Comparison of the accuracy of neutrophil CD64 and C-reactive protein as a single test for the early detection of neonatal sepsis

P75NTR+CD64+ neutrophils promote sepsis-induced acute lung injury

Patients suffering from sepsis-induced acute lung injury (ALI) exhibit a high mortality rate, and their prognosis is closely associated with infiltration of neutrophils into the lungs. In this study, we found a significant elevation of CD64+ neutrophils, which highly expressed p75 neurotrophin receptor (p75NTR) in peripheral blood of mice and patients with sepsis-induced ALI. p75NTR+CD64+ neutrophils were also abundantly expressed in the lung of ALI mice induced by lipopolysaccharide. Conditional knock-out of the myeloid lineage's p75NTR gene improved the survival rates, attenuated lung tissue inflammation, reduced neutrophil infiltration and enhanced the phagocytic functions of CD64+ neutrophils. In vitro, p75NTR+CD64+ neutrophils exhibited an upregulation and compromised phagocytic activity in blood samples of ALI patients. Blocking p75NTR activity by soluble p75NTR extracellular domain peptide (p75ECD-Fc) boosted CD64+ neutrophils phagocytic activity and reduced inflammatory cytokine production via regulation of the NF-κB activity. The findings strongly indicate that p75NTR+CD64+ neutrophils are a novel pathogenic neutrophil subpopulation promoting sepsis-induced ALI.

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.

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.

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.

Cell-Surface Biomarkers, C-Reactive Protein and Haematological Parameters for Diagnosing Late Onset Sepsis in Pre-term Neonates

OBJECTIVE

To compare the diagnostic accuracy of white blood cell-surface biomarkers (CD64, CD11b and HLA-DR), C-reactive protein (CRP) and hematological parameters to diagnose definite sepsis among pre-term neonates presenting with suspected late-onset neonatal sepsis (LONS).

DESIGN

This was a prospective, single-gate, diagnostic study in a Level III neonatal unit. Fifty-three neonates (gestation, <34 weeks) with LONS (onset, >72  age), were enrolled. Cell-surface biomarkers, CRP and haematological parameters were assayed at 0 and 48 h after onset. The reference standard was definite sepsis, defined as a positive blood culture with a non-contaminant organism. The index tests (cell-surface biomarkers, CRP and haematological parameters) were compared between subjects with or without 'definite sepsis'. The area under the receiver operator characteristics curves (AUC) generated for each index test at 0 and 48 h was compared.

SETTING

Level III neonatal unit in a tertiary care institute.

RESULTS

Of 53 enrolled pre-term infants, 24 had definite sepsis. Among all the index tests evaluated, CRP at 48 h had the highest AUC [0.82 (95% confidence interval, 0.69, 0.92)]. The expression of CD11b and HLA-DR was significantly reduced among the septic neonates. Among the cell-surface biomarkers, the maximum AUC was recorded for HLA-DR at 48  [0.68 (95% CI, 0.54, 0.81)]. Comparisons between index tests were not statistically significant.

CONCLUSION

C-reactive protein is superior to other sepsis screen biomarkers and white blood cell-surface biomarkers in diagnosing culture-positive LONS among pre-term infants. CD64, CD11b and HLA DR as diagnostic tests in this group have limited discriminatory value.

LAY SUMMARY

The diagnosis of neonatal blood stream infections is a challenge. In response to bacterial blood stream infections, white blood cells are known to produce an excess of certain types of specialized proteins on their surface, including CD64, CD11b and HLA-DR. In this study we evaluated the concentration of these cell-surface proteins for diagnosing blood stream infections in pre-mature newborn babies, whose onset of infection was beyond 72 h of life. We compared these tests against standard tests that are currently in clinical use, such as C-reactive protein and blood white cell counts. All tests were performed at the time of initially suspecting the infection and 48 h later. The gold standard against which all these tests were evaluated was blood culture, in which the offending bacteria are grown in specialized laboratory media. Of 53 pre-mature babies with suspected infection, 24 had blood culture-proven infection. Among all tests, C-reactive protein at 48 h had the best ability to distinguish definite infection from no infection. The expression of CD11b and HLA-DR was significantly reduced among infected neonates. We conclude that C-reactive protein is superior to white blood cell-surface proteins and white cell count in diagnosing definite late-onset infections among pre-term infants.

