Procalcitonin as an early marker of infection in neonates and children

Early procalcitonin assays may reduce antibiotic exposure in premature newborn infants

AIM

The diagnosis of early-onset neonatal sepsis (EOS) remains difficult. The main aim was to study the effect of a new algorithm for EOS, which includes the level of procalcitonin in umbilical cord blood, on the exposure to antibiotic therapy of premature newborn infants.

METHODS

This was a monocentric, observational and retrospective study with before-and-after design. The duration and dose of antibiotic therapy provided as well as the morbidity and mortality were compared in two groups, one included 01 May 2015-30 November 2015 when procalcitonin was not used, and one after the change 01 November 2016-30 May 2017 when procalcitonin was used in a hospital setting in Nice, France.

RESULTS

Sixty newborn infants were included in the before group and 54 in the after group. Antibiotic therapy was stopped after 24 h for 18 newborn infants in the after group and four in the before group, and after 48 h for 26 newborn infants in the after group and 10 in the before group.

CONCLUSION

The implementation of a new decision-making algorithm including early procalcitonin assay of premature newborn infants significantly reduced exposure to antibiotics without modifying mortality or morbidity.

Changes in serum inflammatory factors in group B streptococcal infection and their predictive value for premature rupture of membranes complicated by chorioamnionitis

Objective: The aim of this study as to unveil changes in serum inflammatory factors in pregnant women with genital tract group B Streptococcus (GBS) infection and their predictive value for premature rupture of membranes (PROM) complicated by chorioamnionitis (CS) and adverse pregnancy outcomes. Methods: The value of serum inflammatory factor levels in predicting PROM complicating CS and adverse pregnancy outcomes in GBS-infected pregnant women was evaluated by ELISA. Results: Serum IL-6, TNF-α, PCT and hs-CRP levels were higher in pregnant women with GBS infection. The combined diagnosis of these factors had excellent diagnostic value in PROM complicating CS and adverse pregnancy outcomes. Conclusion: Joint prediction of IL-6, TNF-α, PCT and hs-CRP has the best predictive value for PROM complicating CS and adverse pregnancy outcomes.

Kocuria species: an underappreciated pathogen in pediatric patients-a single-center retrospective analysis of 10 years' experience in China

Kocuria species are known to be opportunistic pathogens that cause infections in humans, especially immunocompromised hosts. However, reports of pediatric patients are limited. This retrospective study was designed to investigate the spectrum of infections in pediatric patients caused by Kocuria species. Thirty-six patients were enrolled; of these, 29 were infected by Kocuria kristinae, 4 by Kocuria roseus, 2 by Kocuria varians, and 1 by Kocruria rhizophila. Twenty-six patients were diagnosed with bloodstream infection; 6 had ventilator-associated pneumonia; and one each had a catheter-associated urinary tract infection, purulent meningitis, cholangitis, and empyema. Twenty-seven patients were immunocompromised or debilitating, had congenital abnormalities or fitted with indwelling devices. Nine patients were immunocompetent, 4 with early onset before 1 year of age. All Kocuria species were susceptible to lenezolid, vancomycin, and tigecycline; while showing frequent resistance to penicillin and oxacillin. Most cases were cured by administering appropriate antimicrobial agents. To our knowledge, this is the largest case series of pediatric patients with Kocuria species infection. We highlight Kocuria species should be considered as an underappreciated pathogen in pediatric patients.

Outcomes of Infants Who Are Febrile Aged 29-90 Days Discharged from the Emergency Department

OBJECTIVE

To evaluate the characteristics and outcomes of infants aged 29-90 days who are febrile discharged from the pediatric emergency department (ED).

STUDY DESIGN

This was a multicenter, retrospective cohort study of infants aged 29-90 days who visited any of the 7 Clalit Health Services pediatric EDs in Israel between January 1, 2019, and March 31, 2022. Infants who were febrile discharged from the ED after having blood and urine cultures taken were included. The primary outcome measure was the incidence of return visit (RV) to an ED. Secondary outcome measures were the incidence of invasive bacterial infection, urinary tract infection, pediatric intensive care unit admissions, and deaths. We assessed variables associated with the primary outcomes.

RESULTS

A total of 1647 infants were included. Their median (IQR) age at ED visit was 58.5 (47.7, 72.7) days, 53.1% were male. A total of 329 patients (20%) returned to the ED within 120 hours. Overall, 7.8% of discharged infants had a positive urine culture, 4 (0.2%) had a positive blood culture, and none had meningitis. One patient was admitted to the pediatric intensive care unit, and there was no death. Abnormal C-reactive protein was associated with RV among 61- to 90-day-old infants.

CONCLUSIONS

Infants aged 29-90 days who were febrile and discharged following a protocol-driven pathway from the pediatric ED had a relatively high RV rate. However, the rate of urinary tract infection was relatively low, and rate of invasive bacterial infection was extremely low. There were no deaths or serious sequelae.

Comparison of presepsin and Mid-regional pro-adrenomedullin in the diagnosis of sepsis or septic shock: a systematic review and meta-analysis

BACKGROUND

The early diagnosis of sepsis is hampered by the lack of reliable laboratory measures. There is growing evidence that presepsin and Mid-regional pro-adrenomedullin (MR-proADM) are promising biomarkers in the diagnosis of sepsis. This study was conducted to evaluate and compare the diagnostic value of MR-proADM and presepsin in sepsis patients.

METHODS

We searched Web of Science, PubMed, Embase, China national knowledge infrastructure, and Wanfang up to 22th July, 2022, for studies evaluating the diagnosis performance of presepsin and MR-proADM in adult sepsis patients. Risk of bias was assessed using quadas-2. Pooled sensitivity and specificity were calculated using bivariate meta-analysis. Meta-regression and subgroup analysis were used to find source of heterogeneity.

RESULTS

A total of 40 studies were eventually selected for inclusion in this meta-analysis, including 33 for presepsin and seven for MR-proADM. Presepsin had a sensitivity of 0.86 (0.82-0.90), a specificity of 0.79 (0.71-0.85), and an AUC of 0.90 (0.87-0.92). The sensitivity of MR-proADM was 0.84 (0.78-0.88), specificity was 0.86 (0.79-0.91), and AUC was 0.91 (0.88-0.93). The profile of control group, population, and standard reference may be potential sources of heterogeneity.

CONCLUSIONS

This meta-analysis demonstrated that presepsin and MR-proADM exhibited high accuracy (AUC ≥ 0.90) in the diagnosis of sepsis in adults, with MR-proADM showing significantly higher accuracy than presepsin.

Detection of serum human neutrophil lipocalin is an effective biomarker for the diagnosis and monitoring of children with bacterial infection

BACKGROUND

The study aimed to investigate the diagnostic efficiency of human neutrophil lipocalin (HNL) in bacterial infections in children.

METHODS

This study included 49 pediatric patients with bacterial infections, 37 patients with viral infections, 30 patients with autoimmune diseases (AID) and 41 healthy controls (HCs). HNL, procalcitonin (PCT), C-reactive protein (CRP), white blood cell (WBC) and neutrophil counts were detected in the initial diagnosis and the following days.

RESULTS

In the patients with bacterial infections, the levels of HNL, PCT, CRP, WBC and neutrophils were significantly increased than that of disease controls and HCs. The dynamic of these markers was monitored during antibiotic treatment. The level of HNL was decreased rapidly in patients with effective treatment, but maintained at high levels in deteriorated patients according to the clinical progression.

CONCLUSIONS

HNL detection is an effective biomarker to identify bacterial infections from viral infections and other AIDs, and has potential value to evaluate the effect of antibiotic treatment in pediatric patients.

Viremia as a predictor of absence of serious bacterial infection in children with fever without source

Most children with fever without source (FWS) require diagnostic laboratory tests to exclude a serious bacterial infection (SBI), often followed by admission and empirical antibiotics. As febrile children with a viral infection are less likely to have a SBI, identifying patients with systemic viral infection could contribute to exclude SBI. We evaluated whether the presence of virus in the blood could be used as a biomarker to rule out SBI. Children < 3 years old with FWS were prospectively enrolled and had real-time (reverse-transcription) PCR performed on the blood for adenovirus, enterovirus, parechovirus, and HHV6. 20/135 patients had SBI, and in 47/135, at least one virus was detected in the blood. Viremia had a higher sensitivity and negative predictive value (90% and 96%) to rule out SBI compared to CRP (65% and 93%) and PCT (55% and 90%). The odds ratio (OR) for the presence of SBI among non-viremic patients was 5.8 (p = 0.0225), compared to 5.5 for CRP ≥ 40 mg/l (p = 0.0009) and 3.7 for PCT ≥ 0.5 ng/mL (0.0093). This remained significant after adjusting for CRP and PCT (OR 5.6 and 5.9, respectively; p = 0.03 for both). Area under the ROC curve for CRP and PCT were 0.754 and 0.779, respectively, but increased to 0.803 and 0.832, respectively, when combined with viremia.

