Changing the paradigm of defining, detecting, and diagnosing NEC: Perspectives on Bell's stages and biomarkers for NEC

Gut microbiota differences in five-year-old children that were born preterm with a history of necrotizing enterocolitis: A pilot trial

The study explores the long-term effects of necrotizing enterocolitis (NEC) on gut microbiota in preterm infants by analyzing stool samples from 5-year-old children using shotgun metagenomic sequencing. It compares children with a history of NEC, treated surgically or medically, to preterm controls without NEC. Findings reveal persistent gut microbiota dysbiosis in NEC children, with reduced species diversity and evenness, especially in those treated surgically. The surgical NEC group had a lower Shannon index, indicating less microbial diversity. Significant differences in taxonomic profiles were observed, mainly influenced by surgical treatment. These results underscore the lasting impact of NEC and its treatment on gut microbiota, suggesting a need for strategies addressing long-term dysbiosis.

Clinical Characteristics of Necrotizing Enterocolitis Diagnosed by Independent Adjudication of Abdominal Radiographs, Laparotomy, or Autopsy in Preterm Infants in the "Connection Trial"

OBJECTIVE

 Necrotizing enterocolitis (NEC) classically is diagnosed by radiographic demonstration of pneumatosis intestinalis/portal venous gas (PI/PVG). This study examines clinical characteristics of NEC confirmed by independent evaluation of abdominal radiographs, taken for clinical signs of NEC, or by pathologic findings at laparotomy or autopsy (confirmed NEC [cNEC]).

STUDY DESIGN

 The investigated cohort included 1,382 extremely low birth weight (BW) infants (BW range: 500-1,000 g) with median 27 weeks (range: 23-32) gestational age (GA) at birth. They were randomized into the placebo-controlled "Connection Trial" of the new biological drug candidate IBP-9414 with cNEC as one primary endpoint.

RESULTS

 Total 119 infants (8.6%) had cNEC diagnosed at median 14 days of age by confirming PI/PVG at X-ray adjudication (n = 111) and/or by surgery/autopsy (n = 21). Sixteen percent of cNEC cases died. Adverse events of NEC were reported in 8.5% of infants and 4.1% had NEC diagnosed by radiology and surgery/autopsy at the participating centers. Regression analyses showed that the risk of cNEC decreased by 11 to 30% for every 100-g increment in BW and single-week increment in GA and associated cNEC with odds ratios (ORs) > 2.0 for gastrointestinal (GI) perforation and obstruction, hypotension, hypokalemia, hypophosphatemia, and death. Comparing risks of cNEC in infants below and above 750-g BW showed higher ORs (2.7-4.3) for GI perforation, hypotension, hypokalemia, and renal complications in the smaller infants, whereas the bigger infants had higher ORs (1.9-3.2) for serious non-GI events, late-onset sepsis (LOS), and death. Predictors of cNEC (hazard ratio, HR > 1.5) included serious non-GI events (mainly infections), hyponatremia, and hyperglycemia, whereas the HR was 0.52 for intravenous antibiotics. After cNEC diagnosis, there were higher rates of GI perforation and obstruction, hypotension, hypokalemia, and LOS.

CONCLUSION

 Independent adjudication of abdominal radiographs increased radiological recognition of NEC and proved to be feasible in a multicenter study setting as well as able to diagnose clinically relevant NEC.

KEY POINTS

· Independent adjudication of abdominal radiographs in ELBW infants increased NEC recognition.. · Risk of NEC decreased by 11 to 30% with every 100-g increment in BW and GA week.. · In infants with BW 750 to 1,000 g, the risk of death from NEC was almost twice that in infants with BW 500 to 749 g. · Infants with NEC received antibiotics during one-third and parenteral nutrition during half of the first 7 postnatal weeks..

Reassessing acquired neonatal intestinal diseases using unsupervised machine learning

BACKGROUND

Acquired neonatal intestinal diseases have an array of overlapping presentations and are often labeled under the dichotomous classification of necrotizing enterocolitis (which is poorly defined) or spontaneous intestinal perforation, hindering more precise diagnosis and research. The objective of this study was to take a fresh look at neonatal intestinal disease classification using unsupervised machine learning.

METHODS

Patients admitted to the University of Florida Shands Neonatal Intensive Care Unit January 2013-September 2019 diagnosed with an intestinal injury, or had imaging findings of portal venous gas, pneumatosis, abdominal free air, or had an abdominal drain placed or exploratory laparotomy during admission were included. Congenital gastroschisis, omphalocele, intestinal atresia, malrotation were excluded. Data was collected via retrospective chart review with subsequent hierarchal, unsupervised clustering analysis.

RESULTS

Five clusters of intestinal injury were identified: Cluster 1 deemed the "Low Mortality" cluster, Cluster 2 deemed the "Mature with Inflammation" cluster, Cluster 3 deemed the "Immature with High Mortality" cluster, Cluster 4 deemed the "Late Injury at Full Feeds" cluster, and Cluster 5 deemed the "Late Injury with High Rate of Intestinal Necrosis" cluster.

CONCLUSION

Unsupervised machine learning can be used to cluster acquired neonatal intestinal injuries. Future study with larger multicenter datasets is needed to further refine and classify types of intestinal diseases.

IMPACT

Unsupervised machine learning can be used to cluster types of acquired neonatal intestinal injury. Five major clusters of acquired neonatal intestinal injury are described, each with unique features. The clusters herein described deserve future, multicenter study to determine more specific early biomarkers and tailored therapeutic interventions to improve outcomes of often devastating neonatal acquired intestinal injuries.

Artificial Intelligence vs. Doctors: Diagnosing Necrotizing Enterocolitis on Abdominal Radiographs

BACKGROUND

Radiographic diagnosis of necrotizing enterocolitis (NEC) is challenging. Deep learning models may improve accuracy by recognizing subtle imaging patterns. We hypothesized it would perform with comparable accuracy to that of senior surgical residents.

METHODS

This cohort study compiled 494 anteroposterior neonatal abdominal radiographs (214 images NEC, 280 other) and randomly divided them into training, validation, and test sets. Transfer learning was utilized to fine-tune a ResNet-50 deep convolutional neural network (DCNN) pre-trained on ImageNet. Gradient-weighted Class Activation Mapping (Grad-CAM) heatmaps visualized image regions of greatest relevance to the pretrained neural network. Senior surgery residents at a single institution examined the test set. Resident and DCNN ability to identify pneumatosis on radiographic images were measured via area under the receiver operating curves (AUROC) and compared using DeLong's method.

RESULTS

The pretrained neural network achieved AUROC of 0.918 (95% CI, 0.837-0.978) with an accuracy of 87.8% with five false negative and one false positive prediction. Heatmaps confirmed appropriate image region emphasis by the pretrained neural network. Senior surgical residents had a median area under the receiver operating curve of 0.896, ranging from 0.778 (95% CI 0.615-0.941) to 0.991 (95% CI 0.971-0.999) with zero to five false negatives and one to eleven false positive predictions. The deep convolutional neural network performed comparably to each surgical resident's performance (p > 0.05 for all comparisons).

CONCLUSIONS

A deep convolutional neural network trained to recognize pneumatosis can quickly and accurately assist clinicians in promptly identifying NEC in clinical practice.

LEVEL OF EVIDENCE

III (study type: Study of Diagnostic Test, study of nonconsecutive patients without a universally applied "gold standard").

Assessment of hemostatic profile in neonates with necrotizing enterocolitis using Rotational Thromboelastometry (ROTEM)

BACKGROUND

This study aimed to explore the hemostatic profile of neonates with necrotizing enterocolitis (NEC) using Rotational Thromboelastometry (ROTEM) and to investigate if ROTEM parameters have the capacity to play a role in the differentiation of NEC from sepsis at the disease onset.

METHODS

This observational study included 62 neonates (mean gestational age 31.6 weeks and mean birth weight 1620g) hospitalized in a neonatal intensive care unit. The neonates were categorized in three groups: neonates with NEC (Bell stage II and above), neonates with sepsis and healthy neonates and they were matched 1:1:1 with regards to gestational age, delivery mode, and sex. Clinical, laboratory data as well as measurements of ROTEM parameters at disease onset were recorded.

RESULTS

ROTEM parameters differed between neonates with NEC and neonates with sepsis, indicating that NEC results in accelerated clot formation and higher clot strength compared to sepsis. The EXTEM CFT and A10 parameters demonstrated the highest diagnostic performance for NEC in terms of discrimination between NEC and sepsis (AUC, 0.997; 95% CI: 0.991-1.000 and 0.973; 95% CI: 0.932-1.000, respectively).

CONCLUSIONS

Neonates with NEC manifested accelerated clot formation and higher clot strength compared to septic and healthy neonates, as these were expressed by ROTEM parameters.

IMPACT

This work reports data on the hemostatic profile of neonates with necrotizing enterocolitis (NEC) using Rotational Thromboelastometry (ROTEM) and the capacity of ROTEM parameters in differentiating of NEC from sepsis at the disease onset. Neonates with NEC present acceleration of coagulation and exhibit a hypercoagulable profile, as this is expressed by ROTEM parameters, in comparison to septic and healthy neonates. ROTEM parameters demonstrated a good diagnostic capacity in differentiating NEC from sepsis at the disease onset.

