Procalcitonin and C-reactive protein levels in neonatal infections

Clinical Utility of Procalcitonin and C-Reactive Protein in the Management of Neonatal Sepsis in a Resource-Limited Nigerian Hospital

BACKGROUND

Neonatal sepsis is an invasive infection of the bloodstream in neonates and a leading cause of morbidity and mortality among them.

AIM

To investigate the role of procalcitonin (PCT) and C-reactive protein (CRP) in the management of neonatal sepsis.

MATERIALS AND METHODS

This was a prospective case-control study over one-year period using convenience sampling. Blood samples for PCT and CRP were taken from all neonates, while blood culture and white blood cell count samples were additionally taken from babies with neonatal sepsis. PCT and CRP were repeated at 24 and 48 hours. The continuous variables were found to have a nonparametric distribution. They were presented as median and interquartile range, and compared using Wilcoxon signed rank and Friedman test as appropriate.

RESULTS

The blood culture analysis yielded a prevalence of 12.7% with Staphylococcus aureus being the commonest organism. Baseline concentrations of PCT (1.28 ng/ml) and CRP (17.31 mg/L) in neonates with sepsis were higher than that of controls (PCT-0.63 ng/ml, CRP-5.40 mg/L). PCT concentrations decreased after two days of antibiotic treatment, while CRP concentrations decreased after a day. The concentration of both decreased to normal levels after two days of treatment.

CONCLUSION

This study showed that CRP was more reliable in monitoring antibiotic therapy, unlike other studies which suggested PCT. In cases where the management of neonatal sepsis may be limited by a low blood culture yield, therapeutic monitoring may be aided by CRP and/or PCT.

Risk factors and predictive markers for early and late-onset neonatal bacteremic sepsis in preterm and term infants

BACKGROUND

The early detection and prediction of bacteremic sepsis in preterm and term neonates remains a challenging task because of their nonspecific clinical presentations. We aimed to investigate the risk factors associated with bacteremia and find the cutoff values of predictive markers to achieve accurate diagnosis of neonatal bacteremic sepsis.

METHODS

Not-doing-well preterm and term neonates with suspected sepsis were retrospectively enrolled between January 2015 and December 2017 in Taipei Veterans General Hospital. Blood culture, hemogram, serum procalcitonin (PCT), and C-reactive protein (CRP) were drawn at the onset of clinical signs and symptoms. All cases were divided to either early-onset or late-onset groups according to postpartum age. Nonparametric statistic, logistic regression, and receiver operating characteristic analysis were performed to evaluate the risk factors and cutoff values for predicting bacteremia.

RESULTS

A total of 169 suspected sepsis episodes were analyzed, 68.0% of which had cardiopulmonary dysfunction and 19.5% had perinatal stress. The early-onset group had 123 (72.8%) patients, 4 of which had bacteremia and 119 had nonbacteremia conditions. The late-onset group had 46 (27.2%) patients, 8 of which had bacteremia and 38 had nonbacteremia conditions. Gestational age, birth body weight, Apgar score at 5 minutes, serum PCT, CRP, and platelet (PLT) count in the early-onset group and white blood cell (WBC) count in the late-onset group were substantially different between the patients with bacteremia and nonbacteremia conditions. PCT greater than 27 µg/L (adjusted odd ratio [aOR], 21.6; 95% CI, 1.1-435.1) and thrombocytopenia less than 100 × 109/L (aOR, 38.6; 95% CI, 1.4-1030.3) were predictive markers for bacteremia in the early-onset group.

CONCLUSION

Early- and late-onset neonatal sepsis had different risk factors and predictive markers of bacteremia. PCT and PLT count in the early-onset group and WBC count in the late-onset group were accurate diagnostic serum markers for neonatal bacteremic sepsis.

Procalcitonin in Preterm Neonates: A Different Threshold and Prolonged Interpretation

Objectives: To evaluate the positive threshold of PCT for neonates of <32 weeks of gestation for the diagnosis of early-onset sepsis and to determine if the level of PCT collected within 6 h of life could be used. Design: Retrospective and bicentric study from May 2016 to April 2018. Setting: Two groups were established, neonates evaluated for PCT at birth (CordPCT) and within 6 h of life (delPCT). Patients: Two hundred and sixty neonates of <32 weeks of gestation born in Nice and South Paris (Bicêtre) University Hospitals, had been evaluated for PCT level. Main Outcomes Measures: The value of the PCT positive threshold was determined for the total population and each groups thanks ROC curves. Results: The threshold level of PCT for the total population was 0.98 ng/mL. The threshold value of cordPCT group was 1.00 vs. 0.98 ng/mL for delPCT group. The area under the Receiver Operating Characteristics curve for PCT sampled in delPCT group was significantly higher than in cordPCT group (0.94 compared to 0.75). Conclusions: The threshold level of PCT was higher in this cohort of neonates of <32 weeks of gestation compared to the value generally described for term neonates. The secondary sampling PCT level seems to be usable in screening algorithm for early-onset neonatal sepsis.

Procalcitonin Level at 24 Hours of Age May be Predictive for Transient Tachypnea of the Newborn

Objective It is an important problem to differentiate transient tachypnea of the newborn (TTN) from bacterial pneumonia or other conditions in patients admitted to Neonatal Intensive Care Unit. The aim of this study was to evaluate the predictive value of procalcitonin (PCT) for TTN.

Methods A total of 52 infants were contained in the study. The patients were divided into three groups. Group 1 consisted of patients with pronounced grunting at more than 2 hours postnatal age (n = 16). Group 2 consisted of patients whose grunt was reduced or gone at 2 hours postnatal age but in whom tachypnea persisted until 24 hours postnatal age (n = 18). Group 3 consisted of patients with minimal or no respiratory distress at 24 hours postnatal age (n = 18). In all groups, PCT concentrations were determined at birth and 24 hours postnatal age.

