TY - JOUR
AU - , de Boer, Nanne K. H.
AB - Abstract 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. necrotizing enterocolitis, review, microbiota, biomarkers, predictive model, volatile organic compounds Necrotizing enterocolitis (NEC) is a common gastrointestinal disease in premature born and low-birth–weight neonates and is one of the leading causes of morbidity and mortality at neonatal intensive care units.1 The incidence of NEC in very low-birth–weight infants ranges between 3% and 15% with a high mortality rate varying between 15% and 30%.2 The incidence rates of NEC have increased over the last decades, largely attributable to an increased survival of extremely low-birth–weight infants, who are at the highest risk of developing NEC. This devastating disease puts an enormous burden on health care system expenses, illustrated by the estimation that financial costs in the United States are up to $1 billion yearly.3 This can be ascribed to prolonged hospitalization in the early phase and to long-term complications of survivors, including neurodevelopmental delay, short bowel syndrome, recurrent systemic infections, and parenteral nutrition-associated liver disease. Early detection and initiation of treatment in NEC are key factors in its course and prognosis. In the diagnostic workup of NEC, clinical and characteristic radiological findings remain the most important tools so far. Unfortunately, these signs are usually detectable in an advanced stage of disease. Therapeutic strategies of NEC consist of cessation of feeding, nasogastric decompression and broad systemic antibiotics, and, in particular cases, surgery. These precautions are most effective when started at early stage. Hence, to reduce the disturbingly high mortality rate, there is an ongoing need for novel preventive strategies and noninvasive diagnostic biomarkers for early and accurate detection of NEC. Of preventive and diagnostic importance may be the gut microbiota. The indigenous gut microbiota has increasingly been described as a key player in the pathogenesis of NEC. Therefore, many studies focused on the development of biomarkers reflecting NEC-specific shifts in microbiotal composition and on prophylactic strategies targeted at manipulation of the early neonatal microbiota colonization. In this article, we review the microbiota-related factors involved in NEC and describe the potential of noninvasive biomarkers and future perspectives on their use in the (early) detection of NEC. Pathogenesis From an historical perspective, NEC was considered to result primarily from ischemic mucosal injury in an immature gut of preterm very low-birth–weight infants.4 More recent studies have shown that the development of NEC better fits a multifactorial model, including both antenatal and postnatal factors. Chorioamnionitis but also maternal antibiotic usage are considered antenatal risk factors.5 Postnatal factors include dysregulation of the immune system, altered gut motility, reduced enzymatic function, altered mucus production and composition, reduced innate defense mechanisms, rapid introduction and advancement of enteral feeding alongside intestinal hypoxia-ischemia-reperfusion, formula and not human milk, and disturbance of normal neonatal gut colonization.6,7 All these factors may provoke an inappropriate inflammatory response in an immature intestine,8 inducing activation of (inflammatory) cytokines, decreased epidermal growth factor, increased platelet-activating factor, and progressive mucosal damage by free radical production, which may subsequently lead to development of NEC. Microbiota and NEC Studies describing microbial composition in neonates with NEC have rapidly expanded in the last decade, by the availability of DNA-based high-throughput detection techniques, instead of culture-based methods. This has made it feasible to unravel the highly complex microbiota composition of the human intestinal tract. The currently assumed role of the intestinal microbiota in the development of NEC results from a wide range of observations. Protective effects on the development of NEC of oligosaccharides in breast milk, by stimulation of protective bifidobacteria and inhibition of the growth of coliforms and other pathogenic organisms, have already been described several decades ago.9,10 Interestingly, outbreaks of NEC are reported in clusters and also seasonal variation in presentation has been observed, suggesting an infectious origin.11,12 Moreover, NEC is typically diagnosed beyond the first week of age. From this age on, anaerobic bacteria have commenced to colonize the infant gut, including pathogens triggering inflammatory processes. Furthermore, in animal studies on experimental NEC, bacteria have been ascribed a pivotal role, since NEC does not occur in a germ-free environment but can only develop following exposure to microbes.13 The efficacy of antibiotics in the treatment of NEC and reduction in incidence following prophylactic administration of probiotics both indirectly link NEC to the intestinal microbiota. That not all bacteria act similarly is shown in a neonatal (preterm) pig model where some strains in probiotic mixtures are increasing the risk of NEC.14 Dysbiosis, defined as a disturbance in the precarious balance between beneficial protective species versus harmful intestinal bacteria, was already described in 1975 as a provocative factor in NEC pathogenesis.15 Later studies reported that mainly Clostridial species (including Clostridium perfringens, C. butyricum, and C. neonatale) were involved in the etiology of NEC.16,–19 In 2004, de la Cochetiere et al20 reported an association between early colonization with C. perfringens and development of NEC. However, this assumed role for Clostridia was not confirmed in more recent studies, in which differences in microbial colonization between children with NEC and controls were mainly observed within the phylum Proteobacteria.21,–25 A predominance of Proteobacteria was observed in fecal samples of NEC cases up to 2 weeks before the clinical development of NEC, suggesting that dysbiosis predate the onset of NEC.24 Interestingly, in one study describing the microbiota composition at 2 different time points before diagnosis of NEC, a lower proportion of Proteobacteria was observed in infants 1 week before the diagnosis of NEC compared with controls, with an excessive increase of Proteobacteria in the following days.21 According to the authors, insufficient colonization with Proteobacteria early in preterm life may lead to a disturbed immune tolerance, provoking an exaggerated intestinal