Oxidative Stress Biomarkers and Early Brain Activity in Extremely Preterm Infants: A Prospective Cohort Study.

Early brain activity, measured using amplitude-integrated EEG (aEEG), is correlated with neurodevelopmental outcome in preterm newborns. F2-isoprostanes (IPs) are early biomarkers predictive for brain damage. We aimed to investigate the relationship between perinatal IPs concentrations and quantitative aEEG measures in preterm newborns. Thirty-nine infants (gestational age (GA) 24-27 ± 6 weeks) who underwent neuromonitoring using aEEG during the first two days after birth were enrolled. The rate of spontaneous activity transients per minute (SAT rate) and inter-SAT interval (ISI) in seconds were computed. Two postnatal time-points were examined: within 12 h (day 1) and between 24 and 48 h (day 2). IPs were measured in plasma from cord blood (cb-IPs) and between 24 and 48 h (pl-IPs). Multivariable regression analyses were performed to assess the correlation between IPs and brain activity. Cb-IPs were not associated with SAT rate and ISI at day 1. Higher pl-IPs were followed by longer ISI (R = 0.68; p = 0.034) and decreased SAT rate (R = 0.58; p = 0.007) at day 2 after adjusting for GA, FiO2 and IVH. Higher pl-IPs levels are associated with decreased functional brain activity. Thus, pl-IPs may represent a useful biomarker of brain vulnerability in high-risk infants.

Metabolomic Profile of Young Adults Born Preterm.

Prematurity is a risk factor for the development of chronic adult diseases. Metabolomics can correlate the biochemical changes to a determined phenotype, obtaining real information about the state of health of a subject at that precise moment. Significative differences in the metabolomic profile of preterm newborns compared to those born at term have been already identified at birth. An observational case-control study was performed at the University Hospital of Siena. The aim was to evaluate and compare the metabolomic profiles of young adults born preterm to those born at term. Urinary samples were collected from 67 young adults (18-23 years old) born preterm (mean gestational age of 30 weeks, n = 49), and at term of pregnancy (mean gestational age of 38 weeks, n = 18). The urinary spectra of young adults born preterm was different from those born at term and resembled what was previously described at birth. The Random Forest algorithm gave the best classification (accuracy 82%) and indicated the following metabolites as responsible for the classification: citrate, CH2 creatinine, fumarate and hippurate. Urine spectra are promising tools for the early identification of neonates at risk of disease in adulthood and may provide insight into the pathogenesis and effects of fetal programming and infants' outcomes.

Personality, emotional and cognitive functions in young adults born preterm.

BACKGROUND: Survival of preterm very low birthweight infants resulted in high risk for developmental cognitive deficits, poor academic achievement, and behaviour disorders. While numerous studies evaluated the prevalence of neurodevelopmental disability in early childhood, poor literature is available for infants born very low birthweight in adulthood. MATERIALS AND METHODS: Fifty-five young adults born preterm (mean age: 18 ± 2.42 years; <33 weeks of gestational age and/or with birth weight <1500 g) were enrolled. The Verbal Intelligence Quotient (vIQ), Performance Intelligence Quotient (pIQ) and Total Intelligence Quotient (tIQ) were assessed through the Wechsler Adult Intelligence Scale - Revised (WAIS-R). Personality profiles were investigated using Rorschach test. Both WAIS-R and Rorschach scores were subsequently compared to 13 matched controls born at term. Data were analysed with the SPSS v20 for Windows statistical package. RESULTS: Young adults born preterm showed lower IQ scores than young adults born at term: tIQ 90.95 ± 22.46 versus 108.77 ± 16.14, p = 0.006; vIQ 89.85 ± 21.85 versus 107.69 ± 18.33, p = 0.009, and pIQ 92.40 ± 22.90 versus 108.31 ± 14.52, p = 0.011. No differences emerged in personality profile as most subjects showed adequate internal resources in both groups, but a trend towards anxiety and insecurity were identified in young adult born preterm. CONCLUSIONS: Young adults born preterm show psychological fragility and lower cognitive pattern than young adults born at term. Data support the need of an early psychological intervention that could help these individuals at greater risk to face a young society that is changing and that necessarily requires stronger internal resources.

Isoprostanes as Biomarker for White Matter Injury in Extremely Preterm Infants.

