The diagnostic values of UCH-L1 in traumatic brain injury: A meta-analysis

Comparing Brain and Blood Lipidome Changes following Single and Repetitive Mild Traumatic Brain Injury in Rats

Traumatic brain injury (TBI) is a major health concern in the United States and globally, contributing to disability and long-term neurological problems. Lipid dysregulation after TBI is underexplored, and a better understanding of lipid turnover and degradation could point to novel biomarker candidates and therapeutic targets. Here, we investigated overlapping lipidome changes in the brain and blood using a data-driven discovery approach to understand lipid alterations in the brain and serum compartments acutely following mild TBI (mTBI) and the potential efflux of brain lipids to peripheral blood. The cortices and sera from male and female Sprague-Dawley rats were analyzed via ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) in both positive and negative ion modes following single and repetitive closed head impacts. The overlapping lipids in the data sets were identified with an in-house data dictionary for investigating lipid class changes. MS-based lipid profiling revealed overall increased changes in the serum compartment, while the brain lipids primarily showed decreased changes. Interestingly, there were prominent alterations in the sphingolipid class in the brain and blood compartments after single and repetitive injury, which may suggest efflux of brain sphingolipids into the blood after TBI. Genetic algorithms were used for predictive panel selection to classify injured and control samples with high sensitivity and specificity. These overlapping lipid panels primarily mapped to the glycerophospholipid metabolism pathway with Benjamini-Hochberg adjusted q-values less than 0.05. Collectively, these results detail overlapping lipidome changes following mTBI in the brain and blood compartments, increasing our understanding of TBI-related lipid dysregulation while identifying novel biomarker candidates.

An overview of mild traumatic brain injuries and emerging therapeutic targets

The majority of traumatic brain injuries (TBIs), approximately 90%, are classified as mild (mTBIs). Globally, an estimated 4 million injuries occur each year from concussions or mTBIs, highlighting their significance as a public health crisis. TBIs can lead to substantial long-term health consequences, including an increased risk of developing Alzheimer's Disease, Parkinson's Disease (PD), chronic traumatic encephalopathy (CTE), and nearly doubling one's risk of suicide. However, the current management of mTBIs in clinical practice and the available treatment options are limited. There exists an unmet need for effective therapy. This review addresses various aspects of mTBIs based on the most up-to-date literature review, with the goal of stimulating translational research to identify new therapeutic targets and improve our understanding of pathogenic mechanisms. First, we provide a summary of mTBI symptomatology and current diagnostic parameters such as the Glasgow Coma Scale (GCS) for classifying mTBIs or concussions, as well as the utility of alternative diagnostic parameters, including imaging techniques like MRI with diffusion tensor imaging (DTI) and serum biomarkers such as S100B, NSE, GFAP, UCH-L1, NFL, and t-tau. Our review highlights several pre-clinical concussion models employed in the study of mTBIs and the underlying cellular mechanisms involved in mTBI-related pathogenesis, including axonal damage, demyelination, inflammation, and oxidative stress. Finally, we examine a selection of new therapeutic targets currently under investigation in pre-clinical models. These targets may hold promise for clinical translation and address the pressing need for more effective treatments for mTBIs.

The game changer: UCH-L1 and GFAP-based blood test as the first marketed in vitro diagnostic test for mild traumatic brain injury

INTRODUCTION

Major organ-based in vitro diagnostic (IVD) tests like ALT/AST for the liver and cardiac troponins for the heart are established, but an approved IVD blood test for the brain has been missing, highlighting a gap in medical diagnostics.

AREAS COVERED

In response to this need, Abbott Diagnostics secured FDA clearance in 2021 for the i-STAT Alinity™, a point-of-care plasma blood test for mild traumatic brain injury (TBI). BioMerieux VIDAS, also approved in Europe, utilizes two brain-derived protein biomarkers: neuronal ubiquitin C-terminal hydrolase-L1 (UCH-L1) and glial fibrillary acidic protein (GFAP). These biomarkers, which are typically present in minimal amounts in healthy individuals, are instrumental in diagnosing mild TBI with potential brain lesions. The study explores how UCH-L1 and GFAP levels increase significantly in the bloodstream following traumatic brain injury, aiding in early and accurate diagnosis.

EXPERT OPINION

The introduction of the i-STAT Alinity™ and the Biomerieux VIDAS TBI blood tests mark a groundbreaking development in TBI diagnosis. It paves the way for the integration of TBI biomarker tools into clinical practice and therapeutic trials, enhancing the precision medicine approach by generating valuable data. This advancement is a critical step in addressing the long-standing gap in brain-related diagnostics and promises to revolutionize the management and treatment of mild TBI.