Results PCT concentrations at birth were significantly higher in Group 1 than other groups, but there was no difference between Groups 2 and 3. PCT concentrations at 24 hours postnatal age were significantly higher in Groups 1 and 2 than Group 3. No difference was found between Group 1 and Group 2 at 24 hours postnatal age. All PCT concentrations in Group 3 were significantly lower than other groups. PCT thresholds for the diagnosis of TTN were 0.44 ng/mL at birth (sensitivity 58%, specificity 50%) and 5.11 ng/mL at 24 hours postnatal age (sensitivity 79.4%, specificity 89.1%).

Conclusion Serial PCT measurements at birth and postnatal 24 hours may be helpful in differentiating between pneumonia and TTN. Further researches are needed to confirm this initial study.

Recent advances in developing biosensing based platforms for neonatal sepsis

Neonatal sepsis is a bloodstream infection primarily caused by Escherichia coli (E. coli), Group B Streptococcus (GBS), Listeria monocytogenes, Haemophilus influenzae, S. aureus, Klebsiella spp. and non-typhoidal Salmonella bacteria. Neonatal Sepsis is referred as a critical response to the infection in the neonatal period that can lead to the failure of body organs and thereby causing damage to the tissues resulting in death of the neonates. Nearly 4 million deaths across the world are occurred due to neonatal sepsis infections. In order to prevent the bloodstream infections in the neonates, it is indispensable to diagnose the disease properly for appropriate treatment during the point of care. Numerous studies have been reported to identify major biomarkers associated with neonatal sepsis including Serum Amyloid A (SAA), C - reactive protein (CRP), Procalcitonin (PCT) and Lipopolysaccharide-binding protein (LBP). Distinct diagnostic platforms have also been developed detecting the presence of bloodstream infections including electrochemical, potentiometric, and impedimetric sensors. Recently, electrochemical biosensors with the integration of nanomaterials have emerged as a better platform for neonatal sepsis biomarkers detection. This review article summarizes the diverse screening platforms, evaluation parameters, and new advances based on implications of nanomaterials for the development of biosensors detecting neonatal sepsis infections. The review further elucidates the significance and future scope of distinctive platforms which are predominantly associated with detection of neonatal sepsis.

[Diagnostic value of procalcitonin in neonatal early-onset sepsis]

OBJECTIVE

To study the value of procalcitonin (PCT) within 3 days after birth in the diagnosis of neonatal early-onset sepsis (EOS), as well as the thresholds of PCT in the diagnosis of EOS in neonates with different gestational ages and different ages.

METHODS

A total of 109 neonates with a confirmed diagnosis of sepsis, 215 neonates with clinically diagnosed sepsis, and 367 neonates without sepsis were enrolled. Receiver operating characteristic (ROC) curves were plotted to determine the optimal cut-off values of PCT in the diagnosis of EOS in neonates with different gestational ages and different ages. The diagnostic value of PCT and blood culture was compared.

RESULTS

In the confirmed diagnosis group, the neonates with a gestational age of <34 weeks had a significantly higher level of PCT than those with a gestational age of ≥34 weeks (P<0.05). For the neonates with a gestational age of ≥34 weeks, the optimal cut-off values of PCT in the diagnosis of EOS were 1.588 ng/mL (sensitivity 0.688, specificity 0.851) at age of <12 hours, 4.960 ng/mL (sensitivity 0.737, specificity 0.883) at age of 12 - <24 hours, 5.583 ng/mL (sensitivity 0.727, specificity 0.865) at age of 24 - <36 hours, 1.710 ng/mL (sensitivity 0.732, specificity 0.755) at age of 36 - <48 hours, 3.570 ng/mL (sensitivity 0.488, specificity 0.930) at age of 48 -<60 hours, and 3.574 ng/mL (sensitivity 0.333, specificity 0.900) at age of 60 - 72 hours. PCT had a larger area under the ROC curve in the diagnosis of EOS than blood culture within 36 hours after birth (P<0.05).

CONCLUSIONS

The same criteria can be used for late preterm infants (with a gestational age of ≥34 weeks) and full-term infants, while early preterm infants (with a gestational age of <34 weeks) should be considered separately. PCT has different optimal cut-off values in the diagnosis of EOS in neonates with different ages, with a higher value than blood culture in the diagnosis of EOS within 36 hours after birth.

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.

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 levels among patients with fever secondary to severe intracerebral infection. A cross-sectional study

BACKGROUND

Making the differential diagnosis between central fever and infectious fever is critically important among intracerebral hemorrhage patients followed up in intensive care units (ICUs). Serum procalcitonin (PCT) has been found to be a promising biomarker for the initial diagnosis of infection, even before culturing results.

OBJECTIVES

To investigate the relationship between PCT and both fever etiologies and C-reactive protein (CRP) levels among critically ill patients with suspected intracerebral hemorrhage.

DESIGN AND SETTING

Cross-sectional study in a public university hospital in Elazig, Turkey.

METHODS

ICU patients diagnosed with intracerebral hemorrhage and normal procalcitonin levels were included in this study. From clinical assessments and cultures, they were classified as presenting either infectious or central fever. The sensitivity and specificity of PCT and CRP for predicting infection were calculated using a receiver operating characteristic (ROC) curve.

RESULTS

There were 98 ICU patients with diagnoses of intracerebral hemorrhage. The median (interquartile range) PCT levels of patients with infectious and central fever were 4 (0.9-11) and 0.1 (0.1-0.4) ng/ml, respectively, with a statistically significant intergroup difference (P < 0.001). The areas under the ROC curve for predicting infectious or central fever PCT and CRP were 0.958 (P < 0.001) and 0.816 (P < 0.001), respectively. A statistically significant positive correlation was detected between PCT and CRP levels in patients with infectious fever (rho: 0.461; P = 0.003), but not in patients with central fever.

CONCLUSIONS

PCT can possibly be used as a biomarker to differentiate between infectious and central fever among ICU patients.

