Assessment of the advantage of the serum S100B protein biomonitoring in the management of paediatric mild traumatic brain injury-PROS100B: protocol of a multicentre unblinded stepped wedge cluster randomised trial

Serum GFAP and UCH-L1 for the identification of clinically important traumatic brain injury in children in France: a diagnostic accuracy substudy

BACKGROUND

Many children with mild traumatic brain injury (mTBI), defined by a Glasgow Coma Scale (GCS) score between 13 and 15, undergo hospitalisation or cranial CT (CCT) scans despite the absence of clinically important traumatic brain injury (ciTBI; ie, hospitalisation >2 days associated with intracranial lesions on CCT, neurosurgical intervention, intensive care admission, or death). Clinical algorithms have reduced CCT scans and hospitalisations by 10%. We aimed to established age-appropriate reference values for GFAP and UCH-L1 and evaluate their diagnostic test performance in identifying ciTBI in children.

METHODS

This study was a diagnostic test accuracy substudy within the PROS100B stepped wedge cluster randomised trial that included children aged 16 years or younger, clinically managed within 3 h of mTBI, with a GCS score of 15 requiring hospitalisation or CCT scan according to French Pediatric Society guidelines (equivalent to the intermediate risk group of the PECARN algorithm). Enrolment for PROS100B occurred from Nov 1, 2016, to Oct 31, 2021, at 11 hospital emergency departments in France. Stored blood samples collected from March 1, 2015, to Oct 31, 2015, from children aged 16 years or younger who were outpatients for allergic conditions unrelated to mTBI and free of neurological disease were used as a control group to calculate reference values of GFAP and UCH-L1 across four age groups (<6 months, 6 months to <2 years, 2 years to <4 years, and 4 years to <16 years). The diagnostic test performance of GFAP and UCH-L1, both above the reference range to identify ciTBI, was evaluated in the children with mTBI. GFAP and UCH-L1 were measured with the Alinity analyser (Abbott, Chicago, IL, USA).

FINDINGS

Reference values were calculated from GFAP and UCH-L1 measured in samples from 718 control children (378 [53%] boys and 340 [47%] girls). 531 children (334 [63%] boys and 197 [37%] girls) aged 0-16 years with mTBI were included. By applying our reference values for GFAP and UCH-L1 across four age groups the biomarker combination (both biomarkers above reference ranges) had a sensitivity of 100% (95% CI 69-100), a negative predictive value of 100% (99-100), a specificity of 67% (63-71), a positive likelihood ratio of 3·01 (2·67-3·40), a negative likelihood ratio of 0, and an area under the curve of 0·83 (0·81-0·85) in identifying ciTBI.

INTERPRETATION

Serum GFAP and UCH-L1 identify ciTBI in children with 100% sensitivity and 67% specificity, which could potentially reduce unnecessary CCT scans and hospitalisations in children with mTBI if implemented.

FUNDING

French Ministry of Health.

Blood Biomarkers for the Management of Mild Traumatic Brain Injury in Clinical Practice

BACKGROUND

Despite the use of validated guidelines in the management of mild traumatic brain injury (mTBI), processes to limit unnecessary brain scans are still not sufficient and need to be improved. The use of blood biomarkers represents a relevant adjunct to identify patients at risk for intracranial injury requiring computed tomography (CT) scan.

CONTENT

Biomarkers currently recommended in the management of mTBI in adults and children are discussed in this review. Protein S100 beta (S100B) is the best-documented blood biomarker due to its validation in large observational and interventional studies. Glial fibrillary acidic protein (GFAP) and ubiquitin carboxyterminal hydrolase L-1 (UCH-L1) have also recently demonstrated their usefulness in patients with mTBI. Preanalytical, analytical, and postanalytical performance are presented to aid in their interpretation in clinical practice. Finally, new perspectives on biomarkers and mTBI are discussed.

SUMMARY

In adults, the inclusion of S100B in Scandinavian and French guidelines has reduced the need for CT scans by at least 30%. S100B has significant potential as a diagnostic biomarker, but limitations include its rapid half-life, which requires blood collection within 3 h of trauma, and its lack of neurospecificity. In 2018, the FDA approved the use of combined determination of GFAP and UCH-L1 to aid in the assessment of mTBI. Since 2022, new French guidelines also recommend the determination of GFAP and UCH-L1 in order to target a larger number of patients (sampling within 12 h post-injury) and optimize the reduction of CT scans. In the future, new cut-offs related to age and promising new biomarkers are expected for both diagnostic and prognostic applications.

