Brain-Derived Neurotrophic Factor in Pediatric Acquired Brain Injury and Recovery

We review emerging preclinical and clinical evidence regarding brain-derived neurotrophic factor (BDNF) protein, genotype, and DNA methylation (DNAm) as biomarkers of outcomes in three important etiologies of pediatric acquired brain injury (ABI), traumatic brain injury, global cerebral ischemia, and stroke. We also summarize evidence suggesting that BDNF is (1) involved in the biological embedding of the psychosocial environment, (2) responsive to rehabilitative therapies, and (3) potentially modifiable. BDNF's unique potential as a biomarker of neuroplasticity and neural repair that is reflective of and responsive to both pre- and post-injury environmental influences separates it from traditional protein biomarkers of structural brain injury with exciting potential to advance pediatric ABI management by increasing the accuracy of prognostic tools and informing clinical decision making through the monitoring of therapeutic effects.

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.

Brain-Derived Neurotrophic Factor Val66Met and Behavioral Adjustment after Early Childhood Traumatic Brain Injury

The present study examined the differential effect of the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism on behavioral adjustment in children with traumatic brain injury (TBI) relative to children with orthopedic injury (OI). Participants were drawn from a prospective, longitudinal study of children who sustained a TBI (n = 69) or OI (n = 72) between 3 and 7 years of age. Parents completed the Child Behavior Checklist (CBCL) at the immediate post-acute period, 6, 12, and 18 months after injury, and an average of 3.5 and 7 years after injury. Longitudinal mixed models examined the BDNF Val66Met allele status (Met carriers vs. Val/Val homozygotes) × injury group (TBI vs. OI) interaction in association with behavioral adjustment. After adjusting for continental ancestry, socioeconomic status, time post-injury, and pre-injury functioning, the allele status × injury group interaction was statistically significant for Internalizing, Externalizing, and Total Behavior problems. Post hoc within-group analysis suggested a consistent trend of poorer behavioral adjustment in Met carriers relative to Val/Val homozygotes in the TBI group; in contrast, the opposite trend was observed in the OI group. These within-group differences, however, did not reach statistical significance. The results support a differential effect of the BDNF Val66Met polymorphism on behavioral adjustment in children with early TBI relative to OI, and suggest that the Met allele associated with reduced activity-dependent secretion of BDNF may impart risk for poorer long-term behavioral adjustment in children with 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.

[APOΕ gene polymorphism and markers of brain damage in the outcomes of severe traumatic brain injury in children]

OBJECTIVE

To compare apolipoprotein E (APOE) genotypes with outcomes and levels of neuromarkers in children with severe traumatic brain injury (TBI).

MATERIAL AND METHODS

APOE polymorphisms were genotyped in 69 children with severe TBI. The following markers of brain damage were identified: neuron-specific enolase (NSE), glial protein S100b, content of autoantibodies (aAB) to glutamate receptors (to the NR2 subunit of NMDA receptors), aAB to S100b and brain-derived neurotrophic factor (BDNF).

RESULTS AND CONCLUSION

There was no association between APOE 3/3, 3/4, 3/2 genotypes and outcomes assessed by the Glasgow Outcome Scale (GOS). The greatest number of favorable outcomes was noted in the group of APOE 3/3 genotype carriers (60%). The ratio of favorable outcomes to unfavorable outcomes was equal (50%:50%) in groups with APOE 3/4 and APOE 3/2 genotypes. An association between APOE polymorphism and BDNF was found: there were normal BDNF levels in the APOE 3/3 group and reduced levels in the APOE 3/2 group. The correlation between neuromarkers and GOS scores was shown for BDNF and aAB to S100b. In children with favorable TBI outcomes, normal BDNF levels and a lower level of aAB to S100b were observed. Regardless of APOE genotypes, almost all children with severe TBI (95%) showed a significant increase in aAB to glutamate receptors in the remote period and most children had an increase in aAB to S100b in the blood. This fact can be explained by the presence of cerebral hypoxia, activation of autoimmune processes and increased BBB permeability, which may be enhanced by increased NO content and intensification of oxidative processes in children with severe TBI.

