Systemic inflammation on postnatal days 21 and 28 and indicators of brain dysfunction 2years later among children born before the 28th week of gestation

Correlating maternal and cord-blood inflammatory markers and BDNF with human fetal brain activity recorded by magnetoencephalography: An exploratory study

Background

During gestation, the brain development of the fetus is affected by many biological markers, where inflammatory processes and neurotrophic factors have been of particular interest in the past decade.

Aim

This exploratory study is the first attempt to explore the relationships between biomarker levels in maternal and cord-blood samples and human fetal brain activity measured with non-invasive fetal magnetoencephalography (fMEG).

Method

Twenty-three women were enrolled in this study for collection of maternal serum and fMEG tracings immediately prior to their scheduled cesarean delivery. Twelve of these women had a preexisting diabetic condition. At the time of delivery, umbilical cord blood was also collected. Biomarker levels from both maternal and cord blood were measured and subsequently analyzed for correlations with fetal brain activity in four frequency bands extracted from fMEG power spectral densities.

Results

Relative power in the delta, alpha, and beta frequency bands exhibited moderate-sized correlations with maternal BDNF and cord-blood CRP levels before and after adjusting for confounding diabetic status. These correlations were negative for the delta band, and positive for the alpha and beta bands. Maternal CRP and cord-blood BDNF and IL-6 exhibited negligible correlations with relative power in all four bands. Diabetes did not appear to be a strong confounding factor affecting the studied biomarkers.

Conclusions

Maternal BDNF levels and cord-blood CRP levels appear to have a direct correlation to fetal brain activity. Our findings indicate the potential use of these biomarkers in conjunction with fetal brain electrophysiology to track fetal neurodevelopment.

The longitudinal growth trajectory of children with congenital hypothyroidism during the first 3 years of life

Congenital hypothyroidism (CH) is detected through a newborn screening program in Iran, enabling early detection and prompt treatment. This study addresses the longitudinal growth trajectory of Iranian children with CH and explores associated factors during the first 3 years of life. Data from 1474 children with CH in Isfahan, Iran (2002-2022), were analyzed. Weight, height, and head circumference were measured, and z-scores for age were calculated. Group-based trajectory modeling was applied to distinct growth trajectories. Factors influencing growth patterns, including gender, treatment initiation age, delivery method, parental consanguinity, history of familial hypothyroidism, and thyroid-stimulating hormone (TSH) levels at 3-7 days, were investigated. Thirty-seven percent of children diagnosed with CH faced a delay in weight, while 36.6% experienced stunted height, and 25.7% showed a retardation in head circumference growth. The initiation of treatment, parental consanguinity, and family history of hypothyroidism varied among these groups. Children exhibiting an optimal growth pattern in the initial 3 years of life demonstrated lower average TSH levels.

CONCLUSION

This research emphasizes the complexity of managing CH and stresses the importance of tailoring interventions based on individualized characteristics and the ongoing growth patterns of the children. Future research is required to understand the intricate relationships between growth patterns and various determinants and optimize the growth and developmental outcomes of children with CH.

WHAT IS KNOWN

• Iran has a higher prevalence of congenital hypothyroidism (CH) with a nationwide screening program. • There are concerns about delayed growth in CH children, but limited research on long-term patterns and contributing factors.

WHAT IS NEW

• Distinct patterns in weight, height, and head circumference among children with CH were identified. • Factors such as consanguinity, parental hypothyroidism, and TSH levels impact growth outcomes. • CH management is complicated, and there is a need for individualized interventions.

Perinatal inflammation, fetal growth restriction, and long-term neurodevelopmental impairment in Bangladesh

BACKGROUND

There are limited data on the impact of perinatal inflammation on child neurodevelopment in low-middle income countries and among growth-restricted infants.

METHODS

Population-based, prospective birth cohort study of 288 infants from July 2016-March 2017 in Sylhet, Bangladesh. Umbilical cord blood was analyzed for interleukin(IL)-1α, IL-1β, IL-6, IL-8, and C-reactive protein(CRP). Child neurodevelopment was assessed at 24 months with Bayley-III Scales of Infant Development. We determined associations between cord blood inflammation and neurodevelopmental outcomes, controlling for potential confounders.

RESULTS

248/288 (86%) live born infants were followed until 24 months, among whom 8.9% were preterm and 45.0% small-for-gestational-age(SGA) at birth. Among all infants, elevated concentrations (>75%) of CRP and IL-6 at birth were associated with increased odds of fine motor delay at 24 months; elevated CRP was also associated with lower receptive communication z-scores. Among SGA infants, elevated IL-1α was associated with cognitive delay, IL-8 with language delay, CRP with lower receptive communication z-scores, and IL-1β with lower expressive communication and motor z-scores.

CONCLUSIONS

In rural Bangladesh, perinatal inflammation was associated with impaired neurodevelopment at 24 months. The associations were strongest among SGA infants and noted across several biomarkers and domains, supporting the neurobiological role of inflammation in adverse fetal development, particularly in the setting of fetal growth restriction.

IMPACT

Cord blood inflammation was associated with fine motor and language delays at 24 months of age in a community-based cohort in rural Bangladesh. 23.4 million infants are born small-for-gestational-age (SGA) globally each year. Among SGA infants, the associations between cord blood inflammation and adverse outcomes were strong and consistent across several biomarkers and neurodevelopmental domains (cognitive, motor, language), supporting the neurobiological impact of inflammation prominent in growth-restricted infants. Prenatal interventions to prevent intrauterine growth restriction are needed in low- and middle-income countries and may also result in long-term benefits on child development.

Maternal COVID-19 infection and the fetus: Immunological and neurological perspectives

Immunoneuropsychiatry is an emerging field about the interaction between the immune and nervous systems. Infection and infection-related inflammation (in addition to genetics and environmental factors) can act as the etiopathogenesis of neuropsychiatric disorders (NPDs). Exposure to COVID-19 in utero may be a risk factor for developing NPDs in offspring in the future. Maternal immune activation (MIA) and subsequent inflammation can affect fetal brain development. Inflammatory mediators, cytokines, and autoantibodies can pass through the placenta and the compromised blood-brain barrier after MIA, leading to neuroinflammation. Neuroinflammation also affects multiple neurobiological pathways; for example, it decreases the production of the neurotransmitter serotonin. Fetal sex may affect the mother's immune response. Pregnant women with male fetuses have been reported to have decreased maternal and placental humoral responses. This suggests that in pregnancies with a male fetus, fewer antibodies may be transferred to the fetus and contribute to males' increased susceptibility/vulnerability to infectious diseases compared to female infants. Here, we want to discuss maternal COVID-19 infection and its consequences for the fetus, particularly the neurological outcomes and the interaction between fetal sex and possible changes in maternal immune responses.

Early laparoscopic-assisted surgery is associated with decreased post-operative inflammation and intestinal strictures in infants with necrotizing enterocolitis

INTRODUCTION

In 2015, a protocol including early laparoscopy-assisted surgery in the treatment of necrotizing enterocolitis (NEC) was implemented at our institution. Carbon dioxide insufflation during laparoscopy may have an anti-inflammatory effect. We aimed to compare post-operative outcome after early laparoscopy-assisted surgery and classical laparotomy for NEC.

MATERIAL AND METHODS

Charts of premature infants undergoing surgery for NEC (2012-2021) were reviewed. Cases operated by early laparoscopy-assisted surgery (2015-2021) were compared to infants operated for NEC between 2012 and 2015 (laparotomy-NEC). Outcomes were post-operative CRP, need for reintervention, mortality, and the occurrence of post-NEC intestinal strictures. CRP was measured on the day of surgery (POD-0), 2 days (POD-2), and 7 days after surgery (POD-7). Data were compared using contingency tables for categorical variables and Student t-test or Mann-Whitney test for continuous variables.

RESULTS

Infants with NEC operated by early laparoscopy (n = 48) and laparotomy (n = 29) were similar in terms of perforation (60% vs 58%, p = 0.99) and POD-0 CRP (139 vs 124 mg/L, p = 0.94). Delay between first signs of NEC and surgery was shorter in the laparoscopy group (3 vs 6 days, p = 0.004). Early laparoscopy was associated with a lower CRP on POD-2 (108 vs 170, p = 0.005) and POD-7 (37 vs 68, p = 0.002), as well as a lower rate of post-operative intestinal stricture (34% vs 61%, p = 0.04).

CONCLUSIONS

In addition to being safe and feasible in premature infants, early laparoscopic-assisted surgery was associated with decreased NEC-related post-operative inflammation and strictures. A prospective, randomized study is needed in order to evaluate short and long-term effects of laparoscopy in infants with NEC.

LEVEL OF EVIDENCE

Level III.

