Neonatal NEC Research Articles

Online registry of neonatal necrotising enterocolitis in Shenzhen: protocol for a multicentre, prospective, open, observational cohort study

IntroductionNecrotising enterocolitis (NEC) of the intestine of preterm infants leads to the risk of abdominal surgery, short bowel syndrome, neurodevelopmental disorders and death. Although the risks of NEC and its...

Influencing factors for surgical treatment in neonatal necrotizing enterocolitis: a systematic review and meta-analysis

BackgroundNecrotizing enterocolitis (NEC) is a complex disease characterized by gastrointestinal inflammation and is one of the most common gastrointestinal emergencies in neonates. Mild to moderate cases of NEC require medical treatment, whereas severe cases necessitate surgical intervention. However, evidence for surgical indications is limited and largely dependent on the surgeon’s experience, leading to variability in outcomes. The primary aim of this study is to identify the risk factors for surgical intervention in neonatal NEC, which will aid in predicting the optimal timing for surgical intervention.MethodsA literature search was conducted in PubMed, Embase, and Web of Science databases for case-control studies exploring risk factors for NEC requiring surgical intervention. The search was completed on June 16, 2024, and data analysis was performed using R Studio 4.3.2.Results18 studies were included, comprising 1,104 cases in the surgery group and 1,686 in the medical treatment group. The meta-analysis indicated that high C-reactive protein (CRP) levels [OR = 1.42, 95% CI (1.01, 1.99)], lower gestational age [OR = 0.52, 95% CI (0.3, 0.91)], sepsis [OR = 2.94, 95% CI (1.87, 4.60)], coagulation disorder [OR = 3.45, 95% CI (1.81, 6.58)], lack of enteral feeding [OR = 3.18, 95% CI (1.37, 7.35)], and hyponatremia [OR = 1.22, 95% CI (1.07, 1.39)] are significant risk factors for surgical treatment in neonatal NEC.ConclusionsHigh CRP levels, coagulation disorders, sepsis, lower gestational age, lack of enteral feeding, and hyponatremia are significant risk factors for surgical intervention in neonatal NEC. These findings have potential clinical significance for predicting surgical risk.

Do maternal BMI and gestational weight gain equally affect the risk of infant hypoxic and traumatic events?

Small (SGA) and large (LGA) for gestational age infants have higher risks of infant morbidity when compared to those who are appropriate for gestational age (AGA). Increasing pre-pregnancy maternal BMI and gestational weight gain (GWG) are associated with higher risks of LGA and lower risks of SGA infants; however, their direct effects on infant morbidity are unknown. Therefore, we intended to 1) assess how maternal pre-pregnancy BMI, GWG, and birthweight (categorized as SGA, AGA or LGA) affect infant morbidity and 2) estimate at entry of care the risk of infant morbidity according to pre-pregnancy BMI and possible GWG. we used Consortium on Safe Labor data, a retrospective observational cohort study collecting pregnancy and birth data from 2002 to 2008 in 12 US centers. The association between maternal BMI, GWG and infant morbidity was estimated in singleton gestations delivering ≥ 37 weeks using binomial logistic regression. Hypoxic composite neonatal morbidity was defined as any the following: stillbirth, neonatal death, resuscitation at birth, NICU admission, intracranial hemorrhage, PVH grade III and IV, neonatal seizures, NEC, meconium aspiration, CPAP or mechanical ventilation, RDS, and sepsis. Traumatic composite neonatal morbidity included shoulder dystocia or birth injuries. In this study of 110,594 mother-infant dyads, a total of 8,369 (7.6%) infants experienced hypoxic, while 2,134 (1.9%) developed traumatic morbidity. The risk of hypoxic morbidity among SGA, AGA and LGA infants increased when mothers were overweight (aOR 1.26 [95%CI 1.18-1.34]) or obese (class 1: aOR 1.3 [1.2-1.4]; class 2: aOR 1.7 [1.5-1.9]; class 3: aOR 1.8 [1.6-2]) as opposed to normal weight, and when GWG exceeded (aOR 1.08 [1.02-1.014]) rather than remained within recommendations. The risk of traumatic morbidity increased with maternal obesity (class 1: aOR 1.3 [1.1-1.5]), whilst it dropped with GWG below recommendations (aOR 0.7 [0.6-0.8]). The risk of hypoxic events estimated at entry of care increased with maternal overweight (aOR 1.27 [1.19-1.35]) or obesity (class 1: aOR 1.4 [1.2-1.5]; class 2: aOR 1.7 [1.5-1.9]; class 3: aOR 1.8 [1.6-2.1]), and with possible GWG above (aOR 1.09 [1.03-1.015]) recommendations. The risk of traumatic morbidity increased with overweight (aOR 1.1 [1-1.3]) or obesity (class 1: aOR 1.4 [1.2-1.6]; class 2: aOR 1.3 [1-1.6]), with possible GWG above (aOR 1.2 [1-1.3]), as opposed to below recommendations (aOR 0.7 [0.6-0.8]). While maternal pre-pregnancy BMI and GWG equally affected traumatic morbidity, the former had a greater impact on hypoxic complications. Therefore, weight control prior to pregnancy is at least as effective as avoiding excessive gestational weight gain to prevent neonatal morbidity.

