Hyponatremia as a Marker for Predicting Surgical Intervention in Necrotizing Enterocolitis: A Retrospective Cohort Study.

INTRODUCTION: To investigate the predictive value of plasma sodium at the onset of necrotizing enterocolitis (NEC) diagnosis in distinguishing surgical NEC from medical NEC. METHODS: A retrospective review of all NEC neonates treated at our hospital between 2008 and 2022. Patients were divided into two groups based on treatment methods: surgical intervention and medical treatment. Patient demographics, laboratory parameters, and outcomes were all documented. The values of laboratory parameters were collected at the onset of NEC and after treatment. To identify potential predictors of surgical NEC, multivariate logistic regression analyses were used. The receiver operating characteristic curve was applied to determine predictive factors. RESULTS: Surgical treatment was performed in 111 infants (44.6%), and medical treatment in 138 cases (55.4%). Of 249 infants with NEC, 22 patients exhibited Bell stage I, 91 infants had Bell stage II, and 136 patients displayed Bell stage III. We discovered that white blood cell (WBC), C-reactive protein (CRP), fibrinogen, and sodium were independent predictors of NEC receiving surgery based on the results of the multivariate logistic regression analysis. Hyponatremia was found in 122 of the 249 patients (49%). At the onset of NEC diagnosis, hyponatremia was found in 83.8% of surgical intervention group and in 21.0% of medical treatment group (P < 0.001). Sensitivity, specificity, positive predictive value, and negative predictive value for WBC, CRP, fibrinogen, and sodium were calculated. The cutoff values were determined using receiver operating characteristic analysis. The area under the curve of hyponatremia for surgical intervention was 0.875, with 84% sensitivity, 80% specificity, 77% positive predictive value, and 86% negative predictive value, which had a greater specificity (0.80) for predicting surgical intervention than WBC (0.67), CRP (0.50), and fibrinogen (0.70). CONCLUSIONS: When a surgical evaluation is necessary, hyponatremia can effectively distinguish surgical NEC from medical NEC. It could be used as a predictive marker to guide parental counseling for surgical intervention and rapid transfer of patients to tertiary centers when they have a surgical condition.

Neurodevelopmental impairment following surgical necrotizing enterocolitis with gestational age ≥ 28 weeks: who is at risk?

PURPOSE: Surgical necrotizing enterocolitis (NEC) is a severe medical condition that, even after surgery, a portion of the survival infants may still have neurological sequelae. The objective of this study was to identify the risk factors associated with the development of permanent neurodevelopmental impairment (NDI) in neonates with surgical NEC. METHODS: Between January 2016 and June 2022, a retrospective data collection was conducted on 98 individuals who experienced surgical NEC with gestational age ≥ 28 weeks. Among these patients, 27 patients were diagnosed with NDI, while the remaining 71 patients did not have NDI. Based on this division, the patients were categorized into the NDI group and the Non-NDI group. Demographics, comorbidities, and admission lab results were analyzed using univariate and logistic regression analyses. RESULTS: Of the 98 neonates following surgical NEC, 27(27.6%) developed permanent neurodevelopmental impairment (NDI). Predictors of NDI were identified through the final multivariable logistic regression analysis, which revealed that gestational age ≤ 32 weeks (p = 0.032; odds ratio [OR], 5.673), assisted mechanical ventilation after NEC onset (p = 0.047; OR, 5.299), postoperative acute kidney injury (p = 0.040; OR, 5.106), CRP day 3 after NEC onset (p = 0.049; OR, 1.037), time from presentation to surgery (p = 0.003; OR, 1.047) were significant risk factors. CONCLUSIONS: Our study identified gestational age ≤ 32 weeks, assisted mechanical ventilation after NEC onset, postoperative acute kidney injury, CRP day 3 after NEC onset, and time from presentation to surgery as significant risk factors for NDI in neonates with surgical NEC. These factors would be helpful to refine treatment modalities for better disease outcomes. We also determined the cut-off values of CRP day 3 after NEC onset and time from presentation to surgery, allowing for the individualized evaluation of NDI risk and the implementation of earlier targeted laparotomy.