Raman Spectroscopy Spectral Fingerprints of Biomarkers of Traumatic Brain Injury

Traumatic brain injury (TBI) affects millions of people of all ages around the globe. TBI is notoriously hard to diagnose at the point of care, resulting in incorrect patient management, avoidable death and disability, long-term neurodegenerative complications, and increased costs. It is vital to develop timely, alternative diagnostics for TBI to assist triage and clinical decision-making, complementary to current techniques such as neuroimaging and cognitive assessment. These could deliver rapid, quantitative TBI detection, by obtaining information on biochemical changes from patient's biofluids. If available, this would reduce mis-triage, save healthcare providers costs (both over- and under-triage are expensive) and improve outcomes by guiding early management. Herein, we utilize Raman spectroscopy-based detection to profile a panel of 18 raw (human, animal, and synthetically derived) TBI-indicative biomarkers (N-acetyl-aspartic acid (NAA), Ganglioside, Glutathione (GSH), Neuron Specific Enolase (NSE), Glial Fibrillary Acidic Protein (GFAP), Ubiquitin C-terminal Hydrolase L1 (UCHL1), Cholesterol, D-Serine, Sphingomyelin, Sulfatides, Cardiolipin, Interleukin-6 (IL-6), S100B, Galactocerebroside, Beta-D-(+)-Glucose, Myo-Inositol, Interleukin-18 (IL-18), Neurofilament Light Chain (NFL)) and their aqueous solution. The subsequently derived unique spectral reference library, exploiting four excitation lasers of 514, 633, 785, and 830 nm, will aid the development of rapid, non-destructive, and label-free spectroscopy-based neuro-diagnostic technologies. These biomolecules, released during cellular damage, provide additional means of diagnosing TBI and assessing the severity of injury. The spectroscopic temporal profiles of the studied biofluid neuro-markers are classed according to their acute, sub-acute, and chronic temporal injury phases and we have further generated detailed peak assignment tables for each brain-specific biomolecule within each injury phase. The intensity ratios of significant peaks, yielding the combined unique spectroscopic barcode for each brain-injury marker, are compared to assess variance between lasers, with the smallest variance found for UCHL1 (σ2 = 0.000164) and the highest for sulfatide (σ2 = 0.158). Overall, this work paves the way for defining and setting the most appropriate diagnostic time window for detection following brain injury. Further rapid and specific detection of these biomarkers, from easily accessible biofluids, would not only enable the triage of TBI, predict outcomes, indicate the progress of recovery, and save healthcare providers costs, but also cement the potential of Raman-based spectroscopy as a powerful tool for neurodiagnostics.

Post-mortem detection of neuronal and astroglial biochemical markers in serum and urine for diagnostics of traumatic brain injury

Currently available epidemiological data shows that traumatic brain injury (TBI) represents one of the leading causes of death that is associated with medico-legal practice, including forensic autopsy, criminological investigation, and neuropathological examination. Attention focused on TBI research is needed to advance its diagnostics in ante- and post-mortem cases with regard to identification and validation of novel biomarkers. Recently, several markers of neuronal, astroglial, and axonal injury have been explored in various biofluids to assess the clinical origin, progression, severity, and prognosis of TBI. Despite clinical usefulness, understanding their diagnostic accuracy could also potentially help translate them either into forensic or medico-legal practice, or both. The aim of this study was to evaluate post-mortem pro-BDNF, NSE, UCHL1, GFAP, S100B, SPTAN1, NFL, MAPT, and MBP levels in serum and urine in TBI cases. The study was performed using cases (n = 40) of fatal head injury and control cases (n = 20) of sudden death. Serum and urine were collected within ∼ 24 h after death and compared using ELISA test. In our study, we observed the elevated concentration levels of GFAP and MAPT in both serum and urine, elevated concentration levels of S100B and SPTAN1 in serum, and decreased concentration levels of pro-BDNF in serum compared to the control group. The obtained results anticipate the possible implementation of performed assays as an interesting tool for forensic and medico-legal investigations regarding TBI diagnosis where the head injury was not supposed to be the direct cause of death.

Blood-Based Biomarkers in Traumatic Brain Injury: A Narrative Review With Implications for the Legal System

Traumatic brain injury (TBI) is an increasingly recognized diagnosis with significant, and often costly, associated consequences. Yet, despite their increased recognition, TBIs remain underdiagnosed. This issue is especially prominent in the context of mild TBI (mTBI), where there often exists little to no objective evidence of brain injury. In recent years, considerable effort has been made to better define and interpret known objective markers of TBI, as well as identify and explore new ones. An area of particular interest has focused on research related to blood-based biomarkers of TBI. Advancements in our understanding of TBI-related biomarkers can make it possible to characterize the severity of TBI with greater accuracy, improve our understanding of staging within both the injury process and the recovery process, and help us develop quantifiable metrics representative of reversal and recovery from a brain injury following trauma. Proteomic and non-proteomic blood-based biomarkers are being studied extensively and have shown promise for these purposes. Developments in this realm have significant implications not only for clinical care but also for legislation, as well as civil and criminal litigation. Despite their substantial potential, most of these biomarkers are not yet ready for use within the clinical setting, and therefore, are not appropriate for use within the legal or policy-making systems at this time. Given that existing standardization for the accurate and reliable use of TBI biomarkers is currently insufficient for use within either the clinical or legal realms, such data can be vulnerable to misuse and can even result in the abuse of the legal system for unwarranted gain. Courts will need to carefully evaluate the information presented in their role as gatekeepers of the admissibility of scientific evidence within the legal process. Ultimately, the development of biomarkers should lead to improved clinical care following TBI exposure, coherent and informed laws surrounding TBI, and more accurate and just results in litigation surrounding TBI-related sequelae.