inflammation response and subsequently NEC, when exposed to an excessive increase of Proteobacteria later in life. Others reported more detailed NEC-specific differences in fecal microbiota composition, like colonization with Citrobacter-like sequences and Sphingomonas spp. Reports on overall diversity and abundance of enterococcal populations are contradictory, some studies have described reduced diversity and depletion of enterococcal microbes in NEC samples, a finding that could not be confirmed in other studies.24,26,27 In only few studies, no differences in microbial composition were noticed, like in a recent study from Normann et al.28 Comparing microbial communities in fecal samples from 10 children with NEC and 10 controls by means of 454 pyro-sequencing, no statistically significant differences were observed between the 2 groups. In the same study, the 2 groups could also not be differentiated based on microbiota analysis in mothers' milk and fecal samples of mothers of the subjects. In summary, the majority of studies on intestinal microbiota composition in NEC described disease-specific abnormalities as compared with controls. This enforces microbiota profiling, and biomarkers reflecting compositional disturbances, as a potential future diagnostic tool to detect (early) NEC. Reported findings differ highly across studies, and no single causative bacterial agent or NEC-specific microbiotal signature has been identified yet. This might be explained by differences in applied (logistical) procedures and used detection techniques, and by sampling during different institutional outbreaks, in which different pathogens might be involved. Diagnosis NEC typically presents in the second week of life, when enteral feedings (especially cow's milk based formula) are introduced. Age of presentation is inversely related to gestational age, especially extremely preterm infants may develop NEC at later time points. The peak age of presentation is at 29 to 31 weeks postmenstrual age.7,29 A recent large cohort study showed a bimodal distribution of NEC, with presentation at 8 and 19 postnatal days.2 Clinically, NEC can present with both gastrointestinal and nonspecific systemic signs as delayed gastric emptying, abdominal distention or tenderness (or both), bloody stools, lethargy, apnea, respiratory distress, or poor perfusion. Progression of NEC typically leads to abdominal tenderness and guarding, abdominal wall erythema or ecchymosis with a shiny appearance, or palpable distended loops of bowel. Abdominal wall erythema is strongly predictive of NEC but present in only 10% of affected patients.30 A blue or discolored abdomen may be a sign of bowel perforation.31 Because early clinical signs of NEC usually lack specificity, NEC might be difficult to differentiate from sepsis. The course of NEC also widely differs, nonspecific signs can slowly progress over several days, but NEC may also present with a fulminant onset of gastrointestinal signs and shock with multiorgan failure within only several hours. Laboratory findings in patients with NEC can include increased or decreased white blood cell count (with left shift of neutrophils), thrombocytopenia (a rapid drop in platelet count being a poor prognostic sign), metabolic acidosis, hypoglycemia or hyperglycemia and electrolyte imbalance, but all have low specificity.32,33 Bloodstream infection mostly with Gram-negative bacteria is present in 43% of the NEC cases, which is remarkable as the mucosal barrier of the intestines is completely disrupted.6,34 Nonspecific radiographic signs of NEC include thickened bowel walls, dilated bowel loops, paucity of bowel gas, and a fixed dilated loop. The latter observation may indicate necrotic bowel. Dilated gas-filled loops central in the abdomen may be a sign of ascites or free peritoneal fluid. Paucity of intestinal air may be caused by intestinal compression. Although these signs lack specificity for NEC, they are nonreassuring and require further investigation.35,36 Pneumatosis intestinalis is a pathognomonic radiological finding of NEC, reflecting presence of gas within the bowel wall. Pneumatosis is commonly detected in the right lower abdominal quadrant. The magnitude of pneumatosis does not always relate to the severity of NEC, and its disappearance does not necessarily implicate clinical improvement.35,–38 When the present gas becomes absorbed into the mesenteric circulation, it may result in portal venous gas, which can be recognized as a linear air dense area in the hepatic region on a plain x-ray. Alternatively, it can be easily detected by ultrasound. Portal venous gas is related to the severity of the disease39 but not to mortality or to the need of surgical intervention.40 The most relevant radiological finding of NEC is the presence of pneumoperitoneum, which is caused by perforation of the bowel wall. On plain abdominal radiograph, pneumoperitoneum can be recognized as the aspect of a (American) football, with the appearance of a longitudinal strip of sutures from a football caused by the falciform ligament. A small amount of free air may present as a small triangular or rectangular lucencies. A cross-table lateral or left lateral decubitus film (the infant is placed on its left side with horizontal radiation beam) may help in establishing the diagnosis of free air.35,41,–43 Abdominal ultrasonography may be helpful in the diagnostic process of NEC. It can detect pneumatosis, portal venous gas, pneumoperitoneum and decreased perfusion of the bowel. Moreover, ultrasonography can exclude other gastrointestinal abnormalities, like intestinal malrotation and volvulus, which clinical symptoms may resemble NEC. However, ultrasonography is highly operator dependent, limiting its use in clinical practice. Other imaging studies like contrast studies, computed tomography and magnetic resonance imaging have currently no additional value in the diagnostic workup and follow-up of NEC.35,44 Notably, extremely preterm infants have a different set of clinical symptoms at presentation of NEC. They are more likely to present with abdominal distention, ileus, and emesis. Abdominal tenderness and guarding may only be present in advanced stages but may also be completely absent.3,29 On plain radiography, preterm infants are less likely to present with pneumatosis intestinalis and portal venous gas, but they are at increased risk to develop pneumoperitoneum.29 The modified Bells staging criteria by Walsh and Kliegman is used to construct a grading system, and incorporate clinical symptoms, laboratory indices and radiological findings (Table 1). This can be helpful to define severity of illness and to select adequate treatment in routine clinical practice.45 Table 1. Staging System of NEC According to Walsh and Kliegman45 Open in new tab Table 1. Staging System of NEC According to Walsh and Kliegman45 Open in new tab Treatment Therapeutic strategies of newborns with NEC mainly consist of 2 streams: patients who can be treated medically (nonsurgical) and those patients who are in need of a surgical intervention. Medical The mainstay of the treatment of NEC is medical stabilization and conservation of general homeostasis. This regime typically consists of abdominal decompression, bowel rest, parenteral feeding with sufficient protein intake and administration of intravenous antibiotics. Abdominal decompression can be achieved by a double lumen gastric tube with continuous or intermittent suctioning. Significant aspirated volumes should be replaced.41,43 Antibiotic therapy usually consists of ampicillin (or cephalosporin) combined with an aminoglycoside. In case of peritonitis or bowel perforation, the addition of metronidazole or clindamycin is warranted to cover anaerobic bacteria.43 In the Netherlands, amoxicillin with clavulanic acid in combination with aminoglycoside, or alternatively meropenem, is administered to achieve immediate anaerobic coverage. Antibiotic therapy is guided by routine culture outcomes. Antibiotic treatment and bowel rest should be continued during 5 to 7 days in case of NEC stage II and 10 days in case of NEC stage III.7 With NEC stage I, the necessity of initiation and duration of antibiotic treatment is based on the judgment of the team of treating physicians.36 As the level of urinary intestinal fatty acid binding proteins at time of start of enteral feeding after NEC was correlated to adverse outcomes, this biomarker may help in timing of recommencing enteral feeding.46 Further supportive treatment consists of intubation in case of respiratory insufficiency, inotropic support when indicated, adequate fluid resuscitation and correction of anemia, thrombocytopenia and electrolyte imbalances. Therefore, blood counts and electrolytes should be closely monitored. To anticipate fluid loss to the third space, maintenance fluid has to be increased with 50% plus replacement of gastric output.41 Since NEC is considered to be painful, adequate pain control and minimal handling are important aspects of medical management.41 During the course of NEC, the affected newborn must frequently be reassessed to timely detect clinical deterioration and presence of pneumoperitoneum, which warrants surgical intervention. It must be kept into mind that by the time very preterm infants manifest tenderness or abdominal mass, NEC has usually progressed to an advanced stage.29 Therefore, serial abdominal radiographs (every 6–24 h and in case of clinical worsening or increase in abdominal girth) guide optimal treatment.35 Abdominal ultrasonography may also help in detecting intraperitoneal air and bowel necrosis.44 At last, serial C-reactive protein (CRP) measurements may be helpful for the detection of complications, like strictures or abscesses, or the need for surgical intervention.47 Surgical About 20% to 40% of newborns with NEC eventually require surgical intervention.7 However, many aspects of surgical intervention are still subject to discussion. At first, indication and timing of surgical intervention are challenging. Bowel perforation and necrotic bowel are absolute indications for surgery. Bowel perforation can be diagnosed by detection of pneumoperitoneum on abdominal radiographs. Bowel necrosis is suggested by persistent metabolic acidosis or thrombocytopenia, together with lack of improvement following medical treatment.48 Also palpable fixed abdominal mass and abdominal wall erythema are highly specific signs of bowel necrosis, but with limited sensitivity.30 Besides, a fixed bowel loop on abdominal radiograph is suggestive of necrotic bowel. Although portal venous gas was related to disease severity, it should not lead to surgical intervention when this is the only feature present.36 Pneumoperitoneum and bowel necrosis may be difficult to diagnose, especially in extremely preterm infants. For example, pneumoperitoneum can be missed in 20% of the cases of bowel perforation and negative laparotomy is just as detrimental as failure to early recognize a perforation.35,43 When surgical intervention is warranted, 2 different kinds of primary surgery are currently available: primary peritoneal drainage (PPD) and laparotomy. Two recent randomized controlled trials have compared PPD versus laparotomy.49,50 A Cochrane meta-analysis of these 2 studies concluded that there were no significant differences between the 2 groups, with respect to mortality and total duration of parental nutrition.51 However, these studies did not distinguish between NEC and focal intestinal perforation. The European Necrotizing Enterocolitis Trial50 included infants <1000 g. Of the infants who were treated with primary PPD, 74% still needed rescue laparotomy. In another nonrandomized study, worse survival rates and neurodevelopmental outcomes at 18 and 22 months were found in the infants who received PPD as primary therapy. It remains questionable whether there is a role for PPD in affected infants who are considered too instable for laparotomy.52 The classic surgical approach during laparotomy is to remove all areas of necrotic intestine and to exteriorize the bowel to allow adequate time for healing before restoring the intestinal continuity at later age.41 However stomas, especially jejunostomas, are poorly tolerated by preterm infants as they predispose to nutritional and metabolic disturbances and poor growth as a consequence of fluid and electrolyte disturbances. Therefore, some surgeons advocate a primary anastomosis.53 Currently, a randomized controlled trial studying resection and stoma's versus primary anastomosis is recruiting patients for inclusion (ISRCTN01700960). Toward Better Diagnosis and Treatment of NEC: Predictive Models and Biomarkers As stated previously, 2 major dilemmas are encountered in daily clinical practice concerning diagnosis of NEC. First, differentiation between early NEC and sepsis can be difficult or even impossible, which may lead to a delay in adequate diagnosis and treatment. Second, the optimal timing for surgical intervention remains unclear. Cohort Studies and Predictive Clinical Models Different authors tried to identify which (early) parameters are predictive for severe NEC. Christensen et al54 identified bloody stools (32%), increased abdominal girth (66%) and elevated prefeeding gastric residuals or emesis (48%) as the most frequent specific antecedents for presence of severe NEC (grade III). In another study from the same group, a rise in CRP, immature to total neutrophils and mean platelet volume, a low pH value, antecedent blood transfusion, and first feeding not being colostrum were identified as factors related to the severity of NEC.55 Moss et al investigated which clinical factors were related to progression to severe NEC, requiring surgical intervention or leading to death. They found that 12 factors were related to progressive NEC (Table 2). However, it was not possible to develop a proper clinical model to predict progression of NEC.57 Table 2. Diagnostic Models of Surgical NEC Open in new tab Table 2. Diagnostic Models of Surgical NEC Open in new tab To optimize the timing for surgical intervention, Tepas et al developed a scoring system incorporating 7 items: metabolic acidosis (pH < 7.25), severe thrombocytopenia (<50 × 109/L), hypotension requiring volume expansion or drug therapy, hyponatremia <130 mmol/L, neutropenia, left shift of neutrophils (I/T ratio <0.2), and positive blood culture. In a retrospective study, a medical center with surgical intervention based on a score ≥3 was compared with a control center which did not use this system. The usage of this scoring system showed better outcomes.56 However, this scoring system should always be used together with clinical evaluation and serial radiography. More recently, Ji et al59 used clinical and laboratory parameters at the time of diagnosis to develop a data driven algorithm, which can automatically classify NEC Bell's stage and predict the risk of progression NEC to the need of surgical intervention (http://translationalmedicine.stanford.edu/cgi-bin/NEC/index.pl). The variables which contributed most in the model are summarized in Table 2. Although the groups with low and high risk of disease progression could be identified with high confidence, the investigators still experienced problems with prognostication of the intermediate risk group.59 It was postulated that novel biomarkers may help with predicting the prognosis of NEC. Indeed, in a previously published study, a similar algorithm placed 40% of the infants with NEC in the intermediate risk group in whom disease progression could not be predicted accurately. Implementation of urine peptide biomarkers (fibrinogen peptides: FGA1826, FGA1883, and FGA2659) dramatically improved the ability of the algorithm to predict progression of disease.58 Radiologic Models of NEC Recently, the Dukes Abdominal Assessment Scale was developed, which uses a 10-point radiographic scoring scale for NEC. Zero points stands for “normal gas pattern” and 5 points stands for “fixed or persistent dilated bowel loops.” A score of 10 is indicative for “pneumoperitoneum.” A recent evaluation of this score demonstrated that an increasing Dukes Abdominal Assessment Scale score is related to increased disease severity and need for surgical intervention.39 Biomarkers in NEC Early diagnosis of NEC and especially differentiation from neonatal sepsis is a major challenge (Table 3). Despite extensive research, no reliable (early) biomarker is currently available. Some specific properties are essential to be an ideal candidate biomarker in the detection of NEC. This biomarker should be unresponsive to sepsis, and should substantially increase in concentration in, e.g., blood, urine, or stools at the onset of NEC. Its level magnitude of increase should be proportional to the severity of intestinal tissue injury.63 Biomarkers can be divided in different categories. Nonspecific biomarkers, which are mostly biomarkers of inflammation and specific biomarkers, are biomarkers for gastrointestinal mucosal injury or NEC.65 Nonspecific biomarkers are not able to differentiate between sepsis, NEC, and other causes of (intestinal) inflammation. Table 3. Accuracy of Diagnostic Tests Used in NEC Open in new tab Table 3. Accuracy of Diagnostic Tests Used in NEC Open in new tab Nonspecific Biomarkers The most commonly used nonspecific biomarker is CRP. CRP levels may increase 12 to 24 hours after onset of inflammation, the specificity is low, and differentiation with sepsis is not possible.66,67 Another nonspecific biomarker is serum amyloid A (SAA). Serum-levels of SAA can increase up to 1000-fold in the 8 to 24 hours after the onset of inflammation. It can be used in the diagnosis and follow-up of NEC with a similar accuracy as CRP, as there is also a mild correlation with the height of SAA and the severity of NEC.67 Recently, the measurement of ApoSAA has been investigated. It consists of plasma levels of SAA combined with apolipoprotein CII (apoC2). This combination of biomarkers is able to identify all NEC and sepsis cases at the onset of diagnosis. Furthermore, it enables risk stratification of sepsis/NEC children, thereby aiding in the decision-making process regarding early cessation and withholding of antibiotic treatment. However, distinction between NEC and sepsis was not possible.68,69 In another study, urinary SAA levels in neonates with NEC were investigated. Urinary SAA levels were significant higher in neonates with NEC, and SAA levels could distinguish between medical and surgical NEC.61,69 The addition of another biomarker did not improve the accuracy of urinary SAA. However, the addition of a clinical parameter (thrombocytes) did improve accuracy in predicting surgical NEC.61 Other nonspecific biomarkers are procalcitonin,67 arginine,70 platelet-activating factor,71 and S100A8/A9.72 All these biomarkers have been studied in small studies, and their role in the diagnosis of NEC has yet to be confirmed by larger multicenter trials. Besides proteins, cytokines, e.g., interleukin-673 and chemokines, e.g., interleukin-874 are considered early biomarkers for diagnosing neonatal sepsis and NEC, the combination of early- and late-warning biomarkers can detect these conditions in almost all cases within 48 hours of disease onset.65 Proinflammatory cytokines are essential for adequate immune response by the influx of activated leukocytes to sites of inflammation, but excessive influx of potent proinflammatory mediators adhered to the leukocytes can in contrast lead to widespread damage and cell death. Anti-inflammatory cytokines, e.g., interleukin-10, can downregulate the release and effect of proinflammatory mediators. Therefore, both proinflammatory and anti-inflammatory cytokines are elevated in the context of sepsis and NEC. The combination