Diagnostic markers of infection in neonates

Myocardial performance imaging for the early identification of cardiac dysfunction in neonates with sepsis

PURPOSE

The assessment of cardiac performance in septic new-borns is crucial for detecting hemodynamic instability and predicting outcome. The aim of the study is to assess myocardial performance in neonates with sepsis for the early identification of cardiac dysfunction.

PATIENTS AND METHODS

A case control study was carried out from September 2022 to May 2023 at the Neonatal Intensive care unit, Kasturba Medical College, Manipal. A total of 68 neonates were included in the study, with 33 females and 35 males. The study population was further subdivided into 3 groups namely preterm septic neonates (n = 21), term septic neonates (n = 10) and non-septic healthy controls (n = 37). The cardiac structure and function were assessed using conventional method, Tissue Doppler imaging (Sm) and speckle tracking echocardiography (GLS). The study was approved by the Institutional Ethics Committee at Kasturba Medical College, Manipal (approval number IEC: 90/2022). The CTRI registration number for the study is CTRI/2022/09/045437 and was approved on September 12, 2022. Prior to the neonate's enrolment, informed consent was obtained from their mothers or legal guardians.

RESULTS

Out of the total 68 neonates, 31 were cases and 37 were controls which included 33 females and 35 males. LV systolic function was not statistically significant between cases and controls. E/A ratio of the mitral valve was significantly lower in septic newborns than in healthy neonates. (1.01 ± 0.35 vs 1.18 ± 0.31, p < 0.05) preterm neonates showed significantly lower Lateral E' and RV E' velocities than term neonates. TAPSE was significantly lower in septic preterm neonates. (8.61 ± 1.28 vs. 10.7 ± 2.11, p < 0.05) No significant difference was noted in the Myocardial Performance Index between septic neonates and healthy neonates. LV Global Longitudinal Strain was slightly lower in preterm septic neonates than in term neonates with sepsis.

CONCLUSION

Septic newborns are associated with LV diastolic dysfunction, RV systolic dysfunction and substantially higher pulmonary systolic pressures.

Reliability of IL-6 Alone and in Combination for Diagnosis of Late Onset Sepsis: A Systematic Review

Diagnosis of neonatal sepsis is difficult due to nonspecific signs and symptoms. Interleukin-6 (IL-6) is a promising marker for neonatal sepsis. We aimed to test the accuracy of IL-6 in neonates after 72 h of life in case of late onset sepsis (LOS). We searched for studies regarding IL-6 accuracy for the diagnosis of LOS between 1990 and 2020 using the PubMed database. Following study selection, the reported IL-6 sensitivities and specificities ranged between 68% and 100% and 28% and 100%, with median values of 85.7% and 82% and pooled values of 88% and 78% (respectively) in the 15 studies including 1306 infants. Subgroup analysis revealed a better sensitivity (87% vs. 82%), but not specificity (both 86%), in preterm infants compared to term infants or mixed populations. Early sample collection revealed the highest sensitivity (84%), but had the lowest specificity (86%). To assess quality, we used a STARD checklist adapted for septic neonates and the QUADAS criteria. Limitations of this review include the heterogeneous group of studies on the one side and the small number of studies on the other side that analyzed different combinations of biomarkers. We concluded that IL-6 demonstrated good performance especially in the preterm infant population and the best results were achieved by measurements at the time of LOS suspicion.

Application of Advanced Molecular Methods to Study Early-Onset Neonatal Sepsis

Early-onset sepsis (EOS) is a global health issue, considered one of the primary causes of neonatal mortality. Diagnosis of EOS is challenging because its clinical signs are nonspecific, and blood culture, which is the current gold-standard diagnostic tool, has low sensitivity. Commonly used biomarkers for sepsis diagnosis, including C-reactive protein, procalcitonin, and interleukin-6, lack specificity for infection. Due to the disadvantages of blood culture and other common biomarkers, ongoing efforts are directed towards identifying innovative molecular approaches to diagnose neonates at risk of sepsis. This review aims to gather knowledge and recent research on these emerging molecular methods. PCR-based techniques and unrestricted techniques based on 16S rRNA sequencing and 16S-23S rRNA gene interspace region sequencing offer several advantages. Despite their potential, these approaches are not able to replace blood cultures due to several limitations; however, they may prove valuable as complementary tests in neonatal sepsis diagnosis. Several microRNAs have been evaluated and have been proposed as diagnostic biomarkers in EOS. T2 magnetic resonance and bioinformatic analysis have proposed potential biomarkers of neonatal sepsis, though further studies are essential to validate these findings.

Neutrophil extracellular traps in adult diseases and neonatal bacterial infectious diseases: A review

Neutrophils, the most abundant type of white blood cells, are pivotal in fighting bacterial infections due to their immunological and anti-infection capabilities. In recent years, scientists have discovered a novel mechanism known as neutrophil extracellular traps, which are fibrous networks primarily released by neutrophils that combat bacterial infections. There is a growing interest in studying NETs and their role in human infectious diseases, particularly in neonates susceptible to bacterial infections. NETs and their components have been found in various samples from neonatal-infected patients, providing a new route for early diagnosis of neonatal infectious diseases. This paper aims to summarize the studies on NETs in adult diseases and mainly discuss NETs in neonatal sepsis, necrotizing enterocolitis, and purulent meningitis, to provide scientific evidence for early monitoring, diagnosis, and treatment of neonatal infections.

Evaluating of neonatal early onset sepsis through lactate and base excess monitoring

Early-onset sepsis (EOS) is one of the leading causes of neonatal death and morbidity worldwide and timely initiation of antibiotic therapy is, therefore, of paramount importance. This study aimed to evaluate the predictive effect of lactate and base excess (BE) values in the cord arterial blood gas and the 6th hour of life venous blood gas analysis on clinical sepsis in newborns. This is a cohort case-control study. In this study, 104 cases were divided into clinical and suspected sepsis groups according to the evaluation at the 24th hour after delivery. Lactate and BE values were evaluated in the cord arterial blood gas analysis (ABGA) and at the postnatal 6th-hour venous blood gas. The cord ABGA and postnatal 6th-hour results were compared in the clinical and suspected sepsis groups. Clinical sepsis was found to be associated with a lactate value above 2 mMol/L at postnatal 6th-hour venous blood gas (p = 0.041). This association was the highest when the clinical sepsis group's postnatal 6th-hour lactate cut-off value was determined as 3.38 mMol/L (sensitivity 57.9% and specificity 68.5%) (p = 0.032). However, no association was found between clinical sepsis diagnosis and venous BE's value in cord ABGA at the postnatal 6th hour. We found that a venous lactate value above 3.38 mMol/L at the postnatal 6th hour was the cut-off value that could indicate early-onset clinical sepsis. However, none of the biomarkers used in diagnosing EOS can accurately show all cases.

Point-of-care diagnostics for sepsis using clinical biomarkers and microfluidic technology

Sepsis is a life-threatening immune response which is caused by a wide variety of sources and is a leading cause of mortality globally. Rapid diagnosis and appropriate antibiotic treatment are critical for successful patient outcomes; however, current molecular diagnostic techniques are time-consuming, costly and require trained personnel. Additionally, there is a lack of rapid point-of-care (POC) devices available for sepsis detection despite the urgent requirements in emergency departments and low-resource areas. Recent advances have been made toward developing a POC test for early sepsis detection that will be more rapid and accurate compared to conventional techniques. Within this context, this review discusses the use of current and novel biomarkers for early sepsis diagnosis using microfluidics devices for POC testing.

Effects of Sepsis on Immune Response, Microbiome and Oxidative Metabolism in Preterm Infants

This is a narrative review about the mechanisms involved in bacterial sepsis in preterm infants, which is an illness with a high incidence, morbidity, and mortality. The role of the innate immune response and its relationship with oxidative stress in the pathogenesis are described as well as their potential implementation as early biomarkers. Moreover, we address the impact that all the mechanisms triggered by sepsis have on the dysbiosis and the changes on neonatal microbiota.

