Fecal calprotectin concentrations in premature infants have a lower limit and show postnatal and gestational age dependence

Uncovering the gastrointestinal passage, intestinal epithelial cellular uptake and AGO2 loading of milk miRNAs in neonates using xenomiRs as tracers

BACKGROUND

Human breast milk has a high microRNA (miRNA) content. It remains unknown whether and how milk miRNAs might affect intestinal gene regulation and homeostasis of the developing microbiome after initiation of enteral nutrition. However, this requires that relevant milk miRNA amounts survive gastrointestinal passage, are taken up by cells, and become available to the RNA interference (RNAi) machinery. It seems important to dissect the fate of these miRNAs after oral ingestion and gastrointestinal passage.

OBJECTIVE

Our goal was to analyze the potential transmissibility of milk miRNAs via the gastrointestinal system in neonate humans and a porcine model in vivo to contribute to the discussion whether milk miRNAs could influence gene regulation in neonates and thus might vertically transmit developmental relevant signals.

DESIGN

We performed cross-species profiling of miRNAs via deep-sequencing and utilized dietary xenobiotic taxon-specific milk miRNA (xenomiRs) as tracers in human and porcine neonates, followed by functional studies in primary human fetal intestinal epithelial cells (HIEC-6) using Ad5-mediated miRNA-gene transfer.

RESULTS

Mammals share many milk miRNAs yet exhibit taxon-specific miRNA fingerprints. We traced bovine-specific miRNAs from formula-nutrition in human preterm stool and 9 days after onset of enteral feeding in intestinal cells of preterm piglets. Thereafter, several xenomiRs accumulated in the intestinal cells. Moreover, few hours after introducing enteral feeding in preterm piglets with supplemented reporter miRNAs (cel-miR-39-5p/-3p), we observed their enrichment in blood serum and in AGO2-immunocomplexes from intestinal biopsies.

CONCLUSIONS

Milk-derived miRNAs survived gastrointestinal passage in human and porcine neonates. Bovine-specific miRNAs accumulated in intestinal cells of preterm piglets after enteral feeding with bovine colostrum/formula. In piglets, colostrum supplementation with cel-miR-39-5p/-3p resulted in increased blood levels of cel-miR-39-3p and argonaute RISC catalytic component 2 (AGO2) loading in intestinal cells. This suggests the possibility of vertical transmission of miRNA signaling from milk through the neonatal digestive tract.

Influence of Perinatal Factors on Blood Tryptase and Fecal Calprotectin Levels in Newborns

BACKGROUND

Blood tryptase and fecal calprotectin levels may serve as biomarkers of necrotizing enterocolitis. However, their interpretation may be hindered by the little-known effects of perinatal factors. The aim of this study was to compare the tryptase and calprotectin levels in newborns according to their term, trophicity, and sex.

METHOD

One hundred and fifty-seven premature newborns and 157 full-term newborns were included. Blood tryptase and fecal calprotectin were assayed.

RESULTS

Blood tryptase levels were higher in premature than in full-term newborns (6.4 vs. 5.2 µg/L; p < 0.001). In situations of antenatal use of corticosteroids (p = 0.007) and non-exclusive use of human milk (p = 0.02), these levels were also higher. However, in multiple linear regression analyses, only prematurity significantly influenced tryptase levels. Fecal calprotectin levels were extremely wide-ranging and were much higher in female than in male newborns (300.5 vs. 110.5 µg/g; p < 0.001).

CONCLUSIONS

The differences in tryptase levels according to term could be linked to early aggression of the still-immature digestive wall in premature newborns, in particular, by enteral feeding started early. The unexpected influence of sex on fecal calprotectin levels remains unexplained.

Emerging prediction methods for early diagnosis of necrotizing enterocolitis

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

Making Research Flourish Through ESPGHAN: A Position Paper From the ESPGHAN Special Interest Group for Basic and Translational Research

ABSTRACT

Recent research breakthroughs have emerged from applied basic research throughout all scientific areas, including adult and paediatric gastroenterology, hepatology and nutrition (PGHAN). The research landscape within the European Society of Paediatric Gastroenterology and Nutrition (ESPGHAN) is also inevitably changing from clinical research to studies involving applied laboratory research. This position paper aims to depict the current status quo of basic science and translational research within ESPGHAN, and to delineate how the society could invest in research in the present and future time. The paper also explores which research areas in the field of PGHAN represent the current and future priorities, and what type of support is needed across the ESPGHAN working groups (WGs) and special interest groups (SIGs) to fulfil their research goals.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

IMPACT

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

Exploring Social and Demographic Factors as Determinants of Intestinal Inflammation in Very Low Birth-Weight Infants

BACKGROUND

Very low birth-weight (VLBW) infants are disproportionately affected by inflammatory morbidities including necrotizing enterocolitis. Despite the influence of social and demographic factors on infant health outcomes, their relationship with intestinal inflammation is unknown.

PURPOSE

To explore the influence of maternal race, maternal socioeconomic status, and infant sex on intestinal inflammation in VLBW infants.

METHODS

This was a secondary analysis of existing data from a randomized controlled trial of 143 infants 32 weeks' gestation or less and weighing 1250 g or less. In the previous study, fecal calprotectin and S100A12 values were collected at weeks 3 and 6. The infant sample was determined on the basis of the availability of these results, which served as intestinal inflammation biomarkers for the present study. General linear mixed models assessed the relationship between biomarkers and social and demographic factors. Gestational age, antibiotic exposure, mother's own milk feeding, acuity, and week of sample collection were used as control variables.

FINDINGS/RESULTS

The sample included 124 infants. Fifty-two infants (42%) were African American, 86 (69%) had Medicaid coverage, and 65 (53%) were male. Fecal calprotectin levels were higher in African American infants (P = .02) and infants with private insurance coverage (P = .009); no difference was found between sexes. There was no association between S100A12 levels and infant sex, maternal race, or socioeconomic status.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Consideration of social and demographic factors may be important when caring for VLBW infants. Further exploration of factors contributing to associations between social or demographic factors and intestinal inflammation is needed.