Background and Aim: Preterm white matter is vulnerable to lipid peroxidation-mediated injury. F2-isoprostanes (IPs), are a useful biomarker for lipid peroxidation. Aim was to assess the association between early peri-postnatal IPs, white matter injury (WMI) at term equivalent age (TEA), and neurodevelopmental outcome in preterm infants. Methods: Infants with a gestational age (GA) below 28 weeks who had an MRI at TEA were included. IPs were measured in cord blood (cb) at birth and on plasma (pl) between 24 and 48 h after birth. WMI was assessed using Woodward MRI scoring system. Multiple regression analyses were performed to assess the association between IPs with WMI and then with BSITD-III scores at 24 months corrected age (CA). Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive value of pl-IPs for the development of WMI. Results: Forty-four patients were included. cb-IPs were not correlated with WMI score at TEA, whereas higher pl-IPs and lower GA predicted higher WMI score (p = 0.037 and 0.006, respectively) after controlling for GA, FiO2 at sampling and severity of IVH. The area under the curve was 0.72 (CI 95% = 0.51-0.92). The pl-IPs levels plotted curve indicated that 31.8 pg/ml had the best predictive threshold with a sensitivity of 86% and a specificity of 60%, to discriminate newborns with any WMI from newborns without WMI. IPs were not associated with outcome at 24 months. Conclusion: Early measurement of pl-IPs may help discriminate patients showing abnormal WMI score at TEA, thus representing an early biomarker to identify newborns at risk for brain injury.

Early Prediction of Hypoxic-Ischemic Brain Injury by a New Panel of Biomarkers in a Population of Term Newborns.

This research paper is aimed at evaluating the predictive role of a default panel of oxidative stress (OS) biomarkers for the early identification of infants at high risk of HIE and their validation through the correlation with MRI findings. A multicenter prospective observational study was performed between March 2012 and April 2015 in two European tertiary NICUs. Eighty-four term infants at risk for HIE (pH < 7, BE < -13 mmol/L, and 5' Apgar < 5) were enrolled. Three were excluded for chromosomal abnormalities and one due to lack of blood samples. The final population was divided according to the severity of perinatal hypoxia into 2 groups: mild/moderate HIE and severe HIE. Advanced oxidation protein products (AOPP), non-protein-bound iron (NPBI), and F2-isoprostanes (F2-IsoPs) were measured in blood samples at P1 (4-6 hours), P2 (24-72 hours), and P3 (5 days), in both groups. MRIs were scored for the severity of brain injury, using a modified Barkovich score. The mean GA was 39.8 weeks (SD 1.4) and the mean birth weight 3538 grams (SD 660); 37 were females and 43 males. Significantly lower 5' Apgar score, pH, and BE and higher Thompson score were found in group II compared to group I at birth. Group II showed significantly higher AOPP and NPBI levels than group I (mean (SD) AOPP: 15.7 (15.5) versus 34.1 (39.2), p = 0.033; NPBI 1.1 (2.5) versus 3.9 (4.4), p = 0.013) soon after birth (P1). No differences were observed in OS biomarker levels between the two groups at P2 and P3. A regression model, including adjustment for hypothermia treatment, gender, and time after birth, showed that AOPP levels and male gender were both risk factors for higher brain damage scores (AOPP: OR 3.6, 95% CI (1.1-12.2) and gender: OR 5.6, 95% CI (1.2-25.7), resp.). Newborns with severe asphyxia showed higher OS than those with mild asphyxia at birth. AOPP are significantly associated with the severity of brain injury assessed by MRI, especially in males.

Automatic quantification of ischemic injury on diffusion-weighted MRI of neonatal hypoxic ischemic encephalopathy.

A fully automatic method for detection and quantification of ischemic lesions in diffusion-weighted MR images of neonatal hypoxic ischemic encephalopathy (HIE) is presented. Ischemic lesions are manually segmented by two independent observers in 1.5 T data from 20 subjects and an automatic algorithm using a random forest classifier is developed and trained on the annotations of observer 1. The algorithm obtains a median sensitivity and specificity of 0.72 and 0.99 respectively. F1-scores are calculated per subject for algorithm performance (median = 0.52) and observer 2 performance (median = 0.56). A paired t-test on the F1-scores shows no statistical difference between the algorithm and observer 2 performances. The method is applied to a larger dataset including 54 additional subjects scanned at both 1.5 T and 3.0 T. The algorithm findings are shown to correspond well with the injury pattern noted by clinicians in both 1.5 T and 3.0 T data and to have a strong relationship with outcome. The results of the automatic method are condensed to a single score for each subject which has significant correlation with an MR score assigned by experienced clinicians (p < 0.0001). This work represents a quantitative method of evaluating diffusion-weighted MR images in neonatal HIE and a first step in the development of an automatic system for more in-depth analysis and prognostication.

Placental histological examination and the relationship with oxidative stress in preterm infants.

