Cognitive outcomes of preterm infants randomized to darbepoetin, erythropoietin, or placebo

Early High-Dose Erythropoietin and Cognitive Functions of School-Aged Children Born Very Preterm

Importance

Children born very preterm are at risk for long-term neurodevelopmental sequelae. Prophylactic high-dose recombinant human erythropoietin (rhEpo) shortly after birth has not been shown to improve cognitive, motor, and behavioral development at 2 and 5 years.

Objective

To investigate whether early high-dose rhEpo is associated with better executive functions and processing speed-late-maturing cognitive functions-in school-aged children born very preterm.

Design, Setting, and Participants

This single-center cohort study was a prospective, observational follow-up study of a multicenter neonatal clinical trial; 365 children born very preterm (mean gestational age, 29.3 weeks [range, 26.0-31.9 weeks]) who had been enrolled in the Swiss EPO Neuroprotection Trial at birth between 2005 and 2012, and who were included in the primary outcome analyses at 2 years, were eligible to be recruited for the EpoKids study between 2017 and 2021 when they were at school age. Term-born children were additionally recruited and included in a control group. Data were analyzed between May and September 2022.

Exposure

Administration of rhEpo (3000 IU/kg) or placebo (saline, 0.9%) intravenously 3 times within the first 2 days of life as part of the Swiss EPO Neuroprotection Trial.

Main Outcome and Measures

A comprehensive neuropsychological test battery assessed executive functions and processing speed, and parents reported on their child's executive functions in everyday life to test the hypothesis that early high-dose rhEpo administration is associated with better cognitive outcomes at school age.

Results

In the EpoKids study, 214 children born very preterm (58.6% of 365 children in eligible cohort) were assessed at a mean age of 10.4 years (range, 6.9-13.4 years); 117 (54.7%) were boys. There was no evidence that the 117 children who had received rhEpo differed from the 97 children who had received placebo in any of the 15 executive function and processing speed tests, nor in parent-rated executive functions (estimates ranged from -0.138 to 0.084, all 95% CIs included 0). Irrespective of rhEpo or placebo allocation, children born very preterm scored lower on 11 of 15 executive function and processing speed tests than term-born peers (estimates ranged from 0.112 to 0.255, 95% CIs did not include 0).

Conclusion and Relevance

This study found no evidence for a positive association between prophylactic early high-dose rhEpo administration and long-term neurodevelopmental outcomes after very preterm birth. These results suggest that a comprehensive approach, including pharmacological and nonpharmacological prevention and intervention strategies, is needed to support these children's neurodevelopmental outcome.

Pipeline to Neonatal Clinical Transformation: The Importance of Preclinical Data

Historically, neonatal neuroscience boasted a robust and successful preclinical pipeline for therapeutic interventions, in particular for the treatment of hypoxic-ischemic encephalopathy (HIE). However, since the successful translation of therapeutic hypothermia (TH), several high-profile failures of promising adjunctive therapies, in addition to the lack of benefit of TH in lower resource settings, have brought to light critical issues in that same pipeline. Using recent data from clinical trials of erythropoietin as an example, the authors highlight several key challenges facing preclinical neonatal neuroscience for HIE therapeutic development and propose key areas where model development and collaboration across the field in general can ensure ongoing success in treatment development for HIE worldwide.

Neuroprotective therapies in the NICU in preterm infants: present and future (Neonatal Neurocritical Care Series)

The survival of preterm infants has steadily improved thanks to advances in perinatal and neonatal intensive clinical care. The focus is now on finding ways to improve morbidities, especially neurological outcomes. Although antenatal steroids and magnesium for preterm infants have become routine therapies, studies have mainly demonstrated short-term benefits for antenatal steroid therapy but limited evidence for impact on long-term neurodevelopmental outcomes. Further advances in neuroprotective and neurorestorative therapies, improved neuromonitoring modalities to optimize recruitment in trials, and improved biomarkers to assess the response to treatment are essential. Among the most promising agents, multipotential stem cells, immunomodulation, and anti-inflammatory therapies can improve neural outcomes in preclinical studies and are the subject of considerable ongoing research. In the meantime, bundles of care protecting and nurturing the brain in the neonatal intensive care unit and beyond should be widely implemented in an effort to limit injury and promote neuroplasticity. IMPACT: With improved survival of preterm infants due to improved antenatal and neonatal care, our focus must now be to improve long-term neurological and neurodevelopmental outcomes. This review details the multifactorial pathogenesis of preterm brain injury and neuroprotective strategies in use at present, including antenatal care, seizure management and non-pharmacological NICU care. We discuss treatment strategies that are being evaluated as potential interventions to improve the neurodevelopmental outcomes of infants born prematurely.

Darbepoetin alfa to reduce transfusion episodes in infants with haemolytic disease of the fetus and newborn who are treated with intrauterine transfusions in the Netherlands: an open-label, single-centre, phase 2, randomised, controlled trial

BACKGROUND

Up to 88% of infants with haemolytic disease of the fetus and newborn who are treated with intrauterine transfusions require erythrocyte transfusions after birth. We aimed to investigate the effect of darbepoetin alfa on the prevention of postnatal anaemia in infants with haemolytic disease of the fetus and newborn.

METHODS

We conducted an open-label, single-centre, phase 2 randomised controlled trial to evaluate the effect of darbepoetin alfa on the number of erythrocyte transfusions in infants with haemolytic disease of the fetus and newborn. All infants who were treated with intrauterine transfusion and born at 35 weeks of gestation or later at the Leiden University Medical Center, Leiden, Netherlands, were eligible for inclusion. Included infants were randomised by computer at birth to treatment with 10 μg/kg darbepoetin alfa subcutaneously once a week for 8 weeks or standard care (1:1 allocation, in varying blocks of four and six, with no stratification). Treating physicians and parents were not masked to treatment allocation, but the research team, data manager, and statistician were masked to treatment allocation during the process of data collection. The primary outcome was the number of erythrocyte transfusion episodes per infant from birth up to 3 months of life in the modified intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT03104426) and has been completed.

FINDINGS

Between Oct 31, 2017, and April 31, 2022, we recruited 76 infants, of whom 44 (58%) were randomly assigned to a treatment group (20 [45%] were allocated to receive darbepoetin alfa and 24 [55%] were allocated to receive standard care). Follow-up lasted 3 months and one infant dropped out of the trial before commencement of treatment. A significant reduction in erythrocyte transfusion episodes was identified with darbepoetin alfa treatment compared with standard care (median 1·0 [IQR 1·0-2·0] transfusion episodes vs 2·0 [1·3-3·0] transfusion episodes; p=0·0082). No adverse events were reported and no infants died during the study.

INTERPRETATION

Darbepoetin alfa reduced the transfusion episodes after intrauterine transfusion treatment for haemolytic disease of the fetus and newborn. Treatment with darbepoetin alfa or other types of erythropoietin should be considered as part of the postnatal treatment of severe haemolytic disease of the fetus and newborn.

FUNDING

Sanquin Blood Supply.

TRANSLATION

For the Dutch translation of the abstract see Supplementary Materials section.

Anemia, Iron Supplementation, and the Brain

The developing brain is particularly vulnerable to extrinsic environmental events such as anemia and iron deficiency during periods of rapid development. Studies of infants with postnatal iron deficiency and iron deficiency anemia clearly demonstrated negative effects on short-term and long-term brain development and function. Randomized interventional trials studied erythropoiesis-stimulating agents and hemoglobin-based red blood cell transfusion thresholds to determine how they affect preterm infant neurodevelopment. Studies of red blood cell transfusion components are limited in preterm neonates. A biomarker strategy measuring brain iron status and health in the preanemic period is desirable to evaluate treatment options and brain response.

Pathophysiology of Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a complex disease involving development of the neural retina, ocular circulations, and other organ systems of the premature infant. The external stresses of the ex utero environment also influence the pathophysiology of ROP through interactions among retinal neural, vascular, and glial cells. There is variability among individual infants and presentations of the disease throughout the world, making ROP challenging to study. The methods used include representative animal models, cell culture, and clinical studies. This article describes the impact of maternal-fetal interactions; stresses that the preterm infant experiences; and biologic pathways of interest, including growth factor effects and cell-cell interactions, on the complex pathophysiology of ROP phenotypes in developed and emerging countries.

