Serum levels of interleukin-8 and gut-associated biomarkers in diagnosing necrotizing enterocolitis in preterm infants

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.

Reduced Expression of REG4 as a Sign of Altered Goblet Cell Function in Necrotizing Enterocolitis

OBJECTIVE

 Defective Goblet cells have been proposed to be involved in necrotizing enterocolitis (NEC). The aim was to study the expression of the Goblet cell marker REG4 and its potential involvement in NEC in preterm infants with and without NEC.

STUDY DESIGN

 Seventy histologically intact intestinal biopsies were studied: 43 were collected during surgery due to NEC (NEC group: 26.5 ± 3.0 weeks' gestational age [wGA]), and 27 from individuals who underwent surgery due to other conditions (Control group; 36.1 ± 4.5 wGA). The tissue samples were immunohistochemically stained for REG4. REG4 expression was quantified with a semiautomated digital image analysis and with clinical data compared between the groups.

RESULTS

 REG4 expression was lower in the NEC group than in the Control group (p = 0.035). Low REG4 expression correlated to the risk of NEC (p = 0.023). In a multivariable logistic regression analysis including GA and REG4 expression for NEC risk, only GA (p < 0.001) and not REG4 expression (p = 0.206) was associated with NEC risk.

CONCLUSION

 This study concludes that Goblet cell dysfunction may be involved in NEC development, as low expression of the Goblet cell marker REG4 was related to an increased NEC risk in preterm infants. Maturity could however not be excluded as a potential confounder for REG4 expression.

KEY POINTS

· REG4 is a specific Goblet cell marker not yet studied in NEC.. · REG4 was quantified in intestinal biopsies from infants with and without NEC.. · REG4 expression was lower in infants with NEC, and expression seems to be maturity dependent..

Extracellular Nicotinamide Phosphoribosyltransferase Is a Therapeutic Target in Experimental Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency of prematurity. Postulated mechanisms leading to inflammatory necrosis of the ileum and colon include activation of the pathogen recognition receptor Toll-like receptor 4 (TLR4) and decreased levels of transforming growth factor beta (TGFβ). Extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a novel damage-associated molecular pattern (DAMP), is a TLR4 ligand and plays a role in a number of inflammatory disease processes. To test the hypothesis that eNAMPT is involved in NEC, an eNAMPT-neutralizing monoclonal antibody, ALT-100, was used in a well-established animal model of NEC. Preterm Sprague-Dawley pups delivered prematurely from timed-pregnant dams were exposed to hypoxia/hypothermia and randomized to control-foster mother dam-fed rats, injected IP with saline (vehicle) 48 h after delivery; control + mAB-foster dam-fed rats, injected IP with 10 µg of ALT-100 at 48 h post-delivery; NEC-orally gavaged, formula-fed rats injected with saline; and NEC + mAb-formula-fed rats, injected IP with 10 µg of ALT-100 at 48 h. The distal ileum was processed 96 h after C-section delivery for histological, biochemical, molecular, and RNA sequencing studies. Saline-treated NEC pups exhibited markedly increased fecal blood and histologic ileal damage compared to controls (q < 0.0001), and findings significantly reduced in ALT-100 mAb-treated NEC pups (q < 0.01). Real-time PCR in ileal tissues revealed increased NAMPT in NEC pups compared to pups that received the ALT-100 mAb (p < 0.01). Elevated serum levels of tumor necrosis factor alpha (TNFα), interleukin 6 (IL-6), interleukin-8 (IL-8), and NAMPT were observed in NEC pups compared to NEC + mAb pups (p < 0.01). Finally, RNA-Seq confirmed dysregulated TGFβ and TLR4 signaling pathways in NEC pups that were attenuated by ALT-100 mAb treatment. These data strongly support the involvement of eNAMPT in NEC pathobiology and eNAMPT neutralization as a strategy to address the unmet need for NEC therapeutics.

The supplementation of female dogs with live yeast Saccharomyces cerevisiae var. boulardii CNCM I-1079 acts as gut stabilizer at whelping and modulates immunometabolic phenotype of the puppies

Time around parturition is a stressful period for both bitches and their puppies. The use of probiotics has been proposed, e.g., in pigs, to improve health status of sows, their reproductive performances and in turn, the health and performance of their progeny. The objective of the present study was to evaluate the impact, on both dams and puppies, of a supplementation of bitches with the live yeast Saccharomyces cerevisiae var. boulardii CNCM I-1079 (SB-1079) during the second part of the gestation and the lactation period. A total of 36 bitches of medium and large-sized breeds were enrolled. They were divided into two groups, one of which received 1.3 × 109 colony forming units of live yeast per day. At dam's level, SB-1079 yeast shaped a different microbiota structure between the two groups just after whelping, impacted alpha diversity and some plasma metabolites related to energy metabolism. Regarding reproductive performances, SB-1079 improved gross energy of the colostrum (1.4 vs. 1.2 kcal of ME/g) as well as the concentration of protein in milk at Day 7 after parturition (10.4 vs. 7.6%). SB-1079 also reduced the odds of having low birth weight in the litter. At puppy's level, a modulation of immunometabolic phenotype is suggested by the observation of increased growth rates during the early pediatric period (i.e., between 21 and 56 days of life, 225 vs. 190%) and a decrease of the IL-8:IL-10 ratio after vaccination against rabies (4.2 vs. 16.9). Our findings suggest that SB-1079 supplementation during gestation and lactation has the potential to enhance health of bitches and in turn health of puppies through maternal programming.

