Cytokines and neurodevelopmental outcomes in extremely low birth weight infants

Genomic Differences between Spontaneous versus Indicated Extreme Preterm Birth

OBJECTIVE

 Extremely preterm infants are at high risk of neonatal mortality and morbidity. Extreme preterm birth (PTB) may result from spontaneous preterm labor or preterm premature rupture of membranes or may be indicated due to preeclampsia, eclampsia, hypertension, or other causes. Our objective was to identify single nucleotide polymorphisms (SNPs) and biological pathways associated with spontaneous versus indicated extreme PTB using the neonatal genome.

STUDY DESIGN

 We evaluated 523 spontaneous births and 134 indicated births weighing 401 to 1,000 g at birth from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network's Genomics dataset by genome-wide association study (GWAS) and pathway analysis. The TOLSURF cohort was used to replicate the results.

RESULTS

 In the NRN GWAS, no statistically significant results were found, although the Manhattan plot showed one almost significant peak (rs60854043 on chromosome 14 at p = 1.03E-07) along with many other modest peaks at p = 1-9E-06, for a total of 15 suggestive associations at this locus. In the NRN pathway analysis, multiple pathways were identified, with the most significant being "GO_mf:go_low_density_lipoprotein_particle_receptor_activity" at p = 1.14E-06. However, these results could not be replicated in the TOLSURF cohort.

CONCLUSION

 Genomic differences are seen between infants born by spontaneous versus indicated extreme PTB. Due to the limited sample size, there is a need for larger studies.

KEY POINTS

· Genomic differences are seen between infants born by spontaneous versus indicated very PTB.. · Future studies with large sample sizes evaluating extreme PTB are necessary.. · Spontaneous PTB is more common than indicated extreme PTB..

Genetic pathways in cerebral palsy: a review of the implications for precision diagnosis and understanding disease mechanisms

ABSTRACT

Cerebral palsy is a diagnostic term utilized to describe a group of permanent disorders affecting movement and posture. Patients with cerebral palsy are often only capable of limited activity, resulting from non-progressive disturbances in the fetal or neonatal brain. These disturbances severely impact the child's daily life and impose a substantial economic burden on the family. Although cerebral palsy encompasses various brain injuries leading to similar clinical outcomes, the understanding of its etiological pathways remains incomplete owing to its complexity and heterogeneity. This review aims to summarize the current knowledge on the genetic factors influencing cerebral palsy development. It is now widely acknowledged that genetic mutations and alterations play a pivotal role in cerebral palsy development, which can be further influenced by environmental factors. Despite continuous research endeavors, the underlying factors contributing to cerebral palsy remain are still elusive. However, significant progress has been made in genetic research that has markedly enhanced our comprehension of the genetic factors underlying cerebral palsy development. Moreover, these genetic factors have been categorized based on the identified gene mutations in patients through clinical genotyping, including thrombosis, angiogenesis, mitochondrial and oxidative phosphorylation function, neuronal migration, and cellular autophagy. Furthermore, exploring targeted genotypes holds potential for precision treatment. In conclusion, advancements in genetic research have substantially improved our understanding of the genetic causes underlying cerebral palsy. These breakthroughs have the potential to pave the way for new treatments and therapies, consequently shaping the future of cerebral palsy research and its clinical management. The investigation of cerebral palsy genetics holds the potential to significantly advance treatments and management strategies. By elucidating the underlying cellular mechanisms, we can develop targeted interventions to optimize outcomes. A continued collaboration between researchers and clinicians is imperative to comprehensively unravel the intricate genetic etiology of cerebral palsy.

Neonatal inflammation and its association with asthma and obesity in late childhood among individuals born extremely preterm

BACKGROUND

Asthma and obesity are frequent outcomes among individuals born extremely preterm and are associated with decreased lifespan. Neonatal inflammation is associated with chronic neurodevelopmental disorders; however, it is less studied in association with other later childhood chronic disorders in this population.

METHODS

Fourteen hospitals in 5 U.S. states enrolled 1506 infants born before 28 weeks of gestation in the Extremely Low Gestational Age Newborn cohort in 2004-2014. Neonatal blood spots were collected on postnatal days 1, 7, 14, 21, and 28, and used to measure 14 inflammation-related proteins. Associations were evaluated between high (top quartile) levels of proteins and two chronic health disorders at ages 10 and 15 years: physician-diagnosed asthma and obesity (body mass index ≥95th percentile).

RESULTS

Few associations were found between high levels of 14 inflammation-related proteins, either on a single day or on multiple days, and either asthma or obesity. Similarly, few associations were found in analyses stratified by sex or presence/absence of prenatal inflammation.

CONCLUSIONS

In extremely preterm newborns, systemic elevations of inflammation-related proteins during the neonatal period were not associated with childhood asthma and obesity outcomes at 10 or 15 years of age.

IMPACT

In the large multi-center Extremely Low Gestational Age Newborn (ELGAN) cohort, sustained elevation of neonatal levels of inflammation-related proteins was not consistently associated with asthma or obesity outcomes at 10 or 15 years of age. This finding contrasts with reported associations of perinatal inflammation with obesity at 2 years and neurodevelopmental disorders at 2-15 years in the ELGANs, suggesting that unlike neurodevelopment, peripubertal obesity and asthma may be driven by later childhood exposures. Future research on perinatal mechanisms of childhood asthma and obesity should account for both fetal and later exposures and pathways in addition to inflammation at birth.

The Impact of Antenatal Corticosteroids on the Metabolome of Preterm Newborns: An Untargeted Approach

We analyzed and compared variations in the urinary metabolome, as well as postnatal clinical outcomes among preterm infants, based on the timing of antenatal corticosteroid (ACS) administration in response to preterm labor onset in their mothers. This was a prospective observational study held in the Neonatal Intensive Care Unit, Department of Woman's and Child's Health, Padova University Hospital (Italy). A urine sample was obtained from each patient within 24 h of birth; Mass Spectrometry-based untargeted metabolomics analysis was then conducted. We searched for any significant disparities in the metabolomic profile of preterm newborns subjected to antenatal corticosteroid (ACS) treatment at varying timings; their correlation with clinical outcomes were also evaluated. The group receiving ACS within the optimal time window (1-7 days before delivery) exhibited elevated levels of cysteine, N-acetylglutamine, propionyl carnitine and 5-hydroxyindolacetic acid, coupled with a decrease in pipecolic acid. Clinically, this group demonstrated a reduced need for invasive ventilation (p = 0.04). In conclusion, metabolomics analysis identified several metabolites that discriminated preterm infants whose mothers received ACS within the recommended time window. Elevated levels of cysteine and 5-Hydroxyindoleacetic acid, metabolites characterized by antioxidant and anti-inflammatory properties, were observed in these infants. This metabolic profile correlated with improved respiratory outcomes, as evidenced by a reduced necessity for invasive ventilation at birth.

Genetic Predisposition to Adverse Neurodevelopmental Outcome of Extremely Low Birth Weight Infants

OBJECTIVE

 This study aimed to evaluate whether there are genetic variants associated with adverse neurodevelopmental outcomes in extremely low birth weight (ELBW) infants.