Clinical impact of analgesic-sedative agents and peri-operative clinical status on white matter brain injury in preterm infants following surgical NEC.

The potential influence of exposure to analgesic-sedative agents (ASA) before, during, and after surgical NEC and peri-operative clinical status on white matter injury (WMI) in preterm infants has not been fully defined, and a comprehensive evaluation may inform future research and clinical interventions. A retrospective study comparing ASA exposure before/during /after surgical NEC and peri-operative clinical status in neonates with and without WMI. Infants with any WMI (grade 2-4, n = 36/67, 53.7%) had a higher number of surgical procedures receiving ASA (5 [IQR: 3, 8] vs. 3 [2, 4]; p = 0.002) and had a longer duration of hypotension during their first (48.0 hours [26.0, 48.0] vs. 15.5 [6, 48]; p = 0.009) and second surgery (20 hours [0, 48h] vs. 0 [0, 22]; p = 0.017), received more hydrocortisone (35% vs.13.3%,p = 0.04) than those without any WMI. There were no differences in fentanyl/morphine/midazolam exposure before/during/after the NEC onset in the two groups.Infants with severe WMI (19/67, 28.3%, grade 3/4) had a higher incidence of AKI (P = 0.004), surgical morbidity (p = 0.047), more surgical procedures (6.5 [3, 10] vs. 4 [2, 5]; p = 0.012), and received higher mean fentanyl doses(p = 0.03) from birth until NEC onset than those without severe WMI. The univariate associations between these factors and severe WMI remained insignificant after multivariable logistic regression. Infants with WMI had more surgical procedures receiving ASA and had a longer duration of hypotension during surgeries. A large multicenter prospective study is needed to understand the full impact of ASA.

Necrotizing enterocolitis in preterm infants: state of the intestinal barrier, features of vitamin D metabolism and their regulation

The priority of the national health policy is to preserve the life and a high level of quality of life for every premature baby. The clinical focus is on children born with ELBW. Among this category of children, NEC makes the main contribution to the structure of infant mortality. Based on the analysis of the literature, the authors conclude that the study of cell markers that characterize different depths of damage to enterocytes allows: to assess the likelihood of developing NEC in infants with ELMT; conduct early diagnosis of NEC; rule out NEC in neonates with similar symptoms; predict the course of NEC; propose and substantiate personalized approaches to correcting the low supply of 25(OH)D; to analyze the influence of candidate genes on the implementation of NEC, its outcomes, and 25(OH)D metabolism. To assess damage at the level of the enterocyte, the authors selected the intestinal fraction of fatty acid binding protein (I-FABP) for literature analysis. To determine the depth of damage to intercellular junctions of the intestine - the expression of transmembrane (claudin-2, claudin-3, claudin-4, occludin) and cytoplasmic (zonulin) tight junction proteins. Analysis of the results of studies on the expression of fecal calprotectin, lipocalin-2 (LCN2) and eosinophilic neurotoxin, showing the activity of local inflammation, was carried out in order to assess both the risk of NEC and its course. Intestinal damage is associated with impaired 25(OH)D metabolism, and metabolic bone disease in preterm infants with damage to the intestinal barrier up to NEC is recorded ten times more often at the stage of nursing in the NICU. A huge number of studies have shown a decrease in survival, an increase in the risk of severe complications against the background of a low supply of 25(OH)D in the preterm population. The authors analyze the relationship between 25(OH)D availability, taking into account the influence of exogenous and endogenous factors, the nature of damage to the intestinal wall and the implementation of NEC, and focus on the existing preventive and therapeutic approaches to prescribing various doses of vitamin D in preterm infants with NEC.

Early erythropoietin for preventing necrotizing enterocolitis in preterm neonates - an updated meta-analysis.