CONCLUSION

The presence of viremia had a better performance than commonly used biomarkers to rule-out SBI and could potentially be used in conjunction with CRP and/or PCT in the evaluation of children with FWS. Larger studies should evaluate the role of point-of-care testing of viruses by (revere-transcription) PCR in the plasma in management algorithms of children with FWS.

WHAT IS KNOWN

• Most children with FWS have a viral infection, but up to 15% have a SBI; most require laboratory tests, and many admission and empirical antibiotics. • Children with a viral infection are less likely to have a SBI.

WHAT IS NEW

• Children with a systemic viral infection are less likely to have an SBI. • Viremia is a better predictor of absence of SBI than commonly used biomarkers and could potentially be used in conjunction with CRP and/or PCT in the evaluation of children with FWS.

The Role of Procalcitonin for Predicting Kawasaki Disease

Some studies have estimated the diagnostic value of procalcitonin (PCT) for Kawasaki disease (KD), but the results are not always consistent. The aim of this study was to ascertain the diagnostic value of PCT for KD. Relevant and eligible articles assessing the diagnostic significance of PCT in KD were systematically searched from PubMed as well as the CNKI databases (last update: October 31, 2020), followed by bivariate models to evaluate the overall diagnostic significance of PCT in KD. This systematic review and meta-analysis included four articles. The overall diagnostic specificity and sensitivity were 0.78 (95% CI: 0.74-0.82) and 0.73 (95% CI: 0.69-0.76), respectively. The area under the summary receiver operating characteristic (sROC) curve (AUC) was 0.82. The negative likelihood ratio (NLR) and positive likelihood ratio (PLR) values for PCT were 0.34 and 3.23, respectively. By analyzing the accessible articles, we showed PCT is not a particularly useful test for KD diagnosis.

The diagnostic value of interleukin 35 as a septic biomarker: A meta-analysis

Background

There is growing evidence that interleukin 35 (IL-35) represents a potential diagnostic biomarker for sepsis. The purpose of this meta-analysis was to evaluate the overall diagnostic accuracy of IL-35 in sepsis.

Materials and methods

From October 1998 to May 2022, set retrieval standards were used to search literature Databases. Each included study was assessed diagnostic accuracy study quality assessment tool. Two researchers independently extracted the data and research features. If there are differences, the issue will be resolved by mutual agreement. Meta-disc and Stata software were utilized to calculate combined sensitivity, specificity, and summary diagnostic odds ratio (SDOR), I2, or Cochrane Q in order to detection for heterogeneity, and meta-regression was performed to figure out the cause of heterogeneity. Utilizing funnel plots, we tested for publication bias.

Results

In this meta-analysis, eight publications were included. The combined sensitivity, specificity, and DOR were 0.87 (95% CI, 0.77–0.93), 0.73 (95% CI, 0.60–0.83), and 18.26 (95% CI, 9.70–34.37), respectively. In addition, 0.88 (95% CI, 0.84–0.90) was the area under the summary receiver operating characteristic curve. In the heterogeneity analysis, the sensitivity of comprehensive I2 statistic was 84.38, and the specificity was 87.82. Deeks’ funnel plot showed no publication bias in this meta-analysis (P = 0.17). A meta-analysis revealed that IL-35 has a modest sensitivity (AUC = 0.88) for diagnosing sepsis. We also compared the diagnostic accuracy of IL-35 and procalcitonin (PCT), and our results showed that the diagnostic accuracy parameters for IL-35 were significantly higher than those for PCT.

Conclusion

Interleukin 35 is a valuable biomarker for the early detection of sepsis. However, the data should be combined with clinical symptoms, signs, and laboratory and microbiological findings.

Prokineticin 2 promotes macrophages-mediated antibacterial host defense against bacterial pneumonia

OBJECTIVES

Bacterial pneumonia is a common serious infectious disease with high morbidity and mortality. Prokineticin 2 (PK2) has recently been identified as a novel immunomodulator in a variety of diseases; however, its role in bacterial pneumonia remains unclear.

METHODS

The levels of PK2 were measured and analyzed in patients with pneumonia and healthy controls. The effects of PK2 on the host response to pneumonia were evaluated by in vivo animal experiments and in vitro cell experiments.

RESULTS

PK2 levels dramatically decreased in patients with pneumonia compared with healthy controls, and PK2 levels were lower in patients with severe pneumonia than in pneumonia. In a mouse model of bacterial pneumonia, transtracheal administration of recombinant PK2 significantly alleviated lung injury and improved the survival, which was associated with increased host's bacterial clearance capacity, as manifested by decreased pulmonary bacterial loads. PK2 enhanced the chemotaxis, phagocytosis, and killing ability of macrophages, whereas the protective efficacy of PK2 was abolished after macrophage depletion.

CONCLUSION

Impaired alveolar macrophage function caused by decreased PK2 is a new endogenous cause of the occurrence and development of bacterial pneumonia. The administration of recombinant PK2 may be a potential adjuvant therapy for bacterial pneumonia.

Zinc Supplementation in Preterm Neonates with Late-Onset Sepsis: Is It Beneficial?

OBJECTIVE

Neonatal sepsis (NS) is a serious neonatal disease. The aim of this study was to detect the role of zinc (Zn) supplementation in preterm neonates with late-onset sepsis (LOS).

STUDY DESIGN

A prospective randomized clinical trial study which was done at Tanta University Hospital from August 2016 to March 2018 on 180 preterm neonates with LOS. The studied neonates were divided into two groups: group 1 (90 neonates), which received Zn and antibiotics, and group 2 (90 neonates), which received antibiotics and placebo. In group 1, the neonates received 1.4 mg elemental Zn/kg/d orally for 10 days. Sepsis score, C-reactive protein (CRP), and procalcitonin (PCT) were done for both groups.

RESULTS

As regards sepsis score, it showed that before beginning the treatment, there were 85 and 84 neonates who had high probable sepsis (HPS) in intervention and control groups, respectively, and this revealed nonstatistically significant difference (non-SSD) between both groups (p-value is 0.756) and after 10 days of treatment, there were 1 and 4 neonates who had HPS in intervention and control group, respectively, and this revealed SSD between both groups (p-value is 0.045*). As regards CRP and PCT, the results showed that before beginning the treatment, the mean ± standard deviation (SD) of CRP and PCT were 39.4 ± 10.1 mg/L and 5.2 + 1.8 ng/mL, respectively, in intervention group, while it was 39.6 + 9.9 mg/L and 5.1 + 1.9 ng/mL, respectively, in control group and this revealed non-SSD between both groups (p-value is 0.893 and 0.717, respectively) and after 10 days of treatment, the mean ± SD of CRP and PCT were 5.3 ± 1.8 mg/L and 0.39 ± 0.13 ng/mL, respectively, in intervention group and 6.1 + 2 mg/L and 0.61 + 0.22 ng/mL, respectively, in control group and this revealed SSD between both groups (p-value is 0.008* and 0.044*, respectively).

CONCLUSION

Zn supplementation in preterm neonates with LOS is beneficial in improving the clinical and laboratory finding.

RECOMMENDATION

Zn supplementation for preterm neonates with LOS.

KEY POINTS

· NS is a serious neonatal disease.. · Preterm neonates are more liable to infections.. · Zn supplementation in preterm neonates with LOS is beneficial in improving the condition..

Establishment of a predictive model for purulent meningitis in preterm infants

BACKGROUND

Purulent meningitis (PM) is an important cause of mortality and morbidity in the newborn population throughout the world. The subtle of specific clinical signs and low success rates of lumbar puncture make diagnosis of PM more difficult in preterm than in older children. The objective of this study was to establish a predict model for preterm PM in hopes of helping clinicians develop new diagnostic and treatment strategies.

METHODS

Premature infants who were admitted to The First Affiliated Hospital of Zhengzhou University from September 2017 to March 2020 were enrolled in this study. All the patients underwent lumbar puncture. We collected data encompassing maternal diseases and neonatal clinical features. Cerebrospinal fluid (CSF) culture is the gold standard for diagnosing meningitis. The PM was diagnosed according to the diagnostic criteria. All statistical analyses were performed using R 3.63 (https://www.r-project.org/). Logistic regression and least absolute shrinkage and selection operator (LASSO) regression analyses were used to establish a risk prediction model of PM. The Brier score, calibration slope, and concordance (C)-index were used to verify the accuracy of prediction model.