STUDY DESIGN

 We conducted a candidate gene association study in two well-defined cohorts of ELBW infants (<1,000 g). One cohort was for discovery and the other for replication. The discovery case-control analysis utilized anonymized DNA samples and evaluated 1,614 single-nucleotide polymorphisms (SNPs) in 145 genes concentrated in inflammation, angiogenesis, brain development, and oxidation pathways. Cases were children who died by age one or who were diagnosed with cerebral palsy (CP) or neurodevelopmental delay (Bayley II mental developmental index [MDI] or psychomotor developmental index [PDI] < 70) by 18 to 22 months. Controls were survivors with normal neurodevelopment. We assessed significant epidemiological variables and SNPs associated with the combined outcome of CP or death, CP, mental delay (MDI < 70) and motor delay (PDI < 70). Multivariable analyses adjusted for gestational age at birth, small for gestational age, sex, antenatal corticosteroids, multiple gestation, racial admixture, and multiple comparisons. SNPs associated with adverse neurodevelopmental outcomes with p < 0.01 were selected for validation in the replication cohort. Successful replication was defined as p < 0.05 in the replication cohort.

RESULTS

 Of 1,013 infants analyzed (452 cases, 561 controls) in the discovery cohort, 917 were successfully genotyped for >90% of SNPs and passed quality metrics. After adjusting for covariates, 26 SNPs with p < 0.01 for one or more outcomes were selected for replication cohort validation, which included 362 infants (170 cases and 192 controls). A variant in SERPINE1, which encodes plasminogen activator inhibitor (PAI1), was associated with the combined outcome of CP or death in the discovery analysis (p = 4.1 × 10-4) and was significantly associated with CP or death in the replication cohort (adjusted odd ratio: 0.4; 95% confidence interval: 0.2-1.0; p = 0.039).

CONCLUSION

 A genetic variant in SERPINE1, involved in inflammation and coagulation, is associated with CP or death among ELBW infants.

KEY POINTS

· Early preterm and ELBW infants have dramatically increased risks of CP and developmental delay.. · A genetic variant in SERPINE1 is associated with CP or death among ELBW infants.. · The SERPINE1 gene encodes the serine protease inhibitor plasminogen activator inhibitor..

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.

Prenatal lipopolysaccharide exposure induces anxiety-like behaviour in male mouse offspring and aberrant glial differentiation of embryonic neural stem cells

BACKGROUND

Prenatal infection has been implicated in the development of neuropsychiatric disorders in children. We hypothesised that exposure to lipopolysaccharide during prenatal development could induce anxiety-like behaviour and sensorineural hearing loss in offspring, as well as disrupt neural differentiation during embryonic neural development.

METHODS

We simulated prenatal infection in FVB mice and mouse embryonic stem cell (ESC) lines, specifically 46C and E14Tg2a, through lipopolysaccharide treatment. Gene expression profiling analyses and behavioural tests were utilized to study the effects of lipopolysaccharide on the offspring and alterations in toll-like receptor (TLR) 2-positive and TLR4-positive cells during neural differentiation in the ESCs.

RESULTS

Exposure to lipopolysaccharide (25 µg/kg) on gestation day 9 resulted in anxiety-like behaviour specifically in male offspring, while no effects were detected in female offspring. We also found significant increases in the expression of GFAP and CNPase, as well as higher numbers of GFAP + astrocytes and O4+ oligodendrocytes in the prefrontal cortex of male offspring. Furthermore, increased scores for genes related to oligodendrocyte and lipid metabolism, particularly ApoE, were observed in the prefrontal cortex regions. Upon exposure to lipopolysaccharide during the ESC-to-neural stem cell (NSC) transition, Tuj1, Map2, Gfap, O4, and Oligo2 mRNA levels increased in the differentiated neural cells on day 14. In vitro experiments demonstrated that lipopolysaccharide exposure induced inflammatory responses, as evidenced by increased expression of IL1b and ApoB mRNA.

CONCLUSIONS

Our findings suggest that prenatal infection at different stages of neural differentiation may result in distinct disturbances in neural differentiation during ESC-NSC transitions. Furthermore, early prenatal challenges with lipopolysaccharide selectively induce anxiety-like behaviour in male offspring. This behaviour may be attributed to the abnormal differentiation of astrocytes and oligodendrocytes in the brain, potentially mediated by ApoB/E signalling pathways in response to inflammatory stimuli.

Linking specific biological signatures to different childhood adversities: findings from the HERO project

BACKGROUND

Although investigations have begun to differentiate biological and neurobiological responses to a variety of adversities, studies considering both endocrine and immune function in the same datasets are limited.

METHODS

Associations between proximal (family functioning, caregiver depression, and anxiety) and distal (SES-D; socioeconomic disadvantage) early-life adversities with salivary inflammatory biomarkers (IL-1β, IL-6, IL-8, and TNF-α) and hair HPA markers (cortisol, cortisone, and dehydroepiandrosterone) were examined in two samples of young U.S. children (N = 142; N = 145).

RESULTS

Children exposed to higher SES-D had higher levels of TNF-α (B = 0.13, p = 0.011), IL-1β (B = 0.10, p = 0.033), and DHEA (B = 0.16, p = 0.011). Higher family dysfunction was associated with higher cortisol (B = 0.08, p = 0.033) and cortisone (B = 0.05, p = 0.003). An interaction between SES-D and family dysfunction was observed for cortisol levels (p = 0.020) whereby children exposed to lower/average levels of SES-D exhibited a positive association between family dysfunction and cortisol levels, whereas children exposed to high levels of SES-D did not. These findings were partially replicated in the second sample.

CONCLUSIONS

Our results indicate that these biological response systems may react differently to different forms of early-life adversity.

IMPACT

Different forms of early-life adversity have varied stress signatures, and investigations of early-life adversities with inflammation and HPA markers are lacking. Children with higher socioeconomic disadvantage had higher TNF-α, IL-1β, and DHEA. Higher family dysfunction was associated with higher hair cortisol and cortisone levels, and the association between family dysfunction and cortisol was moderated by socioeconomic disadvantage. Biological response systems (immune and endocrine) were differentially associated with distinct forms of early-life adversities.

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.

Neonatal infections: Insights from a multicenter longitudinal research collaborative

For more than 30 years, the Neonatal Research Network (NRN) has conducted studies addressing the epidemiology of neonatal infections, including incidence, microbiology, maternal and neonatal risk factors, associated clinical findings, and outcomes. These studies have provided clinicians and policymakers critical data needed to inform national guidance for infection risk assessment and support daily practice. Further, NRN studies have prompted research into optimal approaches to infection diagnosis, treatment, and antimicrobial stewardship. In this article, we summarize the key findings of NRN infection-related studies, with an emphasis on those published in 2000 or later.

Retrospective study of intrapartum fever in term pregnancies and adverse obstetric and neonatal outcomes

Background

Intrapartum fever is a well-known predisposing factor for severe perinatal outcomes. Herein, we explored the intrapartum features, obstetric outcomes, and neonatal outcomes in relation to the extent of intrapartum fever via three group analyses.

Methods

A retrospective cohort analysis consisting of 575 term, singleton live births in one medical center from January 1st to December 31st, 2020 was carried out. Parturients who had experienced a maximal intrapartum fever of <38.0 °C were compared with two sub-groups of parturients who had experienced respective maximal fevers of 38.0-38.9 °C and ≥39.0 °C. We computed the adjusted risks for adverse perinatal outcomes via multiple logistic regression models to control for confounders.

