Cord blood plasma reference intervals for potential sepsis markers: pro-adrenomedullin, pro-endothelin, and pro-atrial natriuretic peptide

Clinical Potential of Adrenomedullin Signaling in the Cardiovascular System

Numerous clinical studies have revealed the utility of circulating AM (adrenomedullin) or MR-proAM (mid-regional proAM 45-92) as an effective prognostic and diagnostic biomarker for a variety of cardiovascular-related pathophysiologies. Thus, there is strong supporting evidence encouraging the exploration of the AM-CLR (calcitonin receptor-like receptor) signaling pathway as a therapeutic target. This is further bolstered because several drugs targeting the shared CGRP (calcitonin gene-related peptide)-CLR pathway are already Food and Drug Administration-approved and on the market for the treatment of migraine. In this review, we summarize the AM-CLR signaling pathway and its modulatory mechanisms and provide an overview of the current understanding of the physiological and pathological roles of AM-CLR signaling and the yet untapped potentials of AM as a biomarker or therapeutic target in cardiac and vascular diseases and provide an outlook on the recently emerged strategies that may provide further boost to the possible clinical applications of AM signaling.

Diagnostic value of mid-regional pro-Adrenomedullin as a biomarker of invasive bacterial infection in children: a systematic review

Background

Invasive bacterial infections (IBI) in children present a difficult clinical challenge. They are often life-threatening, however in the early stages they can be hard to differentiate from benign viral infections. This leaves clinicians with the risk of missing a serious IBI diagnosis or inappropriately using antimicrobials in a child with a viral infection- contributing to the ongoing development of increased antimicrobial resistance. Hence, biomarkers which could aid in early detection of IBI and differentiation from viral infections are desirable. Mid-Regional pro-Adrenomedullin (MR-proADM) is a biomarker which has been associated with IBI. The aim of this systematic review was to determine its diagnostic accuracy in identifying children with IBI.

Methods

A strategy was devised to search online databases MEDLINE, Embase, Web of Science and Scopus for human clinical trials reporting the accuracy of MR-proADM in children. Against predesigned inclusion and exclusion criteria full texts were selected for inclusion and data extraction. True positives, false positives, true negatives and false negatives were extracted from each included study to fill 2 × 2 tables. Using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool methodological quality of each study was assessed.

Results

A total of 501 articles were initially identified. After the removal of duplicates and abstract screening 11 texts were fully reviewed and four texts (totaling 1404 patients) were included in the systematic analysis. Only one study was of a high quality and that study accounted for the vast majority of patients. A single study reported the diagnostic accuracy of MR-proADM for invasive bacterial infection reporting an Area under the Curve of 0.69. The paucity of available studies made meta-analysis and studies of heterogeneity impossible.

Conclusion

There is a paucity of research regarding the diagnostic accuracy of MR-proADM in the diagnosis of invasive bacterial infections in children. Initial results would suggest that MR-proADM testing alone is poor at identifying IBI in young children. It remains unclear if MR-proADM performs differently in older children or in children with signs and symptoms of IBI.

Trial registration

PROSPERO CRD42018096295.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03255-9.

Proadrenomedullin and neonatal sepsis: a systematic review and meta-analysis of diagnostic accuracy