Bedside Ultrasound for Early Diagnosis of Necrotizing Enterocolitis: A Pilot Study

OBJECTIVE

This study aimed to assess whether bedside ultrasound (BUS) as the first imaging modality allows an earlier diagnosis of necrotizing enterocolitis (NEC) compared with abdominal radiography.

STUDY DESIGN

A before-after controlled study in preterm infants with suspected NEC. The intervention group (October 2019-October 2021) received BUS as the first imaging modality and was managed accordingly to BUS findings. The control group (October 2015-September 2019) received radiography as the first imaging modality. The main outcome was NEC confirmation at the time of initial imaging. Secondary outcomes included time to diagnosis, laboratory data, and treatment requirements.

RESULTS

Thirty-five episodes of suspected NEC with 14 (40%) confirmed NEC cases and 49 episodes of suspected NEC with 22 (44.9%) confirmed NEC cases were included in the intervention and control groups, respectively. In the intervention group, 11 of 14 (78.6%) NEC cases were confirmed at initial evaluation compared with 5 of 22 (22.7%) in the control group (p = 0.001). Infants in the intervention group developed thrombocytopenia and coagulopathy less frequently, were exposed to less radiation, and required less days of parenteral nutrition compared with the control group (p < 0.05).

CONCLUSION

The use of BUS as the first imaging modality allowed an earlier diagnosis and timely treatment of NEC compared with abdominal radiography.Key Points · This is the first study that has assessed the role of BUS as the first imaging modality in NEC.. · BUS improves early diagnosis of NEC compared with abdominal radiography.. · BUS shortens time to NEC confirmation and treatment initiation which may reduce clinical severity of the NEC episode..

Necrotizing Enterocolitis in Very Low Birth Weight Neonates: A Natural History Study

OBJECTIVE

We characterize the most recent natural history of necrotizing enterocolitis (NEC), as this is an essential first step in guiding the prevention and treatment of this disease in the present day.

STUDY DESIGN

We performed a retrospective cohort study of neonates who were born at 23 to 29 weeks' gestation and birth weight <1,500 g who received care from the Pediatrix Medical Group between 2004 and 2019. We assessed the incidence of medical and surgical NEC and the patterns of initial antibiotic treatment to develop a contemporary cohort for further analysis. Among patients discharged between 2015 and 2019, we characterized the stage-specific risk factors for patients diagnosed with medical or surgical NEC, as well as patterns of disease onset, progression, biomarkers, and outcomes. We used the same approach to characterize patients diagnosed with suspected NEC.

RESULTS

Among 34,032 patients in the contemporary cohort, 1,150 (3.4%) were diagnosed with medical NEC and 543 (1.6%) were diagnosed with surgical NEC. The temporal pattern of disease onset was different for medical and surgical NEC, with gestational age- and birth weight-specific risk disparities emerging earlier in surgical NEC. Thirty-day mortality was much greater among surgical NEC patients (medical NEC 16.4% vs. surgical NEC 43.0%), as were rates of various in-hospital and long-term outcomes. Suspected NEC was diagnosed in 1,256 (3.7%) patients, among whom risk factors and disease onset, progression, and outcomes closely resembled those of medical NEC.

CONCLUSION

Analyzing data from a contemporary cohort enabled us to characterize the current, stage-specific natural history of NEC, including novel insights into suspected NEC. Future studies could leverage this cohort to characterize how specific patient characteristics, care processes, or biomarkers may influence or predict disease outcomes.

KEY POINTS

· The incidence of NEC has reached a stable baseline in recent years.. · Risk factors for NEC vary in a stage-specific manner.. · The stage-specific onset and progression of NEC differ by gestational age and birth weight..

Comparison of preoperative and intraoperative surgeon diagnosis and pathologic findings in spontaneous intestinal perforation vs necrotizing enterocolitis

OBJECTIVE

To investigate the accuracy of preoperative and intraoperative diagnosis via comparison to pathologic diagnosis in spontaneous intestinal perforation (SIP) vs. necrotizing enterocolitis (NEC).

STUDY DESIGN

A retrospective review of neonates <1500 g treated for pneumoperitoneum between 07/2004-09/2022 was conducted. Patients treated for NEC medically prior to diagnosis and those treated with drain only were excluded. Fleiss' Kappa analysis assessed agreement between all three diagnoses: preoperative, intraoperative, and pathologic.

RESULT

Overall, 125 patients were included with mean birthweight 834.2 g (SD:259.2) and mean gestational age 25.8 weeks (SD:2.2). Preoperative and intraoperative diagnoses agreed in 90.3%, intraoperative and pathologic agreed in 71.1%, and preoperative and pathologic agreed in 75.2% of patients. Fleiss' Kappa was 0.55 (95% CI:0.43,0.68), indicating moderate agreement between the three diagnoses.

CONCLUSION

Our study shows moderate agreement between preoperative, intraoperative, and pathologic diagnoses. Further studies investigating the clinical characteristics of SIP and NEC are needed to improve diagnostic accuracy and management.

Outcomes by disease onset, sex, and intervention in neonates with SIP and surgical NEC

BACKGROUND

Outcomes of infants following surgical necrotizing enterocolitis (NEC) and spontaneous intestinal perforation (SIP) categorized by the age of onset, interventions, and sex are not well defined.

METHODS

Retrospective comparison of infants categorized by age of onset (NEC at <10, 10-20, and >20 days) and SIP at <7 versus ≥7 days), sex, and intervention [Penrose Drain (PD) vs. laparotomy].

RESULTS

A total of 114 infants had NEC and 37 had SIP. On multinomial logistic regression, infants with NEC/SIP onset >20 days had significantly lower odds of small bowel involvement (aOR = 0.07, 95% CI: 0.01-0.33, p = 0.001), higher necrosis (aOR = 3.59, 95% CI: 1.34-9.65, p = 0.012) and higher CRP (p = 0.004) than onset <10 days. Initial laparotomy was associated with more bowel loss (24.1 cm [12.3; 40.6] vs.12.1 [8.00; 23.2]; p = 0.001), small and large intestine involvement (47.1% vs 17.2%; p = 0.01), and ileocecal valve resection (42% vs. 19.4%; p = 0.036) than initial PD therapy. Females underwent fewer small bowel resections (52.3% vs 73.6%; p = 0.025) but had higher surgical morbidity (53.7% vs. 24.7%.; p = 0.001) than males.

CONCLUSION

Clinical, radiological, and histopathological presentation and outcomes in preterm infants with surgical NEC/SIP are associated with age of disease onset, sex, and initial intervention.

IMPACT

Neonates with surgical NEC onset >20 days had more severe necrosis, inflammation, kidney injury, and bowel loss than those with <10 days. Initial laparotomy was associated with later age onset, more bowel loss, and ileocecal valve resection compared to initial PD treatment, but not with differences in mortality or length of stay. Female sex was associated with lower maturity, more placental malperfusion, less often small bowel involvement, lower pre-NEC hematocrit as well as higher surgical morbidity than males. Whether the management of surgical NEC and SIP should differ by the age of onset requires further investigation.

Complete Resection of Necrotic Bowel Improves Survival in NEC Without Compromising Enteral Autonomy

AIMS

Controversy persists regarding operative strategy for necrotising enterocolitis (NEC). Some surgeons advocate resecting all necrotic bowel, whilst others defunction with a stoma, leaving diseased bowel in situ to preserve bowel length. We reviewed our institutional experience of both approaches.

METHODS

Neonates undergoing laparotomy for NEC May 2015-2019 were identified. Data extracted from electronic records included: demographics, neonatal Sequential Organ Failure Assessment (nSOFA) score at surgery, operative findings, and procedure performed. Neonates were assigned to two groups according to operative strategy: complete resection of necrotic bowel (CR) or necrotic bowel left in situ (LIS). Primary outcome was survival, and secondary outcome was enteral autonomy. Outcomes were compared between groups.

RESULTS

Fifty neonates were identified. Six were excluded: 4 with NEC totalis and 2 with no visible necrosis or histological confirmation of NEC. Of the 44 remaining neonates, 27 were in the CR group and 17 in the LIS group. 32 neonates survived to discharge (73%). On univariate analysis, survival was associated with lower nSOFA score (P = 0.003), complete resection of necrotic bowel (OR 9.0, 95% CI [1.94-41.65]), and being born outside the surgical centre (OR 5.11 [1.23-21.28]). On Cox regression multivariate analysis, complete resection was still strongly associated with survival (OR 4.87 [1.51-15.70]). 28 of the 32 survivors (88%) achieved enteral autonomy. There was no association between operative approach and enteral autonomy (P = 0.373), or time to achieve this.

CONCLUSION

Complete resection of necrotic bowel during surgery for NEC significantly improves likelihood of surviving without negatively impacting remaining bowel function.

LEVEL OF EVIDENCE

III.