BACKGROUND: Prenatal conditions of enhanced oxidative stress (OS) linked to inflammation or hypoxia have been associated with impaired fetal growth and preterm delivery. Little is known regarding biomarkers of OS in the cord blood of preterm infants and placental histological patterns. OBJECTIVES: To test the hypothesis that placental lesions indicating chorioamnionitis (CA) or vascular underperfusion (VU) are associated with increased OS in the offspring. METHODS: 120 neonates born below 29+6 weeks of gestational age (GA) were enrolled. Histological characteristics of placentas from their mothers were classified as normal (CTRL group), histological CA (HCA) and vascular underperfusion (VU). Serum concentrations of isoprostanes (IsoPs), non-protein bound iron (NPBI) and advanced oxidative protein products (AOPP), were determined in cord blood. RESULTS: IsoPs, NPBI and AOPP were significantly increased in HCA group compared to CTRL group. The multivariable regression model, adjusted for GA, maternal age, parity, maternal diabetes, maternal obesity and presence/absence of fetal growth restriction (FGR), showed a significant association between the presence of HCA and increased OS biomarkers levels in cord blood (IsoPs: p = 0.006; NPBI: p = 0.014; AOPP: p = 0.007). Placental VU lesions were significantly associated with higher umbilical IsoPs, NPBI and AOPP levels (IsoPs: p = 0.008; NPBI: p = 0.002; AOPP: p = 0.040). In the cases of placental VU lesions associations were also found between high AOPP levels and low GA (p = 0.002) and the presence of fetal growth restriction (p = 0.014). CONCLUSIONS: Placental lesions indicating inflammation or impaired perfusion are associated with higher cord blood levels of OS biomarkers explaining the fetal susceptibility to oxidative injury and the need of antioxidant protection.

Arterial spin-labelling perfusion MRI and outcome in neonates with hypoxic-ischemic encephalopathy.

PURPOSE: Hyperperfusion may be related to outcome in neonates with hypoxic-ischemic encephalopathy (HIE). The purpose of this study was to evaluate whether arterial spin labelling (ASL) perfusion is associated with outcome in neonates with HIE and to compare the predictive value of ASL MRI to known MRI predictive markers. METHODS: Twenty-eight neonates diagnosed with HIE and assessed with MR imaging (conventional MRI, diffusion-weighted MRI, MR spectroscopy [MRS], and ASL MRI) were included. Perfusion in the basal ganglia and thalami was measured. Outcome at 9 or 18 months of age was scored as either adverse (death or cerebral palsy) or favourable. RESULTS: The median (range) perfusion in the basal ganglia and thalami (BGT) was 63 (28-108) ml/100 g/min in the neonates with adverse outcome and 28 (12-51) ml/100 g/min in the infants with favourable outcome (p < 0.01). The area-under-the-curve was 0.92 for ASL MRI, 0.97 for MRI score, 0.96 for Lac/NAA and 0.92 for ADC in the BGT. The combination of Lac/NAA and ASL MRI results was the best predictor of outcome (r(2) = 0.86, p < 0.001). CONCLUSION: Higher ASL perfusion values in neonates with HIE are associated with a worse neurodevelopmental outcome. A combination of the MRS and ASL MRI information is the best predictor of outcome. KEY POINTS: • Arterial spin labelling MRI can predict outcome in neonates with hypoxic-ischemic encephalopathy • Basal ganglia and thalami perfusion is higher in neonates with adverse outcome • Arterial spin labelling complements known MRI parameters in the prediction of outcome • The combined information of ASL and MRS measurements is the best predictor of outcome.

The role of oxidative stress on necrotizing enterocolitis in very low birth weight infants.

Necrotizing enterocolitis (NEC) is a devastating and common disease of very low birth weight (VLBW) infants with a mortality rate of 10% to 50% and a significant cause of morbidity in survivors. The incidence of NEC has increased from 5% to 7% in the last decades and this rate is likely to rise because of the increased survival of infants born at 24 weeks gestation, which are at high risk of developing NEC. NEC etiology is multifactorial: ischemia, infections, cytokines, enteral feeding and reactive oxygen species or free radicals (FRs) may contribute to the disruption of the immature gut barrier. In particular, ischemia, hypoxia-reperfusion, infection and inflammation are mechanisms capable of producing high levels of FRs, perturbing the normal redox balance and shifting cells to a state of oxidative stress (OS). Despite advances in neonatal medicine, the early diagnosis of NEC remains a major challenge. Early clinical signs are non specific and the laboratory findings are not fully reliable. Therefore, its delayed occurrence after birth, its rapid onset, the highly fulminant nature, and its severe morbidity, as well as the possibility of progression to death, strongly require the identification of new prospective biomarkers specific for high NEC risk. There is evidences that OS biomarkers in cord blood allow the early identification of infants at risk for NEC and thereby can be used to develop novel therapies for this devastating disease which predominantly occurs in premature infants.