The association of proadrenomedullin and neonatal sepsis has been examined in numerous studies. The object of our meta-analysis is to evaluate differences in proadrenomedullin among neonates with sepsis and health neonates. We systematically searched the following databases: MEDLINE, Clinicaltrials.gov, Cochrane Central Register of Controlled Trials (CENTRAL), Google Scholar, and WHO (International Clinical Trials Register Platform) using a structured algorithm. Statistical analysis was conducted using Revman 5.3 and R software. Included studies in the meta-analysis were assessed using the Newcastle-Ottawa scale. Proadrenomedullin levels were found significantly higher in neonates with sepsis than healthy neonates with an SMD equal with 3.07 [95% CI 1.71, 4.42 (p < 10^-5, I² = 98%)]. The optimal cutoff point of pro-ADM was calculated at 17.559 with a sensitivity of 0.879 (0.458; 0.984) and a specificity of 0.994 (0.820; 1.000), and an AUC of 0.905. Subgroup analysis, leave-one-out meta-analysis, and meta-regression were performed in an effort to lower inter-study heterogeneity. Sensitivity analysis was conducted by excluding high risk of bias studies and those contributing to the overall heterogeneity shown by the Baujat plot. Publication bias was assessed using a funnel plot and the trim-and-fill method. Certainty assessment was evaluated using the GRADE score.Conclusion: The findings of our meta-analysis suggest that proadrenomedullin is elevated in neonates with sepsis. However, future prospective cohort studies need to be conducted in order to assess its diagnostic accuracy. What is Known: • Proadrenomedullin has been found increased in adult patients with infectious diseases such as community acquired pneumonia. • Proadrenomedullin plays a major role in the pathophysiology of sepsis in adults. What is New: • Proadrenomedullin is increased in neonates with sepsis. • Future cohort studies need to be conducted in order to elucidate the value of proadrenomedullin in a safer way.

MR-Proadrenomedullin as biomarker of renal damage in urinary tract infection in children

Background

Midregional-proadrenomedullin (MR-proADM) is a useful prognostic peptide in severe infectious pathologies in the adult population. However, there are no studies that analyze its utility in febrile urinary tract infection (fUTI) in children. An accurate biomarker would provide an early detection of patients with kidney damage, avoiding other invasive tests like renal scintigraphy scans. Our objective is to study the usefulness of MR-proADM as a biomarker of acute and chronic renal parenchymal damage in fUTI within the pediatric population.

Methods

A prospective cohort study was conducted in pediatric patients with fUTI between January 2015 and December 2018. Plasma and urine MR-proADM levels were measured at admission in addition to other laboratory parameters. After confirmation of fUTI, renal scintigraphy scans were performed during the acute and follow-up stages. A descriptive study has been carried out and sensitivity, specificity and ROC curves for MR-proADM, C-reactive protein, and procalcitonin were calculated.

Results

62 pediatric patients (34 female) were enrolled. Scintigraphy showed acute pyelonephritis in 35 patients (56.5%). Of those patients, the median of plasmatic MR-proADM (P-MR-proADM) showed no differences compared to patients without pyelonephritis. 7 patients (11.3%) developed renal scars (RS). Their median P-MR-proADM levels were 1.07 nmol/L (IQR 0.66–1.59), while in patients without RS were 0.48 nmol/L (0.43–0.63) (p < 0.01). The AUC in this case was 0.92 (95% CI 0.77–0.99). We established an optimal cut-off point at 0.66 nmol/L with sensitivity 83.3% and specificity 81.8%.

Conclusion

MR-ProADM has demonstrated a poor ability to diagnose pyelonephritis in pediatric patients with fUTI. However, P-MR-proADM proved to be a very reliable biomarker for RS prediction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02765-2.

The Role of Pro-Adrenomedullin as a Marker of Severe Bacterial Infection in Children: A Review

Sepsis is still related to high mortality and hospitalization rates in the paediatric population despite medical progress. Prompt recognition of sepsis and consequent initiation of an appropriate treatment are essential elements in securing a positive outcome in adults and children. In such scenario, various biomarkers have been studied to support the clinician in the diagnosis of severe infections, in the identification of patients at risk of progression towards sepsis as well as in the evaluation of the response to treatment. In children, the performance of C-reactive protein and procalcitonin has been largely investigated, whereas data on newer biomarkers of sepsis are scant. The aim of the present review is to summarise the available data on the use of pro-adrenomedullin in the paediatric age.

Assessment of proadrenomedullin as diagnostic or prognostic biomarker of acute appendicitis in children with acute abdominal pain

BACKGROUND

Acute appendicitis (AA) is one of the most frequent surgical pathologies in pediatrics.

OBJECTIVES

To investigate the utility of proadrenomedullin (pro-ADM) for the diagnosis of AA.

METHODS

Prospective, analytical, observational, and multicenter study conducted in 6 pediatric emergency departments. Children up to 18 years of age with suspected AA were included. Clinical, epidemiological, and analytical data were collected.