SNAPPE-II and MDAS scores as predictors for surgical intervention in very low birth weight neonates with necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is the most common life-threatening gastrointestinal emergency in preterm and term neonates, with the majority of cases affecting neonates classified as very low birth weight (VLBW, bw <1500 g). Scores for neonatal acute physiology-perinatal extension-II (SNAPPE-II) and metabolic derangement acuity score (MDAS) have been developed and utilized to assess neonatal morbidity and mortality including the subset of VLBW neonates. Serial SNAPPE-II and MDAS scores have been reported in neonates with necrotizing enterocolitis to assist in surgical management, yielding mixed results.

OBJECTIVE

To determine the relationship between clinical and/or laboratory deterioration using SNAPPE-II and MDAS scores measured at the time of NEC diagnosis and surgical management of NEC.

METHODS

We retrospectively evaluated preterm neonates ≥23 weeks gestational age who developed pneumatosis intestinalis on radiographic imaging coupled with clinical signs of NEC. SNAPPE-II and MDAS scores were calculated within twelve hours of birth and within twelve hours of initial finding of pneumatosis intestinalis. Baseline characteristics and clinical variables between those who did and did not require surgical intervention were compared. Logistic regression and receiver - operator characteristics (ROC) curve analyses were also performed, and areas under the curve (AUC) computed, to assess the performance of SNAPPE-II and MDAS scoring systems to differentiate neonates with NEC in the two groups.

RESULTS

Sixty-four neonates were evaluated in our study of which 20 required surgical management of NEC. While the baseline SNAPPE-II and MDAS scores did not differ between the surgical management and medical management only groups, when rescored within 12 h of NEC diagnosis, the surgical management group had significantly higher SNAPPE -II (38 (18.5-69) vs. 19 (10-34.5), p = .04) and MDAS (2.5 (1-3) vs. 1 (0-2), p = .0004) scores. The AUCs for MDAS 0.77 (95% CI 0.65-0.89 and 0.71 (95% CI 0.57-0.85) for SNAPPE-II, indicating an acceptable level of diagnostic ability of both scoring systems to differentiate between those who did and did not need surgical management.

CONCLUSION

SNAPPE II and MDAS scores performed within 12 h of NEC diagnosis may be useful in predicting which preterm VLBW neonates will require surgical intervention.

Effective alternatives for dietary interventions for necrotizing enterocolitis: a systematic review of in vivo studies

Necrotizing enterocolitis (NEC) is a significant cause of morbidity and mortality among neonates and low birth weight children in the United States. Current treatment options, such as antibiotics and intestinal resections, often result in complications related to pediatric nutrition and development. This systematic review aimed to identify alternative dietary bioactive compounds that have shown promising outcomes in ameliorating NEC in vivo studies conducted within the past six years. Following PRISMA guidelines and registering in PROSPERO (CRD42023330617), we conducted a comprehensive search of PubMed, Scopus, and Web of Science. Our analysis included 19 studies, predominantly involving in vivo models of rats (Rattus norvegicus) and mice (Mus musculus). The findings revealed that various types of compounds have demonstrated successful amelioration of NEC symptoms. Specifically, six studies employed plant phenolics, seven utilized plant metabolites/cytotoxic chemicals, three explored the efficacy of vitamins, and three investigated the potential of whole food extracts. Importantly, all administered compounds exhibited positive effects in mitigating the disease. These results highlight the potential of natural cytotoxic chemicals derived from medicinal plants in identifying and implementing powerful alternative drugs and therapies for NEC. Such approaches have the capacity to impact multiple pathways involved in the development and progression of NEC symptoms.

Time to first passage of meconium and defecation frequency preceding necrotizing enterocolitis in preterm infants: a case-control study

Necrotizing enterocolitis (NEC) is associated with significant morbidity and mortality in preterm infants. Early recognition and treatment of NEC are critical to improving outcomes. Enteric nervous system (ENS) immaturity has been proposed as a key factor in NEC pathophysiology. Gastrointestinal dysmotility is associated with ENS immaturity and may serve as a predictive factor for the development of NEC. In this case-control study, preterm infants (gestational age (GA) < 30 weeks) were included in two level-IV neonatal intensive care units. Infants with NEC in the first month of life were 1:3 matched to controls based on GA (± 3 days). Odds ratios for NEC development were analyzed by logistic regression for time to first passage of meconium (TFPM), duration of meconial stool, and mean daily defecation frequency over the 72 h preceding clinical NEC onset (DF < T0). A total of 39 NEC cases and 117 matched controls (median GA 27 + 4 weeks) were included. Median TFPM was comparable in cases and controls (36 h [IQR 13-65] vs. 30 h [IQR 9-66], p = 0.83). In 21% of both cases and controls, TFPM was ≥ 72 h (p = 0.87). Duration of meconial stool and DF < T0 were comparable in the NEC and control group (median 4 and 3, resp. in both groups). Odds of NEC were not significantly associated with TFPM, duration of meconial stools, and DF < T0 (adjusted odds ratio [95% confidence interval]: 1.00 [0.99-1.03], 1.16 [0.86-1.55] and 0.97 [0.72-1.31], resp.).

CONCLUSION

In this cohort, no association was found between TFPM, duration of meconium stool, and DF < T0 and the development of NEC.

WHAT IS KNOWN

• Necrotizing enterocolitis (NEC) is a life-threatening acute intestinal inflammatory disease of the young preterm infant. Early clinical risk factors for NEC have been investigated in order to facilitate early diagnosis and treatment. • Signs of disrupted gastrointestinal mobility, such as gastric retention and paralytic ileus, have been established to support the diagnosis of NEC. Nevertheless, defecation patterns have insufficiently been studied in relation to the disease.

WHAT IS NEW

• Defecation patterns in the three days preceding NEC did not differ from gestational age-matched controls of corresponding postnatal age. Additionally, the first passage of meconium and the duration of meconium passage were comparable between cases and controls. Currently, defecation patterns are not useful as early warning signs for NEC. It remains to be elucidated whether these parameters are different based on the location of intestinal necrosis.

Prediction of GutCheck NEC and Its Relation to Severity of Illness and Measures of Deterioration in Necrotizing Enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) risk has been shown to arise from multiple sources and risk awareness may be supported using bedside tools.

PURPOSE

The purpose of this research was to examine the extent to which GutCheck NEC was associated with scores for clinical deterioration, severity of illness, and clinical outcome, and further to examine how scores might improve NEC prediction.

METHODS

A retrospective, correlational case-control study with infant data from 3 affiliated neonatal intensive care units was conducted.

RESULTS

Of 132 infants (44 cases, 88 controls), most were 28 weeks of gestation at birth and less (74%). Median age at NEC onset was 18 days (range: 6-34 days), with two-thirds diagnosed before 21 days. At 68 hours of life, higher GutCheck NEC scores were associated with NEC requiring surgery or resulting in death (relative risk ratio [RRR] = 1.06, P = .036), associations that persisted at 24 hours prior to diagnosis (RRR = 1.05, P = .046), and at the time of diagnosis (RRR = 1.05, P = .022) but showed no associations for medical NEC. GutCheck NEC scores were significantly correlated with pediatric early warning scores (PEWS) ( r > 0.30; P < .005) and SNAPPE-II scores ( r > 0.44, P < .0001). Increasing numbers of clinical signs and symptoms were positively associated with GutCheck NEC and PEWS at the time of diagnosis ( r = 0.19, P = .026; and r = 0.25, P = .005, respectively).

IMPLICATIONS FOR PRACTICE AND RESEARCH

GutCheck NEC provides structure to streamline assessment and communication about NEC risk. Yet, it is not intended to be diagnostic. Research is needed on how GutCheck NEC impacts timely recognition and treatment.

Age of onset of necrotising enterocolitis (NEC) and focal intestinal perforation (FIP) in very preterm and low birthweight infants: a systematic review

OBJECTIVE

Review of age of onset of necrotising enterocolitis (NEC) and focal intestinal perforation (FIP) in very preterm (≤32 weeks) and/or very low birthweight (VLBW, ≤1500 g) infants.

DESIGN

Preregistered review undertaken according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses in July 2021 and updated October 2021.

DATA SOURCES

MEDLINE/ PubMed, Embase, CINAHL and Cochrane Central Register of Controlled Trials.

ELIGIBILITY

Eligible studies reported age of onset of NEC and/or FIP in randomised controlled trials of >200 or observational studies of >500 infants.

DATA EXTRACTION AND SYNTHESIS

Titles/abstracts were screened; eligible articles underwent data extraction. Age of onset as day of life (DOL) and/or corrected gestational age (CGA) were extracted alongside study information, such as NEC definition, included population, intervention, location and dates studied. Weighted means were used to compare onset by birth gestation, study type, NEC definition, trial intervention, location and dates studied. Comparison was done by Mann-Whitney U test or one-way analysis of variance.

RESULTS

Of the 747 screened studies 188 were eligible. Removal of duplicates, studies without onset data and ineligible populations left 10 RCTs and 14 observational studies contributing 51 NEC cohorts; 49 reported onset DOL and 14 CGA. 2984 cases of NEC had average DOL onset of 16.7 (15.5 in RCTs, 16.9 in observational studies), and CGA onset of 30.1 weeks. Gestation did not impact DOL onset. No other demographic feature impacted NEC onset. Few studies included data on FIP.