Epigenetic Effects on Pediatric Traumatic Brain Injury Recovery (EETR): An Observational, Prospective, Longitudinal Concurrent Cohort Study Protocol

Introduction: Unexplained heterogeneity in outcomes following pediatric traumatic brain injury (TBI) is one of the most critical barriers to the development of effective prognostic tools and therapeutics. The addition of personal biological factors to our prediction models may account for a significant portion of unexplained variance and advance the field toward precision rehabilitation medicine. The overarching goal of the Epigenetic Effects on Pediatric Traumatic Brain Injury Recovery (EETR) study is to investigate an epigenetic biomarker involved in both childhood adversity and postinjury neuroplasticity to better understand heterogeneity in neurobehavioral outcomes following pediatric TBI. Our primary hypothesis is that childhood adversity will be associated with worse neurobehavioral recovery in part through an epigenetically mediated reduction in brain-derived neurotrophic factor (BDNF) expression in response to TBI. Methods and analysis: EETR is an observational, prospective, longitudinal concurrent cohort study of children aged 3-18 years with either TBI (n = 200) or orthopedic injury (n = 100), recruited from the UPMC Children's Hospital of Pittsburgh. Participants complete study visits acutely and at 6 and 12 months postinjury. Blood and saliva biosamples are collected at all time points-and cerebrospinal fluid (CSF) when available acutely-for epigenetic and proteomic analysis of BDNF. Additional measures assess injury characteristics, pre- and postinjury child neurobehavioral functioning, childhood adversity, and potential covariates/confounders. Recruitment began in July 2017 and will occur for ~6 years, with data collection complete by mid-2023. Analyses will characterize BDNF DNA methylation and protein levels over the recovery period and investigate this novel biomarker as a potential biological mechanism underlying the known association between childhood adversity and worse neurobehavioral outcomes following pediatric TBI. Ethics and dissemination: The study received ethics approval from the University of Pittsburgh Institutional Review Board. Participants and their parents provide informed consent/assent. Research findings will be disseminated via local and international conference presentations and manuscripts submitted to peer-reviewed journals. Trial Registration: The study is registered with clinicaltrials.org (ClinicalTrials.gov Identifier: NCT04186429).

Variation in Candidate Traumatic Brain Injury Biomarker Genes Are Associated with Gross Neurological Outcomes after Severe Traumatic Brain Injury

Diagnostic and prognostic biomarkers of traumatic brain injury (TBI) are actively being pursued; potential candidates include glial fibrillary acid protein (GFAP), S100 calcium-binding protein B (S100B), and ubiquitin C-terminal hydrolase L1 (UCHL1), two of which the United States Food and Drug Administration (FDA) recently approved for marketing of blood tests for adult concussion. The relationship between biomarker-encoding genes and TBI outcomes remains unknown. This pilot study explores variation in 18 single nucleotide polymorphisms (SNPs) in biomarker-encoding genes as predictors of neurological outcome in a population of adults with severe TBI. Participants (n = 305) were assessed using the Glasgow Outcome Scale (GOS) at 3, 6, 12, and 24 months post-injury. Multivariate logistical regression was used to calculate the odds ratio (OR) and determine the odds of having a lower score on the GOS ( = 1-2 vs. 3-5) based on variant allele presence, while controlling for confounders. Possession of the variant allele of one S100B SNP (rs1051169) was associated with higher scores on the GOS at 3 months (OR = 0.39; p = 0.04), 6 months (OR = 0.34; p = 0.02), 12 months (OR = 0.32; p = 0.02), and 24 months (OR = 0.30; p = 0.02) post-severe TBI. The relationship among these polymorphisms, protein levels, and biomarker utility, merits examination. These findings represent a novel contribution to the evidence that can inform future studies aimed at enhancing interpretation of biomarker data, identifying novel biomarkers, and ultimately harnessing this information to improve clinical outcomes and personalize care.

Metabolic syndrome and its components with neuron-specific enolase: a cross-sectional study in large health check-up population in China

OBJECTIVE

This study was aimed at investigating the relationship between neuron-specific enolase (NSE) and components of metabolic syndrome (MS).

DESIGN

Cross-sectional study.

SETTING

Chinese health check-up population.

PARTICIPANTS

40 684 health check-up people were enrolled in this study from year 2014 to 2016.

MAIN OUTCOME MEASURES

OR and coefficient for MS.

RESULTS

The percentage of abnormal NSE and MS was 26.85% and 8.85%, respectively. There were significant differences in sex, body mass index, drinking habit, triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), blood pressure and MS between low-NSE and high-NSE groups. In logistic regression analysis, elevated NSE was present in MS, higher body mass index, hypertriglyceridaemia, hypertension and low-HDL groups. Stepwise linear analysis showed a negative correlation between NSE and fasting blood glucose (FBG) (<6.0 mmol/L), and a positive correlation between NSE and TGs (<20 mmol/L), systolic blood pressure (75-200 mm Hg), HDL-C (0.75-2.50 mmol/L), diastolic blood pressure (<70 mm Hg) and FBG (6.00-20.00 mmol/L). Furthermore, MS was positively correlated with NSE within the range of 2.00-7.50 ng/mL, but had a negative correlation with NSE within the range of 7.50-23.00 ng/mL.

CONCLUSION

There are associations between NSE with MS and its components. The result suggests that NSE may be a potential predictor of MS. Further research could be conducted in discussing the potential mechanism involved.