Evaluation of procalcitonin as a diagnostic marker in neonatal sepsis

Context

Neonatal sepsis is an early infection occurring within 28 days of the postnatal life. It has nonspecific signs and symptoms which make the diagnosis cumbersome. It inflicts an increase in morbidity and mortality among neonates. Procalcitonin (PCT) is yet another acute phase reactant, which is synthesized by the C-cells of thyroid gland.

Aims

The aim of our study is to evaluate PCT as a diagnostic marker of neonatal sepsis in comparison with C-reactive protein (CRP).

Subjects and Methods

A prospective cross-sectional study was conducted at our tertiary care hospital in Puducherry. The study was conducted over a period of 5 months from November 2015 to 2016. The study included all neonates with clinical signs of sepsis. The neonates were assigned into three groups as proven sepsis, suspected sepsis, and no sepsis group. The CRP level and PCT level were compared between the three groups, and their sensitivity and specificity were calculated.

Statistical Analysis Used

The mean, standard deviation, and standard error of mean were calculated. The groups were compared using one-way ANOVA. The diagnostic test efficiency was evaluated by receiver operating characteristic curve analysis.

Results

A total of 75 neonates were included in our study. There were 9 (12%) neonates with proven clinical sepsis, 47 (62.6%) neonates with suspected clinical sepsis, and 19 (25.3%) neonates with no sepsis. The mean and standard error of mean were calculated for CRP and PCT in all the three groups. The results showed a sensitivity of 88.90% for both CRP and PCT and specificity of 89.40% for CRP and 80.30% for PCT. The common organisms isolated from culture-positive group were Escherichia coli (22.2%), Pseudomonas aeruginosa (22.2%), and Candida albicans (22.2%), followed by Klebsiella pneumoniae, Acinetobacter baumannii, and methicillin-resistant Staphylococcus aureus.

Conclusions

PCT may not be sufficiently used as a sole marker of sepsis in neonates compared to CRP. PCT in conjunction with CRP and other tests for septic screen can aid in better diagnosis of neonatal sepsis.

Comparison of Four Days Versus Seven Days Duration of Antibiotic Therapy for Neonatal Pneumonia: A Randomized Controlled Trial

OBJECTIVE

To compare the effect of 4 day course (study group) with 7 day course (control group) of antibiotic treatment in neonatal pneumonia, on treatment success rate.

METHODS

This randomized controlled trial was conducted in a tertiary teaching hospital. Seventy, term and near-term neonates with pneumonia who had clinical remission by 48 h of antibiotic therapy were included. The neonates were randomized to receive a total of 4 d of antibiotics (Group 1) or 7 d of antibiotics (Group 2). The outcome measure was treatment failure in each group within 3 d of discharge.

RESULTS

The treatment success rate of both the groups was 100%. There was a significant reduction in the duration of hospital stay (p < 0.001), antibiotic usage (p < 0.001), and cost (p < 0.001) in the 4 d group. On follow up till 28 d of enrollment, no infective morbidity was found in either group.

CONCLUSIONS

For term and near-term neonates who become clinically asymptomatic within 48 h of antibiotic therapy, 4 d of antibiotic therapy is as effective and safe as 7 d of antibiotic therapy, with significant reduction in hospital stay, antibiotic usage and cost.

Is Procalcitonin Useful in Pediatric Critical Care Patients?

This review examines the use of procalcitonin in different clinical situations in the pediatric patient, with special emphasis on those requiring intensive care. We review the latest articles on its potency as a biomarker in both infectious processes at diagnosis and on the response to treatment.

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: The marker of pediatric bacterial infection

Timely recognition of systemic bacterial infections in pediatric care setting is the basis for effective treatment and control. This review provides an overview of procalcitonin (PCT) as an early marker for the detection of severe, invasive bacterial infection in children. Almost all articles on biochemical property and clinical studies in PubMed and Scopus databases regarding their use in pediatric infections and the use of PCT as a marker of bacterial infections were examined. Various methods and analyzers are currently available for the evaluation of PCT. Employment of PCT in the identification of neonatal bacterial infection is a complex process in some conditions. Age specific cut-off, underlying syndrome, and maternal antibiotics usage should be considered when PCT is to be applied in neonates. PCT might be false-negative in these conditions. However, if used appropriately, it can lead to a higher specificity than other immunologic markers. Due to its correlation with the severity of infection, PCT can consequently be used as a prognostic indicator especially for sepsis and urinary tract infection. It is, therefore, a practical supplementary means for the identification of bacterial infections in pediatric health settings.

Double-Edged Sword: Musculoskeletal Infection Provoked Acute Phase Response in Children

The acute phase response has a crucial role in mounting the body's response to tissue injury. Excessive activation of the acute phase response is responsible for many complications that occur in orthopedic patients. Given that infection may be considered continuous tissue injury that persistently activates the acute phase response, children with musculoskeletal infections are at markedly increased risk for serious complications. Future strategies that modulate the acute phase response have the potential to improve treatment and prevent complications associated with musculoskeletal infection.

Antimicrobial Stewardship in the Management of Sepsis

Sepsis represents a unique clinical dilemma with regard to antimicrobial stewardship. The standard approach to suspected sepsis in the emergency department centers on fluid resuscitation and timely broad-spectrum antimicrobials. The lack of gold standard diagnostics and evolving definitions for sepsis introduce a significant degree of diagnostic uncertainty that may raise the potential for inappropriate antimicrobial prescribing. Intervention bundles that combine traditional quality improvement strategies with emerging electronic health record-based clinical decision support tools and rapid molecular diagnostics represent the most promising approach to enhancing antimicrobial stewardship in the management of suspected sepsis in the emergency department.

