Evaluation of Postoperative Outcomes After Enterostomy Closure in Low Body Weight Infants: A Multi-Center Retrospective Analysis.

BACKGROUND: The minimum weight for enterostomy closure (EC) in infants remains debated with the current acceptable cut-off of >2 kg. As enterostomy-related complications or high enterostomy output (>30cc/kg/d) may prohibit a premature infant from reaching 2 kg, additional data is needed to evaluate the safety of EC in infants <2 kg. The objective of this study was to evaluate postoperative outcomes in low body weight (<2 kg) infants undergoing EC compared to larger infants. METHODS: We performed a multi-center retrospective analysis from 1/1/2012-12/31/2022 of all infants (age <1 year) who were <4 kg at time of EC. Primary outcomes included postoperative complications and 30-day mortality. Non-parametric analysis was performed using the Kruskal-Wallis one-way analysis of variance and chi-square tests. Univariable logistic regression was performed to identify factors associated with postoperative complications. RESULTS: Of 92 infants, 15 infants (16.3%) underwent EC at <2 kg, 16 (17.4%) at 2-2.49 kg, 31 (33.7%) at 2.5-2.99 kg, and 30 (32.6%) at ≥3 kg. Infants <2 kg at time of EC exhibited higher rates of hyperbilirubinemia (P = .030), neurologic comorbidities (P = .030), and high enterostomy output (P = .041). There was no difference in postoperative complications (P = .460) or 30-day mortality (P = .460) between the <2 kg group and larger weight groups. Low body weight was not associated with an increased risk for developing a postoperative complication (OR: 1.001, 95% CI: 1.001-1.001; P = .032). CONCLUSION: Our findings suggest that EC in infants <2 kg may be safe with comparable postoperative outcomes to larger weight infants. Thus, the timing of EC should be based on the infant's physiologic status, in contrast to a predetermined minimum weight cut-off.

Epigenome-wide analysis identifies genes and pathways linked to acoustic cry variation in preterm infants.

BACKGROUND: Preterm birth places infants at higher risk of adverse long-term behavioral and cognitive outcomes. Combining biobehavioral measures and molecular biomarkers may improve tools to predict the risk of long-term developmental delays. METHODS: The Neonatal Neurobehavior and Outcomes in Very Preterm Infants study was conducted at nine neonatal intensive care units between April 2014 and June 2016. Cries were recorded and buccal swabs collected during the neurobehavioral exam. Cry episodes were extracted and analyzed using a computer system and the data were summarized using factor analysis. Genomic DNA was extracted from buccal swabs, quantified using the Qubit Fluorometer, and aliquoted into standardized concentrations. DNA methylation was measured with the Illumina MethylationEPIC BeadArray, and an epigenome-wide association study was performed using cry factors (n = 335). RESULTS: Eighteen CpGs were associated with the cry factors at genome-wide significance (α = 7.08E - 09). Two CpG sites, one intergenic and one linked to gene TCF3 (important for B and T lymphocyte development), were associated with acoustic measures of cry energy. Increased methylation of TCF3 was associated with a lower energy-related cry factor. We also found that pitch (F0) and hyperpitch (F0 > 1 kHz) were associated with DNA methylation variability at 16 CpG sites. CONCLUSIONS: Acoustic cry characteristics are related to variation in DNA methylation in preterm infants. IMPACT: Preterm birth is a major public health problem and its long-term impact on health is not well understood. Cry acoustics, related to prematurity, has been linked to a variety of medical conditions. Biobehavioral measures and molecular biomarkers can improve prediction tools for long-term developmental risks of preterm birth. Variation in epigenetic modulation in preterm infants provides a potential link between preterm birth and unfavorable developmental outcomes.

Serious neonatal morbidities are associated with differences in DNA methylation among very preterm infants.