Results

There were statistically remarkable differences among the three groups in 13 items including body mass index, epidural, and WBC before delivery (p < 0.05). In contrast with intrapartum fevers of 37.5-37.9 °C, intrapartum fevers of 38.0-38.9 °C were linked to an elevated risk of neonatal sepsis and neonatal intensive care unit admission with an odds ratio (OR) of 4.28 (95% CI 2.162-8.479) and 1.73 (95% CI 1.125-2.666), nonetheless, the relationship was remarkably higher for intrapartum fever ≥39.0 °C, with an OR of 6.40 (95% CI 2.450-16.725) and 2.23 (95% CI 1.021-4.854). Additionally, intrapartum fevers of 38.0-38.9 °C and ≥39.0 °C were related to remarkably higher risk for operative deliveries (OR 2.24, 95% CI 1.373-3.648; OR 3.59, 95% CI 1.398-9.226; respectively) and histological chorioamnionitis (OR 3.77, 95% CI 2.261-6.271; OR 19.24, 95% CI 7.385-50.111, respectively).

Conclusions

Intrapartum fever is an important indicator of adverse perinatal outcomes. The higher the temperature, the higher risk of histological chorioamnionitis, as well as the risk of neonatal sepsis and neonatal intensive care unit admission.

An association study of IL2RA polymorphisms with cerebral palsy in a Chinese population

Background

Cerebral palsy (CP), the most common physical disability of childhood, is a nonprogressive movement disorder syndrome. Eighty percent of cases are considered idiopathic without a clear cause. Evidence has shown that cytokine abnormalities are widely thought to contribute to CP.

Methods

An association between 6 SNPs (rs12244380, rs2025345, rs12722561, rs4749926, rs2104286 and rs706778) in IL2RA (interleukin 2 receptor subunit alpha) and CP was investigated using a case–control method based on 782 CP cases and 778 controls. The allele, genotype and haplotype frequencies of SNPs were assessed using the SHEsis program. Subgroup analyses based on complications and clinical subtypes were also conducted.

Results

Globally, no differences in genotype or allele frequencies for any SNPs remained significant after Bonferroni correction between patients and controls, except rs706778, which deviated from Hardy–Weinberg equilibrium and was excluded from further analyses. However, subgroup analysis revealed a significant association of rs2025345 with spastic tetraplegia (P genotype = 0.048 after correction) and rs12722561 with CP accompanied by global developmental delay (P allele = 0.045 after correction), even after Bonferroni correction.

Conclusions

These findings indicated that genetic variations in IL2RA are significantly associated with CP susceptibility in the Chinese Han population, suggesting that IL2RA is likely involved in the pathogenesis of CP. Further investigation with a larger sample size in a multiethnic population is needed to confirm the association.

TNAP—a potential cytokine in the cerebral inflammation in spastic cerebral palsy

Objective: Several studies have shown the significance of neuroinflammation in the pathological progress of cerebral palsy (CP). However, the etiology of CP remains poorly understood. Spastic CP is the most common form of CP, comprising 80% of all cases. Therefore, identifying the specific factors may serve to understand the etiology of spastic CP. Our research aimed to find some relevant factors through protein profiling, screening, and validation to help understand the pathogenesis of cerebral palsy.

Materials and methods: In the current study, related clinical parameters were assessed in 18 children with spastic CP along with 20 healthy individuals of the same age. Blood samples of the spastic CP children and controls were analyzed with proteomics profiling to detect differentially expressed proteins. On the other hand, after hypoxic-ischemic encephalopathy (HIE) was induced in the postnatal day 7 rat pups, behavioral tests were performed followed by detection of the differentially expressed markers and inflammatory cytokines in the peripheral blood and cerebral cortex of the CP model rats by Elisa and Western blot. Independent sample t-tests, one-way analysis of variance, and the Pearson correlation were used for statistical analysis.

Results: Through proteomic analysis, differentially expressed proteins were identified. Among them, tissue-nonspecific alkaline phosphatase (TNAP), the gene expression product of alkaline phosphatase (ALPL), was downregulated in spastic CP. In addition, significantly lower TNAP levels were found in the children with CP and model rats. In contrast, compared with the sham rats, the model rats demonstrated a significant increase in osteopontin and proinflammatory biomarkers in both the plasma and cerebral cortex on the ischemic side whereas serum 25 hydroxyvitamin D and IL-10 were significantly decreased. Moreover, serum TNAP level was positively correlated with serum CRP and IL-10 in model rats.

Conclusion: These results suggest that TNAP is the potential molecule playing a specific and critical role in the neuroinflammation in spastic CP, which may provide a promising target for the diagnosis and treatment of spastic CP.

Sex-specific cytokine responses and neurocognitive outcome after blood transfusions in preterm infants

BACKGROUND

The objective of this study was to determine sex-specific differences in inflammatory cytokine responses to red blood cell (RBC) transfusion in preterm infants in the neonatal period and their relationship to later neurocognitive status.

METHODS

Infants with a birth weight <1000 g and gestational age 22-29 weeks were enrolled in the Transfusion of Prematures (TOP) trial. The total number of transfusions was used as a marker of transfusion status. Nineteen cytokines and biomarkers were analyzed from 71 infants longitudinally during the neonatal period. Twenty-six infants completed the Bayley Scales of Infant & Toddler Development, 3rd Edition (Bayley-III) at 12 months' corrected age.

RESULTS

Nine cytokine levels were significantly elevated in proportion to the number of transfusions received. Of those, one cytokine showed a sex-specific finding (p = 0.004): monocyte chemoattractant protein-1, MCP-1, rose substantially in females (8.9% change per additional transfusion), but not in males (-0.8% change). Higher concentrations of MCP-1 exclusively were associated with worse Bayley-III scores: decreased cognitive raw scores (p = 0.0005) and motor scaled scores (p < 0.0001).

CONCLUSIONS

This study provides evidence of a sex-specific difference in the inflammatory response to RBC transfusions during neonatal life, with MCP-1 levels rising only in females and inversely correlating with neurocognitive status at 12 months old.

IMPACT

It is important to understand the risk factors for abnormal neurodevelopment in preterm infants, including anemia and RBC transfusion, in order to improve outcomes and provide potential targets for therapy. Our study investigates and provides the first evidence of sex-specific differences in inflammatory cytokine responses to RBC transfusions in preterm infants in the neonatal period, and their relationship to later cognitive outcomes. This study critically suggests that different transfusion thresholds may have a sex-specific effect on neurodevelopment: females have worse cognitive outcomes with increased number of transfusions, while males have worse outcomes with lower number of transfusions.

Extreme prematurity: Risk and resiliency

Individuals born extremely preterm (before 28 weeks of gestation) comprise only about 0.7% of births in the United States and an even lower proportion in other high resource countries. However, these individuals account for a disproportionate number of children with cerebral palsy, intellectual deficit, autism spectrum disorder, attention deficit hyperactivity disorder, and epilepsy. This review describes two large multiple center cohorts comprised of individuals born extremely preterm: the EPICURE cohort, recruited 1995 in the United Kingdom and the Republic of Ireland, and the Extremely Low Gestational Age Newborn (ELGAN), recruited 2002-2004 in five states in the United States. The primary focus of these studies has been neurodevelopmental disorders, but also of interest are growth, respiratory illness, and parent- and self-reported global health and well-being. Both of these studies indicate that among individuals born extremely preterm the risks of most neurodevelopmental disorders are increased. Early life factors that contribute to this risk include perinatal brain damage, some of which can be identified using neonatal head ultrasound, bronchopulmonary dysplasia, and neonatal systemic inflammation. Prenatal factors, particularly the family's socioeconomic position, also appear to contribute to risk. For most adverse outcomes, the risk is higher in males. Young adults born extremely preterm who have neurodevelopmental impairment, as compared to those without such impairment, rate their quality of life lower. However, young adults born extremely preterm who do not have neurodevelopmental impairments rate their quality of life as being similar to that of young adults born at term. Finally, we summarize the current state of interventions designed to improve the life course of extremely premature infants, with particular focus on efforts to prevent premature birth and on postnatal efforts to prevent adverse neurodevelopmental outcomes.