Fatty-Acid-Binding Proteins: From Lipid Transporters to Disease Biomarkers

Fatty-acid-binding proteins (FABPs) serve a crucial role in the metabolism and transport of fatty acids and other hydrophobic ligands as an intracellular protein family. They are also recognized as a critical mediator in the inflammatory and ischemic pathways. FABPs are found in a wide range of tissues and organs, allowing them to contribute to various disease/injury developments that have not been widely discussed. We have collected and analyzed research journals that have investigated the role of FABPs in various diseases. Through this review, we discuss the findings on the potential of FABPs as biomarkers for various diseases in different tissues and organs, looking at their expression levels and their roles in related diseases according to available literature data. FABPs have been reported to show significantly increased expression levels in various tissues and organs associated with metabolic and inflammatory diseases. Therefore, FABPs are a promising novel biomarker that needs further development to optimize disease diagnosis and prognosis methods along with previously discovered markers.

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.

Does protocol miconazole administration improve mortality and morbidity on surgical necrotizing enterocolitis?

PURPOSE

Our previous clinical pilot study reported that miconazole (MCZ) prevented morbidity from surgical necrotizing enterocolitis (NEC). The present study re-investigated this effect in a long-term cohort over 20 years.

METHODS

We conducted a retrospective cohort study from April 1998 to March 2020. A total of 1169 extremely low-birth-weight infants (ELBWIs) admitted to our neonatal intensive care unit, including 45 with NEC (3.8%), underwent surgery. Since 2002, protocol MCZ administration for 3 weeks has been applied for neonates born before 26 weeks' gestation or weighing under 1000 g. We compared the background characteristics and clinical outcomes between patients with and without MCZ administration.

RESULTS

The morbidity rate decreased after applying the MCZ protocol, but no improvement in mortality was seen. A propensity score-matched analysis indicated that treated patients by MCZ showed a delay in developing surgical NEC by 12 days. The MCZ protocol also helped increase body weight at surgery. Prophylactic MCZ administration did not improve the neurological development of the language-social and postural-motor domains in the surgical NEC patients. But cognitive-adaptive domain caught up by a chronological age of 3 years old.

CONCLUSIONS

Revising the protocol to extend the dosing period may improve the outcomes of surgical NEC after the onset.

Maternal Oxidized Soybean Oil Administration in Rats during Pregnancy and Lactation Alters the Intestinal DNA Methylation in Offspring

As a food contaminant, oxidized oil or lipid oxidative products have been proven to exert toxicological effects on the growth and development of animals and humans. Research shows that maternal oxidative stress damage might transmit to another generation by epigenetic modulation. However, current evidence is still not clear on the mechanism of the effects of dietary oxidized oil during pregnancy on the two generations. This study employed a rat model fed with oxidized soybean oil (OSO) during pregnancy and lactation to explore the effects of the oxidative degree (0, 200, 400, and 800 mequiv of O₂/kg) on the placental RNA methylation and DNA methylation in offspring jejunum. The results showed that following the ingestion of OSO, the placental genes of different m⁶A methylation were significantly enriched to nutrient metabolic processes and hormone activity. In addition, the intestine in offspring hypofunctioned observably, such as reducing the height of villi and the level of anti-inflammatory cytokine. Furthermore, maternal intake of OSO during pregnancy can damage the intestinal barrier function of offspring by inhibiting the proliferation and differentiation of intestinal epithelial cells and reducing the activity of intestinal DNA methyltransferase. In conclusion, this study reinforces the assertion that maternal OSO consumption during gestation and lactation negatively affects the placental health and intestinal development of suckling pups.

Potential Role of Serum Intestinal Fatty Acid-Binding Protein as a Marker for Early Prediction and Diagnosis of Necrotizing Enterocolitis in Preterm Neonates

Introduction:

Intestinal fatty acid-binding protein (I-FABP) is located in the apex of mature enterocytes and released into circulation; once the injury of enterocyte happens, its circulating levels are considered an early and sensitive marker of intestinal ischemia as in necrotizing enterocolitis (NEC); because of its small molecular weight, it can be detected in urine.

Aims:

The aim was to study the usefulness of both serum and urine I-FABP in early diagnosis of NEC and to correlate the serum and urinary levels.

Settings and Design:

This study was case–control design.

Methods:

Simultaneous serum and urine samples obtained at the onset of symptoms, in 40 preterms with suspected NEC, with gestational age ± 27.70 weeks and birth weight ± 1.11 kg, i.e., 20 preterms diagnosed at Stage I, 12 preterms at Stage II, and 8 preterms at Stage III, were compared with age- and weight-matched preterms with no NEC.

Statistical Analysis:

The collected data were tabulated, coded, and then analyzed using the computer program Statistical Package for the Social Science (SPSS version 22).

Results:

Serum levels of I-FABP in NEC cases were significantly higher than the control group, with a mean of 6005.77 ± 6384.77 and 1480.79 ± 1276.48 pg/ml, respectively (P < 0.001). Urine levels of I-FABP in NEC cases were significantly higher than the control group, with a mean of 5009.22 ± 3941.64 and 2677.62 ± 2257.29 pg/ml, respectively (P = 0.04). Both serum and urine I-FABP levels not only in Stage II are significantly higher than Stage I but also in Stage III are significantly higher than Stage I and II (P < 0.001, P = 0.03, respectively), which showed significant positive correlation with stages of NEC (r = 0.618; P < 0.001; r = 0.306; P = 0.049, respectively). Both serum and urine I-FABP levels had a highly significant positive correlation with each other (r = 0.406 P < 0.0001). Receiving operating characteristic curve showed an area under the curve of 0.92 and 0.81 for serum and urine I-FABP, respectively.

Conclusions:

Whether serum or urinary I-FABP is valuable in the diagnosis and prediction of NEC and strongly correlated with the disease severity and with each other.

Lactate and intestinal fatty acid binding protein as essential biomarkers in neonates with necrotizing enterocolitis: ultrasonographic and surgical considerations

BACKGROUND

Necrotizing enterocolitis (NEC) is a neonatal disease with its pathogenesis still not well understood, although it is hypothesized to be related to decreased perfusion of the intestinal wall. The current study aimed to evaluate the plasma lactate levels and assess the validity of plasma and urinary intestinal fatty acid binding protein (I-FABPp and I-FABPu/Cr_u respectively) in NEC.