of anti-inflammatory cytokines in a proinflammatory to anti-inflammatory cytokine ratio may reflect severity of illness and accurately predict complications of these diseases.73,75 Specific Biomarkers Feces contain valuable information regarding the presence of gastrointestinal diseases and associated microbiotal profiles; however, usage of feces for diagnostic properties has some limitations. In NEC, the intestinal mucosal permeability is increased; therefore, proteins are secreted into the fecal stream.65 These proteins are not equally secreted from the gastrointestinal mucosa into the feces, and different protein concentrations were found in 1 fecal sample.65 Furthermore, feces are not always easily obtained, especially in NEC where constipation is common.74 One of the secreted proteins present in stools is calprotectin, being a calcium- and zinc-binding protein. For 60%, it consists of soluble cytosol proteins from human neutrophil granulocyte. It is resilient to bacterial degradation and has been proposed as a useful biomarker in adults and children with inflammatory bowel disease.76 In studies on NEC, many calprotectin values were outside the normal reference rates for adults.77 However, there is also a wide variation in calprotectin levels in healthy neonates (1.0–625.1 μg/g) as there is for neonates with NEC (107.6–847.6 μg).61,78,79 Moreover, differences have been found depending on gestational and postnatal age.78 The wide variation and overlap between healthy neonates and NEC, and the differences between studies, limits the use of this biomarker in daily practice.65 Another fecal biomarker is S100A12 (calgranulin C), which belongs to a novel group of proinflammatory molecules playing an important role in the innate immunity.62 In small-scaled studies, its role has been evaluated in NEC. Although the values of S100A12 are significantly higher in neonates with NEC compared with healthy neonates, it has similar disadvantages as calprotectin: wide variation and high interindividual and intraindividual variability and significant differences depending on gestational age.62 Like calprotectin, its use as a predictive biomarker in NEC is currently limited. Because differentiation from sepsis is the biggest challenge, recent research has focused on gut-/NEC-specific biomarkers. Two of these are intestinal fatty acid binding protein (I-FABP) and liver-fatty acid binding protein (L-FABP). These proteins are solely synthesized by enterocytes (I-FABP) or only by enterocytes and hepatocytes (L-FABP).1 Another protein is trefoil factor 3, which is predominantly expressed in the intestinal goblet cells and mucin-producing epithelial cells.80 These plasma proteins are significantly higher in patients with NEC than in patients with septicemia. Also, these biomarkers can discriminate between surgical and nonsurgical NEC (sensitivity, 67%–75%; specificity, 75%–88%).63 To investigate if the combination of these markers can increase the diagnostic sensitivity and specificity, the LIT score (L-FABP, I-FABP, TTF3) was formulated, with a scale of 0 to 9. This score improved the sensitivity and specificity to 83% and 100%, respectively, for identifying surgical NEC cases.63 These gut-specific biomarkers can aid neonatologists in the diagnostic and therapeutic workup of NEC, especially in surgical NEC. These markers have also been studied in urine samples, where they provide the same diagnostic abilities.81 In urine, with the aid of liquid chromatography-mass spectrometry, 3 more biomarkers have been identified and validated (fibrinogen peptides: FGA1826, FGA1883, and FGA2659) and successfully discriminated surgical NEC from nonsurgical NEC.58 Since liquid chromatography-mass spectrometry has no place in clinical practice because of time-consuming analysis and high costs, there is currently no role for these markers in routine clinical practice. A follow-up study of the same cohort also using urinary liquid chromatography-mass spectrometry revealed 7 candidate biomarkers. When they were used in panels, they had strong diagnostic capacities, (NEC versus sepsis: sensitivity 89%, specificity 80%, medical NEC versus surgical NEC: sensitivity 89%, specificity 90%).82 In a pilot study, the role of fecal volatile organic compounds (VOCs) in NEC has been studied. VOCs are volatile carbon based-molecules resulting from biochemical processes in the body and are emitted from feces, urine, and other body fluids. VOC analysis was performed by means of solid-phase microextraction and gas chromatography and mass spectrometry. In this small-scaled study (6 NEC cases versus 7 controls), decreased total number next to specific differences in VOC composition was observed in the 4 days before onset of disease, therefore possibly serving as an early diagnostic marker.83 However, gas chromatography and mass spectrometry is an expensive and time-consuming technique, limiting its widespread use in clinical practice. Therefore, prospective studies on VOC analysis as noninvasive biomarker for NEC, using high-throughput techniques, like electronic nose devices, are awaited. Other potential biomarkers could be markers of oxidative stress in the umbilical cord84 or from genetic origin.85 Analysis of fecal samples on microbiota face the limits at present as most biomarkers described above. This is not feasible in routine care as the determination of different patterns requires sophisticated analyses and are time consuming. Furthermore, as detailed out before, the prognostic value of bacterial species distribution next to the quantification of different strains are still unclear and require more research. Conclusions and Future Perspectives Diagnosis and course of NEC remain largely unpredictable based on the presently available clinical, biological, and radiological markers. Current diagnostic tools use signs of already established or progressive disease. As early diagnosis is critical for therapy and outcome, more accurate predictive biomarkers of NEC are needed. Future research should focus on the biological and microbiotal processes underlying the development of NEC. There is a clear rationale to explore the usage of biomarkers based on the altered microbiotal profile in NEC. Measurement of VOCs emanating from feces may serve as such a rapid, noninvasive, low-cost, and easy to use specific biomarker. A predictive model based on different (bio)markers may lead to even better diagnostic possibilities, tailored probiotic-based feeding strategies as well as therapeutic interventions. As NEC remains to have an unacceptable high mortality and morbidity rate, we should proceed with the challenging search for better diagnostic and therapeutic strategies. References 1. Dominguez KM , Moss RL . Necrotizing enterocolitis . Clin Perinatol . 