Associations between the human immune system and gut microbiome with neurodevelopment in the first 5 years of life: A systematic scoping review

The aim of this review was to map the literature assessing associations between maternal or infant immune or gut microbiome biomarkers and child neurodevelopmental outcomes within the first 5 years of life. We conducted a PRISMA-ScR compliant review of peer-reviewed, English-language journal articles. Studies reporting gut microbiome or immune system biomarkers and child neurodevelopmental outcomes prior to 5 years were eligible. Sixty-nine of 23,495 retrieved studies were included. Of these, 18 reported on the maternal immune system, 40 on the infant immune system, and 13 on the infant gut microbiome. No studies examined the maternal microbiome, and only one study examined biomarkers from both the immune system and the gut microbiome. Additionally, only one study included both maternal and infant biomarkers. Neurodevelopmental outcomes were assessed from 6 days to 5 years. Associations between biomarkers and neurodevelopmental outcomes were largely nonsignificant and small in effect size. While the immune system and gut microbiome are thought to have interactive impacts on the developing brain, there remains a paucity of published studies that report biomarkers from both systems and associations with child development outcomes. Heterogeneity of research designs and methodologies may also contribute to inconsistent findings. Future studies should integrate data across biological systems to generate novel insights into the biological underpinnings of early development.

CpG methylation patterns in placenta and neonatal blood are differentially associated with neonatal inflammation

BACKGROUND

Infants born extremely premature are at increased risk for health complications later in life for which neonatal inflammation may be a contributing biological driver. Placental CpG methylation provides mechanistic information regarding the relationship between prenatal epigenetic programming, prematurity, neonatal inflammation, and later-in-life health.

METHODS

We contrasted CpG methylation in the placenta and neonatal blood spots in relation to neonatal inflammation in the Extremely Low Gestational Age Newborn (ELGAN) cohort. Neonatal inflammation status was based on the expression of six inflammation-related proteins, assessed as (1) day-one inflammation (DOI) or (2) intermittent or sustained systemic inflammation (ISSI, inflammation on ≥2 days in the first 2 postnatal weeks). Epigenome-wide CpG methylation was assessed in 354 placental samples and 318 neonatal blood samples.

RESULTS

Placental CpG methylation displayed the strongest association with ISSI (48 CpG sites) but was not associated with DOI. This was in contrast to CpG methylation in blood spots, which was associated with DOI (111 CpG sites) and not with ISSI (one CpG site).

CONCLUSIONS

Placental CpG methylation was strongly associated with ISSI, a measure of inflammation previously linked to later-in-life cognitive impairment, while day-one neonatal blood methylation was associated with DOI.

IMPACT

Neonatal inflammation increases the risk of adverse later-life outcomes, especially in infants born extremely preterm. CpG methylation in the placenta and neonatal blood spots were evaluated in relation to neonatal inflammation assessed via circulating proteins as either (i) day-one inflammation (DOI) or (ii) intermittent or sustained systemic inflammation (ISSI, inflammation on ≥2 days in the first 2 weeks). Tissue specificity was observed in epigenetic-inflammatory relationships: placental CpG methylation was associated with ISSI, neonatal blood CpG methylation was associated with DOI. Supporting the placental origins of disease framework, placental epigenetic patterns are associated with a propensity for ISSI in neonates.

Associations between systemic health and retinal nerve fibre layer thickness in preterm infants at 36 weeks postmenstrual age

BACKGROUND/AIMS

Neonatal insults from systemic diseases have been implicated in the pathway of impaired neurodevelopment in preterm infants. We aimed to investigate the associations between systemic health factors and retinal nerve fibre layer (RNFL) thickness in preterm infants.

METHODS

We prospectively enrolled infants and imaged both eyes at 36±1 weeks postmenstrual age (PMA) using a hand-held optical coherence tomography system at the bedside in the Duke intensive care nurseries. We evaluated associations between RNFL thickness and 29 systemic health factors using univariable and multivariable regression models.

RESULTS

83 infants with RNFL thickness measures were included in this study. Based on the multivariable model, RNFL thickness was positively associated with infant weight at imaging and was negatively associated with sepsis/necrotising enterocolitis (NEC). RNFL thickness was 10.4 µm (95% CI -15.9 to -4.9) lower in infants with than without sepsis/NEC in the univariable analysis (p<0.001). This difference remained statistically significant after adjustment for confounding variables in various combinations (birth weight, birthweight percentile, gestational age, infant weight at imaging and growth velocity). A 250 g increase in infant weight at imaging was associated with a 3.1 µm (95% CI 2.1 to 4.2) increase in RNFL thickness in the univariable analysis (p<0.001).

CONCLUSIONS

Low infant weight and sepsis/NEC were independently associated with thinner RNFL in preterm infants at 36 weeks PMA. To our knowledge, this study is the first to suggest that sepsis/NEC may affect retinal neurodevelopment. Future longitudinal studies are needed to investigate this relationship further.

Retinopathy of prematurity and neurodevelopmental outcomes in preterm infants: A systematic review and meta-analysis

Background

Retinopathy of prematurity (ROP) and abnormal brain development share similar risk factors and mechanisms. There has been contrasting evidence on the association of ROP with adverse neurodevelopmental outcomes.

Objective

We analysed the association between ROP at levels of severity and treatment with all neurodevelopmental outcomes until adolescence.

Data source

We followed PRISMA guidelines and searched Medline and Embase between 1 August 1990 and 31 March 2022.

Study selection and participants

Randomised or quasi-randomised clinical trials and observational studies on preterm infants (<37 weeks) with ROP [type 1 or severe ROP, type 2 or milder ROP, laser or anti-vascular endothelial growth factor (VEGF) treated] were included.

Data extraction and synthesis

We included studies on ROP and any neurocognitive or neuropsychiatric outcomes.

Outcomes

The primary outcomes were as follows: cognitive composite scores evaluated between the ages of 18 and 48 months by the Bayley Scales of Infant and Toddler Development (BSID) or equivalent; neurodevelopmental impairment (NDI; moderate to severe NDI or severe NDI), cerebral palsy, cognitive impairment; and neuropsychiatric or behavioural problems. The secondary outcomes were as follows: motor and language composite scores evaluated between the ages of 18 and 48 months by BSID or equivalent; motor/language impairment; and moderate/severe NDI as defined by the authors.

Results

In preterm infants, "any ROP" was associated with an increased risk of cognitive impairment or intellectual disability [n = 83,506; odds ratio (OR): 2.56; 95% CI: 1.40-4.69; p = 0.002], cerebral palsy (n = 3,706; OR: 2.26; 95% CI: 1.72-2.96; p < 0.001), behavioural problems (n = 81,439; OR: 2.45; 95% CI: 1.03-5.83; p = 0.04), or NDI as defined by authors (n = 1,930; OR: 3.83; 95% CI: 1.61-9.12; p = 0.002). Type 1 or severe ROP increased the risk of cerebral palsy (OR: 2.19; 95% CI: 1.23-3.88; p = 0.07), cognitive impairment or intellectual disability (n = 5,167; OR: 3.56; 95% CI: 2.6-4.86; p < 0.001), and behavioural problems (n = 5,500; OR: 2.76; 95% CI: 2.11-3.60; p < 0.001) more than type 2 ROP at 18-24 months. Infants treated with anti-VEGF had higher odds of moderate cognitive impairment than the laser surgery group if adjusted data (gestational age, sex severe intraventricular haemorrhage, bronchopulmonary dysplasia, sepsis, surgical necrotising enterocolitis, and maternal education) were analysed [adjusted OR (aOR): 1.93; 95% CI: 1.23-3.03; p = 0.04], but not for cerebral palsy (aOR: 1.29; 95% CI: 0.65-2.56; p = 0.45). All outcomes were adjudged with a "very low" certainty of evidence.

Conclusion and relevance

Infants with "any ROP" had higher risks of cognitive impairment or intellectual disability, cerebral palsy, and behavioural problems. Anti-VEGF treatment increased the risk of moderate cognitive impairment. These results support the association of ROP and anti-VEGF treatment with adverse neurodevelopmental outcomes.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022326009.

A unique cerebellar pattern of microglia activation in a mouse model of encephalopathy of prematurity

Preterm infants often show pathologies of the cerebellum, which are associated with impaired motor performance, lower IQ and poor language skills at school ages. Using a mouse model of inflammation-induced encephalopathy of prematurity driven by systemic administration of pro-inflammatory IL-1β, we sought to uncover causes of cerebellar damage. In this model, IL-1β is administered between postnatal day (P) 1 to day 5, a timing equivalent to the last trimester for brain development in humans. Structural MRI analysis revealed that systemic IL-1β treatment induced specific reductions in gray and white matter volumes of the mouse cerebellar lobules I and II (5% false discovery rate [FDR]) from P15 onwards. Preceding these MRI-detectable cerebellar volume changes, we observed damage to oligodendroglia, with reduced proliferation of OLIG2+ cells at P10 and reduced levels of the myelin proteins myelin basic protein (MBP) and myelin-associated glycoprotein (MAG) at P10 and P15. Increased density of IBA1+ cerebellar microglia were observed both at P5 and P45, with evidence for increased microglial proliferation at P5 and P10. Comparison of the transcriptome of microglia isolated from P5 cerebellums and cerebrums revealed significant enrichment of pro-inflammatory markers in microglia from both regions, but cerebellar microglia displayed a unique type I interferon signaling dysregulation. Collectively, these data suggest that perinatal inflammation driven by systemic IL-1β leads to specific cerebellar volume deficits, which likely reflect oligodendrocyte pathology downstream of microglial activation. Further studies are now required to confirm the potential of protective strategies aimed at preventing sustained type I interferon signaling driven by cerebellar microglia as an important therapeutic target.

