Comparison of the performances of copeptin and multiple biomarkers in long-term prognosis of severe traumatic brain injury

Prognostic Value of Blood-Based Protein Biomarkers in Traumatic Brain Injury: A Living Systematic Review and Meta-Analysis

Circulating biomarkers might improve the prediction of outcomes in patients with traumatic brain injury (TBI) beyond current approaches. Robust and up-to-date evidence is required to support their clinical utility and integration into medical practice to guide decision-making. Our objective was to critically appraise the existing evidence for six core blood-based TBI biomarkers (S100 calcium-binding protein B, glial fibrillary acidic protein [GFAP], neuron-specific enolase, ubiquitin C-terminal hydrolase-L1 [UCH-L1], tau and neurofilament proteins), in predicting outcome after TBI. Electronic databases, including Medline and Embase, were searched for articles published from their inception to October 2023. Studies were included if they evaluated the accuracy of blood biomarker concentrations at hospital presentation for outcome prediction in adult patients with TBI. Outcomes assessed were mortality, Glasgow Outcome Scale (GOS)/GOS extended (GOS-E), or the Rivermead Post-Concussion Symptoms Questionnaire (RPQ). Study selection, data extraction, and quality assessment using the modified Quality Assessment of Prognostic Accuracy Studies tool were performed by two authors independently, with disagreements being resolved through discussion or arbitration. If appropriate, a meta-analysis was conducted by calculating the weighted summary area under the curve (AUC) and using a bivariate regression model. Of 12,792 retrieved records, 32 articles, including 7481 patients with TBI, were selected as relevant. Two biomarkers showed strong associations with in-hospital and 6-month mortality: GFAP (unadjusted pooled AUC 0.81 [95% confidence interval [CI] 0.75-0.87] and 0.82 [0.80-0.85], respectively) and UCH-L1 (0.80 [0.74-0.85] and 0.83 [0.77-0.88]). Their addition to models that included established risk factors consistently improved the predictive value, though models and performance varied substantially across studies. In four studies measuring both markers, UCH-L1 outperformed GFAP in improving risk stratification when added to established prediction models. At ∼1.5 ng/mL (five studies), the summary sensitivity of GFAP for predicting mortality was 78% (95% CI 67-85%), and the summary specificity was 79% (95% CI 64-89%). The other assessed biomarkers had fair to good performance in mortality prediction with unclear added benefits. Neurofilament light (NfL) (three studies) demonstrated the strongest association in predicting a 6-month poor outcome (GOS-E ≤4; GOS ≤3) (unadjusted pooled AUC 0.81 [95% CI 0.75-0.87]), whereas the other assessed biomarkers had a fair performance with unclear or irrelevant added value. All core biomarkers had only marginal or no association with incomplete recovery and post-concussion symptoms/syndrome, as assessed by RPQ. Serious problems were found in the design and analysis of many of the studies. We conclude that admission measurements of core blood TBI biomarkers, in particular GFAP and UCH-L1, are strongly associated with mortality. There remains little evidence that any of these markers are ready for clinical implementation for prognostic purposes. Future work focused on the intended use and applying unbiased rigorous analysis methods is necessary to demonstrate that the biomarker test results are "prognostically actionable."

Diagnostic and prognostic performance of urine ubiquitin carboxy-terminal hydrolase L1 across multiple acute brain injury types - A longitudinal prospective cohort study

Introduction

Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) is recognized as a diagnostic and prognostic blood biomarker for traumatic brain injury (TBI). This study aimed to evaluate whether UCH-L1 concentrations measured in patients' urine post-injury could serve as a diagnostic or prognostic biomarker for outcomes in various types of acute brain injuries (ABI).

Material and methods

This pilot study included 46 ABI patients: aneurysmal subarachnoid hemorrhage (n = 22), ischemic stroke (n = 16), and traumatic brain injury (n = 8), along with three healthy controls. Urine samples were collected at early (1.50 ± 0.70 days) and late (9.17 ± 3.40 days) periods post-admission. UCH-L1 and creatinine levels were quantified using ELISA. UCH-L1 concentrations were compared to functional outcomes (modified Rankin Scale, mRS) and dichotomized into favorable (mRS 0-3) and unfavorable (mRS 4-6) groups. Non-parametric statistical tests and ROC analysis was performed.

Results

UCH-L1 concentrations in healthy controls were significantly lower compared to both early and late samples after ABI (p ≤ 0.001). The diagnostic performance of urine UCH-L1 at early timepoint showed excellent discriminatory ability, with AUC of 97.6% (95% CI: 93.0-100, p = 0.006 (sensitivity 98%, specificity 100%). Urine UCH-L1 concentrations, both with and without creatinine normalization, did not distinguish between favorable and unfavorable outcomes in either early (p = 0.88 and p = 0.36) or late samples (p = 0.98 and p = 0.30) in any types of ABI.

Discussion and conclusions

Although UCH-L1 concentrations in urine did not differentiate between favorable and unfavorable outcomes, a significant difference was observed between healthy subjects and ABI patients. This finding underscores the significant diagnostic utility of urine UCH-L1 concentrations, regardless of the type of acute brain injury.

Systemic Inflammatory Effect of Hypobaria During Aeromedical Evacuation after Porcine Traumatic Brain Injury

BACKGROUND

Traumatic brain injury (TBI)-related morbidity is caused largely by secondary injury resulting from hypoxia, excessive sympathetic drive, and uncontrolled inflammation. Aeromedical evacuation (AE) is used by the military for transport of wounded soldiers to higher levels of care. We hypothesized that the hypobaric, hypoxic conditions of AE may exacerbate uncontrolled inflammation after TBI that could contribute to more severe TBI-related secondary injury.

STUDY DESIGN

Thirty-six female pigs were used to test TBI vs Sham TBI, hypoxia vs normoxia, and hypobaria vs ground conditions. TBI was induced by controlled cortical injury, hypobaric conditions of 12,000 ft were established in an altitude chamber, and hypoxic exposure was titrated to 85% SpO 2 while at altitude. Serum cytokines, ubiquitin C-terminal hydrolase L1, and TBI biomarkers were analyzed via ELISA. Gross analysis and staining of cortex and hippocampus tissue was completed for glial fibrillary acidic protein and phosphorylated tau.

RESULTS

Serum interleukin-1β, interleukin-6, and tumor necrosis factor-α were significantly elevated after TBI in pigs exposed to altitude-induced hypobaria/hypoxia, as well as hypobaria alone, compared with ground level/normoxia. No difference in TBI biomarkers after TBI or hypobaric, hypoxic exposure was noted. No difference in brain tissue glial fibrillary acidic protein or phosphorylated tau when comparing the most different conditions of Sham TBI + ground or normoxia with the TBI + hypobaria/hypoxia group was noted.

