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Background: Necrotizing enterocolitis (NEC) is the most devastating gastrointestinal (GI) emergency in preterm neonates. Untargeted metabolomics may allow the identification of biomarkers involved in NEC pathophysiology., Methods: We conducted a prospective study including preterm infants born at < 34 gestational weeks (GWs) whose urine was longitudinally collected at birth (< 48 h, T0) and at 14 (T1) and 28 days (T2). Neonates were followed for their development of NEC, spontaneous intestinal perforation (SIP), or other GI conditions and compared to those of matched healthy controls. Urine samples were investigated by untargeted metabolomic analysis based on mass-spectrometry., Results: Thirty-five patients with NEC, 5 patients with SIP, 14 patients with other GI diseases and 113 controls were enrolled and selected for metabolomic analysis on the basis of their clinical characteristics and available samples. Considering urine samples at T0, the one-class classification approach was able to correctly classify 16/20 subjects (80%) who developed NEC, 3/3 (100%) who developed SIP and 5/7 subjects (71.4%) with other GI pathologies as not belonging to the control group. Neonates with surgical NEC had higher N-acetylaspartic acid, butyrylcarnitine and propionylcarnitine levels than did those with medical NEC. Considering the time evolution of the urinary metabolome, the NEC and control groups showed differences independently of the time point., Conclusions: The urinary metabolome is closely associated with the underlying GI disease from birth. Urinary metabolic features characterize NEC patients from healthy controls until 28 days of life. The early urinary metabolome has the potential to predict surgical NEC. Future studies are needed to validate our results., (© 2024. The Author(s).)

Prematurity-associated lung disease (PLD) is a long-term consequence of preterm-birth. Since the underlying mechanisms of PLD remain poorly characterised, we compared the urinary metabolome between recently described spirometry phenotypes of PLD. Preterm- and term-born children aged 7-12 years, from the Respiratory Health Outcomes in Neonates (RHiNO) cohort, underwent spirometry and urine collection. The urinary metabolome was analysed by gas chromatography time-of-flight mass spectrometry. Preterm-born children were classified into phenotypes of prematurity-associated obstructive lung disease (POLD, Forced expiratory volume in 1 s (FEV 1 ) < lower limit of normal (LLN), FEV 1 /Forced Vital Capacity (FVC) < LLN), prematurity-associated preserved ratio impaired spirometry (pPRISm, FEV 1  < LLN, FEV 1 /FVC ≥ LLN) and Preterm/Term controls (FEV 1  ≥ LLN). Metabolite set enrichment analysis was used to link significantly altered metabolites between the groups with metabolic pathways. Univariable and multivariable linear regression models examined associations between early and current life factors and significantly altered metabolites of interest. Urine from 197 preterm- and 94 term-born children was analysed. 23 and 25 were classified into POLD and pPRISm groups respectively. Of 242 identified metabolites, 49 metabolites were significantly altered in the POLD group compared with Preterm controls. Decreased capric acid (log 2 fold change - 0.23; p = 0.003), caprylic acid (- 0.18; 0.003) and ceratinic acid (- 0.64; 0.014) in the POLD group, when compared to preterm controls, were linked with reduced β-oxidation of very long chain fatty acids (p = 0.004). Reduced alanine (log 2 fold change - 0.21; p = 0.046), glutamic acid (- 0.24; 0.023), and pyroglutamic acid (- 0.17; 0.035) were linked with decreased glutathione metabolism (p = 0.008). These metabolites remained significantly associated with POLD in multivariable models adjusting for early/current life factors. The pPRISm urinary metabolome was minimally changed when compared with preterm-born controls. When compared to term-born subjects, alterations in tryptophan metabolism were implicated (p = 0.01). The urinary metabolome in POLD showed significantly altered β-oxidation of fatty acids and glutathione metabolism, implying alterations in cellular metabolism and oxidative stress. Similar findings have been noted in adults with chronic obstructive pulmonary disease. Given the similarity of findings between the POLD group and those reported for COPD, the POLD group should be considered at future risk of developing COPD., (© 2024. The Author(s).)

Background: Urine sodium concentration has been suggested as a marker to guide enteral sodium supplementation in preterm infants; however, no previous data have demonstrated relationships between urine sodium concentration and postnatal growth., Methods: We performed a single-center retrospective cohort study on 224 preterm infants admitted to the neonatal intensive care unit at the Children's Hospital of Georgia between January 2010 and July 2022. Spot urine sodium was measured in preterm infants (<34 weeks postmenstrual age [PMA]) between days of life (DOLs) 7 and 28. Our exposure of interest was spot urine sodium concentration (milliequivalents per liter) obtained between postnatal days 7 and 28, and our primary outcome was weight velocity (grams per kilograms per day) determined at DOL 28. Statistical relationships were assessed by multivariate analysis with subgroup comparisons by Student t test and analysis of variance., Results: In 224 preterm infants (199 ± 17 days, 56% male, 71% Black), urine sodium concentration did not associate with weight velocity at DOL 28 and 36 weeks PMA. Urine sodium concentration was weakly associated with gestational age at birth, and Black preterm infants had higher urine sodium values when compared with "other," but not White preterm infants., Conclusion: Spot urine sodium during the first month of life does not associate with weight velocity at DOL 28 or 36 weeks PMA., (© 2024 American Society for Parenteral and Enteral Nutrition.)

Aim: To evaluate the urinary biomarkers related to sepsis in preterm newborns (NBs) and to investigate the predictive capacity of these biomarkers for a longer hospital stay. Methods: Serum and urine were collected from 27 healthy NBs, 24 NBs with neonatal infection without sepsis and 11 NBs with sepsis for the measurement of sindecan-1, lipocalin associated with urinary neutrophil gelatinase (uNGAL), urinary cystatin-C (uCysC) and urinary kidney injury molecule-1. Results: Levels of uNGAL and urinary cystatin-C were elevated in NBs with sepsis and neonatal infection, and uNGAL was significant predictor of hospital stay longer than 30 days (odds ratio: 1.052; 95% CI: 1.012-1.093; p  = 0.01). Conclusion: uNGAL was associated with sepsis in preterm NBs and was useful to predict extended hospital stay.

· POCUS is a dynamic way of assessing cardiopulmonary function.. · POCUS would be more cost-effective than urine NT-proBNP.. · Although POCUS is costly as compared with urine NT-proBNP, it is a one-time investment.., Competing Interests: None declared., (Thieme. All rights reserved.)

Introduction: Preterm infants are at risk for a variety of somatic and neurological disorders. In recent years, biofluid proteomics has emerged as a potential diagnostic tool for biomarker analysis. The aim of this study was to determine gestational age (GA)-related patterns of the urinary peptidome in preterm infants for researching potential novel prognostic biomarkers., Methods: We performed urinary peptidomics in longitudinal samples of 24 preterm (mean GA weeks 28 + 1 [24+1-31 + 6]) and 27 term born controls (mean GA weeks 39 + 2 [37+0-41 + 1]) using capillary electrophoresis combined with mass spectrometry (CE-MS). Peptides were sequenced using CE-MS/MS or LC-MS/MS analysis and were deposited, matched, and annotated in a Microsoft SQL database for statistical analysis. We compared their abundance in urine of preterm and term born infants and performed a validation analysis as well as correlations to GA and clinical risk scores., Results: Our results confirmed significant differences in the abundance of peptides and the hypothesis of age-dependent urinary peptidome changes in preterm and term infants. In preterm infants, SLC38A10 (solute carrier family 38 member 10) is one of the most abundant peptides. Combined urinary peptides correlated with clinical risk scores (p &lt; 0.05)., Conclusion: This is the first study reporting GA-related urinary peptidome changes of preterm infants detected by CE-MS and a modulation of the peptidome with GA. Further research is required to locate peptidome clusters correlated with specific clinical complications and long-term outcome. This may identify preterm infants at higher risk for adverse outcome who would benefit from early intervention., (© 2024 S. Karger AG, Basel.)

