Recombinant human erythropoietin improves functional recovery in patients with severe traumatic brain injury: A randomized, double blind and controlled clinical trial

Emerging therapies for immunomodulation in traumatic brain injury: A systematic review and meta-analysis

Background

Traumatic brain injury (TBI) represents a significant global health burden, often leading to significant morbidity and mortality. Mounting evidence underscores the intricate involvement of dysregulated immune responses in TBI pathophysiology, highlighting the potential for immunomodulatory interventions to mitigate secondary injury cascades and enhance patient outcomes. Despite advancements in treatment modalities, optimizing therapeutic strategies remains a critical challenge in TBI management. To address this gap, this systematic review and meta-analysis aimed to rigorously evaluate the efficacy and safety of emerging immunomodulatory therapies in the context of TBI.

Methods

We searched electronic databases such as PubMed, Scopus, Web of Science and CENTRAL for relevant studies investigating the efficacy of immunomodulatory therapies in TBI that were meticulously selected for inclusion. Two independent reviewers meticulously performed data extraction and quality assessment, adhering to predefined criteria. Both randomized controlled trials (RCTs) and observational studies reporting clinically relevant outcomes, such as mortality rates, the Glasgow coma scale, and adverse events, were meticulously scrutinized. Meta-analysis techniques were employed to assess treatment effects across studies quantitatively and analyzed using the Review Manager software (version 5.2).

Results

Fourteen studies (n = 1 observational and n = 13 RCTs) were included in our study. Meta-analysis showed no significant overall mortality difference, but erythropoietin (EPO) significantly reduced mortality (odds ratio = 0.49; 95% confidence interval: 0.31-0.78, P = 0.002). The adverse event meta-analysis revealed no significant differences.

Conclusion

Immunomodulatory therapies did not significantly affect overall mortality, but EPO demonstrated promising results. Adverse events did not significantly differ from controls. Further research is warranted to refine TBI treatment protocols.

A Modern Approach to the Treatment of Traumatic Brain Injury

Background: Traumatic brain injury manifests itself in various forms, ranging from mild impairment of consciousness to severe coma and death. Traumatic brain injury remains one of the leading causes of morbidity and mortality. Currently, there is no therapy to reverse the effects associated with traumatic brain injury. New neuroprotective treatments for severe traumatic brain injury have not achieved significant clinical success. Methods: A literature review was performed to summarize the recent interdisciplinary findings on management of traumatic brain injury from both clinical and experimental perspective. Results: In the present review, we discuss the concepts of traditional and new approaches to treatment of traumatic brain injury. The recent development of different drug delivery approaches to the central nervous system is also discussed. Conclusions: The management of traumatic brain injury could be aimed either at the pathological mechanisms initiating the secondary brain injury or alleviating the symptoms accompanying the injury. In many cases, however, the treatment should be complex and include a variety of medical interventions and combination therapy.

The Australian Traumatic Brain Injury Initiative: Systematic Review of the Effect of Acute Interventions on Outcome for People With Moderate-Severe Traumatic Brain Injury

The Australian Traumatic Brain Injury Initiative (AUS-TBI) is developing a data resource to enable improved outcome prediction for people with moderate-severe TBI (msTBI) across Australia. Fundamental to this resource is the collaboratively designed data dictionary. This systematic review and consultation aimed to identify acute interventions with potential to modify clinical outcomes for people after msTBI, for inclusion in a data dictionary. Standardized searches were implemented across bibliographic databases from inception through April 2022. English-language reports of randomized controlled trials (RCTs) evaluating any association between any acute intervention and clinical outcome in at least 100 patients with msTBI, were included. A predefined algorithm was used to assign a value to each observed association. Consultation with AUS-TBI clinicians and researchers formed the consensus process for interventions to be included in a single data dictionary. Searches retrieved 14,455 records, of which 124 full-length RCTs were screened, with 35 studies included. These studies evaluated 26 unique acute interventions across 21 unique clinical outcomes. Only 4 interventions were considered to have medium modifying value for any outcome from the review, with an additional 8 interventions agreed upon through the consensus process. The interventions with medium value were tranexamic acid and phenytoin, which had a positive effect on an outcome; and decompressive craniectomy surgery and hypothermia, which negatively affected outcomes. From the systematic review and consensus process, 12 interventions were identified as potential modifiers to be included in the AUS-TBI national data resource.

Beyond brain injury biomarkers: chemoattractants and circulating progenitor cells as biomarkers of endogenous rehabilitation effort in preterm neonates with encephalopathy

Introduction

Preclinical work and studies in adults have shown that endogenous regeneration efforts that involve mobilization of progenitor cells take place after brain injury. However, kinetics of endogenous circulating progenitor cells (CPCs) in preterm neonates is not well described, particularly their possible role regarding brain injury and regeneration. We aimed to assess the kinetics of CPCs in neonates with encephalopathy of prematurity in relation to brain injury biomarkers, chemoattractants and relevant antenatal and postanal clinical factors, in an effort to outline the related pathophysiology.

Materials and methods

47 preterm neonates (of 28-33 weeks GA) were enrolled: 31 newborns with no or minimal brain injury (grade I IVH) and 16 prematures with encephalopathy (grade III or IV IVH, PVL or infarct). Peripheral blood samples obtained on days 1, 3, 9, 18 and 45 after birth were analyzed using flow cytometry, focusing on EPCs (early and late Endothelial Progenitor Cells), HSCs (Hematopoietic Stem Cells) and VSELs (Very Small Embryonic-Like Stem Cells). At the same time-points serum levels of S100B, Neuron-specific Enolase (NSE), Erythropoietin (EPO), Insulin-like growth factor-1 (IGF-1) and SDF-1 were also measured. Neonates were assessed postnatally with brain MRI, and with Bayley III developmental test at 2 years of corrected age.

Results

Preterms with brain injury proved to have significant increase of S100B and NSE, followed by increase of EPO and enhanced mobilization mainly of HSCs, eEPCs and lEPCs. IGF-1 was rather decreased in this group of neonates. IGF-1 and most CPCs were intense decreased in cases of antenatal or postnatal inflammation. S100B and NSE correlated with neuroimaging and language scale in Bayley III test, providing good prognostic ability.

Conclusion

The observed pattern of CPCs' mobilization and its association with neurotrophic factors following preterm brain injury indicate the existence of an endogenous brain regeneration process. Kinetics of different biomarkers and associations with clinical factors contribute to the understanding of the related pathophysiology and might help to early discriminate neonates with adverse outcome. Timely appropriate enhancement of the endogenous regeneration effort, when it is suppressed and insufficient, using neurotrophic factors and exogenous progenitor cells might be a powerful therapeutic strategy in the future to restore brain damage and improve the neurodevelopmental outcome in premature infants with brain injury.