Chorioamnionitis disrupts erythropoietin and melatonin homeostasis through the placental-fetal-brain axis during critical developmental periods

Introduction: Novel therapeutics are emerging to mitigate damage from perinatal brain injury (PBI). Few newborns with PBI suffer from a singular etiology. Most experience cumulative insults from prenatal inflammation, genetic and epigenetic vulnerability, toxins (opioids, other drug exposures, environmental exposure), hypoxia-ischemia, and postnatal stressors such as sepsis and seizures. Accordingly, tailoring of emerging therapeutic regimens with endogenous repair or neuro-immunomodulatory agents for individuals requires a more precise understanding of ligand, receptor-, and non-receptor-mediated regulation of essential developmental hormones. Given the recent clinical focus on neurorepair for PBI, we hypothesized that there would be injury-induced changes in erythropoietin (EPO), erythropoietin receptor (EPOR), melatonin receptor (MLTR), NAD-dependent deacetylase sirtuin-1 (SIRT1) signaling, and hypoxia inducible factors (HIF1α, HIF2α). Specifically, we predicted that EPO, EPOR, MLTR1, SIRT1, HIF1α and HIF2α alterations after chorioamnionitis (CHORIO) would reflect relative changes observed in human preterm infants. Similarly, we expected unique developmental regulation after injury that would reveal potential clues to mechanisms and timing of inflammatory and oxidative injury after CHORIO that could inform future therapeutic development to treat PBI. Methods: To induce CHORIO, a laparotomy was performed on embryonic day 18 (E18) in rats with transient uterine artery occlusion plus intra-amniotic injection of lipopolysaccharide (LPS). Placentae and fetal brains were collected at 24 h. Brains were also collected on postnatal day 2 (P2), P7, and P21. EPO, EPOR, MLTR1, SIRT1, HIF1α and HIF2α levels were quantified using a clinical electrochemiluminescent biomarker platform, qPCR, and/or RNAscope. MLT levels were quantified with liquid chromatography mass spectrometry. Results: Examination of EPO, EPOR, and MLTR1 at 24 h showed that while placental levels of EPO and MLTR1 mRNA were decreased acutely after CHORIO, cerebral levels of EPO, EPOR and MLTR1 mRNA were increased compared to control. Notably, CHORIO brains at P2 were SIRT1 mRNA deficient with increased HIF1α and HIF2α despite normalized levels of EPO, EPOR and MLTR1, and in the presence of elevated serum EPO levels. Uniquely, brain levels of EPO, EPOR and MLTR1 shifted at P7 and P21, with prominent CHORIO-induced changes in mRNA expression. Reductions at P21 were concomitant with increased serum EPO levels in CHORIO rats compared to controls and variable MLT levels. Discussion: These data reveal that commensurate with robust inflammation through the maternal placental-fetal axis, CHORIO impacts EPO, MLT, SIRT1, and HIF signal transduction defined by dynamic changes in EPO, EPOR, MLTR1, SIRT1, HIF1α and HIF2α mRNA, and EPO protein. Notably, ligand-receptor mismatch, tissue compartment differential regulation, and non-receptor-mediated signaling highlight the importance, complexity and nuance of neural and immune cell development and provide essential clues to mechanisms of injury in PBI. As the placenta, immune cells, and neural cells share many common, developmentally regulated signal transduction pathways, further studies are needed to clarify the perinatal dynamics of EPO and MLT signaling and to capitalize on therapies that target endogenous neurorepair mechanisms.

Effect of Early High-Dose Recombinant Human Erythropoietin on Behavior and Quality of Life in Children Aged 5 Years Born Very Preterm: Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

In light of the promising neuroprotective properties of recombinant human erythropoietin (RHEpo), the Swiss EPO Neuroprotection Trial was started to investigate its effect on neurodevelopment in very preterm infants. The results of the primary and secondary outcome analysis did not show any effect of RHEpo on cognitive performance, neuromotor outcomes, or somatic growth of the study participants at ages 2 or 5 years.

OBJECTIVE

To investigate whether early high-dose RHEpo improves behavioral outcomes and health-related quality of life (HRQoL) at age 5 years.

DESIGN, SETTING, AND PARTICIPANTS

This was a prespecified secondary analysis of the double-blind, placebo-controlled, multicenter Swiss EPO Neuroprotection randomized clinical trial, which was conducted at 5 level-III perinatal centers in Switzerland. Infants born between 26 weeks 0 days' and 31 weeks 6 days' gestation were recruited between 2005 and 2012 and followed-up until age 5 years (last follow-up in 2018). Data were analyzed from January 6 to December 31, 2021.

INTERVENTIONS

Infants were assigned to receive either RHEpo (3000 IU/kg) or placebo (saline, 0.9%) intravenously 3 times within the first 42 hours after birth.

MAIN OUTCOMES AND MEASURES

The prespecified parent-reported measures of behavioral outcomes and health-related quality of life (HRQoL) of their children at the age of 5 years were assessed by two standardized questionnaires: the Strengths and Difficulties Questionnaire (behavioral outcomes) and the KIDSCREEN-27 (HRQoL).

RESULTS

Among 448 randomized infants, 228 infants were assigned to the RHEpo group and 220 infants were assigned to the placebo group. Questionnaire data were available for 317 children (71%) at a mean (SD) age of 5.8 (0.4) years (mean [SD] gestational age at birth, 29.3 [1.6] weeks; mean [SD] birth weight 1220 [340] grams; 128 [40%] female infants). At the age 5 years follow-up, the mean (SD) total difficulties score in the RHEpo group (8.41 [5.60] points) was similar to that of the placebo group (7.76 [4.81]) (P = .37). There were no statistically significant differences between the groups in any other outcome measures.

CONCLUSIONS AND RELEVANCE

This secondary analysis of a randomized clinical trial showed no evidence for an effect of early high-dose RHEpo administration on behavioral outcomes or HRQoL in children born very preterm at early school age.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00413946.

Neonatal administration of erythropoietin attenuates cognitive deficits in adult rats following placental insufficiency

Preterm birth is a principal cause of neurological disability later in life, including cognitive and behavioral deficits. Notably, cognitive impairment has greater impact on quality of life than physical disability. Survivors of preterm birth commonly have deficits of executive function. Difficulties with tasks and planning complexity correlate positively with increasing disability. To overcome these barriers for children born preterm, preclinical and clinical studies have emphasized the importance of neurorestoration. Erythropoietin (EPO) is a endogenous cytokine with multiple beneficial mechanisms of action following perinatal brain injury. While most preclinical investigations have focused on pathology and molecular mechanisms, translational studies of repair using clinically viable biobehavioral biomarkers are still lacking. Here, using an established model of encephalopathy of prematurity secondary to placental insufficiency, we tested the hypothesis that administration of EPO in the neonatal period would attenuate deficits in recognition memory and cognitive flexibility in adult rats of both sexes. We assessed cognition and executive function in two ways. First, using the classic test of novel object recognition and second, using a touchscreen platform. Touchscreen testing allows for rigorous testing of cognition and executive function in preclinical and clinical scenarios. Data show that adult rats exhibit deficits in recognition memory and cognitive flexibility following in utero placental insufficiency. Notably, neonatal treatment of EPO attenuates these deficits in adulthood and facilitates functional repair. Together, these data validate EPO neurorestoration using a clinically relevant outcome measure and support the concept that postnatal treatment following in utero injury can improve cognition and executive function through adulthood.

Neonatal subgaleal hemorrhage: twenty years of trends in incidence, associations, and outcomes

BACKGROUND

In 2011, we reported 38 neonates with subgaleal hemorrhage (SH), relating an increasing incidence. It is unclear whether the incidence in our hospitals continued to rise and which risk factors and outcomes are associated with this condition.

DESIGN

We retrospectively analyzed every recognized case of SH in our hospitals from the end of our previous report (2010) to the present (2022). We redescribed the incidence, scored severity, tabulated blood products transfused, and recorded outcomes.

RESULTS

Across 141 months, 191 neonates were diagnosed with SH; 30 after vacuum or forceps. The incidence (one/1815 births) was higher than in our 2011 report (one/7124 births). Also, severe SH (requiring transfusion) was more common (one/10,033 births vs. one/20,950 births previously). Four died (all with severe SH) and 12 had neurodevelopmental impairment.

CONCLUSION

Recognized cases of SH are increasing in our system without a clear explanation. Adverse outcomes are rare but continue to occur.

Object Permanence and the Relationship to Sitting Development in Infants With Motor Delays

PURPOSE

This study examines object permanence development in infants with motor delays (MD) compared with infants with typical development (TD) and in relation to sitting skill.

METHODS

Fifty-six infants with MD (mean age = 10 months) and 36 with TD (mean age = 5.7 months) were assessed at baseline and then at 1.5, 3, and 6 months postbaseline. A scale was developed to measure object permanence (Object Permanence Scale [OPS]), and the Gross Motor Function Measure sitting subsection (GMFM-SS), and the Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley-III) were administered.

RESULTS

Interrater reliability of the OPS was excellent and correlation between the OPS and Bayley-III cognitive scores was moderately positive. Compared with TD, infants with MD were delayed in development of object permanence but demonstrated increased understanding over time and as sitting skills improved.