Introduction: Hyaluronan (HA) is a major component of the extracellular matrix. Increased pulmonary HA concentrations are associated with several respiratory disorders and is a pathophysiological feature of lung disease. We investigated whether elevated urine HA is a biomarker of an unfavorable 40-week respiratory outcome in preterm infants., Methods: Infants comprised a cohort of preterm neonates &lt;31 weeks gestational age (GA) from the Prematurity-Related Ventilatory Control (Pre-Vent) multicenter study. HA was quantified in urine obtained at 1 week and 1 month of age. Respiratory status at 40 weeks post-menstrual age (PMA) was classified as unfavorable [either (1) deceased at or before 40 weeks PMA, (2) an inpatient on respiratory medication, O2 or other respiratory support at 40 weeks, or (3) discharged prior to 40 weeks on medications/O2/other respiratory support], or favorable (alive and previously discharged, or inpatient and off respiratory medications, off O2, and off other respiratory support at 40 weeks PMA). The association between urine HA and the unfavorable 40 week PMA outcome was examined using a multivariate logistic generalized estimation equation model., Results: Infants with higher HA at 1 week (but not 1 month) showed increased odds of unfavorable respiratory outcome at 40 weeks PMA (OR [95% CI] = 1.87 per 0.01 mg [1.27, 2.73])., Discussion and Conclusion: Neonatal urine screening for HA could identify infants at risk for death or need for respiratory support at term-corrected age (40 weeks PMA). The relationship between elevated HA at 1 week and an unfavorable 40 week outcome was stronger in infants with lower GA., (© 2024 S. Karger AG, Basel.)

Objective: The aim of this study was to determine the effects of a 2-day prenatal course of indomethacin on the premature kidney as reflected by serum creatinine and urinary biomarkers., Study Design: Urine of infants ≤32 weeks was collected for the first 14 days and analyzed for cystatin C, neutrophil gelatinase-associated lipocalin, osteopontin, β2 microglobulin, epidermal growth factor, uromodulin, and microalbumin. Bivariate analysis compared serum creatinine and biomarkers of exposed (INDO) and unexposed (CONT) subjects., Results: Fifty-seven infants (35 CONT and 22 INDO) were studied. The cohorts were similar in gestational age, birthweight, race, gender, nephrotoxic medication exposure, and Apgar's scores. CONT had more dopamine exposure and included more pre-eclamptic mothers ( p  = 0.005). No difference in creatinine-based acute kidney injury or the log transformed mean, maximum, and minimum values of urinary biomarkers was detected., Conclusion: Our findings suggest that a short course of tocolytic indomethacin does not result in neonatal acute kidney injury., Key Points: · A short prenatal course of indomethacin does not result in neonatal acute kidney injury (AKI).. · Urinary EGF might have a promising role as a more sensitive biomarker for early detection of AKI in premature infants.., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Our understanding of the normative concentrations of urine biomarkers in premature neonates is limited., Methods: We evaluated urine from 750 extremely low gestational age (GA) neonates without severe acute kidney injury (AKI) to determine how GA affects ten different urine biomarkers at birth and over the first 30 postnatal days. Then, we investigated if the urine biomarkers changed over time at 27, 30, and 34 weeks postmenstrual age (PMA). Next, we evaluated the impact of sex on urine biomarker concentrations at birth and over time. Finally, we evaluated if urine biomarkers were impacted by treatment with erythropoietin (Epo)., Results: We found that all ten biomarker concentrations differ at birth by GA and that some urine biomarker concentrations increase, while others decrease over time. At 27 weeks PMA, 7/10 urine biomarkers differed by GA. By 30 weeks PMA, 5/10 differed, and by 34 weeks PMA, only osteopontin differed by GA. About half of the biomarker concentrations differed by sex, and 4/10 showed different rates of change over time between males vs. females. We found no differences in urine biomarkers by treatment group., Conclusions: The temporal patterns, GA, and sex differences need to be considered in urine AKI biomarker analyses., Impact: Urine biomarker concentrations differ by GA at birth. Some urine biomarkers increase, while others decrease, over the first 30 postnatal days. Most urine biomarkers differ by GA at 27 weeks PMA, but are similar by 34 weeks PMA. Some urine biomarkers vary by sex in premature neonates. Urine biomarkers did not differ between neonates randomized to placebo vs. Epo., (© 2021. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.)

Background: Following preterm birth, the immature kidney is exposed to several harmful conditions, with an increased risk of renal impairment. We aimed to assess urinary biomarkers of renal function in very preterm infants during early nephrotoxic treatments., Methods: Infants ≤32 weeks' gestation and ≤1500 g were enrolled in this observational prospective study. Urine samples were collected on day 1(T1), 2-4(T2), 5-7(T3), 8-10(T4), 11-13(T5). The following urinary biomarkers were determined: osteopontin (uOPN), epidermal growth factor (uEGF), neutrophil gelatinase-associated lipocalin (uNGAL), cystatin C (uCysC). The infants were grouped according to their exposure to amikacin or ibuprofen during the study period and a between-group comparison of urinary biomarkers at each time point was performed., Results: Thirty-six infants were included. Urinary CysC, uOPN, and uNGAL rose significantly during ibuprofen or amikacin treatment, while no difference was observed for uEGF. After adjustment for possible influencing factors, amikacin administration was associated with higher uCysC at T1 (p = 0.007) and T2 (p = 0.016), whereas ibuprofen increased uOPN (p = 0.001) and uNGAL concentration (p = 0.009) at T3., Conclusion: Nephrotoxic therapies induce molecule-specific change patterns of renal function biomarkers in treated preterm infants. Serial assessments of these biomarkers may aid to identify neonates at risk of renal impairment and to develop tailored therapeutic approaches., Impact: Despite the wide use of nephrotoxic therapies in neonatal settings, little is known on their effect on renal function biomarkers in preterm infants. This study describes molecule-specific change patterns of urinary biomarkers during ibuprofen and amikacin administration, suggesting underlying pathophysiological effects on renal function. Given their low analytical costs and non-invasive collection, the urinary biomarkers investigated in this study represent a promising strategy for serial monitoring of renal function in at-risk neonates and may aid the early detection of renal function impairment at different kidney levels during nephrotoxic treatments., (© 2021. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.)

Acute kidney injury (AKI) is a susceptible factor for chronic kidney disease (CKD). There is still a lack of effective prevention methods in clinical practice. This study investigated the protective effect of the urinary exosomes from premature infants on cisplatin-induced acute kidney injury. Here we isolated exosomes from the fresh urine of premature infants. A C57BL/6 mice model of cisplatin-induced acute kidney injury was given 100 ug urinary exosomes 24 hours after model establishment. The kidneys were collected for pathological examination and the evaluation of renal tubular damage and apoptosis. In the in vitro experiment, human renal cortex/proximal tubular cells (HK-2) were induced by cisplatin to assess the effect of the urine exosomes from premature infants. Exosome microRNA (miRNA) sequencing technology was applied to investigate the miRNAs enriched in exosomes and the dual-luciferase gene reporter system to examine the targeting relationship of the miRNA with target genes. The results indicated that the urinary exosomes could decrease the serum creatinine level and the apoptosis of renal tubular cells, and reduce mice mortality. In addition, miR-30a-5p was the most abundant miRNA in the exosomes. It protected HK-2 cells from cisplatin-induced apoptosis by targeting and down-regulating the mitogen-activated protein kinase 8 (MAPK8). Together, our findings identified that the urinary exosomes derived from premature infants alleviated cisplatin-induced acute kidney injury and inhibited the apoptosis of HK-2 via miR-30a-5p, which could target MAPK8. These findings implied that urinary exosomes from premature infants riched in miR-30a-5p might become a potential treatment for AKI.

