Diagnostic tests in neonatal sepsis:

Inflammatory biomarkers and physiomarkers of late-onset sepsis and necrotizing enterocolitis in premature infants

Background

Early diagnosis of late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) in very low birth weight (VLBW, <1,500 g) infants is challenging due to non-specific clinical signs. Inflammatory biomarkers increase in response to infection, but non-infectious conditions also cause inflammation. Cardiorespiratory data contain physiological biomarkers, or physiomarkers, of sepsis that may be useful in combination with inflammatory hematologic biomarkers for sepsis diagnosis.

Objectives

To determine whether inflammatory biomarkers measured at the time of LOS or NEC diagnosis differ from times without infection and whether biomarkers correlate with cardiorespiratory sepsis physiomarkers in VLBW infants.

Methods

Remnant plasma sample collection from VLBW infants occurred with blood draws for routine laboratory testing and suspected sepsis. We analyzed 11 inflammatory biomarkers and a pulse oximetry sepsis warning score (POWS). We compared biomarker levels obtained at the time of gram-negative (GN) bacteremia or NEC, gram-positive (GP) bacteremia, negative blood cultures, and no suspected infection.

Results

We analyzed 188 samples in 54 VLBW infants. Several biomarkers were increased at the time of GN LOS or NEC diagnosis compared with all other samples. POWS was higher in patients with LOS and correlated with five biomarkers. IL-6 had 78% specificity at 100% sensitivity to detect GN LOS or NEC and added information to POWS.

Conclusions

Inflammatory plasma biomarkers discriminate sepsis due to GN bacteremia or NEC and correlate with cardiorespiratory physiomarkers.

Diagnostic Utility of Interleukin-6 in Early-Onset Sepsis among Term Newborns: Impact of Maternal Risk Factors and CRP Evaluation

(1) Background: Interleukin-6 (IL-6) levels act as an early infection marker preceding C-reactive protein (CRP) elevation. This study seeks to analyze IL-6 behavior in suspected early-onset sepsis (EOS) cases among term newborns, comparing it to that of CRP and evaluating IL-6's diagnostic utility. We also aim to assess the impact of maternal risk factors on EOS in term newborns, quantifying their influence for informed decision making. (2) Methods: The retrospective data analysis included 533 term newborns who were admitted to our hospital because of suspected EOS. IL-6, CRP, and the impact of maternal risk factors were analyzed in the context of EOS using binomial test, Chi-squared test, logistic and linear regression. (3) Results: In the cases of EOS, both IL-6 and CRP were elevated. The increase in CRP can be predicted by the initial increase in IL-6 levels. Among the assessed risk factors, intrapartum maternal fever (adjusted odds ratio 18.1; 95% CI (1.7-4.1)) was identified as the only risk factor significantly associated with EOS. (4) Conclusions: Employing IL-6 as an early infection marker enhanced EOS diagnostic precision due to its detectable early rise. However, caution is required, as elevations in IL-6 and CRP levels do not exclusively indicate EOS. Increased CRP levels in healthy newborns with maternal risk factors may be attributed to dynamics of vaginal labor.

Insight Into Neonatal Sepsis: An Overview

There are approximately 1.3 million cases of neonatal sepsis reported worldwide with deaths occurring more commonly in preterm and low-weight newborns. Neonatal sepsis is the third major cause of neonatal deaths resulting in 203,000 deaths per year. It is divided into two subtypes based on time of occurrence: early-onset neonatal sepsis (ENS), occurring within the first 72 hours of birth usually due to perinatal risk factors, and late-onset neonatal sepsis (LOS) usually occurring after the first week of life and up to 28th day of life. There are many complications associated with neonatal sepsis including septic shock, multiple organ failure, and death. It is vital for clinicians to know the signs and symptoms of neonatal sepsis in order to diagnose it early. Preventive measures, early diagnosis, appropriate antibiotic administration, timely supportive management, and the establishment of efficient management are vital in the prevention of severe complications or death. In this review, we aim to provide the most up-to-date information regarding risk factors, pathophysiology, signs and symptoms, diagnosis, and treatment of neonatal sepsis. We discuss the maternal and neonatal risk factors involved in the pathogenesis of neonatal sepsis and the signs and symptoms of early and late neonatal sepsis. We focus on the different pathogens involved and the markers used in the diagnosis and treatments available for each.

Inflammatory Biomarkers and Physiomarkers of Late-Onset Sepsis and Necrotizing Enterocolitis in Premature Infants

Background

Early diagnosis of late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) in VLBW (<1500g) infants is challenging due to non-specific clinical signs. Inflammatory biomarkers increase in response to infection, but non-infectious conditions also cause inflammation in premature infants. Physiomarkers of sepsis exist in cardiorespiratory data and may be useful in combination with biomarkers for early diagnosis.

Objectives

To determine whether inflammatory biomarkers at LOS or NEC diagnosis differ from times without infection, and whether biomarkers correlate with a cardiorespiratory physiomarker score.

Methods

We collected remnant plasma samples and clinical data from VLBW infants. Sample collection occurred with blood draws for routine laboratory testing and blood draws for suspected sepsis. We analyzed 11 inflammatory biomarkers and a continuous cardiorespiratory monitoring (POWS) score. We compared biomarkers at gram-negative (GN) bacteremia or NEC, gram-positive (GP) bacteremia, negative blood cultures, and routine samples.

Results

We analyzed 188 samples in 54 VLBW infants. Biomarker levels varied widely, even at routine laboratory testing. Several biomarkers were increased at the time of GN LOS or NEC diagnosis compared with all other samples. POWS was higher in patients with LOS and correlated with five biomarkers. IL-6 had 78% specificity at 100% sensitivity to detect GN LOS or NEC and added information to POWS (AUC POWS = 0.610, POWS + IL-6 = 0.680).

Conclusions

Inflammatory biomarkers discriminate sepsis due to GN bacteremia or NEC and correlate with cardiorespiratory physiomarkers. Baseline biomarkers did not differ from times of GP bacteremia diagnosis or negative blood cultures.

Biomarkers and their Clinical Applications in Pediatrics

Biomarker studies are becoming increasingly interesting for many fields of medicine. The use of biomarkers in medicine is involved in detecting diseases and supporting diagnosis and treatment decisions. New research and new discoveries on the molecular basis of the disease show that there may be a number of promising new biomarkers for use in daily clinical practice. Clinical trials in children lag behind adult research both in quality and quantity. The number of biomarkers validated to optimize pediatric patient management is limited. In the pathogenesis of many diseases, it should not be extrapolated to the pediatric clinical setting, taking into account that biomarkers that are effective in adults are clearly different in children and that ontogeny directly affects disease development and therapeutic response in children. The search for ideal biomarkers or markers that can make an early and definitive diagnosis in neonatal sepsis is still ongoing. The ideal biomarker for pediatric diseases should be costeffective, noninvasive, applicable to pediatric specific diseases, and its results should correspond to age-related physiological changes. Lactate, troponin and B-type natriuretic peptide are valuable biomarkers in the evaluation and management of critically ill children with cardiac disease. Tumor markers in children are biochemical substances used in the clinical treatment of pediatric tumors and to detect the presence of cancer (regression or progression). In this chapter, current and brief information about biomarkers and their clinical applications used in the diagnosis and monitoring of pediatric diseases is presented.;

Biomarkers of sepsis in pigs, horses and cattle: from acute phase proteins to procalcitonin

Sepsis is a complex clinical syndrome triggered by an inflammatory host response to an infection. It is usually complicated to detect and diagnose, and has severe consequences in human and veterinary health, especially when treatment is not started early. Therefore, efforts to detect sepsis accurately are needed. In addition, its proper diagnosis could reduce the misuse of antibiotics, which is essential fighting against antimicrobial resistance. This case is a particular issue in farm animals, as antibiotics have been traditionally given massively, but now they are becoming increasingly restricted. When sepsis is suspected in animals, the most frequently used biomarkers are acute phase proteins such as C-reactive protein, serum amyloid A and haptoglobin, but their concentrations can increase in other inflammatory conditions. In human patients, the most promising biomarkers to detect sepsis are currently procalcitonin and presepsin, and there is a wide range of other biomarkers under study. However, there is little information on the application of these biomarkers in veterinary species. This review aims to describe the general concepts of sepsis and the current knowledge about the biomarkers of sepsis in pigs, horses, and cattle and to discuss possible advances in the field.