CONCLUSION

In children with MD, object permanence, as quantified by the OPS, emerges in conjunction with sitting skill.

The Effects of Nicotinamide Adenine Dinucleotide Phosphate (NADPH) Oxidase and Erythropoietin, and Their Interactions in Angiogenesis: Implications in Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a leading cause of vision impairment and blindness in premature infants. Oxidative stress is implicated in its pathophysiology. NADPH oxidase (NOX), a major enzyme responsible for reactive oxygen species (ROS) generation in endothelial cells, has been studied for its involvement in physiologic and pathologic angiogenesis. Erythropoietin (EPO) has gained interest recently due to its tissue protective and angiogenic effects, and it has been shown to act as an antioxidant. In this review, we summarize studies performed over the last five years regarding the role of various NOXs in physiologic and pathologic angiogenesis. We also discuss the effect of EPO in tissue and vasoprotection, and the intersection of EPO and NOX-mediated oxidative stress in angiogenesis and the pathophysiology of ROP.

Pharmacological Neuroprotection of the Preterm Brain: Current Evidence and Perspectives

Despite improvements in viability, the long-term neurodevelopmental outcomes of preterm babies remain serious concern as a significant percentage of these infants develop neurological and/or intellectual impairment, and they are also at increased risk of psychiatric illnesses later in life. The current challenge is to develop neuroprotective approaches to improve adverse outcomes in preterm survivors. The purpose of this review was to provide an overview of the current evidence on pharmacological agents targeting the neuroprotection of the preterm brain. Among them, magnesium sulfate, given antenatally to pregnant women with imminent preterm birth before 30 to 34 weeks of gestation, as well as caffeine administered to preterm infants after birth, exhibited neuroprotective effects for human preterm brain. Erythropoietin treatment of preterm infants did not result in neuroprotection at 2 years of age in two out of three published large randomized controlled trials; however, long-term follow-up of these infants is needed to come to definite conclusions. Further studies are also required to assess whether melatonin, neurosteroids, inhaled nitric oxide, allopurinol, or dietary supplements (omega-3 fatty acids, choline, curcumin, etc.) could be implemented as neuroprotectants in clinical practice. Furthermore, other pharmacological agents showing promising signs of neuroprotective efficacy in preclinical studies (growth factors, hyaluronidase inhibitors or treatment, antidiabetic drugs, cannabidiol, histamine-H3 receptor antagonists, etc.), as well as stem cell- or exosomal-based therapies and nanomedicine, may prove useful in the future as potential neuroprotective approaches for human preterm brain. KEY POINTS: · Magnesium and caffeine have neuroprotective effects for the preterm brain.. · Follow-up of infants treated with erythropoietin is needed.. · Neuroprotective efficacy of several drugs in animals needs to be shown in humans..

Erythropoietin as a Neuroprotective Drug for Newborn Infants: Ten Years after the First Use

Protective strategies against perinatal brain injury represent a major challenge for modern neonatology. Erythropoietin (Epo) enhances endogenous mechanisms of repair and angiogenesis. In order to analyse the newest evidence on the role of Epo in prematurity, hypoxic ischemic encephalopathy (HIE) and perinatal stroke, a critical review using 2020 PRISMA statement guidelines was conducted. This review uncovered 26 clinical trials examining the use of Epo for prematurity and brain injury-related outcomes. The effects of Epo on prematurity were analysed in 16 clinical trials. Erythropoietin was provided until 32–35 weeks of corrected postnatal age with a dosage between 500–3000 UI/kg/dose. Eight trials reported the Epo effects on HIE term newborn infants: Erythropoietin was administered in the first weeks of life, at different multiple doses between 250–2500 UI/kg/dose, as either an adjuvant therapy with hypothermia or a substitute for hypothermia. Two trials investigated Epo effects in perinatal stroke. Erythropoietin was administered at a dose of 1000 IU/kg for three days. No beneficial effect in improving morbidity was observed after Epo administration in perinatal stroke. A positive effect on neurodevelopmental outcome seems to occur when Epo is used as an adjuvant therapy with hypothermia in the HIE newborns. Administration of Epo in preterm infants still presents inconsistencies with regard to neurodevelopmental outcome. Clinical trials show significant differences mainly in target population and intervention scheme. The identification of specific markers and their temporal expression at different time of recovery after hypoxia-ischemia in neonates might be implemented to optimize the therapeutic scheme after hypoxic-ischemic injury in the developing brain. Additional studies on tailored regimes, accounting for the risk stratification of brain damage in newborns, are required.

Free Radicals and Neonatal Brain Injury: From Underlying Pathophysiology to Antioxidant Treatment Perspectives

Free radicals play a role of paramount importance in the development of neonatal brain injury. Depending on the pathophysiological mechanisms underlying free radical overproduction and upon specific neonatal characteristics, such as the GA-dependent maturation of antioxidant defenses and of cerebrovascular autoregulation, different profiles of injury have been identified. The growing evidence on the detrimental effects of free radicals on the brain tissue has led to discover not only potential biomarkers for oxidative damage, but also possible neuroprotective therapeutic approaches targeting oxidative stress. While a more extensive validation of free radical biomarkers is required before considering their use in routine neonatal practice, two important treatments endowed with antioxidant properties, such as therapeutic hypothermia and magnesium sulfate, have become part of the standard of care to reduce the risk of neonatal brain injury, and other promising therapeutic strategies are being tested in clinical trials. The implementation of currently available evidence is crucial to optimize neonatal neuroprotection and to develop individualized diagnostic and therapeutic approaches addressing oxidative brain injury, with the final aim of improving the neurological outcome of this population.

Effect of blood transfusions on cognitive development in very low birth weight infants

OBJECTIVE

Preterm infants frequently receive red cell transfusions; however, the effect of transfusions on cognition is unclear. We evaluated the relationship between transfusions and cognitive outcomes in preterm infants enrolled in a randomized trial of erythropoiesis stimulating agents (ESAs).

STUDY DESIGN

Preterm infants were randomized to ESAs or placebo during initial hospitalization, and transfusions recorded. Children were evaluated using standard developmental tests of cognition at 18-22 months (56 ESA, 24 placebo) and 3.5-4 years (39 ESA, 14 placebo).

RESULTS

Cognitive scores at 18-22 months were inversely correlated with transfusion volume (p = 0.02). Among those receiving ≥1 transfusion, cognitive scores were significantly higher in the ESA-treated group (p = 0.003). At 3.5-4 years, transfusions were not correlated with cognitive scores.

CONCLUSIONS

In the placebo group, transfused children had lower cognitive scores than did non-transfused children at 18-22 months. In the ESA group, cognitive scores did not differ by transfusion status, suggesting ESAs might provide neuroprotection.

Efficacy and safety of high and low dose recombinant human erythropoietin on neurodevelopment of premature infants: A meta-analysis

BACKGROUND

To evaluate the effect of recombinant human erythropoietin (rhEPO) in nervous system of premature infants including different dosage.

METHODS

The multiple databases like Pubmed, Embase, Cochrane databases and China National Knowledge Database were used to search for the relevant studies, and full-text articles involved in the evaluation on effect of rhEPO for neurodevelopment among premature infants. Review Manager 5.2 was adopted to estimate the effects of the results among selected articles. Forest plots, sensitivity analysis and bias analysis for the articles included were also conducted.

RESULTS

Finally, 10 eligible studies were eventually satisfied the included criteria. The results showed that rhEPO was much higher than placebo group in composite cognitive score (MD = 5.89, 95% confidential interval {CI} [1.95, 9.82], P = .003; I2 = 89%), there was no significant difference between rhEPO and placebo groups (RR = 0.93, 95% CI [0.60, 1.43], P = .74; I2 = 51%) and no difference in neurodevelopmental impairment between rhEPO and placebo was insignificant (RR = 0.55 95% CI [0.30, 1.02], P = .06). Composite cognitive score in high dose rhEPO was much higher than placebo group (MD = 10.39, 95% CI [8.84, 11.93], P < .0001, I2 = 0%) and low dose rhEPO also had higher composite cognitive score than placebo group (MD = 2.58, 95% CI [0.80, 4.37], P = .004, I2 = 11%). Limited publication bias was observed in this study.

CONCLUSION

Recombinant human erythropoietin might be a promotor for neurodevelopment among premature infants with limited adverse events.

Anemia of Prematurity and Oral Feeding Milestones in Premature Infants

OBJECTIVE

Anemia of prematurity (AOP) and oral feeding problems are common in premature infants. This study aimed to determine the influence of AOP on aerodigestive outcomes and the duration to full Per Oral (PO).