METHODS

The study included 55 neonates with variable Bell's stages who were comparable with 23 matched controls. Colorimetric assays of plasma lactate and ELISA assays of I-FABP in both serum and urine of the included neonates have been performed.

RESULTS

There were significantly higher median levels of I-FABPp, I-FABPu and lactate among cases (2.84 ng/ml, 1.74 ng/g creat. and 32.34 mg/dl, respectively) compared with controls (0.16 ng/ml, 0.60 ng/g creat. and 15.33 mg/dl, respectively) with p ˂ 0.05 for all. I-FABPp at cut-off point >3.24 ng/ml showed 90% sensitivity, 72% specificity, PPV = 52.6%, NPP = 94.7%, while for I-FABPu (at cut-off point > 2.93 ng/g creat.) those values were 90%, 92%, 81.8% and 95.8% respectively, in discriminating stage IIIA from stage II with p = 0.001. In predicting surgical NEC, I-FABPp at the cut-off point of 6.95 ng/ml revealed 75% sensitivity, 100% specificity, PPV = 100%, NPP = 95%, while for I-FABPu (cut-off point>4.13 ng/g creat.) they were 100%, 76.19%, 44.4 %and 100%, p = 0.04.

CONCLUSION

s: In addition to clinical judgment, sonographic data and plasma lactate, I-FABPp was shown to be a specific marker for early identification of surgical NEC, while I-FABPu could be more useful for differentiating Bell's stage II from stage III.

Prophylactic efficacy of enteral antifungal administration of miconazole for intestinal perforation, especially for necrotizing enterocolitis: a historical cohort study at a single institution

PURPOSE

Despite improvements in neonatal intensive care, the outcomes of extremely-low-birth-weight infants (ELBWIs) with surgical diseases remain to be improved. We started administering enteral miconazole (MCZ) to ELBWIs from 2002 to prevent fungal infection. Since then, the incidence of intestinal perforation has significantly decreased. We investigated this prophylactic effect of MCZ against necrotizing enterocolitis (NEC) and focal intestinal perforation (FIP) and explored a new prophylactic concept against intestinal perforation.

METHODS

We designed a historical cohort study to evaluate the effect of MCZ for intestinal perforation in ELBWIs who underwent treatment in our neonatal intensive-care unit between January 1998 and December 2005. We divided these cases into two groups: the Pre-MCZ group and the Post-MCZ group. We compared the morbidity, clinical outcomes and pathological features of NEC and FIP.

RESULTS

The rate of intestinal perforation with NEC was significantly reduced after the introduction of MCZ (p = 0.007, odds ratio; 3.782, 95% confidence interval; 1.368-12.08). The pathological findings of NEC specimens showed that the accumulation of inflammatory cells was significantly reduced in the Post-MCZ group when compared with the Pre-MCZ group (p < 0.05).

CONCLUSIONS

The efficacy of the enteral administration of MCZ on intestinal perforation with NEC highlights a new prophylactic concept in the clinical management of ELBWIs.

Use of intestine-related biomarkers for detecting intestinal epithelial damage in neonatal calves with diarrhea

OBJECTIVE

To evaluate the usefulness of intestinal biomarkers in determining the presence of intestinal epithelial damage in neonatal calves with diarrhea caused by 4 etiologic agents.

ANIMALS

40 neonatal calves that were healthy (n = 10) or had diarrhea (30).

PROCEDURES

The study was a cross-sectional study. Results of hematologic analyses and serum concentrations of intestinal fatty acid-binding protein (I-FABP), liver fatty acid-binding protein (L-FABP), trefoil factor 3 (TFF-3), Claudin-3 (CLDN-3), γ-enteric smooth muscle actin (ACTG2), intestinal alkaline phosphatase (IAP), interleukin-8 (IL-8), platelet-activating factor (PAF), and leptin (LP) were compared among calves grouped according to whether they were healthy (control group; G-1) or had diarrhea caused by K99 Escherichia coli (G-2; n = 10), bovine rota- or coronavirus (G-3; 5 each), or Cryptosporidium spp (G-4; 10).

RESULTS

Across the 3 time points at which blood samples were obtained and evaluated, the groups of calves with diarrhea generally had markedly higher mean serum concentrations of L-FABP, TFF-3, IAP, IL-8, and LP, compared with the control group. In addition, G-2 also consistently had markedly higher mean serum concentrations of I-FAB and ACTG2 and lower mean serum concentrations of CLDN-3, compared with the control group.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that degree of intestinal epithelial damage differed among calves grouped by the etiologic agent of diarrhea and that such damage might have been more severe in calves with diarrhea caused by K99 E coli. Additionally, our results indicated that serum concentrations of I-FABP, L-FABP, TFF-3, IAP, IL-8, ACTG2, LP, and CLDN-3 were useful biomarkers of intestinal epithelial damage in calves of the present study.