CONCLUSIONS

Average onset of NEC in exclusively very preterm/very low birthweight infants is in the third week of life and unlike in cohorts including more mature or heavier infants is not impacted by birth gestation.

[Recent research on machine learning in the diagnosis and treatment of necrotizing enterocolitis in neonates]

Necrotizing enterocolitis (NEC), with the main manifestations of bloody stool, abdominal distension, and vomiting, is one of the leading causes of death in neonates, and early identification and diagnosis are crucial for the prognosis of NEC. The emergence and development of machine learning has provided the potential for early, rapid, and accurate identification of this disease. This article summarizes the algorithms of machine learning recently used in NEC, analyzes the high-risk predictive factors revealed by these algorithms, evaluates the ability and characteristics of machine learning in the etiology, definition, and diagnosis of NEC, and discusses the challenges and prospects for the future application of machine learning in NEC.

State of the art review on machine learning and artificial intelligence in the study of neonatal necrotizing enterocolitis

Necrotizing Enterocolitis (NEC) is one of the leading causes of gastrointestinal emergency in preterm infants. Although NEC was formally described in the 1960's, there is still difficulty in diagnosis and ultimately treatment for NEC due in part to the multifactorial nature of the disease. Artificial intelligence (AI) and machine learning (ML) techniques have been applied by healthcare researchers over the past 30 years to better understand various diseases. Specifically, NEC researchers have used AI and ML to predict NEC diagnosis, NEC prognosis, discover biomarkers, and evaluate treatment strategies. In this review, we discuss AI and ML techniques, the current literature that has applied AI and ML to NEC, and some of the limitations in the field.

Application of comprehensive score of risk factors to determine the best time for surgical intervention in neonatal necrotizing enterocolitis

AIM

Necrotizing enterocolitis (NEC) is a severe digestive systemic disease. Surgery is critical treatment for NEC patients. However, it is still hard to predict the optimal timing of surgery. Our study aimed to explore the indicative effect of comprehensive risk factors method in surgical intervention in NEC patients.

METHODS

Retrospective analysis was made on newborns with NEC, who were divided into group I (patients with NEC conservative therapeutic approach or no necrosis or perforation found in NEC operation) and group II (patients with necrosis or perforation found in NEC operation or failure of NEC conservative approach). Clinical manifestations and complications were recorded and the risk factors scores were calculated. The receiver operating characteristic curve and Youden index were calculated.

RESULTS

One hundred and six NEC patients in Huizhou Central People's hospital were analysed. Significant difference was observed in the comprehensive scores of the two groups to judge the indications of NEC surgery. Among the risk factors of NEC surgery, the incidence specificity of abdominal induration, abdominal tenderness, hypotension and pneumoperitoneum was 100% in group II. The area under the curve of the comprehensive score of risk factors was 0.981 (95% confidence interval 0.958-1.000). The best cutoff value obtained by the maximum Youden index is 3.5 (sensitivity 97.2%; specificity 52.8%). When the specificity is 100%, the best interception value is 7.5 (sensitivity 91.4%; specificity 100%). Complications such as surgical intervention, mortality, stenosis after conservative treatment, perforation or necrosis during surgery were significantly different in different comprehensive scores.

CONCLUSIONS

Abdominal induration, abdominal tenderness, hypotension and pneumoperitoneum are independent predictors of NEC surgery. Comprehensive risk factors score may be a potentially useful clinical decision-making tool for NEC surgery.

IS -94INS/DELATTG POLYMORPHISM IN THE NUCLEAR FACTOR KAPPA-B1 GENE (NFKB1) ASSOCIATED WITH NECROTIZING ENTEROCOLITIS?

BACKGROUND

Abnormalities in the different stages of the intestinal maturation process cause metabolic and molecular changes. Among the genetic alterations associated with necrotizing enterocolitis, the -94ins/delATTG polymorphism in NFKB1 gene leads to unregulated activation of the NFKB protein due to an increase in the inherent pro-inflammatory state of the premature intestine.

AIMS

To determine the prevalence of the -94ins/delATTG polymorphism in NFKB1 gene in neonates with and without necrotizing enterocolitis.

METHODS

This is a case-control study, in which 25 neonates were evaluated as the case group and 50 neonates as the control group, of both genders. DNA was extracted from peripheral blood leukocytes, and the site encompassing the polymorphism was amplified by molecular techniques (polymerase chain reaction/polymorphism in restriction fragment length).

RESULTS

Necrotizing enterocolitis was diagnosed in 25 (33%) neonates and, of these, 3 (12%) died. Male gender was more prevalent in both groups (p=0.1613): cases (52%) and controls (62%). Moderate and extreme preterm newborns were predominant in both groups: cases (80%) and controls (88%) (p=0.3036). Low birth weight and extremely low birth weight newborns were the most prevalent in cases (78%), and very low birth weight and extremely low birth weight were the most prevalent in controls (81%) (p=0.1073). Clinical treatment was successful in 72%, and hospital discharge was achieved in 88% of newborns with NEC. The -94ins/delATTG polymorphism in NFKB1 gene was not identified in all the 150 alleles analyzed (100%).

CONCLUSIONS

The absence of the -94ins/delATTG polymorphism in NFKB1 gene in newborns with and without necrotizing enterocolitis does not rule out the possibility of alterations in this and/or in other genes in newborns with this condition, which reinforces the need for further research.

Noninvasive Fecal Cytokine and Microbiota Profiles Predict Commencement of Necrotizing Enterocolitis in a Proof-of-Concept Study

Background and Aims

Necrotizing enterocolitis (NEC) is a life-threatening disease and the most common gastrointestinal emergency in premature infants. Accurate early diagnosis is challenging. Modified Bell's staging is routinely used to guide diagnosis, but early diagnostic signs are nonspecific, potentially leading to unobserved disease progression, which is problematic given the often rapid deterioration observed. We investigated fecal cytokine levels, coupled with gut microbiota profiles, as a noninvasive method to discover specific NEC-associated signatures that can be applied as potential diagnostic markers.

Methods

Premature babies born below 32 weeks of gestation were admitted to the 2-site neonatal intensive care unit (NICU) of Imperial College hospitals (St. Mary's or Queen Charlotte's & Chelsea) between January 2011 and December 2012. During the NICU stay, expert neonatologists grouped individuals by modified Bell's staging (healthy, NEC1, NEC2/3) and fecal samples from diapers were collected consecutively. Microbiota profiles were assessed by 16S rRNA gene amplicon sequencing and cytokine concentrations were measured by V-Plex multiplex assays.

Results

Early evaluation of microbiota profiles revealed only minor differences. However, at later time points, significant changes in microbiota composition were observed for Bacillota (adj. P = .0396), with Enterococcus being the least abundant in Bell stage 2/3 NEC. Evaluation of fecal cytokine levels revealed significantly higher concentrations of IL-1α (P = .045), IL-5 (P = .0074), and IL-10 (P = .032) in Bell stage 1 NEC compared to healthy individuals.

Conclusion

Differences in certain fecal cytokine profiles in patients with NEC indicate their potential use as diagnostic biomarkers to facilitate earlier diagnosis. Additionally, associations between microbial and cytokine profiles contribute to improving knowledge about NEC pathogenesis.

Artificial intelligence in the diagnosis of necrotising enterocolitis in newborns

Necrotising enterocolitis (NEC) is one of the most common diseases in neonates and predominantly affects premature or very-low-birth-weight infants. Diagnosis is difficult and needed in hours since the first symptom onset for the best therapeutic effects. Artificial intelligence (AI) may play a significant role in NEC diagnosis. A literature search on the use of AI in the diagnosis of NEC was performed. Four databases (PubMed, Embase, arXiv, and IEEE Xplore) were searched with the appropriate MeSH terms. The search yielded 118 publications that were reduced to 8 after screening and checking for eligibility. Of the eight, five used classic machine learning (ML), and three were on the topic of deep ML. Most publications showed promising results. However, no publications with evident clinical benefits were found. Datasets used for training and testing AI systems were small and typically came from a single institution. The potential of AI to improve the diagnosis of NEC is evident. The body of literature on this topic is scarce, and more research in this area is needed, especially with a focus on clinical utility. Cross-institutional data for the training and testing of AI algorithms are required to make progress in this area. IMPACT: Only a few publications on the use of AI in NEC diagnosis are available although they offer some evidence that AI may be helpful in NEC diagnosis. AI requires large, multicentre, and multimodal datasets of high quality for model training and testing. Published results in the literature are based on data from single institutions and, as such, have limited generalisability. Large multicentre studies evaluating broad datasets are needed to evaluate the true potential of AI in diagnosing NEC in a clinical setting.

Prospective observational study of the challenges in diagnosing common neonatal conditions in Nigeria and Kenya

OBJECTIVES

Accurate and timely diagnosis of common neonatal conditions is crucial for reducing neonatal deaths. In low/middle-income countries with limited resources, there is sparse information on how neonatal diagnoses are made. The aim of this study was to describe the diagnostic criteria used for common conditions in neonatal units (NNUs) in Nigeria and Kenya.

DESIGN

Prospective observational study. Standard case report forms for suspected sepsis, respiratory disorders, birth asphyxia and abdominal conditions were co-developed by the Neonatal Nutrition Network (https://www.lstmed.ac.uk/nnu) collaborators. Clinicians completed forms for all admissions to their NNUs. Key data were displayed using heatmaps.