Necrotizing Enterocolitis: Clinical Features, Histopathological Characteristics, and Genetic Associations

Necrotizing enterocolitis (NEC) is an inflammatory bowel necrosis seen in premature infants. Although the etiopathogenesis of NEC is unclear, genetic factors may alter a patient's susceptibility, clinical course, and outcomes. This review draws from existing studies focused on individual genes and others based on microarray-based high-throughput discovery techniques. We have included evidence from our own studies and from an extensive literature search in the databases PubMed, EMBASE, and Scopus. To avoid bias in the identification of studies, keywords were short-listed a priori from anecdotal experience and PubMed's Medical Subject Heading (MeSH) thesaurus.

Effects of a tripartite intervention on biological stress in preterm infants during heel pricks for newborn screening: A randomized controlled trial

This prospective randomized trial examined the effects of a tripartite intervention (behavioral state modulation + nonnutritive sucking + tucking) on stress from procedural pain during heel pricks. Blood samples for routine screening were collected by heel pricks 48 h after birth (Stage 1) and at ≥37 weeks' gestation (Stage 2); salivary cortisol levels (SCLs) pre-prick (T0) and 20 min post-prick (T1) assessed stress. Preterm infants (n = 64) sampled by convenience at Level III neonatal care units were randomly assigned to the control condition (usual care) or intervention condition (tripartite intervention). Generalized estimating equations examined differences in salivary cortisol between conditions. After adjusting for effects of gestational age, postmenstrual age, and baseline SCLs, (1) at Stage 1, the change in salivary cortisol from T0 to T1 in preterm infants who received the tripartite intervention was, on average, significantly lower by 0.431 units (log scale) than the change in preterm infants who received the control condition (p < 0.001); (2) in the tripartite intervention condition, the difference between the change in mean SCLs from T0 to T1 at Stages 1 and 2 was significantly lower by 0.287 units (log scale), on average than between the change at Stages 1 and 2 in the control condition (p = 0.026). The provision of a tripartite intervention during heel prick significantly decreased the raise of SCLs compared with infants receiving usual care, suggesting lower stress. Clinicians could easily implement the tripartite intervention for heel-stick support; however, replication is needed before recommending its incorporation into routine heel stick and other stressful procedures.

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.

Identifying the Critical Threshold for Long-Term Pediatric Neurological Hospitalizations of the Offspring in Preterm Delivery

We opted to investigate whether a critical threshold exists for long-term pediatric neurological morbidity, and cerebral palsy (CP), in preterm delivery, via a population-based cohort analysis. Four study groups were classified according to their gestational age at birth: 24–27.6, 28–31.6, 32–36.6 weeks and term deliveries, evaluating the incidence of long-term hospitalizations of the offspring due to neurological morbidity. Cox proportional hazard models were performed to control for confounders. A Kaplan–Meier survival curve was used to compare the cumulative neurological morbidity incidence for each group. A total of 220,563 deliveries were included: 0.1% (118) occurred at 24–27.6 weeks of gestation, 0.4% (776) occurred at 28–31.6 weeks of gestation, 6% (13,308) occurred at 32–36.6 weeks of gestation and 93% (206,361) at term. In a Cox model, while adjusting for confounders, delivery before 25 weeks had a 3.9-fold risk for long-term neurological morbidity (adjusted HR (hazard ratio) = 3.9, 95% CI (confidence interval) 2.3–6.6; p < 0.001). The Kaplan–Meier survival curve demonstrated a linear association between long-term neurological morbidity and decreasing gestational age. In a second Cox model, adjusted for confounders, infants born before 25 weeks of gestation had increased rates of CP (adjusted HR = 62.495% CI 25.6–152.4; p < 0.001). In our population, the critical cut-off for long-term neurological complications is delivery before 25 weeks gestation.

The Impact of Oral-Gut Inflammation in Cerebral Palsy

Background: Oral-gut inflammation has an impact on overall health, placing subjects at risk to acquire chronic conditions and infections. Due to neuromotor disturbances, and medication intake, cerebral palsy (CP) subjects present intestinal constipation, impacting their quality of life (QOL). We aimed to investigate how oral inflammatory levels predicted gut phenotypes and response to therapy.

Methods: A total of 93 subjects aging from 5 to 17 years were included in the study, and assigned into one of the 4 groups: CP with constipation (G1, n = 30), CP without constipation (G2, n = 33), and controls without CP with constipation (G3, n = 07) and without CP and without constipation (G4, n = 23). In addition to characterizing subjects' clinical demographics, medication intake, disease severity levels, salivary cytokine levels [TNF-α, interleukin (IL)-1β, IL-6, IL-8, IL-10], and Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD). Statistical significance was evaluated by Shapiro-Wilks, Student's T-Test, ANOVA, and ANCOVA analysis.

Results: Salivary proinflammatory cytokines were highly correlated with the severe form of gut constipation in G1 (P < 0.001), and out of all cytokines IL-1β levels demonstrated highest correlation with all gut constipation (P < 0.05). A significant relationship was found between the type of medication, in which subjects taking Gamma-Aminobutyric Acid (GABA) and GABA+ (GABA in association with other medication) were more likely to be constipated than the other groups (P < 0.01). Cleary salivary inflammatory levels and gut constipation were correlated, and impacted QOL of CP subjects. G1 presented a lower QOL mean score of CPCHILD (49.0 ± 13.1) compared to G2 (71.5 ± 16.7), when compared to G3 (88.9 ± 7.5), and G4 (95.5 ± 5.0) (P < 0.01). We accounted for gingival bleeding as a cofounder of oral inflammation, and here were no differences among groups regarding gender (P = 0.332) and age (P = 0.292).

Conclusions: Collectively, the results suggest that saliva inflammatory levels were linked to gut constipation, and that the clinical impact of medications that controlled gut was reliably monitored via oral cytokine levels, providing reliable and non-invasive information in precision diagnostics.

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.

Genetic predictors of severe intraventricular hemorrhage in extremely low-birthweight infants

OBJECTIVE

To test associations between grades 3 or 4 (severe) intraventricular hemorrhage (IVH) and single nucleotide polymorphisms (SNPs) associated with coagulation, inflammation, angiogenesis, and organ development in an exploratory study.

STUDY DESIGN

Extremely low-birthweight (ELBW) infants enrolled in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network's (NRN) Cytokines Study were included if they had cranial ultrasound (CUS) and genotyping data available in the NRN Anonymized DNA Repository and Database. Associations between SNPs and IVH severity were tested with multivariable logistic regression analysis.

RESULT

One hundred thirty-nine infants with severe IVH and 687 infants with grade 1 or 0 IVH were included. One thousand two hundred seventy-nine SNPs were genotyped. Thirteen were preliminarily associated with severe IVH including five related to central nervous system (CNS) neuronal and neurovascular development.

CONCLUSION

Genetic variants for CNS neuronal and neurovascular development may be associated with severe IVH in premature infants.

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.

