Diagnostic utility of biomarkers for neonatal sepsis--a systematic review

Assessment of Serum Interleukin-27 and Mean Platelet Volume in Late-Onset Neonatal Sepsis

OBJECTIVE

Late-onset sepsis (LOS) is a substantial contributor to morbidity and mortality among neonates. The use of nonculture-based tools for early diagnosis is an area of active investigation. Therefore, we aimed to evaluate the diagnostic value of serum interleukin-27 (IL-27) and mean platelet volume (MPV) in full-term neonates with LOS.

STUDY DESIGN

In this single-center, cross-sectional study, 90 full-term newborns were assigned to two equal-matched groups as follows: (1) culture-proven sepsis and (2) control groups. Clinical data and laboratory findings as complete blood pictures, including MPV, highly sensitive C-reactive protein, and blood culture results, were recorded. Moreover, IL-27 levels were measured using enzyme-linked immunosorbent assay.

RESULTS

IL-27 levels (median = 4,364 pg/mL) and MPV (mean = 12.02 ± 1.54 FL) were significantly higher in the culture-proven sepsis group than in the control group (p < 0.001). For IL-27, the optimum cut-off value for the diagnosis of LOS was 283.8 pg/mL with sensitivity and specificity of 97.8 and 100%, respectively. For MPV, the optimum cut-off value was 11.6 FL, with diagnostic sensitivity and specificity of 77.8 and 97.8%, respectively.

CONCLUSION

IL-27 and MPV are promising markers for the diagnosis of LOS in full-term neonates. The diagnostic performance of IL-27 was superior to MPV.

KEY POINTS

· Late-onset neonatal sepsis diagnosis is time consuming.. · Nonculture-based rapid diagnostic tests are much needed.. · IL-27 is superior in LOS diagnosis to MPV..

Impact of Physician Characteristics on Late-Onset Sepsis (LOS) Evaluation in the NICU

The threshold for a late-onset sepsis (LOS) evaluation varies considerably across NICUs. This unexplained variability is probably related in part to physician bias regarding when sepsis should be "ruled out". The aim of this study is to determine if physician characteristics (race, gender, immigration status, years of experience and academic rank) effect LOS evaluation in the NICU. This study includes a retrospective chart review of all Level III NICU infants who had a LOS evaluation over 54 months. Physician characteristics were compared between positive and negative blood culture groups and whether CBC and CRP were obtained at LOS evaluations. There were 341 LOS evaluations performed during the study period. Two patients were excluded due to a contaminant. Patients in this study had a birth weight of [median (Q1, Q3)]+ 992 (720, 1820) grams and birth gestation of [median (Q1, Q3)] 276/7 (252/7, 330/7) weeks. There are 10 neonatologists in the group, 5/10 being female and 6/10 being immigrant physicians. Experienced physicians were more likely to obtain a CBC at the time of LOS evaluation. Physician characteristics of race, gender and immigration status impacted whether to include a CRP as part of a LOS evaluation but otherwise did not influence LOS evaluation, including the likelihood of bacteremia.

Clinical Decision Support for Improved Neonatal Care: The Development of a Machine Learning Model for the Prediction of Late-onset Sepsis and Necrotizing Enterocolitis

OBJECTIVE

To develop an artificial intelligence-based software system for predicting late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) in infants admitted to the neonatal intensive care unit (NICU).

STUDY DESIGN

Single-center, retrospective cohort study, conducted in the NICU of the Antwerp University Hospital. Continuous monitoring data of 865 preterm infants born at <32 weeks gestational age, admitted to the NICU in the first week of life, were used to train an XGBoost machine learning (ML) algorithm for LOS and NEC prediction in a cross-validated setup. Afterward, the model's performance was assessed on an independent test set of 148 patients (internal validation).

RESULTS

The ML model delivered hourly risk predictions with an overall sensitivity of 69% (142/206) for all LOS/NEC episodes and 81% (67/83) for severe LOS/NEC episodes. The model showed a median time gain of ≤10 hours (IQR, 3.1-21.0 hours), compared with historical clinical diagnosis. On the complete retrospective dataset, the ML model made 721 069 predictions, of which 9805 (1.3%) depicted a LOS/NEC probability of ≥0.15, resulting in a total alarm rate of <1 patient alarm-day per week. The model reached a similar performance on the internal validation set.

CONCLUSIONS

Artificial intelligence technology can assist clinicians in the early detection of LOS and NEC in the NICU, which potentially can result in clinical and socioeconomic benefits. Additional studies are required to quantify further the effect of combining artificial and human intelligence on patient outcomes in the NICU.

Investigating the Association between Serum and Hematological Biomarkers and Neonatal Sepsis in Newborns with Premature Rupture of Membranes: A Retrospective Study

(1) Background: Neonatal early-onset sepsis (EOS) is associated with important mortality and morbidity. The aims of this study were to evaluate the association between serum and hematological biomarkers with early onset neonatal sepsis in a cohort of patients with prolonged rupture of membranes (PROM) and to calculate their diagnostic accuracy. (2) Methods: A retrospective cohort study was conducted on 1355 newborns with PROM admitted between January 2017 and March 2020, who were divided into two groups: group A, with PROM ≥ 18 h, and group B, with ROM < 18 h. Both groups were further split into subgroups: proven sepsis, presumed sepsis, and no sepsis. Descriptive statistics, analysis of variance (ANOVA) and a Random Effects Generalized Least Squares (GLS) regression were used to evaluate the data. (3) Results: The statistically significant predictors of neonatal sepsis were the high white blood cell count from the first (p = 0.005) and third day (p = 0.028), and high C-reactive protein (CRP) values from the first day (p = 0.004). Procalcitonin (area under the curve-AUC = 0.78) and CRP (AUC = 0.76) measured on the first day had the best predictive performance for early-onset neonatal sepsis. (4) Conclusions: Our results outline the feasibility of using procalcitonin and CRP measured on the first day taken individually in order to increase the detection rate of early-onset neonatal sepsis, in the absence of positive blood culture.

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.

Inflammation, sepsis severity and neurodevelopmental outcomes of late-onset sepsis in preterm neonates

BACKGROUND

The aim of this study was to investigate the association between inflammatory biomarkers (C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6)) and sepsis severity (neonatal-Sequential-Organ-Failure-Assessment (nSOFA)) and neurodevelopmental outcomes at 2 years, among very preterm neonates.

METHODS

Data on preterm neonates (gestational age <30 weeks) from 2016 until 2020 were reviewed. Outcomes of interest were NDI (no, mild, severe) and the motor and cognitive score on the Dutch-Bayley-Scales-of-Infant-and-Toddler-Development (Bayley-III-NL) assessed at the corrected age of 2 years. Logistic and linear regression analysis were used for categorical and continuous outcomes, respectively. All analyses were adjusted for gestational age, sex and birthweight-for-gestational-age SD-score.

RESULTS

In total 410 patients were eligible for analysis. Maximum CRP concentrations were associated with lower motor and cognitive scores (effect estimate -0.03 points,(95% CI -0.07; -0.00) and -0.03 points,(95% CI -0.06; -0.004), respectively) and increased risk of severe NDI (odds ratio (OR) 1.01, (95% CI 1.00; 1.01)). High nSOFA scores (≥4) during sepsis episodes were associated with an increased risk of mild NDI (OR 2.01, (95% CI 1.34; 3.03)). There were no consistent associations between IL-6, PCT and the outcomes of interest.