Context: Fetal zone steroids (FZSs) are excreted in high concentrations in preterm infants. Experimental data suggest protective effects of FZSs in models of neonatal disease., Objective: We aimed to characterize the postnatal FZS metabolome of well preterm and term infants., Methods: Twenty-four-hour urinary FZS excretion rates were determined in early preterm (<30 weeks' gestation), preterm (30-36 weeks), and term (>37 weeks) infants. Pregnenolone and 17-OH-pregnenolone metabolites (n = 5), and dehydroepiandrosterone sulfate and metabolites (n = 12) were measured by gas chromatography mass spectrometry. Postnatal concentrations of FZSs were compared with already published prenatal concentrations in amniotic fluid., Results: Excretion rates of total FZSs and most of the single metabolites were highest in early preterm infants. In this group, excretion rates approach those of term infants at term equivalent postmenstrual age. Preterm infants of 30-36 weeks had more than half lower median excretion rates of FZSs than early preterm infants at the same time of postmenstrual age. Postnatal concentrations of FZSs were partly more than 100-fold higher in all gestational age groups than prenatal concentrations in amniotic fluid at midgestation., Conclusion: The excretion rates of FZSs as a proxy of the involution of the fetal zone of the most immature preterm infants approached those of term infants at term equivalent. In contrast, the fetal zone in more mature preterm infants undergoes more rapid involution. These data in exclusively well neonates can serve as a basis to investigate the effects of illness on the FZS metabolome in future studies., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background & Aims: Human milk is the gold standard for infant nutrition. Preterm infants whose mothers are unable to provide sufficient own mother's milk (OMM), receive pasteurized donor human milk (DHM). We studied metabolic signatures of OMM and DHM and their effect on the interplay of the developing microbiota and infant's metabolism., Methods: Metabolic fingerprinting of OMM and DHM as well as infant's urine was performed using liquid chromatography-mass spectrometry and the infant's stool microbiota was analyzed by 16S rRNA sequencing., Results: Significant differences in the galactose and starch and sucrose metabolism pathways when comparing OMM and DHM, and alterations of the steroid hormone synthesis and pyrimidine metabolism pathways in urine were observed depending on the type of feeding. Differences in the gut-microbiota composition were also identified., Conclusion: The composition of DHM differs from OMM and feeding of DHM has a significant impact on the metabolic phenotype and microbiota of preterm infants. Our data help to understand the origin of the observed changes generating new hypothesis: i) steroid hormones present in HM have a significant influence in the activity of the steroid hormone biosynthesis pathway in preterm infants; ii) the pyrimidine metabolism is modulated in preterm infants by the activity of gut-microbiota. Short- and long-term implications of the observed changes for preterm infants need to be assessed in further studies., Competing Interests: Conflict of interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Infants in the neonatal intensive care unit may be exposed to ethanol via medications that contain ethanol as an excipient and through inhalation of ethanol vapor from hand sanitizers. We hypothesized that both pathways of exposure would result in elevated urinary biomarkers of ethanol., Methods: Urine samples were collected from infants in incubators and in open cribs. Two ethanol metabolites, ethyl sulfate (EtS) and ethyl glucuronide (EtG), were quantified in infants' urine., Results: A subset of infants both in incubators and open cribs had ethanol biomarkers greater than the cutoff concentration that identifies adult alcohol consumption. These concentrations were associated with the infant having received an ethanol-containing medication on the day of urine collection. When infants who received an ethanol-containing medication were excluded from analysis, there was no difference in ethanol biomarker concentrations between the incubator and crib groups., Conclusions: Some infants who received ethanol-containing medications had concentrations of ethanol biomarkers that are indicative of adult alcohol consumption, suggesting potential exposure via ethanol excipients., Impact: Infants and newborns in the neonatal intensive care unit are exposed to concerning amounts of ethanol. No one has shown exposure to ethanol in these infants before this study. The impact is that better understanding of the excipients in medications given to patients in the NICU is needed. When physicians order medications in the NICU, the amount of excipient needs to be indicated.

Fortification of human milk (HM) for preterm and very low-birth weight (VLBW) infants is a standard practice in most neonatal intensive care units. The optimal fortification strategy and the most suitable protein source for achieving better tolerance and growth rates for fortified infants are still being investigated. In a previous clinical trial, preterm and VLBW infants receiving supplementation of HM with experimental donkey milk-based fortifiers (D-HMF) showed decreased signs of feeding intolerance, including feeding interruptions, bilious gastric residuals and vomiting, with respect to infants receiving bovine milk-based fortifiers (B-HMF). In the present ancillary study, the urinary metabolome of infants fed B-HMF ( n = 27) and D-HMF ( n = 27) for 21 days was analyzed by 1 H NMR spectroscopy at the beginning (T0) and at the end (T1) of the observation period. Results showed that most temporal changes in the metabolic responses were common in the two groups, providing indications of postnatal adaptation. The significantly higher excretion of galactose in D-HMF and of carnitine, choline, lysine and leucine in B-HMF at T1 were likely due to different formulations. In conclusion, isocaloric and isoproteic HM fortification may result in different metabolic patterns, as a consequence of the different quality of the nutrients provided by the fortifiers.

Background: A major challenge from the moment a child is delivered is the adaptation to the extrauterine life, where rapid metabolic changes take place. The study of these changes during the first days of human life may assist in the understanding of the metabolic processes that occur at this critical period, which is likely to provide significant clinical insights. To date, metabolomics has become a powerful field, ideal for the monitoring of such dynamic variations, since it offers the possibility to identify alterations in metabolic profiles, even on daily basis., Methods: The study included 253 healthy newborns (GA 35 to 40 weeks) from the region of Western Greece. Urine samples were collected immediately after birth and at the third day of life. NMR-based metabolomics was used to compare the metabolic urinary profiles of newborns from the first and third day of their life, assessing the impact of six perinatal factors; delivery mode, prematurity, maternal smoking, gender, nutrition and neonatal jaundice., Results: Analysis of urine metabolic fingerprint from the first and third day of life, coupled with multivariate statistics, provides insights into the details of early life metabolic profile differentiation. Αt the third day of life metabolic adaptations are evident, as many differences were noted in urine of healthy neonates within the first 72 h postpartum. Trends in differentiation of metabolites levels between the two groups, late preterm and term newborns, have been also observed., Conclusions: Newborn's urine metabolic profiles confirmed the rapid changes in their metabolism after birth. Further, ongoing research will enable us to develop one reference model of urinary metabolomics in healthy newborns during the period of adaptation to the extra-uterine life.

Objective: This pilot study aimed to determine the feasibility of urinary NT-proBNP (NT-proBNP) as a potential noninvasive screening marker for pulmonary hypertension (PH)., Study Design: A prospective cross-sectional study was conducted. Preterm infants (PI) (birthweight <1500 gm and <30 weeks gestational age (GA)) were enrolled. Serial urinary NT-proBNP measurements and echocardiograms (ECHO) were performed at 28, 32, and 36 weeks., Results: Thirty-six patients were included in the final analysis (BPD-PH group = 6, BPD group = 20, control = 10). Urinary NT-proBNP levels were higher in the BPD-PH group compared with BPD and control groups at all study intervals. A urine NT-proBNP cutoff level of 2345 pg/ml at 28 weeks of GA had a sensitivity and specificity of 83.3% and 84.2%, respectively, for detection of BPD-PH (AUC 0.816, p = 0.022)., Conclusion: Urinary NT-proBNP measurement is feasible in preterm infants and appears to be a good noninvasive screening tool for PH.

The immature preterm kidney is likely to be vulnerable to acute kidney injury (AKI). However, the biomarkers currently used for AKI are not sensitive or specific and are also inadequate for the timely detection of AKI in preterm infants. The objectives of this study were to identify novel urinary biomarkers of AKI using proteomic techniques, and to verify and validate that the candidates can serve as early predictive biomarkers for AKI. In total, 1,810 proteins were identified in the discovery phase. Among those proteins, 174 were selected as the 1 st targeted proteins. A total of 168 proteins were quantified, and the levels of 6 were significantly increased in the AKI group in the verification phase. Using a clinical assay, the results were confirmed and validated using samples of the first urine after birth from the biorepository. Finally, enzyme-linked immunosorbent assays revealed that the levels of annexin A5, neutrophil gelatinase-associated lipocalin (NGAL), and protein S100-P were significantly higher in the samples of the first urine from patients with AKI than in those from patients without AKI. In conclusion, urinary annexin A5, NGAL and protein S100-P levels are promising biomarkers for early, accurate prediction of AKI in preterm infants.