RESULTS

A total of 168 preterm infants were enrolled in this study, 80 boys and 88 girls, the gestational age (GA) was 26.43-36.86 weeks (32.45±2.79 weeks), the birth weight (BW) was 700-3,400 g (1,814.05±568.84 g). There were 77 preterm infants with PM while 91 without. We identified seven variables as independent risk factors for PM in preterm infants by LASSO analysis [the optimal λ was 0.080960, and log(λ) = -2.5138], including procalcitonin (PCT) on the 1st day after birth, prenatal glucocorticoid use, albumin, the 1-minute Apgar score, the use of non-invasive biphasic positive airway pressure, hemoglobin, and sex. These were used to construct a risk prediction nomogram and verified its accuracy. The Brier score was 0.17, the calibration slope was 0.966, and the concordance index was 0.82018.

CONCLUSIONS

Our prediction model could predict the risk of PM in preterm infants. Using this prediction model, it may be able to provide reference to determine whether lumbar puncture is performed and whether antibiotics are applied as soon as possible.

Diagnostic accuracy of procalcitonin in maternal plasma to detect early intra-amniotic infection in preterm premature rupture of the membranes with respect of highvaginal swab as gold standard

Objective:

To determine the diagnostic accuracy of procalcitonin in maternal plasma to detect early intra-amniotic infection in Preterm premature rupture of the membranes (PPROM) with respect of high vaginal swab as gold standard

Methods:

A cross-sectional study was conducted at Liaquat National Hospital, Karachi, from February to August 2017. The blood sample of women with PPROM were collected to measure procalcitonin level. PCT1 and PCT2 were run along with the sample for the accuracy of the results. Sensitivity, specificity, PPV, NPV, and diagnostic accuracy of procalcitonin were calculated taking HVS C/S as gold standard.

Results:

Out of total 150 women, mean age was 28.78±4.79 years. Mean gestational age was 30.79±3.07 weeks. Mean procalcitonin level was 0.13±0.24 ng/ml. Intra-amniotic infection was diagnosed in 48.7% cases through procalcitonin levels and 51.3% through HVS culture and sensitivity. Sensitivity, Specificity, PPV (Positive predictive value), NPV (Negative predictive value) and accuracy were 87%, 91.8%, 91.78%, 87%, and 89.3% respectively. For females with gestational age ≤32 weeks, sensitivity, specificity, and diagnostic accuracy were 83.9%, 90.4%, and 87.03% respectively. For females with gestational age >32 weeks, sensitivity, specificity, and diagnostic accuracy were 95.2%, 92.5%, and 95.23% respectively.

Conclusion:

Diagnostic accuracy of maternal blood procalcitonin levels were found satisfactory in detection of early intra-amniotic infection in PPROM.

Biomarkers of gut injury in neonates - where are we in predicting necrotising enterocolitis?

Despite advances in neonatal care Necrotising Enterocolitis (NEC) continues to have a significant mortality and morbidity rate, and with increasing survival of those more immature infants the population at risk of NEC is increasing. Ischaemia, reperfusion, and inflammation underpin diseases affecting intestinal blood flow causing gut injury including Necrotising Enterocolitis. There is increasing interest in tissue biomarkers of gut injury in neonates, particularly those representing changes in intestinal wall barrier and permeability, to determine whether these could be useful biomarkers of gut injury. This article reviews current and newly proposed markers of gut injury, the available literature evidence, recent advances and considers how effective they are in clinical practice. We discuss each biomarker in terms of its effectiveness in predicting NEC onset and diagnosis or predicting NEC severity and then those that will aid in surveillance and identifying those infants are greatest risk of developing NEC.

Procalcitonin at 12-36 hours of fever for prediction of invasive bacterial infections in hospitalized febrile neonates

AIM

We aimed to investigate the performance of procalcitonin (PCT) assay between 12 and 36 h after onset of fever (PCT H12-H36) to predict invasive bacterial infection (IBI) (ie, meningitis and/or bacteremia) in febrile neonates.

METHODS

We retrospectively included all febrile neonates hospitalized in the general pediatric department in a teaching hospital from January 2013 to December 2019. PCT assay ≤ 0.6 ng/ml was defined as negative. The primary outcome was to study the performance of PCT H12-H36 to predict IBI.

RESULTS

Out of 385 included neonates, IBI was ascertainable for 357 neonates (92.7%). We found 16 IBI: 3 meningitis and 13 bacteremia. Sensitivity and specificity of PCT H12-H36 in the identification of IBI were, respectively, 100% [95% CI 82.9-100%] and 71.8% [95% CI 66.8-76.6%], with positive and negative predictive values of 14.3% [95% CI 8.4-22.2%] and 100% [95% CI 98.8-100%] respectively. Of the 259 neonates who had a PCT assay within the first 12 h of fever (< H12) and a PCT assay after H12-H36, 8 had IBI. Two of these 8 neonates had a negative < H12 PCT but a positive H12-H36 PCT.

CONCLUSIONS

PCT H12-H36 did not miss any IBI whereas < H12 PCT could missed IBI diagnoses. PCT H12-H36 might be included in clinical decision rule to help physicians to stop early antibiotics in febrile neonates.

Haploinsufficiency of A20 in a Chinese child caused by loss-of-function mutations in TNFAIP3: A case report and review of the literature

CASE PRESENTATION

A 3-year-and-6-month-old child was reported to have recurrent high fever with generalized lymph node enlargement and significant elevation of inflammatory markers such as C-reactive protein and procalcitonin in tests. Later, whole exome sequencing determined that the child's disease was haploinsufficiency of A20 (HA20).

RESULTS

After immunosuppressive therapy, the child's symptoms improved significantly, and the inflammatory markers dropped to the normal range.

CONCLUSION

Because of the characteristics of HA20, this disease is often underdiagnosed and misdiagnosed in clinical practice. By reporting this case of HA20 in a child, we hope to increase the awareness of this disease in the clinic.

Procalcitonin Use: Variation Across Hospitals and Trends Over Time

OBJECTIVES

Procalcitonin (PCT) is a relatively novel biomarker that may be superior to C-reactive protein (CRP) in identifying bacterial infection. PCT use in pediatric hospitals is relatively unknown. We aimed to evaluate PCT and CRP use, describe PCT testing variability across children's hospitals, and compare temporal rates of PCT and CRP testing for patients admitted with pneumonia, sepsis, or fever in young infants.

METHODS

In this multicenter cohort study, we identified children ≤18 years old hospitalized from 2014-2018 with pneumonia, sepsis, or fever in infants <2 months by using the Pediatric Health Information System. To determine use, we evaluated the proportion of encounters with PCT or CRP testing from 2017-2018. We generated heat maps to describe PCT use across hospitals. We also compared PCT and CRP rates over time from 2014 to 2018.

RESULTS

From 2017-2018, PCT testing occurred in 3988 of 34c231 (12%) hospitalizations. Febrile infants had the highest PCT testing proportion (18%), followed by sepsis (15%) and pneumonia (9%). There was across-hospital variability in PCT testing, particularly for febrile infants. Over time, the odds of PCT testing increased at a significantly greater rate than that of CRP.

CONCLUSIONS

Despite limited guideline recommendations for PCT testing during the study period, PCT use increased over time with across-hospital variability. For pneumonia and sepsis, given the importance of high-value care, we need to understand the impact of PCT on patient outcomes. With recent guidelines recommending PCT in the evaluation of febrile infants, we identified baseline testing behaviors for future studies on guideline impact.

Umbilical Cord Procalcitonin to Detect Early-Onset Sepsis in Newborns: A Promising Biomarker

Background: Up to 7% of neonates born in high-income countries receive antibiotics for suspected early-onset sepsis (EOS). Culture-proven neonatal sepsis has a prevalence of 0.2%, suggesting considerable overtreatment. We studied the diagnostic accuracy of umbilical cord blood and infant blood procalcitonin (PCT) in diagnosing EOS to improve antibiotic stewardship. Methods: Umbilical cord blood PCT was tested in newborns ≥ 32 weeks of gestation. Groups were defined as following: A) culture-proven or probable EOS (n = 25); B) Possible EOS, based on risk factors for which antibiotics were administered for <72 h (n = 49); C) Risk factor(s) for EOS without need for antibiotic treatment (n = 181); D) Healthy controls (n = 74). Additionally, venous or capillary blood PCT and C-reactive protein (CRP) were tested if blood drawing was necessary for standard care. Results: Between June 2019 and March 2021, 329 newborns were included. Umbilical cord blood PCT was significantly higher in group A than in group C and D. No difference between venous or arterial samples was found. Sensitivity and specificity for cord blood procalcitonin were 83 and 62%, respectively (cut-off 0.1 ng/mL). Antepartum maternal antibiotic administration was associated with decreased PCT levels in both cord blood and infant blood directly postpartum in all groups combined. Conclusion: Umbilical cord blood PCT levels are increased in newborns ≥32 weeks with a proven or probable EOS and low in newborns with risk factors for infection, but PCT seems not a reliable marker after maternal antibiotic treatment. PCT could be useful to distinguish infected from healthy newborns with or without EOS risk factors.