Challenges of the Effectiveness of Traumatic Brain Injuries Biomarkers in the Sports-Related Context

Traumatic brain injury affects 69 million people every year. One of the main limitations in managing TBI patients is the lack of univocal diagnostic criteria, including the absence of standardized assessment methods and guidelines. Computerized axial tomography is the first-choice examination, despite the limited prevalence of positivity; moreover, its performance is undesirable due to the risk of radiological exposure, prolonged stay in emergency departments, inefficient use of resources, high cost, and complexity. Furthermore, immediacy and accuracy in diagnosis and management of TBIs are critically unmet medical needs. Especially in the context of sports-associated TBI, there is a strong need for prognostic indicators to help diagnose and identify at-risk subjects to avoid their returning to play while the brain is still highly vulnerable. Fluid biomarkers may emerge as new prognostic indicators to develop more accurate prediction models, improving risk stratification and clinical decision making. This review describes the current understanding of the cellular sources, temporal profile, and potential utility of leading and emerging blood-based protein biomarkers of TBI; its focus is on biomarkers that could improve the management of mild TBI cases and can be measured readily and directly in the field, as in the case of sports-related contexts.

Monitoring of Post-Brain Injuries By Measuring Plasma Levels of Neuron-Derived Extracellular Vesicles

BACKGROUND

Extracellular vesicles (EV) released from neurons into the blood can reflect the state of nervous tissue. Measurement of neuron derived EV (NDE) may serve as an indicator of brain injury.

METHODS

A sandwich immunoassay was established to measure plasma NDE using anti-neuron CD171 and anti-EV CD9 ([CD171 ⁺ CD9⁺]). Plasma samples were obtained from commercial sources, cross-country (n = 9), football (n = 22), soccer (n = 19), and rugby (n = 18) athletes over time. Plasma was also collected from patients undergoing total aortic arch replacement (TAR) with selective cerebral perfusion during cardiopulmonary bypass before and after surgery (n = 36).

RESULTS

The specificity, linearity, and reproducibility of NDE assay (measurement of [CD171 ⁺ CD9⁺]) were confirmed. By scanning electron microscopy and nanoparticle tracking, spherical vesicles ranging in size from 150 to 300 nm were confirmed. Plasma levels of NDE were widely spread over 2 to 3 logs in different individuals with a significant age-dependent decrease. However, NDE were very stable in each individual within a ± 50% change over time (cross-country, football, soccer), whereas rugby players were more variable over 4 years. In patients undergoing TAR, NDE increased rapidly in days post-surgery and were significantly (P = .0004) higher in those developing postoperative delirium (POD) (n = 13) than non-delirium patients (n = 23).

CONCLUSIONS

The blood test to determine plasma levels of NDE was established by a sandwich immunoassay using 2 antibodies against neuron (CD171) and exosomes (CD9). NDE levels varied widely in different individuals and decreased with age, indicating that NDE levels should be considered as a normalizer of NDE biomarker studies. However, NDE levels were stable over time in each individual, and increased rapidly after TAR with greater increases associated with patients developing POD. This assay may serve as a surrogate for evaluating and monitoring brain injuries.

The prognostic significance of biomarkers in cerebrospinal fluid following severe traumatic brain injury: a systematic review and meta-analysis

After severe traumatic brain injury (sTBI) proteins, neurotrophic factors and inflammatory markers are released into the biofluids. This review and meta-analysis searched the literature for prognostic candidate cerebrospinal fluid markers and their relation to sTBI patient outcome. A systematic search of the literature was carried out across PubMed, EMBASE, PubMed Central (PMC), and Cochrane Central Library. Biomarker concentrations were related to the Glasgow Outcome Scale dichotomized into favorable and unfavorable outcomes. When a biomarker was reported in ≥ 3 studies, it was included in meta-analysis. The search returned 1527 articles. After full-text analysis, 54 articles were included, 34 from the search, and 20 from the reference lists. Of 9 biomarkers, 8 were significantly different compared to controls (IL-4, IL-6, IL-8, IL-10, TNFα, sFas, BDNF, and cortisol). Of these, 5 were significantly increased in sTBI patients with unfavorable outcome (IL-6, IL-8, IL-10, TNFα, and cortisol), compared to patients with favorable outcome. This review demonstrated a correlation between 5 biomarkers and clinical outcome in sTBI patients. The paucity of included studies, however, makes it difficult to extrapolate further on this finding.

Blood Biomarkers in Brain Injury Medicine

Purpose of Review

This review seeks to explore blood-based biomarkers with the potential for clinical implementation.

Recent Findings

Emerging non-proteomic biomarkers hold promise for more accurate diagnostic and prognostic capabilities, especially in the subacute to chronic phase of TBI recovery. Further, there is a growing understanding of the overlap between TBI-related and Dementia-related blood biomarkers.