Tackling Neonatal Sepsis-Can It Be Predicted?

(1) Background: Early signs of sepsis in a neonate are often subtle and non-specific, the clinical course rapid and fulminant. The aim of our research was to analyse diagnostic markers for neonatal sepsis and build an application which could calculate its probability. (2) Methods: A retrospective clinical study was conducted on 497 neonates treated at the Clinical Department of Neonatology of the University Children's Hospital in Ljubljana from 2007 to 2021. The neonates with a diagnosis of sepsis were separated based on their blood cultures, clinical and laboratory markers. The influence of perinatal factors was also observed. We trained several machine-learning models for prognosticating neonatal sepsis and used the best-performing model in our application. (3) Results: Thirteen features showed highest diagnostic importance: serum concentrations of C-reactive protein and procalcitonin, age of onset, immature neutrophil and lymphocyte percentages, leukocyte and thrombocyte counts, birth weight, gestational age, 5-min Apgar score, gender, toxic changes in neutrophils, and childbirth delivery. The created online application predicts the probability of sepsis by combining the data values of these features. (4) Conclusions: Our application combines thirteen most significant features for neonatal sepsis development and predicts the probability of sepsis in a neonate.

Systematic review and meta-analysis of the diagnostic value of four biomarkers in detecting neonatal sepsis in low- and middle-income countries

BACKGROUND

Biomarkers may enhance diagnostic capability for common paediatric infections, especially in low- and middle-income countries (LMICs) where standard diagnostic modalities are frequently unavailable, but disease burden is high. A comprehensive understanding of the diagnostic capability of commonly available biomarkers for neonatal sepsis in LMICs is lacking. Our objective was to systematically review evidence on biomarkers to understand their diagnostic performance for neonatal sepsis in LMICs.

METHODS

We conducted a systematic review and meta-analysis of studies published in English, Spanish, French, German, Dutch, and Arabic reporting the diagnostic performance of C reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell count (WBC) and procalcitonin (PCT) for neonatal sepsis. We calculated pooled test characteristics and the area under the curve (AUC) for each biomarker compared with the reference standards blood culture or clinical sepsis defined by each article.

RESULTS

Of 6570 studies related to biomarkers in children, 134 met inclusion criteria and included 23 179 neonates. There were 80 (59.7%) studies conducted in LMICs. CRP of ≥60 mg/L (AUC 0.87, 95% CI 0.76 to 0.91) among 1339 neonates and PCT of ≥0.5 ng/mL (AUC 0.87, 95% CI 0.70 to 0.92) among 617 neonates demonstrated the greatest discriminatory value for the diagnosis of neonatal sepsis using blood culture as the reference standard in LMICs.

CONCLUSIONS

PCT and CRP had good discriminatory value for neonatal sepsis in LMICs. ESR and WBC demonstrated poor discrimination for neonatal sepsis in LMICs. Future studies may incorporate biomarkers into clinical evaluation in LMICs to diagnose neonatal sepsis more accurately.

PROSPERO REGISTRATION NUMBER

CRD42020188680.

The use of neutrophil CD64 and monocyte HLA-DR sepsis index in the diagnosis of neonatal sepsis

Background

Neonatal septicemia remains one of the main causes of neonatal morbidity and mortality. However, there are challenges hindering the early diagnosis.

Results

nCD64 percent and MFI were not of statistical significance between the confirmed sepsis, clinical sepsis, and control groups (p = 0.453 and 0.149, respectively); meanwhile, the mHLA-DR percent and MFI were both of statistical significance (p = 0.001, 0.0001, respectively) with lower values in the proven sepsis group. Calculating the sepsis index, its value was 74.1% ± 45 SD in the control, 105.5% ± 73 SD probable sepsis group, and 180.6% ± 143 SD in the proven sepsis group; this was of a high statistical significance (p = 0.0001).

Conclusion

HLA-DR expression on monocytes and nCD64/mHLA-DR sepsis index are reliable indices for the early diagnosis of neonatal sepsis. The sepsis index could be feasibly analyzed by automated flow cytometry even in developing countries. In the future, these markers should be widely assessed as their results are rapid, reliable, and of low cost.

Automated Complete Blood Cell Count Using Sysmex XN-9000® in the Diagnosis of Newborn Infection

The early identification of septically infected newborn infants is important for ensuring good outcomes. Blood cell differentiations are helpful, but they are often time consuming and inaccurate. In this study, we evaluated the use of automatic white blood cell differentiations by flow cytometry for the diagnosis of neonatal sepsis. Episodes of suspected infection in neonates were retrospectively classified into two groups, unlikely infection (UI, levels of Interleukin-6 < 400 pg/mL or CRP within 48 h < 10 mg/L), n = 101 and probable infection (PI, Interleukin-6 ≥ 400 pg/mL or CRP within 48 h ≥ 10 mg/L), n = 98. Complete blood cell counts were performed by Sysmex XN-9000® using flow cytometry. Relative and absolute proportions of immature granulocytes were evaluated. Unexpectedly, the absolute count of immature granulocytes was significantly lower in the group of PI compared to UI neonates. Similar results were found when analysing the relative proportion of immature granulocytes among all neutrophil granulocytes. On the other hand, manually counted immature to total (I/T) ratios of granulocytes were higher in PI than in UI infants. Therefore, we conclude that differentiations of granulocytes by Sysmex XN-9000® can be used to distinguish between infected and uninfected neonates if the results are interpreted according to our findings. A low count of immature granulocytes as determined by Sysmex XN-9000® may indicate neonatal infection.

Diagnosis of Neonatal Sepsis: The Role of Inflammatory Markers

This is a narrative review on the role of biomarkers in the diagnosis of neonatal sepsis. We describe the difficulties to obtain standardized definitions in neonatal sepsis and discuss the limitations of published evidence of cut-off values and their sensitivities and specificities. Maternal risk factors influence the results of inflammatory markers as do gestational age, the time of sampling, the use of either cord blood or neonatal peripheral blood, and some non-infectious causes. Current evidence suggests that the use of promising diagnostic markers such as CD11b, CD64, IL-6, IL-8, PCT, and CRP, either alone or in combination, might enable clinicians discontinuing antibiotics confidently within 24-48 h. However, none of the current diagnostic markers is sensitive and specific enough to support the decision of withholding antibiotic treatment without considering clinical findings. It therefore seems to be justified that antibiotics are often initiated in ill term and especially preterm infants. Early markers like IL-6 and later markers like CRP are helpful in the diagnosis of neonatal sepsis considering the clinical aspect of the neonate, the gestational age, maternal risk factors and the time (age of the neonate regarding early-onset sepsis) of blood sampling.

Using Classification Tree Analysis to Predict the Type of Infection in Preterm Neonates: Proof of Concept Study

Supplemental Digital Content is available in the text.

BACKGROUND:

Late-onset neonatal sepsis is a major complication in preterm neonates. Early identification of the type of infection could help to improve therapy and outcome depending on the suspected microorganism by tailoring antibiotic treatment to the individual patient based on the predicted organism. Results of blood cultures may take up to 2 days or may remain negative in case of clinical sepsis. Chemical biomarkers may show different patterns in response to different type of microorganisms.

OBJECTIVE:

The aim of this study was to develop, as a proof of concept, a simple classification tree algorithm using readily available information from biomarkers to show that biomarkers can potentially be used in discriminating in the type of infection in preterm neonates suspected of late-onset neonatal sepsis.

DERIVATION COHORT:

A total of 509 suspected late-onset neonatal sepsis episodes in neonates born before less than 32 weeks of gestation were analyzed. To examine model performance, 70% of the original dataset was randomly selected as a derivation cohort (n = 356; training dataset).

VALIDATION COHORT:

The remaining 30% of the original dataset was used as a validation cohort (n = 153; test dataset).

PREDICTION MODEL:

A classification tree prediction algorithm was applied to predict type of infection (defined as no/Gram-positive/Gram-negative sepsis).

