Effect of allopurinol in addition to hypothermia treatment in neonates for hypoxic-ischemic brain injury on neurocognitive outcome (ALBINO) : Study protocol of a blinded randomized placebo-controlled parallel group multicenter trial for superiority (phase III)

Background: Perinatal asphyxia and resulting hypoxic-ischemic encephalopathy is a major cause of death and long-term disability in term born neonates. Up to 20,000 infants each year are affected by HIE in Europe and even more in regions with lower level of perinatal care. The only established therapy to improve outcome in these infants is therapeutic hypothermia. Allopurinol is a xanthine oxidase inhibitor that reduces the production of oxygen radicals as superoxide, which contributes to secondary energy failure and apoptosis in neurons and glial cells after reperfusion of hypoxic brain tissue and may further improve outcome if administered in addition to therapeutic hypothermia. Methods: This study on the effects of ALlopurinol in addition to hypothermia treatment for hypoxic-ischemic Brain Injury on Neurocognitive Outcome (ALBINO), is a European double-blinded randomized placebo-controlled parallel group multicenter trial (Phase III) to evaluate the effect of postnatal allopurinol administered in addition to standard of care (including therapeutic hypothermia if indicated) on the incidence of death and severe neurodevelopmental impairment at 24 months of age in newborns with perinatal hypoxic-ischemic insult and signs of potentially evolving encephalopathy. Allopurinol or placebo will be given in addition to therapeutic hypothermia (where indicated) to infants with a gestational age ≥ 36 weeks and a birth weight ≥ 2500 g, with severe perinatal asphyxia and potentially evolving encephalopathy. The primary endpoint of this study will be death or severe neurodevelopmental impairment versus survival without severe neurodevelopmental impairment at the age of two years. Effects on brain injury by magnetic resonance imaging and cerebral ultrasound, electric brain activity, concentrations of peroxidation products and S100B, will also be studied along with effects on heart function and pharmacokinetics of allopurinol after iv-infusion. Discussion: This trial will provide data to assess the efficacy and safety of early postnatal allopurinol in term infants with evolving hypoxic-ischemic encephalopathy. If proven efficacious and safe, allopurinol could become part of a neuroprotective pharmacological treatment strategy in addition to therapeutic hypothermia in children with perinatal asphyxia. Trial registration: NCT03162653, www.ClinicalTrials.gov, May 22, 2017. © 2019 The Author(s).Peer reviewe

Extremely Preterm Infant Admissions Within the SafeBoosC-III Consortium During the COVID-19 Lockdown

Objective: To evaluate if the number of admitted extremely preterm (EP) infants (born before 28 weeks of gestational age) differed in the neonatal intensive care units (NICUs) of the SafeBoosC-III consortium during the global lockdown when compared to the corresponding time period in 2019. Design: This is a retrospective, observational study. Forty-six out of 79 NICUs (58%) from 17 countries participated. Principal investigators were asked to report the following information: (1) Total number of EP infant admissions to their NICU in the 3 months where the lockdown restrictions were most rigorous during the first phase of the COVID-19 pandemic, (2) Similar EP infant admissions in the corresponding 3 months of 2019, (3) the level of local restrictions during the lockdown period, and (4) the local impact of the COVID-19 lockdown on the everyday life of a pregnant woman. Results: The number of EP infant admissions during the first wave of the COVID-19 pandemic was 428 compared to 457 in the corresponding 3 months in 2019 (−6.6%, 95% CI −18.2 to +7.1%, p = 0.33). There were no statistically significant differences within individual geographic regions and no significant association between the level of lockdown restrictions and difference in the number of EP infant admissions. A post-hoc analysis based on data from the 46 NICUs found a decrease of 10.3%in the total number of NICU admissions (n = 7,499 in 2020 vs. n = 8,362 in 2019). Conclusion: This ad hoc study did not confirm previous reports of a major reduction in the number of extremely pretermbirths during the first phase of the COVID-19 pandemic. Clinical Trial Registration: ClinicalTrial.gov, identifier: NCT04527601 (registered August 26, 2020), https://clinicaltrials.gov/ct2/show/NCT04527601