Background: Early administration of colostrum may provide preterm infants with immune components. Previous studies illustrating the effects of oral colostrum (OC) have been confounded by the coincidence of enteral feedings., Objective: To quantify OC absorption, as measured by urinary sIgA and lactoferrin, in preterm infants prior to enteral feedings., Materials and Methods: Colostrum was obtained from mothers delivering infants ≤32 weeks and ≤1500 g. sIgA and lactoferrin were measured in infant urine, and microflora in saliva and tracheal aspirates were characterized., Results: Urinary sIgA and lactoferrin were significantly greater in infants receiving OC by syringe compared to swab (p < 0.002). Urinary sIgA correlated with the total number of doses in 72 h (R 2  = 43%, p < 0.01)., Conclusions: Administration of OC by syringe and higher cumulative dose are associated with increased absorption of sIgA and lactoferrin, and early dosing may contribute to a more diverse tracheal microbiome.

Background: Premature infants have a high concentration of conjugated bilirubin in their blood, although they have a poor glucuronide conjugation of bilirubin. This may be due to developmental changes in the function of adenosine triphosphate binding cassette subfamily C member 2, which is involved in the cellular export of conjugated bilirubin. In the present study, we examined the developmental changes in the urinary coproporphyrin I/(urinary coproporphyrin I+ urinary coproporphyrin III) ratio (UCP (I/ [I + III])), a known biomarker for adenosine triphosphate binding cassette subfamily C member 2 function, in premature infants., Method: Twenty-one premature infants born between 25 and 32 weeks of gestation were included in the study. Urine samples were collected within 24 h of birth, and at 1 week and 3-4 weeks after birth. The samples were analyzed by high-performance liquid chromatography to calculate UCP (I/ [I + III]) to examine its association with postnatal age and corrected gestational age. Subjects were excluded if they had liver dysfunction, cholestasis, urinary tract infection, or chromosomal abnormalities., Results: The average UCP (I/ [I + III]) within 24 h of birth, at 1 week, and at 3-4 weeks after birth was 0.84, 0.61, and 0.65, respectively. The UCP (I/ [I + III]) within 24 h of birth was significantly higher than that measured at 1 week or 3-4 weeks after birth. There was no significant correlation between UCP (I/ [I + III]) and the corrected gestational age., Conclusion: The UCP (I/ [I + III]) was higher within 24 h of birth. It decreased 1 week after birth and remained low without any significant changes for up to 4 weeks after birth., (© 2019 Japan Pediatric Society.)

Pasteurized donor human milk (DHM) is the preferred alternative for infant nutrition when own mother's milk (OMM) is unavailable. Whether DHM is an efficient means for protecting preterm infants from oxidative stress remains unknown. We quantified a panel of oxidative stress biomarkers in urine samples from preterm infants (≤32 weeks of gestation and a birth weight ≤1500 g) receiving ≥80% of feeding volume as either DHM or OMM. The noninvasive in vivo assessment of oxidative stress showed no statistically significant difference between both groups at the time when full enteral nutrition (150 mL/kg body weight) was achieved and until hospital discharge. In addition, the changes of urinary biomarker levels with time were assessed. This is the first longitudinal study on oxidative stress levels in preterm infants fed with DHM in comparison with OMM. There is no statistically significant difference in urinary oxidative stress levels of preterm infants from both groups indicating that despite the effects of pasteurization, DHM is a valid alternative when OMM is not available. Based on the results, we raise the hypothesis that pasteurized DHM protects preterm infants from oxidative stress as good as OMM, and consequently, its use could prevent oxidative stress-related diseases. Antioxid. Redox Signal . 31, 791-799.

Objective: Delivery room (DR) management may play an important role in the development and prevention of lung injury. Therefore, in a cohort of low birth weight infants (LBW), we investigated the effects of two different lung recruitment maneuvers, such as positive pressure ventilation (PPV) and sustained inflation (SI) on adrenomedullin (AM), a well-established lung-specific vasoactive agent., Study Design: This is a prospective case-control randomized study in 44 LBW infants spontaneously breathing with respiratory failure at birth requiring respiratory support. LBW were randomized to receive PPV ( n  = 22) or SI ( n  = 22) support. AM was measured from blood in samples collected at birth from arterial artery (BLT0) and at 1-hour (BLT1) and at 24-hour (BLT2) from peripheral venous site. AM assessment in urine samples was performed at 1-hour (URT1) and at 24-hour (URT2)., Results: No significant differences in AM ( p  > 0.05) blood (T0-T2) and urine (T1, T2) levels were observed between groups., Conclusion: The present data, showing the absence of any differences in AM blood and urine levels, suggest that PPV and SI are both feasible and equally effective DR maneuvers. The findings open the way to further studies evaluating the effects of PPV and SI on short-/long-term respiratory outcome through biomarkers assessment., Competing Interests: None declared., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Background: The postnatal gonadotrophin surge is sexually dimorphic: FSH levels predominate in girls and LH levels in boys. However, in preterm (PT) girls, both gonadotrophin levels are higher than in PT boys., Objective: To evaluate how gonadal maturation contributes to the sex differences in FSH and LH., Design: Monthly follow-up of 58 full-term (FT, 29 boys) and 67 PT (33 boys) infants from 1 week (D7) to 6 months of age (M1-M6). Analyses were also carried out according to postmenstrual (PM) age in PT infants., Methods: Urinary LH, FSH, oestradiol (E2), testosterone (T) and serum inhibin B (InhB) levels., Results: High gonadotrophin levels in PT girls abruptly decreased (P < .001) by M2, corresponding to a PM age of 38-42 weeks, and LH levels fell below the levels found in boys. This decrease was parallel to a steep increase in E2 levels (P < .001), and, from M4 to M6, LH and E2 correlated positively in PT girls (P < .01). T levels in PT boys increased earlier than E2 levels in PT girls. In addition, InhB levels were high in PT boys already at D7, in contrast to low InhB in PT girls. InhB and FSH correlated negatively in the whole group (P < .001)., Conclusions: Ovarian hormone synthesis is immature and incapable of responding to gonadotrophin stimulus before 38-42 PM weeks in PT girls, which may explain their highly elevated FSH and LH levels. The higher InhB levels in boys compared to girls may explain sexual dimorphism in FSH levels., (© 2018 John Wiley & Sons Ltd.)

Background: Feeding breast milk is associated with reduced morbidity and mortality, as well as improved neurodevelopmental outcome but does not meet the high nutritional requirements of preterm infants. Both plasma and urinary urea concentrations represent amino acid oxidation and low concentrations may indicate insufficient protein supply. This study assesses the effect of different levels of enteral protein on plasma and urinary urea concentrations and determines if the urinary urea-creatinine ratio provides reliable information about the protein status of preterm infants., Methods: Sixty preterm infants (birthweight < 1500 g; gestational age < 32 weeks) were enrolled in a randomized controlled trial and assigned to either a lower-protein group (median protein intake 3.7 g/kg/d) or a higher-protein group (median protein intake 4,3 g/kg/d). Half the patients in the higher-protein group received standardized supplementation with a supplement adding 1.8 g protein/100 ml milk, the other half received individual supplementation depending on the respective mother's milk macronutrient content. Plasma urea concentration was determined in two scheduled blood samples (BS1; BS2); urinary urea and creatinine concentrations in weekly spot urine samples., Results: The higher-protein group showed higher plasma urea concentrations in both BS1 and BS2 and a higher urinary urea-creatinine-ratio in week 3 and 5-7 compared to the lower-protein group. In addition, a highly positive correlation between plasma urea concentrations and the urinary urea-creatinine-ratio (p < 0.0001) and between actual protein intake and plasma urea concentrations and the urinary urea-creatinine-ratio (both p < 0.0001) was shown., Conclusions: The urinary urea-creatinine-ratio, just like plasma urea concentrations, may help to estimate actual protein supply, absorption and oxidation in preterm infants and, additionally, can be determined non-invasively. Further investigations are needed to determine reliable cut-off values of urinary urea concentrations to ensure appropriate protein intake., Trial Registration: Clinicaltrials.gov; NCT01773902 registered 15 January 2013, retrospectively registered.