Beneficial Effect of Mildly Pasteurized Whey Protein on Intestinal Integrity and Innate Defense in Preterm and Near-Term Piglets

Background. The human digestive tract is structurally mature at birth, yet maturation of gut functions such as digestion and mucosal barrier continues for the next 1–2 years. Human milk and infant milk formulas (IMF) seem to impact maturation of these gut functions differently, which is at least partially related to high temperature processing of IMF causing loss of bioactive proteins and formation of advanced glycation end products (AGEs). Both loss of protein bioactivity and formation of AGEs depend on heating temperature and time. The aim of this study was to investigate the impact of mildly pasteurized whey protein concentrate (MP-WPC) compared to extensively heated WPC (EH-WPC) on gut maturation in a piglet model hypersensitive to enteral nutrition. Methods. WPC was obtained by cold filtration and mildly pasteurized (73 °C, 30 s) or extensively heat treated (73 °C, 30 s + 80 °C, 6 min). Preterm (~90% gestation) and near-term piglets (~96% gestation) received enteral nutrition based on MP-WPC or EH-WPC for five days. Macroscopic and histologic lesions in the gastro-intestinal tract were evaluated and intestinal responses were further assessed by RT-qPCR, immunohistochemistry and enzyme activity analysis. Results. A diet based on MP-WPC limited epithelial intestinal damage and improved colonic integrity compared to EH-WPC. MP-WPC dampened colonic IL1-β, IL-8 and TNF-α expression and lowered T-cell influx in both preterm and near-term piglets. Anti-microbial defense as measured by neutrophil influx in the colon was only observed in near-term piglets, correlated with histological damage and was reduced by MP-WPC. Moreover, MP-WPC stimulated iALP activity in the colonic epithelium and increased differentiation into enteroendocrine cells compared to EH-WPC. Conclusions. Compared to extensively heated WPC, a formula based on mildly pasteurized WPC limits gut inflammation and stimulates gut maturation in preterm and near-term piglets and might therefore also be beneficial for preterm and (near) term infants.

The Role of Gastrointestinal-Related Fatty Acid-Binding Proteins as Biomarkers in Gastrointestinal Diseases

The fatty acid-binding proteins play a major role in intracellular transportation of long-chain fatty acids. Nine fatty acid-binding proteins have been identified, with each having individual tissue-specific functions in addition to regulation of fatty acids. This review focuses on the three fatty acid-binding proteins found in the gastrointestinal tract and discusses their role as diagnostic or disease monitoring markers in neonatal necrotizing enterocolitis, acute mesenteric ischemia, celiac disease, and inflammatory bowel disease. Of these three fatty acid-binding proteins, intestinal fatty acid-binding protein is of the most interest due to its exclusive expression in the gastrointestinal tract. The elevation of intestinal fatty acid-binding protein in blood and urine reflects enterocyte damage, regardless of the underlying cause. The short half-life of intestinal fatty acid-binding protein also means it is a relatively sensitive marker. In contrast, there is currently less evidence to support liver fatty acid-binding protein and ileal bile acid-binding protein as sensitive biomarkers in these conditions. More extensive studies with specific endpoints are required to validate the roles of these fatty acid-binding proteins in gastrointestinal diseases.

Cardiac and Inflammatory Necrotizing Enterocolitis in Newborns Are Not the Same Entity

Background: Necrotizing enterocolitis (NEC) is an often-fatal neonatal disease involving intestinal hyperinflammation leading to necrosis. Despite ongoing research, (1) conflicting results and (2) comorbidities of NEC patients make early NEC detection challenging and may complicate therapy development. Most research suggests that NEC pathogenesis is multifactorial, involving a combination of (1) gut prematurity; (2) abnormal bacterial colonization; and (3) ischemia-reperfusion (I/R) injury. As neutrophil extracellular traps (NETs) partially mediate I/R injury and drive inflammation in NEC, we hypothesized that NETs contribute to NEC development; particularly in cardiac patients. Methods: A retrospective analysis of baseline characteristics, clinical signs, laboratory parameters, and imaging was conducted for surgically verified NEC cases over 10 years. Patients were stratified into two groups: (1) prior medically or surgically treated cardiac disease (cardiac NEC) and (2) no cardiac comorbidities (inflammatory NEC). Additionally, histology was reassessed for neutrophil activation and NETs formation. Results: A total of 110 patients (cNEC 43/110 vs. iNEC 67/110) were included in the study, with cNEC neonates being significantly older than iNEC neonates (p = 0.005). While no significant differences were found regarding clinical signs and imaging, laboratory parameters revealed that cNEC patients have significantly increased leucocyte (p = 0.024) and neutrophil (p < 0.001) counts. Both groups also differed in pH value (p = 0.011). Regarding histology: a non-significant increase in staining of myeloperoxidase within the cNEC group could be found in comparison to iNEC samples. Neutrophil elastase (p = 0.012) and citrullinated histone H3 stained (p = 0.041) slides showed a significant markup for neonates diagnosed with cNEC in comparison to neonates with iNEC. Conclusion: The study shows that many standardized methods for diagnosing NEC are rather unspecific. However, differing leucocyte and neutrophil concentrations for iNEC and cNEC may indicate a different pathogenesis and may aid in diagnosis. As we propose that iNEC is grounded rather in sepsis and neutropenia, while cNEC primarily involves I/R injuries, which involves neutrophilia and NETs formation, it is plausible that I/R injury due to interventions for cardiac comorbidities results in pronounced neutrophil activation followed by a hyperinflammation reaction and NEC. However, prospective studies are necessary to validate these findings and to determine the accuracy of the potential diagnostic parameters.

Necrotizing Enterocolitis: The Future

Progress in our understanding of the pathophysiology, prevention and treatment of necrotizing enterocolitis (NEC) has been hampered for many reasons. Included among these is the fact that what we are calling "NEC" is likely to represent different disease processes, which need to be delineated before evaluating individual pathogenic mechanisms and attempting to develop predictive and diagnostic biomarkers. Treatment is also likely to be hampered because not all of the different entities called "NEC" will respond to the same regimen. In this review, some of these entities will be discussed in more detail, with suggestions for refining our approach toward improving methods for their diagnosis, prevention and treatment.

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.

Interleukin-6 serum levels predict surgical intervention in infants with necrotizing enterocolitis

BACKGROUND

Symptoms at suspicion of necrotizing enterocolitis (NEC) are often nonspecific and several biomarkers have been evaluated for their discriminative power to both diagnose and predict the course from NEC suspicion to complicated disease requiring surgical intervention. Thus, we aimed to assess the utility of interleukin-6 (IL-6) to predict surgical intervention in infants suffering from NEC and, furthermore, to discriminate infants with starting NEC or late-onset sepsis (LOS).