2012 ; 39 : 387 – 401 . Google Scholar Crossref Search ADS PubMed WorldCat 2. Yee WH , Soraisham AS , Shah VS , et al. . Incidence and timing of presentation of necrotizing enterocolitis in preterm infants . Pediatrics . 2012 ; 129 : e298 – e304 . Google Scholar Crossref Search ADS PubMed WorldCat 3. Neu J , Walker WA . Necrotizing enterocolitis . N Engl J Med . 2011 ; 364 : 255 – 264 . Google Scholar Crossref Search ADS PubMed WorldCat 4. Crissinger KD . Regulation of hemodynamics and oxygenation in developing intestine: insight into the pathogenesis of necrotizing enterocolitis . Acta Paediatr Suppl . 1994 ; 396 : 8 – 10 . Google Scholar Crossref Search ADS PubMed WorldCat 5. Been JV , Lievense S , Zimmermann LJ , et al. . Chorioamnionitis as a risk factor for necrotizing enterocolitis: a systematic review and meta-analysis . J Pediatr . 2013 ; 162 : 236 – 242 .e2. Google Scholar Crossref Search ADS PubMed WorldCat 6. Schaart MW , de Bruijn AC , Bouwman DM , et al. . Epithelial functions of the residual bowel after surgery for necrotising enterocolitis in human infants . J Pediatr Gastroenterol Nutr . 2009 ; 49 : 31 – 41 . Google Scholar Crossref Search ADS PubMed WorldCat 7. Thompson AM , Bizzarro MJ . Necrotizing enterocolitis in newborns: pathogenesis, prevention and management . Drugs . 2008 ; 68 : 1227 – 1238 . Google Scholar Crossref Search ADS PubMed WorldCat 8. Wu SF , Caplan M , Lin HC . Necrotizing enterocolitis: old problem with new hope . Pediatr Neonatol . 2012 ; 53 : 158 – 163 . Google Scholar Crossref Search ADS PubMed WorldCat 9. Lucas A , Cole TJ . Breast milk and neonatal necrotising enterocolitis . Lancet . 1990 ; 336 : 1519 – 1523 . Google Scholar Crossref Search ADS PubMed WorldCat 10. Torrazza RM , Neu J . The altered gut microbiome and necrotizing enterocolitis . Clin Perinatol . 2013 ; 40 : 93 – 108 . Google Scholar Crossref Search ADS PubMed WorldCat 11. Ahle M , Drott P , Andersson RE . Epidemiology and trends of necrotizing enterocolitis in Sweden: 1987–2009 . Pediatrics . 2013 ; 132 : e443 – e451 . Google Scholar Crossref Search ADS PubMed WorldCat 12. Snyder CL , Hall M , Sharma V , et al. . Seasonal variation in the incidence of necrotizing enterocolitis . Pediatr Surg Int . 2010 ; 26 : 895 – 898 . Google Scholar Crossref Search ADS PubMed WorldCat 13. Jilling T , Simon D , Lu J , et al. . The roles of bacteria and TLR4 in rat and murine models of necrotizing enterocolitis . J Immunol . 2006 ; 177 : 3273 – 3282 . Google Scholar Crossref Search ADS PubMed WorldCat 14. Cilieborg MS , Thymann T , Siggers R , et al. . The incidence of necrotizing enterocolitis is increased following probiotic administration to preterm pigs . J Nutr . 2011 ; 141 : 223 – 230 . Google Scholar Crossref Search ADS PubMed WorldCat 15. Santulli TV , Schullinger JN , Heird WC , et al. . Acute necrotizing enterocolitis in infancy: a review of 64 cases . Pediatrics . 1975 ; 55 : 376 – 387 . Google Scholar PubMed WorldCat 16. Alfa MJ , Robson D , Davi M , et al. . An outbreak of necrotizing enterocolitis associated with a novel clostridium species in a neonatal intensive care unit . Clin Infect Dis . 2002 ; 35 : S101 – S105 . Google Scholar Crossref Search ADS PubMed WorldCat 17. Gothefors L , Blenkharn I . Clostridium butyricum and necrotising enterocolitis . Lancet . 1978 ; 1 : 52 – 53 . Google Scholar Crossref Search ADS PubMed WorldCat 18. Kosloske AM , Ball WS Jr , Umland E , et al. . Clostridial necrotizing enterocolitis . J Pediatr Surg . 1985 ; 20 : 155 – 159 . Google Scholar Crossref Search ADS PubMed WorldCat 19. Kosloske AM , Ulrich JA , Hoffman H . Fulminant necrotising enterocolitis associated with Clostridia . Lancet . 1978 ; 2 : 1014 – 1016 . Google Scholar Crossref Search ADS PubMed WorldCat 20. de la Cochetiere MF , Piloquet H , des Robert C , et al. . Early intestinal bacterial colonization and necrotizing enterocolitis in premature infants: the putative role of Clostridium . Pediatr Res . 2004 ; 56 : 366 – 370 . Google Scholar Crossref Search ADS PubMed WorldCat 21. Mai V , Young CM , Ukhanova M , et al. . Fecal microbiota in premature infants prior to necrotizing enterocolitis . PLoS One. 2011 ; 6 : e20647 . Google Scholar Crossref Search ADS PubMed WorldCat 22. Morrow AL , Lagomarcino AJ , Schibler KR , et al. . Early microbial and metabolomic signatures predict later onset of necrotizing enterocolitis in preterm infants . Microbiome. 2013 ; 1 : 13 . Google Scholar Crossref Search ADS PubMed WorldCat 23. Stewart CJ , Marrs EC , Magorrian S , et al. . The preterm gut microbiota: changes associated with necrotizing enterocolitis and infection . Acta Paediatr . 2012 ; 101 : 1121 – 1127 . Google Scholar Crossref Search ADS PubMed WorldCat 24. Stewart CJ , Marrs EC , Nelson A , et al. . Development of the preterm gut microbiome in twins at risk of necrotising enterocolitis and sepsis . PLoS One. 2013 ; 8 : e73465 . Google Scholar Crossref Search ADS PubMed WorldCat 25. Wang Y , Hoenig JD , Malin KJ , et al. . 16S rRNA gene-based analysis of fecal microbiota from preterm infants with and without necrotizing enterocolitis . ISME J . 2009 ; 3 : 944 – 954 . Google Scholar Crossref Search ADS PubMed WorldCat 26. LaTuga MS , Ellis JC , Cotton CM , et al. . Beyond bacteria: a study of the enteric microbial consortium in extremely low birth weight infants . PLoS One. 2011 ; 6 : e27858 . Google Scholar Crossref Search ADS PubMed WorldCat 27. Mshvildadze M , Neu J , Shuster J , et al. . Intestinal microbial ecology in premature infants assessed with non-culture-based techniques . J Pediatr . 2010 ; 156 : 20 – 25 . Google Scholar Crossref Search ADS PubMed WorldCat 28. Normann E , Fahlen A , Engstrand L , et al. . Intestinal microbial profiles in extremely preterm infants with and without necrotizing enterocolitis . Acta Paediatr . 2013 ; 102 : 129 – 136 . Google Scholar Crossref Search ADS PubMed WorldCat 29. Sharma R , Hudak ML , Tepas JJ III , et al. . Impact of gestational age on the clinical presentation and surgical outcome of necrotizing enterocolitis . J Perinatol . 2006 ; 26 : 342 – 347 . Google Scholar Crossref Search ADS PubMed WorldCat 30. Kosloske AM . Indications for operation in necrotizing enterocolitis revisited . J Pediatr Surg . 1994 ; 29 : 663 – 666 . Google Scholar Crossref Search ADS PubMed WorldCat 31. Kanto WP Jr , Hunter JE , Stoll BJ . Recognition and medical management of necrotizing enterocolitis . Clin Perinatol . 