Systemic inflammatory regulators and 7 major psychiatric disorders: A two-sample Mendelian randomization study

Systemic inflammation has been thought to play a considerable part in psychiatric disorders. However, the causal relationships between systemic inflammation and psychiatric disorders and the directions of the causal effects remain elusive and need further investigation. By leveraging the summary statistics of genome-wide association studies, the standard inverse variance weighted method was applied to assess the causal associations among 41 systemic inflammatory regulators and 7 major psychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD), anorexia nervosa (AN), autism spectrum disorder (ASD), bipolar disorder (BIP), major depression disorder (MDD), obsessive-compulsive disorder (OCD), and schizophrenia (SCZ), within a two-sample bidirectional Mendelian randomization analysis. Additionally, the weighted median test and the Mendelian randomization pleiotropy residual sum and outlier test were conducted for sensitivity analyses. The results suggested a total of 15 unique systemic inflammatory regulators might be causally associated with disease risk, including 2 for ADHD, 4 for AN, 2 for ASD, 2 for MDD, 2 for OCD, and 5 for SCZ. Among them, the genetically predicted concentration of basic fibroblast growth factor was significantly related to AN at the Bonferroni-corrected threshold (Odds ratio = 0.403, 95% confidence interval = (0.261, 0.622), P = 4.03 × 10^-5). Furthermore, the concentrations of 9 systemic inflammatory regulators might be influenced by neuropsychiatric disorders, including 2 by ADHD, 2 by BIP, 3 by MDD, and 2 by SCZ, and the causal effects of ASD, AN, and OCD need to be further assessed when more significant genetic variants are identified in the future. Overall, this study provides additional insights into the relationships between systemic inflammation and psychiatric disorders and may provide new clues regarding the aetiology, diagnosis and treatment of psychiatric disorders.

Deleterious effects of nervous system in the offspring following maternal SARS-CoV-2 infection during the COVID-19 pandemic

During the Coronavirus disease 2019 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is universally susceptible to all types of populations. In addition to the elderly and children becoming the groups of great concern, pregnant women carrying new lives need to be even more alert to SARS-CoV-2 infection. Studies have shown that pregnant women infected with SARS-CoV-2 can lead to brain damage and post-birth psychiatric disorders in offspring. It has been widely recognized that SARS-CoV-2 can affect the development of the fetal nervous system directly or indirectly. Pregnant women are recommended to mitigate the effects of COVID-19 on the fetus through vaccination, nutritional supplements, and psychological support. This review summarizes the possible mechanisms of the nervous system effects of SARS-CoV-2 infection on their offspring during the pregnancy and analyzes the available prophylactic and treatment strategies to improve the prognosis of fetal-related neuropsychiatric diseases after birth.

Intraoperative cerebral oxygen saturation and neurological outcomes following surgical management of necrotizing enterocolitis: Predictive factors of neurological complications following neonatal necrotizing enterocolitis: Predictive factors of neurological complications following neonatal necrotizing enterocolitis

BACKGROUND

The goal of the present study was to investigate intraoperative factors associated with major neurological complications at 1 year following surgery for necrotizing enterocolitis.

MATERIAL AND METHODS

The study consisted of a retrospective review of medical charts of patients operated for over one calendar year in one institution. Data collected included demographic data, cardiac resuscitation at birth, Bell classification, antibiotics usage, time of day of surgery, surgical technique, surgical duration, type of ventilation, intraoperative vasoactive agents, and albumin use, nadir cerebral saturation, the decrease in cerebral saturation from baseline, the time period when cerebral saturation was at least 20% below baseline, and the mean arterial pressure at nadir cerebral saturation. Reported follow-up complications were assessed during formal neonatologist consultation and additional imaging exploration as needed. Analyses included descriptive statistics, and univariable and multivariable statistics.

RESULTS

The study included 32 patients with no prior clinical neurological complications, of which 25 had normal cerebral imaging. Severe neurological complications occurred in nine patients at 1 year: Intraventricular hemorrhage (N = 2) and Periventricular leukomalacia (N = 7). However, preoperative cerebral imaging was lacking in seven patients. Consequently, the observed neurological complications at 1 year might be present before the surgery. Multivariable analysis found the decrease in cerebral saturation ≥36% from baseline as the only factor associated with the occurrence of those complications.

CONCLUSION

Intraoperative decrease of cerebral oxygen saturation below ≥36% from baseline is associated with severe neurological complications in neonates undergoing surgery for necrotizing enterocolitis.

Association Between Newborn Thyroid-Stimulating-Hormone Concentration and Neurodevelopment and Growth: a Systematic Review

Iodine nutrition during pregnancy can affect newborn thyroid-stimulating-hormone concentration (TSH). Associations of newborn TSH with the neurodevelopment and growth of children are inconsistent. The aim of the study was to systematically review the literature on the associations between newborn TSH and childhood neurodevelopment and growth. Databases including PubMed, Scopus, CINAHL, Embase, PsycINFO, WHO, and Iodine Global Network were searched for eligible studies. Seventeen studies were included. Neurodevelopment was assessed using different tools in children aged 1-12 years of age. The associations between newborn TSH and cognitive development were negative in studies from iodine deficient populations, while a null association was found in studies from iodine sufficient populations. A null association between TSH and psychomotor development was observed regardless of iodine status of the study populations. There was no evidence of an association between newborn TSH and child anthropometry, but evidence of negative association was found between newborn TSH and birthweight. Although the associations between newborn TSH and neurodevelopment may differ based on the iodine status of populations, most of the included studies did not adjust for the key confounders and had a small sample size. Quality data-linkage studies that utilize newborn TSH data from newborn screening with adequate adjustment for potential confounders are warranted to better understand the relationship between newborn TSH and neurodevelopment and growth in children. CRD42020152878.

Placental mediated mechanisms of perinatal brain injury: Evolving inflammation and exosomes

Pregnancy is an inflammatory process that is carefully regulated by the placenta via immunomodulation and cell-to-cell communication of maternal and fetal tissues. Exosomes, types of extracellular vesicles, facilitate the intercellular communication and traffic biologically modifying cargo within the maternal-placental-fetal axis in normal and pathologic pregnancies. Chorioamnionitis is characterized by inflammation of chorioamniotic membranes that produces systemic maternal and fetal inflammatory responses of cytokine dysregulation and has been associated with brain injury and neurodevelopmental disorders. This review focuses on how pathologic placental exosomes propagate acute and chronic inflammation leading to brain injury. The evidence reviewed here highlights the need to investigate exosomes from pathologic pregnancies and those with known brain injury to identify new diagnostics, biomarkers, and potential therapeutic targets.

Systemic Inflammation in the First 2 Weeks after Birth as a Determinant of Physical Growth Outcomes in Hospitalized Infants with Extremely Low Gestational Age

OBJECTIVE

To examine associations of systemic inflammation with growth outcomes at neonatal intensive care unit discharge or transfer among infants with extremely low gestational ages.

STUDY DESIGN

We studied 850 infants at born at 23-27 weeks of gestation. We defined inflammatory protein elevation as the highest quartile of C-reactive protein (CRP), Interleukin (IL)-6, tumor necrosis factor-∝, or IL-8 on postnatal days 1, 7, and 14. We compared z-scores of weight, length, and head circumference at neonatal intensive care unit discharge or transfer between infants with vs without inflammatory protein elevation, adjusting in linear regression for birth size z-score, sex, gestational age, diet, comorbidities, medications, and length of hospitalization.

RESULTS

The mean gestational age was 25 weeks (range, 23-27 weeks) and birth weight z-score 0.14 (range, -2.73 to 3.28). Infants with a high CRP on day 7 had lower weights at discharge or transfer (-0.17 z-score; 95% CI, -0.27 to -0.06) than infants without CRP elevation, with similar results on day 14. Infants with CRP elevation on day 14 were also shorter (-0.21 length z-scores; 95% CI, -0.38 to -0.04), and had smaller head circumferences (-0.18 z-scores; 95% CI, -0.33 to -0.04) at discharge or transfer. IL-6 elevation on day 14 was associated with lower weight (-0.12; 95% CI, -0.22 to -0.02); IL-6 elevation on day 7 was associated with shorter length (-0.27; 95% CI, -0.43 to -0.12). Tumor necrosis factor-∝ and IL-8 elevation on day 14 were associated with a lower weight at discharge or transfer.

CONCLUSIONS

Postnatal systemic inflammation may contribute to impaired nutrient accretion during a critical period in development in infants with extremely low gestational ages.

Intrauterine Viral Infections: Impact of Inflammation on Fetal Neurodevelopment

Intrauterine viral infections during pregnancy by pathogens such as Zika virus, Cytomegalovirus, Rubella and Herpes Simplex virus can lead to prenatal as well as postnatal neurodevelopmental disorders. Although maternal viral infections are common during pregnancy, viruses rarely penetrate the trophoblast. When they do cross, viruses can cause adverse congenital health conditions for the fetus. In this context, maternal inflammatory responses to these neurotropic pathogens play a significant role in negatively affecting neurodevelopment. For instance, intrauterine inflammation poses an increased risk of neurodevelopmental disorders such as microcephaly, schizophrenia, autism spectrum disorder, cerebral palsy and epilepsy. Severe inflammatory responses have been linked to stillbirths, preterm births, abortions and microcephaly. In this review, we discuss the mechanistic basis of how immune system shapes the landscape of the brain and how different neurotropic viral pathogens evoke inflammatory responses. Finally, we list the consequences of neuroinflammation on fetal brain development and discuss directions for future research and intervention strategies.

