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

Procalcitonin Guided Antibiotic Stewardship

Despite infection and sepsis being a major public health challenge, early detection and timely management are often hindered by several factors. These includes the similarity of clinical presentations between infectious and non-infectious conditisons, as well as limitations of current diagnostic methods such as lengthy turnaround times and low sensitivity. Consequently, there is increasing interest in identifying biomarkers that can quickly and accurately differentiate bacterial sepsis from other inflammatory processes, whether infectious or non-infectious. Procalcitonin has emerged as one of the most extensively studied and utilized biomarkers in managing infection and sepsis, especially within the framework of antibiotic stewardship. This review aims to examine the role of Procalcitonin in guiding antibiotic stewardship. It explores the production and release of procalcitonin and its relevance in the context of infection and sepsis. The discussion focus on the clinical and economic impacts of using procalcitonin to guide the initiation and discontinuation of antibiotics in managing these conditions.

Biomarkers of Neonatal Sepsis: Where We Are and Where We Are Going

Neonatal sepsis is a bacterial bloodstream infection leading to severe clinical manifestations frequently associated with death or irreversible long-term deficits. Antibiotics are the drug of choice to treat sepsis, regardless of age. In neonates, the lack of reliable criteria for a definite diagnosis and the supposition that an early antibiotic administration could reduce sepsis development in children at risk have led to a relevant antibiotic overuse for both prevention and therapy. The availability of biomarkers of neonatal sepsis that could alert the physician to an early diagnosis of neonatal sepsis could improve the short and long-term outcomes of true sepsis cases and reduce the indiscriminate and deleterious use of preventive antibiotics. The main aim of this narrative review is to summarize the main results in this regard and to detail the accuracy of currently used biomarkers for the early diagnosis of neonatal sepsis. Literature analysis showed that, despite intense research, the diagnosis of neonatal sepsis and the conduct of antibiotic therapy cannot be at present decided on the basis of a single biomarker. Given the importance of the problem and the need to reduce the abuse of antibiotics, further studies are urgently required. However, instead of looking for new biomarkers, it seems easier and more productive to test combinations of two or more of the presently available biomarkers. Moreover, studies based on omics technologies should be strongly boosted. However, while waiting for new information, the use of the clinical scores prepared by some scientific institutions could be suggested. Based on maternal risk factors and infant clinical indicators, sepsis risk can be calculated, and a significant reduction in antibiotic consumption can be obtained.

Bioinformatic Analysis and Machine Learning Methods in Neonatal Sepsis: Identification of Biomarkers and Immune Infiltration

The disease neonatal sepsis (NS) poses a serious threat to life, and its pathogenesis remains unclear. Using the Gene Expression Omnibus (GEO) database, differentially expressed genes (DEGs) were identified and functional enrichment analyses were conducted. Three machine learning algorithms containing the least absolute shrinkage and selection operator (LASSO), support vector machine recursive feature elimination (SVM-RFE), and random forest (RF) were applied to identify the optimal feature genes (OFGs). This study conducted CIBERSORT to present the abundance of immune infiltrates between septic and control neonates and assessed the relationship between OFGs and immune cells. In total, 44 DEGs were discovered between the septic and control newborns. Throughout the enrichment analysis, DEGs were primarily related to inflammatory signaling pathways and immune responses. The OFGs derived from machine learning algorithms were intersected to yield four biomarkers, namely Hexokinase 3 (HK3), Cystatin 7 (CST7), Resistin (RETN), and Glycogenin 1 (GYG1). The potential biomarkers were validated in other datasets and LPS-stimulated HEUVCs. Septic infants showed a higher proportion of neutrophils (p < 0.001), M0 macrophages (p < 0.001), and regulatory T cells (p = 0.004). HK3, CST7, RETN, and GYG1 showed significant correlations with immune cells. Overall, the biomarkers offered promising insights into the molecular mechanisms of immune regulation for the prediction and treatment of NS.

Prospective multicentre study of host response signatures in neonatal sepsis in Sub Saharan Africa

Few biomarkers for sepsis diagnosis are commonly used in neonatal sepsis. While the role of host response is increasingly recognized in sepsis pathogenesis and prognosis, there is a need for evaluating new biomarkers targeting host response in regions where sepsis burden is high and medico-economic resources are scarce. The objective of the study is to evaluate diagnostic and prognostic accuracy of biomarkers of neonatal sepsis in Sub Saharan Africa. This prospective multicentre study included newborn infants delivered in the Abomey-Calavi region in South Benin and their follow-up from birth to 3 months of age. Accuracy of transcriptional (CD74, CX3CR1), proteic (PCT, IL-6, IL-10, IP-10) biomarkers and clinical characteristics to diagnose and prognose neonatal sepsis were measured. At delivery, cord blood from all consecutive newborns were sampled and analysed, and infants were followed for a 12 weeks' period. Five hundred and eighty-one newborns were enrolled. One hundred and seventy-two newborns developed neonatal sepsis (29.6%) and death occurred in forty-nine infants (8.4%). Although PCT, IL-6 and IP-10 levels were independently associated with sepsis diagnosis, diagnostic accuracy of clinical variables combinations was similar to combinations with biomarkers and superior to biomarkers alone. Nonetheless, CD74, being the only biomarkers independently associated with mortality, showed elevated prognosis accuracy (AUC > 0.9) either alone or in combination with other biomarkers (eg. CD74/IP-10) or clinical criterion (eg. Apgar 1, birth weight). These results suggest that cord blood PCT had a low accuracy for diagnosing early onset neonatal sepsis in Sub Saharan African neonates, while association of clinical criterion showed to be more accurate than any biomarkers taken independently. At birth, CD74, either associated with IP-10 or clinical criterion, had the best accuracy in prognosing sepsis mortality.Trial registration Clinicaltrial.gov registration number: NCT03780712. Registered 19 December 2018. Retrospectively registered.

