight infants are associated with decreased lung function in childhood

Premature birth, bronchopulmonary dysplasia or restrictive nutrition in the first weeks of postnatal life may have repercussions on lung development and affect long-term lung function outcomes. This prospective observational study is based on a cohort of 313 very low birth weight (VLBW) neonates, born between 1 January 2008 and 1 December 2016. The daily intake of calories, protein, fat and carbohydrates during the first week of life and evidence of inadequate weight gain (Δwt) until week 36 of gestational age (GA) were recorded. FEV1, FEF25-75 %, forced vital capacity (FVC) and the FEV1/FVC ratio were determined. The relations between these parameters were determined by regression analysis. Spirometric parameters were obtained for 141 children with a mean age of 9 years (95 % CI 7, 11); 69 of them (48·9 %) had presented wheezing episodes on more than three occasions. In addition, 60 (42·5 %) had a history of bronchopulmonary dysplasia. Of these, n 40 (66·6 %) had a history of wheezing. Significant association between protein/energy intake in the first week of life and the lung function parameters analysed was observed. Poor Δwt to GA week 36 was significantly associated with decreased mean pulmonary flow. Inadequate protein/energy intake in the first week of life of VLBW newborns and poor Δwt to week 36 of GA is associated with a significant worsening of lung function parameters.

Association between plasma lysophosphatidic acid levels and bronchopulmonary dysplasia in extremely preterm infants: A prospective study

BACKGROUND

Lysophosphatidic acid (LPA) is implicated in bronchopulmonary dysplasia (BPD) pathogenesis, but clinical evidence is lacking. This study aimed to investigate LPA levels in preterm infants with and without BPD and explore LPA as a biomarker for predicting BPD occurrence.

METHODS

Premature infants with a gestational age of <28 weeks or a birth weight of <1000 g were enrolled. Blood samples were collected at postnatal day (PD) 7, 28, and postmenstrual age (PMA) 36 weeks, and plasma LPA levels were measured using a commercial ELISA kit. Receiver operating characteristic curve (ROC) curve analysis determined the PD 28 cutoff for LPA, and multivariable regression analyzed LPA's independent contribution to BPD and exploratory outcomes.

RESULT

Among the 91 infants enrolled in this study, 35 were classified into the non-BPD group and 56 into the BPD group. Infants with BPD had higher plasma LPA levels at PD 28 (6.467 vs. 4.226 μg/mL, p = 0.034) and PMA 36 weeks (2.330 vs. 1.636 μg/mL, p = 0.001). PD 28 LPA level of 6.132 μg/mL was the cutoff for predicting BPD development. Higher PD 28 LPA levels (≥6.132 μg/mL) independently associated with BPD occurrence (OR 3.307, 95% CI 1.032-10.597, p = 0.044). Higher LPA levels correlated with longer oxygen therapy durations [regression coefficients (β) 0.147, 95% CI 0.643-16.133, p = .034].

CONCLUSIONS

Infants with BPD had higher plasma LPA levels at PD 28 and PMA 36 weeks. Higher PD 28 LPA levels independently associated with an increased BPD risk.

Irisin alleviates hyperoxia-induced bronchopulmonary dysplasia through activation of Nrf2/HO-1 pathway

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a common pulmonary injury among premature infants, which is often caused by hyperoxia exposure. Irisin is a novel hormone-like myokine derived mainly from skeletal muscles as well as adipose tissues. Many studies have indicated that Irisin exert a variety of properties against hyperoxia-induced inflammation and oxidative stress (OS). We aimed to evaluate the effects of irisin on hyperoxia-induced lung injury explore the underlying mechanisms.

METHODS

BPD model was established after exposing newborn mouse to 85% oxygen. BPD mouse received continuous intraperitoneal injection of irisin at a dose of 25 μg/kg/day. Lung tissues were collected for histological examination at 7 and 14 days after birth. The alveolarization and alveolar vascularization of each animal was assessed. Levels of oxidative stress indicators, and the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in lung tissues were detected at 14 days after birth.