Utility of cytokine, adhesion molecule and acute phase proteins in early diagnosis of neonatal sepsis

Background and Aim:

Neonatal infection, including bacterial sepsis, is a major health care issue with an annual global mortality in excess of one million lives. Therefore, this study aimed to evaluate the potential diagnostic value of C-reactive protein (CRP), E-selectin, procalcitonin (PCT), interleukins-6 (IL-6), and tumor necrosis factor-α (TNF-α) both independently and in combination for the diagnosis of neonatal sepsis in its earliest stages.

Materials and Methods:

A total of 320 subjects were included in this study. A prospective cross-sectional study was conducted among neonates admitted to Neonatal Intensive Care Unit at King Abdulaziz Medical City, Riyadh, KSA during January 2013 to August 2015, the study based on three study groups categorized according to clinical symptoms and blood culture result. Study groups include healthy control neonates (n = 80), clinical sepsis (CS) group (n = 80) with clinical signs of sepsis but their blood culture was negative, and sepsis group with clinical signs of sepsis and their blood culture was positive.

Results:

The study observed significant difference in plasma levels of CRP, IL-6, TNF-α, E-selectin, and PCT in patients group when compared with control group (P < 0.001). Furthermore, the levels are significantly different between patient groups including CS and neonatal sepsis group. Moreover, result observed significant difference in CRP and IL-6 in early onset sepsis (EOS) when compared with late onset sepsis (LOS) neonates (P < 0.001 and 0.01), respectively, while there were no significant difference in TNF-α, E-selectin, and PCT between EOS and LOS (P = 0.44, 0.27 and 0.24), respectively. Regarding biomarkers accuracy, the result showed that CRP has the best diagnostic accuracy with cutoff value of 3.6 ng/ml (sensitivity 78% and specificity of 70%). The best combination is shown with CRP and IL-6 in which sensitivity increased to 89% and specificity to 79%.

Conclusion:

It was concluded that infected new-born babies have a higher E-selectin, PCT, IL-6, TNF-α, and CRP compared with the neonates with CS and control. IL-6, TNF-α, and CRP should be measured in combination for mare diagnostic accuracy in neonatal sepsis. Likewise, PCT should be investigated as a part of sepsis screening for all suspected neonates.

Neutrophil CD64 combined with PCT, CRP and WBC improves the sensitivity for the early diagnosis of neonatal sepsis

BACKGROUND

The aim of this study was to determine whether neutrophil CD64 (nCD64) combined with procalcitonin (PCT), C-reactive protein (CRP) and white blood cell count (WBC) can increase the sensitivity and accuracy of neonatal sepsis diagnosis.

METHODS

The serum levels of nCD64, CRP, PCT and WBC were detected in 60 patients with neonatal sepsis and 60 patients with non-sepsis. Sensitivity, specificity, positive and negative predictive values, receiver operating characteristic (ROC) area under the curve (AUC), and logistic regression analysis were performed to evaluate the diagnostic value of these markers on neonatal sepsis.

RESULTS

Serum levels of nCD64, PCT, CRP and WBC were higher in the sepsis group than non-sepsis group (p<0.001). The sensitivities of nCD64, PCT, CRP and WBC at the recommended cut-off level for all infants were 79.5%, 68.2%, 38.6% and 52.3%, respectively. The best combination was nCD64 and PCT, which obtained sensitivity of 90.9%, largest AUC of 0.922, and a negative predictive value of 89.2%. However by using an optimal cut-off value, the sensitivities of all four biomarkers for the diagnosis of neonatal sepsis were increased to 95.5%. Except for WBC, the birth weight and gestational age had no effects on the diagnostic value of these serum biomarkers.

CONCLUSIONS

nCD64 and PCT are better diagnostic biomarkers for early diagnosis of neonatal sepsis as compared to CRP. With the help of optimal cut-off value based on ROC curve and logistic regression analysis, the combination of these biomarkers could improve the sensitivity for the diagnosis of suspected late-onset neonatal sepsis based on common serum biomarkers.

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.

Amalgamation of procalcitonin, C-reactive protein, and sequential organ failure scoring system in predicting sepsis survival

Background:

The clinical value of inflammatory biomarkers is still questionable.

Aim of the Work:

The aim of this study is to compare the clinical informative value of procalcitonin (PCT) and C-reactive protein (CRP) plasma concentration in the early detection of sepsis, as well as relating these biomarkers to other scoring systems.

Patients and Methods:

A total of 138 patients were enrolled in our study. All were subjected to PCT, CRP, and sequential organ failure assessment (SOFA) scores daily for 7 days (starting from admission day). Blood samples were collected before starting antibiotics, with 28 days follow-up and patients were assigned to three groups: Group I: SOFA 2-7, Group II: SOFA 8-10, and Group III: SOFA ≥11.

Results:

Underlying clinical diagnosis revealed pneumonia in 72 patients, urinary tract infections in eight, bloodstream infection in four, and other infections in 23, while infection could not be traced in 25 patients. The mean PCT was 3 ng/ml (95% confidence interval [CI]: 1-4), 12 ng/ml (95% CI: 9.1-14), and 19 ng/ml (95% CI: 16.3-22.3) in Groups I, II, and III, respectively, with a statistically significant difference in the mean PCT level among the three groups (P < 0.0001). On the other hand, CRP mean level did not significantly differentiate between the groups (147.1 mg/L in Group II, which was even higher than the level of Group III, 138.4 mg/L).

Conclusion:

PCT seems to do better than CRP in predicting the SOFA groups, giving its patronage display over a wide spectrum of insults.

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.

Neutrophil CD64 as a diagnostic marker of sepsis: impact on neonatal care

OBJECTIVE

The aim of this study is to determine the validity and reliability of neutrophil CD64 in identifying infected infants and to evaluate the impact of this marker on clinical care.

STUDY DESIGN

Neutrophil CD64 index was incorporated in 371 infection evaluations in 234 infants (ages 1-293 days) from 2005 to 2009 and the impact of this change on clinical care was evaluated.