RESULTS:

Suspected late-onset neonatal sepsis episodes were classified as no sepsis (80.8% [n = 411]), Gram-positive sepsis (13.9% [n = 71]), and Gram-negative sepsis (5.3% [n = 27]). When the derived classification tree was applied to the test cohort, the overall accuracy was 87.6% (95% CI, 81.3–92.4; p = 0.008). The classification tree demonstrates that interleukin-6 is the most important differentiating biomarker and C-reactive protein and procalcitonin help to further differentiate.

CONCLUSION:

We have developed and internally validated a simple, clinically relevant model to discriminate patients with different types of infection at moment of onset. Further research is needed to prospectively validate this in a larger population and assess whether adaptive antibiotic regimens are feasible.

Knowledge gaps in late-onset neonatal sepsis in preterm neonates: a roadmap for future research

Late-onset neonatal sepsis (LONS) remains an important threat to the health of preterm neonates in the neonatal intensive care unit. Strategies to optimize care for preterm neonates with LONS are likely to improve survival and long-term neurocognitive outcomes. However, many important questions on how to improve the prevention, early detection, and therapy for LONS in preterm neonates remain unanswered. This review identifies important knowledge gaps in the management of LONS and describe possible methods and technologies that can be used to resolve these knowledge gaps. The availability of computational medicine and hypothesis-free-omics approaches give way to building bedside feedback tools to guide clinicians in personalized management of LONS. Despite advances in technology, implementation in clinical practice is largely lacking although such tools would help clinicians to optimize many aspects of the management of LONS. We outline which steps are needed to get possible research findings implemented on the neonatal intensive care unit and provide a roadmap for future research initiatives. IMPACT: This review identifies knowledge gaps in prevention, early detection, antibiotic, and additional therapy of late-onset neonatal sepsis in preterm neonates and provides a roadmap for future research efforts. Research opportunities are addressed, which could provide the means to fill knowledge gaps and the steps that need to be made before possible clinical use. Methods to personalize medicine and technologies feasible for bedside clinical use are described.

Introducing heart rate variability monitoring combined with biomarker screening into a level IV NICU: a prospective implementation study

The aim of this study was to investigate the association between the implementation of a local heart rate variability (HRV) monitoring guideline combined with determination of inflammatory biomarkers and mortality, measures of sepsis severity, frequency of sepsis testing, and antibiotic usage, among very preterm neonates. In January 2018, a guideline was implemented for early detection of late-onset neonatal sepsis using HRV monitoring combined with determination of inflammatory biomarkers. Data on all patients admitted with a gestational age at birth of < 32 weeks were reviewed in the period January 2016-June 2020 (n = 1,135; n = 515 pre-implementation, n = 620 post-implementation). Outcomes of interest were (sepsis-related) mortality, sepsis severity (neonatal sequential organ failure assessment (nSOFA)), sepsis testing, and antibiotic usage. Differences before and after implementation of the guideline were assessed using logistic and linear regression analysis for binary and continuous outcomes respectively. All analyses were adjusted for gestational age and sex. Mortality within 10 days of a sepsis episode occurred in 39 (10.3%) and 34 (7.6%) episodes in the pre- and post-implementation period respectively (P = 0.13). The nSOFA course during a sepsis episode was significantly lower in the post-implementation group (P = 0.01). We observed significantly more blood tests for determination of inflammatory biomarkers, but no statistically significant difference in number of blood cultures drawn and in antibiotic usage between the two periods.Conclusion: Implementing HRV monitoring with determination of inflammatory biomarkers might help identify patients with sepsis sooner, resulting in reduced sepsis severity, without an increased use of antibiotics or number of blood cultures.

Reliability of Interleukin-6 Alone and in Combination for Diagnosis of Early Onset Neonatal Sepsis: Systematic Review

Neonatal sepsis is a major cause of morbidity and mortality in both preterm and term infants. Early-onset neonatal sepsis (EONS) presents within the first 72 h of life. Diagnosis is difficult as signs and symptoms are non-specific, and inflammatory markers are widely used to confirm or rule out neonatal sepsis. Interleukin-6 (IL-6) is part of the fetal inflammatory response syndrome (FIRS) and therefore an interesting early marker for neonatal sepsis. The main objective for this review was to assess the diagnostic potential of IL-6, alone and in combination, for diagnosis of early neonatal sepsis (EONS) in term and preterm infants, in cord and peripheral blood, and in dependence of timing of sample collection. IL-6 diagnostic accuracy studies for diagnosing EONS published between 1990 and 2020 were retrieved using the PubMed database. We included 31 out of 204 articles evaluating the potential of IL-6 for the diagnosis of EONS in a study population of newborns with culture-proven and/or clinically suspected sepsis. We excluded articles dealing with neonatal bacterial infections other than sepsis and biomarkers other than inflammatory markers, those written in languages other than English or German, studies that did not distinguish between EONS and late-onset sepsis, and animal and in vitro studies. Full-text articles were checked for other relevant studies according to the PRISMA criteria. We identified 31 studies on IL-6 diagnostic accuracy for EONS diagnosis between 1990 and 2020 including a total of 3,276 infants. Sensitivity and specificity were reported, and subgroup analysis was performed. A STARD checklist adapted for neonates with neonatal sepsis was used for quality assessment. The range of IL-6 sensitivity and specificity in neonatal samples was 42.1-100% and 43-100%; the median values were 83 and 83.3%, respectively. IL-6 accuracy was better in preterm infants than in mixed-study populations. Early sample collection at the time of sepsis suspicion had the highest sensitivity when compared to other time points. Cord blood IL-6 had higher diagnostic value compared to peripheral blood. The biomarker combination of IL-6 and CRP was found to be highly sensitive, but poorly specific. Limitations of this review include use of only one database and inclusion of a heterogeneous group of studies and a small number of studies looking at biomarker combinations; a strength of this review is its focus on early-onset sepsis, since type of sepsis was identified as a significant source of heterogeneity in IL-6 diagnostic accuracy studies. We concluded that IL-6 has a good performance as an early diagnostic marker of EONS within a study population of preterm infants, with best results for cord blood IL-6 using cutoff values above 30 pg/ml.

Clinical and immunological aspects of microRNAs in neonatal sepsis

Neonatal sepsis constitutes a highly relevant public health challenge and is the most common cause of infant morbidity and mortality worldwide. Recent studies have demonstrated that during infection epigenetic changes may occur leading to reprogramming of gene expression. Post-transcriptional regulation by short non-coding RNAs (e.g., microRNAs) have recently acquired special relevance because of their role in the regulation of the pathophysiology of sepsis and their potential clinical use as biomarkers. ~22-nucleotide of microRNAs are not only involved in regulating multiple relevant cellular and molecular functions, such as immune cell function and inflammatory response, but have also been proposed as good candidates as biomarkers in sepsis. Nevertheless, establishing clinical practice guidelines based on microRNA patterns as biomarkers for diagnosis and prognosis in neonatal sepsis has yet to be achieved. Given their differential expression across tissues in neonates, the release of specific microRNAs to blood and their expression pattern can differ compared to sepsis in adult patients. Further in-depth research is necessary to fully understand the biological relevance of microRNAs and assess their potential use in clinical settings. This review provides a general overview of microRNAs, their structure, function and biogenesis before exploring their potential clinical interest as diagnostic and prognostic biomarkers of neonatal sepsis. An important part of the review is focused on immune and inflammatory aspects of selected microRNAs that may become biomarkers for clinical use and therapeutic intervention.

T cell cytokines in the diagnostic of early-onset sepsis

BACKGROUND

Early-onset sepsis (EOS) remains a substantial cause of morbidity and mortality among neonates. Yet, currently available biological parameters have not proven to be accurate enough to predict EOS reliably. This study aimed to determine serum concentrations of 13 cytokines in umbilical cord blood and evaluate their diagnostic value for EOS.

METHODS

A prospective single-center study that included analysis of umbilical cord blood of term and preterm neonates who were born from March 2017 to November 2017. Using ELISA analysis, 13 cytokines were simultaneously quantified and correlated with the development of EOS.