Procalcitonin levels in preterm newborns: Reference ranges during the first three days of life

Background

Sepsis is one of the most important causes of morbidity and mortality in the neonatal period, especially in preterms. Diagnosis is difficult because of specific signs and symptoms. The diagnostic gold standard is blood culture, but its sensibility is low. Much effort has been made to identify early, sensitive, and specific diagnostic markers; among these markers particular attention was paid to procalcitonin. However, reference ranges of serum procalcitonin (PCT) shortly after birth have not been sufficiently studied in healthy preterms, and literature is still contradictory.

Objectives

The aim of the study is to define PCT age-specific reference ranges in the first 72 h of life in uninfected VLBW preterms.

Methods

Serum levels of PCT were assessed for each newborn at birth and every 24 h until the 3rd day of life. The eligible patients were classified into two groups according to their sepsis status.

Results

Approximately 343 patients were enrolled; 28 were septic and 315 non-septic. In non-septic infants, 1,015 determinations of PCT values were performed. Our data showed a trend in average value of PCT to increase after birth up to a peak between 24 and 48 h of life and, subsequently, to fall. The average peak value was 15.12 ng/ml achieved at nearly 36 h of life.

Conclusion

Our study shows a PCT nomogram of healthy preterms, which is different from the one of term newborns. Data agree with what is reported in literature on the reference ranges and trends of PCT in non-septic preterms shortly after birth.

Diagnostic and Prognostic Value of Monocyte Distribution Width in Sepsis

Monocyte distribution width (MDW) is a blood monocyte morphological parameter that can be easily detected by an automated hemocyte analyzer and can provide clinicians with important information about cell volume variability in peripheral blood monocyte populations. The United States' Food and Drug Administration and Conformite Europeenne have both been cleared for their clinical application in the detection of sepsis and developing sepsis in adult patients in the emergency department (ED). Recently, MDW has been found to have an early diagnosis and predictive value for sepsis in neonates and COVID-19 patients. Here, we summarize the findings of the studies investigating the clinical application of MDW in sepsis. Under different stimuli, especially in infectious diseases, the activation of innate immunity is the host's first defense mechanism, and the change in monocyte volume is considered an early indicator reflecting the state of activation of innate immunity. Pivotal study data from a large multicenter patient cohort showed that abnormal MDW at presentation increases the odds of sepsis, considering the combination of MDW and White Blood Cell Count (WBC) as part of a standard sepsis assessment protocol for ED, which may increase the sensitivity and specificity of sepsis diagnosis. Meanwhile, MDW shares a diagnostic performance comparable to that of conventional biomarkers (C-reactive protein and procalcitonin) in sepsis. In addition, some evidence suggests that increased MDW, both in adults and neonates, may be associated with unfavorable short- and long-term outcomes, which indicates its prognostic value in sepsis. Taken together, MDW is a parameter of increased morphological variability of monocytes in response to infection, and numerous studies have shown that MDW could be used as a valuable diagnostic and prognostic index in patients with sepsis or suspected sepsis.

A Novel Algorithm With Paired Predictive Indexes to Stratify the Risk Levels of Neonates With Invasive Bacterial Infections: A Multicenter Cohort Study

BACKGROUND

Our aim was to develop a predictive model comprising clinical and laboratory parameters for early identification of full-term neonates with different risks of invasive bacterial infections (IBIs).

METHODS

We conducted a retrospective study including 1053 neonates presenting in 9 tertiary hospitals in China from January 2010 to August 2019. An algorithm with paired predictive indexes (PPIs) for risk stratification of neonatal IBIs was developed. Predictive performance was validated using k-fold cross-validation.

RESULTS

Overall, 166 neonates were diagnosed with IBIs (15.8%). White blood cell count, C-reactive protein level, procalcitonin level, neutrophil percentage, age at admission, neurologic signs, and ill-appearances showed independent associations with IBIs from stepwise regression analysis and combined into 23 PPIs. Using 10-fold cross-validation, a combination of 7 PPIs with the highest predictive performance was picked out to construct an algorithm. Finally, 58.1% (612/1053) patients were classified as low-risk cases. The sensitivity and negative predictive value of the algorithm were 95.3% (95% confidence interval: 91.7-98.3) and 98.7% (95% confidence interval: 97.8-99.6), respectively. An online calculator based on this algorithm was developed for clinical use.

CONCLUSIONS

The new algorithm constructed for this study was a valuable tool to screen neonates with suspected infection. It stratified risk levels of IBIs and had an excellent predictive performance.

Diagnosis of Neonatal Sepsis: The Role of Inflammatory Markers

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

Diagnosis of neonatal sepsis: the past, present and future

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

The Role and Validity of Diagnostic Biomarkers in Late-Onset Neonatal Sepsis

Sepsis remains a leading cause of mortality in the neonatal population, and currently, there is still no consensus on an accurate biomarker that can aid prompt diagnosis. This review focuses on studies investigating biomarkers for late-onset neonatal sepsis specifically. We discuss the current evidence for traditionally used biomarkers and present recent developments on more novel markers.  Suitable articles were selected from PubMed, Embase, Medline, Cochrane Handbook of Systematic Reviews, and ScienceDirect. Inclusion criteria were studies published from 2010 to 2020. Exclusion criteria were animal model-based studies. Keywords in search strategy were late-onset neonatal sepsis + biomarkers + diagnosis.  Evidence is growing increasingly weak for commonly studied biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT). Levels of markers such as Serum Amyloid A and Neutrophil CD64 increase more rapidly post-onset of infection compared to CRP. Moreover, this review found that the more novel biomarkers discussed such as presepsin and endocan may show superior and more promising potential as diagnostic markers. However, larger studies over multicenters are deemed essential to ascertain the ideal biomarker.