Diagnostic accuracy of red blood cell distribution width for neonatal sepsis

INTRODUCTION

Red blood cell distribution width (RDW) is a biomarker for the diagnosis and prognosis of many diseases. However, the relevance between RDW and neonatal sepsis (NS) have not reached a consensus yet; the perform of RDW in the diagnosis of neonatal sepsis is still not clear. The aim of this meta-analysis was to estimate the significance of RDW in neonatal sepsis and the perform of RDW in diagnosis of neonatal sepsis.

EVIDENCE ACQUISITION

We used Pubmed, Embase, Web of science, CNKI and Google academic database to find all articles that met the inclusion criteria until July 1, 2020.

EVIDENCE SYNTHESIS

Fifteen eligible studies involving 1362 newborns were included in the meta-analysis after two independent investigators read the title, abstract and full text in detail. The pooled result of this meta-analysis showed that RDW was significantly higher in the NS group than in the control group (WMD=3.224; 95%CI: 2.359-4.090, P<0.001). In addition, the overall pooled sensitivity, specificity, PLR, NLR and DOR were 0.88 (95%CI:0.66-0.96), 0.90 (95%CI:0.65-0.98), 9.2 (95%CI:2.1-40.3), 0.14(95%CI:0.04-0.43) and 66.9 (95%CI:8.73-513.26), respectively. The area under the SROC curve (AUC) was 0.95 (95%CI:0.93-0.96).

CONCLUSIONS

The meta-analysis demonstrated that newborns with sepsis had an elevated RDW level than healthy controls. RDW levels have significant correlated with neonatal sepsis; and RDW can be used as a cheap and satisfactory diagnostic biomarker for neonatal sepsis with a relatively high performance.

Biomarkers of Neonatal Sepsis: From Being Mere Numbers to Becoming Guiding Diagnostics

Neonatal sepsis is a common cause of neonatal morbidity and mortality. The diagnosis of newborn sepsis is still difficult. Different early objective diagnostic tests or specific signs and symptoms, particularly in preterm infants, make it difficult to diagnose neonatal sepsis. This review article describes biomarkers and their role in the early diagnosis, treatment, and prognosis of neonatal sepsis. It also explores the possible advances and future prospects of these biomarkers. An ideal sepsis biomarker will not only help in the guidance of the use of antibiotics when not needed but also the duration of the course of antibiotics if sepsis is proven. It should also have high sensitivity, specificity, positive predictive value, and negative predictive value. These biomarkers hold a promising position in the management of neonatal sepsis and translate into use in clinical settings. Metabolomics, a diagnostic method based on detecting metabolites found in biological fluids, may open new possibilities in the management of critically ill newborns.

Diagnosis of neonatal sepsis: the past, present and future

Sepsis remains a significant cause of neonatal mortality and morbidity, especially in low- and middle-income countries. Neonatal sepsis presents with nonspecific signs and symptoms that necessitate tests to confirm the diagnosis. Early and accurate diagnosis of infection will improve clinical outcomes and decrease the overuse of antibiotics. Current diagnostic methods rely on conventional culture methods, which is time-consuming, and may delay critical therapeutic decisions. Nonculture-based techniques including molecular methods and mass spectrometry may overcome some of the limitations seen with culture-based techniques. Biomarkers including hematological indices, cell adhesion molecules, interleukins, and acute-phase reactants have been used for the diagnosis of neonatal sepsis. In this review, we examine past and current microbiological techniques, hematological indices, and inflammatory biomarkers that may aid sepsis diagnosis. The search for an ideal biomarker that has adequate diagnostic accuracy early in sepsis is still ongoing. We discuss promising strategies for the future that are being developed and tested that may help us diagnose sepsis early and improve clinical outcomes. IMPACT: Reviews the clinical relevance of currently available diagnostic tests for sepsis. Summarizes the diagnostic accuracy of novel biomarkers for neonatal sepsis. Outlines future strategies including the use of omics technology, personalized medicine, and point of care tests.

Daily monitoring of vaginal interleukin 6 as a predictor of intraamniotic inflammation after preterm premature rupture of membranes - a new method of sampling studied in a prospective multicenter trial

OBJECTIVES

(A) To introduce a new technique for vaginal fluid sampling (biocompatible synthetic fiber sponge) and (B) evaluate the collected vaginal fluid interleukine-6 (IL-6_vag)-concentration as a new diagnostic tool for daily monitoring of intrauterine inflammation after preterm premature rupture of membranes (PPROM). Secondary objectives were to compare the potential to predict an intrauterine inflammation with established inflammation parameters (e.g., maternal white blood cell count).

METHODS

This prospective clinical case-control diagnostic accuracy multicenter study was performed with women after PPROM (gestational age 24.0/7 - 34.0/7 weeks). Sampling of vaginal fluid was performed once daily. IL-6_vag was determined by electrochemiluminescence-immunoassay-kit. Neonatal outcome and placental histology results were used to retrospectively allocate the cohort into two subgroups: 1) inflammation and 2) no inflammation (controls).

RESULTS

A total of 37 cases were included in the final analysis. (A): Measurement of IL-6 was successful in 86% of 172 vaginal fluid samples. (B): Median concentration of IL-6_vag in the last vaginal fluid sample before delivery was significantly higher within the inflammation group (17,085 pg/mL) compared to the controls (1,888 pg/mL; p=0.01). By Youden's index an optimal cut-off for prediction an intrauterine inflammation was: 6,417 pg/mL. Two days before delivery, in contrast to all other parameters IL-6_vag remained the only parameter with a sufficient AUC of 0.877, p<0.001, 95%CI [0.670-1.000].

CONCLUSIONS

This study established a new technique for vaginal fluid sampling, which permits assessment of IL-6_vag concentration noninvasively in clinical daily routine monitoring.

Towards accurate exclusion of neonatal bacterial meningitis: a feasibility study of a novel 16S rDNA PCR assay

Background

PCRctic is an innovative assay based on 16S rDNA PCR technology that has been designed to detect a single intact bacterium in a specimen of cerebro-spinal fluid (CSF). The assay’s potential for accurate, fast and inexpensive discrimination of bacteria-free CSF makes it an ideal adjunct for confident exclusion of bacterial meningitis in newborn babies where the negative predictive value of bacterial culture is poor. This study aimed to stress-test and optimize PCRctic in the “field conditions” to attain a clinically useful level of specificity.

Methods

The specificity of PCRctic was evaluated in CSF obtained from newborn babies investigated for meningitis on a tertiary neonatal unit. Following an interim analysis, the method of skin antisepsis was changed to increase bactericidal effect, and snap-top tubes (Eppendorf™) replaced standard universal containers for collection of CSF to reduce environmental contamination.

Results

The assay’s specificity was 90.5% in CSF collected into the snap-top tubes – up from 60% in CSF in the universal containers. The method of skin antisepsis had no effect on the specificity. All CSF cultures were negative and no clinical cases of neonatal bacterial meningitis occurred during the study.

Conclusions

A simple and inexpensive optimization of CSF collection resulted in a high specificity output. The low prevalence of neonatal bacterial meningitis means that a large multi-centre study will be required to validate the assay’s sensitivity and its negative predictive value.

Neonatal Sepsis

Neonatal sepsis is associated with severe morbidity and mortality in the neonatal period. Clinical manifestations range from subclinical infection to severe local or systemic infection. Neonatal sepsis is divided into three groups as early-onset neonatal sepsis, late-onset neonatal sepsis and very late-onset neonatal sepsis according to the time of the onset. It was observed that the incidence of early-onset neonatal sepsis decreased with intrapartum antibiotic treatment. However, the incidence of late-onset neonatal sepsis has increased with the increase in the survival rate of preterm and very low weight babies. The source of the causative pathogen may be acquisition from the intrauterine origin but may also acquisition from maternal flora, hospital or community. Prematurity, low birth weight, chorioamnionitis, premature prolonged rupture of membranes, resuscitation, low APGAR score, inability to breastfeed, prolonged hospital stay and invasive procedures are among the risk factors. This article reviews current information on the definition, classification, epidemiology, risk factors, pathogenesis, clinical symptoms, diagnostic methods and treatment of neonatal sepsis.

Procalcitonin as an Early Laboratory Marker of Sepsis in Neonates: Variation in Diagnostic Performance and Discrimination Value

Background

As an early recognition of neonatal sepsis is important for triggering the initiation of treatment, this study was thus designed to assess the diagnostic performance and discrimination value of procalcitonin (PCT) in neonatal sepsis cases.

Methods

This cross-sectional study, which was carried out at the Paediatric Intensive Care Unit of Hospital Universiti Sains Malaysia (HUSM) in Kelantan, Malaysia, had involved 60 neonates admitted for suspected sepsis. Sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV) and the area under receiver operating characteristics curve (AUC) for PCT were determined at initial presentation (0 h) as well as 12 h and 24 h after presentation in comparison to blood culture as the gold standard.