RESULTS

Four hundred and seventy-four neonates were included, of which seven met the criteria for culture-positive EOS. Interleukin (IL)-6 (p < 0.001), IL-9 (p = 0.003), and IL-21 (p < 0.001) were significantly increased in neonates with EOS compared to controls. Sensitivity and specificity for IL-6, IL-9, and IL-21 at the defined cut-off points were 85.7 and 77.3%, 71.4 and 62.5%, and 71.4 and 52.0%, respectively.

CONCLUSIONS

In neonates with EOS, IL-9 and IL-21 are significantly elevated and may be employed in the diagnostic of EOS. However, diagnostic accuracy remains lower than with IL-6. Values of 13 T cell cytokines may be used as reference values for future studies in neonates.

IMPACT

Interleukin-9 (IL-9) and interleukin-21 (IL-21) are significantly elevated in neonates with early-onset sepsis. IL-9 and IL-21 have been shown to play a specific role in neonatal sepsis. Neonatal reference values were generated for several cytokines. IL-9 and IL-21 might be attractive biomarkers for neonatal sepsis in future. This study is likely to promote further research in this area. Values of several T cell cytokines may be used as reference values for future studies in neonates.

Using evidence, expert opinion and epidemiological model to understand pathways to survival and mortality: The Pathways to Survival (PATHS) Tool

Background

The reasons why episodes of illness can lead to fatal outcomes in affected persons in low resource settings are numerous and complex. A tool that allows policy makers to better understand those complexities could be useful to improve success of programmes that are implemented globally to reduce mortality.

Methods

We developed a “Pathways to Survival” (PATHS) tool: an epidemiological model using decision trees, available evidence and expert opinion. PATHS visualises the “architecture” of mortality in the population by following the entire population cohort over a certain period of time. It explains how initially healthy persons progress through health systems to lethal outcomes at the end of the specified time period. We developed an illustrative example based on the 136 million newborns and an estimated 907 000 deaths from newborn sepsis in the year 2008. This allowed us to develop an epidemiological model that described pathways to deaths from neonatal sepsis globally in 2010.

Results

The model described the “status quo’ situation in 2010 with 907 000 deaths to allow an assessment of the potential impact and feasibility of different interventions and programmes at various level of health systems in reducing this cause of mortality. A useful model should incorporate both a ‘horizontal’ and a ‘vertical’ component. The ‘horizontal’ would track the progress of all neonates globally through time, ie, their first 28 days of life, and separate them into different ‘pathways’ every time a change in their risk of dying from neonatal infection occurs because of their specific contextual circumstances. The ‘vertical’ would track their position within the health systems of their countries and separate them into different categories based on the ability of health system to intervene and reduce their risk of dying. Based on those requirements, PATHS tool was developed which is based on decision trees where different “branches” of the trees are associated with varying case-fatality rates.

Conclusions

The application of the PATHS tool on the example of newborn sepsis revealed that novel diagnostic tests could save many lives, so we should continue to invest in them to improve their validity, deliverability and affordability. However, PATHS showed that investments in better diagnostics have limited impact unless they are coupled with improvements of the context. Programs for parental education improve compliance and care seeking. Promoting legislation change to empower community health workers (CHWs) to actively engage in prevention, diagnosis and care also makes a difference, as well as programs for training CHWs to use diagnostic tests and administer treatments correctly. Care-seeking behaviour can also be improved through programs of conditional cash transfers. Finally, PATHS demonstrated that improving access to primary and secondary health care for everyone is the most powerful contextual change.

Up-regulation of BTLA expression in myeloid dendritic cells associated with the treatment outcome of neonatal sepsis

Dentritic cells (DCs) dysfunction has been verified detrimental for sepsis and B and T lymphocyte attenuator (BTLA) is an immune-regulatory receptor shown to be associated with DCs dysfunction. However, the role of BTLA expression in myeloid DCs (mDCs) in neonatal sepsis is unknown. In the current study, we found BTLA-expressing mDCs were elevated in neonates with sepsis and the BTLA expression level in mDCs was positively correlated to the severity of sepsis. The presence of BTLA negatively regulated the phagocytosis capacity and bactericidal ability of mDCs as well as the maturation markers expression of mDCs. Our data also showed BTLA⁺mDCs shifted into an anti-inflammatory phenotype with decreased expression of IL-6, TNF-α and IL-12, but increased IL-10. in addition, we found BTLA expression indeedly altered the mDCs allo-stimulatory capacity. Therefore, BTLA expression in mDCs could be a useful predictive marker for neonatal sepsis and targeting BTLA expression in mDCs may be a new therapeutic strategy.

Directed Transport of CRP Across In Vitro Models of the Blood-Saliva Barrier Strengthens the Feasibility of Salivary CRP as Biomarker for Neonatal Sepsis

C-reactive protein (CRP) is a commonly used serum biomarker for detecting sepsis in neonates. After the onset of sepsis, serial measurements are necessary to monitor disease progression; therefore, a non-invasive detection method is beneficial for neonatal well-being. While some studies have shown a correlation between serum and salivary CRP levels in septic neonates, the causal link behind this correlation remains unclear. To investigate this relationship, CRP was examined in serum and saliva samples from 18 septic neonates and compared with saliva samples from 22 healthy neonates. While the measured blood and saliva concentrations of the septic neonates varied individually, a correlation of CRP levels between serum and saliva samples was observed over time. To clarify the presence of active transport of CRP across the blood–salivary barrier (BSB), transport studies were performed with CRP using in vitro models of oral mucosa and submandibular salivary gland epithelium. The results showed enhanced transport toward saliva in both models, supporting the clinical relevance for salivary CRP as a biomarker. Furthermore, CRP regulated the expression of the receptor for advanced glycation end products (RAGE) and the addition of soluble RAGE during the transport studies indicated a RAGE-dependent transport process for CRP from blood to saliva.

Association of inflammatory biomarkers with subsequent clinical course in suspected late onset sepsis in preterm neonates

BACKGROUND

Sepsis is a major health issue in preterm infants. Biomarkers are used to diagnose and monitor patients with sepsis, but C-reactive protein (CRP) is proven not predictive at onset of late onset neonatal sepsis (LONS) diagnosis. The aim of this study was to evaluate the association of interleukin-6(IL-6), procalcitonin (PCT) and CRP with subsequent sepsis severity and mortality in preterm infants suspected of late onset neonatal sepsis.

METHODS

The study was conducted at the Erasmus University Medical Center-Sophia Children's Hospital Rotterdam. Patient data from January 2018 until October 2019 were reviewed for all preterm neonates born with a gestational age below 32 weeks with signs and symptoms suggestive of systemic infection, in whom blood was taken for blood culture and for inflammatory biomarkers determinations. Plasma IL-6 and PCT were assessed next to CRP at the moment of suspicion. We assessed the association with 7-day mortality and sepsis severity (neonatal sequential organ failure assessment (nSOFA) score, need for inotropic support, invasive ventilation and thrombocytopenia).

RESULTS

A total of 480 suspected late onset neonatal sepsis episodes in 208 preterm neonates (gestational age < 32 weeks) were retrospectively analyzed, of which 143 episodes were classified as sepsis (29.8%), with 56 (11.7%) cases of culture negative, 63 (13.1%) cases of gram-positive and 24(5.0%) cases of gram-negative sepsis. A total of 24 (5.0%) sepsis episodes resulted in death within 7 days after suspicion of LONS. Both IL-6 (adjusted hazard ratio (aHR): 2.28; 95% CI 1.64-3.16; p < 0.001) and PCT (aHR: 2.91; 95% CI 1.70-5.00; p < 0.001) levels were associated with 7-day mortality; however, CRP levels were not significantly correlated with 7-day mortality (aHR: 1.16; 95% CI (0.68-2.00; p = 0.56). Log IL-6, log PCT and log CRP levels were all significantly correlated with the need for inotropic support.