Heterogeneity of food protein-induced enterocolitis syndrome (FPIES).

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy with gastrointestinal symptoms such as vomiting and diarrhea. The development of international consensus guidelines for the diagnosis and management of FPIES in 2017 enabled us to compare patients worldwide, regardless of geographic variation in disease features. As a result, it has become clear that there is heterogeneity among patients with FPIES or that there are cases that partly fit the diagnostic criteria for FPIES but have different characteristics. This review highlights the heterogeneity in FPIES characteristics in terms of trigger foods, the age of onset, differences in geographic regions, and symptoms; it further proposes four disease entities, including acute FPIES in children, acute FPIES in adults, chronic FPIES, and early-onset neonatal FPIES, depending on the age of onset and presumed pathophysiology. The major symptoms at onset and trigger foods differ in acute FPIES in children, acute FPIES in adults, and chronic FPIES, whereas the disease entities may share a similar pathophysiology. Early-onset neonatal FPIES may have a different pathophysiology than acute or chronic FPIES, and may not necessarily fulfil the full diagnostic criteria for acute or chronic FPIES described in the international consensus guidelines. Due to the similarity in symptoms, early-onset neonatal FPIES may sometimes be misdiagnosed as necrotizing enterocolitis. We aim to increase awareness of FPIES among medical staff in pediatrics, neonatology, and internal medicine and promote research, to gain a better understanding of the heterogeneity and pathophysiology of FPIES.

In vivo phenotyping of the microvasculature in necrotizing enterocolitis with multicontrast optical imaging.

OBJECTIVE: Necrotizing enterocolitis (NEC) is the most prevalent gastrointestinal emergency in premature infants and is characterized by a dysfunctional gut microcirculation. Therefore, there is a dire need for in vivo methods to characterize NEC-induced changes in the structure and function of the gut microcirculation, that is, its vascular phenotype. Since in vivo gut imaging methods are often slow and employ a single-contrast mechanism, we developed a rapid multicontrast imaging technique and a novel analyses pipeline for phenotyping the gut microcirculation. METHODS: Using an experimental NEC model, we acquired in vivo images of the gut microvasculature and blood flow over a 5000 × 7000 µm2 field of view at 5 µm resolution via the following two endogenous contrast mechanisms: intrinsic optical signals and laser speckles. Next, we transformed intestinal images into rectilinear "flat maps," and delineated 1A/V gut microvessels and their perfusion territories as "intestinal vascular units" (IVUs). Employing IVUs, we quantified and visualized NEC-induced changes to the gut vascular phenotype. RESULTS: In vivo imaging required 60-100 s per animal. Relative to the healthy gut, NEC intestines showed a significant overall decrease (i.e. 64-72%) in perfusion, accompanied by vasoconstriction (i.e. 9-12%) and a reduction in perfusion entropy (19%)within sections of the vascular bed. CONCLUSIONS: Multicontrast imaging coupled with IVU-based in vivo vascular phenotyping is a powerful new tool for elucidating NEC pathogenesis.

Portal Vein Gas in Neonates: Predicting Clinical Treatment Outcomes From Ultrasound Findings.

OBJECTIVES: To identify sonographic findings that predict clinical outcomes in neonates with portal vein gas. METHODS: This retrospective study included neonates with portal vein gas detected using ultrasound (US). The US images were reviewed by a pediatric radiologist. US findings included the extent and amount of portal vein gas, mesenteric vein gas, intramural gas, bowel wall thickening or thinning, focal discontinuity of the bowel wall, ascites, free intra-abdominal gas, pseudocyst, gas in the other solid organs, and bowel distension. The imaging findings and demographic factors between survivors and non-survivors were statistically compared. RESULTS: The mortality rate was 26% (39 survivors, 14 non-survivors) when iatrogenic and idiopathic causes were excluded. The causes of portal vein gas were determined to be necrotizing enterocolitis (n = 33), bowel distension or obstruction (n = 12), fetal hydrops (n = 4), pneumothorax (n = 3), immediate postoperative state for bowel perforation (n = 1), and umbilical vein catheterization (n = 9) based on surgical findings (n = 20) and clinical information (n = 46). Gas within the mesenteric vein and the other solid organs, gestational age, and birth weight were significantly different between survivors and those who succumbed (P < .05). CONCLUSION: Gas within the mesenteric vein and other solid organs is a US finding that may predict poor outcomes in neonates with portal vein gas.