STUDY DESIGN

Prospectively collected data on premature infants who initiated oral feeds at ≤ 34 weeks' postmenstrual age were examined. Infants were categorized into "AOP+" and "AOP-" based on hematocrit at initial PO, that is, < 29 or ≥ 29%.

RESULTS

Forty-four infants in AOP+ compared with 74 in AOP-. AOP+ infants had lower birth gestation and weight (p < 0.001). The anthropometrics at initial PO were similar. AOP+ had lower mean hematocrit and higher oxygen need at initial PO, and at full PO (p < 0.05). AOP+ reached full PO at a later gestation and took longer days from initial PO to full PO (p < 0.01). BPD, intraventricular hemorrhage (IVH ≤ 2), and hospital stay were greater in the AOP+ (p < 0.05). After adjusting for covariates, initial PO hematocrit was not predictive of time to full PO [hazard ratio 1.3 (CI 0.88-2.0), p = 0.18].

CONCLUSION

AOP is not independently associated with the duration to full PO. Supplemental oxygen for associated comorbidities may have compensated for the underlying anemia.

Sustained low-dose prophylactic early erythropoietin for improvement of neurological outcomes in preterm infants:A systematic review and meta-analysis

The aim of this meta-analysis was conducted to assess the effects of different doses of prophylactic rhEPO on neurodevelopmental outcomes and provide reference for rational drug use. The primary outcome was the number of infants with a Mental Developmental Index (MDI) <70 on the Bayley Scales of Infant Development. Five RCTs, comprising 2282 infants, were included in this meta-analysis. Overall, prophylactic rhEPO administration reduced the incidence of infants with an MDI <70, with an odds ratio (95% confidence interval) of 0.55 (0.38-0.79), P <0.05. The low-dose rhEPO subgroup was superior to the placebo subgroup, with an OR (95% CI) of 0.47 (0.25-0.87), P <0.05. However, high-dose rhEPO subgroup had no significant impact on MDI <70 in infants <28 weeks' gestational age. The definitions of the secondary outcome showed that there was no significant effect of rhEPO on cerebral palsy. For neonatal complications, although four studies showed that there were no differences in the pooled results of BPD and ICH events between rhEPO treatment and placebo, the ICH events were significantly lower in the low-dose rhEPO (OR 0.36; 95% CI 0.23-0.59). In addition, in the pooled results of NEC and ROP events, there were significant differences between the two groups (OR 0.63; 95% CI 0.43-0.93) (OR 0.80; 95% CI 0.65-0.98). And the NEC events were significantly lower in the low-dose rhEPO (OR 0.45; 95% CI 0.27-0.73). Sustained low-dose prophylactic early erythropoietin might be more superior than high-dose for improvement of neurological outcomes and several neonatal complications in preterm infants.

Preventing Brain Injury in the Preterm Infant-Current Controversies and Potential Therapies

Preterm birth is associated with a high risk of morbidity and mortality including brain damage and cerebral palsy. The development of brain injury in the preterm infant may be influenced by many factors including perinatal asphyxia, infection/inflammation, chronic hypoxia and exposure to treatments such as mechanical ventilation and corticosteroids. There are currently very limited treatment options available. In clinical trials, magnesium sulfate has been associated with a small, significant reduction in the risk of cerebral palsy and gross motor dysfunction in early childhood but no effect on the combined outcome of death or disability, and longer-term follow up to date has not shown improved neurological outcomes in school-age children. Recombinant erythropoietin has shown neuroprotective potential in preclinical studies but two large randomized trials, in extremely preterm infants, of treatment started within 24 or 48 h of birth showed no effect on the risk of severe neurodevelopmental impairment or death at 2 years of age. Preclinical studies have highlighted a number of promising neuroprotective treatments, such as therapeutic hypothermia, melatonin, human amnion epithelial cells, umbilical cord blood and vitamin D supplementation, which may be useful at reducing brain damage in preterm infants. Moreover, refinements of clinical care of preterm infants have the potential to influence later neurological outcomes, including the administration of antenatal and postnatal corticosteroids and more accurate identification and targeted treatment of seizures.

Amniotic fluid stem cells as a novel strategy for the treatment of fetal and neonatal neurological diseases

Even in the context of modern medicine, infants with fetal and neonatal neurological diseases such as cerebral palsy and myelomeningocele suffer serious long-lasting impairment due to the irreversible neuronal damage. The promotion of neurologically intact survival in patients with perinatal intractable neurological diseases requires the development of novel strategies. One promising strategy involves the use of human amniotic fluid stem cells (hAFSCs), which have attracted much attention in recent years and are known to exert anti-inflammatory and neuroprotective effects. In recent years, the therapeutic effects of hAFSCs on fetal-neonatal neurological diseases have become evident as per intense research efforts by our group and others. Specifically, hAFSCs administered into the nasal cavity migrated to the brain and controlled local inflammation in a rodent model of neonatal hypoxic-ischemic encephalopathy. In contrast, hAFSCs administered intraperitoneally did not migrate to the brain; they rather formed spheroids in the abdominal cavity, resulting in the suppression of systemic inflammation (including in the brain) via the secretion of anti-inflammatory cytokines in concert with peritoneal macrophages in a rodent model of periventricular leukomalacia. Moreover, studies in a rat model of myelomeningocele suggested that hAFSCs administered in utero secreted hepatocyte growth factor and protected the exposed spinal cord during pregnancy. Importantly, autologous hAFSCs, whose use for fetal-neonatal treatment does not raise ethical issues, can be collected during pregnancy and prepared in sufficient numbers for therapeutic use. This article outlines the results of preclinical research on fetal stem cell therapy, mainly involving hAFSCs, in the context of perinatal neurological diseases.

Is the erythropoietin-erythroferrone-hepcidin axis intact in human neonates?

In a two-part process, we assessed elements of the principal hormonal pathway regulating iron homeostasis in human neonates. Part 1: Quantifying erythropoietin (Epo), erythroferrone (ERFE), hepcidin, and relevant serum and erythrocytic iron-related metrics in umbilical cord blood from term (n = 13) and preterm (n = 10) neonates, and from neonates born to mothers with diabetes and obesity (n = 13); Part 2: Quantifying serum Epo, ERFE, and hepcidin before and following darbepoetin administration. Part 1: We measured Epo, ERFE and hepcidin in all cord blood samples. Epo and ERFE levels did not differ between the three groups. Preterm neonates had the lowest hepcidin levels, while neonates born to diabetic women with a very high BMI had the lowest ferritin and RET-He levels. Part 2: Following darbepoetin dosing, ERFE levels generally increased (p < 0.05) and hepcidin levels generally fell (p < 0.05). Our observations suggest that the Epo/ERFE/hepcidin axis is intact in the newborn period.

Erythropoietin monotherapy for neuroprotection after neonatal encephalopathy in low-to-middle income countries: a systematic review and meta-analysis

OBJECTIVE

We examined whether erythropoietin monotherapy improves neurodevelopmental outcomes in near-term and term infants with neonatal encephalopathy (NE) in low-middle income countries (LMICs).

METHODS

We searched Pubmed, Embase, and Web of Science databases to identify studies that used erythropoietin (1500-12,500 units/kg/dose) or a derivative to treat NE.

RESULTS

Five studies, with a total of 348 infants in LMICs, were retrieved. However, only three of the five studies met the primary outcome of death or neuro-disability at 18 months of age or later. Erythropoietin reduced the risk of death (during the neonatal period and at follow-up) or neuro-disability at 18 months or later (p < 0.05). Death or neuro-disability occurred in 27.6% of the erythropoietin group and 49.7% of the comparison group (risk ratio 0.56 (95% CI: 0.42-0.75)).

CONCLUSION

The pooled data suggest that erythropoietin monotherapy may improve outcomes after NE in LMICs where therapeutic hypothermia is not available.

Erythropoietin Improves Poor Outcomes in Preterm Infants with Intraventricular Hemorrhage

BACKGROUND

Intraventricular hemorrhage (IVH) is a common complication in preterm infants that has poor outcomes, especially in severe cases, and there are currently no widely accepted effective treatments. Erythropoietin has been shown to be neuroprotective in neonatal brain injury.

OBJECTIVE

The objective of this study was to evaluate the protective effect of repeated low-dose recombinant human erythropoietin (rhEPO) in preterm infants with IVH.

METHODS

This was a single-blinded prospective randomized controlled trial. Preterm infants ≤ 32 weeks gestational age who were diagnosed with IVH within 72 h after birth were randomized to receive rhEPO 500 IU/kg or placebo (equivalent volume of saline) every other day for 2 weeks. The primary outcome was death or neurological disability assessed at 18 months of corrected age.