METHODS

IL-6 serum levels at disease onset were retrospectively analyzed in 24 infants suffering from NEC as well as 16 neonates with LOS.

RESULTS

IL-6 serum levels at disease onset were significantly higher in infants suffering from NEC necessitating surgical intervention in the disease course compared to infants with medical NEC (5000 [785-5000] vs. 370 [78-4716] pg/ml, p = 0.0008) as well as gram-positive LOS (5000 [785-5000] vs. 84 [12-269] pg/ml, p = 0.0001). Infants suffering from gram-negative LOS exhibited elevated IL-6 serum levels at disease onset comparable to infants with surgical NEC (5000 [1919-5000] vs. 5000 [785-5000] pg/ml, p = 1.00).

CONCLUSION

The proinflammatory cytokine IL-6 appears to be a promising marker to distinguish surgical NEC from medical NEC at the onset of disease but cannot discriminate between surgical NEC and gram-negative LOS.

LEVEL OF EVIDENCE

II.

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.

Prophylactic application of laser light restores L-FABP expression in the livers of rats submitted to partial ischemia

OBJECTIVES

The objective of the present study was to evaluate the protective effect of pre-conditioning treatment with laser light on hepatic injury in rats submitted to partial ischemia using mitochondrial function and liver fatty acid binding protein as markers.

METHODS

Rats were divided into four groups (n=5): 1) Control, 2) Control + Laser, 3) Partial Ischemia and 4) Partial Ischemia + Laser. Ischemia was induced by clamping the hepatic pedicle of the left and middle lobes of the liver for 60 minutes. Laser light at 660 nm was applied to the liver immediately prior to the induction of ischemia at 22.5 J/cm2, with 30 seconds of illumination at five individual points. The animals were sacrificed after 30 minutes of reperfusion. Blood and liver tissues were collected for analysis of mitochondrial function, determination of malondialdehyde and analysis of fatty acid binding protein expression by Western blot.

RESULTS

Mitochondrial function decreased in the Partial Ischemia group, especially during adenosine diphosphate-activated respiration (state 3), and the expression of fatty acid binding protein was also reduced. The application of laser light prevented bioenergetic changes and restored the expression of fatty acid binding protein.

CONCLUSION

Prophylactic application of laser light to the livers of rats submitted to partial ischemia was found to have a protective effect in the liver, with normalization of both mitochondrial function and fatty acid binding protein tissue expression.

Point-of-Care Fecal Calprotectin Monitoring in Preterm Infants at Risk for Necrotizing Enterocolitis

OBJECTIVE

To establish baseline trends in fecal calprotectin, a protein excreted into the stool when there is neutrophilic inflammation in the bowel, in infants at risk for necrotizing enterocolitis (NEC).

STUDY DESIGN

We performed a prospective observational cohort study in infants with a birth weight of <1500 g without existing bowel disease at a level IV neonatal intensive care unit from October 2015 to September 2016. Stools were collected once daily for 30 days or until 32 weeks postmenstrual age and processed using the Fecal Calprotectin High Range Quantitative Quantum Blue assay.

RESULTS

In 64 preterm infants, during the first week after birth, 62% of infants had an initial stool sample with high baseline calprotectin levels (≥200 µg/g). In assessment of maternal and neonatal risk factors, maternal etiology for preterm birth (ie, eclamplsia or preeclampsia) was the only significant factor associated with high baseline calprotectin level. Two patients in the cohort developed NEC. Calprotectin levels for the entire cohort fluctuated during the observed period but generally increased in the third and fourth weeks after birth.

CONCLUSIONS

At-risk infants had highly variable fecal calprotectin levels, with maternal causes for preterm birth associated with higher baseline levels. More longitudinal data in infants with NEC are necessary to determine whether acute rises in fecal calprotectin levels prior to clinical diagnosis can be confirmed as a diagnostic or prognostic biomarker.

Preterm Life in Sterile Conditions: A Study on Preterm, Germ-Free Piglets

Preterm infants born with immature organ systems, which can impede normal development, can also be highly sensitive to different biological and/or environmental factors. Animal models could aid in investigating and understanding the effects of different conditions on the health of these immunocompromised infants. The epitheliochorial placentation of the pig prevents the prenatal transfer of protective colostral immunoglobulins. Surgical colostrum-deprived piglets are free of maternal immunoglobulins, and the cells that are normally provided via colostrum. We bred preterm germ-free piglets in sterile conditions and compared them with their term counterparts. Enterocyte development and intestinal morphology, tight junction proteins claudin-1 and occludin, pattern-recognizing receptors, adaptor molecules and coreceptors (RAGE, TLR2, TLR4, TLR9, MyD88, TRIF, MD2, and CD14), and inflammasome NLRP3 transcription were all evaluated. The production of inflammatory mediators IFN-α, IL-4, IL-6, IL-8, IL-10, IL-12/23 p40, TNF-α, IFN-γ, and high mobility group box 1 (HMGB1) in the intestine of germ-free piglets was also assessed. In the preterm germ-free piglets, the ileum showed decreased lamina propria cellularity, reduced villous height, and thinner and less distinct stratification - especially muscle layer, in comparison with their term counterparts. Claudin-1 transcription increased in the intestine of the preterm piglets. The transcription levels of pattern-recognizing receptors and adaptor molecules showed ambiguous trends between the groups. The levels of IL-6, IL-8, IL-10, and TNF-α were increased in the preterm ileum numerically (though not significantly), with statistically significant increases in the colon. Additionally, IL-12/23 p40 and IFN-γ were statistically significantly higher in the preterm colon. Both blood plasma and intestinal HMGB1 levels were nonsignificantly higher in the preterm group. We propose that the intestine of the preterm germ-free piglets showed "mild inflammation in sterile conditions." This model, which establishes preterm, hysterectomy-derived germ-free piglets, without protective maternal immunoglobulins, can be used to study influences of microbiota, nutrition, and therapeutic interventions on the development and health of vulnerable immunocompromised preterm infants.