Effect of time of diagnosis to surgery on outcome, including long-term neurodevelopmental outcome, in necrotizing enterocolitis.

A systematic review of the PubMed and EMBASE databases was carried out to determine if time from diagnosis to surgery affects outcomes in necrotising enterocolitis. The study was registered on the PROSPERO website. Studies reporting both time to surgery and at least one clinical outcome measure in infants undergoing surgery for NEC were included. The initial search returned 1121 articles. After removing duplicates, title, and abstract screening, 49 remained for full-text review. Of these, only two reported both timing of surgery for NEC and at least one clinical outcome. The total number of neonates included was 202. Outcomes reported were death and/or parenteral nutrition use 28 days post surgery in one study and white matter brain injury in the other. No statistically significant association was found between any of the outcomes reported and timing of surgery. There were, however, significant differences associated with non-modifiable risk factors, such as age and gestation, at presentation. However, very few studies report this as a variable. Given the continuing poor outcomes and heterogeneous nature of NEC and its treatments, further large-scale prospective studies are required to examine the impact of timing of surgery, alongside other, potentially modifiable factors on outcome in NEC.

Hepatic oxidative injury: role of mitochondrial dysfunction in necrotizing enterocolitis.

PURPOSE: Necrotizing enterocolitis (NEC) is a severe neonatal gastrointestinal disease that can cause damage to remote organs. Previous studies have shown that inflammatory and oxidative injury occur in the liver during NEC. Mitochondrial DNA (mtDNA) plays an important role in hepatic injuries of many other diseases. We aimed to investigate the mechanism of mitochondrial dysfunction in hepatic oxidative injury during NEC. METHODS: NEC was induced in C57BL/6 mice (approval: 44032) by hypoxia, gavage feeding with hyperosmolar formula, and lipopolysaccharide administration from postnatal days 5 to 9 (n = 15). Two additional groups with hypoxia only (n = 10) and hypoxia and hyperosmolar formula (n = 13) were also examined. Breastfed pups were used as control (n = 15). Liver was harvested on postnatal day 9. Gene expressions of mtDNA markers cytochrome c oxidase subunit 3 (COX3), cytochrome b (CYTB) and NADH-ubiquinone oxidoreductase chain 1 (ND1) were measured by real-time qPCR. Mitochondrial morphology marker HSP60 and oxidative stress marker NRF2 were detected by immunofluorescence staining and compared between NEC and control. Data were presented as mean ± SD and compared using Student's t test; p < 0.05 was considered significant. RESULTS: Gene expression of mtDNA markers (COX3, CYTB, and ND1) were significantly decreased in the liver of NEC mice relative to control, hypoxia alone, and hypoxia with hyperosmolar formula. Immunofluorescence showed depletion of HSP60 indicating decreased mitochondria in NEC liver relative to control. Furthermore, a higher protein expression of NRF2 was observed indicating higher oxidative stress in NEC liver relative to control. CONCLUSIONS: Intestinal injury in experimental NEC leads to a systemic inflammatory response affecting the liver. Hepatic oxidative injury in NEC is characterized by decreased mitochondria and mtDNA depletion. This study provides insight into the mechanism of liver injury in NEC.

Doppler ultrasound assessment of splanchnic perfusion and heart rate for the detection of necrotizing enterocolitis.