SETTING

Five NNUs in Nigeria and two in Kenya comprising the Neonatal Nutrition Network.

PARTICIPANTS

2851 neonates, which included all neonates admitted to the seven NNUs over a 6-month period.

RESULTS

1230 (43.1%) neonates had suspected sepsis, 874 (30.6%) respiratory conditions, 587 (20.6%) birth asphyxia and 71 (2.5%) abdominal conditions. For all conditions and across all NNUs, clinical criteria were used consistently with sparse use of laboratory and radiological criteria.

CONCLUSION

Our findings highlight the reliance on clinical criteria and extremely limited use of diagnostic technologies for common conditions in NNUs in sub-Saharan Africa. This has implications for the management of neonatal conditions which often have overlapping clinical features. Strategies for implementation of diagnostic pathways and investment in affordable and sustainable diagnostics are needed to improve care for these vulnerable infants.

Intra-Amniotic Administration-An Emerging Method to Investigate Necrotizing Enterocolitis, In Vivo (Gallus gallus)

Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease in premature infants and a leading cause of death in neonates (1-7% in the US). NEC is caused by opportunistic bacteria, which cause gut dysbiosis and inflammation and ultimately result in intestinal necrosis. Previous studies have utilized the rodent and pig models to mimic NEC, whereas the current study uses the in vivo (Gallus gallus) intra-amniotic administration approach to investigate NEC. On incubation day 17, broiler chicken (Gallus gallus) viable embryos were injected intra-amniotically with 1 mL dextran sodium sulfate (DSS) in H₂O. Four treatment groups (0.1%, 0.25%, 0.5%, and 0.75% DSS) and two controls (H₂O/non-injected controls) were administered. We observed a significant increase in intestinal permeability and negative intestinal morphological changes, specifically, decreased villus surface area and goblet cell diameter in the 0.50% and 0.75% DSS groups. Furthermore, there was a significant increase in pathogenic bacterial (E. coli spp. and Klebsiella spp.) abundances in the 0.75% DSS group compared to the control groups, demonstrating cecal microbiota dysbiosis. These results demonstrate significant physiopathology of NEC and negative bacterial-host interactions within a premature gastrointestinal system. Our present study demonstrates a novel model of NEC through intra-amniotic administration to study the effects of NEC on intestinal functionality, morphology, and gut microbiota in vivo.

Proteomics Profiling of Stool Samples from Preterm Neonates with SWATH/DIA Mass Spectrometry for Predicting Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a life-threatening condition for premature infants in neonatal intensive care units. Finding indicators that can predict NEC development before symptoms appear would provide more time to apply targeted interventions. In this study, stools from 132 very-low-birth-weight (VLBW) infants were collected daily in the context of a multi-center prospective study aimed at investigating the potential of fecal biomarkers for NEC prediction using proteomics technology. Eight of the VLBW infants received a stage-3 NEC diagnosis. Stools collected from the NEC infants up to 10 days before their diagnosis were available for seven of them. Their samples were matched with those from seven pairs of non-NEC controls. The samples were processed for liquid chromatography-tandem mass spectrometry analysis using SWATH/DIA acquisition and cross-compatible proteomic software to perform label-free quantification. ROC curve and principal component analyses were used to explore discriminating information and to evaluate candidate protein markers. A series of 36 proteins showed the most efficient capacity with a signature that predicted all seven NEC infants at least a week in advance. Overall, our study demonstrates that multiplexed proteomic signature detection constitutes a promising approach for the early detection of NEC development in premature infants.

Bedside Ultrasound for Early Diagnosis of Necrotizing Enterocolitis: A Pilot Study

OBJECTIVE

 This study aimed to assess whether bedside ultrasound (BUS) as the first imaging modality allows an earlier diagnosis of necrotizing enterocolitis (NEC) compared with abdominal radiography.

STUDY DESIGN

 A before-after controlled study in preterm infants with suspected NEC. The intervention group (October 2019-October 2021) received BUS as the first imaging modality and was managed accordingly to BUS findings. The control group (October 2015-September 2019) received radiography as the first imaging modality. The main outcome was NEC confirmation at the time of initial imaging. Secondary outcomes included time to diagnosis, laboratory data, and treatment requirements.

RESULTS

 Thirty-five episodes of suspected NEC with 14 (40%) confirmed NEC cases and 49 episodes of suspected NEC with 22 (44.9%) confirmed NEC cases were included in the intervention and control groups, respectively. In the intervention group, 11 of 14 (78.6%) NEC cases were confirmed at initial evaluation compared with 5 of 22 (22.7%) in the control group (p = 0.001). Infants in the intervention group developed thrombocytopenia and coagulopathy less frequently, were exposed to less radiation, and required less days of parenteral nutrition compared with the control group (p < 0.05).

CONCLUSION

 The use of BUS as the first imaging modality allowed an earlier diagnosis and timely treatment of NEC compared with abdominal radiography.Key Points · This is the first study that has assessed the role of BUS as the first imaging modality in NEC.. · BUS improves early diagnosis of NEC compared with abdominal radiography.. · BUS shortens time to NEC confirmation and treatment initiation which may reduce clinical severity of the NEC episode..

Spontaneous intestinal perforation (SIP) will soon become the most common form of surgical bowel disease in the extremely low birth weight (ELBW) infant

Recent data have revealed declines in the prevalence rates of NEC over the last decade in premature infants. In contrast, SIP has either remained steady or risen during the same epoch. These trends are consistent with our knowledge of the clinical arena. The ability to discern SIP contamination within NEC datasets has slowly improved. Additionally, quality improvement efforts are being utilized to reduce NEC through stewardship of antibiotics, acid inhibitors, central lines and blood products, as well as optimization of human milk diets. These forces are moving us to a new era, where NEC will no longer be the dominant surgical intestinal disease of the extremely preterm neonate. Indeed, in the extremely low birth weight (ELBW) population, SIP may already be the most prevalent reason for abdominal surgery. In this perspective, the reader will find supporting data and references for these assertions as well as predictions for the future.

A critical evaluation of current definitions of necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is a devastating intestinal disease of premature infants, with significant mortality and long-term morbidity among survivors. Multiple NEC definitions exist, but no formal head-to-head evaluation has been performed. We hypothesized that contemporary definitions would perform better in evaluation metrics than Bell's and range features would be more frequently identified as important than yes/no features.

METHODS

Two hundred and nineteen patients from the University of Iowa hospital with NEC, intestinal perforation, or NEC concern were identified from a 10-year retrospective cohort. NEC presence was confirmed by a blinded investigator. Evaluation metrics were calculated using statistics and six supervised machine learning classifiers for current NEC definitions. Feature importance evaluation was performed on each decision tree classifier.

RESULTS

Newer definitions outperformed Bell's staging using both standard statistics and most machine learning classifiers. The decision tree classifier had the highest overall machine learning scores, which resulted in Non-Bell definitions having high sensitivity (0.826, INC) and specificity (0.969, ST), while Modified Bell (IIA+) had reasonable sensitivity (0.783), but poor specificity (0.531). Feature importance evaluation identified nine criteria as important for diagnosis.

CONCLUSIONS

This preliminary study suggests that Non-Bell NEC definitions may be better at diagnosing NEC and calls for further examination of definitions and important criteria.

IMPACT

This article is the first formal head-to-head evaluation of current available definitions of NEC. Non-Bell NEC definitions may be more effective in identifying NEC based on findings from traditional measures of diagnostic performance and machine learning techniques. Nine features were identified as important for diagnosis from the definitions evaluated within the decision tree when performing supervised classification machine learning. This article serves as a preliminary study to formally evaluate the definitions of NEC utilized and should be expounded upon with a larger and more diverse patient cohort.

Imaging for Diagnosis and Assessment of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is inflammatory bowel necrosis of preterm and critically ill infants. The disease is seen in 6-10% of preterm infants who weigh less than 1500 g at birth and carries considerable morbidity, mortality, and healthcare cost burden. Efforts focused on timely mitigation remain restricted due to challenges in early diagnosis as clinical features, and available laboratory tests remain nonspecific until late in the disease. There is renewed interest in the radiological and sonographic assessment of intestinal diseases due to technological advances making them safe, cost-efficient, and supporting Web-based transmission of images, thereby reducing time to diagnosis by disease experts. Most of our experience has been with plain abdominal radiography, which shows characteristic features such as pneumatosis intestinalis in up to 50-60% of patients. Many patients with advanced disease may also show features such as portal venous gas and pneumoperitoneum. Unfortunately, these features are not seen consistently in patients with early, treatable conditions, and hence, there has been an unfulfilled need for additional imaging modalities. In recent years, abdominal ultrasound (AUS) has emerged as a readily available, noninvasive imaging tool that may be a valuable adjunct to plain radiographs for evaluating NEC. AUS can allow real-time assessment of vascular perfusion, bowel wall thickness, with higher sensitivity in detecting pneumatosis, altered peristalsis, and characteristics of the peritoneal fluid. Several other modalities, such as contrast-enhanced ultrasound (CEUS), magnetic resonance imaging (MRI), and near-infrared spectroscopy (NIRS), are also emerging. In this article, we have reviewed the available imaging options for NEC evaluation.