CONCLUSIONS

The hypobaric environment of AE induces systemic inflammation after TBI. Severe inflammation may play a role in exacerbating secondary injury associated with TBI and contribute to worse neurocognitive outcomes. Measures should be taken to minimize barometric and oxygenation changes during AE after TBI.

Surviving septic patients endotyped with a functional assay demonstrate active immune responses

Introduction

Sepsis is a complex clinical syndrome characterized by a heterogenous host immune response. Historically, static protein and transcriptomic metrics have been employed to describe the underlying biology. Here, we tested the hypothesis that ex vivo functional TNF expression as well as an immunologic endotype based on both IFNγ and TNF expression could be used to model clinical outcomes in sepsis patients.

Methods

This prospective, observational study of patient samples collected from the SPIES consortium included patients at five health systems enrolled over 17 months, with 46 healthy control patients, 68 ICU patients without sepsis, and 107 ICU patients with sepsis. Whole blood was collected on day 1, 4, and 7 of ICU admission. Outcomes included in-hospital and 180-day mortality and non-favorable discharge disposition defined by skilled nursing facility, long-term acute care facility, or hospice. Whole blood ELISpot assays were conducted to quantify TNF expression [stimulated by lipopolysaccharide (LPS)] and IFNγ expression (stimulated by anti-CD3/CD28 mAb), which were then used for assignment to one of four subgroups including an 'immunocompetent', 'immunosuppressed endotype', and two 'mixed' endotypes.

Results

Whole blood TNF spot-forming units were significantly increased in septic and CINS patients on days 4 and 7 compared to healthy subjects. In contrast, TNF expression per cell on days 1, 4, and 7 was significantly lower in both septic and critically ill non-septic (CINS) patients compared to healthy subjects. Early increases in total TNF expression were associated with favorable discharge disposition and lower in-hospital mortality. 'Immunocompetent' endotype patients on day 1 had a higher proportion of favorable to non-favorable discharges compared to the 'immunosuppressed' endotype. Similarly, 'immunocompetent' endotype patients on day 4 had a higher in-hospital survival compared to the 'immunosuppressed' endotype patients. Finally, among septic patients, decreased total TNF and IFNγ expression were associated with 180-day mortality.

Conclusions

Increased ex vivo whole blood TNF expression is associated with improved clinical outcomes. Further, the early 'immunocompetent' endotype is associated with favorable discharge and improved in-hospital and 180-day survival. The ability to functionally stratify septic patients based on blood cell function ex vivo may allow for identification of future immune modulating therapies.

Copeptin's role in traumatic brain injury: The promising quest for a new biomarker

OBJECTIVE

Traumatic brain injury (TBI) necessitates reliable biomarkers to improve patient care. This study explored copeptin as a potential biomarker in TBI and its relation to vasopressin (ADH) in such patients.

METHODS

A cross-sectional study was conducted on 50 TBI patients. Exclusion criteria included specific medical conditions and recent traumatic events. Copeptin and ADH testing were performed within 30 days post-trauma. Patient data, Glasgow Coma Scale (GCS) scores, imaging results, and the need for surgical intervention were obtained from medical charts.

RESULTS

Copeptin levels negatively correlated with GCS scores (ρ = - 0.313, p = 0.027), indicating a potential association with trauma severity. Copeptin levels (mean: 3.22 pmol/L, median 2.027 pmol/L, SD = 3.15) tended to be lower than those found in the normal population, suggesting possible neuroendocrine dysfunction post-TBI. ADH levels (mean: 67.93 pmol/L, median 56.474 pmol/L SD = 47.67) were higher than the normal range and associated with the need for surgery (p = 0.048). Surprisingly, copeptin and ADH levels negatively correlated (r = - 0.491; p < 0.001), potentially due to differences in degradation processes and physiological variations in TBI patients.

CONCLUSION

Copeptin shows potential as a predictive biomarker for assessing TBI severity and predicting patient outcome. However, its complex relationship with ADH in TBI requires further investigation. Careful interpretation is needed due to potential variations in excretion dynamics and metabolism. Larger studies on TBI patient cohorts are essential to validate copeptin as a reliable biomarker and improve patient care in TBI.

Association of early dexmedetomidine exposure with brain injury biomarker levels following moderate - Severe traumatic brain injury: A TRACK-TBI study

BACKGROUND

Traumatic brain injury (TBI) triggers autonomic dysfunction and inflammatory response that can result in secondary brain injuries. Dexmedetomidine is an alpha-2 agonist that may modulate autonomic function and inflammation and has been increasingly used as a sedative agent for critically ill TBI patients. We aimed to investigate the association between early dexmedetomidine exposure and blood-based biomarker levels in moderate-to-severe TBI (msTBI).

METHODS

We conducted a retrospective cohort study using data from the Transforming Clinical Research and Knowledge in Traumatic Brain Injury Study (TRACK-TBI), which enrolled acute TBI patients prospectively across 18 United States Level 1 trauma centers between 2014-2018. Our study population focused on adults with msTBI defined by Glasgow Coma Scale score 3-12 after resuscitation, who required mechanical ventilation and sedation within the first 48 h of ICU admission. The study's exposure was early dexmedetomidine utilization (within the first 48 h of admission). Primary outcome included brain injury biomarker levels measured from circulating blood on day 3 following injury, including glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase-L1 (UCH-L1), neuron-specific enolase (NSE), S100 calcium-binding protein B (S100B) and the inflammatory biomarker C-reactive protein (CRP). Secondary outcomes assessed biomarker levels on days 5 and 14. Linear mixed-effects regression modelling of the log-transformed response variable was used to analyze the association of early dexmedetomidine exposure with brain injury biomarker levels.

RESULTS

Among the 352 TRACK-TBI subjects that met inclusion criteria, 50 (14.2 %) were exposed to early dexmedetomidine, predominantly male (78 %), white (81 %), and non-Hispanic (81 %), with mean age of 39.8 years. Motor vehicle collisions (27 %) and falls (22 %) were common causes of injury. No significant associations were found between early dexmedetomidine exposure with day 3 brain injury biomarker levels (GFAP, ratio = 1.46, 95 % confidence interval [0.90, 2.34], P = 0.12; UCH-L1; ratio = 1.17 [0.89, 1.53], P = 0.26; NSE, ratio = 1.19 [0.92, 1.53], P = 0.19; S100B, ratio = 1.01 [0.95, 1.06], P = 0.82; hs-CRP, ratio = 1.29 [0.91, 1.83], P = 0.15). The hs-CRP level at day 14 in the dexmedetomidine group was higher than that of the non-exposure group (ratio = 1.62 [1.12, 2.35], P = 0.012).