RESULTS

A total of 316 eligible infants were included in the study, with 157 in the rhEPO group and 159 in the placebo group. Although no significant differences in mortality (p = 0.176) or incidence of neurological disability (p = 0.055) separately at 18 months of corrected age were seen between the rhEPO and placebo groups, significantly fewer infants had poor outcomes (death and neurological disability) in the rhEPO group: 14.9 vs. 26.4%; odds ratio (OR) 0.398; 95% confidence interval (CI) 0.199-0.796; p = 0.009. In addition, the incidence of Mental Development Index scores of < 70 was lower in the rhEPO group than in the placebo group: 7.2 vs. 15.3%; OR 0.326; 95% CI 0.122-0.875; p = 0.026.

CONCLUSIONS

Treatment with repeated low-dose rhEPO improved outcomes in preterm infants with IVH.

TRIAL REGISTRATION

The study was retrospectively registered on ClinicalTrials.gov on 16 April 2019 (NCT03914690).

Prophylactic Erythropoietin for Neuroprotection in Very Preterm Infants: A Meta-Analysis Update

A meta-analysis update of randomized controlled trials investigating recombinant human erythropoietin suggests improved neurodevelopmental outcome in preterm infants. There was substantial heterogeneity, which could be ascribed to a single trial. Exclusion of this trial featuring a high risk of bias abolished heterogeneity and any effects of recombinant human erythropoietin treatment.

Transfusion in Neonatal Patients: Review of Evidence-Based Guidelines

Transfusion of red blood cells, platelets, and fresh frozen plasma in neonatal patients has not been well characterized in the literature, with guidelines varying greatly between institutions. However, anemia and thrombocytopenia are highly prevalent, especially in preterm neonates. When transfusing a neonatal patient, clinicians must take into consideration physiologic differences, gestational and postnatal age, congenital disorders, and maternal factors while weighing the risks and benefits of transfusion. This review of existing literature summarizes current evidence-based neonatal transfusion guidelines and highlights areas of current ongoing research and those in need of future studies.

Umbilical cord blood cells for the treatment of preterm white matter injury: Potential effects and treatment options

Preterm birth is a global public health problem. A large number of preterm infants survive with preterm white matter injury (PWMI), which leads to neurological deficits, and has multifaceted etiology, clinical course, monitoring, and outcomes. The principal upstream insults leading to PWMI initiation are hypoxia-ischemia and infection and/or inflammation and the key target cells are late oligodendrocyte precursor cells. Current PWMI treatments are mainly supportive, and thus have little effect in terms of protecting the immature brain or repairing injury to improve long-term outcomes. Umbilical cord blood (UCB) cells comprise abundant immunomodulatory and stem cells, which have the potential to reduce brain injury, mainly due to anti-inflammatory and immunomodulatory mechanisms, and also through their release of neurotrophic or growth factors to promote endogenous neurogenesis. In this review, we briefly summarize PWMI pathogenesis and pathophysiology, and the specific properties of different cell types in UCB. We further explore the potential mechanism by which UCB can be used to treat PWMI, and discuss the advantages of and potential issues related to UCB cell therapy. Finally, we suggest potential future studies of UCB cell therapy in preterm infants.

High-Dose Erythropoietin in Extremely Low Gestational Age Neonates Does Not Alter Risk of Retinopathy of Prematurity

INTRODUCTION

The Preterm Erythropoietin (Epo) Neuroprotection (PENUT) Trial sought to determine the safety and efficacy of early high-dose Epo as a potential neuroprotective treatment. We hypothesized that Epo would not increase the incidence or severity of retinopathy of prematurity (ROP).

METHODS

A total of 941 infants born between 24-0/7 and 27-6/7 weeks' gestation were randomized to 1,000 U/kg Epo or placebo intravenously for 6 doses, followed by subcutaneous or sham injections of 400 U/kg Epo 3 times a week through 32 weeks post-menstrual age. In this secondary analysis of PENUT trial data, survivors were evaluated for ROP. A modified intention-to-treat approach was used to compare treatment groups. In addition, risk factors for ROP were evaluated using regression methods that account for multiples and allow for adjustment for treatment and gestational age at birth.

RESULTS

Of 845 subjects who underwent ROP examination, 503 were diagnosed with ROP with similar incidence and severity between treatment groups. Gestational age at birth, birth weight, prenatal magnesium sulfate, maternal antibiotic exposure, and presence of heart murmur at 2 weeks predicted the development of any ROP, while being on high-frequency oscillator or high-frequency jet ventilation (HFOV/HFJV) at 2 weeks predicted severe ROP.

CONCLUSION

Early high-dose Epo followed by maintenance dosing through 32 weeks does not increase the risk of any or severe ROP in extremely low gestational age neonates. Gestational age, birth weight, maternal treatment with magnesium sulfate, antibiotic use during pregnancy, and presence of a heart murmur at 2 weeks were associated with increased risk of any ROP. Treatment with HFOV/HFJV was associated with an increased risk of severe ROP.

Update on Erythropoiesis-Stimulating Agents Administered to Neonates for Neuroprotection

Erythropoiesis-stimulating agents (ESAs) such as erythropoietin and darbepoetin have been studied as red blood cell growth factors in preterm and term infants for more than 30 years. Recently, studies have focused on the potential neuroprotective effects of ESAs. In this review, we summarize preclinical animal models and recent clinical trials that provide evidence for ESAs as potential treatments to improve neurodevelopmental outcomes in preterm and term infants.

Erythropoietin prevents necrotizing enterocolitis in very preterm infants: a randomized controlled trial

Background

Necrotizing enterocolitis (NEC) is one of the most severe complications in very preterm infants, but there are currently no accepted methods to prevent NEC. Studies have shown that erythropoietin (EPO) has the potential to prevent NEC or improve outcomes of preterm NEC. This study aimed to determine whether recombinant human EPO (rhEPO) could protect against NEC in very preterm infants.

Methods

The study was a prospective randomized clinical trial performed among four NICU centers. A total of 1327 preterm infants with gestational age ≤ 32 weeks were admitted to the centers, and 42 infants were excluded leaving 1285 eligible infants to be randomized to the rhEPO or control group. Infants in the rhEPO group were given 500 IU/kg rhEPO intravenously every other day for 2 weeks, while the control group was given the same volume of saline. The primary outcome was the incidence of NEC in very preterm infants at 36 weeks of corrected gestational age.

Results

A total of 1285 infants were analyzed at 36 weeks of corrected age for the incidence of NEC. rhEPO treatment significantly decreased the incidence of NEC (stage I, II and III) (12.0% vs. 17.1%, p = 0.010), especially confirmed NEC (stage II and III) (3.0% vs. 5.4%, p = 0.027). Meanwhile, rhEPO treatment significantly reduced the number of red blood cells transfusion in the confirmed NEC cases (1.2 ± 0.4 vs. 2.7 ± 1.0, p = 0.004). Subgroup analyses showed that rhEPO treatment significantly decreased the incidence of confirmed NEC at gestational age < 28 weeks (p = 0.019), and the incidence of all stages NEC in preterm infants with hemoglobin < 90 g/l (p = 0.000) and 5 min Apgar score > 5 (p = 0.028).

Conclusion

Repeated low-dose rhEPO treatment is beneficial against NEC in very preterm infants.

Trial registration The protocol was registered retrospectively at ClinicalTrials.gov (NCT03919500) on April 18, 2019. https://clinicaltrials.gov/ct2/show/NCT03919500

Early working memory is a significant predictor of verbal and processing skills at 6-7 years in children born extremely preterm

OBJECTIVE

The study was designed to investigate whether attainment of object permanence, a measure of early working memory used at 18-22 months corrected age, was associated with executive function at 6-7 years in a cohort of children born extremely preterm.

STUDY DESIGN

Children enrolled in the Neuroimaging and Neurodevelopmental Outcome (NEURO) study, a secondary study to the Surfactant Positive Airway Pressure and Pulse Oximetry Trial (SUPPORT) of the NICHD NRN, were eligible for this longitudinal study. Testing completed at 18 to 22 months corrected age was compared to testing at school age with a specific focus on measures of executive function.

RESULTS

Children who had achieved object permanence mastery at a corrected age of 18-22 months had higher mean scores on the WISC-IV tests of verbal comprehension and processing speed at age 6-7 years. Regression models indicated that object permanence scores were significant predictors of both verbal comprehension and processing speeds scores, after controlling for other factors. When analyzed by subgroup for sex, these results were significant for girls but not for boys.

CONCLUSIONS

This study found that an early mastery of object permanence was associated with higher scores in areas of verbal comprehension and processing speed in girls. These results have implications for potentially identifying young children born preterm that are at greater risk for difficulties with cognitive and working memory skills at school age.