RESULTS

The sensitivity of the neutrophil CD64 assay was 87% in identifying 31 episodes of culture positive sepsis and 83% in identifying 12 infants with ventilator-associated pneumonia. There was no difference in the mean number of antibiotic days in infants with a normal CD64 versus those with a normal complete blood count (CBC) (p = 0.89), but twofold more infants were identified as "not infected" by CD64 than by CBC.

CONCLUSION

CD64 had a high sensitivity for identifying infected infants while also decreasing the number of infants that were exposed to unnecessary antibiotic use.

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.

Serum procalcitonin as a diagnostic marker of neonatal sepsis

Purpose

We evaluated serum procalcitonin (PCT) as a diagnostic marker of neonatal sepsis, and compared PCT levels with C-reactive protein (CRP) levels.

Methods

We retrospectively reviewed the medical records of 269 neonates with a suspected infection, admitted to Wonkwang University School of Medicine & Hospital between January 2011 and December 2012, for whom PCT and CRP values had been obtained. Neonates were categorized into 4 groups according to infection severity. CRP and PCT values were analyzed and compared, and their effectiveness as diagnostic markers was determined by using receiver operating characteristic (ROC) curve analysis. We also calculated the sensitivity, specificity, and positive, and negative predictive values.

Results

The mean PCT and CRP concentrations were respectively 56.27±81.89 and 71.14±37.17 mg/L in the "confirmed sepsis" group; 15.64±32.64 and 39.23±41.41 mg/L in the "suspected sepsis" group; 9.49±4.30 and 0.97±1.16 mg/L in the "mild infection" group; and 0.21±0.12 and 0.72±0.7 mg/L in the control group. High concentrations indicated greater severity of infection (P<0.001). Five of 18 patients with confirmed sepsis had low PCT levels (<1.0 mg/L) despite high CRP levels. In the ROC analysis, the area under the curve was 0.951 for CRP and 0.803 for PCT. The cutoff concentrations of 0.5 mg/L for PCT and 1.0 mg/L for CRP were optimal for diagnosing neonatal sepsis (sensitivity, 88.29% vs. 100%; specificity, 58.17% vs. 85.66%; positive predictive value, 13.2% vs. 33.3%; negative predictive value, 98.6% vs. 100%, respectively).

Conclusion

PCT is a highly effective early diagnostic marker of neonatal infection. However, it may not be as reliable as CRP.

Procalcitonin better than C-reactive protein, erythrocyte sedimentation rate, and white blood cell count in predicting DNAemia in patients with sepsis

BACKGROUND

Procalcitonin (PCT) levels can be used to predict bacteremia and DNAemia in patients with sepsis. In this study, the diagnostic accuracy of PCT in predicting blood culture (BC) results and DNAemia, as detected by real-time PCR (RT-PCR), was compared with that of other markers of inflammation commonly evaluated in patients with suspected sepsis, such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and white blood cell (WBC) count.

METHODS

A total of 571 patients for whom BC, blood RT-PCR, PCT, CRP, ESR, and WBC count were requested for laboratory diagnosis of sepsis were included in the study. Receiver operating characteristic curve analysis was performed to compare the ability of the above biomarkers to predict BC and blood RT-PCR results.

RESULTS

A total of 108 pathogens were identified by BC (79 pathogens, 14.5% positive rate) and/or RT-PCR (90 pathogens, 16.5% positive rate), after exclusion of 26 contaminated samples. The PCT areas under the curve (AUCs) in predicting BC (0.843; 95% CI 0.796-0.890; p < 0.0001) and RT-PCR (0.916; 95% CI 0.888-0.945; p < 0.0001) results were significantly greater than AUCs found for CRP, ESR, and WBC count.

CONCLUSIONS

PCT showed a better diagnostic accuracy than CRP, ESR, and WBC count in predicting DNAemia and bacteremia in patients with suspected sepsis.

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.

Can resistin be a new indicator of neonatal sepsis?

BACKGROUND

Sepsis is an important cause of neonatal death and perinatal brain damage, particularly in preterm infants. It is thought that activation of the inflammatory cascade triggered by cytokine might play a role in the pathogenesis of sepsis. Recent evidence supports a role for resistin in inflammation. There are no data in the literature on resistin levels of premature newborns with sepsis, which can also cause inflammatory response. The objective of this study was to evaluate whether resistin can be used as an indicator in neonatal sepsis of preterm babies.

MATERIALS AND METHODS

Forty-three premature newborns considered to have sepsis were included in the study. Forty-three gestational and postnatal age- and sex-matched premature newborns without premature prolonged rupture of membrane or sepsis served as controls.

RESULTS

The median resistin and interleukin-6 (IL-6) levels of the premature babies with sepsis were 85.9 ng/mL and 342.7 pg/mL, respectively, and were higher than those of the control group (29.9 ng/mL and 17.7 pg/mL, respectively). The sensitivity, specificity, positive, and negative predictive values for resistin were 73.7%, 45.8%, 68.3%, and 52.4%, respectively.

CONCLUSION

Resistin levels were higher in premature newborns with sepsis and correlated with IL-6 levels, which is an indicator of neonatal sepsis. This suggests that resistin may also be used in the diagnosis of neonatal sepsis. However, it has limited value when compared with the other inflammatory markers including C-reactive protein, procalcitonin, and IL-6.

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.

The use of procalcitonin as a marker of sepsis in children

OBJECTIVE

Sepsis is a life-threatening disease which is associated with high rates of morbidity and mortality. The critically ill patients often manifest a Systemic Inflammatory Response Syndrome (SIRS) which is independent of an infection. The early diagnosis of different severities of sepsis is important for an early implementation of the specific therapies. Our objective was to evaluate the diagnostic and the prognostic values of blood Procalcitonin (PCT) in cases of bacterial septicaemia in children.

