Shaili Amatya

Bronchopulmonary dysplasia (BPD) is a serious and often lethal complication of preterm birth that typically manifests about 1 mo after preterm delivery. The lungs of premature infants are underdeveloped and vulnerable to mechanical damage, inflammation, and oxidative stress. Collectively, these stressors impair the normal alveolarization of the premature lungs after birth. The multifactorial pathophysiology of BPD necessitates the identification of the molecular factors that mediate cell-to-cell communication that discriminates normal lung development from progression to BPD. Extracellular vesicles (EVs) mediate intercellular cross talk by transporting functional molecules, including proteins and nucleic acids, to recipient cells through biological fluids. This feasibility study determined the utility of profiling the discarded plasma-derived EV proteome to predict BPD susceptibility risk in extremely preterm infants. Discarded plasma was obtained from routine laboratory draws from infants born at less than 32 wk of gestation and weighing less than 1,500 g. Plasma EVs were captured using a magnetic bead-based immunoaffinity method. Subsequently, mass spectrometry and differential protein content analysis workflow identified a novel nine-EV-protein signature [APOD, heterogenous nuclear ribonucleoprotein M (HNRNPM), high-mobility group nucleosome-binding domain-containing protein 2 (HMGN2), intelectin-1 (ITLN1), proteinase 3 (PRTN3), RNA-binding protein4 (RBM4), RNA-binding motif protein, X chromosome (RBMX), TATA-binding protein-associated factor 2 N (TAF15, transcription elongation regulator 1 (TCERG1)] that distinguished preterm infants who developed BPD from those who did not. Application of machine learning statistical modeling using Promor tool trained on the nine-protein signature template identified a high specificity and selectivity prognostic threshold for the development of BPD. HNRNPM emerged as the most consistent biological response component predicting development of BPD in our patient cohort. Our study suggests that circulating EVs derived from discarded plasma are a suitable “liquid biopsy” to help stratify the vulnerability risk for BPD in preterm infants.

Background: CPAP benefits preterm infants with respiratory distress, including reduced bronchopulmonary dysplasia (BPD) incidence, surfactant use, and extubation failure. Successful CPAP weaning also promotes oral feeding. However, there is no consensus on the optimal weaning of CPAP in neonates. This study aimed to determine the effects of CPAP weaning guideline implementation on neonatal outcomes. Methods: CPAP gradual pressure weaning guidelines were implemented in the Penn State Children’s Hospital neonatal ICU in 2020. We included baseline data from infants (epoch 1) before guideline implementation in 2018–2019. We included infants (epoch 2) after implementing the guidelines during 2020–2021. The inclusion criteria were infants < 32 weeks gestation with CPAP support. Adherence with the CPAP weaning guidelines was the primary process measure. Primary outcome measures included successful CPAP wean on the first attempt. Balancing measures used were total days on respiratory support and hospital length of stay. Results: One hundred ninety-five infants were included in this study, 95 infants in epoch 1 before guideline implementation and 100 infants in epoch 2 after implementing guidelines. Infants in the 2 epochs were similar in median gestational age at 29 weeks versus 30 weeks ( P = .47) and were similar in median birthweight at 1,190 g versus 1,130 g ( P = .73). After implementing weaning guidelines, the successful weaning off CPAP improved from 9.5% to 54% ( P < .001). The total days needed to achieve full oral feeds decreased by 7 d (29 median d vs 22 median d, P < .001). The BPD incidence was not significantly different between the 2 epochs at 17% versus 16%, P = .87. There was no difference in total days of respiratory support, total length of stay, the number of infants discharged on home nasogastric feeding, and demographic variables. Conclusions: The implementation of the bubble CPAP weaning guideline improved the successful weaning of CPAP and promoted oral feeding in preterm infants.

Bronchopulmonary dysplasia (BPD) is a condition of poor alveolar formation that causes chronic breathing impairment in infants born prematurely. Preterm lungs lack surfactant and are vulnerable to oxidative injuries driving the development of BPD. Our recent studies reported that surfactant protein A (SP-A) genetic variants influence susceptibility to neonatal lung disease. SP-A modulates activation of alveolar macrophages and parturition onset in late gestation. We asked whether a lack of SP-A alters alveolarization in a mouse model of hyperoxia-induced BPD. SP-A-deficient and control newborn mice were exposed to either clinically relevant 60% O₂ hyperoxia or normoxia for 5–7 days. Alveolar formation was then assessed by mean linear intercept (MLI) and radial alveolar count (RAC) measurements in lung tissue sections. We report that the combination of SP-A deficiency and hyperoxia reduces alveolar growth compared to WT mice. The morphometric analysis of normoxic SP-A-deficient lungs showed lower RAC compared to controls, indicating reduced alveolar number. In the presence of hyperoxia, MLI was higher in SP-A-deficient lungs compared to controls. Differences were statistically significant for female pups. Spatial proteomic profiling of lung tissue sections showed that hyperoxia caused a 4-fold increase in the DNA damage marker γH2Ax in macrophages of SP-A-deficient lungs compared to normoxia. Our short report suggests an important role for SP-A in perinatal lung development and the protection of lung macrophages from oxidant injury. These studies warrant future investigation to discern the temporal interaction of SP-A, gender, oxidant injury, and lung macrophages in perinatal alveolar formation and development of BPD.