[Role of fecal calprotectin in the diagnosis of neonatal necrotizing enterocolitis: a Meta analysis]

OBJECTIVE

To study the value of fecal calprotectin (FC) in the diagnosis of neonatal necrotizing enterocolitis (NEC) through a Meta analysis.

METHODS

Web of Science, Cochrane Library, PubMed, Embase, China National Knowledge Infrastructure, Weipu Periodical Database, Wanfang Data, Chinese Biomedical Literature Database were searched for related studies published up to May 2020, with manual search as supplementation. The QUADAS criteria were used to evaluate the quality of the articles included. Meta-DiSc 1.4 and Stata 15.0 software were used to perform the Meta analysis, including the evaluation of specificity, sensitivity, likelihood ratio, and diagnostic odds ratio. The sensitivity analysis and heterogeneity testing were performed, and the summary receiver operating characteristic (SROC) curve and Fagan diagram were plotted.

RESULTS

A total of 15 articles were enrolled, involving 1 719 neonates. Among these articles, 4 had low quality, 2 had high quality, and the rest had medium quality. There was high heterogeneity between studies, and there was no threshold effect or publication bias. The random effects model analysis showed that FC had a pooled specificity of 0.80 (95%CI:0.78-0.82) and a sensitivity of 0.86 (95%CI:0.83-0.89) in the diagnosis of NEC, with a negative likelihood ratio of 0.19 (95%CI:0.14-0.26), a positive likelihood ratio of 4.71 (95%CI:3.57-6.23), and a diagnostic odds ratio of 29.56 (95%CI:17.98-48.61). The area under the SROC curve was 0.9131 and the Q^* index was 0.8456. The Fagan diagram showed that the post-test probability of NEC indicated by negative FC was 13%, while that indicated by positive FC was 86%. The Meta regression analysis showed that the heterogeneity came from other non-threshold factors.

CONCLUSIONS

FC has high potential and efficiency in the early diagnosis of NEC. FC measurement can be used for the diagnosis of NEC, but it should be combined with clinical manifestations and other related laboratory examinations.

The Use of Fecal Calprotectin Testing in Paediatric Disorders: A Position Paper of the European Society for Paediatric Gastroenterology and Nutrition Gastroenterology Committee

OBJECTIVES

The aim of the study was to review the evidence regarding the clinical use and value of fecal calprotectin (FC) measurements in different gastrointestinal disorders in children.

METHODS

A literature search was conducted in the PubMed, MEDLINE, EMBASE, and Cochrane databases until October 31, 2019. Subtopics were identified and each assigned to individual authors.

RESULTS

A total of 28 recommendations were voted on using the nominal voting technique. Recommendations are given related to sampling, measurement methods, and results interpretation. The 14 authors anonymously voted on each recommendation using a 9-point scale (1 strongly disagree to 9 fully agree). Consensus was considered achieved if at least 75% of the authors voted 6, 7, 8, or 9.

CONCLUSIONS

Consensus was reached for all recommendations. Limitations for the use of FC in clinical practice include variability in extraction methodology, performance of test kits as well as the need to establish local reference ranges because of the influence of individual factors, such as age, diet, microbiota, and drugs. The main utility of FC measurement at present is in the diagnosis and monitoring of inflammatory bowel disease (IBD) as well as to differentiate it from functional gastrointestinal disorders (FAPDs). FC, however, has neither utility in the diagnosis of infantile colic nor to differentiate between functional and organic constipation. A rise in FC concentration, may alert to the risk of developing necrotizing enterocolitis and help identifying gastrointestinal involvement in children with Henoch-Schönlein purpura. FC measurement is of little value in Cow's Milk Protein Allergy, coeliac disease (CD), and cystic fibrosis. FC does neither help to distinguish bacterial from viral acute gastroenteritis (AGE), nor to diagnose Helicobacter Pylori infection, small intestinal bacterial overgrowth (SIBO), acute appendicitis (AA), or intestinal polyps.

Correlation between Fecal Calprotectin Levels in Meconium and Vitamin D Levels in Cord Blood: Association with Intestinal Distress

We aimed to investigate the correlation between vitamin D status in cord blood and fecal calprotectin concentrations in meconium, and also find their association with intestinal distress symptoms during the first two weeks of life. Two hundred and twenty-eight newborns were enrolled in the study who were delivered at Kyungpook National University Children’s Hospital between July 2016 and August 2017. The first passed meconium samples were collected for fecal calprotectin analysis. Intestinal distress involved infants with necrotizing enterocolitis (NEC) and other feeding interruption signs. The median gestational age of the population was 37.0 (34.3–38.4) weeks, and the median birth weight was 2635 (2100–3268) g. The median fecal calprotectin levels in meconium were 134.1 (55.6–403.2) μg/g (range: 11.5–2000 μg/g) and the median 25-hydroxyvitamin D (25-OHD) concentrations in cord blood were 21.0 (15.5–28.8) ng/mL. Sixty infants (26.3%) had intestinal distress, including four patients (1.8%) diagnosed as having NEC. Higher fecal calprotectin concentrations (398.2 (131.8–900.2) μg/g vs. 105.6 (39.4–248.5) μg/g, p < 0.001) and lower 25-OHD levels (17.9 (12.8–22.1) ng/mL vs. 23.2 (17.2–33.0) ng/mL, p < 0.001) were found in infants with intestinal distress compared to infants without intestinal distress. The cut-off value was set at 359.8 μg/g with a sensitivity of 0.53 and a specificity of 0.82 for the development of intestinal distress in the first two weeks of life. Serum 25-OHD levels in cord blood were inversely correlated with fecal calprotectin concentrations in meconium.

Diagnostic value of fecal calprotectin in necrotizing enterocolitis: A meta-analysis

BACKGROUND AND OBJECTIVES

Necrotizing enterocolitis is a common gastrointestinal disease in newborns, especially in preterm infants. Our study analyzed the value of fecal calprotectin as a biomarker in the diagnosis of NEC based on previous studies that have confirmed elevated calprotectin levels in NEC patients.