PURPOSE: Monitoring disease progression is crucial to improve the outcome of necrotizing enterocolitis (NEC). A previous study indicates that intestinal wall flow velocity was reduced in NEC pups from the initial stages of the disease. This study aims to investigate whether splanchnic perfusion via the superior mesenteric artery (SMA) (i) is altered during NEC development and (ii) can be used as a monitoring tool to assess disease progression. METHODS: NEC was induced in C57BL/6 mice via gavage feeding of formula, hypoxia, and oral lipopolysaccharide, from postnatal day 5 (P5) to P9 (AUP: 32,238). Breastfed littermates served as controls. Doppler ultrasound (U/S) of bowel loops was performed daily. Intestinal wall perfusion was calculated as average flow velocity (mm/s) of multiple abdominal regions. Groups were compared using one-way ANOVA. RESULTS: The SMA flow velocity was not altered during the initial stage of NEC development, but become significantly reduced at P8 when the intestinal disease was more advanced. These changes occurred concomitantly with an increase in heart rate. CONCLUSIONS: NEC is associated with intestinal hypo-perfusion at the periphery and flow in the SMA is reduced during the later stages of disease indicating the presence of intestinal epithelium damage. This study contributes to understanding NEC pathophysiology and illustrates the value of Doppler U/S in monitoring disease progression.

Serum bile acids profiling by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and its application on pediatric liver and intestinal diseases.

Background A method for bile acid profiling measuring 21 primary and secondary bile acids in serum samples was developed and validated with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample preparation included spiking with internal standards followed by protein precipitation, centrifugation, drying under nitrogen gas and reconstitution. Extracted samples were injected onto a Phenomenex Kinetex C18 column (150 × 4.60 mm, 2.6 µm). Methods Data was collected with LC-MS/MS operated in negative ion mode with multiple reaction monitoring (MRM) and single reaction monitoring (SRM). The analytical run time was 12 min. Results The method showed excellent linearity with high regression coefficients (>0.99) over a range of 0.05 and 25 µM for all analytes tested. The method also showed acceptable intra-day and inter-day accuracy and precision. As a proof of concept, the analytical method was applied to patients with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD), biliary atresia (BA), and necrotizing enterocolitis (NEC), and distinct bile acids profiles were demonstrated. Conclusions The method could be poised to identify possible biomarkers for non-invasive early diagnosis of these disorders.

Calcium/calmodulin-dependent protein kinase IV signaling pathway is upregulated in experimental necrotizing enterocolitis.

PURPOSE: Activation of calcium/calmodulin-dependent protein kinase IV (CaMKIV) has been shown to increase intestinal injury and inhibit epithelial cell proliferation in dextran sulfate sodium (DSS)-induced colitis mice. However, the role of CaMKIV in necrotizing enterocolitis (NEC) is unknown. We aimed to study the expression and activation of CaMKIV in experimental NEC. METHODS: Following ethical approval, NEC (n = 10) was induced in C57BL/6 mouse pups by hypoxia, gavage hyperosmolar formula feeding and lipopolysaccharide from postnatal days P5 to 9. Breastfed pups served as control (n = 10). Mouse pups were sacrificed on P9 and the terminal ileum was harvested. Gene NEC injury was scored blindly by three independent investigators. CaMKIV, CREM and IL17 gene expression, and CaMKIV and pCaMKIV protein expression were assessed. The data were compared using Mann-Whitney U test. P < 0.05 was considered significant. RESULTS: Intestinal injury was induced in the NEC mice and confirmed by histological scoring and inflammatory cytokine IL6. CaMKIV and its downstream target genes of CREM and IL17 were significantly elevated in NEC mice relative to control. Similarly, phosphorylated-CaMKIV (pCaMKIV), the active form of CaMKIV, was more notably expressed in the NEC ileal tissue relative to control ileal tissue. Elevated pCaMKIV protein expression was also confirmed by western blot. CONCLUSION: CaMKIV expression and activation are upregulated in experimental NEC suggesting a potential contributing factor in the pathogenesis of NEC.

Ontogeny of alkaline phosphatase activity in infant intestines and breast milk.