Effects of early adjunctive pharmacotherapy on serum levels of brain injury biomarkers in patients with traumatic brain injury: a systematic review of randomized controlled studies

Objectives: Traumatic brain injury (TBI) is one of the top causes of morbidity and mortality worldwide. The review aimed to discuss and summarize the current evidence on the effectiveness of adjuvant neuroprotective treatments in terms of their effect on brain injury biomarkers in TBI patients. Methods: To identify relevant studies, four scholarly databases, including PubMed, Cochrane, Scopus, and Google Scholar, were systematically searched using predefined search terms. English-language randomized controlled clinical trials reporting changes in brain injury biomarkers, namely, neuron-specific enolase (NSE), glial fibrillary acid protein (GFAP), ubiquitin carboxyl-terminal esterase L1 (UCHL₁) and/or S100 beta (S100 ß), were included. The methodological quality of the included studies was assessed using the Cochrane risk-of-bias tool. Results: A total of eleven studies with eight different therapeutic options were investigated; of them, tetracyclines, metformin, and memantine were discovered to be promising choices that could improve neurological outcomes in TBI patients. The most utilized serum biomarkers were NSE and S100 ß followed by GFAP, while none of the included studies quantified UCHL₁. The heterogeneity in injury severity categories and measurement timing may affect the overall evaluation of the clinical efficacy of potential therapies. Therefore, unified measurement protocols are highly warranted to inform clinical decisions. Conclusion: Few therapeutic options showed promising results as an adjuvant to standard care in patients with TBI. Several considerations for future work must be directed towards standardizing monitoring biomarkers. Investigating the pharmacotherapy effectiveness using a multimodal biomarker panel is needed. Finally, employing stratified randomization in future clinical trials concerning potential confounders, including age, trauma severity levels, and type, is crucial to inform clinical decisions. Clinical Trial Registration: [https://www.crd.york.ac.uk/prospero/dis], identifier [CRD42022316327].

Pharmacological components with neuroprotective effects in the management of traumatic brain injury: evidence from network meta-analysis

BACKGROUND

Neuroprotective drugs have been used to prevent secondary brain injury in patients with traumatic brain injury; however, the optimal medication remains questionable. We performed a Bayesian network meta-analysis to evaluate the safety and efficacy of different medications with known neuroprotective properties in this group of patients.

METHODS

Several databases were searched to identify any eligible trials comparing pharmacological components with confirmed neuroprotective mechanisms. Bayesian network meta-analysis was performed to combine direct and indirect evidence. The surface under the cumulative ranking curve was obtained to determine the ranking probability of the treatment agents for each outcome. The primary outcome was all-cause mortality.

RESULTS

A total of 23 trials comprising 4,325 participants were identified. The pooled relative risk (RR) showed administration of erythropoietin (RR: 0.68; 95% CrI: 0.50-0.93) and propranolol (RR: 0.43; 95% CrI: 0.20-0.85) decreased all-cause mortality compared with placebo. We also found erythropoietin (RR: 1.55; 95% CrI: 1.03-2.35), propranolol (RR: 1.52; 95% CrI: 1.05-2.20), and progesterone (RR: 1.47; 95% CrI: 1.03-2.10) showed better efficacy in functional recovery.

CONCLUSION

Overall, erythropoietin and propranolol were associated with reduced mortality in adults with traumatic brain injury. These treatment agents were also associated with improved functional outcomes.

Modulation of Burn Hypermetabolism in Preclinical Models

Severe burns elicit a state of physiological stress and increased metabolism to help the body compensate for the changes associated with the traumatic injury. However, this hypermetabolic state is associated with increased insulin resistance, cardiovascular dysfunction, skeletal muscle catabolism, impaired wound healing, and delayed recovery. Several interventions were attempted to modulate burn hypermetabolism, including nutritional support, early excision and grafting, and growth hormone application. However, burn hypermetabolism still imposes significant morbidity and mortality in burn patients. Due to the limitations of in vitro models, animal models are indispensable in burn research. Animal models provide researchers with invaluable tools to test the safety and efficacy of novel treatments or advance our knowledge of previously utilized agents. Several animal studies evaluated novel therapies to modulate burn hypermetabolism in the last few years, including recombinant human growth hormone, erythropoietin, acipimox, apelin, anti-interleukin-6 monoclonal antibody, and ghrelin therapies. Results from these studies are promising and may be effectively translated into human studies. In addition, other studies revisited drugs previously used in clinical practice, such as insulin and metformin, to further investigate their underlying mechanisms as modulators of burn hypermetabolism. This review aims to update burn experts with the novel therapies under investigation in burn hypermetabolism with a focus on applicability and translation. Furthermore, we aim to guide researchers in selecting the correct animal model for their experiments by providing a summary of the methodology and the rationale of the latest studies.

Comparative safety of multiple doses of erythropoietin for the treatment of traumatic brain injury: A systematic review and network meta-analysis

Introduction

Over the past few decades, advances in traumatic brain injury (TBI) pathology research have dynamically enriched our knowledge. Therefore, we aimed to systematically elucidate the safety and efficacy of erythropoietin (EPO) dosing regimens in patients with TBI.

Methods

Data search included PubMed, the Cochrane Library, Embase, Web of Science, and ClinicalTrials.gov for related research published before July 2022. The network meta-analysis was conducted using ADDIS 1.16.8, and the CINeMA tool was used to assess the quality level of evidence.

Results

A total of six RCTs involving 981 patients were included in the network meta-analysis. EPO did not significantly reduce mortality in patients with TBI, but its risk of death decreased with increasing dosage (odds ratio (OR) of 12,000u vs. placebo = 0.98, 95% CI: 0.03-40.34; OR of group 30,000u vs. placebo = 0.56, 95% CI: 0.06-5.88; OR of 40,000u vs. placebo = 0.35, 95% CI: 0.01-9.43; OR of 70,000u vs. placebo = 0.29, 95% CI: 0.01-9.26; OR of group 80,000u vs. placebo = 0.22, 95% CI: 0.00-7.45). A total of three studies involving 739 patients showed that EPO did not increase the incidence of deep vein thrombosis in patients with TBI. However, the risk tended to rise as the dosage increased. Another two studies demonstrated that EPO did not increase the incidence of pulmonary embolism. The quality of evidence for all outcomes was low to moderate.

Conclusion

Although the efficacy of EPO was not statistically demonstrated, we found a trend toward an association between EPO dosage and reduced mortality and increased embolic events in patients with TBI. More high-quality original studies should be conducted to obtain strong evidence on the optimal dosage of EPO.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=272500. The study protocol was registered with PROSPERO (CRD42021272500).