RESULTS

We studied 285 children with an average age of 9.5 years (95% confidence interval [CI], 9.1-9.9). AA was diagnosed in 103 children (36.1%), with complications in 10 of them (9.7%). The mean concentration of pro-ADM (nmol/L) was higher in children with AA (0.51 nmol/L, SD 0.16) than in children with acute abdominal pain (AAP) of another etiology (0.44 nmol/L, SD 0.14; p < 0.001). This difference was greater in complicated cases compared with uncomplicated AA (0.64 nmol/L, SD 0.17 and 0.50 nmol/L, SD 0.15, respectively; p = 0.005). The areas under the receiver-operating characteristic curves were 0.66 (95% CI, 0.59-0.72) for pro-ADM, 0.70 (95% CI, 0.63-0.76) for C-reactive protein (CRP), 0.84 (95% CI, 0.79-0.89) for neutrophils, and 0.84 (95% CI, 0.79-0.89) for total leukocytes. The most reliable combination to rule out AA was CRP ≤1.25 mg/dL and pro-ADM ≤0.35 nmol/L with a sensitivity of 96% and a negative predictive value of 93%.

CONCLUSION

Children with AA presented higher pro-ADM values than children with AAP of other etiologies, especially in cases of complicated AA. The combination of low values of pro-ADM and CRP can help to select children with low risk of AA.

Mid-Regional Pro-Adrenomedullin (MR-proADM) as a Biomarker for Sepsis and Septic Shock: Narrative Review

Early identification and diagnosis of sepsis and septic shock is vitally important; despite appropriate management, mortality and morbidity rates remain high. For this reason, many biomarkers and screening systems have been investigated in accordance with the precision medicine concept. A narrative review was conducted to assess the role of mid-regional pro-adrenomedullin (MR-proADM) as a biomarker for sepsis and septic shock. Relevant studies were collected via an electronic PubMed, Web of Science, and The Cochrane Library search. The review focused on both diagnosis and prognosis in patients with sepsis and septic shock and specifically in subpopulations of patients with sepsis and septic shock with burns or malignant tumors. No exclusion criteria regarding age, sex, intensive care unit admission, follow-up duration, or co morbidities were used so as to maximize sensitivity and due to lack of randomized controlled trials, opinion paper and reviews were also included in this review. A total of 22 studies, one opinion paper, and one review paper were investigated. MR-proADM levels were found to be useful in assessing patients’ initial evolution and become even more useful during follow-up with increased area under curve values in the mortality prognosis by exceeding values of 0.8 in the data shown in several studies. These results also improve along with other biomarkers or severity scores and especially correlate with the organ failure degree. The results of this study indicate that MR-proADM is a good biomarker for the diagnosis and prognosis of sepsis and septic shock patients as well as for organ failure. Although several publications have discussed its role as a biomarker for pneumonia, its value as a biomarker for sepsis and septic shock should now be assessed in randomized controlled trials and more collaborative prospective studies with larger patient samples.

Adrenomedullin and endothelin-1 are associated with myocardial injury and death in septic shock patients

Background

Adrenomedullin and endothelin-1 are hormones with opposing effects on the cardiovascular system. Adrenomedullin acts as a vasodilator and seems to be important for the initiation and continuation of the hyperdynamic circulatory response in sepsis. Endothelin-1 is a vasoconstrictor and has been linked to decreased cardiac performance. Few studies have studied the relationship between adrenomedullin and endothelin-1, and morbidity and mortality in septic shock patients. High-sensitivity troponin T (hsTNT) is normally used to diagnose acute cardiac injury but is also prognostic for outcome in intensive care. We investigated the relationship between mid-regional pro-adrenomedullin (MR-proADM), C-terminal pro-endothelin-1 (CT-proET-1), and myocardial injury, measured using transthoracic echocardiography and hsTNT in septic shock patients. We were also interested in the development of different biomarkers throughout the ICU stay, and how early measurements were related to mortality. Further, we assessed if a positive biomarker panel, consisting of MR-proADM, CT-proET-1, and hsTNT changed the odds for mortality.