CONCLUSIONS

There were no significant associations between early dexmedetomidine exposure and day 3 brain injury biomarkers in msTBI. Our findings suggest that early dexmedetomidine use is not correlated with either decrease or increase in brain injury biomarkers following msTBI. Further research is necessary to confirm these findings.

A systematic review and meta-analysis of major blood protein biomarkers that predict unfavorable outcomes in severe traumatic brain injury

INTRODUCTION

Severe traumatic brain injury (TBI) presentation and late clinical outcomes are usually evaluated by the Glasgow Outcome Scale-Extended (GOS-E), which lacks strong prognostic predictability. Several blood biomarkers have been linked to TBI, such as Tau, GFAP, UCH-L1, S-100B, and NSE. Clinical values of TBI biomarkers have yet to be evaluated in a focused multi-study meta-analysis. We reviewed relevant articles evaluating potential relationships between TBI biomarkers and both early and 6-month outcomes.

METHODS

All PubMed article publications from January 2000 to November 2023 with the search criteria "Protein Biomarker" AND "Traumatic Brain Injury" were included. Amongst all comparative studies, the sensitivity means and range values of biomarkers in predicting CT Rotterdam scores, ICU admission in the early period, or predicting GOS-E < 4 at the 6-month period were calculated from confusion matrices. Sensitivity values were modeled for each biomarker across studies and compared statistically for heterogeneity and differences.

RESULTS

From the 65 articles that met the criteria, 13 were included in this study. Six articles involved early-period TBI outcomes and seven involved 6-month outcomes. In the early period TBI outcomes, GFAP had a superior sensitivity to UCH-L1 and S-100B, and similar sensitivity to the CT Rotterdam score. In the 6-month period TBI outcomes, total Tau and NSE both had significant interstudy heterogeneity, making them inferior to GFAP, phosphorylated Tau, UCH-L1, and S-100B, all four of which had similar sensitivities at 75 %. This sensitivity range at 6-month outcomes was still relatively inferior to the CT Rotterdam score. Total Tau did not show any prognostic advantage at six months with GOS-E < 4, and phosphorylated Tau was similar in its sensitivity to other biomarkers such as GFAP and UCH-L1 and still inferior to the CT Rotterdam score.

CONCLUSION

This data suggests that TBI protein biomarkers do not possess better prognostic value with regards to outcomes.

Navigating the Complexities of Traumatic Encephalopathy Syndrome (TES): Current State and Future Challenges

Chronic traumatic encephalopathy (CTE) is a unique neurodegenerative disease that is associated with repetitive head impacts (RHI) in both civilian and military settings. In 2014, the research criteria for the clinical manifestation of CTE, traumatic encephalopathy syndrome (TES), were proposed to improve the clinical identification and understanding of the complex neuropathological phenomena underlying CTE. This review provides a comprehensive overview of the current understanding of the neuropathological and clinical features of CTE, proposed biomarkers of traumatic brain injury (TBI) in both research and clinical settings, and a range of treatments based on previous preclinical and clinical research studies. Due to the heterogeneity of TBI, there is no universally agreed-upon serum, CSF, or neuroimaging marker for its diagnosis. However, as our understanding of this complex disease continues to evolve, it is likely that there will be more robust, early diagnostic methods and effective clinical treatments. This is especially important given the increasing evidence of a correlation between TBI and neurodegenerative conditions, such as Alzheimer's disease and CTE. As public awareness of these conditions grows, it is imperative to prioritize both basic and clinical research, as well as the implementation of necessary safe and preventative measures.

Copeptin: a novel prognostic biomarker in trauma: a review article

BACKGROUND

Trauma has a significant impact on the overall health of individuals worldwide, being a leading cause of morbidity and mortality with long-lasting effects. The identification of suitable biomarkers is crucial to predict patient outcomes, providing information about the severity of a condition or the probability of a specific outcome. Hence, in this study, we addressed a new biomarker, copeptin, and discussed its prognostic roles in various trauma researches.

MAIN BODY

Copeptin is a peptide derived from the precursor of the hormone vasopressin, which is released in response to stress. Copeptin can serve as a valuable biomarker for determining the severity, prognosis, and outcome of trauma patients. Elevated levels of copeptin are associated with increased mortality and poor clinical outcomes in patients with severe injuries or bleeding. Implementing copeptin measurements in clinical practice can enable healthcare providers to more accurately gauge the degree of trauma and predict patient mortality and morbidity outcomes facilitating prompt interventions and personalized treatment.

CONCLUSION

The measurement of novel biomarker copeptin can serve as a prognostic molecule for further outcomes in trauma patients. Nevertheless, supplementary research is needed to fully comprehend its role in the development and progression of traumatic injuries.

Prognostic significance of serum annexin A7 in severe traumatic brain injury: A prospective longitudinal cohort study

BACKGROUND

Annexin A7 (ANXA7) may have the potential to exacerbate brain injury. Our purpose was to investigate the role of serum ANXA7 as a biomarker of severity and prognosis after severe traumatic brain injury (sTBI).

METHODS

In this prospective cohort study, we consecutively enrolled 102 sTBI patients and 102 controls and measured their serum ANXA7 concentrations. Post-trauma 180-day poor prognosis was considered as extended Glasgow outcome scale score 1-4.

RESULTS

Significantly increased serum ANXA7 concentrations of sTBI patients, as compared to controls (median, 74.1 vs 8.0 ng/ml; P < 0.001), had independent correlation with Rotterdam computed tomography score (t = 3.251, P = 0.002) and Glasgow coma scale score (t = -2.253, P = 0.027), as well as serum ANXA7 concentrations > 74.1 ng/ml were independently predictive of 180-day overall survival (hazard ratio, 3.356; 95 % confidence interval (CI), 1.233-9.138; P = 0.018), and poor prognosis (OR: 3.558; 95 % CI, 1.264-10.015; P = 0.016). Serum ANXA7 concentrations were of significant efficiency for discriminating risks of mortality (area under receiver operating curve (AUC), 0.808; 95 % CI; 0.718-0.879) and poor prognosis (AUC, 0.772; 95 % CI; 0.678-0.849). Moreover, its AUC was in range of Glasgow coma scale score and Rotterdam computed tomography score (all P > 0.05) CONCLUSIONS: Increased serum ANXA7 concentrations, in close relation to severity, were independently associated with prognosis, indicating that serum ANXA7 may represent a clinically valuable biomarker of sTBI.