Summary

Given the significant heterogeneity inherent in the clinical diagnosis of Traumatic Brain Injury (TBI), there has been an exponential increase in TBI-related biomarker research over the past two decades. While TBI-related biomarker assessments include both cerebrospinal fluid analysis and advanced neuroimaging modalities, blood-based biomarkers hold the most promise to be non-invasive biomarkers widely available to Brain Injury Medicine clinicians in diverse practice settings. In this article, we review the most relevant blood biomarkers for the field of Brain Injury Medicine, including both proteomic and non-proteomic blood biomarkers, biomarkers of cerebral microvascular injury, and biomarkers that overlap between TBI and Dementia.

Evaluation of rest-activity cycles in patients with severe acquired brain injury: an observational study

BACKGROUND

There is little knowledge about rest-activity cycles (RAC) in patients with severe-acquired brain injury (sABI) during early in-hospital rehabilitation. This study aimed to investigate if patients with sABI displayed unconsolidated RACs at the beginning of in-hospital rehabilitation, and how these changed over time.

METHODS

This study was a prospective observational study. All patients consecutively admitted to one ward were screened for eligibility. We recorded accelerometric activity for 20 days. The Daytime Activity Ratio (DAR) of activity between daytime (7-22) and the total activity during the entire day was calculated and used to estimate consolidation.

RESULTS

Fifty-five patients were screened and 20 patients were included. Complete day 1 & 2 data was obtained on 18 patients. Fifty-six percentage of these had a consolidated RAC at the beginning of rehabilitation. On day 19 & 20, complete data could be obtained from 15 patients, 80% of these had consolidation of RAC. When comparing these a significant mean increase of 5.8% 95%CI(0.52; 11.01) in DAR was found p < .05, and the model of all data also showed a significant increase in median DAR over time p < .01.

CONCLUSION

RAC consolidation improves over time in patients admitted for in-hospital early neurorehabilitation.

The expression and clinical value of ubiquitin carboxyl-terminal hydrolase L1 in the blood of neonates with hypoxic ischemic encephalopathy

BACKGROUND

Neonatal hypoxic ischemic encephalopathy (HIE) can result in mental retardation due to the associated brain damage. Early identification of brain injury is vital for the prevention and treatment of brain damage in neonates. This study investigated the expression levels of serum ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) in neonates with HIE and its correlation with brain damage.

METHODS

From January 2019 to December 2020, 56 cases of neonatal patients with HIE were selected as the observation group, and 60 cases of healthy newborns delivered in our hospital during the same period were selected as the control group. Blood samples were obtained from neonates and the serum expression of UCH-L1 was detected by enzyme-linked immunosorbent assays (ELISAs). The relationship between UCH-L1 and neonatal prognosis and clinical features was analyzed.

RESULTS

Compared with the healthy control group, the serum levels of UCH-L1 in the observation group was significantly higher (2.28±1.21 vs. 0.81±0.39 ng/mL, P=0.000). Furthermore, at 6 hours after birth, the serum levels of UCH-L1 were significantly higher in neonates with moderate to severe HIE compared to patients with mild HIE (2.92±0.80 and 1.76±0.72 ng/mL, respectively, P=0.000). Pearson correlation analysis showed that the expression levels of UCH-L1 were negatively correlated with the development quotient (DQ), intelligence index (MI), and the Neonatal Behavioral Neurological Assessment (NBNA) score of HIE newborns (P<0.05).

CONCLUSIONS

The level of UCH-L1 protein expression is elevated in the serum of newborns with HIE, and this may have a certain clinical value in predicting the intelligence of children.

Characterization of Cerebrospinal Fluid Ubiquitin C-Terminal Hydrolase L1 as a Biomarker of Human Acute Traumatic Spinal Cord Injury

A major obstacle for translational research in acute spinal cord injury (SCI) is the lack of biomarkers that can objectively stratify injury severity and predict outcome. Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a neuron-specific enzyme that shows promise as a diagnostic biomarker in traumatic brain injury (TBI), but has not been studied in SCI. In this study, cerebrospinal fluid (CSF) and serum samples were collected over the first 72-96 h post-injury from 32 acute SCI patients who were followed prospectively to determine neurological outcomes at 6 months post-injury. UCH-L1 concentration was measured using the Quanterix Simoa platform (Quanterix, Billerica, MA) and correlated to injury severity, time, and neurological recovery. We found that CSF UCH-L1 was significantly elevated by 10- to 100-fold over laminectomy controls in an injury severity- and time-dependent manner. Twenty-four-hour post-injury CSF UCH-L1 concentrations distinguished between American Spinal Injury Association Impairment Scale (AIS) A and AIS B, and AIS A and AIS C patients in the acute setting, and predicted who would remain "motor complete" (AIS A/B) at 6 months with a sensitivity of 100% and a specificity of 86%. AIS A patients who did not improve their AIS grade at 6 months post-injury were characterized by sustained elevations in CSF UCH-L1 up to 96 h. Similarly, the failure to gain >8 points on the total motor score at 6 months post-injury was associated with higher 24-h CSF UCH-L1. Unfortunately, serum UCH-L1 levels were not informative about injury severity or outcome. In conclusion, CSF UCH-L1 in acute SCI shows promise as a biomarker to reflect injury severity and predict outcome.