CONCLUSION

High CRP concentrations and sepsis severity in preterm neonates seem to be associated with neurodevelopmental outcomes in survivors at the age of 2 years.

IMPACT STATEMENT

The level of inflammation and sepsis severity are associated with neurodevelopmental outcome in preterm neonates at 2 years of corrected age. Sepsis is a major health issue in preterm neonates and can lead to brain damage and impaired neurodevelopment. Biomarkers can be determined to assess the level of inflammation. However, the relation of inflammatory biomarkers with neurodevelopmental outcome is not known. The level of inflammation and sepsis severity are related to neurodevelopmental outcome in preterm neonates. Maximum CRP concentration and high nSOFA scores are associated with an increased risk of neurodevelopmental impairment in survivors at the corrected age of 2 years.

Advancement in biomarker based effective diagnosis of neonatal sepsis

Neonatal sepsis is considered as alarming medical emergency and becomes the common global reason of neonatal mortality. Non-specific symptoms and limitations of conventional diagnostic methods for neonatal sepsis mandate fast and reliable method to diagnose disease for point of care application. Recently, disease specific biomarkers have gained interest for rapid diagnosis that led to the development of electrochemical biosensor with enhanced specificity, sensitivity, cost-effectiveness and user-friendliness. Other than conventional biomarker C-reactive protein to diagnose neonatal sepsis, several potential biomarkers including Procalcitonin (PCT), Serum amyloid A (SAA) and other candidates are extensively investigated. The present review provides insights on advancements and diagnostic abilities of protein and nucleotide based biomarkers with their incorporation in developing electrochemical biosensors by employing novel fabrication strategies. This review provides an overview of most promising biomarker and its capability for neonatal sepsis diagnosis to fulfil future demand to develop electrochemical biosensor for point-of-care applications.

miRNAs: novel noninvasive biomarkers as diagnostic and prognostic tools in neonatal sepsis

The study aimed to assess the diagnostic and prognostic value of 3 specific microRNAs (miRNAs) in early-onset neonatal sepsis (NS). We examined miR-1, miR-124, and miR-34a in 70 NS patients upon admission and compared them to 70 healthy controls by RT-PCR. The main finding of the study was the difference in miRNA expression levels between NS patients and controls. Higher expression levels of miR-1 and miR-124 were significantly associated with NS, while miR-34a expression was reduced. Among the studied miRNAs, miR-34a exhibited the highest specificity (97%) as a confirmatory test for NS. In the multivariate model, miR-1 and miR-124 were found to be significant predictors of disease progression or mortality. Overall, the study suggests that miR-1, miR-124, and miR-34a could serve as potential biomarkers for diagnosing and predicting outcomes in early-onset NS.

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.

Diagnostic Performance and Patient Outcomes With C-Reactive Protein Use in Early-Onset Sepsis Evaluations

OBJECTIVES

To determine performance of C-reactive protein (CRP) in the diagnosis of early-onset sepsis, and to assess patient outcomes with and without routine use of CRP.

STUDY DESIGN

This was a retrospective cohort study of infants admitted to 2 neonatal intensive care units. CRP was used routinely in early-onset sepsis evaluations during 2009-2014; this period was used to determine CRP performance at a cut-off of ≥10 mg/L in diagnosis of culture-confirmed early-onset sepsis. Routine CRP use was discontinued during 2018-2020; outcomes among infants admitted during this period were compared with those in 2012-2014.

RESULTS

From 2009 to 2014, 10 134 infants were admitted; 9103 (89.8%) had CRP and 7549 (74.5%) had blood culture obtained within 3 days of birth. CRP obtained ±4 hours from blood culture had a sensitivity of 41.7%, specificity 89.9%, and positive likelihood ratio 4.12 in diagnosis of early-onset sepsis. When obtained 24-72 hours after blood culture, sensitivity of CRP increased (89.5%), but specificity (55.7%) and positive likelihood ratio (2.02) decreased. Comparing the periods with (n = 4977) and without (n = 5135) routine use of CRP, we observed lower rates of early-onset sepsis evaluation (74.5% vs 50.5%), antibiotic initiation (65.0% vs 50.8%), and antibiotic prolongation in the absence of early-onset sepsis (17.3% vs 7.2%) in the later period. Rate and timing of early-onset sepsis detection, transfer to a greater level of care, and in-hospital mortality were not different between periods.

CONCLUSIONS

CRP diagnostic performance was not sufficient to guide decision-making in early-onset sepsis. Discontinuation of routine CRP use was not associated with differences in patient outcomes despite lower rates of antibiotic administration.

The Role of Coagulase-Negative Staphylococci Biofilms on Late-Onset Sepsis: Current Challenges and Emerging Diagnostics and Therapies

Infections are one of the most significant complications of neonates, especially those born preterm, with sepsis as one of the principal causes of mortality. Coagulase-negative staphylococci (CoNS), a group of staphylococcal species that naturally inhabit healthy human skin and mucosa, are the most common cause of late-onset sepsis, especially in preterms. One of the risk factors for the development of CoNS infections is the presence of implanted biomedical devices, which are frequently used for medications and/or nutrient delivery, as they serve as a scaffold for biofilm formation. The major concerns related to CoNS infections have to do with the increasing resistance to multiple antibiotics observed among this bacterial group and biofilm cells’ increased tolerance to antibiotics. As such, the treatment of CoNS biofilm-associated infections with antibiotics is increasingly challenging and considering that antibiotics remain the primary form of treatment, this issue will likely persist in upcoming years. For that reason, the development of innovative and efficient therapeutic measures is of utmost importance. This narrative review assesses the current challenges and emerging diagnostic tools and therapies for the treatment of CoNS biofilm-associated infections, with a special focus on late-onset sepsis.

The accuracy of soluble urokinase-type plasminogen activator receptor for the diagnosis of neonatal sepsis: a meta-analysis

Background

Neonatal sepsis is one of the major causes of morbidity and mortality in newborns. However, atypical clinical manifestations and symptoms make the early diagnosis of neonatal sepsis a challenge. Relatively high-serum soluble urokinase-type plasminogen activator receptor (suPAR) has been implicated as a diagnostic biomarker for adult sepsis. Therefore, the meta-analysis is intended to explore the diagnostic value of suPAR for neonatal sepsis.

Methods

The PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, China Biological Medicine Disk, and Wanfang databases were retrieved from inception to 31 December 2022 to collect diagnostic accuracy studies about suPAR for neonatal sepsis. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias in the included studies using the quality assessment of diagnostic accuracy studies-2 (QUADAS-2) tool. Then, a meta-analysis was performed using Stata 15.0 software.

Results

A total of six articles involving eight studies were included. The results of the meta-analysis showed that the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.89 [95%CI (0.83-0.93)], 0.94 [95%CI (0.77-0.98)], 14 [95%CI (3.5-55.2)], 0.12 [95%CI (0.08-0.18)], and 117 [95%CI (24-567)], respectively. The area under the curve (AUC) of summary receiver operator characteristic (SROC) curves was 0.92 [95%CI (0.90-0.94)]. Sensitivity analysis confirmed the stability of the results, and publication bias was not observed. Fagan's nomogram results demonstrated the clinical availability of the findings.