Association Between Copeptin and Six-Month Neurologic Outcomes in Patients With Moderate Traumatic Brain Injury

Background

Copeptin has been reported as a predictive biomarker for the prognosis after traumatic brain injury (TBI). However, most of them were in patients with severe TBI and limited value in predicting outcomes in patients with moderate TBI defined as Glasgow Coma Scale (GCS) score from 9 to 12. We aimed to investigate the predictive value of copeptin in assessing the neurologic outcome following moderate TBI.

Methods

Patients were prospectively enrolled between May 2017 and November 2020. We consecutively measured plasma copeptin within 24 h after trauma, days 3, 5, and 7 using ELISA. The primary outcome was to correlate plasma copeptin levels with poor neurologic outcome at 6 months after moderate TBI. The secondary outcome was to compare the prognostic accuracy of copeptin and C-reactive protein (CRP) in assessing the outcome of patient.

Results

A total of 70 patients were included for the final analysis. The results showed that 29 patients (41.4%) experienced a poor neurologic outcome at 6 months. Multivariable logistic regression analysis revealed that increased copeptin (odds ration [OR] = 1.020, 95% CI: 1.005–1.036), GCS score of 9 or 10 (OR = 4.507, 95% CI: 1.266–16.047), and significant abnormal findings on CT (OR = 4.770; 95% CI: 1.133–20.076) were independent risk factors for poor outcomes. Consecutive plasma copeptin levels were significantly different according to outcomes (p < 0.001). Copeptin on day 7 exhibited better prognostic performance than CRP with an area under receiver operating characteristic curve (AUROC) difference of 0.179 (95% CI: 0.032–0.325) in predicting 6-month poor outcomes.

Conclusion

Plasma copeptin level can be a useful marker in predicting 6-month outcomes in patients with moderate TBI.

Vasopressin and Breathing: Review of Evidence for Respiratory Effects of the Antidiuretic Hormone

Vasopressin (AVP) is a key neurohormone involved in the regulation of body functions. Due to its urine-concentrating effect in the kidneys, it is often referred to as antidiuretic hormone. Besides its antidiuretic renal effects, AVP is a potent neurohormone involved in the regulation of arterial blood pressure, sympathetic activity, baroreflex sensitivity, glucose homeostasis, release of glucocorticoids and catecholamines, stress response, anxiety, memory, and behavior. Vasopressin is synthesized in the paraventricular (PVN) and supraoptic nuclei (SON) of the hypothalamus and released into the circulation from the posterior lobe of the pituitary gland together with a C-terminal fragment of pro-vasopressin, known as copeptin. Additionally, vasopressinergic neurons project from the hypothalamus to the brainstem nuclei. Increased release of AVP into the circulation and elevated levels of its surrogate marker copeptin are found in pulmonary diseases, arterial hypertension, heart failure, obstructive sleep apnoea, severe infections, COVID-19 due to SARS-CoV-2 infection, and brain injuries. All these conditions are usually accompanied by respiratory disturbances. The main stimuli that trigger AVP release include hyperosmolality, hypovolemia, hypotension, hypoxia, hypoglycemia, strenuous exercise, and angiotensin II (Ang II) and the same stimuli are known to affect pulmonary ventilation. In this light, we hypothesize that increased AVP release and changes in ventilation are not coincidental, but that the neurohormone contributes to the regulation of the respiratory system by fine-tuning of breathing in order to restore homeostasis. We discuss evidence in support of this presumption. Specifically, vasopressinergic neurons innervate the brainstem nuclei involved in the control of respiration. Moreover, vasopressin V1a receptors (V1aRs) are expressed on neurons in the respiratory centers of the brainstem, in the circumventricular organs (CVOs) that lack a blood-brain barrier, and on the chemosensitive type I cells in the carotid bodies. Finally, peripheral and central administrations of AVP or antagonists of V1aRs increase/decrease phrenic nerve activity and pulmonary ventilation in a site-specific manner. Altogether, the findings discussed in this review strongly argue for the hypothesis that vasopressin affects ventilation both as a blood-borne neurohormone and as a neurotransmitter within the central nervous system.

Role of copeptin in the diagnosis of traumatic neuroendocrine dysfunction

Traumatic neuroendocrine dysfunction may present with diabetes insipidus (DI) or with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Both these pathologies involve a disturbance in the antidiuretic hormone (ADH) secretion, causing dysnatremias. Diagnosis of posttraumatic ADH dysfunction is hampered by technical difficulties in ADH assessment, and relies mostly on non-specific serum sodium, serum and urine osmolality and diuresis, often leading to misdiagnosis in the acute care setting. Research now focuses on the diagnostic role of copeptin, a peptide secreted together with ADH in an equimolar fashion, and which can be accurately evaluated. Recent studies identified cut-off values of 2.6 pmol/L for baseline copeptin and of 4.9 and 3.8 pmol/L for hypertonic saline infusion and arginine infusion stimulated copeptin, respectively, for the diagnosis of DI in patients with polyuria-polydipsia syndrome. Although SIADH is more difficult to be explored due to its heterogeneity, a ratio of copeptin to urinary sodium below 30 pmol/mmol identifies euvolemic hyponatremia. Exploring the role of copeptin assessment in patients with traumatic brain injury (TBI) in the acute phase may improve their diagnosis accuracy, management and outcome.

Copeptin combined with National Early Warning Score for predicting survival in elderly critical ill patients at emergency department

OBJECTIVE

Copeptin, reflecting vasopressin release, as well as the National Early Warning Score (NEWS), reflecting the severity of critical illness, might qualify for survival prediction in elderly patients with critical illness. This prospective observational study aims at assessing the predictive value of copeptin combined with NEWS on the prognosis of elderly critical ill patients at emergency department (ED).

METHODS

We analyzed serum copeptin levels and the NEWS at admission to the ED in a prospective, single-center, and observational study comprising 205 elderly patients with critical illness. Death within 30 days after admission to the ED was the primary end point.

RESULTS

The serum copeptin levels and the NEWS in the non-survivor patients group were higher than those in the survivor group [30.35 (14.20, 38.91) vs 17.53 (13.01, 25.20), P = 0.001 and 9.0 (7.0-10.0) vs 7.0 (6.0-8.0), P = 0.001]. Multivariate logistic regression analysis showed that copeptin, NEWS and copeptin combined with NEWS were all independent risk factors for 30-day mortality in elderly patients with critical illness. Copeptin, NEWS and copeptin combined with NEWS all performed well in predicting 30-day survival, with area under the ROC curve (AUC) values of 0.766 (95%CI, 0.702-0.822), 0.797 (95%CI, 0.744-0.877) and 0.854 (95%CI, 0.798-0.899) respectively. Using the Z test to compare the areas under the above three curves, copeptin combined with NEWS showed a higher predictive value for 30-day survival (P < 0.05). As we calculated, the optimal cut-off values of copeptin and NEWS using the Youden index were 19.78 pg/mL and 8.5 points, respectively. Risk stratification analysis showed that patients with both copeptin levels higher than 19.78 pg/mL and NEWS points higher than 8.5 points had the highest risk of death.