Recombinant human erythropoietin induces neuroprotection, activates MAPK/CREB pathway, and rescues fear memory after traumatic brain injury with delayed hypoxemia in mice

Therapeutic interventions targeting secondary insults, such as delayed hypoxemia, provide a unique opportunity for treatment in severe traumatic brain injury (TBI). Erythropoietin (EPO) is a hypoxia-responsive cytokine with important roles in neurodevelopment, neuroprotection and neuromodulation. We hypothesized that recombinant human erythropoietin (rhEPO) administration would mitigate injury in a combined injury model of TBI and delayed hypoxemia. Utilizing a clinically relevant murine model of TBI and delayed hypoxemia, we characterized how ongoing rhEPO administration influenced neurogenesis, neuroprotection, synaptic density and, behavioral outcomes early after TBI, and the impact on long-lasting outcomes 6 months after injury. We employed novel object recognition (NOR) and fear conditioning to assess long-term memory. At 1-month post-injury, we observed a significant increase in cued-fear memory response in the rhEPO-injured mice compared with vehicle-injured mice. This was associated with neuroprotection and neurogenesis in the hippocampus and mitogen-activated protein kinase (MAPK)/cAMP response element-binding protein (CREB) signaling activation and increased of excitatory synaptic density in the amygdala. Early rhEPO treatment after injury reduced neurodegeneration and increased excitatory synaptic density in the hippocampus and amygdala at 6 months post-injury. However at 6 months post-injury (4 months after discontinuation of rhEPO), we did not observe changes in behavioral assessments nor MAPK/CREB pathway activation. In summary, these data demonstrate that ongoing rhEPO treatment initiated at a clinically feasible time point improves neurological, cognitive, and histological outcomes after TBI in the setting of secondary hypoxemic insults.

Effect of drug therapy on nerve repair of moderate-severe traumatic brain injury: A network meta-analysis

Objective: This network meta-analysis aimed to explore the effect of different drugs on mortality and neurological improvement in patients with traumatic brain injury (TBI), and to clarify which drug might be used as a more promising intervention for treating such patients by ranking.

Methods: We conducted a comprehensive search from PubMed, Medline, Embase, and Cochrane Library databases from the establishment of the database to 31 January 2022. Data were extracted from the included studies, and the quality was assessed using the Cochrane risk-of-bias tool. The primary outcome measure was mortality in patients with TBI. The secondary outcome measures were the proportion of favorable outcomes and the occurrence of drug treatment–related side effects in patients with TBI in each drug treatment group. Statistical analyses were performed using Stata v16.0 and RevMan v5.3.0.

Results: We included 30 randomized controlled trials that included 13 interventions (TXA, EPO, progesterone, progesterone + vitamin D, atorvastatin, beta-blocker therapy, Bradycor, Enoxaparin, Tracoprodi, dexanabinol, selenium, simvastatin, and placebo). The analysis revealed that these drugs significantly reduced mortality in patients with TBI and increased the proportion of patients with favorable outcomes after TBI compared with placebo. In terms of mortality after drug treatment, the order from the lowest to the highest was progesterone + vitamin D, beta-blocker therapy, EPO, simvastatin, Enoxaparin, Bradycor, Tracoprodi, selenium, atorvastatin, TXA, progesterone, dexanabinol, and placebo. In terms of the proportion of patients with favorable outcomes after drug treatment, the order from the highest to the lowest was as follows: Enoxaparin, progesterone + vitamin D, atorvastatin, simvastatin, Bradycor, EPO, beta-blocker therapy, progesterone, Tracoprodi, TXA, selenium, dexanabinol, and placebo. In addition, based on the classification of Glasgow Outcome Scale (GOS) scores after each drug treatment, this study also analyzed the three aspects of good recovery, moderate disability, and severe disability. It involved 10 interventions and revealed that compared with placebo treatment, a higher proportion of patients had a good recovery and moderate disability after treatment with progesterone + vitamin D, Bradycor, EPO, and progesterone. Meanwhile, the proportion of patients with a severe disability after treatment with progesterone + vitamin D and Bradycor was also low.

Conclusion: The analysis of this study revealed that in patients with TBI, TXA, EPO, progesterone, progesterone + vitamin D, atorvastatin, beta-blocker therapy, Bradycor, Enoxaparin, Tracoprodi, dexanabinol, selenium, and simvastatin all reduced mortality and increased the proportion of patients with favorable outcomes in such patients compared with placebo. Among these, the progesterone + vitamin D had not only a higher proportion of patients with good recovery and moderate disability but also a lower proportion of patients with severe disability and mortality. However, whether this intervention can be used for clinical promotion still needs further exploration.

Does erythropoietin affect the outcome and complication rates of patient with traumatic brain injury? A pooled-analysis

OBJECTIVE

The aim of this meta-analysis was to review the scientific literature published until April 18, 2021, to summarize existing knowledge on the efficacy and safety of erythropoietin (EPO) for traumatic brain injury (TBI).

METHODS

This systematic review followed PRISMA guidelines. Randomized controlled trials (RCTs) reporting on the efficacy and safety of EPO in the treatment of TBI were systematically searched in relevant electronic databases according to a pre-designed search strategy. The primary outcomes are the mortality; and secondary outcomes are the good functional outcome (GFO) and adverse events (AEs).

RESULTS

A total of 10 RCTs involving 2,402 participants fulfilled the inclusion criteria. The results showed that there is a significant difference in terms of the mortality (RR = 0.67, 95% CI = 0.54-0.84, P = 0.0003) and seizure rate (RR = 0.52, 95% CI = 0.29-0.96, P = 0.04) between the EPO groups compared to those in the control groups. However, compared with the control groups, the GFO in the EPO groups was not statistically significant (RR = 1.18, 95% CI = 0.93-1.48, P = 0.17).

CONCLUSIONS

Findings of the present meta-analysis suggest that the use of EPO could reduce mortality rate in patients with TBI, without increasing the incidence of AEs. EPO has potential research and application value in the treatment of TBI.

Effect of erythropoietin administration on the expression of brain-derived neurotrophic factor, stromal cell-derived Factor-1, and neuron-specific enolase in traumatic brain injury: A literature review

Traumatic brain injury (TBI) is a major cause of death and lifelong disability around the world that predominantly affects young and middle-aged people. Erythropoietin (EPO) is a promising therapeutic agent for a variety of neurological injuries including TBI due to its neuroprotective effects. Here we review the impact of exogenous erythropoietin administration on the expression of brain-derived neurotrophic factor (BDNF), stromal cell-derived factor-1 (SDF-1), and neuron-specific enolase (NSE) levels in cerebrospinal fluid after TBI as biomarkers for neuron regeneration and survival to predict TBI outcome.

Erythropoietin and derivatives: Potential beneficial effects on the brain

Erythropoietin (Epo), the main erythropoiesis-stimulating factor widely prescribed to overcome anemia, is also known nowadays for its cytoprotective action on non-hematopoietic tissues. In this context, Epo showed not only its ability to cross the blood-brain barrier, but also its expression in the brain of mammals. In clinical trials, recombinant Epo treatment has been shown to stimulate neurogenesis; improve cognition; and activate antiapoptotic, antioxidant, and anti-inflammatory signaling pathways. These mechanisms, proposed to characterize a neuroprotective property, opened new perspectives on the Epo pharmacological potencies. However, many questions arise about a possible physiological role of Epo in the central nervous system (CNS) and the factors or environmental conditions that induce its expression. Although Epo may be considered a strong candidate to be used against neuronal damage, long-term treatments, particularly when high Epo doses are needed, may induce thromboembolic complications associated with increases in hematocrit and blood viscosity. To avoid these adverse effects, different Epo analogs without erythropoietic activity but maintaining neuroprotection ability are currently being investigated. Carbamylated erythropoietin, as well as alternative molecules like Epo fusion proteins and partial peptides of Epo, seems to match this profile. This review will focus on the discussion of experimental evidence reported in recent years linking erythropoietin and CNS function through investigations aimed at finding benefits in the treatment of neurodegenerative diseases. In addition, it will review the proposed mechanisms for novel derivatives which may clarify and, eventually, improve the neuroprotective action of Epo.