Methods

A cohort of 53 consecutive patients with septic shock had their levels of MR-proADM, CT-proET-1, hsTNT, and left ventricular systolic functions prospectively measured over 7 days. The relationship between day 1 levels of MR-proADM/CT-proET-1 and myocardial injury was studied. We also investigated the relationship between biomarkers and early (7-day) and later (28-day) mortality. Likelihood ratios, and pretest and posttest odds for mortality were calculated.

Results

Levels of MR-proADM and CT-proET-1 were significantly higher among patients with myocardial injury and were correlated with left ventricular systolic dysfunction. MR-proADM and hsTNT were significantly higher among 7-day and 28-day non-survivors. CT-proET-1 was also significantly higher among 28-day but not 7-day non-survivors. A positive biomarker panel consisting of the three biomarkers increased the odds for mortality 13-fold to 20-fold.

Conclusions

MR-proADM and CT-proET-1 are associated with myocardial injury. A biomarker panel combining MR-proADM, CT-proET-1, and hsTNT increases the odds ratio for death, and may improve currently available scoring systems in critical care.

Mid-regional proadrenomedullin: An early marker of response in critically ill patients with severe community-acquired pneumonia?

BACKGROUND

Mid-regional proadrenomedullin (MR-proADM) is a novel biomarker with potential prognostic utility in patients with community-acquired pneumonia (CAP).

PURPOSE

To evaluate the value of MR-proADM levels at ICU admission for further severity stratification and outcome prediction, and its kinetics as an early predictor of response in severe CAP (SCAP).

MATERIALS AND METHODS

Prospective, single-center, cohort study of 19 SCAP patients admitted to the ICU within 12h after the first antibiotic dose.

RESULTS

At ICU admission median MR-proADM was 3.58nmol/l (IQR: 2.83-10.00). No significant association was found between its serum levels at admission and severity assessed by SAPS II (Spearman's correlation=0.24, p=0.31) or SOFA score (SOFA<10: <3.45nmol/l vs. SOFA≥10: 3.90nmol/l, p=0.74). Hospital and one-year mortality were 26% and 32%, respectively. No significant difference in median MR-proADM serum levels was found between survivors and non-survivors and its accuracy to predict hospital mortality was bad (aROC 0.53). After 48h of antibiotic therapy, MR-proADM decreased in all but 5 patients (median -20%; IQR -56% to +0.1%). Its kinetics measured by the percent change from baseline was a good predictor of clinical response (aROC 0.80). The best discrimination was achieved by classifying patients according to whether MR-proADM decreased or not within 48h. No decrease in MR-proADM serum levels significantly increased the chances of dying independently of general severity (SAPS II-adjusted OR 174; 95% CI 2-15,422; p=0.024).

CONCLUSIONS

In SCAP patients, a decrease in MR-proADM serum levels in the first 48h after ICU admission was a good predictor of clinical response and better outcome.

MR-proADM Predicts Exercise Capacity and Survival Superior to Other Biomarkers in PH

PURPOSE

Besides the established biomarker NT-proBNP, the new cardiovascular biomarkers MR-proANP, MR-proADM, Copeptin, and CT-proET-1 are promising to evaluate hemodynamics, exercise parameters, and prognosis in patients with pulmonary hypertension (PH).

METHODS

125 consecutive patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) were prospectively enrolled at five German PH centers. Blood samples were taken during right heart catheterization. The primary study endpoint was the correlation between biomarkers and hemodynamic and exercise parameters. As secondary endpoint, prediction of 1-year mortality was evaluated.

RESULTS

MR-proADM showed the strongest correlations with 6MWD and VO2peak, whereas NT-proBNP showed the strongest correlations with PVR, PAPm, and CI. In multivariate analysis, only MR-proADM was independently associated with exercise variables, whereas only NT-proBNP independently predicted hemodynamic parameters. All biomarkers were associated with 1-year survival, with MR-proADM showing the highest C index of 0.78. In multivariate analysis, MR-proADM predicted survival independent of age, 6-MWD, CI, RAP, and NT-proBNP. The cut-off of 1.08 nmol/l provided a sensitivity of 83 % and specificity of 66 %.