Results

The study consisted of 27 (45.0%) male and 33 (55.0%) female neonates with a mean (SD) age of 76.8 (48.25) h. At cut-off PCT value of > 2 ng/mL, the sensitivity, specificity, PPV and NPV were 66.7%, 66.7%, 33.3% and 88.9% at 0 h. The respective parameters were 83.3%. 56.3%, 32.3% and 93.1% at 12 h and 83.3%, 52.1%, 30.3% and 92.6% at 24 h. AUC was 71.6%, 76.6% and 71.7% at 0 h, 12 h and 24 h.

Conclusions

Diagnostic performance and discrimination values of PCT for diagnosis of neonatal sepsis varied with time of obtaining the blood samples. The PCT result at 12 h demonstrates the most optimal diagnostic performance and discrimination values.

BLOOD CELLS PROFILE IN UMBILICAL CORD OF LATE PRETERM AND TERM NEWBORNS

OBJECTIVE

To describe the hematological profile in cord blood of late preterm and term newborns and compare blood indices according to sex, weight for gestational age and type of delivery.

METHODS

Cross-sectional study with late preterm and term newborns in a second-level maternity. Multiple gestation, chorioamnionitis, maternal or fetal hemorrhage, suspected congenital infection, 5-minute Apgar <6, congenital malformations, and Rh hemolytic disease were excluded. Percentiles 3, 5,10, 25, 50, 75, 90, 95 and 97 of blood indices were calculated for both groups.

RESULTS

2,662 newborns were included in the sample, 51.1% males, 7.3% late preterms, 7.8% small for gestational age (SGA) and 81.2% adequate for gestational age (AGA). Mean gestational age was 35.6±1.9 and 39.3±1.0 weeks, respectively, for premature and term neonates. The erythrocytes indices and white blood cells increased from 34-36.9 to 37-41.9 weeks. Basophils and platelets remained constant during gestation. Premature neonates presented lower values ​​of all blood cells, except for lymphocytes and eosinophils. SGA neonates presented higher values ​​of hemoglobin, hematocrit and lower values of leukocytes, neutrophils, bands, segmented, eosinophils, monocytes and platelets. Male neonates presented similar values ​​of erythrocytes and hemoglobin and lower leukocytes, neutrophils, segmented and platelets. Neonates delivered by C-section had lower values ​​of red blood cells and platelets. Chronic or gestational hypertension induced lower number of platelets.

CONCLUSIONS

Blood cells increased during gestation, except for platelets and basophils. SGA neonates had higher hemoglobin and hematocrit values and lower leukocytes. Number of platelets was smaller in male SGAs, born by C-section and whose mothers had hypertension.

Diagnostic value of neutrophil CD64 combined with CRP for neonatal sepsis: A meta-analysis

BACKGROUND

Sepsis is the leading cause of morbidity and mortality in newborns. CD64 combined with c-reactive protein (CRP) could improve the sensitivity and specificity of neonatal sepsis diagnosis, but the results were still controversial. Therefore, this meta-analysis was conducted to clarify the importance of CD64 combined with CRP in the diagnosis of neonatal sepsis.

METHODS

The researches published as of December 24, 2018 were comprehensively searched in PubMed, Embase (included Embase and Medline), the Cochrane Library and Web of Science. Totally, 8 articles were included, involving 1114 objects. Statistical calculations were performed using Stata14.0 and Review Manager 5.3.

RESULTS

The diagnostic accuracy of all included studies was pooled as follows: sensitivity, 0.95 (95% CI: 0.86-0.98); specificity, 0.86 (95% CI: 0.74-0.93); positive likelihood ratio (PLR), 6.8 (95% CI: 3.50-13.20); negative likelihood ratio (NLR), 0.06 (95% CI: 0.02-0.18); diagnostic odds ratio (DOR), 118.0 (95% CI: 25.00-549.00), and the area under the curve (AUC) was 0.96 (95% CI: 0.94-0.97). It was found that heterogeneity was not caused by threshold effect (P = 0.16), but the results of sensitivity (I² = 87.57%) and specificity (I² = 89.07%) analyses indicated significant heterogeneity between studies.

CONCLUSIONS

The combined application of CD64 and CRP improved the accuracy of neonatal sepsis diagnosis.

Immature to total neutrophil ratio as an early indicator of early neonatal sepsis

Background & Objectives:

Neonatal septicemia is responsible for 1.5 to 2.0 million deaths/year in the under developed countries of the world. Pakistan is number three among these countries and accounts for 7% of global neonatal deaths. The objective of the study was to determine the role of simple hematological parameter, immature to total neutrophil ratio (I/T ratio) in diagnosing early onset neonatal bacterial infection.

Methods:

A descriptive cross-sectional study was conducted in Neonatal Intensive Care Unit of Liaquat College of Medicine & Dentistry (LCMD) Hospital from January 2016 to January 2017. A total 85 neonates were admitted with clinical suspicion of presumed early onset sepsis or who had potential risk factors for sepsis like prematurity, prolonged rupture of membranes was carried out. After taking informed consent from parents of admitted neonates, data was collected in a structured questionnaire. Laboratory workup included White blood cell count, CRP, absolute neutrophil count, immature neutrophil count while blood C/S was kept as gold standard. Empirical antibiotics started after sample collection for workup. Manual differential count and immature neutrophil count of the peripheral blood smear was performed by a senior technician masked to clinical information. I/T ratio was calculated from WBC, neutrophils and immature neutrophil count by a simple formula.

Results:

Out of 85 neonates, 13 had positive blood cultures (15.29%). The mean white blood count was 18761.18 ± 8570.75 and mean I/T ratio was 0.1622 ± 0.0419. About 50% of proven sepsis cases had WBC higher than 26000 as compared to 50% of cases for negative diagnoses that had WBC <15500. The mean I/T in positive CRP 0.204 ± 0.04 was non-significantly higher as compared to negative CRP 0.151 ± 0.034 (p =0.084). Point biserial correlation revealed that I/T ratio was significant strong correlation (r_{pb =} 0.721, p < 0.001) and overall I/T ratio was a good indicator of a positive and negative blood culture result. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of I/T ratio were 76.47%, 83.82%, 54.16% and 93.44% respectively. Similarly majority of neonates having high I/T ratio also depicts positive C-reactive protein (CRP) (NPV 91.23%). Therefore, both I/T and CRP showed a high negative predictive value (I/T = 93.44% and CRP = 91.23%) in this study.

Conclusion:

I/T ratio is a useful tool for early onset sepsis (EOS) with reasonable specificity but cannot be relied upon as sole indicator. Combination of normal immature to total neutrophil Ratio with negative CRP values in neonates with presumed sepsis is an indicator of non-infected neonate which comprised 78.8% of our study population.

Haptoglobin improves acute phase response and endotoxin tolerance in response to bacterial LPS

Sepsis is characterized by delayed acute phase response and lowered immune tolerance in patients. Acute phase serum proteins, like Haptoglobin (Hp), have been associated with increased mortality in bacteria mediated acute lung inflammation and sepsis in neonates. However, it's direct role in modulating the immune response by regulating pro-inflammatory mediators leading to immune tolerant state and if gender affects its expression levels during bacterial infection, especially in blood has not been fully explored. To understand its specific role in endotoxin-mediated immune response, we investigated the correlation between the rise in Hp levels on bacterial infection and its influence on the expression of pro-inflammatory mediators in male and female Whole blood (WHB) and PBMCs. Here, we observed pathogen-specific and gender-specific expression of Hp. Gonadal steroid hormones differentially influenced the Hp expression in LPS-induced WHB, where the addition of Estrogen increased Hp expression, with suppression of TNFα, in both genders. Further on evaluating, the influence of Hp on TNFα expression in endotoxin tolerance (ET), we show that increased Hp levels directly reduced TNFα expression in ET models. Interestingly, blockade of secreted Hp significantly reversed the (ET) state, confirmed by a significant rise in TNFα expression in both ex vivo and in vitro ET models, indicating a possible feedback inhibition by Hp on inflammatory mediators like TNFα. We also investigated the role of PKCδ in the regulation of LPS induced secretion of acute phase proteins (Hp) in serum, where inhibition of PKCδ, reduced secretion of anti-microbial proteins in response to LPS shown by restored bacterial growth. These findings clearly highlight the crucial role of Hp in maintaining immune tolerance via suppressing the pro-inflammatory mediators and also in preventing bacterial proliferation in blood during infection.

