Current Status and Associated Factors of Post-Hemorrhagic Hydrocephalus in Infants of 22 to 28 Weeks Gestation With Severe Intraventricular Hemorrhage in Korea: A Nationwide Cohort Study

BACKGROUND

Post-hemorrhagic hydrocephalus (PHH), a common complication of severe intraventricular hemorrhage (IVH) in very low birth weight (BW) infants, is associated with significant morbidity and poor neurological outcomes. The objective of this study was to assess the current status of PHH and analyze the risk factors associated with the necessity of treatment for PHH in infants born between 22 and 28 weeks of gestation, specifically those with severe IVH (grade 3 or 4).

METHODS

The analysis was conducted on 1,097 infants who were born between 22-28 gestational weeks and diagnosed with severe IVH, using data from the Korean Neonatal Network. We observed that the prevalence of PHH requiring treatment was 46.3% in infants with severe IVH.

RESULTS

Higher rates of mortality, transfer during admission, cerebral palsy, and ventriculoperitoneal shunt after discharge were higher in infants with PHH than in those without PHH. PHH in severe IVH was associated with a higher rate of pulmonary hemorrhage, seizures, and IVH grade 4 in the entire cohort. In addition, it was associated with a lower rate of small for gestational age and chorioamnionitis. In the subgroup analysis, high BW, outborn status, pulmonary hemorrhage, seizure, sepsis, and IVH grade 4 were associated with a higher incidence of PHH between 22 and 25 gestational weeks (GW). In infants born between 26 and 28 GW, a higher incidence of PHH was associated with seizures and IVH grade 4.

CONCLUSION

It is necessary to maintain meticulous monitoring and neurological intervention for infants with PHH not only during admission but also after discharge. In addition, identifying the clinical factors that increase the likelihood of developing PHH from severe IVH is crucial.

Long-term impact of late pulmonary hypertension requiring medication in extremely preterm infants with severe bronchopulmonary dysplasia

This study investigated whether late pulmonary hypertension (LPH) independently increases the risk of long-term mortality or neurodevelopmental delay (NDD) in extremely preterm infants (EPIs) with severe bronchopulmonary dysplasia (BPD). Using prospectively collected data from the Korean Neonatal Network, we included EPIs with severe BPD born at 22-27 weeks' gestation between 2013 and 2021. EPIs having severe BPD with LPH (LPH, n = 124) were matched 1:3 with those without pulmonary hypertension (PH) as controls (CON, n = 372), via propensity score matching. LPH was defined as PH with the initiation of medication after 36 weeks' corrected age (CA). Long-term mortality after 36 weeks' CA or NDD at 18-24 months' CA was analyzed. NDD was assessed using composite scores based on various neurodevelopmental assessment modalities. LPH had significantly higher long-term mortality or NDD (45.2% vs. 23.1%, P < 0.001), mortality (24.2% vs. 4.84%, P < 0.001), and NDD (68.4% vs. 37.8%, P = 0.001), respectively than CON, even after adjusting for different demographic factors. Multivariable regression demonstrated that LPH independently increased the risk of mortality or NDD (adjusted odds ratio, 1.95; 95% confidence intervals, 1.17-3.25). When LPH occurs in EPIs with severe BPD, special monitoring and meticulous care for long-term survival and neurodevelopment are continuously needed.

Antenatal Magnesium Sulfate Is Not Associated With Improved Long-Term Neurodevelopment and Growth in Very Low Birth Weight Infants

BACKGROUND

Though antenatal magnesium sulfate (MgSO4) is widely used for fetal neuroprotection, suspicions about the long-term neuroprotection of antenatal MgSO4 have been raised.

METHODS

We investigated short- and long-term outcomes of antenatal MgSO4 use for 468 infants weighing < 1,500 g with a gestational age of 24-31 weeks.

RESULTS

Short-term morbidities and the risk of developmental delay, hearing loss, and cerebral palsy at a corrected age of 18-24 months and 3 years of age did not decrease in the MgSO4 group (infants who were exposed to MgSO4 for any purpose) or neuroprotection group (infants who were exposed to MgSO4 for fetal neuroprotection) compared with the control group (infants who were not exposed to MgSO4). The z-scores of weight, height, and head circumference did not increase in the MgSO4 group or neuroprotection group compared with the control group.

CONCLUSION

Antenatal MgSO4 including MgSO4 for neuroprotection did not have beneficial effects on long-term neurodevelopmental and growth outcomes.

Mesenchymal Stromal Cells Primed by Toll-like Receptors 3 and 4 Enhanced Anti-Inflammatory Effects against LPS-Induced Macrophages via Extracellular Vesicles

Although it has been suggested that toll-like receptor (TLR) 3 and TLR4 activation alters mesenchymal stromal cells (MSCs)' immunoregulatory function as anti- or pro-inflammatory phenotypes, we have previously confirmed that TLR4-primed hUCB-MSCs alleviate lung inflammation and tissue injury in an E. coli-induced acute lung injury (ALI) mouse model. Therefore, we hypothesized that strong stimulation of TLR3 or TLR4 prompts hUCB-MSCs to exhibit an anti-inflammatory phenotype mediated by extracellular vesicles (EVs). In this study, we compared the anti-inflammatory effect of TLR3-primed and TLR4-primed hUCB-MSCs against an LPS-induced ALI in vitro model by treating MSCs, MSC-derived conditioned medium (CM), and MSC-derived extracellular vesicles (EVs). LPS-induced rat primary alveolar macrophage and RAW 264.7 cells were treated with naïve, TLR3-, and TLR4-primed MSCs and their derived CM and EVs. Flow cytometry and ELISA were used to evaluate M1-M2 polarization of macrophages and pro-inflammatory cytokine levels, respectively. LPS-stimulated macrophages showed significantly increased pro-inflammatory cytokines compared to those of the normal control, and the percentage of M2 macrophage phenotype was predominantly low. In reducing the inflammatory cytokines and enhancing M2 polarization, TLR3- and TLR4-primed MSCs were significantly more effective than the naïve MSCs, and this finding was also observed with the treatment of MSC-derived CMs and EVs. No significant difference between the efficacy of TLR3- and TLR-primed MSCs was observed. Strong stimulation of TLR3- and TLR4-stimulated hUCB-MSCs significantly reduced pro-inflammatory cytokine secretion from LPS-induced macrophages and significantly enhanced the M2 polarization of macrophages. We further confirmed that TLR-primed MSC-derived EVs can exert anti-inflammatory and immunosuppressive effects alone comparable to MSC treatment. We hereby suggest that in the LPS-induced macrophage in vitro model, EVs derived from both TLR3 and TLR4-primed MSCs can be a therapeutic candidate by promoting the M2 phenotype.

Optimal Protocols and Management of Clinical and Genomic Data Collection to Assist in the Early Diagnosis and Treatment of Multiple Congenital Anomalies

Standardized protocols have been designed and developed specifically for clinical information collection and obtaining trio genomic information from infants affected with congenital anomalies (CA) and their parents, as well as securing human biological resources. The protocols include clinical and genomic information collection on multiple CA that were difficult to diagnose using pre-existing screening methods. We obtained human-derived resources and genomic information from 138 cases, including 45 families of infants with CA and their parent trios. For the clinical information collection protocol, criteria for target patient selection and a consent system for collecting and utilizing research resources are crucial. Whole genome sequencing data were generated for all participants, and standardized protocols were developed for resource collection and manufacturing. We recorded the phenotype information according to the Human Phenotype Ontology term, and epidemiological information was collected through an environmental factor questionnaire. Updating and recording of clinical symptoms and genetic information that have been newly added or changed over time are significant. The protocols enabled long-term tracking by including the growth and development status that reflect the important characteristics of newborns. Using these clinical and genetic information collection protocols for CA, an essential platform for early genetic diagnosis and diagnostic research can be established, and new genetic diagnostic guidelines can be presented in the near future.