Study protocol for investigating the performance of an automated blood test measuring GFAP and UCH-L1 in a prospective observational cohort of patients with mild traumatic brain injury: European BRAINI study

INTRODUCTION

Mild traumatic brain injury (mTBI) is a common cause of clinical consultation in the emergency department. Patients with mTBI may undergo brain CT scans based on clinical criteria. However, the proportion of patients with brain lesions on CT is very low. Two serum biomarkers, glial fibrillar acidic protein (GFAP) and ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), have been shown to discriminate patients regarding the presence or absence of brain lesions on initial CT scan when assessed within the first 12 hours after TBI. However, the current technique for measuring serum concentrations of GFAP and UCH-L1 is manual and time consuming, which may hinder its use in routine clinical practice. This study assesses the diagnostic accuracy of an automated assay for the measurement of serum GFAP and UCH-L1 in a cohort of patients with mTBI who received a CT scan as the standard of care.

METHODS AND ANALYSIS

This is a prospective multicentre observational study of 1760 patients with mTBI recruited in France and Spain across 16 participating sites. Adult patients with an initial Glasgow Coma Scale score of 13-15 and a brain CT scan underwent blood sampling within 12 hours after TBI. The primary outcome measure is the diagnostic performance of an automated assay measuring serum concentrations of GFAP and UCH-L1 for discriminating between patients with positive and negative findings on brain CT-scans. Secondary outcome measures include the performance of these two biomarkers in predicting the neurological status and quality of life at 1 week and 3 months after the trauma.

ETHICS AND DISSEMINATION

Ethics approval was obtained by the Institutional Review Board of Sud-Ouest Outre Mer III in France (Re#2019-A01525-52) and Hospital 12 de Octubre in Spain (Re#19/322). The results will be presented at scientific meetings and published in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT04032509.

Blood-Based Markers of Neuronal Injury in Adult-Onset Myotonic Dystrophy Type 1

INTRODUCTION

The present study had four aims. First, neuronal injury markers, including neurofilament light (NF-L), total tau, glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase (UCH-L1), were compared between individuals with and without adult-onset myotonic dystrophy type 1 (DM1). Second, the impact of age and CTG repeat on brain injury markers was evaluated. Third, change in brain injury markers across the study period was quantified. Fourth, associations between brain injury markers and cerebral white matter (WM) fractional anisotropy (FA) were identified.

METHODS

Yearly assessments, encompassing blood draws and diffusion tensor imaging on a 3T scanner, were conducted on three occasions. Neuronal injury markers were quantified using single molecule array (Simoa).

RESULTS

The sample included 53 patients and 70 controls. NF-L was higher in DM1 patients than controls, with individuals in the premanifest phases of DM1 (PreDM1) exhibiting intermediate levels ( χ ( 2 ) 2 = 38.142, P < 0.001). Total tau was lower in DM1 patients than controls (Estimate = -0.62, 95% confidence interval [CI] -0.95: -0.28, P < 0.001), while GFAP was elevated in PreDM1 only (Estimate = 30.37, 95% CI 10.56:50.19, P = 0.003). Plasma concentrations of UCH-L1 did not differ between groups. The age by CTG interaction predicted NF-L: patients with higher estimated progenitor allelege length (ePAL) had higher NF-L at a younger age, relative to patients with lower CTG repeat; however, the latter exhibited faster age-related change (Estimate = -0.0021, 95% CI -0.0042: -0.0001, P = 0.045). None of the markers changed substantially over the study period. Finally, cerebral WM FA was significantly associated with NF-L (Estimate = -42.86, 95% CI -82.70: -3.02, P = 0.035).

INTERPRETATION

While NF-L appears sensitive to disease onset and severity, its utility as a marker of progression remains to be determined. The tau assay may have low sensitivity to tau pathology associated with DM1.

Pro-inflammatory cytokines, but not brain- and extracellular matrix-derived proteins, are increased in the plasma following electrically induced kindling of seizures

Background

The aim of the study was to evaluate the brain-derived proteins, extracellular matrix-derived protein and cytokines as potential peripheral biomarkers of different susceptibility to seizure development in an animal model of epilepsy evoked by chronic focal electrical stimulation of the brain.

Methods

The plasma levels of IL-1β (interleukin 1β), IL-6 (interleukin 6), UCH-L1 (ubiquitin C-terminal hydrolase 1), MMP-9 (matrix metalloproteinase 9), and GFAP (glial fibrillary acidic protein) were assessed. The peripheral concentrations of the selected proteins were analyzed according to the status of kindling and seizure severity parameters. In our study, increased concentrations of plasma IL-1β and IL-6 were observed in rats subjected to hippocampal kindling compared to sham-operated rats.

Results

Animals that developed tonic–clonic seizures after the last stimulation had higher plasma concentrations of IL-1β and IL-6 than sham-operated rats and rats that did not develop seizure. Elevated levels of IL-1β and IL-6 were observed in rats that presented more severe seizures after the last five stimulations compared to sham-operated animals. A correlation between plasma IL-1β and IL-6 concentrations was also found. On the other hand, the plasma levels of the brain-derived proteins UCH-L1, MMP-9, and GFAP were unaffected by kindling status and seizure severity parameters.