METHOD

We searched several databases including PubMed, Medline, Web of Science and Cochrane Library to identify studies of humans investigating the performance characteristics of fecal calprotectin for the diagnosis of NEC. The quality of included studies was assessed by RevMan5 software (QUADAS-2). The sensitivity, specificity and other measurements of accuracy of fecal calprotectin were pooled using Meta-DiSc software.

RESULT

A total 10 studies with 568 patients included in our meta-analysis. The pooled sensitivity, specificity, diagnostic odds ratio (DOR) and AUC were: 0.86 (95%CI: 0.80-0.91), 0.79 (95%CI: 0.75-0.83), 34.78 (95% CI: 15.30 to 79.07) and 0.92. The pooled sensitivity, specificity, DOR and AUC of subgroup analysis were: 0.85 (95%CI: 0.79-0.90), 0.89 (95%CI: 0.85-0.92), 41.03 (95% CI: 16.87 to 99.78) and 0.92 for nine studies using ELISA; 0.85 (95%CI: 0.79-0.90), 0.89 (95%CI: 0.85-0.92), 42.08 (95% CI: 18.44 to 96.04) and 0.93 for six prospective studies; 0.91 (95%CI: 0.82-0.97), 0.93 (95%CI: 0.88-0.96), 69.51 (95% CI: 17.67 to 273.40) and 0.95 for four studies of preterm infants. 0.86 (95%CI: 0.77-0.92), 0.94 (95%CI: 0.90-0.97), 53.23 (95% CI: 15.68 to 180.73) and 0.94 five studies that defined NEC as stage II or above.

CONCLUSION

Fecal calprotectin is a promising biomarker with high diagnostic value in neonatal, especially in premature infants.

S100A8 and S100A9 Are Important for Postnatal Development of Gut Microbiota and Immune System in Mice and Infants

BACKGROUND & AIMS

After birth, the immune system matures via interactions with microbes in the gut. The S100 calcium binding proteins S100A8 and S100A9, and their extracellular complex form, S100A8-A9, are found in high amounts in human breast milk. We studied levels of S100A8-A9 in fecal samples (also called fecal calprotectin) from newborns and during infancy, and their effects on development of the intestinal microbiota and mucosal immune system.

METHODS

We collected stool samples (n = 517) from full-term (n = 72) and preterm infants (n = 49) at different timepoints over the first year of life (days 1, 3, 10, 30, 90, 180, and 360). We measured levels of S100A8-A9 by enzyme-linked immunosorbent assay and analyzed fecal microbiomes by 16S sRNA gene sequencing. We also obtained small and large intestine biopsies from 8 adults and 10 newborn infants without inflammatory bowel diseases (controls) and 8 infants with necrotizing enterocolitis and measured levels of S100A8 by immunofluorescence microscopy. Children were followed for 2.5 years and anthropometric data and medical information on infections were collected. We performed studies with newborn C57BL/6J wild-type and S100a9^-/- mice (which also lack S100A8). Some mice were fed or given intraperitoneal injections of S100A8 or subcutaneous injections of Staphylococcus aureus. Blood and intestine, mesenterial and celiac lymph nodes were collected; cells and cytokines were measured by flow cytometry and studied in cell culture assays. Colon contents from mice were analyzed by culture-based microbiology assays.

RESULTS

Loss of S100A8 and S100A9 in mice altered the phenotypes of colonic lamina propria macrophages, compared with wild-type mice. Intestinal tissues from neonatal S100-knockout mice had reduced levels of CX3CR1 protein, and Il10 and Tgfb1 mRNAs, compared with wild-type mice, and fewer T-regulatory cells. S100-knockout mice weighed 21% more than wild-type mice at age 8 weeks and a higher proportion developed fatal sepsis during the neonatal period. S100-knockout mice had alterations in their fecal microbiomes, with higher abundance of Enterobacteriaceae. Feeding mice S100 at birth prevented the expansion of Enterobacteriaceae, increased numbers of T-regulatory cells and levels of CX3CR1 protein and Il10 mRNA in intestine tissues, and reduced body weight and death from neonatal sepsis. Fecal samples from term infants, but not preterm infants, had significantly higher levels of S100A8-A9 during the first 3 months of life than fecal samples from adults; levels decreased to adult levels after weaning. Fecal samples from infants born by cesarean delivery had lower levels of S100A8-A9 than from infants born by vaginal delivery. S100 proteins were expressed by lamina propria macrophages in intestinal tissues from infants, at higher levels than in intestinal tissues from adults. High fecal levels of S100 proteins, from 30 days to 1 year of age, were associated with higher abundance of Actinobacteria and Bifidobacteriaceae, and lower abundance of Gammaproteobacteria-particularly opportunistic Enterobacteriaceae. A low level of S100 proteins in infants' fecal samples associated with development of sepsis and obesity by age 2 years.

CONCLUSION

S100A8 and S100A9 regulate development of the intestinal microbiota and immune system in neonates. Nutritional supplementation with these proteins might aide in development of preterm infants and prevent microbiota-associated disorders in later years.

Can fecal calprotectin serve as a screen for necrotizing enterocolitis in infants?

BACKGROUND

Researchers are debating if fecal calprotectin results are useful for infant patients, especially in screening for necrotizing enterocolitis (NEC). Currently, none of the FDA-approved calprotectin assays provide a cut-off for infant patients. We retrospectively analyzed data from a reference laboratory and university hospital to investigate if a cut-off could be established for infant patients.

METHODS

Data from a national reference laboratory of 5144 test results for fecal calprotectin were analyzed for infant patients, and a cut-off was estimated based on the distribution of results. Additionally, a literature proposed cut-off of 226 μg/g was also considered. Validation of either cut-off was attempted by review of the electronic medical record of our university hospital for 110 infant patients with results for fecal calprotectin.