Role of serum (1,3)-β-d-glucan assay in early diagnosis of invasive fungal infections in a neonatal intensive care unit

OBJECTIVES

To study the microbiological pattern of late onset neonatal sepsis cultures and to assess the diagnostic performance of serum (1,3)-β-d-glucan level for early diagnosis of invasive fungemia in high-risk infants admitted to a neonatal intensive care unit.

METHODS

A prospective multicenter clinical trial conducted on infants at high risk for invasive fungal infections, with suspected late onset sepsis, admitted to a neonatal intensive care unit at Mansoura University Children's Hospital and Mansoura General Hospital between March 2014 and February 2016.

RESULTS

A total of 77 newborn infants with high risk of invasive fungal infection were classified based on blood culture into three groups: no fungemia (41 neonates with proven bacterial sepsis), suspected fungemia (25 neonates with negative blood culture), and definite fungemia group (11 neonates with culture-proven Candida). The growing organisms were Klebsiella spp. (14/54); Escherichia coli (12/54); Staphylococcus spp. (12/54; coagulase-negative Staphylococcus [9/54]; Staphylococcus aureus [3/54]); Pseudomonas aerouginosa (3/54); and Proteus spp. (2/54). Moreover, 11/54 presented Candida. Serum (1,3)-β-d-glucan concentration was significantly lower in the no fungemia group when compared with the definite fungemia group. The best cut-off value of (1,3)-β-d-glucan was 99pg/mL with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 63.6%, 95.1%, 77.8%, 90.7%, and 88.5%, respectively.

CONCLUSION

(1,3)-β-d-glucan assay has a limited sensitivity with excellent specificity and negative predictive value, which allow its use as an aid in exclusion of invasive neonatal fungal infection. Accurate diagnosis and therapeutic decisions should be based on combining (1,3)-β-d-glucan assay with other clinical, radiological, and microbiological findings.

Diagnostic and Prognostic Validity of Proadrenomedullin among Neonates with Sepsis in Tertiary Care Hospitals of Southern India

Introduction

To evaluate Proadrenomedullin (Pro-ADM) as the diagnostic and prognostic marker in neonatal sepsis.

Materials and Methods

In this cross-sectional study, Pro-ADM levels were estimated in 54 neonates with clinical sepsis and positive sepsis screen (cases) and 54 controls without clinical sepsis. Repeat Pro-ADM levels were estimated after 72 hours in cases. Pro-ADM levels were compared with the clinical outcome.

Results and Discussion

Median Pro-ADM levels in cases were 31.8 (IQR: 27.8-39.4) pmol/ml which was significantly higher than controls 5.1 (IQR; 3.1-7.7) pmol/ml. From the constructed ROC curve, a value of 14.5 pmol/ml was taken as the cut-off for sepsis. Pro-ADM had 100% sensitivity, specificity, and positive predictive values (PPV) in detecting sepsis at 14.5 pmol/ml. Among cases, a decrease in Pro-ADM level by 10 pmol/ml was associated with 99% survival. Pro-ADM value of 35 pmol/ml had 100% specificity and PPV in predicting mortality.

Conclusion

Pro-ADM can be used as a single biomarker for detecting neonatal sepsis, predicting clinical outcome and prognosis.

Relationship between blood lactic acid, blood procalcitonin, C-reactive protein and neonatal sepsis and corresponding prognostic significance in sick children

The study was conducted to evaluate the relationship between the blood lactic acid (BLA) level, serum procalcitonin (PCT), C-reactive protein (CRP) and the severity and prognosis of neonatal sepsis. A retrospective analysis was conducted on 90 children with sepsis admitted into the Intensive Care Unit (ICU) of the Hubei Institute for Nationalities Af liated Hospital hospital. Patients were divided into the non-survival group and the survival group. Severity of the 90 patients was evaluated according to Neonatal Critical Illness Score (NCIS). Observations were made on changes of the levels of BLA, PCT and CRP, correlation between BLA, PCT, CRP and NCIS as well as the association of the levels of these proteins with the prognosis of the patients. The 90 sick children were divided into the survival group (61 cases, 67.7%) and the non-survival group (29 cases, 32.2%). They were further stratified into the extremely severe group (n=20), severe group (n=39) and non-severe group (n=31) according to NCIS scoring standard. The BLA and NCIS scores of the non-survival group were significantly greater than those of the survival group. The difference was statistically significant (P<0.05). We found that there was a significant negative correlation between the BLA values and NCIS scores of the two groups. We also demonstrated significant positive correlation between the BLA value, PCT and CR (P<0.05). We observed a significant negative correlation between PCT, CRP and NCIS scores (P<0.05). The PCT level of the non-survival group was significantly higher than that of the survival group (P<0.05), while the NCIS score was significantly lower than that of the survival group (P<0.05). The CRP and PCT protein expression results of the sepsis patients were higher than those of the control group. Therefore, there is a significant correlation between BLA, CRP, PCT and NCIS. The lower the NCIS score is, the more significant the increase of BLA, PCT and CRP. Thus, the combined detection of levels of BLA, PCT and CRP may predict the severity of neonatal sepsis patients and their prognosis.

Selenium status in neonates with connatal infection

Infectious diseases impair Se metabolism, and low Se status is associated with mortality risk in adults with critical disease. The Se status of neonates is poorly characterised, and a potential impact of connatal infection is unknown. We hypothesised that an infection negatively affects the Se status of neonates. We conducted an observational case-control study at three intensive care units at the Charité-Universitätsmedizin Berlin, Germany. Plasma samples were collected from forty-four neonates. On the basis of clinical signs for bacterial infection and concentrations of IL-6 or C-reactive protein, neonates were classified into control (n 23) and infected (n 21) groups. Plasma Se and selenoprotein P (SePP) concentrations were determined by X-ray fluorescence and ELISA, respectively, at day of birth (day 1) and 48 h later (day 3). Se and SePP showed a positive correlation in both groups of neonates. Se concentrations indicative of Se deficit in adults (500 ng/l). During antibiotic therapy, SePP increased significantly from day 1 (1·03 (sd 0·10) mg/l) to day 3 (1·34 (sd 0·10) mg/l), indicative of improved hepatic Se metabolism. We conclude that both Se and SePP are suitable biomarkers for assessing Se status in neonates and for identifying subjects at risk of deficiency.

Efficacy of new leukocyte parameters versus serum C-reactive protein, procalcitonin, and interleukin-6 in the diagnosis of neonatal sepsis

BACKGROUND

The aim of this study was to investigate and compare the efficacy of the new leukocyte parameters mean neutrophil and monocyte volume (MNV, MMV), conductivity (MNC, MMC), scattering (MNS, MMS) and volume distribution width (NDW, MDW) with serum C-reactive protein (CRP), procalcitonin (PC) and interleukin (IL)-6 in the diagnosis of neonatal sepsis.

METHODS

A total of 227 newborns (132 boys, 95 girls) were analyzed. There were 116 infants in the sepsis group (proven sepsis, n = 40; clinical sepsis, n = 76) and 111 in the control group. Venous blood samples were collected from infants at the time of diagnosis and complete blood count, peripheral blood smear, blood cultures, CRP, PC, IL-6 and MNV, MMV, MNC, MMC, MNS, MMS, NDW, and MDW were analyzed.

RESULTS

MNV, NDW, MMV and, MDW were higher in infants with sepsis than in controls (P < 0.05 for all). MNS was lower in the patients with sepsis (P = 0.002). There was no significant difference between the sepsis and control groups in terms of MNC, MMC and MMS.

CONCLUSION

Although the predictive value of leukocyte parameters including neutrophil and monocyte volume, conductivity, scattering and volume distribution width in the diagnosis of neonatal sepsis was lower than that of CRP, PC and IL-6, some of these new parameters may be useful in the differential diagnosis of newborn sepsis, along with the other screening tools. In particular, MNV seems to be the most useful parameter with the highest specificity; also, the importance of PC in the diagnosis of early onset sepsis was confirmed.

Clinical chorioamnionitis at term VI: acute chorioamnionitis and funisitis according to the presence or absence of microorganisms and inflammation in the amniotic cavity

OBJECTIVE

Neonates born to mothers with clinical chorioamnionitis at term are at an increased risk of infection. Acute subchorionitis, chorioamnionitis, and funisitis are considered placental histologic features consistent with acute inflammation according to the Society for Pediatric Pathology. The objectives of this study were to examine the performance of placental histologic features in the identification of: 1) microbial-associated intra-amniotic inflammation (intra-amniotic infection); and 2) fetal inflammatory response syndrome (FIRS).