Changes to Blood-Sampling Protocol to Reduce the Sampling Amount in Neonatal Intensive Care Units: A Quality Improvement Project

(1) Background: This study aimed to evaluate whether the implementation of a modified blood-sampling protocol, which focused on need-based laboratory testing and minimized venous sampling by replacing it with point-of-care testing (POCT) via capillary puncture, successfully reduced iatrogenic blood loss, incidence of anemia, and the frequency of blood transfusion among extremely low-birth-weight infants (ELBWIs) without negatively affecting neonatal outcomes. (2) Methods: A retrospective analysis was conducted on 313 ELBWIs with a gestational age (GA) of between 23 and 28 weeks and born between 2013 and 2019. The infants were divided into two groups corresponding to the periods before (period I) and after (period II) the implementation of the modified blood-sampling protocol in January 2016. Propensity score matching was conducted to minimize selection bias. Clinical data, including the frequency and amount of blood sampling, the frequency and volume of blood transfusion, and clinical characteristics, such as gestational age, birth weight, and neonatal outcome data, were collected and compared between the two groups. (3) Results: No significant differences in GA or birth weight between the two periods were observed. The total sampling volume a month after birth (16.7 ± 4.1 mL vs. 15.6 ± 4.4 mL, p = 0.03) and the total sampling volume during hospitalization days (51.4 ± 29.7 mL vs. 44.3 ± 27.5 mL, p = 0.04) in period II were significantly lower than those in period I. There were no differences in terms of anemia (hemoglobin 10.8 ± 2.2 vs. 11.0 ± 1.9, p = 0.43) and mortality or morbidity, such as intraventricular hemorrhage, retinopathy of prematurity, bronchopulmonary dysplasia, necrotizing enterocolitis, and sepsis, between the two periods. Although the transfusion frequency and amount did not present significant differences between the periods, we observed a positive correlation between the transfusion frequency and sampling volume (coefficient: 0.09, 95% CI: 0.08-0.11). (4) Conclusions: The modified blood-sampling protocol effectively reduced the level of iatrogenic blood loss without negatively affecting the neonatal outcomes.

SOCS3 Protein Mediates the Therapeutic Efficacy of Mesenchymal Stem Cells against Acute Lung Injury

Mesenchymal stem cells (MSCs) have been studied as novel therapeutic agents because of their immunomodulatory properties in inflammatory diseases. The suppressor of cytokine signaling (SOCS) proteins are key regulators of the immune response and macrophage modulation. In the present study, we hypothesized that SOCS in MCSs might mediate macrophage modulation and tested this in a bacteria-induced acute lung injury (ALI) mouse model. The macrophage phenotype was observed in RAW264.7 alveolar macrophages exposed to lipopolysaccharide (LPS) in an in vitro model, and in the ALI mouse model induced by tracheal administration of Escherichia coli (1 × 10⁷ CFU in 0.05mL PBS). In LPS-exposed RAW264.7 cells, the levels of markers of M1 macrophages, such as CD86 and pro-inflammatory cytokines (IL-1α, IL-1β, IL-6 and TNF-α), significantly increased, but they significantly reduced after MSC treatment. Meanwhile, the levels of markers of M2 macrophages, such as CD204 and anti-inflammatory cytokines (IL-4 and IL-10), increased after LPS exposure, and further significantly increased after MSC treatment. This regulatory effect of MSCs on M1/M2 macrophage polarization was significantly abolished by SOCS3 inhibition. In the E. coli-induced ALI model, tissue injury and inflammation in the mouse lung were significantly attenuated by the transplantation of MSCs, but not by SOCS3-inhibited MSCs. The regulatory effect of MSCs on M1/M2 macrophage polarization was observed in the lung injury model but was significantly abolished by SOCS3 inhibition. Taken together, our findings suggest that SOCS3 is an important mediator for macrophage modulation in anti-inflammatory properties of MSCs.

Comprehensive Evaluation of the NeoBase 2 Non-derivatized MSMS Assay and Exploration of Analytes With Significantly Different Concentrations Between Term and Preterm Neonates

Background

Despite the popularity of the NeoBase 2 Non-derivatized MSMS assay (PerkinElmer, Turku, Finland), there are no reports of its comprehensive evaluation, including the ability to distinguish transient tyrosinemia of the newborn (TTN) from tyrosinemia type 1 (TYR 1) using succinylacetone (SUAC). No newborn screening (NBS) cutoffs for preterm neonates in the Korean population have been suggested. We evaluated the NeoBase 2 assay and identified analytes requiring different cutoffs in preterm neonates.

Methods

Residual NBS dried blood spot samples and proficiency testing (PT) materials of the Newborn Screening Quality Assurance Program and the Korean Association of External Quality Assessment Service were used. Precision, accuracy, limit of detection (LOD), lower limit of quantification (LLOQ), linearity, recovery, carryover, and performance of SUAC were evaluated. Cutoffs were determined, and analytes requiring different cutoffs in preterm neonates were investigated.

Results

Mean CVs for within-run and between-day precision were within 15%. Accuracy analysis indicated high agreement with in-house derivatized assay results and results of other PT participants. All analytes demonstrated acceptable LOD, LLOQ, and linearity. Recoveries were acceptable, except for SUAC. Carryover was negligible. Cutoffs were established for all analytes; Tyr, adenosine, and C20:0-lysophosphatidylcholine required different cutoffs in preterm neonates. Differential diagnosis of TYR 1 and TTN was successful with simultaneous Tyr and SUAC measurement.

Conclusions

The NeoBase 2 assay demonstrated satisfactory performance. The additional analytes provide a wider diagnostic coverage, and the simultaneous measurement of Tyr and SUAC is efficient in excluding TYR 1. The new cutoffs for preterm neonates may decrease false-positive rates, without compromising diagnostic sensitivity.

Neonatal Intensive Care Quality Level-Dependent Variations in the Survival Rate of Infants with a Birth Weight of 500 g or Less in Korea: A Nationwide Cohort Study

OBJECTIVE

Recent evidence suggests that the survival of peri-viable infants with birth weight (BW) ≤500 g could be improved with better care practices in the neonatal intensive care unit (NICU). This study aimed to investigate the care quality level of NICU-dependent variations in the survival rate of infants with BW ≤500 g.

METHODS

To determine the quality of NICU care-dependent variations in the survival rate, 226 eligible infants of BW ≤500 g and ≥22 weeks gestation registered in the Korean Neonatal Network between 2013 and 2017 were grouped according to the survival rates of infants at 23-24 weeks gestation, reflecting the care quality level of each NICU as group I (≥50%, n = 107) and group II (<50%, n = 119).

RESULTS

The survival rate of group I infants (40.2%, 43/107) was significantly higher than that of group II infants (14.3%, 17/119). Significantly reduced deaths from birth to the age of 7 days due to cardiorespiratory causes were the primary contributors to improved survival. In multivariable Cox hazard model analyses, besides the gestational age and BW, antenatal steroid use, cesarean section, pH, and base excess at admission were associated with improved infant survival.

CONCLUSIONS

The survival rate of pre-viable infants with BW ≤500 g could be improved by providing better NICU quality care practices, including better cardiorespiratory management starting from delivery room resuscitation.

Early Discontinuation of Levothyroxine Treatment Is Safe and Feasible in Extremely Low Birth Weight Infants with Delayed Hyperthyrotropinemia

BACKGROUND

While recent pieces of evidence suggest that discontinuation of levothyroxine replacement therapy (LRT) earlier than the current guidelines of 3 years is possible, the optimal duration of LRT for delayed hyperthyrotropinemia in extremely low birth weight infants (ELBWIs) remains unknown.

OBJECTIVE

This study aimed to investigate the feasibility of early discontinuation of LRT for delayed hyperthyrotropinemia in ELBWIs.

METHODS

The medical records of 92 ELBWIs who had shown delayed hyperthyrotropinemia, defined as a delayed rise in thyroid-stimulating hormone (TSH) levels to >20 µIU/mL after initial normal TSH level, were retrospectively reviewed to determine whether the duration of LRT affects the short-term outcomes at discharge from neonatal intensive care unit (NICU) and the long-term outcomes at the corrected age (CA) of 2 years. The infants were grouped into: no LRT required group (n = 21), short-term LRT given until the time of NICU discharge - 90 ± 64 (13-211) days group (n = 36), and long-term LRT given - 749 ± 333 (339-1,967) days group (n = 35).