French multi-institutional cost-effectiveness analysis of gemcitabine plus nab-paclitaxel versus gemcitabine alone as second-line treatment in metastatic pancreatic cancer patients

Context

In France, gemcitabine plus nab-paclitaxel (GEM-NAB) is heterogeneously used in metastatic pancreatic cancer due to disparities in its financial accessibility in the institutions.

Objectives

GEM-NAB conduct a French multi-institutional cost-effectiveness analysis of GEM-NAB versus gemcitabine alone (GEM) as second-line treatment in pancreatic cancer patients.

Design

All the unresected metastatic pancreatic ductal adenocarcinoma (PDAC) consecutive patients who received GEM-NAB (institution 1) or GEM alone (institutions 2 and 3) as second-line treatment after failure of a 5-fluorouracil based systemic chemotherapy regimen were screened.

Methods

This study was conducted from the French national healthcare insurance perspective. The primary endpoint was the overall survival (OS) expressed in months, calculated from the date of the first second-line chemotherapy administration to death. Only direct (medical and non-medical) costs have been considered for this analysis. Data were collected retrospectively in one university hospital and two general hospitals.

Results

The OS was significantly improved in patients receiving GEM-NAB (hazard ratio: 0.54, 95% confidence interval: 0.38-0.77, p = 0.001), with a median OS of 6.2 months (versus 4.1 months in patients receiving GEM alone). Taking into account the cost of GEM-NAB which was afforded by each institution, the incremental cost-effectiveness ratio was €1,449,231 by year of life (€40,256 per patient). In both groups, most of the costs were attributable to readmissions and outpatient chemotherapy administration.

Conclusion

The issues of the article is based on the trade-off between the benefit in terms of OS of patients treated with GEM-NAB, which is minor (a gain of 2 months of survival, with an accumulated rate of grade ⩾ 3 non-hematological adverse effects) and the additional institutional cost (€25k per year of life for each patient treated). The debate is complex and refers to an ethical component, which is the cost of human life when no other therapeutic alternative is offered to the patient.

Serum S100B Level in the Management of Pediatric Minor Head Trauma: A Randomized Clinical Trial

Importance

Minor head trauma (HT) is one of the most common causes of hospitalization in children. A diagnostic test could prevent unnecessary hospitalizations and cranial computed tomographic (CCT) scans.

Objective

To evaluate the effectiveness of serum S100B values in reducing exposure to CCT scans and in-hospital observation in children with minor HT.

Design, Setting, and Participants

This multicenter, unblinded, prospective, interventional randomized clinical trial used a stepped-wedge cluster design to compare S100B biomonitoring and control groups at 11 centers in France. Participants included children and adolescents 16 years or younger (hereinafter referred to as children) admitted to the emergency department with minor HT. The enrollment period was November 1, 2016, to October 31, 2021, with a follow-up period of 1 month for each patient. Data were analyzed from March 7 to May 29, 2023, based on the modified intention-to-treat and per protocol populations.

Interventions

Children in the control group had CCT scans or were hospitalized according to current recommendations. In the S100B biomonitoring group, blood sampling took place within 3 hours after minor HT, and management depended on serum S100B protein levels. If the S100B level was within the reference range according to age, the children were discharged from the emergency department. Otherwise, children were treated as in the control group.

Main Outcomes and Measures

Proportion of CCT scans performed (absence or presence of CCT scan for each patient) in the 48 hours following minor HT.

Results

A total of 2078 children were included: 926 in the control group and 1152 in the S100B biomonitoring group (1235 [59.4%] boys; median age, 3.2 [IQR, 1.0-8.5] years). Cranial CT scans were performed in 299 children (32.3%) in the control group and 112 (9.7%) in the S100B biomonitoring group. This difference of 23% (95% CI, 19%-26%) was not statistically significant (P = .44) due to an intraclass correlation coefficient of 0.32. A statistically significant 50% reduction in hospitalizations (95% CI, 47%-53%) was observed in the S100B biomonitoring group (479 [41.6%] vs 849 [91.7%]; P < .001).

Conclusions and Relevance

In this randomized clinical trial of effectiveness of the serum S100B level in the management of pediatric minor HT, S100B biomonitoring yielded a reduction in the number of CCT scans and in-hospital observation when measured in accordance with the conditions defined by a clinical decision algorithm.

Trial Registration

ClinicalTrials.gov Identifier: NCT02819778.