Lipocalin-2 and calprotectin as stool biomarkers for predicting necrotizing enterocolitis in premature neonates

BACKGROUND

Necrotizing enterocolitis (NEC) is a major challenge for premature infants in neonatal intensive care units and efforts toward the search for indicators that could be used to predict the development of the disease have given limited results until now.

METHODS

In this study, stools from 132 very low birth weight infants were collected daily in the context of a multi-center prospective study aimed at investigating the potential of fecal biomarkers for NEC prediction. Eight infants (~6%) received a stage 3 NEC diagnosis. Their stools collected up to 10 days before diagnosis were included and matched with 14 non-NEC controls and tested by ELISA for the quantitation of eight biomarkers.

RESULTS

Biomarkers were evaluated in all available stool samples leading to the identification of lipocalin-2 and calprotectin as the two most reliable predicting markers over the 10-day period prior to NEC development. Pooling the data for each infant confirmed the significance of lipocalin-2 and calprotectin, individually and in combination 1 week in advance of the NEC clinical diagnosis.

CONCLUSIONS

The lipocalin-2 and calprotectin tandem represents a significant biomarker signature for predicting NEC development. Although not yet fulfilling the "perfect biomarker" criteria, it represents a first step toward it.

IMPACT

Stool biomarkers can be used to predict NEC development in very low birth weight infants more than a week before the diagnosis. LCN2 was identified as a new robust biomarker for predicting NEC development, which used in conjunction with CALPRO, allows the identification of more than half of the cases that will develop NEC in very low birth weight infants. Combining more stool markers with the LCN2/CALPRO tandem such as PGE2 can further improve the algorithm for the prediction of NEC development.

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

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

Metabolic model of necrotizing enterocolitis in the premature newborn gut resulting from enteric dysbiosis

Necrotizing enterocolitis (NEC) is a leading cause of premature newborn morbidity and mortality. The clinical features of NEC consistently include prematurity, gut dysbiosis and enteral inflammation, yet the pathogenesis remains obscure. Herein we combine metagenomics and targeted metabolomics, with functional in vivo and in vitro assessment, to define a novel molecular mechanism of NEC. One thousand six hundred and forty seven publicly available metagenomics datasets were analyzed (NEC = 245; healthy = 1,402) using artificial intelligence methodologies. Targeted metabolomic profiling was used to quantify the concentration of specified fecal metabolites at NEC onset (n = 8), during recovery (n = 6), and in age matched controls (n = 10). Toxicity assays of discovered metabolites were performed in vivo in mice and in vitro using human intestinal epithelial cells. Metagenomic and targeted metabolomic analyses revealed significant differences in pyruvate fermentation pathways and associated intermediates. Notably, the short chain fatty acid formate was elevated in the stool of NEC patients at disease onset (P = 0.005) dissipated during recovery (P = 0.02) and positively correlated with degree of intestinal injury (r ² = 0.86). In vitro, formate caused enterocyte cytotoxicity in human cells through necroptosis (P < 0.01). In vivo, luminal formate caused significant dose and development dependent NEC-like injury in newborn mice. Enterobacter cloacae and Klebsiella pneumoniae were the most discriminatory taxa related to NEC dysbiosis and increased formate production. Together, these data suggest a novel biochemical mechanism of NEC through the microbial production of formate. Clinical efforts to prevent NEC should focus on reducing the functional consequences of newborn gut dysbiosis associated metabolic pathways.

Impacts of Enriched Human Milk Cells on Fecal Metabolome and Gut Microbiome of Premature Infants with Stage I Necrotizing Enterocolitis: A Pilot Study

SCOPE

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in preterm infants, occurring more often in formula-fed infants than in breastfed infants. Recent animal studies have shown that cells in fresh breast milk survive in the newborns' digestive tract. However, no clinical studies have been conducted on the effects of human milk cells, and their biological roles in the infants' intestines remain unexplored.

METHODS AND RESULTS

Twenty premature infants are enrolled. Cells from fresh milk of their own mothers are enriched and fed to infants with Bell's Stage I NEC once a day for 7 days since the onset of NEC. Fecal samples are collected at enrollment and 2 weeks later. Fecal sphingolipids are observed to be enriched in NEC patients and positively correlated with calprotectin levels. After intervention with enriched human milk cells, inflammation-associated sphingolipids and microbiome profiles are altered and resembled those of the controls.

CONCLUSION

These preliminary findings reveal the potential impacts of enriched human milk cells on premature infants with Bell's Stage I NEC and provide insight into the roles of fecal sphingolipid metabolism in the neonates' intestinal inflammation. However, the limited sample size of the study indicates the need for further investigation.

Oxidative Stress in Preterm Newborns

Preterm babies are highly susceptible to oxidative stress (OS) due to an imbalance between the oxidant and antioxidant systems. The generation of free radicals (FR) induces oxidative damage to multiple body organs and systems. OS is the main factor responsible for the development of typical premature infant diseases, such as bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, intraventricular hemorrhage, periventricular leukomalacia, kidney damage, eryptosis, and also respiratory distress syndrome and patent ductus arteriosus. Many biomarkers have been detected to early identify newborns at risk of developing a free radical-mediated disease and to investigate new antioxidant strategies. This review reports the current knowledge on OS in the preterm newborns and the newest findings concerning the use of OS biomarkers as diagnostic tools, as well as in implementing antioxidant therapeutic strategies for the prevention and treatment of these diseases and their sequelae.

IL-27 as a potential biomarker for distinguishing between necrotising enterocolitis and highly suspected early-onset food protein-induced enterocolitis syndrome with abdominal gas signs

Background

The initial clinical manifestations and abdominal imaging findings of neonates with necrotising enterocolitis (NEC) and food protein-induced enterocolitis syndrome (FPIES) are sometimes similar; however, their prognosis and therapies are different. We aimed to evaluate the utility of interleukin (IL)-27 as a differentiation marker between NEC and highly suspected early onset (HSEO)-FPIES.

Methods

All samples used in this study were obtained from the neonatal diagnosis centre of Children's Hospital of Chongqing Medical University. In the case-control study, neonates with NEC (n = 13), HSEO-FPIES (n = 9), and jaundice (control, n = 8) were enroled to determine the serum IL-27 levels using commercial enzyme-linked immunosorbent assay (ELISA) kits. In the validation cohort study, the NEC (n = 87), HSEO-FPIES (n = 62), and jaundice (control, n = 54) groups were included to analyse the diagnostic efficiency of IL-27 for discriminating between NEC and HSEO-FPIES using a receiver operating characteristic (ROC) curve.

Findings

In the case-control study, IL-27 levels were higher in the NEC group than in the HSEO-FPIES group (p = 0·005). In the cohort study, the area under the ROC curve (AUC) of IL-27 for differentiating NEC from HSEO-FPIES was 0·878, which was higher than the AUCs of IL-6 (0·761), C-reactive protein (0·800), white blood cell count (0·637), neutrophils (0·765), lymphocytes (0·782), neutrophil to lymphocyte ratio (0·781), and platelet count (0·729).

Interpretation

Serum IL-27 is a novel biomarker that may potentially discriminate NEC from HSEO-FPIES in neonates.

Clinical Presentation and Multifactorial Pathogenesis of Necrotizing Enterocolitis in the Preterm Infant

BACKGROUND

Necrotizing enterocolitis (NEC) is a serious infection of the bowel wall induced by multiple pathological factors, which include inflammation and tissue invasion with bacteria known to cause severe infections. NEC is now understood to be several disease processes under one umbrella. The most common form occurs in premature infants and can exert significant impacts to preterm morbidity and mortality.

PURPOSE

This narrative review describes current knowledge of the clinical presentation and pathophysiology of NEC in premature infants.

METHODS/SEARCH STRATEGY

A review of literature was conducted using key words in PubMed and CINAHL with preference for years 2015 to 2020.

FINDINGS/RESULTS

Several converging and interrelated factors including characteristics of the premature intestinal mucosa, gut ischemia, dysregulation of the microbiome, enteral feeding, and genetics create an environment where NEC is more likely to occur.

IMPLICATIONS FOR PRACTICE

To recognize and diagnose NEC in preterm infants, an understanding of underlying factors that create an optimal environment for disease acquisition in premature infants is essential.

IMPLICATIONS FOR RESEARCH

Prevention of NEC remains the most important strategy for decreasing morbidity and mortality. Multiple areas of potential study exist for NEC pathophysiology including those that consider how the factors discussed in this review are interrelated and how each particular pathway can be optimized to prevent the onset of NEC.

Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is an inflammatory disease affecting premature infants. Intestinal microbial composition may play a key role in determining which infants are predisposed to NEC and when infants are at highest risk of developing NEC. It is unclear how to optimize antibiotic therapy in preterm infants to prevent NEC and how to optimize antibiotic regimens to treat neonates with NEC. This article discusses risk factors for NEC, how dysbiosis in preterm infants plays a role in the pathogenesis of NEC, and how probiotic and antibiotic therapy may be used to prevent and/or treat NEC and its sequelae.