RESULTS

While mortality in the no LRT required group was significantly higher than that in the long-term LRT group, no significant differences were observed in short-term outcomes at discharge from NICU and long-term growth and neurodevelopmental outcomes at CA of 2 years between the short- and long-term LRT groups.

CONCLUSIONS

Termination of LRT at around the time of discharge from NICU in well, clinically stable ELBWIs who have delayed hyperthyrotropinemia appears to be safe and feasible and avoids the risk of overtreatment.

Effect of levothyroxine supplementation in extremely low birth weight infants with transient hypothyroxinemia of prematurity

This study aimed to determine the short- and/or long-term outcomes of levothyroxine replacement therapy in extremely low birth weight (ELBW) infants with transient hypothyroxinemia of prematurity (THOP). The medical records of 335 ELBW infants with THOP were reviewed retrospectively to identify whether levothyroxine treatment affects short- and/or long-term outcomes at a corrected age of 2 years. The infants were arbitrarily grouped based on thyroxine (T4) (free T4 [fT4]) levels into group 1 (n = 142), which included infants with T4 (fT4) levels < 2.5 (0.5) ng/dl, and group 2 (n = 193), which included those with T4 (fT4) levels ranging from ≥ 2.5 (0.5) ng/dl to < 4.5 (0.9) ng/dl. Levothyroxine replacement therapy was not associated with beneficial short- or long-term outcomes in ELBW infants with THOP. Short-term outcomes, such as mortality and composite morbidities, and long-term outcomes, such as failure to achieve catch-up height at a corrected age of 2 years, were significantly higher in group 1 than in group 2, regardless of levothyroxine treatment status. Levothyroxine replacement therapy is not associated with short-or long-term advantages in ELBW infants with THOP. This study suggests that the severity of THOP may be the major determinant of adverse outcomes in ELBW infants with THOP, rather than levothyroxine treatment.

Thrombin Preconditioning Improves the Therapeutic Efficacy of Mesenchymal Stem Cells in Severe Intraventricular Hemorrhage Induced Neonatal Rats

Severe intraventricular hemorrhage (IVH) remains a major cause of high mortality and morbidity in extremely preterm infants. Mesenchymal stem cell (MSC) transplantation is a possible therapeutic option, and development of therapeutics with enhanced efficacy is necessary. This study investigated whether thrombin preconditioning improves the therapeutic efficacy of human Wharton’s jelly-derived MSC transplantation for severe neonatal IVH, using a rat model. Severe neonatal IVH was induced by injecting 150 μL blood into each lateral ventricle on postnatal day (P) 4 in Sprague-Dawley rats. After 2 days (P6), naïve MSCs or thrombin-preconditioned MSCs (1 × 10⁵/10 μL) were transplanted intraventricularly. After behavioral tests, brain tissues and cerebrospinal fluid of P35 rats were obtained for histological and biochemical analyses, respectively. Thrombin-preconditioned MSC transplantation significantly reduced IVH-induced ventricular dilatation on in vivo magnetic resonance imaging, which was coincident with attenuations of reactive gliosis, cell death, and the number of activated microglia and levels of inflammatory cytokines after IVH induction, compared to naïve MSC transplantation. In the behavioral tests, the sensorimotor and memory functions significantly improved after transplantation of thrombin-preconditioned MSCs, compared to naïve MSCs. Overall, thrombin preconditioning significantly improves the therapeutic potential and more effectively attenuates brain injury, including progressive ventricular dilatation, gliosis, cell death, inflammation, and neurobehavioral functional impairment, in newborn rats with induced severe IVH than does naïve MSC transplantation.

Development of necrotizing enterocolitis in full-term infants with duct dependent congenital heart disease

Background

Although many studies have described an increased risk of necrotizing enterocolitis in duct dependent congenital heart diseases, very few have investigated its occurrence in full-term infants with duct dependent congenital heart diseases.

Methods

To evaluate the characteristics and risk factors of necrotizing enterocolitis, we performed a retrospective review of 355 full-term infants with duct dependent congenital heart diseases who received prostaglandin E1 therapy from April 2000 to May 2020.

Results

Necrotizing enterocolitis was observed in 10 patients (3.0%). Their average gestational age and birth weight were 38.2 weeks and 2783.5 g, respectively. The median age at diagnosis was 8.0 days (2–70 days). One patient was diagnosed with necrotizing enterocolitis stage IIA, five with stage IIB, two with stage IIIA, and two with stage IIIB; two (20%) received surgical treatment. The duct dependent pulmonary circulation group had higher frequencies of necrotizing enterocolitis (4.4%) than the duct dependent systemic circulation (2.0%) and parallel circulation (1.3%) groups. The necrotizing enterocolitis and the other groups had significantly different birth weight (2783.5 g vs 3170.9 g, respectively) and gestational age (38.2 weeks vs 39.1 weeks, respectively). Gestational age under 38 weeks (OR 8.87, p = 0.002), birth weight of < 2500 g (OR 5.1, p = 0.042), need for mechanical ventilation (OR 4.6, p = 0.021), parenteral nutrition (OR 107.7, p < 0.001), and functional single ventricle (OR 5.8, p = 0.009) were significant risk factors. The case-fatality rate was higher in the necrotizing enterocolitis (40.0%) than in the other group (8.3%, p = 0.009).

Conclusions

Three percent of full-term infants with duct dependent congenital heart diseases developed necrotizing enterocolitis. Neonates with low birth weight, gestational age less than 38 weeks, functional single ventricle, or receiving assisted mechanical ventilation or parenteral nutrition are at increased risk.

Increased Risk of Meconium-Related Ileus in Extremely Premature Infants Exposed to Antenatal Magnesium Sulfate

INTRODUCTION

We experienced an increased incidence of meconium-related ileus (MRI) in extremely premature infants (EPIs) while adopting the antenatal magnesium sulfate (MgSO4) protocol for fetal neuroprotection in our neonatal intensive care unit. This study aimed to test whether antenatal MgSO4 use was associated with increased risk of MRI in EPIs.

METHODS

The incidences of complicated MRI requiring aggressive enema or surgical intervention and other intestinal complications were compared among period 1 (January 2012-December 2013, n = 79), before adoption of the antenatal MgSO4 protocol for fetal neuroprotection; period 2 (January 2014-March 2016, n = 72), when the protocol was adopted; and period 3 (April 2016-September 2018, n = 75), when the protocol was temporarily withdrawn due to concern regarding intestinal complications in EPIs.

RESULTS

Despite similar baseline clinical characteristics among infants across the study periods, the MRI and MRI with surgical treatment incidences were higher in period 2 than those in periods 1 and 3 (13% vs. 8% and 6%, p = 0.391, and 11% vs. 0% and 1%, p = 0.001, respectively). In multivariable analysis, exposure to antenatal MgSO4 independently increased the risk of MRI (adjusted odds ratio, 3.8; 95% confidence interval, 1.4, 10.6).

CONCLUSION

Antenatal MgSO4 may increase the risk of MRI, frequently requiring surgical intervention, in EPIs with a gestational age of 25 weeks or less.

BDNF-Overexpressing Engineered Mesenchymal Stem Cells Enhances Their Therapeutic Efficacy against Severe Neonatal Hypoxic Ischemic Brain Injury

We investigated whether irradiated brain-derived neurotropic factor (BDNF)-overexpressing engineered human mesenchymal stem cells (BDNF-eMSCs) improve paracrine efficiency and, thus, the beneficial potency of naïve MSCs against severe hypoxic ischemic (HI) brain injury in newborn rats. Irradiated BDNF-eMSCs hyper-secreted BDNF > 10 fold and were >5 fold more effective than naïve MSCs in attenuating the oxygen-glucose deprivation-induced increase in cytotoxicity, oxidative stress, and cell death in vitro. Only the irradiated BDNF-eMSCs, but not naïve MSCs, showed significant attenuating effects on severe neonatal HI-induced short-term brain injury scores, long-term progress of brain infarct, increased apoptotic cell death, astrogliosis and inflammatory responses, and impaired negative geotaxis and rotarod tests in vivo. Our data, showing better paracrine potency and the resultant better therapeutic efficacy of the irradiated BDNF-eMSCs, compared to naïve MSCs, suggest that MSCs transfected with the BDNF gene might represent a better, new therapeutic strategy against severe neonatal HI brain injury.