BACKGROUND: Necrotizing enterocolitis (NEC) is a devastating disease of intestinal inflammation that primarily affects premature infants. A potential risk factor for necrotizing enterocolitis is exposure of the premature neonatal intestine to environmental bacteria and their proinflammatory products such as lipopolysaccharide. The metalloenzyme alkaline phosphatase (ALP) has been shown to reduce lipopolysaccharide-mediated inflammation. Additionally, premature rat pups have reduced alkaline phosphatase activity and expression as compared to full term pups. To explore the possibility that the human premature neonatal intestine has a paucity of alkaline phosphatase activity, we measured endogenously produced intestinal alkaline phosphatase activity in meconium as a function of gestational age. To test whether breast milk could serve as a source of exogenous alkaline phosphatase to the neonatal intestine through ingestion, we measured alkaline phosphatase activity in breast milk across a range of time points post-birth. METHODS: Alkaline phosphatase activity was quantified in 122 meconium samples from infants of gestational ages ranging from 24 to 40 weeks and in 289 breast milk samples collected from 78 individual mothers between days 2-49 post-birth. RESULTS: We observed a strong positive correlation between the meconium alkaline phosphatase activity and gestational age, with preterm infants having lower meconium alkaline phosphatase activities than early term or term infants. Breast milk alkaline phosphatase activity was highest in the first week post-birth, with peak alkaline phosphatase activity at day 2 post-birth, followed by relatively low alkaline phosphatase activity in weeks 2-7. CONCLUSIONS: Our results are consistent with the two major risk factors for necrotizing enterocolitis development, preterm birth and lack of breast milk feeding, both contributing to a paucity of alkaline phosphatase activity and impaired capacity to detoxify proinflammatory bacterial products such as lipopolysaccharide.

A comparison of exosomes derived from different periods breast milk on protecting against intestinal organoid injury.

AIM OF THE STUDY: Human breast milk reduces the risk and severity of necrotizing enterocolitis (NEC). Exosomes are extracellular vesicles (EVs) found in high concentrations in milk, and they mediate intercellular communication and immune responses. The aim of this study is to compare the protective effects of exosomes that are derived from different time periods of breast milk production against intestinal injury using an ex vivo intestinal organoid model. METHODS: Colostrum, transitional and mature breast milk samples from healthy lactating mothers were collected. Exosomes were isolated using serial ultracentrifugation and filtration. Exosomes' presence was confirmed using transmission electron microscopy (TEM) and western blot. To form the intestinal organoids, terminal ileum was harvested from neonatal mice pups at postnatal day 9, crypts were isolated and organoids were cultured in matrigel. Organoids were either cultured with exposure to lipopolysaccharide (LPS), or in treatment groups where both LPS and exosomes were added in the culturing medium. Inflammatory markers and organoids viability were evaluated. MAIN RESULTS: Human milk-derived exosomes were successfully isolated and characterized. LPS administration reduced the size of intestinal organoids, induced inflammation through increasing TNFα and TLR4 expression, and stimulated intestinal regeneration. Colostrum, transitional and mature human milk-derived exosome treatment all prevented inflammatory injury, while exosomes derived from colostrum were most effective at reducing inflammatory cytokine. CONCLUSIONS: Human breast milk-derived exosomes were able to protect intestine organoids against epithelial injury induced by LPS. Colostrum exosomes offer the best protective effect among the breast-milk derived exosomes. Human milk exosomes can be protective against the development of intestinal injury such as that seen in NEC.

Role of intestinal Hsp70 in barrier maintenance: contribution of milk to the induction of Hsp70.2.

