Non-invasive serum amyloid A (SAA) measurement and plasma platelets for accurate prediction of surgical intervention in severe necrotizing enterocolitis (NEC)

Assessment of inflammatory biomarkers to identify surgical/death necrotizing enterocolitis in preterm infants without pneumoperitoneum

BACKGROUND

Necrotizing enterocolitis (NEC) is a life-threatening disease that affects premature infants. However, the role of inflammatory biomarkers in identifying surgical/death NEC without pneumoperitoneum remains elusive.

PURPOSE

We aimed to verify the value of platelet-to-lymphocyte ratio (PLR) and the combination of white blood cell (WBC), absolute neutrophil count (ANC), absolute lymphocyte count (ALC), neutrophil lymphocyte ratio (NLR), PLR, C reactive protein (CRP) and procalcitonin (PCT) in predicting the severity of NEC, and to construct a model to differ surgically NEC from non-surgically NEC.

METHODS

A retrospective analysis was performed on 191 premature infants with NEC. Based on the inclusion and exclusion criteria, 90 infants with Stage II and IIIA NEC were enrolled in this study, including surgical/death NEC (n = 38) and medical NEC (n = 52). The values of inflammatory biomarkers were collected within 24 h of onset.

RESULTS

The univariate analysis revealed that the values of WBC (p = 0.040), ANC (p = 0.048), PLR (p = 0.009), CRP (p = 0.016) and PCT (p < 0.01) in surgical/death NEC cohort were significantly higher than medical NEC cohort. Binary multivariate logistic regression analysis indicates that ANC, PLR, CRP, and PCT are capable of distinguishing infants with surgical/death NEC, and the AUC of the regression equation was 0.79 (95% CI 0.64-0.89; sensitivity 0.63; specificity 0.88), suggesting the equation has a good discrimination.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Elevated PLR is associated with severe inflammation in surgical/death NEC patients. The prediction modelling of combination of ANC, PLR, CRP and PCT can differentiate surgical/death NEC from infants with medical NEC, which may improve risk awareness and facilitate effective communication between nurses and clinicians. However, multicentre research is needed to verify these findings for better clinical management of NEC.

Methods of identifying surgical Necrotizing Enterocolitis-a systematic review and meta-analysis

BACKGROUND

Current data suggests potential benefit of earlier surgery for necrotizing enterocolitis (NEC) however this requires accurate prognostication early in the disease course. This study aims to identify and determine the effectiveness of previously reported methods or tests for the identification of surgical NEC.

METHODS

Systematic review and meta-analysis with registration on PROSPERO including articles describing a method of identifying surgical NEC. Outcomes of interest were effectiveness and repeatability of index test.

RESULTS

Of the 190 full-text articles screened, 90 studies were included which contained 114 methods of identifying surgical NEC in 9546 infants. Of these methods, 44 were a scoring system, 37 a single biomarker, 24 an imaging method, and 9 an invasive method. Sensitivity and specificity ranged from 12.8-100% to 13-100%, respectively. Some methods (9.6%) provided insufficient methods for repeatability within clinical practice or research. Meta-analyses were possible for only 2 methods, the metabolic derangement 7 score and abdominal ultrasound.

CONCLUSIONS

A range of methods for identifying surgical NEC have been identified with varying overall performance and uncertainties about reproducibility and superiority of any method. External validation in large multicentre datasets should allow direct comparison of accuracy and prospective study should evaluate impact on clinical outcomes.

IMPACT

Earlier identification of need for surgery in necrotizing enterocolitis (NEC) has the potential to improve the unfavourable outcomes in this condition. As such, many methods have been developed and reported to allow earlier identification of surgical NEC. This study is the first synthesis of the literature which identifies previously reported methods and the effectiveness of these. Many methods, including scoring systems and biomarkers, appear effective for prognostication in NEC and external validation is now required in multicentre datasets prior to clinical utility.

Enteral Feeding and Antibiotic Treatment Do Not Influence Increased Coefficient of Variation of Total Fecal Bile Acids in Necrotizing Enterocolitis

Introduction

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in preterm infants. In animal models, the accumulation of ileal bile acids (BAs) is a crucial component of NEC pathophysiology. Recently, we showed that the coefficient of variation of total fecal BAs (CV-TBA) was elevated in infants who develop NEC compared to matched controls. However, neither the type of enteral nutrition nor antibiotic treatments-parameters that could potentially influence BA levels-were used to match pairs. Thus, we assessed the relationships between exposure to enteral feeding types and antibiotic treatments with NEC status and CV-TBA.