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

Background

Neonatal septicemia is a critical medical situation; current conventional laboratory methods still have many limitations and diagnostic obstacles. For this purpose, last decades have witnessed a challenge between the battery of sepsis biomarkers including many leukocyte surface antigens, not only for early diagnostic purposes but also for better follow-up and good management of sepsis patients.

Aim

To evaluate the diagnostic, prognostic, and monitoring performance of both neutrophil CD64 (nCD64) and presepsin as sepsis biomarkers compared to each other and to the conventional laboratory sepsis parameters aiming to decide which is the best fitting for routine daily use in neonatal intensive care units (NICUs).

Methods

235 neonates were enrolled from three Egyptian neonatal ICUs, during the period from November 2015 till March 2018; they were classified into two main groups: the control group (n = 102) and the sepsis group (n = 133). Laboratory sepsis evaluation included highly sensitive CRP (hs-CRP), CBC, in addition to nCD64 (flow cytometry technique), and presepsin measurement (CLEIA technique combined with Magtration® technology); the diagnosis was confirmed thereafter by positive blood culture results (BacT/Alert system). Sixty-two of the enrolled sepsis neonates were subjected to follow-up assessment; they were reclassified according to their clinical improvement at the second time assessment into (group 1: sepsis group without improvement) (n = 20) and (group 2: improved sepsis group) (n = 42).

Results

Significant increase in nCD64 and presepsin values was found in sepsis groups compared to the controls. At cutoff 41.6%, nCD64% could discriminate the presence of septicemia with sensitivity 94.7%, specificity 93.6 %, and AUC 0.925, while presepsin at cutoff 686 pg/ml achieves sensitivity 82.7%, specificity 95.5%, and AUC 0.887, respectively. Significant increase in nCD64 (P < 0.001) and hs-CRP (P=0.018) values was observed in severe sepsis/septic shock patients compared to nonsevere sepsis patients. Delta change percentage (dC%) between initial and follow-up evaluations for both improved and nonimproved sepsis patients was dC Z value −5.904 for nCD64% followed by dC Z value −4.494 for presepsin.

Conclusion

nCD64 and presepsin are valuable early diagnostic and monitoring sepsis biomarkers; the highest sensitivity could be achieved by a univariant sepsis marker in this study was recorded by the nCD64% biomarker, while the highest specificity was documented by presepsin. Combined measurement of both achieves the highest diagnostic performance in sepsis neonates. Either of CD64 or presepsin combined with hs-CRP associated with better performance than any of them alone. nCD64 carries an additional promising role in reflecting sepsis prognosis.

Valuable Role of Neutrophil CD64 and Highly Sensitive CRP Biomarkers for Diagnostic, Monitoring, and Prognostic Evaluations of Sepsis Patients in Neonatal ICUs

Background

Neonatal sepsis (NS) is a very critical medical situation associated with high morbidities and mortalities. There is an utmost need for a new tool helping in early diagnosis and proper management of sepsis neonates. Neutrophil CD64 (nCD64) shows a very promising value in this concerning issue.

Aim

Evaluate the diagnostic, monitoring, and prognostic performances of nCD64 and highly sensitive CRP (hs-CRP) in NS as well as the possible best panel of biomarkers that can achieve the most desirable results.

Methods

Patients were enrolled from three neonatal intensive care units (NICUs) (n = 121 patients) and classified according to their initial sepsis evaluation into three groups: disease control group (n = 30), proven sepsis group (n = 17), and clinical sepsis group (n = 74). Laboratory evaluation included hs-CRP, complete blood count (CBC), and blood culture in addition to nCD64 (done by flow cytometry technique). Besides the diagnostic evaluations, follow-up evaluations were done for 40 patients after five days from the first time; patients were reclassified according to their outcome into the improved sepsis neonates' group (n = 26) and sepsis neonates without improvement (n = 14).

Results

Significant increase in nCD64 and hs-CRP results were present in sepsis groups compared to the disease controls (P < 0.001); nCD64 at 43% cutoff value could detect the presence of sepsis with 85.6% sensitivity and 93% specificity. Additionally, delta change percentage (dC%) between improved sepsis neonates and sepsis neonates without improvement showed a significant difference in the levels of both nCD64 (P < 0.001) and hs-CRP (P = 0.001).

