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

Immature neutrophils in cord blood exert increased expression of genes associated with antimicrobial function

Introduction

The immune systems of both the mother and the newborn face significant challenges during birth. Proper immune regulation after birth is essential for the survival of neonates. Numerous studies have demonstrated that the neonatal immune system is relatively immature, particularly in its adaptive arm, placing the primary responsibility for immune surveillance on innate immunity.

Methods

Given the significant role of neutrophils in protecting the neonate after birth, we conducted a study investigating the properties of neutrophils in newborn cord blood using various methodological approaches.

Results

Our findings demonstrate the presence of immature low-density neutrophils in the cord blood, which are likely responsible for the observed elevated expression of genes coding for proteins essential to antimicrobial response, including myeloperoxidase, neutrophils elastase, and defensins.

Discussion

We propose that these cells function normally and support the protection of newborns early after birth. Furthermore, our results suggest that the mode of delivery might significantly influence the programming of neutrophil function. The presented findings emphasize the importance of distinct neutrophil subpopulations in neonatal immunity and their potential impact on early postnatal health.

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.

The role of presepsin in pediatric patients with oncological and hematological diseases experiencing febrile neutropenia

Febrile neutropenia (FN) represents one of the main complications of pediatric patients with oncological and hematological diseases. In these patients, it is crucial to identify bacterial infections. The aim of this study is to evaluate presepsin as an early biomarker of bacterial infections during FN. We compared patients with oncological and hematological diseases and a 2:1 age-matched healthy control group. In the FN group, we evaluated 4 biomarkers, namely, C reactive protein (CRP), procalcitonin (PCT), interleukin 6 (IL6) and presepsin at the onset of fever (T0) and 48 h after T0 (T1). In the control group, we only evaluated presepsin. We enrolled a total of 41 children with oncological and hematological diseases disease experiencing 50 FN episodes and 100 healthy patients in the control group. In patients with FN, we found that presepsin was significantly higher than in the control group (p < 0.001). However, in the FN group, we did not find a statistically significant difference between patients with and without bacteremia (p = 0.989 at T0, p = 0.619 at T1). Presepsin values at T1 were higher in patients experiencing an unfavorable outcome (p = 0.025). This study shows that presepsin increases in neutropenic patients, but it only revealed useful in predicting an unfavorable outcome 48 h from the onset of fever.

Presepsin for the Diagnosis of Neonatal Early-Onset Sepsis: A Systematic Review and Meta-analysis

IMPORTANCE

Neonatal early-onset sepsis (EOS) is a severe disease, particularly in preterm infants. Timely diagnosis can be challenging owing to unspecific presentation and questionable performance of the common markers of infection. Presepsin was recently proven to be a promising biomarker for the diagnosis of EOS.

OBJECTIVE

To assess presepsin accuracy for the diagnosis of EOS.

DATA SOURCES

PubMed Medline, EMBASE, Web of Science, and Google Scholar. No publication date restrictions were applied. The literature search was limited to the English language. Articles were checked for duplication.

STUDY SELECTION

Inclusion criteria were studies that (1) included term or preterm newborns (defined as newborns with gestational age ≥37 weeks or <37 weeks, respectively); (2) included a diagnosis of EOS, defined as culture-proven sepsis for primary analysis and as either clinical or culture-proven sepsis for secondary analysis; and (3) assessed presepsin values during the initial workup for suspected EOS. Exclusion criteria were studies that (1) did not include EOS cases; (2) lacked data on presepsin sensitivity and/or specificity; and (3) were case reports, commentaries, or reviews. Two independent reviewers performed the study selection.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers performed data extraction and quality assessment. Quality assessment was performed using the Quality Assessment for Studies of Diagnostic Accuracy 2 tool, and data were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data were pooled using a random-effects model.

MAIN OUTCOMES AND MEASURES

The outcomes of interest for both the primary and secondary analyses were presepsin sensitivity, specificity, and diagnostic odds ratio for the diagnosis of EOS.

RESULTS

A total of 12 studies of 245 (4.9%) met inclusion criteria for the primary analysis. Twenty-three studies of 245 (9.4%) met the inclusion criteria for the secondary analysis. In the primary analysis, among 12 studies and 828 newborns of any gestational age, pooled sensitivity and specificity were 0.93 (95% CI, 0.86-0.95) and 0.91 (95% CI, 0.85-0.95), respectively; pooled diagnostic odds ratio was 131.69 (95% CI, 54.93-310.94). Subgroup analysis showed that presepsin specificity was associated with the inclusion of only EOS or all neonatal sepsis. Presepsin accuracy was not associated with gestational age, measurement with chemiluminescence enzyme immunoassay or enzyme-linked immunosorbent assay testing, country where the study was performed, or risk of bias judgment. In the secondary analysis, among 23 studies and 1866 newborns, accuracy was significantly associated with only test type.