Maternal Diet, Infection, and Risk of Cord Blood Inflammation in the Bangladesh Projahnmo Pregnancy Cohort

Inflammation may adversely affect early human brain development. We aimed to assess the role of maternal nutrition and infections on cord blood inflammation. In a pregnancy cohort in Sylhet, Bangladesh, we enrolled 251 consecutive pregnancies resulting in a term livebirth from July 2016-March 2017. Stillbirths, preterm births, and cases of neonatal encephalopathy were excluded. We prospectively collected data on maternal diet (food frequency questionnaire) and morbidity, and analyzed umbilical cord blood for interleukin (IL)-1α, IL-1β, IL-6, IL-8 and C-reactive protein. We determined associations between nutrition and infection exposures and cord cytokine elevation (≥75% vs. <75%) using logistic regression, adjusting for confounders. One-third of mothers were underweight (BMI < 18.5 kg/m2) at enrollment. Antenatal and intrapartum infections were observed among 4.8% and 15.9% of the sample, respectively. Low pregnancy intakes of B vitamins (B1, B2, B3, B6, B9 (folate)), fat-soluble vitamins (D, E), iron, zinc, and linoleic acid (lowest vs. middle tertile) were associated with higher risk of inflammation, particularly IL-8. There was a non-significant trend of increased risk of IL-8 and IL-6 elevation with history of ante-and intrapartum infections, respectively. In Bangladesh, improving micronutrient intake and preventing pregnancy infections are targets to reduce fetal systemic inflammation and associated adverse neurodevelopmental outcomes.

Sustained peripheral immune hyper-reactivity (SPIHR): an enduring biomarker of altered inflammatory responses in adult rats after perinatal brain injury

Background

Chorioamnionitis (CHORIO) is a principal risk factor for preterm birth and is the most common pathological abnormality found in the placentae of preterm infants. CHORIO has a multitude of effects on the maternal–placental–fetal axis including profound inflammation. Cumulatively, these changes trigger injury in the developing immune and central nervous systems, thereby increasing susceptibility to chronic sequelae later in life. Despite this and reports of neural–immune changes in children with cerebral palsy, the extent and chronicity of the peripheral immune and neuroinflammatory changes secondary to CHORIO has not been fully characterized.

Methods

We examined the persistence and time course of peripheral immune hyper-reactivity in an established and translational model of perinatal brain injury (PBI) secondary to CHORIO. Pregnant Sprague–Dawley rats underwent laparotomy on embryonic day 18 (E18, preterm equivalent). Uterine arteries were occluded for 60 min, followed by intra-amniotic injection of lipopolysaccharide (LPS). Serum and peripheral blood mononuclear cells (PBMCs) were collected at young adult (postnatal day P60) and middle-aged equivalents (P120). Serum and PBMCs secretome chemokines and cytokines were assayed using multiplex electrochemiluminescent immunoassay. Multiparameter flow cytometry was performed to interrogate immune cell populations.

Results

Serum levels of interleukin-1β (IL-1β), IL-5, IL-6, C–X–C Motif Chemokine Ligand 1 (CXCL1), tumor necrosis factor-α (TNF-α), and C–C motif chemokine ligand 2/monocyte chemoattractant protein-1 (CCL2/MCP-1) were significantly higher in CHORIO animals compared to sham controls at P60. Notably, CHORIO PBMCs were primed. Specifically, they were hyper-reactive and secreted more inflammatory mediators both at baseline and when stimulated in vitro. While serum levels of cytokines normalized by P120, PBMCs remained primed, and hyper-reactive with a robust pro-inflammatory secretome concomitant with a persistent change in multiple T cell populations in CHORIO animals.

Conclusions

The data indicate that an in utero inflammatory insult leads to neural–immune changes that persist through adulthood, thereby conferring vulnerability to brain and immune system injury throughout the lifespan. This unique molecular and cellular immune signature including sustained peripheral immune hyper-reactivity (SPIHR) and immune cell priming may be a viable biomarker of altered inflammatory responses following in utero insults and advances our understanding of the neuroinflammatory cascade that leads to perinatal brain injury and later neurodevelopmental disorders, including cerebral palsy.

Intermittent Hypoxemia in Preterm Infants: A Potential Proinflammatory Process

OBJECTIVE

A major consequence of prematurity is intermittent hypoxemia (IH). Data from both adult studies and neonatal animal models suggest that IH is proinflammatory; however, there is limited data in preterm infants. Here, we assess the relationship between IH and systemic inflammation, namely, serum C-reactive protein (CRP) in preterm infants.

STUDY DESIGN

Serum CRP was measured at 30 days of life, at the time of peak IH frequency. IH measures (e.g., per cent time in hypoxemia, frequency, duration) were calculated the week prior to CRP collection. Statistical analyses were based on Spearman's correlation.

RESULTS

A total of 26 infants were included. Median gestational age and birth weight were 27^4/7 weeks and 980 g, respectively. There were positive correlations between primary IH measures and CRP levels, especially for events longer than 1-minute duration (r range: 0.56-0.74, all p < 0.01).

CONCLUSION

We demonstrate that IH is associated with increased CRP for the first time in preterm infants. Our findings are consistent with studies from adults and neonatal animal models suggesting that IH is a proinflammatory process.

KEY POINTS

· IH events are common.. · IH is associated with elevated C-reactive protein.. · Longer IH events (>1 min) are of most significance..

Targeting Microglial Disturbances to Protect the Brain From Neurodevelopmental Disorders Associated With Prematurity

Microglial activation during critical phases of brain development can result in short- and long-term consequences for neurological and psychiatric health. Several studies in humans and rodents have shown that microglial activation, leading to a transition from the homeostatic state toward a proinflammatory phenotype, has adverse effects on the developing brain and neurodevelopmental disorders. Targeting proinflammatory microglia may be an effective strategy for protecting the brain and attenuating neurodevelopmental disorders induced by inflammation. In this review we focus on the role of inflammation and the activation of immature microglia (pre-microglia) soon after birth in prematurity-associated neurodevelopmental disorders, and the specific features of pre-microglia during development. We also highlight the relevance of immunomodulatory strategies for regulating activated microglia in a rodent model of perinatal brain injury. An original neuroprotective approach involving a nanoparticle-based therapy and targeting microglia, with the aim of improving myelination and protecting the developing brain, is also addressed.

Perinatal Nutritional and Metabolic Pathways: Early Origins of Chronic Lung Diseases

Lung development is not completed at birth, but expands beyond infancy, rendering the lung highly susceptible to injury. Exposure to various influences during a critical window of organ growth can interfere with the finely-tuned process of development and induce pathological processes with aberrant alveolarization and long-term structural and functional sequelae. This concept of developmental origins of chronic disease has been coined as perinatal programming. Some adverse perinatal factors, including prematurity along with respiratory support, are well-recognized to induce bronchopulmonary dysplasia (BPD), a neonatal chronic lung disease that is characterized by arrest of alveolar and microvascular formation as well as lung matrix remodeling. While the pathogenesis of various experimental models focus on oxygen toxicity, mechanical ventilation and inflammation, the role of nutrition before and after birth remain poorly investigated. There is accumulating clinical and experimental evidence that intrauterine growth restriction (IUGR) as a consequence of limited nutritive supply due to placental insufficiency or maternal malnutrition is a major risk factor for BPD and impaired lung function later in life. In contrast, a surplus of nutrition with perinatal maternal obesity, accelerated postnatal weight gain and early childhood obesity is associated with wheezing and adverse clinical course of chronic lung diseases, such as asthma. While the link between perinatal nutrition and lung health has been described, the underlying mechanisms remain poorly understood. There are initial data showing that inflammatory and nutrient sensing processes are involved in programming of alveolarization, pulmonary angiogenesis, and composition of extracellular matrix. Here, we provide a comprehensive overview of the current knowledge regarding the impact of perinatal metabolism and nutrition on the lung and beyond the cardiopulmonary system as well as possible mechanisms determining the individual susceptibility to CLD early in life. We aim to emphasize the importance of unraveling the mechanisms of perinatal metabolic programming to develop novel preventive and therapeutic avenues.

Perinatal Inflammation: Could Partial Blocking of Cell Adhesion Molecule Function Be a Solution?

In spite of the great advances made in recent years in prenatal and perinatal medicine, inflammation can still frequently result in injury to vital organs and often constitutes a major cause of morbidity. It is today well established that in neonates—though vulnerability to infection among neonates is triggered by functional impairments in leukocyte adhesion—the decreased expression of cell adhesion molecules also decreases the inflammatory response. It is also clear that the cell adhesion molecules, namely, the integrins, selectins, and the immunoglobulin (Ig) gene super family, all play a crucial role in the inflammatory cascade. Thus, by consolidating our knowledge concerning the actions of these vital cell adhesion molecules during the prenatal period as well as regarding the genetic deficiencies of these molecules, notably leukocyte adhesion deficiency (LAD) I, II, and III, which can provoke severe clinical symptoms throughout the first year of life, it is anticipated that intervention involving blocking the function of cell adhesion molecules in neonatal leukocytes has the potential to constitute an effective therapeutic approach for inflammation. A promising perspective is the potential use of antibody therapy in preterm and term infants with perinatal inflammation and infection focusing on cases in which LAD is involved, while a further important scientific advance related to this issue could be the combination of small peptides aimed at the inhibition of cellular adhesion.