Conclusion

Besides the promising diagnostic performance documented by nCD64 which is higher than the other laboratory sepsis biomarkers used routinely in NICUs, nCD64 has a valuable role in sepsis patients' monitoring and prognostic evaluation. hs-CRP was moderate in its diagnostic and monitoring results being less than that achieved by nCD64. Combined measurement of nCD64% and hs-CRP gives better diagnostic and monitoring performance than that achieved by any of them alone.

Assessment of C-Reactive Protein Diagnostic Test Accuracy for Late-Onset Infection in Newborn Infants: A Systematic Review and Meta-analysis

IMPORTANCE

Rapid and accurate diagnosis of late-onset infection in newborn infants could inform treatment decisions and avoid unnecessary administration of antibiotics.

OBJECTIVE

To compare the accuracy of serum C-reactive protein (CRP) with that of microbiological blood culture for diagnosing late-onset infection in newborns.

DATA SOURCES

MEDLINE (1946-2019), Embase (1946-2019), and Science Citation Index (1900-2019) databases were searched for references (any language). The MeSH search terms included were "exp infant, newborn/" or "premature birth/" plus free text synonyms; and "C-reactive protein/" plus free text synonyms; and "exp sepsis/" or "exp bacterial infections/" plus free text synonyms. The proceedings from relevant conferences and references of identified papers were scrutinized. Authors were contacted to request missing data.

STUDY SELECTION

Cohort and cross-sectional studies were included that compared the accuracy of serum CRP levels with microbiological culture results to diagnose late-onset (>72 hours after birth) infection in newborns (any gestational age) hospitalized after birth. Two reviewers assessed study eligibility. Among 10 394 records, 148 studies were assessed as full texts.

DATA EXTRACTION AND SYNTHESIS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline extension for Diagnostic Test Accuracy (DTA) reviews was followed. Two reviewers assessed the method quality of each study using guidance from the Cochrane Screening and Diagnostic Test Methods Group (adapted from the Quality Assessment of Diagnostic Accuracy Studies 2).

MAIN OUTCOMES AND MEASURES

The primary meta-analysis outcome was diagnostic test accuracy of serum CRP level taken at initial investigation of an infant with suspected late-onset infection. The median specificity (proportion of true-negative results) and calculated pooled sensitivity (proportion of true-positive results) were determined by generating hierarchical summary receiver characteristic operating curves.

RESULTS

In total, 22 studies with 2255 infants were included (sample size range, 11-590 infants). Participants in most studies were preterm (<37 weeks) or very low-birth weight (<1500 g) infants. Two studies additionally enrolled infants born at term. Most studies (16) used a prespecified CRP level cutoff for a "positive" index test (5-10 mg/L), and most studies (17) used the culture of a pathogenic microorganism from blood as the reference standard. Risk of bias was low with independent assessment of index and reference tests. At median specificity (0.74), pooled sensitivity was 0.62 (95% CI, 0.50-0.72). Adding serum CRP level to the assessment of an infant with a 40% pretest probability of late-onset infection (the median for the included studies) generated posttest probabilities of 26% for a negative test result and 61% for a positive test result.

CONCLUSIONS AND RELEVANCE

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

Serum CD64 and ascitic fluid calprotectin and microRNA-155 as potential biomarkers of spontaneous bacterial peritonitis

AIM

Patients with ascites are at a higher risk for associated of on top bacterial infections with subsequent life-threatening complications. We aimed to evaluate CD64, calprotectin, and microRNA-155 (miR-155) levels as diagnostic markers of spontaneous bacterial peritonitis (SBP) and the effect of using more than one use on the same spot over their diagnostic efficiency.

PATIENTS AND METHODS

An observational comparative study included 103 patients with ascites admitted to the Tropical Medicine Department, Mansoura University Hospital, Egypt, divided into two groups: case group (64 patients) with ascites with SBP and control group (39 patients) with decompensated cirrhotic non-SBP ascites. Twenty milliliters of ascetic fluid was obtained from all participants for bacterial culture, and assessment of calprotectin and miR-155, in addition to 2 ml blood for the CD64 marker expression assay by a flowcytometer.

RESULTS

The sensitivity and specificity of CD64 expression assay were 95.3 and 92.3%, respectively, area under the curve (AUC)=0.93, whereas those of ascetic fluid calprotectin and miR-155 were 87.5 and 82.1%, AUC=0.90 and 95.3 and 97.4%, with AUC of 0.95. Combined blood CD64 and ascetic fluid calprotectin had a diagnostic accuracy of 0.988 for blood CD64 and ascetic fluid miR-155, AUC=0.991, and that for ascetic fluid calprotectin and miR-155 was 0.988. On using the three studied markers together, the diagnostic accuracy was the best recorded, AUC=0.994. P values were less than 0.001.