CONCLUSIONS

Our findings show that serum IL-6 and PCT levels at moment of suspected late onset neonatal sepsis offer valuable information about sepsis severity and mortality risk in infants born below 32 weeks of gestation. The discriminative value was superior to that of CRP. Determining these biomarkers in suspected sepsis may help identify patients with imminent severe sepsis, who may require more intensive monitoring and therapy.

Evaluation of leucine-rich alpha-2 glycoprotein as a biomarker of fetal infection

This study aimed to determine the association between umbilical cord leucine-rich alpha-2 glycoprotein (LRG) and fetal infection and investigate the underlying mechanism of LRG elevation in fetuses. We retrospectively reviewed the medical records of patients who delivered at Osaka University Hospital between 2012 and 2017 and selected those with histologically confirmed chorioamnionitis (CAM), which is a common pregnancy complication that may cause neonatal infection. The participants were divided into two groups: CAM with fetal infection (CAM-f[+] group, n = 14) and CAM without fetal infection (CAM-f[−] group, n = 31). Fetal infection was defined by the histological evidence of funisitis. We also selected 50 cases without clinical signs of CAM to serve as the control. LRG concentrations in sera obtained from the umbilical cord were unaffected by gestational age at delivery, neonatal birth weight, nor the presence of noninfectious obstetric complications (all, p > 0.05). Meanwhile, the LRG levels (median, Interquartile range [IQR]) were significantly higher in the CAM-f(+) group (10.37 [5.21–13.7] μg/ml) than in the CAM-f(−) (3.61 [2.71–4.65] μg/ml) or control group (3.39 [2.81–3.93] μg/ml; p < 0.01). The area under the receiver operating characteristic (ROC) curve of LRG for recognizing fetal infection was 0.92 (optimal cutoff, 5.08 μg/ml; sensitivity, 86%; specificity, 88%). In a mouse CAM model established by lipopolysaccharide administration, the fetal LRG protein in sera and LRG mRNA in the liver were significantly higher than those in phosphate-buffered saline (PBS)-administered control mice (p < 0.01). In vitro experiments using a fetal liver-derived cell line (WRL68) showed that the expression of LRG mRNA was significantly increased after interleukin (IL)-6, IL-1β, and tumor necrosis factor- alpha (TNF-α) stimulation (p < 0.01); the induction was considerably stronger following IL-6 and TNF-α stimulation (p < 0.01). In conclusion, LRG is an effective biomarker of fetal infection, and fetal hepatocytes stimulated with inflammatory cytokines may be the primary source of LRG production in utero.

The Utility of Neutrophil CD64 and Presepsin as Diagnostic, Prognostic, and Monitoring Biomarkers in Neonatal Sepsis

Background

Neonatal septicemia is a critical medical situation; current conventional laboratory methods still have many limitations and diagnostic obstacles. For this purpose, last decades have witnessed a challenge between the battery of sepsis biomarkers including many leukocyte surface antigens, not only for early diagnostic purposes but also for better follow-up and good management of sepsis patients.

Aim

To evaluate the diagnostic, prognostic, and monitoring performance of both neutrophil CD64 (nCD64) and presepsin as sepsis biomarkers compared to each other and to the conventional laboratory sepsis parameters aiming to decide which is the best fitting for routine daily use in neonatal intensive care units (NICUs).

Methods

235 neonates were enrolled from three Egyptian neonatal ICUs, during the period from November 2015 till March 2018; they were classified into two main groups: the control group (n = 102) and the sepsis group (n = 133). Laboratory sepsis evaluation included highly sensitive CRP (hs-CRP), CBC, in addition to nCD64 (flow cytometry technique), and presepsin measurement (CLEIA technique combined with Magtration® technology); the diagnosis was confirmed thereafter by positive blood culture results (BacT/Alert system). Sixty-two of the enrolled sepsis neonates were subjected to follow-up assessment; they were reclassified according to their clinical improvement at the second time assessment into (group 1: sepsis group without improvement) (n = 20) and (group 2: improved sepsis group) (n = 42).

Results

Significant increase in nCD64 and presepsin values was found in sepsis groups compared to the controls. At cutoff 41.6%, nCD64% could discriminate the presence of septicemia with sensitivity 94.7%, specificity 93.6 %, and AUC 0.925, while presepsin at cutoff 686 pg/ml achieves sensitivity 82.7%, specificity 95.5%, and AUC 0.887, respectively. Significant increase in nCD64 (P < 0.001) and hs-CRP (P=0.018) values was observed in severe sepsis/septic shock patients compared to nonsevere sepsis patients. Delta change percentage (dC%) between initial and follow-up evaluations for both improved and nonimproved sepsis patients was dC Z value −5.904 for nCD64% followed by dC Z value −4.494 for presepsin.

Conclusion

nCD64 and presepsin are valuable early diagnostic and monitoring sepsis biomarkers; the highest sensitivity could be achieved by a univariant sepsis marker in this study was recorded by the nCD64% biomarker, while the highest specificity was documented by presepsin. Combined measurement of both achieves the highest diagnostic performance in sepsis neonates. Either of CD64 or presepsin combined with hs-CRP associated with better performance than any of them alone. nCD64 carries an additional promising role in reflecting sepsis prognosis.

miRNA-23b as a biomarker of culture-positive neonatal sepsis

BACKGROUND

Neonatal sepsis remains an important cause of morbidity and mortality. The ability to quickly and accurately diagnose neonatal sepsis based on clinical assessments and laboratory blood tests remains difficult, where haemoculture is the gold standard for detecting bacterial sepsis in blood culture. It is also very difficult to study because neonatal samples are lacking.

METHODS

Forty-eight newborns suspected of sepsis admitted to the Neonatology Department of the Mother-Child Specialized Hospital of Tlemcen. From each newborn, a minimum of 1-2 ml of blood was drawn by standard sterile procedures for blood culture. The miRNA-23b level in haemoculture was evaluated by RT-qPCR.

RESULTS

miR-23b levels increased in premature and full-term newborns in early onset sepsis (p < 0.001 and p < 0.005 respectively), but lowered in late onset sepsis in full-term neonates (p < 0.05) compared to the respective negative controls. miR-23b levels also increased in late sepsis in the negative versus early sepsis negative controls (p < 0.05). miR-23b levels significantly lowered in the newborns who died from both sepsis types (p < 0.0001 and p < 0.05 respectively). In early sepsis, miR-23b and death strongly and negatively correlated (correlation coefficient = - 0.96, p = 0.0019). In late sepsis, miRNA-23b and number of survivors (correlation coefficient = 0.70, p = 0.506) positively correlated.

CONCLUSIONS

Lowering miR-23b levels is an important factor that favours sepsis development, which would confirm their vital protective role, and strongly suggest that they act as a good marker in molecular diagnosis and patient monitoring.

Challenges in developing a consensus definition of neonatal sepsis

Sepsis remains a leading cause of morbidity and mortality in the neonatal population, and at present, there is no unified definition of neonatal sepsis. Existing consensus sepsis definitions within paediatrics are not suited for use in the NICU and do not address sepsis in the premature population. Many neonatal research and surveillance networks have criteria for the definition of sepsis within their publications though these vary greatly and there is typically a heavy emphasis on microbiological culture. The concept of organ dysfunction as a diagnostic criterion for sepsis is rarely considered in neonatal literature, and it remains unclear how to most accurately screen neonates for organ dysfunction. Accurately defining and screening for sepsis is important for clinical management, health service design and future research. The progress made by the Sepsis-3 group provides a roadmap of how definitions and screening criteria may be developed. Similar initiatives in neonatology are likely to be more challenging and would need to account for the unique presentation of sepsis in term and premature neonates. The outputs of similar consensus work within neonatology should be twofold: a validated definition of neonatal sepsis and screening criteria to identify at-risk patients earlier in their clinical course. IMPACT: There is currently no consensus definition of neonatal sepsis and the definitions that are currently in use are varied.A consensus definition of neonatal sepsis would benefit clinicians, patients and researchers.Recent progress in adults with publication of Sepsis-3 provides guidance on how a consensus definition and screening criteria for sepsis could be produced in neonatology.We discuss common themes and potential shortcomings in sepsis definitions within neonatology.We highlight the need for a consensus definition of neonatal sepsis and the challenges that this task poses.