CONCLUSIONS AND RELEVANCE

Results of this systematic review and meta-analysis suggest that presepsin was an accurate biomarker of EOS. Clinical trials are warranted to assess its usefulness and safety to reduce early antibiotic exposure, particularly in preterm newborns.

Perinatal presepsin assessment: a new sepsis diagnostic tool?

Perinatal sepsis constitutes a medical emergency and is still one of the major causes of mortality and morbidity. The possibility of an early diagnosis of sepsis is still debated and controversial. In particular, clinical symptoms can be hidden by the association of sepsis with other perinatal diseases and/or by therapeutic strategies performed. In this context, there is evidence that the accuracy of standard of care diagnostic parameters (i.e. blood culture, C-reactive protein, procalcitonin) can be biased by additional confounding factors (gestational age, birth-weight, acute-chronic hypoxia). Therefore, the inclusion in clinical daily practice of new biomarkers of sepsis is of utmost importance. Of a panel of biomarkers, Presepsin (P-SEP) plays an important role in the development and response of the immune system and as an early marker of sepsis both in adult and pediatric patients. Therefore, in the present review we aim to offer an overview of the role of P-SEP in the early detection of perinatal sepsis as a trustworthy marker according to actual statements of official international institutions. Future perspectives regard the possibility of a longitudinal non-invasive biological fluids P-SEP assessment thus limiting the sample stress in high risk newborns.

Perinatal asphyxia partly affects presepsin urine levels in non-infected term infants

OBJECTIVES

Standard of care sepsis biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT) can be affected by several perinatal factors, among which perinatal asphyxia (PA) has a significant role. In this light, new early sepsis biomarkers such as presepsin (P-SEP) are needed to enact therapeutic strategies at a stage when clinical and laboratory patterns are still silent or unavailable. We aimed at investigating the potential effects of PA on longitudinal P-SEP urine levels.

METHODS

We conducted an observational case-control study in 76 term infants, 38 with PA and 38 controls. Standard clinical, laboratory, radiological monitoring procedures and P-SEP urine measurement were performed at four time-points (first void, 24, 48, 96 h) after birth.

RESULTS

Higher (p<0.05) CRP and PCT blood levels at T1-T3 were observed in PA than control infants whilst no differences (p>0.05, for all) at T0 were observed between groups. P-SEP urine levels were higher (p<0.05) in PA at first void and at 24 h while no differences (p>0.05) at 48 and 96 h were observed. No significant correlations were found (p>0.05) between P-SEP and urea (R=0.11) and creatinine (R=0.02) blood levels, respectively.

CONCLUSIONS

The present results, showed that PA effects on P-SEP were limited up to the first 24 h following birth in absence of any kidney function bias. Data open the way to further investigations aimed at validating P-SEP assessment in non-invasive biological fluids as a reliable tool for early EOS and LOS detection in high-risk infants.

Related Markers for the Precision Diagnosis of Complex Appendicitis in Children

Acute appendicitis is the most common surgical emergency in children. Despite the high incidence rate of appendicitis, it is sometimes misdiagnosed or missed. Complex appendicitis (CA) in children is characterized by a critical condition, several complications, and high mortality. Precision distinguishing between simple appendicitis and CA correctly is key to choosing appropriate treatment. A safe, cheap, rapid, extensive and accurate diagnostic marker of appendicitis will be of great significance for emergency general surgeons to treat suspected CA. Many studies have investigated possible diagnostic markers for the diagnosis of CA in children. In this study, studies related to CA in children in recent years are summarized, and the related markers and scoring system for the diagnosis of CA in children are summarized.