Role of innate inflammation in traumatic brain injury

Traumatic brain injury is one of the leading causes of morbidity and mortality throughout the world. Its increasing incidence, in addition to its fundamental role in the development of neurodegenerative disease, proves especially concerning. Despite extensive preclinical and clinical studies, researchers have yet to identify a safe and effective neuroprotective strategy. Following brain trauma, secondary injury from molecular, metabolic, and cellular changes causes progressive cerebral tissue damage. Chronic neuroinflammation following traumatic brain injuries is a key player in the development of secondary injury. Targeting this phenomenon for development of effective neuroprotective therapies holds promise. This strategy warrants a concrete understanding of complex neuroinflammatory mechanisms. In this review, we discuss pathophysiological mechanisms such as the innate immune response, glial activation, blood-brain barrier disruption, activation of immune mediators, as well as biological markers of traumatic brain injury. We then review existing and emerging pharmacological therapies that target neuroinflammation to improve functional outcome.

The Monocyte-to-Lymphocyte Ratio at Hospital Admission Is a Novel Predictor for Acute Traumatic Intraparenchymal Hemorrhage Expansion after Cerebral Contusion

PURPOSE

To explore the potential of monocyte-to-lymphocyte ratio (MLR) at hospital admission for predicting acute traumatic intraparenchymal hematoma (tICH) expansion in patients with cerebral contusion. Patients and Methods. This multicenter, observational study included patients with available at-hospital admission (baseline) and follow-up computed tomography for volumetric analysis (retrospective development cohort: 1146 patients; prospective validation cohort: 207 patients). Semiautomated software assessed tICH expansion (defined as ≥33% or 5 mL absolute growth). MLR was acquired from routine blood tests upon admission. We constructed two predictive models: basic combined model of clinical and imaging variables and MLR combined model of both MLR and other variables in the basic model. Receiver operating characteristic (ROC) analysis and decision curve analysis (DCA) were used to estimate the performance of MLR for predicting acute tICH expansion.

RESULTS

MLR was significantly larger in patients with acute tICH expansion compared to those without acute tICH expansion (mean [SD], 1.08 [1.05] vs. 0.59 [0.37], P < 0.001). A nonlinear positive relationship between MLR and the incidence of acute tICH expansion was observed. Multivariate logistic regression indicated MLR as an independent risk factor for acute tICH expansion (odds ratio (OR), 5.88; 95% confidence interval (CI), 4.02-8.61). The power of the multivariate model for predicting acute tICH expansion was substantially improved with the inclusion of MLR (AUC 0.86 vs. AUC 0.74, P < 0.001), as was also observed in an external validation cohort (AUC 0.83 vs. AUC 0.71, P < 0.001). The net benefit of MLR model was higher between threshold probabilities of 20-100% in DCA. For clinical application, a nomogram derived from the multivariate model with MLR was introduced. In addition, MLR was positively associated with 6-month unfavorable outcome.

CONCLUSION

MLR is a novel predictor for traumatic parenchymatous hematoma expansion. A nomogram derived from the MLR model may provide an easy-to-use tool for predicting acute tICH expansion and promoting the individualized treatment of patients with hemorrhagic cerebral contusion. MLR is associated with long-term outcome after cerebral contusion.

Potential Efficacy of Erythropoietin on Reducing the Risk of Mortality in Patients with Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Objective

The objective of this study is to assess the effectiveness of erythropoietin (EPO) on mortality, neurological outcomes, and adverse event in the treatment of traumatic brain injury (TBI).

Methods

We searched databases including PubMed, OVID, and the Cochrane Library from inception until October 18, 2019 for randomized controlled trials (RCTs) to compare EPO treatment group and placebo in patients with TBI. Two authors independently processed the data and evaluated the quality of inclusion studies. Statistical analysis was performed with heterogeneity test with I ² and chi-square tests. We summarized the mortality, prognosis of neurological function, and deep vein thrombosis (DVT) outcomes and presented as risk ratio (RR) or risk difference (RD) with a 95% CI.

Results

Seven RCTs accounting for 1180 patients were included after meeting the inclusion criteria. Compared with placebo, the overall mortality of EPO-treated patients was significantly reduced (RR 0.68 [95% CI 0.50-0.93]; p = 0.02). EPO therapy did not improve neurological prognosis (RR 1.21 [95% CI 0.93-1.15]; p = 0.16) or increase the occurrence of DVT (RR 0.83 [95% CI 0.61-1.13]; p = 0.242), which showed no significant difference.

Conclusions

The results showed that the administration of EPO may reduce the risk of mortality without enhancing the occurrence of DVT in TBI patients. However, the effect of EPO on neurological outcome remains indistinct. Through subgroup analysis, we demonstrated that the dose of EPO may be a potential factor affecting the heterogeneity in neurological function and that the follow-up duration may influence the stability of the result.

Efficacy and safety of erythropoietin for traumatic brain injury

BACKGROUND

Recent studies regarding the effects of erythropoietin (EPO) for treating traumatic brain injury (TBI) have been inconsistent. This study conducts a meta-analysis of randomized controlled trials (RCTs) to assess the safety and efficacy of EPO for TBI patients at various follow-up time points.

METHODS

A literature search was performed using PubMed, Web of Science, MEDLINE, Embase, Google Scholar and the Cochrane Library for RCTs studying EPO in TBI patients published through March 2019. Non-English manuscripts and non-human studies were excluded. The assessed outcomes include mortality, neurological recovery and associated adverse effects. Dichotomous variables are presented as risk ratios (RR) with a 95% confidence interval (CI).

RESULTS

A total of seven RCTs involving 1197 TBI patients (611 treated with EPO, 586 treated with placebo) were included in this study. Compared to the placebo arm, treatment with EPO did not improve acute hospital mortality or short-term mortality. However, there was a significant improvement in mid-term (6 months) follow-up survival rates. EPO administration was not associated with neurological function improvement. Regarding adverse effects, EPO treatment did not increase the incidence of thromboembolic events or other associated adverse events.

CONCLUSIONS

This meta-analysis indicates a slight mortality benefit for TBI patients treated with EPO at mid-term follow-up. EPO does not improve in-hospital mortality, nor does it increase adverse events including thrombotic, cardiovascular and other associated complications. Our analysis did not demonstrate a significant beneficial effect of EPO intervention on the recovery of neurological function. Future RCTs are required to further characterize the use of EPO in TBI.