Early Inflammatory Measures and Neurodevelopmental Outcomes in Preterm Infants

BACKGROUND

Inflammation may be an important predictor of long-term neurodevelopment in preterm infants. The identification of specific inflammatory biomarkers that predict outcomes is an important research goal.

OBJECTIVES

The purpose of this analysis was to identify associations between an early measure of inflammation and neurodevelopment in very preterm infants and to identify differences in the relationship between inflammation and neurodevelopment based on infant gender and race.

METHODS

We conducted a secondary analysis of data from a randomized controlled trial of a caregiving intervention for preterm infants born less than 33 weeks postmenstrual age. Plasma was collected with a clinically indicated laboratory draw by neonatal intensive care unit nurses and analyzed by multiplex assay for cytokines, chemokines, and growth factors. Neurobehavior was assessed by research nurses at the time of discharge from the neonatal intensive care unit using the motor development and vigor and alertness/orientation clusters from the Neurobehavioral Assessment of the Preterm Infant. Neurodevelopment was assessed at 6 months corrected age by the developmental specialist in the hospital's neonatal follow-up clinic using the Bayley Scales of Infant Development, Third Edition. We used linear regressions to estimate the effect of cytokine levels on neurodevelopment and allowed the effects to differ by infant gender and race.

RESULTS

In a sample of 62 preterm infants with discharge neurobehavioral assessments and a sample of 40 preterm infants with 6-month neurodevelopmental assessments, we found inconsistent associations between single-time point inflammatory measures and neurobehavior or neurodevelopment in analyses of the total sample. However, regressions with interactions revealed effects for multiple inflammatory measures on early neurobehavior and neurodevelopment that differed by infant gender and race.

DISCUSSION

Although early single-time point measures of inflammation may be insufficient to predict neurodevelopment for all preterm infants, the effect of inflammation appears to differ by infant gender and race. These demographic factors may be important considerations for future studies of inflammation and neurodevelopment as well was the development of future interventions to optimize outcomes.

Pharmacokinetics of Inter-Alpha Inhibitor Proteins and Effects on Hemostasis After Hypoxic-Ischemic Brain Injury in Neonatal Rats

BACKGROUND

Hypoxic-ischemic (HI) brain injury is a leading cause of long-term neurodevelopmental morbidities in neonates. Human plasma-derived Inter-Alpha Inhibitor Proteins (hIAIPs) are neuroprotective after HI brain injury in neonatal rats. The light chain (bikunin) of hIAIPs inhibits proteases involved in the coagulation of blood. Newborns exposed to HI can be at risk for significant bleeding in the brain and other organs.

OBJECTIVE

The objectives of the present study were to assess the pharmacokinetics (PK) and the duration of bleeding after intraperitoneal (IP) administration of hIAIPs in HI-exposed male and female neonatal rats.

METHODS

HI was induced with the Rice-Vannucci method in postnatal (P) day-7 rats. After the right common carotid artery ligation, rats were exposed to 90 min of 8% oxygen. hIAIPs (30 mg/kg, IP) were given immediately after Sham or HI exposure in the PK study and serum was collected 1, 6, 12, 24, or 36 h after the injections. Serum hIAIP concentrations were measured with a competitive ELISA. ADAPT5 software was used to fit the pooled PK data considering first-order absorption and disposition. hIAIPs (60 mg/kg, IP) were given in the bleeding time studies at 0, 24 and 48 h after HI with tail bleeding times measured 72 h after HI.

RESULTS

IP administration yielded significant systemic exposure to hIAIPs with PK being affected markedly including primarily faster absorption and reduced elimination as a result of HI and modestly of sex-related differences. hIAIP administration did not affect bleeding times after HI.

CONCLUSION

These results will help to inform hIAIP dosing regimen schedules in studies of neuroprotection in neonates exposed to HI.

COVID-19 threatens maternal mental health and infant development: possible paths from stress and isolation to adverse outcomes and a call for research and practice

The COVID-19 pandemic exposed mothers to stress and social isolation during the pre- and post-natal periods. The deleterious effects of stress on both pregnant women and their infants are well documented, with research suggesting that effects are exacerbated by reduced social support. In this brief report, we summarize evidence linking stress and social isolation to negative outcomes for mothers and infants and present a conceptual model featuring inflammation as a driving mechanism. There is strong evidence that the coronavirus pandemic will affect mothers and infants through immune pathways that, in previous research, have been shown to link stress and social isolation during the pre- and post-natal periods with deficits in maternal mental health and infant well-being and development across developmental stages. We close with recommendations for novel research, policy changes, and integrated clinical care that can address these biological threats to infants and mothers while leveraging the anti-inflammatory effects of social support.

Interleukin-8 dysregulation is implicated in brain dysmaturation following preterm birth

BACKGROUND

Preterm birth is associated with dysconnectivity of structural brain networks, impaired cognition and psychiatric disease. Systemic inflammation contributes to cerebral dysconnectivity, but the immune mediators driving this association are poorly understood. We analysed information from placenta, umbilical cord and neonatal blood, and brain MRI to determine which immune mediators link perinatal systemic inflammation with dysconnectivity of structural brain networks.

METHODS

Participants were 102 preterm infants (mean gestational age 29⁺¹ weeks, range 23⁺³-32⁺⁰). Placental histopathology identified reaction patterns indicative of histologic chorioamnionitis (HCA), and a customized immunoassay of 24 inflammation-associated proteins selected to reflect the neonatal innate and adaptive immune response was performed from umbilical cord (n = 55) and postnatal day 5 blood samples (n = 71). Brain MRI scans were acquired at term-equivalent age (41⁺⁰ weeks [range 38⁺⁰-44⁺⁴ weeks]) and alterations in white matter connectivity were inferred from mean diffusivity and neurite density index across the white matter skeleton.

RESULTS

HCA was associated with elevated concentrations of C5a, C9, CRP, IL-1β, IL-6, IL-8 and MCP-1 in cord blood, and IL-8 concentration predicted HCA with an area under the receiver operator curve of 0.917 (95% CI 0.841 - 0.993, p < 0.001). Fourteen analytes explained 66% of the variance in the postnatal profile (BDNF, C3, C5a, C9, CRP, IL-1β, IL-6, IL-8, IL-18, MCP-1, MIP-1β, MMP-9, RANTES and TNF-α). Of these, IL-8 was associated with altered neurite density index across the white matter skeleton after adjustment for gestational age at birth and at scan (β = 0.221, p = 0.037).

CONCLUSIONS

These findings suggest that IL-8 dysregulation has a role in linking perinatal systemic inflammation and atypical white matter development in preterm infants.

The Relationship Between Antioxidants and Inflammation in Children With Attention Deficit Hyperactivity Disorder

Introduction

Recent studies have identified Attention Deficit Hyperactivity Disorder (ADHD) as an inflammatory condition associated with immunological and oxidative responses. Therefore, it is necessary to examine these processes in these patients. The present study aimed at investigating the relationship between the dietary intake of antioxidants, Superoxide Dismutase (SOD) activity, and the serum levels of inflammatory factors in ADHD students.

Methods

This retrospective case-control study was conducted on 64 ADHD children aged 6 - 13 years. The demographic questionnaire, Food Frequency Questionnaire, and Baecke Physical Activity Questionnaire were used for data collection. SOD activity and the serum level of inflammatory factors (homocysteine, interleukin-6, and C-reactive Protein (CRP)) were measured in all patients. According to the CRP values, 32 patients were included in the case group (CRP≥1 mg/L) and 32 patients in the control group (0≤CRP<1 mg/L).

Results

There was no significant difference between the two groups in age, sex, weight, height, and body mass index. In the case group, the mean SOD activity (P=0.034), the physical activity (P=0.04), zinc intake (P=0.02), and homocysteine levels were higher than the control group (P=0.001). Of all studied variables, the best predictors were homocysteine (OR: 1.34, 95% CI: 1.082-1.670, P=0.029) and physical activity (OR: 0.85, 95% CI: 0.761-0.952, P=0.022) respectively, whereas other variables were not significant predictors.

Conclusion

The present study showed that the level of inflammatory factors in the case group was significantly higher than the control group. Homocysteine and physical activity can predict the inflammation status induced by CRP.