Comparing the Diagnostic Accuracy of Procalcitonin and C-Reactive Protein in Neonatal Sepsis: A Systematic Review

Neonatal sepsis remains a significant diagnostic challenge in newborn care. It has the potential to be disastrous, but precise diagnosis is difficult. No biomarker has yet demonstrated sufficient diagnostic accuracy to rule out sepsis when clinical suspicion exists. As a result, neonates with suspected sepsis are treated with empiric antibiotics. These unnecessary antibiotics promote bacterial antibiotic resistance, raise economic costs, and alter the composition of the gut microbiota. This study aimed to determine the diagnostic accuracy of procalcitonin in the prompt diagnosis of neonatal sepsis. Articles were systematically screened in PubMed/MEDLINE, PubMed Central (PMC), and ScienceDirect, using keywords and Medical Subject Heading (MeSH) terms to identify the relevant articles. Additionally, one article from the Indian Journal of Applied Research was also used. Inclusion/exclusion criteria were applied post article screening via title and abstracts. Quality appraisal check was done using the Scale for the Assessment of Narrative Review Articles (SANRA) checklist, A Measurement Tool to Assess Systematic Reviews (AMSTAR) checklist, and Newcastle-Ottawa checklist. Six related articles were strictly reviewed. Procalcitonin is a useful biomarker in the early diagnosis of neonatal sepsis. Because procalcitonin has a better correlation with proven sepsis and is an early biomarker in diagnosing neonatal sepsis, it should be included in the overall sepsis evaluation. Future clinical trials on optimal cut-off levels of procalcitonin with shifting neonatal ages and its use in the post-op setting are needed.

Cost impact of procalcitonin-guided decision making on duration of antibiotic therapy for suspected early-onset sepsis in neonates

BACKGROUNDS

The large, international, randomized controlled NeoPInS trial showed that procalcitonin (PCT)-guided decision making was superior to standard care in reducing the duration of antibiotic therapy and hospitalization in neonates suspected of early-onset sepsis (EOS), without increased adverse events. This study aimed to perform a cost-minimization study of the NeoPInS trial, comparing health care costs of standard care and PCT-guided decision making based on the NeoPInS algorithm, and to analyze subgroups based on country, risk category and gestational age.

METHODS

Data from the NeoPInS trial in neonates born after 34 weeks of gestational age with suspected EOS in the first 72 h of life requiring antibiotic therapy were used. We performed a cost-minimization study of health care costs, comparing standard care to PCT-guided decision making.

RESULTS

In total, 1489 neonates were included in the study, of which 754 were treated according to PCT-guided decision making and 735 received standard care. Mean health care costs of PCT-guided decision making were not significantly different from costs of standard care (€3649 vs. €3616). Considering subgroups, we found a significant reduction in health care costs of PCT-guided decision making for risk category 'infection unlikely' and for gestational age ≥ 37 weeks in the Netherlands, Switzerland and the Czech Republic, and for gestational age < 37 weeks in the Czech Republic.

CONCLUSIONS

Health care costs of PCT-guided decision making of term and late-preterm neonates with suspected EOS are not significantly different from costs of standard care. Significant cost reduction was found for risk category 'infection unlikely,' and is affected by both the price of PCT-testing and (prolonged) hospitalization due to SAEs.

Utility of P-SEP, sTREM-1 and suPAR as Novel Sepsis Biomarkers in SARS-CoV-2 Infection

The coronavirus disease 2019 is a highly contagious viral infection caused by SARS-CoV-2 virus, member of coronaviridae family. It causes life threatening complications due to complexity and rapid onset course of the disease. Early identification of high-risk patients who require close monitoring and aggressive treatment remains challengeable till date. Novel biomarkers which help to identify high risk patients at the early stage is high priority. Objective of this review to find utility of P-SEP, sTREM-1 and suPAR for diagnosis, risk stratification and prognosis of SARS-CoV-2 infected cases. Soluble receptors like, P-SEP, sTREM-1 and suPAR have been involved in immune regulation in SARS-CoV-2 infection and elevate more in severe cases. A comprehensive research of databases like PubMed, EMBASE, CNKI and Web of Science was performed for relevant studies. A total of nine out of fifteen research literature in initial screening were included for this review. Interestingly all studies have reported high levels of P-SEP, sTREM-1 and suPAR in SARS-CoV-2 infected cases and the biomarkers positively correlated with severity of infection. This implies that P-SEP, sTREM-1 and suPAR can be implemented as surrogate marker in blood profile for early diagnosis, risk stratification and prognosis in SARS-CoV-2 for better management in Indian population at the current situation.

A Novel Framework for Phenotyping Children With Suspected or Confirmed Infection for Future Biomarker Studies

Background: The limited diagnostic accuracy of biomarkers in children at risk of a serious bacterial infection (SBI) might be due to the imperfect reference standard of SBI. We aimed to evaluate the diagnostic performance of a new classification algorithm for biomarker discovery in children at risk of SBI. Methods: We used data from five previously published, prospective observational biomarker discovery studies, which included patients aged 0- <16 years: the Alder Hey emergency department (n = 1,120), Alder Hey pediatric intensive care unit (n = 355), Erasmus emergency department (n = 1,993), Maasstad emergency department (n = 714) and St. Mary's hospital (n = 200) cohorts. Biomarkers including procalcitonin (PCT) (4 cohorts), neutrophil gelatinase-associated lipocalin-2 (NGAL) (3 cohorts) and resistin (2 cohorts) were compared for their ability to classify patients according to current standards (dichotomous classification of SBI vs. non-SBI), vs. a proposed PERFORM classification algorithm that assign patients to one of eleven categories. These categories were based on clinical phenotype, test outcomes and C-reactive protein level and accounted for the uncertainty of final diagnosis in many febrile children. The success of the biomarkers was measured by the Area under the receiver operating Curves (AUCs) when they were used individually or in combination. Results: Using the new PERFORM classification system, patients with clinically confident bacterial diagnosis ("definite bacterial" category) had significantly higher levels of PCT, NGAL and resistin compared with those with a clinically confident viral diagnosis ("definite viral" category). Patients with diagnostic uncertainty had biomarker concentrations that varied across the spectrum. AUCs were higher for classification of "definite bacterial" vs. "definite viral" following the PERFORM algorithm than using the "SBI" vs. "non-SBI" classification; summary AUC for PCT was 0.77 (95% CI 0.72-0.82) vs. 0.70 (95% CI 0.65-0.75); for NGAL this was 0.80 (95% CI 0.69-0.91) vs. 0.70 (95% CI 0.58-0.81); for resistin this was 0.68 (95% CI 0.61-0.75) vs. 0.64 (0.58-0.69) The three biomarkers combined had summary AUC of 0.83 (0.77-0.89) for "definite bacterial" vs. "definite viral" infections and 0.71 (0.67-0.74) for "SBI" vs. "non-SBI." Conclusion: Biomarkers of bacterial infection were strongly associated with the diagnostic categories using the PERFORM classification system in five independent cohorts. Our proposed algorithm provides a novel framework for phenotyping children with suspected or confirmed infection for future biomarker studies.