Serum biomarkers of hypoxic-ischemic brain injury

Brain injury is a multifaceted condition arising from nonspecific damage to nervous tissue. The resulting cognitive developmental impairments reverberate through patients' lives, affecting their families, and even the broader economic landscape. The significance of early brain injury detection lies in its potential to stave off severe consequences and enhance the effectiveness of tailored therapeutic interventions. While established methods like neuroimaging and neurophysiology serve as valuable diagnostic tools, their demanding nature restricts their accessibility, particularly in scenarios such as small hospitals, nocturnal or weekend shifts, and cases involving unstable patients. Hence, there is a pressing need for more accessible and efficient diagnostic avenues. Among the spectrum of brain injuries, hypoxic-ischemic encephalopathy stands out as a predominant affliction in the pediatric population. Diagnosing brain injuries in newborns presents challenges due to the subjective nature of assessments like Apgar scores and the inherent uncertainty in neurological examinations. In this context, methods like magnetic resonance and ultrasound hold recommendations for more accurate diagnosis. Recognizing the potential of serum biomarkers derived from blood samples, this paper underscores their promise as a more expedient and resource-efficient means of assessing brain injuries. The review compiles current insights into serum biomarkers, drawing from experiments conducted on animal models as well as human brain pathologies. The authors aim to elucidate specific characteristics, temporal profiles, and the available corpus of experimental and clinical data for serum biomarkers specific to brain injuries. These include neuron-specific enolase (NSE), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), S100 calcium-binding protein beta (S100B), glial fibrillary acidic protein (GFAP), and high-mobility-group-protein-box-1 (HMGB1). This comprehensive endeavor contributes to advancing the understanding of brain injury diagnostics and potential avenues for therapeutic intervention.

S100B, Actor and Biomarker of Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) accounts for approximately 80% of all TBI cases and is a growing source of morbidity and mortality worldwide. To improve the management of children and adults with mTBI, a series of candidate biomarkers have been investigated in recent years. In this context, the measurement of blood biomarkers in the acute phase after a traumatic event helps reduce unnecessary CT scans and hospitalizations. In athletes, improved management of sports-related concussions is also sought to ensure athletes' safety. S100B protein has emerged as the most widely studied and used biomarker for clinical decision making in patients with mTBI. In addition to its use as a diagnostic biomarker, S100B plays an active role in the molecular pathogenic processes accompanying acute brain injury. This review describes S100B protein as a diagnostic tool as well as a potential therapeutic target in patients with mTBI.

S100B Protein but Not 3-Nitrotyrosine Positively Correlates with Plasma Ammonia in Patients with Inherited Hyperammonemias: A New Promising Diagnostic Tool?

Individuals with inherited hyperammonemias often present developmental and intellectual deficiencies which are likely to be exaggerated by hyperammonemia episodes in long-term outcomes. In order to find a new, systemic marker common to the course of congenital hyperammonemias, we decided to measure the plasma level of S100 calcium-binding protein B (S100B), which is associated with cerebral impairment. Further, we analyzed three mechanistically diverged but linked with oxidative-nitrosative stress biochemical parameters: 3-nitrotyrosine (3-NT), a measure of plasma proteins' nitration; advanced oxidation protein products (AOPP), a measure of protein oxidation; and glutathione peroxidase (GPx) activity, a measure of anti-oxidative enzymatic capacity. The plasma biomarkers listed above were determined for the first time in congenital hyperammonemia. Also, the level of pro- and anti-inflammatory mediators (i.e., IL-12, IL-6, IL-8, TNF-α, IL-1β, and IL-10) and chemokines (IP-10, MCP-1, MIG, and RANTES) were quantified. S100B was positively correlated with plasma ammonia level, while noticeable levels of circulating 3-NT in some of the patients' plasma did not correlate with ammonia concentration. Overall, the linear correlation between ammonia and S100B but not standard oxidative stress-related markers offers a unique perspective for the future identification and monitoring of neurological deficits risk-linked with hyperammonemia episodes in patients with inherited hyperammonemias. The S100B measure may support the development of therapeutic targets and clinical monitoring in these disorders.

GFAP and S100B: What You Always Wanted to Know and Never Dared to Ask

Traumatic brain injury (TBI) is a major global health issue, with outcomes spanning from intracranial bleeding, debilitating sequelae, and invalidity with consequences for individuals, families, and healthcare systems. Early diagnosis of TBI by testing peripheral fluids such as blood or saliva has been the focus of many research efforts, leading to FDA approval for a bench-top assay for blood GFAP and UCH-L1 and a plasma point-of-care test for GFAP. The biomarker S100B has been included in clinical guidelines for mTBI (mTBI) in Europe. Despite these successes, several unresolved issues have been recognized, including the robustness of prior data, the presence of biomarkers in tissues beyond the central nervous system, and the time course of biomarkers in peripheral body fluids. In this review article, we present some of these issues and provide a viewpoint derived from an analysis of existing literature. We focus on two astrocytic proteins, S100B and GFAP, the most commonly employed biomarkers used in mTBI. We also offer recommendations that may translate into a broader acceptance of these clinical tools.