CONCLUSION

CD64, calprotectin, and miR-155 were good diagnostic markers of SBP and on using this combination, greater efficiency in diagnosis was achieved.

Accuracy of C-Reactive Protein Test for Neonatal Septicemia: A Diagnostic Meta-Analysis

BACKGROUND The aim of this study was to evaluate the diagnostic value of C-reactive protein (CRP) test in detecting neonatal septicemia. MATERIAL AND METHODS We searched the Cochrane Library, PubMed, Springer, MBASE, Elsevier Science Direct, and Medline databases up to March 2017. To collect relevant data on CRP testing in patients with neonatal septicemia, we performed a meta-analysis of positive likelihood ratio (LR), sensitivity, negative LR, specificity and diagnostic odds ratio (dOR) of CRP testing, using Stata 12.0 and Meta-DiSc 1.4 data analysis software. RESULTS Ten studies including 1819 participants were considered in this study. We found that positive LR, sensitivity, negative LR, specificity, and dOR of the CRP test for neonatal septicemia were 5.63 (95% CI=2.86 to 11.09), 0.70 (95% CI=0.66 to 0.75), 0.36 (95% CI=0.21 to 0.60), 0.89 (95% CI=0.87 to 0.91), and 17.99 (95% CI=6.50 to 49.83), respectively. The AUC and Q* index of this meta-analysis were 0.90 and 0.83, respectively. CONCLUSIONS The area under the curve (AUC), negative LR, positive LR, Q* index, specificity, and dOR of the CRP test suggest that it is appropriate for detecting neonatal septicemia.

C-reactive protein for diagnosing late-onset infection in newborn infants

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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.

The role of nCD64 in the diagnosis of neonatal sepsis in preterm newborns

BACKGROUND

Diagnosing neonatal sepsis is difficult, particularly in preterm newborns. A promising method appears to be evaluation of cell surface markers by flow cytometry.

METHODS

This prospective study investigated 217 newborns suspected of having early- or late-onset neonatal sepsis. In all, flow cytometry was used to determine the proportion of CD64-positive neutrophils (nCD64). Based on the clinical course and laboratory test results, newborns were categorized as having proven, possible, clinical or no neonatal sepsis. Subsequently, associations between the categories and nCD64 values were analyzed.

RESULTS

There were significant associations between nCD64 values and the development of sepsis in newborns with both early- or late-onset sepsis.

CONCLUSION

nCD64expression is significantly elevated in preterm newborn with early and late onset sepsis. The results show that nCD64 is a reliable marker for diagnosing neonatal sepsis.

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.

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 Role of Pancreatic Stone Protein in Diagnosis of Early Onset Neonatal Sepsis

Introduction. Early diagnosis and treatment of neonatal sepsis may help decrease neonatal mortality. Aim of the Study. To evaluate the role of pancreatic stone protein as a marker for early onset neonatal sepsis. Methods. A hospital-based prospective study was conducted on 104 (52 uninfected and 52 infected neonates) admitted to the Neonatal Intensive Care Unit (NICU) of Zagazig University hospitals during the period from April 2014 to April 2015. All newborns were subjected to full history taking, careful neonatal assessment, blood, C-reactive protein (CRP), and serum pancreatic stone protein. Results. Serum PSP levels were significantly higher in the infected group than in the uninfected group. At a cutoff level of PSP 12.96 ng/mL, the sensitivity was 96.2%, the specificity was 88.5%, positive predictive value was 95.8%, negative predictive value was 89.3%, and area under the curve was 0.87. A significant positive correlation between CRP and PSP was found in infected group. Conclusion. The high negative predictive value of PSP (89.3%) indicates that the serum PSP level is a good marker for diagnosis of early onset neonatal sepsis and can be used to limit hospital stay and antibiotic use in neonates treated for suspected sepsis.