Aberrant long non-coding RNA cancer susceptibility 15 (CASC15) plays a diagnostic biomarker and regulates inflammatory reaction in neonatal sepsis

Neonatal sepsis (NS) is one of the important causes of neonatal death. There are many studies to confirm the role of long non-coding RNA (lncRNA) in neonatal infectious diseases. This study aimed to explore the level of cancer susceptibility 15 (CASC15) and its effect on inflammatory response in NS. Seventy-nine neonatal pneumonia (NP) patients and 80 NS patients were enrolled in this study. Reverse Transcription-quantitative PCR (RT-qPCR) was used to determine the expression levels of CASC15 and miR-144-3p. Receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic value of CASC15 in NS. RAW264.7 cells were stimulated with LPS to simulate the inflammatory response in NS patients, and the regulation and mechanism of CASC15 on the inflammatory response were explored in this in vitro cell model. Serum CASC15 was upregulated in NS patients, and it had the ability to distinguish NS patients from NP patients. LPS stimulation increased the expression of CASC15 and simultaneously stimulated the secretion of inflammatory cytokines, while the knockdown of CASC15 alleviated the inflammatory response induced by LPS stimulation. Besides, serum miR-144-3p was reduced in NS patients, and luciferase reporter genes showed that miR-144-3p was a direct target of CASC15. Overexpression of CASC15 may promote the inflammatory response of NS by targeted regulating the expression of miR-144-3p, which may provide us with new insights in the treatment of NS.

The Emerging Role of Presepsin (P-SEP) in the Diagnosis of Sepsis in the Critically Ill Infant: A Literature Review

Sepsis causes high rates of morbidity and mortality in NICUs. The estimated incidence varies between 5 and 170 per 1000 births, depending on the social context. In very low birth-weight neonates, the level of mortality increases with the duration of hospitalization, reaching 36% among infants aged 8-14 days and 52% among infants aged 15-28 days. Early diagnosis is the only tool to improve the poor prognosis of neonatal sepsis. Blood culture, the gold standard for diagnosis, is time-consuming and poorly sensitive. C-reactive protein and procalcitonin, currently used as sepsis biomarkers, are influenced by several maternal and fetal pro-inflammatory conditions in the perinatal age. Presepsin is the N-terminal fragment of soluble CD14 subtype (sCD14-ST): it is released in the bloodstream by monocytes and macrophages, in response to bacterial invasion. Presepsin seems to be a new, promising biomarker for the early diagnosis of sepsis in neonates as it is not modified by perinatal confounding inflammatory factors. The aim of the present review is to collect current knowledge about the role of presepsin in critically ill neonates.

Diagnostic, Prognostic, Predictive, and Monitoring Role of Neutrophil CD11b and Monocyte CD14 in Neonatal Sepsis

Background

Sepsis is a critical medical condition that requires additional diagnostic considerations. Recently, focus has shifted to the diagnosis of sepsis using new markers to overcome the limitations of traditional laboratory diagnostic modalities. Neutrophil CD11b (nCD11b) and monocyteCD14 (mCD14) cell surface antigens have been shown to be useful in such diagnostic consideration.

Aim

To investigate the diagnostic, monitoring, prognostic, and predictive roles of nCD11b and mCD14 as sepsis biomarkers in comparison to each other and to traditional laboratory sepsis parameters in order to select the best fit for routine daily use in neonatal intensive care units (NICUs).

Subject

The study included 188 neonates from Ain Shams University Hospitals' NICUs, who were divided into two groups: the control group (n = 100) and the sepsis group (n = 88). Highly sensitive CRP (hs-CRP), complete blood count (CBC), blood culture, and nCD11b and mCD14 evaluations were all part of the laboratory sepsis evaluation (done by flow cytometry technology). Positive blood culture results (BACT/ALERT system) confirmed the sepsis diagnosis. Twenty-four enrolled sepsis neonates were subjected to follow-up assessments, and they were divided into two groups based on clinical improvement: improved sepsis and sepsis without improvement. In order to predict performance evaluation, the subjected neonates were reclassified according to their outcome into survivors' and nonsurvivors' group.

Results

Sepsis patients had a significant increase in mCD14 MFI values when compared to controls. With sensitivity 75.4 percent, specificity 71.9 percent, efficacy 73.3 percent, and AUC 0.703, mCD14 MFI at cutoff 9.36 could distinguish the presence of septicemia. Significant increases in both mCD14 MFI and nCD11b MFI (P = 0.001) were observed in the severe sepsis/septic shock group compared to the nonsevere sepsis group. The combined measurement of CD14 MFI at cutoff 9.97 and CD14 percent at cutoff 44.7 percent yielded the best predictive performance.

Conclusion

Sepsis patients had a significant increase in mCD14 MFI comparable to the controls. mCD14 MFI demonstrated better diagnostic, prognostic, and predictive results than nCD11b. hs-CRP outperformed mCD14 and nCD11b in terms of diagnostic efficacy and AUC. In the monitoring of sepsis patients, both mCD14 and nCD11b produced unsatisfactory results. Currently, the routine use of mCD14 or nCD11b as sepsis biomarkers in neonatal ICUs is not justified.