Materials and methods

Serial fecal samples were collected from 79 infants born with birth weight (BW) ≤1800 gm and estimated gestational age (EGA) ≤32 weeks; eighteen of these infants developed NEC. Total fecal BA levels (TBA) were determined using a commercially available enzyme cycling kit. Relationships between CV-TBA and dichotomous variables (NEC status, demographics, early exposure variables) were assessed by independent samples t-tests. Fisher's exact tests were used to assess relationships between NEC status and categorical variables.

Results

High values for CV-TBA levels perfectly predicted NEC status among infants in this study. However, feeding type and antibiotic usage did not drive this relationship.

Conclusions

As in previous studies, high values for the CV-TBA levels in the first weeks of life perfectly predicted NEC status among infants. Importantly, feeding type and antibiotic usage-previously identified risk factors for NEC-did not drive this relationship.

Emerging prediction methods for early diagnosis of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a life-threatening disease of the digestive system that occurs in the neonatal period. NEC is difficult to diagnose early and the prognosis is poor. Previous studies have reported that abnormalities can be detected before the presentation of clinical symptoms. Based on an analysis of literature related to the early prediction of NEC, we provide a detailed review on the early prediction and diagnosis methods of NEC, including ultrasound, near-infrared spectroscopy, biomarkers, and intestinal microbiota. This review aimed to provide a reference for further research and clinical practice.

Association of neutrophil to lymphocyte ratio with preterm necrotizing enterocolitis: a retrospective case-control study

Background

There have been few studies on the relationship between the neutrophil to lymphocyte ratio (NLR) and necrotizing enterocolitis (NEC). We conducted a retrospective case-control study to investigate this relationship in preterm neonates.

Methods

A total of 199 preterm neonates diagnosed with NEC between January 2018 and January 2020 were included in this study. For each preterm infant with NEC that was admitted to the neonatal intensive care unit (NICU), controls were preterm neonates (matched for gestation and year of birth) who were not diagnosed with NEC. Exclusion criteria were post-maturity, small or large for gestational age (week of pregnancy), congenital major anomalies, and cyanotic congenital heart disease. Univariate and multivariate logistic regression analyses were used to identify the association between NLR and preterm NEC.

Results

This study included 93 preterm neonates with NEC and 106 matched controls. There were no significant differences in gestational age (GA), birth weight (BW), age, sex, vaginal delivery (VD), chorioamnionitis (CA), and gestational diabetes mellitus (GDM) between the groups. Compared with the control group, the lower and higher NLR levels in the NEC group were statistically different. Following univariate analysis, NLR was a risk factor for NEC (odds ratio [OR], 1.40; 95% confidence interval [CI], 1.00–1.90; P = 0.042), and according to multivariate analysis, risk factors for NEC were NLR ≥ 3.20 and NLR < 1.60, within 1 week before NEC diagnosis. Thus, NLR values of ≥ 1.60 and < 3.20 were determined as the predictive cut-off values for protecting preterm infants from NEC (Model I: OR, 0.20; 95% CI, 0.10–0.40; P < 0.001) and (Model II: OR, 0.10; 95% CI, 0.00–0.40; P < 0.001].

Conclusions

NLR ≥ 1.60 and NLR < 3.20 were associated with a decreased risk of NEC in preterm infants.

The Mean Platelet Volume Combined with Procalcitonin as an Early Accessible Marker Helps to Predict the Severity of Necrotizing Enterocolitis in Preterm Infants

Purpose

Methods

Results

Conclusion

Biomarkers of Necrotizing Enterocolitis: The Search Continues

Necrotizing enterocolitis (NEC) is the most common gastrointestinal (GI) emergency in the neonatal intensive care unit. Despite advances in medical care, mortality and morbidity from NEC have not changed. This is likely due to the lack of a clear understanding of this multifactorial disease, and reliable biomarkers for accurate diagnosis of NEC. Currently, the diagnosis of NEC is made by a combination of nonspecific clinical signs, symptoms, and radiological findings. Though biomarkers have been studied extensively, none offer an acceptable sensitivity or specificity to be used. This review will focus on the available literature on biomarkers for preterm NEC, acknowledging the limitations in studies including the variability of inclusion criteria, and most importantly, the lack of gold standard case definition for NEC.

Analysis of Factors Influencing Outcomes in Preterm Infants With Necrotizing Enterocolitis

BACKGROUND

To explore the surgical outcomes between patients with perforated and non-perforated neonatal necrotizing enterocolitis (NEC) and identify indications for surgical intervention.

METHODS

The surgical outcomes of 271 children with NEC admitted to the Seventh Medical Center of Chinese PLA General Hospital between August 2009 and August 2020 were retrospectively analyzed. The patients were divided into the non-perforated and perforated groups. The preoperative factors, including gestational age, birth weight, intrauterine infection, cholestasis, platelet change, white blood cell count, and C-reactive protein level were compared between the two groups, along with postoperative factors including infection status, complications, enteral and parenteral nutrition time, ICU time, ventilator use time, and intestinal necrosis length. Bell staging was performed for the two groups and the mortality of different Bell stages was explored. The risk of death and predisposing factors of patients with NEC were analyzed.