Conclusions

The plasma concentrations of IL-1β and IL-6 may have potential utility as peripheral biomarkers of immune system activation in the course of epilepsy and translational potential for future clinical use. Surprisingly, markers of cell and nerve ending damage (GFAP, UCH-L1 and MMP-9) may have limited utility.

Analysis of Clinical Related Factors of Neonatal Hand-Foot-Mouth Disease Complicated With Encephalitis

Objective: To explore the clinical related factors of neonatal hand-foot-mouth disease (HFMD) complicated with encephalitis.

Method: The neonatal HFMD complicated with encephalitis treated in our hospital from July 2015 to July 2020 was taken as the object of study. According to the NBNA score at discharge, the patients were divided into normal group and abnormal group. The clinical symptoms, auxiliary examination and prognosis of the two groups were compared.

Result: (1) General condition: there was no significant difference in sex, age, duration of fever, treatment time and etiological test between the two groups (P > 0.05). (2) Clinical symptoms and signs: there was significant difference in abnormal consciousness between the two groups (P < 0.05). However, there was no significant difference in skin rash, respiratory system symptoms, digestive system symptoms, signs of high intracranial pressure, increased muscle tone and weakening of primitive reflex (P > 0.05). (3) Auxiliary examination: the number of white blood cells and the level of cytokines (CK-BB, UCH-L1) in cerebrospinal fluid (CSF) in the group with abnormal NBNA score were significantly higher than those in the group with normal NBNA score (P < 0.05). The serum IgM level in the abnormal NBNA score group was higher than that in the normal NBNA score group, and the serum IgG level in the abnormal NBNA score group was lower than that in the normal NBNA score group, and the difference was statistically significant (P < 0.05). The abnormal rate of Craniocerebral MRI in abnormal NBNA score group was higher than that in normal NBNA score group, and there was significant difference between the two groups (P < 0.05). There was no significant difference in the levels of protein, sugar, chloride, lactate dehydrogenase, and MMP-9 in CSF and the abnormal rate of amplitude integrated EEG (aEEG) between the two groups (P > 0.05). (4) The prognoses of patients with normal and abnormal NBNA score are good, and there are not significantly differences in the prognosis between the two groups (P > 0.05).

Conclusion: (1) Neonatal HFMD complicated with encephalitis occurs more than 10 days after birth, there is no obvious abnormality in male and female, the vast majority of newborns have febrile symptoms, rash is not its specific manifestation, and most of them are atypical. (2) The positive rate of HFMD-related virus detected in CSF of neonatal HFMD is high. For newborns with abnormal consciousness, CSF examination should be accomplished in time, which has certain clinical significance for early diagnosis and treatment of severe newborns. (3) The increase of white blood cell count and cytokines (CK-BB, UCH-L1) in CSF of neonatal HFMD complicated with encephalitis has a certain clinical reference value for early diagnosis and identification of severe newborns. (4) There is a certain humoral immune disorder in newborns with HFMD complicated with encephalitis, but the overall prognosis is better due to the protective effect of maternal IgG.

Diagnosing mild traumatic brain injury using saliva RNA compared to cognitive and balance testing

BACKGROUND

Early, accurate diagnosis of mild traumatic brain injury (mTBI) can improve clinical outcomes for patients, but mTBI remains difficult to diagnose because of reliance on subjective symptom reports. An objective biomarker could increase diagnostic accuracy and improve clinical outcomes. The aim of this study was to assess the ability of salivary noncoding RNA (ncRNA) to serve as a diagnostic adjunct to current clinical tools. We hypothesized that saliva ncRNA levels would demonstrate comparable accuracy for identifying mTBI as measures of symptom burden, neurocognition, and balance.

METHODS

This case-control study involved 538 individuals. Participants included 251 individuals with mTBI, enrolled ≤14 days postinjury, from 11 clinical sites. Saliva samples (n = 679) were collected at five time points (≤3, 4-7, 8-14, 15-30, and 31-60 days post-mTBI). Levels of ncRNAs (microRNAs, small nucleolar RNAs, and piwi-interacting RNAs) were quantified within each sample using RNA sequencing. The first sample from each mTBI participant was compared to saliva samples from 287 controls. Samples were divided into testing (n = 430; mTBI = 201 and control = 239) and training sets (n = 108; mTBI = 50 and control = 58). The test set was used to identify ncRNA diagnostic candidates and create a diagnostic model. Model accuracy was assessed in the naïve test set.

RESULTS

A model utilizing seven ncRNA ratios, along with participant age and chronic headache status, differentiated mTBI and control participants with a cross-validated area under the curve (AUC) of .857 in the training set (95% CI, .816-.903) and .823 in the naïve test set. In a subset of participants (n = 321; mTBI = 176 and control = 145) assessed for symptom burden (Post-Concussion Symptom Scale), as well as neurocognition and balance (ClearEdge System), these clinical measures yielded cross-validated AUC of .835 (95% CI, .782-.880) and .853 (95% CI, .803-.899), respectively. A model employing symptom burden and four neurocognitive measures identified mTBI participants with similar AUC (.888; CI, .845-.925) as symptom burden and four ncRNAs (.932; 95% CI, .890-.965).