Conclusion

Current evidence suggests that suPAR has potential diagnostic value for neonatal sepsis. Owing to the limited quality of the included studies, more high-quality studies are needed to verify the above conclusion.

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.

A nomogram for predicting the development of serious bacterial infections in febrile term neonates: A single medical center experience in Southern Taiwan

BACKGROUND

Serious bacterial infections (SBIs) could lead to mortality or severe long-term sequelae in neonates and infants aged <3 months. Accordingly, the aim of this study was to develop a quantitative and accurate assessment tool for predicting the risk of SBIs in febrile neonates.

METHODS

This retrospective study enrolled 131 febrile term neonates (aged <30 days) who were hospitalized at Kaohsiung Veterans General Hospital between January 2005 and December 2020. These neonates were classified into SBI and nonbacterial infection (NBI) groups on the basis of microbiological laboratory reports. The clinical characteristics and routine blood tests of both groups at the time of admission were analyzed. Stepwise logistic regression was applied to create and validate the nomogram for SBI prediction.

RESULTS

Among the 131 febrile neonates, 38 and 93 developed SBIs and NBIs, respectively. At the time of admission, ill clinical appearance, serum myelocyte/metamyelocyte presence, C-reactive protein (CRP) > 2.5 mg/dL, and pyuria were associated with an increased risk of SBIs. Accordingly, these four factors were used to develop a nomogram for SBI prediction, which exhibited significantly high performance (area under curve = 0.848, p < 0.001) in predicting SBI risk.

CONCLUSION

We developed a nomogram combining clinical appearance, serum myelocyte/metamyelocyte presence, CRP, and pyuria for predicting SBI risk in febrile neonates. This tool can assist clinicians in making early diagnoses and delivering the appropriate treatment.

Early-Onset Neonatal Sepsis in Low- and Middle-Income Countries: Current Challenges and Future Opportunities

Neonatal sepsis is defined as a systemic infection within the first 28 days of life, with early-onset sepsis (EOS) occurring within the first 72h, although the definition of EOS varies in literature. Whilst the global incidence has dramatically reduced over the last decade, neonatal sepsis remains an important cause of neonatal mortality, highest in low- and middle-income countries (LMICs). Symptoms at the onset of neonatal sepsis can be subtle, and therefore EOS is often difficult to diagnose from clinical presentation and laboratory testing and blood cultures are not always conclusive or accessible, especially in resource limited countries. Although the World Health Organisation (WHO) currently advocates a ß-lactam, and gentamicin for first line treatment, availability and cost influence the empirical antibiotic therapy administered. Antibiotic treatment of neonatal sepsis in LMICs is highly variable, partially caused by factors such as cost of antibiotics (and who pays for them) and access to certain antibiotics. Antimicrobial resistance (AMR) has increased considerably over the past decade and this review discusses current microbiology data available in the context of the diagnosis, and treatment for EOS. Importantly, this review highlights a large variability in data availability, methodology, availability of diagnostics, and aetiology of sepsis pathogens.

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.

MicroRNA Expression in Neonates with Late-onset Sepsis - A Cross-sectional Comparative Study

BACKGROUND

Neonatal sepsis is a major health concern among neonates with higher morbidity and mortality rate. Studies have recently speculated the importance of differential expression of circulating mature micro-RNAs (miRNAs) which could serve as diagnostic as well as prognostic markers for risk of mortality in neonatal sepsis. This study aimed to analyze the expression pattern and to assess the diagnostic/prognostic value of miRNAs miR-21, miR-29a miR-31, miR-146a, and miR-155 in late-onset neonatal sepsis.

METHODS

A cross-sectional comparative study was conducted including 42 healthy controls and 42 neonates with late-onset neonatal sepsis. SYBR green-based miScript RT-PCR assay was used for the expression analysis and the comparative Ct method 2-delta (Ct) method was used for relative quantification of the candidate miRNAs in plasma. Significantly higher expression of miR-21 and miR-155 and lower expression of miR-29a and miR-146a was observed in cases compared to control except miR-31. In subgroups analysis, miR-21(p = .03) showed a significant difference between pre-term and term neonates and miR-31 (p = .01) and miR-155 (p = .03) showed a significant difference between low-birth-weight and normal-birth-weight neonates. miR-146a showed significantly lower expression in the non-survivor group compared to the survivor group (p = .005). A receiver operating characteristic curve (ROC) analysis of miR-21 and miR-29a (0.829 and 0.787 AUC of ROC curves) showed good discrimination for the identification of sepsis from non-sepsis neonates.

CONCLUSION

The current study shows evidence of differential expression of miRNAs in neonatal sepsis and this altered expression of candidate miRNAs could be involved in immune dysregulation, thus leading to sepsis-related severity in newborns.

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.

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.

Antibiotic stewardship in NICU: De-implementing routine CRP to reduce antibiotic usage in neonates at risk for early-onset sepsis

OBJECTIVE

Antibiotic overuse is common in the neonatal intensive care units (NICUs). We evaluated the change in antibiotic utilization rate (AUR) by eliminating routine CRP in the management of early-onset sepsis (EOS).

METHODS

Retrospective before-after cohort study in a Level 3B NICU. We made the following practice changes in the management of EOS: (1) stop routine CRP and (2) implement an automatic stop order (ASO) for antibiotics at 48 h. We compared the AUR, defined as any antibiotic use per 1000 patient days before and after practice change.

RESULT

There was an absolute reduction of 30% in AUR and a decrease in the proportion of neonates receiving antibiotics from the day of life 3-6 in postintervention period. We did not identify any case of partially treated EOS with change in practice.

CONCLUSION

Elimination of routine CRP and ASO implementation for antibiotics in neonates at risk for EOS decreased AUR.

Interleukin-6 as a Biomarker of Early-Onset Neonatal Sepsis

OBJECTIVE

The aim of this study is to determine the utility of C reactive protein (CRP) and interleukin (IL)-6 in the diagnosis of neonatal sepsis (NS) in a neonatal intensive care unit (NICU) in the south of Colombia.

STUDY DESIGN

A nonmatched case-control study was conducted. Convenience sampling was performed. Data were obtained from clinical records. IL-6 levels were determined using enzyme-linked immunosorbent assay. Receiver operator characteristic (ROC) curve analysis and Youden's index were used to determine the optimal cutoffs for CRP and IL-6 levels in diagnosing NS, early-onset NS (EONS), and late-onset NS (LONS).

RESULTS

Data from 31 cases and 62 controls were included. History of chorioamnionitis (infinite odds ratio [OR] [3.07-infinity]), and the presence of meconium-stained amniotic fluid during birth (OR: 9.04 [1.35-112]) were identified as risk factors for NS. Differences in CRP (p < 0.0001) and IL-6 (p < 0.0485) levels were also found, more significantly for LONS and EONS patients, respectively. In the diagnosis of LONS using CRP levels, the area under the ROC curve (AUC) was 0.8371 (p < 0.0001). The optimal cutoff was 0.53 mg/dL. For EONS diagnosis using IL-6, the AUC was 0.6869 (p = 0.0315) and the optimal cutoff was 17.75 pg/mL.