Mechanisms of brain injury in newborn infants associated with the fetal inflammatory response syndrome

The fetal inflammatory response syndrome (FIRS) is characterized by umbilical cord inflammation and elevated fetal pro-inflammatory cytokines. Surviving neonates, especially very preterm infants, have increased rates of neonatal morbidity including neurodevelopmental impairment. The mechanism of brain injury in FIRS is complex and may involve "multiple hits." Exposure to in utero inflammation initiates a cascade of the fetal immune response, where pro-inflammatory cytokines can cause direct injury to oligodendrocytes and neurons. Activation of microglia results in further injury to vulnerable pre-myelinating oligodendrocytes and influences the integrity of the fetal and newborn's blood-brain barrier, resulting in further exposure of the brain to developmental insults. Newborns exposed to FIRS are frequently exposed to additional perinatal and postnatal insults that can result in further brain injury. Future directions should include evaluations for new therapeutic interventions aimed at reducing brain injury by dampening FIRS, inhibition of microglial activation, and regeneration of immature oligodendrocytes.

Inflammatory predictors of neurobehavior in very preterm infants

BACKGROUND

Preterm infants are at risk for impaired neurodevelopment. Inflammation may be an important modifiable mediator of preterm birth and neurodevelopmental impairment, but few studies have examined longitudinal measures of inflammation.

OBJECTIVE

To determine the relationship between longitudinal measures of inflammation and neurobehavior in very preterm infants.

STUDY DESIGN

Non-experimental, repeated measures cohort study.

METHODS

Very preterm infants were enrolled between October 2017 and December 2018. Blood was collected weekly until 35 weeks post-menstrual age for the quantification of plasma cytokines. Neurobehavior was assessed at 35 weeks post-menstrual age using the cluster scores for motor development and vigor and alertness/orientation from the Neurobehavioral Assessment of the Preterm Infant. Multiple linear regression models with robust standard errors were used to analyze the data. Average levels of individual cytokines, cytokine trends, and composite scores were used as measures of inflammation.

RESULTS

Seventy-three infants were enrolled in the study. Interleukin-1 receptor antagonist was associated with motor development and vigor scores. Interleukin-6 was associated with alertness/orientation scores. Tumor necrosis factor-alpha and composite scores of inflammation were associated with motor development and vigor and alertness/orientation scores. There were interactions with post-menstrual age at birth and infant sex.

CONCLUSION

Inflammation may be an important predictor of short-term neurobehavior in preterm infants. Interleukin-1 receptor antagonist, interleukin-6, and tumor necrosis factor-alpha are key cytokines for studies of preterm infants, but composite scores may be a better measure of inflammation than individual cytokines. Inflammation can be damaging to the immature brain and may be a specific target for future interventions to improve outcomes.

Genetic variation in dopamine neurotransmission and motor development of infants born extremely-low-birthweight

AIM

To determine if genetic variation associated with decreased dopamine neurotransmission predicts a decrease in motor development in a convenience cohort study of infants born extremely-low-birthweight (ELBW).

METHOD

Four hundred and ninety-eight infants born ELBW had genome-wide genotyping and a neurodevelopmental evaluation at 18 to 22 months of age, corrected for preterm birth. A polygenic risk score (PRS) was created to combine into one predictor variable the hypothesized influences on motor development of alleles at seven independent single nucleotide polymorphisms previously associated with relative decreases in both dopamine neurotransmission and motor learning, by summing the number of alleles present in each infant (range=0-14). The motor development outcome was the Psychomotor Development Index (PDI) of the Bayley Scales of Infant Development, Second Edition. The linear regression models were adjusted for seven clinical and four genetic ancestry covariates. The mean PRS of infants with cerebral palsy (CP) was compared to those without CP.

RESULTS

PRS was inversely related to PDI (p=0.011). Each 1-point increase in PRS resulted in an average decrease in PDI of 1.37 points. Patients with CP did not have a greater mean PRS than those without (p=0.67), both with and without adjustment for covariates.

INTERPRETATION

Genetic variation that favors a decrease in dopamine neurotransmission predisposes to a decrease in motor development in infants born ELBW, but not to the diagnosis of CP.

WHAT THIS PAPER ADDS

Genetic variation in dopamine neurotransmission was associated with a decrease in motor development in infants born at an extremely-low-birthweight. It does not predispose to the diagnosis of cerebral palsy.

Genetic and epigenetic factors and early life inflammation as predictors of neurodevelopmental outcomes

Among individuals born very preterm, perinatal inflammation, particularly if sustained or recurring, is highly likely to contribute to adverse neurodevelopmental outcomes, including cerebral white matter damage, cerebral palsy, cognitive impairment, attention-deficit/hyperactivity disorder, and autism spectrum disorder. Antecedents and correlates of perinatal inflammation include socioeconomic disadvantage, maternal obesity, maternal infections, fetal growth restriction, neonatal sepsis, necrotizing enterocolitis, and prolonged mechanical ventilation. Genetic factors can modify susceptibility to perinatal inflammation and to neurodevelopmental disorders. Preliminary evidence supports a role of epigenetic markers as potential mediators of the presumed effects of preterm birth and/or its consequences on neurodevelopment later in life. Further study is needed of factors such as sex, psychosocial stressors, and environmental exposures that could modify the relationship of early life inflammation to later neurodevelopmental impairments. Also needed are pharmacological and non-pharmacological interventions to attenuate inflammation towards the goal of improving the neurodevelopment of individuals born very preterm.

Advances in cerebral palsy biomarkers

Cerebral palsy (CP), defined as a group of nonprogressive disorders of movement and posture, is the most common cause of severe neurodisability in children. The prevalence of CP is the same across the globe, affecting approximately 17 million people worldwide. Cerebral Palsy is an umbrella term used to describe the disease due to its inherent heterogeneity. For instance, CP has multiple (1) causes; (2) clinical types; (3) patterns of neuropathology on brain imaging and (4) it's associated with several developmental pathologies such as intellectual disability, autism, epilepsy, and visual impairment. Understanding its physiopathology is crucial to developing protective strategies. Despite its importance, there is still insufficient progress in the areas of CP prediction, early diagnosis, treatment, and prevention. Herein we describe the current risk factors and biomarkers used for the diagnosis and prediction of CP. With the advancement in biomarker discovery, we predict that our understanding of the etiopathophysiology of CP will also increase, lending to more opportunities for developing novel treatments and prognosis.

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 Exploratory Examination of Neonatal Cytokines and Chemokines as Predictors of Autism Risk: The Early Markers for Autism Study

BACKGROUND

The identification of an early biomarker for autism spectrum disorder (ASD) would improve the determination of risk, leading to earlier diagnosis and, potentially, earlier intervention and improved outcomes.

METHODS

Data were generated from the Early Markers for Autism study, a population-based case-control study of prenatal and neonatal biomarkers of ASD. Newborn bloodspots of children with ASD (n = 370), children with developmental delay (n = 140), and general population (GP) controls (n = 378) were analyzed for 42 different immune markers using a Luminex multiplex platform. Comparisons of immune marker concentrations between groups were examined using logistic regression and partial least squares discriminant analysis.

RESULTS

Children with ASD had significantly increased neonatal levels of interleukin-6 (IL-6) and IL-8 compared with GP controls. An increase in IL-8 was especially significant in the ASD group with early onset compared with the GP group, with an adjusted odds ratio of 1.97 (95% confidence interval, 1.39-2.83; p = .00014). In addition, children with ASD had significantly elevated levels of eotaxin-1, interferon-γ, and IL-12p70 relative to children with developmental delay. We observed no significant differences in levels of immune markers between the developmental delay and GP groups.

CONCLUSIONS

Elevated levels of some inflammatory markers in newborn bloodspots indicated a higher degree of immune activation at birth in children who were subsequently diagnosed with ASD. The data from this exploratory study suggest that with further expansion, the development of neonatal bloodspot testing for cytokine/chemokine levels might lead to the identification of biomarkers that provide an accurate assessment of ASD risk at birth.

