Diagnostic Accuracy of Biomarkers for Early-Onset Neonatal Bacterial Infections: Evaluation of Serum Procalcitonin Reference Curves

Reliability of measuring serum C-reactive protein or procalcitonin with Rochester criteria in febrile neonates aged 8-28 days

OBJECTIVES

To investigate the utility of measuring serum C-reactive protein (CRP) or procalcitonin (PCT) level in conjunction with the Rochester criteria to exclude invasive bacterial infection (IBI) and urinary tract infection (UTI) in neonates aged 8-28 days with fever without an identifiable source of infection (FWSI).

METHODS

The medical records of all neonates aged 8-28 days with FWSI presenting to our pediatric emergency department between January 2018 and December 2022 were analyzed retrospectively. Only those who underwent workup based on the Rochester criteria with the serum biomarkers were included. Our findings were validated in a separate cohort in 2023.

RESULTS

In total, 191 neonates were included in the study, 54 (28.27 %) of whom had IBI and/or UTI. Serum biomarkers were analyzed, and higher CRP (p < 0.001) and PCT (p = 0.013) levels were found to be associated with IBI and UTI on multivariate logistic regression analysis. To exclude IBI and UTI, combining the Rochester criteria with a PCT < 0.5 ng/mL (Chang Gung criteria) had a higher negative predictive value (NPV) of 100.00 % than the Rochester criteria alone (93.06 %) and a similar positive predictive value (40.60 % and 41.18 %, respectively). Chang Gung criteria was validated in a cohort of 42 neonates aged 8-28 days with FWSI in 2023.

CONCLUSION

Using PCT at a threshold of 0.5 ng/mL alongside the Rochester criteria (Chang Gung criteria) provides a higher NPV for excluding IBI and UTI in neonates aged 8-28 days with FWSI.

Impact of Extended Membrane Rupture on Neonatal Inflammatory Responses and Composite Neonatal Outcomes in Early-Preterm Neonates-A Prospective Study

Background/Objectives: Prolonged prelabour rupture of membranes (PROMs), and the resulting inflammatory response, can contribute to the occurrence of adverse neonatal outcomes, especially for early-preterm neonates. This prospective study aimed to measure neonates' inflammatory markers in the first 72 h of life based on ROM duration. The second aim was to examine the relationship between PROMs, serum inflammatory markers, and composite adverse neonatal outcomes after controlling for gestational age (GA). Methods: Data from 1026 patients were analyzed considering the following groups: group 1 (ROM < 18 h, n = 447 patients) and group 2 (ROM > 18 h, n = 579 patients). These groups were further segregated depending on the GA at the moment of membranes' rupture into subgroup 1 (<33 weeks of gestation and 6 days, n = 168 patients) and subgroup 2 (at least 34 completed weeks of gestation, n = 858 patients). Multiple logistic regressions and interaction analyses adjusted for GA considering five composite adverse neonatal outcomes and predictors were employed. Results: PROMs and high c-reactive protein (CRP) values significantly increased the risk of composite outcome 1 occurrence by 14% (95%CI: 1.03-1.57, p < 0.001). PROMs and high CRP values increased the risk of composite outcome 5 by 14% (95%CI: 1.07-1.78, p < 0.001), PROM and leukocytosis by 11% (95%CI: 1.02-1.59, p = 0.001), and PROMs and high PCT values by 21% (95%CI: 1.04-2.10, p < 0.001). Conclusions: The combination of PROMs and high CRP values significantly increased the risk of all evaluated adverse composite outcomes in early-preterm neonates and should point to careful monitoring of these patients.

Procalcitonin-Based Antibiotic Use for Neonatal Early-Onset Bacterial Infections: Pre- and Post-Intervention Clinical Study