Blood-based traumatic brain injury biomarkers - Clinical utilities and regulatory pathways in the United States, Europe and Canada

INTRODUCTION

Traumatic brain injury (TBI) is a major global health issue, resulting in debilitating consequences to families, communities, and health-care systems. Prior research has found that biomarkers aid in the pathophysiological characterization and diagnosis of TBI. Significantly, the FDA has recently cleared both a bench-top assay and a rapid point-of-care assays of tandem biomarker (UCH-L1/GFAP)-based blood test to aid in the diagnosis mTBI patients. With the global necessity of TBI biomarkers research, several major consortium multicenter observational studies with biosample collection and biomarker analysis have been created in the USA, Europe, and Canada. As each geographical region regulates its data and findings, the International Initiative for Traumatic Brain Injury Research (InTBIR) was formed to facilitate data integration and dissemination across these consortia.

AREAS COVERED

This paper covers heavily investigated TBI biomarkers and emerging non-protein markers. Finally, we analyze the regulatory pathways for converting promising TBI biomarkers into approved in-vitro diagnostic tests in the United States, European Union, and Canada.

EXPERT OPINION

TBI biomarker research has significantly advanced in the last decade. The recent approval of an iSTAT point of care test to detect mild TBI has paved the way for future biomarker clearance and appropriate clinical use across the globe.

Biomarkers for Traumatic Brain Injury: Data Standards and Statistical Considerations

Recent biomarker innovations hold potential for transforming diagnosis, prognostic modeling, and precision therapeutic targeting of traumatic brain injury (TBI). However, many biomarkers, including brain imaging, genomics, and proteomics, involve vast quantities of high-throughput and high-content data. Management, curation, analysis, and evidence synthesis of these data are not trivial tasks. In this review, we discuss data management concepts and statistical and data sharing strategies when dealing with biomarker data in the context of TBI research. We propose that application of biomarkers involves three distinct steps-discovery, evaluation, and evidence synthesis. First, complex/big data has to be reduced to useful data elements at the stage of biomarker discovery. Second, inferential statistical approaches must be applied to these biomarker data elements for assessment of biomarker clinical utility and validity. Last, synthesis of relevant research is required to support practice guidelines and enable health decisions informed by the highest quality, up-to-date evidence available. We focus our discussion around recent experiences from the International Traumatic Brain Injury Research (InTBIR) initiative, with a specific focus on four major clinical projects (Transforming Research and Clinical Knowledge in TBI, Collaborative European NeuroTrauma Effectiveness Research in TBI, Collaborative Research on Acute Traumatic Brain Injury in Intensive Care Medicine in Europe, and Approaches and Decisions in Acute Pediatric TBI Trial), which are currently enrolling subjects in North America and Europe. We discuss common data elements, data collection efforts, data-sharing opportunities, and challenges, as well as examine the statistical techniques required to realize successful adoption and use of biomarkers in the clinic as a foundation for precision medicine in TBI.

A blood biomarker and clinical correlation cohort study protocol to diagnose sports-related concussion and monitor recovery in elite rugby

Introduction

In professional rugby, sports-related concussion (SRC) remains the most frequent time loss injury. Therefore, accurately diagnosing SRC and monitoring player recovery, through a multi-modal assessment process, is critical to SRC management. In this protocol study, we aim to assess SRC over multiple time points post-injury to determine the value of multi-modal assessments to monitor player recovery. This is of significance to minimise premature return-to-play and, ultimately, to reduce the long-term effects associated with SRC. The study will also establish the logistics of implementing such a study in a professional setting to monitor a player's SRC recovery.

Methods and analysis

All players from the participating professional rugby club within the Irish Rugby Football Union are invited to participate in the current study. Player assessment includes head injury assessment (HIA), neuropsychometric assessment (ImPACT), targeted biomarker analysis and untargeted biomarker analysis. Baseline HIA, ImPACT, and blood draws are performed prior to the start of playing season. During the baseline tests, player's complete consent forms and an SRC history questionnaire. Subsequently, any participant that enters the HIA process over the playing season due to a suspected SRC will be clinically assessed (HIA and ImPACT) and their blood will be drawn within 3 days of injury, 6 days post-injury, and 13 days post-injury.

Ethics and dissemination

Ethical approval was attained from the Science and Engineering Research Ethics Committee, University of Limerick (Approval Code: 2018_06_11_S&E). On completion of the study, further manuscripts will be published to present the results of the tests and their ability to measure player recovery from SRC.

Trial registration number

NCT04485494.