There is moderate to low-quality evidence that early prophylactic EPO reduces any stage and ≥ Stage II NEC in preterm neonates. Prospectively registered, adequately powered, double-blind RCTs are required to confirm these findings. • Experimental studies have shown that erythropoietin (EPO) has gastrointestinal trophic effects. • Systematic reviews have shown that early treatment with EPO may decrease the risk of gut injury in preterm or low birth weight infants. • Early EPO supplementation significantly reduced the incidence of any stage NEC and definite NEC in preterm infants < 34 weeks of gestation. • EPO had no significant effect on definite NEC in the analyses that included only double-blinded and prospectively registered RCTs. How might it impact clinical practice in the foreseeable future? • Early prophylactic EPO can be recommended for NEC prevention if its benefits are consistently demonstrated in adequately powered randomized trials with a low risk of bias.

Challenge in diagnosis of late onset necrotizing enterocolitis in a term infant: a case report

BackgroundNecrotizing enterocolitis (NEC) is a common devastating inflammatory gastrointestinal disease and frequently occurs in premature infants. Here, we reported a case of late-onset NEC in a term neonate with good outcome after surgery for long-term follow-up.Case presentationTen-week-old male came to emergency unit due to prolonged diarrhea and abdominal distention. He was born at gestational age of 40 weeks with birth weight and Apgar score of 2800 g and 7/8, respectively. He had no history of formula feeding. Two weeks before admitted to the hospital, the patient had frequent diarrhea with fever. He was found lethargic with abdominal distention, absence of bowel sounds and abdominal tenderness. Plain abdominal x-ray and CT scan showed gastric and intestinal dilatation and gasless colon, suggesting a small bowel obstruction, and bowel wall thickening indicating peritonitis, without any free subdiaphragmatic air (pneumoperitoneum). Moreover, the patient did not have a congenital heart disease. While in intensive medical treatment, he showed a continuous clinical deterioration. All findings were suggestive of intestinal inflammation with clinical deterioration, and we decided to perform an emergency exploratory laparotomy and found an ischemia along the jejunoileal with a perforation at 25 cm above the ileocecal valve. Subsequently, we performed a double-barrel ileostomy through a separate incision from the laparotomy. Histopathological findings confirmed the diagnosis of NEC. We closed the stoma at postoperative day 43. The patient was discharged uneventfully a month after stoma closure.ConclusionAbdominal CT scan might be useful to establish an early recognition of late-onset NEC; thus, immediate surgical intervention might be performed to decrease its morbidity and mortality. Moreover, late-onset NEC in term neonates might occur without any risk factors or significant co-morbidities.

Necrotizing enterocolitis intestinal barrier function protection by antenatal dexamethasone and surfactant-D in a rat model

BackgroundNecrotizing enterocolitis (NEC) is the most common gastrointestinal disorder in premature neonates. Possible therapeutic approaches are centered on promoting maturation of the gastrointestinal mucosal barrier. Studies have demonstrated that antenatal administration of corticosteroids can decrease NEC incidence and mortality.MethodsPregnant rat dams were administered dexamethasone 48 h prior to delivery. The pups were subjected to an experimental NEC-like injury protocol. Ileal tissues and sera were collected and evaluated for inflammatory cytokines, gut permeability and expressions and localizations of tight junction proteins, and surfactant protein-D by immunohistochemistry/immunofluorescent staining. Intestinal epithelial cells (IEC-6) were pretreated with SP-D to examine the effect of SP-D on tight junction protein expressions when challenged with platelet-activating factor and lipopolysaccharide to model proinflammatory insults.ResultsAntenatal dexamethasone reduced systemic inflammation, preserved intestinal barrier integrity, and stimulated SP-D expression on the intestinal mucosal surface in pups exposed to NEC-like injury. Pretreatment of SP-D blocked platelet-activating factor/lipopolysaccharide-induced tight junction disruption in IEC-6 cells in vitro.ConclusionsAntenatal dexamethasone preserves the development of intestinal mucosal barrier integrity and reduces incidence and morbidity from an experimental NEC-like injury model. Dexamethasone upregulation of intestinal SP-D-protective effects on tight junction proteins.ImpactAntenatal administration of dexamethasone can function in concert with intestinal surfactant protein-D to decrease systemic inflammatory responses, and protect intestinal barrier integrity in a neonatal rat model of NEC.A novel role of intestinal SP-D in preserving tight junction protein structures under inflammatory conditions.We describe the intestinal SP-D—an overlooked role of antenatal dexamethasone in neonatal NEC?