Background-Bronchopulmonary dysplasia (BPD) is a condition of poor alveolar formation that causes chronic breathing impairment in infants born prematurely. Preterm lungs lack surfactant and are vulnerable to oxidative injuries driving the development of BPD. Our recent studies reported that surfactant protein A (SP-A) genetic variants influence susceptibility to neonatal lung disease. SP-A modulates activation of alveolar macrophages and parturition onset in late gestation. We asked whether a lack of SP-A alters alveolarization in a mouse model of hyperoxia-induced BPD. Methods- SP-A-deficient and control newborn mice were exposed to either clinically relevant 60% O2 hyperoxia or normoxia for 5-7 days. Alveolar formation was then assessed by mean linear intercept (MLI) and radial alveolar count (RAC) measurements in lung tissue sections. Results- We report that the combination of SP-A deficiency and hyperoxia reduces alveolar growth compared to WT mice. The morphometric analysis of normoxic SP-A-deficient lungs showed lower RAC compared to controls, indicating reduced alveolar number. In the presence of hyperoxia, MLI was higher in SP-A-deficient lungs compared to controls. Differences were statistically significant for female pups. Spatial proteomic profiling of lung tissue sections showed that hyperoxia caused a 4-fold increase in the DNA damage marker gammaH2Ax in macrophages of SP-A-deficient lungs compared to normoxia. Conclusions- Our short report suggests an important role for SP-A in perinatal lung development and in protecting lung macrophages from oxidant injury. These studies warrant future investigation to discern the temporal interaction of SP-A, gender, oxidant injury, and lung macrophages in perinatal alveolar formation and development of BPD.

Objective: This study investigates the effectiveness of extubation from conventional mechanical ventilation using an endotracheal tube (MVET) compared to synchronized non-invasive positive-pressure ventilation (sNIPPV) using neurally adjusted ventilatory assist (NAVA) and conventional non-invasive positive-pressure ventilation (NIPPV) in extremely low-birth-weight (ELBW) infants. Methods: An institutional review board (IRB) approved this study (#12175) to conduct a single-center randomized control trial including 60 ELBW infants assigned in a one-to-one computer-generated scheme to either sNIPPV using NAVA or NIPPV. The primary outcome involved the need for reintubation, and the secondary outcome involved the assessment of moderate/severe BPD, defined as an oxygen requirement at 36 weeks, as in #NCT03613987 (clinicaltrials.gov). Results: There were 60 ELBW infants enrolled and randomized. The overall gestational age was 26 (1.5) weeks, and the birth weight was 773 (157) g [mean (SD)]. There were no statistically significant differences between the NAVA and NIPPV patient characteristics. There was a 41% extubation failure rate in the NIPPV group and 35% in the NAVA group (p = NS). The NAVA group had less moderate and severe BPD (p = 0.03), a shorter oxygen therapy duration (p = 0.002), a decreased length of stay (p = 0.03), and less need for home oxygen (0, 43%; p = 0.0004). Conclusions: This study found similar extubation failure rates among ELBW infants as in prior studies. However, the NAVA group had lower rates of moderate/severe BPD and need for oxygen at discharge, as well as shorter oxygen therapy duration and length of stay. The use of NAVA may be a reasonable alternative mode of non-invasive ventilation in the ELBW population.

This perspective work by academic neonatal providers is written specifically for the audience of newborn care providers and neonatologists involved in neonatal hypoglycemia screening. Herein, we propose adding a screen for congenital hyperinsulinism (CHI) by measuring glucose and ketone (i.e., β-hydroxybutyrate (BOHB)) concentrations just prior to newborn hospital discharge and as close to 48 h after birth as possible, at the same time that the mandated state Newborn Dried Blood Spot Screen is obtained. In the proposed protocol, we do not recommend specific metabolite cutoffs, as our primary objective is to simply highlight the concept of screening for CHI in newborns to newborn caregivers. The premise for our proposed screen is based on the known effect of hyperinsulinism in suppressing ketogenesis, thereby limiting ketone production. We will briefly discuss genetic CHI, other forms of neonatal hypoglycemia, and their shared mechanisms; the mechanism of insulin regulation by functional pancreatic islet cell membrane K_ATP channels; adverse neurodevelopmental sequelae and brain injury due to missing or delaying the CHI diagnosis; the principles of a good screening test; how current neonatal hypoglycemia screening programs do not fulfill the criteria for being effective screening tests; and our proposed algorithm for screening for CHI in newborns.

Corrigendum: Single nucleotide polymorphisms interactions of the surfactant protein genes associated with respiratory distress syndrome susceptibility in preterm infants

Background: MicroRNAs (miRNA) are small non-coding RNAs that regulate gene expression playing a key role in organogenesis. MiRNAs are studied in tracheal aspirates (TA) of preterm infants. However; this is difficult to obtain in infants who are not intubated. This study examines early salivary miRNA expression as non-invasive early biomarkers in extremely low gestational age newborns (ELGANs). Methods: Saliva was collected using DNA-genotek swabs, miRNAs were analyzed using RNA seq and RT PCR arrays. Salivary miRNA expression was compared to TA using RNA seq at 3 days of age, and longitudinal changes at 28 days of age were analyzed using RT PCR arrays in ELGANs. Results: Approximately 822 ng of RNA was extracted from saliva of 7 ELGANs; Of the 757 miRNAs isolated, 161 miRNAs had significant correlation in saliva and TA at 3 days of age (r = 0.97). Longitudinal miRNA analysis showed 29 miRNAs downregulated and 394 miRNAs upregulated at 28 days compared to 3 days of age (adjusted p < 0.1). Bioinformatic analysis (Ingenuity Pathway Analysis) of differentially expressed miRNAs identified organismal injury and abnormalities and cellular development as the top physiological system development and cellular function. Conclusion: Salivary miRNA expression are source for early biomarkers of underlying pathophysiology in ELGANs.