CONCLUSION

Differences between CRP and IL-6 levels were found between control and NS groups. Furthermore, CRP showed greater potential diagnostic utility in the LONS group, whereas IL-6 showed greater potential utility in the EONS group.

KEY POINTS

· NS is a major morbimortality cause worldwide. · CRP and IL-6 levels may be useful NS biomarkers. · No biomarker alone is enough for the diagnosis of NS.

López E, Álvarez R, Aung MS, Kobayashi N, Quiñones D. Characterization of Neonatal Infections by Gram-Negative Bacilli and Associated Risk Factors, Havana, Cuba

Infections represent an important problem in neonates because of the high mortality. An increase in neonatal infections has been found in Cuban hospitals in recent years. The aim of this study was to provide evidence on the clinical and microbiological behavior of Gram-negative bacilli that cause neonatal infections in hospitals of Havana, Cuba. It was carried out as a descriptive cross-sectional investigation from September 2017 to July 2018 in The Tropical Medicine Institute "Pedro Kouri" (IPK). Sixty-one Gram-negative bacilli isolated from neonates with infections in six Gyneco-Obstetric and Pediatric Hospitals of Havana were analyzed for their species and antimicrobial susceptibility. Late-onset infections were more common than early-onset ones and included urinary tract infection in the community (87%) and sepsis in hospitals (63.3%). Catheter use (47%) and prolonged stay (38%) were the most frequent risk factors. Species of major pathogens were Escherichia coli (47%) and Klebsiella spp. (26%). The isolated Gram-negative bacilli showed high resistance rates to third-generation cephalosporins, ciprofloxacin and gentamicin, while being more susceptible to carbapenems, fosfomycin, colistin and amikacin. The present study revealed the clinical impact of Gram-negative bacilli in neonatology units in hospitals of Havana. Evaluation of antimicrobial susceptibilities to the isolates from neonates is necessary for selection of appropriate empirical therapy and promotion of the rational antibiotic use.

DNA Methylation Analysis to Unravel Altered Genetic Pathways Underlying Early Onset and Late Onset Neonatal Sepsis. A Pilot Study

Background: Neonatal sepsis is a systemic condition widely affecting preterm infants and characterized by pro-inflammatory and anti-inflammatory responses. However, its pathophysiology is not yet fully understood. Epigenetics regulates the immune system, and its alteration leads to the impaired immune response underlying sepsis. DNA methylation may contribute to sepsis-induced immunosuppression which, if persistent, will cause long-term adverse effects in neonates.

Objective: To analyze the methylome of preterm infants in order to determine whether there are DNA methylation marks that may shed light on the pathophysiology of neonatal sepsis.

Design: Prospective observational cohort study performed in the neonatal intensive care unit (NICU) of a tertiary care center.

Patients: Eligible infants were premature ≤32 weeks admitted to the NICU with clinical suspicion of sepsis. The methylome analysis was performed in DNA from blood using Infinium Human Methylation EPIC microarrays to uncover methylation marks.

Results: Methylation differential analysis revealed an alteration of methylation levels in genomic regions involved in inflammatory pathways which participate in both the innate and the adaptive immune response. Moreover, differences between early and late onset sepsis as compared to normal controls were assessed.

Conclusions: DNA methylation marks can serve as a biomarker for neonatal sepsis and even contribute to differentiating between early and late onset sepsis.

Potential role of IFN-γ and IL-5 in sepsis prediction of preterm neonates

Not fully maturated immune system in preterm neonates may contribute to the increased susceptibility to infection. The levels of some cytokines can be useful in the prediction and diagnosis of sepsis in premature neonates. In the present study, we evaluated the potential predictive role of IFN-γ and IL-5 in cord and venous blood, together with the determination of C-reactive protein and procalcitonin (PCT) for sepsis development in premature neonates. A total of 80 participants were included. The laboratory results and clinical histories showed that 21 participants had sepsis. Early onset sepsis was detected in 3 patients while late onset sepsis was observed in 18 participants. The venous plasma levels of IFN-γ and PCT was markedly increased in sepsis groups when compared to the participants without sepsis. On the other hand, levels of IL-5 did not significantly change in the evaluated groups of sepsis and in the control group of participants. Simultaneously, plasma venous levels were not altered in any of the evaluated groups. Obtained findings suggest that venous plasma levels of IFN-γ, rather than levels of IFN-γ in cord blood plasma, and PCT may have predictive potential for sepsis development in preterm neonates. Further studies are necessary to get more comprehension of the complex function of cytokines for sepsis development in preterm neonates.

Neonatal Sepsis: A Review of Pathophysiology and Current Management Strategies

BACKGROUND

Early-onset sepsis, occurring within 72 hours of birth, and late-onset sepsis, occurring after this time period, present serious risks for neonates. While culture-based screening and intrapartum antibiotics have decreased the number of early-onset cases, sepsis remains a top cause of neonatal morbidity and mortality in the United States.

PURPOSE

To provide a review of neonatal sepsis by identifying its associated risk factors and most common causative pathogens, reviewing features of the term and preterm neonatal immune systems that increase vulnerability to infection, describing previous and the most current management recommendations, and discussing relevant implications for the neonatal nurse and novice neonatal nurse practitioner.

METHODS/SEARCH STRATEGY

An integrative review of literature was conducted using key words in CINAHL, Google Scholar, and PubMed.

FINDINGS/RESULTS

Group B streptococcus and Escherichia coli are the most common pathogens in early-onset sepsis, while Coagulase-negative staphylococci comprise the majority of cases in late-onset. The neonatal immune system is vulnerable due to characteristics including decreased cellular activity, underdeveloped complement systems, preferential anti-inflammatory responses, and insufficient pathogenic memory. Blood cultures remain the criterion standard of diagnosis, with several other adjunct tests under investigation for clinical use. The recent development of the sepsis calculator has been a useful tool in the management of early-onset cases.

IMPLICATIONS FOR PRACTICE

It is vital to understand the mechanisms behind the neonate's elevated risk for infection and to implement evidence-based management.

IMPLICATIONS FOR RESEARCH

Research needs exist for diagnostic methods that deliver timely and sensitive results. A tool similar to the sepsis calculator does not exist for preterm infants or late-onset sepsis, groups for which antibiotic stewardship is not as well practiced.Video Abstract available athttps://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?autoPlay=false&videoId=40.

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.

Association of Routinely Measured Proinflammatory Biomarkers With Abnormal MRI Findings in Asphyxiated Neonates Undergoing Therapeutic Hypothermia

Background: The neuroprotective treatment effect of therapeutic hypothermia (TH) following perinatal asphyxia may be negatively influenced by neonatal sepsis and concomitant inflammation. We aimed to correlate routinely used blood biomarkers for perinatal sepsis in cooled asphyxiated newborns with MRI findings. Methods: Perinatal data was retrospectively collected from 67 cooled asphyxiated newborns. Levels of C-reactive protein (CRP), white blood cells and platelets were analyzed before, during and after TH. Interleukin-6 blood levels were analyzed before initiation of TH. Magnetic resonance imaging (MRI) on postnatal day 5-7 was used defining short-term outcome. Adverse outcome was defined as death or adverse MRI findings. Amplitude-integrated electroencephalography (aEEG) was additionally analyzed and correlated with short-term MRI outcome. Results: Forty-nine newborns had favorable short-term MRI outcome. Perinatal data referring to perinatal sepsis did not differ significantly between groups. IL-6 levels before initiation of TH and CRP levels on day three and after TH were significantly higher in newborns with adverse short-term MRI outcome. Males with adverse short-term MRI outcome had significantly increased CRP values at the end of the cooling phase. aEEG strongly correlated with short-term MRI outcome. Conclusion: Routinely used blood biomarkers may be helpful early identifying newborns at high risk of unfavorable outcome and in need of close neurodevelopmental follow-up.