CONCLUSION

Salivary ncRNA levels represent a noninvasive, biologic measure that can aid objective, accurate diagnosis of mTBI.

Biomarkers in traumatic brain injury: new concepts

Traumatic brain injury is a multifaceted condition that encompasses a spectrum of injuries: contusions, axonal injuries in specific brain regions, edema, and hemorrhage. Brain injury determines a broad clinical and disability spectrum due to the implication of various cellular pathways, genetic phenotypes, and environmental factors. It is challenging to predict patient outcomes, to appropriately evaluate the patients, to determine a suitable treatment strategy and rehabilitation program, and to communicate with patient relatives. Biomarkers detected from body fluids are potential evaluation tools for traumatic brain injury patients. These may serve as internal indicators of cerebral damage, delivering valuable information about the dynamic cellular, biochemical, and molecular environments. The diagnostic and prognostic value of biomarkers tested both in animal models of traumatic brain injury is still under question, despite a considerable scientific literature. Recent publications emphasize that a more realistic approach involves combining multiple types of biomarkers with other investigative tools (imaging, outcome scales, and genetic polymorphisms). Additionally, there is increasing interest in the use of biomarkers as tools for treatment monitoring and as surrogate outcome variables to facilitate the design of distinct randomized controlled trials. This review highlights the latest available evidence regarding biomarkers in adults after traumatic brain injury and discusses new approaches in the evaluation of this patient group.

Assessment of Long-Term Effects of Sports-Related Concussions: Biological Mechanisms and Exosomal Biomarkers

Concussion or mild traumatic brain injury (mTBI) in athletes can cause persistent symptoms, known as post-concussion syndrome (PCS), and repeated injuries may increase the long-term risk for an athlete to develop neurodegenerative diseases such as chronic traumatic encephalopathy (CTE), and Alzheimer's disease (AD). The Center for Disease Control estimates that up to 3.8 million sport-related mTBI are reported each year in the United States. Despite the magnitude of the phenomenon, there is a current lack of comprehensive prognostic indicators and research has shown that available monitoring tools are moderately sensitive to short-term concussion effects but less sensitive to long-term consequences. The overall aim of this review is to discuss novel, quantitative, and objective measurements that can predict long-term outcomes following repeated sports-related mTBIs. The specific objectives were (1) to provide an overview of the current clinical and biomechanical tools available to health practitioners to ensure recovery after mTBIs, (2) to synthesize potential biological mechanisms in animal models underlying the long-term adverse consequences of mTBIs, (3) to discuss the possible link between repeated mTBI and neurodegenerative diseases, and (4) to discuss the current knowledge about fluid biomarkers for mTBIs with a focus on novel exosomal biomarkers. The conclusions from this review are that current post-concussion clinical tests are not sufficiently sensitive to injury and do not accurately quantify post-concussion alterations associated with repeated mTBIs. In the current review, it is proposed that current practices should be amended to include a repeated symptom inventory, a cognitive assessment of executive function and impulse control, an instrumented assessment of balance, vestibulo-ocular assessments, and an improved panel of blood or exosome biomarkers.

UCH-L1 is a Poor Serum Biomarker of Murine Traumatic Brain Injury After Polytrauma

BACKGROUND

Several serum biomarkers have been studied to diagnose incidence and severity of traumatic brain injury (TBI), but a reliable biomarker in TBI has yet to be identified. Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) has been proposed as a biomarker in clinical and preclinical studies, largely in the setting of isolated TBI or concussion. The aim of this study was to evaluate the performance of UCH-L1 as a serum biomarker in the setting of polytrauma and TBI.

METHODS

Multiple variations of murine TBI and polytrauma models were used to evaluate serum biomarkers. The different models included TBI with and without hemorrhagic shock and resuscitation, isolated extremity vascular ligation, extremity ischemia/reperfusion, and blunt tail injury. Blood was drawn at intervals after injury, and serum levels of neuron-specific enolase, UCH-L1, creatine kinase, and syndecan-1 were evaluated by enzyme-linked immunosorbent assay.

RESULTS

UCH-L1 levels were not significantly different between TBI, tail injury, and sham TBI. By contrast, neuron-specific enolase levels were increased in TBI mice compared with tail injury and sham TBI mice. UCH-L1 levels increased regardless of TBI status at 30 min and 4 h after hemorrhagic shock and resuscitation. In mice that underwent femoral artery cannulation followed by hemorrhagic shock/resuscitation, UCH-L1 levels were significantly elevated compared with shock sham mice at 4 h (3158 ± 2168 pg/mL, 4 h shock versus 0 ± 0 pg/mL, 4 h shock sham; P < 0.01) and at 24 h (3253 ± 2954 pg/mL, 24 h shock versus 324 ± 482 pg/mL, 24 h shock sham; P = 0.03). No differences were observed in UCH-L1 levels between the sham shock and the arterial ligation, vein ligation, or extremity ischemia/reperfusion groups at any time point. Similar to UCH-L1, creatine kinase was elevated only after shock compared with sham mice at 4, 24, and 72 h after injury.