Drugs with anti-inflammatory effects to improve outcome of traumatic brain injury: a meta-analysis

Outcome after traumatic brain injury (TBI) varies largely and degree of immune activation is an important determinant factor. This meta-analysis evaluates the efficacy of drugs with anti-inflammatory properties in improving neurological and functional outcome. The systematic search following PRISMA guidelines resulted in 15 randomized placebo-controlled trials (3734 patients), evaluating progesterone, erythropoietin and cyclosporine. The meta-analysis (15 studies) showed that TBI patients receiving a drug with anti-inflammatory effects had a higher chance of a favorable outcome compared to those receiving placebo (RR = 1.15; 95% CI 1.01–1.32, p = 0.041). However, publication bias was indicated together with heterogeneity (I² = 76.59%). Stratified analysis showed that positive effects were mainly observed in patients receiving this treatment within 8 h after injury. Subanalyses by drug type showed efficacy for progesterone (8 studies, RR 1.22; 95% CI 1.01–1.47, p = 0.040), again heterogeneity was high (I² = 62.92%) and publication bias could not be ruled out. The positive effect of progesterone covaried with younger age and was mainly observed when administered intramuscularly and not intravenously. Erythropoietin (4 studies, RR 1.20; p = 0.110; I² = 76.59%) and cyclosporine (3 studies, RR 0.75; p = 0.189, I² = 0%) did not show favorable significant effects. While negative findings for erythropoietin may reflect insufficient power, cyclosporine did not show better outcome at all. Current results do not allow firm conclusions on the efficacy of drugs with anti-inflammatory properties in TBI patients. Included trials showed heterogeneity in methodological and sample parameters. At present, only progesterone showed positive results and early administration via intramuscular administration may be most effective, especially in young people. The anti-inflammatory component of progesterone is relatively weak and other mechanisms than mitigating overall immune response may be more important.

Current strategies for therapeutic drug delivery after traumatic CNS injury

Therapeutic strategies for traumatic injuries in the central nervous system (CNS) are largely limited to the efficiency of drug delivery. Despite the disrupted blood-CNS barrier during the early phase after injury, the drug administration faces a variety of obstacles derived from homeostatic imbalance at the injury site. In the late phase after CNS injury, the restoration of the blood-CNS barrier integrity varies depending on the injury severity resulting in inconsistent delivery of therapeutics. This review intends to characterize those different challenges of the therapeutic delivery in acute and chronic phases after injury and discuss recent advances in various approaches to explore novel strategies for the treatment of traumatic CNS injury.

Meta-Analysis with Trial Sequential Analysis on the Efficacy and Safety of Erythropoietin in Traumatic Brain Injury: A New Paradigm

OBJECTIVE

Erythropoietin (EPO) has been shown to be beneficial in traumatic brain injury (TBI). We have attempted to quantitatively synthesize the findings of current randomized controlled trials (RCTs) in this meta-analysis and analyzed the need for further trials using trial sequential analysis (TSA).

METHODS

A systematic search was performed in PubMed, the Cochrane Library databases, and Google Scholar for RCTs until December 2019 evaluating the role of EPO in patients with TBI. Seven RCTs were finally included in the quantitative analysis. TSA was done to evaluate the need for further studies.

RESULTS

The pooled estimate demonstrated that EPO significantly reduced mortality at 6 months (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.43-0.97; P = 0.04) but not in hospital mortality (OR, 0.84; 95% CI, 0.31-2.32; P = 0.74). There was no significant difference in the rate of favorable outcomes with EPO (OR, 1.58; 95% CI, 0.84-2.99; P = 0.16). The rate of deep vein thrombosis (RD, -0.02; 95% CI, -0.06 to 0.02; P =0.41) was also not found to be significantly different in the 2 groups. TSA showed that the accrued information is insufficient to make any definitive conclusions.

CONCLUSIONS

EPO seems to be beneficial in terms of reducing 6-month mortality, however, its effect on in-hospital mortality, neurologic outcomes, and risk of deep vein thrombosis fails to reach statistical significance. TSA suggests a need for large trials to evaluate the role of EPO in patients with TBI in a more systematic way.

Erythropoietin Alleviates Burn-induced Muscle Wasting

Background: Burn injury induces long-term skeletal muscle pathology. We hypothesized EPO could attenuate burn-induced muscle fiber atrophy. Methods: Rats were allocated into four groups: a sham burn group, an untreated burn group subjected to third degree hind paw burn, and two burn groups treated with weekly or daily EPO for four weeks. Gastrocnemius muscle was analyzed at four weeks post-burn. Results: EPO attenuated the reduction of mean myofiber cross-sectional area post-burn and the level of the protective effect was no significant difference between two EPO-treated groups (p=0.784). Furthermore, EPO decreased the expression of atrophy-related ubiquitin ligase, atrogin-1, which was up-regulated in response to burn. Compared to untreated burn rats, those receiving weekly or daily EPO groups had less cell apoptosis by TUNEL assay. EPO decreased the expression of cleaved caspase 3 (key factor in the caspase-dependent pathway) and apoptosis-inducing factor (implicated in the caspase-independent pathway) after burn. Furthermore, EPO alleviated connective tissue overproduction following burn via transforming growth factor beta 1-Smad2/3 pathway. Daily EPO group caused significant erythrocytosis compared with untreated burn group but not weekly EPO group. Conclusion: EPO therapy attenuated skeletal muscle apoptosis and fibrosis at four weeks post-burn. Weekly EPO may be a safe and effective option in muscle wasting post-burn.

Recent advances in traumatic brain injury

Traumatic brain injury (TBI) is the most common cause of death and disability in those aged under 40 years in the UK. Higher rates of morbidity and mortality are seen in low-income and middle-income countries making it a global health challenge. There has been a secular trend towards reduced incidence of severe TBI in the first world, driven by public health interventions such as seatbelt legislation, helmet use, and workplace health and safety regulations. This has paralleled improved outcomes following TBI delivered in a large part by the widespread establishment of specialised neurointensive care. This update will focus on three key areas of advances in TBI management and research in moderate and severe TBI: refining neurointensive care protocolized therapies, the recent evidence base for decompressive craniectomy and novel pharmacological therapies. In each section, we review the developing evidence base as well as exploring future trajectories of TBI research.

Erythropoietin Does Not Alter Serum Profiles of Neuronal and Axonal Biomarkers After Traumatic Brain Injury: Findings From the Australian EPO-TBI Clinical Trial

OBJECTIVE

To determine profiles of serum ubiquitin carboxy-terminal hydrolase L1 and phosphorylated neurofilament heavy-chain, examine whether erythropoietin administration reduce their concentrations, and whether biomarkers discriminate between erythropoietin and placebo treatment groups.

DESIGN

Single-center, prospective observational study.

SETTING

A sub-study of the erythropoietin-traumatic brain injury clinical trial, conducted at the Alfred Hospital, Melbourne, Australia.

PATIENTS

Forty-four patients with moderate-to-severe traumatic brain injury.

INTERVENTIONS

Epoetin alfa 40,000 IU or 1 mL sodium chloride 0.9 as subcutaneous injection within 24 hours of traumatic brain injury.