BACKGROUND: Necrotizing enterocolitis (NEC) is a gastrointestinal disease of complex etiology resulting in devastating systemic inflammation and often death in premature newborns. We previously demonstrated that formula feeding inhibits ileal expression of heat shock protein-70 (Hsp70), a critical stress protein within the intestine. Barrier function for the premature intestine is critical. We sought to determine whether reduced Hsp70 protein expression increases neonatal intestinal permeability. METHODS: Young adult mouse colon cells (YAMC) were utilized to evaluate barrier function as well as intestine from Hsp70-/- pups (KO). Sections of intestine were analyzed by Western blot, immunohistochemistry, and real time PCR. YAMC cells were sub-lethally heated or treated with expressed milk (EM) to induce Hsp70. RESULTS: Immunostaining demonstrates co-localized Hsp70 and tight junction protein zona occludens-1 (ZO-1), suggesting physical interaction to protect tight junction function. The permeability of YAMC monolayers increases following oxidant injury and is partially blocked by Hsp70 induction either by prior heat stress or EM. RT-PCR analysis demonstrated that the Hsp70 isoforms, 70.1 and 70.3, predominate in WT pup; however, Hsp70.2 predominates in the KO pups. While Hsp70 is present in WT milk, it is not present in KO EM. Hsp70 associates with ZO-1 to maintain epithelial barrier function. CONCLUSION: Both induction of Hsp70 and exposure to EM prevent stress-induced increased permeability. Hsp70.2 is present in both WT and KO neonatal intestine, suggesting a crucial role in epithelial integrity. Induction of the Hsp70.2 isoform appears to be mediated by mother's milk. These results suggest that mother's milk feeding modulates Hsp70.2 expression and could attenuate injury leading to NEC. LEVEL OF EVIDENCE: Level III.

Osmolality of enteral formula and severity of experimental necrotizing enterocolitis.

PURPOSE: Administration of hyperosmolar formula is regarded as a risk factor for the development of necrotizing enterocolitis (NEC). However, there are limited number of reports about the relationship between formula osmolality and NEC. The aim of this study is to evaluate the effects of formula concentration in an experimental model of NEC. METHODS: We studied experimental NEC in C57BL/6 mice. NEC was induced by giving hypoxia, gavage administration of lipopolysaccharide and gavage formula feeding from postnatal day 5-9. We used two types of formula: (1) hyperosmolar formula (HF): 15 g Similac + 75 ml Esbilac (849 mOsm/kg); (2) diluted formula (DF): dilute hyperosmolar formula with an equal amount of water (325 mOsm/kg). Controls were fed by the mother. On postnatal day 9, the ileum was harvested and evaluated for severity of mucosal injury (hematoxylin/eosin staining) and inflammation (PCR for IL6 and TNFα mRNA expression). RESULTS: The incidence of NEC was same in both HF and DF (80%). The intestinal inflammatory response was similar between HF and DF (IL6: p = 0.26, TNFα: p = 0.69). CONCLUSIONS: This study indicates the osmolality of enteral formula does not affect incidence of experimental NEC. This experimental study provides new insights into the relationship between formula feeding and NEC.

Advancing necrotizing enterocolitis prediction through iterative monitoring.

Background: Necrotizing enterocolitis (NEC) is a severe inflammatory intestinal disease in preterm infants, marked by heightened morbidity and mortality. Timely prediction of NEC is significant in the management of critical neonates. However, it is difficult to predict NEC accurately because of the multi-factorial pathogenesis. This study aimed to develop a prediction model through repeated measurement data to further improve the accuracy of prediction in NEC. Methods: We retrospectively collected clinical data of premature infants admitted to the Neonatology Department of the First Affiliated Hospital of Anhui Medical University from January 2016 to December 2023. The infants were categorized into the NEC group (Bell's stage ≥ II) (n=150) and the non-NEC group (n=150). The clinical baseline data of the NEC and non-NEC groups were matched. Laboratory examination indicators were collected on the 1st day, the 7th day after birth, and the day of NEC onset. Univariate and multivariate logistic regression analyses were conducted to identify independent factors influencing NEC. A nomogram was constructed based on these factors to predict NEC. The concordance index and calibration plot were used to assess the efficiency of the nomogram in the training and validation cohorts. Results: This study demonstrated that antenatal steroids, antenatal antibiotics, probiotics treatment before NEC, anion gap (AG, day 7), and mean corpuscular volume (MCV, day 7) were independent risk factors which combined to accurately predict NEC. A nomogram of NEC was created utilizing these five predictors. With an area under the receiver operator characteristic (ROC) curve of 0.835 [95% confidence interval (CI): 0.785-0.884]. Concordance index for the training and validation groups were 0.835 and 0.848, respectively. As the calibration plots indicate, the predicted probability of NEC is highly consistent with the actual observation. Conclusions: The risk estimation nomogram for NEC offers clinical value by guiding early prediction, targeted prevention, and early intervention strategies for NEC.

