Modern pulmonary imaging of bronchopulmonary dysplasia

Improving early diagnosis of bronchopulmonary dysplasia

INTRODUCTION

Bronchopulmonary disease (BPD) is associated with long-term neurodevelopmental and cardiorespiratory complications, often requiring significant use of resources. To reduce this healthcare burden, it is essential that those at high risk of BPD are identified early so that strategies are introduced to prevent disease progression. Our aim was to discuss potential methods for improving early diagnosis in the first week after birth.

AREAS COVERED

A narrative review was undertaken. The search strategy involved searching PubMed, Embase and Cochrane databases from 1967 to 2024. The results of potential biomarkers and imaging modes are discussed. Furthermore, the value of scoring systems is explored.

EXPERT OPINION

BPD occurs as a result of disruption to pulmonary vascular and alveolar development, thus abnormal levels of factors regulating those processes are promising avenues to explore with regard to early detection of high-risk infants. Data from twin studies suggests genetic factors can be attributed to 82% of the observed difference in moderate to severe BPD, but large genome-wide studies have yielded conflicting results. Comparative studies are required to determine which biomarker or imaging mode may most accurately diagnose early BPD development. Models which include the most predictive factors should be evaluated going forward.

Dynamic computed tomography for evaluation of tracheobronchomalacia in premature infants with bronchopulmonary dysplasia

INTRODUCTION

Dynamic computed tomography (dCT) gives real-time physiological information and objective descriptions of airway narrowing in tracheobronchomalacia (TBM). There is a paucity of literature in the evaluation of TBM by dCT in premature infants with bronchopulmonary dysplasia (BPD). The aim of this study is to describe the findings of dCT and resultant changes in management in premature infants with TBM.

METHODS

A retrospective study of 70 infants was performed. Infants included were <32 weeks gestation without major anomalies. TBM was defined as ≥50% expiratory reduction in cross-sectional area with severity defined as mild (50%-75%), moderate (≥75%-90%), or severe (≥90%).

RESULTS

Dynamic CT diagnosed malacia in 53% of infants. Tracheomalacia was identified in 49% of infants with severity as 76% mild, 18% moderate, and 6% severe. Bronchomalacia was identified in 43% of infants with varying severity (53% mild, 40% moderate, 7% severe). Resultant management changes included PEEP titration (44%), initiation of bethanechol (23%), planned tracheostomy (20%), extubation trial (13%), and inhaled ipratropium bromide (7%).

CONCLUSION

Dynamic CT is a useful noninvasive diagnostic tool for airway evaluation of premature infants. Presence and severity of TBM can provide actionable information to guide more precise clinical decision making.

Integration of transcriptomics reveals ferroptosis-related signatures and immune cell infiltration in bronchopulmonary dysplasia

Ferroptosis has emerged as a significant factor in the development of bronchopulmonary dysplasia (BPD). Nevertheless, our understanding of the potential involvement of ferroptosis-related genes (FRGs) in BPD remains incomplete. In this study, we leveraged the Gene Expression Omnibus (GEO) database to investigate this aspect. We identified 20 differentially expressed FRGs that are associated with BPD, shedding light on their potential role in the condition.LASSO along with SVM-RFE algorithms found that 12 genes: MEG3, ACSL1, DPP4, GALNT14, MAPK14, CD82, SMPD1, NR1D1, PARP3, ACVR1B, H19, and SLC7A11 were closely related to ferroptosis modulation and immunological response. These genes were used to create a nomogram with good predictive power and were found to be involved in BPD-linked pathways. In addition, the marker genes-based prediction model performed well in external validation data sets. The study also showed a significance between BPD and control samples in terms of immune cell infiltration. These findings may help improve our understanding of FRGs in BPD and lead to the development of more effective immunotherapies.