MEASUREMENTS AND MAIN RESULTS

Ubiquitin carboxy-terminal hydrolase L1, phosphorylated neurofilament heavy-chain, and erythropoietin concentrations were measured in serum by enzyme-linked immunosorbent assay from D0 (within 24 hr of injury, prior to erythropoietin/vehicle administration) to D5. Biomarker concentrations were compared between injury severities, diffuse versus focal traumatic brain injury and erythropoietin or placebo treatment groups. Ubiquitin carboxy-terminal hydrolase L1 peaked at 146.0 ng/mL on D0, significantly decreased to 84.30 ng/mL on D1, and declined thereafter. Phosphorylated neurofilament heavy-chain levels were lowest at D0 and peaked on D5 at 157.9 ng/mL. D0 ubiquitin carboxy-terminal hydrolase L1 concentrations were higher in diffuse traumatic brain injury. Peak phosphorylated neurofilament heavy-chain levels on D3 and D4 correlated with Glasgow Outcome Score-Extended, predicting poor outcome. Erythropoietin did not reduce concentrations of ubiquitin carboxy-terminal hydrolase L1 or phosphorylated neurofilament heavy-chain.

CONCLUSIONS

Serum ubiquitin carboxy-terminal hydrolase L1 and phosphorylated neurofilament heavy-chain increase after traumatic brain injury reflecting early neuronal and progressive axonal injury. Consistent with lack of improved outcome in traumatic brain injury patients treated with erythropoietin, biomarker concentrations and profiles were not affected by erythropoietin. Pharmacokinetics of erythropoietin suggest that the dose given was possibly too low to exert neuroprotection.

Efficacy and safety of erythropoietin in patients with traumatic brain injury: A systematic review and meta-analysis

OBJECTIVE

The purpose of this study was to evaluate the effects of erythropoietin (EPO) on mortality and neurological outcomes in patients with traumatic brain injury (TBI).

MATERIALS AND METHODS

Electronic databases of studies published up to January 5, 2017 were searched to retrieve relevant investigations comparing the outcomes of EPO-treated patients and untreated patients following TBI. We calculated the relative risk (RR) of mortality, neurologic outcomes, and deep vein thrombosis (DVT) with corresponding 95% confidence interval (CI) using meta-analysis.

RESULTS

Six randomized controlled clinical trials met the eligibility criteria. In total, 1041 patients were included among the studies. EPO was found to significantly reduce the occurrence of mortality (RR 0.68 [95% CI 0.50-0.95]; P = 0.02), but did not significantly reduce poor functional outcome (RR 1.22 [95% CI 0.82-1.81]; P = 0.33). There were no significant differences in the occurrence of complications, such as DVT, between the treatment groups (RR -0.02 [95% CI -0.06-0.02]; P = 0.81).

CONCLUSIONS

Results of the present meta-analysis suggest that the use of EPO may prevent death following TBI without causing adverse events, such as deep vein thrombosis. However, the role of EPO in improving neurological outcome(s) remains unclear. Further well-designed, randomized controlled trials using modified protocols and involving specific patient populations are required to clarify this issue, and to verify the findings.

The role of autoimmunity in pituitary dysfunction due to traumatic brain injury

PURPOSE

Traumatic brain injury (TBI) is one of the most common causes of mortality and long-term disability and it is associated with an increased prevalence of neuroendocrine dysfunctions. Post-traumatic hypopituitarism (PTHP) results in major physical, psychological and social consequences leading to impaired quality of life. PTHP can occur at any time after traumatic event, evolving through various ways and degrees of deficit, requiring appropriate screening for early detection and treatment. Although the PTHP pathophysiology remains to be elucitated, on the basis of proposed hypotheses it seems to be the result of combined pathological processes, with a possible role played by hypothalamic-pituitary autoimmunity (HPA). This review is aimed at focusing on this possible role in the development of PTHP and its potential clinical consequences, on the basis of the data so far appeared in the literature and of some results of personal studies on this issue.

METHODS

Scrutinizing the data so far appeared in literature on this topic, we have found only few studies evaluating the autoimmune pattern in affected patients, searching in particular for antipituitary and antihypothalamus autoantibodies (APA and AHA, respectively) by simple indirect immunofluorescence.

RESULTS

The presence of APA and/or AHA at high titers was associated with an increased risk of onset/persistence of PTHP.

CONCLUSIONS

HPA seems to contribute to TBI-induced pituitary damage and related PTHP. However, further prospective studies in a larger cohort of patients are needed to define etiopathogenic and diagnostic role of APA/AHA in development of post-traumatic hypothalamic/pituitary dysfunctions after a TBI.

Time to reconsider extended erythropoietin treatment for infantile traumatic brain injury?

Pediatric traumatic brain injury (TBI) remains a leading cause of childhood morbidity and mortality worldwide. Most efforts to reduce the chronic impact of pediatric TBI involve prevention and minimization of secondary injury. Currently, no treatments are used in routine clinical care during the acute and subacute phases to actively repair injury to the developing brain. The endogenous pluripotent cytokine erythropoietin (EPO) holds promise as an emerging neuroreparative agent in perinatal brain injury (PBI). EPO signaling in the central nervous system (CNS) is essential for multiple stages of neurodevelopment, including the genesis, survival and differentiation of multiple lineages of neural cells. Postnatally, EPO signaling decreases markedly as the CNS matures. Importantly, high-dose, extended EPO regimens have shown efficacy in preclinical controlled cortical impact (CCI) models of infant TBI at two different, early ages by independent research groups. Specifically, extended high-dose EPO treatment after infantile CCI prevents long-term cognitive deficits in adult rats. Because of the striking differences in the molecular and cellular responses to both injury and recovery in the developing and mature CNS, and the excellent safety profile of EPO in infants and children, extended courses of EPO are currently in Phase III trials for neonates with PBI. Extended, high-dose EPO may also warrant testing for infants and young children with TBI.

The complexity of neuroinflammation consequent to traumatic brain injury: from research evidence to potential treatments

This review recounts the definitions and research evidence supporting the multifaceted roles of neuroinflammation in the injured brain following trauma. We summarise the literature fluctuating from the protective and detrimental properties that cytokines, leukocytes and glial cells play in the acute and chronic stages of TBI, including the intrinsic factors that influence cytokine responses and microglial functions relative to genetics, sex, and age. We elaborate on the pros and cons that cytokines, chemokines, and microglia play in brain repair, specifically neurogenesis, and how such conflicting roles may be harnessed therapeutically to sustain the survival of new neurons. With a brief review of the clinical and experimental findings demonstrating early and chronic inflammation impacts on outcomes, we focus on the clinical conditions that may be amplified by neuroinflammation, ranging from acute seizures to chronic epilepsy, neuroendocrine dysfunction, dementia, depression, post-traumatic stress disorder and chronic traumatic encephalopathy. Finally, we provide an overview of the therapeutic agents that have been tested to reduce inflammation-driven secondary pathological cascades and speculate the future promise of alternative drugs.

Erythropoietin in Critical Illness and Trauma

Erythropoietin (EPO) is a 34kD pleiotropic cytokine that was first identified as being essential for red blood cell (RBC) production. It is now recognized however that EPO is produced by many tissues. It plays a key role in the modulation of the response to injury, inflammation, and tissue hypoxia via the inhibition of apoptosis. Large clinical trials in the critically ill failed to demonstrate a role for EPO as an RBC transfusion sparing agent; however, improved clinical outcomes, attributable to EPO role in tissue protection are observed in critically ill trauma patients. Further research to confirm or refute these observations is required.