CONCLUSIONS

Different biomarkers reflect distinctive disease aspects in PH. NT-proBNP best predicts hemodynamic impairment while MR-proADM strongly correlates with exercise capacity. Additionally, MR-proADM represents a promising new marker to evaluate prognosis in patients with PAH and CTEPH. Multi-marker strategies should further be evaluated.

Pro-adrenomedullin, pro-endothelin-1, procalcitonin, C-reactive protein and mortality risk in critically ill children: a prospective study

Introduction

We tested the hypothesis that higher mid-regional pro-adrenomedullin (MR-proADM), carboxy-terminal pro-endothelin-1 (CT-proET-1), procalcitonin (PCT) and C-reactive protein (CRP) plasma concentrations would be associated with increased prediction of mortality risk scores.

Methods

Prospective observational study set in two pediatric intensive care units (PICUs). Two-hundred-thirty-eight patients were included. MR-proADM, CT-proET-1, PCT and CRP levels were compared between children with PRISM III and PIM 2 > p75 (Group A; n = 33) and the rest (Group B; n = 205).

Results

Median (range) MR-proADM levels were 1.39 nmol/L (0.52–12.67) in group A versus 0.54 (0.15–3.85) in group B (P < 0.001). CT-proET-1 levels were 172 pmol/L (27–500) versus 58 (4–447) (P < 0.001). PCT levels were 7.77 ng/mL (0.34–552.00) versus 0.28 (0.02–107.00) (P < 0.001). CRP levels were 6.23 mg/dL (0.08-28.25) versus 1.30 mg/dL (0.00-42.09) (P = 0.210). The area under the ROC curve (AUC) for the differentiation of group A and B was 0.87 (95% CI:0.81–0.821) for MR-proADM, 0.86 (95% CI:0.79–0.92) for CT-proET-1 and 0.84 (95% CI:0.74–0.94) for PCT. A MR-proADM > 0.79 nmol/L had 93% sensitivity and 76% specificity to differentiate groups, whereas a CT-proET-1 > 123 pmol/L had 77% sensitivity and 84% specificity, and a PCT concentration > 2.05 ng/mL had 80% sensitivity and specificity.

Conclusions

In critically ill children, high levels of MR-proADM, CT-proET-1 and PCT were associated with increased prediction of mortality risk scores. MR-proADM, CT-proET-1 and PCT concentrations higher than 0.80 nmol/L, 123 pmol/L and 2 ng/mL, respectively, could be used by clinicians to identify critically ill children at higher prediction of risk death scores.

Copeptin and MR-proADM in umbilical cord plasma reflect perinatal stress in neonates born to mothers with diabetes and MR-proANP reflects maternal diabetes

AIM

To examine concentrations of three cardiovascular propeptides in umbilical cord plasma of neonates born to mothers with Type 1, Type 2 and gestational diabetes. Measurement of cardiovascular markers in umbilical cord plasma may potentially help identify neonates at risk of postnatal complications. Neonates born to mothers with diabetes have an increased risk of neonatal morbidity and mortality, and measurement of these new biomarkers may potentially help identify neonates at risk of these complications.

SUBJECTS & METHODS

Copeptin, midregional proadrenomedullin (MR-proADM) and mid-regional pro-A-type natriuretic peptide (MR-proANP) were measured in cord plasma of neonates (n = 63) born to mothers with the three types of diabetes. Associations with maternal glycemic control, mode of delivery and neonatal metabolic acidosis were examined.

RESULTS

Umbilical cord plasma copeptin concentrations were lowest in neonates after elective cesarean sections (6.1 pmol/l; interquartile range [IQR]: 4.5-9.1) compared with emergency cesarean sections (156 pmol/l; IQR: 9.6-311; p = 0.019) and vaginal delivery (831 pmol/l; IQR: 107-2407; p < 0.0001). MR-proADM was also affected by mode of delivery; however, this seemed more likely to be caused by an inverse association with the acid-base balance. In this population, only MR-proANP plasma concentrations were related to type of diabetes. Neonates born to mothers with Type 1 diabetes had higher concentrations (median 260 pmol/l; IQR: 222-318) compared with Type 2 diabetes (175 pmol/l; IQR: 169-200; p = 0.003) and gestational diabetes (200 pmol/l; IQR: 149-276; p = 0.009).