BACKGROUND: Infants born very preterm are more likely to experience neonatal morbidities compared to their term peers. Variations in DNA methylation (DNAm) associated with these morbidities may yield novel information about the processes impacted by these morbidities. METHODS: This study included 532 infants born < 30 weeks gestation, participating in the Neonatal Neurobehavior and Outcomes in Very Preterm Infants study. We used a neonatal morbidity risk score, which was an additive index of the number of morbidities experienced during the NICU stay, including bronchopulmonary dysplasia (BPD), severe brain injury, serious neonatal infections, and severe retinopathy of prematurity. DNA was collected from buccal cells at discharge from the NICU, and DNAm was measured using the Illumina MethylationEPIC. We tested for differential methylation in association with the neonatal morbidity risk score then tested for differentially methylated regions (DMRs) and overrepresentation of biological pathways. RESULTS: We identified ten differentially methylated CpGs (α Bonferroni-adjusted for 706,278 tests) that were associated with increasing neonatal morbidity risk scores at three intergenic regions and at HPS4, SRRD, FGFR1OP, TNS3, TMEM266, LRRC3B, ZNF780A, and TENM2. These mostly followed dose-response patterns, for 8 CpGs increasing DNAm associated with increased numbers of morbidities, while for 2 CpGs the risk score was associated with decreasing DNAm. BPD was the most substantial contributor to differential methylation. We also identified seven potential DMRs and over-representation of genes involved in Wnt signaling; however, these results were not significant after Bonferroni adjustment for multiple testing. CONCLUSIONS: Neonatal DNAm, within genes involved in fibroblast growth factor activities, cellular invasion and migration, and neuronal signaling and development, are sensitive to the neonatal health complications of prematurity. We hypothesize that these epigenetic features may be representative of an integrated marker of neonatal health and development and are promising candidates to integrate with clinical information for studying developmental impairments in childhood.

Sociodemographic and medical influences on neurobehavioral patterns in preterm infants: A multi-center study.

BACKGROUND: Among preterm infants, neurodevelopmental outcomes are influenced by both medical and sociodemographic factors. Less is known about the impact on these factors on neonatal neurobehavioral patterns. OBJECTIVE: To determine associations between demographic, psychosocial and medical risk factors and neonatal neurobehavior. METHODS: Multi-center observational study of infants born <30 weeks enrolled in the Neonatal Neurobehavior and Outcomes in Very Preterm Infants (NOVI) Study between April 2014-May 2016. Maternal medical, demographic, and psychological variables and infant medical variables were prospectively collected. Demographic, substance, psychological and medical risk indices were developed. Neurobehavioral assessment was performed using the NICU Network Neurobehavioral Scale (NNNS) at NICU discharge. RESULTS: 709 infants were enrolled in the NOVI study, and for 679 infants with neurobehavioral assessments, 6 NNNS behavioral profiles were calculated using latent profile analysis. Profile 6 infants (n = 47/679, 7%) were atypical, having poor attention, self-regulation and movement quality, hypertonia and increased stress signs. After adjustment for site, profile 6 infants had significantly smaller head circumferences at birth (ß -0.87; -1.59, -0.14), and higher rates of late sepsis (OR 3.38; CI 1.66, 6.92) compared to Profiles 1-5 infants. There were no significant differences in other neonatal morbidities between the two groups. Profile 6 infants had a higher prenatal demographic risk score (1.46 vs 1.07;ß 0.34; CI 0.06, 0.61) compared to Profiles 1-5 infants. CONCLUSION: NNNS behavioral profiles identify an atypical behavioral pattern that is associated with early influences of demographic and medical variables. Such behavioral patterns may be seen as early as NICU discharge.

Body composition and neuromotor development in the year after NICU discharge in premature infants.

BACKGROUND: Hypothesis: neuromotor development correlates to body composition over the first year of life in prematurely born infants and can be influenced by enhancing motor activity. METHODS: Forty-six female and 53 male infants [27 ± 1.8 (sd) weeks] randomized to comparison or exercise group (caregiver provided 15-20 min daily of developmentally appropriate motor activities) completed the year-long study. Body composition [lean body and fat mass (LBM, FM)], growth/inflammation predictive biomarkers, and Alberta Infant Motor Scale (AIMS) were assessed. RESULTS: AIMS at 1 year correlated with LBM (r = 0.32, p < 0.001) in the whole cohort. However, there was no effect of the intervention. LBM increased by ~3685 g (p < 0.001)); insulin-like growth factor-1 (IGF-1) was correlated with LBM (r = 0.36, p = 0.002). IL-1RA (an inflammatory biomarker) decreased (-75%, p < 0.0125). LBM and bone mineral density were significantly lower and IGF-1 higher in the females at 1 year. CONCLUSIONS: We found an association between neuromotor development and LBM suggesting that motor activity may influence LBM. Our particular intervention was ineffective. Whether activities provided largely by caregivers to enhance motor activity in prematurely born infants can affect the interrelated (1) balance of growth and inflammation mediators, (2) neuromotor development, (3) sexual dimorphism, and/or (4) body composition early in life remains unknown.