Early microbial colonization affects DNA methylation of genes related to intestinal immunity and metabolism in preterm pigs

Epigenetic regulation may play an important role in mediating microbe-host interactions and adaptation of intestinal gene expression to bacterial colonization just after birth. This is particularly important after preterm birth because the immature intestine is hypersensitive to invading bacteria. We compared the intestinal DNA methylome and microbiome between conventional (CON) and antibiotics-treated (AB) preterm pigs, used as a model for preterm infants. Oral AB treatment reduced bacterial density (∼100-fold), diversity and fermentation, improved the resistance to necrotizing enterocolitis (NEC) and changed the genome-wide DNA methylation in the distal small intestine. Integration of epigenome data with previously obtained proteome data showed that intestinal immune-metabolic pathways were affected by the AB-induced delay in bacterial colonization. DNA methylation and expression of intestinal genes, related to innate immune response, phagocytosis, endothelial homeostasis and tissue metabolism (e.g. CPN1, C3, LBP, HIF1A, MicroRNA-126, PTPRE), differed between AB and CON pigs even before any evidence of NEC lesions. Our findings document that the newborn immature intestine is influenced by bacterial colonization via DNA methylation changes. Microbiota-dependent epigenetic programming of genes related to gut immunity, vascular integrity and metabolism may be critical for short- and long-term intestinal health in preterm neonates.

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.

Predictive and diagnostic value of serum intestinal fatty acid binding protein in neonatal necrotizing enterocolitis (case series)

Objectives

In this study, we aimed to investigate the value of serum intestinal fatty acid binding protein (I-FABP) in early diagnosis and predicting the severity of Necrotizing enterocolitis (NEC).

Methods

This prospective study was performed on 160 preterm neonates ageing less than 35 weeks and weighting less than 2000 gm selected from the Neonatal Intensive Care Units (NICUs) of the Pediatric Department at Benha University hospital and Benha children hospital to evaluate which of them will develop NEC, after follow-up these neonates were divided into two groups: Group one compromised eighteen preterm neonates with symptoms and signs of NEC. Group two compromised ten preterm neonates as a control group. All participants were subjected to full clinical examination, abdominal X-ray and serum I-FABP.

Results

The 1st values of IFABP taken at birth showed that mean serum IFABP concentrations of the study group were higher than that of the control group. The 2nd values of serum IFABP taken at the start of feeding showed that mean IFABP concentrations of the study group were higher in comparison with IFABP at birth. In the 3rd values of serum, IFABP taken at the time of diagnosing NEC showed that mean serum IFABP concentrations of the study group were higher than the control group. In the 4th values of serum, IFABP taken one week after diagnosing NEC showed that the mean serum IFABP concentrations of the study group became significantly decreased in comparison with IFABP at the time of diagnosis in stage 1 and 2.

Conclusions

Serial measurements of serum I-FABP levels may be a useful marker for early diagnosis and prediction of disease severity in NEC.

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This prospective study was performed on preterm neonates selected from the Neonatal Intensive Care Units (NICUs) of the Pediatric Department at Benha University hospital and Benha children hospital.

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The 1st values of IFABP taken within birth showed that mean serum IFABP concentrations of study group were higher than that of the control group. The 2nd values of serum IFABP taken at start of feeding showed that mean IFABP concentrations of study group were higher in comparison with IFABP at birth. In the 3rd values of serum IFABP taken at time of diagnosing NEC showed that mean serum IFABP concentrations of study group were higher than the control group.

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In the 4th values of serum IFABP taken one week after diagnosing NEC showed that the mean serum IFABP concentrations of the study group became significantly decreased in comparison with IFABP at time of diagnosis in stage 1 and 2.

Infantile Colic Is Associated With Low-grade Systemic Inflammation

OBJECTIVES

Dysbiosis, an imbalance in the taxonomic composition of the gut bacteria occurring during the critical stages of development, induces lasting shifts in the immunological and metabolic phenotype if accompanied by an inflammatory response. Because altered gut microbiota and successful treatment with probiotics have both been demonstrated in cases of colic, we hypothesized here that infants with colic might have low-grade inflammation.

METHODS

In 28 infants with colic and in 12 healthy controls at the age of 1 month, we measured the following serum immunological biomarkers: cytokines interleukin 1β (IL-1β); IL-6; IL-10; tumor necrosis factor α; interferon γ (IFN-γ); chemokines IL-8; monocyte chemotactic protein-1 (MCP-1); macrophage inflammatory protein 1β (MIP-1β) and chemokine (C-X-C motif) ligand 16; and intestinal fatty acid-binding protein, a biomarker of enterocyte damage and zonulin, a biomarker of intestinal permeability. In addition, intestinal microbiota composition was correlated with immunological biomarkers.

RESULTS

Infants with colic had increased concentrations of IL-8, MCP-1, and MIP-1β in serum as compared with healthy children. All the other immunological biomarkers were comparable between the groups. Fecal levels of Clostridium leptum correlated negatively with the proinflammatory markers MCP-1 (r = -0.44, P = 0.02), MIP-1β (r = -0.43, P = 0.02), and tumor necrosis factor α (r = -0.38, P = 0.04). In addition, C coccoides group levels correlated negatively with MCP-1 (r = -0.43, P = 0.02) and Bifidobacterium breve levels positively with chemokine (C-X-C motif) ligand 16 (r = 0.38, P = 0.04).

CONCLUSIONS

In addition to gut microbiota alterations, colic in infants is associated with low-grade systemic inflammation. Specific bacterial species beyond conventional probiotics may have anti-inflammatory properties that may help to modulate microbiota and alleviate colic-related inflammation.