Stem cells for bronchopulmonary dysplasia in preterm infants: A randomized controlled phase II trial

We previously demonstrated the safety and feasibility of mesenchymal stem cell (MSC) transplantation for bronchopulmonary dysplasia (BPD) in preterm infants in a phase I clinical trial. We thus investigated the therapeutic efficacy of MSCs for BPD in premature infants. A phase II double-blind, randomized, placebo-controlled clinical trial was conducted on preterm infants at 23 to 28 gestational weeks (GW) receiving mechanical ventilator support with respiratory deterioration between postnatal days 5 and 14. Infants were stratified by 23 to 24 GW and 25 to 28 GW and randomly allocated (1:1) to receive stem cells (1 × 10⁷ cells/kg, n = 33) or placebo (n = 33). Although the inflammatory cytokines in the tracheal aspirate fluid were significantly reduced with MSCs, the primary outcome of death or severe/moderate BPD in the control group (18/33, 55%) was not significantly improved with MSC transplantation (17/33, 52%). In the subgroup analysis, the secondary outcome of severe BPD was significantly improved from 53% (8/15) to 19% (3/16) with MSC transplantation in the 23 to 24 GW group but not in the 25 to 28 GW subgroup. In summary, although MSC transplantation might be safe and feasible, this small study was underpowered to detect its therapeutic efficacy in preterm infants at 23 to 28 GW. Accordingly, we are now conducting an additional larger and controlled phase II clinical trial focusing on infants at 23 to 24 GW (NCT03392467). ClinicalTrials.gov identifier: NCT01828957.

Mortality and Morbidities according to Time of Birth in Extremely Low Birth Weight Infants

BACKGROUND

Although the overall quality of high-risk neonatal care has improved recently, there is still concern about a difference in the quality of care when comparing off-hour births and regular-hour births. Moreover, there are no data in Korea regarding the impact of time of birth on mortality and morbidities in preterm infants.

METHODS

A total of 3,220 infants weighing < 1,000 g and born at 23-34 weeks in 2013-2017 were analyzed based on the Korean Neonatal Network data. Mortality and major morbidities were analyzed using logistic regression according to time of birth during off-hours (nighttime, weekend, and holiday) and regular hours. The institutes were sub-grouped into hospital group I and hospital group II based on the neonatal intensive care unit (NICU) care level defined by the mortality rates of < 50% and ≥ 50%, respectively, in infants born at 23-24 weeks' gestation.

RESULTS

The number of births during regular hours and off-hours was similar. In the total population and hospital group I, off-hour births were not associated with increased neonatal mortality and morbidities. However, in hospital group II, increased early mortality was found in the off-hour births when compared to regular-hour births.

CONCLUSION

Efforts to improve the overall quality of NICU are required to lower the early mortality rate in off-hour births. Also, other sensitive indexes for the evaluation of quality of NICU care should be further studied.

Mesenchymal stem cell therapy for intractable neonatal disorders

Mesenchymal stem cell (MSC) transplantation has emerged as a new promising therapeutic strategy for the treatment of intractable and devastating neonatal disorders with complex multifactorial etiologies, including bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), and hypoxic-ischemic encephalopathy (HIE). In response to inflammatory and noxious environments, MSCs secrete various paracrine factors that perform several reparative functions, including exerting anti-inflammatory, anti-oxidative, anti-apoptotic, and anti-fibrotic effects, to enhance the regeneration of damaged cells and tissues. In this review, we summarize recent advances in stem cell research focusing on the use of MSCs in the prevention and treatment of newborn BPD, IVH and HIE, with particular emphasis on preclinical and clinical data.

Fish Oil Monotherapy for Intestinal Failure-Associated Liver Disease on SMOFlipid in the Neonatal Intensive Care Unit

Intestinal failure-associated liver disease (IFALD) is a life-threatening complication of parenteral nutrition (PN) and is most prevalent in the preterm neonatal population receiving long-term PN. In this study, we report the outcome of our experience with fish oil monotherapy for IFALD in a fish oil-based combination lipid emulsion administered to preterm low birth weight infants. Fasting neonates were administered as PN according to our center's nutrition protocol. A diagnosis of IFALD was made when the serum direct bilirubin levels were >2.0 mg/dL in two consecutive measurements that were more than one week apart, without evidence of intrinsic causes of liver dysfunction. The management of IFALD was conducted by switching the lipid emulsion from combination lipid emulsion to fish oil monotherapy at 1.0 g/kg/day, infused over 24 h. Fifteen infants met the criteria for IFALD and received fish oil monotherapy. The median gestational age was 27.5 weeks and the median birth weight was 862.5 g. IFALD was successfully reversed in 11 infants (11/15, 73.3%). The median duration of fish oil monotherapy was 39 days. Direct bilirubin values were initially elevated and then steadily declined from the third week of treatment onward. The enteral tolerance increased in varying degrees during the treatment period. The mean weight gain was 26.0 g/day during fish oil monotherapy. Omegaven^® (Fresenius Kabi Austria Gmbh, Graz, Austria) at a dose of 1.0 g/kg/day was well tolerated, and no adverse events related to Omegaven use were seen. The reversal of IFALD in preterm infants on combination lipid emulsion containing fish oil was achieved by switching to fish oil monotherapy.

Effect of Nonintervention vs Oral Ibuprofen in Patent Ductus Arteriosus in Preterm Infants: A Randomized Clinical Trial

IMPORTANCE

Persistent patent ductus arteriosus (PDA) in preterm infants is associated with increased mortality and respiratory morbidities, including bronchopulmonary dysplasia (BPD). Despite recent increasing use of noninterventional approaches, no study to our knowledge has yet directly compared the nonintervention vs pharmacologic treatment for mediating PDA closure for decreasing mortality and preventing BPD.

OBJECTIVE

To determine the noninferiority of nonintervention vs oral ibuprofen treatment for PDA in decreasing BPD incidence or death in very preterm infants.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, placebo-controlled, noninferiority clinical trial was conducted on preterm infants (gestational age [GA] 23-30 weeks) with hemodynamically significant PDA (ductal size >1.5 mm plus respiratory support) diagnosed between postnatal days 6 and 14. Participants included 383 infants screened between July 24, 2014, and March 15, 2019.

INTERVENTIONS

Infants were stratified by GA and randomly assigned (1:1) to receive either oral ibuprofen (initial dose of 10 mg/kg followed by a 5-mg/kg dose after 24 hours and a second 5-mg/kg dose after 48 hours) or placebo.

MAIN OUTCOMES AND MEASURES

The primary outcome was BPD or death; the secondary outcomes included major morbidities and ductal closure rates. Per-protocol analysis was used.

RESULTS

Among 383 infants screened for participation, 146 infants were randomly assigned, with 72 in the nonintervention and 70 in the ibuprofen treatment group in the final analyses. The PDA closure rate at 1 week after randomization was significantly higher with ibuprofen (11 [34%]) than nonintervention (2 [7%]) in infants at GA 27 to 30 weeks (P = .007); however, the findings were not significant at GA 23 to 26 weeks (ibuprofen, 3 [8%] vs nonintervention, 1 [2%], P = .34). In addition, the ductal closure rates before hospital discharge (ibuprofen, 62 [89%] vs nonintervention, 59 [82%], P = .27) and device closure (ibuprofen, 2 [3%] vs nonintervention, 4 [6%], P = .40) were not significantly different between the 2 groups. The nonintervention approach was noninferior to ibuprofen treatment in terms of BPD incidence or death (nonintervention, 44%; ibuprofen, 50%; 95% CI, -0.11 to 0.22; noninferiority margin -0.2; P = .51). One infant in the ibuprofen arm received oral ibuprofen backup rescue treatment owing to cardiopulmonary compromise refractory to conservative management, and another infant in the ibuprofen group received surgical ligation; none of the infants in the placebo group received backup treatment.