Neonatal sepsis at point of care

Sepsis, which includes infection followed by inflammation, is one of the leading causes of death among neonates worldwide. The major attribute of this disease process is dysregulated host response to infection leading to organ dysfunction and potentially death. A comprehensive understanding of the host response as well as the pathogen itself are important factors contributing to outcome. Early diagnosis is paramount, as it leads to accurate assessment and improved clinical management. Accordingly, a number of diagnostic platforms have been introduced to assess the presence of blood stream pathogens in septic neonates. Unfortunately, current point-of-care (POC) methods rely on a single parameter/biomarker and thus lack a comprehensive evaluation. The emerging field of biosensing has, however, resulted in the development of a wide range of analytical devices that may be useful at POC. This review discusses currently available methods to screen the inflammatory process in neonatal sepsis. We describe POC sensor-based methods for single platform multi-analyte detection and highlight the latest advances in this evolving technology. Finally, we critically evaluate the applicability of these POC devices clinically for early diagnosis of sepsis in neonates.

A sequential guide to identify neonates with low bacterial meningitis risk: a multicenter study

Objective

To derive and validate a predictive algorithm integrating clinical and laboratory parameters to stratify a full‐term neonate's risk level of having bacterial meningitis (BM).

Methods

A multicentered dataset was categorized into derivation (689 full‐term neonates aged ≤28 days with a lumbar puncture [LP]) and external validation (383 neonates) datasets. A sequential algorithm with risk stratification for neonatal BM was constructed.

Results

In the derivation dataset, 102 neonates had BM (14.8%). Using stepwise regression analysis, fever, infection source absence, neurological manifestation, C‐reactive protein (CRP), and procalcitonin were selected as optimal predictive sets for neonatal BM and introduced to a sequential algorithm. Based on the algorithm, 96.1% of BM cases (98 of 102) were identified, and 50.7% of the neonates (349 of 689) were classified as low risk. The algorithm’s sensitivity and negative predictive value (NPV) in identifying neonates at low risk of BM were 96.2% (95% CI 91.7%–98.9%) and 98.9% (95% CI 97.6%–99.6%), respectively. In the validation dataset, sensitivity and NPV were 95.9% (95% CI 91.0%–100%) and 98.8% (95% CI 97.7%–100%).

Interpretation

The sequential algorithm can risk stratify neonates for BM with excellent predictive performance and prove helpful to clinicians in LP‐related decision‐making.

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.

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

Background

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

Methods

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

Results

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

Conclusions

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

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.

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.

Blood Procalcitonin Levels and Duration of Antibiotics in Neonatal Sepsis

OBJECTIVE

To determine the time to normalization of procalcitonin (PCT) levels and duration of antibiotics in neonatal sepsis.

METHODS

A prospective observational study design was used. The participants included were neonates with sepsis. The primary outcome measure was time to normalization of PCT levels and duration of antibiotics following clinical resolution.

RESULTS

Time to normalization of PCT levels was 9.6 ± 4.2 days in neonates with septic shock, 6.2 ± 2.5 days in neonates without shock, 9.6 ± 3.1 days in neonates with culture-positive sepsis and 6.4 ± 3.1 days in neonates with culture-negative sepsis. Time to normalization of PCT levels according to the stage of systemic inflammatory response syndrome was 5.8 ± 2.8 days in neonates with sepsis, 6.1 ± 3.1 days in those with sepsis syndrome, 6.3 ± 3.3 days in those with early septic shock and 9.4 ± 3.6 days in those with multiorgan dysfunction syndrome. There was no morbidity and mortality in any neonate in the 4-week follow-up.

CONCLUSION

The duration of antibiotics can be determined by observing the time to normalization of PCT following clinical resolution of sepsis.

Procalcitonin versus C-reactive protein: review of kinetics and performance for diagnosis of neonatal sepsis

Procalcitonin (PCT) and C-reactive protein (CRP) are commonly used biomarkers, but their diagnostic advantage for neonatal early-onset (EOS) or late-onset (LOS) sepsis is controversial. In a comprehensive literature review we found significant heterogeneity between studies in sample timing, cut-off values, consideration of blood culture results for sepsis classification, and definition of EOS versus LOS. We identified 39 studies directly comparing PCT with CRP, but only four in very low birth weight (VLBW) neonates. The mean sensitivity for EOS, LOS, and EOS + LOS was 73.6%, 88.9%, and 76.5% for PCT, compared to 65.6%, 77.4%, and 66.4% for CRP, respectively. Mean specificity of PCT and CRP was 82.8% versus 82.7% for EOS, 75.6% versus 81.7% for LOS, and 80.4% versus 91.3% for EOS + LOS. More studies directly comparing both biomarkers for EOS and LOS, especially in extremely and very-low-birth-weight infants, are needed to determine their clinical value for guidance of antibiotic therapy in neonatal sepsis.