The effect of concomitant histologic chorioamnionitis in pregnancies complicated by fetal growth restriction

IntroductionWe aimed to investigate the effect of placental histologic chorioamnionitis (HC) on neonatal outcomes in pregnancies complicated by fetal growth restriction (FGR). Methods- The computerized medical files of all pregnancies diagnosed with FGR (birthweight <10th percentile) at 24–42 weeks of gestation between 2008 and 2019 were reviewed. Maternal and neonatal outcomes were compared between FGR with and without evidence of placental HC.Placental lesions were classified according to “Amsterdam” criteria. Composite adverse neonatal outcome-included any of the following complications: neurological morbidity, neonatal respiratory assistance, RDS, NEC, sepsis, blood transfusion, phototherapy, hypoglycemia, or neonatal death. Composite severe adverse neonatal outcome included any of the following complications – neurological morbidity, blood transfusion, NEC, sepsis, RDS, neonatal death. Results- Compared to FGR without HC (n = 446), FGR with HC (n = 57) was characterized by more advanced gestational age at delivery 39.2 (38.3–39.9) vs. 38.2 (36.9–39.2), weeks respectively, p < 0.001), higher rate of nulliparity (73.7% vs. 45.1%, p < 0.001), less vascular lesions of MVM (1.8% vs.11.2%, p = 0.02), higher rate of Apgar scores at 5 min <7 (10.5% vs. 2%, p = 0.004), increased neonatal death (7.0% vs. 0.9%, p = 0.007), higher rates of both composite adverse neonatal outcome (31.1% vs. 17.3% p = 0.02), and composite severe adverse neonatal outcome (16.3% vs. 8.2% p = 0.04).By multivariate regression analysis HC was found to be independently associated with composite adverse neonatal outcome (aOR = 1.21, 95% CI 1.08–2.38) and with severe composite adverse neonatal outcome (aOR = 1.39, 95% CI 1.16–3.76). ConclusionsPregnancies complicated by FGR with concomitant HC were associated with higher rates of adverse neonatal outcomes.

The pattern of neonatal gastro-intestinal perforation in upper Egypt

BackgroundNeonatal gastro-intestinal perforation [NGIP] is one of the major problems in pediatric surgical practice. Although the outcomes of neonatal surgery have improved markedly over the past decade the mortality rates of neonates with NGIP are still high. The aim of this study was to present the possible etiological factors, clinical findings, and operative procedures of NIP in our locality.ResultsA total of 34 neonates with NGIP were included in this study. The median age at presentation was (15.8 ± 7.0 SD) days. The median interval between presentation and surgical interference was (2.0 ± 1.1 SD).Necrotizing enterocolitis [NEC] was the commonest cause of neonatal gastro-intestinal perforation. The commonest site of perforation was the colon [11cases]. The overall mortality rate was 11 cases [32.4%]. The main cause of mortality was neonatal NEC [6 cases]. Eight cases [40 %] died out of 20 cases which the interval between the presentation and interference were more than one day.ConclusionsNeonatal gastro-intestinal perforations are still associated with high mortality rate in our institutions, and delayed diagnosis with increased interval between the presentation and surgical intervention are associated with increased mortality. In our locality, although NEC is the commonest cause of NGIP, the iatrogenic cause is relatively higher than reported.

TNF-α induces autophagy through ERK1/2 pathway to regulate apoptosis in neonatal necrotizing enterocolitis model cells IEC-6

ABSTRACTNecrotizing enterocolitis (NEC) is a potentially fatal illness in premature neonates. Tumor necrosis factor-α (TNF-α) and autophagy are associated with the pathogenesis of NEC. This study aimed to explore whether TNF-α might regulate apoptosis in neonatal NEC model cells IEC-6 via regulation of autophagy. NEC rat model was induced by hand feeding and exposure to asphyxia/cold-stress for histologic examination. The NEC in vitro model (IEC-6/NEC cells) was established by stimulating the intestinal epithelial cell line IEC-6 with lipopolysaccharide (LPS, 100 μg/mL) for 3 h to investigate the effects of TNF-α on IEC-6 proliferation and apoptosis. In this study, NEC rats showed decreased proliferating cell nuclear antigen (PCNA) expression, increased TUNEL-positive cells, higher expression of TNF-α, p-ERK1/2, and autophagy-related proteins in rat small intestine compared with their controls. Additionally, the LPS-stimulated IEC-6/NEC cells showed a significantly decreased proliferation and increased apoptosis compared with the control cells. Furthermore, the LPS-stimulated IEC-6/NEC cells exhibited enhanced autophagy level, as evidenced by a dose-dependent increase in Beclin-1 protein expression, LC3II/LC3I ratio and accumulation of MDC-positive autophagic vacuoles. Moreover, inhibition of autophagy by wortmannin or LY294002 significantly abolished the LPS-mediated decreased proliferation and increased apoptosis of IEC-6/NEC cells. Results also showed that inhibition of ERK1/2 pathway using U0126 significantly inhibited TNF-α-induced autophagy. Furthermore, the TNF-α-mediated inhibition of IEC-6 proliferation and promotion of IEC-6 apoptosis was abolished by U0126. Our findings demonstrated that TNF-α might induce autophagy through ERK1/2 pathway to regulate apoptosis in neonatal NEC cells IEC-6. Our study enhances our understanding of neonatal NEC pathogenesis.