Neuroinflammation and blood-brain barrier disruption following traumatic brain injury: Pathophysiology and potential therapeutic targets

Traumatic Brain Injury (TBI) is the most frequent cause of death and disability in young adults and children in the developed world, occurring in over 1.7 million persons and resulting in 50,000 deaths in the United States alone. The Centers for Disease Control and Prevention estimate that between 3.2 and 5.3 million persons in the United States live with a TBI-related disability, including several neurocognitive disorders and functional limitations. Following the primary mechanical injury in TBI, literature suggests the presence of a delayed secondary injury involving a variety of neuroinflammatory changes. In the hours to days following a TBI, several signaling molecules and metabolic derangements result in disruption of the blood-brain barrier, leading to an extravasation of immune cells and cerebral edema. The primary, sudden injury in TBI occurs as a direct result of impact and therefore cannot be treated, but the timeline and pathophysiology of the delayed, secondary injury allows for a window of possible therapeutic options. The goal of this review is to discuss the pathophysiology of the primary and delayed injury in TBI as well as present several preclinical studies that identify molecular targets in the potential treatment of TBI. Additionally, certain recent clinical trials are briefly discussed to demonstrate the current state of TBI investigation.

EPO improved neurologic outcome in rat pups late after traumatic brain injury

In adult rats, erythropoietin improved outcomes early and late after traumatic brain injury, associated with increased levels of Brain Derived Neurotrophic Factor. Using our model of pediatric traumatic brain injury, controlled cortical impact in 17-day old rats, we previously showed that erythropoietin increased hippocampal neuronal fraction in the first two days after injury. Erythropoietin also decreased activation of caspase3, an apoptotic enzyme modulated by Brain Derived Neurotrophic Factor, and improved Novel Object Recognition testing 14 days after injury. Data on long-term effects of erythropoietin on Brain Derived Neurotrophic Factor expression, histology and cognitive function after developmental traumatic brain injury are lacking. We hypothesized that erythropoietin would increase Brain Derived Neurotrophic Factor and improve long-term object recognition in rat pups after controlled cortical impact, associated with increased neuronal fraction in the hippocampus.

METHODS

Rats pups received erythropoietin or vehicle at 1, 24, and 48 h and 7 days after injury or sham surgery followed by histology at 35 days, Novel Object Recognition testing at adulthood, and Brain Derived Neurotrophic Factor measurements early and late after injury.

RESULTS

Erythropoietin improved Novel Object Recognition performance and preserved hippocampal volume, but not neuronal fraction, late after injury.

CONCLUSIONS

Improved object recognition in erythropoietin treated rats was associated with preserved hippocampal volume late after traumatic brain injury. Erythropoietin is approved to treat various pediatric conditions. Coupled with exciting experimental and clinical studies suggesting it is beneficial after neonatal hypoxic ischemic brain injury, our preliminary findings support further study of erythropoietin use after developmental traumatic brain injury.

Erythropoietin attenuates motor neuron programmed cell death in a burn animal model

Burn-induced neuromuscular dysfunction may contribute to long-term morbidity; therefore, it is imperative to develop novel treatments. The present study investigated whether erythropoietin (EPO) administration attenuates burn-induced motor neuron apoptosis and neuroinflammatory response. To validate our hypothesis, a third-degree hind paw burn rat model was developed by bringing the paw into contact with a metal surface at 75°C for 10 s. A total of 24 male Sprague–Dawley rats were randomly assigned to four groups: Group A, sham-control; Group B, burn-induced; Group C, burn + single EPO dose (5000 IU/kg i.p. at D0); and Group D, burn + daily EPO dosage (3000 IU/kg/day i.p. at D0–D6). Two treatment regimens were used to evaluate single versus multiple doses treatment effects. Before sacrifice, blood samples were collected for hematological parameter examination. The histological analyses of microglia activation, iNOS, and COX-2 in the spinal cord ventral horn were performed at week 1 post-burn. In addition, we examined autophagy changes by biomarkers of LC3B and ATG5. The expression of BCL-2, BAX, cleaved caspase-3, phospho-AKT, and mTOR was assessed simultaneously through Western blotting. EPO administration after burn injury attenuated neuroinflammation through various mechanisms, including the reduction of microglia activity as well as iNOS and COX-2 expression in the spinal cord ventral horn. In addition, the expression of phospho-AKT, mTOR and apoptotic indicators, such as BAX, BCL-2, and cleaved caspase-3, was modulated. Furthermore, the activity of burn-induced autophagy in the spinal cord ventral horn characterized by the expression of autophagic biomarkers, LC3B and ATG5, was reduced after EPO administration. The present results indicate that EPO inhibits the AKT-mTOR pathway to attenuate burn-induced motor neuron programmed cell death and microglia activation. EPO can modulate neuroinflammation and programmed cell death and may be a therapeutic candidate for neuroprotection.

Recombinant human erythropoietin for treating severe traumatic brain injury

BACKGROUND

This study aimed to explore the efficacy and safety of recombinant human erythropoietin (RHE) for the treatment of severe traumatic brain injury (STBI).

METHODS

One hundred and twenty eligible patients with STBI were randomly divided into an intervention group or a control group equally. Patients in the intervention group received RHE. The participants in the control group received 0.9% saline. The outcome measurements included the Glasgow Outcome Scale (GOS) scores, mortality, and any adverse events.

RESULTS

At the end of 10-week follow-up after treatment, RHE neither showed greater efficacy in GOS scores (1-2, P = .43; 3-4, P = .25; 5-6, P = .58; 7-8, P = .23), nor the lower mortality in the intervention group than those in the control group (P = .47). In addition, both groups had similar safety profile.

CONCLUSION

This study found that RHE did not improve the neurological outcomes in patients with STBI.

Harms of off-label erythropoiesis-stimulating agents for critically ill people

BACKGROUND

Anaemia is a common problem experienced by critically-ill people. Treatment with erythropoiesis-stimulating agents (ESAs) has been used as a pharmacologic strategy when the blunted response of endogenous erythropoietin has been reported in critically-ill people. The use of ESAs becomes more important where adverse clinical outcomes of transfusing blood products is a limitation. However, this indication for ESAs is not licensed by regulatory authorities and is called off-label use. Recent studies concern the harm of ESAs in a critical care setting.

OBJECTIVES

To focus on harms in assessing the effects of erythropoiesis-stimulating agents (ESAs), alone or in combination, compared with placebo, no treatment or a different active treatment regimen when administered off-label to critically-ill people.

SEARCH METHODS

We conducted a systematic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO via OvidSP, CINAHL, all evidence-based medicine (EBM) reviews including IPA and SCI-Expanded, Conference Proceedings Citation Index- Science, BIOSIS Previews and TOXLINE up to February 2017. We also searched trials registries, checked reference lists of relevant studies and tracked their citations by using SciVerse Scopus.