How to use… Procalcitonin

Diagnosing bacterial infection in the unwell or febrile child is a common challenge faced by all paediatricians. Despite the advent of novel molecular techniques, there is ongoing need for diagnostic assays with adequate performance and turnaround time to facilitate safe clinical decision-making when bacterial sepsis is suspected, such as whether to commence empirical treatment with antibiotics. Procalcitonin is an established marker of infection that has a potential role in the diagnosis and exclusion of serious or invasive bacterial infection in neonates and children. Although enthusiastically adopted in many countries and institutions, national guidance in the UK does not yet support its routine use. This article reviews the relevant literature on the use of procalcitonin measurement in common paediatric clinical scenarios.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The cut-off levels of procalcitonin and C-reactive protein and the kinetics of mean platelet volume in preterm neonates with sepsis

Background

Sepsis is a leading cause of morbidity and mortality among newborns. C-reactive protein (CRP) and procalcitonin (PCT) have some limitations in the diagnosis of preterm neonatal sepsis. In this study, the cut-offs of PCT and CRP, and the efficacy of mean platelet volume (MPV) were investigated.

Methods

We identified key demographic details and compared laboratory values between preterm infants with early onset and late onset neonatal sepsis (EONS/LONS) retrospectively. Blood samples were collected within the first few hours of the onset of clinical sepsis (CRP 1, PCT 1, MPV 1) and were repeated after 24 h (CRP 2, PCT 2, MPV 2). The optimal cut-offs for CRP, PCT and MPV were determined using receiver operating characteristic (ROC) analysis. Furthermore, pairwise comparisons of ROC curves were made to evaluate the performances of these tests.

Results

In EONS, the cut-off of CRP 1 was 2.6 mg/L, the sensitivity, specificity, PPV and NPV were 80.6, 83.0, 67.5 and 90.7%, respectively (p < 0.001). At a PCT 1 cut-off of 1.1 ng/mL, the sensitivity, specificity, PPV and NPV were 78.6, 81.2, 64.7 and 89.6%, respectively (p < 0.001). The sensitivity, specificity, PPV, and NPV of the CRP 1 cut-off of 3.6 mg/L for LONS were 78.3, 87.4, 74.8, and 89.4%, respectively. At a PCT 1 cut-off of 5.2 ng/mL, the sensitivity, specificity, PPV and NPV were 58.5, 95.5, 86.1, and 82.9% respectively. For proven sepsis, the cut-off of CRP 1 was 7.0 mg/L with a 76.5% sensitivity, 98.2% specificity, 94.9% PPV and 90.5% NPV (p < 0.001). At a PCT 1 cut-off of 1.36 ng/mL, the sensitivity, specificity, PPV and NPV were 90.8, 83.4, 70.6 and 94.4%, respectively (p < 0.001). In each subgroup, other than EONS, the performances of CRP 1 and PCT 1 measurements were found to be statistically higher than MPV 1. CRP 2 cut-off levels of LONS group and proven sepsis group were found to be lower than the initial values.

Conclusions

Optimal cut-off levels of CRP 1 and PCT 1 may differ in preterm sepsis subgroups. The diagnostic performances of CRP 1 and PCT 1 didn’t differ however, they were more efficacious than MPV.

Procalcitonin and Neonatal Sepsis: Is This the Biomarker We Are Looking For?

Researchers estimate the incidence of early onset sepsis as 0.77-1/1,000 live births. It remains as one of the leading causes of neonatal deaths. Clinicians and researchers continue to search for biomarkers for specific neonatal disease processes. Clinicians frequently trend C-reactive protein levels during evaluation for neonatal sepsis. Recently, researchers have begun to explore procalcitonin as a potentially useful diagnostic marker for neonatal sepsis.

Examining the utility of the CD64 index compared with other conventional indices for early diagnosis of neonatal infection

As specific clinical manifestations and detection tools for early neonatal infections are lacking, early detection and treatment are ongoing challenges. The present study aimed to investigate the role and clinical significance of the CD64 index in comparison with conventional examination indices (WBC, PCT and CRP) for the early diagnosis of neonatal infection. Of 74 in-patient newborns, non-sepsis (non-specific infection but free of sepsis), sepsis and control [newborns with ABO hemolytic disease of the newborn (ABOHDN) but without infection] groups involved 32, 16 and 26 cases, respectively. Peripheral blood WBC, PCT, CRP and CD64 indices were acquired for all groups. The sepsis group showed significantly higher WBC, PCT and CRP levels than the control group. Compared with the non-sepsis group, the sepsis group demonstrated significant increases in PCT but not in WBC or CRP. Compared with the control group, the non-sepsis and sepsis groups had higher CD64 indices. Combined, compared with the WBC, PCT and CRP indices, the CD64 index is unique in its capacity to diagnose neonatal infections early. The CD64 index combined with other conventional indices may lay a basis for the future early diagnosis and effective treatment of neonatal infections.

Comparison of serum PCT and CRP levels in patients infected by different pathogenic microorganisms: a systematic review and meta-analysis

To avoid the abuse and misuse of antibiotics, procalcitonin (PCT) and C-reactive protein (CRP) have been used as new approaches to identify different types of infection. Multiple databases were adopted to search relevant studies, and the articles that satisfied the inclusion criteria were included. Meta-analyses were conducted with Review Manager 5.0, and to estimate the quality of each article, risk of bias was assessed. Eight articles satisfied the inclusion criteria. The concentrations of both PCT and CRP in patients with bacterial infection were higher than those with non-bacterial infection. Both PCT and CRP levels in patients with G− bacterial infection were higher than in those with G+ bacterial infection and fungus infection. In the G+ bacterial infection group, a higher concentration of CRP was observed compared with fungus infection group, while the difference of PCT between G+ bacterial infection and fungus infection was not significant. Our study suggested that both PCT and CRP are helpful to a certain extent in detecting pneumonia caused by different types of infection.