Transcutaneous Auricular Vagus Nerve Stimulation-Paired Rehabilitation for Oromotor Feeding Problems in Newborns: An Open-Label Pilot Study

Neonates born premature or who suffer brain injury at birth often have oral feeding dysfunction and do not meet oral intake requirements needed for discharge. Low oral intake volumes result in extended stays in the hospital (>2 months) and can lead to surgical implant and explant of a gastrostomy tube (G-tube). Prior work suggests pairing vagus nerve stimulation (VNS) with motor activity accelerates functional improvements after stroke, and transcutaneous auricular VNS (taVNS) has emerged as promising noninvasive form of VNS. Pairing taVNS with bottle-feeding rehabilitation may improve oromotor coordination and lead to improved oral intake volumes, ultimately avoiding the need for G-tube placement. We investigated whether taVNS paired with oromotor rehabilitation is tolerable and safe and facilitates motor learning in infants who have failed oral feeding. We enrolled 14 infants [11 premature and 3 hypoxic-ischemic encephalopathy (HIE)] who were slated for G-tube placement in a prospective, open-label study of taVNS-paired rehabilitation to increase feeding volumes. Once-daily taVNS was delivered to the left tragus during bottle feeding for 2 weeks, with optional extension. The primary outcome was attainment of oral feeding volumes and weight gain adequate for discharge without G-tube while also monitoring discomfort and heart rate (HR) as safety outcomes. We observed no adverse events related to stimulation, and stimulation-induced HR reductions were transient and safe and likely confirmed vagal engagement. Eight of 14 participants (57%) achieved adequate feeding volumes for discharge without G-tube (mean treatment length: 16 ± 6 days). We observed significant increases in feeding volume trajectories in responders compared with pre-stimulation (p < 0.05). taVNS-paired feeding rehabilitation appears safe and may improve oral feeding in infants with oromotor dyscoordination, increasing the rate of discharge without G-tube, warranting larger controlled trials.

Prenatal opioid exposure: The next neonatal neuroinflammatory disease

The rates of opioid use disorder during pregnancy have more than quadrupled in the last decade, resulting in numerous infants suffering exposure to opioids during the perinatal period, a critical period of central nervous system (CNS) development. Despite increasing use, the characterization and definition of the molecular and cellular mechanisms of the long-term neurodevelopmental impacts of opioid exposure commencing in utero remains incomplete. Thus, in consideration of the looming public health crisis stemming from the multitude of infants with prenatal opioid exposure entering school age, we undertook an investigation of the effects of perinatal methadone exposure in a novel preclinical model. Specifically, we examined the effects of opioids on the developing brain to elucidate mechanisms of putative neural cell injury, to identify diagnostic biomarkers and to guide clinical studies of outcome and follow-up. We hypothesized that methadone would induce a pronounced inflammatory profile in both dams and their pups, and be associated with immune system dysfunction, sustained CNS injury, and altered cognition and executive function into adulthood. This investigation was conducted using a combination of cellular, molecular, biochemical, and clinically translatable biomarker, imaging and cognitive assessment platforms. Data reveal that perinatal methadone exposure increases inflammatory cytokines in the neonatal peripheral circulation, and reprograms and primes the immune system through sustained peripheral immune hyperreactivity. In the brain, perinatal methadone exposure not only increases chemokines and cytokines throughout a crucial developmental period, but also alters microglia morphology consistent with activation, and upregulates TLR4 and MyD88 mRNA. This increase in neuroinflammation coincides with reduced myelin basic protein and altered neurofilament expression, as well as reduced structural coherence and significantly decreased fractional anisotropy on diffusion tensor imaging. In addition to this microstructural brain injury, adult rats exposed to methadone in the perinatal period have significant impairment in associative learning and executive control as assessed using touchscreen technology. Collectively, these data reveal a distinct systemic and neuroinflammatory signature associated with prenatal methadone exposure, suggestive of an altered CNS microenvironment, dysregulated developmental homeostasis, complex concurrent neural injury, and imaging and cognitive findings consistent with clinical literature. Further investigation is required to define appropriate therapies targeted at the neural injury and improve the long-term outcomes for this exceedingly vulnerable patient population.

Perinatal Opioid Exposure Primes the Peripheral Immune System Toward Hyperreactivity

The increased incidence of opioid use during pregnancy warrants investigation to reveal the impact of opioid exposure on the developing fetus. Exposure during critical periods of development could have enduring consequences for affected individuals. Particularly, evidence is mounting that developmental injury can result in immune priming, whereby subsequent immune activation elicits an exaggerated immune response. This maladaptive hypersensitivity to immune challenge perpetuates dysregulated inflammatory signaling and poor health outcomes. Utilizing an established preclinical rat model of perinatal methadone exposure, we sought to investigate the consequences of developmental opioid exposure on in vitro activation of peripheral blood mononuclear cells (PBMCs). We hypothesize that PBMCs from methadone-exposed rats would exhibit abnormal chemokine and cytokine expression at baseline, with exaggerated chemokine and cytokine production following immune stimulation compared to saline-exposed controls. On postnatal day (P) 7, pup PMBCs were isolated and cultured, pooling three pups per n. Following 3 and 24 h, the supernatant from cultured PMBCs was collected and assessed for inflammatory cytokine and chemokine expression at baseline or lipopolysaccharide (LPS) stimulation using multiplex electrochemiluminescence. Following 3 and 24 h, baseline production of proinflammatory chemokine and cytokine levels were significantly increased in methadone PBMCs (p < 0.0001). Stimulation with LPS for 3 h resulted in increased tumor necrosis factor (TNF-α) and C-X-C motif chemokine ligand 1 (CXCL1) expression by 3.5-fold in PBMCs from methadone-exposed PBMCs compared to PBMCs from saline-exposed controls (p < 0.0001). Peripheral blood mononuclear cell hyperreactivity was still apparent at 24 h of LPS stimulation, evidenced by significantly increased TNF-α, CXCL1, interleukin 6 (IL-6), and IL-10 production by methadone PMBCs compared to saline control PBMCs (p < 0.0001). Together, we provide evidence of increased production of proinflammatory molecules from methadone PBMCs at baseline, in addition to sustained hyperreactivity relative to saline-exposed controls. Exaggerated peripheral immune responses exacerbate inflammatory signaling, with subsequent consequences on many organ systems throughout the body, such as the developing nervous system. Enhanced understanding of these inflammatory mechanisms will allow for appropriate therapeutic development for infants who were exposed to opioids during development. Furthermore, these data highlight the utility of this in vitro PBMC assay technique for future biomarker development to guide specific treatment for patients exposed to opioids during gestation.

Early Postnatal IGF-1 and IGFBP-1 Blood Levels in Extremely Preterm Infants: Relationships with Indicators of Placental Insufficiency and with Systemic Inflammation

OBJECTIVE

To evaluate to what extent indicators of placenta insufficiency are associated with low concentrations of insulin-like growth factor 1 (IGF-1) and IGF-1-binding protein-1 (IGFBP-1) in neonatal blood, and to what extent the concentrations of these growth factors are associated with concentrations of proteins with inflammatory, neurotrophic, or angiogenic properties.

STUDY DESIGN

Using multiplex immunoassays, we measured the concentrations of IGF-1 and IGFBP-1, as well as 25 other proteins in blood spots collected weekly from ≥ 880 infants born before the 28th week of gestation, and sought correlates of concentrations in the top and bottom quartiles for gestational age and day the specimen was collected.

RESULTS

Medically indicated delivery and severe fetal growth restriction (sFGR) were associated with low concentrations of IGF-1 on the first postnatal day and with high concentrations of IGFBP-1 on almost all days. Elevated concentrations of IGF-1 and IGFBP-1 were accompanied by elevated concentrations of many other proteins with inflammatory, neurotrophic, or angiogenic properties.

CONCLUSION

Disorders associated with impaired placenta implantation and sFGR appear to account for a relative paucity of IGF-1 on the first postnatal day. Elevated concentrations of IGF-1 and especially IGFBP-1 were associated with same-day elevated concentrations of inflammatory, neurotrophic, and angiogenic proteins.

Inflammatory mediators of stress exposure and neurodevelopment in very preterm infants: Protocol for the stress neuro-immune study

AIMS

(a) Determine relationships among stress exposure, inflammation, and neurodevelopment in very preterm infants and determine the mediated effect of inflammation on the relationship between stress exposure and neurodevelopment; (b) describe cytokine trajectories following birth and determine the effect of stress exposure on these trajectories; and (c) examine relationships between stress exposure and chronic stress responses in very preterm infants.

DESIGN

Non-experimental, repeated measures.

METHODS

Very preterm infants born 28-31 weeks post menstrual age will be enrolled. Cumulative stress exposure over the first 14 days of life will be measured using the Neonatal Infant Stressor Scale. Blood will be collected weekly for the quantification of cytokines. Neurodevelopment will be assessed using the Neurobehavioral Assessment of the Preterm Infant and hair for quantification of hair cortisol will be collected at 35 weeks post menstrual age. Multiple linear regression and conditional process analysis will be used to analyse the relationships among stress exposure, inflammation and neurodevelopment. Linear mixed models will be used to determine inflammatory trajectories over time. IRB approval for the study was received May 2017, and funding from the National Institute of Nursing Research was awarded July 2017.

DISCUSSION

This study will determine the extent to which inflammation mediates the relationship between stress exposure and neurodevelopment. Interventions to attenuate inflammation in preterm infants may improve outcomes.

IMPACT

Determining the potentially modifiable mediators of stress exposure and neurodevelopment in preterm infants is critical to improving long-term outcomes.