Neuroprotection par Estétrol dans un modèle murin de lésions diffuses de substance blanche du prématuré

peer reviewe

Physiopathology of cerebral palsy

Cerebral palsy describes a group of disorders of the development of movement and posture, causing activity limitation, that are attributed to nonprogressive disturbances that occurred in the developing fetal or infant brain. The vulnerability of different brain structures and types of disability associated with CP are influenced by the gestational age at which brain development is altered. Understanding the pathophysiology of CP is crucial for the development of neuroprotective strategies. In the first trimester of gestation, genetic disorders, infectious and toxic diseases explain the vast majority of lesions. In the preterm newborn, neuroinflammation and anoxo-ischemia induce activation of the microglia and a maturational blockade of oligodendrocytes disrupting the developmental program of white matter. In term infants, hypoxic-ischemic encephalopathy is the consequence of the excitotoxic cascade leading to cortical and/or basal ganglia lesions. Clinical disabilities are the consequence of these lesions modulated by cerebral plasticity process

Hypoxic ischemic encephalopathy : new insights in neuroprotection

Hypoxic-ischemic encephalopathy (HIE) is a major contributor to neonatal morbidity and mortality and is a common cause of disability with devastating impact on individuals and families. During the acute phase, HIE is initially characterized by an excitotoxic cascade with hypoxic membrane depolarization, cytotoxic edema, glutamate release and intracellular accumulation of calcium leading to necrotic cell death and production of proinflammatory cytokines through the NF-κB pathway. In a second phase, reperfusion leads to production of free radicals, activation of proteases and phospholipases, exacerbing the damage to cell membrane and DNA and mitochondrial dysfunction causing caspase mediated apoptotic cell death. In a third phase, growth factors and inflammatory cytokines produced during the early phase of HIE attempt to repair damage induced by hypoxia–ischemia. Although the utility of therapeutic hypothermia induced in the 6 hours following HIE in the reduction of death or major neurodevelopmental disability is now well established in the neonate with moderate or severe encephalopathy, almost half of these children still die or have abnormal outcomes [1]. Protocols attempting to optimize cooling with deeper hypothermia (33.5°C vs 32.0°C) and/or longer duration (72h vs 120h), as well protocols studying neuroprotective effect of late hypothermia (6-24h) or hypothermia for 33-35 week GA preterm babies are currently performed. Furthermore, experimental data suggest that hypothermia extends the duration of the therapeutic window [2] and that certain drugs given during this time may improve neuroprotection either additively or synergistically. Xenon is a noble gas with anaesthetic and neuroprotective properties. It inhibits NMDA receptor, promotes cell survival and induces the production of erythropoietin and vascular endothelial growth factor through the hypoxia inducible factor 1 alpha (HIF-1α) pathway. Data from experimental piglet models of hypoxia-ischemia (HI) demonstrate a synergy when Xenon is administered in combination with mild therapeutic hypothermia [3]. In the human newborn, a phase-1 trial recently established that breathing 50% Xenon for up to 18 hours with 72 hours of cooling was feasible, with no adverse effects seen with 18 months’ follow-up [4]. A monocentric phase-3 trial is currently under process in England. Melatonin is a remarkable natural antioxidant but also exhibits antiapoptotic and anti-inflammatory properties in vitro. In animal models, melatonin administration prior or after the onset of HI significantly reduced infarct volume demonstrating both prophylactic and therapeutic effect [5-6]. When combined with hypothermia, melatonin enhances neuroprotection by reduction of the H–I-induced increase in clinically relevant biomarkers in the deep grey matter of newborn piglets [7]. Clinical studies confirmed its safety profile and its ability to reduce biomarkers level of HI in the human newborn [8]. Recently, a randomized controlled trial showed that the combination of melatonin and hypothermia administered to infants with moderate-to-severe H–I brain injury was efficacious in reducing oxidative stress, neonatal seizures and MRI brain lesions as well as in improving neurological outcomes at 6 months of age [9]. Erythropoietin (EPO) and its receptor are expressed in the developing central nervous system and are required for normal brain development. EPO is up-regulated in umbilical cord blood from babies who have suffered HI, which may be an endogenous repair mechanism. In vitro and in vivo neuroprotection induced by EPO is achieved by several mechanisms such as direct neurotrophic effect, direct antioxidant effects, decreased inflammation or regulation between pro-apoptotic and anti-apoptotic factors. Safety profile of EPO administration during hypothermia for newborns with HIE has been established in Phase I trials [10]. In a randomized prospective pase-2 trial, repeated low-dose rEPO reduced the risk of disability for infants with moderate but not severe HIE at 18 months, without apparent side effects [11]. A double-blind randomized controlled phase-3 trial is currently performed in France. Allopurinol is a xantine-oxidase inhibitor. In high concentrations it also scavenges hydroxyl radicals and prevents free radical formation. Allopurinol provides neuroprotection in rat and piglets models of HIE. In the human, a systematic review and meta-analysis of three studies on 114 newborns did not reveal statistically difference in the risk of death or a composite of death or severe neurodevelopmental disability between groups [12]. It was