Serum amyloid A - A prime candidate for identification of neonatal sepsis

Neonatal sepsis is common, lethal, and hard to diagnose. In combination with clinical findings and blood culture, biomarkers are crucial to make the correct diagnose. A Swedish national inquiry indicated that neonatologists were not quite satisfied with the available biomarkers. We assessed the kinetics of 15 biomarkers simultaneously: ferritin, fibrinogen, granulocyte colony-stimulating factor (G-CSF), interferon (IFN)-γ, interleukin (IL)-1β, -6, -8, -10, macrophage inflammatory protein (MIP)-1β, procalcitonin, resistin, serum amyloid A (SAA), tumor necrosis factor (TNF)-α, tissue plasminogen activator-3 and visfatin. The goal was to observe how quickly they rise in response to infection, and for how long they remain elevated. From a neonatal intensive care unit, newborns ≥28 weeks gestational age were recruited. Sixty-eight newborns were recruited to the study group (SG), and fifty-one to the control group (CG). The study group subjects were divided into three subgroups depending on clinical findings: confirmed sepsis (CSG), suspected sepsis (SSG) and no sepsis. CSG and SSG were also merged into an entire sepsis group (ESG) for sub-analysis. Blood samples were collected at three time-points; 0 h, 12-24 h and 48-72 h, in order to mimic a "clinical setting". At 0 h, visfatin was elevated in SSG compared to CG; G-CSF, IFN-γ, IL-1β, -8 and - 10 were elevated in SSG and ESG compared to CG, whereas IL-6 and SAA were elevated in all groups compared to CG. At 12-24 h, IL-8 was elevated in ESG compared to CG, visfatin was elevated in ESG and SSG compared to CG, and SAA was elevated in all three groups compared to CG. At 48-72 h, fibrinogen was elevated in ESG compared to CG, IFN-γ and IL-1β were elevated in SSG and ESG compared to CG, whereas IL-8 and SAA were elevated in all three groups compared to CG. A function of time-formula is introduced as a tool for theoretical prediction of biomarker levels at any time-point. We conclude that SAA has the most favorable kinetics regarding diagnosing neonatal sepsis, of the biomarkers studied. It is also readily available methodologically, making it a prime candidate for clinical use.

One-step-immunoassay of procalcitonin enables rapid and accurate diagnosis of bacterial infection

Procalcitonin (PCT) (i.e. a precursor of calcitonin) attracts much attention as a reliable biomarker of bacterial infections because its concentration increases rapidly in the blood when bacterial infections occur in the body. Sepsis may occur due to indiscriminate and vigorous proliferation of infectious bacteria, and accordingly early diagnosis and treatment of bacterial infection are of crucial importance. However, current diagnostic methods for sepsis suffer from long assay time, multiple and complex assay steps, inaccuracy, and requirement of analytical equipments. The goal of this study is to develop an advanced one-step-immunoassay that enables quick and accurate diagnosis of sepsis through measuring the PCT concentration in patient sera, which is based on self-enhancement of optical detection signals from large gold particles (i.e. clusters of gold nanoparticles) that are formed on the agglomerates of PCT-bound 3-dimensional (3D) probes. The 3D probe is constructed through attaching polyclonal anti-PCT antibodies (IgGs) to the surface of a modified hepatitis B virus (HBV) capsid, where both tandem repeats of the B domain of Staphylococcal protein A (SPA_B) and the hexa-histidine tag are inserted into each HBV core protein (i.e. subunit of HBV capsid). That is, anti-PCT IgGs are attached via strong interaction between the Fc region and surface-exposed SPA_B. Furthermore, hook effect-free and PCT concentration-dependent optical signals were consistently generated by adding both bovine serum albumin (BSA) and nickel ions to patient sera and also by optimally adjusting the 3D probe concentration. Compared to conventional chemiluminescent microparticle immunoassay (CMIA) showing poor linearity of detection signals, this novel immunoassay accurately detected PCT with good linearity between PCT concentrations and optical signals in a wide range of PCT concentrations (0.05–200 ng mL⁻¹) and also showed a sufficiently low limit of detection, resulting in 100% sensitivity and 100% specificity when tested with 30 sepsis patients and 30 healthy individuals.

An advanced one-step-immunoassay enables quick and accurate diagnosis of sepsis with generation of clear optical signals in assay solution, which is based on sensitive detection of procalcitonin in patient sera.

Novel point-of-care biomarker combination tests to differentiate acute bacterial from viral respiratory tract infections to guide antibiotic prescribing: a systematic review

BACKGROUND

Acute respiratory tract infections (RTIs) are the most common reason to seek medical care, with many patients receiving inappropriate antibiotics. Novel testing approaches to identify aetiology at the point-of-care are required to accurately guide antibiotic treatment.

OBJECTIVE

To assess the diagnostic accuracy of biomarker combinations to rapidly differentiate between acute bacterial or viral RTI aetiology.

DATA SOURCES

MEDLINE, Embase and Web of Science databases were searched to February 2021.

STUDY ELIGIBILITY CRITERIA

Diagnostic accuracy studies comparing accuracy of point-of-care and rapid diagnostic tests in primary or secondary care, consisting of biomarker combinations, to identify bacterial or viral aetiology of RTI.

METHODS

Risk of bias was assessed using the QUADAS-2 tool. Sensitivity and specificity of tests reported by more than one study were meta-analysed using a random effects model.

RESULTS

Twenty observational studies (3514 patients) were identified. Eighteen were judged at high risk of bias. For bacterial aetiologies, sensitivity ranged from 61% to 100% and specificity from 18% to 96%. For viral aetiologies, sensitivity ranged from 59% to 97% and specificity from 74% to 100%. Studies evaluating two commercial tests were meta-analysed. For ImmunoXpert, the summary sensitivity and specificity were 85% (95% CI 75%-91%, k = 4) and 86% (95% CI 73%-93%, k = 4) for bacterial infections, and 90% (95% CI 79%-96%, k = 3) and 92% (95% CI 83%-96%, k = 3) for viral infections, respectively. FebriDx had pooled sensitivity and specificity of 84% (95% CI 75%-90%, k = 4) and 93% (95% CI 90%-95%, k = 4) for bacterial infections, and 87% (95% CI 72%-95%; k = 4) and 82% (95% CI 66%-86%, k = 4) for viral infections, respectively.

CONCLUSION

Combinations of biomarkers show potential clinical utility in discriminating the aetiology of RTIs. However, the limitations in the evidence base, due to a high proportion of studies with high risk of bias, preclude firm conclusions. Future research should be in primary care and evaluate patient outcomes and cost-effectiveness with experimental study designs.

CLINICAL TRIAL

PROSPERO registration number: CRD42020178973.

Neonatal Levels of Acute Phase Proteins and Risk of Autism Spectrum Disorder

BACKGROUND

Immune signaling pathways influence neurodevelopment and are hypothesized to contribute to the etiology of autism spectrum disorder (ASD). We aimed to assess risk of ASD in relation to levels of neonatal acute phase proteins (APPs), key components of innate immune function, measured in neonatal dried blood spots.

METHODS

We included 924 ASD cases, 1092 unaffected population-based controls, and 203 unaffected siblings of ASD cases in this case-control study nested within the register-based Stockholm Youth Cohort. Concentrations of 9 different APPs were measured in eluates from neonatal dried blood spots from cases, controls, and siblings using a bead-based multiplex assay.

RESULTS

Neonatal C-reactive protein was consistently associated with odds of ASD in case-control comparisons, with higher odds associated with the highest quintile compared with the middle quintile (odds ratio [OR] = 1.50, 95% confidence interval [CI] = 1.10-2.04) in adjusted analyses. In contrast, the lowest quintiles of α-2-macroglobulin (OR = 3.71, CI = 1.21-11.33), ferritin (OR = 4.20, CI = 1.40-12.65), and serum amyloid P (OR = 3.05, CI = 1.16-8.01) were associated with odds of ASD in the matched sibling comparison. Neonatal APPs varied with perinatal environmental factors and maternal/fetal phenotypes. Significant interactions in terms of risk for ASD were observed between neonatal APPs and maternal infection during late pregnancy, maternal anemia, and maternal psychiatric history.

CONCLUSIONS

Indicators of the neonatal innate immune response are associated with risk of ASD, although the nature of these associations varies considerably with factors in the perinatal environment and the genetic background of the comparison group.

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.

Sepsis Biomarkers

Biomarkers have been used in sepsis to assist with the diagnosis of disease as well as determining the severity of disease, that is, prognosis. These biomarkers are based on the presence of discrete molecules within the blood. Unfortunately, in 2020, a single biomarker does not have sufficient sensitivity and specificity to definitively rule in or rule out sepsis. Biomarkers have shown better performance in animal models of disease.

Diagnostic Accuracy of Infection Markers to Diagnose Infections in Neonates and Children Receiving Extracorporeal Membrane Oxygenation

BACKGROUND

Infections represent one of the most common complications in patients managed on Extracorporeal Membrane Oxygenation (ECMO) and are associated with poorer outcomes. Clinical signs of infection in patients on ECMO are non-specific. We assessed the diagnostic accuracy of Procalcitonin (PCT), C-reactive protein (CRP) and White cell count (WCC) to diagnose infection on ECMO.