Treatment of Neonatal Hypoxic-Ischemic Encephalopathy with Erythropoietin Alone, and Erythropoietin Combined with Hypothermia: History, Current Status, and Future Research

Perinatal hypoxic-ischemic encephalopathy (HIE) remains a major cause of morbidity and mortality. Moderate hypothermia (33.5 °C) is currently the sole established standard treatment. However, there are a large number of infants for whom this therapy is ineffective. This inspired global research to find neuroprotectants to potentiate the effect of moderate hypothermia. Here we examine erythropoietin (EPO) as a prominent candidate. Neonatal animal studies show that immediate, as well as delayed, treatment with EPO post-injury, can be neuroprotective and/or neurorestorative. The observed improvements of EPO therapy were generally not to the level of control uninjured animals, however. This suggested that combining EPO treatment with an adjunct therapeutic strategy should be researched. Treatment with EPO plus hypothermia led to less cerebral palsy in a non-human primate model of perinatal asphyxia, leading to clinical trials. A recent Phase II clinical trial on neonatal infants with HIE reported better 12-month motor outcomes for treatment with EPO plus hypothermia compared to hypothermia alone. Hence, the effectiveness of combined treatment with moderate hypothermia and EPO for neonatal HIE currently looks promising. The outcomes of two current clinical trials on neurological outcomes at 18-24 months-of-age, and at older ages, are now required. Further research on the optimal dose, onset, and duration of treatment with EPO, and critical consideration of the effect of injury severity and of gender, are also required.

Early erythropoiesis-stimulating agents in preterm or low birth weight infants

BACKGROUND

Preterm infants have low plasma levels of erythropoietin (EPO), providing a rationale for the use of erythropoiesis-stimulating agents (ESAs) to prevent or treat anaemia and to provide neuro protection and protection against necrotising enterocolitis (NEC). Darbepoetin (Darbe) and EPO are currently available ESAs.

OBJECTIVES

To assess the effectiveness and safety of ESAs (erythropoietin (EPO) and/or Darbe) initiated early (before eight days after birth) compared with placebo or no intervention in reducing red blood cell (RBC) transfusions, adverse neurological outcomes, and feeding intolerance including necrotising enterocolitis (NEC) in preterm and/or low birth weight infants. Primary objective for studies that primarily investigate the effectiveness and safety of ESAs administered early in reducing red blood cell transfusions: To assess the effectiveness and safety of ESAs initiated early in reducing red blood cell transfusions in preterm infants. Secondary objectives: Review authors performed subgroup analyses of low (≤ 500 IU/kg/week) and high (> 500 IU/kg/week) doses of EPO and the amount of iron supplementation provided: none, low (≤ 5 mg/kg/d), and high (> 5 mg/kg/d). Primary objective for studies that primarily investigate the neuro protective effectiveness of ESAs: To assess the effectiveness and safety of ESAs initiated early in reducing adverse neurological outcomes in preterm infants. Primary objective for studies that primarily investigate the effectiveness of EPO or Darbe administered early in reducing feeding intolerance: To assess the effectiveness and safety of ESAs administered early in reducing feeding intolerance (and NEC) in preterm infants. Other secondary objectives: To compare the effectiveness of ESAs in reducing the incidence of adverse events and improving long-term neurodevelopmental outcomes.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE via PubMed (1966 to 10 March 2017), Embase (1980 to 10 March 2017), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 10 March 2017). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised and quasi-randomised controlled trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of early initiation of EAS treatment versus placebo or no intervention in preterm or low birth weight infants.

DATA COLLECTION AND ANALYSIS

We used the methods described in the Cochrane Handbook for Systematic Reviews of Interventions and the GRADE approach to assess the quality of evidence.

MAIN RESULTS

This updated review includes 34 studies enrolling 3643 infants. All analyses compared ESAs versus a control consisting of placebo or no treatment. Early ESAs reduced the risk of 'use of one or more [red blood cell] RBC transfusions' (typical risk ratio (RR) 0.79, 95% confidence interval (CI) 0.74 to 0.85; typical risk difference (RD) -0.14, 95% CI -0.18 to -0.10; I2 = 69% for RR and 62% for RD (moderate heterogeneity); number needed to treat for an additional beneficial outcome (NNTB) 7, 95% CI 6 to 10; 19 studies, 1750 infants). The quality of the evidence was low. Necrotising enterocolitis was significantly reduced in the ESA group compared with the placebo group (typical RR 0.69, 95% CI 0.52 to 0.91; typical RD -0.03, 95% CI -0.05 to -0.01; I2 = 0% for RR and 22% for RD (low heterogeneity); NNTB 33, 95% CI 20 to 100; 15 studies, 2639 infants). The quality of the evidence was moderate. Data show a reduction in 'Any neurodevelopmental impairment at 18 to 22 months' corrected age in the ESA group (typical RR 0.62, 95% CI 0.48 to 0.80; typical RD -0.08, 95% CI -0.12 to -0.04; NNTB 13, 95% CI 8 to 25. I2 = 76% for RR (high heterogeneity) and 66% for RD (moderate); 4 studies, 1130 infants). The quality of the evidence was low. Results reveal increased scores on the Bayley-II Mental Development Index (MDI) at 18 to 24 months in the ESA group (weighted mean difference (WMD) 8.22, 95% CI 6.52 to 9.92; I2 = 97% (high heterogeneity); 3 studies, 981 children). The quality of the evidence was low. The total volume of RBCs transfused per infant was reduced by 7 mL/kg. The number of RBC transfusions per infant was minimally reduced, but the number of donors to whom infants who were transfused were exposed was not significantly reduced. Data show no significant difference in risk of stage ≥ 3 retinopathy of prematurity (ROP) with early EPO (typical RR 1.24, 95% CI 0.81 to 1.90; typical RD 0.01, 95% CI -0.02 to 0.04; I2 = 0% (no heterogeneity) for RR; I2 = 34% (low heterogeneity) for RD; 8 studies, 1283 infants). Mortality was not affected, but results show significant reductions in the incidence of intraventricular haemorrhage (IVH) and periventricular leukomalacia (PVL).

AUTHORS' CONCLUSIONS

Early administration of ESAs reduces the use of red blood cell (RBC) transfusions, the volume of RBCs transfused, and donor exposure after study entry. Small reductions are likely to be of limited clinical importance. Donor exposure probably is not avoided, given that all but one study included infants who had received RBC transfusions before trial entry. This update found no significant difference in the rate of ROP (stage ≥ 3) for studies that initiated EPO treatment at less than eight days of age, which has been a topic of concern in earlier versions of this review. Early EPO treatment significantly decreased rates of IVH, PVL, and NEC. Neurodevelopmental outcomes at 18 to 22 months and later varied in published studies. Ongoing research should evaluate current clinical practices that will limit donor exposure. Promising but conflicting results related to the neuro protective effect of early EPO require further study. Very different results from the two largest published trials and high heterogeneity in the analyses indicate that we should wait for the results of two ongoing large trials before drawing firm conclusions. Administration of EPO is not currently recommended because limited benefits have been identified to date. Use of darbepoetin requires further study.

A Randomized Trial of Erythropoietin for Neuroprotection in Preterm Infants

BACKGROUND

High-dose erythropoietin has been shown to have a neuroprotective effect in preclinical models of neonatal brain injury, and phase 2 trials have suggested possible efficacy; however, the benefits and safety of this therapy in extremely preterm infants have not been established.

METHODS

In this multicenter, randomized, double-blind trial of high-dose erythropoietin, we assigned 941 infants who were born at 24 weeks 0 days to 27 weeks 6 days of gestation to receive erythropoietin or placebo within 24 hours after birth. Erythropoietin was administered intravenously at a dose of 1000 U per kilogram of body weight every 48 hours for a total of six doses, followed by a maintenance dose of 400 U per kilogram three times per week by subcutaneous injection through 32 completed weeks of postmenstrual age. Placebo was administered as intravenous saline followed by sham injections. The primary outcome was death or severe neurodevelopmental impairment at 22 to 26 months of postmenstrual age. Severe neurodevelopmental impairment was defined as severe cerebral palsy or a composite motor or composite cognitive score of less than 70 (which corresponds to 2 SD below the mean, with higher scores indicating better performance) on the Bayley Scales of Infant and Toddler Development, third edition.

RESULTS

A total of 741 infants were included in the per-protocol efficacy analysis: 376 received erythropoietin and 365 received placebo. There was no significant difference between the erythropoietin group and the placebo group in the incidence of death or severe neurodevelopmental impairment at 2 years of age (97 children [26%] vs. 94 children [26%]; relative risk, 1.03; 95% confidence interval, 0.81 to 1.32; P = 0.80). There were no significant differences between the groups in the rates of retinopathy of prematurity, intracranial hemorrhage, sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, or death or in the frequency of serious adverse events.