Diagnostic Value of PCT and CRP for Detecting Serious Bacterial Infections in Patients With Fever of Unknown Origin: A Systematic Review and Meta-analysis

BACKGROUND

It is vital to recognize the cause of an infection to enable earlier treatment. Studies have shown that procalcitonin (PCT) and C-reactive protein (CRP) have very high sensitivity and specificity for diagnosing serious bacterial infections (SBIs), with PCT performing better than CRP.

METHODS

Multiple databases were searched for relevant studies, and full-text articles involving diagnosis with PCT and CRP were reviewed. All meta-analyses were conducted with Review Manager 5.0. Sensitivity and bias analyses were performed to evaluate the quality of articles. In addition, a funnel plot and Egger test were used to assess possible publication bias.

RESULT

A total of 17 articles met the criteria for inclusion. The concentrations of both PCT and CRP were higher in the SBI group than in the nonbacterial infection group. Sensitivity for differentiating bacterial infections from nonbacterial infections was higher for PCT compared with CRP, whereas there was no significant difference in specificity. The area under the summary receiver operating characteristic curve for PCT was larger than that for CRP.

CONCLUSION

Both PCT and CRP are useful markers and should be used to evaluate SBIs with fever of unknown origin.

The diagnostic utility of procalcitonin, interleukin-6 and interleukin-8, and hyaluronic acid in the Norwegian consensus definition for early-onset neonatal sepsis (EONS)

Introduction

A key challenge in identifying serious bacterial infection in new born infants is the nonspecific clinical presentation of early-onset neonatal sepsis (EONS). Routinely used C-reactive protein, white blood cell count, and platelets are nonspecific. We assessed the diagnostic utility of single biomarkers or combinations of procalcitonin (PCT), interleukin (IL)-6, IL-8, and hyaluronic acid (HA) in newborn infant with EONS, and in human umbilical cord blood (HUCB) from deliveries with chorioamnionitis.

Materials and methods

Blood was collected from term infants with strictly defined EONS (group 1, n=15), healthy term infants (group 2, n=15), and the umbilical vein from pregnancies with suspected chorioamnionitis (group 3, n=8), and from healthy pregnancies with no signs of infection (group 4, n=15).

Results

Neonatal plasma PCT and IL-8 showed good predictive value (90% and 83%) for EONS, and the combination of IL-6 or HA with PCT increased the predictability to 87% and 90%, respectively. PCT, IL-6, IL-8, and HA were 8.4-, 4.5-, 3.6-, and 1.9-fold higher when compared with plasma levels in noninfected neonates. PCT, IL-6, and IL-8 in HUCB predicted chorioamnionitis and fever in the delivering mother (89%, 83%, and 72%, respectively). HA was a poor predictor (59%), but its predictability increased in combination with PCT, IL-8, or IL-6. In HUCB from chorioamnionitic deliveries, IL-6, IL-8, and PCT were 23-, 14-, and 2.4-fold higher, respectively, when compared with HUCB from healthy deliveries. There was no correlation between C-reactive protein, white blood cell, and platelet count with PCT, IL-6, IL-8, or HA.

Conclusion

In neonates that fulfilled the Norwegian consensus definition of neonatal sepsis, PCT, IL-6, and IL-8, but not HA, have the potential to improve our management of neonates at risk. Except for PCT and IL-8, both with a predictability of >80% in neonatal plasma, combinations of biomarkers increased the predictability for EONS and chorioamnionitis.

Prediction of histological chorioamnionitis and neonatal and infantile outcomes using procalcitonin in the umbilical cord blood and amniotic fluid at birth

Aim

We aimed to clarify the usefulness of procalcitonin (PCT) in the evaluation of histological chorioamnionitis (CAM) and in the prediction of neonatal and infantile outcomes as a reference of interleukin‐6 (IL‐6).

Methods

Subjects were 36 singleton pregnant women delivered at 22–37 weeks’ gestation due to threatened premature delivery and/or preterm premature rupture of membranes. Cases were classified into the CAM and non‐CAM groups, according to Blanc's criteria. Comparisons were made on umbilical venous and amniotic fluid PCT levels among the groups. The relations between umbilical venous PCT and IL‐6 levels and neonatal and infantile outcomes were also analyzed.

Results

The umbilical venous PCT level in the CAM group (240.2 pg/mL, 125.4–350.3 pg/mL: median, first quartile–third quartile) was higher than that in the non‐CAM group (105.1, 50.2–137.5 pg/mL; P = 0.0006). There were no differences in the amniotic fluid PCT levels between the groups. There was a strong correlation between umbilical venous PCT and IL‐6 levels (correlation coefficient: 0.793). Among 10 cases with an umbilical venous PCT level of ≥170.0 pg/mL and six cases with IL‐6 ≥ 11.0 pg/mL, six (60.0%) and five cases (83.3%), respectively, had adverse neonatal and infantile outcomes. Among seven cases with adverse neonatal and infantile outcomes, six (85.7%) and five (71.4%) cases showed umbilical venous PCT levels of ≥170.0 pg/mL and IL‐6 levels of ≥11.0 pg/mL, respectively.

Conclusion

Similar to IL‐6, the umbilical venous PCT level is a promising parameter for predicting histological CAM and adverse neonatal and infantile outcomes related to in utero inflammatory status.

Diagnostics for neonatal sepsis: current approaches and future directions

Progress has been made in the reduction of morbidity and mortality from neonatal sepsis. However, diagnosis continues to rely primarily on conventional microbiologic techniques, which can be inaccurate. The objective of this review is to provide the clinician with an overview of the current information available on diagnosing this condition. We review currently available diagnostic approaches for documenting neonatal sepsis and also describe novel approaches for diagnosing infection in neonates who are under development and investigation. Substantial progress has been made with molecular approaches and further development of non-culture-based methods offer promise. The potential ability to incorporate antimicrobial resistance gene testing in addition to pathogen identification may provide a venue to incorporate a predominantly molecular platform into a larger program of neonatal care.