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.

Current Research on the Epidemiology, Pathogenesis, and Management of Necrotizing Enterocolitis

Despite decades of research on necrotizing enterocolitis, we still do not fully understand the pathogenesis of the disease, or how to prevent or how to treat it. However, as a result of recent significant advances in the microbiology, molecular biology, and cell biology of the intestine of preterm infants and infants with necrotizing enterocolitis, there is some hope that research into this devastating disease will yield some important translation into effective prevention, more rapid diagnosis, and novel therapies.

Diagnostic Value of Intestinal Fatty-Acid-Binding Protein in Necrotizing Enterocolitis: A Systematic Review and Meta-Analysis

The present study was undertaken to evaluate the performance of intestinal fatty-acid-binding protein (i-FABP) in the diagnosis of newborn necrotizing enterocolitis (NEC) and prediction of surgical NEC. A comprehensive literature search was performed in PubMed and EMBASE to identify potential relevant studies. QUADAS-2 tool was used to assess the quality of the included studies. The sensitivity, specificity and other measurements of accuracy of i-FABP were pooled. Summary receiver operating characteristic curves (SROC) and area under the curve (AUC) were used to summarize overall diagnostic performance. After screening 150 titles and abstracts, followed by 32 full-text publications, 14 studies were included. The sample size, sensitivity, specificity, diagnostic odds ratio (DOR) and AUC were: plasma i-FABP 217, 0.64(95% CI 0.53 to 0.74), 0.91(95% CI 0.84 to 0.95), 14.22 (95%CI 6.42 to 31.52) and 0.84; urinary i-FABP 211, 0.64(95% CI 0.53 to 0.74), 0.73(95% CI 0.64 to 0.80), 6.35 (95%CI 3.17 to 12.72) and 0.81; urinary i-FABP/Cr 165, 0.78(95% CI 0.65 to 0.88), 0.75(95% CI 0.65 to 0.82), 6.35 (95%CI 3.17 to 12.72) and 0.81; plasma i-FABP for surgical NEC 45, 0.71(95% CI 0.51 to 0.87), 0.76(95% CI 0.50 to 0.93), 7.58 (95%CI 0.87 to 65.82) and 0.80. Plasma i-FABP is a promising biomarker in the diagnosis of NEC with high specificity and DOR; but its usefulness is limited because of medium sensitivity. The urinary i-FABP and urinary i-FABP/Cr add little value in the diagnosis. The findings were somewhat limited by the quality and small size of some of the studies included.

Prophylactic efficacy of enteral miconazole administration for neonatal intestinal perforation and its potential mechanism

PURPOSE

Intestinal perforation (IP) is a fatal complication in extremely low birth weight infants (ELBWI). We started administrating enteral miconazole (MCZ) to ELBWI in 2002. Since then, the incidence of IP has significantly decreased. The aim of this study was to elucidate the prophylactic effect of MCZ for the treatment of neonatal IP, and to establish a new prophylactic concept for this disease.

METHODS

In in vivo experiments, the effects of MCZ were examined histopathologically using a mouse model of intestinal ischemia. In in vitro experiments, the cytoprotective effect of MCZ against hypoxia was evaluated using Caco-2 intestinal cells, and its anti-inflammatory potential using a co-culture model of Caco-2 and HL60 cells.

RESULTS

MCZ showed a tissue protective effect against intestinal ischemia. MCZ reduced high mobility group-box 1 (HMGB1) release in Caco-2 cells under hypoxic stress and attenuated the potential to activate co-cultured HL60 leukocytes with Caco-2 cells by suppressing interleukin-8 (IL-8).

CONCLUSION

MCZ may have preventive roles in the clinical management of IP in ELBWI by the suppression of IL-8 and HMGB-1.

Plasma intestinal fatty acid-binding protein fails to predict endoscopic disease activity in inflammatory bowel disease patients

BACKGROUND

Monitoring disease activity in inflammatory bowel disease (IBD) is of major importance to prevent long-term complications. Intestinal fatty acid-binding protein (I-FABP) has been identified as a marker for intestinal damage and correlates with the degree of inflammation. The aim of the present study was to evaluate whether I-FABP can predict active disease or remission in Crohn's disease (CD) and ulcerative colitis (UC) in a real-life IBD cohort.

METHODS

In total, 70 patients with endoscopic disease activity available and 194 patients with disease activity on the basis of a stringent combi-score of clinical activity index, C-reactive protein, and fecal calprotectin were included. Plasma I-FABP was compared between patients with active disease and remission. In a small subgroup of CD patients, follow-up samples were analyzed.

RESULTS

In CD (139.2 vs. 119.2 pg/ml; P=0.37) and UC (107.8 vs. 151.8 pg/ml; P=0.33), the median I-FABP did not differ in endoscopic active disease versus remission. In UC patients with active disease on the basis of the combi-score, the median I-FABP (106.8 vs. 172.0 pg/ml; P=0.03) was significantly lower than in patients in remission, but not in CD (145.5 vs. 157.5 pg/ml; P=0.29). Neither disease location in CD nor extent of disease in UC influenced I-FABP significantly. I-FABP was not different (P=0.78) in CD patients with a change in disease activity over time.

CONCLUSION

Plasma I-FABP did not differ between endoscopic active disease and remission in both CD and UC. I-FABP was lower in active UC but not CD on the basis of the combi-score. On the basis of these findings, I-FABP has no potential as a novel noninvasive biomarker for disease activity in IBD.

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.