Stratified Management for Bacterial Infections in Late Preterm and Term Neonates: Current Strategies and Future Opportunities Toward Precision Medicine

Bacterial infections remain a major cause of morbidity and mortality in the neonatal period. Therefore, many neonates, including late preterm and term neonates, are exposed to antibiotics in the first weeks of life. Data on the importance of inter-individual differences and disease signatures are accumulating. Differences that may potentially influence treatment requirement and success rate. However, currently, many neonates are treated following a "one size fits all" approach, based on general protocols and standard antibiotic treatment regimens. Precision medicine has emerged in the last years and is perceived as a new, holistic, way of stratifying patients based on large-scale data including patient characteristics and disease specific features. Specific to sepsis, differences in disease susceptibility, disease severity, immune response and pharmacokinetics and -dynamics can be used for the development of treatment algorithms helping clinicians decide when and how to treat a specific patient or a specific subpopulation. In this review, we highlight the current and future developments that could allow transition to a more precise manner of antibiotic treatment in late preterm and term neonates, and propose a research agenda toward precision medicine for neonatal bacterial infections.

Serum Amylase and Lipase for the Prediction of Pancreatic Injury in Critically Ill Children Admitted to the PICU

OBJECTIVES

Pancreatic injury is multifactorial and potentially devastating for critically ill children. We aimed to evaluate whether serum amylase and lipase among critically ill children could serve as an independent biomarker to predict pancreatic injury.

DESIGN

Retrospective cohort.

SETTING

PICU of a tertiary, pediatric medical center.

PATIENTS

Seventy-nine autopsies.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A group of 79 children who died of different causes were investigated by autopsy. They were divided into pancreatic injury group and pancreatic noninjury group according to autopsy findings. Data based on patients' demographics, vital signs, laboratory findings, and clinical features at admission were collected and compared. Logistic regression was used to identify predictive factors for pancreatic injury. Receiver operating characteristic curve was constructed for assessing serum amylase and serum lipase to predicting pancreatic injury. Forty-one patients (51.9%) exhibited the pathologic changes of pancreatic injury. The levels of lactate, erythrocyte sedimentation rate, alanine transaminase, aspartate transaminase, and troponin-I in the injury group were significantly higher than that in the noninjury group, whereas the level of calcium was significantly lower than that in the noninjury group (p < 0.05). Multivariable logistic regression analysis showed that serum amylase, serum lipase, and septic shock were significantly associated with the occurrence rate of pancreatic injury. The statistically significant area under the curve results were as follows: serum amylase: area under the curve = 0.731, at a cutoff value of 97.5, sensitivity = 53.7, and specificity = 81.6; and serum lipase: area under the curve = 0.727, at a cutoff value of 61.1, sensitivity = 36.6, and specificity = 92.1.

CONCLUSIONS

Serum amylase and lipase could serve as independent biomarkers to predict pancreatic injury in critically ill children.

Relevance of Biomarkers Currently in Use or Research for Practical Diagnosis Approach of Neonatal Early-Onset Sepsis

Neonatal early-onset sepsis (EOS) is defined as an invasive infection that occurs in the first 72 h of life. The incidence of EOS varies from 0.5–2% live births in developed countries, up to 9.8% live births in low resource settings, generating a high mortality rate, especially in extremely low birth weight neonates. Clinical signs are nonspecific, leading to a late diagnosis and high mortality. Currently, there are several markers used for sepsis evaluation, such as hematological indices, acute phase reactants, cytokines, which by themselves do not show acceptable sensitivity and specificity for the diagnosis of EOS in neonates. Newer and more selective markers have surfaced recently, such as presepsin and endocan, but they are currently only in the experimental research stages. This comprehensive review article is based on the role of biomarkers currently in use or in the research phase from a basic, translational, and clinical viewpoint that helps us to improve the quality of neonatal early-onset sepsis diagnosis and management.

Biomarkers as point of care tests (POCT) in neonatal sepsis: A state of science review

Lack of a standard definition of neonatal sepsis and a swift diagnostic method has proven detrimental in the management of this serious condition. Biomarkers have emerged as a beacon that might help us detect neonatal sepsis more effectively. The use of point-of-care biomarkers can aid in early diagnosis and timely initiation of treatment. Procalcitonin, presepsin, interleukin-6, highly specific C-reactive protein, and neutrophil gelatinase-associated lipocalin have been proven to aid in early diagnosis and timely initiation of treatment, thereby reducing sepsis-induced morbidity and mortality. These biomarkers have been found to be useful in reducing the duration of hospital stay and monitoring the response to therapy. When used in combination with each other, or with clinical scores, they have been proven to be advantageous over the gold standard by eliminating the waiting time for blood culture results. The use of biomarkers as a point of care investigation holds a future over the traditional method. We present a state of science review of literature summarizing the current status of these biomarkers in neonatal sepsis.

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.

Use of saliva sample to detect C-reactive protein in children with pneumonia

BACKGROUND

Serum C-reactive protein (CRP) is a sensitive biomarker for inflammation and is broadly used to clinically diagnose infectious diseases, including pneumonia. However, blood sampling is fraught with technical difficulties in children. The salivary analysis may be a potential diagnostic tool, as it is noninvasive, patient-friendly, and easy to perform in children. This study aimed to evaluate the use of salivary CRP as a biomarker for children with pneumonia.

METHODS

A prospective study was conducted in patients aged 2 to 17 years, admitted to the hospital with pneumonia. Saliva and serum samples for CRP and chemokine determination were collected at the initial admission and during a follow-up from pediatric patients with pneumonia. Salivary samples were also collected from healthy subjects used as controls.

RESULTS

A total of 60 healthy children and 106 pediatric patients with pneumonia were enrolled in this study. The salivary CRP level was much higher in pediatric patients with pneumonia than in healthy children (48.77 ± 5.52 ng/mL vs 14.78 ± 3.92 ng/mL; P < .001). Salivary CRP level was highly correlated with serum CRP level in pediatric patients with pneumonia (r = .679; P < .001). Salivary CRP level (≥40.307 ng/mL) can be used to predict high serum CRP levels (≥80 mg/L) with an area under the curve of 0.810 (95% confidence interval, 0.740-0.881). As pneumonia improved, both salivary and serum CRP levels decreased during follow-up.

CONCLUSIONS

Salivary CRP could be an alternative biomarker for serum CRP in pediatric patients with pneumonia. This is especially beneficial for pediatric patients, as saliva collection is simple, noninvasive, and patient-friendly.