hypothesized that postnatal allopurinol treatment started too late to reduce reperfusion-induced free radical surge. However, in a recent study, allopurinol given to mothers during labor with fetal hypoxia did not significantly lower neuronal damage markers in cord blood even if post hoc analysis revealed a potential beneficial treatment effect in girls [13]. Magnesium sulfate (MgSO4) is a naturally occurring NMDA receptor antagonist. MgSO4 given to mothers at risk for preterm birth is associated with a reduced risk of cerebral palsy and gross motor dysfunction in their children. Its role as an adjuvant to therapeutic hypothermia in the asphyxiated term infant remains unclear. A recent review of preclinical studies using MgSO4 in HIE highlights the inconsistent impact between studies related to a lack of temperature control during and after HI, along with variability in the dose, timing of treatment [14]. A metaanalysis of five randomized controlled trials that compared magnesium to control in newborns with HIE showed a significant improvement in short term outcomes but no difference in the composite outcome of death or moderate to severe disability at 18 months [15]. Other NMDA and AMPA antagonist such as topiramate and memantine also exhibited neuroprotective properties in animal models but safety and efficacy in the human newborn with HIE still needs to be clarified [16]. N-acetyl cysteine (NAC) acts as a glutathione precursor with antioxidant, antiapoptotic, and anti-inflammatory properties. In a piglet model of HIE, NAC reduced cerebral oxidative stress, reduced cerebral lactate accumulation and improved cerebral perfusion. When combined with hypothermia in the asphyxiated rodent, NAC decreased infarct volume, improved myelin expression and functional outcomes on a synergistic pattern. NF-κB inhibitors and NO synthase inhibitors are other therapeutic options currently under investigation in in vitro and in vivo preclinical studies. Moreover, recent research performed at the University of Liege also suggests that Estetrol (E4), an estrogen synthetized exclusively by the human foetus, has neuroprotective properties in a rat model of HIE. Translation to clinical use in humans still needs to be studied [17]. Several therapies have also been suggested in order to improve mechanisms of repair and regeneration observed after the HI insult. Growth factors such as BDNF, IGF-1, EGF or bFGF can improve cell viability, stimulate the growth of new neurons or promotes oligodendroglial differentiation and myelination. Recent advances in regenerative medicine suggest that stem cell transplantation may improve repair of the damaged brain after HIE through the replacement of dead cells as well as through the release of trophic factors [18]. Animal preclinical data are promising. However many questions need to be answered with well-designed controlled trials before clinical application in daily practice. References [1] Edwards AD et al. (2010) Neurological outcomes at 18 months of age after moderate hypothermia for perinatal hypoxic ischaemic encephalopathy: synthesis and meta-analysis of trial data. BMJ. 340:c363. [2] O'Brien F et al. (2006) Delayed whole-body cooling to 33 or 35 degrees c and the development of impaired energy generation consequential to transient cerebral hypoxia-ischemia in the newborn piglet. Pediatrics 117:1549–59. [3] Chakkarapani, E. et al. (2010) Xenon enhances hypothermic neuroprotection in asphyxiated newborn pigs. Ann. Neurol. 68, 330–341 [4] Dingley, J. et al. (2014) Xenon ventilation during therapeutic hypothermia in neonatal encephalopathy: a feasibility study. Pediatrics 133, 809–818 [5] Carloni, S. et al. (2008) Melatonin protects from the long-term consequences of a neonatal hypoxic–ischemic brain injury in rats. J. Pineal. Res. 44, 157–164 [6] Hutton, L.C. et al. (2009) Neuroprotective properties of melatonin in a model of birth asphyxia in the spiny mouse (Acomyscahirinus). Dev. Neurosci. 31, 437–451 [7] Robertson, N.J. et al. (2013) Melatonin augments hypothermic neuroprotection in a perinatal asphyxia model. Brain 136, 90–105 [8] Fulia, G. et al. (2001) Increased levels of malondialdehyde and nitrite/nitrate in the blood of asphyxiated newborns: reduction by melatonin. Journal of Pineal Research; 31(4):343–349. [9] Aly, H. et al. (2015) Melatonin use for neuroprotection in perinatal asphyxia: a randomized controlled pilot study. J. Perinatol. 35, 186–191 [10] Wu, Y.W. et al. (2012) Erythropoietin for neuroprotection in neonatal encephalopathy: safety and pharmacokinetics. Pediatrics 130, 683–691 [11] Zhu, C. et al. (2009) Erythropoietin improved neurologic outcomes in newborns with hypoxic–ischemic encephalopathy. Pediatrics 124, 218–226 [12] Chaudhari, T. and McGuire, W. (2012) Allopurinol for preventing mortality and morbidity in newborn infants with hypoxic–ischaemic encephalopathy. Cochrane Database Syst. Rev. 7, Cd006817 [13] Kaandorp, J.J. et al. (2015) Maternal allopurinol administration during suspected fetal hypoxia: a novel neuroprotective intervention? A multicentre randomised placebo controlled trial. Arch. Dis. Child Fetal Neonatal Ed. 100, F216–F223 [14] Galinsky, R. et al. (2014) Magnesium is not consistently neuroprotective for perinatal hypoxia-ischemia in term-equivalent models in preclinical studies: a systematic review. Dev. Neurosci. 36, 73–82 [15] Tagin, M. et al. (2013) Magnesium for newborns with hypoxic–ischemic encephalopathy: a systematic review and meta-analysis. J. Perinatol. 33, 663–669 [16] Wu, Q et al. (2015) Neuroprotective agents for neonatal hypoxic–ischemic brain injury. Drug Discovery Today. [17] Tskitishvili, E et al. (2014). Estetrol attenuates neonatal hypoxic–ischemic brain injury. Experimental Neurology, 261, 298-307. [18] Kelen, D and Robertson, NJ. (2010) Experimental treatments for hypoxic ischaemic encephalopathy. Early Human Development 86; 369–377

