S100 A8/A9 protein as a marker for early diagnosis of necrotising enterocolitis in neonates

Fecal calprotectin as a non-invasive marker for the prediction of post-necrotizing enterocolitis stricture

PURPOSE

This study aimed to evaluate the clinical utility of fecal calprotectin (FC) levels during the necrotizing enterocolitis (NEC) episode to predict the onset of post-NEC intestinal stricture.

METHODS

The medical records of patients with NEC treated from April 2020 to April 2022 were recorded for this study. FC was quantified at the acute phase of NEC. FC levels were compared in patients with or without intestinal stricture. Receiver operating characteristics (ROC) analysis was constructed to determine optimal cut-offs of FC for post-NEC intestinal stricture.

RESULTS

A total of 50 infants with NEC were enrolled in this study and 14 (28%) of them eventually developed intestinal stricture. All children with intestinal stricture underwent one-stage surgery and all made it through the follow-up period alive. The median FC level was 1237.55 (741.25, 1378.80) ug/g in patients with intestinal stricture and it was significantly higher than that in the non-stricture group [158.30 (76.23, 349.13) ug/g, P < 0.001]. FC had good diagnostic accuracy for predicting intestinal stricture, according to ROC curve analysis, with an AUC area of 0.911. At an optimal cut-off value of 664.2 ug/g, sensitivity and specificity were 85.71% and 91.67%, respectively.

CONCLUSION

As a non-invasive parameter, FC has excellent efficacy and accuracy in predicting post-NEC intestinal stricture. Increased FC levels at the acute phase of NEC were associated with the development of intestinal stricture.

Novel insights into plasma biomarker candidates in patients with chronic mountain sickness based on proteomics

Chronic mountain sickness (CMS) is a progressive incapacitating syndrome induced by lifelong exposure to hypoxia. In the present study, proteomic analysis was used to identify the differentially expressed proteins (DEPs) and then evaluate the potential plasma biomarkers between CMS and non-CMS groups. A total of 145 DEPs were detected in CMS Han Chinese people who live in the plateau (CMS-HPu), among which 89 were significantly up-regulated and 56 were significantly down-regulated. GO enrichment analysis showed that various biological processes were enriched, including the hydrogen peroxide metabolic/catabolic process, reactive oxygen species (ROS) metabolic, and acute inflammatory response. Protein–protein interaction analysis showed that antioxidant activity, the hydrogen peroxide catabolic process and peroxidase activity were primarily mapped in interaction proteins. Nine modules showed significantly clustering based on WGCNA analysis, with two being the most significant, and GO analysis showed that proteins of both modules were primarily enriched in oxidative stress-related biological processes. Four DEPs increased in CMS patients were evaluated as the candidate biomarkers, and three showed significant AUC: hemoglobin β chain (HB-β), thioredoxin-1 (TRX1), and phosphoglycerate kinase 1 (PGK1). The present study provides insights into the pathogenesis of CMS and further evaluates the potentially biomarkers for its prevention and treatment of it.

Antibody Microarray Analysis of Plasma Proteins for the Prediction of Histologic Chorioamnionitis in Women With Preterm Premature Rupture of Membranes