Impaired Neonatal Immunity and Infection Resistance Following Fetal Growth Restriction in Preterm Pigs

Background: Infants born preterm or small for gestational age (SGA, due to fetal growth restriction) both show an increased risk of neonatal infection. However, it remains unclear how the co-occurrence of preterm birth and SGA may affect neonatal immunity and infection risk. We hypothesized that fetal growth restricted (FGR) preterm newborns possess impaired immune competence and increased susceptibility to systemic infection and sepsis, relative to corresponding normal birth weight (NBW) newborns.

Methods: Using preterm pigs as a model for preterm infants, gene expression in lipopolysaccharide (LPS) stimulated cord blood was compared between NBW and FGR (lowest 25% birth weight percentile) preterm pigs. Next, clinical responses to a systemic Staphylococcus epidermidis (SE) challenge were investigated in newborn FGR and NBW preterm pigs. Finally, occurrence of spontaneous infections were investigated in 9 d-old FGR and NBW preterm pigs, with or without neonatal antibiotics treatment.

Results: At birth, preterm FGR piglets showed diminished ex vivo cord blood responses to LPS for genes related to both innate and adaptive immunity, and also more severe septic responses following SE infection (e.g., higher blood lactate, decreased blood pH, neutrophil and platelet counts, relative to NBW pigs). After 9 d, FGR pigs had higher incidence and severity of spontaneous infections (e.g., higher bacterial densities in the bone marrow), increased regulatory T cell numbers, reduced neutrophil phagocytosis capacity, and impaired ex vivo blood gene responses to LPS, especially when receiving neonatal antibiotics.

Conclusion: FGR at preterm birth is associated with poor immune competence, impaired infection resistance, and greater sepsis susceptibility in the immediate postnatal period. Our results may explain the increased morbidity and mortality of SGA preterm infants and highlight the need for clinical vigilance for this highly sensitive subgroup of preterm neonates.

New Diagnostic Possibilities for Early Onset Neonatal Sepsis: Red Cell Distribution Width to Platelet Ratio

Aims: Red cell distribution width to platelet ratio (RPR) has been reported as a useful inflammatory marker and prognostic indicator of adult inflammatory diseases. In the present study, red cell distribution width (RDW) and RPR parameters, which are parts of a complete blood count analysis, were compared to the traditional C reactive protein (CRP) and procalcitonin (PCT) parameters to investigate the potential to predict early onset sepsis (EOS) in neonates with or without positive blood cultures. Methods: An observational, retrospective cohort study was conducted to evaluate newborns born in our hospital. Results: RDW, RPR, CRP, PCT, Immature to total neutrophil ratio (I/T), and white blood cell (WBC) counts were higher in suspected and proven EOS compared to control group. Conclusion: We believe that RPR may be used in diagnosis of early onset neonatal sepsis and may be a good alternative to other tools as a readily available biomarker.

Clinical Value of Serum Amyloid-A Protein, High-density Lipoprotein Cholesterol and Apolipoprotein-A1 in the Diagnosis and Follow-up of Neonatal Sepsis

BACKGROUND

To evaluate the performance of serum amyloid-A (SAA), high-density lipoprotein cholesterol (HDL-C) and apolipoprotein-A1 (Apo-A1) levels in the identification and monitoring of neonatal sepsis.

METHODS

This prospective study included 113 full-term septic neonates (postnatal age 4-28 days) admitted to the Special Care Neonatal Unit of a University Hospital from January 1, 2016, to April 30, 2019, and 68 healthy neonates (controls). Blood samples were drawn serially in septic neonates at enrollment and on days 1, 3 and 7, and once in controls, for SAA, HDL-C and Apo-A1 determination.

RESULTS

At enrollment, SAA levels were significantly higher in septic neonates in comparison with controls (median 50.7 vs. 3.5 mg/L; P < 0.0001); HDL-C and Apo-A1 levels were significantly lower in patients than in controls (P < 0.001 and P < 0.006, respectively). SAA levels were higher in culture-positive compared with culture-negative sepsis (median 202.0 vs. 14.2 mg/L; P < 0.0001). HDL-C and Apo-A1 levels did not differ significantly between culture-positive and culture-negative sepsis. Receiver operating characteristic curve analysis of SAA levels at enrollment resulted in significant areas under the curve (AUC) for detecting sepsis {AUC = 0.929 [95% confidence interval: 0.885-0.973]; P < 0.0001} and also for discriminating between culture-positive and culture-negative sepsis [AUC = 0.933 (95% confidence interval: 0.882-0.984); P < 0.0001]. The combination of HDL-C and Apo-A1 with SAA increased its diagnostic performance. Furthermore, serial SAA levels following enrollment could indicate clinical response in septic neonates.

CONCLUSIONS

SAA seems to be a useful biomarker for identification and monitoring of neonatal sepsis, and also for discriminating between culture-positive and culture-negative sepsis. HDL-C and Apo-A1 could be used as complementary markers.

Identification of progranulin as a novel diagnostic biomarker for early-onset sepsis in neonates

Neonatal early-onset sepsis (EOS) is associated with high morbidity and mortality. Accurate early diagnosis is crucial for prompt treatment and a better clinical outcome. We aimed to identify new biomarkers for the diagnosis of EOS. A total of 152 neonates with a risk of EOS were divided into an EOS group and a non-EOS group according to the conventional diagnostic criteria. Blood samples were collected within 0-24, 24-48, and 48-72 h after birth. Serum levels of progranulin (PGRN), interleukin (IL)-33, IL-17a, IL-23, IL-6, tumor necrosis factors α (TNF-α), interferon γ (IFN-γ), granulocyte-macrophage colony-stimulating factor (GM-CSF), procalcitonin (PCT), and C-reactive protein (CRP) were determined. PGRN levels were significantly elevated in the EOS neonates compared with the levels in the non-EOS neonates (1.53 vs. 0.77 ng/ml (median), P < 0.001), with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.76 (P < 0.001). Compared with PGRN, IL-33, IL-17a, IL-23, IL-6, PCT, and CRP showed significant (AUC > 0.70) but slightly less predictive power for EOS within the same time range. Stepwise multivariate regression analysis identified PGRN, IL-33, and PCT as independent predictors of EOS. In addition, the combined measurements of PGRN, IL-33, and PCT showed significantly higher predictive power for EOS than any of the three markers alone. PGRN showed greater efficacy for predicting EOS than the traditional markers PCT and CRP as well as other potential markers tested in this study. PGRN may serve as an effective biomarker for the early diagnosis of EOS.

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.

Diagnostic utility of procalcitonin as a biomarker for late-onset neonatal sepsis

BACKGROUND

To explore the diagnostic utility of procalcitonin (PCT) as a biomarker for late-onset neonatal sepsis (LONS).

METHODS

The clinical and laboratory data of 131 neonatal patients in the neonatal intensive cares unit (NICU) of our center (Department of Neonatology, Renmin Hospital of Wuhan University) from June 1, 2015, to May 31, 2018, were retrospectively analyzed. These patients were divided into 3 groups based on their disease conditions: the bacterial sepsis (BS) group (n=47), the fungal sepsis (FS) group (n=39), and the normal control group (n=45, without sepsis). Blood cultures, routine blood tests, and testing for PCT and C-reactive protein (CRP) were performed in all 3 groups. Both PCT and CRP were measured by using enzyme-linked immunosorbent assay (ELISA). Blood culture was performed in an automated blood culture system. Routine blood tests were performed by using a fully automatic hematology analyzer.