An Integrative Review of Cytokine/Chemokine Predictors of Neurodevelopment in Preterm Infants

Preterm infants are at risk of brain injury and poor neurodevelopmental outcomes including impairments in cognition, behavioral functioning, sensory perception, and motor performance. Systemic inflammation has been identified as an important, potentially modifiable precursor of neurologic and neurodevelopmental impairments. Inflammation is typically measured by quantifying circulating cytokines and chemokines. However, it is unclear which specific cytokines/chemokines most consistently predict neurodevelopment in preterm infants. In this integrative review, we evaluated and analyzed the literature (N = 37 publications) to determine the cytokines/chemokines most predictive of neurodevelopment in preterm infants, the optimal timing for these measurements, and the ideal source for collecting cytokines/chemokines. Synthesis of the findings of these studies revealed that interleukin (IL)-6, IL-1β, IL-8, and tumor necrosis factor (TNF)-α collected during the first 3 weeks of life are most predictive of subsequent neurodevelopment. Methodological variation among studies hinders more specific analysis, including the evaluation of cytokine thresholds and meta-analyses, that would allow for the use of cytokines/chemokines to predict neurodevelopment. Future research should focus on identifying explicit cytokine values, specifically for IL-6, IL-1β, IL-8, and TNF-α, that are most predictive for identifying preterm infants most at risk of impairment, keeping in mind that longitudinal measures of cytokines/chemokines may be more predictive of future outcomes than single-time point measures.

Executive Dysfunction Early Postnatal Biomarkers among Children Born Extremely Preterm

We evaluated the relationship between blood levels of inflammatory and neurotrophic proteins during the first postnatal month in 692 children born before the 28th week of gestation and executive function limitations among those 10-year olds who had an IQ ≥ 70. The measures of dysfunction were Z-scores ≤ -1 on the Differential Ability Scales-II working memory (WM) assessment) (N = 164), the NEPSY-II (A Developmental NEuroPSYchological Assessment-II) Inhibition-Inhibition assessment) (N = 350), the NEPSY-II Inhibition-Switching assessment) (N = 345), as well as a Z-score ≤ -1 on all three assessments (identified as the executive dysfunction composite (N = 104). Increased risks of the executive dysfunction composite associated with high concentrations of inflammatory proteins (IL-8, TNF-α, and ICAM-1) were modulated by high concentrations of neurotrophic proteins. This pattern of modulation by neurotrophins of increased risk associated with inflammation was also seen for the working memory limitation, but only with high concentrations of IL-8 and TNF-α, and the switching limitation, but only with high concentrations of ICAM-1. We infer that among children born extremely preterm, risks of executive function limitations might be explained by perinatal systemic inflammation in the absence of adequate neurotrophic capability.

The Impact of Systemic Inflammation on Neurodevelopment

Inflammatory mediators affect the brain during development. Neurodevelopmental disorders such as autism spectrum disorders, cognitive impairment, cerebral palsy, epilepsy, and schizophrenia have been linked to early life inflammation. Recent advances have shown the effects of systemic inflammation on children's neurodevelopment. We discuss the potential mechanisms by which inflammatory molecules can exert their effects on the developing brain and consider the roles of MHC class I molecules, the HPA axis, glial cells, and monoamine metabolism. Methods to prevent the effects of cytokine imbalance may lead to the development of new therapeutics for neuropsychiatric disorders. Future research should focus on identifying at-risk individuals and early effective interventions to prevent long-term neurodevelopmental disabilities.

Circulating biomarkers in extremely preterm infants associated with ultrasound indicators of brain damage

AIM

To assess to what extent the blood concentrations of proteins with neurotrophic and angiogenic properties measured during the first postnatal month convey information about the risk of sonographically-identified brain damage among very preterm newborns.

METHODS

Study participants were 1219 children who had a cranial ultrasound scan during their stay in the intensive care nursery and blood specimens collected on 2 separate days at least a week apart during the first postnatal month. Concentrations of selected proteins in blood spots were measured with electrochemiluminescence or with a multiplex immunobead assay and the risks of cranial ultrasound images associated with top-quartile concentrations were assessed.

RESULTS

High concentrations of multiple inflammation-related proteins during the first 2 postnatal weeks were associated with increased risk of ventriculomegaly, while high concentrations of just 3 inflammation-related proteins were associated with increased risk of an echolucent/hypoechoic lesion (IL-6, IL-8, ICAM-1), especially on day 7. Concomitant high concentrations of IL6R and bFGF appeared to modulate the increased risks of ventriculomegaly and an echolucent lesion associated with inflammation. More commonly high concentrations of putative protectors/repair-enhancers did not appear to diminish these increased risks.

CONCLUSION

Our findings provide support for the hypothesis that endogenous proteins are capable of either protecting the brain against damage and/or enhancing repair of damage.

Antecedents of Screening Positive for Attention Deficit Hyperactivity Disorder in Ten-Year-Old Children Born Extremely Preterm

BACKGROUND

The incidence of attention deficit hyperactivity disorder is higher among children born very preterm than among children who are mature at birth.

METHODS

We studied 583 ten-year-old children who were born before 28 weeks of gestation whose IQ was above 84 and had a parent-completed Child Symptom Inventory-4, which allowed classification of the child as having or not having symptoms of attention deficit hyperactivity disorder. For 422 children, we also had a teacher report, and for 583 children, we also had a parent report of whether or not a physician made an attention deficit hyperactivity disorder diagnosis.

RESULTS

The risk profile of screening positive for attention deficit hyperactivity disorder based on a parent's report differed from the risk profile based on the teacher's report, whereas the risk profile according to a physician and according to any two observers closely resembled the parent-reported profile. Among the statistically significant risk factors were young maternal age (parent, physician, and two observers), maternal obesity (parent, physician, and two observers), maternal smoking (parent, physician, and two observers), magnesium given at delivery for seizure prophylaxis (parent and two observers), recovery of Mycoplasma sp. from the placenta (teacher and two observers), low gestational age (parent and two observers), low birth weight (teacher and physician), singleton (parent, physician, and two observers), male (parent, teacher, physician, and two observers), mechanical ventilation on postnatal day seven (physician), receipt of a sedative (parent and two observers), retinopathy of prematurity (parent), necrotizing enterocolitis (physician), antibiotic receipt (physician and two observers), and ventriculomegaly on brain scan (parent and two observers).

CONCLUSIONS

The multiplicity of risk factors identified can be subsumed as components of four broad themes: low socioeconomic state, immaturity or vulnerability, inflammation, and epigenetic phenomena.

Placental CpG methylation of infants born extremely preterm predicts cognitive impairment later in life

Background

The placenta is the central regulator of maternal and fetal interactions. Perturbations of placental structure and function have been associated with adverse neurodevelopmental outcomes later in life. Placental CpG methylation represents an epigenetic modification with the potential to impact placental function, fetal development and child health later in life.

Study design

Genome-wide placental CpG methylation levels were compared between spontaneous versus indicated deliveries from extremely preterm births (EPTBs) (n = 84). The association between the identified differentially methylated CpG sites and neurocognitive outcome at ten years of age was then evaluated.

Results

Spontaneous EPTB was associated with differential CpG methylation levels in 250 CpG sites (217 unique genes) with the majority displaying hypermethylation. The identified genes are known to play a role in neurodevelopment and are enriched for basic helix-loop-helix transcription factor binding sites. The placental CpG methylation levels for 17 of these sites predicted cognitive function at ten years of age.

Conclusion

A hypermethylation signature is present in DNA from placentas in infants with spontaneous EPTB. CpG methylation levels of critical neurodevelopment genes in the placenta predicted later life cognitive function, supporting the developmental origins of health and disease hypothesis (DOHaD).

Stem cells and cell-based therapies for cerebral palsy: a call for rigor

Cell-based therapies hold significant promise for infants at risk for cerebral palsy (CP) from perinatal brain injury (PBI). PBI leading to CP results from multifaceted damage to neural cells. Complex developing neural networks are injured by neural cell damage plus unique perturbations in cell signaling. Given that cell-based therapies can simultaneously repair multiple injured neural components during critical neurodevelopmental windows, these interventions potentially offer efficacy for patients with CP. Currently, the use of cell-based interventions in infants at risk for CP is limited by critical gaps in knowledge. In this review, we will highlight key questions facing the field, including: Who are optimal candidates for treatment? What are the goals of therapeutic interventions? What are the best strategies for agent delivery, including timing, dosage, location, and type? And, how are short- and long-term efficacy reliably tracked? Challenges unique to treating PBI with cell-based therapies, and lessons learned from cell-based therapies in closely related neurological disorders in the mature central nervous system, will be reviewed. Our goal is to update pediatric specialists who may be counseling families about the current state of the field. Finally, we will evaluate how rigor can be increased in the field to ensure the safety and best interests of this vulnerable patient population.