Neonatal brain injury : pathophysiology and current therapeutic options

Perinatal brain injury is a major contributor to neonatal morbidity and mortality and is a common cause of disability with devastating impact on individuals and families. The mechanisms involved in the genesis of brain lesions depend of the the gestational age at which brain development is altered. In the term infant, the most common pathology implicated in brain damage is hypoxic-ischemic encephalopathy (HIE). HIE is the consequence of an excitotoxic cascade leading to cortical and/or basal ganglia lesions. Therapeutic hypothermia induced in the 6 hours following HIE reduces the risk of death or major neurodevelopmental disability in the neonate with moderate or severe encephalopathy and is the only neuroprotective treatment available in clinical practice. Research is now being focused on other promising strategies such as xenon, allopurinol, N-acetyl cystein, melatonin, anticonvulsant, erythropoietin or stem cell transplantation. In the preterm infant, diffuse white matter injury (dWMI) is the main pathological condition associated with neurological impairment. Based on experimental models, pathophysiological mechanisms of dWMI potentially include infection/inflammation, hypoxia-ischemia and oxidative stress. Experimental studies suggest a sensitizing effect of systemic inflammation that makes the perinatal brain more vulnerable to further insults. Antenatal magnesium sulfate therapy given to women at risk of preterm birth substantially reduced the risk of motor disorders in childhood but is unfortunately unable to reduce long term cognitive impairment or behavioural disorders. Antenatal steroids and caffeine therapy for apnea of prematurity are two other treatments with positive impact on neurodevelopment. Randomized controlled trials studying erythropoietin or melatonin are currently under process. Finally, research performed at the University of Liege suggests that Estetrol (E4), an estrogen synthetized exclusively by the human foetus, has neuroprotective properties in animal models of HIE as well as in inflammatory-induced dWMI