CONCLUSIONS

High-dose erythropoietin treatment administered to extremely preterm infants from 24 hours after birth through 32 weeks of postmenstrual age did not result in a lower risk of severe neurodevelopmental impairment or death at 2 years of age. (Funded by the National Institute of Neurological Disorders and Stroke; PENUT ClinicalTrials.gov number, NCT01378273.).

Neuroprotection Strategies in Preterm Encephalopathy

Advances in neonatology have led to unprecedented improvements in neonatal survival such that those born as early as 22 weeks of gestation now have some chance of survival, and over 70% of those born at 24 weeks of gestation survive. Up to 50% of infants born extremely preterm develop poor outcomes involving long-term neurodevelopmental impairments affecting cognition and learning, or motor problems such as cerebral palsy. Poor outcomes arise because the preterm brain is vulnerable both to direct injury (by events such as intracerebral hemorrhage, infection, and/or hypoxia), or indirect injury due to disruption of normal development. This neonatal brain injury and/or dysmaturation is called "encephalopathy of prematurity". Current and future strategies to improve outcomes in this population include prevention of preterm birth, and pre-, peri-, and postnatal approaches to protect the developing brain. This review will describe mechanisms of preterm brain injury, and current and upcoming therapies in the antepartum and postnatal period to improve preterm encephalopathy.

Recent advances in perinatal neuroprotection

Perinatal brain injury is a major cause of neurological disability in both premature and term infants. In this review, we summarize the evidence behind some established neuroprotective practices such as administration of antenatal steroids, intrapartum magnesium for preterm delivery, and therapeutic hypothermia. In addition, we examine emerging practices such as delayed cord clamping, postnatal magnesium administration, recombinant erythropoietin, and non-steroidal anti-inflammatory agents and finally inform the reader about novel interventions, some of which are currently in trials, such as xenon, melatonin, topiramate, allopurinol, creatine, and autologous cord cell therapy.

Medicinal Uses of Hematopoietic Growth Factors in Neonatal Medicine

This review focuses on certain hematopoietic growth factors that are used as medications in clinical neonatology. It is important to note at the chapter onset that although all of the pharmacological agents mentioned in this review have been approved by the US Food and Drug administration for use in humans, none have been granted a specific FDA indication for neonates. Thus, in a sense, all of the agents mentioned in this chapter could be considered experimental, when used in neonates. However, a great many of the pharmacological agents utilized routinely in neonatology practice do not have a specific FDA indication for this population of patients. Consequently, many of the agents reviewed in this chapter are considered by some practitioners to be nonexperimental and are used when they judge such use to be "best practice" for the disorders under treatment.The medicinal uses of the agents in this chapter vary considerably, between geographic locations, and sometimes even within an institutions. "Consistent approaches" aimed at using these agents in uniform ways in the practice of neonatology are encouraged. Indeed some healthcare systems, and some individual NICUs, have developed written guidelines for using these agents within the practice group. Some such guidelines are provided in this review. It should be noted that these guidelines, or "consistent approaches," must be viewed as dynamic and changing, requiring adjustment and refinement as additional evidence accrues.

Pharmacologic Prevention and Treatment of Neonatal Brain Injury

Neonatal brain injury (NBI) remains a major contributor to neonatal mortality and long-term neurodevelopmental morbidity. Although therapeutic hypothermia is the only proven treatment to minimize brain injury caused by neonatal encephalopathy in term neonates, it provides incomplete neuroprotection. There are no specific drugs yet proven to prevent NBI in preterm neonates. This review discusses the scientific and emerging clinical trial data for several neuroprotective drugs in development, examining potential efficacy and safety concerns. Drugs with the highest likelihood of success and closest to clinical application include erythropoietin for term and preterm neonates and antenatal magnesium for preterm neonates.

Time to reconsider extended erythropoietin treatment for infantile traumatic brain injury?

Pediatric traumatic brain injury (TBI) remains a leading cause of childhood morbidity and mortality worldwide. Most efforts to reduce the chronic impact of pediatric TBI involve prevention and minimization of secondary injury. Currently, no treatments are used in routine clinical care during the acute and subacute phases to actively repair injury to the developing brain. The endogenous pluripotent cytokine erythropoietin (EPO) holds promise as an emerging neuroreparative agent in perinatal brain injury (PBI). EPO signaling in the central nervous system (CNS) is essential for multiple stages of neurodevelopment, including the genesis, survival and differentiation of multiple lineages of neural cells. Postnatally, EPO signaling decreases markedly as the CNS matures. Importantly, high-dose, extended EPO regimens have shown efficacy in preclinical controlled cortical impact (CCI) models of infant TBI at two different, early ages by independent research groups. Specifically, extended high-dose EPO treatment after infantile CCI prevents long-term cognitive deficits in adult rats. Because of the striking differences in the molecular and cellular responses to both injury and recovery in the developing and mature CNS, and the excellent safety profile of EPO in infants and children, extended courses of EPO are currently in Phase III trials for neonates with PBI. Extended, high-dose EPO may also warrant testing for infants and young children with TBI.

The optimal choices of animal models of white matter injury

White matter injury, the most common neurological injury in preterm infants, is a major cause of chronic neurological morbidity, including cerebral palsy. Although there has been great progress in the study of the mechanism of white matter injury in newborn infants, its pathogenesis is not entirely clear, and further treatment approaches are required. Animal models are the basis of study in pathogenesis, treatment, and prognosis of white matter injury in preterm infants. Various species have been used to establish white matter injury models, including rodents, rabbits, sheep, and non-human primates. Small animal models allow cost-effective investigation of molecular and cellular mechanisms, while large animal models are particularly attractive for pathophysiological and clinical-translational studies. This review focuses on the features of commonly used white matter injury animal models, including their modelling methods, advantages, and limitations, and addresses some clinically relevant animal models that allow reproduction of the insults associated with clinical conditions that contribute to white matter injury in human infants.

Extended Combined Neonatal Treatment With Erythropoietin Plus Melatonin Prevents Posthemorrhagic Hydrocephalus of Prematurity in Rats

Posthemorrhagic hydrocephalus of prematurity (PHHP) remains a global challenge. Early preterm infants (<32 weeks gestation), particularly those exposed to chorioamnionitis (CAM), are prone to intraventricular hemorrhage (IVH) and PHHP. We established an age-appropriate, preclinical model of PHHP with progressive macrocephaly and ventriculomegaly to test whether non-surgical neonatal treatment could modulate PHHP. We combined prenatal CAM and postnatal day 1 (P1, equivalent to 30 weeks human gestation) IVH in rats, and administered systemic erythropoietin (EPO) plus melatonin (MLT), or vehicle, from P2 to P10. CAM-IVH rats developed progressive macrocephaly through P21. Macrocephaly was accompanied by ventriculomegaly at P5 (histology), and P21 (ex vivo MRI). CAM-IVH rats showed impaired performance of cliff aversion, a neonatal neurodevelopmental test. Neonatal EPO+MLT treatment prevented macrocephaly and cliff aversion impairment, and significantly reduced ventriculomegaly. EPO+MLT treatment prevented matted or missing ependymal motile cilia observed in vehicle-treated CAM-IVH rats. EPO+MLT treatment also normalized ependymal yes-associated protein (YAP) mRNA levels, and reduced ependymal GFAP-immunolabeling. Vehicle-treated CAM-IVH rats exhibited loss of microstructural integrity on diffusion tensor imaging, which was normalized in EPO+MLT-treated CAM-IVH rats. In summary, combined prenatal systemic inflammation plus early postnatal IVH caused progressive macrocephaly, ventriculomegaly and delayed development of cliff aversion reminiscent of PHHP. Neonatal systemic EPO+MLT treatment prevented multiple hallmarks of PHHP, consistent with a clinically viable, non-surgical treatment strategy.

Therapeutic strategies to target acute and long-term sequelae of pediatric traumatic brain injury

Pediatric traumatic brain injury (TBI) remains one of the leading causes of morbidity and mortality in children. Experimental and clinical studies demonstrate that the developmental age, the type of injury (diffuse vs. focal) and sex may play important roles in the response of the developing brain to a traumatic injury. Advancements in acute neurosurgical interventions and neurocritical care have improved and led to a decrease in mortality rates over the past decades. However, survivors are left with life-long behavioral deficits underscoring the need to better define the cellular mechanisms underlying these functional changes. A better understanding of these mechanisms some of which begin in the acute post-traumatic period may likely lead to targeted treatment strategies. Key considerations in designing pre-clinical experiments to test therapeutic strategies in pediatric TBI include the use of age-appropriate and pathologically-relevant models, functional outcomes that are tested as animals age into adolescence and beyond, sex as a biological variable and the recognition that doses and dosing strategies that have been demonstrated to be effective in animal models of adult TBI may not be effective in the developing brain. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".