CONCLUSION

Umbilical cord plasma copeptin and MR-proADM concentrations primarily reflect perinatal stress associated with mode of delivery and the degree of fetal acidosis, whereas MR-proANP concentrations are higher in neonates born to mothers with Type 1 diabetes.

Proadrenomedullin as a prognostic marker in neonatal sepsis

BACKGROUND

Proadrenomedullin (pro-ADM) for the diagnosis of proven and clinical sepsis in a newborn cohort including preterm newborns has not been investigated. We aimed to investigate the value of pro-ADM as a new marker by comparing it with conventional markers in neonatal sepsis (NS).

METHODS

Participants were stratified into three groups; proven sepsis (Group 1a), clinical sepsis (Group 1b), and the control group (Group 2), which consisted of newborns of matched gestational age and birth weight. Sequential measurements of white blood cell count, C-reactive protein (CRP), interleukin-6 (IL-6), and pro-ADM were compared.

RESULTS

A total of 76 patients with NS (31 with proven sepsis and 45 with clinical sepsis) and 52 healthy controls were enrolled. Mean baseline serum levels of CRP, IL-6, and pro-ADM were significantly higher in both Group 1a and Group 1b as compared with healthy controls (P < 0.001 for both). Although mean baseline CRP and IL-6 levels were similar between groups, mean baseline pro-ADM level was higher in the proven sepsis group than in the clinical sepsis group (P < 0.001).

CONCLUSION

The use of pro-ADM in combination with other acute-phase reactants such as CRP and IL-6 for the diagnosis and follow-up of patients with NS has high sensitivity and specificity.

Adrenomedullin and pregnancy: perspectives from animal models to humans

A healthy pregnancy requires strict coordination of genetic, physiologic and environmental factors. The relatively common incidence of infertility and pregnancy complications has resulted in increased interest in understanding the mechanisms that underlie normal versus abnormal pregnancy. The peptide hormone adrenomedullin (AM) has recently been the focus of some exciting breakthroughs in the pregnancy field. Supported by mechanistic studies in genetic animal models, there continues to be a growing body of evidence demonstrating the importance of AM protein levels in a variety of human pregnancy complications. With more extensive mechanistic studies and improved consistency in clinical measurements of AM, there is great potential for the development of AM as a clinically-relevant biomarker in pregnancy and pregnancy complications.

Plasma midregional proadrenomedullin in newborn infants: impact of prematurity and perinatal infection

INTRODUCTION

Adrenomedullin (ADM) is one of the strongest endogenous vasodilating hormones. Its stable by-product midregional-proADM (MR-proADM) is an established indicator of systemic infection and cardiovascular compromise in adult patients.

METHODS

A prospective cross-sectional study was performed to investigate the perinatal factors affecting MR-proADM plasma concentrations in 328 newborn infants with a gestational age (GA) between 24 and 41 wk.

RESULTS

Blood samples were obtained in 270 infants from umbilical veins (with additional 108 paired samples from umbilical arteries), and at 2-3 d of life in 183 infants. Paired venous and arterial umbilical cord MR-proADM concentrations were closely related (Spearman's rank order correlation coefficient (R(s)) = 0.825, P < 0.001). MR-proADM concentrations at birth and at 2-3 d were inversely related to GA (R(s) = -0.403 and R(s) = -0.541, respectively) and birth weight (BW; R(s) = -0.421 and R(s) = -0.530, respectively; all P < 0.001). On stepwise regression analysis, clinical chorioamnionitis and umbilical arterial blood base excess retained a significant impact on MR-proADM cord venous blood concentrations. At 2-3 d of life, histologic chorioamnionitis and GA at delivery were significantly associated with MR-proADM levels.

DISCUSSION

As compared with adults, MR-proADM concentrations are elevated in neonates, especially those born very preterm. Immaturity and infection, which both feature low systemic vascular resistance, are related to increased MR-proADM concentrations.