The assessment of microbiome changes and fecal volatile organic compounds during experimental necrotizing enterocolitis

INTRODUCTION

Necrotizing enterocolitis (NEC) remains a devastating disease that affects the gastrointestinal tract of the preterm infant. Volatile organic compounds (VOCs) have emerged as a non-invasive biomarker in many diseases. We hypothesized that fecal VOC profiles would be significantly different between control and NEC pups in a NEC mouse model.

METHODS

Experimental NEC was induced in five-day-old mice. Breastfed and formula-fed control groups were also studied. After four days, pups were euthanized and intestines were H&E stained and blindly scored. Stool microbiome analysis was performed via 16S rRNA sequencing. VOC analysis was assessed by the Cyranose^Ⓡ 320 eNose device and p<0.05 was significant.

RESULTS

NEC pups had severe intestinal injury when compared to controls. Microbiome analysis showed that both control groups had significantly higher microbial diversity and relative abundance of Lactobacillus than NEC, and lower relative abundance of Escherichia. Fecal VOC profile for NEC pups was significantly different from controls.

CONCLUSIONS

Experimental NEC was associated with intestinal dysbiosis. Fecal VOC analysis by the Cyranose^Ⓡ 320 eNose device can discriminate NEC pups from both breastfed and formula-fed controls. Further research is warranted to establish whether fecal VOCs can be used as a biomarker or predictive algorithm to diagnose NEC.

Neurodevelopmental and Growth Outcomes of Extremely Preterm Infants with Short Bowel Syndrome

OBJECTIVE

To determine if preterm infants with surgical necrotizing enterocolitis (sNEC) or spontaneous intestinal perforation (SIP) with short bowel syndrome (SBS) have worse neurodevelopmental and growth outcomes than those with sNEC/SIP without SBS, and those with no necrotizing enterocolitis, SIP, or SBS.

STUDY DESIGN

We undertook a retrospective analysis of prospectively collected data from infants born between 22 and 26 weeks of gestation in the National Institute of Child Health and Human Development Neonatal Research Network centers from January 1, 2008, to December 31, 2016. Survivors were assessed at 18-26 months corrected age by standardized neurologic examination and Bayley Scales of Infant and Toddler Development, Third Edition. The primary outcome was moderate-severe neurodevelopmental impairment. Growth was assessed using World Health Organization z-score standards. Adjusted relative risks were estimated using modified Poisson regression models.

RESULTS

Mortality was 32%, 45%, and 21% in the 3 groups, respectively. Eighty-nine percent of survivors were seen at 18-26 months corrected age. Moderate-severe neurodevelopmental impairment was present in 77% of children with SBS compared with 62% with sNEC/SIP without SBS (adjusted relative risk, 1.22; 95% CI, 1.02-1.45; P = .03) and 44% with no necrotizing enterocolitis, SIP, or SBS (adjusted relative risk, 1.60; 95% CI, 1.37-1.88; P < .001). Children with SBS had lowcognitive, language, and motor scores than children with sNEC/SIP without SBS. At follow-up, length and head circumference z-scores remained more than 1 SD below the mean for children with SBS.

CONCLUSIONS

Preterm infants with sNEC/SIP and SBS had increased risk of adverse neurodevelopmental outcomes at 18-26 months corrected age and impaired growth compared with peers with sNEC/SIP without SBS or without any of these conditions.

TFF3 mediates the NF-κB/COX2 pathway to regulate PMN-MDSCs activation and protect against necrotizing enterocolitis

Intestinal trefoil factor 3 (TFF3) plays an important role in repairing the intestinal mucosa. However, the detailed mechanism regarding immune regulation by TFF3 is not well defined. Here, we reported that treatment of mouse BM cells and human peripheral blood mononuclear cells from healthy volunteers with TFF3 activated polymorphnuclear myeloid-derived suppressor cells (PMN-MDSCs) in vitro. We also found that prostaglandin E2 is a major TFF3-mediated MDSC target, and that NF-κB/COX2 signaling was involved in this process. Moreover, TFF3 treatment or transfer of TFF3-derived PMN-MDSCs (TFF3-MDSCs) to experimental necrotizing enterocolitis (NEC) mice caused PMN-MDSC accumulation in the lamina propria (LP), which was associated with decreased intestinal inflammation, permeability, bacterial loading, and prolonged survival. Interestingly, no NEC severity remission was observed in Rag1 KO mice that were given TFF3-MDSCs, but coinjection with CD4⁺ T cells significantly relieved NEC inflammation. Overall, TFF3 mediates the NF-κB/COX2 pathway to regulate PMN-MDSC activation and attenuates NEC in a T-cell-dependent manner, which suggests a novel mechanism in preventing NEC occurrence.

Faecal calprotectin and gut microbiota do not predict enteropathy in very preterm infants

Aim

Very preterm birth is associated with a high risk of enteropathies. Diagnosis is challenging, especially in mild forms, leading to unnecessary periods of cessation of enteral feeding. This study aimed at establishing a prognosis score of enteropathy combining clinical parameters and faecal calprotectin concentration.

Methods

This prospective multicentric study included preterm neonates born at a gestational age of 33 weeks or less. Stools were collected weekly until hospital discharge, and daily in case of digestive events for calprotectin measurement (ELISA and immunochromatography) and microbiota analyses (16S rRNA gene sequencing).

Results

Among the 121 neonates included, 21 experienced at least one episode of enteropathy, mainly mild forms. By ELISA testing, median faecal calprotectin was 88 (8‐798) µg/g faeces. No statistically significant association was found between the outset of enteropathy and maternal and neonatal characteristics, and calprotectin levels. The agreement between ELISA and immunochromatography assay was moderate (intra‐class correlation coefficient 0.58, 95%CI [0.47‐0.66]). Comparison of species diversity and relative bacterial abundance profiles between infants with or without enteropathy revealed no specific alterations associated with enteropathy.

Conclusion

The study failed to propose a prognostic score of enteropathy, probably due the large inter‐ and intra‐individual variability of faecal calprotectin in very preterm neonates.

Association Between Platelet-to-Lymphocyte Ratio and Preterm Necrotizing Enterocolitis

Introduction: Necrotizing enterocolitis (NEC) is a fatal condition for very-low-birth-weight infants. Necrotizing enterocolitis is a multi-factor phenomenon that results in intestinal mucosal damage and leads to intestinal necrosis. However, sensitive laboratory indicators for NEC are lacking, making early diagnosis difficult. This study aimed to explore the relationship between the platelet-to-lymphocyte ratio (PLR) and NEC in preterm neonates to enable an earlier diagnosis of the condition. Methods: This was a retrospective case-control study of preterm neonates diagnosed with NEC between January 2018 and December 2019 in the West China Second University Hospital. Controls were selected from preterm neonatal intensive care unit (NICU) graduates, and they were matched for gestation and year of birth to the preterms diagnosed without NEC. In total, 93 and 107 infants were included in the NEC and control groups, respectively. Empowerstats analysis was used to identify the association between PLR and preterm NEC. Results: The NEC group had significantly higher PLR levels than the control group. PLR > 100 within 1 week before NEC diagnosis was a risk factor for NEC. There was a positive connection between PLR and preterm NEC. A PLR of >100 was determined as the optimal cutoff for predicting preterm NEC, with patients with PLR >100 having a higher risk of NEC [odds ratio (OR): 18.82 (95% confidence interval (CI): 2.93-120.98), p = 0.002]. Conclusions: A PLR of >100 within 1 week after clinical abnormalities is associated with a high risk of NEC in preterm neonates.

Time of Onset of Necrotizing Enterocolitis and Focal Perforation in Preterm Infants: Impact on Clinical, Surgical, and Histological Features

Objective: There is no gold standard test for diagnosis of necrotizing enterocolitis (NEC). Timing of onset is used in some definitions and studies in an attempt to separate NEC from focal intestinal perforation (FIP) with 14 days used as a cutoff. In a large, detailed data set we aimed to compare NEC and FIP in preterm infants born <32 weeks gestation, presenting before 14 days of life in comparison to cases presenting later. Design: Infants with NEC or FIP when parents had consented to enrollment in an observational and sample collection study were included from 2009 to 2019. Clinical, surgical, histological, and outcome data were extracted and reviewed by each author independently. Patients/Episodes: In 785 infants, 174 episodes of NEC or FIP were identified of which 73 (42%) occurred before 14 days, including 54 laparotomies and 19 episodes of medically managed NEC ("early"). There were 56 laparotomies and 45 episodes of medically managed NEC presenting on or after 14 days age ("late"). Results: In early cases, 41% of laparotomies were for NEC (22 cases) and 59% for FIP (32 cases), and in late cases, 91% of laparotomies (51 cases) were for NEC and 9% (five cases) were for FIP. NEC presenting early was more likely to present with an initial septic presentation rather than discrete abdominal pathology and less likely to have clear pneumatosis. Early cases did not otherwise differ clinically, surgically, or histologically or in outcomes compared with later cases. FIP features did not differ by age at presentation. Conclusions: Although most FIP occurred early, 14% occurred later, whereas almost one third (29%) of NEC cases (surgical and medical) presented early. Infant demographics and surgical and histological findings of early- and late-presenting disease did not differ, suggesting that early and late cases are not necessarily different subtypes of the same disease although a common pathway of different pathogenesis cannot be excluded. Timing of onset does not accurately distinguish NEC from FIP, and caution should be exercised in including timing of onset in diagnostic criteria.