We aimed to identify maternal blood biomarkers predictive of histologic chorioamnionitis (HCA) in the plasma of women with preterm premature rupture of membranes (PPROM) and to determine whether the combination of these biomarkers with conventional clinical variables can improve the prediction of HCA. This retrospective cohort study included 82 consecutive women with PPROM (23-34 gestational weeks) who delivered within 96 hours of blood sampling. A membrane-based human antibody microarray was used to analyze the plasma proteome. The validation of 5 candidate biomarkers of interest was performed by enzyme-linked immunosorbent assay (ELISA) in the final cohort (n = 82). Serum C-reactive protein (CRP) levels were measured at sampling. Seventy-nine molecules studied exhibited intergroup differences. Validation by ELISA confirmed higher levels of plasma matrix metalloproteinase-9 (MMP-9), interleukin-6 (IL-6), S100 A8/A9, and insulin-like growth factor-binding protein 1 (IGFBP-1), but not tissue inhibitor of metalloproteinase 1 (TIMP-1), in women with HCA than in women without HCA. Using a stepwise regression analysis, a combined prediction model was developed, which included the plasma MMP-9, serum CRP levels, and gestational age (area under the curve [AUC], 0.932). The AUC for this model was significantly greater than that for any single variable included in the predictive model. Protein-antibody microarray technology can be useful in identifying plasma-based predictors for HCA. This study suggests that plasma MMP-9, IL-6, IGFBP-1, and S100 A8/A9 are important noninvasive predictors for HCA in women with PPROM and that the best predictive model, which combined these biomarkers with conventional clinical factors, can significantly improve the predictability for HCA.

Immune biomarkers in maternal plasma to identify histologic chorioamnionitis in women with preterm labor

PURPOSE

To determine whether various selected immune-related proteins in maternal plasma, alone or in combination, can predict histologic chorioamnionitis (HCA) in women with preterm labor, and to compare the predictive abilities of these biomarkers with that of serum C-reactive protein (CRP).

METHODS

This retrospective cohort study included 74 consecutive women with preterm labor (23-34 gestational weeks) who delivered within 96 h of blood sampling. Their serum CRP levels were also measured. The stored maternal plasma was assayed for interleukin (IL)-6, matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinases (TIMP)-1, angiopoietin-2, S100 A8/A9, CXCL14, APRIL, and insulin-like growth factor-binding protein-2 (IGFBP-2), using ELISA kits. The primary outcome measure was HCA.

RESULTS

HCA was detected in 59.4% (44/74) of women. Women with HCA had a significantly lower median gestational age at sampling and plasma IGFBP-2 level, and higher median plasma IL-6 and S100 A8/A9 levels than those without HCA. In multivariable analysis, high plasma IL-6 and low plasma IGFBP-2 levels were independently associated with the occurrence of HCA. However, the sensitivities, specificities, and areas under the curve of plasma IL-6, S100 A8/A9, and IGFBP-2, alone or in combination, were similar to or lower than those of serum CRP, for detecting HCA.

CONCLUSIONS

Our data suggest that plasma IL-6, S100 A8/A9, and IGFBP-2 could be potential novel biomarkers for predicting HCA in women with PTL; however, elevated plasma levels of these biomarkers, alone or in combination, do not predict HCA better than serum CRP.

Serum Markers of Necrotizing Enterocolitis: A Systematic Review

OBJECTIVE

The aim of the study was to systematically review the diagnostic utility of serum biomarkers for the diagnosis of necrotizing enterocolitis (NEC).

METHODS

We conducted an electronic and manual search of the available evidence. We included studies reporting data on the diagnostic accuracy of "serum" biomarkers for the diagnosis of NEC, available until January 2016.

RESULTS

We selected 22 studies from the 1296 articles retrieved. Only S100 A8/A9 protein and apolipoprotein-CII showed high sensitivity (100% and 96.4%, respectively) and specificity (90% and 95%, respectively) in the studies using Bell stage II NEC as target condition. High sensitivity and specificity were reported for interleukin-10 (100% and 90%), interleukin1-receptor antagonist (100% and 91.7%), intestinal fatty acid-binding protein (100% and 91%) and ischemia-modified albumin (94.7% and 92%), when tested to predict the evolution from definite to advanced NEC. Given the amount of uncertainty, the limited availability of data and heterogeneity among the populations in the different studies, we were unable to perform a meta-analysis. Major concerns about the applicability stemmed from the spectrum of patients enrolled and the inclusion of diseases different from Bell stage ≥2 NEC as target conditions.

CONCLUSIONS

We identified only few markers with good diagnostic accuracy and found an overall low quality of the studies on serum NEC biomarkers. In conclusion, data supporting their use are insufficient.