Umbilical blood biomarkers for predicting early-onset neonatal sepsis

BACKGROUND

Since the 1990s, finding the most efficient markers or combinations as predictors of early-onset neonatal sepsis has been the hot topic of studies. But there is no review of such biomarkers detected in umbilical blood at birth. By comparing clinical values of common inflammatory markers detected in cord blood shortly after birth, in this study we tried to find the most performing one or the most efficient combination that might be potentially used in birth room, as the earliest predictor of early-onset neonatal sepsis.

DATA SOURCES

We searched PubMed and Elsevier's Web of Science for studies evaluating cord blood inflammatory markers in relation to early-onset neonatal sepsis.

RESULTS

Among C-reactive protein (CRP), procalcitonin (PCT), IL-6, IL-8, TNF-α and IL-1β, none of them could be used individually to establish or exclude the diagnosis of early-onset neonatal sepsis, but PCT, IL-6 and IL-8 have great superiority to CRP, TNF-α and IL-1β. When combined with other hematological markers and clinical observation, the clinical reliability of PCT, IL-6 and IL-8 could be improved. Prolonging the sample collection time window seems to have a positive effect on the clinical utility of IL-6 and IL-8.

CONCLUSIONS

More researches focusing on the combination of different umbilical cord biomarkers in different clinical settings are needed to achieve clearer conclusions. Multi-center, large-sized analysis, especially examining groups of cytokines, is also expected.

Precursors of adrenomedullin, endothelin and atrial natriuretic peptide as diagnostic markers of neonatal infection

AIM

To evaluate the serum levels of three precursors of vasoactive peptide as diagnostic markers for neonatal infections.

METHODS

Overall, 356 neonates (160 without infection, 114 with mild infections and 82 with severe infections) were enrolled in this study. Their serum levels of mid-regional pro-adrenomedullin (MR-pro-ADM), C-terminal pro-endothelin-1 (CT-pro-ET-1) and mid-regional pro-atrial natriuretic peptide (MR-pro-ANP) were measured by immunoassay, and receiver operating curve analysis was performed for each biomarker to evaluate their diagnostic values for neonatal infection.

RESULTS

The serum levels of MR-pro-ADM (2.079 ± 1.195 nM), CT-pro-ET-1 (109.4 ± 62.9 pM) and MR-pro-ANP (1221.4 ± 725.0 pM) in the severe infection group were significantly higher than those in the mild infection group (1.025 ± 0.421 nM, 86.7 ± 51.8 pM, and 687.6 ± 575.7 pM, respectively) and in the non-infection group (0.853 ± 0.488 nM, 51.3 ± 40.6 pM, and 943.3 ± 847.3 pM, respectively) (p < 0.01-0.001). Their areas under the curve were 0.72, 0.76 and 0.61, respectively. Among them, CT-pro-ET-1 had the highest sensitivity (82.65%), whereas MR-pro-ADM had the highest specificity (86.25%).

CONCLUSIONS

MR-pro-ADM, CT-pro-ET-1 and MR-pro-ANP may serve as useful laboratory markers to indicate bacterial infection in neonates.

Plasma pro-endothelin-1 and respiratory distress in newborn infants

Plasma concentrations of the stable endothelin-1 precursor, C-terminal portion of the endothelin-1 precursor, determined prospectively in 293 newborn infants (gestational age, 24-41 weeks) at birth and on day 3 of life were unrelated to gestational age at birth, but strongly associated with respiratory distress when measured on day 3 of life.

Plasma C-terminal pro-endothelin-1 and the natriuretic pro-peptides NT-proBNP and MR-proANP in very preterm infants with patent ductus arteriosus

BACKGROUND

In very preterm infants, clinical decision-making, such as closing a patent ductus arteriosus (PDA), may be aided by measuring circulating natriuretic and endothelial pro-peptides.

OBJECTIVES

To investigate the association between perinatal characteristics, PDA echocardiography and plasma concentrations of stable pro-peptides of B-type natriuretic peptide (NT-proBNP), atrial natriuretic peptide (MR-proANP) and endothelin-1 (CT-proET-1).

METHODS

A prospective, cross-sectional, single-center study was performed in 66 infants who were less than 32 weeks of gestational age. Pro-peptide concentrations were determined at birth and at day 2-3 of life.