Comparison between two doses of betamethasone administration with 12 hours vs. 24 hours intervals on prevention of respiratory distress syndrome: a randomised trial

The purpose of the present study was to compare the effect of a two-dose administration of betamethasone with 12 hours interval vs. 24 hours interval on neonatal respiratory distress syndrome (RDS). The study was performed as a randomised clinical trial on 201 pregnant women with a gestational age of 26–34 weeks. In one group 12 mg of betamethasone every 12 hours for two doses and in the other group 12 mg of betamethasone every 24 hours for two doses were prescribed intramuscularly. There were no significant differences between the two groups according to maternal age, parity, gravidity, BMI, neonatal sex, need to surfactant, NICU admission, NICU stay, neonatal death, neonatal sepsis and Apgar score at minutes 1 and 5, but the gestational age at the beginning of the study and delivery receiving complete course of betamethasone and neonatal weight were lower in 24 hours group. RDS, necrotising enterocolitis, intra-ventricular haemorrhage and chorioamnionitis were more in the 24 hours’ group. Multiple regression analysis showed that RDS and IVH (p = .022, RR = 0.07, CI95% 0.006–0.96 and p = .013; RR = 0.9, CI95% 0.1–0.89, respectively) were more in the 24 hours group and neonatal death (p = .034, RR = 4.7, CI95% 1.07–16.2) and NEC (p = 0.038, RR = 2.5, CI95% 1.7–3.7), were more in the 12 hours group. In conclusion, it seems that 12 hours interval betamethasone therapy may be considered as an alternative treatment in the case of preterm labour for acceleration of lung maturity; however, it is suggested that more studies should be performed on this issue and various morbidities.IMPACT STATEMENTWhat is already known on this subject: Administration of a single course of corticosteroids in all women with a gestational age of 24–34 weeks of pregnancy who are at risk for preterm labour and delivery has been recommended. The accepted regimen by National Institutes of Health (NIH) is an injection of betamethasone for two doses with 24 hours interval.What do the results of this study add: Twelve hours interval betamethasone therapy may be considered as an alternative treatment in the cases of preterm labour for acceleration of lung maturity.What are the implications of these findings for clinical practice and/or further research: Prescription of two doses (complete regimen) is more important than the interval between two doses for obtaining the maximum effect in a preterm birth.

Dimethyloxalylglycine preserves the intestinal microvasculature and protects against intestinal injury in a neonatal mouse NEC model: role of VEGF signaling.

BackgroundNEC is a devastating neonatal disease characterized by intestinal necrosis. Hypoxia inducible factor-1α (HIF-1α) plays a critical role in cellular oxygen homeostasis. Here, we hypothesized that prolyl hydroxylase (PHD) inhibition, which stabilizes HIF-1α, protects against NEC by promoting intestinal endothelial cell proliferation and improving intestinal microvascular integrity via VEGF signaling.MethodsTo assess the role of PHD inhibition in a neonatal mouse NEC model, we administered DMOG or vehicle to pups prior to or during the NEC protocol, and determined mortality and incidence of severe intestinal injury. We assessed intestinal VEGF by Western blot and quantified endothelial cell and epithelial cell proliferation following immunofluorescence.ResultsDMOG decreased mortality and incidence of severe NEC, increased intestinal VEGF expression, and increased intestinal villus endothelial and epithelial cell proliferation in experimental NEC. Inhibiting VEGFR2 signaling eliminated DMOG’s protective effect on intestinal injury severity, survival, and endothelial cell proliferation while sparing DMOG’s protective effect on intestinal epithelial cell proliferation.ConclusionDMOG upregulates intestinal VEGF, promotes endothelial cell proliferation and protects against intestinal injury and mortality in experimental NEC in a VEGFR2-dependent manner. DMOG’s protective effect on the neonatal intestinal mucosa may be mediated via VEGFR-2 dependent improvement of the intestinal microvasculature.