SELECTION CRITERIA

We considered randomized controlled trials (RCTs) and controlled observational studies, which compared scheduled systemic administration of ESAs versus other effective interventions, placebo or no treatment in critically-ill people.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened and evaluated the eligibility of retrieved records, extracted data and assessed the risks of bias and quality of the included studies. We resolved differences in opinion by consensus or by involving a third review author. We assessed the evidence using GRADE and created a 'Summary of findings' table. We used fixed-effect or random-effects models, depending on the heterogeneity between studies. We fitted three-level hierarchical Bayesian models to calculate overall treatment effect estimates.

MAIN RESULTS

Of the 27,865 records identified, 39 clinical trials and 14 observational studies, including a total of 945,240 participants, were eligible for inclusion. Five studies are awaiting classification. Overall, we found 114 adverse events in 33 studies (30 RCTs and three observational studies), and mortality was reported in 41 studies (32 RCTs and nine observational studies). Most studies were at low to moderate risk of bias for harms outcomes. However, overall harm assessment and reporting were of moderate to low quality in the RCTs, and of low quality in the observational studies. We downgraded the GRADE quality of evidence for venous thromboembolism and mortality to very low and low, respectively, because of risk of bias, high inconsistency, imprecision and limitations of study design.It is unclear whether there is an increase in the risk of any adverse events (Bayesian risk ratio (RR) 1.05, 95% confidence interval (CI) 0.93 to 1.21; 3099 participants; 9 studies; low-quality evidence) or venous thromboembolism (Bayesian RR 1.04, 95% CI 0.70 to 1.41; 18,917 participants; 18 studies; very low-quality evidence).There was a decreased risk of mortality with off-label use of ESAs in critically-ill people (Bayesian RR 0.76, 95% CI 0.61 to 0.92; 930,470 participants; 34 studies; low-quality evidence).

AUTHORS' CONCLUSIONS

Low quality of evidence suggests that off-label use of ESAs may reduce mortality in a critical care setting. There was a lack of high-quality evidence about the harm of ESAs in critically-ill people. The information for biosimilar ESAs is less conclusive. Most studies neither evaluated ESAs' harm as a primary outcome nor predefined adverse events. Any further studies of ESA should address the quality of evaluating, recording and reporting of adverse events.

Serial Sampling of Serum Protein Biomarkers for Monitoring Human Traumatic Brain Injury Dynamics: A Systematic Review

BACKGROUND

The proteins S100B, neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), and neurofilament light (NF-L) have been serially sampled in serum of patients suffering from traumatic brain injury (TBI) in order to assess injury severity and tissue fate. We review the current literature of serum level dynamics of these proteins following TBI and used the term "effective half-life" (t1/2) in order to describe the "fall" rate in serum.

MATERIALS AND METHODS

Through searches on EMBASE, Medline, and Scopus, we looked for articles where these proteins had been serially sampled in serum in human TBI. We excluded animal studies, studies with only one presented sample and studies without neuroradiological examinations.

RESULTS

Following screening (10,389 papers), n = 122 papers were included. The proteins S100B (n = 66) and NSE (n = 27) were the two most frequent biomarkers that were serially sampled. For S100B in severe TBI, a majority of studies indicate a t1/2 of about 24 h, even if very early sampling in these patients reveals rapid decreases (1-2 h) though possibly of non-cerebral origin. In contrast, the t1/2 for NSE is comparably longer, ranging from 48 to 72 h in severe TBI cases. The protein GFAP (n = 18) appears to have t1/2 of about 24-48 h in severe TBI. The protein UCH-L1 (n = 9) presents a t1/2 around 7 h in mild TBI and about 10 h in severe. Frequent sampling of these proteins revealed different trajectories with persisting high serum levels, or secondary peaks, in patients with unfavorable outcome or in patients developing secondary detrimental events. Finally, NF-L (n = 2) only increased in the few studies available, suggesting a serum availability of >10 days. To date, automated assays are available for S100B and NSE making them faster and more practical to use.

CONCLUSION

Serial sampling of brain-specific proteins in serum reveals different temporal trajectories that should be acknowledged. Proteins with shorter serum availability, like S100B, may be superior to proteins such as NF-L in detection of secondary harmful events when monitoring patients with TBI.

Recovery from experimental parkinsonism by intrastriatal application of erythropoietin or EPO-releasing neural precursors

An extensive literature has shown a powerful neuroprotective action of Erythropoietin (EPO) both in vivo and in vitro. This study shows that EPO, whether ectopically administered or released by neural precursors, does reverse MPTP-induced parkinsonism in mice. Unilateral stereotaxic injection of 2.5 × 10⁵ erythropoietin-releasing neural precursor cells (Er-NPCs) rescued degenerating striatal dopaminergic neurons and promoted behavioral recovery as shown by three independent behavioral tests. These effects were replicated through direct intrastriatal administration of recombinant human EPO. At the end of the observational period, most of the transplanted Er-NPCs were vital and migrated via the striatum to reach Substantia Nigra. The restorative effects appear to be mediated by EPO since co-injection of anti-EPO or anti-EPOR antibodies antagonized the positive outcomes. Furthermore, this report supports the neuroprotective action of EPO, which may also be achieved via administration of EPO-releasing cells such as Er-NPCs.

A review of the clinical utility of serum S100B protein levels in the assessment of traumatic brain injury

Background

In order to improve injury assessment of brain injuries, protein markers of pathophysiological processes and tissue fate have been introduced in the clinic. The most studied protein “biomarker” of cerebral damage in traumatic brain injury (TBI) is the protein S100B. The aim of this narrative review is to thoroughly analyze the properties and capabilities of this biomarker with focus on clinical utility in the assessment of patients suffering from TBI.

Results

S100B has successfully been implemented in the clinic regionally (1) to screen mild TBI patients evaluating the need to perform a head computerized tomography, (2) to predict outcome in moderate-to-severe TBI patients, (3) to detect secondary injury development in brain-injured patients and (4) to evaluate treatment efficacy. The potential opportunities and pitfalls of S100B in the different areas usually refer to its specificity and sensitivity to detect and assess intracranial injury.

Conclusion

Given some shortcomings that should be realized, S100B can be used as a versatile screening, monitoring and prediction tool in the management of TBI patients.

A review of the clinical utility of serum S100B protein levels in the assessment of traumatic brain injury

BACKGROUND

In order to improve injury assessment of brain injuries, protein markers of pathophysiological processes and tissue fate have been introduced in the clinic. The most studied protein "biomarker" of cerebral damage in traumatic brain injury (TBI) is the protein S100B. The aim of this narrative review is to thoroughly analyze the properties and capabilities of this biomarker with focus on clinical utility in the assessment of patients suffering from TBI.

RESULTS

S100B has successfully been implemented in the clinic regionally (1) to screen mild TBI patients evaluating the need to perform a head computerized tomography, (2) to predict outcome in moderate-to-severe TBI patients, (3) to detect secondary injury development in brain-injured patients and (4) to evaluate treatment efficacy. The potential opportunities and pitfalls of S100B in the different areas usually refer to its specificity and sensitivity to detect and assess intracranial injury.

CONCLUSION

Given some shortcomings that should be realized, S100B can be used as a versatile screening, monitoring and prediction tool in the management of TBI patients.