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

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

The Determination of Procalcitonin Concentration in Early-Onset Neonatal Infection

The aim of this study was to assess the clinical usefulness of blood procalcitonin (PCT) levels for the diagnosis and therapeutic monitoring of early-onset neonatal sepsis (EONS). PCT as well as C-reactive protein (CRP) levels and white blood cell (WBC) count were measured in venous blood from 57 infected and 72 uninfected neonates. Differences between groups for PCT, CRP, and WBC levels were significant. The threshold value on the receiver operating characteristic curve in the prediction of EONS was 5.33 ng/mL for PCT, 9.3 mg/L for CRP, and 14.9 × 10⁹/L for WBC. There was no effect of antibiotic administered to the mother on PCT, CRP, and WBC levels in neonatal blood sampled before treatment of EONS. Evidently reduced PCT levels are observed after 2 days of treatment. The authors conclude that prenatal antibiotic therapy does not reduce the value of PCT levels in blood for the diagnosis of EONS.

Biomarkers for the diagnosis of neonatal sepsis and necrotizing enterocolitis: Clinical practice guidelines

Sepsis and necrotizing enterocolitis are major contributors to morbidity and mortality in neonates, especially in those born preterm. While therapeutic interventions are available for both (for e.g. antibiotics), a major dilemma is early diagnosis so that these interventions can be done in a timely manner. As clinical evaluation alone is unreliable in identifying infants in the early stages of neonatal sepsis or necrotizing enterocolitis, there is a need to find specific biomarkers associated with these conditions to improve diagnostic capabilities. Optimal use of biomarkers in the identification and management of affected neonates requires an understanding of the properties of each marker within the timeline of the inflammatory response. We propose that early- and mid-phase markers such as neutrophil CD64 and procalcitonin should be combined with the late-phase biomarker C-reactive protein for maximal diagnostic benefit. Appropriately powered trials evaluating the serial measurements of these markers in decisions related to antibiotic stewardship in the neonatal population are indicated, in addition to more studies investigating other potentially useful biomarkers.

The effects of thyroid function on retinopathy of prematurity

OBJECTIVES

To assess whether TSH and fT4 have a role in the angiogenesis of vaso-obliteration and neovascularization which are the basic pathophysiology of ROP.

METHODS

In this retrospective case-control study, the control group (n = 56) included preterm newborns with risk for ROP while the laser group (n = 63) was recruited from cases who developed severe neovascularization and needed laser photocoagulation therapy. Considering the first (vaso-obliteration) and second (neovascularization) phases of the disease, in this study we researched the distribution of thyroid function tests between groups.

RESULTS

With regard to the first phase of the disease, TSH and fT4 showed no significant differences between the control and laser groups accordingly (P > 0.05). Likewise, in the second phase of ROP, there was no significant difference between the control and laser groups with respect to TSH and fT4 levels (P > 0.05).

CONCLUSION

We found that between the study groups, the levels of thyroid function tests did not have any significant differences, either in the first or the second phases of ROP which are the principal pathophysiology of the disease. Therefore, it was concluded that thyroid hormone values were not informative markers in the course of the disease in preterm babies at risk of developing ROP.

Procalcitonin is more likely to be released by the fetus rather than placental tissue during chorioamnionitis

AIMS

To analyze the relationship between maternal, cord blood and neonatal procalcitonin (PCT) levels in preterm deliveries with and without histologically proven chorioamnionitis (HCA).

METHODS

91 mother-infant pairs from 24+0 to 33+0 gestational weeks were analyzed. Procalcitonin was measured in all mothers within 24 hours before and subsequently in cord blood and in neonates within the first two hours after delivery. PCT levels were analysed in relationship to HCA and clinical outcome.

RESULTS

HCA was confirmed in 28 cases (31%). We found no differences in PCT values between HCA positive and negative groups in maternal blood (0.1±0.1 vs 0.09±0.09 ng/L, P = 0.76). PCT values in cord blood and neonates were significantly higher in the HCA positive compared to HCA negative group (0.23±0.1 vs 1.2±2.7 ng/L, P < 0.001 and 0.89±3.4 vs 4.2±9.3 ng/L, P < 0.0001 respectively). PCT values in neonates were significantly higher than those of cord blood. Levels were not influenced by the mode of delivery, gestational age or premature rupture of membranes. Chorioamnionitis was more frequently associated with early onset neonatal sepsis (36% in HCA group vs 5% in non HCA group, P < 0.0001). Comparison of other clinical data revealed no differences between HCA positive and negative groups.

CONCLUSION

This study showed higher PCT in cord and neonatal blood in the presence of proven histological chorioamnionitis. The measurement of PCT in mothers' blood is not helpful for diagnosis of HCA. The changes in PCT values shown suggest its production and release by fetal tissue.

The Association Between Serum Procalcitonin Levels and Severity of Coronary Artery Disease Assessed by SYNTAX Score in Patients With Acute Coronary Syndrome

The SYNTAX score (SX score) is a useful score for assessing the severity of coronary artery disease (CAD). Previous studies have demonstrated a close relationship between SX score and inflammation. Procalcitonin (PCT) is an early inflammatory marker, especially during sepsis. Thus, in this study, we aimed to investigate the relationship between SX score and serum PCT levels. A total of 545 patients were enrolled in this prospective cross-sectional study and were divided into 2 subgroups, according to their SX score. Serum PCT and high-sensitivity C-reactive protein levels were measured. Serum PCT levels were higher in the high SX score group compared to the low–intermediate SX score group ( P < .001). Serum PCT levels were an independent predictor of a high SX score in patients with acute coronary syndrome ( P = .001). As patients with a higher SX score had increased serum PCT levels on admission, serum PCT may be useful for identifying patients with severe CAD.