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.

Association between high levels of inflammatory markers and cognitive outcomes at 4 years of age: The Rhea mother-child cohort study, Crete, Greece

There is growing evidence associating inflammatory markers in complex, higher order neurological functions, such as cognition and memory. We examined whether high levels of various inflammatory markers are associated with cognitive outcomes at 4 years of age in a mother-child cohort in Crete, Greece (Rhea study). We included 642 children in this cross-sectional study. Levels of several inflammatory markers (IFN-γ, IL-1β, IL-6, IL-8, IL-17α, IL-10, MIP-1α, TNF-α and the ratios of IL-6 to IL-10 and TNF-α to IL-10) were determined in child serum via immunoassay. Neurodevelopment at 4 years was assessed by means of the McCarthy Scales of Children's Abilities. Multivariate linear regression analyses were used to estimate the associations between the exposures and outcomes of interest after adjustment for various confounders. Our results indicate that children with high TNF-α concentrations (≥90th percentile) in serum demonstrated decreased scores in memory (adjusted β = -4.0; 95% CI: -7.7, -0.2), working memory (adjusted β = -4.0; 95% CI: -8.0, -0.1) as well as in memory span scale (adjusted β = -4.0; 95% CI: -7.9, -0.1). We also found that children with high IFN-γ serum levels showed lower scores in memory span scale (adjusted β = -3.4; 95% CI: -7.3, -0.4). Children with elevated TNF-α/IL-10 ratio demonstrated decreased quantitative (adjusted β = -4.3; 95% CI: -8.2, -0.4), motor (adjusted β = -3.5; 95% CI: -7.5, -0.5), executive function (adjusted β = -4.8; 95% CI: -8.5, -1.1), general cognitive (adjusted β = -3.6; 95% CI: -7.3, -0.1), memory (adjusted β = -3.8; 95% CI: -7.6, -0), working memory (adjusted β = -3.5; 95% CI: -7.5, -0.5) and memory span scores (adjusted β = -5.3; 95% CI: -9.1, -1.4) The findings suggest that high levels of TNF-α may contribute to reduced memory performance at preschool age.

Genetic variants associated with patent ductus arteriosus in extremely preterm infants

OBJECTIVE

Patent ductus arteriosus (PDA) is a commonly observed condition in preterm infants. Prior studies have suggested a role for genetics in determining spontaneous ductal closure. Using samples from a large neonatal cohort we tested the hypothesis that common genetic variations are associated with PDA in extremely preterm infants.

STUDY DESIGN

Preterm infants (n = 1013) enrolled at NICHD Neonatal Research Network sites were phenotyped for PDA. DNA was genotyped for 1634 single nucleotide polymorphisms (SNPs) from candidate genes. Analyses were adjusted for ancestral eigenvalues and significant epidemiologic variables.

RESULTS

SNPs in several genes were associated with the clinical diagnosis of PDA and with surgical ligation in extremely preterm neonates diagnosed with PDA (p < 0.01). None of the associations were significant after correction for multiple comparisons.

CONCLUSION

We identified several common genetic variants associated with PDA. These findings may inform further studies on genetic risk factors for PDA in preterm infants.

A rat model to study maternal depression during pregnancy and postpartum periods, its comorbidity with cardiovascular diseases and neurodevelopmental impact in the offspring

This study aimed to develop an animal model of human depression during pregnancy and lactation to examine the effect of maternal, perinatal depression on offspring development. Maternal depression during pregnancy affects up to 20% of women and is a risk factor for both the developmental and long-term health issues. It is often comorbid with the cardiovascular disease (CVD) that affects the uteroplacental circulation and impacts offspring development. More than half of the expecting mothers with depression use antidepressants that cross the placenta and may interfere with the neurodevelopmental programming. Thus, depressed pregnant mothers face a difficult choice whether "to use or not to use" antidepressant therapy, since both untreated depression and antenatal antidepressant exposure present increased risks of neurodevelopmental pathologies. The ongoing clinical debate presents inconclusive data, while the existing animal models of maternal depression do not include early gestational periods, and, do not monitor depressive-like behavior nor address the cardiovascular abnormalities. The presented model includes pregestational depressive behavior extending into pregnancy and lactation, periods that have not been previously examined. Rat dams exposed to pre-gestational chronic mild stress (CMS) developed a sustained decrease in self-grooming behavior, correlated with hormonal, behavioral, and cardiac changes persisting through the postpartum period. Preliminary data indicate neurodevelopmental delays, behavioral and cardiac abnormalities, and altered levels of both the brain and the heart markers in the offspring of stressed dams. Furthermore, the preliminary data predict that maternal pregnancy during the perinatal period is likely to impact the neurodevelopmental process in a sex-dependent manner. Thus the presented here model (PG-LAC CMS) fulfills both the face and the construct validity criteria for maternal stress-induced depression during pregnancy and postpartum that may facilitate further studies of the relative risks of untreated vs. antidepressant-treated maternal depression during pregnancy to the mother and her offspring.

Persistent pulmonary hypertension of the newborn in extremely preterm infants: a Japanese cohort study

OBJECTIVE

To investigate the characteristics of persistent pulmonary hypertension of the newborn (PPHN) in extremely preterm infants and its impact on neurodevelopmental outcomes at 3 years of age.

DESIGN

A retrospective multicentre cohort study.

SETTINGS

202 tertiary perinatal centres registered in the Neonatal Research Network of Japan (NRNJ).

PATIENTS

Infants born at <28 weeks of gestational age (GA), between 2003 and 2012, were extracted from tertiary perinatal centres participating in NRNJ.

MAIN OUTCOME MEASURES

Demographic characteristics, morbidity, interventions and mortality were compared for infants with and without PPHN. Multivariable logistic analysis was performed to evaluate the impact of PPHN on long-term neurodevelopmental outcomes (the prevalence rate of cerebral palsy, need for home oxygen therapy, and visual, hearing and cognitive impairment) at 3 years of age.

RESULTS

The prevalence of PPHN among the 12 954 extremely preterm infants enrolled was 8.1% (95% CI 7.7% to 8.6%), with the trend increasing annually, and a higher proportion as GA decreased: 18.5% (range, 15.2% to 22.4%) for infants born at 22 weeks compared with 4.4% (range, 3.8% to 5.2%) for those born at 27 weeks. Clinical chorioamnionitis and premature rupture of membranes were associated with PPHN. On multivariate analysis of the data from 5923 infants followed up for 3 years, PPHN was a significant independent risk factor for visual impairment (adjusted OR, 1.42, 95% CI 1.03 to 1.97).

CONCLUSIONS

The prevalence of PPHN in extremely preterm infants has been increasing over the past decade in Japan. Clinicians should be aware of visual impairments as a neurodevelopmental abnormality among infants with PPHN.

The Cerebrospinal Fluid Inflammatory Response to Preterm Birth

Background: Preterm birth is the leading risk factor for perinatal white matter injury, which can lead to motor and neuropsychiatric impairment across the life course. There is an unmet clinical need for therapeutics. White matter injury is associated with an altered inflammatory response in the brain, primarily led by microglia, and subsequent hypomyelination. However, microglia can release both damaging and trophic factors in response to injury, and a comprehensive assessment of these factors in the preterm central nervous system (CNS) has not been carried out.

Method: A custom antibody array was used to assess relative levels of 50 inflammation- and myelination-associated proteins in the cerebrospinal fluid (CSF) of preterm infants in comparison to term controls.