Evaluation of the clinical value of circulating miR-101, miR-187 and miR-21 in neonatal sepsis diagnosis and prognosis

Background

Neonatal sepsis is considered as a complicated syndrome, which requires urgent intervention to avoid the unfavorable outcome. Thus, biomarkers that can either distinguish sepsis early or predict sepsis outcome are of critical need. Therefore, the aim of the current study was to investigate the clinical value of miR-187, miR-101, and miR-21 on neonatal sepsis diagnosis and prediction of prognosis. Fifty neonates with sepsis, 30 neonates with SIRS, and 20 healthy neonates were selected. Relative expression levels of the selected miRNAs were quantified by qRT-PCR. Serum CRP and PCT were analyzed.

Results

miR-101 and miR-187 expression levels were elevated in septic neonates compared with SIRS neonates and normal controls. The AUC of miR-101, miR-187, and PCT to predict sepsis diagnosis were 0.908, 789, and 0.856, respectively. miR-21 expression levels in non-survivors were significantly higher than in survivors. The AUC of miR-21, a score of neonatal acute physiology (SNAP-II), and PCT to detect the predictive mortality value were 0.793, 0.781, and 0.635, respectively. Survival analysis revealed that high miR-21 expression levels were related to low survival rates. miR-21 and SNAP II were independent risk factors for sepsis mortality, and the AUC of the two combined variables’ predictive probabilities was 0.926 and yielded a specificity of 91.2% and a sensitivity of 81.3%, which was higher than that of either miR-21 or SNAP II.

Conclusion

miR-101 might function as a hopeful diagnostic biomarker for neonatal sepsis. Additionally, miR-21 gained attention to be a valuable predictor for sepsis prognosis especially if combined with SNAP II.

Advantages and Limitations of the Neonatal Immune System

During early post-natal life, neonates must adjust to the transition from the sheltered intra-uterine environment to the microbe-laden external world, wherein they encounter a constellation of antigens and the colonization by the microbiome. At this vulnerable stage, neonatal immune responses are considered immature and present significant differences to those of adults. Pertinent to innate immunity, functional and quantitative deficiencies in antigen-presenting cells and phagocytes are often documented. Exposure to environmental antigens and microbial colonization is associated with epigenetic immune cell reprogramming and activation of effector and regulatory mechanisms that ensure age-depended immune system maturation and prevention of tissue damage. Moreover, neonatal innate immune memory has emerged as a critical mechanism providing protection against infectious agents. Still, in neonates, inexperience to antigenic exposure, along with enhancement of tissue-protective immunosuppressive mechanisms are often associated with severe immunopathological conditions, including sepsis and neurodevelopmental disorders. Despite significant advances in the field, adequate vaccination in newborns is still in its infancy due to elemental restrictions associated also with defective immune responses. In this review, we provide an overview of neonatal innate immune cells, highlighting phenotypic and functional disparities with their adult counterparts. We also discuss the effects of epigenetic modifications and microbial colonization on the regulation of neonatal immunity. A recent update on mechanisms underlying dysregulated neonatal innate immunity and linked infectious and neurodevelopmental diseases is provided. Understanding of the mechanisms that augment innate immune responsiveness in neonates may facilitate the development of improved vaccination protocols that can protect against pathogens and organ damage.

Reference ranges of presepsin (soluble CD14 subtype) in term and preterm neonates without infection, in relation to gestational and postnatal age, in the first 28 days of life

OBJECTIVE

To determine the reference ranges of presepsin in term and preterm neonates without infection, with respect to gestational and postnatal age, within the first 28 days of life.

METHODS

A total of 144 neonates born at 24-42 weeks' gestation, including healthy term and preterm neonates without clinical signs or symptoms of infection, were included in this prospective observational study. Presepsin measurements included cord blood levels and serum levels on postnatal days 1, 3, 5, 7, 14, 21, and 28.

RESULTS

The presepsin values corresponding to the 10th percentile ranged from 240.8 pg/mL (on day 1) to 129.9 pg/mL (on day 28), whereas those corresponding to the 90th percentile ranged from 725.8 pg/mL (on day 1) to 471.6 pg/mL (on day 28). Significantly higher presepsin levels were observed in cesarean deliveries than in spontaneous deliveries (p: 0.012 to <0.001), in gestational ages ≤ 32 weeks than in gestational ages ≥37 weeks (p: <0.05 to <0.001), and in cases with a maternal history of chorioamnionitis than in those without (p: <0.05 to <0.001).

CONCLUSION

In conclusion, our findings revealed, for the first time, the reference ranges of presepsin in healthy term and preterm neonates without infection with respect to gestational and postnatal age, sex, and body weight. Presepsin levels within the first 28 days of life seem likely to be affected by the type of delivery, gestational and postnatal age, birth weight, and presence of respiratory distress syndrome or maternal chorioamnionitis.

Rapid Proteome Changes in Plasma and Cerebrospinal Fluid Following Bacterial Infection in Preterm Newborn Pigs

Background: Neonatal infection and sepsis are common for preterm infants due to their immature immune system. Early diagnosis is important for effective treatment, but few early markers of systemic and neuro-inflammatory responses in neonates are known. We hypothesised that systemic infection with Staphylococcus epidermidis (SE), a Gram-positive bacteria, induces acute changes to proteins in the plasma and cerebrospinal fluid (CSF), potentially affecting the immature brain of preterm neonates.

Methods: Using preterm pigs as a model for preterm infants, plasma and CSF samples were collected up to 24 h after SE infection and investigated by untargeted mass spectrometry (MS)-based proteomics. Multiple differentially expressed proteins were further studied in vitro.

Results: The clinical signs of sepsis and neuroinflammation in SE-infected piglets were associated with changes of multiple CSF and plasma proteins. Eight plasma proteins, including APOA4, haptoglobin, MBL1, vWF, LBP, and sCD14, were affected 6 h after infection. Acute phase reactants, including complement components, showed a time-dependent activation pattern after infection. Feeding bovine colostrum reduced the sepsis-related changes in clinical indices and plasma proteins. Neuroinflammation-related neuropeptide Y (NPY), IL-18, and MMP-14 showed distinct changes in the CSF and several brain regions (the prefrontal cortex, PVWM, and hippocampus) 24 h after infection. These changes were verified in TLR2 agonist-challenged primary microglia cells, where exogenous NPY suppressed the inflammatory response.

Conclusion: Systemic infection with SE induces inflammation with rapid proteome changes in the plasma and CSF in preterm newborn pigs. The observed early markers of sepsis and neuroinflammation in preterm pigs may serve as novel biomarkers for sepsis in preterm infants.

Development, evaluation and validation of a screening tool for late onset bacteremia in neonates - a pilot study

Background

Clinical and laboratory parameters can aid in the early identification of neonates at risk for bacteremia before clinical deterioration occurs. However, current prediction models have poor diagnostic capabilities. The objective of this study was to develop, evaluate and validate a screening tool for late onset (> 72 h post admission) neonatal bacteremia using common laboratory and clinical parameters; and determine its predictive value in the identification of bacteremia.

Methods

A retrospective chart review of neonates admitted to a neonatal intensive care unit (NICU) between March 1, 2012 and January 14, 2015 and a prospective evaluation of all neonates admitted between January 15, 2015 and March 30, 2015 were completed. Neonates with late-onset bacteremia (> 72 h after NICU admission) were eligible for inclusion in the bacteremic cohort. Bacteremic patients were matched to non-infected controls on several demographic parameters. A Pearson’s Correlation matrix was completed to identify independent variables significantly associated with infection (p < 0.05, univariate analysis). Significant parameters were analyzed using iterative binary logistic regression to identify the simplest significant model (p < 0.05). The predictive value of the model was assessed and the optimal probability cut-off for bacteremia was determined using a Receiver Operating Characteristic curve.