METHODS

This retrospective cohort study included women with the diagnosis of clinical chorioamnionitis at term (n=45), who underwent an amniocentesis to determine: 1) the presence of microorganisms using both cultivation and molecular biologic techniques [polymerase chain reaction (PCR) with broad range primers]; and 2) interleukin (IL)-6 concentrations by enzyme-linked immunosorbent assay (ELISA). The diagnostic performance (sensitivity, specificity, accuracy, and likelihood ratios) of placental histologic features consistent with acute inflammation was determined for the identification of microbial-associated intra-amniotic inflammation and FIRS.

RESULTS

1) The presence of acute histologic chorioamnionitis and funisitis was associated with the presence of proven intra-amniotic infection assessed by amniotic fluid analysis; 2) funisitis was also associated with the presence of FIRS; 3) the negative predictive value of acute funisitis ≥stage 2 for the identification of neonates born to mothers with intra-amniotic infection was <50%, and therefore, suboptimal to exclude fetal exposure to bacteria in the amniotic cavity; and 4) acute funisitis ≥stage 2 had a negative predictive value of 86.8% for the identification of FIRS in a population with a prevalence of 20%.

CONCLUSION

Acute histologic chorioamnionitis and funisitis are associated with intra-amniotic infection and the presence of FIRS. However, current pathologic methods have limitations in the identification of the fetus exposed to microorganisms present in the amniotic cavity. Further studies are thus required to determine whether molecular markers can enhance the performance of placental pathology in the identification of neonates at risk for neonatal sepsis.

Oxidant and antioxidant status in neonatal proven and clinical sepsis according to selenium status

BACKGROUND

Selenium is a trace element required for the functioning of the immune system. Neonatal sepsis is a serious condition leading to morbidity and mortality in neonates worldwide. The purpose of this study was to measure selenium and plasma selenoprotein P (SePP), selenoenzyme activity, and alterations in oxidant/antioxidant status with immune biomarkers in neonates with clinical (n = 27) and proven neonatal sepsis (n = 25).

METHODS

Erythrocyte selenium and SePP; plasma lipid peroxidation (LP), protein oxidation and total antioxidant capacity and erythrocyte total glutathione (GSH) concentration; erythrocyte glutathione peroxidase (GPx), thioredoxin reductase (TrxR), catalase (CAT) and total superoxide dismutase (SOD) activity were measured spectrophotometrically/spectrofluorometrically. Plasma interleukin 2 and 6 were also measured.

RESULTS

Erythrocyte selenium and SePP were markedly lower both in the clinical and proven sepsis groups versus control. Erythrocyte GPx activity was higher only in the clinical sepsis group. TrxR activity was markedly lower in proven sepsis. SOD activity and GSH were markedly higher both in clinical sepsis and in proven sepsis. CAT activity was significantly higher both in clinical sepsis and in proven sepsis. LP and protein oxidation were significantly higher in both of the sepsis groups.

CONCLUSIONS

Both selenium-dependent and selenium-independent blood redox systems were altered in sepsis, suggesting that sepsis causes an imbalance between cellular antioxidant and oxidant states.

Risk Factors for Neonatal Sepsis and Method for Reduction of Blood Culture Contamination

BACKGROUND

False-positive blood cultures findings may lead to a falsely increased morbidity and increased hospital costs.

METHOD

The survey was conducted as retrospective - prospective study and included 239 preterm infants (born before 37 weeks of gestation) who were treated in Neonatal Intensive Care Unit (NICU) in Institute for Child and Youth Health Care of Vojvodina during one year (January 1st, 2012 to December 31st, 2012). The retrospective part of the study focused on examination of incidence of neonatal sepsis and determination of risk factors. In the prospective part of the study infants were sub-divided into two groups: Group 1- infants hospitalized in NICU during the first 6 months of the study; blood cultures were taken by the "clean technique" and checklists for this procedure were not taken. Group 2- neonates hospitalized in NICU during last 6 months of the study; blood cultures were taken by "sterile technique" and checklists for this procedure were taken.

RESULTS

The main risk factors for sepsis were prelabor rupture of membranes, low gestational age, low birth weight, mechanical ventilation, umbilical venous catheter placement, and abdominal drainage. Staphylococcus aureus and coagulase negative Staphylococcus were the most frequently isolated microorganisms in false-positive blood samples.

CONCLUSIONS

Education of employees, use of checklists and sterile sets for blood sampling, permanent control of false positive blood cultures, as well as regular and routine monthly reports are crucial for successful reduction of contamination rates.

Delta Neutrophil Index as a Marker for Differential Diagnosis between Acute Graft Pyelonephritis and Acute Graft Rejection

Introduction

The delta neutrophil index (DNI) is the fraction of circulating immature granulocytes, which reflect infectious and/or septic condition. Acute graft pyelonephritis (AGPN) versus acute graft rejection is a frequently encountered diagnostic and therapeutic dilemma in kidney transplant recipients, but little is known about the clinical usefulness of DNI value in the differentiation of the two conditions.

Material & Methods

A total of 90 episodes of AGPN or acute graft rejection were evaluated at the Kangdong Sacred Heart Hospital between 2008 and 2014. We performed retrospective analysis of demographic, clinical, and laboratory parameters data. Receiver operating curves (ROC) and multivariate logistic regression were conducted to ascertain the utility of DNI in discriminating between AGPN and acute graft rejection.

Results

AGPN group had significantly higher DNI values than acute graft rejection group (2.9% vs. 1.9%, P < 0.001). The area under the ROC curve for DNI value to discriminate between AGPN and acute graft rejection was 0.85 (95% confidence interval [CI]; 0.76–0.92, P < 0.001). A DNI value of 2.7% was selected as the cut-off value for AGPN, and kidney transplant recipients with a DNI value ≥ 2.7% were found to be at a higher risk of infection than those with a DNI < 2.7% (odd ratio [OR] 40.50; 95% CI 8.68–189.08; P < 0.001). In a multivariate logistic regression analysis, DNI was a significant independent factor for predicting AGPN after adjusting age, sex, log WBC count, log neutorphil count, log lymphocyte count, CRP concentration, and procalcitonin concentration (OR 4.32; 95% CI 1.81–10.34, P < 0.001).

Conclusions

This study showed that DNI was an effective marker to differentiate between AGPN and acute graft rejection. Thus, these finding suggest that DNI may be a useful marker in the management of these patients.

Total antioxidant and total oxidant states, and serum paraoxonase-1 in neonatal sepsis

BACKGROUND

Paraoxonase-1 (PON-1) is an enzyme with a glycoprotein structure that depends on calcium and which is located in serum high-density lipoprotein (HDL). The aim of this study was to evaluate PON-1, and oxidant/antioxidant state, before and after treatment for neonatal sepsis, and to determine the usability of PON-1 in neonatal sepsis treatment.

METHODS

A total of 35 neonatal sepsis patients and 35 healthy controls were included in the study. Activity of PON-1, total oxidant state (TOS) and total antioxidant state (TAS) were measured and oxidative stress index (OSI) was calculated.

RESULTS

In the neonatal sepsis patients, pre-treatment TAS, TOS and OSI were significantly higher than the post-treatment levels (P < 0.0001, P < 0.0001 and P < 0.0001, respectively), and PON-1 was significantly lower (P < 0.0001). Similarly, pre-treatment TAS, TOS and OSI in the sepsis group were also significantly higher than in the control group (P < 0.0001, P < 0.0001 and P < 0.0001, respectively) and PON-1 was significantly lower (P < 0.0001). Post-treatment TAS in the sepsis group was significantly higher than in the control group (P = 0.009), whereas post-treatment TOS, OSI and PON-1 in the sepsis group were not significantly different to the control group (P = 0.078, P = 0.597 and P = 0.086, respectively).

CONCLUSION

Low serum PON-1 was found in neonatal sepsis. Serum PON-1 is thought to be a useful biomarker to evaluate the effectiveness of treatment and recovery in neonatal sepsis.