RESULTS

Plasma concentrations of all 3 pro-peptides increased on average 2- to 5-fold from birth to day 2-3 of life. NT-proBNP and MR-proANP were closely related at birth and at day 2-3 (Rs 0.902 and 0.897, respectively, p < 0.001), whereas CT-proET-1 was related to NT-proBNP and MR-proANP at birth (Rs 0.478 and 0.460, respectively, p < 0.001) but not at day 2-3. Birth weight was negatively related to all 3 pro-peptides at birth (p < 0.01); however, preeclampsia and compromised placental perfusion were associated with elevated NT-proBNP and MR-proANP concentrations at birth. At day 2-3, MR-proANP and NT-proBNP correlated significantly with the ductal diameter (Rs 0.416 and 0.415, respectively, both p = 0.011), whereas CT-proET-1 correlated with the left atrium/aorta ratio (Rs 0.506, p = 0.027). CT-proET-1 was elevated in infants with treated compared to untreated PDA [median (5-95% range) 388 (272-723) vs. 303 (152-422) pmol/l, p = 0.011], but not NT-proBNP or MR-proANP.

CONCLUSION

CT-proET-1 is a promising predictor in determining the need for PDA intervention.

Emerging biomarkers for the diagnosis of severe neonatal infections applicable to low resource settings

More than 500 000 children die each year in low resource settings due to serious neonatal infections. Better diagnostics that can be utilized in these settings to identify infected infants have the potential to significantly reduce neonatal deaths and the associated morbidity. A systematic review was performed and identified more than 250 potential new biomarkers for the diagnosis of serious neonatal infections. Eight of these biomarkers were both high-performance and high-abundance (antithrombin, inter-α inhibitor proteins, interferon-γ inducible protein-10, interleukin-1 receptor antagonist, LPS binding protein, mannose binding lectin, serum amyloid A, resistin, visfatin), and are promising for the diagnosis of serious neonatal infections in low resource settings. Future clinical trials comparing these biomarkers with more traditional biomarkers seem warranted.

Procalcitonin measurement at 24 hours of age may be helpful in the prompt diagnosis of early-onset neonatal sepsis

BACKGROUND

The clinical signs of early-onset neonatal sepsis (EONS) are nonspecific and indistinguishable from those of noninfectious disorders. The early diagnosis of EONS is difficult, but is essential to improve outcomes. The aim of this study was to determine the diagnostic value of procalcitonin (PCT) at birth and at 24h of age in the prompt diagnosis of EONS.

METHODS

The patient group consisted of neonates with a Töllner score of ≥ 10 or a Töllner score of 5-10 but with the presence of prolonged rupture of the membranes (> 18 h) or chorioamnionitis or maternal fever (n=171). The control group (n=89) comprised neonates admitted to the neonatal intensive care unit for different disease entities. Procalcitonin levels at birth (first) and at 24h of age (second) were measured for each neonate in both of the study groups.

RESULTS

There was no difference between the two groups in terms of gender, birth weight, or gestational age. The mean (min-max) first PCT level was 0.48 (0.07-3.48)ng/ml in the controls and 0.51 (0.09-28.6)ng/ml in patients. The mean (min-max) second PCT level was 1.72 (0.21-18.23)ng/ml in the controls and 16.17 (0.17-100)ng/ml in patients. There was no statistically significant difference in PCT levels between the patient and control groups at birth. However, at 24h of age, PCT levels were significantly higher in the patient group than in the control group (p<0.001). Serum PCT levels in controls at 24h of age were slightly increased compared to levels at birth, but as a normal reaction. PCT thresholds for the diagnosis of sepsis were 0.59 ng/ml at birth (sensitivity 48.7%, specificity 68.6%) and 5.38 ng/ml at 24h of life (sensitivity 83.3%, specificity 88.6%).

CONCLUSIONS

In EONS, PCT measurements at birth may initially be normal; a serial PCT measurement at 24h of age may be more helpful for an early diagnosis. During the first 24h of life PCT is a more sensitive marker of infection than C-reactive protein. Further studies are needed to confirm our findings.