RESULTS

In total, 271 children undergoing surgery were included in this study. A total of 188 children were observed without perforation, including 57 deaths (30.3%), and 83 children with perforation, including 24 deaths (28.9%). Preoperative cholestasis and time from NEC diagnosis to surgery were significantly different between the two groups (P < 0.05). Postoperative factors, including parenteral nutrition time (32 [3-94] days vs. 23 [1-53] days), enteral nutrition time (27 [0-86] days vs. 18 [0-81] days), NICU time (44 [5-125] days vs. 29 [1-92] days), and length of intestinal necrosis (15 [0-92] cm vs. 10 [2-70] cm), were significant. The mortality rate of patients with Bell stage IIIA was higher than that of patients with Bell stage IIIB. A total of 81 patients had 30-day postoperative mortality (57 non-perforated cases). Multivariate Cox regression analysis showed that non-perforation was a poor prognostic factor for survival outcome (hazard ratio 2.288, 95% confidence interval [1.329-3.940], P = 0.003).

CONCLUSIONS

Preterm infants in the non-perforated group had more serious complications and had a longer recovery time after surgery. Bell staging is not accurate in diagnosing severe NEC that needs surgical intervention.

Biomarkers of gut injury in neonates - where are we in predicting necrotising enterocolitis?

Despite advances in neonatal care Necrotising Enterocolitis (NEC) continues to have a significant mortality and morbidity rate, and with increasing survival of those more immature infants the population at risk of NEC is increasing. Ischaemia, reperfusion, and inflammation underpin diseases affecting intestinal blood flow causing gut injury including Necrotising Enterocolitis. There is increasing interest in tissue biomarkers of gut injury in neonates, particularly those representing changes in intestinal wall barrier and permeability, to determine whether these could be useful biomarkers of gut injury. This article reviews current and newly proposed markers of gut injury, the available literature evidence, recent advances and considers how effective they are in clinical practice. We discuss each biomarker in terms of its effectiveness in predicting NEC onset and diagnosis or predicting NEC severity and then those that will aid in surveillance and identifying those infants are greatest risk of developing NEC.

Characteristics of Surgical Necrotizing Enterocolitis: Is It Different from Medical Necrotizing Enterocolitis? A Single-Center Retrospective Study

(1) Background: Necrotizing enterocolitis (NEC) is one of the leading causes of death in newborns despite improvements in the care of critically ill neonates. Approximately 50–70% of the cases are managed by medical therapy. However, the remaining patients require surgical intervention. The purpose of our study was to analyze the factors associated with patients requiring surgical treatment compared to patients requiring only medical treatment; (2) Method: Patients diagnosed with necrotizing enterocolitis over a period of 14 years (January 2003–December 2016) in a single tertiary referral children’s hospital were retrospectively enrolled. Demographics and clinical data were collected through the medical record and were analyzed using Pearson’s χ2 test, t-tests, and linear regression; (3) Results: A total of 189 NEC patients were analyzed. In the surgical NEC group, gestational age was lower (p = 0.018), body weight at birth was lower (p = 0.034), comorbidity with respiratory distress syndrome (RDS) was higher (p = 0.005), the days of antibiotic use were greater (p = 0.014), the percentage of breast milk feeding was lower (p = 0.001), and the length of hospital stay was longer (p < 0.000). The in-hospital mortality between the two groups was not significantly different (p = 0.196). In multivariate logistic analysis, breast milk feeding remained less associated with surgical NEC (OR = 0.366, 95% CI: 0.164–0.817), whereas the length of hospital stay was more associated with surgical NEC (OR = 1.010, 95% CI: 1.001–1.019); (4) Conclusion: Comparing medical and surgical NEC, a significantly lower percentage of surgical NEC patients were fed breast milk and their hospital stays were longer.

New Strategies for Necrotizing Enterocolitis Diagnosis and Prevention in Newborns

Necrotizing enterocolitis is one of the most frequent and severe gastrointestinal diseases that affect preterm newborns in Neonatal Intensive Care Units. It was firstly described in 1960s, but this clinical entity was not widely recognized until the advent of modern neonatal intensive care. The disease is characterized by submucosal edema, infiltration of intestinal wall by immune cells, specifically neutrophils and, in severe forms, wall necrosis that leads to intestinal perforation. Its incidence is inversely associated to birth weight and gestational age. Necrotizing enterocolitis has been responsible for high rates of morbidity and mortality (15-30%), despite improvements made in neonatal care in the last decades. The challenge is to optimize strategies for early diagnosis, define the best medical and surgical treatments and standardize preventive measures. Several biomarkers have been proposed for the early prediction of necrotizing enterocolitis onset in preterm newborns and can be useful not only for diagnostic purposes but also for prediction of disease progression and severity. The purpose of this paper is to illustrate the most recent evidence regarding the diagnosis and prevention of necrotizing enterocolitis. This manuscript contributes to clinical decision-making in preterm neonates at high risk of developing necrotizing enterocolitis.