Enteral L-Arginine and Glutamine Supplementation for Prevention of NEC in Preterm Neonates

Objective. Evaluating the efficacy and safety of arginine and glutamine supplementation in decreasing the incidence of NEC among preterm neonates. Methods. Prospective case-control study done on 75 preterm neonates ≤34 weeks, divided equally into L-arginine group receiving enteral L-arginine, glutamine group receiving enteral glutamine, and control group. Serum L-arginine and glutamine levels were measured at time of enrollment (sample 1), after 14 days of enrollment (sample 2), and at time of diagnosis of NEC (sample 3). Results. The incidence of NEC was 9.3%. There was no difference in the frequency of NEC between L-arginine and control groups (P > 0.05). NEC was not detected in glutamine group; L-arginine concentrations were significantly lower in arginine group than control group in both samples while glutamine concentrations were comparable in glutamine and control groups in both samples. No significant difference was found between groups as regards number of septic episodes, duration to reach full oral intake, or duration of hospital stay. Conclusion. Enteral L-arginine supplementation did not seem to reduce the incidence of NEC. Enteral glutamine may have a preventive role against NEC if supplied early to preterm neonates. However, larger studies are needed to confirm these findings. This work is registered in ClinicalTrials.gov (ClinicalTrials.gov Identifier: NCT01263041).

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.

Reference values for interleukin-6 and interleukin-8 in cord blood of healthy term neonates and their association with stress-related perinatal factors

BACKGROUND

Automated interleukin assays are promising diagnostic aids for early-onset neonatal sepsis, however, reference values for healthy term neonates are incompletely known. The goal of this study is to determine reference values for interleukin-6 (IL-6) and interleukin-8 (IL-8) in cord blood of healthy term neonates.

METHODS AND FINDINGS

Women were recruited from April 2012 to August 2012. IL-6 and IL-8 levels were measured using an automated immunometric assay (Immulite) in cord blood of 93 healthy term newborns, 60 of them were born via vaginal delivery and 33 by elective caesarean section (ECS). A mean value for IL-8 of 8.1 ± 3.0 pg/mL was found in cord blood of healthy term neonates, which apply to both vaginal delivery and ECS. Regarding IL-6, two values apply. For vaginal delivery, a median value of 3.3 pg/mL (range, <2 to 9.53 pg/mL) was found, while for ECS, a median value of <2 pg/mL (range, <2 to 48 pg/mL) applies.

CONCLUSIONS

We propose a reference value of <14.1 pg/mL for IL-8 (mean + 2SD), applying to vaginally delivered and ECS-delivered healthy term newborns. From a clinical point of view, we also propose one reference value for IL-6 to be applied to vaginally delivered and ECS-delivered healthy term newborns, which is <10.2 pg/mL (97.5th percentile total group). These values have to be validated in larger cohorts of neonates, inclusive of those with and without early-onset neonatal sepsis.

A "multi-hit" model of neonatal white matter injury: cumulative contributions of chronic placental inflammation, acute fetal inflammation and postnatal inflammatory events

OBJECTIVE

We sought to determine whether cumulative evidence of perinatal inflammation was associated with increased risk in a "multi-hit" model of neonatal white matter injury (WMI).

METHODS

This retrospective cohort study included very preterm (gestational ages at delivery <32 weeks) live-born singleton neonates delivered at Hutzel Women's Hospital, Detroit, MI, from 2006 to 2011. Four pathologists blinded to clinical diagnoses and outcomes performed histological examinations according to standardized protocols. Neurosonography was obtained per routine clinical care. The primary indicator of WMI was ventriculomegaly (VE). Neonatal inflammation-initiating illnesses included bacteremia, surgical necrotizing enterocolitis, other infections, and those requiring mechanical ventilation.

RESULTS

A total of 425 live-born singleton neonates delivered before the 32nd week of gestation were included. Newborns delivered of pregnancies affected by chronic chorioamnionitis who had histologic evidence of an acute fetal inflammatory response were at increased risk of VE, unlike those without funisitis, relative to referent newborns without either condition, adjusting for gestational age [odds ratio (OR) 4.7; 95% confidence interval (CI) 1.4-15.8 vs. OR 1.3; 95% CI 0.7-2.6]. Similarly, newborns with funisitis who developed neonatal inflammation-initiating illness were at increased risk of VE, unlike those who did not develop such illness, compared to the referent group without either condition [OR 3.6 (95% CI 1.5-8.3) vs. OR 1.7 (95% CI 0.5-5.5)]. The greater the number of these three types of inflammation documented, the higher the risk of VE (P<0.0001).

CONCLUSION

Chronic placental inflammation, acute fetal inflammation, and neonatal inflammation-initiating illness seem to interact in contributing risk information and/or directly damaging the developing brain of newborns delivered very preterm.

Serum Levels of Soluble Urokinase Plasminogen Activator Receptor in Infants with Late-onset Sepsis

BACKGROUND

Soluble urokinase plasminogen activator receptor (suPAR) has been studied in a variety of diseases. The aim of the study is to investigate the levels of suPAR in neonates with sepsis.

METHODS

The infants enrolled to this prospective study were classified into four groups. Group 1, 2, and 3 were referred as the patient groups (40 infants), and group 4 was referred as control group (26 infants). Blood samples for whole blood count, C-reactive protein (CRP), suPAR and blood culture were obtained before initiating antimicrobial therapy, and two further samples were obtained on day 3 and at the end of the treatment for CRP and suPAR.

RESULTS

The mean gestational ages of patient and control groups was similar. The median level of initial suPAR was 18.8 ng/mL (range 6.8-30.1 ng/mL) in the patient groups, and 6.0 ng/mL (range 3.7-10.8 ng/mL) in the control group (P < 0.001). A significant decrease in suPAR level was observed from the inclusion to the third day and end of the treatment (P < 0.001). The area under the curve (AUC) for suPAR is 0.959 (95% Cl: 0.919-0.999) and for CRP is 0.782 (95% Cl: 0.669-0.895). At a cut-off value of 11.3 ng/mL for suPAR the specificity was 100%, and the sensitivity was 82.5%. There was a positive correlation between laboratory values of CRP and suPAR (r: 0.359, P = 0.003).

CONCLUSION

This is the first study that investigated the levels of suPAR in neonates and our results demonstrate that suPAR is a powerful marker of inflammation in infants with sepsis.

Early-onset neonatal sepsis

Early-onset sepsis remains a common and serious problem for neonates, especially preterm infants. Group B streptococcus (GBS) is the most common etiologic agent, while Escherichia coli is the most common cause of mortality. Current efforts toward maternal intrapartum antimicrobial prophylaxis have significantly reduced the rates of GBS disease but have been associated with increased rates of Gram-negative infections, especially among very-low-birth-weight infants. The diagnosis of neonatal sepsis is based on a combination of clinical presentation; the use of nonspecific markers, including C-reactive protein and procalcitonin (where available); blood cultures; and the use of molecular methods, including PCR. Cytokines, including interleukin 6 (IL-6), interleukin 8 (IL-8), gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α), and cell surface antigens, including soluble intercellular adhesion molecule (sICAM) and CD64, are also being increasingly examined for use as nonspecific screening measures for neonatal sepsis. Viruses, in particular enteroviruses, parechoviruses, and herpes simplex virus (HSV), should be considered in the differential diagnosis. Empirical treatment should be based on local patterns of antimicrobial resistance but typically consists of the use of ampicillin and gentamicin, or ampicillin and cefotaxime if meningitis is suspected, until the etiologic agent has been identified. Current research is focused primarily on development of vaccines against GBS.

Genome-wide expression profiles in very low birth weight infants with neonatal sepsis

BACKGROUND

Bacterial sepsis is associated with high morbidity and mortality in preterm infants. However, diagnosis of sepsis and identification of the causative agent remains challenging. Our aim was to determine genome-wide expression profiles of very low birth weight (VLBW) infants with and without bacterial sepsis and assess differences.

METHODS

This was a prospective observational double-cohort study conducted in VLBW (<1500 g) infants with culture-positive bacterial sepsis and non-septic matched controls. Blood samples were collected as soon as clinical signs of sepsis were identified and before antibiotics were initiated. Total RNA was processed for genome-wide expression analysis using Affymetrix gene arrays.

RESULTS

During a 19-month period, 17 septic VLBW infants and 19 matched controls were enrolled. First, a three-dimensional unsupervised principal component analysis based on the entire genome (28 000 transcripts) identified 3 clusters of patients based on gene expression patterns: Gram-positive sepsis, Gram-negative sepsis, and noninfected control infants. Furthermore, these groups were confirmed by using analysis of variance, which identified a transcriptional signature of 554 of genes. These genes had a significantly different expression among the groups. Of the 554 identified genes, 66 belonged to the tumor necrosis factor and 56 to cytokine signaling. The most significantly overexpressed pathways in septic neonates related with innate immune and inflammatory responses and were validated by real-time reverse transcription polymerase chain reaction.

CONCLUSIONS

Our preliminary results suggest that genome-wide expression profiles discriminate septic from nonseptic VLBW infants early in the neonatal period. Further studies are needed to confirm these findings.