METHODS

The total sample comprised of 150 subjects who were admitted to the ICU with septicaemia and 50 normal, healthy, age and sex matched children. The first sample was collected at the time of admission, before the start of the antibiotic therapy (T0). A second sample was collected at 24 hours (T24) and a final sample was collected at 96 hours (T96). A PCT value of > 0.5ng/ml was accepted as positive.

RESULTS

63% of the children who were diagnosed with a bacterial aetiology showed detectable blood PCT levels with higher concentrations, while in the children who were diagnosed with a viral aetiology, only 22.2 % had detectable PCT levels, but in lower concentrations. The mean percentage reduction in the PCT value among the bacterial infection subjects was 44.39 ± 41.82 as compared to that in the viral infection subjects (5.71 ± 26.68) and in the subjects where the aetiology was not established (5.71 ± 26.68).

CONCLUSION

The results which were obtained in our study con- firmed that the PCT levels were a better marker for the bacterial infections. The PCT measurements may be used as a guide to the antibiotic therapy in critically ill children with suspected sepsis.

New approaches to sepsis: molecular diagnostics and biomarkers

Sepsis is among the most common causes of death in hospitals. It arises from the host response to infection. Currently, diagnosis relies on nonspecific physiological criteria and culture-based pathogen detection. This results in diagnostic uncertainty, therapeutic delays, the mis- and overuse of antibiotics, and the failure to identify patients who might benefit from immunomodulatory therapies. There is a need for new sepsis biomarkers that can aid in therapeutic decision making and add information about screening, diagnosis, risk stratification, and monitoring of the response to therapy. The host response involves hundreds of mediators and single molecules, many of which have been proposed as biomarkers. It is, however, unlikely that one single biomarker is able to satisfy all the needs and expectations for sepsis research and management. Among biomarkers that are measurable by assays approved for clinical use, procalcitonin (PCT) has shown some usefulness as an infection marker and for antibiotic stewardship. Other possible new approaches consist of molecular strategies to improve pathogen detection and molecular diagnostics and prognostics based on transcriptomic, proteomic, or metabolic profiling. Novel approaches to sepsis promise to transform sepsis from a physiologic syndrome into a group of distinct biochemical disorders and help in the development of better diagnostic tools and effective adjunctive sepsis therapies.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Serum procalcitonin in viral and bacterial meningitis

Background:

In children with meningitis, there is a difficulty to verify the etiology as viral or bacterial. Therefore, intensive research has been carried out to find new and rapid diagnostic methods for differentiating bacterial from viral meningitis.

Objectives:

The aim of this work was to study the behavior of procalcitonin (PCT) and whether it can be used to differentiate children with bacterial from those with viral meningitis. We also compared PCT to C-reactive protein (CRP) and white blood cell count.

Patients and Methods:

Forty children aged from 4 months to 12 years with clinically suspected meningitis were studied. Lumbar punctures were done for all cases before starting initial antibiotic treatment. According to the results of bacterial cultures and cerebrospinal fluid (CSF) cytochemical profile, our patients were classified into two groups: bacterial meningitis group and viral meningitis group. PCT, CRP, and leukocyte count were measured at the time of admission and after 3 days.

Methods:

Forty children aged from 4 months to 12 years with clinically suspected meningitis were studied. Lumbar punctures were done for all cases before starting initial antibiotic treatment. According to the results of bacterial cultures and cerebrospinal fluid (CSF) cytochemical profile, our patients were classified into two groups: bacterial meningitis group and viral meningitis group. PCT, CRP, and leukocyte count were measured at the time of admission and after 3 days.

Results:

PCT levels were significantly higher in patients with bacterial meningitis (mean, 24.8 ng/ml) compared to patients with viral meningitis (mean, 0.3 ng/ml) (P<0.001). PCT levels in bacterial meningitis group decreased after 3 days of starting treatment, but remained higher than viral meningitis group (mean, 10.5 ng/ml). All CSF parameters, blood leukocytes, and CRP showed overlapping values between the two groups. Serum PCT with cut off value >2 ng/ml showed sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 66%, 68%, and 100%, respectively, for the diagnosis of bacterial meningitis.

Conclusion:

Serum procalcitonin level has a better diagnostic and prognostic value than CRP or leukocyte count to distinguish between bacterial and viral meningitis. It is also a good indicator of the efficacy of treatment of bacterial meningitis.

Biomarkers for pediatric sepsis and septic shock

Sepsis is a clinical syndrome defined by physiologic changes indicative of systemic inflammation, which are likely attributable to documented or suspected infection. Septic shock is the progression of those physiologic changes to the extent that delivery of oxygen and metabolic substrate to tissues is compromised. Biomarkers have the potential to diagnose, monitor, stratify and predict outcome in these syndromes. C-reactive protein is elevated in inflammatory and infectious conditions and has long been used as a biomarker indicating infection. Procalcitonin has more recently been shown to better distinguish infection from inflammation. Newer candidate biomarkers for infection include IL-18 and CD64. Lactate facilitates the diagnosis of septic shock and the monitoring of its progression. Multiple stratification biomarkers based on genome-wide expression profiling are under active investigation and present exciting future possibilities.

Neonatal Procalcitonin Intervention Study (NeoPInS): Effect of Procalcitonin-guided decision making on duration of antibiotic therapy in suspected neonatal early-onset sepsis: A multi-centre randomized superiority and non-inferiority Intervention Study

BACKGROUND

Early diagnosis and treatment of the newborn infant with suspected sepsis are essential to prevent severe and life threatening complications. Diagnosis of neonatal sepsis is difficult because of the variable and nonspecific clinical presentation. Therefore, many newborns with nonspecific symptoms are started on antibiotic treatment before the presence of sepsis has been proven. With our recently published single-centre intervention study we were able to show that Procalcitonin determinations allowed to shorten the duration of antibiotic therapy in newborns with suspected early-onset sepsis.