Age-specific percentile-based reference curve of serum procalcitonin concentrations in Japanese preterm infants

Procalcitonin (PCT) levels are elevated early after birth in newborn infants; however, the physiological features and reference of serum PCT concentrations have not been fully studied in preterm infants. The aims of the current study were to establish an age-specific percentile-based reference curve of serum PCT concentrations in preterm infants and determine the features. The PCT concentration peaked in infants at 1 day old and decreased thereafter. At 1 day old, serum PCT concentrations in preterm infants <34 weeks’ gestational age were higher than those in late preterm infants between 34 and 36 weeks’ gestational age or term infants ≥37 weeks’ gestational age. Although the 50-percentile value in late preterm and term infants reached the adult normal level (0.1 ng/mL) at 5 days old, it did not in preterm infants. It took 9 weeks for preterm infants to reach it. Serum PCT concentrations at onset in late-onset infected preterm infants were over the 95-percentile value. We showed that the physiological feature in preterm infants was significantly different from that in late preterm infants, even in those <37 weeks’ gestational age. To detect late-onset bacterial infection and sepsis, an age-specific percentile-based reference curve may be useful in preterm infants.

Early-Onset Neonatal Sepsis: Still Room for Improvement in Procalcitonin Diagnostic Accuracy Studies

To perform a systematic review assessing accuracy and completeness of diagnostic studies of procalcitonin (PCT) for early-onset neonatal sepsis (EONS) using the Standards for Reporting of Diagnostic Accuracy (STARD) initiative.EONS, diagnosed during the first 3 days of life, remains a common and serious problem. Increased PCT is a potentially useful diagnostic marker of EONS, but reports in the literature are contradictory. There are several possible explanations for the divergent results including the quality of studies reporting the clinical usefulness of PCT in ruling in or ruling out EONS.We systematically reviewed PubMed, Scopus, and the Cochrane Library databases up to October 1, 2014. Studies were eligible for inclusion in our review if they provided measures of PCT accuracy for diagnosing EONS. A data extraction form based on the STARD checklist and adapted for neonates with EONS was used to appraise the quality of the reporting of included studies.We found 18 articles (1998-2014) fulfilling our eligibility criteria which were included in the final analysis. Overall, the results of our analysis showed that the quality of studies reporting diagnostic accuracy of PCT for EONS was suboptimal leaving ample room for improvement. Information on key elements of design, analysis, and interpretation of test accuracy were frequently missing.Authors should be aware of the STARD criteria before starting a study in this field. We welcome stricter adherence to this guideline. Well-reported studies with appropriate designs will provide more reliable information to guide decisions on the use and interpretations of PCT test results in the management of neonates with EONS.

Procalcitonin as a marker of respiratory disorder in neonates

BACKGROUND

Serum procalcitonin (PCT) increases in various respiratory disorders such as acute respiratory distress syndrome. Elevated PCT is also observed in healthy neonates. In this study, we investigated whether PCT is a good marker of respiratory disorder in neonates.

METHODS

A total of 155 neonates with or without respiratory disorder, were eligible for the study. PCT was measured on electrochemiluminescence immunoassay. Each neonate was allocated to the non-respiratory disorder (control) group (n = 95), or a respiratory disorder group (n = 60). PCT was compared between the groups, and association with other markers, including C-reactive protein (CRP) and white blood cell (WBC) count, was analyzed.

RESULTS

Of the 60 neonates in the respiratory disorder group, 39, 10, five, one, two, two, and one neonates had transient tachypnea of the newborn, respiratory distress syndrome, air leak syndrome, meconium aspiration syndrome, 18-trisomy, neonatal asphyxia, and congenital diaphragmatic hernia, respectively. Mean PCT, CRP and WBC count in the respiratory disorder group were 9.01 ng/mL, 0.26 mg/dL, and 16,100 cells/μL, respectively. The area under the curve obtained for PCT in distinguishing between the respiratory disorder and control groups was 0.85 (sensitivity, 66.7%; specificity, 93.0%; optimum cut-off, 3.73 ng/mL), that for CRP was 0.72 (sensitivity, 75.0%; specificity, 64.6%; optimum cut-off, 0.14 mg/dL), and for WBC it was 0.44 (sensitivity, 60.0%; specificity, 29.6%; optimum cut-off, 15,000 cells/μL).

CONCLUSIONS

PCT is more susceptible, as a diagnostic parameter of infection, to the effect of respiratory disturbance than CRP and WBC.

Procalcitonin as an Early Predictor of Contrast-Induced Acute Kidney Injury in Patients With Acute Coronary Syndromes Who Underwent Percutaneous Coronary Intervention

Contrast-induced acute kidney injury (CI-AKI) is a major issue after percutaneous coronary intervention (PCI), especially in the setting of acute coronary syndrome (ACS). Contrast-induced acute kidney injury is associated with increased mortality and morbidity. Inflammation plays an important role in the pathophysiology of CI-AKI. Procalcitonin (PCT) is introduced as a new marker of inflammation. We sought to examine whether admission PCT levels predict the development of CI-AKI. Patients (n = 814) were divided into 2 groups, namely, CI-AKI (-) and CI-AKI (+). An increase in serum creatinine of ≥0.5 mg/dL from baseline within 48 to 72 hours of contrast exposure was defined as CI-AKI. Contrast-induced acute kidney injury occurred in 96 (11.8%) patients. The PCT levels were significantly higher in patients with CI-AKI than in those without, 0.11 (0.056-0.495) vs 0.04 (0.02-0.078) µg/L; P < .001. After multivariable analysis, PCT remained a significant independent predictor of CI-AKI (odds ratio 2.544; 95% CI [1.207-5.347]; P = .014) as well as age, women, white blood cell, hemoglobin, glomerular filtration rate, creatine kinase myocarial band, and SYNTAX score. In conclusion, serum PCT levels are independently associated with a risk of CI-AKI in patients with ACS who underwent urgent PCI.