Early detection of neonatal group B streptococcus sepsis and the possible diagnostic utility of IL-6, IL-8, and CD11b in a human umbilical cord blood in vitro model

Background

Group B streptococcus (GBS) infection remains a major cause of neonatal morbidity and mortality, and GBS III is the predominant strain in early-onset GBS neonatal sepsis. To avoid both over- and undertreatment of infants with nonspecific signs of infection, early diagnostic tools are warranted. The aim of this study was to identify biomarkers with high sensitivity and specificity in an early stage of GBS infection. A secondary aim was to assess the utility of a human umbilical cord blood (HUCB) model system of early-onset neonatal sepsis.

Methods

Umbilical cord blood samples from 20 healthy term pregnancies were stimulated for 2 hours with a GBS III isolate from a patient and a commercially available GBS Ia strain. Nonstimulated samples served as controls. Leukocyte surface markers (CD11b, CD64, toll-like receptor [TLR] 2, TLR4, and TLR6) were analyzed by flow cytometry and soluble biomarkers by enzyme-linked immunosorbent assay (interleukin [IL]-6 and -8; interferon-γ-inducing protein [IP]-10; and S100b). The area under the receiver operating characteristic curve (AUC) was calculated for the markers.

Results

GBS III gave the highest responses and AUC values for all biomarkers. Only IL-6 and IL-8 displayed an AUC approaching 0.8 for both GBS serotypes (P<0.001). IL-8 >5,292 pg/mL had both a sensitivity and a specificity of 1.00. IL-6 >197 pg/mL had both a sensitivity and a specificity of 0.95 for GBS III stimulation. CD11b on granulocytes and monocytes was the leukocyte surface marker with the highest AUC values for both GBS serotypes.

Conclusion

In agreement with previous studies, IL-6, IL-8, and potentially CD11b could be useful in diagnosing neonatal GBS infection in an early stage. Our HUCB early-onset neonatal sepsis model may be useful for evaluating biomarkers of neonatal sepsis. The HUCB of neonates with risk factors for sepsis might even be used for diagnostic purposes, but requires further study.

Meta-analysis of diagnostic accuracy of neutrophil CD64 for neonatal sepsis

Background

The aim of this study was to systematically evaluate the diagnostic performance of nCD64 for neonatal sepsis.

Methods

Computer retrieval was conducted for the databases of PubMed, Embase, and Springer databases up to March 18, 2015 to select the relevant studies on nCD64 and neonatal sepsis. Sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and 95 % confidence intervals (CI) for diagnostic efficiency of nCD64 were pooled. In addition, the summary receiver operating characteristic (SROC) curve was also conducted based on the sensitivity and specificity.

Results

Seventeen studies including 3478 participants were included in this meta-analysis. The overall pooled sensitivity, specificity, PLR, NLR and DOR were 0.77 (95 % CI: 0.74–0.79), 0.74 (95 % CI: 0.72–0.75), 3.58 (95 % CI: 2.85–4.49), 0.29 (95 % CI: 0.22–0.37) and 15.18 (95 % CI: 9.75–23.62), respectively. In addition, the area under the SROC curve (AUC) was 0.8666, and no threshold effect was found based on the Spearman correlation analysis (P = 0.616). Besides, subgroup analysis showed higher sensitivity, specificity and AUC in term infants and proven infection group than those in preterm infants and clinical infection group, respectively.

Conclusions

The n CD64 expression alone is not a satisfactory marker for diagnosing neonatal sepsis with relatively low sensitivity, specificity, PLR and NLR, in spite of relatively high SROC area. Therefore, the n CD64 expression used in diagnosis of neonatal sepsis should be treated with caution.

Which biomarkers reveal neonatal sepsis?

We address the identification of optimal biomarkers for the rapid diagnosis of neonatal sepsis. We employ both canonical correlation analysis (CCA) and sparse support vector machine (SSVM) classifiers to select the best subset of biomarkers from a large hematological data set collected from infants with suspected sepsis from Yale-New Haven Hospital's Neonatal Intensive Care Unit (NICU). CCA is used to select sets of biomarkers of increasing size that are most highly correlated with infection. The effectiveness of these biomarkers is then validated by constructing a sparse support vector machine diagnostic classifier. We find that the following set of five biomarkers capture the essential diagnostic information (in order of importance): Bands, Platelets, neutrophil CD64, White Blood Cells, and Segs. Further, the diagnostic performance of the optimal set of biomarkers is significantly higher than that of isolated individual biomarkers. These results suggest an enhanced sepsis scoring system for neonatal sepsis that includes these five biomarkers. We demonstrate the robustness of our analysis by comparing CCA with the Forward Selection method and SSVM with LASSO Logistic Regression.