Proportionate reduction in uncertainty of late onset infection in pre-term infants by neutrophil CD64 measurement

OBJECTIVE

Establish how neutrophil CD64 performs as a marker of definite infection in pre-term infants in comparison to C reactive protein (CRP) and procalcitonin (PCT).

METHODS

A total of 38 pre-term infants with suspected late onset infection had CD64 measured by flow cytometry. Proportionate reduction in uncertainty (PRU) curves were generated for CD64 counts at various threshold values.

RESULTS

PRU curves reduced the residual uncertainty of the presence of infection by up to 64%.

CONCLUSIONS

The CD64 appears to be a useful point of care test (POCT) for further defining the likelihood of infection and performs better than CRP or PCT at helping to rule in infection.

Can procalcitonin be an accurate diagnostic marker for the classification of diabetic foot ulcers?

BACKGROUND

The differentiation of infected diabetic foot ulcers (IDFU) from non infected diabetic foot ulcers (NIDFU) is a challenging issue for clinicians.

OBJECTIVES

Recently, procalcitonin (PCT) was introduced as a remarkable inflammatory marker. We aimed to evaluate the accuracy of PCT in comparison to other inflammatory markers for distinguishing IDFU from NIDFU.

MATERIALS AND METHODS

We evaluated PCT serum level as a marker of bacterial infection in patients with diabetic foot ulcers. Sixty patients with diabetic foot ulcers were consecutively enrolled in the study. A total of 30 patients were clinically identified as IDFU by an expert clinician, taking as criteria for purulent discharges or at least two of manifestations of inflammation including warmth, redness, swelling and pain.

RESULTS

Procalcitonin, white blood cells (WBCs), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), were found significantly higher in the IDFU group compared to the NIDFU group. The best cut-off value, sensitivity and specificity were 40.5 mm/h, 90% and 94% for ESR, 7.1 mg/dL, 80% and 74% for CRP, 0.21, 70% and 74% for PCT, and 7.7×10(9)/L, 66% and 67% for WBCs, respectively. The area under the receiver operating characteristic curve for ESR was the greatest (0.967; P < 0.001), followed by CRP (0.871; P < 0.001), PCT (0.729; P < 0.001), and finally WBCs (0.721; P = 0.001).

CONCLUSIONS

These results suggest that PCT can be a diagnostic marker in combination with other markers like ESR and CRP to distinguish infected from non-infected foot ulcers, when clinical manifestations are un specific. Additional research is needed before the routine usage of PCT to better define the role of PCT in IDFU.

Value of a single C-reactive protein measurement at 18 h of age

OBJECTIVE

To evaluate the usefulness of a single C-Reactive Protein (CRP) measurement at 18 h of age to identify neonates where antibiotics started for possible early onset sepsis (EOS) could safely be discontinued.

DESIGN/METHODS

In a prospective cohort of 647 preterm (<35 weeks) and 555 late preterm (35-36 weeks) or term newborns with maternal and/or neonatal risk factors for EOS, CRP levels were measured between 15 and 21 h of age.

RESULTS

There were 16, 107 and 1079 neonates with proven EOS, possible EOS and no EOS, respectively. Among the 645 neonates with a CRP<10 mg/L, 1 had proven EOS, 43 had possible EOS and 601 (93.2%) were not infected. All with possible or proven EOS were either less than 35 weeks' gestation, symptomatic at the time of CRP assessment or remained on antibiotics because of maternal bacteraemia: they would therefore not be considered for discharge. There were 557 neonates with a 18-h CRP ≥ 10 mg/L. Of these, 15 had proven EOS, 64 had possible EOS, and 478 (85.8%) were not infected. Sensitivity and specificity of 18-h CRP for proven or possible EOS were 64% (95% CI 56 to 73) and 56% (95% CI 53 to 59), respectively. The negative predictive value was 93% (95% CI 91 to 95), and the positive predictive value was 14% (95% CI 11 to 17).

CONCLUSIONS

The duration of antibiotic treatment in neonates born beyond 34 weeks' gestation and asymptomatic at the time of CRP assessment could be potentially reduced with a diagnostic algorithm that includes a point-of-care 18-h CRP measurement. An elevated 18-h CRP in isolation should not be used as a reason to prolong antibiotics.

Comparison of 16S rRNA gene PCR and blood culture for diagnosis of neonatal sepsis

Septicemia is a common cause of morbidity and mortality among newborns in the developing world. However, accurate clinical diagnosis of neonatal sepsis is often difficult because symptoms and signs are often nonspecific. Blood culture has been the gold standard for confirmation of the diagnosis. However, the sensitivity is low and results are usually not promptly obtained. Therefore, the diagnosis of sepsis is often based on clinical signs in association with laboratory tests such as platelets count, immature/total neutrophils ratio (I/T), and a rise in C-reactive protein (CRP). Polymerase chain reaction (PCR) methods for the detection of neonatal sepsis represent new diagnostic tools for the early identification of pathogens.

METHODS

During a 4-month prospective study, 16S rRNA PCR was compared with conventional blood culture for the diagnosis of neonatal bacterial sepsis. In addition, the relationship between known risk factors, clinical signs, laboratory parameters, and the diagnosis of sepsis was considered.

RESULTS

Sepsis was suspected in 706 infants from the intensive neonatal care unit. They all were included in the study. The number of positive cultures and positive PCR results were 95 (13.5%) and 123 (17.4%), respectively. Compared with blood culture, the diagnosis of bacterial sepsis by PCR revealed a 100.0% sensitivity, 95.4% specificity, 77.2% positive predictive value, and 100.0% negative predictive value. In this study, Apgar scores at 5 min, weight, icterus, irritability, feeding difficulties, gestational age (GA), premature rupture of membrane (PRM), platelets count, I/T, and a marked rise in CRP were important in establishing the diagnosis of sepsis in the newborn. In addition, weight, GA, PRM, irritability, duration of antibiotic usage, mortality rate, and number of purulent meningitis cases were significantly different between early-onset sepsis and late-onset sepsis.

CONCLUSION

16S rRNA PCR increased the sensitivity in detecting bacterial DNA in newborns with signs of sepsis, allowed a rapid detection of the pathogens, and led to shorter antibiotic courses. However, uncertainty about the bacterial cause of sepsis was not reduced by this method. 16S rRNA PCR needs to be further developed and improved. Blood culture is currently irreplaceable, since pure isolates are essential for antimicrobial drug susceptibility testing.

Polymorphic mononuclear neutrophils CD64 index for diagnosis of sepsis in postoperative surgical patients and critically ill patients

BACKGROUND

Surface neutrophil CD64 expression is upregulated in patients with bacterial infection. As it was suggested that the CD64 index could be used to detect sepsis in hospitalized patients, we questioned whether the CD64 index could discriminate between septic patients and postoperative surgical patients, defined as systemic inflammatory response syndrome (SIRS), both admitted at the intensive care unit (ICU). Furthermore, we wondered whether the CD64 index was an improved diagnostic compared to standard assays used at the laboratory. For this, outclinic (OC) patients were included as controls.

METHODS

The Leuko64™ assay was used to determine the CD64 index in residual EDTA blood samples from selected septic patients (n=25), SIRS patients (n=19), and OC patients (n=24). Additionally, WBC count, neutrophilic and eosinophilic granulocyte count, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured simultaneously.

RESULTS

The CD64 index was higher in septic patients compared to both the SIRS and OC group (p<0.0001). In addition, the WBC count, neutrophil count, ESR and CRP were also higher in septic patients than the OC group (p<0.0001). However, only the WBC count, eosinopenia, and ESR were comparable between the SIRS and the sepsis group and proved to be discriminative to the OC group (p<0.05). The CD64 index demonstrated higher sensitivity and specificity than CRP, WBC count, neutrophilic and eosinophilic granulocyte count, and ESR.

CONCLUSIONS

A high CD64 index was found in septic intensive care patients, while a low CD64 index was observed in OC and SIRS patients, demonstrating that the CD64 index can be used for routine diagnostics in the ICU setting.