METHODS

Retrospective single center observational study including neonates and children <18 years treated with ECMO in 2015 and 2016. Daily data on PCT, CRP and WCC were assessed in relation to microbiologically confirmed, and clinically suspected infection on ECMO using operating characteristics (ROC) curves.

RESULTS

Sixty-five ECMO runs in 58 patients were assessed. CRP had the best accuracy with an area under the ROC curve (AUC) of 0.79 (95%-CI 0.66-0.92) to diagnose confirmed infection and an AUC of 0.72 (0.61-0.84) to diagnose confirmed and suspected infection. Abnormal WCC performed slightly worse with an AUC of 0.70 (0.59-0.81) for confirmed and AUC of 0.66 (0.57-0.75) for confirmed and suspected infections. PCT was non-discriminatory.

CONCLUSION

The diagnosis of infections acquired during ECMO remains challenging. Larger prospective studies are needed that also include novel infection markers to improve recognition of infection in patients on ECMO.

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.

The value of interleukin-6 (IL-6) within 6 hours after birth in the prompt diagnosis of early-onset neonatal sepsis

BACKGROUND

To investigate the value of interleukin-6 (IL-6) for neonates within 6 hours after birth in the prompt diagnosis of early-onset neonatal sepsis (EONS).

METHODS

The clinical and laboratory data of 129 neonates in the neonatal intensive care unit (NICU) of our center from March 31, 2017, to February 29, 2020, were retrospectively analyzed. These patients were divided into two groups on their disease conditions: the EONS group (n=66) and the healthy control group (n=63). All enrolled patients were born in our hospital's Obstetrics Department and were admitted to the NICU within 2 hours after birth. The first session of the blood test was conducted within 4-6 hours after birth for the measurements of IL-6, C-reactive protein (CRP1), serum amyloid A1 (SAA1), and serum immunoglobulin M (IgM). The second session of the blood test was performed 12-24 hours after birth for procalcitonin (PCT), CRP2, and SAA2. All the tests were completed in our clinical laboratory. The non-parametric test (Mann-Whitney U test) was used to compare all parameters between these two groups. The receiver operating characteristic (ROC) curves were drawn to compare the diagnostic sensitivities and specificities. The pairwise comparisons of the ROC curves were on the MedCalc18.2.1 software. A P value of <0.05 was considered statistically significant.

RESULTS

Gender, birth weight, and gestational age were matched between the EONS group and the control group (all P>0.05). The differences of IL-6, CRP2, PCT, and SAA2 were statistically significant between these two groups (all P<0.05), while there was no significant difference in CRP1, SAA1, and IgM (all P>0.05). The area under the ROC curve (AUC) is 1 (95% CI: 0.918-1.000), 1 (95% CI: 0.918-1.000), 1 (95% CI: 0.918-1.000), and 0.977 (95% CI: 0.878-0.999), respectively, for IL-6, CRP2, PCT, and SAA2. Pairwise comparisons among four biomarkers showed the diagnostic specificity and sensitivity of IL-6 were not significantly different from those of CRP2, PCT, and SAA2 (all P>0.05).

CONCLUSIONS

IL-6 is a quick and independent diagnostic biomarker for EONS, and its sensitivity and specificity are inferior to the conventional inflammation markers, including CRP, PCT, and SAA.

New reference ranges of procalcitonin excluding respiratory failure in neonates

BACKGROUND

Existing reference data on serum procalcitonin (PCT) in neonates include the effects of respiratory disorders commonly occurring during birth. We aimed to determine new 95% reference intervals in neonates after excluding the influence of respiratory failure at birth, and to investigate the effects of gestational age (GA) and respiratory condition at birth on postnatal transient serum PCT elevation.

METHODS

Samples were obtained from term and preterm neonates during the first 3 days of life. Neonates were classified into reference, respiratory failure, and bacterial infection groups. In the reference group, the correlation between PCT level and GA was investigated.

RESULTS

The median PCT level within the 95% range 12-36 h after birth was 1.05 ng/mL (0.14-4.39) in term neonates (143 samples) and 1.01 ng/mL (0.15-4.44) in preterm neonates (95 samples). There was no correlation between GA and serum PCT level during 1-48 h after birth. There was a significant difference in median serum PCT level during 12-36 h after birth between the respiratory failure (9.56 ng/mL) and bacterial infection (49.82 ng/mL) groups in preterm neonates but no difference between term neonates (respiratory failure 6.83 ng/mL, and bacterial infection 7.43 ng/mL).

CONCLUSIONS

Respiratory failure is the main effector for the transient elevation in serum PCT levels at 3 days of life. After excluding the influence of respiratory failure, the chronological pattern and range were very similar between term and preterm neonates. Procalcitonin can be useful for clinicians in distinguishing bacterial infection from respiratory failure, aiding decisions on appropriate antibiotic use.

Clinical values of common biomarkers for efficacy monitoring of antibiotics in early-onset neonatal sepsis

BACKGROUND

To investigate the clinical values of the common biomarkers including blood routine (B-Rt), C-reactive protein (CRP), serum amyloid A (SAA) and procalcitonin (PCT) for efficacy monitoring of antibiotics in early-onset neonatal sepsis (EONS).

METHODS

The clinical and laboratory data of 78 neonates with confirmed EONS in the neonatal intensive care unit (NICU) of our center from July 1, 2019 to June 30, 2020 were retrospectively analyzed. All the subjects were treated with cefotiam (50 mg/kg q12h) and augmentin (30 mg/kg q12h) within 12 hours after birth. Blood samples were collected 0-12 hours after birth for blood culture, measurements of B-Rt, CRP and SAA. Subsequently, blood sampling was performed at intervals of 12-24, 24-48, 48-96, and 96-144 hours for measurements of B-Rt, CRP, SAA and PCT. Statistical analyses were performed in the SPSS 20.0 software package. P value of <0.05 was considered statistically significant.

RESULTS

WBC count showed no significant change among different intervals (12-24, 24-48, 48-96, and 96-144 hours); in contrast, NEU%, CRP, SAA and PCT significantly differed across all intervals. SAA had sensitivities of 75.86%, 93.1%, 44.83%, and 3.45%, respectively; specificities of 100% across all intervals; and AUCs of 0.879 (P<0.0001), 0.966 (P<0.0001), 0.724 (P<0.0001), and 0.500, respectively (P=1). PCT had sensitivities of 100%, 100%, 79.31%, and 51.72%, respectively; specificities of 100% across all intervals; and AUCs of 1 (P<0.0001), 1 (P<0.0001), 0.793 (P<0.0001), and 0.517 (P>0.8551), respectively.

CONCLUSIONS

WBC count, NEU% and CRP showed no clinical significance for any intervals for efficacy monitoring of antibiotic treatment. SAA and PCT had similar monitoring values at 12-24 and 24-48 hours. SAA is thus more valuable than PCT for efficacy monitoring of antibiotics at the 48-96 and even at the 96-144 hours intervals in EONS.

Differential Markers of Bacterial and Viral Infections in Children for Point-of-Care Testing

Children suffering from infectious diseases, both bacterial and viral, are often treated with empirical antibiotics. Keeping in mind both the menace of microorganisms and antibiotic toxicity, it is imperative to develop point-of-care testing (POCT) to discriminate bacterial from viral infections, and to define indications for antibiotic treatment. This article reviews potential protein biomarkers and host-derived gene expression signatures for differentiating between bacterial and viral infections in children, and focuses on emerging multiplex POCT devices for the simultaneous detection of sets of protein biomarkers or streamlined gene expression signatures that may provide rapid and cost-effective pathogen-discriminating tools.

Bacteria and viruses activate or inhibit different signaling pathways in the cells they infect, and further give rise to different host transcriptional signatures as well as to unique protein biomarkers.

Many of the newly evaluated protein biomarkers, especially in combination, have better discriminative value for distinguishing between bacterial and viral infections than the biomarkers that are currently used for examining infections in children.

The transcriptomes of children undergo remarkable changes when they are infected by different types of bacteria and viruses. Approaches based on host-derived DNA/RNA signatures can accurately discriminate bacterial from viral infections.

Emerging multiplex POCT techniques allow simultaneous testing of protein- or gene-based biomarkers in an outpatient setting.

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.