RESULTS

Infants had a high percentage of elevated fecal calprotectin results when using the adult cut-offs set by the manufacturer. A cut-off of 247 μg/g was estimated based on the reference laboratory results for infants 0-2 months old, which is similar to a literature proposed cut-off of 226 μg/g. However, the positive predictive value (PPV) for both cut-offs was <0.6 when retrospectively analyzing data from a university hospital.

CONCLUSION

Due to the low PPVs, the two infant-specific cut-offs for fecal calprotectin would not be useful to screen for NEC in infants at our university hospital.

Normative values for circulating intestinal fatty acid binding protein and calprotectin across gestational ages

Background

Necrotizing enterocolitis (NEC) is associated with significant morbidity and mortality. Serum biomarkers to aid diagnosis, such as intestinal fatty acid binding protein (IFABP) and calprotectin, are actively being investigated; however, the normative values of these markers among healthy premature and term infants remains unknown. We sought to identify normative values for the serum concentrations of IFABP and calprotectin across gestational (GA) and post-menstrual age.

Methods

We collected serum from infants (24–40 weeks GA) in the first week of life and at multiple time points in a sub-cohort of premature infants (24–29 weeks GA), excluding sepsis or known intestinal disease. IFABP and calprotectin were measured using ELISA. Groups were compared with descriptive statistics and mixed effects linear regression.

Results

One hundred twelve infants had specimens in the first week of life, and 19 premature infants had longitudinal specimens. IFABP concentration in the first week of life was low and did not differ across gestational ages. Longitudinally, IFABP increased 4% per day (P < 0.001). Calprotectin concentration in the first week of life was more variable. An inverse relationship between day of life and calprotectin level was found in the longitudinal cohort (P < 0.001).

Conclusions

Serum IFABP and calprotectin fluctuate over time. Infants had low levels of IFABP during the first week of life, independent of gestational age, and levels increased longitudinally in premature infants. Calprotectin levels generally declined over time. Normative data for infants is necessary to establish meaningful cut-off levels for clinical use.

Effect of Aspiration and Evaluation of Gastric Residuals on Intestinal Inflammation, Bleeding, and Gastrointestinal Peptide Level

OBJECTIVE

To determine the effect of gastric residual aspiration and evaluation on preterm very low birth weight infants' gastrointestinal function, intestinal inflammation, and gastrointestinal mucosal bleeding.

STUDY DESIGN

This single-center, randomized trial compared omission of gastric residuals vs prefeed gastric residuals in 143 infants ≤32 weeks of gestation with a birthweight of ≤1250 g for 6 weeks after birth. Serum levels of gastrin and motilin were collected between 14 and 21 days of life. Stools were collected at 3 and 6 weeks of age and analyzed for calprotectin and S100A12 levels. All stools were tested for occult blood for 6 weeks.

RESULTS

Means for gastrin (P = .999) and motilin (P = .694) were similar between groups and there were no statistically significant differences in adjusted means for transformed calprotectin (P = .580), and S100A12 (P = .212). Both calprotectin (P = .003) and S100A12 (P = .002) increased from week 3 to week 6. The mean percentage of stools positive for occult blood (P = .888) were similar between the groups.

CONCLUSIONS

Gastrointestinal function, intestinal inflammation, and gastrointestinal mucosal bleeding were similar whether aspiration and evaluation of gastric residuals were eliminated or not, suggesting routinely evaluating gastric residuals before every feeding may be unnecessary. TRIAL REGISTRATION CLINICALTRIALS.GOV:: NCT01863043.

Effect of Different Milk Diet on the Level of Fecal Calprotectin in Very Preterm Infants

Objective: To evaluate the course of fecal calprotectin (FC) in very preterm infants over the first 15 days of life in relation to the type of milk diet. Methods: This study was part of a randomized controlled trial comparing two different ways of integrating the own mother's milk (OMM) for the evaluation of feeding tolerance in very preterm infants. In infants with gestational age of ≤ 32 weeks randomized to receive preterm formula (PF group) or pasteurized donor human milk (PDHM group) as a supplement to the OMM insufficient or unavailable, FC level was planned to be measured at the first meconium passage and at days 8 and 15 of life (T0, T1, and T2, respectively). Results: FC data were available for all the 70 infants randomized, 35 in the PF group, and 35 in the PDHM group. The mean FC levels were similar in the two study groups at T0 and T1, whereas they were significantly higher in the PF group than the PDHM group at T2. FC values decreased over the first week of life in both groups and significantly increased over the second week of life only in the PF group. Conclusions: Our study demonstrates a significant increase in FC levels when PF is used as a supplement to the OMM compared to the use of PDHM. Further studies are needed to establish if the higher FC levels in infants receiving PF are the expression of a normal immunological maturation rather than an initial inflammatory process.

Normal fecal calprotectin levels in healthy children are higher than in adults and decrease with age

Background/Objectives

The paediatric reference range of fecal calprotectin (FC) has not been decisively established and previous studies show a wide within-age variability, suggesting that other factors like anthropometric data or type of feeding can influence FC. Our aims were to establish the normal levels of FC in healthy children grouped by age and analyze whether sex, gestational age, birth weight, type of delivery, type of feeding, or anthropometric data influence FC values.

Methods

This multicentre, cross-sectional, and observational study enrolled healthy donors under 18 years of age who attended their Primary Health Care Centre for their routine Healthy Child Program visits. The exclusion criteria were: (i) immunodeficiency, (ii) autoimmune or (iii) gastrointestinal disease; (iv) medication usage; (v) gastrointestinal symptoms; or (vi) positive finding in the microbiological study.

Results

We enrolled 395 subjects, mean age was 4.2 years (range 3 days to 16.9 years), and 204 were male. The median FC was 77.0 mcg/g (interquartile range 246). A negative correlation between age and FC was observed (Spearman's rho = -0.603, P<0.01), and none of the other factors analyzed were found to influence FC levels.

Conclusions

Normal FC values in healthy children (particularly in infants) are higher than those considered to be altered in adults and show a negative correlation with age. It is necessary to reconsider the upper limits of FC levels for paediatric patients according to age, with further studies required to determine other factors that influence FC during infancy.