We previously reported the 95th percentile cutoff value of the serum procalcitonin (PCT) reference curve for diagnosing early-onset bacterial infection. We aimed to verify the effectivity of these novel diagnostic criteria by comparing antibiotic use and incidence of early-onset bacterial infection between pre- and post-introduction periods. We included newborns admitted to our neonatal intensive care unit who underwent blood tests within 72 h after birth between 2018 and 2022. The neonates were divided into the pre-intervention (admitted before the introduction, n = 737) or post-intervention (admitted after the introduction, n = 686) group. The days of antibiotics therapy (DOT) per 1000 patient days up to 6 days after birth, percentage of antibiotic use, and incidence of early-onset bacterial infection were compared between the groups. The post-intervention group had significantly lower DOT per 1000 patient days (82.0 days vs. 211.3 days, p < 0.01) and percentage of newborns receiving antibiotics compared with the pre-intervention group (79 (12%) vs. 280 (38%), respectively, p < 0.01). The incidence of early-onset bacterial infections did not differ between the groups (2% each, p = 0.99). In conclusion, our diagnostic criteria using the 95th percentile cutoff value of the serum PCT reference curve for early-onset bacterial infection were proven safe and effective, promoting appropriate use of antibiotics.

Pattern of Inflammatory Markers and Use of Antibiotics in Meconium Aspiration Syndrome: A Retrospective Cohort Study

Objectives To study the pattern of inflammatory markers in meconium aspiration syndrome (MAS) and their correlation with illness severity/antibiotic usage. Study design This is a retrospective analysis of neonates who were admitted with MAS and had inflammatory markers done during the first week of life. Results Seventy-six neonates with MAS were identified. White cell count (WCC), absolute neutrophil count (ANC), and immature to total neutrophil count (I/T) ratio peaked at 12 and CRP (43.75 mg/dl) at 48 hours of life (HOL). Neonates needing nasal cannula oxygen had lower CRP at 12 (p=0.035) and 24 HOL (p=0.046). There was no correlation between CRP at 48 HOL and score for neonatal acute physiology and perinatal extension II (SNAPPE-II; R2 0.0004). High CRP at 24 HOL was associated with longer duration of antibiotics (p<0.001) despite no correlation with the blood cultures. Conclusion MAS was associated with inflammatory markers peaking at 12 to 48 HOL; however, antibiotics should not be determined based on them as their correlation for illness severity or blood culture is poor.

Assessing Biomarkers in Viral Infection

Current biomarkers to assess the risk of complications of both acute and chronic viral infection are suboptimal. Prevalent viral infections like human immunodeficiency virus (HIV), hepatitis B and C virus, herpes viruses, and, more recently, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may be associated with significant sequelae including the risk of cardiovascular disease, other end-organ diseases, and malignancies. This review considers some biomarkers which have been investigated in diagnosis and prognosis of key viral infections including inflammatory cytokines, markers of endothelial dysfunction and activation and coagulation, and the role that more conventional diagnostic markers, such as C-reactive protein and procalcitonin, can play in predicting these secondary complications, as markers of severity and to distinguish viral and bacterial infection. Although many of these are still only available in the research setting, these markers show promise for incorporation in diagnostic algorithms which may assist to predict adverse outcomes and to guide therapy.

Obstetric Risk Factors and Serological Characteristics of Early-Onset Neonates Bacterial Infections

Purpose

To analyze the obstetric high-risk factors and serological characteristics of early-onset neonatal bacterial infections (EONBI).

Methods

119 neonates with early-onset bacterial infection who were admitted to the neonatal ward of our hospital from October 2020 to December 2021 were recorded as the study group, and 100 neonates without bacterial infection who were admitted during the same period were used as the reference group. Comparative analysis of obstetric high-risk factors and serological characteristics of EONBI.

Results

There was no statistical difference between the two groups in terms of gender and age at admission (P > 0.05). The gestational age and birth weight of newborns in the study group were lower than those in the reference group (P < 0.001). Comparing the maternal factors of EONBI between the two groups, there was no statistical difference in age, number of obstetric inspections, whether to use antibiotics, and mode of delivery (P > 0.05). Univariate analysis showed that preterm birth, unexplained asphyxia, fecal contamination of amniotic fluid, maternal infection during pregnancy, and premature rupture of membranes ≥18 h were significantly associated with EONBI (P < 0.05); while there was no significant difference between the two groups in the comparison between diabetic mother and child and maternal fever at delivery (P > 0.05). Multifactorial analysis showed that preterm birth, fecal contamination of amniotic fluid, maternal infection during pregnancy, and premature rupture of membranes ≥18 h had a good multivariate dependence on EONBI (P < 0.05), while there was no significant association with unexplained asphyxia, diabetic mother and child, and maternal fever at delivery (P > 0.05). The incidence of neonatal temperature >37.9°C was higher in the study group than in the reference group (P < 0.05), and there were no statistical differences in the comparison of other clinical manifestations (P > 0.05). The CRP level of neonates in the study group (47.33 ± 4.14) mg/L was higher than that of the reference group (4.84 ± 1.03) mg/L (P < 0.001). The WBC level of neonates in the study group (5.64 ± 1.18) 10⁹/L was higher than that of the reference group (0.28 ± 0.04) 10⁹/L (P < 0.001). The PCT level of neonates in the study group (5.41 ± 0.85) µg/L was higher than that of the reference group (0.24 ± 0.07) µg/L (P < 0.001).