Using Machine Learning to Predict Bacteremia in Febrile Children Presented to the Emergency Department

Blood culture is frequently used to detect bacteremia in febrile children. However, a high rate of negative or false-positive blood culture results is common at the pediatric emergency department (PED). The aim of this study was to use machine learning to build a model that could predict bacteremia in febrile children. We conducted a retrospective case-control study of febrile children who presented to the PED from 2008 to 2015. We adopted machine learning methods and cost-sensitive learning to establish a predictive model of bacteremia. We enrolled 16,967 febrile children with blood culture tests during the eight-year study period. Only 146 febrile children had true bacteremia, and more than 99% of febrile children had a contaminant or negative blood culture result. The maximum area under the curve of logistic regression and support vector machines to predict bacteremia were 0.768 and 0.832, respectively. Using the predictive model, we can categorize febrile children by risk value into five classes. Class 5 had the highest probability of having bacteremia, while class 1 had no risk. Obtaining blood cultures in febrile children at the PED rarely identifies a causative pathogen. Prediction models can help physicians determine whether patients have bacteremia and may reduce unnecessary expenses.

Progranulin as a novel biomarker in diagnosis of early-onset neonatal sepsis

BACKGROUND

Infections are leading causes of morbidity and mortality in neonates and may also have severe long-term consequences. As early diagnosis of neonatal sepsis improves prognosis, identification of new or complementary biomarkers is of great importance. In this study, we have evaluated the diagnostic value of progranulin (PGRN) in early-onset neonatal sepsis (EOS) and compare its effectiveness with other commonly used biomarkers, such as procalcitonin (PCT) and C-reactive protein (CRP).

METHODS

A total of 121 infants with gestational age of >34 weeks admitted with suspected EOS were included in this study. Before initiating therapy, blood samples for whole blood count, CRP, PCT and PGRN were obtained from all neonates. Receiver-operating characteristic (ROC) curve and multivariate logistic regression analyses were performed.

RESULTS

Serum PGRN level of infected group was significantly higher than uninfected group (median 47.72 vs. 37.86 ng/ml, respectively; Mann-Whitney p < 0.0001). The ROC area under the curve (AUC) was 0.786 [95% confidence interval (CI) 0.706-0.867; p < 0.0001] for PGRN, 0.699 (95% CI 0.601-0.797; p = 0.0001) for age adjusted PCT, and 0.673 (95% CI 0.573-0.773; p = 0.0007) for CRP. With a cut-off value of 37.89 ng/ml, the diagnostic sensitivity and negative predictive value of PGRN were 94.34% and 91.7%, respectively. PGRN could significantly predict EOS independently of PCT (p < 0.0001), and the combined use of PGRN and PCT could significantly improve diagnostic performance for EOS (0.806; 95% CI 0.73-0.88; p < 0.0001), with a specificity of 89.06% and a positive predictive value of 81.10%.

CONCLUSIONS

PGRN may be used as a promising biomarker for the diagnosis of EOS, and the combined use of PGRN and PCT could improve the diagnosis of sepsis.

Management of Children With Fever at Risk for Pediatric Sepsis: A Prospective Study in Pediatric Emergency Care

Objective: To study warning signs of serious infections in febrile children presenting to PED, ascertain their risk of having sepsis, and evaluate their management. Design: Prospective observational study. Setting: A single pediatric emergency department (PED). Participants: Febrile children, aged 1 month-16 years, with >= 1 warning signs of sepsis. Interventions and Main outcome measures: Clinical characteristics, including different thresholds for tachycardia and tachypnoea, and their association with (1) delivery of pediatric sepsis 6 (PS6) interventions, (2) final diagnosis of invasive bacterial infection (IBI), (3) the risk for pediatric intensive care unit (PICU) admission, and (4) death. Results: Forty-one percent of 5,156 febrile children had warning signs of sepsis. 1,606 (34%) children had tachypnoea and 1,907 (39%) children had tachycardia when using APLS threshold values. Using the NICE sepsis guidelines thresholds resulted in 1,512 (32%) children having tachypnoea (kappa 0.56) and 2,769 (57%) children having tachycardia (kappa 0.66). Of 1,628 PED visits spanning 1,551 disease episodes, six children (0.4%) had IBI, with one death (0.06%), corresponding with 256 children requiring escalation of care according to sepsis guideline recommendations for each child with IBI. There were five additional PICU admissions (0.4%). 121 (7%) had intravenous antibiotics in PED; 39 children (2%) had an intravenous fluid bolus, inotrope drugs were started in one child. 440 children (27%) were reviewed by a senior clinician. In 4/11 children with IBI or PICU admission or death, PS6 interventions were delivered within 60 min after arriving. 1,062 (65%) visits had no PS6 interventions. Diagnostic performance of vital signs or sepsis criteria for predicting serious illness yielded a large proportion of false positives. Lactataemia was not associated with giving iv fluid boluses (p = 0.19) or presence of serious bacterial infections (p = 0.128). Conclusion: Many febrile children (41%) present with warning signs for sepsis, with only few of them undergoing investigations or treatment for true sepsis. Children with positive isolates in blood or CSF culture presented in a heterogeneous manner, with varying levels of urgency and severity of illness. Delivery of sepsis care can be improved in only a minority of children with IBI or admitted to PICU.

Procalcitonin for predicting catheter-associated bloodstream infection: A meta-analysis

OBJECTIVE

The predictive accuracies of procalcitonin (PCT) in the diagnosis of catheter-associated bloodstream infection (CABSI) vary widely. This meta-analysis aimed to explore the predictive value of PCT for CABSI.

METHODS

We searched PubMed, EMBase, Web of Science, ScienceDirect, Cochrane Library, and studies published up to 10 March 2019. Odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated to evaluate PCT predictive value using Stata 14.0 software.

RESULTS

The meta-analysis was composed of 7 studies, consisting of 347 subjects. Pooled analysis demonstrated that a high PCT was significantly correlated with CABSI (pooled OR = 23.36, 95%CI 12.43-43.91, P < .001) and medium heterogenicity (I = 36.9%, P = .147). The pooled sensitivity and specificity were 85% (95%CI 0.76-0.91) and 89% (95%CI 0.68-0.97), respectively. Although Begg funnel plot (P = .007) indicated the presence of publication bias among the included studies, the stability of the pooled outcomes was verified by the trim-and-fill method. Furthermore, sensitivity analyses did not show important differences in effect estimation.

CONCLUSION

PCT is an effective predictor of CABSI. However, high-quality randomized controlled trials are needed to determine whether PCT could predict CABSI.

Predictive value of serum procalcitonin for both initial and repeated immunoglobulin resistance in Kawasaki disease: a prospective cohort study

BACKGROUND

Intravenous immunoglobulin (IVIG) resistance prediction is one pivotal topic of interests in Kawasaki disease (KD) since those patients with KD resistant to IVIG might improve of an early-intensified therapy. Data regarding predictive value of procalcitonin (PCT) for IVIG resistance, particularly for repeated IVIG resistance in KD was limited. This study aimed to testify the predictive validity of PCT for both initial and repeated IVIG resistance in KD.

METHODS

A total of 530 KD patients were prospectively recruited between January 2015 and March 2019. The clinical and laboratory data were compared between IVIG-responsive and IVIG-resistant groups. Multivariate logistic regression analysis was applied to determine the association between PCT and IVIG resistance. Receiver operating characteristic (ROC) curves analysis was further performed to assess the validity of PCT in predicting both initial and repeated IVIG resistance.

RESULTS

The serum PCT level was significantly higher in initial IVIG-resistance group compared with IVIG-response group (p = 0.009), as well as between repeated IVIG responders and nonresponders (p = 0.017). The best PCT cutoff value for initial and repeated IVIG resistance prediction was 1.48 ng/ml and 2.88 ng/ml, respectively. The corresponding sensitivity was 53.9 and 51.4%, while the specificity were 71.8 and 73.2%, respectively. Multivariate logistic regression analysis failed to identify serum PCT level as an independent predictive factor for both initial and repeated IVIG resistance in KD.

CONCLUSIONS

Serum PCT levels were significantly higher in IVIG nonresponders, but PCT may not be suitable as a single marker to accurately predict both initial and repeated IVIG resistance in KD.

Host-response biomarkers for the diagnosis of bacterial respiratory tract infections

Appropriate antibiotic treatment for respiratory tract infections (RTIs) necessitates rapid and accurate diagnosis of microbial etiology, which remains challenging despite recent innovations. Several host response-based biomarkers due to infection have been suggested to allow discrimination of bacterial and non-bacterial microbial RTI etiology. This review provides an overview of clinical studies that investigated the diagnostic performance of host-response proteomic biomarkers to identify RTI microbial etiology. Procalcitonin and C-reactive protein have been studied most extensively; whereof procalcitonin has demonstrated the strongest diagnostic performance compared to other biomarkers. Proadrenomedullin, soluble triggering receptor expressed on myeloid cells-1, neopterin and pentraxin-3 need more studies to confirm their diagnostic value. For syndecan-4 and lipocalin-2 currently insufficient evidence exists. Common limitations in several of the studies were the relatively small scale setting, heterogeneous patient population and the absence of statistical power calculation.