New insights into necrotizing enterocolitis: From laboratory observation to personalized prevention and treatment

BACKGROUND/PURPOSE

Necrotizing enterocolitis (NEC) is a devastating disease of prematurity that develops after feeding, often without warning, and results in diffuse intestinal necrosis leading to sepsis and death in many cases. The lack of improvement in overall survival is influenced by nonspecific diagnostic modalities as well as inexact and nonpersonalized treatment strategies.

METHODS/RESULTS

Recently, we and others have shown that NEC develops in response to exaggerated bacterial signaling in the premature intestine, as a consequence of elevated expression and activity of the bacterial receptor toll-like receptor 4 (TLR4), which is important for normal gut development. Breast milk is a powerful TLR4 inhibitor, while mutations in TLR4 genes lead to increased NEC risk in humans, providing proof-of-concept for its role in NEC. Recently, a drug discovery approach has revealed a novel class of TLR4 inhibitors which are being developed for personalized approaches to NEC treatment.

CONCLUSION

This review will highlight the current understanding of the role of bacterial signaling in NEC pathogenesis, and will describe advances in diagnosis, prevention and treatment of NEC that may hopefully improve survival for these most fragile patients.

SYSTEMATIC REVIEW

Level of Evidence: Level II.

Plasma miR-1290 Is a Novel and Specific Biomarker for Early Diagnosis of Necrotizing Enterocolitis-Biomarker Discovery with Prospective Cohort Evaluation

OBJECTIVE

To discover specific circulating microRNA (miRNA) biomarkers for the early differentiation of necrotizing enterocolitis (NEC) from neonatal sepsis and inflammatory conditions.

STUDY DESIGN

The study comprised 3 distinct phases: differential microarray analysis to compare plasma miRNA expression profiles of NEC vs sepsis and non-NEC/nonsepsis cases, a case-control study to quantify dysregulated miRNAs as potential specific biomarkers of NEC, and a prospective cohort study to assess the diagnostic usefulness of the best miRNA biomarker(s).

RESULTS

A distinct miRNA expression profile was observed in the NEC compared with the sepsis and non-NEC/nonsepsis groups. miR-1290, miR-1246, and miR-375 were discovered to be specific biomarkers of NEC in the case-control study. In the cohort study (n = 301), plasma miR-1290 (day 0; >220 copies/µL) provided the greatest diagnostic usefulness for identifying both mild medical and severe surgical NEC cases. Of 20 infants with miR-1290 >650 copies/µL, 15 were diagnosed with NEC. Incorporating C-reactive protein (day 1; >15.8 mg/L) for cases with intermediate levels (220-650 copies/µL) in a 2-stage algorithm further optimized the diagnostic profile with a sensitivity of 0.83, a specificity of 0.96, a positive predictive value of 0.75, and a negative predictive value of 0.98. Importantly, 7 of 36 infants with NEC (19.4%) could be diagnosed 7.8-32.2 hours earlier (median, 13.3 hours) using miR-1290.

CONCLUSIONS

Plasma miR-1290 is a novel and specific biomarker that can effectively differentiate NEC cases from neonatal sepsis. miR-1290 facilitates neonatologists to confidently and timely reach a decision for early transfer of sick infants with NEC from community-based hospitals to tertiary surgical centers.

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.

Impact of an In-House Pediatric Surgery Unit and Human Milk Centered Enteral Nutrition on Necrotizing Enterocolitis

The importance for mortality and morbidity of an in-house pediatric surgery unit for premature infants with necrotizing enterocolitis (NEC) remains undefined. Data on 389 consecutive very low birth weight infants with a birth weight <1250 g admitted between 2009 and 2014 was retrospectively analyzed in two almost identical neonatal intensive care units. Epidemiological data (n=172 and n=217, respectively) were comparable. Incidence of NEC stage II+ was significantly higher in center 1 (15.1 versus 5.5%, n=18 versus 6). This correlated with a significantly lower rate of exclusive human milk feeding compared to center 2 (24.2 versus 59.3%). Probiotic treatment did not differ. Importantly, in case of surgery the length of removed intestine (49.9 versus 19.5 cm) and the rate of severe short-bowel syndrome (38.9 versus 0 %) were significantly higher in center 1 (no in-house pediatric surgery). Furthermore, long-term morbidity assessment revealed more impaired motoric (-4.2 versus -2.2 months, p=0.21) and psychologic (-4.3 versus -1.6 months, p=0.09) development in center 1. Mortality was similar in both centers. Conclusions. Short- and possibly also long-term morbidity of NEC is clearly associated with the presence of an on-site pediatric surgery unit. Enteral nutrition with human milk seems to be a strong protective factor against NEC.

Multifarious diagnostic possibilities of the S100 protein family: predominantly in pediatrics and neonatology

BACKGROUND

Numerous articles related to S100 proteins have been recently published. This review aims to introduce this large protein family and its importance in the diagnostics of many pathological conditions in children and adults.

DATA SOURCES

Based on original publications found in database systems, we summarize the current knowledge about the S100 protein group and highlight the most important proteins with focus on pediatric use.

RESULTS

The S100 family is composed of Ca²⁺ and Zn²⁺ binding proteins, which are present only in vertebrates. Some of these proteins can be used as diagnostic markers in cardiology (S100A1, S100A12), oncology (S100A2, S100A5, S100A6, S100A14, S100A16, S100P, S100B), neurology (S100B), rheumatology (S100A8/A9, S100A4, S100A6, and S100A12), nephrology and infections (S100A8, S100A9, S100A8/A9, S100A12). The most useful S100 proteins in pediatrics are S100A8, S100A9, heterodimers S100A8/A9, S100B and S100A12.

CONCLUSIONS

The S100 family members are promising biomarkers and provide numerous possibilities for implementation into clinical practice to optimize the differential diagnostic process.