Preclinical chorioamnionitis dysregulates CXCL1/CXCR2 signaling throughout the placental-fetal-brain axis

In the United States, perinatal brain injury (PBI) is a major cause of infant mortality and childhood disability. For a large proportion of infants with PBI, central nervous system (CNS) injury begins in utero with inflammation (chorioamnionitis/CHORIO) and/or hypoxia-ischemia. While studies show CHORIO contributes to preterm CNS injury and is also a common independent risk factor for brain injury in term infants, the molecular mechanisms mediating inflammation in the placental-fetal-brain axis that result in PBI remain a gap in knowledge. The chemokine (C-X-C motif) ligand 1 (CXCL1), and its cognate receptor, CXCR2, have been clinically implicated in CHORIO and in mature CNS injury, although their specific role in PBI pathophysiology is poorly defined. Given CXCL1/CXCR2 signaling is essential to neural cell development and neutrophil recruitment, a key pathological hallmark of CHORIO, we hypothesized CHORIO would upregulate CXCL1/CXCR2 expression in the placenta and fetal circulation, concomitant with increased CXCL1/CXCR2 signaling in the developing brain, immune cell activation, neutrophilia, and microstructural PBI. On embryonic day 18 (E18), a laparotomy was performed in pregnant Sprague Dawley rats to induce CHORIO. Specifically, uterine arteries were occluded for 60min to induce placental transient systemic hypoxia-ischemia (TSHI), followed by intra-amniotic injection of lipopolysaccharide (LPS). Pups were born at E22. Placentae, serum and brain were collected along an extended time course from E19 to postnatal day (P)15 and analyzed using multiplex electrochemiluminescence (MECI), Western blot, qPCR, flow cytometry (FC) and diffusion tensor imaging (DTI). Results demonstrate that compared to sham, CHORIO increases placental CXCL1 and CXCR2 mRNA levels, concomitant with increased CXCR2⁺ neutrophils. Interestingly, pup serum CXCL1 expression in CHORIO parallels this increase, with sustained elevation through P15. Analyses of CHORIO brains reveal similarly increased CXCL1/CXCR2 expression through P7, together with increased neutrophilia, microgliosis and peripheral macrophages. Similar to the placenta, cerebral neutrophilia was defined by increased CXCR2 surface expression and elevated myeloperoxidase expression (MPO), consistent with immune cell activation. Evaluation of microstructural brain injury at P15 with DTI reveals aberrant microstructural integrity in the callosal and capsular white matter, with reduced fractional anisotropy in superficial and deep layers of overlying cortex. In summary, using an established model of CHORIO that exhibits mature CNS deficits mimicking those of preterm survivors, we show CHORIO induces injury throughout the placental-fetal-brain axis with a CXCL1/CXCR2 inflammatory signature, neutrophilia, and microstructural abnormalities. These data are concomitant with abnormal cerebral CXCL1/CXCR2 expression, and support temporal aberrations in CXCL1/CXCR2 and neutrophil dynamics in the placental-fetal-brain axis following CHORIO. These investigations define novel targets for directed therapies for infants at high risk for PBI.

Reactive astrocyte COX2-PGE2 production inhibits oligodendrocyte maturation in neonatal white matter injury

Inflammation is a major risk factor for neonatal white matter injury (NWMI), which is associated with later development of cerebral palsy. Although recent studies have demonstrated maturation arrest of oligodendrocyte progenitor cells (OPCs) in NWMI, the identity of inflammatory mediators with direct effects on OPCs has been unclear. Here, we investigated downstream effects of pro-inflammatory IL-1β to induce cyclooxygenase-2 (COX2) and prostaglandin E2 (PGE2) production in white matter. First, we assessed COX2 expression in human fetal brain and term neonatal brain affected by hypoxic-ischemic encephalopathy (HIE). In the developing human brain, COX2 was expressed in radial glia, microglia, and endothelial cells. In human term neonatal HIE cases with subcortical WMI, COX2 was strongly induced in reactive astrocytes with "A2" reactivity. Next, we show that OPCs express the EP1 receptor for PGE2, and PGE2 acts directly on OPCs to block maturation in vitro. Pharmacologic blockade with EP1-specific inhibitors (ONO-8711, SC-51089), or genetic deficiency of EP1 attenuated effects of PGE2. In an IL-1β-induced model of NWMI, astrocytes also exhibit "A2" reactivity and induce COX2. Furthermore, in vivo inhibition of COX2 with Nimesulide rescues hypomyelination and behavioral impairment. These findings suggest that neonatal white matter astrocytes can develop "A2" reactivity that contributes to OPC maturation arrest in NWMI through induction of COX2-PGE2 signaling, a pathway that can be targeted for neonatal neuroprotection.

Neurocognitive Outcomes at 10 Years of Age in Extremely Preterm Newborns with Late-Onset Bacteremia

OBJECTIVE

To evaluate the difference in 10-year neurocognitive outcomes between extremely low gestational age newborns without bacteremia and those with suspected or confirmed late-onset bacteremia.

STUDY DESIGN

Neurocognitive function was evaluated at 10 years of age in 889 children born at <28 weeks of gestation and followed from birth. Definite (culture-positive) late-onset bacteremia during postnatal weeks 2-4 was identified in 223 children, and 129 children had suspected bacteremia.

RESULTS

Infants with the lowest gestational age and birth weight z-score had the highest prevalence of definite and suspected late-onset bacteremia. Compared with peers with no or suspected bacteremia, infants with definite bacteremia performed worse on tests of general cognitive ability, language, academic achievement, and executive function, even after adjustment for potential confounders. Adjustment for low IQ attenuated the associations between bacteremia and all dysfunctions at age 10 years. Children with suspected bacteremia did not differ appreciably from those with no evidence of bacteremia. The motor domain was unaffected.

CONCLUSIONS

Extremely low gestational age newborns who had definite late bacteremia during postnatal weeks 2-4 are at heightened risk of neurocognitive limitations at age 10 years.

The Relationship of Maternal Prepregnancy Body Mass Index and Pregnancy Weight Gain to Neurocognitive Function at Age 10 Years among Children Born Extremely Preterm

OBJECTIVE

To assess the association between maternal prepregnancy body mass index and adequacy of pregnancy weight gain in relation to neurocognitive function in school-aged children born extremely preterm.

STUDY DESIGN

Study participants were 535 ten-year-old children enrolled previously in the prospective multicenter Extremely Low Gestational Age Newborns cohort study who were products of singleton pregnancies. Soon after delivery, mothers provided information about prepregnancy weight. Prepregnancy body mass index and adequacy of weight gain were characterized based on this information. Children underwent a neurocognitive evaluation at 10 years of age.

RESULTS

Maternal prepregnancy obesity was associated with increased odds of a lower score for Differential Ability Scales-II Verbal IQ, for Developmental Neuropsychological Assessment-II measures of processing speed and visual fine motor control, and for Wechsler Individual Achievement Test-III Spelling. Children born to mothers who gained an excessive amount of weight were at increased odds of a low score on the Oral and Written Language Scales Oral Expression assessment. Conversely, children whose mother did not gain an adequate amount of weight were at increased odds of a lower score on the Oral and Written Language Scales Oral Expression and Wechsler Individual Achievement Test-III Word Reading assessments.

CONCLUSION

In this cohort of infants born extremely preterm, maternal obesity was associated with poorer performance on some assessments of neurocognitive function. Our findings are consistent with the observational and experimental literature and suggest that opportunities may exist to mitigate risk through education and behavioral intervention before pregnancy.

Early Life Inflammation and Neurodevelopmental Outcome in Bangladeshi Infants Growing Up in Adversity

Exposure to profound adversity can negatively affect the neurodevelopment of children, but biologic mechanisms that underlie this association remain unknown. We sought to determine whether elevated levels of the inflammatory markers C-reactive protein (CRP) and soluble CD14 (sCD14) are associated with neurodevelopmental outcomes in Bangladeshi children. A total of 422 infant-mother pairs from an urban slum in Dhaka, Bangladesh were enrolled at birth and followed prospectively. Inflammation was measured with sCD14, interleukin (IL)-1β, and IL-6 at 18 weeks, and CRP at 6, 18, 40, and 53 weeks. Psychologists assessed cognitive, language, motor, and social emotional development using the Bayley Scales of Infant and Toddler Development at 78 and 104 weeks of age. We tested for the association of inflammatory markers with developmental outcomes, independent of previously identified associations such as malnutrition, family income, and maternal education. Every 10 pg/mL increase in sCD14 was associated with a 1.1-2.0 decrement in cognitive and motor scores at 78 weeks and in all domains at 104 weeks. The cumulative number of CRP elevations that a child experienced in the first year of life, as well as IL-1β and IL-6 at 18 weeks of age, were also negatively associated with Bayley Scales results. CRP, sCD14, IL-1β, and IL-6 were associated with lower neurodevelopmental outcomes. Our findings implicate a role of inflammation in the neurodevelopment of children growing up in adversity.

Systemic Inflammation during the First Postnatal Month and the Risk of Attention Deficit Hyperactivity Disorder Characteristics among 10 year-old Children Born Extremely Preterm

Although multiple sources link inflammation with attention difficulties, the only human study that evaluated the relationship between systemic inflammation and attention problems assessed attention at age 2 years. Parent and/or teacher completion of the Childhood Symptom Inventory-4 (CSI-4) provided information about characteristics that screen for attention deficit hyperactive disorder (ADHD) among 793 10-year-old children born before the 28th week of gestation who had an IQ ≥ 70. The concentrations of 27 proteins in blood spots obtained during the first postnatal month were measured. 151 children with ADHD behaviors were identified by parent report, while 128 children were identified by teacher report. Top-quartile concentrations of IL-6R, TNF-α, IL-8, VEGF, VEFG-R1, and VEGF-R2 on multiple days were associated with increased risk of ADHD symptoms as assessed by a teacher. Some of this increased risk was modulated by top-quartile concentrations of IL-6R, RANTES, EPO, NT-4, BDNF, bFGF, IGF-1, PIGF, Ang-1, and Ang-2. Systemic inflammation during the first postnatal month among children born extremely preterm appears to increase the risk of teacher-identified ADHD characteristics, and high concentrations of proteins with neurotrophic properties appear capable of modulating this increased risk.