Low serum albumin concentration predicts the need for surgical intervention in neonates with necrotizing enterocolitis

PURPOSE

To investigate whether serum albumin (SA) concentration can predict the need for surgical intervention in neonates with necrotizing enterocolitis (NEC).

METHODS

Retrospective review of all cases with NEC Bell's stage 2 and 3 that were treated in a single center between 2009 and 2015. Data on patient demographics, clinical parameters, laboratory findings and surgical status were recorded. Receiver operating characteristics analysis was used to evaluate optimal cutoffs and predictive values.

RESULTS

Overall, 151 neonates with NEC were identified. Of these, 132 (87.4%) had confirmed NEC Bell's stage 2. The median gestational age was 28.4 (range, 23.1-39.0) weeks and 69 (52.3%) had a birth weight of ≤1000 g. Sixty-eight (51.5%) underwent surgery, showing a sustained reduction in SA over time with significantly lower median SA levels compared to 64 (48.5%) cases that responded well to medical treatment (18.3 ± 3.7 g/L vs. 26.0 ± 2.0 g/L; P < 0.001). SA concentration of ≤20 g/L on day 2 of NEC diagnosis was a significant predictor for surgery (OR 3.41; P = 0.019) with a positive predictive value of 71.4%.

CONCLUSIONS

An SA concentration of ≤20 g/L on day 2 of the NEC disease process is associated with a higher likelihood for surgical intervention in neonates with NEC Bell's stage 2. SA, in combination with other clinical parameters and serological markers, may be a useful predictive tool for surgery in NEC.

LEVEL OF EVIDENCE

II.

Urinary I-FABP, L-FABP, TFF-3, and SAA Can Diagnose and Predict the Disease Course in Necrotizing Enterocolitis at the Early Stage of Disease

Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease affecting mainly preterm newborns. It is characterized by unexpected onset and rapid progression with specific diagnostic signs as pneumatosis intestinalis or gas in the portal vein appearing later in the course of the disease. Therefore, we analyzed diagnostic and prognostic potential of the markers of early NEC pathogenesis, such as excessive inflammatory response (serum amyloid A (SAA)) and gut epithelium damage (intestinal and liver fatty acid-binding protein (I-FABP and L-FABP, respectively) and trefoil factor-3 (TFF-3)). We used ELISA to analyze these biomarkers in the urine of patients with suspected NEC, either spontaneous or surgery-related, or in infants without gut surgery (controls). Next, we compared their levels with the type of the disease (NEC or sepsis) and its severity. Already at the time of NEC suspicion, infants who developed NEC had significantly higher levels of all tested biomarkers than controls and higher levels of I-FABP and L-FABP than those who will later develop sepsis. Infants who will develop surgery-related NEC had higher levels of I-FABP and L-FABP than those who will develop sepsis already during the first 6 hours after the abdominal surgery. I-FABP was able to discriminate between infants who will develop NEC or sepsis and the SAA was able to discriminate between medical and surgical NEC. Moreover, the combination of TFF-3 with I-FABP and SAA could predict pneumatosis intestinalis, and the combination of I-FABP, L-FABP, and SAA could predict gas in the portal vein or long-term hospitalization and low SAA predicts early full enteral feeding. Thus, these biomarkers may be useful not only in the early, noninvasive diagnostics but also in the subsequent NEC management.

Prostaglandin E-major urinary metabolite as a noninvasive surrogate marker for infantile necrotizing enterocolitis

BACKGROUND

Early definitive diagnosis of necrotizing enterocolitis (NEC) based on Bell's staging criteria is difficult because there are few observable changes on abdominal imaging and blood chemistry tests at the onset of the disease.

PURPOSE

To investigate whether prostaglandin E-2 major urinary metabolite (PGE-MUM) can be a useful surrogate marker reflecting the disease state and severity of NEC in infants.

METHODS

Infants were enrolled in this study between January 2014 and December 2016. NEC diagnosis was based on Bell's staging criteria > Stage II or necrotic bowel observed at surgery. After diagnosis, PGE-MUM level was measured and compared with that of the other disease and healthy infant groups.