Amino Acid-Based Formula in Premature Infants with Feeding Intolerance: Comparison of Fecal Calprotectin Level

PURPOSE

We investigated fecal calprotectin (FC) levels in preterm infants with and without feeding intolerance (FI), and compared the FC levels according to the type of feeding.

METHODS

The medical records of 67 premature infants were reviewed retrospectively. The fully enteral-fed infants were classified into two groups; the FI group (29 infants) and the control group (31 infants). Seven infants with necrotizing enterocolitis, sepsis, and perinatal asphyxia were excluded. If breast milk (BM) or preterm formula (PF) could not be tolerated by infants with FI, amino acid-based formula (AAF) was tried temporarily. Once FI improved, AAF was discontinued, and BM or PF was resumed. We investigated the FC levels according to the type of feeding.

RESULTS

Significant differences were found in gestational age, birth weight, age when full enteral feeding was achieved, and hospital stay between the FI and control group (p<0.05). The FC levels in the FI group were significantly higher than those in the control group (p<0.05). The FC levels in the AAF-fed infants with FI were significantly lower than those in the BM- or PF-fed infants (p<0.05). The growth velocities (g/d) and z scores were not significantly different between the FI and control group (p>0.05).

CONCLUSION

The FC levels in AAF-fed infants with FI showed significantly lower than those in the BM- or PF-fed infants with FI. The mitigation of gut inflammation through the decrease of FC levels in AAF-fed infants with FI could be presumed.

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.

Biomarkers of necrotizing enterocolitis: a review of literature

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

Surgical necrotizing enterocolitis

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

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Fecal calprotectin levels in preterm infants with and without feeding intolerance

OBJECTIVES

To assess the level of fecal calprotectin in preterm neonates with feeding intolerance, as well as to evaluate it as a marker of feeding intolerance and to determine a cut-off level of fecal calprotectin in feeding intolerance.

METHODS

Analytical, multicenter, case-control study, which was carried out in neonatal intensive care units in Egypt, in a period from August 1, 2014 to March 1, 2015 on 52 preterm neonates. Neonates were classified into two groups; a study group including 26 neonates who met inclusion criteria and a control group including 26 neonates for comparison.

RESULTS

Fecal calprotectin levels ranged from 3.9μg/g to 971.8μg/g, and there was a significant increase in fecal calprotectin in the study group when compared to the control group (334.3±236.6μg/g vs. 42.0±38.2μg/g, respectively) with moderate inverse significant correlation between fecal calprotectin and birth weight. Furthermore, there was moderate, significant correlation between fecal calprotectin and duration of breastfeeding range. On the other hand, there was no correlation between fecal calprotectin and post-natal age, gestational age, or volume of feeding. A cut-off at the 67.0μg/g level, with 100.0% sensitivity and 76.9% specificity, was considered.

CONCLUSION

Fecal calprotectin level increased significantly in neonates with feeding intolerance; it can be used to detect early cases with necrotizing enterocolitis in neonates, but this subject still needs more investigations on more patients.

Calprotectin: Clinical Applications in Pediatrics

As seen over the past 20 years, calprotectin has evolved as a novel, non-invasive biomarker of gastrointestinal (GI) inflammation. We present this review of calprotectin in pediatrics. This article will focus on studies using calprotectin concentrations from different body fluids to monitor inflammation in different disease states and conditions. The ultimate goal of our group is to lay down a foundation as we consider using calprotectin prospectively as a marker of intestinal inflammation that could lead to further testing and possibly a marker of preparedness for feeding. We surveyed all published studies in English of calprotectin in neonates, infants, children, and adolescents through February 2014. We will discuss calprotectin's basic properties and analysis such as characteristics, identification, presence in body fluids, and maturational development. In addition, calprotectin's use in inflammatory diseases exploring both GI and non-GI conditions will be evaluated and compared with other serum markers presently available. Finally, a summary of our findings and discussion of future work that could be undertaken in order to render calprotectin as a more useful monitoring tool to the medical research community will complete the review.

Relationships of Feeding and Mother's Own Milk with Fecal Calprotectin Levels in Preterm Infants

OBJECTIVE

To describe longitudinal effects of feeding volume and type of milk on fecal calprotectin (f-CP) in very low-birth weight (VLBW) infants.

STUDY DESIGN

Prospective data were collected across Neonatal Intensive Care Unit (NICU) admission for 6 weeks or until discharge in 75 VLBW neonates. The mean gestational age on entry into the study was 29 weeks.

RESULTS

Seventy-four (99%) mothers provided expressed milk in varying amounts. Twenty-three mothers (31%) provided exclusive mother's own milk (MOM) throughout. Preterm infant formula (PIF) and pasteurized donor milk were added to feedings of remaining infants. Pooled MOM was analyzed weekly for levels of a panel of cytokines, chemokines, and growth factors, and secretory Immunoglobulin A (sIgA) so that the exact amount of exposure to the gut of these milk bioactives could be estimated. f-CP levels ranged from 160 to 350 μg/g stool. Total feeding volume was positively associated with f-CP, controlling for infant weight, and f-CP levels rose across time. Exclusive MOM feedings for the entire measurement period were associated with rising levels of f-CP, but mixed feedings (MOM with added PIF or pasteurized donor milk (PDM) did not show this increase over time.

CONCLUSION

The presence of f-CP may represent a response to milk volumes and MOM, which represents normal development rather than always implicating pathological inflammation in the VLBW infant.

Introduction of Bovine-Based Nutrient Fortifier and Gastrointestinal Inflammation in Very Low Birth Weight Infants as Measured by Fecal Calprotectin

BACKGROUND

Fecal calprotectin (fCP) is a biomarker of gastrointestinal tract (GIT) inflammation that is currently being used investigationally among very low birth weight (VLBW) infants.

MATERIALS AND METHODS

Stool was collected weekly from 20 breastmilk-fed VLBW infants for up to 8 weeks after birth during the establishment and fortification of feeds, and fCP concentrations were measured.

RESULTS

Mean fCP levels increased significantly in stools collected immediately following bovine-based nutrient fortification of feeds (p = 0.005).