CONCLUSIONS

Copeptin combined with NEWS have a stronger predictive power on the prognosis of elderly patients with critical illness at ED, comparing to either factor individually.

Permeability of the Blood-Brain Barrier after Traumatic Brain Injury; Radiological Considerations

Traumatic brain injury (TBI) is a leading cause of death and disability, especially in young persons, and constitutes a major socioeconomic burden worldwide. It is regarded as the leading cause of mortality and morbidity in previously healthy young persons. Most of the mechanisms underpinning the development of secondary brain injury are consequences of disruption of the complex relationship between the cells and proteins constituting the neurovascular unit or a direct result of loss of integrity of the tight junctions (TJ) in the blood-brain barrier (BBB). A number of changes have been described in the BBB after TBI, including loss of TJ proteins, pericyte loss and migration, and altered expressions of water channel proteins at astrocyte end-feet processes. There is a growing research interest in identifying optimal biological and radiological biomarkers of severity of BBB dysfunction and its effects on outcomes after TBI. This review explores the microscopic changes occurring at the neurovascular unit, after TBI, and current radiological adjuncts for its evaluation in pre-clinical and clinical practice.

Thorough overview of ubiquitin C-terminal hydrolase-L1 and glial fibrillary acidic protein as tandem biomarkers recently cleared by US Food and Drug Administration for the evaluation of intracranial injuries among patients with traumatic brain injury

Traumatic brain injury (TBI) is a major cause of mortality and morbidity affecting all ages. It remains to be a diagnostic and therapeutic challenge, in which, to date, there is no Food and Drug Administration‐approved drug for treating patients suffering from TBI. The heterogeneity of the disease and the associated complex pathophysiology make it difficult to assess the level of the trauma and to predict the clinical outcome. Current injury severity assessment relies primarily on the Glasgow Coma Scale score or through neuroimaging, including magnetic resonance imaging and computed tomography scans. Nevertheless, such approaches have certain limitations when it comes to accuracy and cost efficiency, as well as exposing patients to unnecessary radiation. Consequently, extensive research work has been carried out to improve the diagnostic accuracy of TBI, especially in mild injuries, because they are often difficult to diagnose. The need for accurate and objective diagnostic measures led to the discovery of biomarkers significantly associated with TBI. Among the most well‐characterized biomarkers are ubiquitin C‐terminal hydrolase‐L1 and glial fibrillary acidic protein. The current review presents an overview regarding the structure and function of these distinctive protein biomarkers, along with their clinical significance that led to their approval by the US Food and Drug Administration to evaluate mild TBI in patients.

The diagnosis and prognostic value of plasma copeptin in traumatic brain injury: a systematic review and meta-analysis

OBJECTIVE

The purpose of this meta-analysis was to assess the diagnosis and prognostic value of plasma copeptin levels after traumatic brain injury (TBI).

METHODS

The databases PubMed, Cochrane Library, OvidSP, Google Scholar, VIP, CNKI, and WFSD were systematically searched from the inception dates to May 9, 2020. The pooled analysis of relevant data was conducted by the RevMan 5.3 software. Subgroups analysis was performed to explore the impact of age, country, male ratio, follow-up time, and Glasgow coma score (GCS) on the pooled area under curve (AUC) values of assessment mortality.

RESULTS

A total of 17 studies involving 2654 participants were included in the current meta-analysis. The pooled results demonstrated that increased plasma copeptin levels were significantly associated with TBI [SMD, 2.44; 95%CI, 1.59 ~ 3.29; P < 0.00001] and also were significantly associated with mortality [SMD, 1.37; 95%CI, 1.16 ~ 1.58; P < 0.00001], and poor functional outcomes (PFO) [SMD, 1.44; 95%CI, 1.20 ~ 1.68; P < 0.00001] in patients with TBI. Furthermore, the copeptin had a significant value in diagnosing brain concussion [AUC, 0.90; 95%CI, 0.84 ~ 0.95; P < 0.00001] and predicting progressive hemorrhagic injury [AUC, 0.83; 95%CI, 0.80 ~ 0.87; P < 0.00001], acute traumatic coagulopathy [AUC, 0.84; 95%CI, 0.79 ~ 0.89; P < 0.00001], mortality [AUC, 0.89; 95%CI, 0.87 ~ 0.92; P < 0.00001], and PFO [AUC, 0.88; 95%CI, 0.84 ~ 0.92; P < 0.00001] in patients with TBI. The subgroup analysis findings suggested that the age, country, male ratio, follow-up time, and GCS were not obvious factors influencing the pooled AUC values of assessment mortality.

CONCLUSIONS

The authors indicate that the plasma copeptin is a potentially promising biomarker for TBI diagnosis and prognosis prediction.

Predictive Value and Correlation of Neuron-Specific Enolase for Prognosis in Patients with Coma: A Systematic Review and Meta-Analysis

OBJECTIVE

Coma is the most serious disturbance of consciousness, which affects the life quality of patients and increases the burden of their family. Studies to assess the prognostic value of neuron-specific enolase (NSE) in patients with coma have not led to precise, generally accepted prognostic rules. The study aims to assess the correlation between NSE and prognosis of coma and the predictive value of NSE for clinical prognosis.

METHODS

A search was conducted using PubMed, Web of Science, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), and WanFang Data from the establishment time of databases to December 2019. This analysis included patients with coma, regardless of how long the coma was. In total, 26 articles were retrieved and included in the review.

RESULTS

The meta-analysis revealed the NSE concentration of patients with coma is significantly higher than that of the control group (standard mean difference = 0.88, 95% confidence interval [CI]: 0.63-1.12, p < 0.05). The pooled sensitivity and specificity of NSE in coma diagnosis was 0.5 (95% CI: 0.39-0.61) and 0.86 (95% CI: 0.71-0.94).

CONCLUSIONS

The NSE concentration of patients with poor coma prognosis is significantly higher than that of the control group. The high NSE concentration is not necessarily a poor prognosis for coma, but low NSE concentration indicates a high probability of a good prognosis for coma.