Conclusion

EONBI is closely associated with several obstetric high-risk factors, including preterm birth, fecal contamination of amniotic fluid, maternal infection during pregnancy, and premature rupture of membranes ≥18 h; EONBI has no specific symptoms and signs, but serum CRP, WBC, and PCT levels are significantly higher than those of newborns without co-infection with bacteria.

Value of red cell distribution width-to-platelet ratio as a predictor for morbidity and mortality in neonatal intensive care unit

Scoring neonatal acute physiology is significant for improving the survival rate of neonates in neonatal intensive care units (NICU). Red blood cell distribution width to platelet ratio (RPR) has been used to evaluate physiology of multiple diseases. However, the value of RPR as a predictor for morbidity and mortality in NICU remains unclear. The score for neonatal acute physiology and perinatal extension II (SNAPE-II) was used to evaluate the physiology and separate neonates into Mild (n = 45), Moderate (n = 45) and Severe (n = 45) groups. White blood cell count (WBC), procalcitonin (PCT) and C-reactive protein (CRP) in cord blood were examine. Spearman’s correlation and receiver operating characteristic analysis were performed to demonstrated the correlations of these indicators. There was a positive correlation between the SNAPE-II scores and RPR in neonates in NICU. The WBC, PCT and CRP levels increased with the upregulation of SNAPE-II scores in neonates in NICU and there were positive correlations between RPR and WBC, PCT and CRP, respectively. RPR could be used as a supplementary predictor for the evaluation of neonatal morbidity and mortality in NICU beside SNAPE-II.

The Diagnostic Value of Fe3+ and Inflammation Indicators in the Death of Sepsis Patients: A Retrospective Study of 428 Patients

Background

Studies have shown that a variety of blood inflammatory markers can be used to assess the criticality of patients with sepsis. In this study, the blood inflammatory factors related to the sepsis survival group and the death group were compared and analyzed, which can be used by clinicians to adjust sepsis patient treatment.

Methods

This study used retrospective methods to analyze the medical records of 428 patients with sepsis. The test of blood samples includes the patient's age, gender, hospital stays, the concentration of procalcitonin (PCT), absolute neutrophil count (ANC), absolute lymphocyte count (ALC), neutrophil-to-lymphocyte ratio (NLR), D-dimer (DD), Fe³⁺, and hemoglobin (Hb) in the venous blood of patients with sepsis. The detection of PCT methods adopts the sandwich immunofluorescence (IF). ROC curve was used for the diagnosis and analysis of various factors of sepsis.

Results

Among all the patients with sepsis, 133 patients died, with a mortality rate of 31.07%. Analysis of related inflammatory indicators and the patient's baseline parameters showed the patients age, the values of PCT, ANC, NLR, and DD in death group were statistically higher than those in survival group (all p values were <0.05). However, the concentration of Fe³⁺ and ALC show an opposite trend between the two groups. Regression analysis results showed the patient's gender, Fe³⁺, PCT, ANC, and DD are all independent prognostic factors for patients with sepsis. The results of the ROC curve of related diagnostic indicators show that DD has the best area under curve (AUC=0.700), the most sensitive index is ANC (74.44), and the most specific index is PCT (89.80). The results of the two-by-two combined diagnosis of the four indicators showed that the PCT+DD group had better AUC (0.748) and specificity (78.23), and the Fe³⁺+DD group had the best sensitivity (75.89).

Conclusion

In this study, the patient's gender and the inflammation-related markers of Fe³⁺, PCT, ANC, and DD can be used as independent risk factors affecting the prognosis of patients with sepsis. The combination of PCT+DD and Fe³⁺+DD has high diagnostic value for patients with sepsis.