Analytical performances of a novel point-of-care procalcitonin assay

Objectives

We report the analytical performances of a new point-of-care (POC) procalcitonin (PCT) fluorescence immunoassay that uses the AFIAS-6© system from Boditech and its concordance with results of the standard method Kryptor Compact plus from the central laboratory.

Design

and methods: Analytical performances including imprecision studies, limit of blank (LoB), limit of detection (LoD) and limit of quantification (LOQ) were determined. The method comparison was performed using plasma vs. whole blood for Kryptor CompactPlus© vs. AFIAS-6©, respectively.

Results

The total imprecision was far from the CV of 4.5% claimed by the manufacturer and close to 10%, for levels of PCT at 0.4 and 8.3 μg/L. The LoD of this novel PCT assay was found to close to the LoD provided by the manufacturer at 0.04 μg/L. The LOQ was higher than that claimed by the manufacturer (0.1 vs 0.002, respectively). The equation of linearity in the lower range was found to be y = 1.056x - 0.039 with r² = 0.993 with a mean recovery percentage of 86 ± 15%. Correlation studies showed a good correlation between PCT measurements using plasma on Kryptor system and on corresponding whole blood with POC reaching a bias of -0.04 in the range from 0.02 to 2 μg/L.

Conclusion

The novel PCT assay on AFIAS-6© is an acceptable POC alternative for the diagnosis and management of sepsis at EDs to improve the flow of patients, as results are consistent with those of the standard PCT Kryptor Compact Plus© assay, despite its higher imprecision.

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.

Presepsin as a diagnostic marker of sepsis in children and adolescents: a systemic review and meta-analysis

Background

Early diagnosis of sepsis in pediatric patients is vital but remains a major challenge. Previous studies showed that presepsin is potentially a reliable diagnostic biomarker for sepsis in adult and neonates. However, there is no pooled analysis of its efficacy as a diagnostic biomarker for sepsis in children. The aims of the present meta-analysis were to assess the overall diagnostic accuracy of presepsin in pediatric sepsis and compare it to those for C-reactive protein (CRP) and procalcitonin (PCT).

Methods

A systematic literature search was performed in Medline/Pubmed, Embase, the Cochrane Library, and ISI Web of Science to identify relevant studies reporting the diagnostic accuracy of presepsin in patients with pediatric sepsis. Sensitivities and specificities were pooled by bivariate meta-analysis. Heterogeneity was evaluated by χ² test.

Results

We identified 129 studies in total. Most were disqualified on the basis of their titles/abstracts and duplication. Four studies were included in the final analysis. They comprised 308 patients aged between 1 mo and 18 y. The pooled diagnostic sensitivity and specificity of presepsin were 0.94 (95% confidence interval [CI]: 0.74–0.99) and 0.71 (95% CI: 0.35–0.92), respectively. The pooled diagnostic odds ratio, positive likelihood ratio (LR), and negative LR of presepsin were 32.87 (95% CI: 2.12–510.09), 3.24 (95% CI, 1.14–12.38), and 0.08 (95% CI, 0.01–0.74), respectively. Heterogeneity was found in both sensitivity (χ² = 11.17; P = 0.011) and specificity (χ² = 65.78; P < 0.001). No threshold effect was identified among the studies (r = − 0.938). The pooled sensitivity of presepsin (0.94) was higher than that of CRP (0.51) and PCT (0.76), whereas the overall specificity of presepsin (0.71) was lower than that of CRP (0.81) and PCT (0.76). The AUC of presepsin (0.925) was higher than that of CRP (0.715) and PCT (0.820).

Conclusion

Currently available evidence indicates that presepsin has higher sensitivity and diagnostic accuracy, but lower specificity, than PCT or CRP in detecting sepsis in children. However, these results must be carefully interpreted as the number of studies included was small and the studies were statistically heterogeneous.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4397-1) contains supplementary material, which is available to authorized users.

Establishment of reference intervals for maternal blood and umbilical cord blood procalcitonin in healthy Chinese women in late pregnancy

AIM

To establish reference intervals (RIs) for maternal blood and umbilical cord blood procalcitonin (PCT) in healthy Chinese women in late pregnancy.

METHODS

One hundred and twenty-seven healthy Chinese women in late pregnancy, including 70 vaginal deliveries and 57 cesarean section deliveries, were retrospectively analyzed. These pregnant women gave birth to 58 male infants and 69 female infants. Another 127 age-matched healthy women who were not pregnant were enrolled as the control group. PCT levels in maternal blood, umbilical cord blood and control blood were determined using electrochemiluminescence immunoassay. The RIs of PCT were defined using an intermediate 95% interval.

RESULTS

The RIs for maternal blood and umbilical cord blood PCT were 0.020-0.075 ng/mL and 0.020-0.159 ng/mL, respectively. The cord blood PCT level was not significantly different between different delivery methods (P > 0.05). In contrast, the umbilical cord blood PCT in female newborns was higher than that in male newborns (0.088 ± 0.046 ng/mL vs 0.072 ± 0.030 ng/mL, P < 0.05).

CONCLUSION

Maternal blood and umbilical cord blood PCT of Chinese women in late pregnancy have different RIs, and umbilical cord blood PCT level is affected by the gender of newborns.

Management of febrile infants aged 1 month and less than 3 months in a French university hospital: Clinical practice evaluation

BACKGROUND

Management of febrile infants is challenging due to the increased risk of serious bacterial infections and it varies among physicians and hospitals. The goals of this study were to describe and compare the management of febrile infants aged 1-2 months in a hospital in 2011 and 2016.

METHODS

We conducted a retrospective study in the Bordeaux Pellegrin University Hospital, France, in 2011 and 2016. All infants aged 1-2 months with diagnosis codes referring to fever were included. Data on infant characteristics, fever episodes, clinical symptoms, and management were collected from medical charts. Univariate analyses and multivariate logistic models were used.

RESULTS

A total of 530 infants were included; 89.2% had blood testing and 81.1% urine testing; 79.6% of the infants were hospitalized, three of them in the pediatric intensive care unit. The median hospitalization duration was 3 days. In the sample investigated, 59.8% of the infants received antibiotic therapy and 128 (24.1%) had bacterial infections with no difference between 2011 and 2016. The main bacterial infection was pyelonephritis (86.7%). Urethral catheterization was implemented in 2016, whereas a urine bag was utilized for 174 out of 177 infants in 2011. The percentage of contaminated urine cultures was higher in 2011 (35.9%) than in 2016 (19.6%, P<0.001). The hospitalization rate was higher in 2016.

CONCLUSIONS

Management of febrile infants changed between 2011 and 2016. The hospitalization rate and antibiotic therapy use remained high regarding the rate of bacterial infection. Use of urethral catheterization decreased the level of contamination.

Cord blood procalcitonin level and early-onset sepsis in extremely preterm infants

Early-onset neonatal sepsis (EOS) is observed in 1.7% of extremely preterm infants, with high morbidity and mortality rate. Cord blood procalcitonin (PCT) is a sensitive marker of EOS in full-term newborns, but it has been rarely studied in premature infants. The diagnostic value of cord blood PCT by immunofluorescence has been assessed as an early marker of EOS in a prospective cohort of extremely preterm infants, with a threshold at 0.5 μg/L. EOS was defined by a positive bacterial culture or by the association of postnatal biological/clinical signs of EOS and antibiotic treatment for more than 72 h. Correlation between PCT serum concentrations and postnatal morbidities was also analyzed. Among a total of 186 infants, 45 (24%) were classified as EOS. Blood PCT concentration was ≤ 0.5 μg/L in 114 infants, including 11 EOS (9.6%) and PCT was > 0.5 μg/L in 72 babies including 34 EOS (47.2%). PCT concentration > 0.5 μg/L was associated with higher risk of EOS (OR 2.18; CI95% 1.58-3.02; p < 0.0001). The receiver operating characteristic curve determined a cutoff of 0.7 μg/L as the best compromise, with an area under the curve of 0.75 (sensitivity 69%, specificity 70%). In multivariate analysis, clinical chorioamnionitis was associated with PCT concentration > 0.5 μg/L (OR 2.58; CI95% 1.35-4.94; p = 0.004). Cord blood PCT is a marker significantly associated with EOS in extremely preterm infants, but its sensitivity remains low. Its added value in combination with other early marker of EOS needs to be further investigated in this high-risk population.