CONCLUSIONS AND RELEVANCE

Nonintervention showed noninferiority compared with ibuprofen treatment in closing of hemodynamically significant PDA and reduction of BPD or death. The noninferiority of nonintervention over ibuprofen might be attributable to the low efficacy of oral ibuprofen for closing PDA, especially in infants born at 23 to 26 weeks' gestation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02128191.

Antenatal magnesium sulfate treatment and risk of necrotizing enterocolitis in preterm infants born at less than 32 weeks of gestation

Antenatal magnesium sulfate (MgSO4) treatment is widely used for fetal neuroprotection in women at risk of preterm delivery. However, some studies have recently suggested that in utero MgSO4 exposure is associated with an increased risk of necrotizing enterocolitis (NEC). This study aimed to investigate the association between antenatal MgSO4 treatment and risk of NEC. This retrospective cohort study included 756 infants born at 24‒31 weeks' gestation. Subjects were classified into three groups: period 1, when MgSO4 treatment protocol for fetal neuroprotection was not adopted (n = 267); period 2, when the protocol was adopted (n = 261); and period 3, when the protocol was withdrawn because of concern of risk of NEC (n = 228). Rates of NEC (≥ stage 2b) were analyzed according to time period and exposure to antenatal MgSO4. Significant difference in the rate of NEC was not found across the three time periods (2.6% vs. 6.5% vs. 4.8% in periods 1, 2 and 3, respectively, p = 0.103). The rate of NEC was comparable between the infants exposed and unexposed to antenatal MgSO4 (5.1% vs. 3.6%, p = 0.369). These results showed that antenatal MgSO4 treatment was not associated with risk of NEC in our study population.

Neonatal outcome comparisons between preterm infants with or without early pulmonary hypertension following prolonged preterm premature rupture of membranes before 25 gestational weeks in Korean Neonatal Network

Objective: To determine the outcomes of very low birth weight infants (VLBWIs) following maternal mid-trimester prolonged preterm premature rupture of membranes (PPROM) and subsequent early pulmonary hypertension (PH).Design: Prospective cohort study.Setting: A nationwide web-based registry of VLBWIs from 67 neonatal intensive care units.Patients: VLBWIs registered on the Korean Neonatal Network and born between 23 and 34 gestational weeks.Methods: VLBWIs exposed to maternal PPROM prior to 25 gestational weeks and lasting ≥7 days (PPROM25, n = 402) were matched 1:1 with infants not exposed or exposed within 24 h to PPROM (CON, n = 402), using propensity score matching. The PPROM25 group was subdivided into PPROM25 groups with or without early PH, defined as exposure to inhaled nitric oxide or other pulmonary vasodilators to treat PH within 3 days of life. Clinical variables and major outcomes were compared, and risk factors for mortality and morbidities were analyzed.Results: Of 1790 infants with maternal PPROM, the PPROM25 group comprised 402 (22.5%) infants. Survival rates were similar between the CON and PPROM25 groups (71.6% vs 74.4%); however, the incidence of bronchopulmonary dysplasia (BPD) differed (47.8% and 60.2%, p < .05). Infants in the PPROM25 group with early PH had higher mortality (55.6%) and more severe intraventricular hemorrhage (IVH) (31.7%) than infants in the PPROM25 group without early PH (21.9% and 14.3%, respectively; p < .05). In multivariate analysis, lower 5 min Apgar score and the presence of oligohydramnios increased the risk of development of early PH. The presence of PPROM25 was founded to be a significant risk factor for BPD and early PH in relation to mortality and severe IVH, respectively.Conclusions: In VLBWIs, prolonged exposure to maternal mid-trimester PPROM increased the risk of BPD. Subsequent early PH immediately after birth increased mortality and severe IVH, thus, requires special attention.

A Preterm Infant with Multiple Anomalies Diagnosed with Atypical CHARGE Syndrome after a Novel CHD7 Variant Confirmed Using Whole-Genome Sequencing

CHARGE syndrome has a clinically broad spectrum of phenotypes, including partial or atypical type. CHD7 mutation is related to CHARGE syndrome that shows various phenotypes according to the CHD7 variant. Developments in genetic analysis techniques, such as next-generation sequencing (NGS), are helping both diagnosis and treatment of diseases. We report the case of a preterm infant diagnosed with atypical CHARGE who has a novel and de novo CHD7 variant that was identified using whole-genome sequencing (WGS). Neonatologists tend to be reluctant to diagnose infants with multiple malformations because they have to focus on treating life-threatening complications; however, NGS is considered helpful for the early diagnosis of broad-spectrum anomalies during the neonatal period.

Conservative Non-intervention Approach for Hemodynamically Significant Patent Ductus Arteriosus in Extremely Preterm Infants

While persistent patent ductus arteriosus (PDA) in preterm infants has been known to be associated with increased mortality and morbidities including bronchopulmonary dysplasia, and necrotizing enterocolitis, there is minimal evidence supporting their causal relationships, and most traditional medical and/or surgical treatments have failed to show improvements in these outcomes. As such, the pendulum has swung toward the conservative non-intervention approach for the management of persistent PDA during the last decade; however, the benefits and risks of this approach are unclear. In this mini review, we focused on whom, when, and how to apply the conservative non-intervention approach for persistent PDA, especially in extremely preterm infants.

The Impact of Surgical Intervention on Neurodevelopmental Outcomes in Very Low Birth Weight Infants: a Nationwide Cohort Study in Korea

BACKGROUND

To investigate the incidence of surgical intervention in very low birth weight (VLBW) infants and the impact of surgery on neurodevelopmental outcomes at corrected ages (CAs) of 18-24 months, using data from the Korean Neonatal Network (KNN).

METHODS

Data from 7,885 VLBW infants who were born and registered with the KNN between 2013 to 2016 were analyzed in this study. The incidences of various surgical interventions and related morbidities were analyzed. Long-term neurodevelopmental outcomes at CAs of 18-24 months were compared between infants (born during 2013 to 2015, n = 3,777) with and without surgery.

RESULTS

A total of 1,509 out of 7,885 (19.1%) infants received surgical interventions during neonatal intensive care unit (NICU) hospitalization. Surgical ligation of patent ductus arteriosus (n = 840) was most frequently performed, followed by laser therapy for retinopathy of prematurity and laparotomy due to intestinal perforation. Infants who underwent surgery had higher mortality rates and greater neurodevelopmental impairment than infants who did not undergo surgery (P value < 0.01, both). On multivariate analysis, single or multiple surgeries increased the risk of neurodevelopmental impairment compared to no surgery with adjusted odds ratios (ORs) of 1.6 with 95% confidence interval (CI) of 1.1-2.6 and 2.3 with 95% CI of 1.1-4.9.

CONCLUSION

Approximately one fifth of VLBW infants underwent one or more surgical interventions during NICU hospitalization. The impact of surgical intervention on long-term neurodevelopmental outcomes was sustained over a follow-up of CA 18-24 months. Infants with multiple surgeries had an increased risk of neurodevelopmental impairment compared to infants with single surgeries or no surgeries after adjustment for possible confounders.

Initial and delayed thyroid-stimulating hormone elevation in extremely low-birth-weight infants

BACKGROUND

To determine the incidence, etiology, and outcomes of thyroid-stimulating hormone (TSH) elevation in extremely low-birth-weight infants (ELBWIs).

METHODS

Newborn thyroid screening data of 584 ELBWIs (birth weight, < 1000 g; gestational age, ≥ 23 weeks) were retrospectively analyzed to identify initial (≤ 2 postnatal weeks) and delayed (> 2 weeks) TSH elevations. Growth and neurodevelopmental outcomes at 2 years' corrected age (CA) were assessed according to levothyroxine replacement.