Background: Nonspecific clinical signs and suboptimal diagnostic tests limit accurate identification of late onset sepsis (LOS) and necrotizing enterocolitis (NEC) in premature infants, resulting in significant morbidity and antibiotic overuse. An infant's systemic inflammatory response may be identified earlier than clinical suspicion through analysis of multiple vital signs by a computerized algorithm (RALIS)., Aim: To evaluate the revised RALIS algorithm for detection of LOS and NEC in preterm infants., Methods: In this nested case-control study, VS data (heart rate, respiratory rate, temperature, desaturations, bradycardias) were extracted from medical records of infants 23-32 weeks gestation. RALIS generated an output, with score ≥ 5 triggering an alert. Patient episodes were classified based on culture, radiograph, and antibiotic data into categories: LOS, expanded LOS, NEC, and controls. Paired t-tests, linear regression and cross-validation analyses were used to evaluate the relationship between RALIS alert and LOS/NEC., Results: Among 155 infants with 161 episodes, there were 41 expanded LOS (+blood, CSF, urine, respiratory culture), 31 LOS (+blood, CSF, urine), 9 NEC, and 93 controls. RALIS alert was 43.1 ± 79 h before culture in LOS (p = .012). There was a significant association between RALIS alert and LOS/NEC (β = 0.72, p < .0001). Sensitivity and specificity for LOS/NEC were 84% and 80%, (PPV = 63%; NPV = 93%). The regression model demonstrated an AUC of 89.9%., Conclusions: For infants ≤32 weeks, RALIS detects systemic inflammatory responses in LOS and NEC in the first month of life. The algorithm can identify infection earlier than clinical suspicion, even for NEC with negative cultures. RALIS has high NPV to rule-out LOS and NEC, and may, after prospective validation, aid in antibiotic treatment decisions., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Improving the management of neonatal diseases and prevention of chronic diseases in adulthood requires a better comprehension of the complex maturational processes associated with newborns' development. Urine-based metabolomic studies play a promising role in the fields of pediatrics and neonatology, relying on simple and noninvasive collection procedures while integrating a variety of factors such as genotype, nutritional state, lifestyle, and diseases. Here, we investigate the influence of age, weight, height, and gender on the urine metabolome during the first 4 months of life. Untargeted analysis of urine was carried out by 1 H-Nuclear Magnetic Resonance (NMR) spectroscopy for 90 newborns under 4 months of age, and free of metabolic, nephrologic, or urologic diseases. Supervised multivariate statistical analysis of the metabolic profiles revealed metabolites significantly associated with age, weight, and height, respectively. The tremendous growth occurring during the neonatal period is associated with specific modifications of newborns' metabolism. Conversely, gender appears to have no impact on the urine metabolome during early infancy. These results allow a deeper understanding of newborns' metabolic maturation and underline potential confounding factors in newborns' metabolomics studies. We emphasize the need to systematically and precisely report children age, height, and weight that impact urine metabolic profiles of infants.

Background: Neonatal acute kidney injury (AKI) is common and is associated with poor outcomes. New criteria for the diagnosis of AKI were introduced based on the increase in serum creatinine (SCr) levels and/or reduction of urine output (UOP). Yet, there is no generally accepted opinion so far, which criteria (whether SCr, UOP, or their combination) are the most appropriate to diagnose neonatal AKI., Methods: The retrospective study included 195 prematurely born neonates who fulfilled all inclusion criteria (with at least two SCr measurements). In all the neonates included in the study, AKI was diagnosed using three different definitions: (1) SCr criteria (an increase in SCr values of ≥0.3 mg/dl), (2) UOP criteria (UOP < 1.5 ml/kg/h), and (3) SCr + UOP criteria., Results: Out of all of the patients the study included, 85 (44%) were diagnosed with AKI. The neonates who had AKI had a significantly lower gestational age, birth weight, and Apgar score, longer duration of mechanical ventilation, and a higher mortality rate. SCr + UOP criteria showed higher sensitivity for prediction of death compared to SCr or UOP alone (p = 0.0008, 95% CI 0.040-0.154, and p = 0.0038, 95% CI 0.024-0.125, respectively). If only SCr or only UOP criterion are used, they fail to identify AKI in 61 and 67%, respectively. AKI was an independent risk factor for death (OR 7.4875; CI 3.1887-17.5816)., Conclusions: Similar to other studies, our data showed that neonates with AKI have worse outcome. Neonatal AKI defined based on SCr + UOP criteria is a better predictor of death than neonatal AKI defined based only on the SCr or UOP criteria. Also, by using SCr + UOP criteria for diagnosing neonatal AKI, more patients with AKI are recruited than when only one of those criteria is used.

Background: The number of nephrons at birth is determined during fetal development and is modulated thereafter by postnatal podocyte injury. Hyperfiltration, caused by a reduced number of nephrons, is a risk factor for chronic kidney disease. It is therefore important to monitor the formation of nephrons., Methods: Urine samples were collected from infants within 1-2 days of birth, with follow-up sampling for preterm infants at 37-39 weeks of corrected age. Urinary levels of podocalyxin (PCX), β2-microglobulin (β2MG), N-acetyl-ß-D-glucosaminidase (NAG), total protein (TP), microalbumin (mAlb) and creatinine were measured and the relationship between these markers evaluated., Results: Seventy-nine neonates were enrolled in this study. Urinary levels of PCX at birth were higher than normal adult reference values, with levels increasing up to a gestational age of 36 weeks (p = 0.0242). At 37-39 weeks corrected age, urinary levels of PCX decreased to adult levels. The levels of PCX in the urine at birth were not correlated to urinary levels of β2MG, NAG, TP and mAlb., Conclusions: An increased urinary level of PCX may be a marker of both active nephron formation and podocyte injury sustained at birth. As such, changes in urinary levels of PCX are likely to reflect adaptation of renal function to the extra-uterine environment.

Objective: The objective of this study was to estimate gonadotropin concentrations in small for gestational age (SGA) male infants with the reactivation of the hypothalamic-pituitary-gonadal axis during the first few months of life that is important for genital development., Study Design: We prospectively examined 15 SGA and 15 appropriate for gestational age (AGA) preterm male infants between 2013 and 2014 at Kyoto University Hospital. Gonadotropin concentrations (luteinizing hormone (LH) and follicle-stimulating hormone (FSH)) were measured in serial urine samples from the postnatal days 7 to 168 and compared between SGA and AGA infants using the Mann-Whitney test., Results: A longitudinal analysis showed that SGA infants had higher LH and lower FSH concentrations (P=0.004 and P=0.006, respectively) than AGA infants., Conclusion: Male infants who are SGA at birth because of fetal growth restriction have gonadotropin secretion abnormalities in the first few months of life.