RESULTS

Median PGE-MUM value was highest in the NEC group (576 [65-3672] μg/g•Cre/BSA × 1000), followed by the other disease group (94 [57-296] μg/g•Cre/BSA × 1000) and the healthy infant group (19 [10-44] μg/g•Cre/BSA × 1000) (sensitivity: 92.3%, specificity: 81.5%, accuracy: 85.0%; p < 0.01). PGE-MUM level correlated with improved status of NEC, length of necrotic intestine, and Bell's staging criteria.

CONCLUSIONS

PGE-MUM level may be a useful surrogate biomarker reflecting the disease state of NEC. The method of urine sample collection is also advantageous, being noninvasive for infants. This is the first study reporting PGE-MUM level in NEC.

TYPE OF STUDY

Study of diagnostic test.

LEVEL OF EVIDENCE

LEVEL II.

Early diagnosis of necrotizing enterocolitis by plasma RELMβ and thrombocytopenia in preterm infants: A pilot study

BACKGROUND

As the inflammatory regulators, Resistin-like molecule β (RELMβ) and Resistin might be potential biomarkers of necrotizing enterocolitis (NEC), while thrombocytopenia is often related to the severity of NEC, clinical observation suggests that thrombocytopenia might be an early biomarker of NEC. The aim of this study was to evaluate whether RELMβ, Resistin and thrombocytopenia could be biomarkers for early diagnosis of NEC in preterm infants.

METHODS

From January 2016 to March 2018, twenty-nine NEC preterm infants who were diagnosed with NEC (Bell's stage ≥Ⅱ) by two independent neonatologists and twenty-nine non NEC preterm infants at neonatal intensive care unit in our hospital were enrolled in this case-control study. Preterm infants with a history of serious infections (sepsis, pneumonia), asphyxia, and congenital malformations were excluded from the study. The plasma RELMβ and Resistin were evaluated by enzyme linked immunosorbent assay (ELISA) and serum platelet levels were measured directly by ordinary light microscope at the diagnosis of NEC (Bell's stage ≥Ⅱ).

RESULTS

Plasma RELMβ levels in NEC group were significantly higher than control group (P < 0.05). The optimal cut-off value of RELMβ determined by receiver operating characteristic curve (ROC) was 378.3 ng/L. The overall estimates for sensitivity and specificity of high RELMβ concentrations in the detection of neonatal NEC were 71.4% and 91.7%, respectively. No significant difference was found in plasma Resistin levels between two groups (P > 0.05). If platelet level was less than 157 × 10⁹/L, the sensitivity and specificity were 69.34% and 82.87%, respectively. Interestingly, the combination of RELMβ and thrombocytopenia increased sensitivity and specificity to 82.89% and 93.21%, respectively.

CONCLUSION

The combination of RELMβ and thrombocytopenia was a reliable biomarker for the early diagnosis of NEC in this study with 82.89% sensitivity and 93.21% specificity, respectively.

Recent Potential Noninvasive Biomarkers in Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a rare but devastating gastrointestinal disease that predominately affects preterm neonates. Numerous studies have revealed that NEC is strongly associated with very low birth weight, degree of prematurity, formula feeding, infection, hypoxic/ischemic injury, and enteric dysbiosis. Given these clinical associations, the search for a deeper understanding of disease pathogenesis has led to an intense interest in the discovery and development of noninvasive biomarkers of NEC from stool, urine, and serum. Biomarkers for NEC may serve at least two general purposes of urgent unmet need: to improve diagnostic accuracy and disease prediction and to reveal the mechanism of the disease. This review will provide an overview of recent research focused on clinical NEC and highlight the advances that were made within the past five years towards the development of noninvasive diagnostic biomarkers.

Biomarker Discovery and Utility in Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a devastating disease of prematurity, with no current method for early diagnosis. Diagnosis is particularly challenging, frequently occurring after the disease has progressed to the point of significant and often irreversible intestinal damage. Biomarker research has tremendous potential to advance clinical management of NEC and our understanding of its pathogenesis. This review discusses the need for novel biomarkers in NEC management, evaluates studies investigating such biomarkers, and explains the difficulties associated with translating biomarker discovery into clinical use.

An update on biomarkers of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) remains a devastating surgical emergency with high morbidity and mortality in preterm infants. Slow but steady progress has been made in past years searching for novel biomarkers of NEC, for both surveillance and diagnostic purposes. This review primarily focuses on recent discoveries: clinical applications of different categories of biomarkers for surveillance, early diagnosis, and predicting severity and prognosis; and understanding of pathophysiological mechanisms as a basis to rationalize the search for 'gut-associated specific biomarkers' of NEC. An important next step is to collaborate with our industrial partners to develop point-of-care tests, and to discover novel and gut-associated specific biomarkers that can be used for surveillance and early diagnosis of NEC in routine clinical settings.