Calprotectin levels in necrotizing enterocolitis: a systematic review of the literature

BACKGROUND

Fecal calprotectin has been extensively investigated as a screening marker for the detection of necrotizing enterocolitis (NEC). However, there is a complete lack of consensus regarding its efficacy as a diagnostic test.

OBJECTIVE

The purpose of the present systematic review is to evaluate the effectiveness of fecal calprotectin as a screening marker for the detection of NEC.

MATERIALS AND METHODS

We conducted a systematic review of studies published in the Medline (1966-2016), Scopus (2004-2016), ClinicalTrials.gov (2008-2016), Cochrane Central Register of Controlled Trials CENTRAL (1999-2016), and Google Scholar (2004-2016) databases, combined with studies found in the reference lists of the included studies. All prospective and retrospective observational cohort studies were included.

RESULTS

Thirteen studies that included 601 neonates were identified in the international literature. The presence and severity of NEC was evaluated with the modified Bell's criteria. Ten studies found significantly elevated fecal calprotectin levels among infants with NEC (p < 0.05). One study found that this effect was observed irrespective of the stage of the disease. Five studies evaluated the efficacy of fecal calprotectin as a diagnostic test. The reported sensitivity ranged between 76 and 100 %, and the specificity varied from 39 to 96.4 %. However, the proposed cut-off values were not similar.

CONCLUSION

Current evidence suggests that fecal calprotectin is elevated in newborns suffering from NEC. However, its significance as an early screening marker remains unknown. Future studies are needed and should focus on the identification of specific cut-off values.

Clinical significance of FABP2 expression in newborns with necrotizing enterocolitis

BACKGROUND

This meta-analysis aimed to determine the role of human fatty acid binding protein 2 (FABP2) expression in the diagnosis of necrotizing enterocolitis (NEC) of newborns.

DATA SOURCES

Eligible studies for further statistical analysis were identified from various databases including PubMed, Expert Medica Database, Web of Science, Cochrane Library, Google Scholar, China BioMedicine and China National Knowledge Infrastructure. Random effects model was used, and summary standardized mean difference (SMD) with its 95% confidence interval (CI) was calculated to assess the association of FABP2 expression and NEC.

RESULTS

Ten articles which included 572 infants (262 infants with NEC and 310 healthy controls) were included in the current meta-analysis. FABP2 showed a positive relationship with NEC of newborns (SMD=2.88, 95% CI=2.09-3.67, P<0.001). And FABP2 expression was higher in patients with advanced stage of NEC (stage III or stage II+III) than in those with early stage of NEC (stage I) (SMD=-0.48, 95% CI=-0.87 to -0.09, P=0.015). Ethnicity-stratified analysis yielded significantly different estimates with a high FABP2 expression in NEC in both Caucasians (SMD=3.16, 95% CI=1.90-4.43, P<0.001) and Asians (SMD=2.57, 95% CI=1.50-3.64, P<0.001). Sample-based subgroup analysis showed that FABP2 expression was positively correlated with neonatal NEC in both urinary- and blood-sample subgroups (all P<0.05).

CONCLUSION

The results prove that the high FABP2 expression is related to the damage to intestinal cells, which may be a possible early detection marker identifying neonatal NEC.

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

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

Delayed initiation but not gradual advancement of enteral formula feeding reduces the incidence of necrotizing enterocolitis (NEC) in preterm pigs