CONCLUSIONS

Our study demonstrates that UCH-L1 is not a specific marker for TBI but is elevated in models that induce central and peripheral nerve ischemia. Given the increase in UCH-L1 levels observed after hemorrhagic shock, we propose that UCH-L1 may be a useful adjunct in quantifying severity of shock or global ischemia rather than as a specific marker of TBI.

Stability of Blood Biomarkers of Traumatic Brain Injury

Blood biomarker tests were recently approved for clinical diagnosis of traumatic brain injury (TBI), yet there are still fundamental questions that need attention. One such question is the stability of putative biomarkers in blood over the course of several days after injury if the sample is unable to be processed into serum or plasma and stored at low temperatures. Blood may not be able to be stored at ultra-low temperatures in austere combat or sports environments. In this prospective study of 20 adult patients with positive head computed tomography imaging findings, the stability of three biomarkers (glial fibrillary acidic protein [GFAP], ubiquitin C-terminal hydrolase-L1 [UCH-L1], and S100 calcium binding protein B [S100B]) in whole blood and in serum stored at 4-5°C was evaluated over the course of 72 h after blood collection. The amount of time whole blood and serum were refrigerated had no significant effect on GFAP concentration in plasma obtained from whole blood and in serum (p = 0.6256 and p = 0.3687, respectively), UCH-L1 concentration in plasma obtained from whole blood and in serum (p = 0.0611 and p = 0.5189, respectively), and S100B concentration in serum (p = 0.4663). Concentration levels of GFAP, UCH-L1, and S100B in blood collected from patients with TBI were found to be stable at 4-5°C for at least 3 days after blood draw. This study suggests that the levels of the three diagnostic markers above are still valid for diagnostic TBI tests if the sample is stored in 4-5°C refrigerated conditions.

The Importance of Therapeutic Time Window in the Treatment of Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of death and disability. Despite its importance in public health, there are presently no drugs to treat TBI. Many reasons underlie why drugs have failed clinical trials, one reason is that most drugs to treat TBI lose much of their efficacy before patients are first treated. This review discusses the importance of therapeutic time window; the time interval between TBI onset and the initiation of treatment. Therapeutic time window is complex, as brain injury is both acute and chronic, resulting in multiple drug targets that appear and disappear with differing kinetics. The speed and increasing complexity of TBI pathophysiology is a major reason why drugs lose efficacy as time to first dose increases. Recent Phase III clinical trials treated moderate to severe TBI patients within 4–8 h after injury, yet they turned away many potential patients who could not be treated within these time windows. Additionally, most head trauma is mild TBI. Unlike moderate to severe TBI, patients with mild TBI often delay treatment until their symptoms do not abate. Thus, drugs to treat moderate to severe TBI likely will need to retain high efficacy for up to 12 h after injury; drugs for mild TBI, however, will likely need even longer windows. Early pathological events following TBI progress with similar kinetics in humans and animal TBI models suggesting that preclinical testing of time windows assists the design of clinical trials. We reviewed preclinical studies of drugs first dosed later than 4 h after injury. This review showed that therapeutic time window can differ depending upon the animal TBI model and the outcome measure. We identify the few drugs (methamphetamine, melanocortin, minocycline plus N-acetylcysteine, and cycloserine) that demonstrated good therapeutic windows with multiple outcome measures. On the basis of their therapeutic window, these drugs appear to be excellent candidates for clinical trials. In addition to further testing of these drugs, we recommend that the assessment of therapeutic time window with multiple outcome measures becomes a standard component of preclinical drug testing.

Serum vitamin D deficiency in subjects with severe acquired brain injury and relationship with functional severity

BACKGROUND

Vitamin D may be important for the development and function of the nervous system. Low serum vitamin D levels have been detected in several neurological diseases.

OBJECTIVE

To ascertain the relationship between 25(OH)D serum level and disability in subjects with severe acquired brain injury (sABI).

DESIGN

Prospective cross-sectional study Methods: Consecutive subjects with sABI admitted to neuro-rehabilitation were enrolled. A sample of subjects from the neurological ward was considered the control group. Vitamin D serum levels and blood parameters were measured at admission. Disability Rating Scale (DRS), Glasgow Outcome Scale (GOS), and Level of Cognitive Functioning (LCF) were used in assessing disability.

RESULTS

A total of 104 subjects (34 F, 70 M; mean age 53.9 ± 15.2 years) were enrolled: 54 (19 F, 35 M) with sABI and 50 (15 F, 35 M) subjects as control group. Deficient mean serum levels of vitamin D (19.2 ± 9.4 ng/mL) were detected in the subjects with sABI and a significant inverse correlation between vitamin D serum levels and DRS score was detected (p = 0.04).

CONCLUSION

Subjects with sABI showed vitamin D deficiency that might correlate to disability severity. The reason is unclear and might represent a secondary phenomenon resulting from the inflammatory process.