Risk factors for necrotizing enterocolitis in neonates: a systematic review of prognostic studies

BackgroundNecrotizing enterocolitis (NEC) is a severe multifactorial disease in preterm neonates associated with high morbidity and mortality. Better insight into prognostic values of the many reported factors associated with NEC is needed to enable identification of neonates at risk for NEC. The aim was to systematically review the literature to identify independent risk factors for NEC from the literature.MethodsMedline, Cochrane, Embase, Pubmed and Google Scholar were searched systematically for cohort studies reporting prognostic factors for NEC in neonates using multivariable analysis. Studies were scored with the Quality In Prognosis Studies tool (QUIPS).ResultsFrom 5154 initial hits, 14 prognostic studies were included, with various designs. Study quality was rated high in three studies, moderate or low in the 11 others. Significant prognostic factors for NEC reported in at least two studies were: low birth weight, small for gestational age, low gestational age, assisted ventilation, premature rupture of membranes, black ethnicity, sepsis, outborn, hypotension (all increased risk), surfactant therapy (conflicting results) and cesarean section (lower risk). Meta-analysis was considered not feasible.ConclusionHigh quality studies on prognostic factors for NEC are rare. Several prognostic factors, that are not necessarily causal, are associated with NEC. High quality prognostic research is necessary to establish the predictive values of these factors.

Immunoregulation effects of different γδT cells and toll-like receptor signaling pathways in neonatal necrotizing enterocolitis.

The aim of the study was to observe cytokine and T-cell-related toll-like-receptor (TLR) changes in intestinal samples of neonatal necrotizing enterocolitis patients.Four necrotic bowels were collected from neonatal NEC patients with gestational ages of 28 to 29 weeks in our hospital, whereas 4 neonatal patients who underwent intestinal atresia surgery served as the controls. Intestinal flora was examined and IL-1, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α, IFN-γ, and IL-17 expressions in resected intestine samples, as well as in isolated gamma delta T (γδT) cells, were analyzed immunohistochemically and via quantitative RT-PCR. γδT cells were isolated from the intestinal intraepithelial lymphocytes (IELs) and their TLR4/TLR9 distribution in the intestinal tissues was determined by flow cytometry.The bacterial flora of the neonatal NEC patients’ contained significantly higher amounts of Gram-negative Enterobacteriaceae, Klebsiella, and Bacteroides but anaerobic Gram-positive Bifidobacteria occurred significantly less in the NEC than the control group. IL-1, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α, IFN-γ, and IL-17 expressions in the resected intestine samples and in isolated γδT cells were enhanced in NEC samples compared to the controls. γδT cells were less prevalent in NEC-derived intestinal tissues, but their TLR4/TLR9 expressions were significantly enhanced.The changed bacterial flora in preterm neonatal NEC patients led to an obvious inflammation of the intestines, which was accompanied by reductions of γδT cell localizations to the intestine and a shift of their surface expressions to TLR4 and TLR9.

Blocking NF‐κB activation in intestinal Lysozyme M positive cells prevents the NEC‐induced decrease in Ly6C positive cells in the neonatal intestine