RESULTS

Initial and delayed TSH elevations were detected at CAs of 27 and 30 weeks, respectively, with incidence rates of 0.9 and 7.2%, respectively. All infants with initial TSH elevations had perinatal asphyxia, and 95% of those with delayed TSH elevation were exposed to various stressors, including respiratory support, drugs, and surgery within 2 weeks before diagnosis of TSH elevation. Free thyroxine (T4) levels were simultaneously reduced in 80 and 57% of infants with initial and delayed TSH elevations, respectively. Both initial and delayed TSH elevations were transient, regardless of levothyroxine replacement. Infants receiving levothyroxine replacement therapy had significantly higher TSH elevations, significantly lower free T4 levels, and significantly reduced mortality, compared to untreated infants. However, levothyroxine replacement had no significant effect on long-term growth and neurodevelopmental outcomes.

CONCLUSIONS

The timing of insult superimposition on hypothalamic-pituitary-thyroid axis maturation is a major determinant of initial or delayed TSH elevation in ELBWIs. Levothyroxine replacement did not affect growth or neurodevelopmental outcomes in this population.

Continuous Renal Replacement Therapy in Preterm Infants

PURPOSE

Despite the increasing use of continuous renal replacement therapy (CRRT) in the neonatal intensive care unit (NICU), few studies have investigated its use in preterm infants. This study evaluated the prognosis of preterm infants after CRRT and identified risk factors of mortality after CRRT.

MATERIALS AND METHODS

A retrospective review was performed in 33 preterm infants who underwent CRRT at the NICU of Samsung Medical Center between 2008 and 2017. Data of the demographic characteristics, predisposing morbidity, cardiopulmonary function, and CRRT were collected and compared between surviving and non-surviving preterm infants treated with CRRT. Univariable and multivariable analyses were performed to identify factors affecting mortality.

RESULTS

Compared with the survivors, the non-survivors showed younger gestational age (29.3 vs. 33.6 weeks), lower birth weight (1359 vs. 2174 g), and lower Apgar scores at 1 minute (4.4 vs. 6.6) and 5 minutes (6.5 vs. 8.6). At the initiation of CRRT, the non-survivors showed a higher incidence of inotropic use (93% vs. 40%, p=0.017) and fluid overload (16.8% vs. 4.0%, p=0.031). Multivariable analysis revealed that fluid overload >10% at CRRT initiation was the primary determinant of mortality after CRRT in premature infants, with an adjusted odds ratio of 14.6 and a 95% confidence interval of 1.10-211.29.

CONCLUSION

Our data suggest that the degree of immaturity, cardiopulmonary instability, and fluid overload affect the prognosis of preterm infants after CRRT. Preventing fluid overload and earlier initiation of CRRT may improve treatment outcomes.

Increased risk of refeeding syndrome-like hypophosphatemia with high initial amino acid intake in small-for-gestational-age, extremely-low-birthweight infants

BACKGROUND

Recent nutrition guidelines for extremely-low-birth-weight infants (ELBWIs) recommend implementation of high initial amino acid (AA) supplementation in parenteral nutrition.

OBJECTIVE

We sought to evaluate the influence of AA intake on refeeding syndrome-like electrolyte disturbances including hypophosphatemia in ELBWIs.

STUDY DESIGN

Medical records of 142 ELBWIs were reviewed. Demographic, nutritional, outcome, and electrolyte data were compared between ELBWIs with initial low (1.5 g/kg/day) and high (3 g/kg/day) AA intake. Multivariate analysis was conducted to determine the odds ratio of hypophosphatemia with high AA intake and small-for-gestational-age (SGA) ELBWIs.

RESULTS

The incidence of hypophosphatemia and severe hypophosphatemia increased from 51% and 8% in period I to 59% and 20% in period II, respectively (p = 0.36 and < 0.01). Specifically, SGA ELBWIs showed higher incidence of hypophosphatemia than appropriate-for-gestational age (AGA) ELBWIs in period II, whereas there was no difference in period I. For severe hypophosphatemia, SGA ELBWIs presented a 27% incidence versus a 2% incidence in AGA ELBWIs, even with low initial AA intake. Despite no difference in phosphate intake between infants with and without hypophosphatemia, serum phosphate level reached a nadir at the sixth postnatal day and gradually recovered over the second week in infants with hypophosphatemia. In multivariate analyses, the odds ratios for severe hypophosphatemia were 3.6 and 6.6 with high AA intake and SGA status, respectively, with the highest being 18.0 with combined high AA intake and SGA status.

CONCLUSIONS

In summary, high initial AA intake significantly increased the risk of refeeding syndrome-like electrolyte dysregulations including severe hypophosphatemia in ELBWIs. In SGA ELBWIs, the risk of electrolyte disturbance was significantly higher, even with low initial AA intake. Therefore, new tailored parenteral nutrition protocols starting with lower energy intake and a gradual increase over the first week may be warranted for application in high-risk SGA ELBWIs.

Thrombin Preconditioning Enhances Therapeutic Efficacy of Human Wharton's Jelly-Derived Mesenchymal Stem Cells in Severe Neonatal Hypoxic Ischemic Encephalopathy

We investigated whether thrombin preconditioning of human Wharton's jelly-derived mesenchymal stem cells (MSCs) improves paracrine potency and thus the therapeutic efficacy of naïve MSCs against severe hypoxic ischemic encephalopathy (HIE). Thrombin preconditioning significantly enhances the neuroprotective anti-oxidative, anti-apoptotic, and anti-cytotoxic effects of naïve MSCs against oxygen-glucose deprivation (OGD) of cortical neurons in vitro. Severe HIE was induced in vivo using unilateral carotid artery ligation and hypoxia for 2 h and confirmed using brain magnetic resonance imaging (MRI) involving >40% of ipsilateral hemisphere at postnatal day (P) 7 in newborn rats. Delayed intraventricular transplantation of 1 × 105 thrombin preconditioned but not naïve MSCs at 24 h after hypothermia significantly enhanced observed anti-inflammatory, anti-astroglial, and anti-apoptotic effects and the ensuing brain infarction; behavioral tests, such as cylinder rearing and negative geotaxis tests, were conducted at P42. In summary, thrombin preconditioning of human Wharton's jelly-derived MSCs significantly boosted the neuroprotective effects of naïve MSCs against OGD in vitro by enhancing their anti-oxidative, anti-apoptotic, and anti-cytotoxic effects, and significantly attenuated the severe HIE-induced brain infarction and improved behavioral function tests in vivo by maximizing their paracrine anti-inflammatory, anti-astroglial, and anti-apoptotic effects.

A Rare Case of Lethal Prenatal-Onset Infantile Cortical Hyperostosis

Infantile cortical hyperostosis, or Caffey's disease, usually presents with typical radiological features of soft tissue swelling and cortical thickening of the underlying bone. The disease can be fatal when it presents antenatally, especially before a gestational age of 35 weeks. This fatal, premature form of the disease is known to occur in various ethnic groups around the globe, and approximately 30 cases have been reported in English literature. This paper is unique in that it is the first paper to report a lethal form of prenatal-type infantile cortical hyperostosis diagnosed in South Korea. Born at gestational age of 27 weeks and 4 days, the patient had typical features of polyhydramnios, anasarca, hyperostosis of multiple bones, micrognathia, pulmonary hypoplasia, and hepatomegaly. The patient was hypotonic, and due to pulmonary hypoplasia and persistent pulmonary hypertension, had to be supported with high frequency ventilation throughout the entire hospital course. Due to the disease entity itself, as well as prolonged parenteral nutrition, liver failure progressed, and the patient expired on day 38 when uncontrolled septic shock was superimposed. The chromosome karyotype of the patient was normal, 46, XX, and COL1A1 gene mutation was not detected.