Results: Fifteen proteins differed between the groups: BDNF, BTC, C5a, FasL, Follistatin, IL-1β, IL-2, IL-4, IL-9, IL-17A, MIP-1α, MMP8, SPP1, TGFβ, and TNFβ (p < 0.05). To investigate the temporal regulation of these proteins after injury, we mined a gene expression dataset of microglia isolated from a mouse model of developmental white matter injury. Microglia in the experimental model showed dynamic temporal expression of genes encoding these proteins, with an initial and sustained pro-inflammatory response followed by a delayed anti-inflammatory response, and a continuous expression of genes predicted to inhibit healthy myelination.

Conclusion: Preterm CSF shows a distinct neuroinflammatory profile compared to term controls, suggestive of a complex neural environment with concurrent damaging and reparative signals. We propose that limitation of pro-inflammatory responses, which occur early after perinatal insult, may prevent expression of myelination-suppressive genes and support healthy white matter development.

The complex aetiology of cerebral palsy

Cerebral palsy (CP) is the most prevalent, severe and costly motor disability of childhood. Consequently, CP is a public health priority for prevention, but its aetiology has proved complex. In this Review, we summarize the evidence for a decline in the birth prevalence of CP in some high-income nations, describe the epidemiological evidence for risk factors, such as preterm delivery and fetal growth restriction, genetics, pregnancy infection and other exposures, and discuss the success achieved so far in prevention through the use of magnesium sulfate in preterm labour and therapeutic hypothermia for birth-asphyxiated infants. We also consider the complexities of disentangling prenatal and perinatal influences, and of establishing subtypes of the disorder, with a view to accelerating the translation of evidence into the development of strategies for the prevention of CP.

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.

Necrotizing Enterocolitis and Neurodevelopmental Outcome

Necrotizing enterocolitis is a serious complication of prematurity that is associated with an increased risk for adverse neurodevelopmental outcome secondary to a complex relationship between various morbidities that increase the risk for central nervous system injury. Affected infants are exposed to a variety of circulating cytokines known to be associated with white matter injury. These infants also have an increased risk of secondary blood stream infections and nutritional compromise.

Chorioamnionitis, neuroinflammation, and injury: timing is key in the preterm ovine fetus

Background

Antenatal infection (i.e., chorioamnionitis) is an important risk factor for adverse neurodevelopmental outcomes after preterm birth. Destructive and developmental disturbances of the white matter are hallmarks of preterm brain injury. Understanding the temporal effects of antenatal infection in relation to the onset of neurological injury is crucial for the development of neurotherapeutics for preterm infants. However, these dynamics remain unstudied.

Methods

Time-mated ewes were intra-amniotically injected with lipopolysaccharide at 5, 12, or 24 h or 2, 4, 8, or 15 days before preterm delivery at 125 days gestational age (term ~ 150 days). Post mortem analyses for peripheral immune activation, neuroinflammation, and white matter/neuronal injury were performed. Moreover, considering the neuroprotective potential of erythropoietin (EPO) for perinatal brain injury, we evaluated (phosphorylated) EPO receptor (pEPOR) expression in the fetal brain following LPS exposure.

Results

Intra-amniotic exposure to this single bolus of LPS resulted in a biphasic systemic IL-6 and IL-8 response. In the developing brain, intra-amniotic LPS exposure induces a persistent microgliosis (IBA-1 immunoreactivity) but a shorter-lived increase in the pro-inflammatory marker COX-2. Cell death (caspase-3 immunoreactivity) was only observed when LPS exposure was greater than 8 days in the white matter, and there was a reduction in the number of (pre) oligodendrocytes (Olig2- and PDGFRα-positive cells) within the white matter at 15 days post LPS exposure only. pEPOR expression displayed a striking biphasic regulation following LPS exposure which may help explain contradicting results among clinical trials that tested EPO for the prevention of preterm brain injury.

Conclusion

We provide increased understanding of the spatiotemporal pathophysiological changes in the preterm brain following intra-amniotic inflammation which may aid development of new interventions or implement interventions more effectively to prevent perinatal brain damage.

Chorioamnionitis, IL-17A, and fetal origins of neurologic disease

The Centers for Disease Control and Prevention estimate that 1 in 323 infants have cerebral palsy. Highly correlated to intrauterine infection and inflammation, the incidence of cerebral palsy has remained constant over the last few decades despite significant advances in neonatal intensive care including improved ventilator techniques, surfactant therapy, maternal steroid administration, and use of intrapartum empiric antimicrobials. Recent advances in our understanding of immune responses to infection and inflammation have identified the cytokine IL-17A as a crucial component of early proinflammatory mediators that cause brain injury associated with neurologic impairment. Remarkably, maternal inflammatory responses to in utero inflammation and infection can also lead to potentially debilitating neurologic conditions in the offspring, which often become clinically apparent during childhood and/or early adulthood. This review details the role of IL-17A in fetal and maternal proinflammatory responses that lead to fetal brain injury and neurologic sequelae, including cerebral palsy. Recent findings regarding the role of maternal inflammatory responses in the development of childhood and adult neurologic conditions, such as autism, schizophrenia, and multiple sclerosis, will also be highlighted.

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.

Urinary Levels of IL-1β and GDNF in Preterm Neonates as Potential Biomarkers of Motor Development: A Prospective Study

Objectives. To evaluate the association between inflammatory biomarkers, neurotrophic factors, birth conditions, and the presence of motor development abnormalities in preterm neonates. Methods. Plasma and urinary levels of cytokines (IL-1β, IL-6, IL-10, TNF, and IL-12p70), chemokines (CXCL8/IL-8, CCL2/MCP-1, CCL5/RANTES, CXCL10/IP-10, and CXCL9/MIG), and neurotrophic factors (BDNF and GDNF) were evaluated in 40 preterm neonates born between 28 and 32 incomplete weeks of gestation, at four distinct time points: at birth (umbilical cord blood) (T0), at 48 (T1), at 72 hours (T2), and at 3 weeks after birth (T3). Biomarkers levels were compared between different time points and then associated with Test of Infant Motor Performance (TIMP) percentiles. Results. Maternal age, plasma, and urinary concentrations of inflammatory molecules and neurotrophic factors were significantly different between groups with normal versus lower than expected motor development. Higher levels of GDNF were found in the group with lower than expected motor development, while IL-1β and CXCL8/IL-8 values were higher in the group with typical motor development. Conclusion. Measurements of cytokines and neurotrophic factors in spot urine may be useful in the follow-up of motor development in preterm neonates.

Postnatal systemic inflammation and neuro-ophthalmologic dysfunctions in extremely low gestational age children

AIM

Compared to infants born at term, children born very preterm are at increased risk of visual dysfunctions and neonatal systemic inflammation. Here, we explore whether these two propensities are related.

METHODS

As part of the ELGAN study, the concentrations of 16 mediators of inflammation were measured in blood obtained on postnatal days 1, 7, 14, 21 and 28 from 1062 children born before the 28th week of gestation. Presence of visual field deficit, strabismus and/or impaired visual fixation was recorded at age two. The concentrations of each protein were divided into quartiles within gestational week categories. We calculated odds ratios with 99% confidence intervals for having each disorder comparing children with concentration in the top quartile of each protein to children whose concentration was in the lower quartiles on the corresponding day. Analyses were adjusted for gestational age and birth weight Z-score.

RESULTS

Only one of 80 assessments (16 proteins on five different days) was significant for visual field deficit, and one for impaired fixation. No association was found between strabismus and any inflammatory mediator.

CONCLUSION

None of the three neuro-ophthalmologic dysfunctions assessed at two years appears to be associated with systemic inflammation measured the first four postnatal weeks.