Diagnostic accuracy of neutrophil CD64 expression in neonatal infection: A meta-analysis

Objective

*Liu-Qun Jia and Yong-Chun Shen contributed equally to this work and are joint first authors. The aim of the present study was to establish the predictive values of neutrophil CD64 expression in diagnosing neonatal infection.

Methods

A comprehensive search of the PubMed and Embase® literature databases identified outcome data from published studies estimating the diagnostic accuracy of neutrophil CD64 expression for neonatal infection. Summary estimates for sensitivity, specificity, diagnostic odds ratios (DOR) and the area under the summary receiver operating characteristic curve (AUC) were calculated using a bivariate random-effects approach.

Results

Twelve studies including 1915 neonates were analysed. Summary estimates (95% confidence intervals) for CD64 expression in the diagnosis of neonatal infection were: sensitivity, 0.78 (0.75, 0.81); specificity, 0.81 (0.78, 0.83); DOR, 21.27 (11.71, 38.65); positive-likelihood ratio, 4.53 (3.22, 6.36); negative-likelihood ratio, 0.23 (0.14, 0.37); AUC, 0.89.

Conclusions

Neutrophil CD64 expression can be used as an additional test in the diagnosis of neonatal infection. Results of a CD64 assay should not be used alone to diagnose such infections, but should be interpreted in combination with other test results and clinical findings.

Flow cytometry in the detection of neonatal sepsis

Neonatal sepsis remains a burden problem by showing minimal initial symptoms of subtle character, nonspecific manifestation, and diagnostic pitfalls. The clinical course can be fulminant and fatal if treatment is not commenced promptly. It is therefore crucial to establish early diagnosis and initiate adequate therapy. Besides clinical symptoms, the most reliable laboratory markers in establishing diagnosis is currently the combined measurement of CRP and a cytokine (IL-6 and IL-8). Due to their different kinetics, a diagnostic gap might occur and thus withholding antimicrobial therapy in clinical suspicion of infection is not acceptable. We therefore need parameters which unerringly differentiate between infants in need for antimicrobial therapy and those who are not. Flow cytometry promises to be a useful tool in this field, allowing the determination of different cellular, dissolved, and functional pathophysiological components of sepsis. Despite technical and methodical advances in flow cytometry, its use in clinical routine is still limited. Advantages and disadvantages of promising new parameters in diagnosis of sepsis performed by flow cytometry, particularly CD64, HLA-DR, and apoptosis, are reviewed here. The necessity of tests to be used as an “ideal” parameter is presented.

Neutrophil CD64 expression as a biomarker in the early diagnosis of bacterial infection: a meta-analysis

BACKGROUND

Neutrophil CD64 expression is widely reported as an efficacious biomarker to differentiate infected patients from other non-infected patients. This meta-analysis was conducted to comprehensively and quantitatively summarize the accuracy of neutrophil CD64 in the early diagnosis of bacterial infection.

METHODS

A systematic review of related studies was conducted, and the sensitivity, specificity, and other data about the accuracy of CD64 expression on neutrophils were pooled using random effects models with 95% confidence intervals (CI) as the effect measurements. Summary receiver operating characteristic (SROC) curves and the Q* value were also calculated in the meta-analysis. Heterogeneity was tested, as well as the publication bias. Potential sources of heterogeneity were explored by assessing whether or not certain covariates significantly influenced the summary diagnostic odds ratio (SDOR).

RESULTS

A total of 26 studies including 3944 patients met the inclusion criteria for the final analysis. The summary estimate was 0.76 (95% CI 0.74-0.78) for sensitivity and 0.85 (95% CI 0.83-0.86) for specificity. The positive likelihood ratio (PLR), negative likelihood ratio (NLR), SDOR, and area under the SROC of neutrophil CD64 expression with Q* value were 6.67 (95% CI 4.67-9.53), 0.24 (95% CI 0.18-0.31), 34.29 (95% CI 19.59-60.01), and 0.92 (Q*=0.85), respectively. The pooled data from the included studies had high heterogeneity and the Egger test suggested a publication bias.

CONCLUSIONS

On the basis of our meta-analysis, neutrophil CD64 expression could be a promising and meaningful biomarker for diagnosing bacterial infection. Nevertheless, more large prospective studies should be carried out before the neutrophil CD64 test is used widely in the clinical setting because of the various cut-off values.