Prognostic Value of Glial Fibrillary Acidic Protein in Patients With Moderate and Severe Traumatic Brain Injury: A Systematic Review and Meta-Analysis

OBJECTIVES

Biomarkers have been suggested as potential prognostic predictors following a moderate or severe traumatic brain injury but their prognostic accuracy is still uncertain. The objective of this systematic review is to assess the ability of the glial fibrillary acidic protein to predict prognosis in patients with moderate or severe traumatic brain injury.

DATA SOURCES

MEDLINE, Embase, CENTRAL, and BIOSIS electronic databases and conference abstracts, bibliographies of selected studies, and narrative reviews were searched.

STUDY SELECTION

Pairs of reviewers identified eligible studies. Cohort studies including greater than or equal to four patients with moderate or severe traumatic brain injury and reporting glial fibrillary acidic protein levels according to the outcomes of interest, namely Glasgow Outcome Scale or Extended Glasgow Outcome Scale, and mortality, were eligible.

DATA EXTRACTION

Pairs of reviewers independently extracted data from the selected studies using a standardized case report form. Mean levels were log-transformed, and their differences were pooled with random effect models. Results are presented as geometric mean ratios. Methodologic quality, risk of bias, and applicability concerns of the included studies were assessed.

DATA SYNTHESIS

Seven-thousand seven-hundred sixty-five citations were retrieved of which 15 studies were included in the systematic review (n = 1,070), and nine were included in the meta-analysis (n = 701). We found significant associations between glial fibrillary acidic protein serum levels and Glasgow Outcome Scale score less than or equal to 3 or Extended Glasgow Outcome Scale score less than or equal to 4 (six studies: geometric mean ratio 4.98 [95% CI, 2.19-11.13]; I = 94%) and between mortality (seven studies: geometric mean ratio 8.13 [95% CI, 3.89-17.00]; I = 99%).

CONCLUSIONS

Serum glial fibrillary acidic protein levels were significantly higher in patients with an unfavorable prognosis. Glial fibrillary acidic protein has a potential for clinical bedside use in helping for prognostic assessment. Further research should focus on multimodal approaches including tissue biomarkers for prognostic evaluation in critically ill patients with traumatic brain injury.

Profiling biomarkers of traumatic axonal injury: From mouse to man

Traumatic brain injury (TBI) poses a major public health problem on a global scale. Its burden results from high mortality and significant morbidity in survivors. This stems, in part, from an ongoing inadequacy in diagnostic and prognostic indicators despite significant technological advances. Traumatic axonal injury (TAI) is a key driver of the ongoing pathological process following TBI, causing chronic neurological deficits and disability. The science underpinning biomarkers of TAI has been a subject of many reviews in recent literature. However, in this review we provide a comprehensive account of biomarkers from animal models to clinical studies, bridging the gap between experimental science and clinical medicine. We have discussed pathogenesis, temporal kinetics, relationships to neuro-imaging, and, most importantly, clinical applicability in order to provide a holistic perspective of how this could improve TBI diagnosis and predict clinical outcome in a real-life setting. We conclude that early and reliable identification of axonal injury post-TBI with the help of body fluid biomarkers could enhance current care of TBI patients by (i) increasing speed and accuracy of diagnosis, (ii) providing invaluable prognostic information, (iii) allow efficient allocation of rehabilitation services, and (iv) provide potential therapeutic targets. The optimal model for assessing TAI is likely to involve multiple components, including several blood biomarkers and neuro-imaging modalities, at different time points.

Neuroglobin as a Novel Biomarker for Predicting Poor Outcomes in Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Neuroglobin (Ngb) has a high affinity for oxygen and helps prevent hypoxic-ischemic brain damage. In this study we analyzed the relationship between Ngb levels and clinical outcomes of aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

Serum Ngb levels were measured in 58 patients with aSAH and 27 control individuals using the enzyme-linked immunosorbent assay. To continuously assess aSAH, we measured serum Ngb levels on days 1, 2, 3, 5, and 7 after aSAH. Clinical data were collected using the Hunt and Hess Scale, the Glasgow Coma Scale (GCS), the World Federation of Neurological Surgeons (WFNS) Scale, and the modified Fisher Scale. Clinical outcomes included 6-month mortality and 6-month unfavorable outcomes (modified Rankin Scale (mRS) score of 3-6).

RESULTS

Serum Ngb levels increased after aSAH, peaked on day 2, and then gradually decreased. Serum Ngb levels on admission were higher in the patient group than in the control group (7.67 ± 2.56 ng/mL vs. 6.45 ± 0.88 ng/mL, P < 0.05). Multivariate logistic regression analysis indicated that serum Ngb levels on day 2 after aSAH were independently related to 6-month mortality (odds ratio [OR] = 0.265, 95% confidence interval [CI] = 0.094-0.747, P < 0.05) and 6-month unfavorable outcomes (OR = 1.919, 95% CI = 1.158-3.180, P < 0.05), and receiver operating characteristic curve analysis showed that serum Ngb levels on day 2 predicted 6-month mortality and 6-month unfavorable outcomes, with areas under the curve of 0.893 (P < 0.05; 95% CI, 0.812-0.974) and 0.818 (P < 0.05; 95% CI, 0.691-0.954), respectively, based on the best thresholds.

CONCLUSIONS

Serum Ngb levels on day 2 after aSAH were strongly associated with poor outcomes in aSAH, suggesting that Ngb may be a novel biomarker for predicting poor outcomes in aSAH.

An update on diagnostic and prognostic biomarkers for traumatic brain injury

INTRODUCTION

Traumatic brain injury (TBI) is a major worldwide neurological disorder of epidemic proportions. To date, there are still no FDA-approved therapies to treat any forms of TBI. Encouragingly, there are emerging data showing that biofluid-based TBI biomarker tests have the potential to diagnose the presence of TBI of different severities including concussion, and to predict outcome. Areas covered: The authors provide an update on the current knowledge of TBI biomarkers, including protein biomarkers for neuronal cell body injury (UCH-L1, NSE), astroglial injury (GFAP, S100B), neuronal cell death (αII-spectrin breakdown products), axonal injury (NF proteins), white matter injury (MBP), post-injury neurodegeneration (total Tau and phospho-Tau), post-injury autoimmune response (brain antigen-targeting autoantibodies), and other emerging non-protein biomarkers. The authors discuss biomarker evidence in TBI diagnosis, outcome prognosis and possible identification of post-TBI neurodegernative diseases (e.g. chronic traumatic encephalopathy and Alzheimer's disease), and as theranostic tools in pre-clinical and clinical settings. Expert commentary: A spectrum of biomarkers is now at or near the stage of formal clinical validation of their diagnostic and prognostic utilities in the management of TBI of varied severities including concussions. TBI biomarkers could serve as a theranostic tool in facilitating drug development and treatment monitoring.