Is newborn melatonin production influenced by magnetic fields produced by incubators?

BACKGROUND: During permanence in most incubators, newborns are very close to the electric engine, which represents a source of electromagnetic fields (EMF). Previous studies demonstrated a decrease in melatonin production in adults and animals exposed to EMF. AIMS: To assess melatonin production in a group of newborns exposed to EMF, and to evaluate whether removing the babies from the source of MF can affect melatonin production. STUDY DESIGN AND SUBJECTS: We have recruited 28 babies (study group), who had spent at least 48 h in incubator where we had previously assessed the presence of significant EMF. We have measured their mean 6-hydroxy-melatonin-sulfate (6OHMS) urine excretion at the end of their permanence in the incubators, and compared it with their mean 6OHMS excretion after having been put in cribs, where EMF are below the detectable limit (<0.1mG). We have also measured urine 6OHMS twice, with an interval of 48h, in a control group of 27 babies who were not exposed to EMF during both samples. RESULTS: Mean 6OHMS/cr values were respectively 5.34±4.6 and 7.68±5.1ng/mg (p=0.026) when babies were exposed to EMF in incubators, and after having been put in the crib. In the control group, mean 6OHMS/cr values in the first and in the second sample were respectively 5.91±5.41 vs 6.17±3.94ng/mg (p=0.679). CONCLUSIONS: The transitory increase in melatonin production soon after removing newborns from incubators demonstrates a possible influence of EMF on melatonin production in newborns. Further studies are needed to confirm these data.

Nitric oxide in neonatal hypoxemic respiratory failure.

Nitric oxide (NO) is a cellular signaling molecule and a powerful vasodilator. NO modulates basal pulmonary vascular tone and it is important to reduce blood pressure and to treat hypoxemic respiratory failure, such as persistent pulmonary hypertension (PPHN) in newborns. PPHN is defined as a failure of normal pulmonary vascular adaptation at or soon after birth, resulting in a persisting high pulmonary vascular resistance. iNO therapy decreases the need of extracorporeal membrane oxygenation (ECMO) although it did not reduce mortality of these patients. Severe meconial aspiration syndrome is associated with PPHN, resulting in severe hypoxemia; iNO administration combined with HFV results in ameliorate oxygenation. The cause of hypoxemic respiratory failure in patients with congenital diaphragmatic hernia (CDH) is complex. CDH patients experienced oxygenation improvement after iNO therapy, but they can be often considered iNO poor responders. In some cases iNO therapy can reduce the need of ECMO in presurgical stabilization. The pathophysiology of respiratory failure and the potential risks differ substantially in preterm infants. Pulmonary hypertension can complicate respiratory failure in preterm babies. Current evidence does not support use of iNO in early routine, early rescue or layer rescue regimens in the care of preterm infants.

May oxidative stress biomarkers in cord blood predict the occurrence of necrotizing enterocolitis in preterm infants?

INTRODUCTION: Oxidative stress (OS) is strongly involved in the pathogenesis of many preterm newborn diseases; this is due to the low efficiency of neonatal antioxidant systems unable to counteract the harmful effects of free radicals (FRs). Hypoxic-ischemic events and inflammation, involved in necrotizing enterocolitis (NEC) pathogenesis, are responsible of the overproduction of FRs, generating OS. AIM: To test the hypotesis that OS markers levels in cord blood may early identify the newborns at high risk to develop NEC. MATERIALS AND METHODS: 332 preterm newborns of gestational age (GA) between 24 and 33 week and birth weight (BW) between 460 and 2540 g were consecutively recruited in three european neonatal intensive care units. Markers of potential OS risk: non-protein bound iron (NPBI), and markers of FRs damage: advanced oxidation protein products (AOPP) and total hydroperoxides (TH), were measured in the cord blood. Associations between NEC and OS markers were checked through inferential analysis. RESULTS: Out of 332 preterm babies, 29 developed NEC. Babies with NEC had a BW and a GA significantly lower than healthy babies. AOPP, TH and NPBI cord blood levels were significantly higher in babies with NEC than in babies without (respectively mean AOPP = 28.05 ± 21 vs 15.80 ± 7.14; p < 0.05; TH = 154.48 ± 84.67 vs 107.40 ± 61.01; p < 0.05; NPBI = 2.21 ± 3.98 vs 0.95 ± 1.59; p < 0.05). CONCLUSIONS: The determination of OS biomarkers in cord blood can be useful in identifying babies at high risk for NEC and in devising new strategies to ameliorate perinatal outcome.