Results

Maximum blood glucose, heart rate, neutrophils and bands were identified as the best predictors of bacteremia in a significant binary logistic regression model. The model’s sensitivity, specificity and accuracy were 90, 80 and 85%, respectively, with a false positive rate of 20% and a false negative rate of 9.7%. At the study bacteremia prevalence rate of 51%, the positive predictive value, negative predictive value and negative post-test probability were 82, 89 and 11%, respectively.

Conclusion

The model developed in the current study is superior to currently published neonatal bacteremia screening tools. Validation of the tool in a historic data set of neonates from our institution will be completed.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1633-1) contains supplementary material, which is available to authorized users.

Implementation of a clinical guideline to decrease laboratory tests in newborns evaluated for early onset sepsis

BACKGROUND

Creation of a clinical guideline to reduce the number of complete blood counts (CBCs) obtained on healthy term infants for early onset sepsis (EOS) evaluation secondary to maternal chorioamnionitis.

METHODS

A clinical guideline was introduced at four neonatal intensive care units (NICU) to reduce laboratory tests during EOS evaluation. Measures include frequency and timing of CBCs, culture negative sepsis, length of stay, and readmission rate.

RESULTS

Mean number of CBCs per patient significantly decreased (2.31±0.62 versus 1.52±0.65) without increasing trends for patients with culture negative sepsis, length of stay, or re-admission.

CONCLUSION

The clinical guideline demonstrated a significant reduction in the number of CBCs obtained in well-appearing infants admitted to the NICU secondary to maternal chorioamnionitis.

Diagnostic accuracy of interleukin-6 for early-onset sepsis in preterm neonates

Background: Early-onset sepsis (EOS) is a leading cause of morbidity and mortality among neonates. Yet, accurate diagnosis remains a major challenge in clinical routine.Objective: The aim of this study was to evaluate the diagnostic accuracy of Interleukin-6 (IL-6) in combination with other objective perinatal data for early-onset sepsis (EOS) in preterm neonates.Methods: We conducted a retrospective nested case-control study with preterm neonates with a birth weight < 2000 g born in our NICU between January 2007 and June 2016. Differences of IL-6 levels and other perinatal clinical and laboratory data between neonates with and without EOS were statistically analyzed.Results: Sixty-seven preterm infants with and 115 neonates without EOS were included in this study. Specificity and sensitivity for IL-6 were 72.8% and 75.0%, respectively, with an area under the curve of 0.804 at a cut-off point of 40 ng/l. Depending on the statistical method applied, combining IL-6 with a second perinatal factor led either to an increase of specificity (82.4-100%) or sensitivity (75.0-92.2%).Conclusion: The combination of IL-6 with other perinatal factors can significantly increase specificity and sensitivity in the diagnosis of EOS. However, overall diagnostic accuracy cannot be notably improved as there is a tradeoff between sensitivity and specificity. Although these findings do not necessarily apply in clinical routine, they can be of substantial value in the assistance of individual decision making.

The Association between the Level of Antithrombin III and Mortality in Children with Sepsis

BACKGROUND

Sepsis is a significant cause of morbidity and mortality in children. The diagnosis of sepsis remains continuing to develop which determines treatment and prognostic. Antithrombin III is one of the coagulation markers to evaluate the prognosis of sepsis.

AIM

To determine the association between the level of antithrombin III and mortality in children with sepsis in the Pediatric Intensive Care Unit, Haji Adam Malik General Hospital, Medan.

METHODS

A cross-sectional study was conducted in Haji Adam Malik General Hospital, Medan from April until June 2015. There were 41 children with sepsis. Sepsis was diagnosed from clinical and laboratory findings. Complete blood count, antithrombin III level, C-reactive protein and procalcitonin were an indicator of unproven sepsis that performed in the laboratory. Meanwhile blood culture was performed in the microbiology laboratory. The association between the level of antithrombin III and mortality was analysed by using chi-square test.

RESULTS

Of the 41 participants, the low antithrombin III level was 13 of 41 children (31.7%) meanwhile the normal antithrombin III level was 28 of 41 children (68.3%). There was 8 of 13 (42.1%) and 11 of 28 (57.9%) children in death cases of low and normal antithrombin III level, respectively. Samples with low antithrombin III level had 2.473 higher risk mortality than normal antithrombin III level (P = 0.184; 95% CI 0.641 to 9.5421; PR = 2.473).

CONCLUSION

There was no statistically significant association between levels of antithrombin III and mortality in children with sepsis.

Accuracy of presepsin in neonatal sepsis: systematic review and meta-analysis

INTRODUCTION

Neonatal sepsis represents a major cause of morbidity and mortality in neonates. No diagnostic test has been demonstrated to be sufficiently accurate to confirm or exclude neonatal sepsis. This study aimed to evaluate the diagnostic accuracy of presepsin (P-SEP) for neonatal sepsis. Areas covered: A systematic review of literature was performed on Medline and EMBASE. A meta-analysis was performed to calculate pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic of P-SEP for neonatal sepsis. Eight studies were included, involving 636 neonates. Pooled sensitivity and specificity were 0.90 and 0.90, respectively. The pooled DOR was 120.94, and the Area Under Curve (AUC) was 0.968, indicating a high level of diagnostic accuracy. Using cut-off values <600 ng/L, sensitivity reached 0.93, with a specificity of 0.81 and AUC 0.8195, while using a threshold >600 ng/L, sensitivity was 0.87 and specificity 0.97, with higher diagnostic accuracy (AUC 0.976). Significant heterogeneity was found between studies. Expert commentary: Diagnostic accuracy of P-SEP resulted high in detecting neonatal sepsis. Even though it cannot be recommended as a single diagnostic test, P-SEP could be a helpful and valuable biomarker in neonates with suspected sepsis.

Can Base Excess be Used for Prediction to Early Diagnosis of Neonatal Sepsis in Preterm Newborns?

Background

Neonatal sepsis remains an important and potentially life-threatening clinical syndrome and a major cause of neonatal mortality and morbidity. The aim of this study to investigate whether values of base excess before the onset of clinical signs and symptoms of sepsis indicate infection in the early diagnosis of neonatal sepsis.

Methods

In this study, a total of 118 infants were enrolled. The infants were classified into two groups: group 1 (sepsis, n=49) and group 2 (control, n=69). Blood gas analysis investigated for the screening of neonatal sepsis.

Results

A total of 49 newborns with neonatal sepsis and 69 healthy controls were enrolled. Comparison of markers of sepsis revealed C-reactive protein, interleukin-6 level to be significantly higher and pH, pCO₂, HCO_3, and base excess values to be significantly lower in newborns with sepsis compared healthy controls (p<0.01). The optimum cut-off value in the diagnosis of neonatal sepsis was found to be -5 mmol/L for base excess. Sensitivity, specificity, positive predictive value and negative predictive value of this base excess cut-off for neonatal sepsis were 75, 91, 86 and 84% respectively.

Conclusion

This is the first study to determine the relationship between the decreased value of the base excess and early stage of neonatal sepsis. If the value of base excess <-5 mmol/L without an underlying another reason, may need close follow up of infants for neonatal sepsis and it may help early diagnosis.

Blood culture indications in critically ill neonates: a multicenter prospective cohort study

Due to potential lethality of healthcare-associated sepsis (HAS), a low threshold for blood culturing and antimicrobial therapy (ABT) initiation is accepted. We assessed variability in the trigger for blood culturing between three neonatal intensive care units. A multicenter prospective cohort study was conducted. In newborns with suspicion of HAS, 10 predefined clinical signs, nosocomial sepsis (NOSEP) score, C-reactive protein, ABT initiation, and risk factors were registered at time of culturing. Outcome was lab-confirmed HAS, defined according to the NeoKISS-criteria. Two hundred ninety-nine suspected HAS episodes were considered in 212 infants, of which 118 had birth-weight ≤ 1500 g; proportion of lab-confirmed HAS per suspected episode was 30/192 (center 1), 28/60 (center 2), and 8/47 (center 3) (p < 0.001). Median C-reactive protein and number of clinical signs at time of culturing differed between centers 1, 2, and 3 (respectively 11 vs. 5 vs. 3 mg/L, p = 0.001; 1 sign [IQR 0-2, center 1] vs. 3 signs [IQR 2-4, centers 2 and 3], p < 0.001). Median NOSEP score at time of culturing was 5 (IQR 3-8, center 1), 5 (IQR 3-9, center 2), and 8 (IQR 5-11, center 3) (p = 0.016). Difference in ABT initiation was noticed (82 vs. 93 vs. 74%, p = 0.05).