Necrotizing enterocolitis is a devastating necrotic gastro‐intestinal inflammatory disease of premature infants. We previously found that NF‐κB activation in myeloid cells but not intestinal epithelial cells mediates the intestinal injury in an experimental neonatal mouse NEC model, suggesting that myeloid cells play an important role in the pathogenesis of NEC. While myeloid cells contain various subsets, how these are affected in NEC remains unknown. Here, we examine whether NEC development is associated with alteration of monocyte phenotypes in the lamina propria (LP) of neonatal intestines, and if so, whether NF‐κB activation mediates the effect. To do so, litters containing a mixture of LysM‐Cre+/− IKKβF/F (mice lacking IKKβ, the upstream kinase responsible for NF‐κB activation in myeloid cells) and IKKβF/F mice were exposed to a NEC protocol consisting in adult commensal bacteria inoculation‐oral LPS/hypoxia/cold stress/formula feeding or allowed to be dam fed. 24 or 48 hours later, small intestinal tissues were harvested and lamina propria (LP) cells were isolated and analyzed by flow cytometry for the alive, CD11b, CD45 Ly6C and Ly6G markers. We found that, in control mice (IKKβF/F), exposure to the NEC protocol caused a significant decrease in the percentage of Ly6C+ cells (monocytes) in the intestinal LP compared to DF controls (4.2%±0.8 vs 22.3%±2.7; p&lt;0.05), which was attenuated when IKKβ was deleted in myeloid cells (Lys‐Cre+/− IKKβF/F; 10.2%±1.2; p&lt;0.05). To determine whether IKKβ was deleted in this preserved Ly6C+ population, we repeat the analysis with pups of Lys‐M cre IKKβF/F mice bred with mT/mG mice to identify the specific cell population undergoing cre‐recombination, as they express GFP. We found that, in dam fed pups, LysM‐cre recombination and therefore IKKβ deletion was mostly found in the Ly6C+ population (94±0.9%) and represented 17±1.5% of CD11b+ cells in Lys‐Cre+/− IKKβF/WT DF mice. However, when exposed to the NEC protocol for 24 hours, Lys‐Cre+/−IKKβF/WT pups (non‐IKKβ deleted) had only 56±3.5% of cells with cre recombination that were Ly6C+ while Lys‐Cre+/− IKKβF/F pups (IKKβ deleted) had 95% of cells with cre‐recombination/IKKβ deletion that remained LY6C+, suggesting that NF‐κB may mediate Ly6C down regulation in NEC. However, exposure to the NEC protocol did not significantly change the total percentage of cells with cre‐recombination. In conclusion, NEC exposure reduces the percentage of Ly6C+ cells, which is dependent on NF‐κB activation in the Ly6C+ population. Since loss of Ly6C is an important marker of differentiation to CX3CR1+ vessel patrolling monocytes or CX3CR1+MHCII+ intestinal macrophages, we speculate that NF‐κB dependent loss of Ly6C+ cells during NEC exposure may affect the intestinal homeostasis including the microvasculature thus predisposing to NEC.Support or Funding InformationThis study was supported by funding from NIH grant R01HD060876 (IDP).

Asociaciones de probióticos para la prevención de la enterocolitis necrosante y la reducción de la sepsis tardía y la mortalidad neonatal en recién nacidos pretérmino de menos de 1.500 g: una revisión sistemática

Introduction and objectiveNecrotising enterocolitis (NEC) is one of the most common and serious acquired bowel diseases a premature newborn can face. This meta-analysis was performed comparing different probiotic mixtures to ascertain their benefits as a routine tool for preventing necrotising enterocolitis and reducing late-onset sepsis and mortality in premature neonates of less than 1500g. Material and methodsA systematic review of randomised controlled trials, between January 1980 and March 2014, on MEDLINE, the Cochrane Central Register of Controlled Trials, together with EMBASE, was carried out. Studies with infants <1500g or <34 weeks were selected, discarding those with Jadad scores lower than 4. Results9 studies were selected for further investigation, pooling a total of 3521 newborns. Probiotics were found to reduce the NEC incidence (RR 0.39; 95%CI: 0.26-0.57) and mortality (RR 0.70; 95%CI: 0.52-0.93), with no difference to placebo regarding late-onset sepsis (RR 0.91; 95%CI: 0.78-1.06). Finally, when analysing the different strands, the use of a 2-probiotic combination (Lactobacillus acidophilus with Bifidobacterium bifidum) proved to be statistically significant in reducing all-cause mortality when compared to other probiotic combinations (RR 0.32; 95%CI: 0.15-0.66, NNT 20; 95%CI: 12-50). ConclusionsProbiotics are a beneficial tool in the prevention of NEC and mortality in preterm neonates. Moreover, the combination of 2 probiotics (Lactobacillus acidophilus with Bifidobacterium bifidum) seems to produce the greatest benefits. However, due to the differences in probiotic components and administration, it would be wise to perform a randomised controlled trial comparing different probiotic mixtures.