Diagnosis value of the serum amyloid A test in neonatal sepsis: a meta-analysis

Neonatal sepsis (NS), a common disorder for humans, is recognized as a leading global public health challenge. This meta-analysis was performed to assess the accuracy of the serum amyloid A (SAA) test for diagnosing NS. The studies that evaluated the SAA test as a diagnostic marker were searched in Pubmed, EMBASE, the Cochrane Library, and Google Network between January 1996 and June 2013. A total of nine studies including 823 neonates were included in our meta-analysis. Quality of each study was evaluated by the quality assessment of diagnostic accuracy studies tool (QUADAS). The SAA test showed moderate accuracy in the diagnosis of NS both at the first suspicion of sepsis and 8-96 h after the sepsis onset, both with Q* = 0.91, which is similar to the PCT and CRP tests for the diagnosis of NS in the same period. Heterogeneity between studies was also explained by cut-off point, SAA assay, and age of included neonates. On the basis of our meta-analysis, therefore, SAA could be promising and meaningful in the diagnosis of NS.

Clinical trials in neonatal sepsis

Antibiotic licensing studies remain a problem in neonates. The classical adult clinical syndrome-based licensing studies do not apply to neonates, where sepsis is the most common infection. The main obstacle to conducting neonatal antibiotic trials is a lack of consensus on the definition of neonatal sepsis itself and the selection of appropriate endpoints. This article describes the difficulties of the clinical and laboratory definitions of neonatal sepsis and reviews the varying designs of previous neonatal sepsis trials. The optimal design of future trials of new antibiotics will need to be based on pharmacokinetic/pharmacodynamic parameters, combined with adequately powered clinical studies to determine safety and efficacy.

Usefulness of urinary immune biomarkers in the evaluation of neonatal sepsis: a pilot project

OBJECTIVE

Our hypothesis is that specific proinflammatory and anti-inflammatory urinary cytokines are useful in the diagnostic evaluation of risk for sepsis in term neonates. We conducted a pilot, prospective hospital-based longitudinal observational study to test the urine of term neonates with a 13 biomarker panel of cytokines.

METHODS

Infants were divided into 2 groups: The control group (n = 15) consisted of infants admitted to newborn nursery, and the test group (n = 15) consisted of infants admitted to the neonatal intensive care unit for presumed sepsis. Bagged urine samples were collected from 30 term neonates for testing our hypothesis.

RESULTS

Urinary interleukin (IL)-8 (P = .004*), inducible protein (IP)-10 (P = .007*), and monocyte chemoattractant protein (MCP)-1 (P = .02) were significantly increased in the test group compared with the control group.

CONCLUSIONS

Urinary IL-8, IP-10, and MCP-1 are proinflammatory cytokines that are increased in the neonate during an infectious inflammatory process. These may be useful predictors as an adjunct to the current protocols to recognize neonatal sepsis.

Usefulness of the delta neutrophil index for assessing neonatal sepsis

AIM

We investigated the significance of the calculated delta neutrophil index (DNI) as a diagnostic factor for neonatal sepsis.

METHODS

In retrospective study, 24 infants were diagnosed with blood culture-proven sepsis, and 48 non-septic neonates matched for gestational age, and birth weight served as controls. Among the 24 infants with sepsis, 5 died within 7 days at diagnosis.

RESULTS

Mean DNI (at diagnosis, after 24 h and 72 h), CRP and WBC counts were significantly higher, and neutrophil and platelet counts were significantly lower in sepsis group than control group. In sepsis group, mean DNI at the time of diagnosis, DNI at 72 h, and CRP at 72 h were significantly higher, and platelet counts were significantly lower for patients with sepsis who died compared with those who survived. In multiple logistic regression analysis, mortality in neonates with sepsis significantly correlated with DNI at 72 h (OR 1.47, 95% CI 1.1-5.6, p = 0.032) and with platelet count (OR 0.93, 95% CI 0.51-0.99, p = 0.014). ROC analysis for DNI at 72 h revealed a cut-off value of 12%, which predicted mortality with 81% sensitivity and 87% specificity.

CONCLUSION

DNI may be a valuable tool in assessing the prognosis of patients with neonatal sepsis.

Cord blood interleukin-6 as a predictor of early-onset neonatal sepsis

AIM

To compare diagnostic accuracy in cord blood of interleukin-6 (IL-6) with C-reactive protein (CRP) as predictors of early-onset neonatal sepsis (EOS) in newborns with prenatal risk factors for infection.

METHODS

During 12 months, cord blood IL-6 and CRP were measured immediately after birth in neonates with prenatal risk factors of infection. The odds of developing sepsis based on IL-6 and CRP values were calculated using likelihood ratios (LR), and their accuracy as predictors was compared by binary logistic regression. Multivariable logistic regression analyses were performed to identify independent risk factors for sepsis.

RESULTS

Ten of 128 neonates (7.8%) were diagnosed with EOS confirmed with positive blood culture in five cases (3.9%). Cord blood IL-6 was a greater predictor of sepsis than CRP [ROC for IL-6 (0.88) vs. CRP (0.70)]. IL-6-positive and IL-6-negative LR [7.14 vs. -0.11] were superior to those calculated for CRP [2.86 vs. -0.51]. Chorioamnionitis and Apgar at 1 min were identified as independent risk factors for EOS.

CONCLUSIONS

Cord blood IL-6 showed superior LR than CRP; therefore, it is a better predictor to initiate treatment in neonates with prenatal infectious risk factors immediately after birth.

Systemic responses of preterm newborns with presumed or documented bacteraemia

AIM

To compare the frequency of elevated concentrations of inflammation-related proteins in the blood of infants born before the 28th week of gestation who had documented bacteraemia and those who had presumed (antibiotic-treated but culture-negative) bacteraemia to those who had neither.

METHODS

The subjects of this study are the 868 infants born at 14 institutions for whom information about protein measurements on at least two of the three protocol days (days 1, 7, and 14) was available and who did not have Bell stage 3 necrotizing enterocolitis or isolated bowel perforation, which were strongly associated with bacteraemia in this sample.

RESULTS

Newborns with presumed early (week 1) bacteraemia had elevated concentrations of only a few inflammation-related proteins, while those who had presumed late (weeks 2-4) bacteraemia did not have any elevations. In contrast, newborns who had documented early bacteraemia had a moderately strong signal, while those who had documented late bacteraemia had a stronger signal with more protein concentrations elevated on two separate occasions a week apart.

CONCLUSIONS

Culture-confirmed early and late bacteraemia are accompanied/followed by systemic inflammatory responses not seen with presumed early and late bacteraemia.

M-ficolin concentrations in cord blood are related to circulating phagocytes and to early-onset sepsis

INTRODUCTION

The pattern-recognition molecule M-ficolin is synthesized by monocytes and neutrophils. M-ficolin activates the complement system in a manner similar to mannan-binding lectin (MBL), but little is known about its role in host defense. Neonates are highly vulnerable to bacterial sepsis, in particular, due to their decreased phagocytic function.

RESULTS

M-ficolin cord blood concentration was positively correlated with the absolute phagocyte count (ρ 0.51, P < 0.001) and with immature/total neutrophil ratio (ρ 0.34, P < 0.001). When comparing infants with sepsis and controls, a high M-ficolin cord blood concentration (>1,000 ng/ml) was associated with early-onset sepsis (EOS) (multivariate odds ratio 10.92, 95% confidence interval 2.21-54.02, P = 0.003). Experimental exposure of phagocytes isolated from adult donors to Escherichia coli resulted in a significant time- and dose-dependent release of M-ficolin.

DISCUSSION

In conclusion, M-ficolin concentrations were related to circulating phagocytes and EOS. Our results indicate that bacterial sepsis can trigger M-ficolin release by phagocytes. Future studies should investigate whether M-ficolin may be used as a marker of neutrophil activation during invasive infections.

METHODS

We investigated M-ficolin in 47 infants with culture-positive sepsis during the first 30 days of life (13 with EOS and in 94 matched controls. M-ficolin was measured in cord blood using time-resolved immunofluorometric assay (TRIFMA). Multivariate logistic regression was performed.

Early diagnosis of sepsis using serum biomarkers

Sepsis, an innate immunological response of systemic inflammation to infection, is a growing problem worldwide with a relatively high mortality rate. Immediate treatment is required, necessitating quick, early and accurate diagnosis. Rapid molecular-based tests have been developed to address this need, but still suffer some disadvantages. The most commonly studied biomarkers of sepsis are reviewed for their current uses and diagnostic accuracies, including C-reactive protein, procalcitonin, serum amyloid A, mannan and IFN-γ-inducible protein 10, as well as other potentially useful biomarkers. A singular ideal biomarker has not yet been identified; an alternative approach is to shift research focus to determine the diagnostic relevancy of multiple biomarkers when used in concert. Challenges facing biomarker research, including lack of methodology standardization and assays with better detection limits, are discussed. The ongoing efforts in the development of a multiplex point-of-care testing kit, enabling quick and reliable detection of serum biomarkers, may have great potential for early diagnosis of sepsis.