Cytokines and growth factors in the developing intestine and during necrotizing enterocolitis

Cytokines and growth factors play diverse roles in the uninflamed fetal/neonatal intestinal mucosa and in the development of inflammatory bowel injury during necrotizing enterocolitis (NEC). During gestational development and the early neonatal period, the fetal/premature intestine is exposed to high levels of many "inflammatory" cytokines and growth factors, first via swallowed amniotic fluid in utero and then, after birth, in colostrum and mother's milk. This article reviews the dual, seemingly counter-intuitive roles of cytokines, where these agents play a "trophic" role and promote maturation of the uninflamed mucosa, but can also cause inflammation and promote intestinal injury during NEC.

Circulating Inflammatory-Associated Proteins in the First Month of Life and Cognitive Impairment at Age 10 Years in Children Born Extremely Preterm

OBJECTIVES

To evaluate whether in children born extremely preterm, indicators of sustained systemic inflammation in the first month of life are associated with cognitive impairment at school age.

STUDY DESIGN

A total of 873 of 966 eligible children previously enrolled in the multicenter Extremely Low Gestational Age Newborn Study from 2002 to 2004 were evaluated at age 10 years. We analyzed the relationship between elevated blood concentrations of inflammation-associated proteins in the first 2 weeks ("early elevations"; n = 812) and the third and fourth week ("late elevations"; n = 532) of life with neurocognition.

RESULTS

Early elevations of C-reactive protein, tumor necrosis factor-α, interleukin (IL)-8, intercellular adhesion molecule (ICAM)-1, and erythropoietin were associated with IQ values >2 SD below the expected mean (ORs: 2.0-2.3) and with moderate to severe cognitive impairment on a composite measure of IQ and executive function (ORs: 2.1-3.6). Additionally, severe cognitive impairment was associated with late protein elevations of C-reactive protein (OR: 4.0; 95% CI 1.5, 10), IL-8 (OR: 5.0; 1.9, 13), ICAM-1 (OR: 6.5; 2.6, 16), vascular endothelial growth factor-receptor 2 (OR: 3.2; 1.2, 8.3), and thyroid-stimulating hormone (OR: 3.1; 1.3, 7.3). Moderate cognitive impairment was most strongly associated with elevations of IL-8, ICAM-1, and vascular endothelial growth factor-receptor 2. When 4 or more inflammatory proteins were elevated early, the risk of having an IQ <70 and having overall impaired cognitive ability was more than doubled (ORs: 2.1-2.4); the presence of 4 or more inflammatory protein elevated late was strongly linked to adverse cognitive outcomes (ORs: 2.9-4.8).

CONCLUSIONS

Extremely preterm children who had sustained elevations of inflammation-related proteins in the first postnatal month are more likely than extremely preterm peers without such elevations to have cognitive impairment at 10 years.

Prevention and management of bronchopulmonary dysplasia: Lessons learned from the neonatal research network

Despite remarkable improvements in survival of extremely premature infants, the burden of BPD among survivors remains a frustrating problem for parents and caregivers. Advances, such as antenatal steroids and surfactant replacement, which have dramatically improved survival, have not reduced BPD among survivors. Other advances that have significantly improved the combined outcome of death or BPD, such as vitamin A and avoidance of mechanical ventilation, have had smaller magnitude effects on the outcome of BPD alone. Postnatal steroids have a clear beneficial effect on BPD, but the optimal preparation, dose, and timing for maximizing benefit and minimizing harm have yet to be determined. This persistent burden of BPD among the most immature survivors remains a challenge for the NRN and other researchers in neonatal medicine.

Neurodevelopment of Preterm Infants at 24 Months After Neonatal Supplementation of a Prebiotic Mix: A Randomized Trial

OBJECTIVES

Fetal brain maturation is disrupted by preterm birth. Inflammation during the neonatal period may further harm neurodevelopmental outcomes. The present study aimed to determine the effect of short-chain galacto-oligosaccharides/long-chain fructo-oligosaccharides/pectin-derived acidic oligosaccharides (scGOS/lcFOS/pAOS) on neurodevelopmental outcomes measured by Bayley Scales of Infant and Toddler Development in preterm infants at 24 months.

METHODS

In this randomized controlled trial, scGOS/lcFOS/pAOS or placebo was supplemented between days 3 and 30 of life. Serum samples at day 1, 7, and 14 were analyzed for cytokine levels. Stool samples at day 1, 7, 14, and 30 were measured for bacterial count and bifidobacteria percentage. At 24 months corrected age infants were followed up by a blinded pediatric psychologist for the Bayley Scales of Infant and Toddler Development II or III.

RESULTS

Seventy-seven of one hundred one (76%) eligible infants participated in the follow-up study. Neurodevelopmental outcomes were not different in the scGOS/lcFOS/pAOS and placebo group. Infections during the neonatal period, lower percentages of bifidobacteria at day 7 (F = 3.8, P = 0.05) and day 14 (F = 5.0, P = 0.02) and higher levels of Interleukine (IL)-1β (F = 4.0, P = 0.04) and IL-8 (F = 8.0, P = 0.01) at day 7 are associated with lower mental developmental index. Lower psychomotor outcomes are associated with IL-2 (F = 4.0, P = 0.05), IL-4 (F = 6.0, P = 0.02) at birth, and interferon gamma at day 7 (F = 4.4, P = 0.04).

CONCLUSIONS

scGOS/lcFOS/pAOS showed no significant improvement of neurodevelopmental outcomes at 24 months in preterm infants. Infections, lower bifidobacteria counts, and higher serum cytokine levels during the neonatal period were associated with lower neurodevelopmental outcomes at 24 months of age indicating the relevance of microbiome and immune responses in neurodevelopmental processes.

Blood Cytokine Profiles Associated with Distinct Patterns of Bronchopulmonary Dysplasia among Extremely Low Birth Weight Infants

OBJECTIVE

To explore differences in blood cytokine profiles among distinct bronchopulmonary dysplasia (BPD) patterns.

STUDY DESIGN

We evaluated blood spots collected from 943 infants born at ≤1000 g and surviving to 28 days on postnatal days 1, 3, 7, 14, and 21 for 25 cytokines. Infants were assigned to the following lung disease patterns: (1) no lung disease (NLD); (2) respiratory distress syndrome without BPD; (3) classic BPD (persistent exposure to supplemental oxygen until 28 days of age); or (4) atypical BPD (period without supplemental oxygen before 28 days). Median cytokine levels for infants with BPD were compared with the IQR of results among infants with NLD.

RESULTS

The distribution of enrolled infants by group was as follows: 69 (NLD), 73 (respiratory distress syndrome), 381 (classic BPD), and 160 (atypical BPD). The remaining 260 infants could not be classified because of missing data (104) or not fitting a predefined pattern (156). Median levels of 3 cytokines (elevated interleukin [IL]-8, matrix metalloproteinase-9; decreased granulocyte macrophage colony-stimulating factor) fell outside the IQR for at least 2 time points in both infants with atypical and classic BPD. Profiles of 7 cytokines (IL-6, IL-10, IL-18, macrophage inflammatory protein-1α, C-reactive protein, brain-derived neurotrophic factor, regulated on activation, normal T cell expressed and secreted) differed between infants with classic and atypical BPD.

CONCLUSIONS

Blood cytokine profiles may differ between infants developing classic and atypical BPD. These dissimilarities suggest the possibility that differing mechanisms could explain the varied patterns of pathophysiology of lung disease in extremely premature infants.