CONCLUSION

Center heterogeneity in sampling practice is substantial. Optimizing sampling practice can be recommended. What is Known: • Blood culture test is a common diagnostic procedure in critically-ill newborns. • A low threshold for sampling and antimicrobial therapy initiation is accepted. What is New: • Variability in blood culture practice was assessed between 3 neonatal intensive care units by the registration of sampling frequencies, clinical indications, and antimicrobial therapy initiation.

Clinical Significance of Interleukin-6 in the Diagnosis of Sepsis and Discriminating Sepsis Induced by Gram-negative Bacteria

BACKGROUND

To discuss the clinical significance of interleukin (IL)-6 in the differential diagnosis of sepsis and its capability of differentiating the sepsis induced by Gram-negative bacteria from that induced by Gram-positive bacteria.

METHODS

A total of 379 children with sepsis were involved in this study to form the case group, and their C-reactive protein (CRP), procalcitonin (PCT) and IL-6 levels before antibiotics and after recovery were checked. Receiver operating characteristic curve was applied to evaluate the significance of CRP, PCT and IL-6 in the differential diagnosis of sepsis and their capability of differentiating the sepsis induced by Gram-negative bacteria from that induced by Gram-positive bacteria.

RESULTS

When these 3 indicators were applied to the differential diagnosis of sepsis, the area under the curve (AUC) of IL-6, PCT and CRP was 0.881, 0.877 and 0.754, respectively. The combination of IL-6 and PCT presented highest diagnostic efficiency. CRP, PCT and IL-6 levels in children with sepsis induced by Gram-negative bacteria were significantly higher than those in children with sepsis induced by Gram-positive bacteria.

CONCLUSIONS

CRP, IL-6 and PCT are applicable to the differential diagnosis of sepsis and differentiating the sepsis induced by Gram-negative bacteria from Gram-positive bacteria. Appropriate combinations of these indicators are capable of increasing differential diagnosis efficiency. These indicators can be used as markers of antibiotics usage, but whether they can be used as markers to withdraw antibiotics is still needed to be observed.

Early detection of neonatal group B streptococcus sepsis and the possible diagnostic utility of IL-6, IL-8, and CD11b in a human umbilical cord blood in vitro model

Background

Group B streptococcus (GBS) infection remains a major cause of neonatal morbidity and mortality, and GBS III is the predominant strain in early-onset GBS neonatal sepsis. To avoid both over- and undertreatment of infants with nonspecific signs of infection, early diagnostic tools are warranted. The aim of this study was to identify biomarkers with high sensitivity and specificity in an early stage of GBS infection. A secondary aim was to assess the utility of a human umbilical cord blood (HUCB) model system of early-onset neonatal sepsis.

Methods

Umbilical cord blood samples from 20 healthy term pregnancies were stimulated for 2 hours with a GBS III isolate from a patient and a commercially available GBS Ia strain. Nonstimulated samples served as controls. Leukocyte surface markers (CD11b, CD64, toll-like receptor [TLR] 2, TLR4, and TLR6) were analyzed by flow cytometry and soluble biomarkers by enzyme-linked immunosorbent assay (interleukin [IL]-6 and -8; interferon-γ-inducing protein [IP]-10; and S100b). The area under the receiver operating characteristic curve (AUC) was calculated for the markers.

Results

GBS III gave the highest responses and AUC values for all biomarkers. Only IL-6 and IL-8 displayed an AUC approaching 0.8 for both GBS serotypes (P<0.001). IL-8 >5,292 pg/mL had both a sensitivity and a specificity of 1.00. IL-6 >197 pg/mL had both a sensitivity and a specificity of 0.95 for GBS III stimulation. CD11b on granulocytes and monocytes was the leukocyte surface marker with the highest AUC values for both GBS serotypes.

Conclusion

In agreement with previous studies, IL-6, IL-8, and potentially CD11b could be useful in diagnosing neonatal GBS infection in an early stage. Our HUCB early-onset neonatal sepsis model may be useful for evaluating biomarkers of neonatal sepsis. The HUCB of neonates with risk factors for sepsis might even be used for diagnostic purposes, but requires further study.

Inflammatory Response in Preterm and Very Preterm Newborns with Sepsis

The response of the adaptive immune system is usually less intense in premature neonates than term neonates. The primary objective of this study was to determine whether immunological parameters vary between preterm (PT) neonates (≥32 weeks of gestational age) and very preterm (VPT) neonates (<32 weeks of gestational age). A cross-sectional study was designed to prospectively follow PT and VPT neonates at risk of developing sepsis. Plasma concentrations of IFN-γ, TNF-α, IL-6, IL-4, and IL-10 were detected using flow cytometry. C-reactive protein (C-RP) and the complex SC5b-9 were detected in the plasma using commercial kits. A total of 83 patients were included. The laboratory results and clinical histories showed that 26 patients had sepsis; 14 were VPT, and 12 were PT. The levels of C-RP, SC5b-9 (innate immune response mediators), and IL-10 or IL-4 (anti-inflammatory cytokines) were elevated during sepsis in both groups. IFN-γ, TNF-α, and IL-6 (proinflammatory cytokines) were differentially elevated only in PT neonates. The VPT neonates with sepsis presented increases in C-RP, SC5b-9, and anti-inflammatory cytokines but not in proinflammatory cytokines, whereas PT neonates showed increases in all studied mediators of inflammation.

Evaluation of IL-6, CRP and hs-CRP as Early Markers of Neonatal Sepsis

INTRODUCTION

Bacterial sepsis is a life threatening crisis with high mortality and morbidity in neonates. Due to non-specific clinical presentation, diagnosis of sepsis is still a challenge. It can be diagnosed by blood culture but it is time consuming. So, a reliable marker is needed for the diagnosis of neonatal sepsis so that early treatment can be initiated. Various cytokines, chemokines, acute phase reactants, cell surface markers and interferons have been evaluated to find out the effective marker for early diagnosis of neonatal sepsis. In this study, levels of IL-6, CRP and hs-CRP have been analysed which would favour the diagnosis of neonatal sepsis.

AIM

This study aimed to detect the levels of IL-6, CRP and hs-CRP in clinically suspected cases of neonatal sepsis and to evaluate and analyze the above parameters as the early markers of neonatal sepsis in comparison with blood culture.

MATERIALS AND METHODS

Eighty neonates were included in this study of which 40 were clinically suspected cases of neonatal sepsis who met the inclusion criteria and the other 40 were normal healthy neonates that were taken as controls. After obtaining written informed consent from either parent of all neonates, venous blood samples were collected. Blood culture was performed by conventional method. Estimation of serum IL-6 was done by ELISA method and serum CRP and hs-CRP were done by immunofluorescence assay.

RESULTS

The CRP level >13.49 mg/l showed sensitivity and specificity of 80% and 65.70% respectively. The IL-6 >51.29 pg/ml showed sensitivity of 100% and specificity of 62.86% and hs-CRP showed sensitivity of 90% and specificity of 32.86%. Combination of IL-6 and CRP showed sensitivity and specificity of 100% and 75.71% respectively.

CONCLUSION

Our study suggests that IL-6 is a highly sensitive marker and CRP is a more specific marker for the diagnosis of neonatal sepsis. hs-CRP is a less reliable marker. So, the combination of IL-6 and CRP are the better predictors of neonatal sepsis.

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.