RESULTS

Serum PCT level was significantly different between the BS group and control group (P<0.01) but showed no significant difference between the FS group and control group (P>0.05); the difference in CRP was statistically significant between the FS group and control group (P<0.01) but was not statistically significant between the BS group and control group (P>0.05). The areas under the receiver operating characteristics (ROC) curve were 0.979 and 0.826 for PCT/CRP in the BS group and FS group, with a best cutoff value of 0.93 and 33.27, respectively; the sensitivities and specificities of PCT/CRP in these 2 groups were 0.962/0.679 and 0.964/0.964, respectively.

CONCLUSIONS

Compared with CRP, PCT is more sensitive in diagnosing BS but is not sensitive for diagnosing FS. Therefore, PCR is a useful biomarker in distinguishing BS from FS in neonates with late-onset sepsis.

Performance of Pediatric Systemic Inflammatory Response Syndrome and Organ Dysfunction Criteria in Late-Onset Sepsis in a Quaternary Neonatal Intensive Care Unit: A Case-Control Study

OBJECTIVES

To evaluate accuracy of systemic inflammatory response syndrome (SIRS) criteria in identifying culture-proven late-onset neonatal sepsis and to assess prevalence of organ dysfunction and its relationship with SIRS criteria.

STUDY DESIGN

This was a retrospective case-control study of patients in the Children's Hospital of Philadelphia level IV neonatal intensive care unit undergoing sepsis evaluations (concurrent blood culture and antibiotics). During calendar years 2016-2017, 77 case and 77 control sepsis evaluations were identified. Cases included infants who had sepsis evaluations with positive blood cultures and antibiotic duration ≥7 days. Controls were matched by gestational and postmenstrual age, and had sepsis evaluations with negative blood cultures and antibiotic duration ≤48 hours. SIRS criteria were determined at time of sepsis evaluation, and organ dysfunction evaluated in the 72 hours following sepsis evaluation. Statistical analysis included descriptive statistics, Mann-Whitney tests, and χ² (Fisher exact) tests.

RESULTS

At time of sepsis evaluation, 42% of cases and 26% of controls met SIRS criteria. Among infants of ≤37 weeks postmenstrual age, SIRS criteria were met in only 17% of sepsis evaluations (4 of 23 in both cases and controls). Test characteristics for SIRS at diagnosis of culture-proven sepsis included sensitivity 42% and specificity 74%. Cases had higher rates of new organ dysfunction within 72 hours (40% vs 21%); however, 58% of cases developing organ dysfunction did not meet SIRS criteria at time of sepsis evaluation. Of 6 deaths (all cases with organ dysfunction), 2 did not meet SIRS criteria at sepsis evaluation.

CONCLUSIONS

SIRS criteria did not accurately identify culture-proven late-onset sepsis, with poorest accuracy in preterm infants. SIRS criteria did not predict later organ dysfunction or mortality.

Commentary on "C-Reactive Protein for the Diagnosis of Late-Onset Infections in Newborn Infants"

BACKGROUND:

Late-onset infection is the most common serious complication associated with hospital care for newborn infants. Because confirming the diagnosis by microbiological culture typically takes 24 to 48 hours, the serum level of the inflammatory marker C-reactive protein (CRP) measured as part of the initial investigation is used as an adjunctive rapid test to guide management in infants with suspected late-onset infection.

OBJECTIVES:

To determine the diagnostic accuracy of serum CRP measurement in detecting late-onset infection in newborn infants.

SEARCH METHODS:

We searched electronic databases (MEDLINE, Embase, and Science Citation Index to September 2017), conference proceedings, previous reviews, and the reference lists of retrieved articles.

SELECTION CRITERIA:

We included cohort and cross-sectional studies evaluating the diagnostic accuracy of serum CRP levels for the detection of late-onset infection (occurring more than 72 hours after birth) in newborn infants.

DATA COLLECTION AND ANALYSIS:

Two review authors independently assessed eligibility for inclusion, evaluated the methodological quality of included studies, and extracted data to estimate diagnostic accuracy using hierarchical summary receiver operating characteristic (SROC) models. We assessed heterogeneity by examining variability of study estimates and overlap of the 95% confidence interval (CI) in forest plots of sensitivity and specificity.

MAIN RESULTS:

The search identified 20 studies (1615 infants). Most were small, single-centre, prospective cohort studies conducted in neonatal units in high- or middle-income countries since the late 1990s. Risk of bias in the included studies was generally low with independent assessment of index and reference tests. Most studies used a prespecified serum CRP threshold level as the definition of a ‘positive’ index test (typical cut-off level between 5 mg/L and 10 mg/L) and the culture of a pathogenic micro-organism from blood as the reference standard. At median specificity (0.74), sensitivity was 0.62 (95% CI 0.50 to 0.73). Heterogeneity was evident in the forest plots, but it was not possible to conduct subgroup or meta-regression analyses by gestational ages, types of infection, or types of infecting micro-organism. Covariates for whether studies used a predefined threshold or not, and whether studies used a standard threshold of between 5 mg/L and 10 mg/L, were not statistically significant.

AUTHORS’ CONCLUSIONS:

The serum CRP level at initial evaluation of an infant with suspected late-onset infection is unlikely to be considered sufficiently accurate to aid early diagnosis or select infants to undergo further investigation or treatment with antimicrobial therapy or other interventions.

The Pathogenesis of Sepsis and Potential Therapeutic Targets

Sepsis is defined as “a life-threatening organ dysfunction caused by a host’s dysfunctional response to infection”. Although the treatment of sepsis has developed rapidly in the past few years, sepsis incidence and mortality in clinical treatment is still climbing. Moreover, because of the diverse manifestations of sepsis, clinicians continue to face severe challenges in the diagnosis, treatment, and management of patients with sepsis. Here, we review the recent development in our understanding regarding the cellular pathogenesis and the target of clinical diagnosis of sepsis, with the goal of enhancing the current understanding of sepsis. The present state of research on targeted therapeutic drugs is also elaborated upon to provide information for the treatment of sepsis.

Clinical and Microbiological Characteristics of Group B Streptococcus from Pregnant Women and Diseased Infants in Intrapartum Antibiotic Prophylaxis Era in Taiwan

Group B Streptococcus (GBS) is one of the most important pathogens for neonates. This study included 69 invasive GBS diseases in neonates, including 7 early-onset disease (EOD), 55 late-onset disease, and 7 very-late-onset disease from 2013 to 2017. A significant reduction of EOD after the deployment of intrapartum antibiotic prophylaxis (IAP) in 2012 was observed. A previously-recognized hypervirulent clone GBS III ST17, accounting for 68% of the overall infections and 71% of the meningitis, was identified among the 69 cases. A novel GBS Ia ST890 emerged, becoming the fourth most common clone. Overall 96% of the invasive GBS infections were caused by serotypes Ia, Ib, and III. We collected 300 GBS isolates from vagina of the healthy pregnant women in 2014 and 2017. The serotype distribution of the maternal colonization isolates was VI (35%), III (21%), V (15%), Ib (13%) and Ia (11%) in 2014, and VI (32%), III (22%), V (16%), Ia (16%), and Ib (8%) in 2017. The most common sequence types were ST1 (32%), ST12 (22%), and ST23 (15%). Serotype diversity of maternal colonization strains did not change between 2014 and 2017. The study provides useful information in surveillance of GBS disease in the era of IAP.