CONCLUSIONS

Addition of bovine fortifier to breastmilk feeds appeared to be associated with an acute increase in GIT inflammation.

The use of laboratory biomarkers for surveillance, diagnosis and prediction of clinical outcomes in neonatal sepsis and necrotising enterocolitis

Biomarkers have been used to differentiate systemic neonatal infection and necrotising enterocolitis (NEC) from other non-infective neonatal conditions that share similar clinical features. With increasing understanding in biochemical characteristics of different categories of biomarkers, a specific mediator or a panel of mediators have been used in different aspects of clinical management in neonatal sepsis/NEC. This review focuses on how these biomarkers can be used in real-life clinical settings for daily surveillance, bedside point-of-care testing, early diagnosis and predicting the severity and prognosis of neonatal sepsis/NEC. In addition, with recent development of 'multi-omic' approaches and rapid advancement in knowledge of bioinformatics, more novel biomarkers and unique signatures of mediators would be discovered for diagnosis of specific diseases and organ injuries.

Introducing enteral feeding induces intestinal subclinical inflammation and respective chromatin changes in preterm pigs

Aim: To analyze how enteral food introduction affects intestinal gene regulation and chromatin structure in preterm pigs. Materials & methods: Preterm pigs were fed parenteral nutrition plus/minus slowly increasing volumes of enteral nutrition. Intestinal gene-expression and chromatin structure were analyzed 5 days after birth. Results: Enteral feeding led to differential upregulation of inflammatory and pattern recognition receptor genes, including IL8 (median: 5.8, 95% CI: 3.9–7.8 for formula; median: 2.2, 95% CI: 1.3–3.3 for colostrum) and TLR4 (median: 3.7, 95% CI: 2.6–4.8 for formula; no significant differences for colostrum) with corresponding decondensed chromatin configurations. On histology this correlated with mild mucosal lesions, particularly in formula-fed pigs. In CaCo-2 cells, histone hyperacetylation led to a marked increase in TLR4 mRNA and increased IL8 expression upon stimulation with lipopolysaccharide (median: 7.0; interquartile range: 5.63–8.85) compared with naive cells (median 4.2; interquartile range: 2.45–6.33; p = 0.03). Conclusion: Enteral feeding, particular with formula, induces subclinical inflammation in the premature intestine and more open chromatin structure in key inflammatory genes. This may increase the susceptibility for necrotizing enterocolitis.

A novel scoring system to predict the development of necrotizing enterocolitis totalis in premature infants

BACKGROUND/PURPOSE

Necrotizing enterocolitis totalis (NEC-totalis) is the severest form of NEC, with mortality rate of almost 100% even in the busiest neonatal centers. Despite such a prognosis, its risk factors remain elusive. We seek to identify clinical and laboratory parameters that differentiate NEC-totalis from NEC, and to use these factors to develop a scoring system to identify patients at risk for NEC-totalis upon presentation.

METHOD

NEC patients were identified from our electronic medical record using ICD9 code. Diagnosis of NEC-totalis was based on operative and autopsy reports. Patients were divided into 2 groups: NEC-but-no-totalis and NEC-totalis. Clinical/laboratory data were obtained for each group. T-test, multivariate logistic regression and backward stepwise regression analysis were performed to identify risk factors for NEC-totalis and these risk factors were formulated into a "Totalis Score."

RESULT

Among 157 NEC patients, 13 had NEC-totalis. NEC-totalis patients, compared to NEC alone, had fewer platelets, older age at diagnosis of NEC and greater phosphorus and creatinine levels. A 0-5 point scale "Totalis Score" based on these risk factors had sensitivity of 92% and a specificity of 78% for the diagnosis of NEC-totalis.

CONCLUSION

Low platelet, high phosphorus, high creatinine and older age at diagnosis of NEC were associated with a greater risk of developing NEC-totalis.

Predicting disease severity of necrotizing enterocolitis: how to identify infants for future novel therapies

Necrotizing enterocolitis (NEC) remains a very devastating problem within the very low birth weight neonatal population. Several experimental therapies are being tested in animal models and soon may be ready for human trials. Despite this progress, we currently have no way to identify infants who would be optimal targets for therapy. Specifically, we are unable to predict which infants will progress to the more severe Bell's stage of disease that may necessitate surgery. Ideally, an algorithm could be constructed that would encompass multiple neonatal and maternal risk factors as well as potential biologic markers of disease so that these infants could be identified in a more timely fashion. This review summarizes the known risk factors and biomarkers of disease in hopes of stimulating clinical research to identify such an “early warning” NEC algorithm.

Stool calprotectin in necrotizing enterocolitis

Background:

Calprotectin is a 36 kDa protein present in the cytoplasm of the neutrophil has antimicrobial and apoptosis inducing activities. In vitro studies have shown that calprotectin inhibits the growth of various microorganisms. Necrotizing enterocolitis (NEC) remains one of the leading causes of morbidity and mortality in neonatal intensive care units (NICU), affecting up to 5% of premature infants. Fecal calprotectin is resistant to degradation and has been proposed as a useful marker of gastrointestinal inflammation.

Objective:

The objective of the present study is to evaluate fecal calprotectin concentrations in NEC.

Study Design:

Fifteen neonates with a clinical diagnosis of NEC were studied; they admitted at NICU of Zagazig University Hospital. In addition, 20 age sex matched neonates fed all caloric requirement served as the control group. All neonates were subjected to history taking, clinical examination, laboratory investigations (complete blood count, C-reactive protein) and determination of stool calprotectin.

Results:

There was a highly significant increase in fecal calprotectin in patients than control and there was a highly significant increase in its fecal level in died patients than living one. Also significant increase in fecal calprotectin level with increasing severity of NEC.

Conclusion:

Fecal calprotectin measurements could be a valuable tool for the investigation of preterm and full term infants suspected of having NEC.

Differential expression of antimicrobial polypeptides in cord blood samples of preterm and term infants

AIM

To determine levels of antimicrobial polypeptides (AMP) in cord blood of term and preterm neonates and to investigate influencing factors.