Unexpected decrease in necrotizing enterocolitis morbidity during the COVID-19 pandemic-A single-centre retrospective study.

Background: The impact of the coronavirus disease 2019 (COVID-19) pandemic on neonatal necrotizing enterocolitis (NEC) is not well characterised. This cross-sectional study evaluated the potential effects of pandemic-related measures on NEC morbidity in premature infants in a neonatal ward during the COVID-19 pandemic. Methods: This was a retrospective study conducted in a tertiary neonatal ward in eastern and central China over 6 consecutive years (2017, 2018, 2019, 2020, 2021 and 2022). The medical records of 189 premature infants with stage II or III NEC were reviewed for clinical manifestations and aetiologies. The data were analysed and compared between the prepandemic period (2017, 2018, and 2019) and the pandemic period (2020, 2021 and 2022). Results: A total of 9,903 infants with gestational age (GA) < 37 weeks were enrolled, including 5,382 in the prepandemic period and 4,521 in the pandemic period. A reduction in stage II or III NEC morbidity was observed in infants with GA < 37 weeks, with an average annual morbidity of 2.29% (123/5,382) (95% CI, 1.89%-2.68%) in the prepandemic period and 1.46% (66/4,521) (95% CI, 1.11%-1.81%) in the pandemic period. NEC morbidity showed resurgent characteristics in 2021. When prepandemic coinfections were excluded, most cases of NEC with bloodstream infections in the prepandemic period were attributable to Gram-negative bacteria (27/32, 84.38%), mainly Klebsiella pneumoniae, while in the pandemic period they were attributable to Gram-positive bacteria (10/18, 55.56%), mainly Staphylococcus aureus. Antimicrobial susceptibility testing revealed that Klebsiella pneumoniae was 100% sensitive to meropenem, imipenem, ciprofloxacin and levofloxacin and 100% resistant to ampicillin. Staphylococcus capitis was 100% sensitive to vancomycin, linezolid, tetracycline, cotrimoxazole and cefoxitin and 100% resistant to penicillin and benzathine. Conclusions: COVID-19 pandemic-related interventions can reduce the morbidity of NEC and change the pathogen spectrum in patients with bloodstream infections. We need to understand the exact factors leading to these changes.

Necrotizing Enterocolitis in an Infant With a History of Twin-Twin Transfusion Syndrome: A Case Report.

This case report describes necrotizing enterocolitis (NEC) in an infant with a history of twin-twin transfusion syndrome (TTTS). TTTS is a volume imbalance where the anastomosis at the vascular equator between the two placentae shifts from the donor to the recipient twin. This causes a higher risk for NEC, a marked inflammation caused by bacterial infection into the intestinal wall, from prematurity and intestinal hypoperfusion. Complications include sepsis, bowel necrosis, perforation, peritonitis, and death. NEC is a leading cause of morbidity in preterm infants. A 3-month-old female with a history of TTTS and prematurity presented with her mother to the pediatric emergency department (ED) for bloody diarrhea, emesis, lack of appetite, and lethargy for 4 days. The pediatrician changed the formula due to a possible milk allergy, however, she continued to have bloody diarrhea. Over the 2 days, the patient had nonbilious and non-bloody emesis and couldn't tolerate oral intake. In the ED, labs showed neutropenia and sepsis. She had a positive fecal occult blood test (FOBT) and an abdominal x-ray that revealed dilated loops of bowel and pneumatosis intestinalis. She was started on intravenous (IV) fluids for maintenance of hydration. She was started on broad-spectrum antibiotics including intravenous (IV) vancomycin and meropenem, and had her feedings temporarily stopped. The patient was transferred to the pediatric intensive care unit (PICU) at a tertiary care/children's hospital that evening where she had a laparotomy performed to resect the diseased intestine. She was discharged 10 days after the surgery for home recovery with clinical follow-up.