Comparison of plasma copeptin and multiple biomarkers for assessing prognosis of patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

Increased plasma copeptin concentrations are related to poor prognosis after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to assess prognostic significance of plasma copeptin detection compared with glial fibrillary astrocyte protein, myelin basic protein, S100B, phosphorylated axonal neurofilament subunit H, neuron-specific enolase, tau and ubiquitin carboxyl-terminal hydrolase L1 in aSAH.

METHODS

We detected plasma concentrations of the aforementioned biomarkers in 105 healthy controls using ELISA. Their predictive ability for symptomatic cerebral vasospasm and 6-month poor outcome (Glasgow Outcome Scale score of 1-3) were compared.

RESULTS

Plasma concentrations of the preceding biomarkers were highly correlated with World Federation of Neurological Surgeons subarachnoid hemorrhage scale (WFNS) scores as well as were significantly higher in patients with symptomatic cerebral vasospasm than in those without symptomatic cerebral vasospasm and in patients with poor outcome than in those with good outcome. In terms of area under receiver operating characteristic curve, their predictive value for symptomatic cerebral vasospasm and 6-month poor outcome was in the range of WFNS scores. Plasma copeptin concentration, but not plasma concentrations of other biomarkers, statistically significantly improved the predictive performance of WFNS scores.

CONCLUSIONS

Copeptin in plasma might have the potential to be a useful prognostic biomarker for aSAH.

Correlation of tenascin-C concentrations in serum with outcome of traumatic brain injury in humans

BACKGROUND

Tenascin-C, a matricellular protein, is involved in brain injury. However, change of tenascin-C concentrations in peripheral blood remains unknown after traumatic brain injury (TBI).

METHODS

Serum tenascin-C concentrations were measured in 100 healthy controls, 108 severe TBI patients, 79 moderate TBI patients and 32 mild TBI patients.

RESULTS

Serum tenascin-C concentrations of patients were significantly higher than those of controls. Tenascin-C concentrations negatively correlated with Glasgow Coma Scale (GCS) scores in all patients (r=-0.658, P<0.001). In severe TBI patients, tenascin-C in serum significantly discriminated patients at risk of 6-month mortality (area under curve, 0.821; 95% confidence interval, 0.735-0.888) and poor outcome (Glasgow Outcome Scale score of 1-3) (area under curve, 0.833; 95% confidence interval, 0.749-0.898) and emerged as an independent predictor for 6-month mortality (odds ratio, 1.114; 95% confidence interval, 1.008-1.233; P=0.005), overall survival (hazard ratio, 1.085; 95% confidence interval, 1.010-1.166; P=0.003) and unfavorable outcome (odds ratio, 1.049; 95% confidence interval, 1.014-1.076; P=0.001). By receiver-operating characteristic analysis, serum tenascin-C concentrations had similar prognostic value compared with GCS scores.

CONCLUSIONS

Enhanced serum tenascin-C concentrations are closely related to trauma severity and clinical outcomes, substantializing tenascin-C as a potential prognostic biomarker after TBI.

Serum periostin concentrations and outcomes after severe traumatic brain injury

BACKGROUND

Periostin, a neurite outgrowth-promoting factor, is increasingly expressed in rat brain tissues after cerebral ischemia or subarachnoid hemorrhage. However, periostin concentrations are undetermined in peripheral blood from patients with traumatic brain injury (TBI).

METHODS

In this prospective, observational study, serum periostin concentrations were measured in 130 controls and 130 severe TBI patients. We investigated its association with trauma severity reflected by Glasgow Coma Scale (GCS) score and prognosis (i.e., 30-day mortality and 30-day overall survival).

RESULTS

As compared with the controls, serum periostin concentrations were significantly increased in the patients [(median, 246.5ng/ml; interquartile range, 164.5-328.6ng/ml) vs. (median, 61.8ng/ml; interquartile range, 37.9-77.9ng/ml), P<0.001]. Periostin concentrations independently correlated with GCS scores (t=-6.199, P<0.001). Serum periostin concentrations higher than 308.2ng/ml predicted 30-day mortality with a sensitivity of 72.4% and a specificity of 78.2% [area under curve, 815; 95% confidence interval (CI), 0.737-0.878]. Periostin concentrations higher than 246.5ng/ml were independently related to 30-day mortality and 30-day overall survival with odds ratio value of 3.829 (95% CI, 1.104-13.281) and hazard ratio value of 5.667 (95% CI, 1.953-16.443) respectively.

CONCLUSIONS

Increased serum periostin concentrations clearly reflect trauma severity and mortality following TBI.

Predictive value of neuron-specific enolase for prognosis in patients with moderate or severe traumatic brain injury: a systematic review and meta-analysis

BACKGROUND

Prognosis is difficult to establish early after moderate or severe traumatic brain injury despite representing an important concern for patients, families and medical teams. Biomarkers, such as neuron-specific enolase, have been proposed as potential early prognostic indicators. Our objective was to determine the association between neuron-specific enolase and clinical outcomes, and the prognostic value of neuron-specific enolase after a moderate or severe traumatic brain injury.

METHODS

We searched MEDLINE, Embase, The Cochrane Library and Biosis Previews, and reviewed reference lists of eligible articles to identify studies. We included cohort studies and randomized controlled trials that evaluated the prognostic value of neuron-specific enolase to predict mortality or Glasgow Outcome Scale score in patients with moderate or severe traumatic brain injury. Two reviewers independently collected data. The pooled mean differences were analyzed using random-effects models. We assessed risk of bias using a customized Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Subgroup and sensitivity analyses were performed based on a priori hypotheses.

RESULTS

We screened 5026 citations from which 30 studies (involving 1321 participants) met our eligibility criteria. We found a significant positive association between neuron-specific enolase serum levels and mortality (10 studies, n = 474; mean difference [MD] 18.46 µg/L, 95% confidence interval [CI] 10.81 to 26.11 µg/L; I2 = 83%) and a Glasgow Outcome Scale ≤ 3 (14 studies, n = 603; MD 17.25 µg/L, 95% CI 11.42 to 23.07 µg/L; I2 = 82%). We were unable to determine a clinical threshold value using the available patient data.

INTERPRETATION

In patients with moderate or severe traumatic brain injury, increased neuron-specific enolase serum levels are associated with unfavourable outcomes. The optimal neuron-specific enolase threshold value to predict unfavourable prognosis remains unknown and clinical decision-making is currently not recommended until additional studies are made available.