Monitoring and Management of Respiratory Function in Pompe Disease: Current Perspectives

Pompe disease (PD) is a neuromuscular disorder caused by a deficiency of acid alpha-glucosidase (GAA) - a lysosomal enzyme responsible for hydrolyzing glycogen. GAA deficiency leads to accumulation of glycogen in lysosomes, causing cellular disruption. The severity of PD is directly related to the extent of GAA deficiency - if no or minimal GAA is produced, symptoms are severe and manifest in infancy, known as infantile onset PD (IOPD). If left untreated, infants with IOPD experience muscle hypotonia and cardio-respiratory failure leading to significant morbidity and mortality in the first year of life. In contrast, late-onset PD (LOPD) patients have more GAA activity and present later in life, but also have significant respiratory function decline. Despite FDA-approved enzyme replacement therapy, respiratory insufficiency remains a major cause of morbidity and mortality, emphasizing the importance of early detection and management of respiratory complications. These complications include impaired cough and airway clearance, respiratory muscle weakness, sleep-related breathing issues, and pulmonary infections. This review aims to provide an overview of the respiratory pathology, monitoring, and management of PD patients. In addition, we discuss the impact of novel approaches and therapies on respiratory function in PD.

The argument for utilising magnetic resonance imaging as a tool for monitoring lung structure and function in pediatric patients

INTRODUCTION

Although historically challenging to perform in the lung, technological advancements have made Magnetic Resonance Imaging (MRI) increasingly applicable for pediatric pulmonary imaging. Furthermore, a wide array of functional imaging techniques has become available that may be leveraged alongside structural imaging for increasingly sensitive biomarkers, or as outcome measures in the evaluation of novel therapies.

AREAS COVERED

In this review, recent technical advancements and modern methodologies for structural and functional lung MRI are described. These include ultrashort echo time (UTE) MRI, free-breathing contrast agent-free, functional lung MRI, and hyperpolarized gas MRI, amongst other techniques. Specific examples of the application of these methods in children are provided, principally drawn from recent research in asthma, bronchopulmonary dysplasia, and cystic fibrosis.

EXPERT OPINION

Pediatric lung MRI is rapidly growing, and is well poised for clinical utilization, as well as continued research into early disease detection, disease processes, and novel treatments. Structure/function complementarity makes MRI especially attractive as a tool for increased adoption in the evaluation of pediatric lung disease. Looking toward the future, novel technologies, such as low-field MRI and artificial intelligence, mitigate some of the traditional drawbacks of lung MRI and will aid in improving access to MRI in general, potentially spurring increased adoption and demand for pulmonary MRI in children.

Hyperinflation and its association with successful transition to home ventilator devices in infants with chronic respiratory failure and severe bronchopulmonary dysplasia

OBJECTIVE

To estimate the association between lung hyperinflation and the time to successful transition to home ventilators in infants with sBPD and chronic respiratory failure.

DESIGN/METHODS

Infants with sBPD <32 weeks' gestation who received tracheostomies were identified. Hyperinflation was the main exposure. Time from tracheostomy to successful transition to the home ventilator was the main outcome. Kaplan-Meier and multivariable Cox proportional hazards were used to estimate the relationships between hyperinflation and the main outcome.

RESULTS

Sixty-two infants were included; 26 (42%) were hyperinflated. Eleven died before transition, and 51 successfully transitioned. Hyperinflation was associated with both mortality (31% vs 8.3%, p = 0.02) and an increased duration (72 vs. 56 days) to successful transition (hazard ratio (HR) = 0.38, 95% CI: 0.19, 0.76, p = 0.006). Growth velocity was similar after tracheostomy placement.

CONCLUSIONS

In infants with chronic respiratory failure and sBPD <32 weeks' gestation, hyperinflation is related to mortality and inpatient morbidities.

Assessment of lung ventilation of premature infants with bronchopulmonary dysplasia at 1.5 Tesla using phase-resolved functional lung magnetic resonance imaging

BACKGROUND

The most common chronic complication of preterm birth is bronchopulmonary dysplasia (BPD), widely referred to as chronic lung disease of prematurity. All current definitions rely on characterizing the disease based on respiratory support level and do not provide full understanding of the underlying cardiopulmonary pathophysiology.

OBJECTIVE

To evaluate a rapid functional lung imaging technique in premature infants and to quantitate pulmonary ventilation using 1.5 Tesla magnetic resonance imaging (MRI).

MATERIALS AND METHODS

We conducted a prospective MRI study of 12 premature infants in the neonatal intensive care unit (NICU) using the phase resolved functional lung MRI technique to calculate pulmonary ventilation parameters in preterm infants with and without BPD grade 0/1 (n = 6) and grade 2/3 (n = 6).