A Case of an Extremely Preterm Infant with Intussusception Triggered by Acquired Cytomegalovirus Infection.

Intussusception is a common cause of intestinal obstruction in infants aged 6-18 months. However, intussusception in preterm neonates (IPN) is an exceedingly rare disorder. The etiology of IPN remains unclear, but common prenatal injuries, such as those causing intestinal hypoxia/hypoperfusion, dysmotility, and strictures, have been proposed as possible contributing factors. Diagnosis is often delayed because the symptoms closely resemble those of necrotizing enterocolitis (NEC). Given the divergent treatments for IPN and NEC, establishing an early and accurate diagnosis is crucial. IPN is predominantly located in the small intestine (91.6%), and ultrasonography proves useful in its diagnosis. We present a case of a very preterm infant who developed intussusception triggered by acquired cytomegalovirus (aCMV) infection, necessitating surgical treatment. The cause of intussusception in this case was diagnosed as aCMV enteritis because no organic lesions were observed in the advanced part of the intussusception. The presence of CMV was confirmed by CMV-DNA-PCR examination of the resected intestinal tract. Intestinal edema and decreased intestinal peristalsis due to aCMV enteritis are likely the primary causes of the intussusception.

Quantitative Proteomic Analysis Identifying and Evaluating TRAF6 and IL-8 as Potential Diagnostic Biomarkers in Neonatal Patients with Necrotizing Enterocolitis.

Necrotizing enterocolitis (NEC) is a common gastrointestinal complication in premature infants, resulting in high morbidity and mortality, and its early detection is crucial for accurate treatment and outcome prediction. Extensive research has demonstrated a clear correlation between NEC and extremely low birth weight, degree of preterm, formula feeding, infection, hypoxic/ischemic damage, and intestinal dysbiosis. The development of noninvasive biomarkers of NEC from stool, urine, and serum has attracted a great deal of interest because to these clinical connections and the quest for a deeper knowledge of disease pathophysiology. Therefore, this study aims to identify protein expression patterns in NEC and discover innovative diagnostic biomarkers. In this study, we recruited five patients diagnosed with NEC and paired necrotic segments of intestinal tissue with adjacent normal segments of intestine to form experimental and control groups. Quantitative proteomics tandem mass tagging (TMT) labeling technique was used to detect and quantify the proteins, and the expression levels of the candidate biomarkers in the intestinal tissues were further determined by quantitative polymerase chain reaction (RT-qPCR), Western blot analysis, Immunofluorescence methods and enzyme-linked immunosorbent assay (ELISA). A total of 6880 proteins were identified and quantified in patients with NEC. A significant disparity in protein expression was observed between necrotic and normal segments of intestinal tissue in NEC patients. A total of 55 proteins were found to be upregulated, and 40 proteins were found to be downregulated in NEC patients when using a p-value of < 0.05, and an absolute fold change of > 1.2 for analysis. GO function enrichment analysis showed the positive regulation of significant biological processes such as mitochondrial organization, vasoconstriction, rRNA catabolism, fluid shear stress response, and glycerol ether biosynthesis processes. Enrichment analysis also revealed essential functions such as ligand-gated ion channel activity, potassium channel activity, ligand-gated cation channel activity, ligand-gated ion channel activity, and ligand-gated channel activity, including molecular functions such as ligand-gated ion channel activity and mitotic events in this comparative group. Significant changes were found in endomembrane protein complex, membrane fraction, mitochondrial membrane fraction, membrane components, membrane intrinsic components, and other localized proteins. Additional validation of intestinal tissue and serum revealed a substantial increase in TRAF6 (tumor necrosis factor receptor-associated factor 6) and IL-8(Interleukin-8, CXCL8). The quantitative proteomic TMT method can effectively detect proteins with differential expression in the intestinal tissues of NEC patients. Proteins TRAF6 and CXCL8/IL-8 are significantly upregulated in the intestinal tissues and serum samples of patients and may serve as valuable predictor factors for NEC's early diagnosis.