Objective: To determine the incidence of intestinal mucosal injury before and after transfusions in premature infants., Study Design: Urine was collected throughout the hospital stay of 62 premature infants and specimens obtained within 24h before and after transfusion were assayed for intestinal fatty acid binding protein (iFABP). A urinary iFABP:creatinine ratio (iFABP u :Cr u ) of 2.0pg/nmol was considered elevated., Result: Forty-nine infants were transfused. iFABPu:Cru was elevated following 71 (75.6%) of 94 transfusions for which urine was available. In 51 (71.8%) of these, iFABPu:Cru was also elevated prior to the transfusion. Among four cases of transfusion-associated NEC, iFABP u was elevated following every sentinel transfusion and prior to three of them., Conclusion: Subclinical intestinal mucosal injury is frequent following blood transfusions in premature infants and, when present, usually precedes transfusion. This suggests that transfusion may not be a primary mediator of intestinal injury so much as anemia and its associated conditions., Level of Evidence: Prognosis study/level 3., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Few studies have investigated the association of environmental chromium exposure and preterm birth in general population. This study was designed to investigate whether maternal chromium exposure during pregnancy is associated with reduced gestational age or risk of preterm birth using the data from Healthy Baby Cohort study conducted in Hubei, China between 2012 and 2014 (n = 7290). Chromium concentrations in maternal urine samples collected at delivery were measured with inductively coupled plasma mass spectrometry. Tertiles of chromium concentrations was negatively associated with gestational age in multivariable linear regression analyses [β (95% CI): low = reference; middle = -0.67 days (-1.14, -0.20); high = -2.30 days (-2.93, -1.67); p trend <0.01]. Logistic regression analyses also indicated that higher maternal chromium [adjusted odds ratio (OR) (95% CI): 1.55(0.99, 2.42) for the medium tertile; 1.89(1.13, 3.18) for the highest tertile; p trend <0.01] was associated with increased risk of preterm birth. The associations appeared to be more pronounced in male infants (adjusted OR (95% CI): 2.54 (1.29, 4.95) for the medium tertile; 2.92 (1.37, 6.19) for the highest tertile; p trend <0.01). Our findings suggest maternal exposure to higher chromium levels during pregnancy may potentially increase the risk of delivering preterm infants, particularly for male infants.

Background: The club cell 10-kDa protein (CC10) is a homeostatic protein that is produced in the lung, diffuses into the blood, and is then excreted into the urine and stool. CC10 is known to have anti-inflammatory properties and to have lower endogenous production in preterm infants., Objectives: As recombinant human CC10 (rhCC10) is being studied in preterm infants to reduce lung injury, understanding CC10 levels in term infants with normal lungs is needed to establish appropriate target dosing ranges., Methods: Serum, urine, and stool samples were collected from 24 healthy full-term infants, and CC10 levels were measured. Levels in term infants were then compared to those in preterm infants who were examined in our previous studies., Results: The mean gestational age and birth weight of the term infants were 38.8 ±1.1 weeks and 3,257 ± 513 g, respectively. The mean gestational age of the preterm infants was 26.8 ± 1.4 weeks. The median serum [CC10] levels with minimum and maximum values in term infants (214.2 ng/mL [34.1, 428.1]) were >7-fold higher than in preterm infants (27.5 ng/mL [8.0, 760.0]; p < 0.05). A significant correlation was found between [CC10] in urine and stool as well as between gestational age and stool [CC10] (p < 0.05)., Conclusions: CC10 is detectable in serum, urine, and stool in healthy term infants, with levels significantly higher than in preterm infants. This provides important data for ongoing therapeutic intervention trials with rhCC10 in high-risk preterm infants., (© 2016 S. Karger AG, Basel.)

A serious problem during intensive care and nursing of premature infants is the invasiveness of many examination methods. Urine is an excellent source of potential biomarkers due to the safety of the collection procedure. The purpose of this study was to determine the features specific for the urine proteome of preterm newborns and their changes under respiratory pathologies of infectious and non-infectious origin. The urine proteome of 37 preterm neonates with respiratory diseases and 10 full-term newborns as a control group were investigated using the LC-MS/MS method. The total number of identified proteins and unique peptides was 813 and 3672 respectively. In order to further specify the defined infant-specific dataset these proteins were compared with urine proteome of healthy adults (11 men and 11 pregnant women) resulting in 94 proteins found only in infants. Pairwise analysis performed for label-free proteomic data revealed 36 proteins which reliably distinguished newborns with respiratory disorders of infectious genesis from those with non-infectious pathologies, including: proteins involved in cell adhesion (CDH-2,-5,-11, NCAM1, TRY1, DSG2), metabolism (LAMP1, AGRN, TPP1, GPX3, APOD, CUBN, IDH1), regulation of enzymatic activity (SERPINA4, VASN, GAPDH), inflammatory and stress response (CD55, CD 93, NGAL, HP, TNFR, LCN2, AGT, S100P, SERPINA1/C1/B1/F1)., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objective: To determine exposure to endocrine-disrupting phthalates in preterm infants in neonatal intensive care units (NICU)., Methods: Urine samples (n=151) from 36 preterm infants (<32 weeks of gestation and/or <1500 g of birth weight) were collected on the first 3 days of admission to the NICU and biweekly thereafter. Diethylhexyl phthalate contents of indwelling medical devices used in various procedures and the concentrations of phthalate metabolites in the urine samples were analyzed. The relationships between urinary excretion, exposure intensity, postnatal age and birth weight were examined., Results: The mean gestational age and mean birth weight of the study infants were 28.9±1.5 weeks and 1024±262 g, respectively. Diethylhexyl phthalate was detected in umbilical catheters, endotracheal tubes, nasogastric tubes, and nasal cannula. Monoethylhydroxyhexyl phthalate (MEHHP) was the most frequently detected metabolite (81.4%); its concentration increased during the first 4 weeks and then started to decrease but never disappeared. Patients who did not need indwelling catheters (except nasogastric tubes) after 2 weeks were classified as group 1 and those who continued to have indwelling catheters as group 2. Although not of statistical significance, MEHHP levels decreased in group 1 but continued to stay high in group 2 (in the 4th week, group 1: 65.9 ng/mL and group 2: 255.3 ng/mL). Levels of MEHHP in the first urinary samples were significantly higher in infants with a birth weight <1000 g (<1000 g: 63.2±93.8 ng/mL, ≥1000 g: 10.9±22.9 ng/mL, p=0.001)., Conclusion: Phthalate metabolites were detected even in the first urine samples of very low birth weight newborns. Phthalate levels were higher in the first weeks of intensive invasive procedures and in preterm infants with a birth weight less than 1000 g. MEHHP was the most frequently detected metabolite and could be a suitable biomarker for the detection of phthalate exposure in preterm infants.

Background: Urinary biomarkers may be indicators of acute kidney injury (AKI), although little is known of their developmental characteristics in healthy neonates across a full range of gestational age (GA). The purpose of this study was to examine patterns of urinary biomarkers across GA groups from birth to 3 months of age., Methods: Fifty-two infants ranging from 24 to 41 weeks' GA had urine assayed from birth through 3 months of age for 7 biomarkers including albumin (ALB), beta-2-microglobulin (B2M), cystatin-C (CysC), epidermal growth factor (EGF), neutrophil-gelatinase-associated lipocalin (NGAL), osteopontin (OPN), and uromodulin (UMOD)., Results: Of the seven urinary biomarkers, EGF and UMOD increased while others decreased with advancing GA. By 3 months of age, EGF and UMOD had increased in preterm infants to levels similar to those of term infants. UMOD/ml and EGF/ml appeared to be predominantly developmental biomarkers distinguishing estimated glomerular filtration rate (GFR) <30 ml/min/1.73 m(2) with receiver operator characteristic area under the curve (ROC-AUC) of 0.82; p = 0.002. When factored by urine creatinine CysC/cr + ALB/cr were the most significant functional markers with AUC = 0.79; p = 0.004; sensitivity 96 %; specificity 58 %., Conclusions: Among healthy neonates, urinary biomarkers vary with GA. These data support the use of urinary biomarkers in the assessment of normal kidney development in the absence of injury.