METHODS/DESIGN

The study is designed as randomized controlled international multicenter intervention trial on the efficacy and safety of Procalcitonin guided treatment. Term and near-term infants (gestational age ≥ 34 0/7 weeks) with suspected sepsis in the first 3 days of life requiring empiric antibiotic therapy will be included. The duration of antibiotic therapy in the standard group is based on the attending physician's assessment of the likelihood of infection (infection unlikely, possible, probable or proven). In the Procalcitonin group, if infection is considered to be unlikely or possible, antibiotic therapy is discontinued when two consecutive Procalcitonin values are within the normal range. Co-primary outcome measures are the duration of antibiotic therapy (superiority aspect of the trial) and the proportion of infants with a recurrence of infection requiring additional courses of antibiotic therapy and/or death in the first month of life (safety of study intervention, non-inferiority aspect of the trial). The number of infants to be included equals 800 per arm. With these numbers the power of the study to demonstrate superiority for duration of antibiotic therapy as well as non-inferiority regarding safety, i.e. excluding a disadvantage difference larger than 2% for the experimental arm, will both be greater than 80%.

DISCUSSION

Benefit of the study is a possible limitation of unnecessary use of antibiotics. The results of our first study suggest that there is a low risk on discontinuing antibiotic treatment too early, resulting in the development of a neonatal infection with its morbidity and mortality.

TRIAL REGISTRATION

This trial is registered in the U.S. National Institutes of Health's register, located at http://www.clinicaltrials.gov. (NCT00854932).

Adjunct laboratory tests in the diagnosis of early-onset neonatal sepsis

Early-onset sepsis remains a major diagnostic problem in neonatal medicine. Definitive diagnosis depends on cultures of blood or other normally sterile body fluids. Abnormal hematological counts, acute-phase reactants, and inflammatory cytokines are neither sensitive nor specific, especially at the onset of illness. Combinations of measurements improve diagnostic test performance, but the optimal selection of analytes has not been determined. The best-established use of these laboratory tests is for retrospective determination that an infant was not infected, based on failure to mount an acute-phase response over the following 24 to 48 hours.

Procalcitonin as a marker of severe bacterial infection in children in the emergency department

Procalcitonin, the prohormone of calcitonin, is a relatively new and innovative marker of bacterial infection that has multiple potential applications in the pediatric emergency department. In healthy individuals, circulating levels of procalcitonin are generally very low (<0.05 ng/mL), but in the setting of severe bacterial infection and sepsis, levels can increase by hundreds to thousands of fold within 4 to 6 hours. Although the exact physiologic function of procalcitonin has not been determined, the consistent response and rapid rise of this protein in the setting of severe bacterial infection make procalcitonin a very useful biomarker for invasive bacterial disease. In Europe, serum procalcitonin measurements are frequently used in the diagnosis and the management of patients in a variety of clinical settings. To date, the use of procalcitonin has been limited in the United States, but this valuable biomarker has many potential applications in both the pediatric emergency department and the intensive care unit. The intent of this article is to review the history of procalcitonin, describe the kinetics of the molecule in response to bacterial infection, describe the laboratory methods available for measuring procalcitonin, examine the main causes of procalcitonin elevation, and evaluate the potential applications of procalcitonin measurements in pediatric patients.

Is serum procalcitonin a reliable diagnostic marker in children with acute respiratory tract infections? A retrospective analysis

INTRODUCTION

Acute respiratory tract infections (ARI) in children are often treated with antibiotics even without evidence of bacterial infection. Serum procalcitonin (PCT) is elevated in bacterial but not in viral infections.

PATIENTS AND METHODS

We performed a retrospective analysis of children in the PID-ARI.net study on respiratory infections to address the question of whether plasma PCT could potentially distinguish between bacterial infections requiring antibiotic therapy and viral ARI. We analysed data on 327 children who had been included in the German PID-ARI.net study and in whom nasopharyngeal aspirates had been analysed with a 19-valent multiplex reverse transcription-polymerase chain reaction-enzyme-linked immunosorbent assay for viral and atypical bacterial pathogens. Serum PCT was determined using a quantitative immunoassay (BRAHMS Kryptor PCTsensitive, Henningsdorf, Germany). We then focussed specifically on those children who were treated with antibiotics and therefore had been suspected of having bacterial infection but who had a serum PCT level lower than 0.1 ng/ml.

RESULTS

Out of 327 children, 132 had serum PCT levels below 0.1 ng/ml. Of these 132, 38 children had been treated with antibiotics. After exclusion of 26 patients (with critical illnesses, antibiotics on admission or for reasons other than ARI), 12 children remained for further evaluation. Of these 12 children, four had atypical pneumonia; four others had positive virus testing, and, in the last four, the aetiology of ARI remained unknown; evidence of bacterial infection could not be detected in any.

CONCLUSIONS

Taken the results of this retrospective analysis, serum PCT values below 0.1 ng/ml might be a marker to identify children with acute respiratory tract infection in whom antibiotic treatment could be withheld. However, only a prospective intervention trial will prove the general safety of this limit.

Procalcitonin as a marker of nosocomial infections in the neonatal intensive care unit

OBJECTIVE

To determine accuracy of procalcitonin concentrations for diagnosing nosocomial infections in critically ill neonates.

DESIGN

Case-control study.

SETTING

Neonatal intensive care unit of a teaching hospital.

PATIENTS

Twenty-three neonates with nosocomial infection. Four controls matched for duration of hospital stay and birth date were chosen for each case patient.

MEASUREMENTS AND RESULTS

PCT concentrations were measured by the LUMItest procalcitonin kit at onset of signs of infection and after recovery. Range of PCT concentrations (ng/ml) was 2.0 to 249.1 in case patients and 0.08 to 1.0 in controls (sensitivity and specificity, 100%). PCT values returned to normal (<1.0 ng/ml) by day 3 to 7 of appropriate antibiotic therapy.