Reference Intervals of Serum Procalcitonin Are Affected by Postnatal Age in Very Low Birth Weight Infants during the First 60 Days after Birth

BACKGROUND

Procalcitonin (PCT) may be a more sensitive marker for neonatal bacterial infections than C-reactive protein (CRP). However, the reference intervals of serum PCT were not sufficiently studied in neonates older than 1 week of age, especially for very low birth weight infants.

OBJECTIVES

This study investigated the reference level of serum PCT for neonates according to gestational age (GA) and postnatal age (PNA).

METHODS

Serum PCT was measured in 914 blood samples from 7-60 days after birth in 415 neonates including 184 premature infants. Infants with sepsis, congenital anomaly, or clinically evident intra-amniotic infections were excluded. Multivariate analysis of covariance was used to detect the interaction between GA and PNA. To compare subgroups dichotomized by GA and PNA, analysis of covariance was performed with clinical parameters as covariates to obtain an adjusted p value.

RESULTS

Serum PCT levels were negatively correlated with GA, PNA, birth weight, birth height, and platelet count, and positively correlated with white blood cell count, absolute neutrophil count, hematocrit, and serum CRP after logarithmic transformation. Reference intervals of serum PCT were established according to GA and PNA. High PCT levels were found in infants with GA ≤32 weeks and PNA 7-30 days.

CONCLUSION

The reference levels of serum PCT were determined according to GA and PNA. As the reference PCT levels of infants with GA ≤32 weeks were affected by PNA, cautious interpretation of PCT levels in these infants is warranted.

Procalcitonin levels in fresh serum and fresh synovial fluid for the differential diagnosis of knee septic arthritis from rheumatoid arthritis, osteoarthritis and gouty arthritis

Whether the levels of procalcitonin (PCT) in the serum and synovial fluid are effective indicators for distinguishing septic arthritis (SA) from non-infectious arthritis remains controversial. The present study aimed to evaluate whether PCT levels in fresh serum or fresh joint fluid may be used in the differential diagnosis of SA from rheumatoid arthritis (RA), osteoarthritis (OA) and gouty arthritis (GA). From January 2012 to June 2013, 23 patients with knee SA, 21 patients with RA, 40 patients with OA and 11 patients with GA were enrolled in the current study. The levels of PCT were measured within 24 h after specimen collection at room temperature. An enzyme-linked fluorescence assay (ELFA) was used to detect the levels of PCT in the serum and synovial fluid. The correlations between the levels of PCT in the serum and synovial fluid and the arthritic patient groups were determined by the Nemenyi test. Areas under the receiver operating characteristic (ROC) curve were calculated to evaluate the accuracy of the correlations. The levels of PCT in the serum and joint fluid of the patients in the SA group were higher compared with those of the other groups (P<0.01) and there were no significant differences among the RA, OA and GA groups in these levels. A PCT level of <0.5 μg/l in the serum and synovial fluid had high specificity in the differential diagnosis of SA from RA, OA and GA. Synovial fluid PCT revealed significantly greater sensitivity than serum PCT. The accuracy of the differential diagnosis of SA by the serum levels of PCT was significantly lower than that by the synovial fluid levels of PCT. The levels of PCT in the serum and synovial fluid may be used as alternative laboratory indicators to distinguish between SA and the non-infectious types of arthritis; however, the PCT levels in fresh synovial fluid are more sensitive and accurate indicators than PCT levels in fresh serum.

Early-onset neonatal sepsis

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

Neonatal sepsis: an old problem with new insights

Neonatal sepsis continues to be a common and significant health care burden, especially in very-low-birth-weight infants (VLBW <1500 g). Though intrapartum antibiotic prophylaxis has decreased the incidence of early-onset group B streptococcal infection dramatically, it still remains a major cause of neonatal sepsis. Moreover, some studies among VLBW preterm infants have shown an increase in early-onset sepsis caused by Escherichia coli. As the signs and symptoms of neonatal sepsis are nonspecific, early diagnosis and prompt treatment remains a challenge. There have been a myriad of studies on various diagnostic markers like hematological indices, acute phase reactants, C-reactive protein, procalcitonin, cytokines, and cell surface markers among others. Nonetheless, further research is needed to identify a biomarker with high diagnostic accuracy and validity. Some of the newer markers like inter α inhibitor proteins have shown promising results thereby potentially aiding in early detection of neonates with sepsis. In order to decrease the widespread, prolonged use of unnecessary antibiotics and improve the outcome of the infants with sepsis, reliable identification of sepsis at an earlier stage is paramount.

Procalcitonin in pediatrics

Over the past two decades, the body of literature on the clinical usefulness of procalcitonin (PCT) in adults has grown rapidly. Although this approach has led to increased insight, it has also prompted debate regarding its potential use in diagnosis and management of severe infection. Clinicians, however, are less familiar with the use of PCT in pediatric populations. In this review, we examine PCT as a marker of severe clinical pediatric conditions including its role in systemic inflammation, infection, and sepsis.