Platelet to Lymphocyte Ratio in Neonates: A Predictor of Early onset Neonatal Sepsis

Background

Neonatal sepsis (NS) is a common systemic disease that causes morbidity and mortality in newborns. But there is no ideal biomarker that can be used in the early diagnosis of NS. In recent studies, platelet to lymphocyte ratio (PLR) has been reported to play a critical role in the inflammatory process. In this study, we aimed to contribute to the research about whether or not PLR can be used as an early predictor of the diagnosis of NS.

Methods

This retrospective cohort study was conducted among the newborns born in İzmir Buca Maternity and Pediatric Hospital between March 2015–February 2016. During these twelve months, 611 neonates with Early-Onset Sepsis (EOS) were admitted to our neonatal intensive care unit. One hundred and forty-nine neonates with suspected EOS, 67 neonates with proven EOS and 92 healthy neonates were enrolled in the study.

Results

Platelet to lymphocyte ratio (PLR) values of the three groups were calculated 56.5 ± 17.8 vs. 62.4± 14.9 vs. 15.3 ± 2.1, respectively. PLR values of suspected or proven EOS group were significantly higher than the control group. PLR has AUC 0.89 to 0.93, the cutoff value of 39.5 to 57.7, the sensitivity of 88.9% to 91.3% and specificity of 94.7% to 97.6%, the positive predictive value of 94.3% to 97.4%, and negative predictive value of 88.6% to 91.8% in suspected and proven sepsis diagnosis.

Conclusions

Our results suggest that PLR can be used as a parameter in the prediction of neonatal sepsis.

Predictors of early-onset neonatal sepsis or death among newborns born at <32 weeks of gestation

OBJECTIVE

To develop a predictive model for early-onset neonatal sepsis or death among infants born at less than 32 weeks of gestation.

STUDY DESIGN

This was a case-control study of all deliveries <32 weeks between 2011 and 2015 in a single tertiary care center. Cases were defined as neonates diagnosed with early-onset sepsis based on a blood or cerebrospinal fluid culture or neonates who expired during the first week of life. Controls consisted of neonates without these outcomes. Variables previously identified to be associated with neonatal sepsis or death were abstracted from the medical record. Bivariable analyses and multivariable logistic regression were used to determine independent risk factors for early-onset neonatal sepsis or death. An ROC curve was created and AUC calculated to estimate the predictive capacity of these associations.

RESULTS

Of 779 eligible neonates, early-onset neonatal sepsis or death occurred in 73 (9.4%). In bivariable analyses, mothers whose neonates were diagnosed with early-onset sepsis or death were more likely to be obese, have an intrapartum fever, and have meconium-stained amniotic fluid, and were less likely to have received betamethasone or antepartum/intrapartum antibiotics. Gestational age at delivery and birth weight was significantly lower among neonates diagnosed with neonatal sepsis or death. In multivariable analyses, factors remaining independently associated with neonatal sepsis or death were earlier gestational age at the time of delivery (specifically <28 weeks), intrapartum fever, presence of meconium-stained amniotic fluid, and lower birth weight. The AUC for this regression was 0.81 (95% confidence interval 0.77-0.83).

CONCLUSION

Earlier gestational age at the time of delivery, intrapartum fever, meconium, and lower birth weight are independently associated with early-onset neonatal sepsis or death among deliveries occurring at <32 weeks of gestation; these factors can be used to create a model with fair predictive capability.

Practice variations and rates of late onset sepsis and necrotizing enterocolitis in very preterm born infants, a review

The burden of late onset sepsis (LOS) and necrotizing enterocolitis (NEC) remains high for newborns in low- and high-income countries. Very preterm born infants born below 32 weeks gestation are at highest risk because their immune system is not yet adapted to ex-utero life, providing intensive care frequently compromises their skin or mucosa and they require a long duration of hospital stay. An epidemiological overview is difficult to provide because there is no mutually accepted definition available for either LOS or NEC. LOS incidence proportions are generally reported based on identified blood culture pathogens. However, discordance in minimum day of onset and whether coagulase negative staphylococci or fungi should be included into the reported proportions lead to variation in reported incidences. Complicating the comparison are the absence of biomarkers, ancillary lab tests or prediction models with sufficiently high positive and/or negative predictive values. The only high negative predictive values result from negative blood culture results with negative lab results allowing to discontinue antibiotic treatment. Similar difficulties exist in reporting and diagnosing NEC. Although most publications base their proportions on a modified version of Bell's stage 2 or 3, comparisons are made difficult by the multifactorial nature of the disease reflecting several pathways to intestinal necrosis, the absence of a reliable biomarker and the unclear differentiation from spontaneous intestinal perforations. Comparable reports in very low birthweight infants range between 5% and 30% for LOS and 1.6% to 7.1% for NEC. Evidence based guidelines to support treatment are missing. Treatment for LOS remains largely empirical and focused mainly on antibiotics. In the absence of a clear diagnosis, even unspecific early warning signals need to be met with antibiotic treatment. Cessation after negative blood culture is difficult unless the child was asymptomatic from the beginning. As a result, antibiotics are the most commonly prescribed medications, but unnecessary exposure may result in increased risk for mortality, NEC, further infections and childhood obesity or asthma. Finding ways to limit antibiotic use are thus important and have shown a large potential for improvement of care and limitation of cost. Over recent decades, none of the attempts to establish novel therapies have succeeded. LOS and NEC proportions remained mostly stable. During the past 10 years however, publications emerged reporting a reduction, sometimes by almost 50%. Most concern units participating in a surveillance system using quality improvement strategies to prevent LOS or NEC (e.g., hand hygiene, evidence based "bundles", feeding onset, providing own mother's milk). We conclude that these approaches display a potential for wider spread reduction of LOS and NEC and for a subsequently more successful development of novel therapies as these often address the same pathways as the prevention strategies.

Prolonged Rupture of Membranes, Neonatal Outcomes and Management Guidelines

BACKGROUND

Prolonged rupture of membranes (PROM) is a risk factor for early-onset neonatal sepsis (EOS). In the absence of early specific and sensitive diagnostic tools, management of asymptomatic infants is difficult. This study was conducted to investigate clinical outcomes of newborns born to mothers with PROM.

METHODS

A retrospective study of neonates ≥ 34 weeks admitted due to PROM was conducted. Medical charts were reviewed. Neonates were classified into three categories based on their status at birth: ill appearing, well, and equivocal. Sepsis risk calculator was retrospectively applied.

RESULTS

A total of 176 neonates were included. All mothers had unknown group B streptococcus (GBS) status. Of them, 74.4% were asymptomatic. Nine infants (5%) had positive cultures, and 23 infants (13%) had culture-negative sepsis. The newborns with sepsis fit into the "ill appearing" category with a significantly higher proportion (12.5% vs. 0.0%, P value < 0.0).

CONCLUSIONS

Reliable early diagnostic tools for neonatal sepsis are lacking. Adopting a protocol that utilizes multiple methods and follow-up for the clinical condition of these infants are the key factors to avoid missing neonates with true sepsis and decreasing the use of antibiotics in those without infection.