RESULTS

Hyperoxia exposure induced a markedly alveolar simplification and a disrupted alveolar angiogenesis, which was ameliorated by irisin treatment. The hyperoxia-induced increase in these oxidative stress indicators was significantly reversed by irisin treatment. The Nrf2/HO-1 pathway is inducted in the hyperoxia-induced BPD mouse model, which is further activated by irisin treatment.

CONCLUSION

Our results demonstrated the beneficial effects of irisin in reducing the OS, enhancing alveolarization, and promoting vascular development through activation of Nrf2/HO-1 axis in a hyperoxia-induced experimental model of BPD.

Rapamycin attenuates pyroptosis by suppressing mTOR phosphorylation and promoting autophagy in LPS-induced bronchopulmonary dysplasia

PURPOSE/AIM

Bronchopulmonary dysplasia (BPD) is associated with poor survival in preterm infants. Intrauterine infection can aggravate the degree of obstruction of alveolar development in premature infants; however, the pathogenic mechanism remains unclear. In this study, we sought to determine whether pyroptosis could be inhibited by downregulating mammalian target of rapamycin (mTOR) activation and inducing autophagy in BPD-affected lung tissue.

MATERIALS AND METHODS

We established a neonatal rat model of BPD induced by intrauterine infection via intraperitoneally injecting pregnant rats with lipopolysaccharide (LPS). Subsequently, mTOR levels and pyroptosis were evaluated using immunohistochemistry, immunofluorescence, TUNEL staining, and western blotting. The Shapiro-Wilk test was employed to assess the normality of the experimental data. Unpaired t-tests were used to compare the means between two groups, and comparisons between multiple groups were performed using analysis of variance.

RESULTS

Pyroptosis of lung epithelial cells increased in BPD lung tissues. After administering an mTOR phosphorylation inhibitor (rapamycin) to neonatal rats with BPD, the level of autophagy increased, while the expression of autophagy cargo adaptors, LC3 and p62, did not differ. Following rapamycin treatment, NLRP3, Pro-caspase-1, caspase-1, pro-IL-1β, IL-1β, IL-18/Pro-IL-18, N-GSDMD/GSDMD, Pro-caspase-11, and caspase-11 were negatively regulated in BPD lung tissues. The opposite results were observed after treatment with the autophagy inhibitor MHY1485, showing an increase in pyroptosis and a significant decrease in the number of alveoli in BPD.

CONCLUSIONS

Rapamycin reduces pyroptosis in neonatal rats with LPS-induced BPD by inhibiting mTOR phosphorylation and inducing autophagy; hence, it may represent a potential therapeutic for treating BPD.

Pulmonary phenotypes of bronchopulmonary dysplasia in the preterm infant

Bronchopulmonary dysplasia (BPD) remains the most common complication of premature birth, imposing a significant and potentially life-long burden on patients and their families. Despite advances in our understanding of the mechanisms that contribute to patterns of lung injury and dysfunctional repair, current therapeutic strategies remain non-specific with limited success. Contemporary definitions of BPD continue to rely on clinician prescribed respiratory support requirements at specific time points. While these criteria may be helpful in broadly identifying infants at higher risk of adverse outcomes, they do not offer any precise information regarding the degree to which each compartment of the lung is affected. In this review we will outline the different pulmonary phenotypes of BPD and discuss important features in the pathogenesis, clinical presentation, and management of these frequently overlapping scenarios.

Consequences of Preterm Birth: Knowns, Unknowns, and Barriers to Advancing Cardiopulmonary Health

Preterm birth occurs in 10% of all live births and creates challenges to neonatal life, which persist into adulthood. Significant previous work has been undertaken to characterize and understand the respiratory and cardiovascular sequelae of preterm birth, which are present in adulthood, i.e., "late" outcomes. However, many gaps in knowledge are still present and there are several challenges that will make filling these gaps difficult. In this perspective we discuss the obstacles of studying adults born preterm, including (1) the need for invasive (direct) measures of physiologic function; (2) the need for multistate, multinational, and diverse cohorts; (3) lack of socialized medicine in the United States; (4) need for detailed and better-organized birth records; and (5) transfer of neonatal and pediatric knowledge to adult care physicians. We conclude with a discussion on the "future" of studying preterm birth in regards to what may happen to these individuals as they approach middle and older age and how the improvements in perinatal and postnatal care may be changing the phenotypes observed in adults born preterm on or after the year 2000.