RESULTS

The total ventilation defect percentage showed a significant difference between groups (16.0% IQR (11.0%,18%) BPD grade 2/3 vs. 8.0% IQR (4.5%,9.0%) BPD grade 0/1, p = 0.01).

CONCLUSION

Phase-resolved functional lung MRI is feasible for assessment of ventilation defect percentages in preterm infants and shows regional variation in localized lung function in this population.

Identification and immunological characterization of endoplasmic reticulum stress-related molecular subtypes in bronchopulmonary dysplasia based on machine learning

Introduction: Bronchopulmonary dysplasia (BPD) is a life-threatening lung illness that affects premature infants and has a high incidence and mortality. Using interpretable machine learning, we aimed to investigate the involvement of endoplasmic reticulum (ER) stress-related genes (ERSGs) in BPD patients. Methods: We evaluated the expression profiles of endoplasmic reticulum stress-related genes and immune features in bronchopulmonary dysplasia using the GSE32472 dataset. The endoplasmic reticulum stress-related gene-based molecular clusters and associated immune cell infiltration were studied using 62 bronchopulmonary dysplasia samples. Cluster-specific differentially expressed genes (DEGs) were identified utilizing the WGCNA technique. The optimum machine model was applied after comparing its performance with that of the generalized linear model, the extreme Gradient Boosting, the support vector machine (SVM) model, and the random forest model. Validation of the prediction efficiency was done by the use of a calibration curve, nomogram, decision curve analysis, and an external data set. Results: The bronchopulmonary dysplasia samples were compared to the control samples, and the dysregulated endoplasmic reticulum stress-related genes and activated immunological responses were analyzed. In bronchopulmonary dysplasia, two distinct molecular clusters associated with endoplasmic reticulum stress were identified. The analysis of immune cell infiltration indicated a considerable difference in levels of immunity between the various clusters. As measured by residual and root mean square error, as well as the area under the curve, the support vector machine machine model showed the greatest discriminative capacity. In the end, an support vector machine model integrating five genes was developed, and its performance was shown to be excellent on an external validation dataset. The effectiveness in predicting bronchopulmonary dysplasia subtypes was further established by decision curves, calibration curves, and nomogram analyses. Conclusion: We developed a potential prediction model to assess the risk of endoplasmic reticulum stress subtypes and the clinical outcomes of bronchopulmonary dysplasia patients, and our work comprehensively revealed the complex association between endoplasmic reticulum stress and bronchopulmonary dysplasia.

Imaging in neonatal respiratory disease

The purpose of this review is to describe the current state of the art in clinical imaging for NICU patients, divided into major areas that correspond to likely phenotypes of neonatal respiratory disease: airway abnormalities, parenchymal disease, and pulmonary vascular disease. All common imaging modalities (ultrasound, X-ray, CT, and MRI) are discussed, with an emphasis on modalities that are most relevant to the individual underlying aspects of disease. Some promising aspects of dynamic and functional imaging are included, where there may be future clinical applicability.

Long term outcome of babies with pulmonary hypertension

Neonatal pulmonary hypertension (PH) is associated with many severe congenital abnormalities (congenital diaphragmatic hernia) or acquired cardiorespiratory diseases such as pneumonia, meconium aspiration and bronchopulmonary dysplasia (BPD). If no cause is found it may be labelled idiopathic persistent pulmonary hypertension of the newborn. Although PH may result in life threatening hypoxia and circulatory failure, in the majority of cases, it resolves in the neonatal period following treatment of the underlying cause. However, in some cases, neonatal PH progresses into infancy and childhood where symptoms include failure to thrive and eventually right heart failure or death if left untreated. This chronic condition is termed pulmonary vascular hypertensive disease (PHVD). Although classification and diagnostic criteria have only recently been proposed for pediatric PHVD, little is known about the pathophysiology of chronic neonatal PH, or why pulmonary vascular resistance may remain elevated well beyond infancy. This review explores the many factors involved in chronic PH and what implications this may have on long term outcome when the disease progresses beyond the neonatal period.