1994 ; 21 : 335 – 346 . Google Scholar PubMed WorldCat 32. Kenton AB , O'Donovan D , Cass DL , et al. . Severe thrombocytopenia predicts outcome in neonates with necrotizing enterocolitis . J Perinatol . 2005 ; 25 : 14 – 20 . Google Scholar Crossref Search ADS PubMed WorldCat 33. Song R , Subbarao GC , Maheshwari A . Haematological abnormalities in neonatal necrotizing enterocolitis. J Matern Fetal Neonatal Med. 2012 ; 25 (suppl 4):22–25. WorldCat 34. Bizzarro MJ , Ehrenkranz RA , Gallagher PG . Concurrent bloodstream infections in infants with necrotizing enterocolitis . J Pediatr . 2014 ; 164 : 61 – 66 . Google Scholar Crossref Search ADS PubMed WorldCat 35. Epelman M , Daneman A , Navarro OM , et al. . Necrotizing enterocolitis: review of state-of-the-art imaging findings with pathologic correlation . Radiographics . 2007 ; 27 : 285 – 305 . Google Scholar Crossref Search ADS PubMed WorldCat 36. Lin PW , Stoll BJ . Necrotising enterocolitis . Lancet . 2006 ; 368 : 1271 – 1283 . Google Scholar Crossref Search ADS PubMed WorldCat 37. Buonomo C . The radiology of necrotizing enterocolitis. Radiol Clin North Am. 1999 ; 37 : 1187 – 1198 , vii. Google Scholar Crossref Search ADS PubMed WorldCat 38. Muchantef K , Epelman M , Darge K , et al. . Sonographic and radiographic imaging features of the neonate with necrotizing enterocolitis: correlating findings with outcomes . Pediatr Radiol . 2013 ; 43 : 1444 – 1452 . Google Scholar Crossref Search ADS PubMed WorldCat 39. Coursey CA , Hollingsworth CL , Wriston C , et al. . Radiographic predictors of disease severity in neonates and infants with necrotizing enterocolitis . AJR Am J Roentgenol . 2009 ; 193 : 1408 – 1413 . Google Scholar Crossref Search ADS PubMed WorldCat 40. Sharma R , Tepas JJ III , Hudak ML , et al. . Portal venous gas and surgical outcome of neonatal necrotizing enterocolitis . J Pediatr Surg . 2005 ; 40 : 371 – 376 . Google Scholar Crossref Search ADS PubMed WorldCat 41. Hall NJ , Eaton S , Pierro A . Royal Australasia of Surgeons Guest Lecture. Necrotizing enterocolitis: prevention, treatment, and outcome . J Pediatr Surg . 2013 ; 48 : 2359 – 2367 . Google Scholar Crossref Search ADS PubMed WorldCat 42. Morrison SC , Jacobson JM . The radiology of necrotizing enterocolitis . Clin Perinatol . 1994 ; 21 : 347 – 363 . Google Scholar PubMed WorldCat 43. Sharma R , Hudak ML . A clinical perspective of necrotizing enterocolitis: past, present, and future . Clin Perinatol . 2013 ; 40 : 27 – 51 . Google Scholar Crossref Search ADS PubMed WorldCat 44. Faingold R , Daneman A , Tomlinson G , et al. . Necrotizing enterocolitis: assessment of bowel viability with color doppler US . Radiology . 2005 ; 235 : 587 – 594 . Google Scholar Crossref Search ADS PubMed WorldCat 45. Walsh MC , Kliegman RM . Necrotizing enterocolitis: treatment based on staging criteria . Pediatr Clin North Am . 1986 ; 33 : 179 – 201 . Google Scholar Crossref Search ADS PubMed WorldCat 46. Reisinger KW , Derikx JP , Thuijls G , et al. . Noninvasive measurement of intestinal epithelial damage at time of refeeding can predict clinical outcome after necrotizing enterocolitis . Pediatr Res . 2013 ; 73 : 209 – 213 . Google Scholar Crossref Search ADS PubMed WorldCat 47. Pourcyrous M , Korones SB , Yang W , et al. . C-reactive protein in the diagnosis, management, and prognosis of neonatal necrotizing enterocolitis . Pediatrics . 2005 ; 116 : 1064 – 1069 . Google Scholar Crossref Search ADS PubMed WorldCat 48. Raval MV , Moss RL . Current concepts in the surgical approach to necrotizing enterocolitis . Pathophysiology . 2014 ; 21 : 105 – 110 . Google Scholar Crossref Search ADS PubMed WorldCat 49. Moss RL , Dimmitt RA , Barnhart DC , et al. . Laparotomy versus peritoneal drainage for necrotizing enterocolitis and perforation . N Engl J Med . 2006 ; 354 : 2225 – 2234 . Google Scholar Crossref Search ADS PubMed WorldCat 50. Rees CM , Eaton S , Kiely EM , et al. . Peritoneal drainage or laparotomy for neonatal bowel perforation? A randomized controlled trial . Ann Surg . 2008 ; 248 : 44 – 51 . Google Scholar Crossref Search ADS PubMed WorldCat 51. Rao SC , Basani L , Simmer K , et al. . Peritoneal drainage versus laparotomy as initial surgical treatment for perforated necrotizing enterocolitis or spontaneous intestinal perforation in preterm low birth weight infants . Cochrane Database Syst Rev. 2011 ; 15 :CD006182. WorldCat 52. Pierro A , Eaton S , Rees CM , et al. . Is there a benefit of peritoneal drainage for necrotizing enterocolitis in newborn infants? J Pediatr Surg. 2010 ; 45 : 2117 – 2118 . Google Scholar Crossref Search ADS PubMed WorldCat 53. Hall NJ , Curry J , Drake DP , et al. . Resection and primary anastomosis is a valid surgical option for infants with necrotizing enterocolitis who weigh less than 1000 g . Arch Surg . 2005 ; 140 : 1149 – 1151 . Google Scholar Crossref Search ADS PubMed WorldCat 54. Christensen RD , Wiedmeier SE , Baer VL , et al. . Antecedents of Bell stage III necrotizing enterocolitis . J Perinatol . 2010 ; 30 : 54 – 57 . Google Scholar Crossref Search ADS PubMed WorldCat 55. Miner CA , Fullmer S , Eggett DL , et al. . Factors affecting the severity of necrotizing enterocolitis . J Matern Fetal Neonatal Med . 2013 ; 26 : 1715 – 1719 . Google Scholar Crossref Search ADS PubMed WorldCat 56. Tepas JJ III , Sharma R , Leaphart CL , et al. . Timing of surgical intervention in necrotizing enterocolitis can be determined by trajectory of metabolic derangement . J Pediatr Surg. 2010 ; 45 : 310 – 313 ; discussion 3–4. Google Scholar Crossref Search ADS PubMed WorldCat 57. Moss RL , Kalish LA , Duggan C , et al. . Clinical parameters do not adequately predict outcome in necrotizing enterocolitis: a multi-institutional study . J Perinatol . 2008 ; 28 : 665 – 674 . Google Scholar Crossref Search ADS PubMed WorldCat 58. Sylvester KG , Ling XB , Liu GY , et al. . A novel urine peptide biomarker-based algorithm for the prognosis of necrotising enterocolitis in human infants . Gut . 2014 ; 63 : 1284 – 1292 . Google Scholar Crossref Search ADS PubMed WorldCat 59. Ji J , Ling XB , Zhao Y , et al. . A data-driven algorithm integrating clinical and laboratory features for the diagnosis and prognosis of necrotizing enterocolitis . PLoS One. 2014 ; 9 : e89860 . Google Scholar Crossref Search ADS PubMed WorldCat 60. Yakut I , Tayman C , Oztekin O , et al. . Ischemia-modified Albumin may be a novel marker for the diagnosis and follow-up of necrotizing enterocolitis . J Clin Lab Anal . 