Combination of plasma white blood cell count, platelet count and C-reactive protein level for identifying surgical necrotizing enterocolitis in preterm infants without pneumoperitoneum

PURPOSE

To evaluate whether plasma white blood cell count (WBC), platelet count (PLT), and C-reactive protein level (CRP) can be used to differentiate surgical necrotizing enterocolitis (NEC) from medical NEC.

METHODS

Preterm infants admitted between January 1, 2011 and July 31, 2015 were stratified by the need of surgery as surgical NEC (n = 41) and medical NEC (n = 43). The values of WBC, PLT and CRP were collected at time before NEC occurred (T₀), at onset of NEC (T₁) and when surgical assessment was required (T₂). Patients admitted between August 1, 2015 and March 1, 2018 (n = 53) were collected for further verification.

RESULTS

Variables identified in logistic regression analysis predicting surgical NEC were WBC and PLT at T₂ (WBC₂ and PLT₂). The predictive probability of surgery (P) could be calculated by the equation [Formula: see text]. The area under curve of P was 0.84 and the ideal cutoff value was 0.55, with sensitivity and specificity of 85 and 81%, respectively. This cutoff value got an sensitivity of 80% and specificity of 79% in the verification group.

CONCLUSION

Combination of WBC and PLT can effectively differentiate surgical NEC from medical NEC infants when surgical assessment was required.

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

Better means to diagnose and define necrotizing enterocolitis are needed to guide clinical practice and research. Adequacy of Bell's staging system for clinical practice and clarity of cases used in NEC clinical datasets has been a topic of controversy for some time. This article provides reasons why a better global definition for NEC is needed and offers a simple alternative bedside definition for preterm NEC called the "Two out of Three" rule. Some argue that biomarkers may fill knowledge gaps and provide greater precision in defining relevant features of a clinical disease like NEC. NEC biomarkers include markers of inflammation, intestinal dysfunction, hematologic changes, and clinical features. Development and reporting of NEC biomarkers should be guided by the FDA's BEST Consensus resource, "Biomarkers, EndpointS, & other Tools" and consistently report metrics so that studies can be compared and results pooled. Current practice in the NICU would be enhanced by clinical tools that effectively inform the clinical team that a baby is at increasing risk of NEC. Ideally, these tools will incorporate both clinical information about the baby as well as molecular signals that are indicative of NEC. While meaningful biomarkers for NEC and clinical tools exist, translation into practice is mediocre.

Congenital Heart Disease Increases Mortality in Neonates With Necrotizing Enterocolitis

Background: Studies on the influence of congenital heart disease (CHD) on neonates with necrotizing enterocolitis (NEC) have produced varied results. We therefore examined the influence of CHD on NEC outcomes. Methods: We carried out a retrospective single-center study including infants with confirmed NEC, treated between 2004 and 2017. We excluded patients with isolated patent ductus arteriosus or pulmonary hypertension (n = 45) and compared outcomes of patients with hemodynamically relevant CHD (n = 38) and those without CHD (n = 91). Results: Patients with CHD were more mature than those without CHD [gestational age, median, 95% confidence interval (CI95), 37.1, 34.5-37.2w, vs. 32.6, 31.9-33.3w; P < 0.01]. The presence of CHD did not influence the frequencies of severe disease (overall 21% Bell stage III), nor surgical interventions (overall 30%), the occurrence of intestinal complications (overall 13%), nor the duration of hospitalization (overall 38 days in survivors). The overall mortality as well as NEC-related mortality was increased with the presence of CHD, being 50% (19 out of 38) and 13% (5 out of 38), respectively, when compared to patients without CHD, being 8% (7 out of 91) and 3% (3 out of 91). The presence of CHD and of advanced NEC stage III were independent predictors of NEC-associated fatalities with multivariable odds ratios (CI95) of 7.0, 1.3-39.5 for CHD, and of 3.4, 1.6-7.5 for stage III disease. Conclusions: While some outcome parameters in neonates with NEC remained unaffected by the presence of CHD, the mortality risk for patients with CHD was seven times higher than without CHD.

Determinant Variables, Enteric Pathogen Burden, Gut Function and Immune-related Inflammatory Biomarkers Associated With Childhood Malnutrition: A Prospective Case-Control Study in Northeastern Brazil