Controlling the cytokine storm in severe bacterial diarrhoea with an oral Toll-like receptor 4 antagonist

Shigella dysenteriae causes the most severe of all infectious diarrhoeas and colitis. We infected rhesus macaques orally and also treated them orally with a small and non-absorbable polypropyletherimine dendrimer glucosamine that is a Toll-like receptor-4 (TLR4) antagonist. Antibiotics were not given for this life-threatening infection. Six days later, the clinical score for diarrhoea, mucus and blood was 54% lower, colon interleukin-8 and interleukin-6 were both 77% lower, and colon neutrophil infiltration was 75% less. Strikingly, vasculitis did not occur and tissue fibrin thrombi were reduced by 67%. There was no clinical toxicity or adverse effect of dendrimer glucosamine on systemic immunity. This is the first report in non-human primates of the therapeutic efficacy of a small and orally bioavailable TLR antagonist in severe infection. Our results show that an oral TLR4 antagonist can enable controlled resolution of the infection-related-inflammatory response and can also prevent neutrophil-mediated gut wall necrosis in severe infectious diarrhoeas.

Bloodstream infections during the onset of necrotizing enterocolitis and their relation with the pro-inflammatory response, gut wall integrity and severity of disease in NEC

INTRODUCTION

Bacterial involvement is believed to play a pivotal role in the development and disease outcome of NEC. However, whether a bloodstream infection (BSI) predisposes to NEC (e.g. by activating the pro-inflammatory response) or result from the loss of gut wall integrity during NEC development is a longstanding question.

OBJECTIVE

We hypothesize that the occurrence of a BSI plays a complementary role in the pathogenesis of NEC. The first aim of the study was to correlate the occurrence of a BSI during the early phase of NEC with intestinal fatty acid-binding protein (I-FABP) levels, as a marker for loss of gut wall integrity owing to mucosal damage, and Interleukin (IL)-8 levels, as a biomarker for the pro-inflammatory cascade in NEC. The second aim of the study was to investigate the relation between the occurrence of a BSI and disease outcome.

MATERIAL AND METHODS

We combined data from prospective trials from two large academic pediatric surgical centers. Thirty-eight neonates with NEC, 5 neonates with bacterial sepsis, and 14 controls were included.

RESULTS

BSIs occurred in 10/38 (26%) neonates at NEC onset. No association between the occurrence of BSIs and I-FABP levels in plasma (cohort 1: median 11ng/mL (range 0.8-298), cohort 2: median 6.8ng/mL (range 1.3-15)) was found in NEC patients (cohort 1: p=0.41; cohort 2: p=0.90). In addition, the occurrence of BSIs did not correlate with IL-8 (median 1562pg/mL (range 150-7,500); p=0.99). While the occurrence of a BSI was not correlated with Bell's stage (p=0.85), mortality was higher in patients with a BSI (p=0.005).

CONCLUSION

The low incidence of BSIs and the absent association of both the markers for loss of gut wall integrity and the pro-inflammatory response during the early phase of NEC, support the hypothesis that the presence of a BSI does not precede NEC.

Urine biomarkers for necrotizing enterocolitis

Necrotizing enterocolitis (NEC) remains a significant cause of morbidity and mortality in premature neonates. Despite decades of investigation, treating clinicians are still not able to determine which premature infants are at greatest risk of developing NEC and which of the affected infants will develop severe NEC requiring operation. A biomarker is a specific molecular indicator that can be used to identify or measure the progress of a disease. Many potential biomarkers have been studied for their potential relevance to NEC. Those showing promise include C-reactive protein, intestinal fatty acid-binding protein, platelet-activating factor and many others. None to date have achieved sufficient predictive value to be clinically useful. Distinguishing between the specific changes in NEC and the non-specific inflammation of sepsis has proven challenging. Urine is a particularly attractive site for potential biomarkers. It can be collected readily and non-invasively, and it is a rich source of both proteins and peptides. Preliminary work has revealed some promising biomarkers of NEC in urine. Combined with clinical data, they have been shown to be highly predictive in small series of patients. Advances in high-throughput molecular analysis have opened the door to finding biomarkers that may meaningfully improve the outcome of infants at risk for NEC.

Intestinal fatty acid-binding protein as a diagnostic marker for complicated and uncomplicated necrotizing enterocolitis: a prospective cohort study

Background

Early NEC symptoms are non-specific and diagnostic tests lack discriminative power. Intestinal fatty acid-binding protein (I-FABP), mainly located in small bowel enterocytes, is released into the blood following NEC-associated enterocyte disruption. Aim of this prospective cohort trial was to determine the diagnostic value of I-FABP measured in plasma (I-FABPp) and urine (I-FABPu) for the presence of NEC, to evaluate I-FABP levels during NEC development, and to assess its prognostic value for the progression from suspected to complicated disease.

Methods

Between 2010 and 2012 we prospectively enrolled neonates with suspected NEC. We measured I-FABP levels eight-hourly from onset of suspected NEC for at least 48 hours, or until surgery. NEC diagnosis was confirmed radiologically or during operation. We defined NEC as complicated if it resulted in surgery and/or death. We determined disease course and diagnostic I-FABP cut-off points.

Results

The study comprised 37 neonates (24M, 13F), gestational age 28 (24–36) weeks, birth weight 1190 (570–2,400) grams. We found significantly higher I-FABPp and I-FABPu levels in NEC patients (n = 22) than in patients with other diagnoses (n = 15). Cut-off values for diagnosing NEC were 9 ng/mL I-FABPp and 218 ng/mL I-FABPu, with corresponding likelihood ratios (LRs) of 5.6 (95% CI 0.89–35) and 5.1 (95% CI 0.73–36), respectively. I-FABP levels were highest in the first eight hours after symptom onset and gradually decreased over time. Cut-off values for complicated disease were 19 ng/mL I-FABPp and 232 ng/mL I-FABPu, with LRs of 10 (95% CI 1.6–70) and 11 (95% CI 1.6–81), respectively.

Conclusions

Both plasma and urinary I-FABP levels specifically identify NEC in preterm infants prior to appearance of diagnostic radiological signs suggestive for NEC. Moreover, serial I-FABP measurements accurately predict development of complicated disease.