Recent Advances in Pediatric Pulmonary Hypertension: Implications for Diagnosis and Treatment

PURPOSE

Pediatric pulmonary hypertension (PH) is a condition characterized by elevated pulmonary arterial pressure, which has the potential to be life-limiting. The etiology of pediatric PH varies. When compared with adult cohorts, the etiology is often multifactorial, with contributions from prenatal, genetic, and developmental factors. This review aims to provide an up-to-date overview of the causes and classification of pediatric PH, describe current therapeutics in pediatric PH, and discuss upcoming and necessary research in pediatric PH.

METHODS

PubMed was searched for articles relating to pediatric pulmonary hypertension, with a particular focus on articles published within the past 10 years. Literature was reviewed for pertinent areas related to this topic.

FINDINGS

The evaluation and approach to pediatric PH are unique when compared with that of adults, in large part because of the different, often multifactorial, causes of the disease in children. Collaborative registry studies have found that the most common disease causes include developmental lung disease and subsets of pulmonary arterial hypertension, which includes genetic variants and PH associated with congenital heart disease. Treatment with PH-targeted therapies in pediatrics is often guided by extrapolation of adult data, small clinical studies in pediatrics, and/or expert consensus opinion. We review diagnostic considerations and treatment in some of the more common pediatric subpopulations of patients with PH, including developmental lung diseases, congenital heart disease, and trisomy 21.

IMPLICATIONS

The care of pediatric patients with PH requires consideration of unique pediatric-specific factors. With significant variability in disease etiology, ongoing efforts are needed to optimize treatment strategies based on disease phenotype and guide evidence-based practices.

Quercetin supplementation attenuates airway hyperreactivity and restores airway relaxation in rat pups exposed to hyperoxia

Hyperoxia exposure of immature lungs contributes to lung injury and airway hyperreactivity. Up to now, treatments of airway hyperreactivity induced by hyperoxia exposure have been ineffective. The aim of this study was to investigate the effects of quercetin on hyperoxia-induced airway hyperreactivity, impaired relaxation, and lung inflammation. Newborn rats were exposed to hyperoxia (FiO2 > 95%) or ambient air (AA) for seven days. Subgroups were injected with quercetin (10 mg·kg-1·day-1). After exposures, tracheal cylinders were prepared for in vitro wire myography. Contraction to methacholine was measured in the presence or absence of organ bath quercetin and/or Nω-nitro-L-arginine methyl ester (L-NAME). Relaxation responses were evoked in preconstricted tissues using electrical field stimulation (EFS). Lung tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) levels were measured by enzyme-linked immunosorbent assay (ELISA). A P < 0.05 was considered statistically significant. Contractile responses of tracheal smooth muscle (TSM) of hyperoxic animals were significantly increased compared with AA animals (P < 0.001). Treatment with quercetin significantly reduced contraction in hyperoxic groups compared with hyperoxic control (P < 0.01), but did not have any effect in AA groups. In hyperoxic animals, relaxation of TSM was significantly reduced compared with AA animals (P < 0.001), while supplementation of quercetin restored the lost relaxation in hyperoxic groups. Incubation of preparations in L-NAME significantly reduced the quercetin effects on both contraction and relaxation (P < 0.01). Treatment of hyperoxic animals with quercetin significantly decreased the expression of TNF-α and IL-1β compared with hyperoxic controls (P < 0.001 and P < 0.01, respectively).The findings of this study demonstrate the protective effect of quercetin on airway hyperreactivity and suggest that quercetin might serve as a novel therapy to prevent and treat neonatal hyperoxia-induced airway hyperreactivity and inflammation.