Germinal matrix intraventricular hemorrhage (IVH) is the most common type of intracranial hemorrhage observed in preterm neonates. It is a precursor of poor neurocognitive development, cerebral palsy, and death. The pathophysiology is not well defined, but damage to the fragile germinal matrix vasculature may be due to free radicals generated during inflammation and as a consequence of ischemia followed by reperfusion. Assessment of the oxidative stress status in these infants is therefore important. Urinary allantoin concentration was measured in preterm neonates as a marker of oxidative stress associated with IVH. Urine was collected from 44 preterm neonates at four time points between 24 and 72 hours of life (HOL), and the allantoin content was determined by gas chromatography mass spectrometry (GCMS). Records were retrospectively reviewed, and the incidence and severity of IVH was categorized as follows: no IVH (n = 24), mild (grade 1-2) IVH (n = 13), and severe (grade 3-4) IVH (n = 7). Neonates with severe IVH showed significantly elevated allantoin levels vs subjects with no IVH from 36 HOL (0.098 ± 0.013 μmol and 0.043 ± 0.007 μmol, respectively, p = 0.002). The allantoin concentration remained elevated even at 72 HOL (0.079 ± 0.014 μmol and 0.033 ± 0.008 μmol, respectively, p = 0.021). There were no significant differences in allantoin levels in the no IVH and mild IVH groups. IVH was diagnosed by head imaging on average at about 11th postnatal day. Urinary allantoin levels were significantly elevated during the first 3 days of life in the neonates subsequently diagnosed with severe IVH, suggesting that oxidative stress might be a crucial factor in IVH pathogenesis. Further studies are needed to assess the usefulness of urinary allantoin in early identification of preterm infants at risk for or with severe IVH and monitoring of the response to interventions designed to prevent or treat it.

Background: Human milk oligosaccharides (HMOs) shape the intestinal microbiota in term infants. In premature infants, alterations in the intestinal microbiota (dysbiosis) are associated with risk of necrotizing enterocolitis (NEC) and sepsis, and the influence of HMOs on the microbiota is unclear., Methods: Milk, urine, and stool specimens from 14 mother-premature infant dyads were investigated by mass spectrometry for HMO composition. The stools were analyzed by next-generation sequencing to complement a previous analysis., Results: Percentages of fucosylated and sialylated HMOs were highly variable between individuals but similar in urine, feces, and milk within dyads. Differences in urine and fecal HMO composition suggest variability in absorption. Secretor status of the mother correlated with the urine and fecal content of specific HMO structures. Trends toward higher levels of Proteobacteria and lower levels of Firmicutes were noted in premature infants of nonsecretor mothers. Specific HMO structures in the milk, urine, and feces were associated with alterations in fecal Proteobacteria and Firmicutes., Conclusion: HMOs may influence the intestinal microbiota in premature infants. Specific HMOs, for example those associated with secretor mothers, may have a protective effect by decreasing pathogens associated with sepsis and NEC, while other HMOs may increase dysbiosis in this population.

Background: Urine proteins may help in understanding physiology and diagnosing disease in premature infants. Determining how urine proteins vary by degree of prematurity, sex, and postnatal day is warranted., Methods: We performed a prospective cohort study to assess the independent correlation of 14 urine biomarkers (measured on postnatal days 1-4) with gestational age (GA), sex, and postnatal age in 81 premature infants (mean, 1017 g) without acute kidney injury using a random-effects mixed model., Results: Neutrophil gelatinase-associated lipocalin (NGAL) and vascular endothelial growth factor (VEGF) showed significant associations for sex, GA, and postnatal age. Cystatin C, osteopontin (OPN), and trefoil factor 3 (TFF3) were associated with postnatal age and GA, but not sex. Epithelial growth factor (EGF) and uromodulin were associated with GA only. Clusterin was associated with postnatal age and sex. Albumin was associated with sex only. Beta-2-microglbulin (B2M), osteoactivin, kidney injury molecule -1 (KIM-1), and alpha glutathione S-transferase (αGST) were associated with postnatal age only., Conclusions: Postnatal age affects B2M, cystatin C, NGAL, OPN, clusterin, Kim-1, osteoactivin, TFF3, VEGF, αGST. GA affects cystatin C, EGF, NGAL, OPN, UMOD, TFF3, and VEGF. Sex affects albumin, NGAL, and clusterin. Interpretation of urine biomarkers will need to account for these associations.

Preterm infants have an immature antioxidant system; however, they frequently require supplemental oxygen. Oxygen-free radicals cause both pulmonary and systemic inflammation, and they are associated with increased morbidity and mortality. Consequently, screening of metabolite profiles representing the amount of lipid peroxidation is considered of great relevance for the evaluation of in vivo oxidative stress and derived inflammation and damage. Ranges for total relative contents of isoprostanes (IsoPs), isofurans (IsoFs), neuroprostanes (NeuroPs), and neurofurans (NeuroFs) within targeted SpO2 ranges were determined in urine samples of 254 preterm infants<32 weeks of gestation within the frame of two randomized, controlled, and blinded clinical trials employing ultra-performance liquid chromatography-tandem mass spectrometry. A total of 536 serial urine samples collected during the first 4 weeks after birth in recruited infants who did not develop free radical associated conditions were analyzed. A reference range for lipid peroxidation byproducts, including isoprostanes, isofurans, neuroprostanes, and neurofurans, was calculated and possible correlations with neonatal conditions were investigated. Urinary elimination of isofurans in the first 4 days after birth correlated with later development of bronchopulmonary dysplasia. Our observations lead to the hypothesis that early urinary determination of lipid peroxidation byproducts, especially isofurans, is relevant to predict development of chronic lung conditions.

Objective: Immature antioxidant and oxygen-sensing mechanisms are involved in the pathogenesis of the patent ductus arteriosus (PDA). We conducted a prospective, observational, pilot study to test the hypothesis that antioxidant activity is low at birth in preterm infants at risk for symptomatic PDA., Study Design: Blood and urine samples were collected within 24 to 48 hours of life in 53 preterm infants (≤32 weeks' gestation) who developed early PDA symptoms and in 30 term (≥37 weeks' gestation) control infants. Thirty preterm infants developed hemodynamically significant PDA (hsPDA) and required pharmacologic treatment and/or PDA ligation. For these infants, blood and urine samples were also collected at 24 hours posttreatment. Samples were analyzed for biomarkers of antioxidant activity, oxidative stress, and lipid peroxidation., Results: At 24 to 48 hours after birth, plasma superoxide dismutase (SOD), urinary catalase, and plasma and urinary 8-isoPGF2α were significantly lower in preterm infants who developed hsPDA. Plasma 8-isoPGF2α levels rebounded post-PDA treatment, while urinary prostaglandin E2, plasma and urinary thromboxane B2, and plasma SOD declined., Conclusion: The antioxidant status is low in preterm infants at risk for developing hsPDA. SOD may be a key antioxidant regulating functional ductus arteriosus closure. Therefore, low levels may result in persistence of a hsPDA., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Background: Growing literature on negative childhood stress emphasizes the need to understand cortisol values from varying biomarker samples., Objective: This work aimed to examine cortisol samples for usability, associations, and individual stability in neonates., Subjects: The sample consisted of preterm infants (n=31)., Materials and Methods: Analyses on cortisol collected from cord blood and from saliva and urine samples on days 1, 7, and 14 included Spearman correlations and paired t-tests., Results: Usability rates were 80.6% (cord blood), 85.9% (saliva), and 93.5% (urine). Salivary and urinary cortisol levels had significant correlation on day 1 only (p=0.004). Significant differences in individual stability of cortisol concentrations existed except in urine on days 1 and 7 and in saliva on days 7 and 14., Conclusions: Usability was highest for urine samples. We found little correlation between cortisol sample levels at each time; individual stability of cortisol concentrations was minimal. Interpretation of cortisol findings in all studies should be performed cautiously.

Objective: To evaluate the usefulness of carboxyhemoglobin (CO-Hb) levels as a biomarker to predict the development and severity of bronchopulmonary dysplasia (BPD)., Methods: Twenty-five infants born at <33 wk of gestational age or with a birth weight of <1,500 g were enrolled. CO-Hb levels were measured between postnatal days 5 and 8, 12 and 15, 19 and 22, and 26 and 29. Urinary levels of 8-hydroxydeoxyguanosine (8-OHdG), advanced oxidation protein products, and Nε-(hexanoyl) lysine were measured between postnatal days 5 and 8 and 26 and 29. Receiver operating characteristic (ROC) analysis was used to compare the biomarkers' predictive values., Results: Compared with infants in the no-or-mild BPD group, infants with moderate-to-severe BPD exhibited higher CO-Hb levels during the early postnatal period and higher 8-OHdG levels between postnatal days 5 and 8. Using ROC analysis to predict the development of moderate-to-severe BPD, the area under the curve (AUC) for CO-Hb levels between postnatal days 5 and 8 was higher than AUCs for the urinary markers., Conclusions: CO-Hb levels during the early postnatal period may serve as a practical marker for evaluating oxidative stress and the severity of subsequently developing BPD.