Malnutrition results in serious consequences for growth and cognitive development in children. We studied select child and maternal biologic factors, socioeconomic factors, enteric pathogenic burden and gut function biomarkers in 402 children 6-24 months of age in Northeastern Brazil. In this prospective case-control study, not being fed colostrum [odds ratio (OR): 3.29, 95% confidence interval (CI): 1.73-6.26], maternal age ≥18 years (OR: 1.88, 95% CI: 1.10-3.22) and no electric fan (OR: 2.46, 95% CI: 1.22-4.96) or bicycle (OR: 1.80, 95% CI: 1.10-2.95) in the household were positively associated, and higher birth weight (OR: 0.27, 95% CI: 0.19-0.38), larger head circumference (OR: 0.74, 95% CI: 0.66-0.82) and shortness of breath in the last 2 weeks (OR: 0.49, 95% CI: 0.27-0.90) were negatively associated with malnutrition. Subclinical enteric pathogen infections were common, and enteroaggregative Escherichia coli infections were more prevalent in malnourished children (P = 0.045). Biomarkers such as the lactulose-mannitol test, myeloperoxidase, neopterin and calprotectin were highly elevated in both malnourished and nourished children. Nourished children had a better systemic immune response than the malnourished children, as detected by elevated serum amyloid A-1 and soluble cluster of differentiation protein 14 biomarkers (P < 0.001). Serum amyloid A-1 and soluble cluster of differentiation protein 14 were also associated with better nutritional Z scores. Neonatal, maternal and socioeconomic factors were associated with malnutrition in children. There was a substantial subclinical enteric pathogen burden, particularly with enteroaggregative E. coli, in malnourished children.

Biomarkers of necrotizing enterocolitis: a review of literature

Necrotizing enterocolitis (NEC) is among the most serious gastrointestinal emergency in very low birth weight (VLBW), extremely low birth weight (ELBW) and extremely low gestational age neonates (ELGAN), affecting 7-14% of these neonates. Despite extensive research, the underlying aetiology of NEC still remains blurred. Due to high mortality, morbidity and its delayed presentation, early detection of NEC is considered to be lifesaving. A number of biomarkers have been studied for early detection and prediction of severity of NEC but till date, no ideal marker has been discovered. Molecular techniques like proteomic and metabolomic have recently emerged in the field for the development of biomarkers for early detection and understanding the pathophysiology of NEC. We did literature search for identifying all biomarkers that have been used for the detection of NEC and, in this review article, we discuss these biomarkers along with the available current evidence.

Surgical necrotizing enterocolitis

Although currently available data are variable, it appears that the incidence of surgical necrotizing enterocolitis (NEC) has not decreased significantly over the past decade. Pneumoperitoneum and clinical deterioration despite maximal medical therapy remain the most common indications for operative treatment. Robust studies linking outcomes with specific indications for operation are lacking. Promising biomarkers for severe NEC include fecal calprotectin and S100A12; serum fatty acid-binding protein; and urine biomarkers. Recent advances in ultrasonography make this imaging modality more useful in identifying surgical NEC and near-infrared spectroscopy (NIRS) is being actively studied. Another fairly recent finding is that regionalization of care for infants with NEC likely improves outcomes. The neurodevelopmental outcomes after surgical treatment are known to be poor. A randomized trial near completion will provide robust data regarding neurodevelopmental outcomes after laparotomy versus drainage as the initial operative treatment for severe NEC.

Necrotizing enterocolitis symposium: Epidemiology and early diagnosis

Despite decades of research on necrotizing enterocolitis (NEC), the outlook for infants afflicted by this devastating disease is all too often bleak. The aim of this symposium at the BAPS conference in Amsterdam was to highlight recent advances in the knowledge of the epidemiology and diagnosis of NEC. There were important contributions on the disease in the United Kingdom, both from a neonatal and from a surgical point of view, whereas colleagues from the Netherlands and elsewhere in Europe shared their insights into novel diagnostic tools, both biofluid and imaging based.

LEVEL OF EVIDENCE

Level V.

Elevated fecal calprotectin levels during necrotizing enterocolitis are associated with activated neutrophils extruding neutrophil extracellular traps

OBJECTIVE

Neonates with necrotizing enterocolitis (NEC) have higher calprotectin levels in stool than do healthy neonates. However, it is not known whether high stool calprotectin at the onset of bowel symptoms identifies neonates who truly have NEC vs other bowel disorders.

STUDY DESIGN

Neonates were eligible for this study when an x-ray was ordered to 'rule-out NEC'. Stool calprotectin was quantified at that time and in a follow-up stool. Each episode was later categorized as NEC or not NEC. The location of calprotectin in the bowel was determined by immunohistochemistry.

RESULTS

Neonates with NEC had higher initial and follow-up stool calprotectin levels than did neonates without NEC. Calprotectin in bowel from neonates with NEC was within neutrophil extracellular traps (NETs).

CONCLUSION

At the onset of signs concerning for NEC, fecal calprotectin is likely to be higher in neonates with NEC. Calprotectin in their stools is exported from neutrophils via NETs.