Psychosocial and medical adversity associated with neonatal neurobehavior in infants born before 30 weeks gestation.

BACKGROUND: Psychosocial adversity escalates medical risk for poor outcomes in infants born <30 weeks gestation. Neonatal neurobehavior and maternal psychological and socioenvironmental assessments may identify the earliest specific intervention needs. We hypothesized that maternal prenatal anxiety, depression, and adverse medical and socioenvironmental conditions would be associated with less optimal neonatal neurobehavior at neonatal intensive care unit (NICU) discharge. METHODS: We studied 665 infants at 9 university NICUs. Risk indices of socioenvironmental, maternal, and neonatal medical factors were obtained from standardized, structured maternal interviews and medical record reviews. Brain injuries were classified by consensus ultrasonogram readings. NICU Network Neurobehavioral Scale (NNNS) exams were conducted at NICU discharge. RESULTS: On the NNNS, generalized estimating equations indicated infants of mothers with prenatal anxiety had less optimal attention, and those born to mothers with prenatal depression had increased lethargy. Maternal medical complications predicted suboptimal reflexes. Socioenvironmental risk predicted lower self-regulation and movement quality. Infants with more severe neonatal medical complications had lower attention, increased lethargy, and suboptimal reflexes. CONCLUSIONS: Combined information from the observed associations among adverse prenatal maternal medical and psychosocial conditions, and neonatal complications may assist in the early identification of infants at elevated neurobehavioral risk.

Epigenome-wide Analysis Identifies Genes and Pathways Linked to Neurobehavioral Variation in Preterm Infants.

Neonatal molecular biomarkers of neurobehavioral responses (measures of brain-behavior relationships), when combined with neurobehavioral performance measures, could lead to better predictions of long-term developmental outcomes. To this end, we examined whether variability in buccal cell DNA methylation (DNAm) associated with neurobehavioral profiles in a cohort of infants born less than 30 weeks postmenstrual age (PMA) and participating in the Neonatal Neurobehavior and Outcomes in Very Preterm Infants (NOVI) Study (N = 536). We tested whether epigenetic age, age acceleration, or DNAm levels at individual loci differed between infants based on their NICU Network Neurobehavioral Scale (NNNS) profile classifications. We adjusted for recruitment site, infant sex, PMA, and tissue heterogeneity. Infants with an optimally well-regulated NNNS profile had older epigenetic age compared to other NOVI infants (ß1 = 0.201, p-value = 0.026), but no significant difference in age acceleration. In contrast, infants with an atypical NNNS profile had differential methylation at 29 CpG sites (FDR < 10%). Some of the genes annotated to these CpGs included PLA2G4E, TRIM9, GRIK3, and MACROD2, which have previously been associated with neurological structure and function, or with neurobehavioral disorders. These findings contribute to the existing evidence that neonatal epigenetic variations may be informative for infant neurobehavior.

Group B Streptococcus Evades Host Immunity by Degrading Hyaluronan.

In response to tissue injury, hyaluronan (HA) polymers are cleaved by host hyaluronidases, generating small fragments that ligate Toll-like receptors (TLRs) to elicit inflammatory responses. Pathogenic bacteria such as group B Streptococcus (GBS) express and secrete hyaluronidases as a mechanism for tissue invasion, but it is not known how this activity relates to immune detection of HA. We found that bacterial hyaluronidases secreted by GBS and other Gram-positive pathogens degrade pro-inflammatory HA fragments to their component disaccharides. In addition, HA disaccharides block TLR2/4 signaling elicited by both host-derived HA fragments and other TLR2/4 ligands, including lipopolysaccharide. Application of GBS hyaluronidase or HA disaccharides reduced pulmonary pathology and pro-inflammatory cytokine levels in an acute lung injury model. We conclude that breakdown of host-generated pro-inflammatory HA fragments to disaccharides allows bacterial pathogens to evade immune detection and could be exploited as a strategy to treat inflammatory diseases.

Small Baby Unit Improves Quality and Outcomes in Extremely Low Birth Weight Infants.