Enteral formula feeding is a risk factor for necrotizing enterocolitis (NEC) in premature infants, yet studies are conflicting regarding the safest timing for introduction and advancement of feeds. Our aim was to test the effects of early vs. late initiation and abrupt vs. gradual advancement of enteral feeding of an intact vs. hydrolyzed protein formula on NEC incidence and severity in preterm pigs. In Experiment 1, preterm pigs received total parenteral nutrition (TPN) at birth with abrupt initiation of enteral formula feeds (50% full intake) on d of life (DOL) 2 (EA) or 5 (LA) while PN continued. Pigs were also fed formula containing either intact or hydrolyzed protein. In Experiment 2, preterm pigs received TPN at birth with enteral, hydrolyzed-protein formula feeds introduced on DOL 2 either abruptly (EA; 50% full feeds) or gradually (EG; 10-50% full feeds over 5 d) while PN continued. NEC incidence and severity were assessed based on macroscopic and histological scoring. In Experiment 1, NEC incidence (41% vs. 70%, P<0.05) and severity were reduced in LA vs. EA groups and LA was associated with a higher survival rate, daily weight gain and jejunum villus height. Piglets fed hydrolyzed vs. intact protein formula had lower stomach content weights and similar NEC incidence. In Experiment 2, NEC incidence and severity were not different between pigs the EG vs. EA group. Proinflammatory gene expression (IL-1β, IL-6 and S100A9) in the ileum was lower in both LA and EG vs. EA groups. In conclusion, delayed initiation but not gradual advancement of enteral feeding is protective against NEC in preterm pigs. Feeding hydrolyzed vs. intact protein formula improved gastric transit without affecting the NEC incidence.

Proteomics-Based Identification of Differentially Abundant Proteins from Human Keratinocytes Exposed to Arsenic Trioxide

INTRODUCTION

Arsenic is a widely distributed environmental toxicant that can cause multi-tissue pathologies. Proteomic assays allow for the identification of biological processes modulated by arsenic in diverse tissue types.

METHOD

The altered abundance of proteins from HaCaT human keratinocyte cell line exposed to arsenic was quantified using a label-free LC-MS/MS mass spectrometry workflow. Selected proteomics results were validated using western blot and RT-PCR. A functional annotation analytics strategy that included visual analytical integration of heterogeneous data sets was developed to elucidate functional categories. The annotations integrated were mainly tissue localization, biological process and gene family.

RESULT

The abundance of 173 proteins was altered in keratinocytes exposed to arsenic; in which 96 proteins had increased abundance while 77 proteins had decreased abundance. These proteins were also classified into 69 Gene Ontology biological process terms. The increased abundance of transferrin receptor protein (TFRC) was validated and also annotated to participate in response to hypoxia. A total of 33 proteins (11 increased abundance and 22 decreased abundance) were associated with 18 metabolic process terms. The Glutamate--cysteine ligase catalytic subunit (GCLC), the only protein annotated with the term sulfur amino acid metabolism process, had increased abundance while succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial precursor (SDHB), a tumor suppressor, had decreased abundance.

CONCLUSION

A list of 173 differentially abundant proteins in response to arsenic trioxide was grouped using three major functional annotations covering tissue localization, biological process and protein families. A possible explanation for hyperpigmentation pathologies observed in arsenic toxicity is that arsenic exposure leads to increased iron uptake in the normally hypoxic human skin. The proteins mapped to metabolic process terms and differentially abundant are candidates for evaluating metabolic pathways perturbed by arsenicals.

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.

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.

The role of calprotectin in pediatric disease

Calprotectin (CP) is a calcium- and zinc-binding protein of the S100 family expressed mainly by neutrophils with important extracellular activity. The aim of the current review is to summarize the latest findings concerning the role of CP in a diverse range of inflammatory and noninflammatory conditions among children. Increasing evidence suggests the implication of CP in the diagnosis, followup, assessment of relapses, and response to treatment in pediatric pathological conditions, such as inflammatory bowel disease, necrotizing enterocolitis, celiac disease, intestinal cystic fibrosis, acute appendicitis, juvenile idiopathic arthritis, Kawasaki disease, polymyositis-dermatomyositis, glomerulonephritis, IgA nephropathy, malaria, HIV infection, hyperzincemia and hypercalprotectinemia, and cancer. Further studies are required to provide insights into the actual role of CP in these pathological processes in pediatrics.