Whole body hypothermia and oxidative stress in babies with hypoxic-ischemic brain injury.

According to increasing evidence, hypothermia can significantly improve outcomes in term neonates manifesting asphyxic insult and hypoxic-ischemic encephalopathy. Oxidative stress plays a key role in hypoxic-ischemic and inflammatory brain injuries. We investigated the impact of hypothermia on oxidative stress in babies with hypoxic-ischemic encephalopathy. Term infants were randomly selected for treatment with moderate whole body hypothermia or standard care on normothermia, after perinatal asphyxia. Total hydroperoxides as biochemical markers of oxidative stress, and C-reactive protein as a marker of inflammation, were assayed in blood samples drown at 6, 12, 24, 48, and 72 postnatal hours. In both hypothermic and normothermic groups, total hydroperoxides and C-reactive protein exhibited a continuous increase in the first days after birth. Nevertheless, a tendency was evident for slower and smaller elevations of total hydroperoxides and C-reactive protein in hypothermic compared with normothermic infants. A significant correlation was observed between total hydroperoxides and C-reactive protein in all patients, indicating an association between inflammation and oxidative stress during asphyxia. The slower increase and lower peaks of total hydroperoxides in the hypothermic group support the hypothesis that postasphyxic oxidative stress may be reduced by hypothermia.

Oxidative stress and antioxidant strategies in newborns.

Oxidative stress (OS) is defined as an unbalance between prooxidant and antioxidant factors that can lead to cellular and tissue damage.The newborn, especially if preterm, is highly prone to OS and to the toxic effect of free radicals (FR). At birth, the newborn is exposed to a relatively hyperoxic environment caused by an increased oxygen bioavailability with greatly enhanced generation of FR. Additional sources (inflammation, hypoxia, ischemia, glutamate, and free iron release) occur magnifying OS. In the preterm baby, the perinatal transition is accompanied by the immaturity of the antioxidant systems and the reduced ability to induce efficient homeostatic mechanisms designed to control overproduction of cell-damaging FR. Improved understanding of the pathophysiological mechanism involved in perinatal brain lesions helps to identify potential targets for neuroprotective interventions, and the knowledge of these mechanisms has enabled scientists to develop new therapeutic strategies that have confirmed their neuroprotective effects in animal studies. Considering the growing role of OS in preterm newborn morbidity in respect to the higher risk of FR damage in these babies, a strict control of oxygen administration, lutein, melatonin, and hypothermia show great promise as potential neuroprotectants. This review provides an overview of the pathogenesis of free radical-mediated diseases of the newborn and the antioxidant strategies for now tested to reduce the OS and its damaging effects.

Early identification of the risk for free radical-related diseases in preterm newborns.

BACKGROUND: Despite recent advances in preterm newborns healthcare, perinatal pathologies and disabilities are increasing. Oxidative stress (OS) is determinant for the onset of an unbalance between free radicals (FRs) production and antioxidant systems which plays a key role in pathogenesis of pathologies such as retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), grouped as 'free radical-related diseases' (FRD). AIM: This study tests the hypothesis that OS markers levels in cord blood may predict the onset of FRD pathologies. PATIENTS AND METHODS: 168 preterm newborns of GA: 24-32weeks (28.09+/-1.99); and BW: 470-2480 gr (1358.11+/-454.09) were consecutively recruited. Markers of potential OS risk (non-protein bound iron, NPBI; basal superoxide anion, BSA; under stimulation superoxide anion, USSA) and markers of OS-related damage (total hydroperoxides, TH; advanced oxidation protein products, AOPP) were assessed in cord blood. Associations between FRD onset and OS markers were checked through inferential analysis (univariate logistic regression). RESULTS: The development of FRD was significantly associated to high cord blood levels of TH, AOPP and NPBI (respectively p=0.000, OR=1.025, 95%CI=1.013-1.038; p=0.014, OR=1.092, 95%CI=1.018-1.172; p=0.007, OR=1.26995%CI=1.066-1.511). CONCLUSIONS: Elevated levels of TH, AOPP and, above all, NPBI, in cord blood are associated with increased risk for FRD. OS markers allow the early identification of infants at risk for FRD because of perinatal oxidant exposure. This can be useful in devising strategies to prevent or ameliorate perinatal outcome.