Serologic Intestinal-Fatty Acid Binding Protein in Necrotizing Enterocolitis Diagnosis: A Meta-Analysis

Background. Previous studies showed that intestinal-fatty acid binding protein (I-FABP) may be a valid and promising serologic biomarker for early diagnosis of necrotizing enterocolitis (NEC). Objective. To investigate the early diagnostic value of serologic I-FABP in NEC for the premature neonates. Methods. All major databases were searched from January 1, 1990, to May 1, 2015. We used Meta-Disc 1.4 and Revman5.0 software to calculate the diagnostic accuracy. Results. Seven studies with 444 subjects were identified. The pooled sensitivity of I-FABP was 0.67 for NEC I, 0.74 for NEC II, and 0.83 for NEC III, and the pooled specificity was 0.84, respectively, which showed a moderate diagnostic accuracy. The area under curve (AUC) for each stage was 0.75 (Q^⁎ = 0.69), 0.82 (Q^⁎ = 0.76), and 0.91 (Q^⁎ = 0.84). The diagnostic threshold analysis showed no significant difference in threshold effect. The metaregression showed that the cut-off value has the largest effect on heterogeneity. The funnel plots indicated the existence of publication bias. Conclusion. I-FABP is a valid serologic biomarker for early diagnosis in NEC for the premature neonates with a moderate accuracy.

Intestinal fatty acid-binding protein levels in Necrotizing Enterocolitis correlate with extent of necrotic bowel: results from a multicenter study

BACKGROUND

Intestinal fatty acid-binding protein (I-FABP) is considered as a specific marker for enterocyte damage in necrotizing enterocolitis (NEC).

OBJECTIVE

The purpose of this study was to evaluate the association of plasma and urinary I-FABP levels with the extent of macroscopic intestinal necrosis in surgical NEC.

METHODS

We combined data from prospective trials from two large academic pediatric surgical centers. Nine and 10 infants with surgical NEC were included, respectively. Plasma and urinary of I-FABP at disease onset were correlated with the length of intestinal resection during laparotomy.

RESULTS

Median length of bowel resection was 10cm (range 2.5-50) and 17cm (range 0-51), respectively. Median I-FABP levels were 53ng/mL (range 6.3-370) and 4.2ng/mL (range 1.1-15.4) in plasma in cohort 1 respectively cohort 2 and 611ng/mL (range 3-23,336) in urine. The length of bowel resection significantly correlated with I-FABP levels in plasma (Rho 0.68; p=0.04 and Rho 0.66;p=0.04) and in urine (Rho 0.92; p=0.001).

CONCLUSION

This 'proof of concept' study demonstrates that plasma and urine I-FABP levels at disease onset was strongly associated with the length of intestinal resection in surgical NEC. This offers further evidence that I-FABP levels are a promising biomarker for assessing intestinal necrosis in infants with advanced NEC.

Necrotizing enterocolitis: a clinical review on diagnostic biomarkers and the role of the intestinal microbiota

Necrotizing enterocolitis (NEC) remains one of the most frequent gastrointestinal diseases in the neonatal intensive care unit, with a continuing unacceptable high mortality and morbidity rates. Up to 20% to 40% of infants with NEC will need surgical intervention at some point. Although the exact pathophysiology is not yet elucidated, prematurity, use of formula feeding, and an altered intestinal microbiota are supposed to induce an inflammatory response of the immature intestine. The clinical picture of NEC has been well described. However, an early diagnosis and differentiation against sepsis is challenging. Besides, it is difficult to timely identify NEC cases that will deteriorate and need surgical intervention. This may interfere with the most optimal treatment of infants with NEC. In this review, we discuss the pathogenesis, diagnosis, and treatment of NEC with a focus on the role of microbiota in the development of NEC. An overview of different clinical prediction models and biomarkers is given. Some of these are promising tools for accurate diagnosis of NEC and selection of appropriate therapy.

Noninvasive biomarkers of necrotizing enterocolitis

Necrotizing enterocolitis is an acute inflammatory disease, which primarily affects preterm infants, and is a leading cause of morbidity and mortality in the neonatal intensive care unit. Unfortunately, necrotizing enterocolitis can be difficult to distinguish from other diseases and clinical conditions especially during the early course of the disease. This diagnostic uncertainty is particularly relevant to clinical evaluation and medical management and potentially leads to unnecessary and extended periods of cessation of enteral feedings and prolonged courses of parenteral nutrition and antibiotics. Biomarkers are molecular indicators of a disease process, diagnosis, prognosis and can be used to monitor the effects of disease management. Historically, there has been a paucity of reliable and robust biomarkers for necrotizing enterocolitis. However, several studies have recently identified promising biomarkers. Noninvasive samples for biomarker measurement are preferred and may have certain advantages in the preterm infant. In this review article, we focus on recent exciting and promising discoveries in noninvasive biomarkers for necrotizing enterocolitis.