High expression of neutrophil and monocyte CD64 with simultaneous lack of upregulation of adhesion receptors CD11b, CD162, CD15, CD65 on neutrophils in severe COVID-19

Background and Aims

The pronounced neutrophilia observed in patients with coronavirus disease 2019 (COVID-19) infections suggests a role for these leukocytes in the pathology of the disease. Monocyte and neutrophil expression of CD64 and CD11b have been reported as early biomarkers to detect infections. The aim of this study was to study the expression of receptors for IgG (CD64) and adhesion molecules (CD11b, CD15s, CD65, CD162, CD66b) on neutrophils and monocytes in patients with severe COVID-19 after admission to an intensive care unit (ICU).

Methods

The expression of receptors was analyzed using flow cytometry. EDTA blood from 23 patients with confirmed COVID-19 infection was sampled within 48 h of admission to the ICU. Leukocytes were labeled with antibodies to CD11b, CD15s, CD65s, CD162, CD64, and CD66b. Expression of receptors was reported as mean fluorescence intensity (MFI) or the percentage of cells expressing receptors.

Results

Results are presented as comparison of COVID-19 patients with the healthy group and the receptor expression as MFI. Neutrophil receptors CD64 (2.5 versus 0.5) and CD66b (44.5 versus 34) were increased and CD15 decreased (21.6 versus 28.3) when CD65 (6.6 versus 4.4), CD162 (21.3 versus 21.1) and CD11b (10.5 versus 12) were in the same range. Monocytes receptors CD64 (30.5 versus 16.6), CD11b (18.7 versus 9.8), and CD162 (38.6 versus 36.5) were increased and CD15 decreased (10.3 versus 17.9); CD65 were in the same range (2.3 versus 1.96).

Conclusion

Monocytes and neutrophils are activated during severe COVID-19 infection as shown by strong upregulation of CD64. High monocyte and neutrophil CD64 can be an indicator of a severe form of COVID19. The adhesion molecules (CD11b, CD162, CD65, and CD15) are not upregulated on otherwise activated neutrophils, which might lead to relative impairment of tissue migration. Low adhesion profile of neutrophils suggests immune dysfunction of neutrophils. Monocytes maintain upregulation of some adhesion molecules (CD11b, CD162) suggesting the persistence of an increased ability to migrate into tissues, even during a severe stage of COVID-19. Future research should focus on CD64 and CD11b kinetics in the context of prognosis.

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.

Tracheal aspirate presepsin: a promising biomarker in early onset neonatal pneumonia

The early recognition and management of early-onset neonatal pneumonia is a challenge facing intensivists. Presepsin is an emerging immunologic and inflammatory biomarker that has been used for early non-culture-based detection of infection. We aimed to clarify the potential of presepsin assessed in tracheal aspirate of newborns to identify pneumonia. This prospective case - control study was conducted on 60 intubated neonates: Thirty neonates with pneumonia diagnosed according to clinical, radiological, and laboratory criteria as pneumonia group and thirty age and sex-matched intubated neonates without pneumonia as a control group. All neonates underwent full clinical evaluation and laboratory investigations. Plasma and tracheal aspirate presepsin was determined on the first day of life. The means of tracheal aspirate and plasma presepsin and CRP (525.55 ± 94.62 pg/mL, 670.95 ± 120.38 pg/mL and 26.4 ± 11.2 mg/L, respectively) were significantly higher in pneumonia group than control group (252.51 ± 104.95 pg/mL, 553.79 ± 117.48 pg/mL, 15.1 ± 3.1 mg/L, respectively) (p < .001 each). Receiver operating characteristic curve analysis for tracheal aspirate and plasma presepsin and CRP levels for the prediction of early-onset neonatal pneumonia was designed. Sensitivity was 86.6, 70 and 56.7%, respectively, while specificity was 90, 73.3, 53.3%, respectively, at a cut-off point of 385 pg/mL, 605 pg/mL and 36 mg/L, respectively [area under the curve (AUC) = 0.97, 0.74 and 0.51, respectively, p < .001, .001 and .44, repectively]. In conclusion, tracheal aspirate presepsin is increased in early-onset neonatal pneumonia and outperformed other plasma biomarkers in diagnosing neonatal pneumonia.