OBJECTIVE: The survival rates for extremely low birth weight (ELBW) infants have improved, but many are discharged from the hospital with significant challenges. Our goal was to improve outcomes for this population by using a multidisciplinary team-based quality improvement approach. METHODS: A unique program called the Small Baby Unit (SBU) was established in a children's hospital to care for the ELBW infant born at 28 weeks or less and weighing less than 1000 g at birth. These patients were cared for in a separate location from the main neonatal unit. A core multidisciplinary team that participates in ongoing educational and process-improvement collaboration provides care. Evidence-based guidelines and checklists standardized the approach. RESULTS: Data from the 2 years before and 4 years after opening the SBU are included. There was a reduction in chronic lung disease from 47.5% to 35.4% (P = .097). The rate of hospital-acquired infection decreased from 39.3% to 19.4% (P < .001). Infants being discharged with growth restriction (combined weight and head circumference <10th percentile) decreased from 62.3% to 37.3% (P = .001). Reduced resource utilization was demonstrated as the mean number per patient of laboratory tests decreased from 224 to 82 (P < .001) and radiographs decreased from 45 to 22 (P < .001). CONCLUSIONS: Care in a distinct unit by a consistent multidisciplinary SBU team using quality improvement methods improved outcomes in ELBW infants. Ongoing team engagement and development are required to sustain improved outcomes.

Platelet-activating factor induces TLR4 expression in intestinal epithelial cells: implication for the pathogenesis of necrotizing enterocolitis.

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in neonatal intensive care units, however its pathogenesis is not completely understood. We have previously shown that platelet activating factor (PAF), bacteria and TLR4 are all important factors in the development of NEC. Given that Toll-like receptors (TLRs) are expressed at low levels in enterocytes of the mature gastrointestinal tract, but were shown to be aberrantly over-expressed in enterocytes in experimental NEC, we examined the regulation of TLR4 expression and signaling by PAF in intestinal epithelial cells using human and mouse in vitro cell lines, and the ex vivo rat intestinal loop model. In intestinal epithelial cell (IEC) lines, PAF stimulation yielded upregulation of both TLR4 mRNA and protein expression and led to increased IL-8 secretion following stimulation with LPS (in an otherwise LPS minimally responsive cell line). PAF stimulation resulted in increased human TLR4 promoter activation in a dose dependent manner. Western blotting and immunohistochemical analysis showed PAF induced STAT3 phosphorylation and nuclear translocation in IEC, and PAF-induced TLR4 expression was inhibited by STAT3 and NFκB Inhibitors. Our findings provide evidence for a mechanism by which PAF augments inflammation in the intestinal epithelium through abnormal TLR4 upregulation, thereby contributing to the intestinal injury of NEC.

The roles of bacteria and TLR4 in rat and murine models of necrotizing enterocolitis.

Bacteria are thought to contribute to the pathogenesis of necrotizing enterocolitis (NEC), but it is unknown whether their interaction with the epithelium can participate in the initiation of mucosal injury or they can act only following translocation across a damaged intestinal barrier. Our aims were to determine whether bacteria and intestinal epithelial TLR4 play roles in a well-established neonatal rat model and a novel neonatal murine model of NEC. Neonatal rats, C57BL/6J, C3HeB/FeJ (TLR4 wild type), and C3H/HeJ (TLR4 mutant) mice were delivered by Cesarean section and were subjected to formula feeding and cold asphyxia stress or were delivered naturally and were mother-fed. NEC incidence was evaluated by histological scoring, and gene expression was quantified using quantitative real-time PCR from cDNA generated from intestinal total RNA or from RNA obtained by laser capture microdissection. Spontaneous feeding catheter colonization or supplementation of cultured bacterial isolates to formula increased the incidence of experimental NEC. During the first 72 h of life, i.e., the time frame of NEC development in this model, intestinal TLR4 mRNA gradually decreases in mother-fed but increases in formula feeding and cold asphyxia stress, correlating with induced inducible NO synthase. TLR4, inducible NO synthase, and inflammatory cytokine induction occurred in the intestinal epithelium but not in the submucosa. NEC incidence was diminished in C3H/HeJ mice, compared with C3HeB/FeJ mice. In summary, bacteria and TLR4 play significant roles in experimental NEC, likely via an interaction of intraluminal bacteria and aberrantly overexpressed TLR4 in enterocytes.