CONCLUSIONS

Measurement of PCT concentrations may be useful for early diagnosis and monitoring of infectious complications in neonates during their stay in the neonatal intensive care unit.

Procalcitonin-a new diagnostic tool in complications following liver transplantation

OBJECTIVE

Does procalcitonin (PCT) allow differentiation between infection and rejection following liver transplantation in the case of fever of unknown origin (FUO)?

DESIGN

Open prospective trial.

SETTING

transplant intensive care unit at a university hospital.

PATIENTS

Forty patients after liver transplantation.

INTERVENTIONS

Liver biopsy for diagnosis of rejection, transcutaneous aspiration cytology for monitoring of lymphocyte activation.

MEASUREMENTS

Procalcitonin from EDTA plasma, APACHE II, Sepsis, score (Elbute and Stoner).

RESULTS

Eleven patients suffered an infectious complication resulting in an increase in PCT levels (2.2-41.7 ng/ml). Eleven patients developed a rejection episode; none of these patients showed a rise in PCT levels. The statistical difference between PCT levels in rejection and infection was significant (p<0.05) on the day of diagnosis.

CONCLUSION

PCT allows differentiation between rejection and infection in the case of FUO. Elevation of PCT plasma levels develops early postoperatively due to operation trauma, and, in the case of FUO with no rise in PCT, a rejection may be suspected.

The natural elimination rate of procalcitonin in patients with normal and impaired renal function

OBJECTIVE

Procalcitonin (PCT) plasma concentrations and its kinetic can be used as a diagnostic tool in critically ill patients and patients with sepsis. Since renal dysfunction is a frequent complication in these patients, and PCT is a protein with a low molecular weight, we have measured the half-life time of PCT after peak concentrations in patients with normal and impaired renal function. We also have analyzed the influence of patients age and gender on PCT elimination kinetics.

DESIGN

Prospective clinical study. Renal dysfunction was assessed by plasma creatinine. The half-life time of PCT was evaluated 24 and 48 h after acute induction of PCT, when the focus of PCT induction has rapidly been eliminated.

SETTING

Intensive care unit of our University hospital, a tertiary health care institution.

PATIENTS

69 patients were included into the study.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

The half-life-time of PCT was not significantly altered during renal dysfunction (26.1-33.1 h, 25-50 percentiles, creatinine clearance < 30 ml/min) when compared with normal renal function (22.3-28.9 h). It neither correlated with creatinine clearance (p=0.14), nor age (p=0.99) or gender (p=0.90, Pearson product-moment correlation).

CONCLUSIONS

The data of the present study demonstrate that assessment of PCT kinetic can also be used for diagnostic and prognostic reasons in patients with renal dysfunction. It may, however, exceed 24 h also in patients with normal renal function. As to the present knowledge, renal secretion does not contribute as a main pathway to PCT elimination.

Procalcitonin-a sensitive inflammation marker of febrile episodes in neutropenic children with cancer

OBJECTIVE

Sensitive parameters of inflammations, are rare or of limited validity in neutropenic patients. Procalcitonin (PCT) proven to be a sensitive inflammatory marker in nonneutropenic patients was evaluated for its diagnostic relevance in febrile episodes of neutropenic patients with cancer

METHODS

Plasma levels of PCT were determined by an immunoluminometric assay in children with febrile neutropenic episodes (n=376) starting at the date of admission until the resolution of fever and were correlated with serum levels of the C-reactive protein (CrP). Febrile episodes were classified as fever of unknown origin (FUO), microbiologically or clinically documented infections and were also differentiated according to the site of the infection (unknown, bacteremia, respiratory, soft tissue, gastrointestinal and urinary tract infection).

RESULTS

Independently from the aetiology and the site of infection the PCT peak value occurred mostly on the second hospital day and decreased rapidly in cases of successful antibiotic therapy and with the resolution of fever to the normal range (0.1+/-0.5 microg/l). The highest PCT peak levels at the onset of fever and during the febrile course were observed in patients with gramnegative bacteremia (n = 22, median 12.1 microg/l, range 0.4+/-568.2 microg/l). There was a positive correlation between PCT peak levels and CrP peak levels (r = 0.48, p = 0.001) which mostly were observed 24 h later than for PCT.

CONCLUSIONS

PCT is a sensitive and specific parameter in the diagnostic and in the sequential assessment of febrile neutropenic episodes, especially in gramnegative infections. Its diagnostic accuracy in neutropenic patients is clearly higher than that of CrP.

The natural elimination rate of procalcitonin in patients with normal and impaired renal function

OBJECTIVE

Procalcitonin (PCT) plasma concentrations and its kinetic can be used as a diagnostic tool in critically ill patients and patients with sepsis. Since renal dysfunction is a frequent complication in these patients, and PCT is a protein with a low molecular weight, we have measured the half-life time of PCT after peak concentrations in patients with normal and impaired renal function. We also have analyzed the influence of patients age and gender on PCT elimination kinetics.

DESIGN

Prospective clinical study. Renal dysfunction was assessed by plasma creatinine. The half-life time of PCT was evaluated 24 and 48 h after acute induction of PCT, when the focus of PCT induction has rapidly been eliminated.

SETTING

Intensive care unit of our University hospital, a tertiary health care institution.

PATIENTS

69 patients were included into the study.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

The half-life-time of PCT was not significantly altered during renal dysfunction (26.1-33.1 h, 25-50 percentiles, creatinine clearance < 30 ml/min) when compared with normal renal function (22.3-28.9 h). It neither correlated with creatinine clearance (p=0.14), nor age (p=0.99) or gender (p=0.90, Pearson product-moment correlation).

CONCLUSIONS

The data of the present study demonstrate that assessment of PCT kinetic can also be used for diagnostic and prognostic reasons in patients with renal dysfunction. It may, however, exceed 24 h also in patients with normal renal function. As to the present knowledge, renal secretion does not contribute as a main pathway to PCT elimination.