OC15.07: A reduced cerebral placental ratio in fetuses at risk of preterm delivery is associated with neonatal sepsis and necrotising enterocolitis (NEC)

Spontaneous preterm labour and delivery (sPTD) is causally linked to intra-amniotic infection/inflammation. Microbial invasion of the fetus leads to a systemic response with cardiac dysfunction and hemodynamic changes. The aim of this study was to evaluate if an abnormal cerebral placental ratio (CPR) alone, or in combination with the uterine arteries (Ut) Doppler velocimetry can predict adverse neonatal outcome in patients presenting with sPTD. A cohort of 3,972 pregnant women underwent serial ultrasound (US) examinations from the first trimester until delivery. The CPR (middle cerebral artery [MCA]-pulsatility index [PI]/Umbilical artery [UA]-PI) and the extended CPR including the mean Ut-PI (MCA-PI/UA-PI + Ut-PI) were calculated at the last US examination prior to sPTD (within two weeks) and the association and diagnostic performance for neonatal sepsis and/or NEC were evaluated. The analysis included adjustment for the following co-variables: gestational age at delivery, estimated fetal weight, clinical chorioamnionitis and premature rupture of membranes. Overall, 495 fetuses presented with sPTD at < 37 weeks of gestation and 44 (8.8%) had proven neonatal sepsis and/or NEC. Both the CPR and the Ext-CPR ratios were significantly associated with neonatal sepsis and/or NEC (CPR, OR = 5.39 (95% CI 2.97–9.79); p < 0.0001; Ext-CPR, OR = 11.38 (95% CI 4.31–30.05); p < 0.0001). After adjustment for all co-variables, the association remained significant: CPR: OR = 2.36 (95% CI 1.12–4.99); p = 0.02; Ext-CPR: OR = 4.31 (95% CI 1.45–12.57); p = 0.008. Diagnostic metrics showed that: 1) a CPR of < 1.18 had an AUC of 0.76 with a sensitivity of 37.2% and specificity of 91%; and 2) an Ext-CPR of < 0.73 had an AUC of 0.74 with a sensitivity of 43.6% and specificity of 91.1% for neonatal sepsis and/or NEC. Inclusion of the mean Ut-PI marginally improved the diagnostic performance of the CPR. The CPR in fetuses delivered preterm can identify those at risk for neonatal sepsis and/or NEC.

Enteral L-Arginine and Glutamine Supplementation for Prevention of NEC in Preterm Neonates.

Objective. Evaluating the efficacy and safety of arginine and glutamine supplementation in decreasing the incidence of NEC among preterm neonates. Methods. Prospective case-control study done on 75 preterm neonates ≤34 weeks, divided equally into L-arginine group receiving enteral L-arginine, glutamine group receiving enteral glutamine, and control group. Serum L-arginine and glutamine levels were measured at time of enrollment (sample 1), after 14 days of enrollment (sample 2), and at time of diagnosis of NEC (sample 3). Results. The incidence of NEC was 9.3%. There was no difference in the frequency of NEC between L-arginine and control groups (P > 0.05). NEC was not detected in glutamine group; L-arginine concentrations were significantly lower in arginine group than control group in both samples while glutamine concentrations were comparable in glutamine and control groups in both samples. No significant difference was found between groups as regards number of septic episodes, duration to reach full oral intake, or duration of hospital stay. Conclusion. Enteral L-arginine supplementation did not seem to reduce the incidence of NEC. Enteral glutamine may have a preventive role against NEC if supplied early to preterm neonates. However, larger studies are needed to confirm these findings. This work is registered in ClinicalTrials.gov (ClinicalTrials.gov Identifier: NCT01263041).

PS-186 Blood Lactate As A Predictive Marker For Neonatal Necrotising Enterocolitis (nec) Severity And Operative Outcomes: Abstract PS-186 Table 1

Background and aims Lactate as a marker for tissue perfusion and hypoxia is increasingly used in routine point-of-care monitoring in critical care. We investigated the association of pre-operative lactate (PreL) with operative outcomes and mortality in neonatal surgical NEC. Methods 25 infants with NEC confirmed on laparotomy at a tertiary surgical centre were retrospectively evaluated. Maximal PreL was categorised as normal ( 5 mmol/L), and correlated to extent of NEC involvement and mortality. Results Median birth gestation and weight were 27weeks (range 23–33) and 1035g (555–2060). Median PreL was 5.1(range 0.6–16.2)mmol/L. Elevated PreL correlated with NEC severity, with predominance of pan-intestinal and multifocal involvement in severe hyperlactaemia (Table 1). Infants with isolated NEC were observed to have normal or moderate-PreL. Moderate to severe PreL was also associated with increased mortality rate and need for further surgery. Conclusions This preliminary study suggests that pre-operative hyperlactaemia and degree of elevation may be associated with a poor prognosis in infants with surgical NEC. Further larger studies may enable better evaluation of its use an adjunctive monitoring or prognostic tool in guiding early neonatal NEC management.