Toll-like receptor-4 is required for intestinal response to epithelial injury and limiting bacterial translocation in a murine model of acute colitis.

Inflammatory bowel disease (IBD) arises from a dysregulated mucosal immune response to luminal bacteria. Toll-like receptor (TLR)4 recognizes LPS and transduces a proinflammatory signal through the adapter molecule myeloid differentiation marker 88 (MyD88). We hypothesized that TLR4 participates in the innate immune response to luminal bacteria and the development of colitis. TLR4-/- and MyD88-/- mice and littermate controls were given 2.5% dextran sodium sulfate (DSS) for 5 or 7 days followed by a 7-day recovery. Colitis was assessed by weight loss, rectal bleeding, and histopathology. Immunostaining was performed for macrophage markers, chemokine expression, and cell proliferation markers. DSS treatment of TLR4-/- mice was associated with striking reduction in acute inflammatory cells compared with wild-type mice despite similar degrees of epithelial injury. TLR4-/- mice experienced earlier and more severe bleeding than control mice. Similar results were seen with MyD88-/- mice, suggesting that this is the dominant downstream pathway. Mesenteric lymph nodes from TLR4-/- and MyD88-/- mice more frequently grew gram-negative bacteria. Altered neutrophil recruitment was due to diminished macrophage inflammatory protein-2 expression by lamina propria macrophages in TLR4-/- and MyD88-/- mice. The similarity in crypt epithelial damage between TLR4-/- or MyD88-/- and wild-type mice was seen despite decreased epithelial proliferation in knockout mice. TLR4 through the adapter molecule MyD88 is important in intestinal response to injury and in limiting bacterial translocation. Despite the diversity of luminal bacteria, other TLRs do not substitute for the role of TLR4 in this acute colitis model. A defective innate immune response may result in diminished bacterial clearance and ultimately dysregulated response to normal flora.

Accumulation of transforming growth factor-beta2 and nitrated chondroitin sulfate proteoglycans in cerebrospinal fluid correlates with poor neurologic outcome in preterm hydrocephalus.

BACKGROUND: Progressive post-hemorrhagic hydrocephalus in preterm infants strongly predicts abnormal neurologic development, and often accompanies cystic periventricular leukomalacia (cPVL). Transforming growth factor-beta1 (TGF-beta1), associated with hydrocephalus, can upregulate the chondroitin sulfate proteoglycan (CSPG) synthesis. To date, CSPG and their nitrated metabolites (NT-CSPG) have not been evaluated in hydrocephalus. OBJECTIVES: We hypothesized that TGF-beta1, TGF-beta2, CSPG, and NT-CSPG would accumulate in cerebrospinal fluid (CSF) in preterm hydrocephalus, and their concentrations would correlate with poor long-term outcomes. METHODS: TGF-beta1, TGF-beta2, CSPG, and NT-CSPG concentrations in CSF were measured prospectively by ELISA in 29 preterm newborns with (n=22) or without (n=34) progressive post-hemorrhagic hydrocephalus, and correlated with progressive neonatal hydrocephalus and neurologic outcome. Only concentrations from each patient's initial CSF sample were used for statistical analysis. RESULTS: Compared to neonates without hydrocephalus, CSF [TGF-beta1], [TGF-beta2], [CSPG] and [NT-CSPG] were significantly greater by >3-, >35-, >8-, and >3-fold, respectively. Unlike CSF [TGF-beta2] and [CSPG], [TGF-beta1] correlated with CSF [total protein]. Only CSF [NT-CSPG] correlated with cPVL. Unlike [TGF-beta2] or [CSPG], [NT-CSPG] correlation with preterm progressive post-hemorrhagic hydrocephalus (PPHH) was explained entirely by the presence of cPVL among these patients. [TGF-beta2] was >20-fold greater in preterm survivors who required a ventriculoperitoneal shunt for PPHH (n=9), as compared to survivors who did not require a shunt (n=2), or those without hydrocephalus (n=12). [TGF-beta2] and [NT-CSPG] correlated inversely with Bayley Index Scores (15.0 months median adjusted age). CONCLUSIONS: This is the first report that [TGF-beta2], [CSPG], and [NT-CSPG], measured well before term, accumulate abnormally in preterm progressive post-hemorrhagic hydrocephalus CSF, and correlate with adverse neurologic outcome.