Thrombin Preconditioning of Extracellular Vesicles Derived from Mesenchymal Stem Cells Accelerates Cutaneous Wound Healing by Boosting Their Biogenesis and Enriching Cargo Content

The aim of this study was to determine the optimal preconditioning regimen for the wound healing therapeutic efficacy of mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs). To this end, we compared various preconditioning regimens for both the quantitative and qualitative production of MSC-derived EVs, and their therapeutic efficacy for proangiogenic activity in vitro and cutaneous wound healing in vivo. After preconditioning with thrombin (40 U), H₂O₂ (50 μM), lipopolysaccharide (1 μg/mL), or hypoxia (10% O₂), EV secretion was assessed quantitatively by measuring production per cell and protein quantification, and qualitatively by measuring a proteome profiler and an enzyme-linked immunosorbent assay (ELISA) contained within EVs. The therapeutic efficacy of EVs was assessed in vitro by proliferation, migration and tube formation assays of human umbilical cord blood endothelial cells (HUVECs), and in vivo by quantification of cutaneous wound healing. Thrombin preconditioning optimally boosted EV production and enriched various growth factors including vascular endothelial growth factor and angiogenin contained within EVs compared to other preconditioning regimens. Thrombin preconditioning optimally enhanced proliferation, the migration and tube formation of HUVECs in vitro via pERK1/2 and pAKT signaling pathways, and cutaneous wound healing in vivo compared to other preconditioning regimens. Thrombin preconditioning exhibited optimal therapeutic efficacy compared with other preconditioning regimens in promoting proangiogenic activity in vitro and in enhancing cutaneous wound healing in vivo. These preconditioning regimen-dependent variations in therapeutic efficacy might be mediated by boosting EV production and enriching their cargo content.

Natural evolution of ductus arteriosus with noninterventional conservative management in extremely preterm infants born at 23-28 weeks of gestation

This study aimed to determine the natural course of patent ductus arteriosus (PDA) with noninterventional conservative management and whether the presence and/or prolonged duration of hemodynamically significant (HS) PDA increased the risk of mortality and morbidities in extremely preterm (EPT) infants. We retrospectively reviewed the medical records of EPT infants born at 23-28 weeks of gestation (n = 195) from January 2011 to June 2014, when PDA was managed with noninterventional conservative treatment. We stratified infants into three subgroups of 23-24, 25-26, and 27-28 weeks and analyzed the prevalence and natural evolution of HS PDA, defined as ventilator dependency and PDA size ≥2 mm. Multivariate regression analyses determined if the presence and/or prolonged duration of HS PDA increased the risk for mortality and/or morbidities. The overall incidence of HS PDA was 57% (111/195) at the end of the first postnatal week. In subgroup analyses, infants with 23-24 weeks of gestation had the highest incidence (93%, 50/54), with 64% (47/74) for 25-26 weeks and 21% (14/67) for 27-28 weeks. Six (5%) of 111 infants with HS PDA were discharged without ductus closure, 4 had spontaneous PDA closure on follow up, and device closure was performed for 2 infants. In the multivariate analyses, the presence or prolonged duration (per week) of HS PDA was not associated with the risk of mortality and/or morbidities. Spontaneous closure of HS PDA was mostly achieved, even in EPT infants, with a noninterventional conservative approach. In conclusion, our data showed the incidence and natural course of HS PDA in EPT infants and suggested that the presence or prolonged duration of HS PDA might not increase the rate of mortality or morbidities.

Mesenchymal Stem Cells for Severe Intraventricular Hemorrhage in Preterm Infants: Phase I Dose-Escalation Clinical Trial

We previously demonstrated that transplanting mesenchymal stem cells (MSCs) improved recovery from brain injury induced by severe intraventricular hemorrhage (IVH) in newborn rats. To assess the safety and feasibility of MSCs in preterm infants with severe IVH, we performed a phase I dose-escalation clinical trial. The first three patients received a low dose of MSCs (5 × 106 cells/kg), and the next six received a high dose (1 × 107 cells/kg). We assessed adverse outcomes, including mortality and the progress of posthemorrhagic hydrocephalus. Intraventricular transplantation of MSCs was performed in nine premature infants with mean gestational age of 26.1 ± 0.7 weeks and birth weight of 808 ± 85 g at 11.6 ± 0.9 postnatal days. Treatment with MSCs was well tolerated, and no patients showed serious adverse effects or dose-limiting toxicities attributable to MSC transplantation. There was no mortality in IVH patients receiving MSCs. Infants who underwent shunt surgery showed a higher level of interleukin (IL)-6 in cerebrospinal fluid (CSF) obtained before MSC transplantation in comparison with infants who did not receive a shunt. Levels of IL-6 and tumor necrosis factor-α in initially obtained CSF correlated significantly with baseline ventricular index. Intraventricular transplantation of allogeneic human UCB-derived MSCs into preterm infants with severe IVH is safe and feasible, and warrants a larger, and controlled, phase II study. Stem Cells Translational Medicine 2018;7:847-856.

Human UCB-MSCs treatment upon intraventricular hemorrhage contributes to attenuate hippocampal neuron loss and circuit damage through BDNF-CREB signaling

Background

Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) have been shown to prevent brain damage and improve neurocognition following intraventricular hemorrhage (IVH). However, the molecular mechanisms underlying the effects of hUCB-MSCs are still elusive. Thus, as the hippocampus is essential for learning, memory, and cognitive functions and is intimately involved in the ventricular system, making it a potential site of IVH-induced injury, we determined the molecular basis of the effects of hUCB-derived MSCs on hippocampal neurogenesis and the recovery of hippocampal neural circuits after IVH in a rodent model.

Methods

We inflicted severe IVH injury on postnatal day 4 (P4) in rats. After confirmation of successful induction of IVH using MRI (P5), intracerebroventricular administration of MSCs (ICV-MSC) was performed at 2 days post-injury (P6). For hippocampal synaptic determination, a rat entorhinal-hippocampus (EH) organotypic slice co-culture (OSC) was performed using day 3 post-IVH brains (P7) with or without ICV-MSCs. A similar strategy of experiments was applied to those rats receiving hUCB-MSC transfected with BDNF-Si-RNA for knockdown of BDNF or scrambled siRNA controls after IVH. The molecular mechanism of the MSCs effects on neurogenesis and the attenuation of neuron death was determined by evaluation of BDNF-TrkB-Akt-CREB signaling axis.

Results

We showed that treatment with hUCB-MSCs attenuated neuronal loss and promoted neurogenesis in the hippocampus, an area highly vulnerable to IVH-induced brain injury. hUCB-MSCs activate BDNF-TrkB receptor signaling, eliciting intracellular activation of Akt and/or Erk and subsequent phosphorylation of CREB, which is responsible for promoting rat BDNF transcription. In addition to the beneficial effects of neuroprotection and neurogenesis, hUCB-MSCs also contribute to the restoration of impaired synaptic circuits in the hippocampus and improve neurocognitive functions in IVH-injured neonatal rat through BDNF-TrkB-CREB signaling axis activation.

Conclusions

Our data suggest that hUCB-MSCs possess therapeutic potential for treating neuronal loss and neurocognitive dysfunction in IVH through the activation of intracellular TrkB-CREB signaling that is invoked by hUCB-MSC-secreted BDNF.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-1052-5) contains supplementary material, which is available to authorized users.

Mesenchymal stem cells transplantation attenuates brain injury and enhances bacterial clearance in Escherichia coli meningitis in newborn rats

OBJECTIVE

Neonatal meningitis caused by Escherichia coli results in significant mortality and neurological disabilities, with few effective treatments. Recently, we demonstrated that human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) transplantation attenuated E. coli-induced severe pneumonia, primarily by reducing inflammation and enhancing bacterial clearance. This study aimed to determine whether intraventricular transplantation of hUCB-MSCs attenuated the brain injury in E. coli meningitis in newborn rats.

METHODS

Meningitis without concomitant bacteremia was induced by intraventricular injection of 5 × 10² colony forming units of K1 (-) E. coli in rats at postnatal day (P)11, and hUCB-MSCs (1 × 10⁵) were transplanted intraventricularly 6 h after induction of meningitis. Antibiotics was started 24 h after modeling.

RESULT

Meningitis modeling induced robust proliferation of E. coli in the cerebrospinal fluid and increased mortality in rat pups, and MSC transplantation significantly reduced this bacterial growth and the mortality rate. Impaired sensorimotor function in the meningitis rats was ameliorated by MSCs injection. MSCs transplantation also attenuated meningitis caused brain injury including cerebral ventricular dilatation, brain cell death, reactive gliosis, and inflammatory response.