Serum soluble CD40 ligand levels after acute intracerebral hemorrhage

BACKGROUND

Soluble CD40 ligand (sCD40L) is associated with inflammation. This study aimed to assess the prognostic value of sCD40L for clinical outcomes of acute intracerebral hemorrhage (ICH) patients.

MATERIALS AND METHODS

The serum sCD40L levels of 110 patients and 110 age- and gender-matched healthy controls were measured using sandwich immunoassays. The relationships between serum sCD40L levels and 1-week mortality, 6-month mortality, 6-month overall survival, 6-month unfavorable outcome (modified Rankin Scale score >2), and ICH severity including hematoma volume and National Institutes of Health Stroke Scale (NIHSS) score were assessed using multivariate analysis.

RESULTS

Compared with healthy controls, ICH patients had higher serum sCD40L levels. Serum sCD40L levels were correlated positively with hematoma volumes and NIHSS scores using a multivariate linear regression. Multivariate analysis results indicated that sCD40L was identified an independent predictor of 1-week mortality, 6-month mortality, 6-month unfavorable outcome and 6-month overall survival. sCD40L also showed high predictive performances for 1-week mortality, 6-month mortality and 6-month unfavorable outcome based on receiver operating characteristic curve.

CONCLUSIONS

Elevated serum sCD40L levels are independently associated with ICH severity and clinical outcomes. And sCD40L has potential to be a good prognostic biomarker of ICH.

Thioredoxin as a marker for severity and prognosis of aneurysmal subarachnoid hemorrhage

OBJECTIVE

Circulating levels of thioredoxin (Trx), a potent anti-oxidant that modulates inflammation, cell growth and apoptosis, are increased in various critical care conditions. The purpose of this study was to establish the relationship between serum Trx levels and prognosis of aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

An enzyme-linked immunosorbent assay measurement of Trx was performed in serum from 132 patients and 132 healthy volunteers. Clinical outcomes included 6-month mortality and unfavorable outcome (Glasgow outcome scale score of 1-3).

RESULTS

The serum Trx levels were significantly higher in patients than in controls (23.4±12.2 ng/mL vs.8.5±4.0 ng/mL, P<0.001) and had close relation to the World Federation of Neurological Surgeons (WFNS) scores (r=0.461, P<0.001) and modified Fisher scores (r=0.459, P<0.001). Trx was an independent predictor for 6-month mortality (Odds ratio, 1.386; 95% confidence interval, 1.015-2.161; P<0.001) and 6-month unfavorable outcome (Odds ratio, 1.297; 95% confidence interval, 1.012-2.002; P<0.001). Based on receiver operating characteristic curve, TRX had similar prognostic value compared with WFNS scores and modified Fisher scores and also significantly improved their prognostic value for 6-month unfavorable outcome, but not for 6-month mortality.

CONCLUSIONS

Elevated plasma Trx levels are correlated with the severity and poor prognosis, substantializing Trx as a potential prognostic predictive biomarker following aSAH.

Serum τ protein as a potential biomarker in the assessment of traumatic brain injury

Traumatic brain injury (TBI) is the leading cause of mortality and disabilities among all trauma cases. Following TBI, damage to axons results in τ protein hyperphosphorylation leading to microtubule instability and τ-mediated neurodegeneration. In addition, τ protein is proteolytically cleaved and is able to access the cerebrospinal fluid (CSF) and serum; thus, this protein may serve as a potential biomarker in the diagnosis of injury severity and outcome prediction. Although a limited number of studies have investigated the CSF τ protein levels after TBI, the data are divergent and conflicting, and investigations into the serum τ protein levels have yet to be conducted. Therefore, the present study aimed to examine the serum τ protein levels in the full spectrum of TBI patients on days 0-14 after TBI, using an enzyme-linked immunosorbent assay. The protein levels were compared to the initial Glasgow Coma Score (GCS) and the Extended Glasgow Outcome Scale (GOS-E), which are used to represent the injury severity and patient outcome, respectively. In total, 56 patients, including 20 patients with mild TBI (GCS, 13-15), 19 patients with moderate TBI (GCS, 9-12) and 17 patients with severe TBI (GCS, 3-8), were included in the current study. The outcome was assessed 1 year after the injury and patients were classified into the good outcome (40 cases; GOS-E, 5-8) and poor outcome groups (16 cases; GOS-E, 1-4). The results indicated that serum τ protein levels increased soon after TBI and reached a peak value at ~2 days after the injury. The serum τ protein levels were significantly higher in the severe TBI group compared with those in the mild and moderate TBI groups (P<0.0001). Univariate analysis indicated that poor outcome was significantly associated with higher serum τ protein levels on day 2 (P<0.0001). A receiver operating characteristic curve demonstrated that a τ protein level of >116.04 pg/ml on day 2 resulted in a 93.75% sensitivity and 92.50% specificity for predicting a poor outcome. Furthermore, a τ protein level of >372.1 pg/ml on day 2 yielded 100% sensitivity and 83.33% specificity for 1 year mortality in the severe TBI group. In conclusion, the present study suggests that serum τ protein may serve as a potential biomarker for evaluating the injury severity and predicting the outcome of TBI patients.

Low serum ficolin-3 levels are associated with severity and poor outcome in traumatic brain injury

Background

Ficolin-mediated activation of the lectin pathway of complement contributes to the complement-independent inflammatory processes of traumatic brain injury. Lower serum ficolin-3 levels have been demonstrated to be highly associated with unfavorable outcome after ischemic stroke. This prospective observatory study was designed to investigate the relationships between serum ficolin-3 levels and injury severity and clinical outcomes after severe traumatic brain injury.

Methods

Serum ficolin-3 levels of 128 patients and 128 healthy controls were measured by sandwich immunoassays. An unfavorable outcome was defined as Glasgow Outcome Scale score of 1–3. Study endpoints included mortality at 1 week and 6 months and unfavorable outcome at 6 months after head trauma. Injury severity was assessed by Glasgow Coma Scale score. Multivariate logistic models were structured to evaluate the relationships between serum ficolin-3 levels and study endpoints and injury severity.

Results

Compared with the healthy controls, serum ficolin-3 levels on admission were statistically decreased in patients with severe traumatic brain injury. Serum ficolin-3 levels were independently correlated with Glasgow Coma Scale scores. Ficolin-3 was also identified as an independent prognostic predictor for 1-week mortality, 6-month mortality, and 6-month unfavorable outcome. Under receiver operating characteristics curves, ficolin-3 has similar prognostic predictive values for all study endpoints compared with Glasgow Coma Scale scores.

Conclusions

It was proposed that lower serum ficolin-3 levels, correlated with injury severity, had the potential to be the useful, complementary tool to predict short- or long-term clinical outcomes after severe traumatic brain injury.