2014 ; 28 : 170 – 177 . Google Scholar Crossref Search ADS PubMed WorldCat 61. Reisinger KW , Van der Zee DC , Brouwers HA , et al. . Noninvasive measurement of fecal calprotectin and serum amyloid A combined with intestinal fatty acid-binding protein in necrotizing enterocolitis . J Pediatr Surg . 2012 ; 47 : 1640 – 1645 . Google Scholar Crossref Search ADS PubMed WorldCat 62. Dabritz J , Jenke A , Wirth S , et al. . Fecal phagocyte-specific S100A12 for diagnosing necrotizing enterocolitis . J Pediatr . 2012 ; 161 : 1059 – 1064 . Google Scholar Crossref Search ADS PubMed WorldCat 63. Ng EW , Poon TC , Lam HS , et al. . Gut-associated biomarkers L-FABP, I-FABP, and TFF3 and LIT score for diagnosis of surgical necrotizing enterocolitis in preterm infants . Ann Surg . 2013 ; 258 : 1111 – 1118 . Google Scholar Crossref Search ADS PubMed WorldCat 64. Benkoe T , Reck C , Gleiss A , et al. . Interleukin 8 correlates with intestinal involvement in surgically treated infants with necrotizing enterocolitis . J Pediatr Surg . 2012 ; 47 : 1548 – 1554 . Google Scholar Crossref Search ADS PubMed WorldCat 65. Ng PC . Biomarkers of necrotising enterocolitis . Semin Fetal Neonatal Med . 2014 ; 19 : 33 – 38 . Google Scholar Crossref Search ADS PubMed WorldCat 66. Arnon S , Litmanovitz I . Diagnostic tests in neonatal sepsis . Curr Opin Infect Dis . 2008 ; 21 : 223 – 227 . Google Scholar Crossref Search ADS PubMed WorldCat 67. Cetinkaya M , Ozkan H , Koksal N , et al. . Comparison of the efficacy of serum amyloid A, C-reactive protein, and procalcitonin in the diagnosis and follow-up of necrotizing enterocolitis in premature infants . J Pediatr Surg . 2011 ; 46 : 1482 – 1489 . Google Scholar Crossref Search ADS PubMed WorldCat 68. Ng PC , Ang IL , Chiu RW , et al. . Host-response biomarkers for diagnosis of late-onset septicemia and necrotizing enterocolitis in preterm infants . J Clin Invest . 2010 ; 120 : 2989 – 3000 . Google Scholar Crossref Search ADS PubMed WorldCat 69. Reisinger KW , Kramer BW , Van der Zee DC , et al. . Non-invasive serum amyloid A (SAA) measurement and plasma platelets for accurate prediction of surgical intervention in severe necrotizing enterocolitis (NEC) . PLoS One. 2014 ; 9 : e90834 . Google Scholar Crossref Search ADS PubMed WorldCat 70. Richir MC , Siroen MP , van Elburg RM , et al. . Low plasma concentrations of arginine and asymmetric dimethylarginine in premature infants with necrotizing enterocolitis . Br J Nutr . 2007 ; 97 : 906 – 911 . Google Scholar Crossref Search ADS PubMed WorldCat 71. Rabinowitz SS , Dzakpasu P , Piecuch S , et al. . Platelet-activating factor in infants at risk for necrotizing enterocolitis . J Pediatr . 2001 ; 138 : 81 – 86 . Google Scholar Crossref Search ADS PubMed WorldCat 72. Terrin G , Passariello A , De Curtis M , et al. . S100 A8/A9 protein as a marker for early diagnosis of necrotising enterocolitis in neonates . Arch Dis Child. 2012 ; 97 : 1102 . Google Scholar Crossref Search ADS PubMed WorldCat 73. Ng PC , Li K , Wong RP , et al. . Proinflammatory and anti-inflammatory cytokine responses in preterm infants with systemic infections . Arch Dis Child Fetal Neonatal Ed . 2003 ; 88 : F209 – F213 . Google Scholar Crossref Search ADS PubMed WorldCat 74. Thuijls G , Derikx JP , van Wijck K , et al. . Non-invasive markers for early diagnosis and determination of the severity of necrotizing enterocolitis . Ann Surg . 2010 ; 251 : 1174 – 1180 . Google Scholar Crossref Search ADS PubMed WorldCat 75. Ng PC , Li K , Leung TF , et al. . Early prediction of sepsis-induced disseminated intravascular coagulation with interleukin-10, interleukin-6, and RANTES in preterm infants . Clin Chem . 2006 ; 52 : 1181 – 1189 . Google Scholar Crossref Search ADS PubMed WorldCat 76. Fagerhol MK . Calprotectin, a faecal marker of organic gastrointestinal abnormality . Lancet . 2000 ; 356 : 1783 – 1784 . Google Scholar Crossref Search ADS PubMed WorldCat 77. Tibble J , Teahon K , Thjodleifsson B , et al. . A simple method for assessing intestinal inflammation in Crohn's disease . Gut . 2000 ; 47 : 506 – 513 . Google Scholar Crossref Search ADS PubMed WorldCat 78. Carroll D , Corfield A , Spicer R , et al. . Faecal calprotectin concentrations and diagnosis of necrotising enterocolitis . Lancet . 2003 ; 361 : 310 – 311 . Google Scholar Crossref Search ADS PubMed WorldCat 79. Selimoglu MA , Temel I , Yildirim C , et al. . The role of fecal calprotectin and lactoferrin in the diagnosis of necrotizing enterocolitis . Pediatr Crit Care Med . 2012 ; 13 : 452 – 454 . Google Scholar Crossref Search ADS PubMed WorldCat 80. Hoffmann W , Jagla W , Wiede A . Molecular medicine of TFF-peptides: from gut to brain . Histol Histopathol . 2001 ; 16 : 319 – 334 . Google Scholar PubMed WorldCat 81. Evennett NJ , Hall NJ , Pierro A , et al. . Urinary intestinal fatty acid-binding protein concentration predicts extent of disease in necrotizing enterocolitis . J Pediatr Surg . 2010 ; 45 : 735 – 740 . Google Scholar Crossref Search ADS PubMed WorldCat 82. Sylvester KG , Ling XB , Liu GY , et al. . Urine protein biomarkers for the diagnosis and prognosis of necrotizing enterocolitis in infants . J Pediatr . 2014 ; 164 : 607 – 612 .e7. Google Scholar Crossref Search ADS PubMed WorldCat 83. Garner CE , Ewer AK , Elasouad K , et al. . Analysis of faecal volatile organic compounds in preterm infants who develop necrotising enterocolitis: a pilot study . J Pediatr Gastroenterol Nutr . 2009 ; 49 : 559 – 565 . Google Scholar Crossref Search ADS PubMed WorldCat 84. Perrone S , Tataranno ML , Negro S , et al. . May oxidative stress biomarkers in cord blood predict the occurrence of necrotizing enterocolitis in preterm infants? J Matern Fetal Neonatal Med. 2012 ; 25 (suppl 1):128–131. WorldCat 85. Sampath V , Le M , Lane L , et al. . The NFKB1 (g.-24519delATTG) variant is associated with necrotizing enterocolitis (NEC) in premature infants . J Surg Res . 2011 ; 169 : e51 – e57 . Google Scholar Crossref Search ADS PubMed WorldCat Author notes Reprints: Nanne K. H. de Boer, MD, PhD, Department of Gastroenterology and Hepatology, VU University Medical Center, PO Box 7057, Amsterdam 1007 MB, the Netherlands (e-mail: khn.deboer@vumc.nl). The authors have no conflicts of interest to disclose. Copyright © 2014 Crohn's & Colitis Foundation of America, Inc.
TI - Necrotizing Enterocolitis: A Clinical Review on Diagnostic Biomarkers and the Role of the Intestinal Microbiota
JF - Inflammatory Bowel Diseases
DO - 10.1097/MIB.0000000000000184
DA - 2015-02-01
UR - https://www.deepdyve.com/lp/oxford-university-press/necrotizing-enterocolitis-a-clinical-review-on-diagnostic-biomarkers-oTYM8PQvFq
SP - 436
VL - 21
IS - 2
DP - DeepDyve
ER -