Objective: To describe the blood level changes of mercury and lead after packed red blood cell (PRBC) transfusions in ≤ 750 g birth weight infants., Study Design: Heavy metal blood levels were measured in infants in PRBC units on 1st, 4th, 5th, and 7th days (D1, D4, D5, and D7) of life and in urine on D1, D4, and D7., Results: A total of 10 infants were enrolled with a mean birth weight of 632 ± 72 g. Out of which nine infants received one or more PRBC transfusions, with an average of 2.9 ± 2.5 transfusions per infant. Heavy metals were detected in all the transfusions. The average mercury level was 1.33 µg/L on D1 and 1.66 µg/L on D7, p > 0.05. The average lead level was 0.32 µg/dL on D1 and 0.56 µg/dL on D7, p > 0.05. Urinary mercury excretion increased in infants with no bowel movements. Urinary excretion of lead decreased over time as blood levels increased., Conclusions: After receiving blood transfusions, the blood levels of mercury and lead were maintained at the end of the 1st week of life. As there is no evidence of a proportionate increase in excretory amounts of these heavy metals, there is a concern that they are retained and potentially exert toxic effects., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Objective: To assess bone status in preterm infants with quantitative ultrasound and to search for biochemical markers of bone health., Methods: Metacarpus bone transmission time (mcBTT) was prospectively performed during hospitalization, together with biochemical and clinical outcomes analysis., Results: 154 patients were studied. At 3rd week of life mcBTT positively correlated with serum phosphate. Urinary excretion of calcium and phosphate were assessed in a subgroup of 55 patients: on day 21 mcBTT positively correlated with phosphaturia, negatively with calciuria. Gestational age (GA), weight and length at 3rd week and at 36 weeks of GA correlated positively with mcBTT. We found negative correlation between mcBTT at 3rd week and days of parenteral nutrition, mechanical ventilation period and days to reach 1800 g., Conclusions: Serum phosphate, phosphaturia and calciuria correlate most with mcBTT. Further studies are necessary to verify the possible influence of early bone status on future bone health.

Background: Some phthalates have shown antiandrogenic effects in rat offspring. Premature infants may be exposed to high amounts of specific phthalates during hospitalization, and thus are potentially at risk., Objective: We evaluated longitudinal phthalate exposure and metabolism in full-term (FT) and preterm (PT) infants., Methods: Fifty-eight FT and 67 PT (gestational age, 24.7-36.6 weeks) infants were recruited at birth and followed until 14 months (nine times). Urinary concentrations of metabolites of diethyl phthalate (DEP), dibutyl phthalate isomers (DiBP and DnBP), butylbenzyl phthalate (BBzP), di(2-ethylhexyl) phthalate (DEHP), and diisononyl phthalate (DiNP) were measured in 894 samples. Daily intake and a hazard index for antiandrogenic effects were estimated, and excretion patterns of DEHP and DiNP metabolites were analyzed., Results: Metabolites of BBzP, DiNP, and DEHP were 5-50 times higher at day 7 (D7) and month 1 (M1) in PT than in FT infants. Thereafter, metabolite concentrations were similar between the two groups. The estimated hazard index for combined DiBP, DnBP, BBzP, and DEHP exposures 7 days after birth exceeded the antiandrogenic threshold in > 80% of PT and > 30% of FT infants, and after M2, in 30% of all infants. The excretion pattern of DEHP and DiNP metabolites changed with age., Conclusion: Most PT infants and approximately one-third of healthy FT newborns were exposed to phthalates during early life at a potentially harmful level according to the European Food Safety Authority's recommended limits of daily exposure. Changes in the relative proportions of secondary phthalate metabolites over time were consistent with maturation of infant metabolic pathways during the first year of life. Further research is needed on the health effects of phthalate exposures and the influence of changes in metabolic capacity in neonates and infants.

Objectives: Premature babies require supplementation with calcium (Ca) and phosphorus (P) to prevent metabolic bone disease of prematurity. To guide mineral supplementation, 2 methods of monitoring urinary excretion of Ca and P are used: urinary Ca or P concentration and Ca/creatinine (Crea) or P/Crea ratios. We compare these 2 methods in regards to their agreement on the need for mineral supplementation., Methods: Retrospective chart review of 230 premature babies with birth weight <1500 g, undergoing screening of urinary spot samples from day 21 of life and fortnightly thereafter. Hypothetical cutoff values for urine Ca or P concentration (1 mmol/L) and urine Ca/Crea ratio (0.5 mol/mol) or P/Crea ratio (4 mol/mol) were applied to the sample results. The agreement on whether to supplement the respective minerals based on the results with the 2 methods was compared. Multivariate general linear models sought to identify patient characteristics to predict discordant results., Results: A total of 24.8% of cases did not agree on the indication for Ca supplementation, and 8.8% for P. Total daily Ca intake was the only patient characteristic associated with discordant results., Conclusions: With the intention to supplement the respective mineral, comparison of urinary mineral concentration with mineral/Crea ratio is moderate for Ca and good for P. The results do not allow identifying superiority of either method on the decision as to which babies require Ca and/or P supplements.

Background: Necrotizing enterocolitis (NEC) is diagnosed after the development of feeding intolerance and characteristic physical and imaging findings. Earlier detection of a subclinical prodrome might allow for the institution of measures that could prevent or attenuate the severity of the disease., Objectives: We sought to determine whether urinary intestinal fatty acid-binding protein (iFABPu) might be elevated prior to the first clinical manifestations of NEC., Methods: Urine was collected daily from 62 infants of a gestational age of 24-28 weeks. Based on clinical, imaging and operative findings, subjects were determined to have Bell stage 2 or 3 NEC. In all the subjects with NEC and in 21 age-matched controls, iFABPu was determined using an ELISA, and was expressed in terms of its ratio to urinary creatinine (Cr), i.e. iFABPu/Cru. Receiver operating characteristic (ROC) curves were constructed to define the predictive value of iFABPu/Cru for impending NEC in the days prior to the first clinical manifestations., Results: Five subjects developed NEC (stage 2: n = 3 and stage 3: n = 2). The day before the first clinical manifestation of NEC, a ROC curve showed that an iFABPu/Cru >10.2 pg/nmol predicted impending NEC with a sensitivity of 100% and a specificity of 95.6%. iFABPu/Cru did not predict NEC 2 days prior to the first sign of disease., Conclusions: An elevated iFABPu was a sensitive and specific predictor of impending NEC 1 day prior to the first clinical manifestations. iFABPu screening might identify infants at a high risk and allow for the institution of measures that could ameliorate or prevent NEC., (© 2014 S. Karger AG, Basel.)

Background: The aim of this study is to determine the reference values of urinary neutrophil gelatinase-associated lipocalin (uNGAL) in healthy very preterm infants., Method: The study was performed on 30 preterm infants whose gestational ages (GA) were between 28 and 34 weeks. They were divided into three groups according to the GA as group 1: GA 28-29 weeks, group 2: 30-32 weeks and group 3: 33-34 weeks. Blood and urine samples were obtained on postnatal (PN) days 1 and 7. uNGAL was measured by ELISA., Results: There were 10 preterm infants for each group. The median values of uNGAL on PN Days 1 were 19.80 (8.6-25.7) ng/ml, 9.25 (1.42-30.3) ng/ml, and 7.95 (1.60-27.8) ng/ml in group 1, group 2 and group 3, respectively. Multivariate linear regression analysis showed that uNGAL values are not associated with GA, birth weight, and gender in preterm infants on PN Days 1 and 7., Conclusion: Our study indicated that normal values of uNGAL concentrations in healthy very preterm infants, and older children or adults are similar preterm infants.