The Role of Human Milk in Decreasing Necrotizing Enterocolitis Through Modulation of the Infant Gut Microbiome: A Scoping Review

BACKGROUND

Necrotizing enterocolitis is associated with a high incidence of morbidity and mortality in premature infants. Human milk minimizes necrotizing enterocolitis risk, although the mechanism of protection is not thoroughly understood. Increasingly, dysbiosis of the infant gut microbiome, which is affected by infant diet, is hypothesized to play a role in necrotizing enterocolitis pathophysiology.

RESEARCH AIM

The aim of this scoping review was to summarize the state of the science regarding the hypothesis that the gut microbiome composition is a mediator of the relationship between human milk and decreased incidence of necrotizing enterocolitis within a sample of human infants.

METHODS

Electronic databases and reference lists were searched for peer-reviewed primary research articles addressing the link between human milk, gut microbiome composition, and subsequent incidence of necrotizing enterocolitis among human infants.

RESULTS

A total of four studies met criteria for inclusion in this review. Of these, evidence supporting the link between human milk, gut microbiome composition, and necrotizing enterocolitis was found in two (50%) studies.

CONCLUSION

Some evidence linking all three variables is provided in this review. Given the small number of available studies, and the limitations of those studies, more research is urgently needed to thoroughly understand the protection against necrotizing enterocolitis gained through the provision of human milk.

Hope on the horizon: promising novel therapies for necrotizing enterocolitis

Necrotizing enterocolitis (NEC) remains among the most common and devastating diseases in neonates. Despite advances in neonatal clinical care, specific treatment strategies and diagnostic modalities remain lacking. As a result, morbidity and mortality remain high. Improved understanding of the pathogenesis of NEC has the potential for improved therapeutics. Some of the areas of research leading to promising discoveries include inhibition of Toll-like receptor signaling, modulation of vascular endothelial growth factor signal pathways, defining metabolomic alterations in NEC to discover potential biomarkers, probing for genetic predispositions to NEC susceptibility, determining mechanistic relations between anemia and NEC, and microflora modulation through the use of probiotics. All of these areas may represent novel promising approaches to the prevention and treatment of NEC. This review will focus on these current and possible therapeutic perspectives.

Challenges in diagnosing necrotizing enterocolitis

One of the many challenges with necrotizing enterocolitis (NEC) remains our inability to make an accurate diagnosis of NEC. The lack of a unifying cause and multiple variations in presentations lead to great uncertainty with NEC. Separating out the needs of the researcher wanting to define NEC from the clinician and patient family's perspectives who want an accurate diagnosis for NEC is important. The need to augment and/or replace the outdated modified Bell staging criteria is crucial to improving NEC management. Emerging literature suggests that genetic susceptibility and stool microbiota signatures may help identify preterm infants at increased risk of the disease. Ongoing studies using single or multi-omic approaches may help to characterize biomarkers that will aid in the prediction or early diagnosis of NEC, as well as differentiate other causes of severe bowel injury. Bowel ultrasound shows promise in improving our diagnostic accuracy for NEC but has been slow in adoption. Patient family perspectives are key in accelerating our efforts to integrate newer diagnostic methods into practice.

Defining necrotizing enterocolitis: current difficulties and future opportunities

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in hospitalized infants. First classified through Bell staging in 1978, a number of additional definitions of NEC have been proposed in the subsequent decades. In this review, we summarize eight current definitions of NEC, and explore similarities and differences in clinical signs and radiographic features included within these definitions, as well as their limitations. We highlight the importance of a global consensus on defining NEC to improve NEC research and outcomes, incorporating input from participants at an international NEC conference. We also highlight the important role of patient-families in helping to redefine NEC.

Precision-based modeling approaches for necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the leading cause of death from gastrointestinal disease in premature infants and remains stubbornly difficult to treat in many cases. Much of our understanding of NEC pathogenesis has been gained through the study of highly translational animal models. However, most models of NEC are limited by their overall complexity and by the fact that they do not incorporate human tissue. To address these limitations, investigators have recently developed precision-based ex vivo models of NEC, also termed 'NEC-in-a-dish' models, which provide the opportunity to increase our understanding of this disease and for drug discovery. These approaches involve exposing intestinal cells from either humans or animals with or without NEC to a combination of environmental and microbial factors associated with NEC pathogenesis. This Review highlights the current progress in the field of NEC model development, introduces NEC-in-a-dish models as a means to understand NEC pathogenesis and examines the fundamental questions that remain unanswered in NEC research. By answering these questions, and through a renewed focus on precision model development, the research community may finally achieve enduring success in improving the outcome of patients with this devastating disease.

Neonatal necrotizing enterocolitis: a case series examining clinical diagnosis with discrepant versus concordant autopsy results

OBJECTIVE

The objective of this study is to determine whether rapidity of death in necrotizing enterocolitis (NEC) increased odds of discordance between clinical and pathological diagnosis.

STUDY DESIGN

Retrospective case-series study including preterm infants admitted to the NICU.

RESULTS

Twenty-two infants met the selection criteria. Gross pathologic evidence of NEC was present in 1/6 cases (17%) where demise occurred <12 h after onset of symptoms, 3/5 cases (60%) within 12-24 h, and 8/11 cases (73%) in >24 h. Histological evidence of necrosis was present in 4/6 (67%) cases when death occurred <12 h, 4/5 (80%) in 12-24 h, and 9/11 (82%) in >24 h. The percentage with gross pathologic evidence showed a monotonic trend (P = 0.031), while the trend was less clear for histologic findings (P = 0.496).

CONCLUSION

Pathologic features of cell death may not have had sufficient time to develop. This study could reassure both healthcare providers and families when pathologic and clinical diagnoses are not consistent.

Faecal calprotectin concentrations in neonates with CHD: pilot study

Neonates with CHD are at increased risk of developing necrotising enterocolitis due to mesenteric hypoperfusion. Necrotising enterocolitis results in repeated feed interruptions contributing to poor growth during the early post-operative phase. Poor weight gain and longer hospital stay are risk factors for death in neonates with CHD. Abdominal radiography is used as a diagnostic tool for necrotising enterocolitis; however, its utility is limited in the early stages of necrotising enterocolitis when pneumatosis intestinalis is absent. Calprotectin is a neutrophil activation biomarker, and elevated levels are evident in inflammatory diseases such as necrotising enterocolitis. The aim of this study was to determine whether there is a correlation between faecal calprotectin concentration and gut inflammation in neonates with CHD. This prospective single-centre study recruited newly diagnosed term patients with duct-dependent CHD between March 2018 and March 2019. Faecal calprotectin concentrations were measured in post-surgical patients using enzyme-linked immunosorbent assay methods. A total of 30 patients were included in the analysis. Calprotectin concentration for patients who developed necrotising enterocolitis was 3528 µg/g compared with 390 µg/g without, compared with 1339 µg/g in patients with suspected necrotising enterocolitis (p = 0.0001). Patients with suspected necrotising enterocolitis had a significantly longer length of hospital stay, on average 18 days longer compared to patients without necrotising enterocolitis (p = 0.03). Faecal calprotectin concentrations may reflect severity of gut inflammation in neonates with CHD. Suspected necrotising enterocolitis contributes to longer days nil by mouth and an increase in length of hospital stay.

Emerging Biomarkers for Prediction and Early Diagnosis of Necrotizing Enterocolitis in the Era of Metabolomics and Proteomics

Necrotizing Enterocolitis (NEC) is a catastrophic disease affecting predominantly premature infants and is characterized by high mortality and serious long-term consequences. Traditionally, diagnosis of NEC is based on clinical and radiological findings, which, however, are non-specific for NEC, thus confusing differential diagnosis of other conditions such as neonatal sepsis and spontaneous intestinal perforation. In addition, by the time clinical and radiological findings become apparent, NEC has already progressed to an advanced stage. During the last three decades, a lot of research has focused on the discovery of biomarkers, which could accurately predict and make an early diagnosis of NEC. Biomarkers used thus far in clinical practice include acute phase proteins, inflammation mediators, and molecules involved in the immune response. However, none has been proven accurate enough to predict and make an early diagnosis of NEC or discriminate clinical from surgical NEC or other non-NEC gastrointestinal diseases. Complexity of mechanisms involved in NEC pathogenesis, which remains largely poorly elucidated, could partly explain the unsatisfactory diagnostic performance of the existing NEC biomarkers. More recently applied technics can provide important insight into the pathophysiological mechanisms underlying NEC but can also aid the detection of potentially predictive, early diagnostic, and prognostic biomarkers. Progress in omics technology has allowed for the simultaneous measurement of a large number of proteins, metabolic products, lipids, and genes, using serum/plasma, urine, feces, tissues, and other biological specimens. This review is an update of current data on emerging NEC biomarkers detected using proteomics and metabolomics, further discussing limitations and future perspectives in prediction and early diagnosis of NEC.