METHODS

In a single-centre study, n = 139 preterm infants and n = 36 term infants were included. AMP levels were analysed in supernatants of whole cord blood cultures with a standardised concentration of 5 × 10(6) white blood cells/mL via enzyme-linked immunosorbent assay (ELISA).

RESULTS

Lactoferrin, human neutrophil peptides (HNP) 1-3 and bacterial permeability-increasing protein (BPI) expression in cord blood of preterm infants were influenced by the cause of preterm delivery, that is increased levels in infants with clinical amniotic infection. AMP levels also weakly correlated with white blood cell and neutrophil count at birth. In the whole cohort, no association between gestational age or birthweight with AMP levels was found. In the subgroup of infants without clinical amniotic infection (n = 77 preterm infants, n = 36 healthy term infants), we noted a weak correlation between gestational age and lactoferrin, calprotectin and HNP1-3 levels. In addition to that, we observed higher levels of lactoferrin and HNP1-3 in large-for-gestational-age infants.

CONCLUSION

Our study confirms that several factors influence cord blood AMP levels which underlines the difficulties of using AMP levels as biomarkers of immunological response.

Biomarkers of necrotising enterocolitis

Different categories of biomarkers of necrotising enterocolitis (NEC), including (i) non-specific mediators of the inflammatory cascade, e.g. acute phase reactants, chemokines, cytokines, and cell surface antigens, (ii) enhanced non-specific biomarkers, and (iii) specific gut-associated proteins, have distinctive biochemical characteristics and properties. The appropriateness of using these mediators in specific clinical situations, and the pros and cons of their applications as indicators or predictors of intestinal injury and NEC are highlighted. Many potentially new biomarkers such as micro-RNA, volatile organic compounds and gut microbiomes are currently under investigation. A stringent protocol for biomarker discovery is revealed so that investigators can consider this methodology as a reference for future discovery of organ-specific and/or disease-specific biomarkers for preterm infants.

S100A12 and hBD2 correlate with the composition of the fecal microflora in ELBW infants and expansion of E. coli is associated with NEC

Objective. To describe the development of the gut microbiota in extremely low birth weight (ELBW) infants with and without necrotizing enterocolitis (NEC) between April 2008 and December 2009, fecal microflora was prospectively analyzed in fecal samples of all ELBW infants using real-time PCR assays. In addition, fecal inflammatory were measured. Results. Fecal microflora established early in ELBW infants and microbiota composition remained stable over the first 28 days of life except for the prevalence of C. difficile which decreased with decreasing antibiotic use. Infants who subsequently developed NEC had an increase of total bacterial count (9.8-fold) 24 h prior to clinical symptoms mainly due to the expansion of E. coli species (21.6-fold), whereas microbiota composition did not differ from healthy ELBW infants five days before onset of NEC. Importantly, S100A12 and hBD2 positively correlated with the total and E. coli bacterial CFU/g feces (r² 0.4 and 0.64, resp.). Conclusions. In summary, we found evidence for a disturbed homeostasis between the intestinal microbiome and host immunity in ELBW infants with NEC. Moreover, S100A12 and hBD2 correlate with the fecal microbiota thus linking the intestinal innate immune response to the bacterial colonization thus possibly providing a diagnostic tool in the future.

Fecal S100A12: identifying intestinal distress in very-low-birth-weight infants

OBJECTIVES

The aim of the study was to determine whether longitudinal measurements of fecal S100A12, a damage-associated molecular pattern protein, which is released from neutrophils or monocytes under stress, can detect very-low-birth-weight (VLBW) infants at risk for intestinal distress apart from necrotizing enterocolitis.

METHODS

This prospective study included 46 VLBW infants with intestinal distress and 49 reference patients. Meconium and stool samples were collected prospectively on alternate days for 4 weeks, and fecal S100A12 was measured by enzyme-linked immunosorbent assay.

RESULTS

Gestational age and weight at birth were significantly lower in patients with intestinal distress when compared to unaffected reference infants. Median levels of fecal S100A12 were significantly higher in patients with intestinal distress at onset of disease and before compared with unaffected reference infants. Median levels of fecal S100A12 declined steadily to baseline levels within 2 weeks after disease onset. The ideal cutoff value for identifying patients with intestinal distress within 7 days before disease onset was 60 μg/kg (sensitivity 0.73; specificity 0.55).

CONCLUSIONS

Fecal S100A12 levels are increased in VLBW infants with intestinal distress; however, the potential for S100A12 as an early biomarker is largely limited by overlaps between values of infants with intestinal distress and the reference population.

The importance of biomarkers in neonatology

Despite a 35% decline in the mortality rate for infants aged <5 years over the past two decades, every year nearly 40% of all deaths in this age group occur in the neonatal period, defined as the first 28 days of life. New knowledge on molecular and biochemical pathways in neonatal diseases will lead to the discovery of new candidate biomarkers potentially useful in clinical practice. In the era of personalized medicine, biomarkers may play a strategic role in accelerating the decline in neonatal mortality by assessing the risk of developing neonatal diseases, by implementing tailored therapeutic treatment, and by predicting the clinical outcome. However, there is an urgent need to reduce the gap in translating newly acquired knowledge from bench to bedside. Traditional and candidate biomarkers for neonatal sepsis and necrotizing enterocolitis will be discussed in this review, such as C-reactive protein (CRP), procalcitonin (PCT), serum amyloid A (SAA), soluble form of CD14 subtype presepsin (sCD14-ST), lipolysaccharide binding protein (LBP), angiopoietins (Ang)-1 and -2, soluble form of triggering receptor expressed on myeloid cells (sTREM-1), soluble form of urokinase-type plasminogen activator receptor (suPAR), platelet-activating factor (PAF) and calprotectin. New frontiers in managing critically ill newborns may be opened by metabolomics, a diagnostic tool based on the recognition of metabolites contained in biological fluids. Metabolomics represents the passage from a descriptive science to a predictive science, having the potential to translate benchtop research to real clinical benefits.