Extended Erythropoietin Treatment Prevents Chronic Executive Functional and Microstructural Deficits Following Early Severe Traumatic Brain Injury in Rats

Survivors of infant traumatic brain injury (TBI) are prone to chronic neurological deficits that impose lifelong individual and societal burdens. Translation of novel interventions to clinical trials is hampered in part by the lack of truly representative preclinical tests of cognition and corresponding biomarkers of functional outcomes. To address this gap, the ability of a high-dose, extended, post-injury regimen of erythropoietin (EPO, 3000U/kg/dose × 6d) to prevent chronic cognitive and imaging deficits was tested in a postnatal day 12 (P12) controlled-cortical impact (CCI) model in rats, using touchscreen operant chambers and regional analysis of diffusion tensor imaging (DTI). Results indicate that EPO prevents functional injury and MRI injury after infant TBI. Specifically, subacute DTI at P30 revealed widespread microstructural damage that is prevented by EPO. Assessment of visual discrimination on a touchscreen operant chamber platform demonstrated that all groups can perform visual discrimination. However, CCI rats treated with vehicle failed to pass reversal learning, and perseverated, in contrast to sham and CCI-EPO rats. Chronic DTI at P90 showed EPO treatment prevented contralateral white matter and ipsilateral lateral prefrontal cortex damage. This DTI improvement correlated with cognitive performance. Taken together, extended EPO treatment restores executive function and prevents microstructural brain abnormalities in adult rats with cognitive deficits in a translational preclinical model of infant TBI. Sophisticated testing with touchscreen operant chambers and regional DTI analyses may expedite translation and effective yield of interventions from preclinical studies to clinical trials. Collectively, these data support the use of EPO in clinical trials for human infants with TBI.

Repetitive Neonatal Erythropoietin and Melatonin Combinatorial Treatment Provides Sustained Repair of Functional Deficits in a Rat Model of Cerebral Palsy

Cerebral palsy (CP) is the leading cause of motor impairment for children worldwide and results from perinatal brain injury (PBI). To test novel therapeutics to mitigate deficits from PBI, we developed a rat model of extreme preterm birth (<28 weeks of gestation) that mimics dual intrauterine injury from placental underperfusion and chorioamnionitis. We hypothesized that a sustained postnatal treatment regimen that combines the endogenous neuroreparative agents erythropoietin (EPO) and melatonin (MLT) would mitigate molecular, sensorimotor, and cognitive abnormalities in adults rats following prenatal injury. On embryonic day 18 (E18), a laparotomy was performed in pregnant Sprague–Dawley rats. Uterine artery occlusion was performed for 60 min to induce placental insufficiency via transient systemic hypoxia-ischemia, followed by intra-amniotic injections of lipopolysaccharide, and laparotomy closure. On postnatal day 1 (P1), approximately equivalent to 30 weeks of gestation, injured rats were randomized to an extended EPO + MLT treatment regimen, or vehicle (sterile saline) from P1 to P10. Behavioral assays were performed along an extended developmental time course (n = 6–29). Open field testing shows injured rats exhibit hypermobility and disinhibition and that combined neonatal EPO + MLT treatment repairs disinhibition in injured rats, while EPO alone does not. Furthermore, EPO + MLT normalizes hindlimb deficits, including reduced paw area and paw pressure at peak stance, and elevated percent shared stance after prenatal injury. Injured rats had fewer social interactions than shams, and EPO + MLT normalized social drive. Touchscreen operant chamber testing of visual discrimination and reversal shows that EPO + MLT at least partially normalizes theses complex cognitive tasks. Together, these data indicate EPO + MLT can potentially repair multiple sensorimotor, cognitive, and behavioral realms following PBI, using highly translatable and sophisticated developmental testing platforms.

The long-term effect of erythropoiesis stimulating agents given to preterm infants: a proton magnetic resonance spectroscopy study on neurometabolites in early childhood

BACKGROUND

Erythropoiesis stimulating agents (ESAs) are neuroprotective in cell and animal models of preterm birth. Prematurity has been shown to alter neurometabolite levels in children in studies using proton magnetic resonance spectroscopy (1H-MRS).

OBJECTIVE

We hypothesized that ESA treatment in premature infants would tend to normalize neurometabolites by 4-6 years of age.

MATERIALS AND METHODS

Children in a longitudinal study of neurodevelopment underwent MRI and 1H-MRS at approximately 4 years and 6 years of age. Prematurely born children (500-1,250 g birth weight) received ESAs (erythropoietin or darbepoetin) or placebo during their neonatal hospitalization, and these groups were compared to healthy term controls. 1H-MRS spectra were obtained from the anterior cingulate (gray matter) and frontal lobe white matter, assessing combined N-acetylaspartate and N-acetylaspartylglutamate (tNAA), myo-inositol, choline compounds (Cho), combined creatine and phosphocreatine, and combined glutamate and glutamine.

RESULTS

No significant (P≤0.5) group differences were observed for any metabolite level. Significant age-related increases in white-matter tNAA and Cho were observed, as well as a trend for increased gray-matter tNAA.

CONCLUSION

Neither prematurity nor neonatal ESA treatment was associated with differences in brain metabolite levels in the children of this study at a significance level of 0.05. These findings suggest that earlier differences that might have existed had normalized by 4-6 years of age or were too small to be statistically significant in the current sample.

Darbepoetin Alfa in Young Infants With Renal Failure: Single Center Experience, a Case Series and Review of the Literature

Background: Anemia treatment in infants with advanced or chronic kidney disease (CKD) represents an important challenge to nephrologists. The use of darbepoetin alfa, a novel erythropoiesis stimulating agent, has largely replaced recombinant human erythropoietin in older children and in adults with CKD. However, studies reporting the use of darbepoetin alfa in infants below 1 year of age are rare. Case presentation: We report the data of three infants with advanced stage kidney failure, aged 1, 4, and 7 months, who were treated with darbepoetin alfa and followed for 18-41 months. Hemoglobin levels increased in all three patients, reaching the target levels of 10.7-12 g/dl by 11, 19, and 22 weeks respectively, without any documented adverse effects. Patients younger than 1 year of age required a larger darbepoetin alfa dosage (ranged from 1.2 to 2.9 μg/kg per month) as compared to older children. A review of the literature found only three studies using darbepoetin alfa successfully in such young infants, with similar dosage and clinical success. Conclusion: In these three patients with advanced kidney disease, darbepoetin alfa was effective in correcting anemia with no observed side effects. It reinforces its potential use in very young patients with advanced CKD.

Neonatal erythropoietin mitigates impaired gait, social interaction and diffusion tensor imaging abnormalities in a rat model of prenatal brain injury

Children who are born preterm are at risk for encephalopathy of prematurity, a leading cause of cerebral palsy, cognitive delay and behavioral disorders. Current interventions are limited and none have been shown to reverse cognitive and behavioral impairments, a primary determinant of poor quality of life for these children. Moreover, the mechanisms of perinatal brain injury that result in functional deficits and imaging abnormalities in the mature brain are poorly defined, limiting the potential to target interventions to those who may benefit most. To determine whether impairments are reversible after a prenatal insult, we investigated a spectrum of functional deficits and diffusion tensor imaging (DTI) abnormalities in young adult animals. We hypothesized that prenatal transient systemic hypoxia-ischemia (TSHI) would induce multiple functional deficits concomitant with reduced microstructural white and gray matter integrity, and tested whether these abnormalities could be ameliorated using postnatal erythropoietin (EPO), an emerging neurorestorative intervention. On embryonic day 18 uterine arteries were transiently occluded for 60min via laparotomy. Shams underwent anesthesia and laparotomy for 60min. Pups were born and TSHI pups were randomized to receive EPO or vehicle via intraperitoneal injection on postnatal days 1 to 5. Gait, social interaction, olfaction and open field testing was performed from postnatal day 25-35 before brains underwent ex vivo DTI to measure fractional anisotropy, axial diffusivity and radial diffusivity. Prenatal TSHI injury causes hyperactivity, impaired gait and poor social interaction in young adult rats that mimic the spectrum of deficits observed in children born preterm. Collectively, these data show for the first time in a model of encephalopathy of prematurity that postnatal EPO treatment mitigates impairments in social interaction, in addition to gait deficits. EPO also normalizes TSHI-induced microstructural abnormalities in fractional anisotropy and radial diffusivity in multiple regions, consistent with improved structural integrity and recovery of myelination. Taken together, these results show behavioral and memory deficits from perinatal brain injury are reversible. Furthermore, resolution of DTI abnormalities may predict responsiveness to emerging interventions, and serve as a biomarker of CNS injury and recovery.