CONCLUSION

Intraventricular transplantation of hUCB-MSCs significantly improved survival and attenuated the brain injury via anti-inflammatory and antibacterial effects in experimental neonatal E. coli meningitis.

Hypothermia broadens the therapeutic time window of mesenchymal stem cell transplantation for severe neonatal hypoxic ischemic encephalopathy

Recently, we have demonstrated that concurrent hypothermia and mesenchymal stem cells (MSCs) transplantation synergistically improved severe neonatal hypoxic ischemic encephalopathy (HIE). The current study was designed to determine whether hypothermia could extend the therapeutic time window of MSC transplantation for severe neonatal HIE. To induce HIE, newborn rat pups were exposed to 8% oxygen for 2 h following unilateral carotid artery ligation on postnatal day (P) 7. After approving severe HIE involving >50% of the ipsilateral hemisphere volume, hypothermia (32 °C) for 2 days was started. MSCs were transplanted 2 days after HIE modeling. Follow-up brain MRI, sensorimotor function tests, assessment of inflammatory cytokines in the cerebrospinal fluid (CSF), and histological evaluation of peri-infarction area were performed. HIE induced progressively increasing brain infarction area over time, increased cell death, reactive gliosis and brain inflammation, and impaired sensorimotor function. All these damages observed in severe HIE showed better, robust improvement with a combination treatment of hypothermia and delayed MSC transplantation than with either stand-alone therapy. Hypothermia itself did not significantly reduce brain injury, but broadened the therapeutic time window of MSC transplantation for severe newborn HIE.

Predicting mortality in extremely low birth weight infants: Comparison between gestational age, birth weight, Apgar score, CRIB II score, initial and lowest serum albumin levels

We explored GA, BW, Apgar score, CRIB II score, and serum albumin levels as univariate predictors of mortality in extremely low birth weight infants. Medical records of 564 extremely low birth weight infants were reviewed retrospectively. The infants were grouped as survivors (group I), expired ≤ 7^th postnatal day (group II), and expired > 7^th postnatal day (group III). The predictive value for mortality of gestational age, birth weight, Apgar scores at 1 and 5 min, clinical risk index for babies II score, and first and lowest serum albumin levels was assessed by calculating the associated area under the curve (AUC) in receiver operating characteristic (ROC) curves. The overall survival and mortality rates of groups I, II, and III were 81.0% (457/564), 7.6% (43/564), and 11.4% (64/564), respectively. Birth weight, Apgar scores at 1 and 5 min, and first serum albumin levels were significantly higher, while the clinical risk index for babies II score was significantly lower in group I when compared to groups II and III. Gestational age and lowest serum albumin level in group I were significantly higher than group III, but not group II. However, gestational age, birth weight, and clinical risk index for babies II score showed gestational age dependent variations regardless of survival or mortality. Apgar score at 5 min (0.756) and lowest serum albumin level (0.771) demonstrated the highest AUC of the ROC curve in predicting mortality in group II and III, respectively. In conclusion, Apgar score at 5 min and lowest serum albumin level were the most effective predictors for mortality in extremely low birth weight infants during ≤ 7^th and > 7^th postnatal days, respectively.

The Youngest Survivor with Gestational Age of 21⁵/₇ Weeks

The decision whether or not to resuscitate extremely low gestational age (GA) infants is recommended to be individualized according to antenatal counseling with parents, neonatologists, and obstetricians. A GA of 22⁰/₇-23⁶/₇ weeks is generally considered as the lower end of the range where infants can be candidates for selective resuscitation. Below this lower end of periviable gestation, resuscitation is usually not considered and survivors are rarely reported. To date, the youngest survivor is an infant with a GA of 21⁶/₇ weeks reported in the English medical literature. Here, we report the case of a female infant, the first twin conceived through in vitro fertilization, with a GA of 21⁵/₇ weeks, who was resuscitated initially according to strong parental wishes after antenatal counseling and is still surviving at 43 months of age with fairly good neurodevelopmental outcome.

MERS-CoV Infection in a Pregnant Woman in Korea

Middle East respiratory syndrome (MERS) is a lethal respiratory disease - caused by MERS-coronavirus (MERS-CoV) which was first identified in 2012. Especially, pregnant women can be expected as highly vulnerable candidates for this viral infection. In May 2015, this virus was spread in Korea and a pregnant woman was confirmed with positive result of MERS-CoV polymerase chain reaction (PCR). Her condition was improved only with conservative treatment. After a full recovery of MERS, the patient manifested abrupt vaginal bleeding with rupture of membrane. Under an impression of placenta abruption, an emergent cesarean section was performed. Our team performed many laboratory tests related to MERS-CoV and all results were negative. We report the first case of MERS-CoV infection during pregnancy occurred outside of the Middle East. Also, this case showed relatively benign maternal course which resulted in full recovery with subsequent healthy full-term delivery without MERS-CoV transmission.

Prophylactic versus Early Rescue Surfactant Treatment in Preterm Infants Born at Less than 30 Weeks Gestation or with Birth Weight Less than or Equal 1,250 Grams

Prophylactic surfactant is known to be effective to reduce chronic lung disease in preterm infants compared with rescue surfactant treatment. In Korea, early prophylactic surfactant therapy was introduced in 2011. However, recently, the increased utilization of antenatal steroids and early stabilization through continuous positive airway pressure (CPAP) in the delivery room may have changed the risks and benefits of prophylactic surfactant therapy of infants at high risk of respiratory distress syndrome (RDS). We compared the effects and safety of prophylactic surfactant therapy (within 30 minutes after birth) and early selective surfactant therapy (within 3 hours after birth) in preterm infants born at < 30 weeks gestation or with birth weight ≤ 1,250 g. The clinical data of 193 infants in period 1 (from 2008 to 2010, early selective surfactant therapy group) were collected retrospectively; those of 191 infants in period 2 (from 2012 to 2014, prophylactic surfactant therapy group) were collected prospectively. Compared to period 1, the rate of intubation and surfactant use were significantly increased in period 2. The use of multiple doses of surfactant in period 2 was significantly increased compared with period 1. Despite more invasive and aggressive management in period 2, there was no difference in the duration of mechanical ventilation, the incidence of bronchopulmonary dysplasia (BPD) or death, and the risk of other adverse neonatal outcomes between the 2 groups. In conclusion, the benefit of prophylactic surfactant therapy in infants treated under current practices is no longer clear compared to early selective surfactant therapy.

Two-Year Follow-Up Outcomes of Premature Infants Enrolled in the Phase I Trial of Mesenchymal Stem Cells Transplantation for Bronchopulmonary Dysplasia

OBJECTIVE

To determine the long-term safety and outcomes of mesenchymal stem cells (MSCs) for bronchopulmonary dysplasia in premature infants enrolled in a previous phase I clinical trial up to 2 years of corrected age (CA).

STUDY DESIGN

We assessed serious adverse events, somatic growth, and respiratory and neurodevelopmental outcomes at visit 1 (4-6 months of CA), visit 2 (8-12 months of CA), and visit 3 (18-24 months of CA) in a prospective longitudinal follow-up study up to 2 years' CA of infants who received MSCs (MSC group). We compared these data with those from a historical case-matched comparison group.

RESULTS

One of 9 infants in the MSC group died of Enterobacter cloacae sepsis at 6 months of CA, the remaining 8 infants survived without any transplantation-related adverse outcomes, including tumorigenicity. No infant in the MSC group was discharged with home supplemental oxygen compared with 22% in the comparison group. The average rehospitalization rate in the MSC group was 1.4/patient because of respiratory infections during 2 years of follow-up. The mean body weight of the MSC group at visit 3 was significantly higher compared with that of the comparison group. No infant in the MSC group was diagnosed with cerebral palsy, blindness, or developmental delay; in the comparison group, 1 infant was diagnosed with cerebral palsy and 1 with developmental delay.

CONCLUSIONS

Intratracheal transplantation of MSCs in preterm infants appears to be safe, with no adverse respiratory, growth, and neurodevelopmental effects at 2 years' CA.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01632475.